Long Term Financial Impacts of Drought Management Strategies

This paper analyzes the financial implications of drought management strategies for a model ranch in South Texas. The 2006 drought that affected Texas livestock producers left many cattlemen asking the age old question, "Should I cull to reduce my herd size or purchase feed to maintain my current herd".Livestock Production/Industries,

Intracellular Ca2+ oscillations generated via the extracellular Ca2+-sensing receptor (CaSR) in response to extracellular Ca2+ or l-phenylalanine: Impact of the highly conservative mutation Ser170Thr

The extracellular Ca2+-sensing receptor (CaSR) is an allosteric protein that responds to changes in the extracellular concentration of Ca2+ ([Ca2+]e) and aromatic amino acids with the production of different patterns of oscillations in intracellular Ca2+ concentration ([Ca2+]i). An increase in [Ca2+]e stimulates sinusoidal oscillations in [Ca2+]i whereas aromatic amino acid-induced CaR activation in the presence of a threshold [Ca2+]e promotes transient oscillations in [Ca2+]i. Here, we examined spontaneous and ligand-evoked [Ca2+]i oscillations in single HEK-293 cells transfected with the wild type CaSR or with a mutant CaSR in which Ser170 was converted to Thr (CaSRS170T). Our analysis demonstrates that cells expressing CaSRS170T display [Ca2+]i oscillations in the presence of low concentrations of extracellular Ca2+ and respond to L-Phe with robust transient [Ca2+]i oscillations. Our results indicate that the S170T mutation induces a marked increase in CaSR sensitivity to [Ca2+]e and imply that the allosteric regulation of the CaSR by aromatic amino acids is not only mediated by an heterotropic positive effect on Ca2+ binding cooperativity but, as biased agonists, aromatic amino acids stabilize a CaSR conformation that couples to a different signaling pathway leading to transient [Ca2+]i oscillations.Fil: Young, Steven H.. University of California at Los Angeles; Estados UnidosFil: Rey, Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Rozengurt, Enrique. Veterans Affairs West Los Angeles Healthcare System; Estados Unidos. University of California at Los Angeles; Estados Unido

Experimental realization of catalytic CH_4 hydroxylation predicted for an iridium NNC pincer complex, demonstrating thermal, protic, and oxidant stability

A discrete, air, protic, and thermally stable (NNC)Ir(III) pincer complex was synthesized that catalytically activates the CH bond of methane in trifluoroacetic acid; functionalization using NaIO_4 and KIO_3 gives the oxy-ester

Variation in Ringed Seal Density and Abundance in Western Hudson Bay Estimated from Aerial Surveys, 1995 to 2013

We conducted systematic aerial surveys of ringed seals along strip transects in western Hudson Bay (WHB), Canada, in late May to early June of 1995–97, 1999, 2000, 2007–10, and 2013. The density of ringed seals hauled out on ice over the entire study area ranged from 1.22 seals/km2 in 1995, to 0.20 seals/km2 in 2013. Density estimates varied significantly over the study period and, with the exception of 2013, appeared to follow a cyclical pattern. Although density estimates also appear to follow a downward trend over time, results of multiple linear regression, weighted by survey effort, indicated no significant trend in ringed seal density as a function of year, survey date, or proportion of open water. In addition, no significant correlation was observed among any of the environmental variables and density estimates. As the proportion of seals hauled out at the time of the survey is unknown, the density estimates of WHB ringed seals presented in this study should be considered indices that might be useful to explore trends in abundance. Although our results do not indicate that a significant decline has occurred, the low density estimate in 2013 may indicate that population changes unrelated to a natural cycle are taking place. We were unable to test for direct effects of changes in food supply or predation, but polar bears, Arctic foxes, and Inuit communities in the Hudson Bay region all would be negatively affected should ringed seal populations undergo significant declines. Further monitoring and directed research are necessary to understand what mechanism may be responsible for the observed changes in ringed seal density.Nous avons fait les levés aériens systématiques de phoques annelés sur de longs transects en bandes dans l’ouest de la baie d’Hudson (OBH), au Canada, de la fin de mai au début de juin des années 1995 à 1997, 1999, 2000, 2007 à 2010 et 2013. Pendant toute la durée de l’étude, la densité de phoques annelés hissés sur la glace a varié de 1,22 phoque/km2 en 1995 à 0,20 phoque/km2 en 2013. Les estimations de densité ont varié considérablement au cours de la période visée par l’étude et, à l’exception de 2013, elles semblaient suivre un profil cyclique. Bien que les estimations de densité semblent également suivre une tendance à la baisse au fil du temps, les résultats de la régression linéaire multiple, pondérée par les levés, n’ont indiqué aucune tendance importante sur le plan de la densité de phoques annelés en fonction de l’année, de la date des levés ou de la proportion d’eaux libres. Par ailleurs, aucune corrélation importante n’a été observée pour n’importe quelle variable environnementale et n’importe quelle estimation de densité. Puisque la proportion de phoques hissés au moment des levés est inconnue, les estimations de densité de phoques annelés dans l’OBH présentées dans cette étude devraient être considérées comme des indices susceptibles d’aider à explorer les tendances en matière d’abondance. Bien que nos résultats ne laissent pas entrevoir la présence d’un déclin important, la faible estimation de densité enregistrée en 2013 pourrait indiquer qu’il se produit des changements de population et que ceux-ci ne sont pas attribuables à un cycle naturel. Nous n’avons pu examiner les effets directs des changements en matière d’approvisionnement alimentaire ou de prédation, mais les ours polaires, les renards arctiques et les communautés inuites de la région de la baie d’Hudson subiraient tous des effets négatifs si les populations de phoques annelés diminuaient considérablement. Il y a lieu de faire de la surveillance et des recherches dirigées pour comprendre à quel mécanisme les changements observés sur le plan de la densité de phoques annelés pourrait être attribuable

Global Stability of FAST TCP in Single-Link Single-Source Network

We consider a single-link single-source network with FAST TCP source, and propose a static approximation of queuing delay dynamics at the link. The static approximation turns out to be a form with network feedback delay, which enables to analyze FAST TCP reflecting the effect of network feedback delay. Based on a continuous-time dynamic model of FAST TCP, we achieve the boundedness of window size and a sufficient condition for global asymptotic stability. The simulation results illustrate the validity of the sufficient condition for global asymptotic stability

Guide to investigating business fraud

https://egrove.olemiss.edu/aicpa_guides/1354/thumbnail.jp

Global Exponential Stability of FAST TCP

We consider a single-link multi-source network with the FAST TCP sources. We propose a continuous-time dynamic model for the FAST TCP sources and a static model to describe the queuing delay behavior at the link. The proposed model turns out to be in a form revealing the network feedback delay, which allows us to analyze FAST TCP in due consideration of the network feedback delay. Based on the proposed model, we show the boundedness of both each source's congestion window and the queuing delay at the link; and the global exponential stability under a trivial condition that each source's congestion control parameter a is positive. The simulation results illustrate the validity of the proposed model and the global exponential stability of FAST TCP

Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

Unmanned aircraft (UA) represent a new capability that will provide a variety of services in the Government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized because of the lack of a common understanding of what is required to safely operate Unmanned Aircraft Systems in the National Airspace System (UAS in the NAS). The desire and ability to fly UA is of increasing urgency. The application of UA to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UA to the NAS. Existing Federal Aviation Regulations, procedures, and technologies do not allow routine UA access to the NAS. Access to the NAS is hampered by challenges such as the lack of an onboard pilot to see and avoid other aircraft; the ability of a single pilot or operator to control multiple UA; the reliance on command and control (C2) links; the altitudes, speeds, and duration at which the aircraft fly; and the wide variation in UA size and performance. NASA is working with other Government agencies to provide solutions that reduce technical barriers and make access to the NAS routine. This goal will be accomplished through system-level integration of key concepts, technologies, or procedures and through demonstrations of these integrated capabilities in an operationally relevant environment. This project provides an opportunity to transition the acquired empirical data and knowledge to the Federal Aviation Administration and other stakeholders to help them define the requirements for routine UA access to the NAS.Radio communications channels for UA are currently managed through exceptions and use either Department of Defense frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Industrial/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for safety and regularity of flight. Only recently has radiofrequency (RF) spectrum been allocated by the International Telecommunications Union specifically for commercial UA C2, LOS communication (L-Band: 960 to 1164 MHz, and C-Band: 5030 to 5091 MHz). The safe and efficient integration of UA into the NAS requires the use of protected RF spectrum allocations and a new data communications system that is both secure and scalable to accommodate the potential growth of these new aircraft. Data communications for UA-referred to as control and non-payload communications (CNPC)-will be used to exchange information between a UA and a ground station (GS) to ensure safe, reliable, and effective UA flight operation. The focus of this effort is on validating and allocating new RF spectrum and data link communications to enable civil UA integration into the NAS. Through a cost-sharing cooperative agreement with Rockwell Collins, Inc., the NASA Glenn Research Center is exploring and performing the necessary development steps to realize a prototype UA CNPC system. These activities include investigating signal waveforms and access techniques, developing representative CNPC radio hardware, and executing relevant testing and validation activities. There is no intent to manufacture the CNPC end product, rather the goals are to study, demonstrate, and validate a typical CNPC system that will allow safe and efficient communications within the L-Band and C-Band spectrum allocations. The system is addressing initial "seed" requirements from RTCA, Inc., Special Committee 203 (SC-203) and is on a path to Federal Aviation Administration certification. This report provides results from the flight testing campaign of the Rockwell Collins Generation 1 prototype radio, referred hereafter as the "radio." The radio sets operate within the 960- to 977-MHz frequency band with both air and ground radios using identical hardware. Flight tests involved one aircraft and one GS. Results include discussion of aircraft flight paths and associated radio performance

Differentiation of Patients with Balance Insufficiency (Vestibular Hypofunction) versus Normal Subjects Using a Low-Cost Small Wireless Wearable Gait Sensor

Balance disorders present a significant healthcare burden due to the potential for hospitalization or complications for the patient, especially among the elderly population when considering intangible losses such as quality of life, morbidities, and mortalities. This work is a continuation of our earlier works where we now examine feature extraction methodology on Dynamic Gait Index (DGI) tests and machine learning classifiers to differentiate patients with balance problems versus normal subjects on an expanded cohort of 60 patients. All data was obtained using our custom designed low-cost wireless gait analysis sensor (WGAS) containing a basic inertial measurement unit (IMU) worn by each subject during the DGI tests. The raw gait data is wirelessly transmitted from the WGAS for real-time gait data collection and analysis. Here we demonstrate predictive classifiers that achieve high accuracy, sensitivity, and specificity in distinguishing abnormal from normal gaits. These results show that gait data collected from our very low-cost wearable wireless gait sensor can effectively differentiate patients with balance disorders from normal subjects in real-time using various classifiers. Our ultimate goal is to be able to use a remote sensor such as the WGAS to accurately stratify an individual’s risk for falls