210 research outputs found

    Three-phase traffic theory and two-phase models with a fundamental diagram in the light of empirical stylized facts

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    Despite the availability of large empirical data sets and the long history of traffic modeling, the theory of traffic congestion on freeways is still highly controversial. In this contribution, we compare Kerner's three-phase traffic theory with the phase diagram approach for traffic models with a fundamental diagram. We discuss the inconsistent use of the term "traffic phase" and show that patterns demanded by three-phase traffic theory can be reproduced with simple two-phase models, if the model parameters are suitably specified and factors characteristic for real traffic flows are considered, such as effects of noise or heterogeneity or the actual freeway design (e.g. combinations of off- and on-ramps). Conversely, we demonstrate that models created to reproduce three-phase traffic theory create similar spatiotemporal traffic states and associated phase diagrams, no matter whether the parameters imply a fundamental diagram in equilibrium or non-unique flow- density relationships. In conclusion, there are different ways of reproducing the empirical stylized facts of spatiotemporal congestion patterns summarized in this contribution, and it appears possible to overcome the controversy by a more precise definition of the scientific terms and a more careful comparison of models and data, considering effects of the measurement process and the right level of detail in the traffic model used.Comment: 18 pages in the published article, 13 figures, 2 table

    Absence of an adipogenic effect of rosiglitazone on mature 3T3-L1 adipocytes: increase of lipid catabolism and reduction of adipokine expression

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    Aims/hypothesis: The thiazolidinedione (TZD) rosiglitazone is a peroxisome proliferator-activated receptor-¿ agonist that induces adipocyte differentiation and, hence, lipid accumulation. This is in apparent contrast to the long-term glucose-lowering, insulin-sensitising effect of rosiglitazone. We tested whether the action of rosiglitazone involves specific effects on mature adipocytes, which are different from those on preadipocytes. Materials and methods: Differentiated mature 3T3-L1 adipocytes were used as an in vitro model. Transcriptomics, proteomics and assays of metabolism were applied to assess the effect of rosiglitazone in different insulin and glucose conditions. Results: Rosiglitazone does not induce an increase, but rather a decrease in the lipid content of mature adipocytes. Analysis of transcriptome data, confirmed by quantitative RT-PCR and measurements of lipolysis, indicates that an altered energy metabolism may underlie this change. The pathway analysis shows a consistent picture dominated by lipid catabolism. In addition, we confirmed at both mRNA level and protein level that rosiglitazone represses adipokine expression and production, except for genes encoding adiponectin and apolipoprotein E. Moreover, transcriptome changes indicate that a general repression of genes encoding secreted proteins occurs. Conclusions/ interpretation: Our findings suggest that the change of adiposity as seen in vivo reflects a shift in balance between the different effects of TZDs on preadipocytes and on mature adipocytes, while the changes in circulating adipokine levels primarily result from an effect on mature adipocyte

    Loss of NK Stimulatory Capacity by Plasmacytoid and Monocyte-Derived DC but Not Myeloid DC in HIV-1 Infected Patients

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    Dendritic cells (DC) are potent inducers of natural killer (NK) cells. There are two distinct populations in blood, myeloid (mDC) and plasmacytoid (pDC) but they can also be generated In vitro from monocytes (mdDC). Although it is established that blood DC are lost in HIV-1 infection, the full impact of HIV-1 infection on DC-NK cell interactions remains elusive. We thus investigated the ability of pDC, mDC, and mdDC from viremic and anti-retroviral therapy-treated aviremic HIV-1+ patients to stimulate various NK cell functions. Stimulated pDC and mdDC from HIV-1+ patients showed reduced secretion of IFN-α and IL-12p70 respectively and their capacity to stimulate expression of CD25 and CD69, and IFN-γ secretion in NK cells was also reduced. pDC activation of NK cell degranulation in response to a tumour cell line was severely reduced in HIV-1+ patients but the ability of mDC to activate NK cells was not affected by HIV-1 infection, with the exception of HLA-DR induction. No differences were observed between viremic and aviremic patients indicating that anti-retroviral therapy had minimal effect on restoration on pDC and mdDC-mediated activation of NK cells. Results from this study provide further insight into HIV-1 mediated suppression of innate immune functions

    The Epidermal Growth Factor Receptor Is Involved in Angiotensin II But Not Aldosterone/Salt-Induced Cardiac Remodelling

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    Experimental and clinical studies have shown that aldosterone/mineralocorticoid receptor (MR) activation has deleterious effects in the cardiovascular system; however, the signalling pathways involved in the pathophysiological effects of aldosterone/MR in vivo are not fully understood. Several in vitro studies suggest that Epidermal Growth Factor Receptor (EGFR) plays a role in the cardiovascular effects of aldosterone. This hypothesis remains to be demonstrated in vivo. To investigate this question, we analyzed the molecular and functional consequences of aldosterone exposure in a transgenic mouse model with constitutive cardiomyocyte-specific overexpression of a mutant EGFR acting as a dominant negative protein (DN-EGFR). As previously reported, Angiotensin II-mediated cardiac remodelling was prevented in DN-EGFR mice. However, when chronic MR activation was induced by aldosterone-salt-uninephrectomy, cardiac hypertrophy was similar between control littermates and DN-EGFR. In the same way, mRNA expression of markers of cardiac remodelling such as ANF, BNF or β-Myosin Heavy Chain as well as Collagen 1a and 3a was similarly induced in DN-EGFR mice and their CT littermates. Our findings confirm the role of EGFR in AngII mediated cardiac hypertrophy, and highlight that EGFR is not involved in vivo in the damaging effects of aldosterone on cardiac function and remodelling

    The Kidneys and Aldosterone/Mineralocorticoid Receptor System in Salt-Sensitive Hypertension

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    Strong evidence supports the ability of the aldosterone/mineralocorticoid receptor (MR) system to dominate long-term blood pressure control. It is also increasingly recognized as an important mediator of cardiovascular and renal diseases, particularly in the presence of excessive salt intake. In a subgroup of individuals with metabolic syndrome, adipocyte-derived aldosterone-releasing factors cause inappropriate secretion of aldosterone in the adrenal glands during salt loading, resulting in the development of salt-induced hypertension and cardiac and renal damage. On the other hand, emerging data reveal that aldosterone is not a sole regulator of MR activity. We have identified the signaling crosstalk between MR and small GTPase Rac1 as a novel pathway to facilitate MR signaling. Such a local control system for MR can also be relevant to the pathogenesis of salt-sensitive hypertension, and future studies will clarify the detailed mechanism for the intricate regulation of the aldosterone/MR cascade

    The Interplay Between Post-Critical Beliefs and Anxiety: An Exploratory Study in a Polish Sample

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    The present research investigates the relationship between anxiety and the religiosity dimensions that Wulff (Psychology of religion: classic and contemporary views, Wiley, New York, 1991; Psychology of religion. Classic and contemporary views, Wiley, New York, 1997; Psychologia religii. Klasyczna i współczesna, Wydawnictwo Szkolne i Pedagogiczne, Warszawa, 1999) described as Exclusion vs. Inclusion of Transcendence and Literal vs. Symbolic. The researchers used the Post-Critical Belief scale (Hutsebaut in J Empir Theol 9(2):48–66, 1996; J Empir Theol 10(1):39–54, 1997) to measure Wulff’s religiosity dimensions and the IPAT scale (Krug et al. 1967) to measure anxiety. Results from an adult sample (N = 83) suggest that three dimensions show significant relations with anxiety. Orthodoxy correlated negatively with suspiciousness (L) and positively with guilt proneness (O) factor—in the whole sample. Among women, Historical Relativism negatively correlated with suspiciousness (L), lack of integration (Q3), general anxiety and covert anxiety. Among men, Historical Relativism positively correlated with tension (Q4) and emotional instability (C), general anxiety, covert anxiety and overt anxiety. External Critique was correlated with suspiciousness (L) by men

    Neural Circuitry of Emotional and Cognitive Conflict Revealed through Facial Expressions

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    Neural systems underlying conflict processing have been well studied in the cognitive realm, but the extent to which these overlap with those underlying emotional conflict processing remains unclear. A novel adaptation of the AX Continuous Performance Task (AX-CPT), a stimulus-response incompatibility paradigm, was examined that permits close comparison of emotional and cognitive conflict conditions, through the use of affectively-valenced facial expressions as the response modality.Brain activity was monitored with functional magnetic resonance imaging (fMRI) during performance of the emotional AX-CPT. Emotional conflict was manipulated on a trial-by-trial basis, by requiring contextually pre-cued facial expressions to emotional probe stimuli (IAPS images) that were either affectively compatible (low-conflict) or incompatible (high-conflict). The emotion condition was contrasted against a matched cognitive condition that was identical in all respects, except that probe stimuli were emotionally neutral. Components of the brain cognitive control network, including dorsal anterior cingulate cortex (ACC) and lateral prefrontal cortex (PFC), showed conflict-related activation increases in both conditions, but with higher activity during emotion conditions. In contrast, emotion conflict effects were not found in regions associated with affective processing, such as rostral ACC.These activation patterns provide evidence for a domain-general neural system that is active for both emotional and cognitive conflict processing. In line with previous behavioural evidence, greatest activity in these brain regions occurred when both emotional and cognitive influences additively combined to produce increased interference

    Workplace violence in a large correctional health servce in New South Wales, Australia: a retrospective review of incident management records

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    BackgroundLittle is known about workplace violence among correctional health professionals. This studyaimed to describe the patterns, severity and outcomes of incidents of workplace violenceamong employees of a large correctional health service, and to explore the help-seekingbehaviours of staff following an incident.MethodsThe study setting was Justice Health, a statutory health corporation established to providehealth care to people who come into contact with the criminal justice system in New SouthWales, Australia. We reviewed incident management records describing workplace violenceamong Justice Health staff. The three-year study period was 1/7/2007-30/6/2010.ResultsDuring the period under review, 208 incidents of workplace violence were recorded. Verbalabuse (71%) was more common than physical abuse (29%). The most (44%) incidents ofworkplace violence (including both verbal and physical abuse) occurred in adult maleprisons, although the most (50%) incidents of physical abuse occurred in a forensic hospital.Most (90%) of the victims were nurses and two-thirds were females. Younger employees andmales were most likely to be a victim of physical abuse. Preparing or dispensing medicationand attempting to calm and/or restrain an aggressive patient were identified as ‘high risk’work duties for verbal abuse and physical abuse, respectively. Most (93%) of the incidents ofworkplace violence were initiated by a prisoner/patient. Almost all of the incidents receivedeither a medium (46%) or low (52%) Severity Assessment Code. Few victims of workplaceviolence incurred a serious physical injury – there were no workplace deaths during the studyperiod. However, mental stress was common, especially among the victims of verbal abuse(85%). Few (6%) victims of verbal abuse sought help from a health professional.ConclusionsAmong employees of a large correctional health service, verbal abuse in the workplace wassubstantially more common than physical abuse. The most incidents of workplace violenceoccurred in adult male prisons. Review of the types of adverse health outcomes experiencedby the victims of workplace violence and the assessments of severity assigned to violentincidents suggests that, compared with health care settings in the community, correctionalsettings are fairly safe places in which to practice

    Influenza A Virus Inhibits Type I IFN Signaling via NF-κB-Dependent Induction of SOCS-3 Expression

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    The type I interferon (IFN) system is a first line of defense against viral infections. Viruses have developed various mechanisms to counteract this response. So far, the interferon antagonistic activity of influenza A viruses was mainly observed on the level of IFNβ gene induction via action of the viral non-structural protein 1 (NS1). Here we present data indicating that influenza A viruses not only suppress IFNβ gene induction but also inhibit type I IFN signaling through a mechanism involving induction of the suppressor of cytokine signaling-3 (SOCS-3) protein. Our study was based on the observation that in cells that were infected with influenza A virus and subsequently stimulated with IFNα/β, phosphorylation of the signal transducer and activator of transcription protein 1 (STAT1) was strongly reduced. This impaired STAT1 activation was not due to the action of viral proteins but rather appeared to be induced by accumulation of viral 5′ triphosphate RNA in the cell. SOCS proteins are potent endogenous inhibitors of Janus kinase (JAK)/STAT signaling. Closer examination revealed that SOCS-3 but not SOCS-1 mRNA levels increase in an RNA- and nuclear factor kappa B (NF-κB)-dependent but type I IFN-independent manner early in the viral replication cycle. This direct viral induction of SOCS-3 mRNA and protein expression appears to be relevant for suppression of the antiviral response since in SOCS-3 deficient cells a sustained phosphorylation of STAT1 correlated with elevated expression of type I IFN-dependent genes. As a consequence, progeny virus titers were reduced in SOCS-3 deficient cells or in cells were SOCS-3 expression was knocked-down by siRNA. These data provide the first evidence that influenza A viruses suppress type I IFN signaling on the level of JAK/STAT activation. The inhibitory effect is at least in part due to the induction of SOCS-3 gene expression, which results in an impaired antiviral response
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