Flux Analysis of Glucose Metabolism in Rhizopus oryzae for the Purpose of Increasing Lactate Yields

A flux analysis of glucose metabolism in the filamentous fungus Rhizopus oryzae was achieved using a specific radioactivity curve-matching program, TFLUX. Glycolytic and tricarboxylic acid cycle intermediates labeled through the addition of extracellular [U-14C]glucose were isolated and purified for specific radioactivity determinations. This information, together with pool sizes and the rates of glucose utilization and end product production, provided input for flux maps of the metabolic network under two different experimental conditions. Based upon the flux analysis of this system, a mutant of R. oryzae with higher lactate and lower ethanol yields than the parent was sought for and found.     

Does function follow form? Principal QTLs for Fusarium head blight (FHB) resistance are coincident with QTLs for inflorescence traits and plant height in a doubled-haploid population of barley

Fusarium head blight (FHB), an important disease of barley in many areas of the world, causes losses in grain yield and quality. Deoxynivalenol (DON) mycotoxin residues, produced by the primary pathogen Fusarium graminearum, pose potential health risks. Barley producers may not be able to profitably market FHB-infected barley, even though it has a low DON level. Three types of FHB resistance have been described in wheat: Type I (penetration), Type II (spread), and Type III (mycotoxin degradation). We describe putative measures of these three types of resistance in barley. In wheat, the three resistance mechanisms show quantitative inheritance. Accordingly, to study FHB resistance in barley, we used quantitative trait locus (QTL) mapping to determine the number, genome location, and effects of QTLs associated with Type-I and -II resistance and the concentration of DON in the grain. We also mapped QTLs for plant height, heading date, and morphological attributes of the inflorescence (seeds per inflorescence, inflorescence density, and lateral floret size). QTL analyses were based on a mapping population of F₁-derived doubled-haploid (DH) lines from the cross of the two-rowed genotypes Gobernadora and CMB643, a linkage map constructed with RFLP marker loci, and field evaluations of the three types of FHB resistance performed in China, Mexico, and two environments in North Dakota, USA. Resistance QTLs were detected in six of the seven linkage groups. Alternate favorable alleles were found at the same loci when different inoculation techniques were used to measure Type-I resistance. The largest-effect resistance QTL (for Type-II resistance) was mapped in the centromeric region of chromosome 2. All but two of the resistance QTLs coincided with QTLs determining morphological attributes of the inflorescence and/or plant height. Additional experiments are needed to determine if these coincident QTLs are due to linkage or pleiotropy and to more clearly define the biological basis of the FHB resistance QTLs. Plant architecture should be considered in FHB resistance breeding efforts, particularly those directed at resistance QTL introgression and/or pyramiding. Received: 22 November 1998 / Accepted: 2 June 1999     

Correction of statistical miscalculation slightly alters conclusions about diversity effects for Douglass et al. (2008)

While most of the conclusions about diversity effects in Douglass, J.G., Duffy, J.E. & Bruno, J.F. [Ecol. Lett., 11, 2008, 1] are upheld, correction of a statistical miscalculation indicates that grazer diversity and predator diversity had combined effects on responses, but did not have interactive effects as initially reported.     

Species distribution and <Emphasis Type="Italic">in vitro</Emphasis> antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis

Background  

In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis.     

Influence of weather on reproductive success of northern fulmars in the Canadian high Arctic

The northern fulmar (Fulmarus glacialis) is a common seabird of the North Atlantic Ocean, with breeding colonies broadly dispersed between 45°N and 80°N. At higher latitudes, breeding fulmars experience extensive sea-ice and presumably snow and low temperatures which do not affect fulmars in the southern part of the breeding range. We studied the relationship between weather and reproductive success of northern fulmars breeding at two colonies in the Canadian high Arctic. Collectively, hatching success, fledging success, and productivity (chicks fledged per egg laid) were similar between our study and results from colonies located south of the Arctic. However, a larger proportion of fulmars at apparently occupied sites (AOS) in high Arctic colonies appeared to forego egg-laying, resulting in lower proportions of chicks fledged per AOS. Extreme inclement weather was the major factor influencing nesting success, resulting in pulses of egg or chick loss during or immediately following major storms, although the mechanism of effects appeared to differ between the two colonies. For Arctic fulmars, the risks of nest failure due to stochastic, deleterious weather events may be offset by the predictable abundance of food supplies during chick-rearing in Arctic waters.     

Proof-of-concept human laboratory study for protracted abstinence in alcohol dependence: effects of gabapentin

There is a need for safe medications that can effectively support recovery by treating symptoms of protracted abstinence that may precipitate relapse in alcoholics, e.g. craving and disturbances in sleep and mood. This proof-of-concept study reports on the effectiveness of gabapentin 1200 mg for attenuating these symptoms in a non-treatment-seeking sample of cue-reactive, alcohol-dependent individuals. Subjects were 33 paid volunteers with current Diagnostic and Statistical Manual of Mental Disorders-IV alcohol dependence and a strength of craving rating 1 SD or greater for alcohol than water cues. Subjects were randomly assigned to gabapentin or placebo for 1 week and then participated in a within-subjects trial where each was exposed to standardized sets of pleasant, neutral and unpleasant visual stimuli followed by alcohol or water cues. Gabapentin was associated with significantly greater reductions than placebo on several measures of subjective craving for alcohol as well as for affectively evoked craving. Gabapentin was also associated with significant improvement on several measures of sleep quality. Side effects were minimal, and gabapentin effects were not found to resemble any major classes of abused drugs. Results suggest that gabapentin may be effective for treating the protracted abstinence phase in alcohol dependence and that a randomized clinical trial would be an appropriate next step. The study also suggests the value of cue-reactivity studies as proof-of-concept screens for potential antirelapse drugs.