508 research outputs found
Spinoza on conatus, inertia and the impossibility of self-destruction
Suicide or self-destruction means in ordinary language “the act of killing oneself deliberately” (intentionally or on purpose). Indeed, that’s what we read in the Oxford dictionary and the Oxford dictionary of philosophy , which seems to be confirmed by the etymology of the term “suicide”, a term introduced around mid-17th century deduced from the modern Latin suicidium, ‘act of suicide’.
Traditionally, suicide was regarded as immoral, irreligious and illegal in Western culture. However, during the 17th century this Christian view started to change as a consequence of the rise of modern science . Generally speaking, Spinoza does not write much on death. His name does even not occur in the Oxford Philosophy of Death, although he had had very particular ideas on the nature of death. However, he even had much more particular ideas on suicide. Moreover, he states in the fourth proposition of the third part of his masterpiece, the Ethics, that self-destruction is simply impossible: Nulla res, nisi à causâ externâ, potest destrui
Diagnosing overtraining in athletes using the two-bout exercise protocol
Objective: In this work, whether a two-bout exercise protocol can be used to make an objective, immediately available distinction between non-functional over reaching (NFO) and overtraining syndrome (OTS) was studied. Design: Underperforming athletes who were diagnosed with the suspicion of NFO or OTS were included in the study. Recovery of the athletes was monitored by a sports physician to retrospectively distinguish NFO from OTS. Setting: Sports medicine laboratory Participants: The protocol was started and completed by 10 underperforming athletes. NFO was retrospectively diagnosed in five athletes, and OTS was diagnosed in five athletes. Interventions: A two-bout maximal exercise protocol was used to measure physical performance and stressinduced hormonal reactions. Main outcome measurements: Exercise duration, heart rate and blood lactate concentration were measured at the end of both exercise tests. Venous concentrations cortisol, adrenocorticotrophic hormone (ACTH), prolactin and growth hormone were measured both before and after both exercise tests. Results: Maximal blood lactate concentration was lower in OTS compared with NFO, while resting concentrations of cortisol, ACTH and prolactin concentrations were higher. However, sensitivity of these measures was low. The ACTH and prolactin reactions to the second exercise bout were much higher in NFO athletes compared with OTS and showed the highest sensitivity for making the distinction. Conclusions: NFO might be distinguished from OTS based on ACTH and prolactin reactions to a two-bout exercise protocol. This protocol could be a useful tool for diagnosing NFO and OTS; however, more data should be collected before this test can be used as the gold standard
The effects of acute dopamine reuptake inhibition on performance
Introduction: Acute bupropion (BUP; dopamine/noradrenaline reuptake inhibitor)
administration significantly improved time trial performance and increased core
temperature in the heat (30°C). Purpose: The present study was performed to examine
the effect of a dopaminergic reuptake inhibitor on exercise capacity and
thermoregulation during prolonged exercise in temperate and warm conditons.
Methods: Eight healthy well-trained male cyclists participated in this study. Subjects
ingested either a placebo (PLAC; lactose; 20mg) or Ritalin (RIT; methylphenidate
(MPH); 20mg) one hour before the start of exercise in temperate (18°C) or warm (30°C)
conditions and cycled for 60 min at 55% Wmax, immediately followed by a time trial
(TT; pla18 and rit18; pla30 and rit30) to measure exercise performance. Results: Ritalin
did not influence TT performance at 18oC (P=0.397). TT was completed 16% faster in
rit30 (38.1±6.4min) than in pla30 (45.4±7.3min; p=0.049). Power output was higher in
rit30, compared to pla30 (p<0.05). In the heat Tcore was significantly higher at rest
(p=0.009), at the start of exercise and throughout rit30 (p<0.05). Throughout rit30 heart
rates were significantly higher (p<0.05). Prolactin concentrations decreased after one
hour cycling in 18°C (p=0,036) and at rest in 30°C (p=0,007) after RIT administration.
Conclusions: These results show that RIT has a clear ergogenic effect that was not
apparent in 18°C. The combination of a dopamine reuptake inhibitor and exercise in the
heat clearly improved performance and appeared to increase metabolic heat production,
suggesting an important role for dopamine in the fatigue process
Requirement of RIZ1 for cancer prevention by methyl-balanced diet
The typical Western diet is not balanced in methyl nutrients that regulate the level of the methyl donor S-adenosylmethionine (SAM) and its derivative metabolite S-adenosylhomocysteine (SAH), which in turn may control the activity of certain methyltransferases. Feeding rodents with amino acid defined and methyl-imbalanced diet decreases hepatic SAM and causes liver cancers. RIZ1 (PRDM2 or KMT8) is a tumor suppressor and functions in transcriptional repression by methylating histone H3 lysine 9. Here we show that a methyl-balanced diet conferred additional survival benefits compared to a tumor-inducing methyl-imbalanced diet only in mice with wild type RIZ1 but not in mice deficient in RIZ1. While absence of RIZ1 was tumorigenic in mice fed the balanced diet, its presence did not prevent tumor formation in mice fed the imbalanced diet. Unlike most of its related enzymes, RIZ1 was upregulated by methyl-balanced diet. Methyl-balanced diet did not fully repress oncogenes such as c-Jun in the absence of RIZ1. The data identify RIZ1 as a critical target of methyl-balanced diet in cancer prevention. The molecular understanding of dietary carcinogenesis may help people make informed choices on diet, which may greatly reduce the incidence of cancer
Surrogate markers and survival in women receiving first-line combination anthracycline chemotherapy for advanced breast cancer
Surrogate markers may help predict the effects of first-line treatment on survival. This metaregression analysis examines the relationship between several surrogate markers and survival in women with advanced breast cancer after receiving first-line combination anthracycline chemotherapy 5-fluorouracil, adriamycin and cyclophosphamide (FAC) or 5-fluorouracil, epirubicin and cyclophosphamide (FEC) . From a systematic literature review, we identified 42 randomised trials. The surrogate markers were complete or partial tumour response, progressive disease and time to progression. The treatment effect on survival was quantified by the hazard ratio. The treatment effect on each surrogate marker was quantified by the odds ratio (or ratio of median time to progression). The relationship between survival and each surrogate marker was assessed by a weighted linear regression of the hazard ratio against the odds ratio. There was a significant linear association between survival and complete or partial tumour response (P<0.001, R2=34%), complete tumour response (P=0.02, R2=12%), progressive disease (P<0.001, R2=38%) and time to progression (P<0.0001, R2=56%); R2 is the proportion of the variability in the treatment effect on survival that is explained by the treatment effect on the surrogate marker. Time to progression may be a useful surrogate marker for predicting survival in women receiving first-line anthracycline chemotherapy and could be used to estimate the survival benefit in future trials of first-line chemotherapy compared to FAC or FEC. The other markers, tumour response and progressive disease, were less good
Fermentation of Arabinoxylan-Oligosaccharides, Oligofructose and their Monomeric Sugars by Hindgut Bacteria from Siberian Sturgeon and African Catfish in Batch Culture in vitro
The in vitro fermentation of two Non-Digestible Oligosaccharide (NDO) preparations, Arabinoxylan- Oligosaccharides (AXOS) and Oligofructose (OF), and their respective monomeric sugars, xylose and fructose, were investigated by hindgut microbiota of two major aquaculture fish species, Siberian sturgeon (Acipenser baerii) and African catfish (Clarias gariepinus). Inocula from the hindgut of both fish species were incubated for 48 h in bottles containing 1.0% of one of four substrates, i.e. AXOS, OF, xylose or fructose. Amounts and profiles of produced Short-Chain Fatty Acids (SCFAs) differed between the two fish species and substrates. The hindgut microbiota of Siberian sturgeon has a higher fermentation capacity than the microbiota from African catfish. Xylose was much easier fermented than AXOS by microbiota from Siberian sturgeon whereas OF was quicker fermented than fructose with African catfish inoculum. The SCFAs were dominated by acetic acid for both fish species and for all substrates. Fermentation of OF and fructose by hindgut microbiota of Siberian sturgeon also yielded high amounts of butyric and branched-chain fatty acids after 48 h incubation. Results of this study suggest that AXOS, OF, and their monomeric sugars have an impact on microbial fermentation activity of hindgut microbiota from Siberian sturgeon and African catfish in a substrate and species dependent manner
Lysolecithin, but not lecithin, improves nutrient digestibility and growth rates in young broilers
Young broilers have an underdeveloped ability for lipid digestion. The potential of lecithin and lysolecithin to improve lipid digestion and growth performance was investigated in 3 experiments: an in vitro model that mimics the intestinal conditions of the chick, a digestibility trial with chicks (5 to 7 days of age), and a performance trial until 21 days of age. In Experiment 1, palm oil (PO), palm oil with lecithin (PO+L), and palm oil with lysolecithin (PO+LY) were subjected to in vitro hydrolysis and applied to Caco-2 monolayers to assess lipid absorption. The in vitro hydrolysis rate of triglycerides was higher in PO+LY (k= 11.76 × 10-3 min-1) than in either PO (k= 9.73 × 10 3 min 1) or PO+L (k= 8.41 × 10 3 min 1), and the absorption of monoglycerides and free fatty acids was highest and free fatty acids was highest (P<0.01) for PO+LY. In Experiment 2, 90 broilers were assigned to three dietary treatments: a basal diet with 4% palm oil, and the basal diet supplemented with either 250 ppm lecithin or lysolecithin. ATTD of crude fat was higher in broilers supplemented with lysolecithin, but was lower in broilers supplemented with lecithin. DM digestibility and AMEn in birds supplemented with lysolecithin were significantly higher (3.03% and 0.47 MJ/kg, respectively). In Experiment 3, 480 broilers were randomly allocated to four dietary treatments: basal diet with soybean oil (2%), basal diet with lecithin (2%), soybean oil diet with 250 ppm lysolecithin, or lecithin oil diet with 250 ppm lysolecithin. Lecithin diets significantly reduced weight at day 10 and 21 compared with soybean oil. However, the addition of lysolecithin to lecithin-containing diets significantly improved bird performance. The results of these studies show that, in contrast to lecithin, lysolecithin is able to significantly improve the digestibility and energy values of feed in young broilers
Esophageal cancer in a young woman with bulimia nervosa: a case report
Adenocarcinoma of the esophagus has increased dramatically within the United States and continues to have a poor prognosis despite aggressive treatment. Identifying potential risk factors is critical for the early detection and treatment of this disease. The present case report describes a very young woman who developed adenocarcinoma of the esophagus after only a brief history of bulimia. These findings suggest that even in very young patients, bulimia may represent a risk factor for adenocarcinoma of the esophagus
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