Use of 31P magnetisation transfer magnetic resonance spectroscopy to measure ATP changes after 670 nm transcranial photobiomodulation in older adults

Mitochondrial function declines with age, and many pathological processes in neurodegenerative diseases stem from this dysfunction when mitochondria fail to produce the necessary energy required. Photobiomodulation (PBM), long-wavelength light therapy, has been shown to rescue mitochondrial function in animal models and improve human health, but clinical uptake is limited due to uncertainty around efficacy and the mechanisms responsible. Using ³¹P magnetisation transfer magnetic resonance spectroscopy (MT-MRS) we quantify, for the first time, the effects of 670 nm PBM treatment on healthy ageing human brains. We find a significant increase in the rate of ATP synthase flux in the brain after PBM in a cohort of older adults. Our study provides initial evidence of PBM therapeutic efficacy for improving mitochondrial function and restoring ATP flux with age, but recognises that wider studies are now required to confirm any resultant cognitive benefits.     

Comparisons of biomass,water use efficiency and water use strategies across five genomic groups of Populus and its hybrids

Genetic improvement and hybridization in the Populus genus have led to the development of genotypes exhibiting fast growth, high rooting ability and disease resistance. However, while large biomass production is important for bioenergy crops, efficient use of resources including water is also important in sites lacking irrigation and for maintaining ecosystem water availability. In addition, comparison of water use strategies across a range of growth rates and genetic variability can elucidate whether certain strategies are shared among the fastest growing and/or most water use efficient genotypes. We estimated tree water use throughout the second growing season via sapflow sensors of 48 genotypes from five Populus taxa; P. deltoides W. Bartram ex Marshall × P. deltoides (D × D), P. deltoides × P. maximowiczii A. Henry (D × M), P. deltoides × P. nigra L. (D × N), P. deltoides × P. trichocarpa Torr. & Gray (D × T) and P. trichocarpa × P. deltoides (T × D) and calculated average canopy stomatal conductance (G_S). We regressed G_S and atmospheric vapor pressure deficit (VPD) wherein the slope of the relationship represents stomatal sensitivity to VPD. At the end of the second growing season, trees were harvested, and their dry woody biomass was used to calculate whole tree water use efficiency (WUE_T). We found that D × D and D × M genotypes exhibited differing water use strategies with D × D genotypes exhibiting high stomatal sensitivity while retaining leaves while D × M genotypes lost leaf area throughout the growing season but exhibited low stomatal sensitivity. Across measured taxa, biomass growth was positively correlated with WUE_T, and genotypes representing each measured taxa except D × N and T × D had high 2-year dry biomass of above 6 kg/tree. Overall, these data can be used to select Populus genotypes that combine high biomass growth with stomatal sensitivity and WUE_T to limit the negative impacts of bioenergy plantations on ecosystem water resources.     

Effects of bovine colostrum supplementation on serum IGF-I, IgG, hormone, and saliva IgA during training

Mero, Antti, Heidi Miikkulainen, Jarmo Riski, RaimoPakkanen, Jouni Aalto, and Timo Takala. Effects of bovinecolostrum supplementation on serum IGF-I, IgG, hormone, and saliva IgAduring training. J. Appl. Physiol.83(4): 1144-1151, 1997.The purpose of this study was to examinethe effects of bovine colostrum supplementation (Bioenervi) on seruminsulin-like growth factor I (IGF-I), immunoglobulin G, hormone, andamino acid and saliva immunoglobulin A concentrations during a strengthand speed training period. Nine male sprinters and jumpersunderwent three randomized experimental training treatments of 8 daysseparated by 13 days. The only difference in the treatments was thedrink of 125 ml consumed per day. Posttraining increases were noticedfor serum IGF-I in the 25-ml Bioenervi treatment (125 ml contained 25 ml Bioenervi) and especially in the 125-ml Bioenervi treatment (125 mlcontained 125 ml Bioenervi) compared with the placebo (normal milkwhey) treatment (P < 0.05). The change in IGF-I concentration during the 8-day periods correlated positively with the change in insulin concentration during the sameperiods with 25-ml Bioenervi treatment(r = 0.68;P = 0.045) and with 125-ml Bioenervitreatment (r = 0.69;P = 0.038). Serum immunoglobulin G,hormone, and amino acid and saliva immunoglobulin A responses weresimilar during the three treatments. It appears that a bovine colostrumsupplement (Bioenervi) may increase serum IGF-I concentration inathletes during strength and speed training.

     

Effects of autoclave-induced carbohydrate hydrolysis on the growth ofBeta vulgaris cells in suspension

Media of de Greef & Jacobs (1979) were autoclaved either with all the nutrient components in a single vessel (medium 1) or with the following components in separate vessels: FeNa–EDTA+CaCl₂ (medium 2), FeNa–EDTA+NaH₂PO₄ (medium 3) or sucrose (medium 4). Medium 5 was prepared by autoclaving FeNa–EDTA+NaH₂PO₄ and sucrose in two separate vessels. It was found that the dry mass yield of cell suspensions ofBeta vulgaris was lowest in medium 1, followed by media 2 and 3. There was no significant difference among media 3, 4, and 5.The plot of dry mass yield of the cell suspensions against the rates of cyanide-initiated oxygen consumption which indicate the extent of carbohydrate hydrolysis of the media during autoclaving, indicated the presence of a threshold rate of about 17–20 nmol ml^–1 min^–1. Dry mass yield of the suspensions decreased rapidly when the rate exceeded this value.For media with glucose as the source of carbohydrate, the rate of cyanide-initiated oxygen consumption exceeded the threshold value by a factor of 1.5 to 2, depending on the volume of the media autoclaved.Abbreviations FeNa-EDTA ferric monosodium ethylenediamine-tetraacetic acid     

Effects of diphenyl ether herbicides on porphyrin accumulation by cultured hepatocytes

Several diphenyl ether herbicides, such as acifluorfen methyl, have been previously shown to cause large accumulations of the heme and chlorophyll precursor, protoporphyrin, in plants. Lightinduced herbicidal damage is mediated by the photoactive porphyrin. Here we investigate whether diphenyl ether herbicides can affect porphyrin synthesis in rat and chick hepatocytes. In rat hepatocyte cultures, protoporphyrin, as well as coproporphyrin, accumulated after treatment with acifluorfen or acifluorfen methyl. Combination of acifluorfen methyl with an esterase inhibitor to prevent the conversion of acifluorfen methyl to acifluorfen resulted in a greater accumulation of porphyrins than caused by acifluorfen methyl or acifluorfen alone. In vitro enzyme studies of hepatic mitochondria isolated from rat and chick embryos demonstrated that protopor-phyrinogen oxidase, the penultimate enzyme of heme biosynthesis, was inhibited by low concentrations of acifluorfen, nitrofen, or acifluorfen methyl with the latter being the most potent inhibitor. These findings indicate that diphenyl ether treatment can cause protoporphyrin accumulation in rat hepatocyte cultures and suggest that this accumulation was associated with the inhibition of protoporphyrinogen oxidase. In cultured chick embryo hepatocytes, treatment with acifluorfen methyl plus an esterase inhibitor caused massive accumulation of uroporphyrin rather than protoporphyrin or coproporphyrin. Specific isozymes of cytochrome P450 were also induced in chick embryo hepatocytes. These effects were not observed in the absence of an esterase inhibitor. These results suggest that diphenyl ether herbicides can cause uroporphyrin accumulation similar to that induced by other cytochrome P450-inducing chemicals such as polyhalogenated aromatic hydrocarbons in the chick hepatocyte system.     

Influence of the estrous cycle on heterosexual aggression in two strains of rats (S3 and WEzob)

Two strains of rats (S₃ and WEzob), which show different levels of aggression in the laboratory, were tested in repeated heterosexual confrontations. Daily 15-min observations were made of the interactions between a female throughout a complete estrous cycle and the same male partner. In both strains the topography of aggression was similar in males and females, but the frequency of specific parameters varied. Males showed more offensive and females more defensive patterns. The overall level of aggression was very low on the day of estrous, when the female was sexually receptive. There were no differences in any elements of female or male behavior between the other 3 days of the cycle. The results support previous conclusions from single-sex encounters that in rats there is no sexual dimorphism in the ability to show aggression.     

The cultural evolution of fertility decline

Cultural evolutionists have long been interested in the problem of why fertility declines as populations develop. By outlining plausible mechanistic links between individual decision-making, information flow in populations and competition between groups, models of cultural evolution offer a novel and powerful approach for integrating multiple levels of explanation of fertility transitions. However, only a modest number of models have been published. Their assumptions often differ from those in other evolutionary approaches to social behaviour, but their empirical predictions are often similar. Here I offer the first overview of cultural evolutionary research on demographic transition, critically compare it with approaches taken by other evolutionary researchers, identify gaps and overlaps, and highlight parallel debates in demography. I suggest that researchers divide their labour between three distinct phases of fertility decline—the origin, spread and maintenance of low fertility—each of which may be driven by different causal processes, at different scales, requiring different theoretical and empirical tools. A comparative, multi-level and mechanistic framework is essential for elucidating both the evolved aspects of our psychology that govern reproductive decision-making, and the social, ecological and cultural contingencies that precipitate and sustain fertility decline.