Effects of rumen-protected methionine supplementation on the performance of high production dairy cows in the tropics.

Increasing methionine availability in dairy cow diets during the first third of lactation may enhance their performance and health. The aim of this study was to determine the effect of supplementing rumen-protected methionine (Smartamine® M, SM) in a lactation diet with protein and energy levels calculated according to the literature. Seventy-six multiparous Holstein cows (39.1 ± 6.8 kg of milk/d and 65 ± 28 DIM) were assigned to 1 of 2 dietary treatments (38/treatment) according to a randomized complete block design with a 2-wk (covariate) and 10-wk experimental period. Treatments were a basal diet (CON; 3.77 Lys:1Met); and CON + 23 g SM (2.97 Lys:1 Met). Individual milk samples were taken every 2 weeks to determine milk composition. Blood was collected from 24 cows on d+30 d to measure plasma AA levels. Body weight and body condition score (BCS) were measured at the beginning and the end of the experiment. The SM diet promoted higher milk yield (41.7 vs. 40.1 kg/d; P = 0.03). Energy-corrected milk yield (41.0 vs. 38.0 kg/d), milk protein yield (1.30 vs. 1.18 kg/d), milk protein (3.14% vs. 2.97%) and casein (2.39% vs. 2.28%) were also different (P < 0.01) as well as milk fat yield (1.42 vs. 1.29 kg/d; P = 0.02). A trend (P = 0.06) for higher milk fat % (3.41% vs. 3.21%) was observed. Both diets resulted in similar body weight, but CON-fed cows tended (P = 0.08) to have higher BCS. Higher plasma methionine levels were determined with SM compared with CON (29.6 vs. 18.4 µM; P < 0.01), but lysine and histidine were not different. Dietary supplementation of RPM improved productive performance by increasing milk yield and milk components yields, suggesting better dietary AA utilization when Met levels are adjusted in Lys-adequate lactation diets.

Multiplex Single-Molecule Kinetics of Nanopore-Coupled Polymerases.

DNA polymerases have revolutionized the biotechnology field due to their ability to precisely replicate stored genetic information. Screening variants of these enzymes for specific properties gives the opportunity to identify polymerases with different features. We have previously developed a single-molecule DNA sequencing platform by coupling a DNA polymerase to an α-hemolysin pore on a nanopore array. Here, we use this approach to demonstrate a single-molecule method that enables rapid screening of polymerase variants in a multiplex manner. In this approach, barcoded DNA strands are complexed with polymerase variants and serve as templates for nanopore sequencing. Nanopore sequencing of the barcoded DNA reveals both the barcode identity and kinetic properties of the polymerase variant associated with the cognate barcode, allowing for multiplexed investigation of many polymerase variants in parallel on a single nanopore array. Further, we develop a robust classification algorithm that discriminates kinetic characteristics of the different polymerase mutants. As a proof of concept, we demonstrate the utility of our approach by screening a library of ∼100 polymerases to identify variants for potential applications of biotechnological interest. We anticipate our screening method to be broadly useful for applications that require polymerases with altered physical properties.

Barriers and Motivators for Tractor ROPS Retrofitting in Iowa.

Iowa State University Extension and Outreach conducted an assessment of Iowa farm operators' perceptions of the barriers and motivators when considering retrofitting tractors with rollover protective structures (ROPS). A statewide sample of approximately 2,000 farm operators was surveyed in the 2017 Iowa Farm and Rural Life Poll. A series of questions was asked to evaluate the importance of potential barriers to decisions to not retrofit a tractor and potential motivators that could influence the decision to retrofit or purchase a tractor with ROPS. The survey received a 48% response rate (999 responses). Among the 76% of Iowa farm operators who reported at least one pre-1985 tractor, only 18.6% reported that all of those tractors had ROPS. The remaining 81.4% had at least one tractor that did not have ROPS. Iowa farm operators' perceptions of the barriers and motivators when considering retrofitting tractors with ROPS are shared. The results of Iowa farm operators' perceptions will be used as Iowa State University Extension and Outreach prepares to align efforts with the National Tractor Safety Coalition and participate in the National ROPS Rebate Program, with the goal of reducing tractor fatalities.

American firearm homicides: The impact of your neighbors.

BACKGROUND: Restrictive firearm legislation has correlated with decreased overall firearm fatality rates, but not with firearm-related homicide or firearm mortality among Black Americans. We hypothesized that firearm trafficking from states with less restrictive firearm legislation to neighboring states with more restrictive firearm legislation increases firearm homicide rates in those restrictive states. METHODS: For years 2011-2015, state firearm legislation Brady Campaign to Prevent Gun Violence scorecards were analyzed in relation to firearms traced by the Bureau of Alcohol, Tobacco, and Firearms and Center for Disease Control and Prevention firearm mortality rates. States were ranked by Brady score and arranged by quintile to establish the Standardized Brady Score. The effect of less-restrictive neighboring states on the 10 most-restrictive firearm legislation states was modeled by averaging the 10 most-restrictive states with their bordering states to create a Border Adjustment Score. Firearm fatality rates were calculated for each quintile and Poisson regression models were created for each score and outcome. Model fit was compared using Akaike Information Criterion (AIC). RESULTS: There were 169,396 firearm fatalities including 57,885 firearm homicides. Comparing top and bottom quintile firearm legislation states, 65% vs. 44% of firearms traced by the Bureau of Alcohol, Tobacco, Firearms and Explosives originated in other states respectively. The Border Adjustment Score generated a more linear relationship than the Standardized Brady Score for all firearm fatality categories as firearm legislation scores decreased. The Border Adjustment Score minimized the AIC with respect to the Standardized Brady Score for black (AIC, 4443 vs. 4680) and white firearm homicide rates (3243 vs. 4319), indicating improved model fit after adjustment for neighboring state firearm legislation. CONCLUSION: Our results suggest that firearm movement across states plays an important role in firearm homicides. Accounting for firearm legislation in both individual and neighboring states may improve our understanding of the relationship between firearm legislation and homicide. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level IV.

Extraction Force Prediction for Male Entrapment Victims with Different Body Types Submerged below the Grain Surface.

One contributor to agriculture's high death rate is confined space fatalities caused by entrapment in grain. Over 1,000 grain-related fatalities have been documented by researchers in 43 states, and states with the largest grain storage capacities have been shown to experience a proportionally larger number of suffocation fatalities. Several researchers have measured extraction forces in specific conditions, but a reference standard is needed for estimating the extraction forces for grain suffocation victims in common conditions. A prediction model for estimating extraction forces was developed using the principle of boundary shear, an approximation of human surface area, and a commonly accepted equation for lateral granular pressure. This research reintroduces the prediction model for extraction forces and explores several sensitivity analyses of the input variables. It also updates the anthropometric data used in the model calculations and produces extraction force estimates for adult male victims with different body shapes submerged below the grain surface. Results from the prediction model are presented graphically for common input variables, various entrapment depths, and adult male body shapes.

Editorial: ROPS Are Not Homemade.

Safety professionals should speak up when secondary school teachers and FFA advisors consider fabricating and installing low-cost rollover protective structures (ROPS) as service learning projects for ag education students or as a service to the farm community. These projects are often motivated by the desire to address the continued occurrence of tractor rollovers, which are the most frequent cause of farm-related fatalities (NIOSH, 2018). These projects have also been made feasible by the availability of online plans for ROPS fabrication, including plans from the National Institute for Occupational Safety and Health (NIOSH) that are designed for specific makes and models of tractors. Because of the large number of older tractors that were not originally equipped with ROPS, and the cost and lack of easily accessible ROPS retrofits, fabricating a structure to provide operator protection in the event of an overturn can be attractive as a service learning project. In addition, several of the NIOSH Agricultural Injury Prevention Centers have promoted these projects as a means of reducing the frequency of rollover-related injuries. However, in light of the liability risk involved, such projects should be weighed carefully. Fabricating a ROPS is not the same as building a chicken house, fabricating a welding table, or welding together a hay feeder. ROPS are life-saving devices that must meet specific design and installation standards that exceed the expertise available in most secondary school ag education shops, and even most local machine shops. In fact, "ROPS" is a technical term defined by OSHA standards and the Society of Automotive Engineers (SAE). It does not apply-nor should it be applied-to untested, homemade structures that are installed on tractors with the intent of protecting the operator.

Estimating Passive Stress Acting on a Grain Entrapment Victim's Chest.

Grain entrapments remain a major concern in the grain industry, with 1,100 incidents documented since the 1970s. One particular concern is the ability of a victim to breathe while entrapped in grain. Anecdotal reports suggest that victims struggle to breathe when entrapped in grain to a depth that covers their chests, yet some evidence indicates that victims should be able to breathe normally as long as their airways are not blocked regardless of depth. The hypothesis for this discrepancy is that previously published experiments measured an active stress state in the grain, while a person breathing also experiences a passive stress state during inhalation. The passive stress is significantly larger than the active stress. The objective of this study was to measure the passive stress when pushing against grain, such as during inhalation, and compare it to active stress state measurements. An MTS Criterion testing machine, which is a force deformation testing device, was used to push a block horizontally against a column of grain and record the force and displacement during the movement. The measured passive stress was calculated from the force and displacement values and ranged from 9.4 to 11.0 kPa at a depth of 20 to 30 cm. These values are three to four times larger than previously published measurements of stresses at similar depths. This result indicates that the discrepancy between experimental results and anecdotal reports is most likely due to the type of stress state experienced in grain entrapment. Findings imply that the pressures on the victim's chest during entrapment are sufficient to cause breathing difficulties or crush/positional asphyxiation in some cases. A full-scale study is recommended.

A 100-Year Review: Protein and amino acid nutrition in dairy cows.

Considerable progress has been made in understanding the protein and amino acid (AA) nutrition of dairy cows. The chemistry of feed crude protein (CP) appears to be well understood, as is the mechanism of ruminal protein degradation by rumen bacteria and protozoa. It has been shown that ammonia released from AA degradation in the rumen is used for bacterial protein formation and that urea can be a useful N supplement when lower protein diets are fed. It is now well documented that adequate rumen ammonia levels must be maintained for maximal synthesis of microbial protein and that a deficiency of rumen-degradable protein can decrease microbial protein synthesis, fiber digestibility, and feed intake. Rumen-synthesized microbial protein accounts for most of the CP flowing to the small intestine and is considered a high-quality protein for dairy cows because of apparent high digestibility and good AA composition. Much attention has been given to evaluating different methods to quantify ruminal protein degradation and escape and for measuring ruminal outflows of microbial protein and rumen-undegraded feed protein. The methods and accompanying results are used to determine the nutritional value of protein supplements and to develop nutritional models and evaluate their predictive ability. Lysine, methionine, and histidine have been identified most often as the most-limiting amino acids, with rumen-protected forms of lysine and methionine available for ration supplementation. Guidelines for protein feeding have evolved from simple feeding standards for dietary CP to more complex nutrition models that are designed to predict supplies and requirements for rumen ammonia and peptides and intestinally absorbable AA. The industry awaits more robust and mechanistic models for predicting supplies and requirements of rumen-available N and absorbed AA. Such models will be useful in allowing for feeding lower protein diets and increased efficiency of microbial protein synthesis.

Apparent Coefficient of Friction of Wheat on Denim.

Calculation of the extraction force for a grain entrapment victim requires a coefficient of friction between the grain and the surface of the victim. Because denim is a common fabric for the work clothes that cover entrapment victims, the coefficient of friction between grain and denim becomes necessary. The purpose of this research was to calculate the apparent coefficient of friction of wheat on denim fabric using a proven procedure. The expectation is to improve the current understanding of conditions that influence extraction forces for victims buried in wheat. The apparent coefficient of friction of wheat on denim fabric was calculated to be 0.167 with a standard deviation of ±0.013. The wheat had a moisture content of 10.7% (w.b.) and bulk density of 778.5 kg m-3. The apparent coefficient of friction of wheat on denim was not significantly affected by pull speeds of 0.004, 0.008, and 0.021 mm s-1 nor normal grain pressures of 3.2, 4.8, 6.3, 7.9, and 11.1 kPa. This is a beginning of understanding the conditions that influence the extraction forces for grain entrapment victims.

Agricultural Worker Injury Comparative Risk Assessment Methodology: Assessing Corn and Biofuel Switchgrass Production Systems.

Keeping workers safe is a continuing challenge in agricultural production. Risk assessment methodologies have been used widely in other industries to better understand systems and enhance decision making, yet their use in production agriculture has been limited. This article describes the considerations and the approach taken to measure the difference in worker injury risks between two agricultural production systems. A model was developed specifically for the comparison of worker injury risk between corn and biofuel switchgrass production systems. The model is composed of injury and exposure values that were used in a Monte Carlo simulation. The output of this risk assessment shows that approximately 99% of the values from the Monte Carlo simulation rank corn production as a greater worker injury risk than biofuel switchgrass production. Furthermore, the greatest contributing factors for each production system were identified as harvest, and that finding aligns with current literature.

Likelihood of Entanglement when Materials are Dropped Vertically onto a Rotating PTO Knuckle.

Power take-off (PTO) is a common method of transferring power from a tractor to a towed piece of machinery. The PTO is also a well-documented cause of severe and often permanent disabling injuries to farm operators. The physical conditions that cause entanglements are not well established. Several studies have explored the parameters of PTO entanglements as materials have been drawn across a rotating PTO knuckle to test for entanglement probability. The objective of this study was to determine probability of entanglement when materials are dropped vertically onto a PTO knuckle spinning at 540 rpm. A total of 360 randomized trials were conducted with ten replications for each of the six positions (center of yoke, edge of yoke rotating downward, edge of yoke rotating upward, center of cross, edge of cross rotating downward, and edge of cross rotating upward) and six different materials (woven cotton athletic shoe lace, cotton workboot lace, leather workboot lace, cotton twine, denim strip, and Tyvek strip). Not a single entanglement was recorded. Dramatic high-speed video imagery authenticated the material's motion and path as it interacted with the rotating PTO knuckle.

Contributing Causes of Injury or Death in Grain Entrapment, Engulfment, and Extrication.

OBJECTIVES: Grain entrapments and engulfments are one of most common hazards associated with grain storage facilities, with over 1,140 such entrapments/engulfments documented since the 1970s. The objective of the study was to determine the factors that contribute to injury or death in grain entrapment, engulfment, and extrication cases. METHODS: A literature review, including data contained in the Purdue Agricultural Confined Spaces Incident Database (PACSID), was conducted to determine the conditions that the body experiences during an entrapment or engulfment in grains and during extrication efforts. RESULTS: Based on the review, the conditions a human body faces during an entrapment, engulfment, or extraction can be split into two broad categories-environmental and physiological/psychological. The environmental factors depend on the grain's properties, depth of entrapment or engulfment, position of the victim's body, and characteristics of the storage unit, which include the grain's lateral pressure, vertical pressure, and weight, as well as friction, oxygen availability and diffusion rate, and grain temperature. The physiological and psychological factors are related to the individual's age and physical and psychological conditions, and manifest themselves in terms of oxygen consumption, asphyxiation (including aspiration, lack of oxygen, compression or splinting of the thorax), blood flow, and heart rate. CONCLUSION: Of all the above factors, a review of fatality data contained in the PACSID indicate that aspiration, asphyxiation, grain weight, and lateral pressure are most likely the primary cause of death for most entrapment victims. Research gaps found by this study include an understanding of the impact of lateral pressure on lung expansion and oxygen availability and consumption rate, and the need for more case studies to accurately determine cause of death.

Safety and health in biomass production, transportation, and storage: a commentary based on the biomass and biofuels session at the 2013 North American Agricultural Safety Summit.

There is significant interest in biomass production ranging from government agencies to the private sector, both inside and outside of the traditional production agricultural setting. This interest has led to an increase in the development and production of biomass crops. Much of this effort has focused on specific segments of the process, and more specifically on the mechanics of these individual segments. From a review of scientific literature, it is seen that little effort has been put into identifying, classifying and preventing safety hazards in on-farm biomass production systems. This commentary describes the current status of the knowledge pertaining to health and safety factors of biomass production and storage in the US and identifies areas of standards development that the biomass industry needs from the agricultural safety and health community.

Complications following thoracic trauma managed with tube thoracostomy.

INTRODUCTION: Tube thoracostomy is a common procedure used to treat traumatic chest injuries. Although the mechanism of injury traditionally does not alter chest tube management, complication rates may vary depending on the severity of injury. The purpose of this study was to investigate the incidence of and risk factors associated with chest tube complications (CTCs) following thoracic trauma. METHODS: A retrospective chart review of all trauma patients (≥16 years old) admitted to an urban level 1 trauma centre (1/2007-12/2007) was conducted. Patients who required chest tube (CT) therapy for thoracic injuries within 24 h of admission and survived until CT removal were included. CTCs were defined as a recurrent pneumothorax or residual haemothorax requiring CT reinsertion within 24 h after initial tube removal or addition of new CT >24 h after initial placement. Variables including demographic data, mechanism, associated injuries, initial vital signs, chest abbreviated injury score (AIS), injury severity score (ISS), Glasgow coma score (GCS) and length of stay (LOS) and CT-specific variables (e.g. indication, timing of insertion, and duration of therapy) were compared using the chi square test, Mann-Whitney test, and multivariate analysis. RESULTS: 154 patients were included with 22.1% (n=34) developing a CTC. On univariate analysis, CTCs were associated with longer ICU and hospital LOS (p=0.02 and p<0.001), increased chest AIS (p=0.01), and the presence of an extrathoracic injury (p=0.047). Results of the multivariate analysis indicated that only increased chest AIS (OR 2.49; p=0.03) was a significantly independent predictor of CTCs. CONCLUSIONS: CTCs following chest trauma are common and are associated with increased morbidity. The severity of the thoracic injury, as measured by chest AIS, should be incorporated into the development of CT management guidelines in order to decrease the incidence of CTCs.

Lower extremity joint moments during carrying tasks in children.

Farm youth often carry loads that are proportionally large and/or heavy, and field measurements have determined that these tasks are equivalent to industrial jobs with high injury risks. The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity joint moments during carrying tasks. Three age groups (8-10 years, 12-14 years, adults), three load amounts (0%, 10%, 20% BW), and three load symmetry levels (unilateral large bucket, unilateral small bucket, bilateral small buckets) were tested. Inverse dynamics was used to determine maximum ankle, knee, and hip joint moments. Ankle dorsiflexion, ankle inversion, ankle eversion, knee adduction, and hip extension moments were significantly higher in 8-10 and 12-14 year olds. Ankle plantar flexion, ankle inversion, knee extension, and hip extension moments were significantly increased at 10% and 20% BW loads. Knee and hip adduction moments were significantly increased at 10% and 20% BW loads when carrying a unilateral large bucket. Of particular concern are increased ankle inversion and eversion moments for children, along with increased knee and hip adduction moments for heavy, asymmetrical carrying tasks. Carrying loads bilaterally instead of unilaterally avoided increases in knee and hip adduction moments with increased load amount.

Short simulation training improves objective skills in established advanced practitioners managing emergencies on the ward and surgical intensive care unit.

BACKGROUND: Several studies evaluating simulation training in intensive care unit (ICU) physicians have demonstrated improvement in leadership and management skills. No study to date has evaluated whether such training is useful in established ICU advanced practitioners (APs). We hypothesized that human patient simulator-based training would improve surgical ICU APs' skills at managing medical crises. METHODS: After institutional review board approval, 12 APs completed ½ day of simulation training on the SimMan, Laerdal system. Each subject participated in five scenarios, first as team leader (pretraining scenario), then as observer for three scenarios, and finally, again as team leader (posttraining). Faculty teaching accompanied each scenario and preceded a debriefing session with video replay. Three experts scored emergency care skills (Airway-Breathing-Circulation [ABCs] sequence, recognition of shock, pneumothorax, etc.) and teamwork leadership/interpersonal skills. A multiple choice question examination and training effectiveness questionnaire were completed before and after training. Fellows underwent the same curriculum and served to validate the study. Pre- and postscores were compared using the Wilcoxon signed rank test with two-tailed significance of 0.05. RESULTS: Improvement was seen in participants' scores combining all parameters (73% ± 13% vs. 80% ± 11%, p = 0.018). AP leadership/interpersonal skills (+12%), multiple choice question examination (+4%), and training effectiveness questionnaire (+6%) scores improved significantly (p < 0.05). Fellows teamwork leadership/interpersonal skills scores were higher than APs (p < 0.001) but training brought AP scores to fellow levels. Interrater reliability was high (r = 0.77, 95% confidence interval 0.71-0.82; p < 0.001). CONCLUSIONS: Human patient simulator training in established surgical ICU APs improves leadership, teamwork, and self-confidence skills in managing medical emergencies. Such a validated curriculum may be useful as an AP continuing education resource.

Does the trauma system protect against the weekend effect?

BACKGROUND: Occurrence on weekends or at night has been associated with poor outcomes for time-sensitive conditions including ST elevation myocardial infarction, stroke, and cardiac arrest. We sought to determine whether the "weekend effect" exists for injured patients at our trauma center. METHODS: We performed a retrospective cohort study at a Level I trauma center (2006-2008). The relative risks of mortality associated with weekend or night arrival were estimated using unadjusted and adjusted analyses. RESULTS: Four thousand three hundred eighty-two patients were included. One-third of patients (34.0%) arrived on weekends, and 23.3% of patients arrived at night (12:00 midnight to 6:00 am). Average age was 43.2 years (44.2 weekdays vs. 41.4 weekends, p < 0.001 and 45.1 days vs. 37.5 nights, p < 0.001), 72.3% were men (72.6 weekdays vs. 71.8 weekends, p = not significant (NS) and 71.0% days vs. 76.8% nights, p < 0.001), overall Injury Severity Score was 13.7 (13.7 weekdays vs. 13.6 weekends, p = NS and 13.7 days vs. 13.3 nights, p = NS), and overall Glasgow Coma Scale score was 13.6 (13.5 weekdays vs. 13.6 weekends, p = NS and 13.7 days vs. 13.4 nights, p < 0.05). In unadjusted analyses, no survival difference was detected for patients presenting on weekends (5.2% vs. 5.3%; odds ratio [OR], 0.98; and 95% confidence interval [CI], 0.75-1.28) or at night (4.4% vs. 5.5%; OR, 0.81; and 95% CI, 0.58-1.11). In adjusted analyses controlling for age, sex, Injury Severity Score, Glasgow Coma Scale score, and arrival hypotension, no survival difference was detected on weekends (OR, 1.03 and 95% CI, 0.71-1.51) or at night (OR, 0.79 and 95% CI, 0.49-1.25). CONCLUSION: Differential mortality on off-hours is not seen at our Level I trauma center. Outcomes that are independent of time of day and day of week may be because of the explicit requirements for trauma centers to be fully staffed and operational at all times. There are implications for staffing and systems solutions for other time-sensitive disease including ST elevation myocardial infarction, stroke, and cardiac arrest. Interventions may include the development of a categorization system based on emergency care capabilities, development of explicit staffing requirements, and requiring an emergency care-specific quality improvement program.

The effects of age and type of carrying task on lower extremity kinematics.

The purpose of this study was to determine the effects of age, load amount and load symmetry on lower extremity kinematics during carrying tasks. Forty-two participants in four age groups (8-10 years, 12-14 years, 15-17 years and adults) carried loads of 0%, 10% and 20% body weight (BW) in large or small buckets unilaterally and bilaterally. Reflective markers were tracked to determine total joint range of motion and maximum joint angles during the stance phase of walking. Maximum hip extension, hip adduction and hip internal rotation angles were significantly greater for each of the child/adolescent age groups as compared with adults. In addition, maximum hip internal rotation angles significantly increased when carrying a 20% BW load. The observation that the 8-10-year-old age group carried the lightest absolute loads and still displayed the highest maximum hip internal rotation angles suggests a particular necessity in setting carrying guidelines for the youngest children. STATEMENT OF RELEVANCE: Bucket-carrying tasks were analysed as a function of age group, load amount and load symmetry. Hip joint rotations significantly increased when carrying 20% BW loads and in children as compared to adults, which suggests a particular necessity in setting carrying guidelines for the youngest age group (8-10 year olds).

Misplaced inferior vena caval filter in right renal vein with erosion into renal collecting system.

Misplacement of an inferior vena caval (IVC) filter is an infrequent event. We describe a patient who underwent IVC filter placement after lower extremity trauma. Fourteen years later, the presence of microscopic hematuria prompted evaluation. Computed tomography urography revealed an IVC filter within the right renal vein. Ureteroscopy revealed penetration of a filter tine into the collecting system. The patient is being followed conservatively.