To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.
To assess quality of life of children and teenagers with recurrent respiratory papillomatosis, according to the evidence of infection by human papillomavirus types 6 and 11, compared with healthy volunteers and patients with chronic otitis media.
Participants and their parents completed the Pediatric Quality of Life Inventory 4.0.
Patients with recurrent respiratory papillomatosis and their parents reported lower quality of life than healthy subjects (p < 0.01), but similar quality of life to patients with chronic otitis media. Those with human papillomavirus type 11 showed the lowest scores among all participants (p < 0.05).
Young Mexican patients with recurrent respiratory papillomatosis and their parents perceive a poor quality of life, and they may experience limitations in interactions with their peers. Infection by human papillomavirus type 11 may increase the impact of the disease on quality of life.
This paper reports the results of the first three in a series of experiments on tactile perception which form part of a larger project on tactile perceptions and spatial representations and the design of tactile interfaces for mobility devices for blind, partially sighted and deafblind people. The results indicate the potential of tactile interfaces, including to support environmental exploration and mobility. The participants showed reasonably good ability to determine the direction of motion of an arrow, with best recognition rates in the up and right directions. They showed reasonably good ability to use a tactile interface to detect and avoid obstacles after a very short learning period and more limited ability to learn and remember an environmental representation using information from a tactile interface and walking through the environment without specific instructions.
A metallurgical by product mostly constituted of Wustita (FeO) was transformed to Magnetite (Fe3O4) spheres using a flame treatment. Then magnetite spheres surface was modified by cold plasma treatment with ethylene, where a thin polyethylene film was deposited on the spheres surface. Finally, HDPE composites with modified spheres were obtained by melt mixing and its thermal conductivity was determined by MDSC. It was found that spheres surface modification helps to increase composites thermal conductivity.
We present a technique to detect Ultra-Faint Dwarf Galaxies (UFDs) in the Galactic Halo, using sky and proper motion information.The method uses wavelet transforms to detect peaks in the sky and proper motion planes, and to evaluate the probability of these being stochastic fluctuations. We aim to map thoroughly the detection limits of this technique. For this, we have produced a library of 15,000 synthetic UFDs, embedded in the Gaia Universe Model Snapshot (GUMS) background (Robin et al. 2012), each at a different distance, different luminosity, half-light radius, velocity dispersion and center-of-mass velocity, varying in ranges that extend well beyond those spanned by known classical and ultra-faint dSphs. We use these synthetic UFDs as a benchmark to characterize the completeness and detection limits of our technique, and present our results as a function of different physical and observable parameters of the UFDs (see full poster for more details at https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/Poster_UFGX_Bcn_C_Mateu.pdf).
To describe the development and application of the School Food Environment Assessment Tools and a novel scoring system to assess the integration of healthy and environmentally sustainable food initiatives in elementary and secondary schools.
The cross-sectional study included direct observations of physical food environments and interviews with key school personnel regarding food-related programmes and policies. A five-point scoring system was then developed to assess actions across six domains: (i) food gardens; (ii) composting systems; (iii) food preparation activities; (iv) food-related teaching and learning activities; and availability of (v) healthy food; and (vi) environmentally sustainable food.
A purposive sample of public schools (n 33) from all six sectors of the Vancouver Board of Education.
Schools scored highest in the areas of food garden and compost system development and use. Regular integration of food-related teaching and learning activities and hands-on food preparation experiences were also commonly reported. Most schools demonstrated rudimentary efforts to make healthy and environmentally sustainable food choices available, but in general scored lowest on these two domains. Moreover, no schools reported widespread initiatives fully supporting availability or integration of healthy or environmentally sustainable foods across campus.
More work is needed in all areas to fully integrate programmes and policies that support healthy, environmentally sustainable food systems in Vancouver schools. The assessment tools and proposed indicators offer a practical approach for researchers, policy makers and school stakeholders to assess school food system environments, identify priority areas for intervention and track relevant changes over time.
Scanning electronic microscopy (SEM), X ray diffraction (XRD) and photoluminescence (PL) have been applied to the study of structural and optical properties of ZnO nanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO nanocrystals (NCs), as well as to vary their photoluminescence spectra. The study has revealed three types of PL bands in ZnO NCs: defect related emission, the near-band-edge (NBE) PL, related to the LO phonon replica of free exciton (FE) recombination, and its second-order diffraction peaks. The PL bands, related to the LO phonon replica of FE, and its second-order diffraction in the room temperature Pl spectrum testify on the high quality of ZnO films prepared by the USP technology.
To examine associations between students’ socio-economic status (SES) and school-day dietary intake, and the roles of parents and peers in shaping these associations.
A cross-sectional survey measured school-day intake of vegetables, whole grains, low-fat milk, packaged snack foods and sugar-sweetened beverages. Logistic regression models examined associations between SES (parental education and food insecurity status) and dietary outcomes during or en route to or from school, and examined whether peer modelling or parental norms potentially mediated the associations between SES and dietary outcomes.
Twenty-six public schools in Vancouver, Canada in 2012.
Nine hundred and fifty students in grades 5–8.
Students whose parents completed some college, compared with those completing high school or less, were significantly more likely to consume vegetables daily (unadjusted OR=1·85; 95 % CI 1·06, 3·22) and students whose parents completed college or university were significantly less likely to consume sugar-sweetened beverages daily (unadjusted OR=0·67; 95 % CI 0·47, 0·94). Food secure students were also significantly less likely to consume sugar-sweetened beverages daily compared with food insecure students (unadjusted OR=0·52; 95 % CI 0·29, 0·92). Parental norms, but not peer modelling, emerged as a potential mediator of the association between SES and vegetable intake. SES was not significantly associated with the remaining dietary outcomes.
Higher SES was significantly associated with two of five school-day dietary outcomes and predicted higher likelihood of daily nutritious food choices at school. The present study suggests that there is room for improvement in school-day dietary quality for students from all SES backgrounds in Vancouver.
The increasing use of polymeric reinforcements in concrete structures requires either the development of a new design theory or the adaptation of current designs considering the engineering properties of this type of materials. In this work a method for calculating the deflections of reinforced concrete elements is proposed, which can be used in predicting the flexural behavior of longitudinally reinforced concrete with PET strips in amounts up to 1%. The model theory assumes that concrete has a tensile load capacity different to zero, characterized by a uniaxial tensile stress-strain diagram. A series of tests were conducted to corroborate the validity of the suggested method, showing that the theory also correctly predicts the creep deformation post-cracking. The deflection results of reinforced concrete with recycled PET strips are presented. The tests are carried out by a simple beam with center-point loading, using three different amounts of reinforcement and comparing the experimental results with the theoretical results of the proposed model.
Collagen-covered prostheses can be used as a non-circumferential segmental tracheal replacement. However, the applicability of these implants in young subjects has not yet been reported.
In this experimental, longitudinal study, dogs aged 29–32 days underwent limited segmental tracheal replacement with a polyester prosthesis or were allocated to a control, untreated group. The dogs were evaluated clinically, endoscopically and tomographically for up to one year.
Although there was evidence of tracheal growth in the experimental group, tomographic measurements were significantly smaller in this group than in the control group throughout the observation period. At the end of the study, there was no evidence of implant rejection, stenosis or collapse. Normal respiratory epithelium had grown across the implanted membrane in the experimental group.
The homologous collagen mersylene membrane allowed for limited structural tracheal growth and was functionally integrated into the segmented tracheal wall in growing dogs.
The photoluminescence, its temperature dependences, as well as structural characteristics obtained by the method of Scanning electronic microscopy (SEM) have been studied in ZnO:Ag nanorods prepared by the ultrasonic spray pyrolysis (USP). PL spectra of ZnO:Ag NRs in the temperature range from 10 K to 300 K are investigated. Three types of PL bands have been revealed: i) the near-band-edge (NBE) emission, ii) defect related emission and iii) IR emission. It is shown that IR emission corresponds to the second-order diffraction of near-band-edge (NBE) emission bands. The study of NBE PL temperature dependences reveals that the acceptor bound exciton (ABE) and its second-order diffraction peak disappeared at the temperature higher than 200 K. The attenuation of the ABE peak intensity is ascribed to the thermal dissociation of ABE with appearing a free exciton (FE). The PL bands, related to the LO phonon replica of FE and its second-order diffraction, dominate in the PL spectra at room temperature that testify on the high quality of ZnO:Ag films prepared by the USP technology.
Genetic diversity of Trypanosoma cruzi may play a role in pathogenesis of Chagas disease forms. Natural populations are classified into 6 Discrete Typing Units (DTUs) Tc I-VI with taxonomical status. This study aimed to identify T. cruzi DTUs in bloodstream and tissue samples of Argentinean patients with Chagas disease. PCR-based strategies allowed DTU identification in 256 clinical samples from 239 Argentinean patients. Tc V prevailed in blood from both asymptomatic and symptomatic cases and Tc I was more frequent in bloodstream, cardiac tissues and chagoma samples from immunosuppressed patients. Tc II and VI were identified in a minority of cases, while Tc III and Tc IV were not detected in the studied population. Interestingly, Tc I and Tc II/VI sequences were amplified from the same skin biopsy slice from a kidney transplant patient suffering Chagas disease reactivation. Further data also revealed the occurrence of mixed DTU populations in the human chronic infection. In conclusion, our findings provide evidence of the complexity of the dynamics of T. cruzi diversity in the natural history of human Chagas disease and allege the pathogenic role of DTUs I, II, V and VI in the studied population.
A characteristic mechanism of gene expression regulation during seed germination is the selective translation of mRNAs. Previous findings indicate that the two cap-binding complexes eIF4F (with eIF4E and eIF4G subunits) and eIF(iso)4F [with eIF(iso)4E and eIF(iso)4G subunits] are differentially expressed during maize seed germination. In addition, several studies in vitro have suggested that these factors may participate in selective mRNA translation. The translational activities of eIF4E and eIF(iso)4E were tested in vitro using transcripts from two different sets: dry (0 h) and 24-h-imbibed maize embryonic axes. In vitro translation of these mRNA pools in the presence of the recombinant eIF4E or eIF(iso)4E, and the native cap-binding complexes from dry- or 24-h-imbibed axes, produced different profiles of proteins which were visualized by two-dimensional protein gels and autoradiography. The data indicated that eIF(iso)4E was particularly required for translation of the stored mRNAs from dry seeds, and that eIF4E was unable to fully replace the eIF(iso)4E activity. In addition, the dry seed mRNA pool was translated by the cap-binding complex isolated from dry seeds better than by the complex isolated from 24-h-imbibed seeds, whereas the translational efficiency of the mRNA pool from 24-h-imbibed seeds was similar between the cap-binding complexes from these two stages. Interestingly, eIF(iso)4E was more abundant than eIF4E in dry seeds, while both cap-binding proteins were present at similar levels in 24-h-imbibed seeds. These results suggest that the ratio of eIF(iso)4E to eIF4E in the corresponding eIF4F complex is critical for the mechanisms of translational control during maize germination.
With the help of a spectral formalism recently formulated, we study the effects in the optical response of the material properties of a nanoparticle lying over a substrate. A spectral representation was formulated to calculate the optical response of spheroidal nanoparticles including multipolar effects. We present our results in terms of Differential Reflectance spectra that can be compared directly with measurements. We have found that multipolar contributions depend in the shape of the particle and type of substrate.
We study the Casimir force between a nanoparticle and a substrate using a spectral representation formalism. We consider the interaction of metal nanoparticles with different substrates within the dipolar approximation. The force is calculated as a function of the distance between the particles and the substrate. The particles are made of gold or potassium spheres, and the substrate is titanium dioxide, sapphire or a perfect conductor.
Boron carbonitride nanotubes (BCNNTs) were grown with high yield by arc discharge without catalyst particles or pre-grown template nanostructures. Two types of nanotubes (NTs) were formed: thin NTs with diameters of 10–15 nm and thick NTs with diameters of 25–50 nm, all multiwall. Transmission electron microscopy, electron energy loss spectroscopy, and Raman spectroscopy analyses indicate that the thin NTs are carbon NTs (CNTs) while the thick NTs are BCNNTs wrapped around CNTs. The growth kinetic appears to be faster for CNTs than for BCNNTs. Through the concerted substitution of B and N for C in the in situ grown CNTs, template growth of BCNNTs follows the CNTs growth without causing topological changes.
The multiple-gate aspect of the Screen Grid Field Effect Transistor (SGrFET) increases functionality and reduces component count of circuits. An independently-driven gate SGrFET is used to control the switching voltage as well as the gain factor of an inverter. The multi-gate configuration of the SGrFET allows a decrease in output conductance without an increase of transistors count. This leads to a reduction in fabrication complexity, chip area and parasitics. In addition, a simple SGrFETs-based current mirror circuit is proposed with gain factor control.