Longitudinal relations of perceived availability of neighborhood sport facilities with physical activity in adolescents: an analysis of potential moderators

Background
Little is known about the longitudinal relations of environment attributes and leisure-time physical activity (PA) in adolescents, and the moderating effects of individual characteristics. This study examined the longitudinal association of the perceived availability of neighborhood sport facilities with leisure-time PA, and the potential moderating effects of age, past PA behavior, and weight status in adolescents.

Methods
Among 20,933 follow-up subjects (60.9% of 34,369 baseline subjects), 9993 from 32 Hong Kong secondary schools were successfully matched with baseline (mean duration 16 months; SD 1.7) and had complete information. At baseline and follow-up, respondents reported their leisure-time PA, weight, height, and the presence of sport facilities in the neighborhood.

Results
Increased perceived availability of sport facilities from baseline to follow-up predicted more leisure-time PA at follow-up (β = 1.029; 95% CI: 1.011–1.047) overall. This effect was modified by baseline PA, with a significant effect observed only among those who had engaged in leisure-time PA more than 3 times a week.

Conclusions
Increasing awareness of neighborhood sport facilities or building more such facilities may help active adolescents maintain or increase their leisure-time PA. However, more comprehensive multilevel interventions that aim at enhancing potential social, personal, and environmental PA-related factors may be needed to motivate inactive adolescents.

Physical activity for cancer survivors : a meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.

Adolescents’ physical activity : competition between perceived neighborhood sport facilities and home media resources

Objective. To examine the independent, competing, and interactive effects of perceived availability of specific types of media in the home and neighborhood sport facilities on adolescents’ leisure-time physical activity (PA).

Methods. Survey data from 34 369 students in 42 Hong Kong secondary schools were collected (2006–07). Respondents reported moderate-to-vigorous leisure-time PA, presence of sport facilities in the neighborhood and of media equipment in the home. Being sufficiently physically active was defined as engaging in at least 30 minutes of non-school leisure-time PA on a daily basis. Logistic regression and post-estimation linear combinations of regression coefficients were used to examine the independent and competing effects of sport facilities and media equipment on leisure-time PA.

Results. Perceived availability of sport facilities was positively (ORboys = 1.17; ORgirls = 1.26), and that of computer/Internet negatively (ORboys = 0.48; ORgirls = 0.41), associated with being sufficiently active. A significant positive association between video game console and being sufficiently active was found in girls (ORgirls = 1.19) but not in boys. Compared with adolescents without sport facilities and media equipment, those who reported sport facilities only were more likely to be physically active (ORboys = 1.26; ORgirls = 1.34), while those who additionally reported computer/Internet were less likely to be physically active (ORboys = 0.60; ORgirls = 0.54).

Conclusions. Perceived availability of sport facilities in the neighborhood may positively impact on adolescents’ level of physical activity. However, having computer/Internet may cancel out the effects of active opportunities in the neighborhood. This suggests that physical activity programs for adolescents need to consider limiting the access to computer-mediated communication as an important intervention component.

High genetic diversity is not essential for successful introduction

Some introduced populations thrive and evolve despite the presumed loss of diversity at introduction. We aimed to quantify the amount of genetic diversity retained at introduction in species that have shown evidence of adaptation to their introduced environments. Samples were taken from native and introduced ranges of Arctotheca populifolia and Petrorhagia nanteuilii. Using microsatellite data, we identified the source for each introduction, estimated genetic diversity in native and introduced populations and calculated the amount of diversity retained in introduced populations. These values were compared to those from a literature review of diversity in native, confamilial populations and to estimates of genetic diversity retained at introduction. Gene diversity in the native range of both species was significantly lower than for confamilials. We found that, on average, introduced populations showing evidence of adaptation to their new environments retained 81% of the genetic diversity from the native range. Introduced populations of P. nanteuilii had higher genetic diversity than found in the native source populations, whereas introduced populations of A. populifolia retained only 14% of its native diversity in one introduction and 1% in another. Our literature review has shown that most introductions demonstrating adaptive ability have lost diversity upon introduction. The two species studied here had exceptionally low native range genetic diversity. Further, the two introductions of A. populifolia represent the largest percentage loss of genetic diversity in a species showing evidence of substantial morphological change in the introduced range. While high genetic diversity may increase the likelihood of invasion success, the species examined here adapted to their new environments with very little neutral genetic diversity. This finding suggests that even introductions founded by small numbers of individuals have the potential to become invasive.

Non-covalent surface modification of boron nitride nanotubes for enhanced catalysis

Boron nitride nanotubes were functionalized with microperoxidase-11 in aqueous media, showing improved catalytic performance due to a strong electron coupling between the active centre of microperoxidase-11 and boron nitride nanotubes.

Efficacy of using cancer stem cell markers in isolating and characterizing liver cancer stem cells

Recent evidence suggests that a subset of hepatocellular carcinomas (HCCs) are derived from liver cancer stem cells (LCSCs). In order to isolate and characterize LCSCs, reliable markers that are specific to these cells are required. We evaluated the efficacy of a range of cancer stem cell (CSC) markers in isolating and characterizing LCSCs. We show that the most widely used CSC markers are not specific to LCSCs. By western analysis, protein expression of the common markers showed no significant difference between HCC tumor tissues and adjacent non-cancerous liver. Further, isolation of LCSCs from common HCC cell lines using FACScan and microbeads showed no consistent marker expression pattern. We also show that LCSCs have unique subtypes. Immunohistochemistry of HCC tissues showed that different HCCs express unique combinations of LCSC markers. Quantitative real-time polymerase chain reaction analysis showed that LCSCs isolated using different markers in the same HCC phenotype had different expression profiles. Likewise, LCSCs isolated from different HCC phenotypes with the same marker also had unique expression profiles and displayed varying resistance profiles to Sorafenib. Thus, using a range of commonly used CSC markers in HCCs and cell lines, we demonstrate that currently available markers are not specific for LCSCs. LCSCs have unique subtypes that express distinctive combinations of LCSC markers and altered drug resistance profiles, making their identification problematic.

Towards designing privacy-preserving signature-based IDS as a service : a study and practice

With the advent of Cloud Computing, IDS as a service (IDSaaS) has been proposed as an alternative to protect a network (e.g., financial organization) from a wide range of network attacks by offloading the expensive operations such as the process of signature matching to the cloud. The IDSaaS can be roughly classified into two types: signature-based detection and anomaly-based detection. During the packet inspection, no party wants to disclose their own data especially sensitive information to others, even to the cloud provider, for privacy concerns. However, current solutions of IDSaaS have not much discussed this issue. In this work, focus on the signature-based IDSaaS, we begin by designing a promising privacy-preserving intrusion detection mechanism, the main feature of which is that the process of signature matching does not reveal any specific content of network packets by means of a fingerprint-based comparison. We further conduct a study to evaluate this mechanism under a cloud scenario and identify several open problems and issues for designing such a privacy-preserving mechanism for IDSaaS in a practical environment.

Visionnaire 2013

Visionnaire: a screening of graduate and masters short films: Wolf, Shaw, Mawrgan. Treasure, Horton, Kyle. Descent, Coughlin, Michael. Cut, Hendriks, Frouwke. A Silent Waltz, Lefoe, Kelsey; Elliott, Isaac; Nanayakkara, Ashini; Tillett, Michael; Teychenne, Danielle; Axiaq, Christopher. Siren, Brander, Dale; Heath, Katherine, Stielow, Rebecca; Bellamy, Edward; Boldeman, Emma; Dong, Jing. The Man Who Cared Too Much, Milner, Robert; Di Quinzio, Carl; Lancaster, Tabitha; Hennequin, Blake; Pinnock, Alicia; Hay, Sarah. Perspective, Hampson, Matt; Gubieski, Alex; Lam, Yen; Jokomo, Nyasha; Carew, Keanan; Burr, Harrison. A Cut Above, Giebler, Heather; Blythe, Carolyn, Carell, Eden; Lai, Cyrus; Rattenbury, Todd; Gatsios, Isaac. Pumpkins, Davies, Brooke; Scharf, Harrison; Jayawardena, Kevin; Lee, Sebastian; Haidari, Ali; Morris, Travis. The Runner, Mitchinson, Liz; Kelly, Rhin; Fomin, Nina; Luxa, Haili; Williams-Pate, Robert; Karoutsos, Antonios. Doors, Sadeghi, Sam; Ward, Ben; Thomson, Alana; Brown, Sam; Earl, Richard; Watterson, James. Daddy’s Little Girl, Dahlenburg, Zoe; Atalla, Joanna; McConnell, Adam; Perri, Tim; Turnbull, Sophie; Leszczynski, Dale. Hopscotch, Egenes, Silge Vikor; Burns, Matt; Fuller, Kelly; Wurm, Christopher; Parker, Stephen; Carson, Brooke Aung.