297 research outputs found
Ladder Structure Triangular Micro Channels for Low Power and high Performance Micro Channel Cooling System
Heat dissipation from micro devices is now becoming a critical field since the performance of the IC is mostly determined by temperature fields. The success of an IC cooling system or heat sink for ULSI depends on the ability to achieve effective heat transfer rate to the ?owing liquid and superior ?ow performance of the micro channels. Various studies on micro channel cooling systems (MCCS) in the past have focused on improving the flow characteristics of parallel rectangular micro channels. The present investigator aimed at improving the contact area in addition to achieving high convective heat transfer coefficient, thus introduced andreported ladder structure micro channel cooling systems (LSMCCS). The present study focuses on further improving the LSMCCS design so that high performance device cooling at low pumping power is achieved. First the various cross sectional shapes have been studied by keeping the cross sectional area and hydraulic diameter uniform to explore the possibility of further improving the performance of the micro cooling system. Hydraulic and thermal performance of ladder structure micro channels with rectangular, trapezium and triangular cross sectional shapes indicates that triangular shaped ladder structure micro channels would give the minimum pressure drop, the least thermal resistance at the least pumping power. Finally the investigator studied the performance of ladder structure triangular shaped micro channels cooling system with common inlet and outlet to simulate a packaged LSMCCS and the results show that ladder structure triangular shaped MCCS can give the best cooling performance. The temperature profiles that were obtained over the cross section of the inlet and outlet show that the LSMCCS can give excellent thermal resistance when triangular shape channels are employed and therefore can be ideal cooling systems for ULSI
Challenges of small scale entrepreneur's in Sohar Port anyone there to listen?
Investment by its nature looks forward to the highest rate of earnings and which support the development of a country.In order to meet right investment a stable business environment is required.Sohar Industrial Port is one of the major
investment and employment hubs of Oman. The emergence of SMEs in Ports of Oman paves way for higher rate of earnings and attracts lot of Entrepreneurs to set up business in the ports of Oman.As it is claimed, this investment has aimed
at employment opportunities to the growing educated youngsters.Though such developments are going on, there are very less studies focused on the opportunities and challenges of SMEs in the Sohar port.Con temporarily, a study, which focuses
on the challenges of entrepreneurs, that to analyze the development climate in the ports of Sultanate of OMAN, needs to be explored into. This research paper thus extends better insight into Sohar Port as employment and Investment hub
of Oman: the challenges of SMEs and entrepreneurs in the “Sohar port”
Water Oxidation by a Cytochrome P450: Mechanism and Function of the Reaction
P450cam (CYP101A1) is a bacterial monooxygenase that is known to catalyze the oxidation of camphor, the first committed step in camphor degradation, with simultaneous reduction of oxygen (O2). We report that P450cam catalysis is controlled by oxygen levels: at high O2 concentration, P450cam catalyzes the known oxidation reaction, whereas at low O2 concentration the enzyme catalyzes the reduction of camphor to borneol. We confirmed, using 17O and 2H NMR, that the hydrogen atom added to camphor comes from water, which is oxidized to hydrogen peroxide (H2O2). This is the first time a cytochrome P450 has been observed to catalyze oxidation of water to H2O2, a difficult reaction to catalyze due to its high barrier. The reduction of camphor and simultaneous oxidation of water are likely catalyzed by the iron-oxo intermediate of P450cam, and we present a plausible mechanism that accounts for the 1:1 borneol:H2O2 stoichiometry we observed. This reaction has an adaptive value to bacteria that express this camphor catabolism pathway, which requires O2, for two reasons: 1) the borneol and H2O2 mixture generated is toxic to other bacteria and 2) borneol down-regulates the expression of P450cam and its electron transfer partners. Since the reaction described here only occurs under low O2 conditions, the down-regulation only occurs when O2 is scarce
Characterization of METTL16 as a cytoplasmic RNA binding protein
mRNA modification by N6-methyladenosine (m6A) is involved in many post-transcriptional
regulation processes including mRNA stability, splicing and promotion of translation.
Accordingly, the recently identified mRNA methylation complex containing METTL3,
METTL14, and WTAP has been the subject of intense study. However, METTL16
(METT10D) has also been identified as an RNA m6A methyltransferase that can methylate
both coding and noncoding RNAs, but its biological role remains unclear. While global studies have identified many potential RNA targets of METTL16, only a handful, including the
long noncoding RNA MALAT1, the snRNA U6, as well as the mRNA MAT2A have been verified and/or studied to any great extent. In this study we identified/verified METTL16 targets
by immunoprecipitation of both endogenous as well as exogenous FLAG-tagged protein.
Interestingly, exogenously overexpressed METTL16 differed from the endogenous protein
in its relative affinity for RNA targets which prompted us to investigate METTL16’s localization within the cell. Surprisingly, biochemical fractionation revealed that a majority of
METTL16 protein resides in the cytoplasm of a number of cells. Furthermore, siRNA knockdown of METTL16 resulted in expression changes of a few mRNA targets suggesting that
METTL16 may play a role in regulating gene expression. Thus, while METTL16 has been
reported to be a nuclear protein, our findings suggest that METTL16 is also a cytoplasmic
methyltransferase that may alter its RNA binding preferences depending on its cellular localization. Future studies will seek to confirm differences between cytoplasmic and nuclear
RNA targets in addition to exploring the physiological role of METTL16 through long-term
knockdown
Genetic and environmental influences on sleep quality in middle‐aged men: a twin study
Poor sleep quality is a risk factor for a number of cognitive and physiological age-related disorders. Identifying factors underlying sleep quality are important in understanding the etiology of these age-related health disorders. We investigated the extent to which genes and the environment contribute to subjective sleep quality in middle-aged male twins using the classical twin design. We used the Pittsburgh Sleep Quality Index to measure sleep quality in 1218 middle-aged twin men from the Vietnam Era Twin Study of Aging (mean age = 55.4 years; range 51-60; 339 monozygotic twin pairs, 257 dizygotic twin pairs, 26 unpaired twins). The mean PSQI global score was 5.6 [SD = 3.6; range 0-20]. Based on univariate twin models, 34% of variability in the global PSQI score was due to additive genetic effects (heritability) and 66% was attributed to individual-specific environmental factors. Common environment did not contribute to the variability. Similarly, the heritability of poor sleep-a dichotomous measure based on the cut-off of global PSQI>5-was 31%, with no contribution of the common environment. Heritability of six of the seven PSQI component scores (subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, and daytime dysfunction) ranged from 0.15 to 0.31, whereas no genetic influences contributed to the use of sleeping medication. Additive genetic influences contribute to approximately one-third of the variability of global subjective sleep quality. Our results in middle-aged men constitute a first step towards examination of the genetic relationship between sleep and other facets of aging.Accepted manuscrip
Relationship marketing and service quality in Bank Muscat Oman (Sayarati Loans)
Sultanate of Oman is one of the prominent GCC Countries with a population of around 3 million.With assets worth over USD 15 billion, Bank Muscat (SAOG) is the leading financial services provider in Oman with a strong presence in Corporate Banking, Retail Banking, Investment Banking, Treasury, Private Banking and Asset Management. This paper looks into the “RELATIONSHIP MARKETING AND SERVICE QUALITY IN BANK MUSCAT OMAN (Sayaratti Loans)”.The quality of customer service is the key indicator of the performance of the different branches of the Bank.Banks in the current scenario is increasingly showing its interest in satisfying a customer wants.Given the profit figures on board as targets Banks need to also look into the special needs of the customer’s perspective, any lacuna in service quality to be looked into seriously.The car loans popularly known as Sayaratti loans are taken as the product for study.The findings of the study say that there is a significant relationship between the age and the overall customer
satisfaction levels and there is no significant relationship between the age and the service quality by the bank
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Awareness regarding eye donation among stakeholders in Srikakulam district in South India
Background
There is a huge need for the availability of transplantable donor corneas worldwide to reduce the burden of corneal blindness due to corneal opacity. Voluntary eye donation depends on the awareness levels of various stakeholders in the community. This study aimed to assess the awareness level regarding eye donation among various stakeholders in Srikakulam district in the state of Andhra Pradesh, India.
Methods
355 subjects were selected from the district using multi stage random sampling. A pre tested semi structured questionnaire was used to collect information regarding each individual’s awareness, knowledge, and perception regarding eye donation. Each response was scored individually and a total score was calculated. Univariate and multivariate regression analysis was used to determine the factors associated with willingness towards eye donation and increased awareness levels.
Results
Of the 355 subjects interviewed, 192 (54%) were male and 163 (46%) were female. The mean age of the stakeholders was 35.9 years (SD ±16.1) and all the study subjects were literate. Ninety-three percent of subjects were aware of the concept of eye donation. Knowledge levels were similar among the teaching community and persons engaged in social service, but lower among students (p < 0.05). Among the stakeholders, there was considerable ambiguity regarding whether persons currently wearing spectacles or suffering from a chronic illnesses could donate their eyes. Older age group (p < 0.001), female gender (p < 0.001) and education (p < 0.001) were associated with increased knowledge levels. 82% of the subjects were willing to donate their eyes and this was unaffected by gender or geographical location (rural vs urban).
Conclusions
Awareness levels and willingness to donate eyes are high among the stakeholders in Srikakulam district in India. The services of stakeholders could be utilized, in conjunction with other community based eye donation counselors, to promote awareness regarding eye donation among the general population
Reversal of DNA damage induced Topoisomerase 2 DNA–protein crosslinks by Tdp2
Mammalian Tyrosyl-DNA phosphodiesterase 2 (Tdp2) reverses Topoisomerase 2 (Top2) DNA–protein crosslinks triggered by Top2 engagement of DNA damage or poisoning by anticancer drugs. Tdp2 deficiencies are linked to neurological disease and cellular sensitivity to Top2 poisons. Herein, we report X-ray crystal structures of ligand-free Tdp2 and Tdp2-DNA complexes with alkylated and abasic DNA that unveil a dynamic Tdp2 active site lid and deep substrate binding trench well-suited for engaging the diverse DNA damage triggers of abortive Top2 reactions. Modeling of a proposed Tdp2 reaction coordinate, combined with mutagenesis and biochemical studies support a single Mg2+-ion mechanism assisted by a phosphotyrosyl-arginine cation-π interface. We further identify a Tdp2 active site SNP that ablates Tdp2 Mg2+ binding and catalytic activity, impairs Tdp2 mediated NHEJ of tyrosine blocked termini, and renders cells sensitive to the anticancer agent etoposide. Collectively, our results provide a structural mechanism for Tdp2 engagement of heterogeneous DNA damage that causes Top2 poisoning, and indicate that evaluation of Tdp2 status may be an important personalized medicine biomarker informing on individual sensitivities to chemotherapeutic Top2 poisons
Rapid inference of antibiotic resistance and susceptibility by genomic neighbour typing
Genomic neighbour typing can be used to infer the antimicrobial susceptibility and resistance of a bacterial sample based on the genomes of closest relatives. Combined with MinION sequencing, it can rapidly determine microbial resistance for clinical samples within 4 h. Surveillance of drug-resistant bacteria is essential for healthcare providers to deliver effective empirical antibiotic therapy. However, traditional molecular epidemiology does not typically occur on a timescale that could affect patient treatment and outcomes. Here, we present a method called 'genomic neighbour typing' for inferring the phenotype of a bacterial sample by identifying its closest relatives in a database of genomes with metadata. We show that this technique can infer antibiotic susceptibility and resistance for both Streptococcus pneumoniae and Neisseria gonorrhoeae. We implemented this with rapid k-mer matching, which, when used on Oxford Nanopore MinION data, can run in real time. This resulted in the determination of resistance within 10 min (91% sensitivity and 100% specificity for S. pneumoniae and 81% sensitivity and 100% specificity for N. gonorrhoeae from isolates with a representative database) of starting sequencing, and within 4 h of sample collection (75% sensitivity and 100% specificity for S. pneumoniae) for clinical metagenomic sputum samples. This flexible approach has wide application for pathogen surveillance and may be used to greatly accelerate appropriate empirical antibiotic treatment
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