2,617 research outputs found
Differences of disease progression in congestive heart failure due to alcoholic as compared to idiopathic dilated cardiomyopathy
In patients with alcoholic cardiomyopathy there is evidence that mild heart failure is reversible if patients abstain from alcohol, but there is no consensus whether the disease is progressive once structural myocardial dilatation has evolved. The aim of the present study was to compare the long-term course of congestive heart failure due to alcoholic and idiopathic dilated cardiomyopathy. Of 75 patients with overt congestive heart failure, 23 had alcoholic cardiomyopathy and were compared to 52 patients with idiopathic cardiomyopathy. The mean age was 48 Ā± 12 years. Despite medical therapy, heart failure class New York Heart Association III-IV was present in 52% of patients with alcoholic and 47% of patients with idiopathic cardiomyopathy (not significant). Their mean left ventricular ejection fraction was 30 Ā± l2% vs 28 Ā± 12% and left ventricular end-diastolic volumes were 264 Ā± 125 ml and 254 Ā± 100 ml respectively (not significant). Overall survival at 1, 5 and 10 years was l00%, 81% and 81% for the group with alcoholic dilated cardiomyopathy and 89%, 48% and 30% for the group with idiopathic cardiomyopathy, respectively (P=0Ā·041 and the difference was even greater for transplant-free survival P=0Ā·005 Clinical and invasive signs of left and right heart failure as well as left ventricular dimensions were predictive of a fatal outcome; however, symptom duration and left ventricular volumes were only predictive in patients with idiopathic cardiomyopathy, suggesting that in the two patient groups different mechanisms may lead to death. Mortality in patients with severe congestive heart failure and left ventricular dilatation due to alcoholic cardiomyopathy is significantly lower than that in patients with idiopathic cardiomyopathy and similar degrees of heart failure. Thus, despite structural changes mherent in marked left ventricular dilatation, disease progression in alcoholic dilated cardiomyopathy is different from that in idiopathic cardiomyopathy and thus may have implications for the choice of therap
Can captive orangutans (Pongo pygmaeus abelii) be coaxed into cumulative build-up of techniques?
While striking cultural variation in behavior from one site to another has been described in chimpanzees and orangutans, cumulative culture might be unique to humans. Captive chimpanzees were recently found to be rather conservative, sticking to the technique they had mastered, even after more effective alternatives were demonstrated. Behavioral flexibility in problem solving, in the sense of acquiring new solutions after having learned another one earlier, is a vital prerequisite for cumulative build-up of
techniques. Here, we experimentally investigate whether captive orangutans show such flexibility, and if so, whether they show techniques that cumulatively build up (ratchet) on previous ones after conditions of the task are changed. We provided nine Sumatran orangutans (Pongo pygmaeus abelii) with two types of transparent tubes partly filled with syrup, along with potential tools such as sticks, twigs, wood wool and paper. In the first phase, the orangutans could reach inside the tubes with their hands (Regular Condition), but in the following phase, tubes had been made too narrow for their hands to fit in (Restricted Condition 1), or in addition the setup lacked their favorite materials (Restricted Condition 2). The orangutans showed high behavioral flexibility, applying nine different techniques under the regular condition in total. Individuals abandoned preferred techniques and switched to different techniques under restricted conditions when this was advantageous. We show for two of these techniques how they cumulatively built up on earlier ones. This suggests that the near-absence of cumulative culture in wild orangutans is not due to a lack of flexibility when existing solutions to tasks are made impossible
The Visual Staging of Audio Plays
The Visual Staging of Audio Plays explores the directing practice of radio dramas that are staged for viewing purposes rather than their typical solo-auditory purposes. The thesis is comprised of three separate parts: a brief history of theatrical sound, an introduction to radio drama theory and practice, and application. The application portion is a detailed first-person account of my personal experience staging Itās a Wonderful Life: A Live Radio Play by Joe Landry for TheatreVCUās Mainstage winter special event in 2015. It is also in this section where I integrate history, theory, and practice to formulate technique for directing the genre for stage
Environmental Co-Benefits of Improved Forages in Smallholder Dairy Systems of Kenya
Livestock play a major role across Kenya, especially in smallholder mixed farms through provision of household nutrition and income through milk and meat. Equally, fertilization of cropland benefits from livestock manure, and livestock often act as insurance and saving. Despite the opportunities and benefits livestock production presents, livestock systems are also key drivers of environmental degradation, including increased nutrient loads, GHG emissions, water use, grassland degradation and land-use conversion. Low livestock productivity, largely due to use of low-quality crop residues and natural grasses often not endowed with nutrients key for animal performance, limits the potential positive contributions of livestock and at the same time reduces the efficiency of natural resource use. In response to this and with smallholder dairy farmersā participation, we undertook an evaluation of 5 selected improved cultivated forages from Urochloa and Megathyrsus genus as an alternative to the Napier grass commonly grown by farmers. We evaluated impact on livestock productivity, farmersā income, land and water requirement, soil erosion, soil health and greenhouse gas emissions. We observed more efficient use of farmersā lands and financial resources through integrating improved forages and optimization of feeding strategies. We have also shown that the production and use of improved forages can act as a good climate change mitigation option
L'importance des ilĆ“ts forestiers de savane humide pour la conservation de la faune de forĆŖt dense en CĆ“te d'Ivoire
Towards a Notion of Distributed Time for Petri Nets
We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks --- possibly one per place --- allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models
Angiotensin II-receptor subtypes in human atria and evidence for alterations in patients with cardiac dysfunction
Angiotensin II (All) has been implicated as an important factor in the pathophysiology of heart diseases. Following the recent identification of two subtypes of the All receptor in cardiac tissue of animals, we investigated the possible occurrence of these, or similar, subtypes in human atrial tissue. In right-atrial tissue from patients undergoing heart surgery, we determined the All-receptor profile in receptor binding studies, using [125I]-angiotensin as radioligand and All as well as two compounds selective for the receptor subtypes to identify and quantify All-receptor subpopulations. In 35 patients (23 requiring coronary bypasses, 10 vaivular surgery and two combined coronary and valvular surgery), the left-ventricular ejection fraction was determined in the preoperative phase, and right- and left-atrial pressure during surgery. In membranes of human right atria, All receptors are present in high density (median: Bmax= 294 fmol. mgā1 protein, range: 111-2073) and two different subtypes can be distinguished. Type-1 receptors (AT1) accounted for 33 Ā± l0% of the population whereas type-2 receptors (AT2) made up 67 Ā± 10% of the population. There was no correlation between any of the measured cardiac functions and total All-receptor density or receptor affinity. However, the percentage of AT1 receptors was higher in the atria of patients with normal right-atrial pressure; left-ventricular ejection fraction was positively and right-atrial pressure inversely correlated with the percentage of AT1 receptors (r=0Ā·740 and -0Ā·901, respectively; P<0Ā·001, for both). Moreover, the percentage of AT receptors was directly correlated with the levels of left-atrial pressure (r=0Ā·853; P<0Ā·001). It is concluded that the ratio of AT1 to AT2 receptors correlates well with right-atrial pressure and left-ventricular function. This is a first indication of a possible involvement of All-receptor subtypes in the pathophysiology of cardiac dysfunction
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Gating mechanism of elongating Ī²-ketoacyl-ACP synthases.
Carbon-carbon bond forming reactions are essential transformations in natural product biosynthesis. During de novo fatty acid and polyketide biosynthesis, Ī²-ketoacyl-acyl carrier protein (ACP) synthases (KS), catalyze this process via a decarboxylative Claisen-like condensation reaction. KSs must recognize multiple chemically distinct ACPs and choreograph a ping-pong mechanism, often in an iterative fashion. Here, we report crystal structures of substrate mimetic bearing ACPs in complex with the elongating KSs from Escherichia coli, FabF and FabB, in order to better understand the stereochemical features governing substrate discrimination by KSs. Complemented by molecular dynamics (MD) simulations and mutagenesis studies, these structures reveal conformational states accessed during KS catalysis. These data taken together support a gating mechanism that regulates acyl-ACP binding and substrate delivery to the KS active site. Two active site loops undergo large conformational excursions during this dynamic gating mechanism and are likely evolutionarily conserved features in elongating KSs
Monkey see, monkey feel? Marmoset reactions towards conspecifics' arousal
Consolation has been observed in several species, including marmoset monkeys, but it is often unclear to what extent they are empathy-based. Marmosets perform well in at least two of three components of empathy-based consolation, namely understanding others and prosociality, but it is unknown to what extent they show matching with others. We, therefore, tested whether non-aroused individuals would become aroused themselves when encountering an aroused group member (indicated by piloerection of the tail). We found a robust contagion effect: group members were more likely to show piloerection themselves after having encountered an aroused versus relaxed conspecific. Moreover, group members offered consolation behaviours (affiliative approaches) towards the aroused fellow group members rather than the latter requesting it. Importantly, this pattern was shown by both aroused and non-aroused individuals, which suggests that they did not do this to reduce their own arousal but rather to console the individual in distress. We conclude that marmosets have all three components of empathy-based consolation. These results are in line with observations in another cooperative breeder, the prairie vole
Problem-solving in groups of common marmosets (Callithrix jacchus): more than the sum of its parts
Human hypercooperativity and the emergence of division of labor enables us to solve problems not only effectively within a group but also collectively. Collective problem-solving occurs when groups perform better than the additive performance of separate individuals. Currently, it is unknown whether this is unique to humans. To investigate the evolutionary origin of collective problem-solving and potential precursors, we propose a continuum of group effects on problem-solving, from simple to complex ones, eventually culminating in collective problem-solving. We tested captive common marmosets with a series of problem-solving tasks, either alone or in a group. To test whether the performance of a group was more than the sum of its parts, we compared real groups to virtual groups (pooled scores of animals tested alone). Marmosets in real groups were both more likely to solve problems than marmosets within the virtual groups and to do so faster. Although individuals within real groups approached the problem faster, a reduction in neophobia was not sufficient to explain the greater success. Success within real groups arose because animals showed higher perseverance, especially after a fellow group member had found the solution in complex tasks. These results are consistent with the idea that group problem-solving evolved alongside a continuum, with performance improving beyond baseline as societies move from social tolerance to opportunities for diffusion of information to active exchange of information. We suggest that increasing interdependence and the adoption of cooperative breeding pushed our ancestors up this scale
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