A low cost high flux solar simulator

A low cost, high flux, large area solar simulator has been designed, built and characterized for the purpose of studying optical melting and light absorption behavior of molten salts. Seven 1500 W metal halide outdoor stadium lights are used as the light source to simulate concentrating solar power (CSP) heliostat output. Metal halide bulbs and ballasts are far less costly per-watt than typical xenon arc lamp solar simulator light sources. They provide a satisfactory match to natural sunlight; although ‘unfiltered’ metal halide lights have irradiance peaks between 800 and 1000 nm representing an additional 5% of measured energy output as compared to terrestrial solar irradiance over the same range. With the use of a secondary conical concentrator, output fluxes of approximately 60 kW/m[superscript 2] (60 suns) peak and 45 kW/m[superscript 2] (45 suns) average are achieved across a 38 cm diameter output aperture. Unique to the design of this simulator, the tilt angle and distance between the output aperture and the ground are adjustable to accommodate test receivers of varying geometry. Use of off-the-shelf structural, lighting and electrical components keeps the fabrication cost below $10,000

Design of a 100 kW Concentrated Solar Power on Demand Volumetric Receiver With Integral Thermal Energy Storage Prototype

A new concept of Thermal Energy Storage (TES) system based on current available technologies is being developed under the framework of the Masdar Institute (MI) and Massachusetts Institute of Technology (MIT) collaborative Flagship Program. The key feature of this concept lies on concentrating sun light directly on the molten salt storage tank, avoiding the necessity of pumping the salts to the top of a tower thereby avoiding thermal losses and pumping and electric tracing needs inherent in most conventional CSP plants. This Concentrated Solar Power on Demand (CSPonD) volumetric receiver/TES unit prototype will be tested in the existing MI heliostat field and beam down tower in Abu Dhabi (UAE) which will collect and redirect solar energy to an upwards-facing final optical element (FOE). These energy will be concentrated on the aperture of the prototype designed to store 400 kWh of energy allowing 16 hours of continuous production after sunset using Solar Salt (60%NaNO3 + 40%KNO3) as storage material. The tank is divided in two volumes: one cold in the bottom region, where Solar Salt is at 250 °C and another hot on the upper region, at 550 °C. A moving divider plate with active control separates both volumes. The plate includes mixing enhancement features to help with convection on the hot volume of salts. It’s expected that results will demonstrate the technical feasibility and economic viability of this concept allowing its scale up at commercial size

Telomere Length Shows No Association with BRCA1 and BRCA2 Mutation Status

This study aimed to determine whether telomere length (TL) is a marker of cancer risk or genetic status amongst two cohorts of BRCA1 and BRCA2 mutation carriers and controls. The first group was a prospective set of 665 male BRCA1/2 mutation carriers and controls (mean age 53 years), all healthy at time of enrolment and blood donation, 21 of whom have developed prostate cancer whilst on study. The second group consisted of 283 female BRCA1/2 mutation carriers and controls (mean age 48 years), half of whom had been diagnosed with breast cancer prior to enrolment. TL was quantified by qPCR from DNA extracted from peripheral blood lymphocytes. Weighted and unweighted Cox regressions and linear regression analyses were used to assess whether TL was associated with BRCA1/2 mutation status or cancer risk. We found no evidence for association between developing cancer or being a BRCA1 or BRCA2 mutation carrier and telomere length. It is the first study investigating TL in a cohort of genetically predisposed males and although TL and BRCA status was previously studied in females our results don't support the previous finding of association between hereditary breast cancer and shorter TL

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Targeting A20 Decreases Glioma Stem Cell Survival and Tumor Growth

The A20 protein is a known inhibitor of apoptosis that here is shown to be a novel cancer stem cell-promoting factor associated with poor glioma patient survival

Genome-Wide Association Study of Relative Telomere Length

Telomere function is essential to maintaining the physical integrity of linear chromosomes and healthy human aging. The probability of forming proper telomere structures depends on the length of the telomeric DNA tract. We attempted to identify common genetic variants associated with log relative telomere length using genome-wide genotyping data on 3,554 individuals from the Nurses' Health Study and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial that took part in the National Cancer Institute Cancer Genetic Markers of Susceptibility initiative for breast and prostate cancer. After genotyping 64 independent SNPs selected for replication in additional Nurses' Health Study and Women's Genome Health Study participants, we did not identify genome-wide significant loci; however, we replicated the inverse association of log relative telomere length with the minor allele variant [C] of rs16847897 at the TERC locus (per allele β = −0.03, P = 0.003) identified by a previous genome-wide association study. We did not find evidence for an association with variants at the OBFC1 locus or other loci reported to be associated with telomere length. With this sample size we had >80% power to detect β estimates as small as ±0.10 for SNPs with minor allele frequencies of ≥0.15 at genome-wide significance. However, power is greatly reduced for β estimates smaller than ±0.10, such as those for variants at the TERC locus. In general, common genetic variants associated with telomere length homeostasis have been difficult to detect. Potential biological and technical issues are discussed

Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.

OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis

CSPonD demonstrative project: Start-up process of a 25 kW prototype

© 2017 Author(s). The current concept of commercial concentrated solar power (CSP) plants, based on the concept of a solar field, receiver, storage and power block, experienced significant growth in the past decades. The power block is the most well know part of the plant, while solar field depends on the receiver technology. The dominant receiver technologies are parabolic troughs and central towers. Most thermal energy storage (TES) relies on two tanks of molten salts, one hot and one cold serviced by pumps and piping systems. In spite of the technical development level achieved by these systems, efficiency is limited, mainly caused by thermal losses in piping, parasitic losses due to electric tracing and pumping and receiver limitations. In order to mitigate the these issues, a new concept called Concentrated Solar Power on Demand (CSPonD), was developed, consisting of a direct absorption Solar Salt CSP receiver which simultaneously acts as TES tank. Currently, in the frame of the flagship collaborative project between the Masdar Institute (UAE) and the Massachusetts Institute of Technology (USA) a 25 kW demonstrative prototype is in its final building phase at the Masdar Institute Solar Platform. The present paper, explains the demonstration prototype based on the CSPonD concept, with emphasis on the planned start-up process for the facility

Variants near TERT and TERC influencing telomere length are associated with high-grade glioma risk.

Glioma, the most common central nervous system cancer in adults, has poor prognosis. Here we identify a new SNP associated with glioma risk, rs1920116 (near TERC), that reached genome-wide significance (Pcombined = 8.3 × 10(-9)) in a meta-analysis of genome-wide association studies (GWAS) of high-grade glioma and replication data (1,644 cases and 7,736 controls). This region has previously been associated with mean leukocyte telomere length (LTL). We therefore examined the relationship between LTL and both this new risk locus and other previously established risk loci for glioma using data from a recent GWAS of LTL (n = 37,684 individuals). Alleles associated with glioma risk near TERC and TERT were strongly associated with longer LTL (P = 5.5 × 10(-20) and 4.4 × 10(-19), respectively). In contrast, risk-associated alleles near RTEL1 were inconsistently associated with LTL, suggesting the presence of distinct causal alleles. No other risk loci for glioma were associated with LTL. The identification of risk alleles for glioma near TERC and TERT that also associate with telomere length implicates telomerase in gliomagenesis