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Background The COVID-19 pandemic and related restrictions have affected the wellbeing of school children worldwide. Specific problems evolving during the pandemic, their extent and duration haveńt been sufficiently explored yet. We aimed at describing school childreńs psychosocial and behavioral parameters and associated factors during the COVID-19 pandemic in Berlin, Germany. Methods Our longitudinal study included students from 24 randomly selected Berlin primary and secondary schools, assessing psychosocial wellbeing and behaviors at four time points between June 2020 and March 2021. We analyzed temporal changes in the proportions of anxiety, fear of infection, reduced health-related quality of life (HRQoL), physical activity and social contacts, as well as sociodemographic and economic factors associated with anxiety, fear of infection and HRQoL. Results Of initially 384 recruited students, 324 still participated in the fourth study round after nine months. During the observation period, presence of anxiety symptoms increased from 26.2% (96/367) to 34.6% (62/179), and fear of infection from 28.6% (108/377) to 40.6% (73/180). The proportion of children with limited social contacts ( Conclusions A substantial proportion of school children experienced unfavorable psychosocial conditions during the COVID-19 pandemic in 2020/2021. In particular, students from households with limited social and financial resilience require special attention. Key messages

Outbreaks of Escherichia coli O157:H7 in the United States due to contaminated foods are a public health issue and a continuing problem. The major reservoir for these organisms is the gastrointestinal tract of ruminants where they are a member of the resident microbiota. Several factors that contribute to the colonization of cattle have been identified, but a systematic screen of genes that might contribute to the colonization and persistence phenotype in mature ruminants has not been reported. Using a sheep model of persistence, signature tagged mutagenesis (STM) was used to screen 1326 mutants for a persistence-negative phenotype of E. coli O157:H7. We identified 9 genes by STM that appeared to be required for colonization and/or survival in sheep. Three of the genes had functions associated with central metabolism (thiK, ftrA and nrdB), one was involved with LPS formation (wbdP), one encodes a non-LEE encoded effector protein (nleB) and one was a methyltransferase encoded on a prophage (Z2389). The remaining three genes did not have homology with any known genes. Six sheep given ΔwbdP and 2 sheep each were given mutants (ΔthiK (Z1745), ΔftrA (Z2164) and Z2389). The ΔwbdP mutant was recovered from the feces of 4/6 sheep at 6 days pi with a mean number of 1.42 log10 CFU/g feces compared to 4.6 log10 CFU/g feces for the wild type strain. This difference was significant (P

Schurks M, Glynn RJ, Rist PM, Tzourio C, Kurth T. Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials. BMJ 2010; 341: c5702.

A number of polymerase chain reaction (PCR)-based diagnostic tests have been developed for Mycoplasma hyopneumoniae, including one from this research group. This report presents further development, optimization, and standardization of a nested PCR test. Detection sensitivity was 1 fg of M. hyopneumoniae chromosomal DNA (approximately 1 organism). This exceeded the sensitivity of or compared favorably with other published PCR tests. Polymerase chain reaction primers to porcine β2-microglobulin were included as internal controls for amplifiable chromosomal DNA from porcine samples. To standardize the test, a number of samples from experimentally infected pigs, including nasal, tonsil, tracheobronchial swabs, lung tissue, bronchial alveolar lavage (BAL) fluid, and tracheobronchial brush samples, were examined by PCR. Samples obtained from BAL fluid and tracheobronchial sites were most predictive of infection, whereas nasal swabs and lung tissue were not reliable indicators of experimentally induced infection. In conclusion, the nested PCR developed for this study was found to be a highly sensitive and specific diagnostic tool for M. hyopneumoniae, but the enhanced sensitivity may be unnecessary if the proper sites are sampled.

Vertically stacked arrays of GaAs/(AlGa)As sidewall quantum wires (Qwires) were successfully fabricated on GaAs (311)A substrates patterned with 0.5 μm-pitch gratings. The Qwires exhibit a lateral confinement potential as large as 210 meV and high luminescence efficiency up to 300 K. The distinct carrier transfer and loss mechanisms are studied by temperature dependent, spectrally and spatially resolved cathodoluminescence. Despite the almost perfect carrier capture in the Qwires, non-radiative recombination within the connecting quantum well (Qwell) regions usually cannot be neglected even at low temperatures. For temperatures approaching 300 K, reemission of carriers out of the Qwell into the vertical (AlGa)As barriers contributes increasingly to the reduction of the carrier transfer and luminescence efficiency of the Qwires without notable repopulation of the connecting Qwells.

We review far-infrared experiments on quantum wires and dots. In particular, we show that with tailored deviations from a parabolic external lateral confinement potential one can break Kohn’s theorem. This allows a detailed investigation of the internal relative motion in quantum dots and wires and the study of electron–electron interaction effects, for example, the formation of compressible and incompressible states in quantum dots and antidots.

Double-layered antidot arrays have been prepared by deep mesa etching of modulation-doped Al x Ga 1− x As GaAs double-quantum-wells. In far infra-red transmission spectroscopy we observe a rich mode spectrum arising from collective optical (in phase) and acoustic (out of phase) oscillation in the two layers. In a magnetic field we find huge filling factor dependent oscillations of the frequency of the edge magnetoplasmon modes which are caused by self-consistent screening of the edge potential.

Electronic excitations in AlGaAs-GaAs quantum wires have been investigated by means of resonant inelastic light scattering. Besides a rich spectrum of 1D electronic excitations at low frequencies we fin d at higher frequencies transitions in the regime of the original 2D intersubband excitations. Interestingly, we observe not only the original 2D intersubband excitations but additional modes ωk in polarized scattering geometry. The experimental observation is that the frequencies of these modes obey the relationship, ω2k = ω22D + ω21D, where ω2D is the vertical intersubband plasmon frequency and ω1D the lateral confined plasmon frequency. This relationship suggests that the additional modes are combined 2D-1D intersubband excitations of collective charge-density type.

We study the spectra of heavy-light and heavy-heavy mesons containing charm quarks, including higher spin states. We use two sets of $N_f = 2 + 1$ gauge configurations, one set from QCDSF using the SLiNC action, and the other configurations from the Budapest-Marseille-Wuppertal collaboration, using the HEX smeared clover action. To extract information about the excited states, we choose a suitable basis of operators to implement the variational method.

Three-dimensional arrays of vertically stacked sidewall quantum wires are fabricated by molecular beam epitaxy on GaAs (311)A substrates patterned with 500-nm-pitch gratings. The cathodoluminescence spectra at low temperature are dominated by the emission from the quantum wires with narrow linewidth accompanied by a very weak emission from the connecting thin quantum wells due to localization of excitons at random interface fluctuations. When the carriers in the quantum well become delocalized at elevated temperature, only the strong emission from the quantum-wire array is observed revealing perfect carrier capture into the quantum wires without detectable thermal repopulation of the quantum well up to room temperature. Thus, unpreceded device quality of this quantum-wire structure is demonstrated.

Summary Objective In a recent study, we demonstrated that mesenchymal stem cells (MSCs) derived from the synovial membranes of bovine shoulder joints could differentiate into chondrocytes when cultured in alginate. The purpose of the present study was to establish the conditions under which synovial MSCs derived from aging human donors can be induced to undergo chondrogenic differentiation using the same alginate system. Methods MSCs were obtained by digesting the knee-joint synovial membranes of osteoarthritic human donors (aged 59–76 years), and expanded in monolayer cultures. The cells were then seeded at a numerical density of 4×10 6 /ml within discs of 2% alginate, which were cultured in serum-containing or serum-free medium (the latter being supplemented with 1% insulin, transferrin, selenium (ITS). The chondrogenic differentiation capacity of the cells was tested by exposing them to the morphogens transforming growth factor-beta1 (TGF-β1), TGF-β2, TGF-β3, insulin-like growth factor-1 (IGF-1), bone morphogenetic protein-2 (BMP-2) and BMP-7, as well as to the synthetic glucocorticoid dexamethasone. The relative mRNA levels of collagen types I and II, of aggrecan and of Sox9 were determined quantitatively by the real-time polymerase chain reaction (PCR). The extracellular deposition of proteoglycans was evaluated histologically after staining with Toluidine Blue, and that of type-II collagen by immunohistochemistry. Results BMP-2 induced the chondrogenic differentiation of human synovial MSCs in a dose-dependent manner. The response elicited by BMP-7 was comparable. Both of these agents were more potent than TGF-β1. A higher level of BMP-2-induced chondrogenic differentiation was achieved in the absence than in the presence of serum. In the presence of dexamethasone, the BMP-2-induced expression of mRNAs for aggrecan and type-II collagen was suppressed; the weaker TGF-β1-induced expression of these chondrogenic markers was not obviously affected. Conclusions We have demonstrated that synovial MSCs derived from the knee joints of aging human donors possess chondrogenic potential. Under serum-free culturing conditions and in the absence of dexamethasone, BMP-2 and BMP-7 were the most potent inducers of this transformation process.

We present an electrostatic model to determine the surface charge density and confinement potential in etched AlGaAs/GaAs quantum wires. In far-infrared transmission experiments we have determined the resonance frequencies of the dynamic eigenmodes of the quantum wire, which gives an independent determination of the confinement potential. We find good agreement with the modeled potential, which shows that this model gives a very good description of the electronic system.

Aim of the study was to translate the original version of the Barthel-Index (BI) into German and to investigate the reliability of the German version. In addition, a German version of the BI for postal and telephone use was developed.Data were collected in four neurological hospitals in Germany. The translation of the BI followed the protocol of the Medical Outcomes Trust. The interrater reliability of the German version of the BI was investigated in 72 patients after acute stroke. The reliability of the postal and telephone version of the BI was compared with face-to-face interview in 147 patients three months after stroke. Reliability was assessed using simple weighted kappa-statistics.The interrater reliability of the German version of the BI was excellent (mean kappa 0.93). The mean kappa coefficient was 0.79 for the postal version of the BI and 0.80 for the telephone version. Thus, the agreement between the postal and the telephone administration of the BI compared to the face-to-face interview was substantial to excellent.Our study published the first German version of the BI which was investigated for interrater reliability in a standardized way. The development of a postal and a telephone version allows the widespread use of the German BI for the follow up of stroke patients in different access paths.

Myplasma gallisepticum infects a wide variety of gallineaceous birds including chickens, turkeys, and pheasants. Infection occurs both horizontally and vertically. Thus, control of the spread of M. gallisepticum to noninfected flocks is difficult. Continual monitoring is necessary to identify infected flocks even under the most stringent infectious control practices. Monitoring, however, is usually performed by measuring hemagglutination activity (HA) in serum, an insensitive and variable test. Variability in the HA test arises differences in agglutination antigen, changes in antigenic profiles of the M. gallisepticum strain, and variability in reading the agglutination reaction. Enzyme-linked immunosorbent assays (ELISAs) are the preferred method of testing because of the ease in obtaining sera and the sensitivity and reproducibility of the assays, but the ELISA suffers from a lack of standardization in the test antigen. The ELISA test will be more easily accepted once the test antigen has been standardized. To this end, we have identified, cloned, and characterized the gene for an antigen that has potential as a species-specific antigen for M. gallisepticum The gene codes for a 75-kD protein, P75, that is recognized during natural infections. Recombinant P75 is not recognized in immunoblots by convalescent sera produced in chickens infected with Mycoplasma synoviae, Mycoplasma gallinarum, and Mycoplasma gallinaceum or in turkeys infected with Mycoplasma meleagridis.

The industrial application of model predictive control (MPC) has been largely confined to the petrochemical arena. Crossover into the general process industries has been limited. Among the reasons that may be proposed for this can be highlighted: (i) a lack of precedent applications, (ii) large engineering costs, (iii) inappropriate control technologies. This paper describes initiatives to address such barriers so that the benefits of MPC can be more widely available: (i) demonstration projects on mainstream process applications, (ii) software tools to minimise engineering costs, (iii) embedding MPC within the plant regulatory control system, (iv) a flexible approach to control technology so that solutions match the problem encountered rather than the other way round.

Linkage of cadherins to the cytoskeleton is crucial for their adhesive function. Since alpha- and beta-catenin play a key role in this linkage, these proteins are possible targets for processes that control cell-cell adhesion. To achieve a better understanding of the regulation of cell-cell adhesion in embryonic morphogenesis, we used immunohistology to investigate how in Xenopus blastomeres catenins respond to disturbances in the expression of maternal cadherins. Overexpression of myc-tagged maternal cadherin leads to a proportionate increase of the level of beta-catenin. The two proteins colocalize in the endoplasmic reticulum, in cytoplasmic vesicles, and along the cell membrane, indicating that the beta-catenin binds to overexpressed cadherin early in its passage to the plasma membrane. Expression of cadherin is essential for the stable presence of beta-catenin, as depletion from maternal cadherin mRNA leads to a complete loss of beta-catenin from the blastomeres. alpha-Catenin behaves differently. Overexpression of cadherin leaves the amount and localization of alpha-catenin largely unaffected, and additional cadherin inserts itself into the membrane without a proportionate rise in the level of membrane-bound alpha-catenin. However, cadherin mRNA depletion leads to a redistribution of alpha-catenin from the membrane to the cytoplasm. Thus, cadherin is required to localize alpha-catenin to the membrane, but the amount of alpha-catenin along the membrane seems to be restricted to a certain level which cannot be exceeded. The relevance of these observations for the regulation of cadherin-mediated cell adhesion in the Xenopus embryo is discussed. Additionally, we demonstrate that plakoglobin, like beta-catenin an armadillo repeat protein, shows neither accumulation after overexpression nor colocalization with the overexpressed cadherin.

We have investigated experimentally and theoretically the far-infrared (FIR) absorption of gated, deep-mesa-etched GaAs/Al$_x$Ga$_{1-x}$As quantum wires. To overcome Kohn's theorem we have in particular prepared double-layered wires and studied the acoustic magnetoplasmon branch. We find oscillations in the magnetic-field dispersion of the acoustic plasmon which are traced back to the self-consistently screened density profile in its dependence on the magnetic depopulation of the one-dimensional subbands., LaTeX-file, 4 pages with 3 included ps-figures, to appear in Physica E

The excitation of magnetoplasmons in ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As-GaAs quantum dots and wires with far-infrared transmission spectroscopy is investigated. An interaction of the magnetoplasmon resonance with harmonics of the cyclotron resonance n${\mathrm{\ensuremath{\omega}}}_{\mathit{c}}$ (n=2,3) is observed. Results of self-consistent calculations of the magnetoplasmon dispersion show similar effects when the lateral confinement of the electrons has a slight deviation from a parabolic form. Comparison of the results indicates a good qualitative agreement between experiments and models.

The application of the compound parabolic concentrator (CPC) for use with solar cells has been investigated. Experiments with state-of-the-art Si cells in a CPC and under solar concentration were performed. A theoretical model for calculating the behavior of Si solar cells with concentration was developed. Detailed calculations of the energy distribution in the CPC were made. Finally a cost effectiveness analysis shows that the CPC system will produce power at very much lower cost than will flat panel solar cell arrays. (auth)

International audience; Introduction: Migraine and combined hormonal contraceptives (CHCs) increase the risk of ischemic stroke in young women; however, the contribution of low-dose (

Schistosomiasis; Travelers and migrants; Europe Esquistosomosi; Viatgers i migrants; Europa Esquistosomiasis; Viajeros y migrantes; Europa Schistosomiasis remains one of the most prevalent parasitic diseases worldwide and the infection is frequently found in travelers and migrants. The European Network for Tropical Medicine and Travel Health conducted a sentinel surveillance study on imported schistosomiasis between 1997 and 2010. This report summarizes epidemiological and clinical data from 1,465 cases of imported schistosomiasis. Direct pathogen detection and serology were the main diagnostic tools applied. Of these, 486 (33%) cases were identified among European travelers, 231 (16%) among long-term expatriates, and 748 (51%) among non-European immigrants. Overall, only 18.6% of travelers had received pretravel advice; 95% of infections were acquired in the African region. On species level, Schistosoma mansoni was identified in 570 (39%) and Schistosoma haematobium in 318 (22%) cases; 57.5% of patients were symptomatic. Acute symptoms were reported in 27% of patients leading to earlier presentation within 3 months. Praziquantel was used in all patients to treat schistosomiasis. Many infections were detected in asymptomatic patients. In 47.4% of asymptomatic patients infection was detected by microscopy and in 39% by serology or antigen testing. Schistosomiasis remains a frequent infection in travelers and migrants to Europe. Travelers should be made aware of the risk of schistosomiasis infection when traveling to sub-Saharan Africa. Posttravel consultations particularly for returning expatriates are useful given the high potential for detecting asymptomatic infections.

ObjectivesWe assessed virological outcomes of darunavir use in France from 2012 to 2016, in three groups of people living with HIV (PLHIV): (i) antiretroviral (ARV)-naive PLHIV; (ii) ARV-experienced PLHIV switching to darunavir while failing therapy; and (iii) ARV-experienced PLHIV switching to darunavir while virologically controlled.MethodsVirological success (VS) was defined as a plasma HIV-1 viral load (VL) 50 copies/mL or one VL >50 copies/mL followed by a treatment switch prior to the next VL measurement. The cumulative incidence of VS was assessed considering darunavir discontinuation, loss to follow-up and death as competing risks, while estimates of cumulative incidence of VF accounted for loss to follow-up and death.ResultsAmong the 3235 ARV-naive PLHIV initiating darunavir, the 4 year cumulative incidence of VS was 80.9% and was associated with lower VL and higher CD4 cell counts. Among the 3485 ARV-experienced PLHIV switching to darunavir while failing therapy, the 4 year cumulative incidence of VS was 82.2% and was associated with lower VL. Among the 3005 ARV-experienced PLHIV switching to darunavir while virologically controlled, the 4 year cumulative incidence of VF was 12.6%. The risk of VF was higher with darunavir monotherapy [subdistribution hazard ratio (sHR)=1.67, 95% CI 1.15–2.42] while no difference was observed with dual therapy (sHR = 1.00, 95% CI 0.71–1.42) relative to triple therapy or more.ConclusionsDarunavir-containing regimens yielded similarly high rates of viral suppression in PLHIV whether they were ARV naive or ARV experienced switching to darunavir while failing therapy, or of maintaining VS in ARV-experienced PLHIV switching to darunavir while virologically controlled.