The Spread of Infectious Disease with Household-Structure on the Complex Networks

In this paper we study the household-structure SIS epidemic spreading on general complex networks. The household structure gives us the way to distinguish inner and the outer infection rate. Unlike household-structure models on homogenous networks, such as regular and random networks, here we consider heterogeneous networks with arbitrary degree distribution p(k). First we introduce the epidemic model. Then rate equations under mean field appropriation and computer simulations are used here to analyze our model. Some unique phenomena only existing in divergent network with household structure is found, while we also get some similar conclusions that some simple geometrical quantities of networks have important impression on infection property of infectous disease. It seems that in our model even when local cure rate is greater than inner infection rate in every household, disease still can spread on scale-free network. It implies that no disease is spreading in every single household, but for the whole network, disease is spreading. Since our society network seems like this structure, maybe this conclusion remind us that during disease spreading we should pay more attention on network structure than local cure condition.Comment: 12 pages, 2 figure

A model for delayed emission in a very-high energy gamma-ray flare in Markarian 501

Recently, the MAGIC collaboration reported evidence for a delay in the arrival times of photons of different energies during a gamma-ray flare from the blazar Markarian 501 on 2005 July 9. We apply a homogeneous synchrotron self-Compton (SSC) model under the assumption that the blob containing relativistic electrons was observed in its acceleration phase. This modified SSC model predicts the appearance of a gamma-ray flare first at lower energies and subsequently at higher energies. Based on the reported time delay of approx. 240 s between the flare observed at 190 GeV and 2.7 TeV, we predict a delay on the order of 1 h if observed between 10 GeV and 100 GeV. Such delay timescales can be tested in the future by simultaneous flare observations with the Gamma Ray Large Area Space Telescope (GLAST) and Cherenkov telescopes.Comment: 4 pages, no figures, Astronomy & Astrophysics in pres

TeV blazar variability: the firehose instability?

Recently observed minute timescale variability of blazar emission at TeV energies has imposed severe constraints on jet models and TeV emission mechanisms. We focus on a robust jet instability to explain this variability. As a consequence of the bulk outflow of the jet plasma, the pressure is likely to be anisotropic, with the parallel pressure $P_{||}$ in the forward jet direction exceeding the perpendicular pressure $P_{\perp}$. Under these circumstances, the jet is susceptible to the firehose instability, which can cause disruptions in the large scale jet structure and result in variability of the observed radiation. For a realistic range of parameters, we find that the growth timescale of the firehose instability is $\approx$ a few minutes, in good agreement with the observed TeV variability timescales for Mrk 501 (Albert et al. 2007) and PKS 2155-304 (Aharonian et al. 2007).Comment: Accepted for publication, MNRA

Permit – Ein neues Herbizid zur Bekämpfung von Cyperus esculentus in Mais

Permit mit dem Wirkstoff Halosulfuron (750 g/kg WG) ist ein neues Maisherbizid. Die Annex I Listung liegt seit Oktober 2013 vor. Bei der Kontrolle des schwer bekämpfbaren Erdmandelgrases (Cyperus esculentus) nimmt Permit eine Sonderstellung ein. Erdmandelgras ist ein invasiver Neophyt aus der Familie der Cyperaceae (Sauergräser). Spezifische Gräserherbizide, die zur Bekämpfung von Poaceae (Süßgräser) eingesetzt werden, haben gegen Cyperaceae eine Wirkungslücke. Die Vermehrung erfolgt rasant und in Deutschland ausschließlich über Wurzelknollen (Mandeln) im Boden. Die Befallsflächen haben in Deutschland in den letzten Jahren stark zugenommen, betroffen ist vor allem Niedersachsen. Permit wurde mit Aufwandmengen von 30-50 g/ha als Einmalbehandlung sowie im Splittingverfahren in insgesamt 7 Versuchen zur Bekämpfung von Erdmandelgras in Mais getestet. Entscheidend für den Bekämpfungserfolg war der Applikationstermin. Hohe Wirkungsgrade wurden mit 30-50 g/ha Permit als Soloanwendung zu BBCH 16 des Maises erzielt (Wirkungsgrade 94-98 %), sowie durch das Splittingverfahren im 4- und 6-Blattstadium des Maises (Wirkungsgrade 94-99 %). Da Erdmandelgras in Mais häufig in mehreren Wellen aufläuft, bietet das Splittingverfahren teilweise eine höhere Wirkungssicherheit. Permit bietet damit neue Möglichkeiten, Erdmandelgras wirkungsvoll in Mais zu bekämpfen und schließt damit eine entscheidende Wirkungslücke der zurzeit verfügbaren Maisherbizide. Permit – A new herbicide for control of Cyperus esculentus in maizePermit, containing the active ingredient halosulfuron (750 g/kg WG) is a new herbicide in maize. It is listed in Annex I since October 2013. Permit plays a special role when dealing with the hard to control weed yellow nutsedge (Cyperus esculentus). Yellow nutsedge is an invasive plant belonging to the family Cyperaceae (sedges). Specific graminicides used to control Poaceae (sweet grasses) are not effective against Cyperacea. Propagation is rapid and occurs exclusively via tubers formed in the soil. Affected areas in Germany grow rapidly, especially in Lower-Saxony. Application rates from 30-50 g/ha Permit were tested in solo or split application in 7 trials to control Cyperus esculentus in maize. Application timing proved critical for successful control. High levels of control were achieved with 30-50 g/ha Permit with single applications at BBCH 16 (efficacy 94-98%) as well as with split applications at BBCH 14 and 16 of the crop (efficacy 94-99%). Because yellow nutsedge often emerges in multiple waves, the split application provides more reliable control. Permit offers new opportunities to effectively control Cyperus esculentus in maize and thus closes an important gap in the weed spectrum of currently available maize herbicides

TGFβ signaling is associated with changes in inflammatory gene expression and perineuronal net degradation around inhibitory neurons following various neurological insults.

Brain damage due to stroke or traumatic brain injury (TBI), both leading causes of serious long-term disability, often leads to the development of epilepsy. Patients who develop post-injury epilepsy tend to have poor functional outcomes. Emerging evidence highlights a potential role for blood-brain barrier (BBB) dysfunction in the development of post-injury epilepsy. However, common mechanisms underlying the pathological hyperexcitability are largely unknown. Here, we show that comparative transcriptome analyses predict remodeling of extracellular matrix (ECM) as a common response to different types of injuries. ECM-related transcriptional changes were induced by the serum protein albumin via TGFβ signaling in primary astrocytes. In accordance with transcriptional responses, we found persistent degradation of protective ECM structures called perineuronal nets (PNNs) around fast-spiking inhibitory interneurons, in a rat model of TBI as well as in brains of human epileptic patients. Exposure of a naïve brain to albumin was sufficient to induce the transcriptional and translational upregulation of molecules related to ECM remodeling and the persistent breakdown of PNNs around fast-spiking inhibitory interneurons, which was contingent on TGFβ signaling activation. Our findings provide insights on how albumin extravasation that occurs upon BBB dysfunction in various brain injuries can predispose neural circuitry to the development of chronic inhibition deficits

Continuity and Change in Howard S. Becker's work: An Interview with Howard S. Becker

Howard S. Becker is one of the foremost sociologists of the second half of the twentieth century. Although he is perhaps best known for research on deviance and his book Outsiders, this constitutes only a very small fraction of his earliest work. This interview looks at some of the continuities and cores of his work over ?fifty years. Becker highlights how his work maintains the same core concerns, although new interests have been added over time. At the core is a concern with 'work' and 'doing things together.' Becker provides many concrete stories from the past and also raises issues about the nature of doing theory and research, how he writes and produces his studies, and the problems attached to the professionalization of sociology. His writing on art and culture can be seen as assuming a major position in his later work, but he does not identify with either postmodernism or cultural studies

A self-consistent approach to measure preferential attachment in networks and its application to an inherent structure network

Preferential attachment is one possible way to obtain a scale-free network. We develop a self-consistent method to determine whether preferential attachment occurs during the growth of a network, and to extract the preferential attachment rule using time-dependent data. Model networks are grown with known preferential attachment rules to test the method, which is seen to be robust. The method is then applied to a scale-free inherent structure network, which represents the connections between minima via transition states on a potential energy landscape. Even though this network is static, we can examine the growth of the network as a function of a threshold energy (rather than time), where only those transition states with energies lower than the threshold energy contribute to the network.For these networks we are able to detect the presence of preferential attachment, and this helps to explain the ubiquity of funnels on energy landscapes. However, the scale-free degree distribution shows some differences from that of a model network grown using the obtained preferential attachment rules, implying that other factors are also important in the growth process.Comment: 8 pages, 8 figure

Basic mechanisms of MCD in animal models.

International audienceEpilepsy-associated glioneuronal malformations (malformations of cortical development [MCD]) include focal cortical dysplasias (FCD) and highly differentiated glioneuronal tumors, most frequently gangliogliomas. The neuropathological findings are variable but suggest aberrant proliferation, migration, and differentiation of neural precursor cells as essential pathogenetic elements. Recent advances in animal models for MCDs allow new insights in the molecular pathogenesis of these epilepsy-associated lesions. Novel approaches, presented here, comprise RNA interference strategies to generate and study experimental models of subcortical band heterotopia and study functional aspects of aberrantly shaped and positioned neurons. Exciting analyses address impaired NMDA receptor expression in FCD animal models compared to human FCDs and excitatory imbalances in MCD animal models such as lissencephaly gene ablated mice as well as in utero irradiated rats. An improved understanding of relevant pathomechanisms will advance the development of targeted treatment strategies for epilepsy-associated malformations