408 research outputs found
Waves propagation in turbulent superfluid helium in presence of combined rotation and counterflow
A complete study of the propagation of waves (namely longitudinal density and
temperature waves, longitudinal and transversal velocity waves and heat waves)
in turbulent superfluid helium is made in three situations: a rotating frame, a
thermal counterflow, and the simultaneous combination of thermal counterflow
and rotation. Our analysis aims to obtain as much as possible information on
the tangle of quantized vortices from the wave speed and attenuation factor of
these different waves, depending on their relative direction of propagation
with respect to the rotation vector.Comment: 17 pages, 2 figure
Reproductive plasticity of a Procambarus clarkii population living 10\ub0C below its thermal optimum
In this study the annual reproductive biology of a Procambarus clarkii (Girard, 1852) population living in an atypical habitat with cold
spring waters is investigated by monitoring Gonado-Somatic and Hepato-Somatic Indexes (GSI and HSI) and by performing cytology on
ovaries. Despite its known preference for habitats with water temperature from 21 to 30 \ub0C, our results clearly confirm the adaptation of this
population to the atypical thermal habitat, characterised by an annual mean water temperature value of 13.32 \ub10.08 \ub0C. Maximum gonadal
development was reached in August, with maximum GSI median value of 0.64 (instead of reported values even 10 times higher for other
populations), and ovigerous females were found in autumn, with mean realized fecundity of 35 \ub17 compared to 285\u2013995 reported from other
habitats. Histological analysis was consistent with other studies and allowed us to follow ovarian development at cytological level. The
importance of all these results is not to be underestimated: to our knowledge these findings are the first report of the coolest habitat
successfully colonized by this species at the present time and so they have to be taken as a warning about the possible range expansion of P.
clarkii also to northern and colder habitats that have few things in common with the native habitat of the species and, up to now, were
considered \u201csafe\u201d from the invasion of the red swamp crayfish
Stressed caregivers. An observational study in a rehabilitation care home in western Sicily
Introduction: Caregiver is the person who takes care of the patient from the practical point of view, helping him in managing the disease and carrying out daily activities, but also supporting him on an emotional level. Caregiver burnout is a state of physical, emotional, and mental exhaustion that may be accompanied by a change in attitude from positive and caring to negative and unconcerned. The aim of the study was to understand what factors were associated with having panic attacks or crying crises in the caregivers of our study population. Materials and methods: The study design is observational. An anonymous questionnaire was administered to caregivers of the patients of a hospital for the intensive post-acute rehabilitation from April 2016 to December 2018. The statistical significance level chosen for the entire analysis was 0.05. The covariates to be included were selected using a stepwise backward selection process, with a univariate p-value <0.25 as the main criterion. Results are expressed as adjusted Odds Ratio (aOR) with 95% Confidence Intervals (CI). Results: The sample consists of 302 caregivers (60.93% was females and 39.07% was males). The mean age of the sample is 53.42 years old (SD ± 12.19). The multivariable logistic regression model shows that the risk to have panic or crying crisis is significantly associated with the following indipendent variables: female gender (aOR 27.06); living with the patient (aOR 4.38); had claimed that the problems related to the illness of their family member is a source of stress (aOR 23.54), smoking cigarettes (aOR 14.68); had claimed that taking care of their client affected their personal financial statement/career (aOR 5.95), having free time (aOR 7.68). Conclusions: In our study we found a greater probability of having panic attacks or crying crises in female subjects, smokers, who think they have sacrificed their careers to take care of the person they follow from a welfare point of view. Certainly in the light of what has emerged it is necessary to dedicate and pay close attention to the psychological and social aspects of the caregiver
Ventricular arrhythmias in young competitive athletes: Prevalence, determinants, and underlying substrate
Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes.Background--Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes. Method and Results--We studied 288 competitive athletes (age range, 16-35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12-lead 24-hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty-eight athletes (10%) and 13 sedentary individuals (11%) showed > 10 isolated premature ventricular beats (PVBs) or 651 complex VA (P=0.81). Athletes with > 10 isolated PVBs or 651 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with > 10 isolated PVBs or 651 complex VA had a normal echocardiographic examination; 17 of them showing > 500 isolated PVBs, exercise-induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features. Conclusions--The prevalence of > 10 isolated PVBs or 651 complex VA at 24-hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features
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