42 research outputs found
Clustering Approach to Quantify Long-Term Spatio-Temporal Interactions in Epileptic Intracranial Electroencephalography
Abnormal dynamical coupling between brain structures is believed to be primarily
responsible for the generation of epileptic seizures and their propagation. In this study, we
attempt to identify the spatio-temporal interactions of an epileptic brain using a previously
proposed nonlinear dependency measure. Using a clustering model, we determine the average
spatial mappings in an epileptic brain at different stages of a complex partial seizure. Results
involving 8 seizures from 2 epileptic patients suggest that there may be a fixed pattern associated
with regional spatio-temporal dynamics during the interictal to pre-post-ictal transition
Location and Level of Etk Expression in Neurons Are Associated with Varied Severity of Traumatic Brain Injury
Much recent research effort in traumatic brain injury (TBI) has been devoted to the discovery of a reliable biomarker correlating with severity of injury. Currently, no consensus has been reached regarding a representative marker for traumatic brain injury. In this study, we explored the potential of epithelial/endothelial tyrosine kinase (Etk) as a novel marker for TBI.TBI was induced in Sprague Dawley (SD) rats by controlled cortical impact. Brain tissue samples were analyzed by Western blot, Q-PCR, and immunofluorescence staining using various markers including glial fibrillary acidic protein, and epithelial/endothelial tyrosine kinase (Etk). Results show increased Etk expression with increased number and severity of impacts. Expression increased 2.36 to 7-fold relative to trauma severity. Significant upregulation of Etk appeared at 1 hour after injury. The expression level of Etk was inversely correlated with distance from injury site. Etk and trauma/inflammation related markers increased post-TBI, while other tyrosine kinases did not.The observed correlation between Etk level and the number of impacts, the severity of impact, and the time course after impact, as well as its inverse correlation with distance away from injury site, support the potential of Etk as a possible indicator of trauma severity
Smoking, Green Tea Consumption, Genetic Polymorphisms in the Insulin-Like Growth Factors and Lung Cancer Risk
Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR) = 13.16, 95% confidence interval (CI) = 2.96–58.51). Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA)19/(CA)19 and (CA)19/X genotypes carriers had a significantly reduced risk of lung cancer (OR = 0.06, 95% CI = 0.01–0.44) compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment
Determinants of consumers’ intentions to share knowledge and intentions to purchase on s-commerce sites: incorporating attitudes toward persuasion attempts into a social exchange model
This research explores s-commerce users’ intentions to purchase and to share knowledge by incorporating ‘attitudes toward persuasion attempts,’ ‘ease of use,’ and ‘perceived usefulness’ into a social exchange theory model. A survey using an on-site purposive sampling technique was used to recruit the respondents, and an interception technique was used to approach the consumers. A total of 471 Korean consumers participated in this research. Based on 471 Korean social-commerce users, our results reveal that social exchange belief factors and a site’s usability affect user satisfaction, which subsequently affects users’ intentions to purchase and to share knowledge. In addition, attitudes toward persuasion attempts moderate the effect of satisfaction on users’ purchase intentions.
Keywords: social exchange theory, attitudes toward persuasion attempts, intention to share knowledge, social exchange belief
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Utilization of diets with hydrolyzed potato starch, or glucose by juvenile white sturgeon (Acipenser transmontanus), as affected by Maillard reaction during feed processing
An 8-week growth trial was conducted to study carbohydrate utilization by white sturgeon fed diets containing glucose or hydrolyzed potato starch (HPS). Four diets supplemented with 15% or 30% of glucose or HPS and a control diet with no added carbohydrate were each fed to triplicate groups of fish. The diets were processed by a 3-min 80 degrees C microwave moist heating, followed by 1-h 70 degrees C drying. Feeding rates varied from 1.7% to 3.2% body weight day(-1) so that all treatment groups were fed the same amount of dietary protein and lipid. The HPS groups showed the highest (P<0.05) specific growth rate, followed by the control, and then by the glucose groups. Feed efficiency was highest in the control and 15% HPS group followed by the 30% HPS group, and lowest in the glucose groups. Protein and energy retentions, whole body lipid, and muscle glycogen showed a similar pattern; with the glucose groups significantly lower than the control and HPS groups, whereas there was no difference among the control and HPS groups. A lower lysine and glucose in the glucose than control diets suggested that a severe Maillard reaction had occurred in the moist heat process, drying, and storage of the glucose diets. This is supported by the significantly lower plasma lysine concentrations in sturgeon fed the glucose diets than those fed the control diet. Sturgeon fed the glucose diets also showed significantly lower concentrations of plasma protein, cysteine, and hydroxyproline than those fed the control diet, whereas concentrations of liver glycogen and plasma alanine, gamma-aminobutyric acid and proline were significantly higher in sturgeon fed the glucose than the control and HPS diets. In conclusion, growth performances of sturgeon were not adversely affected by 15% HPS in the diet but severe Maillard reaction in the glucose diets resulted in significant reduction in the growth performances of the fish. (C) 2005 Elsevier B.V. All rights reserved
AFOMP Policy Statement No. 4: Recommendations for continuing professional development systems for medical physicists in AFOMP countries
This policy statement, which is the fourth of a series of documents being prepared by the Asia-Oceania Federation of Organizations for Medical Physics Committees Professional Development Committee, gives guidance on how member countries could develop a continuing professional development system for ensuring that its clinical medical physicists are up-to-date in their knowledge and practice. It is not intended to be prescriptive as there are already several CPD systems successfully operated by AFOMP member countries and elsewhere that vary considerably in scope and structure according to local culture, practice and legislation but all of which are capable of ensuring that physicists are up-to-date. It is intended to be advisory and set out options for member countries to develop their individual CPD systems
AFOMP Policy Statement No. 3: recommendations for the education and training of medical physicists in AFOMP countries
AFOMP recognizes that clinical medical physicists should demonstrate that they are competent to practice their profession by obtaining appropriate education, training and supervised experience in the specialties of medical physics in which they practice, as well as having a basic knowledge of other specialties. To help its member countries to achieve this, AFOMP has developed this policy to provide guidance when developing medical physicist education and training programs. The policy is compatible with the standards being promoted by the International Organization for Medical Physics and the International Medical Physics Certification Board