2,353 research outputs found
Subject index and checklist of history and archaeology dissertations and research essays submitted at the University of Botswana, 1976 - 1998
Four MA dissertations and 222 BA research essays are listed alphabetically, and indexed by reference number under three subject categories-geographical area (by district, etc.), ethnic group, and a general subject index of 42 headings. All but 31 of the 226 alphabetical entries contain research solely on Botswana: the other countries being South Africa (12 entries), Zimbabwe (11), Namibia (6), Angola and Zambia (1 each). The most researched district of Botswana is Central (54 entries), followed by Kgatleng and Kweneng (25 each), North-East (24), South-East (16), Southern (9), Ngamiland (6), Chobe and Ghanzi (3 each), and Kgalagadi (2). The subject index of 29 ethnic groups ranges from Afrikaners (2 entries) and Amandebele (2) through Babirwa (7), Bakalanga (24), Bakgatla (27), Bakhalagari (4), Bakwena (21), Bangwato (19), Basarwa (5), and Batlharo (1), to Indians (3) and Ovambanderu (2). The general subject index ranges from Administration (29 entries), Agriculture (18), and Archaeology (21), through Biography (28), Cattle (7), Chieftainship (27), Class formation (7), Councils (7), Economic development (23), Education (14), and Heritage management (7), to Labour and labour migration (7), Medicine (4), Nationalism (13), Religion (15), Serfdom, servitude and slavery (7), Settlement history (19), Trade and commerce (13), Trade unions (6), and Urbanization (15). With the notable exception of one MA dissertation, there is a lack of cultural studies which may partly be attributed to research being done instead under the aegis of other departments in the Faculty of Humanities
Cysteine biosynthesis in Campylobacter jejuni: substrate specificity of CysM and the dualism of sulfide
Campylobacter jejuni is a highly successful enteric pathogen with a small, host-adapted genome (1.64 Mbp, ~1650 coding genes). As a result, C. jejuni has limited capacity in numerous metabolic pathways, including sulfur metabolism. Unable to utilise ionic sulfur, C. jejuni relies on the uptake of exogenous cysteine and its derivatives for its supply of this essential amino acid. Cysteine can also be synthesized de novo by the sole cysteine synthase, CysM. In this study, we explored the substrate specificity of purified C. jejuni CysM and define it as an O-acetyl-L-serine sulfhydrylase with an almost absolute preference for sulfide as sulfur donor. Sulfide is produced in abundance in the intestinal niche C. jejuni colonises, yet sulfide is generally viewed as highly toxic to bacteria. We conducted a series of growth experiments in sulfur-limited media and demonstrate that sulfide is an excellent sulfur source for C. jejuni at physiologically relevant concentrations, combating the view of sulfide as a purely deleterious compound to bacteria. Nonetheless, C. jejuni is indeed inhibited by elevated concentrations of sulfide and we sought to understand the targets involved. Surprisingly, we found that inactivation of the sulfide-sensitive primary terminal oxidase, the cbb3-type cytochrome c oxidase CcoNOPQ, did not explain the majority of growth inhibition by sulfide. Therefore, further work is required to reveal the cellular targets responsible for sulfide toxicity in C. jejuni
Dimension Spectra of Lines
This paper investigates the algorithmic dimension spectra of lines in the
Euclidean plane. Given any line L with slope a and vertical intercept b, the
dimension spectrum sp(L) is the set of all effective Hausdorff dimensions of
individual points on L. We draw on Kolmogorov complexity and geometrical
arguments to show that if the effective Hausdorff dimension dim(a, b) is equal
to the effective packing dimension Dim(a, b), then sp(L) contains a unit
interval. We also show that, if the dimension dim(a, b) is at least one, then
sp(L) is infinite. Together with previous work, this implies that the dimension
spectrum of any line is infinite
Dissecting pathways to thrombocytopenia in a mouse model of visceral leishmaniasis
Visceral leishmaniasis is an important yet neglected parasitic disease caused by infection with Leishmania donovani or L infantum. Disease manifestations include fever, weight loss, hepatosplenomegaly, immune dysregulation, and extensive hematological complications. Thrombocytopenia is a dominant hematological feature seen in both humans and experimental models, but the mechanisms behind this infection-driven thrombocytopenia remain poorly understood. Using a murine model of experimental visceral leishmaniasis (EVL), we demonstrated a progressive decrease in platelets from day 14 after infection, culminating in severe thrombocytopenia by day 28. Plasma thrombopoietin (TPO) levels were reduced in infected mice, at least in part because of the alterations in the liver microenvironment associated with granulomatous inflammation. Bone marrow (BM) megakaryocyte cytoplasmic maturation was significantly reduced. In addition to a production deficit, we identified significant increases in platelet clearance. L donovani–infected splenectomized mice were protected from thrombocytopenia compared with sham operated infected mice and had a greater response to exogenous TPO. Furthermore, infection led to higher levels of platelet opsonization and desialylation, both associated with platelet clearance in spleen and liver, respectively. Critically, these changes could be reversed rapidly by drug treatment to reduce parasite load or by administration of TPO agonists. In summary, our findings demonstrate that the mechanisms underpinning thrombocytopenia in EVL are multifactorial and reversible, with no obvious residual damage to the BM microenvironment
Randomized Benchmarking using Non-Destructive Readout in a 2D Atom Array
Neutral atoms are a promising platform for scalable quantum computing,
however prior demonstration of high fidelity gates or low-loss readout methods
have employed restricted numbers of qubits. Using randomized benchmarking of
microwave-driven single-qubit gates, we demonstrate single qubit gate errors of
on 225 atoms using conventional, destructive readout. This
exceeds the threshold for fault-tolerance. We further demonstrate suppression
of measurement errors via low-loss, non-destructive and state-selective readout
on 49 atoms. This enables post-selection for atom loss, which is a primary
source of errors in present setups.Comment: 6 pages, 4 figures plus Supplementary Materia
Low-Energy Electron-Track Imaging for a Liquid Argon Time-Projection-Chamber Telescope Concept using Probabilistic Deep Learning
The GammaTPC is an MeV-scale single-phase liquid argon
time-projection-chamber gamma-ray telescope concept with a novel dual-scale
pixel-based charge-readout system. It promises to enable a significant
improvement in sensitivity to MeV-scale gamma-rays over previous telescopes.
The novel pixel-based charge readout allows for imaging of the tracks of
electrons scattered by Compton interactions of incident gamma-rays. The two
primary contributors to the accuracy of a Compton telescope in reconstructing
an incident gamma-ray's original direction are its energy and position
resolution. In this work, we focus on using deep learning to optimize the
reconstruction of the initial position and direction of electrons scattered in
Compton interactions, including using probabilistic models to estimate
predictive uncertainty. We show that the deep learning models are able to
predict locations of Compton scatters of MeV-scale gamma-rays from simulated
pixel-based data to better than 0.6 mm RMS error, and are sensitive to the
initial direction of the scattered electron. We compare and contrast different
deep learning uncertainty estimation algorithms for reconstruction
applications. Additionally, we show that event-by-event estimates of the
uncertainty of the locations of the Compton scatters can be used to select
those events that were reconstructed most accurately, leading to improvement in
locating the origin of gamma-ray sources on the sky
Application of SWAT Hydrologic Model for TMDL Development on Chapel Branch Creek Watershed, SC
2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
Dinosaur tracks from the Kilmaluag Formation (Bathonian, Middle Jurassic) of Score Bay, Isle of Skye, Scotland, UK
Tracks of a juvenile theropod dinosaur with footprint lengths of between 2 and 9 cm as well as adults of the same ichnospecies with footprints of about 15–25 cm in length were found in the Bathonian (Middle Jurassic) Kilmaluag Formation of Score Bay, northwestern Trotternish Peninsula, Isle of Skye, Scotland, UK. Two footprint sizes occur together on the same bedding plane in the central portion of Score Bay, both in situ and on loose blocks. Another horizon containing footprints above this was also identified. The footprints from the lowest horizon were produced in a desiccated silty mud that was covered with sand. A close association of both adults and juveniles with similar travel direction indicated by the footprints may suggest post-hatching care in theropod dinosaurs. Other footprints, produced on a rippled sandy substrate, have been found on the slightly higher bedding plane at this locality. Loose blocks found 130 m to the northeast in the central part of Score Bay have not been correlated with any in situ sediments, but were preserved in a similar manner to those from the higher bedding plane. These tracks represent the youngest dinosaur remains yet found in Scotland
Dendritic growth of dapi-accumulating amacrine cells in the retina of the goldfish
The dendritic growth of amacrine cells was studied in the retina of the goldfish. Those cells that accumulated the intraocularly injected fluorescent dye 4,6-diamidino-2-phenylindole (DAPI) were compared in retinal wholemounts from small and large animals. Dendritic arbors were stained by intracellular injections of Lucifer yellow. Based upon their dendritic morphology, two types were identified, radiate and fusiform. The dendritic field areas and the number of dendritic terminals were quantitatively compared for cells in small retinas from young fish and large retinas from old fish in the region of the retina that grows by expansion. For both cell types the dendritic fields were significantly larger in the large retinas. The radiate cells had the same number of dendritic terminals in retinas of both sizes, whereas the fusiform cells in the large retinas had significantly more dendritic terminals than those in the small retinas. This resulted from the addition of new dendrites to the proximal arbor. These data show that with retinal expansion the pattern of dendritic growth by a amacrine cells is cell-type specific.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27694/1/0000080.pd
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