An agent-based simulation of the stolper–samuelson effect

We demonstrate that agent-based simulations can exhibit results in line with classic macroeconomic theory. In particular, we present an agent-based simulation of an Arrow–Debreu economy that accurately exhibits the Stolper–Samuelson effect as an emergent property. Absent of a Walrasian auctioneer or any other central coordination, we let firm and consumer agents of different types interact in an open, money-driven market. Exogenous preference shocks result in price and wage shifts that are in accordance with the general equilibrium solution, not only qualitatively but also quantitatively with high accuracy. Key to this achievement are three independent measures. First, we overcome the poor input synchronization of conventional price finding heuristics of firms in agent-based models by introducing sensor prices, a novel approach to price finding that decouples information exploitation from information exploration. Second, we improve accuracy and convergence by employing exponential search as exploration algorithm. Third, we normalize prices indirectly by fixing dividends, thereby stabilizing the system’s dynamics

Succession secondaire et perte de diversité végétale après réduction du broutage dans un pâturage boisé des Alpes centrales suisses

Freléchoux F., Meisser M. and Gillet F. 2007. Secondary succession and loss in plant diversity following a grazing decrease in a wooded pasture of the central Swiss Alps. Bot. Helv. 117: 37 - 56. Reduced cattle grazing pressure in the Alps has caused the reforestation of many subalpine pastures during the last decades. To understand the dynamics of natural reforestation and to evaluate how this change affects plant species diversity, we described the vegetation of a wooded pasture in the central Swiss Alps (Sembrancher, Valais) using the integrated synusial method. Based on stratified vegetation relevés in 27 plots,we defined 11 community types at the synusial level (two tree-layer, five shrub-layer, and four herb-layer synusiae), and four community types at the phytocoenosis level (pasture, tall forbs and scrub, wooded pasture and forest). The spatial distribution of these four phytocoenoses suggests that they represent successional stages after abandonment, and that the pathway of vegetation succession depends on the aspect. We suppose that on northern oriented, cool and shady locations, abandoned pastures first develop towards tall-forb meadows and scrub with Alnus viridis, and then to a preforested stage with Picea abies and Larix decidua. In contrast, on western oriented, warm and sunny location, Larix decidua (mainly) and Picea abies directly colonize the abandoned pastures, but further succession finally leads to the same pre-forested stage as on northern slopes. Plant species richness was highest in open areas and decreased by 25% as tree cover increased from 6% to 65%. According to our successional model, plant species diversity is lost more rapidly on northern slopes (with species-poor green alder scrub) than on western slopes (with species-rich young larch forests), suggesting that northern slopes most urgently need an appropriate grazing managemen

CA 125 in seminal plasma: correlation with semen parameters

Ovarian cancer marker CA 125 was measured in human seminal plasma, and the concentrations ranged between 22 and 1149 U/ml, and between 39 and 4711 U/ejaculate. This very high patient-to-patient variability was in contrast to a much lower within-patient variability, which was comparable to that of other semen parameters. No significant differences in CA 125 concentration were found in seminal plasma from normospermic patients, patients with male factors, vasectomized men, and in aliquots of samples which led to a pregnancy, via artificial insemination or in-vitro fertilization. The seminal plasma CA 125 concentration was not correlated with sperm count, motility and morphology. In contrast, seminal plasma CA 125 concentrations correlated with the age of the patient (P < 0.001) and inversely with the volume of the ejaculate (P < 0.001). These correlations were independent of each other. CA 125 did not correlate with the prostatic marker zinc, but did do so with the seminal vesicle marker fructose and the epididymal marker carnitin

Involvement of MAPK pathway in TNF-α-induced MMP-9 expression in human trophoblastic cells

The aim of this article was to investigate the signalling pathways involved in metalloproteinase-9 (MMP-9) expression induced by tumour necrosis factor-α (TNF-α) in first-trimester trophoblastic cells. TNF-α-induced MMP-9 expression, secretion and activity were completely blocked by stress-activated protein kinase/jun kinase (SAPK/JNK) and Erk inhibitors (SP600 125 and U0126 respectively) but not by p38 mitogen-activated protein kinase (MAPK) inhibitors (SB203 580 and SB202 190). Stimulation of HIPEC 65 cells with TNF-α caused phosphorylation of JNK and extracellular signal-regulated kinase 1/2 (Erk1/2), with a peak after 20 min of treatment. Transcription factors nuclear factor-κB (NF-κB) and activator protein 1 (AP-1)-binding site were identified as the cis-elements involved in TNF-α activation as determined by electromobility shift assays. TNF-α-induced transactivation of NF-κB was inhibited by U0126, whereas TNF-α-induced transactivation of AP-1 was inhibited by SP600 125. Taken together, these results indicate that in trophoblastic cells, TNF-α probably activates two different pathways leading to MMP-9 expression: (a) Erk1/2 pathway which in turn initiates NF-κB activation and (b) SAPK/JNK pathway that activates AP-

Effects of tumour necrosis factor-α, interleukin-1 α, macrophage colony stimulating factor and transforming growth factor β on trophoblastic matrix metalloproteinases

The aim of this study was to determine the effects of tumour necrosis factor α (TNF), interleukin-1 α (IL-1α), macrophage colony-stimulating factor (MCSF) and transforming growth factor β (TGFβ) on the secretion of matrix metalloproteinases (MMP), human chorionic gonadotrophin (HCG) and fetal fibronectin (fFN) by purified first trimester cytotrophoblastic cells (CTB) in vitro. CTB were obtained from legal abortions and cultured in vitro in the presence or absence of the different cytokines. Secreted gelatinases were analysed in the culture supernatants by zymography, by measurements of the total gelatinolytic activity and by enzyme immunoassays. HCG and fFN were measured by commercially available immunoassays. TNF increased the total gelatinolytic activity by increasing MMP-9 activity (P = 0.025-0.0177) but decreased MMP-2 activity (P < 0.03) and immunoreactivity (P < 0.05), fFN (P < 0.02) and HCG (P < 0.01). IL-1α significantly increased the secretion of fFN (P < 0.02), the activity (P < 0.02) and immunoreactivity (P < 0.05) of MMP-9 but had no effect on the other parameters. MCSF increased MMP-9 immunoreactivity (P < 0.05) and moderately decreased HCG. TGFβ inhibited total gelatinolytic activity, MMP-9 activity and immunoreactivity, but was without effect on MMP-2 concentrations and activity. TGFβ decreased HCG (P < 0.041) and increased fFN (P < 0.042). Our results indicate that TGFβ, TNF and IL-1α are important regulators of trophoblastic MMP secretio

Immunology: Investigations on the cell type responsible for the endometrial secretion of complement component 3 (C3)

It has been shown that and human endometria have the capacity to produce complement component 3 (C3). In rats, endometrial C3 is an oestrogen-dependent protein produced and secreted by glandular cells. The cell responsible for the synthesis and secretion of human endometrial C3 has not been clearly defined. Our study was aimed at answering this question. Samples of endometrium obtained from hysterectomies were either immunostained for C3 or digested with collagenase; then the stromal and glandular cells were separated and immunopurified (or not) with an antibody to CD45 coupled to magnetic beads to eliminate the endometrial lymphomyeloid cells. Cells were cultured for 2 weeks and C3 measured in the medium by an in-house radioimmunoassay. Glandular as well as stromal cells stained positively for C3 and released C3 in vitro. The release of C3 from both cell types could be inhibited by cycloheximide. Epithelial cells produced significantly more C3 than stromal cells, and endometrial C3 production was higher for both cell types when these were obtained from secretory as compared to proliferative endometria. Lymphomyeloid cells were possibly a source of C3 since after immunoadsorption of these cells, the remaining stromal or glandular cells produced significantly less C3. We conclude that endometrial stromal, glandular and lymphomyeloid cells all produce C

Giftgrubeite, CaMn2Ca2(AsO4)2(AsO3OH)2·4H2O, a new member of the hureaulite group from Sainte-Marie-aux-Mines, Haut-Rhin Department, Vosges, France

Giftgrubeite, ideally CaMn2Ca2(AsO4)2(AsO3OH)2·4H2O, is a new mineral occurring at the Giftgrube Mine, St Jacques vein, Rauenthal, Sainte-Marie-aux-Mines, Haut-Rhin Department, Grand Est, France and named after the type-locality. Giftgrubeite is mostly associated with Mn-bearing calcite, native arsenic, löllingite, and picropharmacolite. It is a recent secondary mineral, formed by alteration of the arsenical vein minerals after mining. Giftgrubeite occurs in colorless, rarely pearl white to pale yellow rosettes of brittle tabular crystals flattened on {1 0 0} and up to 0.2 mm in size. Hardness (Mohs) is 3 ½, Dmeas is 3.23(2) g·cm-3, Dcalc is 3.24 g·cm-3. The new mineral is biaxial negative without pleochroism. Measured 2V angle is ~72° and calculated 2V angle is 75.1°; the refractive indices measured in white light are: α = 1.630(2), β= 1.640(2) and γ = 1.646(2). The most prominent Raman bands are at 902, 885, 864, 851, 824, 797 and 759 cm-1. The empirical chemical formula is (Ca3.04Mn1.30Mg0.38Fe0.28)Σ5.00(AsO4)1.99(AsO3OH)2·4H2O. Giftgrubeite is monoclinic, C2/c, Z = 4, with a = 18.495(7) Å, b = 9.475(4) Å, c = 9.986(4) Å, β = 96.79(3)° and V = 1737.7(12) Å3. The six strongest lines in the X-ray powder diffraction pattern are [d in Å (I)(hkl)]: 3.33 (100)(-2 2 2), 3.18 (80)(2 2 2), 2.414 (60)(7 1 1), 4.80 (50)(-3 1 1), 4.65 (50)(-2 0 2) and 3.05 (50)(1 1 3). The structure of giftgrubeite was solved from the crystal retrieved from the type specimen by the charge-flipping algorithm. Giftgrubeite contains a well-known structure type parent to the hureaulite group of minerals, which is based upon an octahedral edge-sharing pentamers of M2+-polyhedra; pentamers linked into a loose framework by sharing corners with octahedra in adjacent pentamers and further by AsO4 and AsO3OH tetrahedra. There are three distinct octahedral sites: M1, M2, and M3. In the case of giftgrubeite, two of the M sites were found to be fully occupied by Ca; namely M1 and M3. The M2 site was then found to contain Mg besides dominant Mn. Considering the refined site occupancies, the structural formula for giftgrubeite is Ca3Mn1.30Mg0.70(AsO4)2(AsO3OH)2(H2O)4. Giftgrubeite is an ordered intermediate member between villyaellenite, MnMn2Ca2(AsO3OH)2(AsO4)2·4H2O and sainfeldite, CaCa2Ca2(AsO4)2(AsO3OH)2·4H2O