3,126 research outputs found
Target motion estimation via a multistatic FSR
The focus of this paper is on the estimation of the kinematic parameters of moving targets
via a MIMO Forward Scatter Radar (FSR) system. A sub-optimum estimation technique is considered
that exploits the information concerning the time instants at which the target crosses the individual
baselines to retrieve the motion parameters. The accuracy of such technique is firstly investigated
from a theoretical point of view and then the effectiveness of the proposed approach is demonstrated
by applying it to live MIMO FSR data. Shown results prove the practical applicability of the proposed
technique
Mitochondrial DNA lineages of Italian Giara and Sarcidano horses
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project (2017)
The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity
The Italian national trends in smoking initiation and cessation according to gender and education
Objectives. This study aims to assess the trend in initiation and
cessation of smoking across successive birth cohorts, according
to gender and education, in order to provide useful suggestion
for tobacco control policy.
Study design. The study is based on data from the ?Health
conditions and resort to sanitary services? survey carried out
in Italy from October 2004 to September 2005 by the National
Institute of Statistics. Through a multisampling procedure
a sample representative of the entire national territory was
selected.
Methods. In order to calculate trends in smoking initiation and
cessation, data were stratified for birth cohorts, gender and edu-
cation level, and analyzed through the life table method.
Results. The cumulative probability of smoking initiation, across
subsequent generations, shows a downward trend followed by
a plateau. This result highlights that there is not a shred of
evidence to support the hypothesis of an anticipation in smok-
ing initiation. The cumulative probability of quitting, across
subsequent generations, follows an upward trend, highlighting
the growing tendency of smokers to become an ?early quitter?,
who give up within 30 years of age.
Conclusion. Results suggest that the Italian antismoking
approach, for the most part targeted at preventing the initiation
of smoking emphasising the negative consequences, has an effect
on the early smoking cessation. Health policies should reinforce
the existing trend of ?early quitting? through specific actions. In
addition our results show that men with low education exhibit
the higher probability of smoking initiation and the lower prob-
ability of early quitting, and therefore should be targeted with
special attention
Robot-aided assessment of wrist proprioception
Introduction: Impaired proprioception severely affects the control of gross and fine motor function. However, clinical assessment of proprioceptive deficits and its impact on motor function has been difficult to elucidate. Recent advances in haptic robotic interfaces designed for sensorimotor rehabilitation enabled the use of such devices for the assessment of proprioceptive function. Purpose: This study evaluated the feasibility of a wrist robot system to determine proprioceptive discrimination thresholds for two different DoFs of the wrist. Specifically, we sought to accomplish three aims: first, to establish data validity; second, to show that the system is sensitive to detect small differences in acuity; third, to establish test–retest reliability over repeated testing. Methodology: Eleven healthy adult subjects experienced two passive wrist movements and had to verbally indicate which movement had the larger amplitude. Based on a subject’s response data, a psychometric function was fitted and the wrist acuity threshold was established at the 75% correct response level. A subset of five subjects repeated the experimentation three times (T1, T2, and T3) to determine the test–retest reliability. Results: Mean threshold for wrist flexion was 2.15° ± 0.43° and 1.52° ± 0.36° for abduction. Encoder resolutions were 0.0075° (flexion–extension) and 0.0032° (abduction–adduction). Motor resolutions were 0.2°(flexion–extension) and 0.3° (abduction–adduction). Reliability coefficients were rT2-T1 = 0.986 and rT3-T2 = 0.971. Conclusion: We currently lack established norm data on the proprioceptive acuity of the wrist to establish direct validity. However, the magnitude of our reported thresholds is physiological, plausible, and well in line with available threshold data obtained at the elbow joint. Moreover, system has high resolution and is sensitive enough to detect small differences in acuity. Finally, the system produces reliable data over repeated testing
The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
Biodiversity continues to decline in the face of increasing anthropogenic pressures
such as habitat destruction, exploitation, pollution and introduction of
alien species. Existing global databases of species’ threat status or population
time series are dominated by charismatic species. The collation of datasets with
broad taxonomic and biogeographic extents, and that support computation of
a range of biodiversity indicators, is necessary to enable better understanding of
historical declines and to project – and avert – future declines. We describe and
assess a new database of more than 1.6 million samples from 78 countries representing
over 28,000 species, collated from existing spatial comparisons of
local-scale biodiversity exposed to different intensities and types of anthropogenic
pressures, from terrestrial sites around the world. The database contains
measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35)
biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains
more than 1% of the total number of all species described, and more than
1% of the described species within many taxonomic groups – including flowering
plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans
and hymenopterans. The dataset, which is still being added to, is
therefore already considerably larger and more representative than those used
by previous quantitative models of biodiversity trends and responses. The database
is being assembled as part of the PREDICTS project (Projecting Responses
of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk).We make site-level summary data available alongside this article. The full database
will be publicly available in 2015
Human cardiomyocyte calcium handling and transverse tubules in mid-stage of post-myocardial-infarction heart failure
Aims:
Cellular processes in the heart rely mainly on studies from experimental animal models or explanted hearts from patients with terminal end-stage heart failure (HF). To address this limitation, we provide data on excitation contraction coupling, cardiomyocyte contraction and relaxation, and Ca2+ handling in post-myocardial-infarction (MI) patients at mid-stage of HF.
Methods and results:
Nine MI patients and eight control patients without MI (non-MI) were included. Biopsies were taken from the left ventricular myocardium and processed for further measurements with epifluorescence and confocal microscopy. Cardiomyocyte function was progressively impaired in MI cardiomyocytes compared with non-MI cardiomyocytes when increasing electrical stimulation towards frequencies that simulate heart rates during physical activity (2 Hz); at 3 Hz, we observed almost total breakdown of function in MI. Concurrently, we observed impaired Ca2+ handling with more spontaneous Ca2+ release events, increased diastolic Ca2+, lower Ca2+ amplitude, and prolonged time to diastolic Ca2+ removal in MI (P < 0.01). Significantly reduced transverse-tubule density (−35%, P < 0.01) and sarcoplasmic reticulum Ca2+ adenosine triphosphatase 2a (SERCA2a) function (−26%, P < 0.01) in MI cardiomyocytes may explain the findings. Reduced protein phosphorylation of phospholamban (PLB) serine-16 and threonine-17 in MI provides further mechanisms to the reduced function.
Conclusions:
Depressed cardiomyocyte contraction and relaxation were associated with impaired intracellular Ca2+ handling due to impaired SERCA2a activity caused by a combination of alteration in the PLB/SERCA2a ratio and chronic dephosphorylation of PLB as well as loss of transverse tubules, which disrupts normal intracellular Ca2+ homeostasis and handling. This is the first study that presents these mechanisms from viable and intact cardiomyocytes isolated from the left ventricle of human hearts at mid-stage of post-MI HF
What do young people know about HIV? Results of a cross sectional study on 18-24-year-old students
Introduction: Increasing people's knowledge of transmission, prevention, early diagnosis, and available treatments is a key step toward HIV control; it means setting the conditions for empowerment and enabling individuals to make aware choices about the prevention strategy best suited to their needs. This study aims to identify unmet needs on HIV knowledge among freshman students. Methods: A cross sectional study was carried out at the University of Cagliari, which is an Italian public state university. Data were collected by means of an anonymous questionnaire; the final sample included 801 students. Results: Results offer a detailed picture of students' knowledge and perceptions of HIV. Several topics deserve to be better understood by students, but the main gaps relate to the pre-exposure prophylaxis and the decreased likelihood of sexually transmitting HIV due to early treatments. Students' vision of the quality of life of people living with HIV was negatively affected by perceiving as relevant the effects of HIV on physical health or on sexual/affective domains, while conversely, it seemed positively affected by knowing that current treatments are useful for counteracting physical symptoms and decreasing the possibility of transmitting HIV. Conclusion: Being aware of the potential benefits of current therapies could favour a less negative view, in line with the current state of the beneficial effects of HIV treatment. Universities are a valuable setting to bridge the HIV knowledge gap and thus also contribute to tackling stigma and actively promoting HIV testing
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