Demonstration of vermicules of Babesia species in haemolymph smears of Amblyomma variegatum in Nigeria

The present study was conducted to investigate the presence of developmental stage (s) of Babesia species in Amblyomma variegatum. A total of 137 Amblyomma variegatum ticks (85 males and 52 females) were examined by haemolymph smears. Out of the examined male ticks, there were 41 nymphs and 44 adults. The female ticks were 23 nymphs and 29 engorged adults. Sixteen adult males and nine nymphs were positive for vermicules of Babesia species but only eight femalesshowed structures similar to Babesia vermicules. The present study recommends conducting molecular and experimental studies to confirm the type of Babesia parasite in Amblyomma variegatum tick

Epidemiology of Hepatitis B infection among pregnant women in Minna, Nigeria

A descriptive cross sectional study was conducted amongst 261 pregnant women attending ante natal clinic at General hospital, Minna, Nigeria to determine the social characteristics and seroprevalence of Hepatitis B Virus (HBV). The mean age of the respondents was 25years. Thirty two (12.3%) of the 261 blood samples tested positive for HBV. Of the the +ve cases, 13.6% were in the second trimester of their pregnancy and 60% within the age brackets of 21-30 years. Illiterate women constituted 15.9% of those sampled while civil servants were 13.6%. Testing for HBsAg is recommended for all pregnant women at first prenatal visit so that positive mothers receive prompt intervention. Key words: HBV, epidemiology, pregnant women, antenatal clinic, Minna, Nigeri

Haematological responses of three Nigerian goat breeds to field acquired helminthes infection and their haemoglobin types

Response of goats to natural helminth infection was investigated among 277 Nigerian indigenous goats belonging to three different breeds [West African dwarf (WAD), Red Sokoto (RS) and Sahel White (SW)] through the determination of parasitological and haematological parameters. The results showed that 65% of the sampled animals were positive for one helminth or two. Mixed infection due to Haemonchus contortus and Trichostrongylus colubriformis constituted 33.33% prevalence rate, while Haemonchus contortus and Oesophagostomum columbianum mixed infection had 26.67% rate of infection among the sampled animals. However, single infection due to either of Haemonchus contortus, Oesophagostomum columbianum, Trichostrongylus colubriformis, Strongyloides papilosus , Cooperia punctata , Trichuris ovis , Paramphistomum cervi and Moniezia benedini constituted 5.0%. There was no significant (p>0.05) difference in mean faecal egg count (FEC) among the breeds investigated. Similarly, correlation coefficient between Haemonchus worm count (HWC) and FEC showed positive correlation value which was significantly (p<0.01) higher among WAD (0.661) than SW (0.427) and RS (0.350) breeds. Three (3) different haemoglobin types (HbAA, HbAB and HbBB) were detected among the goats investigated. Goats with HbAA showed significantly (p<0.05) higher PCV compared to those with HbAB/HbBB alleles. In addition, Sahel White and Red Sokoto breeds had microcytic, hypochromic anaemia with a significantly (p<0.05) lower haematocrit values than the West African Dwarf breed. Eosinophil count of RS and SW goats did not vary significantly between the parasitized and the non-parasitized goats. However, in WAD, the eosinophil count was significantly higher (p<0.05) in parasitized than non-parasitized goats. In conclusion, the WAD breed appears to be more resistant to helminthes infections and H. contortus in particular, than RS and SW, and this may be due to high frequency of HbAA alleles in this breed. The advantage of this relative resistance could be exploited by crossbreeding WAD with other breeds

Acute toxicity study on aqueous extract of the leaf of Cassia sieberiana D.C. ( Caesalpiniaceae ) in albino rats

In order to evaluate the toxicity of Cassia sieberiana leaf extract in albino rats with the aim of establishing its safe application in experimental and field trials, the acute toxicity of the aqueous extract of the leaves was studied in albino rats. Four experimental groups of albino rats (A, B, C, D) were respectively given intraperitoneal doses of 400, 800, 1600 and 3200 mg/kg body weight of the extract, while the fifth group (E) was control. The LD50 was calculated, clinical signs and gross and microscopic lesions of the liver and kidney were recorded. Immediate clinical signs observed were weakness, depression, starry hair coat, anorexia, while abnormal gait, lordosis, opthalmia, coma and death appeared after 2 hours. Hepatomegaly and focal necrosis were observed on gross examination, while sinusoidal congestion with periportal necrosis and Kupffer cell proliferation were the microscopic lesions observed. Gross enlargement of the kidneys, vascular degeneration, and interstitial mononuclear cell infiltration were observed. The calculated median lethal dose (LD50) was 960 mg/kg, and the severity of clinical signs and hepatic and kidney lesions was dose dependent. This study has shown that Cassia sieberiana leaf aqueous extract could be toxic in a dose-dependent way, and should be used with caution in veterinary practice

In vitro assessment of trypanocidal activity of aqueous extract of Citrullus lanatus (Cucurbitaceae) (Thunb) leaf and its effects on the haematological parameters of Trypanosoma brucei infected albino rats

The in vitro antitrypanosomal activity of Citrullus lanatus leaf aqueous extract and its effects on blood parameters of Trypanosoma brucei infected albino rats was investigated in this study. The plant extract showed in vitro activity against T. brucei at a minimum concentration of 0.0875 mg/ml. There was a positive correlation between extract concentration and parasitaemia clearance, with administration of the extract at 10 mg/ml concentration resulting in zero parasitaemia count. Thirty albino rats divided into six groups (A-F) of five rats each were used for the haematological study. Graded extract doses of 200, 400 and 600 mg/kg were administered orally to groups A, B, and C respectively following an establishment of parasitaemia of 4 7 106 two days post infection. Group D (Veriben\uae 12treated) was given a single dose of 3.5 mg/kg diminazine aceturate (Veriben\uae) intramuscularly. Group E (Untreated) was not treated with any trypanocide but given 10 ml/kg of distilled water orally, while group F (Uninfected) were not infected with the parasites and did not receive any treatments. There was a significant (p<0.0001) decrease in mean packed cell volume (PCV) and red blood cell (RBC) counts of the infected and untreated group (E), when compared with the uninfected (F), and the infected but treated groups (A-D). The mean haemoglobin concentration was significantly (p<0.0001) higher in untreated uninfected and Veriben\uae 12treated albino rats compared with those treated with the extracts (A 12C) and the untreated infected rats (E). White blood cell (WBC) counts increased significantly (p<0.0001) in the untreated infected group (E) compared with the uninfected (F), extract-treated (A 12C) and Veriben\uae 12treated (D) groups. In conclusion, our investigation shows that the aqueous extract of C. lanatus leaf is toxic to T. brucei in vitro. However, in vivo studies are needed to demonstrate that it has any beneficial value in clearing parasites from infected animals

A collection of open problems in celebration of Imre Leader's 60th birthday

One of the great pleasures of working with Imre Leader is to experience his infectious delight on encountering a compelling combinatorial problem. This collection of open problems in combinatorics has been put together by a subset of his former PhD students and students-of-students for the occasion of his 60th birthday. All of the contributors have been influenced (directly or indirectly) by Imre: his personality, enthusiasm and his approach to mathematics. The problems included cover many of the areas of combinatorial mathematics that Imre is most associated with: including extremal problems on graphs, set systems and permutations, and Ramsey theory. This is a personal selection of problems which we find intriguing and deserving of being better known. It is not intended to be systematic, or to consist of the most significant or difficult questions in any area. Rather, our main aim is to celebrate Imre and his mathematics and to hope that these problems will make him smile. We also hope this collection will be a useful resource for researchers in combinatorics and will stimulate some enjoyable collaborations and beautiful mathematics

Design of a debris removal & on-orbit maintenance mission for mega-constellations

This paper shows the results of the design of a mission providing a service of maintenance and removal of mega-constellations. The innovative concept inspiring the design of DeBROOM 2 , Debris Removal and On-Orbit Maintenance Mission, is that a combination of different services can be performed in a modular and standardized way by a single unit servicing satellites in each orbital plane of the constellation. This is achieved through a servicer, which carries both the equipment to refuel target satellites and active-debris removal and propulsive kits, dedicated to the extension of the mission lifetime of cooperative OneWeb satellites, via the takeover of the attitude and orbital control system, as well as to de-orbit uncooperative faulty OneWeb satellites from LEO. The design covers all the areas of system level design, including the definition of system and mission requirements, concept of operations, and mission concept design, along with the design of the servicer and propulsive kits. The paper highlights and identifies the key challenges, the main drivers, and the major traded-off options during the mission concept design. Particular focus is given to the mission analysis aspects, with a computation of the delta-V that characterizes the key maneuvers necessary to serve one or a selection of orbital planes constituting the mega-constellation. The feasibility of the mission is demonstrated by the relevant budgets, along with the utilization of high TRL and COTS components in almost all the key elements of the mission

From Data to Software to Science with the Rubin Observatory LSST

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) dataset will dramatically alter our understanding of the Universe, from the origins of the Solar System to the nature of dark matter and dark energy. Much of this research will depend on the existence of robust, tested, and scalable algorithms, software, and services. Identifying and developing such tools ahead of time has the potential to significantly accelerate the delivery of early science from LSST. Developing these collaboratively, and making them broadly available, can enable more inclusive and equitable collaboration on LSST science. To facilitate such opportunities, a community workshop entitled "From Data to Software to Science with the Rubin Observatory LSST" was organized by the LSST Interdisciplinary Network for Collaboration and Computing (LINCC) and partners, and held at the Flatiron Institute in New York, March 28-30th 2022. The workshop included over 50 in-person attendees invited from over 300 applications. It identified seven key software areas of need: (i) scalable cross-matching and distributed joining of catalogs, (ii) robust photometric redshift determination, (iii) software for determination of selection functions, (iv) frameworks for scalable time-series analyses, (v) services for image access and reprocessing at scale, (vi) object image access (cutouts) and analysis at scale, and (vii) scalable job execution systems. This white paper summarizes the discussions of this workshop. It considers the motivating science use cases, identified cross-cutting algorithms, software, and services, their high-level technical specifications, and the principles of inclusive collaborations needed to develop them. We provide it as a useful roadmap of needs, as well as to spur action and collaboration between groups and individuals looking to develop reusable software for early LSST science.Comment: White paper from "From Data to Software to Science with the Rubin Observatory LSST" worksho

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe