Hasil untuk "America"

K. Rosenberg, A. Dokter, P. Blancher et al.

Staggering decline of bird populations Because birds are conspicuous and easy to identify and count, reliable records of their occurrence have been gathered over many decades in many parts of the world. Drawing on such data for North America, Rosenberg et al. report wide-spread population declines of birds over the past half-century, resulting in the cumulative loss of billions of breeding individuals across a wide range of species and habitats. They show that declines are not restricted to rare and threatened species—those once considered common and wide-spread are also diminished. These results have major implications for ecosystem integrity, the conservation of wildlife more broadly, and policies associated with the protection of birds and native ecosystems on which they depend. Science, this issue p. 120 The cumulative loss of nearly 3 billion birds since 1970 across North American biomes signals a continuing avifaunal crisis. Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals that can result in compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report population losses across much of the North American avifauna over 48 years, including once-common species and from most biomes. Integration of range-wide population trajectories and size estimates indicates a net loss approaching 3 billion birds, or 29% of 1970 abundance. A continent-wide weather radar network also reveals a similarly steep decline in biomass passage of migrating birds over a recent 10-year period. This loss of bird abundance signals an urgent need to address threats to avert future avifaunal collapse and associated loss of ecosystem integrity, function, and services.

S. Greenwood, Andrew T. Perrin, Maeve Duggan

Raúl Mercer, P. Salgado, C. Ocampo

Background Caesarean section (CS) rates continue to evoke worldwide concern because of their steady increase, lack of consensus on the appropriate CS rate and the associated additional short- and long-term risks and costs. We present the latest CS rates and trends over the last 24 years. Methods We collected nationally-representative data on CS rates between 1990 to 2014 and calculated regional and subregional weighted averages. We conducted a longitudinal analysis calculating differences in CS rates as absolute change and as the average annual rate of increase (AARI). Results According to the latest data from 150 countries, currently 18.6% of all births occur by CS, ranging from 6% to 27.2% in the least and most developed regions, respectively. Latin America and the Caribbean region has the highest CS rates (40.5%), followed by Northern America (32.3%), Oceania (31.1%), Europe (25%), Asia (19.2%) and Africa (7.3%). Based on the data from 121 countries, the trend analysis showed that between 1990 and 2014, the global average CS rate increased 12.4% (from 6.7% to 19.1%) with an average annual rate of increase of 4.4%. The largest absolute increases occurred in Latin America and the Caribbean (19.4%, from 22.8% to 42.2%), followed by Asia (15.1%, from 4.4% to 19.5%), Oceania (14.1%, from 18.5% to 32.6%), Europe (13.8%, from 11.2% to 25%), Northern America (10%, from 22.3% to 32.3%) and Africa (4.5%, from 2.9% to 7.4%). Asia and Northern America were the regions with the highest and lowest average annual rate of increase (6.4% and 1.6%, respectively). Conclusion The use of CS worldwide has increased to unprecedented levels although the gap between higher- and lower-resource settings remains. The information presented is essential to inform policy and global and regional strategies aimed at optimizing the use of CS.

Caryn Bern

D. Bratzler, E. Dellinger, K. Olsen et al.

These guidelines were developed jointly by the American Society of Health-System Pharmacists (ASHP), the Infectious Diseases Society of America (IDSA), the Surgical Infection Society (SIS), and the Society for Healthcare Epidemiology of America (SHEA). This work represents an update to the previously published ASHP Therapeutic Guidelines on Antimicrobial Prophylaxis in Surgery, as well as guidelines from IDSA and SIS. The guidelines are intended to provide practitioners with a standardized approach to the rational, safe, and effective use of antimicrobial agents for the prevention of surgical-site infections (SSIs) based on currently available clinical evidence and emerging issues. Prophylaxis refers to the prevention of an infection and can be characterized as primary prophylaxis, secondary prophylaxis, or eradication. Primary prophylaxis refers to the prevention of an initial infection. Secondary prophylaxis refers to the prevention of recurrence or reactivation of a preexisting infection. Eradication refers to the elimination of a colonized organism to prevent the development of an infection. These guidelines focus on primary perioperative prophylaxis.

D. Bratzler, E. Dellinger, K. Olsen et al.

The American Thyroid Association Taskforce on Thyr, A. Stagnaro-Ǵreen, M. Abalovich et al.

C. Demets, R. Gordon, D. Argus

R. Garreaud, M. Vuille, R. Compagnucci et al.

A. Quijano

Jidlaph G. Kamoche, Ngũugĩ wa Thiong'o

M. Pratt

R. Alba, V. Nee

P. Molnar, L. Sykes

W. Duellman

John L. Clark

Exploratory field expeditions and herbarium research have led to the discovery of four new species of Drymonia (Gesneriaceae), distinguished by laterally compressed corollas, elongate inflorescence axes, and a nomadic climbing habit. These species, found in Andean forests of Colombia, Ecuador, and Peru, are unique within the Gesneriaceae for bearing inflorescences on a leafless portion of the stem near the ground, while their foliage is restricted to the subcanopy. Named in honor of visionary and inspirational leaders dedicated to advancing conservation, science, and education, the new species are Drymonia clavijoiae J.L.Clark, sp. nov., D. katzensteiniae J.L.Clark, sp. nov., D. rominieckiae J.L.Clark, sp. nov., and D. silvaniae J.L.Clark, sp. nov.

Ramírez-Granados Pablo Ignacio

The study focuses on the hydrogeological characterization of the aquifer system in the central sector of Cartago, Costa Rica. This area was selected due to its significant urbanization and agricultural activities, both of which heavily depend on groundwater resources. The conceptual hydrogeological model was developed using well records, field hydrogeological observations along rivers and material extraction pits, macroscopic sample collection for thin-section analysis, spring and well inventories, and piezometric level analysis. A series of hydrogeological profiles were modeled to visualize the subsurface configuration of hydrogeological units and their relationships with existing geological materials. In areas with sufficient well density and ad¬equate geographic distribution, the groundwater flow dynamics within the hydrogeological units were also analyzed. The results revealed that the aquifer system consists of a variety of materials, predominantly alluvial and laharic deposits, which function as aquifer hydrogeological units. These materials contain interspersed clay lenses, fine sands, and coarse sands, which collectively influence the formation of saturated zones, aquitards, and aquicludes. Additionally, these characteristics determine the degree of confinement of the aquifer units. In some sectors, this confinement results in water upwelling, creating artesian conditions. Flow directions were predominantly oriented from north to south, following the surface gradient, although variations in flow direction highlighted the complexity and interconnectivity of the units. For the first time, the hydrogeological model of the Cartago aquifer system was defined. It comprises the Taras, La Chinchilla, Cartago, El Bosque, Tejar, and Dulce Nombre hydrogeological units. Each of these units corresponds to a specific portion of the study area within the central sector of Cartago, which lies atop the Cartago aquifer system.

Yuting Liang, Jinfeng Wang

The growing number of citations to original publications highlighted their utility across academia, but the dissemination of knowledge from tacit conceptualization to scientific publications and its global applications remains understudied, and the prediction of knowledge trends in a disciplinary context is rare. Addressing the gaps, this paper constructed a tree-like hierarchical model (Geotree) to dissect the knowledge evolution paths of the Geodetector theory (a case) using the Web of Science citation database. Our results revealed that the knowledge evolution of 932 citations to Geodetector was partitioned into periods: a budding period of initial theoretical exploration, a growing period for emerging topics in application, and a mature period marked by significant citation growth. Our test R2 of the predicting model over the next decade, considering the tree-like hierarchy across research directions and disciplines, was 100% higher than that of the other two (from 0.29 to 0.58). The knowledge spreading, from China to North America in 2011, Europe in 2012, Oceania in 2017, South America in 2018, and Africa in 2019, was more associated with a country s production of scientific publications (q-statistic = 0.307***) than its income level. The Geotree modeling of two other cases from space science and physics confirmed the reliability of the source publication-based approach in tracking knowledge diffusion. Our established research framework enriched the current methodology of information science and provided valuable references for policymakers and scholars to enhance their decision-making processes.

D Nunez, F J Nunez Cornu, F de J Escalona-Alcazar et al.

Structural and tectonic features in the Pacific Coast of Mexico generate a high level of seismic activity in the Jalisco block (JB) region, making it one of the most attractive areas of the world for geophysical investigations. The Rivera North America contact zone has been the object of different tectonic studies in recent years framed within the TsuJal project. To this day, this project is generating numerous crucial geophysical results, which significantly improve our understanding of the region. Our study is focused on the interaction between the south of the JB and Rivera plate (RP), which crosses the Middle America trench. We also cover an offshore onshore transect of 130 km length between the eastern Rivera fracture zone and La Huerta region, in the Jalisco state. To characterize this region,we interpreted wide angle seismic, multichannel seismic, and multibeam bathymetry data. The integration of these results, with the local and regional seismicity recorded by the Jalisco Seismic Accelerometric Telemetric Network and by the Mapping the Rivera Subduction Zone experiment, provides new insights into the geometry of the southern RP, which is dipping 12 14 degrees under the JB in the northeast southwest direction. Moreover, our results provide new seismic images of the accretionary wedge, the shallow crust, the deep crust, and the upper-mantle structure along this profile.

Gregory D Scholes, Alexandra Olaya-Castro, Shaul Mukamel et al.

This document summarizes the context and main outcomes of the discussions that took place during the NSF-UKRI bilateral workshop on Quantum Information Science in Chemistry, held on 12-13 February 2024, in Alexandria, Virginia (US). The workshop was jointly funded by the National Science Foundation (NSF) and UK Research and Innovation (UKRI) through the Engineering and Physical Sciences Research Council (EPSRC). It brought together scientific delegations from the United States of America (US) and the United Kingdom (UK).