American University of Beirut New York Office

This paper describes the development of a general probabilistic model of an autonomous solar-wind energy conversion system (SWECS) composed of several wind turbines (wind farm), several photovoltaic (PV) modules (solar park), and a battery storage feeding a load. The model takes into consideration outages due to the primary energy fluctuations and hardware failure. It allows the simulation of wind farms and solar parks containing either identical or different types of wind turbines and PV modules with the load being fed from either the renewable sources, or the battery storage, or both. A methodology is also presented to determine an upper limit on the size of the battery storage required to satisfy a given load profile taking into consideration the charging/discharging of the batteries.

The aim of this paper is to provide the core of a CAD/CAA tool that can help designers determine the optimal design of a hybrid wind-solar power system for either autonomous or grid-linked applications. The proposed analysis employs linear programming techniques to minimize the average production cost of electricity while meeting the load requirements in a reliable manner, and takes environmental factors into consideration both in the design and operation phases. While in autonomous systems, the environmental credit gained as compared to diesel alternatives can be obtained through direct optimization, in grid-linked systems emission is another variable to be minimized such that the use of renewable energy can be justified. A controller that monitors the operation of the autonomous/grid-linked systems is designed. Such a controller determines the energy available from each of the system components and the environmental credit of the system. It then gives details related to cost, unmet and spilled energies, and battery charge and discharge losses.

OBJECTIVES: This paper examines the effect of household crowding on inter-pregnancy spacing and its association with socioeconomic indicators, among parous mothers delivered in an urban environment. DESIGN: Cross sectional survey. METHODS: Sociodemographic data were obtained on 2466 parous women delivering at eight hospitals in Greater Beirut over a one year period. Statistical methodology comprised Pearson chi(2) test and logistic regression analysis. MAIN RESULTS: A significant inverse relation was observed between household crowding and socioeconomic status, defined as education and occupation of women and their spouses. Inter-pregnancy spacing increased with higher levels of crowding. Further analysis suggested that this positive association was confounded by maternal demographic characteristics. CONCLUSIONS: These data have shown that household crowding, a correlate of low parental socioeconomic status, is associated with longer birth intervals. This association, however, seems to be largely explained by maternal age and parity.

The purpose of this study was to explore how some university biology majors in Beirut, Lebanon, accommodate the theory of biological evolution with their existing religious beliefs. Sixty-two students enrolled in a required senior biology seminar responded to open-ended questions that addressed (a) their understanding of the theory of evolution, (b) their perception of conflict between this theory and religion, and (c) whether the theory of evolution clashed with their own beliefs about the world. Based on their responses, 15 students were selected for an in-depth exploration of their written responses. Students' answers clustered under 1 of 4 main positions: for evolution, against evolution, compromise, and neutral. The authors suggest that teaching students about the nature of scientific facts, theories, and evidence is more likely to enhance understanding of evolutionary theory if students are given the opportunity to discuss their values and beliefs in relation to scientific knowledge. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 429–445, 1997.

Transcription factors are regulatory proteins that either activate or repress the transcription of genes via binding to DNA regulatory sequences and regulating recruitment of transcriptional complexes. Lymphoid enhancer-binding factor 1 (LEF1), a member of the T-cell Factor (TCF)/LEF1 family of high-mobility group transcription factors, is a downstream mediator of the Wnt/β-catenin signaling pathway, but can also modulate gene transcription independently. LEF1 is essential in stem cell maintenance and organ development, especially in its role in epithelial-mesenchymal transition (EMT) by activating the transcription of hallmark EMT effectors including N-Cadherin, Vimentin, and Snail. Aberrant expression of LEF1 is implicated in tumorigenesis and cancer cell proliferation, migration, and invasion. LEF1's activity in particular cancer cell types, such as chronic lymphocytic leukemia (CLL), Burkitt lymphoma (BL), acute lymphoblastic leukemia (ALL), oral squamous cell carcinoma (OSCC), and colorectal cancer (CRC), makes it a valuable biomarker in predicting patient prognosis. Additionally, due to aberrant LEF1 activity resulting in cancer progression, knockdown and inhibition treatments designed to target LEF1 have proven effective in alleviating cancer growth, migration, and invasion in CLL, CRC, glioblastoma multiforme (GBM), and renal cell carcinoma (RCC). In prostate cancer cells, LEF1 promotes androgen receptor expression and activity in an androgen-independent manner, ultimately increasing prostate cancer growth regardless of androgen ablation therapy. In this review, we review LEF1 regulation, its role in tumorigenesis in several cancer types, and its clinical value as a biomarker for predicting prognoses and as a target for treatment.

This paper discusses the control problem for a class of wind energy conversion systems (WECS). It first develops a detailed model and then compares four control algorithms based on conventional and intelligent control theories. A simple PI conventional controller for the exciter loop is carried out by using a first order model. When the system operating points change, the PI controller fails to provide sufficient damping or acceptable performance. Therefore both fuzzy voltage and fuzzy power regulators are introduced. Also a conventional adaptive pitch controller is proposed to adjust the pitch angle of the rotor blades in order to maximize the energy capture and reduce the mechanical loads. As an alternative to this controller, a neural network controller is also designed. Using the existing nonlinear wind model and the different control algorithms, the dynamic behavior of the controlled (WECS) is simulated. By selecting convenient wind data, the system characteristics such as its tracking performance, its robustness and its ability to recover from large disturbances are studied and discussed.

Content moderation has exploded as a policy, advocacy, and public concern. But these debates still tend to be driven by high-profile incidents and to focus on the largest, US based platforms. In order to contribute to informed policymaking, scholarship in this area needs to recognise that moderation is an expansive socio-technical phenomenon, which functions in many contexts and takes many forms. Expanding the discussion also changes how we assess the array of proposed policy solutions meant to improve content moderation. Here, nine content moderation scholars working in critical internet studies propose how to expand research on content moderation, with implications for policy.

This work is concerned with the development of an adaptive fuzzy logic controller for a wind-diesel system composed of a stall regulated wind turbine with an induction generator connected to an AC busbar in parallel with a diesel generator set having a synchronous generator. In this work we propose to use an adaptive network based inference system (ANFIS) in order to generate fuzzy membership functions and control rules for the controller. A feedback linearized proportional integral controller is used to provide the required expert knowledge. A controller design process is identified; it consists of generating input-output data pairs to identify the control variables range and initial fuzzy memberships, and then to tune or adapt them using an ANFIS network structure. The controller inputs are the frequency error and its integral for the governor part of the controller, and the voltage and frequency errors for the automatic voltage regulator. These are readily measurable quantities leading to a simple controller which can be easily implemented.

We developed a PCR-based assay for the rapid and specific laboratory diagnosis of human brucellosis directly from whole blood. Specimens were collected in EDTA tubes from 17 patients with acute serologic brucellosis and 3 patients with chronic relapsing brucellosis as determined by serologic tests and the patient's clinical picture. DNA was extracted from peripheral mononuclear cells obtained from the blood of patients with brucellosis and control individuals. Specific primers for the PCR amplification of a 223-bp region on the sequence encoding the 31-kDa immunogenic Brucella abortus protein (BCSP 31) were used. All amplicons had the expected size of 223 bp. The specificity of amplification was determined by Southern hybridization and restriction endonuclease analysis. DNA extracted from blood taken from 30 healthy individuals as well as from 9 patients with typhoid fever did not show any amplification with the primers used. The test proved to be rapid and specific for the laboratory confirmation of acute human brucellosis. Further studies must be conducted to assess the utility of this test on additional patients with chronic relapsing brucellosis as well as patients under treatment.

News creation and consumption has been changing since the advent of social media. An estimated 2.95 billion people in 2019 used social media worldwide. The widespread of the Coronavirus COVID-19 resulted with a tsunami of social media. Most platforms were used to transmit relevant news, guidelines and precautions to people. According to WHO, uncontrolled conspiracy theories and propaganda are spreading faster than the COVID-19 pandemic itself, creating an infodemic and thus causing psychological panic, misleading medical advises, and economic disruption. Accordingly, discussions have been initiated with the objective of moderating all COVID-19's communications, except those initiated from trusted sources such as the WHO and authorized governmental entities. This article presents a large-scale study based on data mined from Twitter. Extensive analysis has been performed on approximately one million COVID-19 related tweets collected over a period of two months. Furthermore, the profiles of 288,000 users were analyzed including unique users' profiles, meta-data and tweets' context. The study noted various interesting conclusions including the critical impact in term of reach level of the (1) exploitation of the COVID-19 crisis to redirect readers to irrelevant topics and (2) widespread of unauthentic medical precautions and information. Further data analysis revealed the importance of using social networks in a global pandemic crisis by relying on credible users with variety of occupations, content developers and influencers in specific fields. In this context, several insights and findings have been provided while elaborating computing and non-computing implications and research directions for potential solutions and social networks management strategies during crisis periods.

Summary Five date palm ( Phoenix dactylifera L.) varieties, commonly grown in the UAE, were studied for their chemical composition, physical, mechanical and rheological properties. All measurements were made at the ‘tamr’ stage, the final stage of fruit ripeness. Samples were analysed for sugar, moisture, protein, ash and mineral element contents. Physical measurements as well as mechanical and rheological measurements of the fruit including pitting pressure, shear pressure, and modulus of elasticity were also carried out. Significant differences were observed in the characteristics that were studied, allowing for distinguishable grades among the five varieties. Chemical and physical characteristics of the fruits influenced their mechanical and rheological properties, which in turn can be indicators of firmness and ultimately of quality. Results from this work revealed new and essential information for better understanding of the date fruit that helps to enhance industrialisation and propagation of the best date varieties that satisfy producers’ as well as consumers’ demands.

OBJECTIVE: To review the clinical presentation of patients with rhinoliths, which are calcareous concretions with an unclear pathogenesis. STUDY DESIGN AND SETTING: Using retrospective chart review we analyzed clinical, radiological, and demographic data as well as our diagnostic work-up and management of 8 patients. RESULTS: Most patients presented with nonspecific nasal complaints; most commonly, purulent rhinorrhea and nasal obstruction. The rhinolith was discovered incidentally in some patients. CONCLUSION: Rhinoliths are rare and can have various clinical presentations. The treatment of choice is surgical removal. SIGNIFICANCE: A high index of suspicion is required for the diagnosis of such a forgotten entity.

Hydroxychloroquine (HCQ), a commonly used antimalarial drug in rheumatic diseases, has shown favorable metabolic effects on both glucose control and lipid profiles. We describe a case of a young woman with type 1 diabetes whose glycemic control was optimized with the introduction of HCQ as a treatment for her Sjogren syndrome in addition to a subtle yet measurable improvement in her lipid profile. An increasing body of evidence supports the beneficial impacts of HCQ in various ancillary conditions, including diabetes mellitus and dyslipidemia. However, mechanisms of action responsible for these effects remain ill-defined and may include alterations in insulin metabolism and signaling through cellular receptors. These favorable metabolic effects of HCQ and further understanding of underlying mechanisms may provide an additional rational for its use in rheumatic diseases, conditions associated with an elevated cardiovascular risk.

Recently, there has been a growing interest in harnessing renewable energy resources particularly for electricity generation. One of the main concerns in the design of an electric power system that utilizes renewable energy sources, is the accurate selection of system components that can economically satisfy the load demand. This depends on the load that ought to be met, the capacity of renewable resources, the available space for wind machines and solar panels, and the capital and running costs of system components. Once size optimization is achieved, the autonomous system must be controlled in order to correcly match load requirements with instantaneous variation of input energy. In this paper, a new formulation for optimizing the design of an autonomous wind-solar-diesel-battery energy system is developed. This formultation employs linear programming techniques to minimize the average production cost of electricity while meeting the load requirements in a reliable manner. The computer program developed reads the necessary input data, formulates the optimization problem by computing the coefficients of the objective function and the constraints and provides the optimum wind, solar, diesel, and battery ratings. In order to study the effect of parameters predefined by the designer on the optimum design, several sensitivity analysis studies are performed, and the effects of the expected energy not served, the load level, the maximum available wind area, the maximum available solar area, and the diesel engines' lifetime are investigated. A controller the monitors the operation of the autonomous system is designed. The operation of this controller is based on three major policies; in the first, batteries operate before diesel engines and hence the storage system acts as a fuel saver, while in the second diesel engines are operated first so that the unmet energy is lower but the fuel cost is high. According to the third policy, the supply is made through diesel engines only. This is done for the purpose of making a performance comparison between the isolated diesel system and the hybrid renewable energy system. The proposed optimization and control techniques are tested on Lebanese data. Although three different control policies have been adopted in this work, the software is able to accommodate other policies.

Visual dataflow languages (VDFLs), which include commercial and research systems, have had a substantial impact on end-user programming. Like any other programming languages, whether visual or textual, VDFLs often contain faults. A desire to provide programmers of these languages with some of the benefits of traditional testing methodologies has been the driving force behind our effort in this work. In this article we introduce, in the context of prograph, a testing methodology for VDFLs based on structural test adequacy criteria and coverage. This article also reports on the results of two empirical studies. The first study was conducted to obtain meaningful information about, in particular, the effectiveness of our all-Dus criteria in detecting a reasonable percentage of faults in VDFLs. The second study was conducted to evaluate, under the same criterion, the effectiveness of our methodology in assisting users to visually localize faults by reducing their search space. Both studies were conducted using a testing system that we have implemented in Prograph's IDE.

This paper describes the development of a general probabilistic model of an autonomous wind energy conversion system (WECS) composed of several wind turbines (wind farm) connected to a load and a battery storage. The proposed technique allows the simulation of wind farms containing identical or different wind turbines types and considers a bidirectional flow of power in and out of the battery. The model is based upon a simple procedure to estimate the joint probability distribution function of the total available wind power and that of the turbines operating modes due to hardware failure. A methodology is also developed to use the proposed model to determine an upper limit on the size of the battery storage required for a given number of turbines to satisfy the load with a certain expected energy not supplied (EENS). The model can also be used to evaluate the energy purchased from or injected to the grid in the case of grid-connected systems.

India has one of the highest burdens of diabetes worldwide, and rates of diabetes are also high among Asian Indian immigrants that have migrated into the United States (U.S.). Sikhs represent a significant portion of Asian Indians in the U.S. Diabetes prevention programs have shown the benefits of using lifestyle intervention to reduce diabetes risk, yet there have been no culturally-tailored programs for diabetes prevention in the Sikh community. Using a quasi-experimental two-arm design, 126 Sikh Asian Indians living in New York City were enrolled in a six-workshop intervention led by community health workers. A total of 108 participants completed baseline and 6-month follow-up surveys between March 2012 and October 2013. Main outcome measures included clinical variables (weight, body mass index (BMI), waist circumference, blood pressure, glucose, and cholesterol) and health behaviors (changes in physical activity, food behaviors, and diabetes knowledge). Changes were significant for the treatment group in weight, BMI, waist circumference, blood pressure, glucose, physical activity, food behaviors, and diabetes knowledge, and between group differences were significant for glucose, diabetes knowledge, portion control, and physical activity social interaction. Retention rates were high. Findings demonstrate that a diabetes prevention program in the Sikh community is acceptable, feasible, and efficacious.

Neonatal lesions of the ventral hippocampus in rats produce changes in spontaneous and pharmacologically induced dopamine-dependent behaviors that emerge in early adulthood. Neural mechanisms underlying these changes may have implications for understanding the neurobiology of schizophrenia, putatively a neurodevelopmental disorder. In this study, we evaluated the effects of MK-801 (dizocilpine), on automated measures of distance traveled and stereotypies in adult rats with neonatal (postnatal day 7) lesions, and tested the effects of haloperidol, clozapine and an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA) antagonist LY293558 on the MK-801-induced behaviors. The lesioned rats showed significantly greater increases in motor activity after 0.05 and O.1 mg/kg of MK-801 than did controls. Both haloperidol (0.1 and 0.4 mg/kg) and clozapine (4 and 10 mg/kg) reduced hyperlocomotion elicited by 0.2 mg/kg MK-801 in the ventral hippocampus (VH)-lesioned and sham rats. Haloperidol was more potent than clozapine in decreasing MK-801-induced stereotypy, especially in the lesioned rats. Moreover, an AMPA antagonist normalized exaggerated MK-801-induced hyperolocomotion in the lesioned rats at doses that had no effect in controls. These results demonstrate that the lesioned rats are more sensitive to MK-801 during adulthood than control rats, and that antidopaminergic drugs as well as AMPA antagonists antagonize the MK-801-induced behaviors. The neonatal lesion rat model may be useful to further our understanding of the interactions between dopamine and glutamate and their role in the pathophysiology of schizophrenia.

Cosmetic, functional, and structural sequelae of scarring are innumerable, and measures exist to optimize and ultimately minimize these sequelae. To evaluate the innumerable methods available to decrease the cosmetic, functional, and structural repercussions of scarring, pubMed search of the English literature with key words scar, scar revision, scar prevention, scar treatment, scar remodeling, cicatrix, cicatrix treatment, and cicatrix remodeling was done. Original articles and reviews were examined and included. Seventy-nine manuscripts were reviewed. Techniques, comparisons, and results were reviewed and tabulated. Overall, though topical modalities are easier to use and are usually more attractive to the patient, the surgical approaches still prove to be superior and more reliable. However, advances in topical medications for scar modification are on the rise and a change towards medical treatment of scars may emerge as the next best approach. Comparison studies of the innumerable specific modalities for scar revision and prevention are impossible. Standardization of techniques is lacking. Scarring, the body's natural response to a wound, can create many adverse effects. At this point, the practice of sound, surgical fundamentals still trump the most advanced preventative methods and revision techniques. Advances in medical approaches are available, however, to assist the scarring process, which even the most advanced surgical fundamentals will ultimately lead to. Whether through newer topical therapies, light treatment, or classical surgical intervention, our treatment armamentarium of scars has expanded and will allow us to maximize scar prevention and to minimize scar morbidity.

Gestational diabetes mellitus (GDM) is a complication of pregnancy that is characterized by impaired glucose tolerance with onset or first recognition during pregnancy. The reported prevalence of GDM varies between 0.6% and 20% of pregnancies depending on screening method, gestational age and the population studied. GDM is characterized by pancreatic β-cell function that is insufficient to meet the body’s insulin needs. Available evidence suggests that β-cell defects in GDM result from the same spectrum of causes that underline hyperglycemia in general, including autoimmune disease, monogenic causes and insulin resistance. Adipokines are proteins secreted from the adipocytes and are believed to have a metabolic influence. Our review suggests that, in GDM, various adipokines, mainly leptin and adiponectin, are dysregulated. These two adipokines might have both prognostic and pathophysiological significance in this disease.