110 research outputs found

    Impact of Menstrual Phases on Stress Markers: A Pilot Study

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    PURPOSE: Previous research has shown that different phases of the menstrual cycle may impact biometrics such as markers of stress and inflammation [e.g., cortisol (CORT), interleukin-6] as well as body composition. However, there is scarce literature regarding markers of stress and oxidative stress such as salivary a-amylase (sAA), immunoglobin-A (SIgA) and uric acid (UA), in relation to the four different menstrual phases. The purpose of this study was to examine the impact of menstrual phases on sAA, CORT, UA and SIgA. METHODS: 21 pre-menopausal women with regular menstrual cycles (n=9) oral contraceptive users (OC) and (n=12) non-oral contraceptive users (non-OC) recorded baseline cycle dates using the Flo Period Tracker appä. Participants began experimental testing after recording baseline dates, consisting of four total sessions with one session occurring during the 1) menses, 2) late follicular, 3) ovulatory and 4) late luteal phase. Salivary markers: CORT, sAA, UA, and SIgA, along with diastolic and systolic blood pressure (BP), total body water (TBW) and body fat percentage (BF%) were recorded during each phase. BF% and TBW were determined via InBody bioelectric-impedance analyzerä. 500uL of saliva was collected, with samples immediately frozen at -80°C until analysis. Saliva samples were centrifuged at 4°C for a duration of 15 minutes at 1500g prior to analysis and duplicated for CORT, sAA, UA and SIgA concentrations. Statistical procedures were conducted via SAS v 9.4 (Cary, NC). One way repeated measures analysis of variance was used to evaluate outcome measures as well as changes in salivary markers and body composition measurements across different menstrual cycle phases. Fisher’s Least Significant Difference test was used to compare means in the instance of a significant main effect (p \u3c 0.05). Partial eta squared (hp2) was run to determine effect size. RESULTS: sAA concentrations were significantly lower during the follicular phase compared menstruation phase (p = 0.006, ηp2 = 0.14). The main effect for SIgA approached significance (p = 0.05). There were no changes in CORT, UA, BF%, TBW or diastolic and systolic blood pressure. CONCLUSION: These findings suggest the menstrual cycle influences sAA concentrations in both OC users and non-OC users. More research needs to be conducted with a larger sample size in order to determine significance of SIgA in relation to menstrual phases

    Caffeinated Gum Does Not Influence RPE-Regulated Cadence in Recreationally-Active, College Females Regardless of Habitual Caffeine Consumption

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    International Journal of Exercise Science 14(2): 1375-1387, 2021. Caffeine (CAF) has been extensively studied for its ergogenic and analgesic effects during exercise. However, the majority of these studies have been conducted in male populations. This study investigated the effects of acute CAF chewing gum on self-selected exercise intensity during a rating of perceived exertion (RPE) production trial in active females (n = 16, 21.0 ± 2.8 y). Data were also analyzed based on habitual CAF consumption level. Participants completed a V̇O2peak trial, followed by a familiarization and two randomized, triple-blinded experimental RPE production trials on an arm ergometer [clamped resistance, blinded to self-selected cadence (CAD)] with either CAF gum (300 mg; 4.8 ± 0.7 mg/kg-1 body mass) or placebo (PLA), at a prescribed RPE of 4 and 7 (10 min each). Self-selected CAD did not statistically differ (p \u3e 0.05) between CAF or PLA for an RPE4 (37.7 ± 1.6 vs. 37.6 ± 1.6 rev·min-1) or RPE7 (42.9 ± 1.6 vs. 41.2 ± 1.7 rev·min-1), respectively. There were no statistical differences between treatment groups for any other variables, except restlessness rating which was significantly higher (3.5 vs. 2.2; p = 0.03, d = 0.64) for the CAF group compared to PLA. Secondary analysis revealed no statistical differences for any variables between habitual consumers of low (23 ± 20 mg/day) or mod/high (195 ± 93 mg/day) CAF. Our data support previous studies examining CAF in women across different testing modalities and suggest that regardless of habitual CAF consumption, females might require higher doses of CAF to replicate subjective and physiological responses commonly observed using similar RPE production protocols in male participants. These findings support the need for additional investigations into female physiological and perceptual responses following CAF ingestion

    A Three-Dimensional Finite Element IVIethod for Large Elastic Deformations of Ventricular Myocardium: II-Prolate Spheroidal Coordinates^

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    Introduction The finite element (FE) method is perhaps the most promising approach for numerical stress analysis in the heart. We previously described a three-dimensional (3D) FE method for large elastic deformations of nonlinear, anisotropic soft tissues with several features developed specifically for cardiac mechanics applications [I]. Although the governing equations were derived using general curvilinear coordinates, that paper was restricted to cylindrical and spherical polar coordinate formulations, for which analytic solutions were available for validation. This paper is focused on prolate spheroidal coordinates, which have become a standard geometric framework for clinical The computational advantages of a prolate spheroidal description of the heart have been demonstrated by Nielsen and coworker

    International society of sports nutrition position stand: tactical athlete nutrition

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    This position stand aims to provide an evidence-based summary of the energy and nutritional demands of tactical athletes to promote optimal health and performance while keeping in mind the unique challenges faced due to work schedules, job demands, and austere environments. After a critical analysis of the literature, the following nutritional guidelines represent the position of the International Society of Sports Nutrition (ISSN)

    Ceacam1 separates graft-versus-host-disease from graft-versus-tumor activity after experimental allogeneic bone marrow transplantation.

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    BACKGROUND: Allogeneic bone marrow transplantation (allo-BMT) is a potentially curative therapy for a variety of hematologic diseases, but benefits, including graft-versus-tumor (GVT) activity are limited by graft-versus-host-disease (GVHD). Carcinoembryonic antigen related cell adhesion molecule 1 (Ceacam1) is a transmembrane glycoprotein found on epithelium, T cells, and many tumors. It regulates a variety of physiologic and pathological processes such as tumor biology, leukocyte activation, and energy homeostasis. Previous studies suggest that Ceacam1 negatively regulates inflammation in inflammatory bowel disease models. METHODS: We studied Ceacam1 as a regulator of GVHD and GVT after allogeneic bone marrow transplantation (allo-BMT) in mouse models. In vivo, Ceacam1(-/-) T cells caused increased GVHD mortality and GVHD of the colon, and greater numbers of donor T cells were positive for activation markers (CD25(hi), CD62L(lo)). Additionally, Ceacam1(-/-) CD8 T cells had greater expression of the gut-trafficking integrin α(4)β(7), though both CD4 and CD8 T cells were found increased numbers in the gut post-transplant. Ceacam1(-/-) recipients also experienced increased GVHD mortality and GVHD of the colon, and alloreactive T cells displayed increased activation. Additionally, Ceacam1(-/-) mice had increased mortality and decreased numbers of regenerating small intestinal crypts upon radiation exposure. Conversely, Ceacam1-overexpressing T cells caused attenuated target-organ and systemic GVHD, which correlated with decreased donor T cell numbers in target tissues, and mortality. Finally, graft-versus-tumor survival in a Ceacam1(+) lymphoma model was improved in animals receiving Ceacam1(-/-) vs. control T cells. CONCLUSIONS: We conclude that Ceacam1 regulates T cell activation, GVHD target organ damage, and numbers of donor T cells in lymphoid organs and GVHD target tissues. In recipients of allo-BMT, Ceacam1 may also regulate tissue radiosensitivity. Because of its expression on both the donor graft and host tissues, this suggests that targeting Ceacam1 may represent a potent strategy for the regulation of GVHD and GVT after allogeneic transplantation

    Tension-Compression Loading with Chemical Stimulation Results in Additive Increases to Functional Properties of Anatomic Meniscal Constructs

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    Objective: This study aimed to improve the functional properties of anatomically-shaped meniscus constructs through simultaneous tension and compression mechanical stimulation in conjunction with chemical stimulation. Methods: Scaffoldless meniscal constructs were subjected to simultaneous tension and compressive stimulation and chemical stimulation. The temporal aspect of mechanical loadingwas studied by employing two separate five day stimulation periods. Chemical stimulation consisted of the application of a catabolic GAG-depleting enzyme, chondroitinase ABC (C-ABC), and an anabolic growth factor, TGF-b1. Mechanical and chemical stimulation combinations were studied through a full-factorial experimental design and assessed for histological, biochemical, and biomechanical properties following 4 wks of culture. Results: Mechanical loading applied from days 10–14 resulted in significant increases in compressive, tensile, and biochemical properties of meniscal constructs. When mechanical and chemical stimuliwere combined significant additive increases in collagen per wet weight (4-fold), compressive instantaneous (3-fold) and relaxation (2-fold) moduli, and tensile moduli in the circumferential (4-fold) and radial (6-fold) directions were obtained. Conclusions: This study demonstrates that a stimulation regimen of simultaneous tension and compression mechanical stimulation, C-ABC, and TGF-b1 is able to create anatomic meniscus constructs replicating the compressive mechanica

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

    Energy Levels of Light Nuclei. III

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