bluuebunny/crossref_metadata_2025 huggingface dataset:
Studying micro dynamics in civil wars: introduction
Authors: Haer Roos , Vüllers Johannes , Weidmann Nils B.
Published: November 2019

This article introduces the special issue on the micro-level dynamics of civil wars. Until recently, most empirical work on these conflicts and their consequences has focused on the level of the sovereign state. In contrast, a micro-level approach is categorized by three distinct—albeit intertwined—features: a disaggregation by actors, time and space, interdisciplinarity, and the reliance on a set of different methods for the collection of data. The contributors to this special issue illustrate different approaches to the study of micro-level dynamics. The first part of the Special Issue provides new insights into the international level of civil war affects local conflict dynamics. The second part of the Special Issue is focused on the dynamics occurring at the group and the individual level. The diverse range of contributions to this Special Issue not only illustrate the scientific potential of the individual approaches to micro dynamics of armed conflict, but also the more general contributions that this kind of approach can offer to peace and conflict studies.
Examination and implications of experimental research on investor perceptions
Authors: Martin Rachel
Published: November 2019

This paper synthesizes existing experimental research in the area of investor perceptions and offers directions for future research. Investor-related experimental research has grown substantially, especially in the last decade, as it has made valuable contributions in establishing causal links, examining underlying process measures, and examining areas with little available data. Within this review, I examine 121 papers and identify three broad categories that affect investor perceptions: information format, investor features, and disclosure credibility. Information format describes how investors are influenced by information salience, information labeling, reporting and accounting complexity, financial statement recognition, explanatory disclosures, and proposed disclosure changes. Investor features describes investors’ use of heuristics, investor preferences, and the effect of investor experience. Disclosure credibility is influenced by external and internal assurance, management credibility, disclosure characteristics, and management incentives. Using this framework, I summarize the existing research and identify areas that would benefit from additional research.
The Identification and Stereochemistry Analysis of a Novel Mutation P.(D367Tfs*61) in the Cyp1B1 Gene
Authors: Salehi Chaleshtori Ahmad Reza , Garshasbi Masoud , Salehi Ali , Noruzinia Mehrdad
Published: November 2019

Purpose:

To investigate the presence of a probable genetic defect(s) that may cause primary congenital glaucoma (PCG) in a seven-year-old female patient.

Methods:

A seven-year-old female patient and her family received genetic counseling and underwent full clinical examinations by an expert ophthalmologist. The patient's genomic DNA was subjected to the targeted gene capture and next-generation sequencing (NGS) along with Sanger sequencing method. The 3D structure prediction and stereochemistry analysis were performed for both mutant and wild-type forms of the CYP1B1 protein.

Results:

The clinical examinations indicated that the diagnosis of PCG was correctly made. We identified a novel homozygous deletion in which a “C” nucleotide was deleted from the final exon of the Cytochrome P450 Family 1 Subfamily B Member 1 (CYP1B1) gene. The 3D molecular modeling of the CYP1B1 protein predicted significant structural changes could occur in this protein as a result of the mutation mentioned earlier. The stereochemistry analysis revealed mutant features of the protein, as well as significant misfolding and possible malfunctions in the mutant form of the CYP1B1 protein.

Conclusions:

This mutation might cause a frameshift in the translation process, leading to the malfunction of the CYP1B1 protein and development of glaucoma. This newly-identified mutation could be regarded as potential deletion mutation in genetic counseling and molecular examination for the detection of PCG disease in Iran.
Hormonal Treatment Effect on Sexual Distress in Transgender Persons: 2-Year Follow-Up Data
Authors: Ristori Jiska , Cocchetti Carlotta , Castellini Giovanni , Pierdominici Marina , Cipriani Agnese , Testi Diletta , Gavazzi Gioele , Mazzoli Francesca , Mosconi Maddalena , Meriggiola Maria Cristina , Cassioli Emanuele , Vignozzi Linda , Ricca Valdo , Maggi Mario , Fisher Alessandra D.
Published: November 2019

Introduction

As far as we know, no studies to date have investigated the psychobiological correlates of sexual distress (SD) nor the impact of hormonal treatment (HT) on SD in transgender persons.

Aim

To evaluate the psychobiological correlates of SD and assess the effects of HT on SD in transgender persons without gender-affirming surgery.

Methods

A consecutive series of 301 transgender persons (160 transwomen and 141 transmen) was considered for the cross-sectional study, and a subset of 72 subjects was studied in a 2-year follow-up. A physical examination was performed. Blood samples were drawn for determination of cortisol levels. Subjects completed psychometric measures. During 2 years of HT, the evaluation of SD was prospectively repeated.

Main Outcome Measure

Psychobiological correlates of SD in transgender population. Changes in SD during gender affirming hormonal treatment.

Clinical Implications

Knowing how hormonal treatment influence SD will help care providers when counseling transgender people.

Strengths & Limitations

To the authors’ knowledge, this is the first study prospectively evaluating the impact of gender affirming hormonal treatment on sexual distress in transgender individuals. The main limitations are represented by the small size of the sample and the use of questionnaires validated only in the cisgender population.

Results

SD showed a positive correlation with body uneasiness (P < .0001) and with dissatisfaction toward gender-related body parts or shapes (all P < .05). In addition, SD correlated positively with general psychopathology (P < .0001), alexithymia, social anxiety, and humiliation scales (all P < .05). In transmen, SD was positively associated with autism levels (P < .005), as well as with cortisol levels (P < .02). A significant correlation between SD and perceived discrimination was observed in transwomen (P < .05). In transwomen, SD was positively associated with hair density and negatively with breast growth (both P < .05). Finally, in transmen, a negative correlation was found between SD and hair density (P < .05). When the impact of HT on SD was evaluated, a significant reduction of SD was observed across time in both transwomen and transmen (P = .001 and P = .01, respectively).

Conclusions

The present results support the efficacy of HT in reducing SD in transgender persons.
Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update
Authors: Dow Jennifer , Giesbrecht Gordon G. , Danzl Daniel F. , Brugger Hermann , Sagalyn Emily B. , Walpoth Beat , Auerbach Paul S. , McIntosh Scott E. , Némethy Mária , McDevitt Marion , Schoene Robert B. , Rodway George W. , Hackett Peter H. , Zafren Ken , Bennett Brad L. , Grissom Colin K.
Published: November 2019

To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.
Efficient simulation of Lévy-driven point processes
Authors: Qu Yan , Dassios Angelos , Zhao Hongbiao
Published: November 2019

In this paper, we introduce a new large family of Lévy-driven point processes with (and without) contagion, by generalising the classical self-exciting Hawkes process and doubly stochastic Poisson processes with non-Gaussian Lévy-driven Ornstein–Uhlenbeck-type intensities. The resulting framework may possess many desirable features such as skewness, leptokurtosis, mean-reverting dynamics, and more importantly, the ‘contagion’ or feedback effects, which could be very useful for modelling event arrivals in finance, economics, insurance, and many other fields. We characterise the distributional properties of this new class of point processes and develop an efficient sampling method for generating sample paths exactly. Our simulation scheme is mainly based on the distributional decomposition of the point process and its intensity process. Extensive numerical implementations and tests are reported to demonstrate the accuracy and effectiveness of our scheme. Moreover, we use portfolio risk management as an example to show the applicability and flexibility of our algorithms.
Exact sampling for some multi-dimensional queueing models with renewal input
Authors: Blanchet Jose , Pei Yanan , Sigman Karl
Published: November 2019

Using a result of Blanchet and Wallwater (2015) for exactly simulating the maximum of a negative drift random walk queue endowed with independent and identically distributed (i.i.d.) increments, we extend it to a multi-dimensional setting and then we give a new algorithm for simulating exactly the stationary distribution of a first-in–first-out (FIFO) multi-server queue in which the arrival process is a general renewal process and the service times are i.i.d.: the FIFO GI/GI/c queue with
$ 2 \leq c \lt \infty$
. Our method utilizes dominated coupling from the past (DCFP) as well as the random assignment (RA) discipline, and complements the earlier work in which Poisson arrivals were assumed, such as the recent work of Connor and Kendall (2015). We also consider the models in continuous time, and show that with mild further assumptions, the exact simulation of those stationary distributions can also be achieved. We also give, using our FIFO algorithm, a new exact simulation algorithm for the stationary distribution of the infinite server case, the GI/GI/
$\infty$
model. Finally, we even show how to handle fork–join queues, in which each arriving customer brings c jobs, one for each server.
Rosuvastatin reduced brain parasite burden in a chronic toxoplasmosis in vivo model and influenced the neuropathological pattern of ME-49 strain
Authors: Nishi L. , Santana P. L. , Evangelista F. F. , Beletini L. F. , Souza A. H. , Mantelo F. M. , Souza-Kaneshima A. M. , Costa I. N. , Falavigna-Guilherme A. L.
Published: November 2019

This study evaluated the effects of rosuvastatin in vivo on toxoplasmosis chronic infection. Thirty-five Swiss mice were orally infected (ME-49 strain). After 50 days, the mice were separated into five groups: GI – non-infected, GII – infected, GIII – infected and treated with pyrimethamine and sulfadiazine (12.5 + 50 mg kg−1 body weight day−1), GIV and GV – infected and treated with rosuvastatin 10 and 40 mg kg−1 body weight day−1, respectively. After 21 days, we collected blood, liver, lungs, femoral biceps and brain were removed for Toxoplasma gondii DNA quantification by qPCR and histopathological analysis. GIV and GV did not present premature death or clinical changes, and the hepatic enzyme levels were lower compared to GI. Toxoplasma gondii DNA was detected mainly in brain and muscle, but the parasite load was significantly lower in GV compared to GII brains (P < 0.05). Histopathological changes were observed in brains, with T. gondii cysts as well as an inflammatory condition, including necrosis areas in GII and GIII. These data confirm active infection with tissue injury. This inflammatory condition was attenuated in the groups treated with rosuvastatin, especially R40 (GV). Our findings demonstrated the in vivo action of rosuvastatin in reducing cerebral parasitic load and indicate that this drug may interfere in chronic toxoplasmosis.
Moments of the Dedekind zeta function and other non-primitiveL-functions
Authors: HEAP WINSTON
Published: November 2019

We give a conjecture for the moments of the Dedekind zeta function of a Galois extension. This is achieved through the hybrid product method of Gonek, Hughes and Keating. The moments of the product over primes are evaluated using a theorem of Montgomery and Vaughan, whilst the moments of the product over zeros are conjectured using a heuristic method involving random matrix theory. The asymptotic formula of the latter is then proved for quadratic extensions in the lowest order case. We are also able to reproduce our moments conjecture in the case of quadratic extensions by using a modified version of the moments recipe of Conrey et al. Generalising our methods, we then provide a conjecture for moments of non-primitiveL-functions, which is supported by some calculations based on Selberg’s conjectures.
Associations between family factors, childhood adversity, negative life events and child anxiety disorders: an exploratory study of diagnostic specificity
Authors: Draisey Jenny , Halldorsson Brynjar , Cooper Peter , Creswell Cathy
Published: November 2019

Background:

Chronic childhood adversity, negative life events, and anxiogenic parenting behaviours have all been implicated in the development and maintenance of childhood anxiety disorders. However, few studies have addressed whether these factors are associated with particular types of childhood anxiety disorders.

Aims:

The aims of this study were to investigate whether specific associations were obtained between specific types of childhood anxiety disorder – namely, social anxiety disorder (SOC), separation anxiety disorder (SEP) and generalized anxiety disorder (GAD) – and the nature of particular forms of psycho-social risk – namely, chronic childhood adversity, negative life events, and particular forms of parenting behaviours.

Method:

Two-hundred and ten children (aged 7–12 years) who met diagnostic criteria for SOC, SEP or GAD and their primary caregivers completed questionnaire measures on chronic childhood adversity and negative life events. In addition, dyads participated in two laboratory-based assessments of parent–child interactions.

Results:

We found little evidence for disorder specificity for chronic childhood adversity and negative life events, except in the case of separation anxiety disorder. Anxious children with separation anxiety were more likely than children with other forms of anxiety disorders to live with a single parent, experience more frequent parent arguments, and more negative life events. No group differences in observed parenting behaviours were found.

Conclusions:

Childhood SEP may be particularly associated with family challenges which may need specific consideration to optimize prevention and/or treatment. Beyond this, there is limited evidence of specific associations between family and environmental factors and specific types of childhood anxiety disorders.
Idea Formulation for Spoken Language Production: The Interface of Cognition and Language
Authors: Barker Megan S. , Nelson Nicole L. , Robinson Gail A.
Published: November 2019

Background:

Language and communication are fundamental to the human experience, and, traditionally, spoken language is studied as an isolated skill. However, beforepropositional language(i.e., spontaneous, voluntary, novel speech) can be produced, propositional content or ‘ideas’ must be formulated.

Objective:

This review highlights the role of broader cognitive processes, particularly ‘executive attention’, in the formulation of propositional content (i.e., ‘ideas’) for propositional language production.

Conclusions:

Several key lines of evidence converge to suggest that the formulation of ideas for propositional language production draws on executive attentional processes. Larger-scale clinical research has demonstrated a link between attentional processes and language, while detailed case studies of neurological patients have elucidated specific idea formulation mechanisms relating to the generation, selection and sequencing of ideas for expression. Furthermore, executive attentional processes have been implicated in the generation of ideas for propositional language production. Finally, neuroimaging studies suggest that a widely distributed network of brain regions, including parts of the prefrontal and parietal cortices, supports propositional language production.

Implications:

Theoretically driven experimental research studies investigating mechanisms involved in the formulation of ideas are lacking. We suggest that novel experimental approaches are needed to define the contribution of executive attentional processes to idea formulation, from which comprehensive models of spoken language production can be developed. Clinically, propositional language impairments should be considered in the context of broader executive attentional deficits.
The Other Side of the Bell Curve: Multivariate Base Rates of High Scores on the Delis-Kaplan Executive Function System
Authors: Karr Justin E. , Garcia-Barrera Mauricio A. , Holdnack James A. , Iverson Grant L.
Published: November 2019

Objective:

Previous researchers have examined the frequency at which healthy participants obtain one or more low scores on neuropsychological test batteries, proposing five psychometric principles of multivariate base rates: (a) low scores are common, with their frequency contingent on (b) the low score cutoff used, (c) the number of tests administered/interpreted, and (d) the demographic characteristics and (e) intelligence of participants. The current study explored whether these principles applied to high scores as well, using the Delis-Kaplan Executive Function System (D-KEFS).

Method:

Multivariate base rates of high scores (≥75th, ≥84th, ≥91st, ≥95th, and ≥98th percentiles) were derived for a three-test, four-test, and full D-KEFS battery, using the adult portion of the normative sample (aged 16–89 years; N = 1050) stratified by education and intelligence. The full D-KEFS battery provides 16 total achievement scores (primary indicators of executive function).

Results:

High scores occurred commonly for all batteries. For the three-test battery, 24.1% and 12.4% had 1 or more scores ≥95th percentile and ≥98th percentile, respectively. High scores occurred more often for longer batteries: 61.6%, 72.9%, and 87.8% obtained 1 or more scores ≥84th percentile for the three-test, four-test, and full batteries, respectively. The frequency of high scores increased with more education and higher intelligence.

Conclusions:

The principles of multivariate base rates also applied to high D-KEFS scores: high scores were common and contingent on the cutoff used, number of tests administered/interpreted, and education/intelligence of examinees. Base rates of high scores may help clinicians identify true cognitive strengths and detect cognitive deficits in high functioning people.
Past Life Experiences and Neurological Recovery: The Role of Cognitive Reserve in the Rehabilitation of Severe Post-Anoxic Encephalopathy and Traumatic Brain Injury
Authors: Menardi Arianna , Bertagnoni Giannettore , Sartori Giuseppe , Pastore Massimiliano , Mondini Sara
Published: November 2019

Objective:

Patients with an equivalent clinical background may show unexpected interindividual differences in their outcome. The cognitive reserve (CR) model has been proposed to account for such discrepancies, but its role after acquired severe injuries is still being debated. We hypothesize that inappropriate investigative methods might have been used when dealing with severe patients, which have very likely reduced the possibility of observing meaningful influences in recovery from severe traumas.

Methods:

To overcome this issue, the potential neuroprotective role of CR was investigated, considering a wider spectrum of clinical symptoms ranging from low-level brain stem functions necessary for life to more complex motor and cognitive skills. In the present study, data from 50 severe patients, 20 suffering from post-anoxic encephalopathy (PAE) and 30 with traumatic brain injury (TBI), were collected and retrospectively analyzed.

Results:

We found that CR, diagnosis, time of hospitalization, and their interaction had an effect on the clinical indexes. When the predictive power of CR was investigated by means of two machine learning classifier algorithms, CR, together with age, emerged as the strongest factor in discriminating between patients who reached or did not reach successful recovery.

Conclusions:

Overall, the present study highlights a possible role of CR in shaping the recovery of severe patients suffering from either PAE or TBI. The practical implications underlying the need to routinely considered CR in the clinical practice are discussed.
Investigations of the sensitivity of ornamental, fruit, and nut plant species to driftable rates of 2,4-D and dicamba
Authors: Dintelmann Brian R. , Warmund Michele R. , Bish Mandy D. , Bradley Kevin W.
Published: November 2019

An experiment was conducted in 2017 and 2018 to determine the sensitivity of driftable rates of 2,4-D and dicamba with or without glyphosate on common ornamental, fruit, and nut species. Three driftable rates corresponding to ½, 1/20th, and 1/200th of the manufacturer’s labeled rate (1 × rate) of 2,4-D (1.09 kg ae ha−1), 2,4-D plus glyphosate (1.09 kg ae ha−1 plus 1.10 kg ae ha−1), dicamba (0.56 kg ae ha−1), and dicamba plus glyphosate (0.56 kg ae ha−1 plus 1.10 kg ae ha−1) were applied to apple, crabapple, dogwood, American elderberry, American elm, grapevine, hydrangea, red maple, pin oak, peach, pecan, eastern redbud, rose, red raspberry, strawberry, sweetgum, nannyberry viburnum, and black walnut plants. Visible estimates of injury were recorded 28 and 56 days after treatment (DAT). Plant measurements included leaf malformation, tree trunk growth, and shoot length. Across all species, the ½ × rate of 2,4-D plus glyphosate resulted in 61% injury 28 DAT, whereas the ½ × rate of dicamba plus glyphosate resulted in 51% injury. Across plant species and herbicides, ½ ×, 1/20 ×, and 1/200 × rates caused injury ranging from 3% to 100%, 0% to 66%, and 0% to 19%, respectively. Hydrangea was the least sensitive species; grapevine was most sensitive. Changes in plant measurements were dependent on the species and herbicide applied. Treatments at the ½ × or 1/20 × rate resulted in shoot length, leaf malformation, and trunk tree diameter differences for 11, 10, and 7 species, respectively, compared with nontreated plants. Collectively, the measurements and visual injury assessments indicated apple, red maple, peach, and pin oak were more sensitive to treatments containing dicamba, whereas black walnut, grapevine, and American elm were more sensitive to 2,4-D. Although the 1/200 × rates of 2,4-D and dicamba did not result in changes to plant measurements, obvious injury symptoms were observed, which could render these plants unsalable.
The Contribution of Surface and Submesoscale Processes to Turbulence in the Open Ocean Surface Boundary Layer
Authors: Buckingham Christian E. , Lucas Natasha S. , Belcher Stephen E. , Rippeth Tom P. , Grant Alan L. M. , Le Sommer Julien , Ajayi Adekunle Opeoluwa , Naveira Garabato Alberto C.
Published: November 2019

The ocean surface boundary layer is a critical interface across which momentum, heat, and trace gases are exchanged between the oceans and atmosphere. Surface processes (winds, waves, and buoyancy forcing) are known to contribute significantly to fluxes within this layer. Recently, studies have suggested that submesoscale processes, which occur at small scales (0.1–10 km, hours to days) and therefore are not yet represented in most ocean models, may play critical roles in these turbulent exchanges. While observational support for such phenomena has been demonstrated in the vicinity of strong current systems and littoral regions, relatively few observations exist in the open‐ocean environment to warrant representation in Earth system models. We use novel observations and simulations to quantify the contributions of surface and submesoscale processes to turbulent kinetic energy (TKE) dissipation in the open‐ocean surface boundary layer. Our observations are derived from moorings in the North Atlantic, December 2012 to April 2013, and are complemented by atmospheric reanalysis. We develop a conceptual framework for dissipation rates due to surface and submesoscale processes. Using this framework and comparing with observed dissipation rates, we find that surface processes dominate TKE dissipation. A parameterization for symmetric instability is consistent with this result. We next employ simulations from an ocean front‐resolving model to reestablish that dissipation due to surface processes exceeds that of submesoscale processes by 1–2 orders of magnitude. Together, these results suggest submesoscale processes do not dramatically modify vertical TKE budgets, though such dynamics may be climatically important owing to their ability to remove energy from the ocean.
Selection footprints reflect genomic changes associated with breeding efforts in 56 cucumber inbred lines
Authors: Liu Bin , Guan Dailu , Zhai Xuling , Yang Sen , Xue Shudan , Chen Shuying , Huang Jing , Ren Huazhong , Liu Xingwang
Published: November 2019

Cucumber selective breeding over recent decades has dramatically increased productivity and quality, but the genomic characterizations and changes associated with this breeding history remain unclear. Here, we analyzed the genome resequencing data of 56 artificially selected cucumber inbred lines that exhibit various phenotypes to detect trait-associated sequence variations that reflect breeding improvement. We found that the 56 cucumber lines could be assigned to group 1 and group 2, and the two groups formed a distinctive genetic structure due to the breeding history involving hybridization and selection. Differentially selected regions were identified between group 1 and group 2, with implications for genomic-selection breeding signatures. These regions included known quantitative trait loci or genes that were reported to be associated with agronomic traits. Our results advance knowledge of cucumber genomics, and the 56 selected inbred lines could be good germplasm resources for breeding.
General technoeconomic analysis for electrochemical coproduction coupling carbon dioxide reduction with organic oxidation
Authors: Na Jonggeol , Seo Bora , Kim Jeongnam , Lee Chan Woo , Lee Hyunjoo , Hwang Yun Jeong , Min Byoung Koun , Lee Dong Ki , Oh Hyung-Suk , Lee Ung
Published: November 2019

Electrochemical processes coupling carbon dioxide reduction reactions with organic oxidation reactions are promising techniques for producing clean chemicals and utilizing renewable energy. However, assessments of the economics of the coupling technology remain questionable due to diverse product combinations and significant process design variability. Here, we report a technoeconomic analysis of electrochemical carbon dioxide reduction reaction–organic oxidation reaction coproduction via conceptual process design and thereby propose potential economic combinations. We first develop a fully automated process synthesis framework to guide process simulations, which are then employed to predict the levelized costs of chemicals. We then identify the global sensitivity of current density, Faraday efficiency, and overpotential across 295 electrochemical coproduction processes to both understand and predict the levelized costs of chemicals at various technology levels. The analysis highlights the promise that coupling the carbon dioxide reduction reaction with the value-added organic oxidation reaction can secure significant economic feasibility.
Atomically dispersed nickel as coke-resistant active sites for methane dry reforming
Authors: Akri Mohcin , Zhao Shu , Li Xiaoyu , Zang Ketao , Lee Adam F. , Isaacs Mark A. , Xi Wei , Gangarajula Yuvaraj , Luo Jun , Ren Yujing , Cui Yi-Tao , Li Lei , Su Yang , Pan Xiaoli , Wen Wu , Pan Yang , Wilson Karen , Li Lin , Qiao Botao , Ishii Hirofumi , Liao Yen-Fa , Wang Aiqin , Wang Xiaodong , Zhang Tao
Published: November 2019

Dry reforming of methane (DRM) is an attractive route to utilize CO2 as a chemical feedstock with which to convert CH4 into valuable syngas and simultaneously mitigate both greenhouse gases. Ni-based DRM catalysts are promising due to their high activity and low cost, but suffer from poor stability due to coke formation which has hindered their commercialization. Herein, we report that atomically dispersed Ni single atoms, stabilized by interaction with Ce-doped hydroxyapatite, are highly active and coke-resistant catalytic sites for DRM. Experimental and computational studies reveal that isolated Ni atoms are intrinsically coke-resistant due to their unique ability to only activate the first C-H bond in CH4, thus avoiding methane deep decomposition into carbon. This discovery offers new opportunities to develop large-scale DRM processes using earth abundant catalysts.
Climate shapes mammal community trophic structures and humans simplify them
Authors: Mendoza Manuel , Araújo Miguel B.
Published: November 2019

Nature’s complexity is intriguing, but the circumstances determining whether or how order emerges from such complexity remains a matter of extensive research. Using the geographical distributions and food preferences of all terrestrial mammal species with masses >3 kg, we show that large mammals group into feeding guilds (species exploiting similar resources) and that these guilds form trophic structures that vary across biomes globally. We identify five trophic structures closely matching climate variability and named them boreal, temperate, semiarid, seasonal tropical and humid tropical owing to their relative overlap with the distribution of biomes. We also find that human activities simplify trophic structures, generally transitioning them to species-poorer states. Detected transitions include boreal and temperate structures becoming depauperate or seasonal- and humid-tropical becoming semiarid. Whether the observed generalities among trophic structures of large mammals are indicative of patterns across whole food webs is matter for further investigation. The results help refine projections of the effects of environmental change on the trophic structure of large mammals.
The dicarbon bonding puzzle viewed with photoelectron imaging
Authors: Laws B. A. , Gibson S. T. , Lewis B. R. , Field R. W.
Published: November 2019

Bonding in the ground state of C$${}_{2}$$

2

is still a matter of controversy, as reasonable arguments may be made for a dicarbon bond order of $$2$$
2
, $$3$$
3
, or $$4$$
4
. Here we report on photoelectron spectra of the C$${}_{2}^{-}$$

2

−

anion, measured at a range of wavelengths using a high-resolution photoelectron imaging spectrometer, which reveal both the ground $${X}^{1}{\Sigma}_{\mathrm{g}}^{+}$$

X

1

Σ

g

+

and first-excited $${a}^{3}{\Pi}_{{\mathrm{u}}}$$

a

3

Π

u

electronic states. These measurements yield electron angular anisotropies that identify the character of two orbitals: the diffuse detachment orbital of the anion and the highest occupied molecular orbital of the neutral. This work indicates that electron detachment occurs from predominantly $$s$$
s
-like ($$3{\sigma}_{\mathrm{g}}$$
3

σ

g

) and $$p$$
p
-like ($$1{\pi }_{{\mathrm{u}}}$$
1

π

u

) orbitals, respectively, which is inconsistent with the predictions required for the high bond-order models of strongly $$sp$$
s
p
-mixed orbitals. This result suggests that the dominant contribution to the dicarbon bonding involves a double-bonded configuration, with 2$$\pi$$
π
bonds and no accompanying $$\sigma$$
σ
bond.
Superb water splitting activity of the electrocatalyst Fe3Co(PO4)4 designed with computation aid
Authors: Sultan Siraj , Ha Miran , Kim Dong Yeon , Tiwari Jitendra N. , Myung Chang Woo , Meena Abhishek , Shin Tae Joo , Chae Keun Hwa , Kim Kwang S.
Published: November 2019

For efficient water splitting, it is essential to develop inexpensive and super-efficient electrocatalysts for the oxygen evolution reaction (OER). Herein, we report a phosphate-based electrocatalyst [Fe3Co(PO4)4@reduced-graphene-oxide(rGO)] showing outstanding OER performance (much higher than state-of-the-art Ir/C catalysts), the design of which was aided by first-principles calculations. This electrocatalyst displays low overpotential (237 mV at high current density 100 mA cm−2 in 1 M KOH), high turnover frequency (TOF: 0.54 s−1), high Faradaic efficiency (98%), and long-term durability. Its remarkable performance is ascribed to the optimal free energy for OER at Fe sites and efficient mass/charge transfer. When a Fe3Co(PO4)4@rGO anodic electrode is integrated with a Pt/C cathodic electrode, the electrolyzer requires only 1.45 V to achieve 10 mA cm−2 for whole water splitting in 1 M KOH (1.39 V in 6 M KOH), which is much smaller than commercial Ir-C//Pt-C electrocatalysts. This cost-effective powerful oxygen production material with carbon-supporting substrates offers great promise for water splitting.
Spectroelectrochemical study of water oxidation on nickel and iron oxyhydroxide electrocatalysts
Authors: Francàs Laia , Corby Sacha , Selim Shababa , Lee Dongho , Mesa Camilo A. , Godin Robert , Pastor Ernest , Stephens Ifan E. L. , Choi Kyoung-Shin , Durrant James R.
Published: November 2019

Ni/Fe oxyhydroxides are the best performing Earth-abundant electrocatalysts for water oxidation. However, the origin of their remarkable performance is not well understood. Herein, we employ spectroelectrochemical techniques to analyse the kinetics of water oxidation on a series of Ni/Fe oxyhydroxide films: FeOOH, FeOOHNiOOH, and Ni(Fe)OOH (5% Fe). The concentrations and reaction rates of the oxidised states accumulated during catalysis are determined. Ni(Fe)OOH is found to exhibit the fastest reaction kinetics but accumulates fewer states, resulting in a similar performance to FeOOHNiOOH. The later catalytic onset in FeOOH is attributed to an anodic shift in the accumulation of oxidised states. Rate law analyses reveal that the rate limiting step for each catalyst involves the accumulation of four oxidised states, Ni-centred for Ni(Fe)OOH but Fe-centred for FeOOH and FeOOHNiOOH. We conclude by highlighting the importance of equilibria between these accumulated species and reactive intermediates in determining the activity of these materials.
A Bayesian mixture model for the analysis of allelic expression in single cells
Authors: Choi Kwangbom , Raghupathy Narayanan , Churchill Gary A.
Published: November 2019

Allele-specific expression (ASE) at single-cell resolution is a critical tool for understanding the stochastic and dynamic features of gene expression. However, low read coverage and high biological variability present challenges for analyzing ASE. We demonstrate that discarding multi-mapping reads leads to higher variability in estimates of allelic proportions, an increased frequency of sampling zeros, and can lead to spurious findings of dynamic and monoallelic gene expression. Here, we report a method for ASE analysis from single-cell RNA-Seq data that accurately classifies allelic expression states and improves estimation of allelic proportions by pooling information across cells. We further demonstrate that combining information across cells using a hierarchical mixture model reduces sampling variability without sacrificing cell-to-cell heterogeneity. We applied our approach to re-evaluate the statistical independence of allelic bursting and track changes in the allele-specific expression patterns of cells sampled over a developmental time course.
Stroke among cancer patients
Authors: Zaorsky Nicholas G. , Zhang Ying , Tchelebi Leila T. , Mackley Heath B. , Chinchilli Vernon M. , Zacharia Brad E.
Published: November 2019

We identify cancer patients at highest risk of fatal stroke. This is a population-based study using nationally representative data from the Surveillance, Epidemiology, and End Results program, 1992-2015. Among 7,529,481 cancer patients, 80,513 died of fatal stroke (with 262,461 person-years at risk); the rate of fatal stroke was 21.64 per 100,000-person years, and the standardized mortality ratio (SMR) of fatal stroke was 2.17 (95% CI, 2.15, 2.19). Patients with cancer of the prostate, breast, and colorectum contribute to the plurality of cancer patients dying of fatal stroke. Brain and gastrointestinal cancer patients had the highest SMRs (>2-5) through the follow up period. Among those diagnosed at <40 years of age, the plurality of strokes occurs in patients treated for brain tumors and lymphomas; if >40, from cancers of the prostate, breast, and colorectum. For almost all cancers survivors, the risk of stroke increases with time.
Modular actin nano-architecture enables podosome protrusion and mechanosensing
Authors: van den Dries Koen , Nahidiazar Leila , Slotman Johan A. , Meddens Marjolein B. M. , Pandzic Elvis , Joosten Ben , Ansems Marleen , Schouwstra Joost , Meijer Anke , Steen Raymond , Wijers Mietske , Fransen Jack , Houtsmuller Adriaan B. , Wiseman Paul W. , Jalink Kees , Cambi Alessandra
Published: November 2019

Basement membrane transmigration during embryonal development, tissue homeostasis and tumor invasion relies on invadosomes, a collective term for invadopodia and podosomes. An adequate structural framework for this process is still missing. Here, we reveal the modular actin nano-architecture that enables podosome protrusion and mechanosensing. The podosome protrusive core contains a central branched actin module encased by a linear actin module, each harboring specific actin interactors and actin isoforms. From the core, two actin modules radiate: ventral filaments bound by vinculin and connected to the plasma membrane and dorsal interpodosomal filaments crosslinked by myosin IIA. On stiff substrates, the actin modules mediate long-range substrate exploration, associated with degradative behavior. On compliant substrates, the vinculin-bound ventral actin filaments shorten, resulting in short-range connectivity and a focally protrusive, non-degradative state. Our findings redefine podosome nanoscale architecture and reveal a paradigm for how actin modularity drives invadosome mechanosensing in cells that breach tissue boundaries.
A general method for the creation of dilational surfaces
Authors: Broeren Freek G. J. , van de Sande Werner W. P. J. , van der Wijk Volkert , Herder Just L.
Published: November 2019

Dilational structures can change in size without changing their shape. Current dilational designs are only suitable for specific shapes or curvatures and often require parts of the structure to move perpendicular to the dilational surface, thereby occupying part of the enclosed volume. Here, we present a general method for creating dilational structures from arbitrary surfaces (2-manifolds with or without boundary), where all motions are tangent to the described surface. The method consists of triangulating the target curved surface and replacing each of the triangular faces by pantograph mechanisms according to a tiling algorithm that avoids collisions between neighboring pantographs. Following this algorithm, any surface can be made to mechanically dilate and could, theoretically, scale from the fully expanded configuration down to a single point. We illustrate the method with three examples of increasing complexity and varying Gaussian curvature.
A therapeutic antibody targeting osteoprotegerin attenuates severe experimental pulmonary arterial hypertension
Authors: Arnold Nadine D. , Pickworth Josephine A. , West Laura E. , Dawson Sarah , Carvalho Joana A. , Casbolt Helen , Braithwaite Adam T. , Iremonger James , Renshall Lewis , Germaschewski Volker , McCourt Matthew , Bland-Ward Philip , Kowash Hager , Hameed Abdul G. , Rothman Alexander M. K. , Frid Maria G. , Roger Thompson A. A. , Evans Holly R. , Southwood Mark , Morrell Nicholas W. , Crossman David C. , Whyte Moira K. B. , Stenmark Kurt R. , Newman Christopher M. , Kiely David G. , Francis Sheila E. , Lawrie Allan
Published: November 2019

Pulmonary arterial hypertension (PAH) is a rare but fatal disease. Current treatments increase life expectancy but have limited impact on the progressive pulmonary vascular remodelling that drives PAH. Osteoprotegerin (OPG) is increased within serum and lesions of patients with idiopathic PAH and is a mitogen and migratory stimulus for pulmonary artery smooth muscle cells (PASMCs). Here, we report that the pro-proliferative and migratory phenotype in PASMCs stimulated with OPG is mediated via the Fas receptor and that treatment with a human antibody targeting OPG can attenuate pulmonary vascular remodelling associated with PAH in multiple rodent models of early and late treatment. We also demonstrate that the therapeutic efficacy of the anti-OPG antibody approach in the presence of standard of care vasodilator therapy is mediated by a reduction in pulmonary vascular remodelling. Targeting OPG with a therapeutic antibody is a potential treatment strategy in PAH.
Prolyl hydroxylase substrate adenylosuccinate lyase is an oncogenic driver in triple negative breast cancer
Authors: Zurlo Giada , Liu Xijuan , Takada Mamoru , Fan Cheng , Simon Jeremy M. , Ptacek Travis S. , Rodriguez Javier , von Kriegsheim Alex , Liu Juan , Locasale Jason W. , Robinson Adam , Zhang Jing , Holler Jessica M. , Kim Baek , Zikánová Marie , Bierau Jörgen , Xie Ling , Chen Xian , Li Mingjie , Perou Charles M. , Zhang Qing
Published: November 2019

Protein hydroxylation affects protein stability, activity, and interactome, therefore contributing to various diseases including cancers. However, the transiency of the hydroxylation reaction hinders the identification of hydroxylase substrates. By developing an enzyme-substrate trapping strategy coupled with TAP-TAG or orthogonal GST- purification followed by mass spectrometry, we identify adenylosuccinate lyase (ADSL) as an EglN2 hydroxylase substrate in triple negative breast cancer (TNBC). ADSL expression is higher in TNBC than other breast cancer subtypes or normal breast tissues. ADSL knockout impairs TNBC cell proliferation and invasiveness in vitro and in vivo. An integrated transcriptomics and metabolomics analysis reveals that ADSL activates the oncogenic cMYC pathway by regulating cMYC protein level via a mechanism requiring ADSL proline 24 hydroxylation. Hydroxylation-proficient ADSL, by affecting adenosine levels, represses the expression of the long non-coding RNA MIR22HG, thus upregulating cMYC protein level. Our findings highlight the role of ADSL hydroxylation in controlling cMYC and TNBC tumorigenesis.
All WSe2 1T1R resistive RAM cell for future monolithic 3D embedded memory integration
Authors: Sivan Maheswari , Li Yida , Veluri Hasita , Zhao Yunshan , Tang Baoshan , Wang Xinghua , Zamburg Evgeny , Leong Jin Feng , Niu Jessie Xuhua , Chand Umesh , Thean Aaron Voon-Yew
Published: November 2019

3D monolithic integration of logic and memory has been the most sought after solution to surpass the Von Neumann bottleneck, for which a low-temperature processed material system becomes inevitable. Two-dimensional materials, with their excellent electrical properties and low thermal budget are potential candidates. Here, we demonstrate a low-temperature hybrid co-integration of one-transistor-one-resistor memory cell, comprising a surface functionalized 2D WSe2p-FET, with a solution-processed WSe2 Resistive Random Access Memory. The employed plasma oxidation technique results in a low Schottky barrier height of 25 meV with a mobility of 230 cm2 V−1 s−1, leading to a 100x performance enhanced WSe2p-FET, while the defective WSe2 Resistive Random Access Memory exhibits a switching energy of 2.6 pJ per bit. Furthermore, guided by our device-circuit modelling, we propose vertically stacked channel FETs for high-density sub-0.01 μm2 memory cells, offering a new beyond-Si solution to enable 3-D embedded memories for future computing systems.
Oxygen-catalysed sequential singlet fission
Authors: Wollscheid Nikolaus , Pérez Lustres J. Luis , Kefer Oskar , Hahn Sebastian , Brosius Victor , Bunz Uwe H. F. , Motzkus Marcus , Buckup Tiago
Published: November 2019

Singlet fission is the photoinduced conversion of a singlet exciton into two triplet states of half-energy. This multiplication mechanism has been successfully applied to improve the efficiency of single-junction solar cells in the visible spectral range. Here we show that singlet fission may also occur via a sequential mechanism, where the two triplet states are generated consecutively by exploiting oxygen as a catalyst. This sequential formation of carriers is demonstrated for two acene-like molecules in solution. First, energy transfer from the excited acene to triplet oxygen yields one triplet acene and singlet oxygen. In the second stage, singlet oxygen combines with a ground-state acene to complete singlet fission. This yields a second triplet molecule. The sequential mechanism accounts for approximately 40% of the triplet quantum yield in the studied molecules; this process occurs in dilute solutions and under atmospheric conditions, where the single-step SF mechanism is inactive.
Cohesin cleavage by separase is enhanced by a substrate motif distinct from the cleavage site
Authors: Rosen Laura E. , Klebba Joseph E. , Asfaha Jonathan B. , Ghent Chloe M. , Campbell Melody G. , Cheng Yifan , Morgan David O.
Published: November 2019

Chromosome segregation begins when the cysteine protease, separase, cleaves the Scc1 subunit of cohesin at the metaphase-to-anaphase transition. Separase is inhibited prior to metaphase by the tightly bound securin protein, which contains a pseudosubstrate motif that blocks the separase active site. To investigate separase substrate specificity and regulation, here we develop a system for producing recombinant, securin-free human separase. Using this enzyme, we identify an LPE motif on the Scc1 substrate that is distinct from the cleavage site and is required for rapid and specific substrate cleavage. Securin also contains a conserved LPE motif, and we provide evidence that this sequence blocks separase engagement of the Scc1 LPE motif. Our results suggest that rapid cohesin cleavage by separase requires a substrate docking interaction outside the active site. This interaction is blocked by securin, providing a second mechanism by which securin inhibits cohesin cleavage.
Rpd3L and Hda1 histone deacetylases facilitate repair of broken forks by promoting sister chromatid cohesion
Authors: Ortega Pedro , Gómez-González Belén , Aguilera Andrés
Published: November 2019

Genome stability involves accurate replication and DNA repair. Broken replication forks, such as those encountering a nick, lead to double strand breaks (DSBs), which are preferentially repaired by sister-chromatid recombination (SCR). To decipher the role of chromatin in eukaryotic DSB repair, here we analyze a collection of yeast chromatin-modifying mutants using a previously developed system for the molecular analysis of repair of replication-born DSBs by SCR based on a mini-HO site. We confirm the candidates through FLP-based systems based on a mutated version of the FLP flipase that causes nicks on either the leading or lagging DNA strands. We demonstrate that Rpd3L and Hda1 histone deacetylase (HDAC) complexes contribute to the repair of replication-born DSBs by facilitating cohesin loading, with no effect on other types of homology-dependent repair, thus preventing genome instability. We conclude that histone deacetylation favors general sister chromatid cohesion as a necessary step in SCR.