bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant activity of butanolic extract from Madang Gatal (Schima wallichii Choisy) Leaves
Authors: Widiyarti Galuh , Widodo Ginanjar , Sampora Yulianti , Lotulung Puspa Dewi , Hanafi Muhammad
Published: January 2021

Antioxidant activity of the butanolic extract from Madang Gatal (Schima wallichii Choisy) leaves was studied in the research. Antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical oxidation method. Furthermore, the extract was purified using column chromatography to yield 4 partially purified fractions (B1-B4). The extract and B2 fraction possess strong antioxidant action with IC50 value 12.55 and 24.50 μg/ml, respectively. The B1 and B3 fractions have moderate antioxidant activity with IC50 value 70.55 and 90.26 μg/ml, while B4 was not active as antioxidant with IC50 value of 228.28. The target compound of the fraction most active as an antioxidant (B2) was separated by preparative Thin Layer Chromatography (TLC). The isolate was then identified using Fourier Transform Infra-Red (FTIR) and Liquid Chromatography Mass Spectroscopy (LCMS). The IR spectra displayed that the bioactive compound of B2 was predicted as flavonoid with MS 290.25 g/mol. The major compound contained in a putative compound known as catechin with an IC50 value was 17.97 μg/ml.
Synthesis layered material of MnO2and TiO2as the support of molybdenum catalyst for bio-crude oil upgrading process
Authors: Rinaldi N , Dwiatmoko A A , Kristiani A
Published: January 2021

Layered materials are attractive for many applications because of their unique structure consisting of stacked sheets that can be controlled and modified. In this work, various synthetic layered materials (SLMs)i.e., Na-MnO2, H-MnO2, and Cs-TiO2have been successfully prepared as the support for molybdenum (Mo)-based catalyst and applied for bio-crude oil hydrodeoxygenation (HDO) process. A commercial Mo/Al2O3catalysts will also be utilized as a benchmark. The physical and chemical properties of the catalysts were characterized by using an X-ray diffractometer, X-ray fluorescence, surface area analyzer, NH3-temperature-programmed desorption, and scanning electron microscopy. The characterization results showed that the interlayer ion exchange of Na+ions with H+ions was successful for MnO2support. The impregnation of the MoO3into SLMs increased the surface area, pore-volume, average pore size, and total acidity. The HDO of bio-crude oil using MoO3/Na-MnO2catalyst produced a higher HHV value of 38.75 MJ/Kg and a DOD value of 82.75% compared to other prepared catalysts or even the MoO3commercial catalyst.
Effect of Ag and Mn doping for methylene blue photodegradation performance
Authors: Jessica  , Ibadurrohman M , Slamet
Published: January 2021

Currently, wastewater management is ineffective, operationally expensive, and difficult to be implemented in Indonesia. The photocatalyst is a technology that may answer this problem. Titania (TiO2) is a high-activity, inexpensive, stable, and non-toxic photocatalyst material. However, TiO2 has large band-gap energy and rapid recombination. In this research, TiO2 was doped by Ag (a noble metal) and Mn (a transition metal) to compare the performance of photocatalysts in organic pollutant degradation, using methylene blue. Ag/TiO2 catalyst was synthesized by Photo Assisted Deposition (PAD) method, while Mn/TiO2 was synthesized by impregnation method. The physicochemical properties of both catalysts were assessed by SEM-EDX and UV-Vis DRS. SEM-EDX indicated that both methods successfully doped Ag and Mn into TiO2. Besides, UV-Vis DRS confirmed the presence of metal dopants that caused the narrowing of the bandgap. Ag/TiO2 catalyst increased the degradation of methylene blue by up to 97% in 30 minutes. Meanwhile, the Mn/TiO2 catalyst inhibited the degradation of methylene blue. The increased activity by Ag dopants is due to the Localized Electromagnetic Field (LEMF) and Schottky barrier phenomena which increase charge separation. Meanwhile, decreased activity by Mn dopants is due to the shading effect and Mn electronic structure that can facilitate recombination at high loading. Ag/TiO2 catalyst also improved photodegradation performance of TiO2 when irradiated by visible light.
Saturation time test of membrane to supply clean water using reverse osmosis with pressure stage in rejection
Authors: Zakwan Muhammad , Prayoga Anton , Bismo Setijo
Published: January 2021

The tsunami in Pandeglang had resulted in high salinity of water and caused water scarcity. Furthermore, there were difficulties accessing water due to dry season in 4 sub-districts in Pandeglang in 2019. Reverse osmosis (RO) is a suitable technology to provide clean water, however, the advanced research is required to undrestand the method and determine the optimum pressure of multi-pass RO to produce clean water with a long saturation time of the membrane. The experimental research used RO multi-pass was operated in Tanjung Lame by various pressures 6-3, 6-4, and 7-4 on the first and second stage to observe the effect of flux decrease and TDS increase throughout 72 hours. Used P1 = 6 bar/P2 = 3 bar showed a better result compared to P1 = 6/P2 = 4 and P1 = 7/P2 = 4 in producing clean water. Provided clean water at 20 ppm has been done by RO multi-pass, which permeates the first stage used as a feed in the second stage. P1 = 6 bar and P2 = 3 bar give the saturation time of membrane 72-80 hour on the first stage and 72-131 hour on the second stage.
Antioxidant activity of endophytic fungi isolated from the stem bark of Swietenia mahagoni (L.) Jacq
Authors: Elfita Elfita , Muharni Muharni , Yohandini Heni , Fadhillah Fadhillah
Published: January 2021

Endophytic fungi are microbes that live to form colonies in plant tissue without harming their host plants. Each higher plant has the potential to contain several endophytic fungi that produce secondary metabolites as a result of coevolution or genetic recombination of the host plant. Endophytic fungi derived from medicinal plants are candidates for producing bioactive compounds. Swietenia mahagoni known as mahoni, is a medicinal plant that has been used to treat various diseases such as to prevent degenerative diseases. Almost all degenerative diseases are caused by free radicals. The endophytic fungus of S. mahagoni is a potential source for the discovery of antioxidant compounds. In the present study, we report an antioxidant compound from endophytic fungal isolated from the stem bark of S. mahagoni. Antioxidant activity was tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The compound was identified by the spectroscopic method as phenolic compound. The endophytic fungi were identified by molecularly based on genetic analysis as Cladosporium tenuissimum
The use of 1H-NMR spectroscopy and chemometrics of pattern recognition for authentication of Curcuma xanthorrhiza adulterated with Zingiber montanum
Authors: Windarsih A , Nisa K , Indrianingsih A W , Darsih C , Handayani S , Wulanjati M P , Rosyida V T , Wijayanti T , Rohman A
Published: January 2021

Curcuma xanthorrhiza is widely used in food and traditional medicine products. Due to its high demand, it is potential to be substituted or mixed with other species having similar appearance, therefore, rapid and reliable analytical method is highly required. The objective of this study was to develop 1H-NMR spectroscopy and chemometrics of pattern recognition as a metabolite fingerprinting technique for authentication of C. xanthorrhiza from Zingiber montanum. The powdered rhizomes were extracted using combination of methanol-D4 and phosphate buffer pH 6.0 in deuterium oxide (1:1 v/v) containing trimethylsilyl propionic acid (TSP) for chemical shift calibration. The variables extracted from 1H-NMR spectra were used for creating chemometrics models. Chemometrics of partial least square-discriminant analysis (PLS-DA) using 7 principal components (PCs) successfully classified between authentic and adulterated samples of C. xanthorrhiza with high value of R2X (0.988), R2Y (0.998), and Q2 (0.993). Moreover, chemometrics of orthogonal projection to latent structures-discriminant analysis (OPLS-DA) using 2 PCs and 4 orthogonal components perfectly discriminated authentic and adulterated samples of C. xanthorrhiza. The model showed high R2X (0.965), R2Y (0.976) as well as Q2 (0.946) values. Validation using permutation test confirmed the validity both PLS-DA and OPLS-DA models. It suggested that combination of 1H-NMR and chemometrics method is promising for authentication of medicinal plants.
Microplastic Pollutant Degradation in Water Using Modified TiO2 Photocatalyst Under UV-Irradiation
Authors: Fadli Muhamad Haris , Ibadurrohman Muhammad , Slamet Slamet
Published: January 2021

Modified TiO2 photocatalyst has been widely studied on its ability to degrade pollutants in water. Nowadays, one of the water pollutants that significantly polluted water is microplastic. Photocatalyst TiO2 can create an oxidizing agent to degrade microplastic pollutants but have a very high recombination rate of electrons and holes. By modifying TiO2 with silver dopant using Photo-assisted Deposition (PAD) and Reduced Graphene oxide (RGO) using the ultrasonic radiation method, can highly increase the ability of TiO2 catalyst. The modified catalyst was characterized by SEM-EDX and UV-Vis DRS to analyze the properties change of the composite. The performance of composites in degrading microplastic (polyethylene) was tested under UV radiation for 4 hours. The Ag/TiO2/RGO catalyst has a significantly high degradation percentage with 76% compared to pure TiO2 and Ag/TiO2 with degradation percentage of 56% and 68% respectively.
Macro and micromineral in commercial infant formula milk in Indonesia by neutron activation analysis
Authors: Kusmartini Indah , Kurniawati Syukria , Adventini Natalia , Damastuti Endah , Prakoso Djoko , Niken Woro Yatu , Sari Dyah Kumala , Lestiani Diah Dwiana , Muhayatun
Published: January 2021

The content of protein and minerals in infants formula milk is composed based on the composition of breast milk that provides adequate nutritional requirements for food intake in infants. Minerals as in macro and microminerals are essential for biological processes since they involve bone mineralization, enzymatic reactions, secretion of natural hormones, cells and lipid protection. The composition of macro and micromineral is one indicator in influential the quality of formula milk. Therefore, in this activity, the determination of macro and micromineral elements in infant formula milk was carried out by Neutron Activation Analysis (NAA) method and evaluated formula milk by considering the concentration of daily nutritional requirements. Formula milk samples were obtained in Indonesian market. The samples were irradiated on a lazy susan system at TRIGA 2000 Bandung Reactor with a neutron flux of ˜ 1013 n.cm−2.s−1 for three days. The validation method was also carried out using Typical Diet standard reference material. The validation results have a good agreement with the certificate value with bias (%) ranging from 0.6 to 6.9. Determination of macro and micromineral nutrients using NAA method resulted K, Na, Fe, Se, and Zn with an average value were 0.66%; 0.25%; 82.7 µg/g; 0.14 µg/g; and 34.7 µg/g respectively. These values were still within the concentration ranges as stated in nutritional labelled by manufacturers. The daily intake of macro and micromineral K, Na, Fe, Se, and Zn were 5150, 5110, 65, 0.11, and 27 mg/day, respectively. By consuming tolerable amounts of infant formula milk, this commodity is a source of nutrition that required by the infant’s nutritional adequacy rate.
Drug Development from Peptide-derived Marine Natural Products
Authors: Sukmarini L
Published: January 2021

Marine natural products (MNPs) provide an ample source of pharmacologically bioactive compounds with great chemical diversity and complexity. Peptide-derived MNPs are a class of compounds with diverse and interesting biological properties, such as antiinfective, anticancer, cytotoxic, and antiallodynic. Their biosynthetic production machinery from the ribosomal origin or non-ribosomal origin and the hybrid with other compounds confer these compounds remarkable diversity in terms of structural complexity as well as biological activity. The interest in these peptide compounds is their potential to produce valuable therapeutics and pharmaceuticals. Some of these peptides or their derivatives have reached the pharmaceutical market, while some are currently under clinical trials for developing new drugs. This review focuses on marine peptide-based compounds in advanced drug development for clinical use or pharmaceutical applications. The drug development process and clinical status of ribosomal peptides, non-ribosomal peptides and their hybrids, or the derivatives, are hereby described.
Preliminary assessment of heavy metals in street vended foods in the surrounding of elementary school area in Bandung city, Indonesia.
Authors: Damastuti Endah , Adventini Natalia , Oginawati Katerina , Niken Syahfitri Woro Yatu , Kurniawati Syukria , Santoso Muhayatun
Published: January 2021

Street vended foods are ready to eat foods sold by the vendors in the street and easily found in the school surrounding area. The availability and affordability of street vended foods made it widely consumed by large of population include children, especially when it is packaged attractively. Unfortunately, the safety of street vended foods especially related to the heavy metal contaminant is still unknown. Therefore, assessing the heavy metal level of street vended foods that widely consumed by children need to carried out. A number of 24 street vended food samples were collected in four elementary school surrounding area in Bandung city. The determination of heavy metal content in this food samples was conducted by neutron activation analysis and atomic absorption spectrometry as well. The quality of analytical results was evaluated using Standard Reference Material (SRM) NIST 1548a Typical Diet and 1567a Wheat Flour. Compare to the maximum permissible limit established by Indonesian Food and Drug Control Agency (BPOM), it was found that Cu, Hg and Zn concentration of street vended foods were below their maximum permissible limit. However, health risk assessment through Hazard Index (HI) formulation indicated that children in Bandung city may possess non-carcinogenic health risk due to heavy metals from the consumption of several street vended foods since the HI value are in the range of 0.06 – 2.32 with more than 10% of the foods observed were have HI > 1. These may be harmful situation to the children health. Further supervision of the preparation and handling of the vended foods are needed and guidance about the importance of hygiene and quality of vended foods to the vendors need to be improved.
Preparation and characterization of superparamagnetic α-Fe2O3/Fe3O4@SiO2 nanocomposites via a citric-TEOS-ethanol solution combustion process
Authors: Liu Min , Yu Lulu , Zhang Yanling , Zhang Shaoshuai , Yang Yanxin , Liu Ruijiang
Published: January 2021

Superparamagnetic α-Fe2O3/Fe3O4@SiO2 nanocomposites were prepared by the citric-TEOS-ethanol solution combustion method. Four key influencing factors, i.e. the calcination temperature, the volume of anhydrous ethanol, the volume of tetraethyl orthosilicate (TEOS), and the molar ratio of iron nitrate and citric acid (IN:CA) were investigated. The calcination temperature and the volume of anhydrous ethanol mainly affected the phase composition of α-Fe2O3/Fe3O4@SiO2 nanocomposite, and the volume of TEOS and the ratio of IN:CA had a great influence on the crystallinity of α-Fe2O3/Fe3O4@SiO2 nanocomposites. The tendency for the properties of superparamagnetic α-Fe2O3/Fe3O4@SiO2 nanocomposites changing with the conditions was explored and the mechanism was analyzed.
Experimental and theoretical analysis on pump spectral propriety of single frequency Erbium-Ytterbium co-doped fiber amplifier
Authors: Bai Xiaolei , Wang Meng , Yang Yuxing , Liu Zhen , Jia Weiguo
Published: January 2021

The pump spectral propriety of three types of commercial 915 and 976 nm LDs on single frequency Erbium-Ytterbium co-doped fiber amplifier (EYDFA) is theoretical and experimental analyzed. The slope efficiency, ASE intensity and linewidth broadening of the wavelength stabilized or un-stabilized LDs pumped amplifier are compared in detail. The results demonstrate that 976 nm LD pumping exhibits superior to 915 nm LD in efficiency and SNR. Comparing with wavelength stabilized 976 nm LD, the wavelength un-stabilized 976 nm LD with center wavelength deviating from Yb absorption peak and over 4 nm linewidth has better performance in Yb-ASE suppression but slightly lower in efficiency and linewidth broadening. The difference between the two 976 nm LDs could be taped off by increasing the seed power or output power. This work indicate that wavelength un-stabilized 976 nm LD is more suitable for pumping high power single-frequency EYDFA to avoid the bottlenecking effect, and provide reference for the optimal pump selection.
ITO conducting coatings properties improvement via nanotechnology approach
Authors: Kamanina Natalia , Toikka Andrey , Gladysheva Irina
Published: January 2021

In this paper the investigation devoted to study and development of the optimized ITO conducting layers are presented and discussed under the conditions of the materials surfaces laser structuration in order to apply the modified conducting materials in the optoelectronics, virus protection, solar energy, microscopy, biomedicine, etc. area. Based on our knowledge and expertise it is established the dramatic change of the main characteristics of the ITO matrix, which surface is modified by the carbon nanotubes (CNTs), and additionally treated by surface electromagnetic waves (SEW) as well. The transmittance and reflection spectral change, increase of the micro hardness and laser strength as well as the increase of the wetting angle and refraction change are discussed due to the covalent bonding between the carbon nanotubes and the near-surface atoms of the matrix materials. As the unique point of the study the effective decrease of the resistivity is established and presented. Quantum chemical simulations are supported the data presented.
Doublecortin facilitates the elongation of the somatic Golgi apparatus into proximal dendrites
Authors: Li Peijun , Li Luyao , Yu Binyuan , Wang Xinye , Wang Qi , Lin Jingjing , Zheng Yihui , Zhu Jinjin , He Minzhi , Xia Zhaonan , Tu Mengjing , Liu Judy S. , Lin Zhenlang , Fu Xiaoqin
Published: January 2021

We identified CLASP2, dynein, and JIP3 as possible new doublecortin (DCX) targets that are involved in DCX regulation of the dendritic distribution of somatic Golgi apparatus in mouse neurons.
Development of novel bioassays to detect soluble and aggregated Huntingtin proteins on three technology platforms
Authors: Landles Christian , Milton Rebecca E , Jean Alexandre , McLarnon Stuart , McAteer Sean J , Taxy Bridget A , Osborne Georgina F , Zhang Chuangchuang , Duan Wenzhen , Howland David , Bates Gillian P
Published: January 2021

Huntington’s disease is caused by a CAG / polyglutamine repeat expansion. Mutated CAG repeats undergo somatic instability, resulting in tracts of several hundred CAGs in the brain; and genetic modifiers of Huntington’s disease have indicated that somatic instability is a major driver of age of onset and disease progression. As the CAG repeat expands, the likelihood that exon 1 does not splice to exon 2 increases, resulting in two transcripts that encode full-length huntingtin protein, as well as the highly pathogenic and aggregation-prone exon 1 huntingtin protein. Strategies that target the huntingtin gene or transcripts are a major focus of therapeutic development. It is essential that the levels of all isoforms of huntingtin protein can be tracked, to better understand the molecular pathogenesis, and to assess the impact of huntingtin protein-lowering approaches in preclinical studies and clinical trials. Huntingtin protein bioassays for soluble and aggregated forms of huntingtin protein are in widespread use on the homogeneous time-resolved fluorescence and Meso Scale Discovery platforms, but these do not distinguish between exon 1 huntingtin protein and full-length huntingtin protein. In addition, they are frequently used to quantify huntingtin protein levels in the context of highly expanded polyglutamine tracts, for which appropriate protein standards do not currently exist. Here, we set out to develop novel huntingtin protein bioassays to ensure that all soluble huntingtin protein isoforms could be distinguished. We utilized the zQ175 Huntington’s disease mouse model that has ∼190 CAGs, a CAG repeat size for which protein standards are not available. Initially, 30 combinations of six antibodies were tested on three technology platforms: homogeneous time-resolved fluorescence, amplified luminescent proximity homogeneous assay and Meso Scale Discovery, and a triage strategy was employed to select the best assays. We found that, without a polyglutamine-length-matched standard, the vast majority of soluble mutant huntingtin protein assays cannot be used for quantitative purposes, as the highly expanded polyglutamine tract decreased assay performance. The combination of our novel assays, with those already in existence, provides a tool-kit to track: total soluble mutant huntingtin protein, soluble exon 1 huntingtin protein, soluble mutant huntingtin protein (excluding the exon 1 huntingtin protein) and total soluble full-length huntingtin protein (mutant and wild type). Several novel aggregation assays were also developed that track with disease progression. These selected assays can be used to compare the levels of huntingtin protein isoforms in a wide variety of mouse models of Huntington’s disease and to determine how these change in response to genetic or therapeutic manipulations.
Video Anomaly Detection Using the Optimization-Enabled Deep Convolutional Neural Network
Authors: Philip Felix M , V Jayakrishnan , F Ajesh , P Haseena
Published: January 2021

In video surveillance, automatic detection of the anomalies is the active research area in computer technology. Even though various video anomaly detection methods are introduced, detecting anomalous events, such as illegal actions and crimes, is a major challenging issue in video surveillance. Thus, an effective automatic video anomaly detection strategy based on the deep convolutional neural network (deep CNN) is developed in this research. Initially, the input video surveillance is passed into the spatiotemporal feature descriptor, named Histograms of Optical Flow Orientation and Magnitude. The features obtained from the descriptor provide the optical flow details with the aspect of normal patterns from the scene. These patterns are further subjected to the deep CNN, which is trained using the proposed dragonfly-rider optimization algorithm (DragROA) to assure the classification either as an anomalous activity or normal. The proposed DragROA is the combination of the standard dragonfly optimization algorithm and the standard rider optimization algorithm. The implementation of the proposed DragROA-based deep CNN is carried out using two datasets, namely anomaly detection dataset and UMN dataset; the performance is analyzed using the metrics, namely accuracy, sensitivity and specificity. From the analysis, it is depicted that the proposed method obtains the maximum accuracy, sensitivity and specificity of 0.9922, 0.9809 and 1, respectively, for the UCSD dataset.
Lessons From a 10-yr Invasive Species Webinar Program: Emerald Ash Borer University
Authors: Barnes Elizabeth E , Usborne Robin , Stone Amy , Sadof Clifford S
Published: January 2021

Information about invasive species needs to be spread rapidly across a wide geographic area following an invasion. However, in-person events can be time-consuming and costly for the participants, organizers, and presenters. Online programming like webinars can bridge this gap, but there is limited published data on how best to run these programs. We report on a 10-yr webinar program, Emerald Ash Borer University, and offer suggestions for improving their effectiveness as a communication tool. Webinar participants viewed the webinars positively and undertook recommended management actions. In addition, most of our survey respondents extended the reach of this program by widely sharing the information from the webinars. Posting the webinars on popular streaming platforms greatly extended their reach long after the live viewing event. Despite their longevity, viewers of recorded videos watched them differently than those viewing live events. We suggest modifying the format of future webinar presentations to accommodate these differences to improve information transfer.
EVIDENCE FOR POLYGENIC EPISTATIC INTERACTIONS IN MAN?
Authors: Heath A C , Martin N G , Eaves L J , Loesch D
Published: January 2021

Studies of multifactorial inheritance in man have ignored nonadditive gene action or attributed it entirely to dominance. Reanalyses of dermatoglyphic data on monozygotic and dizygotic twins, siblings and parents and offspring suggest that a substantial proportion of variation in total finger pattern intensity is due to epistatic interactions between additive genetic deviations, not dominance. Bootstrapping and power simulations support this interpretation of the data. We believe this is the strongest evidence so far for polygenic epistasis in man.
MUTATIONS AFFECTING TY-MEDIATED EXPRESSION OF THE HIS4 GENE OF SACCHAROMYCES CEREVISIAE
Authors: Winston Fred , Chaleff Deborah T , Valent Barbara , Fink Gerald R
Published: January 2021

We have identified mutations in seven unlinked genes (SPT genes) that affect the phenotypes of Ty and δ insertion mutations in the 5′ noncoding region of the HIS4 gene of S. cerevisiae. Spt mutants were selected for suppression of his4-912δ, a solo δ derivative of Ty912. Other Ty and δ insertions at HIS4 are suppressed by mutations in some but not all of the SPT genes. Only spt4 suppresses a non-Ty insertion at HIS4. In addition to their effects on Ty and δ insertions, mutations in several SPT genes show defects in general cellular functions—mating. DNA repair and growth.
IDENTIFICATION OF THE BACTERIOPHAGE T4 unf (=alc) GENE PRODUCT, A PROTEIN INVOLVED IN THE SHUTOFF OF HOST TRANSCRIPTION
Authors: Herman Richard E , Haas Nancy , Snustad D Peter
Published: January 2021

The introduction of plasmid pR386 into E. coli cells renders them restrictive to the growth of phage T4 unf (=alc) mutants. This system has been used to isolate Unf+ revertants, which, along with the mutant parental strains, have been used to identify the unf gene product by two-dimensional gel electrophoresis. Synthesis of the unf gene product, a polypeptide of just over 18,000 daltons in size, begins within 1 min after infection and terminates at about 12 min after infection at 30°. Gene dosage experiments suggest that the unf protein functions catalytically.
GENES AFFECTING THE REGULATION OF SUC2 GENE EXPRESSION BY GLUCOSE REPRESSION IN SACCHAROMYCES CEREVISIAE
Authors: Neigeborn Lenore , Carlson Marian
Published: January 2021

Mutants of Saccharomyces cerevisiae with defects in sucrose or raffinose fermentation were isolated. In addition to mutations in the SUC2 structural gene for invertase, we recovered 18 recessive mutations that affected the regulation of invertase synthesis by glucose repression. These mutations included five new snf1 (sucrose nonfermenting) alleles and also defined five new complementation groups, designated snf2, snf3, snf4, snf5 and snf6. The snf2, snf4 and snf5 mutants produced little or no secreted invertase under derepressing conditions and were pleiotropically defective in galactose and glycerol utilization, which are both regulated by glucose repression. The snf6 mutant produced low levels of secreted invertase under derepressing conditions, and no pleiotropy was detected. The snf3 mutants derepressed secreted invertase to 10-35% the wild-type level but grew less well on sucrose than expected from their invertase activity; in addition, snf3 mutants synthesized some invertase under glucose-repressing conditions.—We examined the interactions between the different snf mutations and ssn6, a mutation causing constitutive (glucose-insensitive) high-level invertase synthesis that was previously isolated as a suppressor of snf1 . The ssn6 mutation completely suppressed the defects in derepression of invertase conferred by snf1, snf3, snf4 and snf6, and each double mutant showed the constitutivity for invertase typical of ssn6 single mutants. In contrast, snf2 ssn6 and snf5 ssn6 strains produced only moderate levels of invertase under derepressing conditions and very low levels under repressing conditions. These findings suggest roles for the SNF1 through SNF6 and SSN6 genes in the regulation of SUC2 gene expression by glucose repression.
TRAITS THAT INFLUENCE LONGEVITY IN MICE
Authors: Yunis Edmond J , Watson Ada L M , Gelman Rebecca S , Sylvia Sherrill J , Bronson Roderick , Dore Martin E
Published: January 2021

Analysis of genetic interactions in the segregating backcross [(C57BL/6 x DBA/2)F1 x DBA/2] mice revealed influences of genetic and environmental factors on life span. Using determinants of coat color (brown locus of chromosome 4 and dilute locus of chromosome 9), serologically determined H-2 antigens (chromosome 17) and sex as genetic markers, we studied the effects of these genes on longevity. The results suggested that genes in the brown locus (b) segment of chromosome 4, genes in a segment of the sex chromosomes and, to a more limited extent, genes in the segment of chromosome 17 which contains the H-2 haplotype all influenced longevity. The coat color (b locus) segment of chromosome 4 was associated with life span predominantly in females, whereas the chromosome 17 (H-2 haplotype) segment was associated with longer life primarily in males. The dilute locus d segment on chromosome 9 did not affect life span. Longevity appears to be influenced by interactions between genes in the chromosomal segment carrying H-2, those in the b segment, gender and the month of birth. Greater heterozygosity at the loci studied was associated with longer life span. Histopathological findings on mice that died at or after 28 months of age were comparable for all genetic combinations except that there was an increased frequency of lymphoma in females and an increased frequency of amyloidosis in males. Our analysis emphasizes the need for comprehensive studies of aging and longevity that would simultaneously determine the effects of several genetic regions and their interactions with the environment with respect to possible causes of death.
EVOLUTION OF RESISTANCE IN THE PRESENCE OF TWO INSECTICIDES
Authors: Mani G S
Published: January 2021

A two-locus model is used to analyze the effectiveness of a mixture of insecticides in delaying resistance, compared to the use of the insecticides singly. The effects of factors such as recombination, effective dominance, initial value of allele frequencies and initial value of linkage disequilibrium are considered. It is shown that the use of mixtures is always more effective in delaying the onset of resistance, often by many orders of magnitude. It is shown that there exists a threshold value of recombination fraction, above which the evolution of resistance is extremely slow. Resistance evolves very rapidly for values of recombination fraction below the threshold. Finally, the relevance of these results on resistance management is discussed.
MUTATIONS THAT IMPROVE THE ANT PROMOTER OF SALMONELLA PHAGE P22
Authors: Graña Dolores , Youderian Philip , Susskind Miriam M
Published: January 2021

Mutations that increase the activity of the promoter for the antirepressor gene of phage P22 were isolated by pseudoreversion of four severe promoter-down mutations. The sequence changes in these pseudorevertants include single base pair substitutions, single base pair deletions, tandem double base pair deletions and multisite mutations. The single base pair substitutions change nonconsensus base pairs to consensus base pairs at positions -14 and -8. The other mutations provide support for the idea that the length of the spacer region between the conserved -35 and -10 hexamers is an important determinant of promoter strength. Deletions of one or two base pairs in the spacer region apparently activate an alternate -10 hexamer by shifting it from a spacing of 19 base pairs to a spacing of 18 or 17 base pairs, respectively.
THE ECOLOGICAL GENETICS OF INTRODUCED POPULATIONS OF THE GIANT TOAD BUFO MARINUS. II. EFFECTIVE POPULATION SIZE
Authors: Easteal Simon
Published: January 2021

The allele frequencies are described at ten polymorphic enzyme loci (of a total of 22 loci sampled) in 15 populations of the neotropical giant toad, Bufo marinus, introduced to Hawaii and Australia in the 1930s. The history of establishment of the ten populations is described and used as a framework for the analysis of allele frequency variances. The variances are used to determine the effective sizes of the populations. The estimates obtained (390 and 346) are reasonably precise, homogeneous between localities and much smaller than estimates of neighborhood size obtained previously using ecological methods. This discrepancy is discussed, and it is concluded that the estimates obtained here using genetic methods are the more reliable.
NEUROSPORA TREHALASE AND ITS STRUCTURAL GENE
Authors: White Christopher , Lee Deborah B , Free Stephen J
Published: January 2021

We have isolated Neurospora trehalaseless mutants and mapped the trehalase structural gene to linkage group I. The structural gene mutations not only affect thermostability and other characteristics of the enzyme but also affect the production of an inhibitor of the wild-type trehalase. The inhibitor appears to be the mutant trehalase. We suggest that the mutant subunits act as inhibitors by entering into the multimeric forms of the enzyme and altering the ability of the normal wild-type subunits to catalyze the cleavage of trehalose.—Wild type trehalase has been purified to near homogeneity, and its characteristics have been studied. It was purified as a tetramer, with each subunit having a molecular weight of 88,000.—We have studied the regulation of trehalase and found the production of trehalase to be glucose repressible. Cells begin to produce trehalase 60 min after being transferred to glucose-free medium.
BOTH NUCLEOLAR ORGANIZERS ARE REPLICATED IN DIPTERAN POLYPLOID TISSUES: A STUDY AT THE LEVEL OF INDIVIDUAL NUCLEI
Authors: Belikoff Esther J , Beckingham Kathy
Published: January 2021

Working with the Dipteran Calliphora erythrocephala, we have tested the hypothesis that only one nucleolar organizer region (NO) is replicated during polyploidization. NO replication was examined in two very different highly polyploid nuclear types: salivary gland nuclei and nurse cell nuclei. Two strains of the organism containing NO regions with highly diagnostic nontranscribed spacer (NTS) polymorphisms were prepared and reciprocal single pair-matings between members of the strains were performed. The representation of the two distinguishable NOs in diploid and polyploid DNAs of individual F1 progeny from each cross was then examined. DNA from a total polyploid nuclear DNA preparation and from individual polyploid nuclei of both tissue types was analyzed. Our results show conclusively that both genomic NOs are replicated in individual polyploid nuclei of both types. Further, evidence for variation in the relative replication of cistrons from the two NOs by individual nuclei was obtained. The cistron types present in the NOs of both strains showed differential replication upon polyploidization. In general, the patterns of differential cistron replication seen in salivary gland and nurse cell nuclei were similar.
HYBRID DYSGENESIS IN DROSOPHILA MELANOGASTER: NATURE AND INHERITANCE OF P ELEMENT REGULATION
Authors: Kidwell Margaret G
Published: January 2021

The genetic determination of the control of resistance or susceptibility to germ line changes mediated by P elements was studied in two strains and in derivatives of crosses between them. One strain, characterized as true M, completely lacked P elements. The second strain, pseudo-M (M'), carried a number of P elements, but these did not have the potential to induce the gonadal sterility that is associated with P-M hybrid dysgenesis. Individuals from the true M strain were invariably unable to suppress P factor activity (i.e., all daughters of outcrosses of M females and P males were sterile). In contrast, individuals from the M' strain showed variable degrees of suppression that were manifested in a wide range of gonadal sterility frequencies in standard tests. This continuous distribution pattern was reproducible for more than 25 generations.—The results of the genetic analysis indicate that a strain with a variable degree of suppression of gonadal dysgenesis is not necessarily in a transient state between the extreme conditions of P and M cytotype. A large variance in the ability to suppress gonadal dysgenesis with a mean value intermediate between the extremes of P and M cytotype may be a relatively stable strain characteristic. No reciprocal cross effect was observed in the suppression of sterility of F1 females from M × M' matings. Thus, the existence of M' strains indicates a Mendelian component in P element regulation and suggests that cytotype, which has an extrachromosomal aspect, may be only one of perhaps several mechanisms involved in regulation. Analysis of the effects of individual chromosomes from the M' strain showed that each chromosome contributed to the reduction of gonadal dysgenesis in the progeny of test matings. The results are consistent with a one-component titration model for P element regulation.
GENETIC ANALYSIS OF MATING LOCUS LINKED MUTATIONS IN CHLAMYDOMONAS REINHARDII
Authors: Galloway R E , Goodenough U W
Published: January 2021

The mating-type (mt) locus of Chlamydomonas reinhardii has been analyzed using four mutant strains (imp-1, imp-10, imp-11 and imp-12). All have been shown, or are shown here, to carry mutations linked to either the plus (mt  +) or the minus (mt  -) locus, and their behavior in complementation tests has allowed us to define several distinct functions for each locus. Specifically, we propose that the mt  + locus contains the following genes or regulatory elements: a locus designated sfu, which is necessary for sexual fusion between gametes; a locus designated upp (uniparental plus), which controls aspects of chloroplast gene inheritance and perhaps also zygote maturation; and a locus designated sad, which functions in sexual adhesion. The mt  - locus also contains a sad locus as well as a gene or regulatory element designated mid, which is necessary for the minus dominance in mt  +/mt  - diploids.
LIMITS OF ADAPTATION: THE EVOLUTION OF SELECTIVE NEUTRALITY
Authors: Hartl Daniel L , Dykhuizen Daniel E , Dean Antony M
Published: January 2021

Many enzymes in intermediary metabolism manifest saturation kinetics in which flux is a concave function of enzyme activity and often of the Michaelis-Menten form. The result is that, when natural selection favors increased enzyme activity so as to maximize flux, a point of diminishing returns will be attained in which any increase in flux results in a disproportionately small increase in fitness. Enzyme activity ultimately will reach a level at which the favorable effect of an increase in activity is of the order 1/(4Ne) or smaller, where Ne is the effective population number. At this point, many mutations that result in small changes in activity will result in negligible changes in fitness and will be selectively nearly neutral. We propose that this process is a mechanism whereby conditions for the occurrence of nearly neutral mutations and gene substitutions can be brought about by the long-continued action of natural selection. Evidence for the hypothesis derives from metabolic theory, direct studies of flux, studies of null and other types of alleles in Drosophila melanogaster and chemostat studies in Escherichia coli. Limitations and complications of the theory include changes in environment or genetic background, enzymes with sharply defined optima of activity, overdominance, pleiotropy, multifunctional enzymes and branched metabolic pathways. We conclude that the theory is a useful synthesis that unites many seemingly unrelated observations. The principal theoretical conclusion is that the conditions for the occurrence of neutral evolution can be brought about as an indirect result of the action of natural selection.
REDUCED REPRODUCTIVE SUCCESS FOR A CONDITIONING MUTANT IN EXPERIMENTAL POPULATIONS OF DROSOPHILA MELANOGASTER
Authors: Gailey Donald A , Hall Jeffrey C , Siegel Richard W
Published: January 2021

Male Drosophila melanogaster that have courted newly-emerged males can modify their subsequent courtship behavior to avoid further courtship with immature males for up to 6 hr (previously reported). Here, it was hypothesized that such an experience-dependent modification would afford a mating advantage to normal males over males that carried a mutation that affects learning and memory. Coisogenic lines were constructed which varied at the dunce gene (dnc  + and dnc  M14 alleles) in order to test this hypothesis. Whether previously experienced with immature males or not, dnc  + and dnc  M14 males were indistinguishable in their response and mating efficiency when individually paired with virgin females. However, courtship performance of dnc  + and dnc  M14 males was different if they were first experienced with immature males and were then individually tested in an artificial population of nine immature males and one virgin female. In this situation, dnc  + males spent much less time in courtship with immature males and achieved copulation in one-third the time required for dnc  M14 males. As a control, the behavior and mating efficiency of courtship-naive dnc  + and dnc  M14 males in the artificial population was indistinguishable. In competition for a single virgin female, experienced dnc  M14 males showed a slight mating advantage over experienced dnc  + males. But when competition by experienced males for a single virgin female took place in the presence of nine immature males, dnc  + males were the successful maters in three-fourths of the trials.
HOMOZYGOUS AND HEMIZYGOUS VIABILITY VARIATION ON THE X CHROMOSOME OF DROSOPHILA MELANOGASTER
Authors: Eanes Walter F , Hey Jody , Houle David
Published: January 2021

We report here a study of viability inbreeding depression associated with the X chromosome of Drosophila melanogaster. Fifty wild chromosomes from Mt. Sinai, New York, and 90 wild chromosomes from Death Valley, California, were extracted using the marked FM6 balancer chromosome and viabilities measured for homozygous and heterozygous females, and for hemizygous males, relative to FM6 males as a standard genotype. No statistically significant female genetic load was observed for either chromosome set, although a 95% confidence limit estimated the total load <0.046 for the samples pooled. About 10% of the Death Valley chromosomes appear to be "supervital" as homozygotes. There is little evidence for a pervasive sex-limited detrimental load on the X chromosome; the evidence indicates nearly identical viability effects in males and homozygous females excluding the supervital chromosomes. The average degree of dominance for viability polygenes is estimated between 0.23 to 0.36, which is consistent with autosomal variation and implies near additivity. We conclude that there is little genetic load associated with viability variation on the X chromosome and that the substantial reduction in total fitness observed for chromosome homozygosity in an earlier study may be due largely to sex-limited fertility in females.
TISSUE-SPECIFIC AND COMPLEX COMPLEMENTATION PATTERNS IN THE PUNCH LOCUS OF DROSOPHILA MELANOGASTER
Authors: Mackay William J , Reynolds Elaine R , O'Donnell Janis M
Published: January 2021

Mutations in the Punch locus result in loss of GTP cyclohydrolase activity, but all mutations do not affect the enzyme in the same way. There are at least three classes of Punch mutations. One class results in a dominant eye color, recessive lethal phenotype. A second class of mutations also causes a recessive lethal phenotype, but heterozygous mutants have normal eye color. They show loss of GTP cyclohydrolase function in all tissues where activity can be measured. Alleles comprising a third class are recessive eye color mutations that are homozygous viable. Individuals with this third type of mutation show loss of enzyme activity in the eye, but show normal or near-normal activity elsewhere. In order to examine the organization and function of this locus further, we have performed interallelic complementation tests on 25 Punch mutations, monitoring viability and enzyme activity in prepupae and adults. Most allele combinations are lethal. Those that complement do so in ways that are tissue-or stage-specific and unpredictable. Tests of mutants with tissue-specific phenotypes and of individuals mutant for complementing Punch lethal alleles lead us to conclude that Punch is a complex locus, both with respect to its organization and to its products.
MOLECULAR GENETIC CHARACTERIZATION OF A LOCUS THAT CONTAINS DUPLICATE Adh GENES IN DROSOPHILA MOJAVENSIS AND RELATED SPECIES
Authors: Mills Leslie E , Batterham Philip , Alegre John , Starmer William T , Sullivan David T
Published: January 2021

Drosophila mojavensis and other species of the mulleri subgroup contain a duplicate gene encoding the enzyme alcohol dehydrogenase (ADH). Studies on the genetic relationship of the two genes using electrophoretic variants show them to be closely linked. We have cloned a 13.5-kb fragment of D. mojavensis DNA into the lambda vector, Charon 30. This fragment contains both Adh genes separated by approximately 2 kb of DNA. The clone hybridized to a single position on chromosome 3 in D. mojavensis following in situ hybridization. It is likely that the genes are tandemly arranged in the genome. One of the two genes shows a complexity in its structure that suggests the close linkage of a pseudogene or part of a gene.—The structure of the Adh locus in five species of the mulleri subgroup have been compared by constructing restriction maps of genomic DNA. Two of these species D. arizonensis and D. mojavensis express Adh-1 in the ovaries; the others do not. In comparing these species it is evident that there has been one or two insertions into the region between the Adh genes. It is possible that one of these structural changes is related to the change in Adh tissue-specific expression that has occurred during the evolution of these species.
A MODEL FOR DNA SEQUENCE EVOLUTION WITHIN TRANSPOSABLE ELEMENT FAMILIES
Authors: Brookfield J F Y
Published: January 2021

A quantitative model is proposed for the expected degree of relationship between copies of a family of transposable elements in a finite population of hosts. Special cases of the model (in which the process of homogenization of element copies either is or is not limited by transposition rate) are presented and illustrated, using data on mobile sequences from different species. It is shown that transposition will be expected, in large populations, to result in only a rather distant relationship between transposable elements at different genomic sites. Possible inadequacies of the model are suggested and quantified.