Polythermal structure of a Himalayan debris-covered glacier revealed by borehole thermometry

Runoff from high-elevation debris-covered glaciers represents a crucial water supply for millions of people in the Hindu Kush-Himalaya region, where peak water has already passed in places. Knowledge of glacier thermal regime is essential for predicting dynamic and geometric responses to mass balance change and determining subsurface drainage pathways, which ultimately influence proglacial discharge and hence downstream water availability. Yet, deep internal ice temperatures of these glaciers are unknown, making projections of their future response to climate change highly uncertain. Here, we show that the lower part of the ablation area of Khumbu Glacier, a high-elevation debris-covered glacier in Nepal, may contain ~56% temperate ice, with much of the colder shallow ice near to the melting-point temperature (within 0.8 °C). From boreholes drilled in the glacier’s ablation area, we measured a minimum ice temperature of −3.3 °C, and even the coldest ice we measured was 2 °C warmer than the mean annual air temperature. Our results indicate that high-elevation Himalayan glaciers are vulnerable to even minor atmospheric warming

Glacial and geomorphic effects of a supraglacial lake drainage and outburst event, Everest region, Nepal Himalaya

A set of supraglacial ponds filled rapidly between April and July 2017 on Changri Shar Glacier in the Everest region of Nepal, coalescing into a similar to 180 000 m(2) lake before sudden and complete drainage through Changri Shar and Khumbu glaciers (15-17 July). We use PlanetScope and Pleiades satellite orthoimagery to document the system's evolution over its very short filling period and to assess the glacial and proglacial effects of the outburst flood. We also use high-resolution stereo digital elevation models (DEMs) to complete a detailed analysis of the event's glacial and geomorphic effects. Finally, we use discharge records at a stream gauge 4 km downstream to refine our interpretation of the chronology and magnitude of the outburst. We infer largely subsurface drainage through both of the glaciers located on its flow path, and efficient drainage through the lower portion of Khumbu Glacier. The drainage and subsequent outburst of 1.36 +/- 0.19 x 10(6) m(3) of impounded water had a clear geomorphic impact on glacial and proglacial topography, including deep incision and landsliding along the Changri Nup proglacial stream, the collapse of shallow englacial conduits near the Khumbu terminus and extensive, enhanced bank erosion at least as far as 11 km downstream below Khumbu Glacier. These sudden changes destroyed major trails in three locations, demonstrating the potential hazard that short-lived, relatively small glacial lakes pose

Quantifying ice cliff evolution with multi-temporal point clouds on the debris-covered Khumbu Glacier, Nepal

Measurements of glacier ice cliff evolution are sparse, but where they do exist, they indicate that such areas of exposed ice contribute a disproportionate amount of melt to the glacier ablation budget. We used Structure from Motion photogrammetry with Multi-View Stereo to derive 3-D point clouds for nine ice cliffs on Khumbu Glacier, Nepal (in November 2015, May 2016 and October 2016). By differencing these clouds, we could quantify the magnitude, seasonality and spatial variability of ice cliff retreat. Mean retreat rates of 0.30–1.49 cm d−1 were observed during the winter interval (November 2015–May 2016) and 0.74–5.18 cm d−1 were observed during the summer (May 2016–October 2016). Four ice cliffs, which all featured supraglacial ponds, persisted over the full study period. In contrast, ice cliffs without a pond or with a steep back-slope degraded over the same period. The rate of thermo-erosional undercutting was over double that of subaerial retreat. Overall, 3-D topographic differencing allowed an improved process-based understanding of cliff evolution and cliff-pond coupling, which will become increasingly important for monitoring and modelling the evolution of thinning debris-covered glaciers

The Discovery of New Galaxy Members in the NGC 5044 and NGC 1052 Groups

We present the results of neutral hydrogen (HI) observations of the NGC 5044 and NGC 1052 groups, as part of a GEMS (Group Evolution Multiwavelength Study) investigation into the formation and evolution of galaxies in nearby groups. Two new group members have been discovered during a wide-field HI imaging survey conducted using the ATNF Parkes telescope. These results, as well as those from followup HI synthesis and optical imaging, are presented here. J1320-1427, a new member of the NGC 5044 Group, has an HI mass of M_HI=1.05e9Msun and M_HI/L_B=1.65 Msun/Lsun, with a radial velocity of v=2750km/s. The optical galaxy is characterised by two regions of star formation, surrounded by an extended, diffuse halo. J0249-0806, the new member of the NGC 1052 Group, has M_HI=5.4e8Msun, M_HI/L_R=1.13 Msun/Lsun and v=1450km/s. The optical image reveals a low surface brightness galaxy. We interpret both of these galaxies as irregular type, with J0249-0806 possibly undergoing first infall into the NGC 1052 group.Comment: Accepted for publication in MNRAS. 21 pages, 13 figures. Also available with high-resolution figures at http://www.astro.livjm.ac.uk/~npfm/Papers/mmb04.ps.g

Barriers and facilitators to self-management of asthma in adolescents:an interview study to inform development of a novel intervention

BACKGROUND AND OBJECTIVE: Despite literature that spans twenty years describing the barriers to asthma self-management in adolescents, successful, clinically-based interventions to address this important issue are lacking. Given the limitations of some of the previous studies, we conducted a study that aimed to gain a broader insight into barriers and facilitators to self-management of asthma by adolescents, not just adherence to treatment, and triangulated their views with those of their parents and healthcare professionals. METHODS: Focus groups and interviews were conducted separately for 28 adolescents with asthma aged 12-18 years, 14 healthcare professionals, and 12 parents. Focus groups and interviews were audio-recorded and transcripts from each participant group were analysed separately using inductive thematic analysis. We triangulated the three perspectives by comparing themes that had emerged from each analysis. RESULTS: Adolescents', parents', and healthcare professionals' views were summarised into ten related themes that included forgetting and routines, knowledge, embarrassment and confidence, communication with healthcare professionals, triggers, support at school, apathy, and taking responsibility. We found that adolescents, parents and healthcare professionals raised similar barriers and facilitators to self-management and our results provide further validation for previous studies. CONCLUSION AND CLINICAL RELEVANCE: Our study highlights that healthcare professionals may need to consider a range of psychological and contextual issues influencing adolescents' ability to effectively self-manage their asthma, in particular, how they implement treatment routines and the understanding that adolescents have of their condition and treatments. Crucially, healthcare professionals need to consider how this information is communicated and ensure they facilitate open, inclusive, two-way consultations. From this more comprehensive understanding, we have developed interventional strategies that healthcare professionals can utilise to empower adolescents to improve their asthma self-management. This article is protected by copyright. All rights reserved

Supraglacial ponds regulate runoff from Himalayan debris-covered glaciers

Meltwater and runoff from glaciers in High Mountain Asia is a vital freshwater resource for one fifth of the Earth's population. Between 13% and 36% of the region's glacierized areas exhibit surface debris cover and associated supraglacial ponds whose hydrological buffering roles remain unconstrained. We present a high-resolution meltwater hydrograph from the extensively debris-covered Khumbu Glacier, Nepal, spanning a seven-month period in 2014. Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs. Diurnally, the supraglacial pond system may store >23% of observed mean daily discharge, with mean recession constants ranging from 31 to 108 hours. Given projections of increased debris-cover and supraglacial pond extent across High Mountain Asia, we conclude that runoff regimes may become progressively buffered by the presence of supraglacial reservoirs. Incorporation of these processes is critical to improve predictions of the region's freshwater resource availability and cascading environmental effects downstream

SMEs' purchasing habits : A procurement maturity model for stakeholders

Although micro companies overpower the small and medium enterprise (SME) segment, generalizations are often with medium size companies, and therefore, there are many unknowns, especially when it comes to its buying behavior. Conformist studies and industry practices assume SMEs to be “normative” or “conservative” buyers; however, this hypothesis is untested. This article aims to scrutinize the reality, and proposes a unified model that rejects pre-containerization in buying behavior typologies, as well as selectiveness in terms of audience type, whether it is corporate, SME, or consumer. While replacing researchers’ perceptions with the audience’s, the model yields actual knowledge that can lead to audience’s beliefs in lieu of the opposite, which is used to mislead stakeholders. The study shows that SMEs also buy like individuals and spend in a similar way to consumers’, including not only “normative” and “conservative” but also “negligent” and “impulse” zones. From the research-implications perspective, future studies by behaviorists can explore why SMEs purchase in this way. Marketers may benefit from the finding that SMEs buy like individuals. In addition, SMEs may want to be conscious of their purchasing habits, and—utilizing the newly introduced “risk score” frontier—policymakers should assess the consequences of these habits at the macro level

CD4+ and CD8+ T cells and antibodies are associated with protection against Delta vaccine breakthrough infection: a nested case-control study within the PITCH study

Serological correlates of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection after vaccination ("vaccine breakthrough") have been described. However, T cell correlates of protection against breakthrough are incompletely defined, especially the specific contributions of CD4+ and CD8+ T cells. Here, 279 volunteers in the Protective Immunity from T Cells in Healthcare Workers (PITCH) UK cohort study were enrolled in a nested case-control study. Cases were those who tested SARS-CoV-2 PCR or lateral flow device (LFD) positive after two vaccine doses during the Delta-predominant era (n = 32), while controls were those who did not report a positive test or undergo anti-nucleocapsid immunoglobulin G (IgG) seroconversion during this period (n = 247). Previous SARS-CoV-2 infection prior to vaccination was associated with reduced odds of vaccine breakthrough. Using samples from 28 d after the second vaccine dose, before all breakthroughs occurred, we observed future cases had lower ancestral spike (S)- and receptor binding domain-specific IgG titers and S1- and S2-specific T cell interferon gamma (IFNγ) responses compared with controls, although these differences did not persist when individuals were stratified according to previous infection status before vaccination. In a subset of matched infection-naïve cases and controls, vaccine breakthrough cases had lower CD4+ and CD8+ IFNγ and tumor necrosis factor (TNF) responses to Delta S peptides compared with controls. For CD8+ responses, this difference appeared to be driven by reduced responses to Delta compared with ancestral peptides among cases; this reduced response to Delta peptides was not observed in controls. Our findings support a protective role for T cells against Delta breakthrough infection. IMPORTANCE Defining correlates of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine breakthrough infection informs vaccine policy for booster doses and future vaccine designs. Existing studies demonstrate humoral correlates of protection, but the role of T cells in protection is still unclear. In this study, we explore antibody and T cell immune responses associated with protection against Delta variant vaccine breakthrough infection in a well-characterized cohort of UK Healthcare Workers (HCWs). We demonstrate evidence to support a role for CD4+ and CD8+ T cells as well as antibodies against Delta vaccine breakthrough infection. In addition, our results suggest a potential role for cross-reactive T cells in vaccine breakthrough

Activin type I receptor polymorphisms and body composition in older individuals with sarcopenia-Analyses from the LACE randomised controlled trial

BACKGROUND: Ageing is associated with changes in body composition including an overall reduction in muscle mass and a proportionate increase in fat mass. Sarcopenia is characterised by losses in both muscle mass and strength. Body composition and muscle strength are at least in part genetically determined, consequently polymorphisms in pathways important in muscle biology (e.g., the activin/myostatin signalling pathway) are hypothesised to contribute to the development of sarcopenia.METHODS: We compared regional body composition measured by DXA with genotypes for two polymorphisms (rs10783486, minor allele frequency (MAF) = 0.26 and rs2854464, MAF = 0.26) in the activin 1B receptor (ACVR1B) determined by PCR in a cross-sectional analysis of DNA from 110 older individuals with sarcopenia from the LACE trial.RESULTS: Neither muscle mass nor strength showed any significant associations with either genotype in this cohort. Initial analysis of rs10783486 showed that males with the AA/AG genotype were taller than GG males (174±7cm vs 170±5cm, p = 0.023) and had higher arm fat mass, (median higher by 15%, p = 0.008), and leg fat mass (median higher by 14%, p = 0.042). After correcting for height, arm fat mass remained significantly higher (median higher by 4% padj = 0.024). No associations (adjusted or unadjusted) were seen in females. Similar analysis of the rs2854464 allele showed a similar pattern with the presence of the minor allele (GG/AG) being associated with greater height (GG/AG = 174±7 cm vs AA = 170 ±5cm, p = 0.017) and greater arm fat mass (median higher by 16%, p = 0.023). Again, the difference in arm fat remained after correction for height. No similar associations were seen in females analysed alone.CONCLUSION: These data suggest that polymorphic variation in the ACVR1B locus could be associated with body composition in older males. The activin/myostatin pathway might offer a novel potential target to prevent fat accumulation in older individuals.</p