20 research outputs found
Dependency Structures in Differentially Coded Cardiovascular Time Series
Objectives. This paper analyses temporal dependency in the time series recorded from aging rats, the healthy ones and those with early developed hypertension. The aim is to explore effects of age and hypertension on mutual sample relationship along the time axis. Methods. A copula method is applied to raw and to differentially coded signals. The latter ones were additionally binary encoded for a joint conditional entropy application. The signals were recorded from freely moving male Wistar rats and from spontaneous hypertensive rats, aged 3 months and 12 months. Results. The highest level of comonotonic behavior of pulse interval with respect to systolic blood pressure is observed at time lags τ=0, 3, and 4, while a strong counter-monotonic behavior occurs at time lags τ=1 and 2. Conclusion. Dynamic range of aging rats is considerably reduced in hypertensive groups. Conditional entropy of systolic blood pressure signal, compared to unconditional, shows an increased level of discrepancy, except for a time lag 1, where the equality is preserved in spite of the memory of differential coder. The antiparallel streams play an important role at single beat time lag
On Consistency of Cross-Approximate Entropy in Cardiovascular and Artificial Environments
Cross-approximate entropy (XApEn) quantifies the mutual orderliness of simultaneously recorded time series. Despite being derived from the firmly established solitary entropies, it has never reached their reputation and deployment. The aim of this study is to identify the problems that preclude wider XApEn implementation and to develop a set of solutions. Exact expressions for XApEn and its constitutive parts are derived and compared to values estimated from artificial data. This comparison revealed vast regions within the parameter space that do not guarantee reliable probability estimation, making XApEn estimates inconsistent. A simple correction to one of the XApEn procedural steps is proposed. Three sets of formulae for joint parameter selection are derived. The first one is intended to maximize threshold profile. The remaining ones minimize XApEn instability according to the strong and weak criteria. The derived expressions are verified using cardiovascular signals recorded from rats (long signals) and healthy volunteers (short clinical signals), proposing a change of traditional parameter guidelines
Psychosocial school factors and mental health of first grade secondary school students-Results of the Health Behaviour in School-aged Children Survey in Serbia.
This cross-sectional study aimed to investigate the association between psychosocial school factors and life satisfaction, symptoms of depression and psychosomatic health complaints among first grade secondary school students in Serbia. We analysed data from the 2018 Health Behaviour in School-aged Children (HBSC) study in the Republic of Serbia. Analyzed psychosocial school factors included satisfaction with school, schoolwork pressure, teacher support, classmate support and being bullied at school. Life satisfaction was assessed by the 11-step Cantril's ladder (cutoff >5). Symptoms of depression were measured by the Center for Epidemiologic Studies Depression Scale (CESD-10) and psychosomatic health complaints by using the HBSC symptom checklist. Univariable and multivariable binary logistic regression was used to determine independent predictors of students' life satisfaction, symptoms of depression and psychosomatic health complaints in the school environment, while also considering their socio-demographic characteristics and perceived family and friend support. The study included 1605 students (average age 15.26 ±0.44 years), of whom 50.3% were females. Results from the binary logistic regression analyses showed that life satisfaction was positively related to school satisfaction and classmate support, and negatively to being bullied at school. Symptoms of depression were positively associated with schoolwork pressure and being bullied at school, and negatively with teacher and classmate support. All analyzed factors of the school environment were significantly related to psychosomatic health complaints, whereby schoolwork pressure and being bullied at school were positively associated, while teacher and classmate support and satisfaction with school were negatively associated. Given the established association of psychosocial school factors with mental health, there is a need for targeted measures both at school and community level with the aim of improving social support in the school environment, reducing schoolwork burden and preventing bullying at school, potentially resulting in the overall improvement of mental health of the first grade secondary school students
Interspecific in vitro hybridization in genus Centaurium and identification of hybrids via flow cytometry, RAPD, and secondary metabolite profiles
Most of the species from the genus Centaurium Hill readily hybridize
between themselves in natural habitats. Artificial interspecific hybrid
plants were obtained under in vitro conditions using reciprocal crosses
between 4 species: Centaurium erythraea, C. littorale, C. maritimum, and
C. pulchellum. Among 76 crossing experiments performed, 3 types of
crosses produced seeds and gave 20 interspecific hybrid plants. Nuclear
DNA quantification, fingerprinting of molecular markers, and
determination of variation in main secondary metabolite content were
employed to confirm their hybrid nature. All 3 approaches were capable
of detecting hybrid plants. RAPD molecular markers proved to be the most
reliable, always placing the hybrids between their parents in
dendrograms, while secoiridoid glycoside content also showed
intermediate profiles in the hybrid plants in relation to the parents.
Hence, each of the techniques employed can be recommended for
elucidating the mechanisms of interspecific hybridization in natural
populations of Centaurium species in further studies. This could help to
comprehend their breeding system and recognize interspecific
hybridization as one of the crucial steps in polyploid formation and
speciation in this genus.Ministry of Education, Science, and Technological Development of Serbia
{[}173024
Comet assay and cytogenetic findings in differential diagnosis of fanconi anemia
Fanconi anemia (FA) is a complex genetic disease with a variety of congenital and hematological symptoms, including the predisposition for cancer development. The main hallmark of FA cells, an increased chromosomal fragility, in the presence of the DNA-interstrand cross-linking chemicals, mitomycin C or diepoxybutane (DEB), makes the diagnosis of FA much easier. Cytogenetic method can detect the FA patients with highly elevated chromosomal breakage, but also some of the patients with borderline sensitivity to DEB no matter if they have FA or not. These particular circumstances lead us to introduce comet assay along with cytogenetic analysis, in order to determine DNA lesions and chromosomal fragility in untreated and DEB-treated lymphocytes of full blood from seven patients with clinical features of FA. Highly elevated DEB induced chromosomal sensitivity confirmed the diagnosis in five patients (FA group: 0.48-4.47 breaks/cell vs control group: 0.00-0.08 breaks/cell). Borderline DEB sensitivity (FA* group: 0.15-0.44 breaks/cell) was found in the remaining two patients. Results of the comet assay showed higher baseline and DEB-induced DNA damage values (Olive tail moment and tail intensity) in all five FA and one FA* patient, when compared to the control group. These findings could provide a new model of FA screening test algorithm, including comet assay as additional and very useful accurate tool, beside the DEB test, in differential diagnosis of FA
Psychosocial school and out-of-school environment and mental health of the study respondents.
Psychosocial school and out-of-school environment and mental health of the study respondents.</p
Life satisfaction in relation to psychosocial school and other factors.
Life satisfaction in relation to psychosocial school and other factors.</p
Logistic regression analysis of factors related to life satisfaction among students.
Logistic regression analysis of factors related to life satisfaction among students.</p
Psychosomatic health complaints in relation to psychosocial school and other factors.
Psychosomatic health complaints in relation to psychosocial school and other factors.</p
Psychosocial school and out-of-school factors among students by school type.
Psychosocial school and out-of-school factors among students by school type.</p