53 research outputs found

    Characterizing Stomatin-like Protein 2 and its Role in Neuron Survival

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    Stomatin-like Protein 2 (SLP-2) has been identified as a stress-inducible transcript and has been shown to interact with and stabilize mitochondrial proteins. Since mitochondria are critical for neuronal function, we hypothesized that SLP-2 regulates neuron survival in response to stressful stimuli. A conditional SLP-2 knockout mouse (deletion) and the SN56 cell line (upregulation) were employed to study the role of SLP-2 in mitochondrial dynamics and neuron survival. SLP-2 deficient primary cortical neurons displayed significantly decreased levels of various mitochondrial respiratory chain proteins, indicating SLP-2 contributes to maintenance of mitochondrial membrane integrity. SLP-2 was up-regulated in response to oxidative stress and DNA damage, but was not required for stress-induced mitochondrial biogenesis. The level of SLP-2 expression had a significantly different effect on neuron survival, depending on the target of the insult. The results of this study improve our understanding of the role of SLP-2 in mitochondrial stress responses, bioenergetics, and survival in neurons

    Kinematic characteristics of hailstorms in Northern Greece

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    International audienceThe purpose of this study is the analysis of radar data, digitally recorded, during an operational hail suppression program in the region of Central Macedonia, Greece, for the warm period of the years 1997?2001. Kinematic characteristics, such as lifetime and distance traveled by hailstorms, as well as direction of motion and speed, have been related to type of storms and season. It has been found that singlecells are short-lived and travel short distances, while multicells are long-lived and travel long distances. On the contrary, their corresponding speed distributions are similar. The deviation of the direction of motion from mean wind is smaller for singlecells than for multicells. September and July exhibit the maximum and minimum average storm speeds as a direct implication of synoptic disturbances passage and convection, prevailing respectively. Finally, storms overcoming orographic barriers decelerate in general on the windward side and accelerate on the lee side of mountains

    Effect of amlodipine, atenolol and their combination on myocardial ischemia during treadmill exercise and ambulatory monitoring

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    Objectives.This study compared the effects of amlodipine, atenolol and their combination on ischemia during treadmill testing and 48-h ambulatory monitoring.Background.It is not known whether anti-ischemic drugs exert similar effects on ischemia during ambulatory monitoring and exercise treadmill testing.Methods.Patients with stable coronary artery disease and ischemia during treadmill testing and ambulatory monitoring were randomized to receive amlodipine (n = 51) or atenolol (n = 49). Each group underwent a counterbalanced, crossover evaluation of single drug and placebo, followed by evaluation of the combination.Results.Amlodipine and the combination prolonged exercise time to 0.1-mV ST segment depression by 29% and 34%, respectively (p < 0.001) versus 3% for atenolol (p = NS). During ambulatory monitoring, the frequency of ischemic episodes decreased by 28% with amlodipine (p = 0.083 [NS]), by 57% with atenolol (p < 0.001) and by 72% with the combination (p < 0.05 vs. both single drugs; p < 0.001 vs. placebo). Suppression of ischemia during exercise testing and ambulatory monitoring was similar in patients with and without exercise-induced angina. Exercise time to angina improved by 29% with amlodipine (p < 0.01), by 16% with atenolol (p < 0.05) and by 39% with the combination (p < 0.005 vs. placebo, atenolol and amlodipine). In patients with angina, total exercise time improved by 16% with amlodipine (p < 0.001), by 4% with atenolol (p = NS) and by 19% with the combination (p < 0.05 vs. placebo and either single drug). In those patients without angina, no therapy significantly improved total exercise time.Conclusions.Ischemia during treadmill testing was more effectively suppressed by amlodipine, whereas ischemia during ambulatory monitoring was more effectively suppressed by atenolol. The combination was more effective than either single drug in both settings

    Competition Strategies of Metritic and Healthy Transition Cows

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    Our study aimed to characterize social competition strategies in transition cows, and determine how these varied with health status. We retrospectively followed 52 cows during 3 periods (PRE: d −6 to −1 prepartum, POST1: d 1 to 3 postpartum, POST2: d 4 to 6 postpartum). Cows diagnosed with metritis on d 6 postpartum (n = 26) were match paired with healthy cows (n = 26). Measures of agonistic behavior (i.e., replacements at the feeder) and feeding synchrony were determined by an algorithm based on electronic feed bin data, and used to calculate competition strategies via principal component analysis. We found consistent strategies, defined by two components (asynchrony and competitiveness; explaining 82% of the total variance). We observed no differences in strategies when comparing healthy and metritic cows, but metritic cows tended to change their strategies more between PRE and POST1, and between POST1 and POST2, indicating that strategies change in association with parturition and metritis. We conclude that cows show individual variation in competition strategies, and that automated measures of strategy change may help in detecting metritis.Land and Food Systems, Faculty ofOther UBCReviewedFacult

    Fog characteristics at the airport of Thessaloniki, Greece

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    A statistical approach in order to study fog event characteristics occuring at the airport of Thessaloniki, Northern Greece is presented in this work. To achieve this, the seasonal and diurnal characteristics of fog are investigated using 35 years (1971–2005) of observations of meteorological parameters such as: visibility, air temperature, dew point temperature, air relative humidity, wind vector, precipitation, and cloud base height and coverage. Hourly surface observations of fifteen (15) years (1991–2005) are used to identify fog events induced by various physical mechanisms. Fog events are classified into fog types through the application of objective criteria that are derived upon fog formation processes and under the influence of various physiographic features. The temporal variability of different fog type occurrences are examined and the events are characterized according to their duration and intensity. &lt;br&gt;&lt;br&gt; The results are somehow affected by regional and local factors. Fog is mainly formed in winter time (~64%) with an enhanced likelihood to appear also in late autumn (19%). The highest frequency of the fog events occurs around sunrise or 1 to 2 h before of it. The mean duration of the events is about 4.5 h. Most of them (75%) are dense (visibility &amp;lt;400 m). The overall fog phenomenon is a combination of various types, such as: advection fog, radiation fog, cloud-base lowering fog and precipitation fog. Advection fog (30%) and radiation fog (29%), which are the most common types, occur predominantly in winter and early spring time. With respect to the former type, it seems that, in many cases, already formed fog is advected from the nearby &lt;i&gt;Anthemountas&lt;/i&gt; valley. Moreover, a considerable number of fog events (22%) result from cloud-base lowering, and they frequently occur in late autumn and mid winter
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