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We report on a detailed study of longitudinal strength in the nucleon resonance region, presenting new results from inclusive electron-proton cross sections measured at Jefferson Lab Hall C in the four-momentum transfer range 0.2

The goal of this study was to characterize sperm populations resulting from three different methods of sperm selection used for bovine in vitro fertilization. We compared sperm selection with discontinuous Percoll gradients, Swim-Up, and electro-channel. Spatial light interference microscopy (SLIM) was used to evaluate the morphology of the spermatozoa and computer-assisted semen analysis (CASA) was used to evaluate the motility behavior of the sperm. Using these two technologies, we analyzed morphometric parameters and the kinetic (motility) patterns of frozen-thawed Holstein bull spermatozoa after sperm selection. For the first time, we have shown that these methods used to select viable spermatozoa for in vitro fertilization (IVF) result in very different sperm subpopulations. Almost every parameter evaluated resulted in statistical differences between treatment groups. One novel observation was that the dry mass of the sperm head is heavier in spermatozoa selected with the electro-channel than in sperm selected by the other methods. These results show the potential of SLIM microscopy in reproductive biology. Abbreviations: SLIM: spatial light interference microscopy; CASA: computer aided sperm analysis; IVF: in vitro fertilization; BSA: bovine serum albumin; QPI: quantitative phase imaging; IVEP: in vitro embryo production; IACUC: institutional animal care and use committee; CSS: Certified Semen Services; AI: artificial insemination; TALP: Tyrode's Albumin Lactate Pyruvate; MEC: medium for electro-channel; PDMS: polydimethylsiloxane; EC: electro-channel; TM, %: total motility; PM, %: progressive motility; RM, %: percentage of rapid sperm motility; VAP, μm/s: average path velocity; VSL, μm/s: straight-line velocity; VCL, μm/s: curvilinear velocity; ALH, μm: amplitude of lateral head displacement; BCF, Hz: beat cross frequency; STR, %: straightness; LIN, %: and linearity; GLS: generalized least squares; ANOVA: analysis of variance; LSD: Least Significant Difference; SPSS: Statistical Package for the Social Sciences; PCA: principal components analysis.

The observation of neutron stars with masses greater than one solar mass places severe demands on any exotic neutron decay mode that could explain the discrepancy between beam and bottle measurements of the neutron lifetime. If the neutron can decay to a stable, feebly interacting dark fermion, the maximum possible mass of a neutron star is 0.7M_{⊙}, while all well-measured neutron star masses exceed one M_{⊙}. The existence of 2M_{⊙} neutron stars further indicates that any explanation beyond the standard model for the neutron lifetime puzzle requires dark matter to be part of a multiparticle dark sector with highly constrained interactions. Beyond the neutron lifetime puzzle, our results indicate that neutron stars provide unique and useful probes of GeV-scale dark sectors coupled to the standard model via baryon-number-violating interactions.

The neutron, in addition to possibly having a permanent electric dipole moment as a consequence of violation of time-reversal invariance, develops an induced electric dipole moment in the presence of an external electric field. We present here a unified nonrelativistic description of these two phenomena, in which the dipole moment operator, [Formula: see text], is not constrained to lie along the spin operator. Although the expectation value of [Formula: see text] in the neutron is less than [Formula: see text] of the neutron radius, [Formula: see text], the expectation value of [Formula: see text] is of order [Formula: see text] We determine the spin motion in external electric and magnetic fields, as used in past and future searches for a permanent dipole moment, and show that the neutron electric polarizability, although entering the neutron energy in an external electric field, does not affect the spin motion. In a simple nonrelativistic model we show that the expectation value of the permanent dipole is, to lowest order, proportional to the product of the time-reversal-violating coupling strength and the electric polarizability of the neutron.

We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ∼600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1-2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures at 0.4 K. We also measured the current between two electrodes. Our initial results, I < 1 pA at 45 kV, correspond to a lower bound on the effective volume resistivity of liquid helium of ρV > 5 × 10(18) Ω cm. This lower bound is 5 times larger than the bound previously measured. We report the design, construction, and operational experience of the apparatus, as well as initial results.

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2  ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03  ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasielastic scattering on the deuteron, at backward angles (lab scattering angle of 108°) for Q² = 0.22 GeV²/c² and 0.63 GeV²/c² at beam energies of 362 and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single-photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (πN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasistatic deuterium approximation, and is also in agreement with theory.

We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2=0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of approximately < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial-vector current at these four-momentum transfers.

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2=0.15, 0.25 (GeV/c)2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A(n) provides a direct probe of the imaginary component of the 2gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 < or =1.0 GeV2. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange-quark contributions to the currents of the proton. The measurements were made at Jefferson Laboratory using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate nonzero, Q2 dependent, strange-quark contributions and provide new information beyond that obtained in previous experiments.

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2=0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51+/-0.57 (stat)+/-0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2=0.091 (GeV/c)2, which are also consistent with theoretical predictions.

Objective: External validation of three prognostic models in adult intensive care patients in South England. DESIGN. Prospective cohort study., Setting: Seventeen intensive care units (ICU) in the South West Thames Region in South England., Patients and Participants: Data of 16646 patients were analysed., Interventions: None., Measurements and Results: We compared directly the predictive accuracy of three prognostic models (SAPS II, APACHE II and III), using formal tests of calibration and discrimination. The external validation showed a similar pattern for all three models tested: good discrimination, but imperfect calibration. The areas under the receiver operating characteristics (ROC) curves, used to test discrimination, were 0.835 and 0.867 for APACHE II and III, and 0.852 for the SAPS II model. Model calibration was assessed by Lemeshow-Hosmer C-statistics and was Chi(2 )=232.1 for APACHE II, Chi(2 )=443.3 for APACHE III and Chi(2 )=287.5 for SAPS II., Conclusions: Disparity in case mix, a higher prevalence of outcome events and important unmeasured patient mix factors are possible sources for the decay of the models' predictive accuracy in our population. The lack of generalisability of standard prognostic models requires their validation and re-calibration before they can be applied with confidence to new populations. Customisation of existing models may become an important strategy to obtain authentic information on disease severity, which is a prerequisite for reliably measuring and comparing the quality and cost of intensive care.

Objective: To assess the effects of discharge Therapeutic Intervention Scoring System (TISS) scores, discharge time and type of discharge facility on ultimate hospital mortality after intensive care., Design: Retrospective cohort study., Setting: General intensive care unit (ICU) in a district general hospital., Patients and Participants: One thousand six hundred fifty-four ICU patients discharged to hospital wards or high dependency units (HDUs)., Main Measurements and Results: Vital status at ultimate hospital discharge was the main outcome measurement. The crude hospital mortality after ICU discharge (12.6%) was significantly associated with increasing discharge TISS scores (chi(2) for trend =9.0, p=0.028). This trend was similarly observed after adjusting for severity of disease. Patients with high TISS scores (>30) who were discharged to hospital wards had a higher risk (1.31; CI: 1.02-1.83) of in-hospital death compared with patients discharged to HDUs. Crude mortality was significantly higher for late 20.00 h to 7.59 h) than for early (8.00 h to 19.59 h) discharges (18.8% versus 11.2%, chi(2) =12.1, p=0.0004). Adjusted for disease severity, the mortality risk was 1.70-fold (CI: 1.28-2.25) increased for late ICU discharges. Patients discharged late to hospital wards had significantly higher severity-adjusted risks (1.87; CI:1.36-2.56) than had patients discharged to HDUs (1.35; CI: 0.77-2.36)., Conclusions: Both late discharge and high discharge TISS scores are indicators of "premature" ICU discharge and were associated with increased mortality. Intermediate care reduced the mortality of patients discharged "prematurely" from ICU. This adds to the growing evidence of the benefits of intermediate care after ICU discharge.

Model customisation is used to adjust prognostic models by re-calibrating them to obtain more reliable mortality estimates. We used two methods for customising the Simplified Acute Physiology Score II model for 15,511 intensive care patients by altering the logit and the coefficients of the original equation. Both methods significantly improved model calibration, but customising the coefficients was slightly more effective. The Hosmer-Lemeshow chi(2)-value improved from 306.0 (p< 0.001) before, to 14.5 (p < 0.07) and 23.3 (p < 0.06) after customisation of the coefficients and the logit, respectively. Discrimination was not affected. The standardised mortality ratio for the entire population declined from 1.16 (95% confidence interval: 1.13-1.20, p < 0.001) to 0.99 (95% confidence interval: 0.96-1.02, p < 0.22) after customisation of the coefficients. The uniformity-of-fit for patients grouped by operative status and comorbidities also improved, but remained imperfect for patients stratified by location before intensive care unit admission. Amalgamation of large, regional databases could provide the basis for the re-calibration of standard prognostic models, which could then be used as a national reference system to allow more reliable comparisons of the efficacy and quality of care based on severity adjusted outcome measures.

A large proportion of intensive care unit patients are low-risk admissions. Mortality probabilities generated by predictive systems may not accurately reflect the mortality experienced by subpopulations of critically ill patients. We prospectively assessed the impact of low-risk admissions (mortality risk < 10%) on the mortality estimates generated by three prognostic models. We studied 1497 consecutive admissions to a general intensive care unit. The performance of the three models for subgroups and the whole population was analysed. The proportions of patients designated as low risk varied with the model and differences in model performance were most pronounced for these patients. The APACHE II mortality ratios (1.32 vs. 1.19) did not differ for low- and higher risk patients, but mortality ratios generated by APACHE III (2.38 vs. 1.23) and SAPS II (2.19 vs. 1.16) were nearly two-fold greater. Calibration for higher risk patients was similar for all three models but the APACHE III system calibrated worse than the other models for low-risk patients. This may have contributed to the poorer overall calibration of the APACHE III system (Hosmer-Lemeshow C-test: APACHE III chi(2) = 329; APACHE II chi(2) = 42; SAPS II chi(2) = 62). Imperfect characterisation of the large proportion of low-risk intensive care unit admissions may contribute to the deterioration of the models' predictive accuracies for the intensive care population as a whole.

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.

Background and Objective: Efficacy and side-effects of piritramide (pirinitramide) and morphine, given intravenously for postoperative analgesia after hysterectomy, were compared in a randomized controlled double-blind trial in 92 ASA class I-III patients., Methods: Administration was investigator-controlled during the first 90 min and subsequently via a patient-controlled device. Visual analogue scales for pain intensity and verbal rating scales for side-effects were taken repeatedly., Results: Median visual analogue scores for pain intensity on a 100-mm scale 4, 8 and 24 h after surgery were 10, 8.5 and 5 mm in the piritramide group and 18, 10 and 8.5 mm in the morphine group. These differences are neither statistically nor clinically significant. Median values for nausea on a verbal rating scale from 0 to 3 were zero for both groups at all times with similar ranges. There was no difference in number of episodes of vomiting and retching and usage of antiemetics. The mean amount of piritramide used for initial titration was 15.2 mg; the respective amount of morphine was 15.4 mg., Conclusions: In this setting the two agents are equally effective and show a similar profile of side-effects.

Forty patients requiring one-lung ventilation (OLV) for thoracic surgery were randomly assigned to receive propofol (4-6 mg kg(-1) h(-1)) or sevoflurane (1 MAC) for maintenance of anaesthesia. Three sets of measurements were taken: (i) after 30 min of two-lung ventilation (TLV), (ii) after 30 min of one-lung ventilation (OLV-1) in the supine position and (iii) during OLV in the lateral position (OLV-2) with the chest open and before surgical manipulation of the lung. There were no differences between groups in patient characteristics or preoperative condition. Increases in shunt fraction during OLV-1 were 17.4% and 17.2% (P=0.94), those during OLV-2 were 18.3% and 16.5% (P=0.59) for the propofol and sevoflurane group, respectively. Cardiac index and other haemodynamic and respiratory variables were similar for the two groups. We conclude that inhibition of hypoxic pulmonary vasoconstriction by sevoflurane may only account for small increases in shunt fraction and that much of the overall shunt fraction during OLV has other causes.

The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

A newly obtained sample of inclusive electron-nucleon scattering data has been analyzed for precision tests of quark-hadron duality. The data are in the nucleon resonance region, and span the range 0. 3

A newly obtained data sample of inclusive electron-nucleon scattering from both hydrogen and deuterium targets is analyzed. These JLab data span the nucleon resonance region up to four-momentum transfers of 5 (GeV/c)(2). The data are found to follow an average scaling curve. The inclusion of low-momentum transfer data yields a scaling curve resembling deep inelastic neutrino-nucleus scattering data, suggesting a sensitivity to valencelike structure only.

We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A = -4.92+/-0.61+/-0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections.

Unlabelled: Analgesic acetaminophen plasma concentrations are not known. We investigated in a randomized, double-blinded study the pharmacokinetics and analgesic efficacy of small- (AS; 20 mg. kg(-1)) and larger- (AL; 40 mg/kg) dose rectal acetaminophen and compared it with the combination (C) of rectal diclofenac (100 mg) and acetaminophen (20 mg/kg) in 65 women undergoing hysterectomy. Suppositories were administered after the induction of a standardized general anesthesia. Pain (measured by using a 10-cm visual analog scale) and morphine consumption (patient-controlled analgesia) were repeatedly assessed for 24 h. Acetaminophen plasma concentrations were measured by using a fluorescence polarization immunoassay. Antipyretic plasma concentrations (10-20 mg/L) after 40 mg/kg acetaminophen were not associated with improved analgesia or decreased opioid requirements; 20 mg/kg acetaminophen produced subtherapeutic plasma levels (<10 mg/L). Maximal plasma concentrations of 17.2 and 10.4 mg/L (P < 0.01, analysis of variance) were achieved after 4.2 and 3.6 h for the AL and AS groups, respectively. The only difference in clinical outcome was lower visual analog scale scores after acetaminophen/diclofenac (C 2.0 versus AS 3.2 and AL 3.4) 4 h after the induction (P < 0.05, analysis of variance). Acetaminophen pharmacokinetics in adults were similar to those observed in children. Analgesic plasma concentrations are likely to be higher than antipyretic plasma levels, which were only attained after twice the recommended rectal dose was administered. Analgesic plasma concentrations have yet to be determined but may be higher than those associated with antipyresis., Implications: Acetaminophen pharmacokinetics were comparable in adults and children. Plasma concentrations known to reduce fever did not produce better pain relief and were only achieved after twice the conventional dose was administered. Analgesic plasma concentrations have yet to be determined but may be higher than those associated with antipyresis.

Objective: To evaluate the ability of two prognostic systems to predict hospital mortality in adult intensive care patients., Design: Prospective cohort study., Setting: A mixed medical and surgical intensive care unit (ICU) in the United Kingdom., Patients: A total of 1,144 patients consecutively admitted to the study., Interventions: None., Measurements and Main Results: Acute Physiology and Chronic Health Evaluation (APACHE) II and III prognostic systems were applied to assess probabilities of hospital mortality, which were compared with the actual outcome. The overall goodness-of-fit of both models was assessed. Hospital death rates were higher than those predicted by each system. Risk estimates showed a strong positive correlation between both systems (nonsurvivors r2 = 0.756, p < .0001; survivors r2 = 0.787, p < .0001). Calibration of APACHE II (chi 2 = 98.6, Lemeshow-Hosmer) was superior to that of APACHE III (chi 2 = 129.8, Lemeshow-Hosmer). The total correct classification rate of APACHE III was greater for all decision criteria applied; the best overall total correct classification rate was 80.6% for APACHE III and 77.9% for APACHE II (both for a decision criterion of 40%). The areas under the receiver operating characteristic curves were 0.806 and 0.847 for APACHE II and III, respectively, confirming the better discrimination of APACHE III. When patients were classified by diagnostic categories, risk predictions did not fit uniformly across the spectrum of disease groups. For both models, mortality ratios were highest for trauma patients and lowest for the group with respiratory disease. APACHE II predictions for patients with gastrointestinal disease were significantly better. Risk estimates for surgical admissions were superior with APACHE II (MR = 1.27) compared with APACHE III (MR = 1.56), but were similar for medical patients (1.22 vs. 1.28 for APACHE II and III, respectively). Bias induced by factors reflecting the clinical practice in an individual ICU (e.g., admission criteria, treatment before admission) may have considerable impact on risk estimates. The identification of such factors appears to be a prerequisite for the meaningful interpretation of observed and predicted death rates on the individual ICU level., Conclusions: Both predictive models demonstrated a similar degree of overall goodness-of-fit. APACHE II showed better calibration, but discrimination was better with APACHE III. Hospital mortality was higher than predicted by both models, but was underestimated to a greater degree by APACHE III. Risk estimates by both models showed considerable variation across the disease spectrum of ICU patients. Risk predictions for surgical patients and patients with gastrointestinal disease were better with APACHE II. Factors reflecting the clinical practice of an individual ICU are not accounted for by APACHE II and III. Overall, the performance of APACHE III was not superior to that of its predecessor for a cohort of United Kingdom ICU patients; for certain diagnostic categories, APACHE III performed worse than APACHE II despite an improved system of disease classification.

Massive ascites, hydrothorax, acute renal failure and thromboembolism are clinical manifestations of severe ovarian hyperstimulation syndrome (OHSS) which may complicate the induction of ovulation with exogenous gonadotrophins. We report a case of severe OHSS with ascites formation in excess of five litres per day. Massive ascites and bilateral pleural effusions resulted in respiratory failure. Continuous ascitic recirculation (AR) was commenced after repeated paracentesis and i.v. fluid therapy failed to improve the patient's condition. The procedure was undertaken for a total of 15 days and rapidly resulted in marked improvement of impaired respiratory function. Febrile episodes occurred on 3 occasions, but we did not observe coagulation disturbances or adverse haemodynamic effects. Continuous AR is a safe and effective treatment of complicated severe OHSS.

We report a case of compartment syndrome complicating malignant hyperthermia (MH) in a 12-yr-old girl with a history of myopathy and multiple skeletal deformities; she underwent bilateral Achilles tendon surgery. Marked oedema of both forearms became evident in the immediate postoperative period and resolved after conservative treatment. Compartment syndrome is a rare complication of MH. Early recognition and therapy may prevent the onset of muscle ischaemia and distal neurovascular deficit. The need for urgent surgery and repeated anaesthesia in the early phase of recovery from an acute episode of MH may thus be reduced.

We report a case of fatal carbon dioxide embolism and severe haemorrhage during laparoscopic salpingectomy. A sudden decrease in end-tidal carbon dioxide concentration occurred after 1 h of operating time which, together with the clinical signs, suggested carbon dioxide embolism. Haemorrhage after pelvic venous injury was first noted after deflation of the pneumoperitoneum and resulted in potentiation of the adverse haemodynamic effects of massive gas embolism. Minimally invasive surgery involves more extensive tissue trauma and an increased duration of pneumoperitoneum compared with diagnostic laparoscopy and may increase the risk of serious complications.