Allegheny College DSpace Repository
Not a member yet
38403 research outputs found
Sort by
The image of sahabah in Twelver Shia in the historical process
No full textŞiî-İmâmî geleneğin inanç sisteminin temelinde nas ile tayin edilmiş bir imam düşüncesi bulunmaktadır. Bu nazariyeye göre Hz. Peygamberden sonra halife seçilen Hz. Ebû Bekir ve kendisinden sonra hilâfete geçenlerin halifelikleri geçersizdir. Bundan dolayı da Hz. Ali’nin imâmet/hilâfet hakkına aykırı hareket eden kişiler sahâbe vasfını kaybetmiştir. İlâhî imâmet nazariyesinin ispat edilebilmesi için gerek Kur'ân ayetleri gerekse tarihî olaylar bağlamlarından koparılarak mezhebî bakış açısıyla çok farklı şekillerde yorumlanmıştır. Şiî-İmâmî geleneğin sahâbe algısının şekillenmesinde siyasî bir mesele olan imâmet düşüncesi merkezi bir rol oynamıştır. Şiî-Sünnî öteki algısının oluşumunda da sahâbe konusu en önemli etkenlerdendir. Şîa’nın sahâbeyi sıradanlaştırması ve kimi zaman tekfir etmesi Ehl-i Sünnet’in onların tamamını adil kabul edip koruma çemberinin içine almasını beraberinde getirmiştir. Çalışmamızda İmâmet nazariyesinden dolayı sahâbenin İmâmiyye Şîası tarafından olumsuz bir şekilde ele alındığı görülmüştür. Hicrî I. asrın son çeyreğinde tarih sahnesine çıkan Şîa’nın ve onun en büyük kolu İmâmiyye’nin bir taraftan kurumsallaşmasını tamamlarken öteki taraftan başta Gulât-ı Şîa’nın etkisi olmak üzere siyasî sebeplerden dolayı olumsuz bir sahâbe algısını düşünce sistemine eklediği görülmüştür. İmâmiyye Şîası sahâbeye yönelik iddialarını savunurken siyasî yönetimlerin tavrını esas almıştır. Siyaseten güçlü oldukları dönemlerde sahâbeyi daha rahat eleştirirken zayıf oldukları dönemlerde bu tavırlarında yumuşamalar meydana gelmiştir. Tarihsel süreçte Emevîler, Abbâsîler, Büveyhîler, İlhanlılar, Safevîler ve sonraki dönemlerde bu tavrın devam ettiği görülmüştür. Tezimiz İmâmiyye Şîasın’daki sahâbe tasavvurunun tarihsel arka planını ve değişim sürecini detaylı ve bütüncül bir biçimde incelemeyi hedeflemiştir.The basis of the belief system of the Shiite-Imam tradition is the idea of an imam appointed by the text. According to this theory, the caliphates of Abu Bakr, who was elected as the caliph after the Prophet, and those who succeeded him are invalid. For this reason, those who acted against Ali's right to imamate/caliphate lost their qualifications as companions. In order to prove the theory of divine imamate, both the Quranic verses and historical events were taken out of their context and interpreted in many different ways from a sectarian perspective. The idea of imamate, which is a political issue, played a central role in shaping the perception of the companions in the Shiite-Imam tradition. The issue of companions is one of the most important factors in the formation of the Shiite-Sunni perception of the other. The Shia's vulgarization of the Companions and sometimes their excommunication caused the Ahl al-Sunnah to accept all of them as just and take them under their protection. In our study, it was seen that the companions were handled negatively by the Twelver Shia due to the imamate theory. It has been observed that Shia and its largest branch, Imamiyyah, which emerged on the stage of history in the last quarter of the 1st century Hijri, completed their institutionalization on the one hand, and on the other hand, added a negative perception of the companions to their thought system due to political reasons, especially the influence of Ghulat Shia. While defending their claims against the companions, the Twelver Shia took the attitude of the political administrations as a basis. While they criticized the Companions more easily in the periods when they were politically strong, their attitude softened in the periods when they were weak. In the historical process, it has been seen that this vision continued in the Umayyads, Abbasids, Buwayhids, Ilkhanids, Safavids and subsequent periods. Our thesis aims to examine the historical background and change process of the companions in Imamiyyah Shia in a detailed and holistic manner
Survival outcomes in patients with squamous cell carcinoma of the urinary bladder: A propensity score-matched analysis
No full textBackground and Objective: Bladder cancer (BC) is the ninth most common malignancy worldwide. Squamous cell carcinoma (SqCC), a rare histological variant, accounts for approximately 2-5% of all BC cases. Compared to urothelial carcinoma, the predominant subtype, research on SqCC remains limited and shows inconsistent findings regarding prognosis. This study aimed to compare survival outcomes between patients with SqCC and those with pure urothelial carcinoma (PUC). Methods: This retrospective, observational study analyzed pathology reports from 2549 transurethral resections of bladder tumors and 632 cystectomies performed at our institution between 1 December 2010 and 31 December 2023. Following pathological re-evaluation, 33 patients with SqCC and 132 with PUC were identified. After 1:3 propensity score matching, 20 patients with SqCC and 58 with PUC were included in the final analysis. Demographic, clinicopathological features, and survival outcomes were compared between groups. Results: The median follow-up was 2.31 years (range: 0.17-13.50). No significant differences in baseline demographic or clinical characteristics were observed, except for the type of surgery. Kaplan-Meier analysis demonstrated no significant differences in disease-free survival (DFS; p = 0.961) or overall survival (OS; p = 0.847) between SqCC and PUC groups. Multivariate Cox regression analysis identified T stage, nodal involvement, and adjuvant chemotherapy (CT) as independent predictors of DFS, while sex and metastasis at diagnosis were significant predictors of OS. Conclusion: Survival outcomes (DFS and OS) did not significantly differ between patients with SqCC and patients with PUC. Prognosis was more closely associated with disease stage at diagnosis, sex, and adjuvant CT. Further large-scale studies are warranted
Effect of heat input on martensitic stainless steel laser clad characteristics on ductile cast iron
No full textLaser cladding is a surface modification technique used for repairing and enhancing substrate materials by depositing powder layers with a laser beam. This study investigates the effects of laser power, scanning speed, and heat input on the porosity, microhardness, microstructure, residual stress, and thermal behavior of Metco 42C martensitic stainless steel powder deposited on FGS600-3A ductile cast iron used in sheet metal forming molds. Characterization was conducted using optical microscopy, SEM, EDS, digital image processing, thermal imaging, and residual stress measurements via XRD and ESPI methods. The cladding zone exhibited a columnar dendritic martensitic structure, with coarser dendrites observed at high heat input (316.67 J/mm) compared to low heat input (78.57 J/mm). Increased heat input significantly affected porosity, with pore formation mechanisms including gas entrapment, lack of fusion, balling effect, and thermal contraction. Microhardness variation was attributed to carbon diffusion from the substrate, with a peak hardness of 946 HV0.05 in the transition zone. Residual stress analysis revealed compressive stress dominance at high heat input and tensile stress at low heat input. Thermal analysis indicated a peak temperature of 1771 degrees C in the first cladding layer, which also exhibited a higher risk of cracking. These findings highlight the influence of heat input on the mechanical and microstructural properties of the cladding, providing insights for optimizing laser cladding processes in industrial applications
Deficit thinking scale for teachers: A validity and reliability study in turkish context
No full textDeficit thinking is one of the theories developed to explain achievement gaps among different student groups. It attributes academic failure to perceived deficiencies within students, disregarding the role of structural inequalities in education. This study aims to develop a valid and reliable scale to measure Turkish teachers' attitudes toward deficit thinking, which has not previously been operationalized in T & uuml;rkiye. Based on a rigorous scale development process, including literature review, expert consultation, pilot testing, exploratory and confirmatory factor analyses, the final version of the scale consists of 22 items and five dimensions. Exploratory factor analysis (n = 323; KMO = .87; Bartlett's chi(2) = 4983.99, p < .001) revealed a five-factor structure (Blaming the Environment, Educability, Oppression, Blaming the Victim, and Pseudoscience) that explained 66.13% of the total variance. Confirmatory factor analysis (n = 569) supported this structure with good model fit (chi(2)/ df = 2.58, CFI = .95, TLI = .95, RMSEA = .053, SRMR = .043). The scale demonstrated strong reliability (Cronbach's alpha = .86 overall; .93, .93, .88, .87, .91 for subscales). Item 20 is reverse-scored; total scores range from 22 to 110, with higher scores indicating stronger deficit-oriented attitudes. This context-specific scale offers a robust tool for investigating deficit-oriented beliefs in educational settings and provides a foundation for further research, teacher training, and policy development
Advancing diversity, sustainability, and reform in global higher education
No full textAdvancing diversity, sustainability, and reform in global higher education becomes essential in addressing the current challenges. As institutions deal with issues of inequality, climate change, and shifting labor markets, there is a growing demand for inclusive educational models that respond to a changing world. Promoting diversity ensures students have equal opportunities to thrive, while integrating sustainability into curricula and campus operations prepares future leaders to tackle environmental and social issues. Reforming structures and practices make higher education more accessible, relevant, and impactful. These efforts reshape the global educational landscape toward a more equitable and resilient future. Advancing Diversity, Sustainability, and Reform in Global Higher Education explores how global higher education institutions address issues of inclusion, environmental responsibility, and structural reform to meet contemporary social and economic challenges. It examines the strategies, policies, and innovations being implemented to foster diverse learning environments, promote sustainability, and modernize global academic systems. This book covers topics such as sustainable development, international students, and curriculum development, and is a useful resource for educators, policymakers, academicians, researchers, and scientists
Genomic analysis of Massilia antarctica subsp. insulae subsp. nov., a violacein- and aminochelin-producing bacterium isolated from Horseshoe Island, Antarctica
No full textMicroorganisms isolated from polar regions are recognized for their considerable capability to encode unique proteins and metabolic pathways with importance for biotechnological applications. Specifically, microorganisms capable of generating pigments possessing antioxidant and antimicrobial properties as a strategy for survival amidst challenges like high ultraviolet radiation, low temperature, oxidative stress and microbial competition are noteworthy. In this research, we discovered a new subspecies of the species Massilia antarctica, designated as H27-R4T, which was isolated from a soil sample collected at Horseshoe Island in Antarctica. Strain H27-R4T is a purple-pigmented, rod-shaped, Gram-negative, and aerobic bacterium. Pairwise comparison of the 16S rRNA genes showed that the strain shares 100% identity with the type strain of Massilia antarctica P8398T and Massilia frigida CCM 8695 T, while the highest average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of 97.1% and 73.7%, respectively, were observed between strain H27-R4T and M. antarctica P8398T. The whole-genome analysis revealed a metabolic potential in terms of secondary metabolism, resistance to antimicrobials and heavy metals, adaptation to cold environments, stress response mechanisms and metabolism of aromatic compounds. In addition, the strain exhibited pathways for violacein and aminochelin biosynthesis. Phylogenomic analyses confirmed that strain H27-R4T represents a novel subspecies for which the name Massilia antarctica subsp. insulae subsp. nov. is proposed.Presidency of The Republic of TurkiyeMinistry of Industry and Technolog
Regionel anestezi tekniklerinin sleeve gastrektomide ağrı kontrolü ve opioid tüketimi üzerindeki etkisi
No full textThis study aims to evaluate the effectiveness of erector spinae block (ESP) and transversus abdominis plane (TAP) blocks in reducing postoperative opioid requirements and enhancing pain control in laparoscopic sleeve gastrectomy (LSG) patients. This retrospective study included 90 patients undergoing LSG. The patients were equally allocated into three groups—ESP block, TAP block, and control (no regional anesthesia applied)—with 30 patients in each group. During the allocation process, patients were matched for age and gender. Pain levels were assessed using the Visual Analog Scale (VAS) at 0, 2, 4, 8, 12, and 24 hours postoperatively. Opioid consumption, side effects, patient, and surgeon satisfaction were recorded. Statistical analyses were conducted to compare pain scores, opioid use, and satisfaction levels among the groups. The ESP block group reported the lowest VAS scores, indicating superior pain control. Opioid consumption was significantly reduced in both ESP and TAP block groups compared to the control group, with the ESP group showing the greatest reduction. There was a significant relationship between the amount of opioid used and side effects. Patient satisfaction was highest in the ESP block group, followed by the TAP block group, and lowest in the control group. The ESP and TAP blocks are effective in reducing postoperative opioid consumption and providing better pain control in LSG patients. The ESP block, in particular, offers superior analgesia and higher patient satisfaction compared to the TAP block and no block.Bu çalışma, laparoskopik mide tüpü gastrektomi (LSG) hastalarında erector spinae bloğu (ESP) ve transversus abdominis plane (TAP) bloklarının postoperatif opioid gereksinimlerini azaltma ve ağrı kontrolünü iyileştirme etkinliğini değerlendirmeyi amaçlamaktadır. Bu retrospektif çalışmaya, LSG uygulanan 90 hasta dahil edilmiştir. Hastalar, her bir grup için 30 hasta olacak şekilde üç gruba eşit olarak dağıtılmıştır—ESP bloğu, TAP bloğu ve kontrol (regionel anestezi uygulanmayan)—ve hastalar yaş ve cinsiyet açısından eşleştirilmiştir. Ağrı düzeyleri, postoperatif 0, 2, 4, 8, 12 ve 24 saatlerde Görsel Analog Skala (VAS) kullanılarak değerlendirilmiştir. Opioid tüketimi, yan etkiler, hasta ve cerrah memnuniyeti kaydedilmiştir. Gruplar arasında ağrı skorları, opioid kullanımı ve memnuniyet düzeylerini karşılaştırmak için istatistiksel analizler yapılmıştır. ESP grubu, kontrol grubuna kıyasla anlamlı şekilde daha düşük VAS skorları göstermiştir. ESP bloğu grubunda en düşük VAS skorları bildirilmiş, bu da üstün ağrı kontrolünü göstermektedir. Opioid tüketimi, ESP ve TAP bloğu gruplarında kontrol grubuna göre anlamlı şekilde azalırken, ESP grubunda en büyük azalma gözlemlenmiştir. Kullanılan opioid miktarı ile yan etkiler arasında anlamlı bir ilişki bulunmuştur. Hasta memnuniyeti, en yüksek ESP bloğu grubunda, ardından TAP bloğu grubunda ve en düşük kontrol grubunda kaydedilmiştir. ESP ve TAP blokları, LSG hastalarında postoperatif opioid tüketimini azaltmada ve daha iyi ağrı kontrolü sağlamada etkilidir. Özellikle ESP bloğu, TAP bloğuna ve herhangi bir blok uygulanmayan gruba kıyasla üstün analjezi ve daha yüksek hasta memnuniyeti sunmaktadır
Locoregional treatment in de novo bone-only metastatic breast cancer: Prospective, multi-institutional real-world data, BOMETIN, Protocol MF14-1a
No full textIntroduction: The impact of locoregional treatment (LRT) on survival in de novo bone-only metastatic breast cancer (dnBOMBC) is controversial. This study aims to assess the effect of LRT on survival, utilizing international, prospectively acquired data in this cohort of patients. Materials and Methods: Patients with dnBOMBC were divided into two groups: those receiving systemic therapy only (ST) and those undergoing LRT. Further, patients who received LRT were divided into two subgroups: those who received ST after LRT (LRT+ST group) and those who received ST prior to LRT (ST+LRT group). Factors associated with disease progression, including solitary or multiple bone metastases, were analyzed. Results: There was a total of 744 patients with dnBOMBC treated at each of the participating institutions between 2014 and 2022, with 372 (50%) participants in each arm. Median follow-up was 48 months (32–66, 25–75%). Patients in the LRT group were significantly younger than the ST group [50 (42, 60) vs. 55 (44, 66), p = 0.0001]. There were no significant differences in grade, HER2 status, triple-negative status, receipt of hormonal therapy, or intervention to metastatic sites. During follow-up, 58% (n = 217) of patients in the ST group and 32% (n = 120) of patients in the LRT group died (p < 0.001). Local progression was observed in 20% of the patients in the ST group, whereas 9% progressed in the LRT group (p = 0.0001). Systemic progression occurred more in the ST group; 66% (n = 244) compared to 41% (n = 152) of patients in the LRT group (p < 0.001). The hazard of death was 64% lower in the LRT group than in the ST group (HR: 0.36, 95% CI: 0.29–0.45, p < 0.0001). The burden of metastatic disease differed significantly between the two groups, with a higher rate of solitary bone metastases in the LRT group compared to the ST group (50% vs. 24%, p < 0.001). However, the LRT group had better overall survival (OS) for both solitary (HR: 0.38, 95% Cl: 0.26–0.55) and multiple (HR: 0.38, 95% Cl: 0.29–0.51) bone metastasis patients. Within the LRT group, survival rates were similar whether the breast surgery was performed before or after ST. Multivariate Cox analysis showed that LRT and ER/PR positivity significantly decrease the hazard of death (p < 0.05). Conclusions: Analysis of this large multi-institutional patient cohort provides further evidence that LRT is associated with longer OS and lower locoregional recurrence rates in patients with dnBOMBC. In breast cancer patients with bone-only metastases at presentation, the decision for LRT should be made through a multidisciplinary approach with consideration of surgical therapy at the primary tumor
Experimental and simulation acoustic study of rectangular plate vibration for exciter speaker
No full textThis study investigates the vibrational behavior of 15×15 cm rectangular metal and plastic plates using both finite element analysis (FEA) and experimental measurements. The research aims to compare simulation results with real-world experimental data to validate the accuracy of numerical models in predicting plate vibrations under excitation from a speaker. Initially, modal analysis is performed via FEA to determine the natural frequencies and mode shapes of the plates. The numerical simulations are conducted using appropriate boundary conditions and material properties to ensure realistic modeling. Subsequently, an experimental setup is designed to excite the plates using a modal hammer, modal shaker and sound exciter. Thus, the resulting vibrations are measured using accelerometers and acoustic microphone. The measured frequency response is then compared with the FEA predictions to assess discrepancies and potential sources of error. Results indicate that while the FEA models provide a good approximation of the experimental outcomes, differences arise due to material imperfections, boundary condition assumptions, and damping effects not fully captured in simulations. The findings contribute to a better understanding of plate vibration characteristics, with implications for applications in acoustics, structural engineering, and materials science
A design method for developing rubber anti-vibration mounts for high frequency applications in EV suspension systems
No full textRapid development of industries such as aerospace, defense and automotive has made vibration control and isolation a critical issue. Electrical Vehicles (EV), in automotive industry, brings additional engineering problems for anti-vibration applications in High Frequency Range (50-2500Hz). Isolating the vibration on EV engine requires additional design and material development activities comparing with Internal Combustion Engines (ICE).For long time viscoelastic materials such as Rubber are widely in use for vibration isolation applications. In this study, high-frequency behavior of viscoelastic materials was analyzed virtually in Finite Element Analysis by using DMA and RPA test results as material inputs. Frequency dependent responses of the rubber mounts has been examined. The obtained storage and loss modulus data in frequency domain were used to simulate high frequency behaviors and modify the frequency band of isolators that resonates at high frequencies. Parametrical geometry modification has been iterated until required performance obtained.To overcome the difficulties for obtaining Storage and Loss modules at high frequencies, additional studies were conducted by using machine learning methods to increase the accuracy of FEA results. Proposed approach provides promising results to get quick responses depending on design modifications. This makes the selection of optimum viscoelastic materials quicker and provides a design method for high frequency applications