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The current review aimed to synthesise the literature on food literacy interventions among adolescents in secondary schools, the attitudes and perceptions of food literacy interventions in secondary schools, and their effects on dietary outcomes.
The systematic review searched five electronic databases from the earliest record to present.
The studies selected for the review were from sixteen countries: Australia (n 10), Canada (n 1), China (n 1), France (n 1), Greece (n 2), Iran (n 1), South Africa (n 1), South India (n 1), Kenya (n 1), Norway (n 2), Portugal (n 1), Denmark (n 1), Northern Ireland (n 1), USA (n 17), UK (n 1) and Sweden (n 2).
Adolescents aged 10–19 years.
Forty-four studies were eligible for inclusion. Adolescents with greater nutritional knowledge and food skills showed healthier dietary practices. Studies found a mixed association between food literacy and long-term healthy dietary behaviour. Two studies showed an improvement in adolescents’ cooking skills and food safety knowledge; six studies showed an improvement in overall food safety knowledge; six studies showed an improvement in overall food and nutritional knowledge; and two studies showed an improvement in short-term healthy dietary behaviour.
Food literacy interventions conducted in a secondary-school setting have demonstrated a positive impact on healthy food and nutritional knowledge. However, there appears to be limited evidence supporting food literacy interventions and long-term dietary behaviours in adolescents. More evidence-based research is required to adequately measure all domains of food literacy and more age-specific food literacy interventions.
Background: Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord impairment. In a public healthcare system, wait times to see spine specialists and eventually access surgical treatment for CSM can be substantial. The goals of this study were to determine consultation wait times (CWT) and surgical wait times (SWT), and identify predictors of wait time length. Methods: Consecutive patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) prospective and observational CSM study from March 2015 to July 2017 were included. A data-splitting technique was used to develop and internally validate multivariable models of potential predictors. Results: A CSORN query returned 264 CSM patients for CWT. The median was 46 days. There were 31% mild, 35% moderate, and 33% severe CSM. There was a statistically significant difference in median CWT between moderate and severe groups; 207 patients underwent surgical treatment. Median SWT was 42 days. There was a statistically significant difference in SWT between mild/moderate and severe groups. Short symptom duration, less pain, lower BMI, and lower physical component score of SF-12 were predictive of shorter CWT. Only baseline pain and medication duration were predictive of SWT. Both CWT and SWT were shorter compared to a concurrent cohort of lumbar stenosis patients (p <0.001). Conclusions: Patients with shorter duration (either symptoms or medication) and less neck pain waited less to see a spine specialist in Canada and to undergo surgical treatment. This study highlights some of the obstacles to overcome in expedited care for this patient population.
Nitrous oxide (N2O) is a potent greenhouse gas with implication
for climate change. Agriculture accounts for 10% of all greenhouse gas
emissions in the United States, but 75% of the country's N2O
emissions. In the absence of PRE herbicides, weeds compete with soybean for
available soil moisture and inorganic N, and may reduce N2O
emissions relative to a weed-free environment. However, after weeds are
killed with a POST herbicide, the dead weed residues may stimulate
N2O emissions by increasing soil moisture and supplying carbon
and nitrogen to microbial denitrifiers. Wider soybean rows often have more
weed biomass, and as a result, row width may further impact how weeds
influence N2O emissions. To determine this relationship, field
studies were conducted in 2013 and 2014 in Arlington, WI. A two-by-two
factorial treatment structure of weed management (PRE + POST vs. POST-only)
and row width (38 or 76 cm) was arranged in a randomized complete block
design with four replications. N2O fluxes were measured from
static gas sampling chambers at least weekly starting 2 wk after planting
until mid-September, and were compared for the periods before and after weed
termination using a repeated measures analysis. N2O fluxes were
not influenced by the weed by width
interaction or width before termination, after termination,
or for the full duration of the study at P ≤ 0.05. Interestingly, we
observed that POST-only treatments had lower fluxes on the sampling day
immediately prior to POST application (P = 0.0002), but this was the only
incidence where weed influenced N2O fluxes, and
overall, average fluxes from PRE + POST and POST-only treatments were not
different for any period of the study. Soybean yield was not influenced by
width (P = 0.6018) or weed by
width (P = 0.5825), but yield was 650 kg ha−1
higher in the PRE + POST than POST-only treatments (P = 0.0007). These
results indicate that herbicide management strategy does not influence
N2O emissions from soybean, and the use of a PRE herbicide
prevents soybean yield loss.
To assess the association of diet-related practices and BMI with diet quality in rural adults aged ≥74 years.
Cross-sectional. Dietary quality was assessed by the twenty-five-item Dietary Screening Tool (DST). Diet-related practices were self-reported. Multivariate linear regression models were used to analyse associations of DST scores with BMI and diet-related practices after controlling for gender, age, education, smoking and self- v. proxy reporting.
Geisinger Rural Aging Study (GRAS) in Pennsylvania, USA.
A total of 4009 (1722 males, 2287 females; mean age 81·5 years) participants aged ≥74 years.
Individuals with BMI < 18·5 kg/m2 had a significantly lower DST score (mean 55·8, 95 % CI 52·9, 58·7) than those individuals with BMI = 18·5–24·9 kg/m2 (mean 60·7, 95 % CI 60·1, 61·5; P = 0·001). Older adults with higher, more favourable DST scores were significantly more likely to be food sufficient, report eating breakfast, have no chewing difficulties and report no decline in intake in the previous 6 months.
The DST may identify potential targets for improving diet quality in older adults including promotion of healthy BMI, breakfast consumption, improving dentition and identifying strategies to decrease concern about food sufficiency.
The insertion of nanostructured materials (such as quantum wells, wires, and dots) into the intrinsic region of p-i-n solar cells introduces an intermediate band within the bandgap of the host material. It has been shown that the sub-bandgap conversion provided by the nanostructured materials, enhances the short circuit current as well as the overall efficiency of InAs quantum dots (QD) imbedded in GaAs superlattice (SL) solar cells . As a contender for space applications, it is necessary to subject these solar cell structures to temperatures encountered in the Low Earth Orbit (LEO), probing for any material degradation. Herein, we focus on temperature dependent characterization using high resolution X-ray diffraction (HRXRD) of InAs QD enhanced GaAs solar cell structures with varying growth parameters. The structures characterized can be classified into three groups: (1) GaP strain compensation coverage, (2) GaAs barrier coverage, and (3) InAs coverage for QD formation. HRXRD rocking curves of each structure focusing around the GaAs peak are analyzed at a range of temperatures up to 200˚C. Although no noticeable shifts in the SL peaks are detected, interfacial diffusion decreased the resolution of fringes produced by reflections at the SL interfaces in test structures with varying InAs QD coverage. Unbalanced strain in the same structures shows a distortion in the GaAs peaks.
The High Plateaus of Utah include seven separate mountain ranges that supported glaciers during the Pleistocene. The Fish Lake Plateau, located on the eastern edge of the High Plateaus, preserves evidence of at least two glacial advances. Four cosmogenic 3He exposure ages of boulders in an older moraine range from 79 to 159 ka with a mean age of 129 ± 39 ka and oldest ages of 152 ± 3 and 159 ± 5 ka. These ages suggest deposition during the type Bull Lake glaciation and Marine Oxygen Isotope Stage (MIS) 6. Twenty boulder exposure ages from four different younger moraines indicate a local last glacial maximum (LGM) of ~ 21.1 ka, coincident with the type Pinedale glaciation and MIS 2. Reconstructed Pinedale-age glaciers from the Fish Lake Plateau have equilibrium-line altitudes ranging from 2950 to 3190 m. LGM summer temperature depressions for the Fish Lake Plateau range from −10.7 to −8.2°C, assuming no change in precipitation. Comparison of the Fish Lake summer temperature depressions to a regional dataset suggests that the Fish Lake Plateau may have had a slight increase (~ 1.5× modern) in precipitation during the LGM. A series of submerged ridges in Fish Lake were identified during a bathymetric survey and are likely Bull Lake age moraines.
Mutations in the gatB gene as well as mutations in the putative structural gene gatA and the positive acting regulatory gene intA can affect γ-amino-n-butyrate (GABA) transaminase (EC 126.96.36.199) levels in the ascomycete fungus Aspergillus nidulans. Partial or complete loss of function mutations in gatA, gatB and ssuA, which specifies succinic semialdehyde dehydrogenase, can lead to accumulation of ω-amino acids resulting in pseudo-constitutivity and elevated expression of (retained) activities under intA control. These regulatory effects underlie selective methods for gatB−, ssuA− and leaky gatA− mutations. However, all three gatB− alleles which have been selected lead only to partial loss of GABA transaminase activity as judged by both in vivo and in vitro criteria. It has not been established whether the leakiness of these three gatB− mutations is an allele-specific or a locus-specific effect and whether or not the GABA transaminase present in gatB− strains differs from the wild type enzyme. Thus the role of the gatB product remains to be elucidated. The gatB gene is not closely linked to any other gene involved in ω-amino metabolism or related pathways.
Interest in the selection of mutations affecting L-proline catabolism in Aspergillus nidulans is heightened by the involvement of one of the very few examples of a cluster of functionally related genes in an eukaryote and by an increasing awareness of the biological phenomena in which proline and proline catabolism participate. The sasA-60 (semialdehyde sensitive) mutation in A. nidulans results in toxicity of catabolic precursors of L-glutamic γ-semialdehyde (or its internal Schiff base L-Δ1-pyrroline-5-carboxylate) and succinic semialdehyde, apparently without affecting the catabolic pathways concerned. As sasA-60 is unlinked to the prn gene cluster, specifying the gene products necessary for L-proline catabolism and as L-proline, a precursor of L-glutamic γ-semialdehyde, is highly toxic to sasA-60 strains, this forms the basis of a powerful positive selection technique for obtaining a number of types of prn mutations. Many of these prn mutations can be directly classified according to the gene product(s) affected on the basis of growth phenotype with respect to L-arginine and L-ornithine utilization, proline-dependent resistance to certain toxic amino acid analogues and effect on supplementation of proline auxotrophies. The availability of both a positive selection technique and an extensive nutritional screening system has enabled the identification of fourteen spontaneous deletion mutations, recognized as extending into the prnB gene, specifying the principal L-proline permease, and into at least one other prn gene. These deletion mutations have been partially characterized both genetically and biochemically. In particular their use has greatly facilitated fine-structure mapping of the prn cluster and aided studies of the regulation of prn gene expression.
Improving the production of photocurrent in the middle junction of a InGaP/Ga(In)As/Ge triple-junction solar cells (TJSC) can improve the overall conversion efficiency of cell. One possible method to improve the middle junction photocurrent is inserting a quantum dot (QD) superlattice (SL) into the stack. It has been predicted that QD-SL enhanced TJSCs have an efficiency ceiling of 47% under a one-sun AM0 illumination spectrum. Additionally, QD array enhanced GaAs cells have the added benefit of possible intermediate band effects, anisotropic absorption and enhanced radiation tolerance. Embedding InAs quantum dots (QDs) in a single junction GaAs solar cell can increase sub-GaAs bandgap photocurrent generation. This method has been shown to improve the short circuit current density (Jsc) of single junction cells under simulated 1 sun air mass zero (AM0) illumination. However, the increase in strain due to the InAs QD self-assembly may cause defects that reduce the minority carrier lifetime resulting in losses in the cell open circuit voltage (Voc) on the order of 300-500 mV. The introduction of strain compensation (SC) layers into the superlattice (SL) structure of a QD solar cell has previously been shown to improve the device performance, including the partial recovery of Voc. Strain compensation can be used effectively to balance the residual strain, impede dislocation formation, and improve the solar cell characteristics. The effect of GaP strain compensation on the solar cell electrical and material properties was investigated. High resolution X-ray diffraction (HRXRD) scans along the symmetric (004) Bragg peak show weak intensity and wide FWHM at the zero order SL peak (SL0) for non-SC samples. Optimum SC thickness was theoretically determined using a zero in plane stress method and experimentally verified using HRXRD. Optimal strain compensation was then used to increase the QD SL stacking from 5x to 10x and 20x. Use of SC resulted in shifting of the SL0 peak toward the substrate peak as well as reduced FWHM and improved SL peak definition. Kinematical diffraction modeling of the QD structures using numerical simulation indicated this peak shift resulted from reduced overall strain in the SL stack up to 5ML of SC. The material quality improvement in the SC QD solar cells was manifested in an improved spectral response and Jsc. The optoelectronic results for GaAs solar cells with QD SL’s demonstrate a strong dependence on GaP SC layer thickness. In addition, comparison of multi junction (MJ) solar cells which incorporate the SC QD SL’s demonstrate the utility of additional sub-GaAs bandgap current contribution as a tool for additional current-matching optimization in MJ solar cells.
The effects of strain within stacked layers of InAs quantum dots (QDs) were investigated. InAs QD test structures with and without strain compensation (SC) were analyzed using atomic force microscopy, transmission electron microscopy, and X-ray diffraction. The affects of strain compensation on test structure morphology and on GaAs-based QD solar cell performance was studied as a function of the thickness of the SC layer. X-ray diffraction analysis of the QD embedded test structures reveals a relationship between the SC thickness and the observed crystalline quality. Air mass zero illuminated current vs. voltage data and spectral responsivity measurements were used for the solar cell comparison. When SC is employed, QD insertion shows a lower open circuit voltage, in reference to a baseline device without QDs, but leads to an enhancement in the short circuit current of the device.
Various temperature dependent optoelectronic properties were measured for GaAs-based p-type / intrinsic / n-type (pin) solar cell devices containing 5-layers of InAs quantum dots (QDs) grown with strain-compensation layers. Curve fitting of the dark diode characteristics allowed for the temperature dependence of the saturation current and the ideality parameter to be determined. The resulting parameter values indicate high material quality. Air mass zero illuminated current density vs. voltage measurements were used to determine the temperature coefficients of the open circuit voltage, short circuit current, maximum power, and fill factor. A strong correlation between the temperature dependent quantum dot electroluminescence peak emission wavelength and the sub-GaAs bandgap spectral response was observed.
The growth of InAs quantum dots (QDs) by organometallic vapor phase epitaxy (OMVPE) for use in GaAs based photovoltaics devices was investigated. Growth of InAs quantum dots was optimized according to their morphology and photoluminescence using growth temperature and V/III ratio. The optimized InAs QDs had sizes near 7×40 nm with a dot density of 5(±0.5)×1010 cm-2. These optimized QDs were incorporated into GaAs based p-i-n solar cell structures. Cells with single and multiple (5x) layers of QDs were embedded in the i-region of the GaAs p-i-n cell structure. An array of 1 cm2 solar cells was fabricated on these wafers, IV curves collected under 1 sun AM0 conditions, and the spectral response measured from 300-1100 nm. The quantum efficiency for each QD cell clearly shows sub-bandgap conversion, indicating a contribution due to the QDs. Unfortunately, the overarching result of the addition of quantum dots to the baseline p-i-n GaAs cells was a decrease in efficiency. However, the addition of thin GaP strain compensating layers between the QD layers, was found to reduce this efficiency degradation and significantly enhance the subgap conversion in comparison to the un-compensated quantum dot cells.
Bacterial cell biology and pathogenesis
Helen J. Betts, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Christopher M. Bailey, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Mark J. Pallen, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Ian R. Henderson, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK
To survive in any given niche, bacteria must be capable of sensing, interacting with, and responding to their environment. The method and extent to which bacteria interact with their environment are governed to a large degree by the proteinaceous molecules located on the bacterial cell surface or released into the extracellular milieu. Due to differences in cell-envelope architecture, this process of protein secretion is markedly different between Gram-positive and Gram-negative organisms.
GRAM-POSITIVE VERSUS GRAM-NEGATIVE BACTERIA
Gram-positive bacteria possess a single biological membrane termed the cytoplasmic membrane, which is surrounded by a thick cell wall. The majority of proteins targeted for secretion possess an N-terminal amino-acid signal peptide and utilize the Sec-dependent pathway (Holland, 2004). The Sec machinery is composed of several membrane-associated proteins, including an ATPase (SecA), the Sec translocon (SecYEG), which appears to be the basic unit of cellular life forms, several integral membrane proteins (e.g. SecD, SecF), and a signal peptidase that removes the signal peptide during translocation of the proteins across the cytoplasmic membrane (Dalbey and Chen, 2004). In addition to the Sec pathway, several alternative protein-secretion systems have been recognized in Gram-positive organisms, including the Tat (twin arginine translocation) and ESAT-6/WXG-100 pathways (Pallen, 2002; Robinson and Bolhuis, 2004). However, the role of these systems in protein secretion in Gram-positive bacteria is minor in comparison with the Sec-dependent pathway. Once translocated across the cytoplasmic membrane, the mature protein either can be released into the extracellular milieu or may remain in contact with the cell wall.
The current project examined the impact of differential motivation on
baseline versus post-mild traumatic brain injury (MTBI)
neuropsychological measures in athletes. Collegiate athletes were
administered a neuropsychological battery prior to and post-MTBI. High
Motivation at Baseline (HMB) and Suspect Motivation at Baseline (SMB)
groups were established for each measure based on whether baseline
performance fell +/− one or more standard deviations from the
mean of the given measure. Greater improvement was expected in the SMB
group than the HMB group given hypothesized differences in baseline
motivation. In repeated measures analysis of covariance (ANCOVA) that
removed achievement performance, the SMB groups demonstrated greater
improvement than the HMB groups for the Trail Making Test A & B (TMT-A
& B), Digit Span, and Stroop-Color Word (Stroop-CW) tests. Also, the
percentage of participants who improved according to reliable change
indices was greater for the SMB groups on the TMT-A & B, Stroop-CW,
and the Vigil. These findings are likely due to lower motivation in the
SMB group for each test. However, results also suggest that some tests may
be relatively unaffected by motivation. These data may have clinical
implications and point to the need for better methods of identifying
athletes with suspect motivation at baseline. (JINS, 2006,