Solvation oscillations and excited-state dynamics of 2-amino- and 2-hydroxy-7-nitrofluorene and its 2'-deoxyriboside

Push-pull substituted fluorenes are considered for use as dynamic solvation probes in polynucleotides. Their fluorescence band is predicted (by simulations) to show weak spectral oscillations on the subpicosecond time scale depending on the nucleotide sequence. The oscillations reflect the local far-infrared spectrum of the environment around the probe molecule. A connection is provided by the continuum theory of polar solvation which, however, neglects molecular aspects. We examine the latter using acetonitrile solution as a test case. A collective librational solvent mode at 100 cm-1 is observed with 2-amino-7-nitrofluorene, 2-dimethylamino-7-nitrofluorene, 2-hydroxy-7-nitrofluorene, and its 2'-deoxyriboside. Different strengths of the oscillation indicate that rotational friction of nearby acetonitrile molecules depends on the solute structure or that H bonding is involved in launching the librational coherence. Polar solvation in methanol is used for comparison. With hydroxynitrofluorenes, the observation window is limited by intersystem crossing for which rates are reported. A prominent excited-state absorption band of nitrofluorenes at 430 nm can be used to monitor polar solvation. Structural and electronic relaxation pathways are discussed with the help of quantum chemical calculations

Changes in rural children’s use of time: evidence from Ethiopia and Andhra Pradesh, India

In recent decades, children’s time has become a global commodity, fought over by a range of national and international policymakers (Stephens 1995). Ambitious global social policies construct particular visions of childhood and, in doing so, shape how children spend their time. The Millennium Development Goals, the Education For All Dakar Goals, World Bank advocacy for early childhood education, and International Labour Organization campaigns to eliminate child labour, all combine to generate policies that shape children’s lives, changing the way they, their families, and their communities perceive childhood and the appropriate use of children’s time. The content of children’s activities is linked to social values and power relationships within households, institutions, and communities (Morrow and Boyden 2010). In contexts of poverty and other adversities, economic pressures structure children’s time to a considerable degree (and these differ according to children’s gender and whether they live in urban or rural areas). However, the pace of change in developing countries is unprecedented, with somewhat uneven consequences for poverty reduction.</p

Changes in Rural Children’s Use of Time: Evidence from Ethiopia and Andhra Pradesh

In recent decades, children’s time has become a global commodity, fought over by a range of national and international policymakers (Stephens 1995). Ambitious global social policies construct particular visions of childhood and, in doing so, shape how children spend their time. The Millennium Development Goals, the Education For All Dakar Goals, World Bank advocacy for early childhood education, and International Labour Organization campaigns to eliminate child labour, all combine to generate policies that shape children’s lives, changing the way they, their families, and their communities perceive childhood and the appropriate use of children’s time. The content of children’s activities is linked to social values and power relationships within households, institutions, and communities (Morrow and Boyden 2010). In contexts of poverty and other adversities, economic pressures structure children’s time to a considerable degree (and these differ according to children’s gender and whether they live in urban or rural areas). However, the pace of change in developing countries is unprecedented, with somewhat uneven consequences for poverty reduction.</p

Urinary biomarkers of physical activity: candidates and clinical utility

Chronic physical inactivity is a major risk factor for a number of important lifestyle diseases, while inappropriate exposure to high physical demands is a risk factor for musculoskeletal injury and fatigue. Proteomic and metabolomic investigations of the physical activity continuum - extreme sedentariness to extremes in physical performance - offer increasing insight into the biological impacts of physical activity. Moreover, biomarkers, revealed in such studies, may have utility in the monitoring of metabolic and musculoskeletal health or recovery following injury. As a diagnostic matrix, urine is non-invasive to collect and it contains many biomolecules, which reflect both positive and negative adaptations to physical activity exposure. This review examines the utility and landscape of biomarkers of physical activity with particular reference to those found in urine