216 research outputs found

    Non-linear Fractional-Order Chaotic Systems Identification with Approximated Fractional-Order Derivative based on a Hybrid Particle Swarm Optimization-Genetic Algorithm Method

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    Although many mathematicians have searched on the fractional calculus since many years ago, but its application in engineering, especially in modeling and control, does not have many antecedents. Since there are much freedom in choosing the order of differentiator and integrator in fractional calculus, it is possible to model the physical systems accurately. This paper deals with time-domain identification fractional-order chaotic systems where conventional derivation is replaced by a fractional one with the help of a non-integer derivation. This operator is itself approximated by a N-dimensional system composed of an integrator and a phase-lead filter. A hybrid particle swarm optimization (PSO) and genetic algorithm (GA) method has been applied to estimate the parameters of approximated nonlinear fractional-order chaotic system that modeled by a state-space representation. The feasibility of this approach is demonstrated through identifying the parameters of approximated fractional-order Lorenz chaotic system. The performance of the proposed algorithm is compared with the genetic algorithm (GA) and standard particle swarm optimization (SPSO) in terms of parameter accuracy and cost function. To evaluate the identification accuracy, the time-domain output error is designed as the fitness function for parameter optimization. Simulation results show that the proposed method is more successful than other algorithms for parameter identification of fractional order chaotic systems

    Prevalence rate of white spot syndrome virus (WSSV) in farmed white leg shrimp (Litopenaeus vannamei) in Bushehr province

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    We surveyed presence of white spot syndrome virus (WSSV) in farmed white leg shrimp in Bushehr province with assumed a prevalence of 2% of virus in target population. Hence, 468 samples were collected in two separate phases from May to October 2006. In the first phase, 200 samples (each sample was 150 pieces of post larvae with average age 7 days) were taken from 3 active hatcheries and in the second phase, 268 samples from 418 ponds in 5 sites were collected. Samples were tested by "Nested PCR" for detection of WSSV with 1Q2000 commercial kits. Results were negative and with respect to sampling method and sensitivity and specifity of Nested PCR we concluded that cultured shrimps were free of WSSV in 2006 in Bushehr province

    An integrated approach to study the impact of fractures distribution on the Ilam-Sarvak carbonate reservoirs: a case study from the Strait of Hormuz, the Persian Gulf

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    Most of the Iranian hydrocarbon reservoirs in the Persian Gulf Basin and the Zagros Fold-Thrust Belt are composed of fractured carbonate rocks. In this regard, determining the spatial distribution of fractures has been a challenging issue. In this study, an integrated approach was applied for understanding the impact of fractures spatial distribution on the Ilam-Sarvak (Cenomanian to Santonian) carbonate reservoir rocks. For this purpose, seismic interpretation techniques along with geomechanical and geostatistical modeling were employed to characterize fractures at different scales. Initially, the relationship between fractures origin and the normal faults was investigated by conducting an in-situ stress analysis. Afterwards, the velocity deviation log (VDL) and fracture intensity log (FIL) were derived as fracture attributes from the interpretation of Formation Micro Imager (FMI) and conventional well logs. A 3D model of VDL and FIL was achieved by using a sequential Gaussian simulation (SGS) method. In order to achieve a more realistic and accurate model of the factures distribution, variations of the shear-wave velocity and geomechanical properties (Young's modulus and Poisson's ratio) were estimated by applying the advanced seismic interpretation techniques in the normal faults domain. The results show that the intensity of fractures increases once they are introduced to the normal faults, especially in the central part of the study area around well#2. Such a fractured zone is verified by fracture density log derived from FMI logs of the mentioned well. Obviously, there is a close-knit relationship between the fracture system and the normal faults. Eventually, secondary porosity caused by features was determined though identification of Hydraulic Flow Units (HFUs). Based on the porosity and permeability data, seven HFUs were determined for the Ilam-Sarvak reservoirs. The very high values of Log FZI indicate the possible presence of fractures. Overall, the fractures contributed to enhance the secondary porosity of the reservoir rocks though increasing matrix permeability. To sum up, the fractures system plays a critical role in controlling reservoir properties especially in the hanging-wall of normal faults where the majority of the macro and micro fractures are distributed

    Enhancement of in vitro production of volatile organic compounds by shoot differentiation in Artemisia spicigera

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    Callus initiation, shoot formation and plant regeneration were established for Artemisia spicigera, a traditional medicinal plant growing in Armenia, Middle-Anatolia and Iran, and pro- ducing valuable volatile organic compounds (VOCs) that are mostly represented by monoterpe- noids. Optimal callus initiation and shoot production were obtained by culture of hypocotyl and cotyledon explants on MS medium comprising 0.5 mg L−1 naphthalene acetic acid (NAA) and 0.5 mg L−1 6-benzyladenine (BA). Consequently, the shoots were transferred onto the MS media sup- plemented with 1 mg L−1 of indole-3-butyric acid (IBA) or 1 mg L−1 of NAA. Both types of auxin induced root formation on the shoots and the resulting plantlets were successfully grown in pots. The production of VOCs in callus tissues and regenerated plantlets was studied by gas chroma- tography–mass spectrometry (GC-MS) analysis. Although the potential of undifferentiated callus to produce VOCs was very low, an increased content of bioactive volatile components was ob- served at the beginning of shoot primordia differentiation. Intriguingly, the volatiles obtained from in vitro plantlets showed quantitative and qualitative variation depending on the type of auxins used for the rooting process. The acquired quantities based on total ion current (TIC) showed that the regenerated plantlets using 1 mg L−1 NAA produced higher amounts of oxygenated monoter- penes such as camphor (30.29%), cis-thujone (7.07%), and 1,8-cineole (6.71%) and sesquiterpene derivatives, namely germacrene D (8.75%), bicyclogermacrene (4.0%) and spathulenol (1.49%) compared with the intact plant. According to these findings, in vitro generation of volatile organic compounds in A. spicigera depends on the developmental stages of tissues and may enhance with the formation of shoot primordia and regeneration of plantlets

    Resistin, an adipokine with non-generalized actions on sympathetic nerve activity

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    The World Health Organization has called obesity a global epidemic. There is a strong association between body weight gain and blood pressure. A major determinant of blood pressure is the level of activity in sympathetic nerves innervating cardiovascular organs. A characteristic of obesity, in both humans and in animal models, is an increase in sympathetic nerve activity to the skeletal muscle vasculature and to the kidneys. Obesity is now recognized as a chronic, low level inflammatory condition, and pro-inflammatory cytokines are elevated including those produced by adipose tissue. The most well-known adipokine released from fat tissue is leptin. The adipokine, resistin, is also released from adipose tissue. Resistin can act in the central nervous system to influence the sympathetic nerve activity. Here, we review the effects of resistin on sympathetic nerve activity and compare them with leptin. We build an argument that resistin and leptin may have complex interactions. Firstly, they may augment each other as both are excitatory on sympathetic nerves innervating cardiovascular organs; In contrast, they could antagonize each other's actions on brown adipose tissue, a key metabolic organ. These interactions may be important in conditions in which leptin and resistin are elevated, such as in obesity

    General practice pharmacists in Australia:A systematic review

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    BACKGROUND: The inclusion of pharmacists into general practices in Australia has expanded in recent years. This systematic review aimed to synthesise the literature of qualitative and quantitative studies, and identify the knowledge gaps, related to pharmacists working in general practice in Australia. METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, EBSCOhost, EMBASE, and the Cochrane Library were searched from the inception of databases to January 2021. The search was focused on studies investigating general practice pharmacists in Australia. The quality of each study was appraised using the Mixed Method Appraisal Tool criteria. The narrative synthesis approach was utilised to describe data due to the heterogeneity among study designs and measures. RESULTS: Twenty-five studies were included in this review. General practice pharmacists engaged in various non-dispensing patient care services, with medication management reviews being the primary activity reported. General practice pharmacists’ characteristics and an environment with a willingness of collaboration were the notable influencing factors for successfully including pharmacists in general practices. Factors that posed a challenge to the adoption of general practice pharmacists were lack of funding and other resources, poorly defined roles, and absence of mentoring/training. CONCLUSION: This review has summarised the characteristics, activities, benefits, barriers, and facilitators of including pharmacists in general practices in Australia. General practice pharmacists are well accepted by stakeholders, and they can engage in a range of patient-centred activities to benefit patients. There is a need for more robust research to explore the patient and economic outcomes related to clinical activities that a pharmacist can perform in general practice, as a foundation to developing an appropriate and sustainable funding model. The findings of this review will be beneficial for pharmacists, researchers, policymakers, and readers who wish to implement the role of general practice pharmacists in the future

    Quality Use of Medicines Indicators and Associated Factors in Residential Aged Care Facilities:Baseline Findings from the Pharmacists in RACF Study in Australia

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    Prescribing potentially inappropriate medications (PIMs), including antipsychotics and benzodiazepines, has been used as an indicator of the quality use of medicines in residential aged care facilities (RACFs). PIMs are associated with an increased risk of falls and hospitalisations in the elderly. The purpose of this study is to assess the extent of prescribing of PIMs in RACFs at baseline in the Pharmacists in residential aged care facilities (PiRACF) study and examine the association of resident and system factors with the number of PIMs. A cross-sectional analysis of 1368 participants from 15 Australian RACFs was performed to detect PIMs using the American Geriatrics Society 2019 Beers(®) criteria. Most residents (68.1%) were taking at least one regular PIM; 16.9% were taking regular antipsychotics and 11.1% were taking regular benzodiazepines. Long-term proton pump inhibitors were the most frequent class of PIMs. History of falls and higher Charlson Comorbidity Index were associated with an increased number of prescribed PIMs, while dementia diagnosis and older age (85 years or more) were associated with decreased number of PIMs (p-value <0.05). Residents in facilities with lower nurse-to-resident ratios were more likely to have an increased number of PIMs (p value = 0.001). This study indicates that potentially inappropriate prescribing is common in RACFs and interventions to target residents at highest risk are needed

    Evaluation of Pharmaceutical Compounding Training in the Australian Undergraduate Pharmacy Curricula

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    Introduction: In recent decades the role of the Australian community pharmacist hasevolved to focus primarily on pharmaceutical care provision. Despite this, compounding remainsan important product service offered by pharmacists. The aim of this study was to qualitativelydescribe the current integration of training in compounding within Bachelor of Pharmacy courses inAustralia. Methods: The Australian Health Practitioner Regulatory Agency website was searchedto identify eligible university courses. Subsequently, the educational providers’ homepages wereconsulted, and Bachelor of Pharmacy handbooks and curricula perused. All relevant informationregarding training in compounding was extracted. Results: In total, 16 Bachelor of Pharmacy courseswere identified. All of these contain compounding training in their curricula, including laboratoryclasses. Most curricula have units specifically dedicated to compounding and drug formulation.Three universities offer a curriculum which is organ-systems based, and include compoundingrelevant to the individual organ systems. Discussion and Conclusions: In Australia, the training incompounding is well integrated into pharmacy curriculum and is more emphasised than in manyother developed countries. This is congruent with the International Pharmaceutical Federation’sneeds-based approach to local pharmacy education. In Australia there is a need for pharmacists toroutinely dispense simple compounded products. Further research is required to evaluate Australianpharmacy graduates’ compounding abilities and how best to promote the achievement of the requiredknowledge and skills to enable simple compounding
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