An assessment of the causes of the errors in the 2015 UK General Election opinion polls

The opinion polls undertaken prior to the 2015 UK General Election under-estimated the Conservative lead over Labour by an average of 7 percentage points. This collective failure led politicians and commentators to question the validity and utility of political polling and raised concerns regarding a broader public loss of confidence in survey research. In this paper, we assess the likely causes of the 2015 polling errors. We begin by setting out a formal account of the statistical methodology and assumptions required for valid estimation of party vote shares using quota sampling. We then describe the current approach of polling organisations for estimating sampling variability and suggest a new method based on bootstrap re-sampling. Next, we use poll micro-data to assess the plausibility of different explanations of the polling errors. Our conclusion is that the primary cause of the polling errors in 2015 was unrepresentative sampling

Highly Stereoselective Hydrocarbation of Terminal Alkynes via Pt-Catalyzed Hydrosilylation/Pd-Catalyzed Cross-Coupling Reactions

The formal addition of an aryl-H or alkenyl-H bond across a terminal alkyne has been accomplished by the combination of platinum-catalyzed hydrosilylation followed by palladium-catalyzed cross-coupling. The use of the t-Bu3P−Pt(DVDS) catalyst in combination with tetramethyldisiloxane gave excellent regio- and stereoselectivity with a number of alkyne substrates. Subsequent, fluoride-promoted cross-coupling proceeded in high yield and stereospecificity for a variety of aryl halides

Highly Stereoselective Hydrocarbation of Terminal Alkynes via Pt-Catalyzed Hydrosilylation/Pd-Catalyzed Cross-Coupling Reactions

The formal addition of an aryl-H or alkenyl-H bond across a terminal alkyne has been accomplished by the combination of platinum-catalyzed hydrosilylation followed by palladium-catalyzed cross-coupling. The use of the t-Bu3P−Pt(DVDS) catalyst in combination with tetramethyldisiloxane gave excellent regio- and stereoselectivity with a number of alkyne substrates. Subsequent, fluoride-promoted cross-coupling proceeded in high yield and stereospecificity for a variety of aryl halides

Table_1_Publishing in English or Chinese: a qualitative analysis of Chinese researchers’ academic language choice.DOCX

Non-native language scholars often struggle to choose between English and their native language in scholarly publishing. This study aims to identify the mechanism by which journal attributes influence language choice by investigating the perspectives of 18 Chinese scholars through semi-structured interviews. Drawing on grounded theory, this study develops a model for how journal attributes influence researchers’ language preferences. We find that journal attributes influence researchers’ perceived value which, in turn, affects their particular language choice, with contextual factors playing a moderating role. By examining the motivations underlying Chinese scholars’ language choice, this study provides a critical understanding of the factors shaping their decision-making processes. These findings have significant implications for Chinese scholars, policymakers, and journal operators, shedding light on the issue of discrimination in academic publishing. Addressing these concerns is crucial for fostering a fair and inclusive academic environment.</p

Ir(III)-Catalyzed Oxidative Annulation of Phenylglyoxylic Acids with Benzo[<i>b</i>]thiophenes

An Ir­(III)-catalyzed oxidative annulation of phenylglyoxylic acids with benzo­[b]­thiophenes for the construction of benzo­thieno­[3,2-c]­[2]­benzo­pyranones in one step is disclosed. Three C–H cleavages and C–C/C–O bond formations are involved in this reaction. This protocol features a relatively broad substrate scope, good functional group tolerance, good regioselectivities, mild reaction conditions, and scale-up synthesis

Effect of Chain Conformation on the Single-Molecule Melting Force in Polymer Single Crystals: Steered Molecular Dynamics Simulations Study

Understanding the relationship between polymer chain conformation as well as the chain composition within the single crystal and the mechanical properties of the corresponding single polymer chain will facilitate the rational design of high performance polymer materials. Here three model systems of polymer single crystals, namely poly­(ethylene oxide) (PEO), polyethylene (PE), and nylon-66 (PA66) have been chosen to study the effects of chain conformation, helical (PEO) versus planar zigzag conformation (PE, PA66), and chain composition (PE versus PA66) on the mechanical properties of a single polymer chain. To do that, steered molecular dynamics simulations were performed on those polymer single crystals by pulling individual polymer chains out of the crystals. Our results show that the patterns of force–extension curve as well as the chain moving mode are closely related to the conformation of the polymer chain in the single crystal. In addition, hydrogen bonds can enhance greatly the force required to stretch the polymer chain out of the single crystal. The dynamic breaking and reformation of multivalent hydrogen bonds have been observed for the first time in PA66 at the single molecule level

Oxidative CO₂ Reforming of Methane in La_0.6Sr_0.4Co_0.8Ga_0.2O_3‑δ (LSCG) Hollow Fiber Membrane Reactor

CO₂ utilization in catalytic membrane reactors for syngas production is an environmentally benign solution to counter the escalating global CO₂ concerns. In this study, integration of a La_0.6Sr_0.4Co_0.8Ga_0.2O_3‑δ (LSCG) hollow fiber membrane reactor with Ni/LaAlO₃–Al₂O₃ catalyst for the oxidative CO₂ reforming of methane (OCRM) reaction was successfully tested for 160 h of reaction. High CH₄ and CO₂ conversions of ca. 94% and 73% were obtained with O₂ flux ca. 1 mL·min^–1·cm^–2 at 725 °C for the 160-h stability test. Surface temperature programmed desorption studies of the membrane were conducted with H₂, CO, and CO₂ as probe gases to facilitate understanding on the effect of H₂ and CO product gases as well as CO₂ reactant gases on the membrane surface. Scanning electron microscopy–energy dispersive X-ray (SEM-EDX), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) analysis of the postreacted membrane after 160-h stability tests suggests Sr-enriched phases with the presence of adsorbed carbonate and hydrogenated carbon. This shows the subsequent reactant spillover on the membrane surface from the catalyst bed took place due to the reaction occurring on the catalyst. However, XRD analysis of the bulk structure does not show any phase impurities, thus confirming the structural integrity of the LSCG hollow fiber membrane

Crystallization-Induced Fluid Flow in Polymer Melts Undergoing Solidification

Crystallization-Induced Fluid Flow in Polymer Melts Undergoing Solidificatio

P(<i>i</i>-PrNCH₂CH₂)₃N: An Effective Lewis Base Promoter for the Allylation of Aromatic Aldehydes with Allyltrimethylsilane

P(i-PrNCH2CH2)3N:  An Effective Lewis Base Promoter for the Allylation of Aromatic Aldehydes with Allyltrimethylsilan