Displaying publications 81 - 100 of 1412 in total

  1. Apenteng OO, Ismail NA
    PLoS ONE, 2014;9(6):e98288.
    PMID: 24911023 DOI: 10.1371/journal.pone.0098288
    Previous models of disease spread involving delay have used basic SIR (susceptible--infectious--recovery) formulae and approaches. This paper demonstrates how time-varying SEIRS (S--exposed--I - R - S) models can be extended with delay to produce wave propagations that simulate periodic wave fronts of disease spread in the context of population movements. The model also takes into account the natural mortality associated with the disease spread. Understanding the delay of an infectious disease is critical when attempting to predict where and how fast the disease will propagate. We use cellular automata to model the delay and its effect on the spread of infectious diseases where population movement occurs. We illustrate an approach using wavelet transform analysis to understand the impact of the delay on the spread of infectious diseases. The results indicate that including delay provides novel ways to understand the effects of migration and population movement on disease spread.
    Matched MeSH terms: Time Factors
  2. Tabassum N, Rafique U, Balkhair KS, Ashraf MA
    Biomed Res Int, 2014;2014:831989.
    PMID: 24689059 DOI: 10.1155/2014/831989
    The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue.
    Matched MeSH terms: Time Factors
  3. Bong LJ, Neoh KB, Jaal Z, Lee CY
    J. Econ. Entomol., 2013 Dec;106(6):2530-40.
    PMID: 24498755
    The contact toxicity of four insecticide formulations (deltamethrin, fipronil, fenitrothion, and imidacloprid) applied on three different substrates (tile, plywood, and concrete) against the adult rove beetle, Paederus fuscipes Curtis, was evaluated. The relative order of speed of killing effects was as follows: deltamethrin > imidacloprid > fipronil > fenitrothion. Although deltamethrin showed the fastest action against P. fuscipes, the recovery rate of rove beetles at 48 h posttreatment was moderate (approximately 25%) on the tile surface to high (approximately 80%) on the plywood surface. Thus, it is likely that the insects did not pick up the lethal dose especially on porous surfaces. In contrast, fipronil demonstrated delayed toxicity that might promote maximal uptake by the insects. More than 80% mortality was registered for tile and plywood surfaces up to 4 wk after exposure. High mortality (almost 100%) was recorded for imidacloprid-exposed P. fuscipes at 48 h posttreatment, but only on the tile surface. Among the four insecticides tested, fenitrothion was the least effective against P. fuscipes because low percentage to no mortality was recorded in the fenitrothion treatment.
    Matched MeSH terms: Time Factors
  4. Al-lela OQ, Elkalmi RM, Jamshed SQ
    Am J Pharm Educ, 2013 Jun 12;77(5):106.
    PMID: 23788817 DOI: 10.5688/ajpe775106
    Matched MeSH terms: Time Factors
  5. Mahre MB, Wahid H, Rosnina Y, Jesse FF, Azlan CA, Yap KC
    Anim. Reprod. Sci., 2013 Oct;141(3-4):148-53.
    PMID: 24012278 DOI: 10.1016/j.anireprosci.2013.07.012
    A study was conducted to profile the plasma progesterone (P4) concentrations and establish the length of oestrous cycle in the Rusa timorensis during the breeding season. Five healthy hinds were selected for peripheral blood sampling twice weekly to gauge the P4 levels by radioimmunoassay, at the start of the breeding season indicated by rutting behaviours of sexually active males. The hinds were polyestrous as proven by the cyclic trend of P4 levels. After the presumptive oestrus indicated by the lowest P4 concentrations (0.20±0.09ng/ml), this ovarian hormone was markedly elevated on day 7 of the cycle (0.78±0.20ng/ml), reached its peak (2.61±0.23ng/ml, P<0.05) on day 14, and then declined to the basal level in the subsequent oestrus. The mean oestrous cycle length in R. timorensis during the breeding season was 19.2 days with a range of 18-21 days, and the pattern of circulating progesterone during the oestrous cycle of the R. timorensis is similar to those of other deer species. It was also observed that the length of oestrous cycle of R. timorensis determined by gauging the progesterone levels and observation of the oestrous behaviours as well as changes in the cellular pattern of vaginal epithelial cells are highly consistent.
    Matched MeSH terms: Time Factors
  6. Harano K, Harano T
    Rinsho Byori, 2013 Mar;61(3):217-23.
    PMID: 23785790
    This study was done to detect and diagnose beta-thalassemia (beta-Thal) gene quickly. We applied sequence specific Amplification (SSA) method to the analysis. 13 kinds of beta-Thal and two kinds of hemoglobin variants were able to detect under the same PCR condition. These mutations were found frequently in ten countries of Asian region (the southern part of China, Vietnam, Cambodia, Thailand, Myanmar, Malaysia, Singapore, Indonesia, Pakistan, India), and 15 kinds in total (-28CapA-->G, CD5-CT, CD8/9+-G, CD15G-->A, CD17A-->T, IVSI-1G-->T, CD41/42-4del, CD16-C, CD26G-->A(betaE), IVSI-5G-->C, CD35C-->A, CD71/72 +A, CD6A-->T (betaS), -619del, IVSII-654C-->T). More than 80% of patients are included in these mutations. To make the reagents a kit, the procedure became simple and rapid. DNA was extracted by salting out method. The PCR product was detected by polyacrylamide gel electrophoresis and silver staining. The confirmation of the variant was done by the PCR-direct sequencing method. It took approximately six hours for PCR reaction, electrophoresis and staining. This method made us to detect and diagnose beta-Thal in one day.
    Matched MeSH terms: Time Factors
  7. Abu Hanifah R, Mohamed MN, Jaafar Z, Mohsein NA, Jalaludin MY, Majid HA, et al.
    PLoS ONE, 2013;8(12):e82893.
    PMID: 24349388 DOI: 10.1371/journal.pone.0082893
    BACKGROUND: In adults, heart rate recovery is a predictor of mortality, while in adolescents it is associated with cardio-metabolic risk factors. The aim of this study was to examine the relationship between body composition measures and heart rate recovery (HRR) after step test in Malaysian secondary school students.

    METHODS: In the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study, 1071 healthy secondary school students, aged 13 years old, participated in the step test. Parameters for body composition measures were body mass index z-score, body fat percentage, waist circumference, and waist height ratio. The step test was conducted by using a modified Harvard step test. Heart rate recovery of 1 minute (HRR1min) and heart rate recovery of 2 minutes (HRR2min) were calculated by the difference between the peak pulse rate during exercise and the resting pulse rate at 1 and 2 minutes, respectively. Analysis was done separately based on gender. Pearson correlation analysis was used to determine the association between the HRR parameters with body composition measures, while multiple regression analysis was used to determine which body composition measures was the strongest predictor for HRR.

    RESULTS: For both gender groups, all body composition measures were inversely correlated with HRR1min. In girls, all body composition measures were inversely correlated with HRR2min, while in boys all body composition measures, except BMI z-score, were associated with HRR2min. In multiple regression, only waist circumference was inversely associated with HRR2min (p=0.024) in boys, while in girls it was body fat percentage for HRR2min (p=0.008).

    CONCLUSION: There was an inverse association between body composition measurements and HRR among apparently healthy adolescents. Therefore, it is important to identify cardio-metabolic risk factors in adolescent as an early prevention of consequent adulthood morbidity. This reiterates the importance of healthy living which should start from young.

    Matched MeSH terms: Time Factors
  8. Aldhubhani AH, lzham MI, Pazilah I, Anaam MS
    East. Mediterr. Health J., 2013 Oct;19(10):837-42.
    PMID: 24313146
    Few studies have explored diagnosis delay by tuberculosis (TB) patients and its effects on the rate of infection among their close contacts. A cross-sectional study of the close contacts of 505 newly diagnosed TB patients was conducted in a TB referral centre in Sana'a, Yemen from 2008 to 2010. Only the close contacts of 89 new TB patients agreed to participate and completed the tuberculin skin test (TST). Of the 239 close contacts investigated, 133 (55.6%) had a positive TST result. Index patients were classified as long or short diagnosis delay (above or below the median). There was no significant difference in the number of infected close contacts between long and short delay index patients (Mann-Whitney U-test). A larger sample size, with more incentives for patients to participate and the use of other investigative tools could provide a better picture of the pattern of TB transmission among all contacts.
    Matched MeSH terms: Time Factors
  9. Anouar el H, Weber JF
    PMID: 23880409 DOI: 10.1016/j.saa.2013.06.114
    Natural styrylpyrones isolated from fungi are known for various biological activities including antioxidant activity by scavenging free radicals. UV/vis spectra play an important role in elucidating chemical structures of these compounds via identification of chromophore units. With the aim of predicting the UV/vis spectra of a series of natural styrylpyrones, we tested TD-DFT, CIS and ZINDO methods in gas and in PCM solvent. The results showed that the individual or combined B3P86 and B3LYP hybrid functionals are suitable to predict the maximum wavelength absorption bands (λmax) for styrylpyrones. The structure property relationship (SPR) study emphasized the role of (i) structural parameters (e.g., hydrogen bond and the length of conjugated double bonds) and (ii) electronic descriptors (e.g., ionization potential, electronic affinity, hardness and electrophilicity) in bathochromic and hypsochromic shifts of maximum wavelength absorption bands (λmax) of styrylpyrone derivatives.
    Matched MeSH terms: Time Factors
  10. Leong WS, Liong ML, Liong YV, Wu DB, Lee SW
    Urology, 2014 Jan;83(1):40-4.
    PMID: 24044912 DOI: 10.1016/j.urology.2013.08.004
    To determine the efficacy of a combination of simultaneous shock wave lithotripsy (SWL), hydration with controlled inversion therapy compared with SWL with hydration alone in patients with lower pole calyx stones.
    Matched MeSH terms: Time Factors
  11. Talei D, Valdiani A, Maziah M, Mohsenkhah M
    ScientificWorldJournal, 2013;2013:408026.
    PMID: 24307869 DOI: 10.1155/2013/408026
    Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450 MHz of microwave frequency for one, four, seven, and ten hours. It was revealed that exposing the seeds to the microwave frequency for 10 hours resulted in the highest GP. This treatment led to 100% of germination after three days with a mean germination time of 2.1 days. Although the other exposure times of microwave frequency caused the moderate effects on germination with a GP(a3) ranged from 93% to 98%, they failed to reduce the MGT(a3). The results showed that ten-hour exposure times of microwave frequency for six days significantly facilitated and improved the germination indices (primary shoot and root length). Therefore, the technique is expected to benefit the improvement of rice seed germination considering its simplicity and efficacy in increasing the germination percentage and rate as well as the primary shoot and root length without causing any environmental toxicity.
    Matched MeSH terms: Time Factors
  12. Ng CA, Sun D, Bashir MJ, Wai SH, Wong LY, Nisar H, et al.
    Bioresour. Technol., 2013 Jun;138:38-47.
    PMID: 23612160 DOI: 10.1016/j.biortech.2013.03.129
    It was found that with replenishment, powdered activated carbon (PAC) in the membrane bioreactor (MBR) would develop biologically activated carbon (BAC) which could enhance filtration performance of a conventional MBR. This paper addresses two issues (i) effect of PAC size on MBR (BAC) performance; and (ii) effect of sludge retention time (SRT) on the MBR performance with and without PAC. To interpret the trends, particle/floc size, concentration of mixed liquor suspended solid (MLSS), total organic carbon (TOC), short-term filtration properties and transmembrane pressure (TMP) versus time are measured. The results showed improved fouling control with fine, rather than coarse, PAC provided the flux did not exceed the deposition flux for the fine PAC. Without PAC, the longer SRT operation gave lower fouling at modest fluxes. With PAC addition, the shorter SRT gave better fouling control, possibly due to greater replenishment of the fresh PAC.
    Matched MeSH terms: Time Factors
  13. Banerjee S, Theesar SJ, Kurths J
    Chaos, 2013 Mar;23(1):013118.
    PMID: 23556955 DOI: 10.1063/1.4791589
    We study generalized variable projective synchronization between two unified time delayed systems with constant and modulated time delays. A novel Krasovskii-Lyapunov functional is constructed and a generalized sufficient condition for synchronization is derived analytically using the Lyapunov stability theory and adaptive techniques. The proposed scheme is valid for a system of n-numbers of first order delay differential equations. Finally, a new neural oscillator is considered as a numerical example to show the effectiveness of the proposed scheme.
    Matched MeSH terms: Time Factors
  14. Mohamad Ali MS, Mohd Fuzi SF, Ganasen M, Abdul Rahman RN, Basri M, Salleh AB
    Biomed Res Int, 2013;2013:925373.
    PMID: 23738333 DOI: 10.1155/2013/925373
    The psychrophilic enzyme is an interesting subject to study due to its special ability to adapt to extreme temperatures, unlike typical enzymes. Utilizing computer-aided software, the predicted structure and function of the enzyme lipase AMS8 (LipAMS8) (isolated from the psychrophilic Pseudomonas sp., obtained from the Antarctic soil) are studied. The enzyme shows significant sequence similarities with lipases from Pseudomonas sp. MIS38 and Serratia marcescens. These similarities aid in the prediction of the 3D molecular structure of the enzyme. In this study, 12 ns MD simulation is performed at different temperatures for structural flexibility and stability analysis. The results show that the enzyme is most stable at 0°C and 5°C. In terms of stability and flexibility, the catalytic domain (N-terminus) maintained its stability more than the noncatalytic domain (C-terminus), but the non-catalytic domain showed higher flexibility than the catalytic domain. The analysis of the structure and function of LipAMS8 provides new insights into the structural adaptation of this protein at low temperatures. The information obtained could be a useful tool for low temperature industrial applications and molecular engineering purposes, in the near future.
    Matched MeSH terms: Time Factors
  15. Nurita AT, Hassan AA
    Bull. Entomol. Res., 2013 Jun;103(3):296-302.
    PMID: 23302698 DOI: 10.1017/S0007485312000703
    Two types of municipal solid waste (MSW), newly arrived and 2 weeks old, were sampled from a sanitary landfill in Pulau Pinang, Malaysia at a fortnightly interval and kept under field conditions for 2 weeks. A total of 480 kg of each type of MSW was sampled to study species composition and impact of delays in cover soil applications on filth fly emergence. Out of 960 kg of MSW sampled, 9.2 ± 0.5 flies emerged per kilogram. Weekly adult fly emergence rates of newly arrived and 2-week-old waste did not differ significantly and MSW remained suitable for fly breeding for up to 1 month. Eight species of flies emerged from the MSW: namely, Musca domestica, Musca sorbens, Synthesiomyia nudiseta, Hydrotaea chalcogaster, Chrysomya megacephala, Lucilia cuprina, Hemipyrellia ligurriens and Sarcophaga sp. Newly arrived waste was determined to be the main source for M. domestica, C. megacephala and L. cuprina in the landfill owing to significantly higher mean emergence compared with 2-week-old waste. Musca sorbens was found in newly arrived waste but not in 2-week-old waste, suggesting that the species was able to survive transportation to landfill but unable to survive landfill conditions. Hemipyrellia ligurriens, H. chalcogaster and S. nudiseta were not imported into the landfill with MSW and pre-existing flies in and around the landfill itself may be their source. The results show that landfills can be a major source of fly breeding if cover soil or temporary cover is not applied daily or on a regular schedule.
    Matched MeSH terms: Time Factors
  16. Jalal KC, Faizul HN, Naim MA, John BA, Kamaruzzaman BY
    J Environ Biol, 2012 Jul;33(4):831-5.
    PMID: 23360015
    A study on physico-chemical parameters and pathogenic bacterial community was carried out at the coastal waters of Pulau Tuba island, Langkawi. The physico-chemical parameters such as temperature (27.43-28.88 degrees C), dissolved oxygen (3.79-6.49 mg l(-1)), pH (7.72-8.20), salinity (33.10-33.96 ppt), total dissolved solids (32.27-32.77 g l(-1)) and specific conductivity (49.83-51.63 mS cm(-1)) were observed. Station 3 and station 4 showed highest amount of nitrates (26.93 and 14.61 microg at N l(-1)) than station 1 (2.04 microg at N l(-1)) and station 2 (4.18 microg at N l(-1)). The highest concentration (12.4 +/- microg l(-1)) of chlorophyll a was observed in station 4 in October 2005. High phosphorus content (561 microg P l(-1)) was found in the station 2. Thirteen bacterial isolates were successfully identified using API 20E system. The highest amount of bacteria was observed at Station 4 (3400 CFU ml(-1)) and the lowest numberwas at Station 2 (890 CFU ml(-1)). Out of identified 13 Gram-negative bacterial isolates dominant species were Aeromonas hydrophila, Klebsiella oxytoca, Pseudomonas baumannii, Vibrio vulnificus, Proteus mirabilis, Providencia alcalifaciens and Serratia liquefaciens. Apart from this, oil biodegrading Pseudomonas putida were also identified. The study reveals the existing status of water quality is still conducive and the reasonably diverse with Gram-negative bacteria along the Pulau Tuba Langkawi.
    Matched MeSH terms: Time Factors
  17. Chan BT, Lim E, Ong CW, Abu Osman NA
    PMID: 23521137 DOI: 10.1080/10255842.2013.779683
    Despite the advancement of cardiac imaging technologies, these have traditionally been limited to global geometrical measurements. Computational fluid dynamics (CFD) has emerged as a reliable tool that provides flow field information and other variables essential for the assessment of the cardiac function. Extensive studies have shown that vortex formation and propagation during the filling phase acts as a promising indicator for the diagnosis of the cardiac health condition. Proper setting of the boundary conditions is crucial in a CFD study as they are important determinants, that affect the simulation results. In this article, the effect of different transmitral velocity profiles (parabolic and uniform profile) on the vortex formation patterns during diastole was studied in a ventricle with dilated cardiomyopathy (DCM). The resulting vortex evolution pattern using the uniform inlet velocity profile agreed with that reported in the literature, which revealed an increase in thrombus risk in a ventricle with DCM. However the application of a parabolic velocity profile at the inlet yields a deviated vortical flow pattern and overestimates the propagation velocity of the vortex ring towards the apex of the ventricle. This study highlighted that uniform inlet velocity profile should be applied in the study of the filling dynamics in a left ventricle because it produces results closer to that observed experimentally.
    Matched MeSH terms: Time Factors
  18. Sreeramareddy CT, Majeed Kutty NA, Razzaq Jabbar MA, Boo NY
    Biosci Trends, 2012 Jun;6(3):103-9.
    PMID: 22890157 DOI: 10.5582/bst.2012.v6.3.103
    The burden of non-communicable diseases is increasing in Malaysia. Insufficient Physical Activity, which is an important risk factor for non-communicable diseases, is less researched in Malaysia. We aimed to assess the level of physical activity and identify its correlates. An online survey was carried out during October, 2011 in the University Tunku Abdul Rahman by the opinion poll research committee. Young adults answered the Short International Physical Activity Questionnaire and a questionnaire about factors according to a socio-ecological model which was adapted from published studies. Metabolic equivalent (MET)-hours and MET-minutes were calculated. Physical activity was classified as sufficient when MET-minutes were > 840. The mean age of the 474 participants was 22.4 years (S.D. = 4.7), and 253 (53.4%) were females. Their mean and median of MET-hours of PA done during the previous seven days were 31.36 (S.D., 52.19) and 14.7 (IQR, 5.77-32.07), respectively. Physical activity done was sufficient among 242 (51.1%) participants. Using univariate analysis, being male, good self-rated health, positive intention, self-efficacy, perceived benefits, social support, and availability of facilities were associated with sufficient physical activity. Using multivariate analysis sufficient physical activity was associated with participants' intention (OR 0.75, 95% CIs 0.64, 0.88), self-efficacy (OR 0.91, 95% CIs 0.85, 0.97) and facility availability (OR 0.81, 95% CIs 0.73, 0.91). The proportion of participants with sufficient physical activity was low. Positive intention and self-efficacy associated with sufficient physical activity should be supported by availability of facilities and a safely-built environment. A nationwide survey about physical and associated socialecological factors is needed to design rational health promotion strategies.
    Matched MeSH terms: Time Factors
  19. Ahmed MJ, Theydan SK
    Ecotoxicol. Environ. Saf., 2012 Oct;84:39-45.
    PMID: 22795888 DOI: 10.1016/j.ecoenv.2012.06.019
    Adsorption capacity of an agricultural waste, palm-tree fruit stones (date stones), for phenolic compounds such as phenol (Ph) and p-nitro phenol (PNPh) at different temperatures was investigated. The characteristics of such waste biomass were determined and found to have a surface area and iodine number of 495.71 m2/g and 475.88 mg/g, respectively. The effects of pH (2-12), adsorbent dose (0.6-0.8 g/L) and contact time (0-150 min) on the adsorptive removal process were studied. Maximum removal percentages of 89.95% and 92.11% were achieved for Ph and PNPh, respectively. Experimental equilibrium data for adsorption of both components were analyzed by the Langmuir, Freundlich and Tempkin isotherm models. The results show that the best fit was achieved with the Langmuir isotherm equation with maximum adsorption capacities of 132.37 and 161.44 mg/g for Ph and PNPh, respectively. The kinetic data were fitted to pseudo-first order, pseudo-second order and intraparticle diffusion models, and was found to follow closely the pseudo-second order model for both components. The calculated thermodynamic parameters, namely ΔG, ΔH, and ΔS showed that adsorption of Ph and PNPh was spontaneous and endothermic under examined conditions.
    Matched MeSH terms: Time Factors
  20. Mahdin H, Abawajy J
    Sensors (Basel), 2011;11(10):9863-77.
    PMID: 22163730 DOI: 10.3390/s111009863
    Radio frequency identification (RFID) systems are emerging as the primary object identification mechanism, especially in supply chain management. However, RFID naturally generates a large amount of duplicate readings. Removing these duplicates from the RFID data stream is paramount as it does not contribute new information to the system and wastes system resources. Existing approaches to deal with this problem cannot fulfill the real time demands to process the massive RFID data stream. We propose a data filtering approach that efficiently detects and removes duplicate readings from RFID data streams. Experimental results show that the proposed approach offers a significant improvement as compared to the existing approaches.
    Matched MeSH terms: Time Factors
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