oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 464 )

2018 ( 705 )

2017 ( 696 )

2016 ( 966 )

Custom range...

Search Results: 1 - 10 of 401365 matches for " Cara M Hildreth "
All listed articles are free for downloading (OA Articles)
Page 1 /401365
Display every page Item
Prognostic Indicators of Cardiovascular Risk in Renal Disease
Cara M. Hildreth
Frontiers in Physiology , 2012, DOI: 10.3389/fphys.2011.00121
Abstract: Although the annual mortality rate for end-stage renal disease (ESRD) is decreasing, likely due to an increase in kidney transplantation rate, the survival probability for ESRD patients from day one of dialysis has not changed, and is still poor with a 5-year survival rate of approximately 34%. This is contributed to by a high prevalence of cardiovascular disease, which is the leading cause of death in ESRD patients. In order to improve survival outcomes, patients at high risk of cardiovascular related mortality need to be identified. Heart rate variability (HRV), baroreceptor sensitivity, and baroreceptor reflex effectiveness index can be used to assess heart rate control and may predict cardiovascular mortality. This paper will discuss how HRV, baroreceptor sensitivity, and baroreceptor reflex effectiveness index are altered in renal disease and the utility of these indices as markers of cardiac risk in this patient population.
Role of ionotropic GABA, glutamate and glycine receptors in the tonic and reflex control of cardiac vagal outflow in the rat
Cara M Hildreth, Ann K Goodchild
BMC Neuroscience , 2010, DOI: 10.1186/1471-2202-11-128
Abstract: Microinjection of the GABAA antagonist picrotoxin into CVPN decreased HR but did not affect baroreflex bradycardia. The glycine antagonist strychnine did not alter HR or baroreflex bradycardia. Combined microinjection of the NMDA antagonist, MK801, and AMPA antagonist, CNQX, into CVPN evoked a small bradycardia and abolished baroreflex bradycardia. MK801 attenuated whereas CNQX abolished baroreceptor bradycardia. Control intravenous injections of the 5-HT1A agonist 8-OH-DPAT evoked a small bradycardia and potentiated baroreflex bradycardia. These effects were still observed following microinjection of picrotoxin but not strychnine into CVPN.We conclude that activation of GABAA receptors set the level of HR whereas AMPA to a greater extent than NMDA receptors elicit baroreflex changes in HR. Furthermore, activation of 5-HT1A receptors evokes bradycardia and enhances baroreflex changes in HR due to interactions with glycinergic neurons involving strychnine receptors. This study provides reference for future studies investigating how diseases alter neurochemical inputs to CVPN.Cardiac vagal preganglionic neurons (CVPN) are found predominantly in the nucleus ambiguus (NA) as well as dorsal motor nucleus of the vagus (DMNV) and in the intermediate zone (IZ) between these two nuclei [1-3]. Activation of CVPN has negative chronotropic, dromotropic and ionotropic effects on the heart [4-6] and the activity of these neurons is increased in response to baroreceptor stimulation [7-9] and inhibited during inspiration [10,11].Surprisingly little is known about the functional significance of inputs to CVPN mediated by either ionotropic or g-protein coupled receptors (GPCR). CVPN receive substantial inputs from ionotropic receptors. Microinjection of the GABAA receptor antagonist bicuculline into the NA evokes a profound decrease in HR [12] demonstrating that there is a large GABAergic input to CVPN that plays a role in setting the tonic level of heart rate (HR). GABAergic inputs
Comment on “Quantitative Evaluation of Commercially Available Test Kit for Ciguatera in Fish”  [PDF]
Joanne S. M. Ebesu, Cara E. Campora
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.39162
Abstract: This letter is in regards to the paper, “Quantitative evaluation of commercially available test kit for ciguatera in fish” [1]. We were compelled to respond because the entire premise of this paper is flawed, thus invalidating its stated conclusions. The data presented in the paper is derived from the opinions of four independent readers who evaluated identical Cigua-Check? test sticks to screen fish samples for ciguatoxin (CTX), the results of which were then compared with corresponding samples tested in a non-specific bioassay with questionable statistics (see Table 1 [1]). In addition to several factual errors presented in the paper, we have identified several issues with this study, such as insufficient detail and questionable data analyses, that make its interpretations unreliable.
The forgotten resource: Community perspectives on conservation and well-being in Zahamena National Park, Madagascar
Cara M. Raboanarielina
Madagascar Conservation & Development , 2012,
Abstract: This research examines local perceptions of social well-being in two forest-dependent communities near Zahamena National Park (ZNP), Madagascar. Key informant interviews were conducted to observe how local context, including community and ecological factors, influenced perceptions of social well-being. Overall, residents expressed a broad sense of decreased well-being as local forest resource access changed following the creation of ZNP. While one community was more dependent on forest and non-timber forest products for their livelihood, both communities believed lack of access to the park and its resources negatively affected local social well-being. Further, both communities felt ZNP provided few benefits to local residents. In addition, informants alluded to a sense of distrust of conservation managers and believed their needs and concerns were neither heard nor addressed by current conservation programs. Such data confirm people living in rural communities adjacent to protected areas have limited impact on conservation policies and initiatives on the island. Implications of this research suggest a reassessment of institutional conservation policy and practices to reflect locally held social traditions and community beliefs about conservation. RésuméCette étude examine les perceptions locales de la qualité de vie dans deux communautés dépendantes de la forêt et vivant à proximité du Parc National de Zahamena à Madagascar. Des entretiens ont été menés pour analyser comment le contexte local, tant au niveau des facteurs communautaires qu’écologiques, a influencé les perceptions portant sur la qualité de vie. En général, les résidents ont constaté une baisse de leur qualité de vie depuis la création du Parc à cause du changement d'accès aux ressources forestières locales. Une des communautés dépendait des produits forestiers ligneux et non ligneux pour sa subsistance et une autre communauté a estimé que le fait de ne pouvoir accéder au Parc et à ses ressources avait détérioré son niveau de vie. En outre, les deux communautés ont considéré que le Parc avait fourni peu d’avantages aux résidents. Les personnes interviewées ont également exprimé une certaine méfiance à l’égard des gestionnaires du programme de conservation qui, selon elles, n’ont répondu ni à leurs besoins ni à leurs préoccupations. Ces résultats confirment que les communautés rurales vivant à proximité des aires protégées ont une influence limitée sur la politique et les initiatives de conservation à Madagascar. Cette recherche suggère que la politique de conservation doit être réévaluée e
Size and Shape: Morphology's Impact on Human Speed and Mobility
Cara M. Wall-Scheffler
Journal of Anthropology , 2012, DOI: 10.1155/2012/340493
Abstract: While human sexual dimorphism is generally expected to be the result of differential reproductive strategies, it has the potential to create differences in the energetics of locomotion and the speed at which each morph travels, particularly since people have been shown to choose walking speeds around their metabolic optimum. Here, people of varying sizes walked around a track at four self-selected speeds while their metabolic rate was collected, in order to test whether the size variation within a population could significantly affect the shape of the optimal walking curve. The data show that larger people have significantly faster optimal walking speeds, higher costs at their optimal speed, and a more acute optimal walking curve (thus an increased penalty for walking at suboptimal speeds). Bigger people who also have wider bitrochanteric breadths have lower metabolic costs at their minimum than bigger people with a more narrow bitrochanteric breadth. Finally, tibia length significantly positively predicts optimal walking speed. These results suggest sex-specific walking groups typical of living human populations may be the result of energy maximizing strategies. In addition, testable hypotheses of group strategies are put forth.
Size and Shape: Morphology's Impact on Human Speed and Mobility
Cara M. Wall-Scheffler
Journal of Anthropology , 2012, DOI: 10.1155/2012/340493
Abstract: While human sexual dimorphism is generally expected to be the result of differential reproductive strategies, it has the potential to create differences in the energetics of locomotion and the speed at which each morph travels, particularly since people have been shown to choose walking speeds around their metabolic optimum. Here, people of varying sizes walked around a track at four self-selected speeds while their metabolic rate was collected, in order to test whether the size variation within a population could significantly affect the shape of the optimal walking curve. The data show that larger people have significantly faster optimal walking speeds, higher costs at their optimal speed, and a more acute optimal walking curve (thus an increased penalty for walking at suboptimal speeds). Bigger people who also have wider bitrochanteric breadths have lower metabolic costs at their minimum than bigger people with a more narrow bitrochanteric breadth. Finally, tibia length significantly positively predicts optimal walking speed. These results suggest sex-specific walking groups typical of living human populations may be the result of energy maximizing strategies. In addition, testable hypotheses of group strategies are put forth. 1. Introduction In recent years a number of key paleoanthropological finds and reconstructions have pushed into the forefront ideas of mobility strategies within and between hominin groups or species. Understanding mobility strategies is important in order to place groups within a particular adaptive environment or niche [1]. Distances traveled, time spent traveling, and group composition of a traveling party all determine the behavioral tradeoffs that provide the basis for selection pressures. For example, increasing the speed of one task, can increase the availability of time for another task (e.g., tool development [2]). Conversely, if essential foraging behavior takes up most of the day-light hours, social behaviors might suffer and group fragmentation may occur [3–5]. Studies that integrate mobility and reproductive success clearly show that the energetics of daily walking influence interbirth-intervals and offspring survivorship [6–9]. Studies that applied meta-analyses of ongoing selection in human populations further show a close relationship between locomotor morphology and reproductive success [10] and locomotor stress and drops in ovarian hormones [11]. Furthermore, changes in mobility have consistently been shown to influence weight loss/weight gain, and ovarian function and fecundity have consistently been shown to
Loss of Niemann Pick type C proteins 1 and 2 greatly enhances HIV infectivity and is associated with accumulation of HIV Gag and cholesterol in late endosomes/lysosomes
Ebony M Coleman, Tiffany N Walker, James EK Hildreth
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-31
Abstract: We used a unique NPC2-deficient cell line (NPCD55) that exhibited Gag accumulation as well as decreased NPC1 expression after HIV infection. Virus release efficiency from NPCD55 cells was similar to that from control cells. However, we observed a 3 to 4-fold enhancement in the infectivity of virus released from these cells. Fluorescence microscopy revealed accumulation and co-localization of Gag proteins with cholesterol in late endosomal/lysosomal (LE/L) compartments of these cells. Virion-associated cholesterol was 4-fold higher in virions produced in NPCD55 cells relative to virus produced in control cells. Treatment of infected NPCD55 cells with the cholesterol efflux-inducing drug TO-9013171 reduced virus infectivity to control levels.These results suggest cholesterol trafficking and localization can profoundly affect HIV-1 infectivity by modulating the cholesterol content of the virions.Cellular cholesterol plays a critical role in various stages of the HIV-1 replication cycle. HIV-1 fusion, entry, assembly, and budding occur at cholesterol-enriched microdomains called lipid rafts [1-4]. The HIV-1 accessory protein, Nef, has been shown to induce many genes involved in cholesterol biosynthesis and homeostasis [5,6]. Depletion of virion-associated cholesterol by beta-cyclodextrin compromises viral structural integrity and significantly decreases both the quantity and infectivity of virions released from infected cells [7,8]. Treatment of HIV particles with cholesterol-sequestering compounds inhibits virus entry into host cells [9,10].Previous studies have shown that Nef inhibits the activity of ATP-binding cassette transporter A1 (ABCA1) in HIV-infected macrophages. The inhibition of ABCA1 leads to suppression of cholesterol efflux and an accumulation of intracellular cholesterol [11]. In turn, this effect increases the cholesterol content of the virions. The proteins implicated in Niemann-Pick Type C (NPC) disease, NPC1 and NPC2, are responsible for the egress
Energetic Consequences of Human Sociality: Walking Speed Choices among Friendly Dyads
Janelle Wagnild, Cara M. Wall-Scheffler
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0076576
Abstract: Research has shown that individuals have an optimal walking speed–a speed which minimizes energy expenditure for a given distance. Because the optimal walking speed varies with mass and lower limb length, it also varies with sex, with males in any given population tending to have faster optimal walking speeds. This potentially creates an energetic dilemma for mixed-sex walking groups. Here we examine speed choices made by individuals of varying stature, mass, and sex walking together. Individuals (N = 22) walked around a track alone, with a significant other (with and without holding hands), and with friends of the same and opposite sex while their speeds were recorded every 100 m. Our findings show that males walk at a significantly slower pace to match the females’ paces (p = 0.009), when the female is their romantic partner. The paces of friends of either same or mixed sex walking together did not significantly change (p>0.05). Thus significant pace adjustment appears to be limited to romantic partners. These findings have implications for both mobility and reproductive strategies of groups. Because the male carries the energetic burden by adjusting his pace (slowing down 7%), the female is spared the potentially increased caloric cost required to walk together. In energetically demanding environments, we will expect to find gender segregation in group composition, particularly when travelling longer distances.
Charge Influence On Mini Black Hole's Cross Section
R. S. Cara?a,M. Malheiro
Physics , 2010, DOI: 10.1142/S0218271810017731
Abstract: In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the {\it fat brane} approximation in the context of the ADD model. The maximum charge-mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light ions but can be important for heavy ions.
Influence of external information in the minority game
M. A. R. de Cara,F. Guinea
Physics , 2003, DOI: 10.1103/PhysRevE.68.066108
Abstract: The influence of a fixed number of agents with the same fixed behavior on the dynamics of the minority game is studied. Alternatively, the system studied can be considered the minority game with a change in the comfort threshold away from half filling. Agents in the frustrated, non ergodic phase tend to overreact to the information provided by the fixed agents, leading not only to large fluctuations, but to deviations of the average occupancies from their optimal values. Agents which discount their impact on the market, or which use individual strategies reach equilibrium states, which, unlike in the absence of the external information provided by the fixed agents, do not give the highest payoff to the collective.
Page 1 /401365
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.