Underlying and proximate drivers of biodiversity changes in Mesoamerican biosphere reserves.

Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas' effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a "winner and loser" species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative.

Changes in landscape and climate in Mexico and Texas reveal small effects on migratory habitat of monarch butterflies (Danaus plexippus).

The decline of the iconic monarch butterfly (Danaus plexippus) in North America has motivated research on the impacts of land use and land cover (LULC) change and climate variability on monarch habitat and population dynamics. We investigated spring and fall trends in LULC, milkweed and nectar resources over a 20-year period, and ~ 30 years of climate variables in Mexico and Texas, U.S. This region supports spring breeding, and spring and fall migration during the annual life cycle of the monarch. We estimated a - 2.9% decline in milkweed in Texas, but little to no change in Mexico. Fall and spring nectar resources declined < 1% in both study extents. Vegetation greenness increased in the fall and spring in Mexico while the other climate variables did not change in both Mexico and Texas. Monarch habitat in Mexico and Texas appears relatively more intact than in the midwestern, agricultural landscapes of the U.S. Given the relatively modest observed changes in nectar and milkweed, the relatively stable climate conditions, and increased vegetation greenness in Mexico, it seems unlikely that habitat loss (quantity or quality) in Mexico and Texas has caused large declines in population size or survival during migration.

Classification and distribution of functional groups of birds and mammals in Mexico.

There has been a recent exponential growth in the study of functional trait ecology. Nonetheless, the study of functional traits and functional groups has been limited for terrestrial vertebrates. We conducted a classification update of functional groups (FG) of birds and mammals in Mexico, and determined the distribution patterns of FG species richness in different ecosystems nationwide. We selected six functional traits (feeding habit, locomotion, feeding substrate and technique, activity period, seasonality, and body size) obtained for 987 and 496 species of birds and mammals, respectively. A cophenetic correlation analyses resulted in values of 0.82 for the bird species dendrogram, and 0.79 for the mammal species dendrogram showing that the structures adequately reflected the similarity between observations. We obtained 52 FG for birds, assembled into 9 broader groups based on their feeding habits (16 invertivores, 6 carnivores: 5 herbivores, 9 aquatic vertivore/invertivore, 5 granivores, 1 scavenger, 3 nectarivores, 4 frugivores, and 3 omnivores). We obtained 35 FG for mammals, assembled into 9 broader groups based on their feeding habits (4 granivores, 10 herbivores, 1 nectarivore, 4 frugivores, 8 invertivores, 3 omnivores, 2 aquatic vertivore/invertivore, 1 hematophagous, and 2 carnivores). Overall, the distribution of FG species richness for birds and mammals gradually increased from the Nearctic to the Neotropical region, following a typical latitudinal species richness pattern. Few FG of migratory birds, and FG of granivore and herbivore mammals showed more species in the Nearctic and in the transitional regions. Our study provides a baseline for identifying ecological functions of species of birds and mammals in different ecosystems in Mexico, and contributes to understand the relationship between species diversity, community structure and ecosystem functioning. Identifying spatial patterns of functional trait diversity is important as biodiversity loss has a negative impact on ecosystem functioning and provision of environmental services.

Modelling the Unidentified Abortion Burden from Four Infectious Pathogenic Microorganisms (Leptospira interrogans, Brucella abortus, Brucella ovis, and Chlamydia abortus) in Ewes Based on Artificial Neural Networks Approach: The Epidemiological Basis for a Control Policy.

Unidentified abortion, of which leptospirosis, brucellosis, and ovine enzootic abortion are important factors, is the main cause of disease spread between animals and humans in all agricultural systems in most developing countries. Although there are well-defined risk factors for these diseases, these characteristics do not represent the prevalence of the disease in different regions. This study predicts the unidentified abortion burden from multi-microorganisms in ewes based on an artificial neural networks approach and the GLM. METHODS: A two-stage cluster survey design was conducted to estimate the seroprevalence of abortifacient microorganisms and to identify putative factors of infectious abortion. RESULTS: The overall seroprevalence of Brucella was 70.7%, while Leptospira spp. was 55.2%, C. abortus was 21.9%, and B. ovis was 7.4%. Serological detection with four abortion-causing microorganisms was determined only in 0.87% of sheep sampled. The best GLM is integrated via serological detection of serovar Hardjo and Brucella ovis in animals of the slopes with elevation between 2600 and 2800 meters above sea level from the municipality of Xalatlaco. Other covariates included in the GLM, such as the sheep pen built with materials of metal grids and untreated wood, dirt and concrete floors, bed of straw, and the well water supply were also remained independently associated with infectious abortion. Approximately 80% of those respondents did not wear gloves or masks to prevent the transmission of the abortifacient zoonotic microorganisms. CONCLUSIONS: Sensitizing stakeholders on good agricultural practices could improve public health surveillance. Further studies on the effect of animal-human transmission in such a setting is worthwhile to further support the One Health initiative.

Effect of the microstructure on the propagation velocity of ultrasound in magnetic powders.

We analyze experimentally and theoretically the sound propagation velocity of P-waves in granular media made of micrometer-size magnetite particles under an external magnetic field. The sound velocity is measured in a coherent (long-wavelength) regime of propagation after a controlled sample preparation consisting of a fluidization and the application of a magnetic field. Several different procedures are applied and result in different but reproducible particle arrangements and preferential contact orientations affecting the measured sound velocity. Interestingly, we find that the sound velocity increases when the magnetic field is applied parallel to the sound propagation direction and decreases when the magnetic field is applied perpendicular to the sound propagation direction. The observed qualitative relationship between the changes in the particle arrangement and the sound velocity is analyzed theoretically based on an effective medium theory adapted to account for the effect of the magnetic field in the preparation procedure and its influence on the medium contact fabric.

Jaguar conservation in the American continent: the role of protected landscape and human-impacted biomes

Introduction: Worldwide, expanding human activities continue to be a threat to many large-bodied species, including jaguars. As these activities continue, it is critical to understand how home range sizes will be impacted by human-modified landscapes. Objective: To evaluate the importance of protected and unprotected land on home-range size across their range. Methods: We used home range data from 117 jaguars in several habitat protection categories and human biome types. We used a Generalized Linear Mixed Model to test home range and spatial overlap with conservation categories and human biomes. Results: Most home-ranges were in Jaguar Conservation Units (62 %), followed by Protected Areas (21 %), Indigenous People's Lands (10 %) and Jaguar Movement Corridors (3 %), where 76 % of the jaguars lived inside one the first three conservation types. However, outside of conserved land, Rangeland, Cropland, Seminatural land and other human biomes were also important (24 % of the individuals). Jaguars in Rangeland, Cropland and Seminatural land had the largest home ranges. Conclusions: Although conservation land was dominant, human-impacted lands appear to play a considerable role in satisfying the spatial requirements of jaguars.

Introducción: A nivel mundial, la expansión de actividades humanas continúa teniendo un riesgo para muchas especies de cuerpo grande, tal como los jaguares. Conforme continúen estas actividades, es crucial entender el impacto de paisajes modificados sobre el tamaño de su territorio. Objetivo: Evaluar la importancia de terrenos protegidos y no protegidos sobre el tamaño de su territorio a lo largo de su rango. Métodos: Usamos datos de tamaño de los territorios de 117 jaguares en varias categorías de protección de hábitats y biomas humanos. Usamos un Modelo Mixto Lineal Generalizado para probar traslapes espaciales y de territorios con categorías de conservación y biomas humanos. Resultados: La mayoría de los territorios estaban en Unidades de Conservación de Jaguares (62 %), seguido por Áreas protegidas (21 %), Tierras de Pueblos Indígenas (10 %) y Corredores de Movimiento de Jaguares (3 %), en donde el 76 % de los jaguares vivían dentro de alguna de las primeras tres modalidades de conservación. Sin embargo, fuera de áreas protegidas, pastizales, tierras de cultivo, terrenos seminaturales y otros biomas humanos también fueron importantes (24 % de individuos). Jaguares en pastizales, tierras de cultivo, y terrenos seminaturales tuvieron territorios más grandes. Conclusiones: Aunque las áreas de conservación fueron dominantes, áreas con impacto humano parecieron jugar un rol considerable en satisfacer los requerimientos espaciales de los jaguares.

[Assessment of antibiotic use and impact of an intervention intended to modify the prescribing behavior in surgical prophylaxis in 6hospitals in the metropolitan area of Monterrey, Mexico]. / Evaluación del uso de antibióticos e impacto de una intervención dirigida a modificar la conducta prescriptiva en profilaxis quirúrgica en 6hospitales del área metropolitana de Monterrey.

BACKGROUND: Improper use of antibiotics increases antimicrobial resistance. OBJECTIVE: Evaluate the use of antibiotics and the impact of an intervention designed to improve antibiotic prescription for surgical prophylaxis in 6 hospitals of Monterrey, Mexico. MATERIAL AND METHODS: Design: A prospective multicenter survey and a pretest-postest experimental study. Phase 1: Survey to evaluate the use of antibiotics through an especially designed guide. Phase 2: Intervention designed to improve antibiotic prescription for surgical prophylaxis by the medical staff by using printed, audiovisual and electronic messages. Phase 3: Survey to evaluate the impact of the intervention. ANALYSIS: Frequencies, percentages, medians, ranges and X2 test. RESULTS: Phase 1: We evaluated 358 surgical patients, 274 prophylactic antibiotic regimens. A total of 96% of antibiotics regimens began with inappropriate timing (290/302), 82.8% were inappropriate regimens (274/331), 77.7% were in inappropriate dosage (230/296), 86% of inadequate length (241/280), and in 17.4% restricted antibiotics were used (52/299). Phase 2: 9 sessions including 189 physicians (14 department chairs, 58 general practitioners and 117 residents). Phase 3: We evaluated 303 surgical patients, 218 prophylactic antibiotics regimens. Inappropriate treatment commencement was reduced to 84.1% (180/214) (P<0.001), inappropriate regimens to 75.3% (162/215) (P=0.03), inappropriate dosages to 51.2% (110/215) (P<0.001), and use of restricted antibiotics to 8.3% (18/215) (P=0.003). CONCLUSIONS: Inappropriate use of prophylactic antibiotics in surgery is a frequent problem in Monterrey. The intervention improved the antibiotic prescription for surgical prophylaxis by reducing inappropriate treatment commencement, regimens, dosages, and overuse of restricted antibiotics. It is necessary to strengthen strategies to improve the prescription of antibiotics in surgical prophylaxis.

Ultrasonic probing of cohesive granular media at very low consolidation.

In this work, we study sound propagation in different granular media made of magnetite particles, steel particles, and glass beads consolidated under their own weight. We used two ultrasonic non invasive methods, which are found in good agreement, to estimate the longitudinal wave velocity Vp. In the first one, the velocity is determined through the resonance peaks of the powder slab. The second method determines the velocity with the time of flight of a short pulse traveling through the medium. Magnetite and steel samples show dispersive properties below a frequency ∼ 10kHz. The increase of attractive forces between particles lead to two competing effects; on one hand the solid fraction decreases and on the other hand the contacts are stiffer. A decrease in solid fraction implies that the number of contacts decreases leading to a decrease in the wave propagation velocity. On the other hand stronger contacts on average lead to an increase of sound velocity. In our experiments an increase in powder cohesion (caused by a decrease of the bead diameter) leads to an increase in sound velocity even though the solid fraction decreases. The same behavior is found in glass beads. These results show the predominant role of cohesive forces on sound propagation in loosely consolidated dry fine powders as well as the accuracy of ultrasonic methods for powder characterization.