Vulnerability assessment of distributed systems

In this project I have carried out a vulnerability assessment of a component of the Condor Middleware. In this assessment I have sought and found the more dangerous software vulnerabilities of this system, I have reported them to the development team such that they may be fixed, and thus improve the security of this distributed system, and the networks that use it.

Controladores PI con acción de reset

El control automàtic exerceix un paper important en molts processos de la industria. Cada un dels sistemes de control requereix d’un controlador, la majoria dels quals són del tipus PI. L’objectiu d’aquest projecte es investigar tècniques que permetin superar les limitacions que tenen els controladors PI lineals. En la resposta d’un sistema de control es poden distingir dues tasques diferents: El seguiment a un canvi d’entrada o consigna correspon a la tasca de servo, mentre que el rebuig a pertorbacions correspon a la tasca de regulatori. Al típic esquema de control realimentat, aquestes dues tasques estan enfrontades, és a dir, una millora a la tasca de servo implica un empitjorament a la tasca de regulatori i a l’inversa. Això suposa un problema al rendiment del sistema, així com la necessitat d’establir un cert compromís entre les dues tasques. El que es pretén en aquest projecte es implementar senzilles regles de control no lineal amb la finalitat de millorar el rendiment del sistema i evitar la necessitat d’establir un compromís entre les dues tasques. Així, es pretén superar les limitacions que aquest té, obtenint controladors PI alternatius fàcilment sintetitzables.

Estudi descriptiu de l'ús de xarxes socials online per la promoció de l'alimentació saludable en hospitals dels Estats Units

Internet i les xarxes socials online s'estan mostrant com a útils en la promoció de la salut i en la difusió d'hàbits saludables. L'objectiu del treball és observar el grau d'utilització que es fa de les xarxes socials online per a la promoció d'hàbits d'alimentació saludable. S'ha dissenyat un estudi observacional descriptiu transversal amb una mostra de 14 hospitals dels Estats Units. A l'estudi s'ha trobat una bona freqüència d'utilització dels canals que ofereix la xarxa però una baixa freqüència per fer promoció d'hàbits saludables en alimentació.

A hybrid method for sag source location in power network

The work presented in this paper belongs to the power quality knowledge area and deals with the voltage sags in power transmission and distribution systems. Propagating throughout the power network, voltage sags can cause plenty of problems for domestic and industrial loads that can financially cost a lot. To impose penalties to responsible party and to improve monitoring and mitigation strategies, sags must be located in the power network. With such a worthwhile objective, this paper comes up with a new method for associating a sag waveform with its origin in transmission and distribution networks. It solves this problem through developing hybrid methods which hire multiway principal component analysis (MPCA) as a dimension reduction tool. MPCA reexpresses sag waveforms in a new subspace just in a few scores. We train some well-known classifiers with these scores and exploit them for classification of future sags. The capabilities of the proposed method for dimension reduction and classification are examined using the real data gathered from three substations in Catalonia, Spain. The obtained classification rates certify the goodness and powerfulness of the developed hybrid methods as brand-new tools for sag classification

The Determinants of Urban (Un)employment Duration: Evidence from Barcelona

This paper analyses the likelihood of leaving and joining employment in an urban area. Estimates show that individual, firm, regulatory and macroeconomic factors a ffect urban (un)employment duration in di fferent degrees. Also, national and urban (un)employment seem to share a common baseline hazard and similar macroeconomic and regulatory drivers. Individual characteristics are the only source of di fference we can identify between national and urban (un)employment duration. Keywords: Duration Models, Urban (Un)employment. JEL Classi fication: J64, R23.

Alum interaction with dendritic cell membrane lipids is essential for its adjuvanticity.

As an approved vaccine adjuvant for use in humans, alum has vast health implications, but, as it is a crystal, questions remain regarding its mechanism. Furthermore, little is known about the target cells, receptors, and signaling pathways engaged by alum. Here we report that, independent of inflammasome and membrane proteins, alum binds dendritic cell (DC) plasma membrane lipids with substantial force. Subsequent lipid sorting activates an abortive phagocytic response that leads to antigen uptake. Such activated DCs, without further association with alum, show high affinity and stable binding with CD4(+) T cells via the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1). We propose that alum triggers DC responses by altering membrane lipid structures. This study therefore suggests an unexpected mechanism for how this crystalline structure interacts with the immune system and how the DC plasma membrane may behave as a general sensor for solid structures.

Glucagon-like peptide-1 protects beta-cells against apoptosis by increasing the activity of an IGF-2/IGF-1 receptor autocrine loop.

OBJECTIVE: The gluco-incretin hormones glucagon-like peptide (GLP)-1 and gastric inhibitory peptide (GIP) protect beta-cells against cytokine-induced apoptosis. Their action is initiated by binding to specific receptors that activate the cAMP signaling pathway, but the downstream events are not fully elucidated. Here we searched for mechanisms that may underlie this protective effect. RESEARCH DESIGN AND METHODS: We performed comparative transcriptomic analysis of islets from control and GipR(-/-);Glp-1-R(-/-) mice, which have increased sensitivity to cytokine-induced apoptosis. We found that IGF-1 receptor expression was markedly reduced in the mutant islets. Because the IGF-1 receptor signaling pathway is known for its antiapoptotic effect, we explored the relationship between gluco-incretin action, IGF-1 receptor expression and signaling, and apoptosis. RESULTS: We found that GLP-1 robustly stimulated IGF-1 receptor expression and Akt phosphorylation and that increased Akt phosphorylation was dependent on IGF-1 but not insulin receptor expression. We demonstrated that GLP-1-induced Akt phosphorylation required active secretion, indicating the presence of an autocrine activation mechanism; we showed that activation of IGF-1 receptor signaling was dependent on the secretion of IGF-2. We demonstrated, both in MIN6 cell line and primary beta-cells, that reducing IGF-1 receptor or IGF-2 expression or neutralizing secreted IGF-2 suppressed GLP-1-induced protection against apoptosis. CONCLUSIONS: An IGF-2/IGF-1 receptor autocrine loop operates in beta-cells. GLP-1 increases its activity by augmenting IGF-1 receptor expression and by stimulating secretion; this mechanism is required for GLP-1-induced protection against apoptosis. These findings may lead to novel ways of preventing beta-cell loss in the pathogenesis of diabetes.

Multiparametric brainstem segmentation using a modified multivariate mixture of Gaussians

The human brainstem is a densely packed, complex but highly organised structure. It not only serves as a conduit for long projecting axons conveying motor and sensory information, but also is the location of multiple primary nuclei that control or modulate a vast array of functions, including homeostasis, consciousness, locomotion, and reflexive and emotive behaviours. Despite its importance, both in understanding normal brain function as well as neurodegenerative processes, it remains a sparsely studied structure in the neuroimaging literature. In part, this is due to the difficulties in imaging the internal architecture of the brainstem in vivo in a reliable and repeatable fashion. A modified multivariate mixture of Gaussians (mmMoG) was applied to the problem of multichannel tissue segmentation. By using quantitative magnetisation transfer and proton density maps acquired at 3 T with 0.8 mm isotropic resolution, tissue probability maps for four distinct tissue classes within the human brainstem were created. These were compared against an ex vivo fixated human brain, imaged at 0.5 mm, with excellent anatomical correspondence. These probability maps were used within SPM8 to create accurate individual subject segmentations, which were then used for further quantitative analysis. As an example, brainstem asymmetries were assessed across 34 right-handed individuals using voxel based morphometry (VBM) and tensor based morphometry (TBM), demonstrating highly significant differences within localised regions that corresponded to motor and vocalisation networks. This method may have important implications for future research into MRI biomarkers of pre-clinical neurodegenerative diseases such as Parkinson's disease.

On Rothschild-Stiglitz as competitive pooling

Dubey and Geanakoplos [2002] have developed a theory of competitive pooling, which incorporates adverse selection and signaling into general equilibrium. By recasting the Rothschild-Stiglitz model of insurance in this framework, they find that a separating equilibrium always exists and is unique.We prove that their uniqueness result is not a consequence of the framework, but rather of their definition of refined equilibria. When other types of perturbations are used, the model allows for many pooling allocations to be supported as such: in particular, this is the case for pooling allocations that Pareto dominate the separating equilibrium.

Pseudomonas fluorescens CHA0 produces enantio-pyochelin, the optical antipode of the Pseudomonas aeruginosa siderophore pyochelin.

The siderophore pyochelin is made by a thiotemplate mechanism from salicylate and two molecules of cysteine. In Pseudomonas aeruginosa, the first cysteine residue is converted to its D-isoform during thiazoline ring formation whereas the second cysteine remains in its L-configuration, thus determining the stereochemistry of the two interconvertible pyochelin diastereoisomers as 4'R, 2''R, 4''R (pyochelin I) and 4'R, 2''S, 4''R (pyochelin II). Pseudomonas fluorescens CHA0 was found to make a different stereoisomeric mixture, which promoted growth under iron limitation in strain CHA0 and induced the expression of its biosynthetic genes, but was not recognized as a siderophore and signaling molecule by P. aeruginosa. Reciprocally, pyochelin promoted growth and induced pyochelin gene expression in P. aeruginosa, but was not functional in P. fluorescens. The structure of the CHA0 siderophore was determined by mass spectrometry, thin-layer chromatography, NMR, polarimetry, and chiral HPLC as enantio-pyochelin, the optical antipode of the P. aeruginosa siderophore pyochelin. Enantio-pyochelin was chemically synthesized and confirmed to be active in CHA0. Its potential biosynthetic pathway in CHA0 is discussed.

Sensitization of endothelial cells to TNFα-induced death

RESUME L'angiogénèse tumorale est un processus essentiel au développement des tumeurs. Les intégrines, molécules d'adhésions transmembranaires, sont d'importants effecteurs de l'angiogenèse. En permettant l'adhésion à la matrice extra-cellulaire, les intégrines transmettant des signaux de survie, de migration, et de prolifération. Le facteur de nécrose tumorale α (TNFα) est utilisé pour le traitement régional de cancers chez l'homme. II agit en détruisant sélectivement les vaisseaux angiogéniques. Cependant, son administration systémique chez l'homme est limitée par les réactions de vaso-dilatation sévères qu'il provoque. Le but de mon travail fut de rechercher des conditions permettant la sensibilisation des cellules endothéliales au TNFα et qui pourraient être applicables en clinique, ceci afin d'accroître l'efficacité de cette molécule. Nous avons testé la possibilité d'interférer avec les signaux de survie provenant des intégrines. Pour cela, des cellules endothéliales furent cultivées dans des conditions d'adhésion ou en suspension, ou alors exposées dans des conditions d'adhésion au zoledronate (biphosphonate contenant du nitrogène). Dans ces conditions, les effets du TNFα sur les cellules endothéliales furent étudiés, en particulier l'induction de la mort cellulaire. Dans ce travail, nous montrons que le zoledronate sensibilise les cellules endothéliales à la nécrose induite par TNFα. Cet effet s'accompagne de l'inhibition de la phosphorylation de FAK, PKB, et JNK, ainsi que de l'inhibition de la prénylation des protéines. En revanche, l'activation de NF-kB et p38 n'est pas perturbée. La restoration de la prénylation des protéines empêche la mort des HUVEC traitées par zoledronate et TNFα, et rétablit la phosphorylation de FAK, PKB, et JNK. Des essais d'angiogénèse in vivo montrent que le zoledronate inhibe l'angiogénèse induite par FGF-2. Le zoledronate encapsulé dans des liposomes permet de ralentir la croissance tumorale et synergise avec le TNFα en l'inhibant. L'inihibtion de la prénylation des protéines est un des mécanismes de sensibilisation du zoledronate au TNFα. In vivo, la synergie de leur association sur la croissance tumorale est efficace. Ces résultats encouragent la poursuite de l'étude des effets de ces deux drogues sur la croissance tumorale. SUMMARY The formation of tumor-associated vessels is essential for tumor progression. Cell adhesion molecules of the integrin family are important mediators of angiogenesis, by providing adhesive signals necessary for endothelial cell migration, proliferation and survival. Anti-angiogenic therapies are currently considered as highly promising in the treatment of human cancer. Tumor Necrosis Factor α (TNFα) is used for the regional treatment of human cancer, whose mechanisms of action involved selective disruption of angiogenic tumor vessels. Systemic administration of TNFα in humans, however, induces a severe inflammatory condition that prevents its use far the treatments of tumors localized outside of limbs. The aim of my work was to find strategies to sensitize angiogenic endothelial cells to TNFα-induced death, which could be potentially translated into clinical setting to improve the therapeutic efficacy of TNFα. We specifically tested the hypothesis whether interference with integrin-mediated adhesion and signaling may sensitize endothelial cells to TNFα-induced death. To test this hypothesis we cultured endothelial cells (EC) under conditions of cell-matrix or cell-cell adhesion or exposed matrix-adherent EC to the nitrogen-containing bisphosphonate zoledronate, and characterized the effect on TNFα-mediated signaling events and cell death. We show that zoledronate sensitizes HUVEC to TNFα-induced necrosis-like programmed cell death. This effect was associated with suppression of sustained phosphorylation of PKB and JNK and decreased protein prenylation, whereas TNFα-induced activation of NF-kB and p38 were not inhibited. Restoration of protein prenylation rescued HUVEC from zoledronate and TNFα-induced death, and restored FAK, PKB and JNK phosphorylation. By using in vivo angiogenesis assay we showed that zoledronate suppressed FGF-2-induced angiogenesis. Liposome-encapulated zoledronate partially inhibited tumor growth and synergized with TNFα to fully suppress tumor growth. Taken together, this work has identified protein prenylation as a mechanisms by which zoledronate sensitizes endothelial cells to TNFα-induced death in vitro and provides initial evidence that zoledronate synergizes with TNFα in vivo resulting in improved anti-tumor activity. These results warrant further study of the anti-tumor effects of zoledronate and TNFα and should be further studies in view of their clinical relevance.

Uusi institutionalismi EU-tutkimuksessa : suurista integraatioteorioista päätöksenteon ja verkostojen tutkimukseen

Olli Rehn

Hidden branches: developments in root system architecture.

The root system is fundamentally important for plant growth and survival because of its role in water and nutrient uptake. Therefore, plants rely on modulation of root system architecture (RSA) to respond to a changing soil environment. Although RSA is a highly plastic trait and varies both between and among species, the basic root system morphology and its plasticity are controlled by inherent genetic factors. These mediate the modification of RSA, mostly at the level of root branching, in response to a suite of biotic and abiotic factors. Recent progress in the understanding of the molecular basis of these responses suggests that they largely feed through hormone homeostasis and signaling pathways. Novel factors implicated in the regulation of RSA in response to the myriad endogenous and exogenous signals are also increasingly isolated through alternative approaches such as quantitative trait locus analysis.

Glucose transporters in the 21st Century.

The ability to take up and metabolize glucose at the cellular level is a property shared by the vast majority of existing organisms. Most mammalian cells import glucose by a process of facilitative diffusion mediated by members of the Glut (SLC2A) family of membrane transport proteins. Fourteen Glut proteins are expressed in the human and they include transporters for substrates other than glucose, including fructose, myoinositol, and urate. The primary physiological substrates for at least half of the 14 Glut proteins are either uncertain or unknown. The well-established glucose transporter isoforms, Gluts 1-4, are known to have distinct regulatory and/or kinetic properties that reflect their specific roles in cellular and whole body glucose homeostasis. Separate review articles on many of the Glut proteins have recently appeared in this journal. Here, we provide a very brief summary of the known properties of the 14 Glut proteins and suggest some avenues of future investigation in this area.

The psychostimulant modafinil enhances gap junctional communication in cortical astrocytes.

Sleep-wake cycle is characterized by changes in neuronal network activity. However, for the last decade there is increasing evidence that neuroglial interaction may play a role in the modulation of sleep homeostasis and that astrocytes have a critical impact in this process. Interestingly, astrocytes are organized into communicating networks based on their high expression of connexins, which are the molecular constituents of gap junction channels. Thus, neuroglial interactions should also be considered as the result of the interplay between neuronal and astroglial networks. Here, we investigate the effect of modafinil, a wakefulness-promoting agent, on astrocyte gap junctional communication. We report that in the cortex modafinil injection increases the expression of mRNA and protein of connexin 30 but not those of connexin 43, the other major astroglial connexin. These increases are correlated with an enhancement of intercellular dye coupling in cortical astrocytes, which is abolished when neuronal activity is silenced by tetrodotoxin. Moreover, gamma-hydroxybutyric acid, which at a millimolar concentration induces sleep, has an opposite effect on astroglial gap junctions in an activity-independent manner. These results support the proposition that astroglia may play an important role in complex physiological brain functions, such as sleep regulation, and that neuroglial networking interaction is modified during sleep-wake cycle. This article is part of the Special Issue Section entitled 'Current Pharmacology of Gap Junction Channels and Hemichannels'.