Magnetically induced Rayleigh-Taylor instability under rotation: Comparison of experimental and theoretical results.

Our theoretical work has shown that rotating a Rayleigh-Taylor-unstable two-layer stratification about a vertical axis slows the development of the instability under gravity and can stabilize axisymmetric modes indefinitely. Here we compare theoretical predictions directly with our experiments on a rotating two-layer system which is made unstable by magnetic forces applied using a superconducting magnet.

Breastfeeding: a key modulator of gut microbiota characteristics in late infancy.

The objective of this study was to investigate the impact of the most commonly cited factors that may have influenced infants' gut microbiota profiles at one year of age: mode of delivery, breastfeeding duration and antibiotic exposure. Barcoded V3/V4 amplicons of bacterial 16S-rRNA gene were prepared from the stool samples of 52 healthy 1-year-old Australian children and sequenced using the Illumina MiSeq platform. Following the quality checks, the data were processed using the Quantitative Insights Into Microbial Ecology pipeline and analysed using the Calypso package for microbiome data analysis. The stool microbiota profiles of children still breastfed were significantly different from that of children weaned earlier (P<0.05), independent of the age of solid food introduction. Among children still breastfed, Veillonella spp. abundance was higher. Children no longer breastfed possessed a more 'mature' microbiota, with notable increases of Firmicutes. The microbiota profiles of the children could not be differentiated by delivery mode or antibiotic exposure. Further analysis based on children's feeding patterns found children who were breastfed alongside solid food had significantly different microbiota profiles compared to that of children who were receiving both breastmilk and formula milk alongside solid food. This study provided evidence that breastfeeding continues to influence gut microbial community even at late infancy when these children are also consuming table foods. At this age, any impacts from mode of delivery or antibiotic exposure did not appear to be discernible imprints on the microbial community profiles of these healthy children.

Magnetic Levitation Stabilized by Streaming Fluid Flows.

We demonstrate that the ubiquitous laboratory magnetic stirrer provides a simple passive method of magnetic levitation, in which the so-called "flea" levitates indefinitely. We study the onset of levitation and quantify the flea's motion (a combination of vertical oscillation, spinning and "waggling"), finding excellent agreement with a mechanical analytical model. The waggling motion drives recirculating flow, producing a centripetal reaction force that stabilized the flea. Our findings have implications for the locomotion of artificial swimmers and the development of bidirectional microfluidic pumps, and they provide an alternative to sophisticated commercial levitators.

Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma.

Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

Shapes and Fissility of Highly Charged and Rapidly Rotating Levitated Liquid Drops.

We use diamagnetic levitation to investigate the shapes and the stability of free electrically charged and spinning liquid drops of volume ∼1 ml. In addition to binary fission and Taylor cone-jet fission modes observed at low and high charge density, respectively, we also observe an unusual mode which appears to be a hybrid of the two. Measurements of the angular momentum required to fission a charged drop show that nonrotating drops become unstable to fission at the amount of charge predicted by Lord Rayleigh. This result is in contrast to the observations of most previous experiments on fissioning charged drops, which typically exhibit fission well below Rayleigh's limit.

Efficacy of interventions to improve feeding difficulties in children with autism spectrum disorders: a systematic review and meta-analysis.

BACKGROUND: Feeding difficulties are relatively common in children with autism spectrum disorders (ASD), but current evidence for their treatment is limited. This review systematically identifies, reviews and analyses the evidence for intervention in young children with ASD and feeding difficulties. METHODS: A comprehensive search strategy was used to identify studies from January 2000 to October 2013. Studies were included if they described interventions where the goal was to increase desirable eating behaviours or decrease undesirable eating behaviours using an experimental design, including single-subject research methodology. Studies were reviewed for descriptive information, and research quality was appraised using a formal checklist. Individual study findings were compared using Improvement Rate Difference (IRD), a method for calculating effect size in single-subject research. RESULTS: Overall, 23 papers were included. All studies reviewed had five or fewer participants, and reported on operant conditioning style intervention approaches, where the child is prompted to perform an action, and receives a contingent response. Where quality measures were not met, it was primarily due to lack of detail provided for the purposes of replication, or failure to meet social validity criteria. Meta-analysis indicated a medium-large effect size [mean = 0.69, 95% confidence interval (CI) 0.60 to 0.79] when the outcome measured was an increase in desirable behaviours (e.g. consuming food), but a small-negligible effect size (mean = 0.39, 95% CI 0.18 to 0.60) when the outcome measured was a decrease in undesirable mealtime behaviours (e.g. tantrums). Only a small proportion of studies reported outcomes in terms of increased dietary variety rather than volume of food consumed. CONCLUSIONS: The reviewed literature consisted primarily of low-level evidence. Favourable intervention outcomes were observed in terms of increasing volume, but not necessarily variety of foods consumed in young children with ASD and feeding difficulties. Further research in the form of prospective randomized trials to further demonstrate experimental effect in this area is required.

Tuneable paramagnetic susceptibility and exciton g-factor in Mn-doped PbS colloidal nanocrystals.

We report on PbS colloidal nanocrystals that combine within one structure solubility in physiological solvents with near-infrared photoluminescence, and magnetic and optical properties tuneable by the controlled incorporation of magnetic impurities (Mn). We use high magnetic fields (B up to 30 T) to measure the magnetization of the nanocrystals in liquid and the strength of the sp-d exchange interaction between the exciton and the Mn-ions. With increasing Mn-content from 0.1% to 7%, the mass magnetic susceptibility increases at a rate of ∼ 10(-7) m(3) kg(-1) per Mn percentage; correspondingly, the exciton g-factor decreases from 0.47 to 0.10. The controlled modification of the paramagnetism, fluorescence and exciton g-factor of the nanocrystals is relevant to the implementation of these paramagnetic semiconductor nanocrystals in quantum technologies ranging from quantum information to magnetic resonance imaging.

Transient transcriptional events in human skeletal muscle at the outset of concentric resistance exercise training.

We sought to ascertain the time course of transcriptional events that occur in human skeletal muscle at the outset of resistance exercise (RE) training in RE naive individuals and determine whether the magnitude of response was associated with exercise-induced muscle damage. Sixteen RE naive men were recruited; eight underwent two sessions of 5 × 30 maximum isokinetic knee extensions (180°/s) separated by 48 h. Muscle biopsies of the vastus lateralis, obtained from different sites, were taken at baseline and 24 h after each exercise bout. Eight individuals acted as nonexercise controls with biopsies obtained at the same time intervals. Transcriptional changes were assessed by microarray and protein levels of heat shock protein (HSP) 27 and αB-crystallin in muscle cross sections by immunohistochemistry as a proxy measure of muscle damage. In control subjects, no probe sets were significantly altered (false discovery rate < 0.05), and HSP27 and αB-crystallin protein remained unchanged throughout the study. In exercised subjects, significant intersubject variability following the initial RE bout was observed in the muscle transcriptome, with greatest changes occurring in subjects with elevated HSP27 and αB-crystallin protein. Following the second bout, the transcriptome response was more consistent, revealing a cohort of probe sets associated with immune activation, the suppression of oxidative metabolism, and ubiquitination, as differentially regulated. The results reveal that the initial transcriptional response to RE is variable in RE naive volunteers, potentially associated with muscle damage and unlikely to reflect longer term adaptations to RE training. These results highlight the importance of considering multiple time points when determining the transcriptional response to RE and associated physiological adaptation.

Spontaneous orbiting of two spheres levitated in a vibrated liquid.

In the absence of gravity, particles can form a suspension in a liquid irrespective of the difference in density between the solid and the liquid. If such a suspension is subjected to vibration, there is relative motion between the particles and the fluid which can lead to self-organization and pattern formation. Here, we describe experiments carried out to investigate the behavior of two identical spheres suspended magnetically in a fluid, mimicking weightless conditions. Under vibration, the spheres mutually attract and, for sufficiently large vibration amplitudes, the spheres are observed to spontaneously orbit each other. The collapse of the experimental data onto a single curve indicates that the instability occurs at a critical value of the streaming Reynolds number. Simulations reproduce the observed behavior qualitatively and quantitatively, and are used to identify the features of the flow that are responsible for this instability.

Addendum to "Vibrations of a diamagnetically levitated water droplet".

We derive an analytical expression for the frequency of the shape oscillations of a diamagnetically levitated water droplet, in which the equilibrium shape is not spherical. We give the eigenfrequencies of all modes to first order in the oscillation amplitude and potential energy of the magnetogravitational trap confining the droplet. We compare the result with experimental measurements of the eigenfrequencies.

Vibrations of a diamagnetically levitated water droplet.

We measure the frequencies of small-amplitude shape oscillations of a magnetically levitated water droplet. The droplet levitates in a magnetogravitational potential trap. The restoring forces of the trap, acting on the droplet's surface in addition to the surface tension, increase the frequency of the oscillations. We derive the eigenfrequencies of the normal mode vibrations of a spherical droplet in the trap and compare them with our experimental measurements. We also consider the effect of the shape of the potential trap on the eigenfrequencies.

Nonaxisymmetric shapes of a magnetically levitated and spinning water droplet.

The shape of a weightless spinning liquid droplet is governed by the balance between the surface tension and centrifugal forces. The axisymmetric shape for slow rotation becomes unstable to a nonaxisymmetric distortion above a critical angular velocity, beyond which the droplet progresses through a series of 2-lobed shapes. Theory predicts the existence of a family of 3- and 4-lobed equilibrium shapes at higher angular velocity. We investigate the formation of a triangular-shaped magnetically levitated water droplet, driven to rotate by the Lorentz force on an ionic current within the droplet. We also study equatorial traveling waves which give the droplet threefold, fourfold, and fivefold symmetry.

Magneto-vibratory separation of glass and bronze granular mixtures immersed in a paramagnetic liquid.

A fluid-immersed granular mixture may spontaneously separate when subjected to vertical vibration, separation occurring when the ratio of particle inertia to fluid drag is sufficiently different between the component species of the mixture. Here, we describe how fluid-driven separation is influenced by magneto-Archimedes buoyancy, the additional buoyancy force experienced by a body immersed in a paramagnetic fluid when a strong inhomogeneous magnetic field is applied. In our experiments glass and bronze mixtures immersed in paramagnetic aqueous solutions of MnCl2 have been subjected to sinusoidal vertical vibration. In the absence of a magnetic field the separation is similar to that observed when the interstitial fluid is water. However, at modest applied magnetic fields, magneto-Archimedes buoyancy may balance the inertia/fluid-drag separation mechanism, or it may dominate the separation process. We identify the vibratory and magnetic conditions for four granular configurations, each having distinctive granular convection. Abrupt transitions between these states occur at well-defined values of the magnetic and vibrational parameters. In order to gain insight into the dynamics of the separation process we use computer simulations based on solutions of the Navier-Stokes' equations. The simulations reproduce the experimental results revealing the important role of convection and gap formation in the stability of the different states.

Resting energy expenditure in children with inflammatory bowel disease.

OBJECTIVES: There is controversy in the literature regarding the effect of inflammatory bowel disease (IBD) on resting energy expenditure (REE). In many cases this may have resulted from inappropriate adjustment of REE measurements to account for differences in body composition. This article considers how to appropriately adjust measurements of REE for differences in body composition between individuals with IBD. PATIENTS AND METHODS: Body composition, assessed via total body potassium to yield a measure of body cell mass (BCM), and REE measurements were performed in 41 children with Crohn disease and ulcerative colitis in the Royal Children's Hospital, Brisbane, Australia. Log-log regression was used to determine the power function to which BCM should be raised to appropriately adjust REE to account for differences in body composition between children. RESULTS: The appropriate value to "adjust" BCM was found to be 0.49, with a standard error of 0.10. CONCLUSIONS: Clearly, there is a need to adjust for differences in body composition, or at the very least body weight, in metabolic studies in children with IBD. We suggest that raising BCM to the power of 0.5 is both a numerically convenient and a statistically valid way of achieving this aim. Under circumstances in which the measurement of BCM is not available, raising body weight to the power of 0.5 remains appropriate. The important issue of whether REE is changed in cases of IBD can then be appropriately addressed.

Body change strategies in children: relationship to age and gender.

The "Body Image and Body Change Inventory Questionnaire" was administered to 958 students, aged 8.00-13.99 years, to determine the types of strategies used by children to accomplish changes in body size/shape. Each individual strategy score was compared for each gender and with respect to age. The girls' score for food restrictive practices was significantly higher than for other body change strategies. For the boys, the score for the use of food and exercise strategies to increase muscle size was significantly higher than all other practices except exercise strategies to increase body size. Both boys and girls reported the lowest scores for food and exercise strategies to increase body weight. The variance explained by age was small and not considered biologically significant. While the findings do not demonstrate a relationship between desire to change body size/shape and age, weight concerns should not be overlooked, as both genders seem concerned with keeping their body weight low. The different practices used by each gender demonstrate that different body image ideals hold for boys and girls.

Ligand binding by recombinant domains from insect ecdysone receptors.

The ligand binding domains (LBDs) from the EcR and USP proteins of four insect pests (Lucilia cuprina, Myzus persicae, Bemisia tabaci, Helicoverpa armigera) were purified as recombinant heterodimers. The K(d) values for [(3)H]-ponasterone A binding by LBD heterodimers that included the hinge regions (i.e., DE/F heterodimers) ranged 0.7-2.5 nM, with K(i) values for ecdysteroid and dibenzoylhydrazine ligands ranging from 0.1 nM to >448 microM. The K(d) and K(i) values for a recombinant H. armigera LBD heterodimer that lacked D-regions (i.e., an E/F heterodimer) were approximately 4 times higher than those for its DE/F counterpart. Rate constants were estimated for the L. cuprina LBD heterodimer. A fluorescein-inokosterone conjugate (K(i)~40 nM) was used to develop a novel binding assay based on fluorescence polarization. This assay, which ranked the affinity of competitor ecdysteroids in the same order as the [(3)H]-ponasterone A binding assay, is well suited to high-throughput screening. Ponasterone A had a higher affinity than muristerone A for the recombinant hemipteran LBD heterodimers, whereas the reverse was true for the recombinant dipteran one. The same preference was observed when these ligands were tested as inducers of ecdysone receptor-controlled gene expression in transfected mammalian cells. The binding data obtained in vitro using recombinant LBD heterodimers reflects the ability of agonists to induce transgene expression in recombinant mammalian cells, and can also reflect their efficacy as larvicides.

Interleukin-1beta induced activation of nuclear factor-kappab can be inhibited by novel pharmacological agents in osteoarthritis.

OBJECTIVES: To investigate the importance of activation of the transcription factor, nuclear factor-kappaB (NF-kappaB) by interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) in the pathogenesis of osteoarthritis (OA) and assess its suitability as a target for therapy by determining its role in the induction of the cytokine IL-6 and the degenerative enzymes, matrix metalloproteinase (MMP)-1 and MMP-3 in vitro. METHODS: Three distinct cellular models, derived from primary OA tissue, were employed, namely, fibroblast-like synoviocytes (OA-SF); co-cultures containing phenotypic macrophage-like and fibroblast-like cells (OA-COCUL); and primary OA synovial tissue explants (OA-EXP). These were treated with specific inhibitors of IL-1beta, TNF-alpha and NF-kappaB to assess their differential role in the production of pathologically relevant mediators, specifically IL-6, MMP-1, MMP-3 and the tissue inhibitor of metalloproteinases-1 (TIMP-1), which were quantified by enzyme-linked immunosorbent assay. RESULTS: Inhibition of NF-kappaB by a novel agent, RO100 at a dose of 0.1 microM, exerted significant (P < 0.05) repression of IL-6, MMP-1 and MMP-3 production in OA-SF. Notably, neither TIMP-1 production nor cell viability was significantly affected at the dose tested. These data were reproduced in OA-EXP, which might be considered as having greater physiological relevance. Interestingly, comparable efficacy was noted using IL-1beta and TNF-alpha neutralizing antibodies in OA-COCUL. CONCLUSIONS: We have demonstrated that a novel pharmacological inhibitor of NF-kappaB, RO100 inhibits pathological mediators of OA progression with equivalent efficacy as established IL-1beta and TNF-alpha neutralizing strategies. Our findings highlight a potential for developing NF-kappaB targeted therapeutics for positively regulating disease activity and improving clinical outcome in OA.

Media influence on the body image of children and adolescents.

To study the media messages portrayed to children, 925 students, from 9 to up to 14 years of age, completed "The Sociocultural Influences Questionnaire." The media section is the focus of this paper, and the responses from three questions were selected to examine the media's influence to be slimmer, increase weight, or increase muscle size. While the girls and boys exhibited different levels of agreement with each media influence, both genders disagreed that media messages were implying they should gain weight. This is in agreement with the belief that the media perpetuates the ideal of thinness and there is a negative stigma associated with being overweight.

An analphoid marker chromosome inv dup(15)(q26.1qter), detected during prenatal diagnosis and characterized via chromosome microdissection.

A small, mosaic, C-band negative marker chromosome was detected in amniocyte cultures during prenatal diagnosis due to advanced maternal age. Following spontaneous premature labor at 29 weeks gestation, a dysmorphic infant was delivered, with flat nasal bridge, short palpebral fissures, micrognathia, high forehead, low-set ears, telecanthus and corneal dystrophy. Additional folds of skin were present behind the neck, and feet, fingers and toes were abnormally long. The child died at age five days, after two days of renal failure. The origin of the marker chromosome was subsequently identified from a cord blood sample, via chromosome microdissection. Through reverse FISH, we found the marker to be an inverted duplication of the region 15q26.1-->qter. FISH with alphoid satellite probe was negative, while whole chromosome 15 paint was positive. Both ends of the marker chromosome were positive for the telomeric TTAGGG probe. These data, plus the G-banding pattern, identified the marker as an analphoid, inverted duplicated chromosome, lacking any conventional centromere. We discuss the etiology and clinical effects of this marker chromosome, comparing it to the few reported cases of "tetrasomy 15q" syndrome. We also discuss the possible mechanisms that are likely responsible for this neocentromere formation.

LcUSP, an ultraspiracle gene from the sheep blowfly, Lucilia cuprina: cDNA cloning, developmental expression of RNA and confirmation of function.

A DNA sequence corresponding to most of the DNA-binding domain of a Lucilia cuprina ultraspiracle protein (LcUSP) was amplified by PCR from genomic DNA and cloned. This cloned fragment was used to screen a L. cuprina cDNA library and to isolate a full-length LcUSP encoding sequence within a 3800-bp cDNA clone. The conceptually translated amino acid sequence of this open reading frame (467 amino acids) was used in alignment comparisons and phylogenetic analyses to reveal that LcUSP most closely resembles DmUSP relative to other known insect nuclear hormone receptors. An antisense RNA probe specific for the 5' end of Lcusp was used in ribonuclease protection assays to detect significant levels of Lcusp RNA throughout L. cuprina development. Highest levels were detected in embryos, late third instar larvae, pupae and adult females. This pattern parallels the pattern of expression observed for Dmusp RNAs during Drosophila melanogaster development. Finally, the LcUSP sequence was engineered for expression in mammalian cells and we now report that the cloned LcUSP is functional in vivo and can act as a partner for a chimeric L. cuprina ecdysone receptor to form an ecdysteroid-dependent transcription factor in mammalian cells.