bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Synthesis of Ipsenol and Ipsdienol: A Review (1968–2020)
Authors: Marco‐Contelles José 
Published: February 2021

AbstractHerein I present a review on the synthesis of ipsenol and ipsdienol, two aggregation pheromones of bark beetles, isolated from different species of genus Ips, and serious pests of conifer forests. I have covered the literature for around fifty years, since 1968 to 2020. This account has been divided in different sections and sub‐sections, including a general and brief outlook on their isolation, structure and biological activity, to continue with the reported synthesis of racemic ipsenol and ipsdienol, including my own contribution to topic, and the presentation of reports describing the synthesis of enantiomerically pure ipsenol and ipsdienol. Particular attention has been devoted to identify and highlight racemic or enantiomerically pure “isoprene synthons”, and isoprenylation methods employed in the synthesis of ipsenol and ipsdienol, of general interest for related terpene derivatives synthesis.
Plasmon and Plexciton Driven Interfacial Catalytic Reactions
Authors: Yang Rui , Cheng Yuqing , Song Yujun , Belotelov Vladimir I. , Sun Mengtao 
Published: February 2021

AbstractIn this review, we focus on the summary of catalytic reaction driven by surface plasmons and plexciton, where the plexciton is the interaction between plasmon and exciton. We first review the reduction and oxidation reactions driven by plasmons, and analyze the role of plasmons in the two reactions. We then summarize the recent research on the surface catalytic reactions driven by plasmon‐exciton coupling and discuss the promotion effect of coupling interaction in oxidation reaction and reduction reaction. The coupling effect of plasmons and excitons can successfully improve the efficiency of catalytic reactions. Finally, this paper demonstrates the research progress in the electrooptical synergic plasmon‐exciton co‐driven surface catalytic reactions.
Curcumin suppresses the stemness of non‐small cell lung cancer cells via promoting the nuclear‐cytoplasm translocation of TAZ
Authors: Zheng Yuzhen , Yang Xingping , Tan Jian , Tian Renjiang , Shen Piao , Cai Weijie , Liao Hongying 
Published: February 2021

AbstractCurcumin has been shown to suppress the progression of lung cancer, however, the underlying mechanisms are largely unknown. Here, we aimed to investigate the effects of curcumin on the stemness of non‐small cell lung cancer (NSCLC) cells. We found that curcumin reduced the sphere formation ability at the concentrations without affecting the cell viability of NSCLC cells and normal pulmonary epithelial cells, which is evident by the decrease of sphere size and number. In addition, curcumin decreased ALDH activity and the expression of stemness markers (CD133, EpCAM, Oct4). RNA sequencing analysis revealed that the Hippo pathway was mostly enriched in cells with curcumin treatment. Indeed, the expression of cancer stem cell markers was significantly decreased by curcumin treatment by analyzing the RNA sequencing data. Gene set enrichment analysis (GSEA) showed that curcumin negatively regulated the cancer stem cell function and positively modulated cancer stem cell differentiation ability. Furthermore, curcumin enhanced the cisplatin sensitivity of NSCLC cells. Mechanistically, it was found that curcumin promoted the nuclear‐cytoplasm translocation of TAZ, but not YAP, the critical effectors of Hippo pathway. In addition, curcumin destabilzed TAZ protein stability and promoted TAZ protein degradation in lung cancer cells, which is dependent on the proteasome degradation system, not by autophagy lysosome degradation system. Overexpression of TAZ rescued the inhibition of curcumin on the stemness of lung cancer cells. Thus, our results suggest that curcumin can attenuate the stemness of lung cancer cells through promoting TAZ protein degradation and thus activating Hippo pathway.
Visualizing riparian ecotone fragmentation in urbanizing watersheds: A case study of upper Hickory Creek, north‐Central Texas
Authors: Yesildirek Monica Veale , Hudak Paul F. 
Published: February 2021

AbstractMany pollution sources and heavy runoff often plague urbanizing watersheds. Riparian ecotones can filter pollutants and attenuate runoff; however, changing land cover tends to diminish this buffering capacity. Visualizing riparian ecotone fragmentation at the watershed scale can help prioritize management efforts. A geographic information systems approach was developed to illustrate land cover and soil properties affecting buffering potential along riparian corridors. An application to the Hickory Creek watershed in north‐central Texas shows significant riparian ecotone fragmentation, suggesting high‐priority areas for preservation and restoration.
An introduction to persistent homology for time series
Authors: Ravishanker Nalini , Chen Renjie 
Published: February 2021

AbstractTopological data analysis (TDA) uses information from topological structures in complex data for statistical analysis and learning. This paper discusses persistent homology, a part of computational (algorithmic) topology that converts data into simplicial complexes and elicits information about the persistence of homology classes in the data. It computes and outputs the birth and death of such topologies via a persistence diagram. Data inputs for persistent homology are usually represented as point clouds or as functions, while the outputs depend on the nature of the analysis and commonly consist of either a persistence diagram, or persistence landscapes. This paper gives an introductory level tutorial on computing these summaries for time series using R, followed by an overview on using these approaches for time series classification and clustering.This article is categorized under:
Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification
Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
Applications of Computational Statistics > Computational Mathematics
A review of second‐order blind identification methods
Authors: Pan Yan , Matilainen Markus , Taskinen Sara , Nordhausen Klaus 
Published: February 2021

AbstractSecond‐order source separation (SOS) is a data analysis tool which can be used for revealing hidden structures in multivariate time series data or as a tool for dimension reduction. Such methods are nowadays increasingly important as more and more high‐dimensional multivariate time series data are measured in numerous fields of applied science. Dimension reduction is crucial, as modeling such high‐dimensional data with multivariate time series models is often impractical as the number of parameters describing dependencies between the component time series is usually too high. SOS methods have their roots in the signal processing literature, where they were first used to separate source signals from an observed signal mixture. The SOS model assumes that the observed time series (signals) is a linear mixture of latent time series (sources) with uncorrelated components. The methods make use of the second‐order statistics—hence the name “second‐order source separation.” In this review, we discuss the classical SOS methods and their extensions to more complex settings. An example illustrates how SOS can be performed.This article is categorized under:
Statistical Models > Time Series Models
Statistical and Graphical Methods of Data Analysis > Dimension Reduction
Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
Can colored object enrichment reduce the escape behavior of captive freshwater turtles?
Authors: Bannister Callum C. , Thomson Angus J. C. , Cuculescu‐Santana Mirela 
Published: February 2021

AbstractThe effect of environmental enrichment on the behavior and welfare in captivity of reptiles and of freshwater turtles in particular, which are popular aquarium and pet species, is very little studied compared to other taxa. We carried out a small scale case‐study on the effect of colored object enrichment, with and without fish scent, on the behavior of a group of 15 cooters (Pseudemys sp.) and sliders (Trachemys scripta ssp.) on display at a public aquarium. The new enrichment aimed to reduce the escape behavior (interaction with transparent boundaries) and increase exploration and random swimming. We used simultaneous recording of behavior at whole group level and for focal individually‐marked turtles. The escape behavior decreased on days with new enrichment before feeding at whole group level and for the focal turtles overall, in spite of the relatively low interest in the colored objects. Fish‐scented objects attracted significantly more interest. Random swimming, enrichment focus, aggression and submission increased significantly, and basking decreased significantly at whole group level before feeding, with smaller differences after feeding. There were large differences between individual turtles with respect to activity budgets and changes in behavior on days with new enrichment, with both increases and decreases seen in escape behavior, aggression, and levels of activity. Our outcomes suggested that introducing new colored objects with food scent may be beneficial for reducing escape behavior in captive freshwater turtles. However, careful monitoring of effects at individual level and much larger scale investigations, including postenrichment periods, are needed.
Effect of enclosure expansion on the activity budgets of eastern black‐and‐white colobus monkeys, Colobus guereza
Authors: Robbins R. L. , Sheridan J. 
Published: February 2021

AbstractBehavior is one of the most observable and informative indicators of animal welfare. This study used behavioral observation methodologies to evaluate the impact of an enclosure expansion on the activity budgets of a group of three eastern black‐and‐white colobus monkeys, Colobus guereza, housed at the Adelaide Zoo in South Australia. Instantaneous scan sampling methods were used to record the monkeys' behavior before and after they were given access to new aerial walkways at 2‐min intervals between 8:30 a.m. and 4:30 p.m., over a total of 109 h (66 baseline hours, 43 post‐expansion hours). Broad state behaviors (e.g., social, moving, resting, interacting, and feeding) were recorded and were used to generate activity budgets. Locomotion, feeding, and social behaviors increased following the addition of the aerial walkways, along with an overall increase in activity, attributed to the larger area and increased complexity of the environment. Results indicate that the addition of aerial walkways was effective for increasing the behavioral repertoire in colobus monkeys, aligning activity budgets more closely with their wild counterparts, and increasing active and affiliative behaviors.
Growth, calcification, and photobiology of the threatened coral Acropora cervicornis in natural versus artificial light
Authors: Slagel Sebastian , Lohr Kathryn , O'Neil Keri , Patterson Joshua 
Published: February 2021

AbstractLand‐based coral culture is of increasing interest for conservation and educational display. Shallow water corals generate most of their energy from photosynthesis, and light is a critical abiotic factor in their husbandry. We compared growth, calcification, and photobiology in the coral Acropora cervicornis between natural and artificial (light‐emitting diode; LED) light to better understand the impact of light source on coral performance. One tank of a greenhouse recirculating system at The Florida Aquarium's Center for Conservation was used to culture replicate coral colonies. Half of the tank and corals were covered to block sunlight and illuminated with a commercial reef aquarium LED fixture, while the other half was exposed to natural sunlight. Treatments were matched in terms of maximum photosynthetically active radiation and spectral measurements characterized both light regimes. Coral growth and calcification were tracked over a period of 19 weeks by repeated measurements of total linear extension (TLE) and buoyant weight. For the first 5 weeks, photosynthetic yield was measured weekly using a pulse‐amplitude‐modulated fluorometer. Calcification was significantly higher under LED lighting relative to natural light, but TLE did not differ. Photobiology data suggest that corals in both treatments were acclimated to the same light level, but photosynthetic efficiency was ultimately greater in the natural light treatment. More consistent light delivery and different spectral composition under LED treatment conditions may explain the incongruity between calcification and photosynthetic efficiency. This experiment informs husbandry of shallow‐water scleractinian corals maintained in both natural sunlight and enclosed structures.
Infrared Problem vs Gauge Choice: Scattering of Classical Dirac Field
Authors: Herdegen Andrzej 
Published: February 2021

AbstractWe consider the Dirac equation for the classical spinor field placed in an external, time-dependent electromagnetic field of the form typical for scattering settings: $$F=F^\mathrm{ret}+F^\mathrm{in}=F^\mathrm{adv}+F^\mathrm{out}$$

F
=

F
ret

+

F
in

=

F
adv

+

F
out

, where the current producing $$F^{\mathrm{ret}/\mathrm{adv}}$$

F

ret
/
adv

has past and future asymptotes homogeneous of degree $$-3$$

-
3

, and the free fields $$F^{\mathrm{in}/\mathrm{out}}$$

F

in
/
out

are radiation fields produced by currents with similar asymptotic behavior. We show the existence of the electromagnetic gauges in which the particle has ‘in’ and ‘out’ asymptotic states approaching free field states, with no long-time corrections of the free dynamics. Using a special Cauchy foliation of the spacetime, we show in this context the existence and asymptotic completeness of the wave operators. Moreover, we define a special ‘evolution picture’ in which the free evolution operator has well-defined limits for $$t\rightarrow \pm \infty $$

t
→
±
∞

; thus the scattering wave operators do not need the free evolution counteraction.
100 kHz satellite laser ranging demonstration at Matera Laser Ranging Observatory
Authors: Dequal Daniele , Agnesi Costantino , Sarrocco David , Calderaro Luca , Santamaria Amato Luigi , Siciliani de Cumis Mario , Vallone Giuseppe , Villoresi Paolo , Luceri Vincenza , Bianco Giuseppe 
Published: February 2021

AbstractThe new challenges related to the monitoring of Earth’s shape and motion have led the global geodetic observing system to set more stringent requirements on the precision and stability of the terrestrial reference frame (TRF). The achievement of this ambitious goal depends on the improvement of space geodesy techniques, satellite laser ranging (SLR) in particular, being the main instrument for TRF realization. In this work, we study the potential of very high repetition rate SLR by performing a data acquisition campaign with an Ekspla “Atlantic 60” 100 kHz repetition rate laser at the Matera Laser Ranging Observatory (MLRO). This system constitutes an increase of two orders of magnitude in repetition rate with respect to the current SLR stations, while maintaining a good single-shot timing performance. The system has been active for 4 consecutive nights, consistently tracking several low Earth orbit satellites as well as LAGEOS 1 and 2. The results have shown a single-shot time jitter close to other stations, but with unprecedented statistics for $$\approx 10$$

≈
10

ps single-shot precision. The analysis of the residuals of LAGEOS satellites allowed us to identify multiple peaks, due to the retroflection from different corner cubes. This opens up the possibility of attitude determination of retroreflector arrays, as well as a new method for spin rate measurement.
How Naunyn-Schmiedeberg’s Archives of Pharmacology deals with fraudulent papers from paper mills
Authors: Seifert Roland 
Published: February 2021

AbstractFraudulent papers from paper mills are a serious threat to the entire scientific community. Naunyn-Schmiedeberg’s Archives of Pharmacology has become the target of a massive attack of fraudulent papers originating from paper mills. This editorial highlights 20 important features we observed with paper mills and explains how the journal is responding to this serious threat to restore the integrity of science. Hopefully, this editorial is also helpful for editors of other scientific journals.
CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation
Authors: Veit-Haibach Patrick , Huellner Martin W. , Banyai Martin , Mafeld Sebastian , Heverhagen Johannes , Strobel Klaus , Sah Bert-Ram 
Published: February 2021

Abstract
Objectives
The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation.

Methods
Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests.

Results
The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively).

Conclusions
CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease.

Key Points
• CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients.
• This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.
Recurrent transitions to Little Ice Age-like climatic regimes over the Holocene
Authors: Helama Samuli , Stoffel Markus , Hall Richard J. , Jones Phil D. , Arppe Laura , Matskovsky Vladimir V. , Timonen Mauri , Nöjd Pekka , Mielikäinen Kari , Oinonen Markku 
Published: February 2021

AbstractHolocene climate variability is punctuated by episodic climatic events such as the Little Ice Age (LIA) predating the industrial-era warming. Their dating and forcing mechanisms have however remained controversial. Even more crucially, it is uncertain whether earlier events represent climatic regimes similar to the LIA. Here we produce and analyse a new 7500-year long palaeoclimate record tailored to detect LIA-like climatic regimes from northern European tree-ring data. In addition to the actual LIA, we identify LIA-like ca. 100–800 year periods with cold temperatures combined with clear sky conditions from 540 CE, 1670 BCE, 3240 BCE and 5450 BCE onwards, these LIA-like regimes covering 20% of the study period. Consistent with climate modelling, the LIA-like regimes originate from a coupled atmosphere–ocean–sea ice North Atlantic-Arctic system and were amplified by volcanic activity (multiple eruptions closely spaced in time), tree-ring evidence pointing to similarly enhanced LIA-like regimes starting after the eruptions recorded in 1627 BCE, 536/540 CE and 1809/1815 CE. Conversely, the ongoing decline in Arctic sea-ice extent is mirrored in our data which shows reversal of the LIA-like conditions since the late nineteenth century, our record also correlating highly with the instrumentally recorded Northern Hemisphere and global temperatures over the same period. Our results bridge the gaps between low- and high-resolution, precisely dated proxies and demonstrate the efficacy of slow and fast components of the climate system to generate LIA-like climate regimes.
Characteristics of intracerebral haemorrhage associated with COVID-19: a systematic review and pooled analysis of individual patient and aggregate data
Authors: Beyrouti R. , Best J. G. , Chandratheva A. , Perry R. J. , Werring D. J. 
Published: February 2021

Abstract
Background and purpose
There are very few studies of the characteristics and causes of ICH in COVID-19, yet such data are essential to guide clinicians in clinical management, including challenging anticoagulation decisions. We aimed to describe the characteristics of spontaneous symptomatic intracerebral haemorrhage (ICH) associated with COVID-19.

Methods
We systematically searched PubMed, Embase and the Cochrane Central Database for data from patients with SARS-CoV-2 detected prior to or within 7 days after symptomatic ICH. We did a pooled analysis of individual patient data, then combined data from this pooled analysis with aggregate-level data.

Results
We included data from 139 patients (98 with individual data and 41 with aggregate-level data). In our pooled individual data analysis, the median age (IQR) was 60 (53–67) years and 64% (95% CI 54–73.7%) were male; 79% (95% CI 70.0–86.9%) had critically severe COVID-19. The pooled prevalence of lobar ICH was 67% (95% CI 56.3–76.0%), and of multifocal ICH was 36% (95% CI 26.4–47.0%). 71% (95% CI 61.0–80.4%) of patients were treated with anticoagulation (58% (95% CI 48–67.8%) therapeutic). The median NIHSS was 28 (IQR 15–28); mortality was 54% (95% CI 43.7–64.2%). Our combined analysis of individual and aggregate data showed similar findings. The pooled incidence of ICH across 12 cohort studies of inpatients with COVID-19 (n = 63,390) was 0.38% (95% CI 0.22–0.58%).

Conclusions
Our data suggest that ICH associated with COVID-19 has different characteristics compared to ICH not associated with COVID-19, including frequent lobar location and multifocality, a high rate of anticoagulation, and high mortality. These observations suggest different underlying mechanisms of ICH in COVID-19 with potential implications for clinical treatment and trials.