1,014 research outputs found
The Internet Activities of FiBL
The poster presents the main internet sites maintained by FIBL in 2002:
www.fibl.org
www.oekolandbau.de
http://www.organicxseeds.com
Unlocking the "Black box": internal female genitalia in Sepsidae (Diptera) evolve fast and are species-specific
Background: The species-specificity of male genitalia has been well documented in many insect groups and sexual selection has been proposed as the evolutionary force driving the often rapid, morphological divergence. The internal female genitalia, in sharp contrast, remain poorly studied. Here, we present the first comparative study of the internal reproductive system of Sepsidae. We test the species-specificity of the female genitalia by comparing recently diverged sister taxa. We also compare the rate of change in female morphological characters with the rate of fast-evolving, molecular and behavioral characters. Results: We describe the ectodermal parts of the female reproductive tract for 41 species representing 21 of the 37 described genera and define 19 morphological characters with discontinuous variation found in eight structures that are part of the reproductive tract. Using a well-resolved molecular phylogeny based on 10 genes, we reconstruct the evolution of these characters across the family 120 steps; Consistency Index (CI): 0.41]. Two structures, in particular, evolve faster than the rest. The first is the ventral receptacle, which is a secondary sperm storage organ. It accounts for more than half of all the evolutionary changes observed (7 characters; 61 steps; CI: 0.46). It is morphologically diverse across genera, can be bi-lobed or multi-chambered (up to 80 chambers), and is strongly sclerotized in one clade. The second structure is the dorsal sclerite, which is present in all sepsids except Orygma luctuosum and Ortalischema albitarse. It is associated with the opening of the spermathecal ducts and is often distinct even among sister species (4 characters; 16 steps; CI: 0.56). Conclusions: We find the internal female genitalia are diverse in Sepsidae and diagnostic for all species. In particular, fast-evolving structures like the ventral receptacle and dorsal sclerite are likely involved in post-copulatory sexual selection. In comparison to behavioral and molecular data, the female structures are evolving 2/3 as fast as the non-constant third positions of the COI barcoding gene. They display less convergent evolution in characters (CI = 0.54) than the third positions or sepsid mating behavior (CICOI = 0.36; CIBEHAV = 0.45)
Distance dependence of the phase signal in eddy current microscopy
Atomic force microscopy using a magnetic tip is a promising tool for
investigating conductivity on the nano-scale. By the oscillating magnetic tip
eddy currents are induced in the conducting parts of the sample which can be
detected in the phase signal of the cantilever. However, the origin of the
phase signal is still controversial because theoretical calculations using a
monopole appoximation for taking the electromagnetic forces acting on the tip
into account yield an effect which is too small by more than two orders of
magnitude. In order to determine the origin of the signal we used especially
prepared gold nano patterns embedded in a non-conducting polycarbonate matrix
and measured the distance dependence of the phase signal. Our data clearly
shows that the interacting forces are long ranged and therefore, are likely due
to the electromagnetic interaction between the magnetic tip and the conducting
parts of the surface. Due to the long range character of the interaction a
change in conductivity of m can be
detected far away from the surface without any interference from the
topography
The Influence of IL-10 and TNFα on Chondrogenesis of Human Mesenchymal Stromal Cells in Three-Dimensional Cultures
Chondrogenic differentiated mesenchymal stromal cells (MSCs) are a promising
cell source for articular cartilage repair. This study was undertaken to
determine the effectiveness of two three-dimensional (3D) culture systems for
chondrogenic MSC differentiation in comparison to primary chondrocytes and to
assess the effect of Interleukin (IL)-10 and Tumor Necrosis Factor (TNF)α on
chondrogenesis by MSCs in 3D high-density (H-D) culture. MSCs were isolated
from femur spongiosa, characterized using a set of typical markers and
introduced in scaffold-free H-D cultures or non-woven polyglycolic acid (PGA)
scaffolds for chondrogenic differentiation. H-D cultures were stimulated with
recombinant IL-10, TNFα, TNFα + IL-10 or remained untreated. Gene and protein
expression of type II collagen, aggrecan, sox9 and TNFα were examined. MSCs
expressed typical cell surface markers and revealed multipotency. Chondrogenic
differentiated cells expressed cartilage-specific markers in both culture
systems but to a lower extent when compared with articular chondrocytes.
Chondrogenesis was more pronounced in PGA compared with H-D culture. IL-10
and/or TNFα did not impair the chondrogenic differentiation of MSCs. Moreover,
in most of the investigated samples, despite not reaching significance level,
IL-10 had a stimulatory effect on the type II collagen, aggrecan and TNFα
expression when compared with the respective controls
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Sodium hydroxide enhances extractability and analysis of proanthocyanidins in ensiled sainfoin (onobrychis viciifolia)
Little information exists on the effects of ensiling on condensed tannins or proanthocyanidins. The acetone–butanol–HCl assay is suitable for measuring proanthocyanidin contents in a wide range of samples, silages included, but provides limited information on proanthocyanidin composition, which is of interest for deciphering the relationships between tannins and their bioactivities in terms of animal nutrition or health. Degradation with benzyl mercaptan (thiolysis) provides information on proanthocyanidin composition, but proanthocyanidins in several sainfoin silages have proved resistant to thiolysis. We now report that a pretreatment step with sodium hydroxide prior to thiolysis was needed to enable their analysis. This alkaline treatment increased their extractability from ensiled sainfoin and facilitated especially the release of larger proanthocyanidins. Ensiling reduced assayable proanthocyanidins by 29%, but the composition of the remaining proanthocyanidins in silage resembled that of the fresh plants
Contact-controlled amoeboid motility induces dynamic cell trapping in 3D-microstructured surfaces.
On flat substrates, several cell types exhibit amoeboid migration, which is characterized by restless stochastic successions of pseudopod protrusions. The orientation and frequency of new membrane protrusions characterize efficient search modes, which can respond to external chemical stimuli as observed during chemotaxis in amoebae. To quantify the influence of mechanical stimuli induced by surface topography on the migration modes of the amoeboid model organism Dictyostelium discoideum, we apply high resolution motion analysis in microfabricated pillar arrays of defined density and geometry. Cell motion is analyzed by a two-state motility-model, distinguishing directed cellular runs from phases of isotropic migration that are characterized by randomly oriented cellular protrusions. Cells lacking myosin II or cells deprived of microtubules show significantly different behavior concerning migration velocities and migrational angle distribution, without pronounced attraction to pillars. We conclude that microtubules enhance cellular ability to react with external 3D structures. Our experiments on wild-type cells show that the switching from randomly formed pseudopods to a stabilized leading pseudopod is triggered by contact with surface structures. These alternating processes guide cells according to the available surface in their 3D environment, which we observed dynamically and in steady-state situations. As a consequence, cells perform "home-runs" in low-density pillar arrays, crawling from pillar to pillar, with a characteristic dwell time of 75 s. At the boundary between a flat surface and a 3D structured substrate, cells preferentially localize in contact with micropillars, due to the additionally available surface in the microstructured arrays. Such responses of cell motility to microstructures might open new possibilities for cell sorting in surface structured arrays
Организация и тактика тушения пожара и проведение аварийно-спасательных работ при ликвидации чрезвычайной ситуации на закладочном комплексе Таштагольского филиала ОАО "Евразруда"
Предметом исследования является организации аварийно-спасательных работ на горнодобывающих предприятиях подразделениями ФПС РФ на закладочном комплексе Таштагольского филиала ОАО "Евразруда". Цель работы – разработать план тушения пожара на горнодобывающем предприятии с расчетом сил и средств, участвующих в проведении аварийно-спасательных работ.The subject of research is the organization of rescue operations at the mining enterprises of the Russian Federation Federal Border Service units in the complex stowing Tashtagolsky branch of OJSC "Evrazruda". Purpose - to develop a plan to extinguish a fire on the mining company to the calculation of forces and means involved in carrying out rescue operations
Changes in Feed Proanthocyanidin Profiles during Silage Production and Digestion by Lamb
Proanthocyanidins are plant specialized metabolites which are beneficial
to animal nutrition and health. This study determined how
proanthocyanidin profiles of sainfoin (Onobrychis viciifolia) and birdsfoot trefoil (Lotus corniculatus)
change during the forage conservation process and along the digestive
tract of lamb. We determined soluble, protein- and fiber-bound
proanthocyanidins by spectrophotometric methods and soluble
proanthocyanidin profiles by UPLC-MS/MS. During the conservation
process, the total proanthocyanidin contents reduced in both forages and
the relative proportion of insoluble proanthocyanidins increased,
especially in sainfoin. The soluble proanthocyanidins, their mean degree
of polymerization and the relative prodelphinidin share declined in
both feed species. In the abomasum of lambs fed sainfoin silage, most of
the proanthocyanidins were in insoluble form bound to proteins and
fibers, but in the small and large intestines, the proportion of soluble
proanthocyanidins increased again. For lambs fed birdsfoot trefoil, the
trend was not so clear as proanthocyanidins were already mainly soluble
in the abomasum. Nevertheless, a large part of soluble
proanthocyanidins was recovered in the digestive tract but could not be
detected by the UPLC-MS/MS method used. This study suggests that
proanthocyanidins have probably been metabolized in the digestive tract
by the resident microbiota.</p
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