bluuebunny/crossref_metadata_2025 huggingface dataset:
A STUDY ON THE IMPACT OF TEETH MESHING CONDITIONS AND PROFILE CORRECTION ON THE CARRYING CAPACITY, WEAR, AND LIFE OF A CYLINDRICAL GEAR
Authors: CHERNETS Myron , KIEŁBIŃSKI Jerzy , CHERNETS Jurij
Published: November 2018

Using an innovative method for determining wear and life of toothed gears, the author investigates the effect of teeth meshing in a mixed (double-singledouble) tooth engagement of cylindrical helical gears on their contact strength, wear, and service life. The paper also presents a method for determining zones of double and single tooth engagement. It is found that gear profile correction leads to a reduction in maximum contact pressures by about 15–20%, depending on the applied type of correction. The distribution of pressures greatly depends on the conditions of tooth engagement. The wear of teeth is also significantly affected by their meshing conditions. Depending on the type of correction applied and its coefficients, the allowable limit of gear tooth wear will occur at different points of contact: at the beginning of double tooth engagement and at the beginning or end of single-tooth engagement. It is shown that the service life of gears can be considerably prolonged if optimum correction coefficients are applied. Specifically, height correction increases the gear life by 1.66 times while angular correction prolongs the service life of gears by up to two times.
JOINT CARTILAGE LUBRICATION WITH PHOSPHOLIPID BILAYER
Authors: WIERZCHOLSKI Krzysztof
Published: November 2018

The surface of an articular cartilage human joint, coated with phospholipid bilayers or multi-layers, plays an important role in the surface-active phospholipid lubrication, friction, and wear during human limb movement. The biological bi-layer is a thin polar membrane composed of two layers of phospholipids that have a hydrophilic phosphate head (from the outside) and a hydrophobic tail (from the inside) consisting of two fatty acid chains. These membranes are flat sheets that form a continuous barrier around all cells. Synovial fluid (SF) in the human joint gap contains glycoprotein, lubricin (proteinglycan 4), and hyaluronidase, i.e. an enzyme that produces hialuron acid and ±10% phospholipids. Because the mechanism of surface articular phospholipid lubrication (SAPL) has been a frequently controversial subject in the past decade, this fact requires showing the hydrodynamic description in the form of a mathematical model of the abovementioned problem and its particular solution. To give a description of this model, it is necessary to recognize the variations of the dynamic viscosity of synovial fluid as a function of parameters depending on the presence of many phospholipid particles. To these parameters belong power (exponent) concentration of hydrogen ions (pH), cartilage wet ability (We), collagen fibre concentration in synovial fluid, and a created electrostatic field on the phospholipid membrane. Based on the Young-Laplace-Kelvin Law, initial achievements presented in scientific papers and our own investigations illustrated in this paper, the decrements, and increments of synovial fluid dynamic viscosities versus pH and wet ability (We) increases, simultaneously taking into account the influence of the intensity of charges in the electrostatic field. Moreover, this study considers the influence of collagen fibre concentration on the dynamic viscosity of synovial fluid. Based on initial considerations performed by virtue of the developed SAPL, it may be stated that the charge increments from low to high values of the electrostatic field is connected with viscosity increases of synovial fluid but only simultaneously with the pH index and cartilage wet ability variations.
THE INFLUENCE OF THE MOTION PARAMETERS ON THE SURFACE LAYER OF METAL-POLYMER SLIDING PAIRS AT LOW TEMPERATURES
Authors: PTAK Anita
Published: November 2018

The surface layer of the polymeric sliding materials co-operating with steel has an impact on the tribological properties at low temperatures. The goal of the present study was to determine the impact of the friction process parameters on the change in the surface layer of the polymeric materials. Three polymeric materials, namely PA6, PEEK, and PTFE, were tested. The materials were used for the sliding pairs with the typical construction steel C-45. At first, the tribological investigation at a low temperature T = (–50–0)°C was performed. Before and after that, the friction surface of the polymers, including the surface roughness and microhardness, were evaluated. During the experiment, variable parameters were the sliding velocity (v = 0.5 – 2 [m/s]) and the unit pressure (p = 0.5 – 3 [MPa]). The research has shown changes in the surface layer after the tribological tests at low temperatures. Strengthening and smoothing of the friction surface were observed, depending on the assumed process parameters.
A GENERALIZED METHOD FOR PREDICTING CONTACT STRENGTH, WEAR, AND THE LIFE OF INVOLUTE CONICAL SPUR AND HELICAL GEARS: PART 1. SPUR GEARS
Authors: CHERNETS Myron
Published: November 2018

The paper presents the results of research undertaken to determine maximum contact pressures, wear, and the life of involute conical spur gear, taking into account gear height correction, tooth engagement, and weargenerated changes in the curvature of their involute profile. Moreover, we have established the following: (a) the initial contact pressures are higher in the internal section with double-single-double tooth engagement; (b) the highest values can be observed at the entry of single tooth engagement; (c) the maximal tooth wear of the wheels in the frontal section will be less than half of that in the internal section; (d) profile shift coefficients have an optimum at which the highest gear life is possible; and (e) gear life in the internal section will be less than half of that the frontal section. The calculations were made for a reduced cylindrical gear using a method developed by the authors. The effect of applied conditions of tooth engagement in the frontal and internal sections of a cylindrical gear ring is shown graphically. In addition, optimal correction coefficients ensuring the longest possible gear life are determined.
ANALYSIS OF THE POSSIBILITIES OF USING CRN+a-C:H:W COATINGS TO MITIGATE FRETTING WEAR IN PUSH FIT JOINTS OPERATING IN ROTATIONAL BENDING CONDITIONS
Authors: KOWALSKI Sławomir
Published: November 2018

In this article, the results of wear tests of a push fit joint operating in rotational bending conditions have been presented. The assumed operation conditions were similar to those for a real rail vehicle wheel set. Samples made of uncoated C45 steel and those in which shafts were covered with a CrN+a-C:H:W coating were analysed. The push fit joint was loaded with 550 N, and it completed 8x106 cycles. Following wear tests, the macroscopic and microscopic observations of the shaft top layer were conducted to determine the intensity of fretting wear development. The former demonstrated that, in the case of uncoated shafts, wear occurs on either side of the joint, in the form of a maximum 2 mm wide ring. The use of protective coatings significantly reduced damage to the shaft top layer. Traces of fretting wear occur occasionally at the shaft circumference and affect small areas. The microscopic observations and EDS analysis of the chemical composition of the areas affected by fretting demonstrated mainly wear in the form of the build-up of material originating from, first of all, the shearing of sleeve top layer micro-irregularities that underwent plastic deformation and then oxidation.
VIBRATION DIAGNOSTIC OF A FRICTION PROCESS IN SLIDE BEARINGS
Authors: LEPIARCZYK Dariusz , GAWĘDZKI Wacław
Published: November 2018

An analysis of the condition of technical objects is carried out by diagnostic systems, the purpose of which is to detect irregularities in their operation and to prevent damages. In slide bearings, it applies to the diagnostic of friction and thermal phenomena of mating friction pairs. Among many methods of bearing diagnostics, special attention should be paid to vibration diagnostic methods based on measurements of relative vibration parameters or on absolute vibration (displacement, velocity, or acceleration of vibration). Methods of the vibration diagnostic of bearings rely on periodic or continuous measurements of relative vibration parameters of the bearing housing in relation to the rotor (in the case of slide bearings the measurements of the bearing sleeve in relation to the shaft neck) or absolute vibration parameters of the bearing housing (i.e. the sleeve in the case of slide bearing). The article presents a method of vibration diagnostics of friction phenomena that occur during the operation of slide bearings under various lubrication and load conditions. There are presented methods of analysis and the interpretation of measurement data obtained as a result of the conducted slide bearing tests on the laboratory stand. A method for assessing a technical condition of the slide bearing friction pairs is proposed.
EXPERIMENTAL INVESTIGATION OF A FOIL BEARING STRUCTURE WITH A POLYMER COATING UNDER STATIC LOADS
Authors: ŻYWICA Grzegorz , BAGIŃSKI Paweł
Published: November 2018

Gas foil bearings can operate at very high temperatures and rotational speeds. The operation under such conditions requires developing an appropriate bearing design, including the use of advanced material solutions. This article presents one of the basic stages of work on a new foil bearing, namely, experimental research on the structural supporting layer of such a bearing regarding its static loads. Tests of the bearing were carried out on a test rig specially prepared for this purpose. Changing the magnitude and direction of the load was possible. The elasto-damping elements of the bearing were made of thin metal foils. In addition, a layer of carefully selected polymer was applied onto one side of the top foil in order to protect the surface and reduce friction. Characteristics of the structure of the foil bearing were determined at various load variants after taking a series of measurements upon it. The conducted research has yielded much information about static characteristics of the structural supporting layer of a new foil bearing in which the top foil’s surface is covered with a layer of polymer. These results can be used, among other things, to optimise the bearing design and to verify numerical models.
EFFECT OF LASER HARDENING OF STEEL ON THE WEAR PROCESS IN AN ABRASIVE SOIL MASS
Authors: NAPIÓRKOWSKI Jerzy , KONAT Łukasz , PIETRUSZEWSKA Marta
Published: November 2018

This paper presents the results of tests for the effects of laser hardening on the course and intensity of wear of 38GSA (38MnSi4) and Hardox 600 steels in an abrasive soil mass. The tests were carried out under laboratory conditions, using a “rotating bowl” type machine. Two types of soil, i.e. light and medium, were used as the abrasive mass. Based on the obtained test results, it was found that hardness decreased (in relation to asdelivered condition). The performed laser surface hardening process significantly increased the abrasive wear resistance only for 38GSA (38MnSi4) steel. As regards to Hardox steel, the hardening treatment reduced the abrasive wear resistance index compared to the as-delivered condition of the steel.
TRIBOLOGICAL TESTS AND IMPACT TESTS OF ACRYLIC POLYMERS FOR DENTAL PROSTHETICS
Authors: RYNIEWICZ Anna M. , RYNIEWICZ Wojciech , BOJKO Łukasz , PAŁKA Paweł
Published: November 2018

The clinical functionality of the prosthesis structure consists of creating the most convenient conditions without any traumatic effects of chewing forces on the substrate and adapting it to the individual biomechanical exclusions of the stomatognathic system (SS). When transferring functional loads, the optimization of tribological features and the ability to absorb energy is an important design and material parameter. The aim is to evaluate acrylic plastics intended for prostheses in terms of resistance to wear and resistance to movement in sliding contact within the environment of artificial saliva and their ability to absorb energy. Based on the analysis of the test results, it can be pointed out that Vertex is a good material for partial and complete dentures. Villacryl demonstrated similar properties, with Probase and Probase O being slightly worse. The appropriate mechanical parameters of the materials used in the prosthesis allow the production of thin plates that accurately reproduce the prosthetic substrate and improve the patient’s comfort of use through such a fit.
THE EFFECT OF THE SHAPE OF OIL POCKETS ON THE FRICTION FORCE
Authors: WOŚ Sławomir , KOSZELA Waldemar , PAWLUS Paweł
Published: November 2018

Tests were carried out using a pin-on-disc tester under starved lubrication conditions. To achieve a conformal contact, a special construction was used with an adjustable counter sample. Textured surfaces with two dimple patterns (spiral an radial) and four shapes (circle, oval, triangle, and chevron) were tested. The contact area was lubricated with L-AN-46 oil. Before the tests, surface topographies of the discs were measured by a white light interferometer Talysurf CCI Lite. Tests showed that, in starved lubrication conditions, oil pocket shape and pattern affected the friction force.
Szwecja i problemy spójności współpracy państw w Europie Bałtyckiej w 2018 roku
Authors: Kubka Andrzej
Published: November 2018

Abstract Holding the presidency in crucial regional organizations and formats in Baltic Europe in 2018 (Nordic Council of Ministers, Council of the Baltic Sea States, Barents Euro-Arctic Council, formats N5 and NB8) Sweden is in exceptional position to enhance this region’s coherence. The goal of the analysis in the article is to explain in what way Sweden aims to coordinate the regional policy agenda. Official programmatic documents give the ground to assume that Sweden is seeking to achieve a regional coordinator’s role and is actively realizing planes which promote regional coherence in Baltic Europe. At the same time Sweden takes into consideration the European and global contexts of the policies in this region. The main overarching field of engagement in this respect becomes the realization of the UN Agenda 2030. The characteristics, i.e. scope and elaboration, of the political programmes of the Swedish presidency in the mentioned above organizations and formats suggests that Nordic as well as Nordic-Baltic cooperation are considered as the most important ones.
O PIBID NA PERSPECTIVA DA GESTÃO ESCOLAR
Authors: Leandro Lopes da Rosa Cristian , Eliza Rosa Gama Maria
Published: November 2018

In this research searched identify the understanding from teacher manager of the state public network of Basic Education from Santa Maria/RS about the Institutional Program of Scholarship for Initiation Teaching (PIBID). To achieve the proposed objectives a survey was conducted with a qualitative approach. The instrument used it was a questionnaire with open questions answered by a school management teacher who since 2016, holds the position of management.The results indicate the absence of school the discussions and guidelines of the decisions involving the actions developed daily by PIBID. It is appropriate evidence that school management does not recognize its social function training for teachers.
Data Set for the Reporting of Oral Cavity Carcinomas: Explanations and Recommendations of the Guidelines From the International Collaboration of Cancer Reporting
Authors: Müller Susan , Boy Sonja C. , Day Terrence A. , Magliocca Kelly R. , Richardson Mary S. , Sloan Philip , Tilakaratne Wanninayake M. , Zain Rosnah B. , Thompson Lester D. R.
Published: November 2018

The International Collaboration on Cancer Reporting is a nonprofit organization whose goal is to develop evidence-based, internationally agreed-upon standardized data sets for each cancer site for use throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to the objective of improved patient management and enhanced epidemiologic research. Carcinomas of the oral cavity continue to represent a significant oncologic management burden, especially as changes in alcohol and tobacco use on a global scale contribute to tumor development. Separation of oral cavity carcinomas from oropharyngeal tumors is also important, as management and outcome are quite different when human papillomavirus association is taken into consideration. Topics such as tumor thickness versus depth of invasion, pattern of invasive front, extent and size of perineural invasion, and margin assessment all contribute to accurate classification and staging of tumors. This review focuses on the data set developed for Carcinomas of the Oral Cavity Histopathology Reporting Guide, with discussion of the key elements developed for inclusion.
Data Set for the Reporting of Carcinomas of the Major Salivary Glands: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting
Authors: Seethala Raja R. , Altemani Albina , Ferris Robert L. , Fonseca Isabel , Gnepp Douglas R. , Ha Patrick , Nagao Toshitaka , Skalova Alena , Stenman Göran , Thompson Lester D. R.
Published: November 2018

The International Collaboration on Cancer Reporting is a nonprofit organization whose goal is to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to achieving the objective of improved patient management and enhanced epidemiologic research. Salivary gland carcinomas are relatively uncommon, and as such, meaningful data about the many histologic types are not easily compared. Morphologic overlap between tumor types makes accurate classification challenging, but there are often significant differences in patient outcomes. Therefore, issues related to tumor type, tumor grading, high-grade transformation, extent of invasion, number and size of nerves affected, and types of ancillary studies are discussed in the context of daily application to specimens from these organs. This review focuses on the data set developed for salivary gland carcinomas with discussion of the key core and noncore elements developed for inclusion by an international expert panel of head and neck and oral-maxillofacial pathologists and surgeons.
Family acculturation in host and immigrant couples: Dyadic research in an Italian context
Authors: Rania Nadia , Migliorini Laura , Rebora Stefania
Published: November 2018

The purpose of this research is to study acculturation strategies and attitudes in central and peripheral domains of host and immigrant couples in an Italian context. The participants were 60 dyads (30 host couples and 30 immigrant couples) who completed a questionnaire based on the Relative Acculturation Extended Model (RAEM). Based on the analysis, we found that the general acculturation attitude preferred by immigrant couples is integration, and Italian couples prefer that immigrants adopt it. Furthermore, Italian partners show moderate internal agreement, whereas immigrant couples show a high degree of agreement. In both groups, the level of agreement between dyadic members is only partially determined by their membership within a social group. The socio-cultural context has a significant role in the internal similarity of Italian couples. In contrast, there is dyadic agreement within immigrant couples.
Self-esteem, social comparison, and Facebook use
Authors: Bergagna Elisa , Tartaglia Stefano
Published: November 2018

Facebook use is very popular among young people, but many open issues remain regarding the individual traits that are antecedents of different behaviours enacted online. This study aimed to investigate whether the relationship between self-esteem and the amount of time on Facebook could be mediated by a tendency towards social comparison. Moreover, three different modalities of Facebook use were distinguished, i.e., social interaction, simulation, and search for relations. Because of gender differences in technology use and social comparison, the mediation models were tested separately for males and females. Data were collected by means of a self-report questionnaire with a sample of 250 undergraduate and graduate Italian students (mean age: 22.18 years). The relations were examined empirically by means of four structural equation models. The results revealed the role of orientation to social comparison in mediating the relations between low self-esteem and some indicators of Facebook use, i.e., daily hours on Facebook and the use of Facebook for simulation. For females, the use of Facebook for social interaction was directly influenced by high self-esteem and indirectly influenced by low self-esteem. Globally, the dimension of social comparison on Facebook emerged as more important for females than for males.
In defence of machine learning: Debunking the myths of artificial intelligence
Authors: de Saint Laurent Constance
Published: November 2018

There has been much hype, over the past few years, about the recent progress of artificial intelligence (AI), especially through machine learning. If one is to believe many of the headlines that have proliferated in the media, as well as in an increasing number of scientific publications, it would seem that AI is now capable of creating and learning in ways that are starting to resemble what humans can do. And so that we should start to hope – or fear – that the creation of fully cognisant machine might be something we will witness in our life time. However, much of these beliefs are based on deep misconceptions about what AI can do, and how. In this paper, I start with a brief introduction to the principles of AI, machine learning, and neural networks, primarily intended for psychologists and social scientists, who often have much to contribute to the debates surrounding AI but lack a clear understanding of what it can currently do and how it works. I then debunk four common myths associated with AI: 1) it can create, 2) it can learn, 3) it is neutral and objective, and 4) it can solve ethically and/or culturally sensitive problems. In a third and last section, I argue that these misconceptions represent four main dangers: 1) avoiding debate, 2) naturalising our biases, 3) deresponsibilising creators and users, and 4) missing out some of the potential uses of machine learning. I finally conclude on the potential benefits of using machine learning in research, and thus on the need to defend machine learning without romanticising what it can actually do.
O Que Foi Feito da Campanha “Quero Educação Musical na Escola”
Authors: Radicetti Felipe
Published: November 2018

Este artigo tem por objetivo comunicar aos interessados, os fatos precipitados a partir da Sanção Presidencial, em 18 de outubro de 2008, da Lei 11.769/2008, contextualizando-os no processo iniciado pela Campanha “Quero Educação Musical na Escola”. A situação em que a Lei se encontra, após a decorrência do prazo máximo previsto, permite entender que a omissão à letra da Lei que ora se verifica configura o seu não-cumprimento por todas as instancias institucionais responsáveis pelo Ensino Básico no país: O Ministério da Educação e as Secretarias Estaduais e Municipais de Educação. Diante desse quadro, a campanha “Quero Educação Musical na Escola”, que se insere como um movimento na história da Educação Musical no Brasil, precisará mobilizar-se mais uma vez.
Effect of Grit Chamber Configuration on Particle Removal: Using Response Surface Method
Authors: Esfahani Nikoo Roghani , Mobarekeh Mohsen Nourouzi , Hoodaji Mehran
Published: November 2018

In recent years ever-increasing industrial growth has resulted in a significant increase in the production of wastewater, this wastewater sometimes contains high levels of suspended solids. Therefore, the need to formulate an appropriate course of action for managing this wastewater has reached a critical level. In this study, the removal of suspended particles in wastewater that were a byproduct of an idustrial cut stone production process were investigated. For these purposes, a laboratory grit chamber was employed, and response surface methodology (RSM) was used to simulate the contributing parameters in the settling process. In order to study the performance of the grit chamber, factors such as flow rate, inlet location and mesh size, parameters of pH, COD, BOD, TSS and turbidity in influent and effluent were monitored. Results indicated that values of pH, COD and BOD in raw wastewater were within the standard range of discharging wastewater. The results indicated that the model with a high correlation of 0.95 was able to simulate the process. In addition, turbidity removal was found to be affected by three parameters among which mesh size and its interaction with the flow rate were the most influential ones.
La cognificació de l'art
Authors: Vilar Roca Gerard
Published: November 2018

The Cognification of Art
 
 
Resum: Amb el terme “cognificació”, un mot pres en préstec de l’argot de la Intel.ligència Artificial, designo alguns dels processos pels quals les obres d’art han anat convertint-se cada cop més en dispositius per a la generació de coneixement. En particular, d’una banda, es tracta en aquest article dels fenòmens d’artificació d’objectes reals, com és el cas de la caixa de sabates de Gabriel Orozco, fenòmens que es remunten als ready-mades de Duchamp i que es generalitzen en el darrer mig segle, i, de l’altra, el fenomen de les pràctiques d’investigació artística que s’han generalitzat en els darrers quinze anys, fenomen que alhora és d’artificació de la recerca. Aquests fenòmens de cognificació, que alhora són d’artificació estètica en sentit fort, plantegen el problema d’en què consisteix de fet la transformació de quelcom en un dispositiu cognitiu artístic. Per aclarir-ho es discuteixen algunes idees de Kant, de Danto i de Deleuze.
 
Paraules clau: cognificació, artificació, idea estètica, Orozco, Kant, Danto i Deleuze.
 
 
Abstract: With the term "cognification", a word borrowed from the jargon of Artificial Intelligence, I designate some of the processes by which works of art have increasingly become devices for the generation of knowledge. In particular, on the one hand, this article deals with the phenomena of artification of real objects such as the shoe box of Gabriel Orozco, phenomena that go back to Duchamp's ready-mades and which are widespread in the last half century, and, on the other hand, the practices of artistic research that have become widespread in the last fifteen years, a phenomenon that is at the same time an artification of research. These phenomena of cognification, which at the same time are examples of aesthetic artification in a strong sense, raise the problem of what the transformation of something into a cognitive artistic device really is. To clarify this, some ideas of Kant, Danto and Deleuze are discussed.
 
Keywords: cognification, artification, aesthetic idea, Orozco, Kant, Danto, Deleuze.
Reusing microarray clinical data from a complex disease with bioinformatics tool
Authors: Del Prete Eugenio , Facchiano Angelo , Liò Pietro
Published: November 2018

Clinical bioinformatics, translational bioinformatics and personalised medicine are connected by the common task of analysing and integrating clinical data and results, in order to find important biomarkers related to pathologies and facilitate their prediction, diagnosis and treatment. New technologies provides the possibility to have more and more clinical data available in online databases. This data can be reused for studying complex disease from novel point of views. This work show how it is possible considering online microarray data from coeliac disease and some of its comorbidities, combining both the data and the results. The main goal is the extraction of common evidences among the selected pathologies, from genes to different kinds of functional annotation, showing which biological processes are more involved in these autoimmune disorders and quantifying the similarity between coeliac disease and its comorbidities. The pipeline of the work is developed in R language, and it is semi-automated. Methodologically, the advantage of this work is the possibility of performing the entire analysis starting from a different pathology; clinically, scientists can have the possibility of using data already published to highlight old and new evidences, with the possibility of improve the knowledge on a complex disease according to the availability of new microarray data.
A novel enhancer near the Pitx1 gene influences development and evolution of pelvic appendages in vertebrates
Authors: Thompson Abbey C , Capellini Terence D , Guenther Catherine A , Chan Yingguang Frank , Infante Carlos R , Menke Douglas B , Kingsley David M
Published: November 2018

Vertebrate pelvic reduction is a classic example of repeated evolution. Recurrent loss of pelvic appendages in sticklebacks has previously been linked to natural mutations in a pelvic enhancer that maps upstream of Pitx1. The sequence of this upstream PelA enhancer is not conserved to mammals, so we have surveyed a large region surrounding the mouse Pitx1 gene for other possible hind limb control sequences. Here we identify a new pelvic enhancer, PelB, that maps downstream rather than upstream of Pitx1. PelB drives expression in the posterior portion of the developing hind limb, and deleting the sequence from mice alters the size of several hind limb structures. PelB sequences are broadly conserved from fish to mammals. A wild stickleback population lacking the pelvis has an insertion/deletion mutation that disrupts the structure and function of PelB, suggesting that changes in this ancient enhancer contribute to evolutionary modification of pelvic appendages in nature.
Revealing the secrets of secretion
Authors: Galione Antony , Davis Lianne C
Published: November 2018

An intracellular ion channel may have a central role in the release of cytokines by macrophages.
Assessing distinct patterns of cognitive aging using tissue-specific brain age prediction based on diffusion tensor imaging and brain morphometry
Authors: Richard Geneviève , Kolskår Knut , Sanders Anne-Marthe , Kaufmann Tobias , Petersen Anders , Doan Nhat Trung , Monereo Sánchez Jennifer , Alnæs Dag , Ulrichsen Kristine M. , Dørum Erlend S. , Andreassen Ole A. , Nordvik Jan Egil , Westlye Lars T.
Published: November 2018

Multimodal imaging enables sensitive measures of the architecture and integrity of the human brain, but the high-dimensional nature of advanced brain imaging features poses inherent challenges for the analyses and interpretations. Multivariate age prediction reduces the dimensionality to one biologically informative summary measure with potential for assessing deviations from normal lifespan trajectories. A number of studies documented remarkably accurate age prediction, but the differential age trajectories and the cognitive sensitivity of distinct brain tissue classes have yet to be adequately characterized. Exploring differential brain age models driven by tissue-specific classifiers provides a hitherto unexplored opportunity to disentangle independent sources of heterogeneity in brain biology. We trained machine-learning models to estimate brain age using various combinations of FreeSurfer based morphometry and diffusion tensor imaging based indices of white matter microstructure in 612 healthy controls aged 18–87 years. To compare the tissue-specific brain ages and their cognitive sensitivity, we applied each of the 11 models in an independent and cognitively well-characterized sample (n = 265, 20–88 years). Correlations between true and estimated age and mean absolute error (MAE) in our test sample were highest for the most comprehensive brain morphometry (r = 0.83, CI:0.78–0.86, MAE = 6.76 years) and white matter microstructure (r = 0.79, CI:0.74–0.83, MAE = 7.28 years) models, confirming sensitivity and generalizability. The deviance from the chronological age were sensitive to performance on several cognitive tests for various models, including spatial Stroop and symbol coding, indicating poorer performance in individuals with an over-estimated age. Tissue-specific brain age models provide sensitive measures of brain integrity, with implications for the study of a range of brain disorders.
Genetic assessment of a bighorn sheep population expansion in the Silver Bell Mountains, Arizona
Authors: Erwin John A. , Vargas Karla , Blais Brian R. , Bennett Kendell , Muldoon Julia , Findysz Sarah , Christie Courtney , Heffelfinger James R. , Culver Melanie
Published: November 2018

Background

The isolated population of desert bighorn sheep in the Silver Bell Mountains of southern Arizona underwent an unprecedented expansion in merely four years. We hypothesized that immigration from neighboring bighorn sheep populations could have caused the increase in numbers as detected by Arizona Game and Fish Department annual aerial counts.

Methods

We applied a multilocus genetic approach using mitochondrial DNA and nuclear microsatellite markers for genetic analyses to find evidence of immigration. We sampled the Silver Bell Mountains bighorn sheep before (2003) and during (2015) the population expansion, and a small number of available samples from the Gila Mountains (southwestern Arizona) and the Morenci Mine (Rocky Mountain bighorn) in an attempt to identify the source of putative immigrants and, more importantly, to serve as comparisons for genetic diversity metrics.

Results

We did not find evidence of substantial gene flow into the Silver Bell Mountains population. We did not detect any new mitochondrial haplotypes in the 2015 bighorn sheep samples. The microsatellite analyses detected only one new allele, in one individual from the 2015 population that was not detected in the 2003 samples. Overall, the genetic diversity of the Silver Bell Mountains population was lower than that seen in either the Gila population or the Morenci Mine population.

Discussion

Even though the results of this study did not help elucidate the precise reason for the recent population expansion, continued monitoring and genetic sampling could provide more clarity on the genetic demographics of this population.
EXPERIMENTO INVESTIGATIVO A PARTIR DOS SABERES POPULARES EM UM ENFOQUE CTS: UMA PROPOSTA A PARTIR DO PROJETO DE EXTENSÃO PARA A FORMAÇÃO DE PROFESSORES DE QUÍMICA
Authors: Martini Viviane Paula , Monteiro Castilho Foggiatto Silveira Rosemari
Published: November 2018

O presente artigo apresenta uma proposta formativa de Alfabetização Científica e Tecnológica (ACT) a professores de química envolvendo um experimento investigativo de enfoque Ciência, Tecnologia e Sociedade (CTS), abordando: a importância de se utilizar esse enfoque no Ensino de Química, a compreensão a respeito da suposta neutralidade da ciência e o papel da experimentação. A proposta articula práticas educativas que integram: experimento e conteúdo, espaço e tempo de atividade experimental, saberes populares e saberes formais ensinados na escola, aproximando os alunos de seu contexto social, ampliando a compreensão de laboratório. O trabalho está alicerçado em ideias de cidadania, na busca pela formação integral de educandos, a partir da formação de valores éticos e morais, que contribuem para a melhoria social e ambiental da comunidade em que estão inseridos.
SOFTWARE GEOGEBRA PROPORCIONANDO O ENSINO DE FUNÇÕES TRIGONOMÉTRICAS NO ENSINO SUPERIOR
Authors: Cruz Romildo Pereira Da , Quartieri Marli Teresinha , De Mamam Andréia Spessatto
Published: November 2018

O relato descrito neste artigo remete-se a uma prática da disciplina de Estágio de Docência no Ensino Superior, na qual se desenvolveu um estudo de natureza qualitativa com 34 alunos dos cursos de Engenharia de Universidade do Interior do Rio Grande do Sul na disciplina de Introdução às Ciências Exatas. A proposta tendeu ao desenvolvimento de funções trigonométricas por meio de atividades e resolução de problemas que envolveram construção de gráficos usando o software GeoGebra, bem como papel e lápis. O instrumento da observação sistemática serviu de base para as nossas interpretações. Os resultados obtidos foram indicativos para concluir que o uso dessa estratégia contribui para a organização do ensino de funções trigonométricas; no entanto, é necessário possibilitar o acesso dos alunos às ferramentas necessárias. Constatou-se que a participação em tarefas que envolvem o uso de tecnologia e manipulação de materiais potencializa o aprendizado das funções...
A FÍSICA APLICADA AO CORPO HUMANO: UMA INTERVENÇÃO INTERDISCIPLINAR NO ENSINO MÉDIO
Authors: Sousa Fernanda Luíza de , Gonçalves Gislayne Elisana , Elias Josiane Maximina , Pinto Elisângela Silva
Published: November 2018

O presente trabalho relata uma intervenção didática utilizando a relação entre a Física e o corpo humano por meio de aulas práticas, vídeos e demonstrações. Para tanto, utilizou-se materiais de baixo custo e/ou reciclados. Abordou-se temas como a biomecânica e a óptica da visão. O objetivo central foi trabalhar de forma interdisciplinar conteúdos de áreas aparentemente distintas, a fim de tornar o ensino-aprendizado mais significativo, contextualizado e se fundamentando pedagogicamente na teoria sociocultural de Vygotsky. Esta intervenção didática foi aplicada em uma turma de 2º ano do ensino médio, de uma escola estadual, da cidade de Ouro Preto/MG. Foi possível notar que, por meio da metodologia de projetos, a qual possibilita a prática interdisciplinar, houve uma maior interação e participação dos alunos.
СИНТЕЗ БЕНЗИЛАЛКИЛОВЫХ ЭФИРОВ МЕЖМОЛЕКУЛЯРНОЙ ДЕГИДРАТАЦИЕЙ БЕНЗИЛОВОГО СПИРТА С АЛИФАТИЧЕСКИМИ СПИРТАМИ ПОД ДЕЙСТВИЕМ МЕДЬСОДЕРЖАЩИХ КАТАЛИЗАТОРОВ, "Журнал органической химии"
Authors: Байгузина А.Р. , Гималетдинова Л.И. , Хуснутдинов Р.И.
Published: November 2018

Осуществлен синтез бензилалкиловых эфиров с высокими выходами межмолекулярной дегидратацией бензилового и первичных, вторичных, третичных спиртов под действием медьсодержащих катализаторов. Образование бензилалкиловых эфиров проходит с участием бензильного катиона.
ИССЛЕДОВАНИЕ СВЯЗИ СОЛЕНОСТИ И ФЛУОРЕСЦЕНЦИИ ЖЕЛТОГО ВЕЩЕСТВА В КАРСКОМ МОРЕ, "Фундаментальная и прикладная гидрофизика"
Authors: Глуховец Д. И. , Гольдин Ю.А.
Published: November 2018

Представлены результаты исследований корреляционной связи интенсивности флуоресценции растворенного органического вещества и солености в поверхностном слое вод Карского моря. Исследования выполнены с использованием данных, полученных с помощью проточного измерительного комплекса в рейсах НИС «Профессор Штокман» и НИС «Академик Мстислав Келдыш» (2013-2015 гг.). Для исследования пространственной изменчивости связи флуоресценции окрашенной части растворенного органического вещества и солености используется предложенный авторами метод «скользящих корреляций». В области вод, подверженных воздействию речного стока зафиксирована сильная антикорреляция. В области преобладающего воздействия стока талых ледниковых вод зафиксирована положительная корреляция. В областях сопоставимого влияния указанных факторов, а также вне зоны опреснения связи не наблюдается. Зарегистрирована межгодовая изменчивость исследуемой связи. Границы области, подверженной влиянию речного стока, определяются по спутниковым данным сканера цвета MODIS, обработанным с использованием регионального алгоритма для Карского моря. Сильная антикорреляция в этой области, наблюдаемая в широком диапазоне изменения солености, позволяет использовать спутниковые карты пространственного распределения показателя поглощения желтого вещества для определения положения границ области поверхностного опресненного слоя, исследования его структуры и динамики
ДОЛГОВРЕМЕННАЯ ИЗМЕНЧИВОСТЬ ПРОЗРАЧНОСТИ ПОВЕРХНОСТНЫХ ВОД ЧЕРНОГО МОРЯ, "Фундаментальная и прикладная гидрофизика"
Authors: Ли М. Е. , Латушкин А. А. , Мартынов О. В.
Published: November 2018

Проведен анализ изменений прозрачности поверхностных вод Черного моря по данным определений глубины видимости белого диска. Использованы как литературные данные, так и результаты собственных экспедиционных определений на научно-исследовательских судах и стационарной океанографической платформе. Показано, что после катастрофического снижения прозрачности вод поверхностного слоя, отмечавшегося в начале 1990-х гг., произошло постепенное повышение ее значений до величин, наблюдавшихся в 1960-1980 гг. Снижение прозрачности объясняется перестройкой структуры планктонного сообщества вод Черного моря под воздействием поступления с речным стоком больших количеств биогенных веществ антропогенного происхождения и появлением вселенца - гребневикаMnemiopsis. Улучшению ситуации способствовало снижение хозяйственной активности прибрежных стран в связи кризисными явлениями в их экономике, а также появлением второго вселенца - гребневика Beroe ovata, который уменьшил воздействие гребневика Mnemiopsis на планктонное сообщество. Отмечается, что полного восстановления экосистемы моря не произошло, и следствием этого являются рецидивы аномального развития фитопланктона. Однако продолжительность восстановления экосистемы после рецидивов в настоящее время составляет 3-4 месяца, в отличие от периода в несколько лет в начале 1990-х гг.
Interplay between small and long non‐coding RNAs in cutaneous melanoma: a complex jigsaw puzzle with missing pieces
Authors: Riefolo Mattia , Porcellini Elisa , Dika Emi , Broseghini Elisabetta , Ferracin Manuela
Published: November 2018

The incidence of cutaneous melanoma (CM) has increased in the past few decades. The biology of melanoma is characterized by a complex interaction between genetic, environmental and phenotypic factors. A greater understanding of the molecular mechanisms that promote melanoma cell growth and dissemination is crucial to improve diagnosis, prognostication, and treatment of CM. Both small and long non‐coding RNAs (lncRNAs) have been identified to play a role in melanoma biology; microRNA and lncRNA expression is altered in transformed melanocytes and this in turn has functional effects on cell proliferation, apoptosis, invasion, metastasis, and immune response. Moreover, specific dysregulated ncRNAs were shown to have a diagnostic or prognostic role in melanoma and to drive the establishment of drug resistance. Here, we review the current literature on small and lncRNAs with a role in melanoma, with the aim of putting into some order this complex jigsaw puzzle.
Targeting HER2 in patient‐derived xenograft ovarian cancer models sensitizes tumors to chemotherapy
Authors: Harris Faye R. , Zhang Piyan , Yang Lin , Hou Xiaonan , Leventakos Konstantinos , Weroha Saravut J. , Vasmatzis George , Kovtun Irina V.
Published: November 2018

Ovarian cancer is the most lethal gynecologic malignancy. About 75% of ovarian cancer patients relapse and/or develop chemo‐resistant disease after initial response to standard‐of‐care treatment with platinum‐based therapies. HER2 amplifications and overexpression in ovarian cancer are reported to vary, and responses to HER2 inhibitors have been poor. Next generation sequencing technologies in conjunction with testing using patient‐derived xenografts (PDX) allow validation of personalized treatments. Using a whole‐genome mate‐pair next generation sequencing (MPseq) protocol, we identified several high grade serous ovarian cancers (HGS‐OC) with DNA alterations in genes encoding members of the ERBB2 pathway. The efficiency of anti‐HER2 therapy was tested in three different PDX lines with the identified alterations and high levels of HER2 protein expression. Treatment responses to pertuzumab or pertuzumab/trastuzumab were compared in each PDX line WITH standard carboplatin and paclitaxel combination treatment. In all three PDX models, HER2‐targeted therapy resulted in significant inhibition of tumor growth compared with untreated controls. However, the responses in each case were inferior to those to chemotherapy, even for chemo‐resistant lines. When chemotherapy and HER2‐targeted therapy were administered together, a significant regression of tumor was observed after 6 weeks of treatment compared with chemotherapy alone. Post‐treatment analysis of these tissues revealed that inhibition of the ERBB2 pathway occurred at the level of phosphorylation and expression of downstream targets. In conclusion, while targeting of presumably activated ERBB2 pathway alone in HGS‐OC results in a modest treatment benefit, a combination therapy including both chemotherapy drugs and HER2 inhibitors provides a far better response. Further studies are needed to address development of recurrence and sensitivity of recurrent disease to HER2‐targeted therapy.
Protein‐Based Hydrogels that Actuate Self‐Folding Systems
Authors: Gomes Conor M. , Liu Chang , Paten Jeffrey A. , Felton Samuel M. , Deravi Leila F.
Published: November 2018

An approach to build a chemomechatronic system inspired by self‐folding robots is described. This system, which comprises a protein‐based hydrogel bound to a low‐profile laminate, responds to different aqueous environments by undergoing geometric transformations. This response is dependent on the thickness and stiffness of the templating hydrogel, which directly regulates the diffusion of water into and out of the platform to initiate its reversible shape changes. When modified to include more complex geometries, these controllable shape changes can also be used to selectively trigger multiple folding events, illustrating a new platform for chemically initiated mechatronic devices. Together, these data show how compositionally discrete components are physically, chemically, and mechanically coupled together to generate a new actuator for biohybrid self‐folding systems.
Molybdenum Oxide Nanosheets with Tunable Plasmonic Resonance: Aqueous Exfoliation Synthesis and Charge Storage Applications
Authors: Etman Ahmed S. , Wang Ligang , Edström Kristina , Nyholm Leif , Sun Junliang
Published: November 2018

Herein, a simple aqueous‐exfoliation strategy is introduced for the fabrication of a series of MoO3−x nanosheets (where x stands for oxygen vacancies) using two commercial molybdenum oxide precursors, MoO2 and MoO3. The nanosheets offer a localized surface plasmon resonance (LSPR) effect which is dependent on the structure and local environment of the nanosheets. The LSPR can be efficiently tuned by changing the weight ratio between the molybdenum oxide precursor(s) and/or by solar light irradiation using a low‐energy UV lamp (36 W). For the pristine MoO3−x nanosheets, the highest LSPR signal is obtained for nanosheets prepared using 80% MoO2. On the contrary, after solar light irradiation, the nanosheets prepared using pure MoO3 offer the highest LSPR response. The nanosheets also show an outstanding rate capability when used as binder‐free supercapacitor electrodes in an acidified Na2SO4 electrolyte. The electrodes exhibit discharge capacities of 110 and 75 C g−1 at a scan rate of 20 and 1000 mV s−1, respectively. The MoO3−x nanosheets can likewise be used as a negative electrode material for lithium‐ion batteries. The efficient eco‐friendly synthesis and the ability to tune the photochemical and electrochemical properties of the nanosheets make this approach interesting to many energy‐related research fields.