RESUMO
In recent decades, a large number of hospitals in Pennsylvania and across the United States have been forced to close entirely, or to transform their beds for alternative uses including outpatient care. Hospital closures have severe repercussions for the stakeholders. A better understanding of hospital closures could help take corrective measures to alleviate the adverse impact closures have on communities. Using Pennsylvania Department of Health data compiled from various sources, we address the following questions: Are less efficient hospitals less likely to survive in the long run? What are the effects of quality of care on hospital closures? Does teaching status and location (urban or rural) have any impact on the probability of hospital closure? The result demonstrates several factors of varying significance affect hospital closures/survivals. Hospitals with higher ratio of registered nurses per bed, higher operating margin, lower percentage of revenues from Medicare and Medicaid, and lower competition were less likely to close. Efficiency measures such as DEA efficiency, cost per patient day, and cost per discharge were not found to have a significant impact on hospital closures. The results suggest that hospital administrators may focus more on quality of care and less on cost reduction and efficiency.
RESUMO
To acquire 3-D tracking data on juvenile salmonids, Juvenile Salmon Acoustic Telemetry System (JSATS) cabled hydrophone arrays were deployed in the forebays of two dams on the Snake River and at a mid-reach reservoir between the dams. The depth distributions of fish were estimated by statistical analyses performed on large 3-D tracking data sets from ~33,500 individual acoustic tagged yearling and subyearling Chinook salmon and juvenile steelhead at the two dams in 2012 and subyearling Chinook salmon at the two dams and the mid-reach reservoir in 2013. This research investigated the correlation between vertical migration behavior and passage routes. The depth distributions of fish within the forebays of the dams were significantly different from fish passing the mid-reach reservoir. Fish residing deeper in the forebay tended to pass the dam using deeper powerhouse routes. This difference in depth distributions indicated that the depth distribution of fish at the mid-reach reservoir was not related to behaviors of fish passing through certain routes of the adjacent dams. For fish that were detected deeper than 17.5 m in the forebays, the probability of powerhouse passage (i.e., turbine) increased significantly. Another important finding was the variation in depth distributions during dam passage associated with the diel period, especially the crepuscular periods.
Assuntos
Migração Animal/fisiologia , Comportamento Animal/fisiologia , Salmão/fisiologia , Acústica , Animais , Monitoramento Ambiental/métodos , Oncorhynchus mykiss/fisiologia , Rios , Telemetria/métodosRESUMO
Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently strong signal (150 dB, ref: 1 µPa at 1 meter) that has a detection range of up to 100 meters. Two prototypes, 100 mm and 77 mm long, respectively, weighing only about 1 gram or less in air, were sub-dermally implanted in two species of live fish. Transmissions were successfully detected as the fish swam in a natural manner. This represents the first known implanted energy-harvesting transmitter demonstrated in vivo. Successful development of this transmitter greatly expands the potential for long-term studies of the behaviors of aquatic animals and for subsequently developing strategies to mitigate the environmental impacts of renewable energy systems.
Assuntos
Acústica/instrumentação , Peixes , Implantes Experimentais , Natação , AnimaisRESUMO
Little is known about the three-dimensional depth distributions in rivers of individually marked fish that are in close proximity to hydropower facilities. Knowledge of the depth distributions of fish approaching dams can be used to understand how vulnerable fish are to injuries such as barotrauma as they pass through dams. To predict the possibility of barotrauma injury caused by pressure changes during turbine passage, it is necessary to understand fish behaviour relative to acclimation depth in dam forebays as they approach turbines. A guiding study was conducted using high-resolution three-dimensional tracking results of salmonids implanted with Juvenile Salmon Acoustic Telemetry System transmitters to investigate the depth distributions of subyearling and yearling Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) passing two dams on the Snake River in Washington State. Multiple approaches were evaluated to describe the depth at which fish were acclimated, and statistical analyses were performed on large data sets extracted from â¼28â 000 individually tagged fish during 2012 and 2013. Our study identified patterns of depth distributions of juvenile salmonids in forebays prior to passage through turbines or juvenile bypass systems. This research indicates that the median depth at which juvenile salmonids approached turbines ranged from 2.8 to 12.2â m, with the depths varying by species/life history, year, location (which dam) and diel period (between day and night). One of the most enlightening findings was the difference in dam passage associated with the diel period. The amount of time that turbine-passed fish spent in the immediate forebay prior to entering the powerhouse was much lower during the night than during the day. This research will allow scientists to understand turbine-passage survival better and enable them to assess more accurately the effects of dam passage on juvenile salmon survival.
RESUMO
Turbine-passed fish are exposed to rapid decreases in pressure which can cause barotrauma. The presence of an implanted telemetry tag increases the likelihood of injury or death from exposure to pressure changes, thus potentially biasing studies evaluating survival of turbine-passed fish. Therefore, a neutrally buoyant externally attached tag was developed to eliminate this bias in turbine passage studies. This new tag was designed not to add excess mass in water or take up space in the coelom, having an effective tag burden of zero with the goal of reducing pressure related biases to turbine survival studies. To determine if this new tag affects fish performance or susceptibility to predation, it was evaluated in the field relative to internally implanted acoustic transmitters (JSATS; Juvenile Salmon Acoustic Telemetry System) used widely for survival studies of juvenile salmonids. Survival and travel time through the study reach was compared between fish with either tag type in an area of high predation in the Snake and Columbia rivers, Washington. An additional group of fish affixed with neutrally-buoyant dummy external tags were implanted with passive integrated transponder (PIT) tags and recovered further downstream to assess external tag retention and injury. There were no significant differences in survival to the first detection site, 12 river kilometers (rkm) downstream of release. Travel times were also similar between groups. Conversely, externally-tagged fish had reduced survival (or elevated tag loss) to the second detection site, 65 rkm downstream. In addition, the retention study revealed that tag loss was first observed in fish recaptured approximately 9 days after release. Results suggest that this new tag may be viable for short term (<8 days) single-dam turbine-passage studies and under these situations, may alleviate the turbine passage-related bias encountered when using internal tags, however further research is needed to confirm this.
Assuntos
Salmão/fisiologia , Animais , Monitoramento Ambiental/métodos , Pressão , Rios , Sobrevida , Telemetria/métodos , WashingtonRESUMO
Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae, and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91â days post hatch; d.p.h.) were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma-related injury and mortality were first observed 9â d.p.h., on the same day as initial exogenous feeding. However, barotrauma-related injury did not occur again until swim bladder inflation 75â d.p.h. (visible at necropsy and on radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91â d.p.h. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61 to 153â mm at 91â d.p.h. The use of a combination of decompression tests and radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life-history stages would help to determine the susceptibility of fish to hydro turbine passage and aid in fish conservation.
RESUMO
Environmental forensic microscopy investigations are based on the methods and procedures developed in the fields of criminal forensics, industrial hygiene and environmental monitoring. Using a variety of microscopes and techniques, the environmental forensic scientist attempts to reconstruct the sources and the extent of exposure based on the physical evidence left behind after particles are exchanged between an individual and the environments he or she passes through. This article describes how environmental forensic microscopy uses procedures developed for environmental monitoring, criminal forensics and industrial hygiene investigations. It provides key references to the interdisciplinary approach used in microscopic investigations. Case studies dealing with lead, asbestos, glass fibers and other particulate contaminants are used to illustrate how environmental forensic microscopy can be very useful in the initial stages of a variety of environmental exposure characterization efforts to eliminate some agents of concern and to narrow the field of possible sources of exposure.
Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Ciências Forenses/métodos , Microscopia/métodos , Saúde Pública , Sedimentos Geológicos/análise , Humanos , Resíduos Industriais , Medição de Risco , Abastecimento de Água/análiseRESUMO
Semaphorins are a large class of secreted or membrane-associated proteins that act as chemotactic cues for cell movement via their transmembrane receptors, plexins. We hypothesized that the function of the semaphorin signaling pathway in the control of cell migration could be harnessed by cancer cells during invasion and metastasis. We now report 13 somatic missense mutations in the cytoplasmic domain of the Plexin-B1 gene. Mutations were found in 89% (8 of 9) of prostate cancer bone metastases, in 41% (7 of 17) of lymph node metastases, and in 46% (41 of 89) of primary cancers. Forty percent of prostate cancers contained the same mutation. Overexpression of the Plexin-B1 protein was found in the majority of primary tumors. The mutations hinder Rac and R-Ras binding and R-RasGAP activity, resulting in an increase in cell motility, invasion, adhesion, and lamellipodia extension. These results identify a key role for Plexin-B1 and the semaphorin signaling pathway it mediates in prostate cancer.
Assuntos
Adenocarcinoma/genética , Mutação de Sentido Incorreto , Proteínas de Neoplasias/genética , Proteínas do Tecido Nervoso/genética , Neoplasias da Próstata/genética , Receptores de Superfície Celular/genética , Adenocarcinoma/patologia , Adenocarcinoma/secundário , Neoplasias Ósseas/genética , Neoplasias Ósseas/secundário , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática/genética , Masculino , Invasividade Neoplásica/genética , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/fisiologia , Polimorfismo Conformacional de Fita Simples , Neoplasias da Próstata/patologia , Estrutura Terciária de Proteína , Pseudópodes/ultraestrutura , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/fisiologia , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas ras/metabolismoRESUMO
The first total chemical synthesis of nicotinamide adenine dinucleotide phosphate (beta-NADP, 2) as a single isomer was achieved. This was subsequently converted into the important second messenger nicotinic acid adenine dinucleotide phosphate (p-NAADP) 1 and the identity of this material confirmed by biological evaluation. This flexible synthetic route offers new opportunities for the generation of NAADP 1 analogues that cannot be generated directly from NADP 2 or mainly enzymatic methods.