bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding motor control in health and disease: classic single (n = 1) observations
Authors: Bloem Bastiaan R. , Monje Mariana H. G. , Obeso Jose A.
Published: March 2020

The field of neuroscience is increasingly dominated by a preferred use of big data, where analysis of large numbers has become an essential area of development. We here draw attention to the importance of smaller numbers, and more specifically, to the historical and continued importance of detailed and judiciously performed studies in single healthy volunteers or single patients with a unique clinical presentation, as an important approach to study normal functions of the nervous system, and to understand the pathophysiology underlying neurological movement disorders. We illustrate this by discussing several historical examples and by summarising Professor John Rothwell’s impressive body of work in single-patient studies, highlighting some of his seminal n = 1 studies that have had a great impact on the field. In doing so, we hope to provide a powerful incentive for the next generation of neuroscientists to keep appreciating the value of detailed analyses of single observations.
Diffeomorphism groups of critical regularity
Authors: Kim Sang-hyun , Koberda Thomas
Published: March 2020

Let M be a circle or a compact interval, and let $$\alpha =k+\tau \ge 1$$

α
=
k
+
τ
≥
1

be a real number such that $$k=\lfloor \alpha \rfloor $$

k
=
⌊
α
⌋

. We write $${{\,\mathrm{Diff}\,}}_+^{\alpha }(M)$$

Diff

+
α

(
M
)

for the group of orientation preserving $$C^k$$

C
k

diffeomorphisms of M whose kth derivatives are Hölder continuous with exponent $$\tau $$
τ
. We prove that there exists a continuum of isomorphism types of finitely generated subgroups $$G\le {{\,\mathrm{Diff}\,}}_+^\alpha (M)$$

G
≤

Diff

+
α

(
M
)

with the property that G admits no injective homomorphisms into $$\bigcup _{\beta >\alpha }{{\,\mathrm{Diff}\,}}_+^\beta (M)$$

⋃

β
>
α

Diff

+
β

(
M
)

. We also show the dual result: there exists a continuum of isomorphism types of finitely generated subgroups G of $$\bigcap _{\beta <\alpha }{{\,\mathrm{Diff}\,}}_+^\beta (M)$$

⋂

β
<
α

Diff

+
β

(
M
)

with the property that G admits no injective homomorphisms into $${{\,\mathrm{Diff}\,}}_+^\alpha (M)$$

Diff

+
α

(
M
)

. The groups G are constructed so that their commutator groups are simple. We give some applications to smoothability of codimension one foliations and to homomorphisms between certain continuous groups of diffeomorphisms. For example, we show that if $$\alpha \ge 1$$

α
≥
1

is a real number not equal to 2, then there is no nontrivial homomorphism $${{\,\mathrm{Diff}\,}}_+^\alpha (S^1)\rightarrow \bigcup _{\beta >\alpha }{{\,\mathrm{Diff}\,}}_+^{\beta }(S^1)$$

Diff

+
α

(

S
1

)

→

⋃

β
>
α

Diff

+
β

(

S
1

)

. Finally, we obtain an independent result that the class of finitely generated subgroups of $${{\,\mathrm{Diff}\,}}_+^1(M)$$

Diff

+
1

(
M
)

is not closed under taking finite free products.
Outcomes of Simultaneous Resections and Classical Strategy for Synchronous Colorectal Liver Metastases in Sweden: A Nationwide Study with Special Reference to Major Liver Resections
Authors: Valdimarsson Valentinus T. , Syk Ingvar , Lindell Gert , Sandström Per , Isaksson Bengt , Rizell Magnus , Norén Agneta , Ardnor Bjarne , Sturesson Christian
Published: March 2020

Background

About 20% of patients with colorectal cancer have liver metastases at the time of diagnosis, and surgical resection offers a chance for cure. The aim of the present study was to compare outcomes for patients that underwent simultaneous resection to those that underwent a staged procedure with the bowel‐first (classical) strategy by using information from two national registries in Sweden.

Methods

In this prospectively registered cohort study, we analyzed clinical, pathological, and survival outcomes for patients operated in the period 2008–2015 and compared the two strategies.

Results

In total, 537 patients constituted the study cohort, where 160 were treated with the simultaneous strategy and 377 with the classical strategy. Patients managed with the simultaneous strategy had less often rectal primary tumors (22% vs. 31%, p = 0.046) and underwent to a lesser extent a major liver resection (16% vs. 41%, p < 0.001), but had a shorter total length of stay (11 vs. 15 days, p < 0.001) and more complications (52% vs. 36%, p < 0.001). No significant 5‐year overall survival (p = 0.110) difference was detected. Twenty‐five patients had a major liver resection in the simultaneous strategy group and 155 in the classical strategy group without difference in 5‐year overall survival (p = 0.198).

Conclusion

Simultaneous resection of the colorectal primary cancer and liver metastases can possibly have more complications, with no difference in overall survival compared to the classical strategy.
Defining Major Surgery: A Delphi Consensus Among European Surgical Association (ESA) Members
Authors: Martin David , Mantziari Styliani , Demartines Nicolas , Hübner Martin ,   the ESA Study Group, Bismuth Henri , Sarr Michael G. , Strasberg Steven M. , Wexner Steven D. , Adham Mustapha , Altomare Donato F. , Andersson Roland , Bechstein Wolf , Biondo Sebastiano , Bockhorn Maximilian , Bonavina Luigi , Rituerto Daniel Casanova , Clavien Pierre‐Alain , De Manzini Nicolo , Decker George , Dejong Cornelis HC , Dervenis Christos , Farges Olivier , Figueras Joan , Fingerhut Abraham Louis , Friess Helmut , Glehen Olivier , Gnant Michael , Gutschow Christian , Hahnloser Dieter , Hamberger Bertil , Hamming Jacob Frans , Hölscher Arnulf H. , Izbicki Jakob R. , Jonas Sven , Karamarkovic Aleksandar , Kehlet Henrik , Leppäniemi Ari Kalevi , Lerut Jan , Line Pål‐Dag , Lodge J. Peter A. , Meakins Jonathan Larmonth , Montorsi Marco , Nafteux Philippe , Naredi Peter , Oláh Attila , Panis Yves , Pardo Fernando , Parks Rowan W. , Pedrazzoli Sergio , Pessaux Patrick , Marques Hugo Pinto , Poggioli Gilberto , Popescu Irinel , Puolakkainen Pauli Antero , Ramia Angel José M. , Rasanen Jari , Reynolds John Vincent , Rosati Riccardo , Saeger Hans‐Detlev , Schneeberger Stefan , Schneider Paul M. , Søreide Kjetil , Stippel Dirk , Toso Christian , Tuech Jean‐Jacques , Tukiainen Erkki Juhani , Van Hillegersberg Richard , Wijnhoven Bas , Winter Desmond C. , Zaninotto Giovanni
Published: March 2020

Background

Major surgery is a term frequently used but poorly defined. The aim of the present study was to reach a consensus in the definition of major surgery within a panel of expert surgeons from the European Surgical Association (ESA).

Methods

A 3‐round Delphi process was performed. All ESA members were invited to participate in the expert panel. In round 1, experts were inquired by open‐ and closed‐ended questions on potential criteria to define major surgery. Results were analyzed and presented back anonymously to the panel within next rounds. Closed‐ended questions in round 2 and 3 were either binary or statements to be rated on a Likert scale ranging from 1 (strong disagreement) to 5 (strong agreement). Participants were sent 3 reminders at 2‐week intervals for each round. 70% of agreement was considered to indicate consensus.

Results

Out of 305 ESA members, 67 (22%) answered all the 3 rounds. Significant comorbidities were the only preoperative factor retained to define major surgery (78%). Vascular clampage or organ ischemia (92%), high intraoperative blood loss (90%), high noradrenalin requirements (77%), long operative time (73%) and perioperative blood transfusion (70%) were procedure‐related factors that reached consensus. Regarding postoperative factors, systemic inflammatory response (76%) and the need for intensive or intermediate care (88%) reached consensus. Consequences of major surgery were high morbidity (>30% overall) and mortality (>2%).

Conclusion

ESA experts defined major surgery according to extent and complexity of the procedure, its pathophysiological consequences and consecutive clinical outcomes.
Assessment of climate change impact over California using dynamical downscaling with a bias correction technique: method validation and analyses of summertime results
Authors: Zhao Zhan , Di Pingkuan , Chen Shu-hua , Avise Jeremy , Kaduwela Ajith , DaMassa John
Published: March 2020

This study explores climate-change influences on future air pollution-relevant meteorological variables (e.g., temperature, wind, humidity, boundary layer heights) and atmospheric phenomena (e.g., heat wave, marine air penetration, droughts) over California by the 2050s. The Community Earth System Model simulation results from Coupled Model Intercomparison Project Phase 5 under an emission scenario that most closely aligns with California’s climate change goals were bias-corrected with respect to North American Regional Reanalysis data to reduce biases in both the climatological mean and inter-annual variations. The bias-corrected ~ 1° × 1° meteorological fields were dynamically downscaled to a resolution of 4 km × 4 km over California using the Weather Research and Forecasting model. This study focuses on summertime results, while the analysis of wintertime results will be presented in a separate paper. Our downscaled results projected a future increase of approximately 1 K in summer mean surface temperature over California under this single future climate realization. The temperature increase is larger in the nighttime than in the daytime. Water vapor mixing ratio is also projected to increase over California and off the coast. There are discernable decreases in boundary layer heights over the mountain ranges surrounding the central valley of California, while increases in boundary layer heights are observed over other regions in California. The number and duration of heat wave events are projected to increase substantially over the most populated parts of the State. The occurrence of marine air penetration events over the northern California is also projected to increase in the future.
Mutated ATP10B increases Parkinson’s disease risk by compromising lysosomal glucosylceramide export
Authors:   The BELNEU consortium, Martin Shaun , Smolders Stefanie , Van den Haute Chris , Heeman Bavo , van Veen Sarah , Crosiers David , Beletchi Igor , Verstraeten Aline , Gossye Helena , Gelders Géraldine , Pals Philippe , Hamouda Norin Nabil , Engelborghs Sebastiaan , Martin Jean-Jacques , Eggermont Jan , De Deyn Peter Paul , Cras Patrick , Baekelandt Veerle , Vangheluwe Peter , Van Broeckhoven Christine
Published: March 2020

Parkinson’s disease (PD) is a progressive neurodegenerative brain disease presenting with a variety of motor and non-motor symptoms, loss of midbrain dopaminergic neurons in the substantia nigra pars compacta and the occurrence of α-synuclein-positive Lewy bodies in surviving neurons. Here, we performed whole exome sequencing in 52 early-onset PD patients and identified 3 carriers of compound heterozygous mutations in the ATP10B P4-type ATPase gene. Genetic screening of a Belgian PD and dementia with Lewy bodies (DLB) cohort identified 4 additional compound heterozygous mutation carriers (6/617 PD patients, 0.97%; 1/226 DLB patients, 0.44%). We established that ATP10B encodes a late endo-lysosomal lipid flippase that translocates the lipids glucosylceramide (GluCer) and phosphatidylcholine (PC) towards the cytosolic membrane leaflet. The PD associated ATP10B mutants are catalytically inactive and fail to provide cellular protection against the environmental PD risk factors rotenone and manganese. In isolated cortical neurons, loss of ATP10B leads to general lysosomal dysfunction and cell death. Impaired lysosomal functionality and integrity is well known to be implicated in PD pathology and linked to multiple causal PD genes and genetic risk factors. Our results indicate that recessive loss of function mutations in ATP10B increase risk for PD by disturbed lysosomal export of GluCer and PC. Both ATP10B and glucocerebrosidase 1, encoded by the PD risk gene GBA1, reduce lysosomal GluCer levels, emerging lysosomal GluCer accumulation as a potential PD driver.
Immediate effects of water resistance therapy on patients with vocal fold mass lesions
Authors: Echternach Matthias , Raschka Julius , Kuranova Liudmila , Köberlein Marie , Richter Bernhard , Döllinger Michael , Kainz Marie-Anne
Published: March 2020

Introduction

Semi-occluded vocal tract exercises, such as water resistance therapy (WRT), are widely used in voice therapy. However, the potential positive effects of such a therapy on vocal fold oscillation patterns in patients indicating a need for phonomicrosurgery have not yet been explored. The presented study aims to analyze the effect of WRT in patients suffering from vocal fold mass lesions.

Materials and methods

Eight participants with vocal fold mass lesions were asked to sustain a phonation on the vowel /i/ at a comfortable loudness and a fundamental frequency of 250 Hz (females) or 125 Hz (males). During phonation the subjects were simultaneously recorded with transnasal high-speed videoendoscopy (HSV, 20.000 fps), electroglottography, and audio signals. These subjects then performed a WRT (phonation in a silicone tube of 30 cm length, 5 cm below the water surface) for 10 min. Repeated measurements of sustained phonation were performed 0, 10, and 30 min after exercising. From the HSV data the glottal area waveform (GAW) was segmented and GAW parameters were computed.

Results

During WRT there was an increase of the GAW related open quotient and closing quotient. Immediately after WRT, there was a drop of both values followed by a rise of these parameters up to 30 min after the intervention. Furthermore, there was no correlation between GAW and electroglottographical open quotients.

Conclusions

The effects observed after a single session of WRT on participants with vocal fold mass lesions showed a similar pattern to vocal fatigue.
Identification and profiling of microRNAs and differentially expressed genes during anther development between a genetic male-sterile mutant and its wildtype cotton via high-throughput RNA sequencing
Authors: Yu Dingwei , Li Libei , Wei Hengling , Yu Shuxun
Published: March 2020

Genetic male sterility (GMS) facilitates hybrid seed production in crops including cotton (Gossypium hirsutum). However, the genetic and molecular mechanisms specifically involved in this developmental process are poorly understood. In this study, small RNA sequencing, degradome sequencing, and transcriptome sequencing were performed to analyze miRNAs and their target genes during anther development in a GMS mutant (‘Dong A’) and its fertile wildtype (WT). A total of 80 known and 220 novel miRNAs were identified, 71 of which showed differential expressions during anther development. A further degradome sequencing revealed a total of 117 candidate target genes cleaved by 16 known and 36 novel miRNAs. Based on RNA-seq, 24, 11, and 21 predicted target genes showed expression correlations with the corresponding miRNAs at the meiosis, tetrad and uninucleate stages, respectively. In addition, a large number of differentially expressed genes were identified, most of which were involved in sucrose and starch metabolism, carbohydrate metabolism, and plant hormone signal transduction based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The results of our study provide valuable information for further functional investigations of the important miRNAs and target genes involved in genetic male sterility and advance our understanding of miRNA regulatory functions during cotton anther development.
Multivariate Analysis of Orthogonal Range Searching and Graph Distances
Authors: Bringmann Karl , Husfeldt Thore , Magnusson Måns
Published: March 2020

We show that the eccentricities, diameter, radius, and Wiener index of an undirected n-vertex graph with nonnegative edge lengths can be computed in time $$O(n\cdot \left( {\begin{array}{c}k+\lceil \log n\rceil \\ k\end{array}}\right) \cdot 2^k \log n)$$

O
(
n
·

k
+
⌈
log
n
⌉

k

·

2
k

log
n
)

, where k is linear in the treewidth of the graph. For every $$\epsilon >0$$

ϵ
>
0

, this bound is $$n^{1+\epsilon }\exp O(k)$$

n

1
+
ϵ

exp
O

(
k
)

, which matches a hardness result of Abboud et al. (in: Proceedings of the Twenty-Seventh Annual ACM-SIAM Symposium on Discrete Algorithms, 2016. 10.1137/1.9781611974331.ch28) and closes an open problem in the multivariate analysis of polynomial-time computation. To this end, we show that the analysis of an algorithm of Cabello and Knauer (Comput Geom 42:815–824, 2009. 10.1016/j.comgeo.2009.02.001) in the regime of non-constant treewidth can be improved by revisiting the analysis of orthogonal range searching, improving bounds of the form $$\log ^d n$$

log
d

n

to $$\left( {\begin{array}{c}d+\lceil \log n\rceil \\ d\end{array}}\right)$$

d
+
⌈
log
n
⌉

d

, as originally observed by Monier (J Algorithms 1:60–74, 1980. 10.1016/0196-6774(80)90005-X). We also investigate the parameterization by vertex cover number.
Mechanical and Volumetric Fracturing Behaviour of Three-Dimensional Printing Rock-like Samples Under Dynamic Loading
Authors: Zhou Tao , Zhu Jianbo , Xie Heping
Published: March 2020

Heterogeneous rock contains numerous pre-existing three-dimensional (3D) cracks, which control its mechanical and fracturing properties. Considerable effort has been devoted to studying the volumetric fracturing behaviour of rock under static loading conditions. Although rock masses are often subject to dynamic impacts such as earthquakes and blasting, the mechanical and volumetric fracturing behaviour of rock under dynamic loading is still poorly understood. In this paper, dynamic laboratory tests were performed on 3D-printed artificial rock samples with 3D embedded flaws created during three-dimensional printing (3DP), with the aim of studying the volumetric fracturing and mechanical properties of these samples under impact with high strain rate. The results show that the dynamic compressive strength and the tangent modulus decrease with an increasing number of flaws, but have very limited effects on the ratio of the fracture initiation stress of the first crack to the peak stress of the sample, the maximum axial strain of the sample and the volumetric fracturing behaviour of the sample. The tensile failure of a sample is caused by the continuous extension of wing cracks from the outer flaw tips. The mechanical and volumetric fracturing behaviour of samples with 3D embedded flaws are strain rate dependent. The tangential modulus and the ratio of the fracture initiation stress of the crack to the peak stress increase significantly when the loading type changes from static compression to dynamic compression. Under dynamic compression, wing cracks can continuously extend to the sample ends, whereas under static compression, wing cracks can intermittently extend only a limited distance. Moreover, the fracturing behaviour of 3D flaw differs from that of 2D flaws under dynamic loading. Under high strain rate loading, wing cracks generated at 3D flaw tips lead to splitting failure of the sample, while shear cracks formed at 2D flaw tips result predominant shear failure of the sample. The findings in this paper could facilitate a better understanding of rock failure subjected to dynamic loading conditions.
Statistical modeling of phenology in Bavaria based on past and future meteorological information
Authors: Ziegler Katrin , Pollinger Felix , Böll Susanne , Paeth Heiko
Published: March 2020

Plant phenology is well known to be affected by meteorology. Observed changes in the occurrence of phenological phases are commonly considered some of the most obvious effects of climate change. However, current climate models lack a representation of vegetation suitable for studying future changes in phenology itself. This study presents a statistical-dynamical modeling approach for Bavaria in southern Germany, using over 13,000 paired samples of phenological and meteorological data for analyses and climate change scenarios provided by a state-of-the-art regional climate model (RCM). Anomalies of several meteorological variables were used as predictors and phenological anomalies of the flowering date of the test plant Forsythia suspensa as predictand. Several cross-validated prediction models using various numbers and differently constructed predictors were developed, compared, and evaluated via bootstrapping. As our approach needs a small set of meteorological observations per phenological station, it allows for reliable parameter estimation and an easy transfer to other regions. The most robust and successful model comprises predictors based on mean temperature, precipitation, wind velocity, and snow depth. Its average coefficient of determination and root mean square error (RMSE) per station are 60% and ± 8.6 days, respectively. However, the prediction error strongly differs among stations. When transferred to other indicator plants, this method achieves a comparable level of predictive accuracy. Its application to two climate change scenarios reveals distinct changes for various plants and regions. The flowering date is simulated to occur between 5 and 25 days earlier at the end of the twenty-first century compared to the phenology of the reference period (1961–1990).
Fast electrodeposition of zinc onto single zinc nanoparticles
Authors: Zampardi Giorgia , Compton Richard G.
Published: March 2020

The zinc deposition reaction onto metallic zinc has been investigated at the single particle level through the electrode-particle collision method in neutral solutions, and in respect of its dependence on the applied potential and the ionic strength of a sulphate-containing solution. Depending on the concentration of sulphate ions in solution, different amounts of metallic zinc were deposited on the single Zn nanoparticles. Specifically, insights into the electron transfer kinetics at the single particles were obtained, indicating an electrically early reactant-like transition state, which is consistent with the rate-determining partial de-hydration/de-complexation process. Such information on the reaction kinetics at the nanoscale is of vital importance for the development of more efficient and long-lasting nanostructured Zn-based negative electrodes for Zn-ion battery applications.
Interactions between barotropic tides and mesoscale processes in deep ocean and shelf regions
Authors: Stanev Emil Vassilev , Ricker Marcel
Published: March 2020

The interactions between barotropic tides and mesoscale processes were studied using the results of a numerical model in which tidal forcing was turned on and off. The research area covered part of the East Atlantic Ocean, a steep continental slope, and the European Northwest Shelf. Tides affected the baroclinic fields at much smaller spatial scales than the barotropic tidal scales. Changes in the horizontal patterns of the M2 and M4 tidal constituents provided information about the two-way interactions between barotropic tides and mesoscale processes. The interaction between the atmosphere and ocean measured by the work done by wind was also affected by the barotropic tidal forcing. Tidal forcing intensified the transient processes and resulted in a substantial transformation of the wave number spectra in the transition areas from the deep ocean to the shelf. Tides flattened the sea-surface height spectra down to ~ k−2.5 power law, thus reflecting the large contribution of the processes in the high-frequency range compared to quasi-geostrophic motion. The spectra along sections parallel or normal to the continental slope differ from each other, which indicates that mesoscale turbulence was not isotropic. An analysis of the vorticity spectra showed that the flattening was mostly due to internal tides. Compared with the deep ocean, no substantial scale selectivity was observed on the shelf area. Particle tracking showed that the lengths of the Lagrangian trajectories increased by approximately 40% if the barotropic tidal forcing was activated, which contributed to changed mixing properties. The ratio between the horizontal and vertical scales of motion varied regionally depending on whether barotropic tidal forcing was included. The overall conclusion is that the barotropic tides affect substantially the diapycnal mixing.
A wideband blocker-resilient direct delta sigma receiver with selective input-impedance matching
Authors: Ul Haq Faizan , Englund Mikko , Östman Kim B. , Stadius Kari , Kosunen Marko , Koli Kimmo , Ryynänen Jussi
Published: March 2020

This paper presents a wideband blocker-tolerant direct $$\varDelta \varSigma$$ΔΣ receiver (DDSR). Blockers are attenuated through selective input impedance matching and reduced gain design. The selective input impedance profile provides a low impedance at blocker frequencies enabling blocker attenuation, while the in-band impedance is boosted to matched condition through an up-converted positive feedback from the DDSR output. In addition, with the help of reduced gain design, near band blocker gain is minimized, further improving the blocker resilience. The receiver is designed for configurable operation from 0.7–2.7 GHz and a baseband bandwidth of 10 MHz. Simulated in a 28 nm technology, the DDSR demonstrates a maximum noise figure of 6.2 dB, and achieves a peak SNDR of 53 dB with an out-of-band 1 dB input compression point of $$-\,11$$-11 dBm at a 100 MHz offset.
Depicting Dementia: Representations of Cognitive Health and Illness in Ten Picturebooks for Children
Authors: Caldwell Elizabeth F. , Falcus Sarah , Sako Katsura
Published: March 2020

It is estimated that a third of children know someone living with dementia, and there are now many picturebooks for young children that help to explain the changes dementia can bring to family life. Despite their number, there has been little examination of what these books communicate about health and illness. To address this, the current study presents a close visual and textual analysis of 10 recent picturebooks in English that aim to teach children about dementia. Our analysis reveals that in these books dementia is exclusively framed in terms of ageing, and as an illness of older adults. Furthermore, the books rely heavily on mechanistic metaphors to explain the causes of dementia. However, at the same time the “still the same person” narrative is dominant. This narrative emphasises the importance of foregrounding the unique history and personality of the person living with dementia, and offers a way to help children to continue meaningful relationships with their relatives. These books employ often ageist tropes of decline in the depiction of dementia and yet at the same time support a narrative of ongoing personhood, reflecting the complexity of broader social discourses around dementia and selfhood.
Discrete-time survival forests with Hellinger distance decision trees
Authors: Schmid Matthias , Welchowski Thomas , Wright Marvin N. , Berger Moritz
Published: March 2020

Random survival forests (RSF) are a powerful nonparametric method for building prediction models with a time-to-event outcome. RSF do not rely on the proportional hazards assumption and can be readily applied to both low- and higher-dimensional data. A remaining limitation of RSF, however, arises from the fact that the method is almost entirely focussed on continuously measured event times. This issue may become problematic in studies where time is measured on a discrete scale$$t = 1, 2, ...$$t=1,2,..., referring to time intervals$$[0,a_1), [a_1,a_2), \ldots $$[0,a1),[a1,a2),…. In this situation, the application of methods designed for continuous time-to-event data may lead to biased estimators and inaccurate predictions if discreteness is ignored. To address this issue, we develop a RSF algorithm that is specifically designed for the analysis of (possibly right-censored) discrete event times. The algorithm is based on an ensemble of discrete-time survival trees that operate on transformed versions of the original time-to-event data using tree methods for binary classification. As the outcome variable in these trees is typically highly imbalanced, our algorithm implements a node splitting strategy based on Hellinger’s distance, which is a skew-insensitive alternative to classical split criteria such as the Gini impurity. The new algorithm thus provides flexible nonparametric predictions of individual-specific discrete hazard and survival functions. Our numerical results suggest that node splitting by Hellinger’s distance improves predictive performance when compared to the Gini impurity. Furthermore, discrete-time RSF improve prediction accuracy when compared to RSF approaches treating discrete event times as continuous in situations where the number of time intervals is small.
Powering and puzzling: climate change adaptation policies in Bangladesh and India
Authors: Stock Ryan , Vij Sumit , Ishtiaque Asif
Published: March 2020

South Asia is a region uniquely vulnerable to climate-related impacts. Climate change adaptation in India and Bangladesh evolves using powering and puzzling approaches by policy actors. We seek to answer the question:how do powering and puzzling approaches influence the climate change adaptation policy design and implementation processes in Bangladesh and India?We adopted two strategies to collect and analyze data: semi-structured interviews and discourse analysis. We found that adaptation policymaking is largely top-down, amenable to techno-managerial solutions, and not inclusive of marginalized actors. In Bangladesh, power interplays among ministerial agencies impair the policy implementation process and undermine the success of puzzling. Local-scale agencies do not have enough authority or power to influence the overall implementation processes occurring at higher scales of governance. The powering of different actors in Bangladesh is visible through a duality of mandates and a lack of integration of climate adaptation strategies in different government ministries. The powering aspect of India’s various adaptation policies is the lack of collective puzzling around the question of differentiated vulnerability by axes of social difference. Paradoxically, India has a puzzling approach ofhiding behind the poorin international negotiations. Moving forward, both countries should strive to have more inclusive and equitable adaptation policymaking processes that enable the participation of marginalized populations and represent their anxieties and aspirations. Identifying policy-relevant insights from South Asia using the powering and puzzling approaches can foster adaptation policy processes that facilitate empowerment, the missing piece of the adaptation policymaking puzzle.
Predicting key educational outcomes in academic trajectories: a machine-learning approach
Authors: Musso Mariel F. , Hernández Carlos Felipe Rodríguez , Cascallar Eduardo C.
Published: March 2020

Predicting and understanding different key outcomes in a student’s academic trajectory such as grade point average, academic retention, and degree completion would allow targeted intervention programs in higher education. Most of the predictive models developed for those key outcomes have been based on traditional methodological approaches. However, these models assume linear relationships between variables and do not always yield accurate predictive classifications. On the other hand, the use of machine-learning approaches such as artificial neural networks has been very effective in the classification of various educational outcomes, overcoming the limitations of traditional methodological approaches. In this study, multilayer perceptron artificial neural network models, with a backpropagation algorithm, were developed to classify levels of grade point average, academic retention, and degree completion outcomes in a sample of 655 students from a private university. Findings showed a high level of accuracy for all the classifications. Among the predictors, learning strategies had the greatest contribution for the prediction of grade point average. Coping strategies were the best predictors for degree completion, and background information had the largest predictive weight for the identification of students who will drop out or not from the university programs.
Rewiring higher education for the Sustainable Development Goals: the case of the Intercultural University of Veracruz, Mexico
Authors: Perales Franco Cristina , McCowan Tristan
Published: March 2020

In the framework of the Sustainable Development Goals, higher education has been given a key role in addressing societal challenges, reducing poverty, ensuring sustainable livelihoods and protecting the natural environment. Yet there has been a singular lack of imagination as regards the institutional forms that might help support this vision. This article reports on the findings of an exploratory qualitative case study of the Intercultural University of Veracruz, one of a number of institutions created in Mexico to ensure access for indigenous populations, to promote local development and to provide a space for intercultural dialogue. The findings show a number of ways in which this innovative institution provides opportunities for supporting the SDGs that go beyond conventional universities. The university addresses SDG4 by enabling access for marginalised populations, and through its engaged teaching, research and community engagement also contributes to environmental protection, health, livelihoods, gender equality and a range of other goals. However, it also presents challenges to the global framework, highlighting the lack of attention to culture, language, identity and knowledge traditions, and in critiquing the very basis of its conception of development. Implications are drawn out more broadly for the relationship between higher education and international development in the contemporary era.
Custom tissue engineered aneurysm models with varying neck size and height for early stage in vitro testing of flow diverters
Authors: Villadolid Camille , Puccini Brandon , Dennis Benjamin , Gunnin Tessa , Hedigan Conor , Cardinal Kristen O’Halloran
Published: March 2020

Endovascular techniques for treating cerebral aneurysms are rapidly advancing and require testing to optimize device configurations. The purpose of this work was to customize tissue-engineered aneurysm “blood vessel mimics” (aBVMs) for early stage in vitro assessment of vascular cell responses to flow diverters and other devices. Aneurysm scaffolds with varying neck size and height were created through solid modeling, mold fabrication, mandrel creation, and electrospinning. Scaffold dimensions and fiber morphology were characterized. aBVMs were created by depositing human smooth muscle and endothelial cells within scaffolds, and cultivating within perfusion bioreactors. These vessels were left untreated or used for flow diverter implantation. Cellular responses to flow diverters were evaluated at 3 days. Custom scaffolds were created with aneurysm neck diameters of 2.3, 3.5, and 5.5 mm and with aneurysm heights of 2, 5, and 8 mm. A set of scaffolds with varying neck size was used for aBVM creation, and dual-sodding of endothelial and smooth muscle cells resulted in consistent and confluent cellular linings. Flow diverters were successfully implanted in a subset of aBVMs, and initial cell coverage over devices was seen in the parent vessel at 3 days. Direct visualization of the device over the neck region was feasible, supporting the future use of these models for evaluating and comparing flow diverter healing. Tissue-engineered aneurysm models can be created with custom neck sizes and heights, and used to evaluate cellular responses to flow diverters and other endovascular devices.
Adaptive ML-Based Frame Length Optimisation in Enterprise SD-WLANs
Authors: Coronado Estefanía , Thomas Abin , Riggio Roberto
Published: March 2020

Software-Defined Networking (SDN) is gaining a lot of traction in wireless systems with several practical implementations and numerous proposals being made. Despite instigating a shift from monolithic network architectures towards more modulated operations, automated network management requires the ability to extract, utilise and improve knowledge over time. Beyond simply scrutinizing data, Machine Learning (ML) is evolving from a simple tool applied in networking to an active component in what is known as Knowledge-Defined Networking (KDN). This work discusses the inclusion of ML techniques in the specific case of Software-Defined Wireless Local Area Networks (SD-WLANs), paying particular attention to the frame length optimization problem. With this in mind, we propose an adaptive ML-based approach for frame size selection on a per-user basis by taking into account both specific channel conditions and global performance indicators. By relying on standard frame aggregation mechanisms, the model can be seamlessly embedded into any Enterprise SD-WLAN by obtaining the data needed from the control plane, and then returning the output back to this in order to efficiently adapt the frame size to the needs of each user. Our approach has been gauged by analysing a multitude of scenarios, with the results showing an average improvement of 18.36% in goodput over standard aggregation mechanisms.
Understanding urban flood vulnerability and resilience: a case study of Kuantan, Pahang, Malaysia
Authors: Safiah Yusmah M. Y. , Bracken L. J. , Sahdan Z. , Norhaslina H. , Melasutra M. D. , Ghaffarianhoseini A. , Sumiliana S. , Shereen Farisha A. S.
Published: March 2020

Malaysia is frequently affected by the annual flooding event caused by the seasonal monsoon which accounts for significant losses. Flood risk, exposure and damage potential are increasing, causing the level of poverty and vulnerability to rise. The annual occurrence of the flood hazard has forced residents to prepare beforehand to help them spring back to their daily life faster. This study aimed to investigate and understand the vulnerability and resilience of the victims towards floods in Kuantan, Pahang. A qualitative approach of focus group discussion (FGD) is used to obtain detailed and authentic information. A total of thirty-one (31) participants who were flood victims took part in the FGD. Six groups were formed for the FGD based on different criteria such as gender, age, education background, occupation, monthly income and social class. Each FGD group consisted of four to six participants. When the participants were asked to rank their top five daily challenges, many thought that flooding is not a threat compared to food, because flooding occurs annually and is predictable. The results showed that the participants are well aware of the causes of the vulnerability faced by them due to the flooding event. Reasons highlighted from the results for the flood occurrence are the demography of the area, the location of the houses, the improper and inaccurate information and evacuation plan, the management of the transit centre and the lack of preparation by the community. The participants also thought that poor dissemination of early warning information and flood control infrastructures from the government and other related agencies caused the victims to have insufficient time to prepare for emergencies, hence causing the recovery process to be slower. However, from their hands-on experiences, they were able to put forward suggestions on the resilience towards flood for future references.
Carbon and nitrogen cycling in a lead polluted grassland evaluated using stable isotopes (δ13C and δ15N) and microbial, plant and soil parameters
Authors: Rijk Ingrid J. C. , Ekblad Alf
Published: March 2020

Aims

Carbon (C) and nitrogen (N) cycling are key ecosystem functions potentially altered by heavy metal pollution. We used an ecosystem approach to study the long-term effect of lead (Pb) on C and N cycles in a natural grassland in a former shooting range.

Methods

Microbial activity was evaluated by substrate-induced respiration (SIR) in situ,adding isotopically labelled C4-sugar to the soil. C and N contents and natural abundance of isotopes were measured in grass leaves, soil and microbial biomass together with root biomass.

Results

A reduced microbial activity and microbial biomass per area, together with a higher soil C stock and C:N ratio suggested a lower microbial decomposition in high Pb compared to low Pb areas. A more closed N cycle in the high Pb area was indicated by 2–3‰ lower δ15N in leaves and soil compared to low Pb areas. Higher δ13C in leaves and higher root biomass but similar leaf nutrient contents indicated plant responses and adaptions to the high Pb.

Conclusions

The applied ecosystem approach revealed that Pb slowed down the C and N cycles, possibly by indirect effects rather than by direct toxicity. The ecosystem seems to have adapted to altered conditions.
Capacities, Removable Sets and Lp-Uniqueness on Wiener Spaces
Authors: Hinz Michael , Kang Seunghyun
Published: March 2020

We prove the equivalence of two different types of capacities in abstract Wiener spaces. This yields a criterion for the Lp-uniqueness of the Ornstein-Uhlenbeck operator and its integer powers defined on suitable algebras of functions vanishing in a neighborhood of a given closed set Σ of zero Gaussian measure. To prove the equivalence we show the Wr,p(B,μ)-boundedness of certain smooth nonlinear truncation operators acting on potentials of nonnegative functions. We discuss connections to Gaussian Hausdorff measures. Roughly speaking, if Lp-uniqueness holds then the ‘removed’ set Σ must have sufficiently large codimension, in the case of the Ornstein-Uhlenbeck operator for instance at least 2p. For p = 2 we obtain parallel results on truncations, capacities and essential self-adjointness for Ornstein-Uhlenbeck operators with linear drift. These results apply to the time zero Gaussian free field as a prototype example.
The substituent effect of π-electron delocalization in N-methylamino-nitropyridine derivatives: crystal structure and DFT calculations
Authors: Sołtysiak Paulina , Dziuk Błażej , Zarychta Bartosz , Ejsmont Krzysztof , Spaleniak Grzegorz
Published: March 2020

The crystal and molecular structures of 3-(N-methylamino)-2-nitropyridine, 5-(N-methylamino)-2-nitropyridine and 2-(N-methylamino)-5-nitropyridine have been characterized by X-ray diffraction. To perform conformational analysis, the geometries of the compounds as well as their conformers and rotamers were optimized at the B3LYP/6-311++G(3df,3pd) level. The resulting data were used to analyze the π-electron delocalization effect in relation to the methylamino group rotation inortho-,meta-andpara-substitution positions. Quantitative aromaticity indices were calculated based on which we estimated the electronic structures of the analyzed compounds. The substituent effect of the methylamino and nitro groups was also characterized by related descriptors, i.e., charge of the Substituent Active Region (cSAR(X)) calculated based on the Hirshfeld charges and Substituent Effect Stabilization Energy (SESE). It has been shown that all the used parameters were found to be mutually interrelated with much better correlations for themeta-andpara-than theortho-derivatives. The rotation of the methylamino group relative to the aromatic fragment has an effect on the change in delocalization of the π-electrons of the pyridine ring. Relations between cSAR(NHCH3) and cSAR(NO2) show almost identical sensitivity of the substituent effect inmeta- andpara-substituted derivatives, whereas inortho-substituted analogs, different kinds of intramolecular interactions have been revealed. Furthermore, the analyzed dependency of SESE values on the torsional angle of the methylamino group indicates that an increase in the electron-attracting power of the substituent leads to a decrease in energy.
A deep-learning model for urban traffic flow prediction with traffic events mined from twitter
Authors: Essien Aniekan , Petrounias Ilias , Sampaio Pedro , Sampaio Sandra
Published: March 2020

Short-term traffic parameter forecasting is critical to modern urban traffic management and control systems. Predictive accuracy in data-driven traffic models is reduced when exposed to non-recurring or non-routine traffic events, such as accidents, road closures, and extreme weather conditions. The analytical mining of data from social networks – specifically twitter – can improve urban traffic parameter prediction by complementing traffic data with data representing events capable of disrupting regular traffic patterns reported in social media posts. This paper proposes a deep learning urban traffic prediction model that combines information extracted from tweet messages with traffic and weather information. The predictive model adopts a deep Bi-directional Long Short-Term Memory (LSTM) stacked autoencoder (SAE) architecture for multi-step traffic flow prediction trained using tweets, traffic and weather datasets. The model is evaluated on an urban road network in Greater Manchester, United Kingdom. The findings from extensive empirical analysis using real-world data demonstrate the effectiveness of the approach in improving prediction accuracy when compared to other classical/statistical and machine learning (ML) state-of-the-art models. The improvement in predictive accuracy can lead to reduced frustration for road users, cost savings for businesses, and less harm to the environment.
Changes of Technosol properties and vegetation structure along a chronosequence of dredged sediment deposition in areas with alluvial gold mining in Colombia
Authors: Betancur-Corredor Bibiana , Loaiza-Usuga Juan Carlos , Denich Manfred , Borgemeister Christian
Published: March 2020

Purpose

Alluvial gold mining leaves a vast amount of dredged sediment that covers the natural soil, destroys riparian ecosystems, and impacts riverbeds and valleys. In Colombia, more than 80,000 ha are covered by dredged sediment. Technosols developed from such deposits undergo strong transformations during the early stages of formation due to the diverse nature of the constituents. The aims of this study are (i) to investigate changes in soil morphological and physicochemical properties at early stages of pedogenesis, (ii) to estimate the variability of size structure distribution of the new plant cover as affected by the time period since establishment and deposit type, and (iii) to determine which soil parameters correlate best with the size structure distribution of vegetation.

Materials and methods

Soil characterization through morphological and physicochemical analysis was conducted on Technosols developed from gravel and sandy deposits of different ages (0–12 years). A vegetation survey was conducted to measure tree dimensions and identify the most common species. Data were analyzed using non-parametric tests to avoid the loss of information due to data smoothing.

Results and discussion

The studied Technosols are subject to processes similar to those occurring in natural parent materials such as mineral transformations, changes in redox conditions, organic matter accumulation in the topsoil, and a rapid differentiation of horizons. However, the Technosols in our study sites show an unusually fast development not often observed in natural soils, with drastic changes observed at very early stages of formation. Gravel deposits offer more favorable conditions for plant growth, and marked changes in pedogenic processes can be observed compared with sandy deposits, which are reflected in changes of chemical properties.

Conclusions

Factors such as the technology used for mining and the continuous deposition of dredged sediments in a cumulative way during the exploitation period, as well as the disturbances after deposition, result in a high diversity of constituents and high heterogeneity of dredged sediment deposits. Gravel and sand deposits, originated from the same sections of the river and after similar separation processes for ore extraction, undergo divergent pedogenic processes at different rates, which could be explained by a remarkable effect of particle size distribution. For vegetation establishment, the selection of tree species should be based on their capacity for nutrient pumping through deep rooting to sequester carbon and to adapt morphologically to heterogeneity in nutrient availability by growing roots in nutrient-rich zones.