287 research outputs found

    Global Warming: A Critique of the Anthropogenic Model and its Consequences

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    According to popular belief, recent global warming has been caused largely by greenhouse gases, primarily CO2, accruing in the atmosphere, and man is responsible for most of the ~120 ppm increase in CO2 over the last 100 years. This article cites a number of recent peer-reviewed scientific papers, and finds that contrary arguments by a growing body of scientists are generally supported by better empirical data than those that favour the ‘anthropogenic warming’ hypothesis. These arguments invoke the effects of solar irradiance and ocean–atmosphere interactions, both of which have been shown to have warming effects at least as great as those claimed for CO2, and to be based on sound, well-understood scientific theory. Furthermore, the global warming models used by the Intergovernmental Panel on Climate Change (IPCC) and others have in some cases been shown to be incorrect and contrary to current temperature statistics. For these and other reasons, the CO2-driven, anthropogenic warming hypothesis is regarded by many as suspect and lacking in empirical evidence. The difficulty of refuting this popular hypothesis is exacerbated by the IPCC’s United Nations mandate to advise governments on the severity of man-made global warming, a mandate that they have followed faithfully, encouraging the emergence of a large body of funded research that supports their view. This presents a problem for global society, as the human-caused warming scenario diverts attention from other, at least equally serious environmental impacts of our industrial society. Recently, however, there appears to be a tilting of public opinion away from global warming alarmism, which may fundamentally affect the direction of the climate change debate. Sommaire Selon la croyance populaire, le rĂ©chauffement climatique actuel aurait Ă©tĂ© causĂ© en grande partie par des gaz Ă  effet de serre, principalement le CO2 s’accumulant dans l'atmosphĂšre et, c’est l'homme qui serait Ă  l’origine de l’augmentation de ~ 120 ppm de la teneur en CO2 au cours du dernier siĂšcle. Dans le prĂ©sent article on cite un certain nombre d’articles scientifiques Ă  comitĂ© de lecture, et on conclut que des arguments contraires prĂ©sentĂ©s par un nombre croissant de scientifiques, sont gĂ©nĂ©ralement soutenus par de meilleures donnĂ©es empiriques que celles qui favorisent l’hypothĂšse d’un « rĂ©chauffement anthropogĂ©nique ». À partir d’une thĂ©orie scientifique bien fondĂ©e, ces arguments montrent que les effets du rayonnement solaire et des interactions ocĂ©an-atmosphĂšre ont un effet climatique de rĂ©chauffement au moins aussi important que celui imputĂ© au CO2. En outre, il a Ă©tĂ© dĂ©montrĂ© que les modĂšles de rĂ©chauffement de la planĂšte utilisĂ©s par le Groupe d'experts intergouvernemental sur les changements climatiques (GIEC) et d'autres sont, dans certains cas avĂ©rĂ©s erronĂ©s et en contradiction avec les statistiques actuelles sur la tempĂ©rature. Pour ces raisons et d'autres, nombreux sont ceux qui considĂšrent que l’hypothĂšse d’un rĂ©chauffement climatique anthropogĂ©nique par le CO2 est sujette Ă  caution et manque de preuves empiriques. À noter qu’il est d’autant plus difficile de rĂ©futer cette hypothĂšse populaire que l’Organisation des Nations Unies a confiĂ© au GIEC le mandat de conseiller les gouvernements sur la gravitĂ© du rĂ©chauffement climatique anthropogĂ©nique, mandat dont il s’acquitte avec application, ce qui favorise l'Ă©mergence d'un important volume de recherches financĂ©es, qui tendent Ă  confirmer leur point de vue. Cela pose un problĂšme pour l’humanitĂ© entiĂšre, en ce que le scĂ©nario d’un rĂ©chauffement climatique anthropogĂ©nique dĂ©tourne l'attention d’autres problĂšmes de notre sociĂ©tĂ© industriel qui ont des rĂ©percussions au moins aussi graves sur l'environnement. RĂ©cemment, cependant, il semble y avoir un basculement de l'opinion publique qui tend Ă  remettre en question l'alarmisme ambiant sur le rĂ©chauffement climatique planĂ©taire, ce qui pourrait affecter fondamentalement le sens du dĂ©bat sur le changement climatique

    Genetic programming with context-sensitive grammars

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    This thesis presents Genetic Algorithm for Deriving Software (Gads), a new technique for genetic programming. Gads combines a conventional genetic algorithm with a context-sensitive grammar. The key to Gads is the onto genic mapping, which converts a genome from an array of integers to a correctly typed program in the phenotype language defined by the grammar. A new type of grammar, the reflective attribute grammar (rag), is introduced. The rag is an extension of the conventional attribute grammar, which is designed to produce valid sentences, not to recognize or parse them. Together, Gads and rags provide a scalable solution for evolving type-correct software in independently-chosen context-sensitive languages. The statistics of performance comparison is investigated. A method for representing a set of genetic programming systems or problems on a cladogram is presented. A method for comparing genetic programming systems or problems on a single rational scale is proposed

    Characterization of optically driven fluid stress fields with optical tweezers

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    We present a controlled stress microviscometer with applications to complex fluids. It generates and measures microscopic fluid velocity fields, based on dual beam optical tweezers. This allows an investigation of bulk viscous properties and local inhomogeneities at the probe particle surface. The accuracy of the method is demonstrated in water. In a complex fluid model (hyaluronic acid), we observe a strong deviation of the flow field from classical behavior. Knowledge of the deviation together with an optical torque measurement is used to determine the bulk viscosity. Furthermore, we model the observed deviation and derive microscopic parameters

    Optical application and measurement of torque on microparticles of isotropic nonabsorbing material

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    We show how it is possible to controllably rotate or align microscopic particles of isotropic nonabsorbing material in a TEM00 Gaussian beam trap, with simultaneous measurement of the applied torque using purely optical means. This is a simple and general method of rotation, requiring only that the particle is elongated along one direction. Thus, this method can be used to rotate or align a wide range of naturally occurring particles. The ability to measure the applied torque enables the use of this method as a quantitative tool--the rotational equivalent of optical tweezers based force measurement. As well as being of particular value for the rotation of biological specimens, this method is also suitable for the development of optically-driven micromachines.Comment: 8 pages, 6 figure

    Intimate partner violence among pregnant women in Rwanda

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    <p>Abstract</p> <p>Background</p> <p>Intimate partner violence (IPV), defined as actual or threatened physical, sexual, psychological, and emotional abuse by current or former partners is a global public health concern. The prevalence and determinants of intimate partner violence (IPV) against pregnant women has not been described in Rwanda. A study was conducted to identify variables associated with IPV among Rwandan pregnant women.</p> <p>Methods</p> <p>A convenient sample of 600 pregnant women attending antenatal clinics were administered a questionnaire which included items on demographics, HIV status, IPV, and alcohol use by the male partner. Mean age and proportions of IPV in different groups were assessed. Odds of IPV were estimated using logistic regression analysis.</p> <p>Results</p> <p>Of the 600 respondents, 35.1% reported IPV in the last 12 months. HIV+ pregnant women had higher rates of all forms of IVP violence than HIV- pregnant women: pulling hair (44.3% vs. 20.3%), slapping (32.0% vs. 15.3%), kicking with fists (36.3% vs. 19.7%), throwing to the ground and kicking with feet (23.3% vs. 12.7%), and burning with hot liquid (4.1% vs. 3.5%). HIV positive participants were more than twice likely to report physical IPV than those who were HIV negative (OR = 2.38; 95% CI [1.59, 3.57]). Other factors positively associated with physical IPV included sexual abuse before the age of 14 years (OR = 2.69; 95% CI [1.69, 4.29]), having an alcohol drinking male partner (OR = 4.10; 95% CI [2.48, 6.77] for occasional drinkers and OR = 3.37; 95% CI [2.05, 5.54] for heavy drinkers), and having a male partner with other sexual partners (OR = 1.53; 95% CI [1.15, 2.20]. Education was negatively associated with lifetime IPV.</p> <p>Conclusion</p> <p>We have reported on prevalence of IPV violence among pregnant women attending antenatal care in Rwanda, Central Africa. We advocate that screening for IPV be an integral part of HIV and AIDS care, as well as routine antenatal care. Services for battered women should also be made available.</p

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Distinct differences in the nanoscale behaviors of the twist-bend liquid crystal phase of a flexible linear trimer and homologous dimer

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    This work was supported by National Science Foundation Materials Research Science and Engineering Center Grant DMR-1420736 and Grant DMR-1307674. M.R.T. acknowledges support from the Advanced Light Source Doctoral Fellowship in Residence offered by Lawrence Berkeley National Laboratory. M.S. acknowledges the support of the US National Science Foundation I2CAM International Materials Institute Award, Grant DMR-1411344. We acknowledge use of beamlines 11.0.1.2 and 7.3.3. of the Advanced Light Source supported by the Director of the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract DE-AC02-05CH11231.Peer reviewedPublisher PD

    Identifying outcome-based indicators and developing a curriculum for a continuing medical education programme on rational prescribing using a modified Delphi process

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    <p>Abstract</p> <p/> <p>Background</p> <p>Continuing medical education (CME) is compulsory for physicians in Iran. Recent studies in Iran show that modifications of CME elements are necessary to improve the effectiveness of the educational programmes. Other studies point to an inappropriate, even irrational drug prescribing. Based on a needs assessment study regarding CME for general physicians in the East Azerbaijan province in Iran, rational prescribing practice was recognized as a high priority issue. Considering different educational methods, outcome-based education has been proposed as a suitable approach for CME. The purpose of the study was to obtain experts' consensus about appropriate educational outcomes of rational prescribing for general physicians in CME and developing curricular contents for this education.</p> <p>Methods</p> <p>The study consisted of two phases: The first phase was conducted using a two-round Delphi consensus process to identify the outcome-based educational indicators regarding rational prescribing for general physicians in primary care (GPs). In the second phase the agreed indicators were submitted to panels of experts for assessment and determination of content for a CME program in the field.</p> <p>Results</p> <p>Twenty one learning outcomes were identified through a modified Delphi process. The indicators were used by the panels of experts and six educational topics were determined for the CME programme and the curricular content of each was defined. The topics were 1) Principles of prescription writing, 2) Adverse drug reactions, 3) Drug interactions, 4) Injections, 5) Antibiotic therapy, and 6) Anti-inflammatory agents therapy. One of the topics was not directly related to any outcome, raising a question about the need for a discussion on constructive alignment.</p> <p>Conclusions</p> <p/> <p>Consensus on learning outcomes was achieved and an educational guideline was designed. Before suggesting widespread use in the country the educational package should be tested in the CME context.</p

    Real-time PCR complements immunohistochemistry in the determination of HER-2/neu status in breast cancer

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    BACKGROUND: The clinical benefit of determining the status of HER-2/neu amplification in breast cancer patients is well accepted. Although immunohistochemistry (IHC) is the most frequently used method to assess the over-expression of HER-2 protein, fluorescent in-situ hybridization (FISH) is recognized as the "gold standard" for the determining of HER-2/neu status. The greatest discordance between the two methods occurs among breast tumors that receive an indeterminate IHC score of 2+. More recently, a real-time polymerase chain reaction (PCR) assay using the LightCycler(Âź )has been developed for quantifying HER-2/neu gene amplification. In this study, we evaluated the sensitivity and specificity of a commercially available LightCycler assay as it compares to FISH. To determine whether this assay provides an accurate alternative for the determination of HER-2/neu status, we focused primarily on tumors that were deemed indeterminate or borderline status by IHC. METHODS: Thirty-nine breast tumors receiving an IHC score of 2+ were evaluated by both FISH and LightCycler(Âź )technologies in order to determine whether quantitative real-time PCR provides an accurate alternative for the determination of HER-2/neu status. RESULTS: We found a high concordance (92%) between FISH and real-time PCR results. We also observed that 10% of these tumors were positive for gene amplification by both FISH and real-time PCR. CONCLUSION: The data show that the results obtained for the gene amplification of HER-2/neu by real-time PCR on the LightCycler(Âź )instrument is comparable to results obtained by FISH. These results therefore suggest that real-time PCR analysis, using the LightCycler(Âź), is a viable alternative to FISH for reassessing breast tumors which receive an IHC score of 2+, and that a combined IHC and real-time PCR approach for the determination of HER-2 status in breast cancer patients may be an effective and efficient strategy

    Landscape structure affects the prevalence and distribution of a tick-borne zoonotic pathogen

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    Background Landscape structure can affect pathogen prevalence and persistence with consequences for human and animal health. Few studies have examined how reservoir host species traits may interact with landscape structure to alter pathogen communities and dynamics. Using a landscape of islands and mainland sites we investigated how natural landscape fragmentation affects the prevalence and persistence of the zoonotic tick-borne pathogen complex Borrelia burgdorferi(sensu lato), which causes Lyme borreliosis. We hypothesized that the prevalence of B. burgdorferi (s.l.) would be lower on islands compared to the mainland and B. afzelii, a small mammal specialist genospecies, would be more affected by isolation than bird-associated B. garinii and B. valaisiana and the generalist B. burgdorferi (sensu stricto). Methods Questing (host-seeking) nymphal I. Ricinus ticks (n = 6567) were collected from 12 island and 6 mainland sites in 2011, 2013 and 2015 and tested for B. burgdorferi(s.l.). Deer abundance was estimated using dung transects. Results The prevalence of B. burgdorferi (s.l.) was significantly higher on the mainland (2.5%, 47/1891) compared to island sites (0.9%, 44/4673) (P &lt; 0.01). While all four genospecies of B. burgdorferi (s.l.) were detected on the mainland, bird-associated species B. garinii and B. valaisiana and the generalist genospecies B. burgdorferi(s.s.) predominated on islands. Conclusion We found that landscape structure influenced the prevalence of a zoonotic pathogen, with a lower prevalence detected among island sites compared to the mainland. This was mainly due to the significantly lower prevalence of small mammal-associated B. afzelii. Deer abundance was not related to pathogen prevalence, suggesting that the structure and dynamics of the reservoir host community underpins the observed prevalence patterns, with the higher mobility of bird hosts compared to small mammal hosts leading to a relative predominance of the bird-associated genospecies B. garinii and generalist genospecies B. burgdorferi (s.s.) on islands. In contrast, the lower prevalence of B. afzelii on islands may be due to small mammal populations there exhibiting lower densities, less immigration and stronger population fluctuations. This study suggests that landscape fragmentation can influence the prevalence of a zoonotic pathogen, dependent on the biology of the reservoir host
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