Foliar nematode,Litylenchus crenatae ssp. mccannii,population dynamics in leaves and buds of beech leaf disease‐affected trees in Canada and the US

A foliar nematode, Litylenchus crenatae ssp. mccannii, is associated with beech leaf disease (BLD) symptoms. Information about the types of tissues parasitized and how nematode populations fluctuate in these tissues over time is needed to improve surveys as well as understand the nematodes role in BLD. During this study, the nematode was detected throughout the known range of BLD by researchers at both Canadian and US institutions using a modified pan method to extract nematodes. Monthly collections of symptomatic and asymptomatic leaves during the growing season (May–October), and leaves and buds between growing seasons (November–March), revealed that nematodes were present in all tissue types. Progressively larger numbers of nematodes were detected in symptomatic leaves from Ohio and Ontario, with the greatest detections at the end of the growing season. Smaller numbers of nematodes were detected in asymptomatic leaves from BLD‐infected trees, typically at the end of the growing season. The nematode was detected overwintering in buds and detached leaves. The discovery of small numbers of nematodes in detached leaves at one location before BLD was detected indicates that nematodes may have been present before disease symptoms were expressed. Other nematodes, Plectus and Aphelenchoides spp., were infrequently detected in small numbers. Our findings support the involvement of the nematode in BLD and indicate that symptoms develop only when certain requirements, such as infection of buds, are met. We also found that the nematode can be reliably detected in buds and leaves using the modified pan extraction method.     

Body-centered cubic iron-nickel alloy in Earth's core

Cosmochemical, geochemical, and geophysical studies provide evidence that Earth's core contains iron with substantial (5 to 15%) amounts of nickel. The iron-nickel alloy Fe(0.9)Ni(0.1) has been studied in situ by means of angle-dispersive x-ray diffraction in internally heated diamond anvil cells (DACs), and its resistance has been measured as a function of pressure and temperature. At pressures above 225 gigapascals and temperatures over 3400 kelvin, Fe(0.9)Ni(0.1) adopts a body-centered cubic structure. Our experimental and theoretical results not only support the interpretation of shockwave data on pure iron as showing a solid-solid phase transition above about 200 gigapascals, but also suggest that iron alloys with geochemically reasonable compositions (that is, with substantial nickel, sulfur, or silicon content) adopt the bcc structure in Earth's inner core.     

Protection of mice against the Lyme disease agent by immunizing with recombinant OspA

Lyme borreliosis is a tick-borne illness caused by Borrelia burgdorferi. The gene for outer surface protein A (OspA) from B. burgdorferi strain N40 was cloned into an expression vector and expressed in Escherichia coli. C3H/HeJ mice actively immunized with live transformed E. coli or purified recombinant OspA protein produced antibodies to OspA and were protected from challenge with several strains of B. burgdorferi. Recombinant OspA is a candidate for a vaccine for Lyme borreliosis.     

An update on bovine tuberculosis programmes in Latin American and Caribbean countries

Of the approximately 374 million cattle in Latin America and the Caribbean, 70% are held in areas where rates of Mycobacterium bovis infection in cattle are higher than 1%. The remaining 30% are in countries where infection affects less than 1% of cattle, including 62 million in countries where bovine tuberculosis infection is virtually nil. Measures for controlling bovine tuberculosis are partially or extensively applied in most of the countries in the Region. These measures are based on test and slaughter, notification, post-mortem inspection and surveillance in slaughterhouses. A coordinated production, standardization and quality control of purified protein derivatives is urgently required for use in control and eradication campaigns in order to assure reliability of reagents and comparability of data on tuberculin testing within the Region. On the basis of information from Argentina, M. bovis is estimated to cause 2% of all human cases of tuberculosis in the Region. Slaughterhouse and dairy farms workers are most-frequently infected, with infection occurring via the respiratory tract. Various in vitro assays for the diagnosis of bovine tuberculosis have been developed and/or assessed in the Region, and DNA fingerprinting has been applied for a comprehensive understanding of the epidemiology of bovine tuberculosis at the local and regional level.     

<Emphasis Type="Italic">Samardala</Emphasis>: specificities and changes in the ethnobotanical knowledge about <Emphasis Type="Italic">Allium siculum</Emphasis> subsp<Emphasis Type="Italic">. dioscoridis</Emphasis> (Sm.) K. Richt. in Bulgaria

Allium siculum Ucria is a perennial bulbous plant that occurs in Bulgaria as A. siculum subsp. dioscoridis (Sm.) K. Richt. The plant is locally known as “samardala”. Its herbage is used traditionally by local communities in Bulgaria as edible green and for preparation of salty spice mixtures. The study was focused on the documentation of traditional knowledge about samardala, covering local collection and cultivation practices, processing methods and consumption preferences. The respondents (aged 30–86 years, 50% over 65) were local producers and small-scale salesmen of the herbage and samardala-containing spices. To assess the health features of samardala spices the total phenol and flavonoid content was measured in home-consumed or marketed flavoured salts. Overall appreciation of the plant and related food products was found to be very high; presenting a considerable engagement of the locals in plant cultivation and gathering, laborious processing and consumption. Traditional ecological knowledge about the biology, phenology and ecology of the samardala plant and methods for its processing is still preserved by elderly people who rely mostly on their own cultivated plants. Although the introduction of modern appliances has altered the method of production, its main stages and the recipes are preserved. Modernization of the processing method has not affected the quality of the products and faster processing could be a contributing factor for the higher content of biologically active substances. Phenolic content was about twice as low as the flavonoid content, following the same pattern for all tested flavoured salts. Measures for better management of natural populations and promotion of cultivation practices of A. siculum subsp. dioscoridis would ensure the sustainable quality of traditional products as well as conservation of the natural plant resources.     

Forest farming of wine-cap <Emphasis Type="Italic">Stropharia</Emphasis> mushrooms

Cultivation of the wine-cap Stropharia mushroom (Stropharia rugoso-annulata Farlow ex. Murrill) has potential as a forest farming practice in agroforestry. Two outdoor cultivation experiments were established in central Missouri during 2006. We examined Stropharia production in response to two substrate/casing systems: (1) an uncased mixture of lightly composted poplar wood chips and soil, without casing; and (2) leached and partially fermented wheat straw cased with the same chip/soil mixture. We also examined the effect of soil contact (presence/absence of water-permeable fabric), and inoculation season (mid versus late summer) over two field seasons. Mushroom production during both seasons (2006 and 2007) was greater from the straw/chips system than from the wood chip system. The use of ground-cover fabric did not enhance mushroom production. Further research is needed to determine the most productive dimensions of cultivation beds, to evaluate alternative casing methods, and to explore the possibility of cultivation bed renewal with fresh substrate.     

Dispersal of Contaminant Metals in the Mining-Affected Danube and Maritsa Drainage Basins, Bulgaria, Eastern Europe

Metal dispersal in the Danube and Maritsa drainage basins resulting from metal mining activities in Bulgaria has been assessed through the collection of 611 samples of river water, river channel and floodplain sediment, and mine waste from over 218 sites. Concentrations of Cd, Cu, Pb, and Zn in river water were found to be highest in close proximity to locations of Cu and Pb–Zn mining regions in the Maritsa catchment. Downstream dispersal of solute metals in these catchments, and into the River Danube, was found to be limited by physical dilution and a well-buffered pH environment. Dispersal of contaminant metals in channel and floodplain sediment was found to be extensive. Contamination was particularly severe in the Rivers Timok and Iskar (Danube catchment) and the Topolnitsa, Chepelarska, and Arda Rivers (Maritsa catchment) and creates the potential of transboundary dispersal of contaminant metals.     

Reciprocal cellular and humoral immune responses in bovine tuberculosis

A sandwich ELISA for the detection of gamma interferon showed higher sensitivity and specificity than an indirect ELISA for mycobacterial antibodies in the diagnosis of bovine tuberculosis. Circumstantial evidence of an inverse relationship between cellular and humoral immune responses to Mycobacterium bovis was found in cattle with natural infection.