A right to a national space of communication? : on Stateless nations, their right to a space of communication of their own

Hem establert les bases metodològiques i teòriques per investigar la pregunta “Tenen les nacions sense estat el dret de controlar el seu propi espai de comunicació?”. La investigació ajusta el concepte d’espai de comunicació a la teoria política, cercant els seus límits en els drets individuals i, des de la perspectiva del liberalisme 2, aportant la justificació del seu control en quant que plataforma que incideix en la conservació i supervivència d’una cultura nacional. El primer article i fase de la tesi és l’adaptació i definició del concepte espai de comunicació. Fins ara, la recerca ha proposat diferents models d’espai de comunicació entenent si es tracta d’una visió emfatitzant la distribució i la producció de material marcat amb els símbols de la identitat nacional de la societat emissora, o bé si emfatitza la idea d’un espai de circulació de fluxos comunicatiu ajustat a un territori tradicionalment vinculat a una identitat nacional o nació sense estat. Igualment, es distingeix la dimensió d’emissió –sortir del territori al món- i la de recepció –fluxos informatius rebuts des del món al territori, concretament, al ciutadà; el paper d’intervenció de les institucions democràtiques és diferent en una dimensió o una altra i, per tant, també són diferents els drets afectats i les teories o principis que neguen o justifiquen el control de l’espai de comunicació. També s’ha indagat en les teories sobre els efectes cognitius dels mitjans de comunicació per relacionar-los amb la construcció nacional com a cohesió simbòlica i cultural. Si bé els mitjans no poden fer canviar de pensament immediatament, sí que poden conformar a llarg termini una percepció nacional general. Una comunitat és imaginada, donada la distància física dels seus components, i la comunicació social és, juntament amb l’educació, el principal factor de construcció nacional, avui en dia.

Mucosal immunology and models of mucosal HIV infection

The mucosa associated lymphoid tissue regulates and coordinates immune responses against mucosal pathogens. Mucosal tissues are the major targets exposed to HIV during transmission. In this paper we describe in vitro models of HIV mucosal infection using human explants to investigate target cells within this tissue.

Vascular integrins: pleiotropic adhesion and signaling molecules in vascular homeostasis and angiogenesis.

New blood vessel formation, a process referred to as angiogenesis, is essential for embryonic development and for many physiological and pathological processes during postnatal life, including cancer progression. Endothelial cell adhesion molecules of the integrin family have emerged as critical mediators and regulators of angiogenesis and vascular homeostasis. Integrins provide the physical interaction with the extracellular matrix necessary for cell adhesion, migration and positioning, and induction of signaling events essential for cell survival, proliferation and differentiation. Antagonists of integrin alpha V beta 3 suppress angiogenesis in many experimental models and are currently tested in clinical trials for their therapeutic efficacy against angiogenesis-dependent diseases, including cancer. Furthermore, interfering with signaling pathways downstream of integrins results in suppression of angiogenesis and may have relevant therapeutic implications. In this article we review the role of integrins in endothelial cell function and angiogenesis. In the light of recent advances in the field, we will discuss their relevance as a therapeutic target to suppress tumor angiogenesis.

Persistent inhibition of FLIP(L) expression by lentiviral small hairpin RNA delivery restores death-receptor-induced apoptosis in neuroblastoma cells.

Neuroblastoma represents the most common and deadly solid tumour of childhood, which disparate biological and clinical behaviour can be explained by differential regulation of apoptosis. To understand mechanisms underlying death resistance in neuroblastoma cells, we developed small hairpin of RNA produced by lentiviral vectors as tools to selectively interfere with FLIP(L), a major negative regulator of death receptor-induced apoptosis. Such tools revealed highly efficient in interfering with FLIP(L) expression and function as they almost completely repressed endogenous and/or exogenously overexpressed FLIP(L) protein and fully reversed FLIP(L)-mediated TRAIL resistance. Moreover, interference with endogenous FLIP(L) and FLIP(S) significantly restored FasL sensitivity in SH-EP neuroblastoma cell line. These results reveal the ability of lentivirus-mediated shRNAs to specifically and persistently interfere with FLIP expression and support involvement of FLIP in the regulation of death receptor-mediated apoptosis in neuroblastoma cells. Combining such tools with other therapeutic modalities may improve treatment of resistant tumours such as neuroblastoma.

L'aprenentatge basat en problemes en models híbrids de docència-aprenentatge

La Facultat de Ciències de la Salut i de la Vida ha utilitzat des de 2004 la metodologia d'aprenentatge basat en problemes (en endavant ABP) com a mètode docent en els seus estudis de Biologia. En aquest període hem après algunes de les claus de l'aplicació del mètode en els nostres estudis. En primer lloc, cal disposar d'elements formatius que afavoreixin la formació dels tutors que participin en el projecte. Per assolir aquest objectiu hem dissenyat un portal on els nostres professors poden disposar de materials útils per a la seva activitat, així com de documents que permetin entendre millor el que suposa l'ABP. En segon lloc, el projecte tenia l'objectiu de dissenyar i avaluar activitats que permetessin integrar les pràctiques de laboratori en la lògica de la resolució de problemes pròpia de l'ABP. En aquest sentit vam dissenyar dues activitats en el tercer curs de la llicenciatura que anomenaren aprenentatge basat en el laboratori (ABL). Per aquest motiu es van dissenyar problemes que tinguessin una primera part de resolució a l'aula en grup de tutoria i una segona que obligués els estudiants a realitzar experiments de laboratori dirigits a entendre i resoldre les qüestions plantejades al grup de tutoria. L'ABL-1 fou un projecte de biologia cel·lular i destinat a aprofundir en els mecanismes implicats en els fenòmens de diferenciació dels miòcits. L'ABL-2 era un projecte conjunt dels professors de Fisiologia vegetal, Bioestadística i Microbiologia. En aquest cas es desitjava que els estudiants plantegessin la resolució a un problema que suposava la manipulació genètica de cèl·lules vegetals per fer possible que produïssin una substància específica, l'escopolamina. Finalment els estudiants havien d'escriure un article original com a projecte final de cada ABL. Els resultats dels dos anys d'experimentació han esta altament satisfactoris, d'acord amb les enquestes completades per alumnes i professors.

Model de Pràcticum Integrador (MPI) i ECTS : consolidació i conciliació de models

Aquest projecte es va iniciar amb la finalitat d’extendre i consolidar l’aplicació del Model de Pràcticum Integrador (MPI) a la majoria dels pràcticums de les titulacions de pedagogia, psicopedagogia i educació social de la Facultat de Ciències de l’Educació de la nostra universitat. Aquest Model s’havia iniciat en els darrers anys i ja s’havia comprovat la seva l’eficiència. L’MPI es fonamenta en el convenciment que l’assoliment de les competències professionals és bàsic i que aquestes es poden desenvolupar durant el pràcticum. En aquest nou model de pràctiques, els estudiants treballen en equips interdisciplinars per projectes, els tutors/es de la facultat conformen un equip de treball amb els tutors/es dels centres, dissenyen els plans d’acollida i de seguiment, i es fan les tutories de seguiment i treball en el centre entre totes les parts implicades. Els objectius plantejats en els dos anys de durada de l’MQD2006 eren: 1)Eliminar les dificultats tecnicoadministratives de la facultat que dificulten l’ampliació i consolidació del model MPI. 2)Comunicar i prestigiar el model MPI i la xarxa de centres d’excel·lència entre els estudiants, el professorat de la facultat i els propis centres. 3)Promoure la col·laboració, l’intercanvi de coneixement i els projectes d’innovació i recerca facultat-centres posant en contacte els grups de treball de la facultat i els centres, i mostrant els seus potencials. 4)Estructurar el nou model segons el model ECTs. 5)Analitzar i aprofundir en l’aplicació del treball per competències del nou model.

Endothelial cell integrins and COX-2: mediators and therapeutic targets of tumor angiogenesis.

Vascular integrins are essential regulators and mediators of physiological and pathological angiogenesis, including tumor angiogenesis. Integrins provide the physical interaction with the extracellular matrix (ECM) necessary for cell adhesion, migration and positioning, and induce signaling events essential for cell survival, proliferation and differentiation. Integrins preferentially expressed on neovascular endothelial cells, such as alphaVbeta3 and alpha5beta1, are considered as relevant targets for anti-angiogenic therapies. Anti-integrin antibodies and small molecular integrin inhibitors suppress angiogenesis and tumor progression in many animal models, and are currently tested in clinical trials as anti-angiogenic agents. Cyclooxygense-2 (COX-2), a key enzyme in the synthesis of prostaglandins and thromboxans, is highly up-regulated in tumor cells, stromal cells and angiogenic endothelial cells during tumor progression. Recent experiments have demonstrated that COX-2 promotes tumor angiogenesis. Chronic intake of nonsteroidal anti-inflammatory drugs and COX-2 inhibitors significantly reduces the risk of cancer development, and this effect may be due, at least in part, to the inhibition of tumor angiogenesis. Endothelial cell COX-2 promotes integrin alphaVbeta3-mediated endothelial cell adhesion, spreading, migration and angiogenesis through the prostaglandin-cAMP-PKA-dependent activation of the small GTPase Rac. In this article, we review the role of integrins and COX-2 in angiogenesis, their cross talk, and discuss implications relevant to their targeting to suppress tumor angiogenesis.

Infections and functional impairment in nursing home residents: a reciprocal relationship.

OBJECTIVES: To determine the relationship between infections and functional impairment in nursing home residents. DESIGN: Prospective cohort study (follow-up period, 6 months). SETTING: Thirty-nine nursing homes in western Switzerland. PARTICIPANTS: A total of 1,324 residents aged 65 and older (mean age 85.7; 76.6% female) who agreed to participate, or their proxies, by oral informed consent. MEASUREMENTS: Functional status measured every 3 months. Two different outcomes were used: (a) functional decline defined as death or decreased function at follow-up and (b) functional status score using a standardized measure. RESULTS: At the end of follow-up, mortality was 14.6%, not different for those with and without infection (16.2% vs 13.1%, P=.11). During both 3-month periods, subjects with infection had higher odds of functional decline, even after adjustment for baseline characteristics and occurrence of a new illness (adjusted odds ratio (AOR)=1.6, 95% confidence interval (CI)=1.2-2.2, P=.002, and AOR=1.5, 95% CI=1.1-2.0, P=.008, respectively). The odds of decline increased in a stepwise fashion in patients with zero, one, and two or more infections. The analyses predicting functional status score (restricted to subjects who survived) gave similar results. A survival analysis predicting time to first infection confirmed a stepwise greater likelihood of infection in subjects with moderate and severe impairment at baseline than in subjects with no or mild functional impairment at baseline. CONCLUSION: Infections appear to be both a cause and a consequence of functional impairment in nursing home residents. Further studies should be undertaken to investigate whether effective infection control programs can also contribute to preventing functional decline, an important component of these residents' quality of life.

Analysis of nonlinear noisy integrate & fire neuron models: blow-up and steady states

Nonlinear Noisy Leaky Integrate and Fire (NNLIF) models for neurons networks can be written as Fokker-Planck-Kolmogorov equations on the probability density of neurons, the main parameters in the model being the connectivity of the network and the noise. We analyse several aspects of the NNLIF model: the number of steady states, a priori estimates, blow-up issues and convergence toward equilibrium in the linear case. In particular, for excitatory networks, blow-up always occurs for initial data concentrated close to the firing potential. These results show how critical is the balance between noise and excitatory/inhibitory interactions to the connectivity parameter.

Evolutionary and convergence stability for continuous phenotypes in finite populations derived from two-allele models.

The evolution of a quantitative phenotype is often envisioned as a trait substitution sequence where mutant alleles repeatedly replace resident ones. In infinite populations, the invasion fitness of a mutant in this two-allele representation of the evolutionary process is used to characterize features about long-term phenotypic evolution, such as singular points, convergence stability (established from first-order effects of selection), branching points, and evolutionary stability (established from second-order effects of selection). Here, we try to characterize long-term phenotypic evolution in finite populations from this two-allele representation of the evolutionary process. We construct a stochastic model describing evolutionary dynamics at non-rare mutant allele frequency. We then derive stability conditions based on stationary average mutant frequencies in the presence of vanishing mutation rates. We find that the second-order stability condition obtained from second-order effects of selection is identical to convergence stability. Thus, in two-allele systems in finite populations, convergence stability is enough to characterize long-term evolution under the trait substitution sequence assumption. We perform individual-based simulations to confirm our analytic results.

Effects of Bayluscide WP 70® on the Survival and Water-leaving Behaviour of Biomphalaria straminea, Snail Host of Schistosomiasis in Northeast Brazil

The toxic and behavioural effects of niclosamide (Bayluscide WP 70®) on Biomphalaria straminea from a highly endemic area of schistosomiasis in northeastern Brazil were investigated through laboratory bioassays. The LD50 and LD90 were 0.114 mg/l and 0.212 mg/l, respectively. Water-leaving behaviour occurred among 14% to 30% of the snails in the presence of sublethal doses of niclosamide and among 16% of the controls. It was concluded that both the relatively low susceptibility to niclosamide and water-leaving behaviour of local B. straminea may be responsible for the recolonization of transmission foci after mollusciciding. It was suggested that recently improved measures of snail control, such as controlled-release formulations of niclosamide and plant molluscicides should be considered in areas where snail control is recommended

IDH1/IDH2 mutations predict survival in glioma and AML

Mutations in the isocitrate dehydrogenase family genes 1 or 2 (IDH1/2) have been discovered by high through put sequencing approaches inglioma and acute myeloid leukemia (AML) and related myeloproliferativeneoplasms. In both diseases, the discovery of IDH mutations has identifieda prognostically new subtype with distinct pathogenetic evolution. Ingliomas mutations are mostly found in IDH1 (>90%). They are infrequent inprimary glioblastoma (GBM) (<10%), but common in secondary GBM thatevolve from lower grade glioma (60−90%). Mutations in IDH1 precede p53mutations or 1p/19q co-deletions in sporadic low grade glioma, hence arean early evant. Co-deletions of 1p/19q, characteristic for oligodenroglioma,are highly associated with IDH1/2 mutations, while they are mutuallyexclusive with EGFR amplifications, a hall mark of primary GBM. IDH1 or 2mutations are associated with younger patient age, but absent in childhoodgliomas, and have a better prognosis that seems to be consistent in gradeII through IV gliomas. In myeloid malignancies mutations are more likelyin IDH2 and are found in de novo and secondary AML (12−18%) andpre-leukemic clonal malignancies (5% chronic; 20% transformed). IDH1/2mutations are strongly associated with NPM1 mutations that are found in30% of novo cytogenetically normal AML. In CN-AML with mutated NPM1,without FLT3 internal tandem duplication (ITD) IDH mutations constitutean adverse prognostic factor. Mutations in the metabolic enzymes IDH1 or2 result in a neomorphic reaction, generating high levels of the metabolite2-hydroxyglutarate (2-HG). IDH mutations are mutually exclusive with TET2mutations in myeloid malignancies that led to the discovery that high levelsof 2-HG inhibit the a-KG dependent dioxygenase TET2. TET2 is involved inepigenetic regulation and mediates demethylation of DNA. This mechanismis in accordance with the association of a methylator phenotype with loss offunction of TET2 by mutation or indirectly by mutation of IDH1/2 in myeloidmalignancies and gliomas, respectively.Metabolism meets Epigenetics. These discoveries will have importantclinical implications: IDH1/2 mutants may serve as unique targets fortherapy. Further, the high concentrations of the onco-metabolite 2-HGgenerated by IDH1/2 mutants, may serve as biomarker in the serum ofpatients with myeloid malignancies and may be amenable by magneticresonance spectroscopy in glioma patients.

Technology, business models and network structure in the airline industry

Network airlines have been increasingly focusing their operations on hub airports through the exploitation of connecting traffic, allowing them to take advantage of economies of traffic density, which are unequivocal in the airline industry. Less attention has been devoted to airlines' decisions on point-to-point thin routes, which could be served using different aircraft technologies and different business models. This paper examines, both theoretically and empirically, the impact on airlines' networks of the two major innovations in the airline industry in the last two decades: the regional jet technology and the low-cost business model. We show that, under certain circumstances, direct services on point-to-point thin routes can be viable and thus airlines may be interested in deviating passengers out of the hub. Keywords: regional jet technology; low-cost business model; point-to-point network; hub-and-spoke network JEL Classi…fication Numbers: L13; L2; L93

Estimation of parametric and nonparametric models for univariate claim severity distributions - an approach using R

This paper presents an analysis of motor vehicle insurance claims relating to vehicle damage and to associated medical expenses. We use univariate severity distributions estimated with parametric and non-parametric methods. The methods are implemented using the statistical package R. Parametric analysis is limited to estimation of normal and lognormal distributions for each of the two claim types. The nonparametric analysis presented involves kernel density estimation. We illustrate the benefits of applying transformations to data prior to employing kernel based methods. We use a log-transformation and an optimal transformation amongst a class of transformations that produces symmetry in the data. The central aim of this paper is to provide educators with material that can be used in the classroom to teach statistical estimation methods, goodness of fit analysis and importantly statistical computing in the context of insurance and risk management. To this end, we have included in the Appendix of this paper all the R code that has been used in the analysis so that readers, both students and educators, can fully explore the techniques described