1,467 research outputs found
Age differences between distributions of genotypes among pregnant women: evidence of fertility selection.
SummaryThe number of children produced by a modern woman is usually below her total reproductive capacity and is determined by circumstances other than natural selection. It is, therefore, practically impossible to detect differences in natural fertilities associated with different types (e.g. phenotypes, genotypes) of women. This does not mean, however, that natural selection at the reproductive level cannot at all be detected today. If women of a particular type have high natural fertility, this usually means that they reproduce (become pregnant) at a higher rate than women of a type with lower natural fertility. Hence, when there is a limit on the number of children, women of the first type will reach the limit at an earlier age than women of the second type. As a result, types that have a higher natural fertility should be overrepresented among pregnant women of younger ages and, consequently, underrepresented among older ones, as compared to types with a lower natural fertility. Based on this notion, a model of age-related differences between distributions of types among pregnant women is suggested. The model is applied to data on MNSs-blood group and PGM1 (phosphoglucomutase) types in a sample of pregnant women and an evidence of natural selection at the reproduction level associated with these genetic markers is obtained
Smoking, haptoglobin and fertility in humans
A prospective study on two samples of consecutive puerperae (total n° 667) from two populations has been carried out in order to investigate the possible effect of smoking habit on relationship between fertility and haptoglobin phenotype
Extension of the A-UNIFAC model to mixtures of cross- and self-associating compounds
http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=4&SID=V21Di6PajaHLPoM3@AJ&page=1&doc=1&colname=WOSIn the present work an extended UNIFAC group contribution model is used to calculate activity coefficients in solutions containing alcohols,
water, carboxylic acids, esters, alkanes and aromatic hydrocarbons. The limiting expressions for the association contribution to the activity
coefficients at infinite dilution are presented and discussed. A new set of interaction parameters between associating and non-associating
functional groups is reported. This set of parameters is applied in the association model to predict vapor–liquid, liquid–liquid equilibrium and
infinite dilution activity coefficients.The authors are grateful to the National Research Council
of Argentina (CONICET) and to Universidad Nacional del Sur (UNS) for financial support. O. Ferreira acknowledges financial support from the PRAXIS program, FCT, Lisbon,
Portugal (SFRH/BD/879/2000)
Coronary Artery Disease: A Study on the Joint Role of Birth Weight, Adenosine Deaminase, and Gender
An inverse relationship between birth weight and coronary artery diseases is well documented but it remains unclear which exposure in early life might underlie such association. Recently it has been reported an association between adenosine deaminase genetic polymorphism and coronary artery diseases. Gender differences in the degree of this association have been also observed. These observations prompted us to study the possible joint effects of BW, ADA, and gender on the susceptibility to coronary artery diseases. 222 subjects admitted to hospital for nonfatal coronary artery diseases, and 762 healthy consecutive newborns were studied. ADA genotypes were determined by DNA analysis. A highly significant complex relationship has emerged among ADA, birth weight, and gender concerning their role on susceptibility to coronary artery diseases in adult life. Odds ratio analysis suggests that low birth weight is more important in females than in males. ADA∗2 allele appears protective in males, while in females such effect is obscured by birth weight
Phosphotyrosine-protein-phosphatases and human reproduction: an association between low molecular weight acid phosphatase (ACP1) and spontaneous abortion.
ACP1 (low molecular weight acid phosphatase) genetic polymorphism has been studied in 173 women with a history of two or more consecutive spontaneous abortions and in 1508 control subjects, including 482 normal pregnant women. The proportion of carriers of ACP1 *C allele (* A/ *C, *B/*C) in women with a history of repeated spontaneous abortion is lower than in normal pregnant women and other control groups, Women with repeated spontaneous abortion show a specific decrease of ACPI S isoform concentration as compared to normal pregnant women, The other component of ACP I activity, the F isoform, does not show a significant difference between the two groups. The data suggest that women with ACP1 genotypes showing a high concentration of S isoform are relatively 'protected' against spontaneous abortion, Preliminary analysis of a sample of 352 normal puerperae along with their newborn babies supports this hypothesis
Categorical Landau Paradigm for Gapped Phases
We propose a unified framework to classify gapped infra-red (IR) phases with
categorical symmetries, leading to a generalized, categorical Landau paradigm.
This is applicable in any dimension and gives a succinct, comprehensive, and
computationally powerful approach to classifying gapped symmetric phases. The
key tool is the symmetry topological field theory (SymTFT), which is a one
dimension higher TFT with two boundaries, which we choose both to be
topological. We illustrate the general idea for (1+1)d gapped phases with
categorical symmetries and suggest higher-dimensional extensions.Comment: 4 pages + supplementary materia
Non-invertible symmetry webs
Non-invertible symmetries have by now seen numerous constructions in higher dimensional Quantum Field Theories (QFT). In this paper we provide an in depth study of gauging 0-form symmetries in the presence of non-invertible symmetries. The starting point of our analysis is a theory with
0-form symmetry, and we propose a description of sequential partial gaugings of sub-symmetries. The gauging implements the theta-symmetry defects of the companion paper [SciPost Phys. 15, 122 (2023)]. The resulting network of symmetry structures related by this gauging will be called a non-invertible symmetry web. Our formulation makes direct contact with fusion 2-categories, and we uncover numerous interesting structures such as symmetry fractionalization in this categorical setting. The complete symmetry web is derived for several groups
, and we propose extensions to higher dimensions. The highlight of this analysis is the complete categorical symmetry web, including non-invertible symmetries, for 3d pure gauge theories with orthogonal gauge groups and its extension to arbitrary dimensions
High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite
Gapped Phases with Non-Invertible Symmetries: (1+1)d
We propose a general framework to characterize gapped infra-red (IR) phases
of theories with non-invertible (or categorical) symmetries. In this paper we
focus on (1+1)d gapped phases with fusion category symmetries. The approach
that we propose uses the Symmetry Topological Field Theory (SymTFT) as a key
input: associated to a field theory in d spacetime dimensions, the SymTFT lives
in one dimension higher and admits a gapped boundary, which realizes the
categorical symmetries. It also admits a second, physical, boundary, which is
generically not gapped. Upon interval compactification of the SymTFT by
colliding the gapped and physical boundaries, we regain the original theory. In
this paper, we realize gapped symmetric phases by choosing the physical
boundary to be a gapped boundary condition as well. This set-up provides
computational power to determine the number of vacua, the symmetry breaking
pattern, and the action of the symmetry on the vacua. The SymTFT also
manifestly encodes the order parameters for these gapped phases, thus providing
a generalized, categorical Landau paradigm for (1+1)d gapped phases. We find
that for non-invertible symmetries the order parameters involve multiplets
containing both untwisted and twisted sector local operators, and hence can be
interpreted as mixtures of conventional and string order parameters. We also
observe that spontaneous breaking of non-invertible symmetries can lead to
vacua that are physically distinguishable: unlike the standard symmetries
described by groups, non-invertible symmetries can have different actions on
different vacua of an irreducible gapped phase. This leads to the presence of
relative Euler terms between physically distinct vacua. We also provide a
mathematical description of symmetric gapped phases as 2-functors from
delooping of fusion category characterizing the symmetry to Euler completion of
2-vector spaces.Comment: 139 pages, v2: corrected an omission in the analysis of TY(Z_N)
gapped phases reported by A. Antinucci, references adde
Non-Invertible Symmetry Webs
Non-invertible symmetries have by now seen numerous constructions in higher
dimensional Quantum Field Theories (QFT). In this paper we provide an in depth
study of gauging 0-form symmetries in the presence of non-invertible
symmetries. The starting point of our analysis is a theory with 0-form
symmetry, and we propose a description of sequential partial gaugings of
sub-symmetries. The gauging implements the theta-symmetry defects of the
companion paper [1]. The resulting network of symmetry structures related by
this gauging will be called a non-invertible symmetry web. Our formulation
makes direct contact with fusion 2-categories, and we uncover numerous
interesting structures such as symmetry fractionalization in this categorical
setting. The complete symmetry web is derived for several groups , and we
propose extensions to higher dimensions. The highlight of this analysis is the
complete categorical symmetry web, including non-invertible symmetries, for 3d
pure gauge theories with orthogonal gauge groups and its extension to arbitrary
dimensions.Comment: 115 page
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