bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Hypophysectomy on the Occurrence and Calcifiability of Matrix
Vesicles in the Epiphyseal Growth Plate of Immature Rats
Authors: Coleman S. I. , Dougherty W. J. 
Published: June 2020

In the cellular secretion theory of mineral deposition, extracellular
matrix vesicles are believed to play an integral role in hard tissue
mineralization (1). Membrane limited matrix vesicles arise from the plasma
membrane of epiphyseal chondrocytes and tooth odontoblasts by a budding
process (2, 3). Nutritional and hormonal factors have been postulated to
play essential roles in mineral deposition and apparently have a direct
effect on matrix vesicles of calcifying cartilage as concluded by Anderson
and Sajdera (4).
Immature (75-85 gm) Long-Evans hooded rats were hypophysectomized by the
parapharyngeal approach and maintained fourteen (14) days post-surgery. At
this time, the animals were anesthetized and perfusion fixed in cacodylate
buffered 2.5% glutaraldehyde. The proximal tibias were quickly dissected out
and split sagittally. One half was used for light microscopy (LM) and the
other for electron microscopy (EM). The halves used for EM were cut into
blocks approximately 1×3 mm. The tissue blocks were prepared for ultra-thin
sectioning and transmission EM. The tissue was oriented so as to section
through the epiphyseal growth plate from the zone of proliferating cartilage
on down through the hypertrophic zone and into the initial trabecular bone.
Sections were studied stained (double heavy metal) and unstained.
A Rapid Diamond Knife Alignment Procedure
Authors: Heusser Robert C. 
Published: June 2020

The purpose of this paper is to present a rapid and accurate means of
accomplishing two of the more difficult manipulations in diamond knife thin
sectioning, namely precise block align¬ment and advancement of the knife to
a point of contact.
In routine thin sectioning, the desire for serial continuity from a
previously sectioned block is universal. Specialized embedding procedures
such as: tissue culture monolayers, re-sectioning of large plastic sections
and flat embedding molds for specially oriented tissue require extremely
accurate block ori¬entation due to an unusually restricted range of tissue
thick¬ness and critical orientation.
Variations in Sample Preparation that Affect Contrast Enhancement by Lead
Aspartate
Authors: Yoshiyama J.M. , Goff D. , Walton J. 
Published: June 2020

We recently described a new en bloc lead contrast stain for transmission
electron microscopy (Walton, 1979). Several laboratories report great
success with lead aspartate staining but some others have found that its
contrast enhancement is insufficient. We undertook the present study to
determine how differences in sample protocol affect lead aspartate contrast
enhancement, making a strict effort to obtain comparable samples.
Gastrointestinal duodenum provided a tissue of uniform diameter. A 1"
length of duodenum was flushed with warm saline and fixed in 4%
paraformaldehyde-1% glutaraldehyde solution buffered at pH 7.3 with 0.1 M
cacodylate. After a 2 hr fixation period, the sample was cross-sectioned
into blocks 1.0 mm thick. Samples were then post-fixed with 1% osmium
tetroxide buffered with veronal acetate at pH 7.3, washed, stained with lead
aspartate, rinsed, dehydrated, and embedded. Standard staining conditions
were pH 5.5 lead aspartate heated to 60°C for 1 hr. This procedure was
varied by adjusting either the pH of lead aspartate, the staining time, or
the temperature. Additional variations were made in the dehydration times,
osmium fixation times, and choice of wash buffer. Silver sections were cut
from all samples. Micrographs were taken using uniform settings at either
high or low magnifications. All negatives were developed and printed under
the same conditions.
A Simplified Procedure for Critical Point Drying of Dilute Biologic
Suspensions
Authors: Smucker R.A. , Hanson J.M. , Pfister R.M. 
Published: June 2020

Preparations of low concentrations of particulates such as living cells
or inert materials subject to surface alterations due to forces occurring
during dessication may be made with relative ease using the following
techniques.
Working with small quantities of samples which may be essentially a
powder when dry is very difficult. This work describes a technique which
permits processing very small amounts of cells with minimal handling and
loss of starting material. Dialysis tubing preparation was as follows:
Dialysis tubing (9 mm or 10 mm) was soaked in warm double distilled water
for several hours. The softened dialysis tubing was connected to latex
tubing. Ninetyfive percent ETOH was recirculated for two hours through
vertically oriented tubing (0.5 m long) positioned over a beaker so that
ethanol ascended through interior walls of the tubing and overflowed down
the outside walls into the beaker. The ETOH washing was essential to remove
any material absorbed to interior walls of the tubing. After the alcohol
washing, the tubing was rinsed in Millipore filtered double distilled water
several times.
Technique for Obtaining One-Piece Grid-Size Replicas
Authors: Thomas Virginia L. 
Published: June 2020

Obtaining intact replicas from the surface of a desired sample is
frequently difficult. This technique gives a nearly complete replica over
the whole electron microscope grid and can be applied to a wide variety of
samples. Application to tissue culture cells is demonstrated.
Cells were grown to the desired concentration on Thermanox plastic
coverslips (Microbiological Associates, Bethesda, Maryland), fixed,
dehydrated and critical point dried in the Sorval critical point drier. Pt-C
shadow casting and replication were carried out on a Denton DV502 vacuum
evaporator. Replicating was with carbon from two sources and two angles
(∽1:4 and ∽6:1) with sample rotating on a plain rotary stage. Carbon was
evaporated slowly with the pressure maintained at roughly 10∽ by opening and
closing the main valve of the evaporator to cut in the diffusion pump when
the pressure approached 15∽. The lower pressure gives a more uniform
coating.
Atom Motion Observed at Various Temperatures with a Fast Scan
Authors: Hainfeld J. F. , Wall J. 
Published: June 2020

High atomic number atoms can be clearly visualized with a high
resolution STEM (see Fig. 1). Crewe, Isaacson and co-workers first
documented that some atoms moved from one exposure to the next. Previous
results have been extended with the Brookhaven STEM by use of 1) a fast scan
that produces atom images at TV rates, and 2) a temperature controlled stage
that permits observation over a wide range (+30°C to -120°C used in this
report).
A thin carbon substrate (15Å thick) was treated with 0.1% uranyl acetate
for 15 sec. and rinsed 2 times with water. A 32 x 32 scan raster over a 38Å
x 38Å area produced images that were recorded from an oscilloscope display
with a video camera and video tape recorder. The scan rate was 30
frames/sec. A typical dose per frame was 45,000
electrons/A2 at 40 kV.
Radiation Damage in Organic Molecules
Authors: Misra Manoj , Egerton R.F. 
Published: June 2020

Radiation damage is the main limiting factor in attempting high
resolution electron microscopy of biological
macromolecules1,2. To better understand the process
of radiation damage, a systematic study of various amino acids, peptides and
nucleic acid bases has been undertaken.
We report here some preliminary results obtained with glycine,
glycyl-glycine, cystine, cysteine and uracil at room temperature. Specimens
of these compounds were prepared by slow evaporation of their aqueous
solutions (except of glycylglycine which gave better crystals when the
solvent used was N-propanol) on carbon coated grids.
Evidence for Major Cation Deposits at the Exterior Surface of the
Echinoderm EGG
Authors: Decker Glenn L. , Schön Elizabeth A. 
Published: June 2020

As recently reviewed by Scheul and Epel, several studies have documented
the directional flow of different metal ions during echinoderm
fertilization. Little, however, is known about the precise cellular pathways
of calcium or other ions during gamete interaction and
embryogenesis.
In the current study we examine several new fixation approaches which we
hope will lead to localization of the major cations involved in egg
activation and development.
A TEM/STEM Hybrid Scanning Module
Authors: Thompson M.N. 
Published: June 2020

INTRODUCTION
Hybrid scanning modes can be generated by applying the output of the
scan generator of the STEM unit to T.E.M. deflection coils located above or
below the specimen plane. For operator convenience five hybrid modes have
been incorporated in a single module designed for operation with an
EM400T-STEM system.
The modes are subdivided into those based upon the beam scanning
(pivoting) of the illumination and those based upon the beam scanning of the
imaging system. The modes, their associated optics, the location of the scan
pivot point and basic applications are collated in Table 1.
Perinatal maternal undernutrition does not result in offspring capillary rarefaction in the middle-aged male baboon at rest
Authors: Kuo Anderson H. , Li Cun , Huber Hillary F. , Nathanielsz Peter W. , Clarke Geoffrey D. 
Published: June 2020

AbstractMicrovascular health is a main determinant of coronary blood flow reserve and myocardial vascular resistance. Extracardiac capillary abnormality has been reported in subjects at increased coronary heart disease risk, such as prehypertension, hypertension, diabetes, hyperlipidemia, and atherosclerosis. We have reported cardiovascular dysfunction in a cohort of maternal nutrient reduction (MNR)-induced intrauterine growth restriction (IUGR) baboon offspring. Here we test the hypothesis that there is oral capillary rarefaction associated with MNR-induced IUGR. Capillary density was quantified using in vivo high-power capillaroscopy on seven middle-aged (~10.7 yr; human equivalent ~40 yr) male IUGR baboons and seven male age-matched controls in the lateral buccal and inferior labial mucosa. While no difference was found between groups in either area by fraction area or optical density for these vascular beds derived from fetal preductal vessels, further studies are needed on post-ductal vascular beds, retina, and function.
Enhancing Engagement through Job Resources: The Moderating Role of Affective Commitment
Authors: Dominguez Daniel , Chambel María José , Carvalho Vânia Sofia 
Published: June 2020

AbstractResearch has shown that affective commitment, one of three components of organizational commitment defined by Meyer and Allen (1991), can act as a moderator in relationships between job stressors and worker´s psychological tension. However, due to the scarcity of studies that investigate the moderating effect of this commitment component on relationships between positive variables, the purpose of this study is to examine the moderating role of affective commitment in the relationship between autonomy, peer support, supervisory support and perceived organizational support (POS), as job resources, on engagement. In this sense, we analyzed the data provided by a sample of Portuguese employees (N= 554), from an organization belonging to the consultancy sector. Firstly, we aimed to examine the direct effects of those job resources on engagement, and, then, examine the impact of affective commitment as a moderator on these relationships. The results partially support the hypotheses formulated. Indeed, there was a positive relationship between the job resources studied - work autonomy, peer support, supervisory support and POS - and engagement. Furthermore, according to our hypothesis, the interaction established between affective commitment and autonomy, significantly exacerbates the positive effect of this job resource on workers well-being, that is, on their engagement (b= .08,p< .05). However, contrary to our hypothesis, the affective commitment does not moderate the relationship between the other job resources and engagement. This study contributes to a deepest knowledge about the potentialities of affective commitment, reinforcing the importance of consider it as a contextual resource.
Sexual Transgressions in Couples: The Influence of Dependence and Commitment on their Perception and Handling
Authors: Garrido-Macías Marta , Valor-Segura Inmaculada , Expósito Francisca 
Published: June 2020

Abstract
Transgressions occur frequently in romantic relationships, and how they are perceived is influenced by the type of transgression that occurred. By means of an experimental study of 399 participants (75.9% women and 24.1% men) aged 18 to 64 years old (Mage = 31.20, SD = 10.48), we examined the relationship between the type of sexual transgression (infidelity versus coercion), and perceived severity, strategies individuals would use in response to the transgression, and the probability they would leave the relationship, as well as levels of dependence and commitment. Results revealed higher perceived severity (p < .001, η2p = .24) and probability of leaving the relationship (p < .001, η2p = .39) in the infidelity scenario (versus coercion). Meanwhile, women (compared to men) rated sexual transgressions as more severe (p < .001, η2p = .04) and reported a higher probability of leaving the relationship (p < .001, η2p = .03), as well as a higher use of active conflict resolution strategies (exit, p = .048, η2p = .01, and voice, p < .001, η2p = .06) and lower use of passive strategies (loyalty, p < .001, η2p = .08). Finally, high levels of commitment and dependence predicted lower perceived severity (commitment, p < .001, 95% CI [–.72, –.20]; dependence, p < .001, 95% CI [–1.73, –.85]) and lower probability of leaving the relationship (commitment, p = .048, 95% CI [–.55, –.01]; dependence, p < .001, 95% CI [–1.66, –.73]) in coercion (versus infidelity) transgressions. These results highlight the normalization of sexual coercion in romantic relationships, which is not viewed as negatively as infidelity, and that commitment and dependence contribute to minimizing the negative impressions of it.
“It's a Jihad”: Justifying Violence towards the Ahmadiyya in Indonesia
Authors: Burhani Ahmad Najib 
Published: June 2020

AbstractThe concept ofal-wala’ wa-l-bara’(loyalty and disavowal) has become the ideology of modern Salafism; it is used to justify unfriendly relationships with non-Muslims. This concept is usually implemented by reserving love only for fellow Muslims and showing insularity towards non-Muslims. What is the ideological concept that guides some Muslims in their relationship with groups that are considered heretics? This article intends to scrutinize the theological matrix used by vigilante groups in their anti-heresy campaign or attacks on the Ahmadiyya. It also aims to determine why some people believe that persecuting the Ahmadiyya is a theologically justifiable idea. What theological and ideological reasons can be used to justify attacks against the Ahmadiyya community? How do they cope with the conflict between divine law and human/state law? This article argues that instead of feeling guilty, the perpetrators of faith-based violence often feel they have just fulfilled a good religious duty. Committing violence against religious groups deemed heretics is believed to be more thanal-amr bi al-màrūf wa al-nahy `an al-munkar(“commanding right and forbidding wrong”)—it is a jihad. Violence is seen not as an illegal act, but as a “virtue” or an effort to save them from the punishment of God in Hell. In justifying the breaching of state law, the idea of a hierarchy in the law is constructed, i.e. state/human law is hierarchically lower than divine law, so attacking the Ahmadiyya is seen as a transgression of human law for the sake of upholding the divine view.
Dawnside Auroral Polarization Streams
Authors: Liu Jiang , Lyons L. R. , Wang Chih‐Ping , Hairston M. R. , Zhang Yongliang , Zou Ying 
Published: June 2020

AbstractAlthough the postmidnight‐to‐dawn sector of the auroral ionosphere contains interesting dynamic phenomena that may significantly impact the magnetosphere‐ionosphere‐thermosphere system, it has been much less studied than the dusk‐to‐premidnight sector. We discuss a dynamic phenomenon in the postmidnight‐to‐dawn sector of the auroral oval, eastward fast flows mainly within the expanse of the Region 1 current (its part equatorward of the polar cap). These flows peak and have a steep speed gradient (increase from low to high latitude) near the interface between the Region 1 and Region 2 currents. Because such flows correspond to an electric field that most likely comes from enhanced Region 2 currents and an associated spatial conductivity gradient, their generation mechanism is analogous to that of a subauroral polarization stream. Therefore, we refer to such an eastward flow as a dawnside auroral polarization stream (DAPS). We show several examples of the presence and absence of DAPS under different geomagnetic activity levels. A DAPS' electric field can heat the ionosphere (and thus the thermosphere), change the convection pattern of the magnetosphere‐ionosphere system, and modify the drift path of magnetospheric particles. Because a DAPS' flow peak maps to a major site of magnetic‐kinetic energy conversion in the magnetosphere (the transition region between dipole and stretched field), it may be important for the conversion. A DAPS' steep flow gradient is also potentially important; it may lead to instabilities, such as that responsible for auroral Omega bands. Given its potential importance, knowledge of DAPS is fundamental for understanding the magnetosphere‐ionosphere‐thermosphere system.
Realistic Simulation of Tropical Atmospheric Gravity Waves Using Radar‐Observed Precipitation Rate and Echo Top Height
Authors: Bramberger Martina , Alexander M. Joan , Grimsdell Alison W. 
Published: June 2020

AbstractGravity waves (GWs) generated by tropical convection are important for the simulation of large‐scale atmospheric circulations, for example, the quasi‐biennial oscillation (QBO), and small‐scale phenomena like clear‐air turbulence. However, the simulation of these waves still poses a challenge due to the inaccurate representation of convection, and the high computational costs of global, cloud‐resolving models. Methods combining models with observations are needed to gain the necessary knowledge on GW generation, propagation, and dissipation so that we may encode this knowledge into fast parameterized physics for global weather and climate simulation or turbulence forecasting. We present a new method suitable for rapid simulation of realistic convective GWs. Here, we associate the profile of latent heating with two parameters: precipitation rate and cloud top height. Full‐physics cloud‐resolving WRF simulations are used to develop a lookup table for converting instantaneous radar precipitation rates and echo top measurements into a high‐resolution, time‐dependent latent heating field. The heating field from these simulations is then used to force an idealized dry version of the WRF model. We validate the method by comparing simulated precipitation rates and cloud tops with scanning radar observations and by comparing the GW field in the idealized simulations to satellite measurements. Our results suggest that including variable cloud top height in the derivation of the latent heating profiles leads to better representation of the GWs compared to using only the precipitation rate. The improvement is especially noticeable with respect to wave amplitudes. This improved representation also affects the forcing of GWs on large‐scale circulation.
A Semikinetic Model of Plasmasphere Refilling Following Geomagnetic Storms and Comparison With Hydrodynamic Results
Authors: Chatterjee K. , Schunk R. W. 
Published: June 2020

AbstractThe objective of this paper is the development of a kinetic model for plasmasphere refilling following geomagnetic storms. The kinetic model is based on the “particle‐in‐cell” method, a method based on the simulation of particle motion and thus well suited to high altitude, low‐density regimes, where the plasma transport equations are not valid. The model was validated with exact, analytical benchmarks, which are provided in this paper. The refilling results obtained from the kinetic model were then compared with results from a recently developed hydrodynamic solution methodology based on the “flux‐corrected transport” method, and the limitations of hydrodynamic modeling for low‐density flow at high altitudes were explored.
S100A6 is a critical regulator of hematopoietic stem cells
Authors: Grahn Tan Hooi Min , Niroula Abhishek , Végvári Ákos , Oburoglu Leal , Pertesi Maroulio , Warsi Sarah , Safi Fatemeh , Miharada Natsumi , Garcia Sandra C. , Siva Kavitha , Liu Yang , Rörby Emma , Nilsson Björn , Zubarev Roman A. , Karlsson Stefan 
Published: June 2020

AbstractThe fate options of hematopoietic stem cells (HSCs) include self-renewal, differentiation, migration, and apoptosis. HSCs self-renewal divisions in stem cells are required for rapid regeneration during tissue damage and stress, but how precisely intracellular calcium signals are regulated to maintain fate options in normal hematopoiesis is unclear. S100A6 knockout (KO) HSCs have reduced total cell numbers in the HSC compartment, decreased myeloid output, and increased apoptotic HSC numbers in steady state. S100A6KO HSCs had impaired self-renewal and regenerative capacity, not responding to 5-Fluorouracil. Our transcriptomic and proteomic profiling suggested that S100A6 is a critical HSC regulator. Intriguingly, S100A6KO HSCs showed decreased levels of phosphorylated Akt (p-Akt) and Hsp90, with an impairment of mitochondrial respiratory capacity and a reduction of mitochondrial calcium levels. We showed that S100A6 regulates intracellular and mitochondria calcium buffering of HSC upon cytokine stimulation and have demonstrated that Akt activator SC79 reverts the levels of intracellular and mitochondrial calcium in HSC. Hematopoietic colony-forming activity and the Hsp90 activity of S100A6KO are restored through activation of the Akt pathway. We show that p-Akt is the prime downstream mechanism of S100A6 in the regulation of HSC self-renewal by specifically governing mitochondrial metabolic function and Hsp90 protein quality.
Understanding and tuning blue-to-near-infrared photon cutting by the Tm3+/Yb3+ couple
Authors: Yu Dechao , Yu Ting , van Bunningen Arnoldus J. , Zhang Qinyuan , Meijerink Andries , Rabouw Freddy T. 
Published: June 2020

AbstractLanthanide-based photon-cutting phosphors absorb high-energy photons and ‘cut’ them into multiple smaller excitation quanta. These quanta are subsequently emitted, resulting in photon-conversion efficiencies exceeding unity. The photon-cutting process relies on energy transfer between optically active lanthanide ions doped in the phosphor. However, it is not always easy to determine, let alone predict, which energy-transfer mechanisms are operative in a particular phosphor. This makes the identification and design of new promising photon-cutting phosphors difficult. Here we unravel the possibility of using the Tm3+/Yb3+lanthanide couple for photon cutting. We compare the performance of this couple in four different host materials. Cooperative energy transfer from Tm3+to Yb3+would enable blue-to-near-infrared conversion with 200% efficiency. However, we identify phonon-assisted cross-relaxation as the dominant Tm3+-to-Yb3+energy-transfer mechanism in YBO3, YAG, and Y2O3. In NaYF4, in contrast, the low maximum phonon energy renders phonon-assisted cross-relaxation impossible, making the desired cooperative mechanism the dominant energy-transfer pathway. Our work demonstrates that previous claims of high photon-cutting efficiencies obtained with the Tm3+/Yb3+couple must be interpreted with care. Nevertheless, the Tm3+/Yb3+couple is potentially promising, but the host material—more specifically, its maximum phonon energy—has a critical effect on the energy-transfer mechanisms and thereby on the photon-cutting performance.