bluuebunny/crossref_metadata_2025 huggingface dataset:
“Smart” nuclear cities and training
Authors: Putilov A V , Chervyakov V N , Kolykhalov P I
Published: April 2021

New innovative approaches to educational activities in “smart” nuclear cities are described. Examples of using the developed system of online control over student perception of materials of a particular discipline are given. Processing the results of monitoring the educational process allows you to draw preliminary conclusions about the abilities (giftedness) of students for certain types of activities, described, including in the course materials. The software and hardware complex can be used for other educational programs, which, depending on the subject area of study, allows you to form a kind of “digital portrait” of each student.
The productivity of a high-tech municipality: basic parameters and factors (based on the material of nuclear cities)
Authors: Polosin A V , Chikharev I A , Kostyuchenko M I , Ganat S A , Samoilova E S
Published: April 2021

Technological (digital) transformation, the evolution of the socio-demographic structure, profound changes in the economy of cities and the urban environment in the modern world determine the relevance of the search for new approaches to urban development. At the same time, high-tech municipalities, and in particular - Russian nuclear cities, possess significant features against the background of global trends. Using the methodology of systems analysis, expert surveys and comparative case studies, the article analyzes the productivity parameters of a high-tech municipality and approaches to urban development based on the material of Russian nuclear cities.
Retraction: An Empirical Study on the Driving Path of Optimizing the Resources Allocation of Foreign Trade Enterprises from the Perspective of Energy Supply-side Reform (IOP Conf. Ser.: Earth Environ. Sci.
94 012054)
Authors: You Yu-cong , Yi Lu-xia
Published: April 2021

IOP Publishing Limited ("IOPP") is retracting this paper following an investigation which revealed that sections of the manuscript are computer generated. IOP Publishing is investigating why this was not identified during the submission and peer review process by the conference. As a member of the Committee for Publication Ethics (COPE) this has been investigated in accordance with COPE guidelines and it was agreed the article should be retracted.

IOPP expresses its thanks to the independent advisors who have shared their thoughts regarding this paper during the course of the investigation.

Retraction published: 28 April 2021
Effects of Fe-Doped Electrolyte and Feed Flow Rate Evaluation in Home Made Solid Oxide Fuel Cell
Authors: Devianto Hary , Nurdin Isdiriyani , Widiatmoko Pramujo , Adi Prasetya Kafi , Pradipta Basil
Published: April 2021

Solid Oxide Fuel Cell (SOFC) is one type of fuel cell that has several advantages over other types of fuel cells. To achieve low cost SOFC, the materials used are nickel oxide (NiO) for the anode, Calcia Stabilized Zirconia (SCZ) for the electrolyte and Calcia Cobalt Oxide Zinc Oxide (CCZO) as cathode. Fe2O3 is a doping agent to form a denser electrolyte. The cell with and without Fe doping was tested using hydrogen and ambient air. Additionally, the effect of the amount of fuel flow rate is also investigated using Aspen Plus Modelling. Based on physical characterization, it is determined that 3%-mole Fe doping on the electrolyte increases the electrolyte density from 83% to 90%. Using electrochemical impedance spectroscopy, it can be concluded that SOFC with Fe doped electrolyte has a lower resistance than SOFC without Fe doping. On the other hand, using a correction factor, an equation of power correlated to fuel flow for the SOFC is generated to show increasing fuel flow enhanced SOFC performance.
Circular Economy on Organic Waste Management with MASARO Technology
Authors: Abidin A Z , Bramantyo H , Baroroh M K , Egiyawati C
Published: April 2021

MASARO technology presents a solution in solving the waste problem through an organic waste processing unit, known as IPPO (Organic Fertilizer and Feed Industry). The Masaro system characterises solid waste into five catagories including organic waste, low value plastic waste, incenerated waste, recycled waste, and hazardous waste. The organic waste will be separated into an organic fast-decaying waste to produce POCI (Special Liquid Organic Fertilizer) and KOCI (Special Liquid Organic Concentrate), and an organic slow-decaying waste to produce a compost. POCI is used as an organic fertilizer and its farming produces a higher production number, higher quality product, faster production rate while its production cost is lower. KOCI and compost is applied in the farm industry where the organic waste with low economic value is used as a raw material to produce new materials with higher economic value. These products can produce an environmentally friendly system and reflect the circular economy principle application. The organic waste is used as raw material for IPPO and its products form a circular economy through aplication in the farm industry that create lower cost production and sustainable development.
Isomerization of Raw Turpentine Using Various Combination of Strong and Weak Acid Catalyst for Eucalyptol Production
Authors: Elka Yudhatama Nicolaus , Almira Chairany Diva , Mufti Azis Muhammad , Indarto Antonius
Published: April 2021

There has been large interest to isomerize raw turpentine to produce a number of derivative products that has higher economic value. This process is often conducted using homogenous acid catalysts. Catalyst screening is often challenging to target a certain derivative product, such as cineole. The aim of present work is investigate various combination of strong and weak acid catalyst to obtain cineole. Strong acids used in this research were PTSA, hydrochloric acid, sulfuric acid. In addition, the weak acids were oxalic acid dihydrate, citric acid, and formic acid. Commercial turpentine was mixed with strong and weak acid with 4:1:6 ratio respectively, heated up to 85oC for 6 hours for each combination of strong and weak acid. The result from GC-MS analysis shows that combination of hydrochloric acid and formic acid gave the highest eucalyptol yield around 9.67% along with other valuable product such as camphene, limonene, and a-terpinolene.
Activity Test of CuO/γ-Al2O3 as Catalyst of Methanol Dehydration to Dimethyl Ether at Atmospheric Pressure
Authors: Susanto Edi , Ardy Aisyah , Susanto Herri
Published: April 2021

Dimethyl ether (DME) is already used as a propellant and intermediate chemicals. Now, Indonesia will use DME as alternative energy for Liquid Petroleum Gas (LPG), as a result of the continued increase in LPG imports. In this study, DME was synthesized by dehydration of methanol process. The y-Al2O3 and modified CuO/y-Al2O3 ITB use as catalysts for the process. The objective of this research was to compare of catalytic activity of two catalysts at methanol dehydration to DME. The catalyst activity test was carried out in a tubular fixed-bed reactor (ID 1 cm and length 21 cm). Methanol dehydration was carried out at 1 bar, GHSV 1,100-2,200/h, methanol 1.9-4 mL/h, N2 10-30 mL/min (27.5°C and 0.93 bar). The downstream gas of the reactor was analyzed using gas chromatography and the condensate was analyzed using a refractometer. The y-Al2O3-ITB catalyst gives the highest performance with 89.6% of methanol conversion, 6.6% of DME yield, and 16.6% of DME selectivity. Whereas CuO/y-Al2O3 catalyst has a lower performance by 85.5% of methanol conversion, 1.4% of DME yield, and 3.7% of DME selectivity.
Theoretical proposal for the experimental realisation of a monochromatic electromagnetic knot
Authors: Cameron R P , Löffler W , Stephan K D
Published: April 2021

We propose an antenna designed to generate monochromatic electromagnetic knots and other ‘unusual electromagnetic disturbances’ in the microwave domain. Our antenna is a spherical array of radiating dipolar elements configured to approximate the desired electromagnetic field near its centre. We show numerically that a specific embodiment of the antenna with a radius of 61.2 cm and only 20 element pairs driven at a frequency of 2.45 GHz can yield linked and torus-knotted electric and magnetic field lines approximating those of an ‘electromagnetic tangle’: a monochromatic electromagnetic knot closely related to the well-known Rañada–Hopf type electromagnetic knots but simpler in its construction. The antenna could be used to locally excite plasmas.
Antimicrobial and antioxidant properties of biosynthesized of NiO nanoparticles using Raphanus sativus (R. sativus) extract
Authors: Haq Sirajul , Dildar Sadaf , Ali Manel Ben , Mezni Amine , Hedfi Amor , Shahzad Muhammad Imran , Shahzad Nadia , Shah Amreen
Published: April 2021

The aim of this study was to explore the antibacterial and antioxidant efficacy of nickel oxide nanoparticles (NiO NPs). The Raphanus sativus (R. sativus) extract mediated NiO NPs were calcined at 100, 300, 600 and 900 ℃ in a muffle furnace for 3 h. The increased intensity of diffraction bands in the X-ray diffraction (XRD) spectrum suggest that the degree of crystallinity increases with increasing calcination temperature. The desired elements was depicted in the energy dispersive X-rays (EDX) spectrum confirm the purity of the NiO Sample. The variation in surface morphology and increase in the particles size from 12.78 to 51.42nm was determined from the transmission electron microscope (TEM) micrographs. The shift toward higher wavelength was observed in the diffuse reflectance spectroscopy (DRS) spectra with increasing calcination temperature, results into a clear decrease in band gap from 3.12 to 2.86 eV. The presence of hydroxyl group along with other organic moieties were confirm through Fourier transform infrared (FTIR) spectroscopy analysis. The biological potential of the calcined NiO NPs was examined during the antibacterial and antioxidant experiments. The antibacterial effect of NiO NPs was studied using the agar well diffusion process, and the ABTS free radical scavenging potential of NiO NPs was also assessed. The activity of NiO NPs calcined at 100 °C is greater than that of those calcined at higher temperatures.
Efficient removal of reactive blue-19 dye by co-electrospun nanofibers
Authors: Hakro Raheel Ahmed , Mehdi Mujahid , Qureshi Raja Fahad , Mahar Rasool Bux , Khatri Muzamil , Ahmed Farooq , Khatri Zeeshan , Kim Ick Soo
Published: April 2021

The present work demonstrates the new nanofiber mats prepared through co-electrospinning of two different polymers i.e. corn protein namely Zein and Nylon-6. The composite nanofiber membrane was used as an effective adsorbent material for the removal of toxic reactive dye i.e. Reactive Blue 19 (RB19) from water solution. These co-electrospun nanofibers had good mechanical strength compared to zein nanofibers alone. Experimental results suggested that zein/nylon nanofibers have greater potential for total removal of RB19 at room temperature within 10 min of contact time from aqueous solution. The maximum capacity was found to be 61.2 mg.g−1 of nanofibers. The mechanism of RB19 removal on proposed nanofibers is mainly through hydrogen bond and electrostatic means.
Quantum computer-aided design of quantum optics hardware
Authors: Kottmann Jakob S , Krenn Mario , Kyaw Thi Ha , Alperin-Lea Sumner , Aspuru-Guzik Alán
Published: April 2021

The parameters of a quantum system grow exponentially with the number of involved quantum particles. Hence, the associated memory requirement to store or manipulate the underlying wavefunction goes well beyond the limit of the best classical computers for quantum systems composed of a few dozen particles, leading to serious challenges in their numerical simulation. This implies that the verification and design of new quantum devices and experiments are fundamentally limited to small system size. It is not clear how the full potential of large quantum systems can be exploited. Here, we present the concept of quantum computer designed quantum hardware and apply it to the field of quantum optics. Specifically, we map complex experimental hardware for high-dimensional, many-body entangled photons into a gate-based quantum circuit. We show explicitly how digital quantum simulation of Boson sampling experiments can be realized. We then illustrate how to design quantum-optical setups for complex entangled photonic systems, such as high-dimensional Greenberger–Horne–Zeilinger states and their derivatives. Since photonic hardware is already on the edge of quantum supremacy and the development of gate-based quantum computers is rapidly advancing, our approach promises to be a useful tool for the future of quantum device design.
A new approach to the Fraser-Li conjecture with the Weierstrass representation formula
Authors: Lee Jaehoon , Yeon Eungbeom
Published: April 2021

In this paper, we provide a sufficient condition for a curve on a surface in

R

3

\mathbb {R}^3

to be given by an orthogonal intersection with a sphere. This result makes it possible to express the boundary condition entirely in terms of the Weierstrass data without integration when dealing with free boundary minimal surfaces in a ball

B

3

\mathbb {B}^3

. Moreover, we show that the Gauss map of an embedded free boundary minimal annulus is one to one. By using this, the Fraser-Li conjecture can be translated into the problem of determining the Gauss map. On the other hand, we show that the Liouville type boundary value problem in an annulus gives some new insight into the structure of immersed minimal annuli orthogonal to spheres. It also suggests a new PDE theoretic approach to the Fraser-Li conjecture.
Multiplicativity of perverse filtration for Hilbert schemes of fibered surfaces, II
Authors: Zhang Zili
Published: April 2021

Let

S
→
C

S\to C

be a smooth quasi-projective surface properly fibered onto a smooth curve. We prove that the multiplicativity of the perverse filtration on

H
∗

(

S

[
n
]

,

Q

)

H^*(S^{[n]},\mathbb {Q})

associated with the natural map

S

[
n
]

→

C

(
n
)

S^{[n]}\to C^{(n)}

implies that

S
→
C

S\to C

is an elliptic fibration. The converse is also true when

S
→
C

S\to C

is a Hitchin-type elliptic fibration.
Rates of Undiagnosed Hypertension and Diagnosed Hypertension Without Anti-hypertensive Medication Following the Affordable Care Act
Authors: Huguet Nathalie , Larson Annie , Angier Heather , Marino Miguel , Green Beverly B , Moreno Laura , DeVoe Jennifer E
Published: April 2021

Background

The Affordable Care Act (ACA) Medicaid expansion improved access to health insurance and health care services. This study assessed whether the rate of patients with undiagnosed hypertension and the rate of patients with hypertension without anti-hypertensive medication decreased post-ACA in community health center (CHC).

Methods

We analyzed electronic health record data from 2012 to 2017 for 126,699 CHC patients aged 19–64 years with ≥1 visit pre-ACA and ≥1 post-ACA in 14 Medicaid expansion states. We estimated the prevalence of patients with undiagnosed hypertension (high blood pressure reading without a diagnosis for ≥1 day) and the prevalence of patients with hypertension without anti-hypertensive medication by year and health insurance type (continuously uninsured, continuously insured, gained insurance, and discontinuously insured). We compared the time to diagnosis or to anti-hypertensive medication pre- vs. post-ACA.

Results

Overall, 37.3% of patients had undiagnosed hypertension and 27.0% of patients with diagnosed hypertension were without a prescribed anti-hypertensive medication for ≥1 day during the study period. The rate of undiagnosed hypertension decreased from 2012 through 2017. Those who gained insurance had the lowest rates of undiagnosed hypertension (2012: 14.8%; 2017: 6.1%). Patients with hypertension were also more likely to receive anti-hypertension medication during this period, especially uninsured patients who experienced the largest decline (from 47.0% to 8.1%). Post-ACA, among patients with undiagnosed hypertension, time to diagnosis was shorter for those who gained insurance than other insurance types.

Conclusions

Those who gained health insurance were appropriately diagnosed with hypertension faster and more frequently post-ACA than those with other insurance types.

Clinical trials registration

Trial Number NCT03545763.
Loosening chromatin and dysregulated transcription: a perspective on cryptic transcription during mammalian aging
Authors: McCauley Brenna S , Dang Weiwei
Published: April 2021

Cryptic transcription, the initiation of transcription from non-promoter regions within a gene body, is a type of transcriptional dysregulation that occurs throughout eukaryotes. In mammals, cryptic transcription is normally repressed at the level of chromatin, and this process is increased upon perturbation of complexes that increase intragenic histone H3 lysine 4 methylation or decrease intragenic H3 lysine 36 methylation, DNA methylation, or nucleosome occupancy. Significantly, similar changes to chromatin structure occur during aging, and, indeed, recent work indicates that cryptic transcription is elevated during aging in mammalian stem cells. Although increased cryptic transcription is known to promote aging in yeast, whether elevated cryptic transcription also contributes to mammalian aging is unclear. There is ample evidence that perturbations known to increase cryptic transcription are deleterious in embryonic and adult stem cells, and in some cases phenocopy certain aging phenotypes. Furthermore, an increase in cryptic transcription requires or impedes pathways that are known to have reduced function during aging, potentially exacerbating other aging phenotypes. Thus, we propose that increased cryptic transcription contributes to mammalian stem cell aging.
TOP-Plus Is a Versatile Biosensor Platform for Monitoring SARS-CoV-2 Antibody Durability
Authors: Racine-Brzostek Sabrina E , Karbaschi Mohsen , Gaebler Christian , Klasse P J , Yee Jim , Caskey Marina , Yang He S , Hao Ying , Sukhu Ashley , Rand Sophie , Chadburn Amy , Shi Yuanyuan , Zuk Robert , Nussenzweig Michel C , Cushing Melissa M , Zhao Zhen
Published: April 2021

Background

Low initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody titers dropping to undetectable levels within months after infection have raised concerns about long-term immunity. Both the antibody levels and the avidity of the antibody–antigen interaction should be examined to understand the quality of the antibody response.

Methods

A testing-on-a-probe “plus” panel (TOP-Plus) was developed to include a newly developed avidity assay built into the previously described SARS-CoV-2 TOP assays that measured total antibody (TAb), surrogate neutralizing antibody (SNAb), IgM, and IgG on a versatile biosensor platform. TAb and SNAb levels were compared with avidity in previously infected individuals at 1.3 and 6.2 months after infection in paired samples from 80 patients with coronavirus disease 2019 (COVID-19). Sera from individuals vaccinated for SARS-CoV-2 were also evaluated for antibody avidity.

Results

The newly designed avidity assay in this TOP panel correlated well with a reference Bio-Layer Interferometry avidity assay (r = 0.88). The imprecision of the TOP avidity assay was <10%. Although TAb and neutralization activity (by SNAb) decreased between 1.3 and 6.2 months after infection, the antibody avidity increased significantly (P < 0.0001). Antibody avidity in 10 SARS-CoV-2 vaccinated individuals (median: 28 days after vaccination) was comparable to the measured antibody avidity in infected individuals (median: 26 days after infection).

Conclusions

This highly precise and versatile TOP-Plus panel with the ability to measure SARS-CoV-2 TAb, SNAb, IgG, and IgM antibody levels and avidity of individual sera on one sensor can become a valuable asset in monitoring not only patients infected with SARS-CoV-2 but also the status of individuals’ COVID-19 vaccination response.
Assortativity measures for weighted and directed networks
Authors: Yuan Yelie , Yan Jun , Zhang Panpan
Published: April 2021

Assortativity measures the tendency of a vertex in a network being connected by other vertexes with respect to some vertex-specific features. Classical assortativity coefficients are defined for unweighted and undirected networks with respect to vertex degree. We propose a class of assortativity coefficients that capture the assortative characteristics and structure of weighted and directed networks more precisely. The vertex-to-vertex strength correlation is used as an example, but the proposed measure can be applied to any pair of vertex-specific features. The effectiveness of the proposed measure is assessed through extensive simulations based on prevalent random network models in comparison with existing assortativity measures. In application to World Input–Output Networks, the new measures reveal interesting insights that would not be obtained by using existing ones. An implementation is publicly available in a R package wdnet.
The benefits of being dominant: health correlates of male social rank and age in a marmot
Authors: Uchida Kenta , Ng Rachel , Vydro Samuel A , Smith Jennifer E , Blumstein Daniel T
Published: April 2021

The benefits of dominance may not come without costs, particularly for males. For example, the “immunocompetence handicap hypothesis” states that males with enhanced mating success allocate resources to enhance reproductive output at a cost to their current health, whereas the “resource quality hypothesis” predicts that high-ranking males may benefit from increased reproduction and good health. Whereas the predictions from each have been well tested in captive animals and in a variety of highly social primates, fewer studies have been carried out in free-living, facultatively social animals. Using adult male yellow-bellied marmots (Marmota flaviventer), we evaluated predictions of these hypotheses by examining the relationship between social rank and 2 health indicators—fecal glucocorticoid metabolite (FCM) levels, and neutrophil/lymphocyte (N/L) ratios—after accounting for variation explained by age, body mass, and seasonality. We found that higher-ranking males tended to have a lower N/L ratio (reflecting good health) than lower-ranking individuals, whereas FCM levels were not significantly related to rank. In addition, heavier male marmots had lower N/L ratios, whereas body mass was not associated with FCM levels. We also found that older adult males had lower FCM levels (reflecting less physiological stress) but higher N/L ratios than younger adults. Finally, we found that FCM levels decreased as the active season progressed and FCM levels were associated with the time of the day. Overall, our results suggest that socially-dominant male marmots enjoyed better, not worse health in terms of lower N/L ratios.
Gestational diabetes among women of migrant origin in Finland—a population-based study
Authors: Bastola Kalpana , Koponen Päivikki , Skogberg Natalia , Gissler Mika , Kinnunen Tarja I
Published: April 2021

Background

Migrant women may have a higher risk for gestational diabetes mellitus (GDM) and the related adverse outcomes. We studied the prevalence of GDM among migrant-origin women in Finland.

Methods

This study used data from the nationwide Medical Birth Register. Information on the most recent singleton births of women delivering between 2004 and 2014 (N = 379 634) was included. Women were classified into nine regional categories based on the country of origin. Finnish origin women were the reference group. Generalized linear models adjusted for maternal age, parity, socioeconomic position, pre-pregnancy body mass index and year of delivery were used to study the association between region/country of origin and GDM.

Results

Among the study population, almost 8% were of migrant origin. The prevalence of GDM varied from 6.1% (women of Latin American/Caribbean origin) to 18.4% (South Asian origin), compared to 8.7% in the Finnish reference group. When adjusted for confounders, women of South Asian, East Asian, Middle Eastern/North African and Russian/former USSR origin had a higher risk for GDM than Finnish origin women. By country of origin, women originating from Pakistan, Bangladesh, Sri Lanka, India, Afghanistan, Nepal, China, Philippines, Vietnam, Thailand, Morocco, Turkey, Iran, Iraq and former USSR had a higher risk for GDM than Finnish origin women.

Conclusions

There is substantial variation in the prevalence of GDM by country of origin. Women of South Asian, East Asian and Middle Eastern/North African origin had the highest risk for GDM and may warrant special attention.
Combining Different Line Crosses for Mapping Quantitative Trait Loci Using the Identical by Descent-Based Variance Component Method
Authors: Xie Chongqing , Gessler Damian D G , Xu Shizhong
Published: April 2021

Mapping quantitative trait loci (QTLs) is usually conducted with a single line cross. The power of such QTL mapping depends highly on the two parental lines. If the two lines are fixed for the same allele at a putative QTL, the QTL is undetectable. On the other hand, if a QTL is segregating in the line cross and is detected, the estimated variance of the QTL cannot be extrapolated beyond the statistical inference space of the two parental lines. To reduce the likelihood of missing a QTL and to increase the statistical inference space of the estimated QTL variance, we present a consensus QTL mapping strategy. We adopt the identical by descent (IBD)-based variance component method originally applied to human linkage analysis by combining multiple line crosses as independent families. We explore the properties of consensus QTL mapping and demonstrate the method with F2, backcross (BC), and full-sib (FS) families. In addition, we examine the effects of the QTL heritability, marker informativeness, QTL position, the number of families, and family size. We show that F2 families notably outperform BC and FS families in detecting a QTL. There is a substantial reduction in the standard deviation of the estimated QTL position and the separation of the QTL and polygenic variance. Finally, we show that the power to detect a QTL is greater when using a small number of large families than a large number of small families.
Coordination of Phytochrome Levels in phyB Mutants of Arabidopsis as Revealed by Apoprotein-Specific Monoclonal Antibodies
Authors: Hirschfeld Matthew , Tepperman James M , Clack Ted , Quail Peter H , Sharrock Robert A
Published: April 2021

Accumulating evidence indicates that individual members of the phytochrome family of photoreceptors have differential but interactive roles in controlling plant responses to light. To investigate possible cross-regulation of these receptors, we have identified monoclonal antibodies that specifically detect each of the five Arabidopsis phytochromes, phyA to phyE (phytochrome A holoprotein; PHYA, phytochrome A apoprotein; PHYA, phytochrome A gene; phyA, mutant allele of phytochrome A gene), on immunoblots and have used them to analyze the effects of phyA and phyB null mutations on the levels of all five family members. In phyB mutants, but not in phyA mutants, a four- to six-fold reduction in the level of phyC is observed in tissues grown either in the dark or in the light. Coordinate expression of phyB and phyC is induced in the phyB mutant background by the presence of a complementing PHYB transgene. However, in transgenic lines that overexpress phyB 15- to 20-fold, phyC is not similarly overexpressed. In these overexpressor lines, the levels of phyA, phyC, and phyD are increased two- to four-fold over normal in light-grown but not dark-grown seedlings. These observations indicate that molecular mechanisms for coordination or cross-regulation of phytochrome levels are active in Arabidopsis and have implications for the interpretation of phytochrome mutants and overexpressor lines.
The TERMINAL FLOWER2 (TFL2) Gene Controls the Reproductive Transition and Meristem Identity in Arabidopsis thaliana
Authors: Larsson Annika Sundås , Landberg Katarina , Meeks-Wagner D R
Published: April 2021

A new mutant of Arabidopsis thaliana that initiates flowering early and terminates the inflorescence with floral structures has been identified and named terminal flower2 (tfl2). While these phenotypes are similar to that of the terminal flower1 (tfl1) mutant, tfl2 mutant plants are also dwarfed in appearance, have reduced photoperiod sensitivity and have a more variable terminal flower structure. Under long-day and short-day growth conditions tfl1 tfl2 double mutants terminate the inflorescence without development of lateral flowers; thus, unlike tfl1 single mutants the double mutant inflorescence morphology is not affected by day length. The enhanced phenotype of the double mutant suggests that TFL2 acts in a developmental pathway distinct from TFL1. The complex nature of the tfl2 single mutant phenotype suggests that TFL2 has a regulatory role more global than that of TFL1. Double mutant analysis of tfl2 in combination with mutant alleles of the floral meristem identity genes LEAFY and APETALA1 demonstrates that TFL2 function influences developmental processes controlled by APETALA1, but not those regulated by LEAFY. Thus, the TFL2 gene product appears to have a dual role in regulating meristem activity, one being to regulate the meristem response to light signals affecting the development of the plant and the other being the maintenance of inflorescence meristem identity.
Molecular Organization of the 20S Proteasome Gene Family from Arabidopsis thaliana
Authors: Fu Hongyong , Doelling Jed H , Arendt Cassandra S , Hochstrasser Mark , Vierstra Richard D
Published: April 2021

The 20S proteasome is the proteolytic complex in eukaryotes responsible for degrading short-lived and abnormal intracellular proteins, especially those targeted by ubiquitin conjugation. The 700-kD complex exists as a hollow cylinder comprising four stacked rings with the catalytic sites located in the lumen. The two outer rings and the two inner rings are composed of seven different α and β polypeptides, respectively, giving an α7/β7/β7/α7 symmetric organization. Here we describe the molecular organization of the 20S proteasome from the plant Arabidopsis thaliana. From an analysis of a collection of cDNA and genomic clones, we identified a superfamily of 23 genes encoding all 14 of the Arabidopsis proteasome subunits, designated PAA-PAG and PBA-PBG for Proteasome Alpha and Beta subunits A–G, respectively. Four of the subunits likely are encoded by single genes, and the remaining subunits are encoded by families of at least 2 genes. Expression of the α and β subunit genes appears to be coordinately regulated. Three of the nine Arabidopsis proteasome subunit genes tested, PAC1 (α3), PAE1 (α5) and PBC2 (β3), could functionally replace their yeast orthologs, providing the first evidence for cross-species complementation of 20S subunit genes. Taken together, these results demonstrate that the 20S proteasome is structurally and functionally conserved among eukaryotes and suggest that the subunit arrangement of the Arabidopsis 20S proteasome is similar if not identical to that recently determined for the yeast complex.
Characterization of the Putative Transposase mRNA of Tag1, Which Is Ubiquitously Expressed in Arabidopsis and Can Be Induced by Agrobacterium-Mediated Transformation With dTag1 DNA
Authors: Liu Dong , Crawford Nigel M
Published: April 2021

Tag1 is an autonomous transposable element of Arabidopsis thaliana. Tag1 expression was examined in two ecotypes of Arabidopsis (Columbia and No-0) that were transformed with CaMV 35S-Tag1-GUS DNA. These ecotypes contain no endogenous Tag1 elements. A major 2.3-kb and several minor transcripts were detected in all major organs of the plants. The major transcript encoded a putative transposase of 84.2 kD with two nuclear localization signal sequences and a region conserved among transposases of the Ac or hAT family of elements. The abundance of Tag1 transcripts varied among transgenic lines and did not correlate with somatic excision frequency or germinal reversion rates, suggesting that factors other than transcript levels control Tag1 excision activity. In untransformed plants of the Landsberg ecotype, which contain two endogenous Tag1 elements, no Tag1 transcripts were detected. Agrobacterium-mediated transformation of these Landsberg plants with a defective 1.4-kb Tag1 element resulted in the appearance of full-length Tag1 transcripts from the endogenous elements. Transformation with control DNA containing no Tag1 sequences did not activate endogenous Tag1 expression. These results indicate that Agrobacterium-mediated transformation with dTag1 can activate the expression of Tag1.
Detection of Deleterious Genotypes in Multigenerational Studies. II. Theoretical and Experimental Dynamics with Selfing and Selection
Authors: Asmussen Marjorie A , Gilliland Laura U , Meagher Richard B
Published: April 2021

A mathematical model was developed to help interpret genotype and allele frequency dynamics in selfing populations, with or without apomixis. Our analysis provided explicit time-dependent solutions for the frequencies at diallelic loci in diploid populations under any combination of fertility, viability, and gametic selection through meiotic drive. With no outcrossing, allelic variation is always maintained under gametic selection alone, but with any fertility or viability differences, variation will ordinarily be maintained if and only if the net fitness (fertility × viability) of heterozygotes exceeds that of both homozygotes by a substantial margin. Under pure selfing and Mendelian segregation, heterozygotes must have a twofold fitness advantage; the level of overdominance necessary to preserve genetic diversity declines with apomixis, and increases with segregation distortion if this occurs equally and independently in male and female gametes. A case study was made of the Arabidopsis act2-1 actin mutant over multiple generations initiated from a heterozygous plant. The observed genotypic frequency dynamics were consistent with those predicted by our model for a deleterious, incompletely recessive mutant in either fertility or viability. The theoretical framework developed here should be very useful in dissecting the form(s) and strength of selection on diploid genotypes in populations with negligible levels of outcrossing.
Molecular Evolution of Genes Controlling Petal and Stamen Development: Duplication and Divergence Within the APETALA3 and PISTILLATA MADS-Box Gene Lineages
Authors: Kramer Elena M , Dorit Robert L , Irish Vivian F
Published: April 2021

The specification of floral organ identity in the higher dicots depends on the function of a limited set of homeotic genes, many of them members of the MADS-box gene family. Two such genes, APETALA3 (AP3) and PISTILLATA (PI), are required for petal and stamen identity in Arabidopsis; their orthologs in Antirrhinum exhibit similar functions. To understand how changes in these genes may have influenced the morphological evolution of petals and stamens, we have cloned twenty-six homologs of the AP3 and PI genes from two higher eudicot and eleven lower eudicot and magnolid dicot species. The sequences of these genes reveal the presence of characteristic PI- and AP3-specific motifs. While the PI-specific motif is found in all of the PI genes characterized to date, the lower eudicot and magnolid dicot AP3 homologs contain distinctly different motifs from those seen in the higher eudicots. An analysis of all the available AP3 and PI sequences uncovers multiple duplication events within each of the two gene lineages. A major duplication event in the AP3 lineage coincides with the base of the higher eudicot radiation and may reflect the evolution of a petal-specific AP3 function in the higher eudicot lineage.
A Nucleolar Protein That Affects Mating Efficiency in Saccharomyces cerevisiae by Altering the Morphological Response to Pheromone
Authors: Kim Jinah , Hirsch Jeanne P
Published: April 2021

SSF1 and SSF2 are redundant essential yeast genes that, when overexpressed, increase the mating efficiency of cells containing a defective Ste4p Gβ subunit. To identify the precise function of these genes in mating, different responses to pheromone were assayed in cells that either lacked or overexpressed SSF gene products. Cells containing null alleles of both SSF1 and SSF2 displayed the normal transcriptional induction response to pheromone but were unable to form mating projections. Overexpression of SSF1 conferred the ability to form mating projections on cells containing a temperature-sensitive STE4 allele, but had only a small effect on transcriptional induction. SSF1 overexpression preferentially increased the mating efficiency of a strain containing a null allele of SPA2, a gene that functions specifically in cell morphology. To investigate whether Ssf1p plays a direct physical role in mating projection formation, its subcellular location was determined. An Ssf1p-GFP fusion was found to localize to the nucleolus, implying that the role of SSF gene products in projection formation is indirect. The region of Ssf1p-GFP localization in cells undergoing projection formation was larger and more diffuse, and was often present in a specific orientation with respect to the projection. Although the function of Ssf1p appears to originate in the nucleus, it is likely that it ultimately acts on one or more of the proteins that is directly involved in the morphological response to pheromone. Because many of the proteins required for projection formation during mating are also required for bud formation during vegetative growth, regulation of the activity or amount of one or more of these proteins by Ssf1p could explain its role in both mating and dividing cells.
Involvement of Protein N-Glycosyl Chain Glucosylation and Processing in the Biosynthesis of Cell Wall β-1,6-Glucan of Saccharomyces cerevisiae
Authors: Shahinian Serge , Dijkgraaf Gerrit J P , Sdicu Anne-Marie , Thomas David Y , Jakob Claude A , Aebi Markus , Bussey Howard
Published: April 2021

β-1,6-Glucan plays a key structural role in the yeast cell wall. Of the genes involved in its biosynthesis, the activity of Cwh41p is known, i.e., the glucosidase I enzyme of protein N-chain glucose processing. We therefore examined the effects of N-chain glucosylation and processing mutants on β-1,6-glucan biosynthesis and show that incomplete N-chain glucose processing results in a loss of β-1,6-glucan, demonstrating a relationship between N-chain glucosylation/processing and β-1,6-glucan biosynthesis. To explore the involvement of other N-chain-dependent events with β-1,6-glucan synthesis, we investigated the Saccharomyces cerevisiae KRE5 and CNE1 genes, which encode homologs of the “quality control” components UDP-Glc:glycoprotein glucosyltransferase and calnexin, respectively. We show that the essential activity of Kre5p is separate from its possible role as a UDP-Glc:glycoprotein glucosyltransferase. We also observe a ~30% decrease in β-1,6-glucan upon disruption of the CNE1 gene, a phenotype that is additive with other β-1,6-glucan synthetic mutants. Analysis of the cell wall anchorage of the mannoprotein α-agglutinin suggests the existence of two β-1,6-glucan biosynthetic pathways, one N-chain dependent, the other involving protein glycosylphosphatidylinositol modification.
The mod-A Suppressor of Nonallelic Heterokaryon Incompatibility in Podospora anserina Encodes a Proline-Rich Polypeptide Involved in Female Organ Formation
Authors: Barreau Christian , Iskandar Maya , Loubradou Gabriel , Levallois Véronique , Bégueret Joël
Published: April 2021

Vegetative incompatibility in fungi results from the control of heterokaryon formation by the genes present at het loci. Coexpression of antagonistic het genes in the same hyphae leads to a lethal process. In Podospora anserina, self-incompatible strains containing nonallelic incompatible genes in the same nucleus are inviable as the result of a growth arrest and a lytic process. Mutations in suppressor genes (mod genes) can restore the viability. These mod mutations also interfere with developmental processes, which suggests common steps between the incompatibility reaction and cellular differentiation. The mod-A locus, responsible for growth arrest in the self-incompatible strains, is also involved in the control of the development of female organs. The mod-A gene was isolated. An open reading frame 687 amino acids long was identified. The MOD-A-encoded polypeptide is rich in proline residues, which are clustered in a domain containing a motif that displays similarity to SH3-binding motifs, which are known to be involved in protein-protein interactions. Construction of a strain deleted for mod-A confirmed that the product of this gene involved in differentiation is a key regulator of growth arrest associated with vegetative incompatibility.
Isolation and Characterization of New Fission Yeast Cytokinesis Mutants
Authors: Balasubramanian Mohan K , McCollum Dannel , Chang Louise , Wong Kelvin C Y , Naqvi Naweed I , He Xiangwei , Sazer Shelley , Gould Kathleen L
Published: April 2021

Schizosaccharomyces pombe is an excellent organism in which to study cytokinesis as it divides by medial fission using an F-actin contractile ring. To enhance our understanding of the cell division process, a large genetic screen was carried out in which 17 genetic loci essential for cytokinesis were identified, 5 of which are novel. Mutants identifying three genes, rng3+, rng4+, and rng5+, were defective in organizing an actin contractile ring. Four mutants defective in septum deposition, septum initiation defective (sid)1, sid2, sid3, and sid4, were also identified and characterized. Genetic analyses revealed that the sid mutants display strong negative interactions with the previously described septation mutants cdc7-24, cdc11-123, and cdc14-118. The rng5+, sid2+, and sid3+ genes were cloned and shown to encode Myo2p (a myosin heavy chain), a protein kinase related to budding yeast Dbf2p, and Spg1p, a GTP binding protein that is a member of the ras superfamily of GTPases, respectively. The ability of Spg1p to promote septum formation from any point in the cell cycle depends on the activity of Sid4p. In addition, we have characterized a phenotype that has not been described previously in cytokinesis mutants, namely the failure to reorganize actin patches to the medial region of the cell in preparation for septum formation.
Courtship and Visual Defects of cacophony Mutants Reveal Functional Complexity of a Calcium-Channel α1 Subunit in Drosophila
Authors: Smith Lee A , Peixoto Alexandre A , Kramer Elena M , Villella Adriana , Hall Jeffrey C
Published: April 2021

We show by molecular analysis of behavioral and physiological mutants that the Drosophila Dmca1A calcium-channel α1 subunit is encoded by the cacophony (cac) gene and that nightblind-A and lethal(1)L13 mutations are allelic to cac with respect to an expanded array of behavioral and physiological phenotypes associated with this gene. The cacS mutant, which exhibits defects in the patterning of courtship lovesong and a newly revealed but subtle abnormality in visual physiology, is mutated such that a highly conserved phenylalanine (in one of the quasi-homologous intrapolypeptide regions called IIIS6) is replaced by isoleucine. The cacH18 mutant exhibits defects in visual physiology (including complete unresponsiveness to light in certain genetic combinations) and visually mediated behaviors; this mutant (originally nbAH18) has a stop codon in an alternative exon (within the cac ORF), which is differentially expressed in the eye. Analysis ofthe various courtship and visual phenotypes associated with this array ofcac mutants demonstrates that Dmca1A calcium channels mediate multiple, separable biological functions; these correlate in part with transcript diversity generated via alternative splicing.
Molecular Screening for P-Element Insertions in a Large Genomic Region of Drosophila melanogaster Using Polymerase Chain Reaction Mediated by the Vectorette
Authors: Eggert Harald , Bergemann Kirstin , Saumweber Harald
Published: April 2021

As an alternative to existing methods for the detection of new insertions during a transposon mutagenesis, we adapted the method of vectorette ligation to genomic restriction fragments followed by PCR to obtain genomic sequences flanking the transposon. By combining flies containing a defined genomic transposon with an excess of flies containing unrelated insertion sites, we demonstrate the specificity and sensitivity of the procedure in the detection of integration events. This method was applied in a transposon-tagging screen for BJ1, the Drosophila homolog of the vertebrate gene Regulator of Chromosome Condensation (RCCI). Genetic mobilization of a single genomic P element was used to generate preferentially new local insertions from which integrations into a genomic region surrounding the BJ1 gene were screened. Flies harboring new insertions were phenotypically selected on the basis of the zeste1-dependent transvection of white. We detected a single transposition to a 13-kb region close to the BJ1 gene among 6650 progeny that were analyzed. Southern analysis of the homozygous line confirmed the integration 3 kb downstream of BJ1.
Drosophila Hormone Receptor 38 Functions in Metamorphosis: A Role in Adult Cuticle Formation
Authors: Kozlova T , Pokholkova G V , Tzertzinis G , Sutherland J D , Zhimulev I F , Kafatos F C
Published: April 2021

DHR38 is a member of the steroid receptor superfamily in Drosophila homologous to the vertebrate NGFI-B-type orphan receptors. In addition to binding to specific response elements as a monomer, DHR38 interacts with the USP component of the ecdysone receptor complex in vitro, in yeast and in a cell line, suggesting that DHR38 might modulate ecdysone-triggered signals in the fly. We characterized the molecular structure and expression of the Dhr38 gene and initiated an in vivo analysis of its function(s) in development. The Dhr38 transcription unit spans more than 40 kb in length, includes four introns, and produces at least four mRNA isoforms differentially expressed in development; two of these are greatly enriched in the pupal stage and encode nested polypeptides. We characterized four alleles of Dhr38: a P-element enchancer trap line, l(2)02306, which shows exclusively epidermal staining in the late larval, pre-pupal and pupal stages, and three EMS-induced alleles. Dhr38 alleles cause localized fragility and rupturing of the adult cuticle, demonstrating that Dhr38 plays an important role in late stages of epidermal metamorphosis.