Frequency distributions of stone artefacts from Holkrans, North West Province, South Africa

BSc Honours Thesis University of the WitwatersrandExcavations at Holkrans rock shelter, located in the Vredefort Dome, Southern Africa, revealed archaeological deposits dating back some 2000 years, to both the ceramic and pre-ceramic Later Stone Age. The ceramic phase, placed within the last 500 years by radiocarbon dates, was likely contemporary with the Late Iron Age stone-walled structures in the nearby area. The pre-ceramic phase dates from the early first millennium BC to about 1000 AD. This pilot study examined a sample of lithics from the base of the shelter mouth using a standard typology and frequency distribution as a first step to a more extensive study to be conducted in the near future. Analysis revealed a substantial temporal gap in shelter occupation between the ceramic and pre-ceramic levels, largely in agreement with the observations of Bradfield and Sadr (2011) who noted raw material and possible technological differences between these layers. New radiocarbon dates suggest a series of punctuated occupations during the pre-ceramic levels and more regular occupation during the ceramic phase. How did contact with early farmers influence the archaeology of Holkrans? With few other shelters known in the area, research at Holkrans has the potential to fill a physical gap among known Later Stone Age sites in the southern African interior

Google Earth and GIS reveal settlement patterns associated with stone circles, southern Gauteng, South Africa

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science.Unable to load abstract

HIV-fertőzött személyek neurokognitív eltérései - hazai prevalenciavizsgálat előzetes eredményei

BACKGROUND AND PURPOSE: The outcome of HIV infection has dramatically improved due to the widespread use of combined antiretroviral therapy (cART). Opportunistic infections faded and internal and hemato-oncological diseases along with neurological conditions came to the forth. Present study is to evaluate neurocognitive performance of the Hungarian HIV infected individuals, at first in this setting Patients and methods - We performed this cross-sectional pilot study within the frames of a national, single-center; prospective study on group of HIV infected patients, analyzing medical data and neurocognitive performance. Based on international recommendations visual memory, visuomotor coordination, non-verbal learning ability, executive functions and reaction time were tested by six domains of a computerized neuropsychological test battery (Vienna Test System). RESULTS: Data of 59 enrolled HIV individuals were analysed; nine of whom were women (15%), median age 42.6 (IQR: 32.4-48.1) years. In 32.2% (n=19) of patients neurocognitive impairment was detected. Duration of infection and cART treatment time tended to be longer in impaired group (not significant). Lower CD4 cell count at the time of examination (p=0.047), psychiatric diseases other than depression (p=0.005) were found significantly associated with impairment; tertiary education qualification were more common (p=0.033) among non-affected patients. By correlation analysis age, infected time and duration of cART were significantly associated with motor deficit. CONCLUSION: HAND was detected in almost one third part of examined patients, which largely corresponds that in developed countries were observed. Duration of infection and of cART therapy associated motor deficit was found to be the most common impairment. This finding might be interpreted by direct effect of HIV, neurotoxicity of antiretro virals and also by accelerated ageing of this population

Prediction of Wind Fields using Weather Pattern Recognition: Analysis of Sailing Strategy and Real Weather Data in Tokyo 2020 Olympics

The Tokyo 2020 Olympic Sailing Competitions were held in Enoshima Bay between the 25th of July and the 4th of August 2021. The climatological and the strategical analysis of the race area for the Swedish Sailing Team was developed in the three years prior to the Olympics (Masino et al., 2021). The result of the three years’ research was a tool named ”Call Book” that provides strategical rules for sailors and coaches both in terms of expected ranges of wind speed and direction and also in terms of trends with explanations for each identified weather pattern. The support team was working not only on the forecast but also on the specific analysis of the weather data in the race areas as measured on the water by the Olympics organising authorities and monitored through the SAP Analytics website (SAP Sailing Analytics, 2021). Two race areas are herein taken into consideration, namely Enoshima and Zushi, where the Swedish Team athletes sailed most of the races. A statistical meta-analysis on the comparison between the forecast issued using the ”Call Book” and measured data on the race areas is carried out, investigating the specific outcome of the strategy of the races with the forecasted meteorological data

The effect of thermo-oxidative aging on the durability of glass fiber-reinforced epoxy

Thin-skinned organic matrix composites within aeronautical structures are subjected to thermooxidative aging during their service life, leading to reductions in their durability. In this paper, a durability evaluation of fiberglass epoxy prepreg is performed on the original composite thickness before and after 800 h isothermal aging at 82°C. The characterization of both aged and unaged composites comprised tensile tests, DMA, FTIR, weight loss measurements, SEM, and DSC. The tensile strength and modulus of the composites increased after being exposed to pronounced aging conditions, whereas a decrease was observed in the toughness. DMA results revealed that the glass transition temperature and rubbery state modulus increased as a result of the thermooxidative aging. FTIR spectroscopy demonstrated the formation of carbonyl compounds due to oxidation of the chemical structure of the resin. SEM observations indicated the existence of minor superficial cracking and poor fiber-matrix adhesion after aging. In addition, a minor mass change was observed from mass loss monitoring methods. The overall findings suggest that postcuring and physical aging enhanced the brittleness of the resin, leading to a significant decline in the useful structural life of the thin-skinned composite

Effect of pulsed electromagnetic fields on endoplasmic reticulum stress

The maintenance of protein homeostasis in the endoplasmic reticulum (ER) is crucial in cell life. Disruption of proteostasis results in ER stress that activates the unfolded protein response (UPR); a signalling network assigned to manage the accumulated misfolded or unfolded proteins. Prolonged or unresolved ER stress leads to apoptotic cell death that can be the basis of many serious diseases. Our aim was to study the effect of pulsed electromagnetic fields (PEMF), an alternative, non-invasive therapeutic method on ER stressed cell lines. First, the effect of PEMF treatment on the expression of ER stress markers was tested in three different cell lines. PEMF had no remarkable effect on ER stress protein levels in human embryonic kidney (HEK293T) and human liver carcinoma (HepG2) cell lines. However, the expression of BiP, Grp94 and CHOP were increased in HeLa cells upon PEMF exposure. Therefore, HepG2 cell line was selected for further experiments. Cells were stressed by tunicamycin and exposed to PEMF. Grp94, PDI, CHOP and PARP expression as markers of stress were monitored by Western blot and cell viability was also investigated. Tunicamycin treatment, as expected, increased the expression of Grp94, PDI, CHOP and inactivated PARP. Analysis of protein expression showed that PEMF was able to decrease the elevated level of ER chaperons Grp94, PDI and the apoptosis marker CHOP. The truncated, inactive form of PARP was also decreased. Accordingly, cell viability was also improved by PEMF exposure. These results indicate that PEMF is able to moderate ER stress induced by tunicamycin in HepG2 cells. However, our results clearly draw attention to that different cell lines may vary in the response to PEMF treatment. © 2016, Polish Physiological Society. All rights reserved

Conformational change of the catalytic subunit of glucose-6-phosphatase in rat liver during the fetal-to-neonatal transition

The glucose-6-phosphatase system was investigated in fetal rat liver microsomal vesicles. Several observations indicate that the orientation of the catalytic subunit is different in the fetal liver in comparison with the adult form: (i) the phosphohydrolase activity was not latent using glucose- 6-phosphate as substrate, and in the case of other phosphoesters it was less latent; (ii) the intravesicular accumulation of glucose upon glucose-6- phosphate hydrolysis was lower; (iii) the size of the intravesicular glucose- 6-phosphate pool was independent of the glucose-6-phosphatase activities; (iv) antibody against the loop containing the proposed catalytic site of the enzyme inhibited the phosphohydrolase activity in fetal but not in adult rat liver microsomes. Glucose-6-phosphate, phosphate, and glucose uptake could be detected by both light scattering and/or rapid filtration method in fetal liver microsomes; however, the intravesicular glucose-6-phosphate and glucose accessible spaces were proportionally smaller than in adult rat liver microsomes. These data demonstrate that the components of the glucose-6- phosphatase system are already present, although to a lower extent, in fetal liver, but they are functionally uncoupled by the extravesicular orientation of the catalytic subunit

Suppression of AMPK/aak-2 by NRF2/SKN-1 down-regulates autophagy during prolonged oxidative stress.

NF-E2-related factor 2 (NRF2) transcription factor has a fundamental role in cell homeostasis maintenance as one of the master regulators of oxidative and electrophilic stress responses. Previous studies have shown that a regulatory connection exists between NRF2 and autophagy during reactive oxygen species-generated oxidative stress. The aim of the present study was to investigate how autophagy is turned off during prolonged oxidative stress, to avoid overeating and destruction of essential cellular components. AMPK is a key cellular energy sensor highly conserved in eukaryotic organisms, and it has an essential role in autophagy activation at various stress events. Here the role of human AMPK and its Caenorhabditis elegans counterpart AAK-2 was explored upon oxidative stress. We investigated the regulatory connection between NRF2 and AMPK during oxidative stress induced by tert-butyl hydroperoxide (TBHP) in HEK293T cells and C. elegans. Putative conserved NRF2/protein skinhead-1 binding sites were found in AMPK/aak-2 genes by in silico analysis and were later confirmed experimentally by using EMSA. After addition of TBHP, NRF2 and AMPK showed a quick activation; AMPK was later down-regulated, however, while NRF2 level remained high. Autophagosome formation and Unc-51-like autophagy activating kinase 1 phosphorylation were initially stimulated, but they returned to basal values after 4 h of TBHP treatment. The silencing of NRF2 resulted in a constant activation of AMPK leading to hyperactivation of autophagy during oxidative stress. We observed the same effects in C. elegans demonstrating the conservation of this self-defense mechanism to save cells from hyperactivated autophagy upon prolonged oxidative stress. We conclude that NRF2 negatively regulates autophagy through delayed down-regulation of the expression of AMPK upon prolonged oxidative stress. This regulatory connection between NRF2 and AMPK may have an important role in understanding how autophagy is regulated in chronic human morbidities characterized by oxidative stress, such as neurodegenerative diseases, certain cancer types, and in metabolic diseases.-Kosztelnik, M., Kurucz, A., Papp, D., Jones, E., Sigmond, T., Barna, J., Traka, M. H., Lorincz, T., Szarka, A., Banhegyi, G., Vellai, T., Korcsmaros, T., Kapuy, O. Suppression of AMPK/aak-2 by NRF2/SKN-1 down-regulates autophagy during prolonged oxidative stress