1,222 research outputs found
Convective instability induced by nonlocality in nonlinear diffusive systems
We consider a large class of nonlinear diffusive systems with nonlocal
coupling. By using a non-perturbative analytical approach we are able to
determine the convective and absolute instabilities of all the uniform states
of these systems. We find a huge window of convective instability that should
provide a great opportunity to study experimentally and theoretically noise
sustained patterns.Comment: 5 pages, accepted for publication in PR
Spectroscopic Characterization of Multilayered Functional Protective Polymers via Surface Modification with Organic Polymers against Highly Toxic Chemicals
Recent advances in biopolymers, including functional biomaterials for the manufacture of personal protective garments (PPGs) or equipment (PPE) have dramatically improved their efficiency and performance. Good and acceptable permeation characteristics, mechanical strength and durability are common attributes of these materials simultaneously without compromise for their cost-effectiveness and manufacturability. The comprehensive characterization of these materials and specimens’ three-dimensionality with the endeavor to obtain the highest resistance to highly toxic agents such as nuclear, chemical and biological warfare agents is the must fulfilling aim in today’s global interest in continuous development in this area
Genetic diversity and population structure in the Ryukyu flying fox inferred from remote sampling in the Yaeyama archipelago
The Ryukyu flying fox (Pteropus dasymallus) is distributed throughout the island chain spanning across southern Japan, Taiwan, and possibly the Philippines. Although P. dasymallus is listed as VU (vulnerable) in the IUCN Red List, only few genetic works have been conducted to support its conservation. In this study we analyzed 19 markers (mtDNA haplotypes and 18 microsatellite markers) to evaluate genetic diversity and investigate the genetic structure of this species. mtDNA analysis was conducted with 142 DNA remote samples, mostly from faeces, and wing tissues collected on eight islands (Miyako, Ishigaki, Kohama, Kuroshima, Hateruma, Taketomi, Iriomote, Yonaguni). 39 haplotypes were identified in 526bp of the control region, and haplotype network showed no clear genetic structure. Microsatellite analysis was also conducted with 155 samples collected on six islands (Miyako, Ishigaki, Kohama, Taketomi, Iriomote, Yonaguni). It showed that the Yonaguni population exhibits low genetic diversity, high inbreeding, and clear genetic differentiation from other populations. Gene flow between Ishigaki and Miyako through small stepstone islands might be preventing inbreeding of the Miyako population. We provide for the first time indirect proof of long-distance inter-island dispersal in the Ryukyu flying fox and revealed genetic diversity, gene flow and genetic differentiation among the archipelago's populations. These results will be useful for delineating conservation units and designing specific conservation policies for each island based on metapopulation genetic structure
Reverse taxonomy for elucidating diversity of insect-associated nematodes: a case study with termites
BACKGROUND: The molecular operational taxonomic unit(MOTU)has recently been applied to microbial and microscopic animal biodiversity surveys. However, in many cases, some of the MOTUs cannot be definitively tied to any of the taxonomic groups in current databases. To surmount these limitations, the concept of "reverse taxonomy" has been proposed, i.e. to primarily list the MOTUs with morphological information, and then identify and/or describe them at genus/species level using subsamples or by re-isolating the target organisms. Nevertheless, the application of "reverse taxonomy" has not been sufficiently evaluated. Therefore, the practical applicability of "reverse taxonomy" is tested using termite-associated nematodes as a model system for phoretic/parasitic organisms which have high habitat specificity and a potential handle (their termite host species) for re-isolation attempts. METHODOLOGY: Forty-eight species (from 298 colonies) of termites collected from the American tropics and subtropics were examined for their nematode associates using the reverse taxonomy method and culturing attempts (morphological identification and further sequencing efforts). The survey yielded 51 sequence types (= MOTUs) belonging to 19 tentatively identified genera. Within these, four were identified based on molecular data with preliminary morphological observation, and an additional seven were identified or characterized from successful culturing, leaving eight genera unidentified. CONCLUSIONS: That 1/3 of the genera were not successfully identified suggests deficiencies in the depth of available sequences in the database and biological characters, i.e. usually isolated as phoretic/parasitic stages which are not available for morphological identification, and too many undiscovered lineages of nematodes. Although there still is the issue of culturability of nematodes, culturing attempts could help to make reverse taxonomy methods more effective. However, expansion of the database, i.e., production of more DNA barcodes tied to biological information by finding and characterizing additional new and known lineages, is necessary for analyzing functional diversity.Natsumi Kanzaki, Robin M. Giblin-Davis, Rudolf H. Scheffrahn, Hisatomo Taki, Alejandro Esquivel, Kerrie A. Davies and E. Allen Herr
K3 surfaces and log del Pezzo surfaces of index three
We use classification of non-symplectic automorphisms of K3 surfaces to
obtain a partial classification of log del Pezzo surfaces of index three. We
can classify those with "Multiple Smooth Divisor Property", whose definition we
will give. Our methods include the definition of right resolutions of quotient
singularities of index three and some analysis of automorphism-stable elliptic
fibrations on K3 surfaces. In particular we find several log del Pezzo surfaces
of Picard number one with non-toric singularities of index three.Comment: 32 pages, to appear in Manuscripta Mat
Optical fiber systems are convectively unstable
We theoretically and experimentally evidence that fiber systems are convective systems since their nonlocal inherent properties, such as the dispersion and Raman effects, break the reflection symmetry. Theoretical analysis and numerical simulations carried out for a fiber ring cavity demonstrate that the third-order dispersion term leads to the appearance of convective and absolute instabilities. Their signature is an asymmetry in the output power spectrum. Using this criterion, experimental evidence of convective instabilities is given in a fiber cavity pumped by a pulsed laser
Re-Assessing TOD Index in Jakarta Metropolitan Region (JMR)
Transit Oriented Development (TOD) is believed to be able to overcome the issues of urban transport. However, in practice, the current TOD in Jakarta Metropolitan Region (JMR) is still a deficiency in accommodating the needs of transportation movement and not in facilitating services in terms of TOD function. The objective of this paper was to re-assess the service quality of actual TOD in 54 commuter railway stations. The paper performed criteria-indicators and measured a composite TOD index by using Analytical Hierarchy Process (AHP)-multicriteria model, statistics test, and Geographical Information System (GIS) application. TOD index was found that urban areas have a high TOD index. On the other hand, the suburban areas have a low TOD-index. The statistical test showed that there was a strong correlation between different criteria. This paper concluded that most of the stations which were located in the suburban area had a low index thus need improvement. Consequently, the station areas needed to have a policy relevance.
 
Infant Feeding Websites and Apps: A Systematic Assessment of Quality and Content
Background: Internet websites and smartphone apps have become a popular resource to guide parents in their children’s feeding and nutrition. Given the diverse range of websites and apps on infant feeding, the quality of information in these resources should be assessed to identify whether consumers have access to credible and reliable information.Objective: This systematic analysis provides perspectives on the information available about infant feeding on websites and smartphone apps.Methods: A systematic analysis was conducted to assess the quality, comprehensibility, suitability, and readability of websites and apps on infant feeding using a developed tool. Google and Bing were used to search for websites from Australia, while the App Store for iOS and Google Play for Android were used to search for apps. Specified key words including baby feeding, breast feeding, formula feeding and introducing solids were used to assess websites and apps addressing feeding advice. Criteria for assessing the accuracy of the content were developed using the Australian Infant Feeding Guidelines.Results: A total of 600 websites and 2884 apps were screened, and 44 websites and 46 apps met the selection criteria and were analyzed. Most of the websites (26/44) and apps (43/46) were noncommercial, some websites (10/44) and 1 app were commercial and there were 8 government websites; 2 apps had university endorsement. The majority of the websites and apps were rated poor quality. There were two websites that had 100% coverage of information compared to those rated as fair or poor that had low coverage. Two-thirds of the websites (65%) and almost half of the apps (47%) had a readability level above the 8th grade level.Conclusions: The findings of this unique analysis highlight the potential for website and app developers to merge user requirements with evidence-based content to ensure that information on infant feeding is of high quality. There are currently no apps available to consumers that address a variety of infant feeding topics. To keep up with the rapid turnover of the evolving technology, health professionals need to consider developing an app that will provide consumers with a credible and reliable source of information about infant feeding, using quality assessment tools and evidence-based content
A qualitative study of the infant feeding beliefs and behaviours of mothers with low educational attainment
© 2016 Russell et al. Background: Infancy is an important period for the promotion of healthy eating, diet and weight. However little is known about how best to engage caregivers of infants in healthy eating programs. This is particularly true for caregivers, infants and children from socioeconomically disadvantaged backgrounds who experience greater rates of overweight and obesity yet are more challenging to reach in health programs. Behaviour change interventions targeting parent-infant feeding interactions are more likely to be effective if assumptions about what needs to change for the target behaviours to occur are identified. As such we explored the precursors of key obesity promoting infant feeding practices in mothers with low educational attainment. Methods: One-on-one semi-structured telephone interviews were developed around the Capability Opportunity Motivation Behaviour (COM-B) framework and applied to parental feeding practices associated with infant excess or healthy weight gain. The target behaviours and their competing alternatives were (a) initiating breastfeeding/formula feeding, (b) prolonging breastfeeding/replacing breast milk with formula, (c) best practice formula preparation/sub-optimal formula preparation, (d) delaying the introduction of solid foods until around six months of age/introducing solids earlier than four months of age, and (e) introducing healthy first foods/introducing unhealthy first foods, and (f) feeding to appetite/use of non-nutritive (i.e., feeding for reasons other than hunger) feeding. The participants' education level was used as the indicator of socioeconomic disadvantage. Two researchers independently undertook thematic analysis. Results: Participants were 29 mothers of infants aged 2-11 months. The COM-B elements of Social and Environmental Opportunity, Psychological Capability, and Reflective Motivation were the key elements identified as determinants of a mother's likelihood to adopt the healthy target behaviours although the relative importance of each of the COM-B factors varied with each of the target feeding behaviours. Conclusions: Interventions targeting healthy infant feeding practices should be tailored to the unique factors that may influence mothers' various feeding practices, taking into account motivational and social influences
Convection-induced nonlinear-symmetry-breaking in wave mixing
We show that the combined action of diffraction and convection (walk-off) in
wave mixing processes leads to a nonlinear-symmetry-breaking in the generated
traveling waves. The dynamics near to threshold is reduced to a Ginzburg-Landau
model, showing an original dependence of the nonlinear self-coupling term on
the convection. Analytical expressions of the intensity and the velocity of
traveling waves emphasize the utmost importance of convection in this
phenomenon. These predictions are in excellent agreement with the numerical
solutions of the full dynamical model.Comment: 5 page
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