2,411 research outputs found
Evaluating Active U: an Internet-mediated physical activity program.
Background:
Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U) was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition.
Methods:
This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load.
Results:
Overall, 7,483 individuals registered with the Active U website (≈16% of eligible), and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI < 25 were more likely to meet their weekly physical activity goals, and average rate of meeting goals was higher among participants who joined a competitive team compared to those who participated individually (IRR = 1.28, P < .001).
Conclusion:
Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months
Maternal corticotropin-releasing hormone is associated with LEP DNA methylation at birth and in childhood: an epigenome-wide study in Project Viva
BackgroundCorticotropin-releasing hormone (CRH) plays a central role in regulating the secretion of cortisol which controls a wide range of biological processes. Fetuses overexposed to cortisol have increased risks of disease in later life. DNA methylation may be the underlying association between prenatal cortisol exposure and health effects. We investigated associations between maternal CRH levels and epigenome-wide DNA methylation of cord blood in offsprings and evaluated whether these associations persisted into mid-childhood.MethodsWe investigated mother-child pairs enrolled in the prospective Project Viva pre-birth cohort. We measured DNA methylation in 257 umbilical cord blood samples using the HumanMethylation450 Bead Chip. We tested associations of maternal CRH concentration with cord blood cells DNA methylation, adjusting the model for maternal age at enrollment, education, maternal race/ethnicity, maternal smoking status, pre-pregnancy body mass index, parity, gestational age at delivery, child sex, and cell-type composition in cord blood. We further examined the persistence of associations between maternal CRH levels and DNA methylation in children's blood cells collected at mid-childhood (n = 239, age: 6.7-10.3 years) additionally adjusting for the children's age at blood drawn.ResultsMaternal CRH levels are associated with DNA methylation variability in cord blood cells at 96 individual CpG sites (False Discovery Rate <0.05). Among the 96 CpG sites, we identified 3 CpGs located near the LEP gene. Regional analyses confirmed the association between maternal CRH and DNA methylation near LEP. Moreover, higher maternal CRH levels were associated with higher blood-cell DNA methylation of the promoter region of LEP in mid-childhood (P < 0.05, β = 0.64, SE = 0.30).ConclusionIn our cohort, maternal CRH was associated with DNA methylation levels in newborns at multiple loci, notably in the LEP gene promoter. The association between maternal CRH and LEP DNA methylation levels persisted into mid-childhood
Gene expression and splicing alterations analyzed by high throughput RNA sequencing of chronic lymphocytic leukemia specimens.
BackgroundTo determine differentially expressed and spliced RNA transcripts in chronic lymphocytic leukemia specimens a high throughput RNA-sequencing (HTS RNA-seq) analysis was performed.MethodsTen CLL specimens and five normal peripheral blood CD19+ B cells were analyzed by HTS RNA-seq. The library preparation was performed with Illumina TrueSeq RNA kit and analyzed by Illumina HiSeq 2000 sequencing system.ResultsAn average of 48.5 million reads for B cells, and 50.6 million reads for CLL specimens were obtained with 10396 and 10448 assembled transcripts for normal B cells and primary CLL specimens respectively. With the Cuffdiff analysis, 2091 differentially expressed genes (DEG) between B cells and CLL specimens based on FPKM (fragments per kilobase of transcript per million reads and false discovery rate, FDR q < 0.05, fold change >2) were identified. Expression of selected DEGs (n = 32) with up regulated and down regulated expression in CLL from RNA-seq data were also analyzed by qRT-PCR in a test cohort of CLL specimens. Even though there was a variation in fold expression of DEG genes between RNA-seq and qRT-PCR; more than 90 % of analyzed genes were validated by qRT-PCR analysis. Analysis of RNA-seq data for splicing alterations in CLL and B cells was performed by Multivariate Analysis of Transcript Splicing (MATS analysis). Skipped exon was the most frequent splicing alteration in CLL specimens with 128 significant events (P-value <0.05, minimum inclusion level difference >0.1).ConclusionThe RNA-seq analysis of CLL specimens identifies novel DEG and alternatively spliced genes that are potential prognostic markers and therapeutic targets. High level of validation by qRT-PCR for a number of DEG genes supports the accuracy of this analysis. Global comparison of transcriptomes of B cells, IGVH non-mutated CLL (U-CLL) and mutated CLL specimens (M-CLL) with multidimensional scaling analysis was able to segregate CLL and B cell transcriptomes but the M-CLL and U-CLL transcriptomes were indistinguishable. The analysis of HTS RNA-seq data to identify alternative splicing events and other genetic abnormalities specific to CLL is an added advantage of RNA-seq that is not feasible with other genome wide analysis
Rudimentary G-Quadruplex-Based Telomere Capping In Saccharomyces Cerevisiae
Telomere capping conceals chromosome ends from exonucleases and checkpoints, but the full range of capping mechanisms is not well defined. Telomeres have the potential to form G-quadruplex (G4) DNA, although evidence for telomere G4 DNA function in vivo is limited. In budding yeast, capping requires the Cdc13 protein and is lost at nonpermissive temperatures in cdc13-1 mutants. Here, we use several independent G4 DNA-stabilizing treatments to suppress cdc13-1 capping defects. These include overexpression of three different G4 DNA binding proteins, loss of the G4 DNA unwinding helicase Sgs1, or treatment with small molecule G4 DNA ligands. In vitro, we show that protein-bound G4 DNA at a 3\u27 overhang inhibits 5\u27-\u3e 3\u27 resection of a paired strand by exonuclease I. These findings demonstrate that, at least in the absence of full natural capping, G4 DNA can play a positive role at telomeres in vivo
Chalcogenide Glass-on-Graphene Photonics
Two-dimensional (2-D) materials are of tremendous interest to integrated
photonics given their singular optical characteristics spanning light emission,
modulation, saturable absorption, and nonlinear optics. To harness their
optical properties, these atomically thin materials are usually attached onto
prefabricated devices via a transfer process. In this paper, we present a new
route for 2-D material integration with planar photonics. Central to this
approach is the use of chalcogenide glass, a multifunctional material which can
be directly deposited and patterned on a wide variety of 2-D materials and can
simultaneously function as the light guiding medium, a gate dielectric, and a
passivation layer for 2-D materials. Besides claiming improved fabrication
yield and throughput compared to the traditional transfer process, our
technique also enables unconventional multilayer device geometries optimally
designed for enhancing light-matter interactions in the 2-D layers.
Capitalizing on this facile integration method, we demonstrate a series of
high-performance glass-on-graphene devices including ultra-broadband on-chip
polarizers, energy-efficient thermo-optic switches, as well as graphene-based
mid-infrared (mid-IR) waveguide-integrated photodetectors and modulators
Complete chloroplast genome sequence of Holoparasite Cistanche Deserticola (Orobanchaceae) reveals gene loss and horizontal gene transfer from Its host Haloxylon Ammodendron (Chenopodiaceae)
The central function of chloroplasts is to carry out photosynthesis, and its gene content and structure are highly conserved across land plants. Parasitic plants, which have reduced photosynthetic ability, suffer gene losses from the chloroplast (cp) genome accompanied by the relaxation of selective constraints. Compared with the rapid rise in the number of cp genome sequences of photosynthetic organisms, there are limited data sets from parasitic plants. The authors report the complete sequence of the cp genome of Cistanche deserticola, a holoparasitic desert species belonging to the family Orobanchaceae
Asymmetric triplex metallohelices with high and selective activity against cancer cells
Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.
At a glanc
Measurement of Cardiac Mechanical Function in Isolated Ventricular Myocytes from Rats and Mice by Computerized Video-Based Imaging
Isolated adult cardiac ventricular myocytes have been a useful model for cardiovascular research for more than 20 years. With the recent advances in cellular physiology and transgenic techniques, direct measurement of isolated ventricular myocyte mechanics is becoming an increasingly important technique in cardiac physiology that provides fundamental information on excitation-contraction coupling of the heart, either in drug intervention or pathological states. The goal of this article is to describe the isolation of ventricular myocytes from both rats and mice, and the use of real-time beat-to-beat simultaneous recording of both myocyte contraction and intracellular Ca(2+) transient
Does flip-flop style footwear modify ankle biomechanics and foot loading patterns?
Background
Flip-flops are an item of footwear, which are rubber and loosely secured across the dorsal fore-foot. These are popular in warm climates; however are widely criticised for being detrimental to foot health and potentially modifying walking gait. Contemporary alternatives exist including FitFlop, which has a wider strap positioned closer to the ankle and a thicker, ergonomic, multi-density midsole. Therefore the current study investigated gait modifications when wearing flip-flop style footwear compared to barefoot walking. Additionally walking in a flip-flop was compared to that FitFlop alternative.
Methods
Testing was undertaken on 40 participants (20 male and 20 female, mean ± 1 SD age 35.2 ± 10.2 years, B.M.I 24.8 ± 4.7 kg.m−2). Kinematic, kinetic and electromyographic gait parameters were collected while participants walked through a 3D capture volume over a force plate with the lower limbs defined using retro-reflective markers. Ankle angle in swing, frontal plane motion in stance and force loading rates at initial contact were compared. Statistical analysis utilised ANOVA to compare differences between experimental conditions.
Results
The flip-flop footwear conditions altered gait parameters when compared to barefoot. Maximum ankle dorsiflexion in swing was greater in the flip-flop (7.6 ± 2.6°, p = 0.004) and FitFlop (8.5 ± 3.4°, p < 0.001) than barefoot (6.7 ± 2.6°). Significantly higher tibialis anterior activation was measured in terminal swing in FitFlop (32.6%, p < 0.001) and flip-flop (31.2%, p < 0.001) compared to barefoot. A faster heel velocity toward the floor was evident in the FitFlop (−.326 ± .068 m.s−1, p < 0.001) and flip-flop (−.342 ± .074 m.s−1, p < 0.001) compared to barefoot (−.170 ± .065 m.s−1). The FitFlop reduced frontal plane ankle peak eversion during stance (−3.5 ± 2.2°) compared to walking in the flip-flop (−4.4 ± 1.9°, p = 0.008) and barefoot (−4.3 ± 2.1°, p = 0.032). The FitFlop more effectively attenuated impact compared to the flip-flop, reducing the maximal instantaneous loading rate by 19% (p < 0.001).
Conclusions
Modifications to the sagittal plane ankle angle, frontal plane motion and characteristics of initial contact observed in barefoot walking occur in flip-flop footwear. The FitFlop may reduce risks traditionally associated with flip-flop footwear by reducing loading rate at heel strike and frontal plane motion at the ankle during stance
Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV
A search for pair-produced charged Higgs bosons is performed with the L3
detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV,
corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a
charm and a strange quark or into a tau lepton and its associated neutrino are
considered. The observed events are consistent with the expectations from
Standard Model background processes. A lower limit of 65.5 GeV on the charged
Higgs mass is derived at 95 % confidence level, independent of the decay
branching ratio Br(H^{+/-} -> tau nu)
- …
