bluuebunny/crossref_metadata_2025 huggingface dataset:
Defect Structures in Neutron-Irradiated Iron
Authors: Bentley J. , Horton L. L. , Farrell K.
Published: June 2020

The secondary defect structures formed in iron by neutron irradiation
have received little attention in comparison to both the bcc refractory and
fee metals. This is surprising in view of the importance of ferritic steels
but may be partly due to the difficulty of TEM examination of ferromagnetic
materials. We have performed a TEM study of Fe neutron irradiated in the Oak
Ridge Research Reactor at temperatures from 182 to 500°C to ˜1 dpa and at
650 and 740°C to ˜0.5 dpa. The specimens were fabricated from two-pass
zone-refined Ferrovac E iron (0.003 wt % C) and disks were irradiated in
sealed capsules. TEM examination was performed at 120 kV in a JEM 120C
equipped with a special objective lens pole-piece (AMG) for the observation
of magnetic materials in order to make possible high-angle tilting
experiments.
On The Visibility of Supported Metallic Particles
Authors: Romeu D. , Gómez A. , Yacamán José M. , Domínguez J.M.
Published: June 2020

Several methods have been presented for the calculation of diffraction
intensities in the case of twin boundaries and other two-crystal systems in
the N-beam approximation (1,2,3). It has been realized that when two or more
beams diffracted by the top crystal differ by a reciprocal lattice vector of
the bottom crystal, the beams become coupled and the problem requires
special treatment. It has been pointed out (3) that the methods described in
references (2) and (3) are formally equivalent for an infinite number of
beams but the method described by Gomez et al (3) requires less computing
time.
Structural Investigation of Iron Particles Used for Magnetic Recording
Media
Authors: Baltz Alfred
Published: June 2020

As part of a program to develop iron particles for next generation
recording disk medium, their structural properties were investigated using
transmission electron microscopy and electron diffraction. Iron particles
are a more desirable recording medium than iron oxide, the most widely used
material in disk manufacturing, because they offer a higher magnetic output
and a higher coercive force.

The particles were prepared by a method described elsewhere. Because of
their strong magnetic interaction, a method had to be developed to separate
the particles on the electron microscope grids.
Ultrastructural Changes in Rough Endoplasmic Reticulum of Renal Proximal
Tubule Cells in Tetraethyllead Poisoning
Authors: Wade P. R. , Chang L. W. , Wade V. L.
Published: June 2020

Tetraethyllead (TEL), a gasoline antiknock additive, poses an
occupational and environmental risk to human health. Renal damage is a
prominent finding in human TEL intoxication. Levels of urinary and
erythrocyte ALA-D are altered. Histological examination of the renal
parenchyma reveals degenerative changes in the proximal tubules.
Experimental TEL studies also demonstrate kidney damage in mice, rats,
rabbits, and dogs by various investigators.

The basic pathogenetic mechanism of TEL poisoning is unknown. However,
in view of the disruption of rough endoplasmic reticulum (RER) and protein
synthesis which constitutes the pathogenetic mechanism of methylmercury
poisoning, alteration of the RER may also underl ie the toxic impact of
organolead in the cells. This report presents unique ultrastructural
findings of such an investigation.
Localization of Immune Complexes in the Basement Membrane of the Ductuli
Efferentes of the Rhesus Monkey
Authors: Marsh D.
Published: June 2020

As a result of vasectomy, spermatozoa are confined to the epididymis and
vas deferens, where they degenerate, releasing antigens that enter the
circulation or are engulfed by macrophages. Multiple antigens of the sperm
can elicit production of autoantibodies; circulating anti-sperm antibodies
are found in a large percentage of vasectomized men, indicating the
immunogenicity of the sperm.

The increased prevalence of macrophages in the liomen of the rhesus
monkey testicular efferent ducts after vasectomy led to further study of
this region. Frozen sections were used for evaluation of immunopathological
status by fluorescence microscopy with fluorescein-conjugated antibody.
Subsequent granular deposits of immune complexes were revealed by positive
immunofluorescence staining for complement. The immune complex deposition in
the basement membrane surrounding the efferent ducts implies that this
region is involved in antigen leakage (Fig. 1).
Umatilla Virus Association with Fibrils and Tubules in Cultured
Cells
Authors: Foster Neil M. , Breckon Ruth D.
Published: June 2020

Macrotubules have been described1 in cells infected
with Umatilla virus (UMAV), an orbivirus for which bluetongue virus (BTV) is
the protype. Macrotubules, often in linear array, were observed in the
cytoplasm and in intimate association with viroplasms of infected cells.
Macrotubules had outside and inside diameters of 20 and 15 nm and many had
dark-staining centers with diameters similar to the interiors of the
tubules. UMAV was 60 nm and the RNA core was 30 nm in diameter. This report
describes the association of UMAV with macrotubules and two types of
microtubules.
Electron Microscopy of Fresh and Dried Cells of Chlorella
Pyrenoidosa
Authors: LIN L. P.
Published: June 2020

Photosynthetic unicellular algae can be cultivated by employing mass
production techniques. The harvested Chlorella cells from the mass culturing
pools are separated by centrifugation. In the Orient, the pellets are washed
and dried in the spray dryer. Finally, the dried powder is packed in vaccum
for the starting materials of natural foods. Spray-dried cells of Chlorella
were examined by SEM. Most of the droplets of spray-dried cells showed,
50–85μm in diameter (Fig. 1). At the higher magnification, it exhibited that
this spherical structure consists of more than a few thousands of single
Chlorella cells (Fig. 2), and each cell pilling up or sticking together. The
ash-like materials which attached to the surface of cells, probably produced
from the cells because of the heat treatment or elevated temperature of hot
air from spraying dryers. The cells prepared for SEM by glutaraldehyde
fixation and critical point drying had the smooth surface with wrinkled
parts. Cells were spherical and measured 2-6 μm in diameter. For the
contaminated culture, the photosynthetic purple bacteria are shown to stick
on the surface of algal cells. The inside of each particle was revealed by
using cryofracture technique. Each particle was occupied by a hole in the
center, and its diameter was approximately one-half of the particle in
sectional view (Fig. 3).
An Ultrastructural Mechanism for Particle Entrapment and Attachment by
the Reticulopodial Network of Allogromia
Authors: Bowser S. S. , McGee-Russell S. M.
Published: June 2020

The reticulopodial network (RN) of the marine foraminiferan Allogromia
participates in the feeding, locomotion and division of the organism. We
have examined the ultrastructure of the network using a variety of TEM and
SEM techniques in order to study feeding and attachment. We report the
existence of “ultra-microspikes” (UMS) and “ultra-microwebs” (UMW) which
participate in these two processes. Model experiments with glass fiber
particles and latex spheres were executed to confirm the
mechanisms.
A Quantitative Scanning Electron Microscopic Investigation of Aquatic
Bacterial Populations: Diel Variability
Authors: Dreier Thomas M.
Published: June 2020

Two important variables in sampling aquatic bacterial populations are
the sampling interval (time and space) and the species of bacteria that
compose the bacterial population. Scanning electron microscopy (SEM) has
proven to be an accurate method for estimation of both the density and
composition (based on morphological characters) of aquatic bacterial
populations (1). This investigation was undertaken to quantify the diel
population dynamics of a morphologically distinct population from a
stratified aquatic environment. This type of information has not been
previously obtainable with other enumeration techniques.

Samples were taken from a stratified pond located in Central Texas.
Water samples (n=4) were collected employing sterile techniques from the 2.0
m strata every three hours from 1000 hrs, 24 August to 1000 hrs, 25 August
1979. Bacterial samples were prepared for SEM according to the methods of
Dreier and Thurston (2). Bacteria were classified and enumerated with SEM
into 54 morphologically identifiable types (fig. 1a and 1b). The frequency
of dividing cells (FDC) for R26 was calculated as the percentage of R26
showing septum formation (fig. 1b) to the total number of R26.
Use of Antibody to aid Visualization of Protein at the Termini of
Bacteriophage Ø29 DNA
Authors: Anderson Dwight , Peterson Charlene , Notani Gursaran , Reilly Bernard
Published: June 2020

The protein product of cistron 3 of Bacillus subtilis bacteriophage Ø29
is essential for viral DNA synthesis and is covalently bound to the
5’-termini of the Ø29 DNA. When the DNA-protein complex is cleaved with a
restriction endonuclease, the protein is bound to the two terminal
fragments. The 28,000 dalton protein can be visualized by electron
microscopy as a small dot and often is seen only when two ends are in
apposition as in multimers or in glutaraldehyde-fixed aggregates. We sought
to improve the visibility of these small proteins by use of antibody
labeling.
Electron Microscopic Analysis of Asymmetry within the Cell Nucleus of DNA
Helix Openings During Human Cell Activation and Cell Differentiation
Authors: Frenster J. H.
Published: June 2020

Most of the DNA molecules within an animal cell are repressed for RNA
synthesis at any one time, and those DNA molecules that are active are
characteristic of the particular tissue or organ within which the cell has
differentiated (1). This phenomena of differential gene transcription is
thought to be the epigenetic basis for such diverse cell activities as cell
differentiation organ regeneration, neoplastic transformation, immune
activation, and the response to steroid hormones (2).

Carcinogenic chemicals, oncogenic viruses, embryogenic RNA, immune RNA,
and steroid hormones all prefer to bind to single-stranded regions within
DNA molecules of the host cell (3). DNA molecules which are active in RNA
synthesis display short loops of such single-stranded DNA (4), which are a
necessary prerequisite for the gene de-repression characteristic of animal
neoplasms (5).
Ribosomal Structure and Functional Sites Mapped by Immune Electron
Microscopy
Authors: Lake James A.
Published: June 2020

Ribosomal protein locations have been mapped on the ribosomal surface by
using antibodies directed against specific ribosomal proteins. Relative
orientations of the large and the small subunits in the monomeric ribosome
have been determined using a double labeling approach; and functional
regions such as the codon-anticodon interaction site, the tRNA binding sites
and the peptidyl transferase have been suggested from the locations of
ribosomal proteins.

The small ribosomal subunit (see Figure 1) is divided by a constriction
into a one-third, or head, and a two-thirds, or base, region (1). A
platform, located on the base, forms a cleft between it and the upper
one-third of the subunit. The cleft, the upper one-third and the platform
are thought to comprise the binding sites for mRNA and for initiation
factors IFl, IF2 and IF3. The locations of some of the proteins involved in
tRNA binding that have been mapped in collaboration with Dr. L. Kahan
(Department of Physiological Chemistry, University of Wisconsin) are
summarized in Figure 1. In addition, some proteins such as S4 are not
accessible for IgG binding (2). Protein S4 is being mapped using
reconstituted subunits lacking S5 and S12 (3). The binding sites for
proteins Si, S11, S12 and S18 (not shown) are located on the platform and
suggest that the site of the codon-anticodon interaction is also
there.
Epidermal Effects of Topically Applied Retinoic Acid: Microscopic
Observations
Authors: Baker K. W. , Habowsky J. E. J.
Published: June 2020

Retinoic acid (RA) (Vitamin A) is known to induce profound metabolic
changes in keratinizing epithelia in vivo and in vitro (1,2). These changes
include a direct influence on epidermal mitotic activity (3) and the
induction of altered patterns of differentiation (I). In the present study
we are attempting to further elaborate on epidermal changes observed during
prolonged exposure to 0.3% and 1% RA topically applied in a propylene glycol
vehicle.
Sem Observations in Gastric Mucosa Exposed to Progressive Enzymatic
Etching
Authors: Lemmi C.A.E. , Booth D. , Adomian G.E.
Published: June 2020

In order to enrich populations of homogeneous cellular types we
dissociated gastric mucosa by enzymatic techniques. In addition, we used SEM
to monitor the progressive etching of the mucosa. Two enzymes were tested:
collagenase III with minimum proteolytic activity and Pronase with broader
proteolytic effects. The gastric mucosa was exposed to the effect of the
enzymes using everted stomach preparations. In this way the digestive action
occured progressively from the lumen of the stomach toward the base of the
glands. This “etching” process could be monitored conveniently by SEM. After
incubation for periods varying from 30 to 210 minutes the tissues were
stretched on dental wax, fixed in 2 % glutaralheyde, post-fixed in osmium,
dehydrated, critical point dryed and coated with gold. A model MSM-5
“Mini-SEM” was used for observation. Gentle uncurling of the preparation
before coating with gold produced fractures which revealed the structure of
the gastric glandsin more detail.
Function of the Cortical Actin Lattice in the Motor of Macrophages
Authors: Stossel T.P.
Published: June 2020

Macrophages are cells of the hematopoietic system with important defensive functions in the tissues of higher animals. Movement is an important aspect of the execution of these functions, which include locomotion, spreading on surfaces and the phagocytosis of foreign debris and microorganisms. These cells also secrete lysosomal enzymes by the process of exocytosis, and the released enzymes may play a part in the pathogenesis of tissue destruction during inflammation.

The “motor” region of macrophages appears to reside in the peripheral cytoplasm beneath the plasma membrane. This cortical region ordinarily excludes lysosomes and other organelles, and, although evident throughout the entire cell periphery, it is particularly prominent in veils, pleats and pseudopodia extended by the cell ( 1 ).
Role of the Cilia Membrane in Control of Microtubule Sliding
Authors: Kaneshiro Edna S.
Published: June 2020

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+concentrations. The Ca2+levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6M Ca2+Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.
Freeze-Fracture Appearance of Rabbit Cardiac Sarcoplasmic
Reticulum
Authors: Dolber Paul C. , Sommer Joachim R.
Published: June 2020

A number of investigators have demonstrated by thin-section electron
microscopy the presence of "coated dense vesicles" associated with the
sarcoplasmic reticulum (SR) of mammalian cardiac muscle. The similarity of
such vesicles to junctional SR (JSR) has been reported: They are at¬tached
to SR tubules, they have "feet" at their cytoplasmic surface, and they
contain electron-dense material (Fig. 1). Accordingly, and In con¬sideration
of their shape, they have been named corbular SR (CSR). We here report the
freeze-fracture appearance of the SR, especially the CSR, in the rabbit
heart.
Application of Spurr, LX112, LX112/ARALDITE 502, POLY/BED 812 and
Effapoxy Embedding Media to in Vitro Agar-Cultured Bone Marrow
Colonies.
Authors: Buchanan Glenn M. , Stewart Dennis A.
Published: June 2020

In vitro bone-marrow derived colonies cultured in agar and prepared in
Epon 812 for electron microscopy occassionally produce blocks that are too
soft for sectioning. We attribute this softness to the retention, after
standard dehydration, of water by the agar and to the relatively slow
penetration of the agar by Epon-based embedding media. The agar cannot be
removed or replaced since this would disrupt the colony integrity and
prevent the study of cell-cell relationships. This paper describes the
procedures and results of more extensive specimen dehydration and of
embedding with Epon-replacement formulations.
Mass Measurement with the Stem-Biological Applications
Authors: Hainfeld J. , Wall J.
Published: June 2020

The scanning transmission electron microscope (STEM) is well equipped to perform quantitative measurements on biological specimens. Fertig and Rose have shown that signal from the large angle annular detector in the STEM is essentially an incoherent superposition of the signals from independent scatterers. This means that for a sample composed of only a single type of atom, the large angle annular detector signal is directly porportional to mass thickness. For atoms close together in the periodic table, the Z3/2(Z=nuclear charge) dependence of elastic scattering can usually be approximated as the atomic weight and again the signal will be nearly proportional to mass thickness. For atoms of widely differing Z, it will usually be necessary to rely on knowledge of specimen composition and experimentally determined scattering cross sections.
Labeling Techniques for the Analysis of Cell Surface Glycoproteins
Authors: Molday R.S.
Published: June 2020

Surface membranes of animal cells display a wide variety of glycoproteins, many of which serve as enzymes, transport components or receptors for extra-cellular molecules and molecular complexes. In recent years specific label-ing techniques have been developed to detect, quantitate and study the ultra-structural organization and biochemical properties of cell surface membrane glycoproteins. Studies utilizing these techniques have contributed to our general understanding of membrane structure and have provided some insight into the role of specific membrane components in cellular communication and regulation.
Ultrastructural Immunocytochemistry of Five Rat Pituitary
Adenomas
Authors: McComb D. J. , Ryan N. , Horvath E. , Kovacs K. , Nagy E. , Berczi I. , Domokos I. , LaszIo F. A.
Published: June 2020

Conventional light and electron microscopic techniques failed to clarify
the cellular composition and derivation of spontaneous and induced,
intrasellar and transplanted pituitary adenomas in rats (1). In the present
work, electron microscopic immunocytochemistry was applied to evaluate five
adenohypo-physial tumors using a technique described by Moriarty and Garner
(2).

Spontaneously occurring pituitary adenomas (group 1) were harvested from
aging female Long-Evans rats. R-Amsterdam rats were treated with 2 x 1.0 mg
estrone acetate (HogivaI) s.c. weekly for 6 months. Pituitary adenomas in
excess of 30 mg were removed from these animals to make up the tumors of
group 2. Groups 3 and 4 consisted of estrogen-induced autonomous
transplan¬ted pituitary tumors MtT.WlO and MtT.F4. Group 5 was a
radiation-induced transplanted autonomous pituitary tumor MtT.W5. The tumors
of groups 3,4 and 5 were allowed to proliferate in host rats 6-8 weeks prior
to removal for processing. Tissue was processed for transmission electron
microscopy (glutaraldehyde fixation, OsO4 postfixation
and epoxy resin embedding), and electron microscopic immunocytochemistry (3%
paraformaldehyde fixation and Araldite embedding).
Ultrastructure of Colonic Neoplastic Cells in Metastases of
Tamarins
Authors: Swartzendruber D. C. , Miller Pat N. , Richter C. B.
Published: June 2020

The cotton-topped tamarin, Saguinus oedipus oedipus, develops colonic
cancer spontaneously . We examined 4 cases of colonic mucinous
adenocarcinomas with metastatic involvement to adjacent lymph nodes in this
subhuman primate. Cells that metastasize are considered highly malignant and
we undertook an ultrastructural study to describe the cell types in these
lesions. Colonic cancers usually display rather large variations in cellular
patterns that pathologists use to classify these neoplasms. By limiting our
study to neoplastic cells in metastases, we are attempting to characterize
the ultrastructure of malignant cells and their progeny. Our purpose is to
provide insight into the cell of origin of colonic carcinomas and to
determine whether malignant cells differentiate and become postmitotic
.
Ultrastructure of Angiosarcoma of Mouse Tail
Authors: Yvonne White , Sheldon Winslow , Townsend James W. , Littlefield Neil A.
Published: June 2020

Spontaneous neoplasms rarely occur on the tails of BALB/cStCrlfC3H/Nctr
mice, but the neoplasm most frequently observed is a locally invasive
non-metastatic angiosarcoma. In this case a female mouse weighing 33.2 g,
706 days of age, presented a soft, red, irregularly-shaped mass, measuring
18 mm in its greatest dimension, in the subcutis of the base of the tail. A
portion of the tail tumor was taken for electron microscopy and the
remainder was processed for light microscopy. The tissue processed for
electron microscopy was fixed in 4% cacodyl ate-buffered glutaraldehyde,
post-fixed in 1% osmium tetroxide, dehydrated in a graded series of ethanol
solutions, and embedded in Epon-Araldite resin mixture. Sections of 1 μm
were stained with toluidine blue for light microscopy and ultrathin sections
of 100 nm were stained with uranyl acetate and lead citrate, then examined
with a Philips EM201 electron microscope .
Adsorption Staining Methd For Ultrathin Frozen Sections
Authors: Tokuyasu K. T.
Published: June 2020

The successful routine use of cryoultramicrotomy to examine ultrathin
sections by transmission electron microscopy requires the application of
suitable staining to delineate the ultrastructure. While negative staining
is quite effective for certain purposes1, 2, positive
staining is more appropriate for immunocytochemical studies because it does
not obscure the immunolabels.
Application of Sem to The Human Tumor Cloning System
Authors: Zeagler J. , Bajpai V. K. , Harris G. , Von Hoff D. D.
Published: June 2020

The human tumor cloning system is a two-layer soft agar technique used
to grow human tumors directly from biopsy material (1). A nutrient “feeder”
layer forms the bottom layer with the tumor-cell-containing layer plated on
top. This combination of two-layer plating enables the “feeder” layer to
separate the tumor cell suspension from the bottom of the plate and does not
allow fibroblasts to attach to dish, which they must do in order to
grow.
Comparative Studies on The Membranes of Llama and Human
Erythrocytes
Authors: Khodadad J. K. , Weinstein R.S.
Published: June 2020

The erythrocytes of llama (Llama glama) have properties which render
them of interest for membrane studies. It is known that these erythrocytes
do not deform under shear stress and that they have an ellipsoid
shape1 . The shape and deformability properties of
erythrocytes are thought to be governed by some type of association between
the peripheral and integral proteins of the membrane. Spectrin and actin are
the major peripheral proteins which constitute the cytoskeleton. The
cytoplasmic domain of the integral protein, band 3, is believed to be
involved through its association with the cytoskeleton. In view of these
considerations, the biochemical and ultrastructural characterization of the
llama erythrocyte membrane and its comparison with that of the human
erythrocyte may provide important data which will contribute to our
understanding of cytoskeletal structure.
The Cytoplasmic “Microtrabecular Lattice” - Reality or Artifact
Authors: Ris H.
Published: June 2020

In vertebrate cells microtubules, 10 nm “intermediate” filaments and 6
nm actin filaments are generally accepted as the major units of the
so-called “cytoskeleton.” Recently an additional organelle has been proposed
as a component of the cytoskeleton, the “microtrabecular lattice” (1). This
network of filaments 4-10 nm thick is said to form the ground substance in
which other organelles are embedded. Its structure resembles spongy bone,
forming a three-dimensional network of “trabeculae” which characteristically
vary in thickness as if plastically deformed by stress. This appearance is
not seen in sections of embedded cells but is found in micrographs of whole
mounts of cells dried by the critical point procedure.
An X-Ray Projection Microscope Stage for the Cambridge S.180 S.E.M. and
its Biological Applications
Authors: Fletcher S. , Hannah R. S. , Hollenberg M. J.
Published: June 2020

The purpose of this study was to develop a functional microscope system
to overcome the inherent disadvantages of using the light microscope/camera
lucida system to reconstruct sections of biological material. The problem is
perhaps most acute in the nervous system, where reconstruction of
3-dimensional neurons or the tracing of neuronal pathways over extensive
distances must be attempted. The camera lucida system suffers from many
inaccuracies and is an extremely time-consuming and tedious
procedure.

Point projection x-ray microscopy in the SEM, entails utilizing the
primary electron beam in the spot mode to generate a point source of x-rays
from a suitable target (Al, Cu, Au). This technique was first successfully
demonstrated by Horn and Waltinger (1978).
Considerations of the Current Potential and Limits of Analytical Electron
Microscopy
Authors: Williams D. B.
Published: June 2020

With the development of the scanning transmission electron microscope
(STEM) the TEM was transformed into an analytical instrument capable of high
resolution microanalysis and diffraction, as well as offering a broad range
of imaging techniques. The combination of a < 10 nm electron probe and
thin foil specimens permits analytical information to be gained from regions
< 50 nm in diameter since beam spreading in thin specimens is of this
order. This article will use specific examples to illustrate the possible
applications of STEM in the study of materials, as well as the physical
limitations of the analysis procedure which are only now being
defined.
Efficacy of experimental phage therapies in livestock
Authors: Dec Marta , Wernicki Andrzej , Urban-Chmiel Renata
Published: June 2020

Bacteriophages are the most abundant form of life on earth and are present everywhere. The total number of bacteriophages has been estimated to be 1032 virions. The main division of bacteriophages is based on the type of nucleic acid (DNA or RNA) and on the structure of the capsid. Due to the significant increase in the number of multi-drug-resistant bacteria, bacteriophages could be a useful tool as an alternative to antibiotics in experimental therapies to prevent and to control bacterial infections in people and animals. The aim of this review was to discuss the history of phage therapy as a replacement for antibiotics, in response to EU regulations prohibiting the use of antibiotics in livestock, and to present current examples and results of experimental phage treatments in comparison to antibiotics. The use of bacteriophages to control human infections has had a high success rate, especially in mixed infections caused mainly by Staphylococcus, Pseudomonas, Enterobacter, and Enterococcus. Bacteriophages have also proven to be an effective tool in experimental treatments for combating diseases in livestock.
Playful Work Design: Introduction of a New Concept
Authors: Bakker Arnold B. , Scharp Yuri S. , Breevaart Kimberley , de Vries Juriena D.
Published: June 2020

This article introduces the concept of playful work design—the process through which employees proactively create conditions within work activities that foster enjoyment and challenge without changing the design of the job itself. First, we review play theory and the motives people may have to play during work. In addition, we use the literature on proactive work behavior to argue that individuals can take personal initiative to increase person-job fit. Combining these literatures, we provide a theoretical framework for playful work design. We discuss the development and validation of an instrument to assess playful work design, and review recent studies to elucidate the psychological effects of playful work design and its possible outcomes. Finally, we briefly discuss practical implications.
How Do People Code Information in Working Memory When Items Share Features?
Authors: Plancher Gaën , Goldstone Robert L.
Published: June 2020

Abstract. A large literature suggests that the way we process information is influenced by the categories that we have learned. We examined whether, when we try to uniquely encode items in working memory, the information encoded depends on the other stimuli being simultaneously learned. Participants were required to memorize unknown aliens, presented one at the time, for immediate recognition of their features. Some aliens, called twins, were organized into pairs that shared every feature (nondiscriminative feature) except one (discriminative feature), while some other aliens, called hermits, did not share feature. We reasoned that if people develop unsupervised categories by creating a category for a pair of aliens, we should observe better feature identification performance for nondiscriminative features compared to hermit features, but not compared to discriminative features. On the contrary, if distinguishing features draw attention, we should observe better performance when a discriminative rather than nondiscriminative feature was probed. Overall, our results suggest that when items share features, people code items in working memory by focusing on similarities between items, establishing clusters of items in an unsupervised fashion not requiring feedback on cluster membership.
Long‐Term Variations of >16‐MeV Proton Fluxes: Measurements From NOAA POES and EUMETSAT MetOp Satellites
Authors: Lin Ruilin , Zhang Jichun , Zhang Xiaoxin , Ni Binbin , Liu Siqing , Shi Liqin , Gong Jiancun , Wang Hong , Cao Yong
Published: June 2020

Based on the recalibrated data of >16‐MeV proton omnidirectional integral fluxes obtained from NOAA POES and EUMETSAT MetOp satellites during the period from 1978 to 2014, solar cycle phase lags, the variations of proton radiation belt, and the relationships between trapped proton fluxes and F10.7 flux, cosmic ray, or sunspot number are investigated in detail. It is found that (a) the solar cycle phase lags between energetic proton fluxes and sunspot number are within 2.5 years, dependent on solar cycle, Lm, B/B0, and proton energy; (b) at the magnetic equator, the ratios of the maximal to minimal values of 4‐month smoothed monthly >16‐MeV proton fluxes during the period from 1978 to 2014 increase and then decrease with increasing Lm, showing the maximal value ~11.24 at Lm = 1.15; and (c) at a magnetic field line with Lm ≤ 1.15, the ratios of the maximal values in 1987 to the minimal values in 2002 for yearly >16‐MeV proton fluxes decrease with increasing B/B0, while at a magnetic field line with Lm ≥ 1.16, they increase and then decrease with increasing B/B0, and the maximal ratio for all magnetic field lines can reach above 20. An exponential equation with an offset is feasible to describe the relationship between the logarithm of >16‐MeV proton fluxes and F10.7 flux. It can be readily used to improve the NOAAPRO model.
Generation and Intensification of Mesoscale Anticyclones by Orographic Wind Jets: The Case of Ierapetra Eddies Forced by the Etesians
Authors: Ioannou Artemis , Stegner Alexandre , Dubos Thomas , Le Vu Briac , Speich Sabrina
Published: June 2020

Motivated by the recurrent formation and intensification of the Ierapetra anticyclones in the southeast of Crete, we investigated with a reduced gravity model the response of the oceanic surface layer to a seasonal wind jet that varies slowly (over several weeks or months) and mimics the Etesian winds. Our study answers why the oceanic response to such forcing is mainly a large and intense anticyclone. We build a dimensionless parameter that integrates in time the Ekman pumping and quantifies the relative amplitude of the isopycnal displacement induced by the local wind stress curl. According to the range of the wind forcing parameter, the oceanic response to a symmetric wind jet could be a symmetric dipole or a strongly asymmetric structure dominated by an intense and robust anticyclone. This intrinsic asymmetry is driven by the finite isopycnal displacements that occur when the wind forcing parameter reaches unity. Since the anticyclonic wind shear for the Etesian wind jet is 2 times larger than the cyclonic one, the asymmetry of the oceanic response is enhanced. Several weeks after the wind forcing has stopped, an intense mesoscale anticyclone which satisfies the cyclogeostrophic balance remains. Moreover, if a similar wind jet blows on a preexisting anticyclone, the latter remains robust and coherent and gets reintensified in agreement with the previous analysis of remote sensing observations. Hence, this paper is the first numerical study which provides a dynamical understanding for the formation of the single Ierapetra anticyclones and explains their intensification 1 year after formation.
Dynamics of Auroral Precipitation Boundaries Associated With STEVE and SAID
Authors: Nishimura Y. , Donovan E. F. , Angelopoulos V. , Nishitani N.
Published: June 2020

Using Defense Meteorological Satellite Program (DMSP) and National Oceanic and Atmospheric Administration (NOAA) satellite observations and ground‐based observations by the THEMIS all‐sky imagers (ASIs) and SuperDARN radars, we determine how the equatorward boundary locations of ring current ions and plasma sheet electrons at pre‐midnight relate to occurrence of strong thermal emission velocity enhancement (STEVE) and intense subauroral ion drifts (SAID) during substorms. We found that the STEVE events are associated with a sharper gradient of electron precipitating flux, lower precipitating ion flux, and a narrower (<1°) latitudinal gap between the equatorward boundaries of trapped ring current ions and precipitating plasma sheet electrons and narrower region‐2 field‐aligned currents (FACs) than for the non‐STEVE events. The narrow gap of the particle boundaries contains intense SAID, higher upflow velocity, lower trough density, and slightly higher electron temperature than those for the non‐STEVE events. The non‐STEVE substorms have much wider gaps between the trapped ions and precipitating electrons, and subauroral polarization streams (SAPS) do not show intense SAID. These results indicate that subauroral flows and downward FACs for the STEVE events can only flow within the latitudinally narrow subauroral low‐conductance region between the ion and electron boundaries, resulting in intense SAID and heating. During the non‐STEVE events, the SAPS flows can flow in the latitudinally wide region without forming intense SAID.
Viscoelastic Relaxation within the Moon and the Phase Lead of Its Cassini State
Authors: Organowski Olivier , Dumberry Mathieu
Published: June 2020

Analyses of Lunar Laser Ranging data show that the spin symmetry axis of the Moon is ahead of its expected Cassini state by an angle of ϕp = 0.27 arcsec. This indicates the presence of one or more dissipation mechanisms acting on the lunar rotation. A combination of solid‐body tides and viscous core‐mantle coupling have been proposed in previous studies. Here, we investigate whether viscoelastic deformation within a solid inner core at the center of the Moon can also account for a part of the observed phase lead angle ϕp. We build a rotational dynamic model of the Cassini state of the Moon that comprises an inner core, a fluid core, and a mantle and where solid regions are allowed to deform viscoelastically in response to an applied forcing. We show that the presence of an inner core does not change the global monthly Q of the Moon and, hence, that the contribution from solid‐body tides to ϕp is largely unaffected by an inner core. However, we also show that viscoelastic deformation within the inner core, acting to realign its figure axis with that of the mantle, can contribute significantly to ϕp through inner core‐mantle gravitational coupling. We show that the contribution to ϕp is largest when the inner core viscosity is in the range of 1013 to 1014 Pa s, when the inner core radius is large and when the free inner core nutation frequency approaches a resonance with the precession frequency of 2π/18.6 yr−1.
ETo‐Brazil: A Daily Gridded Reference Evapotranspiration Data Set for Brazil (2000–2018)
Authors: Althoff Daniel , Dias Santos Henrique Brant , Filgueiras Roberto , Rodrigues Lineu Neiva
Published: June 2020

The reference evapotranspiration (ETo) has long been used as a climate parameter for many studies in climatology and hydrology. However, many regions suffer from shortage of both meteorological monitoring stations and historical information on ETo. Thus, the objective of this study was to develop a daily gridded reference evapotranspiration data set for Brazil that matches the period and grid cells of the Global Precipitation Measurement (GPM) data. ETo was calculated using data from 849 weather stations over the period from 1 June 2000 to 31 December 2018. The features used to model ETo were the GPM daily data set, WorldClim averages monthly, and two engineered features. Among the machine learning algorithms assessed, the Cubist presented the best performance‐computation cost trade‐off in a subset of the entire data and, therefore, was selected to model ETo daily. The developed data set presented root mean square error of 0.65 mm day−1, or 16% lower than previous ETo data set developed for Brazil using interpolation techniques. The GPM and engineered features showed higher importance for the models trained during the wet season, while the WorldClim maximum temperature averages monthly were more important during the dry and cold season. The new gridded reference evapotranspiration data set for Brazil (ETo‐Brazil) was made freely available to the community.
Identification of a novel polymorphism associated with reduced clozapine concentration in schizophrenia patients—a genome-wide association study adjusting for smoking habits
Authors: Smith Robert Løvsletten , O’Connell Kevin , Athanasiu Lavinia , Djurovic Srdjan , Kringen Marianne Kristiansen , Andreassen Ole A. , Molden Espen
Published: June 2020

Clozapine (CLZ) is the superior antipsychotic drug for treatment of schizophrenia, but exhibits an extensive interpatient pharmacokinetic variability. Here, we conducted a genome-wide association study (GWAS) of CLZ serum concentration adjusting for known smoking habits, which is a major nongenetic factor reducing CLZ levels. The study included 484 patients with 10,283 steady-state serum concentrations of CLZ and N-desmethylclozapine, prescribed dosing, co-medications and known smoking habits (n = 422; 9284 serum samples) from a therapeutic drug monitoring (TDM) service. The GWAS analyses were performed with and without smoking habits as covariate, where possible hits were assessed in relation to the target CLZ concentration range applied in the TDM service (300–2500 nmol/L). The smoking-independent analysis of N-desmethylclozapine serum concentration and the CLZ-to-N-desmethylclozapine ratio replicated the previously identified locus on chromosome 4. After adjusting for smoking habits in patients confirmed as ‘smokers’ (61%) or ‘nonsmokers’ (39%), a novel variant (rs28379954; minor T>C allele frequency 4.1%; 7.6% CT carriers in the population) within the gene encoding the nuclear factor 1 B-type (NFIB) was significantly associated with reduced CLZ serum concentration (p = 1.68 × 10−8, beta = −0.376; explained variance 7.63%). There was no significant association between rs28379954 and N-desmethylclozapine concentration in the GWAS analysis (p = 5.63 × 10−5). The fraction of CLZ TDM samples below 300 nmol/L was significantly higher in carriers vs. noncarriers of the rs28379954 minor C allele [12.0% (95% CI: 9.4–14.7) vs. 6.2% (95% CI: 5.7–6.8), p < 0.001]. We identified a novel variant in the NFIB gene associated with reduced CLZ levels and increased risk of subtherapeutic serum concentrations. This warrants testing of clinical relevance of screening for this gene variant, and also experimental studies to investigate the biological mechanisms of NFIB involvement in CLZ pharmacokinetics.
Genomic analysis of primary plasma cell leukemia reveals complex structural alterations and high-risk mutational patterns
Authors: Schinke Carolina , Boyle Eileen M. , Ashby Cody , Wang Yan , Lyzogubov Valeriy , Wardell Christopher , Qu Pingping , Hoering Antje , Deshpande Shayu , Ryan Katie , Thanendrarajan Sharmilan , Mohan Meera , Yarlagadda Naveen , Khan Maliha , Choudhury Samrat Roy , Zangari Maurizio , van Rhee Frits , Davies Faith , Barlogie Bart , Morgan Gareth , Walker Brian A.
Published: June 2020

Primary plasma cell leukemia (pPCL) is a rare and aggressive form of multiple myeloma (MM) that is characterized by the presence of ≥20% circulating plasma cells. Overall survival remains poor despite advances of anti-MM therapy. The disease biology as well as molecular mechanisms that distinguish pPCL from non-pPCL MM remain poorly understood and, given the rarity of the disease, are challenging to study. In an attempt to identify key biological mechanisms that result in the aggressive pPCL phenotype, we performed whole-exome sequencing and gene expression analysis in 23 and 41 patients with newly diagnosed pPCL, respectively. The results reveal an enrichment of complex structural changes and high-risk mutational patterns in pPCL that explain, at least in part, the aggressive nature of the disease. In particular, pPCL patients with traditional low-risk features such as translocation t(11;14) or hyperdiploidy accumulated adverse risk genetic events that could account for the poor outcome in this group. Furthermore, gene expression profiling showed upregulation of adverse risk modifiers in pPCL compared to non-pPCL MM, while adhesion molecules and extracellular matrix proteins became increasingly downregulated. In conclusion, this is one of the largest studies to dissect pPCL on a genomic and molecular level.
The lncRNA RP11-142A22.4 promotes adipogenesis by sponging miR-587 to modulate Wnt5β expression
Authors: Zhang Tongtong , Liu Hongtao , Mao Rui , Yang Huawu , Zhang Yuanchuan , Zhang Yu , Guo Pengsen , Zhan Dafang , Xiang Bin , Liu Yanjun
Published: June 2020

Emerging evidence suggests that long noncoding RNAs (lncRNAs) play essential roles in the regulation of gene expression. However, the functional contributions of lncRNAs to adipogenesis remain largely unexplored. In this study, we investigated global changes in the expression patterns of lncRNAs in visceral adipose tissue and identified RP11-142A22.4 as a significantly upregulated lncRNA. In isolated preadipocytes, knockdown of RP11-142A22.4 inhibited differentiation and reduced C/EBP-α and PPAR-γ expression. Investigations of the underlying mechanisms revealed that RP11-142A22.4 contains a functional miR-587 binding site. Mutation of the binding sites for RP11-142A22.4 in miR-587 abolished the interaction, as indicated by a luciferase reporter assay. Furthermore, RP11-142A22.4 affected the expression of miR-587 and its target gene Wnt5β. Overexpression of miR-587 blocked the inhibitory effect of RP11-142A22.4 on preadipocyte differentiation. Moreover, the downregulation of miR-587 restored preadipocyte differentiation upon inhibition by RP11-142A22.4 silencing. Our results suggest that RP11-142A22.4 can control adipocyte differentiation via the miR-587/Wnt5β signaling pathway and serve as a potential target for obesity treatments.
The role of MDM2–p53 axis dysfunction in the hepatocellular carcinoma transformation
Authors: Cao Hui , Chen Xiaosong , Wang Zhijun , Wang Lei , Xia Qiang , Zhang Wei
Published: June 2020

Liver cancer is the second most frequent cause of cancer-related death globally. The main histological subtype is hepatocellular carcinoma (HCC), which is derived from hepatocytes. According to the epidemiologic studies, the most important risk factors of HCC are chronic viral infections (HBV, HCV, and HIV) and metabolic disease (metabolic syndrome). Interestingly, these carcinogenic factors that contributed to HCC are associated with MDM2–p53 axis dysfunction, which presented with inactivation of p53 and overactivation of MDM2 (a transcriptional target and negative regulator of p53). Mechanically, the homeostasis of MDM2–p53 feedback loop plays an important role in controlling the initiation and progression of HCC, which has been found to be dysregulated in HCC tissues. To maintain long-term survival in hepatocytes, hepatitis viruses have lots of ways to destroy the defense strategies of hepatocytes by inducing TP53 mutation and silencing, promoting MDM2 overexpression, accelerating p53 degradation, and stabilizing MDM2. As a result, genetic instability, chronic ER stress, oxidative stress, energy metabolism switch, and abnormalities in antitumor genes can be induced, all of which might promote hepatocytes’ transformation into hepatoma cells. In addition, abnormal proliferative hepatocytes and precancerous cells cannot be killed, because of hepatitis viruses-mediated exhaustion of Kupffer cells and hepatic stellate cells (HSCs) and CD4+T cells by disrupting their MDM2–p53 axis. Moreover, inefficiency of hepatic immune response can be further aggravated when hepatitis viruses co-infected with HIV. Unlike with chronic viral infections, MDM2–p53 axis might play a dual role in glucolipid metabolism of hepatocytes, which presented with enhancing glucolipid catabolism, but promoting hepatocyte injury at the early and late stages of glucolipid metabolism disorder. Oxidative stress, fatty degeneration, and abnormal cell growth can be detected in hepatocytes that were suffering from glucolipid metabolism disorder, and all of which could contribute to HCC initiation. In this review, we focus on the current studies of the MDM2–p53 axis in HCC, and specifically discuss the impact of MDM2–p53 axis dysfunction by viral infection and metabolic disease in the transformation of normal hepatocytes into hepatoma cells. We also discuss the therapeutic avenues and potential targets that are being developed to normalize the MDM2–p53 axis in HCC.