Hygiene,Sanitation, and Water: What Needs to Be Done?

In the final article in a four-part PLoS Medicine series on water and sanitation, Sandy Cairncross and colleagues outline what needs to be done to make significant progress in providing more and better hygiene, sanitation, and water for all.     

Towards Physarum Robots： Computing and Manipulating on Water Surface

Plasmodium of Physarum polycephalum is an ideal biological substrate for implementing concurrent and parallel com-putation, including combinatorial geometry and optimization on graphs. The scoping experiments on Physarum computing in conditions of minimal friction, on the water surface were performed. The laboratory and computer experimental results show that plasmodium of Physarum is capable of computing a basic spanning tree and manipulating of light-weight objects. We speculate that our results pave the pathways towards the design and implementation of amorphous biological robots.     

Water stress and kaolin spray affect herbivorous insects’ success on cotton

Ecological hypotheses of plant–insect herbivore interactions suggest that insects perform better on weakened plants and plants grown under optimal conditions are less damaged. This study tested the hypothesis that the colonization and oviposition rates by pests with different feeding strategies and levels of specialization are affected in different ways by two conditions commonly faced by commercially grown plants–water deficit and application of kaolin sprays, a reducer of abiotic plant stressors. We used four major pests of cotton as insect herbivore models. Three were chewing Lepidoptera: Alabama argillacea (Hüb.), a monophagous pest on cotton; Heliothis virescens (Fabr.), which is polyphagous, but with cotton as a primary host; and Chrysodeixis includens (Walk.), which is polyphagous, with cotton as secondary host. The fourth pest was a sap-sucking species, the polyphagous whitefly Bemisia tabaci (Gen.). In both choice and no-choice trials, the three chewing pests oviposited significantly less upon water-stressed plants; the greatest effect was observed for C. includens (>90 % reduction in oviposition under choice and >58 % under no-choice conditions). In contrast, the sap-sucking B. tabaci exhibited statistically more colonization and oviposition on water-stressed plants. Application of kaolin sprays reduced colonization and oviposition by all herbivore species tested, irrespective of irrigation regime and feeding strategies.     

Entomological Research： Progress and Prospects

Because of their economic importance, ancient evolutionary history, and extensive diversity, insects are of great interest to humans. As a result of their economic importance and scientific values, entomology, a branch of science that deals with insects in various aspects, has been advancing rapidly, especially in the past two decades. Coincidentally during the same period, numerous young Chinese scientists have been abroad to pursue advanced studies as graduates or to conduct research as scholars in various entomological fields. Most of them have made great achievements in their areas due to their strong commitment and diligent work. This can be evidenced by a huge number of their publications in highly ranked scientific journals. As a result of their outstanding contributions, many of them have been promoted to faculty positions in universities, government agencies, and other institutions around the world. Armed with rich research experience, modern technologies, and comprehensive expertise, these overseas entomologists want to make contributions to accelerate entomological research in China. The book Entomological Research： Progress and Prospects is one of their strides in this direction.     

Influence of Water Miscible Organic Solvents on α-chymotrypsin in Solution and Immobilized on Eupergit CM

The effects of the water-miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, N,N′-dimethylformamide and tetrahydrofuran) on the stability and catalytic activity of α-chymotrypsin (CT) immobilized on Eupergit CM were studied. Enhanced stabilities and activities were observed both as a consequence of immobilization and the presence of organic solvent, which in combination provide long term (at least 24 h) retention of activity, and up to 50-fold increase in 50% (v/v) methanol in buffer. Low quantities (20%, v/v) of acetonitrile not only prevented CT inactivation by autolysis at 20°C but also induced a significant increase in the activity of both free (six-fold) and immobilized (two-fold) CT.Linus Olofsson and Pernilla Söderberg authors have contributed equally to the work.     

First Announcement of and Call for Papers for ＂Forum on Genetics Progress and Human Health＂

＂Forum on Genetics Progress and Human Health＂ will be held at Yunnan University in Kunming, Yunnan Province, China, in November, 2007. The forum focuses on the current progress and future directions in all major aspects of human genetics and medical genetics. The submitted papers written in English will be considered for publication in Journal of Genetics and Genomics after peer-review and papers in Chinese in Hereditas （Beijing）. Papers＇ in the following areas are encouraged for submission and outstanding papers will be selected for oral presentation in the forum.     

First Announcement of and Call for Papers for ＂Forum on Genetics Progress and Human Health＂

＂Forum on Genetics Progress and Human Health＂ will be held at Yunnan University in Kunming, Yunnan Province, China, in November, 2007. The forum focuses on the current progress and future directions in all major aspects of human genetics and medical genetics. The submitted papers written in English will be considered for publication in Journal of Genetics and Genomics after peer-review and papers in Chinese in Hereditas （Beijing）. Papers in the following areas are encouraged for submission and outstanding papers will be selected for oral presentation in the forum.     

Rise and Demise of Bioinformatics? Promise and Progress

The field of bioinformatics and computational biology has gone through a number of transformations during the past 15 years, establishing itself as a key component of new biology. This spectacular growth has been challenged by a number of disruptive changes in science and technology. Despite the apparent fatigue of the linguistic use of the term itself, bioinformatics has grown perhaps to a point beyond recognition. We explore both historical aspects and future trends and argue that as the field expands, key questions remain unanswered and acquire new meaning while at the same time the range of applications is widening to cover an ever increasing number of biological disciplines. These trends appear to be pointing to a redefinition of certain objectives, milestones, and possibly the field itself.     

Sanitation and Hygiene-Specific Risk Factors for Moderate-to-Severe Diarrhea in Young Children in the Global Enteric Multicenter Study, 2007–2011: Case-Control Study

BackgroundDiarrheal disease is the second leading cause of disease in children less than 5 y of age. Poor water, sanitation, and hygiene conditions are the primary routes of exposure and infection. Sanitation and hygiene interventions are estimated to generate a 36% and 48% reduction in diarrheal risk in young children, respectively. Little is known about whether the number of households sharing a sanitation facility affects a child''s risk of diarrhea. The objective of this study was to describe sanitation and hygiene access across the Global Enteric Multicenter Study (GEMS) sites in Africa and South Asia and to assess sanitation and hygiene exposures, including shared sanitation access, as risk factors for moderate-to-severe diarrhea (MSD) in children less than 5 y of age.Methods/FindingsThe GEMS matched case-control study was conducted between December 1, 2007, and March 3, 2011, at seven sites in Basse, The Gambia; Nyanza Province, Kenya; Bamako, Mali; Manhiça, Mozambique; Mirzapur, Bangladesh; Kolkata, India; and Karachi, Pakistan. Data was collected for 8,592 case children aged <5 y old experiencing MSD and for 12,390 asymptomatic age, gender, and neighborhood-matched controls. An MSD case was defined as a child with a diarrheal illness <7 d duration comprising ≥3 loose stools in 24 h and ≥1 of the following: sunken eyes, skin tenting, dysentery, intravenous (IV) rehydration, or hospitalization. Site-specific conditional logistic regression models were used to explore the association between sanitation and hygiene exposures and MSD. Most households at six sites (>93%) had access to a sanitation facility, while 70% of households in rural Kenya had access to a facility. Practicing open defecation was a risk factor for MSD in children <5 y old in Kenya. Sharing sanitation facilities with 1–2 or ≥3 other households was a statistically significant risk factor for MSD in Kenya, Mali, Mozambique, and Pakistan. Among those with a designated handwashing area near the home, soap or ash were more frequently observed at control households and were significantly protective against MSD in Mozambique and India.ConclusionsThis study suggests that sharing a sanitation facility with just one to two other households can increase the risk of MSD in young children, compared to using a private facility. Interventions aimed at increasing access to private household sanitation facilities may reduce the burden of MSD in children. These findings support the current World Health Organization/ United Nations Children''s Emergency Fund (UNICEF) system that categorizes shared sanitation as unimproved.     

Does Global and Local Vision Have an Impact on Creative and Analytic Thought? Two Failed Replications

According to GLOMO^sys (the GLObal versus LOcal processing MOdel, a systems account), an important distinction is that between a local and a global processing system: The former processes information in parts, the latter processes it globally. These systems can be activated by perceptual processing and carry over to subsequent conceptual processing, in particular to analytical and creative thought. A conceptual and a high-powered close replication of previously reported studies test predictions of GLOMO^sys for analytical thought and for analytical and creative thought, respectively. The present studies found no evidence that processing style primed via the Navon letter task has an impact on creative or analytic thought.     

Aeroterrestrial Microalgae Growing in Biofilms on Facades—Response to Temperature and Water Stress

The photosynthetic performance of a microalgal biofilm colonizing a building facade was investigated between February and July 2004, with an emphasis on changing water availability and air humidity. The fluorimetric measurements of the quantum efficiency (F _v/F _m) indicated diurnal activity patterns. At most sampling dates the algal biofilm photosynthesized particularly in the morning and substantially less in the afternoon. As long as liquid water was present, the microalgae exhibited at least some degree of photosynthesis. However, F _v/F _m values never exceeded 0.4, pointing to slight photoinhibition or damage of the cells. Dried cells without photosynthesis could recover within minutes after artificial moistening.Three microalgal strains were isolated from aeroterrestrial biofilms and established as unialgal cultures. Their photosynthesis and growth were characterized under different air humidities and temperatures. Photosynthesis and growth of strain ROS 55/3 (Stichococcus sp.) showed similar patterns with decreasing relative air humidity. Positive growth and optimum photosynthesis were recorded at 100% relative air humidity. At air humidities below 93%, both processes were strongly inhibited. All studied strains grew between 1 and 30°C with optimum rates at 20–23°C, indicating eurythermal features.The data indicate that liquid water or 100% air humidity are the prerequisite for optimum photosynthesis and growth of aeroterrestrial microalgae. However, when dried and consequently inactive, these microorganisms can recover quickly if water is suddenly available, e.g., after rain events. These physiological capabilities explain well the ecological success of aeroterrestrial microalgae in occupying many man-made substrata such as building facades and roof tiles in urban areas.     

Effects of Planting Densities on Water Quality Improvements and Pontederia cordata’s Physiology

Various planting densities (5, 10, or 20 plants per tank) of Pontederia cordata were water-cultivated in purifying tanks to treat polluted water. Seasonal effects of the planting densities on the water quality improvement and the morphology and physiology of the plant were analyzed. Results indicated that planting densities affected the nitrogen and phosphorus removal of water, and the morphology and physiology of plants, including activity of peroxidise and catalase, content of chlorophyll and soluble protein (SP), the length of root, stem and leaf, tiller number and root density. When planting density increased from 10 to 20 plants per tank, the morphology and physiology of plants, and the nitrogen and phosphorus removal by plants improved slowly, but caused a tiller number decline in individual plants. This variation was significant in autumn, and associated with seasonal variations of plant physiology. During autumn, there were 26 tillers in each plant with 10 plants per tank, compared to 14 tillers per plant with 20 plants per tank. Increase in the nitrogen and phosphorus contents of the plants for 5–10 plants per tank was 5.41 and 0.79 g kg^–1, compared to 1.17 and 0.12 g kg^–1 for 10–20 plants per tank, respectively.     

Effects of Lithium and Lamotrigine on Oxidative–Nitrosative Stress and Spatial Learning Deficit After Global Cerebral Ischemia

Lithium (Li) and lamotrigine (LTG) have neuroprotective properties. However, the exact therapeutic mechanisms of these drugs have not been well understood. We investigated the antioxidant properties of Li (40 and 80 mg/kg/day) and LTG (20 and 40 mg/kg/day) in a rat model of global cerebral ischemia based on permanent bilateral occlusion of the common carotid arteries (BCAO). Nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione reductase (GSH-R), catalase (CAT) and superoxide dismutase (SOD) levels were measured as an indicator of oxidative–nitrosative stress in both prefrontal cortex (PFC) and hippocampus after 28 days of treatment. The spatial learning disability was also assessed at the end of the study by Morris water maze (MWM) test. All oxidative–nitrosative parameters were found to be higher in the groups under treatment than in sham. Both drugs caused a decrease in PFC NO and MDA elevation, meanwhile the increase in GSH, GSH-R, CAT and SOD levels was significantly more evident in treated groups. We also found higher PFC GSH-R and hippocampal SOD levels in BCAO + Li (80 mg/day) treated group when compared with BCAO + LTG 40 mg/day. MWM test data showed a similar increase in spatial learning ability in all groups under treatment. We found no other statistical difference in comparison of treated groups with different dosages. Our findings suggested that Li and LTG treatments may decrease spatial learning memory deficits accompanied by lower oxidative–nitrosative stress in global cerebral ischemia. Both drugs may have potential benefits for the treatment of vascular dementia in clinical practice.     

Progress of Study on Chitosan in Regulating Plants’Growth and Eliciting Plants’Defense Responses

Important effect of chitosan on regulating plant growth , eliciting plant resistance to disease and it’s possible operating mechanism are reviewed . Chitosan shows evidence physiological effect on the key enzymes of ammonia assimilation and enhances the amination capacity in plant, which is in favor of biology synthesize and accumulation of protein . Thus , chitosan improves nutrition quality and horticulture properties of plant . Moreover , chitosan rapidly stimulates plant defense responses , then startups defensive system and elevates resistance to disease . To a further understanding of the mechanism of chitosan on plant , we have isolated and determined some biochemical properties of a chitosan-bingding protein .     

Effects of Different Levels of Water Stress on Leaf Water Potential, Stomatal Resistance, Protein and Chlorophyll Content and Certain Anti-oxidative Enzymes in Tomato Plants

A greenhouse experlment was performed In order to Investigate the effects of dlfferent levels of water stress on leaf water potentlal （ψw）, stomatal resistance （rs）, protein content and chlorophyll （Chl） content of tomato plants （Lycoperslcon esculentum Mill. cv. Nlkita）. Water stress was Induced by addlng polyethylene glycol （PEG 6 000） to the nutrlent solution to reduce the osmotlc potential （ψs）. We Investlgated the behavlor of antl-oxldant enzymes, such as catalase （CAT） and superoxide dlsmutase （SOD）, durlng the development of water stress. Moderate and severe water stress （i.e. ψs= -0.51 and -1.22 MPa, respectlvely） caused a decrease In ψw for all treated （water-stressed） plants compared with control plants, wlth the reductlon belng more pronounced for severely stressed plants. In addltion, rs was slgnlflcantly affected by the Induced water stress and a decrease in leaf soluble protelns and Chl content was observed. Whereas CAT actlvlty remained constant, SOD actlvlty was increased in water-stressed plants compared wlth unstressed plants. These results Indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress condltlons. Moreover, It suggests the possibllity of using this enzyme as an addltional screening crlterlon for detecting water stress in plants.     

Effect of Silt, Water and Periphyton Quality on Survival and Growth of the Mayfly Heptagenia Sulphurea

The herbivorous mayfly Heptagenia sulphurea is characteristic of rivers with stony bottoms. Records from the 20th century showed that this species had disappeared from the Common Meuse in the Netherlands, probably due to river regulation or changes in water quality. A field survey in 2003 showed that H. sulphurea was present in the Geul tributary, approximately 300 m upstream of its confluence with the Common Meuse. H. sulphurea has not recolonized the Common Meuse despite improvements in water quality over the last decades. Concentration of suspended sediments in the River Meuse, however, is still high, much higher than in the beginning of the 20th century. The presence of a silt layer may limit the return of H. sulphurea in this river by reducing availability and quality of its food. The prime objective of this study was to investigate the impact of silt on survival and growth of H. sulphurea in a laboratory experiment. Furthermore, the impact of water and periphyton quality from the Common Meuse on survival and growth of this mayfly was also investigated. Results showed that neither water quality nor cultured periphyton from the Common Meuse reduced survival and growth of H. sulphurea. The presence of a silt layer resulted in a significantly lower growth rate of the mayfly larvae. It is concluded that the silt layer reduces the accessibility of the food. Covering of food is possibly one of the main factors limiting the recolonization of H. sulphurea and probably other benthic grazers in the Common Meuse.     

Global nitrogen fertilizer supply and demand outlook

This paper presents a brief overview of the world nitrogen fertilizer demand, highlights trends in the global and regional developments of production capacity and provides a medium-term perspective of the global nitrogen supply/demand balance.     

Four Biofuel Species’ Responses to Periodic Flooding and High Water Tables on a Florida Histosol

Rising energy costs, decreasing soil depth, and best management practices that require on-farm water retention have led to interest in flood-tolerant bioenergy crops for production in the Everglades Agricultural Area (EAA) of Florida. Information on the effects of high water tables on sugarcane (Saccharum spp. L.) is available; however, little is known about the bioenergy crops elephant grass (Pennisetum purpureum Schumach.), energycane (Saccharum spp. L.), and giant reed (Arundo donax L.). The objective of this study was to evaluate the role of water-table depth on the yields, morphology, physiology, and early season growth of these three bioenergy species in relation to sugarcane. The species were grown in a greenhouse and subjected to three water management strategies, ?40 or ?16 cm constant water-table depths, and bi-weekly flooding with drainage to ?40 cm. The experiment was conducted in plant-cane, first-ratoon, and successive plant-cane crop cycles.       Periodic flooding relative to a ?40 cm constant water table significantly reduced dry weights and leaf area index and increased aerenchyma development. Averaged among crops, dry weight declined by 32, 49, 37, and 52% while leaf area index (LAI) decreased by 31, 50, 46, and 57% for giant reed, elephant grass, energycane, and sugarcane, respectively, in response to flooding. Aerenchyma proportional area of the stalk increased by 52, 90, and 95% for elephant grass, energycane, and sugarcane, respectively, but aerenchyma in giant reed decreased by 11%. High yields and stalk populations for all water tables were observed in energycane and elephant grass. These two species show potential for bioenergy production in the EAA. Field trials are recommended to confirm production scale yield.