The death of massive stars - II. Observational constraints on the progenitors of Type Ibc supernovae

The progenitors of many Type II core-collapse supernovae (SNe) have now been identified directly on pre-discovery imaging. Here, we present an extensive search for the progenitors of Type Ibc SNe in all available pre-discovery imaging since 1998. There are 12 Type Ibc SNe with no detections of progenitors in either deep ground-based or Hubble Space Telescope archival imaging. The deepest absolute BVR magnitude limits are between -4 and - 5 mag. We compare these limits with the observed Wolf-Rayet population in the Large Magellanic Cloud and estimate a 16 per cent probability that we have failed to detect such a progenitor by chance. Alternatively, the progenitors evolve significantly before core-collapse or we have underestimated the extinction towards the progenitors. Reviewing the relative rates and ejecta mass estimates from light-curve modelling of Ibc SNe, we find both incompatible with Wolf-Rayet stars with initial masses >25 M⊙ being the only progenitors. We present binary evolution models that fit these observational constraints. Stars in binaries with initial masses ≲ 20 M⊙ lose their hydrogen envelopes in binary interactions to become low-mass helium stars. They retain a low-mass hydrogen envelope until ≈104 yr before core-collapse; hence, it is not surprising that Galactic analogues have been difficult to identify.

Vaccinations and childhood type 1 diabetes mellitus: a meta-analysis of observational studies

Aims/hypothesis The aim of this study was to investigate the association between routine vaccinations and the risk of childhood type 1 diabetes mellitus by systematically reviewing the published literature and performing meta-analyses where possible.

Methods A comprehensive literature search was performed of MEDLINE and EMBASE to identify all studies that compared vaccination rates in children who subsequently developed type 1 diabetes mellitus and in control children. ORs and 95% CIs were obtained from published reports or derived from individual patient data and then combined using a random effects meta-analysis.

Results In total, 23 studies investigating 16 vaccinations met the inclusion criteria. Eleven of these contributed to meta-analyses which included data from between 359 and 11,828 childhood diabetes cases. Overall, there was no evidence to suggest an association between any of the childhood vaccinations investigated and type 1 diabetes mellitus. The pooled ORs ranged from 0.58 (95% CI 0.24, 1.40) for the measles, mumps and rubella (MMR) vaccination in five studies up to 1.04 (95% CI 0.94, 1.14) for the haemophilus influenza B (HiB) vaccination in 11 studies. Significant heterogeneity was present in most of the pooled analyses, but was markedly reduced when analyses were restricted to study reports with high methodology quality scores. Neither this restriction by quality nor the original authors’ adjustments for potential confounding made a substantial difference to the pooled ORs.

Conclusions/interpretation This study provides no evidence of an association between routine vaccinations and childhood type 1 diabetes.

Methotrexate polyglutamates as a potential marker of adherence to long-term therapy in children with juvenile idiopathic arthritis and juvenile dermatomyositis: an observational, cross-sectional study

Introduction: Methotrexate (MTX) is a cornerstone of treatment in a wide variety of inflammatory conditions, including juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis (JDM). However, owing to its narrow therapeutic index and the considerable interpatient variability in clinical response, monitoring of adherence to MTX is important. The present study demonstrates the feasibility of using methotrexate polyglutamates (MTXPGs) as a biomarker to measure adherence to MTX treatment in children with JIA and JDM.
Methods: Data were collected prospectively from a cohort of 48 children (median age 11.5 years) who received oral or subcutaneous (SC) MTX therapy for JIA or JDM. Dried blood spot samples were obtained from children by finger pick at the clinic or via self- or parent-led sampling at home, and they were analysed to determine the variability in MTXPG concentrations and assess adherence to MTX therapy.
Results: Wide fluctuations in MTXPG total concentrations (>2.0-fold variations) were found in 17 patients receiving stable weekly doses of MTX, which is indicative of nonadherence or partial adherence to MTX therapy. Age (P = 0.026) and route of administration (P = 0.005) were the most important predictors of nonadherence to MTX treatment. In addition, the study showed that MTX dose and route of administration were significantly associated with variations in the distribution of MTXPG subtypes. Higher doses and SC administration of MTX produced higher levels of total MTXPGs and selective accumulation of longer-chain MTXPGs (P < 0.001 and P < 0.0001, respectively).
Conclusions: Nonadherence to MTX therapy is a significant problem in children with JIA and JDM. The present study suggests that patients with inadequate adherence and/or intolerance to oral MTX may benefit from SC administration of the drug. The clinical utility of MTXPG levels to monitor and optimise adherence to MTX in children has been demonstrated.Trial Registration: ISRCTN Registry identifier: ISRCTN93945409 . Registered 2 December 2011.

Assessment of cataract surgical outcomes in settings where follow-up is poor:PRECOG, a multicentre observational study

Background: Poor follow-up after cataract surgery in developing countries makes assessment of operative quality uncertain. We aimed to assess two strategies to measure visual outcome: recording the visual acuity of all patients 3 or fewer days postoperatively (early postoperative assessment), and recording that of only those patients who returned for the final follow-up examination after 40 or more days without additional prompting. Methods: Each of 40 centres in ten countries in Asia, Africa, and Latin America recruited 40-120 consecutive surgical cataract patients. Operative-eye best-corrected visual acuity and uncorrected visual acuity were recorded before surgery, 3 or fewer days postoperatively, and 40 or more days postoperatively. Clinics logged whether each patient had returned for the final follow-up examination without additional prompting, had to be actively encouraged to return, or had to be examined at home. Visual outcome for each centre was defined as the proportion of patients with uncorrected visual acuity of 6/18 or better minus the proportion with uncorrected visual acuity of 6/60 or worse, and was calculated for each participating hospital with results from the early assessment of all patients and the late assessment of only those returning unprompted, with results from the final follow-up assessment for all patients used as the standard. Findings: Of 3708 participants, 3441 (93%) had final follow-up vision data recorded 40 or more days after surgery, 1831 of whom (51% of the 3581 total participants for whom mode of follow-up was recorded) had returned to the clinic without additional prompting. Visual outcome by hospital from early postoperative and final follow-up assessment for all patients were highly correlated (Spearman's r_s=0·74, p<0·0001). Visual outcome from final follow-up assessment for all patients and for only those who returned without additional prompting were also highly correlated (r_s=0·86, p<0·0001), even for the 17 hospitals with unprompted return rates of less than 50% (r_s=0·71, p=0·002). When we divided hospitals into top 25%, middle 50%, and bottom 25% by visual outcome, classification based on final follow-up assessment for all patients was the same as that based on early postoperative assessment for 27 (68%) of 40 centres, and the same as that based on data from patients who returned without additional prompting in 31 (84%) of 37 centres. Use of glasses to optimise vision at the time of the early and late examinations did not further improve the correlations. Interpretation: Early vision assessment for all patients and follow-up assessment only for patients who return to the clinic without prompting are valid measures of operative quality in settings where follow-up is poor. Funding: ORBIS International, Fred Hollows Foundation, Helen Keller International, International Association for the Prevention of Blindness Latin American Office, Aravind Eye Care System. © 2013 Congdon et al. Open Access article distributed under the terms of CC BY.

Dietary Micronutrient Intake and Micronutrient Status in Patients With Chronic Stable Heart Failure: An Observational Study.

BACKGROUND: Observational studies suggest that patients with heart failure have a tendency to a reduced status of a number of micronutrients and that this may be associated with an adverse prognosis. A small number of studies also suggest that patients with heart failure may have reduced dietary intake of micronutrients, a possible mechanism for reduced status.

OBJECTIVE: The aims of this study were to assess dietary micronutrient intake and micronutrient status in a group of patients with heart failure.

METHODS: Dietary intake was assessed in 79 outpatients with chronic stable heart failure with a reduced ejection fraction using a validated food frequency questionnaire. Blood concentrations of a number of micronutrients, including vitamin D, were measured in fasting blood samples, drawn at the time of food frequency questionnaire completion.

RESULTS: More than 20% of patients reported intakes less than the reference nutrient intake or recommended intake for riboflavin, vitamin D, vitamin A, calcium, magnesium, potassium, zinc, copper, selenium, and iodine. More than 5% of patients reported intakes less than the lower reference nutrient intake or minimum recommended intake for riboflavin, vitamin D, vitamin A, calcium, magnesium, potassium, zinc, selenium, and iodine. Vitamin D deficiency (plasma total 25-hydroxy-vitamin D concentration <50 nmol/L) was observed in 75.6% of patients.

CONCLUSIONS: Vitamin D deficiency was common in this group of patients with heart failure. Based on self-reported dietary intake, a substantial number of individuals may not have been consuming enough vitamin D and a modest number of individuals may not have been consuming enough riboflavin, vitamin A, calcium, magnesium, potassium, zinc, copper, selenium, or iodine to meet their dietary needs.

Epidemiology of painful procedures performed in neonates: A systematic review of observational studies

Procedural pain in neonates has been a concern in the last two decades. The purpose of this review was to provide a critical appraisal and a synthesis of the published epidemiological studies about procedural pain in neonates admitted to intensive care units. The aims were to determine the frequency of painful procedures and pain management interventions as well as to identify their predictors. Academic Search, CINAHL, LILACS, Medic Latina, MEDLINE and SciELO databases were searched for observational studies on procedural pain in neonates admitted to intensive care units. Studies in which neonatal data could not be extracted from the paediatric population were excluded. Eighteen studies were included in the review. Six studies with the same study duration, the first 14 days of the neonate life or admission in the unit of care, identified 6832 to 42,413 invasive procedures, with an average of 7.5-17.3 per neonate per day. The most frequent procedures were heel lance, suctioning, venepuncture and insertion of peripheral venous catheter. Pharmacological and nonpharmacological approaches were inconsistently applied. Predictors of the frequency of procedures and analgesic use included the neonate's clinical condition, day of unit stay, type of procedure, parental presence and pain assessment. The existence of pain protocols was not a predictor of analgesia. Painful procedures were performed frequently and often with inadequate pain management. Unlike neonate clinical factors, organizational factors may be modified to promote a context of care more favourable to pain management. © 2015 European Pain Federation - EFIC®

A Meteorological and Snow observational data set from Snoqualmie Pass (921 m), Washington Cascades, U.S.

We introduce a quality controlled observational atmospheric, snow, and soil data set from Snoqualmie Pass, Washington, U.S.A., to enable testing of hydrometeorological and snow process representations within a rain-snow transitional climate where existing observations are sparse and limited. Continuous meteorological forcing (including air temperature, total precipitation, wind speed, specific humidity, air pressure, short- and longwave irradiance) are provided at hourly intervals for a 24-year historical period (water years 1989-2012) and at half-hourly intervals for a more-recent period (water years 2013-2015), separated based on the availability of observations. Additional observations include 40-years of snow board new snow accumulation, multiple measurements of total snow depth, and manual snow pits, while more recent years include sub-daily surface temperature, snowpack drainage, soil moisture and temperature profiles, and eddy co-variance derived turbulent heat flux. This data set is ideal for testing hypotheses about energy balance, soil and snow processes in the rain-snow transition zone. Plots of live data can be found here: http://depts.washington.edu/mtnhydr/cgi/plot.cgi

Preterm nutritional intake and MRI phenotype at term age: a prospective observational study

Objective: To describe (1) the relationship between nutrition and the preterm-at-term infant phenotype, (2) phenotypic differences between preterm-at-term infants and healthy term born infants and (3) relationships between somatic and brain MRI outcomes. Design: Prospective observational study. Setting: UK tertiary neonatal unit. Participants: Preterm infants (<32 weeks gestation) (n=22) and healthy term infants (n=39) Main outcome measures: Preterm nutrient intake; total and regional adipose tissue (AT) depot volumes; brain volume and proximal cerebral arterial vessel tortuosity (CAVT) in preterm infants and in term infants. Results: Preterm nutrition was deficient in protein and high in carbohydrate and fat. Preterm nutrition was not related to AT volumes, brain volume or proximal CAVT score; a positive association was noted between human milk intake and proximal CAVT score (r=0.44, p=0.05). In comparison to term infants, preterm infants had increased total adiposity, comparable brain volumes and reduced proximal CAVT scores. There was a significant negative correlation between deep subcutaneous abdominal AT volume and brain volume in preterm infants (r=−0.58, p=0.01). Conclusions: Though there are significant phenotypic differences between preterm infants at term and term infants, preterm macronutrient intake does not appear to be a determinant. Our preliminary data suggest that (1) human milk may exert a beneficial effect on cerebral arterial vessel tortuosity and (2) there is a negative correlation between adiposity and brain volume in preterm infants at term. Further work is warranted to see if our findings can be replicated and to understand the causal mechanisms.

Women's Attachment as a Predictor of Pain During Labour and Post-Delivery: a Prospective Observational Study

INTRODUCTION: Labour is considered to be one of the most painful and significant experiences in a woman's life. The aim of this study was to examine whether women's attachment style is a predictor of the pain experienced throughout labour and post-delivery. MATERIAL AND METHODS:Thirty-two pregnant women were assessed during the third trimester of pregnancy and during labour. Adult attachment was assessed with the Adult Attachment Scale ' Revised. The perceived intensity of labour pain was measured using a visual analogue scale for pain in the early stage of labour, throughout labour and post-delivery. RESULTS:Women with an insecure attachment style reported more pain at 3 cm of cervical dilatation (p < 0.05), before the administration of analgesia (p < 0.01) and post-delivery (p < 0.05) than those securely attached. In multivariate models, attachment style was a significant predictor of labour pain at 3 cm of cervical dilatation and before the first administration of analgesia but not of the perceived pain post-delivery. DISCUSSION: These findings confirm that labour pain is influenced by relevant psychological factors and suggest that a woman's attachment style may be a risk factor for greater pain during labour. CONCLUSION:Future studies in the context of obstetric pain may consider the attachment style as an indicator of individual differences in the pain response during labour. This may have important implications in anaesthesiology and to promote a relevant shift in institutional practices and therapeutic procedures.

The occurrence of intra-operative hypotension varies between hospitals: observational analysis of more than 147,000 anaesthesia.

BACKGROUND: Hypotension, a common intra-operative incident, bears an important potential for morbidity. It is most often manageable and sometimes preventable, which renders its study important. Therefore, we aimed at examining hospital variations in the occurrence of intra-operative hypotension and its predictors. As secondary endpoints, we determined to what extent hypotension relates to the risk of post-operative incidents and death. METHODS: We used the Anaesthesia Databank Switzerland, built on routinely and prospectively collected data on all anaesthesias in 21 hospitals. The three outcomes were assessed using multi-level logistic regression models. RESULTS: Among 147,573 anaesthesias, hypotension ranged from 0.6% to 5.2% in participating hospitals, and from 0.3% up to 12% in different surgical specialties. Most (73.4%) were minor single events. Age, ASA status, combined general and regional anaesthesia techniques, duration of surgery and hospitalization were significantly associated with hypotension. Although significantly associated, the emergency status of the surgery had a weaker effect. Hospitals' odds ratios for hypotension varied between 0.12 and 2.50 (P < or = 0.001), even after adjusting for patient and anaesthesia factors, and for type of surgery. At least one post-operative incident occurred in 9.7% of the procedures, including 0.03% deaths. Intra-operative hypotension was associated with a higher risk of post-operative incidents and death. CONCLUSION: Wide variations remain in the occurrence of hypotension among hospitals after adjustment for risk factors. Although differential reporting from hospitals may exist, variations in anaesthesia techniques and blood pressure maintenance may also have contributed. Intra-operative hypotension is associated with morbidities and sometimes death, and constant vigilance must thus be advocated.

Indicators for the total number of melanocytic naevi : an adjunct for screening campaigns. Observational study on 292 patients.

BACKGROUND: The presence of multiple melanocytic naevi is a strong risk factor for melanoma. Use of the whole body naevus count to identify at-risk patients is impractical. OBJECTIVES: To (i) identify a valid anatomical predictor of total naevus count; (ii) determine the number of naevi that most accurately predict total naevus count above 25, 50 and 100; and (iii) evaluate determinants of multiple melanocytic naevi and atypical naevi. METHODS: Clinical data from 292 consecutive Spanish patients consulting for skin lesions requiring debriding were collected throughout 2009 and 2010. Correlations between site-specific and whole body naevus counts were analysed. Cut-offs to predict total naevus counts were determined using the area under the receiver operating characteristic curve. RESULTS: The studied population was young (median age 31 years, interquartile range 28-43). The naevus count on the right arm correlated best with the total nevus count (R(2) 0·80 for men, 0·86 for women). Presence of at least five naevi on the right arm was the strongest determinant of a total naevus count above 50 [odds ratio (OR) 34·4, 95% confidence interval (CI) 13·9-85·0] and of having at least one atypical naevus (OR 5·7, 95% CI 2·4-13·5). Cut-off values of 6, 8 and 11 naevi on the right arm best predicted total naevus count above 25, 50 and 100, respectively. CONCLUSIONS: Our results support the arm as a practical and reliable site to estimate the total naevus count when screening or phenotyping large populations. Threshold values for the number of naevi on the arm are proposed to help identify patients for melanoma screening.

Head-to-head comparison of length of stay, patients' outcome and satisfaction in Switzerland before and after SwissDRG-Implementation in 2012 in 2012: an observational study in two tertiary university centers.

On 1 January 2012 Swiss Diagnosis Related Groups (DRG), a new uniform payment system for in-patients was introduced in Switzerland with the intention to replace a "cost-based" with a "case-based" reimbursement system to increase efficiency. With the introduction of the new payment system we aim to answer questions raised regarding length of stay as well as patients' outcome and satisfaction. This is a prospective, two-centre observational cohort study with data from University Hospital Basel and the Cantonal Hospital Aarau, Switzerland, from January to June 2011 and 2012, respectively. Consecutive in-patients with the main diagnosis of either community-acquired pneumonia, exacerbation of COPD, acute heart failure or hip fracture were included. A questionnaire survey was sent out after discharge investigating changes before and after SwissDRG implementation. Our primary endpoint was LOS. Of 1,983 eligible patients 841 returned the questionnaire and were included into the analysis (429 in 2011, 412 in 2012). The median age was 76.7 years (50.8% male). Patients in the two years were well balanced in regard to main diagnoses and co-morbidities. Mean LOS in the overall patient population was 10.0 days and comparable between the 2011 cohort and the 2012 cohort (9.7 vs 10.3; p = 0.43). Overall satisfaction with care changed only slightly after introduction of SwissDRG and remained high (89.0% vs 87.8%; p = 0.429). Investigating the influence of the implementation of SwissDRG in 2012 regarding LOS patients' outcome and satisfaction, we found no significant changes. However, we observed some noteworthy trends, which should be monitored closely.

Patients' understanding of blood tests and attitudes to HIV screening in the emergency department of a Swiss teaching hospital: a cross-sectional observational study.

BACKGROUND: In Switzerland, patients may undergo "blood tests" without being informed what these are screening for. Inadequate doctor-patient communication may result in patient misunderstanding. We examined what patients in the emergency department (ED) believed they had been screened for and explored their attitudes to routine (non-targeted) human immunodeficiency virus (HIV) screening. METHODS: Between 1st October 2012 and 28th February 2013, a questionnaire-based survey was conducted among patients aged 16-70 years old presenting to the ED of Lausanne University Hospital. Patients were asked: (1) if they believed they had been screened for HIV; (2) if they agreed in principle to routine HIV screening and (3) if they agreed to be HIV tested during their current ED visit. RESULTS: Of 466 eligible patients, 411 (88%) agreed to participate. Mean age was 46 ± 16 years; 192 patients (47%) were women; 366 (89%) were Swiss or European; 113 (27%) believed they had been screened for HIV, the proportion increasing with age (p ≤0.01), 297 (72%) agreed in principle with routine HIV testing in the ED, and 138 patients (34%) agreed to be HIV tested during their current ED visit. CONCLUSION: In this ED population, 27% believed incorrectly they had been screened for HIV. Over 70% agreed in principle with routine HIV testing and 34% agreed to be tested during their current visit. These results demonstrate willingness among patients concerning routine HIV testing in the ED and highlight a need for improved doctor-patient communication about what a blood test specifically screens for.

Observational learning of motor skills : Looking for optimal models

L’observation d’un modèle pratiquant une habileté motrice promeut l’apprentissage de l’habileté en question. Toutefois, peu de chercheurs se sont attardés à étudier les caractéristiques d’un bon modèle et à mettre en évidence les conditions d’observation pouvant optimiser l’apprentissage. Dans les trois études composant cette thèse, nous avons examiné les effets du niveau d’habileté du modèle, de la latéralité du modèle, du point de vue auquel l’observateur est placé, et du mode de présentation de l’information sur l’apprentissage d’une tâche de timing séquentielle composée de quatre segments. Dans la première expérience de la première étude, les participants observaient soit un novice, soit un expert, soit un novice et un expert. Les résultats des tests de rétention et de transfert ont révélé que l’observation d’un novice était moins bénéfique pour l’apprentissage que le fait d’observer un expert ou une combinaison des deux (condition mixte). Par ailleurs, il semblerait que l’observation combinée de modèles novice et expert induise un mouvement plus stable et une meilleure généralisation du timing relatif imposé comparativement aux deux autres conditions. Dans la seconde expérience, nous voulions déterminer si un certain type de performance chez un novice (très variable, avec ou sans amélioration de la performance) dans l’observation d’une condition mixte amenait un meilleur apprentissage de la tâche. Aucune différence significative n’a été observée entre les différents types de modèle novices employés dans l’observation de la condition mixte. Ces résultats suggèrent qu’une observation mixte fournit une représentation précise de ce qu’il faut faire (modèle expert) et que l’apprentissage est d’autant plus amélioré lorsque l’apprenant peut contraster cela avec la performance de modèles ayant moins de succès. Dans notre seconde étude, des participants droitiers devaient observer un modèle à la première ou à la troisième personne. L’observation d’un modèle utilisant la même main préférentielle que soi induit un meilleur apprentissage de la tâche que l’observation d’un modèle dont la dominance latérale est opposée à la sienne, et ce, quel que soit l’angle d’observation. Ce résultat suggère que le réseau d’observation de l’action (AON) est plus sensible à la latéralité du modèle qu’à l’angle de vue de l’observateur. Ainsi, le réseau d’observation de l’action semble lié à des régions sensorimotrices du cerveau qui simulent la programmation motrice comme si le mouvement observé était réalisé par sa propre main dominante. Pour finir, dans la troisième étude, nous nous sommes intéressés à déterminer si le mode de présentation (en direct ou en vidéo) influait sur l’apprentissage par observation et si cet effet est modulé par le point de vue de l’observateur (première ou troisième personne). Pour cela, les participants observaient soit un modèle en direct soit une présentation vidéo du modèle et ceci avec une vue soit à la première soit à la troisième personne. Nos résultats ont révélé que l’observation ne diffère pas significativement selon le type de présentation utilisée ou le point de vue auquel l’observateur est placé. Ces résultats sont contraires aux prédictions découlant des études d’imagerie cérébrale ayant montré une activation plus importante du cortex sensorimoteur lors d’une observation en direct comparée à une observation vidéo et de la première personne comparée à la troisième personne. Dans l’ensemble, nos résultats indiquent que le niveau d’habileté du modèle et sa latéralité sont des déterminants importants de l’apprentissage par observation alors que le point de vue de l’observateur et le moyen de présentation n’ont pas d’effets significatifs sur l’apprentissage d’une tâche motrice. De plus, nos résultats suggèrent que la plus grande activation du réseau d’observation de l’action révélée par les études en imagerie mentale durant l’observation d’une action n’induit pas nécessairement un meilleur apprentissage de la tâche.