Concerted Action of Androgens and Mechanical Strain Shifts Bone Metabolism from High Turnover into an Osteoanabolic Mode

Adhesion of bone cells to the extracellular matrix is a crucial requirement for osteoblastic development and function. Adhesion receptors connect the extracellular matrix with the cyto-skeleton and convey matrix deformation into the cell. We tested the hypothesis that sex hormones modulate mechanoperception of human osteoblastic cells (HOB) by affecting expression of adhesion molecules like fibronectin and the fibronectin receptor. Only dihydrotestosterone (DHT), but not 17β-estradiol, stimulated fibronectin (137%) and fibronectin receptor (252%) protein expression. The effects of deformation strain on HOB metabolism were investigated in a FlexerCell® strain unit. Cyclically applied strain (2.5% elongation) increased DNA synthesis (125%) and interleukin-6 (IL-6) production (170%) without significantly affecting alkaline phosphatase (AP) activity, type I collagen (PICP), or osteoprotegerin (OPG) secretion. 10 nM DHT pretreatment abolished the mitogenic response of HOB to strain and increased AP activity (119%), PICP (163%), and OPG production (204%). In conclusion, mechanical strain stimulates bone remodeling by increasing HOB mitosis and IL-6 production. DHT enhances the osteoanabolic impact of deformation strain by increasing bone formation via increased AP activity and PICP production. At the same time, bone resorption is inhibited by decreased IL-6 and increased OPG secretion into the bone microenvironment

Field validation of biocontrol strategies to control brown rot on stone fruit in several European countries

BACKGROUND: Brown rot caused by Monilinia spp. is the most signicant disease of stone fruit. New approaches to fruit production have necessitated the development of control strategies that are more eco- and consumer-friendly. An eficient field strategy to control brown rot was previously designed based on the application of two biocontrol agents (BCAs), Bacillus amyloliquefaciens CPA-8 (CPA-8) or Penicillium frequentans 909 (Pf909), with calendar-based treatment. In the present study, the strategy was validated on different stone fruit hosts in four producing countries over two seasons. RESULTS: The results obtained were reported according to three different scenarios: Scenario 1, in which there was no presence of disease in the field; Scenario 2, in which high disease pressure occurred in the field and treatments (biologicals or chemicals) were not effective; and Scenario 3, with low or medium to high disease presence. The results were successful because, in general, BCA strategies were shown to control brown rot to a similar extent as chemicals strategies. We found that most of the trials conducted in this study were classed under Scenario 3 (62.5%), with only 12.5% and 25% of the trials classed under Scenarios 1 and 2, respectively. CONCLUSION: These novel findings allowed the formulation of CPA-8 and Pf909 as valuable tools for farmers to produce stone fruits more competitively and meet consumer demand for safer and more environmentally friendly products.info:eu-repo/semantics/acceptedVersio

Stepwise screening of candidate antagonists for biological control of Blumeria graminis f. sp. tritici

Antagonists for the biological control of Blumeria graminis f. sp. tritici were selected using a stepwise screening approach. Fungal colonizers of powdery mildew pustules were isolated from leaves of cereals and other plant species. Spore production, cold tolerance, drought tolerance and UV-B resistance as important characteristics for application of biocontrol candidates in the phyllosphere were tested in in vitro assays and preliminary risk assessments were conducted. Amongst 850 tested isolates 58% belonged to various taxonomical groups of Cladosporium. Only 3% belonged to species that have been reported in literature as antagonistic to powdery mildews. The stepwise screening approach allowed to reduce the number of candidate antagonists using screening criteria that can be tested reliably and cost-effectively in in vitro assays and by data mining from initially 1237 isolates down to 143 candidate antagonists belonging to 42 taxonomical groups. The potential of these isolates to reduce conidia production of B. graminis f. sp. tritici. in wheat was assessed in bioassays on potted winter wheat plants under controlled conditions. A set of ten superior isolates was subsequently tested in a series of trials on potted spring wheat plants under open field conditions. Isolates Tilletiopsis pallescens BC0441 and T. pallescens BC0850 significantly reduced the number of powdery mildew pustules per flag leaf by 30 to 62%. Slopes of the regression lines fitted to data on number of powdery mildew pustules during time were significantly reduced by the antagonists indicating that the powdery mildew epidemics were slowed down. Treatments with T. pallescens BC0441 and T. pallescens BC0850 also reduced leaf coverage with powdery mildew pustules in a small-scale field trial in spring wheat.</p

Ytterbium valence phase transition in YbxIn1−xCu2\mathrm{Yb_{x}In_{1-x}Cu_2}

The recently reported sharp valence phase transition in cubic Yb$_0$$_.4$In$_0$$_.6$Cu$_2$ at Tv≃50 K has been studied by a variety of experimental techniques. X-ray diffraction studies from 4.2 to 300 K reveal the cubic Laves phase structure at all temperatures with a jump in the unit-cell size at the transition temperature T$_v$. Neutron diffraction proves the absence of magnetic order down to 10 K. Magnetic susceptibility data show that the transition temperature T$_v$ increases when Y$_b$ or In are substituted by La, Eu, and Sn and decreases when they are substituted by Y, Lu, and Ga. Mössbauer studies of $^1$$^7$$^0$Yb show that at 4.2 K the Yb ion is nonmagnetic in a cubic environment, whereas at 60 K it is magnetic. Mössbauer studies of 119Sn exhibit changes in both the spectral area and isomer shift at T$_v$. Electrical resistivity measurements exhibit a large increase in resistivity at T$_v$. Specific-heat measurements reveal a characteristic increase of c$_p$ around T$_v$. Comparison with Lu$_0$$_.4$In$_0$$_.6$Cu$_2$ behavior yields the increase in entropy due to the valence transition, 13.3(3) J/mole K, in very good agreement with a model calculation of a cubic-split Yb3+ and an interconfigurational excitation energy of 220 K. Finally, x-ray-absorption measurements at the Yb LIII edge reveal a sudden change in the 4f-electron occupancy at T$_v$ and temperature-independent valences, v(LIII)=2.9 and 2.8, above and below T$_v$, respectively

YTTERBIUM VALENCE PHASE-TRANSITION IN YBXIN1-XCU2

The recently reported sharp valence phase transition in cubic Yb$_0$$_.4$In$_0$$_.6$Cu$_2$ at Tv≃50 K has been studied by a variety of experimental techniques. X-ray diffraction studies from 4.2 to 300 K reveal the cubic Laves phase structure at all temperatures with a jump in the unit-cell size at the transition temperature T$_v$. Neutron diffraction proves the absence of magnetic order down to 10 K. Magnetic susceptibility data show that the transition temperature T$_v$ increases when Y$_b$ or In are substituted by La, Eu, and Sn and decreases when they are substituted by Y, Lu, and Ga. Mössbauer studies of $^1$$^7$$^0$Yb show that at 4.2 K the Yb ion is nonmagnetic in a cubic environment, whereas at 60 K it is magnetic. Mössbauer studies of 119Sn exhibit changes in both the spectral area and isomer shift at T$_v$. Electrical resistivity measurements exhibit a large increase in resistivity at T$_v$. Specific-heat measurements reveal a characteristic increase of c$_p$ around T$_v$. Comparison with Lu$_0$$_.4$In$_0$$_.6$Cu$_2$ behavior yields the increase in entropy due to the valence transition, 13.3(3) J/mole K, in very good agreement with a model calculation of a cubic-split Yb3+ and an interconfigurational excitation energy of 220 K. Finally, x-ray-absorption measurements at the Yb LIII edge reveal a sudden change in the 4f-electron occupancy at T$_v$ and temperature-independent valences, v(LIII)=2.9 and 2.8, above and below T$_v$, respectively