Mapping loci for chlorosis associated with chlorophyII b deficiency in potato

About 30% of the potato plants from a (Solanum tuberosum × S. berthaultii) × S. tuberosum backcross population had chlorotic, malformed leaves; but a gradation in symptom severity suggested regulation by more than one gene. The study was undertaken to determine whether this was the case, whether any genes previously reported to control chlorosis in potato were involved, and to see how symptoms were related to effects on chlorophyll content. Testing for quantitative trait loci indicated major control by a single recessive gene on chromosome 1, close to one or more loci that have been reported to produce chlorosis in tomato, but distinct from similar genes previously identified in potato. The proposed symbol for the potato gene that confers phenotype with chlorotic and malformed leaves is cml (chlorotic and malformed leaves). The effects of this gene appeared to be accentuated by a second gene, located on chromosome 12. Chlorotic plants showed a 50% decrease in chlorophyll b level in the affected parts of leaves. It is concluded that cml is different from previously reported genes for chlorosis in potato, that at least one other gene modifies the intensity of symptom expression, and that the observed chlorosis is produced through effects on chlorophyll b level

EFFECTS OF ENERGY DEVELOPMENT ON AGRICULTURAL LAND VALUES

This paper uses multiple regression analysis to examine the effects of energy resource development on sale prices of agricultural land in western North Dakota. The findings suggest that energy resources development has exerted only modest upward pressure on agricultural land values in the northern Great Plains. The land market in this region remains dominated by active farmers who are purchasing farmland as a long-term investment, and energy development has not had a major impact on the structure of that market.Land Economics/Use, Resource /Energy Economics and Policy,

Is CT-based body composition associated with long-term chemotherapy-induced peripheral neuropathy in colorectal cancer survivors?

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect among colorectal cancer (CRC) survivors, and the severity is mainly dependent on the chemotherapy dose. Nowadays, chemotherapy dose is based on body surface area, while determination based on more accurate measures of body composition may be better. This study aimed to investigate the association between body composition and long-term CIPN among CRC survivors 2–11 years after diagnosis. METHODS: Data from CRC survivors from the population-based PROFILES registry were used. Survivors were included when they received chemotherapy, filled in the EORTC QLQ-CIPN20, and had a computed tomography (CT) scan at diagnosis (n = 202). Total, sensory, motor, and autonomic CIPN were based upon the EORTC QLQ-CIPN20. The abdominal CT scans were used to determine skeletal muscle index (SMI), skeletal muscle density (SMD), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT). Logistic regression was used to analyze the association between CIPN outcomes and body composition variables. RESULTS: CIPN was experienced by 64% of the CRC survivors several years after chemotherapy. More SAT was associated with a higher odds of reporting total CIPN (OR = 1.01 95% CI 1.00–1.01, p = 0.01), motor CIPN (OR = 1.01 95% CI 1.00–1.01, p = 0.01), and sensory CIPN (OR = 1.01 95% CI 1.00–1.01, p = 0.04). No associations of other body composition parameters with CIPN were observed. CONCLUSION: Only SAT was associated with total, motor, and sensory CIPN. Based on these results, we cannot conclude that determining the chemotherapy dose based on body composition is preferred over determining the chemotherapy dose based on body surface to prevent CIPN. More research is needed to assess associations of body composition with CIPN, a common side effect of chemotherapy

High-Frequency network activity, global increase in Neuronal Activity, and Synchrony Expansion Precede Epileptic Seizures In Vitro

How seizures start is a major question in epilepsy research. Preictal EEG changes occur in both human patients and animal models, but their underlying mechanisms and relationship with seizure initiation remain unknown. Here we demonstrate the existence, in the hippocampal CA1 region, of a preictal state characterized by the progressive and global increase in neuronal activity associated with a widespread buildup of low-amplitude high-frequency activity (HFA) (100 Hz) and reduction in system complexity.HFAis generated by the firing of neurons, mainly pyramidal cells, at much lower frequencies. Individual cycles ofHFAare generated by the near-synchronous (within 5 ms) firing of small numbers of pyramidal cells. The presence of HFA in the low-calcium model implicates nonsynaptic synchronization; the presence of very similar HFA in the high-potassium model shows that it does not depend on an absence of synaptic transmission. Immediately before seizure onset, CA1 is in a state of high sensitivity in which weak depolarizing or synchronizing perturbations can trigger seizures. Transition to seizure is haracterized by a rapid expansion and fusion of the neuronal populations responsible for HFA, associated with a progressive slowing of HFA, leading to a single, massive, hypersynchronous cluster generating the high-amplitude low-frequency activity of the seizure

Exploring metabolic engineering design principles for the photosynthetic production of lactic acid by Synechocystis sp. PCC6803

Background: Molecular engineering of the intermediary physiology of cyanobacteria has become important for the sustainable production of biofuels and commodity compounds from CO2 and sunlight by "designer microbes." The chemical commodity product L-lactic acid can be synthesized in one step from a key intermediary metabolite of these organisms, pyruvate, catalyzed by a lactate dehydrogenase. Synthetic biology engineering to make "designer microbes" includes the introduction and overexpression of the product-forming biochemical pathway. For further optimization of product formation, modifications in the surrounding biochemical network of intermediary metabolism have to be made. Results: To improve light-driven L-lactic acid production from CO2, we explored several metabolic engineering design principles, using a previously engineered L-lactic acid producing mutant strain of Synechocystis sp. PCC6803 as the benchmark. These strategies included: (i) increasing the expression level of the relevant product-forming enzyme, lactate dehydrogenase (LDH), for example, via expression from a replicative plasmid; (ii) co-expression of a heterologous pyruvate kinase to increase the flux towards pyruvate; and (iii) knockdown of phosphoenolpyruvate carboxylase to decrease the flux through a competing pathway (from phosphoenolpyruvate to oxaloacetate). In addition, we tested selected lactate dehydrogenases, some of which were further optimized through site-directed mutagenesis to improve the enzyme’s affinity for the co-factor nicotinamide adenine dinucleotide phosphate (NADPH). The carbon partitioning between biomass and lactic acid was increased from about 5% to over 50% by strain optimization. Conclusion: An efficient photosynthetic microbial cell factory will display a high rate and extent of conversion of substrate (CO2) into product (here: L-lactic acid). In the existing CO2-based cyanobacterial cell factories that have been described in the literature, by far most of the control over product formation resides in the genetically introduced fermentative pathway. Here we show that a strong promoter, in combination with increased gene expression, can take away a significant part of the control of this step in lactic acid production from CO2. Under these premises, modulation of the intracellular precursor, pyruvate, can significantly increase productivity. Additionally, production enhancement is achieved by protein engineering to increase co-factor specificity of the heterologously expressed LDH

Understanding the experience of social housing pathways

This report is part of an Australian Housing and Urban Research Institute (AHURI) Inquiry examining how social housing pathways could be reimagined to provide more effective assistance for low-income households in Australia. This research sets out to understand the ways in which individuals and households experience pathways into, within and out of the Australian social housing system

Anxiety and depression mediate the association between chemotherapy-induced peripheral neuropathy and fatigue:Results from the population-based PROFILES registry

Objective Chemotherapy‐induced sensory peripheral neuropathy (CIPN) is common among colorectal cancer (CRC) survivors. The aim of this study was to examine whether CIPN is associated with both psychological distress (ie, anxiety and depression) and fatigue and whether the relationship between CIPN and fatigue can (partly) be explained by psychological distress. Methods All CRC survivors diagnosed between 2000 and 2009 as registered by the population‐based Netherlands Cancer Registry (Eindhoven region) were eligible for participation. Chemotherapy‐treated survivors completed questions on CIPN (EORTC QLQ‐CIPN20), psychological distress (HADS), and fatigue (FAS) on average 5.6 years after diagnosis. Simple and multiple mediation analyses were performed to examine anxiety and depression as possible mediators in the association between CIPN and fatigue. Results Survivors with high (ie, upper 30% of scores) CIPN (n = 172) reported more anxiety and depressive symptoms and more fatigue compared with those with low CIPN (n = 299). Furthermore, among survivors with high CIPN, those who were anxious, depressed, or both reported more fatigue compared with those without psychological distress. These differences were clinically relevant. Finally, mediation analyses showed that while CIPN was directly associated with fatigue, the relationship between CIPN and fatigue was also significantly mediated by both anxiety and depression. Conclusions CRC survivors with high CIPN report more fatigue, especially those who are also anxious and/or depressed. More research is needed on the direction of the relationship between CIPN, psychological distress, and fatigue. For now, the treatment of fatigue should also focus on addressing psychological distress, as treating fatigue alone might not be sufficient

Sociodemographic, clinical, lifestyle, and psychological correlates of peripheral neuropathy among 2- to 12-year colorectal cancer survivors

Background Peripheral neuropathy (PN) is a debilitating complication among colorectal cancer (CRC) survivors that can become chronic. No large-scale study has yet analyzed correlates in multivariable models. We did multivariable analyses to find correlates of PN. Methods In 1,516 all-stage Dutch CRC survivors, cross-sectional data were collected on sensory, motor, autonomic and total PN, sociodemographic (age, sex, education, employment, partner), clinical (time since diagnosis, tumor location, stage, chemotherapy, radiotherapy, co-morbidities), lifestyle (alcohol, smoking, physical activity, body mass index), psychological factors (anxiety, depression, personality) and health-related quality of life (HRQoL). After multiple imputation, correlates were analyzed with linear regressions and eliminated with backwards selection. Results CRC survivors (69 years; 42% female) were on average five years post-diagnosis, and 28-65% reported PN. PN was associated with older age, being male (sensory) or female (motor), shorter time since diagnosis, chemotherapy, co-morbidities, anxiety, depression, and worse scores on HRQoL domains, and pain, nausea, vomiting, insomnia, constipation and financial problems. Conclusions In multivariable analyses, PN is affected by receiving chemotherapy, aging, sex, co-morbidities, stress-related factors and HRQoL in CRC survivors. Future PN-related studies can include these factors, and they can be examined in longitudinal studies to gain more knowledge about chronicity and severity of PN

О некоторых тенденциях, осложнивших в начале ХХI века перспективы курортно-рекреационного развития Крыма

Целью работы явился анализ взаимовлияния различных факторов, сужающих потенциал туристско-рекреационной привлекательности Крыма, для уточнения возможностей объективного прогнозирования его перспективного развития