1,002 research outputs found
Graphical evidence for the solar coronal structure during the Maunder minimum: Comparative study of the total eclipse drawings in 1706 and 1715
We discuss the significant implications of three eye-witness drawings of the total solar eclipse on 1706 May 12 in comparison with two on 1715 May 3, for our understanding of space climate change. These events took place just after what has been termed the "deep Maunder Minimum"but fall within the "extended Maunder Minimum"being in an interval when the sunspot numbers start to recover. Maria Clara Eimmert's image in 1706 is particularly important because she was both a highly accomplished astronomical observer and an excellent artist: It was thought lost and was only re-discovered in 2012. Being the earliest coronal drawings of observational value yet identified, these drawings corroborate verbal accounts a corona without significant streamers, seen at totality of this and another eclipse event in 1652 during the Maunder Minimum. The graphical evidence implies that the coronal solar magnetic field was not lost but significantly weakened and the lack of coronal structure means there was little discernable open flux (either polar or at lower latitudes) even during the recovery phase of the Maunder Minimum. These observations provide evidence for a different state of oscillation of the solar dynamo, and hence behaviour of the Sun, in comparison with that during normal solar cycle minima (when a streamer belt between two polar coronal holes is visible) or near normal sunspot maxima (when coronal structure is caused by coronal holes at all latitudes) even to observers without a telescope
Assessment of Elemental Concentrations in Streams of the New Lead Belt in Southeastern Missouri, 2002â05
Concerns about possible effects of lead-mining activities on the water quality of federally protected streams located in southeastern Missouri prompted a suite of multidisciplinary studies to be conducted by the U.S. Geological Survey. As part of this investigation, a series of biological studies were initiated in 2001 for streams in the current mining region and the prospecting area. In this report, results are examined for trace elements and other selected chemical measurements in sediment, surface water, and sediment interstitial (pore) water sampled between 2002 and 2005 in association with these biological studies. Compared to reference sites, fine sediments collected downstream from mining areas were enriched in metals by factors as large as 75 for cadmium, 62 for cobalt, 171 for nickel, 95 for lead, and 150 for zinc. Greatest metal concentrations in sediments collected in 2002 were from sites downstream from mines on Strother Creek, Courtois Creek, and the West Fork Black River. Sediments from sites on Bee Fork, Logan Creek, and Sweetwater Creek also were noticeably enriched in lead. Sediments in Clearwater Lake, at least 75 kilometers downstream from mining activity, had metal concentrations that were 1.5 to 2.1 times greater than sediments in an area of the lake with no upstream mining activity. Longitudinal sampling along three streams in 2004 indicated that sediment metal concentrations decreased considerably a few kilometers downstream from mining activities; however, in Strother Creek some metals were still enriched by a factor of five or more as far as 13 kilometers downstream from the Buick tailings impoundment. Compared with 2002 samples, metals concentrations were dramatically lower in sediments collected in 2004 at an upper West Fork Black River site, presumably because beneficiation operations at the West Fork mill ceased in 2000. Concentrations of metals and sulfate in sediment interstitial (pore) waters generally tracked closely with metal concentrations in sediments. Metals, including cobalt, nickel, lead, and zinc, were elevated substantially in laboratory-produced pore waters of fine sediments collected near mining operations in 2002 and 2004. Passive diffusion samplers (peepers) buried 4 to 6 centimeters deep in riffle-run stream sediments during 2003 and 2005 had much lower pore-water metal concentrations than the laboratory-produced pore waters of fine sediments collected in 2002 and 2004, but each sampling method produced similar patterns among sites. The combined mean concentration of lead in peeper samples from selected sites located downstream from mining activities for six streams was about 10-fold greater than the mean of the reference sites. In most instances, metals concentrations in surface water and peeper water were not greatly different, indicating considerable exchange between the surface water and pore water at the depths and locations where peepers were situated. Passive sampling probes used to assess metal lability in pore waters of selected samples during 2004 sediment toxicity tests indicated that most of the filterable lead in the laboratory-prepared pore water was relatively non-labile, presumably because lead was complexed by organic matter, or was present as colloidal species. In contrast, large percentages of cobalt and nickel in pore water appeared to be labile. Passive integrative samplers deployed in surface water for up to 3 weeks at three sites in July 2005 confirmed the presence of elevated concentrations of labile metals downstream from mining operations on Strother Creek and, to a lesser extent, Bee Fork. These samplers also indicated a considerable increase in metal loadings occurred for a few days at the Strother Creek site, which coincided with moderate increases in stream discharges in the area
A macroinvertebrate assessment of Ozark streams located in leadâzinc mining areas of the Viburnum Trend in southeastern Missouri, USA
The Viburnum Trend leadâzinc mining subdistrict is located in the southeast Missouri portion of the Ozark Plateau. In 2003 and 2004, we assessed the ecological effects of mining in several watersheds in the region. We included macroinvertebrate surveys, habitat assessments, and analysis of metals in sediment, pore water, and aquatic biota. Macroinvertebrates were sampled at 21 sites to determine aquatic life impairment status (full, partial, or nonsupport) and relative biotic condition scores. Macroinvertebrate biotic condition scores were significantly correlated with cadmium, nickel, lead, zinc, and specific conductance in 2003 (r = â0.61 to â0.68) and with cadmium, lead, and pore water toxic units in 2004 (r = â0.55 to â0.57). Reference sites were fully supporting of aquatic life and had the lowest metals concentrations and among the highest biotic condition scores in both years. Sites directly downstream from mining and related activities were partially supporting, with biotic condition scores 10% to 58% lower than reference sites. Sites located greater distances downstream from mining activities had intermediate scores and concentrations of metals. Results indicate that elevated concentrations of metals originating from mining activities were the underlying cause of aquatic life impairment in several of the streams studied. There was a general concurrence among the adversely affected sites in how the various indicators responded to the mining activities during the overall study
PrP genotypes of captive and free-ranging Rocky Mountain elk (\u3ci\u3eCervus elaphus nelsoni\u3c/i\u3e) with chronic wasting disease
The PrP gene encodes the putative causative agent of the transmissible spongiform encephalopathies (TSEs), a heterogeneous group of fatal, neurodegenerative disorders including human CreutzfeldtâJakob disease, bovine spongiform encephalopathy, ovine scrapie and chronic wasting disease (CWD) of North American deer and elk. Polymorphisms in the PrP gene are associated with variations in relative susceptibility, pathological lesion patterns, incubation times and clinical course of TSEs of humans, mice and sheep. Sequence analysis of the PrP gene from Rocky Mountain elk showed only one amino acid change (Met to Leu at cervid codon 132). Homozygosity for Met at the corresponding polymorphic site (Met to Val) in humans (human codon 129) predisposes exposed individuals to some forms of CreutzfeldtâJakob disease. In this study, Rocky Mountain elk homozygous for PrP codon 132 Met were over-represented in both free-ranging and farm-raised CWD-affected elk when compared to unaffected control groups
Making Sense of a New Transport System: An Ethnographic Study of the Cambridgeshire Guided Busway
An increase in public transport use has the potential to contribute to improving population health, and there is growing interest in innovative public transport systems. Yet how new public transport infrastructure is experienced and integrated (or not) into daily practice is little understood. We investigated how the Cambridgeshire Guided Busway, UK, was used and experienced in the weeks following its opening, using the method of participant observation (travelling on the busway and observing and talking to passengers) and drawing on Normalization Process Theory to interpret our data. Using excerpts of field notes to support our interpretations, we describe how the ease with which the new transport system could be integrated into existing daily routines was important in determining whether individuals would continue to use it. It emerged that there were two groups of passengers with different experiences and attitudes. Passengers who had previously travelled frequently on regular bus services did not perceive the new system to be an improvement; consequently, they were frustrated that it was differentiated from and not coherent with the regular system. In contrast, passengers who had previously travelled almost exclusively by car appraised the busway positively and perceived it to be a novel and superior form of travel. Our rich qualitative account highlights the varied and creative ways in which people learn to use new public transport and integrate it into their everyday lives. This has consequences for the introduction and promotion of future transport innovations. It is important to emphasise the novelty of new public transport, but also the ways in which its use can become ordinary and routine. Addressing these issues could help to promote uptake of other public transport interventions, which may contribute to increasing physical activity and improving population health. © 2013 Jones et al
What Training, Support, and Resourcing Do Health Professionals Need to Support People Using a Closed-Loop System? A Qualitative Interview Study with Health Professionals Involved in the Closed Loop from Onset in Type 1 Diabetes (CLOuD) Trial.
Background: We explored health professionals' views about the training, support, and resourcing needed to support people using closed-loop technology in routine clinical care to help inform the development of formal guidance. Methods: Interviews were conducted with health professionals (nâ=â22) delivering the Closed Loop from Onset in Type 1 Diabetes (CLOuD) trial after they had â„6 months' experience of supporting participants using a closed-loop system. Data were analyzed descriptively. Results: Interviewees described how, compared with other insulin regimens, teaching and supporting individuals to use a closed-loop system could be initially more time-consuming. However, they also noted that after an initial adjustment period, users had less need for initiating contact with the clinical team compared with people using pumps or multiple daily injections. Interviewees highlighted how a lessened need for ad hoc clinical input could result in new challenges; specifically, they had fewer opportunities to reinforce users' diabetes knowledge and skills and detect potential psychosocial problems. They also observed heightened anxiety among some parents due to the constant availability of data and unrealistic expectations about the system's capabilities. Interviewees noted that all local diabetes teams should be empowered to deliver closed-loop system care, but stressed that health professionals supporting closed-loop users in routine care will need comprehensive technology training and standardized clinical guidance. Conclusion: These findings constitute an important starting point for the development of formal guidance to support the rollout of closed-loop technology. Our recommendations, if actioned, will help limit the potential additional burden of introducing closed-loop systems in routine clinical care and help inform appropriate user education and support.NIHR
Wellcome Trust Strategic Award (100574/Z/12/Z
Structural hierarchy as a key to complex phase selection in Al-Sm
Investigating the unknown structure of the complex cubic phase, previously observed to crystallize from melt-spun amorphous Alâ10 at.% Sm alloy, we determine the structure in full site-occupancy detail, highlighting several critical structural features that govern the far-from-equilibrium phase selection pathway. Using an efficient genetic algorithm combining molecular dynamics, density functional theory, and x-ray diffraction, the structure is clearly identified as body-centered cubic ImÂŻ3m (No. 229) with âŒ140 atoms per cubic unit cell and a lattice parameter of 1.4 nm. The complex structure is further refined to elucidate the detailed site occupancy, revealing full Sm occupancy on 6b sites and split Sm/Al occupancy on 16f sites. Based on the refined site occupancy associated with the experimentally observed phase, we term this phase ÉâAl60Sm11(bcc), corresponding to the limiting situation when all 16f sites are occupied by Sm. However, it should be recognized that the range of solubility enabled by split occupancy at Sm sites is an important feature in phase selection under experimental conditions, permitting an avenue for transition with little or no chemical partitioning. Our analysis shows that the ÉâAl60Sm11(bcc) exhibits a â3-6-6-1â first-shell packing around Sm centers on 16f sites, the same dominant motif exhibited by the undercooled liquid. The coincident motif supports the notion that liquid/glass ordering at high undercooling may give rise to topological invariants between the noncrystalline and crystalline states that provide kinetic pathways to metastable phases that are not accessible during near-equilibrium processing
CAR-T cell. the long and winding road to solid tumors
Adoptive cell therapy of solid tumors with reprogrammed T cells can be considered the "next generation" of cancer hallmarks. CAR-T cells fail to be as effective as in liquid tumors for the inability to reach and survive in the microenvironment surrounding the neoplastic foci. The intricate net of cross-interactions occurring between tumor components, stromal and immune cells leads to an ineffective anergic status favoring the evasion from the host's defenses. Our goal is hereby to trace the road imposed by solid tumors to CAR-T cells, highlighting pitfalls and strategies to be developed and refined to possibly overcome these hurdles
Rosiglitazone as an option for patients with acromegaly: a case series
<p>Abstract</p> <p>Introduction</p> <p>In the patient with acromegaly, pituitary surgery is the therapeutic standard. Despite undergoing surgery, a significant number of patients with acromegaly continue to have uncontrolled growth hormone secretion. These patients require other treatments such as external irradiation and/or drug therapy.</p> <p>Case presentation</p> <p>We present the clinical and laboratory responses to six months of treatment with rosiglitazone in four cases. In all four cases, the patients had persistent growth hormone overproduction despite previous surgical treatment and other conventional therapy. Case 1 is a 57-year-old Caucasian woman, case 2 is a 51-year-old Hispanic man, case 3 is a 32-year-old Hispanic woman, and case 4 is a 36-year-old Hispanic man. In three of these patients, basal and nadir growth hormone and insulin-like growth factor 1 levels were significantly decreased (<it>P </it>< 0.05 and <it>P </it>< 0.01, respectively).</p> <p>Conclusion</p> <p>Rosiglitazone could be a treatment option in select patients with acromegaly.</p
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