Showing papers by "University of Bedfordshire published in 1987"

New species of Pseudocercospora and Mycovellosiella, and new combinations into Pseudocercospora and Phaeoramularia

Abstract: Thirteen new species are described and figured: Pseudocercospora abri and Mycovellosiella pirozynskii on Abrus canescens, Pseudocercospora urariicola and P. indica on Uraria picta, P. desmodii-salicifolii on Desmodium salicifolium, P. violae on Viola sp., P. homalanthi on Homalanthus novoguineensis, P. cynometrae on Cynometra leonensis, P. hymenocardiae on Hymenocardia heudelotii, P. harunganae on Harungana madagascariensis, P. njalaensis on Chlorophora regia, P. acanthi on Acanthus guineensis , and P. allophylicola on Allophylus africanus . Redescriptions and figures are given of Pseudocercospora allophyli (Hansf.) comb. nov. on Allophylus sp. and Phaeoramularia acanthicola (Hansf.) comb.nov. on Acanthus arboreus . Thirty-six more new combinations from Cercospora into Pseudocercospora are proposed. After further consideration it is concluded that Cercoseptoria cannot satisfactorily be distinguished from Pseudocercospora , and a further ten new combinations into the latter genus are therefore made.

Structural identity between the iron- and manganese-containing superoxide dismutases.

Abstract: We have recently reported the first complete amino acid sequence of an iron-containing superoxide dismutase. The iron enzyme is thought to be closely homologous to the manganese-containing superoxide dismutases. The availability of complete amino acid sequence information for four manganese superoxide dismutases and the crystal structures for two iron and two manganese superoxide dismutases prompted us to investigate the degree of homology between the two proteins at various levels. We report that it is not possible to clearly distinguish the two proteins on the basis of their secondary or tertiary structures. It would appear that a small number of single site substitutions are responsible for conferring distinguishing properties between the two proteins. Substitution of glycine 77 and glutamine 154 by a glutamine and an alanine respectively in Photobacterium leiognathi iron superoxide dismutase may distinguish the kinetic and other particular properties of this protein from the manganese protein (and other iron superoxide dismutases). Furthermore the primary structure of both the iron and manganese proteins does not appear to have any homology with any other known amino acid sequence.

Interactions between Globodera pallida juveniles, Verticillium dahliae and three potato cultivars, with descriptions of associated histopathologies

Abstract: Experiments carried out in agar culture showed that the potato cultivar Pentland Javelin is relatively resistant to infection by Verticillium dahliae because it has a multilayered cortex of thick-walled cells, each producing lignituber appositions to invading hyphae. Its thick-walled xylem vessels are difficult to penetrate, its large vessel lumens difficult to obstruct, and its ability to produce tyloses limits the spread of the fungus, By comparison. Maris Anchor roots have fewer cortical layers and very small xylem vessels which are more easily blocked by hyphae. Maris Peer is intermediate in both the number of cortical cell layers and the size of xylem vessels. Globodera pallida juveniles assist V. dahliae to evade the natural defences of the root by opening an invasion channel for the fungus. In Maris Anchor and Maris Peer, but not in Pentland Javelin, the nematode provokes a widespread hypersensitive response; the resulting cell wall lignification impedes the growth of those hyphae which invade several days after the nematode. Hyphae grow well in syncytia and this enhances the probability of their penetrating xylem vessels. Although V. dahliae is generally held to induce symptoms through xylem blockage, the phloem colonization which was noted may affect the growth of both plant and nematode through its effect on assimilate movement towards root lips and into syncytia.

Yield Distribution in Irrigated tea (Camellia Sinensis) at Two Sites in Eastern Africa

Abstract: The results of two tea irrigation experiments conducted independently in southern Tanzania and Malawi, where severe annual droughts of similar duration occur, were compared. There were marked differences in the dry season yield distributions between the two sites. These could be attributed to the adverse effects of large saturation deficits on plant water status and rates of shoot extension in Malawi. The implications for tea irrigation in particular and for irrigation agronomy experiments in general are discussed. The need to include detailed descriptions of the environment in which experiments are conducted is stressed.

Non-slip floor mat combination

Abstract: A non-slip floor mat combination for use on pile-carpeted surfaces comprises a flexible, rubber-backed mat having a substantially flat preferably ultra smooth backing surface, and an anchoring component designed to be detachably secured through its lower surface to pile carpeting and having a substantially flat preferably ultra smooth upper surface designed to contact the backing surface of the mat and to restrict lateral movement of the mat relative to the anchoring component solely due to frictional resistance to relative movement between the two substantially flat surfaces in contact with one another.

Coloured hydrogel objects and their production

Abstract: Shaped organic polymer hydrogels, especially contact lenses, are provided with opaque or translucent colouring so as to be capable of masking effectively any underlying colour, e.g. the natural colour of the eye. The hydrogel may be rendered opaque by precipitation in situ of a white or yellow water-insoluble, inorganic or organic material e.g. barium sulphate or an optical brightener and then coloured with a suitable dyestuff.

Occupancy detectors etc.

Abstract: Fixing an object (1) such as a presence sensor housing in an aperture (15) in a barrier member (16) so done by a securement device (8) of resilient spring form that fits to and grips part of the object (1) protruding through the barrier member (16). The spring member (8) can be flexed ut of gripping of the protruding part of the object (1) to be moved up to the barrier (16) then allowed to relax in achieving gap-free mounting. Specifically, flexing is of an arcuate part (11) having an object gripping aperture (14) using angled parts (12,13) presenting bends (12a,13a) able to butt up to the barrier (16).

Cable stripping tool

Abstract: A tool fragmentarily shown in Figure 3 has outer gripping jaws 12, 19 to grip a cable 20, and inner jaws with cutting edges 30 which penetrate the cable. The inner jaws are initially located in the chain dot position for sheath penetration and are then displaced axially to strip the cut portion of the sheath of the core of the cable. In the axial movement the inner jaws are guided along tracks on the adjacent faces of the outer jaws and at least one of these tracks 100 is relieved at 102 so that during the axial movement the cutting jaws separate. This enables the tool to operate satisfactory even when the jaws converge towards the axis on which they are pivoted.

Pseudocercospora carpentariae sp.nov.

Abstract: Pseudocercospora carpentariae sp. nov. is described on the palm Carpentaria in Australia.

Images, ceramic floors and Warden Abbey

Abstract: Excavations in 1974 at Warden Abbey in Bedfordshire, a major Cistercian house in the south of England, uncovered paving of exceptional beauty and interest. Post excavation analysis has produced new and detailed information about medieval tilers’ techniques. Remnants of complex and highly decorated ceramic pictures alter previous conceptions of tiling as a humble craft, raising it to an art form. A craftsman's code incised on the normally hidden faces of the tiles informs us that their creators were not merely ingenious but literate and numerate to an advanced degree.

Cutting machines and method of controlling the cutting horizon

Abstract: A cutting machine including a base, a cutter movably mounted on the base, and a drive for moving the cutter reciprocably along the base to carry out a cutting operation. The cutter height relative to the base is alterable by a ram and the base includes a controller for controlling the height of the cutter to set a desired height of the cutter relative to the base as the cutter passes the controller.

Climate control systems and equipment — building design, ventilation and air cleaning

Abstract: The design of a building affects control of climate in several ways. Its thermal insulation can be impaired by inadequate thickness of insulating material, faulty installation, settling, condensation and destruction by vermin and insects. Also its design interacts with the ventilation system which must take into account not only location, size and shape of the building, but also details such as air leakage, deflection of air jets by obstructions and dimensional changes such as occur in a timber structure. In contrast, a smooth or rough surface can respectively enhance or impede the throw of a jet as required. A permeable floor in a building may help to remove sedimented dust.A ventilation system needs to be matched to the class of livestock. Systems can be classified and described, namely, glass-fibre ceiling, high-speed jet, polythene ducts, recirculation (both damper and twin fans), hybrid (two systems combined), down-jet, Udiflo tent, and automatically controlled natural ventilation. Cyclical timing of fans gives close control of very low ventilation rates for batch rearing. Kennelled accommodation needs improved control for stock and stockman.It may be possible to reduce dust by optimizing the many factors listed that predispose towards lower dust levels. An alternative solution is to use an internal air cleaner. This can be an electrostatic precipitator, a wet scrubber or a dry filter. The latter appears to be the most appropriate and a design that discharges filtered air downwards at a speed of 0–4 m/s towards the stock has been developed and tested in a flat-deck piggery.

Fluid flow control system

Abstract: A fluid flow control system includes a valve, in which a control element regulates flow through a metering orifice A further control element regulates flow through an orifice downstream of the orifice and is responsive to the pressure downstream of the orifice and to an opposing control pressure on a line The element is positioned in accordance with the pressure in a chamber controlled by an electrical valve The pressure in line is set to provide a required pressure drop across the orifice

An Enzymatic Technique for the Separation of Spicules from Alcohol-Preserved Sponge Tissue

Abstract: After removing the alcohol from fragments of preserved specimens of the sponge Suberites domuncula, it is possible to free spicules from the material by digesting it with pepsin or trypsin. Sections cut from such alcohol- preserved specimens which have been embedded in wax are also susceptible to digestion by these enzymes after the tissue has been taken down to water. The hydrolysis leaves intact some slender fibrous connections which unite some of the megascleres at the surface of the sponge.

Optical effects projector

Abstract: of EP0240355An optical effects projector comprising a stroboscopic light source (3) and a projection lens (2), and flash triggering circuitry for operating the light source at a flash rate of less than fifteen flashes per second. The projector may have an elliptical reflector support behind the light source carrying a plurality of discrete reflectors, or may comprise a gate (4) for receiving image materials such as an effects wheel (8) or film strip for projection.