Decoding the Evolution of Melanin in Vertebrates.

Melanins are widespread pigments in vertebrates, with important roles in visual signaling, UV protection, and homeostasis. Fossil evidence of melanin and melanin-bearing organelles - melanosomes - in ancient vertebrates may illuminate the evolution of melanin and its functions, but macroevolutionary trends are poorly resolved. Here, we integrate fossil data with current understanding of melanin function, biochemistry, and genetics. Mapping key genes onto phenotypic attributes of fossil vertebrates identifies potential genomic controls on melanin evolution. Taxonomic trends in the anatomical location, geometry, and chemistry of vertebrate melanosomes are linked to the evolution of endothermy. These shifts in melanin biology suggest fundamental links between melanization and vertebrate ecology. Tissue-specific and taxonomic trends in melanin chemistry support evidence for evolutionary tradeoffs between function and cytotoxicity.

Expert Elicitation Provides a Rapid Alternative to Formal Case-Control Study of an H7N9 Avian Influenza Outbreak in the United States.

An expert elicitation was staged to rapidly decipher plausible routes and risks of pathogen transmission in the 2017 H7N9 avian influenza (AI) outbreak in the four-state region of Tennessee, Alabama, Georgia, and Kentucky. The process included the identification of risk factors found in a preponderance of commercial broiler breeder case farms over matched controls and an opinion-based weighting of risks and mitigations perceived influential to this outbreak. Although the two highly pathogenic AI case farms had general location and company ownership in common, obvious connections were lacking for the remainder of H7N9-infected (all low pathogenicity) commercial farms. Expert elicitation of differences between known cases and controls suggested a key role for environmental rather than lateral (business network) pathways in the distribution of low pathogenicity AI across commercial broiler breeder operations. Factors with greatest strength as predictors of disease, whether or not they were causal, included mesopredator or rodent incursions, enclosure defects, and habitat disturbance that might attract wildlife to the farm (e.g., feed spills and vacating of neighboring properties). Business affiliations that may have facilitated farm-to-farm transfer, in contrast, were limited. Biosecurity standards varied across this study group but were no more or less stringent among cases over controls. However, results from a parallel hypothetical scenario staged to address field data gaps suggest that uniformity and consistency in the implementation of biosecurity practices may impact risk of disease introduction. Importantly, this study was conducted within a few weeks and with little disruption to emergency response activities. As such, the approach offers an alternative model for interim field investigation of new or emerging high-consequence diseases with immediate decision support needs.

Multiscale correlative tomography: an investigation of creep cavitation in 316 stainless steel.

Creep cavitation in an ex-service nuclear steam header Type 316 stainless steel sample is investigated through a multiscale tomography workflow spanning eight orders of magnitude, combining X-ray computed tomography (CT), plasma focused ion beam (FIB) scanning electron microscope (SEM) imaging and scanning transmission electron microscope (STEM) tomography. Guided by microscale X-ray CT, nanoscale X-ray CT is used to investigate the size and morphology of cavities at a triple point of grain boundaries. In order to understand the factors affecting the extent of cavitation, the orientation and crystallographic misorientation of each boundary is characterised using electron backscatter diffraction (EBSD). Additionally, in order to better understand boundary phase growth, the chemistry of a single boundary and its associated secondary phase precipitates is probed through STEM energy dispersive X-ray (EDX) tomography. The difference in cavitation of the three grain boundaries investigated suggests that the orientation of grain boundaries with respect to the direction of principal stress is important in the promotion of cavity formation.

Practitioners' experiences of adolescent suicidal behaviour in peer groups.

WHAT IS KNOWN ON THE SUBJECT?: Group suicidal behaviour can be devastating for all concerned. There is an absence of research on adolescent suicidal group behaviour. The perspectives of practitioners' experiences of these groups are largely lacking from research literature. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: Practitioners work regularly with suicidal behaviour in adolescent peer groups. Practitioners identify peer relationships in groups as complex, including elements that are both suicide encouraging and preventing. Practitioners identify a range of ways in which young people become involved in suicidal behaviour in groups, including indirectly through risk taking and care-seeking as well as directly suicidal or self-harming. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Assessments of young people should routinely include a focus on the qualities of peer relations, including those in the online/digital realm. Assessments and interventions need to consider the complexity of group relationships and roles, and the multiplicity of factors that can contribute to suicidal behaviour in groups. Interventions that sustain therapeutic connectedness are helpful for taking dynamic/fluctuating risks into account. ABSTRACT: Introduction Group suicidal behaviour by young people can have harmful effects; it may be increasing, influenced by online media and reported increasing self-harm rates; new knowledge and understanding to inform interventions is required. Aim To explore how practitioners experience group suicidal behaviour amongst adolescents, how they assess risks/needs, and how these insights inform understanding about these groups. Method Ten practitioners, including Mental Health Nurses, were interviewed in one multidisciplinary CAMHS, in England. Data analysis was by Thematic Analysis (Braun & Clarke 2006). Results Participants described frequently working with suicidal groups. Roles in groups include suicide encouraging and preventing. Practitioners identify risky and protective connections between young people, online and offline. Clinical tensions include living with suicidal risks, emotional and positional challenges, and getting to grips with digital media. Discussion Peer groups appear to have a larger role in adolescent suicide than recognized to date. Practitioners need to assess young people's roles in groups, their diverse motivations and to understand constantly changing digital media. Implications for practice Assessments of suicide risk for young people should routinely include focus on peer relations including the online/digital realm. Maintaining relationships with vulnerable young people facilitates managing fluctuating risks and understanding different group dynamics.

Real-time imaging and elemental mapping of AgAu nanoparticle transformations.

We report the controlled alloying, oxidation, and subsequent reduction of individual AgAu nanoparticles in the scanning transmission electron microscope (STEM). Through sequential application of electron beam induced oxidation and in situ heating and quenching, we demonstrate the transformation of Ag-Au core-shell nanoparticles into: AgAu alloyed, Au-Ag core-shell, hollow Au-Ag2O core-shell, and Au-Ag2O yolk-shell nanoparticles. We are able to directly image these morphological transformations in real-time at atomic resolution and perform energy dispersive X-ray (EDX) spectrum imaging to map changing elemental distributions with sub-nanometre resolution. By combining aberration corrected STEM imaging and high efficiency EDX spectroscopy we are able to quantify not only the growth and coalescence of Kirkendall voids during oxidation but also the compositional changes occurring during this reaction. This is the first time that it has been possible to track the changing distribution of elements in an individual nanoparticle undergoing oxidation driven shell growth and hollowing.

Measurement of size-dependent composition variations for gamma prime (γ') precipitates in an advanced nickel-based superalloy.

Energy-dispersive X-ray (EDX) spectroscopy in the scanning transmission electron microscope (STEM) has been used to demonstrate the presence of size-dependent compositional variation for L12-structured Ni3Al-type gamma-prime (γ') precipitates within a commercial RR1000 Ni-based superalloy. This semi-quantitative elemental analysis has been achieved using electrochemical extraction of the γ' precipitates from the γ matrix. The applicability of this approach to size-dependent compositional analysis of precipitates was confirmed by a comparison of the size distribution for the extracted precipitates with those present in traditional electropolished foil specimens in the size range 20-250nm. By applying suitable thickness-dependent absorption-corrections we have demonstrated that the composition of γ' precipitates in our material depends on the size of the precipitate in the range of 5nm to 3µm. In particular, the Al content was observed to increase in smaller γ' precipitates while Ti and Ta contents are constant for all sizes of precipitate. Hf was observed to be present only in the largest precipitates. This type of local compositional information provides invaluable input to assess the accuracy of microstructural modelling for these complex alloys and provides new evidence supporting the importance of anti-site diffusion.

Correlative tomography.

Increasingly researchers are looking to bring together perspectives across multiple scales, or to combine insights from different techniques, for the same region of interest. To this end, correlative microscopy has already yielded substantial new insights in two dimensions (2D). Here we develop correlative tomography where the correlative task is somewhat more challenging because the volume of interest is typically hidden beneath the sample surface. We have threaded together x-ray computed tomography, serial section FIB-SEM tomography, electron backscatter diffraction and finally TEM elemental analysis all for the same 3D region. This has allowed observation of the competition between pitting corrosion and intergranular corrosion at multiple scales revealing the structural hierarchy, crystallography and chemistry of veiled corrosion pits in stainless steel. With automated correlative workflows and co-visualization of the multi-scale or multi-modal datasets the technique promises to provide insights across biological, geological and materials science that are impossible using either individual or multiple uncorrelated techniques.

Pine dust, atopy and lung function: A cross-sectional study in sawmill workers.

An increased risk of asthma symptoms has previously been shown in 772 pine sawmill workers. The aim of the current study was to assess the association between dust exposure, lung function and atopy. Subjects with (n = 59) and without (n = 167) asthma symptoms were randomly selected from the previous survey. Lung function and atopy were determined using spirometry and skin-prick tests, respectively. Inhalable dust levels were measured on the same day. The geometric mean dust concentration was 0.52 mg x m(-3). Exposure to dry but not to green dust was associated with asthma symptoms. Green dust was associated with atopic sensitisation, particularly against outdoor allergens; no association was found for dry dust. Forced vital capacity, forced expiratory volume in one second and peak expiratory flow were significantly lower in workers exposed to high levels of green dust (-350 mL, -260 mL and -860 mL x s(-1), respectively) and dry dust (-230 mL, -190 mL and -850 mL x s(-1), respectively). These associations were observed both in subjects with and without asthma symptoms. No associations with cross-shift changes in lung function were found. Exposure to green pine sawdust may be a risk factor for atopy. Both green and dry dust were associated with obstructive as well as restrictive pulmonary effects.

Asthma and other respiratory symptoms in New Zealand pine processing sawmill workers.

BACKGROUND: To study respiratory symptoms in pine sawmill workers. METHODS: A respiratory health questionnaire was administered to 772 pine sawmill workers and the association between symptoms and job-title-based exposure was studied. RESULTS: Asthma in exposed workers (18%, n = 704) was more common than in the general population (12.1%, n = 592; adjusted OR (95% CI): 1.6 (1.1-2.3)). Asthma was also more common in the low exposure group (15.6%, n = 294) and high exposure groups (high exposure to 'green dust'; 20.4%, n = 212 and high exposure to 'dry dust'; 18.8%, n = 198) than in the non-exposed workers (9.2%, n = 65). Adjusted odds ratios were 1.9 (0.7-4.9), 2.7 (0.9-7.6), and 2.1 (0.8-5.7), respectively. Adjusted odds ratios for symptoms of cough were 2.7 (1.2-6.5) for the low, 5.2 (2.1-13.0) for the high 'green dust' and 3.3 (1.4-7.9) for the high 'dry dust' exposure groups. Moreover, eye and nose irritations were significantly more prevalent in the high and low exposure groups. CONCLUSIONS: Working in pine sawmilling is associated with an increased prevalence of asthma and cough symptoms and eye and nose irritation.

A case-control study of risk factors for asthma in New Zealand children.

OBJECTIVE: As in other English-speaking countries, asthma is a major and increasing health problem in New Zealand. This study examined the risk factors for asthma in children aged 7-9. METHODS: Cases and controls were randomly selected from participants in the Wellington arm of the International Study of Asthma and Allergies in Childhood (ISAAC). Cases were children with a previous diagnosis of asthma and current medication use (n=233), and controls were children with no history of wheezing and no diagnosis of asthma (n=241). RESULTS: After controlling for confounders, factors significantly associated with asthma were maternal (OR=3.36, 95% CI 1.88-5.99) and paternal asthma (OR-2.67, 95% CI 1.42-5.02), and male sex (OR=1.81, 95% CI 1.17-2.81). Children from social classes 5 and 6 or with unemployed parents (OR=2.32, 95% CI 1.22-4.44) were significantly more likely to have asthma than children in social classes 1 and 2. There was no significant association between having polio vaccination (OR=2.48, 95% CI 0.83-7.41), hepatitis B vaccination (OR=0.66, 95% CI 0.42-1.04) or measles/mumps/rubella vaccination (OR=1.43, 95% CI 0.85-2.41) and asthma. CONCLUSIONS: This study has confirmed the associations of family history and lower socio-economic status with current asthma in 7-9 year old children. The role of vaccinations requires further research.

Gene discovery and gene function assignment in filamentous fungi.

Filamentous fungi are a large group of diverse and economically important microorganisms. Large-scale gene disruption strategies developed in budding yeast are not applicable to these organisms because of their larger genomes and lower rate of targeted integration (TI) during transformation. We developed transposon-arrayed gene knockouts (TAGKO) to discover genes and simultaneously create gene disruption cassettes for subsequent transformation and mutant analysis. Transposons carrying a bacterial and fungal drug resistance marker are used to mutagenize individual cosmids or entire libraries in vitro. Cosmids are annotated by DNA sequence analysis at the transposon insertion sites, and cosmid inserts are liberated to direct insertional mutagenesis events in the genome. Based on saturation analysis of a cosmid insert and insertions in a fungal cosmid library, we show that TAGKO can be used to rapidly identify and mutate genes. We further show that insertions can create alterations in gene expression, and we have used this approach to investigate an amino acid oxidation pathway in two important fungal phytopathogens.

Changes in work practice after a respiratory health survey among welders in New Zealand.

AIMS: To assess changes in work practice among eight New Zealand engineering sites, following a study of occupational respiratory symptoms in welders two years previously. METHODS: In 1996, we found that an acute decrease in lung function was more common in welders working without local exhaust ventilation. Findings were reported back to management, study participants and the media. Two years later we re-visited the eight welding sites. RESULTS: Of the eight engineering sites, two had local exhaust ventilation present in both Study 1 and Study 2, one site had installed local exhaust ventilation in part of the site since Study 1 and one site had moved to larger premises. The remaining four sites had no exhaust ventilation or change to the workplace between studies. Five welders (12.8%) used respiratory protection in both Study 1 and Study 2, seven welders (18%) used respiratory protection in Study 1 but not Study 2, four welders (10.3%) did not have respiratory protection in Study 1 but did in Study 2 and nine welders (23.1%) did not use respiratory protection at all in Study 1 or Study 2. CONCLUSION: Further effort is required to ensure that such studies lead to significant improvements in the work environment.

Asthma morbidity 6 yrs after an effective asthma self-management programme in a Maori community.

A 6-month Maori community-based asthma self-management programme, involving a "credit card" asthma self-management plan, has previously been shown to be an effective and acceptable system for reducing asthma morbidity. The effectiveness of the asthma self-management programme and participants' self-management behaviour was assessed 6 yrs after the formal end of the programme. Participants were surveyed at the time of enrollment, and 1, 2, and 6 yrs after completing the programme. In each survey, participants were questioned on markers of asthma morbidity and use of medical services during the previous 12 months. Self-management behaviour was assessed using a questionnaire at 2 years and 6 yrs. Of the 69 original participants, 47 (68%) were surveyed after 6 yrs. They generally had reduced severe asthma morbidity and emergency use of health services from baseline. In particular, the proportion who had an emergency visit to a general practitioner had decreased from 41% to 18% (p=0.02). However, the percentage of nights woken due to asthma had returned to preintervention levels, and the proportion of participants taking prescribed regular inhaled steroid had decreased from 91% to 53% (p<0.001). Compared with 2 yrs after completion of the asthma programme, self-management behaviour had also deteriorated, with 29% versus 73% (p<0.001) using their peak flow meter daily when their asthma was "getting bad" and 41% versus 86% (p<0.001) using the "credit card" plan to increase the amount of inhaled steroids in the last year. Although the programme participants were still experiencing reduced morbidity from their asthma 6 yrs after the end of the self-management programme, the benefits were less than those observed at 2 yrs. These findings suggest that under-recognition and under-treatment of asthma with appropriate amounts of inhaled steroids is a major factor contributing to asthma morbidity in this indigenous rural community. To obtain enduring benefits from a self-management system of care continued reinforcement of self-management skills seems to be an essential component of any follow-up.

Occupational respiratory symptoms in New Zealand hairdressers.

BACKGROUND: A study of occupational respiratory symptoms in hairdressers was carried out in 26 salons in New Zealand. METHODS: A questionnaire was administered to 100 hairdressers and 106 office and shop workers, recording respiratory symptoms, demographic data, and smoking habits. Pulmonary function was measured before each shift. RESULTS: Hairdressers had a higher prevalence of asthma symptoms, diagnosed asthma, and asthma attacks in the previous 12 months, but these differences reduced markedly when adjusted for age, gender and smoking. Hairdressers had a significantly lower pulmonary function, even after adjustment for smoking, but this difference was entirely due to differences between hairdressers and office workers and there were no such differences between hairdressers and shop workers. CONCLUSIONS: The excess symptom prevalence in hairdressers was largely due to the high smoking rates. Mean pulmonary function was lower in hairdressers but this finding requires further study.

Indoor environment, atopy and the risk of the asthma in children in New Zealand.

The objective of this study was to examine the relationship between the indoor environment, atopy and asthma in 7-9-year-old children. Cases and controls were randomly selected from children who participated in the International Study of Asthma and Allergies in Childhood (ISAAC) in Wellington, New Zealand. Cases were children with a previous diagnosis of asthma and current medication use (n = 233) and controls were children with no history of wheezing and no diagnosis of asthma (n = 241). Information was recorded about the indoor environment during the first year of life and currently. Dust was sampled from floors and beds and Der p 1 and Fel d 1 measured using enzyme-linked immunosorbent assays. Skin-prick tests were performed with eight common allergens. Sensitization to Dermatophagoides farinae (OR = 3.19; 95% CI 1.74-5.84), Dermatophagoides pteronyssinus (OR = 2.06; 95% CI 1.16-3.65) and cat (OR = 3.89; 95% CI 1.06-14.30) were independently associated with current asthma. The use of a sheepskin in the first year of life (OR = 1.91; 95% CI 1.11-3.33) was also independently associated with current asthma but current Der p 1 levels showed no association with current asthma. Exposures in early life may be more important than current exposures in determining asthma at age 7-9 years. Prospective studies are needed in New Zealand to determine the relative importance of early life exposures to Der p 1 and other risk factors for asthma.

Family size, infections, and asthma prevalence in New Zealand children.

We conducted a prevalence case-control study to investigate the relation between family composition, infection, and development of asthma at age 7-9 years. Potential cases (399) and controls (398) were selected from the Wellington, NZ, arm of the International Study of Asthma and Allergies in Childhood, a population-based prevalence study. Further screening questions restricted cases to children with a diagnosis of asthma and current medication use (N = 233) and restricted controls to children without a history of wheezing and no diagnosis of asthma (N = 241). After controlling for confounders (including infections, atopy, and socioeconomic status), family size was strongly related to asthma. Having no siblings [prevalence odds ratio (POR) = 2.51; 95% confidence interval (CI) = 1.05-6.01] or one sibling (POR = 1.86; 95% CI = 1.14-3.03) was associated with an increased risk of asthma compared with having more than one sibling. Parent-reported rubeola infection (and possibly other similar viral exanthems) was independently associated with a decreased risk of asthma (POR = 0.48; 95% CI = 0.27-0.83), but reported pertussis infection (POR = 1.57; 95% CI = 0.58-4.24) and day care attendance in the first year of life (POR = 1.81; 95% CI = 0.93-3.51) were not strongly associated with increased risks of asthma.

Two year follow up of pulmonary function values among welders in New Zealand.

OBJECTIVES: To examine whether welding is a risk factor for an accelerated decline in pulmonary function. METHODS: 2 Year follow up of pulmonary function and respiratory symptoms among 54 welders and 38 non-welders in eight New Zealand welding sites. RESULTS: There were no significant differences in age, height, smoking habits, ethnicity, or total time in industrial work between welders and non-welders. No overall differences were noted in the changes of pulmonary function variables between the two study groups. However, when the comparison was restricted to smokers, welders had a significantly greater (p = 0.02) annual decline (88.8 ml) in FEV1 than non-welders, who had a slight non-significant annual increase (34.2 ml). Also, welders without respiratory protection or local exhaust ventilation while welding had a greater annual decline both in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) than welders with protection (p = 0.001 and 0.04, respectively). Among welders a significant association was found between the acute across shift change and the annual decline in FEV1. Chronic bronchitis was more common among welders (24%) than non-welders (5%). Only one welder (2%) but eight non-welders (21%) reported having asthma. CONCLUSIONS: Welders who smoked and welders working without local exhaust ventilation or respiratory protection have an increased risk of accelerated decline in FEV1.

Asthma and allergy in New Zealand farmers.

AIMS: To examine the prevalence of symptoms of asthma and allergy in different farming groups in New Zealand. METHODS: A postal questionnaire was sent to a random sample of 2,500 farmers throughout New Zealand. RESULTS: The response rate was 77% (1,706 of 2,203 eligibles). The 12-month period prevalence of current asthma was 11.8% overall, compared with 15% in the general population. Asthma prevalence was higher for horse breeders/groomers (16.5%), pig farmers (18.2%), poultry farmers (17.4%), and those working with oats (17.4%). Asthma was also significantly elevated among those working with cleaning powders (14.7%). Women were more likely to report current asthma than were men (OR 1.8, 95% CI 1.3-2.5). Hay fever was significantly higher in deer and crop farmers, and farmers working with horses and goats; eczema was higher for goat and deer farmers. CONCLUSIONS: The lower overall prevalence of asthma in farmers may be due to the healthy worker effect. Among farmers, the types of farming associated with an elevated prevalence of asthma and allergy in New Zealand are deer and goat farming, working with horses, poultry, pigs, and crop farming. Females reported more current asthma than males.

Long-term benefits for Mäori of an asthma self-management program in a Mäori community which takes a partnership approach.

BACKGROUND: In 1991, an intervention trial of the efficacy of an asthma self-management plan was carried out in partnership with a rural Mäori community. The program relied on Mäori community health workers and other health professionals working in partnership, was delivered through clinics in traditional Mäori community centres and Mäori processes were followed throughout. The plan was shown to be effective in reducing asthma morbidity. OBJECTIVE: To assess whether the long-term benefits of the program extent beyond reduced asthma morbidity and the extent to which any additional benefits may be related to the partnership approach employed by the program. METHOD: Forty-seven (68%) of the original program participants were surveyed in August 1997. Participants were questioned on the program's impact in areas such as cultural development, health service access and lifestyle. RESULTS: In addition to the improvements in asthma morbidity, the program was found to have four key benefits: cultural affirmation; improved access to other health services; a greater sense of control for participants; and positive impacts on the extended family. CONCLUSIONS: The program's benefits extended beyond reduced asthma morbidity and were not due simply to the introduction of the asthma self-management plan but also to the partnership approach employed by the program. IMPLICATIONS: The study provides support for providing public health services for indigenous communities that take a partnership approach, utilise community expertise and are delivered in a way that is consistent with each community's cultural processes.