The local dust foregrounds in the microwave sky: I. Thermal emission spectra

Analyses of the cosmic microwave background (CMB) radiation maps made by the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed anomalies not predicted by the standard inflationary cosmology. In particular, the power of the quadrupole moment of the CMB fluctuations is remarkably low, and the quadrupole and octopole moments are aligned mutually and with the geometry of the Solar system. It has been suggested in the literature that microwave sky pollution by an unidentified dust cloud in the vicinity of the Solar system may be the cause for these anomalies. In this paper, we simulate the thermal emission by clouds of spherical homogeneous particles of several materials. Spectral constraints from the WMAP multi-wavelength data and earlier infrared observations on the hypothetical dust cloud are used to determine the dust cloud's physical characteristics. In order for its emissivity to demonstrate a flat, CMB-like wavelength dependence over the WMAP wavelengths (3 through 14 mm), and to be invisible in the infrared light, its particles must be macroscopic. Silicate spheres from several millimetres in size and carbonaceous particles an order of magnitude smaller will suffice. According to our estimates of the abundance of such particles in the Zodiacal cloud and trans-neptunian belt, yielding the optical depths of the order of 1E-7 for each cloud, the Solar-system dust can well contribute 10 microKelvin (within an order of magnitude) in the microwaves. This is not only intriguingly close to the magnitude of the anomalies (about 30 microKelvin), but also alarmingly above the presently believed magnitude of systematic biases of the WMAP results (below 5 microKelvin) and, to an even greater degree, of the future missions with higher sensitivities, e.g. PLANCK.Comment: 33 pages, 9 figures, 1 table. The Astrophysical Journal, 2009, accepte

Modulation of a protein free-energy landscape by circular permutation

Circular permutations usually retain the native structure and function of a protein while inevitably perturb its folding dynamics. By using simulations with a structure-based model and a rigorous methodology to determine free-energy surfaces from trajectories we evaluate the effect of a circular permutation on the free-energy landscape of the protein T4 lysozyme. We observe changes which, while subtle, largely affect the cooperativity between the two subdomains. Such a change in cooperativity has been previously experimentally observed and recently also characterized using single molecule optical tweezers and the Crooks relation. The free-energy landscapes show that both the wild type and circular permutant have an on-pathway intermediate, previously experimentally characterized, where one of the subdomains is completely formed. The landscapes, however, differ in the position of the rate-limiting step for folding, which occurs before the intermediate in the wild-type and after in the circular permutant. This shift of transition state explains the observed change in the cooperativity. The underlying free-energy landscape thus provides a microscopic description of the folding dynamics and the connection between circular permutation and the loss of cooperativity experimentally observed

A possible architecture of the planetary system HR 8799

HR8799 is a nearby A-type star with a debris disk and three planetary candidates recently imaged directly. We undertake a coherent analysis of various portions of observational data on all known components of the system. The goal is to elucidate the architecture and evolutionary status of the system. We try to further constrain the age and orientation of the system, orbits and masses of the companions, as well as the location of dust. From the high luminosity of debris dust and dynamical constraints, we argue for a rather young system's age of <50Myr. The system must be seen nearly, but not exactly, pole-on. Our analysis of the stellar rotational velocity yields an inclination of 13-30deg, whereas i>20deg is needed for the system to be dynamically stable, which suggests a probable inclination range of 20-30deg. The spectral energy distribution is naturally reproduced with two dust rings associated with two planetesimal belts. The inner "asteroid belt" is located at ~10AU inside the orbit of the innermost companion and a "Kuiper belt" at >100AU is just exterior to the orbit of the outermost companion. The dust masses in the inner and outer ring are estimated to be ~1E-05 and 4E-02 M_earth, respectively. We show that all three planetary candidates may be stable in the mass range suggested in the discovery paper by Marois et al. 2008 (between 5 and 13 Jupiter masses), but only for some of all possible orientations. Stable orbits imply a double (4:2:1) mean-motion resonance between all three companions. We finally show that in the cases where the companions themselves are orbitally stable, the dust-producing planetesimal belts are also stable against planetary perturbations.Comment: 12 pages, 14 figures, 4 tables, accepted to be published in Astronomy & Astrophysics (May 20, 2009

A peculiar class of debris disks from Herschel/DUNES - A steep fall off in the far infrared

Aims. We present photometric data of debris disks around HIP 103389 (HD 199260), HIP 107350 (HN Peg, HD206860), and HIP 114948 (HD 219482), obtained in the context of our Herschel Open Time Key Program DUNES (DUst around NEarby Stars). Methods. We used Herschel/PACS to detect the thermal emission of the three debris disks with a 3 sigma sensitivity of a few mJy at 100 um and 160 um. In addition, we obtained Herschel/PACS photometric data at 70 um for HIP 103389. Two different approaches are applied to reduce the Herschel data to investigate the impact of data reduction on the photometry. We fit analytical models to the available spectral energy distribution (SED) data. Results. The SEDs of the three disks potentially exhibit an unusually steep decrease at wavelengths > 70 um. We investigate the significance of the peculiar shape of these SEDs and the impact on models of the disks provided it is real. Our modeling reveals that such a steep decrease of the SEDs in the long wavelength regime is inconsistent with a power-law exponent of the grain size distribution -3.5 expected from a standard equilibrium collisional cascade. In contrast, a very distinct range of grain sizes is implied to dominate the thermal emission of such disks. However, we demonstrate that the understanding of the data of faint sources obtained with Herschel is still incomplete and that the significance of our results depends on the version of the data reduction pipeline used. Conclusions. A new mechanism to produce the dust in the presented debris disks, deviations from the conditions required for a standard equilibrium collisional cascade (grain size exponent of -3.5), and/or significantly different dust properties would be necessary to explain the potentially steep SED shape of the three debris disks presented. (abridged)Comment: 14 pages, 4 figures, accepted by A&

ЭКСПЕРИМЕНТАЛЬНОЕ МОДЕЛИРОВАНИЕ ПОСЛЕОПЕРАЦИОННЫХ КОГНИТИВНЫХ РАССТРОЙСТВ У КРЫС

Goal: to develop the design of the experiment for evaluation of cognitive functions and behavior of rats after some aggressive impact imitating anesthesia and surgery in the clinical practice. Methods: Male rats of Wistar stock (n = 40) were used to evaluate long-term behavioral effects of the abdomen surgery and short-term (15-20 min.) and long-term (6 hours) actions of halothane. Simple (2x2) factorial plan was used for the experiment (4 blocks, balanced as per the number of animals from 4 experimental groups, n=2 for each group in the block). For anesthesia induction 4 volumes of % halothane in the air flow (2 l/min) were used, for anesthetic support it was 1.5 volume of % halothane. During surgery the rat was placed on the heated operating table and the mask was used for anesthesia. Laparotomy was performed; empty intestine was identified and irritated for 10 seconds by massage movement of the forefinger and thumb. After that the loop was placed into the abdomen and the wound was sutured layer by layer. Then for three weeks the following behavioral tests were performed in compliance with the protocol: motor activity (Actometer) and exploratory activity in new environment (Open field), social behavior (pair interaction test), novel object recognition, extrapolational deliverance rate, forced swimming, sexual behavior. Ovariectomized female (n = 16) were used as standard opponents for social behavior tests, and hormone-stimulated female rats (n = 26) were used for sexual behavior tests. The results showed that long-term action of halothane vapor caused behavioral changes in rats: it reduces exploratory activity, decreases the novel object recognition index, increases immobility during forced swimming and reduces latent period of extrapolational deliverance. Halothane made no significant impact on motor activity (open field) and sexual behavior of male rats. In general the results of performed tests provide evidence of emotional flattening development in rats. Conclusion: It is feasible to use the experiment design and pool of behavioral tests used in this study for experimental evaluation of inhalation anesthetics effects, their late consequences, and also for searching the ways of management of the developing behavioral disorders. Цель: разработать дизайн эксперимента для оценки когнитивных функций и поведения крыс после агрессивных воздействий, имитирующих анестезию и операцию в клинической практике. Методика: с использованием самцов крыс стока Вистар (n = 40) оценивали долгосрочные поведенческие эффекты операции на органах брюшной полости и/или краткосрочного (15–20 мин) и длительного (6 ч) воздействия галотана. Использовали простой (2 × 2) факторный план эксперимента (4 блока, сбалансированные по количеству животных из 4 экспериментальных групп, n = 2 для каждой группы в блоке). Для индукции анестезии применяли 4 об. % галотана в потоке воздуха (2 л/мин), для поддержания анестезии – 1,5 об. % галотана. Для выполнения операции крысу размещали на подогреваемом операционном столике и поддерживали анестезию с помощью маски. Производили лапаратомию, выделяли тощую кишку, которую в течение 10 с раздражали массирующими движениями указательного и большого пальцев. После этого петлю опускали в брюшную полость, рану послойно ушивали. Далее в течение 3 нед. по протоколу выполняли поведенческие тесты: оценивали двигательную («Актометр») и исследовательскую активность в обстановке новизны («Открытое поле»), социальное поведение (тест парного взаимодействия), распознавание нового объекта, скорость экстраполяционного избавления, форсированное плавание, половое поведение. В качестве стандартных оппонентов в тесте социального взаимодействия использовали овариэктомированных самок крыс (n = 16), а в тесте полового поведения – гормонально стимулированных самок (n = 26). Результаты показали, что длительное воздействие паров галотана вызывает изменения поведения крыс: снижает социальное исследование, уменьшает индекс распознавания новых объектов, увеличивает неподвижность в тесте форсированного плавания и уменьшает латентный период экстраполяционного избавления. Воздействие галотана значимо не влияло на двигательную активность («открытое поле») и половое поведение самцов крыс. В целом результаты выполненных тестов свидетельствуют о развитии у крыс эмоционального уплощения вследствие длительной экспозиции галотана. Вывод. Опробованные в настоящем исследовании дизайн эксперимента и батарею поведенческих тестов целесообразно использовать для экспериментальной оценки эффектов ингаляционных анестетиков, вызываемых ими отдаленных последствий, а также для поиска средств коррекции возникающих нарушений поведения.

ПОСЛЕОПЕРАЦИОННЫЕ ИЗМЕНЕНИЯ ПОВЕДЕНИЯ КРЫС, ПОЛУЧАВШИХ АНЕСТЕЗИЮ СЕВОФЛУРАНОМ

Goal: to assess behavior and cognitive functions of rats after certain aggressive impact imitating anesthesia with sevoflurane and surgery in the clinical practice. Methods. Male rats of Wistar stock (n = 20) were used to assess the long term behavioral effect of continuous (6 hours) of action of sevoflurane and abdomen surgery. For anesthesia induction 8 volumes of % sevoflurane in the air flow (2 l/min) were used, for anesthetic support it was 4 volumes of % and 1 l/min. During surgery the rat was placed on the heated operating table and the mask was used for anesthesia; laparotomy was performed; nestis was isolated and irritated for 10 seconds by massage done by the forefinger and thumb. After that the loop was placed into the abdomen and the wound was sutured layer by layer. Then in accordance with previously compiled protocol on simulation of postoperative cognitive disorders in the rats the following behavioral tests were performed in order to evaluate the degree of post-anesthetic depression – motion and exploratory activity, social behavior, novel object recognition, specific behavior and learning under acute stress and avoidance response, forced swimming, and sexual behavior. Spray rats (n = 8) were used as standard opponents for social behavior tests, and hormone-stimulated female rats (n = 15) were used for sexual behavior tests. Results. The results showed that long-term action of sevoflurane vapor and abdomen surgery caused behavioral changes in rats compared to animals from the control group in the number of tests: they are not able to recognize novel objects and slower repeat extrapolational deliverance response in 24 hours and 7 days after its conditioning. Sevoflurane made no significant impact on motion and exploratory activities in novel circumstances, duration of immobilization during forced swimming test, social and sexual behavior of male rats. Conclusions. Continuous action of sevoflurane and abdomen surgery causes cognitive deficiency in male rats, however the profile of changes is different from the one observed under the action of halothane. Цель: оценить поведение и когнитивные функции крыс после агрессивных воздействий, имитирующих анестезию севофлураном и операцию в клинической практике. Методика. У самцов крыс стока Вистар (n = 20) оценивали долгосрочные поведенческие эффекты длительного (6 ч) воздействия севофлурана и операции на органах брюшной полости. Для индукции анестезии применяли 8 об. % севофлурана в потоке воздуха (2 л/мин), для поддержания анестезии – 4 об. % и 1 л/мин. Во время операции крысу размещали на подогреваемом операционном столике и поддерживали анестезию с помощью маски: проводили лапаротомию, выделяли тощую кишку, которую в течение 10 с раздражали массирующими движениями указательного и большого пальцев. После этого петлю опускали в брюшную полость, рану послойно ушивали. Далее в соответствии с разработанным ранее протоколом моделирования послеоперационных когнитивных расстройств у крыс выполняли ряд поведенческих тестов, оценивая степень постнаркозной депрессии, двигательную и исследовательскую активность, социальное поведение, способность распознавать новые объекты, особенности поведения и обучаемость в условиях острого стресса и воспроизведение реакции избегания, форсированное плавание и половое поведение. В качестве стандартных оппонентов в тесте «Социальное взаимодействие» использовали овариэктомированных (n = 8), а в тесте полового поведения – гормонально стимулированных (n = 15) самок крыс. Результаты. Выявлено, что поведение крыс, испытавших длительное воздействие паров севофлурана и операцию на органах брюшной полости, отличается от поведения контрольных животных в ряде тестов: не способны распознавать новые объекты и медленнее воспроизводят реакцию экстраполяционного избавления через 24 ч и 7 сут после ее выработки. Экспозиция севофлурана значимо не влияла на двигательную и исследовательскую активность в условиях новизны обстановки, длительность иммобилизации в тесте форсированного плавания, социальное и половое поведение самцов крыс. Выводы. Длительное воздействие севофлурана и операция на органах брюшной полости вызывает когнитивный дефицит у самцов крыс, однако профиль изменений отличен от наблюдаемого после воздействия галотана.

Hot exozodiacal dust resolved around Vega with IOTA/IONIC

Although debris discs have been detected around a significant number of main-sequence stars, only a few of them are known to harbour hot dust in their inner part where terrestrial planets may have formed. Thanks to infrared interferometric observations, it is possible to obtain a direct measurement of these regions, which are of prime importance for preparing future exo-Earth characterisation missions. In this context, we have resolved the exozodiacal dust disc around Vega with the help of infrared stellar interferometry and estimated the integrated H-band flux originating from the first few AUs of the debris disc. Using precise H-band interferometric measurements obtained with the 3-telescope IOTA/IONIC interferometer (Mount Hopkins, Arizona), thorough modelling of both interferometric data (squared visibility and closure phase) and spectral energy distribution was performed to constrain the nature of the near-infrared excess emission. The most straightforward scenario consists in a compact dust disc producing a thermal emission that is largely dominated by small grains located between 0.1 and 0.3 AU from Vega and accounting for 1.23 +/- 0.45% of the near-infrared stellar flux for our best-fit model. This flux ratio is shown to vary slightly with the geometry of the model used to fit our interferometric data (variations within +/-0.19%). Initially revealed by K-band CHARA/FLUOR observations, the presence of hot exozodiacal dust in the vicinity of Vega is confirmed by our H-band IOTA/IONIC measurements at the 3-sigma level. Whereas the origin of the dust is still uncertain, its presence and the possible connection with the outer disc suggest that the Vega system is currently undergoing major dynamical perturbations.Comment: 10 pages, 9 figures, accepted for publication in A&

Применение комбинации диклофенака и орфенадрина для аналгезии при эндопротезировании коленного сустава

 The objective was to assess the effectiveness and safety of the use of a fixed combination of Diclofenac and Orphenadrine (Neodolpasse) for analgesia  in patients who underwent knee replacement.Materials and methods. 40 patients who underwent knee replacement in conditions of combined spinal-conduction analgesia (femoral nerve  block) were included into the study. In the main group(n = 20), Neodolpasse (a combination of Diclofenac 75mg and of Orphenadrine 30 mg in  250 ml of solution) was administered intravenously 30 minutes before surgery, and then in the postoperative period 2 times a day for 2 days. In the  comparison group (n = 20), Ketoprofen (intravenously,100 mg) was used instead of Neodolpasse 30 minutes before surgery, in the postoperative  period, it was continued 2 times a day for 2 days (intravenously, 100 mg). The severity of the pain was assessed with a visual analog scale (VAS) 6,  12, 24 and 48 hours after surgery. The assessment of the restoration of the supporting function of the operated leg and the ability of the patient to  perform active movements in the knee joint was carried out after 24 and 48 hours. The possible side effects was assessed throughout the entire period.Results. The median value of VAS after 24 hours in the main group was 2.5 (2;3) points, which was significantly lower in compassion to VAS of the  control group 4(3;5) p = 0.006. A more pronounced analgesic effect while using Diclofenac and Orphenadrine persisted for 48 hours, the median  value of VAS in the main group after surgery was 2 (2;3), in the control group – 3 (2.8;4) p = 0.021. There were no significant differences in the  recovery time of restoration of the supporting ability of the operated leg and knee joint function, in the frequency of Tramadol use in the compared  groups. Side effects and complications were not identified.  Conclusion. The use of the fixed dose of Neodolpasse as part of multimodal perioperative analgesia in patients, who underwent knee replacement,  contributed to a decrease in the severity of pain syndrome in the postoperative period.Цель – оценить эффективность и безопасность применения фиксированной комбинации диклофенака и орфенадрина (Неодолпассе) для  обезболивания при эндопротезировании коленного сустава. Материалы и методы. В исследование включили 40 пациентов с эндопротезированием коленного сустава, выполненного в условиях  комбинированной спинально-проводниковой (блокада бедренного нерва) анестезии. В основной группе (n = 20) Неодолпассе (комбинация 75 мг диклофенака и 30 мг орфенадрина в 250 мл раствора) вводили в/в за 30 мин до начала операции, а затем в послеоперационном  периоде 2 раза в сутки в течение 2 дней. В группе сравнения (n = 20) вместо Неодолпассе за 30 мин до оперативного вмешательства использовали кетопрофен (в/в 100 мг), в послеоперационном периоде его продолжали вводить 2 раза в сутки в течение 2 дней (в/в, по 100 мг).  Выраженность болевого синдрома оценивали по визуально-аналоговой шкале (ВАШ) через 6, 12, 24 и 48 часов после операции. Оценку  восстановления опорной функции прооперированной ноги и возможности совершать пациентом активные движения в коленном суставе  осуществляли через 24 и 48 часов. Возможное развитие нежелательных эффектов прослеживали на протяжении всего периода наблюдения. Результаты. У пациентов основной группы медиана значения ВАШ через 24 часа составила 2,5 (2;3) балла и была значимо ниже, чем в  контроле (4 (3;5), р = 0,006). Более выраженный анальгетический эффект при использовании Неодолпассе сохранялся на протяжении  48 часов, медиана значения ВАШ в основной группе составила 2 (2; 3), в контрольной – 3 (2,8; 4) (р = 0,021). Значимые различия в сроках  восстановления опорной способности прооперированной ноги и функции коленного сустава, в частоте применения трамадола в сравниваемых группах отсутствовали. Побочные эффекты и реакции не выявлены.Вывод. Применение фиксированной дозы Неодолпассе в рамках мультимодальной периоперационной аналгезии у пациентов, перенесших  протезирование коленного сустава, способствовало уменьшению выраженности болевого синдрома в послеоперационном периоде

Lorentz Covariant Theory of Light Propagation in Gravitational Fields of Arbitrary-Moving Bodies

The Lorentz covariant theory of propagation of light in the (weak) gravitational fields of N-body systems consisting of arbitrarily moving point-like bodies with constant masses is constructed. The theory is based on the Lienard-Wiechert presentation of the metric tensor. A new approach for integrating the equations of motion of light particles depending on the retarded time argument is applied. In an approximation which is linear with respect to the universal gravitational constant, G, the equations of light propagation are integrated by quadratures and, moreover, an expression for the tangent vector to the perturbed trajectory of light ray is found in terms of instanteneous functions of the retarded time. General expressions for the relativistic time delay, the angle of light deflection, and gravitational red shift are derived. They generalize previously known results for the case of static or uniformly moving bodies. The most important applications of the theory are given. They include a discussion of the velocity dependent terms in the gravitational lens equation, the Shapiro time delay in binary pulsars, and a precise theoretical formulation of the general relativistic algorithm of data processing of radio and optical astrometric measurements in the non-stationary gravitational field of the solar system. Finally, proposals for future theoretical work being important for astrophysical applications are formulated.Comment: 77 pages, 7 figures, list of references is updated, to be published in Phys. Rev. D6

Circumstellar material in the Vega inner system revealed by CHARA/FLUOR

Only a handful of debris disks have been imaged up to now. Due to the need for high dynamic range and high angular resolution, very little is known about the inner planetary region, where small amounts of warm dust are expected to be found. We investigate the close neighbourhood of Vega with the help of infrared stellar interferometry and estimate the integrated K-band flux originating from the central 8 AU of the debris disk. We performed precise visibility measurements at both short (~30 m) and long (~150 m) baselines with the FLUOR beam-combiner installed at the CHARA Array (Mt Wilson, California) in order to separately resolve the emissions from the extended debris disk (short baselines) and from the stellar photosphere (long baselines). After revising Vega's K-band angular diameter (3.202+/-0.005 mas), we show that a significant deficit in squared visibility (1.88+/-0.34%) is detected at short baselines with respect to the best-fit uniform disk stellar model. This deficit can be either attributed to the presence of a low-mass stellar companion around Vega, or as the signature of the thermal and scattered emissions from the debris disk. We show that the presence of a close companion is highly unlikely, as well as other possible perturbations (stellar morphology, calibration), and deduce that we have most probably detected the presence of dust in the close neighbourhood of Vega. The resulting flux ratio between the stellar photosphere and the debris disk amounts to 1.29+/-0.19% within the FLUOR field-of-view (~7.8 AU). Finally, we complement our K-band study with archival photometric and interferometric data in order to evaluate the main physical properties of the inner dust disk. The inferred properties suggest that the Vega system could be currently undergoing major dynamical perturbations.Comment: A&A, accepted -- Press release available at http://www2.cnrs.fr/presse/communique/848.ht