Flux ropes in the Hermean magnetotail: Distribution, properties, and formation

An automated method was applied to identify magnetotail flux rope encounters in MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) magnetometer data. The method identified significant deflections of the northâ south component of the magnetic field coincident with enhancements in the total field or dawnâ dusk component. Two hundred fortyâ eight flux ropes are identified that possess wellâ defined minimum variance analysis (MVA) coordinate systems, with clear rotations of the field. Approximately 30% can be well approximated by the cylindrically symmetric, linearly forceâ free model. Flux ropes are most common moving planetward, in the postmidnight sector. Observations are intermittent, with the majority (61%) of plasma sheet passages yielding no flux ropes; however, the peak rate of flux ropes during a reconnection episode is â ¼5 minâ 1. Overall, the peak postmidnight rate is â ¼0.25 minâ 1. Only 25% of flux ropes are observed in isolation. The radius of flux ropes is comparable to the ion inertial length within Mercury’s magnetotail plasma sheet. No clear statistical separation is observed between tailward and planetward moving flux ropes, suggesting the nearâ Mercury neutral line (NMNL) is highly variable. Flux ropes are more likely to be observed if the preceding lobe field is enhanced over background levels. A very weak correlation is observed between the flux rope core field and the preceding lobe field orientation; a stronger relationship is found with the orientation of the field within the plasma sheet. The core field strength measured is â ¼6 times stronger than the local dawnâ dusk plasma sheet magnetic field.Key PointsTwo hundred fortyâ eight flux ropes identified in Mercury’s magnetotail (74 cylindrical and linearly forceâ free)Flux ropes most commonly observed by MESSENGER postmidnight, moving planetwardFlux ropes observed intermittently, but most often when the preceding lobe field is enhancedPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138858/1/jgra53697_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138858/2/jgra53697.pd

Spatial distribution of Mercury’s flux ropes and reconnection fronts: MESSENGER observations

We perform a statistical study of flux ropes and reconnection fronts based on MErcury Surface, Space ENviroment, GEochemistry, and Ranging (MESSENGER) magnetic field and plasma observations to study the implications for the spatial distribution of reconnection sites in Mercury’s near magnetotail. The results show important differences of temporal and spatial distributions as compared to Earth. We have surveyed the plasma sheet crossings between −2 RM and −3 RM downtail from the planet, i.e., the location of Near‐Mercury Neutral Line (NMNL). Plasma sheets were defined to be regions with β ≥ 0.5. Using this definition, 39 flux ropes and 86 reconnection fronts were identified in the plasma sheet. At Mercury, the distributions of flux ropes and reconnection fronts show clear dawn‐dusk asymmetry with much higher occurrence rate on the dawnside plasma sheet than on the duskside. This suggests that magnetic reconnection in Mercury’s magnetotail occurs more frequently in the dawnside than in the duskside plasma sheet, which is different than the observations in Earth’s magnetotail showing more reconnection signatures in the duskside plasma sheet. The distribution of plasma sheet thickness shows that plasma sheet near the midnight is the thinnest part and does not show obvious asymmetry. Thus, the reasons that cause magnetic reconnection to preferentially occur on the dawnside of the magnetotail at Mercury may not be the plasma sheet thickness and require further study. The peak occurrence rates of flux ropes and reconnection fronts in Mercury’s plasma sheet are ~ 60 times higher than that of Earth’s values, which we interpret to be due to the highly variable magnetospheric conditions at Mercury. Such higher occurrence rate of magnetic reconnection would generate more plasma flows in the dawnside plasma sheet than in the duskside. These plasma flows would mostly brake and initiate the substorm dipolarization on the postmidnight sector at Mercury rather than the premidnight susbtorm onset location at Earth.Key PointsOccurrence rate of FRs and RFs at Mercury is ~ 60 times higher than at Earth, due to the variable magnetospheric conditions at MercuryMagnetic reconnection occurs more frequently in the dawnside than in the duskside in Mercury’s plasma sheet, opposite to Earth’s resultsPlasma flows would brake and initiate dipolarizations on the postmidnight sector at Mercury different to the premidnight locations at EarthPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134095/1/jgra52821.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134095/2/jgra52821_am.pd

Viral quasispecies inference from 454 pyrosequencing

10.1186/1471-2105-14-355BMC Bioinformatics141-BBMI

ToyBox Study Malaysia: improving healthy energy balance and obesity-related behaviours among pre-schoolers in Malaysia

The prevalence of childhood overweight and obesity is increasing in Malaysia and currently nearly 10% of children aged between 6 months and 12 years are overweight and almost 12% are obese. Early interventions to prevent excess weight gain are needed. ToyBox Study Malaysia is a feasibility project, funded by the Medical Research Council Newton-Ungku Omar Fund, to assess the practicalities of adapting the existing European ToyBox Study intervention programme to the Malaysian kindergarten setting. The main aims of all ToyBox programmes are related to improving four key energy balance-related behaviours, namely drinking water, eating healthy snacks and meals, reducing sedentary behaviour and increasing physical activity. Using stratified sampling, the ToyBox Study Malaysia intervention will be delivered and compared to usual practice by assessing behaviour, physical activity and health-related outcomes as measured by questionnaires, accelerometry and anthropometry. It is hoped that the evidence-based ToyBox Study Malaysia will help to achieve healthier energy balance-related behaviours in the children and their families and provide lifelong benefits to health. This article provides information on the dietary patterns, physical activity levels and prevalence of overweight and obesity in Malaysian children, and the approach of the ToyBox Study Malaysia

A Statistical Study of the Force Balance and Structure in the Flux Ropes in Mercury’s Magnetotail

This study presents a statistical investigation of the force balance and structures in the flux ropes in Mercury’s magnetotail plasma sheet by using the measurements of MErcury Surface, Space ENviroment, GEochemistry, and Ranging (MESSENGER). One hundred sixty-eight flux ropes were identified from the 14 hot seasons of MESSENGER from 11 March 2011 to 30 April 2015, and 143 of them show clear magnetic field enhancements with the core field being -20% higher than the background magnetic field. The investigation on the force balance of these 143 flux ropes shows that magnetic pressure gradient force cannot be solely balanced by magnetic tension force, implying that thermal plasma pressure gradient force cannot be neglected in the flux ropes. We employ a non-force-free model considering the contribution of thermal pressure to resolve the physical properties of flux ropes in Mercury’s magnetotail. Twenty-eight flux ropes are obtained through the fitting to the non-force-free model. The flux ropes are found to be consistent with the flattened structures, in which the mean semimajor is -851 km and semiminor is -333 km, both are several times the local proton inertial length. The average core field is estimated to be -57.5 nT, and flux content is -0.019 MWb, much larger than the previous results obtained from force-free flux rope model. The importance of thermal pressure gradient in the force balance of the flux ropes and the flattened structure indicates that the flux ropes in Mercury’s magnetotail plasma sheet are mostly in early stage of the evolution, and still contain enough plasma to affect their magnetic structures.Key PointsThermal pressure gradient is significant for the flux ropes in Mercury’s magnetotailNon-force-free modeling reveals the flatten structure and much higher magnetic flux of the flux ropes different from the previous studiesFlux ropes in this study should be in their early stage of evolution and could be strongly affected by thermal pressurePeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151305/1/jgra55044_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151305/2/jgra55044.pd

Process evaluation of a kindergarten-based intervention for obesity prevention in early childhood: the Toybox study Malaysia

BackgroundToybox is a kindergarten-based intervention program that targets sedentary behavior, snacking and drinking habits, as well as promoting physical activity in an effort to improve healthy energy balance-related behaviors among children attending kindergartens in Malaysia. The pilot of this program was conducted as a randomized controlled trial (RCT) involving 837 children from 22 intervention kindergartens and 26 control kindergartens respectively. This paper outlines the process evaluation of this intervention.MethodsWe assessed five process indicators: recruitment, retention, dosage, fidelity, and satisfaction for the Toybox program. Data collection was conducted via teachers’ monthly logbooks, post-intervention feedback through questionnaires, and focus group discussions (FGD) with teachers, parents, and children. Data were analyzed using quantitative and qualitative data analysis methods.ResultsA total of 1072 children were invited. Out of the 1001 children whose parents consented to join, only 837 completed the program (Retention rate: 88.4%). As high as 91% of the 44 teachers and their assistants engaged positively in one or more of the process evaluation data collection methods. In terms of dosage and fidelity, 76% of parents had received newsletters, tip cards, and posters at the appropriate times. All teachers and their assistants felt satisfied with the intervention program. However, they also mentioned some barriers to its implementation, including the lack of suitable indoor environments to conduct activities and the need to make kangaroo stories more interesting to captivate the children’s attention. As for parents, 88% of them were satisfied with the family-based activities and enjoyed them. They also felt that the materials provided were easy to understand and managed to improve their knowledge. Lastly, the children showed positive behaviors in consuming more water, fruits, and vegetables.ConclusionsThe Toybox program was deemed acceptable and feasible to implement by the parents and teachers. However, several factors need to be improved before it can be expanded and embedded as a routine practice across Malaysia

Multiple Traits for People Identification

Present biometric systems mostly rely on a single physical or behavioral feature for either identification or verification. However, day to day use of single biometries in massive or uncontrolled scenarios still has several shortcomings. These can be due to complex or unstable hardware settings, to changing environmental conditions or even to immature software procedures: some classification problems are intrinsically hard to solve. Possible spoofing of single biometric features is an additional issue. Last but not least, some features may occasionally lack the requisite of universality. As a consequence, biometric systems based on a single feature often have poor reliability, especially in applications where high security is needed. Multimodal systems, i.e., systems that concurrently exploit multiple features, are a possible way to achieve improved effectiveness and reliability. There are several issues that must be addressed when designing such a system, including the choice of the set of biometric features, the normalization method, the integration schema and the fusion process, and the use of a measure of reliability for each subsystem on a single response basis. This chapter describes the state of the art regarding such issues and sketches some suggestions for future work

Population Genomics: Whole-Genome Analysis of Polymorphism and Divergence in Drosophila simulans

The population genetic perspective is that the processes shaping genomic variation can be revealed only through simultaneous investigation of sequence polymorphism and divergence within and between closely related species. Here we present a population genetic analysis of Drosophila simulans based on whole-genome shotgun sequencing of multiple inbred lines and comparison of the resulting data to genome assemblies of the closely related species, D. melanogaster and D. yakuba. We discovered previously unknown, large-scale fluctuations of polymorphism and divergence along chromosome arms, and significantly less polymorphism and faster divergence on the X chromosome. We generated a comprehensive list of functional elements in the D. simulans genome influenced by adaptive evolution. Finally, we characterized genomic patterns of base composition for coding and noncoding sequence. These results suggest several new hypotheses regarding the genetic and biological mechanisms controlling polymorphism and divergence across the Drosophila genome, and provide a rich resource for the investigation of adaptive evolution and functional variation in D. simulans