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Second Site (second + site)
Selected AbstractsBiological Sustainability of Live Shearing of Vicuña in PeruCONSERVATION BIOLOGY, Issue 1 2007CATHERINE TERESA SAHLEY Andes; conservación basada en comunidades; Vicugna vicugna Abstract:,The vicuña's (Vicugna vicugna) fiber is highly valued as an export product that is made into luxury fabric and clothing. The price of fiber in 2004 was $566/kg, which makes the fiber a potentially important source of income for Andean agropastoral communities and serves as an incentive to allow vicuña grazing on high-elevation Andean landscapes. It is presumed that a shorn vicuña has little value for poachers, so shearing vicuñas could serve as a disincentive to poaching. Thus, the supply of vicuña fiber may be sustainable if it is procured through live shearing, which should serve as a powerful conservation tool. We evaluated the effects of capture and shearing on the demography of vicuña in one site located in the Salinas Aguada Blanca Reserve, Arequipa, Peru, where vicuñas were captured and shorn in spring and then returned to the wild. We conducted fixed-width line-transect censuses from 1997 to 2003 of this population. We compared the proportion of young born to females that were shorn versus females that were unshorn for the 3 years in which shearing occurred. We evaluated the effect of capture and shearing on proportion of young born to shorn and unshorn females at a second site, Picotani, Puno. The wild population in Arequipa that underwent capture and shearing showed a steady increase in total population and average density between 1997 and 2003. No significant difference was found between the proportion of young per female for shorn and unshorn females at either site. We conclude that in spring, capture and live shearing of vicuñas can be biologically sustainable. Further research is needed to determine whether shearing during winter months is biologically sustainable. Resumen:,La fibra de vicuña (Vicugna vicugna) tiene gran valor como un producto de exportación que es transformado en tela y ropa de lujo. El precio de la fibra en 2004 era de $566/kg, lo que hace que la fibra sea una fuente de ingreso potencialmente importante para comunidades agropastoriles Andinas y servir como un incentivo para permitir el pastoreo de vicuñas en paisajes Andinos elevados. Se presume que una vicuña trasquilada tiene poco valor para cazadores furtivos, por lo que el trasquilado de vicuñas pudiera servir como un desincentivo para la caza furtiva. Por lo tanto, el abastecimiento de fibra de vicuña puede ser sustentable si se obtiene del trasquilado de animales vivos, y el trasquilado de animales vivos debería ser una poderosa herramienta de conservación. Evaluamos los efectos de la captura y trasquilado sobre la demografía de vicuñas en un sitio localizado en la Reserva Salinas Aguada Blanca, Arequipa, Perú, donde las vicuñas fueron capturadas y trasquiladas en primavera y liberadas. Realizamos censos de esta población en transectos lineales de ancho fijo de 1997 a 2003. Comparamos la proporción de crías de hembras trasquiladas con las de hembras no trasquiladas durante los 3 años en que ocurrió el trasquilado. Evaluamos el efecto de la captura y trasquilado sobre la proporción de crías de hembras trasquiladas y no trasquiladas en un segundo sitio, Picotani, Puno. La población silvestre en Arequipa que fue capturada y trasquilada mostró un incremento constante en la población total y la densidad promedio entre 1997 y 2003. No se encontró diferencia significativa entre la proporción de crías por hembra para hembras trasquiladas y no trasquiladas en ningún sitio. Concluimos que en la primavera, la captura y trasquilado de vicuñas vivas puede ser biológicamente sostenible. Se requiere más investigación para determinar si el trasquilado durante el invierno es biológicamente sostenible. [source] Synthesis, X-ray Crystal Structures and Electrochemistry of (Indenyl)ruthenium Complexes Containing dppf and Heterocyclic Thiolato/Thione LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2008Sin Yee Ng Abstract A number of (indenyl)ruthenium complexes containing dppf [1,1,-bis(diphenylphosphanyl)ferrocene] and heterocyclic thiolato/thione ligands have been synthesized. All the complexes were fully characterized by microanalytical and spectroscopic techniques, together with X-ray diffraction analyses for those containing the benzothiazolato (thiolato) and the thiadiazole (thione) ligands. Cyclic voltammetry (CV) experiments indicated that these complexes can be oxidized in three one-electron processes at positive potentials. Differences in chemical reversibility observed during variable-temperature CV experiments indicated that it was likely that the oxidation processes occurred at two electronically noncommunicating sites within the molecules. One site could be assigned as the oxidation of the Ru ion (two one-electron processes), whilst the second site was assigned as the oxidation of the dppf (one one-electron process). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Escherichia coli thioredoxin inhibition by cadmiumFEBS JOURNAL, Issue 7 2004Asp2, Two mutually exclusive binding sites involving Cys3 Observations of thioredoxin inhibition by cadmium and of a positive role for thioredoxin in protection from Cd2+ led us to investigate the thioredoxin,cadmium interaction properties. We used calorimetric and spectroscopic methods at different pH values to explore the relative contribution of putative binding residues (Cys32, Cys35, Trp28, Trp31 and Asp26) within or near the active site. At pH 8 or 7.5 two binding sites were identified by isothermal titration calorimetry with affinity constants of 10 × 106 m,1 and 1 × 106 m,1. For both sites, a proton was released upon Cd2+ binding. One mole of Cd2+ per mole of reduced thioredoxin was measured by mass spectrometry at these pH values, demonstrating that the two binding sites were partially occupied and mutually exclusive. Cd2+ binding at either site totally inhibited the thiol,disulfide transferase activity of Trx. The absence of Cd2+ interaction detected for oxidized or alkylated Trx and the inhibition of the enzymatic activity of thioredoxin by Cd2+ supported the role of Cys32 at the first site. The fluorescence profile of Cd2+ -bound thioredoxin differed, however, from that of oxidized thioredoxin, indicating that Cd2+ was not coordinated with Cys32 and Cys35. From FTIR spectroscopy, we inferred that the second site might involve Asp26, a buried residue that deprotonates at a rather high and unusual pKa for a carboxylate (7.5/9.2). The pKa of the two residues Cys32 and Asp26 have been shown to be interdependent [Chivers, T. P. (1997) Biochemistry36, 14985,14991]. A mechanism is proposed in which Cd2+ binding at the solvent-accessible thiolate group of Cys32 induces a decrease of the pKa of Asp26 and its deprotonation. Conversely, interaction between the carboxylate group of Asp26 and Cd2+ at a second binding site induces Cys32 deprotonation and thioredoxin inhibition, so that Cd2+ inhibits thioredoxin activity not only by binding at the Cys32 but also by interacting with Asp26. [source] More Difficult to Believe?INTERNATIONAL JOURNAL OF SYSTEMATIC THEOLOGY, Issue 1 2001Luther on Divine Omnipotence This article considers Luther's statement in thesis 21 of the 1545 doctoral disputation of Petrus Hegemon (1545) concerning the difficulty of belief in creatio ex nihilo, and suggests that this difficulty shapes the later Luther's theology in significant ways. The difficulty is reconstructed as a gradual movement into the mystery of the creatio ex nihilo. The first site of difficulty correlates the knowledge of creatures as particulars with the knowledge of the Creator as the source of existence. The move towards a second site is propelled by the question of inevitable death, which Luther answers by moving from material and natural generation to the resurrection and then to the creatio ex nihilo. At the third site, Luther addresses such disturbing questions as the suffering of the righteous, the historical cycle of political power, and the harshness of reprobation. He answers these questions by integrating the symmetrical biblical statements of the annihilatio and the creatio with a theological theory of divine omnipotence. God's hiddenness is understood as God's omnipotence working at the specific locations of self-negation, as well as behind the ebb and flow of historical-political contingency. Faith presses into the hidden mystery, grounded in the certainty that all things are effected by the Creator whose nature is self-giving goodness, and established by the hope that the light of glory will determine more fully the God who is to be honored above all. [source] Modulation of integrin antagonist signaling by ligand binding of the heparin-binding domain of vitronectin to the ,V,3 integrinJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Laura A. Maile Abstract The interaction between the arginine glycine and aspartic acid motif (RGD) of integrin ligands such as vitronectin and the integrin receptor ,V,3 in mediating cell attachment has been well described. Similarly, the ability of disintegrins, small RGD containing peptides, to inhibit cell attachment and other cellular processes has also been studied extensively. Recently, we characterized a second site of interaction between vitronectin and its integrin partner. We determined that amino acids within the heparin-binding domain of vitronectin bind to a cysteine loop (C-loop) region of ,3 and that this interaction is required for the positive effects of ,V,3 ligand occupancy on IGF-I signaling in smooth muscle cells. In this study we examine the signaling events activated following ligand binding of disintegrins to the ,V,3 and the ability of these signals to be regulated by binding of the heparin-binding domain of vitronectin. We demonstrate that disintegrin ligand binding activates a series of events including the sequential activation of the tyrosine kinases c-Src and Syk. This leads to the activation of calpain and the cleavage of the ,3 cytoplasmic tail. Addition of vitronectin or a peptide homologous to the heparin-binding domain inhibited activation of this pathway. Our results suggest that the signaling events that occur following ligand binding to the ,V,3 integrin reflects a balance between the effects mediated through the RGD binding site interaction and the effects mediated by the heparin binding site interaction and that for intact vitronectin the effect of the heparin-binding domain predominates. J. Cell. Biochem. 105: 437,446, 2008. © 2008 Wiley-Liss, Inc. [source] SEASONAL GROWTH AND PHENOTYPIC VARIATION IN PORPHYRA LINEARIS (RHODOPHYTA) POPULATIONS ON THE WEST COAST OF IRELAND,JOURNAL OF PHYCOLOGY, Issue 1 2007Elena Varela-Álvarez The phenology and seasonal growth of Porphyra linearis Grev. were investigated in two morphologically dissimilar populations from the west coast of Ireland. Thallus size and reproductive status of individuals were monitored monthly between June 1997 and June 1998. Both populations exhibited a similar phenology: gametophyte stages appeared on the shore in October, with spermatangial and zygotosporangial sori appearing the following February; the gametophyte stage began to degenerate in April and had disappeared completely by June. However, significant differences in growth and reproduction in the field and in cultures of plants from the two populations were observed. Thallus length and width of individuals from one population were significantly longer throughout the sample period, and reproduction and sporulation occurred 1 month earlier. Also, in situ relative growth rates (RGRs) of plants differed significantly and were correlated with different climatic factors (sunshine, day length, irradiance, rainfall, seawater temperature, and intertidal temperatures), suggesting that plants were affected by two different microhabitats. At one site, blades were more exposed to wave action, sunshine, and extreme minimum temperatures, while at the other site, blades were more protected in winter, spring, and early summer. In culture, RGRs of blades from the second site were higher than RGRs of blades from the first site under short days, corroborating the field results and suggesting a degree of phenotypic differentiation between the two populations. However, there were no sequence divergences of the RUBISCO spacer between strains of the two P. linearis populations. [source] Kinetic behavior of ethylene/1-hexene copolymerization in slurry and solution reactorsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2005Long Wu Abstract The copolymerization of ethylene and 1-hexene over a spherical polymer/MgCl2 -supported TiCl4 catalyst was studied as a function of the polymerization temperature from 40 to 100 °C in a slurry reactor and from 120 to 200 °C in a solution reactor with triethylaluminum (TEA) as a cocatalyst (1.0,6.8 mmol). The activities increased from 40 to 80 °C and then declined monotonically with increases in the temperature during the slurry and solution polymerizations. The kinetic behavior in the slurry and solution operations was described by the same rate expression. The modeling results indicated that the catalyst had at least two different types of catalytic sites; one site was responsible for the acceleration,decay nature of the activity profiles, whereas the second site resulted in long-term activity. The apparent activation energy for site activation in the slurry operation was 69.9 kJ/mol; no activation energies for site activation could be estimated for the solution operation because the activation process was essentially instantaneous at the higher temperatures. The activation energies for deactivation were 100.3 kJ/mol for the slurry operation and 31.2 kJ/mol for the solution operation. The responses to TEA were similar for the slurry and solution operations; the rates increased with increasing amounts of TEA between 1.0 and 3.4 mmol and then decreased with larger amounts of TEA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2248,2257, 2005 [source] Mapping and characterization of B cell linear epitopes in the conservative regions of hepatitis C virus envelope glycoproteinsJOURNAL OF VIRAL HEPATITIS, Issue 3 2002L. V. Olenina Forty-eight overlapping octapeptides covering highly conservative regions of E1 and E2 hepatitis C virus (HCV) envelope proteins were synthesized and tested by ELISA against different groups of sera obtained from HCV-infected patients. All sera from patients with acute infection, except a single case of serum reactivity with the region HINRTALN, were nonreactive with any peptide. Sera obtained from chronic patients reacted with 12 peptides from five selected regions. Two immunodominant B epitopes were found, one being the precisely mapped antigenic site RMAWDM positioned inside the earlier shown immunodominant epitope from E1, and the second site, PALSTGLIH from E2, detected for the first time. New minor antigenic site was determined as PTDCFRKH from E2. We found only minor seroreactivity for one of the putative sites involved in CD81 binding, PYCWHYAP. [source] Consistency of a two clinical site sample collection: A proteomics studyPROTEOMICS - CLINICAL APPLICATIONS, Issue 8-9 2010Cedric Wiesner Abstract Purpose: We investigated the ability to perform a clinical proteomic study using samples collected at different times from two independent clinical sites. Experimental Design: Label-free 2-D-LC-MS proteomic analysis was used to differentially quantify tens of thousands of peptides from human plasma. We have asked whether samples collected from two sites, when analyzed by this type of peptide profiling, reproducibly contain detectable peptide markers that are differentially expressed in the plasma of disease (advanced renal cancer) patients relative to healthy normals. Results: We have demonstrated that plasma proteins enriched in disease patients are indeed detected reproducibly in both clinical collections. Regression analysis, unsupervised hierarchical clustering and PCA detected no systematic bias in the data related to site of sample collection and processing. Using a genetic algorithm, support vector machine classification method, we were able to correctly classify disease samples at 88% sensitivity and 94% specificity using the second site as an independent validation set. Conclusions and clinical relevance: We conclude that multiple site collection, when analyzed by label-free 2-D-LC-MS, generates data that are sufficiently reproducible to guide reliable biomarker discovery. [source] Structural characterization of YV4O8: simultaneous analysis of coexisting polytypes and simulation of diffuse scattering for a stacking disorder modelACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2003Mitsuko Onoda The structure of a crystal of newly synthesized YV4O8 was refined on the assumption that two polytypes and their respective twin forms intergrow. The model was expressed as a commensurate composite crystal with two types of subsystem: one is a V4O8 framework with rather large tunnels and the other consists of Y ions. In the tunnels, Y ions and vacancies are located at every second site in an ordered manner that is characteristic of each polytype. Refinement was performed using a high-dimensional formalism and all reflections from all domains. Diffuse streaks observed in the X-ray and electron diffraction patterns were simulated using the matrix method that has been used for one-dimensional disorder such as stacking faults. The unusual diffraction phenomena that occur in a crystal of YV4O8 are explained as arising from a multiple-domain structure of coexisting polytypes. [source] X-ray structure of the metcyano form of dehaloperoxidase from Amphitrite ornata: evidence for photoreductive dissociation of the iron,cyanide bondACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2010V. S. De Serrano X-ray crystal structures of the metcyano form of dehaloperoxidase-hemoglobin (DHP A) from Amphitrite ornata (DHPCN) and the C73S mutant of DHP A (C73SCN) were determined using synchrotron radiation in order to further investigate the geometry of diatomic ligands coordinated to the heme iron. The DHPCN structure was also determined using a rotating-anode source. The structures show evidence of photoreduction of the iron accompanied by dissociation of bound cyanide ion (CN,) that depend on the intensity of the X-ray radiation and the exposure time. The electron density is consistent with diatomic molecules located in two sites in the distal pocket of DHPCN. However, the identities of the diatomic ligands at these two sites are not uniquely determined by the electron-density map. Consequently, density functional theory calculations were conducted in order to determine whether the bond lengths, angles and dissociation energies are consistent with bound CN, or O2 in the iron-bound site. In addition, molecular-dynamics simulations were carried out in order to determine whether the dynamics are consistent with trapped CN, or O2 in the second site of the distal pocket. Based on these calculations and comparison with a previously determined X-ray crystal structure of the C73S,O2 form of DHP [de Serrano et al. (2007), Acta Cryst. D63, 1094,1101], it is concluded that CN, is gradually replaced by O2 as crystalline DHP is photoreduced at 100,K. The ease of photoreduction of DHP A is consistent with the reduction potential, but suggests an alternative activation mechanism for DHP A compared with other peroxidases, which typically have reduction potentials that are 0.5,V more negative. The lability of CN, at 100,K suggests that the distal pocket of DHP A has greater flexibility than most other hemoglobins. [source] | |||||||||||||