Development of a screening method for the indentification of a novelSaccharomyces cerevisiae mutant over-expressingTrichoderma reesei cellobiohydrolase II

In a previous study we showed that the fusion of the cellulose-binding domain (CBD2) fromTrichoderma reesei cellobiohydrolase II to a β-glucosidase (BGL1) enzyme fromSaccharomycopsis fibuligera significantly hindered its expression and secretion inSaccharomyces cerevisiae. This suggests that the possible low secretion of heterologous cellulolytic enzymes inS. cerevisiae could be attributed to the presence of a cellulose-binding domain (CBD) in these enzymes. The aim of this study was to increase the extracellular production of the chimeric CBD2-BGL1 enzyme (designated CBGL1) inS. cerevisiae. To achieve this, CBGL1 was used as a reporter enzyme for screening mutagenisedS. cerevisiae strains with increased ability to secrete CBD-associated enzymes such as cellulolytic enzymes. A mutant strain ofS. cerevisie, WM91-CBGL1, which exhibited up to 200 U L^?1 of total activity, was isolated. Such activity was approximately threefold more than that of the parental host strain. Seventy-five per cent of the activity was detected in the extracellular medium. The mutant strain transformed with theT. resei CBH2 gene produced up to threefold more cellobiohydrolase enzyme than the parental strain, but with 50% of the total activity retained intracellularly. The cellobiohydrolase enzymes from the parent and mutant strains were partially purified and the characteristic properties analysed.     

Quantitative trait loci for IQ and other complex traits: single-nucleotide polymorphism genotyping using pooled DNA and microarrays

Similar to other complex traits, it is likely that many DNA polymorphisms of small effect size [quantitative trait loci (QTLs)] are responsible for the high heritability of intelligence, in addition to many rare monogenic disorders known to contribute to lowered intelligence. We review the current status of approaches to identify QTLs associations for intelligence employing genome-wide strategies using pooled DNA from many individuals and evaluate the innovative approach of microarray analysis to genotype DNA pools for large numbers of single nucleotide polymorphisms.     

A novel numerical optimization algorithm inspired from weed colonization

This paper introduces a novel numerical stochastic optimization algorithm inspired from colonizing weeds. Weeds are plants whose vigorous, invasive habits of growth pose a serious threat to desirable, cultivated plants making them a threat for agriculture. Weeds have shown to be very robust and adaptive to change in environment. Thus, capturing their properties would lead to a powerful optimization algorithm. It is tried to mimic robustness, adaptation and randomness of colonizing weeds in a simple but effective optimizing algorithm designated as Invasive Weed Optimization (IWO). The feasibility, the efficiency and the effectiveness of IWO are tested in details through a set of benchmark multi-dimensional functions, of which global and local minima are known. The reported results are compared with other recent evolutionary-based algorithms: genetic algorithms, memetic algorithms, particle swarm optimization, and shuffled frog leaping. The results are also compared with different versions of simulated annealing — a generic probabilistic meta-algorithm for the global optimization problem — which are simplex simulated annealing, and direct search simulated annealing. Additionally, IWO is employed for finding a solution for an engineering problem, which is optimization and tuning of a robust controller. The experimental results suggest that results from IWO are better than results from other methods. In conclusion, the performance of IWO has a reasonable performance for all the test functions.     

Microsatellite markers for the palaeotropic pioneer tree genus Macaranga (Euphorbiaceae) and their cross‐species transferability

We developed primer sequences for five polymorphic microsatellite loci in the tropical ant‐plant genus Macaranga (Euphorbiaceae). Population genetic parameters were determined on the basis of 30 individuals from each of two Macaranga species in Borneo. Allele numbers per locus ranged from three to 13. Expected and observed heterozygosities ranged from 0.160 to 0.850 and from 0.130 to 0.700, respectively. Four of the five primer pairs cross‐amplify polymorphic PCR products in a wide range of Macaranga species.     

Deceleration time of systolic pulmonary venous flow: a new clinical marker of left atrial pressure and compliance.

The curvilinearity of the atrial pressure-volume curve implies that atrial compliance decreases progressively with increasing left atrial (LA) pressure (LAP). We predicted that reduced LA compliance leads to more rapid deceleration of systolic pulmonary venous (PV) flow. With this rationale, we investigated whether the deceleration time (t dec) of PV systolic flow velocity reflects mean LAP. In eight patients during coronary surgery, before extracorporeal circulation, PV flow by ultrasonic transit time and invasive LAP were recorded during stepwise volume loading. The t dec was calculated using two methods: by drawing a tangent through peak deceleration and by drawing a line from peak systolic flow through the nadir between the systolic and early diastolic flow waves. LA compliance was calculated as the systolic PV flow integral divided by LAP increment. Volume loading increased mean LAP from 11 +/- 3 to 20 +/- 5 mmHg (P < 0.001) (n = 40), reduced LA compliance from 1.16 +/- 0.42 to 0.72 +/- 0.40 ml/mmHg (P < 0.004) (n = 40), and reduced t dec from 320 +/- 50 to 170 +/- 40 ms (P < 0.0005) (n = 40). Mean LAP correlated well with t dec (r = 0.84, P < 0.0005) (n = 40) and LA compliance (r = 0.79, P < 0.0005) (n = 40). Elevated LAP caused a decrease in LA compliance and therefore more rapid deceleration of systolic PV flow. The t dec has potential to become a semiquantitative marker of LAP and an index of LA passive elastic properties.     

Direct vasoactive and vasoprotective properties of anthocyanin-rich extracts.

Reactive oxygen species (ROS) play a critical role in the impairment of nitric oxide-mediated vascular functions and overall pathogenesis associated with cardiovascular disease. Plant pigment anthocyanins are exceptionally potent oxygen radical scavengers that produce beneficial effects in diseases outside the cardiovascular system. We examined for the first time the potential coronary vasoactive and vasoprotective properties of three anthocyanin enhanced extracts prepared from chokeberry (Ck), bilberry (B), or elderberry (E). Coronary arterial rings were isolated from 64 pigs and incubated in sterile tissue culture media overnight for use in one of four separate in vitro isometric force recording studies. Ck and B, but not E, produced dose- and endothelium-dependent vasorelaxation. (%maximal relaxation at 5 mg total anthocyanins per liter: Ck = 68 +/- 11, B = 59 +/- 10). Coronary vascular tone, endothelium-dependent vasorelaxation to A23187, and vasorelaxation to DEA NONOate were not affected by exposure of rings to any extract at 0.05 mg total anthocyanins per liter for 5 or 30 min. Ck extract at 0.05 mg total anthocyanins per liter showed the greatest protection against loss of A23187 relaxation following exposure to ROS from pyrogallol (Ck, % maximal relaxation and -logED50 to A23187, respectively, means +/- SE: Ck alone, 93 +/- 5%, 7.91 +/- 0.1; pyrogallol alone, 76 +/- 7%, 7.46 +/- 0.06; pyrogallol + Ck, 98 +/- 1%, 7.82 +/- 0.06; control: 99 +/- 1%, 7.86 +/- 0.07; P < 0.05 control vs. pyrogallol alone). Neither the extracts nor pyrogallol affected responses to DEA NONOate. Thus anthocyanin-enhanced extracts produce endothelium-dependent relaxation in porcine coronary arteries. Extract concentrations too low to directly alter coronary vascular tone protect coronary arteries from ROS without altering vasorelaxation to endogenous or exogenous NO. These results suggest that such extracts could have significant beneficial effects in vascular disease.     

Enhanced mitochondrial sensitivity to creatine in rats bred for high aerobic capacity.

Qualitative and quantitative measures of mitochondrial function were performed in rats selectively bred 15 generations for intrinsic aerobic high running capacity (HCR; n = 8) or low running capacity (LCR; n=8). As estimated from a speed-ramped treadmill exercise test to exhaustion (15 degrees slope; initial velocity of 10 m/min, increased 1 m/min every 2 min), HCR rats ran 10 times further (2,375+/-80 m) compared with LCR rats (238+/-12 m). Fiber bundles were obtained from the soleus and chemically permeabilized. Respiration was measured 1) in the absence of ADP, 2) in the presence of a submaximally stimulating concentration of ADP (0.1 mM ADP, with and without 20 mM creatine), and 3) in the presence of a maximally stimulating concentration of ADP (2 mM). Although non-ADP-stimulated and maximally ADP-stimulated rates of respiration were 13% higher in HCR compared with LCR, the difference was not statistically significant (P>0.05). Despite a similar rate of respiration in the presence of 0.1 mM ADP, HCR rats demonstrated a higher rate of respiration in the presence of 0.1 mM ADP+20 mM creatine (HCR 33% higher vs. LCR, P<0.05). Thus mitochondria from HCR rats exhibit enhanced mitochondrial sensitivity to creatine (i.e., the ability of creatine to decrease the Km for ADP). We propose that increased respiratory sensitivity to ADP in the presence of creatine can effectively increase muscle sensitivity to ADP during exercise (when creatine is increased) and may be, in part, a contributing factor for the increased running capacity in HCR rats.     

Immobilization of a Mixed Culture of Oxygenic Phototrophic Microorganisms on a Chitosan-Based Sorbent for Nutrient Bioremoval

Applied Biochemistry and Microbiology - The immobilization of cells of a mixed culture of the microalgae (MA) Micractinium sp. NAMSU A-19 and cyanobacteria (CB) Synechococcus sp. 1Dp66E-1 on a...     

Evidence of Toxocara Eggs in Pachycrocuta brevirostris (Gervais, 1850) Coprolites from the Pleistocene of Taurida Cave (Crimea)

Doklady Biological Sciences - Coprolites of the hyena Pachycrocuta brevirostris from the Lower Pleistocene (Upper Villafranchian) of Taurida Cave (Crimea) were studied. One of the three hyena...