Serotonin Transporter Genotype Modulates the Effects of Dopamine Transporter Genotype on Learning from Positive and Negative Feedback

People vary in their learning from positive or negative feedback. Feedback-based learning is modulated by two main neuromodulators, dopamine and serotonin. Dopamine is a key player in positive feedback processing, where it promotes behavioral activation to seek reward. Serotonin has been linked to negative feedback processing and behavioral inhibition. Dopamine and serotonin levels are regulated in the brain by transporters; the dopamine transporter (DAT) and serotonin transporter (SERT), which are encoded by DAT1 gene and SLC6A4 gene, respectively. Evidence implies that serotonin regulates dopamine release, since dopamine function in reward processing, while serotonin is exhibits behavioral inhibitor which suppresses behavior. The cognitive effects of the interaction between dopamine and serotonin remain to be elucidated. In this study, we are pursuing a multidisciplinary approach to study the molecular and cognitive effects of the interaction of naturally- occurring polymorphisms; the 3′-UTR of the DAT1 gene, a variable number tandem repeat (VNTR) which controls the expression of DAT, and the STTP in the SLC6A4 gene which regulates the expression of SERT mRNA. Also, we will construct a neurocomputational model to study the interactions between dopamine and serotonin in feedback-based learning. We recruited a sample of 450 healthy participants from Al-Quds University. All participants completed a probabilistic categorical feedback-based learning task that differentiates learning from positive and negative feedback. Our results suggest that genes that modulate dopamine and serotonin levels affected reward learning but not punishment learning. When we held SLC6A4 constant and varied DAT1 genotypes, there was better learning from both reward and punishment with higher dopamine levels (9-repeat carriers) in the context of higher serotonin levels (short allele carriers). Conversely, there was no difference between DAT1 genotypes in learning from positive and negative feedback in the context of low serotonin levels (long allele homozygotes). When we held DAT1 genotypes constant, there were no differences between SLC6A4 genotypes in the context of high (9-repeat carriers) or low (10-repeat homozygotes) dopamine levels. These findings argue in favor of a modulatory role of serotonin on dopamine function. Future studies will investigate this gene-gene interaction in Parkinson’s disease and Major Depressive Disorder as it relates to cognitive function and response to treatment

A general cohesive continuum mechanics framework for constitutive modeling of microdamage healing

This study extends a recently developed [1, 2] general continuum damage mechanics-based framework to model the microdamage healing phenomenon in self-healing materials. The well-known nominal, healing and effective configurations of classical continuum damage mechanics are extended to self-healing materials. The theory of mixtures is used to estimate the elastic stiffness in the healed portions of the damaged material which is assumed to be different than the elastic stiffness of the intact material. Therefore, a new physically based state variable (i.e., healing variable) is defined based on the elastic stiffness to enrich the classical continuum damage mechanics theories in modeling the microdamage healing phenomenon. The well-known transformation hypotheses of the continuum damage mechanics (i.e., strain equivalence, elastic strain energy equivalence, and power equivalence hypotheses) are used to incorporate the effects of the microdamage healing in self-healing materials. Analytical relations are derived to relate elastic stiffness moduli in the nominal, healing and effective configurations for each postulated transformation hypothesis. The cohesive zone model presented in Ref. [3] is extended to incorporate the microdamage healing effects. The effects of heat and resting time on the healing behavior of the material are discussed. A general thermodynamic framework for constitutive modeling of damage and microdamage healing mechanisms is used to derive the evolution equations for the healing state variables. The ability of the proposed model to explain microdamage healing is demonstrated by presenting several examples and by comparing the model predictions and experimental data on a self-healing material. REFERENCES [1] Abu Al-Rub, R.K., Darabi, M.K., Little, D., Masad, E.A.. A micro-damage healing model that improves prediction of fatigue life of asphalt mixes. Int. J. Engng. Sci. 2010, 48(11), 966‑990. [2] Darabi, M.K., Abu Al-Rub, R.K., Little, D.N. A continuum damage mechanics framework for modeling micro-damage healing. Int. J. Solids Structures. 2012, 49(3‑4), 492‑513. [3] Abu Al-Rub, R.K., Palazotto, A.N. Micromechanical theoretical and computational modeling of energy dissipation due to nonlinear vibration of hard ceramic coatings with microstructural recursive faults. Int. J. Solids Structures. 2010, 47, 2131‑2142

The Impact of Strategy of Dramatizing the Curricula in Developing Reading Comprehension Skills and Oral Language Ability among Third Grade students

ملخص: هدفت الدراسة الى تقصي أثر استراتيجية مسرحة المناهج في تنمية مهارات استيعاب المقروء والقدرة اللغوية الشفوية لدى طلاب الصف الثالث الابتدائي، واتبعت الدراسة منهج البحث شبه التجريبي، حيث يعدّ منهجا مناسبا لتحقيق أهدافها. بلغ عدد المشاركين في الدراسة (65) طالبا، بواقع (33) طالبا في المجموعة التجريبية، و(32) طالبا في المجموعة الضابطة. تم اعداد أداتين للدراسة الحالية، وهما: اختبار في مهارات استيعاب المقروء، واقتصر اختبار استيعاب المقروء على المستويين الحرفي، وبعض جوانب المستوى الاستنتاجي، التي تقع ضمن مستوى طلبة الصف الثالث الابتدائي، واختبار في القدرة اللغوية الشفوية، وتضمن اختبار القدرة اللغوية الشفوية مجالي الشكل والمضمون، اللذين جرى تصحيحهما وفقا لمعايير الشكل والمضمون. أظهرت نتائج الدراسة وجود أثر ذي دلالة إحصائية لاستراتيجية مسرحة المناهج في تنمية مهارات استيعاب المقروء، والقدرة اللغوية الشفوية. وفي ضوء هذه النتائج أوصت الدراسة بضرورة تدريب معلمي الصفوف الثلاثة الأولى والمشرفين على كيفية تدريس اللغة العربية باستراتيجية مسرحة المناهج.Abstract: : The study aimed to investigate the impact of strategy of dramatizing the curricula in developing reading comprehension skills and oral language ability among third graders. The study followed a quasi-experimental approach, as an appropriate approach to achieve its objectives. The study sample was included (65) students, with (33) students in the experimental group and (32) students in the control group. Two instruments were used: a test in reading comprehension skills, and a test in oral linguistic ability, which have been corrected according to observation card with the standards of form and content. The results showed that there was a statistically significant effect of the strategy of dramatizing the curricula in developing reading comprehension skills and oral language ability. The study recommended the need to inform the teachers of third graders and the supervisors of Arabic language on how to teach this language with the dramatized method

Lipase-catalysed synthesis and optimization of biologically active amides of cinnamic acid derivatives

Natural products compounds are very important source of materials for the pharmaceutical industry. Amides are in general present in natural products. Amides play an essential role in virtually all biological processes such as enzymatic catalysis and medical chemistry. Natural products which contain amide group play an important role in modern drug discovery, especially in cancer treatment. The extracts from Litsea plants have been reported to have significant cytotoxic activity against human tumor cells. The compounds which are the major components of Litsea plants are so valuable and important to be synthesized and studied. Litsea plant consists of many cinnamic acid amides. There are no suggested methods for the synthesis of Ntrans-sinapoylmethoxytyramine and N-trans-sinapoyldimethoxytyramine. The compounds N-trans-feruloylmethoxytyramine, N-trans-sinapoyltyramine and Ntrans-feruloyldimethoxytyramine have only one method for synthesis with a low yield. N-trans-feruloyltyramine needs hydrazine as a reagent which is very dangerous. The extraction method gives very low yield and the process is not economic. Thus, it is important to find a new direct method to synthesize these compounds. Six cinnamic acid amides derivatives were successfully synthesized from the reaction of cinnamic acids with tyramine derivatives in a one-step lipasecatalyzed reaction. The use of immobilized lipase, Lipozyme TL IM as the catalyst in the reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. All the amides were characterized using Fourier transform infrared (FTIR)spectroscopy, proton nuclear magnetic resonance (1H NMR) and carbon-13 (13C NMR) techniques. The optimized percentage yield obtained was 93.5 % when the process was carried out for 48 h, at molar ratio of tyramine HCl: cinnamic acid - 1:6 at 40 ºC. Enzymatic synthesis of N-trans-feruloyltyramine was optimized by Response Surface Methodology (RSM) using 4-hydroxy-3-methoxycinnamic acid and tyramine hydrochloride in a one-step lipase catalyzed reaction using Lipozyme TL IM. RSM based on five-level, four-variable central composite rotatable design (CCRD) was used to evaluate the interactive synthesis with variables consisting of reaction time (24-96 h), temperature (30-50 ºC), amount of enzyme (2.5-25 mg/mL)and substrate molar ratio [cinnamic acid:tyramine HCl, (1:1 - 8:1 mmol)] on the percentage yield of N-trans-feruloyltyramine. The optimum conditions derived via RSM were; reaction time, 52 h, temperature, 43 ºC, amount of enzyme, 13 mg/mL and substrate molar ratio (cinnamic acid:tyramine HCl) 6.2:1. The actual experimental yield was 96.3 % under the optimum condition, which compared well to the maximum predicted value of 97.2 %. The anticancer activities for all compounds were evaluated against human colorectal (HT-29), human estrogen-receptor positive breast cancer (MCF-7), human estrogenreceptor negative breast cancer (MDA-MB-231) and human hepatocellular carcinoma (HepG2) cell lines. It can be concluded that all the amides normalized the rate of cell growth. The antibacterial properties of the synthesized amide compounds were evaluated on gram negative bacteria, gram positive bacteria and yeast. It was found that all synthesized amides inhibited the growth of the tested bacteria and yeasts with good zone diameter. N-trans-Sinapoyldimethoxytyramine inhibited the growth of the tested gram negative with 24 mm zone. N-trans-Sinapoyltyramine inhibited the growth of the tested gram positive MRSA and yeast CA with 30 mm and 40 mm zone, respectively against the corresponding microorganisms. Antioxidant activities were studied for all the compounds using DPPH and ATBS methods. In both methods, all compounds showed potential activity. N-transsinapoylmethoxytyramine showed the highest effective activity for all the compounds. DPPH Inhibition Ratio (%) was at 69.2 % and ABTS Inhibition Ratio (%) at 79.6 %. In addition, N-trans-feruloyldimethoxytyramine showed relatively lower activity with DPPH Inhibition Ratio (%) at 59.4 % and ABTS Inhibition Ratio (%) at 72.0 %. However, these results are considered as good antioxidant activity. Kinetic study using Lipozyme TL IM in the amidation of cinnamic acid with tyramine HCl was carried out. The effect of both substrates on the initial reaction rate was studied. The initial rates of the reaction were calculated and the results showed that the amidation reaction obeyed the Ping-Pong Bi-Bi mechanism. Lineweaver-Burk plots of amidation reaction were determined. The kinetic constants of reaction were studied whereby Vmax (mmol/L/min) was 0.0328 and Km (CA)(mmol/L) was 0.8955

ADSORPTION OF FOOD COLORING ALLURA RED DYE (E129) FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON

The adsorption behavior of Allura red (E129) from aqueous solutions onto activated carbon was successfully investigated. All factors affecting the adsorption process were carefully studied and the conditions were optimized. Adsorption of E129 onto activated carbon was found to increase by decreasing the mass of activated carbon, pH and ionic strength of the solution and by increasing temperature. The adsorption capacity of the activated carbon for Allura red was relatively high. Under the optimum conditions, the maximum adsorption capacity for E129 dye was 72.85 mg/g. Three adsorption models; Langmuir, Freundlich and Temkin model were investigated regarding the adsorption of E129. The models’ parameters KL, qm, R2, (n) were determined and found to be 0.0222, 72.85 mg/g, 0.9057-0.9984, and 0.992, respectively. Also, pseudo first and second-order kinetic models were tested to determine the best-fit model to the adsorption of E129 dye onto activated carbon. The results showed that the adsorption of E129 onto activated carbon obeyed both the Freundlich isotherm and pseudo second-order kinetic models. Moreover, thermodynamic studies indicated that the adsorption of E129 dye onto the activated carbon was spontaneous.Â

Symmetry properties of the nodal superconductor PrOs4Sb12

We present a theoretical study of the superconducting gap function in PrOs4Sb12 using a symmetry-based approach. A three-component order parameter in the triplet channel best describes superconductivity. The gap function is non-degenerate and the lower branch has four cusp nodes at unusual points of the Fermi surface, which lead to power law behaviours in the density of states, specific heat and nuclear spin relaxation rate.Comment: to appear in Phys. Rev. B 7

Impurity induced density of states and residual transport in nonunitary superconductors

We obtain general expressions for the residual density of states, electrical conductivity and thermal conductivity for non-unitary superconductors due to impurity scattering. We apply the results to the so-called `B phase' of PrOs4Sb12, which we describe using a non-unitary gap function derived from symmetry considerations. The conductivity tensor has inequivalent diagonal components due to off-axis nodal positions which may be detectable in experiments.Comment: 8 pages, 1 figur

Do it Right: Appropriate Ways for Teachers to Treat and React to Aggressive Children in Jordanian Kindergartens

This study explored the types and causes of aggression and the ways teachers treat and react to aggressive children in Jordanian kindergartens in the Irbid district. The sample consisted of the first 20 teachers who responded to the letter of participation sent to them.  Data on the causes and types of aggression and prevention strategies were collected by descriptive qualitative design, with semi-structured open-ended interviews, as well as observation of Jordanian kindergarten teachers. The results of the study revealed three themes: factors that shape aggression, sanctions rather than punishment and social learning and culture. Also, the results indicated that social learning through positive modelling was mostly needed to help aggressive and disruptive students and change their behaviour. In light of the results, further research utilizing quantitative and qualitative research methods to achieve broader understanding of aggression in pre-school settings is recommended

Superconducting gap nodes in PrOs_4Sb_12

We examine the superconducting gap nodes in crystals with tetrahedral (T_h) symmetry. The (0,0,1) phase of the three dimensional order parameter in the triplet channel has nodes in the [001] directions. Following a second order phase transition to the state (0,i|eta_2|,|eta_1|), each node lifts away from the Fermi surface and splits into two deep dips. We discuss this scenario in the context of multiple superconducting phases in PrOs4Sb12.Comment: 2 pages, 1 figure, ICM2006, manuscript with higher quality figure may be obtained at http://www.physics.mun.ca/~curnoe/papers/PrOs4Sb12.pd