217,576 research outputs found
Examining the mortality effects of the Irish National Smoking Ban.
Secondhand smoke causes disease and death in those exposed, with cardiovascular and respiratory problems as the most likely outcomes. The purpose of this study was to examine the mortality effects of the Irish national smoking ban of 2004
Changes in the diet and body size of a small herbivorous mammal (hispid cotton rat, \u3ci\u3eSigmodon hispidus\u3c/i\u3e) following the late Pleistocene megafauna extinction
The catastrophic loss of large-bodied mammals during the terminal Pleistocene likely led to cascading effects within communities. While the extinction of the top consumers probably expanded the resources available to survivors of all body sizes, little work has focused on the responses of the smallest mammals. Here, we use a detailed fossil record from the southwestern United States to examine the response of the hispid cotton rat Sigmodon hispidus to biodiversity loss and climatic change over the late Quaternary. In particular, we focus on changes in diet and body size. We characterize diet through carbon (δ13C) and nitrogen (δ15N) isotope analysis of bone collagen in fossil jaws and body size through measurement of fossil teeth; the abundance of material allows us to examine population level responses at millennial scale for the past 16 ka. Sigmodon was not present at the cave during the full glacial, first appearing at ~16 ka after ice sheets were in retreat. It remained relatively rare until ~12 ka when warming temperatures allowed it to expand its species range northward. We find variation in both diet and body size of Sigmodon hispidus over time: the average body size of the population varied by ~20% (90–110 g) and mean δ13C and δ15N values ranged between −13.5 to −16.5‰ and 5.5 to 7.4‰ respectively. A state–space model suggested changes in mass were influenced by diet, maximum temperature and community structure, while the modest changes in diet were most influenced by community structure. Sigmodon maintained a fairly similar dietary niche over time despite contemporaneous changes in climate and herbivore community composition that followed the megafauna extinction. Broadly, our results suggest that small mammals may be as sensitive to shifts in local biotic interactions within their ecosystem as they are to changes in climate and large-scale biodiversity loss
Recent Labour Market Trends in the Visegrad Group Countries
The large declines in the Slovak and Czech employment appeared because the countries' GDPs grew smaller while real wages grew bigger. Shorter working hours and limitations on labour productivity that the two countries introduced could not reverse the unfavourable employment trends that occurred during economic downturn.Duże spadki zatrudnienia w Słowacji i Czechach były związane ze słabym wzrostem PKB i silnym wzrostem płac realnych. Redukcje czasu pracy i wydajności pracy nie były w stanie odwrócić niekorzystnych tendencji w zatrudnieniu
Wolf-Rayets in IC10: Probing the Nearest Starburst
IC10 is the nearest starburst galaxy, as revealed both by its Halpha surface
brightness and the large number of Wolf-Rayet stars (WRs) per unit area. The
relative number of known WC- to WN-type WRs has been thought to be unusually
high (~2), unexpected for IC10's metallicity. In this Letter we report the
first results of a new and deeper survey for WRs in IC10. We sucessfully
detected all of the spectroscopically known WRs, and based upon comparisons
with a neighboring control field, estimate that the total number of WRs in IC10
is about 100. We present spectroscopic confirmation of two of our WR
candidates, both of which are of WN type. Our photometric survey predicts that
the actual WC/WN ratio is ~0.3. This makes the WC/WN ratio of IC 10 consistent
with that expected for its metallicity, but greatly increases the already
unusually high number of WRs, resulting in a surface density that is about 20
times higher than in the LMC. If the majority of these candidates are
spectroscopically confirmed, IC10 must have an exceptional population of high
mass stars.Comment: Accepted by ApJL; only minor correction in this versio
Optimum take-off angle in the long jump
In this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles
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