25 research outputs found
The Effects of an Injury Prevention Program on Landing Biomechanics over Time
Background: Knowledge is limited regarding how long improvements in biomechanics remain after completion of a lower extremity injury prevention program. Purpose: To evaluate the effects of an injury prevention program on movement technique and peak vertical ground-reaction forces (VGRF) over time compared with a standard warm-up (SWU) program. Study Design: Controlled laboratory study. Methods: A total of 1104 incoming freshmen (age range, 17-22 years) at a military academy in the United States volunteered to participate. Participants were cluster-randomized by military company to either the Dynamic Integrated Movement Enhancement (DIME) injury prevention program or SWU. A random subsample of participants completed a standardized jump-landing task at each time point: immediately before the intervention (PRE), immediately after (POST), and 2 (POST2M), 4 (POST4M), 6 (POST6M), and 8 months (POST8M) after the intervention. VGRF data collected during the jump-landing task were normalized to body weight (%BW). The Landing Error Scoring System (LESS) was used to evaluate movement technique during the jump landing. The change scores (δ) for each variable (LESS, VGRF) between the group's average value at PRE and each time point were calculated. Separate univariate analyses of variance were performed to evaluate group differences. Results: The results showed a greater decrease in mean (±SD) VGRF in the DIME group compared with the SWU group at all retention time points: POST2M (SWU [δ%BW], -0.13 ± 0.82; DIME, -0.62 ± 0.91; P =.001), POST4M (SWU, -0.15 ± 0.98; DIME,-0.46 ± 0.64; P =.04), POST6M (SWU, -0.04 ± 0.96; DIME, -0.53 ± 0.83; P =.004), and POST8M (SWU, 0.38 ± 0.95; DIME, -0.11 ± 0.98; P =.003), but there was not a significant improvement in the DIME group between PRE and POST8M (δ%BW, -0.11 ± 0.98). No group differences in δ LESS were observed. Conclusion: The study findings demonstrated that an injury prevention program performed as a warm-up can reduce vertical ground-reaction forces compared with a standard warm-up but a maintenance program is likely necessary in order for continued benefit. Clinical Relevance: Injury prevention programs may need to be performed constantly, or at least every sport season, in order for participants to maintain the protective effects against injury
Effect of a lower extremity preventive training program on physical performance scores in military recruits
Exercise-based preventive training programs are designed to improve movement patterns associated with lower extremity injury risk; however, the impact of these programs on general physical fitness has not been evaluated. The purpose of this study was to compare fitness scores between participants in a preventive training program and a control group. One thousand sixty-eight freshmen from a U.S. Service Academy were cluster-randomized into either the intervention or control group during 6 weeks of summer training. The intervention group performed a preventive training program, specifically the Dynamic Integrated Movement Enhancement (DIME), which is designed to improve lower extremity movement patterns. The control group performed the Army Preparation Drill (PD), a warm-up designed to prepare soldiers for training. Main outcome measures were the Army Physical Fitness Test (APFT) raw and scaled (for age and sex) scores. Independent t tests were used to assess between-group differences. Multivariable logistic regression models were used to control for the influence of confounding variables. Dynamic Integrated Movement Enhancement group participants completed the APFT 2-mile run 20 seconds faster compared with the PD group (p, 0.001), which corresponded with significantly higher scaled scores (p, 0.001). Army Physical Fitness Test push-up scores were significantly higher in the DIME group (p = 0.041), but there were no significant differences in APFT sit-up scores. The DIME group had significantly higher total APFT scores compared with the PD group (p, 0.001). Similar results were observed in multivariable models after controlling for sex and body mass index (BMI). Committing time to the implementation of a preventive training program does not appear to negatively affect fitness test scores
The first Galaxy scale hunt for the youngest high-mass protostars
The origin of massive stars is a fundamental open issue in modern astrophysics. Pre-ALMA interferometric studies reveal precursors to early B to late O type stars with collapsing envelopes of 15–20?M? on 1000–3000?AU size-scales. To search for more massive envelopes we selected the most massive nearby young clumps from the ATLASGAL survey to study their protostellar content with ALMA. Our first results using the intermediate scales revealed by the ALMA ACA array providing 3–5?? angular resolution, corresponding to ?0.05 ? 0.1?pc size-scales, reveals a sample of compact objects. These massive, dense cores are on average two-times more massive than previous studies of similar types of objects. We expect that once the full survey is completed, it will provide a comprehensive view on the origin of the most massive star
Cross-reactivity of antibodies in some commercial deoxynivalenol test kits against some fusariotoxins.
<p>Cross-reactivity of antibodies in AGRAQUANT, DON EIA, VERATOX, ROSA LF-DONQ, and MYCONTROLDON designed for deoxynivalenol (DON) determination in food and feedstuffs was evaluated against nivalenol, 3-acetylDON, 15-acetylDON, de-epoxy metabolite 1 of DON, DON-3β-glucoside, T2-toxin, HT2-toxin, fusarenone X, diacetoxyscirpenol, verrucarol, and zearalenone. Cross-reactivity measurements were run in water using the 50% reduction of absorbance of the blank for ELISA kits or through direct DON determination upon using the standards of mycotoxins via ROSA LF-DONQ or MYCONTROLDON. For the tested toxin concentrations, all DON kits have low cross-reactivity toward diacetoxyscirpenol, T2-toxin, HT2-toxin, verrucarol, and zearalenone and moderate cross-reactivity toward 15-AcetylDON and fusarenone X. AGRAQUANT, DON EIA, and VERATOX kits showed high cross-reactivity in various ranking orders against DON-3-Glc, DOM-1, and 3AcDON. DON EIA showed also high cross-reactivity against nivalenol and fusarenone X. These mycotoxins could coexist in food or feedstuffs, and analytical results can be wrongly interpreted. Cross-reactivity does not allow checking the compliance with the legal norms, but it does allow an overall risk assessment for the consumers. Updating regularly the cross-reactivity evaluation of the produced batches is recommended for 3-acetylDON, nivalenol, DON-3-Glc, de-epoxy metabolite 1, and fusarenone X.</p></p
Deoxynivalenol loads in matched pair wheat samples in Belgium: comparison of ELISA VERATOX kit against liquid chromatography.
<p>A comparison of matched pairs deoxynivalenol (DON) loads in wheat samples via VERATOX for DON 5/5 performed by two laboratories against two liquid chromatographic methods (LC-MS/MS and HPLC-UV) used by two other laboratories was carried out using biometrical and sum of ranking differences (SRD) procedures. The Lin's Concordance correlation coefficients, the average discrepancies, the limits of agreement and the SRD between ELISA and reference values showed good overall agreement between VERATOX for DON 5/5 and reference methods for the two datasets. The VERATOX kits are valuable for quantitative screening and even for an initial exposure assessment in situations when there are practical or economical reasons not to use sophisticated methods such as HPLC or GC methods (with or without MS). However, networking of laboratories using this rapid method and laboratories with reference analytical methods should be encouraged.</p></p
Excitons and multi-excitons in single CdTe quantum dots probed by near-field spectroscopy
International audienc
Development and application of analytical methods adapted to the determination of mycotoxins in organic and conventional wheat
The aim of this study was to develop a multicomponent analytical method for the determination of deoxynivalenol (DON), ochratoxin A (OTA) and zearalenone (ZEN), nivalenol (NIV), 3-acetyl-DON (3-acDON), 15-acetyl-DON (15-acDON), zearalenol (ZOL) and citrinin (CIT) in wheat. It also aimed to survey the presence and amounts of DON, OTA and ZEN in Belgian conventionally and organically produced wheat grain and in wholemeal wheat flours. After solvent extraction, an anion-exchange column (SAX) was used to fix the acidic mycotoxins (OTA, CIT), whilst the neutral mycotoxins flowing through the SAX column were further purified by filtration on a MycoSep cartridge. OTA and CIT were then analysed by high-performance liquid chromatography (HPLC) using an isocratic flow and fluorescence detection, while the neutral mycotoxins were separated by a linear gradient and detected by double-mode (ultraviolet light fluorescence) detection. The average DON, ZEN and OTA recovery rates from spiked blank wheat flour were 92, 83 and 73% (RSDR = 12, 10 and 9%), respectively. Moreover, this method offered the respective detection limits of 50, 1.5 and 0.05 µg kg−1 and good agreement with reference methods and inter-laboratory comparison exercises. Organic and conventional wheat samples harvested in 2002 and 2003 in Belgium were analysed for DON, OTA and ZEN, while wholemeal wheat flour samples were taken from Belgian retail shops and analysed for OTA and DON. Conventional wheat tended to be more frequently contaminated with DON and ZEN than organic samples, the difference being more significant for ZEN in samples harvested in 2002. The mean OTA, DON and ZEA concentrations were 0.067, 675 and 75 µg kg−1 in conventional samples against 0.063, 285 and 19 µg kg−1 in organically produced wheat in 2002, respectively. Wheat samples collected in 2003 were less affected by DON and ZEN than the 2002 harvest. Organic wholemeal wheat flours were more frequently contaminated by OTA than conventional samples (p < 0.10). The opposite pattern was shown for DON, organic samples being more frequently contaminated than conventional flours (p < 0.10)
Viologen-Templated Arrays of Cucurbit[7]uril-Modified Iron-Oxide Nanoparticles
International audienceMagnetic and fluorescent assemblies of iron-oxide nanoparticles (NPs) were constructed by threading a viologen-based ditopic ligand, DPV2+, into the cavity of cucurbituril (CB[7]) macrocycles adsorbed on the surface of the NPs. Evidence for the formation of 1:2 inclusion complexes that involve DPV2+ and two CB[7] macrocycles was first obtained in solution by 1H NMR and emission spectroscopy. DPV2+ was found to induce self-assembly of nanoparticle arrays (DPV2+⊂CB[7]NPs) by bridging CB[7] molecules on different NPs. The resulting viologen-crosslinked iron-oxide nanoparticles exhibited increased saturation magnetization and emission properties. This facile supramolecular approach to NP self-assembly provides a platform for the synthesis of smart and innovative materials that can achieve a high degree of functionality and complexity and that are needed for a wide range of applications