Search results for " Isolation"
showing 10 items of 374 documents
The role of online social comparison as a protective factor for psychological wellbeing: A longitudinal study during the COVID-19 quarantine
2021
During the COVID-19 pandemic crisis, the experience of quarantine has been an undesirable condition for people and it can have a negative impact on mental health and psychological wellbeing. Social isolation has led to an increase in time spent on social network sites, with people interacting more frequently with each other, and comparing online the way in which they are experiencing the same state of home confinement. Our study aimed to investigate the role of online social comparison on individuals' psychological distress and life satisfaction during the COVID-19-related quarantine. Specifically, a cross-lagged panel study at three-waves was conducted in Italy in order to examine the chan…
Sociometric status of young adults: Behavioural correlates, and cognitive-motivational antecedents and consequences
2001
A cross-lagged longitudinal study was carried out to investigate whether social reaction styles and loneliness serve as antecedents and consequences of sociometric status among young adults. Behavioural correlates of sociometric status were also studied. Questionnaires measuring sociometric ratings, social reaction styles, loneliness, and group atmosphere were ”lled in by 154 students one week after starting at a new school, then half a year later, and ”nally, one year later. In Measurement 2, the participants’ social behaviour was rated by their classmates. The results indicated that social reaction styles, feelings of loneliness, and satisfaction with the group atmosphere prospectively p…
Pre- and post-mating reproductive barriers drive divergence of five sympatric species of Naryciinae moths (Lepidoptera: Psychidae)
2014
The biological species concept suggests that species can be separated on the basis of reproductive isolation. However, because natural interbreeding capabilities are often unknown, differences in morphology are generally used to separate species. Alternatively, genetic dissimilarity is used to separate morphologically similar species. Many genetic markers, including the maternally inherited mitochondrial cytochrome oxidase I sequence, cannot show interbreeding and therefore species status of groups may remain unresolved. In species of the genera Dahlica and Siederia (Lepidoptera: Psychidae: Naryciinae) the lack of morphological distinction and unknown interbreeding has led to unclear and un…
Isolated glyoxylic acid-water 1:1 complexes in low temperature argon matrices
2015
Abstract The 1:1 hydrogen bonded complexes between glyoxylic acid (GA) and water are studied in low temperature argon matrices. Four different complex structures were found in deposited matrices. The lowest energy conformer (T1) of GA was found to form complex, where the water molecule was attached to the opposite side of the intramolecular hydrogen bond in the molecule (T1B). Interestingly, this complex was estimated to be +8.0 kJ mol −1 higher in energy than the most stable structure (T1A), where the water is inserted into the internal hydrogen bond, and also found in solid argon but in smaller abundance. For the second-lowest energy conformer of GA (T2), the two lowest-energy complex str…
A TEST FOR REPRODUCTIVE SEPARATION OF ALTERNATE GENERATIONS IN A BIENNIAL SPIDER, ARANEUS DIADEMATUS (ARANEAE, ARANEIDAE)
2002
In Denmark, two seemingly distinct size-classes, 3rd and 4th instar juveniles and repro- ductive adults, of Araneus diadematus are found during every breeding season in autumn, indicating a non-overlapping biennial life-cycle. We tested the hypothesis that alternate generations might experience a degree of reproductive isolation, using the distribution of nuclear (allozyme) and maternal (mtDNA) genetic markers. Individuals of a locality behaved as belonging to a random mating population, irrespective of size. No differences were found between any size-class pairs, within and between 2 yr, or among geographically distant samples. Processes that may lead to this result are discussed: the bien…
Matrix isolation studies on the co-condensation reactions of molecular SiO and GeO: the characterisation of the novel cyclic species SiGeO(2), Si(2)G…
2010
Matrix isolation IR studies, together with DFT calculations, have established that the co-condensation of molecular SiO and GeO in low temperature (12 K) nitrogen matrices leads to the formation of the novel silicon germanium oxide species SiGeO(2), Si(2)GeO(3) and SiGe(2)O(3) analogous to the known dimer and trimer species M(2)O(2) and M(3)O(3) (M = Si, Ge). Controlled diffusion studies in the temperature range 20-34 K result in a significant increase in trimer formation, which implies a very low activation energy for this oligomerisation step. Characteristic IR modes are assigned for all three novel mixed oxide molecules, and the DFT calculations establish that these species have cyclic C…
Rotational Isomerism in Acetic Acid: The First Experimental Observation of the High-Energy Conformer
2003
The high-energy conformer of acetic acid (cis-AA) is produced in an Ar matrix by vibrational excitation of the OH stretching overtone of the ground conformational state (trans-AA). IR-absorption spectroscopy provides a clear identification of the reaction product. cis-AA converts back to trans-AA in a time scale of minutes at 8 K by tunneling. http://dx.doi.org/10.1021/ja038341a
Does the addition of single joint exercises to a resistance training program improve changes in performance and anthropometric measures in untrained …
2018
The present study compared changes in muscle performance and anthropometric measures in young men performing resistance training (RT) programs composed of only multi joint (MJ) exercises, or with the addition of single joint (SJ) exercises (MJ+SJ). Twenty untrained men were randomized to MJ or MJ+SJ groups for 8 weeks. Both groups performed the same MJ exercises. The difference was that the MJ+SJ group added SJ exercises for upper and lower limbs. Participants were tested for 10 repetitions maximum (10RM), flexed arm circumference, and biceps and triceps skinfolds. Both groups significantly increased 10RM load for the bench press (MJ 38.5%, MJ+SJ 40.1%), elbow extension (MJ 28.7%, MJ+SJ 31.…
Diagnosis of inverter-fed induction motors in short time windows using physics-assisted deep learning framework
2019
This article presents a framework for accurate fault diagnostics in inverter-fed induction machinery operating under variable speed and load conditions within very short time windows. Condition indicators based on fault characteristic frequencies observed over the extended Park's vector modulus are fused with deep features extracted using stacked autoencoders to generate a multidimensional feature space for fault classification using support vector machine. The proposed approach is demonstrated in a laboratory setup to detect the most commonly occurring faults, namely, the stator turns fault, broken rotor bars fault and bearing fault with an accuracy > 98% within a short time window of 2–3 …
Hybridization in Calopteryx damselflies: the role of males
2008
Females are often considered responsible for hybridization between two species because usually they are the choosier sex and their cooperation is needed for successful copulation. However, males can also be responsible for hybridization, for example in species in which males are able to force copulation. We studied the pattern of hybridization in two congeneric damselfly species, Calopteryx splendens and Calopteryx virgo, and provide evidence that F1 hybrids between the two damselfly species occur in the wild. According to mitochondrial DNA analysis, hybridization is reciprocal: five of seven hybrids were sired by C. splendens and two by C. virgo males. We conducted an experiment that revea…