Lifelongα-tocopherol supplementation increases the median life span of C57BL/6 mice in the cold but has only minor effects on oxidative damage

The effects of dietary antioxidant supplementation on oxidative stress and life span are confused. We maintained C57BL/6 mice at 7 ± 2°C and supplemented their diet with α-tocopherol from 4 months of age. Supplementation significantly increased (p = 0.042) median life span by 15% (785 days, n = 44) relative to unsupplemented controls (682 days, n = 43) and also increased maximum life span (oldest 10%, p = 0.028). No sex or sex by treatment interaction effects were observed on life span, with treatment having no effect on resting or daily metabolic rate. Lymphocyte and hepatocyte oxidative DNA damage and hepatic lipid peroxidation were unaffected by supplementation, but hepatic oxidative DNA damage increased with age. Using a cDNA macroarray, genes associated with xenobiotic metabolism were significantly upregulated in the livers of female mice at 6 months of age (2 months supplementation). At 22 months of age (18 months supplementation) this response had largely abated, but various genes linked to the p21 signaling pathway were upregulated at this time. We suggest that α-tocopherol may initially be metabolized as a xenobiotic, potentially explaining why previous studies observe a life span extension generally when lifelong supplementation is initiated early in life. The absence of any significant effect on oxidative damage suggests that the life span extension observed was not mediated via any antioxidant properties of α-tocopherol. We propose that the life span extension observed following α-tocopherol supplementation may be mediated via upregulation of cytochrome p450 genes after 2 months of supplementation and/or upregulation of p21 signaling genes after 18 months of supplementation. However, these signaling pathways now require further investigation to establish their exact role in life span extension following α-tocopherol supplementation

Response to Farrokhi et al.'s statistical comments on 'no seasonal variation in physical activity of Han Chinese living in Beijing'

Peer reviewedPublisher PD

Testing the carbohydrate insulin model in mice : Erroneous critique does not alter previous conclusion

We are grateful to Dr Kevin Hall of the NIH for comments on an earlier draft of this paper, and Dr Stephan Guyenet for his informative blog posts on the CIM. Our study of mouse diets was funded by the strategic research program of the Chinese Academy of Sciences (XDB13030100).Peer reviewedPublisher PD

Regulation of intestinal growth in response to variations in energy supply and demand

Biotechnology and Biological Sciences Research Council (BBSRC). Grant Number: BB/P009875/1 Science Foundation Ireland. Grant Number: SFI/16/BBSRC/3389Peer reviewedPublisher PD

Basic Salts with »Very Short« Hydrogen Bonds; the Crystal Structure of a-Picoline-N-oxide Hemihydrochloride Sesquihydrate (Dunlop\u27s Salt)

Type A acid salts of many simple carboxylic acids (HX) crystallise with anions, XHx-, which are symmetrical and which contain »very short« OHO-bonds with O . .. 0 less than 250 pm. Such compounds also reveal anomalous IR spectra. The Glasgow work on such crystal structures has benefited from a long collaboration with Hadzi\u27s spectroscopic group at Ljubljana. The importance of such joint studies in helping the understanding of strong hydrogen bonding is discussed. Some organic bases form analogous basic salts, which have similarly anomalous spectra. An example, discovered by Hadzi in 1962, is the hemihydrobromide of a.-picoline-N-oxide, B · 1/2HBr, where B = CoH7NO, for which he predicted the formula BHB+ Br-. Preliminary X-ray work confirmed this and the presence of a »very short« OHO-bond. Hitherto unpublished crystallographic work is summarised. Dunlop\u27s salt is the sesquihydrated hemihydrochloride of the same base. A careful X-ray study has been made (1040 reflexions; R = 3.70/o): B · 1/2HCl · 3/2H20 has a structure corresponding to BHB+ c1- · 3H20; the cation lies across a centre of symmetry, with O ... O = 241.4(3) pm. At one stage the salt was supposed to include a symmetrical ClHc1- anion; but our more precise work shows the anion to be c1- ... H-OH (or HO-H ... en symmetrised by disorder across a twofold axis of the crystal, with c1- ... O = = 297(1) pm. The spectrum of DSALT is almost identical with that of the hemihydrobromide

Trapped in the darkness of the night: thermal and energetic constraints of daylight flight in bats

Bats are one of the most successful mammalian groups, even though their foraging activities are restricted to the hours of twilight and night-time. Some studies suggested that bats became nocturnal because of overheating when flying in daylight. This is because—in contrast to feathered wings of birds—dark and naked wing membranes of bats efficiently absorb short-wave solar radiation. We hypothesized that bats face elevated flight costs during daylight flights, since we expected them to alter wing-beat kinematics to reduce heat load by solar radiation. To test this assumption, we measured metabolic rate and body temperature during short flights in the tropical short-tailed fruit bat Carollia perspicillata at night and during the day. Core body temperature of flying bats differed by no more than 2°C between night and daytime flights, whereas mass-specific CO2 production rates were higher by 15 per cent during daytime. We conclude that increased flight costs only render diurnal bat flights profitable when the relative energy gain during daytime is high and risk of predation is low. Ancestral bats possibly have evolved dark-skinned wing membranes to reduce nocturnal predation, but a low degree of reflectance of wing membranes made them also prone to overheating and elevated energy costs during daylight flights. In consequence, bats may have become trapped in the darkness of the night once dark-skinned wing membranes had evolved

Charter School Funding: Inequity Expands

The revenue study is based on Fiscal Year 2010‒11 (FY11) data for each of 30 selected states plus the District of Columbia (D.C.). Traditional school districts and public charter schools were analyzed and aggregated “statewide.” For each state, one to three “focus areas” were selected based on larger concentrations of charter students – most focus areas are large cities, some are metropolitan counties. Traditional school districts and charter schools were analyzed separately in each focus area. The analytic team collected and analyzed all revenues, public and private, flowing to traditional district and public charter schools. FY11 funding includes Federal, State, Local, Other, PublicIndeterminate, and Indeterminate sources

The Productivity of Public Charter Schools

This is the first national study of the productivity of public charter schools relative to district schools. This report is a follow up to the charter school revenue study, Charter School Funding: Inequity Expands, released in April 2014 by the School Choice Demonstration Project at the University of Arkansas. That study was authored by the same research team that crafted this report. In the revenue study, per pupil revenues for public charter schools and traditional public schools (TPS) were compared. The research team found that during the 2010-11 school year (FY11), charter-school students across 30 states and the District of Columbia on average received $3,814 less in funding than TPS students, a funding gap of 28.4 percent