929 research outputs found

    Evolution of drop size distribution in natural rain

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    Both numerical modeling and laboratory experiments document the possibility of a raindrop size distribution (DSD) to evolve to an equilibrium stage (EDSD), where all the principal processes occur at steady rates. The aim of this work is to observe the temporal behavior of the DSD and to directly investigate the conditions favorable to the onset of the EDSD in natural rain. We exploited a large disdrometer dataset collected in the framework of the Ground Validation activities related to the NASA Global Precipitation Measurement mission. More than 200,000 one-minute data of two-dimensional video disdrometer (2DVD) are collected over USA to represent a wide range of precipitation types. The original data are averaged over 2 min and an automatic algorithm is used on a selected subset to identify samples with EDSD. Results show that the EDSD occurs mainly in convective events and lasts for very short time intervals (2 to 4 min). It is more frequent for rain rate between 20 and 40 mm h−1 and it mostly occurs during sharp increase of precipitation rates

    Proizvodnja i sastav mleka autohtone rase ovaca u Makedoniji

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    Several production traits have been examined in 180 Ovchepolian sheep during a four-year production period (2010-2013). The sheep ranged in age from the first to the 7th lactation and 4319 individual lactation controls were realized in total. Besides the basic statistics, all data were analysed using a multi-factorial fixed model. The influence of certain factors was studied using the F-test and the analyses were made using the SPSS set of programs. Most of the factors (year, lactation, lambing month and number of milk recording) had a highly significant influence (P (lt) 0.001) on daily milk production (milk from the morning, evening and the total amount of milk, % of milk fat and kg fat) in this breed of sheep. The month of milk recording also had a significant influence (P (lt) 0.05) on all traits. Only fertility had no impact on the variations in the tested parameters, aside from the total daily milk, on which a highly significant influence was manifested (P (lt) 0.01). The average milk lactation among the tested sheep population during all four years was, on average, 58 ± 0.247 l, while the production of milked milk for the same period was 37 ± 0.217 l. The length of the lactation period in these sheep for the four years studied averaged 182 ± 0.31 days. The maximal daily milk yield in this sheep population was measured in 2011 (0.302 ± 0.26 l). Regarding their age, the highest daily milk yield was determined in sheep in the third lactation (0.365 ± 0.26), while those in the 7th lactation had the lowest (0.255 ± 0.27).Ispitivano je nekoliko proizvodnih svojstava (laktacijska proizvodnja mleka, proizvodnja mleka u dojnom periodu, proizvodnja mleka u muznom periodu, dužina dojnog perioda, dužina laktacije, proizvodnja mleka u toku jutarnje muže, proizvodnja mleka u toku večernje muže i dnevna proizvodnja mleka) kod ukupno 180 ovcepoljskih ovaca, u toku četiri proizvodne godine (2010-2013). Uzrast ovaca bio je od prve do sedme laktacije, i kod njih je bilo realizovano ukupno 4319 individualnih laktacijskih kontrola. Osim bazične statistike, svi podaci su analizirani pomoću višefaktorijalnog fiksnog modela. Uticaj posebnih faktora ispitivan je pomoću F-testa, dok su analize urađene pomoću programskog paketa SPSS. Veći broj faktora (godina, laktacija, mesec jagnjenja i broj kontrole mleka), imali su visoko značajni uticaj (P (lt) 0,001), na dnevnu proizvodnju mleka (jutarnje, večernje i ukupno mleko, % mlečne masti i kg mlečne masti), kod ove rase ovaca. Mesec kontrole mleka u odnosu na sva svojstva imao je visoko značajni uticaj (P (lt) 0,001), osim na % mlečne masti (P>0,05). Jedino plodnost nije imala nikakav uticaj na varijacije ispitivanih parametara, osim na ukupnu dnevnu produkciju mleka, na koju je manifestovala visoko značajni uticaj (P (lt) 0,001). Prosečna laktacijska mlečnost kod ispitivane populacije ovaca, sa sve četiri godine u proseku je bila 58 ± 0,247 l, dok je proizvodnja muznog mleka u istom periodu bila 37 ± 0,217 l. Dužina laktacijskog perioda u toku četiri ispitivane godine u proseku je bila 182 ± 0,31 dana. Maksimalna dnevna mlečnost kod ove rase ovaca, izmerena je u toku 2011. godine (0,302 ± 0,26 l). U odnosu na starost, najveća dnevna mlečnost je utvrđena kod ovaca u trećoj laktaciji (0,365 ± 0,26), a najniža u sedmoj laktaciji (0,255 ± 0,27)

    Pulmonary transit time as a marker of diastolic dysfunction in Takotsubo syndrome

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    AIM: To evaluate the pulmonary transit time (PTT) and its derived parameters using cardiac magnetic resonance imaging (CMRI) as markers of diastolic dysfunction in Takotsubo syndrome (TS) and its relationship with transthoracic echocardiography and CMRI parameters. MATERIALS AND METHODS: Twenty-two patients with TS, who exhibited diastolic dysfunction as assessed by transthoracic echocardiography, were enrolled retrospectively and the PTT, pulmonary transit time index (PTTI), and pulmonary blood volume index (PBVI) were evaluated using first-pass CMRI. PTT was calculated as the number of cardiac cycles required for a bolus of contrast agent to move from the right ventricle (RV) to the left ventricle (LV), whereas PTTI represents the PTT interval corrected for the heart rate. Finally, PBVI was calculated as the product of PTTI, and RV stroke volume indexed for body surface area. Normal references of PTT, PTTI, and PBVI were evaluated in a cohort of 20 age- and sex-matched healthy controls. RESULTS: Compared with healthy subjects, TS patients showed significantly higher PTT, PTTI, and PBVI (p=0.0001, p=0.0001, and p=0.002, respectively). Using multivariable logistic regression, PBVI provided the best differentiation between TS and controls (AUC 0.84). PBVI was significantly associated with the index of diastolic dysfunction and left atrial strain parameters. In addition, PBVI demonstrated a significant correlation with global T2 mapping (r=0,520, p=0,019). CONCLUSION: PTT and the derived parameters, as assessed using first-pass CMRI, are potential tools for assessing LV diastolic dysfunction in patients with TS

    Reproductive patterns in deep versus shallow populations of the precious Mediterranean gorgonian Corallium rubrum ( Linnaeus, 1758) ( Sardinia, Central-Western Mediterranean)

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    This study quanti es the main reproductive features of the long-lived red coral Corallium rubrum, an octocoral endemic to the Mediterranean Sea and neighbouring Atlantic areas and one of the most valuable of all marine species, at different depths (38-40 m versus 96-115 m) in the north-western Sardinian waters (Central-Western Mediterranean Sea). Different population structures were observed with shallow colonies smaller (in basal diameter and height) than deeper ones. Both populations were all gonochoric at polyp and colony level and fertile. The sex-ratio was balanced in the deep red corals while in the shallow ones it was signi cantly biased towards female. Deep and shallow colonies were found to have a synchronous female sexual products development in the two depth ranges investigated. C. rubrum produced large female sexual products in both depth intervals in relationship with its reproductive mode, con rming a long oogenic development. In contrast to reproductive timing, the volume occupied by female sexual products per polyp was different between the populations, being higher in the deep than in the shallow populations. C. rubrum exhibited a reproductive strategy characterized by a relative low number of female sexual products per polyp revealing signi cant differences among the two depth ranges analyzed with a lower mean value of sexual products in the shallow colonies (mean fecundity per polyp: 1.14) than in the deeper ones (mean fecundity per polyp: 2.09). These results indicate differences in reproductive parameters such as sexual products distribution and reproductive output (fecundity) which were observed between shallow and deep populations of C. rubrum, in particular within deep dwelling populations

    Uticaj faktora na proizvodna svojstva kod meleza Awassi ovce i ovčepoljske pramenke u Makedoniji

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    The purpose of the survey was to determine a bond between certain factors that affect most of the production traits in crossbreeds between Awassi and Ovchepolian indigenous sheep in Macedonia. We implemented 1145 individual lactation controls in two years of production (2012 and 2013). The impact of individual factors is studied using F-test and the analyses are made using SPSS set of programs. Many factors (lactation, lambing month and number of milk controls) had highly significant impact (P (lt) 0.001) on daily milk production (morning, evening and total milk, fat percentage and fat kg) in this breed of sheep. Only fertility had no impact on any of the examined factors, with the exception of total daily milk, on which manifested with highly significant impact (P (lt) 0.01). The average milk yield in examined crossbred sheep was 109 ± 0.479 l in two years of production, while the production of milked milk was 72 ± 0.421 l for the same period of time. The length of lactation period in these sheep was average 203 ± 0.61 days, for two analysed years. In relation to the age, in second lactation sheep was determined somewhat higher daily milk yield (0.478 ±0.01 l.), compared to sheep in first lactation (0.475 ± 0.01 l.). This is quite logical, keeping in mind the lactation curve in sheep, especially those of dairy breeds to which Awassi breed belongs.Cilj ovih istraživanja, bio je da se utvrdi veza između nekih faktora koji imaju uticaj na proizvodna svojstva kod meleza između rase Awassi i autohtone ovčepoljske ovce u Makedoniji. Uključili smo ukupno 1145 individualnih laktacijskih kontrola, u toku dve proizvodne godine (2012 i 2013). Uticaj posebnih faktora ispitivan je pomoću F-testa, dok su analize dobijenih podatka urađene pomoću programskog paketa SPSS. Veći broj faktora (laktacija, mesec jagnjenja i broj kontrole mlečnosti) imali su visoko značajan uticaj (P (lt) 0.001) na dnevnu proizvodnju mleka (jutarnje, večernje i ukupno mleko, % mlečne masti i kg mlečne masti). Jedino plodnost nije imala nikakav uticaj na ispitivane faktore, osim na ukupnu dnevnu produkciju mleka, gde je manifestovan visoko značajan uticaj (P (lt) 0.01). Prosečna laktacijska mlečnost kod ispitivanih meleza, bila je 109 ±0.479 l za dve proizvodne godine, dok je proizvodnja muznog mleka u istom periodu bila 72 ± 0,421 l. Dužina laktacijskog perioda u toku dve ispitivane godine u proseku je bila 203 ± 0,61 dana. U odnosu na uzrast, kod meleza u drugoj laktaciji je utvrđena nešto veća dnevna mlečnost (0.478 ±0.01 l.) u poređenju sa melezima u prvoj laktaciji (0.475 ± 0.01 l.). Ovo je sasvim logično imajući u vidu laktacijske krive kod ovce, posebno kod mlečne rase, gde pripada i Awassi rasa

    Reproductive aspects of the velvet belly lantern shark Etmopterus spinax (Condrichthyes: Etmopteridae), from the central western Mediterranean sea. Notes on gametogenesis and oviducal gland microstructure.

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    In this paper, the reproductive biology of the velvet belly lanternshark Etmopterus spinax was analyzed in Sardinian waters (central western Mediterranean). This species was sexually dimorphic with females growing to a larger size than males. Marked sexual dimorphism in size was also observed along the vertical gradient. Histological analysis of gonads was very useful in assigning macroscopical maturity stages. The investigation on the microstructure of oviducal gland (OG) highlighted four morphofunctional zones with mucous and/or proteic secretions according to the zone and to their specific functions and development. Sperm in the OG was found for the first time in E. spinax. The localization of sperm storage tubules deeper in OG suggested long-term sperm storage, which is in agreement with the long reproductive cycle described. This species matured late, specifically at 80.7% and 79% at the maximum observed size for females and males respectively. Mature specimens were found throughout the year with pregnant females observed in winter and autumn. A low fecundity was observed with a mean ovarian fecundity of 16.5 mature follicles

    Crucial role of α4 and α6 nicotinic acetylcholine receptor subunits from ventral tegmental area in systemic nicotine self-administration

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    The identification of the molecular mechanisms involved in nicotine addiction and its cognitive consequences is a worldwide priority for public health. Novel in vivo paradigms were developed to match this aim. Although the beta2 subunit of the neuronal nicotinic acetylcholine receptor (nAChR) has been shown to play a crucial role in mediating the reinforcement properties of nicotine, little is known about the contribution of the different alpha subunit partners of beta2 (i.e., alpha4 and alpha6), the homo-pentameric alpha7, and the brain areas other than the ventral tegmental area (VTA) involved in nicotine reinforcement. In this study, nicotine (8.7-52.6 microg free base/kg/inf) self-administration was investigated with drug-naive mice deleted (KO) for the beta2, alpha4, alpha6 and alpha7 subunit genes, their wild-type (WT) controls, and KO mice in which the corresponding nAChR subunit was selectively re-expressed using a lentiviral vector (VEC mice). We show that WT mice, beta2-VEC mice with the beta2 subunit re-expressed exclusively in the VTA, alpha4-VEC mice with selective alpha4 re-expression in the VTA, alpha6-VEC mice with selective alpha6 re-expression in the VTA, and alpha7-KO mice promptly self-administer nicotine intravenously, whereas beta2-KO, beta2-VEC in the substantia nigra, alpha4-KO and alpha6-KO mice do not respond to nicotine. We thus define the necessary and sufficient role of alpha4beta2- and alpha6beta2-subunit containing nicotinic receptors (alpha4beta2*- and alpha6beta2*-nAChRs), but not alpha7*-nAChRs, present in cell bodies of the VTA, and their axons, for systemic nicotine reinforcement in drug-naive mic

    Relationship between white matter hyperintensities volume and the circle of Willis configurations in patients with carotid artery pathology

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    Purpose We aimed to assess if there is a difference of distribution and volume of white matter hyperintensities (WMH) in the brain according to the Circle of Willis (CoW) configuration in patients with carotid artery pathology. Material and methods One-hundred consecutive patients (79 males, 21 females; mean age 70 years; age range 46–84 years) that underwent brain MRI before carotid endarterectomy (CEA) were included. FLAIR-WMH lesion volume was performed using a semi-automated segmentation technique and the status of the circle of Willis was assessed by two neuroradiologists in consensus. Results We found a prevalence of 55% of variants in the CoW configuration; 22 cases had one variants (40%); 25 cases had two variants (45.45%) and 8 cases showed 3 variants (14.55%). The configuration that was associated with the biggest WMH volume and number of lesions was the A1 + PcoA + PcoA. The PcoA variants were the most prevalent and there was no statistically significant difference in number of lesions and WMH for each vascular territory assessed and the same results were found for AcoA and A1 variants. Conclusion Results of our study suggest that the more common CoW variants are not associated with the presence of an increased WMH or number of lesions whereas uncommon configurations, in particular when 2 or more segment are missing increase the WMH volume and number of lesions. The WHM volume of the MCA territory seems to be more affected by the CoW configuration
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