The Electron Transport Through Strongly Coupled Double Quantum Dots : Effect of Spin Exchange Interaction

We introduce  model calculation for the electron transport through a system consists of two serially coupled quantum dots, embedded between two nonmagnetic leads (source and drain). In our treatment, the time independent Anderson-Newns Hamiltonian model is considered as a basis to study the system dynamics and then to derive spin-dependent analytical formula to calculate the occupation numbers of the quantum dots energy levels, the corresponding quantum dots energy levels and the molecular virtual energy levels, as a function of bias voltage. These relations are solved self-consistently, which are all employed to calculate the tunneling current considering the strong coupling regime. The differential conductance is calculated numerically by using finite differences method. And as the efficiency of electron transport through coupled quantum dots depends on the system parameters, the effective exchange energy is highlighted and studied in details and the role of this parameter in the tunneling current and the differential conductance calculations is presented. Our treatment is utilized to study the following The role of the spin exchange interaction in determining the type of  interaction (if it is attractive or repulsive) between the quantum dots...

ACHILLES Reading Guide 2: A deeper understanding of deterioration of engineered soils.

The engineering properties (e.g. strength,deformability, permeability) of the soils andcompacted fills that form the foundations forour infrastructure are known to change whenstresses are applied. These stresses can takethe form of increased traffic loading on aroad or rail line, or can be produced by thematerial shrinking and swelling as thematerial dries out in summer and becomessaturated in winter months. Whilst thesedrivers of deterioration are known [1,2] themechanisms through which the deteriorationoccurs is less well understood. To predicthow our infrastructure may deteriorate in thefuture it is important to understand theseprocesses. One of the aims of the ACHILLESteam has been to develop an improvedunderstanding of engineered soildeterioration at the material scale so we candetermine the magnitude of changes in soilproperties, estimate how long this processwill take and identify efficient means ofarresting this deterioration

A randomized controlled clinical trial evaluating the effect of Trigonella foenum-graecum (fenugreek) versus glibenclamide in patients with diabetes

Background: Herbal medicines long have been used in the management of diabetes mellitus (DM).Objective: This study was conducted to ascertain if fenugreek compared with glibenclamide had any impacts on controlling blood glucose in patients with uncontrolled type II DM on conventional therapy.Methods: A total of 12 patients with uncontrolled DM and on metformin were recruited and divided into two groups. Patients in group 1 received 2 g fenugreek per day, whereas those in group 2 received glibenclamide 5 mg once daily. The impacts of fenugreek on the glycemic control and lipid profile were measured before initiation of the regimen and then after 12 weeks.Results: Only 9 of the 12 study participants completed the study. Fenugreek at 2 g/day caused an insignificant drop in fasting blood glucose (P = 0.63), but the fasting insulin level increased significantly (P = 0.04). The ratio of high- to low-density lipopro- tein was significantly decreased from before to after treatment (P = 0.006). Fenugreek did not cause any notable adverse impacts on hepatic and renal functions throughout the study.Conclusion: Fenugreek could be used as adjuvant therapy to anti-diabetic drugs to control blood glucose, and further studies are needed.Keywords: Trigonella foenum-graecum (fenugreek), glibenclamide, diabetes

Cost-effectiveness of diagnostic-therapeutic strategies for paediatric visceral leishmaniasis in Morocco

Introduction Visceral leishmaniasis (VL) is a neglected parasitic disease with a high fatality rate if left untreated. Endemic in Morocco, as well as in other countries in the Mediterranean basin, VL mainly affects children living in rural areas. In Morocco, the direct observation of Leishmania parasites in bone marrow (BM) aspirates is used to diagnose VL and meglumine antimoniate (SB) is the first line of treatment. Less invasive, more efficacious and safer alternatives exist. In this study we estimate the cost-effectiveness of alternative diagnostic-therapeutic algorithms for paediatric VL in Morocco. Methods A decision tree was used to estimate the cost-effectiveness of using BM or rapid diagnostic tests (RDTs) as diagnostic tools and/or SB or two liposomal amphotericin B (L-AmB) regimens: 6-day and 2-day courses to treat VL. Incremental cost-effectiveness ratios, expressed as cost per death averted, were estimated by comparing costs and effectiveness of the alternative algorithms. A threshold analysis evaluated at which price L-AmB became cost-effective compared with current practices. Results Implementing RDT and/or L-AmB treatments would be cost-effective in Morocco according to the WHO thresholds. Introducing the 6-day course L-AmB, current second-line treatment, would be highly cost-effective if L-AmB price was below US$100/phial. The 2-day L-AmB treatment, current standard treatment of paediatric VL in France, is highly cost-effective, with L-AmB at its market price (US$165/phial). Conclusions The results of this study should encourage the implementation of RDT and/or short-course L-AmB treatments for paediatric VL management in Morocco and other North African countries

A randomized controlled clinical trial evaluating the effect of Trigonella foenum-graecum (fenugreek) versus glibenclamide in patients with diabetes

Background: Herbal medicines long have been used in the management of diabetes mellitus (DM). Objective: This study was conducted to ascertain if fenugreek compared with glibenclamide had any impacts on controlling blood glucose in patients with uncontrolled type II DM on conventional therapy. Methods: A total of 12 patients with uncontrolled DM and on metformin were recruited and divided into two groups. Patients in group 1 received 2 g fenugreek per day, whereas those in group 2 received glibenclamide 5 mg once daily. The impacts of fenugreek on the glycemic control and lipid profile were measured before initiation of the regimen and then after 12 weeks. Results: Only 9 of the 12 study participants completed the study. Fenugreek at 2 g/day caused an insignificant drop in fasting blood glucose (P = 0.63), but the fasting insulin level increased significantly (P = 0.04). The ratio of high- to low-density lipoprotein was significantly decreased from before to after treatment (P = 0.006). Fenugreek did not cause any notable adverse impacts on hepatic and renal functions throughout the study. Conclusion: Fenugreek could be used as adjuvant therapy to anti-diabetic drugs to control blood glucose, and further studies are needed. DOI: https://dx.doi.org/10.4314/ahs.v19i1.34 Cite as: Najdi RA, Hagras MM, Kamel FO, RM M. A randomized controlled clinical trial evaluating the effect of Trigonella foenum-graecum (fenugreek) versus glibenclamide in patients with diabetes. Afri Health Sci. 2019;19(1). 1594-1601. https://dx.doi.org/10.4314/ahs.v19i1.3

Burnout among postgraduate medical trainees in Lebanon: Potential strategies to promote wellbeing

ObjectiveBurnout is a widespread issue in healthcare for many years. Lebanon combatted political and economic crises before the coronavirus disease 2019 (COVID-19) pandemic, in addition to the port explosion in August 2020. The study aimed to identify the determinants of personal burnout, patient-related burnout, and work-related burnout among postgraduate medical trainees (PGMT) and evaluate its relationship with sociodemographic characteristics.DesignA cross-sectional study utilized the Copenhagen Burnout Inventory (CBI) involving electronic, voluntary, and anonymous survey. The survey was completed by 188 PGMT including residents and fellows from all specialties and all levels of training.ResultsThe prevalence rates are 68.6% for personal burnout, 63.3% for work-related burnout, and 35.1% for patient-related burnout.ConclusionResults improve our understanding of the phenomenon of burnout, and the role of program leadership in shaping the impact of burnout on training and promoting wellbeing of PGMT. Discussion focuses on providing potential wellbeing strategies for program directors to follow for mitigating burnout

Reproductive performance of native and imported dairy cows in the Tadla region (Morocco)

Parmi les performances de reproduction des vaches laitières dans la région du Tadla (Maroc) sur une période de 4 années, l’âge à la première insémination artificielle (IA) a été de 573,4 ± 35,6 jours et à l’âge au premier vêlage de 853,8 ± 103,5 jours, l’intervalle vêlage-1ère IA de 75,5 ± 35,6 jours. Celui-ci a été plus court chez les femelles importées que chez les natives. La race Montbéliarde a été inséminée plus tôt que la race Prim’Holstein. Le taux de réussite en 1ère IA a été de 53,2% avec de larges variations inter-annuelles et inter-élevages. Les Prim’holstein ont été mieux fécondées que les autres races. 18,2% des vaches ont nécessité 3 IA ou plus et l’indice coïtal a été de 1,8 ±1,3. La campagne, l’élevage et la race ont affecté significativement le taux de femelles ayant nécessité 3 IA ou plus. La race Prim’holstein française a manifesté un taux inférieur à celui de la race Prim’holstein canadienne. L’intervalle vêlage - insémination fécondante a été de 119,2 ± 83,8 jours. Ce paramètre a varié très significativement selon l’année, l’élevage, la race et le numéro de lactation. La race Montbéliarde a présenté undélai moyen de fécondation plus court que la race Prim’Holstein Canadienne

A Pycellerator Tutorial.

We present a tutorial on using Pycellerator for biomolecular simulations. Models are described in human readable (and editable) text files (UTF8 or ASCII) containing collections of reactions, assignments, initial conditions, function definitions, and rate constants. These models are then converted into a Python program that can optionally solve the system, e.g., as a system of differential equations using ODEINT, or be run by another program. The input language implements an extended version of the Cellerator arrow notation, including mass action, Hill functions, S-Systems, MWC, and reactions with user-defined kinetic laws. Simple flux balance analysis is also implemented. We will demonstrate the implementation and analysis of progressively more complex models, starting from simple mass action through indexed cascades. Pycellerator can be used as a library that is integrated into other programs, run as a command line program, or in iPython notebooks. It is implemented in Python 2.7 and available under an open source GPL license

Cooperative Binding

Molecular binding is an interaction between molecules that results in a stable association between those molecules. Cooperative binding occurs if the number of binding sites of a macromolecule that are occupied by a specific type of ligand is a nonlinear function of this ligand’s concentration. This can be due, for instance, to an affinity for the ligand that depends on the amount of ligand bound. Cooperativity can be positive (supralinear) or negative (infralinear). Cooperative binding is most often observed in proteins, but nucleic acids can also exhibit cooperative binding, for instance of transcription factors. Cooperative binding has been shown to be the mechanism underlying a large range of biochemical and physiological processes