128 research outputs found
A Novel Algorithmic Approach using Little Theorem of Fermat For Generating Primes and Poulet Numbers in Order
Computer encryption are based mostly on primes, which are also vital for communications. The aim of this paper is to present a new explicit strategy for creating all primes and Poulet numbers in order up to a certain number by using the Fermats little theorem. For this purpose, we construct a set C of odd composite numbers and transform Fermats little theorem from primality test of a number to a generating set Q of odd primes and Poulet numbers. The set Q is sieved to separate the odd primes and the Poulet numbers. By this method, we can obtain all primes and Poulet numbers in order up to a certain number. Also, we obtain a closed form expression which precisely gives the number of primes up to a specific number. The pseudo-code of the proposed method is presented
Activity and stability of immobilized Candida rugosa lipase on chitosan coated Fe3O4 nanoparticles in aqueous and organic media
Fe3O4 (magnetite) nanoparticles were prepared by coprecipitation method, coated by chitosan and functionalized by glutaraldehyde. Lipase enzyme from Candida rugosa was immobilized on the prepared particles via cross linking reaction. Synthesis steps and characterization were examined by XRD, TEM, and FTIR.
The immobilization conditions were 10 mL of phosphate buffer (0.1 M, pH 6.5) containing 30 mg of functionalized magnetic chitosan nanoparticles and 2.0 mg·mL-1 of lipase, immobilization temperature of 4 ℃ and immobilization time of 1 h. Under these conditions, lipase was successfully immobilized with loading capacity of 87 mg/g.
The immobilized enzyme showed good operational and storage stability, where it remained stable after 30 days of storage at 4â—¦C.and retained about 61% of its initial activity after twenty repeated uses. Finally enzymatic catalyze synthesis of butyl and hexyl oleate at 40 â—¦C with shaking (200 rpm) was realized in n-hexane and confirmed by GC analysis
Adaptive admission/congestion control policy for hybrid TDMA/MC-CDMA integrated networks with guaranteed QoS
Future networks are expected to have the ability to accommodate variety of users, each with its own transmission characteristics and QoS requirements to be maintained. Compatible multiaccess system should provide the means to control (i.e. admission/congestion) the flow of traffic and at the same time maintain the QoS requirements. This paper investigates the performance of a novel measurement-based admission/congestion control policy over a hybrid TDMA/MC-CDMA platform. The practicality and several performance measures of the new system shall be analyzed analytically under a wide range of expected traffic characteristics (bit rate, transmission activities, etc.) for the future wireless networks. The adaptive admission/congestion control policy has effectively maintained the required QoS. It is worth to emphasize here that our proposed admission/congestion control polices apply preventive admission control as well as reactive congestion control
Synthesis and anti-mycobacterial evaluation of some new isonicotinylhydrazide analogues
AbstractThe synthesis of some new 3,4-disubstituted thiazolylideneisonicotinohydrazide derivatives 3a–k, 2-substituted thiazolidinylisonicotinamide derivatives 4a–d and pyrrolylisonicotinamide derivatives 5, 6 and 7 is described. The resulted compounds are evaluated for their in vitro antitubercular activity. The minimum inhibitory concentration (MIC) of compound 3g showed comparable in vitro activity to isoniazid against Mycobacterium tuberculosis H37Ra 7131 strain in concentration 9.77μg/mL
Age at puberty and accelerometer-measured physical activity:findings from two independent UK cohorts
Background It is unclear if puberty timing influences future physical activity (PA). Aim To investigate the association of puberty timing with PA across adolescence and adulthood. Subjects and methods Data were from two British cohorts. Participants from an adolescent birth cohort (females = 2349, males = 1720) prospectively reported age at menarche and voice break and had PA recorded by Actigraph accelerometers at ages 14 years and 16 years. A cohort of middle-aged and older adults (40–70 years; females = 48,282; males = 36,112) recalled their age at puberty and had PA (mean acceleration; mg) measured by AxivityAX3 accelerometers. Results After adjustment for age, education, smoking and BMI, per 1-year older age at menarche was associated with higher mean counts/minute at age 14 years (0.07 SD counts/minute; 95% CI = 0.04–0.11) with associations attenuated at age 16 years (0.02; −0.03–0.07). Differences in mean acceleration per older year at menarche were close to the null in women aged 40–49 years (0.02 mg; 0.01–0.03), 50–59 years (0.01; 0.00–0.02) and 60–70 years (0.01; 0.00–0.01). Age at voice break and PA associations were close to the null in both cohorts. Conclusion We found a positive association between puberty timing and PA in females which weakened at older ages and limited evidence of an association at any age in males
SOM Loss and Soil Quality in the Clear Creek, IA
The Clear Creek, IA Experimental Watershed (CCEW), which drains to the Iowa River, experiences severe surface erosion due to a combination of high slopes, erodible soils, and extensive agriculture. Concurrent with soil loss is the removal of Soil Organic Matter (SOM). High values of SOM have been related to soil quality; therefore, excessive SOM loss corresponds to degrading soil health. Soil quality assessments are important tools for evaluating management practices in agricultural systems; however, it is difficult to measure soil quality directly at the watershed scale because it varies with a number of site-specific soil characteristics. The coupling of soil surveys with GIS and Non-Point Source computer simulation models will effectively forecast the impacts of ever-changing management practices on soil quality at the watershed scale in less time. NPS models can be extended to evaluate the movement of additional particle-bound constituents like SOM, by incorporating erosion rates and enrichment ratios. The ANNualized AGricultural Non-Point Source pollution modeling system (AnnAGNPS) was used to evaluate upland erosion, enrichment ratios, and SOM loss at the watershed scale in the headwaters of the CCEW using current crop rotations. Gross erosion rates averaged 7.73 MT/ha/yr for individual cells within the watershed. In addition, enrichment ratios, which were determined using gross and net erosion values from AnnAGNPS, were coupled with an organic matter coverage map of the watershed to determine an SOM loss of0.41 MT/ha/yr, which was similar to the loss rates determined by AnnAGNPS (0.29 MT/ ha/yr). To understand the state of soil health in this watershed, the NRCS Soil Conditioning Index (SCI) was determined for the watershed. The average SCI for the watershed was 0.38, which suggests improving soil health conditions. This improvement is most probably due to conservation practices like reduced tillage
Study of DNA methyl transferase 3A mutation in acute myeloid leukemic patients
Background: Recent studies have shown that somatic mutations in DNA methyltransferase (DNMT3A) might affect the prognosis of AML.Objective: The aim of this work was to investigate the frequency and prognostic impact of the most frequent mutation of DNMT3A, R882H mutation in AML using simple and rapid molecular techniques.Patients and methods: We have used allele-specific blocker (ASB-PCR) and endonuclease restriction for the detection of DNMT3A R882H mutation in 56 adult patients with AML.Results: DNMT3A R882H mutation was detected in 7/56 (12.5%) of patients. R882H mutation positive patients were older compared to the wild-type AML (p = 0.08). No association was found with initial laboratory parameters including white blood cells (WBC), hemoglobin (HGB) and Bone marrow (BM) blasts (p > 0.05). Thirty-two patients (57.1%) achieved complete remission (CR), 11/56 (19.6%) died before day 28 induction death (ID) and 13/56 (23.2%) had resistant disease (RD). DNMT3A R882H positive patients were not different regarding the response to induction chemotherapy (CR) compared to the negative group (wild-type) (p > 0.05). Median follow-up period for all patients was 1.6 months, Overall survival (OS) was 65%, and the median was 9.89 months. OS of DNMT3A positive patients was not statistically significant compared to wild-type patients (p = 0.09). Disease free survival (DFS) was 54.6% for all patients, with no difference between wild and mutants (0.59) patients.Conclusion: DNMT3A R882H is a frequent mutation in adult de novo AML. The frequency of the mutation tends to increase with age. The two methods used in the study are easy to interpret and are recommended for rapid detection of the mutation required for risk stratification.Keywords: AML, DNMT3A, ASB-PCR, PCR-RFLP, Endonuclease restrictio
Markers of pubertal timing and leisure-time physical activity from ages 36 to 68 years: Findings from a British birth cohort
© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. Objectives We aimed to examine associations between markers of pubertal timing and leisure-time physical activity (LTPA) from ages 36 to 68 years in men and women from the Medical Research Council National Survey of Health and Development. Study design Pubertal timing was ascertained by physicians at age 14-15 years. Boys were grouped, based on their secondary sexual characteristics, as prepubescent, in early-stage puberty, advanced stage puberty or fully mature at age 14-15 years. Girls were grouped as reaching menarche ≤11, 12, 13 or ≥14 years. LTPA was reported at ages 36, 43, 53, 60-64 and 68 years and classified as active or inactive at each age. Associations were examined using standard and mixed-effects logistic regression models. Results Of 5362 singleton births recruited, 1499 men and 1409 women had at least one measure of LTPA and data on pubertal timing and selected covariates. When compared with men that were fully mature at age 14-15 years, those that were in advanced stage and early-stage puberty, but not the prepubescent stage, had lower likelihood of LTPA at younger but not older adult ages (p=0.06 for pubertal status-by-age at LTPA interaction in mixed-effects model). For example, fully adjusted ORs of LTPA (vs no LTPA) at ages 36 and 68 years, respectively, for advanced puberty versus fully mature were 0.69 (95% CIs 0.50 to 0.96) and 1.03 (0.72 to 1.47). Age at menarche was not associated with LTPA at any age (p interaction with age at LTPA=0.9). For example, OR (from mixed-effects model) of LTPA between 36 and 68 years was 1.23 (0.93, 1.63) for menarche at 13 vs ≤11 years. Conclusions In a nationally representative study, there was little evidence to suggest that pubertal timing was an important correlate of LTPA between ages 36 and 68 years. Maturity-related variations in adolescents' LTPA may be transitory and lose importance over time
Motor performance in early life and participation in leisure-time physical activity up to age 68 years
© 2018 The Authors.Paediatric and Perinatal Epidemiology Published by John Wiley & Sons Ltd Background: This study examined associations between motor performance in early life and leisure-time physical activity (LTPA) participation across adulthood, and whether these changed with age. Methods: Data were from 2526 participants from the Medical Research Council National Survey of Health and Development. Motor indicators were mother-reported ages at first standing and walking, teacher-rated games ability at age 13, and finger- and foot-tapping speed at age 15. LTPA was reported at ages 36, 43, 53, 60-64, and 68 years and classed at each age as none, moderate (1-4/mo), or regular (≥5/mo). Associations were examined using mixed-effects Poisson regression models with robust error variance. Results: Better ability at games and faster tapping speed were associated with more frequent participation in LTPA across adulthood, for example, fully adjusted relative risk of regular LTPA across adulthood (vs none) for above-average ability (vs below average or average) = 1.46 (95% CI 1.32, 1.61); and per 10-unit higher number of finger-taps/15 seconds = 1.04 (95% CI 1.02, 1.07). These associations did not vary by age (P ≥.33 for interactions with age at LTPA). Ages at reaching motor milestones were not associated with LTPA (eg, fully adjusted relative risk of regular LTPA across adulthood for walking ≤10 and ≥18 months (vs 11-17 months) were 1.01 (95% CI 0.86, 1.20) and 0.89 (95% CI 0.75, 1.06) respectively. Conclusions: Better ability at games and faster tapping speed in adolescence were associated with greater participation in LTPA throughout adult life; from age 36 up to age 68. Childhood motor skill interventions may therefore have the potential to promote lifelong LTPA
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