Water Resource Models in the Mekong Basin: A Review

Development of the water resources of the Mekong Basin is the subject of intense debate both within the Mekong region and internationally. Water resources modelling is playing an increasingly important role in the debate, with significant effort in building integrated modelling platforms to describe the hydrological, ecological, social and economic impacts of water resource development. In the hydrological domain, a comprehensive set of models has been effective in building understanding of the system, and in identifying and describing the issues and trade-offs involved in basin-scale water planning. In the ecological and social domains, quantitative modelling has not progressed very far; geo-spatial analysis and qualitative frameworks remain the most commonly used tools. Economic models have been used to assess the costs and benefits of water resources development and to describe the trade-offs between different sectors and users. These analyses are likely to play an important role in the policy and planning debate, but are hampered by uncertainties in valuation of ecosystem services. Future efforts should focus on optimising the use of existing model platforms for the Mekong, including structured comparison of multiple hydrological models to quantify errors and identify an optimum set of modelling tools for different applications. A comprehensive research effort is needed to incorporate groundwater into hydrological models for regional planning. Options for social impact assessment should be reassessed before major investments are made in complex modelling platforms, and participatory social survey methods evaluated as part of an integrated assessment framework.     

Superconducting and normal state properties of Li1+x Ti2−x O4 spinel compounds. I. Preparation,crystallography, superconducting properties,electrical resistivity,dielectric behavior,and magnetic susceptibility

LiTi ₂ O ₄ is one end member of the homogeneity range of the spinel phase Li _1+x Ti _2–x O ₄ (0x1/3) and is superconducting at temperatures up to 13.7 K. Various measurements were carried out in order to characterize the superconducting and normal state properties of LiTi ₂ O ₄ and of other compositions within the homogeneity range of the spinel phase. These measurements establish LiTi ₂ O ₄ as ad-band superconductor and show thatT _c decreases to <1.5 K forx0.1. This disappearance of superconductivity with increasingx was found to be correlated with anomalous changes in the lattice parameter with composition, and, from electrical resistivity measurements, is tentatively attributed to the occurrence of a composition-induced metal-semiconductor transition atx0.1. The metallic character of LiTi ₂ O ₄ and the composition dependence of the observed electrical properties are shown to follow from crystallographic considerations.Research sponsored by the Air Force Office of Scientific Research, Air Force Systems Command, USAF, under AFOSR Contract Number AFOSR/F-44620-C-0017.     

The contribution of communications signals to noise exposure

Man-mounted miniature recording equipment has been used to measure the electroacoustic conditions obtaining in cockpits of aircraft and at the pilot's ear during operational sorties in the Royal Air Force. Although this paper considers the measurements taken that relate to the total noise exposure (noise dose) received by aircrew, the results apply equally to anyone who is exposed to high noise and requires communications.

Comparison of the noise at the ear with the cockpit noise gave a measure of headgear attenuation which was used to adjust a 1/3-octave filter. Playing cockpit noise tapes through this filter to a noise dose meter gave the noise dose that would have been experienced had there been no communications signals. The results showed that the communications signals at the ear, averaging 40% of the sortie time, are a major contributor to the total dose, and, without the signals, the dose averaged about 6 dB less. In view of the Health and Safety at Work Act, 1974, employers should be aware of the additional dose to which employees are exposed because of communications.

A method for the prediction of noise dose is proposed where communication takes place in a noisy environment.     

Seismic Performance and Deformation of Levees: Four Case Studies

During the 1989 Loma Prieta earthquake the Pajaro River levees near Watsonville, Calif., spread laterally at multiple locations. Four of these locations are discussed in this paper. At one location, an industrial facility was also damaged and a dispute arose as to whether lateral spreading of the adjacent levee was the cause. Stability analyses were made of the industrial site for conditions before, during, and after the earthquake. To confirm the findings, analyses were also made of three other nearby locations where the actual deformation was documented and the subsurface conditions are well defined. The calculated levee deformations at the four locations are quite consistent with the observed movements (up to 60 cm). This experience provides increased confidence in the methods of analysis described, for the characterized subsurface conditions, and the range of ground motions experienced. Additional analyses made using the more recently developed multilinear regression lateral-spreading model (e.g., Youd et al. in 1999) yielded inconsistent results.     

Associations between evaporative cooling and dust‐mite allergens,endotoxins, and β‐(1 → 3)‐d‐glucans in house dust: A study of low‐income homes

Recent work suggests that evaporative coolers increase the level and diversity of bioaerosols, but this association remains understudied in low‐income homes. We conducted a cross‐sectional study of metropolitan, low‐income homes in Utah with evaporative coolers (n = 20) and central air conditioners (n = 28). Dust samples (N = 147) were collected from four locations in each home and analyzed for dust‐mite allergens Der p1 and Der f1, endotoxins, and β‐(1 → 3)‐d ‐glucans. In all sample locations combined, Der p1 or Der f1 was significantly higher in evaporative cooler versus central air conditioning homes (OR = 2.29, 95% CI = 1.05‐4.98). Endotoxin concentration was significantly higher in evaporative cooler versus central air conditioning homes in furniture (geometric mean (GM) = 8.05 vs 2.85 EU/mg, P < .01) and all samples combined (GM = 3.60 vs 1.29 EU/mg, P = .03). β‐(1 → 3)‐d ‐glucan concentration and surface loads were significantly higher in evaporative cooler versus central air conditioning homes in all four sample locations and all samples combined (P < .01). Our study suggests that low‐income, evaporative cooled homes have higher levels of immunologically important bioaerosols than central air‐conditioned homes in dry climates, warranting studies on health implications and other exposed populations.     

Naive random subspace ensemble with linear classifiers for real-time classification of fMRI data

Functional magnetic resonance imaging (fMRI) provides a spatially accurate measure of brain activity. Real-time classification allows the use of fMRI in neurofeedback experiments. With limited labelled data available, a fixed pre-trained classifier may be inaccurate. We propose that streaming fMRI data may be classified using a classifier ensemble which is updated through naive labelling. Naive labelling is a protocol where in the absence of ground truth, updates are carried out using the label assigned by the classifier. We perform experiments on three fMRI datasets to demonstrate that naive labelling is able to improve upon a pre-trained initial classifier.     

Restriction of meat,fish, and poultry in omnivores improves mood: A pilot randomized controlled trial

Background  

Omnivorous diets are high in arachidonic acid (AA) compared to vegetarian diets. Research shows that high intakes of AA promote changes in brain that can disturb mood. Omnivores who eat fish regularly increase their intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), fats that oppose the negative effects of AA in vivo. In a recent cross-sectional study, omnivores reported significantly worse mood than vegetarians despite higher intakes of EPA and DHA. This study investigated the impact of restricting meat, fish, and poultry on mood.     

Investigation on Electrical and Dielectric Behaviour of Halloysite Nanotube Incorporated Polycarbonate Nanocomposite Films

Polycarbonate (PC) nanocomposites were fabricated by solution intercalation method with halloysite nanotubes (HNTs) as reinforcement. The effects of HNT content on the structural and dielectric properties were investigated. The properties of the fabricated films were probed with the intention to establish the consequence of nano-fillers on electrical characteristics/behaviours with PC. The incorporation of HNT generates notable performance enhancements through reinforcement effect. The electrical conductivity of polycarbonate got better when more than 4 wt% HNT is added. Interestingly, the integration of HNT significantly increases the dielectric permittivity of composite films with low dielectric loss which makes the nanocomposites attractive in practical applications such as electrical devices, electrical packaging and capacitors. Furthermore, the structural aspects were elucidated by X-Ray diffraction studies, Fourier transform infrared spectroscopy and dispersion of nanofillers in PC matrix were evaluated by scanning electron microscopy.