Using scale characteristics and water temperature to reconstruct growth rates of juvenile steelhead Oncorhynchus mykiss.

Juvenile steelhead Oncorhynchus mykiss from a northern California Central Valley population were reared in a controlled laboratory experiment. Significantly different rates of growth were observed among fish reared under two ration treatments and three temperature treatments (8, 14 and 20°C). Wider circulus spacing and faster deposition was associated with faster growth. For the same growth rate, however, circulus spacing was two-fold wider and deposited 36% less frequently in the cold compared to the hot temperature treatment. In a multiple linear regression, median circulus spacing and water temperature accounted for 68% of the variation in observed O. mykiss growth. These results corroborate previous research on scale characteristics and growth, while providing novel evidence that highlights the importance of water temperature in these relationships. Thus, this study establishes the utility of using scale analysis as a relatively non-invasive method for inferring growth in salmonids.

Culturally sensitive, preventive antenatal group cognitive-behavioural therapy for Chinese women with depression.

Postnatal depression (PND) affects 10-15% of postnatal women worldwide, yet it is poorly recognized and managed. Among the psychological interventions, which are used to manage PND, cognitive-behavioural therapy was found to be effective and promising. In the past decade, research efforts have focused on developing effective antenatal interventions to prevent PND. Strong antenatal predictors such as antenatal depressive symptoms have been identified for targeted early intervention or prevention to help reduce the risk of developing depression after childbirth. However, the findings regarding effectiveness of antenatal preventive interventions have been inconsistent. Based on the reports of previous studies, a brief group antenatal intervention using cognitive-behavioural approach is necessary, particularly one with sensitivity for Chinese woman. This paper reports the details of a nurse-led cognitive-behavioural programme developed and tested in, and for use with a sample of Hong Kong pregnant women. The trial run showed that the programme was feasible to be implemented and well received by the participants.

Brief repeated virtual nature contact for three weeks boosts university students' nature connectedness and psychological and physiological health during the COVID-19 pandemic: A pilot study.

The COVID-19 pandemic and its associated uncertainties and restrictions have adverse impacts on university students' mental wellbeing. Evidence shows that virtual nature contact has mental health benefits. However, little is known about the potential beneficial health impacts of virtual nature contact during times of social distancing, when access to the natural environment is restricted. This pilot study aimed to examine the effectiveness of a 3-week virtual nature contact in improving nature connectedness and reducing psychophysiological stress. A sample of 56 university students in Hong Kong was randomly assigned to control and nature interventions using 2-D video played for 15 min three times a week for 3 weeks. Nature connectedness, perceived restorativeness and psycho-physiological wellbeing were measured. Our findings show significant changes in psychological stress levels after nature interventions compared with the baseline, including increased happiness and stronger emotions of comfort and relaxation. When compared with the control group, the results show the nature intervention group has significantly higher levels of nature connectedness, happiness, and positive affect, but no significant effects on other psychological and physiological variables (e.g., cardiovascular responses). Our preliminary findings highlight the potential use of virtual nature contacts in bolstering university students' wellbeing at times of pandemic or when in-person visit to the natural environment is not feasible.

Diuraphis noxia and Rhopalosiphum padi (Hemiptera: Aphididae) interactions and their injury on resistant and susceptible cereal seedlings.

Interspecific interactions between the symptomatic (chlorosis-eliciting) Russian wheat aphid, Diuraphis noxia (Mordvilko), and the asymptomatic (nonchlorosis-eliciting) bird cherry-oat aphid, Rhopalosiphum padi (L.), on four cereal genotypes were examined by simultaneous infestations. Four cereals (i.e., Diuraphis noxia-susceptible 'Arapahoe' wheat and 'Morex' barley, and D. noxia-resistant 'Halt' wheat and 'Border' oat) and four infestations (i.e., control, D. noxia, R. padi, and D. noxia/R. padi) were used in the research. Whereas D. noxia biomass confirmed D. noxia resistance among the cereals, R. padi biomass indicated that the D. noxia-resistant cereals did not confer R. padi resistance. D. noxia biomass was significantly lower in D. noxia/R. padi infestation than that in D. noxia infestation on all cereals, except Border oat, which indicated an antagonistic effect of R. padi on D. noxia. All aphid infestations caused a significant plant biomass reduction in comparison with the control. In comparison with D. noxia infestation, D. noxia/R. padi caused a significant plant biomass reduction on all cereals, except Morex barley. Although D. noxia biomass in D. noxia/R. padi infestation was significantly less than that in D. noxia infestation, leaf chlorophyll reduction was the same between D. noxia/R. padi and D. noxia infestations, which suggested that the asymptomatic R. padi enhanced the D. noxia-elicited leaf chlorophyll loss. The regression between chlorophyll content and aphid biomass indicated that the asymptomatic R. padi in the D. noxia/R. padi infestation enhanced chlorophyll loss, but interspecific aphid interaction on plant biomass varied among the cereals.

Identification of Dobrava, Hantaan, Seoul, and Puumala viruses by one-step real-time RT-PCR.

We developed four assays for specifically identifying Dobrava (DOB), Hantaan (HTN), Puumala (PUU), and Seoul (SEO) viruses. The assays are based on the real-time one-step reverse transcriptase polymerase chain reaction (RT-PCR) with the small segment used as the target sequence. The detection limits of DOB, HTN, PUU, and SEO assays were 25, 25, 25, and 12.5 plaque-forming units, respectively. The assays were evaluated in blinded experiments, each with 100 samples that contained Andes, Black Creek Canal, Crimean-Congo hemorrhagic fever, Rift Valley fever and Sin Nombre viruses in addition to DOB, HTN, PUU and SEO viruses. The sensitivity levels of the DOB, HTN, PUU, and SEO assays were 98%, 96%, 92% and 94%, respectively. The specificity of DOB, HTN and SEO assays was 100% and the specificity of the PUU assay was 98%. Because of the high levels of sensitivity, specificity, and reproducibility, we believe that these assays can be useful for diagnosing and differentiating these four Old-World hantaviruses.

Effects of cannabinoid receptor agonists on immunologically induced histamine release from rat peritoneal mast cells.

Immunologic activation of mast cells through the cross-linking of high affinity IgE receptors results in the release of inflammatory mediators which are important in the pathogenesis of allergic reactions. Early studies investigating the effects of palmitoylethanolamide on animal models of inflammation and on rat mast cells led to the hypothesis that endogenous cannabinoids might act as local autacoids which suppressed inflammation by reducing the activation of mast cells. However, more recent studies produced contradicting results. In order to evaluate if cannabinoid receptors are present in mast cells, we studied the effects of endocannabinoids (anandamide and palmitoylethanolamide) and synthetic cannabimimetics (CP 55,940, WIN 55,212-2 and HU-210) on histamine release from rat peritoneal mast cells. When incubated with mast cells alone, only anandamide could induce significant level of histamine release at concentrations higher than 10(-6) M. When mast cells were activated with anti-IgE, the histamine release induced was not affected by anandamide, palmitoylethanolamide and CP 55,940. In contrast, both WIN 55,212-2 and HU-210 enhanced anti-IgE-induced histamine release at 10(-5) M and preincubation did not increase the potency. The histamine releasing action of anandamide and the enhancing effects of WIN 55,212-2 and HU-210 on anti-IgE-induced histamine release were not reduced by the cannabinoid receptor antagonists, AM 281 and AM 630. In conclusion, the present study does not support the hypothesis that cannabinoids suppress mast cell activation. Instead, some of the cannabinoid receptor-directed ligands tested enhanced mast cell activation. However, the high concentrations required and the failure of cannabinoid receptor antagonists to reverse such effects also question the existence of functional cannabinoid receptors in mast cells.

Aphid (Hemiptera: Aphididae) resistance in wheat near-isogenic lines.

Plant and aphid biomass, photosynthetic pigment (chlorophylls a and b and carotenoids) concentrations, and chlorophyll a/b and chlorophyll/carotenoid ratios were quantified in aphid-infested 'Tugela' near-isogenic lines (Tugela, Tugela-Dn1, Tugela-Dn2, and Tugela-Dn5). The objectives were to quantify changes of photosynthetic pigments (chlorophylls a and b, and carotenoids) caused by aphid feeding and assess resistance of wheat isolines through aphid and plant biomass analysis. Biomass of bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae)-infested plants was lower than Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae),- infested plants. When infested by D. noxia, all lines showed increased biomass over time, except Tugela where biomass decreased on day 12. No difference in plant biomass was detected among R. padi-infested and uninfested wheat lines. Biomass of D. noxia from Tugela (D. noxia-susceptible) was significantly higher than from plants with Diuraphis noxia-resistant Dn genes. Diuraphis noxia biomass from Tugela-Dn1 and Dn2 lines was not different from each other, but they were lower than from Tugela-Dn5. In contrast, there was no difference in R. padi biomass among wheat lines. Concentrations of chlorophylls a and b and carotenoids were significantly lower in D. noxia-infested plants compared with R. padi-infested and uninfested plants. When infested by D. noxia, chlorophyll a and b concentrations were not different among wheat lines on day 3, but they were lower in Tugela and Tugela-Dn1 than in Tugela-Dn2 and -Dn5 plants on days 6 and 12. However, no difference was detected in chlorophyll a/b or chlorophyll/carotenoid ratio among Tugela lines. The study demonstrated that Dn genes in the Tugela isolines conferred resistance to D. noxia but not to R. padi. Tugela-Dn1 was antibiotic, Tugela-Dn2 was tolerant and antibiotic, and Tugela-Dn5 was moderately antibiotic.

Enzymatic chlorophyll degradation in wheat near-isogenic lines elicited by cereal aphid (Homoptera: Aphididae) feeding.

Chlorophyll degradation enzyme (i.e., chlorophyllase, Mg-dechelatase, and chlorophyll oxidase) activities of aphid-infested and uninfested 'Tugela' and Tugela near-isogenic wheat lines (i.e., Tugela-Dn1, Tugela-Dn2, and Tugela-Dn5) were assayed. Chlorophyllase activity was higher in bird cherry-oat aphid, Rhopalosiphum padi (L.) (Homoptera: Aphididae),-infested wheat lines compared with Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae)]-infested and uninfested plants. Mg-dechelatase activity was higher in D. noxia-infested wheat lines than in R. padi-infested and uninfested plants. Also, Mg-dechelatase activity was lower in Tugela wheat infested with D. noxia than in Tugela near-isogenic lines with Dn genes. Based on the in vitro assays of chlorophyll degradation enzyme (i.e., chlorophyllase and Mg-dechelatase) activities, we proposed that the chlorotic symptoms observed on D. noxia-infested Tugela wheat were most likely to be elicited by unbalanced chlorophyll biosynthesis and degradation.

Building life-long learning capacity in undergraduate nursing freshmen within an integrative and small group learning context.

BACKGROUND: Life-long learning involves the development of skills in critical thinking (CT), effective group process (GP), and self-directedness (SDL). Recent studies have shown that small group learning with active interactions is effective in enabling students to develop themselves as independent learners beyond graduation. With a view to integrative learning, the purpose of this study was to evaluate life-long learning outcomes through the work of small group teaching and learning for a class of undergraduate nursing freshmen during one academic year. METHODS: A mixed-methods approach was used to evaluate the CT, GP and SDL of 99 freshmen with a self-assessment questionnaire before and after their learning activities in three nursing courses, and to identify themes from a total of six focus group interviews with the students and teachers. RESULTS: The CT, GP and SDL results obtained from self-assessment did not indicate significant differences. Four themes emerged from the qualitative analysis. DISCUSSION: Many factors contributed to the results on life-long learning skill development of students in this study. The qualitative analysis provided good insights for future teaching and learning development. CONCLUSIONS: With a developmental perspective, life-long learning may be better developed and evaluated over a longer period of time in the nursing program.

Group antenatal intervention to reduce perinatal stress and depressive symptoms related to intergenerational conflicts: a randomized controlled trial.

BACKGROUND: Intergenerational conflicts are a major source of stress, which might lead to depression in new mothers. The conflict is heightened when grandparents are involved in childcare. OBJECTIVES: To examine the effectiveness of an interpersonal psychotherapy oriented group intervention to reduce stress and depressive symptoms in new mothers and enhance happiness and self-efficacy in managing intergenerational conflict in childcare. This study is one of the intervention projects of FAMILY: A Jockey Club Initiative for a Harmonious Society, funded by The Hong Kong Jockey Club Charities Trust. DESIGN: Multisite randomized controlled trial with two arms: an intervention group attended an additional 4-week program and a control group who received usual care only. SETTING: Six Maternal and Child Health Centres in Hong Kong PARTICIPANTS: From September 2009 to January 2010, 156 pregnant women who would have grandparents involved in childcare were recruited at their 14-32 weeks' gestation. METHODS: Participants were randomized to groups using computer generated random sequences by blinded recruitment staff. Primary outcomes were stress and depressive symptoms immediately after the intervention and 6-8 weeks after delivery. Secondary outcomes were happiness and self-efficacy in managing conflict. RESULTS: After screening 2870 pregnant women, 156 eligible participants were randomized. Intention-to-treat analysis showed that the intervention group (n=78) had significantly lower perceived stress (p=0.017; Cohen d=0.38) and greater happiness (p=0.004; Cohen d=0.41) than the control group (n=78) immediately after the intervention. However, the effects were not sustained at postnatal follow-up. Subgroup analysis showed that participants with depressive symptoms (EPDS>12) at baseline reported significantly lower stress, greater happiness (p=0.035 and 0.037, respectively; both Cohen d=0.61), greater self-efficacy in managing conflict (p=0.012; Cohen d=0.76) than the control group after the intervention. Also, after delivery, they had significantly greater self-efficacy in managing conflict (p=0.025; Cohen d=0.61) and more able to cooperate with grandparents in childcare (p=0.046; Cohen d=0.59) than the control group. CONCLUSION: The intervention was effective in reducing stress and enhancing happiness among new mothers, particularly those with higher EPDS scores. Postnatal follow-up contacts as booster interventions may be needed to achieve lasting effects of the intervention.

The application of family-nursing assessment skills: from classroom to hospital ward among final-year nursing undergraduates in Hong Kong.

BACKGROUND: There is little research on nursing students' application of family health assessment in clinical practice. OBJECTIVE: To examine the effect of an elective course, Family in Health and Illness (FHI), on year 4 nursing students' family health assessment and practice. METHODS: A quasi-experimental design was used. One hundred and twenty students completed pre- and post-course questionnaires, after taking FHI (n=49) or a course in Women's Health (WH; n=71) in a baccalaureate nursing program in Hong Kong. Students rated their interest in family assessment and appraised their own confidence and competence in practicing family nursing before the courses commenced, immediately after, and three months post course completion. In addition, their perceived ease of applying family assessment in practice was measured. RESULTS: Students who had taken FHI reported significantly higher interest than those who had not immediately after the course and three months later. The perceived ease of functional assessment immediate after the course was the only predictor of confidence and competence in practicing family nursing (B=0.76, 95% CI=1.37-8.23, p=0.011) at the 3-month follow-up after controlling for age and baseline measures. Level of interest (B=0.44, 95% CI=4.55-0.13, p=0.040) was an additional predictor of nurse-patient relationship at the 3-month follow-up. CONCLUSION: Educational input to nursing students may foster their interest and confidence in working with families in clinical settings. Further studies are needed to examine the factors impeding actual application of family nursing assessment.

Physical activity for cancer survivors: 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.

A brief cognitive-behavioral stress management program for secondary school teachers.

OBJECTIVE: This study aimed to assess the efficacy of a brief cognitive-behavioral program that was designed to reduce the work-related stress levels of secondary school teachers. METHODS: A quasi-experimental design was used to compare the intervention groups with the wait-list control groups. Seventy teachers from the intervention groups and 54 from the control groups completed a set of validated scales at the baseline and 3-4 wk later. The scales included the Depression Anxiety Stress Scale, the Dysfunctional Attitude Scale-Form A, the Health-Promoting Lifestyle Profile II, and the Occupational Stress Inventory Revised Edition. RESULTS: After controlling for the baseline measures, the intervention groups had significantly lower role stress, personal strain and overall work-related stress 3-4 wk after the baseline measurements. The intervention groups also had significantly higher stress management behaviors, and less general stress and dysfunctional thoughts than the control groups (all p≤0.05). The levels of dysfunctional thoughts and stress management behaviors significantly predicted general stress after intervention and personal resource deficits. The level of dysfunctional thoughts also predicted the personal strain of work-related stresses (all p<0.05). CONCLUSIONS: The brief program reported in this study was efficacious in reducing the work-related stress of secondary teachers. Teachers experienced less work-related stress after the program, and they reported reduced dysfunctional thoughts and enhanced stress management behaviors. This program may be considered as an initial strategy for teachers to develop skills to cope with their work-related stress in the short term and could be incorporated with other strategies to achieve longer-term effects.

The association between adolescents' depressive symptoms, maternal negative affect, and family relationships in Hong Kong: cross-sectional and longitudinal findings.

This study investigated the bidirectional relationships of adolescents' and maternal mood, and the moderating effect by gender and perceived family relationships on these relationships. Data were obtained from 626 adolescent-mother dyads and follow-up data were collected one year later from a subset. Adolescents reported their depressive symptoms, and their mothers reported their negative affect. Adolescents described their perception of family relationships. Maternal negative affect and adolescents' depressive symptoms were significantly correlated at baseline. This association was moderated by gender and family relationships. The association was stronger in mother-daughter compared to mother-son dyads. In families where relationships were reported to be poor, adolescent depressive symptoms were uniformly high, regardless of maternal negative affect. However, in families where relationships were good, maternal negative affect was associated with higher adolescents' depressive symptoms. In longitudinal analyses, adolescents' mood at baseline was found to relate to maternal negative affect at follow-up. Family relationships at baseline were also associated with adolescents' depressive symptoms at follow-up. However, there was no prediction from maternal negative affect at baseline to adolescents' depressive symptoms at follow-up. Gender and quality of family relationships did not moderate the longitudinal relationships between adolescents' depressive symptoms and maternal negative affect in either direction.

Predictors of maternal responsiveness.

PURPOSE: To explore maternal responsiveness in the first 2 to 4 months after delivery and to evaluate potential predictors of maternal responsiveness, including infant feeding, maternal characteristics, and demographic factors such as age, socioeconomic status, and educational level. DESIGN AND METHODS: A cross-sectional survey design was used to assess the variables of maternal responsiveness, feeding patterns, and maternal characteristics in a convenience sample of 177 mothers in the first 2 to 4 months after delivery. The 60-item self-report instrument included scales to measure maternal responsiveness, self-esteem, and satisfaction with life as well as infant feeding questions and sociodemographic items. An online data-collection strategy was used, resulting in participants from 41 U.S. states. FINDINGS: Multiple regression analysis showed that satisfaction with life, self-esteem, and number of children, but not breastfeeding, explained a significant portion of the variance in self-reported maternal responsiveness scores. In this analysis, sociodemographic variables such as age, education, income, and work status showed little or no relationship to maternal responsiveness scores. CONCLUSIONS: This study provides additional information about patterns of maternal behavior in the transition to motherhood and some of the variables that influence that transition. Satisfaction with life was a new predictor of maternal responsiveness. However, with only 15% of the variance explained by the predictors in this study, a large portion of the variance in maternal responsiveness remains unexplained. Further research in this area is needed.

Advancing normal birth: organizations, goals, and research.

In this column, the support for advancing normal birth is summarized, based on a comparison of the goals of Healthy People 2010, Lamaze International, the Coalition for Improving Maternity Services, and the midwifery model of care. Research abstracts are presented to provide evidence that the midwifery model of care safely and economically advances normal birth. Rates of intervention experienced, as reported in the Listening to Mothers survey, are compared to the forms of care recommended by the Cochrane Database of Systematic Reviews. Implications for perinatal education are addressed.

Postpartum depression and related psychosocial variables in Hong Kong Chinese women: findings from a prospective study.

Research on predictors of postpartum depression (PPD) in Hong Kong (HK) Chinese women is scant. A prospective study with 385 HK Chinese postpartum women was conducted to identify correlations between PPD and demographic variables, and antenatal depression and psychosocial variables, and to determine which of these variables were predictors of PPD. Using the Edinburgh Postnatal Depression Scale (EPDS), we classified 19.8% of participants as postnatally depressed. Fifty-six percent of the variance in PPD was explained by social support and stress factors. However, social support factors accounted for only a small percentage of that variance. The major predictors were antenatal depression, postnatal perceived stress, and childcare stress. HK women may benefit from a culturally appropriate intervention focused on reducing stress in the postpartum period.

The impact of work-related risk on nurses during the SARS outbreak in Hong Kong.

Severe acute respiratory syndrome (SARS) is a highly infectious disease, with high potential for transmission to close contacts, particularly among healthcare workers. This is the first systematic study investigating hospital nurses' physical and psychological health status and the kinds of healthcare used-stratified by the level of contact with SARS patients-during the 2003 outbreak in Hong Kong. Nurses in moderate-risk areas appeared to have more stress symptoms than those working in high-risk areas. It is essential to design hospital support systems and occupational health policy to promote the psychological well-being of nurses during future outbreaks of emerging infections.

Dancing with the one who "brung" you into perinatal education.

The childbirth education movement began with creating a cultural shift to foster understanding that women should have choice in their birth. It has moved to the perinatal education movement with recognition that there are many teachable perinatal moments.