bluuebunny/crossref_metadata_2025 huggingface dataset:
Competencias básicas y currículum. El caso de Cataluña
Authors: Sarramona I López Jaume
Published: January 2015

El artículo plantea las cuestiones que más habitualmente son objeto de polémica al tratar el tema de las competencias, aunque ya se trata de un concepto ampliamente adoptado en los sistemas educativos. También se propone una clarificación de los distintos calificativos que se otorgan a las competencias, en función de su ámbito de aplicación, así como el análisis de cuál es su aportación real al avance pedagógico.La segunda parte del artículo presenta el caso de Cataluña como una experiencia de integración de las competencias básicas en el currículum, con la novedad de su clara formulación vinculadas a las diversas áreas o materias, así como su propuesta de gradación en tres niveles de consecución.
Una educación proustiana. Pedagogía «more litteratura demonstrata»
Authors: Bárcena Fernando
Published: January 2015

Este artículo trata de responder a una cuestión en apariencia sencilla: ¿puede la literatura, desde el punto de vista, no ya del conocimiento, sino del saber –cuyo fin es transformarnos–, decirnos alguna cosa a los pedagogos, a los teóricos o a los filósofos de la educación? ¿Cabe pensar una pedagogía more litteratura demonstrata? Para ofrecer alguna clase de respuesta a este interrogante, se intenta aquí una reflexión en torno a lo que se llamará una educación proustiana. A partir de una relectura de algunas partes de la À la recherche du temps perdu, de Proust, que se adopta como principal fuente de inspiración, este artículo pretende un ejercicio de filosofía de la educación cuyo motivo principal es pensar la educación como gesto literario.
Metáfora y educación. El poder de la metáfora hortícola en el pensamiento educacional de Célestin Freinet
Authors: Araújo Alberto Filipe
Published: January 2015

El presente artículo intenta entender, en la línea de Daniel Hameline y de Nanine Charbonnel, el porqué de que en educación no se pueda escapar a la presencia y a la función que la metáfora desempeña en el interior, tanto de los textos, como de los discursos educacionales y pedagógicos. En este contexto, el autor del estudio presenta y trabaja la obra educacional de Célestin Freinet (1896-1966) influenciado por los estudios sobre la metáfora de Daniel Hameline, Nanine Charbonnel y de Paul Ricœur. Esto, con el objetivo de hacer entender la pertinencia de la metáfora hortícola en el espacio educacional pedagógico. También intenta reflexionar, en la línea de Paul Ricoeur, si la metáfora, más precisamente la metáfora hortícola, nos plantea la necesidad de una apertura al símbolo, que en el caso específico de la metáfora hortícola sería al simbolismo vegetal y, por consiguiente, habría que tener en cuenta cuáles son las consecuencias pedagógicas de esa metáfora y de la metáfora en sentido amplio.
Heartwood, sapwood and bark variation in coppiced Eucalyptus globulus trees in 2nd rotation and comparison with the single-stem 1st rotation
Authors: Miranda Isabel , Gominho Jorge , Pereira Helena
Published: January 2015

Coppiced trees with 18 years in a 2nd rotation were analysed in relation to heartwood, sapwood and bark content taking into account the effect of the initial planting density by using a spacing trial. A total of 25 stumps, with a variable number of stems per stump from 1 to 3, were analysed. Comparison was made to the previous 1st rotation single stem trees, also harvested at 18 years. In the 2nd rotation, the stump density did not significantly affect stem height and diameter, in opposition to the 1st rotation where spacing significantly impacted on tree dimensions. The effect of the initial planting density is somewhat lost in the coppiced stand in relation with i.e. the number of stems per stump. Heartwood was present in all the coppiced trees up to 49.9% of the total tree height and heartwood volume amounted to 38.9â51.7% of the total tree volume. Within the tree, heartwood content decreased from the base upwards, representing, on average, 54.1% at the base and decreasing to 5.1% at 15.3 m. The sapwood width remained relatively constant with an average radial width of approximately 2 cm. The average stem bark content of coppiced trees was 17.4% of the total stem volume. The comparison of heartwood and sapwood development in the coppiced trees did not show significant differences to the 1st rotation trees, nor did the initial spacing. Heartwood diameter could be modelled using the tree diameter both for 1st and 2nd rotation trees.Eucalyptus globulus
A note on Ricci flow with Ricci curvature bounded below
Authors: Chen Xiuxiong , Yuan Fang
Published: January 2015

In this note, we will prove that given a sequence of Ricci flows

(

M
k

,

g
k

⁢

(
t
)

)

${(M_{k},g_{k}(t))}$

of dimension n,

t
∈

[

-
1

,
0
]

${t\in[-1,0]}$

, with Ricci curvature bounded below uniformly and volume non-collapsing,

(

M
k

,

g
k

⁢

(
0
)

)

${(M_{k},g_{k}(0))}$

converge as a sequence of manifolds to a limit length space

(
X
,
d
)

${(X,d)}$

. The regular part of

(
X
,
d
)

${(X,d)}$

must be open and the convergence is of

C

1
,
α

${C^{1,\alpha}}$

regularity. As a corollary of this result, we prove that in dimension 3, a Ricci flow can always extend unless either its Ricci curvature goes to

-
∞

${-\infty}$

or it shrinks to a point.
Innate immune responses in the brain of sphingolipid lysosomal storage diseases
Authors: Vitner Einat B. , Futerman Anthony H. , Platt Nick
Published: January 2015

Lysosomal storage diseases (LSDs) are mainly caused by the defective activity of lysosomal hydrolases. A sub-class of LSDs are the sphingolipidoses, in which sphingolipids accumulate intra-cellularly. We here discuss the role of innate immunity in the sphingolipidoses, and compare the pathways of activation in two classical sphingolipidoses, namely Gaucher disease and Sandhoff disease, and in Niemann-Pick C disease, in which the main storage material is cholesterol but sphingolipids also accumulate. We discuss the mechanisms leading to neuroinflammation, and the different pathways of neuroinflammation in the different diseases, and suggest that intervention in these pathways may be a useful therapeutic approach to address these devastating human diseases.
Identities arising from higher-order Daehee polynomial bases
Authors: Kim Dae San , Kim Taekyun
Published: January 2015

Here we will derive formulas for expressing any polynomial as linear combinations of two kinds of higherorder
Daehee polynomial basis. Then we will apply these formulas to certain polynomials in order to get new and
interesting identities involving higher-order Daehee polynomials of the first kind and of the second kind.
Exporting the Communist Image: The 1976 Chinese Peasant Painting Exhibition in Britain
Authors: Williams Emily
Published: January 2015

In 1976 an exhibition of Chinese peasant paintings toured Britain. Made by amateur peasant painters from Huxian (户县), the works were widely celebrated in the British art world for their optimistic portrayal of the new socialist countryside. Analysis of the exhibition’s reviews in newspapers and art journals demonstrate, however, that what appealed to the British critics was less the art itself and more the art system in China in which amateurs were encouraged to paint. This was contrasted to a British and Western art world that many left-wing artists and critics deemed to be elitist, overly conceptual and out of touch with the wider public. The success of the Huxian exhibition then needs to be seen in the context of the debates and criticisms of the British art world that took place throughout the 1970s. It also needs to be contextualized within the broader interest in China, Chinese communism and the Cultural Revolution that developed in the late 1960s and 1970s. This essay therefore explores the broader British interest in China in the 1970s and argues that the success of the Huxian peasant painting exhibition was the result of a unique convergence of events in late 1970s Britain.
Rethinking China’s Soft Power
Authors: Houlden Gordon , Schmidt Heather
Published: January 2015

What has been dubbed “China’s rise” has been met with trepidation or outright fear. The increasing economic and political power of the People’s Republic of China (PRC) is often read as a harbinger of the West’s imminent decline, and as a threat to a Western dominated global order. To match its growing ‘hard’ power, leaders in China have outlined intentions to cultivate the country’s soft power, or its appeal and influence globally. These efforts too have been read in largely negative terms in a body of literature that has sprung up around Chinese soft power. Yet, these works tend to assume negative implications without being grounded in empirical research. The contributors to this issue were tasked with reconsidering China’s soft power in the light of research which attends to the ideas and practices of its mediums – mediums such as the expansion of China’s global media network, the opening of Confucius Institutes around the world, and the increasing presence of Chinese popular culture in global forums. This introduction, in particular, considers some of the lessons that considerations of Chinese soft power can learn from the field of global studies.
The effect of the geometry of extrusion head flow channels on the adiabatic extrusion of low density polyethylene
Authors: Sikora Janusz W. , Garbacz Tomasz
Published: January 2015

Plastics extrusion can be divided into the following types: conventional extrusion (run at low speed of the rotating screw), adiabatic extrusion (screw speed is relatively high, yet the process requires the use of heaters) and high speed extrusion (extruder barrel requires cooling due to very high screw speeds). This paper presents the results of a study undertaken to investigate the adiabatic extrusion of low density polyethylene using heads with circular cross-section nozzles and different geometries of flow channels. In the experiments, we examined the temperature and pressure of the polymer in the plasticizing unit, as well as the relationships between the output, thermal power conveyed by the plastic, total power supplied to the extruder, extrusion efficiency, unit consumption of the total energy supplied to the extruder as well as the rotational speed of the screw and the extruder’s head geometry. It was found that the most favorable energy conditions, i.e., the highest efficiency of the adiabatic extrusion of low density polyethylene in the whole range of the tested screw speeds, are ensured when the head with the highest diameter and length nozzle is applied.
Effect of Low Temperature on Tensile Strength and Mode I Fracture Energy of a Room Temperature Vulcanizing Silicone Adhesive
Authors: Marques E. A. S. , Banea M. D. , da Silva Lucas F. M. , Carbas R. J. C. , Sato C.
Published: January 2015

Aerospace applications have an increasing demand for strong and reliable adhesives, able to withstand large temperature gradients. The variation of the adhesive’s mechanical properties with temperature is therefore one of the factors that must be well understood before safe and reliable adhesive joints can be designed for these applications. The stress–strain curve and the toughness properties of an adhesive show strong dependency with temperature for most adhesives, especially near the glass transition temperature (Tg). In this work, an experimental procedure is undertaken to evaluate the effect of low temperatures on the adhesive strength and mode I fracture toughness of a room temperature vulcanizing silicone (RTV) adhesive. Firstly, the temperature at which the glass transition of the RTV occurs was obtained by means of an in-house developed measurement apparatus. Bulk specimens were manufactured and tested at temperatures above and below the Tg in order to obtain a strength envelope of the adhesive over this large temperature range. Single lap joints were also manufactured with this adhesive to assess the behaviour of the adhesive when assembled in a complete joint. For the determination of pure mode I fracture toughness, double cantilever beam specimens were also tested at negative temperatures near Tg. The results showed that the failure loads of all the tests performed have strong temperature dependence and this must be taken into account during adhesive joint design using this type of adhesives.
Experimental Evaluation and Prediction of Formability of Adhesive Bonded Steel Sheets at Different Adhesive Properties
Authors: Satheeshkumar V. , Ganesh Narayanan R.
Published: January 2015

The formability of adhesive bonded steel sheets is experimentally evaluated and predicted with the influence of carbon black (CB) nano powder filled adhesive. The epoxy adhesive properties are modified by filling CB nano powder at different wt. %. The tensile and in-plane plane-strain (IPPS) formability tests are carried out to evaluate the formability of adhesive bonded blanks. The true stress–strain behaviour of adhesive bonded blanks is evaluated from the experimental tests and predicted using a finite element (FE) model. The forming limit strains are evaluated during predictions by necking criteria, namely thickness gradient based necking criterion (TGNC) and effective strain-rate based necking criterion (ESRC), and validated with the experimental limit strains. The results show that the adhesive bonded blanks show improved elongation and limit strains of base materials constituting adhesive bonded blanks with increase in CB up to 2 wt. %. There is a reasonable difference in adhesive bonded sheets limit strains between predictions and experiments due to the absence of interface bonding between adhesive and base materials. In the tensile test, about 9.1 %–21.7 % variation in true major strain and about 10.3 %–13.4 % in true minor strain during TGNC predictions are noticed, while ESRC shows more variation than TGNC. In the IPPS forming test, about 8.3 %–12.4 % difference in true major strain and about 2.2 %–13.4 % difference in true minor strain are noticed during prediction by TGNC. The ESRC predictions are equally efficient as compared to TGNC predictions in this case. The TGNC shows better prediction of about 13.5 % in true major strain, and about 7.5 % in true minor strain as compared to ESRC at different adhesive properties in the tensile test. Similarly, a better prediction of about 1 % in true major strain and about 0.3 % in true minor strain in IPPS formability test is observed.
Subsurface Material Response of Hypo Eutectoid Bearing Steels for Use in Energy Saving Rolling Bearings as a Substitute for Journal Bearings in Combustion Engines
Authors: Sircar Sager Dave , Gegner Jürgen , Lang Karl-Heinz , Poll Gerhard , Joos Rainer
Published: January 2015

The current emphasis on “green” fuel efficient technologies and additional restrictions, such as lead free bearings, have increased the attractiveness of alternative bearing technologies like rolling bearings. A major factor for this development is caused by the circumstance that further decrease of friction and continued reliability of journal bearings increases costs to an intolerable level. Investigations show that a replacement of journal bearings with roller bearings reduces fuel consumption of combustion engines in the range of 2 %–5 %. Due to limitations in the processing of 100Cr6 bearing steel (SAE 52100), however, induction hardend hypo eutectoid bearing steel attract notice. No publicly accessible data for service life rating is available for these steel grades. To determine the service life limiting effects for these grades, tests are conducted and, due to exclusively tribological failures, a material response approach is taken to determine the subsurface failure. Presently, applications with strong and repeated impact loads, such as combustion engines, have seen the widespread use of journal bearings for about a century. Especially in the case of combustion engines, long periods of next to no load are interrupted by periods of strong loads. Moreover, in the case of combustion engines, some bearings experience rapid changes of the direction of force while the maximum load is being applied. The long-time effects like a friction increase because wear and material responses are not thoroughly investigated at present. The current work proposes a novel method to test the long-time behaviour of rolling bearings at very high impact loads. The method is realised by a test bench specifically designed to create reproducible impact loads on rotating bearings. Special care has been taken to ensure the impact loads are being induced at the same spot over an average run time of 5 × 108 revolutions. During a test run, vibration, torque, grease and lubrication temperature are being monitored and controlled.
A Hybrid Optico-Acoustic NDE Approach for Deformation and Damage Monitoring
Authors: Cuadra Jefferson , Vanniamparambil Prashanth A. , Hazeli Kavan , Bartoli I. , Kontsos Antonios
Published: January 2015

To account for both surface and volume effects and to provide cross-validation when using in situ nondestructive evaluation (NDE) methods, a hybrid optico-acoustic approach combining digital image correlation (DIC) and acoustic emission (AE) was developed, validated, and tested. The designed system includes hardware and software linkages between the two sensing modalities with feedback both from the mechanical testing device as well as from other complementary NDE methods including ultrasonic testing (UT) and infrared thermography (IRT). This hybrid monitoring approach targets the early identification of damage precursors which vary depending on the material tested. To corroborate the reliability of the hybrid setup, various tensile, fracture and fatigue testing procedures were implemented for different types of materials. Of interest herein was the evaluation of each individual NDE method’s monitoring capabilities of deformation and damage in conjunction with their spatial and temporal resolutions. In carefully designed metal alloy microstructures with well-characterized mechanical properties, AE validated DIC-observed strain band formations on the sample’s surface, which further enabled targeted microscopic analyses that proved the origin of the NDE findings. In the case of fracture, DIC and UT validated AE information regarding both crack initiation and growth in Mode I testing of metallic alloy samples. Finally, in fatigue loading of fiber reinforced composites, IR measurements confirmed DIC indications of early damage formation consistent with AE recordings. Post-processing of NDE datasets combined with actual loading information allowed the calculation of mechanical parameters (elastic–plastic transition stress, strain localizations, traction separation laws, energy dissipation, localized Poisson ratios) that have been used to construct physics-based computational models for multi-scale deformation and damage evolution, as well as remaining life-estimations.
Oligodendroglial Maturation Is Dependent on Intracellular Protein Shuttling
Authors: Göttle Peter , Sabo Jennifer K. , Heinen André , Venables Gene , Torres Klintsy , Tzekova Nevena , Parras Carlos M. , Kremer David , Hartung Hans-Peter , Cate Holly S. , Küry Patrick
Published: January 2015

Multiple sclerosis is an autoimmune disease of the CNS resulting in degeneration of myelin sheaths and loss of oligodendrocytes, which means that protection and electrical insulation of axons and rapid signal propagation are impaired, leading to axonal damage and permanent disabilities. Partial replacement of lost oligodendrocytes and remyelination can occur as a result of activation and recruitment of resident oligodendroglial precursor cells. However, the overall remyelination capacity remains inefficient because precursor cells often fail to generate new oligodendrocytes. Increasing evidence points to the existence of several molecular inhibitors that act on these cells and interfere with their cellular maturation. Thep57kip2gene encodes one such potent inhibitor of oligodendroglial differentiation and this study sheds light on the underlying mode of action. We found that subcellular distribution of the p57kip2 protein changed during differentiation of rat, mouse, and human oligodendroglial cells bothin vivoandin vitro. Nuclear export of p57kip2 was correlated with promoted myelin expression, higher morphological phenotypes, and enhanced myelinationin vitro. In contrast, nuclear accumulation of p57kip2 resulted in blocked oligodendroglial differentiation. Experimental evidence suggests that the inhibitory role of p57kip2 depends on specific interactions with binding proteins such as LIMK-1, CDK2, Mash1, and Hes5 either by controlling their site of action or their activity. Because functional restoration in demyelinating diseases critically depends on the successful generation of oligodendroglial cells, a therapeutic need that is currently unmet, the regulatory mechanism described here might be of particular interest for identifying suitable drug targets and devising novel therapeutic approaches.
Neural Dynamics Underlying Attentional Orienting to Auditory Representations in Short-Term Memory
Authors: Backer Kristina C. , Binns Malcolm A. , Alain Claude
Published: January 2015

Sounds are ephemeral. Thus, coherent auditory perception depends on “hearing” back in time: retrospectively attending that which was lost externally but preserved in short-term memory (STM). Current theories of auditory attention assume that sound features are integrated into a perceptual object, that multiple objects can coexist in STM, and that attention can be deployed to an object in STM. Recording electroencephalography from humans, we tested these assumptions, elucidating feature-general and feature-specific neural correlates of auditory attention to STM. Alpha/beta oscillations and frontal and posterior event-related potentials indexed feature-general top-down attentional control to one of several coexisting auditory representations in STM. Particularly, task performance during attentional orienting was correlated with alpha/low-beta desynchronization (i.e., power suppression). However, attention to one feature could occur without simultaneous processing of the second feature of the representation. Therefore, auditory attention to memory relies on both feature-specific and feature-general neural dynamics.
Stimulation of Monocytes, Macrophages, and Microglia by Amphotericin B and Macrophage Colony-Stimulating Factor Promotes Remyelination
Authors: Döring Axinia , Sloka Scott , Lau Lorraine , Mishra Manoj , van Minnen Jan , Zhang Xu , Kinniburgh David , Rivest Serge , Yong V. Wee
Published: January 2015

Approaches to stimulate remyelination may lead to recovery from demyelinating injuries and protect axons. One such strategy is the activation of immune cells with clinically used medications, since a properly directed inflammatory response can have healing properties through mechanisms such as the provision of growth factors and the removal of cellular debris. We previously reported that the antifungal medication amphotericin B is an activator of circulating monocytes, and their tissue-infiltrated counterparts and macrophages, and of microglia within the CNS. Here, we describe that amphotericin B activates these cells through engaging MyD88/TRIF signaling. When mice were subjected to lysolecithin-induced demyelination of the spinal cord, systemic injections of nontoxic doses of amphotericin B and another activator, macrophage colony-stimulating factor (MCSF), further elevated the representation of microglia/macrophages at the site of injury. Treatment with amphotericin B, particularly in combination with MCSF, increased the number of oligodendrocyte precursor cells and promoted remyelination within lesions; these pro-regenerative effects were mitigated in mice treated with clodronate liposomes to reduce circulating monocytes and tissue-infiltrated macrophages. Our results have identified candidates among currently used medications as potential therapies for the repair of myelin.
Audition-Independent Vocal Crystallization Associated with Intrinsic Developmental Gene Expression Dynamics
Authors: Mori Chihiro , Wada Kazuhiro
Published: January 2015

Complex learned behavior is influenced throughout development by both genetic and environmental factors. Birdsong, like human speech, is a complex vocal behavior acquired through sensorimotor learning and is based on coordinated auditory input and vocal output to mimic tutor song. Song is primarily learned during a specific developmental stage called the critical period. Although auditory input is crucial for acquiring complex vocal patterns, its exact role in neural circuit maturation for vocal learning and production is not well understood. Using audition-deprived songbirds, we examined whether auditory experience affects developmental gene expression in the major elements of neural circuits that mediate vocal learning and production. Compared with intact zebra finches, early-deafened zebra finches showed excessively delayed vocal development, but their songs eventually crystallized. In contrast to the different rates of song development between the intact and deafened birds, developmental gene expression in the motor circuit is conserved in an age-dependent manner from the juvenile stage until the older adult stage, even in the deafened birds, which indicates the audition-independent robustness of gene expression dynamics during development. Furthermore, even after adult deafening, which degrades crystallized song, the deteriorated songs ultimately restabilized at the same point when the early-deafened birds stabilized their songs. These results indicate a genetic program-associated inevitable termination of vocal plasticity that results in audition-independent vocal crystallization.
The Full-Length Form of theDrosophilaAmyloid Precursor Protein Is Involved in Memory Formation
Authors: Bourdet Isabelle , Preat Thomas , Goguel Valérie
Published: January 2015

The APP plays a central role in AD, a pathology that first manifests as a memory decline. Understanding the role of APP in normal cognition is fundamental in understanding the progression of AD, and mammalian studies have pointed to a role of secreted APPα in memory. InDrosophila, we recently showed that APPL, the fly APP ortholog, is required for associative memory. In the present study, we aimed to characterize which form of APPL is involved in this process. We show that expression of a secreted-APPL form in the mushroom bodies, the center for olfactory memory, is able to rescue the memory deficit caused by APPL partial loss of function. We next assessed the impact on memory of theDrosophilaα-secretasekuzbanian(KUZ), the enzyme initiating the nonamyloidogenic pathway that produces secreted APPLα. Strikingly, KUZ overexpression not only failed to rescue the memory deficit caused by APPL loss of function, it exacerbated this deficit. We further show that in addition to an increase in secreted-APPL forms, KUZ overexpression caused a decrease of membrane-bound full-length species that could explain the memory deficit. Indeed, we observed that transient expression of a constitutive membrane-bound mutant APPL form is sufficient to rescue the memory deficit caused by APPL reduction, revealing for the first time a role of full-length APPL in memory formation. Our data demonstrate that, in addition to secreted APPL, the noncleaved form is involved in memory, raising the possibility that secreted and full-length APPL act together in memory processes.
HDAC2 Selectively Regulates FOXO3a-Mediated Gene Transcription during Oxidative Stress-Induced Neuronal Cell Death
Authors: Peng Shengyi , Zhao Siqi , Yan Feng , Cheng Jinbo , Huang Li , Chen Hong , Liu Qingsong , Ji Xunming , Yuan Zengqiang
Published: January 2015

All neurodegenerative diseases are associated with oxidative stress-induced neuronal death. Forkhead box O3a (FOXO3a) is a key transcription factor involved in neuronal apoptosis. However, how FOXO3a forms complexes and functions in oxidative stress processing remains largely unknown. In the present study, we show that histone deacetylase 2 (HDAC2) forms a physical complex with FOXO3a, which plays an important role in FOXO3a-dependent gene transcription and oxidative stress-induced mouse cerebellar granule neuron (CGN) apoptosis. Interestingly, we also found that HDAC2 became selectively enriched in the promoter region of thep21gene, but not those of other target genes, and inhibited FOXO3a-mediatedp21transcription. Furthermore, we found that oxidative stress reduced the interaction between FOXO3a and HDAC2, leading to an increased histone H4K16 acetylation level in thep21promoter region and upregulated p21 expression in a manner independent of p53 or E2F1. Phosphorylation of HDAC2 at Ser 394 is important for the HDAC2–FOXO3a interaction, and we found that cerebral ischemia/reperfusion reduced phosphorylation of HDAC2 at Ser 394 and mitigated the HDAC2–FOXO3a interaction in mouse brain tissue. Our study reveals the novel regulation of FOXO3a-mediated selective gene transcription via epigenetic modification in the process of oxidative stress-induced cell death, which could be exploited therapeutically.
Cerebellar Cortex and Cerebellar Nuclei Are Concomitantly Activated during Eyeblink Conditioning: A 7T fMRI Study in Humans
Authors: Thürling Markus , Kahl Fabian , Maderwald Stefan , Stefanescu Roxana M. , Schlamann Marc , Boele Henk-Jan , De Zeeuw Chris I. , Diedrichsen Jörn , Ladd Mark E. , Koekkoek Sebastiaan K. E. , Timmann Dagmar
Published: January 2015

There are controversies whether learning of conditioned eyeblink responses primarily takes place within the cerebellar cortex, the interposed nuclei, or both. It has also been suggested that the cerebellar cortex may be important during early stages of learning, and that there is a shift to the cerebellar nuclei during later stages. As yet, human studies have provided little to resolve this question. In the present study, we established a setup that allows ultra-high-field 7T functional magnetic resonance imaging (fMRI) of the cerebellar cortex and interposed cerebellar nuclei simultaneously during delay eyeblink conditioning in humans. Event-related fMRI signals increased concomitantly in the cerebellar cortex and nuclei during early acquisition of conditioned eyeblink responses in 20 healthy human subjects. ANOVAs with repeated-measures showed significant effects of time across five blocks of 20 conditioning trials in the cortex and nuclei (p< 0.05, permutation corrected). Activations were most pronounced in, but not limited to, lobules VI and interposed nuclei. Increased activations were most prominent at the first time the maximum number of conditioned responses was achieved. Our data are consistent with a simultaneous and synergistic two-site model of learning during acquisition of classically conditioned eyeblinks. Because increased MRI signal reflects synaptic activity, concomitantly increased signals in the cerebellar nuclei and cortex are consistent with findings of learning related potentiation at the mossy fiber to nuclear cell synapse and mossy fiber to granule cell synapse. Activity related to the expression of conditioned responses, however, cannot be excluded.
Functional Mapping of Face-Selective Regions in the Extrastriate Visual Cortex of the Marmoset
Authors: Hung Chia-Chun , Yen Cecil C. , Ciuchta Jennifer L. , Papoti Daniel , Bock Nicholas A. , Leopold David A. , Silva Afonso C.
Published: January 2015

The cerebral cortex of humans and macaques has specialized regions for processing faces and other visual stimulus categories. It is unknown whether a similar functional organization exists in New World monkeys, such as the common marmoset (Callithrix jacchus), a species of growing interest as a primate model in neuroscience. To address this question, we measured selective neural responses in the brain of four awake marmosets trained to fix their gaze upon images of faces, bodies, objects, and control patterns. In two of the subjects, we measured high gamma-range field potentials from electrocorticography arrays implanted over a large portion of the occipital and inferotemporal cortex. In the other two subjects, we measured BOLD fMRI responses across the entire brain. Both techniques revealed robust, regionally specific patterns of category-selective neural responses. We report that at least six face-selective patches mark the occipitotemporal pathway of the marmoset, with the most anterior patches showing the strongest preference for faces over other stimuli. The similar appearance of these patches to previous findings in macaques and humans, including their apparent arrangement in two parallel pathways, suggests that core elements of the face processing network were present in the common anthropoid primate ancestor living ∼35 million years ago. The findings also identify the marmoset as a viable animal model system for studying specialized neural mechanisms related to high-level social visual perception in humans.
NLP-12 Engages Different UNC-13 Proteins to Potentiate Tonic and Evoked Release
Authors: Hu Zhitao , Vashlishan-Murray Amy B. , Kaplan Joshua M.
Published: January 2015

A neuropeptide (NLP-12) and its receptor (CKR-2) potentiate tonic and evoked ACh release atCaenorhabditis elegansneuromuscular junctions. Increased evoked release is mediated by a presynaptic pathway (egl-30Gαqandegl-8PLCβ) that produces DAG, and by DAG binding to short and long UNC-13 proteins. Potentiation of tonic ACh release persists in mutants deficient foregl-30Gαqandegl-8PLCβ and requires DAG binding to UNC-13L (but not UNC-13S). Thus, NLP-12 adjusts tonic and evoked release by distinct mechanisms.
Patterned, But Not Tonic, Optogenetic Stimulation in Motor Thalamus Improves Reaching in Acute Drug-Induced Parkinsonian Rats
Authors: Seeger-Armbruster Sonja , Bosch-Bouju Clémentine , Little Shane T.C. , Smither Roseanna A. , Hughes Stephanie M. , Hyland Brian I. , Parr-Brownlie Louise C.
Published: January 2015

High-frequency deep brain stimulation (DBS) in motor thalamus (Mthal) ameliorates tremor but not akinesia in Parkinson's disease. The aim of this study was to investigate whether there are effective methods of Mthal stimulation to treat akinesia. Glutamatergic Mthal neurons, transduced with channelrhodopsin-2 by injection of lentiviral vector (Lenti.CaMKII.hChR2(H134R).mCherry), were selectively stimulated with blue light (473 nm) via a chronically implanted fiber-optic probe. Rats performed a reach-to-grasp task in either acute drug-induced parkinsonian akinesia (0.03–0.07 mg/kg haloperidol, s.c.) or control (vehicle injection) conditions, and the number of reaches was recorded for 5 min before, during, and after stimulation. We compared the effect of DBS using complex physiological patterns previously recorded in the Mthal of a control rat during reaching or exploring behavior, with tonic DBS delivering the same number of stimuli per second (rate-control 6.2 or 1.8 Hz, respectively) and with stimulation patterns commonly used in other brain regions to treat neurological conditions (tonic 130 Hz, theta burst (TBS), and tonic 15 Hz rate-control for TBS). Control rats typically executed >150 reaches per 5 min, which was unaffected by any of the stimulation patterns. Acute parkinsonian rats executed <20 reaches, displaying marked akinesia, which was significantly improved by stimulating with the physiological reaching pattern or TBS (bothp< 0.05), whereas the exploring and all tonic patterns failed to improve reaching. Data indicate that the Mthal may be an effective site to treat akinesia, but the pattern of stimulation is critical for improving reaching in parkinsonian rats.
Desynchronization of Fast-Spiking Interneurons Reduces β-Band Oscillations and Imbalance in Firing in the Dopamine-Depleted Striatum
Authors: Damodaran Sriraman , Cressman John R. , Jedrzejewski-Szmek Zbigniew , Blackwell Kim T.
Published: January 2015

Oscillations in the β-band (8–30 Hz) that emerge in the output nuclei of the basal ganglia during Parkinson's disease, along with an imbalanced activation of the direct and indirect pathways, have been linked to the hypokinetic motor output associated with the disease. Although dopamine depletion causes a change in cellular and network properties in the striatum, it is unclear whether abnormal activity measured in the globus pallidus and substantia nigra pars reticulata is caused by abnormal striatal activity. Here we use a computational network model of medium spiny neurons (MSNs)—fast-spiking interneurons (FSIs), based on data from several mammalian species, and find that robust β-band oscillations and imbalanced firing emerge from implementation of changes to cellular and circuit properties caused by dopamine depletion. These changes include a reduction in connections between MSNs, a doubling of FSI inhibition to D2MSNs, an increase in D2MSN dendritic excitability, and a reduction in D2MSN somatic excitability. The model reveals that the reduced decorrelation between MSNs attributable to weakened lateral inhibition enables the strong influence of synchronous FSIs on MSN firing and oscillations. Weakened lateral inhibition also produces an increased sensitivity of MSN output to cortical correlation, a condition relevant to the parkinsonian striatum. The oscillations of FSIs, in turn, are strongly modulated by fast electrical transmission between FSIs through gap junctions. These results suggest that pharmaceuticals that desynchronize FSI activity may provide a novel treatment for the enhanced β-band oscillations, imbalanced firing, and motor dysfunction in Parkinson's disease.
Decoding a Wide Range of Hand Configurations from Macaque Motor, Premotor, and Parietal Cortices
Authors: Schaffelhofer Stefan , Agudelo-Toro Andres , Scherberger Hansjörg
Published: January 2015

Despite recent advances in decoding cortical activity for motor control, the development of hand prosthetics remains a major challenge. To reduce the complexity of such applications, higher cortical areas that also represent motor plans rather than just the individual movements might be advantageous. We investigated the decoding of many grip types using spiking activity from the anterior intraparietal (AIP), ventral premotor (F5), and primary motor (M1) cortices. Two rhesus monkeys were trained to grasp 50 objects in a delayed task while hand kinematics and spiking activity from six implanted electrode arrays (total of 192 electrodes) were recorded. Offline, we determined 20 grip types from the kinematic data and decoded these hand configurations and the grasped objects with a simple Bayesian classifier. When decoding from AIP, F5, and M1 combined, the mean accuracy was 50% (using planning activity) and 62% (during motor execution) for predicting the 50 objects (chance level, 2%) and substantially larger when predicting the 20 grip types (planning, 74%; execution, 86%; chance level, 5%). When decoding from individual arrays, objects and grip types could be predicted well during movement planning from AIP (medial array) and F5 (lateral array), whereas M1 predictions were poor. In contrast, predictions during movement execution were best from M1, whereas F5 performed only slightly worse. These results demonstrate for the first time that a large number of grip types can be decoded from higher cortical areas during movement preparation and execution, which could be relevant for future neuroprosthetic devices that decode motor plans.
Interplay of Inhibition and Excitation Shapes a Premotor Neural Sequence
Authors: Kosche Georg , Vallentin Daniela , Long Michael A.
Published: January 2015

In the zebra finch, singing behavior is driven by a sequence of bursts within premotor neurons located in the forebrain nucleus HVC (proper name). In addition to these excitatory projection neurons, HVC also contains inhibitory interneurons with a role in premotor patterning that is unclear. Here, we used a range of electrophysiological and behavioral observations to test previously described models suggesting discrete functional roles for inhibitory interneurons in song production. We show that single HVC premotor neuron bursts are sufficient to drive structured activity within the interneuron network because of pervasive and facilitating synaptic connections. We characterize interneuron activity during singing and describe reliable pauses in the firing of those neurons. We then demonstrate that these gaps in inhibition are likely to be necessary for driving normal bursting behavior in HVC premotor neurons and suggest that structured inhibition and excitation may be a general mechanism enabling sequence generation in other circuits.
Identification of Nonviable Genes Affecting Touch Sensitivity inCaenorhabditis elegansUsing Neuronally Enhanced Feeding RNA Interference
Authors: Chen Xiaoyin , Cuadros Margarete Diaz , Chalfie Martin
Published: January 2015

Caenorhabditis elegans senses gentle touch along the body via six touch receptor neurons. Although genetic screens and microarray analyses have identified several genes needed for touch sensitivity, these methods miss pleiotropic genes that are essential for the viability, movement, or fertility of the animals. We used neuronally enhanced feeding RNA interference to screen genes that cause lethality or paralysis when mutated, and we identified 61 such genes affecting touch sensitivity, including five positive controls. We confirmed 18 genes by using available alleles, and further studied one of them, tag-170, now renamed txdc-9. txdc-9 preferentially affects anterior touch response but is needed for tubulin acetylation and microtubule formation in both the anterior and posterior touch receptor neurons. Our results indicate that neuronally enhanced feeding RNA interference screens complement traditional mutageneses by identifying additional nonviable genes needed for specific neuronal functions.
Rapid and Inexpensive Whole-Genome Genotyping-by-Sequencing for Crossover Localization and Fine-Scale Genetic Mapping
Authors: Rowan Beth A , Patel Vipul , Weigel Detlef , Schneeberger Korbinian
Published: January 2015

The reshuffling of existing genetic variation during meiosis is important both during evolution and in breeding. The reassortment of genetic variants relies on the formation of crossovers (COs) between homologous chromosomes. The pattern of genome-wide CO distributions can be rapidly and precisely established by the short-read sequencing of individuals from F2 populations, which in turn are useful for quantitative trait locus (QTL) mapping. Although sequencing costs have decreased precipitously in recent years, the costs of library preparation for hundreds of individuals have remained high. To enable rapid and inexpensive CO detection and QTL mapping using low-coverage whole-genome sequencing of large mapping populations, we have developed a new method for library preparation along with Trained Individual GenomE Reconstruction, a probabilistic method for genotype and CO predictions for recombinant individuals. In an example case with hundreds of F2 individuals from two Arabidopsis thaliana accessions, we resolved most CO breakpoints to within 2 kb and reduced a major flowering time QTL to a 9-kb interval. In addition, an extended region of unusually low recombination revealed a 1.8-Mb inversion polymorphism on the long arm of chromosome 4. We observed no significant differences in the frequency and distribution of COs between F2 individuals with and without a functional copy of the DNA helicase gene RECQ4A. In summary, we present a new, cost-efficient method for large-scale, high-precision genotyping-by-sequencing.
Organizational justice and insomnia: Relationships between justice components and insomnia symptoms among private company workers in Japan
Authors: Hayashi Toshio , Odagiri Yuko , Takamiya Tomoko , Ohya Yumiko , Inoue Shigeru
Published: January 2015

Organizational justice and insomnia: Relationships between justice components and insomnia symptoms among private company workers in Japan: Toshio Hayashi, et al. Department of Preventive Medicine and Public Health, Tokyo Medical University

Objective

Organizational justice (OJ) is an important psychosocial factor and it consists of several components. Previous studies have shown that low perceived OJ is associated with various health problems. However, the relationships between each justice component and health outcomes have not been fully examined. The purpose of this study was to clarify the relationships between OJ and insomnia, including OJ components and insomnia symptoms.

Methods

Cross‐sectional self‐reported questionnaire data from 1,893 employees (92.2% of subjects) were collected. OJ was measured using the Japanese version of the OJ questionnaire, which has four components (distributive, procedural, interpersonal and informational). Insomnia was assessed with the Athens Insomnia Scale. Logistic regression analysis, with insomnia as a dependent variable and OJ as an independent variable, was conducted.

Results

Subjects with low overall OJ had a higher risk of insomnia (adjusted odds ratio (AOR), 2.37; 95% confidence interval (CI), 1.59 to 3.53) and two insomnia symptoms (AOR of 2.47 and 95% CI of 1.68 to 3.65 for sleep induction problem; AOR of 1.73 and 95% CI of 1.21 to 2.48 for sleep maintenance problem). The four justice components were all associated with insomnia and sleep induction problems. Sleep maintenance problems were associated with only the distributive justice component.

Conclusions

All four justice components were associated with both insomnia and sleep induction problems. Sleep maintenance problems, however, showed different features. Specifically, the distributive justice component seemed to be a key factor in the relationship between OJ and insomnia. These findings might provide useful information for preventing the adverse effects of insomnia.
Marrow hypoplasia: a rare complication of untreated Grave’s disease
Authors: Garcia Juliana , França Larissa de , Ellinger Vivian , Wolff Mônica
Published: January 2015

Atypical presentation forms of hyperthyroidism are always a challenge to the clinician. We present a female patient with the typical symptoms of thyrotoxicosis, without any thionamides treatment before, associated with pancytopenia, which recovered after euthyroidism state was achieved. Although the major cases of pancytopenia in Grave’s disease are seen as a complication of antithyroid drugs (thioamides), in this case report the alteration in blood tests was associated with untreated hyperthyroidism. In the literature review, we found 19 case reports between 1981 to 2012, but it has been related to a hypercellular bone marrow with periferic destruction. Our case, however, is about a hypocellular bone marrow without fibrosis or fat tissue replacement, which proceeded with a periferic improvement following thyroid treatment. Although rare, pancytopenia, when present, may develop as an unusual and severe manifestation in untreated subjects.
Bariatric surgery – An update for the endocrinologist
Authors: Mancini Marcio C.
Published: January 2015

Obesity is a major public health problem, is associated with increased rates of mortality risk and of developing several comorbidities, and lessens life expectancy. Bariatric surgery is the most effective treatment for morbidly obese patients, reducing risk of developing new comorbidities, health care utilization and mortality. The establishment of centers of excellence with interdisciplinary staff in bariatric surgery has been reducing operative mortality in the course of time, improving surgical safety and quality. The endocrinologist is part of the interdisciplinary team. The aim of this review is to provide endocrinologists, physicians and health care providers crucial elements of good clinical practice in the management of morbidly obese bariatric surgical candidates. This information includes formal indications and contraindications for bariatric operations, description of usual bariatric and metabolic operations as well as endoscopic treatments, preoperative assessments including psychological, metabolic and cardiorespiratory evaluation and postoperative dietary staged meal progression and nutritional supplementation follow-up with micronutrient deficiencies monitoring, surgical complications, suspension of medications in type 2 diabetic patients, dumping syndrome and hypoglycemia. Arq Bras Endocrinol Metab. 2014;58(9):875-88