RESUMO
As the only living species within the odobenid lineage of carnivores, walruses (Odobenus rosmarus) have no close relatives from which auditory information can be extrapolated. Sea lions and fur seals in the otariid lineage are the nearest evolutionary outgroup. To advance understanding of odobenid and otariid hearing, we conducted behavioral testing with two walruses and one California sea lion (Zalophus californianus). Detection thresholds for airborne sounds were measured from 0.08 to at least 16 kHz in ambient noise conditions and then re-measured in the presence of octave-band white masking noise. Walruses were more sensitive than the sea lion at lower frequencies and less sensitive at higher frequencies. Critical ratios for the walruses ranged from 20 dB at 0.2 kHz to 32 dB at 10 kHz, while critical ratios for the sea lion ranged from 16 dB at 0.2 kHz to 35 dB at 32 kHz. The masking values for these species are comparable to one another and to those of terrestrial carnivores, increasing by about 3 dB per octave with increasing frequency. Despite apparent differences in hearing range and sensitivity, odobenids and otariids have a similar ability to hear signals in noisy conditions.
Assuntos
Leões-Marinhos , Animais , Morsas , Audição , Evolução Biológica , SomRESUMO
The scale and pace of energy infrastructure development required to achieve net-zero greenhouse gas (GHG) emissions are unprecedented, yet our understanding of how to minimize its potential impacts on land and ocean use and natural resources is inadequate. Using high-resolution energy and land-use modeling, we developed spatially explicit scenarios for reaching an economy-wide net-zero GHG target in the western United States by 2050. We found that among net-zero policy cases that vary the rate of transportation and building electrification and use of fossil fuels, nuclear generation, and biomass, the "High Electrification" case, which utilizes electricity generation the most efficiently, had the lowest total land and ocean area requirements (84,000 to 105,000 km2 vs. 88,100 to 158,000 km2 across all other cases). Different levels of land and ocean use protections were applied to determine their effect on siting, environmental and social impacts, and energy costs. Meeting the net-zero target with stronger land and ocean use protections did not significantly alter the share of different energy generation technologies and only increased system costs by 3%, but decreased additional interstate transmission capacity by 20%. Yet, failure to avoid development in areas with high conservation value is likely to result in substantial habitat loss.
RESUMO
BACKGROUND: Pathogenic species in deep tissue infections after soft-tissue sarcoma (STS) resection is largely unstudied, particularly the role of anaerobic bacteria, risks factors for those pathogens, and the time course of infection presentation. METHODS: Retrospective analysis of 64 patients requiring operative debridement for deep tissue infection after STS resection was undertaken to identify infectious species and study risk factors for anaerobic infections. Kaplan-Meier methods examined the time course of infection presentation. RESULTS: STS subtypes were most commonly pleomorphic STS, myxofibrosarcoma, and undifferentiated STS. Staphylococcus aureus was the most common organism isolated (56%). Twenty (31%) infections were positive for ≥1 anaerobic organism. Twelve gram-positive and 10 gram-negative aerobic organisms were isolated. Most (90%) anaerobic-containing infections were polymicrobial, vs 52% of purely aerobic infections. No significant risk factors for anaerobic infections were identified. Median time from tumor resection until debridement was significantly greater for anaerobic infections (54.5 days) than for purely aerobic infections (29.5 days; P = 0.004), a difference so pronounced that using "presentation after 53 days" as a proxy for the presence of anaerobic pathogens had an accuracy of 81%. CONCLUSIONS: Because polymicrobial and anaerobic bacterial infections are common, we strongly support antibiotic use with anaerobic coverage at debridement, particularly for infections presenting later.
Assuntos
Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Sarcoma/microbiologia , Sarcoma/cirurgia , Estudos de Coortes , Desbridamento/métodos , Feminino , Infecções por Bactérias Gram-Negativas/etiologia , Infecções por Bactérias Gram-Negativas/cirurgia , Infecções por Bactérias Gram-Positivas/etiologia , Infecções por Bactérias Gram-Positivas/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/microbiologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/cirurgia , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Ehlers-Danlos syndrome is a rarely encountered connective tissue disorder characterized by skin hyper-elasticity, joint hyper-flexibility, and vasculature fragility. We report a 41-year-old female presenting with scalp swelling following minor head trauma. The patient presented with a large cephalohematoma that despite compressive measures and Factor IX administration continued to progress, necessitating transfer for definitive surgical intervention. The patient underwent surgical evacuation of approximately 1 liter of blood, followed by drain placement and compression dressing. This case underscores the importance for emergency physicians to recognize the potential vascular catastrophes these patients may present with following even minor injury.
RESUMO
We have designed and implemented a practical nanoelectronic interface to G-protein coupled receptors (GPCRs), a large family of membrane proteins whose roles in the detection of molecules outside eukaryotic cells make them important pharmaceutical targets. Specifically, we have coupled olfactory receptor proteins (ORs) with carbon nanotube transistors. The resulting devices transduce signals associated with odorant binding to ORs in the gas phase under ambient conditions and show responses that are in excellent agreement with results from established assays for OR-ligand binding. The work represents significant progress on a path toward a bioelectronic nose that can be directly compared to biological olfactory systems as well as a general method for the study of GPCR function in multiple domains using electronic readout.