2,554 research outputs found
The CFI Microsoft Judgment and TRIPS Competition Flexibilities
The CFI Microsoft judgment is the first decision handed down by any court situated in a WTO Member state that regards the competition rules in the TRIPS Agreement in order to partly justify the application of domestic competition laws to the exercise of intellectual property rights (IPRs). The TRIPS Agreement allows WTO Members to enact and apply national competition laws to IPR-related anti-competitive practices. The position of the CFI finds support in this fact. Still, it is regrettable that the CFI did not invoke the TRIPS competition rules in justifying the Commission’s decision to force Microsoft to supply interoperability information. This article considers the consequences of the European position and the effects of TRIPS flexibilities for developing countries
Higher Order Contact on Cayley's Ruled Cubic Surface
It is well known that Cayley's ruled cubic surface carries a three-parameter
family of twisted cubics sharing a common point, with the same tangent and the
same osculating plane. We report on various results and open problems with
respect to contact of higher order and dual contact of higher order for these
curves
A proinflammatory role for Fas in joints of mice with collagen-induced arthritis
Collagen-induced arthritis (CIA) is a chronic inflammatory disease bearing all the hallmarks of rheumatoid arthritis, e.g. polyarthritis, synovitis, and subsequent cartilage/bone erosions. One feature of the disease contributing to joint damage is synovial hyperplasia. The factors responsible for the hyperplasia are unknown; however, an imbalance between rates of cell proliferation and cell death (apoptosis) has been suggested. To evaluate the role of a major pathway of cell death – Fas (CD95)/FasL – in the pathogenesis of CIA, DBA/1J mice with a mutation of the Fas gene (lpr) were generated. The susceptibility of the mutant DBA-lpr/lpr mice to arthritis induced by collagen type II was evaluated. Contrary to expectations, the DBA-lpr/lpr mice developed significantly milder disease than the control littermates. The incidence of disease was also significantly lower in the lpr/lpr mice than in the controls (40% versus 81%; P < 0.05). However DBA-lpr/lpr mice mounted a robust immune response to collagen, and the expression of local proinflammatory cytokines such as, e.g., tumor necrosis factor α (TNF-α) and IL-6 were increased at the onset of disease. Since the contribution of synovial fibroblasts to inflammation and joint destruction is crucial, the potential activating effect of Fas on mouse fibroblast cell line NIH3T3 was investigated. On treatment with anti-Fas in vitro, the cell death of NIH3T3 fibroblasts was reduced and the expression of proinflammatory cytokines TNF-α and IL-6 was increased. These findings suggest that impairment of immune tolerance by increased T-cell reactivity does not lead to enhanced susceptibility to CIA and point to a role of Fas in joint destruction
Metabolic and skeletal homeostasis are maintained in full locus GPRC6A knockout mice
Abstract The G protein-coupled receptor class C, group 6, subtype A (GPRC6A) is suggested to have a physiological function in glucose and bone metabolism, although the precise role lacks consensus due to varying findings in different knockout (KO) mouse models and inconsistent findings on the role of osteocalcin, a proposed GPRC6A agonist. We have further characterized a full locus GPRC6A KO model with respect to energy metabolism, including a long-term high-dose glucocorticoid metabolic challenge. Additionally, we analyzed the microarchitecture of tibiae from young, middle-aged and aged GPRC6A KO mice and wildtype (WT) littermates. Compared to WT, vehicle-treated KO mice presented with normal body composition, unaltered insulin sensitivity and basal serum insulin and glucose levels. Corticosterone (CS) treatment resulted in insulin resistance, abnormal fat accrual, loss of lean mass and suppression of serum osteocalcin levels in both genotypes. Interestingly, serum osteocalcin and skeletal osteocalcin mRNA levels were significantly lower in vehicle-treated GPRC6A KO mice compared to WT animals. However, WT and KO age groups did not differ in long bone mass and structure assessed by micro-computed tomography. We conclude that GPRC6A is not involved in glucose metabolism under normal physiological conditions, nor does it mediate glucocorticoid-induced dysmetabolism in mice. Moreover, GPRC6A does not appear to possess a direct, non-compensable role in long bone microarchitecture under standard conditions
Perforin deficiency attenuates collagen-induced arthritis
Collagen-induced arthritis (CIA), an approved animal model for rheumatoid arthritis, is thought to be a T cell-dependent disease. There is evidence that CD8(+ )T cells are a major subset controlling the pathogenesis of CIA. They probably contribute to certain features of disease, namely tissue destruction and synovial hyperplasia. In this study we examined the role of perforin (pfp), a key molecule of the cytotoxic death pathway that is expressed mainly in CD8(+ )T cells, for the pathogenesis of CIA. We generated DBA/1J mice suffering from mutations of the pfp molecule, DBA/1J-pfp(-/-), and studied their susceptibility to arthritis. As a result, pfp-deficient mice showed a reduced incidence (DBA/1J-pfp(+/+), 64%; DBA/1J-pfp(-/-), 54%), a slightly delayed onset (onset of disease: DBA/1J-pfp(+/+), 53 ± 3.6; DBA/1J-pfp(-/-), 59 ± 4.9 (mean ± SEM), and milder form of the disease (maximum disease score: DBA/1J-pfp(+/+), 7.3 ± 1.1; DBA/1J-pfp(-/-), 3.4 ± 1.4 (mean ± SEM); P < 0.05). Concomitantly, peripheral T cell proliferation in response to the specific antigen bovine collagen II was increased in pfp(-/- )mice compared with pfp(+/+ )mice, arguing for an impaired killing of autoreactive T cells caused by pfp deficiency. Thus, pfp-mediated cytotoxicity is involved in the initiation of tissue damage in arthritis, but pfp-independent cytotoxic death pathways might also contribute to CIA
Generating a Wnt switch: it’s all about the right dosage
Wnt proteins can activate different branches of the Wnt signaling pathway, raising the question of specificity. In this issue, Nalesso et al. (2011. J. Cell Biol. doi:10.1083/jcb.201011051) provide an answer to this conundrum by showing that different concentrations of Wnt ligands can elicit different intracellular responses. These findings not only provide new insights into the molecular mechanisms underlying Wnt signaling, but also indicate how Wnt gradients might contribute to tissue patterning during embryogenesis
A Prospective Study of Growth and Biomarkers of Exposure to Aflatoxin and Fumonisin during Early Childhood in Tanzania
Background: Aflatoxin and fumonisin are toxic food contaminants. Knowledge about effects of their exposure and coexposure on child growth is inadequate. Objective: We investigated the association between child growth and aflatoxin and fumonisin exposure in Tanzania. Methods: A total of 166 children were recruited at 6–14 months of age and studied at recruitment, and at the 6th and 12th month following recruitment. Blood and urine samples were collected and analyzed for plasma aflatoxin–albumin adducts (AF-alb) using ELISA, and urinary fumonisin B1 (UFB1) using liquid chromatography–mass spectrometry, respectively. Anthropometric measurements were taken, and growth index z-scores were computed. Results: AF-alb geometric mean concentrations (95% CIs) were 4.7 (3.9, 5.6), 12.9 (9.9, 16.7), and 23.5 (19.9, 27.7) pg/mg albumin at recruitment, 6 months, and 12 months from recruitment, respectively. At these respective sampling times, geometric mean UFB1 concentrations (95% CI) were 313.9 (257.4, 382.9), 167.3 (135.4, 206.7), and 569.5 (464.5, 698.2) pg/mL urine, and the prevalence of stunted children was 44%, 55%, and 56%, respectively. UFB1 concentrations at recruitment were negatively associated with length-for-age z-scores (LAZ) at 6 months (p = 0.016) and at 12 months from recruitment (p = 0.014). The mean UFB1 of the three sampling times (at recruitment and at 6 and 12 months from recruitment) in each child was negatively associated with LAZ (p < 0.001) and length velocity (p = 0.004) at 12 months from recruitment. The negative association between AF-alb and child growth did not reach statistical significance. Conclusions: Exposure to fumonisin alone or coexposure with aflatoxins may contribute to child growth impairment
Soliton approach to the noisy Burgers equation: Steepest descent method
The noisy Burgers equation in one spatial dimension is analyzed by means of
the Martin-Siggia-Rose technique in functional form. In a canonical formulation
the morphology and scaling behavior are accessed by mean of a principle of
least action in the asymptotic non-perturbative weak noise limit. The ensuing
coupled saddle point field equations for the local slope and noise fields,
replacing the noisy Burgers equation, are solved yielding nonlinear localized
soliton solutions and extended linear diffusive mode solutions, describing the
morphology of a growing interface. The canonical formalism and the principle of
least action also associate momentum, energy, and action with a
soliton-diffusive mode configuration and thus provides a selection criterion
for the noise-induced fluctuations. In a ``quantum mechanical'' representation
of the path integral the noise fluctuations, corresponding to different paths
in the path integral, are interpreted as ``quantum fluctuations'' and the
growth morphology represented by a Landau-type quasi-particle gas of ``quantum
solitons'' with gapless dispersion and ``quantum diffusive modes'' with a gap
in the spectrum. Finally, the scaling properties are dicussed from a heuristic
point of view in terms of a``quantum spectral representation'' for the slope
correlations. The dynamic eponent z=3/2 is given by the gapless soliton
dispersion law, whereas the roughness exponent zeta =1/2 follows from a
regularity property of the form factor in the spectral representation. A
heuristic expression for the scaling function is given by spectral
representation and has a form similar to the probability distribution for Levy
flights with index .Comment: 30 pages, Revtex file, 14 figures, to be submitted to Phys. Rev.
Compromised Mitochondrial Fatty Acid Synthesis in Transgenic Mice Results in Defective Protein Lipoylation and Energy Disequilibrium
A mouse model with compromised mitochondrial fatty acid synthesis has been engineered in order to assess the role of this pathway in mitochondrial function and overall health. Reduction in the expression of mitochondrial malonyl CoA-acyl carrier protein transacylase, a key enzyme in the pathway encoded by the nuclear Mcat gene, was achieved to varying extents in all examined tissues employing tamoxifen-inducible Cre-lox technology. Although affected mice consumed more food than control animals, they failed to gain weight, were less physically active, suffered from loss of white adipose tissue, reduced muscle strength, kyphosis, alopecia, hypothermia and shortened lifespan. The Mcat-deficient phenotype is attributed primarily to reduced synthesis, in several tissues, of the octanoyl precursors required for the posttranslational lipoylation of pyruvate and a-ketoglutarate dehydrogenase complexes, resulting in diminished capacity of the citric acid cycle and disruption of energy metabolism. The presence of an alternative lipoylation pathway that utilizes exogenous free lipoate appears restricted to liver and alone is insufficient for preservation of normal energy metabolism. Thus, de novo synthesis of precursors for the protein lipoylation pathway plays a vital role in maintenance of mitochondrial function and overall vigo
- …