EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

Regulation of non-relevant metabolites of plant protection products in drinking and groundwater in the EU: Current status and way forward.

Non-relevant metabolites are defined in the EU regulation for plant protection product authorization and a detailed definition of non-relevant metabolites is given in an EU Commission DG Sanco (now DG SANTE - Health and Food Safety) guidance document. However, in water legislation at EU and member state level non-relevant metabolites of pesticides are either not specifically regulated or diverse threshold values are applied. Based on their inherent properties, non-relevant metabolites should be regulated based on substance-specific and toxicity-based limit values in drinking and groundwater like other anthropogenic chemicals. Yet, if a general limit value for non-relevant metabolites in drinking and groundwater is favored, an application of a Threshold of Toxicological Concern (TTC) concept for Cramer class III compounds leads to a threshold value of 4.5 µg L(-1). This general value is exemplarily shown to be protective for non-relevant metabolites, based on individual drinking water limit values derived for a set of 56 non-relevant metabolites. A consistent definition of non-relevant metabolites of plant protection products, as well as their uniform regulation in drinking and groundwater in the EU, is important to achieve legal clarity for all stakeholders and to establish planning security for development of plant protection products for the European market.

Trends of inpatient spine augmentation: 2001-2008.

BACKGROUND AND PURPOSE: Vertebroplasty and kyphoplasty are 2 minimally invasive spine augmentation procedures currently used in the management of vertebral compression fractures. Our aim was to examine the NIS data base to identify trends in spine augmentation procedures over time. MATERIALS AND METHODS: Patients were identified from the NIS data base by using primary diagnosis codes (ICD-9-pathologic vertebral fracture, 733.13) and procedures codes (ICD-9-other repair of bone, 78.49; vertebroplasty, 81.65; kyphoplasty, 81.66). Means and their corresponding standard errors were compared for statistically significant differences by using the Z-test. RESULTS: Between 2001 and 2008, >240 000 inpatient spine augmentations were performed in the United States. From 2001 to 2008, there was a 741% increase in the number of hospital discharges for patients who underwent a spine augmentation, but the year-to-year rate of increase has been declining since 2001. From 2004 to 2008, >50 000 inpatient verterbroplasties and >152 000 inpatient kyphoplasties were identified. Compared with vertebroplasty, kyphoplasty patients were less often admitted from the emergency department (33% versus 56%, P < .001), had shorter postaugmentation hospital stays (2.3 versus 3.1 days, P < .001), had fewer comorbidities at presentation (1.4 versus 1.6, P < .01), and were less likely to be discharged to a long-term facility (28% versus 43%, P < .001). CONCLUSIONS: Significant differences were noted in multiple comparisons between vertebroplasty and kyphoplasty, including length of hospital stay and discharges to long-term facilities. However, these findings may simply reflect differences in practice patterns rather than real differences in efficacy between the procedures.

Volatilisation of crop protection chemicals from crop and soil surfaces under controlled conditions--prediction of volatile losses from physico-chemical properties.

Volatilisation of crop protection chemicals from soil and crop surfaces is one of a number of processes that may contribute to their dissipation in the environment. Therefore, information on the potential of a chemical to volatilise from these surfaces is required by international and national registration authorities. This paper reports the results of more than 190 experiments, which were carried out with 80 different crop protection chemicals under controlled conditions (laboratory and/or greenhouse) according to the BBA guideline. Percent loss values observed during 24 h after application are reported for 123 soil and 71 crop volatility studies. Generally, volatile losses from crop surfaces were found to be greater than from soil surfaces under comparable experimental conditions. It has been previously proposed that volatile losses from soil surfaces, from crops, and from aqueous systems can be estimated from physico-chemical parameters. The data are therefore analysed to determine whether a correlation exists between volatilisation and physico-chemical parameters, such as vapour pressure, Henry's law constant, water/air and soil/air distribution coefficients. It was found that these parameters can be used to make reasonable predictions of volatile losses from crop and soil surfaces, which can be expected for crop protection chemicals under controlled conditions. Vapour pressure was the best predictor of losses from soil and crops. The use of the soil/air distribution coefficient is an alternative for predicting/estimating the volatility potential of a chemical from soil. Based on direct measurements, no noticeable volatility can be expected from compounds with a vapour pressure below 10(-3) Pa from soil and 10(-4) Pa from crops, this is fully confirmed by indirect measurements. A tiered volatility testing scheme including appropriate trigger values is proposed.

Climatic and geographic influences on arboviral infections and vectors.

Those components of climate that are likely to have major effects upon the geographical distribution, seasonal incidence and prevalence of vector-borne diseases are described. On the basis of existing and predicted climatic variations, examples are given of the types of changes that are to be expected, using several internationally important human and animal arboviral diseases including Rift Valley fever and African horse sickness.

The barriers to bluetongue virus infection, dissemination and transmission in the vector, Culicoides variipennis (Diptera: Ceratopogonidae).

Transmission of bluetongue virus (BTV) by a vector species of Culicoides was studied using immunohistochemistry, virus titration and in vitro transmission tests. Adult female C. variipennis were used from two colonies that are either "transmission competent" or "transmission refractory" after oral infection with BTV. Intrathoracic (i.t.) injection of BTV into the haemocoel always resulted in a fully disseminated infection and transmission of virus in saliva. However, after ingestion of an infectious blood meal, only 30% (approximately) of midges from either colony became persistently infected. Although none of the orally infected insects from the "refractory" colony were able to transmit virus, 12% of those from the "competent" colony (containing > or = 10(3.0)TCID50 of virus/midge) did transmit BTV in their saliva. The most important barriers to BTV transmission in Culicoides vector species appeared to be a mesenteron infection barrier (MIB), which controls initial establishment of persistent infection, a mesenteron escape barrier (MEB) which can restrict virus to gut cells and a dissemination barrier (DB) which can prevent virus which enters the haemocoel from infecting secondary target organs. Culicoides variipennis do not appear to present either a salivary gland infection barrier (SGIB), or a salivary gland escape barrier (SGEB) to BTV.

Determination of dengue virus serotypes in individual Aedes aegypti mosquitoes in Colombia.

Adult Aedes aegypti mosquitoes were collected in Puerto Triunfo, central Colombia, where dengue is endemic, during a six month period. Viral infection within the head of each individual mosquito was identified by an immunofluorescent assay (IFA) using a flavivirus-specific monoclonal antibody. The dengue virus serotype, present in each flavivirus-positive specimen, was then determined in portions of the remaining thorax using IFAs with serotype-specific monoclonal antibodies. Among 2065 female Aedes aegypti collected and tested, twenty-four flavivirus-positive individuals were found (minimum infection rate 11.6%), three identified as dengue type-1 and twenty-one as dengue type-2 virus. This was consistent with the isolation of only these two serotypes of dengue virus from dengue fever patients within this town. No vertical transmission of dengue virus could be detected in 1552 male Aedes aegypti collected. This method is inexpensive, simple, rapid to perform and suitable for use in developing countries to identify and distinguish different serotypes of dengue virus in their vectors during eco-epidemiological investigations.

The effect of sleep deprivation and exercise load on isokinetic leg strength and endurance.

Isokinetic leg strength and fatigue were measured in 24 male U.S. Marine Corps volunteers in a simulated sleep loss and unusually heavy work scenario. Knee extension and flexion peak torque (PT) were measured at three isokinetic speeds (1.57, 2.62 and 3.66 rad.s-1) followed by 45 consecutive maximal reciprocal contractions at 3.14 rad.s-1 to measure fatigue index (FI). All subjects were retested 2 days later following 30-h sleep deprivation (SD). The exercise group (n = 12) spent 25 1-h sessions performing computer tasks, filling out questionnaires and walked 1.61 km with a 50% gross body mass pack load, during each of the 25 sessions. The control group (n = 12) did likewise but did not exercise. Repeated measures ANOVA indicated that flexion PT at 1.57 rad.s-1 decreases (P < 0.013) after SD. Exercise did not affect FI but did decrease PT. It was concluded that carrying a 50% load produces decrements in PT for both extension and flexion but more so for flexion. SD affected PT but had no effect on FI.

Post-inoculation changes in enzyme activity of Aedes aegypti infected with Chikungunya virus.

Levels of acetylcholinesterase, non-specific esterases, glutathione-S-transferase and glucose-6-phosphate dehydrogenase in Aedes aegypti (L.) mosquitoes inoculated intrathoracally with Chikungunya virus were elevated, as compared to uninoculated control insects. A number of these enzymes are important in the insects defence mechanism against xenobiotics, such as pesticides. Malathion bioassays indicated a reduction in the susceptibility of experimentally injected insects with virus or virus-free inoculum, compared to non-inoculated controls. However, insects which were mock-inoculated (injected with no inoculum) showed a similar reduction in susceptibility suggesting that the observed effect was due to the mobilization of a defence reaction in the mosquitoes in response to injury during inoculation.

Trends, priorities and policy directions in the control of vector-borne diseases in urban environments.

The habitats available in urban environments tend to be rather lacking in diversity compared to those in the countryside, and relatively few species are able to exploit them. Those that can, however, often find themselves relatively well provided with food and places to live, and relatively free of competitors and predators. This applies not only to such well-known species as the house-sparrow, but also to most of the important mosquito vectors of human disease in urban areas. Human city dwellers thus tend to be exposed to a different spectrum of disease than their rural counterparts. This review describes how the physical and social changes associated with urbanization have altered the transmission of vector-borne disease. It concentrates on the important mosquito-borne infections: malaria, dengue and filariasis. Dengue virus vectors breed in relatively clean water in man-made containers, while urban filariasis vectors breed in highly polluted water, and these mosquitoes have now been spread by man's activities to almost every tropical city. With important exceptions, anopheline malaria vectors have not generally succeeded in adapting to urban life, but malaria can still be a problem where there are rural pockets in the middle of town. Each of these problems requires control using different technologies and timing. The following policy implications are stressed. The areas of responsibility between different sectors of the local services (health, water supply, sanitation), and between these and the public, need to be clearly defined. Due to the biological complexities of vector-borne disease, decentralized primary health care systems are generally incapable of ensuring that control efforts are adequately targeted in time and space. Community support is essential but specialized technical skills are also required.

Changes in enzyme titres with age in four geographical strains of Aedes aegypti and their association with insecticide resistance.

The enzymes acetylcholinesterase, glutathione S-transferase (GST), glucose 6-phosphate dehydrogenase (G6PD), and general esterases were assayed in four strains of Aedes aegypti mosquitoes aged between 1 and 30 days. Microtitre plate methods were used to assay activity in the homogenates of individual mosquitoes. The levels of GST and G6PD declined with the age of the mosquitoes, while the activity for the other enzymes remained constant. Soluble protein content was also found to decline with mosquito age in all the strains. Insecticide bioassays showed that two strains (Trinidad and Virtudes) of Ae. aegypti were resistant to DDT, deltamethrin and malathion, whereas two other strains (Bangkok and Indian) were susceptible to all four classes of insecticides tested. Higher esterase activity levels in the resistant compared to the susceptible strains were assumed to be the cause of organophosphate resistance. The combination of DDT and deltamethrin resistance in two strains with normal GST and G6PD characteristics suggests that a kdr-type nerve insensitivity mechanism may be involved.

Arbovirus-mosquito interactions and vector specificity.

Mosquito-borne arboviruses cause important and expanding disease problems. In this article, Colin Leake reviews the increasing knowledge of the complex interaction of arboviruses with their mosquito vectors and mosquito cells, in vitro, and considers the factors influencing vector specificity and vector competence.

Comparison of body composition and somatotype of trained female triathletes.

The body composition and somatotype of 16 trained female triathletes aged 18.8-32.8 years were measured. All of the subjects were engaged in a competitive training programme and participated in the same triathlon. Anthropometric variables included height, mass, selected diameters, girths and skinfolds, and a Heath-Carter anthropometric somatotype. Body composition was determined by hydrostatic weighing procedures and skinfold patterns. Comparisons were made with Olympic swimmers and runners. The triathletes had a mean body mass of 55.2 kg and a mean height of 162.1 cm. When compared to swimmers, the triathletes were somewhat shorter and significantly (P less than 0.005) older. On most other measures, including a balanced mesomorph somatotype of 3.1-4.3-2.6, they were similar to swimmers. This group of triathletes were generally heavier, less lean, more mesomorphic and less ectomorphic than elite runners. Reported body densities from other studies indicated little difference between the triathletes and other groups. Skinfold patterns were similar in shape for all groups, but the runners had smaller values, at all sites, than either swimmers or triathletes. Because of lack of information on cyclists, adequate comparisons were not possible. Regression analysis indicated that training parameters were more important than anthropometric measures in the prediction of performance. It was concluded that this group of triathletes were closer, with respect to both body composition and somatotype, to swimmers than to runners.

The pathogenesis of Japanese encephalitis virus in Culex tritaeniorhynchus mosquitoes.

Culex tritaeniorhynchus were inoculated intrathoracically with mosquito and human strains of Japanese encephalitis virus and maintained at 26 degrees C or 32 degrees C. Virus titration and localization of viral antigen by avidin-biotin immunoperoxidase staining were done at intervals up to 21 days. Marked differences were noted in the tempo of organ involvement at the 2 temperatures; at both there was initial infection of fat body cells followed by selective infection of the central nervous system (CNS), with consistent infection of cells of the compound eye, patchy involvement of cephalic, thoracic and abdominal ganglia and no infection of Johnston's organ. CNS infection was always present 4 days after infection, when salivary gland involvement was first seen at 32 degrees C; at 26 degrees C CNS infection preceded salivary gland infection by 2 weeks. Late involvement of gut cells, pericardial cells and oviducts was also found, with no involvement of muscle.

Isolation of Japanese encephalitis virus from clinical specimens using a continuous mosquito cell line.

During the 1983 Japanese encephalitis (JE) epidemic in northern Thailand, we systematically attempted to isolate JE virus (JEV) from clinical specimens collected from 49 consecutive JE patients at 1 provincial hospital. Fresh acute plasma and cerebrospinal fluid (CSF) samples and postmortem brain samples were immediately inoculated onto cultured monolayers of Aedes pseudoscutellaris (LSTM-AP-61) cells which had been shipped to the epidemic site. None of 49 plasma samples yielded virus. None of 30 fresh CSF samples from nonfatal cases yielded virus, but 5 of 15 (33%) CSF samples from fatal cases did. Inoculation of fresh brain specimens obtained at autopsy yielded virus in every case attempted (7 of 7), whereas postmortem needle biopsy specimens of brain yielded virus in only 1 of 4 cases. Isolates were most frequently successful using thalamic tissue (6 of 7 cases), but isolates were also commonly obtained from frontal cortex (4/7), occipital cortex (4/7), cerebellum (4/7), medulla (4/7) and pons (2/7).

Virus isolations from mosquitoes collected during the 1982 Japanese encephalitis epidemic in northern Thailand.

From 16 June to 15 August, 1982 CDC light traps were used to collect mosquitoes in the province of Kamphaengphet, N. Thailand. 353,042 mosquitoes comprising 59 species were collected and identified, and 345,173 were placed in pools for attempted virus isolation by inoculation of C6/36 Aedes albopictus mosquito cell cultures. Viruses were isolated from 63 mosquito pools. These comprised 56 flaviviruses, identified as 35 isolates of Japanese encephalitis (JE) virus strains, 18 strains of Tembusu (TEM) virus and three untyped flaviviruses (FLA); three alphaviruses, identified as the first isolates of Getah (GET) virus to have been made in Thailand; and four viruses which are still unidentified. Most virus isolates were from Culex tritaeniorhynchus mosquitoes collected in carbon dioxide baited light traps. JE virus was isolated only over a ten-day period and the last isolate was obtained one week before the peak of admission of human encephalitis cases at Kamphaengphet Provincial Hospital. Rapid screening of isolates grown on Ae. pseudoscutellaris (LSTM-AP-61) mosquito cells by indirect immunofluorescence using flavivirus group-specific and JE-specific monoclonal antibodies showed a high degree of correlation with plaque reduction neutralization tests. An antigen capture enzyme immunoassay (EIA) test successfully identified about 50% of the JE virus positive pools, but the method saved considerable processing time.

Fatal outcome in Japanese encephalitis.

Forty-nine consecutive patients with laboratory-confirmed acute Japanese encephalitis were studied to identify risk factors present at hospital admission which were associated with a fatal outcome. Sixteen patients (33%) died. The following constellation of findings correlated with a fatal outcome: infectious virus in cerebrospinal fluid (CSF), low levels of Japanese encephalitis virus-specific IgG and IgM in both CSF and serum, and a severely depressed sensorium. Age, sex, days ill before admission, distance from home to the hospital, past medical history, CSF protein content, and CSF leukocyte count were not significant risk factors. Among patients hospitalized for acute Japanese encephalitis, a vigorous virus-specific immunoglobulin response, both systemically and locally within the central nervous system, is a good marker for survival, and may be an inherently important factor in recovery from illness.