The Cycle of Learning, Memorizing, and Forgetting

2020 ◽  
Author(s):  
Spring Library

Memories are a crucial part of our identity. Learning enhances neuronal growth process that establishes new connections, or neurite retraction to remove existing connections.

Fractals ◽  
1993 ◽  
Vol 01 (02) ◽  
pp. 171-178 ◽  
Author(s):  
KLAUS-D. KNIFFKI ◽  
MATTHIAS PAWLAK ◽  
CHRISTIANE VAHLE-HINZ

The morphology of Golgi-impregnated thalamic neurons was investigated quantitatively. In particular, it was sought to test whether the dendritic bifurcations can be described by the scaling law (d0)n=(d1)n+(d2)nwith a single value of the diameter exponent n. Here d0 is the diameter of the parent branch, d1 and d2 are the diameters of the two daughter branches. Neurons from two functionally distinct regions were compared: the somatosensory ventrobasal complex (VB) and its nociceptive ventral periphery (VBvp). It is shown that for the neuronal trees studied in both regions, the scaling law was fulfilled. The diameter exponent n, however, was not a constant. It increased from n=1.76 for the 1st order branches to n=3.92 for the 7th order branches of neurons from both regions. These findings suggest that more than one simple intrinsic rule is involved in the neuronal growth process, and it is assumed that the branching ratio d0/d1 is not required to be encoded genetically. Furthermore, the results support the concept of the dendritic trees having a statistically identical topology in neurons of VB and VBvp and thus may be regarded as integrative modules.


2014 ◽  
Vol 10 (7) ◽  
pp. 1549-1558 ◽  
Author(s):  
Cristina Riggio ◽  
M. Pilar Calatayud ◽  
Martina Giannaccini ◽  
Beatriz Sanz ◽  
Teobaldo E. Torres ◽  
...  

Author(s):  
J.A. Eades ◽  
E. Grünbaum

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.


Author(s):  
T. Sato ◽  
S. Kitamura ◽  
T. Sueyoshl ◽  
M. Iwatukl ◽  
C. Nielsen

Recently, the growth process and relaxation process of crystalline structures were studied by observing a SI nano-pyramid which was built on a Si surface with a UHV-STM. A UHV-STM (JEOL JSTM-4000×V) was used for studying a heated specimen, and the specimen was kept at high temperature during observation. In this study, the nano-fabrication technique utilizing the electromigration effect between the STM tip and the specimen was applied. We observed Si atoms migrated towords the tip on a high temperature Si surface.Clean surfaces of Si(lll)7×7 and Si(001)2×l were prepared In the UHV-STM at a temperature of approximately 600 °C. A Si nano-pyramid was built on the Si surface at a tunneling current of l0nA and a specimen bias voltage of approximately 0V in both polarities. During the formation of the pyramid, Images could not be observed because the tip was stopped on the sample. After the formation was completed, the pyramid Image was observed with the same tip. After Imaging was started again, the relaxation process of the pyramid started due to thermal effect.


Author(s):  
H. L. Tsai ◽  
J. W. Lee

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).


1990 ◽  
Vol 17 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Maher M. Anous ◽  
Haskell Gruber
Keyword(s):  

2018 ◽  
Vol 13 (Number 2) ◽  
pp. 1-11
Author(s):  
Muhammad Zulqarnain Arshad ◽  
Darwina Arshad

The small and medium-sized enterprises (SMEs) play a crucial part in county’s economic growth and a key contributor in country’s GDP. In Pakistan SMEs hold about 90 percent of the total businesses. The performance of SMEs depends upon many factors. The main aim for the research is to examine the relationship between Innovation Capability, Absorptive Capacity and Performance of SMEs in Pakistan. This conceptual paper also extends to the vague revelation on Business Strategy in which act as a moderator between Innovation Capability, Absorptive Capacity and SMEs Performance. Conclusively, this study proposes a new research directions and hypotheses development to examine the relationship among the variables in Pakistan’s SMEs context.


2018 ◽  
Vol 9 (1) ◽  
pp. 1-16
Author(s):  
S. Karly Kehoe ◽  
Chris Dalglish

Evidence of how history and culture have been or should be harnessed to promote sustainability in remote and rural communities is mounting. To be sustainable, development must come from within, it must serve future generations as well as those in the present and it must attend to the vitality of culture, society, the economy and the environment. Historical research has an important contribution to make to sustainability, especially if undertaken collaboratively, by challenging and transcending the boundaries between disciplines and between the professional researchers, communities and organisations which serve and work with them. The Sustainable Development Goals’ motto is ‘leaving no one behind’, and for the 17 Goals to be met, there must be a dramatic reshaping of the ways in which we interact with each other and with the environment. Enquiry into the past is a crucial part of enabling communities, in all their shapes and sizes, to develop in sustainable ways. This article considers the rural world and posits that historical enquiry has the potential to deliver insights into the world in which we live in ways that allow us to overcome the negative legacies of the past and to inform the planning of more positive and progressive futures. It draws upon the work undertaken with the Landscapes and Lifescapes project, a large partnership exploring the historic links between the Scottish Highlands and the Caribbean, to demonstrate how better understandings of the character and consequences of previous development might inform future development in ways that seek to tackle injustices and change unsustainable ways of living. What we show is how taking charge of and reinterpreting the past is intrinsic to allowing the truth (or truths) of the present situation to be brought to the surface and understood, and of providing a more solid platform for overcoming persistent injustices.


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