Monosaccharide status of pre-Mazama Ahb horizons in Alberta, Canada

1994 ◽  
Vol 74 (1) ◽  
pp. 55-58 ◽  
Author(s):  
J. F. Dormaar
Keyword(s):  
Time Window ◽  
Buried Soils ◽  
Tephra Fall ◽  
Surface Stability ◽  
Chernozemic Soil ◽  
Long Time ◽  
A Site ◽  
Palaeoenvironmental Conditions ◽  
Original Organic Matter

Palaeosols, formed prior to deposition of Mazama tephra (6600 yr B.P.), are widespread in Alberta. Palaeo-Ahb horizons are readily identifiable, with colors ranging from very dark gray to gray and brown. Establishment of fundamental and stable properties of the original organic matter would facilitate the classification of these buried soils. Use of a suite of eight monosaccharides divided the 15 palaeosols examined in this study into one group of three, possibly formed under Brown Chernozemic soil-forming conditions or drier, and the remainder, possibly formed under Black Chernozemic soil-forming conditions. The former had C/N ratios approaching those of microorganisms and low xylose to mannose ratios. It is concluded that, because of the long time-window of surface stability between deglaciation and the Mazama tephra fall, pre-Mazama palaeosols can only be studied on a site-specific basis. Grouping these palaeosols, based on their pre-Mazama tephra deposition only, is not realistic. Synthesis of a unified hypothesis of palaeoenvironmental conditions is, therefore, not possible using only their monosaccharide status. Key words: Holocene soils, palaeosols, buried soils, monosaccharides, landscape

Time Window from Visual Images to Visual Short-Term Memory: Consolidation or Integration?

2004 ◽  
Vol 51 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Yuhong Jiang
Keyword(s):  
Short Term Memory ◽  
Time Window ◽  
Short Interval ◽  
Visual Images ◽  
Short Term ◽  
Temporal Window ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Probe Task ◽  
Long Time

Abstract. When two dot arrays are briefly presented, separated by a short interval of time, visual short-term memory of the first array is disrupted if the interval between arrays is shorter than 1300-1500 ms ( Brockmole, Wang, & Irwin, 2002 ). Here we investigated whether such a time window was triggered by the necessity to integrate arrays. Using a probe task we removed the need for integration but retained the requirement to represent the images. We found that a long time window was needed for performance to reach asymptote even when integration across images was not required. Furthermore, such window was lengthened if subjects had to remember the locations of the second array, but not if they only conducted a visual search among it. We suggest that a temporal window is required for consolidation of the first array, which is vulnerable to disruption by subsequent images that also need to be memorized.

CELL AND TISSUE THERAPY OF HEART

2019 ◽  
pp. 77-84
Keyword(s):  
Extracellular Matrix ◽  
Cell Types ◽  
Heart Tissue ◽  
Decellularized Extracellular Matrix ◽  
Tissue Therapy ◽  
Essential Components ◽  
Long Time ◽  
Different Populations ◽  
A Site ◽  
Recipient Tissue

The strategy of heart tissue engineering is simple enough: first remove all the cells from a organ then take the protein scaffold left behind and repopulate it with stem cells immunologically matched to the patient in need. While various suc- cessful methods for decellularization have been developed, and the feasibility of using decellularized whole hearts and extracellular matrix to support cells has been demonstrated, the reality of creating whole hearts for transplantation and of clinical application of decellularized extracellular matrix-based scaffolds will require much more research. For example, further investigations into how lineage-restricted progenitors repopulate the decellularized heart and differentiate in a site-specific manner into different populations of the native heart would be essential. The scaffold heart does not have to be human. Pig hearts carries all the essential components of the extracellular matrix. Through trial and error, scaling up the concentration, timing and pressure of the detergents, researchers have refined the decellularization process on hundreds of hearts and other organs, but this is only the first step. Further, the framework must be populated with human cells. Most researchers in the field use a mixture of two or more cell types, such as endothelial precursor cells to line blood vessels and muscle progenitors to seed the walls of the chambers. The final challenge is one of the hardest: vasculariza- tion, placing a engineered heart into a living animal, integration with the recipient tissue, and keeping it beating for a long time. Much remains to be done before a bioartificial heart is available for transplantation in humans.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

scholarly journals How immunologic and genetic biomarkers impact Hodgkin lymphoma classification, diagnosis, and management: a huge potential that yet needs to be exploited

2017 ◽  
Vol 33 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Antonino Carbone ◽  
Annunziata Gloghini
Keyword(s):  
Hodgkin Lymphoma ◽  
Molecular Genetic ◽  
Scientific Basis ◽  
Grey Zone ◽  
Molecular Virology ◽  
Barr Virus ◽  
Long Time ◽  
Modern Classification ◽  
Epstein Barr

“Ne è passata di acqua sotto i ponti.” It has been a long time since the diagnosis of Hodgkin lymphoma (HL) was exclusively based on the detection of typical Reed-Sternberg cells and the recognition of the characteristic morpho-histological background, as well as on the pathologist’s skill. The discovery of immunologic, molecular genetic and virologic biomarkers has provided an objective contribution to the diagnosis and a scientific basis for a modern classification of HL. Recent updates have clarified the nature of the so-called nodular lymphocyte predominant HL and its link to the T-cell/histiocyte-rich large B-cell lymphomas as well as its relationship with the lymphocyte-rich subset of classical HL (CHL). Molecular virology studies assessed a role for the Epstein-Barr virus in the pathogenesis of a fraction of CHL of the general population, and virtually in all cases of CHL occurring in people infected by HIV. Finally, immunologic and genetic findings corroborated the existence of grey zone lymphomas at the edges of CHL. Overall, these advances provided additional and useful information to address the treatment of patients affected by HL.

scholarly journals DECISION TREE C4.5 ALGORITHM FOR TUITION AID GRANT PROGRAM CLASSIFICATION (CASE STUDY: DEPARTMENT OF INFORMATION SYSTEM, UNIVERSITAS TEKNOKRAT INDONESIA)

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Heni Sulistiani ◽  
Ahmad Ari Aldino
Keyword(s):  
Decision Tree ◽  
Classification Model ◽  
Grant Program ◽  
C4.5 Algorithm ◽  
Long Time ◽  
The Right ◽  
Short Time ◽  
Tuition Fee

In pandemic era, almost everyone struggles for their life. College students are such example. They have difficulty in paying tuition fee to continue their study. Based on this problematic situation, Universitas Teknokrat Indonesia grants the students who have good academic performance with tuition fee aid program. Many variables used for determining the grant made it hard to make a decision in a short time or even takes very long time. To make it easier for management to decide who is the right student to get grant, it needs classification model. The purpose of this study is the classification of grant recipients by using decision tree C4.5 algorithm. That can determine whether a potential student can be accepted as an awardee or not. Then, the results of the classification are validated with ten-fold cross validation with an accuracy, precision and recall with the score of 87 % for all part. It means the model perform quite well to be implemented into system.

scholarly journals Nonlinear Classification of EEG recordings from patients with Alzheimer’s Disease using Gaussian Process Latent Variable Model

2020 ◽  
Author(s):  
S. Rajintha. A. S. Gunawardena ◽  
Fei He ◽  
Ptolemaios Sarrigiannis ◽  
Daniel J. Blackburn
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gaussian Process ◽  
Manifold Learning ◽  
Latent Variable ◽  
Time Window ◽  
Support Vector ◽  
Nonlinear Dimensionality Reduction ◽  
Variable Model

AbstractIn this work, nonlinear temporal features from multi-channel EEGs are used for the classification of Alzheimer’s disease patients from healthy individuals. This was achieved by temporal manifold learning using Gaussian Process Latent Variable Models (GPLVM) as a nonlinear dimensionality reduction technique. Classification of the extracted features was undertaken using a nonlinear Support Vector Machine. Comparisons were made against the linear counterpart, Principle Component Analysis while exploring the effect of the time window or EEG epoch length used. It was demonstrated that temporal manifold learning using GPLVM is better in extracting features that attain high separability and prediction accuracy. This work aims to set the significance of using GPLVM temporal manifold learning for EEG feature extraction in the classification of Alzheimer’s disease.

scholarly journals Application of Latent Dirichlet Allocation (LDA) for clustering financial tweets

2021 ◽  
Vol 297 ◽  
pp. 01071
Author(s):  
Sifi Fatima-Zahrae ◽  
Sabbar Wafae ◽  
El Mzabi Amal
Keyword(s):  
Language Processing ◽  
Latent Dirichlet Allocation ◽  
Sentiment Classification ◽  
Research Areas ◽  
Preprocessing Method ◽  
Long Time ◽  
Standard Text ◽  
The Given ◽  
Dirichlet Allocation

Sentiment classification is one of the hottest research areas among the Natural Language Processing (NLP) topics. While it aims to detect sentiment polarity and classification of the given opinion, requires a large number of aspect extractions. However, extracting aspect takes human effort and long time. To reduce this, Latent Dirichlet Allocation (LDA) method have come out recently to deal with this issue.In this paper, an efficient preprocessing method for sentiment classification is presented and will be used for analyzing user’s comments on Twitter social network. For this purpose, different text preprocessing techniques have been used on the dataset to achieve an acceptable standard text. Latent Dirichlet Allocation has been applied on the obtained data after this fast and accurate preprocessing phase. The implementation of different sentiment analysis methods and the results of these implementations have been compared and evaluated. The experimental results show that the combined uses of the preprocessing method of this paper and Latent Dirichlet Allocation have an acceptable results compared to other basic methods.

scholarly journals Evolution of andrenine bees reveals a long and complex history of faunal interchanges between the Americas during the Mesozoic and Cenozoic

2021 ◽  
Author(s):  
Kelli S Ramos ◽  
Aline C Martins ◽  
Gabriel A R Melo
Keyword(s):  
North America ◽  
South America ◽  
Time Window ◽  
Distributional Pattern ◽  
Long Distance ◽  
Early Diversification ◽  
Palearctic Region ◽  
Long Time ◽  
The Times ◽  
Dated Phylogeny

Bees are presumed to have arisen in the early to mid-Cretaceous coincident with the fragmentation of the southern continents and concurrently with the early diversification of the flowering plants. Among the main groups of bees, Andreninae sensu lato comprise about 3000 species widely distributed with greatest and disjunct diversity in arid areas of North America, South America, and the Palearctic region. Here, we present the first comprehensive dated phylogeny and historical biogeographic analysis for andrenine bees, including representatives of all currently recognized tribes. Our analyses rely on a dataset of 106 taxa and 7952 aligned nucleotide positions from one mitochondrial and six nuclear loci. Andreninae is strongly supported as a monophyletic group and the recovered phylogeny corroborates the commonly recognized clades for the group. Thus, we propose a revised tribal classification that is congruent with our phylogenetic results. The time-calibrated phylogeny and ancestral range reconstructions of Andreninae reveal a fascinating evolutionary history with Gondwana patterns that are unlike those observed in other subfamilies of bees. Andreninae arose in South America during the Late Cretaceous around 90 Million years ago (Ma) and the origin of tribes occurred through a relatively long time-window from this age to the Miocene. The early evolution of the main lineages took place in South America until the beginning of Paleocene with North American fauna origin from it and Palearctic from North America as results of multiple lineage interchanges between these areas by long-distance dispersal or hopping through landmass chains. Overall, our analyses provide strong evidence of amphitropical distributional pattern currently observed in Andreninae in the American continent as result at least three periods of possible land connections between the two American landmasses, much prior to the Panama Isthmus closure. The andrenine lineages reached the Palearctic region through four dispersal events from North America during the Eocene, late Oligocene and early Miocene, most probably via the Thulean Bridge. The few lineages with Afrotropical distribution likely originated from a Palearctic ancestral in the Miocene around 10 Ma when these regions were contiguous, and the Sahara Desert was mostly vegetated making feasible the passage by several organisms. Incursions of andrenine bees to North America and then onto the Old World are chronological congruent with distinct periods when open-vegetation habitats were available for trans-continental dispersal and at the times when aridification and temperature decline offered favorable circumstances for bee diversification.

scholarly journals Analysis of the Strong and Weak Monotonic External Stability of the Resonance in a Perturbed Dynamical System

2021 ◽  
Vol 16 ◽  
pp. 180-191
Author(s):  
Vladislav V. Lyubimov
Keyword(s):  
Dynamical System ◽  
Sufficient Conditions ◽  
Strong Stability ◽  
New Classification ◽  
External Stability ◽  
Fast Phase ◽  
Stability And Instability ◽  
Long Time ◽  
Independent Variable

A perturbed dynamical system involving two ordinary differential equations is under review. Whereupon, the differential equation for determining the fast phase contains the ratio of the two frequencies. When these frequencies coincide for a long time, a resonance is implemented in this system. The aim of this paper is to obtain the conditions of monotonic external stability and instability of this resonance. The sufficient conditions for the external stability and instability of the resonance defined in this paper assume that the signs of the analyzed derivatives remain unchanged in the non-resonant section of the change in the independent variable. This paper gives a new classification of the phenomenon of external stability of resonance, which includes weak, linear, and strong stability. It should be noted that the conditions of monotonic external stability and instability of the resonance presented in this paper can be used in various scientific and technological problems, in which resonances are observed. Particularly, the concluding part of the paper considers the application of the results obtained within the framework of the problem of the perturbed motion of a rigid body relative to a fixed point.

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