2,918 research outputs found
RUNOFF CHARACTERISTICS IN DOBROGEA
This paper aims to highlight the main characteristics of the average liquid flow of the main rivers from Dobrogea: Albeşti, Urlichioi, Biruinţa, Agi Cabul, Slava, Casimcea, Topolog, Taiţa, Cartal, Râmnic. The evidence of these is based on the processing of monthly and yearly discharges taken from the National Institute of Hydrology and Water Management, with periods between 22 and 52 years. The methodology includes statistical analysis, investigations in the area and GIS techniques. The analysis highlights that the mean multiannual discharge ranged between 0.022 m³ s-1 (Urlichioi River) and 0.657 m³ s-1 (Casimcea River). The mean multiannual specific liquid discharge ranged between 0.50 l s-1 km-2 and 8.28 l s-1 km-2, the mean multiannual volume of water ranged between 0.69 million m³ and 20.73 million m³ and the mean multiannual water layer ranged between 15.64 mm and 261.38 mm. The coefficient of interannual variation of the mean discharges ranged between 0.25 and 0.66. Generally, the highest discharges were recorded in June and the lowest in November. So, the richest discharges were recorded in the summer (28.5% – 39.3% of the mean yearly volume of water) and the lowest in the winter and autumn (17% – 25% of the mean yearly volume of water)
Approximations for many-body Green's functions: insights from the fundamental equations
Several widely used methods for the calculation of band structures and photo
emission spectra, such as the GW approximation, rely on Many-Body Perturbation
Theory. They can be obtained by iterating a set of functional differential
equations relating the one-particle Green's function to its functional
derivative with respect to an external perturbing potential. In the present
work we apply a linear response expansion in order to obtain insights in
various approximations for Green's functions calculations. The expansion leads
to an effective screening, while keeping the effects of the interaction to all
orders. In order to study various aspects of the resulting equations we
discretize them, and retain only one point in space, spin, and time for all
variables. Within this one-point model we obtain an explicit solution for the
Green's function, which allows us to explore the structure of the general
family of solutions, and to determine the specific solution that corresponds to
the physical one. Moreover we analyze the performances of established
approaches like over the whole range of interaction strength, and we
explore alternative approximations. Finally we link certain approximations for
the exact solution to the corresponding manipulations for the differential
equation which produce them. This link is crucial in view of a generalization
of our findings to the real (multidimensional functional) case where only the
differential equation is known.Comment: 17 pages, 7 figure
Comparison of Membrane ATPases from Extreme Halophiles Isolated from Ancient Salt Deposits
Halophilic microorganisms were isolated from Triassic and Permian salt deposits. Two were rods and grew as red colonies; another was a coccus and produced pink colonies. The rods lysed in solutions that lacked added sodium chloride. Growth of all isolates was inhibited by aphidicolin and their bulk proteins were acidic as judged from isoelectric focusing. Therefore, these organisms were tentatively identified as extreme halophiles. Whole cell proteins patterns of the isolates following gel electrophoresis were distinct and differed from those of representative type strains of halophilic bacteria. The membrane ATPases from the rods were similar to the enzyme from Halobacterium saccharovorum with respect to sub unit composition. enzymatic properties and immunological cross-reaction, but differed slightly in amino acid composition. If the age of the microbial isolated is similar to that of the salt deposits, they can be considered repositories of molecular information of great evolutionary interest
Special features of the Be2He fragmentation in emulsion at an energy of 1.2~A~GeV
The results of investigations of the relativistic Be nucleus
fragmentation in emulsion which entails the production of two He fragments of
an energy of 1.2~A~GeV are presented. The results of the angular measurements
of the Be2He events are analyzed.
The BeBe+n fragmentation channel involving the Be decay from
the ground (0) and the first excited (2) states to two
particles is observed to be predominant.Comment: 10 pages, 6 figures, conference: Conference on Physics of Fundamental
Interactions, Moscow, Russia, 5-9 Dec 2005 (Author's translation
Some segmental morphological and morphometrical features of the intima and media of the aortic wall in Chinchilla lanigera
Background: The aim of this study is to describe the morphology, morphometry and ultrastructure of segments of the thoracic and abdominal aorta portions in Chinchilla lanigera. Thickness measurements of the tunica intima and media complex of the aorta were taken. Materials and methods: In all observed specimens, the thickness values for the tunica intima and media complex of the cranial thoracic aorta were significantly higher (mean: 702.19 μm) when compared to the values of other analysed aortic segments (means: 354.18 μm; 243.55 μm). Complex statistical methods were used to assess the differences between various aortic segments. Results and Conclusions: The components of the vessel walls show variations in structure and thickness, presumably due to an adaptation to functional demand
Topology of "white" stars in relativistic fragmentation of light nuclei
In the present paper, experimental observations of the multifragmentation
processes of light relativistic nuclei carried out by means of emulsions are
reviewed. Events of the type of "white" stars in which the dissociation of
relativistic nuclei is not accompanied by the production of mesons and the
target-nucleus fragments are considered.
A distinctive feature of the charge topology in the dissociation of the Ne,
Mg, Si, and S nuclei is an almost total suppression of the binary splitting of
nuclei to fragments with charges higher than 2. The growth of the nuclear
fragmentation degree is revealed in an increase in the multiplicity of singly
and doubly charged fragments with decreasing charge of the non-excited part of
the fragmenting nucleus.
The processes of dissociation of stable Li, Be, B, C, N, and O isotopes to
charged fragments were used to study special features of the formation of
systems consisting of the lightest , d, and t nuclei. Clustering in
form of the He nucleus can be detected in "white" stars via the
dissociation of neutron-deficient Be, B, C, and N isotopes.Comment: 20 pages, 3 figures, 9 tables, conference: Conference on Physics of
Fundamental Interactions, Moscow, Russia, 1-5 Mar 2004.(Author's translation
Development and external validation of the Psychosis Metabolic Risk Calculator (PsyMetRiC): a cardiometabolic risk prediction algorithm for young people with psychosis.
BACKGROUND: Young people with psychosis are at high risk of developing cardiometabolic disorders; however, there is no suitable cardiometabolic risk prediction algorithm for this group. We aimed to develop and externally validate a cardiometabolic risk prediction algorithm for young people with psychosis. METHODS: We developed the Psychosis Metabolic Risk Calculator (PsyMetRiC) to predict up to 6-year risk of incident metabolic syndrome in young people (aged 16-35 years) with psychosis from commonly recorded information at baseline. We developed two PsyMetRiC versions using the forced entry method: a full model (including age, sex, ethnicity, body-mass index, smoking status, prescription of a metabolically active antipsychotic medication, HDL concentration, and triglyceride concentration) and a partial model excluding biochemical results. PsyMetRiC was developed using data from two UK psychosis early intervention services (Jan 1, 2013, to Nov 4, 2020) and externally validated in another UK early intervention service (Jan 1, 2012, to June 3, 2020). A sensitivity analysis was done in UK birth cohort participants (aged 18 years) who were at risk of developing psychosis. Algorithm performance was assessed primarily via discrimination (C statistic) and calibration (calibration plots). We did a decision curve analysis and produced an online data-visualisation app. FINDINGS: 651 patients were included in the development samples, 510 in the validation sample, and 505 in the sensitivity analysis sample. PsyMetRiC performed well at internal (full model: C 0·80, 95% CI 0·74-0·86; partial model: 0·79, 0·73-0·84) and external validation (full model: 0·75, 0·69-0·80; and partial model: 0·74, 0·67-0·79). Calibration of the full model was good, but there was evidence of slight miscalibration of the partial model. At a cutoff score of 0·18, in the full model PsyMetRiC improved net benefit by 7·95% (sensitivity 75%, 95% CI 66-82; specificity 74%, 71-78), equivalent to detecting an additional 47% of metabolic syndrome cases. INTERPRETATION: We have developed an age-appropriate algorithm to predict the risk of incident metabolic syndrome, a precursor of cardiometabolic morbidity and mortality, in young people with psychosis. PsyMetRiC has the potential to become a valuable resource for early intervention service clinicians and could enable personalised, informed health-care decisions regarding choice of antipsychotic medication and lifestyle interventions. FUNDING: National Institute for Health Research and Wellcome Trust
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