bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic Reconnection during the Post-impulsive Phase of a Long-duration Solar Flare: Bidirectional Outflows as a Cause of Microwave and X-Ray Bursts
Authors: Yu 余思 Sijie 捷 , Chen 陈 Bin 彬 , Reeves Katharine K. , Gary Dale E. , Musset Sophie , Fleishman Gregory D. , Nita Gelu M. , Glesener Lindsay 
Published: August 2020

Abstract
Magnetic reconnection plays a crucial role in powering solar flares, production of energetic particles, and plasma heating. However, where the magnetic reconnections occur, how and where the released magnetic energy is transported, and how it is converted to other forms remain unclear. Here we report recurring bidirectional plasma outflows located within a large-scale plasma sheet observed in extreme-ultraviolet emission and scattered white light during the post-impulsive gradual phase of the X8.2 solar flare on 2017 September 10. Each of the bidirectional outflows originates in the plasma sheet from a discrete site, identified as a magnetic reconnection site. These reconnection sites reside at very low altitudes (<180 Mm, or 0.26 R
⊙) above the top of the flare arcade, a distance only <3% of the total length of a plasma sheet that extends to at least 10 R
⊙. Each arrival of sunward outflows at the loop-top region appears to coincide with an impulsive microwave and X-ray burst dominated by a hot source (10–20 MK) at the loop top and a nonthermal microwave burst located in the loop-leg region. We propose that the reconnection outflows transport the magnetic energy released at localized magnetic reconnection sites outward in the form of kinetic energy flux and/or electromagnetic Poynting flux. The sunward-directed energy flux induces particle acceleration and plasma heating in the post-flare arcades, observed as the hot and nonthermal flare emissions.
Nonlinear Mechanisms that Regulate the Solar Cycle Amplitude
Authors: Jiang Jie 
Published: August 2020

Abstract
The solar magnetic activity cycle has an amplitude that varies within a wide but limited range of values. This implies that there are nonlinear mechanisms that prevent runaway solutions. The purpose of this paper is to propose observable nonlinear mechanisms in the framework of the Babcock–Leighton-type dynamo. Sunspot emergences show systematic properties that strong cycles tend to have higher mean latitudes and lower tilt angle coefficients. We use the surface flux transport model to investigate the effect of these systematic properties on the expected final total dipolar moment, i.e., cancellation plus generation of dipole moment by a whole solar cycle. We demonstrate that the systematic change in latitude has similar nonlinear feedback on the solar cycle (latitudinal quenching) as tilt does (tilt quenching). Both forms of quenching lead to the expected final total dipolar moment being enhanced for weak cycles and saturated to a nearly constant value for normal and strong cycles. This explains observed long-term solar cycle variability, e.g., the Gnevyshev–Ohl rule, which, in turn, justifies the nonlinear mechanisms inherent in the Babcock–Leighton-type dynamo.
Limits to Rest-frame Ultraviolet Emission from Far-infrared-luminous z ≃ 6 Quasar Hosts
Authors: Marshall M. A. , Mechtley M. , Windhorst R. A. , Cohen S. H. , Jansen R. A. , Jiang L. , Jones V. R. , Wyithe J. S. B. , Fan X. , Hathi N. P. , Jahnke K. , Keel W. C. , Koekemoer A. M. , Marian V. , Ren K. , Robinson J. , Röttgering H. J. A. , Ryan R. E. , Scannapieco E. , Schneider D. P. , Schneider G. , Smith B. M. , Yan H. 
Published: August 2020

Abstract
We report on a Hubble Space Telescope search for rest-frame ultraviolet emission from the host galaxies of five far-infrared-luminous z ≃ 6 quasars and the z = 5.85 hot-dust-free quasar SDSS J0005–0006. We perform 2D surface brightness modeling for each quasar using a Markov Chain Monte Carlo estimator, to simultaneously fit and subtract the quasar point source in order to constrain the underlying host galaxy emission. We measure upper limits for the quasar host galaxies of m

J
> 22.7 mag and m

H
> 22.4 mag, corresponding to stellar masses of M
* < 2 × 1011
M
⊙. These stellar mass limits are consistent with the local M
BH − M
* relation. Our flux limits are consistent with those predicted for the UV stellar populations of z ≃ 6 host galaxies, but likely in the presence of significant dust (

mag). We also detect a total of up to nine potential z ≃ 6 quasar companion galaxies surrounding five of the six quasars, separated from the quasars by 1.″4–3.″2, or 8.4–19.4 kpc, which may be interacting with the quasar hosts. These nearby companion galaxies have UV absolute magnitudes of −22.1 to −19.9 mag and UV spectral slopes β of −2.0 to −0.2, consistent with luminous star-forming galaxies at z ≃ 6. These results suggest that the quasars are in dense environments typical of luminous z ≃ 6 galaxies. However, we cannot rule out the possibility that some of these companions are foreground interlopers. Infrared observations with the James Webb Space Telescope will be needed to detect the z ≃ 6 quasar host galaxies and better constrain their stellar mass and dust content.
Distortion of Magnetic Fields in the Dense Core SL 42 (CrA-E) in the Corona Australis Molecular Cloud Complex
Authors: Kandori Ryo , Tamura Motohide , Saito Masao , Tomisaka Kohji , Matsumoto Tomoaki , Tazaki Ryo , Nagata Tetsuya , Kusakabe Nobuhiko , Nakajima Yasushi , Kwon Jungmi , Nagayama Takahiro , Tatematsu Ken’ichi 
Published: August 2020

Abstract
The detailed magnetic field structure of the dense core SL 42 (CrA-E) in the Corona Australis molecular cloud complex was investigated based on near-infrared polarimetric observations of background stars to measure dichroically polarized light produced by magnetically aligned dust grains. The magnetic fields in and around SL 42 were mapped using 206 stars, and curved magnetic fields were identified. On the basis of simple hourglass (parabolic) magnetic field modeling, the magnetic axis of the core on the plane of the sky was estimated to be 40° ± 3°. The plane-of-sky magnetic field strength of SL 42 was found to be 22.4 ± 13.9 μG. Taking into account the effects of thermal/turbulent pressure and the plane-of-sky magnetic field component, the critical mass of SL 42 was obtained to be M
cr = 21.2 ± 6.6 M
⊙, which is close to the observed core mass of M
core ≈ 20 M
⊙. We thus conclude that SL 42 is in a condition close to the critical state if the magnetic fields lie near the plane of the sky. Because there is a very low-luminosity object toward the center of SL 42, it is unlikely that this core is in a highly subcritical condition (i.e., the magnetic inclination angle is significantly deviated from the plane of the sky). The core probably started to collapse from a nearly kinematically critical state. In addition to the hourglass magnetic field modeling, the Inoue & Fukui mechanism may explain the origin of the curved magnetic fields in the SL 42 region.
Discovery of State Transition Behaviors in PSR J1124–5916
Authors: Ge M. Y. , Yuan J. P. , Lu F. J. , Tong H. , Zhou S. Q. , Yan L. L. , Wang L. J. , Tuo Y. L. , Li X. F. , Song L. M. 
Published: August 2020

Abstract
With the 12 year long observations by Fermi-LAT, we discover two pairs of spin-down state transitions of PSR J1124–5916, making it the second young pulsar detected to have such behaviors. PSR J1124–5916 shows mainly two states according to its spin-down rate evolution, the normal spin-down state and the low spin-down state. In about 80% of the observation time, the pulsar is in the normal spin-down state, in which the spin-down rate decreases linearly and gives a braking index of 1.98 ± 0.04. The two transitions to the low spin-down state are in MJD 55183–55803 and MJD 56114–56398, respectively, with fractional amplitudes both ∼0.4%. No significant difference between the γ-ray profiles of the two spin-down states is detected, which is similar to PSR B0540–69, the other young pulsar with state transition detected.
Development of a single nucleotide polymorphism-based DNA marker for fall armyworm (Lepidoptera: Noctuidae) biotyping: a case study from the fall armyworm outbreak in Sri Lanka
Authors: Nanayakkara Dhanesha , Jayatilake Dimanthi , Kodithuwakku Suranga 
Published: August 2020

AbstractCrop damage caused by fall armyworm (FAW), Spodoptera frugipera J.E. Smith (1797) (Lepidoptera: Noctuidae), has generated concern among agriculturists globally. In 2019, FAW was first reported in Sri Lanka, where it caused significant losses to corn crops. However, given that the two FAW biotypes – “rice strain” (R-FAW) and “corn strain” (C-FAW) – are morphologically identical, the biotype(s) present in Sri Lanka were unknown. The current study used the mitochondrial cytochrome c oxidase subunit I gene (mt-CO1) of FAW to biotype nine FAW samples collected in Sri Lanka. The resulting molecular phylogeny revealed that both R-FAW and C-FAW biotypes were present among the samples. In addition, we used the temperature-switch polymerase chain reaction (PCR) technique to develop a gel-based molecular marker. Two fragments were successfully amplified by the newly developed marker ABUOP0002, with fragment sizes of 341 bp from R-FAW and 204 bp from C-FAW. This demonstrates that ABUOP0002 can serve as a diagnostic gel-based molecular marker to identify the R-FAW and C-FAW biotypes from samples already identified to species level as S. frugiperda through taxonomical keys and provides a possible alternative to more expensive sequencing-based assays.
Health Information Use by Resident Doctors in Lagos State University Teaching Hospital, Ikeja, Lagos State, Nigeria
Authors: Ehioghae Maria , Madukoma Ezinwanyi 
Published: August 2020

The study interrogates health information use by resident doctors in Lagos State University Teaching hospital (LASUTH), Lagos State. Health information has been variously described as the “foundation” for better health, as the “glue” holding the health systems together and as the “oil” keeping the health systems running. It is important for making the right clinical decisions and enhancing professionalism. A survey research design was adopted by the study and the enumeration technique was used to cover all 115 resident doctors that constituted the population. Out of the 115 questionnaire copies administered, 94 copies were returned for data analysis, making the response rate to be 81.7%. The data collected were analyzed using frequency counts and percentages. Findings revealed that the majority of resident doctors in LASUTH have access and use, to a large extent, health information for clinical decision-making. It is, however, recommended that to improve on health information sharing, workshops and seminars on health information should be regularly conducted for resident doctors in LASUTH. This, expectedly, will expose them to new health information trends that will enhance their clinical experience.
Keywords: Health Information, Information Use, Resident Doctors, Clinical Decision-making
Assessment of ICT Skills of LIS Educators for the Adoption of Blended Learning in Rivers State, Nigeria
Authors: Ahaiuzu Blessing E. , Nyemezu Chidaka O. , Nsirim Onyema 
Published: August 2020

The study assessed ICT skills of Library and Information Science (LIS) educators for the adoption of Blended Learning in Rivers State. The study adopted a descriptive survey design, with a population of 45; census sampling technique was adopted to sample all the 45 library educators in four library schools in Rivers. A structured questionnaire was used to gather data for the study. 42 copies of the instrument were returned and found valid for analysis. The data collected were analyzed using mean scores and simple percentages. The findings revealed that despite the fact that LIS educators could use basic computer interfaces, mobile and new media technologies for blended learning, they were not adopting blended learning. The challenges were attributed to lack of facilities, lack of skills and lack of policy. It was therefore, recommended among other things that Librarians’ Registration Council of Nigeria should formulate a policy that will motivate and guide the use of blended learning in LIS education and LIS educators should acquire skills to exploit blended learning.
Keywords: ICT Skills, LIS Educators, Blended Learning, Rivers State
Connaissances traditionnelles des plantes locales utilisées contre les bio-agresseurs des cultures et produits agricoles chez le peuple Turka au Burkina Faso
Authors: Sourabie Soumaïla , Zerbo Patrice , Yonli Djibril , Boussim Joseph I. 
Published: August 2020

La présente étude a pour objectif de faire l’état des connaissances traditionnelles endogènes relatives aux plantes locales utilisées contre les bio-agresseurs des cultures et des produits agricoles. A travers une série d’enquêtes ethnobotaniques réalisée de 2018 à 2019 dans la région des Cascades au Burkina Faso, 150 personnes appartenant à l’ethnie Turka ont été interviewées. Les informations recherchées en utilisant des entretiens semi-directifs, ont concerné les noms locaux des plantes, les parties utilisées, les domaines d’utilisation et leurs modes d'utilisation. Les données collectées ont permis de recenser 33 espèces de plantes réparties en 30 genres et 19 familles utilisées traditionnellement contre les bio-agresseurs agricoles. Ces plantes interviennent sélectivement dans trois domaines : la répulsion des insectes, l’inhibition des herbes envahissantes et la construction des greniers. Les espèces sont utilisées soit directement ou transformées en poudre ou en cendre. Les feuilles sont plus utilisées que les autres organes. Cassia nigricans est l’espèce la plus utilisée pour son effet répulsif et Parkia biglobosa pour son effet inhibiteur. Des études approfondies sur les propriétés chimiques des potentielles espèces permettront de réduire l’impact des produits chimiques en agriculture contre les bio-agresseurs.Mots clés : Ethnobotanique, diversité végétale, ennemi agricole, secteur sud-soudanien, Afrique de l’ouest
English Title:Traditional knowledge of local plants used against pests of crops and agricultural products among the Turka poeple in Burkina Faso
The objective of this study is to provide an overview of endogenous traditional knowledge relating to local plants used against pests of crops and agricultural products. Through an ethnobotanical’s surveys carried out from 2018 to 2019 in the Cascades area in Burkina, 150 Turka ethnic group people were interviewed. Through semi-structured interviews, information looking for were concerned plants local names, their parts used, the domains and the modes of use. Data collected allowed to identify 33 plants’ species belonged to 30 genera and 19 families, used traditionally against agricultural pests. These plants are selectively involved in three domains: repelling insects, inhibiting invasive weeds and building lofts. Species are used either directly or processed into powder or ash. The leaves are used more than other organs. Cassia nigricans is the most used species for its repellent effect and Parkia biglobosa for its inhibitory effect. In-depth studies on the chemical properties of potential species will reduce the impact of chemicals in agricultural against pests.Keywords: Ethnobotany, plant diversity, agricultural pest, South Sudanese sector, West Africa
Effet des coûts de transaction sur la performance économique et l’adoption du coton biologique au Centre et Nord du Bénin
Authors: Agalati Barnabé , Degla Pamphile 
Published: August 2020

Face au défi de la dégradation de l’environnement et des problèmes sanitaires liés à la production du coton conventionnel au Bénin, la production du coton biologique initiée depuis quelques décennies peine à se développer. Cet article s’intéresse à l’analyse de l’effet des coûts de transaction (CT) sur la performance économique et l’adoption du coton biologique au Centre et au Nord du Bénin. Basée sur un échantillon aléatoire de 408 producteurs dont 168 adoptants du coton biologique, l’étude a utilisé l’approche d’estimation des CT, la régression logistique et le test t de Student pour l’analyse des données. Les résultats montrent que les CT, plus élevés dans le système du coton biologique réduisent considérablement la performance économique de ce système et affectent négativement la probabilité de son adoption. Outre cet effet, il ressort également l’influence négative d’autres facteurs tels que le sexe, le niveau de rendement, la distance domicile-exploitation, le nombre d’années d’expérience dans la production cotonnière et le mode de faire valoir direct sur l’adoption du coton biologique. La formation technique dans la production du coton biologique et la situation géographique exercent par contre une influence positive sur l’adoption du coton biologique.Mots clés : Déterminants, système de production, économie néo-institutionnelle, agriculture biologique
English Title: Effect of transaction costs on the economic performance and the adoption of organic cotton in central and northern Benin
Regarding the environmental degradation challenge and health problems due to the production of conventional cotton in Benin, organic cotton production initiated several decades ago is struggling to develop. This paper focuses on analyzing the effect of transaction costs on the economic performance and the adoption of organic cotton in central and northern Benin. The study is based on a random sample of 408 producers, including 168 adopters of organic cotton. The transaction costs estimation approach, the logistic regression and the Student's t-test were used for data analysis. The results show that the high transaction costs in the organic cotton system significantly reduce the economic performance of this system and negatively affect the probability of adoption of organic cotton. In addition, there is the negative influence of other factors such as gender, the level of yield, the distance from home to farm, the years of experience in cotton production as well as the direct tenure mode in the adoption of organic cotton. On the other side, technical training in the production of organic cotton and the geographic location have a positive influence on the adoption of organic cotton.Keywords: Determinants, production system, new institutional economics, organic production.
Assessment of the viability of climate adaptation strategies of cassava-based farmers in southern Nigeria
Authors: Henri-Ukoha A. 
Published: August 2020

The study examined the viability of climate adaptation strategies of cassava-based farmers in Southern Nigeria. A total of 300 cassava-based farmers were randomly selected. Primary data were obtained through administration of questionnaire, interview schedule and Focus Group Discussion (FGD). Data were analysed using descriptive statistics which involved the use of percentages, mean and frequency distributions as well as OLS multiple regression model. The specific objectives include: to describe the socio-economic characteristics of the farmers, identify the climate change adaptation practices employed, ascertain the viability of the climate change adaptation practices and to determine the factors influencing the use of climate change adaptation strategies by the cassava-based farmers in the study area. Results show that majority of the cassava-based farmers were females, married, had a mean age of 46 years, 19 years farming experience, household size of 8 persons, and mean farm size of 1.23 hectares. Results further showed that the cassava farmers adopted various of adaptation strategies such as mixed cropping 24.3%, crop rotation 16.3%, change in planting date 36.6%, use of improved varieties 63.2%, minimum tillage 37%, early and late planting 35.3% and 13.5% respectively. These practices facilitated the adaptation to climate change by the farmers. However, farming experience, farm size, education, access to extension services, credits and farm income influenced the viability of the climatic adaptation strategies of the cassava-based farmers in the area. Farmers are advised to take good advantage of seminars, workshops, symposiums, and conferences on climate change and its implications on agricultural production.
Keywords: Assessment; Viability; Adaptation, Climate Change, Strategies, Cassava-based Farmers
Effects of different synthetic hormone preparations on fertilization and hatching in <I>Clarias gariepinus</I> (Burchell, 1822)
Authors: Uka A. , Asangusung P.S. , Okoro G.G. 
Published: August 2020

The effect of different synthetic hormonal preparations on fertilization and hatching in Clarias gariepinus was investigated. The fish were injected with three different synthetic hormones namely: ovaprim, ovulin, and carp pituitary extracts (CPE) designated as treatments A, B, and C respectively. These were all replicated three times in a complete randomized design. The eggs were monitored until fertilization and hatching were completed. The results of the experiment were subjected to Analysis of Variance (ANOVA). From the results, treatment B had the highest percentage fertilization (79.4%) and hatchability (80.0%), which were significantly different (p>0.05) from both treatments A and C. Treatment C had the least values of 67.7% and 62.30%. There were no significant differences (p>0.05) amongst the water parameters of the culture units examined during the experimental period. The results of this study showed that all the three hormones yielded good performance but ovulin was the best preferred.
Keywords: Ovaprim, ovulin, fertilization, hatching, C. gariepinus.
Microflora of smoked <I>Trachurus trachurus</I> and <I>Scomber scombrus</I> samples in Orlu South East, Nigeria and its implication on public health
Authors: Agbabiaka L.A. , Agu C.O. 
Published: August 2020

The study was carried out to assess the microbiological quality of smoked Trachurus trachurus and Scomber scumbrus in four markets in Orlu Local Government Area, South East, Nigeria. Forty freshly smoked samples of Trachurus trachurus and Scomber scumbrus were procured from Eke Eziachi, Orlu Main, Aforaja Umuowa and Afor Ogidi Ihioma markets and analyzed using standard techniques. Results revealed that Orlu main market had the highest level of microbial contamination (mean bacteria and fungi count of 5 x 102 and 10 x 102cfu/g respectively). The highest total viable count (7 x102 cfu/g) of Scomber scumbrus was obtained in Aforaja Umuowa market while the least value of 2 x102 cfu/g was observed in Afor Ogidi Ihioma market. Also, similar value was recorded in Trachurus trachurus at Aforaja Umuowa market. Results from the study indicated that pathogens present in fish samples included bacteria (Bacillus cereus, B. subtilis, Escherichia coli, Salmonella spp and Staphylococcus aureus) and fungi (Gliocladium spp., Candida spp., Rhizopus spp., Alternaria spp., Aspergillus spp., Clasdosprium spp., Fonsecaca spp., Chrysoporius spp., mucour spp. and Botrytis spp). The study also showed that freshly smoked Trachurus trachurus and Scomber scumbrus samples sold in the four markets under assessment were contaminated with pathogenic organisms. This may however present some public health implications.
Keywords: Microbial activity, Smoked fish, Orlu, Fish quality; Hygiene