220 research outputs found
Shrimp oil extracted from shrimp processing by-product is a rich source of omega-3 fatty acids and astaxanthin-esters, and reveals potential anti-adipogenic effects in 3T3-L1 adipocytes
The province of Newfoundland and Labrador, Canada, generates tons of shrimp processing by-product every year. Shrimp processing by-product is a valuable source of shrimp oil and astaxanthin (Astx), a potent antioxidant that exist in either free or esterified form (Astx-E). As part of this thesis, extraction of shrimp oil was carried out from shrimp processing by-product using various extraction methods. The shrimp oil extracted from shrimp processing by-product using Soxhlet method (hexane: acetone 2:3) showed that shrimp oil is rich in omega (n)-3 polyunsaturated fatty acids (PUFA), phospholipids and Astx-E. Shrimp oil was also extracted from shrimp processing by-product using waste fish oil as a solvent, and also fish waste. The oil extracts were rich in triacylglycerols (TAG), monounsaturated fatty acids (MUFA), followed by PUFA, and contained low amount of total carotenoids. The next objective of this thesis was to investigate the effects of shrimp extract and shrimp oil on fat accumulation in 3T3-L1 preadipocytes, and the mRNA expression of genes involved in adipogenesis and lipogenesis. I also investigated the effects of fish oil, and a combination of fish oil plus Astx-E on fat accumulation, and the mRNA expression of genes involved in adipogenesis and lipogenesis in 3T3-L1 adipocytes. My findings demonstrated that shrimp oil extracted from shrimp processing by-product using the Soxhlet method decreased fat accumulation, and reduced the mRNA expression of adipogenic and lipogenic genes, compared to untreated cells. However, fish oil and fish oil plus Astx-E increased fat accumulation, and the mRNA expression of adipogenic and lipogenic genes, compared to untreated cells. Thus, shrimp oil and fish oil appear to regulate adipogenesis and lipogenesis via independent pathways. Shrimp oil extracts using waste fish oil revealed similar effects on adipogenesis and lipogenesis as that of fish oil. Overall, my findings demonstrate that shrimp oil extracted from shrimp processing by-product using the Soxhlet
method contains a significant amount of phospholipids, n-3 PUFA and Astx-E, and inhibits fat accumulation in 3T3-L1 cells. Thus, it has the potential to elicit anti-adipogenic effects
Isolation of Two Strong Poly (U) Binding Proteins from Moderate Halophile Halomonas eurihalina and Their Identification as Cold Shock Proteins
Cold shock proteins (Csp) are known to be expressed in response to sudden decrease in temperature. They are thought to be involved in a number of cellular processes viz., RNA chaperone activity, translation, transcription, nucleoid condensation. During our studies on ribosomal protein S1 in moderate halophile Halomonas eurihalina, we observed the presence of two strong poly (U) binding proteins in abundance in cell extracts from cells grown under normal growth conditions. The proteins can be isolated in a single step using Poly (U) cellulose chromatography. The proteins were identified as major cold shock proteins belonging to Csp A family by MALDI-TOF and bioinformatic analysis. Csp 12 kDa was found in both exponential and stationary phases whereas Csp 8 kDa is found only in exponential phase
Groundwater recharge and age-depth profiles of intensively exploited groundwater resources in northwest India
Intensive irrigation in northwest India has led to growing concerns over the sustainability of current and future groundwater abstraction. Environmental tracers and measurements of groundwater residence times can help quantify the renewal processes. Results from 16 paired locations show the interquartile ranges for residence times in shallow alluvial groundwater (8–50 m deep) to be 1–50 years and significantly less than those from deeper groundwater (76–160 m deep) at 40–170 years. The widespread occurrence of modern tracers in deep groundwater (>60% of sites had >10% modern recharge) suggests that there is low regional aquifer anisotropy and that deep aquifers are recharged by a significant component of recent recharge via vertical leakage. Stable isotope and noble gas results at all depths conform to modern meteoric sources and annual average temperatures, with no evidence of significant regional recharge from canal leakage in this study area close to the Himalayas
CspC regulates the expression of the glyoxylate cycle genes at stationary phase in Caulobacter
A Novel Cold-Regulated Cold Shock Domain Containing Protein from Scallop Chlamys farreri with Nucleic Acid-Binding Activity
Background: The cold shock domain (CSD) containing proteins (CSDPs) are one group of the evolutionarily conserved nucleic acid-binding proteins widely distributed in bacteria, plants, animals, and involved in various cellular processes, including adaptation to low temperature, cellular growth, nutrient stress and stationary phase. Methodology: The cDNA of a novel CSDP was cloned from Zhikong scallop Chlamys farreri (designated as CfCSP) by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The full length cDNA of CfCSP was of 1735 bp containing a 927 bp open reading frame which encoded an N-terminal CSD with conserved nucleic acids binding motif and a C-terminal domain with four Arg-Gly-Gly (RGG) repeats. The CSD of CfCSP shared high homology with the CSDs from other CSDPs in vertebrate, invertebrate and bacteria. The mRNA transcripts of CfCSP were mainly detected in the tissue of adductor and also marginally detectable in gill, hepatopancreas, hemocytes, kidney, mantle and gonad of healthy scallop. The relative expression level of CfCSP was up-regulated significantly in adductor and hemocytes at 1 h and 24 h respectively after low temperature treatment (P,0.05). The recombinant CfCSP protein (rCfCSP) could bind ssDNA and in vitro transcribed mRNA, but it could not bind dsDNA. BX04, a cold sensitive Escherichia coli CSP quadruple-deletion mutant, was used to examine the cold adaptation ability of CfCSP. After incubation at 17uC for 120 h, the strain of BX04 containing the vector pINIII showed growth defect and failed to form colonies, while strain containing pINIII-CSPA or pINIII
Development and evaluation of performance characteristics of timolol-loaded composite ocular films as potential delivery platform for treatment of glaucoma
Thin and erodible polymeric films were developed as potential ocular drug delivery systems to increase drug retention on the eye with the aim of improving bioavailability and achieving controlled drug release. Two biocompatible film forming polymers, hyaluronic acid (HA) and hydroxypropyl methylcellulose (HPMC), which are currently used as thickening agents in eye drops were employed. Two different films were prepared (i) as single polymer and (ii) as composite formulations by solvent casting method, incorporating glycerol (GLY) as plasticizer and timolol maleate (TM) as model glaucoma drug. After preliminary optimization of transparency and ease of handling, the formulations were further characterized for their physicochemical properties. No indication of significant drug-polymer or polymer-polymer (in composite films) interaction was observed from FTIR results while evaluation by IR mapping revealed uniform distribution of drug throughout the films. Amorphization of TM in the film matrix was confirmed by both DSC and XRD. Swelling studies illustrated remarkable swelling capacity of HA in comparison with HPMC which directly affected the drug release profiles, making HA a suitable polymer for controlled ocular drug delivery. Tensile and mucoadhesion properties confirmed higher elasticity and adhesiveness of HA while HPMC produced stronger films. The effect of sterilization by UV radiation on mechanical properties was also evaluated and showed no significant difference between the sterilized and non-sterilized films. The SEM results confirmed smoothness and homogeneity of film surfaces for all the formulations studied. The in vitro drug dissolution studies showed more extended release profiles of formulations containing HA. Cytotoxicity study (cell viability) using MTT assay on HeLa cells, confirmed that the single polymer and composite films are generally safe for ocular administration. The present work shows excellent film forming ability of HA and HPMC which can be used as single polymer or combined in composite formulations as potential topical ocular drug delivery platform to enhance drug retention on the ocular surface and therefore potential improved bioavailability
WriteSim TCExam - An open source text simulation environment for training novice researchers in scientific writing
BACKGROUND: The ability to write clearly and effectively is of central importance to the scientific enterprise. Encouraged by the success of simulation environments in other biomedical sciences, we developed WriteSim TCExam, an open-source, Web-based, textual simulation environment for teaching effective writing techniques to novice researchers. We shortlisted and modified an existing open source application - TCExam to serve as a textual simulation environment. After testing usability internally in our team, we conducted formal field usability studies with novice researchers. These were followed by formal surveys with researchers fitting the role of administrators and users (novice researchers) RESULTS: The development process was guided by feedback from usability tests within our research team. Online surveys and formal studies, involving members of the Research on Research group and selected novice researchers, show that the application is user-friendly. Additionally it has been used to train 25 novice researchers in scientific writing to date and has generated encouraging results. CONCLUSION: WriteSim TCExam is the first Web-based, open-source textual simulation environment designed to complement traditional scientific writing instruction. While initial reviews by students and educators have been positive, a formal study is needed to measure its benefits in comparison to standard instructional methods
Scientific writing: a randomized controlled trial comparing standard and on-line instruction
<p>Abstract</p> <p>Background</p> <p>Writing plays a central role in the communication of scientific ideas and is therefore a key aspect in researcher education, ultimately determining the success and long-term sustainability of their careers. Despite the growing popularity of e-learning, we are not aware of any existing study comparing on-line vs. traditional classroom-based methods for teaching scientific writing.</p> <p>Methods</p> <p>Forty eight participants from a medical, nursing and physiotherapy background from US and Brazil were randomly assigned to two groups (n = 24 per group): An on-line writing workshop group (on-line group), in which participants used virtual communication, google docs and standard writing templates, and a standard writing guidance training (standard group) where participants received standard instruction without the aid of virtual communication and writing templates. Two outcomes, manuscript quality was assessed using the scores obtained in Six subgroup analysis scale as the primary outcome measure, and satisfaction scores with Likert scale were evaluated. To control for observer variability, inter-observer reliability was assessed using Fleiss's kappa. A post-hoc analysis comparing rates of communication between mentors and participants was performed. Nonparametric tests were used to assess intervention efficacy.</p> <p>Results</p> <p>Excellent inter-observer reliability among three reviewers was found, with an Intraclass Correlation Coefficient (ICC) agreement = 0.931882 and ICC consistency = 0.932485. On-line group had better overall manuscript quality (p = 0.0017, SSQSavg score 75.3 ± 14.21, ranging from 37 to 94) compared to the standard group (47.27 ± 14.64, ranging from 20 to 72). Participant satisfaction was higher in the on-line group (4.3 ± 0.73) compared to the standard group (3.09 ± 1.11) (p = 0.001). The standard group also had fewer communication events compared to the on-line group (0.91 ± 0.81 vs. 2.05 ± 1.23; p = 0.0219).</p> <p>Conclusion</p> <p>Our protocol for on-line scientific writing instruction is better than standard face-to-face instruction in terms of writing quality and student satisfaction. Future studies should evaluate the protocol efficacy in larger longitudinal cohorts involving participants from different languages.</p
Selection Mechanisms Underlying High Impact Biomedical Research - A Qualitative Analysis and Causal Model
BACKGROUND: Although scientific innovation has been a long-standing topic of interest for historians, philosophers and cognitive scientists, few studies in biomedical research have examined from researchers' perspectives how high impact publications are developed and why they are consistently produced by a small group of researchers. Our objective was therefore to interview a group of researchers with a track record of high impact publications to explore what mechanism they believe contribute to the generation of high impact publications. METHODOLOGY/PRINCIPAL FINDINGS: Researchers were located in universities all over the globe and interviews were conducted by phone. All interviews were transcribed using standard qualitative methods. A Grounded Theory approach was used to code each transcript, later aggregating concept and categories into overarching explanation model. The model was then translated into a System Dynamics mathematical model to represent its structure and behavior. Five emerging themes were found in our study. First, researchers used heuristics or rules of thumb that came naturally to them. Second, these heuristics were reinforced by positive feedback from their peers and mentors. Third, good communication skills allowed researchers to provide feedback to their peers, thus closing a positive feedback loop. Fourth, researchers exhibited a number of psychological attributes such as curiosity or open-mindedness that constantly motivated them, even when faced with discouraging situations. Fifth, the system is dominated by randomness and serendipity and is far from a linear and predictable environment. Some researchers, however, took advantage of this randomness by incorporating mechanisms that would allow them to benefit from random findings. The aggregation of these themes into a policy model represented the overall expected behavior of publications and their impact achieved by high impact researchers. CONCLUSIONS: The proposed selection mechanism provides insights that can be translated into research coaching programs as well as research policy models to optimize the introduction of high impact research at a broad scale among institutional and governmental agencies
So Different, yet So Similar: Meta-Analysis and Policy Modeling of Willingness to Participate in Clinical Trials among Brazilians and Indians
BACKGROUND: With the global expansion of clinical trials and the expectations of the rise of the emerging economies known as BRICs (Brazil, Russia, India and China), the understanding of factors that affect the willingness to participate in clinical trials of patients from those countries assumes a central role in the future of health research. METHODS: We conducted a systematic review and meta-analysis (SRMA) of willingness to participate in clinical trials among Brazilian patients and then we compared it with Indian patients (with results of another SRMA previously conducted by our group) through a system dynamics model. RESULTS: Five studies were included in the SRMA of Brazilian patients. Our main findings are 1) the major motivation for Brazilian patients to participate in clinical trials is altruism, 2) monetary reimbursement is the least important factor motivating Brazilian patients, 3) the major barrier for Brazilian patients to not participate in clinical trials is the fear of side effects, and 4) Brazilian patients are more likely willing to participate in clinical trials than Indians. CONCLUSION: Our study provides important insights for investigators and sponsors for planning trials in Brazil (and India) in the future. Ignoring these results may lead to unnecessary fund/time spending. More studies are needed to validate our results and for better understanding of this poorly studied theme
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