Differential cross section for neutron-proton bremsstrahlung

The neutron-proton bremsstrahlung process $(np \to np\gamma)$ is known to be sensitive to meson exchange currents in the nucleon-nucleon interaction. The triply differential cross section for this reaction has been measured for the first time at the Los Alamos Neutron Science Center, using an intense, pulsed beam of up to 700 MeV neutrons to bombard a liquid hydrogen target. Scattered neutrons were observed at six angles between 12$^\circ$ and 32$^\circ$, and the recoil protons were observed in coincidence at 12$^\circ$, 20$^\circ$, and 28$^\circ$ on the opposite side of the beam. Measurement of the neutron and proton energies at known angles allows full kinematic reconstruction of each event. The data are compared with predictions of two theoretical calculations, based on relativistic soft-photon and non-relativistic potential models.Comment: 5 pages, 3 figure

Two‐nucleon processes in pion‐induced double charge exchange in 4He: A coincidence measurement of the 4He(π+,π− p)3p reaction

Inclusive measurements of pion double‐charge‐exchange in 3He[1] and 4He[2] in the Δ(1232) resonance region suggest the dominance of a two‐step sequential single‐charge‐exchange mechanism involving quasi‐free nucleons. To investigate this reaction mechanism, we have observed protons in coincidence with the outgoing pion in π++4He→π−+4p at Tπ+=240 MeV. Pions were detected in a magnetic spectrometer at θπ−=32°, while protons were detected in a close‐packed array of plastic scintillator telescopes covering θp=67.5°–157.5° on the same side of the beam as the spectrometer, and θp=22.5°–157.5° on the opposite side. We will present preliminary results for the distributions in energy and angle of the coincident protons. © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87562/2/542_1.pd

DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.

This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface comprising a release. In July 2003, DOE/SNL presented the spallings conceptual model to a independent peer review panel in accordance with NUREG 1297 guidelines (NRC, 1988). The panel ultimately judged the model as adequate for implementation in WIPP PA (Yew et al., 2003). This report documents the spallings model history from 1997 to the implementation of DRSPALL in the 2004 Compliance Recertification Application (CRA) (DOE, 2004). The scope of this report includes descriptions of the conceptual model, numerical model, verification and validation techniques, model sensitivity studies, and WIPP PA spallings results as presented in the 2004 CRA

The effect of age and unilateral leg immobilisation for 2 weeks on substrate ulilisation during moderate-intensity exercise in human skeletal muscle

Age and inactivity have been associated with intramuscular triglyceride (IMTG) accumulation. Here, we attempt to disentangle these factors by studying the effect of 2 weeks of unilateral leg immobilization on substrate utilization across the legs during moderate-intensity exercise in young (n = 17; 23 ± 1 years old) and older men (n = 15; 68 ± 1 years old), while the contralateral leg served as the control. After immobilization, the participants performed two-legged isolated knee-extensor exercise at 20±1W(_50% maximalwork capacity) for 45 min with catheters inserted in the brachial artery and both femoral veins.Biopsy samples obtained from vastus lateralis muscles of both legs before and after exercise were used for analysis of substrates, protein content and enzyme activities. During exercise, leg substrate utilization (respiratoryquotient) did not differ between groups or legs. Leg fatty acid uptake was greater in older than in young men, and although young men demonstrated net leg glycerol release during exercise, older men showed net glycerol uptake. At baseline, IMTG, muscle pyruvate dehydrogenase complex activity and the protein content of adipose triglyceride lipase, acetyl-CoA carboxylase 2 and AMP-activated protein kinase (AMPK)γ3 were higher in young than in older men. Furthermore, adipose triglyceride lipase, plasma membrane-associated fatty acid binding protein and AMPKγ3 subunit protein contents were lower and IMTG was higher in the immobilized than the contralateral leg in young and older men. Thus, immobilization and age did not affect substrate choice (respiratory quotient) during moderate exercise, but the whole-leg and molecular differences in fatty acid mobilization could explain the age- and immobilization-induced IMTG accumulation

Dose-dependent improvement of myoclonic hyperkinesia due to Valproic acid in eight Huntington's Disease patients: a case series

BACKGROUND: Chorea in Huntington's Disease (HD) is usually treated with antidopaminergic neuroleptics like haloperidol, olanzapine and tiaprid or dopamine depleting drugs like tetrabenazine. Some patients with hyperkinesia, however, react to treatment with antidopaminergic drugs by developing extrapyramidal side effects. In earlier studies valproic acid showed no beneficial effect on involuntary choreatic movements. Myoclonus is rare in HD and is often overseen or misdiagnosed as chorea. METHODS: In this report, we present eight patients whose main symptom is myoclonic hyperkinesia. All patients were treated with valproic acid and scored by using the Unified Huntington's Disease Rating Scale (UHDRS) motor score before and after treatment. In addition to this, two patients agreed to be videotaped. RESULTS: In seven patients myoclonus and, therefore the UHDRS motor score improved in a dose dependent manner. In three of these patients antidopaminergic medication could be reduced. CONCLUSION: In the rare subgroup of HD patients suffering from myoclonic hyperkinesia, valproic acid is a possible alternative treatment

Reproductive and hormone-related risk factors for epithelial ovarian cancer by histologic pathways, invasiveness and histologic subtypes: results from the EPIC cohort

Whether risk factors for epithelial ovarian cancer (EOC) differ by subtype (i.e., dualistic pathway of carcinogenesis, histologic subtype) is not well understood; however, data to date suggest risk factor differences. We examined associations between reproductive and hormone-related risk factors for EOC by subtype in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Among 334,126 women with data on reproductive and hormone-related risk factors (follow-up: 1992–2010), 1,245 incident cases of EOC with known histology and invasiveness were identified. Data on tumor histology, grade, and invasiveness, were available from cancer registries and pathology record review. We observed significant heterogeneity by the dualistic model (i.e., type I [low grade serous or endometrioid, mucinous, clear cell, malignant Brenner] vs. type II [high grade serous or endometrioid]) for full-term pregnancy (phet = 0.02). Full-term pregnancy was more strongly inversely associated with type I than type II tumors (ever vs. never: type I: relative risk (RR) 0.47 [95% confidence interval (CI): 0.33–0.69]; type II, RR: 0.81 [0.61–1.06]). We observed no significant differences in risk in analyses by major histologic subtypes of invasive EOC (serous, mucinous, endometrioid, clear cell). None of the investigated factors were associated with borderline tumors. Established protective factors, including duration of oral contraceptive use and full term pregnancy, were consistently inversely associated with risk across histologic subtypes (e.g., ever full-term pregnancy: serous, RR: 0.73 [0.58–0.92]; mucinous, RR: 0.53 [0.30–0.95]; endometrioid, RR: 0.65 [0.40–1.06]; clear cell, RR: 0.34 [0.18–0.64]; phet = 0.16). These results suggest limited heterogeneity between reproductive and hormone-related risk factors and EOC subtypes

Substance-Related Health Problems during Rave Parties in the Netherlands (1997–2008)

The objective of this study was to describe a 12-year (1997–2008) observation of substance-related incidents occurring at rave parties in the Netherlands, including length of visits to first-aid stations, substances used, and severity of the incidents. During rave parties, specifically trained medical and paramedical personnel staffed first aid stations. Visitors were diagnosed and treated, and their data were recorded using standardized methods. During the 12-year period with 249 rave parties involving about 3,800,000 visitors, 27,897 people visited a first aid station, of whom 10,100 reported having a substance-related problem. The mean age of these people was 22.3+/−5.4 years; 52.4% of them were male. Most (66.7%) substance-related problems were associated with ecstasy or alcohol use or both. Among 10,100 substance-related cases, 515 required professional medical care, and 16 of these cases were life threatening. People with a substance-related problem stayed 20 min at the first aid station, which was significantly longer than the 5 min that those without a substance-related health problem stayed. These unique data from the Netherlands identify a variety of acute health problems related to the use of alcohol, amphetamines, cannabis, cocaine, ecstasy, and GHB. Although most problems were minor, people using GHB more often required professional medical care those using the other substances. We recommended adherence to harm and risk reduction policy, and the use of first aid stations with specially trained staff for both minor and serious incidents

Endogenous sex steroids and risk of cervical carcinoma : results from the EPIC study

Background: Epidemiologic data and animal models suggest that, despite the predominant role of human papillomavirus infection, sex steroid hormones are also involved in the etiology of invasive cervical carcinoma (ICC). Methods: Ninety-nine ICC cases, 121 cervical intraepithelial neoplasia grade 3 (CIN3) cases and 2 control women matched with each case for center, age, menopausal status and blood collection-related variables, were identified in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Circulating levels of testosterone (T) and estradiol (E(2)); dehydroepiandrosterone sulfate (DHEAS); progesterone (premenopausal women); and sex hormone-binding globulin (SHBG) were measured using immunoassays. Levels of free (f) T and E(2) were calculated from absolute concentrations of T, E(2), and SHBG. Odds ratios (ORs) and 95% confidence intervals (CI) were computed using regularized conditional logistic regression. Results: Among premenopausal women, associations with ICC were observed for fT (OR for highest vs. lowest tertile 5.16, 95% CI, 1.50-20.1). SHBG level was associated with a significant downward trend in ICC risk. T, E(2), fE(2), and DHEAS showed nonsignificant positive association with ICC. Progesterone was uninfluential. Among postmenopausal women, associations with ICC were found for T (OR 3.14; 95% CI, 1.21-9.37), whereas E(2) and fT showed nonsignificant positive association. SHBG level was unrelated to ICC risk in postmenopausal women. No associations between any hormone and CIN3 were detected in either pre- or postmenopausal women. Conclusions: Our findings suggest for the first time that T and possibly E(2) may be involved in the etiology of ICC. Impact: The responsiveness of cervical tumors to hormone modulators is worth exploring. Cancer Epidemiol Biomarkers Prev; 20(12); 2532-40. (C) 2011 AACR

A Versatile System for USER Cloning-Based Assembly of Expression Vectors for Mammalian Cell Engineering

A new versatile mammalian vector system for protein production, cell biology analyses, and cell factory engineering was developed. The vector system applies the ligation-free uracil-excision based technique--USER cloning--to rapidly construct mammalian expression vectors of multiple DNA fragments and with maximum flexibility, both for choice of vector backbone and cargo. The vector system includes a set of basic vectors and a toolbox containing a multitude of DNA building blocks including promoters, terminators, selectable marker- and reporter genes, and sequences encoding an internal ribosome entry site, cellular localization signals and epitope- and purification tags. Building blocks in the toolbox can be easily combined as they contain defined and tested Flexible Assembly Sequence Tags, FASTs. USER cloning with FASTs allows rapid swaps of gene, promoter or selection marker in existing plasmids and simple construction of vectors encoding proteins, which are fused to fluorescence-, purification-, localization-, or epitope tags. The mammalian expression vector assembly platform currently allows for the assembly of up to seven fragments in a single cloning step with correct directionality and with a cloning efficiency above 90%. The functionality of basic vectors for FAST assembly was tested and validated by transient expression of fluorescent model proteins in CHO, U-2-OS and HEK293 cell lines. In this test, we included many of the most common vector elements for heterologous gene expression in mammalian cells, in addition the system is fully extendable by other users. The vector system is designed to facilitate high-throughput genome-scale studies of mammalian cells, such as the newly sequenced CHO cell lines, through the ability to rapidly generate high-fidelity assembly of customizable gene expression vectors