Home About us Contact
|
Home About us Contact | ||
|
|
||
Para
Kinds of Para Terms modified by Para Selected AbstractsA solid-state NMR study of phase structure, molecular interactions, and mobility in blends of citric acid and paracetamolJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2009S. Schantz Abstract Citric acid anhydrate (CAA) and paracetamol (PARA), prepared as crystalline physical mixtures and as amorphous blends, were studied using 13C solid-state cross polarization magic angle spinning (CPMAS) NMR. Amorphous blends showed significant line broadening from the conformational distribution as compared to the crystalline samples. Also, chemical shift variations were observed between crystalline and amorphous blends, which were attributed to differences in intermolecular interactions. Averaging of proton rotating-frame spin-lattice relaxation times (T1,) probed via different 13C sites in the amorphous blends confirmed molecular level mixing. For some, initially amorphous, sample compositions the onset of crystallization was evident directly from spectra and from the significantly longer T1, relaxations. Thus, crystallization caused phase separation with properties of the two phases resembling those of pure CAA and PARA, respectively. 13C spectra of amorphous 50/50 (w/w, %) CAA/PARA recorded from above the glass transition temperature broadened as the temperature increased to a maximum at T,,,Tg,+,33 K. This was the result of a dynamic interference between the line narrowing techniques being applied and the time scale of molecular reorientation in the miscible melt. The derived average correlation time was found to correspond well with previous results from melt rheology. We conclude that the underlying reasons for physical instability (i.e., crystallization from the miscible melt, including molecular interactions and dynamics) of this class of amorphous binary mixtures can be effectively evaluated using NMR spectroscopy. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1862,1870, 2009 [source] Use of Nursing Diagnoses and Interventions in Public Health Nursing PracticeINTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 1 2002Jennifer C. Rivera MSN PURPOSE. To determine the frequency of use of NANDA diagnoses and the Nursing Interventions Classification in care plans written by public health nurses (PHNs) in Orange County, CA. METHODS.Retrospective chart review. FINDINGS. The frequency pattern of nursing diagnoses and nursing interventions used in care plans is consistent with the scope of practice of the PHN, whose emphasis is on health promotion and disease prevention. CONCLUSIONS. The most commonly used diagnoses and interventions provide evidence of a core set of interventions useful for PHN practice. IMPLICATIONS FOR PRACTICE.Linking diagnoses and interventions allow PHNs to build a body of knowledge based on patient care and improve clinical decision-making process. Search terms:Interventions, nursing diagnosis, public health nursing Utilisation des diagnostics infirmiers et interventions en santé publique BUT.Déterminer la fréquence des diagnostics infirmiers (ANADI) et des interventions (NIC) dans les plans de soins rédigés par les infirmières de santé publique dans le Comté d'Orange, CA. METHODE.Étude rétrospective des dossiers. RÉSULTATS.La répartition des diagnostics infirmiers et des interventions utilisés dans les plans de soin est cohérente avec la pratique des infirmières en santé publique, c'est-à-dire qu'elle souligne l'importance de la promotion de la santé et la prévention de la maladie. CONCLUSIONS.Les diagnostics et interventions les plus fréquemment utilisés permettent d'identifier le groupe d'interventions au centre de la pratique des soins en santé publique. IMPLICATIONS POUR LA PRATIQUE.L'articulation des diagnostics et interventions de soins permet de construire un corpus de connaissances en santé publique basée sur le soin des patients et d'améliorer le processus de décision clinique. Mots-clés:Diagnostics infirmiers, interventions, soins infirmiers en santé publique Utilización de los diagnósticos e intervenciones de enfermería en la práctica de enfermería de salud pública PROPÓSITO.Determinar la frecuencia del uso de los diagnósticos de la NANDA y de la clasificación de las intervenciones enfermeras (NIC), en planes del cuidados escritos por enfermeras de salud pública en el Condado de Orange, California. MÉTODOS.Revisión retrospectiva de gráficos. RESULTADOS. El patrón de frecuencia de diagnósticos de enfermería y de intervenciones enfermeras utilizados en los planes del cuidados, es consistente con el ámbito asistencial de las enfermeras de salud pública, cuyo énfasis está en la promoción de salud y la prevención de la enfermedad. CONCLUSIÓN.Los diagnósticos e intervenciones más comúnmente utilizados, proporcionan evidencia de un grupo nuclear de intervenciones útiles a la práctica de enfermería de salud pública. IMPLICACIONES PARA LA PRÁCTICA.Conectar los diagnósticos y las intervenciones permite a las Enfermeras de Salud Pública construir un cuerpo de conocimientos basado en el cuidado de los pacientes y mejorar el proceso de toma de decisiones en la práctica clínica. Términos de búsqueda:Diagnóstico enfermero, enfermería de salud pública, intervenciones Uso de diagnósticos e intervenções de enfermagem na prótica de enfermagem em Saúde Pública OBJETIVO.Determinar a freqüência de uso dos diagnósticos da NANDA e da Classificação de Intervenções de Enfermagem (NIC) em planos de cuidados escritos por enfermeiras da área de Saúde Pública no Condado de Orange, Califórnia. MÉTODO.Revisão retrospectiva de fichas. ACHADOS.O padrão de freqüência de diagnósticos de enfermagem e intervenções de enfermagem utilizados em planos de cuidados é compatível com o escopo da prática das enfermeiras da área de Saúde Pública, cuja ênfase está na promoção da saúde e prevenção de doenças. CONCLUSãO.Os diagnósticos e intervenções mais comumente utilizados evidenciam a existência de um conjunto de intervenções principais, que éútil para a prática destas enfermeiras. IMPLICAÇõES PARA A PRÁTICA. A ligação entre diagnósticos e intervenções permite às enfermeiras da área de saúde pública construírem um corpo de conhecimentos baseado no cuidado do paciente e melhora o processo de tomada de decisão. Palavras para busca:Diagnóstico de enfermagem, enfermagem em saúde publica, intervenções [source] A solid-state NMR study of phase structure, molecular interactions, and mobility in blends of citric acid and paracetamolJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2009S. Schantz Abstract Citric acid anhydrate (CAA) and paracetamol (PARA), prepared as crystalline physical mixtures and as amorphous blends, were studied using 13C solid-state cross polarization magic angle spinning (CPMAS) NMR. Amorphous blends showed significant line broadening from the conformational distribution as compared to the crystalline samples. Also, chemical shift variations were observed between crystalline and amorphous blends, which were attributed to differences in intermolecular interactions. Averaging of proton rotating-frame spin-lattice relaxation times (T1,) probed via different 13C sites in the amorphous blends confirmed molecular level mixing. For some, initially amorphous, sample compositions the onset of crystallization was evident directly from spectra and from the significantly longer T1, relaxations. Thus, crystallization caused phase separation with properties of the two phases resembling those of pure CAA and PARA, respectively. 13C spectra of amorphous 50/50 (w/w, %) CAA/PARA recorded from above the glass transition temperature broadened as the temperature increased to a maximum at T,,,Tg,+,33 K. This was the result of a dynamic interference between the line narrowing techniques being applied and the time scale of molecular reorientation in the miscible melt. The derived average correlation time was found to correspond well with previous results from melt rheology. We conclude that the underlying reasons for physical instability (i.e., crystallization from the miscible melt, including molecular interactions and dynamics) of this class of amorphous binary mixtures can be effectively evaluated using NMR spectroscopy. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1862,1870, 2009 [source] Effect of Diet Processing Method and Ingredient Substitution on Feed Characteristics and Survival of Larval Walleye, Sander vitreusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2006Frederic T. Barrows Two methods were developed for the production of larval fish diets. The first method, microextrusion marumerization (MEM), has been tested in laboratory feeding trials for many years and produces particles that are palatable and water stable. The second method, particle-assisted rotational agglomeration (PARA), produced diets that have lower density than diets produced by MEM. Each method was used to produce diets in the 250- to 400- and 400- to 700-,m range and compared with a reference diet (Fry Feed Kyowa, [FFK]) for feeding larval walleye in two experiments. The effect of substituting 4% of the fish meal with freeze-dried artemia fines was also investigated. In the first experiment, 30-d survival was greater (P < 0.05) for fish fed a diet produced by PARA without Artemia (49.1.0%) than for fish fed the same diet produced by MEM (27.6%). The addition of Artemia to a diet produced by MEM did not increase survival of larval walleye. Fish fed the reference diet had 24.4% survival. In the second experiment, there was an effect of both processing method and Artemia supplementation, and an interaction of these effects, on survival. Fish fed a diet produced by PARA without Artemia supplementation had 48.4% survival, and fish fed the same diet produced by MEM had only 19.6% survival. Inclusion of 4% freeze-dried Artemia improved (P < 0.04) survival of fish fed MEM particles but not those fed PARA particles. Fish fed FFK had greater weight gain than fish fed other diets in both experiments. Data indicate that the PARA method of diet processing produces smaller, lower density particles than the MEM process and that diets produced by the PARA process support higher survival of larval walleye with low capital and operating costs. [source] Neuronal loss and neurofibrillary degeneration in the hippocampal cortex in late-onset sporadic Alzheimer's diseasePSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2000Yuken Fukutani MD Abstract To explore more fully the relationship between neuronal death and neurofibrillary degeneration, unaffected neurons, intracellular neurofibrillary tangles (i-NFT) and extracellular NFT (e-NFT) in 22 patients with late-onset sporadic Alzheimer's disease (AD) were morphometrically evaluated in eight subdivisions of the hippocampal cortex, using the Gallyas hematoxylin-eosin stain. The subdivisions examined included CA4, CA3, CA2, CA1 (CA: cornu ammonis), prosubiculum (PRO), subiculum and presubiculum (PRE), parasubiculum (PARA) and the entorhinal cortex (ENT). The unaffected neuron density was significantly lower and both i-NFT and e-NFT densities were significantly higher in subdivisions other than CA4 and CA3 in AD patients compared with those in the aged controls. Unaffected neuron density was significantly, inversely correlated with e-NFT density and with total NFT density in all subdivisions except for PRE in AD patients. Especially in CA2, CA1, PRO and ENT, there were strong correlations between the neuron density and these NFT densities. Both unaffected neuron and e-NFT densities in CA1 and ENT were significantly correlated with the disease duration. The i/e-NFT ratio, an index of the degree and/or rate of progress of neuronal death via neurofibrillary degeneration, showed the lowest value in ENT in AD patients. The findings suggest that neuronal death via neurofibrillary degeneration starts earliest and/or most rapidly progresses in ENT. Furthermore, the i/e-NFT ratios in both ENT and CA1 were significantly correlated with the disease duration, suggesting that the neuronal death pattern in the two subdivisions parallels disease progression. [source] F plasmid partition depends on interaction of SopA with non-specific DNAMOLECULAR MICROBIOLOGY, Issue 4 2008Jean-Philippe Castaing Summary Bacterial ATPases belonging to the ParA family assure partition of their replicons by forming dynamic assemblies which move replicon copies into the new cell-halves. The mechanism underlying partition is not understood for the Walker-box ATPase class, which includes most plasmid and all chromosomal ParAs. The ATPases studied both polymerize and interact with non-specific DNA in an ATP-dependent manner. Previous work showed that in vitro, polymerization of one such ATPase, SopA of plasmid F, is inhibited by DNA, suggesting that interaction of SopA with the host nucleoid could regulate partition. In an attempt to identify amino acids in SopA that are needed for interaction with non-specific DNA, we have found that mutation of codon 340 (lysine to alanine) reduces ATP-dependent DNA binding > 100-fold and correspondingly diminishes SopA activities that depend on it: inhibition of polymer formation and persistence, stimulation of basal-level ATP hydrolysis and localization over the nucleoid. The K340A mutant retained all other SopA properties tested except plasmid stabilization; substitution of the mutant SopA for wild-type nearly abolished mini-F partition. The behaviour of this mutant indicates a causal link between interaction with the cell's non-specific DNA and promotion of the dynamic behaviour that ensures F plasmid partition. [source] Understanding the Causes of Disease in European Freshwater CrayfishCONSERVATION BIOLOGY, Issue 6 2004BRETT F. EDGERTON Aphanomyces astaci; bioseguridad; epizootia; langostinos de agua dulce; patología de langostinos; peste de langostinos Abstract:,Native European freshwater crayfish (Astacida, Decapoda) are under severe pressure from habitat alteration, the introduction of nonindigenous species, and epizootic disease. Crayfish plague, an acute disease of freshwater crayfish caused by the fungus-like agent Aphanomyces astaci, was introduced into Europe in the mid-nineteenth century and is responsible for ongoing widespread epizootic mortality in native European populations. We reviewed recent developments and current practices in the field of crayfish pathology. The severity of crayfish plague has resulted in an overemphasis on it. Diagnostic methods for detecting fungi and fungal-like agents, and sometimes culturing them, are frequently the sole techniques used to investigate disease outbreaks in European freshwater crayfish. Consequently, the causes of a significant proportion of outbreaks are undetermined. Pathogen groups well known for causing disease in other crustaceans, such as viruses and rickettsia-like organisms, are poorly understood or unknown in European freshwater crayfish. Moreover, the pathogenic significance of some long-known pathogens of European freshwater crayfish remains obscure. For effective management of this culturally significant and threatened resource, there is an urgent need for researchers, diagnosticians, and resource managers to address the issue of disease in European freshwater crayfish from a broader perspective than has been applied previously. Resumen:,Los langostinos nativos de Europa (Astacida, Decapada) están bajo severa presión por alteración del hábitat, la introducción de especies no nativas y una enfermedad epizoótica. La peste de langostinos, una enfermedad aguda de langostinos de agua dulce producida por el agente micoide Aphanomyces astaci, fue introducida a Europa a mediados del siglo diecinueve y es responsable de la actual mortalidad epizoótica de poblaciones Europeas nativas. Revisamos acontecimientos recientes y prácticas actuales en el campo de la patología de langostinos. La severidad de la peste de langostinos ha resultado en un excesivo énfasis en ella. Los métodos para diagnosticar, y algunas veces cultivar, hongos y agentes micoides frecuentemente son la única técnica empleada al investigar brotes de la enfermedad en langostinos de agua dulce en Europa. Consecuentemente, no están determinadas las causas de una proporción significativa de los brotes. Grupos patógenos, como virus y organismos similares a rickettsias, bien conocidos por producir enfermedades en otros crustáceos son poco o nada conocidos en langostinos de agua dulce de Europa. Más aún, el significado patogénico de algunos patógenos de langostinos de agua dulce de Europa largamente conocidos es oscuro. Para el manejo efectivo de este recurso culturalmente significativo y amenazado es urgente la necesidad de investigadores, diagnosticadores y gestores de recursos para atender el asunto de la enfermedad en langostinos de agua dulce europeos desde una perspectiva más amplia que la previamente aplicada. [source] Patch Occupancy and Potential Metapopulation Dynamics of Three Forest Mammals in Fragmented Afromontane Forest in South AfricaCONSERVATION BIOLOGY, Issue 4 2000Michael J. Lawes We recorded patch occupancy of blue duiker ( Philantomba monticola), tree hyrax ( Dendrohyrax arboreus), and samango monkey (Cercopithecus mitis labiatus) in 199 forest patches. Their rarity is ascribed to the fragmentation and destruction of their forest habitat. Incidence functions, derived from presence and absence data, were formulated as generalized linear models, and environmental effects were included in the fitted logistic models. The small and mostly solitary hyrax and duiker persisted in smaller patches than the large and social monkey. Although this result follows expectations based on relative home-range sizes of each species, the incidence probability of the samango monkey was invariant with increasing isolation, whereas a gradual decrease with increasing isolation was observed for the hyrax and duiker. Group dynamics may inhibit dispersal and increase the isolation effect in social species such as samango monkeys. A mainland-island metapopulation model adequately describes patterns of patch occupancy by the hyrax and duiker, but the monkeys' poor dispersal ability and obvious area-dependent extirpation suggest that they exist in transient, nonequilibrium (declining) metapopulations. Through identification of large forest patches for careful protection and management, the survival of all three species,especially the monkey,could be prolonged. Because no functional metapopulation may exist for the monkey, however, this is an emergency measure. For the duiker and hyrax, larger patches should form part of a network of smaller and closer patches in a natural matrix. Resumen: Investigamos la persistencia de tres mamíferos forestales raros de tamaño mediano (2,9 kg) en los bosques fragmentados de cinturón de niebla Podocarpus en la región central de la provincia KwaZulu-Natal, Sudáfrica. Registramos la ocupación del duiker azul ( Philantomba monticola), el hyrax arborícola ( Dendrohyrax arboreus) y el mono samango (Cercopithecus mitis labiatus) en 199 parches forestales. Su rareza se atribuye a la fragmentación y destrucción de su hábitat forestal. Las funciones de incidencia, derivadas de datos de presencia y ausencia, fueron formuladas como modelos lineales generalizados, y los efectos ambientales fueron incluidos en los modelos logísticos ajustados. Los pequeños y mayormente solitarios hyrax y duiker persistieron en parches más pequeños que los monos, que son más grandes y más sociables. A pesar de que este resultado obedece a expectativas basadas en tamaños de rango de hogar relativos de cada especie, la probabilidad de incidencia del mono samango no cambió con un incremento en el aislamiento, mientras que una disminución gradual al crecer el aislamiento se observó en hyrax y duiker. Las dinámicas de grupos podrían inhibir la dispersión e incrementar el efecto de aislamiento en especies sociables como lo es el mono samango. Un modelo de metapoblación continente-isla describe adecuadamente los patrones de la ocupación de parches por hyrax y duiker; sin embargo, la pobre capacidad de dispersión de los monos y la obvia extirpación área-dependente sugiere que estos existen en metapoblaciones transitorias, desequilibradas (en disminución). Mediante la identificación de parches forestales grandes para la protección y manejo cuidadosos, la supervivencia de las tres especies ( pero especialmente la de los monos) podría ser prolongada. Sin embargo, debido a que no existen metapoblaciones funcionales de monos, esta es una medida de emergencia. Para el duiker y el hyrax, los parches grandes deberán formar parte de una red de parches más pequeños y más cercanos en una matriz natural. [source] "I Was There:" Competing Indigenous Imaginaries of the Past and the Future in Oaxaca's Sierra MazatecaJOURNAL OF LATIN AMERICAN & CARIBBEAN ANTHROPOLOGY, Issue 1 2006Ben FeinbergArticle first published online: 28 JUN 200 En este artículo, examino las diferentes formas por las cuales dos individuos Mazatecos representan la cultura, la autenticidad, y una conceptualización Mazateca de la historia durante sus interacciones con gente no Mazateca.Ambos adaptan estilos metaculturales diferentes para crear naraciones de autenticidad. Para el primero, la autenticidad es una cualidad compartida por individuos que sirven de mediadores entre grupos culturales diferentes y que se extiende a sus representaciones culturales; para el segundo, la autenticidad nace en la cultura reificada que sobrevive del pasado. Estos discursos diferentes se manifiestan en discusiones sobre los años sesenta en la Sierra mazateca,una época cuando miles de estrangeros asociados con la contracultura de esta década visitaron la región para experimentar con los hongos alucinogénicos. PALABRAS CLAVES: Oaxaca, Mazateca, identidad indígena, chamanismo, metacultura, turismo. KEYWORDS: Oaxaca, Mazateca, indigenous identity, shamanism, metaculture, tourism. [source] High diversity of HHV-8 molecular subtypes in the Amazon region of Brazil: Evidence of an ancient human infection,JOURNAL OF MEDICAL VIROLOGY, Issue 10 2007Marluísa de Oliveira Guimarães Ishak Abstract The present study describes the molecular epidemiology of Human herpesvirus 8 (HHV-8) among four Indian tribes (Kararao, Arara Laranjal, Tiriyo, and Zo'e) of the Amazon region of Brazil and a group of HIV-1-infected subjects from the urban population of Belem, Para. Infection was characterized by the presence of antibodies using ELISA (measuring antibodies to ORF59, ORF65, K8.1A, K8.1B, and ORF73), and molecular assays (gene amplification of the regions ORF26 and the variable region VR1). Antibodies to HHV-8 were detected in 66 samples of the 221 Brazilian Amerindians, namely, 6 (25%) in the Kararao, 18 (19.6%) in the Arara Laranjal, 24 (42.9%) in the Tiriyo, and 18 (36.7%) in the Zo'e. Among the 477 HIV-1-infected subjects, antibodies to HHV-8 were present in 74 (15.5%) persons. The ORF26 region was amplified in seven samples, one of the Arara Laranjal, one of the Tiriyo, two of the Zo'e, and three of the HIV-1-infected group. Subtyping of HHV-8 described a high multiplicity of molecular subtypes, including C (Zo'e), E (Tiriyo), and B (HIV-1 infected). Serological results confirm the high prevalence of HHV-8 among Amerindians and the presence of three subtypes in the Amazon region of Brazil, including a unique subtype, which favors the idea of HHV-8 as an ancient human infection within this particular geographical region. J. Med. Virol. 79:1537,1544, 2007. © Wiley-Liss, Inc. [source] The human brain endothelial cell line hCMEC/D3 as a human blood-brain barrier model for drug transport studiesJOURNAL OF NEUROCHEMISTRY, Issue 5 2008Birk Poller Abstract The human brain endothelial capillary cell line hCMEC/D3 has been developed recently as a model for the human blood-brain barrier. In this study a further characterization of this model was performed with special emphasis on permeability properties and active drug transport. Para- or transcellular permeabilities (Pe) of inulin (0.74 × 10,3 cm/min), sucrose (1.60 × 10,3 cm/min), lucifer yellow (1.33 × 10,3 cm/min), morphine (5.36 × 10,3 cm/min), propranolol (4.49 × 10,3 cm/min) and midazolam (5.13 × 10,3 cm/min) were measured. By addition of human serum the passive permeability of sucrose could be reduced significantly by up to 39%. Furthermore, the expression of a variety of drug transporters (ABCB1, ABCG2, ABCC1,5) as well as the human transferrin receptor was demonstrated on the mRNA level. ABCB1, ABCG2 and transferrin receptor proteins were detected and functional activity of ABCB1, ABCG2 and the ABCC family was quantified in efflux experiments. Furthermore, ABCB1-mediated bidirectional transport of rhodamine 123 was studied. The transport rate from the apical to the basolateral compartment was significantly lower than that in the inverse direction, indicating directed p-glycoprotein transport. The results of this study demonstrate the usefulness of the hCMEC/D3 cell line as an in vitro model to study drug transport at the level of the human blood-brain barrier. [source] Para -halogenated benzaldehyde molecules included in cyclodextrins: a combined spectroscopic and thermal analysisJOURNAL OF RAMAN SPECTROSCOPY, Issue 4 2006Paulo J. A. Ribeiro-Claro Abstract The inclusion complexes of 4-X-benzaldehyde guests (X = F, Cl, Br) in ,-, ,-and ,-cyclodextrins (,CD, ,CD and ,CD) were prepared and characterized by means of thermogravimetry, differential scanning calorimetry (DSC) and vibrational spectroscopy. The stoichiometry of the inclusion complexes ranges from 2:1 to 1:2, depending on the cavity size of the host. Sensitive vibrational modes such as CO and ring CH stretching modes were used to monitor the effects of the inclusion process and to assess the preferred inclusion geometry for each host-guest pair. On the whole, the spectral observations suggest that the small ,CD cavity imposes important structural restrictions on the guest molecule, while the larger ,CD cavity allows ,liquid-type' intermolecular contacts. Copyright © 2005 John Wiley & Sons, Ltd. [source] Association between TNFA-308 G/A polymorphism and sensitization to para- phenylenediamine: a case,control studyALLERGY, Issue 2 2009B. Blömeke Background:,Para -phenylenediamine (PPD) and related chemicals are common contact sensitizers, frequently causing allergic contact dermatitis (ACD). The cytokine tumor necrosis factor-alpha (TNF-,) plays a key role in contact sensitization. Methods:, In this case,control study, we evaluated the distribution of variations in the regulatory region of the gene for TNF-, (TNFA-308 G/A) in 181 Caucasian individuals with a history of ACD and sensitization to PPD and 161 individuals with no history of sensitization to PPD. Results:, The frequency of GA or AA TNFA genotypes was significantly higher in individuals sensitized to PPD than in age- and gender-matched controls giving an odds ratio (OR) of 2.16 (95% confidence interval, CI: 1.35,3.47; P = 0.0016). This relation was even more pronounced when restricting cases to females over 45 years (OR = 3.71; 95% CI: 1.65,8.31; P = 0.0017) vs younger females (less than or equal to 45 years; OR = 2.41; 95% CI: 1.03,5.65; P = 0.044) or males (OR = 1.05; 95% CI: 0.449,2.47; P = 1.0). In addition, a logistic regression model revealed a significant effect for TNFA-308 AA and AG vs GG genotype (point estimate = 2.152; 95% Wald CI: 1.332,3.477). Conclusions:, These findings suggest a possible role for the TNFA-308 genetic polymorphism as a susceptibility factor for chemically induced ACD. [source] The European Union Constitution on Border Checks, Asylum, and ImmigrationPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2004Article first published online: 15 DEC 200 The Treaty Establishing a Constitution for Europe was signed by the heads of government of the 25 European Union member states and three candidate states on 29 October 2004. The Treaty in effect is the proposed constitution, a long and elaborate document comprising 448 Articles (grouped into four Parts, with additional divisions into Titles, Chapters, and Sections, but numbered consecutively throughout) and 29 Protocols,annexes to the Treaty. Five articles and four protocols are concerned with issues of border control, immigration, and asylum policy. The articles are found in the chapter titled Area of Freedom, Security and Justice in Part III of the Treaty (The Policies and Functioning of the Union). These are reproduced below, along with one of the protocols (number 21). (Of the other protocols concerned with migration, one adds to the Treaty the provisions of the Schengen Acquis, the agreement among all EU members except the United Kingdom and Ireland, plus the non-EU states Norway and Iceland, to eliminate border controls at their common frontiers, and requires acceptance of the Acquis by any new member. Two other protocols set out reservations on the part of the UK and Ireland on border control and asylum matters,basically, an "opt-in" stance, allowing their participation in Treaty provisions on a case-by-case basis.) The constitution is highly detailed in scope but often vague in content, merely specifying topics on which policies will be developed or laws enacted. Thus the "common immigration policy" that is signaled in Article III-267 is yet to be shaped, and the Treaty offers few hints of what it may look like. A reluctance on the part of member states to cede sovereignty in the area of immigration is not limited to the British Isles. It is seen also in the retained right of all members to restrict non-EU labor migrants (Article III-267, Para. 5) and to conclude bilateral agreements on border crossing with non-EU states (Protocol 21). It is notable that the Treaty, while stressing that all nationals of member states are citizens of the Union with the right "to move and reside freely" within its territory, does not attempt to harmonize conditions or procedures under which migrants can acquire citizenship: indeed, it says nothing at all on the matter. (A "framework law," mentioned at various points in the text, is a law that prescribes the result to be achieved but leaves to each member state "the choice of form and methods.") Actual adoption of the constitution requires ratification by the governments of all EU members. If this demanding hurdle is passed (requiring parliamentary approval or, in some cases, a referendum), the constitution would come into force on 1 November 2006,or after the final ratification, if later. Under Article IV-443, if the treaty is ratified by four-fifths of members within the two years but is rejected by one or more states, "the matter shall be referred to the European Council",the quarterly summit meeting of heads of government. [source] Expression, purification, crystallization and preliminary X-ray analysis of para -nitrophenol 4-monooxygenase from Pseudomonas putida DLL-E4ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2009Weidong Liu Para -nitrophenol 4-monooxygenase (PnpA) plays an important role in bacterial degradation of para -nitrophenol by oxidative release of the nitro group from the aromatic ring to form p -benzoquinone. In order to understand the structural basis of the function of this enzyme, PnpA was cloned, expressed in Escherichia coli and purified. PnpA was crystallized by the hanging-drop vapour-diffusion technique with PEG 4000 as precipitant. The PnpA crystals belonged to space group P212121, with unit-cell parameters a = 54.47, b = 77.56, c = 209.17,Å, and diffracted to 2.24,Å resolution. [source] Labile Phosphorus in Soils of Forest Fallows and Primary Forest in the Bragantina Region, BrazilBIOTROPICA, Issue 1 2003Jacqueline Frizano ABSTRACT We used the Hedley sequential extraction procedure to measure nine different organic inorganic soil phosphorus fractions in forest soil of the Bragantina region of Para, Brazil. We compared the labile fractions (resin-extractable P + HCO3-extractable inorganic and organic P) in Oxisols from three secondary forests (10, 20, and 40 years old) and a primary forest. These stands were located in an area that has supported shifting agriculture for approximately a century. After agricultural use, total P and labile P in soils of young secondary forests are diminished compared to the amounts presents in the primary forest soil. Within each stand, organic carbon content was a good predictor of labile organic and inorganic P, consistent with the large body of research indicating that mineralization of organic matter is important to plant nutrition in tropical ecosystems. During the reorganization of P pools during forest development, the pool of labile organic P (HCO3-extractable) diminishes more than the other labile fractions, suggesting that it is directly or indirectly an important source of P for the regrowing forest vegetation. Across the four age classes of forest, the soil reservoir of labile P was equal to or greater than the total amount of P in the vegetation. If labile P measured by this method adequately represents P available to plants in the short term (as suggested by the current consensus), we would conclude that plant-available P is reasonable abundant, and that the effects of agriculture on available P pools are detectable but not sufficient to compromise forest regrowth in this area. [source] Fluctuaciones Temporales en la Composición Floristica del Bosque Tropical Atlántico,BIOTROPICA, Issue 1 2001Samir Gonçalves Rolim ABSTRACT Temporal and spatial changes in floristic composition over a 15-year period in an Atlantic tropical forest in Brazil were analyzed. The data were recorded in five 0.5-ha (50 × 100 m) plots within a 22,000-ha forest reserve. In each plot, all stems ± 10 cm diameter at breast height (DBH) were repeatedly inventoried. The overall number of species among all plots was steady over time but changed within a given plot. In all plots, the proportion for the disappearance of species was 7 percent and that for immigration of new species into the plots was 9.5 percent. Approximately 65 percent of the disappearance occurred between 1986 and 1989, and 74 percent of the immigration happened after 1986. The observed changes in composition evidently were due to natural disturbance and climatic events, such as an unusual four-month drought. Disappearance of species from the plots did not denote regional extinction of those species, because they persisted elsewhere in the forest reserve. The changes in species composition within the plots and persistence outside them, however, indicated that large areas are required for in situ conservation of tropical tree species. These areas must be large enough for population changes to occur without negative effects on genetic and demographic structures of tree species. RESUMES Foram analisadas as variações temporais e espaciais na composição florística de uma floresta tropical num período de 15 anos entre os anos de 1980 e 1995. Em 5 parcelas de 0.5 ha (50 × 100 m) amostraram-se todas as árvores com diàmetro a altura do peito (DAP) , 10 cm. Para a escala e período que este estudo abrangeu pode-se concluir que há uma estabilidade no número de espécies da comunidade ao longo do tempo e esta estabilidade foi significativamente afetada por um distúrbio natural (um período seco de 4 meses) ocorrido em 1987. Foi constatado que em 15 anos desapareceram 7 por ciento das espécies nas parcelas monitoradas, contra um total de 9.5 por ciento de novas espécies recrutadas. Aproximadamente 65 por ciento do desaparecimento de espécies ocorreu entre 1986 e 1989 e 74 por ciento das novas espécies foram recrutadas apos 1986. O desaparecimento não significa necessariatmente um fenômeno de extinção e foi demonstrado que as espécies continuam ocorrendo na comunidade. O desaparecimento de espécies dentro das parcelas e sua pcrsisténcia fora delas indica que são necessárias grandes áreas para conservação in situ de espécies arbóreas. Estas áreas devem ser capazes de absorver as flutuaçz,oes populacionais sem afetar a estrutura genética e demográfica das espécies. [source] Metallocyclo- and Polyphosphazenes Containing Gold or Silver: Thermolytic Transformation into Nanostructured MaterialsCHEMISTRY - A EUROPEAN JOURNAL, Issue 48 2009Josefina Jiménez Dr. Abstract A cyclotriphosphazene bearing two 4-oxypyridine groups on the same phosphorus atom, gem -[N3P3(O2C12H8)2(OC5H4N-4)2] (I), and its analogous polymer [{NP(O2C12H8)}0.7{NP(OC5H4N-4)2}0.3]n (II), have been used to prepare gold or silver, cyclic and polymeric, metallophosphazenes. The following complexes, gem -[N3P3(O2C12H8)2(OC5H4N-4{ML})2] (ML=Au(C6F5) (1) or Au(C6F5)3 (2)), [N3P3(O2C12H8)2(OC5H4N-4{AuPPh3})2][NO3]2 (3), and [N3P3(O2C12H8)2(OC5H4N-4{AgPPh2R})2][SO3CF3]2 (R=Ph (4) or Me (5)) have been obtained. Complexes 1 and 4 are excellent models for the preparation of the analogous polymers [{NP(O2C12H8)}0.7{NP(OC5H4N-4{ML})2}0.3]n (ML=Au(C6F5) (P1), Ag(OSO2CF3)PPh3 (P2)). All complexes have been characterized by elemental analysis, various spectroscopic methods, and mass spectrometry. The polymers were further investigated by thermochemical methods (thermogravimetric analysis) and differential scanning calorimetry. For compounds 1,5 and for the starting phosphazene I, a mixture of different stereoisomers may be expected. The stereochemistry in solution has been studied by variable-temperature NMR spectroscopy studies, which provided evidence for interconversion processes that involve changes in the chirality of a 2,2,-dioxybiphenyl group. A single-crystal X-ray analysis of the gold complex 2 confirmed not only the proposed structure, but also S,S and R,R configurations at the two biphenoxy-substituted phosphorus centers, in contrast to those observed for the precursor I. Pyrolysis of these new metallophosphazenes was also studied. Notably, pyrolysis of the gold derivatives gave macroporous metallic gold sponges without the requirement of either an external reducing agent or a porous support. These materials were all characterized by XRD, TEM, SEM, and energy-dispersive X-ray spectroscopy. En este trabajo se ha usado el ciclotrifosfazeno que tiene dos grupos 4-oxipiridina en el mismo átomo de fósforo, gem -[N3P3(O2C12H8)2(OC5H4N-4)2] (I), y su polímero análogo, [{NP(O2C12H8)}0.7{NP(OC5H4N-4)2}0.3]n(II), para preparar nuevos compuestos de oro o plata, cíclicos o polímeros. Se han obtenido los siguientes complejos, gem -[N3P3(O2C12H8)2(OC5H4N-4{ML})2] [ML=Au(C6F5) (1), Au(C6F5)3 (2)], [N3P3(O2C12H8)2(OC5H4N-4{AuPPh3})2][NO3]2 (3) and [N3P3(O2C12H8)2(OC5H4N-4{AgPPh2R})2][SO3CF3]2 [R=Ph (4) or Me (5)], que a su vez han resultado ser excelentes modelos para preparar los polímeros análogos de oro o plata, [{NP(O2C12H8)}0.7{NP(OC5H4N-4{ML})2}0.3]n[ML=Au(C6F5)(P1), Ag(OSO2CF3)PPh3 (P2)]. Todos los complejos, cíclicos o polímeros, se han caracterizado por análisis elemental, por métodos espectroscópicos y por espectrometría de masas. Los polímeros, además, se han caracterizado por métodos termoquímicos (TGA y DSC). Para 1,5 y para el fosfazeno de partida (I) puede esperarse una mezcla de varios estereoisómeros. Se ha estudiado su estereoquímica en disolución por RMN a temperatura variable, lo que ha indicado la presencia de un proceso de interconversión que implica cambios de quiralidad del grupo 2,2,-dioxibifenilo. La resolución de la estructura cristalina del complejo 2, por difracción de Rayos X, no sólo ha confirmado la estructura propuesta sino que, además, indica una configuración (S,S)- y (R,R)- , a diferencia de lo observado para el precursor I. Se ha estudiado también la pirólisis de estos nuevos metalofosfazenos. Cabe destacar que la pirólisis de los derivados de oro, trímero (1) y polímero (P1), dio esponjas macroporosas de oro metálico sin utilizar un agente reductor externo ni un soporte poroso. Todos estos materiales se han caracterizado por XRD, TEM, SEM y EDAX. [source] Hetero-Seeding and Solid Mixture to Obtain New Crystalline FormsCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2009Dario Braga Prof. Abstract Para -methyl benzyl alcohol (p -MeBA,II) and para -chloro benzyl alcohol (p -ClBA) are quasi-isostructural and share the same hydrogen-bond patterns, but their crystals are not isomorphous. No new polymorphs could be obtained by conventional polymorph screening based on different solvents and different crystallization conditions. Formation of a new polymorph of p -MeBA named p -MeBA,I, isomorphous with the crystal of p -ClBA, was induced by hetero-seeding with a small quantity of powdered p -ClBA added to a supersaturated solution of p -MeBA in hexane, while seeding of p -ClBA with p -MeBA,II failed to give a new phase of p -ClBA isomorphous with known crystalline p -MeBA,II. Mixed crystals of p -MeBA and p -ClBA were also prepared with different p -MeBA/p -ClBA ratios to understand the role of the different functional groups in the crystal structure. Crystal phases were characterized by combined use of single-crystal and powder X-ray diffraction, differential scanning calorimetry, and solid-state NMR spectroscopy. [source] Identification of paramyosin T cell epitopes associated with human resistance to Schistosoma mansoni reinfectionCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005C. T. Fonseca Summary Paramyosin, a Schistosoma mansoni myoprotein associated with human resistance to infection and reinfection, is a candidate antigen to compose a subunit vaccine against schistosomiasis. In this study, 11 paramyosin peptides selected by TEPITOPE algorithm as promiscuous epitopes were produced synthetically and tested in proliferation and in vitro human leucocyte antigen (HLA)-DR binding assays. A differential proliferative response was observed in individuals resistant to reinfection compared to individuals susceptible to reinfection in response to Para (210,226) peptide stimulation. In addition, this peptide was able to bind to all HLA-DR molecules tested in HLA-DR binding assays, confirming its promiscuity. Para (6,22) and Para (355,371) were also shown to be promiscuous peptides, because they were able to bind to the six and eight most prevalent HLA-DR alleles used in HLA-DR binding assays, respectively, and were also recognized by T cells of the individuals studied. These results suggest that these paramyosin peptides are promising antigens to compose an anti-schistosomiasis vaccine. [source] Paras, Palaces, Pathogens: frameworks for the growth of Calcutta, 1800,1850CITY & SOCIETY, Issue 1 2000John Archer THE HISTORICAL FABRIC OF CALCUTTA incorporates both the perspective of indigenous knowledges and practices, as well as successive regimes of "improvements" that British colonial authorities sought to introduce in the period 1798-1850. In the face of these diverse interests the urban fabric served as a crurial medium for the negotiation of difference. Portions of the indigenous population selectively adapted their budding designs and social practices to British conventions, while protecting other patterns and practices in efforts both to accommodate and to maintain difference. [Colonial cities, urban planning, hygiene, India, Calcutta] [source] Ozone cracking and flex cracking of crosslinked polymer blend compoundsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007M. F. Tse Abstract Ozone cracking and flex cracking of crosslinked elastomer blends of brominated isobutylene/para -methylstyrene copolymer (BIMSM) and unsaturated elastomers, such as polybutadiene rubber (BR) and natural rubber (NR), are studied. This saturated BIMSM elastomer, which is a terpolymer of isobutylene, para -bromomethylstyrene, and para -methylstyrene, functions as the ozone-inert phase of the blend. Ozone cracking is measured by the failure time of a tapered specimen under a fixed load in a high severity ozone oven, whereas flex cracking is ranked by the De Mattia cut growth. The ozone resistance of BIMSM/BR/NR blends is compared to that of a BR/NR blend (with or without antiozonant) at constant strain energy densities. The effects of the BIMSM content in the blend, the structural variations of BIMSM, and the network chain length between crosslinks on these two failure properties, which are important in crosslinked compounds for applications in tire sidewalls, are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2183,2196, 2007 [source] Stable Ion and Electrophilic Substitution (Nitration and Bromination) Study of A-Ring Substituted Phenanthrenes: Novel Carbocations and Substituted Derivatives; NMR, X-ray Analysis, and Comparative DNA BindingEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2007Cédric Brulé Abstract Persistent carbocations were generated from five A-ring mono- and di-substituted phenanthrenes [3-OMe; 4-OMe, 1,3-bis(OMe), 2,4-bis(OMe), and 1,3-bis(Me)]. In all cases protonation occurs in the A-ring, ortho/para relative to methoxy or methyl substituent(s). Complete NMR assignments of the resulting carbocations are reported and their charge delocalization modes are discussed. Mild nitration (with 20,50,% aqueous HNO3 at ,10 °C or at room temp.) and bromination (NBS/MeCN/room temp.) of these substrates resulted in the synthesis of several novel mononitro-/dinitro- as well as monobromo/dibromo derivatives, including those with nitro or bromo substituent in the bay-region. Correspondence between the site of attack in low-temperature protonation study and nitro substitution in ambient mild nitrations are examined. Complete NMR assignments for the new derivatives are reported as well as X-ray structures for 2,4-dimethoxy-1-nitro- and 1,3-dimethyl-4-nitrophenanthrenes. A comparative DNA binding study with MCF cells on three of the synthesized mononitro and one dinitro derivative showed that 1,3-dimethyl-9-nitro- (nitro at the meso position), 3-methoxy-4-nitro- (nitro in bay-region), and 1,3-dimethoxy-4,9-dinitrophenanthrenes (nitro in both meso and bay-regions) formed DNA adducts. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Synthesis of poly(1-hexene)s end-functionalized with phenolsPOLYMER INTERNATIONAL, Issue 9 2005Mallinamadugu J Yanjarappa Abstract Electrophilic alkylations of phenol/2,6-dimethylphenol were performed with vinylidene-terminated poly(1-hexene)s using BF3·OEt2 catalyst. Vinylidene-terminated poly(1-hexene)s with Mn varying from 400 to 10000 were prepared by bulk polymerization of 1-hexene at 50 to ,20 °C using Cp2ZrCl2/MAO catalysts. The phenol/2,6-dimethylphenol-terminated poly(1-hexene)s was characterized by NMR (1H, 13C), UV, IR and vapor phase osmometer (VPO). The isomer distribution (ortho, para and ortho/para) was determined by 13P NMR using a phosphitylating reagent, namely 2-chloro-1,3,2-dioxaphospholane. The number-average degree of functionality (Fn) >0.9 with >95% para selectivity could be achieved using low-molecular-weight oligomers of poly(1-hexene)s. Copyright © 2005 Society of Chemical Industry [source] The ParB protein of Streptomyces coelicolor A3(2) recognizes a cluster of parS sequences within the origin-proximal region of the linear chromosomeMOLECULAR MICROBIOLOGY, Issue 5 2002Dagmara Jakimowicz Summary The mycelial prokaryote Streptomyces coelicolor A3(2) possesses a large linear chromosome (8.67 Mb) with a centrally located origin of replication (oriC). Recently, chromosome partitioning genes (parA and parB) and putative ParB binding sites (parS sequences) were identified in its genome. The S. coelicolor chromosome contains more parS sequences than any other bacterial chromosome characterized so far. Twenty of the 24 parS sequences are densely packed within a relatively short distance (, 200 kb) around oriC. A series of in vitro and in vivo experiments showed that S. coelicolor ParB protein interacts specifically with the parS sequences, albeit with a rather low affinity. Our results suggested that the binding of ParB is not only determined by the parS sequence, but also by the location of target DNA close to oriC. The unusually high number and close proximity to each other of the parS sites, together with in vivo and in vitro evidence that multiple ParB molecules may assemble along the DNA from an initial ParB,parS complex, suggest that a large DNA segment around the replication origin may form a massive nucleoprotein complex as part of the replication-partitioning cycle. [source] Academic Research Training for a Nonacademic Workplace: a Case Study of Graduate Student Alumni Who Work in ConservationCONSERVATION BIOLOGY, Issue 6 2009MATTHEW J. MUIR educación en conservación; formación de graduados; habilidades para el trabajo; programas universitarios Abstract:,Graduate education in conservation biology has been assailed as ineffective and inadequate to train the professionals needed to solve conservation problems. To identify how graduate education might better fit the needs of the conservation workplace, we surveyed practitioners and academics about the importance of particular skills on the job and the perceived importance of teaching those same skills in graduate school. All survey participants (n = 189) were alumni from the University of California Davis Graduate Group in Ecology and received thesis-based degrees from 1973 to 2008. Academic and practitioner respondents clearly differed in workplace skills, although there was considerably more agreement in training recommendations. On the basis of participant responses, skill sets particularly at risk of underemphasis in graduate programs are decision making and implementation of policy, whereas research skills may be overemphasized. Practitioners in different job positions, however, require a variety of skill sets, and we suggest that ever-increasing calls to broaden training to fit this multitude of jobs will lead to a trade-off in the teaching of other skills. Some skills, such as program management, may be best developed in on-the-job training or collaborative projects. We argue that the problem of graduate education in conservation will not be solved by restructuring academia alone. Conservation employers need to communicate their specific needs to educators, universities need to be more flexible with their opportunities, and students need to be better consumers of the skills offered by universities and other institutions. Resumen:,La educación en biología de la conservación a nivel licenciatura ha sido calificada como ineficaz e inadecuada para formar a los profesionales que se requieren para resolver problemas de conservación. Para identificar cómo la educación a nivel licenciatura puede satisfacer las necesidades del ámbito laboral en conservación, sondeamos a profesionales y académicos sobre la importancia de habilidades particulares del trabajo y la percepción de la importancia de esas mismas habilidades en la universidad. Todos los participantes en el sondeo (n = 189) fueron alumnos del Grupo de Graduados en Ecología de la Universidad de California en Davis y obtuvieron el grado basado en tesis entre 1973 y 2008. Los académicos y profesionales encuestados difirieron claramente en sus habilidades, aunque hubo considerablemente mayor acuerdo en las recomendaciones de capacitación. Con base en las respuestas de los participantes, los conjuntos de habilidades en riesgo de no ser consideradas en los programas educativos son la toma de decisiones y la implementación de políticas, mientras que las habilidades de investigación tienden a ser sobre enfatizadas. Sin embargo, los profesionales en diferentes puestos de trabajo requieren una variedad de conjuntos de habilidades, y sugerimos que los constantes llamados a ampliar la capacitación para responder a esta multitud de labores conducirán a un desbalance en la enseñanza de otras habilidades. Algunas habilidades, como el manejo de programas, pueden desarrollarse en proyectos colaborativos o de capacitación en el trabajo. Argumentamos que el problema de la educación en biología de la conservación a nivel licenciatura no se resolverá solo con la reestructuración de la academia. Los empleadores deben comunicar sus requerimientos específicos a los educadores, las universidades deben ser más flexibles con sus oportunidades y los estudiantes necesitan ser mejores consumidores de las habilidades ofrecidas por las universidades y otras instituciones. [source] The Need to Rationalize and Prioritize Threatening Processes Used to Determine Threat Status in the IUCN Red ListCONSERVATION BIOLOGY, Issue 6 2009MATT W. HAYWARD carnivora; competencia; estatus de conservación; procesos amenazantes Abstract:,Thorough evaluation has made the International Union for Conservation of Nature (IUCN) Red List the most widely used and accepted authority on the conservation status of biodiversity. Although the system used to determine risk of extinction is rigorously and objectively applied, the list of threatening processes affecting a species is far more subjectively determined and has not had adequate review. I reviewed the threats listed in the IUCN Red List for randomly selected groups within the three most threatened orders of mammals: Artiodactyla, Carnivora, and Primates. These groups are taxonomically related and often ecologically similar, so I expected they would suffer relatively similar threats. Hominoid primates and all other terrestrial fauna faced similar threats, except for bovine artiodactyls and large, predatory carnivores, which faced significantly different threats. Although the status of bovines and hominoids and the number of threats affecting them were correlated, this was not the case for large carnivores. Most notable, however, was the great variation in the threats affecting individual members of each group. For example, the endangered European bison (Bison bonasus) has no threatening processes listed for it, and the lion (Panthera leo) is the only large predator listed as threatened with extinction by civil war. Some threatening processes appear spurious for the conservation of the species, whereas other seemingly important factors are not recorded as threats. The subjective nature of listing threatening processes, via expert opinion, results in substantial biases that may be allayed by independent peer review, use of technical manuals, consensus among multiple assessors, incorporation of probability modeling via decision-tree analysis, and adequate coordination among evaluators. The primary focus should be on species-level threats rather than population-level threats because the IUCN Red List is a global assessment and smaller-scale threats are more appropriate for national status assessments. Until conservationists agree on the threats affecting species and their relative importance, conservation action and success will be hampered by scattering scarce resources too widely and often by implementing conflicting strategies. Resumen:,La evaluación exhaustiva ha hecho que la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN) sea la autoridad más aceptada y ampliamente utilizada respecto al estatus de conservación de la biodiversidad. Aunque el sistema utilizado para determinar el riesgo de extinción es aplicado rigurosa y objetivamente, la lista de procesos amenazantes que afectan a las especies es determinado muy subjetivamente y no es revisado adecuadamente. Revisé las amenazas consideradas en la Lista Roja UICN para grupos seleccionados aleatoriamente en los tres órdenes de mamíferos más amenazados: Artyodactila, Carnivora y Primates. Estos grupos están relacionados taxonómicamente y a menudo son ecológicamente similares, así que esperaba que tuvieran amenazas relativamente similares. Los primates homínidos y toda la demás fauna terrestre enfrentan amenazas similares, excepto por los bovinos artiodáctilos y los carnívoros depredadores mayores, que enfrentan amenazas significativamente diferentes. Aunque el estatus de los bovinos y homínidos y el número de amenazas que los afectan estuvieron correlacionados, este no fue el caso para los carnívoros mayores. Sin embargo, lo más notable fue la gran variación en las amenazas que afectan a miembros individuales de cada grupo. Por ejemplo, no hay procesos amenazantes enlistados para el bisonte europeo (Bison bonasus), y el león (Panthera leo) es el único depredador mayor enlistado como amenazado de extinción por la guerra civil. Algunos procesos amenazantes parecen espurios para la conservación de las especies, mientras que otros factores aparentemente importantes no están registrados como amenazas. La naturaleza subjetiva de los procesos de enlistado, por medio de la opinión de expertos, resulta en sesgos sustanciales que pueden disiparse por la revisión independiente por pares, el uso de manuales técnicos, el consenso de múltiples asesores, la incorporación del modelado probabilístico mediante análisis de árboles de decisión y la adecuada coordinación entre evaluadores. El enfoque principal debería ser sobre amenazas a nivel de especies en lugar de amenazas a nivel de poblaciones porque la Lista Roja UICN es una evaluación global y las amenazas a menor escala son más apropiadas para evaluaciones nacionales de estatus. Hasta que los conservacionistas estén de acuerdo sobre las amenazas que afectan a las especies y su importancia relativa, las acciones de conservación y su éxito estarán obstaculizados por la dispersión demasiado amplia de recursos limitados y a menudo por la implementación de estrategias contrapuestas. [source] Patch-Occupancy Modeling as a Method for Monitoring Changes in Forest Floristics: a Case Study in Southeastern AustraliaCONSERVATION BIOLOGY, Issue 3 2009TRENT D. PENMAN fuego prescrito; manejo adaptativo; modelo Bayesiamo; silvicultura; tala Abstract:,The ability to monitor changes in biodiversity is fundamental to demonstrating sustainable management practices of natural resources. Disturbance studies generally focus on responses at the plot scale, whereas landscape-scale responses are directly relevant to the development of sustainable forest management. Modeling changes in occupancy is one way to monitor landscape-scale responses. We used understory vegetation data collected over 16 years from a long-term study site in southeastern Australia. The site was subject to timber harvesting and frequent prescribed burning. We used occupancy models to examine the impacts of these disturbances on the distribution of 50 species of plants during the study. Timber harvesting influenced the distribution of 9 species, but these effects of harvesting were generally lost within 14 years. Repeated prescribed fire affected 22 species, but the heterogeneity of the burns reduced the predicted negative effects. Twenty-two species decreased over time independent of treatment, and only 5 species increased over time. These changes probably represent a natural response to a wildfire that occurred in 1973, 13 years before the study began. Occupancy modeling is a useful and flexible technique for analyzing monitoring data and it may also be suitable for inclusion within an adaptive-management framework for forest management. Resumen:,La habilidad para monitorear cambios en la biodiversidad es fundamental para demostrar el manejo sustentable de los recursos naturales. Los estudios de perturbación generalmente enfocan las respuestas a escala de parcela, mientras que las respuestas a escala de paisaje son directamente relevantes para el desarrollo del manejo sustentable de bosques. El modelado de cambios en la ocupación es una forma de monitorear respuestas a escala de paisaje. Utilizamos datos de la vegetación de sotobosque colectados a los largo de 16 años en un sitio de estudio a largo plazo en el sureste de Australia. El sitio fue sujeto a la cosecha de madera y a quemas prescritas frecuentes. Utilizamos modelos de ocupación para examinar los impactos de estas perturbaciones sobre la distribución de 50 especies de plantas. La cosecha de madera influyó en la distribución de nueve especies, pero los efectos de la cosecha generalmente se perdieron al cabo de 14 años. El fuego prescrito repetido afectó a 22 especies, pero la heterogeneidad de las quemas redujo los efectos negativos pronosticados. Veintidós especies decrecieron en el tiempo independientemente del tratamiento, y solo cinco especies incrementaron en el tiempo. Estos cambios probablemente representan una respuesta natural al incendio no controlado que ocurrió en 1973, 13 años antes de que comenzara el estudio. El modelado de la ocupación es una técnica útil y flexible para analizar datos de monitoreo y también puede ser adecuado para su inclusión en un marco de manejo adaptativo para la gestión de bosques. [source] Consumer Control of Salt Marshes Driven by Human DisturbanceCONSERVATION BIOLOGY, Issue 3 2008MARK D. BERTNESS control de consumidor; impactos humanos; conservación de pantano de sal; cascadas de trophic Abstract:,Salt marsh ecosystems are widely considered to be controlled exclusively by bottom,up forces, but there is mounting evidence that human disturbances are triggering consumer control in western Atlantic salt marshes, often with catastrophic consequences. In other marine ecosystems, human disturbances routinely dampen (e.g., coral reefs, sea grass beds) and strengthen (e.g., kelps) consumer control, but current marsh theory predicts little potential interaction between humans and marsh consumers. Thus, human modification of top,down control in salt marshes was not anticipated and was even discounted in current marsh theory, despite loud warnings about the potential for cascading human impacts from work in other marine ecosystems. In spite of recent experiments that have challenged established marsh dogma and demonstrated consumer-driven die-off of salt marsh ecosystems, government agencies and nongovernmental organizations continue to manage marsh die-offs under the old theoretical framework and only consider bottom,up forces as causal agents. This intellectual dependency of many coastal ecologists and managers on system-specific theory (i.e., marsh bottom,up theory) has the potential to have grave repercussions for coastal ecosystem management and conservation in the face of increasing human threats. We stress that marine vascular plant communities (salt marshes, sea grass beds, mangroves) are likely more vulnerable to runaway grazing and consumer-driven collapse than is currently recognized by theory, particularly in low-diversity ecosystems like Atlantic salt marshes. Resumen:,Se ha considerado extensamente que los ecosistemas de marismas son controlados exclusivamente por dinámicas abajo-arriba, pero se ha acumulado evidencia de que las perturbaciones humanas están provocando el control por consumidores en marismas del Atlántico occidental, a menudo con consecuencias catastróficas. En otros ecosistemas marinos, las perturbaciones humanas rutinariamente disminuyen (e.g., arrecifes de coral, pastos marinos) y refuerzan (e.g., varec) el control por consumidores, pero la teoría de marismas actual predice una leve interacción potencial entre humanos y consumidores en las marismas. Por lo tanto, las modificaciones humanas al control arriba-abajo en las marismas no estaba anticipada y aun era descontada en la teoría de marismas actual, a pesar de advertencias sobre el potencial de impactos humanos en cascada en trabajos en otros ecosistemas marinos. No obstante los experimentos recientes que han desafiado el dogma de marismas establecido y que han demostrado la desaparición gradual de marismas conducida por consumidores, las agencias gubernamentales y las organizaciones no gubernamentales continúan manejando la disminución de marismas en el marco de la teoría vieja y sólo consideran como agentes causales a factores abajo-arriba. Esta dependencia intelectual en la teoría sistema-específico (i.e., teoría de marismas abajo-arriba) de muchos ecólogos y manejadores costeros tiene el potencial de tener repercusiones graves para el manejo y conservación de ecosistemas costeros frente a las crecientes amenazas humanas. Enfatizamos que las comunidades plantas vasculares marinas (marismas, pastos marinos, manglares) son potencialmente más vulnerables al pastoreo descontrolado y al colapso conducido por consumidores que lo que reconoce la teoría actualmente, particularmente en ecosistemas con baja diversidad como las marismas del Atlántico. [source] Epidemiologic Analysis of Factors Associated with Local Disappearances of Native Ranid Frogs in ArizonaCONSERVATION BIOLOGY, Issue 2 2008CARMEL L. WITTE análisis de factores de riesgo; declinación de anfibios; declinación de ranas; epidemiología de vida silvestre; métodos de control de casos Abstract:,We examined factors that may independently or synergistically contribute to amphibian population declines. We used epidemiologic case,control methodology to sample and analyze a large database developed and maintained by the Arizona Game and Fish Department that describes historical and currently known ranid frog localities in Arizona, U.S.A. Sites with historical documentation of target ranid species (n= 324) were evaluated to identify locations where frogs had disappeared during the study period (case sites) and locations where frog populations persisted (control sites). Between 1986 and 2003, 117 (36%) of the 324 sites became case sites, of which 105 were used in the analyses. An equal number of control sites were sampled to control for the effects of time. Risk factors, or predictor variables, were defined from environmental data summarized during site surveys and geographic information system data layers. We evaluated risk factors with univariate and multifactorial logistic-regression analyses to derive odds ratios (OR). Odds for local population disappearance were significantly related to 4 factors in the multifactorial model. Disappearance of frog populations increased with increasing elevation (OR = 2.7 for every 500 m, p < 0.01). Sites where disappearances occurred were 4.3 times more likely to have other nearby sites that also experienced disappearances (OR = 4.3, p < 0.01), whereas the odds of disappearance were 6.7 times less (OR = 0.15, p < 0.01) when there was a source population nearby. Sites with disappearances were 2.6 times more likely to have introduced crayfish than were control sites (OR = 2.6, p= 0.04). The identification of factors associated with frog disappearances increases understanding of declines occurring in natural populations and aids in conservation efforts to reestablish and protect native ranids by identifying and prioritizing implicated threats. Resumen:,Examinamos los factores que pueden contribuir independiente o sinérgicamente a la declinación de poblaciones de anfibios. Utilizamos una metodología epidemiológica de control de casos para muestrear y analizar una base de datos desarrollada y mantenida por el Departamento de Caza y Pesca de Arizona que describe las localidades históricas y actuales de ranas en Arizona, E. U. A. Los sitios con documentación histórica de las especies de ránidos (n= 324) fueron evaluados para identificar localidades donde las ranas desaparecieron durante el período de estudio (sitios caso) y localidades donde las poblaciones de ranas persistieron (sitios control). Entre 1986 y 2003, 36% (117) de los 324 sitios se volvieron sitios caso, de los cuales 105 fueron utilizados en los análisis. El mismo número de sitios control fueron muestreados para controlar los efectos del tiempo. Los factores de riesgo, o variables predictivas, fueron definidos a partir de datos ambientales obtenidos de los muestreos en los sitios y de capas de datos de un sistema información geográfica. Evaluamos los factores de riesgo con análisis de regresión logística univariada y multivariada para derivar proporciones de probabilidades (PP). Las probabilidad para la desaparición de una población local estuvo relacionada significativamente con 4 factores en el modelo multifactorial. La desaparición de poblaciones de ranas incrementó con la elevación (PP = 2.7 por cada 500 m, p < 0.01). Los sitios donde ocurrieron las desapariciones fueron 4.3 veces más propensos a estar cerca de otros sitios donde ocurrieron desapariciones (PP = 4.3, p < 0.01), mientras que la probabilidad de desaparición fue 6.7 veces menos (PP = 0.15, p < 0.01) cuando había una población fuente cercana. Los sitios con desapariciones fueron 2.6 veces más propensos a tener langostinos introducidos que los sitios control (PP = 2.6, p= 0.04). La identificación de factores asociados con la desaparición de ranas incrementa el conocimiento de las declinaciones de poblaciones naturales y ayuda a los esfuerzos de conservación para el reestablecimiento y la protección de ránidos nativos mediante la identificación y priorización de las amenazas implicadas. [source] | |||||||||||||||||||||||||||||||||||||||||||