Functional Mechanisms

2020 ◽  
pp. 67-88
Author(s):  
Gualtiero Piccinini
Keyword(s):  
Functional Mechanisms ◽  
Adequate Rate

This chapter articulates a goal-contribution account of teleological functions. Teleological functions are causal roles that make a regular contribution to the goals of organisms. Goals can be biological or nonbiological. Biological goals are survival, development, reproduction, and helping. Nonbiological goals are any other goals pursued by organisms. Appropriate situations for the performance of a function are situations in which performing a function provides a regular contribution to a goal of an organism, unless there are more urgent functions to perform. Appropriate rates at which functions should be performed are rates that provide adequate contributions to the goals of an organism, unless there are more urgent functions to perform. Aside from the constraints imposed by tradeoffs between different functions, any condition that lowers the performance of a function below its adequate rate of performance in an appropriate situation results in malfunction.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

An empirical test of situational strength's functional mechanisms

2010 ◽  
Author(s):  
Irwin J. Jose ◽  
Rustin D. Meyer ◽  
Richard Hermida ◽  
Vivek Khare ◽  
Reeshad S. Dalal
Keyword(s):  
Empirical Test ◽  
Functional Mechanisms

Developments in 3D Echocardiography

2009 ◽  
Vol 5 (2) ◽  
pp. 10 ◽  
Author(s):  
Jose Luis Zamorano ◽  
Keyword(s):  
3D Echocardiography ◽  
Resonance Imaging ◽  
Clinical Tool ◽  
3D Images ◽  
Processing Power ◽  
2D Echocardiography ◽  
Automated Quantification ◽  
Heart Cycle ◽  
Functional Mechanisms ◽  
Full Volume

3D echocardiography (3DE) will gain increasing acceptance as a routine clinical tool as the technology evolves due to advances in technology and computer processing power. Images obtained from 3DE provide more accurate assessment of complex cardiac anatomy and sophisticated functional mechanisms compared with conventional 2D echocardiography (2DE), and are comparable to those achieved with magnetic resonance imaging. Many of the limitations associated with the early iterations of 3DE prevented their widespread clinical application. However, recent significant improvements in transducer and post-processing software technologies have addressed many of these issues. Furthermore, the most recent advances in the ability to image the entire heart in realtime and fully automated quantification have poised 3DE to become more ubiquitous in clinical routine. Realtime 3DE (RT3DE) systems offer further improvements in the diagnostic and treatment planning capabilities of cardiac ultrasound. Innovations such as the ability to acquire non-stitched, realtime, full-volume 3D images of the heart in a single heart cycle promise to overcome some of the current limitations of current RT3DE systems, which acquire images over four to seven cardiac cycles, with the need for gating and the potential for stitch artefacts.

New Applications of Oleanolic Acid and its Derivatives as Cardioprotective Agents: A Review of their Therapeutic Perspectives

2019 ◽  
Vol 25 (35) ◽  
pp. 3740-3750 ◽  
Author(s):  
Ning Sun ◽  
Dongli Li ◽  
Xiaoqing Chen ◽  
Panpan Wu ◽  
Yu-Jing Lu ◽  
...  
Keyword(s):  
Oleanolic Acid ◽  
Liver Diseases ◽  
Therapeutic Agent ◽  
Heart Diseases ◽  
Pentacyclic Triterpenoids ◽  
Hepatic Drug ◽  
Approved Drugs ◽  
New Applications ◽  
Functional Mechanisms ◽  
Potent Therapeutic Agent

Oleanolic acid is an analogue of pentacyclic triterpenoids. It has been used as a hepatic drug for over 20 years in China. Currently, there are only five approved drugs derived from pentacyclic triterpenoids, including oleanolic acid (liver diseases), asiaticoside (wound healing), glycyrrhizinate (liver diseases), isoglycyrrhizinate (liver disease) and sodium aescinate (hydrocephalus). To understand more about the bioactivity and functional mechanisms of oleanolic acid, it can be developed as a potent therapeutic agent, in particular, for the prevention and treatment of heart diseases that are the leading cause of death for people worldwide. The primary aim of this mini-review is to summarize the new applications of oleanolic acid and its derivatives as cardioprotective agents reported in recent years and to highlight their therapeutic perspectives in cardiovascular diseases.

scholarly journals Functional mechanisms of MYRF DNA-binding domain mutations implicated in birth defects

2021 ◽  
Vol 296 ◽  
pp. 100612
Author(s):  
Chuandong Fan ◽  
Hongjoo An ◽  
Mohamed Sharif ◽  
Dongkyeong Kim ◽  
Yungki Park
Keyword(s):  
Dna Binding ◽  
Birth Defects ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Functional Mechanisms

scholarly journals bCNN-Methylpred: Feature-Based Prediction of RNA Sequence Modification Using Branch Convolutional Neural Network

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1155
Author(s):  
Naeem Islam ◽  
Jaebyung Park
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Domain Knowledge ◽  
Feature Space ◽  
Experimental Methods ◽  
Machine Learning Techniques ◽  
Rna Modification ◽  
Biological Processes ◽  
Rna Sequence ◽  
Functional Mechanisms

RNA modification is vital to various cellular and biological processes. Among the existing RNA modifications, N6-methyladenosine (m6A) is considered the most important modification owing to its involvement in many biological processes. The prediction of m6A sites is crucial because it can provide a better understanding of their functional mechanisms. In this regard, although experimental methods are useful, they are time consuming. Previously, researchers have attempted to predict m6A sites using computational methods to overcome the limitations of experimental methods. Some of these approaches are based on classical machine-learning techniques that rely on handcrafted features and require domain knowledge, whereas other methods are based on deep learning. However, both methods lack robustness and yield low accuracy. Hence, we develop a branch-based convolutional neural network and a novel RNA sequence representation. The proposed network automatically extracts features from each branch of the designated inputs. Subsequently, these features are concatenated in the feature space to predict the m6A sites. Finally, we conduct experiments using four different species. The proposed approach outperforms existing state-of-the-art methods, achieving accuracies of 94.91%, 94.28%, 88.46%, and 94.8% for the H. sapiens, M. musculus, S. cerevisiae, and A. thaliana datasets, respectively.

Recent progress of MXenes and MXene-based nanomaterials for the electrocatalytic hydrogen evolution reaction

2021 ◽  
Author(s):  
Zhaoming Kang ◽  
Muhammad Arif Khan ◽  
Yanmei Gong ◽  
Rida Javed ◽  
Yuan Xu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Recent Progress ◽  
Recent Advances ◽  
Functional Mechanisms

In this review, recent advances in MXenes and MXene-based nanomaterials applied in HER electrocatalysis are overviewed in terms of their synthesis, characterization, functional mechanisms, and HERperformance/optimization.

scholarly journals Cryo-EM structure of mycobacterial cytochrome bd reveals two oxygen access channels

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weiwei Wang ◽  
Yan Gao ◽  
Yanting Tang ◽  
Xiaoting Zhou ◽  
Yuezheng Lai ◽  
...  
Keyword(s):  
Rational Design ◽  
Pathogenic Bacteria ◽  
Structural Topology ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Cytochrome Bd ◽  
Cryo Electron Microscopy ◽  
Functional Mechanisms ◽  
The Relationship ◽  
Potential Oxygen

AbstractCytochromes bd are ubiquitous amongst prokaryotes including many human-pathogenic bacteria. Such complexes are targets for the development of antimicrobial drugs. However, an understanding of the relationship between the structure and functional mechanisms of these oxidases is incomplete. Here, we have determined the 2.8 Å structure of Mycobacterium smegmatis cytochrome bd by single-particle cryo-electron microscopy. This bd oxidase consists of two subunits CydA and CydB, that adopt a pseudo two-fold symmetrical arrangement. The structural topology of its Q-loop domain, whose function is to bind the substrate, quinol, is significantly different compared to the C-terminal region reported for cytochromes bd from Geobacillus thermodenitrificans (G. th) and Escherichia coli (E. coli). In addition, we have identified two potential oxygen access channels in the structure and shown that similar tunnels also exist in G. th and E. coli cytochromes bd. This study provides insights to develop a framework for the rational design of antituberculosis compounds that block the oxygen access channels of this oxidase.

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