bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolite Detection and Antibacterial Activity of Fungal Endophytic Extracts Isolated from Brotowali (Tinospora crispa) Plants using TLC-Bioautography Assay
Authors: Fathoni A , Hudiyono S. , Budianto E , Cahyana A H , Agusta A
Published: January 2021

Endophytic fungi may be a potent source of bioactive compounds and have a vast repertoire of diverse metabolites. One source of endophytic fungi host plants is a medicinal plant such as Brotowali or Tinospora crispa. Research corresponding to the antibacterial activity of endophytic fungi extracts isolated from T.crispa taken from several regions in West Java has never been reported yet. While antibacterial methods to evaluate their activity as well as to identify the chemical compounds is a TLC-bioautography assay. This research is aimed to investigate the components of endophytic fungal extracts and their antibacterial activity using the TLC-bioautography assay method. In this study, eighty isolates of endophytic fungi have been successfully isolated from plant tissues of T.crispa from several regions in West Java. Antibacterial activity by using TLC (dot-blot) plates revealed that the fungal extracts could inhibit S. aureus (77 extracts) and E. coli (35 extracts) with inhibition zones ranging from 8-30 mm. The endophytic fungi extracts that showed potent antibacterial activity against Gram-positive bacteria (S.aureus) were sixteen extracts, while nine extracts have good inhibition activity against Gram-negative bacteria (E.coli). Among the fungal extracts that have excellent ability against both Gram-positive and negative was namely TcBt1Bd-10 extract. Based on metabolites analysis using the TLC method, the possibility of the chemical compounds that played a role in antibacterial activity of the extracts, including phenolics, flavonoids, alkaloids, and terpenoids.
Candlenut oil encapsulation with Hidroxypropyl Methylcellulose (HPMC) for body lotion application
Authors: Yusri Silvya , Tiffany  , Sutanto Hery
Published: January 2021

Candlenut oil obtained by cold press extraction method was encapsulated in order to preserve the unsaturated fatty acids content from thermal oxidation. The encapsulation of candlenut oil was performed using hydroxypropil mrthylcellulose (HPMC) and maltodextrin as the encapsulating agent due to their filming ability. The solution of wall materials was added with the candlenut oil and emulsified, followed by spray drying process. Three different ratios of oil to wall materials (2:3, 1:1, and 3:2) were evaluated. Based on the peroxide values, encapsulation efficiency, wettability, and moisture content of the microcapsules, the sample with a ratio of 1:1 had better preservation ability towards candlenut oil and therefore used as the main ingredient for body lotion development. Three different concentrations of encapsulated candlenut oil (10%, 6%, and 2%) within the lotion base were observed and analyzed in terms of antioxidant activity by DPPH assay, and overall physical likeness. The result suggested that the wall materials might hinder the reaction between candlenut oil and DPPH radical compounds. The body lotion sample with the lowest content of encapsulated candlenut oil showed the highest antioxidant activity (IC50 = 52.31 ppm). Furthermore, according to the ANOVA test result, there was no significant difference in overall physical likeness between the three samples (p-value ≥ 0.05).
Characterization of Fine Particulate Matters Collected in the Vicinity of Coal-fired Power Plants in Java using ED-XRF
Authors: Lestiani D D , Santoso M , Kusmartini I , Atmodjo D P D , Kurniawati S , Sari D K
Published: January 2021

The number of coal-fired power plant in Java has been increased because of the government policy to supply the electricity in Indonesia to meet the electricity needs. This mega project is assumed to have an impact on the environmental and human health. In this study, the assessment of the air quality near the coal fired power plant has been carried out through characterization of the fine particulate matters. The particulate matters PM2.5 were collected in four sites in the vicinity of coal-fired power plant in Banten, West Java and Central Java, Indonesia. The elemental concentrations in PM2.5 such as Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb have been identified using energy dispersive X-ray Fluorescence-EDXRF. The validation of XRF measurement was applied using standard reference material NIST SRM 2783 Air Particulate on Filter Media. The elemental concentration of PM2.5 especially for the toxic elements as well as the mass and black carbon were compared between four sites. For some sites, the level of elemental concentrations was lower than other industrial sites in Java, due to the sampling was carried out before the commissioning/normal operation. Further and periodical monitoring will be needed to obtain a better comprehensive result to assess the impact of coal power plant to the surrounding environment.
The extraction of antioxidants from Chlorella vulgaris for cosmetics
Authors: Agustina Siti , Aidha Novi Nur , Oktarina Eva
Published: January 2021

Chlorella vulgaris is microalgae that contain chlorophyll as antioxidants, which has been widely used as a functional food. Antioxidants from Chlorella vulgaris also have potential as active ingredients in the cosmetics industry. Nowadays, consumers prefer natural cosmetics because they aren’t harmful to the skin. This study aimed to obtain chlorophyll antioxidants from Chlorella vulgaris and applied it to the cosmetics. The extraction process of antioxidants from Chlorella vulgaris was performed by maceration method, with Chlorella vulgaris concentration variable: 0.01; 0.05 and 0.1% in water as solvent. The antioxidant extracts powdered by spray drying method, with addition of 100 g/L maltodextrin. The observation was conducted on the characteristics of water content, ash content, carbohydrate content, protein content, antioxidant activity, and powder morphology. The extracts powder applied to cosmetics in the form of creams and lotions, then characterized for the antioxidant activity and microbial content. The best antioxidant capacity of extract powder was obtained on Chlorella vulgaris concentration 0.1%, which was 11.83 mg Vit C per 100 g sample. The results of antioxidant capacity in cosmetics as cream and lotion were 4.95 mg Vit. C per 100 g sample (IC50 719.75 mg/ml) and 4.73 mg Vit. C per 100 g sample (IC50 660 mg/ml), respectively. Both of cream and lotion weren’t shown any microbial contamination. Based on this study, Chlorella vulgaris with its antioxidant capacity can be developed as active ingredients for various kinds of cosmetics.
Magnetic convection in a nonuniformly rotating electrically conductive medium in an external spiral magnetic field
Authors: Kopp M I , Tur A V , Yanovsky V V
Published: January 2021

The research is devoted to the stability of convective flow in a nonuniformly rotating layer of an electrically conducting fluid in a spiral magnetic field. The stationary and oscillatory modes of magnetic convection are considered depending on the profile of the angular rotation velocity (Rossby number Ro) and on the profile of the external azimuthal magnetic field (magnetic Rossby number Rb). The non-linear dynamic system of Lorentz type equations is obtained by using the Galerkin method. Numerical analysis of these equations has shown the presence of chaotic behavior of convective flows. The criteria of the occurrence of chaotic movements are found. It depends on the parameters of convection: dimensionless numbers of Rayleigh Ra, Chandrasekhar Q, Taylor Ta, and external azimuthal magnetic field with the Rossby magnetic number Rb for Rayleigh (Ro = −1) and Kepler

(

Ro

=
−
3

/

4
)

profiles of the angular rotation velocity of the medium.
Interfacial interaction and prenucleation at liquid-Al/γ-Al2O3{1 1 1} interfaces
Authors: Fang Changming , Yasmin Sultana , Fan Zhongyun
Published: January 2021

Alumina (α- and γ-Al2O3) particles are formed in liquid Al-Mg alloys during the liquid dealing and cast processes. These native oxide particles have non-trivial influences on the microstructures and properties of the solidified parts, and may act as potential heterogenous nucleation sites during solidification. At present there is still a lack of understanding about the interaction and atomic arrangements at the interfaces between liquid-Al and γ-Al2O3 substrates. Here we investigate the liquid-Al/γ-Al2O3{1 1 1} interfaces by means of ab initio molecular dynamics simulations and electronic structure calculations. We found that the interfacial interaction at the interfaces leads to formation of an ordered terminating Al layer. This newly formed terminating Al layer is positively charged and chemically bonded to the substrate and thus, becomes part of the substrate. Analysis showed that the terminating Al layer contains vacancies and displacements, being atomically rough. The newly-formed Al layer is also structurally coupled with the substrates. These γ-Al2O3 particles are weak templates for nearby liquid to nucleate. The present study sheds some light on the role of alumina particles in grain refinement of Al-based alloys during solidification processing.
Minimization with differential inequality constraints applied to complete Lyapunov functions
Authors: Giesl Peter , Argáez Carlos , Hafstein Sigurdur , Wendland Holger
Published: January 2021

Motivated by the desire to compute complete Lyapunov functions for nonlinear dynamical systems, we develop a general theory of discretizing a certain type of continuous minimization problems with differential inequality constraints. The resulting discretized problems are quadratic optimization problems, for which there exist efficient solution algorithms, and we show that their unique solutions converge strongly in appropriate Sobolev spaces to the unique solution of the original continuous problem. We develop the theory and present examples of our approach, where we compute complete Lyapunov functions for nonlinear dynamical systems.

A complete Lyapunov function characterizes the behaviour of a general dynamical system. In particular, the state space is divided into the chain-recurrent set, where the complete Lyapunov function is constant along solutions, and the part characterizing the gradient-like flow, where the complete Lyapunov function is strictly decreasing along solutions. We propose a new method to compute a complete Lyapunov function as the solution of a quadratic minimization problem, for which no information about the chain-recurrent set is required. The solutions to the discretized problems, which can be solved using quadratic programming, converge to the complete Lyapunov function.
Traffic Distributions and Independence: Permutation Invariant Random Matrices and the Three Notions of Independence
Authors: Male Camille
Published: January 2021

Voiculescu’s notion of asymptotic free independence is known for a large class of random matrices including independent unitary invariant matrices. This notion is extended for independent random matrices invariant in law by conjugation by permutation matrices. This fact leads naturally to an extension of free probability, formalized under the notions of traffic probability.

We first establish this construction for random matrices. We define the traffic distribution of random matrices, which is richer than the

∗

^*

-distribution of free probability. The knowledge of the individual traffic distributions of independent permutation invariant families of matrices is sufficient to compute the limiting distribution of the joint family. Under a factorization assumption, we call traffic independence the asymptotic rule that plays the role of independence with respect to traffic distributions. Wigner matrices, Haar unitary matrices and uniform permutation matrices converge in traffic distributions, a fact which yields new results on the limiting

∗

^*

-distributions of several matrices we can construct from them.

Then we define the abstract traffic spaces as non-commutative probability spaces with more structure. We prove that at an algebraic level, traffic independence in some sense unifies the three canonical notions of tensor, free and Boolean independence. A central limiting theorem is stated in this context, interpolating between the tensor, free and Boolean central limit theorems.
Fences, their endpoints, and projective Fraïssé theory
Authors: Basso Gianluca , Camerlo Riccardo
Published: January 2021

We introduce a new class of compact metrizable spaces, which we call fences, and its subclass of smooth fences. We isolate two families

F

,

F

0

\mathcal {F}, \mathcal {F}_{0}

of Hasse diagrams of finite partial orders and show that smooth fences are exactly the spaces which are approximated by projective sequences from

F

0

\mathcal {F}_{0}

. We investigate the combinatorial properties of Hasse diagrams of finite partial orders and show that

F

,

F

0

\mathcal {F}, \mathcal {F}_{0}

are projective Fraïssé families with a common projective Fraïssé limit. We study this limit and characterize the smooth fence obtained as its quotient, which we call a Fraïssé fence. We show that the Fraïssé fence is a highly homogeneous space which shares several features with the Lelek fan, and we examine the structure of its spaces of endpoints. Along the way we establish some new facts in projective Fraïssé theory.
Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial
Authors: Lin Yu-Shiuan , Weibel Janine , Landolt Hans-Peter , Santini Francesco , Meyer Martin , Brunmair Julia , Meier-Menches Samuel M , Gerner Christopher , Borgwardt Stefan , Cajochen Christian , Reichert Carolin
Published: January 2021

Caffeine is commonly used to combat high sleep pressure on a daily basis. However, interference with sleep–wake regulation could disturb neural homeostasis and insufficient sleep could lead to alterations in human gray matter. Hence, in this double-blind, randomized, cross-over study, we examined the impact of 10-day caffeine (3 × 150 mg/day) on human gray matter volumes (GMVs) and cerebral blood flow (CBF) by fMRI MP-RAGE and arterial spin-labeling sequences in 20 habitual caffeine consumers, compared with 10-day placebo (3 × 150 mg/day). Sleep pressure was quantified by electroencephalographic slow-wave activity (SWA) in the previous nighttime sleep. Nonparametric voxel-based analyses revealed a significant reduction in GMV in the medial temporal lobe (mTL) after 10 days of caffeine intake compared with 10 days of placebo, voxel-wisely adjusted for CBF considering the decreased perfusion after caffeine intake compared with placebo. Larger GMV reductions were associated with higher individual concentrations of caffeine and paraxanthine. Sleep SWA was, however, neither different between conditions nor associated with caffeine-induced GMV reductions. Therefore, the data do not suggest a link between sleep depth during daily caffeine intake and changes in brain morphology. In conclusion, daily caffeine intake might induce neural plasticity in the mTL depending on individual metabolic processes.
Evolution of Cefiderocol Non-Susceptibility inPseudomonas aeruginosain a Patient Without Previous Exposure to the Antibiotic
Authors: Streling Ana Paula , Al Obaidi Mohanad M , Lainhart William D , Zangeneh Tirdad , Khan Ayesha , Dinh An Q , Hanson Blake , Arias Cesar A , Miller William R
Published: January 2021

We report the emergence of non-susceptibility to cefiderocol from a subpopulation of Pseudomonas aeruginosa recovered from a patient without history of cefiderocol exposure. Whole genome sequencing identified mutations in major iron transport pathways previously associated with cefiderocol uptake. Susceptibility testing should be performed before therapy with siderophore cephalosporins.
Long-term outcome after the arterial switch operation: 43 years of experience
Authors: van der Palen Roel L F , Blom Nico A , Kuipers Irene M , Rammeloo Lukas A J , Jongbloed Monique R M , Konings Thelma C , Bouma Berto J , Koolbergen David R , Hazekamp Mark G
Published: January 2021

OBJECTIVES

The objective of this study was to assess our 43-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) by analysing cardiac outcome measures (hospital and late mortality, reoperations and catheter interventions, significant coronary artery obstruction) and to identify risk factors for reoperation and catheter interventions.

METHODS

A total of 490 patients who underwent ASO for TGA from 1977 to 2020 were included in this retrospective, single-centre study. Data on reoperation and catheter intervention of hospital survivors were estimated by the Kaplan–Meier method and compared using a long-rank test. Risk factors for reoperation and/or catheter intervention were assessed by multivariate Cox regression analysis.

RESULTS

Hospital mortality occurred in 43 patients (8.8%), late death in 12 patients (2.9%) and 43 patients were lost to follow-up. Median follow-up time of 413 hospital survivors was 15.6 (interquartile range 7.0–22.4) years. Reoperations were performed in 83 patients (117 reoperations). Neoaortic valve regurgitation with root dilatation was the second most common indication for reoperation (15/83 patients, 18.1%) after right ventricular outflow tract obstruction (50/83 patients, 60.2%). Risk factors for any reoperation on multivariable analysis were: TGA morphological subtype [TGA with ventricular septal defect: hazard ratio (HR) = 1.99, 95% confidence interval (CI) 1.18–3.36; P = 0.010 and Taussig-Bing: HR = 2.17, 95% CI 1.02–4.64; P = 0.045], aortic arch repair associated with ASO (HR = 3.03, 95% CI 1.62–5.69; P = 0.001) and a non-usual coronary artery anatomy (HR = 2.41, 95% CI 1.45–4.00; P = 0.001). One hundred and one catheter interventions were performed in 54 patients, usually for relief of supravalvular pulmonary stenosis (44/54 patients, 81.5%) or arch obstruction (10/54 patients, 18.5%). Main risk factor for catheter intervention on multivariable analysis was aortic arch repair associated with ASO (HR = 2.95, 95% CI 1.37–6.36; P = 0.006). Significant coronary artery stenosis was relatively uncommon (9/413 patients, 2.2%) but may be underrepresented.

CONCLUSIONS

Patients after ASO typically have good long-term clinical outcomes but reoperations and interventions remain necessary in some patients. Neoaortic valve regurgitation with root dilatation is the second most common indication for reoperation after right ventricular outflow tract obstruction and an increasing need for neoaortic valve and root redo surgery in future is to be expected.
The relationship between blood pressure and risk of atrial fibrillation: a Mendelian randomization study
Authors: Georgiopoulos Georgios , Ntritsos Georgios , Stamatelopoulos Kimon , Tsioufis Costas , Aimo Alberto , Masi Stefano , Evangelou Evangelos
Published: January 2021

Aims

Observational studies suggest elevated blood pressure (BP) as the leading risk factor for incident atrial fibrillation (AF), but whether this relationship is causal remains unknown. In this study, we used Mendelian randomization (MR) to investigate the potential causal association of BP levels with the risk of developing AF.

Methods and results

Genetic variants associated with the BP traits were retrieved from the International Consortium of Blood Pressure-Genome Wide Association Studies (N = 299 024). From 901 reported variants, 894 were assessed in a dedicated Genome-Wide Association Study of AF genetics, including >1 000 000 subjects of European ancestry. We used two-sample MR analyses to examine the potential causal association of systolic BP (SBP) and diastolic BP (DBP) as well as of pulse pressure (PP) with AF. MR analysis identified a potentially causal association between AF and SBP [odds ratio (OR): 1.018 per 1 mmHg increase, 95% confidence interval (CI): 1.012–1.024, P < 0.001], DBP (OR: 1.026, 95% CI: 1.016–1.035, P < 0.001), and PP (OR: 1.014, 95% CI: 1.001–1.028, P = 0.033). These findings were robust in sensitivity analyses, including the MR-Egger method and the MR pleiotropy residual sum and outlier test (MR-PRESSO). The causal relationship of BP and AF did not change when single-nucleotide polymorphisms associated with possible confounders (i.e. coronary artery disease and obesity) of the causal relationship were excluded.

Conclusions

The association between increased BP levels and the risk of AF is likely causal and applies for different BP indices. Independently from other risk factors, optimal BP control might represent an important therapeutic target for AF prevention in the general population.
THE GENETIC STRUCTURE OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. XVI. EXCESS OF ADDITIVE GENETIC VARIANCE OF VIABILITY
Authors: Mukai Terumi , Nagano Shuji
Published: January 2021

About 500 second and 500 third chromosomes were extracted, using the marked inversion technique, from the Orlando-Lake Placid, Florida, population. From the experiments using these chromosomes, the following findings were obtained: (1) The frequencies of lethal-carrying chromosomes were 0.37 in the second and 0.55 in the third chromosomes. (2) The size of the population was estimated to be effectively infinite, on the basis of the allelism rate of lethal-carrying chromosomes. (3) The detrimental and lethal loads for viability were, respectively, 0.40 and 0.45 for the second and 0.52 and 0.78 for the third chromosomes. Consequently, the detrimental to lethal load ratio is 0.90 for the second and 0.67 for the third chromosomes. (4) Lethal genes were shown to be deleterious when heterozygous. (5) The average degree of dominance for mildly deleterious genes (viability polygenes) was estimated to be nearly 0.5, although the confidence interval is large. (6) Additive (σ2  A) and dominance (σ2  D) variances of viability were estimated by using a partial diallel cross method. The results were (see PDF) and (see PDF) for the second chromosomes. (7) Environmental variances of viability were estimated. The result indicates that the heterozygotes are more homeostatic than the homozygotes. The most striking finding is that the additive variance is larger than expected on the classical hypothesis from the detrimental load. Several possible explanations for the discrepancy are offered. The most likely cause, we suggest, is genotype-environment interaction (diversifying selection) acting on viability polygenes. Overdominance is inconsistent with the low dominance variance, and frequency-dependent selection also appears unlikely as an explanation.
GENETIC ANALYSIS OF THREE DOMINANT FEMALE-STERILE MUTATIONS LOCATED ON THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Busson D , Gans M , Komitopoulou K , Masson M
Published: January 2021

Three dominant female-sterile mutations were isolated following ethyl methanesulfonate (EMS) mutagenesis. Females heterozygous for two of these mutations show atrophy of the ovaries and produce no eggs (ovoD  1) or few eggs (ovoD  2); females heterozygous for the third mutation, ovoD  3, lay flaccid eggs. All three mutations are germ line-dependent and map to the cytological region 4D-E on the X chromosome; they represent a single allelic series. Two doses of the wild-type allele restore fertility to females carrying ovoD  3 and ovoD  2, but females carrying ovoD  1 and three doses of the wild-type allele remain sterile. The three mutations are stable in males but are capable of reversion in females; reversion of the dominant mutations is accompanied by the appearance, in the same region, of a recessive mutation causing female sterility. We discuss the utility of these mutations as markers of clones induced in the female germ line by mitotic recombination as well as the nature of the mutations.
HOMOEOSIS IN DROSOPHILA: A NEW ENHANCER OF POLYCOMB AND RELATED HOMOEOTIC MUTATIONS
Authors: Sato Takashi , Russell Michael A , Denell R E
Published: January 2021

A new recessive lethal mutation in Drosophila melanogaster, Enhancer of Polycomb [E(Pc)], and chromosomal deficiencies lacking this locus act as dominant enhancers of the Polycomb mutant syndrome in adults. Thus, although E(Pc)/+ flies are phenotypically normal, this locus is haplo-abnormal with respect to its effect on the Polycomb phenotype. Recombinational and deficiency mapping localize the E(Pc) locus on chromosome 2 proximally and very closely linked (∼0.1 map unit) to the engrailed gene. E(Pc) enhances the expression of all Polycomb point mutations examined including that of a deficiency, indicating that this interaction does not depend on the presence of an altered Polycomb gene product. In several respects the mutations extra sex comb, lethal(4)29, and Polycomblike resemble those at the Polycomb locus. In the presence of E(Pc), recessive alleles of extra sex comb and lethal(4)29 are rendered slightly pseudodominant, and the homoeotic effects of Polycomblike heterozygotes are also enhanced. However, E(Pc) does not affect the expression of dominant mutations within the Bithorax gene complex (Cbx) or Antennapedia gene complex (AntpNs, Antp  73b, Antpscx, AntpEfW15, ScrMsc) which give homoeotic transformations resembling those of the Polycomb syndrome. Available evidence from the study of adult phenotypes suggests that mutations at E(Pc) do not result in homoeotic changes directly but instead modify the expression of a specific set of functionally related homoeotic variants.
EVIDENCE FOR DUPLICATION OF THE STRUCTURAL GENES CODING PLASTID AND CYTOSOLIC ISOZYMES OF TRIOSE PHOSPHATE ISOMERASE IN DIPLOID SPECIES OF CLARKIA
Authors: Pichersky E , Gottlieb L D
Published: January 2021

Formal genetic analyses of the mode of inheritance of the multiple plastid and cytosolic isozymes of triose phosphate isomerase (TPI, EC 5.3.1.1) in annual diploid species of Clarkia (Onagraceae), native to California, suggest that each set of isozymes is specified by duplicate structural genes. In contrast, most diploid plant species possess one plastid and one cytosolic TPI isozyme each coded by a single locus. Linkage tests revealed that the two genes coding the plastid TPIs assort independently. Although the number of individuals sampled per species was small, the plastid isozymes were electrophoretically more variable than the cytosolic isozymes. The two gene duplications are the first reported that characterize an entire plant genus. Initial electrophoretic surveys of TPI in other genera of Onagraceae revealed that the duplication of the gene coding the plastid isozyme is apparently restricted to Clarkia, whereas that of the gene coding the cytosolic isozyme is present in most genera of the family. The separate phylogenetic distributions of the two duplications suggest that the processes that gave rise to them were unrelated.
EVOLUTIONARY RELATIONSHIP OF DNA SEQUENCES IN FINITE POPULATIONS
Authors: Tajima Fumio
Published: January 2021

With the aim of analyzing and interpreting data on DNA polymorphism obtained by DNA sequencing or restriction enzyme technique, a mathematical theory on the expected evolutionary relationship among DNA sequences (nucleons) sampled is developed under the assumption that the evolutionary change of nucleons is determined solely by mutation and random genetic drift. The statistical property of the number of nucleotide differences between randomly chosen nucleons and that of heterozygosity or nucleon diversity is investigated using this theory. These studies indicate that the estimates of the average number of nucleotide differences and nucleon diversity have a large variance, and a large part of this variance is due to stochastic factors. Therefore, increasing sample size does not help reduce the variance significantly. The distribution of sample allele (nucleomorph) frequencies is also studied, and it is shown that a small number of samples are sufficient in order to know the distribution pattern
ISOGENIC STRAINS OF PHYCOMYCES BLAKESLEEANUS SUITABLE FOR GENETIC ANALYSIS
Authors: Alvarez M I , Eslava A P
Published: January 2021

The progeny of crosses between wild-type strains of Phycomyces usually do not exhibit all of the expected genotypes from meiosis. By backcrossing, we have isolated a new (+) mating-type strain, A56, which is nearly isogenic with the (-) wild-type NRRL1555 commonly used in Phycomyces research. Tetrad analysis of the backcrosses shows that meiosis becomes more regular as the parental (+) and (-) strains become more isogenic. In our two-factor crosses with unlinked markers, the regularity of meiosis is measured as the percent of reciprocal ditypes plus tetratypes in the progeny. We have shown that this percentage increases from about 15% for crosses between nonisogenic parents to 90% in the eighth backcross. The results indicate that routine, reliable recombination analyses are possible in P. blakesleeanus.
GENETIC DIFFERENTIATION AMONG KARYOTYPIC FORMS OF THE BLACK RAT, RATTUS RATTUS
Authors: Baverstock P R , Adams M , Maxson L R , Yosida T H
Published: January 2021

The black rat, Rattus rattus, consists of five karyotypic forms—2n = 42 (high C-banding); 2n = 42 (low C-banding); 2n = 40; 2n = 38; 2n = 42 Mauritius. Here, we use isozyme electrophoresis and microcomplement fixation to elucidate the genetic distance and phylogenetic relationship among each of the various karyotypic forms of R. rattus and R. norvegicus. The results show that (1) the 2n = 42 Mauritius black rat (2n = 42Mau) is genetically very similar to the 2n = 38 form, suggesting that this island population has undergone very rapid chromosomal evolution; (2) the 2n = 40 form from the highlands of Sri Lanka is genetically distinct from the 2n = 38 form from the lowlands; the genetic difference is probably insufficient, however, to prevent future introgression; (3) the level of genetic differentiation occurring between the 2n = 42 forms on the one hand and the 2n = 38, 2n = 40 and 2n = 42 Mau forms on the other support the hybrid incompatability data in suggesting that the two groups are either full species or incipient species; (4) in contrast to data from amino acid composition of transferrin and from restriction endonuclease digests of mtDNA, the present data suggest that the various karyotypic forms of R. rattus are phylogenetically more closely related to each other than any is to R. norvegicus, and that they are related by a series 2n = 42 → 2n = 40 → 2n = 38; (5) the R. rattus/R. norvegicus divergence occurred 2-8 million years ago, whereas the various chromosomal forms of R. rattus diverged over the last 4 million years.
SUPPRESSOR SYSTEMS OF SEGREGATION DISTORTER (SD) CHROMOSOMES IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER
Authors: Hiraizumi Yuichiro , Thomas Anita M
Published: January 2021

Several natural populations of D. melanogaster were investigated for the presence (or absence) of the Segregation Distorter (SD) chromosomes and their suppressor systems. The SD chromosomes were found, at frequencies of a few percent, in two independent samples taken in different years from a Raleigh, North Carolina, population, whereas no SD chromosomes were found in samples collected from several populations in Texas. The populations in these localities were found to contain suppressor X chromosomes in high frequencies (75% or higher). They also contained relatively low frequencies of partial suppressor or insensitive second chromosomes of varying degrees, but completely insensitive second chromosomes were practically absent in all populations examined. The frequencies of suppressor X chromosomes, as well as those of the partially insensitive or suppressor second chromosomes, were the same among the populations investigated. This suggests the possibility that the development of a suppressor system of SD in a population could be independent of the presence of an SD chromosome. Segregation distortion appeared to be occurring in natural genetic backgrounds, but the degree of distortion varied among males of different genotypes. There were many instances in which the SD chromosomes showed transmission frequencies from their heterozygous male parents that were smaller than 0.6 and, in several cases, even smaller than 0.5. The presence of a recessive suppressor, or suppressors, of SD in natural populations was suggested.
NEW HYBRIDS WITH D GENOME WHEAT RELATIVES
Authors: Zhao Y H , Kimber G
Published: January 2021

The cytology of nine new D genome hybrids involving Triticum syriacum, Triticum ventricosum, Triticum cyclindricum, Triticum juvenale, Triticum crassum, Triticum tauschii and Triticum aestivum is described. The calculation of numerical values of the relative affinity and the patterns of chromosome pairing indicate that the D genome in T. syriacum and T. juvenale may have been substantially modified and that of T. crassum somewhat modified from that of the diploid progenitor, T. tauschii.
AUTOREGULATORY FUNCTIONING OF A DROSOPHILA GENE PRODUCT THAT ESTABLISHES AND MAINTAINS THE SEXUALLY DETERMINED STATE
Authors: Cline Thomas W
Published: January 2021

Sxl appears to head a regulatory gene hierarchy that controls Drosophila sexual dimorphism in response to the X chromosome/autosome balance. Only XXAA cells normally have Sxl  + activity. It maintains both the female morphogenetic sequence and a level of X-linked dosage-compensated gene expression compatible with diplo-X cell survival. In the absence of this activity, male sexual development and dosage-compensated gene hyperactivation ensure. Loss-of-function Sxl mutations generally have female-specific lethal effects caused by upsets in dosage compensation. New female-viable Sxl mutant alleles and combinations which lack Sxl's female sex determination function, yet still provide sufficient dosage compensation function for diplo-X survival, are described here. Consequently, such mutants cause genotypic females to develop as phenotypic males. Some of these sex-transforming Sxl mutants do not require the maternally produced da  + activity that is normally essential for the functioning of zygotic Sxl alleles. In this paper, products of these unusual alleles are shown to act in trans to induce the expression of zygotic Sxl  + alleles that would otherwise be unable to function due to a lack of maternal da  + activity. This result indicates a third function for Sxl  + product: a positive autoregulatory role. Controls for the autoregulation experiments demonstrated the sex-trans-forming epigenetic effect of the da mutation for the first time in diploids. In these experiments the female-specific zygotic lethal effects that normally would have accompanied loss of maternal da  + activity were suppressed by mutations known to block dosage-compensation gene hyperactivation-the autosomal, male-specific lethals. Three types of abnormal sexual phenotypes were produced in the experiments described here, each with important implications for the mechanism of sex determination: (1) a true intersex phenotype produced by one particular Sxl allele shows that Sxl  + must be involved in the cellular response to the X/A balance rather than in its establishment; (2) a maternally induced, female-sterile phenotype indicates that either the process of autoregulation or the mutants used to demonstrate it are tissue specific and (3) a mosaic intersexual phenotype whose character implies that the Sxl  + activity level is set early in development, both by the da  +-mediated X/A balance signal and by autoregulation, and is maintained subsequently in a cell autonomous fashion, independent of the initiating X/A balance signal. Thus, this study supports the view that sex determination is truly determinative in the standard developmental sense, and that Sxl is the carrier of the sexually determined state.
LINKAGE RELATIONSHIPS OF NINE ENZYME LOCI IN SUNFISHES (LEPOMIS; CENTRARCHIDAE)
Authors: Pasdar Manijeh , Philipp David P , Whitt Gregory S
Published: January 2021

Linkage relationships of nine enzyme loci; aconitase (Acon), esterase (Est), glucosephosphate isomerase A and B (Gpi), glycerate-2-dehydrogenase (G2dh), malic enzyme (Me), phosphoglycerate kinase (Pgk), phosphoglucomutase (Pgm) and superoxide dismutase (Sod), were investigated in sunfishes (Lepomis, Centrarchidae). Reciprocal F1 hybrids produced from crosses between green sunfish (Lepomis cyanellus) and redear sunfish (L. microlophus) were backcrossed with each of the two parental species. A three-point linkage map comprising G2dh, Pgk and Sod is reported. The frequencies of recombination between G2dh and Pgk and between Pgk and Sod are estimated as 45.3 and 24.7%. The remaining six loci assort independently. Possible linkage conservation and homology of this linkage group with those of other vertebrate species are discussed.
GENETICS OF CHLAMYDOMONAS REINHARDTII DIPLOIDS. II. THE EFFECTS OF DIPLOIDY AND ANEUPLOIDY ON THE TRANSMISSION OF NON-MENDELIAN MARKERS
Authors: Eves Eva M , Chiang Kwen-Sheng
Published: January 2021

The transmission of two non-Mendelian drug resistance markers has been studied in crosses of Chlamydomonas reinhardtii involving diploids and aneuploids with different mating type genotypes. Under normal laboratory conditions for gametogenesis, mating and zygote maturation, the transmission pattern of the non-Mendelian markers sr-u-1 (resistance to streptomycin) and spr-u-1-27-3 (resistance to spectinomycin) is primarily determined by the mating type genotypes of the parental cells. Our results confirm and expand an earlier observation suggesting that an apparent codominant function of the female (mt  +) allele in regulating chloroplast gene transmission in meiosis appears to be distinct and separate from its recessive function in regulating mating behavior. The chloroplast DNA complement (as indexed by the number of extranuclear DNA-containing bodies) may exert a secondary effect on the transmission of these markers. Within a mating type group (mt+/mt- or mt-/mt-) a cell line with more chloroplast DNA tended to transmit its non-Mendelian markers more frequently than a cell line with less chloroplast DNA.
DEVIATIONS FROM HARDY-WEINBERG PROPORTIONS: SAMPLING VARIANCES AND USE IN ESTIMATION OF INBREEDING COEFFICIENTS
Authors: Robertson Alan , Hill William G
Published: January 2021

An analysis is made of the distribution of deviations from Hardy-Weinberg proportions with k alleles and of estimates of inbreeding coefficients (f) obtained from these deviations.—If f is small, the best estimate of f in large samples is shown to be 2∑i(Tii/Ni)/(k - 1), where Tii is an unbiased measure of the excess of the ith homozygote and Ni the number of the ith allele in the sample [frequency = Ni/(2N)]. No extra information is obtained from the Tij, where these are departures of numbers of heterozygotes from expectation. Alternatively, the best estimator can be computed from the Tij, ignoring the Tii. Also (1) the variance of the estimate of f equals 1/(N(k - 1)) when all individuals in the sample are unrelated, and the test for f = 0 with 1 d.f. is given by the ratio of the estimate to its standard error; (2) the variance is reduced if some alleles are rare; and (3) if the sample consists of full-sib families of size n, the variance is increased by a proportion (n - 1)/4 but is not increased by a half-sib relationship.—If f is not small, the structure of the population is of critical importance. (1) If the inbreeding is due to a proportion of inbred matings in an otherwise random-breeding population, f as determined from homozygote excess is the same for all genes and expressions are given for its sampling variance. (2) If the homozygote excess is due to population admixture, f is not the same for all genes. The above estimator is probably close to the best for all f values.
ISOLATION OF ANEUPLOID-GENERATING MUTANTS OF ASPERGILLUS NIDULANS, ONE OF WHICH IS DEFECTIVE IN INTERPHASE OF THE CELL CYCLE
Authors: Upshall A , Mortimore I D
Published: January 2021

A method is described for isolating mutants potentially defective in loci involved in mitotic chromosome segregation. Conditional lethal, heat-sensitive (42°) mutants were assayed at a subrestrictive temperature of 37° for an inflated production of colonies displaying phenotypes and behavior patterns of whole chromosome aneuploids. Of 14 mutants, three showed specificity for one disomic phenotype, whereas 11 generated colonies mosaic for different aneuploid phenotypes. This latter group is designated hfa (high frequency of aneuploid). For ten of the 11 mutants temperature sensitivity and aneuploid production cosegregated, indicating a single mutation in each. These mutations were recessive and nonallelic. Analysis was concentrated on the hfaB3 mutation which is mapped to chromosome VI tightly linked to the methB and tsB loci. The disruptive influence of hfaB3 on mitosis at 37° was shown by (1) ploidy and whole chromosome-type segregation of markers in the breakdown sectors of phenotypically aneuploid colonies obtained from multiply marked homozygous hfaB3 disploids; (2) a high frequency of haploid and nondisjunctional diploid segregants among spontaneous yellow-spored parasexual recombinants taken from green-spored homozygous hfaB3 diploids. The mutation had no effect on meiotic chromosome segregation at 37°. The single interphase nucleus in germlings at 42°, coupled with changes in the mitotic index in temperature exchange experiments, showed hfaB3 to arrest the cell cycle in interphase at restrictive temperature. A conclusion drawn is that the hfaB gene product is required both for entry into mitosis and for normal chromosome segregation in dividing nuclei.
MULTIPLE-LOCUS HETEROZYGOSITY AND THE PHYSIOLOGICAL ENERGETICS OF GROWTH IN THE COOT CLAM, MULINIA LATERALIS, FROM A NATURAL POPULATION
Authors: Garton David W , Koehn Richard K , Scott Timothy M
Published: January 2021

The relationship between individual energy budgets and multiple-locus heterozygosity at six polymorphic enzyme loci was examined in Mulinia lateralis. Energy budgets were determined by measuring growth rates, rates of oxygen consumption, ammonia excretion and clearance rates. Enzyme genotypes were determined using starch gel electrophoresis. Growth rate and net growth efficiency (the ratio of energy available for growth to total energy absorbed) increased with individual heterozygosity. The positive relationship between observed growth and multiple-locus heterozygosity was associated with a negative relationship between routine metabolic costs and increasing heterozygosity. Reduction in routine metabolic costs explained 60% of the observed increased growth of more heterozygous individuals. When routine metabolic costs were standardized for differences in feeding rates, these standard metabolic costs explained 97% of the differences in growth rate. Lower standard metabolic costs, associated with increasing heterozygosity, have been proposed as a physiological mechanism for the relationship between multiple-locus heterozygosity and growth rate that has been reported for a variety of organisms, ranging in diversity from aspens to humans. This study demonstrates that reduction of standard metabolic costs, at least in clams, accounts for virtually all of the differences in growth rate among individuals of differing heterozygosity.
MUTANTS WITH ALTERED Ca2+-CHANNEL PROPERTIES IN PARAMECIUM TETRAURELIA: ISOLATION, CHARACTERIZATION AND GENETIC ANALYSIS
Authors: Hinrichsen Robert D , Saimi Yoshiro , Kung Ching
Published: January 2021

Dancers are a group of mutants in Paramecium tetraurelia whose Ca2+ current inactivates poorly and are likely to be defective in the structure of their Ca2+ channels. These mutants show prolonged backward swimming in response to K+ and Ba2+ in the medium and were selected by this property in a galvanotactic trough. The dancer mutants are semidominant, and all isolated mutants belong to one complementation group; they are not allelic to any of the previously isolated behavioral mutants of P. tetraurelia. The phenotypic change from the homozygous parent to heterozygous F1 generation takes three to five fissions. There is no evidence of a cytoplasmic factor capable of converting the dancer to the wild-type phenotype, as has been demonstrated in the mutants pawn and cnr. We suggest that the dancer locus is a structural gene for the Ca2+ channel.
DEVELOPMENTAL GENETICS OF THE 2E-F REGION OF THE DROSOPHILA X CHROMOSOME: A REGION RICH IN "DEVELOPMENTALLY IMPORTANT" GENES
Authors: Perrimon Norbert , Engstrom Lee , Mahowald Anthony P
Published: January 2021

We have analyzed the 2E1-3A1 area of the X chromosome with special attention to loci related to embryogenesis. Published maps indicate that this chromosomal segment contains ten bands. Our genetic analysis has identified 11 complementation groups: one recessive visible (prune), two female steriles and eight lethals. One of the female sterile loci is fs(1)k10 for which homozygous females produce both egg chambers and embryos with a dorsalized morphology. The second female sterile is the paternally rescuable fs(1) pecanex in which unrescued embryos have a hypertrophic nervous system. Of the eight lethal complementation groups two are recessive embryonic lethals: hemizygous giant (gt) embryos possess segmental defects, and hemizygous crooked neck (crn) embryos exhibit a twisted phenotype. Analysis of these mutations in the female germ line indicates that gt does not show a maternal effect, whereas normal activity of crn is required for germ cell viability. Analysis of the maternal effect in germ line clones of the remaining six recessive lethal complementation groups indicates that four are required for germ cell viability and one produces ambiguous results for survival of the germ cells. The remaining, l(1) pole hole, is a recessive early pupal lethal in which embryos derived from germ line clones and lacking wild-type gene activity exhibit the "torso" or "pole hole" phenotype.
STUDIES ON THE MECHANISM OF HETEROCHROMATIC POSITION EFFECT AT THE ROSY LOCUS OF DROSOPHILA MELANOGASTER
Authors: Rushlow C A , Bender W , Chovnick A
Published: January 2021

Experiments are described that extend the characterization of position effect variants of the rosy locus and test possible mechanisms of heterochromatic position effect.—Rosy position effect variants exhibit a variegated phenotype with respect to xanthine dehydrogenase activity in malpighian tubules.—The breakpoints of the position effect mutations are located on the DNA map of the rosy region outside of the rosy locus DNA; ryps  1136 is located in the DNA of the l(3)S12 gene immediately proximal to rosy, whereas ryps  1149 is located some 15 kb distal to rosy in the pic locus.—Southern blot experiments are described that test and reject the notion that heterochromatic position effect results from underreplication of the position-affected gene. Rather, the results of Northern blots serve to direct attention to position effect as a defect in transcription.—Histone region deletion heterozygosity and butyrate-feeding experiments failed to exhibit specific suppression of position effect at the rosy locus.
INHERITANCE OF ADRENAL PHENYLETHANOLAMINE N-METHYLTRANSFERASE ACTIVITY IN THE RAT
Authors: Stolk Jon M , Vantini Guido , Guchhait Ras B , Hurst Jeffrey H , Perry Bruce D , U'Prichard David C , Elston Robert C
Published: January 2021

Phenylethanolamine N-methyltransferase (PNMT) is the enzyme that catalyzes the S-adenosyl-l-methionine-dependent methylation of (-)norepinephrine to (-)epinephrine in the adrenal medulla. Adrenal PNMT activity is markedly different in two highly inbred rat strains; enzyme activity in the F344 strain is more than fivefold greater than that in the Buf strain. Initial characterization of the enzyme in the two inbred strains reveals evidence for catalytic and structural differences, as reflected in dissimilar K  m values for the cosubstrate (S-adenosyl-l-methionine) and prominent differences in thermal inactivation curves. To assess adrenal PNMT activity in an F344 × Buf pedigree, we employed a statistical procedure to test for one- and two-locus hypotheses in the presence of within-class correlations due to cage or litter effects. The PNMT data in the pedigree are best accounted for by segregation at a simple major locus superimposed upon a polygenic background; data obtained from the biochemical studies suggest that the major locus is a structural gene locus.