bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical-vapor deposited ultra-fast diamond detectors for temporal measurements of ion bunches
Authors: Jahn D. , Träger M. , Kis M. , Brabetz C. , Schumacher D. , Blažević A. , Ciobanu M. , Pomorski M. , Bonnes U. , Busold S. , Kroll F. , Brack F.-E. , Schramm U. , Roth M.
Published: September 2018

This article reports on the development of thin diamond detectors and their characterization for their application in temporal profile measurements of subnanosecond ion bunches. Two types of diamonds were used: a 20 μm thin polycrystalline chemical vapor deposited (CVD) diamond and a membrane with a thickness of (5 ± 1) μm etched out of a single crystal (sc) CVD diamond. The combination of a small detector electrode and an impedance matched signal outlet leads to excellent time response properties with a signal pulse resolution (FWHM) of τ = (113 ± 11) ps. Such a fast diamond detector is a perfect device for the time of flight measurements of MeV ions with bunch durations in the subnanosecond regime. The scCVD diamond membrane detector was successfully implemented within the framework of the laser ion generation handling and transport project, in which ion beams are accelerated via a laser-driven source and shaped with conventional accelerator technology. The detector was used to measure subnanosecond proton bunches with an intensity of 108 protons per bunch.
Delayed loss of stability due to the slow passage through Hopf bifurcations in reaction–diffusion equations
Authors: Kaper Tasso J. , Vo Theodore
Published: September 2018

This article presents the delayed loss of stability due to slow passage through Hopf bifurcations in reaction–diffusion equations with slowly-varying parameters, generalizing a well-known result about delayed Hopf bifurcations in analytic ordinary differential equations to spatially-extended systems. We focus on the Hodgkin-Huxley partial differential equation (PDE), the cubic Complex Ginzburg-Landau PDE as an equation in its own right, the Brusselator PDE, and a spatially-extended model of a pituitary clonal cell line. Solutions which are attracted to quasi-stationary states (QSS) sufficiently before the Hopf bifurcations remain near the QSS for long times after the states have become repelling, resulting in a significant delay in the loss of stability and the onset of oscillations. Moreover, the oscillations have large amplitude at onset, and may be spatially homogeneous or inhomogeneous. Space-time boundaries are identified that act as buffer curves beyond which solutions cannot remain near the repelling QSS, and hence before which the delayed onset of oscillations must occur, irrespective of initial conditions. In addition, a method is developed to derive the asymptotic formulas for the buffer curves, and the asymptotics agree well with the numerically observed onset in the Complex Ginzburg-Landau (CGL) equation. We also find that the first-onset sites act as a novel pulse generation mechanism for spatio-temporal oscillations.
Energy loss of Fe ions in He plasmas at different thermodynamic states
Authors: Barriga-Carrasco Manuel D. , González-Gallego Luis , Gil Juan Miguel , Rodríguez Rafael , Espinosa Guadalupe
Published: September 2018

In this work, we analyze the thermodynamic states of the helium plasma and their influence on the stopping power calculations which are needed for obtaining the energy loss of the iron beams traversing them. The analysis is made in ranges of plasma free electron densities (1015–1019 cm−3) and temperatures (1–10 eV) of experiments with iron beams at 6 and 4.3 MeV/u energies. For this purpose, we use Saha-Boltzmann equations for local thermal equilibrium (LTE) and a collisional-radiative model for non-local thermal equilibrium (NLTE) in steady-state situation implemented in a computer code. For the highest temperatures and free electron densities, LTE and NLTE models provide quite similar results for the average ionization and ion abundances. When the opacity effects are taken into account in the NLTE simulations, the optically thick simulations provide fairly similar results to those of the LTE model. The plasma thermodynamic states have a direct impact on the calculation of the energy loss. The differences on the plasma stopping power between considering it in LTE or in NLTE may entail a 10% of the total stopping for the experiments analyzed in the electron density region of 1018–1019 cm−3. These differences can be around 27% for plasmas with smaller electron density of 1017 cm−3 and around 42% for plasmas with an electron density of 1015 cm−3. New experiments would be appreciated to be made in a future to corroborate the latest calculations.
Rationally engineered advances in cancer research
Authors: Engler Adam J. , Discher Dennis E.
Published: September 2018

The physical and engineering sciences have much to offer in understanding, diagnosing, and even treating cancer. Microfluidics, imaging, materials, and diverse measurement devices are all helping to shift paradigms of tumorigenesis and dissemination. Using materials and micro-probes of elasticity, for example, epithelia have been shown to transform into mesenchymal cells when the elasticity of adjacent tissue increases. Approaches common in engineering science enable such discoveries, and further application of such tools and principles will likely improve existing cancer models in vivo and also create better models for high throughput analyses in vitro. As profiled in this special topic issue composed of more than a dozen manuscripts, opportunities abound for the creativity and analytics of engineering and the physical sciences to make advances in and against cancer.
Mode shape construction provides way for understanding of diaphragm resonator damping mechanism
Authors: Liebendorfer Adam
Published: September 2018

A new technique that draws on polynomial functions seeks to streamline calculations on the effects fluid media and thermal stress have on micromechanical and nanomechanical resonators.
Strategies and cost–benefit of selecting for a polled sheep nucleus by using DNA testing
Authors: Granleese T. , Clark S. A. , Duijvesteijn N. , Bradley P. E. , van der Werf J. H. J.
Published: September 2018

The present study assessed the effectiveness and cost–benefit of several genotyping strategies for breeding poll Merino sheep in a closed nucleus with different initial allele frequencies and assuming a single-gene responsible for the horn or poll phenotype. We assumed that selection was based on phenotypes or genotypes for a single gene conferring polledness via a complete-dominance model. Under such a model, a complete fixation of the ‘polled allele’ (P) requires genotyping of the ewe-selection candidates. Testing a higher proportion of female candidates resulted in a faster fixation of the P-allele. Fixation ranged from 1 year of selection with a high starting P-allele frequency of 0.9, to 7 years for low starting P-allele frequencies of 0.3. When premiums of AU$50 or AU$100 were paid for rams with a PP genotype, breeding for PP genotypes was not profitable when the starting P-allele frequency was below 0.7. If the starting allele frequency was above 0.7, net profitability was positive over 10 years when premiums of AU$200 were paid for known PP-genotype rams. While fixing the P-allele, genetic gain for production traits was slowed down in the first 5 years of selection by up to 23% and 3% for initial P allele-frequencies of 0.3 and 0.9 respectively. Lost genetic gain due to fixing the P-allele, which can never be recovered in a closed nucleus, incurred 200–800% higher costs than the DNA testing costs. Rates of genetic gain recovered to pre-P-allele selection level rates of genetic gain once the P-allele was fixed. Testing a maximum of 25% ewe-selection candidates was the least expensive strategy across all starting allele frequencies and premiums. To avoid large losses of genetic gain in a closed nucleus with low P-allele starting frequencies, opening the nucleus should be considered to increase starting P-allele frequencies and also to potentially increase rates of genetic gain to offset the economic loss caused by P-selection.
IL-15 regulates susceptibility of CD4+T cells to HIV infection
Authors: Manganaro Lara , Hong Patrick , Hernandez Matthew M. , Argyle Dionne , Mulder Lubbertus C. F. , Potla Uma , Diaz-Griffero Felipe , Lee Benhur , Fernandez-Sesma Ana , Simon Viviana
Published: September 2018

Significance

HIV creates a persistent reservoir, which is largely resistant to current antiretroviral treatment aimed at inhibiting HIV replication. CD4+T memory lymphocytes, key components of this reservoir, are generally refractory to infection, but stimulation with γc-chain cytokines, such as IL-15, renders these cells more susceptible to HIV. We found that, by inducing cell cycle entry of CD4+T cells, JAK1 is a key mediator responsible for counteracting the antiviral activity of SAM domain and HD domain-containing protein 1 (SAMHD1). Pharmacological inhibition of these kinases resulted in restoration of SAMHD1 in CD4+T cells. Protecting these cells during the critical IL-15 surge observed during primary infection has the potential to limit reservoir establishment.
ERβ-mediated induction of cystatins results in suppression of TGFβ signaling and inhibition of triple-negative breast cancer metastasis
Authors: Reese Jordan M. , Bruinsma Elizabeth S. , Nelson Adam W. , Chernukhin Igor , Carroll Jason S. , Li Ying , Subramaniam Malayannan , Suman Vera J. , Negron Vivian , Monroe David G. , Ingle James N. , Goetz Matthew P. , Hawse John R.
Published: September 2018

Significance

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer and patients exhibit high rates of recurrence and mortality in part due to lack of treatment options beyond standard-of-care chemotherapy regimens. In the subset of TNBCs that express estrogen receptor beta (ERβ), ligand-mediated activation of ERβ elicits potent anticancer effects. We report here the elucidation of the ERβ cistrome and transcriptome in TNBC and identify a mechanism whereby ERβ induces cystatin gene expression resulting in inhibition of canonical TGFβ signaling and a blockade of metastatic phenotypes. These findings suggest that ERβ-targeted therapies represent a treatment option for the subset of women with ERβ-expressing TNBC.
Pharmacological bypass of NAD
+
salvage pathway protects neurons from chemotherapy-induced degeneration
Authors: Liu Hui-wen , Smith Chadwick B. , Schmidt Mark S. , Cambronne Xiaolu A. , Cohen Michael S. , Migaud Marie E. , Brenner Charles , Goodman Richard H.
Published: September 2018

Significance

Axon degeneration is caused by multiple chemotherapeutic agents and is a hallmark of chemotherapy-induced peripheral neuropathy (CIPN). CIPN is associated with the loss of the essential metabolite nicotinamide adenine dinucleotide (NAD
+
), a vital metabolite involved in energy homeostasis, but whether NAD
+
loss or the accumulation of an NAD
+
precursor, nicotinamide mononucleotide (NMN), is responsible for axon degeneration is controversial. We found that axon degeneration caused by vincristine, a widely used chemotherapeutic agent, could be ameliorated by forcing peripheral neurons to use an NAD
+
biosynthetic pathway that bypasses NMN formation. This strategy provides an approach for preventing CIPN.
Cochaperone Mzb1 is a key effector of Blimp1 in plasma cell differentiation and β1-integrin function
Authors: Andreani Virginia , Ramamoorthy Senthilkumar , Pandey Abhinav , Lupar Ekaterina , Nutt Stephen L. , Lämmermann Tim , Grosschedl Rudolf
Published: September 2018

Significance

Antibody-secreting plasma cells are effectors of the humoral immune response. Transcription factor Blimp1 (Prdm1) is essential for the generation and function of plasma cells, and it regulates many genes, including
Mzb1
(
pERp1
). Mzb1 protein is localized in the endoplasmic reticulum and acts as a cochaperone for the substrate-specific chaperone Grp94 (gp96). By the analysis of
Mzb1

−/−

Prdm1

+/gfp

mice, we find that Mzb1 is required for T cell-independent immune responses and differentiation of plasma cells. In
Mzb1

−/−

Prdm1

+/gfp

mice, we also observe impaired β1-integrin activation and trafficking of plasma cells to the bone marrow. Notably, we show that Mzb1 accounts for many of the Blimp1-associated downstream functions, suggesting that Mzb1 is a key effector of the Blimp1 regulatory network in plasma cells.
ATP hydrolysis-coupled peptide translocation mechanism of
Mycobacterium tuberculosis
ClpB
Authors: Yu Hongjun , Lupoli Tania J. , Kovach Amanda , Meng Xing , Zhao Gongpu , Nathan Carl F. , Li Huilin
Published: September 2018

Significance

The
Mycobacterium tuberculosis
(
Mtb
) ClpB is a ring-shaped, ATP-driven disaggregase. The ability to rescue aggregated proteins is crucial for
Mtb
to grow and persist in the host. Despite extensive studies in the past two decades, it is still not well understood how a bacterial disaggregase couples ATP binding and hydrolysis to peptide translocation. Our cryo-EM study of the
Mtb
ClpB in the presence of a peptide substrate and the slowly hydrolysable adenosine 5′-[γ-thio]triphosphate revealed two active conformations in the midst of the substrate-threading process. This, together with the resolved nucleotide state in each of the 12 nucleotide-binding domains of the ClpB hexamer, helps define a detailed atomic trajectory that couples ATP binding and hydrolysis to mechanical protein translocation.
Merchants to the Golden City: The PersianFarmānof King Chandrawizaya Rājā and the Elephant and Ivory Trade in the Indian Ocean, a View from 1728
Authors: Khazeni Arash
Published: September 2018

This paper provides a translation and analysis of Sloane Mss. 3259 in the British Library, a Persian farmān from the court of King Chandrawizaya Rājā in the Arakanese Kingdom of Mrauk U (1429−1784). Written in 1728 and addressed to the Armenian merchant Khwājeh Georgin of the port of Chennaipattana across the Bay of Bengal in India, the decree is a permit for the lucrative trade in elephants and ivory from the forests of Arakan. The royal decree reveals the presence of Persian as a mutual language of encounter, exchange, diplomacy, and correspondence in eighteenth-century Southeast Asia. Through the manuscript, a view emerges of a sovereign forest kingdom of manifold rarities at the margins of the Persianate and Mughal worlds.
Analysis of running stability during 5000 m running*
Authors: Hoenig Tim , Hamacher Daniel , Braumann Klaus‐Michael , Zech Astrid , Hollander Karsten
Published: September 2018

In the analysis of human walking, the assessment of local dynamic stability (LDS) has been widely used to determine gait stability. To extend the concepts of LDS to the analysis of running biomechanics, this study aimed to compare LDS during exhaustive running between competitive and recreational runners. Fifteen recreational and fifteen competitive runners performed an exhaustive 5000 m run. Inertial measurement units at foot, pelvis, and thorax were used to determine local dynamic running stability as quantified by the largest Lyapunov exponent. In addition, we measured running velocity, lactate levels, perceived exertion, and foot strike patterns. LDS at the start, mid, and end of a 5000 m run was compared between the two groups by a two‐way repeated‐measures analysis of variance (ANOVA). Local dynamic stability increased during the run (thorax, pelvis) in both recreational and competitive runners (PThorax = 0.006; PPelvis = 0.001). During the whole run, competitive runners showed a significantly higher LDS (P = 0.029) compared to recreational runners at the foot kinematics. In conclusion, exhaustive running can lead to improvements in LDS, indicating a higher local dynamic stability of the running technique with increasing exhaustion. Furthermore, LDS of the foot differs between the two groups at all measurement points. The results of this study show the value of determining LDS in athletes as it can give a better understanding into the biomechanics of running.
‘Race was a motivating factor’: re-segregated schools in the American states
Authors: Johnson Richard , King Desmond
Published: September 2018

During the Obama presidency, Republicans made major gains in state legislative elections, especially in the South and the Midwest. Republicans’ control grew from 13 legislatures in 2009 to 32 in 2017. A major but largely unexamined consequence of this profound shift in state-level partisan control was the resurgence of efforts to re-segregate public education. We examine new re-segregation policies, especially school district secession and anti-busing laws, which have passed in these states. We argue that the marked reversal in desegregation patterns and upturn in re-segregated school education is part of the Republican Party's anti-civil rights and anti-federal strategies, dressed up in the ideological language of colour-blindness.
A Darboux theorem for derived schemes with shifted symplectic structure
Authors: Brav Christopher , Bussi Vittoria , Joyce Dominic
Published: September 2018

We prove a Darboux theorem for derived schemes with symplectic forms of degree

k
>
0

k>0

, in the sense of Pantev, Toën, Vaquié, and Vezzosi. More precisely, we show that a derived scheme

X

\mathbfit {X}

with symplectic form

ω
~

\tilde {\omega }

of degree

k
k

is locally equivalent to

(
Spec
⁡
A
,
ω
)

(\operatorname {Spec} A,\omega )

for

Spec
⁡
A

\operatorname {Spec} A

an affine derived scheme in which the cdga

A
A

has Darboux-like coordinates with respect to which the symplectic form

ω
\omega

is standard, and in which the differential in

A
A

is given by a Poisson bracket with a Hamiltonian function

Φ
\Phi

of degree

k
+
1

k+1

.

When

k
=
−
1

k=-1

, this implies that a

−
1

-1

-shifted symplectic derived scheme

(

X

,

ω
~

)

(\mathbfit {X}, \tilde {\omega })

is Zariski locally equivalent to the derived critical locus

Crit
⁡
(
Φ
)

\operatorname {Crit}(\Phi )

of a regular function

Φ
:
U
→

A

1

\Phi :U\rightarrow \mathbb {A}^1

on a smooth scheme

U
U

. We use this to show that the classical scheme

X
=

t
0

(

X

)

X=t_0(\mathbfit {X})

has the structure of an algebraic d-critical locus, in the sense of Joyce.

In a series of works, the authors and their collaborators extend these results to (derived) Artin stacks, and discuss a Lagrangian neighbourhood theorem for shifted symplectic derived schemes, and applications to categorified and motivic Donaldson–Thomas theory of Calabi–Yau 3-folds, and to defining new Donaldson–Thomas type invariants of Calabi–Yau 4-folds, and to defining Fukaya categories of Lagrangians in algebraic symplectic manifolds using perverse sheaves.
Exponential self-similar mixing by incompressible flows
Authors: Alberti Giovanni , Crippa Gianluca , Mazzucato Anna
Published: September 2018

We study the problem of the optimal mixing of a passive scalar under the action of an incompressible flow in two space dimensions. The scalar solves the continuity equation with a divergence-free velocity field, which satisfies a bound in the Sobolev spaceWs,pW^{s,p}, wheres≥0s \geq 0and1≤p≤∞1\leq p\leq \infty. The mixing properties are given in terms of a characteristic length scale, called the mixing scale. We consider two notions of mixing scale, one functional, expressed in terms of the homogeneous Sobolev norm H˙−1\dot H^{-1}, the other geometric, related to rearrangements of sets. We study rates of decay in time of both scales under self-similar mixing. For the case s=1s=1and1≤p≤∞1 \leq p \leq \infty(including the case of Lipschitz continuous velocities and the case of physical interest of enstrophy-constrained flows), we present examples of velocity fields and initial configurations for the scalars that saturate the exponential lower bound, established in previous works, on the time decay of both scales. We also present several consequences for the geometry of regular Lagrangian flows associated to Sobolev velocity fields.
Some examples of composition operators and their approximation numbers on the Hardy space of the bidisk
Authors: Li Daniel , Queffélec Hervé , Rodríguez-Piazza Luis
Published: September 2018

We give examples of composition operatorsCΦC_\PhionH2(D2)H^2 ({\mathbb D}^2)showing that the condition‖Φ‖∞=1\|\Phi \|_\infty = 1is not sufficient for their approximation numbersan(CΦ)a_n (C_\Phi )to satisfy<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="limit Underscript n right-arrow normal infinity Endscripts left-bracket a Subscript n Baseline left-parenthesis upper C Subscript normal upper Phi Baseline right-parenthesis right-bracket Superscript 1 slash StartRoot n EndRoot Baseline equals 1">limn→∞[an(CΦ)]1/n=1\lim _{n \to \infty } [a_n (C_\Phi ) ]^{1/\sqrt {n}} = 1, contrary to the11-dimensional case. We also give a situation where this implication holds. We make a link with the Monge–Ampère capacity of the image ofΦ\Phi.
How to design an optimal sensor network for the unfolded protein response
Authors: Stroberg Wylie , Aktin Hadar , Savir Yonatan , Schnell Santiago
Published: September 2018

Cellular protein homeostasis requires continuous monitoring of stress in the endoplasmic reticulum (ER). Stress-detection networks control protein homeostasis by mitigating the deleterious effects of protein accumulation, such as aggregation and misfolding, with precise modulation of chaperone production. Here, we develop a coarse model of the unfolded protein response in yeast and use multi-objective optimization to determine which sensing and activation strategies optimally balance the trade-off between unfolded protein accumulation and chaperone production. By comparing a stress-sensing mechanism that responds directly to the level of unfolded protein in the ER to a mechanism that is negatively regulated by unbound chaperones, we show that chaperone-mediated sensors are more efficient than sensors that detect unfolded proteins directly. This results from the chaperone-mediated sensor having separate thresholds for activation and deactivation. Finally, we demonstrate that a sensor responsive to both unfolded protein and unbound chaperone does not further optimize homeostatic control. Our results suggest a strategy for designing stress sensors and may explain why BiP-mitigated ER stress-sensing networks have evolved.
Compressive force induces reversible chromatin condensation and cell geometry–dependent transcriptional response
Authors: Damodaran Karthik , Venkatachalapathy Saradha , Alisafaei Farid , Radhakrishnan A. V. , Sharma Jokhun Doorgesh , Shenoy Vivek B. , Shivashankar G. V.
Published: September 2018

Fibroblasts exhibit heterogeneous cell geometries in tissues and integrate both mechanical and biochemical signals in their local microenvironment to regulate genomic programs via chromatin remodelling. While in connective tissues fibroblasts experience tensile and compressive forces (CFs), the role of compressive forces in regulating cell behavior and, in particular, the impact of cell geometry in modulating transcriptional response to such extrinsic mechanical forces is unclear. Here we show that CF on geometrically well-defined mouse fibroblast cells reduces actomyosin contractility and shuttles histone deacetylase 3 (HDAC3) into the nucleus. HDAC3 then triggers an increase in the heterochromatin content by initiating removal of acetylation marks on the histone tails. This suggests that, in response to CF, fibroblasts condense their chromatin and enter into a transcriptionally less active and quiescent states as also revealed by transcriptome analysis. On removal of CF, the alteration in chromatin condensation was reversed. We also present a quantitative model linking CF-dependent changes in actomyosin contractility leading to chromatin condensation. Further, transcriptome analysis also revealed that the transcriptional response of cells to CF was geometry dependent. Collectively, our results suggest that CFs induce chromatin condensation and geometry-dependent differential transcriptional response in fibroblasts that allows maintenance of tissue homeostasis.
Essential requirement of mammalianPumiliofamily in embryonic development
Authors: Lin Kaibo , Zhang Shikun , Shi Qinghua , Zhu Mengyi , Gao Liuze , Xia Wenjuan , Geng Baobao , Zheng Zimeng , Xu Eugene Yujun
Published: September 2018

Mouse PUMILIO1 (PUM1) and PUMILIO2 (PUM2) belong to the PUF (Pumilio/FBF) family, a highly conserved RNA binding protein family whose homologues play critical roles in embryonic development and germ line stem cell maintenance in invertebrates. However, their roles in mammalian embryonic development and stem cell maintenance remained largely uncharacterized. Here we report an essential requirement of the Pum gene family in early embryonic development. A loss of both Pum1 and Pum2 genes led to gastrulation failure, resulting in embryo lethality at E8.5. Pum-deficient blastocysts, however, appeared morphologically normal, from which embryonic stem cells (ESCs) could be established. Both mutant ESCs and embryos exhibited reduced growth and increased expression of endoderm markers Gata6 and Lama1, making defects in growth and differentiation the likely causes of gastrulation failure. Furthermore, ESC Gata6 transcripts could be pulled down via PUM1 immunoprecipitation and mutation of conserved PUM-binding element on 3′UTR (untranslated region) of Gata6 enhanced the expression of luciferase reporter, implicating PUM-mediated posttranscriptional regulation of Gata6 expression in stem cell development and cell lineage determination. Hence, like its invertebrate homologues, mouse PUM proteins are conserved posttranscriptional regulators essential for embryonic and stem cell development.
A patient-derived cellular model for Huntington’s disease reveals phenotypes at clinically relevant CAG lengths
Authors: Hung Claudia Lin-Kar , Maiuri Tamara , Bowie Laura Erin , Gotesman Ryan , Son Susie , Falcone Mina , Giordano James Victor , Gillis Tammy , Mattis Virginia , Lau Trevor , Kwan Vickie , Wheeler Vanessa , Schertzer Jonathan , Singh Karun , Truant Ray
Published: September 2018

The huntingtin protein participates in several cellular processes that are disrupted when the polyglutamine tract is expanded beyond a threshold of 37 CAG DNA repeats in Huntington’s disease (HD). Cellular biology approaches to understand these functional disruptions in HD have primarily focused on cell lines with synthetically long CAG length alleles that clinically represent outliers in this disease and a more severe form of HD that lacks age onset. Patient-derived fibroblasts are limited to a finite number of passages before succumbing to cellular senescence. We used human telomerase reverse transcriptase (hTERT) to immortalize fibroblasts taken from individuals of varying age, sex, disease onset, and CAG repeat length, which we have termed TruHD cells. TruHD cells display classic HD phenotypes of altered morphology, size and growth rate, increased sensitivity to oxidative stress, aberrant adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratios, and hypophosphorylated huntingtin protein. We additionally observed dysregulated reactive oxygen species (ROS)-dependent huntingtin localization to nuclear speckles in HD cells. We report the generation and characterization of a human, clinically relevant cellular model for investigating disease mechanisms in HD at the single-cell level, which, unlike transformed cell lines, maintains functions critical for huntingtin transcriptional regulation and genomic integrity.
Press Subsidies
Authors: Ots Mart , Picard Robert G.
Published: September 2018

Due to its function as a watchdog or fourth estate in democratic societies and a variety of commercial challenges, policy-makers have undertaken initiatives to support the production and distribution of news. Press subsidies are one such policy initiative that particularly aims to provide support to private news producers. Paid as direct cash handouts or indirect reduced taxes and fees, they exist in some form in almost every country in the world. Subsidies are not uncontroversial, their effectiveness is unclear, and their magnitude, designs, and areas of application, differ across nations and their unique economic, cultural, and political contexts.

After periods of declining political and public interest in media subsidies, the recent economic crisis of journalism, and the rising influence of various forms of click-bait, fake, native, or biased news on social media platforms, has brought state support of original journalism back on the agenda.
Government Legitimacy and Religion
Authors: Hoffman Michael
Published: September 2018

Despite the predictions of Marxists and secularization theorists alike, the relationship between religion and government legitimacy is mixed. Religion, in its various forms, can serve to promote regimes of virtually any type—democratic or otherwise—and can just as easily undermine such regimes. Observers hoping for a one-size-fits-all account of the link between religion and legitimacy will surely be disappointed; the reality is far more complicated. Religion, encompassing a nearly infinite variety of beliefs, behaviors, and actors, exercises a diverse set of influences on its political context. For regimes, this diversity can be either helpful or dangerous. Religion is neither inherently pro-status quo nor revolutionary; it can be either one depending on the context. Likewise, religion is neither necessarily pro- nor anti-democratic. Political and theological conditions influence the ways in which religion interacts with politics, and in particular, the role it plays in building or undermining legitimacy.

Twenty-first-century research highlights the Janus-faced relationship between religion and political legitimacy. In some settings, religion has been the foundation of non-democratic rule. In others, it has been a crucial catalyst for unseating dictators in favor of democratic alternatives. Theological differences can only explain part of this variation. The same religious tradition may serve as a defense of authoritarianism in one instance but a spark for democracy in another. Political factors play a key role in explaining why religion sometimes supports the status quo but in other instances may fuel revolutionary fervor.
Transnational Curriculum Formation and Change
Authors: Gough Noel
Published: September 2018

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Education. Please check back later for the full article.

Although much curriculum work continues to take place within national borders (often informed by governmental policies and priorities), accelerating processes of economic and cultural globalization, together with an increase in various types of cross-border movements of people, resources, ideas, and images, are blurring nation-state boundaries and destabilizing national authority in curriculum decision-making.

Typically, transnational work is understood as acting across national borders with a view to optimizing the interrelationships between local, national, regional, and global spheres of curriculum formation and change. This is distinguished from international collaboration (actions taken by conventional nation-states) and supranational work, which includes initiatives and interventions by broader global institutions and nongovernmental organizations (NGOs) such as the International Monetary Fund (IMF), the World Bank, UNESCO, OECD, and so on. The involvement of supranational institutions such as the World Bank and IMF has tended to support curriculum policies derived from neoliberal economic perspectives, which focus on the measurable production of human capital. Transnational curriculum work encourages critical examination of the impact of globalization in relation to national and international debates on such matters as human rights; social justice; democratization; national, ethnic, and religious identities; issues of gender and racial justice; the concerns of indigenous peoples; and poverty and social exclusion. Transnational curriculum work is also a response to the discourses of standardization and homogenization of curriculum thinking that characterize modern nation-states.
Community-Engaged Teacher Preparation
Authors: Zygmunt Eva , Cipollone Kristin , Clark Patricia , Tancock Susan
Published: September 2018

Community-engaged teacher preparation is an innovative paradigm through which to prepare socially just, equity-focused teachers with the capacity to enact pedagogies that are culturally relevant, responsive, and sustaining. Operationalized through candidates’ situated learning in historically marginalized communities, this approach emphasizes the concerted cultivation of collaborative relationships among universities, communities, and schools; the elevation of funds of knowledge and community cultural wealth; and an in-depth analysis of social inequality and positionality, and the intersections between the two, as essential knowledge for future teachers. As a means through which to address the persistent achievement gap between racially, socioeconomically, and linguistically nondominant and dominant students, community-engaged teacher preparation is a prototype through which to advance educational equity.
Epistemology and Teacher Education
Authors: Smith Matthew
Published: September 2018

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Education. Please check back later for the full article.

For teachers to effectively engage in given pedagogical practices, they need to have beliefs that support these approaches to teaching. These are not philosophical beliefs per se; rather, they are the individual understandings that teachers hold about the nature of knowledge and knowing, which underpin and guide their actions and which are referred to as personal epistemologies. A wide range of paradigms for understanding and studying personal epistemologies is evident in the research literature in this field, but these different perspective and approaches—while varied in outlook and conclusion—point to how important it is that initial teacher education courses allow for the development of sophisticated personal epistemologies through explicit teaching that enables students to think ontologically and epistemologically, and that teacher educators initiate and sustain reflective and discursive practices throughout their courses to promote the best possible outcomes for the children that student teachers will go on to teach in their subsequent careers.
The History of Motorization in Japan
Authors: Townsend Susan
Published: September 2018

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Asian History. Please check back later for the full article.

In 1907 the first Japanese-made motorcar was unveiled. A century later, the phenomenon of kuruma banare [車離れ], literally “turning one’s back on the car,” but often translated as “de-motorization,” appeared in the international press. Falling sales suggested that Japan’s domestic car market had reached full capacity reversing an almost continuous historical trend of increasing car ownership. In the 1960s and 1970s, personal car ownership changed the social and cultural fabric of everyday life and transformed the urban environment and landscape. However, the automobile also became the focus of anxieties about traffic congestion, air pollution, noise levels, and safety and by the end of the 20th century was seen as ultimately damaging to community, social harmony, and the environment. While reports of the death of the motorcar turned out to be exaggerations, Japan became the “Asian pathfinder” for setting ultimate limits for the growth of fossil-fueled automobiles worldwide. Historiographically, the focus on the astounding success of Japan’s major automobile manufacturers in international markets drew attention away from the social and cultural history of the car itself in Japan. Yet the story of how Japan was transformed from an essentially wheel-less society at the dawn of the 20th century into the first industrial power to have achieved almost full-capacity car ownership is no less remarkable and sheds light on current dilemmas surrounding car use and sustainability in developing countries such as China and India.
Predictive Regressions
Authors: Gonzalo Jesús , Pitarakis Jean-Yves
Published: September 2018

Predictive regressions are a widely used econometric environment for assessing the predictability of economic and financial variables using past values of one or more predictors. The nature of the applications considered by practitioners often involve the use of predictors that have highly persistent, smoothly varying dynamics as opposed to the much noisier nature of the variable being predicted. This imbalance tends to affect the accuracy of the estimates of the model parameters and the validity of inferences about them when one uses standard methods that do not explicitly recognize this and related complications. A growing literature aimed at introducing novel techniques specifically designed to produce accurate inferences in such environments ensued. The frequent use of these predictive regressions in applied work has also led practitioners to question the validity of viewing predictability within a linear setting that ignores the possibility that predictability may occasionally be switched off. This in turn has generated a new stream of research aiming at introducing regime-specific behavior within predictive regressions in order to explicitly capture phenomena such as episodic predictability.
Submillimetre dust polarization and opacity in the HD163296 protoplanetary ring system
Authors: Dent W R F , Pinte C , Cortes P C , Ménard F , Hales A , Fomalont E , de Gregorio-Monsalvo I
Published: September 2018

We present ALMA images of the sub-mm continuum polarization and spectral index of the protoplanetary ringed disc HD163296. The polarization fraction at 870 µm is measured to be ∼0.9 per cent in the central core and generally increases with radius along the disc major axis. It peaks in the gaps between the dust rings, and the largest value (∼4 per cent) is found between rings 1 and 2. The polarization vectors are aligned with the disc minor axis in the central core, but become more azimuthal in the gaps, twisting by up to ±9° in the gap between rings 1 and 2. These general characteristics are consistent with a model of self-scattered radiation in the ringed structure, without requiring an additional dust alignment mechanism. The 870/1300 µm dust spectral index exhibits minima in the centre and the inner rings, suggesting these regions have high optical depths. However, further refinement of the dust or the disc model at higher resolution is needed to reproduce simultaneously the observed degree of polarization and the low spectral index.
External Governance and Debt Structure
Authors: Bharath Sreedhar T , Hertzel Michael
Published: September 2018

This paper examines how external governance pressure affects the type of debt that firms issue. Consistent with a governance mechanism substitution effect, we find that an exogenous increase (decrease) in governance pressure from the product (takeover) market has a significant negative (positive) impact on the use of bank (public debt) financing over public debt (bank loan) issuance. Tests using changes in the strictness of loan covenants provide corroborative evidence. These findings are consistent with the notion that firms endogenously substitute governance mechanisms and that demand for creditor governance depends on the relative strength of alternative external governance mechanisms.

Received May 18, 2016; editorial decision November 11, 2017 by Editor David Denis.
An Analysis of the Nulliparous, Term, Singleton, Vertex Cesarean Birth Rate Among Practice Groups in a High-Volume Community Teaching Hospital
Authors: Wang Tiffany , Kawakita Tetsuya , Fernandez Miguel , Tefera Eshetu , Fernandez Stephen , Moxley Michael
Published: September 2018

PURPOSE:

Data regarding factors that influence the nulliparous, term, singleton, vertex (NTSV) cesarean birth rate is limited. This study's purpose was to compare the NTSV cesarean rate across practice groups at Virginia Hospital Center (VHC).

BACKGROUND:

VHC is a high-volume community teaching hospital in Arlington, Virginia. Labor and Delivery is managed by different practice groups: hospitalists with resident coverage, hospitalists without resident coverage, and private attendings. Hospitalists are attending physicians who provide 24-hour in-house management of laboring patients, whereas private attendings are only expected to be in-house for patients in active labor.

METHODS:

This was a retrospective cohort study of all NTSV pregnant women who delivered at VHC from 2014 to 2016. Chi-square tests were used to determine whether NTSV cesarean rates were significantly different over time and across different practice groups.

RESULTS:

There were 2,339, 2,090, and 1,673 NTSV pregnancies in 2014, 2015, and 2016, respectively. The NTSV cesarean rate decreased significantly by 30.8% (31.8% in 2014, 27.7% in 2015, and 22.0% in 2016, 0.01). The NTSV cesarean rate was significantly lower with hospitalists, with the lowest rate in the hospitalists with resident coverage (NTSV rate of 19.8% for hospitalists plus residents, 25.7% for hospitalists without residents, 30.3% for private attendings, 0.01). All groups decreased their NTSV cesarean birth rate over time, with significant decreases in the hospitalists without residents and private attending groups (0.01).

DISCUSSION:

Having 24-hour in-house attending coverage is associated with lower NTSV cesarean rates. Resident involvement may also be a factor in lowering this rate.
Teaching Wellness Skills: Effect of a Curriculum Designed to Increase Physician Resilience on Obstetrics and Gynecology Intern Burnout, Mindfulness and Self-compassion
Authors: Fitzmaurice Laura , Peterson Brennan , Boehm Julia
Published: September 2018

PURPOSE:

To assess whether a curriculum targeting psychological resilience impacts the burnout, mindfulness and self-compassion of obstetrics and gynecology interns.

BACKGROUND:

Physician burnout impacts more than half of obstetrician/gynecologists nationwide. One strategy to reduce burnout is to improve individual physicians' resiliency through cognitive and behavioral strategies linked to wellness in other populations.

METHODS:

A prospective, longitudinal cohort, mixed-methods evaluation of a 12-hour curriculum taught to a residency class of seven obstetrics and gynecology interns was conducted using paired, de-identified, pre- and post-curriculum assessments of Maslach Burnout Inventory (MBI), Five Facets of Mindfulness Questionnaire (FFMQ) and Self-Compassion Scale for Researchers (SCS) scores. Data were analyzed descriptively looking primarily at changes in paired scores. A post-curriculum focus group was conducted to further investigate curriculum acceptance and impact.

RESULTS:

Burnout exhaustion and depersonalization scores increased following the curriculum (median difference 3 and 3, respectively). FFMQ and SCS scores also increased (median difference 20 and 7, respectively). Focus group findings suggested interns valued the curriculum, but described an acute increase in distress as they were taken out of their prior “just powering through” coping strategy.

DISCUSSION:

A wellness curriculum targeting improved resident resilience was associated with an acute worsening of burnout, but with short-term improvements in mindfulness and self-compassion, both of which have been associated with improved well-being and resilience in other populations. Worsened burnout may have been a result of increased awareness of uncomfortable thoughts and feelings. Extensive further research is needed on how to develop and measure physician resilience, including long-term implications of improved mindfulness and self-compassion.
The Impact of a Structured Wellness Curriculum on Burnout Among Obstetrics and Gynecology Residents
Authors: Tedrick Laura , Lawrence Elizabeth , Stonehocker Jody , Crawley Ashlee , Jeppson Peter
Published: September 2018

PURPOSE:

Our primary aim was to evaluate the effects of a formalized wellness curriculum on the rate of burnout among University of New Mexico (UNM) obstetrics and gynecology (OBGyn) residents. Our secondary aim was to evaluate the effect of a wellness curriculum on rates of depression, alcohol abuse and suicide risk.

BACKGROUND:

Burnout is a pathological syndrome characterized by depersonalization, emotional exhaustion and a low sense of personal achievement. Burnout is a concern for resident physicians due to their heavy workload and low sense of autonomy.

METHODS:

A structured wellness curriculum was instituted at the start of the 2016 academic year. A 45-item survey, consisting of the Maslach Burnout Inventory Human Services Survey (MBI-HSS), personal health questionnaire-9 (PHQ9), suicide behaviors questionnaire-revised (SBQr), and the alcohol use disorders identification test (AUDIT), was to be administered at the start, midpoint, and end of the academic year.

RESULTS:

The study included 23 UNM OBGyn residents. Midpoint and end of curriculum surveys were collected as planned and demonstrated no difference in rate of burnout. Upon completion of the 2016 academic year 18 (78.2%) residents reported moderate to severe emotional exhaustion; 13 (59.1%) moderate to severe depersonalization; and 5 (21.7%) low personal achievement. SBQ-R identified 4 (18.2%) residents at high risk for suicide and AUDIT-C identified 15 (68.2%) at high risk for alcohol abuse.

DISCUSSION:

High rates of burnout, depression, alcohol abuse, and suicide risk did not change between the midpoint and end of a structured wellness curriculum.
Ultrasound Training in Obstetrics and Gynecology Residency: A National Portrait
Authors: Doyle Nora
Published: September 2018

PURPOSE:

To understand current training in obstetric and gynecologic ultrasound.

BACKGROUND:

Modern obstetrics and gynecology practice requires the frequent use of ultrasound (US) and therefore US training has become an important part of resident education. We sought to understand how residents are currently being trained in obstetric and gynecologic US by surveying residency program directors.

METHODS:

We developed a 36 item self-administered questionnaire targeted for residency program directors (PD). PD from all 261 accredited programs were invited to participate. We inquired about US curriculums, time spent in US training, types of US taught, learning environments and instructors, feedback regarding resident competence and resident input of the learning experience. IRB approval was obtained prior to study onset.

RESULTS:

We received 108 completed responses. PD from all geographical US areas and Canada responded. PD self-described their programs as 52% university based, 28% community based, 18% combination of university/community based and 2% military. Over 65% reported US education was built into the curriculum as a distinct rotation. Of the US rotations >50% were described as a one month separate block. 40% stated 1–4 hours week devoted to US education. 99% said supervised instruction was the norm with the majority of teachers being MFM physicians/sonographers. A mixture of observational and hands-on ultrasound experience is the norm for most programs. Over 76% PD gave residents US reading assignments and have formal lectures, mostly by MFM and REI faculty. Less than 20% of programs supported any experience with ultrasound simulator training. 90% of PD give formal feedback to the residents about their skills. Only 69% state that their residents can evaluate the learning experience.

DISCUSSION:

We recount details of the current status of US education in OB/Gyn residency programs as reported by PD across the country. Our questions were designed to understand the amount of time actually committed to ultrasound education. With the inception of widespread US need in the daily life of obstetrics and gynecology the challenge of ensuring adequate resident training exists. More structure and protected learning time may assist in resident training. Simulator training for US education seems underutilized.