Prolonged plasticity: Necessary and sufficient for language-ready brains

2008 ◽  
Vol 31 (5) ◽  
pp. 514-515 ◽  
Author(s):  
Patricia J. Brooks ◽  
Sonia Ragir
Keyword(s):  
Social Development ◽  
Social Groups ◽  
Postnatal Growth ◽  
Fine Tuning ◽  
Shared Meaning ◽  
Neural Connections ◽  
Wide Range ◽  
Necessary And Sufficient ◽  
Communal Exchange ◽  
Activity Dependent

AbstractLanguages emerge in response to the negotiation of shared meaning in social groups, where transparency of grammar is necessitated by demands of communication with relative strangers needing to consult on a wide range of topics (Ragir 2002). This communal exchange is automated and stabilized through activity-dependent fine-tuning of information-specific neural connections during postnatal growth and social development.

Harnessing methylation and AdoMet-utilising enzymes for selective modification in cascade reactions

2021 ◽  
Author(s):  
Freideriki Michailidou ◽  
Andrea Rentmeister
Keyword(s):  
Natural Products ◽  
Small Molecules ◽  
Cascade Reactions ◽  
Fine Tuning ◽  
Wide Range

Enzyme-mediated methylation is a very important reaction in nature, yielding a wide range of modified natural products, diversifying small molecules and fine-tuning the activity of biomacromolecules. The field has attracted...

scholarly journals Suppressing meta-holographic artifacts by laser coherence tuning

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yaniv Eliezer ◽  
Geyang Qu ◽  
Wenhong Yang ◽  
Yujie Wang ◽  
Hasan Yılmaz ◽  
...  
Keyword(s):  
Spatial Coherence ◽  
Fine Tuning ◽  
Total Power ◽  
Image Sharpness ◽  
Continuous Tuning ◽  
Fine Spatial Resolution ◽  
Compact Size ◽  
Wide Range ◽  
Fabrication Defects ◽  
Holographic Displays

AbstractA metasurface hologram combines fine spatial resolution and large viewing angles with a planar form factor and compact size. However, it suffers coherent artifacts originating from electromagnetic cross-talk between closely packed meta-atoms and fabrication defects of nanoscale features. Here, we introduce an efficient method to suppress all artifacts by fine-tuning the spatial coherence of illumination. Our method is implemented with a degenerate cavity laser, which allows a precise and continuous tuning of the spatial coherence over a wide range, with little variation in the emission spectrum and total power. We find the optimal degree of spatial coherence to suppress the coherent artifacts of a meta-hologram while maintaining the image sharpness. This work paves the way to compact and dynamical holographic displays free of coherent defects.

scholarly journals AMPA receptor inhibition by synaptically released zinc

2015 ◽  
Vol 112 (51) ◽  
pp. 15749-15754 ◽  
Author(s):  
Bopanna I. Kalappa ◽  
Charles T. Anderson ◽  
Jacob M. Goldberg ◽  
Stephen J. Lippard ◽  
Thanos Tzounopoulos
Keyword(s):  
Dorsal Cochlear Nucleus ◽  
Fine Tuning ◽  
Receptor Inhibition ◽  
Endogenous Modulator ◽  
Excitatory Neurotransmission ◽  
Zinc Levels ◽  
Zinc Inhibition ◽  
Endogenous Modulators ◽  
Activity Dependent

The vast amount of fast excitatory neurotransmission in the mammalian central nervous system is mediated by AMPA-subtype glutamate receptors (AMPARs). As a result, AMPAR-mediated synaptic transmission is implicated in nearly all aspects of brain development, function, and plasticity. Despite the central role of AMPARs in neurobiology, the fine-tuning of synaptic AMPA responses by endogenous modulators remains poorly understood. Here we provide evidence that endogenous zinc, released by single presynaptic action potentials, inhibits synaptic AMPA currents in the dorsal cochlear nucleus (DCN) and hippocampus. Exposure to loud sound reduces presynaptic zinc levels in the DCN and abolishes zinc inhibition, implicating zinc in experience-dependent AMPAR synaptic plasticity. Our results establish zinc as an activity-dependent, endogenous modulator of AMPARs that tunes fast excitatory neurotransmission and plasticity in glutamatergic synapses.

Alkene Difunctionalization Directed by Free Amines: Diamine Synthesis via Nickel-Catalyzed 1,2-Carboamination

2021 ◽  
Author(s):  
Taeho Kang ◽  
José Manuel González ◽  
Zi-Qi Li ◽  
Klement Foo ◽  
Peter Cheng ◽  
...  
Keyword(s):  
Nickel Catalyst ◽  
Room Temperature ◽  
Kinetic Studies ◽  
Fine Tuning ◽  
Secondary Amines ◽  
Protecting Group ◽  
Wide Range ◽  
Leaving Group ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

A versatile method to access differentially substituted 1,3- and 1,4-diamines via a nickel-catalyzed three-component 1,2-carboamination of alkenyl amines with aryl/alkenylboronic ester nucleophiles and N–O electrophiles is reported. The reaction proceeds efficiently with free primary and secondary amines without needing a directing auxiliary or protecting group, and is enabled by fine-tuning the leaving group on the N–O reagent. The transformation is highly regioselective and compatible with a wide range of coupling partners and alkenyl amine substrates, all performed at room temperature. A series of kinetic studies support a mechanism in which alkene coordination to the nickel catalyst is turnover-limiting.

Fitting Frequency-Lowering Signal Processing Applying the American Academy of Audiology Pediatric Amplification Guideline: Updates and Protocols

2016 ◽  
Vol 27 (03) ◽  
pp. 219-236 ◽  
Author(s):  
Susan Scollie ◽  
Danielle Glista ◽  
Julie Seto ◽  
Andrea Dunn ◽  
Brittany Schuett ◽  
...  
Keyword(s):  
Signal Processing ◽  
Frequency Response ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Fine Tuning ◽  
Sensation Level ◽  
Response Level ◽  
Strong Basis ◽  
Wide Range ◽  
Signal Processors

Background: Although guidelines for fitting hearing aids for children are well developed and have strong basis in evidence, specific protocols for fitting and verifying technologies can supplement such guidelines. One such technology is frequency-lowering signal processing. Children require access to a broad bandwidth of speech to detect and use all phonemes including female /s/. When access through conventional amplification is not possible, the use of frequency-lowering signal processing may be considered as a means to overcome limitations. Fitting and verification protocols are needed to better define candidacy determination and options for assessing and fine tuning frequency-lowering signal processing for individuals. Purpose: This work aims to (1) describe a set of calibrated phonemes that can be used to characterize the variation in different brands of frequency-lowering processors in hearing aids and the verification with these signals and (2) determine whether verification with these signal are predictive of perceptual changes associated with changes in the strength of frequency-lowering signal processing. Finally, we aimed to develop a fitting protocol for use in pediatric clinical practice. Study Sample: Study 1 used a sample of six hearing aids spanning four types of frequency lowering algorithms for an electroacoustic evaluation. Study 2 included 21 adults who had hearing loss (mean age 66 yr). Data Collection and Analysis: Simulated fricatives were designed to mimic the level and frequency shape of female fricatives extracted from two sources of speech. These signals were used to verify the frequency-lowering effects of four distinct types of frequency-lowering signal processors available in commercial hearing aids, and verification measures were compared to extracted fricatives made in a reference system. In a second study, the simulated fricatives were used within a probe microphone measurement system to verify a wide range of frequency compression settings in a commercial hearing aid, and 27 adult listeners were tested at each setting. The relation between the hearing aid verification measures and the listener’s ability to detect and discriminate between fricatives was examined. Results: Verification measures made with the simulated fricatives agreed to within 4 dB, on average, and tended to mimic the frequency response shape of fricatives presented in a running speech context. Some processors showed a greater aided response level for fricatives in running speech than fricatives presented in isolation. Results with listeners indicated that verified settings that provided a positive sensation level of /s/ and that maximized the frequency difference between /s/ and /∫/ tended to have the best performance. Conclusions: Frequency-lowering signal processors have measureable effects on the high-frequency fricative content of speech, particularly female /s/. It is possible to measure these effects either with a simple strategy that presents an isolated simulated fricative and measures the aided frequency response or with a more complex system that extracts fricatives from running speech. For some processors, a more accurate result may be achieved with a running speech system. In listeners, the aided frequency location and sensation level of fricatives may be helpful in predicting whether a specific hearing aid fitting, with or without frequency-lowering, will support access to the fricatives of speech.

scholarly journals Coupling of L-Type Ca2+ Channels to KV7/KCNQ Channels Creates a Novel, Activity-Dependent, Homeostatic Intrinsic Plasticity

2008 ◽  
Vol 100 (4) ◽  
pp. 1897-1908 ◽  
Author(s):  
Wendy W. Wu ◽  
C. Savio Chan ◽  
D. James Surmeier ◽  
John F. Disterhoft
Keyword(s):  
Pyramidal Neurons ◽  
Firing Frequency ◽  
Fine Tuning ◽  
Membrane Excitability ◽  
Kcnq Channels ◽  
Central Neurons ◽  
Subsequent Activation ◽  
Intrinsic Plasticity ◽  
Dependent Modification ◽  
Activity Dependent

Experience-dependent modification in the electrical properties of central neurons is a form of intrinsic plasticity that occurs during development and has been observed following behavioral learning. We report a novel form of intrinsic plasticity in hippocampal CA1 pyramidal neurons mediated by the KV7/KCNQ and CaV1/L-type Ca2+ channels. Enhancing Ca2+ influx with a conditioning spike train (30 Hz, 3 s) potentiated the KV7/KCNQ channel function and led to a long-lasting, activity-dependent increase in spike frequency adaptation—a gradual reduction in the firing frequency in response to sustained excitation. These effects were abolished by specific blockers for CaV1/L-type Ca2+ channels, KV7/KCNQ channels, and protein kinase A (PKA). Considering the widespread expression of these two channel types, the influence of Ca2+ influx and subsequent activation of PKA on KV7/KCNQ channels may represent a generalized principle in fine tuning the output of central neurons that promotes stability in firing—an example of homeostatic regulation of intrinsic membrane excitability.

scholarly journals Mediation as a source of social development

Temida ◽  
2006 ◽  
Vol 9 (1) ◽  
pp. 21-26
Author(s):  
Ljudmila Alpern
Keyword(s):  
Social Development ◽  
Social Groups ◽  
Special Kind ◽  
Modern Society ◽  
Social Institution ◽  
Old People ◽  
Vulnerable Group ◽  
Social Reforms ◽  
Prison Life ◽  
Former Prisoners

In this paper, the author deals with prison as an archaic social institution, which reflects an archaic conception of human being, his needs and duty, but exists in a modern society. Russian prisons are institutions of a male initiations as well as a Russian army. They give a special sort of male socialization, very archaic and military, patriarchal and hierarchal; produce a special kind of society divided on unmixed social groups, casts, and is very violent. Taking into account how many people go through prison in Russia (rotation near 300 people per year, every 4th man got in contact with prison and every 3rd with army) and a fact that prison and society are communicating vessels, our prisons, our prisoners and former prisoners are a good reserve of our social underdevelopment, social cruelty, our disability to promote social reforms, to take care about vulnerable group of our population (children, old people and female), because they are not a part of male prison and a military hierarchy. An attempt to modernize prison life, prison condition by different way and especially mediation as a way to make them softer and human is an attempt of social development.

scholarly journals TSAL: Two steps Adversarial learning based domain adaptation

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Haidi Hasan Badr ◽  
Nayer Mahmoud Wanas ◽  
Magda Fayek
Keyword(s):  
Network Architecture ◽  
Domain Adaptation ◽  
Data Availability ◽  
Fine Tuning ◽  
Target Domain ◽  
Adversarial Learning ◽  
Prior Art ◽  
Real World Problem ◽  
Wide Range ◽  
Benchmark Datasets

Since labeled data availability differs greatly across domains, Domain Adaptation focuses on learning in new and unfamiliar domains by reducing distribution divergence. Recent research suggests that the adversarial learning approach could be a promising way to achieve the domain adaptation objective. Adversarial learning is a strategy for learning domain-transferable features in robust deep networks. This paper introduces the TSAL paradigm, a two-step adversarial learning framework. It addresses the real-world problem of text classification, where source domain(s) has labeled data but target domain (s) has only unlabeled data. TSAL utilizes joint adversarial learning with class information and domain alignment deep network architecture to learn both domain-invariant and domain-specific features extractors. It consists of two training steps that are similar to the paradigm, in which pre-trained model weights are used as initialization for training with new data. TSAL’s two training phases, however, are based on the same data, not different data, as is the case with fine-tuning. Furthermore, TSAL only uses the learned domain-invariant feature extractor from the first training as an initialization for its peer in subsequent training. By doubling the training, TSAL can emphasize the leverage of the small unlabeled target domain and learn effectively what to share between various domains. A detailed analysis of many benchmark datasets reveals that our model consistently outperforms the prior art across a wide range of dataset distributions.

scholarly journals The Culture of the Sakas of Semirechye: Contemporary State and Current Issues of Study

2021 ◽  
Vol 20 (3) ◽  
pp. 22-35
Author(s):  
Ernar A. Estemesov
Keyword(s):  
Iron Age ◽  
Social Groups ◽  
Archaeological Sites ◽  
Radiocarbon Dates ◽  
Funeral Rites ◽  
The Third ◽  
Urgent Task ◽  
Wide Range ◽  
Burial Mounds ◽  
Second Category

Purpose. The article describes the history and analysis of the main issues in the study of archaeological sites of the Saka period in Semirechye. They are presented by three main types on this territory: burial and memorial complexes, settlements and hoards. The first type of monuments includes numerous burial mounds, where the elite burials of “royal” type and ordinary burials are located. Both social groups are combined by the unity of funeral rites, and the main differences are the complexity of architecture, memorial practices, and richness of burial equipment in the “royal” type burial mounds. The second category of monuments is presented by the settlements that are mostly small in size. The constructions like half dugouts were discovered on them, which gave a rich ceramic material. The third type of monuments of the Saka period in Semirechye includes numerous hoards of bronze items. Some of them are represented by the cult objects (sacrificial tables, lamps and cauldrons) that mark the places of worship. A significant percentage of the hoards contain items of weapons, horse equipment and household purposes and, apparently, serve as offerings to the spirits. However, despite the considerable progress in the study of the Saka monuments of the Semirechye Region, the main problem is their cultural attribution at this time. Some researchers suggest that the independent Saka archaeological culture was formed and developed on the territory of Semirechye in the Early Iron Age, while others believe that the Saka monuments of this region belong to the broader historical and cultural community that also covers the neighboring regions of Kyrgyzstan and Xinjiang. Results Another important issue in the study of the Saka sites of Semirechye is to clarify the chronology of burial and memorial complexes. Up to now, the significant database of radiocarbon dates has been accumulated, which allows us to consider the chronological positions of a wide range of monuments in a new way. It was of great importance to obtain such dates from several burials of Karatuma necropolis, which showed that it belonged to the Saka period, since burial monuments of this appearance are traditionally dated back to the Wusun period. Conclusion. The necessity of solution of these problems is an urgent task for further research of burial and settlement objects of the Saka period in this region.

scholarly journals Системний підхід у дослідженні технологічного процесу збирання льону-довгунця

2013 ◽  
pp. 100-105
Author(s):  
О. А. Примаков
Keyword(s):  
New Technology ◽  
Rational Scheme ◽  
Wide Range ◽  
Necessary And Sufficient ◽  
Selection Of ◽  
Agricultural Machines

Розкривається питання обґрунтування раціональ-ної схеми збирання льону-довгунця із застосуван-ням сільськогосподарських машин загального при-значення. Проведено вибір необхідних та достат-ніх технологічних операцій для збирання льону-довгунця за новою технологією з аналізом кожного окремого елемента. При виборі технічних засобів для збирання льону акцент зроблено не на спеціа-льні льонозбиральні машини, а на техніку, що за-стосовується для збирання інших культур; це ро-бить технологію більш доступною для широкого кола сільгоспвиробників. На основі обґрунтування обраного комплексу технічних засобів складено первинну модель технологічної схеми збирання посіву льону-довгунця. The article reveals the issues of a rational scheme of harvesting flax with the use of agricultural machines for general use. The adequate selection of the necessary and sufficient technical operations for flax harvesting on new technology has been done. When choosing machines for the harvesting of flax a great attention is paid not to special flax pullers but to equipment that is used to harvest other crops, making the technology more accessible to a wide range of manufacturers.

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