Steve Ingham - Academia.edu (original) (raw)

Papers by Steve Ingham

Research paper thumbnail of Thermal tolerance of O157 and non-O157 Shiga toxigenic strains of Escherichia coli, Salmonella, and potential pathogen surrogates, in frankfurter batter and ground beef of varying fat levels

Journal of food protection, 2014

The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with ill... more The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. We compared the thermal tolerance (D55°C) of three or more strains of each of these six non-O157 STEC serogroups with five strains of O157:H7 STEC in 7% fat ground beef. D55°C was also determined for at least one heat-tolerant STEC strain per serogroup in 15 and 27% fat ground beef. D55°C of single-pathogen cocktails of O157 and non-O157 STEC, Salmonella, and potential pathogen surrogates, Pediococcus acidilactici and Staphylococcus carnosus, was determined in 7, 15, and 27% fat ground beef and in frankfurter batter. Samples (25 g) were heated for up to 120 min at 55°C, survivors were enumerated, and log CFU per gram was plotted versus time. There were significant differences in D55°C across all STEC strains heated in 7% fat ground beef (P < 0.05), but no non-O157 STEC strain had D55°C greater than the range observed for O157 STEC. D55°C ...

Research paper thumbnail of Sodium bicarbonate improves swimming performance

International journal of sports medicine, 2008

Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity... more Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity events, probably due to an increase in buffering capacity, but its influence on single-bout swimming performance has not been investigated. The effects of sodium bicarbonate supplementation on 200 m freestyle swimming performance were investigated in elite male competitors. Following a randomised, double blind counterbalanced design, 9 swimmers completed maximal effort swims on 3 separate occasions: a control trial (C); after ingestion of sodium bicarbonate (SB: NaHCO3 300 mg . kg (-1) body mass); and after ingestion of a placebo (P: CaCO3 200 mg . kg (-1) body mass). The SB and P agents were packed in gelatine capsules and ingested 90 - 60 min prior to each 200 m swim. Mean 200 m performance times were significantly faster for SB than C or P (1 : 52.2 +/- 4.7; 1 : 53.7 +/- 3.8; 1 : 54.0 +/- 3.6 min : ss; p < 0.05). Base excess, pH and blood bicarbonate were all elevated pre-exercise...

Research paper thumbnail of Growth of Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus on cheese during extended storage at 25°C

Journal of food protection, 2014

Potentially hazardous foods require time/temperature control for safety. According to the U.S. Fo... more Potentially hazardous foods require time/temperature control for safety. According to the U.S. Food and Drug Administration Food Code, most cheeses are potentially hazardous foods based on pH and water activity, and a product assessment is required to evaluate safety of storage >6 h at 21°C. We tested the ability of 67 market cheeses to support growth of Listeria monocytogenes (LM), Salmonella spp. (SALM), Escherichia coli O157:H7 (EC), and Staphylococcus aureus (SA) over 15 days at 25°C. Hard (Asiago and Cheddar), semi-hard (Colby and Havarti), and soft cheeses (mozzarella and Mexican-style), and reduced-sodium or reduced-fat types were tested. Single-pathogen cocktails were prepared and individually inoculated onto cheese slices (∼10(5) CFU/g). Cocktails were 10 strains of L. monocytogenes, 6 of Salmonella spp., or 5 of E. coli O157:H7 or S. aureus. Inoculated slices were vacuum packaged and stored at 25°C for ≤ 15 days, with surviving inocula enumerated every 3 days. Percent s...

Research paper thumbnail of Evaluation of Small-Scale Hot-Water Post-Packaging Pasteurization Treatments for Destruction of Listeria monocytogenes on Ready-To-Eat Beef Snack Sticks and Natural Casing Wieners

This study was conducted to evaluate small-scale hot-water postpackaging pasteurization (PPP) as ... more This study was conducted to evaluate small-scale hot-water postpackaging pasteurization (PPP) as a postlethality (post- cooking) treatment for Listeria monocytogenes on ready-to-eat beef snack sticks and natural-casing wieners. Using a com- mercially available plastic packaging film specifically designed for PPP applications and 2.8 liters of boiling water (1008C) in a sauce pan on a hot plate, an average reduction in

Research paper thumbnail of Altitude Training for Elite Endurance Performance

Current Sports Medicine Reports, 2012

Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of... more Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of performance on return to sea level. The purpose of the current review article was to update and evaluate recent literature relevant to the practical application of altitude training for endurance athletes. Consequently, the literature can be considered in either of two categories: performance-led investigations or mechanistic advancements/insights. Each section discusses the relevant literature and proposes future directions where appropriate.

Research paper thumbnail of Physiological and Performance Effects of Low- versus Mixed-Intensity Rowing Training

Medicine & Science in Sports & Exercise, 2008

To examine the impact of low-intensity and a mixture of low- and high-intensity training on physi... more To examine the impact of low-intensity and a mixture of low- and high-intensity training on physiological and performance responses in rowing. Eighteen experienced rowers undertook a 12-wk program of 100% &amp;amp;amp;amp;amp;amp;amp;amp;lt; or = lactate threshold (LT) training (LOW) or 70% training at &amp;amp;amp;amp;amp;amp;amp;amp;lt; or = LT and 30% at halfway (50%Delta) between the V O2 at LT and V O2peak (MIX). Responses were assessed before and after training by a progressive exercise test to exhaustion; multiple &amp;amp;amp;amp;amp;amp;amp;amp;quot;square-wave&amp;amp;amp;amp;amp;amp;amp;amp;quot; rest-to-exercise transitions of 6-min duration at 50%Delta; and a maximal 2000-m ergometer time trial. Improvements (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in 2000-m ergometer performance and V O2peak occurred independently of groups (P = 0.8 and 0.42, respectively). LOW improved the power at LT (23.5 +/- 12.2 vs 5.1 +/- 5.0 W, P = 0.013) and power at a [blood lactate] of 4 mM (32.3 +/- 6.9 vs 13.1 +/- 3.7 W, P = 0.03) compared with MIX. The time constant and gain of the primary component were unchanged with training, whereas the gain of the V O2 slow component was reduced with training, but independently of group. Both LOW and MIX training programs improved performance and V O2peak by the same magnitude, whereas LOW attenuated the blood lactate response to a given exercise intensity more so than MIX.

Research paper thumbnail of Altitude Training May Improve Subsequent Endurance Performance In Elite Runners

Medicine & Science in Sports & Exercise, 2011

Research paper thumbnail of Determinants of 800-m and 1500-m Running Performance Using Allometric Models

Medicine & Science in Sports & Exercise, 2008

To identify the optimal aerobic determinants of elite, middle-distance running (MDR) performance,... more To identify the optimal aerobic determinants of elite, middle-distance running (MDR) performance, using proportional allometric models. Sixty-two national and international male and female 800-m and 1500-m runners undertook an incremental exercise test to volitional exhaustion. Mean submaximal running economy (ECON), speed at lactate threshold (speedLT), maximum oxygen uptake (.VO(2max)), and speed associated with .VO(2max) (speed.VO(2max)) were paired with best performance times recorded within 30 d. The data were analyzed using a proportional power-function ANCOVA model. The analysis identified significant differences in running speeds with main effects for sex and distance, with .VO(2max) and ECON as the covariate predictors (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). The results suggest a proportional curvilinear association between running speed and the ratio (.VO(2max).ECON(-0.71))(0.35) explaining 95.9% of the variance in performance. The model was cross-validated with a further group of highly trained MDR, demonstrating strong agreement (95% limits, 0.05 +/- 0.29 m.s(-1)) between predicted and actual performance speeds (R(2) = 93.6%). The model indicates that for a male 1500-m runner with a .VO(2max) of 3.81 L.min(-1) and ECON of 15 L.km(-1) to improve from 250 to 240 s, it would require a change in .VO(2max) from 3.81 to 4.28 L.min(-1), an increase of Delta0.47 L.min(-1). However, improving by the same margin of 10 s from 225 to 215 s would require a much greater increase in .VO(2max), from 5.14 to 5.85 L.min(-1), an increase of Delta0.71 L.min(-1) (where ECON remains constant). A proportional curvilinear ratio of .VO(2max) divided by ECON explains 95.9% of the variance in MDR performance.

Research paper thumbnail of Physiological assessment of isolated running does not directly replicate running capacity after triathlon-specific cycling

Journal of Sports Sciences, 2014

Triathlon running is affected by prior cycling and power output during triathlon cycling is varia... more Triathlon running is affected by prior cycling and power output during triathlon cycling is variable in nature. We compared constant and triathlon-specific variable power cycling and their effect on subsequent submaximal running physiology. Nine well-trained male triathletes (age 24.6 ± 4.6 years, _ VO 2peak 4.5 ± 0.4 L · min −1 ; mean ± SD) performed a submaximal incremental run test, under three conditions: no prior exercise and after a 1 h cycling trial at 65% of maximal aerobic power with either a constant or a variable power profile. The variable power protocol involved multiple 10-90 s intermittent efforts at 40-140% maximal aerobic power. During cycling, pulmonary ventilation (22%, ±14%; mean; ±90% confidence limits), blood lactate (179%, ±48%) and rating of perceived exertion (7.3%, ±10.2%) were all substantially higher during variable than during constant power cycling. At the start of the run, blood lactate was 64%, ±61% higher after variable compared to constant power cycling, which decreased running velocity at 4 mM lactate threshold by 0.6, ±0.9 km · h −1 . Physiological responses to incremental running are negatively affected by prior cycling and, to a greater extent, by variable compared to even-paced cycling. Testing and training of triathletes should account foe higher physiological cost of triathlon-specific cycling and its effect on subsequent running. 150 170 190 HR (b . min -1

Research paper thumbnail of Intrinsic and inducible resistance to hydrogen peroxide in Bifidobacterium species

Journal of Industrial Microbiology & Biotechnology, 2011

Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increase... more Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increased dramatically in recent years. As a result of their anaerobic nature, oxidative stress can pose a major challenge to maintaining viability of bifidobacteria during functional food storage. To better understand the oxidative stress response in two industrially important bifidobacteria species, we examined the response of three strains of B. longum and three strains of B. animalis subsp. lactis to hydrogen peroxide (H₂O₂). Each strain was exposed to a range of H₂O₂ concentrations (0-10 mM) to evaluate and compare intrinsic resistance to H₂O₂. Next, strains were tested for the presence of an inducible oxidative stress response by exposure to a sublethal H₂O₂ concentration for 20 or 60 min followed by challenge at a lethal H₂O₂ concentration. Results showed B. longum subsp. infantis ATCC 15697 had the highest level of intrinsic H₂O₂ resistance of all strains tested and B. animalis subsp. lactis BL-04 had the highest resistance among B. lactis strains. Inducible H₂O₂ resistance was detected in four strains, B. longum NCC2705, B. longum D2957, B. lactis RH-1, and B. lactis BL-04. Other strains showed either no difference or increased sensitivity to H₂O₂ after induction treatments. These data indicate that intrinsic and inducible resistance to hydrogen peroxide is strain specific in B. longum and B. lactis and suggest that for some strains, sublethal H₂O₂ treatments might help increase cell resistance to oxidative damage during production and storage of probiotic-containing foods.

Research paper thumbnail of Anaerobic Microbiology of Fresh Beef Packaged Under Modified Atmosphere or Vacuum

Journal of Food Science, 1993

... Our objectives were to: compare anaerobic and aerobic Authors Venugopal, MC Curdy, andJones a... more ... Our objectives were to: compare anaerobic and aerobic Authors Venugopal, MC Curdy, andJones are affilated with the Dept. ... 13 5 27 6 3 a Isolates obtained from aerobic plate count (APC), anaerobic jar plate count (AnJ), and anaerobic plate count (AnPC). ... J. Food Prot. ...

Research paper thumbnail of DEATH OF SALMONELLA SEROVARS, ESCHERICHIA COLI O157 : H7, STAPHYLOCOCCUS AUREUS AND LISTERIA MONOCYTOGENES DURING THE DRYING OF MEAT: A CASE STUDY USING BILTONG AND DROËWORS

Journal of Food Safety, 2008

Biltong and droëwors are ready-to-eat dried seasoned beef strips and sausages, respectively. Proc... more Biltong and droëwors are ready-to-eat dried seasoned beef strips and sausages, respectively. Procedures to meet process lethality requirements for these products have not been validated. The fate of Salmonella serovars, Escherichia coli O157 : H7, Staphylococcus aureus, and Listeria monocytogenes was evaluated during the manufacture and vacuum-packaged storage (7 days at 20-22C) of three lots each of biltong and droëwors. Acid-adapted pathogens were used as inocula (ca. 7 log CFU per sample for each pathogen). The biltong manufacturing process reduced pathogen levels from 1.2 to 3.8 log CFU (S. aureus and L. monocytogenes, respectively). Less lethality was achieved in making droëwors, probably because of the higher fat content. The manufacturing processes for biltong and droëwors achieved significant lethality. Combined with additional intervention steps and/or raw material testing, the processes would achieve mandated levels of pathogen destruction.

Research paper thumbnail of Efficacy of novel organic acid and hypochlorite treatments for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting

International Journal of Food Microbiology, 2000

This study investigated novel two-step organic acid/hypochlorite treatments as alternatives to 20... more This study investigated novel two-step organic acid/hypochlorite treatments as alternatives to 20000 ppm active chlorine (from calcium hypochlorite) for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting. Commercially available alfalfa seeds were inoculated with a five-strain E. coli O157:H7 mixture and dried to attain ca. 10(6) CFU/g of seeds. Seeds then underwent one of several soak treatments including: (1) 5% (v/v) lactic acid for 10 min at 42 degrees C; (2) 5% acetic acid (v/v) for 10 min at 42 degrees C; (3) 2.5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine (from calcium hypochlorite) for 15 min at 25 degrees C; (4) 5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine for 15 min at 25 degrees C; or (5) 20000 ppm active chlorine for 15 min at 25 degrees C. Each treatment reduced numbers of inoculum cells by about 6.0 log10 CFU/g as determined by plating on Sorbitol MacConkey agar (SMac). Plating on non-selective brain heart infusion agar (BHI) showed that treatments 1-4 reduced counts by 2.3-4.1 log10 CFU/g, thus indicating a large proportion of injured cells. Successive lactic acid and hypochlorite treatments (3 and 4) were more lethal than either organic acid alone (1 and 2). No surviving cells were detected on SMac or BHI following treatment with 20000 ppm active chlorine (treatment 5). Regardless of the previous treatment, E. coli O157:H7 counts increased to 10(7)-10(8) CFU/g during sprouting. Germination of seeds was not adversely affected by any of the treatments (germination &amp;amp;amp;amp;gt; 90%). Results of this study show that: (a) non-lethal cell injury must be considered when evaluating intervention treatments against E. coli O157:H7 on alfalfa seeds; (b) reductions of 2-4 log10 CFU/g can be attained without using 20000 ppm active chlorine; (c) successive lactic acid and hypochlorite treatments have greater lethality than organic acid treatments alone; and (d) none of the treatments tested can prevent regrowth of surviving E. coli O157:H7 during sprouting.

Research paper thumbnail of Modeling the survival of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium during fermentation, drying, and storage of soudjouk-style fermented sausage

International Journal of Food Microbiology, 2009

This study quantified and modeled the survival of Escherichia coli O157:H7, Listeria monocytogene... more This study quantified and modeled the survival of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Typhimurium in soudjouk-style fermented sausage during fermentation, drying, and storage. Batter prepared from ground beef (20% fat), seasonings, starter culture, and dextrose was separately inoculated with a multi-strain mixture of each pathogen to an initial inoculum of ca. 6.5 log 10 CFU/g in the batter. The sausages were subsequently fermented at 24°C with a relative humidity (RH) of 90% to 95% for 3 to 5 days to ca. pH 5.2, pH 4.9 or pH 4.6, then dried at 22°C to a w 0.92, a w 0.89, or a w 0.86, respectively, and then stored at 4, 21, or 30°C for up to 60 days. Lethality of the three pathogens was modeled as a function of pH, a w and/or storage temperature. During fermentation to pH 5.2 to pH 4.6, cell reductions ranged from 0 to 0.9 log 10 CFU/g for E. coli O157:H7, 0.1 to 0.5 log 10 CFU/g for L. monocytogenes, and 0 to 2.2 log 10 CFU/g for S. Typhimurium. Subsequent drying of sausages of pH 5.2 to pH 4.6 at 22°C with 80% to 85% RH for 3 to 7 days to a w of 0.92 to a w 0.86 resulted in additional reductions that ranged from 0 to 3.5 log 10 CFU/g for E. coli O157:H7, 0 to 0.4 log 10 CFU/g for L. monocytogenes, and 0.3 to 2.4 log 10 CFU/g for S. Typhimurium. During storage at 4, 21, or 30°C the reduction rates of the three pathogens were generally higher (p b 0.05) in sausages with lower pH and lower a w that were stored at higher temperatures. Polynomial equations were developed to describe the inactivation of the three pathogens during fermentation, drying, and storage. The applicability of the resulting models for fermented sausage was evaluated by comparing model predictions with published data. Pathogen reductions estimated by the models for E. coli O157:H7 and S. Typhimurium were comparable to 67% and 73% of published data, respectively. Due to limited published data for L. monocytogenes, the models for L. monocytogenes would need additional validations. Results of pathogen reductions from this study may be used as a reference to assist manufacturers of soudjouk-style sausages to adopt manufacturing processes that meet the regulatory requirements. The resulting models may also be used for estimating the survival of E. coli O157:H7 and S. Typhimurium in other similar fermented sausage during fermentation and storage.

Research paper thumbnail of Differentiation of lactate-fermenting, gas-producing Clostridium spp. isolated from milk

International Journal of Food Microbiology, 1998

Endospores of Clostridium spp. capable of producing gas in a lactate-containing medium were enume... more Endospores of Clostridium spp. capable of producing gas in a lactate-containing medium were enumerated from 14 pasteurized milk samples from Wisconsin cheese plants. Concentrations of endospores of lactate-fermenting, gas-producing

Research paper thumbnail of Viability of multi-strain mixtures of Listeria monocytogenes, Salmonella typhimurium, or Escherichia coli O157:H7 inoculated into the batter or onto the surface of a soudjouk-style fermented semi-dry sausage☆

Research paper thumbnail of The reliability of running economy expressed as oxygen cost and energy cost in trained distance runners

Applied Physiology, Nutrition, and Metabolism, 2013

This study assessed the between-test reliability of oxygen cost (O C ) and energy cost (E C ) in ... more This study assessed the between-test reliability of oxygen cost (O C ) and energy cost (E C ) in distance runners, and contrasted it with the smallest worthwhile change (SWC) of these measures. O C and E C displayed similar levels of within-subject variation (typical error < 3.85%). However, the typical error (2.75% vs 2.74%) was greater than the SWC (1.38% vs 1.71%) for both O C and E C , respectively, indicating insufficient sensitivity to confidently detect small, but meaningful, changes in O C and E C .

Research paper thumbnail of Escherichia coli Contamination of Vegetables Grown in Soils Fertilized with Noncomposted Bovine Manure: Garden-Scale Studies

Applied and Environmental Microbiology, 2004

In this study we tested the validity of the National Organic Program (NOP) requirement for a &amp... more In this study we tested the validity of the National Organic Program (NOP) requirement for a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day interval between application of noncomposted manure and harvesting of vegetables grown in manure-fertilized soil. Noncomposted bovine manure was applied to 9.3-m2 plots at three Wisconsin sites (loamy sand, silt loam, and silty clay loam) prior to spring and summer planting of carrots, radishes, and lettuce. Soil and washed (30 s under running tap water) vegetables were analyzed for indigenous Escherichia coli. Within 90 days, the level of E. coli in manure-fertilized soil generally decreased by about 3 log CFU/g from initial levels of 4.2 to 4.4 log CFU/g. Low levels of E. coli generally persisted in manure-fertilized soil for more than 100 days and were detected in enriched soil from all three sites 132 to 168 days after manure application. For carrots and lettuce, at least one enrichment-negative sample was obtained &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or =100 days after manure application for 63 and 88% of the treatments, respectively. The current &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day limit provided an even greater likelihood of not detecting E. coli on carrots (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1 enrichment-negative result for 100% of the treatments). The rapid maturation of radishes prevented conclusive evaluation of a 100- or 120-day application-to-harvest interval. The absolute absence of E. coli from vegetables harvested from manure-fertilized Wisconsin soils may not be ensured solely by adherence to the NOP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day limit. Unless pathogens are far better at colonizing vegetables than indigenous E. coli strains are, it appears that the risk of contamination for vegetables grown in Wisconsin soils would be elevated only slightly by reducing the NOP requirement to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =100 days.

Research paper thumbnail of Adjusting athletes' body mass index to better reflect adiposity in epidemiological research

Journal of Sports Sciences, 2010

The aim of the present study was to identify when body mass index (BMI) is unlikely to be a valid... more The aim of the present study was to identify when body mass index (BMI) is unlikely to be a valid measure of adiposity in athletic populations and to propose a simple adjustment that will allow the BMI of athletes to reflect the adiposity normally associated with non-athletic populations. Using data from three previously published studies containing 236 athletes from seven sports and 293 age-matched controls, the association between adiposity (sum of 4 skinfold thicknesses, in millimetres) and BMI was explored using correlation, linear regression, and analysis of covariance (ANCOVA). As anticipated, there were strong positive correlations (r = 0.83 for both men and women) and slope parameters between adiposity and BMI in age-matched controls from Study 1 (all P &amp;amp;lt; 0.001). The standard of sport participation reduced these associations. Of the correlations and linear-regression slope parameters between adiposity and BMI in the sports from Studies 2 and 3, although still positive in most groups, less than half of the correlations and slope parameters were statistically significant. When data from the three studies were combined, the ANCOVA identified that the BMI slope parameter of controls (5.81 mm (kg m(-2))(-1)) was greater than the BMI slope parameter for sports (2.62 mm (kg m(-2))(-1)) and middle-distance runners (0.94 mm (kg m(-2))(-1)) (P &amp;amp;lt; 0.001). Based on these contrasting associations, we calculated how the BMI of athletes can be adjusted to reflect the same adiposity associated with age-matched controls. This simple adjustment allows the BMI of athletes and non-athletes to be used with greater confidence when investigating the effect of BMI as a risk factor in epidemiological research.

Research paper thumbnail of Thermal tolerance of O157 and non-O157 Shiga toxigenic strains of Escherichia coli, Salmonella, and potential pathogen surrogates, in frankfurter batter and ground beef of varying fat levels

Journal of food protection, 2014

The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with ill... more The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. We compared the thermal tolerance (D55°C) of three or more strains of each of these six non-O157 STEC serogroups with five strains of O157:H7 STEC in 7% fat ground beef. D55°C was also determined for at least one heat-tolerant STEC strain per serogroup in 15 and 27% fat ground beef. D55°C of single-pathogen cocktails of O157 and non-O157 STEC, Salmonella, and potential pathogen surrogates, Pediococcus acidilactici and Staphylococcus carnosus, was determined in 7, 15, and 27% fat ground beef and in frankfurter batter. Samples (25 g) were heated for up to 120 min at 55°C, survivors were enumerated, and log CFU per gram was plotted versus time. There were significant differences in D55°C across all STEC strains heated in 7% fat ground beef (P < 0.05), but no non-O157 STEC strain had D55°C greater than the range observed for O157 STEC. D55°C ...

Research paper thumbnail of Sodium bicarbonate improves swimming performance

International journal of sports medicine, 2008

Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity... more Sodium bicarbonate ingestion has been shown to improve performance in single-bout, high intensity events, probably due to an increase in buffering capacity, but its influence on single-bout swimming performance has not been investigated. The effects of sodium bicarbonate supplementation on 200 m freestyle swimming performance were investigated in elite male competitors. Following a randomised, double blind counterbalanced design, 9 swimmers completed maximal effort swims on 3 separate occasions: a control trial (C); after ingestion of sodium bicarbonate (SB: NaHCO3 300 mg . kg (-1) body mass); and after ingestion of a placebo (P: CaCO3 200 mg . kg (-1) body mass). The SB and P agents were packed in gelatine capsules and ingested 90 - 60 min prior to each 200 m swim. Mean 200 m performance times were significantly faster for SB than C or P (1 : 52.2 +/- 4.7; 1 : 53.7 +/- 3.8; 1 : 54.0 +/- 3.6 min : ss; p < 0.05). Base excess, pH and blood bicarbonate were all elevated pre-exercise...

Research paper thumbnail of Growth of Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus on cheese during extended storage at 25°C

Journal of food protection, 2014

Potentially hazardous foods require time/temperature control for safety. According to the U.S. Fo... more Potentially hazardous foods require time/temperature control for safety. According to the U.S. Food and Drug Administration Food Code, most cheeses are potentially hazardous foods based on pH and water activity, and a product assessment is required to evaluate safety of storage >6 h at 21°C. We tested the ability of 67 market cheeses to support growth of Listeria monocytogenes (LM), Salmonella spp. (SALM), Escherichia coli O157:H7 (EC), and Staphylococcus aureus (SA) over 15 days at 25°C. Hard (Asiago and Cheddar), semi-hard (Colby and Havarti), and soft cheeses (mozzarella and Mexican-style), and reduced-sodium or reduced-fat types were tested. Single-pathogen cocktails were prepared and individually inoculated onto cheese slices (∼10(5) CFU/g). Cocktails were 10 strains of L. monocytogenes, 6 of Salmonella spp., or 5 of E. coli O157:H7 or S. aureus. Inoculated slices were vacuum packaged and stored at 25°C for ≤ 15 days, with surviving inocula enumerated every 3 days. Percent s...

Research paper thumbnail of Evaluation of Small-Scale Hot-Water Post-Packaging Pasteurization Treatments for Destruction of Listeria monocytogenes on Ready-To-Eat Beef Snack Sticks and Natural Casing Wieners

This study was conducted to evaluate small-scale hot-water postpackaging pasteurization (PPP) as ... more This study was conducted to evaluate small-scale hot-water postpackaging pasteurization (PPP) as a postlethality (post- cooking) treatment for Listeria monocytogenes on ready-to-eat beef snack sticks and natural-casing wieners. Using a com- mercially available plastic packaging film specifically designed for PPP applications and 2.8 liters of boiling water (1008C) in a sauce pan on a hot plate, an average reduction in

Research paper thumbnail of Altitude Training for Elite Endurance Performance

Current Sports Medicine Reports, 2012

Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of... more Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of performance on return to sea level. The purpose of the current review article was to update and evaluate recent literature relevant to the practical application of altitude training for endurance athletes. Consequently, the literature can be considered in either of two categories: performance-led investigations or mechanistic advancements/insights. Each section discusses the relevant literature and proposes future directions where appropriate.

Research paper thumbnail of Physiological and Performance Effects of Low- versus Mixed-Intensity Rowing Training

Medicine & Science in Sports & Exercise, 2008

To examine the impact of low-intensity and a mixture of low- and high-intensity training on physi... more To examine the impact of low-intensity and a mixture of low- and high-intensity training on physiological and performance responses in rowing. Eighteen experienced rowers undertook a 12-wk program of 100% &amp;amp;amp;amp;amp;amp;amp;amp;lt; or = lactate threshold (LT) training (LOW) or 70% training at &amp;amp;amp;amp;amp;amp;amp;amp;lt; or = LT and 30% at halfway (50%Delta) between the V O2 at LT and V O2peak (MIX). Responses were assessed before and after training by a progressive exercise test to exhaustion; multiple &amp;amp;amp;amp;amp;amp;amp;amp;quot;square-wave&amp;amp;amp;amp;amp;amp;amp;amp;quot; rest-to-exercise transitions of 6-min duration at 50%Delta; and a maximal 2000-m ergometer time trial. Improvements (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) in 2000-m ergometer performance and V O2peak occurred independently of groups (P = 0.8 and 0.42, respectively). LOW improved the power at LT (23.5 +/- 12.2 vs 5.1 +/- 5.0 W, P = 0.013) and power at a [blood lactate] of 4 mM (32.3 +/- 6.9 vs 13.1 +/- 3.7 W, P = 0.03) compared with MIX. The time constant and gain of the primary component were unchanged with training, whereas the gain of the V O2 slow component was reduced with training, but independently of group. Both LOW and MIX training programs improved performance and V O2peak by the same magnitude, whereas LOW attenuated the blood lactate response to a given exercise intensity more so than MIX.

Research paper thumbnail of Altitude Training May Improve Subsequent Endurance Performance In Elite Runners

Medicine & Science in Sports & Exercise, 2011

Research paper thumbnail of Determinants of 800-m and 1500-m Running Performance Using Allometric Models

Medicine & Science in Sports & Exercise, 2008

To identify the optimal aerobic determinants of elite, middle-distance running (MDR) performance,... more To identify the optimal aerobic determinants of elite, middle-distance running (MDR) performance, using proportional allometric models. Sixty-two national and international male and female 800-m and 1500-m runners undertook an incremental exercise test to volitional exhaustion. Mean submaximal running economy (ECON), speed at lactate threshold (speedLT), maximum oxygen uptake (.VO(2max)), and speed associated with .VO(2max) (speed.VO(2max)) were paired with best performance times recorded within 30 d. The data were analyzed using a proportional power-function ANCOVA model. The analysis identified significant differences in running speeds with main effects for sex and distance, with .VO(2max) and ECON as the covariate predictors (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). The results suggest a proportional curvilinear association between running speed and the ratio (.VO(2max).ECON(-0.71))(0.35) explaining 95.9% of the variance in performance. The model was cross-validated with a further group of highly trained MDR, demonstrating strong agreement (95% limits, 0.05 +/- 0.29 m.s(-1)) between predicted and actual performance speeds (R(2) = 93.6%). The model indicates that for a male 1500-m runner with a .VO(2max) of 3.81 L.min(-1) and ECON of 15 L.km(-1) to improve from 250 to 240 s, it would require a change in .VO(2max) from 3.81 to 4.28 L.min(-1), an increase of Delta0.47 L.min(-1). However, improving by the same margin of 10 s from 225 to 215 s would require a much greater increase in .VO(2max), from 5.14 to 5.85 L.min(-1), an increase of Delta0.71 L.min(-1) (where ECON remains constant). A proportional curvilinear ratio of .VO(2max) divided by ECON explains 95.9% of the variance in MDR performance.

Research paper thumbnail of Physiological assessment of isolated running does not directly replicate running capacity after triathlon-specific cycling

Journal of Sports Sciences, 2014

Triathlon running is affected by prior cycling and power output during triathlon cycling is varia... more Triathlon running is affected by prior cycling and power output during triathlon cycling is variable in nature. We compared constant and triathlon-specific variable power cycling and their effect on subsequent submaximal running physiology. Nine well-trained male triathletes (age 24.6 ± 4.6 years, _ VO 2peak 4.5 ± 0.4 L · min −1 ; mean ± SD) performed a submaximal incremental run test, under three conditions: no prior exercise and after a 1 h cycling trial at 65% of maximal aerobic power with either a constant or a variable power profile. The variable power protocol involved multiple 10-90 s intermittent efforts at 40-140% maximal aerobic power. During cycling, pulmonary ventilation (22%, ±14%; mean; ±90% confidence limits), blood lactate (179%, ±48%) and rating of perceived exertion (7.3%, ±10.2%) were all substantially higher during variable than during constant power cycling. At the start of the run, blood lactate was 64%, ±61% higher after variable compared to constant power cycling, which decreased running velocity at 4 mM lactate threshold by 0.6, ±0.9 km · h −1 . Physiological responses to incremental running are negatively affected by prior cycling and, to a greater extent, by variable compared to even-paced cycling. Testing and training of triathletes should account foe higher physiological cost of triathlon-specific cycling and its effect on subsequent running. 150 170 190 HR (b . min -1

Research paper thumbnail of Intrinsic and inducible resistance to hydrogen peroxide in Bifidobacterium species

Journal of Industrial Microbiology & Biotechnology, 2011

Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increase... more Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increased dramatically in recent years. As a result of their anaerobic nature, oxidative stress can pose a major challenge to maintaining viability of bifidobacteria during functional food storage. To better understand the oxidative stress response in two industrially important bifidobacteria species, we examined the response of three strains of B. longum and three strains of B. animalis subsp. lactis to hydrogen peroxide (H₂O₂). Each strain was exposed to a range of H₂O₂ concentrations (0-10 mM) to evaluate and compare intrinsic resistance to H₂O₂. Next, strains were tested for the presence of an inducible oxidative stress response by exposure to a sublethal H₂O₂ concentration for 20 or 60 min followed by challenge at a lethal H₂O₂ concentration. Results showed B. longum subsp. infantis ATCC 15697 had the highest level of intrinsic H₂O₂ resistance of all strains tested and B. animalis subsp. lactis BL-04 had the highest resistance among B. lactis strains. Inducible H₂O₂ resistance was detected in four strains, B. longum NCC2705, B. longum D2957, B. lactis RH-1, and B. lactis BL-04. Other strains showed either no difference or increased sensitivity to H₂O₂ after induction treatments. These data indicate that intrinsic and inducible resistance to hydrogen peroxide is strain specific in B. longum and B. lactis and suggest that for some strains, sublethal H₂O₂ treatments might help increase cell resistance to oxidative damage during production and storage of probiotic-containing foods.

Research paper thumbnail of Anaerobic Microbiology of Fresh Beef Packaged Under Modified Atmosphere or Vacuum

Journal of Food Science, 1993

... Our objectives were to: compare anaerobic and aerobic Authors Venugopal, MC Curdy, andJones a... more ... Our objectives were to: compare anaerobic and aerobic Authors Venugopal, MC Curdy, andJones are affilated with the Dept. ... 13 5 27 6 3 a Isolates obtained from aerobic plate count (APC), anaerobic jar plate count (AnJ), and anaerobic plate count (AnPC). ... J. Food Prot. ...

Research paper thumbnail of DEATH OF SALMONELLA SEROVARS, ESCHERICHIA COLI O157 : H7, STAPHYLOCOCCUS AUREUS AND LISTERIA MONOCYTOGENES DURING THE DRYING OF MEAT: A CASE STUDY USING BILTONG AND DROËWORS

Journal of Food Safety, 2008

Biltong and droëwors are ready-to-eat dried seasoned beef strips and sausages, respectively. Proc... more Biltong and droëwors are ready-to-eat dried seasoned beef strips and sausages, respectively. Procedures to meet process lethality requirements for these products have not been validated. The fate of Salmonella serovars, Escherichia coli O157 : H7, Staphylococcus aureus, and Listeria monocytogenes was evaluated during the manufacture and vacuum-packaged storage (7 days at 20-22C) of three lots each of biltong and droëwors. Acid-adapted pathogens were used as inocula (ca. 7 log CFU per sample for each pathogen). The biltong manufacturing process reduced pathogen levels from 1.2 to 3.8 log CFU (S. aureus and L. monocytogenes, respectively). Less lethality was achieved in making droëwors, probably because of the higher fat content. The manufacturing processes for biltong and droëwors achieved significant lethality. Combined with additional intervention steps and/or raw material testing, the processes would achieve mandated levels of pathogen destruction.

Research paper thumbnail of Efficacy of novel organic acid and hypochlorite treatments for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting

International Journal of Food Microbiology, 2000

This study investigated novel two-step organic acid/hypochlorite treatments as alternatives to 20... more This study investigated novel two-step organic acid/hypochlorite treatments as alternatives to 20000 ppm active chlorine (from calcium hypochlorite) for eliminating Escherichia coli O157:H7 from alfalfa seeds prior to sprouting. Commercially available alfalfa seeds were inoculated with a five-strain E. coli O157:H7 mixture and dried to attain ca. 10(6) CFU/g of seeds. Seeds then underwent one of several soak treatments including: (1) 5% (v/v) lactic acid for 10 min at 42 degrees C; (2) 5% acetic acid (v/v) for 10 min at 42 degrees C; (3) 2.5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine (from calcium hypochlorite) for 15 min at 25 degrees C; (4) 5% lactic acid for 10 min at 42 degrees C followed by 2000 ppm active chlorine for 15 min at 25 degrees C; or (5) 20000 ppm active chlorine for 15 min at 25 degrees C. Each treatment reduced numbers of inoculum cells by about 6.0 log10 CFU/g as determined by plating on Sorbitol MacConkey agar (SMac). Plating on non-selective brain heart infusion agar (BHI) showed that treatments 1-4 reduced counts by 2.3-4.1 log10 CFU/g, thus indicating a large proportion of injured cells. Successive lactic acid and hypochlorite treatments (3 and 4) were more lethal than either organic acid alone (1 and 2). No surviving cells were detected on SMac or BHI following treatment with 20000 ppm active chlorine (treatment 5). Regardless of the previous treatment, E. coli O157:H7 counts increased to 10(7)-10(8) CFU/g during sprouting. Germination of seeds was not adversely affected by any of the treatments (germination &amp;amp;amp;amp;gt; 90%). Results of this study show that: (a) non-lethal cell injury must be considered when evaluating intervention treatments against E. coli O157:H7 on alfalfa seeds; (b) reductions of 2-4 log10 CFU/g can be attained without using 20000 ppm active chlorine; (c) successive lactic acid and hypochlorite treatments have greater lethality than organic acid treatments alone; and (d) none of the treatments tested can prevent regrowth of surviving E. coli O157:H7 during sprouting.

Research paper thumbnail of Modeling the survival of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium during fermentation, drying, and storage of soudjouk-style fermented sausage

International Journal of Food Microbiology, 2009

This study quantified and modeled the survival of Escherichia coli O157:H7, Listeria monocytogene... more This study quantified and modeled the survival of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Typhimurium in soudjouk-style fermented sausage during fermentation, drying, and storage. Batter prepared from ground beef (20% fat), seasonings, starter culture, and dextrose was separately inoculated with a multi-strain mixture of each pathogen to an initial inoculum of ca. 6.5 log 10 CFU/g in the batter. The sausages were subsequently fermented at 24°C with a relative humidity (RH) of 90% to 95% for 3 to 5 days to ca. pH 5.2, pH 4.9 or pH 4.6, then dried at 22°C to a w 0.92, a w 0.89, or a w 0.86, respectively, and then stored at 4, 21, or 30°C for up to 60 days. Lethality of the three pathogens was modeled as a function of pH, a w and/or storage temperature. During fermentation to pH 5.2 to pH 4.6, cell reductions ranged from 0 to 0.9 log 10 CFU/g for E. coli O157:H7, 0.1 to 0.5 log 10 CFU/g for L. monocytogenes, and 0 to 2.2 log 10 CFU/g for S. Typhimurium. Subsequent drying of sausages of pH 5.2 to pH 4.6 at 22°C with 80% to 85% RH for 3 to 7 days to a w of 0.92 to a w 0.86 resulted in additional reductions that ranged from 0 to 3.5 log 10 CFU/g for E. coli O157:H7, 0 to 0.4 log 10 CFU/g for L. monocytogenes, and 0.3 to 2.4 log 10 CFU/g for S. Typhimurium. During storage at 4, 21, or 30°C the reduction rates of the three pathogens were generally higher (p b 0.05) in sausages with lower pH and lower a w that were stored at higher temperatures. Polynomial equations were developed to describe the inactivation of the three pathogens during fermentation, drying, and storage. The applicability of the resulting models for fermented sausage was evaluated by comparing model predictions with published data. Pathogen reductions estimated by the models for E. coli O157:H7 and S. Typhimurium were comparable to 67% and 73% of published data, respectively. Due to limited published data for L. monocytogenes, the models for L. monocytogenes would need additional validations. Results of pathogen reductions from this study may be used as a reference to assist manufacturers of soudjouk-style sausages to adopt manufacturing processes that meet the regulatory requirements. The resulting models may also be used for estimating the survival of E. coli O157:H7 and S. Typhimurium in other similar fermented sausage during fermentation and storage.

Research paper thumbnail of Differentiation of lactate-fermenting, gas-producing Clostridium spp. isolated from milk

International Journal of Food Microbiology, 1998

Endospores of Clostridium spp. capable of producing gas in a lactate-containing medium were enume... more Endospores of Clostridium spp. capable of producing gas in a lactate-containing medium were enumerated from 14 pasteurized milk samples from Wisconsin cheese plants. Concentrations of endospores of lactate-fermenting, gas-producing

Research paper thumbnail of Viability of multi-strain mixtures of Listeria monocytogenes, Salmonella typhimurium, or Escherichia coli O157:H7 inoculated into the batter or onto the surface of a soudjouk-style fermented semi-dry sausage☆

Research paper thumbnail of The reliability of running economy expressed as oxygen cost and energy cost in trained distance runners

Applied Physiology, Nutrition, and Metabolism, 2013

This study assessed the between-test reliability of oxygen cost (O C ) and energy cost (E C ) in ... more This study assessed the between-test reliability of oxygen cost (O C ) and energy cost (E C ) in distance runners, and contrasted it with the smallest worthwhile change (SWC) of these measures. O C and E C displayed similar levels of within-subject variation (typical error < 3.85%). However, the typical error (2.75% vs 2.74%) was greater than the SWC (1.38% vs 1.71%) for both O C and E C , respectively, indicating insufficient sensitivity to confidently detect small, but meaningful, changes in O C and E C .

Research paper thumbnail of Escherichia coli Contamination of Vegetables Grown in Soils Fertilized with Noncomposted Bovine Manure: Garden-Scale Studies

Applied and Environmental Microbiology, 2004

In this study we tested the validity of the National Organic Program (NOP) requirement for a &amp... more In this study we tested the validity of the National Organic Program (NOP) requirement for a &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day interval between application of noncomposted manure and harvesting of vegetables grown in manure-fertilized soil. Noncomposted bovine manure was applied to 9.3-m2 plots at three Wisconsin sites (loamy sand, silt loam, and silty clay loam) prior to spring and summer planting of carrots, radishes, and lettuce. Soil and washed (30 s under running tap water) vegetables were analyzed for indigenous Escherichia coli. Within 90 days, the level of E. coli in manure-fertilized soil generally decreased by about 3 log CFU/g from initial levels of 4.2 to 4.4 log CFU/g. Low levels of E. coli generally persisted in manure-fertilized soil for more than 100 days and were detected in enriched soil from all three sites 132 to 168 days after manure application. For carrots and lettuce, at least one enrichment-negative sample was obtained &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or =100 days after manure application for 63 and 88% of the treatments, respectively. The current &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day limit provided an even greater likelihood of not detecting E. coli on carrots (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =1 enrichment-negative result for 100% of the treatments). The rapid maturation of radishes prevented conclusive evaluation of a 100- or 120-day application-to-harvest interval. The absolute absence of E. coli from vegetables harvested from manure-fertilized Wisconsin soils may not be ensured solely by adherence to the NOP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =120-day limit. Unless pathogens are far better at colonizing vegetables than indigenous E. coli strains are, it appears that the risk of contamination for vegetables grown in Wisconsin soils would be elevated only slightly by reducing the NOP requirement to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =100 days.

Research paper thumbnail of Adjusting athletes' body mass index to better reflect adiposity in epidemiological research

Journal of Sports Sciences, 2010

The aim of the present study was to identify when body mass index (BMI) is unlikely to be a valid... more The aim of the present study was to identify when body mass index (BMI) is unlikely to be a valid measure of adiposity in athletic populations and to propose a simple adjustment that will allow the BMI of athletes to reflect the adiposity normally associated with non-athletic populations. Using data from three previously published studies containing 236 athletes from seven sports and 293 age-matched controls, the association between adiposity (sum of 4 skinfold thicknesses, in millimetres) and BMI was explored using correlation, linear regression, and analysis of covariance (ANCOVA). As anticipated, there were strong positive correlations (r = 0.83 for both men and women) and slope parameters between adiposity and BMI in age-matched controls from Study 1 (all P &amp;amp;lt; 0.001). The standard of sport participation reduced these associations. Of the correlations and linear-regression slope parameters between adiposity and BMI in the sports from Studies 2 and 3, although still positive in most groups, less than half of the correlations and slope parameters were statistically significant. When data from the three studies were combined, the ANCOVA identified that the BMI slope parameter of controls (5.81 mm (kg m(-2))(-1)) was greater than the BMI slope parameter for sports (2.62 mm (kg m(-2))(-1)) and middle-distance runners (0.94 mm (kg m(-2))(-1)) (P &amp;amp;lt; 0.001). Based on these contrasting associations, we calculated how the BMI of athletes can be adjusted to reflect the same adiposity associated with age-matched controls. This simple adjustment allows the BMI of athletes and non-athletes to be used with greater confidence when investigating the effect of BMI as a risk factor in epidemiological research.