Correlated Neural Activity and Encoding of Behavior across Brains of Socially Interacting Animals.

Social interactions involve complex decision-making tasks that are shaped by dynamic, mutual feedback between participants. An open question is whether and how emergent properties may arise across brains of socially interacting individuals to influence social decisions. By simultaneously performing microendoscopic calcium imaging in pairs of socially interacting mice, we find that animals exhibit interbrain correlations of neural activity in the prefrontal cortex that are dependent on ongoing social interaction. Activity synchrony arises from two neuronal populations that separately encode one's own behaviors and those of the social partner. Strikingly, interbrain correlations predict future social interactions as well as dominance relationships in a competitive context. Together, our study provides conclusive evidence for interbrain synchrony in rodents, uncovers how synchronization arises from activity at the single-cell level, and presents a role for interbrain neural activity coupling as a property of multi-animal systems in coordinating and sustaining social interactions between individuals.

Men in Macau SAR have higher prevalence in metabolic syndrome and among related metabolic components: a cross-sectional Macau Health Survey.

BACKGROUND: Macau has recently experienced expansive socioeconomic growth, leading to lifestyle changes that could have contributed to the development of certain diseases. Little information exists on the prevalence of metabolic syndrome (MetS) and associated risk factors. This information is important, since the management of MetS is tightly connected with prevention of cardiovascular diseases in the population. METHODS: This study is based on the cross-sectional Macau Health Survey 2006. Information on anthropometry, physical measurements, socio-demographics, laboratory tests and life-style habits was collected by trained health professionals from a random sub-population sample, aged 18-44 (32.6 ± 8.3). Body Mass Index (BMI) cut-offs were based on WHO criteria for Asian population. The prevalence of MetS, as defined by the International Diabetes Federation was calculated and the associated lifestyle factors were analysed. RESULTS: Among Macau's adults (n = 1592), the age-adjusted prevalence of MetS was over two times higher in men (10.5%) than in woman (3.7%), (p <0.01). 15.8% were overweight (BMI ≥23 < 25) and 18.8% were obese (BMI ≥25). Man had significantly higher risk profile in almost all components of MetS (p <0.001), except the waist circumference and HDL. BMI, age and education were significantly related to MetS in both genders (p <0.001). CONCLUSIONS: We found significant gender differences in MetS among the 18-44 year old population of Macau, which should be addressed separately in the gender-specific preventive strategies.

An iterative approach to enhance the clinical learning experience in Macao nursing education.

OBJECTIVE: The aim of this study was to reduce or eliminate the stressors to enhance nursing students' clinical learning experience through implementation of an iterative approach that developed a personalised response to student stress. METHODS: A prospective cohort research design was applied to collect data from a sample of undergraduate nursing students across the four study years. An iterative approach was employed to improve students' learning experience and the Stressors in Nursing Students Scale-Chinese Version (SINS-CN) was used to measure student stress. Key problems encountered by students were identified, refined and the responding solutions were worked out and implemented among this group of students through their first year to fourth year. RESULTS: The overall SINS-CN mean score (2.17-2.82) of students was declined to a moderate level. CONCLUSIONS: Having implemented iterative approach to address factors that led to stressful environments encountered by the nursing students, the overall stress score and each sub-dimension score decreased significantly. Therefore, it is recommended that this approach could be adopted by other colleagues in the nursing arena around the world.

The age of menopause and the menopause transition in a multiracial population: a nation-wide Singapore study.

OBJECTIVE: To describe the prevalence of menopausal symptoms, define the mean age of menopause, and determine contributory factors, which influence the experience of symptoms among Singaporean women of different racial groups. DESIGN: Cross-sectional nation-wide study of a random sample of 1000 women drawn from the entire population of Singaporean female (Chinese, Malay, and Indian) citizens between 45 and 60 years of age. Face-to-face interviews using structured questionnaires were conducted. RESULTS: The response rate was 69.9%. The mean age of natural menopause was 49.0 years. This was not significantly different between the three ethnic groups. Increasing parity delayed the age of menopause (P=0.007). Muscle and joint ache was the most commonly reported symptom (52.6%). Although the prevalence of significant hot flushes in the general study population was low (3.9%), it was the most commonly reported complaint by peri-menopausal women (14.6%). Prevalence of significant hot flushes decreased with time from menopause (P=0.007) and completely disappeared beyond the fifth year of menopause. Recent unhappy events were associated with an increased risk of symptoms (P<0.001). Women of Chinese origin experienced a lower risk of menopausal symptoms when compared with other ethnic groups (P<0.05). CONCLUSION: The mean age of menopause was 49.0 years among Singaporean women. Ethnicity and recent unhappy events were two major factors, which influenced the risk of experiencing menopausal symptoms. Among the three ethnic groups studied, Chinese women were the least likely to experience disturbing menopausal symptoms. The overall prevalence of menopausal symptoms was low when compared to studies on women in western societies.

The Singapore impaired glucose tolerance follow-up study: does the ticking clock go backward as well as forward?

OBJECTIVE: To 1). document the change in glucose tolerance for subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) over time, 2). identify baseline factors associated with worsening of glucose tolerance, and 3). determine whether cardiovascular disease (CVD) risk factors associated with IGT improved in tandem with glucose tolerance. RESEARCH DESIGN: Subjects with IGT and NGT (matched for age, sex, and ethnic group) were identified from a cross-sectional survey conducted in 1992. Subjects with IGT (297) and NGT (298) (65.0%) were reexamined in 2000. Glucose tolerance (assessed by 75-g oral glucose tolerance test), anthropometric data, serum lipids, blood pressure, and insulin resistance were determined at baseline and at the follow-up examination. RESULTS: For NGT subjects, 14.0% progressed to IGT and 4.3% to diabetes over 8 years. For IGT subjects, 41.4% reverted to NGT, 23.0% remained impaired glucose tolerant, and 35.1% developed diabetes. Obesity, hypertriglyceridemia, higher blood pressure, increased insulin resistance, and lower HDL cholesterol at baseline were associated with worsening of glucose tolerance in both IGT and NGT subjects. Those with IGT who reverted to NGT remained more obese and had higher blood pressure than those with NGT in both 1992 and 2000. However, serum triglyceride, HDL cholesterol, and insulin resistance values in 2000 became indistinguishable from those of subjects who maintained NGT throughout the study period. CONCLUSIONS: Some, but not all, CVD risk factors associated with IGT and with the risk of future diabetes normalize when glucose tolerance normalizes. Continued surveillance and treatment in subjects with IGT, even after they revert to NGT, may be important in the prevention of CVD.

Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease.

OBJECTIVE: To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG. RESEARCH DESIGN AND METHODS: Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity. RESULTS: Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT. CONCLUSIONS: Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG.

Higher fasting insulin but lower fasting C-peptide levels in African Americans in the US population.

BACKGROUND: Fasting serum insulin and fasting serum C-peptide are risk factors for developing type 2 diabetes. Because of the higher incidence of type 2 diabetes in African Americans and Hispanic Americans, it is likely that these groups may differ from non-Hispanic whites in their levels of insulin and C-peptide. METHODS: We analyzed data from a nationally representative sample of adults in the US population for whom sociodemographic, clinical, and laboratory information were obtained. The data were used to describe distributions of fasting insulin and fasting C-peptide in non-Hispanic white, non-Hispanic black, and Mexican American men and women aged >or=20 years without a medical history of diabetes. RESULTS: Among men, Mexican Americans had higher insulin values than non-Hispanic whites and blacks. Among women, both Mexican Americans and blacks had higher insulin values than whites. For C-peptide, differences by sex and race-ethnicity paralleled those seen for fasting insulin with the exception that black men had significantly lower C-peptide values than whites and Mexican Americans. After adjustment for age, fasting plasma glucose (FPG), body mass index (BMI), and waist-to-hip ratio (WHR), the higher levels for insulin in blacks and Mexican Americans remained; both black men and women had significantly lower C-peptide values than whites and Mexican Americans. The molar ratio of fasting C-peptide to fasting insulin was similar for men and women in each race-ethnic group. However, blacks had substantially lower ratios than whites and Mexican Americans. CONCLUSIONS: We found wide variations in fasting insulin and fasting C-peptide levels by race and ethnicity in US adults that were not explained by confounding factors, primarily measures of obesity. Most notably, the higher fasting insulin and lower fasting C-peptide levels in blacks implies that there is a derangement in insulin clearance and an impairment in beta-cell function in blacks compared with whites and Mexican Americans.