3,511 research outputs found
RELATIONSHIP OF RACCOON ROAD-KILL DATA TO HIGH-DENSITY MARINE TURTLE NESTING
Four ycars of data from a hiyh-density n~arine turtle nesting hcach at John D. MacArthur Beach Statc Park, Florida wcrc examined along with data on raccoon (Procyon lotor.) ruad-kills from adjaccnt roads, and data on park attendance (as an index of local traffic) to make infcrcnces about raccoon activity patterns relative to turtle ncsting. Raccoon road-kills were found Lo diminish subsiantially during turtle nesting, even though local traffic was constant or increasing. Opossums (Didelphis virginiana). the only other maminal consistcntly foluid as road-kills, did not show a decrease during ti~rtlen esting season, but they are not known as a primary predator of turtle nests. We concluded that duriny turtlc nestiny raccoons are drawn to the beach to prey on the abundant food resource of turtle eggs, and they do not leave the beach until the end of turtle nesting season. High nu~nbcrso f raccoon road-kills during the fall-wintcr, followed by a decrease in the spring around the start of turtle nesting season, might be ured as indicators to initiate management actions to protect turtle nests
Use of roadkill data to index and relate raccoon activity at a heavily predated, high-density marine turtle nesting beach
Four years of data from a high-density marine turtle nesting beach at John D. MacArthur Beach State Park, Florida were examined along with data on raccoon road-kills from adjacent roads, and data on park attendance (as an index of local traffic) to make inferences about raccoon activity patterns relative to turtle nesting. Raccoon road-klls were found to diminish substantially during turtle nesting, even though local traffic was constant or increasing. Opossums, the only other mammal consistently found as road-kills, did not show a decrease during turtle nesting season, but they are not known as a primary predator of turtle nests. We concluded that during turtle nesting raccoons are drawn to the beach to prey on the abundant nesting raccoons food resource of turtle eggs, and they do not leave the beach until the end of turtle nesting season. High numbers of raccoon road-kills during the fall-winter, followed by a decrease in the spring around the start of turtle nesting season, might be used as indicators to initiate management actions to protect turtle nests
Geographic Variation in Temperature Tolerance as an Indicator of Potential Population Responses to Climate Change
The temperature tolerances of individuals in geographically separated populations of a single species can be used as indicators of each population\u27s potential to persist or become extinct in response to climate change. We evaluated the population-level variation in temperature tolerance in populations of several marine invertebrate taxa, including bryozoans, tunicates, bivalves, and gastropods, separated by distances of \u3c 200 km to \u3e 5000 km. We then combined physiological thermotolerance data with current temperature data and climate change predictions to predict which of these populations may be most vulnerable to future changes. In a trans-continental comparison of four subtidal epibenthic species, we show that populations on the east coast of the United States, which experienced higher habitat temperatures than those on the west coast, had higher thermal tolerances but lived closer to individuals\u27 tolerance limits. Similarly, temperature tolerances varied between western and eastern Atlantic populations of the mussel Mytilus edulis; however, these differences only emerged after repeated exposures to high temperatures. Furthermore, the less thermotolerant M. edulis population in the western Atlantic was more susceptible to temperature increases, as evidenced by a recent range contraction. Thus, for both the subtidal epibenthic and intertidal mussel species, we identified the western Atlantic as a âhot spotâ of populations susceptible to climate change compared to those in the eastern Pacific and eastern Atlantic, respectively. Finally, because current tolerances are not the sole indicators of individuals\u27 abilities to cope with temperature increases, we also assessed the possibility for acclimatization to facilitate the persistence of populations via the buffering of temperature effects. We show that, for four populations of intertidal Littorina snail species in the northwest Atlantic, most populations were able to overcome geographic differences in temperature tolerance via acclimation. When acclimation capacity is low, the potential for ârescueâ may depend on the particular species\u27 life-history strategy and dispersal ability. For example, although individuals from the coldest-adapted population of Littorina littorea were unable to acclimate as quickly as those from more southern populations, this species has a pelagic larval stage and, thus, the greatest dispersal potential of these littorines. Together, these studies highlight the importance of considering variation in temperature tolerance between populations within species to improve the forecasting of changes in the abundances and distributions of species in response to climate warming
An unexpected cause of pericardial effusion
We present a case of pericardial effusion due to embolization of a fragment of an inferior vena cava (IVC) filter, with subsequent perforation of the right ventricle. This is a rare and unexpected cause of pericardial effusion. Fracture or embolization of IVC filters is a relatively uncommon complication, but these events may have serious clinical implications. Although IVC filters are often placed with the intent of removal, the device in many patients is never removed. The long-term implications of IVC filter placement must be kept in mind when making decisions about device placement and subsequent removal
Systematic uncertainties in the precise determination of the strangeness magnetic moment of the nucleon
Systematic uncertainties in the recent precise determination of the
strangeness magnetic moment of the nucleon are identified and quantified. In
summary, G_M^s = -0.046 \pm 0.019 \mu_N.Comment: Invited presentation at PAVI '04, International Workshop on Parity
Violation and Hadronic Structure, Laboratoire de Physique Subatomique et de
Cosmologie, Grenoble, France, June 8-11, 2004. 7 pages, 16 figure
Spanish Language Use Across Generations and Depressive Symptoms Among US Latinos
Acculturation markers, such as language use, have been associated with Latino depression. Language use may change between generations; however, few studies have collected intergenerational data to assess how language differences between generations impact depression. Using the Niños Lifestyle and Diabetes Study (2013â2014), we assessed how changes in Spanish language use across two generations of Mexican-origin participants in Sacramento, California, influenced offspring depressive symptoms (N = 603). High depressive symptoms were defined as CESD-10 scores â„ 10. We used log-binomial and linear-binomial models to calculate prevalence ratios and differences, respectively, for depressive symptoms by language use, adjusting for identified confounders and within-family clustering. Decreased Spanish use and stable-equal English/Spanish use across generations protected against depressive symptoms, compared to stable-high Spanish use. Stable-low Spanish use was not associated with fewer depressive symptoms compared to stable-high Spanish use. Exposure to multiple languages cross-generationally may improve resource access and social networks that protect against depression
Absence of a dose-rate effect in the transformation of C3H 10T1/2 cells by α-particles
The findings of Hill et al. (1984) on the greatly enhanced transformation frequencies at very low dose rates of fission neutrons induced us to perform an analogous study with -particles at comparable dose rates. Transformation frequencies were determined with γ-rays at high dose rate (0·5 Gy/min), and with -particles at high (0·2 Gy/min) and at low dose rates (0·83-2·5 mGy/min) in the C3H 10T1/2 cell system.
α-particles were substantially more effective than γ-rays, both for cell inactivation and for neoplastic transformation at high and low dose rates. The relative biological effectiveness (RBE) for cell inactivation and for neoplastic transformation was of similar magnitude, and ranged from about 3 at an -particle dose of 2 Gy to values of the order of 10 at 0·25 Gy. In contrast to the experiments of Hill et al. (1984) with fission neutrons, no increased transformation frequencies were observed when the -particle dose was protracted over several hours
Redox Potentials and Denitrification in a Cropped Potato Processing Waste Water Disposal Field
Many potato processors apply processing waste water containing
nitrogen and other plant nutrients to cropped land. More than 1
metric ton of N per hectare was applied each year when waste water
application averaged 230 cm/year on one field for 2 years. Less
than 300 kg N/ha was recovered in the harvested grass hay, and
only about 15 kg N/ha leached each season. Redox measurements
made at several depths from 5 to 150 cm showed poorly aerated
zones in the soil profile because of a high water table during the
summer. Under these conditions, nitrate leached into these poorly
aerated zones would be denitrified. Sufficient decomposable organic
matter was present to provide energy for denitrification
Redox Potentials in a Cropped Potato Processing Waste Water Disposal Field with a Deep Water Table
Redox potential measurements were made in a field irrigated with
potato processing waste water at seven depths of 5 to 150 cm for 14
mo. Irrigation with canal water mixed with waste water in the summer,
and with waste water in the winter, decreased redox potentials in
the field at some depths for a short time but not enough to cause denitrification.
However, as the soil temperature increased in the spring,
and decomposition of the accumulated waste organic matter accelerated,
redox potentials decreased after each irrigation at all observed
depths. During April, redox potentials low enough to promote denitrification
(below + 225 mV) at 90-, 120-, and 150-cm depths in the soil
persisted for 2 weeks. Irrigation with nondiluted waste water in June
and July decreased redox potentials and denitrification occurred for
up to 3 days after irrigations. As the soil temperature increased in the
spring, nitrification of accumulated organic matter increased son nitrates.
Waste water irrigations from April to July promoted denitrification,
removing most of the nitrate from the soil, and thereby decreasing
the potential for ground water pollution
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