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Studying the Effects of Mild and Severe Lysine Deficiency on Hippocampal-Related Functions
No full textNeurogenesis is the developmental process of generating new functionally integrated neurons. This phenomenon occurs in selected neurogenic niches including the hippocampal dentate gyrus (DG) and the ventricular-subventricular zone. Neurogenesis is affected by various factors including aging, oxidative stress, brain injury, environmental factors, stress, and nutritional aspects such as protein deficiency. Lysine is one of the 9 essential amino acids that are not synthesized by the body and need to be supplied exogenously through a diet. Numerous reports have correlated lysine deficiency with cognitive decline; however, the effect of lysine deficiency on hippocampal neurogenesis has not yet been addressed in the literature. This study hypothesizes the impairment of hippocampal neurogenesis and thus hippocampal-related functions due to mild and severe induced lysine deficiency. Studying this impairment through behavioural and molecular tests could showcase a novel relationship between diet and cognition
In the steps of the sultan : essays in honor of Abdulrahim Abu-Husayn
Get PDFFor forty years, Abdulrahim Abu-Husayn’s work at the American University of Beirut revised how we understand the relations of power between the Ottoman center and its Arab peripheries. His ambitious research brought material from the imperial archives into conversation with local chronicles to shed light on the past while simultaneously challenging its misplaced mythologies. However, despite his imposing professional credentials, Abu-Husayn was just as renowned for his sparkling charm and magnanimous personality, which made “the Sultan” beloved by those who knew him. In the Steps of the Sultan seeks to pay tribute to both Abu-Husayn the historian and Abed the man. Chapters by colleagues, friends, and former protégées offer new perspectives on themes that intersect with Abu-Husayn’s own varied interests, ranging from Lebanese historiography to views from Istanbul, from Syrian provincial politics to the Syriac heritage of Qatar, and from conceptualizations of the caliphate to depictions of divine beauty
A Comparative Techno-Economic Analysis and Life-Cycle Assessment of Ammonia Production Processes Toward a Sustainable Energy Transition
No full textMany countries and especially Arab oil producing ones are working toward diversifying their energy mix and transitioning away from fossil fuels as part of their national and international sustainability and clean energy efforts. Lebanon has been facing increasing widespread electricity blackouts after decades of unsustainable electricity production policies and fundamental neglect on the energy sector, which led to drastic negative environmental impacts that demand instant action. Looking at the silver lining, ammonia has been used since the World War as a great fertilizer that aided humanity and pushed for its growth. Adhering to global efforts toward decarbonization and a diversified energy mix, ammonia can be utilized directly as a fuel and as an energy (hydrogen) carrier. Although ammonia does not have carbon dioxide in its structure, typical production routes contribute to 1-1.7% of global CO₂ emissions. Several works in the literature and industries, internationally and regionally, have set the goal to produce more environmentally friendly ammonia using renewable sources of energy and carbon capture technologies to reduce its environmental bill and enhance its role toward a sustainable energy transition. As a grounding step to contribute to making this a reality, this research study offers a comprehensive approach to assess the efficiency, competitiveness, and environmental friendliness of six ammonia synthesis configurations using a scenario analysis of Grey, Blue, Hybrid Blue, Enhanced Blue, Hybrid Enhanced Blue, and Green ammonia processes. This is done through a techno-economic analysis and life-cycle assessment using openLCA software performed for the six chosen ammonia production routes. Sensitivity analyses are developed to evaluate the effect of fluctuating prices of natural gas, ammonia, urea, and carbon dioxide credits on the economic feasibility of each configuration and to test the impact of varying natural gas leakage percentage on the environmental impact of each route. Finally, an analytical hierarchy process for a multi-criteria decision-making analysis was conducted with varied priorities of environmental and economic criteria. The results of this study allow the determination of the most efficient, competitive, and environmentally friendly ammonia synthesis process to be used for producing ammonia as a long-term clean energy source and a domestic industrial fertilizers production in Lebanon and the region.
Assessing the in vitro Effect of Ro 90-7501 on the Radiosensitivity of Breast Cancer Cell Lines
No full textBackground: Breast cancer is the most commonly diagnosed cancer in women and one of the main causes of death within the female population. Radiotherapy is one of the main treatments, but its efficiency is limited by the radiosensitivity of both, the patient and the tumor. After irradiation, different types of DNA damage are induced, with the DNA double-strand breaks (DSB) being the most lethal. Studies have shown that the capacity of the cell to repair the radio-induced DSB is correlated with clinical and cellular radiosensitivity. Recently, a study has shown that Ro 90-7501, a drug that inhibits the development of amyloid β42 fibrils linked to Alzheimer’s disease, has significant radiosensitizing effects on cervical cancer cell lines by inhibiting the efficiency of the DNA DSB repair.
Aim: The purpose of this study is to assess the radio-sensitizing potential of Ro 90-7501 on breast cancer and normal skin fibroblast cell lines.
Materials and Methods: Two breast cancer cell lines, MDA and MCF7, and one normal skin fibroblast cell line, GM03652, were used in this study. The MTT and Trypan Blue assays have been employed to measure cell viability, proliferation, and cytotoxicity. The anti- pATM and anti-γH2AX Immunofluorescence assay was performed to measure the ability of cells to repair the DNA DSBs.
Results: Ro 90-7501 significantly decreased breast cancer cells’ viability and proliferation; however, it showed no effect on normal tissues. When combined with radiation, Ro 90-7501 enhanced the radio-sensitivity of breast cancer cells by inhibiting DSB repair, with limited effect on normal tissues.
Conclusion: This study revealed that the drug Ro 90-7501 is a promising radiosensitizer for breast cancer cell lines
Cytochrome-P450 Implications in the Mechanisms of Central and Peripheral Nerve Injury
No full textDiabetes mellitus (DM) is a chronic metabolic disorder that targets a multitude of organs. Among the common complications of diabetes is Diabetic Neuropathy (DN), characterized by a range of clinical syndromes resulting from damage to the nervous system. Abnormalities in glucose metabolism can result in neural dysfunction and a variety of acute and chronic nervous system disorders, In the periphery, Diabetic Peripheral Neuropathy (DPN) is the most common and intractable microvascular complication of diabetes, affecting somatic sensory and motor nerves. In the central nervous system, type 2 diabetes (T2D) is a robust predictor of cognitive impairment and decline mimicking Alzheimer’s Disease (AD). This is currently recognized as type 3 diabetes (T3D). Research has shown insulin signaling deficits, increased oxidative stress and accumulation of neurotoxic proteins to be a common pathogenic mechanism to both AD and diabetes. To date, no therapies are available beyond symptomatic relief for both pathologies. Thus, the importance of this work is to find biomarkers for the early detection and novel mechanistic targets that may be of promise for intervention. To be able to do that, we aimed to investigate common mechanisms of injury to both pathologies. Aims: Our study focuses on the role of Cytochrome P450 (CYP450) as a major source of ROS production while exploring the concomitant occurrence of peripheral nerve injuries and central cognitive decline like Alzheimer’s Disease dementia, and the implication of the CYP450 metabolites of arachidonic acid metabolism, 20-HETE and EET imbalance in both pathologies. To that end, we hypothesize that hyperglycemia because of chronic diabetes progression triggers alterations in the CYP450 pathway and a pathophysiological imbalance in 20-HETE and EETs levels. Altogether, a state of oxidative stress ensues culminating in behavioral and molecular changes in the diabetic brain and sciatic nerve tissue. We further hypothesize that the pharmacological intervention with 20-HETE synthase or sEH enzyme inhibitors may alleviate cognitive deficits and peripheral nerve damage. Methods: The following study investigates CYP mechanisms using pharmacological agents, HET0016 and AUDA in vivo in an experimental model of T2D, the MKR murine model. Animals were subjected to peripheral and central nerve assessments using the Beam Walking Test, Grip Strength test, Thermal Algesia Test, Novel Object Recognition, and Y-maze. In parallel, markers of nerve injury as well as oxidative stress were assessed using a variety of techniques such as western blot, HPLC and NADPH oxidase assay. We pay particular attention to the markers of myelination MPZ and PMP22, EET-degrading enzyme, the soluble epoxide hydrolase, and the 20-HETE synthase CYP4A as well as EET-synthase CYP2C. We also investigated the beta amyloid expression in the hippocampus to screen for brain injury. Results: Behavioral data showed hyperglycemia induced damage in the central and peripheral nervous system in our mice model. Treatments with AUDA or HET0016 revealed a restoration in the peripheral and cognitive behavior. On the molecular level, sciatic nerves of the diabetic mice exhibited changes in the myelin protein profiles and CytochromeP450 enzymes. In the brain, hippocampal lysates demonstrated accumulations of beta amyloid proteins in the diabetic group. NADPH dependent ROS production presented increased ROS in the sciatic nerve and brain of diabetic group revealing a significant rise oxidative stress. We also observed fluctuations in the levels of EETs and 20-HETE in sciatic nerves of our animal models. HET0016 or AUDA administration were shown to restore diabetes-induced 20-HETE/EET imbalance as well as ROS overproduction. Conclusion: In conclusion, we provide evidence for the concomitant occurrence of both DPN and cognitive decline in diabetic animals with emphasis on the role of CYP450 20-HETE/EET imbalance as a mechanism of injury common to diabetes-induced nerve injury in both the CNS and PNS
Preserve the Perverse: Naughty Words in the Nahdah
Get PDFIn this thesis, I closely analyze Ahmad Faris al-Shidyaq’s use of enumeration in al-Saq ‘ala al-Saq (1855). Al-Shidyaq uses enumerations and lists throughout al-Saq to thwart power structures spanning religious, political, colonial, literary, and sectarian domains in mid-nineteenth-century Syro-Lebanon. The Arabic language’s capacity to render new subjectivities, power dynamics, and capitalist relations legible made it a charged site of debate and reform in the nineteenth century because of its centrality to questions of Arab identity. While al-Shidyaq’s al-Saq powerfully demonstrates this in several ways, my focus is on the critical role of lists and enumerations, which are especially valuable and revelatory for several reasons, including (1) their interruptive and “excessive” operations and profane content that aims to neutralize and resist authoritative order, particularly religious authorities seeking to sanction taboos as themselves “excessive”; (3) their sonic engagement with the carnal characteristic of al-Saq; (4) their testament to the emergence of print technologies which effected a new macrotypography and forms of textual presentation in Arabic books. I examine al-Shidyaq’s use of lists and enumerations within the broader Nahdawi context to unpack their polemical functions and underlying mechanisms as critiques of dominant power structures. To provide a theoretical framework for this analysis, I employ monster theory and Bakhtinian theory (the carnivalesque, grotesque, heteroglossia, and polyphony) to argue that al-Saq is a disruptive and subversive text that challenges the orthodoxies of language and society alike
The Effect of a Genre-Based Approach and Translanguaging on Lebanese Upper Elementary Students’ Skills in Writing Explanations
Get PDFLebanon is a multilingual context in which science is taught in a foreign language. Little
attention has been given to how Lebanese students develop subject-specific language
skills. The purpose of this study was to examine whether genre-based instruction and
translanguaging – the use of the full repertoire of students’ linguistic resources - can
improve Lebanese sixth-grade students’ skills in using the features of the explanation
genre in the context of writing. The participants of the study included a total of 70 sixth-
grade students, whose native language is Arabic and who fit the profile of being English
language learners (ELLs) studying science in English in a Lebanese private school. The
study adopted a quasi-experimental design in which a pre-test and post-test were
administered to three grade six sections: a control group, and two intervention
classrooms. The control group covered three instructional units on “Dangers of Tobacco,
Alcoholism, and Drugs” and “Functions of the Nervous System”, and “Functions of the
Urinary System”. The first experimental intervention group received genre-based writing
instruction in the context of instruction of the same topics addressed in the control group.
The second experimental intervention group also received genre-based instruction, but
with the addition of strategic translanguaging. Pre and post-test scores of the students’
writing were compared across all groups through an analysis of covariance ANCOVA as
well as post-hoc pairwise comparisons in order to evaluate the study’s hypotheses. The
study's findings demonstrated that genre-based instruction was able to improve students’
writing skills, the observed difference approached but did not reach statistical
significance in the overall posttest scores, but it did yield significance in one of its
prompts. Results also indicated that the integration of translanguaging into genre-based
instruction further enhances these writing skills yielding statistical significance in the
overall posttest scores and two of the posttest’s writing prompts. The study's findings
illuminate the potential for future research in understanding the synergistic interplay
between genre-based instruction and translanguaging, emphasizing their complementary
nature in enhancing writing skills in science. Moreover, the study underscores the
importance of integrating genre-based instruction and translanguaging into language
instruction, advocating for comprehensive teacher training to effectively implement these
strategies
Measurement of Thermal Conductivity of Silicon-Carbon Nanograins by Optothermal Raman Spectroscopy
No full textOptothermal Raman spectroscopy is a steady-state technique for measuring the
thermal conductivity of materials. In this method, Raman spectroscopy is used to
measure the local temperature rise of the sample, using the excitation laser as a
heat source. Optothermal Raman is used to measure the thermal conductivity of
silicon-carbon nanograins mixtures as a function of carbon and silicon content, to
determine the effect of boundaries on nanoscale heat transport experimentally. It
is found that the thermal conductivity of silicon-carbon nanograins mixtures varies
rapidly between 4.3 W/m.K and 15.3 W/m.K as a function of silicon and carbon
content. We thus demonstrate that optothermal Raman spectroscopy is an effective
non-destructive method for measuring the thermal conductivity of random materials
and that the thermal conductivity of silicon-carbon nanograins mixtures is highly
sensitive to the ratio of silicon-to-carbon content. In other words, we found that
grain boundary density significantly affects nanoscale heat transport. We hope that
our work will pave the way for an experimental study of nanoscale thermal resistance,
which has remained obscure to scientist
Controlled In-Situ Growth of ZIF on PVDF-HFP ZnCl2 Electrospun Membrane for Advanced Antibacterial Activity
No full textThis study explores the historical impact of pandemics, ongoing repercussions of COVID-19, and the urgent need for new strategies to combat highly contagious and deadly diseases. In particular, zeolite imidazolate framework (ZIF) has the potential to improve personal protective equipment (PPE) by effectively dispersing silver nanoparticles and releasing silver ions that have strong bactericidal effects.
PVDF-HFP ZnCl2 membrane will be produced through electrospinning technique. The primary objective is to enhance the membrane’s anti-bacterial properties through the strategic growth of post metalated Zeolitic imidazolate frameworks ZIF/Ag on its surface at different concentrations. The study employs an array of analytical techniques including SEM, PXRD, porosity analysis and water contact angle in order to determine results. SEM findings demonstrate that both 1 and 3 wt. % membranes exhibit a loss of ZIF from the fiber surface at a silver concentration of 1.5g. This is likely due the increased acidity from the elevated silver levels that disrupts the ZIF framework structure. On the other hand, ZIF 8 and L growth increases when silver concentration drops from 0.1g to 0.05g, indicating an improved function for zinc ions in the absence of competitive silver interactions. In addition, membranes achieved up to 98% bacterial inhibition in samples with high silver concentrations in which no ZIF could grow while this inhibition % was reached at a significantly lower Ag loading % than those with higher silver content, where ZIF was successfully formed on the fibers' surfaces. This definitely supports the significance of MOFs in this study as an antibacterial agent. PXRD, WCA and porosity results were in good agreement with the SEM results
Economic Feasibility for Distinct Solar Panels’ Allocation and Trajectory
No full textGlobal energy consumption is on the rise, reflecting worries about the environmental impact of conventional fuel sources. In the quest for sustainable solutions, solar energy is at the top of the list. This study explores several approaches for deploying solar photovoltaic panels while taking sunlight path and position into account. It carefully takes into consideration regional variables, climatic trends, available space, financial concerns, and energy consumption profiles when analyzing the best deployment strategies for residential, commercial, and large-scale applications. The study focuses on East-West panel layouts, comparing their environmental and economic impacts to fixed, or south, installations. It investigates how different tilt and azimuth angles affect energy collection, affordability, upkeep requirements, and sustainability in general. With the use of accurate irradiance measurements and data from solar atlases, the research thoroughly examines the effectiveness of every design. These discoveries have major implications for people interested in solar energy solutions. The objective of this research is to enhance decision- making abilities for optimizing solar energy use in various scenarios by examining the interplay of panel types, allocation algorithms, and solar route modifications