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Wind Energy Resource Assessment of the Caribbean and Central America
A wind energy resource assessment of the Caribbean and Central America has identified many areas with good to outstanding wind resource potential for wind turbine applications. Annual average wind resource maps and summary tables have been developed for 35 island/country areas throughout the Caribbean and Central America region. The wind resource maps highlight the locations of major resource areas and provide estimates of the wind energy resource potential for typical well-exposed sites in these areas. The average energy in the wind flowing in the layer near the ground is expressed as a wind power class: the greater the average wind energy, the higher the wind power class. The summary tables that are included with each of the 35 island/country wind energy maps provide information on the frequency distribution of the wind speeds (expressed as estimates of the Weibull shape factor, k) and seasonal variations in the wind resource for the major wind resource areas identified on the maps. A new wind power class legend has been developed for relating the wind power classes to values of mean wind power density, mean wind speed, and Weibull k. Guidelines are presented on how to adjust these values to various heights above ground for different roughness and terrain characteristics. Information evaluated in preparing the assessment included existing meteorological data from airports and other weather stations, and from ships and buoys in offshore and coastal areas. In addition, new data from recent measurement sites established for wind energy siting studies were obtained for a few areas of the Caribbean. Other types of information evaluated in the assessment were climatological data and maps on winds aloft, surface pressure, air flow, and topography. The various data were screened and evaluated for their usefulness in preparing the wind resource assessment. Much of the surface data from airports and other land-based weather stations were determined to be from sheltered sites and were thus not very useful in assessing the wind resource at locations that are well exposed to the winds. Ship data were determined to be the most useful for estimating the large-scale wind flow and assessing the spatial distribution of the wind resource throughout the region. Techniques were developed for analyzing and correcting ship wind data and extrapolating these data to coastal and inland areas by considering terrain influences on the large-scale wind flow. In areas where extrapolation of ship wind data was not entirely feasible, such as interior areas of Central America, other techniques were developed for estimating the wind flow and distribution of the wind resource. Through the application of the various innovative techniques developed for assessing the wind resource throughout the Caribbean and Central America region, many areas with potentially good to outstanding wind resource were identified that had not been previously recognized. In areas where existing site data were available from exposed locations, the measured wind resource was compared with the estimated wind resource that was derived using the assessment techniques. In most cases, there was good agreement between the measured wind resource and the estimated wind resource. This assessment project supported activities being pursued by the U.S. Committee for Renewable Energy Commerce and Trade (CORECT), the U.S. government's interagency program to assist in overseas marketing and promote renewable energy exports. An overall goal of the program is to improve U.S. competitiveness in the world renewable energy market. The Caribbean and Central America assessment, which is the first of several possible follow-on international wind energy resource assessments, provides valuable information needed by the U.S. wind energy industry to identify suitable wind resource areas and concentrate their efforts on these areas
Oral microbiota and vitamin D impact on oropharyngeal squamous cell carcinogenesis: a narrative literature review
An emerging body of research is revealing the microbiota pivotal involvement in determining the health or disease state of several human niches, and that of vitamin D also in extra-skeletal regions. Nevertheless, much of the oral microbiota and vitamin D reciprocal impact in oropharyngeal squamous cell carcinogenesis (OPSCC) is still mostly unknown.
On this premise, starting from an in-depth scientific bibliographic analysis, this narrative literature review aims to show a detailed view of the state of the art on their contribution in the pathogenesis of this cancer type.
Significant differences in the oral microbiota species quantity and quality have been detected in OPSCC affected patients; in particular, mainly high-risk human papillomaviruses (HR-HPVs), Fusobacterium nucleatum, Porphyromonas gingivalis, Pseudomonas aeruginosa and Candida spp. seem to be highly represented.
Vitamin D prevents and fights infections promoted by the above identified pathogens, thus confirming its homeostatic function on the microbiota balance. However, its antimicrobial and antitumoral actions, well-described for the gut, have not been fully documented for the oropharynx yet.
Deeper investigations of the mechanisms that link vitamin D levels, oral microbial diversity and inflammatory processes will lead to a better definition of OPSCC risk factors for the optimization of specific prevention and treatment strategies
Determining the best method for first-line assessment of neonatal blood glucose levels
Objective: To evaluate and compare the accuracy and performance of two electrochemical glucose meters. To determine the user acceptability of these glucose meters and the ABL 620 Blood Gas Analyser (Radiometer, Copenhagen, Denmark) with an electrochemical glucose oxidase electrode for use in a Level 2 special care baby unit
Interacting Spin-2 Fields
We construct consistent theories of multiple interacting spin-2 fields in
arbitrary spacetime dimensions using a vielbein formulation. We show that these
theories have the additional primary constraints needed to eliminate potential
ghosts, to all orders in the fields, and to all orders beyond any decoupling
limit. We postulate that the number of spin-2 fields interacting at a single
vertex is limited by the number of spacetime dimensions. We then show that, for
the case of two spin-2 fields, the vielbein theory is equivalent to the
recently proposed theories of ghost-free massive gravity and bi-metric gravity.
The vielbein formulation greatly simplifies the proof that these theories have
an extra primary constraint which eliminates the Boulware-Deser ghost.Comment: 42 pages, 3 figures. v3 alternative argument using constrained
spatial vielbeins has been removed (see footnote 3
The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster
The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity
Effect of time and of precursor molecule on the deposition of hydrophobic nanolayers on ethyelene tetrafluoroethylene–silicon oxide substrates
Increased risk of cancer among relatives of patients with lung cancer in China
BACKGROUND: Genetic factors were considered as one of the risk factors for lung cancer or other cancers. The aim of this work was to determine whether a genetic predisposition accounts for such familial aggregation of cancer among relatives of lung cancer probands. METHODS: A case-control study was conducted in 800 case families identified by lung cancer patients (probands), and in 800 control families identified by the probands'spouses. The data were analysed with logistic regression analysis model. RESULTS: The data revealed a significantly greater overall risk of cancer (OR = 1.82, P < 0.01) in the proband group. The relatives of lung cancer probands maintained an increased risk of non-lung cancer (P < 0.05) after adjusting for confounder factors. The crude odds ratio of a proband family having one family member with cancer was 1.67 compared with control families. Proband families were 2.56 times more likely to have two other family members with cancer. For three cancers and four or more cancers, the risk increased to 3.50 and 5.91, respectively. The most striking differences in cancer prevalence between proband and control families were noted for cancer risk among female relatives. The strongest effects were for not only lung cancer in any female relatives (OR 2.17, 95%CI 1.60–3.64) and mothers (OR 2.78, 95%CI 1.23–5.12) and sisters (OR 2.03, 95%CI 1.26–3.97), but also non-lung cancer in females and mothers (OR 2.00, 95%CI 1.26–3.01, and OR 2.34, 95%CI 1.28–4.40, respectively). CONCLUSION: These data support the hypothesis of a genetic susceptibility to cancer in families with lung cancer, and the female genetic susceptibility to cancer might be greater than male
Scattering Theory and -Symmetry
We outline a global approach to scattering theory in one dimension that
allows for the description of a large class of scattering systems and their
-, -, and -symmetries. In
particular, we review various relevant concepts such as Jost solutions,
transfer and scattering matrices, reciprocity principle, unidirectional
reflection and invisibility, and spectral singularities. We discuss in some
detail the mathematical conditions that imply or forbid reciprocal
transmission, reciprocal reflection, and the presence of spectral singularities
and their time-reversal. We also derive generalized unitarity relations for
time-reversal-invariant and -symmetric scattering
systems, and explore the consequences of breaking them. The results reported
here apply to the scattering systems defined by a real or complex local
potential as well as those determined by energy-dependent potentials, nonlocal
potentials, and general point interactions.Comment: Slightly expanded revised version, 38 page
Can We Really Prevent Suicide?
Every year, suicide is among the top 20 leading causes of death globally for all ages. Unfortunately, suicide is difficult to prevent, in large part because the prevalence of risk factors is high among the general population. In this review, clinical and psychological risk factors are examined and methods for suicide prevention are discussed. Prevention strategies found to be effective in suicide prevention
include means restriction, responsible media coverage, and general public education, as well identification methods such as screening, gatekeeper training, and primary care physician education. Although the treatment for preventing suicide is difficult, follow-up that includes pharmacotherapy, psychotherapy, or both may be useful. However, prevention methods cannot be restricted to the individual. Community, social, and policy interventions will also be essentia
Excitotoxic cell death induces delayed proliferation of endogenous neuroprogenitor cells in organotypic slice cultures of the rat spinal cord
The aim of the present report was to investigate whether, in the mammalian spinal cord, cell death induced by transient excitotoxic stress could trigger activation and proliferation of endogenous neuroprogenitor cells as a potential source of a lesion repair process and the underlying time course. Because it is difficult to address these issues in vivo, we used a validated model of spinal injury based on rat organotypic slice cultures that retain the fundamental tissue cytoarchitecture and replicate the main characteristics of experimental damage to the whole spinal cord. Excitotoxicity evoked by 1 h kainate application produced delayed neuronal death (40%) peaking after 1 day without further losses or destruction of white matter cells for up to 2 weeks. After 10 days, cultures released a significantly larger concentration of endogenous glutamate, suggesting functional network plasticity. Indeed, after 1 week the total number of cells had returned to untreated control level, indicating substantial cell proliferation. Activation of progenitor cells started early as they spread outside the central area, and persisted for 2 weeks. Although expression of the neuronal progenitor phenotype was observed at day 3, peaked at 1 week and tapered off at 2 weeks, very few cells matured to neurons. Astroglia precursors started proliferating later and matured at 2 weeks. These data show insult-related proliferation of endogenous spinal neuroprogenitors over a relatively brief time course, and delineate a narrow temporal window for future experimental attempts to drive neuronal maturation and for identifying the factors regulating this process. \ua9 2013 Macmillan Publishers Limited. All rights reserved
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