bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flight kinematics of the barn swallow (Hirundo rustica) over a wide range of speeds in a wind tunnel
Authors: Park Kirsty J. , Rosén Mikael , Hedenström Anders 
Published: April 2021

SUMMARYTwo barn swallows (Hirundo rustica) flying in the Lund wind tunnel were filmed using synchronised high-speed cameras to obtain posterior, ventral and lateral views of the birds in horizontal flapping flight. We investigated wingbeat kinematics, body tilt angle, tail spread and angle of attack at speeds of 4–14ms−1. Wingbeat frequency showed a clear U-shaped relationship with air speed with minima at 8.9ms−1(bird 1) and 8.7ms−1 (bird 2). A method previously used by other authors of estimating the body drag coefficient (CD,par) by obtaining agreement between the calculated minimum power (Vmin) and the observed minimum wingbeat frequency does not appear to be valid in this species, possibly due to upstroke pauses that occur at intermediate and high speeds, causing the apparent wingbeat frequency to be lower. These upstroke pauses represent flap-gliding, which is possibly a way of adjusting the force generated to the requirements at medium and high speeds, similar to the flap-bound mode of flight in other species. Body tilt angle, tail spread and angle of attack all increase with decreasing speed, thereby providing an additional lift surface and suggesting an important aerodynamic function for the tail at low speeds in forward flight. Results from this study indicate the high plasticity in the wingbeat kinematics and use of the tail that birds have available to them in order to adjust the lift and power output required for flight.
TEMPERATURE AND MYOGENIC FACTOR TRANSCRIPT LEVELS DURING EARLY DEVELOPMENT DETERMINES MUSCLE GROWTH POTENTIAL IN RAINBOW TROUT(ONCORHYNCHUS MYKISS) AND SEA BASS (DICENTRARCHUS LABRAX)
Authors: WILKES D. , XIE S. Q. , STICKLAND N. C. , ALAMI-DURANTE H. , KENTOURI M. , STERIOTI A. , KOUMOUNDOUROS G. , FAUCONNEAU B. , GOLDSPINK G. 
Published: April 2021

SUMMARYThe influence of changes in environmental temperature on the mRNA levels of myogenic regulatory factors (MRFs), i.e. MyoD and myogenin, as well as myosin heavy chain (MyHC) were studied during early larval development in rainbow trout and sea bass. Phosphoimager analysis of northern blots indicated that there is an optimum temperature for the RNA transcript levels of MRF and MyHC RNA in trout and in sea bass larvae. In the trout strain studied, the highest concentration for MRF and MyHC transcripts was found at 8°C rather than 4°C or 20°C. In European sea bass, the highest concentrations of MRF and MyHC mRNA were observed at 15-20°C rather than 13°C. Raising sea bass larvae at 15°C was associated with higher MyHC gene expression as well as a trend towards an increase in total muscle fibre number and higher growth rates after transfer at ambient temperature. Results suggest that mRNA levels of MRF and MyHC can be used to optimise early development. An experiment in which the temperature was changed illustrates the consequence of precise temporal expression of MRF genes in specifying muscle fibre number at critical stages during early development.
EFFECTS OF DURATION AND TIME OF FOOD AVAILABILITY ON PHOTOPERIODIC RESPONSES IN THE MIGRATORY MALE BLACKHEADED BUNTING (EMBERIZA MELANOCEPHALA)
Authors: KUMAR VINOD , SINGH SUDHI , MISRA MANJU , MALIK SHALIE 
Published: April 2021

SUMMARY
The effects of the duration and time of food availability on stimulation of the photoperiodic responses (fattening and gain in body mass, and growth and development of testes) were investigated in the migratory blackheaded bunting(Emberiza melanocephala). Two experiments were performed. Experiment 1 examined the effects of a reduction in the duration of food supply in buntings that were subjected to long day lengths (16 h:8 h L:D) and received food ad libitum (group I) or for restricted durations, coinciding with the end of the lights-on period, of 8 h (group II) and 4 h (group III). Buntings of group I gained in body mass, whereas there was a mixed response in group II (half the birds gained and half lost body mass), and all birds of group III lost body mass. There was no effect on testis growth in groups I and II, but testes grew more slowly in group III. Experiment 2 investigated the effects of both the duration and the time of food availability. Of five groups of birds, group I was exposed to an 8 h:16 h L:D photoperiod, and groups II-V were exposed to 16 h:8 h L:D. Whereas birds of groups I and II received food ad libitum, those of groups III-V were fed only for 5 h, at zt 0-5(group III), zt 5.5-10.5 (group IV) or zt 11-16 (group V), where zt =zeitgeber time and zt 0 refers to the beginning of the lights-on period. Apart from duration, the timing of food availability also had an effect on photoperiodic stimulation under the 16 h:8 h L:D photoperiod. Birds that were fed ad libitum fattened and gained in body mass, whereas among restricted feeding groups, only birds in the group fed during the first 5 h(zt 0-5, group III) showed a significant increase in body mass (albeit considerably lower than in the ad libitum group). Birds fed during the middle 5 h (zt 5.5-10.5, group IV) showed an intermediate response, and those fed during the last 5 h (zt 11-16, group V) lost body mass. Testicular growth was suppressed in birds that were fed for 5 h in the evening, but not in those fed for the same period in the morning or in the middle of the long day. Taken together, these results show that the duration of food supply and/or the time of day at which food is available affect photoperiodic stimulation of fattening and gain in body mass as well as the growth and development of gonads in the blackheaded bunting.
Mechanisms of helical swimming: asymmetries in the morphology, movement and mechanics of larvae of the ascidianDistaplia occidentalis
Authors: McHenry Matthew J. 
Published: April 2021

SUMMARYA great diversity of unicellular and invertebrate organisms swim along a helical path, but it is not well understood how asymmetries in the body shape or the movement of propulsive structures affect a swimmer’s ability to perform the body rotation necessary to move helically. The present study found no significant asymmetries in the body shape of ascidian larvae (Distaplia occidentalis) that could operate to rotate the body during swimming. By recording the three-dimensional movement of free-swimming larvae, it was found that the tail possessed two bends, each with constant curvature along their length. As these bends traveled posteriorly, the amplitude of curvature changes was significantly greater in the concave-left direction than in the concave-right direction. In addition to this asymmetry, the tail oscillated at an oblique angle to the midline of the trunk. These asymmetries generated a yawing moment that rotated the body in the counterclockwise direction from a dorsal view, according to calculations from hydrodynamic theory. The tails of resting larvae were bent in the concave-left direction with a curvature statistically indistinguishable from the median value for tail curvature during swimming. The flexural stiffness of the tails of larvae, measured in three-point bending, may be great enough to allow the resting curvature of the tail to have an effect on the symmetry of kinematics. This work suggests that asymmetrical tail motion is an important mechanism for generating a yawing moment during swimming in ascidian larvae and that these asymmetries may be caused by the tail’s bent shape. Since helical motion requires that moments also be generated in the pitching or rolling directions, other mechanisms are required to explain fully how ascidian larvae generate and control helical swimming.
Molecular cloning and characterisation of a novel membrane receptor gene from the lobster Jasus edwardsii
Authors: Khoo Jenny Gaik Imm , Sin Frank Y. T. 
Published: April 2021

SUMMARY
The eyestalk of the lobster, Jasus edwardsii, is an important source for hormones involved in the regulation of growth and reproduction. How these hormones transfer their messages to the cell and nucleus is not known. This paper describes the cloning, characterization and expression analyses of two genes that code for two membrane-associated peptides that may be involved in signal transduction. These genes, peJK2 and peJK3, were isolated from a cDNA library derived from lobster eyestalk mRNAs. The two clones shared 96.6 % sequence homology, and code for putative proteins of 110 and 113 amino acids, respectively. These were likely to be two allelic forms of the same gene. Northern blot analysis using these clones as probes detected the same mRNA from eyestalk, muscle and epithelial extracts, but with greater intensity in the eyestalk extract. In situ hybridisation also indicated the predominant expression of these genes in the eyestalk. Analysis of the putative protein sequences showed that they contained two transmembrane (TM) helices, a short amino acid sequence sharing high homology with the G-protein-coupled receptor (GPCR) motif in the second TM, a signal sequence between the TMs, and a protein kinase phosphorylation site at the C termini. Sequence analyses therefore suggested that the deduced peptides may function in signal transduction.
Comparison of rural practice in relation to upper gastrointestinal endoscopy
Authors: Kotani Kazuhiko 
Published: April 2021

doi: https://doi.org/10.12669/pjms.37.4.4397
How to cite this:Kotani K. Comparison of rural practice in relation to upper gastrointestinal endoscopy. Pak J Med Sci. 2021;37(4):1244-1245. doi: https://doi.org/10.12669/pjms.37.4.4397
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Stabilność systemu międzynarodowego – wybrane ujęcia i problemy
Authors: Krzyżanowska-Skowronek Iwona 
Published: April 2021

Stability of the International System – Selected Issues and Approaches
Classical theoretical concepts offer many possibilities for study the issue of stability of the international system. Therefore, the article presents a brief analysis of the development of this research, but focuses only on selected theoretical models. Despite the constant creation of new concepts and attempts to formalize research on this question, it was not possible to develop common solutions or conclusions. Numerous cognitive problems either resulted from the preliminary assumptions or were a consequence of using simplified research models. That is why theorists, while analyzing the same problems connected with achieving stability at the level of the international system, so often came to different or even opposite conclusions. The aim of this article is to show the diversity of research on stability of the international system, to present some achievements and to try to diagnose the main problems of the discussed theoretical concepts.
Early-Middle Frasnian (Late Devonian) carbon isotope Event in the Timan-Pechora Basin (Chernyshev Swell, Pymvashor River section, North Cis-Urals, Russia)
Authors: Kotik Ivan S. , Zhuravlev Andrey V. , Maydl Tatyana V. , Bushnev Dmitry A. , Smoleva Irina V. 
Published: April 2021

Details of the Early-Middle Frasnian boundary interval of the Pymvashor River section (Timan-Pechora Basin, Cis-Urals, in the far north of European Russia) are revealed by biostratigraphically constrained carbonate (δ13Ccarb) and organic carbon (δ13Corg) stable data. The studied interval corresponds to the lower part of the Domanik Formation, which consists of interbedded limestone and shale beds. Organic-rich black shale that lacks bioturbation and benthic organisms indicates an oxygen-depleted depositional environment. Detection of isorenieratene derivatives in organic matter indicates that anoxia was present in the photic zone during deposition. The Pymvashor River section contains δ13Ccarb and δ13Corg isotope records related to the Early-Middle Frasnian isotope Event. The similarity between the Cis-Uralian (this study) and the Chinese δ13Ccarb and δ13Corg oscillations, including the twostep pattern of the recorded major positive excursions, suggests a robust correlation of the Late Devonian Early- Middle Frasnian isotope Event and minor intra-event excursions. Magnitude of variations and values of δ13Corg and δ13Ccarb in the punctata Zone in the Pymvashor River section are minor than those observed in the North American, Polish, and Chinese successions. Such difference may reflect specific variation of the local environments.
Environmental Taxes and Economic Growth with Multiple Growth Engines
Authors: Beladi Hamid , Chen Ping-ho , Chu Hsun , Hu Mei-ying , Lai Ching-chong 
Published: April 2021

Abstract
We develop an endogenous growth model in which long-run growth is driven by three engines: private abatement R&D, expanding-variety R&D, and capital accumulation. We show that an environmental tax activates private abatement by directing researchers from the variety R&D sector to the abatement R&D sector, which helps the economy avoid the environmental disaster. Our results also show that the effect of the environmental tax on long-run growth is uncertain, depending mainly on the relative productivity between the two R&D sectors. If the abatement R&D sector is sufficiently productive, increasing the environmental tax will enhance the balanced output growth rate and social welfare.
Icons as punishers. Two narrations from the Vaticanus gr. 1587 manuscript (BHG 1390 f)
Authors: Alexaki Marirena 
Published: April 2021

Abstract
The Iconoclastic controversies of the Byzantine Era have provided a rich literary tradition of miracle narrations regarding the various magical aspects of the icon. The second period of Iconoclasm however seems to have given rise to a lesser prominent motif of the earlier traditions, namely that of the icon-agent acting as active punisher against its transgressor. The current article explores the development of this motif after a concise survey of the history of icon-miracle narrations, their representative texts and their role in liturgical practice. The starting point of the study were two previously unedited byzantine texts from the manuscript Vaticanus gr. 1587, testifying unique stories of icons as punishers. Finally, these stories are also perfect examples of the rich historical information popular narrations can provide on a topographical and prosopographical level regarding the era within which they were produced.
Fragments of a steatite icon (diptych wing) with the Great Feasts cycle excavated in Chełm (eastern Poland)
Authors: Buko Andrzej , Dzieńkowski Tomasz , Gołub Stanisław , Kruk Mirosław P. , Michalik Marek , Musin Aleksandr , Rafalska-Łasocha Alicja , Wołoszyn Marcin 
Published: April 2021

Abstract
The paper presents fragments of a Byzantine icon discovered in 2015 during regular archaeological excavations carried out in Chełm, eastern Poland. Iconographic analyses allow the nine surviving fragments to be interpreted as belonging to a diptych wing with the Great Feasts cycle. The icon represents archaic iconography of the subject, with the scene of Transfiguration placed after Entry into Jerusalem and before the Crucifixion. The artefact was created in the second half or at the close of the 12th century, and it was made from steatite, which has been confirmed by petrographic analyses. The icon was discovered in the remains of a palace complex of King Daniel Romanovich, the greatest ruler of the Galicia-Volhynia Lands. The results of the archaeological research allow the terminus ante quem for the icon’s arrival in Chełm to be determined as before the middle of the 13th century. Various possible explanations as to how the icon found its way to Chełm are also explored in the paper.
Prontuario para una abadesa: El Escur. Φ III 11 e Irene Cumno (con una propuesta de la escritura inédita de Mateo Blastares)
Authors: Martínez Manzano Teresa 
Published: April 2021

Abstract
In this paper I firstly examine the contents of Escur. Φ III 11, which includes a medical section, an anthology of texts both sacred and profane, and the epistolar exchange between Gregorius Acindynus and Eirene Choumnos. Secondly I go through Eirene’s intellectual background and the books transcribed under her patronage. Thirdly I explain the role played by this Escurialensis in Eirene’s library and in the anti-Palamite circles. Fourthly, basing on different kinds of arguments, I attribute the copying of ff. 83r-156v to Matthew Blastares.
Composing the Μικρομεγάλη Ἰλιάς
Authors: Mondini Ugo 
Published: April 2021

Abstract
The Μικρομεγάλη Ἰλιάς, the first work written by John Tzetzes, consists of 1.676 hexameters and numerous scholia. It narrates the events of the Trojan war from the conception of Paris to the fall of the city. This paper analyses the poem and its structure. In his later Exegesis to the Iliad, Tzetzes states that the Μικρομεγάλη Ἰλιάς allows to “learn thoroughly, in every detail” the history of the war. Following this evidence, the macro- and the microstructure of the poem are analysed in order to understand how Tzetzes structured his literary work and to what end. The last paragraph deals with the title Μικρομεγάλη Ἰλιάς.
Affordance Derivation Facilitates the Semantic Access in Comprehending Chinese Puns
Authors: Liao Qiaoyun , Hu Quan , Gao Mengting , Meng Lijun , Tan Zhipeng , Zheng Jie 
Published: April 2021

Abstract
The study employed ERP technique to explore whether the affordance derivation can facilitate semantic access in comprehending Chinese puns. ERPs were measured while participants read the pun sentences containing dual meanings and made a judgement about the following probes and statements. The results showed that highly related probes in pun sentences elicited a smaller N400 and a larger LPC than moderately related probes in pun sentences. As for the comparison of sentence types, both highly and moderately related probes in pun sentences produce a smaller N400 and a larger LPC than those in control sentences. These results indicate that in the early stage of pun comprehension, semantic access to the literal meaning is easier through affordance derivation because of meaning dominance and frequency. In the late stage of integration, however, the intended meaning of puns can be facilitated and accessed through its privilege of affordance derivation activated by pun words in a pun context because of the priming context and its underlying intention. The study has discovered empirically that it is the affordance derivation, which connects the context and the dual meanings indicated by the pun words, that contributes to the different time courses and dynamic underlying neurocognitive mechanisms in comprehending puns in Chinese.
Extensive Reading Research in the EFL Classroom of China: A Qualitative Meta-Analysis
Authors: Wang Shuyan , Kim Heyoung 
Published: April 2021

Abstract
Extensive reading has long been applied in the English as a foreign language classroom in China, but the fundamental theories and practical instruction are not satisfactory. The study aims to synthesize and examine extensive reading studies over the past fifty years (1962-2019) from a holistic perspective. By performing a qualitative meta-analysis, a total of 81 articles published in widely accepted journals were carefully coded and analyzed. Three latent problems emerged, including that 1) most extensive reading researchers misunderstand the inherent characteristic of extensive reading (i. e., pleasure reading) and less frequently follow the principles of extensive reading instruction; 2) there are methodological weaknesses in empirical research designs, and; 3) research scope is limited regarding participants and methodology. Suggestions for extensive reading research and instruction are included.
Obstetrical history of a family with combined oxidative phosphorylation deficiency 3 and methylenetetrahydrofolate reductase polymorphisms
Authors: Cagan Murat , Unal Canan , Urel Demir Gizem , Fadiloglu Erdem , Ozgul Riza Koksal , Beksac Mehmet Sinan 
Published: April 2021

Abstract

Objectives
Recurrent pregnancy loss (RPL) is a devastating complication of pregnancy with various etiologic backgrounds.

Case presentation
We present a case of combined oxidative phosphorylation deficiency 3 (COXPD3) carrier pregnant woman with Methylenetetrahydrofolate reductase (MTHFR) polymorphisms. She had five pregnancy losses and a postpartum death due to COXPD3. The patient was admitted to our clinic for the first time at her seventh pregnancy with oocyte donation. The patient was registered in a special antenatal care program and delivered a healthy baby at term. Her eighth pregnancy was terminated due to COXPD3 which was prenatally diagnosed.

Conclusions
Comprehensive and individualized approaches are necessary in RPL cases to obtain optimal outcomes.
Corporate Purpose: A Management Concept and its Implications for Company Law
Authors: Fleischer Holger 
Published: April 2021

Abstract

Many companies have recently been following the so-called corporate purpose concept that is recommended by leading management scholars. To this end, they identify a raison d’être for their enterprise that goes beyond mere profit making and they anchor it in the entire value chain. This paper puts the corporate purpose concept into perspective by linking it to the larger debate on corporate social responsibility and by outlining its theoretical foundations and practical application. It then goes on by explaining how this management concept fits into the company law framework, looking to France and the UK as well as to the US and Germany. Finally, this paper assesses various policy proposals made by leading purpose proponents, ranging from mandatory purpose clauses in the articles of association to say-on-purpose shareholder voting and dual-purpose business organisations.
Circularly polarized array antenna based on dual split ring resonators (DSRRs)
Authors: Kakepoto Ghulam Fatima , Xiao Shaoqiu , Mangi Farman Ali 
Published: April 2021

Abstract
A wideband circularly polarized (CP) array antenna has significant importance in modern communication system. In this paper, we proposed a wide band CP array by combing dual split ring resonators (DSRRs) to dual layer microstrip antenna. A 2 × 2 dual-layer microstrip antenna array is used to radiate wide band linearly polarized wave, and the 3 × 3 four-layer DSRRs is used as an external polarizer which converts linearly polarized wave to circularly polarized wave at distinct frequencies. The proposed array achieves an impedance bandwidth of 20% ranging from 4.57–5.57 GHz and AR bandwidth of 16.83% ranging from 4.57–5.41 GHz. The prominent futures of the proposed array are wide impedance bandwidth on desired frequencies. This new concept is theoretically and experimentally investigated to evaluate the performance of the proposed array, which allows a better prospect for the application of radar and satellite communication systems.
Monitoring and simulating the distribution of phytoplankton in constructed wetlands based on SPOT 6 images
Authors: Song Yumeng , Zhang Jing 
Published: April 2021

Abstract
We integrated hyperspectral and field-measured chlorophyll-a (Chl-a) data from the Kristalbad constructed wetland in the Netherlands. We developed a best-fit band ratio empirical algorithm to generate a distribution map of Chl-a concentration (C
chla) from SPOT 6 imagery. The C
chla retrieved from remote sensing was compared with a water quality model established for a wetland pond system. The retrieved satellite results were combined with a water quality model to simulate and predict the changes in phytoplankton levels. The regression model provides good retrievals for Chl-a. The imagery-derived C
chla performed well in calibrating the simulation results. For each pond, the modeled C
chla showed a range of values similar to the Chl-a data derived from SPOT 6 imagery (10–25 mg m−3). The imagery-derived and prediction model results could be used as the guiding analytical tools to provide information covering an entire study area and to inform policies.