922 resultados para Galvanic couples


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Formative cell divisions are critical for multicellular patterning. In the early plant embryo, such divisions follow from orienting the division plane. A major unanswered question is how division plane orientation is genetically controlled, and in particular whether this relates to cell geometry. We have generated a complete 4D map of early Arabidopsis embryogenesis and used computational analysis to demonstrate that several divisions follow a rule that uses the smallest wall area going through the center of the cell. In other cases, however, cell division clearly deviates from this rule, which invariably leads to asymmetric cell division. By analyzing mutant embryos and through targeted genetic perturbation, we show that response to the hormone auxin triggers a deviation from the ``shortest wall'' rule. Our work demonstrates that a simple default rule couples division orientation to cell geometry in the embryo and that genetic regulation can create patterns by overriding the default rule.

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The vestibular system contributes to the control of posture and eye movements and is also involved in various cognitive functions including spatial navigation and memory. These functions are subtended by projections to a vestibular cortex, whose exact location in the human brain is still a matter of debate (Lopez and Blanke, 2011). The vestibular cortex can be defined as the network of all cortical areas receiving inputs from the vestibular system, including areas where vestibular signals influence the processing of other sensory (e.g. somatosensory and visual) and motor signals. Previous neuroimaging studies used caloric vestibular stimulation (CVS), galvanic vestibular stimulation (GVS), and auditory stimulation (clicks and short-tone bursts) to activate the vestibular receptors and localize the vestibular cortex. However, these three methods differ regarding the receptors stimulated (otoliths, semicircular canals) and the concurrent activation of the tactile, thermal, nociceptive and auditory systems. To evaluate the convergence between these methods and provide a statistical analysis of the localization of the human vestibular cortex, we performed an activation likelihood estimation (ALE) meta-analysis of neuroimaging studies using CVS, GVS, and auditory stimuli. We analyzed a total of 352 activation foci reported in 16 studies carried out in a total of 192 healthy participants. The results reveal that the main regions activated by CVS, GVS, or auditory stimuli were located in the Sylvian fissure, insula, retroinsular cortex, fronto-parietal operculum, superior temporal gyrus, and cingulate cortex. Conjunction analysis indicated that regions showing convergence between two stimulation methods were located in the median (short gyrus III) and posterior (long gyrus IV) insula, parietal operculum and retroinsular cortex (Ri). The only area of convergence between all three methods of stimulation was located in Ri. The data indicate that Ri, parietal operculum and posterior insula are vestibular regions where afferents converge from otoliths and semicircular canals, and may thus be involved in the processing of signals informing about body rotations, translations and tilts. Results from the meta-analysis are in agreement with electrophysiological recordings in monkeys showing main vestibular projections in the transitional zone between Ri, the insular granular field (Ig), and SII.

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Eine vergleichende Analyse der Regulierung von Schwangerschaftsabbrüchen und gleichgeschlechtlichen Partnerschaften in Westeuropa im Zeitraum von 1960 bis 2010 zeigt, dass katholisch geprägte Staaten diese Bereiche grundsätzlich nicht weniger stark liberalisiert haben als andere Länder. Allerdings drosselt der Katholizismus offensichtlich die Geschwindigkeit von Reformprozessen. Auf Basis einer detaillierten explorativen Analyse der Politikentwicklungen in Österreich, das sehr früh die Gesetzgebung zum Schwangerschaftsabbruch lockerte, jedoch bei der Einführung registrierter homosexueller Partnerschaften lange zögerte, leiten wir induktiv theoretische Implikationen ab: Die katholische Kirche kann permissive Reformen so lange verhindern, wie institutionelle und kulturelle Gelegenheitsstrukturen nicht der säkular-liberalen Opposition behilflich sind, erfolgreiches Agenda-Setting zu betreiben und Mehrheiten für einen Politikwechsel zu gewinnen.

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In this thesis, we develop an adaptive framework for Monte Carlo rendering, and more specifically for Monte Carlo Path Tracing (MCPT) and its derivatives. MCPT is attractive because it can handle a wide variety of light transport effects, such as depth of field, motion blur, indirect illumination, participating media, and others, in an elegant and unified framework. However, MCPT is a sampling-based approach, and is only guaranteed to converge in the limit, as the sampling rate grows to infinity. At finite sampling rates, MCPT renderings are often plagued by noise artifacts that can be visually distracting. The adaptive framework developed in this thesis leverages two core strategies to address noise artifacts in renderings: adaptive sampling and adaptive reconstruction. Adaptive sampling consists in increasing the sampling rate on a per pixel basis, to ensure that each pixel value is below a predefined error threshold. Adaptive reconstruction leverages the available samples on a per pixel basis, in an attempt to have an optimal trade-off between minimizing the residual noise artifacts and preserving the edges in the image. In our framework, we greedily minimize the relative Mean Squared Error (rMSE) of the rendering by iterating over sampling and reconstruction steps. Given an initial set of samples, the reconstruction step aims at producing the rendering with the lowest rMSE on a per pixel basis, and the next sampling step then further reduces the rMSE by distributing additional samples according to the magnitude of the residual rMSE of the reconstruction. This iterative approach tightly couples the adaptive sampling and adaptive reconstruction strategies, by ensuring that we only sample densely regions of the image where adaptive reconstruction cannot properly resolve the noise. In a first implementation of our framework, we demonstrate the usefulness of our greedy error minimization using a simple reconstruction scheme leveraging a filterbank of isotropic Gaussian filters. In a second implementation, we integrate a powerful edge aware filter that can adapt to the anisotropy of the image. Finally, in a third implementation, we leverage auxiliary feature buffers that encode scene information (such as surface normals, position, or texture), to improve the robustness of the reconstruction in the presence of strong noise.

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Up to one third of the general population suffers from symptoms caused by hemorrhoids. Conservative treatment comes first unless the patient presents with an acute hemorrhoidal prolapse or a thrombosis. A fiber enriched diet is the primary treatment option, recommended in the perioperative period as well as a long-term prophylaxis. A timely limited application of topical ointments or suppositories and/or flavonoids are further treatment options. When symptoms persist interventional procedures for grade I-II hemorrhoids, and surgery for grade III-IV hemorrhoids should be considered. Rubber band ligation is the interventional treatment of choice. A comparable efficacy using sclerosing or infrared therapy has not yet been demonstrated. We therefore do not recommend these treatment options for the cure of hemorrhoids. Self-treatment by anal insertion of bougies is of lowrisk and may be successful, particularly in the setting of an elevated sphincter pressure. Anal dilation, sphincterotomy, cryosurgery, bipolar diathermy, galvanic electrotherapy, and heat therapy should be regarded as obsolete given the poor or missing data reported for these methods. For a long time, the classic excisional hemorrhoidectomy was considered to be the gold standard as far as surgical procedures are concerned. Primary closure (Ferguson) seems to be superior compared to the "open" version (Milligan Morgan) with respect to postoperative pain and wound healing. The more recently proposed stapled hemorrhoidopexy (Longo) is particularly advisable for circular hemorrhoids. Compared to excisional hemorrhoidectomy the Longo-operation is associated with reduced postoperative pain, shorter operation time and hospital stay as well as a faster recovery, with the disadvantage though of a higher recurrence rate. Data from Hemorrhoidal Artery Ligation (HAL)-, if appropriate in combination with a Recto-Anal Repair (HAL/RAR)-, demonstrates a similar trend towards a better tolerance of the procedure at the expense of a higher recurrence rate. These relatively "new" procedures equally qualify for the treatment of grade III and IV hemorrhoids, and, in the case of stapled hemorrhoidopexy, may even be employed in the emergency situation of an acute anal prolapse. While under certain circumstances different treatment options are equivalent, there is a clear specificity with respect to the application of those procedures in other situations. The respective pros and cons need to be discussed separately with every patient. According to their own requirements a treatment strategy has to be defined according to their individual requirements.

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Objectives Social support receipt from one's partner is assumed to be beneficial for successful smoking cessation. However, support receipt can have costs. Recent research suggests that the most effective support is unnoticed by the receiver (i.e., invisible). Therefore, this study examined the association between everyday levels of dyadic invisible emotional and instrumental support, daily negative affect, and daily smoking after a self-set quit attempt in smoker–non-smoker couples. Methods Overall, 100 smokers (72.0% men, mean age M = 40.48, SD = 9.82) and their non-smoking partners completed electronic diaries from a self-set quit date on for 22 consecutive days, reporting daily invisible emotional and instrumental social support, daily negative affect, and daily smoking. Results Same-day multilevel analyses showed that at the between-person level, higher individual mean levels of invisible emotional and instrumental support were associated with less daily negative affect. In contrast to our assumption, more receipt of invisible emotional and instrumental support was related to more daily cigarettes smoked. Conclusions The findings are in line with previous results, indicating invisible support to have beneficial relations with affect. However, results emphasize the need for further prospective daily diary approaches for understanding the dynamics of invisible support on smoking cessation.

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The ba3-type cytochrome c oxidase from Thermus thermophilus is a membrane-bound protein complex that couples electron transfer to O2 to proton translocation across the membrane. To elucidate the mechanism of the redox-driven proton pumping, we investigated the kinetics of electron and proton transfer in a structural variant of the ba3 oxidase where a putative "pump site" was modified by replacement of Asp372 by Ile. In this structural variant, proton pumping was uncoupled from internal electron transfer and O2 reduction. The results from our studies show that proton uptake to the pump site (time constant ∼65 μs in the wild-type cytochrome c oxidase) was impaired in the Asp372Ile variant. Furthermore, a reaction step that in the wild-type cytochrome c oxidase is linked to simultaneous proton uptake and release with a time constant of ∼1.2 ms was slowed to ∼8.4 ms, and in Asp372Ile was only associated with proton uptake to the catalytic site. These data identify reaction steps that are associated with protonation and deprotonation of the pump site, and point to the area around Asp372 as the location of this site in the ba3 cytochrome c oxidase.

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Purpose – There is much scientific interest in the connection between the emergence of gender-based inequalities and key biographical transition points of couples in long-term relationships. Little empirical research is available comparing the evolution of a couple’s respective professional careers over space and time. The purpose of this paper is to contribute to filling this gap by addressing the following questions: what are the critical biographical moments when gender (in)equalities within a relationship begin to arise and consolidate? Which biographical decisions precede and follow such critical moments? How does decision making at critical moments impact the opportunities of both relationship partners in gaining equal access to paid employment? Design/methodology/approach – These questions are addressed from the perspectives of intersectionality and economic citizenship. Biographical interviewing is used to collect the personal and professional narratives of Swiss-, bi-national and migrant couples. The case study of a Swiss-Norwegian couple illustrates typical processes by which many skilled migrant women end up absently or precariously employed. Findings – Analysis reveals that the Scandinavian woman’s migration to Switzerland is a primary and critical moment for emerging inequality, which is then reinforced by relocation (to a small town characterized by conservative gender values) and the subsequent births of their children. It is concluded that factors of traditional gender roles, ethnicity and age intersect to create a hierarchical situation which affords the male Swiss partner more weight in terms of decision making and career advancement. Practical implications – The paper’s findings are highly relevant to the formulation of policies regarding gender inequalities and the implementation of preventive programmes within this context. Originality/value – Little empirical research is available comparing the evolution of a couple’s respective professional careers over space and time. The originality of this paper is to fill this research gap; to include migration as a critical moment for gender inequalities; to use an intersectional and geographical perspective that have been given scant attention in the literature; to use the original concept of economic citizenship; and to examine the case of a bi-national couple, which has so far not been examined by the literature on couple relationships.

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Trapped by their superordinate goal to maintain a grandiose self, narcissists navigate their relationships wishing to re-assure themselves of their specialness and superiority, using strategies bound to fail. Dyadic analyses of diary data (14 days, 83 couples) showed that narcissists focus on their partners’ shortcomings, becoming experts at detecting negative forms of support, while simultaneously minimizing their partner’s positive intentions. Partners of narcissists, in contrast, appear to have a positive bias in ongoing relationships and seem to compensate for some of the narcissists’ shortcomings. Narcissists’ focus on their own selfconstruction purposes also extends to their parenting roles. In a retrospective study, narcissistic mothers were found to demand superior performance, desiring to show-off their child, yet concurrently attributing their child’s success to themselves. They also exercise psychological control and role-reversal, requiring the child to cater to their needs, and to admire them, while simultaneously oblivious to their child’s needs and desires.

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Objectives: Recent research shows that the well-documented positive effects of marital stability on well-being and health outcomes are conditional upon the quality of marriage. To date, few studies have explored the relationship between marital satisfaction, well-being and health among very long-term married individuals. This study aims at identifying groups of long-term married persons with respect to marital satisfaction and comparing them longitudinally concerning their well-being outcomes, marital stressors, personality and socio-demographic variables. Method: Data are derived from a survey (data collection 2012 and 2014) with 374 continuously married individuals at wave 1 (mean age: 74.2 years, length of marriage: 49.2 years) and 252 at wave 2. Cluster analyses were performed comparing the clusters with regard to various well-being outcomes. The predictive power of cluster affiliation and various predictors at wave 1 on well-being outcomes at wave 2 was tested using regression analyses. Results: Two groups were identified, one happily the other unhappily married, with the happily married scoring higher on all well-being and health outcomes. Regression analyses revealed that group affiliation at wave 1 was not any longer predictive of health, emotional loneliness and hopelessness two years later, when taking into account socio-demographic variables, psychological resilience and marital strain, whereas it remained an important predictor of life satisfaction and social loneliness. Conclusion: Marital satisfaction is associated with health and well-being in older couples over time, whereas psychological resilience and marital strain are major predictors explaining the variance of these outcomes.

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BACKGROUND Taking care of children diagnosed with cancer affects parents' professional life. The impact in the long-term however, is not clear. We aimed to compare the employment situation of parents of long-term childhood cancer survivors with control parents of the general population, and to identify clinical and socio-demographic factors associated with parental employment. METHODS As part of the Swiss Childhood Cancer Survivor Study, we sent a questionnaire to parents of survivors aged 5-15 years, who survived ≥5 years after diagnosis. Information on control parents of the general population came from the Swiss Health Survey (restricted to men and women with ≥1 child aged 5-15 years). Employment was categorized as not employed, part-time, and full-time employed. We used generalized ordered logistic regression to determine associations with clinical and socio-demographic factors. Clinical data was available from the Swiss Childhood Cancer Registry. RESULTS We included 394 parent-couples of survivors and 3'341 control parents (1'731 mothers; 1'610 fathers). Mothers of survivors were more often not employed (29% versus 22%; ptrend = 0.007). However, no differences between mothers were found in multivariable analysis. Fathers of survivors were more often employed full-time (93% versus 87%; ptrend = 0.002), which remained significant in multivariable analysis. Among parents of survivors, mothers with tertiary education (OR = 2.40, CI:1.14-5.07) were more likely to be employed. Having a migration background (OR = 3.63, CI: 1.71-7.71) increased the likelihood of being full-time employed in mothers of survivors. Less likely to be employed were mothers of survivors diagnosed with lymphoma (OR = 0.31, CI:0.13-0.73) and >2 children (OR = 0.48, CI:0.30-0.75); and fathers of survivors who had had a relapse (OR = 0.13, CI:0.04-0.36). CONCLUSION Employment situation of parents of long-term survivors reflected the more traditional parenting roles. Specific support for parents with low education, additional children, and whose child had a more severe cancer disease could improve their long-term employment situation.

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We propose dual-domain filtering, an image processing paradigm that couples spatial domain with frequency domain filtering. Our dual-domain defined filter removes artifacts like residual noise of other image denoising methods and compression artifacts. Moreover, iterating the filter achieves state-of-the-art image denoising results, but with a much simpler algorithm than competing approaches. The simplicity and versatility of the dual-domain filter makes it an attractive tool for image processing.

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The Interstellar Boundary Explorer (IBEX) samples the interstellar neutral (ISN) gas flow of several species every year from December through late March when the Earth moves into the incoming flow. The first quantitative analyses of these data resulted in a narrow tube in four-dimensional interstellar parameter space, which couples speed, flow latitude, flow longitude, and temperature, and center values with approximately 3° larger longitude and 3 km s⁻¹ lower speed, but with temperatures similar to those obtained from observations by the Ulysses spacecraft. IBEX has now recorded six years of ISN flow observations, providing a large database over increasing solar activity and using varying viewing strategies. In this paper, we evaluate systematic effects that are important for the ISN flow vector and temperature determination. We find that all models in use return ISN parameters well within the observational uncertainties and that the derived ISN flow direction is resilient against uncertainties in the ionization rate. We establish observationally an effective IBEX-Lo pointing uncertainty of ±0°18 in spin angle and confirm an uncertainty of ±0°1 in longitude. We also show that the IBEX viewing strategy with different spin-axis orientations minimizes the impact of several systematic uncertainties, and thus improves the robustness of the measurement. The Helium Warm Breeze has likely contributed substantially to the somewhat different center values of the ISN flow vector. By separating the flow vector and temperature determination, we can mitigate these effects on the analysis, which returns an ISN flow vector very close to the Ulysses results, but with a substantially higher temperature. Due to coupling with the ISN flow speed along the ISN parameter tube, we provide the temperature Tvisn∞=8710+440/-680 K for Visn∞=26 km s⁻¹ for comparison, where most of the uncertainty is systematic and likely due to the presence of the Warm Breeze.

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This paper examines how preference correlation and intercorrelation combine to influence the length of a decentralized matching market's path to stability. In simulated experiments, marriage markets with various preference specifications begin at an arbitrary matching of couples and proceed toward stability via the random mechanism proposed by Roth and Vande Vate (1990). The results of these experiments reveal that fundamental preference characteristics are critical in predicting how long the market will take to reach a stable matching. In particular, intercorrelation and correlation are shown to have an exponential impact on the number of blocking pairs that must be randomly satisfied before stability is attained. The magnitude of the impact is dramatically different, however, depending on whether preferences are positively or negatively intercorrelated.

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Abstract: In recent decades, the structure of the American family has been revolutionized to incorporate families of diverse and unconventional compositions. Gay and lesbian couples have undoubtedly played a crucial role in this revolution by establishing families through the tool of adoption. Eleven adoptive parents from the state of Connecticut were interviewed to better conceptualize the unique barriers gay couples encounter in the process adoption. Both the scholarly research and the interview data illustrate that although gay couples face enormous legal barriers, the majority of their hardship comes through social interactions. As a result, the cultural myths and legal restrictions that create social hardships for gay adoptive parents forge a vicious and discriminatory cycle of marginalization that American legal history illustrates is best remedied through judicial intervention at the Supreme Court level. While judicial intervention, alone, cannot change the reality of gay parenthood, I argue that past judicial precedent illustrates that such change can serve as a tool of individual, political, and legal validation for the gay community for obtaining equal rights.