Homology and modular classes of Lie algebroids

For a Lie algebroid, divergences chosen in a classical way lead to a uniquely defined homology theory. They define also, in a natural way, modular classes of certain Lie algebroid morphisms. This approach, applied for the anchor map, recovers the concept of modular class due to S. Evans, J.-H. Lu, and A. Weinstein.Comment: 11 pages, AmSLaTeX, 3 typos correcte

Nigrostriatal interaction in the aging brain: new therapeutic target for Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder of unclear etiology and pathogenesis. Research results gathered to date support the hypothesis that the motor symptoms of the disease result from the gradual loss of midbrain dopamine neurons residing in the substantia nigra pars compacta (SNpc). Recent discoveries, however, significantly expand this knowledge indicating that the primary source of the PD pathogenesis may be located both in the SNpc as well as in the GABAergic striatum. Newly discovered striatal neurogenesis – normally a lifelong process – determines the efficiency of nigrostriatal interaction. Deficient neurogenesis within the striatum followed by a decline in the GABAergic/dopaminergic interaction results in progressive disconnection of the dopaminergic input, which initiates a 'vicious circle' cascade of neuronal damage. Effects of both deficient striatal neurogenesis and age‑related neurodegeneration within the striatum accumulate, resulting in a progressive decline in the control functions of the basal ganglia, loss of dopaminergic neurons, and occurrence of PD clinical symptoms. Functional and pharmacological control of these dynamic relationships may result in treatments that are more effective with fewer side‑effects

Long-term changes in the statistical distribution of Dobson total ozone in selected Northern Hemisphere geographical regions

The daily averages of total column amount of ozone taken in the period 1964-1988 at a network of 24 Dobson stations have been analyzed. Year-round data as well as summer data (May - Aug.) and winter data (Dec. - March) have been examined in the following regions: latitude bands (30 deg N - 39 deg N, 40 deg N - 52 deg N, 30 deg N - 60 deg N), North America, Europe, and Japan. To find year-to-year changes in the shape of the annual statistical distribution of total ozone (ASDTO) for these regions, we analyze trends in the following statistic characteristics of ASDTO: mean, standard deviation, median, and 10 and 90 percentiles. Time series of the statistical characteristics for the selected regions have been combined by averaging the individual stations values of these characteristics. The trends have been calculated by the multiple regression model adjusted for: the 11-year solar cycle, the Southern Oscillations effects, and for serial correlations. We have found that: a) in all regions (excluding Japan, North America), the shape of ASDTO has been drifting towards low ozone values. The drift seems to be not accompanied with a transformation in the shape of ASDTO. The drift speed (the rate of decrease in the annual means of total ozone) is of order 1-3 percent per decade (in the period 1970-1988). b) In Japan, the interannual changes in the shape of ASDTO have not been revealed. c) In North America, the drift of the year-round ASDTO (the year-round ASDTO comprises all the daily means of total ozone in a given year) has been accompanied with a transformation in the shape. The shape of the year round ASDTO becomes narrower. d) In all regions, except Japan and the band 30 deg - 39 deg N, the winter ASDTO (the winter ASDTO comprises the data taken in the period December in a given year through March next year) moves faster towards low ozone values than the summer ASDTO (the summer ASDTO comprises the data taken in the period May through August in a given year)

Vectorcardiographic changes during extended space flight

To assess the effects of space flight on cardiac electrical properties, vectorcardiograms were taken on the 9 Skylab astronauts during the flights of 28, 59, and 84 days. The Frank lead system was used and observations were made at rest; during 25%, 50% and 75% of maximum exercise; during a short pulse of exercise (150 watts, 2 minutes); and after exercise. Data from 131 in-flight tests were analyzed by computer and compared to preflight and postflight values. Statistically significant increase in QRS vector magnitude (six of nine crewmen); T vector magnitude (five of nine crewmen); and resting PR interval duration (six of nine crewmen) occurred. During exercise the PR interval did not differ from preflight. Exercise heart rates inflight were the same as preflight, but increased in the immediate postflight period. With the exception of the arrhythmias, no deleterious vectorcardiographic changes were observed during the Skylab missions

The Use of Untreated Neuburg Siliceous Earth as Filler for High-Density Polyethylene

This paper reports the results of a study on twin-screw direct extrusion run at a screw speed of 120 rev/min to produce a composite pellet product which was used for an injection molding process and after that subjected to static tensile testing as well as hardness and specimen morphology examination. As filler, we used untreated Neuburg siliceous earth (NSE) marketed under trade names Silitin Z86 and Silitin V88 ranging from 10 to 60 wt% in a matrix made of high-density polyethylene (PE-HD) Hostalen GD 7255. The results demonstrate that Young‘s modulus and maximum tensile stress of the polyethylene composite with untreated Neuburg siliceous earth first decrease and then increase with increasing the filler’s content. The addition of Silitin Z86 causes an increase in tensile stress at break while the addition of Silitin V88 leads to its decrease. Strain at maximum tensile stress of the tested molded pieces first increases with increasing the filler’s content, but then starts to decrease. The tested composite molded pieces have lower strain at break as opposed to those without the filler. An increase in the filler’s content leads to an increase in hardness of the tested specimens. The results of specimen morphology demonstrate that the filler is unevenly distributed in the polymer and reveals a strong tendency to agglomerate

Optimal time of duration of a long-term video-EEG monitoring in paroxysmal events – A retrospective analysis of 282 sessions in 202 patients

Purpose To find the optimal duration of the long-term video-EEG (LTM) and assess diagnostics utility of LTM in patients with epilepsy and other paroxysmal events in terms of future diagnosis and management. Methods Retrospective analysis of 282 LTMs performed in the last 5 years in our Epilepsy Monitoring Unit (EMU), in 202 consecutive patients. The analysis included demographic data, monitoring time, number and type of paroxysmal events, the time until their onset, influence of LTM result on the diagnosis and future management. Results There were 117 women and 85 men, mean age 34.2 years. Mean duration of LTM was 5 days (3–9), with 447 paroxysmal events recorded in 131 (65%) patients. Epileptic seizures were recorded in 82% cases (in 11% associated with PNES). The remaining 18% had either PNES (psychogenic non-epileptic seizures) – 11%, or parasomnias – 7%. Only 15% of epileptic seizures took place within the first 24h of the LTM (53% and 32% on the 2nd and 3rd day, respectively), whereas as many as 62% of PNES did (while only 28% and 10% on the 2nd and 3rd day, respectively). The LTM results changed the diagnosis in 36% of the patients, most frequently in PNES (from 2% to 14%). Altogether, it changed the management in 64% of the patients – particularly with PNES and those who underwent epilepsy surgery. Conclusions LTM should last at least 72h in patients with refractory epilepsy. Most of cases with PNES could be diagnosed after 48h