In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Clinical use of doxorubicin is greatly limited by its severe cardiotoxic side effects. L-carnitine is a vitamin-like substance which has been successfully used in many cardiomyopathies, however, the intracellular mechanism(s) remain unclear. The objective of this study was set to evaluate the protective effect of L-carnitine on doxorubicin-induced cardiomyocyte apoptosis, and to explore its intracellular mechanism(s).', "Primary cultured neonatal rat cardiomyocytes were treated with doxorubicin (1 µM) with or without pretreatment with L-carnitine (1-30 mM). Lactate dehydrogenase assay, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, and flow cytometry measurement were used to assess cytotoxicity and apoptosis. Fluorescent probes 2',7'-dichlorofluorescein diacetate and chemiluminescence assay of superoxide production were used to detect the production of reactive oxygen species. Western blotting was used to evaluate the quantity of cleaved caspase-3, cytosol cytochrome c, and Bcl-x(L) expression.", "L-carnitine inhibited doxorubicin-induced reactive oxygen species generation and NADPH oxidase activation, reduced the quantity of cleaved caspase-3 and cytosol cytochrome c, and increased Bcl-x(L) expression, resulting in protecting cardiomyocytes from doxorubicin-induced apoptosis. In addition, L-carnitine was found to increase the prostacyclin (PGI(2)) generation in cardiomyocytes. The siRNA transfection for PGI(2) synthase significantly reduced L-carnitine-induced PGI(2) and L-carnitine's protective effect. Furthermore, blockade the potential PGI(2) receptors, including PGI(2) receptors (IP receptors), and peroxisome proliferator-activated receptors alpha and delta (PPARα and PPARδ), revealed that the siRNA-mediated blockage of PPARα considerably reduced the anti-apoptotic effect of L-carnitine.\Question: Does l-carnitine reduce doxorubicin-induced apoptosis through a prostacyclin-mediated pathway in neonatal rat cardiomyocytes?
These findings suggest that L-carnitine protects cardiomyocytes from doxorubicin-induced apoptosis in part through PGI(2) and PPARα-signaling pathways, which may potentially protect the heart from the severe toxicity of doxorubicin.

Context: Nicotinamide adenine dinucleotide (NAD(+)) and its phosphorylated form (NADP(+)) are key molecules in ubiquitous bioenergetic and cellular signaling pathways, regulating cellular metabolism and homeostasis. Thus, supplementation with NAD(+) and NADP(+) precursors emerged as a promising strategy to gain many and multifaceted health benefits. In this proof-of-concept study, we sought to investigate whether chronic nicotinamide riboside administration (an NAD(+) precursor) affects exercise performance.', 'Eighteen Wistar rats were equally divided in two groups that received either saline vehicle or nicotinamide riboside at a dose of 300\xa0mg/kg body weight/day for 21\xa0days via gavage. At the end of the 21-day administration protocol, both groups performed an incremental swimming performance test.', 'The nicotinamide riboside group showed a tendency towards worse physical performance by 35\xa0% compared to the control group at the final 10\xa0% load (94\u2009±\u200953\xa0s for the nicotinamide riboside group and 145\u2009±\u200959\xa0s for the control group; P\u2009=\u20090.071).\Question: Does the NAD ( + ) precursor nicotinamide riboside decrease exercise performance in rats?
Our results do not confirm the previously reported ergogenic effect of nicotinamide riboside. The potentially negative effect of nicotinamide riboside administration on physical performance may be attributed to the pleiotropic metabolic and redox properties of NAD(+) and NADP(+).

Context: Environmental and socio-demographic factors can influence the variation of the human sex ratio at birth (SRB = the ratio of males to males plus females). In particular, findings of seasonal, parental education, birth order, and maternal age effects on the SRB are not always in agreement, and a number of works report minimal variation.', 'Here, we investigated the seasonality of SRB in academic and non-academic mothers employed at the University of Vienna, and who gave birth between 1963 and 2000 (n = 1932 births).', 'All data were available from an anonymous employee database.', "Both groups, academic and non-academic mothers do not differ between their overall SRB. In academic mothers the SRB is significantly (P = 0.004) increased during the springtime and decreased during the summertime. Although in non-academic mothers the trend is comparable, it is far less pronounced and not significant (P = 0.345). When a multiple logistic model was applied to the data of academic mothers the only significant influencing factor on the SRB is the season, while birth order of children and mothers' age at childbirth has no effect. None of the three independent variables influence the SRB in non-academic mothers.", 'These findings suggest a more flexible SRB rate in academic mothers than in non-academics within the seasons.\Question: Do academic mothers have a pronounced seasonal variation in their offspring sex ratio?

We conclude that the significant seasonal variation of the SRB in academic women cannot be merely interpreted as an effect of socio-economic status but more likely as the interaction between socio-economic and environmental working conditions.