651 research outputs found
THE VISIBILITY AND INVISIBILITY OF HERDERS' KRAALS IN SOUTHERN AFRICA, WITH REFERENCE TO A POSSIBLE EARLY CONTACT PERIOD KHOEKHOE KRAAL AT KFS 5, WESTERN CAPE
The Europeans who landed on the shores of the South African Cape from the late 15th century onwards encountered local herders whom they later referred to as the Hottentots (now known as the Khoekhoe). There are written references to the settlements and livestock of these pastoralists, but archaeologists have not had much success in discovering any such sites. This absence of archaeological evidence for recent Khoekhoe kraals has been interpreted by some scholars as an indication for a general archaeological invisibility of nomadic pastoralist sites. This article reports on the archaeology of an extensive, low density surface spread of artefacts, KFS 5 (Western Cape), which possibly represents a Khoekhoe kraal dating to the time of the first contact with Europeans. Data are compared to other archaeological evidence of cattle pens in southern Africa and the issues of the visibility of prehistoric and historic kraals are re-addresse
Comparison study for forced convection heat transfer of supercritical carbon dioxide flowing in a pipe
Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Forced convection heat transfer in supercritical carbon
dioxide (SCO2) was investigated experimentally in a horizontal
circular tube with an inner diameter of 8.7 mm. The experiments
were performed by varying the inlet fluid temperature, system
pressure, wall heat flux, and mass flow rate. The corresponding
Reynolds number at the inlet was between 20000 and 50000.
Nusselt number at each section in the tube was obtained to
investigate the influence of the experimental parameters on the
forced convection heat transfer in the testing tube. The obtained
heat transfer results were then compared with widely used
empirical correlations to show their prediction accuracy for the
experimental conditions tested.dc201
Polymorphism of calpastatin gene in Arabic sheep using PCR- RFLP
Calpastatin has been known as candidate gene in muscle growth efficiency and meat quality. This gene has been located to chromosome 5 of sheep. In order to evaluate the calpastatin gene polymorphism, random blood sample were collected from 111 Arabic ram sheep from different regions. The DNA extraction was based on Boom et al. (1989) method. Exon and entron I from L domain of the ovine calpastatin gene was amplified to produce a 622 bp fragment. The PCR products were electrophoresed on 1.2% agarose gel and stained by etidium bromide. Then, they were digested with restriction enzyme MspI and then electrophoresed on 2.5% agarose gel with ethidium bromide and revealed two alleles, allele A and allele B. Data were analysed using PopGene32 package. In this population, AA, AB, BB genotype have been identified with the 70.27, 28.82, 0.9% frequencies. A and B allele’s frequencies were 0.85, 0.15, respectively. The population was found to follow Hardy-Weinberg equilibrium
Evaluation of nipple aspirate fluid as a diagnostic tool for early detection of breast cancer
YesThere has been tremendous progress in detection of breast cancer in postmenopausal women, resulting in two-thirds
of women surviving more than 20 years after treatment. However, breast cancer remains the leading cause of cancerrelated
deaths in premenopausal women. Breast cancer is increasing in younger women due to changes in life-style
as well as those at high risk as carriers of mutations in high-penetrance genes. Premenopausal women with breast
cancer are more likely to be diagnosed with aggressive tumours and therefore have a lower survival rate. Mammography
plays an important role in detecting breast cancer in postmenopausal women, but is considerably less sensitive
in younger women. Imaging techniques, such as contrast-enhanced MRI improve sensitivity, but as with all imaging
approaches, cannot differentiate between benign and malignant growths. Hence, current well-established detection
methods are falling short of providing adequate safety, convenience, sensitivity and specificity for premenopausal
women on a global level, necessitating the exploration of new methods. In order to detect and prevent the disease
in high risk women as early as possible, methods that require more frequent monitoring need to be developed. The
emergence of “omics” strategies over the last 20 years, enabling the characterisation and understanding of breast cancer
at the molecular level, are providing the potential for long term, longitudinal monitoring of the disease. Tissue and
serum biomarkers for breast cancer stratification, diagnosis and predictive outcome have emerged, but have not successfully
translated into clinical screening for early detection of the disease. The use of breast-specific liquid biopsies,
such as nipple aspirate fluid (NAF), a natural secretion produced by breast epithelial cells, can be collected non-invasively
for biomarker profiling. As we move towards an age of active surveillance, home-based liquid biopsy collection
kits are increasingly being applied and these could provide a paradigm shift where NAF biomarker profiling is used for
routine breast health monitoring. The current status of established and newly emerging imaging techniques for early
detection of breast cancer and the potential for alternative biomarker screening of liquid biopsies, particularly those
applied to high-risk, premenopausal women, will be reviewed.Proteomics research was supported by Yorkshire Cancer Research projects, BPP047 and B381PA, and co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation projects ΥΓΕΙΑ/ΒΙΟΣ/0311(ΒΙΕ/07) and NEKYP/0311/17
Water-like anomalies for core-softened models of fluids: One dimension
We use a one-dimensional (1d) core-softened potential to develop a physical
picture for some of the anomalies present in liquid water. The core-softened
potential mimics the effect of hydrogen bonding. The interest in the 1d system
stems from the facts that closed-form results are possible and that the
qualitative behavior in 1d is reproduced in the liquid phase for higher
dimensions. We discuss the relation between the shape of the potential and the
density anomaly, and we study the entropy anomaly resulting from the density
anomaly. We find that certain forms of the two-step square well potential lead
to the existence at T=0 of a low-density phase favored at low pressures and of
a high-density phase favored at high pressures, and to the appearance of a
point at a positive pressure, which is the analog of the T=0 ``critical
point'' in the Ising model. The existence of point leads to anomalous
behavior of the isothermal compressibility and the isobaric specific heat
.Comment: 22 pages, 7 figure
Dispersity-Driven Melting Transition in Two Dimensional Solids
We perform extensive simulations of Lennard-Jones particles to study
the effect of particle size dispersity on the thermodynamic stability of
two-dimensional solids. We find a novel phase diagram in the dispersity-density
parameter space. We observe that for large values of the density there is a
threshold value of the size dispersity above which the solid melts to a liquid
along a line of first order phase transitions. For smaller values of density,
our results are consistent with the presence of an intermediate hexatic phase.
Further, these findings support the possibility of a multicritical point in the
dispersity-density parameter space.Comment: In revtex format, 4 pages, 6 postscript figures. Submitted to PR
Association of interleukin 1 gene cluster and interleukin 1 receptor gene polymorphisms with ischemic heart failure
BACKGROUND: Proinfl ammatory cytokines have been known to play a considerable part in the pathomechanisms of chronic heart failure (CHF). Given the importance of proinfl ammatory cytokines in the context of the failing heart, we assessed whether the polymorphisms of interleukin (IL)-1 gene cluster, including IL-1a, IL-1β, and IL-1 receptor antagonist (IL-1RA) and IL-1R gene are predictors of CHF due to ischemic heart disease. METHODS: Forty- three patients with ischemic heart failure were recruited in this study as patients group and compared with 140 healthy unrelated control subjects. Using polymerase chain reaction with sequence-specifi c primers method, the allele and genotype frequency of 5 single nucleotide polymorphisms (SNPs) within the IL- 1a (-889), IL-1β (-511, +3962), IL-1R (psti 1970), and IL-1RA (mspa1 11100) genes were determined.RESULTS: The frequency of the IL-1β -511/C allele was signifi cantly higher in the patient group compared to that in the control group (p = 0.031). The IL-1β (-511) C/C genotype was signifi cantly overrepresented in patients compared to controls (p = 0.022). CONCLUSIONS: Particular allele and genotype in IL-1β gene were overrepresented in patients with ischemic heart failure, possibly affecting the individual susceptibility to this disease (Tab. 1, Ref. 27). Text in PDF www.elis.sk
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Acceptability of Tenofovir Gel as a Vaginal Microbicide Among Women in a Phase I Trial: A Mixed-Methods Study
Objectives: In this phase I safety trial of tenofovir gel, a candidate vaginal microbicide for human immunodeficiency virus (HIV) prevention, a mixed-methods design was used to gather acceptability data among women participants. The impact of acceptability factors on use of the gel and the relationship between qualitative and quantitative acceptability data are explored.
Methods: Participants included low-risk, HIV-uninfected, and clinically stable HIV-infected women. Participants were enrolled into cohorts stratified by HIV serostatus, sexual activity, gel concentration, and frequency of use. Quantitative data were collected via interviewer-administered structured questionnaires. Qualitative data were collected via semistructured small group discussions.
Results: Although 94% of participants stated they would “probably” or “definitely” use tenofovir gel, a range of responses emerged on multiple domains relevant to microbicide acceptability during the qualitative discussions. Lubrication, leakage, sexual pleasure, and the possibility of covert use were central to women's qualitative assessments of tenofovir gel.
Conclusions: Quantitative results indicate that tenofovir vaginal gel was acceptable to almost all users, while qualitative findings indicate that acceptability is complex, varies among users, and is likely shaped by a variety of contextual factors that manufacturers will need to consider to optimize use-effectiveness. Because of the differences in the qualitative and quantitative responses, the authors argue that future trials of candidate microbicides should include strategic collection of mixed-methods microbicide acceptability data
Suppression of HBV by Tenofovir in HBV/HIV coinfected patients : a systematic review and meta-analysis
Background: Hepatitis B coinfection is common in HIV-positive individuals and as antiretroviral therapy has made death due to AIDS less common, hepatitis has become increasingly important. Several drugs are available to treat hepatitis B. The most potent and the one with the lowest risk of resistance appears to be tenofovir (TDF). However there are several questions that remain unanswered regarding the use of TDF, including the proportion of patients that achieves suppression of HBV viral load and over what time, whether suppression is durable and whether prior treatment with other HBV-active drugs such as lamivudine, compromises the efficacy of TDF due to possible selection of resistant HBV strains.
Methods: A systematic review and meta-analysis following PRISMA guidelines and using multilevel mixed effects logistic regression, stratified by prior and/or concomitant use of lamivudine and/or emtricitabine.
Results: Data was available from 23 studies including 550 HBV/HIV coinfected patients treated with TDF. Follow up was for up to seven years but to ensure sufficient power the data analyses were limited to three years. The overall proportion achieving suppression of HBV replication was 57.4%, 79.0% and 85.6% at one, two and three years, respectively. No effect of prior or concomitant 3TC/FTC was shown. Virological rebound on TDF treatment was rare.
Interpretation: TDF suppresses HBV to undetectable levels in the majority of HBV/HIV coinfected patients with the proportion fully suppressed continuing to increase during continuous treatment. Prior treatment with 3TC/FTC does not compromise efficacy of TDF treatment. The use of combination treatment with 3TC/FTC offers no significant benefit over TDF alone
Liquid State Anomalies for the Stell-Hemmer Core-Softened Potential
We study the Stell-Hemmer potential using both analytic (exact and
approximate ) solutions and numerical simulations. We observe in the
liquid phase an anomalous decrease in specific volume and isothermal
compressibility upon heating, and an anomalous increase in the diffusion
coefficient with pressure. We relate the anomalies to the existence of two
different local structures in the liquid phase. Our results are consistent with
the possibility of a low temperature/high pressure liquid-liquid phase
transition.Comment: 4 pages in one gzipped ps file including 11 figures; One RevTex and
11 gzipped eps figure
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