bluuebunny/crossref_metadata_2025 huggingface dataset:
Pontos (in)comuns nos processos de formação de professores de matemática identificados ao longo de quase duas décadas (2000-2017)
Authors: De Paula Marlubia Corrêa , Petró Caroline Da Silva , Sostisso Alessandra Fabian , De lima Reinaldo Feio
Published: September 2019

Neste artigo foram contabilizados artigos publicados em quatro revistas eletrônicas com Qualis A-1 e B-1. Nessas revistas procurou-se quais seriam as questões (in)comuns que têm norteado os processos de formação de professores. Trata-se, assim, de uma pesquisa qualitativa com abordagem fenomenológica, realizada por meio de busca documental e bibliográfica. O método de análise utilizado foi a meta-análise. Para esse fim, selecionou-se um total de 40 artigos, tendo sido localizados, entre estes, sete artigos de universidades da Espanha e um de Honduras. Dado o número de trabalhos selecionados, foi possível determinar o quanto as publicações de diferentes revistas apontavam, naquele momento, para diferentes ações formativas. Conclui-se que foram constatadas 30 características nos 40 artigos analisados. Alguns temas foram identificados simultaneamente em diferentes revistas, o qual referia-se ao modo como o professor se comunica em sala de aula. Políticas públicas voltadas às ações dos professores estiveram presentes numa ocorrência de dois artigos. O uso de tecnologias pelos professores em formação foi uma questão abordada em quatro dos 40 artigos selecionados. O tema apresentado numa maior frequência entre as publicações dessas revistas foi a preocupação em desenvolver conteúdos matemáticos. Essa questão foi manifestada em seis artigos (estudo sobre funções, geometria, números decimais e conjuntos numéricos na educação básica; estatística, limites e continuidades no ensino superior). Pode-se afirmar, também, que a característica da formação de professores, realizada no período referente à década de 60, onde havia uma preocupação conteudista, é ainda a maior presença, devido aos dados levantados neste artigo.
Um estudo da parábola: quadros, registros de representação semiótica e pontos de vista
Authors: Siqueira Carlos Alberto Fernandes de , Silva Maria José Ferreira da
Published: September 2019

Neste artigo faremos um estudo bibliográfico com a finalidade de fazer uma reflexão a respeito do estudo da parábola a partir das noções de Quadros, Pontos de Vista e de Registros de Representação Semiótica. Não temos a intenção de esgotar o assunto, pois estamos interessados apenas no que se refere ao ensino básico. Assim, articulamos no quadro da Geometria os pontos de vista do corte entre plano e cone, e de lugar geométrico utilizando o registro material, o registro figural e o registro algébrico. A partir desse estudo mudamos o ponto de vista para o quadro da Geometria Analítica representando a parábola no plano cartesiano, que a caracteriza agora como um registro gráfico e o articulamos com o obtido como representação algébrica no quadro anterior para desenvolver outras representações algébricas, as equações.
Review of PRGF Program Design - Overview
Authors:   International Monetary Fund
Published: September 2019

Part of the Fund’s periodic reviews of its policy advice to member countries, and responds to calls by Executive Directors for further staff analysis on improving the design of such programs. In the context of the recent discussions on the design of the broad range of Fund-supported programs, Directors also requested more in-depth analytical studies of disaggregated and homogenous groups, as well as a closer look at how progress towards external viability in low-income countries (LICs) can be improved. The review also seeks to address these requests.
Review of the IMF's Trade Restrictiveness Index
Authors:   International Monetary Fund
Published: September 2019

This paper examines the construction of the index and its use over the past seven years, identifies its limitations, examines several alternative measures of trade policy, and highlights some options for improving the Fund’s use of trade policy indicators.
Exchange Rates and Trade Balance Adjustment in Emerging Market Economies
Authors:   International Monetary Fund
Published: September 2019

The paper finds that simple econometric specifications yield surprising rich and complex dynamics -- relative prices respond to the nominal exchange rate and pass-through effects, import and export volumes respond to relative price changes, and the trade balance responds to changes in import and export values.
Revenue Mobilization in Developing Countries
Authors:   International Monetary Fund
Published: September 2019

The Fund has long played a lead role in supporting developing countries’ efforts to improve their revenue mobilization. This paper draws on that experience to review issues and good practice, and to assess prospects in this key area.
Federated States of Micronesia
Authors:   International Monetary Fund. Fiscal Affairs Dept.
Published: September 2019

This Climate Change Policy Assessment (CCPA) takes stock of the Federated States of
Micronesia (FSM)’s climate response plans, from the perspective of their macroeconomic and
fiscal implications. The CCPA is a joint initiative by the IMF and World Bank to assist small states to
understand and manage the expected economic impact of climate change, while safeguarding longrun
fiscal and external sustainability. It explores the possible impact of climate change and natural
disasters and the cost of FSM’s planned response. It suggests macroeconomically relevant reforms
that could strengthen the national strategy and identifies policy gaps and resource needs.
Experiências de (in)acessibilidade vivenciadas por pessoas com lesão medular
Authors: Bega Ruiz Aline Gabriela , Barreto Mayckel Da Silva , Paiano Marcelle , Pupulim Jussara Simone Lenzi , Decesaro Maria das Neves , Marcon Sonia Silva
Published: September 2019

Objetivo: apreender as experiências de (in)acessibilidade vivenciadas por pessoas com lesão medular. Método: pesquisa descritiva exploratória de abordagem qualitativa. Os dados foram coletados no período de janeiro a junho de 2016, junto a 23 pessoas com lesão medular, por meio de entrevista, e após, submetidos à análise de conteúdo, modalidade temática. Resultados: emergiram duas categorias, as quais mostram que embora em algumas situações as pessoas com lesão medular se sintam acolhidas, elas frequentemente vivenciam exclusão social e preconceito. Conclusão: pessoas com lesão medular enfrentam dificuldades para realizar atividades cotidianas com autonomia, insuficiência e/ou deficiência na acessibilidade e no apoio familiar/social. Contudo, a prática esportiva e a atuação familiar podem constituir incentivo efetivo a convivência social e igualitária.
From the Editors
Authors: Alejziak Wiesław , Szczechowicz Bartosz
Published: September 2019

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The first five years' clinical experience of the Australian National Liver Transplantation Unit
Authors: Sheil A G Ross , McCaughan Geoffrey W , Thompson John F , Stephen Michael S , Bookallil Michael J , Dorney Stuart F A
Published: September 2019

Objective

To report the first five years' clinical experience of the Australian National Liver Transplant Unit.

Patients

Three hundred and seventy patients were referred — 292 adults (79%) and 78 children (21%). The major causes of liver failure in the adults were chronic active hepatitis (25%), primary biliary cirrhosis (12%), primary sclerosing cholangitis (12%), alcoholic cirrhosis (9%) and malignancy (9%). Ten per cent of patients were referred in fulminant hepatic failure. In children, the major causes were biliary atresia (40%) and inborn errors in metabolism (27%).

Results

Two hundred and sixty‐three patients (71%) were accepted for transplantation. Of 158 (43%) accepted for early transplantation, 22 (14%) died before a donor became available. Four hundred and forty‐ three suitable organ donors were referred. One hundred and twenty‐six patients, including 32 children (25%), received 137 grafts. Three patients with renal failure due to hyperoxaluria type 1 received concurrent renal grafts. Ninety‐two patients survived (73%). For all recipients, one‐year survival was 75%. Two, three and four‐year survivals were 69%. One to four‐year survivals for adults with benign conditions were 77%, contrasting with results for those with hepatic malignancy (40% one‐year survival). Children weighing more than 8 kg had good outcomes whether they received whole grafts or reduced‐size grafts (83% one to five‐year survival in both cases). Infants weighing less than 8 kg who received reduced adult grafts did significantly worse (37% one to‐five year survival, P<0.05). Thirteen (87%) of 15 patients with fulminant hepatic failure who received grafts survived. Five of these patients were given ABO‐incompatible grafts and two subsequently required retransplantation. All three patients with concurrent renal and hepatic grafts survived. Rehabilitation of survivors was excellent with 95% of adults and 100% of children pursuing normal activities. Only three grafts (2%) failed with primary non‐function, all in infants because of graft infarction. Graft survival was significantly worse (P<0.01) in patients with a positive result to a direct cross match test against the donor.

Conclusions

The need for liver transplantation in Australia is approximately eight per million of population per year. More donor offers are required to prevent deaths of patients on the waiting list. Reduced‐size livers are successful for children and have alleviated considerably the critical shortage of paediatric donor livers. Successful treatment by liver transplantation can now be achieved in more than 80% of patients With non‐malignant liver disorders including those with fulminant hepatic failure not responding to conservative therapy.
Islamischer Feminismus im Iran
Authors: Khadivi Golrang
Published: September 2019

After the Islamic Revolution in 1979, patriarchal, religiously oriented rules discriminated against women’s rights and changed their position in society and politics. Islamic feminism in Iran as a post-revolutionary discourse deals with this issue and, at the same time, seeks a new alternatives in the contemporary interpretation of religious norms and those influenced by religion.
This work reflects on the mindset and argumentation of various social actors in the debate on women’s rights in Iran since the emergence of the Islamic Republic, in particular on the positions of male thinkers. Furthermore, using the career, biography and publications of each respective actor, the study reconstructs what they base their arguments on and from which perspective they substantiate their points of view. The mindset and reasoning of these thinkers determine their positions in the women’s rights debate on the realisation of reform. In contrast to conservatives, with their clear notion of women’s rights, religiously progressive and liberal secular thinkers place the liberation of women from a prescribed patriarchal system and the restoration of women’s self-confidence at the centre of political and social life.
Id4 promotes the elimination of the pro-activation factor Ascl1 to maintain quiescence of adult hippocampal stem cells
Authors: Blomfield Isabelle Maria , Rocamonde Brenda , Masdeu Maria del Mar , Mulugeta Eskeatnaf , Vaga Stefania , van den Berg Debbie LC , Huillard Emmanuelle , Guillemot François , Urbán Noelia
Published: September 2019

Quiescence is essential for the long-term maintenance of adult stem cells but how stem cells maintain quiescence is poorly understood. Here, we show that neural stem cells (NSCs) in the adult mouse hippocampus actively transcribe the pro-activation factor Ascl1 regardless of their activated or quiescent states. We found that the inhibitor of DNA binding protein Id4 is enriched in quiescent NSCs and that elimination of Id4 results in abnormal accumulation of Ascl1 protein and premature stem cell activation. Accordingly, Id4 and other Id proteins promote elimination of Ascl1 protein in NSC cultures. Id4 sequesters Ascl1 heterodimerization partner E47, promoting Ascl1 protein degradation and stem cell quiescence. Our results highlight the importance of non-transcriptional mechanisms for the maintenance of NSC quiescence and reveal a role for Id4 as a quiescence-inducing factor, in contrast with its role of promoting the proliferation of embryonic neural progenitors.
Coordinating a new approach to basic research into Parkinson’s disease
Authors: Schekman Randy , Riley Ekemini AU
Published: September 2019

The Aligning Science Across Parkinson’s (ASAP) initiative is building an international network of researchers to improve our understanding of the biology underlying Parkinson's disease. Developing a better understanding of how the disease originates and progresses will, we hope, lead to new therapies. The ASAP initiative will incentivize collaboration between the existing PD research community and other researchers and will be committed to open-science practices.
Brodifacoum does not modulate human cannabinoid receptor-mediated hyperpolarization of AtT20 cells or inhibition of adenylyl cyclase in HEK 293 cells
Authors: Sachdev Shivani , Boyd Rochelle , Grimsey Natasha L. , Santiago Marina , Connor Mark
Published: September 2019

Background

Synthetic cannabinoids are a commonly used class of recreational drugs that can have significant adverse effects. There have been sporadic reports of co-consumption of illicit drugs with rodenticides such as warfarin and brodifacoum (BFC) over the past 20 years but recently, hundreds of people have been reported to have been poisoned with a mixture of synthetic cannabinoids and BFC. We have sought to establish whether BFC directly affects cannabinoid receptors, or their activation by the synthetic cannabinoid CP55940 or the phytocannabinoid Δ9-tetrahydrocannabinol (Δ9-THC).

Methods

The effects of BFC on the hyperpolarization of wild type AtT20 cells, or AtT20 cells stably expressing human CB1- or CB2- receptors, were studied using a fluorescent assay of membrane potential. The effect of BFC on CB1- and CB2-mediated inhibition of forskolin-stimulated adenylyl cyclase (AC) activation was measured using a BRET assay of cAMP levels in HEK 293 cells stably expressing human CB1or CB2.

Results

BFC did not activate CB1or CB2receptors, or affect the hyperpolarization of wild type AtT20 cells produced by somatostatin. BFC (1 µM) did not affect the hyperpolarization of AtT20-CB1or AtT20-CB2cells produced by CP55940 or Δ9-THC. BFC (1 µM) did not affect the inhibition of forskolin-stimulated AC activity by CP55940 in HEK 293 cells expressing CB1or CB2. BFC (1 µM) also failed to affect the desensitization of CB1and CB2signaling produced by prolonged (30 min) application of CP55940 or Δ9-THC to AtT20 cells.

Discussion

BFC is not a cannabinoid receptor agonist, and appeared not to affect cannabinoid receptor activation. Our data suggests there is no pharmacodynamic rationale for mixing BFC with synthetic cannabinoids; however, it does not speak to whether BFC may affect synthetic cannabinoid metabolism or biodistribution. The reasons underlying the mixing of BFC with synthetic cannabinoids are unknown, and it remains to be established whether the “contamination” was deliberate or accidental. However, the consequences for people who ingested the mixture were often serious, and sometimes fatal, but this seems unlikely to be due to BFC action at cannabinoid receptors.
Conserved core tryptophans of FnII domains are crucial for the membranolytic and chaperone‐like activities of bovine seminal plasma protein PDC‐109
Authors: Singh Bhanu P. , Asthana Abhishek , Basu Amrita , Tangirala Ramakrishna , Mohan Rao Chintalagiri , Swamy Musti J.
Published: September 2019

The fibronectin type II (FnII) domain, present in diverse vertebrate proteins, plays crucial roles in several fundamental biological processes. PDC‐109, the major bovine seminal plasma protein, contains two FnII domains that bind to choline phospholipids on sperm plasma membrane and induce lipid efflux crucial for successful fertilization. PDC‐109 also exhibits chaperone‐like activity and protects other proteins against various types of stress. Here, we show that a core tryptophan residue is highly conserved across species in the FnII domains. Mutation of conserved tryptophan residues W47, W93, and W106 in the FnII domains of PDC‐109 to alanine leads to drastic decrease or complete abolition of membrane‐binding and chaperone‐like activities. These observations suggest that conserved tryptophans are important for the function of FnII proteins.
Acceptance and verification of the Halcyon‐Eclipse linear accelerator‐treatment planning system without 3D water scanning system
Authors: Gao Song , Netherton Tucker , Chetvertkov Mikhail A. , Li Yuting , Court Laurence E. , Simon William E. , Shi Jie , Balter Peter A.
Published: September 2019

We tested whether an ionization chamber array (ICA) and a one‐dimensional water scanner (1DS) could be used instead of a three‐dimensional water scanning system (3DWS) for acceptance testing and commissioning verification of the Varian Halcyon–Eclipse Treatment Planning System (TPS). The Halcyon linear accelerator has a single 6‐MV flattening‐filter‐free beam and a nonadjustable beam model for the TPS. Beam data were measured with a 1DS, ICA, ionization chambers, and electrometer. Acceptance testing and commissioning were done simultaneously by comparing the measured data with TPS‐calculated percent‐depth‐dose (PDD) and profiles. The ICA was used to measure profiles of various field sizes (10‐, 20‐, and 28 cm2) at depths of dmax (1.3 cm), 5‐, 10‐, and 20 cm. The 1DS was used for output factors (OFs) and PDDs. OFs were measured with 1DS for various fields (2–28 cm2) at a source‐to‐surface distance of 90 cm. All measured data were compared with TPS‐calculations. Profiles, off‐axis ratios (OAR), PDDs and OFs were also measured with a 3DWS as a secondary check. Profiles between the ICA and TPS (ICA and 3DWS) at various depths across the fields indicated that the maximum discrepancies in high‐dose and low‐dose tail were within 2% and 3%, respectively, and the maximum distance‐to‐agreement in the penumbra region was <3 mm. The largest OAR differences between ICA and TPS (ICA and 3DWS) values were 0.23% (−0.25%) for a 28 × 28 cm2 field, and the largest point‐by‐point PDD differences between 1DS and TPS (1DS and 3DWS) were −0.41% ± 0.12% (−0.32% ± 0.17%) across the fields. Both OAR and PDD showed the beam energy is well matched to the TPS model. The average ratios of 1DS‐measured OFs to the TPS (1DS to 3DWS) values were 1.000 ± 0.002 (0.999 ± 0.003). The Halcyon–Eclipse system can be accepted and commissioned without the need for a 3DWS.
Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques
Authors: Ako Rajour Tanyi , Upadhyay Aditi , Withayachumnankul Withawat , Bhaskaran Madhu , Sriram Sharath
Published: September 2019

Manipulation of terahertz radiation opens new opportunities that underpin application areas in communication, security, material sensing, and characterization. Metasurfaces employed for terahertz manipulation of phase, amplitude, or polarization of terahertz waves have limitations in radiation efficiency which is attributed to losses in the materials constituting the devices. Metallic resonators‐based terahertz devices suffer from high ohmic losses, while dielectric substrates and spacers with high relative permittivity and loss tangent also reduce bandwidth and efficiency. To overcome these issues, a proper choice of low loss and low relative permittivity dielectric layers and substrates can improve field confinement and reduce dissipation. Alternatively, replacing metallic resonators with a moderate relative permittivity dielectric material that supports cavity mode resonances also reduces dissipation due to the absence of conduction current. Herein, an overview of dielectric materials employed as spacers and dielectric resonators is provided, and the fabrication methods employed to realize these devices at the terahertz frequency range are also presented. Material selection guidelines, material‐specific and application‐specific fabrication quality metrics are outlined, and new techniques are proposed.
An Electrophilic Ruthenium Complex that Enables the Cycloisomerization of 1,6‐Enynes to Access Azabicyclo[4.1.0]heptenes
Authors: Liu Rui , Yang Dongfeng , Chang Fengwei , Giordano Laurent , Liu Guohua , Tenaglia Alphonse
Published: September 2019

Cycloisomerization of 1,6‐enynes to access azabicyclo[4.1.0]heptenes was achieved in the presence of commercially available [RuCl2(CO)3]2 after a comprehensive study on the electronic properties of ruthenium complexes. A series of 1,6‐enynes bearing an internal/terminal alkyne motif proved to be good candidates for substrates, giving their corresponding bicyclo[4.1.0]heptenes in good to excellent yields. Substitution patterns on either alkyne or alkene have no significant influence on the yields of bicyclic adducts.
Light‐Induced Mechanistic Divergence in Gold(I) Catalysis: Revisiting the Reactivity of Diazonium Salts
Authors: Taschinski Svenja , Döpp René , Ackermann Martin , Rominger Frank , de Vries Folkert , Menger Maximilian F. S. J. , Rudolph Matthias , Hashmi A. Stephen K. , Klein Johannes E. M. N.
Published: September 2019

In a systematic study of the Au‐catalyzed reaction of o‐alkynylphenols with aryldiazonium salts, we find that essentially the same reaction conditions lead to a change in mechanism when a light source is applied. If the reaction is carried out at room temperature using a AuI catalyst, the diazonium salt undergoes electrophilic deauration of a vinyl AuI intermediate and provides access to substituted azobenzofurans. If the reaction mixture is irradiated with blue LED light, C−C bond formation due to N2‐extrusion from the diazonium salt is realized selectively, using the same starting materials without the need for an additional photo(redox) catalyst under aerobic conditions. We report a series of experiments demonstrating that the same vinyl AuI intermediate is capable of producing the observed products under photolytic and thermal conditions. The finding that a vinyl AuI complex can directly, without the need for an additional photo(redox) catalyst, result in C−C bond formation under photolytic conditions is contrary to the proposed mechanistic pathways suggested in the literature till date and highlights that the role of oxidation state changes in photoredox catalysis involving Au is thus far only poorly understood and may hold surprises for the future. Computational results indicate that photochemical activation can occur directly from a donor–acceptor complex formed between the vinyl AuI intermediate and the diazonium salt.
Expedient Synthesis of Core Disaccharide Building Blocks from Natural Polysaccharides for Heparan Sulfate Oligosaccharide Assembly
Authors: Pawar Nitin J. , Wang Lei , Higo Takuya , Bhattacharya Chandrabali , Kancharla Pavan K. , Zhang Fuming , Baryal Kedar , Huo Chang‐Xin , Liu Jian , Linhardt Robert J. , Huang Xuefei , Hsieh‐Wilson Linda C.
Published: September 2019

The complex sulfation motifs of heparan sulfate glycosaminoglycans (HS GAGs) play critical roles in many important biological processes. However, an understanding of their specific functions has been hampered by an inability to synthesize large numbers of diverse, yet defined, HS structures. Herein, we describe a new approach to access the four core disaccharides required for HS/heparin oligosaccharide assembly from natural polysaccharides. The use of disaccharides rather than monosaccharides as minimal precursors greatly accelerates the synthesis of HS GAGs, providing key disaccharide and tetrasaccharide intermediates in about half the number of steps compared to traditional strategies. Rapid access to such versatile intermediates will enable the generation of comprehensive libraries of sulfated oligosaccharides for unlocking the “sulfation code” and understanding the roles of specific GAG structures in physiology and disease.
Autonome Entdeckung in den chemischen Wissenschaften, Teil I: Fortschritt
Authors: Coley Connor W. , Eyke Natalie S. , Jensen Klavs F.
Published: September 2019

In dem zweiteiligen Aufsatz wird der Beitrag von Automation zu verschiedenen Aspekten der chemischen Entdeckung untersucht. In Teil 1 definieren wir die Arten von Entdeckung in den chemischen Wissenschaften – Entdeckung von Materie (Molekülen, Materialien, Gegenständen), Entdeckung von Prozessen und Entdeckung von Modellen – und beschreiben ihre Vereinheitlichung als Suchproblem. Anschließend formulieren wir eine Reihe von Fragen, die für die Bewertung des Autonomiegrads einer Entdeckung relevant sind. Den Abschluss bilden zahlreiche Fallstudien in den Bereichen Synthesechemie, Wirkstoffentdeckung, anorganische Chemie und Materialwissenschaften, bei denen Entdeckungen durch Rechenunterstützung und Automation beschleunigt oder erst ermöglicht werden. Die Studien machen deutlich, wie die rasanten Entwicklungen in der Hardware‐Automation und im maschinellen Lernen unaufhörlich die Art der experimentellen Forschung und der Modellierung verändern. Im zweiten Teil werden anhand der Fallstudien die noch ungelösten Aufgaben auf dem Gebiet benannt und diskutiert.
Autonome Entdeckung in den chemischen Wissenschaften, Teil II: Ausblick
Authors: Coley Connor W. , Eyke Natalie S. , Jensen Klavs F.
Published: September 2019

In dem zweiteiligen Aufsatz wird der Beitrag von Automation zu verschiedenen Aspekten der chemischen Entdeckung untersucht. In Teil 2 betrachten wir ausgewählte Beispiele. Eine Diskussion der Rolle von Automation und Rechnung im wissenschaftlichen Prozess und deren Einfluss auf die Beschleunigung von Entdeckungsaufgaben wird immer wichtiger. Selbst wenn automatisierte Systeme die Laborarbeit immens unterstützen können, kann man argumentieren, dass auch die besten Roboter noch nicht wirklich etwas “entdecken”. Zur effektiven Entwicklung autonomer Plattformen müssen wir ihren bisherigen Einsatz evaluieren und herausfinden, wie sie sich auf künftige Probleme anwenden lassen. Den Hauptteil dieses Aufsatzes nimmt die Definition von weiterführenden Forschungsrichtungen ein: Verarbeitung komplexer Daten, Erstellung empirischer Modelle, Automation experimenteller und rechnerischer Validierung, Versuchsauswahl und Evaluation des Fortschritts auf dem Weg zur autonomen Entdeckung.
Autonomous Discovery in the Chemical Sciences Part I: Progress
Authors: Coley Connor W. , Eyke Natalie S. , Jensen Klavs F.
Published: September 2019

This two‐part Review examines how automation has contributed to different aspects of discovery in the chemical sciences. In this first part, we describe a classification for discoveries of physical matter (molecules, materials, devices), processes, and models and how they are unified as search problems. We then introduce a set of questions and considerations relevant to assessing the extent of autonomy. Finally, we describe many case studies of discoveries accelerated by or resulting from computer assistance and automation from the domains of synthetic chemistry, drug discovery, inorganic chemistry, and materials science. These illustrate how rapid advancements in hardware automation and machine learning continue to transform the nature of experimentation and modeling. Part two reflects on these case studies and identifies a set of open challenges for the field.
Engaging Aldehydes in CuH‐Catalyzed Reductive Coupling Reactions: Stereoselective Allylation with Unactivated 1,3‐Diene Pronucleophiles
Authors: Li Chengxi , Shin Kwangmin , Liu Richard Y. , Buchwald Stephen L.
Published: September 2019

Recently, CuH‐catalyzed reductive coupling processes involving carbonyl compounds and imines have become attractive alternatives to traditional methods for stereoselective addition because of their ability to use readily accessible and stable olefins as surrogates for organometallic nucleophiles. However, the inability to use aldehydes, which usually reduce too rapidly in the presence of copper hydride complexes to be viable substrates, has been a major limitation. Shown here is that by exploiting relative concentration effects through kinetic control, this intrinsic reactivity can be inverted and the reductive coupling of 1,3‐dienes with aldehydes achieved. Using this method, both aromatic and aliphatic aldehydes can be transformed into synthetically valuable homoallylic alcohols with high levels of diastereo‐ and enantioselectivities, and in the presence of many useful functional groups. Furthermore, using a combination of theoretical (DFT) and experimental methods, important mechanistic features of this reaction related to stereo‐ and chemoselectivities were uncovered.
Adjusting Simon's optimal two‐stage design for heterogeneous populations based on stratification or using historical controls
Authors: Edelmann Dominic , Habermehl Christina , Schlenk Richard F. , Benner Axel
Published: September 2019

In many cancer studies, the population under consideration is highly heterogeneous in terms of clinical, demographical, and biological covariates. As the covariates substantially impact the individual prognosis, the response probabilities of patients entering the study may strongly vary. In this case, the operating characteristics of classical clinical trial designs heavily depend on the covariates of patients entering the study. Notably, both type I and type II errors can be much higher than specified. In this paper, two modifications of Simon's optimal two‐stage design correcting for heterogeneous populations are derived. The first modification assumes that the patient population is divided into a finite number of subgroups, where each subgroup has a different response probability. The second approach uses a logistic regression model based on historical controls to estimate the response probabilities of patients entering the study. The performance of both approaches is demonstrated using simulation examples.
Exploring the Influence of Halogen Coordination Effect of Stable Bimetallic MOFs on Oxygen Evolution Reaction
Authors: Lu Jia‐Ni , Liu Jiang , Dong Long‐Zhang , Li Shun‐Li , Kan Yu‐He , Lan Ya‐Qian
Published: September 2019

The energy crisis and environmental pollution have forced scientists to explore alternative energy conversion and storage devices. The anodic reactions of these devices are all oxygen evolution reactions (OER), so the development of efficient OER electrocatalysts is of great significance. At the same time, understanding the reaction mechanism of OER is conducive to the rational design of efficient OER electrocatalysts. In general, catalytic active centers play a direct role in OER performance. In this paper, a series of stable bimetallic metal–organic frameworks (MOFs, named as Fe3‐Con‐X2, n=2, 3 and X=F, Cl, Br) with similar structure were synthesized by changing the halogen coordinated with the cobalt metal active center, aiming to investigate the influence of halogen substitution effect on OER performance. It was found that the OER activity of Fe3‐Co3‐F2 is much better than Fe3‐Co2‐Cl2 and Fe3‐Co2‐Br2, indicating that the regulation of the electronegativity change of the coordination halogen atom can regulate the coordination electron structure of the metal active center, thereby achieving effective regulation of OER performance.
Investigation of Active and Inactivated Yeast Cells by Scanning Electrochemical Impedance Microscopy
Authors: Valiūnienė Aušra , Petronienė Jūratė , Dulkys Mindaugas , Ramanavičius Arūnas
Published: September 2019

Scanning electrochemical microscopy (SECM), electrochemical impedance spectroscopy (EIS) and scanning electrochemical impedance microscopy (SEIM) were used to investigate electrochemical activity of active and inactivated yeast Saccharomyces cerevisiae cells. SEIM experiment was performed using a unique electrochemical impedance spectrometer with a fast Fourier transform (FFT‐EIS) function, which enabled simultaneously perturb/evaluate electrochemical system at 50 frequencies. This allowed very quick observing the differences between impedance spectra, which were taken every few seconds. Therefore, we were able to apply SEIM for relatively fast determination of electrochemical impedance dependence on the distance between ultramicroelectrode (UME) and surface modified by immobilized yeast cells. It was determined that electrochemical activity and ‘breathing’ (a consumption of dissolved oxygen) of yeast can be electrochemically observed when the distance between UME and surface of yeast cells is in the range from 0 μm to 25 μm. Therefore, 25 μm is the maximum distance suitable for efficient investigation of yeast cell activity when experiments are performed in FFT‐SEIM mode. Charge transfer resistance of active and inactivated yeast cells was determined using EIS. It was calculated that charge transfer resistance of active yeast cells is 1.5 times lower than that of inactivated yeast cells. Lipophilic vitamin K3 (Vit‐K3) and hydrophilic vitamin K1 (Vit‐K1) were mixtured and used as redox mediators for charge transfer from yeast cells.
QSAR-Based Estimation of Species Sensitivity Distribution Parameters: An Exploratory Investigation
Authors: Hoondert Renske P.J. , Oldenkamp Rik , de Zwart Dick , van de Meent Dik , Posthuma Leo
Published: September 2019

Ecological risk assessments are hampered by limited availability of ecotoxicity data. The present study aimed to explore the possibility of deriving species sensitivity distribution (SSD) parameters for nontested compounds, based on simple physicochemical characteristics, known SSDs for data-rich compounds, and a quantitative structure–activity relationship (QSAR)-type approach. The median toxicity of a data-poor chemical for species assemblages significantly varies with values of the physicochemical descriptors, especially when based on high-quality SSD data (from either acute median effect concentrations or chronic no-observed-effect concentrations). Beyond exploratory uses, we discuss how the precision of QSAR-based SSDs can be improved to construct models that accurately predict the SSD parameters of data-poor chemicals. The current models show that the concept of QSAR-based SSDs supports screening-level evaluations of the potential ecotoxicity of compounds for which data are lacking. Environ Toxicol Chem 2019;38:2764–2770. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC

Abstract

Extrapolation of data for species sensitivity distribution (SSD) parameters (mu and sigma) using a QSAR approach (estimating SSD parameters based on physicochemical characteristics) may in the end result in filling in data gaps for - in theory - all chemicals. QSAR = quantitative structure–activity relationship; SSD = species sensitivity distribution.
Low antithrombin activity before delivery predicts subsequent hypertensive disorders in pregnancy
Authors: Morikawa Mamoru , Umazume Takeshi , Nakagawa Kinuko , Chiba Kentaro , Kawaguchi Satoshi , Watari Hidemichi
Published: September 2019

Objective

To examine whether laboratory parameters can predict the onset of recurrent hypertensive disorders of pregnancy (HDP).

Methods

A retrospective study of 257 women with consecutive deliveries at a hospital in Sapporo, Japan, between 2009 and 2017. Women were divided into four groups according to whether or not they had HDP in the first and second peripartum periods (HDP‐HPD, HDP‐Non, Non‐HDP, Non‐Non). HDP was defined as gestational hypertension and/or proteinuria. Laboratory parameters measured on the day of or 1 day before delivery were compared between peripartum‐1 and peripartum‐2.

Results

Frequency of HDP in peripartum‐2 was higher among the 24 (9.3%) women with HPD in peripartum‐1 (6/24, 25.0%) than among the 233 (90.7%) women without (3/233, 1.3%) (P<0.001). In peripartum‐1, women with HDP had lower median antithrombin activity than those without (74% vs 89%, P=0.021). Antithrombin activity in peripartum‐1 was also lower in the HDP‐HDP (67%) than in the HDP‐Non (79%) group (P=0.021). Antithrombin activities of 77% or less at the first delivery predicted HDP in peripartum‐1 (P<0.001) and 70% or less predicted HDP in peripartum‐2 (P=0.018).

Conclusion

Women with HDP in peripartum‐1 had a higher incidence of HDP recurrence. Low antithrombin before a first delivery might predict recurrent HDP in a second pregnancy.
Periodontal disease, sleep duration, and white blood cell markers in the 2009 to 2014 National Health and Nutrition Examination Surveys
Authors: Beydoun Hind A. , Hossain Sharmin , Beydoun May A. , Weiss Jordan , Zonderman Alan B. , Eid Shaker M.
Published: September 2019

Background

Elevated levels of inflammatory biomarkers are consistently associated with chronic conditions, for which periodontitis and sleep are established risk factors. We examined the relationships between periodontitis, hours of sleep and white blood cell (WBC) markers among a nationally representative sample of US adults.

Methods

Cross‐sectional study using existing demographic, examination, laboratory and questionnaire data on 11,813 participants (5,814 men and 5,999 women, mean age ± SE; range: 52.74 ± 0.24; 30 to 80 years) from the 2009 to 2014 National Health and Nutrition Examination Surveys. Unadjusted, sex‐ and age‐adjusted, as well as fully adjusted linear and logistic regression models were conducted in addition to generalized structural equations models, while considering sampling design complexity. β, odds ratios with their 95% confidence intervals, indirect effects and mediation proportions were estimated.

Results

The weighted mean WBC count was 7,130 cells/µL, with the WBC 5‐part differential estimated in terms of percentages of lymphocytes (29.50%), monocytes (7.99%), neutrophils (59.03%), eosinophils (2.84%), and basophils (71.88%). Furthermore, 36.2% of participants reported <7 hours of sleep and 49.8% had periodontitis. In fully adjusted models controlling for sociodemographic, lifestyle, and health characteristics, neither WBC markers nor periodontitis were related to hours of sleep. By contrast, periodontitis was directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men. However, the relationship of periodontitis with %neutrophils and %lymphocytes may be modified by hours of sleep, as it was specific to individuals reporting ≥7 hours of sleep.

Conclusion

Periodontitis may be directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men and individuals reporting ≥7 hours of sleep, with implications for primary and secondary prevention.
Resource Loss and Stress Outcomes in a Setting of Chronic Conflict: The Conservation of Resources Theory in the Eastern Congo
Authors: Snyder Jordan D. , Boan David , Aten Jamie D. , Davis Edward B. , Van Grinsven Leif , Liu Tao , Worthington Everett L.
Published: September 2019

The purpose of this cross‐sectional study was to examine conservation of resources (COR) theory in the context of armed conflict in Africa. Specifically, within the setting of ongoing chronic conflict in the eastern Democratic Republic of the Congo (DRC), we tested the COR theory prediction that resource loss contributes to various stress outcomes. A randomly selected sample of 312 adults (125 men, 187 women) from villages in North Kivu, DRC completed orally administered measures of resource loss, daily stressors, and four stress outcomes: depression symptoms, anxiety symptoms, posttraumatic distress, and general distress. Consistent with COR theory, resource loss predicted all four stress outcomes above and beyond the contribution of demographics, relocation experiences, and daily stressors; however, this effect was small, ΔR2 = .02–.06. The most consistent and strongest predictors of stress outcomes were daily stressors, βs = .42–.62; number of relocation experiences, βs = .33–.43; and psychosocial resource loss (e.g., loss of hope, meaning or purpose in life, intimacy with friends and family, physical health of family), βs = .17–.26. Additionally, male sex predicted depression, anxiety, and trauma symptoms, and lower educational status predicted anxiety symptoms and general distress. Our exploratory mediation analysis showed that daily stressors partially mediated all four pairs of associations between psychosocial resource loss and mental health outcomes. We discuss the findings with consideration of research on disasters generally and armed conflicts specifically. We also discuss implications for humanitarian interventions with conflict‐affected populations in Africa and beyond.
A reduction‐dependent copper uptake pathway in an oceanic diatom
Authors: Kong Liangliang , Price Neil M.
Published: September 2019

Copper(II) is reduced to Cu(I) extracellularly by marine and freshwater phytoplankton, but its biological significance is not firmly established. We studied the relationship between Cu(II) reduction and uptake in Thalassiosira oceanica, a diatom that was recently shown to possess functional copper uptake transporters (CTRs) that take up Cu(I). Inorganic and organic complexes of Cu(II) were reduced directly by reactions at the cell surface in proportion to Cu(II)‐ligand reduction potential. The rates of reduction were enhanced twofold in Cu‐limited cells, suggesting reduction was regulated by Cu nutritional state. Suppressing Cu(II) reduction caused a decrease in Cu uptake rate by 97% and addition of a Cu(I) complexing agent completely inhibited cell division and reduced Cu quota when Cu concentration was growth limiting. Thus, Cu(II) reduction was an obligatory first step in Cu uptake. Cu(II) reduction rate and growth rate of T. oceanica were proportional to Cu–ethylenediaminetetraacetic acid concentration and independent of inorganic Cu concentration in bulk solution. The results suggest that Cu(II) bound to organic ligands was reduced by extracellular cupric reductases and subsequently internalized. This reduction‐dependent uptake pathway may enable diatoms to use naturally occurring Cu(II) organic complexes in the sea.
Chemoselective Thioacetalisation and Transthioacetalisation of Aldehydes Catalyzed by PVP‐I
Authors: Hu Peng‐Fei , Dong Bin , Zhou Zhi‐Peng , Chen Wei‐Dong , Zeng Bu‐Bing
Published: September 2019

Thioacetals of various aldehydes were obtained directly from aldehydes or by a transthioacetalisation process from O,O‐acetals catalyzed by Povidone‐iodine (PVP−I) with good to excellent yields. Attractive features of this method include mild reaction conditions, low catalyst loading, recyclability of catalyst, facile purification of products, and high synthetic efficiency.
Maiaspora: a new miospore genus with enigmatic sculpture from the late Visean of European Russia
Authors: Mamontov Dmitriy A. , McLean Duncan , Orlova Olga A. , Gavrilova Olga A.
Published: September 2019

A new miospore genus, Maiaspora, is described from the upper Visean (middle Mississippian) of the southern wing of Moscow Syneclise (European Russia). Applying a combination of methods (optical light microscopy (LM), scanning‐electron microscopy, confocal laser microscopy (CLSM) and image analysis) to the same individual miospore specimens revealed a remarkable sculptural type for which we propose the new term ‘metareticuloid’. Metareticuloid sculpture is defined as a complex arrangement of muri with apiculate elements, polygonal lumina and circular scrobiculae at the base of the lumina. The discovery of fossil spores with metareticuloid sculpture allows the recognition of clear morphological differences between microreticulate and foveolate sculptures, which palynologists have historically had difficulty in separating. Virtual cross‐sections provided by CLSM show that miospores with metareticuloid sculpture display perfectly preserved, funnel‐shaped tunnels (like a gallery of cave stalactites) in the deep exospore. In contrast, miospores with microreticulate or reticulate and partly vermiculate sculpture lack such vertical tunnels (termed scrobiculae). The morphology of Maiaspora gen. nov. is considered in comparison with Microreticulatisporites (Knox non sensu Potonié & Kremp) Bhardwaj emended Oshurkova, Pseudoreticulatispora Bharadwaj & Srivastava emended Price & Foster, Vadaszisporites (Deák & Combaz) emended Juhász, Foveosporites Balme, Foveotriletes van der Hammen ex Potonié, Garotriletes Singh & Singh, Assamiasporites Mehrota & Sah, and Margotriletes Mehrota & Sah. The morphological conceptions of Microreticulatisporites and Foveotriletes are reinterpreted by numerical typification. The adaptative significance of metareticuloid sculpture is discussed in relation to modern and fossil spores, and in terms of harmomegathic mechanisms of angiosperm pollen.
Ruling Parties in Authoritarian Regimes: Rethinking Institutional Strength
Authors: Meng Anne
Published: September 2019

A key finding in the literature on authoritarian regimes is that leaders frequently rely on ruling parties to stay in power, but the field lacks systematic ways to measure autocratic party strength. As a result, it is not clear how often ruling parties are actually strong and capable of carrying out important functions. This article demonstrates that strong ruling parties are much rarer than is typically assumed. Using a global sample of dictatorships from 1946–2008, the author shows that most ruling parties are unable to survive the death or departure of the founding leader. This is true even of many ruling parties that have been coded as leading single-party regimes. While strong parties may be key to durable authoritarianism, relatively few parties are truly strong.
Comparative study of leaf antioxidant activity as a possible mechanism for frost tolerance in ‘Hass’ and ‘Ettinger’ avocado cultivars
Authors: Weil A. , Sofer-Arad C. , Bar-Noy Y. , Liran O. , Rubinovich L.
Published: September 2019

A major drawback of avocado (Persea americanaMill.) is susceptibility to frosts, which reduces yields and limits its geographic distribution and market growth. Whereas the frost-susceptible cultivar ‘Hass’ leads the global avocado market, cv. ‘Ettinger’, although commercially less important, is considered frost-tolerant. The mechanism behind the greater frost tolerance of ‘Ettinger’ has not yet been elucidated; therefore, the aim of the current study was to evaluate the differences between the frost responses of the two cultivars. The results showed that detached ‘Ettinger’ branches had greater tolerance than ‘Hass’ to controlled frost stress. Tissue browning caused by methyl viologen oxidative cell damage, superoxide accumulation in leaf discs following wounding and browning of cut surfaces in branches were much lower in ‘Ettinger’ than in ‘Hass’, suggesting greater antioxidant activity (AA) in the former. In leaf extracts, AA was significantly higher in ‘Ettinger’ than in ‘Hass’, but osmolarity was similar in the two cultivars. Total phenolics content was significantly higher in ‘Ettinger’ but addition of a protein mask did not significantly reduce AA in either cultivar. Interestingly, following the freezing treatment, AA increased in ‘Ettinger’ and remained almost unchanged in ‘Hass’, while osmolarity was unaffected in either cultivar. These results suggest that the greater frost-tolerance of ‘Ettinger’ than ‘Hass’ is due largely to its greater AA, which springs mainly from a non-enzymatic source, i.e. accumulation of phenolic compounds. Based on the current study, future applications may be developed to minimize frost damage in avocado orchards.