Antihydrogen and mirror-trapped antiproton discrimination: Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap

Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antiproton and antihydrogen trajectories in this magnetic geometry, and reconstruct the antihydrogen energy distribution from the measured annihilation time history.Comment: 17 figure

A revisit of oral and maxillofacial mortality from orofacial infections in a resource limited setting: Is there a need for a change in management protocol?

Background: Orofacial infections are communicable infections usually of odontogenic origin, they often present as rapidly spreading infection involving the fascial spaces of the head and neck. When they are not promptly and adequately intercepted, they may result in fatal outcomes. The common pathway to mortality in these patients is often airway compromise. The advent of antibiotics and improvement in quality of health care has been said to improve the success rate in the management of orofacial infections, however the findings from our setting showed that the mortality from orofacial infections have remained high.Objective: To report mortalities from patients managed for orofacial infections in our center, review our treatment protocol and ascertain the necessity for a change in management protocolDesign: A retrospective study Setting: Maxillofacial surgery department of Aminu Kano Teaching Hospital (AKTH) Kano, Kano state Nigeria.Subjects: All patients who died in our facility over a one hundred and thirty eight-month period (January 2005 – June 2016) following management of orofacial infectionsResults: A total of 115 (76 males, 39 females) maxillofacial admissions were recorded on account of orofacial infection during the period under review; of these 26 mortalities were recorded (22.6%). Male subjects constituted 19 cases while female subjects were 7 in number. The demised patients’ ages ranged from 19 years to 73 years with a mean age of 34.0 ± 12.0 years.Conclusion: Orofacial infections are potentially lethal; they constitute one of the commonest causes of mortality in maxillofacial surgery facilities. A standard care of early intervention, aggressive medical and surgical therapy has consistently provided the best results

Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1

The DEAP-1 low-background liquid argon detector was used to measure scintillation pulse shapes of electron and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination (PSD) down to an electron-equivalent energy of 20 keV. In the surface dataset using a triple-coincidence tag we found the fraction of beta events that are misidentified as nuclear recoils to be $<1.4\times 10^{-7}$ (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil acceptance of at least 90%, with 4% systematic uncertainty on the absolute energy scale. The discrimination measurement on surface was limited by nuclear recoils induced by cosmic-ray generated neutrons. This was improved by moving the detector to the SNOLAB underground laboratory, where the reduced background rate allowed the same measurement with only a double-coincidence tag. The combined data set contains $1.23\times10^8$ events. One of those, in the underground data set, is in the nuclear-recoil region of interest. Taking into account the expected background of 0.48 events coming from random pileup, the resulting upper limit on the electronic recoil contamination is $<2.7\times10^{-8}$ (90% C.L.) between 44-89 keVee and for a nuclear recoil acceptance of at least 90%, with 6% systematic uncertainty on the absolute energy scale. We developed a general mathematical framework to describe PSD parameter distributions and used it to build an analytical model of the distributions observed in DEAP-1. Using this model, we project a misidentification fraction of approx. $10^{-10}$ for an electron-equivalent energy threshold of 15 keV for a detector with 8 PE/keVee light yield. This reduction enables a search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of $10^{-46}$ cm$^2$, assuming negligible contribution from nuclear recoil backgrounds.Comment: Accepted for publication in Astroparticle Physic

Primary Hyperparathyroidism Presenting with Multiple Pathological Fractures and Normocalcaemia

The diagnosis of primary hyperparathyroidism (PHPT) is a rarity in developing countries. We report a 30-year old Nigerian farmer seen at the Usmanu Danfodiyo University Teaching Hospital, Sokoto with multiple pathological fractures. The diagnosis of PHPT was made based on these bone changes and the elevated parathyroid hormone level. The patient however had normocalcaemia. Computerised tomography localised a left inferior parathyroid adenoma. He had uneventful parathyroidectomy but developed hungry bone syndrome that was successfully treated with active vitamin D and oral calcium. The differences in presentation between patients from developed countries as well as the apparent rarity of PHPT in tropical countries are stressed

Human cytomegalovirus infection, viraemia and retinitis among people living with HIV/AIDS in Kano, North-Western Nigeria

Background: Human cytomegalovirus (HCMV) is a leading cause of opportunistic infection in HIV-infected patients. HCMV viraemia is an active infection marker and prelude to end-organ diseases (EODs), such as retinitis. The aim of the study was to assess the burden and associated factors of HCMV infection, viraemia and retinitis among HIV-infected patients in Nigeria.Methods: Comparative cross-sectional study of 160 HIV-infected adults, comprising 80 participants in each of &lt;100/mm3 and ≥100 cells/mm3 CD4+ cell count groups, who attended HIV clinic at a tertiary hospital located in a major Nigerian city.  A questionnaire was used to collect data from eligible consenting participants and their case files. Sera from all participants were tested for anti-HCMV IgG using ELISA method, and plasma of seropositive participants were subjected to PCR for HCMV viraemia. Participants whose samples were HCMV viraemic were examined for HCMV retinitis using indirect ophthalmoscopy. Data was analyzed using Minitab vs 14.1.1PP.Results: All 160 participants tested positive for anti-HCMV IgG. HCMV viraemia was 14.4% (23 of 160) generally, but comparatively more among &lt;100 CD4 cells/mm3 group (18.8%; 15 of 80) than in ≥100 cells/mm3 patient group (10%; 8 of 80). Only HCMV viraemic patients in &lt;100 CD4 cells/mm3 group (20%; 3 of 15) were diagnosed with HCMV retinitis. WHO stage was associated with HCMV viraemia (χ2= 7.79, p=0.05) and HCMV retinitis (χ2= 4.60, p=0.03). The only predictor of HCMV retinitis was WHO staging I and II [aOR = 0.04, 95%CI (0.01- 0.52)].  Conclusions: Evidence of previous and active HCMV infection is prevalent among PLWHA in Nigeria with WHO staging being associated and a predictor of HCMV viraemia and retinitis, respectively

Fate of ingested linamarin in malnourished rats

Pure linamarin at a dose level of 30 g per 100 g body weight was administered in food to a group of Wistar rats maintained on vitamin B2-deficient, sufficient and excess diets for 5 weeks and to another group of kwashiorkor rats. Free and total cyanide, intact linamarin and thiocyanate levels were estimated in urine and faeces obtained at 0-, 24-, 48- and 72-h periods and in blood samples obtained in the seventy-second hour after the drug had been administered. There was no detectable cyanide or intact linamarin in the faecal samples. Vitamin B2-sufficient and excess groups of rats excreted higher total and free cyanide than the respective vitamin B2-deficient groups. Most of the linamarin was degraded after the first 24h. The rate of breakdown of the glucoside within the first 24 h was slowest for the zero and half normal vitamin B2 status, respectively, as evidenced by its appearance in large quantities in the urine. The kwashiorkor rats, on the other hand, excreted less thiocyanate than the controls. In addition, their control group excreted most of the thiocyanate (SCN−) in the first 24 h whilst the kwashiorkor rats excreted theirs in the first 48 h. Dietary protein deficiency prolongs the time of metabolism and hence increases the toxicity of cyanogenic glycoside in the body. It is also suggested that excessive exposure of malnourished humans to cyanide could be a contributory factor in the rampant cases of tropical ataxic neuropathy (TAN)

Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus

Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited

\u3cem\u3eIn vitro\u3c/em\u3e Digestibility and Methane Production of Two Tropical Grasses: Plant Spacing and Grazing Frequency

This study was carried out to investigate the influence of plant spacing and grazing frequency on the in vitro gas production, digestibility, and methane production of Guinea grass (Megathyrsus maximus) and Elephant grass (Cenchrus purpureus) in the humid southwest part of Nigeria. The experiment was laid in a 2 x 2 x 2 factorial arrangement in a split-split-plot design with three replicates, which consisted of two grazing frequency (3 and 6-week) as the main plot, two grass species: Guinea grass (M. maximus) and Elephant grass (C. purpureus) as the sub plot and two plant spacing (1m x 1m and 0.5m x 1m) as the sub-sub plot. A total area of 2496 m2 of an existing plot established April 2019 was used in conducting this experiment. In May 2020, the grasses were cut back at the commencement of this experiment to 15cm above ground surface and NPK 20:10:10 fertilizer was applied 8 days after cut back at the rate of 120 kg N/ha. The result showed a significant (Pin vitro gas production, digestibility (IVDMD) and methane gas production. The CP content of C. purpureus (18.14 %) grazed at 3-week GF with 1 m x 1 m spacing was significantly (PM. maximus grazed at 3-week at the narrower spacing with the IVDMD been the highest (64.53% DM) and the least gas volume was produced by C. purpureus grazed at 3-week with a narrower spacing, whereas the least digested was C. purpureus grazed at 6-week with narrower spacing. The methane production of C. purpureus grazed at 3-week with wider spacing was the least (5.53 ml/200mg DM) while the highest methane was produced by M. maximus also grazed at 3-week with 0.5m x 1m spacing though not statistically (P\u3e0.05) different from the methane of same species with same plant spacing at 6-week grazing frequency. It can be concluded that grazing at 3-week grazing frequency and narrower spacing will help reduce methane for C. purpureus and improve digestibility for M. maximus