Using compounds modified by the isotopes carbon-13 and nitrogen-15 helps conduct research in various fields of science, such as medicine, pharmacology, pharmacokinetics, metabolism, agriculture, and others. In the cas...Using compounds modified by the isotopes carbon-13 and nitrogen-15 helps conduct research in various fields of science, such as medicine, pharmacology, pharmacokinetics, metabolism, agriculture, and others. In the case of the availability of reliable, express, and cheap methods, the area of their use will gradually expand. A determination of the atomic fraction of the isotopes carbon-13 and nitrogen-15 directly in glycine, leucine, isoleucine, and alanine is proposed;the modification concerns all centers or one or more identical carbon and nitrogen centers separately, as well as both isotopes at the same time. There are defined mass lines of the mass spectrum of each amino acid, through which the isotopic content of carbon and nitrogen is calculated. The processes that must be taken into account for the determination of the isotopic content are also established. Isotopic analysis of these compounds until now was carried out by transforming them into carbon oxide, dioxide, and molecular nitrogen, and determination of their content in individual centers was impossible.展开更多
Fragmentary data is becoming more and more popular in many areas which brings big chal-lenges to researchers and data analysts.Most existing methods dealing with fragmentary data consider a continuous response while i...Fragmentary data is becoming more and more popular in many areas which brings big chal-lenges to researchers and data analysts.Most existing methods dealing with fragmentary data consider a continuous response while in many applications the response variable is discrete.In this paper,we propose a model averaging method for generalized linear models in fragmentary data prediction.The candidate models are fitted based on different combinations of covariate availability and sample size.The optimal weight is selected by minimizing the Kullback-Leibler loss in the completed cases and its asymptotic optimality is established.Empirical evidences from a simulation study and a real data analysis about Alzheimer disease are presented.展开更多
Identification of unknown remains recovered from marine and terrestrial locations is a significant humanitarian problem.This investigation proposes a simple method applicable to fragmentary femora for a more refined l...Identification of unknown remains recovered from marine and terrestrial locations is a significant humanitarian problem.This investigation proposes a simple method applicable to fragmentary femora for a more refined level of ancestry and/or sex estimation.To that end,we re-examined Purkait’s triangle which involves three inter-landmark distances between the traction epiphyses and the articular rim of femoral head.A large sample(n=584)from geographically diverse(Egyptian,Indian and Greek)populations was compiled.Additionally,shape(n=3)and trigonometrically derived variables and ratios(n=9 variables)were employed to detect any geographically-clustered morphological differences between these populations.Random forest modelling(RFM)and linear discriminant function analysis(LDA)were employed to create classification models in instances where sex was known or unknown.The sample was apportioned into training and test sets with a ratio 70/30.The classification accuracies were evaluated by means of k fold cross-validation procedure.In sex estimation,RFM showed similar performance to LDA.However,RFM outperformed LDA in ancestry estimation.Ancestry estimation was satisfactory in the Indian and Egyptian samples albeit the Greek sample was problematic.The Greek samples presented greater morphological overlap with the Indian sample due to high within-group variation.Test samples were accurately assigned to their ancestral category when sex was known.Generally,higher classification accuracies in the validation sample were obtained in the sex-specific model of females than in males.Using RFM and the linear variables,the overall accuracy reached 83%which is distributed as 95%,71%and 86%for the Egyptian,Indian and Greek females,respectively;whereas in males,the overall accuracy is 72%and is distributed as 58%,87%and 50%for the Egyptian,Indian and Greek males,respectively.Classification accuracies were also calculated per group in the test data using the 12 derived variables.For the females,the accuracies using the medians model 展开更多
Everyone is living with two hearts.One is controlled by the social rules and moral standards while the other is possessed by wild fantasies that go against the conventions.The first may be called reason and the second...Everyone is living with two hearts.One is controlled by the social rules and moral standards while the other is possessed by wild fantasies that go against the conventions.The first may be called reason and the second inner passion.More often than not people try to behave as good and normal as the society expects them to be but keep a tight lid on their feelings that do not fit in the moral requirements.Struggling between the two,a lot of writers have delved into the discussion of the humanity division,attempting to seek for the wholeness of humanity again.Chopin and Melville are without exception.Their characters-Edna and IshmaelAhab are all beings with split minds and fragmentary personalities.Through frustrations and determinations,those characters demonstrate the sorrows of incomplete humanity and lead readers to aware their own incompleteness,think about the issue seriously and make up their mind to pursuit the wholeness of their soul.展开更多
文摘Using compounds modified by the isotopes carbon-13 and nitrogen-15 helps conduct research in various fields of science, such as medicine, pharmacology, pharmacokinetics, metabolism, agriculture, and others. In the case of the availability of reliable, express, and cheap methods, the area of their use will gradually expand. A determination of the atomic fraction of the isotopes carbon-13 and nitrogen-15 directly in glycine, leucine, isoleucine, and alanine is proposed;the modification concerns all centers or one or more identical carbon and nitrogen centers separately, as well as both isotopes at the same time. There are defined mass lines of the mass spectrum of each amino acid, through which the isotopic content of carbon and nitrogen is calculated. The processes that must be taken into account for the determination of the isotopic content are also established. Isotopic analysis of these compounds until now was carried out by transforming them into carbon oxide, dioxide, and molecular nitrogen, and determination of their content in individual centers was impossible.
基金The research of Fang was supported by National Key R&D Program of China[grant numbers 2021YFA1000100,2021YFA1000101]National Natural Science Foundation of China[grant numbers 11831008,12071143].
文摘Fragmentary data is becoming more and more popular in many areas which brings big chal-lenges to researchers and data analysts.Most existing methods dealing with fragmentary data consider a continuous response while in many applications the response variable is discrete.In this paper,we propose a model averaging method for generalized linear models in fragmentary data prediction.The candidate models are fitted based on different combinations of covariate availability and sample size.The optimal weight is selected by minimizing the Kullback-Leibler loss in the completed cases and its asymptotic optimality is established.Empirical evidences from a simulation study and a real data analysis about Alzheimer disease are presented.
基金study was conducted retrospectively from radiological database obtained for clinical purposes with institutional approvals.The study protocol has been approved by the Research Ethics Committee of faculty of medicine,Alexandria University,Egypt.(IRB NO.:00012098-FWA NO.:00018699,Serial NO.0304532).
文摘Identification of unknown remains recovered from marine and terrestrial locations is a significant humanitarian problem.This investigation proposes a simple method applicable to fragmentary femora for a more refined level of ancestry and/or sex estimation.To that end,we re-examined Purkait’s triangle which involves three inter-landmark distances between the traction epiphyses and the articular rim of femoral head.A large sample(n=584)from geographically diverse(Egyptian,Indian and Greek)populations was compiled.Additionally,shape(n=3)and trigonometrically derived variables and ratios(n=9 variables)were employed to detect any geographically-clustered morphological differences between these populations.Random forest modelling(RFM)and linear discriminant function analysis(LDA)were employed to create classification models in instances where sex was known or unknown.The sample was apportioned into training and test sets with a ratio 70/30.The classification accuracies were evaluated by means of k fold cross-validation procedure.In sex estimation,RFM showed similar performance to LDA.However,RFM outperformed LDA in ancestry estimation.Ancestry estimation was satisfactory in the Indian and Egyptian samples albeit the Greek sample was problematic.The Greek samples presented greater morphological overlap with the Indian sample due to high within-group variation.Test samples were accurately assigned to their ancestral category when sex was known.Generally,higher classification accuracies in the validation sample were obtained in the sex-specific model of females than in males.Using RFM and the linear variables,the overall accuracy reached 83%which is distributed as 95%,71%and 86%for the Egyptian,Indian and Greek females,respectively;whereas in males,the overall accuracy is 72%and is distributed as 58%,87%and 50%for the Egyptian,Indian and Greek males,respectively.Classification accuracies were also calculated per group in the test data using the 12 derived variables.For the females,the accuracies using the medians model
文摘Everyone is living with two hearts.One is controlled by the social rules and moral standards while the other is possessed by wild fantasies that go against the conventions.The first may be called reason and the second inner passion.More often than not people try to behave as good and normal as the society expects them to be but keep a tight lid on their feelings that do not fit in the moral requirements.Struggling between the two,a lot of writers have delved into the discussion of the humanity division,attempting to seek for the wholeness of humanity again.Chopin and Melville are without exception.Their characters-Edna and IshmaelAhab are all beings with split minds and fragmentary personalities.Through frustrations and determinations,those characters demonstrate the sorrows of incomplete humanity and lead readers to aware their own incompleteness,think about the issue seriously and make up their mind to pursuit the wholeness of their soul.
