bluuebunny/crossref_metadata_2025 huggingface dataset:
UMA PROPOSTA PARA A INTRODUÇÃO DO ENSINO DE FUNÇÕES ATRAVÉS DA UTILIZAÇÃO DO PROGRAMA TRACKER
Authors: Magarinus Renata , Buligon Lidiane , Martins Márcio Marques
Published: March 2017

http://dx.doi.org/10.5902/2179460X14847The present work aims to present a proposal for the introduction and exploration of the some concepts in the study of affine and quadratic functions. Furthermore, believing that contextualization of content and interdisciplinarity to corroborate the significant learning of mathematics, our work proposes a sequence of activities from, real problems will explore the some concepts in the study of affine and quadratic functions. To assist students in solving problems and exploring these concepts and use the software Tracker. We believe that this proposal will contribute to improving the quality of mathematics teaching and more specifically for teaching functions.
ATIVIDADES DE TRIGONOMETRIA PARA O ENSINO FUNDAMENTAL COM O USO DO SOFTWARE GEOGEBRA
Authors: Strasburg Ezequiel Bobsin , Sperotto Fabíola Aiub , Meneghetti Cinthya Maria Schneider
Published: March 2017

http://dx.doi.org/10.5902/2179460X16491This work aims to present new activities for teaching trigonometry in Elementary Education. The idea is to show how to teach the main trigonometric relations through exercises that guide students, gradually, to conclusions of these trigonometry relations. The suggested activities make use of “GeoGebra ”software, a feature that enables the construction of trigonometric circles that facilitate the understanding by students. This paper presents not only the sine relations, cosine and tangent for acute angles, as it is usually proposed by textbooks 9th year of elementary school, but also relationships with secant, cosecant and cotangent, and it is not limited to acute angles and the study of right triangles, this leaving, the student more prepared for the challenges of high school and to their professional life.
UM BREVE ESTUDO COMPARATIVO ENTRE AS ENERGIAS EÓLICA E NUCLEAR
Authors: Flores Tarcísio Santos
Published: March 2017

http://dx.doi.org/10.5902/2179460X18494It is apparent the human need to use electricity in the current globalized world. And along with the social and industrial and beyond the everyday comfort evolution came the abuse of power. Aware that Brazil is used as an energy source originating from hydroelectric and that it does not include all domestic demand, should be studied energy sources that can assist it. Two clean and cheap energy alternatives which can contribute to reducing the environmental impacts such as global warming and water shortages are wind and nuclear energy. Which again, exhibit ideal characteristics to serve as alternative sources for electricity production, mainly in the dry season.
AS INFLUÊNCIAS DAS TORRES HIPERBÓLICAS NAS USINAS TERMOELÉTRICAS: UM FOCO TERMONUCLEAR
Authors: Sapunaru Raquel Anna , Silva Olavo Cosme da , Lima Maria Thereza da Silva Lopes , Souza Marina Corrêa de , Flores Tarcísio Santos , Cruz Nathália Racielle da Silva , Diamantino Hugo Duarte , Barroso Lívia Alves , Rocha Bruna Almeida , Souza Rômulo Luiz Mendes , Ramos Pedro Camilo , Macedo Márcio Henrique Marques
Published: March 2017

http://dx.doi.org/10.5902/2179460X18495We present a brief analysis of the importance and efficiency of hyperbolic cooling towers for nuclear thermoelectric plants. with an emphasis on the thermonuclear plant processes.
OPTIMIZATION OF URBAN SPACES TO MUNICIPAL DEVELOPMENT (CASE BANDAR ABBAS)
Authors: Razaghpoor Hadi , Kamran Amin , Zarei Sana , Dirand Hamed , Kameli Mohsen
Published: March 2017

http://dx.doi.org/10.5902/2179460X19386Cities have grown haphazardly and urban areas have expanded to several times their primary size in a short while or have developed in separate sections without planning, tightly and randomly. This issue has come to be known as dispersion pattern or Sprawl and is a source of many problems in developing and developed cities. Bandar Abbas has also had a haphazard growth in the recent years. This paper attempts to investigate horizontal and vertical congestion in different parts of the city as a grid and then tries to draw on entropic indices with a cellular view to assess the order and balance of this grid city. Also, the results are used to compare the physical-operational concentration of the city between 2014 and 2006. In the end, a table is formulated according to the results presenting approaches, policies and projects for maintaining a balance between different parts of the city.
DESIGNING PREDICTIVE CONTROLLER BASED ON NONLINEAR MODEL FOR MULTI-STAGE MED DESALINATION SYSTEMS
Authors: Soleymanizadeh Ali , Shayanfar Heidar Ali
Published: March 2017

http://dx.doi.org/10.5902/2179460X19422Due to the use of fossil energy and environmentally pollutant fuels, groundwater and surface water pollution has led to a more progressive movement towards the technology of desalination systems in recent decades so that the issue of the desalination of seawaters and ocean waters has received great attention from most countries. In the meantime, the use of distillation desalination systems has been welcomed more than other systems because they take advantage of the sun's energy and do not negatively influence the environment. The PDE and nonlinear model of multi-effect desalination systems constitutes the structure under study in this paper. In order to control the variables of this model, a nonlinear predictive model controller (NPMC) has been proposed. The results obtained from the conduct of this controller on multi-effect desalination system in MATLAB Software is indicative of the acceptable performance of the controller.
RELATIONSHIP BETWEEN INVESTORS SENTIMENT INDEX WITH FIRST AND SECOND MARKET INDEXES IN TEHRAN STOCK EXCHANGE (TSE)
Authors: Fayyazi Hadi , Maharlouei Rasoul Goshtasbi
Published: March 2017

http://dx.doi.org/10.5902/2179460X19424The process of being affected of the investors in decision making from their sentiment has been considered in many recent researches in the field of the financial assets pricing. Some authors suggest that shifts in investor sentiment may in some instances better explain shortterm movement in asset prices than any other set of fundamental factors. The present study tries to investigate the relation between the investors sentiment index and First and Second Market Indexes in Tehran Stock Exchange Market. This paper, an index was used in order to measure the available data on sentiment of the investors in facing the risks in a 142-month period (2001 – 2014) in Tehran Stock Exchange. The used index can reveal and present the situation of the Iranian capital Market in terms of the Investors Sentiments. The results obtained from the present study reveal a positive and significant relation between the investors’ sentiment Index of the Tehran Exchange First and Second Market Indexes; and also by using from Granger Causality Test, it was revealed that there is a mutual causality relation between the investors’ sentiment Indexes of the TEFMIX and TESMIX.
EXPLORING TEACHERS’ REACTION TO THE IDENTITY CONSTRUCTION OF IRANIAN STUDENTS IN EFL CONTEXT
Authors: Ghaniabadi Saeed , Hashemi Hamid Reza
Published: March 2017

http://dx.doi.org/10.5902/2179460X19425The substantial achievements of the current research in the field of teaching English as a foreign language highlight the monumental influence of students’ identity construction on acquiring a foreign language. Due to the dearth of qualitative research that probe teachers’ awareness of the learners’ identity construction in classroom-oriented discourse and their reaction to it, the present study is to develop a systematic explanatory theory of those aspects of EFL learners’ identity disregarded by teachers in Iranian EFL context. This grounded theory research is founded upon the volunteer and theoretical sampling of 8 under-achieving learners from Azad university of Birjand, Iran. In-depth semi-structural interviews which took three weeks were employed by the researchers. The data collection and analysis procedure occurred between January and February, 2015. The iterative process of analysis yielded teachers’ failure to acknowledge the learners’ multiple identity as the core category that pulled together three other sub-categories including 1) the ignorance of imaginative identity of the students by teaches 2) teachers’ disregard of the multiple and dynamic identity of the learners in educational context 3) teachers’ lack of awareness from students contradictory identification with the culture of target language speakers. The results of this study are almost novel and of great significance for Iranian EFL teachers and other practitioners in this field.
WOMEN AND RURAL DEVELOPMENT IN IRAN: ANALYSIS OF THE EFFECT OF SOCIO- ECONOMIC CHANGES ON WOMEN’ WORK IN AGRICULTURE
Authors: Dadvar-Khani Fazileh , Choobchian Shahla
Published: March 2017

http://dx.doi.org/10.5902/2179460X19427There are a number of observable and marked changes in the economic, social, and also cultural status of women's life in rural areas. This study investigates factors which influence economic participation of women in north of Iran’s rural areas. The influence of government development policy, such as education and Income generating on rural women was sought and investigated in this study. This study particularly focuses on 3 important factors such as “ family income”, “ women’s education “ and “economic class of family” which represent economic, social and cultural status. The descriptive survey method has been applied in this research. The statistical population was 108682 households, from which 131 families were randomly selected. Data has gathered through questionnaires. The results suggest that However, rural development strategies would solve one problem for the women and create another. This paper argues that although rural development may have been beneficial to women and the society as a whole, it has implications for gender roles that go beyond the purview of women’s empowerment. These symptoms reflect a lack of structured development strategy to create new opportunities in these areas. As a result, despite the increasing in women education and family income there is a high rate of unemployment, because the current development policy clearly has failed to introduce new opportunities for women in labor market.
A NEW METHOD TO CLASSIFY BREAST CANCER TUMORS AND THEIR FRACTIONATION
Authors: Rahmani-Seryasat Omid , Haddadnia Javad , Ghayoumi-Zadeh Hossein
Published: March 2017

http://dx.doi.org/10.5902/2179460X19428In this paper, suspicious breast tumors were classified by using the neural network and the growth area method has been used for a fractionation of the benign or malignant areas of the normal tissue. Features extracted from input tissues are including statistical features and characteristics of spatial dependence. The advantage of this method is using of phase adaptive threshold based on entropy which leads to more accurate extraction of tumors and also corresponded with the nature of mammogram images. As a result, this method mimics of the human eye operation to detect abnormal masses. Database used in this paper is the MIAS mammogram database including 238 normal, benign and malignant mammograms. The accuracy obtained with 38 features is equal to 86.66% for detecting abnormal masses and 38.05 % for normal masses.
COMPARISON OF TWO JACUZZIS AND SWIMMING MILD RECOVERIES ON HEART BEAT RATE AND MYOCARDIAL OXYGEN CONSUMPTION OF SWIMMING
Authors: Aminian Ensiyeh
Published: March 2017

http://dx.doi.org/10.5902/2179460X19445Main aim of this research was comparing effect of two Jacuzzis, swimming mild recoveries on heart beat rate, and myocardial oxygen cost of swimming. Initially normal data distribution Kolmogorov Smirnov test was used in order to reflect the normal distribution of data. For data analysis descriptive statistics were used (placebo, median, mean, variance, and standard deviation) in order to compare changes of Lactic acid of heart rate beat and consumption oxygen of myocardial. Therefore, we used t student, alpha error is 0.05, and Excel 2007 and SPSS 18 did analysis. Result of research indicated that inactive recovery was effective on faster excreted lactic acid. Moreover, results of research indicated that recovery on mild swim Jacuzzi was effective on heart rate, myocardial consumption of oxygen. In addition, results of research indicated that heart rate and myocardial consumption of oxygen reduce in Jacuzzi recovery.
A New PSO Classifier Based Method Applied to Detect Anomalies of the Larynx
Authors: Salehi Fatemeh , Emadi Mehran
Published: March 2017

Quality of the human voice can be affected by anomalies of the larynx due to the physical, Nerve-muscle or only nervous origins. Video Stroboscope and vocal folds movement display systems are key tools which often used to detect Laryngeal anomalies. These methods are invasive, time consuming and expensive, so researchers are trying to find non-invasive methods that lead to the final answers faster than invasive methods and contain tolerable condition for patients. Many interests are directed to the application of speech processing techniques in relevant works. In these works, researchers were used different processing methods in medical engineering to detect anomalies. Recently, variety of researches presented to detect anomalies from the audio signals of individuals based on the features that extracted from audio signals. These methods have been conducted to separate patient audio from non-patient once. These researches do not work properly when an anomaly is among several anomalies and achieve bad error rate. In this paper, we aim to propose a new method of automatic Anomalies detection which performs based on a new mechanism of feature extraction and a PSO classifier. In the proposed work, Feature extraction is done in three ways, the first depending on MFCC features and the second depending on Jitter and Shimmer features and the third by combining MFCC and Jitter and Shimmer. Meanwhile, achieved features are used along with PSO algorithm to analysis and classify anomalies based on several classes. Also, we used four groups of anomalies and a class of normal voice as benchmark data sets and evaluated and compared the proposed method with different feature extraction strategy. Our simulations results confirm the superior performance of the proposed method, especially when the features are extracted based on combination of MFCC and Jitter Shimmer. The result from the combination is 80% and using MFCC alone is 66% and using Shimmer and Jitter is 43%.
Parallel Genetic Algorithm for Shortest Path Routing Problem with Collaborative Neighbors
Authors: Roshani Reza , Sohrabi Mohammad Karim
Published: March 2017

Shortest path routing is generally known as a kind of routing widely availed in computer networks nowadays. Although advantageous algorithms exist for finding the shortest path, however alternative methods may have their own supremacy. In this paper, parallel genetic algorithm for finding the shortest path routing is resorted to. In order to improve the computation time in this routing algorithm and to distribute the load balance between the processors as well, Fine-Grained parallel GA model is opted for. The proposed algorithm was simulated on Wraparound Mesh network topologies in different sizes. To this end, several experiments were anchored to identify the most influential parameters such as Migration rate, Mutation rate, and Crossover rate. The simulation result shows that best result of mutation rate is: about 0.02 and 0.03, and migration rate for transmission to the neighbor’s node is 3 of the best chromosomes. This study has already shown that through using performance-based GA which uses fine-grained parallel algorithms, timing germane shortest path routing can be improved.
Broad Band Equal-Length And Equal-Width Substrate Integrated Waveguide Four Channel Power Divider
Authors: Eslamloo Masoud Khoubroo , Mohammadi Pejman
Published: March 2017

In this letter a novel broad band substrate integrated waveguide (SIW) power divider is proposed. It consist of four output channels made by SIW with equal length and equal width. Design equations and process are given with mathematical analysis. The propagation constant of the output signals have been adjusted by utilize only four via in the middle of the output arms. As a result a novel equal output power divider, is obtained accordingly. The experimental results of a prototype at 10 GHz shows 3.1 GHz bandwidth in both simulation and measurement results. Return loss and transmission coefficients have good agreement with simulation results in considered band.
Effect of Temperature on thermodynamic parameters and chemical properties at adsorption process nitrite on the Graphene Nano surface, density functional theory method
Authors: Ahmadi Roya , Farajpour Eysa
Published: March 2017

The project is comparing four types of calculation derived graphene. That two of these derivatives of graphene carbon nitrite connection created the difference is only in the state of Para and meta carbons connectivity state. But other derivatives first silicon-carbon alternatives in the meta and para position, then nitrite is added to the silicon. To evaluate the effect of silicon element to absorb energy and other thermodynamic parameters in the derivatives compared with them.
Computational study adsorption of mercaptopurine in generation G3 and G5 PAMAM dendrimers
Authors: Ashrafi Frydon , Mahbobi Tahereh , Ghasemi Ashraf Sadat
Published: March 2017

Due to its unique properties of dendrimers as well as with high-level groups, a special ability to carry drugs. In this study compared the interaction between the two generations of poly (amidoamine) PAMAM (G3and G5) dendrimers and the drug 6-mercaptopurine (6-MP) and the drug entrapment within the structure of dendrimers the electrostatic and covalent complexation of drugs to the dendrimer surface have been studied. The use of drug-dendrimer complex enhanced drug solubility and bioavailability of the drug.
Design a mechanism Like flapping hummingbird wings
Authors: Javareshkian Mohamad Hasan , Vashani Mehdi Behnam
Published: March 2017

Hummingbirds have been considered because they have high maneuverability. Making an example of this type of bird needs to observe the kinematic and aerodynamic issues of the bird’s flight. In this article the locus of attack angle and instantaneous elevation is studied to be used for constructing a sample of birds. At first, the charts offered in the article of bird’s flight was digitized and by using MATLAB software was fitted to the shape of a sinusoidal equation to be comparable with designed mechanisms. The designed mechanisms have three variables that by using EES software the motion equation has been approached. Then by the Lagrange Interpolation the effect of each variable in the equation of motion mechanism obtained. Finally by using EES software these equation is solved and the amount of the variables was calculated.
Interaction in coherence of rural paths levels in Iranian architecture and urbanization (Case study: rural architecture of Iran)
Authors: Leilian Mohammadreza , Mirzaee Vahid , Bemanian Mohammadreza , Saremi Hamidreza , Ahmadnejad Mehran
Published: March 2017

One of characteristics of urbanization in old Iran has been its ways and paths fabric. This characteristic was generally formed in all climates in regard to available substances and materials. This principle has been creating visual coherence, order, and hierarchy. Framework of rural paths is a distinctive example in this regard. The main objective is to exemplify connective coherence of frameworks, surface, roofs, and physical aspects of Iran’s rural architecture as an indication for urbanization in contemporary architecture. So ways and paths of Iran’s architecture and urbanization are studied in this paper by means of a descriptive analytical method, and the data is compiled by field, documentary research. The result of present study is the answer to this question: How can revitalize a city within physical, semantic, and connecting aspects using interaction in coherence of paths components in Iran’s architecture and urbanization?
A Study of the Construction of Female Identity: John Fowles’ The French Lieutenant’s Woman
Authors: Golestani Narjes Tashakor
Published: March 2017

The issue of identity and female consciousness as one of the major concerns of feminists has always been polemical, for there are different attitudes in formulating gender identity and consequently defining what a woman is. As its theoretical framework, this study relies on Judith Butler’s theory of gender and sexuality and studies the construction of identity in the female characters of John Fowles’ The French Lieutenant’s Woman. Judith Butler, a feminist constructivist, stresses the effect of socially constructed gender roles on creating gender identity and proposes her performative theory of gender and sexuality. In her theory Butler argues that gender is not what one is but what one does. In this sense, gender is not a stable identity from which various acts proceed; rather it is an identity constituted through a stylized repetition of normative gender roles and performances. Regarding gender as performative reveals that, what is taken as an internal essence of gender is actually fabricated through the regulatory frame of interacting discourses. It has an imitative structure which can be deconstructed. The study, thus, focuses on the effect of prescribed gender roles and norms in the process of identity formation, and examines Ernestina Freeman as a conformist character who constitutes her identity by taking on the ideal gender norms of the era and Sarah woodruff who tries to renegotiate and reenact those roles and constructs a sense of self which transcends constraints of the social and cultural hegemonic frame.
The effect of soil stiffness variations on Tunnel Lining Internal Forces under seismic loading and Case comparison with existing analytical methods
Authors: Zamani Reza , Motahari M.R.
Published: March 2017

Closed-form solutions are of great interest for quick and accurate evaluation of stresses and displacements around underground excavations. Dynamic effects on underground structures have often been neglected based on the assumption that their response to earthquake loading is relatively safe as compared to that of surface structures. Nevertheless, several examples of recorded damage to underground structures for which seismic forces were not considered in the original design. Therefore, during the seismic excitement, tunnels are basically subjected to three kinds of deformation : axial compression and extension, longitudinal bending and ovaling or racking. In the present investigation a series of numerical analyses under the influence of soil hardness parameters based on no-slip between soil and tunnel lining were performed, using finite element code PLAXIS, and outputs were compared with result of analytical solutions.
IN VITRO ANTIPLASMODIAL ACTIVITY OF FLOWER EXTRACTS FROM COMBRETUM LEPROSUM MART (MOFUMBO)
Authors: Passarini Guilherme Matos , Medeiros Daniel Sol , Meneguetti Dionatas Ulisses de Oliveira , Lima Renato Abreu , Facundo Valdir Alves , Medeiros Patrícia Soares de Maria de
Published: March 2017

Malaria is the cause of hundreds of deaths per year , besides putting billions of people at risk of developing disease. When it comes to its therapy, the drugs used currently are losing its efficacy due to increase inn the frequency of resistant strains of the parasite, highlight the importance for the serach of new classes of molecules prsentign antiplasmodial activity. In the present work, the antiplasmodial activities of five extracts from the flowers of Comretum leprosum are described. The method employed for obtaingine the extracts was silica gel column chromatography, and the techniques used for the analysis of antiplasmodial activity and citotoxicity were ELISA and MTT respectively, were a selectivitu index was calculated after the obtainign of these two values. The extract presenting the highest antiplasmodial activity was the chloroform extract, however, this extrac also presented the higther cytotoxicity and therefore the extract presenting the best overall activity was the hexane extract. The study deminstrated the plant Combretum leprosum has active substances against P. falciparum and therefore is a potential to be expored in funther pharmacological studies.
THE BETA-WEIBULL DISTRIBUTION ON THE LATTICE OF INTEGERS
Authors: Nekoukhou Vahid , Bidram Hamid , Roozegar Rasool
Published: March 2017

In this paper, a discrete analog of the beta-Weibull distribution is studied. This new distribution contains several discrete distributions as special sub-models. Some distributional and moment properties of the discrete beta-Weibull distribution as well as its order statistics are discussed. We will show that the hazard rate function of the new model can be increasing, decreasing, bathtub-shaped and upside-down bathtub. Estimation of the parameters is illustrated and the model with a real data set is also examined.
Anatomia da madeira de Ternstroemia brasiliensis Cambess. (Pentaphylacaceae)
Authors: Melo Júnior João Carlos Ferreira , Amorim Maick William , Arriola Igor Abba
Published: March 2017

O presente estudo descreve e ilustra a anatomia do lenho de Ternstroemia brasiliensis (Pentaphylacaceae) a partir de coletas realizadas em ambiente de restinga de Santa Catarina, Brasil. Os caracteres anatômicos mais representativos são: vasos de pequeno diâmetro tangencial e elevada frequência, espessamento espiralado em elementos de vasos, traqueíde vasicêntrica, placa de perfuração escalariforme, parênquima axial apotraqueal difuso e raios heterogêneos extremamente altos. A conjunção destes caracteres indica a primitividade do lenho desta espécie.
Ensino de Matemática no Curso Técnico Integrado em Edificações e Informática: reflexões a respeito de uma ação realizada
Authors: Rosotti de Andrade Susimeire Vivien , Stefanello Somavilla Adriana
Published: March 2017

O objetivo deste artigo é apresentar reflexões das contribuições para o desenvolvimento matemático dos alunos do 1º ano do curso Técnico Integrado em Edificações e Informática do Instituto Federal do Paraná - Campus de Foz do Iguaçu, no decorrer da participação do projeto de extensão desenvolvido semanalmente no segundo semestre do ano de 2013. Os resultados das avaliações dos alunos participantes do projeto indicaram melhoria gradativa no desempenho escolar em matemática e disciplinas afins. O desenvolvimento das atividades do projeto em turno oposto e de forma facultativa, com maneiras diferentes de abordar os conteúdos e avaliação, oportunizou um ambiente crítico e de autonomia para o processo de ensino e aprendizagem.
Drought‐Proofing Water Pump Stations for Critical Infrastructure
Authors: Johansson Andrew E. , Schowalter David G. , Orlins Joseph , Rashid Mizan
Published: March 2017

Five strategies can help water utilities protect their water pump stations against drought.
What the Hippies Did
Authors: Lafrance David B.
Published: March 2017

LaFrance points out that today's retiring bankers, electricians, lawyers, teachers, doctors, and even water professionals were not always as we see them now. Many of them quite possibly were long‐haired, VW bus‐driving, tie‐dye‐wearing, Summer of Love‐participating (1967), Woodstock‐going (1969) hippies. Did this subculture or counterculture of 50 (plus or minus) years ago have an impact?
Personal therapy for therapists: Reflections on past and current research from an autoethnographic perspective
Authors: Kumari Nina
Published: March 2017

The following article will describe and reflect on a research study that was published in Counselling Psychology Quarterly in 2011, entitled ‘Personal Therapy as a Mandatory Requirement for Counselling Psychologists in Training: A Qualitative Study of the Impact of Therapy on Trainees’ Personal and Professional Development.’ The aim of the study was to explore trainee counselling psychologists’ experiences of mandatory personal therapy, and the impact it had on their personal and professional development. This article is written from an autoethnographic perspective. Autoethnography is a research method which allows authors to define, explain and methodically evaluate their personal experiences of being part of a particular culture, over a prolonged period of time. The use of the dialogue approach has allowed the study to be presented as an interview or a conversation that has taken place between two people. The article concentrates on three areas of autoethnography: firstly, sincerity which is interested in the author’s objectives and the ways in which a study is designed, carried out, and presented. Secondly, contribution is about the significance of participants’ stories and the ways in which they are interpreted. The standard of any research study is judged on the extent to which the work has furthered knowledge and understanding of a particular subject area. Thirdly, rich insight, involves an idiosyncratic process of self-reflection for the researcher to gain insight into their area of interest.
SMOC can act as both an antagonist and an expander of BMP signaling
Authors: Thomas J Terrig , Eric Dollins D , Andrykovich Kristin R , Chu Tehyen , Stultz Brian G , Hursh Deborah A , Moos Malcolm
Published: March 2017

The matricellular protein SMOC (Secreted Modular Calcium binding protein) is conserved phylogenetically from vertebrates to arthropods. We showed previously that SMOC inhibits bone morphogenetic protein (BMP) signaling downstream of its receptor via activation of mitogen-activated protein kinase (MAPK) signaling. In contrast, the most prominent effect of the Drosophila orthologue, pentagone (pent), is expanding the range of BMP signaling during wing patterning. Using SMOC deletion constructs we found that SMOC-∆EC, lacking the extracellular calcium binding (EC) domain, inhibited BMP2 signaling, whereas SMOC-EC (EC domain only) enhanced BMP2 signaling. The SMOC-EC domain bound HSPGs with a similar affinity to BMP2 and could expand the range of BMP signaling in an in vitro assay by competition for HSPG-binding. Together with data from studies in vivo we propose a model to explain how these two activities contribute to the function of Pent in Drosophila wing development and SMOC in mammalian joint formation.
Activity patterns of serotonin neurons underlying cognitive flexibility
Authors: Matias Sara , Lottem Eran , Dugué Guillaume P , Mainen Zachary F
Published: March 2017

Serotonin is implicated in mood and affective disorders. However, growing evidence suggests that a core endogenous role is to promote flexible adaptation to changes in the causal structure of the environment, through behavioral inhibition and enhanced plasticity. We used long-term photometric recordings in mice to study a population of dorsal raphe serotonin neurons, whose activity we could link to normal reversal learning using pharmacogenetics. We found that these neurons are activated by both positive and negative prediction errors, and thus report signals similar to those proposed to promote learning in conditions of uncertainty. Furthermore, by comparing the cue responses of serotonin and dopamine neurons, we found differences in learning rates that could explain the importance of serotonin in inhibiting perseverative responding. Our findings show how the activity patterns of serotonin neurons support a role in cognitive flexibility, and suggest a revised model of dopamine–serotonin opponency with potential clinical implications.
Fast-spiking GABA circuit dynamics in the auditory cortex predict recovery of sensory processing following peripheral nerve damage
Authors: Resnik Jennifer , Polley Daniel B
Published: March 2017

Cortical neurons remap their receptive fields and rescale sensitivity to spared peripheral inputs following sensory nerve damage. To address how these plasticity processes are coordinated over the course of functional recovery, we tracked receptive field reorganization, spontaneous activity, and response gain from individual principal neurons in the adult mouse auditory cortex over a 50-day period surrounding either moderate or massive auditory nerve damage. We related the day-by-day recovery of sound processing to dynamic changes in the strength of intracortical inhibition from parvalbumin-expressing (PV) inhibitory neurons. Whereas the status of brainstem-evoked potentials did not predict the recovery of sensory responses to surviving nerve fibers, homeostatic adjustments in PV-mediated inhibition during the first days following injury could predict the eventual recovery of cortical sound processing weeks later. These findings underscore the potential importance of self-regulated inhibitory dynamics for the restoration of sensory processing in excitatory neurons following peripheral nerve injuries.
Stella modulates transcriptional and endogenous retrovirus programs during maternal-to-zygotic transition
Authors: Huang Yun , Kim Jong Kyoung , Do Dang Vinh , Lee Caroline , Penfold Christopher A , Zylicz Jan J , Marioni John C , Hackett Jamie A , Surani M Azim
Published: March 2017

The maternal-to-zygotic transition (MZT) marks the period when the embryonic genome is activated and acquires control of development. Maternally inherited factors play a key role in this critical developmental process, which occurs at the 2-cell stage in mice. We investigated the function of the maternally inherited factor Stella (encoded by Dppa3) using single-cell/embryo approaches. We show that loss of maternal Stella results in widespread transcriptional mis-regulation and a partial failure of MZT. Strikingly, activation of endogenous retroviruses (ERVs) is significantly impaired in Stella maternal/zygotic knockout embryos, which in turn leads to a failure to upregulate chimeric transcripts. Amongst ERVs, MuERV-L activation is particularly affected by the absence of Stella, and direct in vivo knockdown of MuERV-L impacts the developmental potential of the embryo. We propose that Stella is involved in ensuring activation of ERVs, which themselves play a potentially key role during early development, either directly or through influencing embryonic gene expression.
Toxoplasma gondii F-actin forms an extensive filamentous network required for material exchange and parasite maturation
Authors: Periz Javier , Whitelaw Jamie , Harding Clare , Gras Simon , Del Rosario Minina Mario Igor , Latorre-Barragan Fernanda , Lemgruber Leandro , Reimer Madita Alice , Insall Robert , Heaslip Aoife , Meissner Markus
Published: March 2017

Apicomplexan actin is important during the parasite's life cycle. Its polymerization kinetics are unusual, permitting only short, unstable F-actin filaments. It has not been possible to study actin in vivo and so its physiological roles have remained obscure, leading to models distinct from conventional actin behaviour. Here a modified version of the commercially available actin-chromobody was tested as a novel tool for visualising F-actin dynamics in Toxoplasma gondii. Cb labels filamentous actin structures within the parasite cytosol and labels an extensive F-actin network that connects parasites within the parasitophorous vacuole and allows vesicles to be exchanged between parasites. In the absence of actin, parasites lack a residual body and inter-parasite connections and grow in an asynchronous and disorganized manner. Collectively, these data identify new roles for actin in the intracellular phase of the parasites lytic cycle and provide a robust new tool for imaging parasitic F-actin dynamics.
Contact-dependent killing by Caulobacter crescentus via cell surface-associated, glycine zipper proteins
Authors: García-Bayona Leonor , Guo Monica S , Laub Michael T
Published: March 2017

Most bacteria are in fierce competition with other species for limited nutrients. Some bacteria can kill nearby cells by secreting bacteriocins, a diverse group of proteinaceous antimicrobials. However, bacteriocins are typically freely diffusible, and so of little value to planktonic cells in aqueous environments. Here, we identify an atypical two-protein bacteriocin in the α-proteobacterium Caulobacter crescentus that is retained on the surface of producer cells where it mediates cell contact-dependent killing. The bacteriocin-like proteins CdzC and CdzD harbor glycine-zipper motifs, often found in amyloids, and CdzC forms large, insoluble aggregates on the surface of producer cells. These aggregates can drive contact-dependent killing of other organisms, or Caulobacter cells not producing the CdzI immunity protein. The Cdz system uses a type I secretion system and is unrelated to previously described contact-dependent inhibition systems. However, Cdz-like systems are found in many bacteria, suggesting that this form of contact-dependent inhibition is common.
Testing of microsatellite multiplexes for individual identification of Cape Parrots (Poicephalus robustus): paternity testing and monitoring trade
Authors: Coetzer Willem G. , Downs Colleen T. , Perrin Mike R. , Willows-Munro Sandi
Published: March 2017

Background

Illegal trade in rare wildlife species is a major threat to many parrot species around the world. Wildlife forensics plays an important role in the preservation of endangered or threatened wildlife species. Identification of illegally harvested or traded animals through DNA techniques is one of the many methods used during forensic investigations. Natural populations of the South African endemic Cape Parrot (Poicephalus robustus) are negatively affected by the removal of eggs and chicks for the pet trade.

Methods

In this study, 16 microsatellite markers specifically designed for the South African endemic Cape Parrot (P. robustus) are assessed for their utility in forensic casework. Using these 16 loci, the genetic diversity of a subset of the captive Cape Parrot population was also assessed and compared to three wild Cape Parrot populations.

Results

It was determined that the full 16 locus panel has sufficient discriminatory power to be used in parentage analyses and can be used to determine if a bird has been bred in captivity and so can be legally traded or if it has been illegally removed from the wild. In cases where birds have been removed from the wild, this study suggests that a reduced 12 locus microsatellite panel has sufficient power to assign confiscated birds to geographic population of origin.

Discussion

The level of genetic diversity observed within the captive Cape Parrot population was similar to that observed in the wild populations, which suggests that the captive population is not suffering from decreased levels of genetic diversity. The captive Cape Parrots did however have double the number of private alleles compared to that observed in the most genetically diverse wild population. This is probably due to the presence of rare alleles present in the founder population, which has not been lost due to genetic drift, as many of the individuals tested in this study are F1–F3 wild descendants. The results from this study provide a suit of markers that can be used to aid conservation and law enforcement authorities to better control legal and illegal trade of this South African endemic.
A multidisciplinary approach to digital mapping of dinosaurian tracksites in the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia
Authors: Romilio Anthony , Hacker Jorg M. , Zlot Robert , Poropat George , Bosse Michael , Salisbury Steven W.
Published: March 2017

The abundant dinosaurian tracksites of the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia, form an important part of the West Kimberley National Heritage Place. Previous attempts to document these tracksites using traditional mapping techniques (e.g., surface overlays, transects and gridlines combined with conventional photography) have been hindered by the non-trivial challenges associated with working in this area, including, but not limited to: (1) the remoteness of many of the tracksites; (2) the occurrence of the majority of the tracksites in the intertidal zone; (3) the size and complexity of many of the tracksites, with some extending over several square kilometres. Using the historically significant and well-known dinosaurian tracksites at Minyirr (Gantheaume Point), we show how these issues can be overcome through the use of an integrated array of remote sensing tools. A combination of high-resolution aerial photography with both manned and unmanned aircraft, airborne and handheld high-resolution lidar imaging and handheld photography enabled the collection of large amounts of digital data from which 3D models of the tracksites at varying resolutions were constructed. The acquired data encompasses a very broad scale, from the sub-millimetre level that details individual tracks, to the multiple-kilometre level, which encompasses discontinuous tracksite exposures and large swathes of coastline. The former are useful for detailed ichnological work, while the latter are being employed to better understand the stratigraphic and temporal relationship between tracksites in a broader geological and palaeoecological context. These approaches and the data they can generate now provide a means through which digital conservation and temporal monitoring of the Dampier Peninsula’s dinosaurian tracksites can occur. As plans for the on-going management of the tracks in this area progress, analysis of the 3D data and 3D visualization will also likely provide an important means through which the broader public can experience these spectacular National Heritage listed landscapes.
Evolution of the patellar sesamoid bone in mammals
Authors: Samuels Mark E. , Regnault Sophie , Hutchinson John R.
Published: March 2017

The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition) and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.
Ecohydrological Dynamics and Temporal Water Origin in a European Mediterranean Vineyard
Authors: Benettin Paolo , Tagliavini Massimo , Andreotti Carlo , di Villahermosa Francesca Sofia Manca , Verdone Matteo , Dani Andrea , Penna Daniele
Published: October 2024

Viticulture is an essential sector in agriculture as wine production plays a vital role in the socio‐economic life of many countries, especially in the Mediterranean area. Grapevines are a valuable, long‐lived species able to grow in hot and dry regions. We currently do not know whether rain‐fed grapevines entirely rely on deep soil water or make substantial use of shallow water from summer precipitation events. Without knowing this, we poorly understand what fraction of summer precipitation inputs contributes to grapevine transpiration. This has implications for how we quantify grapevine‐relevant precipitation budgets and for predicting the impacts of climate change on grape and wine production. We investigated grapevine water use in a vineyard in the Chianti region, central Italy. During the growing season of 2021, we monitored precipitation and soil moisture at 30‐ and 60‐cm depth. We collected over 250 samples for stable isotope analysis from rainfall, soil, and plants. Since traditional plant water sampling is problematic for grapevines, we collected samples from shoots, leaves, and condensed leaf transpiration after sealed plastic bags were wrapped around a shoot. We use these alternative plant samples to reconstruct the isotopic signal in the xylem water and infer the plant's seasonal water origin throughout the growing season. The analysis of the seasonal origin of water revealed that, throughout the growing season, soil water and plant water received disproportional contributions by rain that had fallen in the winter, even when compensating for the Mediterranean climate of the area. Only in late summer did the grapevines use substantial amounts of summer rainfall, whose contribution occasionally became dominant. These results provide a better understanding of ecohydrological interactions and uptake dynamics in valuable socio‐economic agroecosystems such as vineyards.
Depressive symptoms and goal pursuit: Between‐person and reciprocal within‐person effects in a multi‐wave longitudinal study
Authors: Leduc‐Cummings Isabelle , Milyavskaya Marina , Howard Andrea L. , Drapeau Martin
Published: October 2024

Introduction

Depressive symptoms, goal progress, and goal characteristics are interrelated, but the directionality of these relationships is unclear.

Methods

In a 6‐wave longitudinal study (N = 431; 2002 total surveys), we examine the bidirectionality of the relationships between depressive symptoms, goal characteristics (commitment, self‐efficacy, and perception of other's support), and goal progress for academic and interpersonal goals at 2‐week intervals. Separate random‐intercept cross‐lagged panel models were tested for each goal characteristic across both goals.

Results

At the within‐person level, goal progress significantly positively predicted commitment, self‐efficacy, and perception of others' support for the goal. Most of the other hypothesized paths were nonsignificant, including paths between depressive symptoms and progress. At the between‐person level, all variables were significantly correlated, with some effects significantly larger for the interpersonal than the academic goal.

Discussion

The results suggest that when it comes to depressive symptoms and goal pursuit, general tendencies may be more important than variations over 2‐week intervals.