899 research outputs found
New to Westphalia: a local naturalization of the Blue Star Creeper (Pratia pedunculata [R. BR.] BENTH.) in Bochum (Ruhr area, Germany)
Der Blaue Bubikopf (Pratia pedunculata, Lobeliaceae), eine Zierpflanze aus Australien, hat sich in zwei Zierrasen in Bochum-Querenburg eingebĂŒrgert, wie dies vom echten Bubikopf (Soleirolia soleirolii) im Stadtgebiet schon lĂ€nger bekannt ist. Ăber die FundumstĂ€nde und die Geschichte der EinbĂŒrgerung der fĂŒr Westfalen neuen Art wird berichtet.The Blue Star Creeper (Pratia pedunculata, Lobeliaceae) an Australian native plant that is used ornamentally in Central Europe has been found naturalized in two lawns in Bochum-Querenburg (Ruhr Area, Germany). The species is considered new to the flora of Westphalia
Patterns of genetic structure among Hawaiian corals of the genus Pocillopora yield clusters of individuals that are compatible with morphology.
International audienceSix variable sequence markers are developed and analyzed to find out species boundaries in Hawaiian corals of the genus Pocillopora: the putative mitochondrial control region; a recently discovered, hypervariable mitochondrial open reading frame; the internal transcribed spacer 2 (ITS2), located in the nuclear ribosomal DNA; three nuclear introns of calmodulin, elongation factor-1alpha and the ATP synthase beta subunit. Using the first two markers, we identify five distinct mitochondrial lineages and these lineages are compatible with morphology. The situation is more complex with nuclear markers since more than two haplotypes are observed in some individuals. To detect clusters of individuals, haplotype networks are constructed with additional connections drawn between co-occurring haplotypes to delineate potential fields for recombination: few clusters of nuclear haplotypes are found to correspond to clusters of individuals, but those that are detected (mostly in the ITS2 dataset) are also compatible with morphology
Deux approches contrastées our développer les compétences transversales dans les grands groupes universitaires
peer reviewe
Adolescents' longitudinal trajectories of mental health and loneliness: the impact of COVID-19 school closures
INTRODUCTION: Longitudinal research examining the impact of coronavirus disease 2019 (COVIDâ19) school closures on the mental health of adolescents is scarce. Prolonged periods of physical and social isolation because of such restrictions may have impacted heavily on adolescentsâ mental health and loneliness. METHODS: The current study addresses a major gap by examining the impact of school closures on the mental health and loneliness of 785, 10â to 17âyearâold Western Australian adolescents (mean ageâ=â14.1, SDâ=â1.31), who were surveyed across four time points: twice before COVIDâ19, once as schools closed, and once post reopening of schools. Preâ and postâCOVIDâ19 changes in mental health and loneliness were compared using linear mixed models. Random intercept crossâlagged panel models (RIâCLPMs) assessed temporal associations between loneliness, depression symptoms, and positive mental wellbeing. RESULTS: Compared with preâCOVIDâ19 symptom levels, there were significant increases in depression symptoms, internalizing and externalizing symptoms, and a significant decrease in positive mental wellbeing at different points over time. Symptom change over time differed according to gender and preâCOVIDâ19 symptom severity. Significant increases in positive attitudes towards being alone and feelings of isolation occurred at different points over time. Gender differences were evident. RIâCLPMs highlighted the predictive significance of friendship quality and having a negative attitude towards being alone over time in relation to depression symptoms. A positive or negative attitude towards being alone was predictive of positive mental wellbeing over time. CONCLUSION: Findings provide evidence that COVIDâ19ârelated school closures adversely affected adolescents' mental health and feelings of loneliness
Longitudinal trajectories of mental health and loneliness for Australian adolescents with-or-without neurodevelopmental disorders: the impact of COVID-19 school lockdowns
BACKGROUND: The impact of COVIDâ19 (SARSâCoVâ2) pandemic school lockdowns on the mental health problems and feelings of loneliness of adolescents with neurodevelopmental disorders (NDDs) is hypothesized to be greater than that of their nonâNDD peers. This two and a half year longitudinal study compared changes in the mental health and loneliness of Western Australian adolescents preâCOVIDâ19 (November 2018 and April 2019), immediately prior to COVIDâ19 school lockdowns (March 2020), and post schools reopening (July/August 2020). METHODS: An ageâandâgender matched sample of 476 adolescents withâorâwithout NDDs completed online assessments for mental health and loneliness. RESULTS: Adolescents with NDDs reported elevated levels of adverse mental health across all four waves of data collection. These young people experienced little change in mental health problems and feelings of loneliness over time, and any increase during school lockdowns returned to, or fell below preâCOVIDâ19 levels once schools reopened. In comparison, adolescents without NDDs experienced significant increases from a low baseline in depression symptoms, externalizing symptoms, feelings of isolation, and having a positive attitude to being alone, and evidenced a significant decline in positive mental wellbeing. Quality of friendships were unaffected by COVIDâ19 school lockdowns for all adolescents regardless of NDD status. Of the adolescents with NDDs, those with AttentionâDeficit/Hyperactivity Disorder reported a significant increase in positive mental wellbeing following school lockdowns. CONCLUSIONS: Adolescents with NDDs emerged relatively unscathed from COVIDâ19 school lockdowns and the short term impacts associated with these were not maintained over time. These findings should be considered in the context of this studyâs geographical location and the unpredictability of school lockdowns. Learning to live with school lockdowns into the future may be a critical element for further investigation in the context of interventions
Reciprocal relationships between trajectories of loneliness and screen media use during adolescence
Adolescence is the peak period for loneliness. Now a ubiquitous part of the adolescent landscape, electronic screens may provide avenues for ameliorating feelings of loneliness. Conversely, they may act as risk factors for the development of such feelings. Although cross-sectional studies to date have investigated the relationship between screen use and loneliness, longitudinal studies are needed if causal and directional associations are to be investigated. Utilising an accelerated longitudinal design and online survey we collected four waves of data from 1919 secondary school adolescents aged 10â15 years over two years. Random intercept cross-lagged panel models tested whether changes in five types of screen use (i.e., total screen time, social media use, gaming, passive screen use, and web use) are associated with changes in loneliness in the subsequent time-point, or changes in loneliness are associated with changes in screen use in the subsequent time-point. We found significant reciprocal associations between screen use and loneliness, with the strongest associations between social networking and electronic gaming and quality of friendships. These findings highlight that any significant increase in an adolescent's screen use may be a potential indicator of changes in quality of friendships or feelings of isolation
Image-Less THA Cup Navigation in Clinical Routine Setup: Individual Adjustments, Accuracy, Precision, and Robustness.
Background and Objectives: Even after the 'death' of Lewinnek's safe zone, the orientation of the prosthetic cup in total hip arthroplasty is crucial for success. Accurate cup placement can be achieved with surgical navigation systems. The literature lacks study cohorts with large numbers of hips because postoperative computer tomography is required for the reproducible evaluation of the acetabular component position. To overcome this limitation, we used a validated software program, HipMatch, to accurately assess the cup orientation based on an anterior-posterior pelvic X-ray. The aim of this study were to (1) determine the intraoperative 'individual adjustment' of the cup positioning compared to the widely suggested target values of 40° of inclination and 15° of anteversion, and evaluate the (2) 'accuracy', (3) 'precision', and (4) robustness, regarding systematic errors, of an image-free navigation system in routine clinical use. Material and Methods: We performed a retrospective, accuracy study in a single surgeon case series of 367 navigated primary total hip arthroplasties (PiGalileoTM, Smith+Nephew) through an anterolateral approach performed between January 2011 and August 2018. The individual adjustments were defined as the differences between the target cup orientation (40° of inclination, 15° of anteversion) and the intraoperative registration with the navigation software. The accuracy was the difference between the intraoperative captured cup orientation and the actual postoperative cup orientation determined by HipMatch. The precision was analyzed by the standard deviation of the difference between the intraoperative registered and the actual cup orientation. The outliers were detected using the Tukey method. Results: Compared to the target value (40° inclination, 15° anteversion), the individual adjustments showed that the cups are impacted in higher inclination (mean 3.2° ± 1.6°, range, (-2)-18°) and higher anteversion (mean 5.0° ± 7.0°, range, (-15)-23°) (p < 0.001). The accuracy of the navigated cup placement was -1.7° ± 3.0°, ((-15)-11°) for inclination, and -4.9° ± 6.2° ((-28)-18°) for anteversion (p < 0.001). Precision of the system was higher for inclination (standard deviation SD 3.0°) compared to anteversion (SD 6.2°) (p < 0.001). We found no difference in the prevalence of outliers for inclination (1.9% (7 out of 367)) compared to anteversion (1.63% (6 out of 367), p = 0.78). The Bland-Altman analysis showed that the differences between the intraoperatively captured final position and the postoperatively determined actual position were spread evenly and randomly for inclination and anteversion. Conclusion: The evaluation of an image-less navigation system in this large study cohort provides accurate and reliable intraoperative feedback. The accuracy and the precision were inferior compared to CT-based navigation systems particularly regarding the anteversion. However the assessed values are certainly within a clinically acceptable range. This use of image-less navigation offers an additional tool to address challenging hip prothesis in the context of the hip-spine relationship to achieve adequate placement of the acetabular components with a minimum of outliers
Modeling of pulsed laser guide stars for the Thirty Meter Telescope project
The Thirty Meter Telescope (TMT) has been designed to include an adaptive
optics system and associated laser guide star (LGS) facility to correct for the
image distortion due to Earth's atmospheric turbulence and achieve
diffraction-limited imaging. We have calculated the response of mesospheric
sodium atoms to a pulsed laser that has been proposed for use in the LGS
facility, including modeling of the atomic physics, the light-atom
interactions, and the effect of the geomagnetic field and atomic collisions.
This particular pulsed laser format is shown to provide comparable photon
return to a continuous-wave (cw) laser of the same average power; both the cw
and pulsed lasers have the potential to satisfy the TMT design requirements for
photon return flux.Comment: 16 pages, 20 figure
Room-Temperature Anomalous Hall Effect in Graphene in Interfacial Magnetic Proximity with EuO Grown by Topotactic Reduction
We show that thin layers of EuO, a ferromagnetic insulator, can be achieved
by topotactic reduction under titanium of a Eu2O3 film deposited on top of a
graphene template. The reduction process leads to the formation of a 7-nm thick
EuO smooth layer, without noticeable structural changes in the underlying
chemical vapor deposited (CVD) graphene. The obtained EuO films exhibit
ferromagnetism, with a Curie temperature that decreases with the initially
deposited Eu2O3 layer thickness. By adjusting the thickness of the Eu2O3 layer
below 7 nm, we promote the formation of EuO at the very graphene interface: the
EuO/graphene heterostructure demonstrates the anomalous Hall effect (AHE),
which is a fingerprint of proximity-induced spin polarization in graphene. The
AHE signal moreover persists above Tc up to 350K due to a robust
super-paramagnetic phase in EuO. This original high-temperature magnetic phase
is attributed to magnetic polarons in EuO: we propose that the high strain in
our EuO films grown on graphene stabilizes the magnetic polarons up to room
temperature. This effect is different from the case of bulk EuO in which
polarons vanish in the vicinity of the Curie temperature Tc= 69K.Comment: 29 page
Corynebacterium oculi-related bacterium may act as a pathogen and carrier of antimicrobial resistance genes in dogs: a case report.
BACKGROUND
The genus Corynebacterium comprises well-known animal and human pathogens as well as commensals of skin and mucous membranes. Species formerly regarded as contaminants are increasingly being recognized as opportunistic pathogens. Corynebacterium oculi has recently been described as a human ocular pathogen but has so far not been reported in dogs.
CASE PRESENTATION
Here we present two cases of infection with a novel Corynebacterium sp., a corneal ulcer and a case of bacteriuria. The two bacterial isolates could not be identified by MALDI-TOF MS. While 16Â S rRNA gene (99.3% similarity) and rpoB (96.6% identity) sequencing led to the preliminary identification of the isolates as Corynebacterium (C.) oculi, whole genome sequencing revealed the strains to be closely related to, but in a separate cluster from C. oculi. Antimicrobial susceptibility testing showed high minimal inhibitory concentrations of lincosamides, macrolides, tetracycline, and fluoroquinolones for one of the isolates, which also contained an erm(X) and tet-carrying plasmid as well as a nonsynonymous mutation leading to an S84I substitution in the quinolone resistance determining region of GyrA.
CONCLUSIONS
While the clinical signs of both dogs were alleviated by antimicrobial treatment, the clinical significance of these isolates remains to be proven. However, considering its close relation with C. oculi, a known pathogen in humans, pathogenic potential of this species is not unlikely. Furthermore, these bacteria may act as reservoir for antimicrobial resistance genes also in a One Health context since one strain carried a multidrug resistance plasmid related to pNG3 of C. diphtheriae
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