bluuebunny/crossref_metadata_2025 huggingface dataset:
Tithonia diversifolia (Mexican sunflower).
Authors: Rojas-Sandoval Julissa , Winnifred Aool , Morris Opio Samuel
Published: April 2021

Tithonia diversifolia is a herbaceous flowering plant that has been widely introduced as an ornamental and has escaped from cultivation to become invasive, mostly in disturbed sites, along roadsides and in ruderal areas near cultivation. T. diversifolia is a successful invader of new habitats through its tolerance to heat and drought, its rapid growth rates and its large production of lightweight seeds which are easily dispersed by wind, water and animals. Dormant seeds also remain viable in the soil for up to four months. Once established, T. diversifolia quickly forms dense stands with the potential to outcompete native vegetation and thus prevent the recruitment and growth of native plant species. Allelopathic activity has also been reported for this species.
Crocosmia x crocosmiiflora (montbretia).
Authors: Rojas-Sandoval Julissa
Published: April 2021

Crocosmia × crocosmiiflora has been widely cultivated as an ornamental and has escaped from cultivation to become invasive in disturbed sites, riverbanks, wasteland, along roadsides, and shrublands (Ensbey et al., 2011; Weeds of Australia, 2016, Weeds of New Zealand, 2016). This species is well adapted to grow in a wide range of environmental conditions and soil types (it may grow in any soil, wet or dry, poor or rich). It competes aggressively with native vegetation for resources such as water and nutrients and it has the potential to displace native vegetation primarily in riparian areas and moist shrublands. Once established, it moves rapidly down watercourses into natural forests. The mass of corms in the soil contributes to the breakdown and erosion of natural creek and riverbanks (Ensbey et al., 2011; Weeds of the Blue Mountains, 2016).
Adonidia merrillii (Christmas palm).
Authors: Rojas-Sandoval Julissa
Published: April 2021

Adonidia merrillii is one of the most popular ornamental palms worldwide. Native to the Philippines and Malaysia, it has been extensively introduced, mostly in tropical regions but also as an indoor plant in subtropical and temperate areas. Currently it is listed as invasive in Cuba, the Bahamas and Anguilla. On these islands, this palm species has escaped cultivation and is now competing with native plant species. Because A. merrillii is highly susceptible to lethal yellowing disease, it is considered a threat for the conservation of native palm species in the Bahamas.
Zoysia matrella (Manila grass).
Authors: Kaufman Sylvan
Published: April 2021

Z. matrella is a warm season grass which has been widely planted as a turf grass in tropical and subtropical regions around the world and has naturalized mainly close to where it was planted in disturbed areas. It grows slowly and primarily spreads by rhizomes and stolons, but could also spread by seed. There is no information available on its impacts. It forms dense stands and could displace native species through competition for resources.
Desmodium cajanifolium (tropical tick trefoil).
Authors: Vélez-Gavilán Jeanine
Published: April 2021

Desmodium cajanifolium is a perennial shrub considered as invasive in Hawaii, USA, by Frohlich and Lau (2012), who reported it as a weedy species naturalised along roadsides, open forests and secondary vegetation on the Big Island and Kaua'i. At the same time, Benitez et al. (2012) report D. cajanifolium as a species that is rarely found along roadsides and in forests in Hawaii. D. cajanifolium is not listed as an invasive species on Pacific Islands Ecosystems at Risk (PIER, 2020). No details about its effects over other species or habitats are given.Desmodium cajanifolium is listed as potentially invasive in Cuba, being classified as a species with a tendency to proliferate in some areas and producing vast amounts of diaspores with a high dispersal capacity (Oviedo Prieto et al., 2012). It is considered as uncommon in parts of its native distribution (Flora of Nicaragua, 2020) and as scattered throughout its range (Flora of Panama, 2020).
Bambusa tuldoides (punting pole bamboo).
Authors: Rojas-Sandoval Julissa
Published: April 2021

Bambusa tuldoides is a species of bamboo native to Asia that is is widely cultivated as ornamental and hedge plant but also for its culms. It has been introduced elsewhere in Asia outside of its native range, as well as in the Americas and Pacific region. Culms and branches root very readily and often grow to form monospecific stands along riverbanks, low hills, roadsides and disturbed sites. This species is adapted to grow in a wide range of climates and can survive temperatures as low as -7°C. Currently, B. tuldoides is considered an invasive and transformer species in Cuba. It is also included in the Global Compendium of weeds as an "agricultural weed".
A TRCky TA protein delivery service snubs the UPS
Authors: McQuown Alexander J. , Reif Dvir , Denic Vladimir
Published: April 2021

In mammals, tail-anchored (TA) proteins that are posttranslationally captured by the chaperone SGTA are triaged by the BAG6 complex into one of two fates: handoff to an ER targeting factor for membrane insertion or polyubiquitination for destruction by the proteasome. In this issue, Culver and Mariappan (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202004086) show that a fraction of newly synthesized TA proteins is polyubiquitinated in HEK293 cells independently of the BAG6 complex yet evades proteasomal degradation by undergoing deubiquitination en route to becoming stably inserted into the ER membrane.
Temperature-dependent near-surface interstitial segregation in niobium
Authors: Dalla Lana Semione Guilherme , Vonk Vedran , Pandey Arti Dangwal , Grånäs Elin , Arndt Björn , Wenskat Marc , Hillert Wolfgang , Noei Heshmat , Stierle Andreas
Published: April 2021

Niobium’s superconducting properties are affected by the presence and precipitation of impurities in the near-surface region. A systematic wide-temperature range x-ray diffraction study is presented addressing the effect of low temperatures (108 K–130 K) and annealing treatments (523 K in nitrogen atmosphere, 400 K in UHV) on the near-surface region of a hydrogen-loaded Nb(100) single-crystal. Under these conditions, the response of the natural surface oxides (Nb2O5, NbO2, and NbO) and the changes in the subsurface concentration of interstitial species in Nb are explored, thereby including the cryogenic temperature regime relevant for device operation. The formation and suppression of niobium hydrides in such conditions are also investigated. These treatments are shown to result in: (i) an increase in the concentration of interstitial species (oxygen and nitrogen) occupying the octahedral sites of the Nb bcc lattice at room temperature, both in the near-surface region and in the bulk. (ii) A decrease in the concentration of interstitials within the first 10 nm from the surface at 130 K. (iii) Hydride formation suppression at temperatures as low as 130 K. These results show that mild annealing in nitrogen atmosphere can suppress the formation of superconducting-detrimental niobium hydrides, while subsurface interstitial atoms tend to segregate towards the surface at 130 K, therefore altering the local concentration of impurities within the RF penetration depth of Nb. These processes are discussed in the context of the improvement of niobium superconducting radio-frequency cavities for next-generation particle accelerators.
Electronic and crystal structures of LnFeAsO1−x
H
x
(Ln = La, Sm) studied by x-ray absorption spectroscopy, x-ray emission spectroscopy, and x-ray diffraction (part I: carrier-doping dependence)
Authors: Yamamoto Yoshiya , Yamaoka Hitoshi , Uozumi Takayuki , Hariki Atsushi , Onari Seiichiro , Yamaura Jun-ichi , Ishii Kenji , Kawai Takuma , Yoshida Masahiro , Taguchi Munetaka , Kobayashi Kensuke , Lin Jung-Fu , Hiraoka Nozomu , Ishii Hirofumi , Tsuei Ku-Ding , Okanishi Hiroshi , Iimura Soshi , Matsuishi Satoru , Hosono Hideo , Mizuki Jun’ichiro
Published: April 2021

A carrier doping by a hydrogen substitution in LaFeAsO1−x
H
x
is known to cause two superconducting (SC) domes with the magnetic order at both end sides of the doping. In contrast, SmFeAsO1−x
H
x
has a similar phase diagram but shows single SC dome. Here, we investigated the electronic and crystal structures for iron oxynitride LnFeAsO1−x
H
x
(Ln = La, Sm) with the range of x = 0–0.5 by using x-ray absorption spectroscopy, x-ray emission spectroscopy, and x-ray diffraction. For both compounds, we observed that the pre-edge peaks of x-ray absorption spectra near the Fe-K edge were reduced in intensity on doping. The character arises from the weaker As–Fe hybridization with the longer As–Fe distance in the higher doped region. We can reproduce the spectra near the Fe-K edge according to the Anderson impurity model with realistic valence structures using the local-density approximation (LDA) plus dynamical mean-field theory (DMFT). For Ln = Sm, the integrated-absolute difference (IAD) analysis from x-ray Fe-Kβ emission spectra increases significantly. This is attributed to the enhancement of magnetic moment of Fe 3d electrons stemming from the localized picture in the higher doped region. A theoretical simulation implementing the self-consistent vertex-correction method reveals that the single dome superconducting phase for Ln = Sm arises from a better nesting condition in comparison with Ln = La.
Analysis of electron acoustic waves interaction in the presence of homogeneous unmagnetized collision-free plasma
Authors: Jhangeer Adil , Munawar Maham , Atangana Abdon , Bilal Riaz Muhammad
Published: April 2021

In this research, the transmission and interaction of nonlinear electron acoustic waves (EAWs) in such an unmagnetized, homogeneous, collision-free plasma composed of hot and cold electrons together with stationary ions throughout in the background have been analyzed. For the small-amplitude limit, the Korteweg–de Vries (KdV) equation for (EAWs) have been extracted. For electron acoustic solitary waves (EASWs), using the new extended direct algebraic approach, soliton solutions have also documented. The parametric analysis demonstrated that the hot to cold electron ratio and hot electron superthermal play a key role in changing the (EASWs) amplitude. The family of semi-bright solitons, dark singular solitons, Type 1 as well as 2 single solitons, trigonometric, intermingled hyperbolic and rational solitons was constructed and tested with the assistance of the innovative package software of numerical computations. The results show that the method is clear and efficient, produces analytical results in a generalized form, and these findings can also help resolve the difficulties and predicaments in the relevant disciplines of plasma physics and may be useful for studying the relationship between two (EASWs) in astrophysical and laboratory plasma. The solutions presented in this prototype are the latest in a literature review. For physical interpretation, some randomly selected solutions are shown graphically. Conclusions are held at the end.
Scintillation analysis of Weber beam in atmospheric turbulence
Authors: Bayraktar Mert
Published: April 2021

This paper presents scintillation performance of Weber beam propagating in atmospheric turbulence. Weber beam is defined in parabolic cylindrical coordinates and it will be troublesome to solve analytically. Because of that reason, source field expression is converted into Cartesian coordinates and numerical atmospheric model is used. Our results indicate that Weber beam brings the advantage because scintillation index is substantially less as compared to spherical wave and Gaussian beam. It is possible to mitigate scintillation if Weber beam involving more and small intensities is generated. We anticipate that communication system designers will use outputs of this study.
Energy corrections due to the noncommutative phase-space of the charged isotropic harmonic oscillator in a uniform magnetic field in 3D
Authors: Eser Muhittin Cenk , Riza Mustafa
Published: April 2021

In this study, we investigate the effects of noncommutative Quantum Mechanics in three dimensions on the energy-levels of a charged isotropic harmonic oscillator in the presence of a uniform magnetic field in the z-direction. The extension of this problem to three dimensions proves to be non-trivial. We obtain the first-order corrections to the energy-levels in closed form in the low energy limit of weak noncommutativity. The most important result we can note is that all energy corrections due to noncommutativity are negative and their magnitude increase with increasing Quantum numbers and magnetic field.
The future of high-energy astrophysical neutrino flavor measurements
Authors: Song Ningqiang , Li Shirley Weishi , Argüelles Carlos A. , Bustamante Mauricio , Vincent Aaron C.
Published: April 2021

We critically examine the ability of future neutrino
telescopes, including Baikal-GVD, KM3NeT, P-ONE, TAMBO, and
IceCube-Gen2, to determine the flavor composition of high-energy
astrophysical neutrinos in light of data from next-generation of
neutrino oscillation experiments including JUNO, DUNE, and
Hyper-Kamiokande. By 2040, the region of allowed flavor composition
at Earth will shrink ten-fold, and the flavor composition at the
astrophysical sources of the neutrinos will be inferred to within
6%, enough to pinpoint the dominant neutrino production mechanism
and to identify possible sub-dominant mechanisms. These conclusions
hold even in the nonstandard scenario where neutrino mixing is
non-unitary, a scenario that will be probed in next-generation
experiments such as the IceCube-Upgrade. As an illustration, we show
that future experiments are sensitive to decay rates of the heavier
neutrinos to below 1.8 × 10-5 (m/eV) s-1 at
95% credibility by 2040.
Thermal Stresses in an Elastic Clamped Square: Exact Solution
Authors: Kerzhaev A P
Published: April 2021

This paper presents a method for determining thermal stresses in an elastic clamped square with a given temperature distribution (the plane problem). First, the solution to the temperature problem for an infinite plane is constructed. Then, the solution for a square is added to this solution, with the help of which the boundary conditions on its sides are satisfied. The thermal stresses have been obtained in the form of series in Papkovich–Fadle eigenfunctions, the coefficients of which are determined explicitly. The final formulas are simple and can easily be used in engineering.
Recommendation System Journalist For Getting Top News Based On Twitter Data
Authors: Girsang Abba Suganda , Isa Sani Muhamad , Harvy Ikrar
Published: April 2021

One application that can be utilized in finding the latest news is by utilizing the development of information and communication technology such as seeing the delivery of public information through social media such as twitter. This study implements the system which is able to get the trending or top news based on twitter data. This information will connect to the journalist via mobile application. It helps journalists to get the potential news to be reported in their media. The application will group each tweets into various themes based on the cosine similarity. The tweets which are more the certain threshold, can be indicated as the top news. The top news is then classified into one category news by using SVM algorithm. The training data becomes from the source data of one media news. The specific topic of this result will ease to order the journalist cover this top news. The system can be implemented well.
Quality Analysis the E-PASTI System to Determine the Condition of the System and Information Quality
Authors: Nugraha Bayu , Marleny Finki Dona , Sfenrianto Sfenrianto , Edwina Cinthya
Published: April 2021

The purpose of this study is to evaluate the quality of secretarial, financial and staffing information systems at the Directorate General of AHU, known as the E-PASTI system. There are two variables analysed, namely system quality and information quality. Data collection using questionnaires that distributed to 123 employees who used the E-PASTI system but returned 93 questionnaires. Data quality analyst uses descriptive quantitative method. The results of the study are several conditions related to the system and information quality of E-PASTI. The quality can be a reference for the AHU Directorate General to improve the quality of E-PASTI that suits the needs of employees.
Malware Detection: Issues and Challenges
Authors: Naseer Muchammad , Rusdi Jack Febrian , Shanono Nuruddeen Musa , Salam Sazilah , Muslim Zulkiflee Bin , Abu Nur Azman , Abadi Iwan
Published: April 2021

Malware is a severe threat that makes computer security more vulnerable. Many studies have been conducted to improve the capability of detection techniques. However, there is a lack of analysis of the current trend of IDS. This paper is about extracting and analyzing the latest detection techniques which had been conducted by various studies. This paper will also emphasize the current challenges of malware deployment from recent studies. Finally, the similarities and differences between the detection techniques will be exposed, and the issues and problems related to detection techniques will highlight as well. In the future, this paper outcome can be used to highlight the current topic addressed in malware research.
Interests Scale Based Online Application to Determining Major in University
Authors: Bil Haq Aniq Hudiyah , Kamaratih Dewi , Fahmi Gema Lara , Malada Eka , Kurniawan Yogiek Indra
Published: April 2021

Students who graduate from high school when entering college will definitely choose a course that suits their interests and expertise, but this sometimes makes many students confused. The choice of certain majors is often based on encouragement from parents, friends and the environment. Factors related to internal students regarding personality profiles and typologies of work are rarely a consideration for students in choosing majors in college. This is because identifying interests that are in accordance with personal circumstances requires psychological measuring devices or often referred to as psychological testing. The aims of this study to identify self interest student for majoring in programs study. The tool to identification is using online-based applications. Psychology that used paper and pencil is now using a computer application, so the results of this scale can be made recommendations for students who want to major in college. This compiled application is processed automatically so that it can give results quickly and accurately. The subjects in this study were 127 students who answered their questions in this application and assessed the appropriateness of this application in terms of convenience, the language used, whether there were terms understood and whether the results were as expected by students. 70,1% of students answered that this application was easy to understand and run. 96% of students answered this application using good language and 34% of students thought that there were some terms that were not understood and also 63% of students answered that the results of this application were in accordance with their personal circumstances. The implication of this research is the psychological testing can be used by computerize administration; instruction will be easier for the tester and the result from the testing faster. Hopefully this application can be used for the student in majoring a program study.
The Object Tracking System At The Service Delivery Center Of The Traveling Salesperson Problem Method
Authors: Hardi Richki , Suryana Nanna , Pee Naim Che , Pribadi Agung Sakti , Rusdi Jack Febrian , Junaidi Apri
Published: April 2021

Search object delivery is essential to investigate, especially for package delivery. The technology is beneficial to check whether the goods sent have arrived or not. Otherwise, it will be known where in real-time. This study aims to provide information to the shipping service, to choose the right and optimal shipping routes using the problem of the Travel Salesperson’s problem, because of that way. This method is rather difficult when viewed from a computational point of view, but TSP is made easy by trying all possible routes to get a solution or approaching the optimal path. The problem is how to determine the route according to the package that can get to the destination city in the shortest time possible by using that route, package which can reach a town or delivery center to each subsequent branch that matches the package to the postal receiving town with a minimum time limit. In other words, the shortest path and the path that the packet must pass from the sending post to the recipient must be determined.
Thermal analysis of HI-STORM 100S dry cask with the MELCOR code
Authors: Angelucci M , Herranz L E , Paci S
Published: April 2021

As spent nuclear fuel (SNF) pools are reaching their capacity, dry storage systems have been introduced worldwide as interim step before permanent deep underground disposal. Thermal behaviour of the SNF, and of the system containing it, has proven to be essential to ensure fuel rod integrity for the entire storage time. In the effort to achieve a proper characterization, this work investigates the capabilities of the lumped parameter MELCOR 2.2 code to model the thermal evolution of SNF in the scenario of a concrete-based dry cask. Being dry storage systems completely outside MELCOR domain of application, a number of approximations and hypotheses have been necessary, without however jeopardizing the real cask characteristics and behaviour. Results have been discussed to be coherent with what physically expected and verified against estimates previously obtained from a FLUENT calculation on the same system. The code shows the ability to well predict the Peak Cladding Temperature (PCT) and its location, as well as temperature radial profile; however, some discrepancies show up when analysing temperature profiles in the down-comer and in the air gap. For this reason, further assessment studies should be performed to confirm the potential shown in this preliminary work.
Experimental Assessment of Gas Static Meters Under Different Operating Conditions
Authors: Cascetta Furio , Bondesan Marcello , Musto Marilena , Rotondo Giuseppe
Published: April 2021

This paper compares the metrological performance of a sample of commercial domestic/residential smart meters for natural gas (G4). In particular, the performance degradation of electronic static and dynamic gas meters has been evaluated. The sample was composed by ultrasonic gas meters, thermal mass meters and diaphragm gas meters. The tests, performed on the gas meters, reproduce the most severe operating conditions (i.e. filed test) such as the influence of the gas composition, the temperature difference between gas and meter, the gas humidity and the presence of dust in the gas. Furthermore, the meters have been undergo to some endurance tests such as start and stop and to the high flowrate runs.
Experimental heat transfer evaluation in a porous media
Authors: Pedrazzi S , Allesina G , Puglia M , Morselli N , Ottani F , Parenti M , Tartarini P
Published: April 2021

The evaluation of the heat transfer coefficient between hot gases and biomass particles is not easy to estimate because of the concomitance of exothermic and endothermic reactions. However, a proper evaluation of this coefficient is fundamental to design pyrolysis apparatus. This paper presents an experimental study regarding wood pellets heating up in a batch reactor using hot exhaust gases from an engine. Temperature and flow of hot gases entering the reactor were measured over time. A first test was carried out using hemp hurd pellets with 15% of sawdust, and a second one using the carbonized pellets obtained from the previous test. Fresh pellets have a higher thermal capacity compared to carbonized pellets that is almost inert and follow a more regular heating trend. Heat transfer was calculated considering the energy released by the exhaust passing through the biomass as the sum of the energy absorbed by the pellets and the thermal losses. Convection is the predominant heat transfer mechanism and the convective heat transfer coefficient was evaluated. Finally, the energy for the pyrolysis of 1 kg of fuel was evaluated. About 0.7 kWh/kg are necessary to pyrolyze this kind of pellets while an heat transfer coefficient of 110 W/(m2K) was estimated for the inert packed bed.
Optimal sizing of an integrated energy system for a nearly zero-energy residential building
Authors: Franco Alessandro , Bartoli Carlo , Conti Paolo , Testi Daniele
Published: April 2021

The paper analyzes the design of a typical solution for a smart energy system. It examines a particular plant, evaluating the integration of a Photovoltaic (PV) system and a Ground-Source Heat Pump (GSHP) for residential building service. The idea is to develop a system that maximizes self-consumption of the renewable energy generated by a small-sized solar array installed on the building. The case is analyzed starting from the results of a long-term experimental analysis of a real plant in Pisa. The analysis concerns the energy balance of the system during a year with a special attention on the operation of the two different systems, PV array and GSHP. Some indications on the possible optimum design of this solution are proposed and discussed and analyzed.
Thermal characterization of a multilayer coating for seismic and energy building renovation
Authors: Pilotelli Mariagrazia , Levi Elisa , Neri Manuela
Published: April 2021

Many buildings built in Italy in the 60s and 70s need an energy requalification and at the same time an improvement of the seismic behaviour. A non-invasive method for a joint requalification consists of an anti-seismic plaster layer and a thermal coating. In this work, a multi-layer package of 3 cm of SFRM coating and 8 cm of wood fiber placed on a 20 cm masonry wall is analyzed. Numerical and experimental analysis allowed to characterize the wall, and to determine the influence of the connecting elements.
Acting rapidly to deploy readily available methane mitigation measures by sector can immediately slow global warming
Authors: Ocko Ilissa B , Sun Tianyi , Shindell Drew , Oppenheimer Michael , Hristov Alexander N , Pacala Stephen W , Mauzerall Denise L , Xu Yangyang , Hamburg Steven P
Published: April 2021

Methane mitigation is essential for addressing climate change, but the value of rapidly implementing available mitigation measures is not well understood. In this paper, we analyze the climate benefits of fast action to reduce methane emissions as compared to slower and delayed mitigation timelines. We find that the scale up and deployment of greatly underutilized but available mitigation measures will have significant near-term temperature benefits beyond that from slow or delayed action. Overall, strategies exist to cut global methane emissions from human activities in half within the next ten years and half of these strategies currently incur no net cost. Pursuing all mitigation measures now could slow the global-mean rate of near-term decadal warming by around 30%, avoid a quarter of a degree centigrade of additional global-mean warming by midcentury, and set ourselves on a path to avoid more than half a degree centigrade by end of century. On the other hand, slow implementation of these measures may result in an additional tenth of a degree of global-mean warming by midcentury and 5% faster warming rate (relative to fast action), and waiting to pursue these measures until midcentury may result in an additional two tenths of a degree centigrade by midcentury and 15% faster warming rate (relative to fast action). Slow or delayed methane action is viewed by many as reasonable given that current and on-the-horizon climate policies heavily emphasize actions that benefit the climate in the long-term, such as decarbonization and reaching net-zero emissions, whereas methane emitted over the next couple of decades will play a limited role in long-term warming. However, given that fast methane action can considerably limit climate damages in the near-term, it is urgent to scale up efforts and take advantage of this achievable and affordable opportunity as we simultaneously reduce carbon dioxide emissions.
Utilizing rainy season onset predictions to enhance maize yields in Ethiopia
Authors: Lala Jonathan , Yang Meijian , Wang Guiling , Block Paul
Published: April 2021

For countries dependent on rainfed agriculture, failure of the rainy season can lead to serious consequences on the broader economy. Maize, a common staple crop in these countries, often expresses significant interannual variability, given its high sensitivity to water stress. It is traditionally planted at rainy season onset to maximize the growing season and potential yield; however, this risks planting during a ‘false onset’ that can damage the crop or require replanting. Rainy season onset forecasts offer some promise in reducing this risk; however, the potential for increasing yield has not been explicitly quantified. This study quantifies the yield gap associated with suboptimal maize planting times using a process-based crop model over a 36 year historical period across Ethiopia. Onset-informed and forecast-informed approaches are compared with a baseline approach, and results indicate a strong potential for yield gains in drier regions as well as reductions in interannual variance countrywide. In contrast, regions with reliably sufficient precipitation illustrate only minimal gains. In general, integration of onset forecasts into agricultural decision-making warrants inclusion in agricultural extension efforts.
Classification of Land Cover in Kumamoto Area, Japan to Evaluate Infiltration and Surface Runoff
Authors: Amano H , Iwasaki Y , Ichikawa T
Published: April 2021

Almost 100% of domestic water is covered by groundwater in the Kumamoto region, Japan. However, in recent years, the groundwater recharge area (particularly paddy fields) has been significantly decreasing, and the groundwater level has been gradually dropping in some places. Aside from this, the groundwater level was abnormally changed as an impact of the 2016 Kumamoto earthquake. Our final goal is to build a model to represent the groundwater level change including the abnormal change. For this purpose, we generated a land cover map by using temporal Normalized Difference Vegetation Index (NDVI) changes based on Landsat-8 satellite images and Geographic Information System (GIS) data. Our classification results well expressed the actual land cover especially around rivers, lakes and buildings compared with the existing land cover map. The calculated infiltration and surface runoff amounts from grasslands with the different land uses indicated the importance of understanding not only land covers but also land uses to evaluate infiltration and surface runoff amounts.
Load distribution to contact area analysis of Gecko’s limb and feet
Authors: Tjandra K , Putra R , Sriwijaya R
Published: April 2021

Gecko possesses a distinct feature that enables it to move in lateral and vertical directions due to its adhesive foot structures. In the past few years, the research on Gecko is primarily focused on this adhesive feature. However, Gecko’s hind attachment relies heavily on the available contact area between its foot and its attaching medium. In this paper, physical observation and finite element analysis were performed to identify the load distribution pattern and contact area of Gecko’s hind. Further investigations were also performed to understand the force in each digit of Gecko’s feet. This research will provide readers with a more holistic understanding and complement previous research on Gecko’s attachment system.
Alignment dynamics of single-wall carbon nanotubes under electric field in different surfactant solutions
Authors: Rahman Atiqur , Zubair Ahmed
Published: April 2021

The dynamics of metallic single-wall carbon nanotube (SWCNT) alignment inside various viscous media under electric field is investigated in this simulation work for the manifestation of macroscale aligned SWCNT films. An alternating current (AC) electric field was applied to the liquid solution of several surfactants (DIW, DMF, CHEX, SDS, and DOC) containing SWCNTs. The time required for the SWCNTs to get aligned to the applied AC electric field was simulated for different initial conditions for all the surfactants. An analytical model based on dielectrophoresis induced torque was employed. The model considers the viscosity and conductivity of the surrounding medium. The influence of SWCNT length, SWCNT radius, and frequency of the AC field on the assembly of SWCNTs were studied. Our analysis showed that a longer and narrower SWCNT prompts faster assembly to an aligned SWCNT aggregation. Furthermore, the effect of the concentration of SDS and the effect of electric field strength for DIW surfactant were also investigated. Viscosity plays a significant role in the alignment process. Slower SWCNT alignment is caused by a medium of higher viscosity.
Design of metal hydride reactor with embedded helical coil using optimization methods
Authors: Tiwari Saurabh , Sharma Pratibha
Published: April 2021

Metal hydride offers an efficient and cost-effective method to store hydrogen. In this study, Taguchi method coupled with grey relational analysis was used to optimize the design parameters i.e., diameter of helical tube (dh), major diameter of helical tube (dm), number of turns of helical tube (N) and velocity of heat transfer fluid (
V

f

) for the helical tube heat exchanger embedded inside metal hydride bed to achieve minimum desorption time (td) for 80% desorption and minimum outlet temperature (T0) of heat transfer fluid (HTF). The performance of all experiments in the orthogonal array used for Taguchi and Grey relational analysis was evaluated by 3-D numerical simulations performed in commercial software COMSOL 5.3a. This stepwise methodology is significantly computationally efficient as the number of required simulations reduced by 90% as compared to the traditional parametric study-based methodology. Further, this methodology enables to estimate an optimized level of the parameters by considering all the objective functions (td, T0) simultaneously. Later, the performance of the optimally designed systems was compared with the orthogonal array experiments and it was found out that the optimized system designs have better performance in terms of the objective parameters i.e., td and T0 when compared with the other experiments of orthogonal array. These optimized systems will then be used for refrigeration and cooling applications.
Regularity theorem for totally nonnegative flag varieties
Authors: Galashin Pavel , Karp Steven , Lam Thomas
Published: April 2021

We show that the totally nonnegative part of a partial flag variety

G

/

P

G/P

(in the sense of Lusztig) is a regular CW complex, confirming a conjecture of Williams. In particular, the closure of each positroid cell inside the totally nonnegative Grassmannian is homeomorphic to a ball, confirming a conjecture of Postnikov.
Rate optimality of adaptive finite element methods with respect to overall computational costs
Authors: Gantner Gregor , Haberl Alexander , Praetorius Dirk , Schimanko Stefan
Published: April 2021

We consider adaptive finite element methods for second-order elliptic PDEs, where the arising discrete systems are not solved exactly. For contractive iterative solvers, we formulate an adaptive algorithm which monitors and steers the adaptive mesh-refinement as well as the inexact solution of the arising discrete systems. We prove that the proposed strategy leads to linear convergence with optimal algebraic rates. Unlike prior works, however, we focus on convergence rates with respect to the overall computational costs. In explicit terms, the proposed adaptive strategy thus guarantees quasi-optimal computational time. In particular, our analysis covers linear problems, where the linear systems are solved by an optimally preconditioned CG method as well as nonlinear problems with strongly monotone nonlinearity which are linearized by the so-called Zarantonello iteration.
Dual linear programming bounds for sphere packing via modular forms
Authors: Cohn Henry , Triantafillou Nicholas
Published: April 2021

We obtain new restrictions on the linear programming bound for sphere packing, by optimizing over spaces of modular forms to produce feasible points in the dual linear program. In contrast to the situation in dimensions

8
8

and

24
24

, where the linear programming bound is sharp, we show that it comes nowhere near the best packing densities known in dimensions

12
12

,

16
16

,

20
20

,

28
28

, and

32
32

. More generally, we provide a systematic technique for proving separations of this sort.
Lefschetz fixed point formula: Non-isometry case
Authors: Yi Zelin
Published: April 2021

In this note, we give a geometric proof of the Lefschetz fixed point formula for not-necessarily isometric map. The proof uses a modified Getzler rescaling and the associated rescaled bundle construction (Higson and Yi [Doc. Math. 24 (2019), pp. 1677–1720]).
SISTER CHROMATID EXCHANGE IN XERODERMA PIGMENTOSUM CELLS THAT ARE DEFECTIVE IN DNA EXCISION REPAIR OR POST-REPLICATION REPAIR
Authors: Wolff Sheldon , Bodycote Judy , Thomas G H , Cleaver James E
Published: April 2021

The formation of sister chromatid exchanges has been postulated to depend upon the action of DNA repair enzymes. Our experiments with various human cell lines show that the yield of sister chromatid exchanges is within normal limits in both excision-repair-defective and post-replication-repair-defective cells from the autosomal recessive disease, xeroderma pigmentosum. These results indicate that hypotheses invoking known DNA repair processes to account for the recombination of sister chromatids are inadequate and that the exact enzymatic processes are as yet unknown.
GENETIC DAMAGE AT SPECIFIC GENE LOCI IN DROSOPHILA WITH BETATRON X-RAYS
Authors: Alexander Mary L
Published: April 2021

The mutation rate was determined for mature sperm at eight specific gene loci on the third chromosome of Drosophila melanogaster using the low ion density radiations of 22 Mev betatron X-rays. A dose of 3000 rads of betatron X-rays produced a mutation rate of 4.36 × 10-8 per rad/locus. Among the mutations observed, 66% were recessive lethals and 34% viable when homozygous. Only one of the 24 viable mutations was associated with a chromosome aberration. Among the 47 recessive lethals, no two-break aberrations were detected in 48.9% of the lethals, deletions were associated with 42.2%, inversions with 6.7% and translocations with 2.2%.—When these genetic results are compared to those for 250 KV X-rays, the mutation rate for betatron treatments was slightly lower (.76), the recessive lethal rate among induced mutations was higher, and the chromosome aberrations among lethal mutations were slightly lower than with 250 KV X-rays. Although the two types of irradiations differ by an ion density of approximately ten, the amount and types of inheritable genetic damage induced by the two radiations in mature sperm were not significantly different.
LIPID DEFICIENCIES, LEUKOCYTOSIS, BRITTLE SKIN—A LETHAL SYNDROME CAUSED BY A RECESSIVE MUTATION, EDEMATOUS (OED), IN THE MOUSE
Authors: Schiffman Michael B , Santorineou Maria L , Lewis Susan E , Turchin Howard A , Gluecksohn-Waelsch Salome
Published: April 2021

A new neonatal lethal mutation in the mouse with pleiotropic effects, edematous (oed), arose spontaneously in the phocomelic strain and has been shown to have an autosomal recessive mode of inheritance. The external phenotypic characteristics include a generally bloated appearance, shiny cellophane-like skin, and distal hematomata of the extremities. Internally, no gross or histological abnormalities could be identified, with the exception of a striking leukocytosis. Biochemical analysis revealed a severe disturbance of lipid metabolism. Deficiencies in the VLDL, LDL, and the HDL lipoprotein fractions have been found in the mutant plasma. In addition, all serum lipids are markedly decreased. However, in the mutant liver, only triglycerides are significantly decreased; total liver cholesterol and phospholipid values are within normal limits. The primary biochemical defect as well as the causal relationship between the striking abnormalities of lipid metabolism and those of skin and blood are unknown at this time.
POPULATION GENETICS OF EUPHYDRYAS BUTTERFLIES. I. GENETIC VARIATION AND THE NEUTRALITY HYPOTHESIS
Authors: McKechnie Stephen W , Ehrlich Paul R , White Raymond R
Published: April 2021

Twenty-one populations of the checkerspot butterfly, Euphydryas editha, and ten populations of Euphydryas chalcedona were sampled for genetic variation at eight polymorphic enzyme loci. Both species possessed loci that were highly variable from population to population and loci that were virtually identical across all populations sampled. Our data indicate that the neutrality hypothesis is untenable for the loci studied, and therefore selection is indicated as the major factor responsible for producing these patterns. Thorough ecological work allowed gene flow to be ruled out (in almost all instances) as a factor maintaining similar gene frequencies across populations. The Lewontin-Krakauer test indicated magnitudes of heterogeneity among standardized variances of gene frequencies inconsistent with the neutrality hypothesis. The question of whether or not to correct this statistic for sample size is discussed. Observed equitability of gene frequencies of multiple allelic loci was found to be greater than that predicted under the neutrality hypothesis. Genetic differentiation presisting through two generations was found between the one pair of populations known to exchange significant numbers of individuals per generation. Two matrices of genetic distance between populations, based on the eight loci sampled, were found to be significantly correlated with a matrix of environmental distance, based on measures of fourteen environmental parameters. Correlations between gene frequencies and environmental parameters, results of multiple regression analysis, and results of principle component analysis showed strong patterns of association and of "explained" variation. The correlation analyses suggest which factors might be further investigated as proximate selective agents.
COLD-SENSITIVE MUTANTS OF DROSOPHILA MELANOGASTER DEFECTIVE IN RIBOSOME ASSEMBLY
Authors: Falke Ernest V , Wright Theodore R F
Published: April 2021

Thirteen X-linked, cold-sensitive lethal, female-sterile mutants of Drosophila melanogaster located at eight separate loci were screened for their ability to assemble ribosomes at the restrictive temperature of 17°. Females were labelled with 3H-uridine for either 2 or 20 hours at 17°. A mitochondria-free extract was prepared and analyzed by means of sucrose gradient centrifugation. Four of the mutants, l(1)TW-2 cs, l(1)HM16cs, l(1)HM23cs, and l(1)HM20cs, had a lower ratio of cpm in the 40S subunit to cpm in the 60S subunit (40S:60S ratio) than wild type with a 2-hour label. The same was true of a 20-hour label of l(1)TW-2cs, l(1)HM16cs, and l(1)HM23cs, which are allelic, resulted in a 40S:60S ratio higher than wild type. Four other cs mutants were found to have less drastic effects on ribosome assembly. The ribosomal subunits of mutants l(1)HM16sc and l(1)HM20cs sediment at the same rate as their wild-type counterparts. The same is true for the RNA in their ribosomal particles. Sucrose gradient analysis of ribosomes from cold-sensitive lethal, female-sterile mutants appears to be an effective method for finding mutants that affect ribosome assembly.
GENE FREQUENCY DISTRIBUTIONS AS A TEST OF SELECTIVE NEUTRALITY
Authors: Robertson Alan
Published: April 2021

The analysis of differences between loci in the variance of gene frequency over populations within a species has been suggested as a method of detecting natural selection. It is shown that, in the absence of selection, the expected variation over loci depends strongly on the pattern of relationships between populations. The effect of structure within a species is always to increase the variation and therefore to reduce the power of the method.
ON INVERTED REPEAT SEQUENCES IN CHROMOSOMAL DNA
Authors: Wallace Bruce , Kass Thomas L
Published: April 2021

It is suggested that chromosomal DNA should contain a class of palindromic reverse repeats, comparable in number to that of genes themselves, which are formed as follows: (1) a transcription-termination signal that follows the gene plus (on the complementary strand and located as near to the "anti-gene" as possible); (2) a second termination signal which actively prevents the accidental transcription of the anti-gene. Thus, the adjacent termination-anti-termination region of one strand would complement the anti-termination-termination region of the other.
CLUSTERING OF SPECIFIC CROSSOVERS IN MAIZE MICROSPOROCYTES
Authors: Maguire Marjorie P
Published: April 2021

Analysis of systematic scan data from microsporocyte smear preparations suggests that cells with a crossover in a specific region tend to be geographically clustered to some extent within anthers. Crossover classes observed include single crossovers within a heterozygous inversion, three-strand double crossovers within and proximal to the inversion, and four-strand double crossovers within the inversion. Evidence for clustering within scans of cells of the first two classes is reported, but results are inconclusive for the third class. No evidence for within-scan correlation of frequencies of any two of the crossover classes was found. It is inferred that a large part of the variability in crossover frequency observed is probably due to factors which alter crossover interference. Implications related to the frequency and distribution of crossover sites are discussed.
VARIATIONS IN THE NUMBER OF THE Y CHROMOSOMAL rRNA GENES IN DROSOPHILA HYDEI
Authors: Kunz W
Published: April 2021

The number of rRNA cistrons is measured by filter saturation hybridization in different stocks of D. hydei, where the wild-type X chromosome has one nucleolus organizer (NO) and the wild-type Y has two separated NO's. (see PDF) females having no X chromosomal NO show an rDNA content exceeding that of a Y chromosome. An even greater increase in the rRNA cistron number is measured in two translocation stocks where the (see PDF) is combined with one half of a Y and, therefore, each stock contains only one of the two Y chromosomal NO's. But when the same Y fragments are brought together with a wild-type X chromosome they lose about one-half of their rRNA cistrons within one generation. Males with two complementary Y fragments but having no X chromosomal NO show a considerably higher rDNA content than the (see PDF) females, although both are equal in respect of their NO number. Consideration is given to related phenomena in Drosophila melanogaster.