Characterization of flax germplasm for resistance to fusarium wilt

Non-Peer ReviewedFusarium wilt of flax (Linum usitatissimum L.) caused by Fusarium oxysporum f. sp. lini (Fol) is an economically important disease that can result in severe yield losses. Due to the pathogen’s ability to survive in soil for long periods, it is essential to identify fusarium wilt resistant flax varieties. The objectives of the study were to phenotype and compare a recombinant inbred line (RIL) population of flax in a controlled environment and in field wilt nurseries. Disease reaction of a subset (160) of RIL lines developed from cultivars ‘Aurore’ (moderately resistant) and ‘Oliver’ (susceptible) was assessed under controlled environment conditions to two Fol isolates. Disease severity was determined and the area under the disease progress curve (AUDPC) was calculated. The population varied in response from resistant to highly susceptible, indicating that resistant to wilt was probably polygenic. Twenty-eight days after inoculation, 14% and 5% of the RILs were severely wilted (scores of 8 and 9, with isolates 131 and 81, respectively). Plant height was negatively correlated with AUDPC (r2= -0.13155 for 131 and r2=-0.29841 for 81). Similarly, in the field in wilt nurseries, at Saskatoon and Morden, evaluation of the full set of 200 RILs, the disease reaction varied from resistant to susceptible, with 21% and 42% of RILs severely wilted (rated 8 and 9) at each site at the green boll stage. The results from the two locations were significantly different, although moderately correlated (r2=0.6127). The 160 RILs in controlled environment inoculated with isolates 131 and 81 showed a higher correlation for disease severity at 28 days after inoculation, with the wilt nursery in Saskatoon (r= 0.40028 and r2=0.38046) as compared to Morden (r2=0.33016 and r2=0.21140) at green boll stage. Differences in environmental and experimental conditions (such as seeding date) at the two locations, as well as different Fol strains in the soil combined with the subjectivity of the grading system may explain the differences between locations

No Evidence for a Cumulative Impact Effect on Concussion Injury Threshold

Recent studies using a helmet-based accelerometer system (Head Impact Telemetry System [HITS]) have demonstrated that concussions result from a wide range of head impact magnitudes. Variability in concussion thresholds has been proposed to result from the cumulative effect of non-concussive head impacts prior to injury. We used the HITS to collect biomechanical data representing >100,000 head impacts in 95 high school football players over 4 years. The cumulative impact histories prior to 20 concussive impacts in 19 athletes were compared to the cumulative impact histories prior to the three largest magnitude non-concussive head impacts in the same athletes. No differences were present in any impact history variable between the concussive and non-concussive high magnitude impacts. These analyses included the number of head impacts, cumulative HIT severity profile value, cumulative linear acceleration, and cumulative rotational acceleration during the same practice or game session, as well as over the 30-min and 1 week preceding these impacts. Our data do not support the proposal that impact volume or intensity influence concussion threshold in high school football athletes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90490/1/neu-2E2011-2E1910.pd

Generalized monotonic functional mixed models with application to modelling normal tissue complications

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73586/1/j.1467-9876.2007.00606.x.pd

Post-Concussion Cognitive Declines and Symptomatology Are Not Related to Concussion Biomechanics in High School Football Players

Concussion is a major public health concern with nearly 4 million injuries occurring each year in the United States. In the acute post-injury stage, concussed individuals demonstrate cognitive function and motor control declines as well as reporting increased symptoms. Researchers have hypothesized that the severity of these impairments is related to impact magnitude. Using the Head Impact Telemetry System (HITS) to record head impact biomechanics, we sought to correlate pre- and post-concussive impact characteristics with declines in cognitive performance and increases in concussion-related symptoms. Over four seasons, 19 high school football athletes wearing instrumented helmets sustained 20 diagnosed concussions. Each athlete completed a baseline computer-based symptom and cognitive assessment during the pre-season and a post-injury assessment within 24-h of injury. Correlational analyses identified no significant relationships between symptoms and cognitive performance change scores and impact biomechanics (i.e., time from session start until injury, time from the previous impact, peak linear acceleration, peak rotational acceleration, and HIT severity profile [HITsp]). Nor were there any significant relationships between change scores and the number of impacts, cumulative linear acceleration, cumulative rotational acceleration, or cumulative HITsp values associated with all impacts prior to or following the injury. This investigation is the first to examine the relationship between concussion impact characteristics, including cumulative impact profiles, and post-morbid outcomes in high school athletes. There appears to be no association between head impact biomechanics and post-concussive outcomes. As such, the use of biomechanical variables to predict injury severity does not appear feasible at this time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90455/1/neu-2E2011-2E1905.pd

Cumulative Head Impact Burden in High School Football

Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). The 4-year investigation resulted in 101,994 impacts collected across 190 practice sessions and 50 games. The number of impacts per 14-week season varied by playing position and starting status, with the average player sustaining 652 impacts. Linemen sustained the highest number of impacts per season (868); followed by tight ends, running backs, and linebackers (619); then quarterbacks (467); and receivers, cornerbacks, and safeties (372). Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7-rad/sec2 and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90454/1/neu-2E2011-2E1825.pd

Shotgun metagenomic analysis of microbial communities from the Loxahatchee nature preserve in the Florida Everglades.

BackgroundCurrently, much is unknown about the taxonomic diversity and the mechanisms of methane metabolism in the Florida Everglades ecosystem. The Loxahatchee National Wildlife Refuge is a section of the Florida Everglades that is almost entirely unstudied in regard to taxonomic profiling. This short report analyzes the metagenome of soil samples from this Refuge to investigate the predominant taxa, as well as the abundance of genes involved in environmentally significant metabolic pathways related to methane production (nitrogen fixation and dissimilatory sulfite reduction).MethodsShotgun metagenomic sequencing using the Illumina platform was performed on 17 soil samples from four different sites within the Loxahatchee National Wildlife Refuge, and underwent quality control, assembly, and annotation. The soil from each sample was tested for water content and concentrations of organic carbon and nitrogen.ResultsThe three most common phyla of bacteria for every site were Actinobacteria, Acidobacteria, and Proteobacteria; however, there was variation in relative phylum composition. The most common phylum of Archaea was Euryarchaeota for all sites. Alpha and beta diversity analyses indicated significant congruity in taxonomic diversity in most samples from Sites 1, 3, and 4 and negligible congruity between Site 2 and the other sites. Shotgun metagenomic sequencing revealed the presence of biogeochemical biomarkers of particular interest (e.g., mrcA, nifH, and dsrB) within the samples. The normalized abundances of mcrA, nifH, and dsrB exhibited a positive correlation with nitrogen concentration and water content, and a negative correlation with organic carbon concentration.ConclusionThis Everglades soil metagenomic study allowed examination of wetlands biological processes and showed expected correlations between measured organic constituents and prokaryotic gene frequency. Additionally, the taxonomic profile generated gives a basis for the diversity of prokaryotic microbial life throughout the Everglades

The Concussion Recognition Tool 5th Edition (CRT5): Background and rationale

The Concussion Recognition Tool 5 (CRT5) is the most recent revision of the Pocket Sport Concussion Assessment Tool 2 that was initially introduced by the Concussion in Sport Group in 2005. The CRT5 is designed to assist non-medically trained individuals to recognise the signs and symptoms of possible sport-related concussion and provides guidance for removing an athlete from play/sport and to seek medical attention. This paper presents the development of the CRT5 and highlights the differences between the CRT5 and prior versions of the instrument