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1.
Sci Rep ; 9(1): 8573, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31189927

RESUMEN

The increasing trend of large carnivore attacks on humans not only raises human safety concerns but may also undermine large carnivore conservation efforts. Although rare, attacks by brown bears Ursus arctos are also on the rise and, although several studies have addressed this issue at local scales, information is lacking on a worldwide scale. Here, we investigated brown bear attacks (n = 664) on humans between 2000 and 2015 across most of the range inhabited by the species: North America (n = 183), Europe (n = 291), and East (n = 190). When the attacks occurred, half of the people were engaged in leisure activities and the main scenario was an encounter with a female with cubs. Attacks have increased significantly over time and were more frequent at high bear and low human population densities. There was no significant difference in the number of attacks between continents or between countries with different hunting practices. Understanding global patterns of bear attacks can help reduce dangerous encounters and, consequently, is crucial for informing wildlife managers and the public about appropriate measures to reduce this kind of conflicts in bear country.


Asunto(s)
Animales Salvajes/fisiología , Conservación de los Recursos Naturales , Ursidae/fisiología , Animales , Femenino , Humanos , Masculino
2.
Mol Ecol ; 19(18): 3938-51, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20735733

RESUMEN

Genetic monitoring has rarely been used for wildlife translocations despite the potential benefits this approach offers, compared to traditional field-based methods. We applied genetic monitoring to the reintroduced brown bear population in northern Italy. From 2002 to 2008, 2781 hair and faecal samples collected noninvasively plus 12 samples obtained from captured or dead bears were used to follow the demographic and geographical expansion and changes in genetic composition. Individual genotypes were used to reconstruct the wild pedigree and revealed that the population increased rapidly, from nine founders to >27 individuals in 2008 (lambda=1.17-1.19). Spatial mapping of bear samples indicated that most bears were distributed in the region surrounding the translocation site; however, individual bears were found up to 163 km away. Genetic diversity in the population was high, with expected heterozygosity of 0.74-0.79 and allelic richness of 4.55-5.41. However, multi-year genetic monitoring data showed that mortality rates were elevated, immigration did not occur, one dominant male sired all cubs born from 2002 to 2005, genetic diversity declined, relatedness increased, inbreeding occurred, and the effective population size was extremely small (Ne=3.03, ecological method). The comprehensive information collected through genetic monitoring is critical for implementing future conservation plans for the brown bear population in the Italian Alps. This study provides a model for other reintroduction programmes by demonstrating how genetic monitoring can be implemented to uncover aspects of the demography, ecology and genetics of small and reintroduced populations that will advance our understanding of the processes influencing their viability, evolution, and successful restoration.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Genética de Población , Ursidae/genética , Animales , Femenino , Variación Genética , Genotipo , Endogamia , Italia , Masculino , Repeticiones de Microsatélite , Densidad de Población
3.
Protein Sci ; 10(9): 1811-21, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11514672

RESUMEN

Arginine-140 and isoleucine-141 were identified as key determinants of 17beta-estradiol (E(2)) binding affinity of the sex-steroid-binding protein (SBP, or SHBG) of human plasma. Amino acid residues that differ between human and rabbit SBP sequences were replaced in the human protein and the products tested for lowered E(2)binding activity as are seen in the rabbit protein. Only mutants containing either R140K or I141L replacements display an E(2) equilibrium dissociation constant (Kd) higher than the wild type, reaching a value of 30 nM when both were present. The 5alpha-dihydrotestosterone (DHT) equilibrium dissociation constant of these mutants was unaffected. The quadruple mutant M107I/I138V/R140K/I141L yielded an E(2) Kd of 65 nM, significantly closer to the 80 nM rabbit SBP E(2) Kd value. Although mutants containing the M107I and I138V replacements in the absence of R140K and I141L had normal E(2) Kds, the presence of the M107I replacement in the quadruple mutant was necessary to obtain an accurate E(2) Kd value by competitive Scatchard analysis. Molecular modeling using coordinates for the recently determined N-terminal domain of human SBP revealed a significant shift of the F56 phenyl ring away from ring A of E(2) in mutant models containing the R140K and I141L replacements. We conclude that R140 and I141 are required for sustaining the right proximity of the phenyl ring of F56 to ring A of 17beta-estradiol, thus optimizing the E(2)-binding affinity of human SBP.


Asunto(s)
Arginina/metabolismo , Estradiol/metabolismo , Isoleucina/metabolismo , Globulina de Unión a Hormona Sexual/química , Globulina de Unión a Hormona Sexual/metabolismo , Secuencia de Aminoácidos , Animales , Arginina/genética , Sitios de Unión , Humanos , Isoleucina/genética , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación , Unión Proteica , Isoformas de Proteínas , Conejos , Homología de Secuencia de Aminoácido , Globulina de Unión a Hormona Sexual/genética , Especificidad por Sustrato , Termodinámica
4.
Physiol Behav ; 15(5): 455-60, 1975 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3815

RESUMEN

Earlier attempts to classically condition sea anemones have yielded inconclusive results. Using light as CS and shock as US, conditioning as distinguished from sensitization and pseudoconditioning was demonstrated in anemones. Procedural controls included substitution of light alone, shock alone, and random light and shock in place of paired light-shock trials. Responses measured were electrical output and folding of the oral disc. The conditioned response was distinguished from the unconditioned response to light and the unconditioned response to shock in terms of response latency of both electrical and behavioral measures.


Asunto(s)
Cnidarios/fisiología , Condicionamiento Clásico/fisiología , Anémonas de Mar/fisiología , Extinción Psicológica , Habituación Psicofisiológica , Luz , Dolor , Tiempo de Reacción
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