1,399 research outputs found
Sexual Dimorphic Social Development and Female Intrasexual Chemical Signaling of African Elephants (Loxodonta africana)
Author\u27s abstract: African elephants are a polygynous species in which males and females carry out dimorphic lifestyles. Males search and compete for reproductively active females, while females care for offspring and facilitate group cohesion. The objectives of this study was a) to compare the development of sexually dimorphic behaviors and developmental trends between young male and female wild African elephants and b) to determine the ability of captive female African elephants to discern between the follicular and luteal phase of conspecifics through trunk-tip contacts and the investigation of urine, and whether the reproductive phase of the receiver affected the response to urine. For the first objective, focal animal observations were made on 83 female and 81 male elephants less than 11 years of age from June-October 2005 in Addo Elephant National Park, South Africa. For the second objective, 11 estrous and 10 non-estrous females were observed at nine zoos throughout North America from March-August, 2006. Sexually dimorphic behaviors and developmental patterns conducive to future adult lifestyles became apparent during social play, social interactions, and exploratory chemosensory behaviors of young male and female elephants. Captive elephants were able to discern estrous condition through direct contact to the urogenital region, increasing in rate with approaching ovulation, however, they did not distinguish between luteal and follicular urine from unfamiliar females
Eumonhystera media n. sp. and description of the male of E. vulgaris (De Man, 1880) AndrĂĄssy, 1981 (Nematoda, Monhysteridae)
Constraining the Origin of the Jupiter Trojans by In Situ Measurement of Volatiles, Minerals, and Ices
As the KISS Trojans program comes to a close, we report here on our achievements in this venture that began with a KISS workshop in 2012, âIn Situ Science and Instrumentation for Primitive Bodiesâ. The original workshop brought together a diverse group (see Appendix B) that set out to tackle an ambitious goal â to find a way to test predictions of dynamical models (such as the Nice model, named after the founding research group in Nice, France), that have recently led to a radically new understanding of solar system formation. We aimed to do so through interdisciplinary collaboration between the planetary dynamics communities that have formulated (and largely dominated discussion of) these new ideas, and the meteoritics and cosmochemistry communities who would no doubt be involved in any in situ mission to an outer solar system body
Simplification rationnelle des outils hydrologiques de gestion : recommandations méthodologiques pour la construction de modÚles semi-empiriques à origine mécaniste
Les modĂšles de simulation hydrologiques sont reconnus comme des outils mathĂ©matiques trĂšs performants mais gĂ©nĂ©ralement d'application difficile, principalement Ă cause du nombre Ă©levĂ© des paramĂštres requis. Ă l'inverse, les outils actuels de gestion sont gĂ©nĂ©ralement dĂ©veloppĂ©s Ă l'aide d'approches empiriques limitant leur application. De plus, leurs paramĂštres ne sont pas des grandeurs mesurables et doivent ĂȘtre ajustĂ©s pour chaque situation. Une approche est proposĂ©e pour le dĂ©veloppement d'outils semi empiriques de gestion. Elle consiste Ă simuler un grand nombre de scĂ©narios en utilisant un modĂšle complexe de simulation puis Ă rationaliser l'information obtenue pour dĂ©velopper un nouveau modĂšle semi empirique. L'exemple illustrant cette approche concerne l'Ă©valuation des flux d'eau ruisselĂ©e Ă la surface des champs, lessivĂ©e vers la nappe souterraine et drainĂ©e par les drains agricoles spĂ©cifiquement pour le contexte du QuĂ©bec. Ă partir des rĂ©sultats de simulation de 4500 scĂ©narios, une simplification.rationalisation a permis de rĂ©duire Ă 120 le nombre de scĂ©narios de rĂ©fĂ©rence Ă l'aide desquels peuvent ĂȘtre Ă©valuĂ©s tous les scĂ©narios possibles par de simples interpolations linĂ©aires. Une application de l'algorithme rĂ©sultant sur un site du QuĂ©bec a montrĂ© la bonne concordance entre les rĂ©sultats calculĂ©s et mesurĂ©s. Ă la fois l'ordre de grandeur du ruissellement et du drainage et leur grandeur relative sont bien Ă©valuĂ©s.Considering the complexity of the water cycle in soil systems, models are used more than ever in parallel with field investigations to assist in the decision making process (KHAKURAL et ROBERT, 1993). Most available models are either too complicated (many non-measurable parameters) or too simple (empirical or site-specific) to be used as management tools. Such tools should conform to known theory and should be structured to enable efficient analysis of field situations with minimal requirements for parameters (CARSEL et al 1984). However, if the mechanistic models are very performing tools with regards to their representation of the processes and for the accuracy and reliability of their results, they are criticized for their complexity and for the large number of parameters they require. For this reason, their potential application as management tools cannot be recommended especially in preliminary investigations when the methodology has to be straight forward and rapidly implemented. On the other hand, existing management tools are often developed using an empirical approach for a specific context which considerably limits their transferability to different situations. Moreover, their empirical parameters often cannot be measured for the new situations, and must be adjusted for each new application. A new approach conciliating the qualities of both kinds of tools was elaborated for the development of management tools. This approach consists in using mechanistic models for simulating a set of possible situations and in rationalizing the information obtained by simulation through regression analyses or other methods. An example of this methodology is presented in this paper with the development of the hydrological part (runoff, leaching and drainage) of a management tool dedicated to the evaluation of nutrient losses related to manure applications. Developed for the Quebec conditions, 4500 theoretical situations were considered corresponding to ten climates, nine soil textures, 25 crops and two slope values. Independently, agricultural management practices and drainage were taken into account.For the mechanistic simulation of the water budget in the 4500 theoretical situations, the hydrologic module of the mechanistic-stochastic model AgriFlux was used (BANTON et al. 1993b). Because of the important field variability of most parameters, the stochastic AgriFlux model incorporates the variability resulting from field heterogeneity, measurement errors and intrinsic uncertainty related to parameter definition. The soil profile is divided in plot scale homogeneous horizons (or compartments) and a daily time step is used in the calculations. The water budget module in AgriFlux is named HydriFlux and simulates all the water-related processes (precipitations, snowmelt, infiltration, runoff, water uptake by plants, evaporation, percolation and drainage) using characteristic water contents and unsaturated hydraulic conductivity.In the example presented, the simulation results obtained by running HydriFlux have shown that the soil water fluxes (runoff and percolation) vary as linear functions of both the annual rain volume (the most important characteristic of the climate) and the logarithm of the saturated hydraulic conductivity (the most important characteristic of the soil type). A reduction of the number of crops could also be achieved by taking into account the water needs and the water uptake curves of the crops. This rationalization-simplification reduced the number of theoretical simulations to be stored in the management tool to 120 (2 climates x 3 textures x 10 crops x 2 slopes). These represent only 2.7% of the initial situations simulated by the mechanistic HydriFlux model. The different water fluxes are stored in the management tool as tables in which direct interpolations are performed to calculate the fluxes corresponding to all the potential intermediary situations. Such developed management tool presents good qualities at the same time for its calculation speed, for its easy parameterization, for the reliability of its evaluation (through the evaluation of the mechanistic model) and for its high transferability and applicability to various situations. The calculations are rapidly done and their programming can be very easily made by using a spreadsheet software.An application of this evaluation method has been done on an experimental site located in Quebec (ENRIGHT et MADRAMOOTOO, 1994), the only one for which both the runoff and the drainage have been measured during many years (1989 to 1991, April to December). The application on two fields (1.84 et 4.63 ha) has shown a good concordance between the calculated and measured results, as well for the magnitude of the fluxes than for the relative importance of these fluxes. Moreover, this application has shown that the variability of the measured values is higher than the calculated ones, attesting of the great influence of the variations in climatic, soil, crop and management conditions on the water budget. However, the good evaluation of the fluxes (for relative and absolute values) confirms the reliability of the proposed approach and of the simplification
Rabies Surveillance Identifies Potential Risk Corridors and Enables Management Evaluation
Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV management strategies, and identify surveillance gaps. ORV management has resulted in a decrease in RABV cases over time within vaccination zones (from occupancy (Ï) of 0.60 standard error (SE) = 0.03 in the spring of 2006 to Ï of 0.33 SE = 0.10 in the spring 2017). RABV cases also reduced in the enzootic area (from Ï of 0.60 SE = 0.03 in the spring of 2006 to Ï of 0.45 SE = 0.05 in the spring 2017). Although RABV occurrence was related to habitat type, greater impacts were associated with ORV and trapâvaccinateârelease (TVR) campaigns, in addition to seasonal and yearly trends. Reductions in RABV occupancy were more pronounced in areas treated with Ontario Rabies Vaccine Bait (ONRAB) compared to RABORAL V-RGÂź. Our approach tracked changes in RABV occurrence across space and time, identified risk corridors for potential incursions into Canada, and highlighted surveillance gaps, while evaluating the impacts of management actions. Using this approach, we are able to provide guidance for future RABV management
An association analysis for 14 candidate genes mapping to meat quality quantitative trait loci in a Duroc pig population reveals that the ATP1A2 genotype is highly associated with muscle electric conductivity
In previous GWAS carried out in a Duroc commercial line (Lipgen population), we detected on pig chromosomes 3, 4 and 14 several QTL for gluteus medius muscle redness (GM a*), electric conductivity in the longissimus dorsi muscle (LD CE) and vaccenic acid content in the LD muscle (LD C18:1 n â 7), respectively. We have genotyped, in the Lipgen population, 19 SNPs mapping to 14 genes located within these QTL. Subsequently, association analyses have been performed. After correction for multiple testing, two SNPs in the TGFBRAP1 (rs321173745) and SELENOI (rs330820437) genes were associated with GM a*, whereas ACADSB (rs81449951) and GPR26 (rs343087568) genotypes displayed significant associations with LD vaccenic content. Moreover, the polymorphisms located at the ATP1A2 (rs344748241), ATP8B2 (rs81382410) and CREB3L4 (rs321278469 and rs330133789) genes showed significant associations with LD CE. We made a second round of association analyses including the SNPs mentioned above as well as other SNPs located in the chromosomes to which they map. After performing a correction for multiple testing, the only association that remained significant at the chromosomeâwide level was that between the ATP1A2 genotype and LD CE. From a functional point of view, this association is meaningful because this locus encodes a subunit of the Na+/K+âATPase responsible for maintaining an electrochemical gradient across the plasma membrane.info:eu-repo/semantics/acceptedVersio
- âŠ