387 research outputs found
Honeyword Generation Using a Proposed Discrete Salp Swarm Algorithm
إن كلمات العسل (Honeywords) هي كلمات مرور مزيفة مرافقة لكلمة المرور الحقيقية والتي تدعى كلمة السكر. يعد نظام كلمات مرور العسل نظامًا فعالاً لاكتشاف اختراق كلمات المرور مصمم لاكتشاف اختراق كلمة المرور بسهولة من أجل تحسين أمان كلمات المرور المشفرة. لكل مستخدم ، سيكون لملف كلمة المرور الخاص بنظام الكلمات العسلية كلمة مرور واحدة حقيقية مشفرة مصحوبة بالعديد من كلمات المرور المزيفة المشفرة. إذا قام شخص دخيل بسرقة ملف كلمات المرور من النظام ونجح في اختراق كلمات المرور محاولا تسجيل الدخول إلى حسابات المستخدمين ، فسيكتشف نظام كلمات المرور هذه المحاولة من خلال مدقق العسل. (Honeychecker) مدقق العسل هو خادمًا إضافيًا يميز كلمة المرور الحقيقية عن كلمات المرور المزيفة ويطلق إنذارًا إذا قام شخص دخيل بتسجيل الدخول باستخدام كلمة مرور العسل. تم اقتراح العديد من طرق توليد كلمات العسل خلال البحوث السابقة، مع وجود قيود على عمليات إنشاء كلمات العسل الخاصة بهم ، ونجاح محدود في توفير جميع ميزات كلمات العسل المطلوبة ، والتعرض للعديد من مشكلات كلمات العسل. سيقدم هذا العمل طريقة جديدة لتوليد كلمات العسل تستخدم خوارزمية سرب عنب البحر المتقطعة. خوارزمية سرب عنب البحر هي خوارزمية تحسين مستوحاة من الأحياء تحاكي سلوك سرب عنب البحر في بيئتها الطبيعية. تم استخدام خوارزمية سرب عنب البحر لحل مجموعة متنوعة من مشاكل التحسين. ستعمل طريقة توليد الكلمات العسلية المقترحة على تحسين عملية توليد كلمات العسل وتحسين ميزات كلمات العسل والتغلب على عيوب التقنيات السابقة. ستوضح هذه الدراسة العديد من الاستراتيجيات السابقة لتوليد الكلمات العسلية، ووصف الطريقة المقترحة، وفحص النتائج التجريبية، ومقارنة طريقة إنتاج كلمات العسل الجديدة بالطرق السابقة.Honeywords are fake passwords that serve as an accompaniment to the real password, which is called a “sugarword.” The honeyword system is an effective password cracking detection system designed to easily detect password cracking in order to improve the security of hashed passwords. For every user, the password file of the honeyword system will have one real hashed password accompanied by numerous fake hashed passwords. If an intruder steals the password file from the system and successfully cracks the passwords while attempting to log in to users’ accounts, the honeyword system will detect this attempt through the honeychecker. A honeychecker is an auxiliary server that distinguishes the real password from the fake passwords and triggers an alarm if intruder signs in using a honeyword. Many honeyword generation approaches have been proposed by previous research, all with limitations to their honeyword generation processes, limited success in providing all required honeyword features, and susceptibility to many honeyword issues. This work will present a novel honeyword generation method that uses a proposed discrete salp swarm algorithm. The salp swarm algorithm (SSA) is a bio-inspired metaheuristic optimization algorithm that imitates the swarming behavior of salps in their natural environment. SSA has been used to solve a variety of optimization problems. The presented honeyword generation method will improve the generation process, improve honeyword features, and overcome the issues of previous techniques. This study will demonstrate numerous previous honeyword generating strategies, describe the proposed methodology, examine the experimental results, and compare the new honeyword production method to those proposed in previous research
Modulations of cell cycle checkpoints during HCV associated disease
Background
Impaired proliferation of hepatocytes has been reported in chronic Hepatitis C virus infection. Considering the fundamental role played by cell cycle proteins in controlling cell proliferation, altered regulation of these proteins could significantly contribute to HCV disease progression and subsequent hepatocellular carcinoma (HCC). This study aimed to identify the alterations in cell cycle genes expression with respect to early and advanced disease of chronic HCV infection. Methods
Using freshly frozen liver biopsies, mRNA levels of 84 cell cycle genes in pooled RNA samples from patients with early or advanced fibrosis of chronic HCV infection were studied. To associate mRNA levels with respective protein levels, four genes (p27, p15, KNTC1 and MAD2L1) with significant changes in mRNA levels (\u3e 2-fold, p-value \u3c 0.05) were selected, and their protein expressions were examined in the liver biopsies of 38 chronic hepatitis C patients. Results
In the early fibrosis group, increased mRNA levels of cell proliferation genes as well as cell cycle inhibitor genes were observed. In the advanced fibrosis group, DNA damage response genes were up-regulated while those associated with chromosomal stability were down-regulated. Increased expression of CDK inhibitor protein p27 was consistent with its mRNA level detected in early group while the same was found to be negatively associated with liver fibrosis. CDK inhibitor protein p15 was highly expressed in both early and advanced group, but showed no correlation with fibrosis. Among the mitotic checkpoint regulators, expression of KNTC1 was significantly reduced in advanced group while MAD2L1 showed a non-significant decrease. Conclusion
Collectively these results are suggestive of a disrupted cell cycle regulation in HCV-infected liver. The information presented here highlights the potential of identified proteins as predictive factors to identify patients with high risk of cell transformation and HCC development
Smart Energy Management System for Minimizing Electricity Cost and Peak to Average Ratio in Residential Areas with Hybrid Genetic Flower Pollination Algorithm
Demand Side Management (DSM) plays a significant role in the smart grid to minimize Electricity Cost (EC). Home Energy Management Systems (HEMSs) have recently been studied and proposed explicitly for HEM. In this paper, we propose a novel nature-inspired hybrid Genetic Flower Pollination Algorithm (GFPA) to minimize cost with an affordable delay in appliance scheduling. Our proposed GFPA algorithm combines elements of the Genetic Algorithm (GA) and Flower Pollination Algorithm (FPA) to create a hybrid approach. To assess the effectiveness of the proposed algorithm, we consider a scalable town consisting of 1, 10, 30, and 50 homes, respectively. The proposed solution finds an optimal scheduling pattern that simultaneously minimizes EC and Peak to Average Ratio (PAR) while maximizing User Comfort (UC). We assume that all homes are homogeneous regarding appliances and power consumption patterns. Simulation results show that our proposed scheme GFPA performs better when applying Critical Peak Pricing (CPP) signal using different Operational Time Intervals (OTIs) and compared with unscheduled, GA, and FPA-based solutions in terms of reducing cost since they achieve on average 98%, 36%, 23%, and 22%, respectively. Similarly, PAR averages 98%, 36%, 59%, and 55%, respectively. While, UC comparing to GA and FPA, are around 88%, 48%, and 63%, respectively. Our proposed scheme achieves better results by applying Real Time Pricing (RTP) signals and different OTIs. As these schemes, i.e., unscheduled, GA, FPA, and GFPA, achieve cost on average 92%, 50%, 29%, and 28%, respectively. While PAR on average 94%, 39%, 62%, and 56%, and UC for GA, FPA, and GFPA on average 98%, 52%, and 49%, respectively. Overall, ourproposed GFPA algorithm offers a more effective solution for minimizing EC with an affordable delay in appliance scheduling while considering PAR and UC
Denoising Two-Photon Calcium Imaging Data
Two-photon calcium imaging is now an important tool for in vivo imaging of biological systems. By enabling neuronal population imaging with subcellular resolution, this modality offers an approach for gaining a fundamental understanding of brain anatomy and physiology. Proper analysis of calcium imaging data requires denoising, that is separating the signal from complex physiological noise. To analyze two-photon brain imaging data, we present a signal plus colored noise model in which the signal is represented as harmonic regression and the correlated noise is represented as an order autoregressive process. We provide an efficient cyclic descent algorithm to compute approximate maximum likelihood parameter estimates by combing a weighted least-squares procedure with the Burg algorithm. We use Akaike information criterion to guide selection of the harmonic regression and the autoregressive model orders. Our flexible yet parsimonious modeling approach reliably separates stimulus-evoked fluorescence response from background activity and noise, assesses goodness of fit, and estimates confidence intervals and signal-to-noise ratio. This refined separation leads to appreciably enhanced image contrast for individual cells including clear delineation of subcellular details and network activity. The application of our approach to in vivo imaging data recorded in the ferret primary visual cortex demonstrates that our method yields substantially denoised signal estimates. We also provide a general Volterra series framework for deriving this and other signal plus correlated noise models for imaging. This approach to analyzing two-photon calcium imaging data may be readily adapted to other computational biology problems which apply correlated noise models.National Institutes of Health (U.S.) (DP1 OD003646-01)National Institutes of Health (U.S.) (R01EB006385-01)National Institutes of Health (U.S.) (EY07023)National Institutes of Health (U.S.) (EY017098
Localization of phonons in mass-disordered alloys: A typical medium dynamical cluster approach
The effect of disorder on lattice vibrational modes has been a topic of interest for several decades. In this work, we employ a Green\u27s function based approach, namely, the dynamical cluster approximation (DCA), to investigate phonons in mass-disordered systems. Detailed benchmarks with previous exact calculations are used to validate the method in a wide parameter space. An extension of the method, namely, the typical medium DCA (TMDCA), is used to study Anderson localization of phonons in three dimensions. We show that, for binary isotopic disorder, lighter impurities induce localized modes beyond the bandwidth of the host system, while heavier impurities lead to a partial localization of the low-frequency acoustic modes. For a uniform (box) distribution of masses, the physical spectrum is shown to develop long tails comprising mostly localized modes. The mobility edge separating extended and localized modes, obtained through the TMDCA, agrees well with results from the transfer matrix method. A reentrance behavior of the mobility edge with increasing disorder is found that is similar to, but somewhat more pronounced than, the behavior in disordered electronic systems. Our work establishes a computational approach, which recovers the thermodynamic limit, is versatile and computationally inexpensive, to investigate lattice vibrations in disordered lattice systems
Effect of Helicobacter pylori and its virulence factors on portal hypertensive gastropathy and interleukin (IL)-8, IL-10, and tumor necrosis factor-alpha levels
Background/Aim: We aimed to assess the influence of Helicobacter pylori and its virulent factors, cytotoxin associated gene (cag) A and E, on portal hypertensive gastropathy (PHG) and the levels of interleukin (IL)-8, IL-10, and tumor necrosis factor-alpha (TNF-α).
Patients and Methods: The patients with cirrhosis underwent screening endoscopy and the lesions related to PHG were graded. Biopsies were obtained for histology, and polymerase chain reaction (PCR) of H. pylori 16S rRNA, cagA, cagE, and tissue cytokine levelswas carried out. Absent or mild PHG was compared with moderate to severe PHG.
Results: One hundred and forty patients with cirrhosis were studied; males numbered 92 and the mean age of the patients was 50.3 ± 12.0 years, H. pylori positivity in 87 (62.1%) patients was associated with male gender (P = 0.032), younger age (P = 0.029), hepatitis D etiology (P = 0.005), higher serum albumin (0.000), lower Child Pugh score (P = 0.001), and lower portal vein diameter (P = 0.001). There was no significant difference in the levels of TNF-α and IL-8. However, a decrease in the anti-inflammatory cytokine IL-10 was noted with moderate to severe gastropathy. Four H. pylori strains were positive for both cagA and cagE, while four were positive for cagA only. All the four patients with both virulent factors had mild gastropathy only.
Conclusion: The presence of H. pylori infection neither affected the severity of PHG nor augmented the IL-8 and TNF-α levels. There was a decline of virulent H. pylori strains and IL-10 levels in patients with advanced PHG
Non-cell autonomous OTX2 transcription factor regulates anxiety-related behaviors in the mouse
The Otx2 homeoprotein transcription factor is expressed in the dopaminergic neurons of the ventral tegmental area, a mesencephalic nucleus involved in the control of complex behaviors through its projections to limbic structures, including the ventral hippocampus, amygdala, nucleus accumbens and prefrontal cortex. We find adult mice heterozygous for Otx2 show a hypoanxious phenotype in light-dark box and elevated plus maze paradigms. However, the number of dopaminergic neurons, the integrity of their axons, their projection patterns in target structures, and the amounts of dopamine and dopamine metabolites in targets structures were not modified in the Otx2 mutant. Because OTX2 is expressed by the choroid plexus, secreted into cerebrospinal fluid and transferred to parvalbumin interneurons of the cortex, hippocampus, and amygdala, we investigated if the hypoanxiety of Otx2 heterozygous mice could result from the decreased synthesis of Otx2 in the choroid plexus. Indeed, hypoanxious phenotype was reversed by the overexpression of Otx2 specifically in choroid plexus of adult Otx2 heterozygous mice, while hypoanxious phenotype could be induced in adult wild type mice by lowering OTX2 levels in the cerebrospinal fluid. Taken together, OTX2 synthesis by the choroid plexus followed by its secretion into the cerebrospinal fluid is an important regulator of the anxiety phenotype in the mouse. All rights reserved. No reuse allowed without permission
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
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