Patient-specific stopping power calibration for proton therapy planning based on single-detector proton radiography.

A simple robust optimizer has been developed that can produce patient-specific calibration curves to convert x-ray computed tomography (CT) numbers to relative stopping powers (HU-RSPs) for proton therapy treatment planning. The difference between a digitally reconstructed radiograph water-equivalent path length (DRRWEPL) map through the x-ray CT dataset and a proton radiograph (set as the ground truth) is minimized by optimizing the HU-RSP calibration curve. The function of the optimizer is validated with synthetic datasets that contain no noise and its robustness is shown against CT noise. Application of the procedure is then demonstrated on a plastic and a real tissue phantom, with proton radiographs produced using a single detector. The mean errors using generic/optimized calibration curves between the DRRWEPL map and the proton radiograph were 1.8/0.4% for a plastic phantom and -2.1/ - 0.2% for a real tissue phantom. It was then demonstrated that these optimized calibration curves offer a better prediction of the water equivalent path length at a therapeutic depth. We believe that these promising results are suggestive that a single proton radiograph could be used to generate a patient-specific calibration curve as part of the current proton treatment planning workflow

Particle swarm optimization for bi-level pricing problems in supply chains

With rapid technological innovation and strong competition in hi-tech industries such as computer and communication organizations, the upstream component price and the downstream product cost usually decline significantly with time. As a result, an effective pricing supply chain model is very important. This paper first establishes two bi-level pricing models for pricing problems with the buyer and the vendor in a supply chain designated as the leader and the follower, respectively. A particle swarm optimization (PSO) based algorithm is developed to solve problems defined by these bi-level pricing models. Experiments illustrate that this PSO based algorithm can achieve a profit increase for buyers or vendors if they are treated as the leaders under some situations, compared with the existing methods. © 2010 Springer Science+Business Media, LLC

Heavy metal pollution in benthic fishes from Kiri Dam in Guyuk local government area of Adamawa State, Nigeria

Heavy metal concentrations in lungfish (Polypterus annectens), African carp (Heterotis niloticus) and catfish (Clarotes laticeps) in Kiri Dam in the Guyuk local government area, Adamawa State, Nigeria were studied. The concentrations of lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), nickel (Ni) and iron (Fe) were determined. These metals concentrations were measured by inductively coupled plasma-optical emission spectrometry (ICP-OES) in order to assess the fish contamination with these metals. The gills, muscles, bones and  intestines were analysed for each heavy metal. This research shows that catfish had the highest heavy metals  concentrations. Catfish Pb concentrations were 0.832, 0.480, 0.661 and 0.810 mg/L in the gills, muscles,  bones and intestine, respectively. The gills accumulated the highest level of these metals in C. laticeps  compared to the other species. Lungfish and African carp had higher concentrations of Cd in the examined parts of their bodies. Based on the results, it is apparent that the metal levels in all the fish species were below the recommended concentrations for human consumption, indicating that the study area is relatively less polluted with heavy metals.Key words: Heavy metals, pollution, fishes, Kiri Dam, Nigeria

Experimental Measurement of the Berry Curvature from Anomalous Transport

Geometrical properties of energy bands underlie fascinating phenomena in a wide-range of systems, including solid-state materials, ultracold gases and photonics. Most famously, local geometrical characteristics like the Berry curvature can be related to global topological invariants such as those classifying quantum Hall states or topological insulators. Regardless of the band topology, however, any non-zero Berry curvature can have important consequences, such as in the semi-classical evolution of a wave packet. Here, we experimentally demonstrate for the first time that wave packet dynamics can be used to directly map out the Berry curvature. To this end, we use optical pulses in two coupled fibre loops to study the discrete time-evolution of a wave packet in a 1D geometrical "charge" pump, where the Berry curvature leads to an anomalous displacement of the wave packet under pumping. This is both the first direct observation of Berry curvature effects in an optical system, and, more generally, the proof-of-principle demonstration that semi-classical dynamics can serve as a high-resolution tool for mapping out geometrical properties

The rising cost of hospital care for children with gastroparesis: 2004-2013.

BackgroundThe cost of hospital care for adults with gastroparesis (GP) is increasing. Our objective was to evaluate the cost of hospital care for children with GP.MethodsUsing the Pediatric Health Information System, we selected hospitalizations with a diagnosis of GP (ICD-9 536.3), dyspepsia and other specified disorders of function of stomach (DYS, 536.8) and unspecified functional disorder of stomach (UFD, 536.9) from 2004 to 2013. We recorded dates of hospitalization, demographics, costs, and length of stay (LOS).Key resultsFrom 2004 to 2013, 4015 patients were admitted for GP (54.2% female, median age 8 years). Total cost of hospitalization for GP increased 5.8 fold from $6 185 390 to$35 654 075 (p = 0.0001). Cost per hospitalization did not change. Cost of initial hospitalization was highest in patients 0-5 years and lowest in patients 16-21 years (p < 0.0001). Number of hospitalizations each year for GP increased from 252 to 1310 (p < 0.0001) and unique patients hospitalized increased from 174 to 723 (p < 0.0001). Number of hospitalizations and unique patients for DYS/UFD also increased (p < 0.0001). LOS for GP did not change with time. Females and younger GP patients had more repeat hospitalizations (p < 0.0001, p < 0.0001).Conclusions & inferencesThe financial burden of hospitalization for pediatric GP has increased dramatically from 2004 to 2013, driven by a rise in number of hospitalizations and unique patients hospitalized each year. Cost and LOS per hospitalization remain stable. Unlike in adults, hospitalizations for DYS/UFD have also increased, suggesting that the increase in hospitalizations for GP is not secondary to changing diagnostic practices

Assessment of Cellular Estrogenic Activity Based on Estrogen Receptor-Mediated Reduction of Soluble-Form Catechol-O-Methyltransferase (COMT) Expression in an ELISA-Based System

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Isolation and expression of the human gametocyte-specific factor 1 gene (GTSF1) in fetal ovary, oocytes, and preimplantation embryos

Purpose: Gametocyte-specific factor 1 has been shown in other species to be required for the silencing of retrotransposons via the Piwi-interacting RNA (piRNA) pathway. In this study, we aimed to isolate and assess expression of transcripts of the gametocyte-specific factor 1 (GTSF1) gene in the human female germline and in preimplantation embryos. Methods: Complementary DNA (cDNA) libraries from human fetal ovaries and testes, human oocytes and preimplantation embryos and ovarian follicles isolated from an adult ovarian cortex biopsy were used to as templates for PCR, cloning and sequencing, and real time PCR experiments of GTSF1 expression. Results: GTSF1 cDNA clones that covered the entire coding region were isolated from human oocytes and preimplantation embryos. GTSF1 mRNA expression was detected in archived cDNAs from staged human ovarian follicles, germinal vesicle (GV) stage oocytes, metaphase II oocytes, and morula and blastocyst stage preimplantation embryos. Within the adult female germline, expression was highest in GV oocytes. GTSF1 mRNA expression was also assessed in human fetal ovary and was observed to increase during gestation, from 8 to 21 weeks, during which time oogonia enter meiosis and primordial follicle formation first occurs. In human fetal testis, GTSF1 expression also increased from 8 to 19 weeks. Conclusions: To our knowledge, this report is the first to describe the expression of the human GTSF1 gene in human gametes and preimplantation embryos

The effect of ex-vivo rotenone intoxication on dopamine re-uptake of LRRK2-R1441G mutant mouse

Poster presentationpublished_or_final_versio

Exploring 4D Quantum Hall Physics with a 2D Topological Charge Pump

The discovery of topological states of matter has profoundly augmented our understanding of phase transitions in physical systems. Instead of local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example thereof is the two-dimensional integer quantum Hall effect. It is characterized by the first Chern number which manifests in the quantized Hall response induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional systems leads to the appearance of a novel non-linear Hall response that is quantized as well, but described by a 4D topological invariant - the second Chern number. Here, we report on the first observation of a bulk response with intrinsic 4D topology and the measurement of the associated second Chern number. By implementing a 2D topological charge pump with ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small atom cloud as a local probe, we fully characterize the non-linear response of the system by in-situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probe higher-dimensional quantum Hall systems, where new topological phases with exotic excitations are predicted