4,184 research outputs found
Reproductive Performance and Condition of White-Tailed Deer in Ohio
Author Institution: Ohio Department of Natural Resources, Division of WildlifeInformation on reproductive performance and body condition in white-tailed deer (Odocoileus virginianus) was obtained in 1981-83 for the glaciated farmland and unglaciated hill country regions of Ohio. Uterine analysis of 275 farmland does and 129 hill country does showed that farmland fawns had a higher reproductive rate (0.85 fetus/doe) than did hill country fawn does (0.62 fetus/doe). Fetuses:doe ratios for yearlings (farmland = 1.89, hill country = 1.84) and adults (farmland = 1.85, hill country = 1.78) were similar and did not differ between regions. Most (>75%) pregnant fawn does carried only one fetus; most (>70%) yearling and adult does carried twins or had triplets. Fetal sex ratios differed from the expected 50:50 only for adult does from the farmland region (40% male fetuses). Does from Ohio's farmland region were consistently and significantly heavier, and yearling males had larger average antler beam diameter and more points than deer of the same sex and age from the hill country region. Body weights, antler characteristics, and reproductive rates for Ohio are typical of deer on a high nutritional plane, allowing white-tailed deer in both regions to approach full reproductive potential. A representative 100 does in the farmland and hill country regions could produce 147 and 140 fetuses, respectively. Because of regional age structure differences, a representative 100 deer of both sexes could produce 83 fetuses in both regions
Use of normalized word vector approach in document classification for an LKMC
In order to realize the objective of expanding library services to provide knowledge managementsupport for small businesses, a series of requirements must be met. This particular phase of a largerresearch project focuses on one of the requirements: the need for a document classificationsystem to rapidly determine the content of digital documents. Document classification techniquesare examined to assess the available alternatives for realization of Library Knowledge ManagementCenters (LKMCs). After evaluating prominent techniques the authors opted to investigate aless well-known method, the Normalized Word Vector (NWV) approach, which has been usedsuccessfully in classifying highly unstructured documents, i.e., student essays. The authors proposeutilizing the NWV approach for LKMC automatic document classification with the goal ofdeveloping a system whereby unfamiliar documents can be quickly classified into existing topiccategories. This conceptual paper will outline an approach to test NWV's suitability in this area
Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures
Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control
Overcoming the common pool problem through voluntary cooperation: the rise and fall of a fishery cooperative
We analyze a seldom used, but highly promising form of rights-based management over common pool resources that involves the self-selection of heterogeneous fishermen into sectors. The fishery management regime assigns one portion of an overall catch quota to a voluntary cooperative, with the remainder exploited as a commons by those choosing to fish independently. Data from an Alaska commercial salmon fishery confirm our model's key predictions, that the co-op would facilitate the consolidation of fishing effort, coordination of harvest activities, sharing of information and provision of shared infrastructure. We estimate that the resulting rent gains were at least 25%. A lawsuit filed by two disgruntled independents led to the co-op's demise, an outcome also predicted by our model. Our analysis provides guidance for designing fishery reform that leads to Pareto improvements for fishermen of all skill levels, which suggests a structure that enables reform without losers.
CLASSIFICATION OF EXPLOSIVES TRANSFORMATION PRODUCTS IN PLANT TISSUE
Explosives contamination in surface or groundwater used for the irrigation of food crops and phytoremediation of explosives-contaminated soil or water using plant-assisted biodegradation have brought about concerns as to the fate of explosives in plants. Liquid scintillation counting, high-performance liquid chromatography, and gel permeation chromatography were utilized to characterize explosives (hexahydro-1,3,5-trinitro-1,3,5-triazine and trinitrotoluene) and their metabolites in plant tissues obtained from three separate studies. Analyzing tissues of yellow nutsedge (Cyperus esculentus), corn (Zea mays), lettuce (Lacuta sativa), tomato (Lyopersicum esculentum), radish (Raphanus sativus), and parrot feather (Myriophyllum aquaticum) from three studies where exposure to explosives at nontoxic levels (1–2 mg/L in water) occurred showed that extensive transformation of the explosive contaminant occurred, variations were noted in uptake and transformation between terrestrial and aquatic plants, the products had significantly higher polarity and water solubility than the parent compounds, and the molecular sizes of the transformation products were significantly greater than those of the parent compounds (approximately 300 times greater)
Testing the universality of star formation - I. Multiplicity in nearby star-forming regions
We have collated multiplicity data for five clusters (Taurus, Chamaeleon I, Ophiuchus, IC 348 and the Orion Nebula Cluster). We have applied the same mass ratio (flux ratios of ΔK≤ 2.5) and primary mass cuts (∼0.1-3.0 M⊙) to each cluster and therefore have directly comparable binary statistics for all five clusters in the separation range 62-620 au, and for Taurus, Chamaeleon I and Ophiuchus in the range 18-830 au. We find that the trend of decreasing binary fraction with cluster density is solely due to the high binary fraction of Taurus; the other clusters show no obvious trend over a factor of nearly 20 in density. With N-body simulations, we attempt to find a set of initial conditions that are able to reproduce the density, morphology and binary fractions of all five clusters. Only an initially clumpy (fractal) distribution with an initial total binary fraction of 73 per cent (17 per cent in the range 62-620 au) is able to reproduce all of the observations (albeit not very satisfactorily). Therefore, if star formation is universal, then the initial conditions must be clumpy and with a high (but not 100 per cent) binary fraction. This could suggest that most stars, including M dwarfs, form in binarie
- …