bluuebunny/crossref_metadata_2025 huggingface dataset:
Classical and nonclassical effects in surface hopping methodology for simulating coupled electronic-nuclear dynamics
Authors: Martens Craig C.
Published: May 2019

In this paper, we analyze the detailed quantum-classical behavior of two alternative approaches to simulating molecular dynamics with electronic transitions: the popular fewest switches surface hopping (FSSH) method, introduced by Tully in 1990 [Tully, J. Chem. Phys., 1990, 93, 1061] and our recently developed quantum trajectory surface hopping (QTSH) method [Martens, J. Phys. Chem. A, 2019, 123, 1110].
A facile strategy for photoactive nanocellulose-based antimicrobial materials
Authors: Alvarado David Ramirez , Argyropoulos Dimitris S. , Scholle Frank , Peddinti Bharadwaja S. T. , Ghiladi Reza A.
Published: May 2019

Anti-infective materials based upon renewable nanocellulose–porphyrin conjugates photodynamically inactivated four strains of drug-resistant bacteria and two viruses by 99.999+%.
Mo-Doped NiCu as an efficient and stable electrocatalyst for the hydrogen evolution reaction
Authors: Wang Zhengnan , Ge Xingbo , Li Zhihao , Wu Jing , Liang Zihao , Wang Shuang
Published: May 2019

A Mo-Doped NiCu electrocatalyst was fabricated via a one-step electrodeposition process on a Ti substrate as an efficient nonprecious catalyst for the HER.
High-efficiency transformation of amorphous carbon into graphite nanoflakes for stable aluminum-ion battery cathodes
Authors: Tu Jiguo , Wang Junxiang , Li Shijie , Song Wei-Li , Wang Mingyong , Zhu Hongmin , Jiao Shuqiang
Published: May 2019

The highly efficient catalyst-free, eco-friendly and low-temperature graphitization process is a novel strategy for achieving the conversion of amorphous carbon precursors into graphite.
Core–shell assembly of carbon nanofibers and a 2D conductive metal–organic framework as a flexible free-standing membrane for high-performance supercapacitors
Authors: Zhao Shihang , Wu Huihui , Li Yanli , Li Qin , Zhou Jiaojiao , Yu Xianbo , Chen Hongmei , Tao Kai , Han Lei
Published: May 2019

A hybrid core–shell material based on carbon nanofibers and a 2D conductive metal–organic framework has been fabricated into a flexible free-standing membrane as an electrode material for supercapacitors.
Nanoparticles based on retinoic acid caped with ferrocenium: a novel synthesized targetable nanoparticle both with anti-cancer effect and drug loading capacity
Authors: Wang Yibo , Zhao Bin , Wang Lu , Bu Wenhuan , Liu Shuwei , Sun Bin
Published: May 2019

A retinoic acid nanoparticle with the ability of carrying a second anti-cancer drug, taxol, was developed. The anti-cancer nanoparticles were shown to have a better application prospect than that of RA or taxol alone.
A thiochromenone antibiotic derived from the Pseudomonas quinolone signal selectively targets the Gram-negative pathogen Moraxella catarrhalis
Authors: Szamosvári Dávid , Schuhmacher Tamara , Hauck Christof R. , Böttcher Thomas
Published: May 2019

Scaffold engineering of the Pseudomonas quinolone signal results in a highly potent antibiotic with unprecedented species selectivity.
Heterodinuclear zinc and magnesium catalysts for epoxide/CO2 ring opening copolymerizations
Authors: Trott Gemma , Garden Jennifer A. , Williams Charlotte K.
Published: May 2019

Correction for ‘Heterodinuclear zinc and magnesium catalysts for epoxide/CO2 ring opening copolymerizations’ by Gemma Trott et al., Chem. Sci., 2019, DOI: 10.1039/c9sc00385a.
Confinement of subnanometric PdZn at a defect enriched ZnO/ZIF-8 interface for efficient and selective CO2 hydrogenation to methanol
Authors: Li Xinliang , Liu Guoliang , Xu Di , Hong Xinlin , Edman Tsang Shik Chi
Published: May 2019

Subnanometric PdZn at a defect enriched ZnO/ZIF-8 interface acts as an efficient and selective catalyst for CO2 hydrogenation to methanol.
Emerging therapeutic applications of CRISPR genome editing
Authors: Qasim Waseem
Published: May 2019

The rapid evolution of tools for genome editing has created a dizzying array of possibilities for novel therapeutic strategies, even though to date only a handful of clinical applications have been realised. Proof-of-concept demonstrations of targeted genome modification in vitro and in small animal models of inherited single gene disorders have to be translated into effective therapies. Interest has naturally gravitated towards opportunities for collection, ex vivo modification and return of blood, immune and stem cells. Initial applications designed to modify T cells to protect against HIV or to confer potent anti-leukaemic effects have reached clinical phase, and further applications to modify blood stem cells are close to being applied. There are generic considerations of safety, on- and off-target effects and possible genotoxicity as well as issues relating to more sophisticated systemic approaches where niche occupation and host immunity become relevant. Such issues will be likely addressed over time, with carefully designed clinical trials required to determine therapeutic risks and benefits.
The Methodological Quality of Short-Term/Working Memory Treatments in Poststroke Aphasia: A Systematic Review
Authors: Zakariás Lilla , Kelly Helen , Salis Christos , Code Chris
Published: May 2019

Purpose

The aims of this systematic review are to provide a critical overview of short-term memory (STM) and working memory (WM) treatments in stroke aphasia and to systematically evaluate the internal and external validity of STM/WM treatments.

Method

A systematic search was conducted in February 2014 and then updated in December 2016 using 13 electronic databases. We provided descriptive characteristics of the included studies and assessed their methodological quality using the Risk of Bias in N-of-1 Trials quantitative scale (
Tate et al., 2015
), which was completed by 2 independent raters.

Results

The systematic search and inclusion/exclusion procedure yielded 17 single-case or case-series studies with 37 participants for inclusion. Nine studies targeted auditory STM consisting of repetition and/or recognition tasks, whereas 8 targeted attention and WM, such as attention process training including
n
-back tasks with shapes and clock faces as well as mental math tasks. In terms of their methodological quality, quality scores on the Risk of Bias in N-of-1 Trials scale ranged from 4 to 17 (
M
= 9.5) on a 0–30 scale, indicating a high risk of bias in the reviewed studies. Effects of treatment were most frequently assessed on STM, WM, and spoken language comprehension. Transfer effects on communication and memory in activities of daily living were tested in only 5 studies.

Conclusions

Methodological limitations of the reviewed studies make it difficult, at present, to draw firm conclusions about the effects of STM/WM treatments in poststroke aphasia. Further studies with more rigorous methodology and stronger experimental control are needed to determine the beneficial effects of this type of intervention. To understand the underlying mechanisms of STM/WM treatment effects and how they relate to language functioning, a careful choice of outcome measures and specific hypotheses about potential improvements on these measures are required. Future studies need to include outcome measures of memory functioning in everyday life and psychosocial functioning more generally to demonstrate the ecological validity of STM and WM treatments.
Modified switching scheme‐based explicit torque control of brush‐less direct current motor drive
Authors: Nair Deepthi S. , G Jagadanand , George Saly
Published: May 2019

A modified explicit torque control (ETC) scheme for permanent magnet (PM) machine with non‐sinusoidal back emf is investigated in this article. The conventional ETC scheme for the PM machines with non‐sinusoidal back emf furnishes a wide band for the switching frequency and offers a faster response in the torque. In this article, a modified scheme for switching vector selection is proposed to reduce the switching frequency while maintaining the advantage of faster torque response. Other than the conventional two‐phase excitation, which uses opposite vectors for switching to get the speedier response in torque, the modifications proposed for the ETC of PM machine are (i) a closer vector selection from the available two‐phase vector plane and (ii) a combination of two phase and three phase excitation. Both these modifications gives a faster response in the torque as that of conventional ETC, while this offers a reduction in the switching frequency. Switching frequency variations are expressed mathematically, and experimental results are presented for the modified schemes of ETC and for the conventional ETC based to validate the proposed scheme.
Fine‐tuning restricted Boltzmann machines using quaternions and its application for spam detection
Authors: da Silva Luis A. , da Costa Kelton A.P. , Papa João P. , Rosa Gustavo , de Albuquerque Victor Hugo C.
Published: May 2019

Restricted Boltzmann Machines (RBMs) have been used in a number of applications, but only a few works have addressed them in the context of information security. However, such models have their performance severely affected by some hyperparameters that are usually hand‐tuned. In this work, the authors consider learning features in an unsupervised fashion by means of RBMs fine‐tuned by hypercomplex‐based metaheuristic techniques in the context of malicious content detection. Experiments are conducted over three public datasets and six metaheuristic techniques, which are used to fine‐tune RBM hyperparameters such that RBM extracts features that best represent malicious content present in spam e‐mail messages, and generates a dataset to be used as input to classification through the Optimum Path Forest supervised algorithm. Experimental results demonstrate that a small number of features generated through RBM can achieve a competitive accuracy in relation to the original dataset, however, with lower computational cost. Furthermore, this study presents the power of quaternions for RBMs parameter optimisation, comparing it against the well‐known Harmonic Search, as well as its variants Improved Harmonic Search and Parameter Setting‐Free Harmonic Search. It was concluded that RBM‐based learning techniques are suitable for features extraction in the context of this work.
Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta
Authors: Tubiana C. , Rinaldi G. , Güttler C. , Snodgrass C. , Shi X. , Hu X. , Marschall R. , Fulle M. , Bockelée-Morvan D. , Naletto G. , Capaccioni F. , Sierks H. , Arnold G. , Barucci M. A. , Bertaux J.-L. , Bertini I. , Bodewits D. , Capria M. T. , Ciarniello M. , Cremonese G. , Crovisier J. , Da Deppo V. , Debei S. , De Cecco M. , Deller J. , De Sanctis M. C. , Davidsson B. , Doose L. , Erard S. , Filacchione G. , Fink U. , Formisano M. , Fornasier S. , Gutiérrez P. J. , Ip W.-H. , Ivanovski S. , Kappel D. , Keller H. U. , Kolokolova L. , Koschny D. , Krueger H. , La Forgia F. , Lamy P. L. , Lara L. M. , Lazzarin M. , Levasseur-Regourd A. C. , Lin Z.-Y. , Longobardo A. , López-Moreno J. J. , Marzari F. , Migliorini A. , Mottola S. , Rodrigo R. , Taylor F. , Toth I. , Zakharov V.
Published: May 2019

Context.On 27 April 2015, when comet 67P/Churyumov-Gerasimenko was at 1.76 au from the Sun and moving toward perihelion, the OSIRIS and VIRTIS-M instruments on board the Rosetta spacecraft simultaneously observed the evolving dust and gas coma during a complete rotation of the comet.

Aims.We aim to characterize the spatial distribution of dust, H2O, and CO2gas in the inner coma. To do this, we performed a quantitative analysis of the release of dust and gas and compared the observed H2O production rate with the rate we calculated using a thermophysical model.

Methods.For this study we selected OSIRIS WAC images at 612 nm (dust) and VIRTIS-M image cubes at 612 nm, 2700 nm (H2O emission band), and 4200 nm (CO2emission band). We measured the average signal in a circular annulus to study the spatial variation around the comet, and in a sector of the annulus to study temporal variation in the sunward direction with comet rotation, both at a fixed distance of 3.1 km from the comet center.

Results.The spatial correlation between dust and water, both coming from the sunlit side of the comet, shows that water is the main driver of dust activity in this time period. The spatial distribution of CO2is not correlated with water and dust. There is no strong temporal correlation between the dust brightness and water production rate as the comet rotates. The dust brightness shows a peak at 0° subsolar longitude, which is not pronounced in the water production. At the same epoch, there is also a maximum in CO2production. An excess of measured water production with respect to the value calculated using a simple thermophysical model is observed when the head lobe and regions of the southern hemisphere with strong seasonal variations are illuminated (subsolar longitude 270°–50°). A drastic decrease in dust production when the water production (both measured and from the model) displays a maximum occurs when typical northern consolidated regions are illuminated and the southern hemisphere regions with strong seasonal variations are instead in shadow (subsolar longitude 50°–90°). Possible explanations of these observations are presented and discussed.
Asymmetric Mannich Reaction of N-Boc Imines with Alkylmalononitriles Catalyzed by Dinuclear PhosphoiminoBINOL-Pd Complex
Authors: Arai Takayoshi , Nakamura Ayu
Published: May 2019

PhosphoiminoBINOL-Pd2(OAc)2 complex catalyzed asymmetric Mannich reaction of N-Boc imines with alkyl malononitriles, with assistance of Zn(OAc)2 gave chiral amines with adjacent all-carbon quaternary carbon centers in up to 99% yield with 94% ee.
Giant Mesenteric Cyst and Right Sided Syndrome in a 15-Year-Old Boy
Authors: Tamene Ayanaw , Desta Melkam , Tebeje Habeneyom , Getie Yeshiambel , Berhane Hailemariam
Published: May 2019

Giant mesenteric cyst is a rare benign abdominal tumor. It usually arises from the mesenteric side of the small bowel. Right side syndrome is the term used for congenital absence of right kidney and right testis. We report on a 15-year-old male who presented with progressive abdominal distension, early satiety, and difficulty walking or running. Abdominal ultrasound and computed tomography (CT) revealed a giant mesenteric cyst, absence of the right kidney, and left moderate hydronephrosis. After excision of the cyst, the patient was fully recovered. Our report shows that both conditions may occur in the same patient and therefore an association of these two diseases cannot be excluded.
Hibernoma de mano – reporte de un caso
Authors: Craviotto Matias , Wolff Daniel , d'Oliveira Lucia
Published: May 2019

Los lipomas son infrecuentes en la mano y representan aproximadamente el 1% de los tumores. Los hibernomas son tumores benignos lipomatosos raros, compuestos al menos en parte por células de grasa parda con citoplasma granular multivacuolado. El estudio por RMN es de gran utilidad, actualmente imprescindible. En la resonancia magnética se observan como una masa heterogénea. La presencia de células inmaduras multivacuoladas en la microscopia, confirman el diagnóstico de hibernoma. El tratamiento quirúrgico es de elección.
Morphometric Analysis of the Foramen Magnum in Dry Human Skulls in Northeastern Brazil
Authors: de Lucena Jalles Dantas , Sanders João Victor Souza , de Brito Hudson Martins , Cerqueira Gilberto Santos , da Silva Ivson Bezerra , Oliveira André de Sá Braga
Published: May 2019

Introduction The successful identification of the deceased is vital to the progress of any forensic investigation. This process of identification is facilitated by the determination of age, gender, and ethnicity. One of the main biological traits to be established from skeletal remains is the gender of the individual. In situations in which there are fragmented and mutilated skeletal remains, gender determination is relatively difficult, and it becomes important to establish the accuracy of individual bones. The basal region of the occipital bone is covered by a large volume of soft tissue and is therefore in a relatively well-protected anatomical position and, as such, classification of gender using the occipital bone may prove to be useful in cases of significantly disrupted remains. The present study aims to describe and analyze the morphological aspects of the foramen magnum (FM) in the population of the northeastern region of Brazil.

Material and Methods A total of 159 dry skulls (88 males and 71 females) were subjected to measurement by a digital caliper (DIGIMESS®, Instrumentos de Precisão Ltda., São Paulo, Brazil) and was assessed for anteroposterior diameter (APD) and transverse diameter (TD), FM area, FM index (FMI), anterior, posterior and maximum lateral intercondylar distance. The measurement of all of these parameters sought to classify the FM in nine different types.

Results The pentagonal type was the most found in males (11.31%), and the biconvex in females (18.86%). The less frequent type in males was the pear type (2.53%), and in females the less frequent types were the pentagonal and the heptagonal types (2.53% each). Using the traditional anthropological classification of Martin et al,13 the most common type of FM was the brachytrematous, with 49.68% of the total skulls. The APD, TD and FM area were higher in males than in females, only in the oval FM type.

Conclusion The sexual dimorphism of the dimensions of the FM is established. However, there is a wide variability in the shape and measures in different populations, and to our knowledge this is the first study that shows the different types of the FM in the population of the northeastern region of Brazil.
Effect of Hypothermia and Severity of Hypoxic-Ischemic Encephalopathy in the Levels of C-Reactive Protein during the First 120 Hours of Life
Authors: Cilla Amaia , Arnaez Juan , Benavente-Fernández Isabel , Ochoa Carlos , Vega Cristina , Lubián-López Simón , Garcia-Alix Alfredo
Published: May 2019

Objective This study aimed to describe normal C-reactive protein (CRP) levels of newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) and assess the influence of therapeutic hypothermia (TH) and the severity of HIE.

Study Design We prospectively recruited infants ≥35 weeks of gestational age diagnosed with HIE from 2000 to 2013 and compared CRP levels in the first 120 hours of life according to the severity of HIE and the use of TH, which was introduced in 2009.

Results Moderate HIE was diagnosed in 115 newborns, severe HIE in 90 (hypothermia was performed in 151 cases), and mild HIE in 20. Cooled newborns showed lower levels of CRP in the first 34 hours, but reached higher median maximum CRP levels (15.4 vs. 8.5 mg/L), and at a significantly older age (53 vs. 17 hours). Levels of CRP in mild HIE were lower than those of moderate–severe forms. Moderate and severe HIE had similar CRP levels, but time to maximum CRP was significantly less in moderate cases.

Conclusion CRP levels of mild HIE are similar to healthy newborns, while CRP elevations can be expected in newborns with moderate–severe HIE. TH produced a slower rise, with a higher and late maximum CRP peak level.
Sternal Muscle: A Case Report
Authors: de Aguiar Pamela Kelly Farias , Silva Anna Caroline Duarte Costa , Oliveira André de Sá Braga , Santos Luciano Edgley dos , Gomes Felippe Barbosa , Assis Thiago de Oliveira
Published: May 2019

Introduction The sternal muscle is an anatomical variation found in the anterior region of the thorax.

Objective To report the anatomical characteristics of a new type of sternal muscle.

Case Report This was a dissection study in which the sternal muscle found was unilateral and long.

Discussion Proximal fixation differs from the classification adopted for these cases. Documentation of sternal muscle variations can improve the theoretical database in anatomy as well as aid diagnoses, reducing the probability of the unexpected during clinical and/or surgical thorax-related investigations.
Gradient flow structure and exponential decay of the sandwiched Rényi divergence for primitive Lindblad equations with GNS-detailed balance
Authors: Cao Yu , Lu Jianfeng , Lu Yulong
Published: May 2019

We study the entropy production of the sandwiched Rényi divergence under the primitive Lindblad equation with Gel’fand–Naimark–Segal-detailed balance. We prove that the Lindblad equation can be identified as the gradient flow of the sandwiched Rényi divergence of any order α ∈ (0, ∞). This extends a previous result by Carlen and Maas [J. Funct. Anal. 273(5), 1810–1869 (2017)] for the quantum relative entropy (i.e., α = 1). Moreover, we show that the sandwiched Rényi divergence of any order α ∈ (0, ∞) decays exponentially fast under the time evolution of such a Lindblad equation.
Non-equilibrium effects of micelle formation as studied by a minimum particle-based model
Authors: Raschke Simon , Heuer Andreas
Published: May 2019

The formation of self-assembled structures such as micelles has been intensively studied and is well understood. The ability of a solution of amphiphilic molecules to develop micelles is dependent on the concentration and characterized by the critical micelle concentration (cmc), above which micelle formation does occur. Recent studies use a lattice approach in order to determine cmc and show that the correct modeling and analysis of cluster formations is highly nontrivial. We developed a minimalistic coarse grained model for amphiphilic molecules in the continuum and simulated the time evolution via dynamic Monte Carlo simulations in the canonical (NVT) ensemble. Starting from a homogeneous system, we observed and characterized how the initial fluctuations, yielding small aggregates of amphiphilic molecules, end up in the growth of complete micelles. Our model is sufficiently versatile to account for different structures of surfactant systems such as membranes, micelles of variable radius, and tubes at high particle densities by adjusting particle density and potential properties. Particle densities and micellization rates are investigated and an order parameter is introduced so that the dependence of the micellization process on temperature and surfactant density can be studied. The constant density of free particles for concentrations above cmc, e.g., as expected from theoretical considerations, can be reproduced when choosing a careful definition of free volumes. In the cmc regime at low temperatures, different nonequilibrium effects are reported, occurring even for very long time scales.
Subthreshold electron transport properties of ultrathin film phase change material Ge2Sb2Te5
Authors: Roohforouz Ali , Shokri Aliasghar
Published: May 2019

The electron transport properties of ultra-scaled phase change material Ge2Sb2Te5 (GST) are investigated in a subthreshold bias range. We used ab-initio molecular dynamics (AIMD) and non-equilibrium Green’s function (NEGF) transport formalism based on density functional theory (DFT). We calculate the conductance and current-voltage (I-V) curve of both crystalline (c-GST) and amorphous GST (a-GST). Our purely ab-initio simulations show that the conduction mechanism of ultra-scaled a-GST is different from that of c-GST. The current-voltage (I-V) curve of a-GST shows linear and exponential behavior. Both the bias induced variation of the transmission coefficients and the enlarging of bias window is responsible for the exponential shape of the I-V curve for a-GST. Whereas the linear part of the I-V curve is a consequence of the bias window enlarging. Moreover, it is revealed that the electron transport properties of ultra-scaled c-GST are dominated by metal-induced gap states (MIGS). The measured ON/OFF ratio and I-V curves are in good agreement with the similar experimental results. The findings of this paper would be useful in designing the ultra-scaled PCM devices based on GST and the designers should consider the difference in conduction mechanism of a-GST and c-GST as a potential reason for the different behavior of their I-V and conductance curve.
Optically tunable magnetoelectric properties of inorganic-organic multiferroic flexible film
Authors: Chakraborty Sarit , Mandal S. K. , Saha B.
Published: May 2019

Magnetoelectric composites are promising materials for their physical properties such as spontaneous electrical polarization or magnetization with the application of magnetic or electric field. In addition, Spinel ferrite based magnetoelectric composite materials absorb a range of light energy, which offers a lot of physical phenomena behind the light-dependent magnetoelectric properties of the composite. The piezoelectric organic polymer based magnetoelectric composite of Zn0.2Co0.8Fe2O4-poly(vinylidene fluoride) flexible film has been fabricated by a chemical pyrophoric reaction process followed by a solution casting process. Structural and surface morphologies of the composite film have been studied. The visible light and applied magnetic field dependent AC electrical properties of the composite flexible film have been investigated at room temperature which reveals that the maximum change in impedance is found to be ∼10% and ∼20%, respectively. However, with an influence of both the light and the magnetic field, the impedance of the composite film is largely changed attributing that the excited electron may get a low resistive path through the grain and grain boundaries where the maximum change in impedance is found to be ∼30%. This result further is confirmed from the change of grain and grain boundary resistance and capacitance through the fitting of Nyquist plots. The present work provides information about the optically and magnetically influenced physical properties of the composite flexible film, which will be expanded for multiferroic magnetoelectric device applications.
Whistler wave generation by electron temperature anisotropy during magnetic reconnection at the magnetopause
Authors: Yoo Jongsoo , Wang Shan , Yerger Evan , Jara-Almonte J. , Ji Hantao , Yamada Masaaki , Chen Li-Jen , Fox William , Goodman Aaron , Alt Andrew
Published: May 2019

Two magnetopause reconnection events of the Magnetospheric Multiscale mission with whistler wave activity are presented. The whistler mode around half of the electron cyclotron frequency is excited near the magnetospheric separatrix. In both events, there are positive correlations between the whistler wave and the lower hybrid drift instability (LHDI) activities, indicating a possible role of LHDI in the whistler wave generation. A sudden change in the electron pitch angle distribution (PAD) function of energetic electrons is observed right after intense LHDI activity. This change in the PAD leads to temperature anisotropy in energetic electrons which is responsible for the whistler wave excitation. The measured dispersion relation demonstrates that the whistler wave propagates toward the X line nearly parallel to the magnetic field line. Finally, a linear analysis with the measured distribution function verifies that the whistler mode is excited by the temperature anisotropy in energetic electrons.
Low-gradient, single-threaded rivers prior to greening of the continents
Authors: Ganti Vamsi , Whittaker Alexander C. , Lamb Michael P. , Fischer Woodward W.
Published: May 2019

Significance

The origin of low-gradient meandering rivers—the primary conduits of water, carbon, and nutrients in present-day terrestrial landscapes—is considered coeval with Silurian-age plant evolution. It was hypothesized that pre-Silurian rivers lacked bank strength and were dominantly steep and braided, implying vastly different transport capacities of water and sediment. This idea, however, is inconsistent with the supercontinental-scale drainage of Neoproterozoic rivers, which requires unrealistically high mountains to achieve the necessary river gradients. Using geologic observations and paleohydraulic analyses, we show that pre-Silurian rivers were low-gradient, deep, and single-threaded—similar to modern meandering rivers. Results demonstrate uniformity of fluvial morphology despite a global revolution in Earth’s terrestrial biota, with ramifications for the topographic signature of life on Earth and other planets.
Role of Polo-like kinase 1 in the regulation of the action of p31
comet
in the disassembly of mitotic checkpoint complexes
Authors: Kaisari Sharon , Shomer Pnina , Ziv Tamar , Sitry-Shevah Danielle , Miniowitz-Shemtov Shirly , Teichner Adar , Hershko Avram
Published: May 2019

Significance

The mitotic checkpoint system ensures the accuracy of chromosome segregation in mitosis. It detects incorrect attachment of chromosomes to the mitotic spindle and promotes the assembly of a Mitotic Checkpoint Complex (MCC). MCC inhibits the ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C), whose action is required for chromosome separation. The disassembly of MCC is required for the inactivation of the mitotic checkpoint, but the regulation of MCC disassembly is not sufficiently understood. Here, we show that the mitotic protein kinase Polo-like kinase 1 (Plk1) regulates MCC disassembly by inhibitory phosphorylation of p31
comet
, an important component of the disassembly machinery. These results reveal an important mechanism to regulate MCC levels in the mitotic checkpoint.
Are Extended Defects a Show Stopper for Future III-V CMOS Technologies
Authors: Claeys C , Hsu P-C , He L , Mols Y , Langer R , Waldron N , Eneman G , Collaert N , Heyns M , Simoen E
Published: May 2019

The paper briefly reviews some of the present-day state-of-the art III-V devices processed on a Si platform reported in the literature, before addressing defect engineering aspects for III-V processing on a Si substrate from both a structural and electrical performance perspective. The identification of the extended defects will be illustrated by some case studies based on leakage current and lifetime investigations, Deep Level Transient Spectroscopy (DLTS) analysis and low frequency noise spectroscopy. Information on the basic defect parameters can be used as input for TCAD simulation of the electrical device performance, enabling a further optimization of the materials’ growth and process conditions.
Plastic behaviour and deformation mechanisms in silicon nano-objects
Authors: Texier M , Merabet A , Tromas C , Brochard S , Pizzagalli L , Thilly L , Rabier J , Talneau A , Le Vaillant Y-M , Thomas O , Godet J
Published: May 2019

Physical properties of nano-objects differ from what they are in bulk materials when the size decreases down to the nanometre scale. This behavioural change, named size effect, also applies to mechanical properties and has been evidenced in various materials. For instance, at low temperature, bulk silicon is known to be a brittle material while silicon nano-objects exhibit a ductile behavior. Although mechanical properties of silicon have been intensively studied over the last decades, the origin of this remarkable brittle-to-ductile transition at small scales remains, however, undetermined. In this article, a study of the plastic behaviour of nano-pillars is reported. The main results obtained from the combination of numerical calculations and experimental compression tests followed by atomically-resolved transmission electron microscopy imaging are described. We discuss the possibility for perfect dislocations to dissociate at low temperature and the underrated role of shuffle partial dislocations in plastic deformation of silicon. The formation of unexpected extended defects in the {115} planes with increasing plastic strain, also appears as a key-factor leading to the transition between ductile and brittle regimes at small scales.
Extended core structure and luminescence of a-screw dislocations in GaN
Authors: Medvedev O S , Vyvenko O F , Ubyivovk E V , Shapenkov S V , Seibt M
Published: May 2019

Straight segments of a-screw dislocations introduced by scratching of basal (0001) of intentionally undoped low-ohmic GaN radiate a doublet of narrow luminescent lines in the spectral region at about 3.1-3.2 eV while the dislocation intersection points possess luminescence band at about 3.3 eV. Transmission electron microscopy reveals that the dislocation cores are dissociated into two 300 partials separated by stacking fault (SF) ribbon with the width of 4-6 nm width and that the dislocation nodes contain extended SF of sizes of 25-30 nm. Dislocation-related luminescence (DRL) is ascribed to exciton bound by the states of partial dislocation cores and of SF quantum well. The increase of the SF lateral sizes is assumed to cause the DRL spectral shift between straight dislocations and their nodes due to the system dimensionality transition from 1D to 2D respectively.
High-resolution Scanning Transmission EBIC Analysis of Misfit Dislocations at Perovskite pn-Heterojunctions
Authors: Meyer T , Kressdorf B , Lindner J , Peretzki P , Roddatis V , Jooss C , Seibt M
Published: May 2019

Fundamental losses of photovoltaic energy conversion are transmission of sub band gap photons and thermalisation which are the underlying physics of the Shockley-Queisser limit defining maximum conversion efficiency of single-junction solar cells. Strongly correlated materials such as perovskites are promising candidates to exceed this limit by exploiting (i) long wavelength light absorption and (ii) the existence of long-living intraband excitations indicating that harvesting hot excess carriers might be feasible in such systems. In this work, we study pn-heterojunctions produced from Pr1-

x
Ca
x
MnO3 on SrTi1-

y
Nb
y
O3 by means of microscopic techniques. Such systems exhibit relevant quantities such as space charge layer width, screening lengths and excess carrier diffusion lengths in the 1-10 nm range which makes the use of standard methods such as electron beam induced current a challenging task. We report scanning transmission electron beam induced current experiments of misfit dislocations at the heterojunction. The dislocation-induced reduction of the charge collection is studied with nanometer spatial resolution. Effects of surface recombination and the heterojunction electric field are discussed.
Bandgap, electrical and structural properties of thick InN (0001) films grown under optimal conditions
Authors: Adikimenakis A. , Androulidaki M. , Foundoulaki Salhin E. , Tsagaraki K. , Doundoulakis G. , Kuzmik J. , Georgakilas A.
Published: May 2019

The improvement potential for the structural, electrical and opto-electronic properties of heteroepitaxial InN-on-GaN (0001) films by using optimal conditions (substrate temperature, In and N fluxes) of plasma-assisted molecular beam epitaxy and increasing the epilayer thickness to few micrometres has been investigated. The increase of InN thickness to 3.7 μm resulted to a-type component threading dislocation density of 6x109 cm−2 and directly measured electron mobility of 2330 cm2/Vs and concentration of 4.5x1017 cm−3. The optical bandgap of this film at 300K was 0.637 eV. However, a degradation in the integrity of the interfacial InN/GaN region was observed in films thicker than 1 μm, with the formation of voids and the nucleation of microcracks, which may be related to strain relaxation or thermal decomposition.
Trap-assisted tunnelling and Shockley-Read-Hall lifetime of extended defects in In.53Ga.47As p+n junction
Authors: Hsu P C (Brent) , Simoen E , Eneman G , Merckling C , Alian A , Langer R , Collaert N , Heyns M
Published: May 2019

Several In.53Ga.47As p+n junctions with various extended defect densities (EDDs) have been grown by metalorganic vapor phase epitaxy (MOVPE), by carefully controlling the growth conditions. After fabrication, T-dependent J-V, C-V and double DLTS (DDLTS) are performed to extract the electrical field dependence of the extended defect levels. From this characterization, it is derived that the extended defects dominate the electrical field enhancement factor Г regardless of the value of the EDD and significantly increases the leakage current under reverse bias (i.e., decrease the Shockley-Read-Hall lifetime). These impacts are strongly connected to a “band-like” density of states of extended defects E2 at EC-0.32 eV by comparing the DDLTS and T-dependent J-V characteristics. On the other hand, the reference sample (without EDs) surprisingly exhibits an even stronger field dependence with lower leakage current. Nevertheless, no straightforward candidate point defects can be found in this sample and the possible explanation are discussed.
Variability in urban population distributions across Africa
Authors: Tuholske Cascade , Caylor Kelly , Evans Tom , Avery Ryan
Published: May 2019

Africa is projected to add one billion urban residents by 2050. Yet developing sustainable solutions to tackle the host of challenges posed by rapid urban population growth is stymied by a lack municipality-level population data across the continent. To fill this gap, we intersect volunteered urban settlement data from OpenStreetMap with five synthetic gridded population datasets to estimate the how Africa’s urban population is distributed among over 4750 individual urban settlements across Africa. We assess how urban settlement distributions changed from 2000 to 2015 within and between countries and across moisture zones. To this end, we construct urban settlement Lorenz curves to calculate change in Gini coefficients and test the degree to which Africa’s urban settlements distributions fit power law distributions exhibited by Zipf’s law. Our results reveal that 77%–85% of urban settlements in Africa have fewer than 100 000 people and that at least 50% of Africa’s urban population live in urban settlements with fewer than 1 million residents. Across almost all African countries, the distribution of urban population shifted towards larger cities between 2000 and 2015. However, in arid regions, our results indicate that small- and medium-sized urban settlements are absorbing a greater share of urban population growth compared to large urban settlements. While our urban population estimates vary across gridded population datasets and differ from United Nations estimates, this is the first paper to measure urban population across Africa using a consistent methodology to identify urban settlement populations. Unlike UN urban population data for Africa, our results can readily be incorporated with geolocated environmental, public health, and economic data to support efforts to monitor United Nations Sustainable Development Goals related to urban sustainability, poverty reduction, and food security across Africa’s ever-growing urban settlements.
Isolation and identification of bacteria with antimicrobial activities from green algae (Halimeda discoidea) from Pulau Lima, Banten Bay, Indonesia
Authors: Bawanti N P S C , Siregar R R , Kristianty M G E , Indriati N
Published: May 2019

Bacteria associated with seaweed were involved in the production of metabolites associated with their host, so they tend to have nearly the same metabolites to defend themselves or as antibiotics. The aim of this study was to isolate and to identify bacteria with antimicrobial activities from the marine green algae (Halimeda discoidea). Laboratory analysis was for the isolation of bacteria, selection of bacteria with antimicrobial activities, antibacterial activity tests and Minimum Inhibitory Concentration (MIC). Results showed that six bacterial isolates were isolated from outside and inside of the algae, which have antimicrobial activities. One was selected for further work which was have more antimicrobial activities. The bacteria showed antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus) but not against Gram-negative bacteria (Escherichia coli). The bacterial growth curve was at an optimum phase at the 10th to 16th hour. Microscopic analysis and biochemical tests showed that isolated bacteria were a rod-shaped Gram-negative, acid-free, non-endosporous, reacted positively to gelatin, citrate and carbohydrate, reacting negatively on motile, and urease. We conclude that the bacteria isolated from green algae which had more antimicrobial properties belongs to the genus Pseudomonas guezennei.
Carbon storage in seagrass meadow of Teluk Bakau – Bintan Island
Authors: Nugraha A H , Kawaroe M , Srimariana E S , Jaya I , Apdillah D , Deswati S R
Published: May 2019

Seagrass has the ability to store carbon through photosynthesis. The ability is influenced by environmental factors. This study was aimed to examine the diversity of seagrass and investigate the carbon storage in seagrass’ biomass in two stations at Teluk Bakau Village, Bintan Island. This research was conducted at two stations including Beralas Pasir Island (small island) and Teluk Bakau Village Beach (mainland). Measure of seagrass biomass with dried seagrass sample was carried out at 60°C temperature. The analysis of carbon content was carried out on the biomass of the four dominant seagrass species found in the Teluk Bakau Village namely Cymodocea rotundata, Enhalus acoroides, Syringodium isoetifolium, Thalassia hemprichii. The results show that the carbon storage on seagrass has a correlation with seagrass biomass. Enhalus acoroides has the highest carbon content compared to the other three seagrass species. In general, seagrass located in Teluk Bakau Village Beach have higher biomass than seagrass located in Beralas Pasir Island, and it means that they have high carbon storage. This is expected to occur considering that the area of Teluk Bakau Village Beach is close to the mainland, where there is a high nutrient input support for the growth of seagrass biomass.
Interannual variability of Indonesian throughflow in the Flores Sea
Authors: Putriani P Y , Atmadipoera A S , Nugroho D
Published: May 2019

The main branch of Indonesian Throughflow (ITF) from Makassar Strait passes through Flores Sea. The variance of ITF transport volume was influenced by climate phenomenon such as El Nino Southern Oscillation (ENSO). This research was conducted to describe the relationship between the ENSO and the ITF transport variability. This relationship was explored using data from INDESO model 2008-2015. The variability of transport volume was analyzied using continous wavelet transform and band-pass analysis. Water circulation was analyzed by summing up the average of water current and sea temperatures. The Flores ITF was a portion of Makassar ITF and Eastern ITF that enter via Lifamatola Passage. The flow in the upper layer was intensified during the west monsoon while in the thermocline layer was intensified during the east monsoon. Flores ITF moved along the northern part of Flores Island and was dominated by zonal velocity component.
Endophytic microbes and antioxidant activities of secondary metabolites from mangroves Avicennia marina and Xylocarpus granatum
Authors: Rahmawati S I , Izzati F N , Hapsari Y , Septiana E , Rachman F , Bustanussalam  , Simanjuntak P
Published: May 2019

The utilization of mangrove plants as traditional medicinal ingredients has long been utilized by the community for treatment of various diseases in favour of bioactive components from its secondary metabolites. Secondary metabolites from mangroves could act as an antioxidant to prevent oxidative stress. Mangrove may contain endophytic microbes in its tissues that are capable of producing secondary metabolites. In theory, endophytic microbes isolated from a plant can produce secondary metabolites similar to those of the original plants or even in relatively high numbers. In this research, two mangrove species Avicennia marina and Xylocarpus granatum from Serang, Banten province, samples have been taken to investigate the antioxidant activities of its extracts. Furthermore, isolation of endophytic microbes from both mangroves had been done. This research succeeded to isolate six fungi and three bacteria as endophytic microbes. Meanwhile, the highest extraction yield was obtained by the leaves of A. marina that is approximately 3% (w/w), whereas mangroves’ endophytic microbe highest extract yield was obtained by bacteria from fruits of A. marina 18 mg/100 mL media. For antioxidant activities, the highest activities were obtained by fungi within the stems and the roots of A. marina, also additionally fungi in the leaves of X. granatum.
Phytochemical constituents and antidiabetic activity of edible marine red seaweed (Halymenia durvilae)
Authors: Sanger G , Rarung L K , Damongilala L J , Kaseger B E , Montolalu L A D Y
Published: May 2019

Seaweeds have bioactive compounds with enormous health prospective which interests the pharmaceutical industries. The isolated bioactive compounds of seaweeds have been utilized as drug and food in the world. Phytochemical constituents of seaweeds have an assortment of prospective biological activity, such as antidiabetes. In worldwide the appearance of type two diabetes mellitus (T2DM) as the greatest non-transmittable disease has motivated search for new antidiabetic approaches. The purpose of the research was to determine the phytochemical properties and antidiabetic effect using α-glukosidase on methanol extract, n-hexane, chloroform, and water fraction of marine red algae Halymenia durvilae. The result of this study showed the phyto-constituent of H.durvilae includes steroids, flavonoids and triterpenoids are present in all extracts. Saponins and hyquinones showed their presence only in methanol extract. Alkaloid and tannin were not present in methanol extract and its fractions. H.durvilae on the extract and its fractions had antidiabetic activity. Water fraction had the highest activity to inhibit α-glukosidase (IC50 4.34±0.32 mg mL) followed by chloroform, hexane and methanol extract. Therefore, it can be concluded that H.durvilae could be used as a dietary food source of bioactive compound especially natural antidiabetic compounds.
Exploring human-nature interaction on the coastal floodplain in the Ganges-Brahmaputra delta through the lens of Ostrom’s social-ecological systems framework
Authors: Gain Animesh K , Ashik-Ur-Rahman Md. , Vafeidis Athanasios
Published: May 2019

This study diagnoses temporal and spatial variations in the performance of different social-ecological systems (SES) in coastal floodplain management in the Ganges-Brahmaputra delta. We go beyond common pool resource management problems and address the management of local public goods. In the assessment, we consider recent developments in the framework initially developed by Elinor Ostrom. The main variables of the framework that we use are resource systems, the environment, the governance system and actors. The focal SES is defined based on guiding questions relating to the definition of the key problem, system boundaries, and action situations. According to our results, the performance of resource systems and the environment deteriorated in 1960–79 compared to the performance prior to 1960. The condition reached a low point during 1980–1999 but improved slightly after 1999. The horizontal network structure of local governance was active until 1960. Due to the introduction of the ‘tidal river management’ approach in the 90 s, the performance of the resource system and the environment has slightly improved, as has the involvement of government and non-government organizations. Our results also show that overall SES performance is comparatively better <in the case of locally managed floodplains than it is for those managed by government agencies. Our new approaches, such as the recent development of the diagnostic framework, the guiding questions for defining focal SES, and application of the framework to local public goods can potentially be used in the fields of sustainability science and SES science. The qualitative performance of each of the selected indicators is useful for identifying intervention options to achieve a sustainable outcome for the coastal floodplain SES.