145 research outputs found
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Conservation in conflict: Illegal drugs versus habitat in the Americas
About the book:
State of the Wild is a biennial series that brings together international conservation experts and writers to discuss emerging issues in the conservation of wildlife and wild places.
Each volume in the series combines evocative writings with a fascinating tour of conservation news highlights and vital statistics from around the world. One-third of each volume focuses on a topic of particular concern to conservationists working to protect wildlife and our last wild places. This 2008–2009 edition considers the integration of wildlife health, ecosystem health, human health, and the health of domestic animals—a “One World–One Health” approach to disease and conservation.
This focus is complemented with essays clustered into sections that address other key issues—conservation of species; conservation of wild places; people, culture, and conservation; and the art and practice of conservation. Essays cover a broad range of topics, from restoring biodiversity on the prairies to mapping the state of the oceans to the conservation impacts of lawlessness and coca cultivation in Colombia. Essay contributions come from people directly involved in on-the-ground conservation efforts and offer a unique and valuable perspective on often-overlooked topics.
State of the Wild’s accessible approach educates a wide range of audiences while at the same time presenting leading-edge scientific overviews of hot topics in conservation. Uniquely structured with magazine-like features up front, conservation news in the middle, and essays from eminent authors and experienced scientists throughout, this landmark series is an essential addition to any environmental bookshelf
Opposition Support and the Experience of Violence Explain the Colombian Peace Referendum
What factors led to the surprise defeat of the Colombian peace referendum? Descriptive analyses suggested a link between support for peace and the experience of violence, but economic conditions and political support for incumbent parties also affect electoral outcomes. Here we use Bayesian hierarchical models to test links between referendum result and previous violence victimization, economic conditions, and support for Centro Democrático (the main party opposed to the peace agreement). There was lower support for peace in the Andean region, and departments with lower support had higher unemployment and growth in GDP. Support for the opposition was the dominant covariate of decreasing support for the peace accords, while previous violence victimization increased the percent vote for peace. Regional variation in baseline support for the agreements will be critical during implementation of the newly revised accords, and the mobilization of the opposition shows partisan engagement determined the referendum outcome.¿Qué factores llevaron a la derrota sorpresiva del plebiscito por la paz en Colombia? Aunque los análisis iniciales encontraron conexiones entre el apoyo por la paz y la experiencia de violencia, las condiciones económicas y el apoyo a los partidos en el poder también afectaron tales resultados electorales. En este artículo utilizamos modelos jerárquicos bayesianos para evaluar las conexiones entre los resultados del plebiscito y la experiencia previa de victimización, las condiciones económicas, y el apoyo al Centro Democrático (el partido político opositor al acuerdo de paz principal). Hubo menos apoyo por la paz en la zona andina comparada con otras regiones, y los departamentos con menos apoyo tuvieron mayor desempleo y crecimiento del PIB. A pesar que la experiencia previa de victimización aumentó la proporción de votos por la paz, el apoyo a la oposición fue la covariante dominante en el descenso en el apoyo por los acuerdos de paz. Teniendo en cuenta estos resultados, la fuerte variación regional en la línea base de apoyo a los acuerdos - una variable compleja gobernada por el grado de compromiso político, pero también influenciada por factores económicos estructurales - será crítica en la implementación de los nuevos acuerdos
Deep MOS Spectroscopy of NGC 1316 Globular Clusters
The giant elliptical galaxy NGC 1316 is the brightest galaxy in the Fornax
cluster, and displays a number of morphological features that might be
interpreted as an intermediate age merger remanent (3 Gyr). Based on the
idea that globular clusters systems (GCS) constitute genuine tracers of the
formation and evolution of their host galaxies, we conducted a spectroscopic
study of approximately 40 globular clusters (GCs) candidates associated with
this interesting galaxy. We determined ages, metallicities, and
-element abundances for each GC present in the sample, through the
measurement of different Lick indices and their subsequent comparison with
simple stellar populations models (SSPs).Comment: 5 pages, 3 figure
Horas de éxodo y estacionalidad de los murciélagos en cuatro cuevas de República Dominicana
Se estudiaron los patrones de emergencia y estados reproductivos de las poblaciones de murciélagos en cuatro cuevas de la República Dominicana. Se capturó un total de 12 especies: Mormoops blainvillei, Pteronotus parnellii, Pteronotus quadridens, Chilonatalus micropus, Natalus major, Artibeus jamaicensis, Brachyphylla pumila, Erophylla bombifrons, Macrotus waterhousii, Monophyllus redmani, Phyllonycteris poeyi y Eptesicus fuscus. Los murciélagos se capturaron de forma más o menos continua entre las 18:15 y 23:00h. De un total de 1,445 ejemplares a los cuales se les determinó el sexo, 969 fueron machos (67.1%). Los resultados obtenidos con respecto a la actividad reproductiva muestran cómo las especies presentes en las cuevas se encuentran en estados reproductivos diferentes, registrándose ejemplares preñadas o lactantes, pertenecientes a dos familias dominantes: Mormopidae y Phyllostomidae. Además, que se contrastaron reportes de Cuba y Puerto Rico donde se muestra que algunas especies podrían tener épocas reproductivas más largas que las reportadas actualmente
Histological and MRI brain atlas of the common shrew, Sorex araneus, with brain region-specific gene expression profiles
Histological and MRI brain atlas of the common shrew, Sorex araneus, with brain region-specific gene expression profiles
The common shrew, Sorex araneus, is a small mammal of growing interest in neuroscience research, as it exhibits dramatic and reversible seasonal changes in individual brain size and organization (a process known as Dehnel’s phenomenon). Despite decades of studies on this system, the mechanisms behind the structural changes during Dehnel’s phenomenon are not yet understood. To resolve these questions and foster research on this unique species, we present the first combined histological, magnetic resonance imaging (MRI), and transcriptomic atlas of the common shrew brain. Our integrated morphometric brain atlas provides easily obtainable and comparable anatomic structures, while transcriptomic mapping identified distinct expression profiles across most brain regions. These results suggest that high-resolution morphological and genetic research is pivotal for elucidating the mechanisms underlying Dehnel’s phenomenon while providing a communal resource for continued research on a model of natural mammalian regeneration. Morphometric and NCBI Sequencing Read Archive are available at https://doi.org/10.17617/3.HVW8ZN
From the Field to the Lab: Best Practices for Field Preservation of Bat Specimens for Molecular Analyses
Studies in molecular ecology depend on field-collected samples for genetic information, and the tissue sampled and preservation conditions strongly affect the quality of the DNA obtained. DNA yields from different tissue types have seldom been compared, and the relative performance of storage media has never been directly tested, even though these media may influence DNA degradation under field conditions. We analyzed DNA yield from buccal swabs and wing punches harvested from live bats using nucleic acid quantification as well as quantitative PCR for a single-copy nuclear locus. We also compared DNA yields from wing tissue preserved in three media: ethanol, NaCl-saturated dimethyl sulfoxide (DMSO), and silica desiccant. Wing punches yielded more total DNA than did buccal swabs, and wing tissues preserved in silica beads yielded significantly more total and nuclear DNA than those preserved in DMSO or ethanol. These results show that tissue type and preservation media strongly influence the quantity of DNA obtained from non-lethal genetic samples, and based on these effects we provide recommendations for field collection of tissues for genetic analyses
Fire-induced loss of the world's most biodiverse forests in Latin America
The quantitative signal for the association of fires and land cover change is strong and the impact of frequent fires is vast. Fire plays a dominant role in deforestation, particularly in the tropics, but the relative extent of transformations and influence of fire frequency on eventual forest loss remain unclear. Here, we analyze the frequency of fire and its influence on postfire forest trajectories between 2001 and 2018. We account for ~1.1% of Latin American forests burnt in 2002-2003 (8,465,850 ha). Although 40.1% of forests (3,393,250 ha) burned only once, by 2018, ~48% of the evergreen forests converted to other, primarily grass-dominated uses. While greater fire frequency yielded more transformation, our results reveal the staggering impact of even a single fire. Increasing fire frequency imposes greater risks of irreversible forest loss, transforming forests into ecosystems increasingly vulnerable to degradation. Reversing this trend is indispensable to both mitigate and adapt to climate change globally. As climate change transforms fire regimes across the region, key actions are needed to conserve Latin American forests
The evolution of antimicrobial peptides in Chiroptera
High viral tolerance coupled with an extraordinary regulation of the immune response makes bats a great model to study host-pathogen evolution. Although many immune-related gene gains and losses have been previously reported in bats, important gene families such as antimicrobial peptides (AMPs) remain understudied. We built an exhaustive bioinformatic pipeline targeting the major gene families of defensins and cathelicidins to explore AMP diversity and analyze their evolution and distribution across six bat families. A combination of manual and automated procedures identified 29 AMP families across queried species, with α-, β-defensins, and cathelicidins representing around 10% of AMP diversity. Gene duplications were inferred in both α-defensins, which were absent in five species, and three β-defensin gene subfamilies, but cathelicidins did not show significant shifts in gene family size and were absent in Anoura caudifer and the pteropodids. Based on lineage-specific gains and losses, we propose diet and diet-related microbiome evolution may determine the evolution of α- and β-defensins gene families and subfamilies. These results highlight the importance of building species-specific libraries for genome annotation in non-model organisms and shed light on possible drivers responsible for the rapid evolution of AMPs. By focusing on these understudied defenses, we provide a robust framework for explaining bat responses to pathogens
Molecular evolution of growth hormone and insulin-like growth factor 1 receptors in long-lived, small-bodied mammals
Mammals typically display a robust positive relationship between lifespan and body size. Two groups that deviate
markedly from this pattern are bats and African mole-rats, with members of both groups being extremely
long-lived given their body size, with the maximum documented lifespan for many species exceeding
20 years. A recent genomics study of the exceptionally long-lived Brandt's bat, Myotis brandtii (41 years), suggested
that its longevity and small body size may be at least partly attributed to key amino acid substitutions
in the transmembrane domains of the receptors of growth hormone (GH) and insulin-like growth factor 1
(IGF1). However, whereas elevated longevity is likely to be common across all 19 bat families, the reported
amino acid substitutionswere only observed in two closely related bat families. To test the hypothesis that an altered
GH/IGF1 axis relates to the longevity of African mole-rats and bats,we compared and analysed the homologous
coding gene sequences in genomic and transcriptomic data from 26 bat species, five mole-rats and 38
outgroup species. Phylogenetic analyses of both genes recovered themajority of nodes in the currently accepted
species tree with high support. Compared to other clades, such as primates and carnivores, the bats and rodents
had longer branch lengths. The single 24 amino acid transmembrane domain of IGF1Rwas found to bemore conserved
across mammals compared to that of GHR.Within bats, considerable variation in the transmembrane domain
of GHR was found, including a previously unreported deletion in Emballonuridae. The transmembrane
domains of rodents were found to be more conserved, with mole-rats lacking uniquely conserved amino acid
substitutions. Molecular evolutionary analyses showed that both genes were under purifying selection in bats
andmole-rats. Our findings suggest thatwhile the previously documentedmutations may confer some additional
lifespan to Myotis bats, other, as yet unknown, genetic differences are likely to account for the long lifespans
observed in many bat and mole-rat species.DST–NRF SARChI Chair for Behavioural Ecology and Physiology (64756), the European Research Council (310482 EVOGENO) and the National Science Foundation (DEB-0949759).http//www.elsevier.com/locate/genehb201
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