scholarly journals Sufficient dimension reduction and prediction in regression

2009 ◽  
Vol 367 (1906) ◽  
pp. 4385-4405 ◽  
Author(s):  
Kofi P. Adragni ◽  
R. Dennis Cook
Keyword(s):  
Applied Sciences ◽  
Dimension Reduction ◽  
Principal Components ◽  
Sufficient Dimension Reduction ◽  
The Past ◽  
New Methods ◽  
Technological Advances ◽  
Broad Overview

Dimension reduction for regression is a prominent issue today because technological advances now allow scientists to routinely formulate regressions in which the number of predictors is considerably larger than in the past. While several methods have been proposed to deal with such regressions, principal components (PCs) still seem to be the most widely used across the applied sciences. We give a broad overview of ideas underlying a particular class of methods for dimension reduction that includes PCs, along with an introduction to the corresponding methodology. New methods are proposed for prediction in regressions with many predictors.

Linking glutamate receptor movements and synapse function

Science ◽  
2020 ◽  
Vol 368 (6496) ◽  
pp. eaay4631 ◽  
Author(s):  
Laurent Groc ◽  
Daniel Choquet
Keyword(s):  
Synaptic Transmission ◽  
Glutamate Receptor ◽  
Dynamic Equilibrium ◽  
Brain Disease ◽  
Receptor Trafficking ◽  
Degradation Pathways ◽  
Neurotransmitter Receptor ◽  
The Past ◽  
New Methods ◽  
Technological Advances

Regulation of neurotransmitter receptor content at synapses is achieved through a dynamic equilibrium between biogenesis and degradation pathways, receptor stabilization at synaptic sites, and receptor trafficking in and out synapses. In the past 20 years, the movements of receptors to and from synapses have emerged as a series of highly regulated processes that mediate postsynaptic plasticity. Our understanding of the properties and roles of receptor movements has benefited from technological advances in receptor labeling and tracking capacities, as well as from new methods to interfere with their movements. Focusing on two key glutamatergic receptors, we review here our latest understanding of the characteristics of receptor movements and their role in tuning the efficacy of synaptic transmission in health and brain disease.

The sleeping beauty kissed awake: new methods in electron microscopy to study cellular membranes

2017 ◽  
Vol 474 (6) ◽  
pp. 1041-1053 ◽  
Author(s):  
Petr Chlanda ◽  
Jacomine Krijnse Locker
Keyword(s):  
Electron Microscopy ◽  
Cell Biology ◽  
Sleeping Beauty ◽  
Chemical Fixation ◽  
Preparation Methods ◽  
Complementary Method ◽  
The Past ◽  
New Methods ◽  
Technological Advances ◽  
Infected Cells

Electron microscopy (EM) for biological samples, developed in the 1940–1950s, changed our conception about the architecture of eukaryotic cells. It was followed by a period where EM applied to cell biology had seemingly fallen asleep, even though new methods with important implications for modern EM were developed. Among these was the discovery that samples can be preserved by chemical fixation and most importantly by rapid freezing without the formation of crystalline ice, giving birth to the world of cryo-EM. The past 15–20 years are hallmarked by a tremendous interest in EM, driven by important technological advances. Cryo-EM, in particular, is now capable of revealing structures of proteins at a near-atomic resolution owing to improved sample preparation methods, microscopes and cameras. In this review, we focus on the challenges associated with the imaging of membranes by EM and give examples from the field of host–pathogen interactions, in particular of virus-infected cells. Despite the advantages of imaging membranes under native conditions in cryo-EM, conventional EM will remain an important complementary method, in particular if large volumes need to be imaged.

Education for General Practice—Worldwide Problems

1972 ◽  
Vol 2 (2) ◽  
pp. 171-181
Author(s):  
P. S. Byrne
Keyword(s):  
General Practice ◽  
General Practitioner ◽  
Vocational Training ◽  
Continuing Care ◽  
The Past ◽  
New Methods ◽  
Technological Advances ◽  
Recent Developments ◽  
Definition Of ◽  
Terminological Confusion

Although there is terminological confusion over the definition of general practitioner, it is agreed that there must be, in all systems, a “physician who provides personal primary and continuing care to individuals and families.” Factors influencing general practice include geography and urbanization, social pressures, technological advances, specialization within the hospital field, and cost–effectiveness. The general practitioner is a specialist in a special field who requires special training for his work. In the recent past departments of social medicine have been involved in the teaching of general practice. This has not been successful. Recent developments have dramatized the large number of special departments of general practice or family medicine throughout the world which are contributing much to teaching in the undergraduate period and in vocational training. They are also contributing to new methods of education and assessment which have wider applications. The past decade has seen the emergence of general practice as a special branch of medical education in its own right. The future is full of challenges to develop further and to create a new cadre of teachers in this field.

FM Verification for the 21 st Century

2008 ◽  
Vol 18 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Leisha Eiten ◽  
Dawna Lewis
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Current Technology ◽  
The Past ◽  
Technological Advances ◽  
Children With Hearing Loss

Background: For children with hearing loss, the benefits of FM systems in overcoming deleterious effects of noise, distance, and reverberation have led to recommendations for use beyond classroom settings. It is important that audiologists who recommend and fit these devices understand the rationale and procedures underlying fitting and verification. Objectives: This article reviews previousguidelines for FM verification, addresses technological advances, and introduces verification procedures appropriate for current FM and hearing-aid technology. Methods: Previous guidelines for verification of FM systems are reviewed. Those recommendations that are appropriate for current technology are addressed, as are procedures that are no longer adequate for hearing aids and FM systems utilizing more complex processing than in the past. Technological advances are discussed, and an updated approach to FM verification is proposed. Conclusions: Approaches to verification andfitting of FM systems must keep pace with advances in hearing-aid and FM technology. The transparency approach addressed in this paper is recommended for verification of FM systems coupled to hearing aids.

Recovery boiler sootblowers: History and technological advances

TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA
Keyword(s):  
Cfd Modeling ◽  
Computing Systems ◽  
The Past ◽  
Technological Advances ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Steam Parameters ◽  
Insight Into ◽  
Deposit Removal

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.

Catholicism and Cosmopolitanism: the Confluence of Three Catholic Scholars and the Cosmopolitan Democrats on State Sovereignty and the Future of Global Governance

2016 ◽  
Vol 3 (2) ◽  
pp. 37-51
Author(s):  
Matthew Bagot
Keyword(s):  
Global Governance ◽  
State Sovereignty ◽  
Current Debate ◽  
Past Century ◽  
Jacques Maritain ◽  
The Past ◽  
Technological Advances ◽  
The Future ◽  
Cosmopolitan Democracy ◽  
Catholic Tradition

One of the central questions in international relations today is how we should conceive of state sovereignty. The notion of sovereignty—’supreme authority within a territory’, as Daniel Philpott defines it—emerged after the Treaty of Westphalia in 1648 as a result of which the late medieval crisis of pluralism was settled. But recent changes in the international order, such as technological advances that have spurred globalization and the emerging norm of the Responsibility to Protect, have cast the notion of sovereignty into an unclear light. The purpose of this paper is to contribute to the current debate regarding sovereignty by exploring two schools of thought on the matter: first, three Catholic scholars from the past century—Luigi Sturzo, Jacques Maritain, and John Courtney Murray, S.J.—taken as representative of Catholic tradition; second, a number of contemporary political theorists of cosmopolitan democracy. The paper argues that there is a confluence between the Catholic thinkers and the cosmopolitan democrats regarding their understanding of state sovereignty and that, taken together, the two schools have much to contribute not only to our current understanding of sovereignty, but also to the future of global governance.

The Evolution of Lead Extraction

2009 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Melanie Maytin ◽  
Laurence M Epstein ◽  
◽  
Keyword(s):  
Natural Selection ◽  
Lead Extraction ◽  
Significant Morbidity ◽  
Extraction Techniques ◽  
Extraction Technology ◽  
Device Management ◽  
Future Developments ◽  
The Past ◽  
New Methods ◽  
Life Threatening

Prior to the introduction of successful intravascular countertraction techniques, options for lead extraction were limited and dedicated tools were non-existent. The significant morbidity and mortality associated with these early extraction techniques limited their application to life-threatening situations such as infection and sepsis. The past 30 years have witnessed significant advances in lead extraction technology, resulting in safer and more efficacious techniques and tools. This evolution occurred out of necessity, similar to the pressure of natural selection weeding out the ineffective and highly morbid techniques while fostering the development of safe, successful and more simple methods. Future developments in lead extraction are likely to focus on new tools that will allow us to provide comprehensive device management and the design of new leads conceived to facilitate future extraction. With the development of these new methods and novel tools, the technique of lead extraction will continue to require operators that are well versed in several methods of extraction. Garnering new skills while remembering the lessons of the past will enable extraction technologies to advance without repeating previous mistakes.

A summary of beach nourishment in China: The past decade of practices

Shore & Beach ◽  
2020 ◽  
pp. 65-73
Author(s):  
Gen Liu ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Jianhui Liu ◽  
Gang Lei ◽  
...  
Keyword(s):  
Beach Nourishment ◽  
Developed Countries ◽  
Ecological Design ◽  
Optimized Design ◽  
Limited Information ◽  
Personal Communications ◽  
Design Considerations ◽  
The Past ◽  
Technological Advances ◽  
Urban Beaches

Beach nourishment has been widely used for beach protection around the world. However, there is limited information about beach nourishment in China. This study offers an overview of beach nourishment practices, status and technological advances in China, based on the literature, reports, and personal communications. The results demonstrate that beach nourishment has been recognized as an effective and environmentally friendly measure to combat coastal erosion and has been increasingly adopted in China, especially in the past decade. The unique characteristics of coastal China resulted in a difference in beach nourishment between China and Western developed countries in terms of the types, objectives, and shapes of beach nourishment. For the types of nourishments in China, there were approximately the same number of restored beaches and newly constructed beaches. For fill sediment, homogeneous fill and heterogeneous fill comprised 51.1% and 48.9% of projects, respectively. The objective of beach nourishment was mainly to promote coastal tourism, and the shape of nourished beaches was dominated by headland bays. This study also indicated that China has achieved a number of technological advances in beach nourishment, including methods of beach nourishment on severely eroded coasts and muddy coasts, an optimized design of drain pipes involved in urban beaches, and ecological design considerations. From the past decade of practices, four aspects were proposed as considerations for future nourishment: sand sources, technique advances, ecological effects, and management of beach nourishments.

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