Ventilatory Threshold Responses at Different Percentages of Body Weight on the Alter-G Anti-Gravity Treadmill: A Pilot Study

Santillo, N., Figueroa, M., Lasala, T., Manning, J., William Paterson University, Wayne NJ Purpose: The purpose of this study was to determine if changes occurred in the ventilatory threshold (VT) upon manipulation of body weight (BW) when comparing 80% to 100% of BW in healthy college aged individuals on the Alter-G® anti-gravity treadmill. Methods: A modified Bruce Protocol was used to measure oxygen consumption (VO2peak) on 10 subjects (5 males, 5 females) at 100%, and 80% of BW. Testing protocols were randomized with two weeks in between each test. VT was determined by the software algorithm in the MedGraphics Ultima Series (St. Paul, MN) open exchange spirometer. Results: Gender did not significantly affect relative VO2peak or VT at either percentage of BW. No significant differences were found with regards to VO2peak (ml×kg-1×min-1) or VT at 100%BW & 80% BW. Conclusion: Upon the unweighting of a subject on the Alter-G® anti-gravity treadmill, individuals are able to train at similar intensities at 80% and 100% of BW. Since the unweighting produced similar metabolic responses, one could suggest that those with orthopedic limitations, who are not fully weight bearing, can maintain their cardiovascular conditioning. This type of training may also be advantageous for athletes who wish to reduce musculoskeletal strain within their training

Food web transfer of plastics to an apex riverine predator

As a rapidly accelerating expression of global change, plastics now occur extensively in freshwater ecosystems, yet there is barely any evidence of their transfer through food webs. Following previous observations that plastics occur widely in their prey, we used a field study of free‐living Eurasian dippers (Cinclus cinclus ), to test the hypotheses that (1) plastics are transferred from prey to predators in rivers, (2) plastics contained in prey are transferred by adults to altricial offspring during provisioning and (3) plastic concentrations in faecal and regurgitated pellets from dippers increase with urbanization. Plastic occurred in 50% of regurgitates (n = 74) and 45% of faecal samples (n = 92) collected non‐invasively from adult and nestling dippers at 15 sites across South Wales (UK). Over 95% of particles were fibres, and concentrations in samples increased with urban land cover. Fourier transform infrared spectroscopy identified multiple polymers, including polyester, polypropylene, polyvinyl chloride and vinyl chloride copolymers. Although characterized by uncertainty, steady‐state models using energetic data along with plastic concentration in prey and excreta suggest that around 200 plastic particles are ingested daily by dippers, but also excreted at rates that suggest transitory throughput. As some of the first evidence revealing that plastic is now being transferred through freshwater food webs, and between adult passerines and their offspring, these data emphasize the need to appraise the potential ecotoxicological consequences of increasing plastic pollution

Unsteady low-Reynolds number flow control in different regimes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106476/1/AIAA2013-353.pd

Rennet paste from lambs fed a milk substitute supplemented with Lactobacillus acidophilus: effects on lipolysis in ovine cheese.

The present work was undertaken to evaluate the effects of Lactobacillus acidophilus supplementation of a milk substitute on the features of lamb rennet paste used for cheese making. Lipolysis in cheese manufactured with rennet paste from lambs receiving supplemented milk was also evaluated. Lambs were subjected to 3 different feeding regimens (mother suckling, MS; artificial rearing, AR; and artificial rearing with 7 log10 cfu/mL of Lb. acidophilus supplementation of the milk substitute, ARLb) and slaughtered at 20 and 40 d of age for each feeding treatment. Abomasa of the lambs were processed to rennet paste. Microbial loads, enzymatic activities (chymosin, pepsin, and lipases), and renneting characteristics of the lamb rennet paste were determined. Free fatty acids and conjugated linoleic acids were detected in cheese at 60 d of ripening. Addition of 7 log10 cfu/mL of Lb. acidophilus to the milk substitute was carried out successfully. Total recovery of viable cells was recorded in milk supplied daily to the lambs in the ARLb group. The ARLb rennet had greater amounts of lactobacilli than did the MS or AR rennet, irrespective of the slaughter age of the lambs, and the ARLb rennet had higher concentrations of lactococci when lambs were slaughtered at 40 d of age. Chymosin and lipase activities were also higher in ARLb rennet than in MS or AR rennet from lambs slaughtered at an older age. Milk supplementation of ARLb lambs resulted in improved coagulating ability of the rennet and enhanced cheese lipolysis after 60 d of ripening. A reduction of all free fatty acids was observed in all cheeses when passing from 20 to 40 d of slaughter of the lambs. Conjugated linoleic acids were more abundant in ARLb cheeses at both 20 and 40 d. Therefore, supplementation of the milk substitute with Lb. acidophilus improved the enzymatic features of rennet and the healthful and nutritional characteristics of it the ovine cheese. Moreover, the addition of lactobacilli to the milk substitute made it possible to increase the slaughter age of lambs without detrimental effects on rennet characteristics

A Parallel Monte-Carlo Tree Search-Based Metaheuristic For Optimal Fleet Composition Considering Vehicle Routing Using Branch & Bound

In this paper, a Monte-Carlo Tree Search (MCTS)-based metaheuristic is developed that guides a Branch & Bound (B&B) algorithm to find the globally optimal solution to the heterogeneous fleet composition problem while considering vehicle routing. Fleet Size and Mix Vehicle Routing Problem with Time Windows (FSMVRPTW). The metaheuristic and exact algorithms are implemented in a parallel hybrid optimization algorithm where the metaheuristic rapidly finds feasible solutions that provide candidate upper bounds for the B&B algorithm which runs simultaneously. The MCTS additionally provides a candidate fleet composition to initiate the B&B search. Experiments show that the proposed approach results in significant improvements in computation time and convergence to the optimal solution.Comment: Submitted to the IEEE Intelligent Vehicles Symposium 202

Comments on ‘output feedback adaptive command following and disturbance rejection for nonminimum phase uncertain dynamical systems’

We provide numerical examples and analysis to show that the adaptive controller given by Theorem 3.1 of Yucelen et al. 1 may fail to stabilize plants under the stated conditions. Copyright © 2011 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83465/1/1235_ftp.pd

Thyrotropin modulates low density lipoprotein binding activity in FRTL-5 thyroid cells.

Abstract FRTL-5 cells possess high affinity low density lipoprotein (LDL) receptors which bind, internalize, and degrade LDL. When FRTL-5 cells are deprived of thyrotropin (TSH) the binding of LDL increases more than 2-fold. Upon addition of TSH, at a concentration of 1 x 10(-10) M or greater, LDL binding decreases rapidly and within 24 h reaches the level which is typical of FRTL-5 cells chronically stimulated by TSH. The data available suggest that TSH-dependent down-regulation of LDL receptor activity is exerted through a reduction of the number of active LDL receptors, with no change in affinity. It is unlikely that the synthesis of LDL receptors is impaired, since LDL receptor messenger RNA is not decreased by TSH. The effect of the hormone on LDL receptor activity can be mimicked by 8-Br-cAMP and is completely abolished by the protein synthesis inhibitor cycloheximide but not by actinomycin D. TSH regulation of LDL receptor activity is lost in v-ras Ki-transformed FRTL-5 cells (Ki Mol) which also have lost TSH dependence for adenylate cyclase activation and growth. However, 8-Br-cAMP decreases LDL binding in Ki Mol FRTL-5 cells. The reduced availability of LDL receptor in TSH-stimulated FRTL-5 cells may be related to the increased membrane fluidity (Beguinot, F., Beguinot, L., Tramontano, D., Duilio, C., Formisano, S., Bifulco, M., Ambesi-Impiombato, F. S., and Aloj, S. M. (1987) J. Biol. Chem. 262, 1575-1582) or may reflect increased degradation of LDL receptors. We propose that a lower cholesterol uptake is needed in an actively proliferating cell population, to increase the production of isoprenoids whether it be for cholesterol biosynthesis or for the synthesis of other compounds requiring isoprenoid precursors

Adaptive Control Based on Retrospective Cost Optimization

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83558/1/AIAA-46741-507.pd

Proliferative and apoptotic pathways in the testis of quail coturnix coturnix during the seasonal reproductive cycle

The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β‐estradiol (E2) and androgens are higher during the reproductive period compared to the non‐reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2‐induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt‐1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non‐reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt‐1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad

Prevalence of obesity and obesity-associated muscle wasting in patients on peritoneal dialysis

Background and aims: A progressive decrease in muscle mass until full-blown sarcopenia may occur in patients on peritoneal dialysis (PD) and worsen their life quality and expectancy. Here we investigate the prevalence of obesity and obesity-associated muscle wasting in PD patients. Patients and methods: The study design was observational, cross sectional. Body composition was assessed with BIA and BIVA in 88 PD patients (53.4 ± 13.1 years; 67% male). Patients with obesity and/or with reduced muscle mass were identified using FMI and SM/BW cutoff values, respectively. Inflammatory status was assessed by measuring CRP and fibrinogen blood levels. Results: A total of 44.3% of the patients showed a reduced muscle mass (37.5% moderate and 6.8% severe). The prevalence of obesity was 6.1%, 81.8%, and 100% in patients with normal, moderately, and severely reduced muscle mass, respectively (p < 0.05). Of the total, 15.2% of the patients with normal muscle mass, 18.4% of those with moderately reduced muscle mass, and 66.7% of those with severely reduced muscle mass had diabetes. The prevalence of severe muscle mass loss was higher in those with diabetes than in those without diabetes (22.2% vs. 2.8%, p < 0.05). Patients with obesity-associated muscle wasting showed higher fibrinogen (613.9 ± 155.1 vs. 512.9 ± 159.5 mg/dL, p < 0.05) and CPR (1.4 ± 1.3 vs. 0.6 ± 0.8 mg/dL, p < 0.05) blood concentrations than those with normal body composition. Conclusion: Obesity and diabetes were strongly associated with muscle mass loss in our PD patients. It remains to be established whether prevention of obesity with nutritional interventions can halt the occurrence of muscle mass loss in patients on PD