bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the role of hydraulic conductivity on the contribution of the hyporheic zone to in‐stream nitrogen uptake
Authors: Mendoza‐Lera Clara , Ribot Miquel , Foulquier Arnaud , Martí Eugènia , Bonnineau Chloé , Breil Pascal , Datry Thibault
Published: July 2019

Nitrogen uptake (N‐uptake) within the hyporheic zone provides key ecological services, such as nutrient removal, of stream ecosystems. We hypothesize that the hydraulic conductivity (Kf) of the hyporheic sediments governs nutrient uptake rates through effects on the (a) surface and subsurface flow (i.e., hyporheic flow) and (b) hyporheic N‐uptake. Here, we worked at two hierarchical spatial scales (reach and hyporheic scale) to disentangle the role of Kf on N‐uptake. At the reach scale, we performed coinjected N‐NH4+ and Cl– additions in six reaches with contrasting reach Kf (10−1–10−5 m/s) and simultaneously determined (a) in‐stream N‐uptake (hyporheic+benthic N‐uptake) and (b) hyporheic flow, and (c) N‐uptake and microbial community abundance at the hyporheic scale. Results suggest that Kf determines the contribution of the hyporheic zone to hydrological exchange but that its role varies between scales to determine in‐stream N‐uptake. At the reach scale, Kf variability seems to determine the extent at which the hyporheic zone contributes to hyporheic flow and, thus, to N‐uptake velocity. At the hyporheic scale, Kf seems to indirectly determine hyporheic N‐uptake through the proportion of surface water that enters the hyporheic zone (i.e., relative connectivity) and the abundance of the microbial community. These results suggest an interplay between Kf at both scales and its spatial heterogeneity, which will ultimately drive in‐stream N‐uptake at reach scale. In this sense, we found that Kf can be considered as a unifying variable for stream biogeochemical processes and as an important variable to derive the contribution of hyporheic zone to in‐stream nutrient removal capacity.
Enhanced activity of soil nutrient‐releasing enzymes after plant invasion: a meta‐analysis
Authors: Zhou Yong , Staver A. Carla
Published: July 2019

Plant invasion can significantly alter soil nutrient cycling of ecosystems. How these changes are linked to soil enzyme activities is still unknown, however, even though these are proximate agents of organic matter decomposition and nutrient release. We performed a meta‐analysis of 60 case studies examining responses of 10 unique soil enzymes to plant invasion, and tested whether invaded soils differed in their enzyme activities from uninvaded soils. We also examined whether increases in soil nutrient‐releasing enzyme activity were paralleled by enhanced soil nutrient availability after plant invasion. Overall, we found that plant invasion had significant impacts on the activities of seven types of soil enzymes. Plant invasion had inconsistent impacts on C‐decomposing enzymes, but invaded sites had significantly higher activities of soil enzymes related to N‐ and P‐release than noninvaded sites. Increases in nutrient‐releasing enzyme activity after plant invasion ranged from +23% to +69%, which potentially results in a linear increase of soil nutrient availability in response to enhanced enzyme activities. Invaded soils also had higher nutrient stocks and soil microbial biomass than uninvaded soils. Our results suggest that enhanced activity of soil nutrient‐releasing enzymes after plant invasion may accelerate nutrient cycling, potentially creating a nutrient‐rich soil environment that benefits invaders and promotes their persistence, as invasive plants often appear to be more resource‐demanding and competitive than native species.
Facile Solution Processing of Stable MXene Dispersions towards Conductive Composite Fibers
Authors: Seyedin Shayan , Zhang Jizhen , Usman Ken Aldren S. , Qin Si , Glushenkov Alexey M. , Yanza Elliard Roswell S. , Jones Robert T. , Razal Joselito M.
Published: July 2019

2D transition metal carbides and nitrides called “MXene” are recent exciting additions to the 2D nanomaterials family. The high electrical conductivity, specific capacitance, and hydrophilic nature of MXenes rival many other 2D nanosheets and have made MXenes excellent candidates for diverse applications including energy storage, electromagnetic shielding, water purification, and photocatalysis. However, MXene nanosheets degrade relatively quickly in the presence of water and oxygen, imposing great processing challenges for various applications. Here, a facile solvent exchange (SE) processing route is introduced to produce nonoxidized and highly delaminated Ti3C2Tx MXene dispersions. A wide range of organic solvents including methanol, ethanol, isopropanol, butanol, acetone, dimethylformamide, dimethyl sulfoxide, chloroform, dichloromethane, toluene, and n‐hexane is used. Compared to known processing approaches, the SE approach is straightforward, sonication‐free, and highly versatile as multiple solvent transfers can be carried out in sequence to yield MXene in a wide range of solvents. Conductive MXene polymer composite fibers are achieved by using MXene processed via the solvent exchange (SE) approach, while the traditional redispersion approach has proven ineffective for fiber processing. This study offers a new processing route for the development of novel MXene‐based architectures, devices, and applications.
Reflection of neuroblastoma intratumor heterogeneity in the new OHC‐NB1 disease model
Authors: Thole Theresa M. , Toedling Joern , Sprüssel Annika , Pfeil Sebastian , Savelyeva Larissa , Capper David , Messerschmidt Clemens , Beule Dieter , Groeneveld‐Krentz Stefanie , Eckert Cornelia , Gambara Guido , Henssen Anton G. , Finkler Sabine , Schulte Johannes H. , Sieber Anja , Bluethgen Nils , Regenbrecht Christian R. A. , Künkele Annette , Lodrini Marco , Eggert Angelika , Deubzer Hedwig E.
Published: July 2019

Accurate modeling of intratumor heterogeneity presents a bottleneck against drug testing. Flexibility in a preclinical platform is also desirable to support assessment of different endpoints. We established the model system, OHC‐NB1, from a bone marrow metastasis from a patient diagnosed with MYCN‐amplified neuroblastoma and performed whole‐exome sequencing on the source metastasis and the different models and passages during model development (monolayer cell line, 3D spheroid culture and subcutaneous xenograft tumors propagated in mice). OHC‐NB1 harbors a MYCN amplification in double minutes, 1p deletion, 17q gain and diploid karyotype, which persisted in all models. A total of 80–540 single‐nucleotide variants (SNVs) was detected in each sample, and comparisons between the source metastasis and models identified 34 of 80 somatic SNVs to be propagated in the models. Clonal reconstruction using the combined copy number and SNV data revealed marked clonal heterogeneity in the originating metastasis, with four clones being reflected in the model systems. The set of OHC‐NB1 models represents 43% of somatic SNVs and 23% of the cellularity in the originating metastasis with varying clonal compositions, indicating that heterogeneity is partially preserved in our model system.
Physical function‐derived cut‐points for the diagnosis of sarcopenia and dynapenia from the Canadian longitudinal study on aging
Authors: Tessier Anne‐Julie , Wing Simon S. , Rahme Elham , Morais José A. , Chevalier Stéphanie
Published: July 2019

Background

Aging is associated with sarcopenia (low muscle mass) and dynapenia (low muscle strength) leading to disability and mortality. Widely used previous cut‐points for sarcopenia were established from dated, small, or pooled cohorts. We aimed to identify cut‐points of low strength as a determinant of impaired physical performance and cut‐points of low appendicular lean mass (ALM) as a predictor of low strength in a single, large, and contemporary cohort of community‐dwelling older adults and compare these criteria with others.

Methods

Cross‐sectional analyses were conducted on baseline data from 4725 and 4363 community‐dwelling men and women (65–86 years, 96.8% Caucasian) of the Canadian longitudinal study on aging comprehensive cohort. Physical performance was evaluated from gait speed, timed up‐and‐go, chair rise, and balance tests; a weighted‐sum score was computed using factor analysis. Strength was measured by handgrip dynamometry; ALM, by dual‐energy X‐ray absorptiometry and ALM index (ALMI; kg/m2), was calculated. Classification and regression tree analyses determined optimal sex‐specific cut‐points of ALMI predicting low strength and of strength predicting impaired physical performance (score < 1.5 SD below the sex‐specific mean).

Results

Modest associations were found between ALMI and strength and between strength and physical performance score in both sexes. ALMI was not an independent predictor of physical performance score. Cut‐points of <33.1 and <20.4 kg were found to define dynapenia in men and in women, respectively, corresponding to 21.5% and 24.0% prevalence rates. Sarcopenia cut‐points were <7.76 kg/m2 in men and <5.72 kg/m2 in women; prevalence rates of 21.7% and 13.7%. Overall, 8.3% of men and 5.5% of women had sarco‐dynapenia. Sarcopenic were older and had lower fat mass and body mass index (BMI) than non‐sarcopenic participants. While the agreement between current criteria and the updated European Working Group for Sarcopenia in Older Persons recommendations was fair, we found only slight agreement with the Foundation for the National Institute of Health sarcopenia project. Older persons identified with sarcopenia as per the Foundation for the National Institute of Health criteria (using ALM/BMI as the index) have higher BMI and fat mass compared with non‐sarcopenic and have normal ALMI as per our criteria.

Conclusions

The proposed function‐derived cut‐points established from this single, large, and contemporary Canadian cohort should be used for the identification of sarcopenia and dynapenia in Caucasian older adults. We advise on using criteria based on ALMI in the diagnosis of sarcopenia. The modest agreement between sarcopenia and dynapenia denotes potential distinct health implications justifying to study both components separately.
Sensitivity and specificity of meningeal signs in patients with meningitis
Authors: Akaishi Tetsuya , Kobayashi Junpei , Abe Michiaki , Ishizawa Kota , Nakashima Ichiro , Aoki Masashi , Ishii Tadashi
Published: July 2019

Background

Several types of physical examinations are used in the diagnosis of meningitis, including nuchal rigidity, jolt accentuation, Kernig's sign, and Brudzinski's sign. Jolt accentuation was reported to have sensitivity of nearly 100% and to be highly efficient for excluding meningitis, but more recent studies showed that a number of patients with meningitis may present negative in this test.

Methods

We systematically reviewed studies on the above‐mentioned physical examination tests and performed meta‐analysis of their diagnostic characteristics to evaluate the clinical usefulness. Nine studies, comprising a total of 599 patients with pleocytosis in the cerebrospinal fluid (CSF) and 1216 patients without CSF pleocytosis, were enrolled in the analysis.

Results

Jolt accentuation showed a decent level of odds ratio (3.62; 99% confidence interval (CI): 1.13‐11.60, P = 0.004) comparable to that in nuchal rigidity (2.52; 1.21‐5.27, P = 0.001) for the correct prediction of CSF pleocytosis among subjects with suspected meningitis. The estimated sensitivity was relatively high (40%‐60%) in nuchal rigidity or jolt accentuation tests. On the other hand, Kernig's and Brudzinski's signs exhibited relatively low sensitivity (20%‐30%). The estimated specificity was higher in Kernig's and Brudzinski's signs (85%‐95%) than in nuchal rigidity or jolt accentuation tests (65%‐75%).

Conclusion

Approximately half of the patients with meningitis may not present typical meningeal signs upon physical examination. Combining several examinations for the detection of meningeal signs may decrease the risk of misdiagnosis.
Effect of aspirin use on gastric cancer incidence and survival: A systematic review and meta‐analysis
Authors: Niikura Ryota , Hirata Yoshihiro , Hayakawa Yoku , Kawahara Takuya , Yamada Atsuo , Koike Kazuhiko
Published: July 2019

Background and Aim

A number of recent studies have been published evaluating the chemopreventive effect of aspirin against gastric cancer, and an updated meta‐analysis is required to evaluate this relationship further. This study presents a meta‐analysis of studies examining the effect of aspirin on gastric cancer incidence and death.

Methods

The PUBMED and Cochrane Central Registration of Controlled Trials databases were searched for eligible studies published up to December 2018. Pooled risk ratios for gastric cancer incidence and death in aspirin users versus nonusers were determined using fixed‐ and random‐effects models. The influence of the frequency of aspirin use, duration of aspirin use, and geographic location on gastric cancer incidence was evaluated.

Results

The meta‐analysis comprised 33 studies with a total of 1 927 971 patients. The pooled risk ratios for gastric cancer incidence in the fixed‐ and random‐effects models were 0.890 (95% confidence interval, 0.871–0.909) and 0.826 (0.740–0.922), respectively. In Asia and North America, the maximum preventive benefit of aspirin use was observed with weekly or daily use. Aspirin use was most effective for noncardiac gastric cancer. The pooled risk ratios for gastric cancer death in the fixed‐ and random‐effects models were 0.798 (0.749–0.850) and 0.894 (0.780–1.024), respectively. Significant heterogeneity was observed among studies of gastric cancer incidence but not gastric cancer death.

Conclusion

Aspirin use may reduce the risk of gastric cancer incidence and death; however, the relationship may be limited to a specific frequency and duration of aspirin use and geographic location.
The effects of age and sex on the detection of pure tones by adult CBA/CaJ mice (Mus musculus)
Authors: Kobrina Anastasiya , Dent Micheal L.
Published: July 2019

Age‐related hearing loss (ARHL) is a neurodegenerative disorder characterized by a gradual decrease in hearing sensitivity. Previous electrophysiological and behavioral studies have demonstrated that the CBA/CaJ mouse strain is an appropriate model for the late‐onset hearing loss found in humans. However, few studies have characterized hearing in these mice behaviorally using longitudinal methodologies. The goal of this research was to utilize a longitudinal design and operant conditioning procedures with positive reinforcement to construct audiograms and temporal integration functions in aging CBA/CaJ mice. In the first experiment, thresholds were collected for 8, 16, 24, 42, and 64 kHz pure tones in 30 male and 35 female CBA/CaJ mice. Similar to humans, mice had higher thresholds for high frequency tones than for low frequency pure tones across the lifespan. Female mice had better hearing acuity than males after 645 days of age. In the second experiment, temporal integration functions were constructed for 18 male and 18 female mice for 16 and 64 kHz tones varying in duration. Mice showed an increase in thresholds for tones shorter than 200 ms, reaching peak performance at shorter durations than other rodent species. Overall, CBA/CaJ mice experience ARHL for pure tones of different frequencies and durations, making them a good model for studies on hearing loss. These findings highlight the importance of using a wide range of stimuli and a longitudinal design when comparing presbycusis across different species.
Kinematic Evaluation of the GMK Sphere Implant During Gait Activities: A Dynamic Videofluoroscopy Study
Authors: Schütz Pascal , Taylor William R. , Postolka Barbara , Fucentese Sandro F. , Koch Peter P. , Freeman Michael A.R. , Pinskerova Vera , List Renate
Published: July 2019

Joint stability is a primary concern in total knee joint replacement. The GMK Sphere prosthesis was specifically designed to provide medial compartment anterior–posterior (A–P) stability, while permitting rotational freedom of the joint through a flat lateral tibial surface. The objective of this study was to establish the changes in joint kinematics introduced by the GMK Sphere prosthesis during gait activities in comparison to conventional posterior‐stabilized (PS) fixed‐bearing and ultra‐congruent (UC) mobile‐bearing geometries. The A–P translation and internal/external rotation of three cohorts, each with 10 good outcome subjects (2.9 ± 1.6 years postop), with a GMK Sphere, GMK PS or GMK UC implant were analysed throughout complete cycles of gait activities using dynamic videofluoroscopy. The GMK Sphere showed the smallest range of medial compartment A–P translation for level walking, downhill walking, and stair descent (3.6 ± 0.9 mm, 3.1 ± 0.8 mm, 3.9 ± 1.3 mm), followed by the GMK UC (5.7 ± 1.0 mm, 8.0 ± 1.7 mm, 8.7 ± 1.9 mm) and the GMK PS (10.3 ± 2.2 mm, 10.1 ± 2.6 mm, 11.6 ± 1.6 mm) geometries. The GMK Sphere exhibited the largest range of lateral compartment A–P translation (12.1 ± 2.2 mm), and the largest range of tibial internal/external rotation (13.2 ± 2.2°), both during stair descent. This study has shown that the GMK Sphere clearly restricts A–P motion of the medial condyle during gait activities while still allowing a large range of axial rotation. The additional comparison against the conventional GMK PS and UC geometries, not only demonstrates that implant geometry is a key factor in governing tibio‐femoral kinematics, but also that the geometry itself probably plays a more dominant role for joint movement than the type of gait activity. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:2337–2347, 2019
Rings whose ideals are isomorphic to trace ideals
Authors: Kobayashi Toshinori , Takahashi Ryo
Published: July 2019

Let R be a commutative noetherian ring. Lindo and Pande have recently posed the question asking when every ideal of R is isomorphic to some trace ideal of R. This paper studies this question and gives several answers. In particular, a complete answer is given in the case where R is local: it is proved in this paper that every ideal of R is isomorphic to a trace ideal if and only if R is an artinian Gorenstein ring, or a 1‐dimensional hypersurface with multiplicity at most 2, or a unique factorization domain.
Network effects, trade, and productivity
Authors: Song Tianle , Wang Susheng
Published: July 2019

We consider network effects in the monopolistically competitive model of trade developed by Melitz and Ottaviano (2008). We show that a larger network effect intensifies competition by allowing more‐productive firms to raise prices and earn higher profits, but forcing less‐productive firms to reduce prices and earn lower profits. As a result, low‐productivity firms are driven out of the market. We also show that when network effects are asymmetric, it may be difficult for firms from a country with a small network effect to compete with firms from a country with a large network effect.
Numerical recipes for elastodynamic virtual element methods with explicit time integration
Authors: Park Kyoungsoo , Chi Heng , Paulino Glaucio H.
Published: July 2019

We present a general framework to solve elastodynamic problems by means of the virtual element method (VEM) with explicit time integration. In particular, the VEM is extended to analyze nearly incompressible solids using the B‐bar method. We show that, to establish a B‐bar formulation in the VEM setting, one simply needs to modify the stability term to stabilize only the deviatoric part of the stiffness matrix, which requires no additional computational effort. Convergence of the numerical solution is addressed in relation to stability, mass lumping scheme, element size, and distortion of arbitrary elements, either convex or nonconvex. For the estimation of the critical time step, two approaches are presented, ie, the maximum eigenvalue of a system of mass and stiffness matrices and an effective element length. Computational results demonstrate that small edges on convex polygonal elements do not significantly affect the critical time step, whereas convergence of the VEM solution is observed regardless of the stability term and the element shape in both two and three dimensions. This extensive investigation provides numerical recipes for elastodynamic VEMs with explicit time integration and related problems.
Fetal aqueductal stenosis: Prenatal diagnosis and intervention
Authors: Emery Stephen P. , Narayanan Srikala , Greene Stephanie
Published: July 2019

Fetal severe central nervous system ventriculomegaly is associated with poor neurologic outcomes, usually driven by a primary malformation, deformation, or disruption of brain parenchyma. In utero shunting of excess cerebrospinal fluid (CSF) in hopes of improving neurologic outcomes was attempted in the 1980s but was abandoned due to perceived lack of effect, likely due to technological limitations of the time that precluded proper patient selection. Little progress on the antenatal management of severe ventriculomegaly has been made in the intervening decades. A multidisciplinary, evidence‐based reassessment of ventriculoamniotic shunting for isolated fetal aqueductal stenosis (FAS), a unique form of severe ventriculomegaly (supratentorial intracranial hypertension), is currently underway. An accurate diagnosis of FAS must precede in utero intervention. Magnetic resonance imaging (MRI) will be an excellent adjunct to high‐resolution prenatal ultrasound and next‐generation genetic testing to correctly diagnose FAS in a timely fashion while excluding other intracranial and extracranial anomalies. This manuscript will briefly discuss the history, current management, and future directions of the prenatal diagnosis and potential intervention for FAS.
The Photocatalytic Properties of Al‐doped ZnO Nanotubes Decorated with Cu2O Nanoparticles
Authors: Yu Fucheng , Wang Bolong , Hu Hailong , Li Haishan , Song Tianyun , Xu Boyu , He Ling , Duan Hongyan , Wang Shu
Published: July 2019

Al‐doped ZnO nanotubes (NTs) decorated with Cu2O particles (Al‐ZnO/Cu2O NTs) are prepared by a two‐step hydrothermal method, and the photocatalytic properties are examined by the degradation of methyl orange (MO) solution under simulated solar light at room temperature. Compared with the Al‐doped ZnO nanorods (Al‐ZnO NRs) and the Al‐doped ZnO NTs (Al‐ZnO NTs), the Al‐ZnO/Cu2O NTs exhibit better photocatalytic properties. The improvement of photocatalytic performance of Al‐ZnO/Cu2O NTs is attributed to both Cu2O particle decoration and NT structures. In the samples, the decoration of Cu2O particles can prolong the exciton lifetimes, and the NT structures increase specific area. Therefore, both of these two conditions contribute to improved photocatalytic efficiency.
Molecular Dynamics Simulations of Structural and Mechanical Properties in MgSiO3 Glass
Authors: Nguyen Thao T. , Nguyen Trang T. , Dinh Hinh T. , Le Vinh V.
Published: July 2019

Molecular dynamics simulations of MgSiO3 glass have been carried out to study the structural and mechanical properties under uniaxial tension. The network structure consists of SiOx and MgOy units which link to others by corner‐, edge‐, and face‐sharing bonds. The Si‐rich and Mg‐rich regions exist in MgSiO3 glass. The stress–strain curves exhibit the elastic and plastic characteristics at the various strain rates. The transformations of SiOx and MgOy units occur with increasing strain, at which the corner‐, edge‐ and face‐sharing bonds among SiOx and MgOy units change. The Si‐rich and Mg‐rich regions increase with increasing strain. Not only the Mg–O bond length is easier to stretch than the Si–O bond length but also the O–Mg–O bond angle of MgOy units is easier to vary than that of SiOx units with the strain. The porosity is analyzed via the voids. The voids gather into the clusters of voids. The radii of voids increase with increasing strain. The number of big Mg‐voids increases under the tension and these voids coalesce to form large pores. These large pores do not coalesce to cause the fractured free surfaces. The formation of shear band was observed at the strain of 0.82.
Generalized multi‐release modelling of software reliability growth models from the perspective of two types of imperfect debugging and change point
Authors: Saraf Iqra , Iqbal Javaid
Published: July 2019

Owing to release of software in multiple releases, code changes take place in software. Because of this added complexity in software, the testing team may be unable to correct the fault upon detection, leaving the actual fault to reside in the software, termed as imperfect debugging or there may be replacement of original fault by other fault, leading to error generation. Many other factors exist that affect the testing phase of software like strategies of testing, test cases, skill, efficiency, and learning of testing team. All these factors cannot be kept stable during the whole process of testing. They may change at any time moment causing the background processes to experience change, which is known as change‐point. Keeping all these critical testing environment factors under consideration, a new software reliability growth model has been proposed, which is derived from an non homogenous Poisson process (NHPP)based unified scheme for multi‐release two‐stage fault detection/observation and correction/removal software reliability models. The developed model is numerically illustrated on tandem data set for four releases.
Learn how to manage student conduct, distress involving online learning environments
Authors: McCarthy Claudine
Published: July 2019

JACKSONVILLE, FLA. — Student affairs professionals at institutions with online students — especially with multiple campuses in different states or countries — certainly face additional challenges navigating conversations about student conduct. Of course, such difficult topics are best suited to in‐person meetings, but that's usually impossible with far‐flung and online students. But there are other ways you can successfully and effectively manage student conduct cases and academic‐integrity‐related challenges involving the online classroom, according to Jennifer Toof, M.S., M.B.A., assistant director of world campus student affairs at The Pennsylvania State University. She shared her recommendations at the Association for Student Conduct Administration's annual conference.
Consider insider's view of learning from controversy
Authors: McCarthy Claudine
Published: July 2019

CLEARWATER, FLA. — As a lawyer, former U.S. solicitor general, and federal judge, and former president and chancellor of Baylor University, Ken Starr is certainly no stranger to controversy. And he's more than willing to take a direct approach to sharing his lessons learned — which is what he did when he spoke at Stetson University's National Conference on the Law & Higher Education.
Oxygen radical‐driven surface modification of polycaprolactone‐filled glass microfiber media: Probing the surface chemistry of wicking microfluidic devices
Authors: Bandara Gayan C. , Remcho Vincent T.
Published: July 2019

Cost and complexity are key factors in designing microfluidic devices for broad application. Therefore, the development of a simple, inexpensive, and easily manufactured fabrication technique that does not require expensive chemicals or instruments is necessary. We have successfully demonstrated the use of long‐lived oxygen radicals for the fabrication of membrane‐based microfluidic devices on polycaprolactone (PCL)‐filled glass microfiber (GMF) membranes. These devices may incorporate complex multidimensional (2D and 3D) microfluidic pathways on a single PCL‐filled GMF membrane. Selective exposure to oxygen radicals generated in a homebuilt oxygen plasma exposure system was employed to pattern the flow path; radical exposure of the polymer‐filled substrate altered the physical and chemical properties of the surface, affecting wettability. To the best of our knowledge, this is the only wicking microfluidic device fabrication technology that is capable of generating both 2D and 3D microfluidic pathways in a single membrane; hence, it has many potential applications. Investigations were conducted to probe the effects of oxygen radical exposure in order to provide a more quantitative understanding of the process. These findings will help expand the utility of the selective oxygen radical exposure–driven fabrication technology.
Heparin‐Mediated Growth of Self‐Organized ZnO Quasi‐Microspheres with Twinned Donut‐Like Hierarchical Structures
Authors: Li Ming , Bao Lu‐zi , Yin Zhi‐chen , Ji Xun‐ming
Published: July 2019

The insight into the rational design of nanostructure with complex functionality is a significant challenge for the advanced application of Zinc Oxide (ZnO) in various areas. Herein, heparin, as a biotemplate, was introduced to manipulate growth of ZnO nanoparticle into hierarchical structures with unusual morphology. The formation process of the morphology and microstructure of the as‐achieved products were investigated. The heparin could alter nucleation and growth rates during the primary nanocrystal formation of ZnO, and promote the formation of two‐dimensional nanoplates and subsequently self‐assembly into novel quasi‐microspherical ZnO superstructures with twinned donut‐like hemispheres. The self‐assembled quasi‐microspheres displayed well crystallinity with a hexagonal wurtzite structure and a nearly uniform size‐distribution with a value of 452.9 ± 51.2 nm. The concentrations of heparin and zinc precursor played a vital role in determining the morphology of the resulting products. The possible growth mechanism of the obtained spherical like ZnO microparticles was proposed and discussed in detail. Our results are of fundamental importance to understanding crystal growth, and beneficial to promote the potential applications of ZnO with novel hierarchical structures in nanoscale devices.
Graphene Quantum Dots for Optical Bioimaging
Authors: Lu Huiting , Li Wenjun , Dong Haifeng , Wei Menglian
Published: July 2019

Graphene quantum dots (GQDs) have shown great potential in bioimaging applications due to their excellent biocompatibility, low cytotoxicity, feasibility for surface functionalization, physiological stability, and tunable fluorescence properties. This Review first introduces the intriguing optical properties of GQDs that are suitable for biological imaging, and is followed by the GQDs' synthetic strategies. The emergent and latest development methods for tuning GQDs' optical properties are further described in detail. The recent advanced applications of GQDs in vitro, particularly in cell imaging, targeted imaging, and theranostic nanoplatform fabrication, are included. The applications of GQDs for in vivo bioimaging are also covered. Finally, the Review is concluded with the challenges and prospectives that face this nascent yet exciting field.
Programmable Liquid Adhesion on Bio‐Inspired Re‐Entrant Structures
Authors: Liu Xiaojiang , Gu Hongcheng , Ding Haibo , Du Xin , He Zhenzhu , Sun Liangdong , Liao Junlong , Xiao Pengfeng , Gu Zhongze
Published: July 2019

Surfaces combining antispreading and high adhesion can find wide applications in the manipulation of liquid droplets, generation of micropatterns and liquid enrichment. To fabricate such surfaces, almost all the traditional methods demand multi‐step processes and chemical modification. And even so, most of them cannot be applied for some liquids with extremely low surface energy. In the past decade, multiply re‐entrant structures have aroused much attention because of their universal and modification‐independent antiadhesion or antipenetration ability. Unfortunately, theories and applications about their liquid adhesion behavior are still rare. In this work, inspired by the springtail skin and gecko feet in the adhered state, it is demonstrated that programmable liquid adhesion is realized on the 3D‐printed micro doubly re‐entrant arrays. By arranging the arrays reasonably, three different Cassie adhesion behaviors can be obtained: I) no residue adhesion, II) tunable adhesion, and III) absolute adhesion. Furthermore, various arrays are designed to tune macro/micro liquid droplet manipulation, which can find applications in the transportation of liquid droplets, liquid enrichment, generation of tiny droplets, and micropatterns.
Out of time ordered quantum dissipation
Authors: Chakrabarty Bidisha , Chaudhuri Soumyadeep , Loganayagam R.
Published: July 2019

Abstract

We consider a quantum Brownian particle interacting with two harmonic baths, which is then perturbed by a cubic coupling linking the particle and the baths. This cubic coupling induces non-linear dissipation and noise terms in the influence functional/master equation of the particle. Its effect on the Out-of-Time-Ordered Correlators (OTOCs) of the particle cannot be captured by the conventional Feynman-Vernon formalism.We derive the generalised influence functional which correctly encodes the physics of OTO fluctuations, response, dissipation and decoherence. We examine an example where Markovian approximation is valid for the OTO dynamics.

If the original cubic coupling has a definite time-reversal parity, the leading order OTO influence functional is completely determined by the couplings in the usual master equation via OTO generalisation of Onsager-Casimir relations. New OTO fluctuationdissipation relations connect the non-Gaussianity of the thermal noise to the thermal jitter in the damping constant of the Brownian particle.
Creativity in Research
Authors: Ulibarri Nicola , Cravens Amanda E. , Svetina Nabergoj Anja , Kernbach Sebastian , Royalty Adam
Published: July 2019

Creativity is at the heart of successful research, yet researchers are rarely taught how to manage their creative process, and modern academic life is not structured to optimize creativity. Creativity in Research provides concrete guidance on developing creativity for anyone doing or mentoring research. Based on a curriculum developed at Stanford University's Hasso Plattner Institute of Design, this book presents key abilities that underlie creative research practice through a combination of scientific literature on creative confidence, experiential exercises, and guided reflection. By focusing attention on how research happens as well as its outputs, researchers increase their ability to address research challenges and produce the outputs they care about. Simultaneously, they may also transform their emotional relationship with their work, replacing stress and a harsh inner critic with a more open and emotionally empowered attitude.
A systematic review of tools used to screen and assess for externalising behaviour symptoms in low and middle income settings
Authors: Nezafat Maldonado B. , Chandna J. , Gladstone M.
Published: July 2019

Background.

Mental health issues, often manifested as behavioural difficulties, in children are estimated to be high in low and middle-income countries (LMIC) settings. There is a paucity of definitive data due to a lack of well-validated tools to use across settings. This review aims to provide evidence on what tools are used and which have been adapted and validated in LMIC settings.

Methods.

We performed a systematic review to identify tools used to assess or screen externalising behaviour problems in children and adolescents in LMIC and assess their cultural adaptations. We searched for studies measuring externalising behaviour in children from 0 to 19 years published up to September 2018. Articles were assessed to identify tools used and analysed using the Ecological Validity Framework.

Results.

We identified 82 articles from over 50 LMICs who had studied externalising behaviour in children. Twenty-seven tools were identified, with a predominance of studies using tools from the USA and Europe. Most studies did not describe an adaptation and evaluation process, with only one study following recommended criteria. New tools were identified which both screen and assess externalising behaviour which have not yet been utilised across settings.

Conclusions.

Although tools from the USA and Europe are often utilised to screen and assess for externalising behaviour problems in children in LMICs, the conceptual frameworks behind the use of these tools in other cultural contexts are not always carefully examined. In order to have valid data across cultures, we should aim to adapt and validate tools before use. Provision of processes to validate tools across LMIC settings would be beneficial.
Data-driven construction of a reduced-order model for supersonic boundary layer transition
Authors: Yu Ming , Huang Wei-Xi , Xu Chun-Xiao
Published: July 2019

In this study, a data-driven method for the construction of a reduced-order model (ROM) for complex flows is proposed. The method uses the proper orthogonal decomposition (POD) modes as the orthogonal basis and the dynamic mode decomposition method to obtain linear equations for the temporal evolution coefficients of the modes. This method eliminates the need for the governing equations of the flows involved, and therefore saves the effort of deriving the projected equations and proving their consistency, convergence and stability, as required by the conventional Galerkin projection method, which has been successfully applied to incompressible flows but is hard to extend to compressible flows. Using a sparsity-promoting algorithm, the dimensionality of the ROM is further reduced to a minimum. The ROMs of the natural and bypass transitions of supersonic boundary layers at $Ma=2.25$ are constructed by the proposed data-driven method. The temporal evolution of the POD modes shows good agreement with that obtained by direct numerical simulations in both cases.
Identifying the tangle of vortex tubes in homogeneous isotropic turbulence
Authors: Xiong Shiying , Yang Yue
Published: July 2019

We extend the vortex-surface field (VSF), whose isosurface is a vortex surface consisting of vortex lines, to identify vortex tubes and sheets in homogeneous isotropic turbulence. The VSF at a time instant is constructed by solving a pseudo-transport equation. This equation is convected by a given instantaneous vorticity obtained from direct numerical simulation. In each pseudo-time step, we develop a novel local optimization algorithm to minimize a hybrid VSF constraint, balancing the accuracy and smoothness of VSF solutions. This key improvement makes the numerical construction of VSFs feasible for arbitrarily complex flow fields, as a general flow diagnostic tool. In the visualization of VSF isosurfaces in decaying homogeneous isotropic turbulence, the initial curved vortex sheets first evolve into vortex tubes, and then the vortex tubes are stretched and tangled, constituting a complex network. Some vortex tubes exhibit helical geometry, which suggests the important role of vortex twisting in the generation of small-scale structures in energy cascade.
After the Axes? The Rock Art at Copt Howe, North-west England, and the Neolithic Sequence at Great Langdale
Authors: Bradley Richard , Watson Aaron , Style Peter
Published: July 2019

Within sight of the Neolithic axe quarries on the Langdale Pikes is a group of massive boulders at Copt Howe. The two largest command a direct view of the stone source where the sun sets into the mountainside at the midsummer solstice. Both are decorated by pecked motifs which resemble features of Irish passage tomb art. Small-scale excavation in 2018 showed that a rubble platform had been built at the foot of the main decorated surface and sealed two further motifs of similar character. New work has established an important sequence in Great Langdale. Recently obtained radiocarbon dates indicate that the main period of axe production was between 3800 and 3300bc, whilst Irish megalithic art is later and was made between about 3300 and 2900bc, suggesting that Copt Howe achieved its importance after axe-making had ceased or was in decline. That is consistent with an increasing emphasis on relations between northern Britain and Ireland during the Late Neolithic period. Perhaps Copt Howe itself was treated as a ‘natural’ passage tomb.
A Tractable Framework for Option Pricing with Dynamic Market Maker Inventory and Wealth
Authors: Fournier Mathieu , Jacobs Kris
Published: July 2019

We develop a tractable dynamic model of an index option market maker with limited capital. We solve for the variance risk premium and option prices as a function of the asset dynamics and market maker option holdings and wealth. The market maker absorbs end users’ positive demand and requires a more negative variance risk premium when she incurs losses. We estimate the model using returns, options, and inventory and find that it performs well, especially during the financial crisis. The restrictions imposed by nested existing reduced-form stochastic-volatility models are strongly rejected in favor of the model with a market maker.
Why microbes, not microbiomes, are better causal explanations in gut-brain research
Authors: Lynch Kate E.
Published: July 2019

Much microbiota-gut-brain research focuses on the causal role of microbiomes as a whole, rather than their component parts: microbes. Hooks et al. find these whole-community explanations inadequate; however, they do not provide suggestions for better explanations. By appealing to proportionality – a criterion that can be used to develop more appropriate causal explanations – more accurate causal claims can be made.
Microbiota-gut-brain research: A plea for an interdisciplinary approach and standardization
Authors: Andreoletti Mattia , Rescigno Maria
Published: July 2019

Hooks et al. note that microbiota-gut-brain research suffers from serious methodological flaws and interpretative issues. We suggest two corrective measures: first, taking more seriously the need of interdisciplinary work; second, interpreting some of the methodological issues as ordinary challenges of standardization, typical of emerging disciplines.
Does having highly educated adult children reduce mortality risks for parents with low educational attainment in Europe?
Authors: Sabater Albert , Graham Elspeth , Marshall Alan
Published: July 2019

It is known that the education of significant others may affect an individual's mortality. This paper extends an emerging body of research by investigating the effect of having highly educated adult children on the longevity of older parents in Europe, especially parents with low educational attainment. Using a sample of 15,015 individuals (6,620 fathers and 8,395 mothers) aged 50 and above, with 1,847 recorded deaths, over a mean follow-up period of 10.9 years from the Survey of Health, Ageing and Retirement in Europe (SHARE), we examine whether the well-established socio-economic gradient in mortality among parents is modified when their adult children have higher educational attainment than their parents. We find that having highly educated adult children is associated with reduced mortality risks for fathers and mothers with low educational attainment, compared to their counterparts whose adult children have only compulsory education. The association is stronger in early older age (ages 50–74) than in later older age (ages 75 and over). Part of the association appears to be explained by health behaviours (physical (in)activity) and health status (self-rated health). Our findings suggest that the socio-economic–mortality gradient among older parents might be better captured using an intergenerational approach that recognises the advantage of having highly educated adult children, especially for fathers and mothers with only compulsory education.
Plague – a disease of children and servants? A study of the parish records of St Peter upon Cornhill, London from 1580 to 1605
Authors: Evans Charles M. , Evans Angela E.
Published: July 2019

A study of the parish records of St Peter upon Cornhill in London from 1580 to 1605 revealed that children suffered a greater increase in mortality than adults in the plague years of 1593 and 1603, and servants accounted for the majority of deaths within the 15–24 age group. Some family groups avoided the plague altogether, others suffered a single burial, however in some cases, individuals within the same family household were buried within a short period of each other. The epidemiological pattern is complex and is moderated by social and demographic networks. Comparisons are made with modern epidemics caused byYersinia pestis.
Married and not: Weston's grown children in 1268–1269
Authors: Bennett Judith M.
Published: July 2019

In 1268–1269 Spalding Priory created an inventory of its male serfs in Weston and the whereabouts of their offspring. Historical demographers have long laboured over this unique document, but their efforts have brought more confusion than consensus. Aiming to revive the historical utility of the Weston inventory, this article provides context for the inventory and access to the text itself. It also reorients analysis of the inventory away from a focus on households and families (both unsatisfactorily reported) and towards the extensive information it contains about how a generation of serf children grew into adulthood.
MACRO- AND MICROPRUDENTIAL POLICIES: SWEET AND LOWDOWN IN A CREDIT NETWORK AGENT-BASED MODEL
Authors: Catullo Ermanno , Giri Federico , Gallegati Mauro
Published: July 2019

The paper presents an agent-based model reproducing a stylized credit network that evolves endogenously through the individual choices of firms and banks. We introduce in this framework a financial stability authority in order to test the effects of different prudential policy measures designed to improve the resilience of the economic system. Simulations show that a combination of micro- and macroprudential policies reduces systemic risk but at the cost of increasing banks’ capital volatility. Moreover, the agent-based methodology allows us to implement an alternativemesoregulatory framework that takes into consideration the connections between firms and banks. This policy targets only the more connected banks, increasing their capital requirement in order to reduce the diffusion of local shocks. Our results support the idea that the mesoprudential policy is able to reduce systemic risk without affecting the stability of banks’ capital structure.
UNIVERSES AND UNIVALENCE IN HOMOTOPY TYPE THEORY
Authors: LADYMAN JAMES , PRESNELL STUART
Published: July 2019

The Univalence axiom, due to Vladimir Voevodsky, is often taken to be one of the most important discoveries arising from the Homotopy Type Theory (HoTT) research programme. It is said by Steve Awodey that Univalence embodies mathematical structuralism, and that Univalence may be regarded as ‘expanding the notion of identity to that of equivalence’. This article explores the conceptual, foundational and philosophical status of Univalence in Homotopy Type Theory. It extends our Types-as-Concepts interpretation of HoTT to Universes, and offers an account of the Univalence axiom in such terms. We consider Awodey’s informal argument that Univalence is motivated by the principle that reasoning should be invariant under isomorphism, and we examine whether an autonomous and rigorous justification along these lines can be given. We consider two problems facing such a justification. First, there is a difference between equivalence and isomorphism and Univalence must be formulated in terms of the former. Second, the argument as presented cannot establish Univalence itself but only a weaker version of it, and must be supplemented by an additional principle. The article argues that the prospects for an autonomous justification of Univalence are promising.