120 research outputs found
A review of very short-term wind and solar power forecasting
Installed capacities of wind and solar power have grown rapidly over recent years, and the pool of literature on very short-term (minutes- to hours-ahead) wind and solar forecasting has grown in line with this. This paper reviews established and emerging approaches to provide an up-to-date view of the field. Knowledge transfer between wind and solar forecasting has benefited the field and is discussed, and new opportunities are identified, particularly regarding use of remote sensing technology. Forecasting methodologies and study design are compared and recommendations for high quality, reproducible results are presented. In particular, the choice of suitable benchmarks and use of sufficiently long datasets is highlighted. A case study of three distinct approaches to probabilistic wind power forecasting is presented using an open dataset. The case study provides an example of exemplary forecast evaluation, and open source code allows for its reproduction and use in future work
The SKA Particle Array Prototype: The First Particle Detector at the Murchison Radio-astronomy Observatory
We report on the design, deployment, and first results from a scintillation
detector deployed at the Murchison Radio-astronomy Observatory (MRO). The
detector is a prototype for a larger array -- the Square Kilometre Array
Particle Array (SKAPA) -- planned to allow the radio-detection of cosmic rays
with the Murchison Widefield Array and the low-frequency component of the
Square Kilometre Array. The prototype design has been driven by stringent
limits on radio emissions at the MRO, and to ensure survivability in a desert
environment. Using data taken from Nov.\ 2018 to Feb.\ 2019, we characterize
the detector response while accounting for the effects of temperature
fluctuations, and calibrate the sensitivity of the prototype detector to
through-going muons. This verifies the feasibility of cosmic ray detection at
the MRO. We then estimate the required parameters of a planned array of eight
such detectors to be used to trigger radio observations by the Murchison
Widefield Array.Comment: 17 pages, 14 figures, 3 table
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Chromosome aberrations in lymphocytes of workers occupationally exposed to ionising radiation
Cytogenetic studies on workers employed at the Sellafield nuclear installation are reviewed and their relevance discussed in relation to biological dosimetry and risk assessment
Microsatellite polymorphisms in DNA repair genes XRCC1, XRCC3 and XRCC5 in patients with gynecological tumors: Association with late clinical radiosensitivity and cancer incidence
This study investigates the association of microsatellite polymorphisms in XRCC1, XRCC3 and XRCC5 with the development of late radiation-induced radiotherapy reactions and examines the correlation between these microsatellites and cancer incidence. Sixty-two women with cervical or endometrial cancer treated with radiotherapy were included in the study. According to the CTCAEv3.0 scale, 22 patients showed late adverse radiotherapy reactions (grade 2 or more). PCR on lymphocyte DNA followed by automated fragment analysis was performed to examine the number of tandem repeat units at each locus. No significant association was found between the repeat length at any of the microsatellites in XRCC1, XRCC3 or XRCC5 and the incidence of late radiotherapy complications. Since higher odds ratios (ORs) were found for the rare XRCC1 [AC]11 and [AC]21 repeats (OR = 2.65, P = 0.325 and OR = 8.67, P = 0.093, respectively), the possible involvement of these small and large repeats in clinical radiosensitivity cannot be completely ruled out. When specific numbers of repeats were examined, no significant correlation was found between the microsatellite repeat length in XRCC1 and XRCC5 and cancer incidence. A weak correlation between XRCC3 [AC]16 homozygotes and cancer incidence was found (OR = 2.56, P = 0.055). A large-scale multicenter study of cancer patients with a high number of radiosensitive individuals is needed to clarify the value of rare polymorphic microsatellite repeats in XRCC1 and XRCC3 as a biomarker of clinical radiosensitivity or increased cancer risk
Exploring variations in childhood stunting in Nigeria using league table, control chart and spatial analysis
Background: Stunting, linear growth retardation is the best measure of child health inequalities as it captures multiple dimensions of children’s health, development and environment where they live. The developmental priorities and socially acceptable health norms and practices in various regions and states within Nigeria remains disaggregated and with this, comes the challenge of being able to ascertain which of the regions and states identifies with either high or low childhood stunting to further investigate the risk factors and make recommendations for action oriented policy decisions.
Methods: We used data from the birth histories included in the 2008 Nigeria Demographic and Health Survey (DHS) to estimate childhood stunting. Stunting was defined as height for age below minus two standard deviations from the median height for age of the standard World Health Organization reference population. We plotted control charts of the proportion of childhood stunting for the 37 states (including federal capital, Abuja) in Nigeria. The Local Indicators of Spatial Association (LISA) were used as a measure of the overall clustering and is assessed by a test of a null hypothesis.
Results: Childhood stunting is high in Nigeria with an average of about 39%. The percentage of children with stunting ranged from 11.5% in Anambra state to as high as 60% in Kebbi State. Ranking of states with respect to childhood stunting is as follows: Anambra and Lagos states had the least numbers with 11.5% and 16.8% respectively while Yobe, Zamfara, Katsina, Plateau and Kebbi had the highest (with more than 50% of their underfives having stunted growth).
Conclusions: Childhood stunting is high in Nigeria and varied significantly across the states. The northern states have a higher proportion than the southern states. There is an urgent need for studies to explore factors that may be responsible for these special cause variations in childhood stunting in Nigeria
Intermediate Tail Dependence: A Review and Some New Results
The concept of intermediate tail dependence is useful if one wants to
quantify the degree of positive dependence in the tails when there is no strong
evidence of presence of the usual tail dependence. We first review existing
studies on intermediate tail dependence, and then we report new results to
supplement the review. Intermediate tail dependence for elliptical, extreme
value and Archimedean copulas are reviewed and further studied, respectively.
For Archimedean copulas, we not only consider the frailty model but also the
recently studied scale mixture model; for the latter, conditions leading to
upper intermediate tail dependence are presented, and it provides a useful way
to simulate copulas with desirable intermediate tail dependence structures.Comment: 25 pages, 1 figur
Lymphocytes of Type 2 Diabetic Women Carry a High Load of Stable Chromosomal Aberrations : A Novel Risk Factor for Disease-Related Early Death
OBJECTIVE—Diabetes is associated with an increased risk of death in women. Oxidative stress due to chronic hyperglycemia leads to the generation of reactive oxygen species and loss of chromosomal integrity. To clarify whether diabetes is a premature aging syndrome, we determined telomere erosion dynamics and occurrence of structural chromosomal aberrations in women of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study
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