Growth and Nutrient Status of Quercus rubra L. in Response to Al and Ca

Northern red oak (Quercus rubra L.) seedlings were grown for63 d in a complete nutrient solution (pH 3.8) containing oneof three concentrations of Al (0, 0.75 or 2-0 mol m^–3)and either 10 or 250 mmol m^–3 Ca. Of all solution variables,the In of (Al³⁺)/(Ca²⁺), the solution activities ratio, wasmost closely correlated with declines in shoot and root growth.Ln (Al³⁺)/(Ca²⁺) also most closely predicted leaf and root [Mg],[Al], and [Al]/[Ca]. These three variables in turn were closelyrelated to growth. Toxic levels of (Al³⁺) and (Al³⁺)/(Ca²⁺)in solution are compared to levels in forest soils. Key words: Al phytotoxicity, Al x Ca interaction, Quercus rubra     

COMPARISON of ANALYTICAL SENSITIVITIES of THREE ENZYME IMMUNOASSAY PROCEDURES FOR the DETECTION of SALMONELLA LIPOPOLYSACCHARIDE

The analytical sensitivities of three different enzyme linked immunoassays (ELISA), two competitive and a capture format were assessed. the assay systems employed monoclonal antibodies to Salmonella lipopolysaccharide (LPS) outer core epitopes to detect crude LPS antigens from Salmonella typhimurium. the most sensitive ELISA was the capture procedure, being capable of detection 1.3 ng/ml of LPS. This technique, however also gave the greatest between-test variation and as a result, the lowest amount that could be detected with a 95% confidence limit was actually 12.8 ng/ml and it took the longest time to perform (3 h, 30 min). A competitive ELISA using limiting monoclonal antibody to compete between solid phase antigen and soluble antigen in the sample, ranked second in sensitivity, and can detect 2.8 and 3.8 ng/ml of LPS when tested with two different monoclonal antibodies. However, because of the slight between test variation, the actual sensitivities that could be detected with a 95% confidence limit were 3.1 and 4.6 ng/ml, respectively. This test takes approximately 1 h and 30 min to perform.
The classical type of competitive assay, employing a labelled antigen, was the least sensitive being capable of detecting 5.8 ng/ml if the LPS was conjugated with horseradish peroxidase and 16.0 ng/ml if alkaline phosphatase was used as a label. to account for the between-test variation, the sensitivities with a 95% confidence limit were 8.6 and 18.7 ng/ml for the respective assays, which take 2 h and 15 min to perform.
These sensitivities compare favorably with those published for similar assays, but all of the procedures were judged insufficiently sensitive for direct use on food samples to be tested for the presence of Salmonella species. However, the assays would be quite suitable for demonstration of Salmonella sp. after an enrichment procedure.     

Biomass: Is it a useful tool in paleocommunity reconstruction?

In general, more of the biomass of the community is preserved than is its numerical abundance. Thus, the paleontologist, on the average, works with more of the community when biomass is used. Community characteristics such as taxon dominance and habitat proportions are at least as accurately derived from biomass as numerical abundance. The use of biomass is clearly more appropriate in describing energy flow and trophic proportions. Whenever possible, biomass should be used as a complement to numerical abundance in future paleoecologic reconstructions.     

Isolation of fungal DNA from plant tissues and removal of DNA amplification inhibitors

Specific primers and the polymerase chain reaction (PCR) are increasingly used for detection of fungi in plants. Detection depends on isolation of DNA that is free of compounds that inhibit amplification. We report on the significance of inhibition in soybean stems with a focus on studies of the vascular fungal pathogen Phialophora gregata. A simple DNA extraction procedure based on a FastDNA® kit is described that allows consistent detection of fungi in soybean stems using PCR. The addition of polyvinylpyrrolidone and supplemental DNA purification steps overcame inhibition in over 90% of samples. These methods should also facilitate studies with other plant and fungal species.     

Effectiveness of Vaginal-Implant Transmitters for Locating Elk Parturition Sites

ABSTRACT We assessed success of vaginal implant transmitters (VITs), deployed in 198 elk (Cervus elaphus nelsoni), in locating elk calving sites in western Wyoming, USA, in 2006–2007. We identified 60.3% of expelled VIT locations as definite or probable event markers and an additional 21.8% as possible event markers. Failure rate for VITs was 10.6%, and we found an additional 7.3% in improbable or impossible parturition sites. Vaginal implant transmitters were effective in locating calving and abortion sites and will facilitate definition of parturition habitat selection and parturition ranges of specific subpopulations.     

Natural hybridization between Vanilla claviculata (W.Wright) Sw. and V. barbellata Rchb.f. (Orchidaceae): genetic, morphological, and pollination experimental data

Vanilla claviculata (W.Wright) Sw. and K barbellata Rchb.f. grow sympatrically in the southwestern part of herto Rico. At three localities in the range of the two species, individuals with flowers that appeared Merent from previously known species were found. To test whether these were hybrids between V. claviculata and V. barbellata , 11 morphological floral characters were recorded at seven populations and allozyme profiles of the three taxa compared. Principal component analysis on the morphological characters gave three distinct groups with minor overlaps. The first component axis reflects variation in overall size of the flowers, while the second component reflects variation in the size of the distal aperture of the labellum. Allozyme data revealed that the putative hybrids have a significant surplus of heterozygotes ( F _IS = - 0.65) as expected in a F ₁ generation. Both data sets support the hypothesis that the individuals are hybrids, which is further augmented by interspecific pollination experiments between the putative parental species. This is the first case of natural hybridization reported in the genus Vanilla .     

Mobility is related to species traits in noctuid moths

1. Mobility is important for the understanding of how species survive in fragmented landscapes and cope with increasing rates of habitat and climate change. However, mobility is a difficult trait to explore and is poorly known in most taxa. Species traits have been studied in relation to range shifts, extinction risks, and responses to habitat area and isolation, and have also been suggested as good estimators of mobility. Here we explore the relation between mobility and species traits in noctuid moths. 2. We sampled noctuid moths by an automatic light‐trap on an island far out in the Baltic Sea. We compared traits of the non‐resident species on the island with traits of a species pool of assumed potential migrants from the Swedish mainland. 3. Mobility was significantly related to adult activity period, length of flight period, and the interaction between host‐plant specificity and distribution area. Widely distributed host‐plant generalists were more mobile than host‐plant specialists with more restricted distribution, and species with an adult activity period in August to September moved to the island to a higher extent than species with an adult activity period in May to July. Our results remained qualitatively robust in additional analyses, after controlling for phylogeny and including all species recorded on the island, except for the trait ‘length of flight period’. 4. Our results highlight the importance of the relation between mobility and species traits. Noctuid moths with certain traits move over longer distances than earlier known. This finding is important to include when predicting range dynamics in fragmented and changing landscapes, and when conservation measures of species are devised.     

Soft‐tissue imprints in fossil and Recent cephalopod septa and septum formation

Several soft‐tissue imprints and attachment sites have been discovered on the inside of the shell wall and on the apertural side of the septum of various fossil and Recent ectocochleate cephalopods. In addition to the scars of the cephalic retractors, steinkerns of the body chambers of bactritoids and some ammonoids from the Moroccan and the German Emsian (Early Devonian) display various kinds of striations; some of these striations are restricted to the mural part of the septum, some start at the suture and terminate at the anterior limit of the annular elevation. Several of these features were also discovered in specimens of Mesozoic and Recent nautilids. These structures are here interpreted as imprints of muscle fibre bundles of the posterior and especially the septal mantle, blood vessels as well as the septal furrow. Most of these structures were not found in ammonoids younger than Middle Devonian. We suggest that newly formed, not yet mineralized (or only slightly), septa were more tightly stayed between the more numerous lobes and saddles in more strongly folded septa of more derived ammonoids and that the higher tension in these septa did not permit soft‐parts to leave imprints on the organic preseptum. It is conceivable that this permitted more derived ammonoids to replace the chamber liquid faster by gas and consequently, new chambers could be used earlier than in other ectocochleate cephalopods, perhaps this process began even prior to mineralization. This would have allowed faster growth rates in derived ammonoids.