Measurement of polarization observables T, P, and H in π0 and η photoproduction off quasi-free nucleons

The target asymmetry T, recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π 0 and η photoproduction off quasi-free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π 0 p and γ p → η p reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the η n system at W = 1.68 GeV . A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S 11 ( 1535 ) and S 11 ( 1650 ) resonances within the S 11 -partial wave.

Recruitment of epitope-specific T cell clones with a low-avidity threshold supports efficacy against mutational escape upon re-infection

Repetitive pathogen exposure leads to the dominant outgrowth of T cell clones with high T cell receptor (TCR) affinity to the relevant pathogen-associated antigens. However, low-affinity clones are also known to expand and form immunological memory. While these low-affinity clones contribute less immunity to the original pathogen, their role in protection against pathogens harboring immune escape mutations remains unclear. Based on identification of the TCR repertoire and functionality landscape of naive epitope-specific CD8⁺ T cells, we reconstructed defined repertoires that could be followed as polyclonal populations during immune responses in vivo. We found that selective clonal expansion is governed by clear TCR avidity thresholds. Simultaneously, initial recruitment of broad TCR repertoires provided a polyclonal niche from which flexible secondary responses to mutant epitopes could be recalled. Elucidating how T cell responses develop "from scratch" is informative for the development of enhanced immunotherapies and vaccines.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

The use of online video consultations in the aftercare of orthopedic patients: a prospective case-control study

Background

Video consultations have proven to be an efficient source of support for patient-doctor interactions and have become increasingly used in orthopedics, especially during the COVID-19 pandemic. This study analyzed both patients’ and doctors’ acceptance of an orthopedic telemedical consultation (OTC) and compared the results of OTC examinations to the results of live consultation (LC) to identify discrepancies.

Methods

The study was carried out in an orthopedic department of a German hospital between 2019 and 2020. After written informed consent was obtained, patients voluntarily presented for follow-up by OTC and LC. The experience with and attitudes toward OTC among both patients and doctors was evaluated (using Likert scale-scored and open questions, 26 to 28 items). The results of the OTC and LC examinations were compared using a 12-item checklist. The data were analyzed by quantitative and qualitative statistics.

Results

A total of 53 patients were included, each of whom completed an OTC and an LC. The OTC was rated as pleasant, and the experience was rated as very satisfying (average rating on a 5-point Likert scale, with 1 indicating strong agreement: doctors: 1.2; patients: 1.3). Various technical and organizational challenges were identified. Compared to LC, OTC showed no significant differences in patient history or in inspection, palpation, or active range of motion results. Only for the functional or passive joint assessment did LC show significantly higher suitability (p < 0.05) than OTC. Recommendations for further procedures did not differ significantly between OTC and LC.

Conclusions

Because of the high acceptance and the objective benefits of OTC and the similarity of clinical results with LC, OTC is recommendable for orthopedic follow-up examinations. To better assess joint functionality, meaningful digital alternatives for established examination methods should be further investigated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04653-3.

Acoustically Induced Vocal Training for Individuals With Impaired Hearing

OBJECTIVES/HYPOTHESIS

Articulation, phonation, and resonance disorders in the speech of hearing-impaired-speakers reduces intelligibility. The study focusses on (1) whether nonacoustic feedback may facilitate the adjustment of the vocal tract, leading to increased vocal tract resonance, and (2) whether training with the feedback would be helpful for the subsequent formation of vowels.

STUDY DESIGN

Prospective.

METHODS

Seven profoundly hearing-impaired participants used acoustic sound waves in the frequency range of the first two vocal tract resonances applied in front of the open mouth at intensities above 1 Pa. They were asked to amplify the sound via adjusting the vocal tract. The sound waves corresponded to the first and second resonance frequencies of the vowels [u], [o], and [a]. The self-assessment of the participants and a software-based/auditory analysis was reported.

RESULTS

The participants were able to enhance the acoustic signal by adjusting the vocal tract shape. The self-perception of the participants, the auditory voice analysis, and the acoustic analysis of vowels were consistent with each other. While the maximum sound pressure levels were constant, the mean sound pressure levels increased. Breathiness and hoarseness declined during the exercises. Resonance/harmonic-to-noise ratio increased, especially for the vowels [u], [o], [a]. Furthermore, the positively connoted feedback from the participants indicated easier sound production.

CONCLUSION

Nonauditory feedback, based on acoustic waves, could be suitable for improving the formation of vowels. The findings are in accordance with a reduction of acoustic losses within the vocal tract.

Biologic drug survival rates in the era of anti-interleukin-17 antibodies: a time-period-adjusted registry analysis

Background

Drug survival rates reflect efficacy and safety and may be influenced by the availability of alternative treatment options. Little is known about time‐dependent drug survival in psoriasis and the effect of increasing numbers of biologic treatment options.

Objectives

To determine whether drug survival is influenced by the availability of treatment options and by factors such as gender, psoriatic arthritis or previous biologic treatment.

Methods

This observational, retrospective, multicentre cohort study analysed data from patients registered in the Austrian Psoriasis Registry (PsoRA) who were treated with biologics between 1 January 2015 and 30 November 2019.

Results

A total of 1572 patients who received 1848 treatment cycles were included in this analysis. The highest long‐term Psoriasis Area and Severity Index improvement was observed after treatment with ixekizumab, followed by ustekinumab and secukinumab, adalimumab and etanercept. Overall, ustekinumab surpassed all other biologics in drug survival up to 48 months. However, when adjusted for biologic naïvety, its superiority vanished and drug survival rates were similar for ixekizumab (91·6%), secukinumab (90·2%) and ustekinumab (92·8%), all of them superior to adalimumab (76·5%) and etanercept (71·9%) at 12 months and beyond. Besides biologic non‐naïvety (2·10, P < 0·001), the introduction of a new drug such as secukinumab or ixekizumab (relative hazard ratio 1·6, P = 0·001) and female gender (1·50, P = 0·019) increased the risk of treatment discontinuation overall, whereas psoriatic arthritis did not (1·12, P = 0·21).

Conclusions

The time‐dependent availability of drugs should be considered when analysing and comparing drug survival. Previous biologic exposure significantly influences drug survival. Women are more likely to stop treatment.

What is already known about this topic?

Female gender and previous biologic exposure have been discussed as predictors for decreased drug survival in patients with psoriasis, but it remains unknown whether a time‐dependent increased availability of treatment options alters biologic drug survival.

What does this study add?

The increased availability of alternative biologic treatments over time leads to an elevated risk for treatment discontinuation overall; therefore, drug survival analysis has to be time adjusted.

Moreover, the study reveals that the impact of previous biologic treatment on drug survival is tremendous and confirms worse drug survival in female patients.

Linked Comment: Gniadecki. Br J Dermatol 2021; 184:996–997.

Observation of the pη^{'} Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748  MeV to W=2045  MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447  MeV (W=1896  MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

Water, sanitation, and hygiene (WASH) factors associated with growth between birth and 1 year of age in children in Soweto, South Africa: results from the Soweto Baby WASH study

Interventions to reduce undernutrition and improve child growth have incorporated improved water, sanitation, and hygiene (WASH) as part of disease transmission prevention strategies. Knowledge gaps still exist, namely, when and which WASH factors are determinants for growth faltering, and when WASH interventions are most effective at improving growth. This study drew cross-sectional data from a longitudinal cohort study and used hierarchical regression analyses to assess associations between WASH factors: water index, sanitation, hygiene index, and growth: height-for-age (HAZ), weight-for-age (WAZ), weight-for-height (WHZ) at 1, 6, and 12 months postpartum among infants a priori born healthy in Soweto, Johannesburg. Household access to sanitation facilities that were not safely managed was associated with a decrease in HAZ scores at 1 month (β = -2.24) and 6 months (β = -0.96); a decrease in WAZ at 1 month (β = -1.21), 6 months (β = -1.57), and 12 months (β = -1.92); and finally, with WHZ scores at 12 months (β = -1.94). Counterintuitively, poorer scores on the hygiene index were associated with an increase at 1 month for both HAZ (β = 0.53) and WAZ (β = 0.44). Provision of safely managed sanitation at household and community levels may be required before improvements in growth-related outcomes are obtained.

Adjustment of Vocal Tract Shape via Biofeedback: Influence on Vowels

The study assessed 30 nonprofessional singers to evaluate the effects of vocal tract shape adjustment via increased resonance toward an externally applied sinusoidal frequency of 900 Hz without phonation. The amplification of the sound wave was used as biofeedback signal and the intensity and the formant position of the basic vowels /a/, /e/, /i/, /o/, and /u/ were compared before and after a vocal tract adjustment period. After the adjustment period, the intensities for all vowels increased and the measured changes correlated with the participants' self-perception.The diferences between the second formant position of the vowels and the applied frequency influences the changes in amplitude and in formant frequencies. The most significant changes in formant frequency occurred with vowels that did not include a formant frequency of 900 Hz, while the increase in amplitude was the strongest for vowels with a formant frequency of about 900 Hz.

Production, deformation and mechanical investigation of magnetic alginate capsules

In this article we investigated the deformation of alginate capsules in magnetic fields. The sensitivity to magnetic forces was realised by encapsulating an oil in water emulsion, where the oil droplets contained dispersed magnetic nanoparticles. We solved calcium ions in the aqueous emulsion phase, which act as crosslinking compounds for forming thin layers of alginate membranes. This encapsulating technique allows the production of flexible capsules with an emulsion as the capsule core. It is important to mention that the magnetic nanoparticles were stable and dispersed throughout the complete process, which is an important difference to most magnetic alginate-based materials. In a series of experiments, we used spinning drop techniques, capsule squeezing experiments and interfacial shear rheology in order to determine the surface Young moduli, the surface Poisson ratios and the surface shear moduli of the magnetically sensitive alginate capsules. In additional experiments, we analysed the capsule deformation in magnetic fields. In spinning drop and capsule squeezing experiments, water droplets were pressed out of the capsules at elevated values of the mechanical load. This phenomenon might be used for the mechanically triggered release of water-soluble ingredients. After drying the emulsion-filled capsules, we produced capsules, which only contained a homogeneous oil phase with stable suspended magnetic nanoparticles (organic ferrofluid). In the dried state, the thin alginate membranes of these particles were rather rigid. These dehydrated capsules could be stored at ambient conditions for several months without changing their properties. After exposure to water, the alginate membranes rehydrated and became flexible and deformable again. During this swelling process, water diffused back in the capsule. This long-term stability and rehydration offers a great spectrum of different applications as sensors, soft actuators, artificial muscles or drug delivery systems.

First trimester antenatal depression and anxiety: prevalence and associated factors in an urban population in Soweto, South Africa

Depression and anxiety in the antenatal period are of public health concern given potential adverse effects for both mother and infant. Both are under-researched in the first trimester of pregnancy, especially in Africa. We examine the prevalence of first trimester antenatal depression and anxiety in a cohort of South African women and investigate associated risk factors. Data were collected from 946 women (2014-2016) in the Soweto First 1000 Days Cohort, a prospective pregnancy cohort in Soweto, South Africa. Antenatal depression was assessed using the Edinburgh Postnatal Depression Scale with a score of ⩾13 indicating probable depression. Anxiety was assessed using the short form of the State-Trait Anxiety Index with a score ⩾12 indicating probable anxiety. Prevalence of antenatal depression was 27% [95% confidence interval (CI) 24.2-29.8] and anxiety 15.2% (95% CI 12.9-17.5). Factors associated with antenatal depression and anxiety were predominantly relationship- and family-centred. Women who perceived that their partner made life harder for them had three-fold increased odds for depression [(odds ratio (OR) 3.33 [2.28-4.85] P<0.001], whereas those with family stressors had almost double the odds for depression (OR 1.78 [1.22-2.59] P=0.003) and anxiety (OR 1.75 [1.44-2.69] P=0.0011). Antenatal depression and anxiety are common in the first trimester of pregnancy, and partner and family relationship stressors are central. Longitudinal analysis is needed to determine if this is a phase of adjustment to pregnancy or onset of persistent symptomology. Early intervention may have secondary preventative effects and should involve the partner and family.

The South African universal preschool year: a case study of policy development and implementation

BACKGROUND

South Africa is the first sub-Saharan African country to legislate, fund and implement free preschool education. Human rights and restitution were at the forefront of the political struggle for democracy in South Africa. Levelling the playing fields by improving the school readiness of children disadvantaged by the racist policies of Apartheid is essential to the transformation of South African society.

METHODS

A review of published and unpublished documents on Grade R was undertaken, and access and enrolment data come from the National Department of Basic Education's Education Management Information System (EMIS).

RESULTS

A decade after initiation in 2005, 79% of 5-year-olds was enrolled in a preschool class; the vast majority of them in free public schools. Grade R is near universal and on track to becoming compulsory. It is part of the Foundation Phase (Grades 1-3) of schooling, falling under the Department of Basic Education, but also part of a broader national strategy to improve early child development under the direction of an Inter-Departmental Steering. Evaluations demonstrate wide access to Grade R and high uptake, especially in the poorest areas. However, the quality of Grade R provision in these areas is not up to standard because of low levels of funding; inadequate training, supervision, remuneration and retention of Grade R teachers; insufficient learner support materials; and inadequate monitoring and quality assurance.

CONCLUSIONS

Lack of quality, amongst other factors, contributes to a widening school performance gap between children from more and less privileged areas. Quality of Grade R as well as earlier learning and subsequent years of schooling must be improved to achieve South Africa's aim to reduce poverty and inequality through, amongst others, parent and family involvement, learning in the home and preschool preparation.

[Systemic lupus erythematosus : Unusual cutaneous manifestations]

BACKGROUND

Various different mucocutaneous symptoms may affect up to 80 % of systemic lupus erythematosus (SLE) patients.

OBJECTIVES

To investigate, various unspecific, but otherwise typical clinical symptoms of skin and mucous membranes that arise in SLE patients other than those defined as SLE criteria such as butterfly rash, chronic cutaneous lupus erythematosus, oral ulcers, and increased photosensitivity.

MATERIALS AND METHODS

Extensive search of peer-reviewed scientific articles was performed, medical histories of several SLE patients seen in our department were analyzed, and the rare disease courses in three SLE patients are presented.

RESULTS

Here we present a variety of unspecific but typical mucocutaneous manifestations in SLE patients: periungual erythema, periungual telangiectasia and periungual splinter hemorrhage, papules on the dorsum of the hands, scaling erythema, sometimes associated with necrosis, especially of the ears, along with complement deficiency, and the bizarre necroses of antiphospholipid syndrome. Furthermore, we show the typical clinico-histological features of neutrophilic urticarial dermatosis, as well as those of bullous SLE and finally a severe course of bacterial sepsis with Neisseria flavescens/macacae.

CONCLUSIONS

Here we show several unspecific but rather typical mucocutaneous symptoms in lupus patients that are indicative of SLE and thus may lead to an early diagnosis. Also, life-threatening bacterial sepsis may occur with microorganisms that are commonly considered "apathogenic", such as Neisseria flavescens/macacae, which exclusively affect immunosuppressed patients.

[Cutaneous involvement in chronic inflammatory bowel disease : Crohn's disease and ulcerative colitis]

BACKGROUND

Over recent decades, both the incidence and prevalence of chronic inflammatory bowel disease have continued to rise in industrialized countries; the disease is frequently associated with extracutaneous involvement and comorbidity.

OBJECTIVES

The purpose of this work was to investigate the frequency and specificity of mucocutaneous manifestations in Crohn's disease (CD) and ulcerative colitis (UC).

MATERIALS AND METHODS

An extensive search in peer-reviewed journals via PubMed was performed; presented is a summary and analysis of various studies and data, including data of patients treated at our department.

RESULTS

CD and UC are frequently associated with mucocutaneous symptoms; however, primary/specific disease-associations are exclusively seen in CD patients. These include peri-anal and -stomal fistulas and ulcerations, "metastatic" Crohn's disease as well as oral granulomatous disease. Moreover, in both CD and UC, there occur several other inflammatory skin conditions such as erythema nodosum, pyoderma gangrenosum, hidradenitis suppurativa, chronic oral aphthous disease, Sweet syndrome, pyostomatitis vegetans, and bowel-associated dermatosis-arthritis syndrome. Malnutrition syndromes (zinc and vitamin deficiencies) are only rarely observed.

CONCLUSION

On skin and oral/genital mucous membranes various different inflammatory manifestations may be observed during the course of CD or UC. However, most data about a direct pathogenic relationship of the gastrointestinal and dermatologic disorders are quite heterogeneous or even contradictory. Nevertheless, knowledge of these conditions and their possible association with CD and UC could be crucial for early diagnosis and initiation of an appropriate therapy and thus be essential to prevent secondary tissue damage.

Use of the ages and stages questionnaire adapted for South Africa and Zambia

BACKGROUND

There are few readily available, relatively easy to use and culturally adaptable developmental assessment tools for young children in southern Africa. The overarching aim of this study is to test the psychometric properties, contextual appropriateness and cut-off scores across 21 age groups of the Ages and Stages Questionnaire Third Edition (Squires & Bricker, ) among a group of typically developing children in South Africa and Zambia through a combination of both caregiver-report and direct observations, and to compare children's performance across sociodemographic variables.

METHODS

The sample consisted of 853 children (50.5% Zambia, with 50.1% girls for Zambia and 50% girls for South Africa) aged 2 months to 60 months. Information on caregiver employment, education and household assets were also obtained.

RESULTS

The psychometric properties of the ASQ-3 in southern Africa are consistent with those found in the extant literature. Analysis of item difficulty at each age reveals adequate levels of difficulty for majority of the items, with exception of the problem solving domain where half of the items at 54 and 60 months have poor pass rates. Sociodemographic variables were significantly associated with children's performance: higher caregiver levels of education are associated with higher toddler scores on the personal-social domain and higher preschooler scores on the problem solving domain; children whose caregivers earn a salary have higher fine motor scores during toddlerhood and higher problem solving scores during preschool and children who attend preschools have higher gross motor scores during toddlerhood and higher fine motor scores during the preschool years.

CONCLUSIONS

Findings provide evidence to support the psychometric properties and feasibility of using the ASQ-3 in both South Africa and Zambia through a combination of caregiver-report and direct observations.

Early sexual debut: Voluntary or coerced? Evidence from longitudinal data in South Africa--the Birth to Twenty Plus study

BACKGROUND

Early sexual debut, voluntary or coerced, increases risks to sexual and reproductive health. Sexual coercion is increasingly receiving attention as an important public health issue owing to its association with adverse health and social outcomes.

OBJECTIVE

To describe voluntary and coerced experience at sexual debut.

METHODS

A longitudinal perspective among 2,216 adolescents (1,149 females, 1,067 males) in a birth cohort study in South Africa, analysing data collected on six occasions between 11 and 18 years.

RESULTS

The median age of sexual debut was 16 years for females and 15 for males. Reported coerced sexual debut included children < 11 years of age. Males reported earlier sexual debut with both voluntary and coerced sexual experience, than females (p < 0.0001). Sexual coercion at early sexual debut among both male and female adolescents occurred mostly through sexual intercourse with older adolescents and partners of the same age.

CONCLUSION

The identified time periods and age groups need to be targeted for interventions to delay sexual debut and prevent sexual coercion among young people. More research is needed to understand underlying predisposing risk factors for sexual coercion at sexual debut, both early and not early.

Adalimumab in the treatment of moderate-to-severe chronic plaque psoriasis in patients switching from other biologics

BACKGROUND

Ample evidence shows that switching from one biological agent to another may prove effective when response to the first one is inadequate. Nevertheless, there are little data so far showing the efficacy and safety of adalimumab in patients with plaque psoriasis who previously received another biologic agent.

OBJECTIVE

We evaluated the 1-year effectiveness, safety and quality-of-life outcomes patients with psoriasis who had switched to adalimumab from other biologic therapies.

METHODS

Forty-two patients who participated in this Austrian multicenter study were treated with adalimumab over a 1-year period, after switching from efalizumab, infliximab or etanercept. Effectiveness was assessed using standardized tools for measurement of disease severity [Psoriasis Area and Severity Index (PASI) and Nail Psoriasis Severity Index (NAPSI)] and quality of life [Dermatology Life Quality Index (DLQI)]. The study endpoints were evaluated using the all-treated population.

RESULTS

The mean percentage of improvement at the end of the study was 74.3% for PASI, 81.6% for DLQI and 83.6% for NAPSI, demonstrating a considerable benefit of treatment with adalimumab. The safety profile observed was consistent with previous clinical trials for adalimumab, and no new safety signals were observed.

CONCLUSION

Adalimumab therapy in patients with plaque psoriasis previously treated with other biologic agents demonstrates effectiveness, safety and improvement in quality of life.

The association between stunting and psychosocial development among preschool children: a study using the South African Birth to Twenty cohort data

BACKGROUND

A large literature in developing countries finds a strong association between stunting in early childhood and educational attainment and/or cognitive performance among children of school-going age. We contribute to the literature on the effects of stunting in childhood by exploring the links between linear growth retardation and measures of development among preschool-aged children.

METHODS

We analyse the association between stunting (height-for-age z-score <-2) at age 2 years and children's scores on the Vineland Social Maturity Scale (VSMS) at age 4 years, a measure of social competence or 'daily living skills', and the Revised-Denver Prescreening Developmental Questionnaire (R-DPDQ) at age 5 years, a test which places greater emphasis on cognitive functioning. The sample is drawn from the Birth to Twenty cohort study, a prospective dataset of children born in 1990 in urban South Africa. We conduct multivariate regression analysis controlling for socio-economic status, various child-specific characteristics, home environment and caregiver inputs.

RESULTS

No significant association between stunting and children's performance on the VSMS, but a large and significant association with the R-DPDQ scores, was found. A disaggregated analysis of the various components of the scores suggests that children with low height-for-age at 2 years do not fall behind in terms of daily living skills or social maturity, but do substantially worse on measures capturing higher order fine motor skills and cognitive functioning.

CONCLUSIONS

Stunting in early childhood is strongly related to impaired cognitive functioning in children of preschool age, but does not seem to affect social maturity, at least as measured by the VSMS. These relationships between stunting at 2 years and psychosocial development at 4 and 5 years hold with extensive controls for socio-economic status, home environment, caregiver inputs and child characteristics included in the multivariate analysis.

Tracking post-error adaptation in the motor system by transcranial magnetic stimulation

The commission of an error triggers cognitive control processes dedicated to error correction and prevention. Post-error adjustments leading to response slowing following an error ("post-error slowing"; PES) might be driven by changes in excitability of the motor regions and the corticospinal tract (CST). The time-course of such excitability modulations of the CST leading to PES is largely unknown. To track these presumed excitability changes after an error, single pulse transcranial magnetic stimulation (TMS) was applied to the motor cortex ipsilateral to the responding hand, while participants were performing an Eriksen flanker task. A robotic arm with a movement compensation system was used to maintain the TMS coil in the correct position during the experiment. Magnetic pulses were delivered over the primary motor cortex ipsilateral to the active hand at different intervals (150, 300, 450 ms) after correct and erroneous responses, and the motor-evoked potentials (MEP) of the first dorsal interosseous muscle (FDI) contralateral to the stimulated hemisphere were recorded. MEP amplitude was increased 450 ms after the error. Two additional experiments showed that this increase was neither associated to the correction of the erroneous responses nor to the characteristics of the motor command. To the extent to which the excitability of the motor cortex ipsi- and contralateral to the response hand are inversely related, these results suggest a decrease in the excitability of the active motor cortex after an erroneous response. This modulation of the activity of the CST serves to prevent further premature and erroneous responses. At a more general level, the study shows the power of the TMS technique for the exploration of the temporal evolution of post-error adjustments within the motor system.

A long-term study of a patient with anti-p200 pemphigoid: correlation of autoantibody levels with disease activity and an example of epitope spreading

Anti-p200 pemphigoid is a rare subepidermal blistering disease associated with autoantibodies against a 200-kDa protein, reportedly corresponding to laminin γ1. However, direct evidence of the pathogenic potential of these antibodies has not been proven. For 5 years we have followed up a patient with anti-p200 pemphigoid. During this period she experienced a total of three generalized relapses. Quantifying our patient's autoantibody concentrations against laminin γ1 by enzyme-linked immunosorbent assay throughout the course of her disease we demonstrated a clear correlation with disease activity, thus providing the first evidence of the possible pathogenic role of antibodies against laminin γ1 in anti-p200 pemphigoid. Further analysis by Western blotting revealed the occurrence of additional autoantibodies against the α3 chain of laminin 332, 1·5 years after diagnosis, suggestive of intermolecular epitope spreading. Yet, the clinical appearance was unchanged and mucous membranes remained unaffected at any stage of the disease.

Force Measuring Methods for Determination of Surface Tension of Liquids: A Comparison

Three methods for the determination of the surface tension of liquids based on force measurements namely, the vertical plate method of Wilhelmy, the frame method of Lenard and the ring method of du Noüy are compared and studied in respect of a common principle of correction. It is shown that these three most important force-based methods allow the determination of the surface tension under static conditions. The force components of the corresponding liquid column below the measuring wire obtained for the straight part of the withdrawal curve up to the transition in its curved part provides exact surface tension values. The experimentally accessible value of the force component describes the physical background of the measured value correction contrary to the approximate equations obtained by mathematical way. Usually the determination of surface tension of liquids is based merely at the vertical plate method on exact equations thermodynamically derived whereas in the case of the frame and ring methods correction factors in approximate equations are used. At usual application of the force-based methods under the non-static condition of the withdrawal of a liquid column, the force maximum measured at withdrawal of the measuring object (plate, frame, or ring) is the basis for the determination of surface tension. In these cases, the measured surface tension values are compensated by correction equations for the frame and ring methods which are based on an correction factor and correction tables empirically obtained. The surface tension values obtained in this usual way agree with those obtained by using the force component of the corresponding liquid column below the measuring wire for the straight part of the withdrawal curve up to the transition in its curved part. Problems arising at the force measurements with increasing thickness of the measuring wires inside and outside the rings are discussed.

[IgA pemphigus of the subcorneal pustular dermatosis type. Successful therapy with a combination of dapsone and acitretin]

IgA pemphigus of the subcorneal pustular dermatosis type is a rare autoimmune blistering disease in the pemphigus spectrum. Patients are clinically characterized by extensive erythemas that primarily affect intertriginous areas. The erythematous macules are covered with numerous vesicles and pustules with occasional hypopyon formation. Histopathology shows subcorneal acantholysis with clefting and numerous neutrophils within the blister as well as in the edematous papillary dermis. IgA autoantibodies bind in vivo to keratinocytes within the upper half of the epidermis. Desmocollin 1, the autoantigen of this disease, is a member of desmosomal cadherins and is only expressed on more differentiated keratinocytes. The demonstration of circulating autoantibodies against desmocollin 1 in routine diagnosis is challenging and requires indirect immunofluorescence staining of desmocollin 1 transfected COS7 cells. We report a patient with a severe course of the disease who only responded to combined therapy with dapsone and acitretin.

[Quality of life, stress management and health promotion in medical and dental students. A comparative study]

OBJECTIVE

Which are the differences in health-related quality of life and stress management in medical and dental students?

METHODS

101 dental and 237 medical students from different years of Justus-Liebig University Giessen were examined during winter term 2008/09 and summer term 2009 using the specific Questionnaire on Health Promotion, Life Satisfaction, and Stress Management in Dental or Medical Students (addressing work satisfaction and choice of subject, private life, relaxation behavior and stress management, and health behavior), Beck Depression Inventory (BDI) and SF-36 Health Survey. For statistical analysis, Mann-Whitney-U-Test, analysis of variance (ANOVA), Pearson correlation and Chi2-Tests were primarily used.

RESULTS

Dental and medical students showed considerable mental impairment in SF-36. Every fifth dental student suffered from slight to moderate depression. Though averaging more hours per week, medical students were more satisfied with their studies. More than half of the dental and medical students did not have appropriate strategies of coping with stress.

CONCLUSIONS

Concerning the mental impairment in both groups and regarding a higher health-related quality of life, specific prevention courses or mentoring programs should already be offered at the beginning of medical training in order to cope with strains of medical school and future job strains in the medical or dental profession.

Invited article: Electric solar wind sail: toward test missions

The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.