Complexity and anisotropy in host morphology make populations safer against epidemic outbreaks

One of the challenges in epidemiology is to account for the complex morphological structure of hosts such as plant roots, crop fields, farms, cells, animal habitats and social networks, when the transmission of infection occurs between contiguous hosts. Morphological complexity brings an inherent heterogeneity in populations and affects the dynamics of pathogen spread in such systems. We have analysed the influence of realistically complex host morphology on the threshold for invasion and epidemic outbreak in an SIR (susceptible-infected-recovered) epidemiological model. We show that disorder expressed in the host morphology and anisotropy reduces the probability of epidemic outbreak and thus makes the system more resistant to epidemic outbreaks. We obtain general analytical estimates for minimally safe bounds for an invasion threshold and then illustrate their validity by considering an example of host data for branching hosts (salamander retinal ganglion cells). Several spatial arrangements of hosts with different degrees of heterogeneity have been considered in order to analyse separately the role of shape complexity and anisotropy in the host population. The estimates for invasion threshold are linked to morphological characteristics of the hosts that can be used for determining the threshold for invasion in practical applications.Comment: 21 pages, 8 figure

Tourmaline Composition of the Kı¸sladag Porphyry Au Deposit,Western Turkey: Implication of Epithermal Overprint

The Kışladağ porphyry Au deposit occurs in a middle Miocene magmatic complex comprising three different intrusions and magmatic-hydrothermal brecciation related to the multiphase effects of the different intrusions. Tourmaline occurrences are common throughout the deposit, mostly as an outer alteration rim around the veins with lesser amounts disseminated in the intrusions, and are associated with every phase of mineralization. Tourmaline mineralization has developed as a tourmaline-rich matrix in brecciated zones and tourmaline-quartz and/or tourmaline-sulfide veinlets within the different intrusive rocks. Tourmaline was identified in the tourmaline-bearing breccia zone (TBZ) and intrusive rocks that had undergone potassic, phyllic, and advanced argillic alteration. The tourmaline is present as two morphological varieties, aggregates of fine crystals (rosettes, fan-shaped) and larger isolated crystals and their aggregates. Four tourmaline generations (tourmaline I to IV) have different compositions and substitutions. Tourmaline I in TBZ and INT#1 is distinguished by the highest Fetot and enriched in Fe3+. Tourmalines II and III occur as fine aggregates, accompanied by the formation of isolated crystals and are characterized by lower Fetot and Fe3+. Tourmaline IV is characterized by the lowest Fetot, enriched in Cl, and has the highest proportion of X-site vacancy among all the tourmalines. Tourmaline I may be attributed to the potassic stage in INT#1 and early tourmaline in TBZ. Tourmalines II and III from INT#1 and the TBZ could be referred to the phyllic stage. The low Fe content in tourmaline is caused by the simultaneous deposition of sulfide minerals. Tourmaline IV from the TBZ and tourmaline II from INT#3 are distinguished by the high X-site vacancy proportion up to the formation of X-site vacant species as well as enriched in Cl; they can be attributed to the argillic stage of the hydrothermal process. The textural and especially chemical data of the tourmaline from the Kışladağ Au deposit provide information on the physico-chemical conditions during the porphyry to epithermal transition and subsequent epithermal overprinting

Overexpression of ZEB2 in Peritumoral Liver Tissue Correlates with Favorable Survival after Curative Resection of Hepatocellular Carcinoma

BACKGROUND: ZEB2 has been suggested to mediate EMT and disease aggressiveness in several types of human cancers. However, the expression patterns of ZEB2 in hepatocellular carcinoma (HCC) and its effect on prognosis of HCC patients treated with hepatectomy are unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the methods of tissue microarray and immunohistochemistry (IHC) were utilized to investigate ZEB2 expression in HCC and peritumoral liver tissue (PLT). Receiver operating characteristic (ROC), spearman's rank correlation, Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the data. Up-regulated expression of cytoplasmic/nuclear ZEB2 protein was observed in the majority of PLTs, when compared to HCCs. Further analysis showed that overexpression of cytoplasmic ZEB2 in HCCs was inversely correlated with AFP level, tumor size and differentiation (P<0.05). Also, overexpression of cytoplasmic ZEB2 in PLTs correlated with lower AFP level (P<0.05). In univariate survival analysis, a significant association between overexpression of cytoplasmic ZEB2 by HCCs/PLTs and longer patients' survival was found (P<0.05). Importantly, cytoplasmic ZEB2 expression in PLTs was evaluated as an independent prognostic factor in multivariate analysis (P<0.05). Consequently, a new clinicopathologic prognostic model with cytoplasmic ZEB2 expression (including HCCs and PLTs) was constructed. The model could significantly stratify risk (low, intermediate and high) for overall survival (P = 0.002). CONCLUSIONS/SIGNIFICANCE: Our findings provide a basis for the concept that cytoplasmic ZEB2 expressed by PLTs can predict the postoperative survival of patients with HCC. The combined cytoplasmic ZEB2 prognostic model may become a useful tool for identifying patients with different clinical outcomes

The militarisation of English schools: Troops to Teaching and the implications for Initial Teacher Education and race equality

This article considers the implications of the Troops to Teaching (TtT) programme, to be introduced in England in autumn 2013, for Initial Teacher Education (ITE) and race equality. TtT will fast-track ex-armed service members to teach in schools, without necessarily the requirement of a university degree. Employing theories of white supremacy, and Althusser’s (1971) concept of Ideological and Repressive State Apparatus, I argue that this initiative both stems from, and contributes to, a system of social privilege and oppression in education. Despite appearing to be aimed at all young people, the planned TtT initiative is actually aimed at poor and racially subordinated youth. This is likely to further entrench polarisation in a system which already provides two tier educational provision: TtT will be a programme for the inner-city disadvantaged, whilst wealthier, whiter schools will mostly continue to get highly qualified teachers. Moreover, TtT contributes to a wider devaluing of current ITE; ITE itself is rendered virtually irrelevant, as it seems TtT teachers will not be subject specialists, rather will be expected to provide military-style discipline, the skills for which they will be expected to bring with them. More sinister, I argue that TtT is part of the wider militarisation of education. This military-industrial-education complex seeks to contain and police young people who are marginalised along lines of race and class, and contributes to a wider move to increase ideological support for foreign wars - both aims ultimately in the service of neoliberal objectives which will feed social inequalities

Influence of an abrupt increase in blood pressure on the blood-brain barrier permeability during acute hypertension and epileptic seizures

The interrelationship between the breakdown of the blood-brain barrier according to the Evans-blue passage and an abrupt increase in blood pressure (DeltaP) was studied in rats subjected to adrenaline-induced acute hypertension and also pentylenetetrazol-induced seizures. Arterial blood pressure was increased by adrenaline, then immediately i.v. nifedipine was injected and subsequently decreased to the control value in the acute hypertensive group. Arterial blood pressure was increased by pentylenetetrazol, then immediately GABA (gamma -aminobutiric acid) was injected and the blood pressure was decreased to the control value in the seizure group