bluuebunny/crossref_metadata_2025_split huggingface dataset:
Violence in hunters, fishermen, and gatherers of the Chinchorro culture: Archaic societies of the Atacama Desert (10,000–4,000 cal yr BP)
Authors: Standen Vivien G. , Santoro Calogero M. , Arriaza Bernardo , Coleman Drew , Monsalve Susana , Marquet Pablo A. 
Published: January 2020

AbstractObjectivesThis article addresses evidence of violence imbedded in both soft and hard tissues from early populations of hunters, fishermen, and gatherers, known as the Chinchorro culture, who lived between 10,000 and 4,000 cal yr BP, along the coast of the Atacama Desert, one of the driest environments on Earth. Our study is aimed to test two hypotheses (a) that interactions and violent behaviors increased through time as population density and social complexity augmented; and (b) that violence was more prevalent between local Chinchorro groups and groups from other inland locations.Material and MethodsTwo lines of data were analyzed: (1) bioarchaeology, through the quantification of physical traces of interpersonal violence in skeletons and mummies from a sample of 136 adult individuals and, (2) isotopic chemical analysis (strontium) of individuals with traces of trauma in order to determine their local or foreign origin.ResultsViolence among Chinchorro populations was ubiquitous and remained invariant over time, with a remarkable skew to male (about 25% above female across the complete sample). Moreover, the chemical signature of individuals with traces of violence was not of foreign origin.DiscussionThe violence exerted by the Chinchorro groups was not related to increased population size, nor social complexity and was mostly restricted to individuals coming from the same coastal habitat. That is, our data suggest that violence was constant across the Archaic period among the Chinchorro, implying that violent behavior was part of the sociocultural repertory of these populations, likely associated to mechanisms to resolve conflicts and social tensions.
Cation Diffusion Guides Hybrid Halide Perovskite Crystallization during the Gel Stage
Authors: Liu Lang , Bai Yang , Zhang Xiao , Shang Yuequn , Wang Chenyue , Wang Hao , Zhu Cheng , Hu Chen , Wu Jiafeng , Zhou Huanping , Li Yujing , Yang Shihe , Ning Zhijun , Chen Qi 
Published: January 2020

AbstractLead halide perovskites with mixed cations/anions often suffer from phase segregation, which is detrimental to device efficiency and their long‐term stability. During perovskite film growth, the gel stage (in between liquid and crystalline) correlates to phase segregation, which has been rarely explored. Herein, cation diffusion kinetics are systematically investigated at the gel stage to develop a diffusion model obeying Fick's second law. Taking 2D layered perovskite as an example, theoretical and experimental results reveal the impact of diffusion coefficient, temperature, and gel duration on the film growth and phase formation. A homogenous 2D perovskite thin film was then fabricated without significant phase segregation. This in‐depth understanding of gel stage and relevant cation diffusion kinetics would further guide the design and processing of halide perovskites with mixed composition to meet requirements for optoelectronic applications.
Whole‐Cell Photoenzymatic Cascades to Synthesize Long‐Chain Aliphatic Amines and Esters from Renewable Fatty Acids
Authors: Cha Hee‐Jeong , Hwang Se‐Yeun , Lee Da‐Som , Kumar Akula Ravi , Kwon Yong‐Uk , Voß Moritz , Schuiten Eva , Bornscheuer Uwe T. , Hollmann Frank , Oh Deok‐Kun , Park Jin‐Byung 
Published: January 2020

AbstractLong‐chain aliphatic amines such as (S,Z)‐heptadec‐9‐en‐7‐amine and 9‐aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole‐cell cascade reactions using the combination of an alcohol dehydrogenase (ADH) from Micrococcus luteus, an engineered amine transaminase from Vibrio fluvialis (Vf‐ATA), and a photoactivated decarboxylase from Chlorella variabilis NC64A (Cv‐FAP) in a one‐pot process. In addition, long chain aliphatic esters such as 10‐(heptanoyloxy)dec‐8‐ene and octylnonanoate were prepared from ricinoleic acid and oleic acid, respectively, by using the combination of the ADH, a Baeyer–Villiger monooxygenase variant from Pseudomonas putida KT2440, and the Cv‐FAP. The target compounds were produced at rates of up to 37 U g−1 dry cells with conversions up to 90 %. Therefore, this study contributes to the preparation of industrially relevant long‐chain aliphatic chiral amines and esters from renewable fatty acid resources.
Redox‐Triggered Chirality Switching and Guest‐Capture/Release with a Pillar[6]arene‐Based Molecular Universal Joint
Authors: Xiao Chao , Wu Wanhua , Liang Wenting , Zhou Dayang , Kanagaraj Kuppusamy , Cheng Guo , Su Dan , Zhong Zhihui , Chruma Jason J. , Yang Cheng 
Published: January 2020

AbstractA chiral electrochemically responsive molecular universal joint (EMUJ) was synthesized by fusing a macrocyclic pillar[6]arene (P[6]) to a ferrocene‐based side ring. A single crystal of an enantiopure EMUJ was successfully obtained, which allowed, for the first time, the definitive correlation between the absolute configuration and the circular dichroism spectrum of a P[6] derivative to be determined. The self‐inclusion and self‐exclusion conformational change of the EMUJ led to a chiroptical inversion of the P[6] moiety, which could be manipulated by both solvents and changes in temperature. The EMUJ also displayed a unique redox‐triggered reversible in/out conformational switching, corresponding to an occupation/voidance switching of the P[6] cavity, respectively. This phenomenon is an unprecedented electrochemical manipulation of the capture and release of guest molecules by supramolecular hosts.
Photoredox Catalysis of Aromatic β‐Ketoesters for in Situ Production of Transient and Persistent Radicals for Organic Transformation
Authors: Yang Xiu‐Long , Guo Jia‐Dong , Xiao Hongyan , Feng Ke , Chen Bin , Tung Chen‐Ho , Wu Li‐Zhu 
Published: January 2020

AbstractRadical formation is the initial step for conventional radical chemistry. Reported herein is a unified strategy to generate radicals in situ from aromatic β‐ketoesters by using a photocatalyst. Under visible‐light irradiation, a small amount of photocatalyst fac‐Ir(ppy)3 generates a transient α‐carbonyl radical and persistent ketyl radical in situ. In contrast to the well‐established approaches, neither stoichiometric external oxidant nor reductant is required for this reaction. The synthetic utility is demonstrated by pinacol coupling of ketyl radicals and benzannulation of α‐carbonyl radicals with alkynes to give a series of highly substituted 1‐naphthols in good to excellent yields. The readily available photocatalyst, mild reaction conditions, broad substrate scope, and high functional‐group tolerance make this reaction a useful synthetic tool.
Tunable Surface Wrinkling by a Bio‐Inspired Polyamine Anion Coacervation Process that Mediates the Assembly of Polyoxometalate Nanoclusters
Authors: Chilivery Rakesh , Begum Gousia , Chaitanya Vahinipathi , Rana Rohit Kumar 
Published: January 2020

AbstractA bio‐inspired method is used to render controlled wrinkling surface patterns on supramolecular architectures assembled from polyoxometalate (POM) clusters. It involves a polyamine‐multivalent anion interaction generating positively charged coacervates, which while dictating the assembly of POM into spherical structures further facilitate an interesting surface morphogenesis with wrinkling patterns. This spontaneous surface wrinkling depends on the type of multivalent anion and the pH. As the polyamine‐anion interaction becomes stronger, the wrinkles turn denser with lesser depth, which eventually undergoes post‐buckling to engender a complex surface pattern. Interestingly, the order of influence exerted by different anions on the morphology follows the Hofmeister series. Moreover, the mild synthesis conditions keep the functional POM units dispersed in the sphere with a structural transformability to their lacunary form.
Photoresponsive Propeller‐like Chiral AIE Copper(I) Clusters
Authors: Kong Yu‐Jin , Yan Zhi‐Ping , Li Si , Su Hui‐Fang , Li Kai , Zheng You‐Xuan , Zang Shuang‐Quan 
Published: January 2020

AbstractA pair of propeller‐like chiral trinuclear CuI clusters (R/S‐Cu3) with unique photoinduced fluorescence enhancement were prepared. R/S‐Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation‐induced emission (AIE) (αAIE=17.3). Mechanism studies showed that metal cluster‐centered (MCC) and triplet metal‐to‐ligand charge‐transfer (3MLCT) processes are the origin of the luminescence; the processes are regulated by a restriction of intramolecular motions mechanism in a different state. The chiral structure and AIE feature endow R/S‐Cu3 with remarkable circularly polarized luminescence (glum=2×10−2) in the aggregated state. It shows good capability for producing reactive oxygen species. This work enriches the kinds of atomically precise AIE clusters, gains insight into their luminescence mechanism, and offers the prospect of application in multifunctional materials.
Nickel‐Catalyzed Asymmetric Hydrogenation of 2‐Amidoacrylates
Authors: Hu Yawen , Chen Jianzhong , Li Bowen , Zhang Zhenfeng , Gridnev Ilya D. , Zhang Wanbin 
Published: January 2020

AbstractEarth‐abundant nickel, coordinated with a suitable chiral bisphosphine ligand, was found to be an efficient catalyst for the asymmetric hydrogenation of 2‐amidoacrylates, affording the chiral α‐amino acid esters in quantitative yields and excellent enantioselectivity (up to 96 %ee). The active catalyst component was studied by NMR and HRMS, which helped us to realize high catalytic efficiency on a gram scale with a low catalyst loading (S/C=2000). The hydrogenated products could be simply converted into chiral α‐amino acids, β‐amino alcohols, and their bioactive derivatives. Furthermore, the catalytic mechanism was investigated using deuterium‐labeling experiments and computational calculations.
Rheological improvement in performance of low‐rank coal–water slurries using novel cost‐effective additives
Authors: Amin Naila , Tahir Muhammad Suleman , Saleem Mehmood , Khan Zakir , Aslam Muhammad , Bazmi Aqeel Ahmed , Ghauri Moinuddin , Sagir Muhammad 
Published: January 2020

AbstractCoal–water slurry (CWS) has been targeted as a promising fuel and an alternative to fuel oil. CWS has numerous advantages of low and convenient transportation and high solid content. Pakistan is going through a severe energy crisis and among the top 10 countries facing energy crises reported by the United Nations. Besides, Pakistan has become the top seventh country in coal reserves (i.e., 185 billion tones) after the discovery of huge lignite coal reserves in Thar, Sind province. Previous studies investigated the use of additives to enhance CWS properties at a low shear rate and its utilization accordingly. Particularly, the present work studied the high range of shear rate to improve the properties of CWS for transportation and combustion purposes. This study on the improvement in performance of rheology properties of CWS is conducted to improve the properties by cost‐effective additives. The coal concentration varies from 20% to 60%, whereas runs were carried out with and without the cost‐effective additives. The results demonstrated that the coal slurry showed shear‐thinning property when viscosity was increased at high concentrations in the absence of additives. The addition of additive changed the rheological behavior from pseudoplastic to dilatant region. The presence of a high fraction of coal increased the apparent viscosity of CWS. The static stability test of all coal samples was performed using rod drop method at concentrations of 40% to 60%. The study found that stability was achieved earlier with a lower concentration of 40% as compared with higher concentrations of 50–60%. It is expected that this research would be helpful for the country facing adverse energy crises that badly affect the economy and other social aspects of human life.
Design of a run‐to‐run controller based on discrete sliding‐mode observer
Authors: Wang Haiyan , Pan Tianhong , Ding Shihong , Chen Shan 
Published: January 2020

AbstractIn this study, a run‐to‐run controller based on a discrete sliding‐mode observer (DSMO) is presented for photolithography manufacturing processes. A second‐order DSMO is introduced to estimate the process disturbances caused by tool aging and preventive maintenance. The proposed controller is constructed by applying DSMO estimation to the deadbeat control law and the stable region is discussed. Numerical simulations and an industrial case demonstrated the performance of the proposed algorithm. It is observed that the proposed controller has a superior performance over the exponentially weighted moving average (EWMA) and double EWMA (dEWMA) controller under the first‐order integrated moving average disturbance with shift or drift. This superiority is maintained when the system contains a certain plant‐model mismatch. Moreover, the tolerance of the proposed controller for metrology delay is better than that of the dEWMA controller.
Future projections and uncertainty assessment of precipitation extremes in the Korean peninsula from the CMIP5 ensemble
Authors: Lee Youngsaeng , Shin Younggwan , Boo Kyung‐On , Park Jeong‐Soo 
Published: January 2020

AbstractProjections of changes in extreme climate are sometimes predicted by multimodel ensemble methods that combine forecasts from individual simulation models using weighted averaging. One method to assign weight to each model is the Bayesian model averaging (BMA) in which posterior probability is used. For the cases of extreme climate, the generalized extreme value distribution (GEVD) is typically used. We applied the approach of GEV‐embedded BMA to a series of 35 years of the annual maximum daily precipitation data (both historical data and data gathered from simulation experiments for future periods) over the Korean peninsula as simulated by the models in the Coupled Model Intercomparison Project Phase 5 (CMIP5). Simulation data under two Representative Concentration Pathway (RCP) scenarios, namely RCP4.5 and RCP8.5, were used. Observed data and 17 CMIP5 models for 12 gird cells in Korea have been examined to predict future changes in precipitation extremes. A simple regional frequency analysis of pooling observations from three stations in each cell was employed to reduce the estimation variance and local fluctuations. A bias correction technique using the regression‐type transfer function was applied to these simulation data. Return levels spanning over 20 and 50 years, as well as the return periods relative to the reference years (1971–2005), were estimated for two future periods, namely Period 1 (2021–2050) and Period 2 (2066–2095). From these analyses, relative increase observed in the spatially averaged 20‐year (50‐year) return level was approximately 23% (16%) and 45% (36%) in the RCP4.5 and RCP8.5 experiments, respectively, by the end of the 21st century. We concluded that extreme rainfalls will likely occur two times and four times more frequently in the RCP4.5 and RCP8.5 scenarios, respectively, as compared to in the reference years by the end of the 21st century.
Autism Heterogeneity in a Densely Sampled U.S. Population: Results From the First 1,000 Participants in the RI‐CART Study
Authors: McCormick Carolyn E. B. , Kavanaugh Brian C. , Sipsock Danielle , Righi Giulia , Oberman Lindsay M. , Moreno De Luca Daniel , Gamsiz Uzun Ece D. , Best Carrie R. , Jerskey Beth A. , Quinn Joanne G. , Jewel Susan B. , Wu Pei‐Chi , McLean Rebecca L. , Levine Todd P. , Tokadjian Hasmik , Perkins Kayla A. , Clarke Elaine B. , Dunn Brittany , Gerber Alan H. , Tenenbaum Elena J. , Anders Thomas F. ,   Rhode Island Consortium for Autism Research and Treatment (RI‐CART), Sheinkopf Stephen J. , Morrow Eric M. 
Published: January 2020

The objective of this study was to establish a large, densely sampled, U.S. population‐based cohort of people with autism spectrum disorder (ASD). The Rhode Island Consortium for Autism Research and Treatment (RI‐CART) represents a unique public‐private‐academic collaboration involving all major points of service for families in Rhode Island affected by ASD. Diagnosis was based on direct behavioral observation via the Autism Diagnostic Observation Schedule, Second Edition. For the first 1,000 participants, ages ranged from 21 months to 64 years. Using Geographic Information System and published prevalence rates, the overall cohort is estimated to represent between 20% and 49% of pediatric age persons in Rhode Island with ASD, with demographics representative of U.S. Census. We observed a high rate of co‐occurring medical and psychiatric conditions in affected individuals. Among the most prominent findings of immediate clinical importance, we found that females received a first diagnosis of ASD at a later age than males, potentially due to more advanced language abilities in females with ASD. In summary, this is the first analysis of a large, population‐based U.S. cohort with ASD. Given the depth of sampling, the RI‐CART study reflects an important new resource for studying ASD in a representative U.S. population. Psychiatric and medical comorbidities in ASD constitute a substantial burden and warrant adequate attention as part of overall treatment. Our study also suggests that new strategies for earlier diagnosis of ASD in females may be warranted. Autism Res 2020, 13: 474–488. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryThe Rhode Island Consortium for Autism Research and Treatment (RI‐CART) represents a unique public‐private‐academic collaboration involving all major points of service for families in Rhode Island affected by autism spectrum disorder (ASD). In this article, we provide results from the first 1,000 participants, estimated to represent >20% of affected families in the state. Importantly, we find a later age at first diagnosis of ASD in females, which potentially calls attention to the need for improved early diagnosis in girls. Also, we report a high rate of co‐occurring medical and psychiatric conditions in affected individuals.
Purification and characterization of chitinase from Paenibacillus sp.
Authors: Du Jinghe , Duan Shan , Miao Jianyin , Zhai Miaomiao , Cao Yong 
Published: January 2020

AbstractThe chitinase‐producing bacteria Paenibacillus sp. was isolated from soil samples. The chitinase was purified successively by ammonia sulfate fractional precipitation followed by chromatography on DEAE 52‐cellulose column and then on Sephadex G‐75 column. The chitinase has a molecular weight of ca. 30 kDa as measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE) electrophoresis. Its optimum pH is 4.5, and its optimum temperature is 50 °C with colloidal chitin as a substrate. The enzyme is stable below 45 °C and in pH ranges between 4.5 and 5.5. It is activated by glucosamine, glucose, N‐acetylglucosamine, and metal ions including Ca2+, Fe2+, Fe3+, and Ni2+. It is inhibited by SDS, H2O2, ascorbic acid, Cu2+, Mg2+, Ba2+, Sn2+, Cr3+, and K+. With colloidal chitin as substrate, the Km and the Vmax of the chitinase are 4.28 mg/mL and 14.29 μg/(Min·mL), respectively, whereas the end products of the enzymatic hydrolysis are 14.33% monomer and 85.67% dimer of N‐acetylglucosamine. The viscosity of carboxymethyl chitin decreased rapidly at the initial stages when subjected to chitinase hydrolysis, which indicates that the chitinase acts in an endosplitting pattern.
Generalized parametric cure models for relative survival
Authors: Jakobsen Lasse Hjort , Bøgsted Martin , Clements Mark 
Published: January 2020

AbstractCure models are used in time‐to‐event analysis when not all individuals are expected to experience the event of interest, or when the survival of the considered individuals reaches the same level as the general population. These scenarios correspond to a plateau in the survival and relative survival function, respectively. The main parameters of interest in cure models are the proportion of individuals who are cured, termed the cure proportion, and the survival function of the uncured individuals. Although numerous cure models have been proposed in the statistical literature, there is no consensus on how to formulate these. We introduce a general parametric formulation of mixture cure models and a new class of cure models, termed latent cure models, together with a general estimation framework and software, which enable fitting of a wide range of different models. Through simulations, we assess the statistical properties of the models with respect to the cure proportion and the survival of the uncured individuals. Finally, we illustrate the models using survival data on colon cancer, which typically display a plateau in the relative survival. As demonstrated in the simulations, mixture cure models which are not guaranteed to be constant after a finite time point, tend to produce accurate estimates of the cure proportion and the survival of the uncured. However, these models are very unstable in certain cases due to identifiability issues, whereas LC models generally provide stable results at the price of more biased estimates.
Smoothed empirical likelihood inference for ROC curve in the presence of missing biomarker values
Authors: Cheng Weili , Tang Niansheng 
Published: January 2020

AbstractThis paper considers statistical inference for the receiver operating characteristic (ROC) curve in the presence of missing biomarker values by utilizing estimating equations (EEs) together with smoothed empirical likelihood (SEL). Three approaches are developed to estimate ROC curve and construct its SEL‐based confidence intervals based on the kernel‐assisted EE imputation, multiple imputation, and hybrid imputation combining the inverse probability weighted imputation and multiple imputation. Under some regularity conditions, we show asymptotic properties of the proposed maximum SEL estimators for ROC curve. Simulation studies are conducted to investigate the performance of the proposed SEL approaches. An example is illustrated by the proposed methodologies. Empirical results show that the hybrid imputation method behaves better than the kernel‐assisted and multiple imputation methods, and the proposed three SEL methods outperform existing nonparametric method.