11351 research outputs found
Sort by
(R2164) The Nature of the Big Bang Singularity in Inhomogeneous Szekeres Cosmological Frameworks
No full textWithout killing vector fields, the Szekeres metric is an explicit example of an anisotropic and inhomogeneous solution to the Einstein equations. The inhomogeneous Szekeres cosmological models (ISCM) within the Big Bang singularity (BBS) are obtained. This indicates that the Szekeres solution represents a more general class of exact solutions. It is known to exhibit axial symmetry. We investigate a Big Bang theory of the cosmos, which unexpectedly predicts that the universe started at the so-called BBS a finite length of time ago. A growing number of astrophysical researchers are using inhomogeneous extensions of the Friedmann-Lemaitre-Robertson-Walker (FLRW) solution and, by extension, Lemaitre-Tolman-Bondi (LTB) solution to investigate cosmic events. In this particular scenario, the Scwarzschild-Kruskal-Szekeres metrics, dust Robertson Walker, and LTB models with zero pressure are all contained in the Szekeres metric. In this paper, we first provide the Szekeres model solutions, and then we expand on recent discussions on the BBS in anisotropic and inhomogeneous Szekeres cosmological models. The BBS for the Szekeres inhomogeneous model and some new solutions are presented
(R2150) Impact of Specialist Predator Harvesting on the Stability of a Three-Species Food Chain Model with a Generalist Predator
No full textIn this study, the stability of a three-species food chain model comprising a prey, an intermediate specialist predator, and a top predator exhibiting generalist behavior is examined, with harvesting applied to the intermediate predator. The main objective is to investigate how variations in the harvesting rate influence system stability and the coexistence of all three species. The positivity, boundedness, and equilibrium points of the model are analyzed to ensure biological feasibility. The equilibrium point involving the prey and the top predator satisfies the criteria for both local and global asymptotic stability. The coexistence equilibrium point attains local asymptotic stability based on the Routh-Hurwitz criteria, and a Lyapunov function is constructed to demonstrate global asymptotic stability. The theoretical findings are validated through numerical simulations, which also explore the effects of varying harvesting intensities on species persistence
Stock Price Reaction To Green Bond Issuance In The United States
No full textIn this quantitative study, I investigated the impact of corporate green bond issuance on the U.S. stock market between May 2007 and December 2023. Green bonds are a new financial tool. I collected 189 corporate green bond issues from Bloomberg. I used the event study method to analyze the data. Instead of corroborating previous research, the findings showed that a negative stock market reaction occurred when companies issue green bonds. This result supports the argument of greenwashing. I also examined corporate environmental, social, and governance (ESG) disclosure scores and found that corporations with high environmental scores had fewer negative stock reactions, indicating that companies engaged more in environmental protection are less prone to greenwashing. I introduced a dummy variable to distinguish the time before and after the COVID-19 pandemic and found that the negative stock reaction was more prominent following the onset of the pandemic.
Keywords: green bond, ESG, environmental, social, and governance, issuance announcement, stock retur
African American Males In Rural Elementary Schools During The Pandemic: Experiences, Challenges, And Strategies For Success
Full text linkThe present study experimentally examined the impact of the COVID-19 pandemic on elementary African American males living in rural areas. The qualitative study used a phenomenological approach to examine students\u27 perspectives, as understood by the parents and educators (N=10). Using semi-structured interviews and thematic coding, the researcher suggested strategies for successfully closing instructional gaps and meeting the needs of this population moving forward.
The theoretical frameworks that triggered this exploration were Intersectionality, Maslow’s Hierarchy of Needs, and Conflict Theory. The researcher used the theories as a lens to answer the following research questions: (1) How much has COVID-19 revealed the academic and structural disparities in rural elementary education? (2) What social-emotional effects have COVID-19, and school closures had on African American boys in elementary school? (3) During COVID-19, how did the roles of educational teachers and leaders change to meet the needs of students from low socioeconomic backgrounds? (4) How can the education system best support African American elementary boys in rural areas already at risk for fourth-grade failure syndrome in these unprecedented times?
The study revealed several academic and structural disparities in rural elementary education and that the social-emotional effects of the pandemic weighed heavier on the targeted population. The results showed that despite multiple adjustments made by educators, African American males still needed help, as the public education system is yet to implement strategies that best support African American boys with diminishing educational enthusiasm. The findings indicate the need for cultural awareness training, an engaging and inclusive curriculum, academic and mental health assessments and programs, pioneering parental support, building relationships, cultivating a positive school environment, and increasing teacher compensation and retention
Beyond Borders: A Phenomenological Case Study Of The Study Abroad Experiences Of Black, Undergraduate Hbcu Male Collegians
No full textBy employing a qualitative phenomenological case study, this research explored the learning, growth, and development of HBCU, Black male undergraduate collegians in the context of studying abroad. This study is significant in understanding how studying abroad informs HBCU, Black male students’ learning, growth and development and uncovers the intrinsic value that this student demographic stands to gain from participating in global experiences. Studying abroad informed the academic development, the personal development and the professional development of HBCU, Black male undergraduates. This qualitative study foregrounds literature that explores the study abroad experiences of Black American male undergraduates in the HBCU context.
Keywords: study abroad, HBCUs, HBCUs and Black males, HBCUs and Black male undergraduates, HBCUs and study abroa
(R2093) Fixed Point of Hybrid Jaggi-Meir-Keeler Type Multivalued Contraction
Full text linkOne of the most applicable results in metric fixed point theory is based on the contractive inequalities, including both rational and non-rational types. In this manuscript, a general idea under the name Jaggi-Meir-Keeler hybrid type multivalued contraction is introduced. We investigate the existence of fixed points for such operators in the setting of a complete metric space. The presented concept herein unifies the above-mentioned contractions and the corresponding invariant point results. A comparative nontrivial example is constructed to show the connection between the main idea in this paper and the related literature
Design And Synthesis Of Therapeutic Molecules Targeted At Metabolic Pathways Of Cancer And Lipid Signaling In Fungal Diseases
Full text linkCancer remains a leading cause of global mortality, with 20 million new cases and 9.7 million deaths recorded in 2022 (WHO, 2024). While advancements like nanoparticles and monoclonal antibodies offer new treatments, they often cause severe toxicity to normal cells. This study introduced novel thiamin-based compounds targeting enzymes critical for cancer cell proliferation. These compounds were synthesized via a three-step process involving tosylation, SN2 coupling with phenolic compounds, and subsequent reactions to form thiamin-like-phenol derivatives. Yields ranged from 50-70%, and Nuclear Magnetic Resonance (NMR) confirmed their structures. Anticancer activity was assessed by the National Cancer Institute. Separately, drug-resistant fungal infections, particularly from Candida glabrata, are a growing public health concern. This study addressed this issue by targeting Sec14 lipid-binding proteins, essential for lipid signaling, using small molecule inhibitors (SMIs) derived from piperazine. Results suggest Sec14 inhibition as a promising approach for developing next-generation antifungal therapies. In summary, this thesis presents two projects: synthesizing thiamine-phenol derivatives for cancer treatment and exploring SMIs as potential antifungal agents against C. glabrata.
Keywords: Cancer, phenols, Thiamin, drug resistance, piperazine, NMR
(R2116) The Novel Garima Distribution Properties and Nuclear Data Application
Full text linkThis research introduces a new two-parameter Marshall-Olkin Garima distribution model. The novel model has many sub-models that are useful in modeling real-life data, such as the extended Garima distribution, exponentiated Garima distribution, exponential distribution, Lindley distribution, Kumaraswamy Garima distribution, and normal distribution. The proposed model demonstrates a high level of suitability in modeling both reliability and survival data. It is flexible in accommodating various failures. The quantile function, density shapes, hazard rate functions, and order statistics are a few of the statistical features that have been explored. Maximum likelihood estimation methods were employed to estimate the parameters. Using five data sets, the suggested distribution’s flexibility was shown with nuclear reactions that are important systems in the field of nuclear physics. The proposed distribution was compared with its sub-models and other existing models. The findings demonstrated that, compared to the other competing distributions, the suggested distribution offered a superior fit to the data sets
Female Breast Cancer Survivor’s Perspective of Support Systems in Trinidad and Tobago
Full text linkGlobally, breast cancer is the most common cancer affecting women. The Cancer Registry of Trinidad and Tobago indicated that 45.9% of the breast cancer cases belonged to the African ethnicity, 27.5% Asian Indian, and 14.7% mixed ethnicity. Research on female breast cancer survivors\u27 perspectives on support systems and care within the Caribbean region is limited. Therefore, this study aims to examine female breast cancer survivors\u27 perspective of support systems in Trinidad and Tobago. We conducted a cross-sectional study with 74 cancer survivors attending support groups. To be eligible, the participants had to be females 18 years or older, residents of Trinidad and Tobago diagnosed with breast cancer, and attending any support group session. The participants were asked to complete a self-administered questionnaire with questions regarding sociodemographic characteristics, benefits of support groups, and perception of quality of care. All (n=74) participants indicated they were part of a support group at the facility or elsewhere. Most participants were between 46-65 years old. The three primary factors identified influencing initial participation in the support groups were feeling emotionally detached from family, having no family support, cancer education opportunities, and spiritual well-being. Providing support groups reduces stress and anxiety by creating a safe environment to maintain a healthier quality of life coping behavior and improve survival rate. More research is needed to provide continuous education on essential coping skills after a breast cancer diagnosis
