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Diverse
Kinds of Diverse Terms modified by Diverse Selected AbstractsHOW DID LIFE BECOME SO DIVERSE?PALAEONTOLOGY, Issue 1 2007THE DYNAMICS OF DIVERSIFICATION ACCORDING TO THE FOSSIL RECORD AND MOLECULAR PHYLOGENETICS Abstract:, The long-term diversification of life probably cannot be modelled as a simple equilibrial process: the time scales are too long, the potential for exploring new ecospace is too large and it is unlikely that ecological controls can act at global scales. The sum of many clade expansions and reductions, each of which happens according to its own dynamic, probably approximates more a damped exponential curve when translated into a global-scale species diversification curve. Unfortunately, it is not possible to plot such a meaningful global-scale species diversification curve through time, but curves at higher taxonomic levels have been produced. These curves are subject to the vagaries of the fossil record, but it is unlikely that the sources of error entirely overwhelm the biological signal. Clades radiate when the external and internal conditions are right: a new territory or ecospace becomes available, and the lineage has acquired a number of characters that open up a new diet or mode of life. Modern high levels of diversity in certain speciose clades may depend on such ancient opportunities taken. Dramatic climatic changes through the Quaternary must have driven extinctions and originations, but many species responded simply by moving to more favourable locations. Ecological communities appear to be no more than merely chance associations of species, but there may be real interactions among species. Ironically, high species diversity may lead to more speciation, not, as had been assumed, less: more species create more opportunities and selective pressures for other species to respond to, rather than capping diversity at a fixed equilibrium level. Studies from the scale of modern ecosystems to global long-term patterns in the fossil record support a model for the exponential diversification of life, and one explanation for a pattern of exponential diversification is that as diversity increases, new forms become ever more refinements of existing forms. In a sense the world becomes increasingly divided into finer niche space. Organisms have a propensity to speciate freely, species richness within ecosystems appears to generate opportunities for more speciation, clades show all kinds of patterns from sluggish speciation rates and constant diversity through time to apparently explosive speciation, and there is no evidence that rapidly speciating clades have reached a limit, nor that they are driving other clades to extinction. A corollary of this view is that current biodiversity must be higher than it has ever been. Limits to infinite growth are clearly local, regional, and global turnover and extinction events, when climate change and physical catastrophes knock out species and whole clades, and push the rising exponential curve down a notch or two. [source] Cover Picture: Electrophoresis 7'2010ELECTROPHORESIS, Issue 7 2010Article first published online: 26 MAR 2010 Issue no. 7 is a special issue on CE-MS consisting of "19 manuscripts subdivided into three major categories: one devoted to instrumental and methodical advances, two providing an insight into up-to-date applications from the fields of technical and natural products, food and environmental analysis on the one hand and biomedical and pharmaceutical analysis on the other hand. Diverse approaches how CE-MS can be employed for the solution of various analytical problems can be found in these papers. Different modes of electroseparation techniques in the capillary format such as CZE, CEC or MEEKC are coupled to various MS instruments ranging from simple quadrupole MS instruments to state of the art QTOF's, using a range of interfaces such as ESI, ICP or APPI. So this special issue will again try to present an overview of current trends and developments in the fields of CE-MS" [source] The Early and Middle Miocene transgression at the southern border of the North Sea Basin (northern Belgium)GEOLOGICAL JOURNAL, Issue 4 2005Stephen Louwye Abstract The Lower,Middle Miocene Berchem Formation of northern Belgium is an essentially sandy sequence with a varying glauconite content and often abundant shelly intervals. The formation was deposited in a shallow marine environment and rests unconformably on stiff Rupelian clays or Chattian sands. The lithological recognition of the four members (Edegem Sands, Kiel Sands, Antwerpen Sands and Zonderschot Sands members) of the Berchem Formation solely based on lithological criteria proved to be difficult, especially in boreholes. The geometry of the Formation in the subsurface of northern Belgium remained largely unknown. Diverse and well preserved dinoflagellate cyst associations have been recovered from the four members in seven boreholes and two outcrops, and allow a refinement of the biostratigraphy of these deposits. A Miocene biozonation defined in mid-latitude shallow marine deposits in the Atlantic Coastal Plain of the USA (Salisbury Embayment, Maryland) is readily applicable to this material, and has led to a detailed stratigraphic assessment of each member. Three detailed profiles depicting the distribution of the biozones in the subsurface of northern Belgium allow the reconstruction of the geometry and depositional history of the Berchem Formation. The oldest Miocene deposits are of early Burdigalian age and they testify to a transgression, which invaded Belgium from a north,northwestern direction. The maximum flooding took place during early Serravallian times. The upper boundary of the formation is a major erosional surface of late Serravallian or (slightly) younger age. Copyright © 2005 John Wiley & Sons, Ltd. [source] Legitimately Diverse, yet Comparable: On Synthesizing Social Inclusion Performance in the EU,JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 5 2004LAURENS CHERCHYE The open method of co-ordination (OMC) intends to enhance EU Member States'performance on social inclusion. In this context a set of commonly agreed performance indicators plays an important role. While the communicative power of a synthetic indicator has been recognized, several objections have been raised against such a construction. In this article, we argue that a set of separate indicators can in principle be combined into a meaningful synthetic performance index without giving up on the notion of subsidiarity, and without fundamentally impairing the peer pressure incentives that constitute an important rationale for OMC. We complement the presentation of the conceptual framework with a number of empirical applications, thereby indicating how the basic method may be instrumental for policy benchmarking practice. [source] The Hermitage ,,Diverse and Vast ,'MUSEUM INTERNATIONAL, Issue 1 2003George Vilinbakhov [source] Highly Enantioselective Recognition of Structurally Diverse ,-Hydroxycarboxylic Acids using a Fluorescent Sensor,ANGEWANDTE CHEMIE, Issue 3 2010Hai-Lin Liu Leuchtendes Beispiel: Der leicht erhältliche Binol-Aminoalkohol (S)- 1 ist eine hoch enantioselektive Fluoreszenzsonde für strukturell diverse ,-Hydroxycarbonsäuren. (S)- 1 erkennt als erste hoch enantioselektive Fluoreszenzsonde lineare aliphatische ,-Hydroxycarbonsäuren und ,-Hydroxycarbonsäuren mit tertiären Kohlenstoffzentren in ,-Stellung. [source] Suzuki Cross-Coupling on Enantiomerically Pure Epoxides: Efficient Synthesis of Diverse, Modular Amino Alcohols from Single Enantiopure Precursors.CHEMINFORM, Issue 34 2007Xavier Cattoen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] 1,3,5-Triazepan-2,6-diones as Structurally Diverse and Conformationally Constrained Dipeptide Mimetics: Identification of Malaria Liver Stage Inhibitors from a Small Pilot LibraryCHEMISTRY - A EUROPEAN JOURNAL, Issue 33 2006Gersande Lena Abstract The development of the 1,3,5-triazepan-2,6-dione system as a novel, conformationally restricted, and readily accessible class of dipeptidomimetics is reported. The synthesis of the densely functionalized 1,3,5-triazepan-2,6-dione skeleton was achieved in only four steps from a variety of simple linear dipeptide precursors. To extend the practical value of 1,3,5-triazepane-2,6-diones, a general polymer-assisted solution-phase synthesis approach amenable to library production in a multiparallel format was developed. The conformational preferences of the 1,3,5-triazepan-2,6-dione skeleton were investigated in detail by NMR spectroscopy and X-ray diffraction. The ring exhibits a characteristic folded conformation which was compared to that of related dipeptide-derived scaffolds including the more planar 2,5-diketopiperazine (DKP). Molecular and structural diversity was increased further through post-cyclization appending operations at urea nitrogens. Preliminary biological screens of a small collection of 1,3,5-triazepan-2,6-diones revealed inhibitors of the underexplored malaria liver stage and suggest strong potential for this dipeptide-derived scaffold to interfere with and to modulate biological pathways. [source] Considering religion and beliefs in child protection and safeguarding work: is any consensus emerging?CHILD ABUSE REVIEW, Issue 2 2009Philip Gilligan Abstract Diverse, but significant, phenomena have combined to raise both the profile of issues related to religion and child abuse and the need for professionals to understand and respond appropriately to them. The nature of some of these issues is explored and attempts made to clarify them. Data collected by the author primarily from questionnaires completed by professionals involved in child protection and safeguarding work are analysed and discussed. Some patterns are identified and explored. Finally, it is suggested that, despite the apparent emergence of a more general recognition and acknowledgement of these issues amongst many professionals, relevant day-to-day practice remains largely dependent on individual views and attitudes. Moreover, practitioners are able to continue with ,religion-blind' and ,belief-blind' approaches without these being significantly challenged by agency policies or by professional cultures. Copyright © 2009 John Wiley & Sons, Ltd. [source] The ASCI Computational Grid: initial deploymentCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13-15 2002Randal Rheinheimer Abstract Grid Services, a Department of Energy Accelerated Strategic Computing Initiative program, has designed, implemented, and deployed a grid-based solution for customer access to large computing resources at DOE weapons labs and plants. Customers can access and monitor diverse, geographically distributed resources using the common Grid Services interfaces. This paper discusses the architecture, security, and user interfaces of the Grid Services infrastructure. Published in 2002 by John Wiley & Sons, Ltd. [source] Probing the corticospinal link between the motor cortex and motoneurones: some neglected aspects of human motor cortical functionACTA PHYSIOLOGICA, Issue 4 2010N. C. Petersen Abstract This review considers the operation of the corticospinal system in primates. There is a relatively widespread cortical area containing corticospinal outputs to a single muscle and thus a motoneurone pool receives corticospinal input from a wide region of the cortex. In addition, corticospinal cells themselves have divergent intraspinal branches which innervate more than one motoneuronal pool but the synergistic couplings involving the many hand muscles are likely to be more diverse than can be accommodated simply by fixed patterns of corticospinal divergence. Many studies using transcranial magnetic stimulation of the human motor cortex have highlighted the capacity of the cortex to modify its apparent excitability in response to altered afferent inputs, training and various pathologies. Studies using cortical stimulation at ,very low' intensities which elicit only short-latency suppression of the discharge of motor units have revealed that the rapidly conducting corticospinal axons (stimulated at higher intensities) drive motoneurones in normal voluntary contractions. There are also major non-linearities generated at a spinal level in the relation between corticospinal output and the output from the motoneurone pool. For example, recent studies have revealed that the efficacy of the human corticospinal connection with motoneurones undergoes activity-dependent changes which influence the size of voluntary contractions. Hence, corticospinal drives must be sculpted continuously to compensate for the changing functional efficacy of the descending systems which activate the motoneurones. This highlights the need for proprioceptive monitoring of movements to ensure their accurate execution. [source] An HPLC/mass spectrometry platform for the development of multimodality contrast agents and targeted therapeutics: prostate-specific membrane antigen small molecule derivativesCONTRAST MEDIA & MOLECULAR IMAGING, Issue 5 2006Valerie Humblet Abstract The production of disease-targeted agents requires the covalent conjugation of a targeting molecule with a contrast agent or therapeutic, followed by purification of the product to homogeneity. Typical targeting molecules, such as small molecules and peptides, often have high charge-to-mass ratios and/or hydrophobicity. Contrast agents and therapeutics themselves are also diverse, and include lanthanide chelates for MRI, 99mTc chelates for SPECT, 90Y chelates for radiotherapy, 18F derivatives for PET, and heptamethine indocyanines for near-infrared fluorescent optical imaging. We have constructed a general-purpose HPLC/mass spectrometry platform capable of purifying virtually any targeted agent for any modality. The analytical sub-system is composed of a single dual-head pump that directs mobile phase to either a hot cell for the purification of radioactive agents or to an ES-TOF MS for the purification of nonradioactive agents. Nonradioactive agents are also monitored during purification by ELSD, absorbance and fluorescence. The preparative sub-system is composed of columns and procedures that permit rapid scaling from the analytical system. To demonstrate the platform's utility, we describe the preparation of five small molecule derivatives specific for prostate-specific membrane antigen (PSMA): a gadolinium derivative for MRI, indium, rhenium and technetium derivatives for SPECT, and an yttrium derivative for radiotherapy. All five compounds are derived from a highly anionic targeting ligand engineered to have a single nucleophile for N -hydroxysuccinimide-based conjugation. We also describe optimized column/mobile phase combinations and mass spectrometry settings for each class of agent, and discuss strategies for purifying molecules with extreme charge and/or hydrophobicity. Taken together, our study should expedite the development of disease-targeted, multimodality diagnostic and therapeutic agents. Copyright © 2006 John Wiley & Sons, Ltd. [source] Making sense of CSR communicationCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 3 2009Paul Ziek Abstract Although a great deal of research has focused on communicating Corporate Social Responsibility (CSR), the literature is diverse and encompasses a plethora of theories and approaches. It is still unclear what communicative behaviors carry the messages of organizational virtuosity and the implementation of responsible initiatives. What is missing is a simple, inclusive assessment of how organizations explicitly communicate the behaviors that constitute CSR. Accordingly, the purpose of this paper is to provide an illustration of the accounts that constitute CSR communication. Fifty US firms are examined for CSR moves within a variety of organizational contexts. The results show that communicating CSR is limited to large organizations and primarily, that they communicate CSR by conveying information about classically accepted responsible and virtuous behaviors. This patterned communicative behavior is a process that organizations engage in to make sense of CSR. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment. [source] The Relationships Between and Among Teachers' Narrative Knowledge, Communities of Knowing, and School Reform: A Case of "The Monkey's Paw"CURRICULUM INQUIRY, Issue 3 2001Cheryl J. Craig Centering on the monkey's paw metaphor, this narrative inquiry links teachers' pedagogical practices with their professional-development experiences associated with a national reform movement that, in this situation, acted in a top-down manner. The longitudinal study illuminates the short- and long-term influence that the state-directed national reform initiative had on the story of a diverse, U.S. middle school and on the stories its teachers subsequently lived and told. The work particularly focuses on the relationships between and among teachers' knowledge developments, their knowledge communities, and their attitudes toward school reform. [source] Package design in the halls of academiaDESIGN MANAGEMENT REVIEW, Issue 4 2002Joseph Bottoni This is a snapshot of how one school handles the challenge of package design. The work comes from students at the University of Cincinnati. Professor Joseph Bottoni explains that the goals of the concise 10-week assignment are to develop a package with a strong retail presence,clearly conveying content; reaching consumers emotionally, as well as rationally; and responsibly conserving resources. The outcomes are imaginative and diverse. [source] Economic Policy and Women's Informal Work in South AfricaDEVELOPMENT AND CHANGE, Issue 5 2001Imraan Valodia This article examines the gender dimensions of the growth in informal and flexible work in South Africa and the government's policy response to this. It outlines the growth in informal and flexible work practices and, as illustrative examples, analyses how trade and industrial policies and labour market policies are impacting on the growth of informal and flexible work. It is argued that the South African government's trade and industrial policies are shifting the economy onto a path of capital intensification. Allied to this, firms are undergoing a process of extensive restructuring. These developments are further promoting the growth of flexibilization and informalization, and thereby disadvantaging women. The article demonstrates that whilst the government offers a vast package of support measures to big business, its policy is largely irrelevant to the survivalist segment of small business, where most women in the informal economy are to be found. The picture for labour policy is more diverse. Aspects of the labour legislation are promoting the growth of a dual labour market, whilst there seems to be some tightening up of practices aimed at bypassing aspects of the protection provided to workers. [source] Drosophila multiplexin (Dmp) modulates motor axon pathfinding accuracyDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5 2009Frauke Meyer Multiplexins are multidomain collagens typically composed of an N-terminal thrombospondin-related domain, an interrupted triple helix and a C-terminal endostatin domain. They feature a clear regulatory function in the development of different tissues, which is chiefly conveyed by the endostatin domain. This domain can be found in proteolytically released monomeric and trimeric versions, and their diverse and opposed effects on the migratory behavior of epithelial and endothelial cell types have been demonstrated in cell culture experiments. The only Drosophila multiplexin displays specific features of both vertebrate multiplexins, collagens XV and XVIII. We characterized the Drosophila multiplexin (dmp) gene and found that three main isoforms are expressed from it, one of which is the monomeric endostatin version. Generation of dmp deletion alleles revealed that Dmp plays a role in motor axon pathfinding, as the mutants exhibit ventral bypass defects of the intersegmental nerve b (ISNb) similar to other motor axon guidance mutants. Transgenic overexpression of monomeric endostatin as well as of full-length Dmp, but not trimeric endostatin, were able to rescue these defects. In contrast, trimeric endostatin increased axon pathfinding accuracy in wild type background. We conclude that Dmp plays a modulating role in motor axon pathfinding and may be part of a buffering system that functions to avoid innervation errors. [source] Sex determination in fish: Lessons from the sex-determining gene of the teleost medaka, Oryzias latipesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5-6 2003Masaru Matsuda Although sex determination systems in animals are diverse, sex-determining genes have been identified only in mammals and some invertebrates. Recently, DMY (DM domain gene on the Y chromosome) has been found in the sex-determining region on the Y chromosome of the teleost medaka fish, Oryzias latipes. Functional and expression analyses of DMY show it to be the leading candidate for the male-determining master gene of the medaka. Although some work is required to define DMY as the master sex-determining gene, medaka is expected to be a good experimental animal for investigating the precise mechanisms involved in primary sex determination in non-mammalian vertebrates. In this article, the process of identification of DMY and is summarized and the origins of DMY and sexual development of the medaka's gonads are reviewed. In addition, putative functions of DMY are discussed. [source] Acculturation is associated with the prevalence of tardive dyskinesia and akathisia in community-treated patients with schizophreniaACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2008S. Sundram Objective:, Ethnicity is a risk factor for tardive dyskinesia (TD) and other antipsychotic drug-induced movement disorders (ADIMD). It is unclear whether this association is mediated through genetic, environmental or cultural factors individually or in combination. This pilot study aimed to explore this interaction by determining if acculturation in migrant groups contributed to the prevalence of ADIMD. Method:, Culturally diverse but relatively genetically homogeneous (white Caucasian) patients with schizophrenia (n = 40) treated at a single site were assessed for the presence of ADIMD and level of acculturation. Results:, Higher levels of acculturation correlated with an increased prevalence of TD and akathisia but not Parkinsonism. The level of acculturation significantly predicted TD. Conclusion:, This study identifies for the first time that acculturation significantly contributes to the prevalence of TD and akathisia but not Parkinsonism in culturally diverse migrant populations and must be accounted for when explaining ethnic variation in rates of ADIMD. [source] Insulin therapy in type 2 diabetes: what is the evidence?DIABETES OBESITY & METABOLISM, Issue 5 2009Mariëlle J. P. Van Avendonk Aim:, To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus Methods:, A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements. Results:, The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal,bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin. Conclusion:, A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years. [source] Spermiogenesis and spermatozoal ultrastructure in Trichomycteridae (Teleostei: Ostariophysi: Siluriformes)ACTA ZOOLOGICA, Issue 4 2010Maria Angélica Spadella Abstract Spadella, M.A., Oliveira, C. and Quagio-Grassiotto, I. 2009. Spermiogenesis and spermatozoal ultrastructure in Trichomycteridae (Teleostei: Ostariophysi: Siluriformes). ,Acta Zoologica (Stockholm) 91: 373,389. Siluriformes comprises the most diverse and widely distributed ostariophysan group, a fish assemblage that includes about three quarters of the freshwater fish of the world. In this study, the ultrastructural characterization of spermiogenesis and spermatozoa in specimens of Copionodontinae (the sister group to all other trichomycterids), Trichomycterinae (a derived trichomycterid group), and Ituglanis (a genus not assigned to any trichomycterid subfamily) is presented. The comparative analyses of the data show that trichomycterid species share six of seven analyzed spermiogenesis characters, reinforcing the monophyly of the group. Analyses of trichomycterid sperm ultrastructure showed that the species studied share the same character states for nine of seventeen characters analyzed. Copionodon orthiocarinatus and Ituglanis amazonicus each share more ultrastructural characters with species of Trichomycterus than with one another. Regarding the families of Loricarioidea, the species of Trichomycteridae share more characters of spermatogenesis, spermiogenesis, and sperm with representatives of the families Callichthyidae, Loricariidae, and Scoloplacidae than with Nematogenyidae, its hypothesized sister group. With the exception of the family Nematogenyidae, the character similarities observed reinforce the monophyly of the superfamily Loricarioidea. [source] Retrospective endoscopic study of developmental and configurational changes of early colorectal cancer: Eight cases and a review of the literatureDIGESTIVE ENDOSCOPY, Issue 1 2004Toshiyuki Matsui Background:, A retrospective endoscopic follow-up study was conducted to elucidate the development of minute or superficial-type cancers. Methods:, The development of eight colorectal cancers that were followed up by endoscopy was evaluated. Results:, (i) Cancer with high-grade atypia frequently developed from lesions diagnosed histologically by biopsy as adenoma; (ii) two polypoid adenomas developed into invasive cancers with non-polypoid configuration; (iii) a superficial elevated-type cancer with high-grade atypia remained a mucosal cancer for more than 1 year; (iv) a superficial depressed (SD)-type cancer that had a concomitant adenomatous component grew slowly, maintaining the same configuration for more than 2 years. Another SD-type cancer grew rapidly to an advanced cancer; and (v) a superficial elevated adenoma developed into a IIa + IIc-type submucosally invasive cancer while maintaining the size of the initial tumor. From the analysis of the literature, 35 lesions were collected, but it was impossible to speculate which specific type of tumor grew rapidly. Conclusions:, From the endoscopic observations of the present study and the review of the literature, developments of superficial type cancers were diverse, sessile-type cancers with marked configurational change, and early cancers developed slowly, although the speed of their growth accelerated according to the downward invasion of the cancer. [source] The organisation of invertebrate brains: cells, synapses and circuitsACTA ZOOLOGICA, Issue 1 2010Ian A. Meinertzhagen Abstract Meinertzhagen, I.A. 2010. The organisation of invertebrate brains: cells, synapses and circuits. ,Acta Zoologica (Stockholm) 91: 64,71 Invertebrate brains are structurally diverse. Neuron numbers range from ,102 to 108 in different groups, compared with larger numbers in vertebrate brains, ,107 to 1014. The underpopulated brains of invertebrates are noted in their extreme cases for having few cells, and neurons that can be identified from animal to animal, many known in great detail. Although few in number, invertebrate neurons nevertheless comprise many classes. Correlated with the paucity of their number they are sparsely connected, many having ,50 synapses or fewer. Synaptic densities, roughly 1 per ,m3 of neuropile, differ little from those for much larger vertebrate neurons. Invertebrate neurons differ from their vertebrate counterparts in the position of their soma, generally in a cortex surrounding the neuropile that consequently occupies a relatively small volume. Their axons typically lack myelin and, supporting a range of conduction velocities, have diameters that differ over a wide range, from 103 to 10,1,m. Nerves with thousands of axons differ from neuropile fascicles, which typically have 20 or less. Unlike most vertebrate synapses, but like those of the vertebrate retina, synapses in many invertebrate groups , probably all ecdysozoans and possibly some lophotrochozoans , have synaptic contacts with multiple postsynaptic elements, dyads, triads and so on. [source] Evaluating reserves for species richness and representation in northern CaliforniaDIVERSITY AND DISTRIBUTIONS, Issue 4 2006Jeffrey R. Dunk ABSTRACT The Klamath-Siskiyou forests of northern California and southern Oregon are recognized as an area of globally outstanding biological distinctiveness. When evaluated at a national or global level, this region is often, necessarily, considered to be uniformly diverse. Due to large variation in biotic and abiotic variables throughout this region, however, it is unlikely that biological diversity is uniformly distributed. Furthermore, land management decisions nearly always occur at spatial scales smaller than this entire region. Therefore, we used field data from a random sampling design to map the distribution of local and regional richness of terrestrial molluscs and salamanders within northern California's portion of the Klamath-Siskiyou region. We also evaluated the protection afforded by reserves established for varying reasons (e.g. for inspiration and recreation for people vs. species conservation) to hotspots of species richness and species representation of these taxa. No existing reserves were created with these taxa in mind, yet it was assumed that reserves established largely around considerations for the northern spotted owl (Strix occidentalis caurina) would afford adequate protection for many lesser-known species. Species of terrestrial molluscs and salamanders share two general features: (1) they have extremely low vagility, and (2) they are often associated with moist, cool microclimates. Existing reserves disproportionately included areas of hotspots of species richness for both taxa, when hotspots included the richest c. 25% of the area, whereas non-reserved lands contained greater than expected areas with lower species richness. However, when a more strict definition of hotspot was used (i.e. the richest c.10% of areas), local hotspots for both taxa were not disproportionately found in reserves. Reserves set aside largely for human aesthetics and recreation and those set aside for biodiversity both contributed to the protection of areas with high (greatest 25%) species richness. Existing biodiversity reserves represented 68% of mollusc species and 73% of salamander species, corresponding to the 99th and 93rd percentiles, respectively, of species representation achieved by simulating a random distribution of the same total area of reservation. Cumulatively, however, reserves set aside for inspiration and biodiversity represented 83% of mollusc species and 91% of salamander species. The existing reserves provide conservation value for terrestrial molluscs and salamanders. This reserve network, however, should not be considered optimal for either taxa. [source] A quantitative approach to probe the dependence and correlation of food-effect with aqueous solubility, dose/solubility ratio, and partition coefficient (Log P) for orally active drugs administered as immediate-release formulationsDRUG DEVELOPMENT RESEARCH, Issue 2 2005Brahma N. Singh Abstract The purpose of the present review was to systematically evaluate if aqueous solubility, dose/solubility ratio, and partition coefficient (Log P) could be used as useful parameters to quantitatively probe the dependence and correlation of in vivo food effects with these physicochemical properties of orally active drugs administered as immediate-release (IR) formulations. Mean AUC data obtained under fasted and fed states of over 100 structurally diverse orally active drugs with different physicochemical properties were obtained from the primary literature. Correlations of AUC ratio (Fed/Fasted) with aqueous solubility, dose/solubility ratio, and Log P were derived and statistically evaluated by Pearson's correlation test (two-tailed). A negative correlation was obtained between the logarithm of the aqueous solubility and the AUC ratio (r=,0.5982, N=93), whereas a positive correlation existed between AUC ratio and Log P (r=0.5147, N=110) and between AUC ratio and dose/solubility ratio (r=0.5511, N=87). All these correlations were significant (P<0.0001). Based on this study, the estimated range within which a drug is not expected to be significantly affected by food falls between 0.148,89.39 mg/ml for aqueous solubility and between 0.23,624 ml for the dose:solubility ratio. The corresponding range of Log P for expecting a lack of food-effect lies between ,1.13 and 2.98. Quantitatively, the effect of food was most pronounced for lipophilic, poorly water-soluble drugs (with only a few exceptions), irrespective of whether the drug is acidic, basic, or neutral. It is concluded that aqueous solubility, dose/solubility ratio, and partition coefficient can be used as useful parameters to probe the dependence and correlation of food-effect with these physicochemical parameters for immediate-release formulations. Drug Dev. Res. 65:55,75, 2005. © 2005 Wiley-Liss, Inc. [source] Role of meta-analysis of clinical trials for Alzheimer's diseaseDRUG DEVELOPMENT RESEARCH, Issue 3 2002Jesús M. López Arrieta Abstract Alzheimer's disease (AD) is a growing worldwide medical, social, and economic problem. In all countries, both prevalence and incidence of this disorder increase with age. The task of translating scientific clinical research into effective interventions for dementia has proved to be a difficult challenge. Data about the effects of therapeutic interventions come from several sources of evidence, ranging from studies with little potential for systematic bias and minimal random error, such as well-designed randomized controlled trials, through controlled but nonrandomized cohort and case-control studies, all the way to opinions based on laboratory evidence or theory. Although clinical trials are widespread in AD, there is increasing recognition that the results of studies do not necessarily apply to the type of patients that are seen by clinicians because of differences in patient characteristics, comorbidities, cotherapies, severity of disease, compliance, local circumstances, and patients preferences, which may differ sufficiently from those in the trial situation to attenuate or change the benefit-to-risk ratio. There are several methods to address those issues, like pragmatic trials and n-of-1 trials. When data from randomized clinical trials do not provide clear answers from sufficiently similar studies in the magnitude of effect sizes, lack of statistical significance, or identification of subgroups, systematic reviews and meta-analysis may help to provide a better summary of the data. A major difference between a traditional review and a systematic is the systematic nature in which studies are chosen and appraised. Traditional reviews are written by experts in the field who use differing and often subjective criteria to decide what studies to include and what weight to give them, and hence the conclusions are often very diverse, depending on the reviewer. Publication and selection bias is a major concern of traditional reviews. Systematic reviews and meta-analysis are being increasingly used in dementia, propelled by the Cochrane Dementia and Cognitive Improvement Group, to make decisions about treatment, management, and care and to guide future research. This narrative review describes the rationale for randomized clinical trials and systematic reviews in dementia, particularly AD. Drug Dev. Res. 56:401,411, 2002. © 2002 Wiley-Liss, Inc. [source] Morpho-anatomy of the lobopod Magadictyon cf. haikouensis from the Early Cambrian Chengjiang Lagerstätte, South ChinaACTA ZOOLOGICA, Issue 4 2007Jianni Liu Abstract Magadictyon haikouensis (Luo and Hu, 1999) from the Early Cambrian Chengjiang Lagerstätte, an incomplete specimen of a large lobopod with strong appendages, has been regarded as related to the lobopods Microdictyon and Onychodictyon. Newly discovered complete specimens of Magadictyon cf. haikouensis (found by the Early Life Institute field team) show that the taxon, in addition to its strong appendages with appendicules, also had a head bearing similar caecum-like structures to those of the arthropod Naraoia and Chelicerate, ,Peytoia'-like mouthparts and frontal appendages. Because of their similarity, the caecum-like structures of Magadictyon cf. haikouensis are considered to be homologous with those of stem-group arthropods. The ,Peytoia'-like mouthparts and the frontal appendages are similar to those of the AOPK (Anomalocaris,Opabinia,Pambdelurion,Kerygmachela) group. In addition, the appendages with appendicules show that Magadictyon cf. haikouensis is closely related to Onychodictyon. Therefore, Magadictyon cf. haikouensis is regarded here as a rare transitional form between lobopods and arthropods. Besides, together with other lobopods, the morphology of Magadictyon cf. haikouensis demonstrates that the Cambrian lobopods appear to have been diverse and not particularly closely related to one another, and do not seem to represent a monophyletic clade. [source] Numerical and dietary responses of a predator community in a temperate zone of EuropeECOGRAPHY, Issue 2 2009Gilles Dupuy The generalist predation hypothesis predicts that the functional responses of generalist predator species should be quicker than those of specialist predators and have a regulating effect on vole populations. New interpretations of their role in temperate ecosystems have, however, reactivated a debate suggesting generalist predators may have a destabilizing effect under certain conditions (e.g. landscape homogeneity, low prey diversity, temporary dominance of 1 prey species associated with a high degree of dietary specialization). We studied a rich predator community dominated by generalist carnivores (Martes spp., Vulpes vulpes, Felis catus) over a 6 yr period in farmland and woodland in France. The most frequent prey were small rodents (mostly Microtus arvalis, a grassland species, and Apodemus spp., a woodland species). Alternative prey were diverse and dominated by lagomorphs (Oryctolagus cuniculus, Lepus europeus). We detected a numerical response among specialist carnivores but not among generalist predators. The dietary responses of generalist predators were fairly complex and most often dependent on variation in density of at least 1 prey species. These results support the generalist predation hypothesis. We document a switch to alternative prey, an increase of diet diversity, and a decrease of diet overlap between small and medium-sized generalists during the low density phase of M. arvalis. In this ecosystem, the high density phases of small mammal species are synchronous and cause a temporary specializing of several generalist predator species. This rapid functional response may indicate the predominant role of generalists in low amplitude population cycles of voles observed in some temperate areas. [source] Effects of Acer platanoides invasion on understory plant communities and tree regeneration in the northern Rocky MountainsECOGRAPHY, Issue 5 2005Kurt O. Reinhart Quantitative studies are necessary to determine whether invasive plant species displace natives and reduce local biodiversity, or if they increase local biodiversity. Here we describe the effects of invasion by Norway maple Acer platanoides on riparian plant communities and tree regeneration at two different scales (individual tree vs stand scales) in western Montana, USA, using both descriptive and experimental approaches. The three stands differed in community composition with the stand most dominated by A. platanoides invasion being more compositionally homogenous, and less species rich (,67%), species even (,40%), and diverse (,75%) than the two other stands. This sharp decrease in community richness and diversity of the highly invaded stand, relative to the other stands, corresponded with a 28-fold increase in A. platanoides seedlings and saplings. The dramatic difference between stand 1 vs 2 and 3 suggests that A. platanoides invasion is associated with a dramatic change in community composition and local loss of species diversity; however, other unaccounted for differences between stands may be the cause. These whole-stand correlations were corroborated by community patterns under individual A. platanoides trees in a stand with intermediate levels of patchy invasion. At the scale of individual A. platanoides canopies within a matrix of native trees, diversity and richness of species beneath solitary A. platanoides trees declined as the size of the trees increased. These decreases in native community properties corresponded with an increase in the density of A. platanoides seedlings. The effect of A. platanoides at the stand scale was more dramatic than at the individual canopy scale; however, at this smaller scale we only collected data from the stand with intermediate levels of invasion and not from the stand with high levels of invasion. Transplant experiments with tree seedlings demonstrated that A. platanoides seedlings performed better when grown beneath conspecific canopies than under natives, but Populus and Pinus seedlings performed better when grown beneath Populus canopies, the dominant native. Our results indicate that A. platanoides trees suppress most native species, including the regeneration of the natural canopy dominants, but facilitate conspecifics in their understories. [source] Size-dependent species-area relationships in benthos: is the world more diverse for microbes?ECOGRAPHY, Issue 3 2002Andrey I. Azovsky Using original and literature data on species richness, I compared the species-area relations for 5 different size classes of the Arctic benthos: macrofauna sensu lato, polychaetes, nematodes, ciliates and diatom algae. The data pool covered a wide range of areas from single samples to the whole seas. Both the slopes and intercepts of the curves depended significantly on the logarithm of the mean body size of the group. The number of small species (ciliates and diatom algae) showed relatively higher local diversity but increased more slowly with the area than the number of larger ones. Thus, both ,- and ,-components of species diversity of the marine benthos were size-dependent. As a consequence, the actual relations between number of species and their physical size are spatially scale-dependent: there are many more species of smaller size classes in any one local community, but at a global scope the situation changes drastically. The possible reasons are discussed, including dispersal efficiency, rates of speciation and size-dependent perception of environmental heterogeneity. Body size is suggested to be the important scaling factor in manifestation of so-called "general ecological laws". [source] | |||||||||||||||||||||||||||||||||||||||||||||||||