Measuring, comparing and interpreting phenotypic selection on floral scent.

Natural selection on floral scent composition is a key element of the hypothesis that pollinators and other floral visitors drive scent evolution. The measure of such selection is complicated by the high-dimensional nature of floral scent data and uncertainty about the cognitive processes involved in scent-mediated communication. We use dimension reduction through reduced-rank regression to jointly estimate a scent composite trait under selection and the strength of selection acting on this trait. To assess and compare variation in selection on scent across species, time and space, we reanalyse 22 datasets on six species from four previous studies. The results agreed qualitatively with previous analyses in terms of identifying populations and scent compounds subject to stronger selection but also allowed us to evaluate and compare the strength of selection on scent across studies. Doing so revealed that selection on floral scent was highly variable, and overall about as common and as strong as selection on other phenotypic traits involved in pollinator attraction or pollen transfer. These results are consistent with an important role of floral scent in pollinator attraction. Our approach should be useful for further studies of plant-animal communication and for studies of selection on other high-dimensional phenotypes. In particular, our approach will be useful for studies of pollinator-mediated selection on complex scent blends comprising many volatiles, and when no prior information on the physiological responses of pollinators to scent compounds is available.

Cemented versus screw-retained posterior implant-supported single crowns: A 24-month randomized controlled clinical trial.

OBJECTIVES: To compare the incidence of biological and technical complications of cemented and screw-retained monolithic lithium-disilicate implant-supported posterior single crowns. MATERIAL AND METHODS: Forty-one subjects with a total of 56 implants received randomly allocated 28 cemented and 28 screw-retained crowns. In the screw-retained group, monolithic lithium-disilicate restorations were luted to titanium bases extraorally. In the cemented group, monolithic lithium-disilicate crowns were cemented on individualized titanium abutments intraorally. All restorations were examined according to modified FDI criteria within 2 weeks of inserting the crowns (baseline) and after 12 (n = 46) and 24 (n = 43) months. Bone loss was evaluated by standardized radiographs at baseline and 12 months. RESULTS: After 12 months, the incidence of mucositis (positive bleeding on probing) was 14.2% (screw-retained) and 17.9% (cement-retained). The gingival and plaque index and a mean marginal bone loss between 0.03-0.15 mm showed no significant difference between the groups. In the cemented group, cement residues were detected at baseline at two restorations (6.9%) by radiographic examination. A complete digital workflow was realized in most cases (85.7%). At 24 months, no restoration had failed, and no chipping of the ceramic had occurred. In the screw-retained group, screw loosening occurred in one implant. In both groups, there was obvious deterioration in the quality of 32% of the occlusal and of 18% of the proximal contact points. CONCLUSIONS: The type of retention mode of monolithic implant-retained lithium-disilicate posterior crowns had no influence on the biological and technical complication rate.

Introduction to a Landscape Analysis of Multisectoral Approaches for Prevention and Control of Infectious and Vector-Borne Diseases.

The Swiss Development Cooperation, Canada's International Development Research Centre, the Swiss Tropical Public Health Institute, and the UNICEF/United Nations Development Programme (UNDP)/World Bank/World Health Organization (WHO) Special Programme for Research and Training in Tropical Diseases (TDR) collaborated on a project to review, understand and promote the use of multisectoral approaches (MSAs) in the prevention and control of vector-borne diseases (VBDs). The objectives of the project were to support a landscape analysis of how MSAs have been used in the prevention and control of VBDs; to develop a theoretical framework for guiding the implementation of interventions; and to test the recommendations in real-life conditions. To realize these objectives, the project supported several activities, including commissioning a series of scientific reviews on MSAs in 5 thematic areas, sharing the key findings of these reviews in workshops and events, and developing a guidance framework for the implementation of MSAs. These activities have produced the theoretical framework that will be tested in real-life conditions through the support of case studies. The collaboration on implementing multisectoral activities against VBDs will continue among TDR, the Swiss Tropical Public Health Institute, and new partners such as the WHO Water Sanitation and Hygiene Group, UNDP, and UN-Habitat, in order to face the challenges identified and propose solutions tailored to specific contexts. The prevention and control of VBDs require strong and adapted MSAs with the full participation of all relevant sectors.

Structure-function analysis of heterodimer formation, oligomerization, and receptor binding of the Staphylococcus aureus bi-component toxin LukGH.

The bi-component leukocidins of Staphylococcus aureus are important virulence factors that lyse human phagocytic cells and contribute to immune evasion. The γ-hemolysins (HlgAB and HlgCB) and Panton-Valentine leukocidin (PVL or LukSF) were shown to assemble from soluble subunits into membrane-bound oligomers on the surface of target cells, creating barrel-like pore structures that lead to cell lysis. LukGH is the most distantly related member of this toxin family, sharing only 30-40% amino acid sequence identity with the others. We observed that, unlike other leukocidin subunits, recombinant LukH and LukG had low solubility and were unable to bind to target cells, unless both components were present. Using biolayer interferometry and intrinsic tryptophan fluorescence we detected binding of LukH to LukG in solution with an affinity in the low nanomolar range and dynamic light scattering measurements confirmed formation of a heterodimer. We elucidated the structure of LukGH by x-ray crystallography at 2.8-Šresolution. This revealed an octameric structure that strongly resembles that reported for HlgAB, but with important structural differences. Structure guided mutagenesis studies demonstrated that three salt bridges, not found in other bi-component leukocidins, are essential for dimer formation in solution and receptor binding. We detected weak binding of LukH, but not LukG, to the cellular receptor CD11b by biolayer interferometry, suggesting that in common with other members of this toxin family, the S-component has the primary contact role with the receptor. These new insights provide the basis for novel strategies to counteract this powerful toxin and Staphylococcus aureus pathogenesis.

Are tetraploids more successful? Floral signals, reproductive success and floral isolation in mixed-ploidy populations of a terrestrial orchid.

BACKGROUND AND AIMS: Polyploidization, the doubling of chromosome sets, is common in angiosperms and has a range of evolutionary consequences. Newly formed polyploid lineages are reproductively isolated from their diploid progenitors due to triploid sterility, but also prone to extinction because compatible mating partners are rare. Models have suggested that assortative mating and increased reproductive fitness play a key role in the successful establishment and persistence of polyploids. However, little is known about these factors in natural mixed-ploidy populations. This study investigated floral traits that can affect pollinator attraction and efficiency, as well as reproductive success in diploid and tetraploid Gymnadenia conopsea (Orchidaceae) plants in two natural, mixed-ploidy populations. METHODS: Ploidy levels were determined using flow cytometry, and flowering phenology and herbivory were also assessed. Reproductive success was determined by counting fruits and viable seeds of marked plants. Pollinator-mediated floral isolation was measured using experimental arrays, with pollen flow tracked by means of staining pollinia with histological dye. KEY RESULTS: Tetraploids had larger floral displays and different floral scent bouquets than diploids, but cytotypes differed only slightly in floral colour. Significant floral isolation was found between the two cytotypes. Flowering phenology of the two cytotypes greatly overlapped, and herbivory did not differ between cytotypes or was lower in tetraploids. In addition, tetraploids had higher reproductive success compared with diploids. CONCLUSIONS: The results suggest that floral isolation and increased reproductive success of polyploids may help to explain their successful persistence in mixed-ploidy populations. These factors might even initiate transformation of populations from pure diploid to pure tetraploid.

'I know it has worked for millions of years': the role of the 'natural' in parental reasoning against child immunization in a qualitative study in Switzerland.

BACKGROUND: Despite efforts of international and national health authorities, immunization coverage and timeliness of vaccination against dangerous childhood diseases have been adversely affected by parental hesitation to vaccinate their children in high-income countries. Literature shows that social and political processes and shifts in conceptual structures, such as emerging views linked to health and 'natural' lifestyles, have shaped parents' immunization decisions. This paper investigates how Swiss parents argued along the lines of a natural development of the child to explain their critical attitudes towards immunization against measles and other childhood diseases. METHODS: A total of 32 semi-structured interviews were conducted with parents of children between 0 and 16 years of age who decided not to fully immunize their children. The interviews were analyzed using qualitative content analysis and an interpretative approach. RESULTS: Parents built their arguments against immunization on a strong faith in the strength of the naturally acquired immune system. Childhood diseases were not perceived as a threat but as part of the natural way to reinforce the body and to acquire a "natural" and thus strong immunity. Parents understood immunization as an artificial intrusion into the natural development of the immune system and feared overloading the still immature immune system of their young children and infants through current vaccination schemes. CONCLUSIONS: In the context of emerging trends towards natural lifestyles and ideas of holistic health in Switzerland and Europe, where many well-informed parents express concerns towards vaccinating their children, public vaccination strategies require reconsideration. Public immunization schedules need to acknowledge parents' wish for more flexibility and demand for an individualized patient-centered approach to immunization.

Floral adaptation to local pollinator guilds in a terrestrial orchid.

BACKGROUND AND AIMS: Studies of local floral adaptation in response to geographically divergent pollinators are essential for understanding floral evolution. This study investigated local pollinator adaptation and variation in floral traits in the rewarding orchid Gymnadenia odoratissima, which spans a large altitudinal gradient and thus may depend on different pollinator guilds along this gradient. METHODS: Pollinator communities were assessed and reciprocal transfer experiments were performed between lowland and mountain populations. Differences in floral traits were characterized by measuring floral morphology traits, scent composition, colour and nectar sugar content in lowland and mountain populations. KEY RESULTS: The composition of pollinator communities differed considerably between lowland and mountain populations; flies were only found as pollinators in mountain populations. The reciprocal transfer experiments showed that when lowland plants were transferred to mountain habitats, their reproductive success did not change significantly. However, when mountain plants were moved to the lowlands, their reproductive success decreased significantly. Transfers between populations of the same altitude did not lead to significant changes in reproductive success, disproving the potential for population-specific adaptations. Flower size of lowland plants was greater than for mountain flowers. Lowland plants also had significantly higher relative amounts of aromatic floral volatiles, while the mountain plants had higher relative amounts of other floral volatiles. The floral colour of mountain flowers was significantly lighter compared with the lowland flowers. CONCLUSIONS: Local pollinator adaptation through pollinator attraction was shown in the mountain populations, possibly due to adaptation to pollinating flies. The mountain plants were also observed to receive pollination from a greater diversity of pollinators than the lowland plants. The different floral phenotypes of the altitudinal regions are likely to be the consequence of adaptations to local pollinator guilds.

Targeted proteolysis of plectin isoform 1a accounts for hemidesmosome dysfunction in mice mimicking the dominant skin blistering disease EBS-Ogna.

Autosomal recessive mutations in the cytolinker protein plectin account for the multisystem disorders epidermolysis bullosa simplex (EBS) associated with muscular dystrophy (EBS-MD), pyloric atresia (EBS-PA), and congenital myasthenia (EBS-CMS). In contrast, a dominant missense mutation leads to the disease EBS-Ogna, manifesting exclusively as skin fragility. We have exploited this trait to study the molecular basis of hemidesmosome failure in EBS-Ogna and to reveal the contribution of plectin to hemidesmosome homeostasis. We generated EBS-Ogna knock-in mice mimicking the human phenotype and show that blistering reflects insufficient protein levels of the hemidesmosome-associated plectin isoform 1a. We found that plectin 1a, in contrast to plectin 1c, the major isoform expressed in epidermal keratinocytes, is proteolytically degraded, supporting the notion that degradation of hemidesmosome-anchored plectin is spatially controlled. Using recombinant proteins, we show that the mutation renders plectin's 190-nm-long coiled-coil rod domain more vulnerable to cleavage by calpains and other proteases activated in the epidermis but not in skeletal muscle. Accordingly, treatment of cultured EBS-Ogna keratinocytes as well as of EBS-Ogna mouse skin with calpain inhibitors resulted in increased plectin 1a protein expression levels. Moreover, we report that plectin's rod domain forms dimeric structures that can further associate laterally into remarkably stable (paracrystalline) polymers. We propose focal self-association of plectin molecules as a novel mechanism contributing to hemidesmosome homeostasis and stabilization.

Applying the photovoice method with adolescents in mining areas in rural Mozambique: critical reflections and lessons learned.

There is a recognised need for innovative methods to elicit the perspective of adolescents on public health issues, particularly when addressing sensitive topics such as the impact of mining projects on their health. Participatory approaches such as "photovoice" allow for deep engagement of vulnerable and marginalised populations, including adolescents. However, few existing studies have used the photovoice method to reflect on issues related to the environment and its impact on public health. To date, no studies have been found that have used photovoice to gain insight into adolescents' perspectives in mining areas. In this paper, we discuss the application of the photovoice method to understand adolescents' perceptions about the impact of mining on their health and well-being in rural areas in Mozambique. The study was conducted in northern and central Mozambique. Photovoice was successfully integrated into eight focus group discussions with adolescent girls and boys aged 15 to 17 years. Several lessons for guiding future research were learned. First, it provided an understanding of the perceived impacts of mining on their health and well-being. Second, photovoice promoted active engagement and interest in the study by the adolescents. Finally, compared to its ability to capture perceptions of physical and environmental aspects affecting adolescents' well-being, the method was less straightforward in revealing their concerns regarding social, relational and community aspects that are less tangible. Programs can make use of photovoice to address health issues without setting adolescents' views and priorities aside, allowing them to influence health decisions on issues that are meaningful to them. Future studies should explore strategies to minimise the role of the power dynamics that affect the engagement and contribution of adolescents in advocating for necessary and meaningful changes. Additionally, it is important to investigate how health programs and policies can help to reduce the impact of existing inequalities.

Assessing the Effectiveness of a Multicomponent Intervention on Hand Hygiene and Well-Being in Primary Health Care Centers and Schools Lacking Functional Water Supply in Protracted Conflict Settings: Protocol for a Cluster Randomized Controlled Trial.

BACKGROUND: Hand hygiene is crucial in health care centers and schools to avoid disease transmission. Currently, little is known about hand hygiene in such facilities in protracted conflict settings. OBJECTIVE: This protocol aims to assess the effectiveness of a multicomponent hand hygiene intervention on handwashing behavior, underlying behavioral factors, and the well-being of health care workers and students. Moreover, we report our methodology and statistical analysis plan transparently. METHODS: This is a cluster randomized controlled trial with 2 parallel arms taking place in 4 countries for 1 year. In Burkina Faso and Mali, we worked in 24 primary health care centers per country, whereas in Nigeria and Palestine, we focused on 26 primary schools per country. Facilities were eligible if they were not connected to a functioning water source but were deemed accessible to the implementation partners. Moreover, health care centers were eligible if they had a maternity ward and ≥5 employees, and schools if they had ≤7000 students studying in grades 5 to 7. We used covariate-constrained randomization to assign intervention facilities that received a hardware, management and monitoring support, and behavior change. Control facilities will receive the same or improved intervention after endline data collection. To evaluate the intervention, at baseline and endline, we used a self-reported survey, structured handwashing observations, and hand-rinse samples. At follow-up, hand-rinse samples were dropped. Starting from the intervention implementation, we collected longitudinal data on hygiene-related health conditions and absenteeism. We also collected qualitative data with focus group discussions and interviews. Data were analyzed descriptively and with random effect regression models with the random effect at a cluster level. The primary outcome for health centers is the handwashing rate, defined as the number of times health care workers performed good handwashing practice with soap or alcohol-based handrub at one of the World Health Organization 5 moments for hand hygiene, divided by the number of moments for hand hygiene that presented themselves during the patient interaction within an hour of observation. For schools, the primary outcome is the number of students who washed their hands before eating. RESULTS: The baseline data collection across all countries lasted from February to June 2023. We collected data from 135 and 174 health care workers in Burkina Faso and Mali, respectively. In Nigeria, we collected data from 1300 students and in Palestine from 1127 students. The endline data collection began in February 2024. CONCLUSIONS: This is one of the first studies investigating hand hygiene in primary health care centers and schools in protracted conflict settings. With our strong study design, we expect to support local policy makers and humanitarian organizations in developing sustainable agendas for hygiene promotion. TRIAL REGISTRATION: ClinicalTrials.gov NCT05946980 (Burkina Faso and Mali); https://www.clinicaltrials.gov/study/NCT05946980 and NCT05964478 (Nigeria and Palestine); https://www.clinicaltrials.gov/study/NCT05964478. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/52959.

'My wife, you are supposed to have a rest now': an analysis of norms influencing men's role in prenatal care in south-eastern Tanzania.

Men as sexual partners, fathers and household heads have a direct bearing on women's reproductive health. However, little is known about the influence of changing norms and values on men's role in ensuring women's health during pregnancy and childbirth. This study from rural south-eastern Tanzania explores men's and women's discussions on men's roles and responsibilities in prenatal care and links them to an analysis of norms and values at the household level and beyond. Data from eight focus group discussions with men and women were consensually coded and analysed using a qualitative content analysis. Four dimensions of norms and values, which emerged from analysis, bear upon men's support towards pregnant women: changing gender identities; changing family and marriage structures; biomedical values disseminated in health education; and government regulations. The findings suggest that Tanzanian men are exposed to a contradictory and changing landscape of norms and values in relation to maternal health.

Digest: Recreating ancestral trait variation to understand adaptation.

Two highly correlated anther traits affect pollination efficacy in a wild radish population. Does the strength and type of selection on these traits differ through male and female fitness with increased ancestral trait variation? Waterman et al. (2023) found stabilizing selection on one trait and disruptive selection on the other trait, with no difference between male and female fitness. Such quantifications of selection in populations with the increased variation that reflects ancestral trait variation provide insights into processes of trait adaptation.

Components of local adaptation and divergence in pollination efficacy in a coevolving species interaction.

Selection leading to adaptation to interactions may generate rapid evolutionary feedbacks and drive diversification of species interactions. The challenge is to understand how the many traits of interacting species combine to shape local adaptation in ways directly or indirectly resulting in diversification. We used the well-studied interactions between Lithophragma plants (Saxifragaceae) and Greya moths (Prodoxidae) to evaluate how plants and moths together contributed to local divergence in pollination efficacy. Specifically, we studied L. bolanderi and its two specialized Greya moth pollinators in two contrasting environments in the Sierra Nevada in California. Both moths pollinate L. bolanderi during nectaring, one of them-G. politella-also while ovipositing through the floral corolla into the ovary. First, field surveys of floral visitors and the presence of G. politella eggs and larvae in developing capsules showed that one population was visited only by G. politella and few other pollinators, whereas the other was visited by both Greya species and other pollinators. Second, L. bolanderi in these two natural populations differed in several floral traits putatively important for pollination efficacy. Third, laboratory experiments with greenhouse-grown plants and field-collected moths showed that L. bolanderi was more efficiently pollinated by local compared to nonlocal nectaring moths of both species. Pollination efficacy of ovipositing G. politella was also higher for local moths for the L. bolanderi population, which relies more heavily on this species in nature. Finally, time-lapse photography in the laboratory showed that G. politella from different populations differed in oviposition behavior, suggesting the potential for local adaptation also among Greya populations. Collectively, our results are a rare example of components of local adaptation contributing to divergence in pollination efficacy in a coevolving interaction and, thus, provide insights into how geographic mosaics of coevolution may lead to coevolutionary diversification in species interactions.

Timing of antenatal care for adolescent and adult pregnant women in south-eastern Tanzania.

BACKGROUND: Early and frequent antenatal care attendance during pregnancy is important to identify and mitigate risk factors in pregnancy and to encourage women to have a skilled attendant at childbirth. However, many pregnant women in sub-Saharan Africa start antenatal care attendance late, particularly adolescent pregnant women. Therefore they do not fully benefit from its preventive and curative services. This study assesses the timing of adult and adolescent pregnant women's first antenatal care visit and identifies factors influencing early and late attendance. METHODS: The study was conducted in the Ulanga and Kilombero rural Demographic Surveillance area in south-eastern Tanzania in 2008. Qualitative exploratory studies informed the design of a structured questionnaire. A total of 440 women who attended antenatal care participated in exit interviews. Socio-demographic, social, perception- and service related factors were analysed for associations with timing of antenatal care initiation using regression analysis. RESULTS: The majority of pregnant women initiated antenatal care attendance with an average of 5 gestational months. Belonging to the Sukuma ethnic group compared to other ethnic groups such as the Pogoro, Mhehe, Mgindo and others, perceived poor quality of care, late recognition of pregnancy and not being supported by the husband or partner were identified as factors associated with a later antenatal care enrolment (p < 0.05). Primiparity and previous experience of a miscarriage or stillbirth were associated with an earlier antenatal care attendance (p < 0.05). Adolescent pregnant women started antenatal care no later than adult pregnant women despite being more likely to be single. CONCLUSIONS: Factors including poor quality of care, lack of awareness about the health benefit of antenatal care, late recognition of pregnancy, and social and economic factors may influence timing of antenatal care. Community-based interventions are needed that involve men, and need to be combined with interventions that target improving the quality, content and outreach of antenatal care services to enhance early antenatal care enrolment among pregnant women.

"Workhood"-a useful concept for the analysis of health workers' resources? An evaluation from Tanzania.

BACKGROUND: International debates on improving health system performance and quality of care are strongly coined by systems thinking. There is a surprising lack of attention to the human (worker) elements. Although the central role of health workers within the health system has increasingly been acknowledged, there are hardly studies that analyze performance and quality of care from an individual perspective. Drawing on livelihood studies in health and sociological theory of capitals, this study develops and evaluates the new concept of workhood. As an analytical device the concept aims at understanding health workers' capacities to access resources (human, financial, physical, social, cultural and symbolic capital) and transfer them to the community from an individual perspective. METHODS: Case studies were conducted in four Reproductive-and-Child-Health (RCH) clinics in the Kilombero Valley, south-eastern Tanzania, using different qualitative methods such as participant observation, informal discussions and in-depth interviews to explore the relevance of the different types of workhood resources for effective health service delivery. Health workers' ability to access these resources were investigated and factors facilitating or constraining access identified. RESULTS: The study showed that lack of physical, human, cultural and financial capital constrained health workers' capacity to act. In particular, weak health infrastructure and health system failures led to the lack of sufficient drug and supply stocks and chronic staff shortages at the health facilities. However, health workers' capacity to mobilize social, cultural and symbolic capital played a significant role in their ability to overcome work related problems. Professional and non-professional social relationships were activated in order to access drug stocks and other supplies, transport and knowledge. CONCLUSIONS: By evaluating the workhood concept this study highlights the importance of understanding health worker performance by looking at their resources and capacities. Rather than blaming health workers for health system failures, applying a strength-based approach offers new insights into health workers' capacities and identifies entry points for target actions.

The combined effect of determinants on coverage of intermittent preventive treatment of malaria during pregnancy in the Kilombero Valley, Tanzania.

BACKGROUND: Intermittent preventive treatment during pregnancy (IPTp) at routine antenatal care (ANC) clinics is an important and efficacious intervention to reduce adverse health outcomes of malaria infections during pregnancy. However, coverage for the recommended two IPTp doses is still far below the 80% target in Tanzania. This paper investigates the combined impact of pregnant women's timing of ANC attendance, health workers' IPTp delivery and different delivery schedules of national IPTp guidelines on IPTp coverage. METHODS: Data on pregnant women's ANC attendance and health workers' IPTp delivery were collected from ANC card records during structured exit interviews with ANC attendees and through semi-structured interviews with health workers in south-eastern Tanzania. Women's timing of ANC visits and health worker's timing of IPTp delivery were analyzed in relation to the different national IPTp schedules and the outcome on IPTp coverage was modelled. RESULTS: Among all women eligible for IPTp, 79% received a first dose of IPTp and 27% were given a second dose. Although pregnant women initiated ANC attendance late, their timing was in line with the national guidelines recommending IPTp delivery between 20-24 weeks and 28-32 weeks of gestation. Only 15% of the women delayed to the extent of being too late to be eligible for a first dose of IPTp. Less than 1% of women started ANC attendance after 32 weeks of gestation. During the second IPTp delivery period health workers delivered IPTp to significantly less women than during the first one (55% vs. 73%) contributing to low second dose coverage. Simplified IPTp guidelines for front-line health workers as recommended by WHO could lead to a 20 percentage point increase in IPTp coverage. CONCLUSIONS: This study suggests that facility and policy factors are greater barriers to IPTp coverage than women's timing of ANC attendance. To maximize the benefit of the IPTp intervention, revision of existing guidelines is needed. Training on simplified IPTp messages should be consolidated as part of the extended antenatal care training to change health workers' delivery practices and increase IPTp coverage. Pregnant women's knowledge about IPTp and the risks of malaria during pregnancy should be enhanced as well as their ability and power to demand IPTp and other ANC services.

Antenatal care in practice: an exploratory study in antenatal care clinics in the Kilombero Valley, south-eastern Tanzania.

BACKGROUND: The potential of antenatal care for reducing maternal morbidity and improving newborn survival and health is widely acknowledged. Yet there are worrying gaps in knowledge of the quality of antenatal care provided in Tanzania. In particular, determinants of health workers' performance have not yet been fully understood. This paper uses ethnographic methods to document health workers' antenatal care practices with reference to the national Focused Antenatal Care guidelines and identifies factors influencing health workers' performance. Potential implications for improving antenatal care provision in Tanzania are discussed. METHODS: Combining different qualitative techniques, we studied health workers' antenatal care practices in four public antenatal care clinics in the Kilombero Valley, south-eastern Tanzania. A total of 36 antenatal care consultations were observed and compared with the Focused Antenatal Care guidelines. Participant observation, informal discussions and in-depth interviews with the staff helped to identify and explain health workers' practices and contextual factors influencing antenatal care provision. RESULTS: The delivery of antenatal care services to pregnant women at the selected antenatal care clinics varied widely. Some services that are recommended by the Focused Antenatal Care guidelines were given to all women while other services were not delivered at all. Factors influencing health workers' practices were poor implementation of the Focused Antenatal Care guidelines, lack of trained staff and absenteeism, supply shortages and use of working tools that are not consistent with the Focused Antenatal Care guidelines. Health workers react to difficult working conditions by developing informal practices as coping strategies or "street-level bureaucracy". CONCLUSIONS: Efforts to improve antenatal care should address shortages of trained staff through expanding training opportunities, including health worker cadres with little pre-service training. Attention should be paid to the identification of informal practices resulting from individual coping strategies and "street-level bureaucracy" in order to tackle problems before they become part of the organizational culture.

Behavioral plasticity allows short-term adjustment to a novel environment.

Many species are currently experiencing anthropogenically driven environmental changes. Among these changes, increasing noise levels are specifically a problem for species relying on acoustic communication. Recent evidence suggests that some species adjust their acoustic signals to man-made noise. However, it is unknown whether these changes occur through short-term and reversible adjustments by behavioral plasticity or through long-term adaptations by evolutionary change. Using behavioral observations and playback experiments, we show that male reed buntings (Emberiza schoeniclus) adjusted their songs immediately, singing at a higher minimum frequency and at a lower rate when noise levels were high. Our data showed that these changes in singing behavior were short-term adjustments of signal characteristics resulting from behavioral plasticity, rather than a long-term adaptation. However, more males remained unpaired at a noisy location than at a quiet location throughout the breeding season. Thus, phenotypic plasticity enables individuals to respond to environmental changes, but whether these short-term adjustments are beneficial remains to be seen.

Alfred Gysi (1865-1957) - More than a Pioneer of Dental Prosthetics and Articulation.

Alfred Gysi was one of the most influential dental scientists of the last century. He is primarily considered a pioneer of modern articulation and occlusion theory, and several of his technical developments still bear his name. But what milieu did this dentist come from, what characterized his academic career and what research contributions did he make beyond the theory of articulation? How was he perceived by contemporary experts ­ as a researcher and as a colleague ­ and how can his scientific contributions be classified from today's perspective? These are precisely the questions that this article examines. The study is based on contemporary primary sources and on Gysi's own publications. In addition, a systematic re-analysis of the available secondary literature on the life and work of Alfred Gysi and on the history of the Zurich Dental Institute was carried out. The analysis shows that Gysi had a strong influence on contemporary dental prosthodontics and contributed considerably to its scientific character, especially due to the development of articulators and face bows, which received worldwide attention. But Gysi's scientific influence was by no means limited to prosthetics. Rather, he also provided important studies on caries and the dental pulp. Moreover, he published fundamental work on dental histopathology and microphotography. The current image of Gysi therefore needs to be revised. In view of the thematic breadth of his scientific contributions, Gysi is not only the most important prosthodontist of his time, but also one of the most versatile and innovative representatives in the history of Swiss dentistry.

Digitalization in dentistry: ethical challenges and implications.

OBJECTIVE: Scientific papers and books on digital dentistry are in vogue. In most cases, these publications focus clearly on the - undoubted - potentials and possibilities offered by digitalization. The fact that digital dentistry necessarily entails risks and ethical challenges, by contrast, is rarely discussed. This paper aims to complement the discourse on digitalization in dentistry by analyzing precisely these challenges. METHOD AND MATERIALS: The study is based on an analysis of international publications and specialist writings on digitalization and its applications in the fields of dentistry and medicine, as well as on the analysis of specific contributions from the disciplines of medical ethics and medical law, and from the public media. RESULTS: The paper identifies and discusses eight core challenges: (1) big data ("digital double" and falsification in dentistry), (2) the dental practitioner-patient relationship, (3) digital literacy, (4) the assumption of responsibility in complex systems, (5) accompanying changes in the dental professions, (6) cost trap and risks of overtreatment in dentistry, (7) consumption spiral and ecologic footprint, and (8) clinical evidence in dental treatments. In addition, a catalog of criteria for assessing the effects of digitalization in dentistry is developed. CONCLUSION: It is crucial to closely monitor both the potentials and the challenges posed by digitalization in dentistry. Ultimately, it is only those problems that are identified as such that can be resolved and only those technologies that are accepted by dentists, patients, and society that will prevail in the long term.