3,075 research outputs found

    Effect of Caffeine on Heart Rate and Calories Burned During Exercise

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    Four active collegiate level students were asked to participate in a 3 day study, conducted in a strict environment. These students were required to perform the same exact exercise each day at the same time upon waking on an empty stomach following a fasted sleep. All individuals performed the exercise at 7:00 AM. On day one, the participant was to perform the exercise with no caffeine consumption. The following day, the participant was to drink one cup of coffee and perform the required exercise. On the last day of the experiment, each participant drank two cups of coffee before the exercise was performed. The exercise was one mile of walking on a flat treadmill at a speed of 3.5mph. These individuals were wearing a Garmin fitness watch and the heart rate strap that was included in the packaging. Immediately following exercise, these individuals took note of both their heart rate and calories burned. The basis of this study is to show the effects of caffeine on calorie burn and heart rate fluctuation. Following this study, it is important to note that all four participants showed a slight increase in both calories burned and heart rate following the required exercise on each day. The average calories burned with no caffeine was 109.25 and a heart rate of 103 beats per minute. When one cup of coffee was consumed by each individual, the average readings were 118.5 calories burned and a heart rate of 110.25 beats per minute. On the third and final day, the averages were 123.75 calories burned and a heart rate of 120 beats per minute. Thus, proving that caffeine consumption before exercise can help increase heart rate and in return burn more calories. This information can be especially helpful to all individuals trying to lose weight

    Repotenciación de alimentadores primarios para la reducción de pérdidas

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    Una manera efectiva de reducir las pérdidas de energía es a través de la repotenciación del conductor de los alimentadores primarios, que consiste en el aumento del calibre del conductor de la línea. El costo del conductor que se va a instalar, sumado con el costo de la mano de obra requerida para la instalación, debe ser compensado por el beneficio producido con la disminución del costo asociado a las pérdidas de energía. Este artículo desarrolla una metodología con la que se encuentra una propuesta de nueva configuración de calibres del conductor para cada segmento de los alimentadores del sistema, de tal manera que se minimicen los costos totales

    Repotenciación de alimentadores primarios para la reducción de pérdidas

    Get PDF
    Una manera efectiva de reducir las pérdidas de energía es a través de la repotenciación del conductor de los alimentadores primarios, que consiste en el aumento del calibre del conductor de la línea. El costo del conductor que se va a instalar, sumado con el costo de la mano de obra requerida para la instalación, debe ser compensado por el beneficio producido con la disminución del costo asociado a las pérdidas de energía. Este artículo desarrolla una metodología con la que se encuentra una propuesta de nueva configuración de calibres del conductor para cada segmento de los alimentadores del sistema, de tal manera que se minimicen los costos totales

    Cardiovascular Effects in Childhood Cancer Survivors Treated with Anthracyclines

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    Anthracyclines are commonly used to treat childhood leukemias and lymphomas, as well as other malignancies, leading to a growing population of long-term childhood cancer survivors. However, their use is limited by cardiotoxicity, increasing survivors' vulnerability to treatment-related complications that can markedly affect their quality of life. Survivors are more likely to suffer from heart failure, coronary artery disease, and cerebrovascular accidents compared to the general population. The specific mechanisms of anthracycline cardiotoxicity are complex and remain unclear. Hence, determining the factors that may increase susceptibility to cardiotoxicity is of great importance, as is monitoring patients during and after treatment. Additionally, treatment and prevention options, such as limiting cumulative dosage, liposomal anthracyclines, and dexrazoxane, continue to be explored. Here, we review the cardiovascular complications associated with the use of anthracyclines in treating malignancies in children and discuss methods for preventing, screening, and treating such complications in childhood cancer survivors

    Reinforcing and neurochemical effects of cannabinoid CB1 receptor agonists, but not cocaine, are altered by an adenosine A2A receptor antagonist

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    Several recent studies suggest functional and molecular interactions between striatal adenosine A2A and cannabinoid CB1 receptors. Here, we demonstrate that A2A receptors selectively modulate reinforcing effects of cannabinoids. We studied effects of A2A receptor blockade on the reinforcing effects of delta‐9‐tetrahydrocannabinol (THC) and the endogenous CB1 receptor ligand anandamide under a fixed‐ratio schedule of intravenous drug injection in squirrel monkeys. A low dose of the selective adenosine A2A receptor antagonist MSX‐3 (1 mg/kg) caused downward shifts of THC and anandamide dose‐response curves. In contrast, a higher dose of MSX‐3 (3 mg/kg) shifted THC and anandamide dose‐response curves to the left. MSX‐3 did not modify cocaine or food pellet self‐administration. Also, MSX‐3 neither promoted reinstatement of extinguished drug‐seeking behavior nor altered reinstatement of drug‐seeking behavior by non‐contingent priming injections of THC. Finally, using in vivo microdialysis in freely‐moving rats, a behaviorally active dose of MSX‐3 significantly counteracted THC‐induced, but not cocaine‐induced, increases in extracellular dopamine levels in the nucleus accumbens shell. The significant and selective results obtained with the lower dose of MSX‐3 suggest that adenosine A2A antagonists acting preferentially at presynaptic A2A receptors might selectively reduce reinforcing effects of cannabinoids that lead to their abuse. However, the appearance of potentiating rather than suppressing effects on cannabinoid reinforcement at the higher dose of MSX‐3 would likely preclude the use of such a compound as a medication for cannabis abuse. Adenosine A2A antagonists with more selectivity for presynaptic versus postsynaptic receptors could be potential medications for treatment of cannabis abuse

    Metalloprotease OMA1 Fine-tunes Mitochondrial Bioenergetic Function and Respiratory Supercomplex Stability

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    Mitochondria are involved in key cellular functions including energy production, metabolic homeostasis, and apoptosis. Normal mitochondrial function is preserved by several interrelated mechanisms. One mechanism – intramitochondrial quality control (IMQC) – is represented by conserved proteases distributed across mitochondrial compartments. Many aspects and physiological roles of IMQC components remain unclear. Here, we show that the IMQC protease Oma1 is required for the stability of the respiratory supercomplexes and thus balanced and tunable bioenergetic function. Loss of Oma1 activity leads to a specific destabilization of respiratory supercomplexes and consequently to unbalanced respiration and progressive respiratory decline in yeast. Similarly, experiments in cultured Oma1-deficient mouse embryonic fibroblasts link together impeded supercomplex stability and inability to maintain proper respiration under conditions that require maximal bioenergetic output. Finally, transient knockdown of OMA1 in zebrafish leads to impeded bioenergetics and morphological defects of the heart and eyes. Together, our biochemical and genetic studies in yeast, zebrafish and mammalian cells identify a novel and conserved physiological role for Oma1 protease in fine-tuning of respiratory function. We suggest that this unexpected physiological role is important for cellular bioenergetic plasticity and may contribute to Oma1- associated disease phenotypes in humans

    Identification of sVSG117 as an immunodiagnostic antigen and evaluation of a dual-antigen lateral flow test for the diagnosis of human african trypanosomiasis

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    The diagnosis of human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense relies mainly on the Card Agglutination Test for Trypanosomiasis (CATT). There is no immunodiagnostic for HAT caused by T. b. rhodesiense. Our principle aim was to develop a prototype lateral flow test that might be an improvement on CATT.Pools of infection and control sera were screened against four different soluble form variant surface glycoproteins (sVSGs) by ELISA and one, sVSG117, showed particularly strong immunoreactivity to pooled infection sera. Using individual sera, sVSG117 was shown to be able to discriminate between T. b. gambiense infection and control sera by both ELISA and lateral flow test. The sVSG117 antigen was subsequently used with a previously described recombinant diagnostic antigen, rISG65, to create a dual-antigen lateral flow test prototype. The latter was used blind in a virtual field trial of 431 randomized infection and control sera from the WHO HAT Specimen Biobank.In the virtual field trial, using two positive antigen bands as the criterion for infection, the sVSG117 and rISG65 dual-antigen lateral flow test prototype showed a sensitivity of 97.3% (95% CI: 93.3 to 99.2) and a specificity of 83.3% (95% CI: 76.4 to 88.9) for the detection of T. b. gambiense infections. The device was not as good for detecting T. b. rhodesiense infections using two positive antigen bands as the criterion for infection, with a sensitivity of 58.9% (95% CI: 44.9 to 71.9) and specificity of 97.3% (95% CI: 90.7 to 99.7). However, using one or both positive antigen band(s) as the criterion for T. b. rhodesiense infection improved the sensitivity to 83.9% (95% CI: 71.7 to 92.4) with a specificity of 85.3% (95% CI: 75.3 to 92.4). These results encourage further development of the dual-antigen device for clinical use
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