bluuebunny/crossref_metadata_2025_split huggingface dataset:
Political Dynasties and Economic Development: Evidence using Nighttime Light in the Philippines
Authors: Garces Ludigil , Jandoc Karl , Lu Mary Grace 
Published: April 2021

Abstract
Political dynasties, by limiting political competition, are thought to exacerbate corruption, poverty, and abuse of power. This paper examines the economic effects of the presence of political dynasties in Philippine cities and municipalities, taking into account possible channels in the local dynastic cycle – the framework in which politicians try to balance their goals to perform well for their constituents, to divert resources for personal gain, and to continue to be in power. Due to the lack of extensive income accounts or other economic indicators in finer geographical units (i.e., city or municipality level), we use the Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) nighttime light data as our proxy for economic activity. Using a panel of Philippine municipalities and cities, we find that, in general, the relationship of political dynasties on economic performance is weak. However, we find that a higher share of economic expenditures leads to lower economic development in municipalities where the mayor, governor, and congressman belong to the same clan. We see this as an indication of weak institutions of checks and balances in localities with dynasties.
Integrated transcriptome and proteome analysis reveals complex regulatory mechanism of cotton in response to salt stress
Authors: CHEN Lin , SUN Heng , KONG Jie , XU Haijiang , YANG Xiyan 
Published: April 2021

Abstract
Background
Soil salt stress seriously restricts the yield and quality of cotton worldwide. To investigate the molecular mechanism of cotton response to salt stress, a main cultivated variety Gossypium hirsutum L. acc. Xinluzhong 54 was used to perform transcriptome and proteome integrated analysis.

Results
Through transcriptome analysis in cotton leaves under salt stress for 0 h (T0), 3 h (T3) and 12 h (T12), we identified 8 436, 11 628 and 6 311 differentially expressed genes (DEGs) in T3 vs. T0, T12 vs. T0 and T12 vs. T3, respectively. A total of 459 differentially expressed proteins (DEPs) were identified by proteomic analysis, of which 273, 99 and 260 DEPs were identified in T3 vs. T0, T12 vs. T0 and T12 vs. T3, respectively. Metabolic pathways, biosynthesis of secondary metabolites, photosynthesis and plant hormone signal transduction were enriched among the identified DEGs or DEPs. Detail analysis of the DEGs or DEPs revealed that complex signaling pathways, such as abscisic acid (ABA) and jasmonic acid (JA) signaling, calcium signaling, mitogen-activated protein kinase (MAPK) signaling cascade, transcription factors, activation of antioxidant and ion transporters, were participated in regulating salt response in cotton.

Conclusions
Our research not only contributed to understand the mechanism of cotton response to salt stress, but also identified nine candidate genes, which might be useful for molecular breeding to improve salt-tolerance in cotton.
Formation of a large Vasa-positive germ granule and its inheritance by germ cells in the enigmatic Chaetognaths
Authors: Carré Danièle , Djediat Chakib , Sardet Christian 
Published: April 2021

Chaetognaths (arrow worms) are abundant hermaphrodite marine organisms whose phylogenetic position amongst protostomes and deuterostomes is still debated. Ancient histological observations dating from a century ago described the presence in eggs of a large granule, presumed to be a germ plasm, and its probable inheritance in four primary germ cells (PGCs). Using videomicroscopy, electron microscopy and immunocytochemistry (labelling with anti-Vasa antibodies) we have followed the cycle of aggregation and dispersion of germ plasm and nuage material in eggs, embryos, PGCs and oocytes in several species of benthic (Spadella) and planctonic (Sagitta) chaetognaths. In these animals, germ cells and gametes can be observed in vivo throughout the 1-2 month life cycle.After describing internal fertilization in live animals we show that the single large (15 μm diameter) germ granule forms by a spiralling aggregation movement of small germ islands situated in the vegetal cortex at the time of first mitosis. We also demonstrate that the granule forms autonomously in unfertilized activated eggs or fertilized egg fragments. Once formed, the germ granule first associates with the cleavage furrow and is segregated into one of the first two blastomeres. The germ granule is then translocated from the cortex to the mitotic spindle during 3rd cleavage and remains in the single most-vegetal blastomere until the 32-cell stage. At the 64-cell stage the germ granule is partitioned as nuage material into two founder PGCs and further partitioned into four PGCs situated at the tip of the archenteron during gastrulation. These four PGCs migrate without dividing to reach the transverse septum, then proliferate and differentiate into oocytes and spermatocytes of two ovaries and two testes. We noted that germ plasm and nuage material were associated with mitochondria, the nucleus, the spindle and the centrosome during some stages of development and differentiation of the germ line. Finally, we demonstrate that a Vasa-like protein is present in the germ granule, in PGCs and in the electron-dense material associated with the germinal vesicle of oocytes. These features stress the conservation of cellular and molecular mechanisms involved in germ cell determination.Movies available on-line
The lobster optic lamina : III. Degeneration of retinula cell endings
Authors: Hámori J. , Horridge G. A. 
Published: April 2021

Abstract
In experimentally damaged lobster eyes, the degeneration of retinula cell terminations is at first rapid, but even after 15 days the degenerated endings are not completely eliminated. Degeneration is marked by an accumulation of vesicles and mitochondria, which results in increased osmiophilia of the ending. Synaptic ribbons and spines disappear in the first few days. Processes of glial cells are involved in the gradual disappearance of degenerating endings. There is no remarkable transneuronal degeneration except for loss of poatsynaptic spines. Transverse fibres maintain their synaptic contacts with the ganglion cell axons.
An intranuclear fibrillar lattice in neurons
Authors: Chandler R. L. , Willis R. 
Published: April 2021

ABSTRACT
A new intranuclear structure has been demonstrated in neurons of rat and mouse brain, and studied using conventional electron microscopy and electron stereoscopy techniques. The structure has a crystalline appearance and a variety of profiles was seen in the sections, some showing curvature and one showing ellipticity. The basic component consisted of planes of parallel fibrils; layers of these arrays, usually two in number, crossed each other at an angle, resulting in the appearance of a lattice.
Preparation and properties of the contractile element of insect fibrillar muscle
Authors: Abbott R. H. , Chaplain R. A. 
Published: April 2021

Abstract
Non-myofibrillar enzyme activities persist after glycennation of insect flight muscle. Preservation of mitochondrial structure and function in glycerol-extracted preparations complicates the study of direct effects on the myofibrillar contractile machinery. Non-myofibrillar adenosine triphosphatase and a significant amount of respiration and oxidatdve phosphorylation in the presence of added substrate persist in glycerol-extracted fibres of insect fibrillar muscle stored for 6 months at − 18 °C. The standard procedure used to extract actomyosin from myofibrils also extracts from the mitochondrial fraction a protein which shows the phenomenon of super-precipitation and undergoes viscosity changes in the presence of adenosine triphosphate and metal ions. Preparation of the true contractile structure of insect flight muscle therefore re-quires the removal of all non-myofibrillar activities. Reduction in the total number of mitochondria and of non-myofibrillar enzymic activity is achieved by treatment with the detergent Tween 80 subsequent to glycennation without impairing the mechanical performance of the fibres. This provides better experimental material for studies of the contractile system than the preparations commonly used. The fact that fibres can still perform oscillatory work after treatment with detergent and oligomycin confirms that the control mechanism for oscillation resides within the myofibrils.
Electron- and light-microscope observations on the spleen of the newt Triturus cristatus: the surface topography of the mitotic chromosomes
Authors: Davies H. G. , Tooze J. 
Published: April 2021

Abstract
In polychromatophil erythroblasts, and in cells containing little or no haemoglobin, the surfaces of the mitotic chromosomes frequently bear finger-like projections averaging about 0·1 μ in diameter. Both the mitotic and interphase chromosomes in polychromatophil erythro-blasts from some newts bear, in addition, extensive sheets of chromatin, about 315-465 A thick, depending on fixation, bounded on each side by nuclear envelope-like fragments. The remarkably constant width of the sheets in all cells indicates that chromosomes contain a constructional unit of fixed dimensions. This unit may have general significance, since other workers have found envelope-limited sheets of similar dimensions in one plant and several animal species. An hypothesis concerning the construction of chromosomes is discussed. It seeks to relate the thickness of the sheets of chromatin to the average diameter of the majority of the finger-like processes.
The large intranuclear granules, 400 Å in diameter, in polychromatophil erythroblasts survive in polysome-like configurations in dividing cells.
Observations on the substructure of flagellar fibres
Authors: Grimstone A. V. , Klug A. 
Published: April 2021

Abstract
The substructure of the outer and central fibres of the flagella of Trichonympha and other flagellates has been examined by electron microscopy, using negatively-stained material. Periodicities revealed in the micrographs have been analysed by studying the optical diffraction patterns obtained from them. Outer and central fibres appear to be essentially similar in sub-structure and are made up of a number of longitudinal filaments which form the wall of the hollow fibres. The filaments are 40–50 Å apart, centre to centre, and are beaded, the beads (or subunits) giving rise to an axial repeat along the filaments of 40 Å and a basic surface lattice of 40 × 50 Å. In collapsed or disintegrating fibres no other substructural features are usually visible. In intact fibres, however, additional longitudinal periodicities are apparent. An 80-Å spacing is prominent, and there is commonly also a strong 160-Å repeat. These appear to be orders of a fundamental 480-Å period. The long spacings are thought to arise as departures in the arrangement of the subunits from the simple 40 × 50 Å lattice, the perturbations probably occurring both radially and in the plane of the surface of the fibre. In the central fibres additional material is present, spaced at 160 Å and probably corresponding to the central sheath previously described from sectioned material. Observations on the arms of the outer fibres are described.
Ciliary organelles and associated fibre systems in Euplotes eurystomus (Ciliata, Hypotrichida): I. Fine structure
Authors: Gliddon R. 
Published: April 2021

ABSTRACT
Euplotes eurystomus bears 8 rows of single, non-motile simple cilia, 18 ventral cirri, and a row of adoral membranelies. Each cirrus contains 40–120 cilia in tight hexagonal packing, and each membranelle consists of 3 rows of 10–40 cilia; the component cilia adhere together in life, but no means of adhesion, other than small protuberances of the ciliary membrane, has been seen.
The kinetosomes of compound organelles, but not of the simple cilia, are associated with rootlet fibres. The kinetosomes of the component cilia of compound organelles are linked together at two levels by characteristic arrays of fibres. Single rootlet microtubules (about 20 mμ in diameter) interconnect individual kinetosomes of adjacent membranelles, but the rootlet microtubules arising from cirri are found as bundles, each of which corresponds to one of the fibres seen in the light microscope. The bundles of microtubules of most cirri arise at dense bars near the edge of the cirrus base, and terminate at or near the pellicle, without interconnecting cirri directly or indirectly. The rootlet microtubules of the anal cirri run the length of the base of the cirrus near the inner end of the kinetosomes and join into large bundles; these run anteriorly to join with each other and attach to the distal end of the membranelle row. The anal cirri and the adoral zone of membranelles form one structurally united part of the locomotor apparatus.
A spiral sleeve in rotifer cilia tips
Authors: Dickson M. R. 
Published: April 2021

ABSTRACT
The fine structure of cilia in the gut of the rotifer, Philodina roseola, has been studied. The cilia display the usual structures for the first 9 μ. of their length, but for the last 3 μ the shaft consists of plasma membrane clothing an unusual spiral sleeve. The sleeve is made up of 5 parallel fibres twisted in a left-handed helix about the long axis of the cilium.
Development and determination of hairs and bristles in the milkweed bug, oncopeltus fasciatus (lygaeidae, hemiptera)
Authors: Lawrence P. A. 
Published: April 2021

ABSTRACT
The term ‘ organule ‘ is proposed as an English equivalent for the German word ‘ Kleinorgan The different organules on the third sternite of Oncopeltus are described: larvae possess innervated bristles and special sensilla termed ‘chemosensilla’, whereas the adult develops, in addition, a dense population of non-innervated hairs. The hairs, bristles and ‘chemosensilla’ each develop from mother cells which undergo a particular series of differentiative divisions. The course of events is described for each type of organule.
Electron-microscopic studies of the fine structure of the outgrowing hairs are described. As in the outgrowth of a scale, longitudinal arrays of microtubules and bundles of fibres are found in the first cytoplasmic process of the trichogen cell. Experiments show that bristle determination occurs between the onset of the moult and the proliferative cell divisions in the epidermis. The period of hair determination is found to occur later than that of the bristles and to be later than the proliferative cell divisions in the last larval stage.
A discussion of the results includes a review of the knowledge of differentiative divisions concerned in the formation of organules in other groups of insects, and a consideration of Wigglesworth’s theory of bristle determination.
Chloroplast ribosome deficient mutants in the green alga Chlamydomonas reinhardiand the question of chloroplast ribosome function
Authors: Boynton J. E. , Gillham N. W. , Chabot J. F. 
Published: April 2021

ABSTRACT
The 2 chloroplast ribosome deficient mutants of Chlamydomonas reinhardi, ac-20and cr-I form low levels of 66-s and 70-s chloroplast ribosome monomers compared to wild type, but differ in that cr-I also accumulates substantial amounts of the large (54-s) chloroplast subunit. Unlike wild type, ac-20, cr-I and the double mutant ac-2ocr-i make little or none of the CO2-fixing enzyme ribulose diphosphate carboxylase (RuDPCase) when grown in the light with acetate and CO2 as carbon sources (mixotrophic growth) whereas all 3 mutant genotypes form at least some enzyme when grown photosynthetically with CO2 as the sole carbon source (phototrophic growth). All 3 mutant genotypes also show a characteristic defect in the organization of their chloroplast lamellar system when grown mixotrophically, but their chloroplast membrane organization approaches that of wild type when grown phototrophically. No change in the level of chloroplast ribosomes accompanies these changes in chloroplast organization and RuDPCase formation. We propose that the pleiotropic effects on chloroplast structure and function in mixotrophically grown cells of the mutants result because their chloroplast ribosomes synthesize certain specific chloroplast components with low efficiency, whereas they perform this function with greater efficiency when the cells are grown phototrophically.
Variation in the nuclear sodium concentration of newt oocytes during maturation
Authors: Muir C. , Whitley J. E. 
Published: April 2021

ABSTRACT
Measurements of the sodium content of single oocyte nuclei of Triturus cristatus carnifex at various stages of maturation, show a rise in concentration in eggs of the size 0·5–0·6 mm diameter. When the nuclei are isolated rapidly under paraffin, the absolute values obtained for the concentration are much lower than have been previously reported for this species.
The concentrations of dry matter in mitotic apparatuses in vivo and after isolation from sea-urchin zygotes
Authors: Forer A. , Goldman R. D. 
Published: April 2021

ABSTRACT
We have measured the concentrations of dry matter in mitotic apparatuses (MA) in vivo and after isolation from the same cell type. The isolation medium was hexylene glycol plus buffer. The MA were from sea-urchin zygotes (Echinus esculentus Linn, and Psammechinus miliaris Gmelin), and measurements were made using interference microscopy.
MA as isolated have much lower concentrations of dry matter than do MA in vivo. The dry mass concentrations of isolated MA vary with the pH of the isolation medium, ranging from about 20 % of the in vivo concentration (at pH 7·3) to about 60 % of the in vivo concentration (atpH5·3).
The isolated MA were further characterized. Evidence is presented which suggests that non-specific cytoplasmic material adsorbs to MA, and thus that at least some of the material in isolated MA is not derived from in vivo MA. Some MA components are apparently changed during the isolation procedure: MA lysed in low pH (high mass) medium and quickly transferred to high pH (low mass) medium have higher concentrations of dry matter than do MA lysed in high pH medium.
The isolation media as generally used do not have enough buffering capacity: the pH changes after the isolation.
These data suggest that the isolation procedures need be improved before studies of isolated MA can give data relevant to the chemistry of in vivo MA. We discuss the problem of obtaining functional isolated MA, and also the relevance of our data to previous work on MA from other species.
Intracellular mosaicism (nuclear-/mitochondrial+) for thymidine kinase in mouse l cells
Authors: Clayton D. A. , Teplitz R. L. 
Published: April 2021

ABSTRACT
An electron-microscope and ultracentrifuge examination of mitochondria and mitochondrial DNA from Cl-I-d cells has demonstrated that mitochondria possess the enzyme(s) necessary for incorporation of thymidine and its analogues. These cells lack the nuclear thymidine kinase and are routinely grown in high levels of 5-bromodeoxyuridine (Budr) to select against wildtype revenants. When these cells are grown in the presence of 5-bromodeoxyuridine the mitochondrial DNA incorporates the thymidine analogue into both strands of the DNA duplex while the nuclear DNA shows no incorporation. Approximately 13 % of the total thymidines of the M-DNA are replaced by 5-bromodeoxyuridine and the DNA exhibits the form expected for normal mouse mitochondrial DNA. If the cells are grown in normal medium the mitochondrial DNA regains its normal base composition. Comparison of mitochondrial morphology under these 2 conditions reveals that the presence of 5-bromodeoxyuridine results in a distortion of the cristae similar to the effect induced by chloramphenicol. It is hypothesized that the incorporated mutagen (5-bromodeoxyuridine) may be altering the protein products of mitochondrial DNA. The results suggest (1) the existence of a separate and distinct thymidine kinase in the mitochondria of mouse L cells and (2) mutagenic but reversible effects of Budr incorporated into mitochondrial DNA.
Premature chromosome condensation: a mechanism for the elimination of chromosomes in virus-fused cells
Authors: Rao P. N. , Johnson R. T. 
Published: April 2021

ABSTRACT
The fate of prematurely condensed chromosomes (PCC) that are induced following fusion between a mitotic and an interphase cell was studied in the homokaryons of HeLa and 2 glycine-requiring mutants of Chinese hamster ovary cells. The data indicate: (1) the prematurely condensed chromosomes are often incorporated into daughter nuclei of the fused cells and hence they are functionally retained by the progeny; (2) in general, the only viable products of fusion between mitotic and interphase cells are those where PCC has been induced; (3) fusion between mitotic and S-phase cells leads to the most rapid loss of chromosomes, while the homophasic fusions tend to produce more stable hybrids with regard to their chromosome number.
The effect of cell population density on nutrient uptake and cell metabolism: a comparative study of human diploid and heteroploid cell lines
Authors: Griffiths J. B. 
Published: April 2021

ABSTRACT
The possibility that contact inhibition of growth in cultures of human diploid cells is influenced by the effects of cell crowding on nutrient uptake by the cells was investigated. Two human lung cell lines were compared, the diploid line MRC-5 and the heteroploid line L-132. In pre-confluent cultures the ability of these 2 cell types to accumulate amino acids was very similar. Post-confluent L-132 cells showed very little change from the pre-confluent cultures but the ability of MRC-5 cells in post-confluent cultures was greatly reduced. The intracellular concentrations of various amino acids necessary to achieve the maximum rate of protein synthesis were found. These values were identical for sparse and crowded cultures but due to the reduced uptake ability of crowded MRC-5 cells a far higher external amino acid concentration was required in post-confluent cultures. This meant that although amino acids did not become growth-limiting until over 80 % utilized in pre-confluent cultures, in post-confluent cultures they became growth-limiting when only 50 % utilized.
Although protein synthesis was significantly affected by extracellular amino acid concentration and cell crowding, thus contributing towards the effect of contact inhibition of growth, DNA synthesis was shown to be the major metabolic function in contact inhibition. Increased cell density had a very inhibitory effect on DNA synthesis in MRC-5 cultures, but not in L-132 cultures, and this was unaffected by extracellular amino acid and glucose concentration.
The effect of injections of lysophosphatidyl choline into white matter of the adult mouse spinal cord
Authors: Hall Susan M. 
Published: April 2021

ABSTRACT
The action of lysophosphatidyl choline, LPC, on myelinated fibres in the dorsal white matter of the spinal cord of the adult mouse has been studied electron microscopically, and compared with the recently described activity of LPC in the peripheral nerve fibre.
Control injections of sterile isotonic saline and injections of LPC both produced oedematous zones in the white matter; within these zones, many fibres exhibited the characteristic changes of Wallerian degeneration. After injection of LPC, however, an area of demyelination was observed, extending within and beyond the Wallerian degeneration. Ultrastructurally, demyelination involved progressive disruption of the previously-compact sheath, observed initially as a splitting of the intraperiod line within 30 min. Subsequent breakdown was-indicated by the appearance of strands of 4-6 nm repeat lamellar material, itself further degraded through quintuple- and triple-layered lamellar units to disorganized membranous networks around undamaged axons.
The significance of the demyelinating activity of LPC is discussed in terms of its known action in in vitro systems of isolated central nervous tissue, and its action in vivo in the peripheral nervous system.