6,712 research outputs found

    Pair correlations and random walks on integers

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    Abstract The paper gives conditions for a sequence of fractional parts of real numbers ( { a n x } ) n = 1 ∞ ({anx})n=1∞\left( {\{ a_n x\} } \right)_{n = 1}^\infty to satisfy a pair correlation estimate. Here x is a fixed nonzero real number and ( a n ) n = 1 ∞ (an)n=1∞\left( {a_n } \right)_{n = 1}^\infty is a random walk on the integers.</jats:p

    The Effect of Shear Wall Openings on the Response Reduction Factor

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    This research attempts to investigate the effect of shear wall openings on the response reduction factor. Openings are commonly necessary because of other engineering disciplines’ requirements. When openings are modest in proportion to the size of the wall, their effects are frequently disregarded. On the other hand, when these openings are large or located in a high-risk area, they can have a significant impact. A broad literature review has been conducted in the present study. A verified comparative example consisting of eight stories was studied. Then, a numerical study has been conducted on two different model sets with 16 and 8 stories, which were designed according to the Egyptian code of loads, ECP-201 (2012), and checked according to the Euro code, EC8 (2004). ETABS software was used to conduct pushover analysis before and after applying different-sized openings. The ground-opening effect has also been studied. The results show that by increasing the opening area, the R-factor was reduced. It is more influenced by the opening height than the width, though. By increasing the number of stories, the reduction percentage in the R-Factor increased for openings that are less than 30% of the wall area. The R-factor increases slightly when half of the reinforcement bars are added. Doi: 10.28991/CEJ-2022-08-04-013 Full Text: PD

    Response Reduction Factor for Structures with Significant Irregularities on Different Soil Stratum

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    The ability of a structure to dissipate energy through inelastic behavior is reflected in the response reduction factor (R), which is influenced by redundancy, ductility, and overstrength. Accurate determination of R is crucial for seismic design. This study focuses on determining the response factor for reinforced concrete (RC) structures with various irregularities. Non-linear static pushover analysis using SAP2000 was employed for numerical simulations to assess the impact of soil-structure interaction (SSI). The analysis included elevational and in-plan irregularities, revealing that buildings with irregular vertical geometries have lower inelastic seismic capacities compared to regular buildings. Consequently, R should be reduced by 15–40% from the ECP 2020 standard before the design phase for such structures. Irregularity was found to have a significant impact on weak soil conditions (C), leading to a reduction in R of 20.3% and 13.1% for fixed and isolated supports, respectively, on loose soil. Additionally, stiffer base soils were associated with higher R values for the same structure. Doi: 10.28991/CEJ-2024-010-03-07 Full Text: PD

    Enhanced Parallel Hash Function Algorithm Based on 3C Construction (EPHFA-3C)

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    The hash function is a function that can convert data from variable size to fixed-size data that can be used in security of communication like, authentication, digital signature and integration. In this paper, a parallel, secure and fast hash function algorithm that is based on 3C construction is proposed. It is an enhancement for the MD construction. This enhancement makes the construction more resistant to the extension and multi-blocks attacks. The parallel structure of the algorithm improves the speed of hashing and reduces the number of operations. The simulation analysis such as hashes distribution, confusion and diffusion properties, and collision resistance are executed. Based on the results, our proposed hash algorithm is efficient, simple, and has strong security compared with some recent hash algorithms

    Bearing Capacity of Defective Reinforced Concrete Pile in Sand-model Study

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    Concrete piles that were poorly constructed or analyzed in their soil analyses may have structural or geotechnical defects. To examine such defects, an experimental study was conducted to investigate how a defective reinforced concrete pile behaved. These piles were installed and subjected to a compression axial load in the sand that had relative densities of 30%,60%, and 80%. The tests were performed using four concrete model piles: one intact pile and the other three piles had a structural defect (necking) at three different positions of the pile at (0.25 L from the top, center, and 0.25 L bottom). Geotechnical defect (soft layer or debris) was studied using Styrofoam layer at various vertical distances under the pile toe with Y/D = (0, 0.5, 1 and 1.5) D. The test results showed that the bearing capacity of the structural defect was the most in the case of a neck at 0.25 L from the bottom, followed by a neck at the center, and finally a neck at 0.25 L from the top. In the case of a geotechnical defect, the bearing capacity of the pile decreased with the decrease of the vertical distance between the soft layer and the pile toe

    Securing Body Area Networks with Fingerprint Cryptography and Authentication in MANET

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    Standard MANETs face issues like incorrect transmission and vulnerability to unauthorized node access, posing significant security concerns, especially regarding authentication procedures. To address these challenges, researchers are exploring innovative approaches to enhance authentication mechanisms within MANETs. In this paper, we present a novel solution integrating a Body Area Network (BAN) scheme to capture biomedical data from sensors such as ECG and EEG, facilitating data transmission across MANETs. Furthermore, we employ a hybrid Elgamal algorithm for encrypting biomedical data, bolstered by fingerprint biometrics to fortify the cryptographic process, enhancing network security. Additionally, we conduct comparative analyses, exploring different key sizes and generation techniques, and evaluating the system\u27s performance by calculating the False Acceptance Rate (FAR), False Rejection Rate (FRR), and Equal Error Rate (ERR) across varying threshold values for patient authentication. Moreover, we evaluate the Genuine Acceptance Rate (GAR) alongside the FAR specifically for genuine patients within the scheme, shedding light on the system\u27s authentication efficacy. Our findings reveal an optimal ERR of 0.375 with a threshold of 0.24, striking a balance between false acceptance and rejection rates. Furthermore, the GAR, representing the authentication rate, is determined to be 96.3%, underscoring the effectiveness of our proposed secure system. Through practical testing and analysis, our study demonstrates the resilience and robustness of the proposed multimodal biometric authentication system, offering a promising solution for secure communication in dynamic and resource-constrained MANET environments

    Suppression of eukaryotic initiation factor 4E prevents chemotherapy-induced alopecia

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    BACKGROUND: Chemotherapy-induced hair loss (alopecia) (CIA) is one of the most feared side effects of chemotherapy among cancer patients. There is currently no pharmacological approach to minimize CIA, although one strategy that has been proposed involves protecting normal cells from chemotherapy by transiently inducing cell cycle arrest. Proof-of-concept for this approach, known as cyclotherapy, has been demonstrated in cell culture settings. METHODS: The eukaryotic initiation factor (eIF) 4E is a cap binding protein that stimulates ribosome recruitment to mRNA templates during the initiation phase of translation. Suppression of eIF4E is known to induce cell cycle arrest. Using a novel inducible and reversible transgenic mouse model that enables RNAi-mediated suppression of eIF4E in vivo, we assessed the consequences of temporal eIF4E suppression on CIA. RESULTS: Our results demonstrate that transient inhibition of eIF4E protects against cyclophosphamide-induced alopecia at the organismal level. At the cellular level, this protection is associated with an accumulation of cells in G1, reduced apoptotic indices, and was phenocopied using small molecule inhibitors targeting the process of translation initiation. CONCLUSIONS: Our data provide a rationale for exploring suppression of translation initiation as an approach to prevent or minimize cyclophosphamide-induced alopecia.1U01 CA168409 - NCI NIH HHS; P01 CA 87497 - NCI NIH HHS; P30 CA008748 - NCI NIH HHS; MOP-106530 - Canadian Institutes of Health Research; P01 CA013106 - NCI NIH HH

    Real-Time PCR in the early detection of invasive fungal infection in immunodeficient infants and children

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    Background: Crucial to the diagnosis and effective therapy of invasive fungal infection (IFI) in the immunodeficient is the early identification of the causative agent especially in patients who lack clinical evidence of the disease. The standard methods for the detection of fungi in clinical specimens are direct microscopy and mycological culture. Microscopy often lacks a satisfactory sensitivity, whereas diagnosis by mycological culture often requires a long growth period. Studies have demonstrated the feasibility of detecting molds and yeast in a single reaction using the universal fungal primer. Objective: Evaluation of the role of real-time PCR in the early detection of fungal infection in immunodeficient patients with suspected IFI, who lack clinical evidence of the disease. Methods: This study included 30 immunodeficiency patients suspected of having IFI; 9 with primary and 21 with secondary immunodeficiency. All patients had at least one host factor, but no clinical criteria according to the EORTC-MSG definition of IFI. Twenty seven had fever and 3 had bronchopneumonia, both not responding to broad spectrum antibiotics for 96 hrs. or more. Blood samples were cultured for fungi and were analyzed with real-time PCR using universal fungal primers. For positive samples of fungal infection, aspergillus-specific primers were used for detection of aspergillus. Results: Seventeen patients (56.7%) proved to have IFI. Blood culture detected Candida in 2 patients only, while PCR detected Candida in another 9 and Aspergillus in 6, thus 15/17 patients with IFI (88%) were missed by blood culture. Blood culture for IFI diagnosis had a very low sensitivity (12%) but had a 100% specificity and positive predictive value. The results PCR did not vary with gender, degree of fever, immunodeficiency type, clinical presentation or current intake of antifungal treatment. Patients with proven IFI showed significantly increased CRP levels as compared to those without infection. Conclusion: Real-time PCR proved superior to culture in early diagnosis of IFI in patients with immunodeficiency before the appearance of the characteristic clinical and imaging signs. Reliance on blood culture alone at that stage would result in missing most of the positive cases with consequent delay in the initiation of specific treatment. Keywords: Invasive fungal infection, immunodeficiency, blood culture, real-time PCR, candida, aspergillusEgypt J Pediatr Allergy Immunol 2012;10(2):67-7
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