1,021 research outputs found
The Effects of Possible Contamination on the Radiocarbon Dating of the Dead Sea Scrolls II: Empirical Methods to Remove Castor Oil and Suggestions for Redating
While kept at the Rockefeller Museum in East Jerusalem, many Dead Sea Scroll fragments were exposed to castor oil by the original team of editors in the course of cleaning the parchments. Castor oil must be regarded as a serious contaminant in relation to radiocarbon dating. If modern castor oil is present and is not removed prior to dating, the 14C dates will be skewed artificially towards modern values. Earlier, it was shown that the standard AAA pretreatment procedure used in the 2 previous studies dating Dead Sea Scroll samples is not capable of removing castor oil from parchment samples. In the present work, we show that it is unlikely that castor oil reacts with the amino acids of the parchment proteins, a finding which leaves open the possibility of devising a cleaning method that can effectively remove castor oil. We then present 3 different pretreatment protocols designed to effectively remove castor oil from parchment samples. These involve 3 different cleaning techniques: extraction with supercritical CO2, ultrasound cleaning, and Soxhlet extraction—each with their own advantages and disadvantages. Our data show that the protocol involving Soxhlet extraction is the best suited for the purpose of decontaminating the Dead Sea Scrolls, and we recommend that this protocol be used in further attempts to 14C date the Dead Sea Scrolls. If such an attempt is decided on by the proper authorities, we propose a list of Scroll texts, which we suggest be redated in order to validate the 14C dates done earlier.
Stress in agile software development : practices and outcomes
Stress is an important workplace issue, affecting both the health of individuals, and the health of organizations. Early advocacy for Agile Software Development suggested it might help avoid stress, with practices that emphasize a sustainable pace, and self-organizing teams. Our analysis of a 2014 survey, however, suggested that stress might still be commonplace in Agile teams, especially for those with less experience. We also noticed that newcomers to Agile emphasized technical, rather than collaborative, practices, and speculated this might explain the stress. We explored this in our analysis of a follow-up survey conducted in 2016, and report our findings in this paper. We show that there are a variety of factors involved, and that avoiding stress is associated with both collaborative and technical practices, and a range of outcomes
Linking ecological health to co-occurring organic and inorganic chemical stressors in a groundwater-fed stream system
Sonne AT, Rasmussen JJ, Höss S, Traunspurger W, Bjerg PL, McKnight US. Linking ecological health to co-occurring organic and inorganic chemical stressors in a groundwater-fed stream system. SCIENCE OF THE TOTAL ENVIRONMENT. 2018;642:1153-1162.Freshwaters are among the most endangered ecosystems worldwide, due predominantly to excessive anthropogenic practices compromising the future provisioning of ecosystem services. Despite increased awareness of the role of multiple stressors in accounting for ecological degradation in mixed land-use stream systems, risk assessment approaches applicable in field settings are still required. This study provides a first indication for ecological consequences of the interaction of organic and inorganic chemical stressors, not typically evaluated together, which may provide a missing link enabling the reconnection of chemical and ecological findings. Specifically, impaired ecological conditions - represented by lower abundance of meiobenthic individuals - were observed in the hyporheic zone where a contaminant groundwater plume discharged to the stream. These zones were characterized by high xenobiotic organic concentrations, and strongly reduced groundwater (e.g. elevated dissolved iron and arsenic) linked to the dissolution of iron hydroxides (iron reduction) caused by the degradation of xenobiotic compounds in the plume. Further research is still needed to separate whether impact is driven by a combined effect of organic and inorganic stressors impacting the ecological communities, or whether the conditions - when present simultaneously - are responsible for enabling a specific chemical stressors availability (e.g. trace metals), and thus toxicity, along the study stream. Regardless, these findings suggest that benthic meioinvertebrates are promising indicators for supporting biological assessments of stream systems to sufficiently represent impacts resulting from the co-occurrence of stressors in different stream compartments. Importantly, identification of the governing circumstances is crucial for revealing key patterns and impact drivers that may be needed in correctly prioritizing stressor impacts in these systems. This study further highlights the importance of stream-aquifer interfaces for investigating chemical stressor effects in multiple stressor systems. This will require holistic approaches for linking contaminant hydrogeology and eco(toxico)logy in order to positively influence the sustainable management of water resources globally. (C) 2018 Elsevier B.V. All rights reserved
Genetic and environmental influence on thyroid gland volume and thickness of thyroid isthmus: a twin study.
Objectives Decreased thyroid volume has been related to increased prevalence of thyroid cancer.Subjects and methods One hundred and fourteen Hungarian adult twin pairs (69 monozygotic, 45 dizygotic) with or without known thyroid disorders underwent thyroid ultrasound. Thickness of the thyroid isthmus was measured at the thickest portion of the gland in the midline using electronic calipers at the time of scanning. Volume of the thyroid lobe was computed according to the following formula: thyroid height*width*depth*correction factor (0.63).Results Age-, sex-, body mass index- and smoking-adjusted heritability of the thickness of thyroid isthmus was 50% (95% confidence interval [CI], 35 to 66%). Neither left nor right thyroid volume showed additive genetic effects, but shared environments were 68% (95% CI, 48 to 80%) and 79% (95% CI, 72 to 87%), respectively. Magnitudes of monozygotic and dizygotic co-twin correlations were not substantially impacted by the correction of covariates of body mass index and smoking. Unshared environmental effects showed a moderate influence on dependent parameters (24-50%).Conclusions Our analysis support that familial factors are important for thyroid measures in a general twin population. A larger sample size is needed to show whether this is because of common environmental (e.g. intrauterine effects, regional nutrition habits, iodine supply) or genetic effects
Stability and collective excitations of a two-component Bose-condensed gas: a moment approach
The dynamics of a two-component dilute Bose gas of atoms at zero temperature
is described in the mean field approximation by a two-component
Gross-Pitaevskii Equation. We solve this equation assuming a Gaussian shape for
the wavefunction, where the free parameters of the trial wavefunction are
determined using a moment method. We derive equilibrium states and the phase
diagrams for the stability for positive and negative s-wave scattering lengths,
and obtain the low energy excitation frequencies corresponding to the
collective motion of the two Bose condensates.Comment: 7 pages, 6 figure
Emergency Call versus General Practitioner Requested Ambulances – Patient Mortality, Disease Severity and Pattern
Morten Breinholt Søvsø,1 Rasmine Birch Haurum,2 Trine Hagelskær Ebbesen,2 Ann Øster Rasmussen,2 Logan Morgan Ward,3 Mads Lause Mogensen,3 Erika Frischknecht Christensen,1 Tim Alex Lindskou1 1Centre for Prehospital and Emergency Research at Danish Centre for Health Services Research; Aalborg University Hospital and Department of Clinical Medicine, Aalborg University, Gistrup, Denmark; 2Department of Health, Science and Technology, Aalborg University, Gistrup, Denmark; 3Treat Systems ApS, Aalborg, DenmarkCorrespondence: Tim Alex Lindskou, Centre for Prehospital and Emergency Research, Aalborg University Hospital and Department of Clinical Medicine, Aalborg University, Selma Lagerløfs Vej 249, Gistrup, 9260, Denmark, Tel +45 23274523, Email [email protected]: Ambulance requests by general practitioners for primary care patients (GP-requested) are often omitted in studies on increased demand within emergency care but may comprise a substantial patient group. We aimed to assess acute severity, intensive care unit (ICU) admission, and diagnostic pattern, including comorbidity, and mortality among GP-requested ambulance patients, compared to emergency call ambulance patients. Our hypothesis was that emergency call patients had more severe health issues than GP-requested ambulance patients.Methods: Historic population-based cohort study of ambulance patients in the North Denmark Region, 2016– 2020. Hospital contact data including diagnoses, ambulance data, vital signs and vital status was linked using each patient’s unique identification number. Primary outcome measure was mortality within 1, 7, and 30 days. Secondary outcomes were disease severity expressed as modified National Early Warning Score (NEWS2), and ICU admission. Admission status and hospital diagnostic pattern, including comorbidity were described and compared.Results: We included 255,487 patients. GP-requested patients (N = 119,361, 46.7%) were older (median years [IQR] 73 [58– 83] versus 61 [37– 76]) and more had moderate/severe comorbidity (11.9%, N = 13,806 versus 4.9%, N = 6145) than the emergency call patients. Prehospital mNEWS2 median scores were lower for GP-requested patients. For both groups, mNEWS2 was highest among patients aged 66+. GP-requested patients had higher 30-day mortality (9.0% (95% CI: 8.8– 9.2), N = 8996) than emergency call patients (5.2% (95% CI: 5.1– 5.4), N = 6727). Circulatory (12.0%, 11,695/97,112) and respiratory diseases (11.6%, 11,219/97,112) were more frequent among GP-requested patients than emergency call patients ((10.7%, 12,640/118,102) and (5.8%, 6858/118,102)). The highest number of deaths was found for health issues ‘circulatory diseases’ in the emergency call group and ‘other factors’ followed by “respiratory diseases” in the GP-requested group.Conclusion: GP-requested patients constituted nearly half of the EMS volume, they were older, with more comorbidity, had serious conditions with substantial acute severity, and a higher 30-day mortality than emergency call patients.Keywords: emergency medical services, mortality, diagnoses, early warning scores, after-hours care, primary healthcare, general practitioner
Mechanisms for reducing low back pain: a mediation analysis of a multifaceted intervention in workers in elderly care
Purpose A multifaceted workplace intervention consisting of participatory ergonomics, physical training, and cognitive–behavioural training (CBT) has shown effectiveness for reducing low back pain (LBP). However, the mechanisms of action underlying these intervention components are not well understood. Methods This was a mediation analysis of a cluster-randomised controlled trial of a multifaceted intervention in 420 workers in elderly care. Mediation analysis was carried out via structural equation modelling. Potential mediators investigated were: fear-avoidance beliefs, perceived muscle strength, use of assistive devices at work and perceived physical exertion at work. LBP outcomes assessed were: days with LBP, LBP intensity and days with bothersome LBP. Results There were no significant indirect effects of the intervention on LBP outcomes. There were significant effects of the intervention on both fear-avoidance measures [β = − 0.63, 95% CI (1.23, 0.03); β = − 1.03, 95% CI (− 1.70, − 0.34)] and the use of assistive devices [β = − 0.55, 95% CI (− 1.04, − 0.05)], but not on perceived muscle strength [β = − 0.18, 95% CI (− 0.50, 0.13)] or physical exertion [β = − 0.05, 95% CI (− 0.40, 0.31)]. The only potential mediator with a significant effect on LBP outcomes was physical exertion, which had a significant effect on LBP intensity [β = 0.14, 95% CI (0.04, 0.23)]. Conclusions A multifaceted intervention consisting of participatory ergonomics, physical training, and CBT was able to decrease fear-avoidance beliefs and increase use of assistive devices in the workplace. However, these changes did not explain the effect of any of the intervention components on days with LBP, LBP intensity and days with bothersome LBP
Imaging Oxygen Distribution in Marine Sediments. The Importance of Bioturbation and Sediment Heterogeneity
The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns:the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment–water interface
- …