Winter habitat selection patterns of Merriam's turkeys in the southern Black Hills, South Dakota

In northern areas of their expanded range, information on Merriam's turkeys ( Meleagris gallopavo merriami ) is lacking, specifically pertaining to wintering behavior and factors associated with winter habitat selection. Forest managers need detailed quantification of the effects of logging and other management practices on wintering habitats needed by Wild Turkeys and other wildlife. Therefore, we examined winter habitat selection patterns within ponderosa pine ( Pinus ponderosa ) forests and determined factors associated with use of farmsteads by Merriam's turkeys in the southern Black Hills, South Dakota. We radio-marked 86 female Merriam's turkeys (70 adults and 16 yearlings) and monitored them during winter (1 December–31 March), 2001–2004. Female Wild Turkeys used recently burned pine forest less than expected but selected farmsteads and stands of mature ponderosa pine ( 22.9 cm diameter at breast height [DBH] trees) for foraging sites. Within forests, female Wild Turkeys selected foraging sites with less understory vegetation and visual obstruction, and larger-diameter ponderosa pine. Ponderosa pine seed abundance varied among years, and pine seeds were most abundant in stands of 30–35 cm DBH with basal area of 22–28 m2 ? ha–1. Abundance of pine seeds may have influenced use of farmsteads by Wild Turkeys, more so than ambient temperatures or snow depth. In the southern Black Hills, management should emphasize open- to mid-canopy and mature-structural-stage pine stands, where seed production was greatest. During winters when mast from pine is unavailable, farmsteads likely provide nutritional supplementation and may be important for maintaining Merriam's turkey populations.     

Effects of elevation and genetic introgression on growth of Colorado River cutthroat trout

Inland populations of cutthroat trout have suffered dramatic declines and some subspecies are considered threatened or endangered. Understanding patterns of variation and factors that influence life history in populations is important for conservation and management. We determined effects of elevation, sex, and genetic introgression (with Yellowstone cutthroat trout, Oncorhynchus clarkii lewisi , and rainbow trout, Oncorhynchus mykiss ) on growth rates of Colorado River cutthroat trout ( Oncorhynchus clarkii pleuriticus ) in the Sheep Creek drainage in the Uinta Mountains of Utah. In this high-elevation system, native trout grew slowly and matured relatively late. Elevation, sex, and genetic introgression all had significant effects on growth rates. Growth rates were lower at higher elevations. Males were slightly larger than females, and cutthroat trout in locations that were more introgressed grew faster than those at nonintrogressed locations. Both abiotic effects and effects of introduced salmonids must be addressed in long-term management programs to ensure the sustainability of native trout populations.     

Effects of habitat disturbance on diets of Great Horned Owl ( Bubo virginianus ) in a cold desert

To determine the potential effect of habitat disturbance, Great Horned Owl ( Bubo virginianus ) diets were quantified in disturbed and undisturbed habitats over a 2-year period at Dugway Proving Ground in the Great Basin Desert of Tooele County, Utah. Invertebrates were the most abundant prey by count, whereas mammals constituted the majority of diet by biomass. Species richness in the diet did not differ between habitats or among seasons after correcting for the number of pellets in each sample. However, the number of vertebrate species was greater than the number of invertebrate species in the diet, and this ratio differed between disturbed and undisturbed habitats. Invertebrate species made up a greater proportion of total species richness in the diet in the undisturbed than the disturbed habitat. Nineteen species occurred in the diet in only 1 of the 2 habitat types (7 unique species in disturbed habitat, 12 unique species in undisturbed), but all such species were rare and contributed little both by count and biomass to the overall diet. Of the 20 most important species found in owl diets in both habitats (based on percent biomass), none were more common in 1 habitat than the other after correcting for multiple tests. Although there were minor differences in the diet between disturbed and undisturbed habitats, habitat alteration and degradation of native vegetation on Dugway Proving Ground did not affect the major components of the diet of Great Horned Owls.     

INCIDENCE MATRIX APPROACH FOR CALCULATING READINESS LEVELS

Contemporary system maturity assessment approaches have failed to provide robust quantitative system evaluations resulting in increased program costs and developmental risks.Standard assessment metrics,such as Technology Readiness Levels（TRL）,do not sufficiently evaluate increasingly complex systems.The System Readiness Level（SRL）is a newly developed system development metric that is a mathematical function of TRL and Integration Readiness Level（IRL） values for the components and connections of a particular system.SRL acceptance has been hindered because of concerns over SRL mathematical operations that may lead to inaccurate system readiness assessments.These inaccurate system readiness assessments are called readiness reversals.A new SRL calculation method using incidence matrices is proposed to alleviate these mathematical concerns.The presence of SRL readiness reversal is modeled for four SRL calculation methods across several system configurations.Logistic regression analysis demonstrates that the proposed Incidence Matrix SRL（IMSRL）method has a decreased presence of readiness reversal than other approaches suggested in the literature.Viable SRL methods will foster greater SRL adoption by systems engineering professionals and will support system development risk reduction goals.     

Home-range size and overlap of sympatric male mule and white-tailed deer in Texas

Information about the ecology of sympatric male deer is limited, which may influence management strategies for these species. We estimated home-range and core-area sizes and overlap, and survival of sympatric male desert mule deer ( Odocoileus hemionus eremicus ) and white-tailed deer ( Odocoileus virginianus ) in west central Texas. We captured 18 males of each species, fitted them with radio-collars, and monitored them for mortality from 2000 through 2003. We calculated home ranges for 7 males of each species in 2001 and 2002. Home-range sizes of mule deer (8.8 km 2 ) and white-tailed deer (7.4 km 2 ) were similar. Interspecific home-range overlap was less common than intraspecific overlap. Mean annual survival was 0.76 (SE = 0.04) for mule deer and 0.80 (SE = 0.06) for white-tailed deer. The high degree of home-range overlap and similar survival between the 2 deer species suggest that management targeting only 1 species may be unfeasible.     

The Role of Symmetry in Mathematics

Over the past few decades the notion of symmetry has played a major role in physics and in the philosophy of physics. Philosophers have used symmetry to discuss the ontology and seeming objectivity of the laws of physics. We introduce several notions of symmetry in mathematics and explain how they can also be used in resolving different problems in the philosophy of mathematics. We use symmetry to discuss the objectivity of mathematics, the role of mathematical objects, the unreasonable effectiveness of mathematics and the relationship of mathematics to physics.     

Food spectrum analysis of the Asian toad,Duttaphrynus melanostictus (Schneider, 1799) (Anura: Bufonidae), from Timor Island,Wallacea

The Asian toad, Duttaphrynus melanostictus (Schneider, 1799), is widespread throughout tropical Asia and very abundant where it occurs. It was relatively recently introduced to Timor, the second largest island in the biogeographic region called Wallacea. Timor Island shows an exceptionally high level of endemism in a wide range of faunal groups and there are concerns that D. melanostictus may have a negative impact on this diversity, including vertebrates, through direct predation. To evaluate the impact the diet of D. melanostictus might have on the local fauna, gut contents of 83 preserved toad specimens from five habitat types in Timor-Leste, a country occupying the eastern half of Timor Island, were examined. We identified 5581 prey items, comprising the following animal groups: annelids; snails and slugs; spiders and harvestmen; woodlice; millipedes and centipedes; grasshoppers, crickets and earwigs; termites; thrips and true bugs; beetles; ants; hymenopterans other than ants; true flies; butterflies; unidentified insects; and insect larvae. Small eusocial insects (ants and termites) constituted the major part of the diet (61.6% and 23.4%, respectively). No vertebrate prey was recorded. Prey item composition did not differ between habitats. The wide prey spectrum well indicates that D. melanostictus is a generalist invertebrate feeder, as other studies, from regions where this species occurs naturally, have already shown. Although the Asian toad seems to not generally prey on vertebrates, vertebrate species that are morphologically similar to invertebrates in their overall appearance may be consumed. Hence, a negative effect on some taxa (e.g. blindsnakes) may be possible. We also present some limited data on intestinal parasites occurring in D. melanostictus.     

Fancd2 counteracts the toxic effects of naturally produced aldehydes in mice

Reactive aldehydes are common carcinogens. They are also by-products of several metabolic pathways and, without enzymatic catabolism, may accumulate and cause DNA damage. Ethanol, which is metabolised to acetaldehyde, is both carcinogenic and teratogenic in humans. Here we find that the Fanconi anaemia DNA repair pathway counteracts acetaldehyde-induced genotoxicity in mice. Our results show that the acetaldehyde-catabolising enzyme Aldh2 is essential for the development of Fancd2(-/-) embryos. Nevertheless, acetaldehyde-catabolism-competent mothers (Aldh2(+/-)) can support the development of double-mutant (Aldh2(-/-)Fancd2(-/-)) mice. However, these embryos are unusually sensitive to ethanol exposure in utero, and ethanol consumption by postnatal double-deficient mice rapidly precipitates bone marrow failure. Lastly, Aldh2(-/-)Fancd2(-/-) mice spontaneously develop acute leukaemia. Acetaldehyde-mediated DNA damage may critically contribute to the genesis of fetal alcohol syndrome in fetuses, as well as to abnormal development, haematopoietic failure and cancer predisposition in Fanconi anaemia patients.