Molecular aspects of boundary lubrication by human lubricin : effect of disulfide bonds and enzymatic digestion

Lubricin (LUB) is a glycoprotein of the synovial cavity of human articular joints, where it serves as an antiadhesive, boundary lubricant, and regulating factor for the cartilage surface. It has been proposed that these properties are related to the presence of a long, extended, heavily glycosylated and highly hydrated mucinous domain in the central part of the LUB molecule. In this work, we show that LUB has a contour length of 220 ± 30 nm and a persistence length of ≤10 nm. LUB molecules aggregate in oligomers where the protein extremities are linked by disulfide bonds. We have studied the effect of proteolytic digestion by chymotrypsin and removal of the disulfide bonds, both of which mainly affect the N− and C− terminals of the protein, on the adsorption, normal forces, friction (lubrication) forces, and wear of LUB layers adsorbed on smooth, negatively charged mica surfaces, where the protein naturally forms lubricating polymer brush-like layers. After in situ digestion, the surface coverage was drastically reduced, the normal forces were altered, and both the coefficient of friction and the wear were dramatically increased (the COF increased to μ = 1.1−1.9), indicating that the mucinous domain was removed from the surface. Removal of disulfide bonds did not change the surface coverage or the overall features of the normal forces; however, we find an increase in the friction coefficient from μ = 0.02−0.04 to μ = 0.13−1.17 in the pressure regime below 6 atm, which we attribute to a higher affinity of the protein terminals for the surface. The necessary condition for LUB to be a good lubricant is that the protein be adsorbed to the surface via its terminals, leaving the central mucin domain free to form a low-friction, surface-protecting layer. Our results suggest that this “end-anchoring” has to be strong enough to impart the layer a sufficient resistance to shear, but without excessively restricting the conformational freedom of the adsorbed proteins.

Diabetes MILES – The Netherlands: rationale, design and sample characteristics of a national survey examining the psychosocial aspects of living with diabetes in Dutch adults

Background : As the number of people with diabetes is increasing rapidly worldwide, a more thorough understanding of the psychosocial aspects of living with this condition has become an important health care priority. While our knowledge has grown substantially over the past two decades with respect to the physical, emotional and social difficulties that people with diabetes may encounter, many important issues remain to be elucidated. Under the umbrella of the Diabetes MILES (Management and Impact for Long-term Empowerment and Success) Study International Collaborative, Diabetes MILES – The Netherlands aims to examine how Dutch adults with diabetes manage their condition and how it affects their lives. Topics of special interest in Diabetes MILES - The Netherlands include subtypes of depression, Type D personality, mindfulness, sleep and sexual functioning.

Methods/design : Diabetes MILES – The Netherlands was designed as a national online observational study among adults with diabetes. In addition to a main set of self-report measures, the survey consisted of five complementary modules to which participants were allocated randomly. From September to October 2011, a total of 3,960 individuals with diabetes (40% type 1, 53% type 2) completed the battery of questionnaires covering a broad range of topics, including general health, self-management, emotional well-being and contact with health care providers. People with self-reported type 1 diabetes (specifically those on insulin pump therapy) were over-represented, as were those using insulin among respondents with self-reported type 2 diabetes. People from ethnic minorities were under-represented. The sex distribution was fairly equal in the total sample, participants spanned a broad age range (19–90 years), and diabetes duration ranged from recent diagnosis to living with the condition for over fifty years.

Discussion : The Diabetes MILES Study enables detailed investigation of the psychosocial aspects of living with diabetes and an opportunity to put these findings in an international context. With several papers planned resulting from a pooled Australian-Dutch dataset and data collections planned in other countries, the Diabetes MILES Study International Collaborative will contribute substantially to identifying potentially unmet needs of those living with diabetes and to inform clinical research and care across the globe.

Glucose enhancement of recognition memory: differential effects on effortful processing but not aspects of 'remember-know' responses

The administration of a glucose drink has been shown to enhance cognitive performance with effect sizes comparable with those from pharmaceutical interventions in human trials. In the memory domain, it is currently debated whether glucose facilitation of performance is due to differential targeting of hippocampal memory or whether task effort is a more important determinant. Using a placebo-controlled, double-blind, crossover 2(Drink: glucose/placebo) × 2(Effort: ± secondary task) design, 20 healthy young adults' recognition memory performance was measured using the 'remember-know' procedure. Two high effort conditions (one for each drink) included secondary hand movements during word presentation. A 25 g glucose or 30 mg saccharine (placebo) drink was consumed 10 min prior to the task. The presence of a secondary task resulted in a global impairment of memory function. There were significant Drink × Effort interactions for overall memory accuracy but no differential effects for 'remember' or 'know' responses. These data suggest that, in some circumstances, task effort may be a more important determinant of the glucose facilitation of memory effect than hippocampal mediation. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Does gender moderate the subjective measurement and structural paths in behavioural and cognitive aspects of gambling disorder in treatment-seeking adults?

Introduction
Gender differences have been observed in the pathogenesis of gambling disorder and gambling related urge and cognitions are predictive of relapse to problem gambling. A better understanding of these mechanisms concurrently may help in the development of more directed therapies.
Methods
We evaluated gender effects on behavioural and cognitive paths to gambling disorder from self-report data. Participants (N = 454) were treatment-seeking problem gamblers on first presentation to a gambling therapy service between January 2012 and December 2014. We firstly investigated if aspects of gambling related urge, cognitions (interpretive bias and gambling expectancies) and gambling severity were more central to men than women. Subsequently, a full structural equation model tested if gender moderated behavioural and cognitive paths to gambling severity.
Results
Men (n = 280, mean age = 37.4 years, SD = 11.4) were significantly younger than women (n = 174, mean age = 48.7 years, SD = 12.9) (p < 0.001). There was no gender difference in conceptualising latent constructs of problem gambling severity, gambling related urge, interpretive bias and gambling expectancies. The paths for urge to gambling severity and interpretive bias to gambling severity were stronger for men than women and statistically significant (p < 0.001 and p = 0.004, respectively) whilst insignificant for women (p = 0.164 and p = 0.149, respectively). Structural paths for gambling expectancies to gambling severity were insignificant for both men and women.
Conclusion
This study detected an important signal in terms of theoretical mechanisms to explaining gambling disorder and gender differences. It has implications for treatment development including relapse prevention.

Which aspects of socioeconomic status are related to obesity among men and women?

OBJECTIVE: This study aimed to investigate the relationships between body weight and fat distribution, and four empirically derived domains of socioeconomic status: employment, housing, migration status and family unit.

DESIGN: A population-based study was used.

PARTICIPANTS: A total of 8667 randomly-selected adults (4167 men; 4500 women) who participated in the 1995 Australian National Health and Nutrition Surveys provided data on a range of health factors including objective height, weight and body fat distribution, and a range of sociodemographic indicators.

RESULTS: Results demonstrated associations for women, after controlling for age, between the employment domain, and body mass index and waist-to-hip ratio. Low status employed women were 1.4 times as likely to be overweight as high status employed women. There were less consistent relationships observed among these factors for men. Relationships between family unit and indicators of body weight and body fat distribution were observed for both men and women, with those who were married, particularly men (OR=1.6, 95% CI 1.4-2.0), at higher risk of overweight. The migration and housing socioeconomic status domains were not consistently associated with body mass index or waist-to-hip ratio.

CONCLUSIONS: These findings indicate that different components of socioeconomic status may be important in predicting obesity, and thus should be examined separately. Future research would benefit from investigating the underlying mechanisms governing the relationships between socioeconomic status domains further, particularly those related to employment and family unit and obesity

Women's perceptions of familial aspects of breast cancer

Women’s understanding of familial aspects of breast cancer was examined using both focus groups and interviews. The studies covered issues related to perceptions of breast cancer risk factors, perceived breast cancer risk, understanding of risk information, and family history of breast cancer as a risk factor. Study 1 consisted of four focus group discussions with women from the general community. Study 2 comprised ten face-to-face interviews with women who had a family history of breast cancer. The results in combination indicate a fairly high level of awareness of family history as a risk factor for breast cancer. However, the definition of a familial history of breast cancer differed between the groups, with those without a family history being more inclusive than those with such a history. The paper concludes with suggestions for use by those developing resources materials for those with a familial history of breast cancer.

The Strategic outsourcing Decision of IT and eCommerce: The Case of Small Businesses in New Zealand

In New Zealand, small to medium-sized enterprises (SMEs) play a very important role in the economy by their contribution to both employment and gross domestic product. Addressing issues pertinent to SMEs is of paramount importance in driving this sector forward. Information Technology (IT) emerges as one main enabler for SMEs in automating their operations, seeking new opportunities and enhancing their strategic business positioning in local and international markets. However, the inability of SMEs to handle the dynamic nature of IT due to problems inherent in their size, structure and resources, makes it difficult for them to take appropriate decisions to benefit from the IT technologies. The advent of eCommerce (EC) has only compounded this problem. One way out of this complex situation is to outsource the IT and EC technology requirements by the SMEs. This study endeavours to identify the pattern of IT and EC outsourcing issues of SMEs within New Zealand. This research attempts to identify the main driver for IT/EC outsourcing in SMEs as well as to explore the problems of IT outsourcing and makes suggestions for further research in this crucial sector.

Molecular and cellular aspects of copper transport in developing mammals

Copper is an essential trace element that requires tightly regulated homeostatic mechanisms to ensure adequate supplies without any toxic effects because of the ability of the metal ion to catalyze the formation of free radicals. The Cu-ATPases, ATP7A and ATP7B, play an important role in the physiological regulation of copper. Adequate supplies of copper are particularly important in developing animals, and in humans this is illustrated by mutations of ATP7A that cause the copper deficiency condition Menkes disease, which is fatal in early childhood. In contrast, mutations in ATP7B result in the genetic toxicosis, Wilson disease. We propose that the physiological regulation of copper is accomplished mainly by the intracellular copper-regulated trafficking of the Cu-ATPases. This process allows the overall copper status in the body to be maintained when levels of copper in the diet alter. A study of the defects in mouse models of Menkes and Wilson diseases has demonstrated that both ATPases play an important role in supplying copper to the developing fetus and neonate

From local to national: aspects of mapping the welfare third sector in Australia

The paper charts the authors' research experiences in various types of sociological mapping ofc ommunity or third sector organisations. Specifically this was a search for a way of understanding how third sector organisations dealing with welfare issues were operating in Australia in the mid I990s.

The paper tells the story of how the researchers worked through the implications of being faced initially with a dearth of information about their subject and of how lessons were learnt about the disjunctions between what is formally given as textbook knowledge about research practice and what actually can and does happen: that is, the relationship between the theory and the practice of research.

In discussing the creation of a database of organisations, conducting focus groups and a national sample survey, the paper comments on some of the practical problems facing third sector researchers as well as looking at concept generation and typology building as analytical tools.

Making use of IT: web page

The use of the Web has become an essential part of teaching and learning in Australian schools. Nevertheless, many students lack knowledge of how to properly evaluate and cite Web-sourced information. This paper presents criteria, by which students can judge the reliability of Web resources, and guidelines on the citation of Web information. These strategies have been implemented successfully by the authors in their classes.