2,844 research outputs found
Design and Tests of the Silicon Sensors for the ZEUS Micro Vertex Detector
To fully exploit the HERA-II upgrade,the ZEUS experiment has installed a
Micro Vertex Detector (MVD) using n-type, single-sided, silicon micro-strip
sensors with capacitive charge division. The sensors have a readout pitch of
120 micrometers, with five intermediate strips (20 micrometer strip pitch). The
designs of the silicon sensors and of the test structures used to verify the
technological parameters, are presented. Results on the electrical measurements
are discussed. A total of 1123 sensors with three different geometries have
been produced by Hamamatsu Photonics K.K. Irradiation tests with reactor
neutrons and Co-60 photons have been performed for a small sample of sensors.
The results on neutron irradiation (with a fluence of 1 x 10^{13} 1 MeV
equivalent neutrons / cm^2) are well described by empirical formulae for bulk
damage. The Co-60 photons (with doses up to 2.9 kGy) show the presence of
generation currents in the SiO_2-Si interface, a large shift of the flatband
voltage and a decrease of the hole mobility.Comment: 33 pages, 25 figures, 3 tables, accepted for publication in NIM
Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector
For the HERA upgrade, the ZEUS experiment has designed and installed a high
precision Micro Vertex Detector (MVD) using single sided micro-strip sensors
with capacitive charge division. The sensors have a readout pitch of 120
microns, with five intermediate strips (20 micron strip pitch). An extensive
test program has been carried out at the DESY-II testbeam facility. In this
paper we describe the setup developed to test the ZEUS MVD sensors and the
results obtained on both irradiated and non-irradiated single sided micro-strip
detectors with rectangular and trapezoidal geometries. The performances of the
sensors coupled to the readout electronics (HELIX chip, version 2.2) have been
studied in detail, achieving a good description by a Monte Carlo simulation.
Measurements of the position resolution as a function of the angle of incidence
are presented, focusing in particular on the comparison between standard and
newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM
Changing teacher perspectives: Game-based scenario writing.
A group of Dutch teachers, as part of their Masterâs programme, developed a game that allows teachers to break free from their day-to-day affairs and reflect on futures by designing scenarios about the future of their school. In this game-based approach the journey of scenario exploration is composed of seven steps: (1) choice of a theme and timeframe, (2) selection of key dilemmas on which two scenario axes will be based, (3) understanding the content and context of a âmatrixâ provided for the game, (4) setting up scenario groups, (5) developing four scenarios, (6) sharing scenarios, and (7) reflection on the scenarios
The route and timing of hydrogen sulfide therapy critically impacts intestinal recovery following ischemia and reperfusion injury
PURPOSE:
Hydrogen sulfide (H2S) has many beneficial properties and may serve as a novel treatment in patients suffering from intestinal ischemia-reperfusion injury (I/R). The purpose of this study was to examine the method of delivery and timing of administration of H2S for intestinal therapy during ischemic injury. We hypothesized that 1) route of administration of hydrogen sulfide would impact intestinal recovery following acute mesenteric ischemia and 2) preischemic H2S conditioning using the optimal mode of administration as determined above would provide superior protection compared to postischemic application.
METHODS:
Male C57BL/6J mice underwent intestinal ischemia by temporary occlusion of the superior mesenteric artery. Following ischemia, animals were treated according to one of the following (N=6 per group): intraperitoneal or intravenous injection of GYY4137 (H2S-releasing donor, 50mg/kg in PBS), vehicle, inhalation of oxygen only, inhalation of 80ppm hydrogen sulfide gas. Following 24-h recovery, perfusion was assessed via laser Doppler imaging, and animals were euthanized. Perfusion and histology data were assessed, and terminal ileum samples were analyzed for cytokine production following ischemia. Once the optimal route of administration was determined, preischemic conditioning with H2S was undertaken using that route of administration. All data were analyzed using Mann-Whitney. P-values <0.05 were significant.
RESULTS:
Mesenteric perfusion following intestinal I/R was superior in mice treated with intraperitoneal (IP) GYY4137 (IP vehicle: 25.6±6.0 vs. IP GYY4137: 79.7±15.1; p=0.02) or intravenous (IV) GYY4137 (IV vehicle: 36.3±5.9 vs. IV GYY4137: 100.7±34.0; p=0.03). This benefit was not observed with inhaled H2S gas (O2 vehicle: 66.6±11.4 vs. H2S gas: 81.8±6.0; p=0.31). However, histological architecture was only preserved with intraperitoneal administration of GYY4127 (IP vehicle: 3.4±0.4 vs. IP GYY4137: 2±0.3; p=0.02). Additionally, IP GYY4137 allowed for significant attenuation of inflammatory chemokine production of IL-6, IP-10 and MIP-2. We then analyzed whether there was a difference between pre- and postischemic administration of IP GYY4137. We found that preconditioning of animals with intraperitoneal GYY4137 only added minor improvements in outcomes compared to postischemic application.
CONCLUSION:
Therapeutic benefits of H2S are superior with intraperitoneal application of an H2S donor compared to other administration routes. Additionally, while intraperitoneal treatment in both the pre- and postischemic period is beneficial, preischemic application of an H2S donor was found to be slightly better. Further studies are needed to examine long term outcomes and further mechanisms of action prior to widespread clinical application.
TYPE OF STUDY:
Basic science.
LEVEL OF EVIDENCE:
N/A
Calvin, Van Lodenstein and Barth: Three perspectives on the necessity of church reformation
Emerging ecumenical church polity, 1965-2010 : lessons from efforts at church unity in Zambia
This article explores an emerging ecumenical church polity in Zambia from a
church historical perspective. While church polity and church unity literature
has acknowledged the role of church polity and church unity in Zambia, and its
use for ecclesiological purposes, the growing use of church polity and the efforts
at church unity in the period 1965â2010 in Zambia, have remained unexamined.
This article thus explores qualitatively how church polity and church unity were
viewed in church legislation and official church documents of the United
Church of Zambia (UCZ), the Anglican Church in Zambia (ACZ) and the
Uniting Presbyterian Church in Southern Africa (UPCSA) in Zambia. The
article observes that ecumenical church polity has indeed been developed in
Zambia and lessons from efforts at church unity in Zambia can assist in
developing ecumenical church polity. This is demonstrated by comparing the
church legislation and by studying lessons from efforts at church unity within
the ranks of the UCZ, ACZ and UPCSA, among other ways. The article
therefore advances the argument that ecumenical church polity can be
developed by comparing the church legislation provisions and by studying the
lessons from efforts at church unity in Zambia. This article contributes to the
field of church history, church polity and ecclesiology.https://upjournals.co.za/index.php/SHEpm2021Church History and Church Polic
SASPEN Case Study
Prenatally, the patient was diagnosed with dilated intestinal loops. The patient, born at term, was diagnosed with gastroschisis during the neonatal term
Observation of isolated high-E_T photons in deep inelastic scattering
First measurements of cross sections for isolated prompt photon production in
deep inelastic ep scattering have been made using the ZEUS detector at the HERA
electron-proton collider using an integrated luminosity of 121 pb^-1. A signal
for isolated photons in the transverse energy and rapidity ranges 5 < E_T^gamma
< 10 GeV and -0.7 < eta^gamma < 0.9 was observed for virtualities of the
exchanged photon of Q^2 > 35 GeV^2. Cross sections are presented for inclusive
prompt photons and for those accompanied by a single jet in the range E_T^jet
\geq 6 GeV and -1.5 \leq eta^jet < 1.8. Calculations at order alpha^3alpha_s
describe the data reasonably well.Comment: 16 pages, 5 figure
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