Metastable Features of Economic Networks and Responses to Exogenous Shocks

It has been proved that network structure plays an important role in addressing a collective behaviour. In this paper we consider a network of firms and corporations and study its metastable features in an Ising based model. In our model, we observe that if in a recession the government imposes a demand shock to stimulate the network, metastable features shape its response. Actually we find that there is a minimum bound where demand shocks with a size below it are unable to trigger the market out from recession. We then investigate the impact of network characteristics on this minimum bound. We surprisingly observe that in a Watts-Strogatz network though the minimum bound depends on the average of the degrees, when translated into the economics language, such a bound is independent of the average degrees. This bound is about $0.44 \Delta$GDP, where $\Delta$GDP is the gap of GDP between recession and expansion. We examine our suggestions for the cases of the United States and the European Union in the recent recession, and compare them with the imposed stimulations. While stimulation in the US has been above our threshold, in the EU it has been far below our threshold. Beside providing a minimum bound for a successful stimulation, our study on the metastable features suggests that in the time of crisis there is a "golden time passage" in which the minimum bound for successful stimulation can be much lower. So, our study strongly suggests stimulations to be started within this time passage.Comment: 13 pages, 10 figures, accepted for publication in PloS On

Empirical Coordination in a Triangular Multiterminal Network

In this paper, we investigate the problem of the empirical coordination in a triangular multiterminal network. A triangular multiterminal network consists of three terminals where two terminals observe two external i.i.d correlated sequences. The third terminal wishes to generate a sequence with desired empirical joint distribution. For this problem, we derive inner and outer bounds on the empirical coordination capacity region. It is shown that the capacity region of the degraded source network and the inner and outer bounds on the capacity region of the cascade multiterminal network can be directly obtained from our inner and outer bounds. For a cipher system, we establish key distribution over a network with a reliable terminal, using the results of the empirical coordination. As another example, the problem of rate distortion in the triangular multiterminal network is investigated in which a distributed doubly symmetric binary source is available.Comment: Accepted in ISIT 201

Pathological study of parasitism in racing pigeons: An indication of its effects on community health

Several non-official reports from different clinics, governmental veterinary head-quarters and bird keepers indicate that most of the young pigeons die with suspicious infection to parasites. In addition, the pigeon owners were complaining of skin itching on their head. Thus, this research was conducted to determine the pathological study of parasitism in racing pigeons with an indication of its effects on community health. It was carried out from May to September 2011, by an experimental study on 250 (168 adults and 82 nestlings) blood and faecal samples (Soulsby, 1982) randomly collected from suspected pigeons (mostly young) and 25 specific free pathogen birds as control. Tissue samples of both infected and control birds were removed and compared with samples of the histological study. Moreover, 12 hair samples taken from pigeon owners were checked for external parasites. The data indicate prevalence rate of various helminthes including Raillietina achinobothridia (10.4%), Syngamus trachea (8.4%), Capillaria colombae (6%) and Ascaridia colombae (8.4%). The results reveal some porotozan infections including Haemoproteus colombae (20.8%), Trichomonas gallinae (26.8%) Cryptosporidium sp. (1.2%) and Eimeria sp. (21.6%) and also ectoparasites including Lipeurus sp. (3.2%), Menopen gallinae (15.2%), Ceratophyllus colombae (10.4%) and Louse fly (12%). Multiple infections observed with internal parasites were 19/4%. However, co-infection of internal and external parasites was 24.4%. Meanwhile, five out of the 12 hair samples taken from pigeon owners were infected with the fleas (C. colombae) and lice (M. gallinae) as seen by the clinical manifestation of allergic urticarial reaction and itching. Histological studies showed a visible vascular congestion and a massive lymphoplasmacytic infiltration inside the smooth muscular layer of the small intestine of infected pigeons. This result indicates that pigeons and their owners may be at high risk of single or multiple parasitic infections.Key words: Endoparasite, ectoparasites, ovum, birds, fleas, epidemiology

Nano Graphene Oxide as Solid Phase Extraction Adsorbent Coupled with Dispersive Liquid-Liquid Microextraction to Determine Ultra-Trace Quantities of Propranolol from Urine Samples

In this research, a new nano graphene oxide based solid phase extraction followed by Dispersive Liquid-Liquid Microextraction was applied as simple, rapid and sensitive determination of trace amounts of Propranolol(PRO) in urine samples with HPLC-UVD. Several factors influencing the extraction of PRO, such as pH, adsorbent amounts, extraction time, organic solvent type and the composition of solvent and desorption conditions were studied and optimized. Under optimum condition, the limit of detection (LOD) and limit of quantification (LOQ) of the proposed method were 2ng/mL?1 and 6.6ng/mL, respectively. Good linear behaviour over the investigated concentration ranges (2-2000ng/mL-1) and good correlation coefficient of 0.9901(r2) were obtained. The relative standard deviations (RSDs) based on three determinations at 2, 20, 200ng/mL-1 levels of PRO was less than 9.7%. The findings of the present study may provide clinical and diagnostic laboratories. &nbsp

Methodology for artificial microswimming using magnetic actuation

We propose a methodology for swimming at low-Reynolds-number flows based on ciliary motion of a microswimmer using magnetic actuation of artificial cilia.By solving the coupled magnetic-elastic-hydrodynamic problem, we demonstrate nonreciprocal effective and recovery strokes for cilia that nicely mimic natural cilia beating. Cilia drag forces, microswimmer net displacement, velocity, and efficiency are calculated, and we show the model can swim using a prespecified magnetic actuation. The proposed methodology can be used for devising biomedical microdevices that swim in viscous flows inside the human body

Effect of progressive muscle relaxation program on self-efficacy and quality of life in caregivers of patients with multiple sclerosis

Background: MS is a disease of the central nervous system affecting all economic, financial, social, and emotional aspects of individual, family, and community. Performing continuous care leads to chronic stress in caregivers of patients and this in turn threatens their self-efficacy and quality of life. Objective: The aim of the present study was to determine the effect of progressive muscle relaxation on self-efficacy and quality of life in caregivers of patients with multiple sclerosis. Methods: This was a controlled clinical trial in which 70 family caregivers of MS patients were investigated. The study population was divided into two age- and sex-matched case and control groups. Progressive muscle relaxation techniques were employed for the case group for three months (90 sessions) and its application was followed using a self-report checklist. After three months, selfefficacy and quality of life questionnaires were re-filled by members of both groups. Data were analyzed using descriptive and presumption statistical tests while a p≤0.05 was considered as significant. Findings: Paired t-test showed a significant difference in self efficacy and quality of life for family caregivers of case group three months after intervention (p=0.001). On the contrary, no significant difference regarding the efficacy and quality of life in family caregivers of MS patients in control group was found (P≥0.05). Conclusion: Several interventions such as progressive muscle relaxation program with low cost, good safety and effect can help reduce the stress of family caregivers of patients in particular those with chronic diseases such as multiple sclerosis and thus leading to an increase in their self-efficacy, care quality, and quality of life

FIM: A fatigued-injured muscle model based on the sliding filament theory

Skeletal muscle modeling has a vital role in movement studies and the development of therapeutic approaches. In the current study, a Huxley-based model for skeletal muscle is proposed, which demonstrates the impact of impairments in muscle characteristics. This model focuses on three identified ions: H + , inorganic phosphate Pi and Ca 2+. Modifications are made to actin-myosin attachment and detachment rates to study the effects of H + and Pi. Additionally, an activation coefficient is included to represent the role of calcium ions interacting with troponin, highlighting the importance of Ca 2+. It is found that maximum isometric muscle force decreases by 9.5% due to a reduction in pH from 7.4 to 6.5 and by 47.5% in case of the combination of a reduction in pH and an increase of Pi concentration up to 30 mM, respectively. Then the force decline caused by a fall in the active calcium ions is studied. When only 15% of the total calcium in the myofibrillar space is able to interact with troponin, up to 80% force drop is anticipated by the model. The proposed fatigued-injured muscle model is useful to study the effect of various shortening velocities and initial muscletendon lengths on muscle force; in addition, the benefits of the model go beyond predicting the force in different conditions as it can also predict muscle stiffness and power. The power and stiffness decrease by 40% and 6.5%, respectively, due to the pH reduction, and the simultaneous accumulation of H + and Pi leads to a 50% and 18% drop in power and stiffness

Fostering employee creativity through creativity-contingent extrinsic and intrinsic rewards that emphasise creativity: A systematic review of creativity academic papers

Creativity is widely believed to be necessary to increase quality performance. Thus, in today’s more challenging and competitive environment, the contemporary organization frequently utilizes rewards practices to stimulate creative activities among employees. Existing research on reward practices shows evidence that creativity contingent rewards play a vital role in improving employee creative performance. This study presents a systematic review of extrinsic and intrinsic rewards that contribute to creativity and their effect on employee creativity. The findings show that regardless of the degree of importance of the rewards perceived by the employee, both the extrinsic and intrinsic rewards were positively correlated with the behaviour of creativity behavior. Interestingly, the results showed that creativity-contingent intrinsic rewards have relatively stronger effects on employee creativity when compared to creativity-contingent extrinsic rewards