746 research outputs found
The Archaeology Of Gua Tupak From 1,190 B.P. To 170 B.P. In Bau, Sarawak
No full textIn November and December 2007, an archaeological survey was conducted
by the author and a research team from the Centre for Global Archaeological
Research, Universiti Sains Malaysia, Penang with the cooperation of the Sarawak
Museum Department, Kuching in the limestone caves of the Bau area, southwest
Sarawak in order to search for a site for the author’s Master of Arts (MA) study. The
result of the survey determined Gua Tupak to be a highly potential site and
consequently, excavations were carried out at the site in February and March 2008.
The excavations at Gua Tupak yielded valuable archaeological data that could aid in
providing information on the prehistory of the site and the Bau area. The
archaeological data include various types of artefacts such as shell remains, animal
bones, ceramic sherds and stone artefacts. In addition, charcoal and shell samples
were collected for radiocarbon dating, soil samples were collected for palynological
analysis and soil profiles of the excavated trenches were recorded. Results of the
analyses of artefacts and interpretations of the archaeological data recovered from
Gua Tupak suggest that the site was used as a temporary habitation site or shelter
with two main phases of occupation; the Early Phase with a radiocarbon date of
around 1,190 ± 40 B.P., and the Late Phase with radiocarbon dates ranging from 270
± 50 B.P. to 170 ± 40 B.P
Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.
No full textOur understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene
Whole body heat exposure induces apoptosis in mouse caudal epididymal spermatozoa
No full textPaper 115, Abstracts only published 40th Annual Conference of the Society for Reproductive Biology
Introduction: The aim of the present study was to determine the immediate effects of whole body heating on sperm numbers, motility and apoptosis. Material and Methods: C57BL/6 mice (n=7) were exposed to 37-38oC (8 hours/day), for three consecutive days while control mice (n=7) were kept at 23-24oC. Caudal epididymal spermatozoa were collected from control and heat treated mice 16 hours after the last heat treatment to determine the sperm number and motility using a Neubauer haemocytometer and sperm apoptotic changes by dual colorflow cytometry using Annexin V/PE (Annexin V conjugated with phycoerythrin) and 7AAD (7-amino-actinomycin D) stains. Results: There were no significant differences (p>0.05) in sperm numbers between heat treated and control mice, however heating did result in a significant reduction in sperm motility (p<0.05). Apoptosis staining identified four different subpopulations of spermatozoa: (a) live spermatozoa (Annexin V-/7AAD-), (b) early apoptotic spermatozoa with exteriorized phosphotidylserine (PS) receptor and intact plasmalemma (Annexin V+/7AAD-), (c) late apoptotic spermatozoa with PS receptor translocation and leaky plasmalemma (Annexin V+/7AAD+) and (d) dead spermatozoa with damaged plasmalemma with no detectable PS receptor (Annexin V-/7AAD+). Heating resulted in significant reduction in the percentage of live spermatozoa (p<0.05), an increase in early apoptotic (p<0.05), late apoptotic (p<0.05), and dead spermatozoa (p<0.05). Conclusion: This study shows that mice exposed to whole body heat exposure of 37-38oC for 8 hours per day for three consecutive days exhibited early and late apoptotic changes to epididymal spermatozoa. These findings suggest possible adverse effects of exposure to high temperature on the viability of human spermatozoa in the epididymides. In addition, these findings reinforce the importance of temperature during sperm preparation procedures in infertility clinics, and research laboratories.
H. Wechalekar, B.P. Setchell, W. G. Breed, M. Ricci, C. Leigh and E. Peirc
Predictive mechanical model for fracture stimulation in an enhanced geothermal system (EGS) context
No full textAccepted Author ManuscriptReservoir EngineeringApplied Geolog
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