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Small Cages (small + cage)

Distribution by Scientific Domains

Life Sciences	50%
Chemistry	50%

Selected Abstracts

Behavioural changes in Schistocerca gregaria following infection with a fungal pathogen: implications for susceptibility to predation

ECOLOGICAL ENTOMOLOGY, Issue 3 2001
Steven Arthurs
Summary 1. Field observations have indicated that infection of locusts and grasshoppers by the fungal entomopathogen Metarhizium anisopliae var. acridum may result in a substantial increase in the host's susceptibility to predation, before death is caused directly by the disease. 2. Laboratory experiments were conducted to examine how the behaviour of the desert locust Schistocerca gregaria Forskål changes following infection by M. anisopliae var. acridum to explore some potential mechanisms underlying this phenomenon. 3. In the first experiment, which involved monitoring general locust activity in small cages throughout the disease incubation period, infected locusts were observed to increase locomotion and bodily movement from 3 days after infection until death (average survival time of 11 days). There was some evidence of reduced feeding and mating behaviour following infection. 4. In a second experiment, locusts were exposed individually to a simulated predator attack and the initiation and strength of any escape responses were measured. Infected locusts were observed to have a reduced escape capability (both the propensity to escape and the strength of the response). In contrast to the relatively early changes in general activity observed in the first experiment, this was only apparent at the late stages of infection shortly before death. 5. Both an increase in movement and general apparency early in the infection process, and reduced escape capability late on, suggest mechanisms whereby the susceptibility of locusts and grasshoppers to predation might be enhanced following infection with M. anisopliae var. acridum. [source]

Structure and composition of CO2/H2 and CO2/H2/C3H8 hydrate in relation to simultaneous CO2 capture and H2 production

AICHE JOURNAL, Issue 6 2009
Rajnish Kumar
Gas hydrates from a (40/60 mol %) CO2/H2 mixture, and from a (38.2/59.2/2.6 mol %) CO2/H2/C3H8 mixture, were synthesized using ice powder. The gas uptake curves were determined from pressure drop measurements and samples were analyzed using spectroscopic techniques to identify the structure and determine the cage occupancies. Powder X-ray diffraction (PXRD) analysis at ,110°C was used to determine the crystal structure. From the PXRD measurement it was found that the CO2/H2 hydrate is structure I and shows a self-preservation behavior similar to that of CO2 hydrate. The ternary gas mixture was found to form pure structure II hydrate at 3.8 MPa. We have applied attenuated total reflection infrared spectroscopic analysis to measure the CO2 distribution over the large and small cavities. 1H MAS NMR and Raman were used to follow H2 enclathration in the small cages of structure I, as well as structure II hydrate. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Lipid-enhanced pollen and lipid-reduced flour diets and their effect on the longevity of honey bees (Apis mellifera L.)

AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2007
Rob Manning
Abstract, As eucalypt pollens contain low concentrations of lipid, enhancing pollen diets with fatty acids was hypothesised to improve honey bee longevity. Different concentrations of linoleic and oleic acid added to eucalypt pollen were trialled in small cages containing approximately 1400 bees each. Bees fed diets of redgum (Corymbia calophylla (Lindl.) Hill & Johnson, formerly Eucalyptus calophylla) pollen had the lowest mortality of 22 diets tested for 6 weeks and had life spans (50%) greater than 42 days. Linoleic acid mixed with a redgum diet in concentrations >6% corresponded to life spans of 24,25 days. Bee longevity appeared to be more sensitive to oleic acid as life spans decreased to 15,21 days when diets had concentrations >2%. The life spans of bees fed soya bean flour were 26 days on low (0.6% lipid) fat, 19 days on defatted and 20 days on full-fat diets. Bees fed lupin flour had a life span of 23 days. Adding redgum pollen to lupin flour caused increased mortality, but addition of pollen to soya bean flour was beneficial. Thus, beekeepers who choose to utilise soya bean or lupin flours as protein substitutes to pollen will have bees with reduced longevity. Bees fed redgum pollen that had been dried, crushed, irradiated and hermetically stored in a cool room for several years had similar longevity to bees fed fresh-collected and frozen redgum pollen. [source]

Hydrogen in Porous Tetrahydrofuran Clathrate Hydrate

CHEMPHYSCHEM, Issue 9 2008
Fokko M. Mulder Dr.
Abstract The lack of practical methods for hydrogen storage is still a major bottleneck in the realization of an energy economy based on hydrogen as energy carrier.1 Storage within solid-state clathrate hydrates,2,4 and in the clathrate hydrate of tetrahydrofuran (THF), has been recently reported.5,,6 In the latter case, stabilization by THF is claimed to reduce the operation pressure by several orders of magnitude close to room temperature. Here, we apply in situ neutron diffraction to show that,in contrast to previous reports[5,,6],hydrogen (deuterium) occupies the small cages of the clathrate hydrate only to 30,% (at 274 K and 90.5 bar). Such a D2 load is equivalent to 0.27 wt.,% of stored H2. In addition, we show that a surplus of D2O results in the formation of additional D2O ice Ih instead of in the production of sub-stoichiometric clathrate that is stabilized by loaded hydrogen (as was reported in ref. 6). Structure-refinement studies show that [D8]THF is dynamically disordered, while it fills each of the large cages of [D8]THF,17D2O stoichiometrically. Our results show that the clathrate hydrate takes up hydrogen rapidly at pressures between 60 and 90 bar (at about 270 K). At temperatures above ,220 K, the H-storage characteristics of the clathrate hydrate have similarities with those of surface-adsorption materials, such as nanoporous zeolites and metal,organic frameworks,7,,8 but at lower temperatures, the adsorption rates slow down because of reduced D2 diffusion between the small cages. [source]