Invasive rodent responses to experimental and natural hurricanes with implications for global climate change

Hurricanes cause dramatic changes to forests by opening the canopy and depositing debris onto the forest floor. How invasive rodent populations respond to hurricanes is not well understood, but shifts in rodent abundance and foraging may result from scarce fruit and seed resources that follow hurricanes. We conducted studies in a wet tropical forest in Puerto Rico to better understand how experimental (canopy trimming experiment) and natural (Hurricane Maria) hurricane effects alter populations of invasive rodents (Rattus rattus [rats] and Mus musculus [mice]) and their foraging behaviors. To monitor rodent populations, we used tracking tunnels (inked and baited cards inside tunnels enabling identification of animal visitors’ footprints) within experimental hurricane plots (arborist trimmed in 2014) and reference plots (closed canopy forest). To assess shifts in rodent foraging, we compared seed removal of two tree species (Guarea guidonia and Prestoea acuminata) between vertebrate-excluded and free-access treatments in the same experimental and reference plots, and did so 3 months before and 9 months after Hurricane Maria (2017). Trail cameras were used to identify animals responsible for seed removal. Rat incidences generated from tracking tunnel surveys indicated that rat populations were not significantly affected by experimental or natural hurricanes. Before Hurricane Maria there were no mice in the forest interior, yet mice were present in forest plots closest to the road after the hurricane, and their forest invasion coincided with increased grass cover resulting from open forest canopy. Seed removal of Guarea and Prestoea across all plots was rat dominated (75%–100% rat-removed) and was significantly less after than before Hurricane Maria. However, following Hurricane Maria, the experimental hurricane treatment plots of 2014 had 3.6 times greater seed removal by invasive rats than did the reference plots, which may have resulted from rats selecting post-hurricane forest patches with greater understory cover for foraging. Invasive rodents are resistant to hurricane disturbance in this forest. Predictions of increased hurricane frequency from expected climate change should result in forest with more frequent periods of grassy understories and mouse presence, as well as with heightened rat foraging for fruit and seed in preexisting areas of disturbance

Creep of (La0.55Sr0.45)0.99Mn1-yGayO3

Steady-state compressive creep was measured in (La0.55Sr0.45)0.99Mn1−yGayO3 at temperatures from 1200 to 1270 °C in air at stresses (σ) from 13 to 40 MPa. The Ga concentration was y = 0, 0.05, and 0.10. Strains to 0.14 were obtained. In the creep equation for strain rate, = An exp(−Q/RT), stress exponents (n) were between 1.3 and 1.7, indicating that diffusional flow is the dominant creep mechanism, and the activation energy (Q) was found to vary from 355 kJ mol−1 for y = 0 to 485 kJ mol−1 for y = 0.10

Deformación plástica de compuestos mullita/óxido de itrio

Los compuestos a partir de mullita (3Al2 O3 .2SiO2 ) presentan unas magníficas propiedades mecánicas y térmicas. Las mismas características que hacen de la mullita resistente a la deformación plástica, dificultan su densificación. El óxido de itrio es uno de los aditivos más utilizados para reducir la temperatura de sinterización de la mullita. Adicionalmente la presencia de silicatos vítreos (en este caso Y2 Si2 O7 ) incrementan la ductilidad. En esta investigación se han usado muestras de mullita con diversas cantidades de Y2 O3 (0%, 5% y 9% en peso). Los detalles sobre el procesado y caracterización de los compuestos han sido objeto de una publicación previa. Se ha estudiado comparativamente la ductilidad de estos materiales mediante experimentos de deformación en compresión a alta temperatura. Los ensayos se han desarrollado entre 1300 y 1400ºC, en atmósfera de aire, cubriendo un rango de tensiones de compresión entre 0.69 y 34.4 MPa.Mullite (3Al2 O3 .2SiO2 ) based composites have excellent mechanical and thermal properties. The same characteristics that give mullite good resistance to plastic deformation also make its sintering difficult. Yttria is one of the most commonly used additives to reduce sintering temperatures in mullite. Additionally vitreous silicates (Y2 Si2 O7 ) could improve ductility. In this work we have used mullite samples with various amounts of Y2 O3 (0, 5 and 9 wt.%). Details of processing and characterization of these composites have been the subject of a previous publication. We have compared the ductility of these composites by means of compressive deformation tests at elevated temperatures. Creep tests were performed at temperatures between 1300 and 1400ºC, in air, in a stress range of 0.69 to 34.5 MPa

The Edward Bliss Emerson Journal Project: Qualitative Research by a Non-Hierarchical Team

Edward Bliss Emerson (1805-1834), a younger brother of the renowned essayist and poet Ralph Waldo Emerson, lived in the Caribbean for the final three years of his life. His journal and letters are a rich manuscript source for the history of the Danish Virgin Islands (1831-1832) and Puerto Rico (1831-1834). The texts also reflect the contemporary political and cultural situation in the United States, and Edward\u27s search for health, economic independence, intellectual stimulation and metaphysical fulfillment. These writings ignited an intellectual passion in José G. Rigau-Pérez, a physician, medical epidemiologist, and historian in Puerto Rico. Furthering access to these unique resources he produced a digital version of the journal from the Ralph Waldo Emerson Memorial Association deposit at the Houghton Library (Harvard University, Cambridge, Massachusetts) and the letters kept at Houghton Library, the Emerson Family Papers at Massachusetts Historical Society (Boston), and other locations. (See http://edicionesdigitales.info/biblioteca/Emerson.pdf for the full online text of the journal and letters). Dr. José G. Rigau-Pérez also organized a community of scholars who share a sense a common purpose even in the absence of propinquity. The group includes Silvia E. Rabionet, an associate professor in health education at the University of Puerto Rico School of Public Health and Nova Southeastern University College of Pharmacy; Annette B. Ramírez de Arellano, a planner and policy analyst whose work focuses on public health; Wilfredo A. Géigel, a trial lawyer by profession, an independent scholar, member and past president of the Society of Virgin Islands Historians, and Adjunct Professor of History at the University of the Virgin Islands, St. Croix Campus; Raúl Mayo-Santana, an Ad-Honorem Professor at the School of Medicine, University of Puerto Rico; and Alma Simounet, a Professor of English and Linguistics at the University of Puerto Rico. They explore the Emerson journal and letters from multidisciplinary perspectives to bring forth historical, medical, legal, sociological, and geographical insights of the people, times, and places of the mid 1830s in the Caribbean and United States. The work of this talented team resulted in a series of essays we at The Qualitative Report (TQR) are pleased to present as our first book -The Edward Bliss Emerson Journal Project: Qualitative Research by a Non-Hierarchical Team! Under the editorial guidance of TQR Editor Dan Wulff, Dr. Rigau-Pérez and the other members of the team have produced these unique accounts as a transdisciplinary examination of Emerson\u27s world.https://nsuworks.nova.edu/tqr_books/1001/thumbnail.jp

Qualitative Research by a Non-Hierarchical Team

In this and subsequent issues, The Qualitative Report will publish eight articles about a journal written by Edward B. Emerson (1805-1834), a younger brother of American philosopher and writer Ralph Waldo Emerson. This introduction will describe the origins of the project, the sources, the process and the outcomes of the collaboration. The authors hope to document and illustrate the richness and value of interdisciplinary qualitative inquiry, while providing specifics of how the Emerson Journal Project evolved. We provide examples to illustrate the characteristics of effective teamwork, but also present the challenges along the way and how they were surmounted. The breadth of the topics in the journal and the range of expertise within the team have resulted in the use of different approaches to examine Emerson’s text. It is the authors’ goal that these essays will enhance the reading of Emerson´s journal, while contributing to the social and historical understanding of the Caribbean

Activities of imipenem and cephalosporins against clonally related strains of Escherichia coli hyperproducing chromosomal β-lactamase and showing altered porin profiles

Forty clonally related clinical isolates of Escherichia coli from hospitalized patients were resistant to cefoxitin (MICs, >256 μg/ml) and ceftazidime (MICs, 32 to 256 μg/ml) and were intermediate or resistant to cefotaxime (MICs, 16 to 128 μg/ml) but susceptible to both cefepime (MICs, 0.5 to 2 μg/ml) and imipenem (MICs, 0.125 to 0.25 μg/ml). Resistance to β-lactams was related to high-level production of AmpC β-lactamase and loss of OmpF porin

An increase in erythromycin resistance in methicillin-susceptible Staphylococcus aureus from blood correlates with the use of macrolide/lincosamide/streptogramin antibiotics. EARS-Net Spain (2004–2020)

ObjectivesTo describe and analyse erythromycin resistance trends in blood isolates of Staphylococcus aureus (EARS-Net Spain, 2004–2020) and the association of these trends with the consumption of macrolide, lincosamide, and streptogramin B (MLSB) antibiotics. To assess molecular changes that could be involved in erythromycin resistance trends by whole genome analysis of representative isolates.Materials and methodsWe collected antibiotic susceptibility data for all first-blood S. aureus isolates in patients from 47 Spanish hospitals according to EARS-Net criteria. MLSB antibiotic consumption was obtained from the Spanish Agency for Medicines and Medical Devices (2008–2020). We sequenced 137 representative isolates for core genome multilocus sequence typing, resistome and virulome analysis.ResultsFor the 36,612 invasive S. aureus isolates, methicillin resistance decreased from 26.4% in 2004 to 22.4% in 2020. Erythromycin resistance in methicillin-susceptible S. aureus (MSSA) increased from 13.6% in 2004 to 28.9% in 2020 (p < 0.001); however, it decreased from 68.7 to 61.8% (p < 0.0001) in methicillin-resistant S. aureus (MRSA). Total consumption of MLSB antibiotics increased from 2.72 defined daily doses per 1,000 inhabitants per day (DID) in 2014 to 3.24 DID in 2016. By WGS, the macrolide resistance genes detected were erm (59.8%), msrA (46%), and mphC (45.2%). The erm genes were more prevalent in MSSA (44/57, 77.2%) than in MRSA (38/80, 47.5%). Most of the erm genes identified in MSSA after 2013 differed from the predominant ermC gene (17/22, 77.3%), largely because ermT was significantly associated with MSSA after 2013 (11/29, 37.9%). All 13 ermT isolates in this study, except one, belonged to ST398 and came from 10 hospitals and six Spanish provinces.ConclusionThe significant increase in erythromycin resistance in blood MSSA correlated with the consumption of the MLSB antibiotics in Spain. These preliminary data seem support the hypothesis that the human ST398 MSSA clade with ermT-mediated resistance to erythromycin may be involved in this trend

Rethinking Research Ethics for Latinos: The Policy Paradox of Health Reform and the Role of Social Justice

http://dx.doi.org/10.1080/10508422.2012.72999