Early childhood healthy and obese weight status: potentially protective benefits of breastfeeding and delaying solid foods.

The aim of this study was to assess the relationship between breastfeeding and postponing introduction to solid food (SF) on children's obesity and healthy weight status (WS), at 2 and 4 years. Drawing upon a nationally representative sample of children from the Early Childhood Longitudinal Study-Birth Cohort, we estimated the magnitude of the relationship between children's WS and early feeding practices. Contingency tables and multinomial logistic regression were used to analyze obese and healthy WS for breastfed and never breastfed children and examine three timing categories for SF introduction. With both percentages and odds, breastfeeding and delaying introduction to SF until 4 months were associated with lower obesity rates and higher, healthy WS rates (typically 5-10%). Analyses of feeding practice combinations revealed that when children were not breastfed, obesity odds decreased when SF introduction was postponed until 4 months. Obesity odds were further reduced when SF delay was combined with breastfeeding. Consistent increases in healthy WS were also observed. Benefits were stable across both follow-up periods. Breastfeeding and delaying complementary foods yielded consistently and substantially lower likelihood of obesity and greater probability of healthy WS. Health policies targeting early feeding practices represent promising interventions to decrease preschool obesity and promote healthy WS.

Distribution patterns of epiphytic reed-associated macroinvertebrate communities across European shallow lakes.

So far, research on plant-associated macroinvertebrates, even if conducted on a large number of water bodies, has mostly focused on a relatively small area, permitting limited conclusions to be drawn regarding potentially broader geographic effects, including climate. Some recent studies have shown that the composition of epiphytic communities may differ considerably among climatic zones. To assess this phenomenon, we studied macroinvertebrates associated with the common reed Phragmites australis (Cav.) Trin. ex Steud in 46 shallow lakes using a common protocol. The lakes, located in nine countries, covered almost the entire European latitudinal range (from <48°N to 61°N) and captured much of the variability in lake size and nutrient content in the region. A Poisson Generalized Linear Mixed Model (GLMM) showed the number of macroinvertebrate epiphytic taxa to be negatively associated with water conductivity and positively associated with medium ice cover duration (approximately 1 month). A Gamma GLMM showed a positive effect of chlorophyll a on the density of macroinvertebrates, and a significantly greater density in lakes located at the lowest and highest latitudes. Individual taxa responded differently to lake environmental conditions across climate zones. Chironomidae dominated in all climate zones, but their contribution to total density decreased with increasing latitude, with progressively greater proportions of Naidinae, Asellidae, Ephemeroptera and Trichoptera. Our study demonstrates that epiphytic macroinvertebrate fauna, even when analyzed at low taxonomic resolution, exhibits clear differences in diversity, relative abundance of individual taxa and total density, shaped both by geographic and anthropogenic variables. The results were discussed in the context of climate change. To our best knowledge this is the first study to examine epiphytic fauna carried out on a European scale.

The Water Framework Directive: total environment or political compromise?

The European Water Framework Directive (2000/60/EC) is potentially ground-breaking legislation. It seeks to bring about improvement of aquatic habitats in Europe to 'good ecological status', defined as slightly different from 'high ecological status', with no or minimal human impact. The characteristics of pristine ecological status include nutrient parsimony, a defined characteristic structure of the system (including geomorphological structure and hydrology, biological and food web structure) and the connectivity and extent of the system that are essential for resilience to change. This modern ecological understanding is being ignored by government agencies charged with enacting the Directive. Schemes are being devised that measure secondary characteristics of habitats using approaches drawn from traditional water quality management. Typologies, indicated by the Directive to give a geographical basis within which to determine ecological status, are also being corrupted with different typologies used for different determinands. The ecological reality of reasonably distinctive, integrated systems (an erosive upland river versus a floodplain system, for example) is being avoided. Emphasis is being placed on precision of measurement of specific determinands rather than accuracy in what is being measured and proposed schemes are complex and expensive when accurate assessment could be carried out much more cheaply. Many are also likely to become redundant as effects of climate change take hold. The current approach will lead to some improvement in water quality but not to the fundamental change in ecological quality intended by the Directive and has partly been encouraged by lack of definition and contradictions within the Directive itself. Documented details currently available from the UK agencies are used to illustrate how the intentions of the Directive are being undermined for ostensibly political convenience through processes of redefinition and limitation of characteristics measured. There appears to be a parallel concern among official and non-governmental European bodies.

Evaluating Coincident Relationships Between Obesity Incidence and Normal Weight Incidence From Birth Through Kindergarten for US Children.

PURPOSE: We examine the concurrent relationship between obesity incidence and normal weight status incidence and prevalence in children between 9 months and kindergarten. DESIGN: Multistage, probability sample from the Early Childhood Longitudinal Study-Birth cohort. SETTING: United States. PARTICIPANTS: Representative sample of US preschool children (n = 9950) followed from birth through kindergarten. MEASURES: From direct, anthropometric measures, we reported prevalence and incidence rates across 4 follow-up periods. ANALYSIS: In addition to prevalence and incidence rates, we reported risk ratios based on multiple definitions and estimated predicted probabilities of obesity and normal weight status using clinically meaningful body mass index (BMI)-for-age percentiles. RESULTS: Obesity prevalence (13%-20%) was much smaller than normal weight status prevalence (66%-70%). Lower socioeconomic status, Hispanic, and non-Hispanic black children had greater risk of obesity. During 9 months to kindergarten, obesity incidence decreased two-thirds (15.6%), while normal weight status incidence decreased almost one-half (44.6%). Coincidently, normal weight status incidence (ranged from 23% to 45%) was consistently and substantially higher than obesity incidence (ranged from 5% to 15%). During 4 years to kindergarten, the obesity risk for overweight children was 13 times higher than that for normal weight status children. CONCLUSION: Overall rates of obese and normal weight incidence were substantial at 9 months, trended lower, but remained high through kindergarten. At 4 years to kindergarten, children with relatively high initial BMI were very likely to become obese but far less likely to achieve normal weight status.

Identification of the neuroprotective molecular region of pigment epithelium-derived factor and its binding sites on motor neurons.

Pigment epithelium-derived factor (PEDF), a member of the serine protease inhibitor (serpin) family, is a survival factor for various types of neurons. We studied the mechanisms by which human PEDF protects motor neurons from degeneration, with the goal of eventually conducting human clinical trials. We first searched for a molecular region of human PEDF essential to motor neuron protection. Using a spinal cord culture model of chronic glutamate toxicity, we show herein that a synthetic 44 mer peptide from an N-terminal region of the human PEDF molecule that lacks the homologous serpin-reactive region contains its full neuroprotective activity. We also investigated the presence and distribution of PEDF receptors in the spinal cord. Using a fluoresceinated PEDF probe, we show that spinal motor neurons contain specific binding sites for PEDF. Kinetics analyses using a radiolabeled PEDF probe demonstrate that purified rat motor neurons contain a single class of saturable and specific binding sites. This study indicates that a small peptide fragment of the human PEDF molecule could be engineered to contain all of its motor neuron protective activity, and that the neuroprotective action is likely to be mediated directly on motor neurons via a single class of PEDF receptors. The data support the pharmacotherapeutic potential of PEDF as a neuroprotectant in human motor neuron degeneration.

Failed Warnings: Evaluating the Impact of Academic Probation Warning Letters on Student Achievement.

BACKGROUND: Academic probation is a nearly universal but underresearched policy practiced at most postsecondary institutions. OBJECTIVES: To evaluate the impact of probation warning letters on students' academic performance. RESEARCH DESIGN: Employing the inferentially strong regression discontinuity design, we evaluated the impact of two versions of warning letters (U.S. mail and email), noting their impact on next semester grades. SUBJECTS: Probation and nonprobation students at a large, Midwestern college enrolled during two, successive fall-winter semester pairs (n > 17,000, for each pair). MEASURES: Fall and winter grade point averages (GPAs) were identified for each individual student in the study sample. RESULTS: Using both parametric and nonparametric analyses, we found that neither delivery method, paper or electronic, had a consistent, significant impact on subsequent GPA or odds of a GPA ≥ 2.0 during the next semester. Four of the eight measures of effect for GPA were small and positive (0.02-0.15; one significant positive outcome), and four were negative (-0.02 to -0.08; one significant negative result). A separate set of analyses that excluded students who took a single course led to further inconsistency in results. Supplementary analyses that excluded students scoring far from the cut-point yielded results consistent with a no-difference conclusion. Our findings also indicated that, after being placed on probation, only a small percentage of students were able to avoid movement to the next stage of academic sanction. CONCLUSIONS: Warning letters notifying students of probation status, lacking a staff-focused intervention, had little impact on academic performance.

Adaptations of epipelic and epipsammic freshwater algae.

Epipelic algae live freely on sediment surfaces, epipsammic algae live attached to grains in sandy sediments. Both groups may be buried by wave action and animal disturbance when they may find themselves in dark, deoxygenated layers. Epipelic algae, though tolerant of darkness for many days do not survive anaerobiosis for long and must rely on rapid movement to regain the sediment surface. Since they often are non-motile epipsammic algae cannot always move rapidly upwards. They tolerate both darkness and anaerobiosis, retaining considerable photosynthetic potential for several days in the complete absence of oxygen.

Increased risk of very low birth weight, rapid postnatal growth, and autism in underweight and obese mothers.

PURPOSE: To determine whether prepregnancy weight was associated with children's birth weight, early physical growth, and autism diagnosis. DESIGN: Early Childhood Longitudinal Study-Birth Cohort data. SETTING: United States. SUBJECTS: Representative sample of U.S. children followed from birth through kindergarten (n = 4800). Also, a subpopulation of the very low birth weight children was examined (n = 500). MEASURES: Maternal variables included age and prepregnancy body mass index. Changes in children's height, weight, and head circumference between 9 months and 2 years were used as growth metrics. Children's sex, age, birth weight, and reported autism were also considered. ANALYSIS: Logistic and multinomial logistic models assessed the impact of prepregnancy weight on birth weight and children's subsequent rate of physical growth and autism. RESULTS: Children born to underweight or obese mothers had increased odds of very low birth weight. Very low birth weight was related to rapid height and weight growth and more than twice the likelihood to subsequently be diagnosed with autism. For the subgroup of very low birth weight children, rapid head growth was related to a fivefold increase in the odds of autism. After accounting for the impact birth weight and growth rates, we found prepregnancy weight indirectly impacted autism risk. CONCLUSION: Being underweight or obese during prepregnancy indirectly increased risk for autism from increased odds of low birth weight and accelerated postnatal growth.

Evaluating effects of developmental education for college students using a regression discontinuity design.

BACKGROUND: Annually, American colleges and universities provide developmental education (DE) to millions of underprepared students; however, evaluation estimates of DE benefits have been mixed. OBJECTIVES: Using a prototypic exemplar of DE, our primary objective was to investigate the utility of a replicative evaluative framework for assessing program effectiveness. RESEARCH DESIGN: Within the context of the regression discontinuity (RD) design, this research examined the effectiveness of a DE program for five, sequential cohorts of first-time college students. Discontinuity estimates were generated for individual terms and cumulatively, across terms. SUBJECTS: Participants were 3,589 first-time community college students. MEASURES: DE program effects were measured by contrasting both college-level English grades and a dichotomous measure of pass/fail, for DE and non-DE students. RESULTS: Parametric and nonparametric estimates of overall effect were positive for continuous and dichotomous measures of achievement (grade and pass/fail). The variability of program effects over time was determined by tracking results within individual terms and cumulatively, across terms. Applying this replication strategy, DE's overall impact was modest (an effect size of approximately .20) but quite consistent, based on parametric and nonparametric estimation approaches. A meta-analysis of five RD results yielded virtually the same estimate as the overall, parametric findings. Subset analysis, though tentative, suggested that males benefited more than females, while academic gains were comparable for different ethnicities. CONCLUSION: The cumulative, within-study comparison, replication approach offers considerable potential for the evaluation of new and existing policies, particularly when effects are relatively small, as is often the case in applied settings.

Cogs in the endless machine: lakes, climate change and nutrient cycles: a review.

Lakes have, rather grandly, been described as sentinels, integrators and regulators of climate change (Williamson et al., Limnol. Oceanogr. 2009; 54: 2273-82). Lakes are also part of the continuum of the water cycle, cogs in a machine that processes water and elements dissolved and suspended in myriad forms. Assessing the changes in the functioning of the cogs and the machine with respect to these substances as climate changes is clearly important, but difficult. Many other human-induced influences, not least eutrophication, that impact on catchment areas and consequently on lakes, have generally complicated the recording of recent change in sediment records and modern sets of data. The least confounded evidence comes from remote lakes in mountain and polar regions and suggests effects of warming that include mobilisation of ions and increased amounts of phosphorus. A cottage industry has arisen in deduction and prediction of the future effects of climate change on lakes, but the results are very general and precision is marred not only by confounding influences but by the complexity of the lake system and the infinite variety of possible future scenarios. A common conclusion, however, is that warming will increase the intensity of symptoms of eutrophication. Direct experimentation, though expensive and still unusual and confined to shallow lake and wetland systems is perhaps the most reliable approach. Results suggest increased symptoms of eutrophication, and changes in ecosystem structure, but in some respects are different from those deduced from comparisons along latitudinal gradients or by inference from knowledge of lake behaviour. Experiments have shown marked increases in community respiration compared with gross photosynthesis in mesocosm systems and it may be that the most significant churnings of these cogs in the earth-air-water machine will be in their influence on the carbon cycle, with possibly large positive feedback effects on warming.

U.S. children's preschool weight status trajectories: patterns from 9-month, 2-year, and 4-year Early Childhood Longitudinal Study-Birth cohort data.

PURPOSE: To track changes in U.S. children's early weight status (normal, at-risk, or obese) from infancy through preschool. DESIGN: Patterns of change in individual children's weight status are established using three time points from the Early Childhood Longitudinal Study-Birth cohort. SETTING: United States. SUBJECTS: Nationally representative sample of U.S. preschool children surveyed at 9 months (n = 8900), with follow-up at 2 years (n = 7500) and preschool (n = 7000). MEASURES: Individual children's weight status was determined from Centers for Disease Control and Prevention growth charts at multiple time periods. ANALYSIS: Layered, categorical data analysis of changes in weight status patterns at three time periods during infancy through preschool. RESULTS: Young children whose early weight status was normal tend to retain a normal weight status and not to develop an unfavorable status (at-risk, obese). In contrast, children who were obese at an early age were more likely to have an at-risk or obese weight category at a later age. Overall, both favorable and unfavorable early weight statuses were highly associated with subsequent status at preschool. CONCLUSION: Early weight status can provide important information relevant for early entry point prevention and treatment of childhood obesity.

Young children's weight trajectories and associated risk factors: results from the Early Childhood Longitudinal Study-Birth Cohort.

PURPOSE: To estimate the prevalence of U.S. children's overweight risk and obesity at age 9 months and at age 2 years, to assess weight changes between the two periods, and to examine relationships between weight status (i.e., normal, at risk, or obese) changes and demographic variables. DESIGN: Analyses of children's early weight trajectories and related demographic characteristics from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B) are presented. SETTING: United States. SUBJECTS: The 9-month-old (n  =  8900) and 2-year-old (n  =  7500) ECLS-B waves were used to generate nationally representative estimates of obese and at-risk children born in 2001. MEASURES: Measures included child's sex, race/ethnicity, socioeconomic status, community locale, geographic region, and weight status. ANALYSIS: Logistic and multinomial logistic regression models were used to determine the odds of children's demographic characteristics being related to weight persistence, loss, or gain. RESULTS: Approximately one-third of U.S. children were either at risk or obese at 9 months (31.9%) and at 2 years (34.3%). Some children were at greater risk (e.g., Hispanics and low socioeconomic status children), while others had reduced risk (e.g., females and Asian/Pacific Islanders). Additional results from two trajectory models generally corroborated patterns of status change due to weight gain. CONCLUSIONS: Between age 9 months and age 2 years, U.S. children consistently moved toward less desirable weight status. Obesity risk was not uniform across demographic subgroups, suggesting that health policy might focus on those children at greatest risk.

Water pollution by agriculture.

Agriculture disrupts all freshwater systems hugely from their pristine states. The former reductionist concept of pollution was of examining individual effects of particular substances on individual taxa or sub-communities in freshwater systems, an essentially ecotoxicological concept. It is now less useful than a more holistic approach that treats the impacts on the system as a whole and includes physical impacts such as drainage and physical modification of river channels and modification of the catchment as well as nutrient, particulate and biocide pollution. The European Water Framework Directive implicitly recognizes this in requiring restoration of water bodies to 'good ecological quality', which is defined as only slightly different from pristine state. The implications for the management of agriculture are far more profound than is currently widely realized.

A rare case of tako-tsubo cardiomyopathy complicated by a left ventricular thrombus.

Tako-tsubo cardiomyopathy is a rare stress-related cardiomyopathy usually seen in postmenopausal women after an emotional stressor. Patients generally present with angina-like substernal chest pain. The electrocardiogram (ECG) shows ST segment elevation or T wave inversions across the anterior precordial leads. Cardiac markers are minimally elevated, without evidence of coronary artery disease on angiography. The ventriculogram demonstrates hypokinesis and ballooning of the apex with hyperkinesis of the base. Prognosis is favorable with normalization of wall motion abnormalities within weeks. We present a rare case tako-tsubo cardiomyopathy complicated by a left ventricular mural thrombus. It is thought that this thrombus may have been precipitated by the ventricular dyskinesis. Further research is needed to determine the true incidence of left ventricular thrombus and the role of short-term anticoagulant therapy in this disorder.