25 research outputs found
Palaeoclimatic events, dispersal and migratory losses along the Afro-European axis as drivers of biogeographic distribution in Sylvia warblers
<p>Abstract</p> <p>Background</p> <p>The Old World warbler genus <it>Sylvia </it>has been used extensively as a model system in a variety of ecological, genetic, and morphological studies. The genus is comprised of about 25 species, and 70% of these species have distributions at or near the Mediterranean Sea. This distribution pattern suggests a possible role for the Messinian Salinity Crisis (from 5.96-5.33 Ma) as a driving force in lineage diversification. Other species distributions suggest that Late Miocene to Pliocene Afro-tropical forest dynamics have also been important in the evolution of <it>Sylvia </it>lineages. Using a molecular phylogenetic hypothesis and other methods, we seek to develop a biogeographic hypothesis for <it>Sylvia </it>and to explicitly assess the roles of these climate-driven events.</p> <p>Results</p> <p>We present the first strongly supported molecular phylogeny for <it>Sylvia</it>. With one exception, species fall into one of three strongly supported clades: one small clade of species distributed mainly in Africa and Europe, one large clade of species distributed mainly in Africa and Asia, and another large clade with primarily a circum-Mediterranean distribution. Asia is reconstructed as the ancestral area for <it>Sylvia</it>. Long-distance migration is reconstructed as the ancestral character state for the genus, and sedentary behavior subsequently evolved seven times.</p> <p>Conclusion</p> <p>Molecular clock calibration suggests that <it>Sylvia </it>arose in the early Miocene and diverged into three main clades by 12.6 Ma. Divergence estimates indicate that the Messinian Salinity Crisis had a minor impact on <it>Sylvia</it>. Instead, over-water dispersals, repeated loss of long-distance migration, and palaeo-climatic events in Africa played primary roles in <it>Sylvia </it>divergence and distribution.</p
SNAPSHOT USA 2019 : a coordinated national camera trap survey of the United States
This article is protected by copyright. All rights reserved.With the accelerating pace of global change, it is imperative that we obtain rapid inventories of the status and distribution of wildlife for ecological inferences and conservation planning. To address this challenge, we launched the SNAPSHOT USA project, a collaborative survey of terrestrial wildlife populations using camera traps across the United States. For our first annual survey, we compiled data across all 50 states during a 14-week period (17 August - 24 November of 2019). We sampled wildlife at 1509 camera trap sites from 110 camera trap arrays covering 12 different ecoregions across four development zones. This effort resulted in 166,036 unique detections of 83 species of mammals and 17 species of birds. All images were processed through the Smithsonian's eMammal camera trap data repository and included an expert review phase to ensure taxonomic accuracy of data, resulting in each picture being reviewed at least twice. The results represent a timely and standardized camera trap survey of the USA. All of the 2019 survey data are made available herein. We are currently repeating surveys in fall 2020, opening up the opportunity to other institutions and cooperators to expand coverage of all the urban-wild gradients and ecophysiographic regions of the country. Future data will be available as the database is updated at eMammal.si.edu/snapshot-usa, as well as future data paper submissions. These data will be useful for local and macroecological research including the examination of community assembly, effects of environmental and anthropogenic landscape variables, effects of fragmentation and extinction debt dynamics, as well as species-specific population dynamics and conservation action plans. There are no copyright restrictions; please cite this paper when using the data for publication.Publisher PDFPeer reviewe
Cardiac augmentation by phasic high intrathoracic pressure support in man
Left ventricular performance can be significantly influenced by changes in intrathoracic pressure. In man, sustained increases in intrathoracic pressure unload the left ventricle, but since venous return decreases, increased intrathoracic pressure is associated with a decreased cardiac output. In a canine model of acute ventricular failure, it has been shown that phasic increases in intrathoracic pressure, which do not decrease venous return, improve steady-state cardiac output. We thus studied the cardiovascular effects of phasic high intrathoracic pressure support (PHIPS) in seven patients with shock in our intensive care unit whose condition was not responsive to conventional types of therapy. The PHIPS was generated by abdominal and chest wall binding during positive-pressure ventilation. As compared to the state before PHIPS, the PHIPS was associated with an increase in esophageal pressure (6.6 ± 1.1 mm Hg; p<0.01) and in mean arterial pressure (43.0 ± 6.1 to 51.0± 7.7 mm Hg; p<0.01) while not changing arterial pressure relative to esophageal pressure. Cardiac output also increased from 3.6±0.5 to 4.2±0.6 L/min (p<0.05), while left ventricular filling pressures remained constant. In one subject a gated cardiac blood pool scan demonstrated a PHIPS-associated increase in ejection fraction and decreased end-diastolic volume. These results are consistent with the hypothesis that PHIPS, by increasing intrathoracic pressure, augments left ventricular performance by reducing left ventricular afterload. This appears to be a promising area for future research
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Changing pattern of organ dysfunction in early human sepsis is related to mortality
The Effects of Granulocyte Colony-Stimulating Factor and Neutrophil Recruitment on the Pulmonary Chemokine Response to Intratracheal Endotoxin
The Effects of Ibuprofen on the Physiology and Survival of Patients with Sepsis
Sepsis is associated with a mortality rate of 30 to 50 percent and with substantial morbidity.
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The relative contributions of the inflammatory response and infection to these adverse outcomes are unknown.
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In animal models of sepsis, treatment with nonsteroidal antiinflammatory drugs improves survival and reduces physiologic abnormalities.
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The synthesis of prostaglandin and thromboxane has been linked with abnormalities of airway mechanics, pulmonary hypertension, hypoxemia, cardiovascular collapse, and multiple organ failure in animals and in humans with the sepsis syndrome.
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Ibuprofen has been shown to have effects on sepsis in humans, but because of their small samples (fewer . .
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Effects of ibuprofen on the physiology and survival of hypothermic sepsis
OBJECTIVESThe objective was to compare the clinical and physiologic characteristics of febrile septic patients with hypothermic septic patients; and to examine plasma levels of cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) and the lipid mediators thromboxane B2 (TxB2) and prostacyclin in hypothermic septic patients in comparison with febrile patients. Most importantly, we wanted to report the effect of ibuprofen treatment on vital signs, organ failure, and mortality in hypothermic sepsis.
SETTINGThe study was performed in the intensive care units (ICUs) of seven clinical centers in the United States and Canada.
PATIENTSFour hundred fifty-five patients admitted to the ICU who met defined criteria for severe sepsis and were suspected of having a serious infection.
INTERVENTIONIbuprofen at a dose of 10 mg/kg (maximum 800 mg) was administered intravenously over 30 to 60 mins every 6 hrs for eight doses vs. placebo (glycine buffer vehicle).
MEASUREMENTS AND MAIN RESULTSForty-four (10%) septic patients met criteria for hypothermia and 409 were febrile. The mortality rate was significantly higher in hypothermic patients, 70% vs. 35% for febrile patients. At study entry, urinary metabolites of TxB2, prostacyclin, and serum levels of TNF-alpha and IL-6 were significantly elevated in hypothermic patients compared with febrile patients. In hypothermic patients treated with ibuprofen, there was a trend toward an increased number of days free of major organ system failures and a significant reduction in the 30-day mortality rate from 90% (18/20 placebo-treated patients) to 54% (13/24 ibuprofen-treated patients).
CONCLUSIONSHypothermic sepsis has an incidence of [similar]10% and an untreated mortality twice that of severe sepsis presenting with fever. When compared with febrile patients, the hypothermic group has an amplified response with respect to cytokines TNF-alpha and IL-6 and lipid mediators TxB2 and prostacyclin. Treatment with ibuprofen may decrease mortality in this select group of septic patients. (Crit Care Med 1999; 27:699-707