697 research outputs found
Evolving small spiking neural networks to work as state machines for temporal pattern recognition
Peer reviewe
Long QT: Good, bad or indifferent?
A survey of current literature suggests an increasing interest in both the desirable and undesirable implications of a prolonged QT interval, the former perceived to be the beneficial effect of antiarrhythmic drugs that prolong the duration of ventricular action potential, and the latter considered to be a potential marker for sudden cardiac death in patients with ischemic heart disease. In addition, there has been an increasing interest in the congenital long QT syndrome associated with an apparent dysfunction of the autonomic nervous system and serious, potentially lethal ventricular arrhythmias. Circumstantial evidence suggests that these arrhythmias are due to increased dispersion of repolarization which may be aggravated by psychologic and emotional perturbations.In this review, the associations between the long QT interval, autonomic nervous system, dispersion of repolarization, antiarrhythmic drugs and ventricular arrhythmias are examined. Attention is directed to the difficulties of accurate QT measurement, problems related to the correction of the QT interval for heart rate and sex (QTC), the wide range of normal values and the modest QT alterations after various manipulations of the autonomic nervous system. Clinical conditions as- sociated with marked, moderate and occasional QT lengthening are listed and discussed briefly in relation to the disturbances of nervous system, dispersion of ventricular repolarization and ventricular arrhythmias.It is proposed that the absence of relevant animal models of neurogenic or psychogenic QT prolongation hinders the investigation of the neurogenic factors associated with QT lengthening. QT prolongation is most often induced by antiarrhythmic drugs and ischemic heart disease. However, it is not known whether the occurrence of torsade de pointes type of ventricular tachycardia in patients treated with antiarrhythmic drugs is related to a critical drug dose or a critical degree of QTC prolongation. There is no conclusive evidence that QT lengthening has any predictive value either during the acute phase or during convalescence after myocardial infarction. Also, a serious deficiency in current knowledge is the lack of an established relation between the prolonged QT interval and the dispersion of ventricular repolarization. It is concluded that the number of unanswered questions discussed in this review still makes it difficult to judge when a prolonged QT interval is good, bad or indifferent
Performance of crossbreds of Polish Merino dams with F1 rams: Finnsheep x Polish Merino. C. Preliminary results of reproductive performance of ewes
The investigations were carried out on the basis of the first three reproductive cycles of ewes born in the same year. The experimental flock consisted of 100 ewes progeny of Polish Merino (PM) dams and F1 rams: Finnsheep (F) x PM; there were also 32 purebred PM used as controls. The crossbred ewes, with 25 % of F genotype, had a much better reproductive performance (117 % vs. 96 % in the PM), mainly due to a much higher prolificacy (152.2 vs. 133.6 %) and improved fertility (by 3.1 %) and the percentage of lambs weaned (higher in the crossbreds by 3.4 %)
Performance of crossbreds of Polish Merino dams with F1 rams: Finnsheep X Polish Merino. A. Semi-intensive fattening of ram-lambs up to 40—45 kg
The investigations were carried out to evaluate fattening ability, carcass quality and wool production of semi-intensively fattened ram lambs the progeny of F1 rams: Finnsheep (F) x Polish Merino (PM) mated to PM ewes. Two experiments were performed, on a total of 73 crossbreds and 73 purebred PM lambs. The lambs were housed together in a shed and fed farm-produced roughages, supplemented by commercially available concentrates. The crossbred lambs under semi-intensive feeding were found to have similar fattening ability as the purebreds: daily gains F x PM x PM 196 g and PM 191 g, energy consumption per 1 kg of body weight gain 26.1 and 27.0MJ, respectively. Crossbreeding did not affect slaughter value, but the commercial evaluation of live lambs was poorer in the crossbred groups. The tested crossbreds had generally better wool performance: their clean fleece weight was 1.09 kg, while that of the purebreds was 0.98 kg, rendement respectively 59.3 and 53.0 %, fibre length 6.7 and 5.4 cm, while fibre diameter was similar in the both groups
Performance of crossbreds of Polish Merino dams with F1 rams: Finnsheep x Polish Merino. B. Wool production of ewes
The investigations were carried out on wool of 180 non-selected ewes with 25 % Finnsheep (F) genotype (F x PM x PM) and 51 purebred Polish Merino (PM) ewes as controls. The shearing took place at 23 months of age, after a year’s growth of fleece. Greasy and clean wool production, length and diameter of fibres as well as wool character evaluated by subjective appraisal were recorded. Crossbred ewes had a slightly lower greasy wool production (F x PM x PM—4.0 kg, PM—4.3 kg), but a much higher rendement (60.2 and 51.2 % resp.) and a little higher clean wool yield 2.38 versus 2.20 kg. Wool of the crossbreds was longer (11.4 vs 10.5cm) and coarser (24.8 vs 23.9 pm), but had a poorer character 14.9 vs 16.0 points
The CHESS spectral survey of star forming regions: Peering into the protostellar shock L1157-B1 - II. Shock dynamics
Context. The outflow driven by the low-mass class 0 protostar L1157 is the prototype of the so-called chemically active outflows. The bright bowshock B1 in the southern outflow lobe is a privileged testbed of magneto-hydrodynamical (MHD) shock models, for which dynamical and chemical processes are strongly interdependent.
Aims. We present the first results of the unbiased spectral survey of the L1157-B1 bowshock, obtained in the framework of the key program “Chemical HErschel Surveys of star forming regions” (CHESS). The main aim is to trace the warm and chemically enriched gas and to infer the excitation conditions in the shock region.
Methods. The CO 5-4 and o-H2_O 1_(10)–1_(01) lines have been detected at high-spectral resolution in the unbiased spectral survey of the HIFI-band 1b spectral window (555–636 GHz), presented by Codella et al. in this volume. Complementary ground-based observations in the submm window help establish the origin of the emission detected in the main-beam of HIFI and the physical conditions in the shock.
Results. Both lines exhibit broad wings, which extend to velocities much higher than reported up to now. We find that the molecular emission arises from two regions with distinct physical conditions : an extended, warm (100 K), dense (3 × 10^5 cm^(-3)) component at low-velocity, which dominates the water line flux in Band 1; a secondary component in a small region of B1 (a few arcsec) associated with high-velocity, hot (>400 K) gas of moderate density ((1.0–3.0) × 10^4 cm^(-3)), which appears to dominate the flux of the water line at 179μm observed with PACS. The water abundance is enhanced by two orders of magnitude between the low- and the high-velocity component, from 8 × 10^(-7) up to 8 × 10^(-5). The properties of the high-velocity component agree well with the predictions of steady-state C-shock models
СТИЛІСТИЧНИЙ АНАЛІЗ СЛЕНГОВОЇ ЛЕКСИКИ СУЧАСНИХ АМЕРИКАНСЬКИХ СТУДЕНТІВ
Тези присвячено дослідженню вживання сленговых одиниць, виявлених в романі Сесилі фон Зігесар «Gossip Girl. You know you love me. All I want is everything}}, сучасними американськими студентами. Запропоновано аналіз стильових особливостей мови підлітків на граматичному, синтаксичному та лексичному рівнях, зосереджуючи увагу на лексико-стилістичних прийомах, здійснено спробу опису характерних ознак функціонування сленгу.
(The theses are devoted to the research on the use of slang units, discovered in Cecily von Ziegesar's novel «Gossip Girl. You know you love me. All I want is everything}}, by modern American students. It was propounded the analysis ofstylistic peculiarities of youth discourse on grammatical, syntactic and lexical levels, paying attention to lexico-stylistic devices, the functional peculiarities are concerned.
Biodiversity of the proposed landscape reserve of local importance "Obrichky" (Manevichsky district, Volyn region)
Досліджено природні особливості території Черевахського лісництва кв.12-14 державного підприємства «Маневицький лісгосп». Показано, що найбільшу фітосозологічну цінність пропонованої для заповідання території становить Picea abies на південній межі ареалу, яка має природне походження і місцями утворює унікальні острівні автохтонні ялинники. З ялинниками пов'язаний рідкісний вид, занесений до «Червоної книги України» - Lycopodium annotinum. Виявлено рідкісний вид Platanthera bifolia, регіонально рідкісний Rhynchospora alba та пропонований до охорони Sarolhamnus scoparius. На досліджуваній території зустрічаються рідкісні види тварин – Ciconia nigra, Milvus milvus, Tetrao tetrix, Tetrao urogallus, Grus grus та Lutra lutra. Лише в автохтонних ялинниках гніздяться в Українському Поліссі такі види птахів, як Milvus milvus, Loxia curvirostra, Regulus regulus; тут зустрічаються регіонально рідкісні види: Camponotus heiculeanus та Gaurotites wasastjernai. Науково обґрунтовано необхідність створення на даній території ландшафтного заказника місцевого значення «Обрічки».Роботу виконано на кафедрах ботаніки та зоології СНУ імені Лесі Українки
Dust Distribution during Reionization
The dust produced by the first generation of stars will be a foreground to
cosmic microwave background. In order to evaluate the effect of this early
dust, we calculate the power spectrum of the dust emission anisotropies and
compare it with the sensitivity limit of the Planck satellite. The spatial
distribution of the dust is estimated through the distribution of dark matter.
At small angular scales () the dust signal is found to be
noticeable with the Planck detector for certain values of dust lifetime and
production rates. The dust signal is also compared to sensitivities of other
instruments. The early dust emission anisotropies are finally compared to those
of local dust and they are found to be similar in magnitude at mm wavelengths.Comment: 6 pages, 6 figures; Typos fixed. Clarifications in the abstract,
sections 2 and 4.1 and fig
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