bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geology, mineralogy, and sulfur isotopes of the Mowana copper deposit, Matsitama Schist Belt, NE Botswana
Authors: Kooganne Amogelang , Imai Akira , Agangi Andrea , Takahashi Ryohei 
Published: June 2021

AbstractThe Mowana hydrothermal Cu deposit is located within the Matsitama–Motloutse Complex in the southwestern part of the Zimbabwe Craton in the northeastern part of Botswana. This study aims to document the characteristics of the mineralization based on geology, quartz textures, ore mineralogy, chlorite geothermometry, and sulfur isotope analyses. The deposit is hosted by the NNE‐striking and nearly vertically dipping (70–80°) Bushman Lineament, within the graphitic schist lenses in the carbonaceous and argillaceous metasedimentary rocks of the Neoarchean to Paleoproterozoic Matsitama Sedimentary Group. The hydrothermal alteration of the host rocks is characterized by silicification, chloritization, epidotization, sericitization, hematite, and calcite alteration. Based on the alteration mineral assemblage, the main mineralization stage is attributed to near neutral pH fluids at temperatures between ~200 and ~340°C. The base metal mineralization of the Mowana deposit was evolved in at least two vein types. The first mineralization type, represented by the quartz+calcite±K‐feldspar veins and breccias is characterized by the precipitation of principal chalcopyrite with pyrite, minor bornite, and trace amounts of galena. The Type 2 veins represented by the quartz+calcite±fluorite veins, host appreciable amounts of galena. The supergene mineralization widely distributed in the shallow levels of the deposit is manifested by the significant presence of chalcocite, bornite, covellite, anglesite, malachite, and hematite. The temperature obtained from the chlorite geothermometry in the Type 1 veins indicate that the mineralization associated with chlorite alteration formed at a temperature ranging from 340 to 400°C. The ore mineral assemblage: pyrite, bornite, and chalcopyrite, paired with the chlorite geothermometry data indicate that the Type 1 veins formed at an intemediate to high sulfidation state. Sulfur isotopic ratios determined on the sulfides indicate the magmatic S and/or leaching of the host metasedimentary rocks and closed system reduction of seawater sulfate as the sources of S.
Individual and Collective Strategies to Limit the Impacts of Large Power Outages of Long Duration
Authors: Bohman Angelena D. , Abdulla Ahmed , Morgan M. Granger 
Published: June 2021

AbstractAs modern society becomes ever more dependent on the availability of electric power, the costs that could arise from individual and social vulnerability to large outages of long duration (LLD‐outages) increases. During such an outage, even a small amount of power would be very valuable. This article compares individual and collective strategies for providing limited amounts of electric power to residential customers in a hypothetical New England community during a large electric power outage of long duration. We develop estimates of the emergency load required for survival and assess the cost of strategies to address outages that last 5, 10, and 20 days in either winter or summer. We find that the cost of collective solutions could be as much as 10 to 40 times less than individual solutions (less than $2 per month per home). However, collective solutions would require community‐wide coordination, and if local distribution system lines are destroyed, only individual back‐up systems could provide contingency power until those lines are repaired. Costs might be reduced if more robust distributed generation were employed that could be operated continuously with the ability to sell power back to the grid. Our cost‐effectiveness analysis only assesses what could be done, developing estimates of preparedness cost. A decision about what should be done would require additional input from a range of stakeholders as well as some form of analytical deliberative process.
Mixed metamorphic and fluid graphite deposition in Palaeoproterozoic supracrustal rocks of the Lewisian Complex, NW Scotland
Authors: Parnell John , Brolly Connor , Boyce Adrian J. 
Published: June 2021

AbstractGraphite deposits may form alternatively by metamorphism of sedimentary rocks and from fluids. Both types occur in supracrustal successions within the Lewisian Complex of Northwest Scotland, and similarly in Palaeoproterozoic supracrustal rocks across the North Atlantic region in Canada, Greenland and Scandinavia. Carbon isotope compositions show that the graphite in Scotland had a mixed origin from metamorphism of sedimentary organic matter (schists) and the decarbonation of limestones (marbles). Raman spectroscopy shows that most of the graphite in Scotland exhibits some structural disorder, unlike the complete order in graphite vein ore deposits across the region. Exceptionally, where graphite was precipitated from fluid, in albitized rock in Tiree and Scardroy, it is fully ordered. While organic matter may survive granulite facies metamorphism without being transformed to fully ordered graphite, it can yield commercially more valuable ordered graphite when mobilized in a fluid.
A first WHO reference reagent for the detection of anti‐human platelet antigen‐15b
Authors: Sharp Giles , Poles Anthony , Studholme Lucy 
Published: June 2021

AbstractBackground and ObjectivesAlloantibodies to human platelet antigen‐15b (anti‐HPA‐15b) have been detected in mothers with foetal–neonatal alloimmune thrombocytopenia and in multiply transfused patients. Assays used to detect this antibody, which aids in disease diagnosis, can be unreliable and vary in sensitivity. The objective was to generate a stable, lyophilized anti‐HPA‐15b preparation and evaluate its suitability as a World Health Organization (WHO) reference reagent for use in the quality control of platelet alloantibody detection assays. Results from an international collaborative study to evaluate the preparation were used to assign a minimum potency at which laboratories can be expected to detect the antibody.Materials and MethodsRecalcified plasma containing anti‐HPA‐15b was aliquotted, lyophilized and coded 18/220. Twenty‐five laboratories in 16 countries tested doubling dilutions of the reconstituted material in glycoprotein‐specific assays such as the monoclonal antibody–specific immobilization of platelet antigen assay and reported the last positive (or endpoint) dilution.ResultsTwenty‐four laboratories (96%) detected antibodies with HPA‐15b specificity in preparation 18/220. Reported endpoint dilutions were normally distributed with a modal dilution of 1 in 16 and ranged from 1 in 2 to 1 in 128. Only two laboratories (8%) failed to detect anti‐HPA‐15b at 1 in 8 dilution.ConclusionsWhen diluted 1 in 8, most laboratories detected anti‐HPA‐15b in preparation 18/220 using HPA‐15bb platelets but not with HPA‐15aa platelets. The participants agreed this to be an appropriate dilution for assignment as the minimum potency. In October 2020, the WHO Expert Committee on Biological Standardization approved 18/220 as an International Reference Reagent.
Experiences With Social Participation in Group Physical Activity Programs for Older Adults
Authors: Zimmer Chantelle , McDonough Meghan H. , Hewson Jennifer , Toohey Ann , Din Cari , Crocker Peter R.E. , Bennett Erica V. 
Published: June 2021

Little is known about how social participation can be facilitated among older adults in group physical activity and its psychosocial benefits that contribute to successful aging. This study aimed to understand older adults’ experiences with social participation in group physical activity programs. Using interpretive description methodology, 16 observations, eight focus groups, and two interviews with participants unable to attend focus groups were conducted with adults 55 years and older attending programs across four recreation facilities. Group programs were found to influence social participation through (a) a meaningful context for connecting and (b) instructors’ expectations of social interaction. Social participation in these programs addressed psychosocial needs by (c) increasing social contact and interaction, (d) fostering social relationships and belonging, and (e) promoting regular engagement. Training for instructors should include balancing the physical aspects of program delivery with the social, while also considering older adults’ diverse needs and preferences for social interaction.
A record of syn-tectonic sedimentation revealed by perched alluvial fan deposits in Valles Marineris, Mars
Authors: Davis J.M. , Grindrod P.M. , Banham S.G. , Warner N.H. , Conway S.J. , Boazman S.J. , Gupta S. 
Published: June 2021

AbstractOn Mars, basins formed by tectonic processes are rare and mostly have unconstrained subsidence histories. One method for understanding this record of subsidence is through associated alluvial fans, which are sourced from uplifted areas and accumulate in downthrown basins. The source, morphology, and superposition of fan deposits can be used to reconstruct fault kinematics, the relative timing of accommodation space formation, and, in turn, the influence tectonic processes had on Martian fan formation. Here we use high-resolution orbital data sets to characterize sediment fan deposits associated with syn-tectonic sedimentation in two regions of the Valles Marineris canyons: Coprates Chasma and Juventae Chasma. These deposits comprise sediment fans on the current canyon floor and low-gradient surfaces perched several kilometers above the canyon floor. We interpret the low-gradient surfaces as remnant sediment fan deposits, which originally formed at the former canyon floor and have since been offset due to normal faulting. The preservation of vertically offset generations of sediment fan deposits supports a progressive, basinward migration of fault activity into the original hanging wall or repeat activity along a fault zone. Each episode of faulting was followed by a basinward shift in drainages, which led to fault-scarp degradation and formation of a new generation of fans. Multiple episodes of syn-tectonic sedimentation occurred during the evolution of the basins, with fluvial activity sporadically active. Our results demonstrate, for the first time on Mars, that depositional cyclicity was linked to tectonic deformation, possibly representative of regional processes throughout Valles Marineris.
Explosive caldera-forming eruptions and debris-filled vents: Gargle dynamics
Authors: Valentine Greg A. , Cole Meredith A. 
Published: June 2021

AbstractLarge explosive volcanic eruptions are commonly associated with caldera subsidence and ignimbrites deposited by pyroclastic currents. Volumes and thicknesses of intracaldera and outflow ignimbrites at 76 explosive calderas around the world indicate that subsidence is commonly simultaneous with eruption, such that large proportions of the pyroclastic currents are trapped within the developing basins. As a result, much of an eruption must penetrate its own deposits, a process that also occurs in large, debris-filled vent structures even in the absence of caldera formation and that has been termed “gargling eruption.” Numerical modeling of the resulting dynamics shows that the interaction of preexisting deposits (fill) with an erupting (juvenile) mixture causes a dense sheath of fill material to be lifted along the margins of the erupting jet. This can cause an eruption that would otherwise produce a buoyant plume and fallout deposits to instead form pyroclastic currents as the dense sheath drives pulsing jet behavior. Increasing thickness of fill amplifies the time variation in jet height. Increasing the fill grain size relative to that of the juvenile particles can result in a much higher jet due to poorer mixing between the dense sheath and the dilute jet core. In all cases, material collapses along the entire height of the dense sheath rather than from the top of a simple fountain. These gargle dynamics provide strong backing for processes that have been inferred to result in intraplinian ignimbrites and simultaneous deposition from high- and low-energy pyroclastic currents.
A new kind of invisible gold in pyrite hosted in deformation-related dislocations
Authors: Fougerouse Denis , Reddy Steven M. , Aylmore Mark , Yang Lin , Guagliardo Paul , Saxey David W. , Rickard William D.A. , Timms Nicholas 
Published: June 2021

Abstract
Mining of “invisible gold” associated with sulfides in gold ores represents a significant proportion of gold production worldwide. Gold hosted in sulfide minerals has been proposed to be structurally bound in the crystal lattice as a sulfide-gold alloy and/or to occur as discrete metallic nanoparticles. Using a combination of microstructural quantification and nanoscale geochemical analyses on a pyrite crystal from an orogenic gold deposit, we show that dislocations hosted in a deformation low-angle boundary can be enriched in Ni, Cu, As, Pb, Sb, Bi, and Au. The cumulative trace-element enrichment in the dislocations is 3.2 at% higher compared to the bulk crystal. We propose that trace elements were segregated during the migration of the dislocation following the dislocation-impurity pair model. The gold hosted in nanoscale dislocations represents a new style of invisible gold.
On the Possibility of Separating Coherent and Incoherent (Anti)neutrino Scattering on Nuclei
Authors: Bednyakov V. A. , Naumov D. V. , Titkova I. V. 
Published: June 2021

Abstract
The discovery of coherent neutrino–nucleus scattering in the COHERENT experiment opened a source of new information for fundamental investigations in the realms of neutrino and nuclear physics, as well as in the realms of searches for new physics beyond the Standard Model. Owing to substantial momentum transfers, a feature peculiar to the kinematical region of this experiment is that the effect of coherence is mixed with a sizable incoherent contribution rather than being seen in a pure form. On one hand, this leads to additional systematic uncertainties in studying the neutrino component of the coherence effect as such. On the other hand, this makes it possible to study a dynamical transition between the coherent and incoherent scattering modes and, in principle, to separate them experimentally. In our opinion, a consistent measurement of the coherent and incoherent cross sections for (anti)neutrino scattering on a nucleus in the same experiment seems a unique possibility, and its implementation would of course provide new data for neutrino physics, as well as for nuclear and new physics. In the present study, it is shown that this possibility is implementable not only in experiments that explore coherent neutrino and antineutrino scattering on various nuclei at accelerators, where the neutrino energy reaches several hundred MeV units but also in reactor experiments, where antineutrino energies do not exceed 10 MeV. The respective estimation is based on the approach that controls qualitatively a ‘‘smooth transition’’ of the cross section for (anti)neutrino–nucleus scattering from a coherent (or elastic) to an incoherent (inelastic) mode. In the former case, the target nucleus remains in the initial quantum state, while, in the latter case, its quantum state changes. Observation of a specific number of photons that have rather high energies and which remove the excitation of the nucleus after its inelastic interaction with (anti)neutrinos is proposed to be used as a signal from such an inelastic process. An upper limit on the number of such photons is obtained in this study.
Mobilization of Soil Organic Matter by Ultrafresh Water: Modeling and Assessment of the Impact on the Mobility of Heavy Metals
Authors: Grechishcheva N. Yu. , Yaroslavtsev N. V. , Kotelnikova A. D. , Ostakh O. S. , Kholodov V. A. , Zavorotny V. L. , Balaba V. I. 
Published: June 2021

Abstract
The experiments on mobilization of soil organic matter during soil washing with ultrafresh water against the background of salinity pulsing were designed and performed. Unpolluted soil and the soil artificially polluted with copper(II) were used in experiments, namely, clay loamy typical chernozem (Haplic Chernozem) of the Alekhin Central Chernozemic Nature Reserve (Kursk oblast, Russia; 51°34.207 N, 36°05.444 E) and sandy loamy soddy-podzolic soil (Albic Glossic Retisol (Loamic, Cutanic, Ochric)) from the Domodedovo district of Moscow oblast, Russia (55°17.683 N, 37°50.045 E). Soil samples were taken from the upper humus-accumulative (A1) horizon (5–15 cm). A drastic change in the composition of washing solution from fresh water to 0.1 M NaCl solution and back led to destruction of soil aggregates under the impact of osmotic pressure. Soddy-podzolic soil proved to be more resistant to destruction as compared with typical chernozem. Copper(II) was leached off from artificially contaminated samples of soddy-podzolic soil with the flow of dissolved organic matter, whereas copper leaching from typical chernozem was associated with the destruction of aggregates and release of intraaggregate organic matter. It is argued that copper (II) migration models should take into account the amount of dissolved organic matter for soddy-podzolic soil and the content of aromatic fragments in the organic matter for typical chernozem. A conceptual model of the Cu(II) leaching from contaminated soddy-podzolic soil and typical chernozem in the course of soil washing with fresh water against the background of salinity pulsing and the destruction of soil structure is constructed.
15N Natural Abundance of Soil Microbial Biomass in Alpine and Tundra Ecosystems
Authors: Makarov M. I. , Kadulin M. S. , Malysheva T. I. 
Published: June 2021

Abstract
Isotopic composition of nitrogen in soil microbial biomass (δ15Nmicr) is connected with the transformation of nitrogen compounds and with the balance of carbon and nitrogen availability for microorganisms. We have studied the dependence of δ15Nmicr on nitrogen isotopic composition in the substrate (δ15N of total and extractable nitrogen), as well as the dependence of δ15Nmicr and 15N-enrichment of microbial biomass (Δ15Nmicr = δ15Nmicr – δ15Nsubstr) on nitrogen availability parameters (the C/N ratio in soil, the N-mineralization activity, the content of extractable nitrogen, and the nitrogen use efficiency) in soils of four alpine ecosystems in the North Caucasus and four tundra ecosystems in the Khibiny Mountains. It has been shown that δ15Nmiсr varies from –0.2 to +8.4‰ and may be characterized by both 15N-enrichment and depletion (negative Δ15Nmiсr values) relative to the total and extractable soil nitrogen. As a rule, Δ15Nmicr is 1.5–3.1‰ relative to 15Ntotal and 0.6–4.8‰ relative to 15Nextr. However, under the most N-deficiency conditions in soils of mountain tundra lichen and shrub heaths, Nmicr does not accumulate an increased amount of 15N. We have not revealed a close correlation of δ15Nmicr and Δ15Nmicr with the C/N ratio. The accumulation of 15N in microbial biomass is much stronger related to N-mineralization (positively) and the nitrogen use efficiency (negatively). This testifies to the important role of microbial nitrogen dissimilation in controlling the isotopic composition of soil microbial biomass nitrogen.
Secondary metformin monotherapy failure in individuals with type 2 diabetes mellitus
Authors: Weiss Tracey , Iglay Kristy , Gulati Tania , Rajpathak Swapnil , Yang Lingfeng , Blonde Lawrence 
Published: June 2021

IntroductionTo assess secondary metformin monotherapy (MM) failure in a real-world type 2 diabetes mellitus (T2DM) cohort.Research design and methodsUsing the IQVIA Electronic Medical Record (formerly GE Centricity) database, adults with T2DM who initiated MM between January 1, 2012 and June 30, 2016 and achieved glycemic control (hemoglobin A1c (HbA1c) <7% (53 mmol/mol); index date) were analyzed. Secondary MM failure was defined in two ways: loss of glycemic control (HbA1c ≥7% (53 mmol/mol)) and treatment change (addition or switch of antihyperglycemic agent). Multivariable logistic regression models assessed the association between secondary MM failure and sociodemographic and clinical factors.ResultsThe analysis included 4775 patients initiating MM. 32.9% and 19.2% experienced secondary MM failure at 24 months measured as loss of glycemic control and treatment change, respectively. Multivariable logistic regression found that women (OR=1.3, 95% CI 1.1 to 1.5) compared with men, lower Charlson Comorbidity Index (CCI) (OR=0.89, 95% CI 0.86 to 0.93), and lower baseline HbA1c (OR=0.93, 95% CI 0.88 to 0.98) were associated with increased likelihood of loss of glycemic control. Lower CCI was associated with increased likelihood of treatment change (OR=0.78, 95% CI 0.75 to 0.82).ConclusionsThe observed frequency of secondary MM failure underscores the importance of the American Diabetes Association’s recommendation for glycemic monitoring of at least every 6 months so that timely therapeutic adjustments can be made.
Measurement and prevalence of sexual harassment in low- and middle-income countries: a systematic review and meta-analysis
Authors: Ranganathan Meghna , Wamoyi Joyce , Pearson Isabelle , Stöckl Heidi 
Published: June 2021

ObjectivesWe synthesise evidence on sexual harassment from studies in low-income and middle-income countries (LMICs) to estimate its prevalence and conduct a meta-analysis of the association between sexual harassment and depressive symptoms.MethodsWe searched eight databases. We included peer-reviewed studies published in English from 1990 until April 2020 if they measured sexual harassment prevalence in LMICs, included female or male participants aged 14 and over and conceptualised sexual harassment as an independent or dependant variable. We appraised the quality of evidence, used a narrative syntheses approach to synthesise data and conducted a random effects meta-analysis.ResultsFrom 49 included studies, 38 focused on workplaces and educational institutions and 11 on public places. Many studies used an unclear definition of sexual harassment and did not deploy a validated measurement tool. Studies either used a direct question or a series of behavioural questions to elicit information on acts considered offensive or defined as sexual harassment. Prevalence was higher in educational institutions than in workplaces although there was high heterogeneity in prevalence estimates across studies with no international comparability. This posed a challenge for calculating an overall estimate or measuring a range. Our meta-analysis showed some evidence of an association between sexual harassment and depressive symptoms (OR: 1.75; 95% CI: 1.11 to 2.76; p=0.016) although there were only three studies with a high risk of bias.ConclusionTo our knowledge, this is the first systematic review to assess measurement approaches and estimate the prevalence of sexual harassment across settings in LMICs. We also contribute a pooled estimate of the association between sexual harassment and depressive symptoms in LMICs. There is limited definitional clarity, and rigorously designed prevalence studies that use validated measures for sexual harassment in LMICs. Improved measurement will enable us to obtain more accurate prevalence estimates across different settings to design effective interventions and policies.