bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rostrocaudal Areal Patterning of Human PSC-Derived Cortical Neurons by FGF8 Signaling
Authors: Imaizumi Kent , Fujimori Koki , Ishii Seiji , Otomo Asako , Hosoi Yasushi , Miyajima Hiroaki , Warita Hitoshi , Aoki Masashi , Hadano Shinji , Akamatsu Wado , Okano Hideyuki 
Published: April 2018

AbstractThe cerebral cortex is subdivided into distinct areas that have particular functions. The rostrocaudal (R-C) gradient of fibroblast growth factor 8 (FGF8) signaling defines this areal identity during neural development. In this study, we recapitulated cortical R-C patterning in human pluripotent stem cell (PSC) cultures. Modulation of FGF8 signaling appropriately regulated the R-C markers, and the patterns of global gene expression resembled those of the corresponding areas of human fetal brains. Furthermore, we demonstrated the utility of this culture system in modeling the area-specific forebrain phenotypes [presumptive upper motor neuron (UMN) phenotypes] of amyotrophic lateral sclerosis (ALS). We anticipate that our culture system will contribute to studies of human neurodevelopment and neurological disease modeling.
Decreased G-Protein-Mediated Regulation and Shift in Calcium Channel Types with Age in Hippocampal Cultures
Authors: Blalock Eric M. , Porter Nada M. , Landfield Philip W. 
Published: April 2018

The membrane density of L-type voltage-sensitive Ca2+channels (L-VSCCs) of rat hippocampal neurons increases over age [daysin vitro(DIV)] in long-term primary cultures, apparently contributing both to spontaneous cell death and to enhanced excitotoxic vulnerability. Similar increases in L-VSCCs occur during brain agingin vivoin rat and rabbit hippocampal neurons. However, unraveling both the molecular basis and the functional implications of these age changes in VSCC density will require determining whether the other types of high-threshold VSCCs (e.g., N, P/Q, and R) also exhibit altered density and/or changes in regulation, for example, by the important G-protein-coupled, membrane-delimited inhibitory pathway. These possibilities were tested here in long-term hippocampal cultures.Pharmacologically defined whole-cell currents were corrected for cell size differences over age by normalization with whole-cell capacitance. The Ca2+channel current density (picoamperes per picofarad), mediated by each Ca2+channel type studied here (L, N, and a combined P/Q + R component), increased through 7 DIV. Thereafter, however, only L-type current density continued to increase, at least through 21 DIV. Concurrently, pertussis toxin-sensitive G-protein-coupled inhibition of non-L-type Ca2+channel current induced by the GABABreceptor agonist baclofen or by guanosine 5′-3-O-(thio)triphosphate declined dramatically with age in culture. Thus, the present studies identify selective and novel parallel mechanisms for the time-dependent alteration of Ca2+influx, which could importantly influence function and vulnerability during development and/or aging.
Firing Patterns and Correlations of Spontaneous Discharge of Pallidal Neurons in the Normal and the Tremulous 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Vervet Model of Parkinsonism
Authors: Raz Aeyal , Vaadia Eilon , Bergman Hagai 
Published: April 2018

To investigate the role of the basal ganglia in parkinsonian tremor, we recorded hand tremor and simultaneous activity of several neurons in the external and internal segments of the globus pallidus (GPe and GPi) in two vervet monkeys, before and after systemic treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and development of parkinsonism with tremor of 5 and 11 Hz.In healthy monkeys, only 11% (20/174) of the GPe cells and 3% (1/29) of the GPi cells displayed significant 3–19 Hz oscillations. After MPTP treatment, 39% (107/271) of the GPe cells and 43% (26/61) of the GPi cells developed significant oscillations. Oscillation frequencies of single cells after MPTP treatment were bimodally distributed around 7 and 13 Hz. For 10% of the oscillatory cells that were recorded during tremor periods, there was a significant tendency for the tremor and neuronal oscillations to appear simultaneously.Cross-correlation analysis revealed a very low level of correlated activity between pallidal neurons in the normal state; 95.6% (477/499) of the pairs were not correlated, and oscillatory cross-correlograms were found in only 1% (5/499) of the pairs. After MPTP treatment, the correlations increased dramatically, and 40% (432/1080) of the cross-correlograms had significant oscillations, centered around 13–14 Hz. Phase shifts of the cross-correlograms of GPe pairs, but not of GPi, were clustered around 0°.The results illustrate that MPTP treatment changes the pattern of activity and synchronization in the GPe and GPi. These changes are related to the symptoms of Parkinson's disease and especially to the parkinsonian tremor.
A Series of Biotinylated Tracers Distinguishes Three Types of Gap Junction in Retina
Authors: Mills Stephen L. , Massey Stephen C. 
Published: April 2018

Gap junctions serve many important roles in various tissues, but their abundance and diversity in neurons is only beginning to be understood. The tracer Neurobiotin has revealed many different networks interconnected by gap junctions in retina. We compared the relative permeabilities of five different retinal gap junctions by measuring their permeabilities to a series of structurally related tracers. When large tracers were injected, the staining of coupled cells fell off more rapidly in some networks than others relative to Neurobiotin controls. Three distinctly different permeability profiles were found, suggesting that multiple neuronal connexin types were present. The most permeant to large molecules were gap junctions from A-type horizontal cells. The permeability of gap junctions of two types of amacrine cell were not distinguishable from those from B-type horizontal cells. The lowest permeability was found for gap junctions between cone bipolar cells and the AII amacrine cells to which they are coupled. Because only a single neural connexin type has been identified in retina, our results suggest more types remain to be found.To determine whether the unitary permeability of channels is altered by channel modulators, we reduced permeability with octanol and a cAMP analog. Although net permeability was substantially diminished, the proportion by which it declined was constant across tracer size. This suggests that these agents act only to close channels rather than alter individual channel permeabilities. This tracer series can therefore be used to contrast permeability properties of gap junctions in intact circuits, even at the level of individual channels.
Directional Avoidance Turns Encoded by Single Interneurons and Sustained by Multifunctional Serotonergic Cells
Authors: Jing Jian , Gillette Rhanor 
Published: April 2018

Avoidance turns in the sea slugPleurobranchaeaare responses to noxious stimuli and replace orienting turns to food stimuli after avoidance conditioning or satiation. Avoidance turns proved to be centrally patterned behaviors, the fictive expression of which could be elicited in reduced preparations and the isolated CNS. Activity in one of a bilateral interneuron pair, the A4 cells, was necessary and sufficient to drive the avoidance turn toward the contralateral side. Single A4 cells appeared to encode both turn direction and angle, in contrast to directional behaviors of other animals in which displacement angle is usually encoded by multiple units.The As1–4 cells, bilateral serotonergic cell clusters, excited the prolonged A4 burst during the turn through electrical and chemical coupling. However, during the escape swim, As1–4 became integral elements of the swim motor network, and A4 activity was entrained to the swim rhythm by alternating excitatory–inhibitory inputs, with only weak spiking. This provides a likely mechanism for the previously observed suppression of the avoidance turn by escape swimming. These observations add significant new aspects to the multiplying known functions of As1–4 and their homologs in other molluscs and point to a pivotal role of these neurons in the organization of gastropod behavior.Simple functional models predict (1) the essential actions of inhibitor neurons in the directionality of the turning network motor output and (2) an integrating role for As1–4 in the behavioral switch between turning avoidance and swimming escape, on the basis of their response to increasing stimulus intensity.
Separation-Induced Receptor Changes in the Hippocampus and Amygdala ofOctodon degus: Influence of Maternal Vocalizations
Authors: Ziabreva Irina , Poeggel Gerd , Schnabel Reinhild , Braun Katharina 
Published: April 2018

Relatively little is known about the basic mechanisms that play a role in the vulnerability of the developing brain toward adverse environmental influences. Our study in the South American rodentOctodon degusrevealed that repeated brief separation from the parents and exposure to an unfamiliar environment induces in the hippocampal formation of male and female pups an upregulation of D1and 5-HT1Areceptor density in the stratum radiatum and stratum lacunosum moleculare of the CA1 region. In the CA3 region, only the 5-HT1Areceptors were upregulated; no changes were observed for D1receptors in this region. GABAAreceptor density in the hippocampus and amygdala was downregulated (nonsignificant trend) after parental separation.The acoustic presence of the mother during parental separation suppressed the D1and 5-HT1Areceptor upregulation in some regions of the hippocampus; no such suppressing influence was observed for the GABAAreceptors. In the basomedial amygdala, the maternal calls enhanced the separation-induced 5-HT1Areceptor upregulation in the male pups, whereas in the female pups the separation-induced receptor densities were not only suppressed by the maternal call but further downregulated, compared with the control group. These results demonstrate that early adverse emotional experience alters aminergic function within the hippocampus and amygdala and that the mother's voice, a powerful emotional signal, can modulate these effects in the developing limbic system.
Glial Reactivity in Ciliary Neurotrophic Factor-Deficient Mice after Optic Nerve Lesion
Authors: Martin Aliki , Hofmann Hans-Dieter , Kirsch Matthias 
Published: April 2018

There is evidence that ciliary neurotrophic factor (CNTF), in addition to its neurotrophic activity, positively regulates astrogliosis after CNS injury. CNTF and its receptor, CNTFRα, are strongly upregulated in activated astrocytes. Application of CNTF upregulates GFAP expression in cultured astrocytes and induces various aspects of gliosis in the intact brain. Here we examined whether inactivation of the CNTF gene results in the expected changes in glial reactivity by analyzing gliosis in the superior colliculus (SC) after optic nerve crush.Basal expression levels of GFAP and vimentin in unlesioned CNTF-deficient mice were reduced by 66 and 37%, respectively. Absolute numbers of astrocytes were found not to be different. Surprisingly, however, lesion induced robust activation of astrocytes in CNTF-deficient mice; the time course of activation was even accelerated as compared with wild-type animals. At later time points, activation reached the same level. With respect to microglial cells, basal expression of microglial markers was unaltered in CNTF–knock-out animals. Lesion-induced upregulation of Iba-1, ICAM-1, and F4/80 in microglial cells was unaffected in CNTF-deficient animals. Differences were observed with respect to the time course of microglial activation, different markers being affected differentially. We further demonstrate that lesion induces upregulation of CNTF-related cytokines (LIF, NNT-1) and, interestingly, a more pronounced upregulation of cytokine receptor components (LIF receptor β, gp130) and TGFβ in CNTF-deficient animals. Our results thus indicate that CNTF is required for the development and maintenance of the mature astrocyte phenotype and provide evidence that CNTF is part of the complex regulatory network modulating lesional glial reactivity after lesion.
Mitogen-Activated Protein Kinase Signaling in the Hippocampus and Its Modulation by Corticotropin-Releasing Factor Receptor 2: A Possible Link between Stress and Fear Memory
Authors: Sananbenesi Farahnaz , Fischer André , Schrick Christina , Spiess Joachim , Radulovic Jelena 
Published: April 2018

A coordinated activation of multiple interlinked signaling pathways involving cAMP-dependent protein kinase (PKA) and mitogen-activated extracellular signal-regulated kinases (Mek-1/2) regulates gene expression and neuronal changes underlying memory consolidation. In the present study we investigated whether these molecular cascades might mediate the effects of stress on memory formation. We also investigated the role of hippocampal corticotropin-releasing factor receptor 2 (CRF2) in stress-enhanced learning and molecular signaling mediated by PKA, Mek-1/2, and their downstream targets extracellularly regulated kinases 1 and 2 (Erk-1/2) and p90-ribosomal-s-kinase-1 (p90Rsk-1).Acute 1 hr immobilization was used as a stressful stimulus, and one-trial context-dependent fear conditioning was used as a model for associative learning. Training of BALB/c mice 3 hr after the end of immobilization resulted in an enhancement of conditioned fear, as indicated by significantly increased freezing behavior of stressed when compared with nonstressed mice. Interestingly, Erk-1/2 phosphorylation after conditioning of nonstressed and stressed mice depended on PKA and Mek-1/2, respectively. Intrahippocampal injection of the selective Mek-1/2 inhibitor U0126 or CRF2antagonist antisauvagine-30 (aSvg-30) prevented stress-enhanced fear conditioning and Mek-1/2-dependent activation of Erk-1/2 and p90Rsk-1. aSvg-30 did not affect the phosphorylation of the PKA regulatory subunit II of stressed mice. The molecular and behavioral effects of CRF2coincided with stress-induced upregulation ofCRF2mRNA.These results suggest that modulation of Mek-1/2-dependent signaling by hippocampal CRF2can be selectively involved in the delayed effects of stress on memory consolidation.
Effect of amino acid substitution in New Delhi metallo-β-lactamase on carbapenem susceptibility
Authors: Düzgün Azer Özad 
Published: April 2018

The aim of this work was investigation of clinically important amino acid substitutions of NDM-1 variants. A blaNDM-1 gene was cloned into expression vector pET100/D-TOPO. The sequence of NDM-1 variants with substituted amino acids was determined by ClustalW program. A pET100/D-TOPO + blaNDM-1 was used to generate the alanine mutations at different positions, such as NDM-2 (P28A), NDM-3 (D95A), NDM-4 (M154A), NDM-5 (V88A), NDM-7 (D130A), and NDM-9 (E152A). The mutant variants were transformed into Escherichia coli DH5α. Changes in the activities of alanine mutation variants were determined by E-test. All samples had 32 μg/ml MIC values against ampicillin. The 28th amino acid mutation sample had the highest MIC value against ceftazidime, whereas decreased MIC value for piperacillin. It was observed that the resistance to imipenem was increased in mutant variants D95A, M154A, D130A, and E152A, comparing with P28A and V88A. It was found that NDM-1 has 0.64 μg/ml and the 130th amino acid mutation sample has 0.75 μg/ml meropenem MIC value.
Psikolojik Rahatlık Algısının Otantik Liderliğin Sinizmin Üzerindeki Etkisinde Aracı Rolü
Authors: YENER Serdar 
Published: April 2018

Bu
çalışmada örgütlerde otantik liderliğin sinizm üzerindeki etkisinde psikolojik
rahatlık algısının aracı rolü sorgulanmıştır. Otantik liderlik davranışı
liderlerin örgütte bireylerin düşünce, inanış,
kültürüne farkındalığını öne çıkaran davranışlarını ifade etmektedir. Otantik
liderliğin oluşturacağı güven ve hoşgörü kültürüyle psikolojik rahatlık
algısının ortaya çıkacabileceği düşünülmektedir. Psikolojik rahatlık algısı bireylerin
saygıya dayalı kişilerarası ilişkilerde psikolojik risk hissetmeden konuşması
ya da davranmasını ifade etmektedir. Sinizm bireylerin umutsuzluk, hayal
kırıklığı vb. olumsuz duygularla karşı tarafa olan güveninin sarsılması ve
inancının kaybolmasını ifade etmektedir.
Sinop ilinde aynı sektörde üretim yapan yerel fabrikaların 200 çalışanı üzerine
uygulanan anket sonuçlarına göre otantik
liderlik davranışlarının sinizme olumsuz etkisi gözlenirken psikolojik rahatlık
algısının kısmi aracılık etkisi de gözlenmiştir.
A CIÊNCIA NOS TRIBUNAIS: DECIDINDO SOBRE AÇÕES TECNOCIENTÍFICAS
Authors: Krepsky Giselle Marie , Barreto Thayane Cristine 
Published: April 2018

Este artigo trata da possibilidade de abertura cognitiva e aprendizagem do Sistema do Direito ao decidir questões envolvendo ações tecnocientíficas com potencial danoso futuro. À luz da teoria Sistêmica de Niklas Luhmann, para quem o Sistema Social é composto por vários subsistemas que são fechados operacionalmente, mas abertos cognitivamente, a pesquisa observou a inter-relação entre os Sistemas parciais da Ciência e do Direito com foco na capacidade de aprendizagem do Direito com as comunicações científicas. O objetivo da pesquisa foi identificar como o Direito vem decidindo sobre estas temáticas a partir da análise dos julgados dos Tribunais no contexto de hipercomplexidade social que potencializa o risco decisional. Conclui que o Sistema do Direito apresenta dificuldades ao decidir questões referentes às novas tecnologias uma vez que ele não possui na sua estrutura conhecimentos necessários para julgá-las. Isso leva a uma necessária decodificação das comunicações científicas (perícias) as quais norteiam boa parte das decisões. Por outro lado, o Sistema do Direito, embora capaz de assimilar e incorporar a informação científica, dela ainda mantém sua autonomia, mantendo sua autopoise.
GENEALOGIA AMBIENTAL E PRODUÇÃO DO CONHECIMENTO INTERDISCIPLINAR
Authors: Barreto Andrade Isabel Cristina Cristina , Souza Roberto Rodrigues , Silva Arleide Barreto , Souza Antonio Vital Menezes , Figueiredo Carla Taciane Taciane 
Published: April 2018

A produção do conhecimento nas ciências ambientais, nos últimos vinte anos, tem se caracterizado por uma polissemia teórica e metodológica. Assim, o campo das ciências ambientais pressupõe pesquisas rigorosas e politicamente engajadas numa dialogia na qual sejam explícitas a relações entre processo- pesquisador-objeto e problemáticas situadas em espaços de produção do conhecimento, dentre os quais se situam as ciências da natureza, as ciências humanas e sociais, as tecnologias. Faz-se necessário nortear esforços em direção do reconhecimento da compreensão de lacunas conceituais teóricas e metodológicas peculiares ao fazer cientifico. Nesse sentido esta pesquisa objetiva os estudo das raízes epistemológicas na produção de conhecimento nas ciências ambientais circunscritos na origem sociohistórica. De natureza teórica com caráter epistemológico que se insere na área do conhecimento das ciências ambientais. Os autores que fundamentam esse estudo no tema das ciências ambientais Phillip Jr. (2000), referindo-se a genealogia Foucault (1984,1999, 2001, 2006, 2008), quanto à epistemologia Grayling (1996) e Japiassu (1992), na perspectiva do método Gil (1999) e Macedo (2006, 2007). Os procedimentos metodológicos utilizados norteiam-se pelo paradigma multirreferencial, os instrumentos de coleta de dados são a pesquisa bibliográfica e documental e análise será realizada através da análise do conteúdo. Os resultados obtidos contribuirão com a reflexão epistemológica na produção do conhecimento em ciências ambientais. A produção teórico-conceitual de fundamentos serve de subsidio futuras pesquisas em ciências ambientais em torno da categoria “genealogia ambiental”; a contribuição do estudo com uma abordagem interdisciplinar responde alguns questionamentos pertinentes na produção científica das ciências ambientais. PALAVRAS-CHAVE: Genealogia. Produção de conhecimento. Interdisciplinaridade. Ciências Ambientais.
SEVERAL METHODS OF FEATURE EXTRACTION TO HELP IN OPTICAL CHARACTER RECOGNITION
Authors: Prasad Binod Kumar , Kundu Rajdeep 
Published: April 2018

An Optical Character Recognition (OCR) consists of three bold steps namely Preprocessing, Feature extraction, Classification. Methods of Feature extraction yield feature vectors based on which the classification of a testing pattern is executed. The paper aims at proposing some methods of feature extraction that may go a long way to recognize a Bengali numeral or character. Pixel Ex-OR Method presents a digital gating (Ex-OR) technique to extract the information in an image. Two successive elements of a row in image matrix have been Ex-ORed and the output is again Ex-ORed with the next element. Alphabetical coding codes a binary character image by means of letters of English alphabet. Directional features find gradient information using Sobel Masks to make position of stroke clear in an image. The features have been derived in eight standard directions and then these eight feature vectors are merged into four sets of features to reduce the system complexity and hence processing time is saved considerably. These features will help develop a Bengali numeral recognition system.
Effects of Curcumin on Squamous Cell Carcinoma of Tongue: An In Vitro Study
Authors: Ardito F. , Perrone D. , Giuliani M. , Testa N.F. , Muzio L. Lo 
Published: April 2018

Background:
The Squamous Cell Carcinoma of the Tongue (TSCC) is the most frequent
cancer of oral cavity often characterized by poor prognosis. Conventional therapies are not very efficient
and often may cause serious side effects. In this context, introduction of natural substances as possible
adjuvant in the treatment and prevention of cancer is becoming a relevant topic. In fact, curcumin has
been used for decades in Chinese traditional medicine for its beneficial effects. Curcumin has anticancer
properties in many tumors however, its action on the tongue carcinoma is not entirely clear and
many other investigations are necessary.

Objective:
Curcumin seems to be a good adjuvant in the treatment of head and neck tumors. However,
these studies are generic and there are not many specific studies on TSCC, the most frequent and most
aggressive cancer of the head-neck region. Our goal is to demonstrate its effectiveness also for TSCC.

Methods:
In this study, we evaluated the effects of curcumin on TSCC cells using different concentrations
(1, 5, 10, 20 and 50 µM) and 3 different treatment times (24, 48 and 72 hours). The inhibition of
adhesion, proliferation, viability, migration and apoptosis was studied.

Results:
IC50 value of curcumin is about 10 µM and there have been inhibitory effects even for treatments
at low concentrations. Curcumin reduces migration and progression of TSCC cells and it promotes
apoptosis and inhibits tumorigenesis.

Conclusions:
These results suggest the possible use of curcumin as an anti-cancer agent in TSCC. However,
in vivo studies are needed to confirm these effects and overcome its low bioavailability.