Faculty of Natural Sciences: Recent submissions
Now showing items 2321-2340 of 2527
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HE0230–4323: an unusual pulsating hot subdwarf star
(Oxford University Press, 2007)HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not observable in the optical. Photometric measurements reported in this paper have shown it to be both a reflection-effect and a ... -
The Nyquist frequency for time series with slight deviations from regular spacing
(Oxford University Press, 2009)The paper is based on the notion that the Nyquist frequency νN is a symmetry point of the periodogram of a time series: the power spectrum at frequencies above νN is a mirror image of that below νN. Koen showed that the ... -
Fitting power-law distributions to data with measurement errors
(Oxford University Press, 2009)If X, which follows a power-law distribution, is observed subject to Gaussian measurement error e, thenX+e is distributed as the convolution of the power-lawand Gaussian distributions. Maximum-likelihood estimation of ... -
The analysis of indexed astronomical time series – X. Significance testing of O − C data
(Oxford University Press, 2006)It is assumed that O − C (‘observed minus calculated’) values of periodic variable stars are determined by three processes, namely measurement errors, random cycle-to-cycle jitter in the period, and possibly long-term ... -
Estimation of the coherence time of stochastic oscillations from modest samples
(Oxford University Press, 2012)‘Quasi-periodic’ or ‘solar-like’ oscillations can be described by three parameters – a characteristic frequency, a coherence time (or ‘quality factor’) and the variance of the random driving process. This paper is concerned ... -
Photometry of the magnetic white dwarf SDSS 121209.31+013627.7
(Oxford University Press, 2006)The results of 27 h of time series photometry of SDSS 121209.31+013627.7 are presented. The binary period established from spectroscopy is confirmed and refined to 0.061 412 d (88.43 min). The photometric variations are ... -
The analysis of irregularly observed stochastic astronomical time-series – I. Basics of linear stochastic differential equations
(Oxford University Press, 2005)The theory of low-order linear stochastic differential equations is reviewed. Solutions to these equations give the continuous time analogues of discrete time autoregressive time-series. Explicit forms for the power ... -
Improved SAAO–2MASS photometry transformations
(Oxford University Press, 2007)Near-infrared photometry of 599 stars is used to calculate transformations from the South African Astronomical Observatory (SAAO) JHK system to the Two-Micron All-Sky Survey (2MASS) JHKS system. Both several-term formal ... -
Detection of an increasing orbital period in the subdwarf B eclipsing system NSVS 14256825
(Oxford University Press, 2012)New timings of eclipses made in 2010 and 2011 are presented for the hot subdwarf B (sdB) eclipsing binary NSVS 14256825. Composed of an sdB star and a much cooler companion, with a period near 0.1104 days, this system ... -
Human coronavirus NL63 open reading frame 3 encodes a virion-incorporated N-glycosylated membrane protein
(BioMed Central, 2010)Background: Human pathogenic coronavirus NL63 (hCoV-NL63) is a group 1 (alpha) coronavirus commonly associated with respiratory tract infections. In addition to known non-structural and structural proteins all coronaviruses ... -
Over-expression of severe acute respiratory syndrome coronavirus 3b protein induces both apoptosis and necrosis in Vero E6 cells
(Elsevier, 2006)The genome of the severe acute respiratory syndrome coronavirus encodes for eight accessory viral proteins with no known homologues in other coronaviruses. One of these is the 3b protein, which is encoded by the second ... -
The Severe Acute Respiratory Syndrome Coronavirus 3a Protein Up-Regulates Expression of Fibrinogen in Lung Epithelial Cells
(American Society for Microbiology, 2005)Here we analyzed the gene expression profile of cells that stably express the severe acute respiratory syndrome coronavirus (SARS-CoV) 3a protein to determine its effects on host functions. A lung epithelial cell-line, ... -
Severe acute respiratory syndrome coronavirus protein 7a interacts with hSGT
(Elsevier, 2006)Severe acute respiratory syndrome coronavirus (SARS-CoV) 7a is an accessory protein with no known homologues. In this study, we report the interaction of a SARS-CoV 7a and small glutamine-rich tetratricopeptide repeat-containing ... -
Profiles of antibody responses against severe acute respiratory syndrome coronavirus recombinant proteins and their potential use as diagnostic markers
(American Society for Microbiology, 2004) -
The characterization and phylogenetic relationship of the trichoplusia ni single capsid nuclear polyhedrosis virus polyhedrin gene
(Kluwer Academic Publishers, 1999)The polyhedrin gene (polh) was identified from the Trichoplusia ni (Tni) single capsid nuclear polyhedrosis virus (SNPV). An EcoRI fragment containing the truncated polyhedrin gene was detected by hybridization with an ... -
Identification, sequence analysis, and phylogeny of the immediate early gene 1 of the trichoplusia ni single nucleocapsid polyhedrosis virus
(Springer Verlag, 2001)Substantial research has been conducted on the immediate early 1 (ie-1) genes from the prototype baculovirus Autographa californica multicapsid nuclear polyhedrosis virus (AcMNPV) and the Orgyia pseudotsugata multicapsid ... -
Conservation status of large branchiopods in the Western Cape, South Africa
(Springer Verlag, 2007)Temporary wetlands are an ecologically and economically important habitat in South Africa. They harbor large branchiopods, known to be flagship species of nonpermanent aquatic habitats, and sensitive to land use changes. ... -
The variable N-terminal region of DDX5 contains structural elements and auto-inhibits its interaction with NS5B of hepatitis C virus
(Portland Press, 2012)RNA helicases of the DEAD (Asp-Glu-Ala-Asp)-box family of proteins are involved in many aspects of RNA metabolism from transcription to RNA decay, but most of them have also been shown to be multifunctional. The DEAD-box ... -
Vulnerable diseases affecting child mortality in Sierra Leone: emerging health issue
(SAGE Publications, 2012)Child mortality in Sierra Leone is the highest ranked in the world. The main causes for child mortality are maternal factors, environmental factors and health factors. Minimal research has been carried out on health factors ... -
Mental health services in Ethiopia: emerging public health
(WB Saunders, 2011)Summary: Objectives: Examine the mental health issues in Ethiopia in relation to services offered in this direction. Study Design: Retrospective. Methods: Results of the 2005 Ethiopian Demographic and Health Survey and ...