Screening for Speech and Language Delay and Disorders in Children 5 Years or Younger: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Children with speech and language difficulties are at risk for learning and behavioral problems. Objective: To review the evidence on screening for speech and language delay or disorders in children 5 years or younger to inform the US Preventive Services Task Force. Data Sources: PubMed/MEDLINE, Cochrane Library, PsycInfo, ERIC, Linguistic and Language Behavior Abstracts (ProQuest), and trial registries through January 17, 2023; surveillance through November 24, 2023. Study Selection: English-language studies of screening test accuracy, trials or cohort studies comparing screening vs no screening; randomized clinical trials (RCTs) of interventions. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, study quality, and data extraction; results were narratively summarized. Main Outcomes and Measures: Screening test accuracy, speech and language outcomes, school performance, function, quality of life, and harms. Results: Thirty-eight studies in 41 articles were included (N = 9006). No study evaluated the direct benefits of screening vs no screening. Twenty-one studies (n = 7489) assessed the accuracy of 23 different screening tools that varied with regard to whether they were designed to be completed by parents vs trained examiners, and to screen for global (any) language problems vs specific skills (eg, expressive language). Three studies assessing parent-reported tools for expressive language skills found consistently high sensitivity (range, 88%-93%) and specificity (range, 88%-85%). The accuracy of other screening tools varied widely. Seventeen RCTs (n = 1517) evaluated interventions for speech and language delay or disorders, although none enrolled children identified by routine screening in primary care. Two RCTs evaluating relatively intensive parental group training interventions (11 sessions) found benefit for different measures of expressive language skills, and 1 evaluating a less intensive intervention (6 sessions) found no difference between groups for any outcome. Two RCTs (n = 76) evaluating the Lidcombe Program of Early Stuttering Intervention delivered by speech-language pathologists featuring parent training found a 2.3% to 3.0% lower proportion of syllables stuttered at 9 months compared with the control group when delivered in clinic and via telehealth, respectively. Evidence on other interventions was limited. No RCTs reported on the harms of interventions. Conclusions and Relevance: No studies directly assessed the benefits and harms of screening. Some parent-reported screening tools for expressive language skills had reasonable accuracy for detecting expressive language delay. Group parent training programs for speech delay that provided at least 11 parental training sessions improved expressive language skills, and a stuttering intervention delivered by speech-language pathologists reduced stuttering frequency.

An Instrumented Mouthguard for Real-Time Measurement of Head Kinematics under a Large Range of Sport Specific Accelerations.

BACKGROUND: Head impacts in sports can produce brain injuries. The accurate quantification of head kinematics through instrumented mouthguards (iMG) can help identify underlying brain motion during injurious impacts. The aim of the current study is to assess the validity of an iMG across a large range of linear and rotational accelerations to allow for on-field head impact monitoring. METHODS: Drop tests of an instrumented helmeted anthropometric testing device (ATD) were performed across a range of impact magnitudes and locations, with iMG measures collected concurrently. ATD and iMG kinematics were also fed forward to high-fidelity brain models to predict maximal principal strain. RESULTS: The impacts produced a wide range of head kinematics (16-171 g, 1330-10,164 rad/s2 and 11.3-41.5 rad/s) and durations (6-18 ms), representing impacts in rugby and boxing. Comparison of the peak values across ATD and iMG indicated high levels of agreement, with a total concordance correlation coefficient of 0.97 for peak impact kinematics and 0.97 for predicted brain strain. We also found good agreement between iMG and ATD measured time-series kinematic data, with the highest normalized root mean squared error for rotational velocity (5.47 ± 2.61%) and the lowest for rotational acceleration (1.24 ± 0.86%). Our results confirm that the iMG can reliably measure laboratory-based head kinematics under a large range of accelerations and is suitable for future on-field validity assessments.

Screening for Obstructive Sleep Apnea in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Obstructive sleep apnea (OSA) is associated with adverse health outcomes. Objective: To review the evidence on screening for OSA in asymptomatic adults or those with unrecognized OSA symptoms to inform the US Preventive Services Task Force. Data Sources: PubMed/MEDLINE, Cochrane Library, Embase, and trial registries through August 23, 2021; surveillance through September 23, 2022. Study Selection: English-language studies of screening test accuracy, randomized clinical trials (RCTs) of screening or treatment of OSA reporting health outcomes or harms, and systematic reviews of treatment reporting changes in blood pressure and apnea-hypopnea index (AHI) scores. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality. Meta-analysis of intervention trials. Main Outcomes and Measures: Test accuracy, excessive daytime sleepiness, sleep-related and general health-related quality of life (QOL), and harms. Results: Eighty-six studies were included (N = 11 051). No study directly compared screening with no screening. Screening accuracy of the Multivariable Apnea Prediction score followed by unattended home sleep testing for detecting severe OSA syndrome (AHI ≥30 and Epworth Sleepiness Scale [ESS] score >10) measured as the area under the curve in 2 studies (n = 702) was 0.80 (95% CI, 0.78 to 0.82) and 0.83 (95% CI, 0.77 to 0.90). Five studies assessing the accuracy of other screening tools were heterogeneous and results were inconsistent. Compared with inactive control, positive airway pressure was associated with a significant improvement in ESS score from baseline (pooled mean difference, -2.33 [95% CI, -2.75 to -1.90]; 47 trials; n = 7024), sleep-related QOL (standardized mean difference, 0.30 [95% CI, 0.19 to 0.42]; 17 trials; n = 3083), and general health-related QOL measured by the 36-Item Short Form Health Survey (SF-36) mental health component summary score change (pooled mean difference, 2.20 [95% CI, 0.95 to 3.44]; 15 trials; n = 2345) and SF-36 physical health component summary score change (pooled mean difference, 1.53 [95% CI, 0.29 to 2.77]; 13 trials; n = 2031). Use of mandibular advancement devices was also associated with a significantly larger ESS score change compared with controls (pooled mean difference, -1.67 [95% CI, 2.09 to -1.25]; 10 trials; n = 1540). Reporting of other health outcomes was sparse; no included trial found significant benefit associated with treatment on mortality, cardiovascular events, or motor vehicle crashes. In 3 systematic reviews, positive airway pressure was significantly associated with reduced blood pressure; however, the difference was relatively small (2-3 mm Hg). Conclusions and Relevance: The accuracy and clinical utility of OSA screening tools that could be used in primary care settings were uncertain. Positive airway pressure and mandibular advancement devices reduced ESS score. Trials of positive airway pressure found modest improvement in sleep-related and general health-related QOL but have not established whether treatment reduces mortality or improves most other health outcomes.

Screening for Prediabetes and Type 2 Diabetes in Children and Adolescents: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Of youths diagnosed with type 2 diabetes, many develop microvascular complications by young adulthood. Objective: To review the evidence on benefits and harms of screening children and adolescents for prediabetes and type 2 diabetes to inform the US Preventive Services Task Force (USPSTF). Data Sources: PubMed/MEDLINE, Cochrane Library, and trial registries through May 3, 2021; references; experts; literature surveillance through July 22, 2022. Study Selection: English-language controlled studies evaluating screening or interventions for prediabetes or type 2 diabetes that was screen detected or recently diagnosed. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Main Outcomes and Measures: Mortality, cardiovascular morbidity, diabetes-related morbidity, development of diabetes, quality of life, and harms. Results: This review included 8 publications (856 participants; mean age, 14 years [range, 10-17 years]). Of those, 6 were from the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. No eligible studies directly evaluated the benefits or harms of screening. One randomized clinical trial (RCT) (TODAY; n = 699 adolescents with obesity; mean age, 14 years) comparing metformin, metformin plus rosiglitazone, and metformin plus lifestyle intervention reported that 2 youths with recently diagnosed diabetes developed kidney impairment (0 vs 1 vs 1, respectively; P > .99) and 11 developed diabetic ketoacidosis (5 vs 3 vs 3, respectively; P = .70). One RCT of 75 adolescents (mean age, 13 years) with obesity with prediabetes compared an intensive lifestyle intervention with standard care and reported that no participants in either group developed diabetes, although follow-up was only 6 months. Regarding harms of interventions, 2 RCTs assessing different comparisons enrolled youths with recently diagnosed diabetes. Major hypoglycemic events were reported by less than 1% of participants. Minor hypoglycemic events were more common among youths treated with metformin plus rosiglitazone than among those treated with metformin or metformin plus lifestyle intervention in TODAY (8.2% vs 4.3% vs 3.4%, P = .05). In 1 study, gastrointestinal adverse events were more commonly reported by those taking metformin than by those taking placebo (abdominal pain: 25% vs 12%; nausea/vomiting: 17% vs 10%; P not reported). Conclusions and Relevance: No eligible studies directly evaluated the benefits or harms of screening for prediabetes and type 2 diabetes in children and adolescents. For youths with prediabetes or recently diagnosed (not screen-detected) diabetes, the only eligible trials reported few health outcomes and found no difference between groups, although evidence was limited by substantial imprecision and a duration of follow-up likely insufficient to assess health outcomes.

Sex differences in gut microbiota modulation of aversive conditioning, open field activity, and basolateral amygdala dendritic spine density.

Gut microbiota influence numerous aspects of host biology, including brain structure and function. Growing evidence implicates gut microbiota in aversive conditioning and anxiety-related behaviors, but research has focused almost exclusively on males. To investigate whether effects of gut dysbiosis on aversive learning and memory differ by sex, adult female and male C57BL/6N mice were orally administered a moderate dose of nonabsorbable antimicrobial medications (ATMs: neomycin, bacitracin, and pimaricin) or a control over 10 days. Changes in gut microbiome composition were analyzed by 16S rRNA sequencing. Open field behavior, cued aversive learning, context recall, and cued recall were assessed. Following behavioral testing, the morphology of basolateral amygdala (BLA) principal neuron dendrites and spines was characterized. Results revealed that ATMs induced gut dysbiosis in both sexes, with stronger effects in females. ATMs also exerted sex-specific effects on behavior and neuroanatomy. Males were more susceptible than females to microbial modulation of locomotor activity and anxiety-like behavior. Females were more susceptible than males to ATM-induced impairments in aversive learning and cued recall. Context recall remained intact, as did dendritic structure of BLA principal neurons. However, ATMs exerted a sex-specific effect on spine density. A second experiment was conducted to isolate the effects of gut perturbation to cued recall. Extinction was also examined. Results revealed no effect of ATMs on cued recall or extinction, suggesting that gut dysbiosis preferentially impacts aversive learning. These data shed new light on how gut microbiota interact with sex to influence aversive conditioning, open field behavior, and BLA dendritic spine architecture.

Screening for Prediabetes and Type 2 Diabetes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Type 2 diabetes is common and is a leading cause of morbidity and disability. Objective: To review the evidence on screening for prediabetes and diabetes to inform the US Preventive Services Task Force (USPSTF). Data Sources: PubMed/MEDLINE, Cochrane Library, and trial registries through September 2019; references; and experts; literature surveillance through May 21, 2021. Study Selection: English-language controlled studies evaluating screening or interventions for prediabetes or diabetes that was screen detected or recently diagnosed. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when at least 3 similar studies were available. Main Outcomes and Measures: Mortality, cardiovascular morbidity, diabetes-related morbidity, development of diabetes, quality of life, and harms. Results: The review included 89 publications (N = 68 882). Two randomized clinical trials (RCTs) (25 120 participants) found no significant difference between screening and control groups for all-cause or cause-specific mortality at 10 years. For harms (eg, anxiety or worry), the trials reported no significant differences between screening and control groups. For recently diagnosed (not screen-detected) diabetes, 5 RCTs (5138 participants) were included. In the UK Prospective Diabetes Study, health outcomes were improved with intensive glucose control with sulfonylureas or insulin. For example, for all-cause mortality the relative risk (RR) was 0.87 (95% CI, 0.79 to 0.96) over 20 years (10-year posttrial assessment). For overweight persons, intensive glucose control with metformin improved health outcomes at the 10-year follow-up (eg, all-cause mortality: RR, 0.64 [95% CI, 0.45 to 0.91]), and benefits were maintained longer term. Lifestyle interventions (most involving >360 minutes) for obese or overweight persons with prediabetes were associated with reductions in the incidence of diabetes (23 RCTs; pooled RR, 0.78 [95% CI, 0.69 to 0.88]). Lifestyle interventions were also associated with improved intermediate outcomes, such as reduced weight, body mass index, systolic blood pressure, and diastolic blood pressure (pooled weighted mean difference, -1.7 mm Hg [95% CI, -2.6 to -0.8] and -1.2 mm Hg [95% CI, -2.0 to -0.4], respectively). Metformin was associated with a significant reduction in diabetes incidence (pooled RR, 0.73 [95% CI, 0.64 to 0.83]) and reduction in weight and body mass index. Conclusions and Relevance: Trials of screening for diabetes found no significant mortality benefit but had insufficient data to assess other health outcomes; evidence on harms of screening was limited. For persons with recently diagnosed (not screen-detected) diabetes, interventions improved health outcomes; for obese or overweight persons with prediabetes, interventions were associated with reduced incidence of diabetes and improvement in other intermediate outcomes.

Reciprocal Relations Between Maternal Depression and Child Behavior Problems in Families Served by Head Start.

This study used longitudinal cross-lagged modeling to examine reciprocal relations between maternal depression and child behavior problems. Data were drawn from 3,119 children (40% Hispanic, 30% African American, 20% White, and 10% other) from the Family and Child Experiences Survey of 2009 (a nationally representative sample of children served by Head Start). Results documented reciprocal relations between maternal depression and child behavior problems across early childhood (i.e., child age 3-5). Furthermore, the effect of child behavior problems on maternal depression was moderated by child race/ethnicity during children's first year in Head Start, such that the negative effect of child behavior problems on African American mothers' depression was more pronounced compared to Hispanics and other racial/ethnic groups.

Early Parenting and the Intergenerational Transmission of Self-Regulation and Behavior Problems in African American Head Start Families.

The present investigation used a national sample of African American Head Start children (N = 640; Mage = 4.40) to determine whether conditions of socioeconomic disadvantage, particularly poverty, low parent education, and single parent homes were associated with children's executive function (EF; attention and impulse control) and behavior problems (internalizing and externalizing symptoms) via the mediating effects of parent-child interactions. Path models with manifest and latent variables revealed that parent-child interactions (i.e., cognitive stimulation, control, and harsh discipline) mediated the association between socioeconomic disadvantage and children's internalizing and externalizing symptoms. Furthermore, parent cognitive stimulation mediated the association between socioeconomic disadvantage and children's EF skills. The overall pattern of results provides empirical support for the family stress model of development in which conditions of socioeconomic disadvantage exert a significant influence on parent-child interactions and in turn children's emergent self-regulation and behavior problems.

Dose-dependent glycometabolic effects of sotagliflozin on type 1 diabetes over 12 weeks: The inTandem4 trial.

AIMS: To assess the dose-related effects of sotagliflozin, a novel dual inhibitor of sodium-glucose co-transporters-1 and -2, in type 1 diabetes (T1D). MATERIALS AND METHODS: In this 12-week, multicentre, randomized, double-blind, placebo-controlled dose-ranging trial, adults with T1D were randomized to once-daily placebo (n = 36) or sotagliflozin 75 mg (n = 35), 200 mg (n = 35) or 400 mg (n = 35). Insulin was maintained at baseline doses. The primary endpoint was least squares mean (LSM) change in glycated haemoglobin (HbA1c) from baseline. Other endpoints included proportion of participants with ≥0.5% HbA1c reduction and assessments of 2-hour postprandial glucose (PPG), weight, and urinary glucose excretion (UGE). RESULTS: From a mean baseline of 8.0% ± 0.8% (full study population), placebo-adjusted LSM HbA1c decreased by 0.3% (P = .07), 0.5% (P < .001) and 0.4% (P = .006) with sotagliflozin 75 mg, 200 mg and 400 mg, respectively, at week 12. In the placebo and sotagliflozin 75 mg, 200 mg and 400 mg groups, 33.3%, 37.1%, 80.0% and 65.7% of participants achieved an HbA1c reduction ≥0.5%. Placebo-adjusted PPG decreased by 22.2 mg/dL (P = .28), 28.7 mg/dL (P = .16) and 50.2 mg/dL (P = .013), UGE increased by 41.8 g/d (P = .006), 57.7 g/d (P < .001) and 70.5 g/d (P < .001), and weight decreased by 1.3 kg (P = .038), 2.4 kg (P < .001) and 2.6 kg (P < .001) with sotagliflozin 75 mg, 200 mg and 400 mg, respectively. One case of severe hypoglycaemia occurred in each sotagliflozin group and one case of diabetic ketoacidosis (DKA) occurred with sotagliflozin 400 mg. CONCLUSIONS: Combined with stable insulin doses, sotagliflozin 200 mg and 400 mg improved glycaemic control and weight in adults with T1D. Sotagliflozin 400 mg reduced PPG levels. UGE increased with all sotagliflozin doses. Rates of severe hypoglycaemia and DKA were low (NCT02459899).

Screening for Cardiovascular Disease Risk With Resting or Exercise Electrocardiography: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Cardiovascular disease (CVD) is the leading cause of death in the United States. Objective: To review the evidence on screening asymptomatic adults for CVD risk using electrocardiography (ECG) to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, and trial registries through May 2017; references; experts; literature surveillance through April 4, 2018. Study Selection: English-language randomized clinical trials (RCTs); prospective cohort studies reporting reclassification, calibration, or discrimination that compared risk assessment using ECG plus traditional risk factors vs traditional risk factors alone. For harms, additional study designs were eligible. Studies of persons with symptoms or a CVD diagnosis were excluded. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Main Outcomes and Measures: Mortality, cardiovascular events, reclassification, calibration, discrimination, and harms. Results: Sixteen studies were included (N = 77 140). Two RCTs (n = 1151) found no significant improvement for screening with exercise ECG (vs no screening) in adults aged 50 to 75 years with diabetes for the primary cardiovascular composite outcomes (hazard ratios, 1.00 [95% CI, 0.59-1.71] and 0.85 [95% CI, 0.39-1.84] for each study). No RCTs evaluated screening with resting ECG. Evidence from 5 cohort studies (n = 9582) showed that adding exercise ECG to traditional risk factors such as age, sex, current smoking, diabetes, total cholesterol level, and high-density lipoprotein cholesterol level produced small improvements in discrimination (absolute improvements in area under the curve [AUC] or C statistics, 0.02-0.03, reported by 3 studies); whether calibration or appropriate risk classification improves is uncertain. Evidence from 9 cohort studies (n = 66 407) showed that adding resting ECG to traditional risk factors produced small improvements in discrimination (absolute improvement in AUC or C statistics, 0.001-0.05) and appropriate risk classification for prediction of multiple cardiovascular outcomes, although evidence was limited by imprecision, quality, considerable heterogeneity, and inconsistent use of risk thresholds used for clinical decision making. Total net reclassification improvements ranged from 3.6% (2.7% event; 0.6% nonevent) to 30% (17% event; 19% nonevent) for studies using the Framingham Risk Score or Pooled Cohort Equations base models. Evidence on potential harms (eg, from subsequent angiography or revascularization) in asymptomatic persons was limited. Conclusions and Relevance: RCTs of screening with exercise ECG found no improvement in health outcomes, despite focusing on higher-risk populations with diabetes. The addition of resting ECG to traditional risk factors accurately reclassified persons, but evidence for this finding had many limitations. The frequency of harms from screening is uncertain.

MATERNAL DEPRESSION AND THE DEVELOPMENT OF EXECUTIVE FUNCTION AND BEHAVIOR PROBLEMS IN HEAD START: INDIRECT EFFECTS THROUGH PARENTING.

The present study used a large, nationally representative sample of Head Start children (N=3,349) from the Family and Child Experiences Survey of 2009 (FACES) to examine associations among maternal depression (measured when children were ˜36 months old) and children's executive function (EF) and behavior problems (measured when children were ˜48 months old). Preliminary analyses revealed that 36% of mothers in the sample had clinically significant levels of depressive symptoms. Furthermore, a path analysis with demographic controls showed a mediation effect that was significant and quite specific; mother-reported warmth (and not mother-child reading) mediated the path between maternal depression, children's EF, and behavior problems. Findings provide empirical support for a family process model in which warm, sensitive parenting supports children's emerging self-regulation and reduces the likelihood of early onset behavior problems in families in which children are exposed to maternal depression.

Vision Screening in Children Aged 6 Months to 5 Years: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Preschool vision screening could allow detection and treatment of vision abnormalities during a critical developmental stage, preserving function and quality of life. Objective: To review the evidence on screening for and treatment of amblyopia, its risk factors, and refractive error in children aged 6 months to 5 years to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, CINAHL, and trial registries through June 2016; references; and experts, with surveillance of the literature through June 7, 2017. Study Selection: English-language randomized clinical trials (RCTs) or prospective cohort studies that evaluated screening, studies evaluating test accuracy, RCTs of treatment vs inactive controls, and cohort studies or case-control studies assessing harms. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Studies were not quantitatively pooled because of clinical and methodological heterogeneity. Main Outcomes and Measures: Visual acuity, amblyopia, school performance, functioning, quality of life, test accuracy, testability, and harms. Results: Forty studies were included (N = 34 709); 34 evaluated test accuracy. No RCTs compared screening with no screening, and no studies evaluated school performance, function, or quality of life. Studies directly assessing earlier or more intensive screening were limited by high attrition. Positive likelihood ratios were between 5 and 10 for amblyopia risk factors or nonamblyogenic refractive error in most studies of test accuracy and were greater than 10 in most studies evaluating combinations of clinical tests. Inability to cooperate may limit use of some tests in children younger than 3 years. Studies with low prevalence (<10%) of vision abnormalities showed high false-positive rates (usually >75%). Among children with amblyopia risk factors (eg, strabismus or anisometropia), patching improved visual acuity of the amblyopic eye by a mean of less than 1 line on a standard chart after 5 to 12 weeks for children pretreated with glasses (2 RCTs, 240 participants); more children treated with patching than with no patching experienced improvement of at least 2 lines (45% vs 21%; P = .003; 1 RCT, 180 participants). Patching plus glasses improved visual acuity by about 1 line after 1 year (0.11 logMAR [95% CI, 0.05-0.17]) for children not pretreated with glasses (1 RCT, 177 participants). Glasses alone improved visual acuity by less than 1 line after 1 year (0.08 logMAR [95% CI, 0.02-0.15], 1 RCT, 177 participants). Conclusions and Relevance: Studies directly evaluating the effectiveness of screening were limited and do not establish whether vision screening in preschool children is better than no screening. Indirect evidence supports the utility of multiple screening tests for identifying preschool children at higher risk for vision problems and the effectiveness of some treatments for improving visual acuity outcomes.

Circulation of prions within dust on a scrapie affected farm.

Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrP(Sc) can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises.

Incubation of ovine scrapie with environmental matrix results in biological and biochemical changes of PrP(Sc) over time.

Ovine scrapie can be transmitted via environmental reservoirs. A pool of ovine scrapie isolates were incubated on soil for one day or thirteen months and eluted prion was used to challenge tg338 mice transgenic for ovine PrP. After one-day incubation on soil, two PrP(Sc) phenotypes were present: G338 or Apl338ii. Thirteen months later some divergent PrP(Sc) phenotypes were seen: a mixture of Apl338ii with either G338 or P338, and a completely novel PrP(Sc) deposition, designated Cag338. The data show that prolonged ageing of scrapie prions within an environmental matrix may result in changes in the dominant PrP(Sc) biological/biochemical properties.

The Toothpick Project: commercialization of a virulence-selected fungal bioherbicide for Striga hermonthica (witchweed) biocontrol in Kenya.

The high-level view of global food systems identifies three all-encompassing barriers to the adoption of food systems solutions: knowledge, policy, and finance. These barriers, and the siloed characteristics of each of these, have hindered the development and adoption of microbial herbicides. How knowledge, policy, and finance are related to the Toothpick Project's path of commercializing a new bioherbicide, early in the scope of the industry, is discussed here. The Toothpick Project's innovation, developed over four decades and commercialized in 2021, uses strains of Fusarium oxysporum f.sp. strigae selected for overproduction and excretion of specific amino acids, killing the parasitic weed Striga hermonthica (Striga or witchweed), Africa's worst pest threat to food security. Historically, bioherbicides have not been a sufficient alternative to the dominant use of synthetic chemical herbicides. To be used safely as bioherbicides, plant pathogens need to be host specific, non-toxic, and yet sufficiently virulent to control a specific weed. For commercialization, bioherbicides must be affordable and require a sufficient shelf life for distribution. Given the current triple storm encountered by the chemical herbicide industry (herbicide-resistant weeds, lawsuits, and consumer pushback), there exists an opportunity to use certain plant pathogens as bioherbicides by enhancing their virulence. By discussing barriers in the scope of knowledge, policy, and finance in the development of the Toothpick Project's new microbial bioherbicide, we hope to help others to anticipate the challenges and provide change-leaders, particularly in policy and finance, a ground level perspective of bioherbicide development. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A microbial bioherbicide for Striga hermonthica control: production, development, and effectiveness of a seed coating agent.

Witchweed (Striga hermonthica), also called striga, is a parasitic weed that causes high yield losses in maize on more than 200 000 ha in Kenya alone. A new commercial, biological herbicide developed in Kenya is able to control striga effectively. The product was approved for use by the Pest Control Products Board in Kenya in September, 2021. It is self-produced in villages using a secondary inoculum provided by a commercial company. The formulated product has some disadvantages, which are a complicated production process, a very short shelf life and high application rate. Additionally, the product has to be applied manually and therefore can only be used in manual production, leaving out the opportunity for farmers using mechanization. For this reason, efforts have been made to formulate the active ingredient Fusarium oxysporum f. sp. strigae strain DSM 33471, as a powder and to use it as a seed coating agent. This article deals with the production of the Fusarium spore powder, its properties, its application to the seed, and its herbicidal effect demonstrated in the first two field trials. The F. oxysporum strain was originally isolated from a wilting striga plant in Kenya. The strain was virulence enhanced to over produce the amino acids leucine, methionine and tyrosine. These amino acids are responsible for a second mode of action apart from the wilting causing effect of the fungus on striga. Whereas leucine and tyrosine have a herbicidal effect, ethylene from methionine triggers the germination of striga seeds in the soil. Additionally, the strain has been improved to be resistant to the fungicide captan, which is commonly used to treat maize seed in Kenya. Seed coating tests conducted on 25 striga-infested small holder farms spread out in six counties of western Kenya reported yield increases of up to 88%. A second trial carried out by the Kenyan Agricultural and Livestock Research Organization showed a 93% reduction of emerged striga plants. © 2023 Society of Chemical Industry.

The oral secretion of infectious scrapie prions occurs in preclinical sheep with a range of PRNP genotypes.

Preclinical sheep with the highly scrapie-susceptible VRQ/VRQ PRNP genotype secrete prions from the oral cavity. In order to further understand the significance of orally available prions, buccal swabs were taken from sheep with a range of PRNP genotypes and analyzed by serial protein misfolding cyclic amplification (sPMCA). Prions were detected in buccal swabs from scrapie-exposed sheep of genotypes linked to high (VRQ/VRQ and ARQ/VRQ) and low (ARR/VRQ and AHQ/VRQ) lymphoreticular system involvement in scrapie pathogenesis. For both groups, the level of prion detection was significantly higher than that for scrapie-resistant ARR/ARR sheep which were kept in the same farm environment and acted as sentinel controls for prions derived from the environment which might contaminate the oral cavity. In addition, sheep with no exposure to the scrapie agent did not contain any measurable prions within the oral cavity. Furthermore, prions were detected in sheep over a wide age range representing various stages of preclinical disease. These data demonstrate that orally available scrapie prions may be a common feature in sheep incubating scrapie, regardless of the PRNP genotype and any associated high-level accumulation of PrP(Sc) within lymphoreticular tissues. PrP(Sc) was present in buccal swabs from a large proportion of sheep with PRNP genotypes associated with relatively low disease penetrance, indicating that subclinical scrapie infection is likely to be a common occurrence. The significance of positive sPMCA reactions was confirmed by the transmission of infectivity in buccal swab extracts to Tg338 mice, illustrating the likely importance of orally available prions in the horizontal transmission of scrapie.

Head Impact Location, Speed and Angle from Falls and Trips in the Workplace.

Traumatic brain injury (TBI) is a common injury in the workplace. Trips and falls are the leading causes of TBI in the workplace. However, industrial safety helmets are not designed for protecting the head under these impact conditions. Instead, they are designed to pass the regulatory standards which test head protection against falling heavy and sharp objects. This is likely to be due to the limited understanding of head impact conditions from trips and falls in workplace. In this study, we used validated human multi-body models to predict the head impact location, speed and angle (measured from the ground) during trips, forward falls and backward falls. We studied the effects of worker size, initial posture, walking speed, width and height of the tripping barrier, bracing and falling height on the head impact conditions. Overall, we performed 1692 simulations. The head impact speed was over two folds larger in falls than trips, with backward falls producing highest impact speeds. However, the trips produced impacts with smaller impact angles to the ground. Increasing the walking speed increased the head impact speed but bracing reduced it. We found that 41% of backward falls and 19% of trips/forward falls produced head impacts located outside the region of helmet coverage. Next, we grouped all the data into three sub-groups based on the head impact angle: [0°, 30°], (30°, 60°] and (60°, 90°] and excluded groups with small number of cases. We found that most trips and forward falls lead to impact angles within the (30°, 60°] and (60°, 90°] groups while all backward falls produced impact angles within (60°, 90°] group. We therefore determined five representative head impact conditions from these groups by selecting the 75th percentile speed, mean value of angle intervals and median impact location (determined by elevation and azimuth angles) of each group. This led to two representative head impact conditions for trips: 2.7 m/s at 45° and 3.9 m/s at 75°, two for forward falls: 3.8 m/s at 45° and 5.5 m/s at 75° and one for backward falls: 9.4 m/s at 75°. These impact conditions can be used to improve industrial helmet standards.

In-Depth Bicycle Collision Reconstruction: From a Crash Helmet to Brain Injury Evaluation.

Traumatic brain injury (TBI) is a prevalent injury among cyclists experiencing head collisions. In legal cases, reliable brain injury evaluation can be difficult and controversial as mild injuries cannot be diagnosed with conventional brain imaging methods. In such cases, accident reconstruction may be used to predict the risk of TBI. However, lack of collision details can render accident reconstruction nearly impossible. Here, we introduce a reconstruction method to evaluate the brain injury in a bicycle-vehicle collision using the crash helmet alone. Following a thorough inspection of the cyclist's helmet, we identified a severe impact, a moderate impact and several scrapes, which helped us to determine the impact conditions. We used our helmet test rig and intact helmets identical to the cyclist's helmet to replicate the damage seen on the cyclist's helmet involved in the real-world collision. We performed both linear and oblique impacts, measured the translational and rotational kinematics of the head and predicted the strain and the strain rate across the brain using a computational head model. Our results proved the hypothesis that the cyclist sustained a severe impact followed by a moderate impact on the road surface. The estimated head accelerations and velocity (167 g, 40.7 rad/s and 13.2 krad/s2) and the brain strain and strain rate (0.541 and 415/s) confirmed that the severe impact was large enough to produce mild to moderate TBI. The method introduced in this study can guide future accident reconstructions, allowing for the evaluation of TBI using the crash helmet only.

A Review of Cyclist Head Injury, Impact Characteristics and the Implications for Helmet Assessment Methods.

Head injuries are common for cyclists involved in collisions. Such collision scenarios result in a range of injuries, with different head impact speeds, angles, locations, or surfaces. A clear understanding of these collision characteristics is vital to design high fidelity test methods for evaluating the performance of helmets. We review literature detailing real-world cyclist collision scenarios and report on these key characteristics. Our review shows that helmeted cyclists have a considerable reduction in skull fracture and focal brain pathologies compared to non-helmeted cyclists, as well as a reduction in all brain pathologies. The considerable reduction in focal head pathologies is likely to be due to helmet standards mandating thresholds of linear acceleration. The less considerable reduction in diffuse brain injuries is likely to be due to the lack of monitoring head rotation in test methods. We performed a novel meta-analysis of the location of 1809 head impacts from ten studies. Most studies showed that the side and front regions are frequently impacted, with one large, contemporary study highlighting a high proportion of occipital impacts. Helmets frequently had impact locations low down near the rim line. The face is not well protected by most conventional bicycle helmets. Several papers determine head impact speed and angle from in-depth reconstructions and computer simulations. They report head impact speeds from 5 to 16 m/s, with a concentration around 5 to 8 m/s and higher speeds when there was another vehicle involved in the collision. Reported angles range from 10° to 80° to the normal, and are concentrated around 30°-50°. Our review also shows that in nearly 80% of the cases, the head impact is reported to be against a flat surface. This review highlights current gaps in data, and calls for more research and data to better inform improvements in testing methods of standards and rating schemes and raise helmet safety.