bluuebunny/crossref_metadata_2025 huggingface dataset:
Diel variations in cell division and biomass production of Emiliania huxleyi—Consequences for the calculation of physiological cell parameters
Authors: Kottmeier Dorothee M. , Terbrüggen Anja , Wolf‐Gladrow Dieter A. , Thoms Silke
Published: March 2020

Cell division of the coccolithophore Emiliania huxleyi and other phytoplankton typically becomes entrained to diel light/dark cycles under laboratory conditions, with division occurring primarily during dark phases and production occurring during light phases. Under these conditions, increases in cell and biomass concentrations deviate from exponential functions on time scales < 24 h. These deviations lead to significant diel variations in common measurements of phytoplankton physiology such as cellular quotas of particulate organic and inorganic carbon (POC, PIC) and their production rates. Being time‐dependent, only the temporal mean of the various values during the day are comparable between experiments. Deviations from exponential growth furthermore imply that increases in cell and biomass concentrations cannot be expressed by the daily growth rate
μ24 h (typically determined from daily increments in cell concentrations). Consequently, conventional calculations of production as the product of a cellular quota (e.g., POC quota) and
μ24 h are mathematically incorrect. To account for this, we here describe short‐term changes in cell and biomass concentrations of fast‐dividing, dilute‐batch cultures of E. huxleyi grown under a diel light/dark cycle using linear regression. Based on the derived models, we present calculations for daily means of cellular quotas and production rates. Conventional (time‐specific) measurements of cellular quotas and production differ from daily means by up to 65% in our example and, under some circumstances, cause false “effects” of treatments. Intending to reduce errors in ecophysiological studies, we recommend determining daily means—mathematically or by adjusting the experimental setup or sampling times appropriately.
Synthesis of Polyethylene‐Grafted Phosphite Antioxidant and Its Antioxidant Behavior in Polypropylene
Authors: Zhang Yin , Li Huayi , Luo Zhi , Li Mengru , Liu Tingting , Liu Weiwei , Li Qian , Hu Youliang
Published: March 2020

A novel macromolecular auxiliary antioxidant with polyethylene (PE) as polymer skeleton and phosphites as side groups is prepared based on commercial ethylene‐vinyl acetate (EVA) copolymers and its potential as polyolefin stabilizers is studied in depth. The synthesis approach of this PE‐grafted antioxidant consists of a typical EVA hydrolysis reaction and a two‐step nucleophilic substitution reaction of PCl3, 2,4‐di‐tert‐butylphenol, and the hydrolysis product. Results of the thermogravimetric analysis show that the macromolecular structures endow the as‐synthesized antioxidant with much better thermal stability than that of the commercial antioxidant 168. In addition, antioxidant behaviors of the PE‐grafted antioxidants in polypropylene (PP) matrix are investigated in detail through characterization of the melt flow index of multiple‐extruded stabilized PP as well as the short‐term oxidation induction time test and the long‐term thermo‐oxidative aging test. Results show that even with extremely low content of the effective antioxidant groups, the as‐synthesized macromolecular antioxidant still has excellent antioxygenic properties.
Glycopolymer Code: Programming Synthetic Macromolecules for Biological Targeting
Authors: Yilmaz Gokhan , Becer Caglar Remzi
Published: March 2020

Targeting in a cellular level is still one of the major challenges in biomedical treatments. However, new synthetic and analytical techniques now allow the development of precisely prepared macromolecules. Thus, glycopolymer chains are reported to be prepared with controlled length, monomer sequences, as well as chain‐folded structures. A high level of complexity in synthetic macromolecules also allows increased selectivity in targeting, which is a key factor in biomedical applications.
Plasma Short‐Chain Fatty Acids in Patients With Parkinson's Disease
Authors: Shin Chaewon , Lim Yunsook , Lim Hyewon , Ahn Tae‐Beom
Published: March 2020

Background

Short‐chain fatty acids are exclusively produced by gut microbiota and are reduced in feces of patients with Parkinson's disease (PD). The objective of this study was to conduct a case–control study on peripheral concentration of short‐chain fatty acids based on evidence of pathologic changes in the blood–brain barrier in PD and the possible role of short‐chain fatty acids in blood–brain barrier permeability.

Methods

The plasma short‐chain fatty acid concentration was measured in 38 PD and 33 normal controls using gas chromatography. The clinical characteristics of patients with PD and controls were evaluated, and dietary information was obtained using a food frequency questionnaire. Short‐chain fatty acid concentrations were further compared after adjusting for age, sex, and significant food frequency questionnaire items.

Results

The concentrations of acetate, propionate, and butyrate did not differ between patients with PD and controls in unadjusted comparison. Dietary intakes of fibers, carbohydrates, lipids (total and fatty acids), and proteins did not differ between groups. After correction of covariates, acetic acid concentration was higher in patients with PD than in controls (116.47 ± 16.83 vs 108.20 ± 18.37 μmol/L; P = 0.010). In correlation analyses, acetic acid concentration was positively correlated (R = 0.374, P = 0.021) with age, propionic acid concentration was negatively correlated with UPDRS part III score (R = −0.376, P = 0.020) and use of entacapone (R = −0.325, P = 0.047), and butyric acid concentration was correlated with monoamine oxidase inhibitor use (R = 0.382, P = 0.018) and anticholinergic use (R = −0.385, P = 0.024).

Conclusions

Plasma short‐chain fatty acids were paradoxically increased in PD and were associated with disease severity and antiparkinsonian medications. Further studies are warranted to elucidate the relationships of gut dysbiosis and inflammation with plasma short‐chain fatty acids. © 2020 International Parkinson and Movement Disorder Society
A preliminary computational outputs versus experimental results: Application of sTRAP, a biophysical tool for the analysis of SNPs of transcription factor‐binding sites
Authors: Moradifard Shirin , Saghiri Reza , Ehsani Parastoo , Mirkhani Fatemeh , Ebrahimi‐Rad Mina
Published: March 2020

Background

In the human genome, the transcription factors (TFs) and transcription factor‐binding sites (TFBSs) network has a great regulatory function in the biological pathways. Such crosstalk might be affected by the single‐nucleotide polymorphisms (SNPs), which could create or disrupt a TFBS, leading to either a disease or a phenotypic defect. Many computational resources have been introduced to predict the TFs binding variations due to SNPs inside TFBSs, sTRAP being one of them.

Methods

A literature review was performed and the experimental data for 18 TFBSs located in 12 genes was provided. The sequences of TFBS motifs were extracted using two different strategies; in the size similar with synthetic target sites used in the experimental techniques, and with 60 bp upstream and downstream of the SNPs. The sTRAP (http://trap.molgen.mpg.de/cgi-bin/trap_two_seq_form.cgi) was applied to compute the binding affinity scores of their cognate TFs in the context of reference and mutant sequences of TFBSs. The alternative bioinformatics model used in this study was regulatory analysis of variation in enhancers (RAVEN; http://www.cisreg.ca/cgi-bin/RAVEN/a). The bioinformatics outputs of our study were compared with experimental data, electrophoretic mobility shift assay (EMSA).

Results

In 6 out of 18 TFBSs in the following genes COL1A1, Hb ḉᴪ, TF, FIX, MBL2, NOS2A, the outputs of sTRAP were inconsistent with the results of EMSA. Furthermore, no p value of the difference between the two scores of binding affinity under the wild and mutant conditions of TFBSs was presented. Nor, were any criteria for preference or selection of any of the measurements of different matrices used for the same analysis.

Conclusion

Our preliminary study indicated some paradoxical results between sTRAP and experimental data. However, to link the data of sTRAP to the biological functions, its optimization via experimental procedures with the integration of expanded data and applying several other bioinformatics tools might be required.
A conditional local existence result for the generalized nonlinear Kawahara equation
Authors: Khorbatly Bashar , Israwi Samer
Published: March 2020

In this paper, a generalized nonlinear Kawahara equation with time
and
space‐dependent coefficient is considered. We show that the construction of solution with a standard fixed point method can be accomplished so that the well‐posedness in
for some
is proved under a specific nonpositive differential condition. We introduce an adequate weight function to define the energy and a nondegenerate condition is assumed on the fifth dispersive coefficient.
Existence and uniqueness of the entropy solution of a stochastic conservation law with a Q‐Brownian motion
Authors: Funaki Tadahisa , Gao Yueyuan , Hilhorst Danielle
Published: March 2020

In this paper, we prove the existence and uniqueness of the entropy solution for a first‐order stochastic conservation law with a multiplicative source term involving a
‐Brownian motion. After having defined a measure‐valued weak entropy solution of the stochastic conservation law, we present the Kato inequality, and as a corollary, we deduce the uniqueness of the measure‐valued weak entropy solution, which coincides with the unique weak entropy solution of the problem. The Kato inequality is proved by a doubling of variables method; to that purpose, we prove the existence and the uniqueness of the strong solution of an associated stochastic nonlinear parabolic problem by means of an implicit time discretization scheme; we also prove its convergence to a measure‐valued entropy solution of the stochastic conservation law, which proves the existence of the measure‐valued entropy solution.
A fractional model for propagation of classical optical solitons by using nonsingular derivative
Authors: Veeresha P. , Prakasha D. G. , Kumar Sunil
Published: March 2020

The Schrödinger equation depends on the physical circumstance, which describes the state function of a quantum‐mechanical system and gives a characterization of a system evolving with time. The essential focus of proposed research is to observe the solution for fractional generalized nonlinear Schrödinger (FGNS) equation using
‐homotopy analysis transform method (
‐HATM). The fractional order derivative is taken in the Atangana‐Baleanu (AB) sense. The physical behaviours of achieved solution for FGNS equation are discussed and sketch out graphically. The existence of the solution for the FGNS equation is presented through theorems 4.1 to 4.3. The proposed numerical simulations confirm the advantages of the AB derivative through
‐HATM. Few numerical experiments were carried out to validate the proposed method. Moreover, numerical simulations are carried out to verify efficiency and robustness of the derived results by considering two cases.
Boundary stabilization of a microbeam model
Authors: Guzmán Patricio
Published: March 2020

In this paper, we study the boundary stabilization of the deflection of a clamped‐free microbeam, which is modeled by a sixth‐order hyperbolic equation. We design a boundary feedback control, simpler than the one designed in Vatankhah et al,2that forces the energy associated to the deflection to decay exponentially to zero as the time goes to infinity. The rate in which the energy exponentially decays is explicitly given.
Broadband electrically tunable VO2‑Metamaterial terahertz switch with suppressed reflection
Authors: Schalch Jacob S. , Chi Yaojia , He Yulian , Tang Yahua , Zhao Xiaoguang , Zhang Xin , Wen Qiye , Averitt Richard D.
Published: March 2020

Devices designed to dynamically control the transmission, reflection, and absorption of terahertz (THz) radiation are essential for the development of a broad range of THz technologies. A viable approach utilizes materials which undergo an insulator‐to‐metal transition (IMT), switching from transmissive to reflective upon becoming metallic. However, for many applications, it is undesirable to have spurious reflections that can scatter incident light and induce noise to the system. We present an electrically actuated, broadband THz switch which transitions from a transparent state with low reflectivity, to an absorptive state for which both the reflectivity and transmission are strongly suppressed. Our device consists of a patterned high‐resistivity silicon metamaterial layer that provides broadband reflection suppression by matching the impedance of free space. This is integrated with a VO2 ground plane, which undergoes an IMT by means of a DC bias applied to an interdigitated electrode. THz time domain spectroscopy measurements reveal an active bandwidth of 700 GHz with suppressed reflection and more than 90% transmission amplitude modulation with a low insertion loss. We utilize finite‐difference time domain (FDTD) simulations in order to examine the loss mechanisms of the device, as well as the sensitivity to polarization and incident angle. This device validates a general approach toward suppressing unwanted reflections in THz modulators and switches which can be easily adapted to a broad array of applications through straightforward modifications of the structural parameters.
Investigation of spectral performance for single‐scan contrast‐enhanced breast CT using photon‐counting technology: A phantom study
Authors: Ruth Veikko , Kolditz Daniel , Steiding Christian , Kalender Willi A.
Published: March 2020

Purpose

Contrast‐enhanced imaging of the breast is frequently used in breast MRI and has recently become more common in mammography. The purpose of this study was to make single‐scan contrast‐enhanced imaging feasible for photon‐counting breast CT (pcBCT) and to assess the spectral performance of a pcBCT scanner by evaluating iodine maps and virtual non‐contrast (VNC) images.

Methods

We optimized the settings of a pcBCT to maximize the signal‐to‐noise ratio between iodinated contrast agent and breast tissue. Therefore, an electronic energy threshold dividing the x‐ray spectrum used into two energy bins was swept from 23.17 keV to 50.65 keV. Validation measurements were performed by placing syringes with contrast agent (2.5 mg/ml to 40 mg/ml) in phantoms with 7.5 cm and 12 cm in diameter. Images were acquired at different tube currents and reconstructed with 300 μm isotropic voxel size. Iodine maps and VNC images were generated using image‐based material decomposition. Iodine concentrations and CT values were measured for each syringe and compared to the known concentrations and reference CT values.

Results

Maximal signal‐to‐noise ratios were found at a threshold position of 32.59 keV. Accurate iodine quantification (average root mean square error of 0.56 mg/ml) was possible down to a concentration of 2.5 mg/ml for all tube currents investigated. The enhancement has been sufficiently removed in the VNC images, so they can be interpreted as unenhanced CT images. Only minor changes of CT values compared to a conventional CT scan were observed. Noise was increased by the decomposition by a factor of 2.62 and 4.87 (7.5 cm and 12 cm phantoms) but did not compromise the accuracy of the iodine quantification.

Conclusions

Accurate iodine quantification and generation of VNC images can be achieved using contrast‐enhanced pcBCT from a single CT scan in the absence of temporal or spatial misalignment. Using iodine maps and VNC images, pcBCT has the potential to reduce dose, shorten examination and reading time, and to increase cancer detection rates.
Nursing diagnosis identification by nurses in burn wards: A descriptive cross‐sectional study
Authors: Khajehgoodari Mohammad , Lotfi Mojgan , Zamanzadeh Vahid , Valizadeh Leila , Khalilzad Parisa
Published: March 2020

Aim

To identify and document patients' care needs, it is vital to provide quality care services. This study was aimed to describe care needs derived from records of patients with burn and to evaluate whether nurses employed the North American Nursing Diagnosis Association classification to formulate patients' care needs.

Design

A descriptive cross‐sectional study.

Methods

In this study using the convenient sampling method, 430 nursing records reviewed in the burn wards. Data were collected using Gordon's checklist. The validity of the checklist assessed by content validity and the reliability of them calculated with inter‐rater and internal consistency. Data analysed by SPSSv.24.

Results

The mean number of diagnoses per record was 1.94. The most frequent diagnosis was in the domain of Safety/Protection and the top two prevalent nursing diagnoses in Sina hospital were a risk for infection and risk for falls. From all of the detected diagnostic, about 83% were determinedly not related to one of 247 labels of the North American Nursing Diagnosis Association. Given that nurses provide nursing care as requested by physicians and patient care needs are not assessed and recorded by them, it can be concluded that there was no nursing thinking behind their nursing care.
Conflicts over wildlife conservation: Learning from the reintroduction of beavers in Scotland
Authors: Coz Deborah M. , Young Juliette C.
Published: March 2020

Species reintroductions have become a common conservation tool, but they can be controversial and may generate social conflicts.

We examine the social dimension of beaver reintroduction in Scotland to understand the issue, the potential for, and impact of, conflict between groups or individuals with differing views on beavers and reintroductions.

Using a literature review and semi‐structured interviews, we studied planned and unplanned beaver reintroductions to three contrasting landscapes in Scotland: in Knapdale, the reintroduction was planned and science‐led, whereas in Tayside and the Highlands, the reintroductions were accidental and/or illegal.

Our results highlight the context dependency and complexity of reintroductions. Nationally, the reintroduction of beavers has not become a conflict. At the local scale, we found the Tayside situation to be a conflict with major consequences on the debate at the national scale. While there were no conflicts in the Highlands and Knapdale, the reintroduction remains controversial.

The level of conflict depended on the reintroduction process, relationships between stakeholders and their perspectives on their role in nature, their perceptions of landscapes, and the potential issue of lack of control and uncertainty around reintroductions.

Based on these findings, the study outlines lessons learned in terms of management, guidelines and implications for future species reintroductions. We argue that to prevent future conflicts over reintroductions, processes must go beyond addressing the effects of reintroduced species on the environment and people's perceptions and acceptance of these species. Reintroduction processes require engagement in effective discussions which involve all actual and potential stakeholders to agree on broad and long‐term conservation plans at the landscape scale.

A freePlain Language Summarycan be found within the Supporting Information of this article.
A streamlined mass spectrometry–based proteomics workflow for large‐scale FFPE tissue analysis
Authors: Coscia Fabian , Doll Sophia , Bech Jacob Mathias , Schweizer Lisa , Mund Andreas , Lengyel Ernst , Lindebjerg Jan , Madsen Gunvor Iben , Moreira José MA , Mann Matthias
Published: March 2020

Formalin fixation and paraffin‐embedding (FFPE) is the most common method to preserve human tissue for clinical diagnosis, and FFPE archives represent an invaluable resource for biomedical research. Proteins in FFPE material are stable over decades but their efficient extraction and streamlined analysis by mass spectrometry (MS)–based proteomics has so far proven challenging. Herein we describe a MS‐based proteomic workflow for quantitative profiling of large FFPE tissue cohorts directly from histopathology glass slides. We demonstrate broad applicability of the workflow to clinical pathology specimens and variable sample amounts, including low‐input cancer tissue isolated by laser microdissection. Using state‐of‐the‐art data dependent acquisition (DDA) and data independent acquisition (DIA) MS workflows, we consistently quantify a large part of the proteome in 100 min single‐run analyses. In an adenoma cohort comprising more than 100 samples, total workup took less than a day. We observed a moderate trend towards lower protein identification in long‐term stored samples (>15 years), but clustering into distinct proteomic subtypes was independent of archival time. Our results underscore the great promise of FFPE tissues for patient phenotyping using unbiased proteomics and they prove the feasibility of analyzing large tissue cohorts in a robust, timely, and streamlined manner. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
The use of Mendelian randomisation to identify causal cancer risk factors: promise and limitations
Authors: Gala Harvinder , Tomlinson Ian
Published: March 2020

The use of observational analyses, such as classical epidemiological studies or randomised controlled trials (RCTs), to infer causality in cancer may be problematic due to both ethical reasons and technical issues, such as confounding variables and reverse causation. Mendelian randomisation (MR) is an epidemiological technique that uses genetic variants as proxies for exposures in an attempt to determine whether there is a causal link between an exposure and an outcome. Given that genetic variants are randomly assigned during meiosis according to Mendel's first and second laws of heritability, MR may be thought of as a ‘natural’ RCT and is therefore less vulnerable to the aforementioned problems. MR has the potential to help identify new, and validate or disprove previously implicated, modifiable risk factors in cancer, but it is not without limitations. This review provides a brief description of the history and principles of MR, as well as a guide to basic MR methodology. The bulk of the review then examines various limitations of MR in more detail, discussing some of the proposed solutions to these problems. The review ends with a brief section detailing the practical implementation of MR, with examples of its use in the study of cancer, and an assessment of its utility in identifying cancer predisposition traits. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Histology of pediatric classic Hodgkin lymphoma: From diagnosis to prognostic stratification
Authors: Pizzi Marco , Tazzoli Sara , Carraro Elisa , Chaviano Felicia , Massano Davide , Lovisa Federica , Mussolin Lara , Todesco Alessandra , Biffi Alessandra , d'Amore Emanuele S. , Pillon Marta , Rugge Massimo
Published: March 2020

Aims

Classic Hodgkin lymphoma (cHL) is a common malignancy of the pediatric age. Although clinical‐radiological features are routinely used for disease risk stratification, the role of tumor histology has yet to be defined. This study aimed to characterize the clinical‐pathological features of a large cohort of pediatric cHL specifically investigating the relevance of tumor histology for the prognostic stratification of patients.

Methods and results

The study considered 96 clinically annotated cases of pediatric cHL treated according to the AIEOP‐LH2004 protocol. The following histological parameters were considered: (i) cHL variant; (ii) grade of nodular sclerosis (NS); (iii) staining for Bcl2 and p53, and expression of B‐cell (BCA) and T‐cell antigens (TCA) by Hodgkin/Reed‐Sternberg cells. The study population consisted of 51 males and 45 females (median age: 13.6 years) with five‐year overall and progression‐free survival of 94% and 81%, respectively. Most cases featured NS morphology (96%) with a prevalence of NS1 over NS2 grades. Two NS2 variants were recognized (sarcomatous/syncytial and fibrohistiocytic). A consistent subset of cases disclosed positivity for BCA (34%), TCA (26%), p53 (13%), and Bcl2 (19%). Clinical‐pathological correlations showed a more aggressive clinical course for NS2 over NS1 cases. The NS2 fibrohistiocytic variant was associated with the worst outcome. No other histological features correlated with prognosis.

Conclusions

Pediatric cHL is a clinically and histologically heterogeneous neoplasm. The majority of cases disclose NS morphology and aberrant phenotypes are frequently encountered. In the pediatric population, NS grading and NS2 subtyping bear significant prognostic impact.
Registration of TARS‐LH1 pinto bean germplasm with resistance to the leafhopper pest
Authors: Porch Timothy G. , Brisco‐McCann Elizabeth I. , Demosthene Gasner , Colbert Raphael W. , Beaver James S. , Kelly James D.
Published: March 2020

Leafhoppers (Empoasca spp.) cause significant yield reductions in common bean (Phaseolus vulgaris L.) and are a particularly important constraint for organic producers. Genetic resistance would benefit both conventional and organic dry and snap bean production threatened by leafhopper damage. Improvement of Empoasca kraemeri leafhopper resistance in tropical germplasm has been successful, but resistance to Empoasca fabae in temperate germplasm has not been broadly pursued. TARS‐LH1 (Reg. no. GP‐306, PI 691505) is a pinto bean germplasm resistant to E. fabae and E. kraemeri. TARS‐LH1 has been adapted to both temperate and tropical growing environments and was developed through the introgression of leafhopper resistance from the Mesoamerican common bean race into the Durango common bean race. TARS‐LH1 also possesses drought tolerance and the I gene for resistance to Bean common mosaic virus, is a near‐commercial pinto bean seed type, and has produced seed yields greater than parental cultivars under leafhopper pressure. This germplasm was developed cooperatively by the USDA‐ARS, Michigan State University, the Ministry of Agriculture of Haiti, and the University of Puerto Rico, Mayaguez.
Radiosensitization effect of selenocystine on HeLa cells in vitro
Authors: Qian Shen , Xie Li‐xin , Li Guo‐bao , Zheng Sha‐sha , Li Na
Published: March 2020

Objectives

To study the effect of selenocystine (Selenocystine, SeC) on the radiosensitivity of human cervical cancer Hela cells, and to provide a new target for radiosensitivity of cervical cancer.

Methods

SeC were added to the cervical cancer Hela cells, and then irradiate with 200 cGy/min X‐rays. The radiosensitization effect of SeC on cervical cancer Hela cells were confirmed with the experiments of cell growth inhibition, clone formation, flow cytometry and Western blotting to detect apoptosis.

Results

SeC were added to the Hela cells at different doses of 0, 5, 10, and 20 μmol/L and incubating for 24 hours, the cell growth inhibition rates were: 0%, 22.68%, 41.71%, 74.19%, and the calculated IC50 was 14.83 μmol/L. The growth inhibition rate of Hela cells was dose‐dependent with the concentration of SeC. The results of the colony formation experiments showed that the cell colony formation rates of the single X‐ray irradiation doses of 0, 2, 4, 6, and 8 Gy were 100%, 77.56%, 46.89%, 28.67%, and 10.89%, respectively. After adding 5μmol/L SeC under the same irradiation dose, the colony formation rate was reduced to 70.98%, 59.45%, 30.67%, 14.29%, 3.72%; 5μmol/L SeC combined with radiation therapy can shift the survival curve to the left, and the D0 and Dq values were significantly smaller than those in the radiation group, P < 0.05. Hela cell apoptosis were detected by the flow cytometry showed that when the single X‐ray irradiation dose was 0, 2, 4, 8 Gy, the apoptosis scores were: 2.51 ± 0.06, 6.76 ± 0.03, 14.51 ± 0.15, 21.41 ± 0.08; When 5 μmol/L SeC was added and then combined with X‐ray irradiation, and the irradiation dose was 0, 2, 4, 8Gy, the apoptosis score of each group was: 10.89 ± 0.36, 15.18 ± 0.21, 31.19 ± 0.08, 45.53 ± 0.28, SeC combined with X‐ray had an interaction effect on Hela cells, and the apoptosis rate increased (F = 21.52, P < 0.01). When Hela cells were treated with SeC and X‐rays, the expression of PARP protein and phosphorylated p53 protein was significantly increased compared with the control group.

Conclusions

SeC may have a radiosensitizing effect on Hela cells, and its mechanism may be related to promoting apoptosis. SeC will be expected to become a new sensitization target for cervical cancer radiotherapy.
Stratified rank histograms for ensemble forecast verification under serial dependence
Authors: Bröcker Jochen , Ben Bouallègue Zied
Published: March 2020

Rank histograms are a popular way to assess the reliability of ensemble forecasting systems. If the ensemble forecasting system is reliable, the rank histogram should be flat, “up to statistical fluctuations.” There are two long‐noted challenges to this approach. Firstly, uniformity of the overall distribution is implied by but does not imply reliability; ideally the distribution of the ranks should be uniform even conditionally on different forecast scenarios. Secondly, the ranks are serially dependent in general, precluding the use of standard goodness‐of‐fit tests to assess the uniformity of rank distributions without any further precautions. The present paper deals with both these issues by drawing together the concept of stratified rank histograms, which have been developed to deal with the first issue, with ideas that exploit the reliability condition to manage the serial correlations, thus dealing with the second issue. As a result, tests for uniformity of stratified rank histograms are presented that are valid under serial correlations.
Applications of directional wavelets, Universal Multifractals and anisotropic scaling in ensemble nowcasting; a review of methods with case‐studies
Authors: Scovell Robert W.
Published: March 2020

This article begins with a review of the scale decomposition and stochastic noise generation aspects of the ensemble nowcasting process, as used in the Short Term Ensemble Prediction System (STEPS). Alternative methods are then suggested, with case‐study examples, which could lead to enhanced performance and may also be applicable in other fields. The standard FFT‐band‐pass‐filtering scale decomposition, essential to this process, is shown to be practically the same as a redundant Continuous Wavelet Transform (CWT). This immediately makes accessible a number of more advanced methods from the wavelet literature. Particular attention is given to directional wavelet transforms and their use for analysing anisotropic scaling behaviour, common in weather images. With a view to numerically efficient operational usage, the focus is then shifted to Discrete Wavelet Transforms (DWTs). While the standard DWT has a number of disadvantages, including limited orientational selectivity in two dimensions, the relatively recent Dual Tree Complex WT (DTCWT) overcomes most of these. Examples are given that show how its six‐fold directionality can be exploited, to create synthetic features that replace the unpredictable small‐scale parts of a (weather‐radar‐based) extrapolation nowcast with more realistic spatially varying anisotropy. Further, the Bounded Log‐normal Cascade noise model, as used in STEPS, is reconsidered and a proposal to use Universal Multifractal realizations is presented. For the noise parameters, some operationally viable estimation methods are considered, such as the Double Trace Moment technique and a structure‐function‐based approach, which could work on readily available DTCWT coefficients.
Barotropic modes, baroclinic modes and equivalent depths in the atmosphere
Authors: De‐Leon Yair , Paldor Nathan , Garfinkel Chaim I.
Published: March 2020

The equivalent depth of a rotating fluid layer determines the phase speed of all free (i.e. unforced) linear waves that propagate in it. The equivalent depth can be estimated from the eigenvalues of a second‐order differential equation for the vertical dynamics where the mean temperature profile is a coefficient. The eigenfunctions dictate the vertical structure of the modes. This work combines analytic and numerical solutions of the vertical structure equation for various mean temperature profiles and for various combinations of top and bottom boundary conditions relevant to two atmospheric configurations: troposphere and combined troposphere‐stratosphere. Our formulation provides a clear definition of the barotropic mode and the countable baroclinic modes (including the special n = 0 mode). The barotropic mode exists only when the lower boundary condition is the vanishing of the vertical velocity (i.e. when a solid boundary bounds the layer from below) and the equivalent depth of this mode is about 10 km. The n = 0 baroclinic mode does not exist in a layer whose thickness exceeds a threshold value of about 20 km and therefore this mode does not exist in the combined troposphere‐stratosphere layer. The upper boundary condition affects the eigenvalues much more so than the details of the temperature profile, as the details of the temperature profile only affect the equivalent depth in the troposphere. Increasing the height of the upper boundary has little effect on the barotropic mode, but strongly influences the phase speed and vertical structure of the baroclinic modes; a general circulation model with a lid at or below the stratopause where, for example, planetary Rossby waves are present will therefore be incapable of correctly simulating the interaction of these waves with the mean flow. The values of the equivalent depth of baroclinic modes are approximately 10% of the actual layer's depth in all realistic cases.
Detection of ergosterol using liquid chromatography/electrospray ionization mass spectrometry: Investigation of unusual in‐source reactions
Authors: Ory Lucie , Gentil Emmanuel , Kumla Decha , Kijjoa Anake , Nazih El‐Hassane , Roullier Catherine
Published: March 2020

Rationale

In the field of natural products, de‐replication of complex mixtures has become a usual practice to annotate known compounds and avoid their re‐isolation. For this purpose, many groups rely on liquid chromatography coupled to high‐resolution mass spectrometry (HPLC/MS) to deduce molecular formulae of compounds allowing comparison with public or in‐house databases. Electrospray ionization (ESI) is usually considered as the method of choice for investigating a large panel of compounds but, in some cases, it may lead to unusual results as described in this article for ergosterol.

Methods

Ergosterol and other fungal sterols in methanolic solution were analysed using various chromatographic gradients with HPLC/MS using both ion trap time‐of‐flight MS and Orbitrap MS instruments fitted with an ESI source. Further flow injection analyses were performed to investigate the influence of the solvent composition. MS/MS fragmentation data were acquired to annotate the various ions observed.

Results

Contrary to other fungal sterols, ergosterol was found to be highly sensitive to oxidation during ESI. Putative structures were proposed based on MS/MS studies and known oxidation mechanisms of ergosterol by reactive oxygen species that could be formed in the ESI process. The proportion of acetonitrile in the eluent was found to influence this in‐source oxidation, with an increased proportion of oxidized sodium adducts with higher proportions of acetonitrile.

Conclusions

While ergosterol is a major sterol found in fungi, this study investigates its ionization by electrospray for the first time. The results reported here will help further detection and annotation of this compound in fungal extracts after HPLC/ESI‐MS analyses.
Tegafur/gimeracil/oteracil‐induced eosinophilic pneumonia
Authors: Sumi Toshiyuki , Nakata Hisashi , Mori Yuji , Takahashi Hiroki
Published: March 2020

Key message

Clinicians should be aware that eosinophilic pneumonia is one of the types of drug‐induced lung injury that can be caused by tegafur/gimeracil/oteracil (TS‐1).
Data‐driven robust backstepping control of unmanned surface vehicles
Authors: Weng Yongpeng , Wang Ning
Published: March 2020

In this article, a novel data‐driven robust backstepping control (DRBC) approach for tracking of unmanned surface vehicles (USVs) with uncertainties and unknown parametric dynamics has been developed. Main contributions are fourfold: (a) Unlike previous approaches, within the DRBC scheme, backstepping decoupled technique and data‐driven sliding‐mode control (DSMC) can be effectively cohered. (b) Using backstepping philosophy, a new data‐driven PI‐type sliding‐mode surface is devised, such that strong robustness with simple structure can be ensured. (c) Complex unknowns including couplings, uncertainties and parametric dynamics are sufficiently lumped, and are totally compensated by the extended state observer. (d) The entire DRBC scheme eventually achieves accurate tracking of USVs with strong couplings, uncertainties and unknown parametric dynamics. The efficacy and superiority of the proposed DRBC approach is validated on a prototype
USV.
Spectral reflectance of whale skin above the sea surface: a proposed measurement protocol
Authors: Cubaynes Hannah C. , Rees W. Gareth , Jackson Jennifer A. , Moore Michael , Sformo Todd L. , McLellan William A. , Niemeyer Misty E. , George John C. , van der Hoop Julie , Forcada Jaume , Trathan Phil , Fretwell Peter T.
Published: March 2020

Great whales have been detected using very‐high‐resolution satellite imagery, suggesting this technology could be used to monitor whales in remote areas. However, the application of this method to whale studies is at an early developmental stage and several technical factors need to be addressed, including capacity for species differentiation and the maximum depth of detection in the water column. Both require knowledge of the spectral reflectance of the various whale species just above the sea surface, as when whales bodies break the surface of the water to breath, log or breach, there is, at times, no sea water between the whale's skin and the satellite sensor. Here we tested whether such reflectance could be measured on dead whale tissue. We measured the spectral reflectance of fresh integument collected during the bowhead subsistence harvest, and of thawed integument samples from various species obtained following strandings and stored at −20°C. We show that fresh and thawed samples of whale integument have different spectral properties. The reflectance of fresh samples was higher than the reflectance of thawed samples, as integument appears to darken after death and with time, even under frozen conditions. In this study, we present the first whale reflectance estimates (without the influence of sea water and for dead tissue). These provide a baseline for additional work, needed to advance the use of satellite imagery to monitor whales and facilitate their conservation.
Stimulation of L-type calcium channels increases tyrosine hydroxylase and dopamine in ventral midbrain cells induced from somatic cells
Authors: Jefri Malvin , Bell Scott , Peng Huashan , Hettige Nuwan , Maussion Gilles , Soubannier Vincent , Wu Hanrong , Silveira Heika , Theroux Jean-Francois , Moquin Luc , Zhang Xin , Aouabed Zahia , Krishnan Jeyashree , O’Leary Liam A. , Antonyan Lilit , Zhang Ying , McCarty Vincent , Mechawar Naguib , Gratton Alain , Schuppert Andreas , Durcan Thomas M. , Fon Edward A. , Ernst Carl
Published: March 2020

Making high-quality dopamine (DA)-producing cells for basic biological or small molecule screening studies is critical for the development of novel therapeutics for disorders of the ventral midbrain. Currently, many ventral midbrain assays have low signal-to-noise ratio due to low levels of cellular DA and the rate-limiting enzyme of DA synthesis, tyrosine hydroxylase (TH), hampering discovery efforts. Using intensively characterized ventral midbrain cells derived from human skin, which demonstrate calcium pacemaking activity and classical electrophysiological properties, we show that an L-type calcium agonist can significantly increase TH protein levels and DA content and release. Live calcium imaging suggests that it is the immediate influx of calcium occurring simultaneously in all cells that drives this effect. Genome-wide expression profiling suggests that L-type calcium channel stimulation has a significant effect on specific genes related to DA synthesis and affects expression of L-type calcium receptor subunits from the CACNA1 and CACNA2D families. Together, our findings provide an advance in the ability to increase DA and TH levels to improve the accuracy of disease modeling and small molecule screening for disorders of the ventral midbrain, including Parkinson’s disease.

Significance statement A single molecule provides a major boost to both tyrosine hydroxylase and dopamine in stem cell-derived human ventral midbrain cells.
Green Synthesis of Silver Nanoparticles Using Tea Leaves from Three Different Elevations
Authors: Chandra Abhishek , Bhattarai Ajaya , Yadav Ashok K. , Adhikari Janak , Singh Man , Giri Basant
Published: March 2020

Green synthesis of nanoparticles offers numerous advantages over the conventional methods. This work provides a comprehensive understanding on the effect of tea cultivation elevation on the formation of silver nanoparticles (AgNPs) using green tea (Camellia Sinensis) leaves. The green tea leaves were collected from three different elevations: 86, 1700, and 2000 m above sea level in eastern Nepal. We found that AgNPs synthesized using tea leaves from 1700 m were homogeneously dispersed and smallest size, when compared to AgNPs synthesized using tea leaves from remaining two elevations. All aqueous dispersed AgNPs were sensitive towards mercury (II) ion over a range of other metal ions tested. However, the AgNPs synthesized using tea leaves from 1700 m resulted in better detection limit of 9.79 μM for sensing mercury (II) ions. Interestingly, the nanoparticles when additionally stabilized in aqueous trimethyloctylammonium bromide, a cationic surfactant among seven other surfactants tested, improved the detection limit to 0.71 μM.
Photolysis Mechanism of Quaternary Amidinium Salts
Authors: Shiraishi Atsushi , Yamashita Takashi
Published: March 2020

Photoinduced polymerization reactions are an energy‐saving and environmentally friendly technology used in applications such as curing and coating. Photo initiators are one of the key materials which generate active species by photoirradiation. Many types of radical and cationic photo initiators (photoacid generators) have been developed. However, anionic photo initiators (photobase generators), which are more advantageous in terms of corrosion and lack of deactivation, remain under development. Cyclic amidine compounds, such as DBU® (1,8‐Diazabicyclo[5.4.0]undec‐7‐ene) and DBN (1,5‐Diazabicyclo[4.3.0]non‐5‐ene), are strong organic bases, widely used as catalysts in organic, polymerization, and crosslinking reactions. Developing a photobase initiator that can generate such a strong base is important, because there are few photobase generators with strong basicity and high reactivity for practical applications. In this study, we investigated the elementary mechanism of photolysis of quaternary amidinium borate salts by transient absorption measurements. We confirm that photoinduced electron transfer is a key step in the photo decomposition of quaternary amidinium borate salts and that the position of the sensitizing chromophore in the molecules significantly affects the decomposition efficiency.
The Use of D’ Index in the Determination of the Aromatic Character of Organic Compounds. Comparison with HOMHED and NICS.
Authors: D'Auria Maurizio
Published: March 2020

The comparison of D index with HOMHED gave a good correlation (R2= 0.8221). However, a modification of D index, namely D’, where the number of cycles involved in the tested molecule is substituted by the ratio between the number of atoms involved in π orbitals in the tested molecule and in reference molecule, gave a better correlation with a larger number of compounds (R2=0.8819), The correlation of D’ with calculated HOMHED for pentatomic heterocyclic compounds did not give a unique correlation but a series of possible correlations. This behavior depends on the parameters used for the calculation of HOMHED that allow some negative values. In fact, the comparison of D’ with NICS for selected pentatomic heterocycles gave good correlation. Good correlations were observed also in the comparison of D’ with HOMHED and NICS for antiaromatic compounds.
Weighting the domain of probability densities in functional data analysis
Authors: Talská Renáta , Menafoglio Alessandra , Hron Karel , Egozcue Juan José , Palarea‐Albaladejo Javier
Published: March 2020

In functional data analysis, some regions of the domain of the functions can be of more interest than others owing to the quality of measurement, relative scale of the domain, or simply some external reason (e.g. interest of stakeholders). Weighting the domain is of interest particularly with probability density functions (PDFs), as derived from distributional data, which often aggregate measurements of different quality or are affected by scale effects. A weighting scheme can be embedded into the underlying sample space of a PDF when it is considered as continuous compositions applying the theory of Bayes spaces. The origin of a Bayes space is determined by a given reference measure, and this can be easily changed through the well‐known chain rule. This work provides a formal framework for defining weights through a reference measure, and it is used to develop a weighting scheme on the bounded domain of distributional data. The impact on statistical analysis is illustrated through an application to functional principal component analysis of income distribution data. Moreover, a novel centred log‐ratio transformation is proposed to map a weighted Bayes space into an unweighted
space, enabling to use most tools developed in functional data analysis (e.g. clustering and regression analysis) while accounting for the weighting scheme. The potential of our proposal is shown on a real case study using Italian income data.
Mechanical behavior of precast building concrete walls with different connection technologies for seismic areas
Authors: Yuan‐Yuan Peng , Yu‐Hang Wang , Jia‐Ru Qian
Published: March 2020

In order to study the seismic behavior of precast concrete walls with different connection types for vertical reinforcements, the quasi‐static test on five concrete shear walls, including precast shear walls and cast‐in‐place shear wall was carried out. Test results showed that the failure mode of precast concrete walls was nearly the same as that of the cast‐in‐place concrete shear wall: in boundary elements at bottom of the shear wall, the vertical reinforcements yielded under tension, and the concrete was crushed under compression. The stress of vertical reinforcements could be effectively transferred by the sleeve‐mortar splicing. The specimen with hoop stirrup splicing had in‐plane rigid slide between the precast region and the cast‐in‐place region, whose ultimate drift ratio and energy dissipation capacity were lowest. The ultimate drift ratio of all specimens was larger than 1%. Based on results and analysis, recommendations for practical design for precast shear wall structures were proposed.