930 resultados para Lateral dominance
Resumo:
Human electrophysiological studies support a model whereby sensitivity to so-called illusory contour stimuli is first seen within the lateral occipital complex. A challenge to this model posits that the lateral occipital complex is a general site for crude region-based segmentation, based on findings of equivalent hemodynamic activations in the lateral occipital complex to illusory contour and so-called salient region stimuli, a stimulus class that lacks the classic bounding contours of illusory contours. Using high-density electrical mapping of visual evoked potentials, we show that early lateral occipital cortex activity is substantially stronger to illusory contour than to salient region stimuli, whereas later lateral occipital complex activity is stronger to salient region than to illusory contour stimuli. Our results suggest that equivalent hemodynamic activity to illusory contour and salient region stimuli probably reflects temporally integrated responses, a result of the poor temporal resolution of hemodynamic imaging. The temporal precision of visual evoked potentials is critical for establishing viable models of completion processes and visual scene analysis. We propose that crude spatial segmentation analyses, which are insensitive to illusory contours, occur first within dorsal visual regions, not the lateral occipital complex, and that initial illusory contour sensitivity is a function of the lateral occipital complex.
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Dominance hierarchies pervade animal societies. Within a static social environment, in which group size and composition are unchanged, an individual's hierarchy rank results from intrinsic (e.g. body size) and extrinsic (e.g. previous experiences) factors. Little is known, however, about how dominance relationships are formed and maintained when group size and composition are dynamic. Using a fusion-fission protocol, we fused groups of previously isolated shore crabs (Carcinus maenas) into larger groups, and then restored groups to their original size and composition. Pre-fusion hierarchies formed independently of individuals' sizes, and were maintained within a static group via winner/loser effects. Post-fusion hierarchies differed from pre-fusion ones; losing fights during fusion led to a decline in an individual's rank between pre- and post-fusion conditions, while spending time being aggressive during fusion led to an improvement in rank. In post-fusion tanks, larger individuals achieved better ranks than smaller individuals. In conclusion, dominance hierarchies in crabs represent a complex combination of intrinsic and extrinsic factors, in which experiences from previous groups can carry over to affect current competitive interactions.
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The Epstein-Barr virus (EBV) is the etiological agent of oral hairy leukoplakia (OHL), an oral lesion with important diagnostic and prognostic value in acquired immunodeficiency disease syndrome. The two EBV genotypes, EBV-1 and EBV-2, can be distinguished by divergent gene sequences encoding the EBNA-2, 3A, 3B, and 3C proteins. The purpose of this study was to identify the EBV genotype prevalent in 53 samples of scrapings from the lateral border of the tongue of HIV-1 seropositive patients, with and without OHL, and to correlate the genotypes with presence of clinical or subclinical OHL with the clinic data collected. EBV-1 and EBV-2 were identified through PCR and Nested-PCR based on sequence differences of the EBNA-2 gene. EBV-1 was identified in the 31 samples (15 without OHL, 7 with clinical OHL and 9 with subclinical OHL), EBV-2 in 12 samples (10 without OHL, 1 with clinical and 1 subclinical OHL), and a mixed infection in 10 samples (2 without OHL, 3 with clinical and 5 with subclinical OHL). The presence of EBV-1 was higher in women, but a significant statistical result relating one the EBV genotypes to the development of OHL was not found. We conclude that the oral epithelium in HIV-1 seropositive patients can be infected by EBV-1, EBV-2 or by a mixed viral population.
Resumo:
Over the past decade, significant interest has been expressed in relating the spatial statistics of surface-based reflection ground-penetrating radar (GPR) data to those of the imaged subsurface volume. A primary motivation for this work is that changes in the radar wave velocity, which largely control the character of the observed data, are expected to be related to corresponding changes in subsurface water content. Although previous work has indeed indicated that the spatial statistics of GPR images are linked to those of the water content distribution of the probed region, a viable method for quantitatively analyzing the GPR data and solving the corresponding inverse problem has not yet been presented. Here we address this issue by first deriving a relationship between the 2-D autocorrelation of a water content distribution and that of the corresponding GPR reflection image. We then show how a Bayesian inversion strategy based on Markov chain Monte Carlo sampling can be used to estimate the posterior distribution of subsurface correlation model parameters that are consistent with the GPR data. Our results indicate that if the underlying assumptions are valid and we possess adequate prior knowledge regarding the water content distribution, in particular its vertical variability, this methodology allows not only for the reliable recovery of lateral correlation model parameters but also for estimates of parameter uncertainties. In the case where prior knowledge regarding the vertical variability of water content is not available, the results show that the methodology still reliably recovers the aspect ratio of the heterogeneity.
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El grup de Visió per Computador i Robòtica (VICOROB) disposa de varis robotssubmarins per a la recerca i inspecció subaquàtica. Recentment s’ha adquiritun sensor sonar d’escombrat lateral el qual s’utilitza per realitzar imatgesacústiques del fons marí quan aquest es mou principalment a velocitat constanti mantenint el rumb.Els robots del grup VICOROB estan equipats amb diferents tipus de sensors icàmeres per analitzar el fons marí. Aquest sensors són de gran qualitat ipermeten conèixer de manera bastant satisfactòria l’entorn a les proximitats delrobot. Freqüentment però, aquest sensors estant sotmesos a diferentsrestriccions depenent de la seva naturalesa de funcionament, de tal maneraque es necessària la seva combinació per resoldre determinats problemes endiferents situacions.Amb aquest projecte, es pretén integrar un nou sistema de captura d’imatgessonores del fons marí, en un dels robots. Amb la integració d’aquest nousensor, s’espera obtenir una opció alternativa els sistemes actuals que puguiaportar informació addicional sobre el fons. Aquest sistema podrà ser utilitzatper realitzar tasques per les quals els altres sensors no estant preparats o béper complementar informació d’altres sensor
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En port: Un instrumento de cooperación entre servicios y asociaciones para ganar Salud. Trabajar en clave de Recuperación con la persona afectada y sus familias. Y apoyar la labor de la personas cuidadoras. Es una de las estrategias del proyecto "AL LADO" con... Publicado en la página web de la Consejería de Salud y Bienestar Social: Consejería de Salud y Bienestar Social / Ciudadanía / Participar en Salud / 'Al Lado' con... / 'Al Lado' con las personas afectadas por Esclerosis Lateral Amiotrófica
Resumo:
Objective: To assess the maternal comfort and reduction of pain associated with contractions during labor with “hands-knees” (HK) maternal posture compared with “lateral maternal postures toward the fetal back” in pregnant women with occipitoposterior (OP) fetal position. Methods: In the multicenter trial by randomization, 70 women with OP fetal position during labor took the lateral posture and 65 women the HK posture for at least 30 minutes. We analyzed maternal comfort, perceived pain, influence of epidural analgesia and use of fit-ball on posture HK. Results: Back pain and abdominal pain reduction was higher with HK posture. With lateral posture 78.6% of women expressed comfort versus 73.8% of women with HK posture. Regarding the lateral posture, the comfort with HK posture reduces in multiparous women, with an odds ratio (OR) of 0.29, for a confidence interval (CI) 95% 0.12 to 0.76, and epidural analgesia (OR= 0.39; CI 95%: 0.15-1.03), comfort with K posture is higher with reduction of pain (OR= 4.13, 95% CI: 1.34- 12.72) and abdominal pain compared with back pain (OR= 4.05, 95% CI: 1.36-11.85). Conclusions: Women consider comfortable lateral and HK maternal postures during labor. The lateral posture is most comfortable for multiparous and epidural analgesia. The reduction of pain during labor is higher with HK posture, recommending this posture in primiparous women without epidural analgesia.
Resumo:
Many animals that live in groups maintain competitive relationships, yet avoid continual fighting, by forming dominance hierarchies. We compare predictions of stochastic, individual-based models with empirical experimental evidence using shore crabs to test competing hypotheses regarding hierarchy development. The models test (1) what information individuals use when deciding to fight or retreat, (2) how past experience affects current resource-holding potential, and (3) how individuals deal with changes to the social environment. First, we conclude that crabs assess only their own state and not their opponent's when deciding to fight or retreat. Second, willingness to enter, and performance in, aggressive contests are influenced by previous contest outcomes. Winning increases the likelihood of both fighting and winning future interactions, while losing has the opposite effect. Third, when groups with established dominance hierarchies dissolve and new groups form, individuals reassess their ranks, showing no memory of previous rank or group affiliation. With every change in group composition, individuals fight for their new ranks. This iterative process carries over as groups dissolve and form, which has important implications for the relationship between ability and hierarchy rank. We conclude that dominance hierarchies emerge through an interaction of individual and social factors, and discuss these findings in terms of an underlying mechanism. Overall, our results are consistent with crabs using a cumulative assessment strategy iterated across changes in group composition, in which aggression is constrained by an absolute threshold in energy spent and damage received while fighting.
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Female mate choice influences the maintenance of genetic variation by altering the mating success of males with different genotypes. The evolution of preferences themselves, on the other hand, depends on genetic variation present in the population. Few models have tracked this feedback between a choice gene and its effects on genetic variation, in particular when genes that determine offspring viability and attractiveness have dominance effects. Here we build a population genetic model that allows comparing the evolution of various choice rules in a single framework. We first consider preferences for good genes and show that focused preferences for homozygotes evolve more easily than broad preferences, which allow heterozygous males high mating success too. This occurs despite better maintenance of genetic diversity in the latter scenario, and we discuss why empirical findings of superior mating success of heterozygous males consequently do not immediately lead to a better understanding of the lek paradox. Our results thus suggest that the mechanisms that help maintain genetic diversity also have a flipside of making female choice an inaccurate means of producing the desired kind of offspring. We then consider preferences for heterozygosity per se, and show that these evolve only under very special conditions. Choice for compatible genotypes can evolve but its selective advantage diminishes quickly due to frequency-dependent selection. Finally, we show that our model reproduces earlier results on selfing, when the female choice strategy produces assortative mating. Overall, our model indicates that various forms of heterozygote-favouring (or variable) female choice pose a problem for the theory of sexual ornamentation based on indirect benefits, rather than a solution.
Prótesis unicompartimental lateral de rodilla. Indicaciones, técnica y resultados a mediocorto plazo
Resumo:
Objectives: In patients with lateral osteoarthritis of the knee, use of external unicompartmental knee arthroplasty it is a well known surgical alternative, used by the minor trauma involved, short hospital stay and rapid recovery. The purpose of this study is to show the clinical outcomes to short-medium term of patients undergoing this procedure. Methods: we describe the technique used and the peculiarities of the prosthesis (A Mobile-bearing lateral unicompartmental knee replacement, Oxford Domed ®). This is an observational retrospective longitudinal study, of 15 arthroplasties performed in 13 women and 2 men, between 2010 and 2013, with a mean age of 60’7 years, with a diagnosis of lateral osteoarthritis of the knee, without involvement of the medial or patellofemoral compartment and cruciate ligaments functionally intact, with a mean follow up of 25 months. All patients complete the Oxford Knee Score and Visual Analog Scale (VAS) during the study. Results: The results are favorable, with an improvement of 6.60 points on the EVA, 3.73 for 1 in the postoperatory funcionality, the OKS very satisfactory with an average of 38 points over 50 and without any postoperative function surgical revision. Anserine tendinitis was observed in 20% of cases. Conclusions: The benefits of this surgery against their alternatives are assessed, and their potential drawbacks. External unicompartmental knee arthroplasty is an effective alternative in cases of knee osteoarthritis of the lateral compartment with no other associated injuries.
Resumo:
BACKGROUND: The evidence base for the diagnosis and management of amyotrophic lateral sclerosis (ALS) is weak. OBJECTIVES: To provide evidence-based or expert recommendations for the diagnosis and management of ALS based on a literature search and the consensus of an expert panel. METHODS: All available medical reference systems were searched, and original papers, meta-analyses, review papers, book chapters and guidelines recommendations were reviewed. The final literature search was performed in February 2011. Recommendations were reached by consensus. RECOMMENDATIONS: Patients with symptoms suggestive of ALS should be assessed as soon as possible by an experienced neurologist. Early diagnosis should be pursued, and investigations, including neurophysiology, performed with a high priority. The patient should be informed of the diagnosis by a consultant with a good knowledge of the patient and the disease. Following diagnosis, the patient and relatives/carers should receive regular support from a multidisciplinary care team. Medication with riluzole should be initiated as early as possible. Control of symptoms such as sialorrhoea, thick mucus, emotional lability, cramps, spasticity and pain should be attempted. Percutaneous endoscopic gastrostomy feeding improves nutrition and quality of life, and gastrostomy tubes should be placed before respiratory insufficiency develops. Non-invasive positive-pressure ventilation also improves survival and quality of life. Maintaining the patient's ability to communicate is essential. During the entire course of the disease, every effort should be made to maintain patient autonomy. Advance directives for palliative end-of-life care should be discussed early with the patient and carers, respecting the patient's social and cultural background.
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The aim of this study was to compare clinical and radiological outcome of lateral condyle fracture of the elbow in children treated with bioabsorbable or metallic material. From January 2008 to December 2009, 16 children with similar fractures and ages were grouped according to the fixation material used. Children were seen at 3, 6, and 12 months and more than 4 years (mean 51.8 months) postoperatively. The clinical results were compared using the Mayo Elbow Performance Score (MEPS). Radiographic studies of the fractured and opposite elbow were assessed at last follow-up control. Twelve children had a sufficient followup and could be included in the study. Seven could be included in the traditional group and 5 in the bioabsorbable group. At 12 months, the MEPS was 100 for every child in both groups. Asymptomatic bony radiolucent visible tracks and heterotopic ossifications were noted in both groups. There were no significant differences in terms of clinical and radiological outcome between the two groups. The use of bioabsorbable pins or screws is a reasonable alternative to the traditional use of metallic materials for the treatment of lateral condyle fracture of the elbow in children.
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BACKGROUND: Chronic lateral ankle instability accounts for 20% of the ankle injuries. This study evaluates functional outcome of the modified Broström-Gould technique using suture anchors, with 4 different clinical scores. METHODS: A consecutive series of 41 patients were included with a minimum follow-up of one year. The function was assessed using 4 clinical scores including: the AOFAS for hind foot; the FAAM; the CAIT and the CAIS. RESULTS: Out of 41 patients; 27 patients were very satisfied, 11 satisfied and 3 were not satisfied. Ankle mobility returned to normal in 93% of patients. At follow-up the AOFAS was 89/100 (37-100), the FAAM 85/100% (35-100%), the CAIT 20/30 (5-30), and the CAIS 74/100% (27-100%). CONCLUSION: Outcome of modified Broström-Gould procedure is good with high satisfaction rate in terms of ankle mobility. The disparity in outcome of scores, signals towards the need of a standard evaluation system.
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Ideally, reconstruction of lower extremity soft tissue defects includes not only an esthetically pleasing 3-dimensional shape and solid anchoring to the underlying structures to resist shear forces, but should also address the restoration of sensation. Therefore, we present a prospective study on defect reconstruction of the lower leg and ankle to evaluate the role of sensate free fasciocutaneous lateral arm flap and the impact of sensory nerve reconstruction. Thirty patients were allocated randomly to the study group (n = 15) that obtained end-to-side sensate coaptation using the lower lateral cutaneous brachial nerve to the tibial nerve using the epineural window technique, or to the control group reconstructed without nerve coaptation. At 1-year follow-up the patients were evaluated for pain sensation, thermal sensibility, static and moving 2-point discrimination, and Semmes-Weinstein monofilament tests. Data from both groups were compared and statistically analyzed with the Mann-Whitney U test and the Fisher exact test. Flaps of the study group reached a static and moving 2-point discrimination and Semmes-Weinstein monofilament tests nearly equal to the contralateral leg area and significantly better than flaps of the control group. Donor damage morbidity of the tibial nerve did not occur. To our point of view resensation should be carried out by end-to-side neurorrhaphy to the tibial nerve because of the superior restoration of sensibility.