Kinetic analysis of the psychrophilic anaerobic digestion of wastewater derived from the production of proteins from extracted sunflower flour

A kinetic analysis of the anaerobic digestion process of wastewater derived from the production of protein isolates from extracted sunflower flour was carried out. The digestion was conducted in a laboratory-scale fluidized bed reactor with saponite (magnesium silicate) as support for the mediating bacteria at psychrophilic temperature (15-19 degrees C). Soluble chemical oxygen demand (COD(s)) removal efficiencies in the range of 95.9-69.0% were achieved in the reactor at organic loading rates (OLR) of between 0.57 and 2.49 g total COD (COD(t))/L d, hydraulic retention times (HRT) of between 20.0 and 4.5 days, and average feed total COD concentration of 11.3 g/L. The yield coefficient of methane production was 0.32 L of methane (at STP) per gram of COD(t) removed. The total volatile fatty acid (TVFA) levels and the TVFA/alkalinity ratio were lower than the suggested limits for digester failure for OLR and HRT up to 2.26 g COD(t)/L d and 5.0 days, respectively. The specific rate of substrate uptake, r (g COD(s)/g VSS d), correlated with the concentration of biodegradable substrate, S (g COD(s)/L), through an equation of the Michaelis-Menten type. The maximum substrate utilization rate, k, and the Michaelis constant, K(s)(), were found to be 0.125 g COD(s)/g VSS d and 124 mg COD(s)/L, respectively. This proposed model predicted the behavior of the reactor very accurately showing deviations lower than 10% between the experimental and theoretical values of substrate uptake rates. A mass (COD(t)) balance around the reactor allowed the COD equivalent of methane volume (W(CH)4) to be obtained, which gave a value of 2.89 g COD(t)/L CH(4), which was virtually coincident with the theoretical value of 2.86 g COD(t)/L CH(4).     

The effect of urine acidification on calcium oxalate relative supersaturation in cats

There is an apparent reciprocal relationship between magnesium ammonium phosphate (MAP, struvite) and calcium oxalate (CaOx) urolithiasis incidence rate in cats. The number of struvite uroliths submitted for analysis over the past 35 years has been decreasing, with an increase in CaOx urolith submissions. Commercial diets aimed to dissolve struvite uroliths are typically acidified, and it has been suggested that dietary acidification increases urinary calcium excretion and the risk of CaOx crystallization. The objective of this study was to assess the effect of urine acidification on the relative supersaturation (RSS) of CaOx in cats, as a representation of crystallization risk. Four diets were extruded to contain identical nutrient contents, but with gradual acidification (0, 0.6, 1.3 and 1.9% sodium bisulphate substituted sodium chloride in diets A, B, C and D respectively). Thirteen adult cats were fed each diet sequentially for a minimum of 10 days. Average urine pH was 6.4, 6.2, 6.0 and 5.9 on diets A, B, C and D respectively (p < 0.0001). Struvite RSS decreased on diets inducing more acidic urine pH (p < 0.0001). Urinary calcium excretion and concentration increased with diets inducing lower urine pH (p < 0.0001), but oxalate excretion and concentration decreased (p < 0.001). CaOx RSS was not different between diets (p = 0.63). These results suggest that a lower diet base excess and resulting urine pH to support struvite dissolution do not increase the risk for CaOx crystallization in the range of urine pH representative of most commercial feline diets. Long-term studies are needed to confirm this.     

Urinary excretion of advanced glycation end products in dogs and cats

The present study was conducted with privately owned dogs and cats to investigate whether a relationship exists between the dietary AGEs and the urinary excretion of AGEs, as indication of possible effective absorption of those compounds in the intestinal tract of pet carnivores. For this purpose, data were collected from both raw fed and dry processed food (DPF) fed to dogs and cats, through spot urine sampling and questionnaires. Raw pet food (RF, low in AGE diets) was fed as a primary food source to 29 dogs and DPF to 28 dogs. Cats were categorized into 3 groups, which were RF (n = 15), DPF (n = 14) and dry and wet processed pet food (DWF, n = 25). Urinary-free carboxymethyllysine (CML), carboxyethyllysine (CEL) and lysinoalanine (LAL) were analysed using ultrahigh-performance liquid chromatography (UHPLC)—mass spectrometry, and were standardized for variable urine concentration by expressing the AGE concentrations as a ratio to urine creatinine (Ucr) concentration (µg/µmol Ucr). Urinary excretion of CML, CEL and LAL in dogs fed with DPF was 2.03, 2.14 and 3 times higher compared to dogs fed with RF (p < .005). Similar to the dogs, a significant difference in CML:Ucr, CEL:Ucr and LAL:Ucr between the three diet groups was observed in cats (p-overall < 0.005, ANOVA), in which the RF fed group excreted less AGEs than the other groups. Linear regression coefficients and SE of CML:Ucr, CEL:Ucr and LAL:Ucr showed that body weight and neuter status were significantly correlated with CML and CEL excretion, but not to LAL excretion. Our results revealed a significant correlation between dietary AGEs and urinary excretion of free CML, CEL and LAL, and also showed that endogenous formation of these AGEs occurs in both dogs and cats under physiological conditions.     

Alcohol intake in relation to body mass index and waist-to-hip ratio: the importance of type of alcoholic beverage

OBJECTIVE: Alcohol consumption may play a role in the development of obesity but the relationship between alcohol and weight is still unclear. The aim of our study was to assess the cross-sectional association of intakes of total alcohol and of specific alcoholic beverages (wine, beer and spirits) with waist-to-hip ratio (WHR) and body mass index (BMI) in a large sample of adults from all over France. DESIGN: Cross-sectional. SETTING: Participants were free-living healthy volunteers of the SU.VI.MAX study (an intervention study on the effects of antioxidant supplementation on chronic diseases). SUBJECTS: For 1481 women aged 35-60 years and 1210 men aged 45-60 years, intakes of total alcohol and specific alcoholic beverages were assessed by six 24-hour dietary records. BMI and WHR were measured during a clinical examination the year after. RESULTS: A J-shaped relationship was found between total alcohol consumption and WHR in both sexes and between total alcohol consumption and BMI in men only (P<0.05). The same relationships were observed with wine (P<0.05); men and women consuming less than 100 g day(-1) had a lower BMI (men only) and WHR than non-drinkers or those consuming more. Spirits consumption was positively associated with BMI (linear regression coefficient beta=0.21, 95% confidence interval (CI): 0.09-0.34 and beta=0.22, 95% CI: 0.06-0.39 for men and women, respectively) and WHR (beta=0.003, 95% CI: 0.001-0.005 and beta=0.003, 95%CI: 0.0002-0.006) in both sexes in a linear fashion. No relationship between beer consumption and BMI or WHR was found. CONCLUSION: If confirmed in longitudinal studies, our results indicate that consumption of alcoholic beverages may be a risk factor for obesity.     

Rule learning by rats

Using rules extracted from experience to solve problems in novel situations involves cognitions such as analogical reasoning and language learning and is considered a keystone of humans' unique abilities. Nonprimates, it has been argued, lack such rule transfer. We report that Rattus norvegicus can learn simple rules and apply them to new situations. Rats learned that sequences of stimuli consistent with a rule (such as XYX) were different from other sequences (such as XXY or YXX). When novel stimuli were used to construct sequences that did or did not obey the previously learned rule, rats transferred their learning. Therefore, rats, like humans, can transfer structural knowledge from sequential experiences.     

Exotic invasive knotweeds (Fallopia spp.) negatively affect native plant and invertebrate assemblages in European riparian habitats

Invasive plants are, simply by occupying a large amount of space in invaded habitats, expected to impose a significant impact on the native vegetation and their associated food webs. However, little is known about the impact of invasive plants both on native vegetation and on different invertebrate feeding guilds at the habitat level. Yet, studies addressing multiple trophic levels, e.g. plant species, herbivores, predators and detrivores, are likely to yield additional insight into how and under which conditions invasive weeds alter ecosystem structures and processes. We set out to assess whether plant species richness and invertebrate assemblages in European riparian habitats invaded by exotic knotweeds (Fallopia spp.) differed from those found in native grassland- or bush-dominated riparian habitats, which are both potentially threatened by knotweed invasion. Our findings suggest that riparian habitats invaded by knotweeds support lower numbers of plant species and lower overall abundance and morphospecies richness of invertebrates, compared to native grassland-dominated and bush-dominated habitats. Total invertebrate abundance and morphospecies richness in Fallopia-invaded riparian habitats were correlated with native plant species richness, suggesting that there is a link between the replacement of native plant species by exotic Fallopia species and the reduction in overall invertebrate abundance and morphospecies richness. Moreover, biomass of invertebrates sampled in grassland and bush-dominated habitats was almost twice as high as that in Fallopia-invaded habitats. Large-scale invasion by exotic Fallopia species is therefore likely to seriously affect biodiversity and reduce the quality of riparian ecosystems for amphibians, reptiles, birds and mammals whose diets are largely composed of arthropods.     

Optical detection of DNA conformational polymorphism on single-walled carbon nanotubes

The transition of DNA secondary structure from an analogous B to Z conformation modulates the dielectric environment of the single-walled carbon nanotube (SWNT) around which it is adsorbed. The SWNT band-gap fluorescence undergoes a red shift when an encapsulating 30-nucleotide oligomer is exposed to counter ions that screen the charged backbone. The transition is thermodynamically identical for DNA on and off the nanotube, except that the propagation length of the former is shorter by five-sixths. The magnitude of the energy shift is described by using an effective medium model and the DNA geometry on the nanotube sidewall. We demonstrate the detection of the B-Z change in whole blood, tissue, and from within living mammalian cells.     

Liming and Fertilizer Potentials of Some Underutilized Plant Materials in Southwestern Nigeria

Soil acidification and phosphorus deficiency are a major constraint to crop production in tropical soils.Use of conventional liming materials is associated with some limitations viz:inability to solely improve nitrogen and available phosphorus in soils,loss of soil organic carbon and soil aggregate stability.Liming and fertilizer potentials of leaves from three plant materials(Tithonia diversifolia(TL),Imperata cylindrica(SG)and Gliricidia sepium(GL))widely growing in Ogbomoso,southwest Nigeria,were tested under incubation condition.Each of the plant material was applied at the rate of 10 t·hm~(-2) with and without 50%concentration of NPK 15:15:15-urea mix in 500 g acidic soil.Sole lime applied at 1 t·hm~(-2),sole NPK 15:15:15 applied at 60 kg·hm~(-2) mixed with urea at 60 kg N·hm~(-2) and an unamended soil were compared in completely randomized design in three replicates.The treated soils were incubated for 12 weeks.Thereafter,maize seeds were raised in each pot for a period of 3 weeks.Data collected were subjected to analysis of variance.Regression analysis was used to predict contributions of increased soil p H in plant material treated soils to exchangeable Al,H,dry root weight of maize and available phosphorus.Results indicated that sole plant materials were the order SGTLGL significantly(p0.05)reduced exchangeable acidity compared to unamended and sole NPK.Sole NPK had the highest exchangeable acidity(4.7 cmol·kg~(-1))compared to unamended soil(3.3 cmol·kg~(-1))and sole lime(2.7 cmol·kg~(-1)).Application of sole Tithonia diversifolia increased available phosphorus by 214%and 97%compared to unamended and sole NPK treated soils respectively.Sole plant materials increased maize root weight by 33%compared to sole NPK.Increasing soil p H at harvesting in plant material treated soils significantly reduced exchangeable H and A_1.Soil p H was responsible for up to 33%and 53%reductions in exchangeable Al and H,respectively.This culminated into up to 22%increases in dry root weight of maize seedling.Present results showed ability of the plant materials tested to ameliorate soil acidity and improved soil available phosphorus.The plant materials should be explored for using as green manure and composting feedstock.It will go a long way to reduce high dosage use of conventional liming and fertilizer materials on acidic nutrient degraded soils.