Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
160 result(s) for "Ristic, B."
Sort by:
Correlation between social functioning and quality of life in patients diagnosed with schizophrenia
IntroductionSocial dysfunction is a significant feature of schizophrenia leading to deminution of quality of life (QoL).ObjectivesTo explore the correlation between social functioning and quality of life in patients diagnosed with schizophrenia.MethodsThe study sample comprised 32 patients diagnosed with schizophrenia (24 males and 8 females) recruited from the Clinic for mental disorders “Dr Laza Lazarevic” in Belgrade, with a mean age of 41.28 years (min 24, max 62), assessed by the Social Functioning Scale (SFS) and the World Health Organization Quality of Life questionnaire (WHOQOL-BREF).ResultsThere were two significant quasi-canonical positive correlations between social functioning and QoL (1: f-test=16.4, p=.001; 2: f-test=23, p=0.0001.) The first structure is formed through the set of SFS subscales- Recreation, Independence-performance and Independence-competence and set of QoL subscales- Mental health, Physical health, Environment and General assessment of QoL. The second structure is formed through the set of SFS subscales- Interpersonal functioning and Social engagement/withdrawal and the set of QoL subscales- General assessment of QoL and Environment. Furthermore, the first canonical component indicates a greater overlap of the opposition set by social functioning (23%) which leads to the assumption that the direction of influence goes from social functioning to QoL. Due to the equality of redundancy in the second canonical component, the direction of influence can only be inferred on the basis of the first canonical component.ConclusionsSocial functioning and quality of life are related in patients diagnosed with schizophrenia, and this relationship is based on specific subfactors within those areas.DisclosureNo significant relationships.
Martian water loss to space enhanced by regional dust storms
Mars has lost most of its initial water to space as atomic hydrogen and oxygen. Spacecraft measurements have determined that present-day hydrogen escape undergoes large variations with season that are inconsistent with long-standing explanations. The cause is incompletely understood, with likely contributions from seasonal changes in atmospheric circulation, dust activity and solar extreme ultraviolet input. Although some modelling and indirect observational evidence suggest that dust activity can explain the seasonal trend, no previous study has been able to unambiguously distinguish seasonal from dust-driven forcing. Here we present synoptic measurements of dust, temperature, ice, water and hydrogen on Mars during a regional dust event, demonstrating that individual dust events can boost planetary H loss by a factor of five to ten. This regional storm occurred in the declining phase of the known seasonal trend, establishing that dust forcing can override this trend to drive enhanced escape. Because similar regional storms occur in most Mars years, these storms may be responsible for a large fraction of Martian water loss and represent an important driver of Mars atmospheric evolution. Multi-spacecraft observations of temperature, dust and water ice opacities, water vapour abundances, and thermospheric hydrogen in the atmosphere of Mars during a local dust storm show that even such regional events, much more frequent than global dust storms, can boost global atmospheric escape by a factor of five to ten.
Strong Localized Pumping of Water Vapor to High Altitudes on Mars During the Perihelion Season
Here we present water vapor vertical profiles observed with the ExoMars Trace Gas Orbiter/Nadir and Occultation for MArs Discovery instrument during the perihelion and Southern summer solstice season (LS = 240°–300°) in three consecutive Martian Years 34, 35, and 36. We show the detailed latitudinal distribution of H2O at tangent altitudes from 10 to 120 km, revealing a vertical plume at 60°S–50°S injecting H2O upward, reaching abundance of about 50 ppmv at 100 km. We have observed this event repeatedly in the three Martian years analyzed, appearing at LS = 260°–280° and showing inter‐annual variations in the magnitude and timing due to long term effects of the Martian Year 34 Global Dust Storm. We provide a rough estimate of projected hydrogen escape of 3.2 × 109 cm−2 s−1 associated to these plumes, adding further evidence of the key role played by the perihelion season in the long term evolution of the planet's climate. Plain Language Summary Studying the vertical distribution of the Martian atmosphere is crucial to understand what happened to the water presumably present in larger abundance on ancient Mars. We have analyzed the vertical profiles of three Martian Years during the Southern summer, revealing a strong vertical transport of water vapor to the upper atmosphere. This seasonal phenomenon seems to be repeated annually, although with variations in the location and time of the year. Our estimation of the associated upward hydrogen flux represents an important loss which could have contributed to the escape of water to space for at least the period in which Mars had its present orbital inclination. Key Points Latitudinal distributions of water vapor up to 120 km are analyzed in detail using Nadir and Occultation for MArs Discovery (NOMAD) observations with an improved retrieval scheme Water vapor injection during the perihelion localized around 50°–60°S in three consecutive Martian years Martian year 34 Global Dust Storm may have affected the driving mechanisms of the plume, delaying its appearance and reducing its magnitude
Gender differences in clinical features and quality of life of patients with axial spondyloarthritis and psoriatic arthritis
Objective. The aim of the current study was to compare the clinical and treatment characteristics and dimensions of health-related quality of life between female and male patients with axial spondyloarthritis (SpA) and psoriatic arthritis (PsA). Methods. The present study is cross-sectional and comprises 119 patients with axial SpA and 198 patients with PsA. Clinical data were collected by standardized and self-reported instruments. Disease activity was evaluated by the Ankylosing Spondylitis Disease Activity Score with C-reactive protein and the Disease Activity in PSoriatic Arthritis (for SpA and PsA, respectively). Health-related quality of life was assessed with the Medical Outcomes Study 36-item Short Form Survey. Patients were stratified by gender, and the socio-demographic, clinical, and quality-of-life data were compared. Results. Women with axial SpA and PsA had significantly lower education (p<0.001, p=0.004, respectively) and higher disease activity (p<0.001, p=0.003, respectively). Female patients with axial SpA were more frequently under second-line therapy (p=0.026) and glucocorticoid treatment (p=0.005), while women with PsA had more radiographic progression (p=0.006). Female patients with axial SpA and PsA had worse scores in the dimensions of quality of life regarding physical role, bodily pain, vitality, and mental health. Women with axial SpA had lower scores in general health, while women with PsA had lower scores in physical and social functioning. Conclusions. Women with axial SpA and PsA had worse scores than men in most clinical and treatment characteristics and health-related quality of life dimensions.
Speed Controlled Belt Conveyors: Drives and Mechanical Considerations
The paper presents variable speed belt conveyor system where the reference speed is changed in order to achieve improved energy efficiency of operation. The recorded measurements show that belt tension varies within the same limits as under constant speed operation. These results introduce a new insight of the present state of the art in variable speed belt conveyor drives. The system is realized with remote control from the control center on an open pit mine. The structure of the multi-motor drive system of a single conveyor, as well as of the network-based control system distributed among belt conveyor stations and the control center are shown. Speed control of a belt conveyor system is organized to provide better utilization of the available material cross section on the belt and reduced electrical energy consumption of the drive. The experimental results obtained on the system prove that, under existing constraints, the applied algorithm has not introduced additional stress to the belt or mechanical assemblies during acceleration and deceleration processes, while providing higher energy efficiency of operation.
Evidence for transient morning water frost deposits on the Tharsis volcanoes of Mars
The present-day water cycle on Mars has implications for habitability and future human exploration. Water ice clouds and water vapour have been detected above the Tharsis volcanic province, suggesting the active exchange of water between regolith and atmosphere. Here we report observational evidence for extensive transient morning frost deposits on the calderas of the Tharsis volcanoes (Olympus, Arsia and Ascraeus Montes, and Ceraunius Tholus) using high-resolution colour images from the Colour and Stereo Surface Imaging System on board the European Space Agency’s Trace Gas Orbiter. The transient bluish deposits appear on the caldera floor and rim in the morning during the colder Martian seasons but are not present by afternoon. The presence of water frost is supported by spectral observations, as well as independent imagery from the European Space Agency’s Mars Express orbiter. Climate model simulations further suggest that early-morning surface temperatures at the high altitudes of the volcano calderas are sufficiently low to support the daily condensation of water—but not CO 2 —frost. Given the unlikely seasonal nature of volcanic outgassing, we suggest the observed frost is atmospheric in origin, implying the role of microclimate in local frost formation and a contribution to the broader Mars water cycle. High-resolution spacecraft imagery has revealed transient deposits that appear in the early mornings of cold seasons at the high altitudes of the Tharsis volcanoes on Mars, consistent with water frost of atmospheric origin.
Detection of green line emission in the dayside atmosphere of Mars from NOMAD-TGO observations
The oxygen emission at 557.7 nm is a ubiquitous component of the spectrum of the terrestrial polar aurora and the reason for its usual green colour 1 . It is also observed as a thin layer of glow surrounding the Earth near 90 km altitude in the dayside atmosphere 2 , 3 but it has so far eluded detection in other planets. Here we report dayglow observations of the green line outside the Earth. They have been performed with the Nadir and Occultation for Mars Discovery ultraviolet and visible spectrometer instrument on board the European Space Agency’s ExoMars Trace Gas Orbiter. Using a special observation mode, scans of the dayside limb provide the altitude distribution of the intensity of the 557.7 nm line and its variability. Two intensity peaks are observed near 80 and 120 km altitude, corresponding to photodissociation of CO 2 by solar Lyman α and extreme ultraviolet radiation, respectively. A weaker emission, originating from the same upper level of the oxygen atom, is observed in the near ultraviolet at 297.2 nm. These simultaneous measurements of both oxygen lines make it possible to directly derive a ratio of 16.5 between the visible and ultraviolet emissions, and thereby clarify a controversy between discordant ab initio calculations and atmospheric measurements that has persisted despite multiple efforts. This ratio is considered a standard for measurements connecting the ultraviolet and visible spectral regions. This result has consequences for the study of auroral and airglow processes and for spectral calibration. The oxygen emission at 557.7 nm, responsible for the green colour of auroras on Earth, is present in two layers at 80 and 120 km altitude on the dayside atmosphere of Mars. Simultaneous observations of the oxygen both in this visible line and in the ultraviolet could also constrain the elusive visible/ultraviolet intensity ratio of the auroral emission to a value of 16.5.
Martian Ozone Observed by TGO/NOMAD‐UVIS Solar Occultation: An Inter‐Comparison of Three Retrieval Methods
The NOMAD‐UVIS instrument on board the ExoMars Trace Gas Orbiter has been investigating the Martian atmosphere with the occultation technique since April 2018. Here, we analyze almost two Mars Years of ozone vertical distributions acquired at the day‐night terminator. The ozone retrievals proved more difficult than expected due to spurious detections of ozone caused by instrumental effects, high dust content, and very low values of ozone. This led us to compare the results from three different retrieval approaches: (a) an onion peeling method, (b) a full occultation Optimal Estimation Method, and (c) a direct onion peeling method. The three methods produce consistently similar results, especially where ozone densities are higher. The main challenge was to find reliable criteria to exclude spurious detections of O3, and we finally adopted two criteria for filtering: (a) a detection limit, and (b) the Δχ2 criterion. Both criteria exclude spurious O3 values especially near the perihelion (180° < Ls < 340°), where up to 98% of ozone detections are filtered out, in agreement with general circulation models, that expect very low values of ozone in this season. Our agrees well with published analysis of the NOMAD‐UVIS data set, as we confirm the main features observed previously, that is, the high‐altitude ozone peak around 40 km at high latitudes. The filtering approaches are in good agreement with those implemented for the SPICAM/MEx observations and underline the need to evaluate carefully the quality of ozone retrievals in occultations. Key Points We compare three different retrieval codes and different criteria to filter spurious detection of ozone on Mars The filtering criteria demonstrate the ozone detection in perihelion season is mostly spurious in both years The three retrieval methods produce consistent results with a maximum percentage difference of ∼30% for large ozone densities below 50 km
Observation of the Mars O2 visible nightglow by the NOMAD spectrometer onboard the Trace Gas Orbiter
On Mars, atomic oxygen controls the carbon dioxide radiative cooling of the upper atmosphere and the presence of an ozone layer near the poles. To remotely probe meridional transport of O atoms from the summer to the winter hemisphere and the descending flow in the winter polar regions, the O 2 Herzberg II atmospheric emission could be used as a proxy. This emission is quite weak on Earth’s nightside, but it is prominent in the Venus night airglow, and it has not previously been observed on Mars. Here we report the limb detection of the O 2 Herzberg II visible bands in the Mars nightglow with the NOMAD ultraviolet–visible spectrometer onboard the European Space Agency’s Trace Gas Orbiter. The emission layer reaches up to hundreds of kilorayleighs in the limb viewing geometry. It is mainly located between 40 km and 60 km at high latitudes during the winter season, consistent with three-body recombination of oxygen atoms. This O 2 nightglow should be observable from a Martian orbiter as well as from the Martian surface with the naked eye under clear sky conditions. These observations pave the way to future global observations of the Martian atmospheric circulation with simpler lower-cost instrumentation. ESA’s Trace Gas Orbiter reveals that the winter night sky on Mars emits visible light between 50 km and 70 km altitude in the polar regions. This nightglow should be observable with simple space camera systems and the naked eyes of future Mars astronauts.
Bearings-Only Tracking of Manoeuvring Targets Using Particle Filters
We investigate the problem of bearings-only tracking of manoeuvring targets using particle filters (PFs). Three different (PFs) are proposed for this problem which is formulated as a multiple model tracking problem in a jump Markov system (JMS) framework. The proposed filters are (i) multiple model PF (MMPF), (ii) auxiliary MMPF (AUX-MMPF), and (iii) jump Markov system PF (JMS-PF). The performance of these filters is compared with that of standard interacting multiple model (IMM)-based trackers such as IMM-EKF and IMM-UKF for three separate cases: (i) single-sensor case, (ii) multisensor case, and (iii) tracking with hard constraints. A conservative CRLB applicable for this problem is also derived and compared with the RMS error performance of the filters. The results confirm the superiority of the PFs for this difficult nonlinear tracking problem.