Nitric oxide enhances de novo formation of endothelial gap junctions

Objective: Gap junctions (formed by connexins, Cx) are important for functional coordination of cells in the vascular wall. However, little is known about their physiological regulation in this tissue. We examined the effects of nitric oxide (NO), an important mediator of vasomotion, wound healing and angiogenesis, on the formation of gap junctions in endothelial cells (human umbilical vein endothelial cells, HUVEC). Methods: Flow cytometry was used to determine dye transfer through newly formed gap junctions between acutely coincubated HUVECs. Parallel experiments in wild-type HeLa cells (no connexins) and transfected HeLa cells exclusively expressing Cx43, Cx40 or Cx37 were performed to determine the specific role of Cx subtypes. The intracellular distribution of Cx40 was examined after fractionation with triton by Western blotting. Intracellular levels of cGMP and cAMP were measured by radioimmunoassay. Results: The NO donor SNAP (1 μM) enhanced gap-junctional coupling in HUVECs by about 40%. This was associated with an enhanced incorporation of Cx40 into the membrane. Both effects were restricted to Cx40 as analyzed in experiments with Cx-selective HeLa cells. The NO-induced increase in cell coupling was elicited by a corresponding rise of cGMP, which secondarily increased intracellular cAMP levels. The latter was an integral part of the signal cascade, since the protein kinase A (PKA) inhibitor H89 blocked the SNAP-induced incorporation of Cx40 into the plasma membrane. Conclusions: We conclude that NO is a potent modulator of gap-junctional coupling in endothelial cells. It enhances de novo formation of endothelial gap junctions by increasing incorporation of Cx40 into the plasma membrane due to PKA activation

Gap-junctional coupling between neutrophils and endothelial cells

Communication between leukocytes and endothelial cells is crucial for inflammatory reactions. Paracrine cross-talk and outside-in signaling (via adhesion molecules) have been characterized as communication pathways to date. As leukocytes and endothelial cells express connexins, we considered intercellular communication via gap junctions an intriguing additional concept. We found that gap-junctional coupling between neutrophils and endothelium occurred in a time-dependent, bidirectional manner and was facilitated by adhesion. After blockade of connexins, transmigration of neutrophils through the endothelial layer was enhanced, and the barrier function of cell monolayers was reduced during transmigration. Tumor necrosis factor α decreased coupling. In the presence of connexins, transmigration of neutrophils did not alter permeability. Thus, neutrophils couple to endothelium via gap junctions, functionally modulating transmigration and leakiness. Gapjunctional coupling may be a novel way of leukocyte- endothelial communication

Termodinàmica Social: La física com a justificació de l'Estatus Quo en l'Espanya de la restauració

Social Thermodynamics: Physics used to justify the status quo in Spain during the Restoration.Just as Darwinism was used to justify social policies like eugenics, at the end of the 19th century so it happened that social dynamics sought legitimacy for social hygiene programs or legislation concerning working hours, in the new Laws of Physics. At that time the worker was believed to be like a machine, whose work capacity could be measured scientifi cally, and science wasproffered as a solution to economic and social confl icts in the industrial era

Física y religión en la España decimonónica: más allá del mero conflicto

This article explores some interactions between the Spanish Catholic Church and physics in the Spain of the second half of the nineteenth century. It focuses in particular on the roll of the Church in the popularization of physic

Oliver Hochadel & Agustí Nieto-Galan, Barcelona: An Urban History of Science and Modernity, 1888-1929

Las dos ferias mundiales celebradas en Barcelona (1888 y 1929) que encapsulan el espacio temporal del volumen, la rápida industrialización y modernización sufrida por la ciudad durante este período, y la riqueza de los estudios de caso presentados, pueden hacer que los lectores se pregunten sobre los significados. con lo cual los editores se refieren a Barcelona como una segunda ciudad (en contraste con las metrópolis europeas). Además del hecho de que los estudios internacionales sobre historia urbana de la ciencia se han ocupado principalmente de capitales o grandes ciudades como Londres, París, Berlín o Chicago, las preguntas sobre si ciudades como Barcelona, Milán o Hamburgo (y la lista puede incluir muchas otras ciudades fuera de Europa y América del Norte) requieren un 'marco interpretativo diferente' y sobre cuáles son exactamente las 'características distintivas de la historia urbana [de la ciencia]' (p. 9) de estas ciudades, parecen requerir una mayor investigación comparativa y reflexion. Sin lugar a dudas, este volumen trae valiosas herramientas para tal esfuerzo académico. Al final, dos cuestiones son evidentes: las ricas y complejas culturas científicas de Barcelona alrededor de 1900, y la vibrante e innovadora comunidad de historiadores de la ciencia que trabajan y viven en la misma ciudad a principios del siglo XXI.The two world fairs held in Barcelona (1888 and 1929) that encapsulate the time space of the volume, the rapid industrialization and modernization suffered by the city during this period, and the richness of the case studies presented, may make readers wonder about the meanings with which the editors refer to Barcelona as a second city (in contrast to European metropolises). In addition to the fact that international scholarship on urban history of science have been mainly concerned with capitals or big cities such as London, Paris, Berlin, or Chicago, the questions about whether cities as Barcelona, Milan, or Hamburg (and the list may include many other cities outside Europe and North America) require a “different interpretative framework” and about what exactly are the “distinctive features of the urban history [of science]” (p. 9) of these cities, seem to required further comparative investigation and reflection. Undoubtedly, this volume brings valuable tools for such an academic endeavor. In the end two issues are evident: the rich and complex scientific cultures of Barcelona around 1900, and the vibrant and innovative community of science historians who work and live in the same city at the beginning of the 21th century

Styles of Knowledge Production in Colombia, 1850-1920

Argument Using the notion of styles of knowledge we refer to the ways diverse scientific communities claim to produce true knowledge, their understandings regarding the attitudes and values that scientists should have in order to grasp natural and social reality, and the practices and technologies developed within such styles. This paper analyzes scientific and medical enterprises that explored the relationship between environment, population, and society in Colombia between 1850 and 1920. We argue that similar styles of knowledge production were shared in human geography, medical geography, and climatic physiology at the mid-nineteenth century; and that some physicians working in bacteriology and physiology since the 1880s established epistemic boundaries between their work and earlier scientific activities, while others found these distinctions irrelevant. However, the historical actors committed to any of the styles of knowledge production explored in this article agreed on the local specificity of their objects of inquiry, therefore questioning European science. These styles of knowledge production also shaped different ways of perceiving and addressing national problems. Hence, this article is a contribution to the recent literature on both historical epistemology and social and cultural history of science and medicine. © Copyright Cambridge University Press 2016

Facial imitation improves emotion recognition in adults with different levels of sub-clinical autistic traits

We used computer-based automatic expression analysis to investigate the impact of imitation on facial emotion recognition with a baseline-intervention-retest design. The participants: 55 young adults with varying degrees of autistic traits, completed an emotion recognition task with images of faces displaying one of six basic emotional expressions. This task was then repeated with instructions to imitate the expressions. During the experiment, a camera captured the participants’ faces for an automatic evaluation of their imitation performance. The instruction to imitate enhanced imitation performance as well as emotion recognition. Of relevance, emotion recognition improvements in the imitation block were larger in people with higher levels of autistic traits, whereas imitation enhancements were independent of autistic traits. The finding that an imitation instruction improves emotion recognition, and that imitation is a positive within-participant predictor of recognition accuracy in the imitation block supports the idea of a link between motor expression and perception in the processing of emotions, which might be mediated by the mirror neuron system. However, because there was no evidence that people with higher autistic traits differ in their imitative behavior per se, their disproportional emotion recognition benefits could have arisen from indirect effects of imitation instructions

Luteal Presence and Ovarian Response at the Beginning of a Timed Artificial Insemination Protocol for Lactating Dairy Cows Affect Fertility: A Meta-Analysis

Progesterone (P4) concentration during follicular growth has a major impact on fertility response in timed artificial insemination (TAI) protocols. Luteal presence at the beginning of a TAI protocol and ovarian response after the first gonadotropin-releasing hormone (GnRH) injection (G1) affect P4 concentration and subsequently pregnancy per artificial insemination (P/AI). A systematic review of the literature and meta-analytical assessment was performed with the objective of evaluating the magnitude of the effect of luteal presence and ovarian response at the beginning of a TAI protocol on P/AI in lactating dairy cows. We considered only studies using synchronisation protocols consisting of GnRH and prostaglandin F (2 alpha). The time interval between G1 and prostaglandin F (2 alpha) (PGF (2 alpha)) had to range from 5 to 7 d. The time interval between the PGF (2 alpha) injection and G2 had to range from 48 to 72 h. We used 28 controlled experiments from 27 published manuscripts including 16,489 cows with the objective of evaluating the effect size of having a functional corpus luteum (CL) at G1 on P/AI. Information regarding ovulatory response after G1 was available for 5676 cows. In a subset of cows (n = 4291), information was available for luteal presence and ovulatory response at the initiation of the TAI protocol. A functional CL at G1 increased (p < 0.001) the relative risk of conceiving (RR (relative risk) = 1.32; 95% CI = 1.21-1.45) in lactating dairy cows. Ovulation after G1 increased (p < 0.001) the relative risk of conceiving (RR = 1.29; 95% CI = 1.20-1.38) in lactating dairy cows. The effect of ovulatory response on P/AI after G1 was affected by luteal presence at G1. In summary, there was a clear benefit on P/AI for cows starting a TAI protocol with a functional CL (+10.5 percentage units) and cows ovulating at the beginning of a TAI protocol (+11.0 percentage units)

Magnetic properties of single nanomagnets: EMCD on FePt nanoparticles

Energy-loss magnetic chiral dichroism (EMCD) allows for the quantification of magnetic properties of materials at the nanometer scale. It is shown that with the support of simulations that help to identify the optimal conditions for a successful experiment and upon implementing measurement routines that effectively reduce the noise floor, EMCD measurements can be pushed towards quantitative magnetic measurements even on individual nanoparticles. With this approach, the ratio of orbital to spin magnetic moments for the Fe atoms in a single L$1_0$ ordered FePt nanoparticle is determined to be ${m_l}/{m_s} = 0.08 \pm 0.02$. This finding is in good quantitative agreement with the results of XMCD ensemble measurements.Comment: 35 pages, 10 figure