Association with pedogenic iron and aluminum: effects on soil organic carbon storage and stability in four temperate forest soils

Soil organic carbon (SOC) can be stabilized via association with iron (Fe) and aluminum (Al) minerals. Fe and Al can be strong predictors of SOC storage and turnover in soils with relatively high extractable metals content and moderately acidic to circumneutral pH. Here we test whether pedogenic Fe and Al influence SOC content and turnover in soils with low Fe and Al content and acidic pH. In soils from four sites spanning three soil orders, we quantified the amount of Fe and Al in operationally-defined poorly crystalline and organically-complexed phases using selective chemical dissolution applied to the soil fraction containing mineral-associated carbon. We evaluated the correlations of Fe and Al concentrations, mean annual precipitation (MAP), mean annual temperature (MAT), and pH with SOC content and ¹⁴C-based turnover times. We found that poorly crystalline Fe and Al content predicted SOC turnover times (p < 0.0001) consistent with findings of previous studies, while organically-complexed Fe and Al content was a better predictor of SOC concentration (p < 0.0001). Greater site-level MAP (p < 0.0001) and colder site-level MAT (p < 0.0001) were correlated with longer SOC turnover times but were not correlated with SOC content. Our results suggest that poorly crystalline Fe and Al effectively slow the turnover of SOC in these acidic soils, even when their combined content in the soil is less than 2% by mass. However, in the strongly acidic Spodosol, organo-metal complexes tended to be less stable resulting in a more actively cycling mineral-associated SOC pool.     

Transgenic tobacco plants having a higher level of methionine are more sensitive to oxidative stress

Methionine is an essential amino acid the low level of which limits the nutritional quality of plants. We formerly produced transgenic tobacco (Nicotiana tabacum) plants overexpressing CYSTATHIONE γ‐SYNTHASE (CGS) (FA plants), methionine's main regulatory enzyme. These plants accumulate significantly higher levels of methionine compared with wild‐type (WT) plants. The aim of this study was to gain more knowledge about the effect of higher methionine content on the metabolic profile of vegetative tissue and on the morphological and physiological phenotypes. FA plants exhibit slightly reduced growth, and metabolic profiling analysis shows that they have higher contents of stress‐related metabolites. Despite this, FA plants were more sensitive to short‐ and long‐term oxidative stresses. In addition, compared with WT plants and transgenic plants expressing an empty vector, the primary metabolic profile of FA was altered less during oxidative stress. Based on morphological and metabolic phenotypes, we strongly proposed that FA plants having higher levels of methionine suffer from stress under non‐stress conditions. This might be one of the reasons for their lesser ability to cope with oxidative stress when it appeared. The observation that their metabolic profiling is much less responsive to stress compared with control plants indicates that the delta changes in metabolite contents between non‐stress and stress conditions is important for enabling the plants to cope with stress conditions.     

An overview of the South Korean edible insect food industry: challenges and future pricing/promotion strategies

The purpose of this paper is to provide an overview of the edible insect industry in South Korea and present suggestions for future pricing and promotion strategies. In the first section of this paper, this study outlines the current status and challenges of the edible insect industry in the food market, the material market, the animal feed market, and the medicinal market. The second section of this paper suggests different pricing and promotion strategies for each market segment. This study describes how the consideration of personal traits, information framing, and increasing familiarity can enhance consumer consumption of insect‐based foods.     

Evolutional Genetics and Diseases of Civilization

Inclination for hyperinsulinemia that was formed in the human population at early stages of development and was fixed genetically in the process of evolution is suggested to underlie pathogenesis of the currently most widely spread diseases of the cardiovascular system (atherosclerosis and hypertension) as well as diabetes mellitus of the 2 type and obesity that are concomitant with a high frequency. Under conditions of civilization, chronic hyperinsulinemia can develop in response to the regularly excessive nutrition. The consequence of the excessive food consumption and the chronic hyperinsulinemia can be overcrowding with lipids (triglycerides) of adipose tissue—the organism lipid store. The natural protective reaction of the cell that contains the limitedly possible amount of lipids is a decrease of the number of insulin receptors and development of insulin resistance. The insulin resistance, in turn, provides the appearance of hyper- and dislipoproteinemia alongside with hyperglycemia. One of the most clinically significant ways of achievement of homeostasis is storage of lipids in the arterial wall. Atherogenic and other concomitant metabolic disorders, specifically changes of blood coagulation properties providing susceptibility to hypercoagulation, affect the blood rheological properties and seem to lead to pathology of the entire vascular system: chronic venous insufficiency, disturbance of microcirculation, and arterial atherosclerosis. There is substantiated the natural interconnection of atherosclerosis, type 2 diabetes, obesity, and arterial hypertension that at present are accepted as the main clinical manifestations of the so-called “metabolic syndrome.” It is suggested that the basis for arterial hypertension might be disturbances of microcirculation leading to an increase of peripheral vascular resistance as well as insufficiency of renal blood supply at the level of arterial and microcirculatory bed.__________Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 2, 2005, pp. 186–191.Original Russian Text Copyright © 2005 by Liberman.     

Virulence and pathogenicity patterns of Trypanosoma brucei gambiense field isolates in experimentally infected mouse: differences in host immune response modulation by secretome and proteomics

Human African trypanosomiasis is characterised by an important clinical diversity. Although Trypanosoma brucei gambiense field stocks isolated from patients in the same focus did not exhibit apparent genetic variability, they showed marked differences in terms of virulence (capacity to multiply inside a host) and pathogenicity (ability of producing mortality) in experimental murine infections. Two strains exhibiting opposite pathogenic and virulence properties in mouse were further investigated through their host-parasite interactions. In vitro, parasite bloodstream forms or soluble factors (or secretome) from both strains induced macrophage arginase as a function of their virulence. Arginase expression, a hallmark of macrophage alternative activation pathway, favours trypanosome bloodstream forms development. Moreover, a comparative proteomic study of the trypanosome stocks' secretomes evidenced both a differential expression of common molecules and the existence of stock specific molecules. This highlighted the potential involvement of the differential expression of the same genome in the diverse infectious properties of trypanosomes.     

siRNA as a tool for investigating organogenesis: The pitfalls and the promises

Removing the function of a specific gene from a developing organ, by making a ‘knockout’ mouse, is a powerful method for analyzing the molecular pathways that control organogenesis. The technique is expensive, though, in terms of time and money, and complex strategies for producing conditional knockouts are needed for genes that are essential for early development of the embryo, for which an unconditional knockout would be lethal before the organ of interest begins to form. Small interfering RNAs (siRNAs) offer a method of knocking down the expression of specific genes with no need for genomic manipulation. Almost as soon as they had been discovered, siRNAs began to be used to explore the molecular biology of mammalian cells in conventional, two-dimensional culture. They have now also been applied successfully, by several groups, to knock down specific genes in various organ rudiments developing in organ culture. This article reviews the basic technique of siRNA-mediated gene knockdown and how it is being applied to organ culture. It also reviews some of the current problems and challenges in the field, and the ways in which these problems are likely to be overcome.Key words: siRNA, RNAi, organ culture, organogenesis, organ development, 3D culture     

Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis

Background

Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters.

Methods

We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios.

Results

We identified 74 studies of pre-eclampsia (total 79 547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients.

Interpretation

Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.Pre-eclampsia and intrauterine growth restriction remain important causes of maternal and perinatal morbidity and mortality.^1–3 Maternal complications of pre-eclampsia include coagulopathy, renal and liver failure, and stroke.¹ Adults who were affected by intrauterine growth restriction in utero are at increased risk for cardiovascular disease, hypertension and type 2 diabetes.^4,5Pre-eclampsia and intrauterine growth restriction are characterized by abnormal placenta formation,⁶ which results in inadequate uteroplacental blood flow. This has led to the idea of using Doppler ultrasonography to assess the velocity of uterine artery blood flow as part of routine ultrasound screening.⁷ Low end-diastolic velocities and an early diastolic notch characterize the waveforms of uterine artery blood flow in women who are not pregnant or are in their first trimester. Persistence of a diastolic notch (beyond 24 weeks'' gestation) or abnormal flow velocity ratios have been associated with inadequate trophoblast invasion.⁸Accurate prediction of pre-eclampsia and intrauterine growth restriction is crucial to allow judicious allocation of resources for monitoring and preventive treatment to improve maternal and perinatal outcomes.^9,10 However, studies investigating the predictive accuracy of uterine artery Doppler indices (Box 1) have revealed considerably varied results. Thus, it is questionable whether uterine artery Doppler ultrasonography should be used as a predictive test. We undertook this review to investigate the accuracy of all uterine artery Doppler indices in predicting pre-eclampsia and intrauterine growth restriction.Open in a separate windowBox 1