bluuebunny/crossref_metadata_2025 huggingface dataset:
Techno Economic Analysis of Biomass to Methanol Plant Based on Gasification of Palm Empty Fruit Bunch
Authors: Heryadi Rudy , Muhammad Nur Syukri
Published: January 2021

Biomass from palm empty fruit bunch (EFB) is considered as potential renewable energy sources to be developed in Indonesia. Palm EFB can be efficiently converted into valuable and useful methanol products through gasification. Research about methanol synthesis from various biomass has been done. However, Little research about methanol production based on palm empty fruit bunch gasification has been found, and no research yet on technoeconomic analysis of methanol plant construction based on palm empty fruit bunch gasification. The purpose of this research is to find early-stage feasibility of small-scale methanol plant model based on gasification of palm EFB. Method methanol plant design, investment cost estimation, operating cost estimation, and calculation to estimate profitability in terms of economic feasibility parameters. Economic analysis calculated that the total investment to build a methanol plant in this study was USD 87 508 479 with manufacturing cost per annum USD 6 127 014. Net Present Value (NPV) calculated was USD -51 721 064 and IRR at 1.1 %. Based on NPV and Internal Rate of Return (IRR) value, the construction of methanol plant is not feasible. Feasibility predicted to be obtained when the capacity of the plant increased fivefold.
Modified Off–Season Technology to the Flowering Time and Fruit Yield of Arumanis Mango (Mangifera indica L.)
Authors: Husen Syarif , Ishartati Erny , Muhidin Muhidin , Dwi Siskawardani Devi , Rizky Anjar , Syaifudin Akhmad , Onthong Jumpen
Published: January 2021

The purpose of this study was to observe the technology of mango fruit production at off-season used growth regulators. The research was conducted with three treatments namely: i) Paclobutrazol dosage (control, 5 mL L–1 per tree, 10 mL L–1 per tree and 15 L–1 per tree). ii) Ethephon dosages (0 mL L-1 per tree, 400 mL L–1 per tree, 600 mL L–1 per tree and 800 mL L–1 per tree) that applied 1 mo after paclobutrazol addition. iii) Paclobutrazol (P) and organic fertilizer (F) application in combination as follows: (control, 5 mL + 10 kg, 10 mL + 15 kg, 15 mL + 20 kg) Randomized Completely Block Designed (RCBD) with five replications was used. The results indicated that i) Paclobutrazol application accelerated the flowering age, shortens the panicle length, and increased fruit yield of the tree. ii) Giving Ethephon accelerated the flowering period, enhanced both the panicles number and yields. The treatment of ethephones 600 mL L–1 produced the highest fruit weight, 182.60 kg, respectively iii) The Paclobutrazol and organic fertilizer application indicated significantly (p < 0.05) to the panicles number and the fruit weight yield is higher than the control.
Study of Agronomic Characteristics of Robusta Coffee at Coffee Plantations in Temanggung, Indonesia
Authors: Theresia Maria Astuti Yohana , Rahayu Enny , Nugraha Budi Santosa Tri , Pratama Putra Dian , Solifudin Agus , Wijayanti Yureana , Fittkow Marcus
Published: January 2021

This research aims to study the condition of the land, its relation to the character of the coffee plant in the farmers’ coffee plantation in the Sucen Village, Gemawang District, Temanggung, Indonesia. The research was carried out at a community coffee plantation in Sucen Village, Temanggung, Central Java, Indonesia. The research was conducted using descriptive and inferential statistics. Observation of performance with 30 samples was conducted by random sampling technique in three clones. Land suitability analysis was carried out at three observation points. The result showed that the vegetative character of BP 409 clones is better than BP 288 and BP 358. However, the highest production was obtained at BP 288. Land suitability in Sucen Village remains in the inappropriate criteria, which can be improved through land conservation and balanced fertilization.
Nonlinear dynamics of magnetization evolution in orthogonal spin torque devices: Phases and classification
Authors: Hui Yuan , Yang Zheng , Yu Hao
Published: January 2021

The magnetization evolution of the free layer in an orthogonal spin torque device is studied based on a macrospin model. The trajectory of the magnetization vector under various conditions has shown rich nonlinear properties. The phase diagram is obtained in the parameter spaces of current density and the polarization distribution (the ratio of polarization of in-plane to out-of-plane layers), where two critical currents and three phases are found. These dynamic phases can be classified according to their nonlinear behaviors, which are different in terms of limit cycles and limit points. The classification is meaningful to design ultra-fast spin torque devices under different dynamic conditions toward various applications, such as in memory and oscillators.
Experiments on atomization and spray characteristics of an effervescent strut injector
Authors: Chakraborty Mayukhmali , Vaidyanathan Aravind , Desikan S. L. N.
Published: January 2021

The atomization and the spray characteristics from an effervescent/aerated strut injector were studied experimentally using water as the liquid and nitrogen gas as the secondary fluid. The spray flow features were obtained through various experimental tools such as instantaneous Mie scattering technique, phase Doppler particle analyzer, and time-resolved shadowgraph images for different Weber numbers, momentum flux ratios, and gas to liquid ratios. A proper orthogonal decomposition method was used for an in-depth analysis of the spray structures. The instantaneous Mie scattering images showed the formation of the liquid clusters and the dominant two-phase flow interaction with increasing momentum flux and gas to liquid ratios in addition to the increased spray spread area. The statistical analysis of the Mie images revealed high fluctuating locations in the spray. It was observed that by increasing the momentum flux or gas to liquid ratios, the droplet diameter rapidly decreases due to the flow transition to the annular flow regime. Beyond a certain limit of momentum flux or gas to liquid ratios, no significant change in the diameter was observed. Furthermore, the spatio-temporal fluid dynamic features and the two-phase flow transition inside the spray region were brought out through the proper orthogonal decomposition. The power spectral density revealed the ligament breakup and the droplet formation below ≤500 Hz. Regardless of the momentum flux and gas to liquid ratios, a peak was observed between 2500 Hz and 3000 Hz due to the flow transition where the liquid fragment cluster formation and the flapping were found to be almost constant.
Electrochemical reaction in memristor devices in a set state
Authors: Guo Hongxuan , Liu Xuanxuan , Gao Xu , Yin Kuibo , Yin Jiang , Xia Yidong , Liu Zhiguo , Sun Litao
Published: January 2021

The growth of Ag-nanofilaments in the solid electrolyte films of memristors based on Ag30S2P14O42 is investigated. After the formation of the Ag-nanofilaments in the solid electrolyte, the memory cells are switched to the high conductive state. With a positive voltage applied on the Ag electrode of the cells, the Ag-nanofilaments gradually become thicker due to the reduction and diffusion of Ag+ cations in the solid electrolyte. The relationship between the thickening rate of the Ag-nanofilaments and the concentration of the Ag+ cations surrounding them is analyzed, and the results show that the thickening of the Ag-nanofilaments is determined by the reduction and diffusion of Ag+ cations in the solid electrolyte.
Ab initio investigation of the physical properties of Tl based chloroperovskites TlXCl3 (X = Ca and Cd)
Authors: Zaman Shams U. , Rahman Nasir , Arif Muhammad , Saqib Muhammad , Husain Mudasser , Bonyah Ebenezer , Shah Zahir , Zulfiqar Syed , Khan Aurangzeb
Published: January 2021

This theoretical study is performed to investigate structural, elastic, and electronic properties as well as optical response to incident photons of thallium based chloroperovskite TlXCl3 (X = Ca and Cd) compounds. Both compounds have a stable crystal structure with optimized lattice constants ranging from 5.40 Å to 5.26 Å. The elastic parameters such as elastic constants, bulk modulus, anisotropy factor, Poisson’s ratio, and Pugh’s ratio are evaluated. Poisson’s ratio describes the ductile nature of these materials. The band structure and elemental contribution to different states for all the compounds are analyzed. Materials have a wide bandgap with indirect band nature. Optical parameters such as dielectric function, refractive index, extinction coefficient, reflectivity, absorption coefficient, and optical conductivity are studied in the energy range of 0 eV–30 eV. The comparative results suggest that thallium based compounds are important to be used as scintillating materials and stimulate further experimental investigations of such compounds.
Study on structure and magnetic properties of Y2(Fe, Co)14B melt-spun ribbons
Authors: Zhang Xiongzuo , Han Jingzhi , Liu Pengfei , Liu Shunquan , Wang Changsheng , Li Xin , Zhang Xiaodong , Xu Qing , Yang Yingchang , Yang Jinbo
Published: January 2021

Y2Fe14-xCoxB (X=8.5,9,9.5,10,10.5) melt-spun ribbons were prepared by modifying alloy composition and optimizing melt-spinning technique. It is found that Y2Fe14-xCoxB ribbons with a saturation magnetization of ∼120 emu/g and a coercivity less than 1 Oe can be prepared at x = 9.5 and a wheel rate of 55 m/s. TEM investigations exhibit that the ribbons are composed of Y2(Fe,Co)14B nanocrystals with a mean grain size of ∼5 nm and an amorphous matrix. The ribbons were subsequently pulverized by high energy ball milling technology, and the flakey particles with a length of ∼30 um and a thickness of ∼250 nm were obtained. Finally, the high-frequency electromagnetic properties of the composite magnetic ring formed by mixing flakey particles and paraffin wax in the mass ratio of 2:1 were measured, and the reflection loss (RL) value of the composite is less than -20 dB near 1-2 GHz, which indicates that the material is beneficial to the absorption of electromagnetic wave in 1-2 GHz band.
A happy family: systematic revision of the endemic Theridion spiders (Araneae, Theridiidae) of the Hawaiian Islands
Authors: Bellvert Adrià , Gillespie Rosemary G. , Arnedo Miquel A.
Published: January 2021

Since the description in 1900 of the iconic Happy Face spider, Theridion grallator, Simon, along with nine relatives, the Theridion fauna of the Hawaiian Islands has remained unstudied. Here, we present a systematic revision of the Hawaiian Theridion, which includes the examination of abundant material collected during the last 50 years, with scanning of the genitalia of several species using SEM techniques, and a cladistic analysis based on 22 morphological characters, to provide a first hypothesis of the phylogenetic structure of the group. We describe eight new species, namely T. ariel, sp. nov., T. caliban, sp. nov., T. ceres, sp. nov., T. ferdinand, sp. nov., T. juno, sp. nov., T. miranda, sp. nov., T. prospero, sp. nov. and T. sycorax, sp. nov. Additionally, we provide new diagnoses for former species and illustrate and describe for the first time the male of T. kauaiense Simon, 1900 and the female of T. praetextum Simon, 1900. We further propose that T. campestratum Simon, 1900 is a junior synonym of T. melinum Simon, 1900 and T. praetextum concolor Simon, 1900 is a junior synonym of T. praetextum. Finally, we provide updated information on the distribution of the species. Most species are easily diagnosed based on the male and female genitalia, but we also reveal the existence of somatic characters that differ among species, such as the body size and the shape and size of the chelicerae, which may have played a role in the diversification and coexistence of some of the species. The preferred cladogram from the cladistic analysis, although compatible with a progression rule, also suggests a complex pattern of multiple back and forward colonisations, albeit most of the clades are poorly supported.
Empowering the Indigenous voice in a graphical representation of Aotearoa’s biocultural heritage (flora and fauna)
Authors: Aitken J. , Shadbolt M. , Doherty J. , Mark-Shadbolt M. , Marzano M. , Ataria J.
Published: January 2021

Aotearoa’s (New Zealand’s) biological heritage is in decline due to threats such as climate change and habitat destruction. Aotearoa’s biological heritage and the wider environment are critical to the Māori world view and culture and Māori have long advocated for greater engagement in efforts to reverse this decline. One negative outcome of localised declines in biological heritage is a concomitant loss of local Māori language (dialectical) terms. Compounding this is the growing use of standardised Māori terms that can displace local dialectical terms. This also runs the risk of losing the associated mātauranga (knowledge) that is inherent in the meaning of these local terms for their unique flora and fauna. Retaining this biocultural knowledge is considered important and could play a role in conservation efforts. This collaborative research addressed the concerns articulated by a Māori biological heritage expert about the loss of their own unique local Māori terms for flora and fauna. The research explored ways to retain and empower local indigenous biocultural terms via the creation of a static visual educational resource for Tūhoe–Tuawhenua youth displaying the forest vegetation of their rohe (area that defines a tribe’s traditional mandate or authority). The plants in the final resource are identified by their local Māori term and their corresponding scientific name. Depicting ecological accuracy in the artwork was a specific requirement of the kaumātua and created some unique outcomes in how the artwork formed. The approaches employed in this research and an analysis of the results and wider implementation are discussed.
Theoretical plurality, the extended evolutionary synthesis, and archaeology
Authors: Prentiss Anna Marie
Published: January 2021

The study of cultural evolution now includes multiple theoretical frameworks. Despite common influence from Darwinian evolutionary theory, there is considerable diversity. Thus, we recognize those most influenced by the tenets of the Modern Synthesis (evolutionary archaeology, cultural transmission theory, and human behavioral ecology) and those most aligned more closely with concepts emerging in the Extended Evolutionary Synthesis (cultural macroevolution and evolutionary cognitive archaeology). There has been substantial debate between adherents of these schools of thought as to their appropriateness and priority for addressing the fundamentals of cultural evolution. I argue that theoretical diversity is necessary to address research questions arising from a complex archaeological record. Concepts associated with the Extended Evolutionary Synthesis may offer unique insights into the cultural evolutionary process.
Translating sexuality in the context of Anglo-American censorship
Authors: Qi Lintao
Published: January 2021

This article presents a descriptive study of the English translations of the classic Chinese novelJin Ping Meiin the context of the Anglo-American literary censorship of obscenity in the twentieth century. By scrutinizing the strategies employed in the English translations ofJin Ping Mei, this article uncovers the dynamic interactions between literary translation activities and the evolving socio-historical contexts in the target culture. The resurrection of the archaic source text, particularly its erotic component, in the Anglophone world in the twentieth century was based on the (re)discovery of its value in the contemporary target context. In the case ofJin Ping Mei, equivalence at the linguistic and textual levels was simply not a concern of the translators and publishers, who had to decide how they would deal with the social reality of literary censorship, by submissively conforming to its demands, or by creatively confronting them.
Extended Lipkin–Meshkov–Glick Hamiltonian
Authors: Romano R , Roca-Maza X , Colò G , Shen(申时行) Shihang
Published: January 2021

The Lipkin–Meshkov–Glick (LMG) model was devised to test the validity of different approximate formalisms to treat many-particle systems. The model was constructed to be exactly solvable and yet non-trivial, in order to capture some of the main features of real physical systems. In the present contribution, we explicitly review the fact that different many-body approximations commonly used in different fields in physics clearly fail to describe the exact LMG solution. With similar assumptions as those adopted for the LMG model, we propose a new Hamiltonian based on a general two-body interaction. The new model (extended LMG) is not only more general than the original LMG model and, therefore, has a potentially larger spectrum of applicability, but also the physics behind its exact solution can be much better captured by common many-body approximations. At the basis of this improvement lies a new term in the Hamiltonian that depends on the number of constituents and polarizes the system; the associated symmetry breaking is discussed, together with some implications for the study of more realistic systems.
Anisotropic lattice thermal conductivity in topological semimetal ZrGeX (X
= S, Se, Te): a first-principles study
Authors: Zhou Yu , Liang A-Kun , Zeng Zhao-Yi , Chen Xiang-Rong , Geng Hua-Yun
Published: January 2021

Topological semimetals have attracted significant attentions owing to their potential applications in numerous fields such as low-power electron devices and quantum computation, which are closely related to their thermal transport properties. In this work, the phonon transport properties of topological Dirac nodal-line semimetals ZrGeX (X = S, Se, Te) with the PbClF-type structures are systematically studied using the first-principles calculations combined with the Boltzmann transport theory. The obtained lattice thermal conductivities show an obvious anisotropy, which is caused by the layer structures of ZrGeX (X = S, Se, Te). The room-temperature lattice conductivity of ZrGeTe along c direction is found to be as low as 0.24 W m−1 K−1, indicating that it could be of great significance in the fields of thermal coating materials and solar cell absorber. In addition, we extract each phonon branch from group velocities, phonon scattering rates, Grüneisen parameters, and phase space volumes to investigate the mechanism underlying the low thermal conductivity. It is concluded that the difference of thermal conductivities of three materials may be caused by the number of scattering channels and the effect of anharmonic. Furthermore, the phonon mean free path along a direction is relatively longer. Nanostructures or polycrystalline structures may be effective to reduce the thermal conductivity and improve the thermoelectric properties.
Corrigendum: Two blocks connected by a string with variable tension: a dynamic case (2020 Phys. Educ.
55
055022)
Authors: Herrera-Suárez H J , Machado-Higuera M , Muñoz J H
Published: January 2021

In this corrigendum we correct some typing errors. The corrections do not have any impact on the conclusions of the paper.
Observational characteristics of SiO masers around VX Sgr
Authors: Su Jiang-Bo , Shen Zhi-Qiang , Chen Xi , Liu Jing , Wang Yan , Zhao Yi-Bin
Published: January 2021

SiO maser VLBA observations toward VX Sgr are performed at five epochs, and lots of maser spots are obtained. We make a statistical analysis on these spots. It is shown that the apparent sizes and the fluxes of maser spots decrease with increasing the distance from the central star. In addition, the similarity between the v = 1,2 (J = 1−0) spectrums increases with epochs, consistent with the full width at half maximum (FWHM), while the total fluxes increase. The results may be related to the changeable pumping mechanisms.
Potential responses and resilience of Late Chalcolithic and Early Bronze Age societies to mid-to Late Holocene climate change on the southern Iberian Peninsula
Authors: Weinelt Mara , Kneisel Jutta , Schirrmacher Julien , Hinz Martin , Ribeiro Artur
Published: January 2021

In this investigation, we use a socio-environmental multi-proxy approach to empirically test hypotheses of recurrent resilience cycles and the role of climate forcing in shaping such cycles on the Iberian Peninsula during mid-Holocene times. Our approach combines time series reconstructions of societal and environmental variables from the southern Iberian Peninsula across a 3000 yr time interval (6000–3000 cal yr BP), covering major societal and climate reorganisation. Our approach is based on regional compilations of climate variables from diverse terrestrial archives and integrates new marine climate records from the Western Mediterranean. Archaeological variables include changes in material culture, settlement reconstructions and estimates of human activities. In particular, both detailed chronologies of human activities evolving from the Late Neolithic to the Bronze Age and mid- to Late Holocene climate change across the mid-Holocene are compared, aiming to assess potential human responses and coping processes associated with abrupt mid-Holocene climate changes.
Assessing the future of global energy-for-water
Authors: Kyle Page , Hejazi Mohamad , Kim Son , Patel Pralit , Graham Neal , Liu Yaling
Published: January 2021

This study incorporates the energy demands of water abstraction, treatment, distribution, and post-use wastewater treatment into the Global Change Analysis Model, an integrated human-Earth systems model, and analyzes a range of scenarios that estimate the future evolution of this demand of energy. The study complements research on historical and future water-for-energy, and builds on bottom-up estimates of historical energy-for-water (EFW), by integrating EFW into nation-level energy statistics, where EFW is normally categorized with other energy use in the commercial and public services, industrial, agricultural, and/or electric power sectors. This development allows more resolved projections of future energy demands in general, and in this study, allows for assessment of the energy implications of improvements in water access and water quality that are consistent with the sustainable development goals (SDGs). In our baseline scenario, EFW increases by 2.6 times from 2015 to 2050, and in the SDG scenario with enhanced water access, standards for treatment of wastewater, and irrigation, the consequent EFW demands quadruple from 2015 to 2050. The study highlights the value of integrated, multi-sector analysis in quantifying the future impacts of the SDGs and other aspirational targets.
Trigonometric

∨

-systems and solutions of WDVV equations
*
Authors: Alkadhem Maali , Feigin Misha
Published: January 2021

We consider a class of trigonometric solutions of Witten–Dijkgraaf–Verlinde–Verlinde equations determined by collections of vectors with multiplicities. We show that such solutions can be restricted to special subspaces to produce new solutions of the same type. We find new solutions given by restrictions of root systems, as well as examples which are not of this form. Further, we consider a closely related notion of a trigonometric ∨-system, and we show that its subsystems are also trigonometric ∨-systems. Finally, while reviewing the root system case we determine a version of (generalised) Coxeter number for the exterior square of the reflection representation of a Weyl group.
Generalized Bäcklund transformations for affine Toda hierarchies
Authors: de Carvalho Ferreira J M , Gomes J F , Lobo G V , Zimerman A H
Published: January 2021

The construction of generalized Bäcklund transformation for the A

n
affine Toda hierarchy is proposed in terms of gauge transformation acting on the zero curvature representation. Such construction is based upon the graded structure of the underlying affine algebra which induces a classification of generalized Bäcklund transformations. Moreover, explicit examples for sl(3) and sl(4) lead to uncover interesting composition properties of various types of Bäcklund transformations. The universality character of the gauge-Bäcklund transformation method is extended to all equations of the hierarchy. Such interesting property provides a systematic framework to construct Bäcklund transformations to higher flow equations. Explicit example for the simplest higher flow of the sl(3) hierarchy is presented.
Weed–Insect Interactions in Annual Cropping Systems
Authors: Barbercheck Mary E , Wallace John
Published: January 2021

Agricultural production is increasingly viewed as more than a source of food, feed, fiber and fuel, but also as a system of interdependent biotic and abiotic components that interact to produce ecosystem services and disservices. Weeds and insects are commonly viewed as non-desirable components of agroecosystems that should be managed. However, weeds can also provide benefits to cropping systems, such as providing resources and habitat to pollinators and other beneficial arthropods. This review on weed–insect interactions in annual cropping systems focuses on functional interactions within the context of regulating and supporting ecosystem services and disservices. Regulating services are those that act as regulators of the environment, such as weed–insect interactions that contribute to the regulating services of pollination and biological control, but also contribute to the disservices of crop and cover crop seed predation, and maintenance of insect pests and insect-transmitted phytopathogens. Supporting services include habitat and biodiversity that are necessary for the production and maintenance of the other types of ecosystem services. Here we review the impacts of weed–insect interactions as a component of biodiversity. We conclude by identifying some knowledge gaps that hinder our understanding of trade-offs when seeking to improve net positive ecosystem services in annual cropping systems.
Decoding the Content of Auditory Sensory Memory Across Species
Authors: Cappotto Drew , Auksztulewicz Ryszard , Kang HiJee , Poeppel David , Melloni Lucia , Schnupp Jan
Published: January 2021

In contrast to classical views of working memory (WM) maintenance, recent research investigating activity-silent neural states has demonstrated that persistent neural activity in sensory cortices is not necessary for active maintenance of information in WM. Previous studies in humans have measured putative memory representations indirectly, by decoding memory contents from neural activity evoked by a neutral impulse stimulus. However, it is unclear whether memory contents can also be decoded in different species and attentional conditions. Here, we employ a cross-species approach to test whether auditory memory contents can be decoded from electrophysiological signals recorded in different species. Awake human volunteers (N = 21) were exposed to auditory pure tone and noise burst stimuli during an auditory sensory memory task using electroencephalography. In a closely matching paradigm, anesthetized female rats (N = 5) were exposed to comparable stimuli while neural activity was recorded using electrocorticography from the auditory cortex. In both species, the acoustic frequency could be decoded from neural activity evoked by pure tones as well as neutral frozen noise burst stimuli. This finding demonstrates that memory contents can be decoded in different species and different states using homologous methods, suggesting that the mechanisms of sensory memory encoding are evolutionarily conserved across species.
Popularity and centrality in Spotify networks: critical transitions in eigenvector centrality
Authors: South Tobin , Roughan Matthew , Mitchell Lewis
Published: January 2021

The modern age of digital music access has increased the availability of data about music consumption and creation, facilitating the large-scale analysis of the complex networks that connect musical works and artists. Data about user streaming behaviour and the musical collaboration networks are particularly important with new data-driven recommendation systems. Here, we present a new collaboration network of artists from the online music streaming service Spotify and demonstrate a critical change in the eigenvector centrality of artists, as low popularity artists are removed. This critical change in centrality, from a central core of classical artists to a core of rap artists, demonstrates deeper structural properties of the network. Both the popularity and degree of collaborators play an important role in the centrality of these groups. Rap artists have dense collaborations with other popular artists whereas classical artists are diversely connected to a large number of low and medium popularity artists throughout the graph through renditions and compilations. A Social Group Centrality model is presented to simulate this critical transition behaviour, and switching between dominant eigenvectors is observed. By contrasting a group of high-degree diversely connected community leaders to a group of celebrities which only connect to high popularity nodes, this model presents a novel investigation into the effect of popularity bias on how centrality and importance are measured.
Effects of Plant Stress on Aphid–Parasitoid Interactions: Drought Improves Aphid Suppression
Authors: Kansman Jessica T , Ward Mason , LaFond Harper , Finke Deborah L
Published: January 2021

Drought events have the potential to mediate tri-trophic interactions. Changes in plant quality influence herbivore performance, which affects prey availability and quality for natural enemies. Parasitoid wasps are particularly vulnerable to these changes since their development is inextricably linked to that of their prey. However, we know little about the indirect effects of plant water limitation on parasitoid performance, especially the consequences of mild water limitation. This study investigated the ability of a parasitoid wasp (Aphidius colemani Viereck (Hymenoptera: Braconidae)) to suppress aphid (Rhopalosiphum padi L. (Hemiptera: Aphididae)) populations on well-watered, mildly stressed, or highly stressed wheat (Triticum aestivum L. (Poales: Poaceae)). We then investigated the role that aphid body size and behavioral interactions might play in wasp acceptance of aphid hosts. We found improved aphid suppression under mild and high-water limitation, but the underlying mechanisms were different. Mild-stress appeared to maximize parasitoid performance, as indicated by the highest mummy production. Aphids were larger when feeding on mildly stressed plants than on any other treatment, which suggests improved aphid quality for parasitoids. Improved aphid suppression under high-stress may have been driven by enhanced nonconsumptive effects. Despite improved aphid suppression, mummy formation was lowest on highly stressed plants. High-stress conditions have been shown to negatively affect aphid performance, so improved aphid suppression may be driven by poor aphid performance exacerbating the cost of interactions with parasitoids, such as stinging. No differences were observed in parasitoid foraging behaviors such as antennation or stinging across any treatments. This study highlights the importance of plant water stress intensity in affecting outcomes of parasitoid–host interactions.
ASSOCIATIONS BETWEEN ALLOZYME GENOTYPES AND QUANTITATIVE TRAITS IN DOUGLAS-FIR [PSEUDOTSUGA MENZIESII (MIRB.) FRANCO]
Authors: El-Kassaby Yousry A
Published: January 2021

Effects of maternal genotypes for eight enzyme loci on seven quantitative traits in 41 half-sib families were determined. Heritability estimates for the quantitative traits were highly significant and ranged from 0.57 to 0.86. Only six of 112 comparisons (56 comparisons for each of the genotypes and 56 for homozygous versus heterozygous contrasts) were statistically significant (P < 0.05). None of these significant comparisons could be associated with either a particular allele or a particular genotype. No heterotic effects were observed when the homozygous genotypes were compared with the heterozygous ones. Because the quantitative traits are highly correlated, a discriminant function analysis was performed to obtain the two most important canonical variates that accounted for 75% of the variance in the quantitative traits. There were no significant associations among enzyme loci and the two canonical variates. I conclude that, in this study, enzyme genotypic differences do not influence the quantitative traits to a major extent.
CYTOPLASMIC MALE STERILITY IN BARLEY. XI. THE msm2 CYTOPLASM
Authors: Ahokas H
Published: January 2021

A new cytoplasmic male sterility in barley (Hordeum vulgare s.l.) is described and designated as msm2. The cytoplasm was derived from a selection of the wild progenitor of barley (H. vulgare ssp. spontaneum). This selection, 79BS14-3, originates from the Southern Coastal Plain of Israel. The selection 79BS14-3 has a normal spike fertility in Finland. When 79BS14-3 was crossed by cv. Adorra, the F1 displayed partial male fertility and progeny of recurrent backcrosses with cv. Adorra were completely male sterile. Evidently 79BS14-3 is a carrier of a recessive or semidominant restorer gene of fertility. The dominant restorer gene Rfm1a for another cytoplasmic male sterility, msm1, is also effective in msm2 cytoplasm. The different partial fertility restoration properties of msm2 and msm1 cause these cytoplasms to be regarded as being distinct. Seventy spontaneum accessions from Israel have been studied for their capacity to produce F1 restoration of male fertility both in msm1 and in msm2 cytoplasms with a cv. Adorra-like seed parent (nuclear gene) background. The msm2 cytoplasm shows partial restoration more commonly than msm1 in these F1 combinations. The mean restoration percentage per accession for msm2 is 28, and for msm1 4. Most of the F1 seed set differences of the two cytoplasms are statistically significant. When estimated with partially restored F1 combinations, msm2 cytoplasm appeared to be about 50 times more sensitive to the male fertility-promoting genes present in the spontaneum accessions. The spontaneum sample from Central and Western Negev, which has been found to be devoid of restoration ability in msm1 cytoplasm, had only low partial restoration ability in msm2 (mean 0.3%). The female fertility of msm2 appears normal. The new msm2 cytoplasm could be useful in producing hybrid barley.
MOLECULAR FATE OF HETEROLOGOUS BACTERIAL DNA IN COMPETENT BACILLUS SUBTILIS. II. UNSTABLE ASSOCIATION OF HETEROLOGOUS DNA WITH THE RECIPIENT CHROMOSOME
Authors: te Riele Hein P J , Venema Gerard
Published: January 2021

In CsCl density gradients of lysates from competent Bacillus subtilis cells, which had been exposed to heterologous bacterial DNA, very little donor-recipient complex (DRC) formation could be detected. The present study demonstrates that photocrosslinking of such lysates by irradiation with long-wave UV light in the presence of 4,5′,8-trimethylpsoralen results in a dramatic increase in the amount of heterologous DRC. This phenomenon may be interpreted as the stabilization of a pre-existing weak association between entered heterologous donor DNA and one recipient strand in unpaired regions of the chromosome. When a recombination-deficient mutant is used, the amount of stabilizable heterologous DRC is reduced to the same extent as the specific transforming activity of homologous DNA. Although the amount of stabilizable complex is related to the degree of homology between donor and recipient DNA, this relation is not a quantitative one. Probably the association is caused by very short regions of base pairing between the donor and recipient moieties in the complex. Heating of a lysate at 70° prior to photocrosslinking prevents stabilization, apparently because the regions of base pairing are rapidly melted out. The results described in this paper can be best interpreted as the fixation of a process in which entered donor DNA in competent cells tries to find homologous stretches in the recipient chromosome.
THE GENETICS OF A SMALL CHROMOSOME REGION OF DROSOPHILA MELANOGASTER CONTAINING THE STRUCTURAL GENE FOR ALCOHOL DEHYDROGENASE. IV: SCUTOID, AN ANTIMORPHIC MUTATION
Authors: Ashburner M , Tsubota S , Woodruff R C
Published: January 2021

Exchange mapping locates the dominant mutation Scutoid to the right of Adh on chromosome arm 2L of D. melanogaster. However, deletion mapping indicates that Sco is to the left of Adh. The phenotype of Sco is sensitive to mutation, or deletion, of noc  + and of three genes, el, l(2)br22, and l(2)br29 mapping immediately distal to noc. The four contiguous loci, el, l(2)br22, l(2)br29 and noc, although separable by deletion end points, interact, because certain (or all) alleles of these four loci show partial failure of complementation, or even negative complementation. The simplest hypothesis is that Sco is a small reciprocal transposition, the genes noc, osp, and Adh exchanging places with three genes normally mapping proximal to them: l(2)br34, l(2)br35 and rd. The Sco phenotype is thought to result from a position effect at the newly created noc/l(2)br28 junction.
HETEROKARYON ANALYSIS OF THE GENETIC CONTROL OF PIGMENT SYNTHESIS IN CHICK EMBRYO MELANOCYTES
Authors: Wilkins L M , Brumbaugh J A , Moore J W
Published: January 2021

The genetic control of pigmentation was analyzed using five unlinked mutants, namely, c, pk, Bl, ey and I. Each mutant blocks or reduces pigmentation. Chick melanocyte cultures of each mutant type were fused to produce all ten possible pair combinations of nondividing heterokaryons. Heterokaryons were identified autoradiographically. (One partner in each pair was labeled with 3H-thymidine.) Crosses produced comparable pairs of double heterozygotes that were analyzed in vivo and in vitro. Heterokaryon pairs were compared to their corresponding double heterozygotes.—Some combinations showed complementation and produced wild-type pigment. Others showed noncomplementation having little or no pigment. Double heterozygotes complemented each other except in the cases involving the dominant mutant, I. Four heterokaryon pairs gave different results from their corresponding double heterozygotes. The pk-Bl and pk-ey combinations failed to complement as heterokaryons but did complement as double heterozygotes. On the other hand, the I-c and I-Bl combinations complemented as heterokaryons but not as double heterozygotes. Based on these differences it is hypothesized that the pk and I loci are nuclearly restricted regulatory elements. Examples in the literature from other systems are cited to support such a hypothesis.
PEP4 GENE FUNCTION IS REQUIRED FOR EXPRESSION OF SEVERAL VACUOLAR HYDROLASES IN SACCHAROMYCES CEREVISIAE
Authors: Jones Elizabeth W , Zubenko George S , Parker Roy R
Published: January 2021

The pep4-3 mutation results in a 90-95% reduction in the levels of five vacuolar hydrolases in yeast, including proteinases A and B, carboxypeptidase Y, RNase(s) and the repressible alkaline phosphatase. The mutation is without effect on two secreted glycoproteins, on an enzyme of the vacuolar membrane, and on a proteinase located outside of the vacuole. Mutations at the PEP4 locus exhibit a dosage effect on the levels of some, but not all, of the enzymes whose expression requires the function of the gene.
A GENETIC MAP OF DICTYOSTELIUM DISCOIDEUM BASED ON MITOTIC RECOMBINATION
Authors: Welker Dennis L , Williams Keith L
Published: January 2021

A genetic map of the cellular slime mold Dictyostelium discoideum is presented in which 42 loci are ordered on five of the seven linkage groups. Although most of the loci were ordered using standing mitotic crossing-over techniques in which recessive selective markers were employed, use was also made of unselected recombined haploid strains. Consistent with cytological studies in which the chromosomes appear to be acrocentric, only a single arm has been found for each of the five linkage groups studied. The mating-type locus, matA, has been located in the tsgE-sprA interval on linkage group I on the basis of studies on diploids formed between strains of opposite mating type that have escaped from vegetative incompatibility.
VITAL GENES THAT FLANK SEX-LETHAL, AN X-LINKED SEX-DETERMINING GENE OF DROSOPHILA MELANOGASTER
Authors: Nicklas Janice A , Cline Thomas W
Published: January 2021

The X-chromosome:autosome balance in D. melanogaster appears to control both sex determination and dosage compensation through effects on a maternally influenced sex-linked gene called Sex-lethal (Sxl; 1-19.2). To facilitate molecular and genetic analysis of Sxl, we attempted to determine the locations of all ethyl methanesulfonate (EMS)-mutable genes vital to both sexes in the region between 6E1 and 7B1. This area includes approximately 1 cM of the genetic map on each side of Sxl and was reported by C. B. Bridges to contain 26 salivary gland polytene chromosome bands. The region appears rather sparsely populated with genes vital to both sexes, since the 122 recessive lethal mutations we recovered fell into only nine complementation groups. From one to 38 alleles of each gene were recovered. There was a preponderance of embryonic lethals in this area, although the lethal periods of loss-of-function mutations included larval, pupal and adult stages as well. Since the screen required that mutations be recessive and lethal to males, our failure to recover new Sxl alleles was the result expected for a gene with a female-specific function. An attempt was made to identify recessive male-specific lethals in this region, but none were found. Precise map positions were determined for eight of the nine vital genes. An interesting feature of the map is the location of Sxl in the middle of a 0.6- to 0.7-cM interval that appears to be devoid of genes vital to both sexes. The genetic location was determined of breakpoints near Sxl for all available chromosome rearrangements. Sxl is most likely located just to the left of band 7A1. We determined the relationship of our EMS-induced mutations in these nine genes to alleles induced by others. From this we conclude that the various genes appear to differ significantly from each other in their relative sensitivity to mutation by EMS vs. X rays.
EFFECT OF DIETARY AFLATOXIN CONCENTRATION ON THE ASSESSMENT OF GENETIC VARIABILITY OF RESPONSE IN A RANDOMBRED POPULATION OF CHICKENS
Authors: Lanza G M , Washburn K W , Wyatt R D , Marks H L
Published: January 2021

The effect of graded levels of dietary aflatoxin on the assessment of genetic variability of body weight and gain and plasma protein response was tested utilizing the Athens-Canadian randombred population of chickens. Dietary aflatoxin was administered at levels of either 0, 1.25, 2.50 or 5.0 µg/g of diet ad libitum from 7 to 21 days of age to progeny from 58 sire families. Twenty-one-day body weights, gain and plasma protein concentration were used to assess the variation in response.—The administration of increasing levels of aflatoxin resulted in a dose-related decrease of gains and plasma protein concentrations. Plasma protein concentrations were significantly higher among males than females within the control group; however, this difference was reversed as the severity of the aflatoxin challenge increased. Heritability estimates for all responses increased as the level of aflatoxin administered increased. This change was most notable for total plasma protein concentration. Phenotypic correlations for plasma protein concentration and growth measurements tended to diminish with increasing levels of aflatoxin. A similar trend was noted for the genetic correlations; however, a moderate correlation between growth responses and plasma protein response was detected in the 5.0-µg/g aflatoxin treatment group. Genetic correlations were calculated for the same characters between the different levels of aflatoxin. Regardless of which aflatoxin challenges were compared, a very high genetic correlation for 21-day body weight and 7- to 21-day gain was estimated. This variation in growth potential in the toxic environment paralleled that observed in the control environment but at a lower plane. Genetic correlations for plasma protein response across aflatoxin levels diminished as the difference between the levels of aflatoxin administered increased. Plasma protein concentration in the control environment was positively correlated with plasma protein response in groups fed a low level of aflatoxin, but negatively correlated when an aflatoxin challenge of 2.5 µg/g or more was given, suggesting that selection for aflatoxin resistance using plasma protein response as a selection criterion should be made under an aflatoxin stress environment.
HOMOLOGOUS CHROMOSOME PAIRING REMAINS AN UNSOLVED PROBLEM: A TEST OF A POPULAR HYPOTHESIS UTILIZING MAIZE MEIOSIS
Authors: Maguire Marjorie P
Published: January 2021

A recently proposed and popular model for the mechanism of meiotic homologue pairing relies on prior association of nonhomologous chromosome arms of most similar length. According to this model, the diploid complement is organized into two genomic linear chains, each containing the various heterologues in the same sequence. At meiosis, then, appression of the two genomic chains could presumably readily accomplish homologue pairing. This model fails in its simplest form when observations of meiotic pairing of homologues in heterozygotes for arm length alterations are compared with computer-simulated predictions of the model. Contrary to predictions of the model, heterozygotes for arm length changes were found to exhibit only small frequencies of homologue-pairing failure, and this only for a single homologue pair in each case. It is difficult to conceive of a reasonable modification of this model that would be consistent with the observations.
ALTERNATE-2 DISJUNCTION IN THE GERMAN COCKROACH
Authors: Cochran Donald G
Published: January 2021

The evidence in support of two types of alternate disjunction in translocation heterozygotes from the German cockroach, Blattella germanica(L.), is reviewed. When unique cytomorphological features occur in the translocation figure, the two types of alternate disjunction are identifiable regardless of the angle of observation. Photographs supporting this contention are presented for alternate-1 and alternate-2 disjunction in T(7;12)/7;12. Other evidence in support of the existence of alternate-2 disjunction is also presented.
THE INTERACTIONS OF THREE WIDELY SEPARATED LOCI CONTROLLING CONVERSION PROPERTIES OF w LOCUS I IN ASCOBOLUS IMMERSUS
Authors: Helmi Shaker , Lamb Bernard C
Published: January 2021

Gene conversion properties of white (w) ascospore locus I in the Pasadena strains of Ascobolus immersus are controlled by complex interactions between three separate conversion control factors (ccfs), which can give conversion frequencies at wI ranging from less than 1% up to 33%. ccf-2, which has three alleles, is very closely linked to wI but does not usually co-convert with it. ccf-2(K) and ccf-2(91) give lower conversion frequencies than ccf-2(P) and are incompletely dominant to ccf-2(P), with cis/trans position effects on conversion of wI. The "super" factor (Helmi and Lamb 1979) has two interacting but unlinked components, ccf-3E and ccf-4r, which approximately double the conversion frequency at wI. ccf-2 (linkage group VIII), ccf-3 (linkage group I) and ccf-4 are probably all unlinked but interact and specifically control conversion at wI. ccf-3E could code for a diffusible product that affects the action of different ccf-2 alleles, which probably act by controlling the frequency of initiation of hybrid-DNA, which spreads into the adjacent wI locus. ccf-4R could code for a diffusible inhibitor of ccf-3E product, or be an alternative binding site for ccf-3E product. The dominance of ccf-4R depends on which ccf-2 alleles are present in the cross.