A systematic review of methods for increasing vegetable consumption in early childhood

PURPOSE OF REVIEW: This study aims to synthesise the body of research investigating methods for increasing vegetable consumption in 2- to 5-year-old children, while offering advice for practitioners. RECENT FINDINGS: Repeated exposure is a well-supported method for increasing vegetable consumption in early childhood and may be enhanced with the inclusion of non-food rewards to incentivise tasting. Peer models appear particularly effective for increasing 2-5-year-olds' vegetable consumption. There is little evidence for the effectiveness of food adaptations (e.g. flavour-nutrient learning) for increasing general vegetable intake among this age group, although they show some promise with bitter vegetables. SUMMARY: This review suggests that practitioners may want to focus their advice to parents around strategies such as repeated exposure, as well as the potential benefits of modelling and incentivising tasting with non-food rewards. Intervention duration varies greatly, and considerations need to be made for how this impacts on success

Noninvasive assessment of asthma severity using pulse oximeter plethysmograph estimate of pulsus paradoxus physiology

<p>Abstract</p> <p>Background</p> <p>Pulsus paradoxus estimated by dynamic change in area under the oximeter plethysmograph waveform (PEP) might provide a measure of acute asthma severity. Our primary objective was to determine how well PEP correlates with forced expiratory volume in 1-second (%FEV₁) (criterion validity) and change of %FEV₁(responsiveness) during treatment in pediatric patients with acute asthma exacerbations.</p> <p>Methods</p> <p>We prospectively studied subjects 5 to 17 years of age with asthma exacerbations. PEP, %FEV₁, airway resistance and accessory muscle use were recorded at baseline and at 2 and 4 hours after initiation of corticosteroid and bronchodilator treatments. Statistical associations were tested with Pearson or Spearman rank correlations, logistic regression using generalized estimating equations, or Wilcoxon rank sum tests.</p> <p>Results</p> <p>We studied 219 subjects (median age 9 years; male 62%; African-American 56%). Correlation of PEP with %FEV₁demonstrated criterion validity (r = - 0.44, 95% confidence interval [CI], - 0.56 to - 0.30) and responsiveness at 2 hours (r = - 0.31, 95% CI, - 0.50 to - 0.09) and 4 hours (r = - 0.38, 95% CI, - 0.62 to - 0.07). PEP also correlated with airway resistance at baseline (r = 0.28 for ages 5 to 10; r = 0.45 for ages 10 to 17), but not with change over time. PEP was associated with accessory muscle use (OR 1.16, 95% CI, 1.11 to 1.21, P < 0.0001).</p> <p>Conclusions</p> <p>PEP demonstrates criterion validity and responsiveness in correlations with %FEV₁. PEP correlates with airway resistance at baseline and is associated with accessory muscle use at baseline and at 2 and 4 hours after initiation of treatment. Incorporation of this technology into contemporary pulse oximeters may provide clinicians improved parameters with which to make clinical assessments of asthma severity and response to treatment, particularly in patients who cannot perform spirometry because of young age or severity of illness. It might also allow for earlier recognition and improved management of other disorders leading to elevated pulsus paradoxus.</p

Structure and Dynamics of the G121V Dihydrofolate Reductase Mutant: Lessons from a Transition-State Inhibitor Complex

It is well known that enzyme flexibility is critical for function. This is due to the observation that the rates of intramolecular enzyme motions are often matched to the rates of intermolecular events such as substrate binding and product release. Beyond this role in progression through the reaction cycle, it has been suggested that enzyme dynamics may also promote the chemical step itself. Dihydrofolate reductase (DHFR) is a model enzyme for which dynamics have been proposed to aid in both substrate flux and catalysis. The G121V mutant of DHFR is a well studied form that exhibits a severe reduction in the rate of hydride transfer yet there remains dispute as to whether this defect is caused by altered structure, dynamics, or both. Here we address this by presenting an NMR study of the G121V mutant bound to reduced cofactor and the transition state inhibitor, methotrexate. NMR chemical shift markers demonstrate that this form predominantly adopts the closed conformation thereby allowing us to provide the first glimpse into the dynamics of a catalytically relevant complex. Based on 15N and 2H NMR spin relaxation, we find that the mutant complex has modest changes in ps-ns flexibility with most affected residues residing in the distal adenosine binding domain rather than the active site. Thus, aberrant ps-ns dynamics are likely not the main contributor to the decreased catalytic rate. The most dramatic effect of the mutation involves changes in µs-ms dynamics of the F-G and Met20 loops. Whereas loop motion is quenched in the wild type transition state inhibitor complex, the F-G and Met20 loops undergo excursions from the closed conformation in the mutant complex. These excursions serve to decrease the population of conformers having the correct active site configuration, thus providing an explanation for the G121V catalytic defect

Sediment geochemistry of streams draining abandoned lead / zinc mines in central Wales: the Afon Twymyn

Purpose Despite the decline of metal mining in the UK during the early 20th century, a substantial legacy of heavy metal contamination persists in river channel and floodplain sediments. Poor sediment quality is likely to impede the achievement of ’good’ chemical and ecological status for surface waters under the European Union Water Framework Directive. This paper examines the environmental legacy of the Dylife lead/zinc mine in the central Wales mining district. Leachable heavy metal concentrations in the bed sediments of the Afon Twymyn are established and the geochemical partitioning, potential mobility and bioavailability of sediment-associated heavy metals are established. Materials and methods Sediment samples were collected from the river bed and dry-sieved into two size fractions (<63 μm and 64–2,000 μm). The fractionated samples were then subjected to a sequential extraction procedure to isolate heavy metals (Pb, Zn, Cu, Cd, Fe, Mn) in three different geochemical phases. Sediment samples were then analysed for heavy metals using ICP-AES. Results and discussion The bed sediment of the Afon Twymyn is grossly polluted with heavy metals. Within the vicinity of the former mine, Pb concentrations are up to 100 times greater than levels reported to have deleterious impacts on aquatic ecology. Most heavy metals exist in the most mobile easily exchangeable and carbonate-bound geochemical phases, potentially posing serious threats to ecological integrity and constituting a significant, secondary, diffuse source of pollution. Metal concentrations decrease sharply downstream of the former mine, although there is a gradual increase in the proportion of readily extractable Zn and Cd. Conclusions Implementation of sediment quality guidelines is important in order to achieve the aims of the Water Framework Directive. Assessments of sediment quality should include measurements of background metal concentrations, river water physico-chemistry and, most importantly, metal mobility and potential bioavailability. Uniformity of sediment guidelines throughout Europe and flexibility of targets with regard to the most heavily contaminated mine sites are recommended

A Novel Pathogenicity Gene Is Required in the Rice Blast Fungus to Suppress the Basal Defenses of the Host

For successful colonization and further reproduction in host plants, pathogens need to overcome the innate defenses of the plant. We demonstrate that a novel pathogenicity gene, DES1, in Magnaporthe oryzae regulates counter-defenses against host basal resistance. The DES1 gene was identified by screening for pathogenicity-defective mutants in a T-DNA insertional mutant library. Bioinformatic analysis revealed that this gene encodes a serine-rich protein that has unknown biochemical properties, and its homologs are strictly conserved in filamentous Ascomycetes. Targeted gene deletion of DES1 had no apparent effect on developmental morphogenesis, including vegetative growth, conidial germination, appressorium formation, and appressorium-mediated penetration. Conidial size of the mutant became smaller than that of the wild type, but the mutant displayed no defects on cell wall integrity. The Δdes1 mutant was hypersensitive to exogenous oxidative stress and the activity and transcription level of extracellular enzymes including peroxidases and laccases were severely decreased in the mutant. In addition, ferrous ion leakage was observed in the Δdes1 mutant. In the interaction with a susceptible rice cultivar, rice cells inoculated with the Δdes1 mutant exhibited strong defense responses accompanied by brown granules in primary infected cells, the accumulation of reactive oxygen species (ROS), the generation of autofluorescent materials, and PR gene induction in neighboring tissues. The Δdes1 mutant displayed a significant reduction in infectious hyphal extension, which caused a decrease in pathogenicity. Notably, the suppression of ROS generation by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases, resulted in a significant reduction in the defense responses in plant tissues challenged with the Δdes1 mutant. Furthermore, the Δdes1 mutant recovered its normal infectious growth in DPI-treated plant tissues. These results suggest that DES1 functions as a novel pathogenicity gene that regulates the activity of fungal proteins, compromising ROS-mediated plant defense

Public health campaigns and obesity - a critique

<p>Abstract</p> <p>Background</p> <p>Controlling obesity has become one of the highest priorities for public health practitioners in developed countries. In the absence of safe, effective and widely accessible high-risk approaches (e.g. drugs and surgery) attention has focussed on community-based approaches and social marketing campaigns as the most appropriate form of intervention. However there is limited evidence in support of substantial effectiveness of such interventions.</p> <p>Discussion</p> <p>To date there is little evidence that community-based interventions and social marketing campaigns specifically targeting obesity provide substantial or lasting benefit. Concerns have been raised about potential negative effects created by a focus of these interventions on body shape and size, and of the associated media targeting of obesity.</p> <p>Summary</p> <p>A more appropriate strategy would be to enact high-level policy and legislative changes to alter the obesogenic environments in which we live by providing incentives for healthy eating and increased levels of physical activity. Research is also needed to improve treatments available for individuals already obese.</p