213 research outputs found
Active joints for microrobot limbs
The authors propose an electrostatic actuator for active joints. The active joint consists of two plates, one of which is a bilayer and bent by the bimorph effect. The plates are clamped to each other at one edge. A voltage between the plates leads to a very large field at the clamp where the plates are in intimate contact, thereby producing a force large enough to pull the bent bimorph cantilever beam to the other plate. The design uses an actuator in which large electrical forces acting over a short distance are used to produce large deflections. An appealing application of this actuation principle is seen in active joints for robot arms, e.g. by attaching members to the actuator and by combining two or more active joints and members to form micro robot arms, legs and grippers
Arsenic in the Water, Soil Bedrock, and Plants of the Ester Dome Area of Alaska
Concentrations of arsenic as large as 10 ppm (200 times the safe
limit for drinking water) occur in the groundwater of a mineralized
residential area near Fairbanks. Bedrock of the area contains 750 ppm
As, primarily as arsenopyrite and scorodite. The oxygen-poor groundwater
is enriched in As(III) and ferrous iron while the surface waters
are iron free and contain less than 50 ppb As(V). Arsenic is removed
from the water by coprecipitation with ferric hydroxide. Some iron-rich
stream sediments contain as much as 1,400 ppm arsenic.
The distribution of arsenic in the groundwater is controlled by the
distribution of arsenic in the bedrock. The arsenic content of the B soil
horizon over mineralized veins is about 150 ppm, while that over barren
rock is 30 ppm. The vegetation over the veins is not significantly
enriched in arsenic.
Lettuce, radishes and tomatoes grown with arsenic-rich water (5 ppm) contain 16, 8 and 1 ppm As, respectively; these amounts are significantly
greater than plants not treated with arsenic.
Preliminary studies by state and federal health agencies show no
detrimental effects on the health of persons drinking these arsenic-rich
waters.The work upon which this publication is based was supported in part by
funds provided by the Office of Water Research and Technology (Project
B-037-ALAS, Agreement No. 14-34-0001-8056), U.S. Department of the
Interior, Washington, D.C., as authorized by the Water Research and
Development Act of 1978
The impact of imidacloprid and the interaction between imidacloprid and pollen scarcity on vitality and hibernation of honey bee colonies
Circular 64
Treatment of Alaska-produced food products by ionizing radiation may
benefit the seafood and agricultural industries and the Alaskan consumer. A
feasibility study to evaluate the potential social and economic benefits and
risks as well as the costs of using the process in Alaska on Alaskan products is being coordinated
by the Institute of Northern Engineering. A research and development project to determine
effects on the quality o f Alaskan products could be the next phase in the introduction o f a new
food-preservation technique
to Alaska
Cloud-Based Data Analytics on Human Factor Measurement to Improve Safer Transport
Improving safer transport includes individual and collective behavioural aspects and their interaction. A system that can monitor and evaluate the human cognitive and physical capacities based on human factor measurement is often beneficial to improve safety in driving condition. However, analysis and evaluation of human factor measurement i.e. demographics, behaviour and physiology in real-time is challenging. This paper presents a methodology for cloud-based data analysis, categorization and metrics correlation in real-time through a H2020 project called SimuSafe. Initial implementation of this methodology shows a step-by-step approach which can handle huge amount of data with variation and verity in the cloud
Deficits in temporal order memory induced by interferon-alpha (IFN-α) treatment are rescued by aerobic exercise
Patients receiving cytokine immunotherapy with IFN-α frequently present with neuropsychiatric consequences and cognitive impairments, including a profound depressive-like symptomatology. While the neurobiological substrates of the dysfunction that leads to adverse events in IFN-α-treated patients remains ill-defined, dysfunctions of the hippocampus and prefrontal cortex (PFC) are strong possibilities. To date, hippocampal deficits have been well-characterised; there does however remain a lack of insight into the nature of prefrontal participation. Here, we used a PFC-supported temporal order memory paradigm to examine if IFN-α treatment induced deficits in performance; additionally, we used an object recognition task to assess the integrity of the perirhinal cortex (PRH). Finally, the utility of exercise as an ameliorative strategy to recover temporal order deficits in rats was also explored. We found that IFN-α-treatment impaired temporal order memory discriminations, whereas recognition memory remained intact, reflecting a possible dissociation between recognition and temporal order memory processing. Further characterisation of temporal order memory impairments using a longitudinal design revealed that deficits persisted for 10 weeks following cessation of IFN-α-treatment. Finally, a 6 week forced exercise regime reversed IFN-α-induced deficits in temporal order memory.
These data provide further insight into the circuitry involved in cognitive impairments arising from IFN-α-treatment. Here we suggest that PFC (or the hippocampo-prefrontal pathway) may be compromised whilst the function of the PRH is preserved. Deficits may persist after cessation of IFN-α-treatment which suggests that extended patient monitoring is required. Aerobic exercise may be restorative and could prove beneficial for patients treated with IFN-α
Recommended from our members
Regulation of Yersina pestis Virulence by AI-2 Mediated Quorum Sensing
The proposed research was motivated by an interest in understanding Y. pestis virulence mechanisms and bacteria cell-cell communication. It is expected that a greater understanding of virulence mechanisms will ultimately lead to biothreat countermeasures and novel therapeutics. Y. pestis is the etiological agent of plague, the most devastating disease in human history. Y. pestis infection has a high mortality rate and a short incubation before mortality. There is no widely available and effective vaccine for Y. pestis and multi-drug resistant strains are emerging. Y. pestis is a recognized biothreat agent based on the wide distribution of the bacteria in research laboratories around the world and on the knowledge that methods exist to produce and aerosolize large amounts of bacteria. We hypothesized that cell-cell communication via signaling molecules, or quorum sensing, by Y. pestis is important for the regulation of virulence factor gene expression during host invasion, though a causative link had never been established. Quorum sensing is a mode of intercellular communication which enables orchestration of gene expression for many bacteria as a function of population density and available evidence suggests there may be a link between quorum sensing and regulation of Y. pesits virulence. Several pathogenic bacteria have been shown to regulate expression of virulence factor genes, including genes encoding type III secretion, via quorum sensing. The Y. pestis genome encodes several cell-cell signaling pathways and the interaction of at least three of these are thought to be involved in one or more modes of host invasion. Furthermore, Y. pestis gene expression array studies carried out at LLNL have established a correlation between expression of known virulence factors and genes involved in processing of the AI-2 quorum sensing signal. This was a basic research project that was intended to provide new insights into bacterial intercellular communication and how it is used to regulate virulence in Y. pestis. It is known that many bacteria use intercellular signaling molecules to orchestrate gene expression and cellular function. A fair amount is known about production and uptake of signaling molecules, but very little is known about how intercellular signaling regulates other pathways. Although several studies demonstrate that intercellular signaling plays a role in regulating virulence in other pathogens, the link between signaling and regulation of virulence has not been established. Very little work had been done directly with Y. pestis intercellular signaling apart from the work carried out at LLNL. The research we proposed was intended to both establish a causative link between AI-2 intercellular signaling and regulation of virulence in Y. pestis and elucidate the fate of the AI-2 signaling molecule after it is taken up and processed by Y. pestis. Elucidating the fate of AI-2 was expected to lead directly to the understanding of how AI-2 signal processing regulates other pathways as well as provide new insights in this direction
Jaarrond bestrijden Varroamijt vermindert wintersterfte
Alweer over wintersterfte en varroa? Jazeker, en wel over twee onderzoeken waaraan imkers meewerkten als citizen scientists (burger-wetenschappers). In dit artikel doen we verslag van het Nederlands BijenvolkOnderzoek (NBO), van Bijen@wur en het Nederlands Centrum voor Bijenonderzoek samen, en van het Bijen@wur-Demonstratieproject Varroabestrijding. Beide onderzoeken laten zien dat een jaarrond varroabestrijding helpt de wintersterfte terug te dringen. Met dank aan een aantal van u die deze projecten hielpen uitvoeren
Hoeveel stuifmeel zit er in honing?
In honing zit altijd wat stuifmeel (en ook wat nectar in het bijenbrood). Bijen@wur zocht uit; "Hoeveel dan?
Demonstratieproef varroabestrijding en wintersterfte (mei 2012 – juli 2013)
Deze demonstratieproef is opgezet als een Citizen Scientist (CS) project waarbij het praktische veldwerk en de waarnemingen, op aanwijzing van en gecoördineerd door PRI bijen@wur, uitgevoerd werden door bijenhouders. De analyses, interpretatie van de data en de rapportage zijn uitgevoerd door PRI bijen@wur. Voor de demonstratieproef 2012-2013 is aan 25 bijengezondheidsscoördinatoren (BGC’rs) gevraagd de varroabestrijding uit te voeren volgens de PRI bijen@wur brochure “Effectieve bestrijding van varroa”
- …