Dynamic Force Spectroscopy on Supported Lipid Bilayers: Effect ofTemperature and Sample Preparation

Biological membranes are constantly exposed to forces. The stress-strain relation in membranes determines thebehavior of many integral membrane proteins or other membrane related-proteins that show a mechanosensitive behavior. Here, we studied by force spectroscopy the behavior of supported lipid bilayers (SLBs) subjected to forces perpendicular to their plane. We measured the lipid bilayer mechanical properties and the force required for the punch-through event characteristic of atomic force spectroscopy on SLBs as a function of the interleaflet coupling. We found that for an uncoupled bilayer, the overall tip penetration occurs sequentially through the two leaflets, giving rise to two penetration events. In the case of a bilayer with coupled leaflets, penetration of the atomic force microscope tip always occurred in a single step. Considering the dependence of the jump-through force value on the tip speed, we also studied the process in the context of dynamic force spectroscopy (DFS). We performed DFS experiments by changing the temperature and cantilever spring constant, and analyzed the resultsin the context of the developed theories for DFS. We found that experiments performed at different temperatures and withdifferent cantilever spring constants enabled a more effective comparison of experimental data with theory in comparisonwith previously published data

Sustained response to infliximab treatment in two cases of early rheumatoid arthritis that has been maintained after drug withdrawal

The authors report two cases of active seropositive rheumatoid arthritis who were treated in an early phase of the disease with infliximab plus methotrexate obtaining a clinical remission. The benefit was maintained after the discontinuation of the anti-TNF alpha inhibitor for adverse events, indicating that the early administration of the drug may be followed by a sustained remission

Exploring the boundaries in an interdisciplinary context through the Family Resemblance Approach: The Dialogue Between Physics and Mathematics

Among the relevant aspects of the family resemblance approach (FRA), our study focuses on the potential of the approach to elaborate on disciplinary identities in an interdisciplinary context, specifically regarding the interplay between physics and mathematics. We present and discuss how the FRA wheel can be used and intertwined with the framework of boundary objects and boundary crossing mechanisms (Akkerman & Bakker, Review of Educational Research, 81, 132–169, 2011), which is well-known in STEM education for dealing with interdisciplinarity. The role of the FRA discussed in the article is dual: both practical and theoretical. It is practical in that we show how its use, in combination with the Akkerman and Bakker framework, appears effective in fostering productive discussions among prospective teachers on disciplinary identities and interdisciplinarity in historical cases. It is theoretical in that the combination of the two frameworks provides the vocabulary to characterise the ‘ambiguous nature’ of interdisciplinarity: like boundaries, interdisciplinarity both separates disciplines, making their identities emerge, and connects them, fostering mechanisms of crossing and transgressing the boundaries. This empirical study reveals how the theoretical elaboration took advantage of the prospective teachers’ contributions. We initially presented the FRA to characterise disciplinary identities, but the prospective teachers highlighted its potential to characterise also the boundary zone and the dialogue between physics and mathematics. The data analysis showed that the combination of the two frameworks shaped a complex learning space where there was room for very different epistemic demands of the prospective teachers: from those who feel better within the identity cores of the disciplines, to those who like to inhabit the boundary zone and others who like to re-shape boundary spaces and move dynamically across them

The identity of Rana margaritifera Laurenti, 1768 (Anura, Bufonidae)

Rana margaritifera was described by Laurenti in 1768 and currently is associated to the genus Rhinella, under the combination Rhinella margaritifera. Currently, the R. margaritifera species group consists of 16 recognized species. Furthermore, many additional species have been suggested to exist in this group which highlights the ambiguity surrounding the identity of Rhinella margaritifera and impend further description of the species in this group. After an exhaustive bibliographic review, we concluded that the recent designation of a lectotype for R. margaritifera is invalid according with Art. 73, ICZN, 1999. Herein, we designate and provide the description of a neotype for Rana margaritifera Laurenti, 1768.Fil: Lavilla, Esteban Orlando. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; ArgentinaFil: Caramaschi, Ulisses. Universidade Federal do Rio de Janeiro; BrasilFil: Langone, Jose A.. Museo Nacional de Historia Natural. Departamento de Herpetología; UruguayFil: Pombal, Jose P.. Universidade Federal do Rio de Janeiro; BrasilFil: de Sá, Rafael O.. University of Richmond. Department of Biology; Estados Unido

The Identity of \u3cem\u3eRana margaritifera\u3c/em\u3e Laurenti, 1768 (Anura, Bufonidae)

Rana margaritifera was described by Laurenti in 1768 and currently is associated to the genus Rhinella, under the combination Rhinella margaritifera. Currently, the R. margaritifera species group consists of 16 recognized species. Further-more, many additional species have been suggested to exist in this group which highlights the ambiguity surrounding the identity of Rhinella margaritifera and impend further description of the species in this group. After an exhaustive bibliographic review, we concluded that the recent designation of a lectotype for R. margaritifera is invalid according with Art. 73, ICZN, 1999. Herein, we designate and provide the description of a neotype for Rana margaritifera Laurenti, 1768

A neotype for Hyla x-signata Spix, 1824 (Amphibia, Anura, Hylidae)

The uncertain identity of Hyla x-signata Spix, 1824 has been a pervasive problem in the taxonomy of the genus Scinax. A species supposedly distributed from northeastern Brazil northwards to Colombia and Venezuela, described in a few lines without much information and with an accompanying figure, and its type specimen lost during World War II, combined to produce a curious situation. Twenty-one of the 39 species of the S. ruber Clade described in the last 50 years were considered to require a diagnosis from S. x-signatus by their authors. In most cases these had no other alternative than to gather information about this species from indirect sources, frequently pointing out the problems associated with its uncertain identity. In this paper, we review the taxonomic history of Hyla x-signata, designate a neotype, provide a redescription including advertisement call and sequence data, and diagnose it from all other species of the S. ruber Clade.Fil: de Araujo Vieira, Katyuscia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pombal, José P.. Universidade Federal Do Rio de Janeiro. Museu Nacional; BrasilFil: Caramaschi, Ulisses. Universidade Federal Do Rio de Janeiro. Museu Nacional; BrasilFil: Novaes-e-Fagundes, Gabriel. Universidade Estadual de Santa Cruz; BrasilFil: Orrico, Victor G. D.. Universidade Estadual de Santa Cruz; BrasilFil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Poorly differentiated clusters (PDC) in colorectal cancer: Does their localization in tumor matter?

Poorly differentiated clusters (PDC) are aggregates of at least five neoplastic cells lacking evidence of glandular differentiation. By definition, they can be present at the invasive front (peripheral PDC or pPDC) and within the tumor stroma (central PDC or cPDC). In colorectal cancer (CRC), PDC are considered adverse prognosticators and seem to reflect epithelial mesenchymal transition (EMT). In this study, we have investigated the immuno-expression of two EMT-related proteins, E-cadherin and β-catenin, in PDC of primary CRCs and matched liver metastases. pPDC always showed nuclear β-catenin staining and diffusely reduced/absence of E-cadherin expression as opposed cPDC which showed nuclear β-catenin immunoreactivity and E-cadherin expression in about 50% of cases. In addition, the pattern of β-catenin and E-cadherin expression differed between PDC and the main tumor, and between primary CRC and liver metastasis (LM), in a percentage of cases. A discordant pattern of β-catenin and E-cadherin expression between pPDC and cPDC, between main tumor and cPDC, and between primary CRC and LM, confirms that EMT is a dynamic and reversible process in CRC. On the overall, this suggests that pPDC and cPDC are biologically different. We may advocate that PDC develop at the tumor center (cPDC) and then some of them migrate towards the tumor periphery while progressively completing EMT process (pPDC). Based on these results, PDC presence and counting may have different prognostic relevance if the assessment is done at the invasive front of the tumor or in the intratumor stroma

Epidemiology of Strongyloides stercoralis in northern Italy: Results of a multicentre case-control study, February 2013 to July 2014

Strongyloides stercoralis is a soil-transmitted helminth widely diffused in tropical and subtropical regions of the world. Autochthonous cases have been also diagnosed sporadically in areas of temperate climate. We aimed at defining the epidemiology of strongyloidiasis in immigrants and Italians living in three northern Italian Regions. Screening for S. stercoralis infection was done with serology, confirmation tests were a second serological method or stool agar culture. A case-control approach was adopted and patients with a peripheral eosinophil count 65 500/mcL were classified as cases. Of 2,701 individuals enrolled here 1,351 were cases and 1,350 controls; 86% were Italians, 48% women. Italians testing positive were in 8% (97/1,137) cases and 1% (13/1,178) controls (adjusted odds ratio (aOR) 8.2; 95% confidence interval (CI): 4.5-14.8), while positive immigrants were in 17% (36/214) cases and in 2% (3/172) controls (aOR 9.6; 95% CI: 2.9-32.4). Factors associated with a higher risk of infection for all study participants were eosinophilia (p < 0.001) and immigration (p = 0.001). Overall, strongyloidiasis was nine-times more frequent in individuals with eosinophilia than in those with normal eosinophil count