Characterizing Goal-Directed Behavior in Children with Attention-Deficit/Hyperactivity Disorde

Attention-deficit hyperactivity disorder (ADHD) is characterized by symptoms of inattention, impulsivity and hyperactivity. Children with ADHD show impaired motivational behavior. For example, they tend to select small, immediate over large, delayed rewards. They might be unable to predict the consequences of their actions showing a deficit in action-control strategies. Goals and habits are the two behavioral mechanisms that control actions. Balancing these two behaviors leads to normal action-control. In previous studies, we found that rat models of ADHD demonstrated over-reliance on habits and poor goal-directed actions. This deficit was restored by administering methylphenidate (the most commonly used psychostimulant in ADHD treatment), dopamine D2 receptor agonist or dopamine D1 receptor antagonist. Further, in another pilot study, we found that children with ADHD are less reliant on goal-directed behavior compared to healthy children. In this study, we examined action-control patterns in children with ADHD on- and off- methylphenidate. We hypothesize that on-methylphenidate patients will show different patterns of action-control compared to off-methylphenidate patients. We tested 7 off-medication and 7 on-medication, 6-10 years old children with ADHD, and 13 healthy controls. Participants were 6-10 years old and were group matched for age and sex. We tested patterns of action-control using a computer-based task of the outcome devaluation paradigm that consists of three phases; a training phase, a devaluation phase and a choice test. Children with ADHD were successful at acquiring action-outcome associations as well as showing higher tendency on goal-directed responses. However, throughout the task, on- methylphenidate children showed (1) lower number of errors, (2) higher reaction times and (3) no difference in action-control responses (goals vs. habits). These results indicate that methylphenidate was beneficial in modulating symptoms of ADHD by reducing the number of errors during learning and increasing children’s response times; but it was not effective in improving children’s cognitive profile, reflected by similar action-control patterns in both on and off-medication states

Efeito da aplicação de alguns herbicidas à pré-emergência sobre a nodulação, a fixação de nitrogênio e o crescimento da soja

Aretit at the recommended rate (XI) and treflan, especially at high concentration (x 5 folds), stimulated nodulation of soybean 'Clark', while planavin, cobex or linuron, especially at high concentration inhibited nodule formation and even, in some instances, prevented plant growth. In all herbicidal treatments, the dry matter content of whole plant on the second harvest (92 days or pod filling) was lower, even those which showed stimulation at the first harvest (49 days or full bloom) than the control; the yields of pods obtained on maturity were also lower. In general, total-N contents of shoots, roots and pods as well as yield of total-N seemed to be affected by the application of herbicides. The effect differed according to herbicides concentration and growth stages of the plant. Nitrogenase activity as a measure of biological fixation of atmospheric nitrogen using the acetylene-reduction technique was also carried out for root nodules to investigate effect of aretit or treflan on the symbiotic N-fixation processes. The dehydrogenase (DHA) activity in nodule homogenate was also determined in presence or absence of succinate, citrate or ethanol to investigate the effect of herbicidal treatments on respiratory chain of bacteroids. This was claimed to thraw light on effect of herbicidal treatments on capacity of the legume plant (soybean 'Clark') to supply the symbiont (R. japonicum) in the root nodules with some products (hydrogen doners) of the Kreb's cycle and consequently thus affects nitrogen fixation efficiency of root nodules.O aretit na dose recomendada (x1), e o treflan, mormente em alta concentração (5 dobras), estimularam a nodulação da soja ‘Clark'. O planavin ou o linuron, mormente em alta concentração, inibiram a formação de nódulos e, em certos casos, até anteciparam o crescimento da planta. Em todos os tratamentos com herbicidas, a quantidade de matéria seca na segunda colheita (92°. dia, período de enchimento da vagem) foi menor do que na testemunha, mesmo em se tratando de plantas que mostraram estimulação na primeira colheita (49°. dia, plena floração). Também as produções de vagens foram menores. Em geral, parece que os conteúdos de N-total dos brotos, raízes e vagens e a própria produção de N-total são favorecidos com o uso de herbicidas. O efeito diferiu de acordo com o grau de concentração dos herbicidas e de acordo também com o estádio de desenvolvimento da planta. Para investigar o efeito do aretit ou do treflan sobre os processos simbióticos de fixação de nitrogénio, foi efetuada, para os nódulos radiculares, no 49°. e 92°. dias, a atividade de nitrogenase, como medida de fixação biológica de nitrogênio atmosférico. Também foi efetuada a atividade de deidrogenase (DHA) em nódulo homogeneizado, em presença ou ausência de succinato, citrato, ou etanol, para investigação do efeito dos tratamentos com herbicidas na corrente respiratória dos bacteroides. Ela foi necessária para se esclarecer o efeito dos tratamentos com herbicidas sobre a capacidade da soja ‘Clark’ de fornecer o simbionte (R. japonicum) nos nódulos radiculares com alguns produtos (doadores de hidrogênio) do ciclo Kreb e, consequentemente, de tornar mais eficiente a fixação de nitrogênio por parte dos nódulos radiculares

Time-Fractional KdV Equation: Formulation and Solution using Variational Methods

In this work, the semi-inverse method has been used to derive the Lagrangian of the Korteweg-de Vries (KdV) equation. Then, the time operator of the Lagrangian of the KdV equation has been transformed into fractional domain in terms of the left-Riemann-Liouville fractional differential operator. The variational of the functional of this Lagrangian leads neatly to Euler-Lagrange equation. Via Agrawal's method, one can easily derive the time-fractional KdV equation from this Euler-Lagrange equation. Remarkably, the time-fractional term in the resulting KdV equation is obtained in Riesz fractional derivative in a direct manner. As a second step, the derived time-fractional KdV equation is solved using He's variational-iteration method. The calculations are carried out using initial condition depends on the nonlinear and dispersion coefficients of the KdV equation. We remark that more pronounced effects and deeper insight into the formation and properties of the resulting solitary wave by additionally considering the fractional order derivative beside the nonlinearity and dispersion terms.Comment: The paper has been rewritten, 12 pages, 3 figure

Effects of Social Media Use on Psychological Well-Being: A Mediated Model

The growth in social media use has given rise to concerns about the impacts it may have on users' psychological well-being. This paper's main objective is to shed light on the effect of social media use on psychological well-being. Building on contributions from various fields in the literature, it provides a more comprehensive study of the phenomenon by considering a set of mediators, including social capital types (i.e., bonding social capital and bridging social capital), social isolation, and smartphone addiction. The paper includes a quantitative study of 940 social media users from Mexico, using structural equation modeling (SEM) to test the proposed hypotheses. The findings point to an overall positive indirect impact of social media usage on psychological well-being, mainly due to the positive effect of bonding and bridging social capital. The empirical model's explanatory power is 45.1%. This paper provides empirical evidence and robust statistical analysis that demonstrates both positive and negative effects coexist, helping to reconcile the inconsistencies found so far in the literature

Total quality management practices, competitive strategies and financial performance: the case of the Palestinian industrial SMEs

"This is an Accepted Manuscript of an article published by Taylor & Francis in Total Quality Management and Business Excellence on 19 Aug 2013, available online: http://wwww.tandfonline.com/10.1080/14783363.2013.824714."The purpose of this paper is to examine the relationship between Total Quality Management (TQM) practices, competitive strategies - cost leadership and differentiation- and firm performance in the Palestinian economy. Within this study total quality management has been conceptualized as soft and hard practices, in congruence with the literature. An empirical analysis based upon an extensive validation process was applied to refine TQM, competitive strategies and financial performance scales. Data were collected through surveying 202 in Palestinian industrial small and medium enterprises (SMEs). Structural Equation Modeling was carried out to test the anticipated relationships. Results derived from this study show that TQM practices have indirect, positive and significant relationship with financial performance through competitive strategies. In addition, a direct, positive and significant relationship between competitive strategies and financial performance was observed. Results derived from this study might help managers to implement TQM practices in order to effectively allocate resources and improve financial performance

Traditional knowledge of wild edible plants used in Palestine (Northern West Bank): A comparative study

<p>Abstract</p> <p>Background</p> <p>A comparative food ethnobotanical study was carried out in fifteen local communities distributed in five districts in the Palestinian Authority, PA (northern West Bank), six of which were located in Nablus, two in Jenin, two in Salfit, three in Qalqilia, and two in Tulkarm. These are among the areas in the PA whose rural inhabitants primarily subsisted on agriculture and therefore still preserve the traditional knowledge on wild edible plants.</p> <p>Methods</p> <p>Data on the use of wild edible plants were collected for one-year period, through informed consent semi-structured interviews with 190 local informants. A semi-quantitative approach was used to document use diversity, and relative importance of each species.</p> <p>Results and discussion</p> <p>The study recorded 100 wild edible plant species, seventy six of which were mentioned by three informants and above and were distributed across 70 genera and 26 families. The most significant species include <it>Majorana syriaca, Foeniculum vulgare, Malvasylvestris</it>, <it>Salvia fruticosa, Cyclamen persicum, Micromeria fruticosa, Arum palaestinum, Trigonella foenum-graecum</it>, <it>Gundelia tournefortii</it>, and <it>Matricaria aurea</it>. All the ten species with the highest mean cultural importance values (mCI), were cited in all five areas. Moreover, most were important in every region. A common cultural background may explain these similarities. One taxon (<it>Majoranasyriaca</it>) in particular was found to be among the most quoted species in almost all areas surveyed. CI values, as a measure of traditional botanical knowledge, for edible species in relatively remote and isolated areas (Qalqilia, and Salfit) were generally higher than for the same species in other areas. This can be attributed to the fact that local knowledge of wild edible plants and plant gathering are more spread in remote or isolated areas.</p> <p>Conclusion</p> <p>Gathering, processing and consuming wild edible plants are still practiced in all the studied Palestinian areas. About 26 % (26/100) of the recorded wild botanicals including the most quoted and with highest mCI values, are currently gathered and utilized in all the areas, demonstrating that there are ethnobotanical contact points among the various Palestinian regions. The habit of using wild edible plants is still alive in the PA, but is disappearing. Therefore, the recording, preserving, and infusing of this knowledge to future generations is pressing and fundamental.</p

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised