Some significant differences in wall chemistry among four commercial Agaricus bisporus strains

Significant differences in gross wall chemical composition were detected in four commercial Agaricus bisporus strains. All were grown under the same conditions and their walls prepared by a mild method of breakage. A more detailed analysis of the wall fractions, isolated by means of their distinct solubilities, also showed striking structural differences among the four strains studied. The detected differences, not only in the overall composition of the wall but also in the polysaccharide structure, could assist in the characterization of strains and/or varieties of the commercial basidiomycete A. bisporus.     

The influence of ionic composition on the distribution of nematode species in springs of the province of Granada (Spain)

The ionic composition of 38 mineral springs in the province of Granada (Spain), and the distribution of 45 species of nematodes belonging to orders Monhysterida, Araeolaimida, Chromadorida and Enoplida were examined. Water chemistry is used to make two diagrams representing anionic and cationic composition. Diagrams for anionic composition (given the greater variance seen in the springs considered) are used to illustrate the distribution of individual species. The results obtained from species distribution and the correlation between species made it possible to group species which could be associated with springs where each of the anions considered predominated. A greater number of species groups was found to inhabit springs in which chloride concentrations was less than 50% of the total concentration of anions.     

SODIUM: SOME EFFECTS ON BLUEGREEN ALGAL GROWTH1

The growth of heterocystous bluegreen algae in various concentrations of sodium, was examined in axenic culture as well as in situ studies. Anabaena cylindrica Lemm. with no Na⁺ added, suffered from decreased rates of acetylene reduction, ¹⁴C, assimilation, excretion of organic C as well as lower concentrations of chlorophyll a and particulate organic C compared to cultures supplied with 5, 10, and 50 mg Na⁺·l⁻¹ Sodium deficient algae released, extracellularly a higher percentage of previously fixed C as organic C. No differences in any parameter measured were demonstrable among cultures grown with 5, 10, and 50 mg Na⁺·l⁻¹ High nitrate concentrations (20 mg NO₃⁻·l⁻¹) resulted in decreased rates of acetylene reduction and heterocyst numbers in. Na sufficient, and Na deficient cultures: however, decreased, cellular Na content at high NO₃⁻ levels occurred only in N deficient, cultures. Higher percentages of excreted organic C occurred with increasing NO₃⁻ concentrations in Na deficient cultures. Sodium enrichment of natural bluegreen populations with the addition of 50, 100, and 200 mg Na⁺·l⁻¹ elicited neither a stimulatory nor an inhibitory response in photosynthetic C fixation. In contrast, the addition of small amounts of Na⁺ (5 mg·l⁻) resulted in increased C fixation. However, since the Na. concentration of the lake water, at ca. 5 mg Na⁺·l⁻¹, was sufficient for growth of the bluegreens present, sodium, is not assumed to be limiting under most natural conditions. No increase in in situ acetylene reduction rates occurred with additions of sodium.     

Norditerpene dilactones from Podocarpus saligna

Rimuene and nubigenol have been identified in Podocarpus saligna for the first time, and the structures of three new norditerpene dilactones, salignones K, L and M, isolated from this species have been elucidated.     

Pontine A5 region modulation of the cardiorespiratory response evoked from the midbrain dorsolateral periaqueductal grey

Journal of Physiology and Biochemistry - Connections between the midbrain dorsolateral periaqueductal grey (dlPAG) and the pontine A5 region have been shown. The stimulation of both regions evokes...     

Control of (Multi)Drug Resistance and Tuberculosis Incidence over 23 Years in the Context of a Well-Supported Tuberculosis Programme in Rural Malawi

Background

The rise in tuberculosis (TB) incidence following generalized HIV epidemics can overwhelm TB control programmes in resource-limited settings, sometimes accompanied by rising rates of drug resistance. This has led to claims that DOTS-based TB control has failed in such settings. However, few studies have described the effect of a sustained and well-supported DOTS programme on TB incidence and drug resistance over a long period. We present long-term trends in incidence and drug resistance in rural Malawi.

Methods

Karonga District in northern Malawi has an adult HIV prevalence of ∼10%. A research group, the Karonga Prevention Study, collaborates with the National Tuberculosis Programme to support core TB control activities. Bacteriological, demographic and clinical (including HIV status) information from all patients starting TB treatment in the District have been recorded since 1988. During that period isolates from each culture-positive TB patient were exported for drug sensitivity testing. Antiretroviral therapy (ART) has been widely available since 2005.

Results

Incidence of new smear-positive adult TB peaked at 124/100,000/year in the mid-90s, but has since fallen to 87/100,000/year. Drug sensitivity information was available for 95% (3132/3307) of all culture-positive cases. Initial resistance to isoniazid was around 6% with no evidence of an increase. Fewer than 1% of episodes involved a multi-drug resistant strain.

Discussion

In this setting with a generalised HIV epidemic and medium TB burden, a well-supported DOTS programme enhanced by routine culture and drug sensitivity testing may well have reduced TB incidence and maintained drug resistance at low levels.     

Disability Affects the 6-Minute Walking Distance in Obese Subjects (BMI>40 kg/m2)

Introduction

In obese subjects, the relative reduction of the skeletal muscle strength, the reduced cardio-pulmonary capacity and tolerance to effort, the higher metabolic costs and, therefore, the increased inefficiency of gait together with the increased prevalence of co-morbid conditions might interfere with walking. Performance tests, such as the six-minute walking test (6MWT), can unveil the limitations in cardio-respiratory and motor functions underlying the obesity-related disability. Therefore the aims of the present study were: to explore the determinants of the 6-minute walking distance (6MWD) and to investigate the predictors of interruption of the walk test in obese subjects.

Methods

Obese patients [body mass index (BMI)>40 kg/m²] were recruited from January 2009 to December 2011. Anthropometry, body composition, specific questionnaire for Obesity-related Disabilities (TSD-OC test), fitness status and 6MWT data were evaluated. The correlation between the 6MWD and the potential independent variables (anthropometric parameters, body composition, muscle strength, flexibility and disability) were analysed. The variables which were singularly correlated with the response variable were included in a multivariated regression model. Finally, the correlation between nutritional and functional parameters and test interruption was investigated.

Results

354 subjects (87 males, mean age 48.5±14 years, 267 females, mean age 49.8±15 years) were enrolled in the study. Age, weight, height, BMI, fat mass and fat free mass indexes, handgrip strength and disability were significantly correlated with the 6MWD and considered in the multivariate analysis. The determination coefficient of the regression analysis ranged from 0.21 to 0.47 for the different models. Body weight, BMI, waist circumference, TSD-OC test score and flexibility were found to be predictors of the 6MWT interruption.

Discussion

The present study demonstrated the impact of disability in obese subjects, together with age, anthropometric data, body composition and strength, on the 6-minute walking distance.     

Estimation of Parameters Influencing Waterborne Transmission of Infectious Hematopoietic Necrosis Virus (IHNV) in Atlantic Salmon (Salmo salar)

Understanding how pathogenic organisms spread in the environment is crucial for the management of disease, yet knowledge of propagule dispersal and transmission in aquatic environments is limited. We conducted empirical studies using the aquatic virus, infectious hematopoietic necrosis virus (IHNV), to quantify infectious dose, shedding capacity, and virus destruction rates in order to better understand the transmission of IHN virus among Atlantic salmon marine net-pen aquaculture. Transmission of virus and subsequent mortality in Atlantic salmon post-smolts was initiated with as low as 10 plaque forming units (pfu) ml⁻¹. Virus shedding from IHNV infected Atlantic salmon was detected before the onset of visible signs of disease with peak shed rates averaging 3.2×10⁷ pfu fish⁻¹ hour⁻¹ one to two days prior to mortality. Once shed into the marine environment, the abundance of free IHNV is modulated by sunlight (UV A and B) and the growth of natural biota present in the seawater. Virus decayed very slowly in sterilized seawater while rates as high as k =  4.37 d⁻¹ were observed in natural seawater. Decay rates were further accelerated when exposed to sunlight with virus infectivity reduced by six orders of magnitude within 3 hours of full sunlight exposure. Coupling the IHNV transmission parameter estimates determined here with physical water circulation models, will increase the understanding of IHNV dispersal and provide accurate geospatial predictions of risk for IHNV transmission from marine salmon sites.     

Phytoextraction of high value elements and contaminants from mining and mineral wastes: opportunities and limitations

Plant and Soil - Phytoextraction is an in situ technique that can be applied to minerals and mining wastes using hyperaccumulator plants to purposely bio-concentrate high levels of metals or...     

Rice yield formation under high day and night temperatures—A prerequisite to ensure future food security

Increasing temperatures resulting from climate change dramatically impact rice crop production in Asia. Depending on the specific stage of rice development, heat stress reduces tiller/panicle number, decreases grain number per plant and lower grain weight, thus negatively impacting yield formation. Hence improving rice crop tolerance to heat stress in terms of sustaining yield stability under high day temperature (HDT), high night temperature (HNT), or combined high day and night temperature (HDNT) will bolster future food security. In this review article, we highlight the phenological alterations caused by heat and the underlying molecular-physiological and genetic mechanisms operating under different types of heat conditions (HDT, HNT, and HDNT) to understand heat tolerance. Based on our synthesis of HDT, HNT, and HDNT effects on rice yield components, we outline future breeding strategies to contribute to sustained food security under climate change.