<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.     

Some Nutritional Characteristics of Enzymatically Resistant Maltodextrin from Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) Starch

Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min. The resulting resistant maltodextrin contained 24.45% dextrose equivalents, 56.06% indigestible starch and 86.62% dietary fiber. Compared to the cassava native starch, the pyrodextrin exhibited 56% solubility at room temperature and the resistant maltodextrin 100%. The glycemic index value for the resistant maltodextrin was 59% in healthy persons. Its high indigestible starch and dietary fiber contents, as well as its complete solubility, make the resistant maltodextrin a promising ingredient for raising dietary fiber content in a wide range of foods, especially in drinks, dairy products, creams and soups.     

Occupancy pattern of a long-horned beetle in a variegated forest landscape: linkages between tree quality and forest cover across spatial scales

Context

Interactions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quality at different spatial scales.

Objectives

We evaluated the spatial scales at which forest cover and tree quality make the greatest contribution to the occupancy of the long-horned beetle Microplophorus magellanicus (Coleoptera: Cerambycidae) in a variegated forest landscape.

Methods

We used averaged data of tree quality (as derived from remote sensing estimates of the decay stage of single trees) and spatially independent pheromone-baited traps to model the occurrence probability as a function of multiple cross-scale combinations between forest cover and tree quality (with scales ranging between 50 and 400 m).

Results

Model support and performance increased monotonically with the increasing scale at which tree quality was measured. Forest cover was not significant, and did not exhibit scale-specific effects on the occurrence probability of M. magellanicus. The interactive effect between tree quality and forest cover was stronger than the independent (additive) effects of tree quality and particularly forest cover. Significant interactions included tree quality measured at spatial scales ≥200 m, but cross-scale interactions occurred only in four of the seven best-supported models.

Conclusions

M. magellanicus respond to the high-quality trees available in the landscape rather than to the amount of forest per se. Conservation of viable metapopulations of M. magellanicus should consider the quality of trees at spatial scales >200 m.

     

Using operating area size and adjacency constraints to mitigate the effects of harvesting activities on boreal caribou habitat

Context

Sustained timber harvesting conflicts with the long-term viability of boreal caribou (Rangifer tarandus caribou) populations. The spatial arrangement of harvest blocks in the landscape could mitigate the impact of logging on caribou populations. For the forest industry, however, these measures represent constraints that reduce the annual allowable cut (AAC).

Objective

Estimate the long-term impacts of spatial constraints to harvesting, applied alone or in combination, on AAC and boreal caribou populations.

Methods

We divided a 30,000 km² region into 20 harvest block sizes varying from 50 to 1000 km², and modeled the implementation of spatially explicit harvest schedule plans in combination with wildfire and caribou population dynamics. We then evaluated the probability of persistence of boreal caribou populations.

Results

The probability of maintaining an AAC target declined with increasing target AAC, increasing size of operating area, and increasing adjacency constraints. In contrast, the probability of maintaining caribou populations declined with increasing AAC, decreasing size of operating areas, and decreasing adjacency constraints. An increase in operating area size from 50 to 300 km² produced a considerable gain in AAC for all adjacency constraints.

Conclusions

Because adjacency constraints led only to a small increase in the probability of maintaining caribou populations, we recommend adopting less constraining landscape management actions, such as a 70-year period between two consecutive harvests in the same ~300-km² operating area.

     

Conferring resistance to pre-harvest sprouting in durum wheat by a QTL identified in <Emphasis Type="Italic">Triticum spelta</Emphasis>

Pre-harvest sprouting (PHS) causes significant yield loss and degrade the end-use quality of wheat, especially in regions with prolonged wet weather during the harvesting season. Unfortunately, the gene pool of Triticum durum (tetraploid durum wheat) has narrow genetic base for PHS resistance. Therefore, finding out new genetic resources from other wheat species to develop PHS resistance in durum wheat is of importance. A major PHS resistance QTL, Qphs.sicau-3B.1, was mapped on chromosome 3BL in a recombinant inbred line population derived from ‘CSCR6’ (Triticum spelta), a PHS resistant hexaploid wheat and ‘Lang’, a PHS susceptible Australian hexaploid wheat cultivar. This QTL, Qphs.sicau-3B.1, is positioned between DArT marker wPt-3107 and wPt-6785. Two SCAR markers (Ph3B.1 and Ph3B.2) were developed to track this major QTL and were used to assay a BC₂F₈ tetraploid population derived from a cross between the durum wheat ‘Bellaroi’ (PHS susceptible) and ‘CSCR6’ (PHS resistant). Phenotypic assay and marker-assisted selection revealed five stable tetraploid lines were highly PHS resistant. This study has successfully established that PHS-resistance QTL from hexaploid wheat could be efficiently introgressed into tetraploid durum wheat. This tetraploid wheat germplasm could be useful in developing PHS resistant durum cultivars with higher yield and good end-use quality.     

Proteomic profiles during adventitious rooting of Eucalyptus species relevant to the cellulose industry

New Forests - Adventitious rooting (AR) is an obligatory step for vegetative propagation of commercial woody species. Paper industries have interest in Eucalyptus globulus Labill and its hybrids...     

A 3-year assessment of nitrous oxide emission factors for urine and dung of grazing sheep in a subtropical ecosystem

Purpose

Grazing livestock has strong impact on global nitrous oxide (N₂O) emissions by providing N sources through excreta. The scarcity of information on factors influencing N₂O emissions from sheep excreta in subtropical ecosystems such as those of Southern Brazil led us to conduct field trials in three different winter pasture seasons on an integrated crop–livestock system (ICL) in order to assess N₂O emission factors (EF-N₂O) in response to variable rates of urine and dung.

Materials and methods

The equivalent urine-N loading rates for the three winter seasons (2009, 2010, and 2013) ranged from 96 to 478 kg ha^?1, and the dung-N rates applied in 2009 and 2010 were 81 and 76 kg ha^?1, respectively. Air was sampled from closed static chambers (0.20 m in diameter) for approximately 40 days after excreta application and analyzed for N₂O by gas chromatography.

Results and discussion

Soil N₂O-N fluxes spanned the ranges 4 to 353 μg m^?2 h^?1 in 2009, ??47 to 976 μg m^?2 h^?1 in 2010, and 46 to 339 μg m^?2 h^?1 in 2013. Urine addition resulted in N₂O-N peaks within for up to 20–30 days after application in the 3 years, and the strength of the peaks was linearly related to the N rate used. Emission factors of N₂O (EF-N₂O, % of N applied that is emitted as N₂O) of urine ranged from 0.06 to 0.34% and were essentially independent of N rate applied. By considering a ratio of N excreted by urine and dung of 60:40, a single combined excretal EF-N₂O of 0.14% was estimated.

Conclusions

Our findings showed higher mean EF-N₂O for sheep urine than that for dung (0.21% vs 0.03%), irrespective of the occurrence or not of urine patches overlap. This value is much lower than default value of 1% of IPCC’s Tier 1 and reinforces the needs of its revision.

     

Sorbent Materials Characterization Based on Mechanical or Thermal Pretreated Montmorillonite Modified by Surfactant Loading for Improved Chromium Retention

Water, Air, & Soil Pollution - The treatment efficiency of Chlorella sorokiniana and Scenedesmus species, immobilized in sodium alginate, was evaluated for removing nitrate from groundwater....     

The molecular mechanism of thermal noise in rod photoreceptors

Spontaneous electrical signals in the retina's photoreceptors impose a limit on visual sensitivity. Their origin is attributed to a thermal, rather than photochemical, activation of the transduction cascade. Although the mechanism of such a process is under debate, the observation of a relationship between the maximum absorption wavelength (λ(max)) and the thermal activation kinetic constant (k) of different visual pigments (the Barlow correlation) indicates that the thermal and photochemical activations are related. Here we show that a quantum chemical model of the bovine rod pigment provides a molecular-level understanding of the Barlow correlation. The transition state mediating thermal activation has the same electronic structure as the photoreceptor excited state, thus creating a direct link between λ(max) and k. Such a link appears to be the manifestation of intrinsic chromophore features associated with the existence of a conical intersection between its ground and excited states.