The effect of aged litter materials on polyatomic ion concentrations in fractionated suspended particulate matter from a broiler house.

UNLABELLED: Inorganic emissions from livestock production and subsequent deposition of these ions can be a major source of pollution, causing nitrogen enrichment, eutrophication, acidification of soils and surface waters, and aerosol formation. In the poultry house, ammonia and hydrogen sulfide emissions can also adversely affect the health, performance, and welfare of both animals and human operators. The persistence and long life expectancy of ammonia, odors and toxic pollutants from poultry houses may be due to the ability of suspended particulate matter (SPM) to serve as carriers for odorous compounds such as ammonium ions and other inorganic compounds (e.g., phosphate, sulfate, nitrate, etc.). SPM is generated from the feed, animal manure, and the birds themselves. A large portion of odor associated with exhaust air from poultry houses is SPM that has absorbed odors from within the houses. Understanding the fate and transport processes of ammonia and other inorganic emissions in poultry houses is a necessary first step in utilizing the appropriate abatement strategies. In this study, the examination and characterization of ammonium ions, major components of odors and toxic gases from poultry operations, and other ions in suspended particulate matter in a broiler house were carried out using particle trap impactors. The SPM from the particle trap impactors was extracted and analyzed for its ionic species using ion chromatography (IC). The results showed concentrations of polyatomic ions in suspended particulate matter were found to increase with successive flocks and were highly concentrated in the larger size particulate matter. In addition, the ions concentrations appeared to reach a maximum at the middle of flock age (around the fourth week), tapering off toward the end in a given flock (possibly due to ventilation rates to cool off larger birds). Thus, it can be inferred that aged of bedding materials affects the ionic concentrations in aerosol particulate matter more than the age of the birds. IMPLICATIONS: In the poultry house, toxic gas emissions can adversely affect the health, performance, and welfare of both animals and human operators. The persistence of these toxic pollutants from poultry houses may be due to the ability of suspended particulate matter (SPM) to serve as carriers for these compounds (inorganic ions). Our study showed that polyatomic ions in suspended particulate matter were found to increase with successive flocks and were highly concentrated in the larger size SPM. Understanding the effect of management practices on poultry air emissions will lead to innovative best management practices to safeguard the health and welfare of the animals as well as those of the poultry operators, along with reducing the impact of potential air pollution on the environment.

The Dunedin Multidisciplinary Health and Development Study: overview of the first 40 years, with an eye to the future.

The Dunedin Multidisciplinary Health and Development Study began more than four decades ago. Unusual at the time, it was founded as a multidisciplinary research enterprise, and was strongly supported by the Dunedin community, both professional and lay, in its early years. Seven research themes have evolved over the past 40 years focusing on mental health and neuro-cognition, cardiovascular risk, respiratory health, oral health, sexual and reproductive health, and psychosocial functioning. A seventh, more applied theme, seeks to maximise the value of the Study findings for New Zealand's indigenous people-Maori (or tangata whenua transl people of the land). The study has published over 1200 papers and reports to date, with almost 2/3 of these being in peer-reviewed journals. Here we provide an overview of the study, its history, leadership structure, scientific approach, operational foci, and some recent examples of work that illustrate the following: (a) the value of multidisciplinary data; (b) how the study is well positioned to address contemporary issues; and (c) how research can simultaneously address multiple audiences-from researchers and theoreticians to policy makers and practitioners. Near-future research plans are described, and we end by reflecting upon the core aspects of the study that portend future useful contributions.

Pacific Islands Families: First Two Years of Life Study--design and methodology.

AIMS: Knowledge about the health, psychosocial, and behavioural characteristics of Pacific peoples with young children resident in New Zealand is limited. The Pacific Islands Families: First Two Years of Life (PIF) Study was designed to redress this knowledge gap. This paper describes the design and methodology of the PIF Study. METHODS: Mothers of Pacific infants born at Middlemore Hospital between 15 March and 17 December 2000 were recruited. Maternal home interviews covering sociodemographic, cultural, environmental, child development, family and household dynamics, childcare, lifestyle, and health issues were undertaken at approximately 6-weeks, 12-months, and 24-months postpartum. Paternal home interviews and child development assessments were conducted at approximately 12-months and 24-months postpartum. Information from Middlemore's Hospital Discharge Summary records and Plunket's 6-week and 6-month assessments was also captured. RESULTS: 1708 mothers were identified, 1657 were invited to participate, 1590 (96%) consented to a home visit; and, of these, 1,477 (93%) were eligible for the PIF study. Of those eligible, 1,376 (93%) participated at 6-weeks, 1224 (83%) participated at 12-months, and 1144 (77%) participated at 24-months. No important differential attrition was observed. Paternal interviews and child assessments were conducted on 825 fathers and 1241 infants at 12-months and on 757 fathers and 1064 children at 24-months. CONCLUSIONS: The PIF study is a large, scientifically and culturally robust longitudinal study that has achieved respectable participation rates in a historically hard-to-reach population. We believe that results from this study will inform future policy development within New Zealand.

Intergenerational transmission of warm-sensitive-stimulating parenting: a prospective study of mothers and fathers of 3-year-olds.

More than 200 New Zealand men and women studied repeatedly since age 3 were videotaped interacting with their own 3-year-old children to determine (a) whether childrearing and family climate experienced in 3 distinct developmental periods while growing up (i.e., early childhood, middle childhood, early adolescence) predicted parenting and (b) whether romantic relationship quality moderated the effect of childrearing history on observed parenting. Support for the first hypothesis emerged across all 3 developmental periods for mothers (only), with no evidence of moderating effects of romantic relationship quality for mothers or fathers. Results are discussed in terms of supportive versus harsh parenting, mother-father differences, and the characteristics of the sample.

Adolescents' intentions to smoke as a predictor of smoking.

BACKGROUND: Adolescents' intentions to smoke are generally regarded as a valid and reliable predictor of subsequent smoking. This association is largely based on research with adults and needs a more detailed analysis for adolescents. METHODS: Data on intentions and smoking status were collected as part of a longitudinal, birth-cohort study when the study members were 9, 11, 13, 15, 18, and 21 years of age. RESULTS: The results showed that intention to smoke only had an important predictive power in the subgroup of previous nonsmokers. Among those already smoking (on a monthly basis or greater), previous level of smoking was a more important predictor of future behavior than intention to smoke. In addition, the effect of positive intention to smoke was nonlinear over age and had the greatest effect at age 15. CONCLUSION: The results indicated that in adolescence, measurement of intentions to smoke or not smoke cannot be assumed to be a general predictor of behavior at a later age for all groups of adolescents.

Intergenerational relationships in young adulthood and their life course, mental health, and personality correlates.

To evaluate effects of life-course events and experiences of young adults, as well as personality and mental-health history on intergenerational relationships in young adulthood, the authors examined dyadic relationship data drawn from a sample of more than 900 New Zealand 26-year-olds and their mothers and fathers. Results indicated that intergenerational relations were more positive when young adults were childless, not unemployed, married, and living away from home, but these factors did not interact with family relationship history in predicting relationship outcomes. Intergenerational relationships were less positive when children scored low on positive emotionality and constraint and high on negative emotionality and mental disorders, though these attributes did not account for the effect of life-course factors. Results are discussed in terms of the openness of the parent-child relationship in adulthood to further development.

A longitudinal, population-based, cohort study of childhood asthma followed to adulthood.

BACKGROUND: The outcome of childhood asthma in adults has been described in high-risk cohorts, but few population-based studies have reported the risk factors for persistence and relapse. METHODS: We assessed children born from April 1972 through March 1973 in Dunedin, New Zealand, repeatedly from 9 to 26 years of age with questionnaires, pulmonary-function tests, bronchial-challenge testing, and allergy testing. RESULTS: By the age of 26 years, 51.4 percent of 613 study members with complete respiratory data had reported wheezing at more than one assessment. Eighty-nine study members (14.5 percent) had wheezing that persisted from childhood to 26 years of age, whereas 168 (27.4 percent) had remission, but 76 (12.4 percent) subsequently relapsed by the age of 26. Sensitization to house dust mites predicted the persistence of wheezing (odds ratio, 2.41; P=0.001) and relapse (odds ratio, 2.18; P=0.01), as did airway hyperresponsiveness (odds ratio for persistence, 3.00; P<0.001; odds ratio for relapse, 3.03; P<0.001). Female sex predicted the persistence of wheezing (odds ratio, 1.71; P=0.03), as did smoking at the age of 21 years (odds ratio, 1.84; P=0.01). The earlier the age at onset, the greater the risk of relapse (odds ratio, 0.89 per year of increase in the age at onset; P<0.001). Pulmonary function was consistently lower in those with persistent wheezing than in those without persistent wheezing. CONCLUSIONS: In an unselected birth cohort, more than one in four children had wheezing that persisted from childhood to adulthood or that relapsed after remission. The factors predicting persistence or relapse were sensitization to house dust mites, airway hyperresponsiveness, female sex, smoking, and early age at onset. These findings, together with persistently low lung function, suggest that outcomes in adult asthma may be determined primarily in early childhood.

Gender bias in IQ-discrepancy and post-discrepancy definitions of reading disability.

The present study investigated the hypothesis that the higher prevalence of reading disability (RD) often observed among boys is partly an artifact of gender bias in the prediction of reading from IQ. The relevant regression statistics derived from a sample of more than 900 children revealed a statistically significant intercept bias. Predicted reading scores for boys were systematically overestimated, thereby inflating IQ-reading discrepancies; the converse was found for girls. When defined separately for girls and boys, severe underachievement in reading was found to be equally prevalent in both genders and, furthermore, was associated with qualitatively and quantitatively similar patterns of deficits. Because the bias arose from general differences between boys and girls in reading score distributions (a lower mean and greater variance for boys) rather than from differences in IQ scores, gender bias poses a potential threat not only to traditional IQ-discrepancy definitions but also to post-discrepancy definitions that are based solely on reading score cutoffs. Future classification criteria for RD need to take heed of the possibility that when the distributions of reading scores for boys and girls are not identical, performance cutoffs designating low achievement that are based on data pooled from both genders are likely to result in the overidentification of boys with RD and the underidentification of girls with RD.