130 research outputs found
Separation of bacterial spores from flowing water in macro-scale cavities by ultrasonic standing waves
The separation of micron-sized bacterial spores (Bacillus cereus) from a
steady flow of water through the use of ultrasonic standing waves is
demonstrated. An ultrasonic resonator with cross-section of 0.0254 m x 0.0254 m
has been designed with a flow inlet and outlet for a water stream that ensures
laminar flow conditions into and out of the resonator section of the flow tube.
A 0.01905-m diameter PZT-4, nominal 2-MHz transducer is used to generate
ultrasonic standing waves in the resonator. The acoustic resonator is 0.0356 m
from transducer face to the opposite reflector wall with the acoustic field in
a direction orthogonal to the water flow direction. At fixed frequency
excitation, spores are concentrated at the stable locations of the acoustic
radiation force and trapped in the resonator region. The effect of the
transducer voltage and frequency on the efficiency of spore capture in the
resonator has been investigated. Successful separation of B. cereus spores from
water with typical volume flow rates of 40-250 ml/min has been achieved with
15% efficiency in a single pass at 40 ml/min.Comment: 11 pages, 6 figure
Ising Field Theory on a Pseudosphere
We show how the symmetries of the Ising field theory on a pseudosphere can be
exploited to derive the form factors of the spin fields as well as the
non-linear differential equations satisfied by the corresponding two-point
correlation functions. The latter are studied in detail and, in particular, we
present a solution to the so-called connection problem relating two of the
singular points of the associated Painleve VI equation. A brief discussion of
the thermodynamic properties is also presented.Comment: 39 pages, 6 eps figures, uses harvma
Sensory processing in young children with visual impairments:Use and extension of the Sensory Profile
Background: Children with visual impairments (VI) are at risk for sensory processing difficulties. A widely used measure for sensory processing is the Sensory Profile (SP). However, the SP requires adaptation to accommodate for how children with VI experience sensory information. Aims: (1) To examine sensory processing patterns in young children with VI, (2) to develop VI-specific items to use in conjunction with the SP and to determine internal consistency and construct validity of these newly developed items, and (3) to examine the association between sensory processing and and emotional and behavioral problems. Methods: Twenty-six VI-specific items were added to the SP. The SP and these items were completed by caregivers of 90 children with VI between 3 and 8 years old. The Child Behavior Checklist (CBCL) was used to assess emotional and behavioral problems. Results: Three- to five-year-old children with VI have significantly more difficulties in three quadrants of the SP as compared to the norm group. Six- to eight-year-old children with VI have more difficulties in all quadrants. A reliable and valid VI-specific set of 15 items was established following psychometric evaluation. Age-related differences were found in the associations between the SP and CBCL. Conclusion: Although further validation is recommended, this evaluation of the VI-specific item set suggests it has the potential to be a useful measure for children with VI
SolRgene: an online database to explore disease resistance genes in tuber-bearing Solanum species
Background The cultivated potato (Solanum tuberosum L.) is an important food crop, but highly susceptible to many pathogens. The major threat to potato production is the Irish famine pathogen Phytophthora infestans, which causes the devastating late blight disease. Potato breeding makes use of germplasm from wild relatives (wild germplasm) to introduce resistances into cultivated potato. The Solanum section Petota comprises tuber-bearing species that are potential donors of new disease resistance genes. The aim of this study was to explore Solanum section Petota for resistance genes and generate a widely accessible resource that is useful for studying and implementing disease resistance in potato. Description The SolRgene database contains data on resistance to P. infestans and presence of R genes and R gene homologues in Solanum section Petota. We have explored Solanum section Petota for resistance to late blight in high throughput disease tests under various laboratory conditions and in field trials. From resistant wild germplasm, segregating populations were generated and assessed for the presence of resistance genes. All these data have been entered into the SolRgene database. To facilitate genetic and resistance gene evolution studies, phylogenetic data of the entire SolRgene collection are included, as well as a tool for generating phylogenetic trees of selected groups of germplasm. Data from resistance gene allele-mining studies are incorporated, which enables detection of R gene homologs in related germplasm. Using these resources, various resistance genes have been detected and some of these have been cloned, whereas others are in the cloning pipeline. All this information is stored in the online SolRgene database, which allows users to query resistance data, sequences, passport data of the accessions, and phylogenic classifications. Conclusion Solanum section Petota forms the basis of the SolRgene database, which contains a collection of resistance data of an unprecedented size and precision. Complemented with R gene sequence data and phylogenetic tools, SolRgene can be considered the primary resource for information on R genes from potato and wild tuber-bearing relatives
The dynamic exponent of the Ising model on negatively curved surfaces
We investigate the dynamic critical exponent of the two-dimensional Ising
model defined on a curved surface with constant negative curvature. By using
the short-time relaxation method, we find a quantitative alteration of the
dynamic exponent from the known value for the planar Ising model. This
phenomenon is attributed to the fact that the Ising lattices embedded on
negatively curved surfaces act as ones in infinite dimensions, thus yielding
the dynamic exponent deduced from mean field theory. We further demonstrate
that the static critical exponent for the correlation length exhibits the mean
field exponent, which agrees with the existing results obtained from canonical
Monte Carlo simulations.Comment: 14 pages, 3 figures. to appear in J. Stat. Mec
Geometric effects on critical behaviours of the Ising model
We investigate the critical behaviour of the two-dimensional Ising model
defined on a curved surface with a constant negative curvature. Finite-size
scaling analysis reveals that the critical exponents for the zero-field
magnetic susceptibility and the correlation length deviate from those for the
Ising lattice model on a flat plane. Furthermore, when reducing the effects of
boundary spins, the values of the critical exponents tend to those derived from
the mean field theory. These findings evidence that the underlying geometric
character is responsible for the critical properties the Ising model when the
lattice is embedded on negatively curved surfaces.Comment: 16 pages, 6 figures, to appear in J. Phys. A: Math. Ge
Phase Transition of the Ising model on a Hyperbolic Lattice
The matrix product structure is considered on a regular lattice in the
hyperbolic plane. The phase transition of the Ising model is observed on the
hyperbolic lattice by means of the corner-transfer-matrix
renormalization group (CTMRG) method. Calculated correlation length is always
finite even at the transition temperature, where mean-field like behavior is
observed. The entanglement entropy is also always finite.Comment: 4 pages, 3 figure
Cannabidiol (EpidyolexÂź) for severe behavioral manifestations in patients with tuberous sclerosis complex, mucopolysaccharidosis type III and fragile X syndrome:protocol for a series of randomized, placebo-controlled N-of-1 trials
Background: Many rare genetic neurodevelopmental disorders (RGNDs) are characterized by intellectual disability (ID), severe cognitive and behavioral impairments, potentially diagnosed as a comorbid autism spectrum disorder or attention-deficit hyperactivity disorder. Quality of life is often impaired due to irritability, aggression and self-injurious behavior, generally refractory to standard therapies. There are indications from previous (case) studies and patient reporting that cannabidiol (CBD) may be an effective treatment for severe behavioral manifestations in RGNDs. However, clear evidence is lacking and interventional research is challenging due to the rarity as well as the heterogeneity within and between disease groups and interindividual differences in treatment response. Our objective is to examine the effectiveness of CBD on severe behavioral manifestations in three RGNDs, including Tuberous Sclerosis Complex (TSC), mucopolysaccharidosis type III (MPS III), and Fragile X syndrome (FXS), using an innovative trial design. Methods: We aim to conduct placebo-controlled, double-blind, block-randomized, multiple crossover N-of-1 studies with oral CBD (twice daily) in 30 patients (aged â„ 6Â years) with confirmed TSC, MPS III or FXS and severe behavioral manifestations. The treatment is oral CBD up to a maximum of 25Â mg/kg/day, twice daily. The primary outcome measure is the subscale irritability of the Aberrant Behavior Checklist. Secondary outcome measures include (personalized) patient-reported outcome measures with regard to behavioral and psychiatric outcomes, disease-specific outcome measures, parental stress, seizure frequency, and adverse effects of CBD. Questionnaires will be completed and study medication will be taken at the participantsâ natural setting. Individual treatment effects will be determined based on summary statistics. A mixed model analysis will be applied for analyzing the effectiveness of the intervention per disorder and across disorders combining data from the individual N-of-1 trials. Discussion: These N-of-1 trials address an unmet medical need and will provide information on the effectiveness of CBD for severe behavioral manifestations in RGNDs, potentially generating generalizable knowledge at an individual-, disorder- and RGND population level. Trial registration: EudraCT: 2021-003250-23, registered 25 August 2022, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-003250-23/NL .</p
Cannabidiol (EpidyolexÂź) for severe behavioral manifestations in patients with tuberous sclerosis complex, mucopolysaccharidosis type III and fragile X syndrome:protocol for a series of randomized, placebo-controlled N-of-1 trials
Background: Many rare genetic neurodevelopmental disorders (RGNDs) are characterized by intellectual disability (ID), severe cognitive and behavioral impairments, potentially diagnosed as a comorbid autism spectrum disorder or attention-deficit hyperactivity disorder. Quality of life is often impaired due to irritability, aggression and self-injurious behavior, generally refractory to standard therapies. There are indications from previous (case) studies and patient reporting that cannabidiol (CBD) may be an effective treatment for severe behavioral manifestations in RGNDs. However, clear evidence is lacking and interventional research is challenging due to the rarity as well as the heterogeneity within and between disease groups and interindividual differences in treatment response. Our objective is to examine the effectiveness of CBD on severe behavioral manifestations in three RGNDs, including Tuberous Sclerosis Complex (TSC), mucopolysaccharidosis type III (MPS III), and Fragile X syndrome (FXS), using an innovative trial design. Methods: We aim to conduct placebo-controlled, double-blind, block-randomized, multiple crossover N-of-1 studies with oral CBD (twice daily) in 30 patients (aged â„ 6Â years) with confirmed TSC, MPS III or FXS and severe behavioral manifestations. The treatment is oral CBD up to a maximum of 25Â mg/kg/day, twice daily. The primary outcome measure is the subscale irritability of the Aberrant Behavior Checklist. Secondary outcome measures include (personalized) patient-reported outcome measures with regard to behavioral and psychiatric outcomes, disease-specific outcome measures, parental stress, seizure frequency, and adverse effects of CBD. Questionnaires will be completed and study medication will be taken at the participantsâ natural setting. Individual treatment effects will be determined based on summary statistics. A mixed model analysis will be applied for analyzing the effectiveness of the intervention per disorder and across disorders combining data from the individual N-of-1 trials. Discussion: These N-of-1 trials address an unmet medical need and will provide information on the effectiveness of CBD for severe behavioral manifestations in RGNDs, potentially generating generalizable knowledge at an individual-, disorder- and RGND population level. Trial registration: EudraCT: 2021-003250-23, registered 25 August 2022, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-003250-23/NL .</p
Periodic boundary conditions on the pseudosphere
We provide a framework to build periodic boundary conditions on the
pseudosphere (or hyperbolic plane), the infinite two-dimensional Riemannian
space of constant negative curvature. Starting from the common case of periodic
boundary conditions in the Euclidean plane, we introduce all the needed
mathematical notions and sketch a classification of periodic boundary
conditions on the hyperbolic plane. We stress the possible applications in
statistical mechanics for studying the bulk behavior of physical systems and we
illustrate how to implement such periodic boundary conditions in two examples,
the dynamics of particles on the pseudosphere and the study of classical spins
on hyperbolic lattices.Comment: 30 pages, minor corrections, accepted to J. Phys.
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