bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheric corrosion of zinc in coastal atmospheres
Authors: Fuentes María , de la Fuente Daniel , Chico Belén , Llorente Irene , Jiménez José Antonio , Morcillo Manuel
Published: January 2019

The atmospheric corrosion of zinc in pure marine coastal atmospheres has not been extensively studied. This paper presents the results obtained in six pure marine atmospheres located at different distances from the seashore in the same coastal area with annual chloride deposition rates of between 47 and 1142 mg · m−2 · day−1. Zinc specimens were exposed for 3, 6, 9, and 12 months in two annual exposure sequences starting 6 months apart. Tests were performed to determine the corrosion rate and its evolution with exposure time. Quantitative (Rietveld) grazing X‐ray diffraction and X‐ray photoelectron spectroscopy (C 1s) were applied to analyze the corrosion products formed. Scanning electron microscopy/energy dispersive X‐ray spectrometry were employed to study the morphology of the corrosion layers. The most relevant findings of this study are: (a) the presence of hydrozincite [Zn5(CO3)2(OH)6]; (b) the aqueous precipitation can be a major controlling factor of the atmospheric corrosion of zinc in atmospheres with low chloride deposition rates (30–50 mg · m−2 · day−1); and (c) the formation of zinc hydroxysulfates also takes place due to the presence of sulfate ions in the marine aerosol.
IL‐4 gene polymorphisms and their relation to steroid‐induced osteonecrosis of the femoral head in Chinese population
Authors: Jin Tianbo , Zhang Yiming , Sun Yao , Wu Jiamin , Xiong Zichao , Yang Zhi
Published: January 2019

Background

Steroid‐induced osteonecrosis of the femoral head (ONFH) is a debilitating disease characterized by the activation and infiltration of macrophages into the necrotic site. Interleukin‐4 (IL‐4) administration helped reduce the infiltration of M1 phenotypic macrophages and maintain the activation of M2 phenotypic macrophages, resulting in restriction of inflammation and decrease in osteocyte apoptosis. The aim of this study was to investigate the associations of polymorphisms of IL‐4 gene with steroid‐induced ONFH in Chinese patients.

Materials and methods

A total of 286 steroid‐induced ONFH patients and 441 healthy controls were enrolled. We evaluated 6 single nucleotide polymorphisms of the IL‐4 gene in this case–control study.

Results

We identified rs2243283 in the IL‐4gene was potentially associated with an increased risk of steroid‐induced ONFH in the dominant model (p = 0.034; odds ratio [OR]: 1.40; 95% confidence intervals [CI]: 1.03–1.91) and in the log‐additive model (p = 0.04; OR: 1.31; 95% CI: 1.01–1.71) adjusted by age and gender. Furthermore, we also observed a protective effect of rs2243289 in the dominant model (p = 0.024; OR: 0.70; 95% CI: 0.51–0.95) adjusted by age and gender.

Conclusion

These findings suggested that polymorphisms of IL‐4 gene may be associated with susceptibility to steroid‐induced ONFH.
Tau protein function: The mechanical exploration of axonal transport disorder caused by persistent pressure in dorsal root ganglia
Authors: Zhang Lei , Fu Jun , Cheng Xin‐Hua , Tang Li
Published: January 2019

Objective

We analyzed the function of Tau protein to explore the underlying mechanism of axonal transport disorder caused by persistent pressure in the dorsal root ganglia (DRG).

Methods

Wistar rats were divided into the sham operated group, the control group and the experimental group. The Wistar rat model of continuous compression of DRG was used for further investigation. DRG neurons were extracted and cultured, and the protein content was detected using bicinchoninic acid method. Western blotting and immunofluorescence assays were performed to detect the protein content. Intraperitoneal injection of lithium chloride was performed for interaction with Tau. The results were then analyzed statistically.

Results

After 2 weeks of sustained pressure, the expression level of Tau396 increased by 33%, while Tau404 increased by 25% in the DRG of the experimental group (p < 0.05). The expression level of PSD‐95 in the DRG decreased by 15% (p < 0.05), while the expression of vGluT1, vGluT3 and vAchT decreased significantly in the DRG of the experimental group (p < 0.05). There was no significant difference in the expression of vGluT2 and vGAT among the three groups (p > 0.05). After intervention with lithium chloride, the expression of phosphorylated Tau at the above sites decreased in varying degrees compared with the model group. The expression level of Tau404 was reduced by 55%, and that of Tau199 by 60% in the DRG of the experimental group.

Conclusion

Chronic compression of DRG and hypoxia caused phosphorylation of Tau in axons and inhibition of PSD‐95, and the function of the synaptic glutamic acid vesicle is defective in the synapse. This process is crucial in the development and progression of axonal transport dysfunction induced by chronic DRG compression, and phosphorylation of Tau plays a substantial role in this process.
Fractional powers of the noncommutative Fourier's law by the S‐spectrum approach
Authors: Colombo Fabrizio , Mongodi Samuele , Peloso Marco , Pinton Stefano
Published: January 2019

Let eℓ, for ℓ = 1,2,3, be orthogonal unit vectors in
and let
be a bounded open set with smooth boundary ∂Ω. Denoting by
a point in Ω, the heat equation, for nonhomogeneous materials, is obtained replacing the Fourier law, given by the following:

urn:x-wiley:mma:media:mma5466:mma5466-math-0004
into the conservation of energy law, here a, b,
are given functions. With the S‐spectrum approach to fractional diffusion processes we determine, in a suitable way, the fractional powers of T. Then, roughly speaking, we replace the fractional powers of T into the conservation of energy law to obtain the fractional evolution equation. This method is important for nonhomogeneous materials where the Fourier law is not simply the negative gradient. In this paper, we determine under which conditions on the coefficients a, b,
the fractional powers of T exist in the sense of the S‐spectrum approach. More in general, this theory allows to compute the fractional powers of vector operators that arise in different fields of science and technology. This paper is devoted to researchers working in fractional diffusion and fractional evolution problems, partial differential equations, and noncommutative operator theory.
Comparison of two reliable methods to solve fractional Rosenau‐Hyman equation
Authors: Senol Mehmet , Tasbozan Orkun , Kurt Ali
Published: January 2019

In this study, we examine the numerical solutions of the time‐fractional Rosenau‐Hyman equation, which is a KdV‐like model. This model demonstrates the formation of patterns in liquid drops. For this purpose, two reliable methods, residual power series method (RPSM) and perturbation‐iteration algorithm (PIA), are used to obtain approximate solutions of the model. The fractional derivative is taken in the Caputo sense. Obtained results are compared with each other and the exact solutions both numerically and graphically. The outcome shows that both methods are easy to implement, powerful, and reliable. So they are ready to implement for a variety of partial fractional differential equations.
Cafeteria Diet Consumption during Lactation in Rats, Rather than Obesity Per Se, alters miR‐222, miR‐200a, and miR‐26a Levels in Milk
Authors: Pomar Catalina A. , Castro Heriberto , Picó Catalina , Serra Francisca , Palou Andreu , Sánchez Juana
Published: January 2019

Scope

The aim of the present study is to investigate in nursing rats the impact of cafeteria‐diet feeding during lactation (cafeteria dams) on specific miRNA levels in breast milk and to discern them from the effects of maternal adiposity per se (postcafeteria dams).

Methods and results

Milk samples are collected from control, cafeteria, and postcafeteria dams at three time points of lactation (days 5, 10, and 15) and levels of selected miRNAs (miR‐222, miR‐203, miR‐200a, miR‐103, miR‐27a, and miR‐26a) were determined. Levels in milk of miR‐222 rise while miR‐103 and miR‐27 fall throughout lactation. Moreover, at day 15 of lactation, cafeteria dams present higher miR‐222 and lower miR‐200a and miR‐26a levels in milk than controls. No differences are found in postcafeteria dams compared with controls. At weaning, the offspring of cafeteria dams, but not the offspring of postcafeteria dams, displays lower expression levels of Cdkn1c (a validated target gene of miR‐222) in liver than controls.

Conclusion

Cafeteria diet intake in nursing rats, rather than obesity per se, leads to alterations in specific miRNA levels, which, through the milk supply, may alter expression of target genes and potentially affect offspring phenotype.
Composite Particles From Pickering‐Stabilized Radical Mediated Thiol‐Ene Suspension Polymerizations
Authors: Cassidy Kyle J. , Durham Olivia Z. , Shipp Devon A.
Published: January 2019

Pickering stabilization is a facile method to create composite colloidal particles. Inorganic colloidal SiO2 nanoparticles are often used as the stabilizer for particles instead of the more common amphiphilic surfactants. Here the use of this approach in radical‐mediated thiol‐ene suspension polymerizations using monomers 1,3,5‐triallyl‐1,3,5‐triazine‐2,4,6(1H,3H,5H)‐trione (TTT) and pentaerythritol tetrakis (3‐mercaptopropionate) (PETMP) is described. The resulting micron‐sized crosslinked poly(thioether) colloidal particles are coated with 80 nm silica nanoparticles. The addition of a small amount of various costabilizers is examined (hexadecane, cetyl alcohol and toluene), and while all yielded particles, cetyl alcohol provide more consistent results. Scanning electron microscopy and thermal analysis of the composite particles demonstrate morphologies that are consistent with a raspberry‐like structure. No significant changes to the glass transition temperature are observed, which is consistent with the silica nanoparticles being located at the surface of the polymer particles.
Inhibition of microRNA‐92a increases blood vessels and satellite cells in skeletal muscle but does not improve duchenne muscular dystrophy–related phenotype in mdx mice
Authors: Verma Mayank , Asakura Yoko , Asakura Atsushi
Published: January 2019

Introduction: The vasculature and blood flow in muscle are perturbed in Duchenne muscular dystrophy (DMD) and its mdx mouse model. MicroRNA‐92a (miR‐92a) is enriched in endothelial cells, especially during ischemic injury. Methods: Because antagonizing miR‐92a was shown to result in increased proliferation and migration of endothelial cells and recovery from ischemia, we assessed the effects of Antagomir‐92a in vitro in muscle stem cell culture and in vivo in mdx mice. Results: miR‐92a was found to be highly expressed in muscle endothelial cells and satellite cells. Treatment with Antagomir‐92a increased capillary density and tissue perfusion, which was accompanied by an increase in satellite cells. However, Antagomir‐92a–treated mdx mice showed no histological improvement and had worse muscle function. Antagomir‐92a suppressed myogenic differentiation in satellite cell culture. Discussion: AntagomiR‐92a improves the vasculature but not the muscle in mdx mice, possibly due to its side effects on satellite cell differentiation. Muscle Nerve 59:594–594, 2019
Diffusion‐weighted magnetic resonance imaging is useful for assessing inflammatory myopathies
Authors: Faruch Marie , Garcia Ana Isabel , Del Amo Montse , Pomes Jaume , Isern Jaime , González Sergio Prieto , Grau Josep María , Milisenda José César , Tomas Xavier
Published: January 2019

Introduction: Short tau inversion recovery (STIR) sequences in whole‐body MRI are usually used for detecting muscle edema (ME) in inflammatory myopathies. We evaluated b‐value 800 diffusion‐weighted imaging (b800 DWI).Methods: Two radiologists independently and a consensus reader retrospectively reexamined 60 patients with inflammatory myopathies and 15 controls. For each participant, 78 muscles were analyzed with 3 sets of imaging acquisitions: T1‐weighted (T1) turbo spin echo and STIR; T1 and DWI; and T1, STIR and DWI. Mean edema per patient was compared between sequences. Agreement was evaluated. Results: Diffusion‐weighted imaging detected more ME compared with STIR (P < 0.001). Agreement between readers was better with both sequences (k = 0.94) than with b800 DWI (k = 0.89) or STIR (k = 0.84) alone. Discussion: Diffusion‐weighted imaging is a valuable add‐on for the study of inflammatory myopathies. Muscle Nerve 59:555–555, 2019
Exploring the introduction of European dogs to North America through shoulder height
Authors: Welker Martin H. , Dunham Rebecca
Published: January 2019

The introduction of domesticated species to new environments has been used to identify colonisation events in the archaeological record but rarely provides the opportunity to investigate colonists' selection of particular breeds or stock. This analysis employs morphometrics, the measurement of skeletal landmarks, supported by historic documentation to explore the intersection between colonists' breed preferences and species translocation. In doing so, this analysis provides insight into the differential effects of human selective breeding on domestic dog's (Canis familiaris) physical characteristics in Native American and European societies. Historic sources suggest that European colonists selectively imported large dog breeds capable of defending settlements and livestock, acting as war dogs, and aiding hunters. Colonists' dogs are reputed to have been significantly larger than Native American dogs. This study compares standardised measurements taken on bones to estimate shoulder height. We find that dog populations in England and North America spanning the period 0–1,800 AD exhibit an almost identical average stature; however, the range of shoulder height variation in European dogs is far greater than seen in eastern Native American dog populations. Dogs in colonial American contexts are statistically larger than both Native American and European dog populations, supporting documentary accounts that colonists selectively imported breeds from the largest available in Europe.
Healthy Body Weight may Modify Effect of Abnormal Birth Weight on Metabolic Syndrome in Adolescents
Authors: Dong Bin , Dong Yan‐Hui , Yang Zhao‐Geng , Wang Xi‐Jie , Zou Zhi‐Yong , Wang Zhiqiang , Ma Jun
Published: January 2019

Objective

This study aimed to examine the association between birth weight (BW) and metabolic syndrome (MetS) in adolescents and to further investigate whether having a healthy body weight could modify the potential adverse influence of abnormal BW on MetS risk.

Methods

A total of 6,206 participants aged 10 to 17 years were recruited using data from a Chinese national survey conducted in 2012. Gestational age‐specific BW percentiles were used to classify small for gestational age (SGA), appropriate for gestational age, and large for gestational age (LGA). Fractional polynomial regression, logistic regression, and population‐attributable risk (PAR) were used to assess the relationship between BMI and BW with MetS.

Results

MetS risk increased by 73% (OR = 1.73, 95% CI: 1.06‐2.84) in SGA adolescents with overweight or obesity, but not in those without overweight, compared with their counterparts with BW appropriate for gestational age. A huge difference between PAR percent of MetS because of SGA and PAR percent because of overweight or obesity was detected. For example, PAR percent of SGA was 2.4% (95% CI: 0.1%‐4.6%) in adolescents with overweight or obesity, while PAR percent of overweight or obesity was 44.2% (95% CI: 33.3%‐53.2%) in those who were SGA infants.

Conclusions

These findings suggest that healthy body weight could relieve the adverse impact of SGA on MetS in adolescents.
TBX3 promotes progression of pre‐invasive breast cancer cells by inducing EMT and directly up‐regulating SLUG
Authors: Krstic Milica , Kolendowski Bart , Cecchini Matthew J , Postenka Carl O , Hassan Haider M , Andrews Joseph , MacMillan Connor D , Williams Karla C , Leong Hon S , Brackstone Muriel , Torchia Joseph , Chambers Ann F , Tuck Alan B
Published: January 2019

The acquisition of cellular invasiveness by breast epithelial cells and subsequent transition from ductal carcinoma in situ (DCIS) to invasive breast cancer is a critical step in breast cancer progression. Little is known about the molecular dynamics governing this transition. We have previously shown that overexpression of the transcriptional regulator TBX3 in DCIS‐like cells increases survival, growth, and invasiveness. To explore this mechanism further and assess direct transcriptional targets of TBX3 in a high‐resolution, isoform‐specific context, we conducted genome‐wide chromatin‐immunoprecipitation (ChIP) arrays coupled with transcriptomic analysis. We show that TBX3 regulates several epithelial–mesenchymal transition (EMT)‐related genes, including SLUG and TWIST1. Importantly, we demonstrate that TBX3 is a direct regulator of SLUG expression, and SLUG expression is required for TBX3‐induced migration and invasion. Assessing TBX3 by immunohistochemistry in early‐stage (stage 0 and stage I) breast cancers revealed high expression in low‐grade lesions. Within a second independent early‐stage non‐high‐grade cohort, we observed an association between TBX3 level in the DCIS and size of the invasive focus. Additionally, there was a positive correlation between TBX3 and SLUG, and TBX3 and TWIST1 in the invasive carcinoma. Pathway analysis revealed altered expression of several proteases and their inhibitors, consistent with the ability to degrade basement membrane in vivo. These findings strongly suggest the involvement of TBX3 in the promotion of invasiveness and progression of early‐stage pre‐invasive breast cancer to invasive carcinoma through the low‐grade molecular pathway. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Delirium in the pediatric hematology, oncology, and bone marrow transplant population
Authors: Winsnes Katrina , Sochacki Paul , Eriksson Carl , Shereck Evan , Recht Michael , Johnson Kyle , Loret De Mola Rebecca , Stork Linda
Published: January 2019

Background

Delirium affects 10% to 30% of patients in pediatric intensive care units (PICU) and is associated with increased length of stay and prolonged late sequela. There are no prospective trials evaluating delirium in the pediatric hematology, oncology, and bone marrow transplant (PHO) population. Hypothesizing that delirium is underrecognized in this population, our study aimed to identify the prevalence of delirium in hospitalized PHO patients and associated risk factors.

Procedure

PHO and PICU nurses were trained to use the Cornell Assessment for Pediatric Delirium and to record scores once every 12‐hour shift. Predetermined demographic and clinical variables were collected daily on all hospitalized PHO patients during the year‐long prospective study.

Results

Prior to initiating routine delirium screening, 1.1% of PHO admissions and 2.4% of unique patients had delirium mentioned in a progress note. This study included 807 consecutive admissions: 671 oncology, 49 hematology, and 87 bone marrow transplant (BMT) hospitalizations among 223 unique PHO patients. The prevalence of delirium among hospitalizations was 5% and among unique patients was 13%. Among BMT hospitalizations, the prevalence was 23%. Multiple logistic regression identified significant association of delirium with increased length of stay, admission to the BMT service, patient location (PICU vs PHO unit), benzodiazepine, opioid, and anticholinergic administration.

Conclusions

Before routine screening, delirium was underrecognized in this PHO‐hospitalized population. Patients at highest risk had prolonged hospital stays, PICU admissions, BMT, and/or frequent use of benzodiazepines, opioids, or anticholinergics. Routine screening is feasible and may improve our recognition of delirium.
Characteristics of referred patients with twin‐twin transfusion syndrome who did not undergo fetal therapy
Authors: Sasso Elizabeth B. , Hardley Macy T. , Bottura Isabela , Korst Lisa M. , Ouzounian Joseph G. , Chmait Ramen H.
Published: January 2019

Introduction

Abundant research has reported twin‐twin transfusion syndrome (TTTS) outcomes following fetal therapy. Our research describes TTTS patients who did not undergo fetal therapy.

Methods

Records from TTTS pregnancies evaluated at 16 to 26 gestational weeks were reviewed between January 2006 and March 2017. The study population comprised subjects who did not undergo fetal therapy. Based on initial consultation, patients were grouped as nonsurgical vs surgical candidates. TTTS progression and perinatal outcomes were assessed.

Results

Of 734 TTTS patients evaluated, 68 (9.3%) did not undergo intervention. Of these, 62% were nonsurgical candidates and 38% were surgical candidates. Nonsurgical candidates were ineligible for treatment because of fetal demise or maternal factors (placental abruption, severe membrane separation, and preterm labor). Of surgical candidates, 11 underwent expectant management, eight elected pregnancy termination, and seven planned fetal intervention but had a complication before the procedure. TTTS progression occurred in 10 (15.2%) of 66 cases. Neonatal survival in 64 cases was as follows: in 41 (64%), no survivors; in 11 (17.2%), one survivor; and in 12 (18.8%), two survivors.

Conclusion

Nine percent of referred TTTS patients did not undergo fetal therapy, with many ineligible because of morbidity between referral and consultation. Studies of TTTS should acknowledge this subgroup and circumstances leading to lack of treatment.
Spin‐inversion mechanisms in the reactions of transition metal cations (Sc+, Ti+, V+, Cr+, Mn+, Fe+, Co+, Ni+, and Cu+) with OCS in the gas phase: A perspective from automated reaction path search calculations
Authors: Nakatomi Taiki , Koido Shoichi , Watabe Yuya , Takayanagi Toshiyuki
Published: January 2019

The mechanisms including spin‐inversion have been systematically studied for the M+ + OCS → MS+ + CO/MO+ + CS (M denotes a transition metal from Sc to Cu) ion‐molecule reactions using the automated reaction path search method. We used the lowest mixed‐spin potential energy surface obtained from the diagonalization of the spin‐coupled Hamiltonian matrix, whose diagonal elements are taken to be the lowest two spin states. This scheme can effectively locate approximate minimum energy crossing points between the two potential energy surfaces with different spin multiplicities. The spin‐orbit couplings at spin‐inversion points have been calculated to understand the efficiencies of nonadiabatic transitions. The obtained reaction pathways and the calculated spin‐orbit couplings are employed to interpret previous experimental studies.
Spatial distribution mapping of molecules in the grains of different rice landraces, using desorption electrospray ionization mass spectrometry
Authors: Suganya Arunan , Deb Debal , Pradeep Thalappil
Published: January 2019

Rationale

Documentation of the metabolite profiles of rice landraces is essential as most of them have been lost due to the conventional practices of cultivation. Therefore, application of mass spectrometry imaging (MSI) will be an appropriate analytical platform for molecular profiling, as it can provide a detailed understanding of the site‐specific localization patterns of biomolecules, and the cues concerning metabolic pathways in organisms.

Methods

Desorption electrospray ionization mass spectrometry (DESI‐MS) is a relatively non‐destructive analytical technique for surface sampling in natural conditions. Here, we report the spatial distribution of diverse molecules in the grains of different rice landraces of India using DESI‐MSI. Molecules were identified by ESI‐MS and tandem MS analysis of rice extracts. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) were used for the elemental mapping on the rice grains.

Results

DESI‐MSI showed a uniform distribution of choline (m/z 104.1), sucrose in the form of its sodium (m/z 365.1) and potassium (m/z 381.0) adducts, linoleic acid (m/z 279.2), 13‐HODE‐9‐HODE (m/z 295.2), unidentified molecules with m/z 535.3, 559.5, and 561.5 and isoschaftoside (m/z 563.1) in the endosperm of rice grains. Gluconic acid (m/z 195.0) and signalling phospholipid intermediate molecules were localized in the embryo whereas oryzanol A (m/z 601.5) and oryzanol C (m/z 615.5) had a restricted localization in the bran region of the grain. SEM‐EDS mapping showed the localization of potassium and phosphorus along the bran and embryo.

Conclusions

DESI‐MSI revealed the distribution of lipids and sugar molecules in the specific regions of the rice grains. Thus, molecules unique to some rice varieties were identified with this analytical platform. Mass spectrometry imaging of rice along with the elemental mapping by SEM‐EDS will be of use in understanding the localization pattern of certain molecules in the context of metals present in the grain.
Early informal STEM experiences and STEM identity: The importance of talking science
Authors: Dou Remy , Hazari Zahra , Dabney Katherine , Sonnert Gerhard , Sadler Philip
Published: January 2019

In this paper, we examine the relationship between participants’ childhood science, technology, engineering, and mathematics (STEM) related experiences, their STEM identity (i.e., seeing oneself as a STEM person), and their college career intentions. Whereas some evidence supports the importance of childhood (i.e., K‐4) informal STEM education experiences, like participating in science camps, existing research does not adequately address their relationship to STEM career intention later in life. Grounding our work in identity research, we tested the predictive power of STEM identity on career intention (N = 15,847). We found that for every one‐point higher on our STEM identity scale, participants’ odds of choosing a STEM career in college increased by 85%. We then tested whether a variety of childhood informal experiences predicted participants’ STEM identity. While controlling for home environment, gender, and other relevant factors, only talking with friends and family about science, and consuming science and science‐fiction media (i.e., books and television) were predictive of STEM identity in college.
CEO's age and the performance of closely held firms
Authors: Belenzon Sharon , Shamshur Anastasiya , Zarutskie Rebecca
Published: January 2019

Research Summary

Using detailed ownership and financial information from a large sample of owner‐managed private firms in three Western European countries, this paper examines the relationship between CEO's age and firm's performance. Tracking firms over time, we find that as a CEO ages, the firm experiences lower investment, lower sales growth, and lower profitability, but also higher probability of survival, suggesting a trade‐off between the managerial approaches of younger and older CEOs. These results are stronger in industries more reliant on human capital, such as service and creative industries. Our evidence also suggests that regional financial development moderates the relationship between a CEO's age and a firm's performance by facilitating the reallocation of assets from firms owned by older CEOs to firms owned by younger CEOs.

Managerial Summary

How do management styles change as CEOs grow older? Using a large firm‐level dataset, we examine the behavior and performance of firms with CEOs of different ages. We find that as a CEO grows older, firm investment, growth, and profitability decline, but probability of survival increases. The results are stronger in industries where human capital and creativity are more important. Regional financial development moderates the age–performance relationship by facilitating reallocation of assets from firms with old CEOs to firms with younger CEOs. Our findings suggest that management styles change with age, as older CEOs tend to emphasize survival at the expense of higher profits and faster growth.
How much do top management teams matter in founder‐led firms?
Authors: Hendricks Bradley , Howell Travis , Bingham Christopher
Published: January 2019

Research Summary

As firms mature, their founders are often replaced with seasoned executives. When founders are retained, the surrounding top management team (TMT) members are viewed as critical resources in helping compensate for the founder's managerial deficiencies. Surprisingly, however, little is known about how TMT members affect a founder‐led firm's performance later in a firm's life. Using novel methods and a sample of over 2,000 firms, we address this gap. We find that although team structure has a significant impact on the performance of nonfounder‐led firms (consistent with past literature), it has little to no effect on the operating performance of founder‐led firms, suggesting that founder chief executive officers (CEOs) may exert too much control. Thus, the irony is that founders are retained to propel progress but their very retention may prevent progress. Taken together, our findings add to the entrepreneurship, team, and research methods literatures.

Managerial Summary

Although founders have the entrepreneurial skills to successfully grow a startup, they generally lack the managerial skills required to lead a large, public firm. As a result, many founder CEOs are replaced before a firm goes public. When founders do stay as CEO, the prevailing belief is that they require a strong TMT to help compensate for the founder's managerial deficiencies. However, given founders' desire to retain control, there is a question of whether they will rely on that team, or if they will simply continue to follow their own intuition. We find evidence that founder CEOs are much less likely to listen to and benefit from their teams relative to nonfounder CEOs.
The October 2017 red sun phenomenon over the UK
Authors: Moore David P.
Published: January 2019

On 16 October 2017 ex‐hurricane Ophelia brought strong winds to Ireland and caused extensive damage. Over Wales, England and parts of Scotland a weak cold front associated with the system acted as a conveyor belt, bringing a mixture of Saharan dust and biomass burning smoke from Portugal and Spain and, for a time, turning the sky a muddy brown/orange colour and the Sun bright red. This analysis uses Copernicus Atmospheric Monitoring Service (CAMS) data to determine the fractionation of different aerosol types within the event and provide a comprehensive analysis for different cities across the UK. It also presents observations from the IASI satellite instrument of another pollutant, carbon monoxide, the concentration of which was greatly enhanced over Europe after the fire events.
High resolution satellite observations give new view of UK air quality
Authors: Pope Richard J. , Graham Ailish M. , Chipperfield Martyn P. , Veefkind J. Pepijn
Published: January 2019

New state‐of‐the‐art satellite measurements of tropospheric column NO2 from the TROPOMI instrument on‐board Sentinel‐5 Precursor (S5P), launched in October 2017, allow for an unprecedented high resolution (sub‐10km) assessment of UK air quality (AQ) from space. We present the first results from TROPOMI and compare them with its predecessor, the Ozone Monitoring Instrument (OMI), to quantify previously unresolved UK pollution hotspots (e.g. Bristol, Southampton and Liverpool). The TROPOMI tropospheric column NO2 data represents a powerful new tool to quantify UK AQ, evaluate atmospheric composition models and potentially derive new emission inventories from space.
Adsorption of Cd and Ni from water by graphene oxide and graphene oxide–almond shell composite
Authors: Yari Moghaddam Nasibeh , Lorestani Bahareh , Cheraghi Mehrdad , Jamehbozorgi Saeed
Published: January 2019

The present study describes the preparation and capability of the graphene oxide/almond shell (GO@AS) composite by a freeze‐drying method. The composite showed excellent ability to uptake nickel and cadmium ions, which were characterized by Fourier transform infrared spectrum and scanning electron microscopy techniques. The optimized values of pH, contact time, and adsorbent doses were found to be 7.5, 30–180 min, and 0.1 g, respectively. Also, adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir and Freundlich models. The maximum sorption capacities of GO@AS calculated from Langmuir isotherm model were 121.95 mg/g for Cd (II) and 69.93 mg/g for Ni (II). A higher adsorption capacity was for Cd (II) on GO@AS.

Practitioner points

Synthesis of graphene oxide–almond shell composite.

Removal of Cd and Ni ions from water by graphene oxide–almond shell composite.

Study of isotherm adsorption models.
Downregulation by organic nitrogen of AOX1 promoter used for controlled expression of foreign genes in the yeast Pichia pastoris
Authors: Velastegui Edgar , Theron Chrispian , Berrios Julio , Fickers Patrick
Published: January 2019

Pichia pastoris is a well‐established cell factory for recombinant protein synthesis. Various optimization strategies of processes based on AOX1 promoter have been investigated, including methanol co‐feeding with glycerol or sorbitol during the induction stage. Compared with carbon sources, comparatively little research has been devoted to the effects of nitrogen sources. Several reports have described the benefits of adding casamino acids (CA) to the recombinant protein production medium, however, without considering its effects at the gene expression level. Using enhanced green fluorescent protein as a reporter protein, monitored using flow cytometry, CA was shown to downregulate AOX1 promoter induction. Despite higher growth rates, cultures containing CA exhibited slower transition to the induced state, whereas metabolite analysis revealed that methanol consumption was reduced in the presence of CA compared with its absence. The repressive effect of CA was further confirmed by analysing the synthesis of extracellular recombinant Candida antarctica lipase under control of the AOX1 promoter. These findings highlight nitrogen source selection as an important consideration for AOX1‐based protein production.
Trauma recidivism in a Canadian province: a 14-year registry review
Authors: Erdogan Mete , Kureshi Nelofar , Asbridge Mark , Green Robert S.
Published: January 2019

Objectives

To determine the rate of recurrent major trauma (i.e., trauma recidivism) using a provincial population-based trauma registry. We compared outcomes between recidivists and non-recidivists, and assessed factors associated with recidivism and mortality.

Methods

Review of all adult (>17 years) major trauma patients in Nova Scotia (2001–2015) using data from the Nova Scotia Trauma Registry. Outcomes of interest were mortality, duration of hospital stay, and in-hospital complications. Multiple regression was used to assess factors associated with recidivism and mortality.

Results

Of 9,365 major trauma patients, 2% (150/9365) were recidivists. Mean age at initial injury was 52 ± 21.5 years; 73% were male. The mortality rate for both recidivists and non-recidivists was 31%. However, after adjusting for potential confounders the likelihood of mortality was over 3 times greater for recidivists compared to non-recidivists (OR 3.67, 95% CI 2.06–6.54). Other factors associated with mortality included age, male gender, penetrating injury, Injury Severity Score, trauma team activation (TTA) and admission to the intensive care unit. The only variables associated with recidivism were age (OR 0.98, 95% CI 0.97–1.00) and TTA (OR 0.59, 95% CI 0.34–0.96).

Conclusions

This is the first provincial investigation of major trauma recidivism in Canada. While recidivism was infrequent (2%), the adjusted odds of mortality were over three times greater for recidivists. Further research is warranted to determine the effectiveness of strategies for reducing rates of major trauma recidivism such as screening and brief intervention in cases of violence or substance abuse.
A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room
Authors: Cadnum Jennifer L. , Jencson Annette L. , Gestrich Scott A. , Livingston Scott H. , Karaman Boris A. , Benner Kevin J. , Wilson Brigid M. , Donskey Curtis J.
Published: January 2019

Objective

To evaluate the efficacy of multiple ultraviolet (UV) light decontamination devices in a radiology procedure room.

Design

Laboratory evaluation.

Methods

We compared the efficacy of 8 UV decontamination devices with a 4-minute UV exposure time in reducing recovery of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and Clostridium difficile spores on steel disk carriers placed at 5 sites on a computed tomography patient table. Analysis of variance was used to compare reductions for the different devices. A spectrometer was used to obtain irradiance measurements for the devices.

Results

Four standard vertical tower low-pressure mercury devices achieved 2 log10CFU or greater reductions in VRE and MRSA and ~1 log10CFU reductions in C. difficile spores, whereas a pulsed-xenon device resulted in less reduction in the pathogens (P<.001). In comparison to the vertical tower low-pressure mercury devices, equal or greater reductions in the pathogens were achieved by 3 nonstandard low-pressure mercury devices that included either adjustable bulbs that could be oriented directly over the exam table, a robotic base allowing movement along the side of the table during operation, or 3 vertical towers operated simultaneously. The low-pressure mercury devices produced primarily UV-C light, whereas the pulsed-xenon device produced primarily UV-A and UV-B light. The time required to move the devices from the corner of the room and set up for operation varied from 18 to 59 seconds.

Conclusions

Many currently available UV devices could provide an effective and efficient adjunct to manual cleaning and disinfection in radiology procedure rooms.
A cross-sectional analysis of dietary protein intake and body composition among Chinese Americans
Authors: Popp Collin J. , Beasley Jeannette M. , Yi Stella S. , Hu Lu , Wylie-Rosett Judith
Published: January 2019

Favourable body composition has been associated with higher dietary protein intake. However, little is known regarding this relationship in a population of Chinese Americans (CHA), who have lower BMI compared with other populations. The aim of the present study was to assess the relationship between dietary protein intake, fat mass (FM) and fat-free mass (FFM) in CHA. Data were from the Chinese American Cardiovascular Health Assessment (CHA CHA) 2010–2011 (n 1707); dietary intake was assessed using an adapted and validated FFQ. Body composition was assessed using bioelectrical impedance analysis. The associations between protein intake (% energy intake) and BMI, percentage FM (FM%), percentage FFM (FFM%), FM index (FMI) and FFM index (FFMI) were examined using multiple linear regression adjusted for age, sex, physical activity, acculturation, total energy intake, sedentary time, smoking status, education, employment and income. There was a significant positive association between dietary protein and BMI (B = 0·056, 95 % CI 0·017, 0·104; P = 0·005), FM (B = 0·106, 95 % CI 0·029, 0·184; P = 0·007), FM% (B = 0·112, 95 % CI 0·031, 0·194; P = 0·007) and FMI (B = 0·045, 95 % CI 0·016, 0·073; P = 0·002). There was a significant negative association between dietary protein and FFM% (B = −0·116, 95 % CI −0·196, −0·036; P = 0·004). In conclusion, higher dietary protein intake was associated with higher adiposity; however, absolute FFM and FFMI were not associated with dietary protein intake. Future work examining the relationship between protein source (i.e. animal) and body composition is warranted in this population of CHA.
Revision of the unusual Carboniferous ophiuroidCholaster(Echinodermata) and remarks on skeletal differentiation within the Asterozoa
Authors: Blake Daniel B. , Nestell Merlynd K.
Published: January 2019

Newly discovered, relatively well-preserved specimens ofCholaster whitein. sp. (Ophiuroidea, Echinodermata) are described from a small area of extensive outcrop of the Bangor Limestone (Mississippian, Chesterian) exposed on the edge of Cedar Creek Reservoir in northern Alabama, USA. The only other known species of the genus,C.peculiarisWorthen and Miller, is based on a single specimen exposed in dorsal aspect and collected from strata of similar age from southwestern Illinois. Incomplete preservation of the singleC.peculiarisspecimen limits comparisons, but differences between the two occurrences support separation at the species level.

Skeletal remains of both asteroids and ophiuroids are first recognized from Early Ordovician sediments, and representatives of the two classes have retained plesiomorphies or converged morphologically since that time, thereby suggesting important evolutionary potentials and limitations.Cholasteris asteroid-like and unusual among ophiuroids in that the arms are comparatively broad and strap-like, and lateral ossicles are similar to asteroid adambulacrals and marginals, whereas the “vertebrae” (i.e., fused axial pair) and oral frame configurations ofC. whitein. sp. are typical of the Ophiuroidea. The oral frame ofC. peculiarisis unknown.

A poorly preserved specimen of the asteroidDelicaster? also was recovered from nearby strata associated with theC. whitein. sp.

UUID:http://zoobank.org/e0eea445-58e5-4096-80c1-a65964832ef6
The mechanical life of plants: Descartes on botany
Authors: BALDASSARRI FABRIZIO
Published: January 2019

In this article, I argue that the French philosopher René Descartes was far more involved in the study of plants than has been generally recognized. We know that he did not include a botanical section in his natural philosophy, and sometimes he differentiated between plants and living bodies. His position was, moreover, characterized by a methodological rejection of the catalogues of plants. However, this paper reveals a significant trend in Descartes's naturalistic pursuits, starting from the end of 1637, whereby he became increasingly interested in plants. I explore this shift by examining both Descartes's correspondence and several notes contained in theExcerpta anatomica. Grounded in direct observations, Descartes's work on vegetation provides a modest, though not unimportant, contribution to a natural-philosophical approach to the vegetal realm. This had a direct bearing on his lifelong ambition to explain the nature of living bodies and also fuelled the emergence of botany as a modern science.
Francis Bacon's doctrine of idols: a diagnosis of ‘universal madness’
Authors: WEEKS S.V.
Published: January 2019

The doctrine of idols is one of the most famous aspects of Bacon's thought. Yet his claim that the idols lead to madness has gone almost entirely unnoticed. This paper argues that Bacon's theory of idols underlies his diagnosis of the contemporary condition as one of ‘universal madness’. In contrast to interpretations that locate his doctrine of error and recovery within the biblical narrative of the Fall, the present analysis focuses on the material and cultural sources of the mind's tendency towards error. It explains the idols in terms of Bacon's materialist psychology and his exposé of the debilitating effects of language and traditional learning. In so doing, it highlights the truly radical nature of the idols. For Bacon, the first step towards sanity was to alert people to the prevailing madness. The doctrine of idols was intended as a wake-up call, preparing the way for a remedy in the form of his new method of inquiry. The paper concludes by indicating how Bacon's method aimed to treat ‘universal madness’, and it suggests that his diagnosis influenced John Locke.
Presidents’ Sex and Popularity: Baselines, Dynamics and Policy Performance
Authors: Carlin Ryan E , Carreras Miguel , Love Gregory J
Published: January 2019

Public approval is a crucial source of executive power in presidential systems. Does the public support female and male presidents similarly? Combining insights from gender and politics research with psychological evidence, this study theorizes sex-based differentials in popularity based on more general expectations linking gender stereotypes to diverging performance evaluations. Using quarterly analyses of eighteen Latin American democracies, South Korea and the Philippines, the analyses compare the levels, dynamics, and policy performance of macro-approval for male and female presidents. As expected, female presidents are less popular, experience exaggerated approval dynamics and their approval is more responsive to security and corruption (though not economic) outcomes. These findings have clear implications for our understandings of mass politics, political accountability and presidentialism.
La politique du salaire minimum : le rôle des partis politiques dans les pays de l'OCDE (1960–2014)
Authors: Durocher Dominic
Published: January 2019

L'enjeu politique de la fixation du salaire minimum a été relativement peu étudié en science politique. Dans cet article, nous examinons le rôle des partis politiques de gauche sur la fixation du salaire minimum. Comme prédit par la théorie des ressources du pouvoir, les partis de gauche devraient encourager l'augmentation du salaire minimum. Nous postulons toutefois que cet effet diffère selon le niveau de corporatisme. Plus particulièrement, nous pensons que l'effet des partis politiques de gauche devrait être plus faible sous des niveaux de corporatisme élevés puisque les partenaires sociaux sont davantage consultés et que les gouvernements ont tendance à leur déléguer la régulation des salaires. Nos résultats confirment ces hypothèses. Ils indiquent que le salaire minimum tend à augmenter lorsque les gouvernements sont davantage à gauche idéologiquement et que cette relation est plus forte lorsque le degré de corporatisme est faible.
Tits Buildings and K-Stability
Authors: Codogni Giulio
Published: January 2019

A polarized variety is K-stable if, for any test configuration, the Donaldson–Futaki invariant is positive. In this paper, inspired by classical geometric invariant theory, we describe the space of test configurations as a limit of a direct system of Tits buildings. We show that the Donaldson–Futaki invariant, conveniently normalized, is a continuous function on this space. We also introduce a pseudo-metric on the space of test configurations. Recall that K-stability can be enhanced by requiring that the Donaldson–Futaki invariant is positive on any admissible filtration of the co-ordinate ring. We show that admissible filtrations give rise to Cauchy sequences of test configurations with respect to the above mentioned pseudo-metric.
THE HISTORY OF AFRICAN POVERTY BY NUMBERS: EVIDENCE AND VANTAGE POINTS
Authors: JERVEN MORTEN
Published: January 2019

Poverty has a long history in Africa. Yet, the most conventional and influential history of African poverty is a very short one. As told by the World Bank, the history of poverty starts in the 1980s with the first Living Standard Measurement Study. This history of poverty by numbers is also a very narrow one. There is a disconnect between the theoretical and historical underpinnings of how academics understand and define poverty in Africa, and how it has been quantified in practice. While it is generally agreed that poverty is multidimensional and has certain time- and location-specific aspects, the shorthand definition for poverty is the dollar-per-day metric. This article reveals how particular types of knowledge about poverty have gained prominence and thus shaped the dominant interpretation of poverty in Africa. It argues that, based on other numerical evidence, the history of poverty in Africa could be radically different from the dominant interpretation today.