bluuebunny/crossref_metadata_2025 huggingface dataset:
Chondrichthyan specimens housed at the Colección del Laboratorio de Ecología of the Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México
Authors: Guzmán A. F. , Meráz -Munguí­a M. A.
Published: December 2020

A review of the chondrichthyan specimens housed in the Laboratorio de Ecología Collection of the Escuela Nacional de Ciencias Biológicas (ENCB-IPN-LEM) was carried out. Activities included: 1) verifying the curatorial status and identity of the specimens, 2) a review of the field information, and 3) construction of a database. Currently, there are 371 specimens of 11 orders, 20 families, 32 genera and 56 species included in the collection. Higher taxonomic categories are well represented, unlike lower ones. Captures from 1940 to 1991 comprise 93 localities from all Mexican coastal states, plus one foreign locality. Specimens of Cephaluruscephalus and Isistius brasiliensis are relevant because of their infrequent capture and the generated information. Other specimens allow correcting and increasing geographic and descriptive information for Zapteryx xyster,Rhinobatos spinosus, R. productus and Carcharhinus isodon.
Effect of Food Enrichment on the Survival of Hippocampus Ingens Girard, 1858 Alevine under Semicontroled Conditions
Authors: Ortí­z -Aguirre Ismael , Rangel Dávalos Carlos , Pacheco -Vega Juan Manuel
Published: December 2020

Due to the decline in seahorse populations generated by exploitation and degradation of their habitat, an attempt has been made to obtain the closed cycle of cultivation of different species of the genus, includingH. ingens, the unique specie located in the Eastern Pacific. In the majority of the studies carried out, the mainlimitation has been the provision of a diet that supplies an adequate growth and survival of the organisms. The objective of this research was to determine the effect of nutritional enrichment of Brachionus plicatilis and Artemiafranciscana, used as food in the survival of H. ingens. Fifteen specimens of wild adult seahorses were capturedin Bahía de La Paz, and generated four couples and 17 successful batches. To assess the enrichment from thethird to the seventh day, each batch was divided into six groups and placed in 60-liter aquaria, feeding on rotifersmaintained with six different treatments. Three Artemia franciscana nauplii enrichment treatments were thentested to evaluate the effect on the survival of the juveniles in the period from day eight to day 60. From day 61and on seahorses were fed with adult Artemia franciscana also enriched with the three different treatments. Theseresults show that the enrichment of the food offered in the first months of life of seahorses has a significant effecton their survival.
Characterization of a new Dunalliela salina strain isolated from San Quintin, Baja California (México) producer of lipids, pigments and micronutrients
Authors: Valencia Ricardo , Giffard-Mena Ivone , Cruz-López Ricardo , Garcí­a-Mendoza Ernesto , Stephano-Hornedo José Luis
Published: December 2020

Some microalgae are recognized for producing pigments and other metabolites with biotechnological importance, particularly, Dunaliella salina is a remarkable one. These kind of compounds are used as food and have a great industrial potential. The pigment industry comprises a millionaire market value, being Î²-carotene one of the most profitable one. In this study we describe the morphology, molecular identification, growth dynamics, proximal composition, nutrients and pigment content of a recently isolated Dunaliella salina strain (SQ) under different salinity/light conditions, in order to highlight its remarkable properties for biotech/biomed industry. D. salina SQ reached the highest densities (1.07-1.25 cell mL-1 x106) at low salinities (100-500 mM NaCl) under continuous light regimen (24:0 h Light:Dark). Neoxanthin (Neo) and violaxanthin (Viol) were the most abundant pigments when exposed to 500 mM NaCl (18:6 h Light:Dark). Furthermore, this peculiar strain produces other compounds with high industrial value.
Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities
Authors: Kiesewalter Heiko T , Lozano-Andrade Carlos N , Strube Mikael L , Kovács Ákos T
Published: December 2020

Secondary metabolites provide Bacillus subtilis with increased competitiveness towards other microorganisms. In particular, nonribosomal peptides (NRPs) have an enormous antimicrobial potential by causing cell lysis, perforation of fungal membranes, enzyme inhibition, or disruption of bacterial protein synthesis. This knowledge was primarily acquired in vitro when B. subtilis was competing with other microbial monocultures. However, our understanding of the true ecological role of these small molecules is limited. In this study, we have established soil-derived semisynthetic mock communities containing 13 main genera and supplemented them with B. subtilis P5_B1 WT, the NRP-deficient strain sfp, or single-NRP mutants incapable of producing surfactin, plipastatin, or bacillaene. Through 16S amplicon sequencing, it was revealed that the invasion of NRP-producing B. subtilis strains had no major impact on the bacterial communities. Still, the abundance of the two genera Lysinibacillus and Viridibacillus was reduced. Interestingly, this effect was diminished in communities supplemented with the NRP-deficient strain. Growth profiling of Lysinibacillus fusiformis M5 exposed to either spent media of the B. subtilis strains or pure surfactin indicated the sensitivity of this strain towards the biosurfactant surfactin. Our study provides a more in-depth insight into the influence of B. subtilis NRPs on semisynthetic bacterial communities and helps to understand their ecological role.
Pengaruh Kinerja Keuangan Terhadap Return Saham Perusahaan Badan Usaha Milik Negara
Authors: Widiana Alfi , Yustrianthe Rahmawati Hanny
Published: December 2020

Abstract

This objective of this research is to investigate  the influence of current ratio, cash ratio, debt ratio to stock returns.  The sample is selected by purposive sampling method, ie sampling technique using a  certain considerations that are relevant  to the selected sample research purposes. The number of samples obtained are 20 BUMN companies listed on the Indonesia Stock Exchange. The results of this study indicate that the current ratio and cash ratio as a measurement of financial performance have a positive and significant effect on stock returns. While the debt ratio has a negative and insignificant effect on stock returns.

Keywords : Financial Performance, Financial Ratios, Stock Return.

 

Abstrak

Penelitian ini bertujuan untuk menganalisa pengaruh current ratio, cash ratio, debt ratio terhadap return saham. Penentuan sampel dilakukan dengan menggunakan metode purposive sampling, yaitu teknik sampling dengan menggunakan pertimbangan dan batasan tertentu sehingga sampel yang dipilih relevan dengan tujuan penelitian. Jumlah sampel yang diperoleh sebanyak 20 perusahaan BUMN yang terdaftar di Bursa Efek Indonesia. Data dianalisis dengan analisis deskriptif dan analisis regresi berganda. Hasil dari penelitian ini mengindikasikan bahwa current ratio dan cash ratio sebagai pengukuran kinerja keuangan memiliki pengaruh positif dan signifikan terhadap return saham. Sedangkan debt ratio berpengaruh negatif dan tidak signifikan terhadap return saham.

Kata Kunci : Kinerja Keuangan, Rasio Keuangan, Return Saham.
Pengaruh Materialitas, Etika Auditor dan Independensi Auditor Terhadap Opini Audit
Authors: Ilhamsyah Haikal Rafif , Nopiyanti Anita , Mashuri Ayunita Ajengtiyas Saputri
Published: December 2020

Thisxresearchzisxusingxquantitivezstudyzaimedxtossee whatever theresare the effect ofsmateriality, auditor ethics and auditor independence on thesprovision of giving auditsopinion. This study uses primary data with respondents are senior auditors working in accountant publik firm in the DKI Jakarta. Testing the hypothesis in the study was used Multiple Linier Regression Analysys using SPSS analisys tool with a significant level of 5% (0,05). The Result of these test indicate that (1) there is significant influence materiality on provision of audit opinion, (2) there is no significant influence auditor ethics on provision of audit opinion, (3) there is no significant influence auditor independence on provision of audit opinion
THE VALVATA SPECIES OF TURKEY WITH A DESCRIPTION OF VALVATA KEBAPCII N. SP. (MOLLUSCA: VALVATIDAE)
Authors: Odabaşi Deniz Anil , Glöer Peter , Yildirim Mehmet Zeki
Published: December 2020

The family Valvatidae Gray 1840 has a widespread distribution in the Holarctic. To date, four species of the genus Valvata have been reported from Turkey: V. cristata O.F. Müller 1774, V. piscinalis (O.F. Müller 1774), V. saulcyi Bourguignat 1853 and V. macrostoma Mörch 1864. This study is based on recently collected materials from the comprehensive field survey at Biga Peninsula streams, northwestern Anatolia, between 2009 and 2011. Additional materials were also examined from Cire Brook, Isparta, southwestern Anatolia, Turkey. Valvata kebapcii sp. n. is described here as new for science. Further research is required in order to reveal exact ranges of dispersal of the new Valvata species in Turkey.
BYTHINELLA MELOVSKII N.SP., A NEW SPECIES FROM R. MACEDONIA (GASTROPODA: HYDROBIIDAE)
Authors: Glöer Peter , Slavevska-Stamenković Valentina
Published: December 2020

A new Bythinella species has been found in the Balkans,  Bythinella melovskii n. sp. from Macedonia. The holotypes as well as the penis morphology are depicted. In addition a distribution map of the Bythinella spp. of this region is provided.
CERATOMEGILLA ALPINA (VILLA & VILLA, 1835) (COLEOPTERA, COCCINELLIDAE) IN BOSNIA AND HERZEGOVINA AND THE DINARIC ALPS
Authors: Kulijer Dejan
Published: December 2020

In this paper new records of Ceratomegilla alpina (Villa & Villa, 1835) (Coleoptera, Coccinellidae) from Bosnia and Herzegovina and the Dinaric Alps are given.
FIRST RECORD OF THREE MITE SPECIES (ACARI) IN GREECE COLLECTED ON COMMERCIAL BUMBLEBEE (HYMENOPTERA: APIDAE: BOMBUS TERRESTRIS LINNAEUS, 1758)
Authors: Kontschán Jenő
Published: December 2020

In this paper the first record of three mite species (Acari) in Greece collected on commercial bumblebee (Hymenoptera: Apidae: Bombus terrestris Linnaeus, 1758) is given.
NOTES ON THE HERPETOFAUNA OF ISMAROS MTS. (NORTHERN GREECE, RHODOPI COUNTY)
Authors: Georgiev Dilian , Mollov Ivelin
Published: December 2020

In this paper notes on the herpetofauna of Ismaros Mts. (Northern Greece, Rhodopi County) are given.
ONE NEW SPECIES OF THE FAMILY NIPHARGIDAE FROM BOSNIA AND HERZEGOVINA (CONTRIBUTION TO THE KNOWLEDGE OF THE AMPHIPODA 289)
Authors: Karaman Gordan S.
Published: December 2020

From the subterranean waters of the Velika Bukovička špilja Cave near Bukovica village (Tomislavgrad region, Bosnia and Herzegovina) is described and figured one new species of the family Niphargidae (Amphipoda, Gammaridea), Niphargus bukovicensis, sp. n. This species is characterized by presence of elevated number of spines on dactylus of pereopods 6 and 7 only, by numerous setae along dactylus outer margin of gnathopods 1-2, pointed epimeral plate 3 and by elongated inner and outer ramus of uropod 3 in males. The taxonomical relation of this species regarding other similar members of genus Niphargus Schiödte, 1849, is discussed.
THE FRUIT BEAUTY MOTH, LYCIA POMONARIA (HÜBNER, 1790) (LEPIDOPTERA: GEOMETRIDAE) A NEW MEMBER OF THE MOTH FAUNA OF CROATIA
Authors: Koren Toni
Published: December 2020

In this paper. the fruit beauty moth, Lycia pomonaria (Hübner, 1790) (Lepidoptera: Geometridae) is reported for the first time for the moth fauna of Croatia.
FIRST RECORD OF THE GENUS AETHALIDA WALKER, 1865 (LEPIDOPTERA: EREBIDAE: ARCTIINAE) FROM FLORES ISLAND, EAST NUSA TENGGARA, INDONESIA
Authors: Spitsyn Vitaly M. , Bolotov Ivan N. , Gofarov Mikhail Y. , Bolotov Nikita I.
Published: December 2020

The discussed record marks presence of the genus Aethalida Walker, 1865 in East Nusa Tenggara (Flores Island, Indonesia) for the first time. We have found that a specimen from Flores Island shows great similarity with A. owadai Dubatolov & Kishida, 2005, an endemic species of Selayar Island. Comparing external morphology of A. owadai and the discussed specimen, we were able to highlight some key differences in structure of the male genitalia and in the markings pattern. The given morphological features are sufficient to establish a new subspecies, A. owadai floresiensis ssp. n.
RED-BELLIED PIRANHA PYGOCENTRUS NATTERERI KNER, 1858 (CHARACIFORMES: SERRASALMIDAE) IN OPEN WATERS IN R. MACEDONIA
Authors: Kostov Vasil , Ristovska Milica , Arsovska Julijana , Jordanova Maja , Prelik Dana
Published: December 2020

There are so many reports of introduction of non-native fish species in Europe but reports including introduction of species from Serrasalmidae, especially from piranhas fish are scarce. This paper documents the first record of the occurrence of the exotic red bellied piranha, in Dojran Lake, the southern part of Republic of Macedonia. The morphological taxonomy revealed that the specimen is Pygocentrus nattereri Kner, 1860.
GLOSSIPHONIA BALCANICA N. SP. AND DINA PROKLETIJACA N. SP. (HIRUDINIDA: GLOSSIPHONIIDAE, ERPOBDELLIDAE) - TWO NEW LEECHES FROM MONTENEGRO AND KOSOVO
Authors: Grosser Clemens , Pešić Vladimir , Berlajolli Violeta , Gligorović Bogić
Published: December 2020

Two new leech species (Hirudinida) representing the families Glossiphoniidae (Glossiphonia balcanica n. sp.) and Erpobdellidae (Dina prokletijaca n. sp.) are described. The populations from Montenegro assigned by Utevsky et al. (2013) and Grosser et al. (2015) to Glossiphonia nebulosa Kalbe, 1964 represent an new species, here described as G. balcanica n. sp. The new species can be easily be separated from Glossiphonia nebulosa by the reduction of the papillae. Dina prokletijaca n. sp. closely resembles D. dinarica Sket, 1968 and D. montana Sket, 1968 from which can be distinguished in the combination of the small and stocky body, dorsal surface with two wide and dark paramedian longitudinal stripes and ovisacs reaching the fourth somite after the female genital pore, and curled in their entire course. A key to the species of Glossiphonia Johnson, 1816 and Dina R. Blanchard, 1892 from the Western Balkans is presented.
HIRMONEURA OBSCURA (WIEDEMANN IN MEIGEN, 1820) REPRESENTS A FAMILY NEW TO ALBANIA
Authors: Katona Patrik
Published: December 2020

In this paper Hirmoneura obscura (Wiedemann in Meigen, 1820) (Diptera) is reported for the first time for Albania.
Some Aspects of Working Practices at the Department of State Protocol of the Ministry of Foreign Affairs of Ukraine
Authors: Lazuto Yurii
Published: December 2020

Abstract. The article is devoted to the international situation in Europe and USSR’s foreign policy before and after the outbreak of World War II. The author states that from the very beginning the fascist regime in Germany was favourably received by Stalin’s USSR. Hitler also claimed that the German government was ready to develop friendly relations with the Soviet Union. However, such a situation in the bilateral relations was short-lived. Seeking benevolence from Western European countries, Hitler assumed the role of an anti-communist crusader. With a view to strengthening the country’s security, countering Germany and fascism, Stalin gave up his ideological dogmas in line with the situation. Moscow came to vigorously support all political forces, which were advocating closer relations with the USSR against fascism.
After Germany attacked the Soviet Union, Stalin’s foreign policy suffered a total collapse, which was a devastating blow to the myth of his brilliance and sagacity. The glorification of fascism and the policy of its befriending came at a cost. Nearly 50 million Soviet citizens perished in the war against the fascist Germany, of which 10 million were Ukrainian nationals.
In Russia, both public officials and scholars still avoid the truth about the foreign policy activity of the Soviet leadership in 1939 and 1940s. In this regard, the Ukrainian historian and specialist in international relations, professor at Kyiv Pedagogical University Anatolii Trubaichuk was the first in the Soviet Union to tell the truth in his writings and lectures about the essence of the Soviet foreign policy before and after the beginning of World War II based on his profound scientific research.
The author stresses that the search for full truth is to be continued. To that end, it is necessary that all the archives in Russia be opened and access to documents relating to the period of World War II be provided.
Keywords: World War II, foreign policy, Soviet Union, Stalin, Germany.
AUXILIARY FUNCTION GRADIENT APPROACH TO MARINE VEHICLE PATH-FOLLOWING CONTROL
Authors: Dyda Alexander A. , Chumakova Ksenya N. , Pushkarev Igor I.
Published: December 2020

This paper develops an approach to solving the problem of controlling the movement of a ship along a route. It is assumed that the route is specified using waypoints connected by line segments. The main idea of ​​the developed approach is to construct a set of auxiliary smooth functions having an extremum (maximum) on the corresponding sections of the route. The gradient vectors of the selected auxiliary functions are directed towards the corresponding section of the vessel's route. The sum of the vectors of the gradient of the auxiliary functions and the vector that specifies the direction on the selected section of the route determines the desired course of the vessel movement. It is shown that the chosen constructing algorithm for the desired vessel course ensures its output to the given trajectory.
JUSTIFICATION FOR THE EXPEDIENCY OF SHIP RECYCLING
Authors: Kochnev Yuri A. , Kochneva Irina B.
Published: December 2020

The decision of a ship recycling is usually made only on the basis of economic considerations – the possibility of selling materials and equipment for reuse. But the actual damage to the environment is not estimated, as from a disposition (emissions from cutting and storage of waste which is not a subject to further use and processing) and the ship storage on the certain territory which is either a coastline or a section of backwater, and which in most cases is not designed for this. The article considers the approach allowing to estimate the environmental effect of cutting up a ship, in comparison with its storage in a conditionally unlimited time interval. An unambiguous conclusion was obtained about the effectiveness of this type of treatment of the ship as waste. The method for determining a certain conditional time for making a decision on the method and place of recycling, applicable to a ship that is in an unsuitable technical condition is proposed.
RESEARCH OF NON-UNIFORM ROTATION OF SHIP POWER PLANT ELEMENTS DRIVE
Authors: Kochergin Victor I. , Glushkov Sergey P. , Kurmygin Aleksandr V.
Published: December 2020

This article contains the results of studies of the rotation unevenness parameters of the ship power plants elements drive. Theoretical prerequisites of such analysis are described and an example of calculation of parameters of torsional-oscillating system of high-pressure fuel pump drive and speed controller is given in the article. Calculations have shown that at the nominal crankshaft speed of the internal combustion engine, the possibility of resonant oscillations of the camshaft of the fuel pump is not excluded. Design features, faults, violation of adjustments or operating rules can contribute to the operation of elements of power plants at resonant frequencies and cause operational failures. Analysis of rotation unevenness of elements drive and additional equipment of ship's power plants is an appropriate technical measure that allows to increase the reliability of ship's power plants.
THE EFFECTIVE COOPERATION BETWEEN DRIES AND MARINE PORTS AS THE FACTOR OF TRANSPORT MARKET COMPETITIVE ADVANTAGES.
Authors: Troilin Vladimir V. , Arustamov Igor A.
Published: December 2020

Modern forms of management in the transport market, such as dry ports, require new approaches to ensure their cooperation with sea ports, which will eventually affect the inter-port competition of the latter ones. The researched problem was resulted in clear understanding of these relations and influence factors.
ICE PROPULSION ABILITY OF VESSELS WITH NONTRADITIONAL FORM
Authors: Lobanov Vasily A.
Published: December 2020

In article the fact related to the significant increase in structure of the ice category fleet internal and mixed a river sea operation with non-traditional ship hulls forms is stated. With the CAE technologies use such vessels interaction nature with ice cakes and small ice cakes of different thickness and concentration in the ice channel is studied and analyzed. The main attention is paid to a research concerning the influence of different forms bulbous fore ends on change of the vessel ice resistance level. Qualitative features of such bulbous vessels contact with the water ice environment are noted. The statistical analysis concerning the obtained experimental data on the impact assessment related to constructive, dynamic and ice factors on ice propulsion ability of vessels with non-traditional forms is carried out. The quantitative forecast of such influence in the form of the multifactorial regression empirical equation is given.
Radio Activity of Supermassive Black Holes with Extremely High Accretion Rates
Authors: Yang Xiaolong , Yao Su , Yang Jun , Ho Luis C. , An Tao , Wang Ran , Baan Willem A. , Gu Minfeng , Liu Xiang , Yang Xiaofeng , Joshi Ravi
Published: December 2020

Radio emission from the high- and super-Eddington accreting active galactic nuclei (AGNs) has various origins: a persistent jet, the magnetized corona, and the wind-like outflows. It is still unclear which is the leading mechanism responsible for the observed radio emission and how the radio emission is related to other characteristic parameters such as the Eddington ratio and black hole mass. In this paper, we present the 5 GHz Very Large Array (VLA) observational results of a sample of 25 extremely high Eddington accreting supermassive black holes (EESBHs, the Eddington ratio λ
Edd close to or above 1) in narrow-line Seyfert 1 galaxies, among which 22 sources are detected. Most of the EESBHs show a compact radio structure from a few hundred parsecs to 1 kpc scale. We estimated the lowest star formation rate surface density required for producing the observed radio emission and found that it is higher than the largest value previously detected in circumnuclear starburst galaxies, implying that the radio emission is from the AGN activity. Along with a comparison sample, we find an overall inverse

–λ
Edd correlation ranging from sub- to super-Eddington ratios. The high-Eddington and mildly super-Eddington AGNs (−0.5 < log

) have a radio-to-X-ray luminosity ratio L
R/L
X ∼ 10−5–10−4 and a steep radio spectrum, supporting that the radio emission is from transient ejecta (outflows) of corona; however, the jet contribution cannot be entirely ruled out. Our highly super-Eddington sources (log

) have a flatter radio spectrum, along with its low radio luminosity:

; their radio emission is likely dominated by a magnetized corona, and a radiation-pressure-caused jet is also proposed in this paper.
Small-scale Flux Emergence, Coronal Hole Heating, and Flux-tube Expansion: A Hybrid Solar Wind Model
Authors: Wang Y.-M.
Published: December 2020

Extreme-ultraviolet images from the Solar Dynamics Observatory often show loop-like fine structure to be present where no minority-polarity flux is visible in magnetograms, suggesting that the rate of ephemeral region (ER) emergence inside “unipolar” regions has been underestimated. Assuming that this rate is the same inside coronal holes as in the quiet Sun, we show that interchange reconnection between ERs and open field lines gives rise to a solar wind energy flux that exceeds 105 erg cm−2 s−1 and that scales as the field strength at the coronal base, consistent with observations. In addition to providing ohmic heating in the low corona, these reconnection events may be a source of Alfvén waves with periods ranging from the granular timescale of ∼10 minutes to the supergranular/plume timescale of many hours, with some of the longer-period waves being reflected and dissipated in the outer corona. The asymptotic wind speed depends on the radial distribution of the heating, which is largely controlled by the rate of flux-tube expansion. Along the rapidly diverging flux tubes associated with slow wind, heating is concentrated well inside the sonic point (1) because the outward conductive heat-flux density and thus the outer coronal temperatures are reduced, and (2) because the net wave energy flux is dissipated at a rate proportional to the local Alfvén speed. In this “hybrid” solar wind model, reconnection heats the lower corona and drives the mass flux, whereas waves impart energy and momentum to the outflow at greater distances.
Exploiting Network Topology for Accelerated Bayesian Inference of Grain Surface Reaction Networks
Authors: Heyl Johannes , Viti Serena , Holdship Jonathan , Feeney Stephen M.
Published: December 2020

In the study of grain-surface chemistry in the interstellar medium, there exists much uncertainty regarding the reaction mechanisms with few constraints on the abundances of grain-surface molecules. Bayesian inference can be performed to determine the likely reaction rates. In this work, we consider methods for reducing the computational expense of performing Bayesian inference on a reaction network by looking at the geometry of the network. Two methods of exploiting the topology of the reaction network are presented. One involves reducing a reaction network to just the reaction chains with constraints on them. After this, new constraints are added to the reaction network and it is shown that one can separate this new reaction network into subnetworks. The fact that networks can be separated into subnetworks is particularly important for the reaction networks of interstellar complex-organic molecules, whose surface reaction networks may have hundreds of reactions. Both methods allow the maximum-posterior reaction rate to be recovered with minimal bias.
Discovery of a Young Stellar Snake with Two Dissolving Cores in the Solar Neighborhood
Authors: Tian Hai-Jun
Published: December 2020

We report the discovery of a young (only 30–40 Myr) snake-like structure (dubbed a stellar snake) in the solar neighborhood from Gaia DR2. The average distance of this structure is about 310 pc from us. Both the length and width are over 200 pc, but the thickness is only about 80 pc. The snake has one tail and two dissolving cores, which can be clearly distinguished in the 6D phase space. The whole structure includes thousands of members with a total mass of larger than 2000 M
⊙ in a uniform population. The population is so young that it cannot be well explained with the classical theory of tidal tails. We therefore suspect that the snake is hierarchically primordial, rather than the result of dynamically tidal stripping, even if the snake is probably expanding. The coherent 5D phase information and the ages suggest that the snake was probably born in the same environment as the filamentary structure of Beccari et al. If so, the snake could extend the sky region of the Vela OB2 association by a factor of ∼2 and supplement the census of its coeval structures. This finding is useful to understanding the history of the formation and evolution of the Vela OB2 complex. The age of the snake well matches with that of the Gould Belt. In the sky region of our interest, we detect one new open cluster, which is named Tian 1 in this work.
On the Walén Relation for Alfvénic Fluctuations in Interplanetary Space
Authors: Yang Ya-Hui , Chao Jih-Kwin , Lee Lou-Chuang
Published: December 2020

In interplanetary space, the majority of the Alfvénic fluctuations cannot satisfy the Walén relation even though plasma and magnetic field fluctuations are correlated very well. Finding a proper de Hoffman–Teller (HT) wave frame velocity is thus important for characterizing the Alfvénic fluctuations. Recognizing that the Alfvénic fluctuations emanating from different sizes of solar wind streams have their own HT frames, we propose a new scheme called the wave frame with varying velocity (WFVV) method by considering the local averaged HT frame to find a time-varying profile of HT frame velocity. We apply this WFVV method to two Alfvénic events on 2002 October 14 and 17. Unlike the three other schemes discussed in this study, the WFVV method is preferable because it can provide the HT frame variation in more detail, particularly for the large solar wind changes associated with directional discontinuities observed in the October 14 event. For such Alfvénic structures, a time-dependent HT frame derived from the WFVV method, rather than a constant HT frame, produces a better result of the Walén test together with a smaller convection electric field. The difference of estimated HT frame velocities among different schemes was as large as 30 km s−1 for these two events. In addition, we noted that the degree of Alfvénicity tends to decrease with an increasing variance of HT frame velocity, suggesting that a constant HT frame will also give good results for cases of a small variance of HT frame velocity.
What Is the Role of Stellar Radiative Feedback in Setting the Stellar Mass Spectrum?
Authors: Hennebelle Patrick , Commerçon Benoît , Lee Yueh-Ning , Chabrier Gilles
Published: December 2020

In spite of decades of theoretical efforts, the physical origin of the stellar initial mass function (IMF) is still debated. Particularly crucial is the question of what sets the peak of the distribution. To investigate this issue, we perform high-resolution numerical simulations with radiative feedback exploring, in particular, the role of the stellar and accretion luminosities. We also perform simulations with a simple effective equation of state (EOS), and we investigate 1000 solar-mass clumps having, respectively, 0.1 and 0.4 pc of initial radii. We found that most runs, both with radiative transfer or an EOS, present similar mass spectra with a peak broadly located around 0.3–0.5 M
⊙ and a power-law-like mass distribution at higher masses. However, when accretion luminosity is accounted for, the resulting mass spectrum of the most compact clump tends to be moderately top-heavy. The effect remains limited for the less compact one, which overall remains colder. Our results support the idea that rather than the radiative stellar feedback, this is the transition from the isothermal to the adiabatic regime, which occurs at a gas density of about 1010 cm−3, that is responsible for setting the peak of the IMF. This stems from (i) the fact that extremely compact clumps for which the accretion luminosity has a significant influence are very rare and (ii) the luminosity problem, which indicates that the effective accretion luminosity is likely weaker than expected.
The Electron Acoustic Wave and Its Role in Solar Flaring Loops Heating
Authors: Chen L. , Wu D. J. , Xiang L. , Shi C. , Ma B. , Tang J. F. , Huang J.
Published: December 2020

From soft X-ray emission, the solar flare temperatures are from several MK to dozens of times MK, which are higher than the preflare coronal temperatures. A combination of several heating mechanisms may contribute to the heating problem in solar flare loops. In this paper, we propose an important mechanism of solar flaring loops heating, in which the excited electron acoustic wave (EAW) by flare-accelerated fast electron beams can lead to electron heating via collisionless Landau damping effect produced by wave–particle resonant interaction. Taking account of the return-current effect of fast electron beams, by use of numerical and analytic solutions, the plasma wave instability driven by fast electron beams is investigated in typical solar flare loop plasma parameters. The results show that the EAW is the strongest unstable wave mode rather than other wave modes. The dissipation of EAW via collisionless Landau damping and its application to solar flaring loops heating are discussed in detail.
Modeling of the Effects of Stellar Feedback during Star Cluster Formation Using a Hybrid Gas and N-Body Method
Authors: Wall Joshua E. , Low Mordecai-Mark Mac , McMillan Stephen L. W. , Klessen Ralf S. , Zwart Simon Portegies , Pellegrino Andrew
Published: December 2020

Understanding the formation of stellar clusters requires following the interplay between gas and newly formed stars accurately. We therefore couple the magnetohydrodynamics code FLASH to the N-body code ph4 and the stellar evolution code SeBa using the Astrophysical Multipurpose Software Environment (AMUSE) to model stellar dynamics, evolution, and collisional N-body dynamics and the formation of binary and higher-order multiple systems, while implementing stellar feedback in the form of radiation, stellar winds, and supernovae in FLASH. We here describe the algorithms used for each of these processes. We denote this integrated package Torch. We then use this novel numerical method to simulate the formation and early evolution of several examples of open clusters of ∼1000 stars formed from clouds with a mass range of 103
M
⊙ to 105
M
⊙. Analyzing the effects of stellar feedback on the gas and stars of the natal clusters, we find that in these examples, the stellar clusters are resilient to disruption, even in the presence of intense feedback. This can even slightly increase the amount of dense, Jeans unstable gas by sweeping up shells; thus, a stellar wind strong enough to trap its own H ii region shows modest triggering of star formation. Our clusters are born moderately mass segregated, an effect enhanced by feedback, and retained after the ejection of their natal gas, in agreement with observations.
Forward Modeling of Double Neutron Stars: Insights from Highly Offset Short Gamma-Ray Bursts
Authors: Zevin Michael , Kelley Luke Zoltan , Nugent Anya , Fong Wen-fai , Berry Christopher P. L. , Kalogera Vicky
Published: December 2020

We present a detailed analysis of two well-localized, highly offset short gamma-ray bursts—GRB 070809 and GRB 090515—investigating the kinematic evolution of their progenitors from compact object formation until merger. Calibrating to observations of their most probable host galaxies, we construct semi-analytic galactic models that account for star formation history and galaxy growth over time. We pair detailed kinematic evolution with compact binary population modeling to infer viable post-supernova velocities and inspiral times. By populating binary tracers according to the star formation history of the host and kinematically evolving their post-supernova trajectories through the time-dependent galactic potential, we find that systems matching the observed offsets of the bursts require post-supernova systemic velocities of hundreds of kilometers per second. Marginalizing over uncertainties in the stellar mass–halo mass relation, we find that the second-born neutron star in the GRB 070809 and GRB 090515 progenitor systems received a natal kick of

at the

and

credible levels, respectively. Applying our analysis to the full catalog of localized short gamma-ray bursts will provide unique constraints on their progenitors and help unravel the selection effects inherent to observing transients that are highly offset with respect to their hosts.
Observations of Outward-propagating and Mirroring of the Same Energetic Electrons by Wind
Authors: Li G. , Wu X. , Zhao L. , Yao S.
Published: December 2020

We report an energetic electron event observed by the Wind spacecraft in which electrons were first detected to propagate away from the Sun, and subsequently detected to propagate back toward the Sun. Using the recently developed fractional velocity dispersion analysis (FVDA), the path lengths corresponding to these two sequential electron signals were found to be ∼1.5 and ∼3.1 au. The inferred release times for both populations were found to be the same, within uncertainty. No bidirectional halo electrons were identified during the event, indicating that the electrons were not propagating within a closed magnetic field configuration (e.g., a magnetic flux rope). These observations suggest that the same energetic electrons were observed twice at 1 au, with the second time being due to reflection occurring beyond 1 au, by perhaps magnetic kinks caused by a coronal mass ejection–driven shock.
Hidden biodiversity of Amazonian white-sand ecosystems: two distinctive new species of Utricularia (Lentibulariaceae) from Pará, Brazil
Authors: Gonella Paulo Minatel , Barbosa-Silva Rafael Gomes , Fleischmann Andreas S. , Zappi Daniela C. , Baleeiro Paulo Cesar , Andrino Caroline Oliveira
Published: December 2020

As deforestation and fire move forward over pristine vegetation in the Amazon, many species remain undiscovered and may be threatened with extinction before being described. Here, we describe two new species ofUtricularia(Lentibulariaceae) collected during recent fieldwork in an area of white-sand vegetation in the eastern Amazon Basin named Campos do Ariramba. Further herbarium revision revealed that both species were first collected over 60 years ago in the same area, remaining unnamed until now. The new species, namedU. arirambasp. nov.andU. jaramacarusp. nov., are placed in U. sect. Aranella and U. sect. Setiscapella, respectively. We provide full descriptions, illustrations, photographs, a distribution map, and taxonomic discussion for both species. Additionally, we provide a preliminary list of Lentibulariaceae from the Campos do Ariramba. Both new species are assessed as Vulnerable, however, yet known only from a few collections each, highlighting the urgency and importance of fieldwork and taxonomic revisions in the Amazon biogeographic region in order to provide essential data for the conservation of both known and still unknown biodiversity.
Revisiting the taxonomy of the Neotropical Haemodoraceae (Commelinales)
Authors: Pellegrini Marco O. O. , Hickman Ellen J. , Guttiérrez Jorge E. , Smith Rhian J. , Hopper Stephen D.
Published: December 2020

Based on extensive herbarium, field, botanical illustration, and molecular phylogenetic research, five genera and eight species are recognised for the Neotropical Haemodoraceae. New taxa includeCubaniculaHopper et al.,Xiphidium pontederiiflorumM.Pell. et al. andSchiekia timidaM.Pell. et al. Two new combinations are made,Cubanicula xanthorrhizos(C.Wright ex Griseb.) Hopper et al. andSchiekia silvestris(Maas & Stoel) Hopper et al. We also correct the author citation forXiphidium, provide the necessary typifications for several names and present an updated identification key, comments, and photo plates for all species. Finally, we provide high-quality illustrations for most of the recognised species and their diagnostic characters.
Diversité des trajectoires individuelles sur le long terme : apport des analyses longitudinales en général et de l’analyse de séquence en particulier
Authors: Gauthier Jacques-Antoine
Published: December 2020

Le concept de trajectoire de vie individuelle, central aux sciences sociales, est rarement utilisé en tant que tel dans la recherche quantitative. Pourtant, il peut être efficacement opérationnalisé à l’aide de l’analyse de séquence. Cette méthode holistique utilise des données longitudinales pour associer à chaque individu d’une population une séquence chronologique d’états dans un (ou plusieurs) domaine(s) de vie. Comparer ces séquences permet de les regrouper en types sociologiquement significatifs et de les analyser à l’aide de procédures statistiques standard. L’étude des variations de ces trajectoires individuelles en fonction de leur position dans l’espace social et dans le temps historique apporte un éclairage original sur les hypothèses de sexuation, de standardisation et d’individualisation des parcours de vie.
Genre et inégalités de trajectoires sur le marché du travail
Authors: Erhel Christine
Published: December 2020

L’analyse des inégalités de genre au cours du cycle de vie montre la persistance de différentiels de taux d’emploi, mais aussi de durée du travail, entre les femmes et les hommes. Ces écarts sont accentués par les événements familiaux, en particulier la naissance des enfants. L’hétérogénéité entre les pays demeure forte, en lien avec des institutions du marché du travail et des politiques familiales différentes. Les politiques de garde d’enfants apparaissent comme un outil privilégié pour lutter contre ces inégalités, même s’il convient également de prendre en compte les politiques de temps de travail ou de formation professionnelle.
La portabilité des droits sociaux. Enjeux et perspectives juridiques
Authors: Caillaud Pascal
Published: December 2020

Depuis un peu plus d’une décennie, la notion de portabilité des droits sociaux se développe au sein du droit du travail et de la protection sociale, en droit européen comme national. Fondée sur l’idée de conservation de ces droits sociaux malgré de possibles transitions professionnelles subies ou choisies, la portabilité implique un rattachement de ces droits à la personne qui en est titulaire, les détachant du statut professionnel qui avait permis à celle-ci de les acquérir. Les timides prémices de cette portabilité en France, actuellement limitée aux complémentaires santé et à la formation professionnelle, soulèvent des questions à propos de la liberté d’user de ces droits comme de la solidarité quant à leur provision.
La branche Famille lance son premier « parcours usager » : l’accompagnement des séparations familiales
Authors: Hourcade Lucie , Place Aurélien
Published: December 2020

Le développement de démarches dites de « parcours usagers » est un enjeu majeur de la convention d’objectifs et de gestion (COG) signée entre la branche Famille de la Sécurité sociale et l’État pour la période 2018-2022. Leur objectif est de renforcer l’accès aux droits des allocataires et de favoriser la mise en œuvre d’un accompagnement global de leur situation à certains moments clés de leur vie : naissance, séparation, etc. Les ruptures familiales, de plus en plus fréquentes, sont des événements de vie identifiés comme prioritaires en raison de l’importance de leurs impacts sociaux et suscitent la préoccupation des pouvoirs publics comme de la société. Pour favoriser la prévention des séparations et l’accompagnement des parents pendant ces périodes, la Branche a conçu un premier parcours, « parcours séparation », qui articule des offres de service spécifiques dont l’agence de recouvrement des pensions alimentaires (Aripa). L’expérimentation du « parcours séparation », menée pendant huit mois en 2019 dans six Caf réparties sur le territoire national, doit permettre de tester et mesurer au sein des Caisses la plus-value de démarche et l’efficacité des outils mis en place pour accompagner les familles en situation de séparation.
Un laboratoire de la didactique du français langue étrangère : la méthode directe à l’épreuve de l’altérité (1880-1900)
Authors: Spaëth Valérie
Published: December 2020

L’article propose au lecteur d’entrer dans le laboratoire de la didactique du FLE, entre 1880 et 1900, au moment où s’élabore, s’expérimente et se discute une nouvelle méthodologie d’enseignement des langues : la méthode directe. Elle est au centre d’un mouvement général de réforme entre innovations scientifiques, projets politiques et horizons éducatifs nationaux et internationaux. Elle va soutenir le projet scolaire républicain de francisation, réorienter l’enseignement du français aux étrangers et structurer l’école et la pédagogie coloniales. Le corpus étudié, choisi parmi l’abondante littérature pédagogique de l’époque, met en lumière la façon dont les linguistes et les pédagogues, travaillent la relation langue maternelle / langue d’enseignement, au centre de laquelle l’altérité tient la place d’une variable idéologique déterminante.
Long term treadmill exercise affects age-related oxidative stress in the spinal cord of rats
Authors: Shokouhi G. , Ahmadiasl N. , Roshangar L. , Ghorbanihaghjo A. , Sheikhzadeh F. , Mesgari M. , Kosari-Nasab M.
Published: December 2020

Age-induced apoptosis is believed to be caused by the imbalance between production of reactive oxygen species (ROS) and human body antioxidant defence. Regular aerobic treadmill-exercise has been suggested to enhance the antioxidant defence. This study aimed to investigate the effects of long-term treadmill exercise on age-related oxidative stress and the apoptosis of oligodendrocytes in the spinal cord of the rat. Sixty male rats were divided into six groups: three exercised groups, which underwent 6, 9 and 12 months of mild-to-moderate treadmill exercise and three non-exercised control groups. Spinal cord white or grey matter tissue sampling was done through mid-thoracic laminectomy. The malondialdehyde (MDA; indicator of oxidative stress) levels, the number of apoptotic oligodendrocytes and ultrastructural alterations were also evaluated. Our data showed that treadmill exercise resulted in decreased lipid peroxidation and the number of apoptotic oligodendrocytes in the spinal cord of rats, as compared to non-exercised animals. These results were confirmed by TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labelling) staining and electron microscope. This study suggests that the long-term treadmill exercise can affect oxidative stress and oligodendrocytes apoptosis in the spinal cord of aged rats and further studies are needed to validate these findings in humans.
Awareness, handling and storage factors associated with aflatoxin contamination in spices marketed in Dar es Salaam, Tanzania
Authors: Fundikira S.S. , De Saeger S. , Kimanya M.E. , Mugula J.K.
Published: December 2020

A structured questionnaire was used to collect information of awareness, knowledge and practices associated with aflatoxin contamination in spices from 30 retailers in Dar es Salaam. Aflatoxin contamination in spices was analysed using high performance liquid chromatography (HPLC) with fluorescence detection using post column derivatization. Data were statistically analysed to assess factors associated with aflatoxin contamination in the study community. 58% of the spice samples were contaminated and the mean of total aflatoxin level in ginger, cinnamon, cloves and cardamom was 2.67, 2.88, 2.79 and 2.26 μg/kg, respectively. Significant majorities (96.7%) of the respondents were not aware of aflatoxin contamination of spices during storage and its effect on health. Farmers as source where spices were procured and storage time of more than 14 days showed significant association with aflatoxin contamination with odds ratio (OR) = 0.178, 95% confidence interval (CI) = 0.061-0.525,P=0.002 and OR=3.608, 95% CI=1.099-11.845,P=0.034, respectively. This is the first report of aflatoxin contamination in spices consumed in Tanzania. The levels of contamination are high and associated spices that was procured from farmers and long storage time. This calls for urgent raising of awareness and knowledge on good management practices for prevention of aflatoxin contamination of spices in Tanzania.
Modalités d’accès et public des milieux d’accueil francophones de la petite enfance en Région de Bruxelles-Capitale
Authors: Humblet Perrine , Robert Emmanuelle , Huynen Philippe , Amerijckx Gaëlle , Aujean Stéphane , Wayens Benjamin
Published: December 2020

Cette fact sheet reprend les principaux résultats d’une enquête réalisée auprès de milieux d’accueil de la petite enfance francophones à Bruxelles entre les mois de juillet et d’octobre 2018. Elle aborde successivement les modalités et critères d’inscription, l’organisation de l’entrée et des premiers jours d’accueil, les caractéristiques du public et la contribution financière des parents.