First measurement of the spectral function at high energy and momentum in medium-heavy nuclei

The experiment E97-006 was performed at Jefferson Lab to measure the momentum and energy distribution of protons in the nucleus far from the region of the (approximate) validity of the mean field description, i.e. at high momentum and energies. The occurrence of this strength is long known from occupation numbers less than one. In the experiment reported here this strength was directly measured for the first time. The results are compared to modern many-body theories. Further the transparency factor of C12 was determined in the Q^2-region of 0.6 to 1.8 (GeV/c)^2.Comment: Proceeding for Fourth International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region 26.-29. Sept. 2005, Okayam

Electromagnetic proton-neutron knockout off 16O: new achievements in theory

Results for the cross sections of the exclusive 16O(e,e'pn)14N and 16O(gamma,pn)14N knockout reactions are presented and discussed in different kinematics. In comparison with earlier work, a complete treatment of the center-of-mass (CM) effects in the nuclear one-body current is considered in connection with the problem of the lack of orthogonality between initial bound and final scattering states. The effects due to CM and orthogonalization are investigated in combination with different treatments of correlations in the two-nucleon overlap function and for different parametrizations of the two-body currents. The CM effects lead in super-parallel kinematics to a dramatic increase of the 16O(e,e'pn) cross section to the 1_2^+ excited state (3.95 MeV) of 14N. In all the situations considered the results are very sensitive to the treatment of correlations. A crucial role is played by tensor correlations, but also the contribution of long-range correlations is important.Comment: 13 pages, 10 figure

Sequential learning of psychomotor and visuospatial skills for laparoscopic suturing and knot tying – study protocol for a randomized controlled trial “The shoebox study”

Background: Laparoscopy training has become an integral part of surgical education. Suturing and knot tying is a basic, yet inherent part of many laparoscopic operations, and should be mastered prior to operating on patients. One common and standardized suturing technique is the C-loop technique. In the standard training setting, on a box trainer, the trainee learns the psychomotor movements of the task and the laparoscopic visuospatial orientation simultaneously. Learning the psychomotor and visuospatial skills separately and sequentially may offer a more time-efficient alternative to the current standard of training. Methods: This is a monocentric, two-arm randomized controlled trial. The participants are medical students in their clinical years (third to sixth year) at Heidelberg University who have not previously partaken in a laparoscopic training course lasting more than 2 hours. A total of 54 students are randomized into one of two arms in a 1:1 ratio to sequential learning (group 1) or control (group 2). Both groups receive a standardized introduction to the training center, laparoscopic instruments, and C-loop technique. Group 1 learn the C-loop using a transparent shoebox, thus only learning the psychomotor skills. Once they reach proficiency, they then perform the same knot tying procedure on a box trainer with standard laparoscopic view, where they combine their psychomotor skills with the visuospatial orientation inherent to laparoscopy. Group 2 learn the C-loop using solely a box trainer with standard laparoscopic view until they reach proficiency. Trainees work in pairs and time is recorded for each attempt. The primary outcome is mean total training time for each group. Secondary endpoints include procedural and knot quality subscore differences. Tertiary endpoints include studying the influence of gender and video game experience on performance. Discussion: This study addresses whether the learning of the psychomotor and visuospatial aspects of laparoscopic suturing and knot tying is optimal sequentially or simultaneously, by assessing total training time, procedural, and knot quality differences between the two groups. It will improve the efficiency of future laparoscopic suturing courses and may serve as an indicator for laparoscopic training in a broader context, i.e., not only for suturing and knot tying. Trial registration: This trial was registered on 12 August 2015 with the trial registration number DRKS00008668

The effectiveness and cost-effectiveness of acupressure for the control and management of chemotherapy-related acute and delayed nausea: Assessment of Nausea in Chemotherapy Research (ANCHoR), a randomised controlled trial

Chemotherapy-induced nausea and vomiting remain difficult symptoms to manage in clinical practice. As standard antiemetic drugs do not fully eliminate these symptoms, it is important to explore the adjuvant role of non-pharmacological and complementary therapies in antiemetic management approaches. Acupressure is one such treatment showing highly suggestive evidence so far of a positive effect, meriting further investigation

Correlated Strength in Nuclear Spectral Function

We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment confirms by direct measurement the correlated strength predicted by theory.Comment: 4 pages, 2 figures, accepted by Phys. Rev. Let

Microstructure casts during AIWEX : a summary

The Arctic Internal Wave Experiment (AIWEX) was designed to study the internal wave and microstructure fields in the Beaufort Sea in the early spring. A major goal of the experiment was to verify the hypothesis that the internal wave and microstructure fields beneath the ice are far less energetic than in temperate oceans. Major goals of the microstructure measurements were to characterize the double-diffusive staircase region in the depth range 300-450m, to estimate the heat flux from the deep Atlantic water into shallower depth zones, and to assess the influence of mesoscale and submesoscale eddies on turbulence beneath the ice. An ice camp was established in mid March 1985 to accomplish these goals. The camp was occupied until the first week of May, and microstructure casts were made beginning March 20 (Julian Day 79). Microstructure profiling continued until April 26; no profiles were obtained from April 4 through April 16 because of a malfunction in the data acquisition system. Over 700 casts were made spanning the range 0 to 500 m. The time between profiles averaged 20 minutes for a full-range profile. Not all casts covered the full depth range; some yo-yo casts through selected depth ranges were made to obtain detailed information on a shorter time scale. The ice camp drifted with a typical speed of 5 to 10 cm/s, although there were periods when the speed was as slow as 1 cm/s

First measurements of the ^16O(e,e'pn)^14N reaction

This paper reports on the first measurement of the ^16O(e,e'pn)^14N reaction. Data were measured in kinematics centred on a super-parallel geometry at energy and momentum transfers of 215 MeV and 316 MeV/c. The experimental resolution was sufficient to distinguish groups of states in the residual nucleus but not good enough to separate individual states. The data show a strong dependence on missing momentum and this dependence appears to be different for two groups of states in the residual nucleus. Theoretical calculations of the reaction using the Pavia code do not reproduce the shape or the magnitude of the data.Comment: 10 pages, 11 figures, 2 tables, Accepted for publication in EPJ

Measurements of electron-proton elastic cross sections for 0.4<Q2<5.5(GeV/c)20.4 < Q^2 < 5.5 (GeV/c)^2

We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 unique kinematic settings covering a range in momentum transfer of 0.4 $<$ $Q^2$ $<$ 5.5 $(\rm GeV/c)^2$. These measurements represent a significant contribution to the world's cross section data set in the $Q^2$ range where a large discrepancy currently exists between the ratio of electric to magnetic proton form factors extracted from previous cross section measurements and that recently measured via polarization transfer in Hall A at Jefferson Lab.Comment: 17 pages, 18 figures; text added, some figures replace

Obesity: A Biobehavioral Point of View

Excerpt: If you ask an overweight person, “Why are you fat?’, you will, almost invariably, get the answer, “Because 1 eat too much.” You will get this answer in spite of the fact that of thirteen studies, six find no significant differences in the caloric intake of obese versus nonobese subjects, five report that the obese eat significantly less than the nonobese, and only two report that they eat significantly more