The Effects of Fitness Level and Sex on EPOC Following High Intensity Interval and Moderate Intensity Aerobic Exercise

In the past few years, much attention has been directed toward shorter-duration vigorous intensity aerobic exercise as opposed to longer-duration moderate intensity exercise. There is conflicting evidence as to whether vigorous exercise can result in a greater excess post-exercise oxygen consumption (EPOC) and thus more calories burned when compared to moderate continuous exercise performed for a longer duration. In addition, the literature contains a dearth of information isolating and investigating male and female response to these exercises, as well as fit and unfit subjects. The purpose of this study was to quantify EPOC following moderate intensity aerobic exercise (MOD) and high intensity aerobic intervals (HIAI) of equal energy expenditure. It was hypothesized that (1) EPOC following HIAI would be greater than following MOD, (2) EPOC of males and females would not differ, and (3) more fit subjects would have less of an increase in EPOC from MOD to HIAI than less fit subjects, predicted as a negative correlation between subjects’ VO2max and delta EPOC. Eleven subjects (5 male, 6 female; age 25.1 + 2.0 yr; height 169 + 3 cm; mass 67.6 + 3.0 kg; VO2max 41.0 + 1.9 mL.min-1.kg-1) participated in MOD and HIAI trials in a counterbalanced order separated by at least 48 hours. HIAI was ten 1-min intervals at 90% maximal aerobic power (Pmax), alternated with 1-min intervals at 60% Pmax. MOD was 30 min at 50% Pmax. Warm-ups and cool-downs were also matched for total work. All exercise was performed on a cycle ergometer. Data are reported as mean + SE. VO2 at rest was 4.0 + 0.3 mL·min-1·kg-1 preceding the MOD trial, and 4.1 + 0.4 mL·min-1·kg-1 for HIAI. Net VO2 during exercise (inclusive of warm-ups and cool-downs) was 52.7 + 3.6 L MOD, and 52.0 + 3.9 L HIAI. There was a weak trend (p = 0.164) for EPOC over 41 min of recovery to be greater in the HIAI trial (3.02 + 0.48 L) than the MOD trial (1.98 + 0.56 L). EPOC during minutes 0-10 post-exercise was significantly greater (p = 0.009) following HIAI (2.28 + 0.32 L) than MOD (1.37 + 0.43 L). Following a one-min water break, EPOC during minutes 11-41 post-exercise was 0.74 + 0.28 L HIAI, and 0.56 + 0.43 L MOD, which were statistically similar (p = 0.807). For EPOC expressed relative to body mass, males had a significantly greater (p = 0.035) EPOC over the entire 41-min recovery period than females (HIAI males: 58.0 + 8.7, females: 32.5 + 4.9 mL∙kg-1; MOD males: 44.9 + 14.0, females: 18.7 + 10.6 mL∙kg-1). For the separate time periods of 0-10 min and 11-41 min, there were trends for males to have higher EPOC than females (p = 0.086 and 0.053, respectively). When total EPOC was corrected for fat free mass there was no significant difference between male and female responses to either condition (p = 0.162).There was no correlation between VO2max and absolute ∆EPOC (L), whether using the total time frame (0-41 min, p = 0.958), or the early (0-10 min, p = 0.958) or late (11-41 min, p = 0.281) phases of EPOC. In conclusion, EPOC consisted of only 3.7% of the net oxygen consumption during the MOD exercise trial, and only 5.8% of the net oxygen consumption during the HIAI trial. While the HIAI EPOC was significantly greater than the MOD EPOC, neither EPOC contributes substantially to the overall energy cost of the exercise, and is thus unlikely to have significant effects on weight loss or other health outcomes. When prescribing exercise to those who are less fit or are new to exercising, it is important to consider the intensity and time that is most tolerable when the primary goal is weight loss

Freshwater Phytoplankton Populations Detected Using High Pressure Liquid Chromatography (HPLC) of Taxon-Specific Pigments

Phytoplankton are key primary producers in aquatic ecosystems, and the principle food source for primary consumers. Individual phytoplankton species respond to different physical, chemical and biological parameters, so monitoring taxonomic composition of the phytoplankton community is a means to monitor changes in environmental conditions. Phytoplankton community changes have frequently been monitored by estimating biomass (using chlorophyll a, measured fluorometrically), and taxonomic data obtained from cell counts. While such methods are useful, they are time-consuming. I hypothesized that high pressure liquid chromatography (HPLC) methods, which have been frequently used in marine systems, would allow separation and identification of key pigments. These pigments could then be used to allocate chlorophyll a to particular taxa using an optimization algorithm (CHEMTAX), providing simultaneous biomass estimates and taxonomic information. The present study tested the applicability of HPLC/CHEMTAX methods in Lake Michigan phytoplankton communities. During Summer 2008, six synoptic cruises were conducted aboard the R/V Neeskay, sampling communities at nearshore and offshore sites and carrying out grazing and nutrient enrichment experiments. HPLC/CHEMTAX methods were compared with conventional methods over the seasonal cycle from June to August. Estimates of chlorophyll a biomass measured with the HPLC method agreed well with conventional fluorometric measurements of extracted pigments. Chlorophyll a reached maxima (averaging 5.0 μg L-1 nearshore and 1.5 μg L-1 offshore) in late June/early July, with the exception of the offshore metalimnion where chlorophyll a peaked (3.0 μg L-1) in late July. Nutrient enrichment experiments demonstrated that the algal communities were phosphorus-limited, while grazing experiments showed declines in phytoplankton biomass with increasing grazer abundance. Taxonomic groups were consistently misidentified by HPLC/CHEMTAX, relative to microscope methods; confusion between diatoms and chrysophytes was particularly serious. Specific improvement to the HPLC method that might help overcome the problems include faster sample processing techniques to prevent pigment degradation, eluting fewer critical pigments to improve resolution, and use of flow cytometric measurements in parallel. Although the HPLC method is faster and more efficient, it seems unlikely that microscopy to verify the specific taxa within the phytoplankton community can be avoided

Human to Mosquito Transmission of Dengue Viruses

The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic antivirals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquito's susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host

Life on the Quarry Wall Vs the Quarry Floor: Parthenocissus quinquefolia

Parthenocissus quinquefolia, Virginia creeper, is found in two parts of the DePauw Nature Park quarry: vertically along the quarry wall and on large rock piles on the quarry floor. I looked into how these different habitats influenced the growth form, stress responses, and fitness of the P. quinquefolia growing in them. P. quinquefolia on the wall has higher chlorophyll a content and higher water content. There was also a higher percentage of flowering individuals on the quarry wall than on the floor. Lastly, the two habitats had vastly different morphological growth forms, with those on the wall having very long internodes compared to those on the floor. The data shows that P. quinquefolia on the quarry floor was more water and light stressed and had lower fitness; this suggests the quarry wall is a more suitable habitat for P. quinquefolia than the floor

Stressed, but doing fine. An Investigation of Apocynum Canabinum Patches and Individuals

Apocynum cannabinum (hemp dogbane) is a native Indiana plant that is abundant in the DePauw University Nature Park’s quarry, a heterogeneous site that contains stretches of dry, rocky terrain in addition to many temporary ponds. In 2023, I mapped the distribution of A. cannabinum in the quarry to see if its habitats are associated with elevation and/or the presence of temporary ponds. I also conducted a study of diurnal pollinator visitation, and an examination of damage caused by the dogbane saucrobotys moth (Saucrobotys futilalis)

Assimilation and Transformation: Application of Digital Textile Printing

The goal of this project was to develop textile designs and implementing the design using digital textile printing in order to showcase a textile design collection based on time spent studying abroad in Italy. Designers such as Helmut Lang, Akris, and Dolce and Gabbana have featured the use of digitally printed textiles in their runway collections (Binkley, 2010)

Local Elected Officials’ Receptivity to Refugee Resettlement in the United States

Local leaders possess significant and growing authority over refugee resettlement, yet we know little about their attitudes toward refugees. In this article, we use a conjoint experiment to evaluate how the attributes of hypothetical refugee groups influence local policymaker receptivity toward refugee resettlement. We sample from a novel, national panel of current local elected officials, who represent a broad range of urban and rural communities across the United States. We find that many local officials favor refugee resettlement regardless of refugee attributes. However, officials are most receptive to refugees whom they perceive as a strong economic and social fit within their communities. Our study is the first in a growing literature on individual attitudes toward refugees to systematically examine the preferences of US local elected officials and offers unique insights into the views of this influential and policy-relevant group

Clinical utility of pressure feedback to socket design and fabrication

Background: The clinical utility of measuring pressure at the prosthetic socket-residual limb interface is currently unknown. Objectives: This study aimed to identify whether measuring interface pressure during prosthetic design and fabrication results in closer agreement in pressure measurements between sockets made by different clinicians, and a reduction in pressure over areas of concern. It also investigated whether clinicians value knowing the interface pressure during the fabrication process. Study design: Mixed methods. Methods: Three prosthetists designed a complete prosthetic system for a transtibial residual limb surrogate. Standardised mechanical testing was performed on each prosthetic system to gain pressure measurements at four key anatomical locations. These measurements were provided to the clinicians, who subsequently modified their sockets as each saw fit. The pressure at each location was re-measured. Each prosthetist completed a survey that evaluated the usefulness of knowing interface pressures during the fabrication process. Results: Feedback and subsequent socket modifications saw a reduction in the pressure measurements at three of the four anatomical locations. Furthermore, the pressure measurements between prosthetists converged. All three prosthetists found value in the pressure measurement system and felt they would use it clinically. Conclusions: Results suggest that sensors measuring pressure at the socket-limb interface has clinical utility in the context of informing prosthetic socket design and fabrication. If the technology is used at the check socket stage, iterative designs with repeated measurements can result in increased consistency between clinicians for the same residual limb, and reductions in the magnitudes of pressures over specific anatomical landmarks. Clinical relevance This study provides new information on the value of pressure feedback to the prosthetic socket design process. It shows that with feedback, socket modifications can result in reduced limb pressures, and more consistent pressure distributions between prosthetists. It also justifies the use of pressure feedback in informing clinical decisions

The location of international practices: what is human rights practice?

This article opens up space to challenge state-centrism about human rights practice. To do so, it presents and critically assesses four methods that can be used to determine who and/or what counts as a part of any international practice: the agreement method, which locates a practice by referring to speech acts that define it; the contextual method, which locates a practice by referring to the actions, meanings, and intentions of practitioners; the value method, which locates a practice by identifying a value or principle that the practice reflects or instantiates; and the purpose method, which locates a practice by constructing an account of the sociopolitical reason(s) for a practice's existence. The purpose method, based on an interpretation of Rawls' constructivism, is developed, in a way that focuses on practitioners' judgement-based reasons to assign responsibility for human rights to any state or non-state actor