An eclectic third generation model of financial and exchange rate crises

[cat] En aquest treball es presenta un model eclèctic que sistematitza la dinàmica de les crisis que s’autoconfimen, usant els principals aspectes de les tres tipologies dels models de crisis canviàries de tercera generació, amb la finalitat de descriure els fets que precipiten la renúncia al manteniment d’una paritat fixada. Les contribucions més notables són les implicacions per a la política econòmica, així com la pèrdua del paper del tipus de canvi com instrument d’ajust macroeconòmic, quan els efectes de balanç són una possibilitat real.

First-generation linkage map for the European tree frog (Hyla arborea) with utility in congeneric species.

BACKGROUND: Western Palearctic tree frogs (Hyla arborea group) represent a strong potential for evolutionary and conservation genetic research, so far underexploited due to limited molecular resources. New microsatellite markers have recently been developed for Hyla arborea, with high cross-species utility across the entire circum-Mediterranean radiation. Here we conduct sibship analyses to map available markers for use in future population genetic applications. FINDINGS: We characterized eight linkage groups, including one sex-linked, all showing drastically reduced recombination in males compared to females, as previously documented in this species. Mapping of the new 15 markers to the ~200 My diverged Xenopus tropicalis genome suggests a generally conserved synteny with only one confirmed major chromosome rearrangement. CONCLUSIONS: The new microsatellites are representative of several chromosomes of H. arborea that are likely to be conserved across closely-related species. Our linkage map provides an important resource for genetic research in European Hylids, notably for studies of speciation, genome evolution and conservation.

Generation and validation of a normative, age-specific reference curve for lumbar spine trabecular bone score (TBS) in French women.

Age-related changes in lumbar vertebral microarchitecture are evaluated, as assessed by trabecular bone score (TBS), in a cohort of 5,942 French women. The magnitude of TBS decline between 45 and 85 years of age is piecewise linear in the spine and averaged 14.5 %. TBS decline rate increases after 65 years by 50 %. INTRODUCTION: This study aimed to evaluate age-related changes in lumbar vertebral microarchitecture, as assessed by TBS, in a cohort of French women aged 45-85 years. METHODS: An all-comers cohort of French Caucasian women was selected from two clinical centers. Data obtained from these centers were cross-calibrated for TBS and bone mineral density (BMD). BMD and TBS were evaluated at L1-L4 and for all lumbar vertebrae combined using GE-Lunar Prodigy densitometer images. Weight, height, and body mass index (BMI) also were determined. To validate our all-comers cohort, the BMD normative data of our cohort and French Prodigy data were compared. RESULTS: A cohort of 5,942 French women aged 45 to 85 years was created. Dual-energy X-ray absorptiometry normative data obtained for BMD from this cohort were not significantly different from French prodigy normative data (p = 0.15). TBS values at L1-L4 were poorly correlated with BMI (r = -0.17) and weight (r = -0.14) and not correlated with height. TBS values obtained for all lumbar vertebra combined (L1, L2, L3, L4) decreased with age. The magnitude of TBS decline at L1-L4 between 45 and 85 years of age was piecewise linear in the spine and averaged 14.5 %, but this rate increased after 65 years by 50 %. Similar results were obtained for other region of interest in the lumbar spine. As opposed to BMD, TBS was not affected by spinal osteoarthrosis. CONCLUSION: The age-specific reference curve for TBS generated here could therefore be used to help clinicians to improve osteoporosis patient management and to monitor microarchitectural changes related to treatment or other diseases in routine clinical practice.

Modulation of proteasomal activity required for the generation of a cytotoxic T lymphocyte-defined peptide derived from the tumor antigen MAGE-3.

We have analyzed the presentation of human histocompatability leukocyte antigen-A*0201-associated tumor peptide antigen MAGE-3271-279 by melanoma cells. We show that specific cytotoxic T lymphocyte (CTL)-recognizing cells transfected with a minigene encoding the preprocessed fragment MAGE-3271-279 failed to recognize cells expressing the full length MAGE-3 protein. Digestion of synthetic peptides extended at the NH2 or COOH terminus of MAGE-3271-279 with purified human proteasome revealed that the generation of the COOH terminus of the antigenic peptide was impaired. Surprisingly, addition of lactacystin to purified proteasome, though partially inhibitory, resulted in the generation of the antigenic peptide. Furthermore, treatment of melanoma cells expressing the MAGE-3 protein with lactacystin resulted in efficient lysis by MAGE-3271-279-specific CTL. We therefore postulate that the generation of antigenic peptides by the proteasome in cells can be modulated by the selective inhibition of certain of its enzymaticactivities.

Involvement of autophagy in hypoxic-excitotoxic neuronal death.

Neuronal autophagy is increased in numerous excitotoxic conditions including neonatal cerebral hypoxia-ischemia (HI). However, the role of this HI-induced autophagy remains unclear. To clarify this role we established an in vitro model of excitotoxicity combining kainate treatment (Ka, 30 µM) with hypoxia (Hx, 6% oxygen) in primary neuron cultures. KaHx rapidly induced excitotoxic death that was completely prevented by MK801 or EGTA. KaHx also stimulated neuronal autophagic flux as shown by a rise in autophagosome number (increased levels of LC3-II and punctate LC3 labeling) accompanied by increases in lysosomal abundance and activity (increased SQSTM1/p62 degradation, and increased LC3-II levels in the presence of lysosomal inhibitors) and fusion (shown using an RFP-GFP-LC3 reporter). To determine the role of the enhanced autophagy we applied either pharmacological autophagy inhibitors (3-methyladenine or pepstatinA/E64) or lentiviral vectors delivering shRNAs targeting Becn1 or Atg7. Both strategies reduced KaHx-induced neuronal death. A prodeath role of autophagy was also confirmed by the enhanced toxicity of KaHx in cultures overexpressing BECN1 or ATG7. Finally, in vivo inhibition of autophagy by intrastriatal injection of a lentiviral vector expressing a Becn1-targeting shRNA increased the volume of intact striatum in a rat model of severe neonatal cerebral HI. These results clearly show a death-mediating role of autophagy in hypoxic-excitotoxic conditions and suggest that inhibition of autophagy should be considered as a neuroprotective strategy in HI brain injuries.

Senior Drivers' Workbook, April 21, 2009

This booklet is part of the Iowa Department of Transportation’s “Choices Not Chances - The Road to Driving Safer and Longer” series. These booklets and video were developed to help Iowa drivers remain safe and mobile as they age. For more information, contact the Department of Transportation’s Office of Driver Services.

Stochastic generation of homogeneous isotropic turbulence with well-defined-spectra

A precise and simple computational model to generate well-behaved two-dimensional turbulent flows is presented. The whole approach rests on the use of stochastic differential equations and is general enough to reproduce a variety of energy spectra and spatiotemporal correlation functions. Analytical expressions for both the continuous and the discrete versions, together with simulation algorithms, are derived. Results for two relevant spectra, covering distinct ranges of wave numbers, are given.

Generation and characterization of a Notch1 signaling-specific reporter mouse line.

Signaling through the Notch1 receptor is essential for the control of numerous developmental processes during embryonic life as well as in adult tissue homeostasis and disease. Since the outcome of Notch1 signaling is highly context-dependent, and its precise physiological and pathological role in many organs is unclear, it is of great interest to localize and identify the cells that receive active Notch1 signals in vivo. Here, we report the generation and characterization of a BAC-transgenic mouse line, N1-Gal4VP16, that when crossed to a Gal4-responsive reporter mouse line allowed the identification of cells undergoing active Notch1 signaling in vivo. Analysis of embryonic and adult N1-Gal4VP16 mice demonstrated that the activation pattern of the transgene coincides with previously observed activation patterns of the endogenous Notch1 receptor. Thus, this novel reporter mouse line provides a unique tool to specifically investigate the spatial and temporal aspects of Notch1 signaling in vivo. genesis 50:700-710, 2012. © 2012 Wiley Periodicals, Inc.

The nNOS-p38MAPK Pathway Is Mediated by NOS1AP during Neuronal Death.

Neuronal nitric oxide synthase (nNOS) and p38MAPK are strongly implicated in excitotoxicity, a mechanism common to many neurodegenerative conditions, but the intermediary mechanism is unclear. NOS1AP is encoded by a gene recently associated with sudden cardiac death, diabetes-associated complications, and schizophrenia (Arking et al., 2006; Becker et al., 2008; Brzustowicz, 2008; Lehtinen et al., 2008). Here we find it interacts with p38MAPK-activating kinase MKK3. Excitotoxic stimulus induces recruitment of NOS1AP to nNOS in rat cortical neuron culture. Excitotoxic activation of p38MAPK and subsequent neuronal death are reduced by competing with the nNOS:NOS1AP interaction and by knockdown with NOS1AP-targeting siRNAs. We designed a cell-permeable peptide that competes for the unique PDZ domain of nNOS that interacts with NOS1AP. This peptide inhibits NMDA-induced recruitment of NOS1AP to nNOS and in vivo in rat, doubles surviving tissue in a severe model of neonatal hypoxia-ischemia, a major cause of neonatal death and pediatric disability. The highly unusual sequence specificity of the nNOS:NOS1AP interaction and involvement in excitotoxic signaling may provide future opportunities for generation of neuroprotectants with high specificity.

Generation of spatiotemporal colored noise

We develop an algorithm to simulate a Gaussian stochastic process that is non-¿-correlated in both space and time coordinates. The colored noise obeys a linear reaction-diffusion Langevin equation with Gaussian white noise. This equation is exactly simulated in a discrete Fourier space.

Involvement of gap junctional intercellular communication in the pathophysiology of inflammation

SUMMARY Inflammation has evolved as a mechanism to defend the body against invading microorganisms and to respond to injury. It requires the coordinated response of a large number of cell types from the whole organism in a time- and space-dependent fashion. This coordination involves several cell-cell communication mechanisms. Exchange of humoral mediators such as cytokines is a major one. Moreover, direct contact between cells happens and plays a primordial role, for example when macrophages present antigens to lymphocytes. Contact between endothelial cells and leucocytes occurs when the latter cross the blood vessel barrier and transmigrate to the inflammatory site. A particular way by which cells communicate with each other in the course of inflammation, which at this time starts to gain attention, is the intercellular communication mediated by gap junctions. Gap junctions are channels providing a direct pathway (i.e. without transit through the extracellular space) for the diffusion of small molecules between adjacent cells. This process is known as gap junctional intercellular communication (GJIC). The general aim of this thesis was to study a possible involvement of GJIC in the pathophysiology of inflammation. A first part of the work was dedicated to study the implication of GJIC in the modification of vascular endothelial function by inflammation. In a second part, we were interested in the possible role of GJIC in the transmigration of neutrophil polymorphonuclear leucocytes through the endothelium. The main positive finding of this work is that acute inflammation preferentially modulates the expression of connexin 40 (Cx40), a gap junction protein specifically expressed in vascular endothelium. The modulation could be towards overexpression (aortic endothelium of septic rats) or towards downregulation (acutely inflamed mouse lung). We put a lot of efforts in search of possible functions of these modulations, in two directions: a potential protective role of Cx40 increased expression against sepsis-induced endothelial dysfunction, and a facilitating role of Cx40 decreased expression in neutrophil transmigration. To pursue both directions, it seemed logical to study the impact of Cx40 deletion using knock-out mice. Concerning the potential protective role of Cx40 overexpression we encountered a roadblock as we observed, in the aorta, a Cx40 downregulation in wild type mouse whereas Cx40 was upregulated in the rat. Regarding the second direction and using an in vivo approach, we observed that pulmonary neutrophil transmigration was not affected by the genetic deletion of Cx40. In spite of their negative nature, these results are the very first ones regarding the potential implication of GJIC concerning leucocyte transmigration in vivo. Because this process involves such tight cell-cell physical contacts, the hypothesis for a role of GJIC remains attractive.