Social orienting: Reflexive versus voluntary control

Many studies have shown that the direction of gaze of a face covertly facilitates the response to a target presented in the matching direction. In this study we seek to determine whether there exist separate reflexive and voluntary forms of such covert social orienting and how they interact with each other. We measured the effect of the predictive value of a gaze cue on manual choice reaction times. When the predictive value of the gaze cue was zero, a facilitatory cueing effect was still observed which peaked at a cue onset to target onset delay (CTD) of 150 ms and largely diminished beyond a CTD of 500 ms. When the gaze cue was 100% predictive of the future location of the target, at CTDs greater than 200, the predictive cue resulted in a significantly greater facilitation of response than occurred with a non-predictive cue. These results suggest that given enough time (about 200 ms), the social cue is interpreted and a willful or voluntary spatially-specific social cueing effect occurs. In addition, we found that a predictive cue resulted in a significant slowing of the observer’s responses up to a CTD of 200 ms. These findings show that, similar to non-social spatial orienting, there appear to be two forms of social orienting including a reflexive component and voluntary component. We suggest a model of social orienting in which the voluntary social orienting system modulates tonic inhibition of the reflexive social orienting system.     

An Optimistic Solver for the Mathematical Model of the Flow of Johnson Segalman Fluid on the Surface of an Infinitely Long Vertical Cylinder

In this paper, a novel soft computing technique is designed to analyze the mathematical model of the steady thin film flow of Johnson–Segalman fluid on the surface of an infinitely long vertical cylinder used in the drainage system by using artificial neural networks (ANNs). The approximate series solutions are constructed by Legendre polynomials and a Legendre polynomial-based artificial neural networks architecture (LNN) to approximate solutions for drainage problems. The training of designed neurons in an LNN structure is carried out by a hybridizing generalized normal distribution optimization (GNDO) algorithm and sequential quadratic programming (SQP). To investigate the capabilities of the proposed LNN-GNDO-SQP algorithm, the effect of variations in various non-Newtonian parameters like Stokes number (St), Weissenberg number (We), slip parameters (a), and the ratio of viscosities (ϕ) on velocity profiles of the of steady thin film flow of non-Newtonian Johnson–Segalman fluid are investigated. The results establish that the velocity profile is directly affected by increasing Stokes and Weissenberg numbers while the ratio of viscosities and slip parameter inversely affects the fluid’s velocity profile. To validate the proposed technique’s efficiency, solutions and absolute errors are compared with reference solutions calculated by RK-4 (ode45) and the Genetic algorithm-Active set algorithm (GA-ASA). To study the stability, efficiency and accuracy of the LNN-GNDO-SQP algorithm, extensive graphical and statistical analyses are conducted based on absolute errors, mean, median, standard deviation, mean absolute deviation, Theil’s inequality coefficient (TIC), and error in Nash Sutcliffe efficiency (ENSE). Statistics of the performance indicators are approaching zero, which dictates the proposed algorithm’s worth and reliability.     

Efficient Hybrid Nature-Inspired Binary Optimizers for Feature Selection

Cognitive Computation - The process of dimensionality reduction is a crucial solution to deal with the dimensionality problem that may be faced when dealing with the majority of machine learning...     

Penbactam for Helicobacter pylori eradication: A randomised comparison of quadruple and triple treatment schedules in an Iranian population

Background & study aimsSelection of the best drug regimens for eradication of Helicobacter pylori infection especially in patients at risk of peptic ulcer relapses and the development of complications is challenging. This study assessed and compared the efficacy of the two common PPI based triple therapies to a quadruple therapy including PPI, metronidazole, amoxicillin and a bismuth compound in Iranian population.Patients & MethodsThree hundred and thirty patients with peptic ulcer and H. pylori infection were included in the study. Patients were randomly assigned to one of the three treatment protocols all given twice daily: (a) A 14-day quadruple therapy (OMAB group) comprising omeprazole 20 mg, metronicazole 500 mg, amoxicillin 1 g, and bismuth subcitrate 240 mg; (b) A 14-day triple regimen (OCP group) comprising omeprazole 20 mg plus clarithromycine 500 mg and penbactam 750 mg and (c) A 14-day triple regimen (OCA group) comprising omeprazole 20 mg plus clarithromycine 500 mg and amoxicillin 1 g. Cure was defined as a negative urea breath test at least six weeks after treatment.ResultsThe per-protocol eradication rates achieved with both OCP regimen (87.0%) and OCA treatment (90.8%) were significantly higher than the OMAB treatment protocol (56.0%); however, no significant difference emerged in eradication rates between the two triple treatment schedules. No significant differences between the groups were found in most side-effects.ConclusionTwo-week quadruple therapy showed a lower eradication rate compared to common triple treatment schedules when used as first-line eradication treatment for H. pylori infection in Iranian population.     

Comparison of Salivary and Serum Soluble CD44 Levels between Patients with Oral SCC and Healthy Controls

Background: The most common type of oral cancer is oral squamous cell carcinoma. If it is diagnosed in the earlystages; the success of the treatment can be increased. It seems that ELISA-based techniques as a screening tool forsociety are the most cost-effective methods for early diagnosis. CD44 is a key marker for the detection of SCC stemcells. The aim of this study was to compare the level of soluble CD44 in saliva and serum between patients with oralSCC and healthy controls. Materials and Methods: Saliva and serum were collected from 20 patients with primaryOSCC and 20 healthy persons as control group. The samples were evaluated by an ELISA test kit. Data were analyzedby SPSS software version 22, chi-square, ANOVA, T-test and Spearman correlation test. Results: The mean of solubleCD44 level in serum and saliva of the patient and control groups are 531.51±228.95 and 453.3±113.74 (for serum)and 48.53±59.02 and 17.76±39.14 (for saliva) respectively. There was no statistically significant difference in serumand saliva solCD44 level between the patient and control groups (P value = 0.182 and P value = 0.061 respectively).Also, there was no significant correlation between the solCD44 level in each patient and control group in serum (Pvalue = 0.61) and in saliva (P value = 0.445). Conclusions: Determination of solCD44 level in saliva and serum canbe a useful method for diagnosis the person’s involvement with cancer cells and the cancer in the early stages. Butaccording to the controversial outcomes of past studies, larger and more accurate studies are needed in groups withmore cases of oral cancer.     

Prospective screening in liver transplant recipients by panfungal PCR-ELISA for early diagnosis of invasive fungal infections.

Invasive fungal infections after liver transplantation (LT) have resulted in high mortality and potentially fatal complications. This study was undertaken to determine the accuracy of the panfungal polymerase chain reaction enzyme link immunosorbent assay (PCR-ELISA) method in early diagnosis of invasive fungal infections in liver transplant recipients (LTRs). A total of 48 liver recipients (cadaver donors) were followed for fungal infections for a period of at least 6 months. All clinical samples were cultured and a direct microscopic examination was performed. Blood samples were cultured by bedside inoculation onto BACTEC medium. Whole blood specimens were collected prospectively once per week and were evaluated for any invasive fungal infections by panfungal PCR and PCR-ELISA. Among 48 transplant recipients between September 2004 and January 2006 (22 females, 28 males, mean age = 34.4 yr), 40 recipients (83.3%) had Candida colonization in different sites of their body before LT. In proven and probable recipients for panfungal PCR-ELISA, the sensitivity, specificity, and positive and negative predictive values were 83.3%, 91.7%, 76.9%, and 94.3%, respectively. By PCR assay, fungal infections were diagnosed in 10 recipients (20.8%). The mean interval time from transplantation to development of fungal infection was 61.4 days (range, 20-150 days) and time of infection in blood before any clinical signs was 7-70 days with mean of 21.4 days. The etiologic agents were Candida albicans (9 cases) and Aspergillus fumigatus (1 case). Use of PCR-ELISA in LTRs may not only improve the ability of early diagnosis of invasive fungal infections (IFIs) when positive results are obtained, but also would provide more confidence to exclude a diagnosis of IFIs when negative results are obtained.     

Simultaneous Feature Selection and Support Vector Machine Optimization Using the Grasshopper Optimization Algorithm

Support vector machine (SVM) is considered to be one of the most powerful learning algorithms and is used for a wide range of real-world applications. The efficiency of SVM algorithm and its performance mainly depends on the kernel type and its parameters. Furthermore, the feature subset selection that is used to train the SVM model is another important factor that has a major influence on it classification accuracy. The feature subset selection is a very important step in machine learning, specially when dealing with high-dimensional data sets. Most of the previous researches handled these important factors separately. In this paper, we propose a hybrid approach based on the Grasshopper optimisation algorithm (GOA), which is a recent algorithm inspired by the biological behavior shown in swarms of grasshoppers. The goal of the proposed approach is to optimize the parameters of the SVM model, and locate the best features subset simultaneously. Eighteen low- and high-dimensional benchmark data sets are used to evaluate the accuracy of the proposed approach. For verification, the proposed approach is compared with seven well-regarded algorithms. Furthermore, the proposed approach is compared with grid search, which is the most popular technique for tuning SVM parameters. The experimental results show that the proposed approach outperforms all of the other techniques in most of the data sets in terms of classification accuracy, while minimizing the number of selected features.     

Co-contraction patterns of trans-tibial amputee ankle and knee musculature during gait

ABSTRACT: BACKGROUND: Myoelectric control of upper extremity powered prostheses has been used clinically for many years, however this approach has not been fully developed for lower extremity prosthetic devices. With the advent of powered lower extremity prosthetic components, the potential role of myoelectric control systems is of increasing importance. An understanding of muscle activation patterns and their relationship to functional ambulation is a vital step in the future development of myoelectric control. Unusual knee muscle co-contractions have been reported in both limbs of trans-tibial amputees. It is currently unknown what differences exist in co-contraction between trans-tibial amputees and controls. This study compares the activation and co-contraction patterns of the ankle and knee musculature of trans-tibial amputees (intact and residual limbs), and able-bodied control subjects during three speeds of gait. It was hypothesized that residual limbs would have greater ankle muscle co-contraction than intact and able-bodied control limbs and that knee muscle co-contraction would be different among all limbs. Lastly it was hypothesized that the extent of muscle co-contraction would increase with walking speed. METHODS: Nine unilateral traumatic trans-tibial amputees and five matched controls participated. Surface electromyography recorded activation from the Tibialis Anterior, Medial Gastrocnemius, Vastus Lateralis and Biceps Femoris of the residual, intact and control limbs. A series of filters were applied to the signal to obtain a linear envelope of the activation patterns. A co-contraction area (ratio of the integrated agonist and antagonist activity) was calculated during specific phases of gait. RESULTS: Co-contraction of the ankle muscles was greater in the residual limb than in the intact and control limbs during all phases of gait. Knee muscle co-contraction was greater in the residual limb than in the control limb during all phases of gait. CONCLUSION: Co-contractions may represent a limb stiffening strategy to enhance stability during phases of initial foot-contact and single limb support. These strategies may be functionally necessary for amputee gait; however, the presence of co-contractions could confound future development of myoelectric controls and should thus be accounted for.