Sibling correlation of deficit syndrome in the Irish study of high-density schizophrenia families

The deficit syndrome is a subtype of schizophrenia characterized by primary and enduring negative features of psychopathology. It appears to reflect a distinct subtype within the syndrome of schizophrenia. Little is known about the familial or genetic aspects of the deficit syndrome. The purpose of this study was to determine whether deficit versus nondeficit subtypes are correlated in sibling pairs affected with schizophrenia.

Plasma cortisol levels and illness appraisal in deficit syndrome schizophrenia

Research investigating the association between negative symptoms and plasma cortisol levels in individuals with schizophrenia has produced inconsistent findings. This study investigated whether deficit syndrome schizophrenia (characterized by high levels of primary negative symptoms) is associated with comparatively high morning plasma cortisol levels, more negative appraisals about illness and higher levels of depression. Participants were 85 individuals diagnosed with schizophrenia and 85 individuals with no history of contact with psychiatric services matched for age and gender. All participants provided fasting 9.00 a.m. plasma cortisol samples. There were no significant differences between the schizophrenia and control participants in plasma cortisol levels. The Proximal Deficit Syndrome method was used to identify individuals with deficit syndrome schizophrenia. Contrary to what had been hypothesized, participants with deficit syndrome schizophrenia had significantly lower plasma cortisol levels than both non-deficit syndrome participants and control participants. Participants with the deficit syndrome reported significantly less negative appraisals about illness (assessed by PBIQ) and lower levels of depression (assessed by BDI-II). Differences in cortisol levels continued to trend toward significance when levels of depression were controlled for. The patterns of illness-related appraisals and plasma cortisol levels raise the possibility that the deficit syndrome could be a form of adaptation syndrome.

The impacts of management reform on irrigation water use efficiency in the Guanzhong plain, China

This paper examines the efficiency of the 1998 irrigation management reform in the Guanzhong Plain, Shaanxi, China, at farm and canal level. Stochastic frontier analysis is applied to estimate irrigation water use efficiency, based on panel data for 800 farmers, spread over 80 irrigation canals, for the period 1999–2005. Analysis of determinants of water use efficiency shows that at farm level, water price and disclosure are important factors. Compared to the base case of unreformed, management reform has a positive impact with water user association having the largest effect, followed by joint-stock co-operative and private company. The canal model is in line with the farm level model, although estimates are less significant.

Technical and allocative efficiency of irrigation water use in the Guanzhong Plain, China

Due to increasing water scarcity, accelerating industrialization and urbanization, efficiency of irrigation water use in Northern China needs urgent improvement. Based on a sample of 347 wheat growers in the Guanzhong Plain, this paper simultaneously estimates a production function, and its corresponding first-order conditions for cost minimization, to analyze efficiency of irrigation water use. The main findings are that average technical, allocative, and overall economic efficiency are 0.35, 0.86 and 0.80, respectively. In a second stage analysis, we find that farmers’ perception of water scarcity, water price and irrigation infrastructure increase irrigation water allocative efficiency, while land fragmentation decreases it. We also show that farmers’ income loss due to higher water prices can be offset by increasing irrigation water use efficiency.

Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium

Previous studies have demonstrated that rice cultivated under flooded conditions has higher concentrations of arsenic (As) but lower cadmium (Cd) compared to rice grown in unsaturated soils. To validate such effects over long terms under Mediterranean conditions a field experiment, conducted over 7 successive years was established in SW Spain. The impact of water management on rice production and grain arsenic (As) and cadmium (Cd) was measured, and As speciation was determined to inform toxicity evaluation. Sprinkler irrigation was compared to traditional flooding.

Both irrigation techniques resulted in similar grain yields (similar to 3000 kg grain ha(-1)). Successive sprinkler irrigation over 7 years decreased grain total As to one-sixth its initial concentration in the flooded system (0.55 to 0.09 mg As kg(-1)), while one cycle of sprinkler irrigation also reduced grain total As by one-third (0.20 mg kg(-1)). Grain inorganic As concentration increased up to 2 folds under flooded conditions compared to sprinkler irrigated fields while organic As was also lower in sprinkler system treatments, but to a lesser extent. This suggests that methylation is favored under water logging. However, sprinkler irrigation increased Cd transfer to grain by a factor of 10, reaching 0.05 mg Cd kg(-1) in 7 years. Sprinlder systems in paddy fields seem particularly suited for Mediterranean climates and are able to mitigate against excessive As accumulation, but our evidence shows that an increased Cd load in rice grain may result.

Effects of arsenic-contaminated irrigation water on growth, yield, and nutrient concentration in rice

A study was undertaken to determine the effects of different concentrations of arsenic (As) in irrigation water on Boro (dry-season) rice (Oryza sativa) and their residual effects on the following Aman (wet-season) rice. There were six treatments, with 0, 0.1, 0.25, 0.5, 1, and 2 mg As L-1 applied as disodium hydrogen arsenate. All the growth and yield parameters of Boro rice responded positively at lower concentrations of up to 0.25 mg As L-1 in irrigation water but decreased sharply at concentrations more than 0.5 mg As L-1. Arsenic concentrations in grain and straw of Boro rice increased significantly with increasing concentration of As in irrigation water. The grain As concentration was in the range of 0.25 to 0.97 μg g-1 and its concentration in rice straw varied from 2.4 to 9.6 μg g-1 over the treatments. Residual As from previous Boro rice showed a very similar pattern in the following Aman rice, although As concentration in Aman rice grain and straw over the treatments was almost half of the As levels in Boro rice grain. Arsenic concentrations in both grain and straw of Boro and Aman rice were found to correlate with iron and be antagonistic with phosphorus. Copyright © Taylor & Francis Group, LLC.

Latent vs. Observed Variables: Analysis of Irrigation Water Efficiency Using SEM and SUR

In this paper we compare conceptualising single factor technical and allocative efficiency as indicators of a single latent variable, or as separate observed variables. In the former case, the impacts on both efficiency types are analysed by means of structural equation modeling (SEM), in the latter by seemingly unrelated regression (SUR). We compare estimation results of the two approaches based on a dataset on single factor irrigation water use efficiency obtained from a survey of 360 farmers in the Guanzhong Plain, China. The main methodological findings are that SEM allows identification of the most important dimension of irrigation water efficiency (technical efficiency) via comparison of their factor scores and reliability. Moreover, it reduces multicollinearity and attenuation bias. It thus is preferable to SUR. The SEM estimates show that perception of water scarcity is the most important positive determinant of both types of efficiency, followed by irrigation infrastructure, income and water price. Furthermore, there is a strong negative reverse effect from efficiency on perception.

A decision support system for managing irrigation in agriculture

In this paper, an automatic Smart Irrigation Decision Support System, SIDSS, is proposed to manage irrigation in agriculture. Our system estimates the weekly irrigations needs of a plantation, on the basis of both soil measurements and climatic variables gathered by several autonomous nodes deployed in field. This enables a closed loop control scheme to adapt the decision support system to local perturbations and estimation errors. Two machine learning techniques, PLSR and ANFIS, are proposed as reasoning engine of our SIDSS. Our approach is validated on three commercial plantations of citrus trees located in the South-East of Spain. Performance is tested against decisions taken by a human expert.

Adoption of farm-based irrigation water-saving techniques in the Guanzhong Plain, China

This article analyses adoption of farm-based irrigation water saving techniques, based on a cross-sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm-based water-saving technique. However, the traditional, inefficient techniques border and furrow irrigation are still prevalent whereas the use of advanced, more efficient techniques is still rather rare. We develop and estimate an adoption model consisting of two stages: awareness of water scarcity and intensity of adoption. We find that awareness of water scarcity and financial status enhance adoption of more advanced techniques whereas access to better community-based irrigation infrastructure discourages it. We furthermore find both community-based irrigation infrastructure and farm-based irrigation water-saving techniques have mitigating effects on production risk. From the results it follows that adoption can be stimulated via financial support and via extension aimed at enhancing awareness of water scarcity.

A Gap with a Deficit of Large Grains in the Protoplanetary Disk around TW Hya

We report 3 au resolution imaging observations of the protoplanetary disk aroundTW Hya at 145 and 233 GHz with the Atacama Large Millimeter/Submillimeter Array.Our observations revealed two deep gaps (~25-50 %) at 22 and 37 au and shallowergaps (a few %) at 6, 28, and 44 au, as recently reported by Andrews et al. (2016). Thecentral hole with a radius of  3 au was also marginally resolved. The most remarkablefinding is that the spectral index α(R) between bands 4 and 6 peaks at the 22 au gap.The derived power-law index of the dust opacity β(R) is  ~1.7 at the 22 au gap anddecreases toward the disk center to ~0. The most prominent gap at 22 au could becaused by the gravitational interaction between the disk and an unseen planet with amass of ≲1.5 MNeptune although other origins may be possible. The planet-induced gap is supported by the fact that β(R) is enhanced at the 22 au gap, indicating a deficitof mm-sized grains within the gap due to dust filtration by a planet.