Running Economy Benefits of Advanced Footwear Technology are Similar for Treadmill and Overground Running

Running economy (RE) is a key marker of distance running performance, as it indicates the oxygen cost required to run at a given speed. Multiple laboratory studies on treadmills have shown that new advanced footwear technology (AFT) improves RE. However, no studies have quantified the benefit of AFT in overground running. PURPOSE: Determine the impact of running surface (treadmill vs. overground) on the RE benefits of AFT. METHODS: Seventeen trained runners (9 male, \u3c 17:30 5k; 8 female, \u3c 20:20 5k) reported for two separate visits, which included one session on a stiff treadmill indoors and one session overground on a concrete path outdoors. Each visit, subjects completed 4 × 5-minute trials at 16 km·hr-1 (male) and 14 km·hr-1 (female) wearing both an advanced shoe (AFT) and a control shoe (CTRL). Test speeds were below the runners’ estimated lactate threshold and confirmed by blood lactate samples \u3c 4 mmol·L-1. Shoes were tested in duplicate on each visit in either an ABBA or BAAB sequence, counterbalanced across subjects. Surface test sequence (treadmill vs. overground) was also counterbalanced. RE (ml·kg-1·km-1) was calculated as oxygen consumption (VO2) normalized to running speed. VO2 was measured with a calibrated portable metabolic cart, and the average values of the final 2 minutes of each 5-minute trial were calculated. Treadmill running speed was fixed, and overground running speed was paced by an electronic scooter with cruise control. RE was analyzed by a 2-way (shoe × running surface) repeated measures ANOVA. RESULTS: There was a significant main effect for shoe (p \u3c .001) with AFT (174.2 ± 14.2 ml·kg-1·km-1) offering a 3.6 ± 1.6% RE benefit relative to CTRL (180.8 ± 14.8 ml·kg-1·km-1) independent of surface. There was also a significant main effect (p = 0.001) for surface, as RE was 6.8 ± 7.0% better during the overground (171.2 ± 16.8 ml·kg-1·km-1) condition compared to treadmill (183.9 ± 15.0 ml·kg-1·km-1), independent of shoe. However, there was no shoe × surface interaction (p = 0.289), as the RE benefit of AFT was 3.1 ± 2.7% overground and 4.1 ± 2.9% on the treadmill. CONCLUSIONS: These findings suggest that the RE benefits of AFT shown previously in a laboratory setting may be consistent across overground road conditions outdoors. As such, footwear researchers and manufacturers can more confidently translate laboratory findings to real world settings. It appears the portable metabolic cart used in this study may read lower RE values outdoors than in a laboratory setting, but this did not appear to impact the ability of the device to discern economy difference between footwear conditions

Multi-proxy constraints on the significance of covariant δ13C values in carbonate and organic carbon during the early Mississippian

This study investigates the covariation between carbonate and organic δ13C values in a proximal to distal transect of four outcrops in the Madison Limestone in the Western United States Rockies, combined with δ34S values of carbonate associated sulphate, the concentration of acid-insoluble material and measurements of total organic carbon. These new geochemical datasets not only allow for an evaluation of carbon isotope covariance during one of the largest perturbations to the global carbon cycle over the past 550 Myr, but also constrain the cause of the excursion in carbonate δ13C values. The results support the hypothesis that a period of anoxia did not play a role in generating the positive carbonate δ13C values, but rather favour interpretations by previous workers that the proliferation of land plants destabilized the Carboniferous carbon cycle, setting the stage for a significant change in the carbonate δ13C values of contemporaneous marine carbonates. These results also demonstrate that one of the largest perturbations to the global carbon cycle did not produce synchronous variations in carbonate and organic δ13C values, emphasizing the importance of local depositional controls on carbon isotope covariance in the geological record in both modern and ancient environments

The time-dependent expression of keratins 5 and 13 during the reepithelialization of human skin wounds

The time-dependent reepithelialization of 55 human surgical skin wounds with a wound age between 8h and more than 2 months was investigated by the immunohistochemical localization of cytokeratins 5 and 13. A complete, rebuilt epidermal layer over the wound area was first detectable in a 5-day-old wound, while all wounds of more than 18 days duration contained a completely reepithelialized wound area. Between 5 and 18 days the basal layer of keratinocytes showed — in contrast to normal skin — only some cells positive for cytokeratin 5. In some, but not all lesions with a wound age of 13 days or more, a basal cell layer completely staining for cytokeratin 5 was demonstrable. This staining pattern was found in all skin wounds with a wound age of more than 23 days. The immunohistochemical detection of cytokeratin 13 which can be observed regularly in non-cornifying squamous epithelia provides no information for the time-estimation of human skin wounds, since no significant temporary expression of this polypeptide seems to occur during the healing of human skin wounds

The time-dependent rearrangement of the epithelial basement membrane in human skin wounds

In 62 human skin wounds (surgical wounds, stab wounds and lacerations after surgical treatment) we analyzed the immunohistochemical localization of collagen IV in the epithelial basement membrane. In 27 of these wounds the distribution of collagen VII, which represents a specific component of the basement membrane of stratified epithelia, was also analyzed. We were able to demonstrate a virtually identical co-distribution of both collagen IV and VII in the wound area with no significant time-dependent differences in the appearance of both collagen types. Fragments of the epithelial basement membrane could be detected in the wound area from as early as 4 days after wounding and after 8 days a complete restitution of the epithelial basement membrane was observed. In all cases with a wound age of more than 21 days the basement membrane was completely reformed over the former lesional area. The period between 8 and 21 days after wounding was characterized by a wide variability ranging from complete restitution to deposition of basement membrane fragments or total lack of the epidermal basement membrane

Methods for confidence interval estimation of a ratio parameter with application to location quotients

BACKGROUND: The location quotient (LQ) ratio, a measure designed to quantify and benchmark the degree of relative concentration of an activity in the analysis of area localization, has received considerable attention in the geographic and economics literature. This index can also naturally be applied in the context of population health to quantify and compare health outcomes across spatial domains. However, one commonly observed limitation of LQ is its widespread use as only a point estimate without an accompanying confidence interval. METHODS: In this paper we present statistical methods that can be used to construct confidence intervals for location quotients. The delta and Fieller's methods are generic approaches for a ratio parameter and the generalized linear modelling framework is a useful re-parameterization particularly helpful for generating profile-likelihood based confidence intervals for the location quotient. A simulation experiment is carried out to assess the performance of each of the analytic approaches and a health utilization data set is used for illustration. RESULTS: Both the simulation results as well as the findings from the empirical data show that the different analytical methods produce very similar confidence limits for location quotients. When incidence of outcome is not rare and sample sizes are large, the confidence limits are almost indistinguishable. The confidence limits from the generalized linear model approach might be preferable in small sample situations. CONCLUSION: LQ is a useful measure which allows quantification and comparison of health and other outcomes across defined geographical regions. It is a very simple index to compute and has a straightforward interpretation. Reporting this estimate with appropriate confidence limits using methods presented in this paper will make the measure particularly attractive for policy and decision makers

Estimation of age- and stage-specific Catalan breast cancer survival functions using US and Catalan survival data

<p>Abstract</p> <p>Background</p> <p>During the last part of the 1990s the chance of surviving breast cancer increased. Changes in survival functions reflect a mixture of effects. Both, the introduction of adjuvant treatments and early screening with mammography played a role in the decline in mortality. Evaluating the contribution of these interventions using mathematical models requires survival functions before and after their introduction. Furthermore, required survival functions may be different by age groups and are related to disease stage at diagnosis. Sometimes detailed information is not available, as was the case for the region of Catalonia (Spain). Then one may derive the functions using information from other geographical areas. This work presents the methodology used to estimate age- and stage-specific Catalan breast cancer survival functions from scarce Catalan survival data by adapting the age- and stage-specific US functions.</p> <p>Methods</p> <p>Cubic splines were used to smooth data and obtain continuous hazard rate functions. After, we fitted a Poisson model to derive hazard ratios. The model included time as a covariate. Then the hazard ratios were applied to US survival functions detailed by age and stage to obtain Catalan estimations.</p> <p>Results</p> <p>We started estimating the hazard ratios for Catalonia versus the USA before and after the introduction of screening. The hazard ratios were then multiplied by the age- and stage-specific breast cancer hazard rates from the USA to obtain the Catalan hazard rates. We also compared breast cancer survival in Catalonia and the USA in two time periods, before cancer control interventions (USA 1975–79, Catalonia 1980–89) and after (USA and Catalonia 1990–2001). Survival in Catalonia in the 1980–89 period was worse than in the USA during 1975–79, but the differences disappeared in 1990–2001.</p> <p>Conclusion</p> <p>Our results suggest that access to better treatments and quality of care contributed to large improvements in survival in Catalonia. On the other hand, we obtained detailed breast cancer survival functions that will be used for modeling the effect of screening and adjuvant treatments in Catalonia.</p

Temporal and Individual Variation in Offspring Provisioning by Tree Swallows: A New Method of Automated Nest Attendance Monitoring

Studies of the ecology and evolution of avian nesting behavior have been limited by the difficulty and expense of sampling nest attendance behavior across entire days or throughout a substantial portion of the nestling period. Direct observation of nesting birds using human observers and most automated devices requires sub-sampling of the nestling period, which does not allow for the quantification of the duration of chick-feeding by parents within a day, and may also inadequately capture temporal variation in the rate at which chicks are fed. Here I describe an inexpensive device, the Automated Perch Recorder (APR) system, which collects accurate, long-term data on hourly rates of nest visitation, the duration of a pair's workday, and the total number of visits the pair makes to their nest across the entire period for which it is deployed. I also describe methods for verifying the accuracy of the system in the field, and several examples of how these data can be used to explore the causes of variation in and tradeoffs between the rate at which birds feed their chicks and the total length of time birds spend feeding chicks in a day

The Grizzly, February 11, 1991

Fraternity Pledging Returns Again • Wachtel Explains the Poverty of Affluence • The Changing War • Peer Educators and Community Service • Alumni Visit the Ballet • Study Abroad Memorable • A Valentine History • Side Winders • Dance Marathon • Get Shorty • Triumph of the Spirit • Gymnasts Fare Well at Ithaca, Reach Team Goal • Track Women Place Third at PAIAW Championships • Hoopsters Rounding Out Season • Fro Scores Point, Swimmers Wash Out Widener • Wrestlers Excel • Letters: Bring Becker Back; Praise From Florida; Oh no, Mr. Bill!; Respect Yourself and Your Major • War: A Personal Experience on the Homefront • Who Wants the Persian Gulf War? • The Mephisto of Calculus • This Spill No Mistakehttps://digitalcommons.ursinus.edu/grizzlynews/1270/thumbnail.jp