Relationship between dietary fiber levels and protein digestibility in selected foods as determined in rats

Samples of 15 food products and feces obtained by feeding them to rats were analysed for dietary fiber fractions. The food products were added as the sole source of protein in 8% protein diets, making up 8.8–51.6% of the diets. Diets were supplemented with 0.54–5.00% purified cellulose to make them more comparable in total fiber. Fiber analyses of food products revealed that the protein sources provided 0.06–7.27% total dietary fiber. The true protein digestibility in rats was negatively correlated with the total food fiber level (r=–0.69,P<0.01) or with the food cellulose level (r=–0.82,P<0.01) but it was positively correlated (r=+0.81,P<0.01) with the purified cellulose level. No relationship was found between protein digestibility and fiber fermentability. Results indicate that several food fiber fractions and possibly associated substances influenced protein digestibility. Purified cellulose did not have the same physiological behavior as food cellulose from the viewpoint of protein digestibility and fiber fermentability.     

Influence of tryptophan supplementation of soy-based infant formulas on protein quality and on blood and brain tryptophan and brain serotonin in the rat model

A 2-wk feeding study with weanling rats was conducted to investigate theeffects of tryptophan supplementation of soy-based infant formulas on proteinquality and on the levels of blood and brain tryptophan and brain serotoninand 5-HIAA (5-hydroxyindole-3-acetic acid), a metabolite of serotonin. Thepowder and liquid concentrate forms of soy-based infant formulas obtainedfrom four manufacturers were tested. The tryptophan contents of the testsoy-based formulas (10.0–12.3 mg/g protein) were considerably lower comparedto those of human milk (17–19 mg/g protein). The infant formulas were fedas the sole source of protein in diets containing 8% protein, 20% fat, 5%cellulose and adequate amounts of minerals and vitamins. In general, supplementation of the diets containing test formulas with graded levels ofL-tryptophan (0.1 or 0.2%) had no effect on protein quality indices basedon rat growth such as PER (protein efficiency ratio), NPR (net protein ratio)and relative NPR (RNPR), but resulted in significant (p<;0.05) increases inthe concentrations of tryptophan in the plasma and brain, and serotonin and5-HIAA in brain of rats. The increased concentrations of brain tryptophan and5-hydroxyindoles (serotonin + 5-HIAA) in rats fed tryptophan-supplementedformulas compared to those fed unsupplemented formulas support the need forfurther research to investigate the influence of tryptophan supplementationof soy-based infant formulas on tryptophan metabolites and their potentialrelated effects on sleep latency and neurobehavioral developments in infants.     

Spatio-temporal variability of drought characteristics across Pakistan

Climate change in Pakistan has a great impact on the spatial and temporal variation of precipitation and ultimately alters the frequency and duration of droughts. In this study, spatial and temporal trend analyses of precipitation and droughts were observed at 58 meteorological stations across Pakistan from 1981 to 2018. The existing trend analysis methods were evaluated to address the issue of serial correlation in the climatic data. Results of precipitation analysis showed significant decreasing trends in winter (November, December) and significant increasing trends were observed in summer (June and September) at a confidence level of 95 percent. The magnitude of the precipitation trends showed the highest variation during summer season and the least variation in winter season. Rotated Principal Component (RPC) analysis showed the severe droughts (high positive loading) in southeastern side (Sindh province) of Pakistan due to lack of summer rains. Furthermore, variance correction approaches are identified as the most suitable in coping with the effect of serial correlation. The highest drought frequencies were observed in the southern areas of Pakistan and the drought events are expected to occur more frequently in the late winter, early spring, and early autumn, while droughts were expected to occur least frequently in summer.

     

Impact of Exogenous Application of Salicylic Acid on Growth,Water Status And Antioxidant Enzyme Activity of Strawberry Plants (Fragaria vesca L.) Under Salt Stress Conditions

Irrigation with saline water can act as an alternate water resource and thus plays an important role in saving freshwater resources as well as promoting agriculture. Furthermore, salinity stress is considered one of the major abiotic stress factors, which strongly reduces crop productivity. In this context, the present work was conducted to examine the effect of exogenous salicylic acid (SA) application on salt stress tolerance of strawberry plants. For this purpose, strawberry plants (Fragaria vesca L.), three months old, were treated with three SA concentrations (0?mM, 0.25?mM and 0.5?mM), then subjected to 80?mM NaCl or not. After five weeks of treatment, growth responses, water status, photochemical efficiency and oxidative stress indicators were measured. The obtained results showed that irrigation with saline water negatively affected the growth parameters, the leaf water potential (LWP), the relative water content (RWC), the stomatal conductance (gs) and photochemical efficiency (Fv/Fm). While, the total protein content, the electrolyte leakage (EL), the malondialdehyde (MDA) and the hydrogen peroxide (H₂O₂) contents were increased in stressed plants compared to unstressed ones. Salt stress also leads to the activation of the antioxidant enzymes. However, the exogenous application of SA under salt stress conditions reduced the H₂O₂ accumulation, the electrolyte leakage and the MDA content. It has also improved the growth parameters, the LWP, the RWC, the gs, the Fv/Fm, the protein content and the antioxidant enzyme activities (POD, CAT and SOD) in the treated plants compared to those without SA application. Therefore, the beneficial effect of 0.25?mM SA on Fragaria vesca L. salinity tolerance may provide some practical basis for strawberry cultivation under saline conditions.

     

Seed dimorphism,chromosome number and karyotype of the amphicarpic species <Emphasis Type="Italic">Trifolium argentinense</Emphasis> Speg.

Amphicarpy, a specialized form of dimorphism where fruits and seeds are formed in underground and aerial flowers, has been reported in only ca. 50 flowering plants. Trifolium argentinense Speg. is an amphicarpic legume species that occurs in native pastures of Southern Brazil. Data on seed dimorphism, chromosome number and karyotype of the species are presented for the first time. T. argentinense is diploid, with 2n = 2x = 16. Chromosome size range from ca. 2.8 to 1.6 μm, the karyotypic formula is 3 metacentric + 1 satellite-bearing metacentric + 3 acrocentric + 1 subacrocentric and a TCL (total complement length) of 18.10 μm. All the subterranean, but around 70% of the aerial legumes formed seeds. Subterranean seeds were larger and heavier (2.1 mm and 0.0029 g, respectively) than the aerial ones (1.8 mm and 0.0016 g, respectively). As a follow up to this work, we plan to characterize aerial and subterranean-seed-derived plants regarding aspects such as growing rate, height, leaf size and forage production, as well as to determine the exact mode of reproduction of T. argentinense by pollination experiments and the use of molecular markers.     

Effect of different non-chloride sodium sources on the performance of heat-stressed broiler chickens

1. One hundred and eighty 1-d-old broiler chicks were used to evaluate the effect upon broiler performance during severely hot summer months of three different sodium salts: sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3) and sodium sulphate (Na2SO4), in starter and finisher diets having an identical electrolyte balance (DEB) of 250 mEq/kg. 2. The non-chloride sodium salts were added to contribute the same amount of sodium and were substituted at the expense of builder's sand in the basal diets containing common salt (NaCl) as Na and Cl source. 3. Each diet was fed to three experimental units having 15 chicks each until 42 d of age. Severe heat-stress conditions, maintained in the rearing room, were indicated by high average weekly room temperature (minimum 29.3 degrees C; maximum 38.0 degrees C). 4. Diets containing sodium salts gave better body weight gain, feed intake and feed to gain ratio than the control diet. Sodium salts also enhanced water intake as well as water to feed intake ratio. This effect was more pronounced in broilers fed NaHCO3 supplement (with NaCl in the basal diets). 5. The increased water intake resulted in lower body temperature in heat-stressed birds fed NaHCO3 supplemented diet than in birds fed other sodium salts. A lower mortality rate was noted with NaHCO3 (15.15%), Na2CO3 (13.64%) and Na2SO4 (15.15%) supplements than with the control (33.33%) treatment. 6. Better carcase and parts yield were observed in sodium supplemented broilers. Sodium salts reduced the alkalotic pH and enhanced the blood sodium content, which ultimately improved the blood electrolyte balance and overall performance of heat-stressed broilers. 7. Supplementing broiler diets with sodium salts improved the live performance of heat-stressed broilers and better productive performance was noted with NaHCO3 than other sodium supplements.     

Type, density, and location of immune cells within human colorectal tumors predict clinical outcome

The role of the adaptive immune response in controlling the growth and recurrence of human tumors has been controversial. We characterized the tumor-infiltrating immune cells in large cohorts of human colorectal cancers by gene expression profiling and in situ immunohistochemical staining. Collectively, the immunological data (the type, density, and location of immune cells within the tumor samples) were found to be a better predictor of patient survival than the histopathological methods currently used to stage colorectal cancer. The results were validated in two additional patient populations. These data support the hypothesis that the adaptive immune response influences the behavior of human tumors. In situ analysis of tumor-infiltrating immune cells may therefore be a valuable prognostic tool in the treatment of colorectal cancer and possibly other malignancies.     

Ecological populations of bacteria act as socially cohesive units of antibiotic production and resistance

In animals and plants, social structure can reduce conflict within populations and bias aggression toward competing populations; however, for bacteria in the wild it remains unknown whether such population-level organization exists. Here, we show that environmental bacteria are organized into socially cohesive units in which antagonism occurs between rather than within ecologically defined populations. By screening approximately 35,000 possible mutual interactions among Vibrionaceae isolates from the ocean, we show that genotypic clusters known to have cohesive habitat association also act as units in terms of antibiotic production and resistance. Genetic analyses show that within populations, broad-range antibiotics are produced by few genotypes, whereas all others are resistant, suggesting cooperation between conspecifics. Natural antibiotics may thus mediate competition between populations rather than solely increase the success of individuals.     

Biodiversity conservation in human-modified Amazonian forest landscapes

Amazonia (sensu lato) is by far the largest tropical forest region, but has succumbed to the highest absolute rates of tropical deforestation and forest degradation, driven by rapid frontier expansion, road-building, and spontaneous or government-subsidized migration. The large area-through-time and paleo-climatic stability of Amazonian forests may help explain the high regional to local scale plant and animal species diversity of true forest specialists and high ecological sensitivity to contemporary land-use change. We describe the prevailing forms of anthropogenic disturbance that affect forest organisms in the context of the geographic and evolutionary background that has shaped the degree to which forest species may be resilient to environmental change. The fate of Amazonian biodiversity will partly depend upon the interaction between land-use and climate change, and the extent to which seasonally-dry forests can retain immunity against catastrophic recurrent wildfires. This review illustrates the importance of considering interactions between different forms of forest disturbance to develop effective conservation policy. We conclude with some considerations of the policy agenda necessary to protect forest cover and forest biodiversity at a meaningful scale across the Amazonian biome.     

Intra-specific Variation for Salt Tolerance in Linseed (Linum usitatissimum L.)

Thirty-six accessions of linseed ( Linum usitatissimum L.) were screened for salt tolerance at the seedling stage after 2 weeks growth in solution culture salinized with 150mol m⁻³ NaCL Considerable variation in salt tolerance was observed in this set of germplasm. Two salt-tolerant accessions, T-5(69-S9)B and LS-2 and two salt-sensitive accessions P-70 and Aver-Rer-Seic, selected at the seedling stage, were grown to maturity in sand culture salinized with 0 (control), 70, 140, and 210 mol m⁻³ NaCl. Both the salt-tolerant accessions exceeded the two salt-sensitive accessions in biomass production, seed yield, and yield components, but the accessions did not differ significantly in seed oil content in the salt treatments. The tolerant accessions accumulated greater amounts of Na⁺ in the shoots and less in the roots compared with the salt-sensitive accessions. The shoot K⁺, K: Na ratios, and K⁺ versus Na⁺ selectivity were lower in the salt-tolerant accessions compared with the salt-sensitive accessions; the reverse was true for their roots. Contributions of Na⁺ and Ca²⁺ to osmotic adjustment were much higher in the two salt-tolerant accessions than in the salt-sensitive ones.
It has been established that there is a great deal of variation for salt tolerance in linseed. The degree of salt tolerance of this crop does not vary during ontogeny. The physiological basis of salt tolerance of this species appears to be associated with the inclusion of Na⁺ in the shoots.