899 resultados para One Step dentin bonding system
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This paper analyzes the potential of one-step transfer prices based on either variable or full costs for coordinating decentralized production and quality-improving investment decisions. Transfer prices based on variable costs fail to induce investments on the upstream stage. In contrast, transfer prices based on full costs provide strong investment incentives for the upstream divisions. However, they fail to coordinate the investment decisions. We show that negotiations prevent such coordination failure. In particular, we find that the firm benefits from a higher degree of decentralization so that total profit increases in the number of parameters being subject to negotiations.
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In the present study, the prevalence of S. aureus in mammary gland quarters of dairy cows in Switzerland was estimated and a risk factor analysis was carried out. Dairy cows were selected by one-step-cluster sampling with stratification by herd size. Forty-seven of 50 randomly chosen farms participated in the study, resulting in 603 cows and 2388 quarter samples. Milk samples were collected in all herds on two occasions two weeks apart. In 6% of cows (95% CI: 2.7-9.3%) at least one milk sample was positive for S. aureus and from 2% (0.8-3.2%) of all quarters, S. aureus was cultured at least once. In four quarters a latent S. aureus infection (agent detected and somatic cell count (SCC) <100,000cell/ml) was diagnosed. Multivariable hierarchic logistical regression analysis yielded five significant risk factors for observing S. aureus in a milk sample: high SCC, a S. aureus-positive neighbouring quarter, a palpable induration in the quarter, and a wound, scar tissue or crush injury affecting the teat. The type of housing (P=0.1596) was also a factor that remained in the model. The mentioned risk factors must be considered during the evaluation of herds with S. aureus problems. The occurrence of latent S. aureus infections emphasises that not only quarters with a high SCC but all quarters of all cows must be cultured for control measures to be effective.
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Recent improvements in precursor chemistry, reactor geometry and run conditions extend the manufacturing capability of traditional flame aerosol synthesis of oxide nanoparticles to metals, alloys and inorganic complex salts. As an example of a demanding composition, we demonstrate here the one-step flame synthesis of nanoparticles of a 4-element non-oxide phosphor for upconversion applications. The phosphors are characterized in terms of emission capability, phase purity and thermal phase evolution. The preparation of flame-made beta-NaYF4 with dopants of Yb, Tm or Yb, Er furthermore illustrates the now available nanoparticle synthesis tool boxes based on modified flamespray synthesis from our laboratories at ETH Zurich. Since scaling concepts for flame synthesis, including large-scale filtration and powder handling, have become available commercially, the development of industrial applications of complex nanoparticles of metals, alloys or most other thermally stable, inorganic compounds can now be considered a feasible alternative to traditional top-down manufacturing or liquid-intense wet chemistry.
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In the field of thrombosis and haemostasis, many preanalytical variables influence the results of coagulation assays and measures to limit potential results variations should be taken. To our knowledge, no paper describing the development and maintenance of a haemostasis biobank has been previously published. Our description of the biobank of the Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+) is intended to facilitate the set-up of other biobanks in the field of thrombosis and haemostasis. SWITCO65+ is a multicentre cohort that prospectively enrolled consecutive patients aged ≥65 years with venous thromboembolism at nine Swiss hospitals from 09/2009 to 03/2012. Patients will be followed up until December 2013. The cohort includes a biobank with biological material from each participant taken at baseline and after 12 months of follow-up. Whole blood from all participants is assayed with a standard haematology panel, for which fresh samples are required. Two buffy coat vials, one PAXgene Blood RNA System tube and one EDTA-whole blood sample are also collected at baseline for RNA/DNA extraction. Blood samples are processed and vialed within 1 h of collection and transported in batches to a central laboratory where they are stored in ultra-low temperature archives. All analyses of the same type are performed in the same laboratory in batches. Using multiple core laboratories increased the speed of sample analyses and reduced storage time. After recruiting, processing and analyzing the blood of more than 1,000 patients, we determined that the adopted methods and technologies were fit-for-purpose and robust.
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I studied the apolipoprotein (apo) B 3$\sp\prime$ variable number tandem repeat (VNTR) and did computer simulations of the stepwise mutation model to address four questions: (1) How did the apo B VNTR originate? (2) What is the mutational mechanism of repeat number change at the apo B VNTR? (3) To what extent are population and molecular level events responsible for the determination of the contemporary apo B allele frequency distribution? (4) Can VNTR allele frequency distributions be explained by a simple and conservative mutation-drift model? I used three general approaches to address these questions: (1) I characterized the apo B VNTR region in non-human primate species; (2) I constructed haplotypes of polymorphic markers flanking the apo B VNTR in a sample of individuals from Lorrain, France and studied the associations between the flanking-marker haplotypes and apo B VNTR size; (3) I did computer simulations of the one-step stepwise mutation model and compared the results to real data in terms of four allele frequency distribution characteristics.^ The results of this work have allowed me to conclude that the apo B VNTR originated after an initial duplication of a sequence which is still present as a single copy sequence in New World monkey species. I conclude that this locus did not originate by the transposition of an array of repeats from somewhere else in the genome. It is unlikely that recombination is the primary mutational mechanism. Furthermore, the clustered nature of these associations implicates a stepwise mutational mechanism. From the high frequencies of certain haplotype-allele size combinations, it is evident that population level events have also been important in the determination of the apo B VNTR allele frequency distribution. Results from computer simulations of the one-step stepwise mutation model have allowed me to conclude that bimodal and multimodal allele frequency distributions are not unexpected at loci evolving via stepwise mutation mechanisms. Short tandem repeat loci fit the stepwise mutation model best, followed by microsatellite loci. I therefore conclude that there are differences in the mutational mechanisms of VNTR loci as classed by repeat unit size. (Abstract shortened by UMI.) ^
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The family of RTX (RTX representing repeats in the structural toxin) toxins is composed of several protein toxins with a characteristic nonapeptide glycine-rich repeat motif. Most of its members were shown to have cytolytic activity. By comparing the genetic relationships of the RTX toxin genes we established a set of 10 gene probes to be used for screening as-yet-unknown RTX toxin genes in bacterial species. The probes include parts of apxIA, apxIIA, and apxIIIA from Actinobacillus pleuropneumoniae, cyaA from Bordetella pertusis, frpA from Neisseria meningitidis, prtC from Erwinia chrysanthemi, hlyA and elyA from Escherichia coli, aaltA from Actinobacillus actinomycetemcomitans and lktA from Pasteurella haemolytica. A panel of pathogenic and nonpathogenic gram-negative bacteria were investigated for the presence of RTX toxin genes. The probes detected all known genes for RTX toxins. Moreover, we found potential RTX toxin genes in several pathogenic bacterial species for which no such toxins are known yet. This indicates that RTX or RTX-like toxins are widely distributed among pathogenic gram-negative bacteria. The probes generated by PCR and the hybridization method were optimized to allow broad-range screening for RTX toxin genes in one step. This included the binding of unlabelled probes to a nylon filter and subsequent hybridization of the filter with labelled genomic DNA of the strain to be tested. The method constitutes a powerful tool for the assessment of the potential pathogenicity of poorly characterized strains intended to be used in biotechnological applications. Moreover, it is useful for the detection of already-known or new RTX toxin genes in bacteria of medical importance.
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Dealing with one's emotions is a core skill in everyday life. Effective cognitive control strategies have been shown to be neurobiologically represented in prefrontal structures regulating limbic regions. In addition to cognitive strategies, mindfulness-associated methods are increasingly applied in psychotherapy. We compared the neurobiological mechanisms of these two strategies, i.e. cognitive reappraisal and mindfulness, during both the cued expectation and perception of negative and potentially negative emotional pictures. Fifty-three healthy participants were examined with functional magnetic resonance imaging (47 participants included in analysis). Twenty-four subjects applied mindfulness, 23 used cognitive reappraisal. On the neurofunctional level, both strategies were associated with comparable activity of the medial prefrontal cortex and the amygdala. When expecting negative versus neutral stimuli, the mindfulness group showed stronger activations in ventro- and dorsolateral prefrontal cortex, supramarginal gyrus as well as in the left insula. During the perception of negative versus neutral stimuli, the two groups only differed in an increased activity in the caudate in the cognitive group. Altogether, both strategies recruited overlapping brain regions known to be involved in emotion regulation. This result suggests that common neural circuits are involved in the emotion regulation by mindfulness-based and cognitive reappraisal strategies. Identifying differential activations being associated with the two strategies in this study might be one step towards a better understanding of differential mechanisms of change underlying frequently used psychotherapeutic interventions.
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We consider the problem of twenty questions with noisy answers, in which we seek to find a target by repeatedly choosing a set, asking an oracle whether the target lies in this set, and obtaining an answer corrupted by noise. Starting with a prior distribution on the target's location, we seek to minimize the expected entropy of the posterior distribution. We formulate this problem as a dynamic program and show that any policy optimizing the one-step expected reduction in entropy is also optimal over the full horizon. Two such Bayes optimal policies are presented: one generalizes the probabilistic bisection policy due to Horstein and the other asks a deterministic set of questions. We study the structural properties of the latter, and illustrate its use in a computer vision application.
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Using quantum Monte Carlo, we study the nonequilibrium transport of magnetization in large open strongly correlated quantum spin-12 systems driven by purely dissipative processes that conserve the uniform or staggered magnetization, disregarding unitary Hamiltonian dynamics. We prepare both a low-temperature Heisenberg ferromagnet and an antiferromagnet in two parts of the system that are initially isolated from each other. We then bring the two subsystems in contact and study their real-time dissipative dynamics for different geometries. The flow of the uniform or staggered magnetization from one part of the system to the other is described by a diffusion equation that can be derived analytically.
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Background. HPV is the underlying cause of cervical cancer, a malignant tumor of the female genital tract. Each year, cervical cancer is newly diagnosed in approximately 10,000 women, and over 3,000 women die from the malignancy. In addition, HPV is implicated as a cause of other cancers involving the genital tract, male and female, and the head and neck. ^ Gardasil, a vaccine against HPV, was licensed by the FDA in June 2006. Early study results have shown Gardasil to be safe and effective at preventing HPV infections that are commonly associated with the development of cervical cancer, as well as other HPV-related cancers and genital warts. The vaccine is most effective when administered in childhood, before initial exposure to HPV, which typically occurs shortly after the onset of sexual activity. Accordingly, the CDC's Advisory Committee on Immunization Practices (ACIP) has recommended routine vaccination of females aged 11-12 years. ^ Taking the ACIP recommendation one step further, many states have considered school-based mandates of the HPV vaccine in an attempt to reduce the burden of HPV-related illness, in particular to reduce the disparately high incidence of cervical cancer in medically underserved populations. These mandate attempts have sparked heated debate—highlighting public concerns regarding adolescent sexuality, corporate greed, and vaccines in general. ^ Methods. My research focuses on publicly available sources of information such as medical journals, government reports (federal and state), NGO reports, newspapers, and books. I begin with a background discussion of HPV, cervical cancer, and the HPV vaccine. I then discuss public health policy issues related to vaccines, vaccine mandates, and HPV-related illness. Specifically, I discuss the public health benefit of previous vaccine mandates, the legality of vaccine mandates, and the undue corporate influence on the politics of instituting HPV vaccine mandates. In addition, I examine some of the causes behind the anti-vaccine movement and the controversy surrounding adolescent sexuality as it pertains to the HPV vaccine. In the final section, I focus on the recent failed attempt by Governor Rick Perry to mandate the HPV vaccine in Texas. A retrospective analysis of Governor Perry's policy decisions is undertaken and recommendations are made regarding future attempts to mandate the HPV vaccine, or other vaccines under development for similar sexually transmitted viral diseases such as HIV and herpes simplex. ^ Results. In Texas, as in other states across the country, HPV vaccine mandates faced opposition from those who, while they may support mandates of other vaccines, oppose mandates for the HPV vaccine based largely on the idea that HPV is a sexually transmitted disease—they see responsible sexual behavior as the appropriate method for preventing HPV-related illness. A second major group of opposition comes from those who are generally opposed to all vaccine mandates, due to concerns that mandates are intended primarily for the financial benefit of the pharmaceutical industry or due to concerns—largely unfounded—that vaccines pose a greater health threat than the illnesses they are designed to prevent. ^ Conclusion. In order to reduce opposition to vaccine mandates, care must be taken to educate the public regarding the benefits of vaccination by mobilizing the public health sector, avoid the impression that the decision to institute mandates is rash or pressured by allowing time for open debate, and minimize lobbying efforts by vaccine manufacturers. ^
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The situational and interpersonal characteristics of homicides occurring in Houston, Texas, during 1987 were investigated. A total of 328 cases were ascertained from the linking of police computer data, medical examiner's records, and death certificate information. The medical examiner's records contained all of the ascertained cases. The comparability ratio between the medical examiner's records and police and vital statistic data was 1.03 and 0.966, respectively. Data inconsistencies were found between the three information sources on Spanish surname, age, race/ethnicity, external cause of death coding, alcohol and drug involvement, weapon/method used, and Hispanic immigration status. Recommendations for improving the quality of homicide information gathered and for linking homicide surveillance systems were made.^ Males constituted 82% of all victims. The age-adjusted homicide rate for Blacks was 31.1 per 100,000 population, for Hispanics 19.2, and for Anglos 5.4. Among males, Blacks had an age-adjusted rate of 54.5, Hispanics, 31.0, and Anglos 7.5. Among females, Blacks had an age-adjusted rate of 9.3, Hispanics 6.1, and Anglos 3.1. Black males, ages 25-34, had the highest homicide rate, at 96.5.^ Half of all homicides occurred in a residence. Among Hispanic males, homicides occurred most often in the street. Firearms were used to commit 64% of the homicides. Arguments preceded 58% of all cases. Nearly two-thirds of the victims knew their assailant. Only 15% of males compared to 62% of females were killed by a spouse, an intimate acquaintance, or a family member. Blacks (93%) and Hispanics (88%) were more likely than Anglos (70%) to have been killed by persons of the same race/ethnicity. Nearly three-fourths of all Houston Hispanic homicide victims were foreign born.^ Alcohol was detected in 47% of the victims tested. Nearly one-third of those tested had blood alcohol concentrations (BACs) greater than 100 mg%. Males (53%) were more likely than females (20%) to have positive BACs. Hispanic males (64%) were more likely to have detectable BACs than either Black (51%) or Anglo (44%) males.^ Illegal drugs were detected in 20% of the victims tested. One-fourth of the victims who tested positive for drugs had more than one drug in their system at death. The stimulant cocaine was the most commonly detected drug, comprising 53% of all illegal drugs identified.^ Recommendations for the primary, secondary, and tertiary prevention of homicide and for future homicide research are made. ^
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Objectives: To compare mental health care utilization regarding the source, types, and intensity of mental health services received, unmet need for services, and out of pocket cost among non-institutionalized psychologically distressed women and men. ^ Method: Cross-sectional data for 19,325 non-institutionalized mentally distressed adult respondents to the “The National Survey on Drug Use and Health” (NSDUH), for the years 2006 -2008, representing over twenty-nine millions U.S. adults was analyzed. To assess the relative odds for women compared to men, logistic regression analysis was used for source of service, for types of barriers, for unmet need and cost; zero inflated negative binomial regression for intensity of utilization; and ordinal logistic regression analysis for quantifying out-of-pocket expenditure. ^ Results: Overall, 43% of mentally distressed adults utilized a form of mental health treatment; representing 12.6 million U.S psychologically distressed adults. Females utilized more mental health care compared to males in the previous 12 months (OR: 1. 70; 95% CI: 1.54, 1.83). Similarly, females were 54% more likely to get help for psychological distress in an outpatient setting and females were associated with an increased probability of using medication for mental distress (OR: 1.72; 95% CI: 1.63, 1.98). Women were 1.25 times likelier to visit a mental health center (specialty care) than men. ^ Females were positively associated with unmet needs (OR: 1.50; 95% CI: 1.29, 1.75) after taking into account predisposing, enabling, and need (PEN) characteristics. Women with perceived unmet needs were 23% (OR: 0.77; 95% CI: 0.59, 0.99) less likely than men to report societal accommodation (stigma) as a barrier to mental health care. At any given cutoff point, women were 1.74 times likelier to be in the higher payment categories for inpatient out of pocket cost when other variables in the model are held constant. Conclusions: Women utilize more specialty mental healthcare, report more unmet need, and pay more inpatient out of pocket costs than men. These gender disparities exist even after controlling for predisposing, enabling, and need variables. Creating policies that not only provide mental health care access but also de-stigmatize mental illness will bring us one step closer to eliminating gender disparities in mental health care.^
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Sixty-five chert, porcellanite, and siliceous-chalk samples from Deep Sea Drilling Project Leg 62 were analyzed by petrography, scanning electron microscopy, analysis by energy-dispersive X-rays, X-ray diffraction, X-ray spectroscopy, and semiquantitative emission spectroscopy. Siliceous rocks occur mainly in chalks, but also in pelagic clay and marlstone at Site 464. Overall, chert probably constitutes less than 5% of the sections and occurs in deposits of Eocene to Barremian ages at sub-bottom depths of 10 to 820 meters. Chert nodules and beds are commonly rimmed by quartz porcellanite; opal-CT-rich rocks are minor in Leg 62 sediments 65 to 108 m.y. old and at sub-bottom depths of 65 to 520 meters. Chert ranges from white to black, shades of gray and brown being most common; yellow-brown and red-brown jaspers occur at Site 464. Seventy-eight percent of the studied cherts contain easily recognizable burrow structures. The youngest chert at Site 463 is a quartz cast of a burrow. Burrow silica maturation is always one step ahead of host-rock silicification. Burrows are commonly loci for initial silicification of the host carbonate. Silicification takes place by volume-f or-volume replacement of carbonate sediment, and more-clay-rich sediment at Site 464. Nannofossils are commonly pseudomorphically replaced by quartz near the edges of chert beds and nodules. Other microfossils, mostly radiolarians and foraminifers, whether in chalk or chert, can be either filled with or replaced by calcite, opal-CT, and (or) quartz. Chemical micro-environments ultimately control the removal, transport, and precipitation of calcite and silica. Two cherts from Site 465 contain sulfate minerals replaced by quartz. Site 465 was never subaerially exposed after sedimentation began, and the formation of the sulfate minerals and their subsequent replacement probably occurred in the marine environment. Several other cherts with odd textures are described in this paper, including (1) a chert breccia cemented by colloform opal-CT and chalcedony, (2) a transition zone between white porcellanite containing opal-CT and quartz and a burrowed brown chert, consisting of radial aggregates of opal-CT with hollow centers, and (3) a chert that consists of silica-replaced calcite pseudospherules interspersed with streaks and circular masses of dense quartz. X-ray-diffraction analyses show that when data from all sites are considered there are poorly defined trends indicating that older cherts have better quartz crystallinity than younger ones, and that opal-CT crystallite size increases and opal-CT cf-spacings decrease with depth of occurrence in the sections. In a general way, depth of burial and the presence of calcite promote the ordering in the opal-CT crystal structure which allows its eventual conversion to quartz. Opal-CT in porcellanites converts to quartz after reaching a minimum d-spacing of 4.07 Å. Quartz/opal-CT ratios and quartz crystallinity vary randomly on a fine scale across four chert beds, but quartz crystallinity increases from the edge to the center of a fifth chert bed; this may indicate maturation of the silica. Twenty-four rocks were analyzed for their major- and minor-element compositions. Many elements in cherts are closely related to major mineral components. The carbonate component is distinguished by high values of CaO, MgO, Mn, Ba, Sr, and (for unknown reasons) Zr. Tuffaceous cherts have high values of K and Al, and commonly Zn, Mo, and Cr. Pure cherts are characterized by high SiO2 and B. High B may be a good indicator of formation of chert in an open marine environment, isolated from volcanic and terrigenous materials.
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En estos tiempos de crisis se hace imperativo lograr un consumo de recursos públicos lo más racional posible. El transporte público urbano es un sector al que se dedican grandes inversiones y cuya prestación de servicios está fuertemente subvencionada. El incremento de la eficiencia técnica del sector, entendida como la relación entre producción de servicios y consumo de recursos, puede ayudar a conseguir una mejor gestión de los fondos públicos. Un primer paso para que se produzca una mejora es el desarrollo de una metodología de evaluación de la eficiencia técnica de las compañías de transporte público. Existen diferentes métodos para la evaluación técnica de un conjunto de compañías pertenecientes a un sector. Uno de los más utilizados es el método frontera, en el que se encuentra el análisis envolvente de datos (Data Envelopment Analysis, DEA, por sus siglas en inglés). Este método permite establecer una frontera de eficiencia técnica relativa a un determinado grupo de compañías, en función de un número limitado de variables. Las variables deben cuantificar, por un lado, la prestación de servicios de las distintas compañías (outputs), y por el otro, los recursos consumidos en la producción de dichos servicios (inputs). El objetivo de esta tesis es analizar, mediante el uso del método DEA, la eficiencia técnica de los servicios de autobuses urbanos en España. Para ello, se estudia el número de variables más adecuado para conformar los modelos con los que se obtienen las fronteras de eficiencia. En el desarrollo de la metodología se utilizan indicadores de los servicios de autobús urbano de las principales ciudades de las áreas metropolitanas españolas, para el periodo 2004-2009. In times of crisis it is imperative achieve a consumption of public resources as rational as possible. Urban public transport is a sector devoted to large investments and whose services are heavily subsidized. Increase the technical efficiency of the sector, defined as the ratio of service output and resource consumption, can help achieve a better management of public funds. One step to produce an improvement is the development of a methodology for evaluating the technical efficiency of the public transport companies. There are different methods for the technical evaluation of a set of companies within an industry. One of the most widely used methods is the frontier method, in particular the Data Envelopment Analysis (DEA). This method allows the calculation of a technical efficiency frontier on a specific group of companies, based on a limited number of variables. Variables must quantify, on the one hand, the provision of services of different companies (outputs), and on the other hand, the resources consumed in the production of such services (inputs). The objective of this thesis is to analyze, using the DEA method, the technical efficiency of urban bus services in Spain. For this purpose, it is studied the more suitable variables that can be used in the models to obtain the efficiency frontiers. In developing the methodology are used indicators of urban bus services in major cities of the Spanish metropolitan areas for the period 2004-2009.
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Wind power time series usually show complex dynamics mainly due to non-linearities related to the wind physics and the power transformation process in wind farms. This article provides an approach to the incorporation of observed local variables (wind speed and direction) to model some of these effects by means of statistical models. To this end, a benchmarking between two different families of varying-coefficient models (regime-switching and conditional parametric models) is carried out. The case of the offshore wind farm of Horns Rev in Denmark has been considered. The analysis is focused on one-step ahead forecasting and a time series resolution of 10 min. It has been found that the local wind direction contributes to model some features of the prevailing winds, such as the impact of the wind direction on the wind variability, whereas the non-linearities related to the power transformation process can be introduced by considering the local wind speed. In both cases, conditional parametric models showed a better performance than the one achieved by the regime-switching strategy. The results attained reinforce the idea that each explanatory variable allows the modelling of different underlying effects in the dynamics of wind power time series.