bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low density lipoproteins bound to Schistosoma mansoni do not alter the rapid lateral diffusion or shedding of lipids in the outer surface membrane
Authors: Caulfield John P. , Chiang Chun-Pin , Yacono Patrick W. , Smith Laurel A. , Golan David E. 
Published: April 2021

ABSTRACT
Schistosomula of Schistosoma mansoni bind human low density lipoproteins (LDL) in a concentrationdependent and saturable manner. The bound LDL could provide phospholipids and sterol to the worm, which cannot synthesize sterol de novo and lacks acyl chain-modifying capability. Here we have used three phospholipid analogues to explore the effect of LDL binding on the parasite’s outer tegumental membrane, i.e. the outer of the two membranes that cover its surface syncytium. Fluorescein phosphatidylethanolamine (Fl-PE) and rhodamine phosphatidylethanolamine (Rh-PE) bound to the parasite in a saturable manner and, as shown by fluorescence microscopy, were confined to the surface. Fl-PE fluorescence was completely quenched by Trypan Blue and Fl-PE was lost from the surface following single exponential decay kinetics (tr=l2h), further suggesting that the probe was confined to the outer membrane. 1,1’ -Dioctadecyl-3,3,3’,3’ -tetramethylindocarbocyanine perchlorate (Dil-Cl8(3); Dil) did not bind saturably and was seen in both the surface and the internal parasite membranes. Fluorescence photobleaching recovery was used to measure the lateral mobility of Fl-PE in the outer membrane. The lateral diffusion coefficient of Fl-PE was approximately 10−7cm2s−1. The fractional mobility of Fl-PE was 85 % when measured using a laser beam of radius 1.8 μm and 45% using a beam of radius 4.3 μm. These measurements suggest that the outer membrane is composed of μ-scale liquid crystalline-phase lipid domains that lack significant amounts of transmembrane proteins. LDL binding to the parasite surface did not alter the lateral mobility of Fl-PE or the rate of loss of either Fl-PE or Rh-PE. These studies suggest that the binding of LDL to the outer tegumental membrane of schistosomula does not change either the organization of the membrane lipids or their rate of loss from the membrane. If LDL do provide lipids to schistosomula, then direct insertion of lipid molecules into the outer tegumental membrane is an unlikely mechanism for lipid transfer.
Changes in the activity of alcohol dehydrogenase during the cell cycle of the fission yeast Schizosaccharomyces pombe
Authors: Vicente-Soler J. , Creanor J. , Bisset Y. , Mitchison J. M. 
Published: April 2021

ABSTRACT
The activity of alcohol dehydrogenase (ADHase) was followed in synchronous cultures of Schizosaccharomyces pombe. In selection synchronised cultures of wild-type cells, it followed a linear pattern in which there was a constant rate of increase of activity followed by a doubling of this rate at the end of the cycle. The same pattern was also found in selection synchronised cells of wee mutants except that the point of rate change was shifted to 0.27 of the cycle. A similar linear pattern was also found in the shortened cell cycles produced by induction synchrony (block and release of the mutant cdc2.33) but the rate change point was at about 0.75 of the cycle. In the mutant cdcl3.117, there was a marked fall in the rate of activity increase at 35°C but not at 37°C. In all these situations, the ADHase activity closely paralleled in pattern and in timing the rate of production of CO2 established in earlier papers. This suggests a coordinate control of the flux through glycolysis and the activity of the last enzyme in the glycolytic pathway in yeast However, an interesting difference indicating a loss of the coordinate control occurred in ‘synchronous’ cultures of cdc2.33 in which small cells had been selected but in which the DNA-division cycle had been blocked by a shift-up to the restrictive temperature. Rate changes both in CO2 production and in ADHase activity continued in these blocked synchronous cultures but the timing was different. With ADHase activity the timing was 15 % greater than that in a normal cell cycle whereas with CO2 production it was 15% less. We suggest that these and other periodic events are subject to independent oscillatory controls in these blocked cultures with timings that differ from each other and from the normal cycle but in the normal cycle the oscillators are all entrained by one or more events of the DNA-division cycle.
Double-rowed organization of inner dynein arms in Chlamydomonas flagella revealed by tilt-series thin-section electron microscopy
Authors: Muto Etsuko , Kamiya Ritsu , Tsukita Shoichiro 
Published: April 2021

ABSTRACT
The in situ organization of the inner dynein arms of Chlamydomonas axonemes was investigated by analyzing a number of tilt-series thin-section electron micrographs taken with improved fixation and staining protocols. The use of mutant axonemes lacking the outer dynein arms and the radial spokes enabled us to detect a novel feature: inner-arm projections arranged in two rows. The arrangement of projections within each row was deduced by making a model that fitted both tilt-series longitudinal thin-section images and cross-section images. The model suggested that, within a repeating unit of 96 nm, one of the two rows, positioned more centrifugally, consists of four discrete domains and the other, positioned more centripetally, consists of three pairs of globular structures. Whereas the centripetal row resembles the inner-arm arrangement reported previously, the centrifugal row appears to have been identified for the first time in this study. These findings make necessary the re-examination of the arrangement of various inner-arm subspecies within the axoneme.
Ultrastructure of chromatin I. Negative staining of Isolated fibers
Authors: Woodcock C. L. , Woodcock H. , Horowitz R. A. 
Published: April 2021

ABSTRACT
The ultrastructure of chromatin fibers isolated from erythrocyte nuclei of Necturus maculosus and contrasted with a number of negative stains is described. Long (&gt;lOOOnm) fibers are prepared under ionic conditions that promote fiber integrity, fixed with glutaraldehyde and negatively stained with aurothioglucose, ammonium molybdate, methylamine tungstate, sodium phosphotungstate, uranyl acetate and a uranyl acetate-sodium phosphotungstate sequence. All stains yield images of ‘30 nm’ chromatin fibers, but aurothioglucose gives the most consistent diameter measurements (33 nm, SA). 3.5 nm), and provides the clearest images of individual nucleosomes. Regions of fiber showing structural order are seen with all stains. The most commonly observed is a regular pattern of oblique cross-striations consistent with the visualization of the ‘top’ or bottom’ of a helical structure. There is a significant relationship between fiber diameter and the cross-striation angle, consistent with an extensible chromatin fiber. Examination of power spectra prepared from selected ordered regions confirms the visual impressions, and indicates a striation spacing ranging from llnm to 18 nm, and dependent on the stain type. Fibers allowed to unfold slightly in a buffer containing 50 mM monovalent ions show evidence of a two-stranded helix-like organization. These results are discussed in terms of current models for the structure of the chromatin fiber.
On Methods for Preparing the Organ of Corti for Microscopical Investigation
Authors: Moseley Henry N. 
Published: April 2021

ABSTRACT
In the January number (1872) of the ‘Quarterly Journal of Microscopical Science,’ Dr. Rutherford makes the somewhat startling statement that the whole of histology can be gone over with a class of students in twenty-four lessons; and certainly his list of tissues to be examined in the course is tolerably comprehensive. A method for observing the structure of the retina is given ; but the Schneiderian membrane. the organ of taste, and Corti’s organ, are omitted entirely. Surely this latter, at least, is of as great importance and interest as the retina. It is generally, I imagine, considered very difficult to demonstrate j and such is, as far as regards the finer relations and structure of its several components, undoubtedly the case, and in these particulars it is one of the most difficult of histological problems; but a great deal can be seen with comparative ease, and, as I have had considerable experience in the matter, I propose here to give some notes on the subject. I-do not consider them to be by any means exhaustive or novel; but I have always found microscopists very anxious to see preparations of Corti’s organ, and very commonly unacquainted with the methods by which they may be obtained, and anxious to be informed concerning them.
The Structure of Xenia Hicksoni, nov. sp., with some Observations on Heteroxenia Elijzabethæ, Kölliker
Authors: Ashworth J. H. 
Published: April 2021

ABSTRACT
At the suggestion of Professor Hickson I undertook to examine a specimen of the Alcyonaceous coral Xenia, which he had collected on the reefs of Talisse Island, North Celebes, chiefly with the intention of working out the arrangement of the canals of the colony. As the investigation proceeded the preservation of the colony was found to be so exceptionally perfect that it seemed desirable to make a study of its histology, and as several new and interesting points were early observed I finally decided to work out in detail the complete anatomy and histology of the colony. Although many authors have described the external characters of various species of Xenia, few have paid any attention to their internal structure. Bourne (1895) has referred to the canal system, the mesoglœa, and the distribution of spicules in two species of Xenia, and in Heteroxenia Elizabethæ, and Kölliker (1874) described the anatomy of his new Heteroxenia Elizabethæ as far as its very imperfect preservation would permit. These two accounts contain practically the whole of our knowledge of the internal structure of these two genera, and hence, when the beautiful preservation of this colony of Xenia from Talisse was apparent, there was a strong inducement to attempt a more complete account of its detailed anatomy and histology.
The Development of Echinoids: Part I.—The Larvae of Echinus miliaris and Echinus esculentus
Authors: Macbride E. W. 
Published: April 2021

ABSTRACT
The development of Echinoids is up till the present very imperfectly known, our information on the subject being in a most unsatisfactory condition. The foundation was laid by Johannes Müller (3), but although he observed and described the external features of the metamorphoses, he was unable to refer with any certainty any one of the larval forms which he described to the adult species from which it was derived. So far as I am aware, Prof. Théel (4) and H. Bury (1) are the only persons who have hitherto reared any species from the egg until the conclusion of the metamorphosis. Through the researches of the former we have obtained an accurate knowledge of the characters of the larva of Echinocyamus pusillus at all stages of its growth. The youngest larval forms of many species have been determined by rearing, nevertheless Mortensen (2), in his most valuable summary of all descriptions yet published of Echinoid larvae, points out that our knowledge of the later pluteus stages is most imperfect, and that it is not possible to assign the older plutei which have been described to the species from which they have been derived.
The Relative Oxidizing Properties of Certain Reagents and Mixtures used for the Fixation of Tissues
Authors: Casselman W. G. Bruce 
Published: April 2021

ABSTRACT
The oxidation potentials of the fixing reagents studied range from rioV for chromic acid to 0-23 V for formaldehyde. Potassium dichromate, mercuric chloride, and osmium tetroxide have intermediate values. Commonly used mixtures prepared from these compounds also exhibit a range of potentials from i-oo V for Champy’s to 0-15 V for Regaud’s. The oxidation potentials of Altmann’s, Champy’s, Flemming’s, Helly’s, and Zenker’s fluids remain relatively constant for at least 1 day, whereas those of Regaud’s and Sanfelice’s fluids undergo appreciable change.
The Continuity between the Cavities of the Premandibular Somites and of Rathke’s Pocket in Torpedo
Authors: de Beer Sir Gavin 
Published: April 2021

ABSTRACT
The existence of an open communication between the cavity of Rathke’s pocket and the cavity of the premandibular somite in Torpedo ocellata at the 7 mm. stage is demonstrated by means of microphotographs. They provide a complete refutation of the claim by B. Wedin that because he was unable to find continuity of open communication between the cavities of Rathke’s pocket and of the premandibular somite, therefore E. S. Goodrich was mistaken in homologizing the preoral pit of Amphioxus with the hypophysis of craniates. On the contrary, Goodrich’s observations are confirmed and his theory vindicated.
Impromptu Speaking Skills of Pre-service Teachers
Authors: Aktay Emel Guvey 
Published: April 2021

<p style="text-align:justify">The purpose of the study is to examine pre-service teachers' impromptu speaking skills on the basis of the evaluations of the instructor, peers and their own. The study employed a descriptive case study design, one of the qualitative research methods. A total of 23 pre-service math teachers taking the course of Art of Effective Speech in a state university in Turkey in the 2016-2017 academic year participated in the study. The data of the study were collected through the observations of the researcher and pre-service teachers. Descriptive analysis was used in the analysis of the data. As a result of the study, it was found that in most of the observation items, the pre-service teachers found themselves inadequate in terms of impromptu speaking skills while they were found to be adequate by their peers and instructor. In addition, it was revealed that the pre-service teachers found themselves inadequate in some items related to the use of voice while they found themselves adequate in most of the items related to articulation/diction and body language and in all of the items related to communication. However, while the instructor observed that the pre-service teachers were generally competent in all the sub-dimensions, she determined that they needed improvement in the sub-dimensions of eye contact, pausing at the appropriate place and speaking without repeating words. </p>
Effects of prenatal exposure factors on birth outcomes through mediation of favorable fetal growth conditions using structural equation modeling
Authors: Mitku Aweke A. , Zewotir Temesgen , North Delia , Jeena Prakash , Naidoo Rajen N. 
Published: April 2021

Background
Birth weight, birth length, and gestational age are major indicators of newborn health. Several prenatal exposure factors influence the fetal environment. The aim of the study was to investigate the effect of prenatal exposure factors, including socio-demographic, behavioural, dietary, physical activity, clinical and environmental on birth outcomes through the mediation of Favourable Fetal Growth Conditions (FFGC).

Methods
Data was obtained from six hundred and fifty-six Mother and Child in the Environment birth cohort study in Durban, South Africa from 2013 to 2017. We adopted structural equation models which evaluate the direct and indirect effects by allowing multiple simultaneous equations to incorporate confounding and mediation.

Results
A significant direct and indirect effect of FFGC on newborn weight, length, and gestational age was seen. Gestational weight gain and maternal body mass index in the first trimester exerted a mediation effect between maternal behavioural risk factors and FFGC. Similarly, the level of physical activity during pregnancy was associated with decreased gestational weight gain. The effects of maternal characteristics on newborn weight, length, and gestational age were largely indirect, operating through FFGC as a latent variable.

Conclusions
Gestational weight gain and maternal pre-gestational BMI were observed to mediate the association between prenatal behavioural risk factors and favourable fetal growth conditions.

Trial registration
Retrospectively registered from 01 March 2013.
Designing internet-enabled patient education for self-management of T2D diabetes—The case of the Razavi-Khorasan province in Iran
Authors: Jafari Javad , Karlgren Klas , Moonaghi Hossein Karimi , Layegh Parvin , Bonacina Stefano , Masiello Italo 
Published: April 2021

Background
The number of people with diabetes is estimated to increase to 642 million by 2040, with most having type 2 diabetes. Patients with diabetes require continuous monitoring and possible treatment changes. Patient education is the process of enabling individuals to make informed decisions about their personal health-related behaviours and internet-enabled interventions have the potential to provide support and information to patients with diabetes.

Objective
The aim of the study was to design a portal prototype based onto two models of care and a contextualised education programme to support the self-management of diabetes patients by involving stakeholders in the Iranian province of Razavi-Khorasan.

Methods
A Design-Based Research framework was adopted. A qualitative research method was used to analyse interviews with patients and care givers. Mock-ups were developed first and designed with features of user-driven and self-care models of care. The mock-ups also had adaptation features, such as for control of the disease, ability to cure self, and family support. The portal prototype was developed iteratively by building on the mock-ups and evaluated through interviews. The features and elements of the mock-ups and the portal prototype were evaluated in an outpatient diabetes clinic in Mashhad.

Results
Thirty-three participants were involved in the study. The evaluation of the mock-ups resulted in two themes and seven categories: 1) self-care improvement, including self-care requirements and self-management, and 2) educational usefulness, including medical information, information mode, mobility, interaction, and efficiency. The mock-up evaluation was used as a basis for designing a portal prototype. Next, the portal prototype was evaluated, and three categories emerged from the interview data: 1) user experience, 2) functionality, and 3) interactivity. Participants were not able to prioritise between the two care models. Some functionalities of the portal could benefit from the development within a cultural context to determine differences to the best way to present material.

Conclusions
A portal prototype has been designed to include two care models to support self-management and functionalities that support aspects of culture-specific diabetes self-care. This study provides guidance on developing an internet-enabled educational portal, aimed at providing support for patients in their social context.
Dysdiadochokinesia, Ataxia, and Anemia: A Sign of Intraluminal Malignant Mesothelioma?
Authors: Rozner Raquel , Shah Shawn L. , Chiu Kenrry , Crawford Carl V. 
Published: April 2021

ABSTRACT
An 87-year-old man presented with altered mental status and ataxia was found to have a neuron-restricted antibody in his cerebrospinal fluid, concerning for a paraneoplastic syndrome of unknown origin. He also exhibited anemia, but otherwise normal electrolytes and liver chemistries. He underwent positron emission tomography/computed tomography which revealed abdominal lymphenopathy. He then underwent push enteroscopy and was found to have a jejunal mass, biopsy proven to be malignant mesothelioma. Malignant mesothelioma is 4–5 times more prevalent in men than women. It is limited to the small bowel, and paraneoplastic syndromes are extremely rare and carry a poor prognosis. The presence of anemia with cerebellar symptoms should trigger a search for a paraneoplastic syndrome-related malignancy.
Jakiej filozofii potrzebuje edukacja w świecie XXI wieku?
Authors: Krawczyńska-Zaucha Tatiana 
Published: April 2021

The last decades have witnessed constant changes andrefor ms in education in many countries. The paradox of these changes is that they require further changes and transformations and further reforms. Education systems do not correlate with the needs of humanity in the 21st century, nor with the emerging new world view. This article aims to examine education from the global of the world of digitization in which we live and to find an answer to the question what is the purpose of education in the 21st century. From the analyses of different pedagogicaltre nds and philosophical assumptions underlying them, a conclusion will be drawn about the need for a philosophy open to new challenges in today’s educational reality in order to achieve this goal. This article will addresskey issues of the VUCA world concerning education such as digitization, educate to the unknown, the phenomenon of global teenagers and the development of robotics.
What is the philosophy of education needed in the XXI century?
Authors: Krawczyńska-Zaucha Tatiana 
Published: April 2021

The last decades have witnessed constant changes andrefor ms in education in many countries. The paradox of these changes is that they require further changes and transformations and further reforms. Education systems do not correlate with the needs of humanity in the 21st century, nor with the emerging new world view. This article aims to examine education from the global of the world of digitization in which we live and to find an answer to the question what is the purpose of education in the 21st century. From the analyses of different pedagogicaltre nds and philosophical assumptions underlying them, a conclusion will be drawn about the need for a philosophy open to new challenges in today’s educational reality in order to achieve this goal. This article will addresskey issues of the VUCA world concerning education such as digitization, educate to the unknown, the phenomenon of global teenagers and the development of robotics.
The Export of Commodities and the Validity of the Export-Led Growth (ELG) Hypothesis for the Brazilian Economy: An Analysis of the Commodity Boom Period
Authors: Fagundes Carrara Aniela , Luiz Pesquero Tiago 
Published: April 2021

AbstractThe present study examines the Brazilian economy in the light of the export-led growth (ELG) hypothesis, in order to examine if this hypothesis is valid for periods in which commodities occupy a significant part of exports, for this reason, for the period known as the “commodity boom”. In order to address the proposed objective, the estimation method used was the autoregression with vector error correction (VEC) in its structural version. The results suggest that the economic growth that occurred in Brazil during the analysed period does not corroborate the ELG hypothesis, which is endorsed by results obtained in similar studies.
On the exact and numerical solutions to a new (2 + 1)-dimensional Korteweg-de Vries equation with conformable derivative
Authors: Özkan Yeşim Sağlam , Yaşar Emrullah , Çelik Nisa 
Published: April 2021

Abstract
The aim of this paper is to introduce a novel study of obtaining exact solutions to the (2+1) - dimensional conformable KdV equation modeling the amplitude of the shallow-water waves in fluids or electrostatic wave potential in plasmas. The reduction of the governing equation to a simpler ordinary differential equation by wave transformation is the first step of the procedure. By using the improved tan(φ/2)-expansion method (ITEM) and Jacobi elliptic function expansion method, exact solutions including the hyperbolic function solution, rational function solution, soliton solution, traveling wave solution, and periodic wave solution of the considered equation have been obtained. We achieve also a numerical solution corresponding to the initial value problem by conformable variational iteration method (C-VIM) and give comparative results in tables. Moreover, by using Maple, some graphical simulations are done to see the behavior of these solutions with choosing the suitable parameters.