Robust damping controller design in power systems with superconducting magnetic energy storage devices

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Major and trace element and multiple sulfur isotope composition of sulfides from the Paleoproterozoic Surda copper deposit, Singhbhum Shear Zone, India: Implications for the mineralization processes

The present study combines major and trace element composition, and sulfur (S) isotope data of pyrite and chacopyrite from the Surda copper sulfide deposit in the Singhbhum Shear Zone, the most important copper and uranium producing belt (Singhbhum Cu-U Belt) in India. Three textural and compositional types of both pyrite and chalcopyrite were distinguished; unzoned to partially zoned Pyrite IA with high Co (up to 54900 ppm) and low Ni content is earliest, followed by oscillatory zoned Pyrite IB with high As (up to 25600 ppm) and Co (up to 46800 ppm), bothoccurring in pyrite I + chalcopyrite I + pyrrhotite + magnetite + apatite vein; Cobaltite-type substitution (Fe1-xCox)(S1-xAsx)2 is suggested for Pyrite IB. Gold occurs in Pyrite I as minor “invisible” gold and as electrum inclusions. It also occurs along with Cu, Mn, Ni, Hg, Ag, Pb, Sb, Zn, Ce, Y, U, and Th in micro-fractures that transgress the primary zoning pattern defined by As, Co, and Ni in Pyrite IB. The early inclusion-rich chalcopyrite generation (Chalcopyrite I) contains high concentration of Zn and Se, and minor to trace amounts of Co, Ni, Hg, Pb, Sb, Te, and Bi, appeared in between Pyrite I and II.Low Co, high Ni (up to 37700 ppm) content Pyrite II, and inclusion-free Chalcopyrite II enriched in Co, Ni, Hg, Bi, Mn, Ag, Sb, V, and Pb are cogenetic, and occurring in pyrite II + pyrrhotite + pentlandite + chalcopyrite II ± violarite vein. Low Co and Ni containing Pyrite III + Chalcopyrite III occur mainly as disseminated grains. The relative timing of formation of Pyrite II + Chalcopyrite II with PyriteIII + Chalcopyrite III remains uncertain. Pyrite + chalcopyrite textures indicate that all pyrite + chalcopyrite formed at some time prior to the end of deformation and metamorphism. Both in situ and mineral separates of all pyrite types and associated chalcopyrite yield a narrow range of positive δ34S values (between +3.8 to +6.9 ‰) suggesting sulfur being derived from a similar source. Consistent positive δ34S values and other circumstantial evidence indicate that most sulfur was derived from seawater sulfate or modified seawater (brine/evaporite). Δ33S values revealed mass dependent fractionation (MDF) signature. It is proposed that incorporation of MDF sulfur of the mineralization event in Paleoproterozoic Singhbhum Cu-U Belt took place after the great oxidation event. The high Se concentrations (260 to 400 ppm) and ∑Se/∑S ratios for both Pyrite I and II from Surda deposit (4.4 to 5.7 x10-4) suggest a low temperature of the Cu–rich ores (250°-350°C), and precipitation from a metalliferous fluid with a high ∑Se/∑S ratio (10-4 to 10-3) consistent with igneous input of these elements

Differential impact of simultaneous migration on coevolving hosts and parasites

BACKGROUND: The dynamics of antagonistic host-parasite coevolution are believed to be crucially dependent on the rate of migration between populations. We addressed how the rate of simultaneous migration of host and parasite affected resistance and infectivity evolution of coevolving meta-populations of the bacterium Pseudomonas fluorescens and a viral parasite (bacteriophage). The increase in genetic variation resulting from small amounts of migration is expected to increase rates of adaptation of both host and parasite. However, previous studies suggest phages should benefit more from migration than bacteria; because in the absence of migration, phages are more genetically limited and have a lower evolutionary potential compared to the bacteria. RESULTS: The results supported the hypothesis: migration increased the resistance of bacteria to their local (sympatric) hosts. Moreover, migration benefited phages more than hosts with respect to 'global' (measured with respect to the whole range of migration regimes) patterns of resistance and infectivity, because of the differential evolutionary responses of bacteria and phage to different migration regimes. Specifically, we found bacterial global resistance peaked at intermediate rates of migration, whereas phage global infectivity plateaued when migration rates were greater than zero. CONCLUSION: These results suggest that simultaneous migration of hosts and parasites can dramatically affect the interaction of host and parasite. More specifically, the organism with the lower evolutionary potential may gain the greater evolutionary advantage from migration

Predictors of failed attendances in a multi-specialty outpatient centre using electronic databases.

BACKGROUND: Failure to keep outpatient medical appointments results in inefficiencies and costs. The objective of this study is to show the factors in an existing electronic database that affect failed appointments and to develop a predictive probability model to increase the effectiveness of interventions. METHODS: A retrospective study was conducted on outpatient clinic attendances at Tan Tock Seng Hospital, Singapore from 2000 to 2004. 22864 patients were randomly sampled for analysis. The outcome measure was failed outpatient appointments according to each patient's latest appointment. RESULTS: Failures comprised of 21% of all appointments and 39% when using the patients' latest appointment. Using odds ratios from the mutliple logistic regression analysis, age group (0.75 to 0.84 for groups above 40 years compared to below 20 years), race (1.48 for Malays, 1.61 for Indians compared to Chinese), days from scheduling to appointment (2.38 for more than 21 days compared to less than 7 days), previous failed appointments (1.79 for more than 60% failures and 4.38 for no previous appointments, compared with less than 20% failures), provision of cell phone number (0.10 for providing numbers compared to otherwise) and distance from hospital (1.14 for more than 14 km compared to less than 6 km) were significantly associated with failed appointments. The predicted probability model's diagnostic accuracy to predict failures is more than 80%. CONCLUSION: A few key variables have shown to adequately account for and predict failed appointments using existing electronic databases. These can be used to develop integrative technological solutions in the outpatient clinic

Allergic enterocolitis and protein-losing enteropathy as the presentations of manganese leak from an ingested disk battery: A case report

<p>Abstract</p> <p>Introduction</p> <p>Disk battery ingestions can lead to serious complications including airway or digestive tract perforation, blood vessel erosions, mediastinitis, and stricture formation.</p> <p>Case presentation</p> <p>We report a 20-month-old Caucasian child who developed eosinophilic enterocolitis and subsequent protein-losing enteropathy from manganese that leaked from a lithium disk battery. The disk battery was impacted in her esophagus for 10 days resulting in battery corrosion. We postulate that this patient's symptoms were due to a manganese leak from the 'retained' disk battery; this resulted in an allergic response in her gut and protein-losing enteropathy. Her symptoms improved gradually over the next 2 weeks with conservative management.</p> <p>Conclusion</p> <p>This is the first case report to highlight the potential complication of allergic enterocolitis and protein-losing enteropathy secondary to ingested manganese. Clinicians should be vigilant about this rare complication in managing patients with disk battery ingestions.</p

Erythroderma: A clinical study of 97 cases

BACKGROUND: Erythroderma is a rare skin disorder that may be caused by a variety of underlying dermatoses, infections, systemic diseases and drugs. METHODS: We reviewed the clinical, laboratory and biopsy material of 97 patients diagnosed with erythroderma who were treated in our department over a 6-year period (1996 through 2002). RESULTS: The male-female ratio was 1.85:1. The mean age at diagnosis was 46.2 years. The most common causative factors were dermatoses (59.7%), followed by drug reactions (21.6%), malignancies (11.3%) and idiopathic causes (7.2%). Carbamazepine was the most common drug (57.1%). The best clinicopathologic correlation was found in cutaneous T-cell lymphoma and pityriasis rubra pilaris related erythroderma. Apart from scaling and erythema that were present in all patients, pruritus was the most common finding (97.5%), followed by fever (33.6%), lymphadenopathy (21.3%), edema (14.4%) and hyperkeratosis (7.2%). CONCLUSION: This study outlines that underlying etiologic factors of erythroderma may show geographic variations. Our series had a high percentage of erythroderma secondary to preexisting dermatoses and a low percentage of idiopathic cases. There was no HIV-infected patient among our series based on multiple serum antibody tests. The clinical features of erythroderma were identical, irrespective of the etiology. The onset of the disease was usually insidious except in drug-induced erythroderma, where it was acute. The group associated with the best prognosis was that related to drugs

Are osteoporotic fractures being adequately investigated?: A questionnaire of GP & orthopaedic surgeons

BACKGROUND: To investigate the current practice of Orthopaedic Surgeons & General Practitioners (GP) when presented with patients who have a fracture, with possible underlying Osteoporosis. METHODS: Questionnaires were sent to 140 GPs and 140 Orthopaedic Surgeons. The participants were asked their routine clinical practice with regard to investigation of underlying osteoporosis in 3 clinical scenarios. 55 year old lady with a low trauma Colles fracture 60 year old lady with a vertebral wedge fracture 70 year old lady with a low trauma neck of femur fracture. RESULTS: Most doctors agreed that patients over 50 years old with low trauma fractures required investigation for osteoporosis, however, most surgeons (56%, n = 66) would discharge patients with low trauma Colles fracture without requesting or initiating investigation for osteoporosis. Most GPs (67%, n = 76) would not investigate a similar patient for osteoporosis, unless prompted by the Orthopaedic Surgeon or patient. More surgeons (71%, n= 83) and GPs (64%, n = 72) would initiate investigations for osteoporosis in a vertebral wedge fracture, but few surgeons (35%, n = 23) would investigate a neck of femur fracture patient after orthopaedic treatment. CONCLUSION: Most doctors know that fragility fractures in patients over 50 years old require investigation for Osteoporosis; however, a large population of patients with osteoporotic fractures are not being given the advantages of secondary prevention

TDP-43 as a potential biomarker for amyotrophic lateral sclerosis:a systematic review and meta-analysis

Abstract Background Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) are incurable, progressive and fatal neurodegenerative diseases with patients variably affected clinically by motor, behavior, and cognitive deficits. The accumulation of an RNA-binding protein, TDP-43, is the most significant pathological finding in approximately 95% of ALS cases and 50% of FTD cases, and discovery of this common pathological signature, together with an increasing understanding of the shared genetic basis of these disorders, has led to FTD and ALS being considered as part of a single disease continuum. Given the widespread aggregation and accumulation of TDP-43 in FTD-ALS spectrum disorder, TDP-43 may have potential as a biomarker in these diseases. Methods We therefore conducted a systematic review and meta-analysis to evaluate the diagnostic utility of TDP-43 detected in the cerebrospinal fluid (CSF) of patients with FTD-ALS spectrum disorder. Results From seven studies, our results demonstrate that patients with ALS have a statistically significantly higher level of TDP-43 in CSF (effect size 0.64, 95% CI: 0.1–1.19, p = 0.02). Conclusions These data suggest promise for the use of CSF TDP-43 as a biomarker for ALS

Interaction of Virstatin with Human Serum Albumin: Spectroscopic Analysis and Molecular Modeling

Virstatin is a small molecule that inhibits Vibrio cholerae virulence regulation, the causative agent for cholera. Here we report the interaction of virstatin with human serum albumin (HSA) using various biophysical methods. The drug binding was monitored using different isomeric forms of HSA (N form ∼pH 7.2, B form ∼pH 9.0 and F form ∼pH 3.5) by absorption and fluorescence spectroscopy. There is a considerable quenching of the intrinsic fluorescence of HSA on binding the drug. The distance (r) between donor (Trp214 in HSA) and acceptor (virstatin), obtained from Forster-type fluorescence resonance energy transfer (FRET), was found to be 3.05 nm. The ITC data revealed that the binding was an enthalpy-driven process and the binding constants Ka for N and B isomers were found to be 6.09×105 M−1 and 4.47×105 M−1, respectively. The conformational changes of HSA due to the interaction with the drug were investigated from circular dichroism (CD) and Fourier Transform Infrared (FTIR) spectroscopy. For 1∶1 molar ratio of the protein and the drug the far-UV CD spectra showed an increase in α- helicity for all the conformers of HSA, and the protein is stabilized against urea and thermal unfolding. Molecular docking studies revealed possible residues involved in the protein-drug interaction and indicated that virstatin binds to Site I (subdomain IIA), also known as the warfarin binding site

Packages of Care for Epilepsy in Low- and Middle-Income Countries

In the second in a series of six articles on packages of care for mental health disorders in low- and middle-income countries, Caroline Mbuba and Charles Newton discuss treatment for epilepsy