Brain thiamine homeostasis has an important role in energy metabolism and displays reduced activity in Alzheimer's disease (AD). Thiamine deficiency (TD) induces regionally specific neuronal death in ...the animal and human brains associated with a mild chronic impairment of oxidative metabolism. These features make the TD model amenable to investigate the cellular mechanisms of neurodegeneration. Once activated by various cellular stresses, including oxidative stress, PKR acts as a pro-apoptotic kinase and negatively controls the protein translation leading to an increase of BACE1 translation. In this study, we used a mouse TD model to assess the involvement of PKR in neuronal death and the molecular mechanisms of AD. Our results showed that the TD model activates the PKR-eIF2α pathway, increases the BACE1 expression levels of Aβ in specific thalamus nuclei and induces motor deficits and neurodegeneration. These effects are reversed by PKR downregulation (using a specific inhibitor or in PKR knockout mice).
Schalk Pienaar, a leading Afrikaner journalist, encouraged soul-searching amongst Afrikaners about their treatment of the black majority, while urging the necessity to adapt to a modern and changing ...world if they wanted to survive in Africa. Dr A.P. Treurnicht, an influential ultra-conservative establishment figure, and a future leader of the right-wing Conservative Party, on the other hand believed with evangelical fervour that any departure from the system of racial separation, however trivial, would endanger Afrikaner survival. The result was a long and bitter feud with Pienaar which had a profound influence on the apartheid state as it did much to discredit Treurnicht in the eyes of many Afrikaners, preparing them to accept political change.
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We present the first search for a dark matter annual modulation signal in the Southern Hemisphere conducted with NaI(Tl) detectors, performed by the DM-Ice17 experiment. Nuclear recoils from dark ...matter interactions are expected to yield an annually modulated signal independent of location within the Earth’s hemispheres. DM-Ice17, the first step in the DM-Ice experimental program, consists of 17 kg of NaI(Tl) located at the South Pole under 2200 m.w.e. overburden of Antarctic glacial ice. Taken over 3.6 years for a total exposure of 60.8 kg yr, DM-Ice17 data are consistent with no modulation in the energy range of 4–20 keV, providing the strongest limits on weakly interacting massive particle dark matter from a direct detection experiment located in the Southern Hemisphere. The successful deployment and stable long-term operation of DM-Ice17 establishes the South Pole ice as a viable location for future dark matter searches and in particular for a high-sensitivity NaI(Tl) dark matter experiment to directly test the DAMA/LIBRA claim of the observation of dark matter.
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The aim of the study was to determine the space use of individuals in a multi-male group of the armadillo lizard Cordylus cataphractus. Specific focus was on the adult males and females of the group, ...because, ultimately, the manner in which adult males and females utilize space determines the mating system. A two-dimensional (2D) grid pattern was delineated at the crevice of a free-living, multi-male group to facilitate the recording of the positions of individuals during observations. All marked individuals (n=55) that were visible were scanned through a telescope, and their respective positions were recorded at 30-min intervals over several days during the breeding season. Arcview 3.2 Geographical Information Software was used to create a computerized replicate of the 2D grid pattern at the crevice and to depict graphically the recorded positions for each individual using a minimum convex polygon procedure. From the polygons generated by this procedure, it was clear that the space use of adult males overlapped greatly with the space use of adult females, but that there was no overlap in space-use among adult males. Space use overlapped greatly among subadults and juveniles and also among these size classes and adult males and females. Adult male C. cataphractus are territorial, defending specific sites at the crevice. The territory of each male in the group incorporated at least one female. The space use of several females overlapped with the space use of two or more males. Males were observed to mate with one or more females, and one female was observed to mate with two different males on more than one occasion. Cordylus cataphractus males display typical territorial polygyny whereas females may be promiscuous.
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The Jameson Raid of December 1895 estranged the two white groups in South Africa and contributed to the outbreak of the South African War of 1899-1902. With the rise of Afrikaner nationalism in the ...twentieth century the perception that L.S. Jameson (1853-1917) was the cause of all tension and rivalry between the two white groups became entrenched. And yet, Jameson as leader of the Unionist Party between 1910 and 1912 did his utmost to atone for the damage done by his reckless Raid. He publicly lauded Botha’s ability and integrity and this played a crucial role in diluting the anti-Afrikaner attitude of many English-speakers, convincing them to accept an Afrikaner dominated government. In addition his encouragement of a South African identity within the Empire, and his restraint on the anger and opposition to bilingualism by English-speakers supported Botha’s conciliation and nation building policies. Jameson helped to lay the foundation of a South African nation within the British Empire.Keywords: L.S. Jameson (1853-1917), Unionist Party, Jameson Raid, conciliation. Union of South Africa, South African War, British Empire, South AfricanismDisciplines: History, Political Studies
This study examined the effects of a giant (4×3 m) exercising board game intervention on ambulatory physical activity (PA) and a broader array of physical and psychological outcomes among nursing ...home residents.
A quasi-experimental longitudinal study was carried out in two comparable nursing homes. Ten participants (aged 82.5±6.3 and comprising 6 women) meeting the inclusion criteria took part in the 1-month intervention in one nursing home, whereas 11 participants (aged 89.9±3.1 with 8 women) were assigned to the control group in the other nursing home. The giant exercising board game required participants to per-form strength, flexibility, balance and endurance activities. The assistance provided by an exercising specialist decreased gradually during the intervention in an autonomy-oriented approach based on the self-determination theory. The following were assessed at baseline, after the intervention and after a follow-up period of 3 months: PA (steps/day and energy expenditure/day with ActiGraph), cognitive status (mini mental state examination), quality of life (EuroQol 5-dimensions), motivation for PA (Behavioral Regulation in Exercise Questionnaire-2), gait and balance (Tinetti and Short Physical Performance Battery), functional mobility (timed up and go), and the muscular isometric strength of the lower limb muscles.
In the intervention group, PA increased from 2,921 steps/day at baseline to 3,358 steps/day after the intervention (+14.9%,
=0.04) and 4,083 steps/day (+39.8%,
=0.03) after 3 months. Energy expenditure/day also increased after the intervention (+110 kcal/day, +6.3%,
=0.01) and after 3 months (+219 kcal/day, +12.3%,
=0.02). Quality of life (
<0.05), balance and gait (
<0.05), and strength of the ankle (
<0.05) were also improved after 3 months. Such improvements were not observed in the control group. The preliminary results are promising but further investigation is required to confirm and evaluate the long-term effectiveness of PA interventions in nursing homes.
High quality road infrastructure is essential to support economic growth for any region. For South Africa’s landlocked economic hub 79% of goods are transported using roads infrastructure. Protection ...of the road infrastructure is implemented by means of overload control monitoring at traffic control centres (TCCs) on freight corridors. Statistics collected from TCC operations indicate that 75% to 85% of statically weighed vehicles are legally loaded, with the implication that unnecessary time was wasted for these vehicles. This paper therefore proposes an algorithm, called the intelligent weigh-in-motion (IWIM) algorithm, with the purpose to decrease static weighing of vehicles by implementing data sharing between TCCs on the freight corridor, combined with intelligent interpretation of this data. The selected algorithm was chosen after testing multiple artificial intelligence (AI) models (logistic regression, random forest tree, and artificial neural network) to achieve the best performance to decrease static weighing of vehicles while not increasing the number of overloaded vehicles allowed to proceed on the corridor. The best performing model to differentiate between overloaded and legal vehicles, random forest tree, achieved an average improvement of 65,83% in terms of vehicles to be statically weighed when compared to the current rule-based system employed at TCCs.
There is a high incidence of melanism among the cordylid lizards of Africa and it was suggested that melanism has a thermoregulatory function in these species. One prediction of the thermal melanism ...hypothesis would be that melanistic cordylid species would be restricted to cool environments. The aim of our study was to determine the climatic conditions with which melanistic cordylids are currently associated. Distributional data for the eight melanistic cordylid taxa occurring at the south-western tip of Africa were obtained from the CapeNature State of Biodiversity database. Using GIS and principal component analyses, the climatic variables best describing the geographical distribution of melanistic cordylids were investigated. We found that several melanistic cordylid populations show a distinct association with a high incidence of fog and cloud cover, underscoring the thermal melanism hypothesis. Several other populations, however, do not show such an association. We conclude that some species, such as Pseudocordylus capensis, have a morphology that provides them with great flexibility in habitat use, allowing them to overcome the constraints of melanism in warm environments. The available information suggests that melanism in cordylids evolved during the Miocene in response to the development of the cold Benguela Current along the west coast of Africa. We also conclude that viviparity, a sit-and-wait foraging strategy and a rock-dwelling lifestyle would have preadapted cordylids for survival in cool conditions brought about by the development of the cold Benguela Current. These conditions would have been unfavourable for oviparous, active-foraging lizards. The co-occurrence of melanistic lizards and melanistic molluscs at the Landdroskop locality casts some doubt on improved heating rates as the only explanation for melanism in cordylids, because molluscs are not heliothermic baskers.
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