Rupture of the Vinculum in Association with Tendon Injury within the Digital Flexor Tendon Sheath in Two Horses

The following report documents an unusual anatomical finding in two cases of aseptic tenosynovitis of the digital flexor tendon sheath. Disruption of the vinculum attachment between the palmar/plantar border of the superficial digital flexor tendon and the adjacent palmar/plantar annular ligament was identified in combination with other tendon pathology within the digital flexor tendon sheath. This tenoscopic finding has not been described previously in the literature.     

Xanthomonas translucens from Small Grains: Diversity and Phytopathological Relevance

ABSTRACT Sixty-eight presumptive Xanthomonas translucens strains isolated from 15 small grains or grass species were studied by pathogenicity tests on barley, bread wheat, oat, and bromegrass species, and also by AFLP, analysis of fatty acid methyl esters (FAME), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of protein extracts. The X. translucens strains were divided into three pathogenicity types based on differences observed on barley and bread wheat. Two unspeciated strains producing atypical symptoms formed a fourth pathogenicity type. Pathogenicity on oat and bromegrass species varied within these types. Clusterings observed by AFLP analysis and, to a lesser extent, by FAME analysis were consistent with these pathogenicity groupings. The current results, as well as those of previous restriction fragment length polymorphism analyses of the same strains, support the recent reclassification of X. translucens pv. translucens and X. translucens pv. hordei as true synonyms. X. translucens pv. cerealis, X. translucens pv. translucens, and X. translucens pv. undulosa cluster in different groups by AFLP and FAME analyses. Even though distinction by simple biochemical tests is not clear-cut, the data indicate that the pathovars cerealis, translucens, and undulosa correspond to true biological entities.     

Growth, cold-hardiness, protein content, and digestibility of 70 Leucaena seedlots on three sites in Texas, USA

Seventy seedlots of Leucaena leucocephala, L. pallida, L. diversifolia, L. retusa, L. esculenta, L. confertifolia, L. greggii and L. pulverulenta and various hybrid combinations were examined for survival to freezing weather, biomass production, leaf protein content and in vitro dry matter digestibility in Texas. Three sites along a 600 km north-south transect were chosen to provide a wide range in exposure to freezing weather. The minimum temperature on the warmer Three Rivers site was −7 °C while the minimum temperatures on the colder Vernon site was −14 °C. At the Three Rivers site where −7 °C temperatures occurred and where forage production was a priority and some winter frost damage was not a problem, L. leucocephala K636 and hybrids containing L. diversifolia and L. pallida have the most promise. If total lack of damage to −7 °C is essential, species such as L. retusa, L. pulverulenta (seedlot 61, 62) and hybrids such as L. retusa × L. greggii (53) and L. retusa × L. pulverulenta (55) have the greatest potential. This study examined only one family from each of the cold-hardy species as a parent in the promising hybrids. As extensive intraspecific genetic variation is present within these leucaena species there is great potential to find hybrids with much better combinations of cold hardiness, forage production, leaf protein and dry matter digestibility. This revised version was published online in June 2006 with corrections to the Cover Date.     

Femtosecond dynamics of electron localization at interfaces

The dynamics of two-dimensional small-polaron formation at ultrathin alkane layers on a silver(111) surface have been studied with femtosecond time- and angle-resolved two-photon photoemission spectroscopy. Optical excitation creates interfacial electrons in quasi-free states for motion parallel to the interface. These initially delocalized electrons self-trap as small polarons in a localized state within a few hundred femtoseconds. The localized electrons then decay back to the metal within picoseconds by tunneling through the adlayer potential barrier. The energy dependence of the self-trapping rate has been measured and modeled with a theory analogous to electron transfer theory. This analysis determines the inter- and intramolecular vibrational modes of the overlayer responsible for self-trapping as well as the relaxation energy of the overlayer molecular lattice. These results for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes.     

Dispersion and migration of fine particles in two palygorskite‐containing soils of the Jordan Valley

Migration of different mineral particles within columns of soil‐sand mixtures containing 10 or 20 mass % of soil was investigated by establishing differences in the mineral suite between the ”︁bulk clay” and the ”︁mobile fine material” fractions. The ”︁bulk clay” fractions of all soils contained smectite, palygorskite, kaolinite, quartz, feldspar, and calcite. The soils were saturated with sodium by leaching with NaCl solution, and then leached with distilled water. Clay dispersion and particle migration occurred in the columns. Values of SAR (sodium adsorption ratio) of the effluent decreased with time due to carbonate dissolution. At a certain SAR value, the clays apparently formed aggregates, and as a consequence particle migration stopped in the column. In addition to clay‐sized particles (< 2 μm), very‐fine‐silt‐sized particles (2— 5 μm) were able to migrate in the soil‐sand mixtures, too, and to some extent fine‐silt‐sized particles (5—10 μm) as well. Average size of mobile particles decreases with increase of soil content in the soil‐sand mixtures. The mineralogical composition of the ”︁mobile fine material” changed during the experiment. At the beginning of the experiment, the ”︁mobile fine material” was enriched in the non‐phyllosilicates (especially in calcite, and in some cases in quartz, feldspar and dolomite) and contained low concentrations of phyllosilicates (smectite, palygorskite and kaolinite). At the end of the experiment, the proportion of non‐phyllosilicates decreased, and as a consequence, the proportion of phyllosilicates increased. Among the non‐phyllosilicates, calcite was the most mobile mineral. Among the phyllosilicates, palygorskite was preferentially mobilized in topsoil horizons. In subsoil horizons, on the other hand, kaolinite was preferentially mobilized. This difference was explained by the different nature of carbonates in the topsoil and subsoil horizons. Palygorskite is preferentially occluded within the soil carbonates of lacustrine origin over smectite and kaolinite. These carbonates are present mainly in the subsoil horizons. As a consequence, the presence of these carbonates in the subsoil horizons decreases the migration of mainly palygorskite.     

Strategies and priorities in field collections for ex situ conservation: the case of the Israel Plant Gene Bank

The ex situ collection of the Israel Plant Gene Bank (IGB) aims to encompass the rich local flora and its genetic diversity with an emphasis on crop wild relatives. However, to properly establish a core collection, collection efforts must be prioritized and strategized. We previously classified local plant genetic resources into four priority groups that assisted in strategizing the collection activities. The following years of intensive collection activity yielded over 4200 banked accessions. However, these do not necessarily represent the distribution range of the target species for collection (TSC) and consequently, their genetic diversity. To best cover the latter, the collecting area was divided into botanical districts and the magnitude of the collection was determined according to prioritization group, e.g., a wild relative of an agricultural crop with a vast distribution range should be represented by a larger number of banked accessions than one with a smaller range. Continuous evaluation of specific needs shapes the collection scheme of the IGB to maximize collection efforts, better represent the presumed genetic diversity of TSC, and establish its core collection.     

A dielectric omnidirectional reflector

A design criterion that permits truly omnidirectional reflectivity for all polarizations of incident light over a wide selectable range of frequencies was used in fabricating an all-dielectric omnidirectional reflector consisting of multilayer films. The reflector was simply constructed as a stack of nine alternating micrometer-thick layers of polystyrene and tellurium and demonstrates omnidirectional reflection over the wavelength range from 10 to 15 micrometers. Because the omnidirectionality criterion is general, it can be used to design omnidirectional reflectors in many frequency ranges of interest. Potential uses depend on the geometry of the system. For example, coating of an enclosure will result in an optical cavity. A hollow tube will produce a low-loss, broadband waveguide, whereas a planar film could be used as an efficient radiative heat barrier or collector in thermoelectric devices.     

Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800  g for 10 min and 2400  g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400  g for 3 min and freezing 2; M10 – centrifugation at 800  g for 10 min and freezing 2; R3 – centrifugation at 2400  g for 3 min and freezing 1; and R10 – centrifugation at 800  g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.