bluuebunny/crossref_metadata_2025 huggingface dataset:
Socially advantaged? How social affiliations influence access to valuable service professional transactions
Authors: Gubler Timothy , Cooper Ryan
Published: August 2019

Research summary

This article theorizes that social capital produced by social affiliations allows service professionals to gain access to higher‐value transactions through increased reputation for trustworthiness, which then aids them in further building reputation and engaging in entrepreneurship. Using a unique approach that pairs Utah residential real estate data with church congregation boundaries, we find that affiliations enable real estate agents to list 14% more expensive homes, and to consequently build reputation useful for future nonaffiliated transactions. We observe large reputation‐building benefits for early‐career agents, particularly for agents in low‐reputation firms. Strikingly, we find this lowers entrepreneurship entry by 6%. These results imply that social affiliations can substitute for reputation in selection, enabling professionals to build reputation, which then has important career implications.

Managerial summary

This article explores how social relationships between real estate agents and home sellers influence the value of transactions agents engage in. Sellers increasingly trust agents with whom they share a social affiliation, which allows agents to better secure high‐value listings and build reputation. This benefits agent in securing future valuable transactions with nonaffiliated clients. Using residential real estate data and geographically assigned church congregations, we find that agents list 14% more expensive homes when listing for affiliated clients, and that this builds agent reputation significantly faster than listing for nonaffiliated clients. Interestingly, we find listing for affiliated clients reduces future entrepreneurship 6%. Our study suggests that service professionals can leverage social affiliations to build reputation that helps them establish clientele and improve performance.
Seeds of change: How current structure shapes the type and timing of reorganizations
Authors: Raveendran Marlo
Published: August 2019

Research Summary

This article develops theory on how an organization's structure affects future reorganizations. I highlight that a firm's structure shapes not only the locus of decision‐making power (i.e., centralization and decentralization) but also the employees' interaction structure. I develop microlevel theory that connects the firm's structure to the interactions among its employees—for instance, its influence on the time employees spend adjusting their behavior after a reorganization. This theory predicts that some structures are more likely than others to promote a reorganization to occur sooner. I use a unique, hand‐collected data set of reorganizations in the cell‐phone manufacturing industry to test and find directional support for this theory.

Managerial Summary

I examine the effect of a firm's current structure on its corporate reorganization decisions, which are defined as the addition and/or removal of business units. I posit that the way employees are grouped into those business units may affect both the type and timing of subsequent reorganizations; the reason is that employees of similar (resp. different) backgrounds should need less (resp. more) time to achieve effective collaboration. Using data on the reorganizations of cell‐phone manufacturing firms during 1983–2008, I find directional support for the theory. This result implies that managers may need to watch closely any reorganization that shifts the firm toward more heterogeneous interaction structures—because its implementation may well require additional time.
2D Crystal–Based Fibers: Status and Challenges
Authors: Meng Si , Kong Tiantian , Ma Wujun , Wang Huide , Zhang Han
Published: August 2019

2D crystals are emerging new materials in multidisciplinary fields including condensed state physics, electronics, energy, environmental engineering, and biomedicine. To employ 2D crystals for practical applications, these nanoscale crystals need to be processed into macroscale materials, such as suspensions, fibers, films, and 3D macrostructures. Among these macromaterials, fibers are flexible, knittable, and easy to use, which can fully reflect the advantages of the structure and properties of 2D crystals. Therefore, the fabrication and application of 2D crystal–based fibers is of great importance for expanding the impact of 2D crystals. In this Review, 2D crystals that are successfully prepared are overviewed based on their composition of elements. Subsequently, methods for preparing 2D crystals, 2D crystals dispersions, and 2D crystal–based fibers are systematically introduced. Then, the applications of 2D crystal–based fibers, such as flexible electronic devices, high‐efficiency catalysis, and adsorption, are also discussed. Finally, the status‐of‐quo, perspectives, and future challenges of 2D crystal–based fibers are summarized. This Review provides directions and guidelines for developing new 2D crystal–based fibers and exploring their potentials in the fields of smart wearable devices.
Non-Lorentzian M5-brane theories from holography
Authors: Lambert N. , Lipstein A. , Richmond P.
Published: August 2019

Abstract

M-theory on AdS
7 × S
4 admits a description where the AdS
7 factor is constructed as a timelike Hopf fibration over a non-compact three dimensional complex projective space

$$ {\tilde{\mathrm{\mathbb{CP}}}}^3 $$

ℂℙ
˜

3

[1]. We consider the worldvolume theory for M5-branes at a fixed

$$ {\tilde{\mathrm{\mathbb{CP}}}}^3 $$

ℂℙ
˜

3

radius which, after reduction along the timelike fibre, is given by an Ω-deformed Yang-Mills theory with eight supercharges. Taking the radius to infinity then induces a classical RG flow. We construct the fixed point action which has an enhanced 24 supercharges and which can be understood as the (2, 0) theory of M5-branes on flat space reduced along a compact null Killing direction.
Physical exercise improves quality of life, depressive symptoms, and cognition across chronic brain disorders: a transdiagnostic systematic review and meta-analysis of randomized controlled trials
Authors: Dauwan Meenakshi , Begemann Marieke J. H. , Slot Margot I. E. , Lee Edwin H. M. , Scheltens Philip , Sommer Iris E. C.
Published: August 2019

We performed a meta-analysis to synthesize evidence on the efficacy and safety of physical exercise as an add-on therapeutic intervention for quality of life (QoL), depressive symptoms and cognition across six chronic brain disorders: Alzheimer’s disease, Huntington’s disease, multiple sclerosis, Parkinson’s disease, schizophrenia and unipolar depression. 122 studies ( = k) (n = 7231) were included. Exercise was superior to treatment as usual in improving QoL (k = 64,n = 4334, ES = 0.40,p < 0.0001), depressive symptoms (k = 60,n = 2909, ES = 0.78,p < 0.0001), the cognitive domains attention and working memory (k = 21,n = 1313, ES = 0.24,p < 0.009), executive functioning (k = 14,n = 977, ES = 0.15,p = 0.013), memory (k = 12,n = 994, ES = 0.12,p = 0.038) and psychomotor speed (k = 16,n = 896, ES = 0.23,p = 0.003). Meta-regression showed a dose–response effect for exercise time (min/week) on depressive symptoms (β = 0.007,p = 0.012). 69% of the studies that reported on safety, found no complications. Exercise is an efficacious and safe add-on therapeutic intervention showing a medium-sized effect on QoL and a large effect on mood in patients with chronic brain disorders, with a positive dose–response correlation. Exercise also improved several cognitive domains with small but significant effects.
Why employees matter in the fight against ransomware
Authors: Chung Marcus
Published: August 2019

Ransomware attacks keep coming and the stakes get higher every day. Each employee in a company, from the newest hire to the CEO, can either strengthen or weaken an organisation's security posture. For this reason, companies should help employees take precautions against the latest ransomware scams.

Ransomware attacks keep coming and each employee, from the newest hire to the CEO, can either strengthen or weaken an organisation's security posture.

Many malicious attacks can be stopped by endpoint security products and advanced threat protection solutions, but creative scammers keep finding ways to get past these defences. If a company's security programme does not empower employees to defend themselves, they will be more likely to engage in actions that threaten the security of the network, says Marcus Chung of BoldCloud.
A readiness assessment tool for GDPR compliance certification
Authors: Chatzipoulidis Aristeidis , Tsiakis Theodosios , Kargidis Theodoros
Published: August 2019

The General Data Protection Regulation (GDPR) is new legislation that governs users’ private data and applies across all member states of the European Union (EU), particularly to all organisations processing the data of EU users, wherever the organisation is geographically based. It came into force on 25 May 2018.
Einstein conjecture and resting-time statistics in the bed-load transport of monodispersed particles
Authors: Fraccarollo Luigi , Hassan Marwan A.
Published: August 2019

Sediment transport in rivers consists, at moderate discharge stage, of individual grains that undergo a series of step movements and rest periods (bed-load). Following a large number of grain trajectories in time and space is difficult and the results are affected by bias due to censorship of the time-spatial window. Therefore, the data sets available for the description of the statistics of resting-times, travel-time and lengths of the steps, are still insufficient. In this paper, an innovative experimental methodology has been designed and applied to get data representing the evolution of a bed surface and to support a robust statistical analysis of sediment transport. The methodology is based on image sequences taken of a flat bed made of well-sorted (mono-dispersed) particles. The acquired data are interpreted analytically through equations that describe the effects of grain entrainment and deposition. We show that grains’ displacement have a mean value independent of bed-load rate under low to moderate transport intensity for a given sediment type and bed-slope. Hence, we provide a strong validation of the seminal conjecture of Einstein in his theoretical statistical description of sediment transport. Finally, we describe the probability density functions of the resting-time for a few values of the sediment discharge.
Reproducibility of CO2 Absorption Method for measurement of Radiocarbon using a PARR Bomb and LSC
Authors: Vagner Irina , Varlam Carmen , Faurescu Denisa , Bogdan Diana , Faurescu Ionut
Published: August 2019

The CO2 absorption and liquid scintillation counting (LSC) are methods used in radioactivity monitoring programs of nuclear facilities for 14C measurements due to high number of samples and relatively high expected level of 14C concentration. The paper describes the chemical sample preparation applied to a quality control material (IAEA-C3 Cellulose), in order to evaluate the reproducibility of CO2 absorption method for this type of material. Consequently, in the experiments we used two home-made scintillation cocktails, containing two amines, 2-methoxyethylamine (MEA) and 3-methoxypropyl amine (MPA), which detained CO2 as carbamates. Due to the fact that the material used in the dedicated experiments is cellulose (contained in all vegetable materials), the method can be considered as appropriate for 14C determination from biological and vegetable materials.
Anti-Ascaris suumimmunoglobulin Y as a novel biotechnological tool for the diagnosis of human ascariasis
Authors: Lopes C.A. , de Faria L.S. , de Sousa J.E.N. , Borges I.P. , Ribeiro R.P. , Bueno L.L. , Rodrigues Ávila V.M. , Ferreira Júnior Á. , Costa-Cruz J.M.
Published: August 2019

Human ascariasis is a neglected tropical disease of great relevance to public health and is considered the most frequent helminthiasis in poor regions. Accurately diagnosing this parasite has been challenging due to limitations of current diagnostic methods. Immunoglobulin Y (IgY) technology is a very effective alternative for the production of highly specific and profitable antibodies. This study aimed to produce and apply anti-Ascaris suumIgY antibodies in the immunodiagnosis of human ascariasis. Five immunizations comprising total saline extract fromA. suumadult life forms were given at 14-day intervals toGallus gallus domesticushens of the Isa Brown line. Eggs and blood samples were collected weekly and fortnightly, respectively, to monitor the production of antibodies. The specificity of antibodies was confirmed by dot-blot, kinetic enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence antibody tests. The application for disease diagnosis was performed through the detection of immune complexes in human serum samples by sandwich ELISA. Peaks of IgY anti-A. suumproduction occurred at weeks 6 and 8. IgY showed high avidity levels after the second dose of immunization, ranging from 64% to 93%, with a mean avidity index of 78.30%. Purified IgY recognized 12 bands of proteins fromA. suumsaline extract. Eggs, the uterine portion and cuticles ofA. suumfemale adult are reactive in immunofluorescence. The detection of immune complexes showed diagnostic values of 80% sensitivity and 90% specificity. In conclusion, specific IgY have been shown to be a potential immunodiagnostic tool with promising future applications in human ascariasis.
Effects of habitat fragmentation on the bats of Kakamega Forest, western Kenya
Authors: Webala Paul W. , Mwaura Jeremiah , Mware Joseph M. , Ndiritu George G. , Patterson Bruce D.
Published: August 2019

Habitat loss and fragmentation are major threats to biodiversity worldwide, and little is known about their effects on bats in Africa. We investigated effects of forest fragmentation on bat assemblages at Kakamega Forest, western Kenya, examining captures at edge and interior locations in three forest fragments (Buyangu, 3950 ha; Kisere, 400 ha; and Malava, 100 ha) varying in forest area and human-use regimes. Basal area, canopy cover, tree density and intensity of human use were used as predictors of bat abundance and species richness. A total of 3456 mist-net hours and 3168 harp-trap hours resulted in the capture of 4983 bats representing 26 species, eight families and four foraging ensembles (frugivores, forest-interior insectivores, forest-edge insectivores and open-space insectivores). Frugivores were frequently captured at the edges of the larger, better-protected forests, but also in the interior of the smaller, more open fragment. Forest-interior insectivores and narrow-space foragers predominated in the interiors of larger fragments but avoided the smallest one. Forest specialists showed positive associations with forest variables (canopy cover, basal area and tree density), whereas frugivores responded positively to the human-use indicators. On these bases, specialist species appear to be especially vulnerable to forest fragmentation.
Sea Captains’ Views on Automated Ship Route Optimization in Ice-covered Waters
Authors: Lehtola Ville V. , Montewka Jakub , Salokannel Johanna
Published: August 2019

Safety in ice-covered polar waters can be optimised via the choice of a ship's route. This is of utmost importance for conventional as well as autonomous ships. However, the current state of the art in e-Navigation tools has left two open questions. First, what essential information are these tools still missing, and second, how they are seen by sea captains. In order to address these questions, we organised an ice navigation workshop to systematically collect routing justifications given by and waypoints planned by experienced sea captains that are particularly seasoned in ice navigation. Here, we report the outcome of that workshop. Our key findings include the reasoning and the commentary of the participants in looking for a better and safer route. These comments shed light upon both the official and unofficial code of conduct in open waters and boil down into a list of additional prerequisite information if further steps towards system autonomy are sought. Finally, the expert-planned waypoints are to be published alongside this paper to act as a benchmark for future maritime studies.
The Impact of Bridge Alerts on Navigating Officers
Authors: Maglić Lovro , Zec Damir
Published: August 2019

New navigation-related technologies and complex ships' systems are associated with a considerable amount of information and alerts on navigational bridges. Each alert triggers a process conducted by the Officer Of the Watch (OOW), which includes data collection and interpretation, decision making, as well as appropriate actions. In the case of too many alerts or poorly managed alerts, the workload of the OOW may significantly increase, and situational awareness may be compromised, increasing the risk of errors. The main goal of this research is to analyse OOW actions triggered by the alerts. The research methods included an experiment on a bridge simulator with experienced officers, a questionnaire survey and a series of interviews. The main outcomes encompass the frequency of the alerts and the number and the processing times of single actions conducted upon an alert. The results indicate that, on average, during one watch, an OOW spends 22·4 minutes conducting 64 actions triggered by 16 alerts. However, officers consider 45% of the alerts as over-prioritised and distracting at the moment of their notification.
Moderation of parenting by inhibitory control in the prediction of the common and unique variance of hyperactivity-impulsivity and inattention
Authors: Rioux Charlie , Murray Julie , Castellanos-Ryan Natalie , Séguin Jean R. , Tremblay Richard E. , Parent Sophie
Published: August 2019

This study examined whether the interaction between parenting and inhibitory control predicts hyperactivity-impulsivity and inattention in 195 children. Observation data of positive parenting were collected at 4 years, and mother reports of coercive parenting at 5 years, inhibitory control at 6 years, and hyperactivity-impulsivity/inattention at 7 years were obtained. The common and unique variance of hyperactivity-impulsivity and inattention symptoms were examined as outcomes using a bifactor model. Results indicated that positive parenting practices predicted lower levels of hyperactivity-impulsivity/inattention behaviors at age 7 only when children's inhibitory control was high. These results support the vantage sensitivity model, which posits that some individuals show an increased sensitivity to positive experiences exclusively, and support the appropriateness of a targeted prevention approach in early childhood.
Impact of the adoption of vegetative soil conservation measures on farm profit, revenue and variable cost in Darjeeling district, India
Authors: Singha Chandan
Published: August 2019

This study evaluates the effects of vegetative soil conservation practices (afforestation and/or bamboo planting) on farm profit and its components, revenue and variable cost. Since farmers self-select themselves as adopters of conservation measures, there could be a problem of selection bias in evaluating their soil conservation practices. We address the selection bias by using propensity score matching. We also check if there exists spatial spillover in adoption of vegetative conservation measures and how it affects matching. We use primary survey data from the Darjeeling district of the Eastern Himalayan region for the year 2013. Our results suggest strong spatial correlation. We find that the propensity score estimated from the spatial model provides better matches than the non-spatial model. While the results show that vegetative soil conservation can lead to significant gains in revenue, it also increases costs so that no significant gains in profit accrue to farmers.
Maladaptation and global indeterminacy
Authors: Antoci Angelo , Gori Luca , Sodini Mauro , Ticci Elisa
Published: August 2019

This article analyzes a general equilibrium growth model with overlapping generations and (production-induced) environmental degradation. Individuals react to environmental damages through mitigation or adaptation. In the former case, they reduce production and its environmental impact. In the latter, they do not tackle the causes of the problem but rather its consequences (i.e., the wellbeing loss due to environmental degradation) by increasing defensive expenditures. Despite its simplicity, the model can generate different long-term outcomes: convergence to a stationary state following a unique trajectory or local/global indeterminacy. In the last scenario, initial conditions (history) and individual expectations matter and the model can generate coordination failures and endogenous fluctuations. Results cast doubt on solutions to environmental problems relying on the role of individual behavior change or adaptation.
In Search of Perfection: Neo-spiritualism, Islamic Mysticism, and Secularism in Turkey
Authors: Soyubol Kutluğhan
Published: August 2019

This article scrutinizes a little-known venture in Turkish republican intellectual history, namely Turkish neo-spiritualism. Combining the late nineteenth- and early twentieth-century Western trend of modern spiritualism with its local dynamics and sociocultural structures, Turkish neo-spiritualism integrated the spiritual philosophies and practices of Western spiritualism with various doctrines of Islamic mysticism (Sufism). It thus sheds light on the complex ways in which a form of knowledge that was originated and disseminated from the West was not derivative in its “imported” version. The article demonstrates how modern spiritualism attained new meanings and connotations in Turkey by merging with indigenous cultural codes and memory, and how it responded to (or was shaped within) local sociopolitical as well as intellectual contexts, particularly including the top-down secularism of the early Turkish Republic.
Changes in Seismicity Pattern Due to the 2016 Kumamoto Earthquakes Identify a Highly Stressed Area on the Hinagu Fault Zone
Authors: Nanjo K.Z. , Izutsu J. , Orihara Y. , Kamogawa M. , Nagao T.
Published: August 2019

A highly stressed area where eventual ruptures have often been observed to nucleate is characterized by low b values of earthquake frequency‐size distribution. Crustal deformation due to the occurrence of large earthquakes causes stress perturbation in nearby regions, so an investigation into spatiotemporal b values can play a crucial role in the distribution of postseismic hazards after the 2016 Kumamoto earthquake sequence along the Futagawa‐Hinagu fault zone, which culminated in the magnitude 7.3 mainshock. Together with an analysis of aftershock decay p value that can be used to infer stressing history, a highly stressed area with a characteristic dimension of 10 km at the southern end of the causative faults was found. Our observation is explained by postseismic deformation due to an afterslip on the causative faults and viscoelastic relaxation model. Similar to the Kumamoto mainshock rupture, which started at a low‐b‐value area, the observed highly stressed area shows a high likelihood of future earthquake ruptures.
Weak Near‐Field Behavior of a Tsunami Earthquake: Toward Real‐Time Identification for Local Warning
Authors: Sahakian V.J. , Melgar D. , Muzli M.
Published: August 2019

Tsunami earthquakes produce some of the most devastating tsunamis. These rare events have comparatively modest magnitudes but rupture the shallowest portion of a subduction zone megathrust with exceptionally large seafloor displacements. Previous teleseismic observations found that they radiate seismic waves weakly. They should therefore not be strongly felt in the near field, but to date no near‐source seismic recordings of these events exist that confirm this. Here we analyze near‐field records of a tsunami earthquake, the 2010 M7.7 Mentawai, Indonesia event, which show remarkably weak shaking. This is strong evidence that this earthquake does indeed have a weakly radiating or inefficient source process, in spite of its large slip. Finally, we find that, when combined with near‐source Global Navigation Satellite System displacement recordings it is possible to correctly characterize tsunami earthquakes in real‐time and to provide local tsunami warning which is currently out of reach today for monitoring agencies.
Pressure and Composition Effects on Sound Velocity and Density of Core‐Forming Liquids: Implication to Core Compositions of Terrestrial Planets
Authors: Terasaki Hidenori , Rivoldini Attilio , Shimoyama Yuta , Nishida Keisuke , Urakawa Satoru , Maki Mayumi , Kurokawa Fuyuka , Takubo Yusaku , Shibazaki Yuki , Sakamaki Tatsuya , Machida Akihiko , Higo Yuji , Uesugi Kentaro , Takeuchi Akihisa , Watanuki Tetsu , Kondo Tadashi
Published: August 2019

A compositional variety of planetary cores provides insight into their core/mantle evolution and chemistry in the early solar system. To infer core composition from geophysical data, a precise knowledge of elastic properties of core‐forming materials is of prime importance. Here, we measure the sound velocity and density of liquid Fe‐Ni‐S (17 and 30 at% S) and Fe‐Ni‐Si (29 and 38 at% Si) at high pressures and report the effects of pressure and composition on these properties. Our data show that the addition of sulfur to iron substantially reduces the sound velocity of the alloy and the bulk modulus in the conditions of this study, while adding silicon to iron increases its sound velocity but has almost no effect on the bulk modulus. Based on the obtained elastic properties combined with geodesy data, S or Si content in the core is estimated to 4.6 wt% S or 10.5 wt% Si for Mercury, 9.8 wt% S or 18.3 wt% Si for the Moon, and 32.4 wt% S or 30.3 wt% Si for Mars. In these core compositions, differences in sound velocity profiles between an Fe‐Ni‐S and Fe‐Ni‐Si core in Mercury are small, whereas for Mars and the Moon, the differences are substantially larger and could be detected by upcoming seismic sounding missions to those bodies.
Venus as a Laboratory for Exoplanetary Science
Authors: Kane Stephen R. , Arney Giada , Crisp David , Domagal‐Goldman Shawn , Glaze Lori S. , Goldblatt Colin , Grinspoon David , Head James W. , Lenardic Adrian , Unterborn Cayman , Way Michael J. , Zahnle Kevin J.
Published: August 2019

The current goals of the astrobiology community are focused on developing a framework for the detection of biosignatures, or evidence thereof, on objects inside and outside of our solar system. A fundamental aspect of understanding the limits of habitable environments (surface liquid water) and detectable signatures thereof is the study of where the boundaries of such environments can occur. Such studies provide the basis for understanding how a once inhabitable planet might come to be uninhabitable. The archetype of such a planet is arguably Earth's sibling planet, Venus. Given the need to define the conditions that can rule out bio‐related signatures of exoplanets, Venus provides a unique opportunity to explore the processes that led to a completely uninhabitable environment by our current definition of the term. Here we review the current state of knowledge regarding Venus, particularly in the context of remote‐sensing techniques that are being or will be employed in the search for and characterization of exoplanets. We discuss candidate Venus analogs identified by the Kepler and TESS exoplanet missions and provide an update to exoplanet demographics that can be placed in the potential runaway greenhouse regime where Venus analogs are thought to reside. We list several major outstanding questions regarding the Venus environment and the relevance of those questions to understanding the atmospheres and interior structure of exoplanets. Finally, we outline the path toward a deeper analysis of our sibling planet and the synergy to exoplanetary science.
Simple and efficient delivery of cell-impermeable organic fluorescent probes into live cells for live-cell superresolution imaging
Authors: Zhang Meng , Li Meihua , Zhang Wenting , Han Yubing , Zhang Yu-Hui
Published: August 2019

Numerous commercial organic fluorophores with excellent optical properties are precluded from live-cell superresolution imaging due to poor cell permeability. Here, we develop a simple but effective strategy that renders cells permeable to cell-impermeable, organic fluorescent probes by using a novel peptide vehicle, PV-1. By simple coincubation with PV-1, 22 different cell-impermeable, organic fluorescent probes were efficiently delivered into live cells and specifically labeled a variety of organelles. Moreover, PV-1 can simultaneously transfer up to three different probes into live cells. By using PV-1 and these cell-impermeable fluorescent probes, we obtained multicolor, long-term, live-cell superresolution images of various organelles, which allowed us to study the dynamic interactions between them. PV-1, together with these organic fluorescent probes, will greatly broaden the applications of superresolution imaging technology in diverse live-cell studies and opens up a new avenue in the design and application of peptide vehicles.
A versatile route to fabricate single atom catalysts with high chemoselectivity and regioselectivity in hydrogenation
Authors: He Xiaohui , He Qian , Deng Yuchen , Peng Mi , Chen Hongyu , Zhang Ying , Yao Siyu , Zhang Mengtao , Xiao Dequan , Ma Ding , Ge Binghui , Ji Hongbing
Published: August 2019

Preparation of single atom catalysts (SACs) is of broad interest to materials scientists and chemists but remains a formidable challenge. Herein, we develop an efficient approach to synthesize SACs via a precursor-dilution strategy, in which metalloporphyrin (MTPP) with target metals are co-polymerized with diluents (tetraphenylporphyrin, TPP), followed by pyrolysis to N-doped porous carbon supported SACs (M1/N-C). Twenty-four different SACs, including noble metals and non-noble metals, are successfully prepared. In addition, the synthesis of a series of catalysts with different surface atom densities, bi-metallic sites, and metal aggregation states are achieved. This approach shows remarkable adjustability and generality, providing sufficient freedom to design catalysts at atomic-scale and explore the unique catalytic properties of SACs. As an example, we show that the prepared Pt1/N-C exhibits superior chemoselectivity and regioselectivity in hydrogenation. It only converts terminal alkynes to alkenes while keeping other reducible functional groups such as alkenyl, nitro group, and even internal alkyne intact.
Effect of pre-coagulation using different aluminium species on crystallization of cake layer and membrane fouling
Authors: Yu Wenzheng , Liu Mengjie , Zhang Xuejia , Graham Nigel , Qu Jiuhui
Published: August 2019

Pre-coagulation could mitigate the membrane fouling, and thus we used different Al coagulants as a pre-treatment for ultrafiltration to explore their effects on the morphology of the membrane cake layer and fouling. Parallel bench-scale tests, using three different species of Al (AlCl3, PACl15, and PACl25), with and without humic acid, were operated continuously for a long period to investigate the effects of floc aging (~13 days). Specifically, the presence of humic acid affects the cake layer by influencing the rate and extent of floc crystallization, as greater crystallization leads to greater fouling (bio-fouling was excluded in this study). The fouling rate (indicated by the trans-membrane pressure at constant flux) varied with Al species and was found to increase as follows: PACl15 < PACl25 < AlCl3. The presence of humic acid also intensify membrane flouling. The results showed that three species of Al induced different sizes of primary nanoparticles and fractal dimensions of flocs, and therefore produced cake layers with different thickness/structure. Analysis of flocs with different ages indicated a crystallization process in the cake layer. Crystallization exacerbate membrane fouling by decreasing the porosity of the cake layer, and the situation became severe in the presence of humic acid.
A Cell Density-Dependent Reporter in the Drosophila S2 Cells
Authors: Romine Matthew L. , Li Mo , Liu Kevin Jiayang , Patel Sapna K. , Nelson Julie G. , Shen Ping , Cai Haini N.
Published: August 2019

Cell density regulates many aspects of cell properties and behaviors including metabolism, growth, cytoskeletal structure and locomotion. Importantly, the responses by cultured cells to density signals also uncover key mechanisms that govern animal development and diseases in vivo. Here we characterized a density-responsive reporter system in transgenic Drosophila S2 cells. We show that the reporter genes are strongly induced in a cell density-dependent and reporter-independent fashion. The rapid and reversible induction occurs at the level of mRNA accumulation. We show that multiple DNA elements within the transgene sequences, including a metal response element from the metallothionein gene, contribute to the reporter induction. The reporter induction correlates with changes in multiple cell density and growth regulatory pathways including hypoxia, apoptosis, cell cycle and cytoskeletal organization. Potential applications of such a density-responsive reporter will be discussed.
Assessment of risk to hoary squash bees (Peponapis pruinosa) and other ground-nesting bees from systemic insecticides in agricultural soil
Authors: Willis Chan D. Susan , Prosser Ryan S. , Rodríguez-Gil Jose L. , Raine Nigel E.
Published: August 2019

Using the hoary squash bee (Peponapis pruinosa) as a model, we provide the first probabilistic risk assessment of exposure to systemic insecticides in soil for ground-nesting bees. To assess risk in acute and chronic exposure scenarios inCucurbitaand field crops, concentrations of clothianidin, thiamethoxam and imidacloprid (neonicotinoids) and chlorantraniliprole (anthranilic diamide) in cropped soil were plotted to produce an environmental exposure distribution for each insecticide. The probability of exceedance of several exposure endpoints (LC50s) was compared to an acceptable risk threshold (5%). InCucurbitacrops, under acute exposure, risk to hoary squash bees was below 5% for honey bee LC50s for all residues evaluated but exceeded 5% for clothianidin and imidacloprid using a solitary bee LC50. ForCucurbitacrops in the chronic exposure scenario, exposure risks for clothianidin and imidacloprid exceeded 5% for all endpoints, and exposure risk for chlorantraniliprole was below 5% for all endpoints. In field crops, risk to ground-nesting bees was high from clothianidin in all exposure scenarios and high for thiamethoxam and imidacloprid under chronic exposure scenarios. Risk assessments for ground-nesting bees should include exposure impacts from pesticides in soil and could use the hoary squash bee as an ecotoxicology model.
White Light Emission from a Simple Mixture of Fluorescent Organic Compounds
Authors: Muhamad Sarih Norfatirah , Myers Peter , Slater Anna , Slater Ben , Abdullah Zanariah , Tajuddin Hairul Anuar , Maher Simon
Published: August 2019

Three fluorescent organic compounds—furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)—are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.
Flux balance analysis with or without molecular crowding fails to predict two thirds of experimentally observed epistasis in yeast
Authors: Alzoubi Deya , Desouki Abdelmoneim Amer , Lercher Martin J.
Published: August 2019

Computational predictions of double gene knockout effects by flux balance analysis (FBA) have been used to characterized genome-wide patterns of epistasis in microorganisms. However, it is unclear how in silico predictions are related to in vivo epistasis, as FBA predicted only a minority of experimentally observed genetic interactions between non-essential metabolic genes in yeast. Here, we perform a detailed comparison of yeast experimental epistasis data to predictions generated with different constraint-based metabolic modeling algorithms. The tested methods comprise standard FBA; a variant of MOMA, which was specifically designed to predict fitness effects of non-essential gene knockouts; and two alternative implementations of FBA with macro-molecular crowding, which account approximately for enzyme kinetics. The number of interactions uniquely predicted by one method is typically larger than its overlap with any alternative method. Only 20% of negative and 10% of positive interactions jointly predicted by all methods are confirmed by the experimental data; almost all unique predictions appear to be false. More than two thirds of epistatic interactions are undetectable by any of the tested methods. The low prediction accuracies indicate that the physiology of yeast double metabolic gene knockouts is dominated by processes not captured by current constraint-based analysis methods.
In vivo muscle morphology comparison in post-stroke survivors using ultrasonography and diffusion tensor imaging
Authors: Körting Clara , Schlippe Marius , Petersson Sven , Pennati Gaia Valentina , Tarassova Olga , Arndt Anton , Finni Taija , Zhao Kangqiao , Wang Ruoli
Published: August 2019

Skeletal muscle architecture significantly influences the performance capacity of a muscle. A DTI-based method has been recently considered as a new reference standard to validate measurement of muscle structure in vivo. This study sought to quantify muscle architecture parameters such as fascicle length (FL), pennation angle (PA) and muscle thickness (tm) in post-stroke patients using diffusion tensor imaging (DTI) and to quantitatively compare the differences with 2D ultrasonography (US) and DTI. Muscle fascicles were reconstructed to examine the anatomy of the medial gastrocnemius, posterior soleus and tibialis anterior in seven stroke survivors using US- and DTI-based techniques, respectively. By aligning the US and DTI coordinate system, DTI reconstructed muscle fascicles at the same scanning plane of the US data can be identified. The architecture parameters estimated based on two imaging modalities were further compared. Significant differences were observed for PA and tm between two methods. Although mean FL was not significantly different, there were considerable intra-individual differences in FL and PA. On the individual level, parameters measured by US agreed poorly with those from DTI in both deep and superficial muscles. The significant differences in muscle parameters we observed suggested that the DTI-based method seems to be a better method to quantify muscle architecture parameters which can provide important information for treatment planning and to personalize a computational muscle model.
The effect of silver oxidation on the photocatalytic activity of Ag/ZnO hybrid plasmonic/metal-oxide nanostructures under visible light and in the dark
Authors: Ziashahabi Azin , Prato Mirko , Dang Zhiya , Poursalehi Reza , Naseri Naimeh
Published: August 2019

A new synergetic hybrid Ag/ZnO nanostructure was fabricated which is able to cause photocatalytic degradation (in high yields) of methylene blue under visible light as well as in the dark. In this nanostructure, ZnO was synthesized using the arc discharge method in water and was coupled with Ag via a chemical reduction method. X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy results confirmed the existence of defects in ZnO in the hybrid nanostructures; these defects act as electron traps and inhibit the recombination of electron-hole pairs. The absorption edge of the hybrid nanostructure shifts toward the visible region of the spectrum due to a combination of the Ag plasmonic effect and the defects in ZnO. Band-edge tuning causes effective visible light absorption and enhances the dye degradation efficiency of Ag/ZnO nanostructures. Silver oxidation in the hetero-structure changed the metal-semiconductor interface and suppressed the plasmonic enhancement. Nevertheless, the synthesized Ag/ZnO decomposed methylene blue in visible light, and the silver oxidation only affected the catalytic activity in the dark. This work provides insight into the design of a new and durable plasmonic-metal oxide nanocomposite with efficient dye degradation even without light illumination.
A Kriging-Based Approach to Autonomous Experimentation with Applications to X-Ray Scattering
Authors: Noack Marcus M. , Yager Kevin G. , Fukuto Masafumi , Doerk Gregory S. , Li Ruipeng , Sethian James A.
Published: August 2019

Modern scientific instruments are acquiring data at ever-increasing rates, leading to an exponential increase in the size of data sets. Taking full advantage of these acquisition rates will require corresponding advancements in the speed and efficiency of data analytics and experimental control. A significant step forward would come from automatic decision-making methods that enable scientific instruments to autonomously explore scientific problems—that is, to intelligently explore parameter spaces without human intervention, selecting high-value measurements to perform based on the continually growing experimental data set. Here, we develop such an autonomous decision-making algorithm that is physics-agnostic, generalizable, and operates in an abstract multi-dimensional parameter space. Our approach relies on constructing a surrogate model that fits and interpolates the available experimental data, and is continuously refined as more data is gathered. The distribution and correlation of the data is used to generate a corresponding uncertainty across the surrogate model. By suggesting follow-up measurements in regions of greatest uncertainty, the algorithm maximally increases knowledge with each added measurement. This procedure is applied repeatedly, with the algorithm iteratively reducing model error and thus efficiently sampling the parameter space with each new measurement that it requests. We validate the method using synthetic data, demonstrating that it converges to faithful replica of test functions more rapidly than competing methods, and demonstrate the viability of the approach in an experimental context by using it to direct autonomous small-angle (SAXS) and grazing-incidence small-angle (GISAXS) x-ray scattering experiments.
Annual variation in predation risk is related to the direction of selection for brain size in the wild
Authors: Jaatinen Kim , Møller Anders P. , Öst Markus
Published: August 2019

The direction of predator-mediated selection on brain size is debated. However, the speed and the accuracy of performing a task cannot be simultaneously maximized. Large-brained individuals may be predisposed to accurate but slow decision-making, beneficial under high predation risk, but costly under low risk. This creates the possibility of temporally fluctuating selection on brain size depending on overall predation risk. We test this idea in nesting wild eider females (Somateria mollissima), in which head volume is tightly linked to brain mass (r2 = 0.73). We determined how female relative head volume relates to survival, and characterized the seasonal timing of predation. Previous work suggests that relatively large-brained and small-brained females make slow versus fast nest-site decisions, respectively, and that predation events occur seasonally earlier when predation is severe. Large-brained, late-breeding females may therefore have higher survival during high-predation years, but lower survival during safe years, assuming that predation disproportionately affects late breeders in such years. Relatively large-headed females outsurvived smaller-headed females during dangerous years, whereas the opposite was true in safer years. Predation events occurred relatively later during safe years. Fluctuations in the direction of survival selection on relative brain size may therefore arise due to brain-size dependent breeding phenology.
Year-round individual specialization in the feeding ecology of a long-lived seabird
Authors: Zango Laura , Reyes-González José Manuel , Militão Teresa , Zajková Zuzana , Álvarez-Alonso Eduardo , Ramos Raül , González-Solís Jacob
Published: August 2019

Many generalist species are composed of individuals varying in the size of their realized niches within a population. To understand the underlying causes and implications of this phenomenon, repeated samplings on the same individuals subjected to different environmental conditions are needed. Here, we studied individual specialization of feeding strategies in breeding and non-breeding grounds of Cory’s shearwaters (Calonectris borealis) for 2–8 years, and its relationship with fitness. Individuals were relatively flexible in non-breeding destinations, but specialized in diet, habitat use and daily activity across years. Daily activity was also consistent throughout the year for the same individual, suggesting that it is driven by individual constraints, whereas individual diet and habitat use changed between breeding and non-breeding grounds, indicating that these specializations may be learned at each area. Moreover, individuals that were intermediate specialized in their diet tended to show higher breeding success than those with weakly and highly specialized diets, suggesting stabilizing selection. Overall, this study suggests that the development of individual specialization is more flexible than previously thought, i.e. it emerges under specific environmental conditions and can develop differently when environmental conditions vary. However, once established, individual specialization may compromise the ability of individuals to cope with environmental stochasticity.
Author Correction: Social and Physiological Context can Affect the Meaning of Physiological Synchrony
Authors: Danyluck Chad , Page-Gould Elizabeth
Published: August 2019

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Ivor Lewis esophagectomy patients are particularly vulnerable to respiratory impairment - a comparison to major lung resection
Authors: Reichert Martin , Schistek Magdalena , Uhle Florian , Koch Christian , Bodner Johannes , Hecker Matthias , Hörbelt Rüdiger , Grau Veronika , Padberg Winfried , Weigand Markus A. , Hecker Andreas
Published: August 2019

Pulmonary complications and a poor clinical outcome are common in response to transthoracic esophagectomy, but their etiology is not well understood. Clinical observation suggests that patients undergoing pulmonary resection, a surgical intervention with similarities to the thoracic part of esophagectomy, fare much better, but this has not been investigated in detail. A retrospective single-center analysis of 181 consecutive patients after right-sided thoracotomy for either Ivor Lewis esophagectomy (n = 83) or major pulmonary resection (n = 98) was performed. An oxygenation index <300 mm Hg was used to indicate respiratory impairment. When starting surgery, respiratory impairment was seen more frequently in patients undergoing major pulmonary resection compared to esophagectomy patients (p = 0.009). On postoperative days one to ten, however, esophagectomy caused higher rates of respiratory impairment (p < 0.05) resulting in a higher cumulative incidence of postoperative respiratory impairment for patients after esophagectomy (p < 0.001). Accordingly, esophagectomy patients were characterized by longer ventilation times (p < 0.0001), intensive care unit and total postoperative hospital stays (both p < 0.0001). In conclusion, the postoperative clinical course including respiratory impairment after Ivor Lewis esophagectomy is significantly worse than that after major pulmonary resection. A detailed investigation of the underlying causes is required to improve the outcome of esophagectomy.