The role of learning and growth hormone-releasing factor in the control of protein intake in rats /

Both learning and basic biological mechanisms have been shown to play a role in the control of protein int^e. It has previously been shown that rats can adapt their dietary selection patterns successfully in the face of changing macronutrient requirements and availability. In particular, it has been demonstrated that when access to dietary protein is restricted for a period of time, rats selectively increase their consumption of a proteincontaining diet when it becomes available. Furthermore, it has been shown that animals are able to associate various orosensory cues with a food's nutrient content. In addition to the role that learning plays in food intake, there are also various biological mechanisms that have been shown to be involved in the control of feeding behaviour. Numerous studies have documented that various hormones and neurotransmitter substances mediate food intake. One such hormone is growth hormone-releasing factor (GRF), a peptide that induces the release of growth hormone (GH) from the anterior pituitary gland. Recent research by Vaccarino and Dickson ( 1 994) suggests that GRF may stimulate food intake by acting as a neurotransmitter in the suprachiasmatic nucleus (SCN) and the adjacent medial preoptic area (MPOA). In particular, when GRF is injected directly into the SCN/MPOA, it has been shown to selectively enhance the intake of protein in both fooddeprived and sated rats. Thus, GRF may play a role in activating protein consumption generally, and when animals have a need for protein, GRF may serve to trigger proteinseeking behaviour. Although researchers have separately examined the role of learning and the central mechanisms involved in the control of protein selection, no one has yet attempted to bring together these two lines of study. Thus, the purpose of this study is to join these two parallel lines of research in order to further our understanding of mechanisms controlling protein selection. In order to ascertain the combined effects that GRF and learning have on protein intake several hypothesis were examined. One major hypothesis was that rats would successfully alter their dietary selection patterns in response to protein restriction. It was speculated that rats kept on a nutritionally complete maintenance diet (NCMD) would consume equal amount of the intermittently presented high protein conditioning diet (HPCD) and protein-free conditioning diet (PFCD). However, it was hypothesized that rats kept on a protein-free maintenance diet (PFMD) would selectively increase their intake of the HPCD. Another hypothesis was that rats would learn to associate a distinct marker flavour with the nutritional content of the diets. If an animal is able to make the association between a marker flavour and the nutrient content of the food, then it is hypothesized that they will consume more of a mixed diet (equal portion HPCD and PFCD) with the marker flavour that was previously paired with the HPCD (Mixednp-f) when kept on the PFMD. In addition, it was hypothesized that intracranial injection of GRF into the SCN/MPOA would result in a selective increase in HPCD as well as Mixednp-t consumption. Results demonstrated that rats did in fact selectively increase their consumption of the flavoured HPCD and Mixednp-f when kept on the NCMD. These findings indicate that the rats successfully learned about the nutrient content of the conditioning diets and were able to associate a distinct marker flavour with the nutrient content of the diets. However, the results failed to support previous findings that GRF increases protein intake. In contrast, the administration of GRF significantly reduced consumption of HPCD during the first hour of testing as compared to the no injection condition. In addition, no differences in the intake of the HPCD were found between the GRF and vehicle condition. Because GRF did not selectively increase HPCD consumption, it was not surprising that GRF also did not increase MixedHP-rintake. What was interesting was that administration of GRF and vehicle did not reduc^Mixednp-f consumption as it had decreased HPCD consumption.

Cognitive coaching : a multiple case study /

The purpose of this qualitative study was to investigate the application of Cognitive Coaching as a school-based professional development program to improve instructional thought and decision making as well as to enhance staff perceptions, coUegiality and school culture. This topic emerged from personal and professional issues related to the role ofthe reflective practitioner in improving the quality of education, yet cognizant of the fact that little professional development was available to train teachers to become reflective. This case study, positioned within the interpretive sciences, focused on three teachers and how their experiences with cognitive coaching affected their teaching practices. Their knowledge, understanding and use of the four stages of instructional thought (preactive, interactive, reflective and projective) were tested before and at the end of eight coaching cycles, and again after two months to determine whether they had continued to use the reflective process. They were also assessed on whether their attitude towards peer coaching had changed, whether their feelings about teaching had become more positive and whether their professional dialogue had increased. Three methods of data collection were selected to assess growth: interviews, observations and joumaling. Analysis primarily consisted of coding and organizing data according to emerging themes. Although the professed aim of cognitive coaching was to teach the process in order that the teachers would become self-analytical and self-modifying, this study found that the value of the coaching, after trust had been established in both the coach and the process, was in the dialoguing and the time set aside to do it. Once the coaching stopped providing the time to dialogue, to examine one's meanings and beliefs, so did the critical self-reflection. As a result ofthe cognitive coaching experience though, all participants grew in their feelings of efficacy, craftsmanship, flexibility, consciousness and interdependence. The actual and potential significance ofthis study was discussed according to implications for teacher supervision, professional development, school culture, further areas of research and to my personal growth and development.

An investigation into the functional role of the D1:1 and D1:2 polypeptides in photosystem II in cyanobacteria : the effect of changing PSI/PSII ratio on photoinhibition in Synechococcus sp. PCC7942 /

The cyanobacterium Synechococcus sp. PCC 7942 (Anacystis nidulans R2) adjusts its photosynthetic function by changing one of the polypeptides of photosystem II. This polypeptide, called Dl, is found in two forms in Synechococcus sp. PCC 7942. Changing the growth light conditions by increasing the light intensity to higher levels results in replacement of the original form of D 1 polypeptide, D 1: 1, with another form, D 1 :2. We investigated the role of these two polypeptides in two mutant strains, R2S2C3 (only Dl:l present) and R2Kl (only Dl:2 present) In cells with either high or low PSI/PSII. R2S2C3 cells had a lower amplitude for 77 K fluorescence emission at 695 nm than R2Kl cells. Picosecond fluorescence decay kinetics showed that R2S2C3 cells had shorter lifetimes than R2Kl cells. The lower yields and shorter lifetimes observed in the D 1 and Dl:2 containing cells. containing cells suggest that the presence of D 1: 1 results in more photochemical or non-photochemical quenching of excitation energy In PSII. One of the most likely mechanisms for the increased quenching in R2S2C3 cells could be an increased efficiency in the transfer of excitation energy from PSII to PSI. However, photophysical studies including 77 K fluorescence measurements and picosecond time resolved decay kinetics comparing low and high PSI/PSII cells did not support the hypothesis that D 1: 1 facilitates the dissipation of excess energy by energy transfer from PSII to PSI. In addition physiological studies of oxygen evolution measurements after photoinhibition treatments showed that the two mutant cells had no difference in their susceptibility to photoinhibition with either high PSI/PSII ratio or low PSI/PSII ratio. Again suggesting that, the energy transfer efficiency from PSII to PSI is likely not a factor in the differences between Dl:l and Dl:2 containing cells.

Psychopathy and self-monitoring : additive and interactive effects on self-presentation tactics /

The purpose of this study was to determine the relative contributions of psychopathy and self-monitoring to the prediction of self-presentation tactics (behaviours that individuals use to manipulate their self-image). Psychopathy is composed of two main factors: Factor 1, which includes manipulativeness and shallow affect, and Factor 2, which includes irresponsibility and anti-social behaviours. Self-monitoring is a personality trait that distinguishes between those who adapt their behaviour to fit different social situations (high self-monitors) and those who behave as they feel regardless of social expectations (low selfmonitors). It was hypothesized that self-monitoring would moderate the relationship between psychopathy and self-presentation tactics. One hundred and forty-nine university students completed the Self-Monitoring Scale (Snyder, 1974), the Self-Report Psychopathy Scale - Version III (Paulhus et aI., in press), the Self-Presentation Tactics scale (Lee, S., et aI., 1999), the HEXACO-PI (a measure ofthe six major factors of personality; Lee, K., & Ashton, 2004), and six scenarios that were created as a supplementary measure of the selfpresentation tactics. Results of the hierarchical multiple regression analyses showed that self-monitoring did moderate the relationship between psychopathy and three of the selfpresentation tactics: apologies, disclaimers, and exemplification. Further, significant interactions were observed between Factor 1 and self-monitoring on apologies and the defensive tactics subscale, between Factor 2 and self-monitoring on self-handicapping, and between Factor 1 and Factor 2 on exemplification. Contrary to expectations, the main effect of self-monitoring was significant for the prediction of nine tactics, while psychopathy was significant for the prediction of seven tactics. This indicates that the role of these two personality traits in the explanation of self-presentation tactics tends to be additive in nature rather than interactive. In addition. Factor 2 alone did not account for a significant amount of variance in any of the tactics, while Factor 1 significantly predicted nine tactics. Results are discussed with regard to implications and possible directions for future research.

A Study of role conflict, role ambiguity, locus of control, job satisfaction and participation in decision making among front-line vocational service workers for mentally retarded adults

This study was an investigation of individual and organizational factors, as perceived by front-line vocational service workers from Adult Rehabilitation Centres (ARC Industries) for mentally retarded adults. The specific variables which were measured included role conflict/role ambiguity (role factors), internal/external locus of control (individual differences), job satisfaction with work and supervision (job attitudes) and participation in deci~ion making (organizational factor). The exploration of these constructs was conducted by means of self-report questionnaires which were completed by sixty-nine out of a total of ninety front-line employees. The surveys were distributed in booklet form to nine distinct rehabilitation facilities from St. Catharines, West Lincoln, Greater Niagara, Port Colborne, WeIland, Fort Erie, Hamilton, Guelph and Brantford. The survey data was evaluated by the statisti.cal Package for the Social Sciences (SPSS) which used the Pearson Product Moment Correlation procedure and a compar~son of means test. A comparison of correlation coefficients test was also conducted. This statistical procedure was calculated mathematically. The results obtained from the statistical evaluation confirmed the prediction that self-reported measures of participation in decision making and satisfaction (work and supervision) would be negatively correlated with role conflict and role ambiguity. As well, the speculation that perceived satisfaction (work and supervision) would be positively correlated with participation in decision making was empirically supported. Internal and external locus of control did not contribute to a significant difference in r~sponses to role perceptions (conflict and ambiguity) , satisfaction (work and supervision) or the correlational relationship between participation in decision making and satisfaction (work and supervision). Overall, the findings from this study substantiated the importance of examining employee perceptions in the workplace and the interrelationships among individual and organizational variables. This research was considered a contribution to the general area of occupational stress and to the study of individuals in work organizations.

On the formulation and the calculation of the harmonic contributions to the Debye-Waller factor in metals (sodium)

The algebraic expressions for the anharmonic contributions to the Debye-Waller factor up to 0(A ) and 0 L% ) £ where ^ is the scattering wave-vector] have been derived in a form suitable for cubic metals with small ion cores where the interatomic potential extends to many neighbours. This has been achieved in terms of various wave-vector dependent tensors, following the work of Shukla and Taylor (1974) on the cubic anharmonic Helmholtz free energy. The contribution to the various wave-vector dependent tensors from the coulomb and the electron-ion terms in the interatomic metallic potential has been obtained by the Ewald procedure. All the restricted multiple whole B r i l l o u i n zone (B.Z.) sums are reduced to single whole B.Z. sums by using the plane wave representation of the delta function. These single whole B.Z. sums are further reduced to the •%?? portion of the B.Z. following Shukla and Wilk (1974) and Shukla and Taylor (1974). Numerical calculations have been performed for sodium where the Born-Mayer term in the interatomic potential has been neglected because i t is small £ Vosko (1964)3 • *n o^er to compare our calculated results with the experimental results of Dawton (1937), we have also calculated the r a t io of the intensities at different temperatures for the lowest five reflections (110), (200), (220), (310) and (400) . Our calculated quasi-harmonic results agree reasonably well with the experimental results at temperatures (T) of the order of the Debye temperature ( 0 ). For T » © ^ 9 our calculated anharmonic results are found to be in good agreement with the experimental results.The anomalous terms in the Debye-Waller factor are found not to be negligible for certain reflections even for T ^ ©^ . At temperature T yy Op 9 where the temperature is of the order of the melting temperature (Xm) » "the anomalous terms are found to be important almost for all the f i ve reflections.

The isolation, partial purification and preliminary characterization of a growth factor from chick embryo brains

Chicl( brain growth factor (CBGF) is a mitogen isolated from embryonic chick brains thought to have a potential role as a trophic factor involved in nerve dependent amphibian limb regeneration. In addition, CBGF stimulates 3H-thymidine incorporation in chick embryo brain astrocytes in vitro. In this study, cultured chick embryo brain non-neuronal cells were employed in a bioassay to monitor CBGF activity throughout various stages of its pllrification. Cell culture and assay conditions were optimized. Nonneuronal cells grew best on collagen-coated culture dishes in complete medium, were most responsive to a growth stimulus [10% fetal bovine serum (FBS)] at the second and third subcultures, and were healthiest when rendered "quiescent" in medium supplemented with 1% FBS. The most effective bioassay conditions consisted of a minimum 14.5 hour "quiescence" time (24 hours was used), a 6 hour "prestimulation" time, and a 24 hour 3H-thymidine labeling time. Four-day subconfluent primary non-neuronal cells consisted of 6.63% GFAP positive cells; as a result cultures were thought to be mainly composed of astroblasts. CBGF was purified from 18-day chick embryo brains by ultrafiltration through Amicon PM-30 and YM-2 membranes, size exclusion chromatography through a Biogel P6 column, and analytical reverse-phase high-performance liquid chromatography (rp-HPLC). The greatest activity resided in rp-HPLC fraction #7 (10 ng/ml) which was as effective as 10% FBS at stimulating 3H-thymidine incorporation in chick embryo brain nonneuronal cells. Although other researchers report the isolation of a mitogenic fraction consisting of 5'-GMP from the embryonic chick brain, UV absorbance spectra, rp-HPLC elution profiles, and fast atom bombardment (FAB) mass spectra indicated that CBGF is neither 5'-GMP nor 51-AMP. 2 Moreover, commercially available 5t-GMP was inhibitory to 3H-thymidine incorporation in the chick non-neuronal cells, while Sf-AMP had no effect. Upon treatment with pronase, the biological activity of fraction P6-3 increased; this increase was nearly 30% greater than what would be expected from a simple additive effect of any mitogenic activity of pronase alone together with P6-3 alone. This may suggest the presence of an inhibitor protein. The bioactive component may be a protein protected by a nucleoside/nucleotide or simply a nucleoside/nucleotide acting alone. While the FAB mass spectrum of rp-HPLC fraction #7 did not reveal molecular weight or sequence information, the ion of highest molecular weight was observed at m/z 1610; this is consistent with previous estimations of CBGF's size. 3

The role of personality and situational factors in forgiveness /

This study deals with personality and situational variables that influence forgiveness. The relations between empathy and forgiveness were studied, followed by the examination of the relation of these two variables to the Big Five personality traits, as well as honesty, absorption, the propensity to mystical experiences, and dissociation. Empathy was then tested as a mediating variable between the personality variables and forgiveness. Empathy and forgiveness were then studied in relation to childhood maltreatment. Finally, the effects of six different motivations to forgive were examined in relation to the personality variables. Participants were 142 undergraduate students recruited from the ftrst year psychology class at Brock University; 75% were either 18 or 19 years of age, and 84% were female. All of the variables were measured using self-report questionnaires. The relation between empathy and forgiveness was only partially replicated. In terms of personality, forgiveness was found to be related to honesty, emotionality, and agreeableness. Empathy at least partially mediated the relations between forgiveness and agreeableness, honesty and emotionality. Childhood maltreatment was negatively related to forgiveness, and positively related to openness to experience, absorption, and dissociation from reality, but not to the propensity for mystical experiences. Six different motivations for forgiveness emerged from an exploratory factor analysis. Out of these, Forgiveness to Promote Reconciliation was related to emotionality and dispositional empathy. Religious Forgiveness was related to honesty, emotionality, and mystical experiences. Forgiveness to Feel Better was related to honesty, emotionality, agreeableness, conscientiousness, absorption, mystical experiences, and empathy. Forgiveness to Assert Moral Superiority over the Injurer was negatively related to honesty, empathy, and positively related to extraversion. Forgiveness out of Fear was related to agreeableness. Finally, Altruistic Forgiveness was related to honesty, emotionality, and agreeableness, absorption and the propensity to mystical experiences. Altruistic Forgiveness correlated most highly with all the measures of forgiveness, followed by Forgiveness to Feel better. Altruistic forgiveness was also the motivation for forgiveness that correlated the highest with absorption.

Beyond g : putting multiple intelligences theory to the test /

The purpose of this study was to investigate Howard Gardner's (1983) Multiple Intelligences theory, which proposes that there are eight independent intelligences: Linguistic, Spatial, Logical/Mathematical, Interpersonal, Intrapersonal, Naturalistic, Bodily-Kinesthetic, and Musical. To explore Gardner's theory, two measures of each ability area were administered to 200 participants. Each participant also completed a measure of general cognitive ability, a personality inventory, an ability self-rating scale, and an ability self-report questionnaire. Nonverbal measures were included for most intelligence domains, and a wide range of content was sampled in Gardner's domains. Results showed that all tests of purely cognitive abilities were significantly correlated with the measure of general cognitive ability, whereas Musical, Bodily-Kinesthetic, and one of the Intrapersonal measures were not. Contrary to what Multiple Intelligences theory would seem to predict, correlations among the tests revealed a positive manifold and factor analysis indicated a large factor of general intelligence, with a mathematical reasoning test and a classification task from the Naturalistic domain having the highest ^- loadings. There were only minor sex differences in performance on the ability tests. Participants' self-estimates of ability were significantly and positively correlated with actual performance in some, but not all, intelligences. With regard to personality, a hypothesized association between Openness to Experience and crystallized intelligence was supported. The implications of the findings in regards to the nature of mental abilities were discussed, and recommendations for further research were made.

Psychographic characteristics of weekend wine tourists : a multiple case study of four wineries in the Niagara Region

The purpose of this study is to examine the psychographic (product attributes, motivation opinions, interest, lifestyle, values) characteristics of wine tourists along the Niagara wine r,~ute, located in Ontario, Canada, using a multiple case study method. Four wineries were selected, two wineries each on the East, and West sides of the wine route during the shoulder-season (January, February, 2004). Using a computer generated survey technique, tourists were approached to fill out a questionnaire on one of the available laptop computers, where a sample ofN=321 was obtained. The study findings revealed that there are three distinct wine tourist segments in the Niagara region. The segments were determined using an exploratory factor analysis (EFA) and a K-means cluster analysis: Wine Lovers, Wine Interested, and Wine Curious wine tourists. These three segments displayed significant differences in their, motivation for visiting a winery, lifestyles, values, and wine purchasing behaviour. This study also examined differences between winery locations, on the East and West sides of the Niagara wine route, with respect to the aforementioned variables. The results indicated that there were significant differences between the regions with respect to these variables. The findings suggest that these differences present opportunities for more effective marketing strategies based on the uniqueness of each region. The results of this study provide insight for academia into a method of psychographic market segmentation of wine tourists and consumer behaviour. This study also contributes to the literature on wine tourism, and the identification of psychographic characteristics of wine tourists, an area where little research has taken place.

Examining the role of goals and motives for physical activity and eating behaviour in commercial weight-loss program participants

Background: The purpose of this study was to examine the relationships between physical activity and healthy eating behaviour with the participant's motives and goals for each health behaviour. Methods: Participants (N 121; 93.2% female) enrolled in commercial weightloss programs at the time of data collection, completed self-reported instruments using a web-based interface that were in accordance with Deci and Ryan's (2002) Self-Determination Theory (SDT). Results: Multiple linear regression models revealed that motivation and goals collectively accounted for between 0.21 to 0.29 percent and 0.03 to 0.16 percent of the variance in physical and healthy eating behaviours in this sample. In general, goals regarding either behaviour did not appear to have strong predictive relationships with each health behaviour beyond the contributions of motives. Discussion: Overall, findings from this study suggest that motives seem to mattermore than goals for both physical activity and healthy eating behaviour in clientele of commercial weight-loss programs. Therefore commercial weight-loss program implementers may want to consider placing more attention on motives I than goals for their clientele when designing weight-loss and weight-maintenance initiatives.

An exploratory study for the discovery of non-invasive hepatocellular carcinoma biomarkers among high-risk hepatitis C virus infected patients

Hepatocellular Carcinoma (HCC) is a major healthcare problem, representing the third most common cause of cancer-related mortality worldwide. Chronic infections with Hepatitis B virus (HBV) and/or Hepatitis C virus (HCV) are the major risk factors for the development of HCC. The incidence of HBV -associated HCC is in decline as a result of an effective HBV vaccine; however, since an equally effective HCV vaccine has not yet been developed, there are 130 million HCV infected patients worldwide who are at a high-risk for developing HCC. Because reliable parameters and/or tools for the early detection of HCC among high-risk individuals are severely lacking, HCC patients are always diagnosed at a late stage where surgical solutions or effective treatment are not possible. Using urine as a non-invasive sample source, two different approaches (proteomic-based and genomic-based approaches) were pursued with the common goal of discovering potential biomarker candidates for the early detection of HCC among high-risk chronic HCV infected patients. Urine was collected from 106 HCV infected Egyptian patients, 32 of whom had already developed HCC and 74 patients who were diagnosed as HCC-free at the time of initial sample collection. In addition to these patients, urine samples were also collected from 12 healthy control individuals. Total urinary proteins, Trans-renal nucleic acid (Tr-NA) and microRNA (miRNA) were isolated from urine using novel methodologies and silicon carbide-loaded spin columns. In the first, "proteomic-based", approach, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to identify potential candidates from pooled urine samples. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR (qRT-PCR). This approach revealed that significant over-expression of three proteins: DJ-1, Chromatin Assembly Factor-1 (CAF-1) and 11 Moemen Abdalla HCC Biomarkers Heat Shock Protein 60 (HSP60), were characteristic events among HCC-post HCV infected patients. As a single-based HCC biomarker, CAF-1 over-expression identified HCC among HCV infected patients with a specificity of 90%, sensitivity of 66% and with an overall diagnostic accuracy of 78%. Moreover, the CAF-lIHSP60 tandem identified HCC among HCV infected patients with a specificity of 92%, sensitivity of 61 % and with an overall diagnostic accuracy of 77%. In the second genomic-based approach, two different approaches were processed. The first approach was the miRNA-based approach. The expression levels of miRNAs isolated from urine were studied using the Illumina MicroRNA Expression Profiling Assay. This was followed by qRT-PCR-based validation of deregulated expression of identified miRNA candidates among all the patients. This approach shed the light on the deregulated expression of a number of miRNAs, which may have a role in either the development of HCC among HCV infected patients (i.e. miR-640, miR-765, miR-200a, miR-521 and miR-520) or may allow for a better understanding of the viral-host interaction (miR-152, miR-486, miR-219, miR452, miR-425, miR-154 and miR-31). Moreover, the deregulated expression of both miR-618 and miR-650 appeared to be a common event among HCC-post HCV infected patients. The results of the search for putative targets of these two miRNA suggested that miR-618 may be a potent oncogene, as it targets the tumor-suppressor gene Low density lipoprotein-related protein 12 (LPR12), while miR-650 may be a potent tumor-suppressor gene, as it is supposed to downregulate the TNF receptor-associated factor-4 (TRAF4) oncogene. The specificity of miR-618 and miR-650 deregulated expression patterns for the early detection of HCC among HCV infected patients was 68% and 58%, respectively, whereas the sensitivity was 64% and 72%, respectively. When the deregulated expression of both miRNAs was combined as a tandem biomarker, the specificity and the sensitivity were 75% and 58% respectively. 111 Moemen Abdalla HCC Biomarkers In the second, "Trans-renal nucleic acid-based", approach, the urinary apoptotic nucleic acid (uaNA) levels of 70ng/mL or more were found to be a good predictor of HCC among chronic HCV infected patients. The specificity and the sensitivity of this diagnostic approach were 76% and 86%, respectively, with an overall diagnostic value of 81 %. The uaNA levels positively correlated to HCC disease progression as monitored by epigenetic changes of a panel of eight tumor-suppressor genes (TSGs) using methylation-sensitive PCR. Moreover, the pairing of high uaNA levels (:::: 70 ng/mL) and CAF-1 over-expreSSIOn produced a highly specific (l 00%) multiple-based HCC biomarker with an acceptable sensitivity of 64%, and with a diagnostic accuracy of 82%. In comparison to the previous pairing, the uaNA levels (:::: 70 ng/mL) in tandem with HSP60 over-expression was less specific (89%) but highly sensitive (72%), resulting in a diagnostic accuracy of 64%. The specificities of miR-650 deregulated expression in combination with either high uaNA content or HSP 60 over-expression were 82% and 79%, respectively, whereas, the sensitivities of these combinations were 64% and 58%, respectively. The potential biomarkers identified in this study compare favorably with the diagnostic accuracy of the a-fetoprotein levels test, which has a specificity of 75%, sensitivity of 68% and an overall diagnostic accuracy of 70%. Here we present an intriguing study which shows the significance of using urine as a noninvasive sample source for the identification of promising HCC biomarkers. We have also introduced new techniques for the isolation of different urinary macromolecules, especially miRNA, from urine. Furthermore, we strongly recommend the potential biomarkers indentified in this study as focal points of any future research on HCC diagnosis. A larger testing pool will determine if their use is practical for mass population screening. This explorative study identified potential targets that merit further investigation for the development of diagnostically accurate biomarkers isolated from 1-2 mL urine samples that were acquired in a non-invasive manner.

Living between two cultures : personality and adaptation in Chinese immigrant youth /

The aim of the present study was to examine the relationship between shyness and acculturation modes of Chinese immigrant youth in Canada and whether shyness moderates the relationship between acculturation and adaptation. In addition, I examined whether shyness, in conjunction with sociability, moderates the relationship between acculturation and adaptation. Ninety-nine young Chinese immigrants (42 men), ranging in age from 16 to 26 years old, completed a questionnaire that assessed their demographic information, acculturation modes, shyness, sociability, psychological adaptation Oife satisfaction, self-esteem, and depression), and socio-cultural adaptation. Results showed that Chinese orientation was significantly and negatively correlated with age, generation status, English proficiency, and length of residence in Canada. In contrast, Canadian orientation was significantly and positively correlated with generation status, English proficiency, and length of residence in Canada. Canadian orientation was also significantly and negatively correlated with shyness and positively correlated with sociability and psychological and socio-cultural adaptation. Participants who were shyer were more likely to have poorer psychological and socio-cultural adaptation, and to report lower life satisfaction and self-esteem and higher depression. Results from hierarchical multiple regression analyses indicated that Chinese immigrant youth who were separated had higher scores on shyness than those who were integrated and assimilated. There were no significant differences in shyness between youth who were separated and youth who were marginalized, nor were there differences between youth who were integrated and those who were assimilated. Furthermore, integrated Chinese youth reported significantly higher scores in sociability than those who were separated and marginalized but not significantly higher than those who were assimilated.' Shyness did not moderate the relationship between acculturation modes and psychological and socio-cultural adaptation. Unfortunately, the hypothesis to examine if shyness, in combination with sociability, moderated the relationship between acculturation and psychological adaptation could not be tested in the present study because of limitations in cell sizes. The findings suggested that how Chinese immigrant youth acculturate in the receiving country might not be the crucial factor in determining their adaptation. Instead, other factors, such as personality characteristics and nature of the acculturating group, may playa more crucial role. Shyness may have important ramifications for the acculturation and adaptation of young Chinese immigrants to a new society.

Vitamin D status and latent tuberculosis infection : a preliminary study in a group of healthy Mexican agricultural workers

Vitamin D metabolites are important in the regulation of bone and calcium homeostasis, but also have a more ubiquitous role in the regulation of cell differentiation and immune function. Severely low circulating 25-dihydroxyvitamin D [25(OH)D] concentrations have been associated with the onset of active tuberculosis (TB) in immigrant populations, although the association with latent TB infection (LTBI) has not received much attention. A previous study identified the prevalence of LTBI among a sample of Mexican migrant workers enrolled in Canada's Seasonal Agricultural Workers Program (SA WP) in the Niagara Region of Ontario. The aim of the present study was to determine the vitamin D status of the same sample, and identify if a relationship existed with LTBI. Studies of vitamin D deficiency and active TB are most commonly carried out among immigrant populations to non-endemic regions, in which reactivation of LTBI has occurred. Currently, there is limited knowledge of the association between vitamin D deficiency and LTBI. Entry into Canada ensured that these individuals did not have active TB, and L TBI status was established previously by an interferon-gamma release assay (IGRA) (QuantiFERON-TB Gold In-Tube®, Cellestis Ltd., Australia). Awareness of vitamin D status may enable individuals at risk of deficiency to improve their nutritional health, and those with LTBI to be aware of this risk factor for disease. Prevalence of vitamin D insufficiency among the Mexican migrant workers was determined from serum samples collected in the summer of 2007 as part of the cross sectional LTBI study. Samples were measured for concentrations of the main circulating vitamin D metabolite, 25(OH)D, with a widely used 1251 250HD RIA (DiaSorin Inc.®, Stillwater, MN), and were categorized as deficient «37.5 nmoI/L), insufficient (>37.5 nmollL, < 80 nmol/L) or sufficient (2::80 nmoI/L). Fisher's exact tests and t tests were used to determine if vitamin D status (sufficiency or insufficiency) or 25(OH)D concentrations significantly differed by sex or age categories. Predictors of vitamin D insufficiency and 25(OH)D concentrations were taken from questionnaires carried out during the previous study, and analyzed in the present study using multiple regression prediction models. Fisher's exact test and t test was used to determine if vitamin D status or 25(OH)D concentration differed by LTBI status. Strength of the relationship between interferongamma (IFN-y) concentration (released by peripheral T cells in response to TB antigens) and 25(OH)D concentration was analyzed using a Spearman correlation. Out of 87 participants included in the study (78% male; mean age 38 years), 14 were identified as LTBI positive but none had any signs or symptoms of TB reactivation. Only 30% of the participants were vitamin D sufficient, whereas 68% were insufficient and 2% were deficient. Significant independent predictors of lower 25(OH)D concentrations were sex, number of years enrolled in the SA WP and length of stay in Canada. No significant differences were found between 25(OH)D concentrations and LTBI status. There was a significant moderate correlation between IFN-y and 25(OH)D concentrations ofLTBI-positive individuals. The majority of participants presented with Vitamin D insufficiency but none were severely deficient, indicating that 25(OH)D concentrations do not decrease dramatically in populations who temporarily reside in Canada but go back to their countries of origin during the Canadian winter. This study did not find a statistical relationship between low levels of vitamin D and LTBI which suggests that in the presence of overall good health, lower than ideal levels of 2S(OH)D, may still be exerting a protective immunological effect against LTBI reactivation. The challenge remains to determine a critical 2S(OH)D concentration at which reactivation is more likely to occur.

Relation of temperament and authoritative parenting on subtypes of adolescent behaviour

Over the years, researchers have investigated direct, conditional, and meditational pathways of adolescent aggression in relation to both temperament and parenting behaviours. However, no study to date has considered these relations with respect to a measure of aggression differentiated by form (e.g., overt, relational) and function (e.g., proactive, reactive). The present study examined the differential association of adolescent temperament and authoritative parenting on four subtypes of aggression. Participants included mothers, fathers, and one adolescent (between the ages of 10-19) from 663 families, recruited through random digit dialing. Parents reported on their child's temperament and occurrence of aggressive behaviours in addition to the perception of their own authoritative parenting. Adolescents reported on their own temperament and aggressive behaviours as well as on both their mother and father's authoritative parenting. Multiple regression analyses confirmed predictions that some aspects of temperament and authoritative parenting provide motivation towards the engagement of different aggressive behaviours. For example, higher negative affect was related to reactive types of aggression, whereas a strong desire for novel or risky behaviours related to proactive aggression. However, differences in effortful control altered the trajectory for both relationships. Higher levels of self-regulation reduced the impact of negative affect on reactive-overt aggression. Greater self-regulation also reduced the impact of surgency on proactive-overt aggression when age was a factor. Structural equation modeling was then used to assess the process through which adolescents become more or less susceptible to impulsive behaviours. Although the issue ofbi-directionality cannot be ruled out, temperament characteristics were the proximal correlate for aggression subtypes as opposed to authoritative parenting dimensions. Effortful control was found to partially mediate the relation between parental acceptancelinvolvement and reactive-relational and reactive-overt aggression, suggesting that higher levels of warmth and support as perceived by the child related to increased levels of self-regulation and emotional control, which in tum lead to less reactive-relational and less reactive-overt types of aggression in adolescents. On the other hand, negative affect partially mediated the relation between parental psychological autonomy granting and these two subtypes of aggression, supporting predictions that higher levels of autonomy granting (perceived independence) related to lower levels of frustration, which in tum lead to less reactive-relational and reactive-overt aggression in adolescents. Both findings provide less evidence for the evocative person-environment correlation and more support for temperament being an open system shaped by experience and authoritative parenting dimensions. As one of the first known studies examining the differential association of authoritative parenting and temperament on aggression subtypes, this study demonstrates the role parents can play in shaping and altering their children's temperament and the effects it can have on aggressive behaviour.