bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining optical and radar satellite image time series to map natural vegetation: savannas as an example
Authors: Lopes Mailys , Frison Pierre‐Louis , Durant Sarah M. , Schulte to Bühne Henrike , Ipavec Audrey , Lapeyre Vincent , Pettorelli Nathalie
Published: January 2020

Up‐to‐date land cover maps are important for biodiversity monitoring as they are central to habitat and ecosystem distribution assessments. Satellite remote sensing is a key technology for generating these maps. Until recently, land cover mapping has been limited to static approaches, which have primarily led to the production of either global maps at coarse spatial resolutions or geographically restricted maps at high spatial resolutions. The recent availability of optical (Sentinel‐2) and radar (Sentinel‐1) satellite image time series (SITS) which provide access to high spatial and very high temporal resolutions, is a game changer, offering opportunities to map land cover using both temporal and spatial information. These data moreover open interesting perspectives for land cover mapping based on data combination approach. However, the usefulness of combining dense time series (more than 30 images per year) and data combination approaches to map natural vegetation has so far not been assessed. To address this gap, this contribution tests the idea that the combined consideration of optical and radar data combination and time series analyses can significantly improve natural vegetation mapping in the Pendjari National Park, a Sahelian savanna protected area in Benin. Results highlight that the combination of Sentinel‐1 and Sentinel‐2 SITS performs as well as Sentinel‐2 SITS alone in terms of classification accuracy. Land cover maps are however qualitatively better when considering the data combination approach. Our results also clearly show that the use of dense/hypertemporal optical time series significantly improves classification outcomes compared to using multitemporal only a few images per year) or monotemporal data. Altogether, this work thus demonstrates the ability of dense SITS to improve discrimination of natural vegetation types using information on their phenology, leading to more detailed and more reliable maps for environmental management.
Students' adherences to epistemic understanding in evaluating scientific claims
Authors: Leung Jessica Shuk Ching
Published: January 2020

Epistemic understanding of science is essential for critical evaluation of scientific claims. In principle, developing students' epistemic understanding would enhance students' capability in evaluating scientific claims. However, findings on this “expected” connection have been inconclusive. This paper seeks to examine this discrepancy between epistemic understanding in theory, and the practical application of this understanding. It uses the concept of adherence from the literature on conceptual change when accounting for this discrepancy. Questionnaires were used to examine adherences to epistemic understanding in evaluating health‐related claims by 42 college‐level nonscience majors. Follow‐up interviews were conducted to explain their adherences to epistemic understanding during their evaluation. The analysis revealed that: (a) Students tended to adhere to process of inquiry much stronger than the nature of scientific knowledge and the social context of science. (b) Students' low adherence to the nature of scientific findings and generation process was found to relate to an interplay among various epistemic aspects of science. (c) Students demonstrated low adherence in practicing epistemic understanding due to difference in contexts between giving declarative statements about science and using epistemic understanding to evaluate scientific claims. These findings have theoretical implications on the discrepancy between theory and practice in relation to the role of epistemic understanding of science, and on what constitutes informed epistemic understanding. They also have practical implications in terms of enhancing students' adherences to epistemic understanding in evaluating scientific claims.
Critical science agency and power hierarchies: Restructuring power within groups to address injustice beyond them
Authors: Schenkel Kathleen , Calabrese Barton Angela
Published: January 2020

Promoting critical science agency (CSA) may be one way to promote educational justice. CSA is using science with other powerful forms of knowledge to address issues of injustice. However, the process of enacting CSA is always embedded within a sociopolitical context, which positions some students with more power than others. Drawing upon a social practice theory analytical lens with a focus on power and using critical participatory ethnography methods, this study investigated the ways middle school students restructured power hierarchies as they worked to complete the design challenge of making their classroom community more sustainable, and how power hierarchy restructuring impacted students' opportunities to enact CSA. Findings show as the students enacted collective CSA, they were responding to unmet students' needs grounded in systems of power operating within their classroom. Throughout the engineering design process, students' understandings of their defined issue of injustice was both refined and critical to their technical and social design considerations. Finally, as the groups enacted CSA, power hierarchy disruptions, though incomplete, through the recognition of students' expertize and distributing roles, supported their efforts to address their class‐wide concerns. These findings highlight how restructuring power hierarchies supported youth enacting collective CSA, which then further supported them in reshaping their classroom community to be more justice‐oriented.
The (Un) intended consequences of institutions lowering barriers to entrepreneurship: The impact on female workers
Authors: Castellaneta Francesco , Conti Raffaele , Kacperczyk Aleksandra
Published: January 2020

We propose that institutions that reduce barriers to entrepreneurship lead to intended consequences, increasing entry rate among individuals facing obstacles to entrepreneurship, such as women. But these regulations also have unintended consequences, decreasing the value appropriated by women who stay in paid employment, as these women lose support of their departing peers. Using an exogenous reduction in entry barriers in Portugal between 2005 and 2009, we find that women launch new ventures at higher rates than men, when entry barriers fall, but the same changes lead to a relative decline in women's wages in paid employment. These effects are amplified for women in managerial positions, who benefit if they leave but lose if they stay. Our study contributes to a nuanced understanding of rent‐allocation in firms.

Managerial Summary

We study the unintended consequences of lowering barriers to entry—an important institutional change to foster entrepreneurship, especially among those facing strongest entry barriers. We examine the effects of such regulations on women departing to entrepreneurship and those staying in incumbent firms, using the registry data from Portugal. The results show that lowering entry barriers leads to higher rates of entrepreneurial entry among women, as intended. But we also find that this deregulation reform results in a wider gender pay gap among those who stay in incumbent firms. We attribute these increases to reductions in bargaining power and productivity, which result from the departure of socially‐proximate peers. Finally, these intended and unintended consequences are especially common among female managers—who are more likely to leave for entrepreneurship, on the one hand, but also more likely to witness greater pay gaps in wage work, on the other hand.
Serving differently: CEO regulatory focus and firm stakeholder strategy
Authors: Gamache Daniel L , Neville François , Bundy Jonathan , Short Cole E
Published: January 2020

Research summary

A fundamental question in stakeholder strategy research is why firms adopt certain strategies or approaches to engage with key stakeholders. Recent research suggests that CEOs' characteristics can influence their general decisions to engage with stakeholders, however, this work has yet to consider why CEOs might utilize specific stakeholder strategies. In this article, we demonstrate how CEO regulatory focus influences the nature of a firm's stakeholder strategy. Specifically, we argue that CEO prevention focus is positively associated with engagement in governance‐oriented initiatives and receptivity to governance‐oriented stakeholder activism, while CEO promotion focus is positively associated with engagement in socially‐oriented initiatives and receptivity to socially‐oriented stakeholder activism. We find strong support for our hypotheses in a sample of 374 publicly‐traded firms.

Managerial summary

The strategies a firm uses to engage with stakeholders can influence its performance, yet little is known about what makes firms focus on certain stakeholders over others. To better understand this, we examined CEO regulatory focus in a sample of large public companies. Our findings reveal that the way CEOs view decisions—either based on a sense of duty, obligations, and responsibility or as a means to achieve high ideals—influences their tendency to prioritize shareholder concerns or the concerns of a broader array of stakeholders. This suggests that executives should be aware of their own natural tendencies to inject their motivations into their firm's stakeholder strategy and consider avenues to balance their perspectives for the sake of the firm.
Mind the gap: The role of gender in entrepreneurial career choice and social influence by founders
Authors: Rocha Vera , van Praag Mirjam
Published: January 2020

Research summary

Women continue to be disproportionately underrepresented in new venture creation. We investigate whether and how founders can differently influence future entrepreneurial career choices of their male and female joiners. Using a large sample of startup firms with personnel where founders interact closely with joiners, we demonstrate that founders have a strong influence on a joiner's entrepreneurial career choice if both are female. We find empirical support for role modeling as a key underlying mechanism, accounting for alternative explanations such as selective matching based on gender and push‐driven factors. These findings increase our understanding of the roles of socialization and organizational context in shaping the career outcomes of employees, and provide evidence of a multiplier effect of female entrepreneurs.

Managerial summary

Women are less likely to be entrepreneurs than men. We investigate whether working in a startup founded by a woman instead of a man influences individuals' decision to become an entrepreneur later. We find this to be the case for women. This result is best explained by female founders acting as role models for their female employees in male‐dominated domains. Female founders able to break gender stereotypes seem to have an influence on the career choices of their female employees, especially among those who have lacked contact with entrepreneurs. Moreover, this influence is stronger if the female founder and employee have similar backgrounds. These findings confirm the importance of social interactions at work and suggest new ways to inspire more women to launch startups.
Effect of the Deformation Amount on the Microstructure and Tensile Properties of 304 Stainless Steel with 2 wt% Al Content by Cold Rolling
Authors: Guo Xin , La Peiqing , Li Heng , Wei Yupeng , Lu Xuefeng
Published: January 2020

The microstructure evolution during cold rolling and mechanical properties after solution treatment of 304 stainless steel with 2 wt% Al are investigated and the tensile properties of the steels are also tested. The results show that the steel consists of ferrite and austenite phases and small amounts of granular precipitates of Al4C3 and AlN, and the content of ferrite decreases gradually with increase of the deformation. For deformations of 30%, 50%, and 70%, the average grain sizes of the samples are 10.23, 8.66, and 7.13 μm, respectively. After solution treatment grain refinement is obvious for the <101> orientation and a large number of annealing twin grain boundaries are observed in the austenite phase. The sample with 50% deformation contains the highest volume fraction of recrystallized grains. The {001}<100> cube texture and {001}<110> rotated cube texture are present in the ferrite and austenite phases. The yield strength of the steel increases gradually with the increase in the cold rolling reduction; meanwhile the elongations are all above 40%. Especially for the sample with the reduction of 70%, the yield strength of the solution‐treated specimen is 417 MPa, and the elongation is ≈50%.
Effects of Physiological Condition on Aspects of Repeat Spawning in Female Steelhead Reconditioned in Captivity
Authors: Jenkins Laura E. , Pierce Andrew L. , Caudill Christopher C. , Graham Neil D. , Medeiros Lea R. , Hatch Douglas R. , Nagler James J.
Published: January 2020

Physiological condition (hereafter shortened to “condition”) influences survival, spawning schedules, and reproductive effort in salmonids. In iteroparous females, the effects of first spawning on condition could result in trade‐offs with future reproduction, mediated by postspawning survival, repeat spawning schedule (i.e., consecutive or skip spawning), or reproductive effort. However, which aspects of condition affect these outcomes and when they are sensitive to condition are not well understood. These issues were examined in highly energy‐depleted hatchery‐origin female summer steelhead Oncorhynchus mykiss that were undergoing postspawning reconditioning in captivity. Measures of condition and reproductive characteristics (i.e., fecundity, egg size, and total egg mass [TEM]) at first spawning were examined for their effects on postspawning survival and future spawning schedules, and condition was tracked during reconditioning to examine effects on reproductive characteristics at repeat spawning. The levels of plasma osmolality and triglycerides measured at first spawning were positively correlated with survival probability, suggesting that survival depends on the ability to maintain homeostasis and access stored energy. Surprisingly, size‐standardized TEM measured at first spawning was positively correlated with the probability of consecutive spawning, providing no support for the hypothesized trade‐off between current and future reproduction. This finding instead suggests that both first‐spawning reproductive effort and consecutive spawning may be influenced by condition at earlier points. Plasma triglycerides and growth rates at sampling points 10–20 weeks after first spawning were strongly correlated with size‐standardized egg size and TEM at consecutive spawning, suggesting that reproductive effort and its allocation to egg size and fecundity depend on energetic status during early oogenesis. These results indicate that condition influences survival, repeat spawning schedules, and reproductive characteristics in female steelhead up to a year or more before repeat spawning. If more broadly applicable, these relationships could provide insight into the mechanisms that link environmental conditions with reproductive characteristics in salmonids and other species.
Maximum thermodynamic power coefficient of a wind turbine
Authors: Tavares J. M. , Patrício P.
Published: January 2020

According to the centenary Betz‐Joukowsky law, the power extracted from a wind turbine in open flow cannot exceed 16/27 of the wind transported kinetic energy rate. This limit is usually interpreted as an absolute theoretical upper bound for the power coefficient of all wind turbines, but it was derived in the special case of incompressible fluids. Following the same steps of Betz classical derivation, we model the turbine as an actuator disk in a one dimensional fluid flow but consider the general case of a compressible reversible fluid, such as air. In doing so, we are obliged to use not only the laws of mechanics but also and explicitly the laws of thermodynamics. We show that the power coefficient depends on the inlet wind Mach number
, and that its maximum value exceeds the Betz‐Joukowsky limit. We have developed a series expansion for the maximum power coefficient in powers of the Mach number
that unifies all the cases (compressible and incompressible) in the same simple expression:
.
Infrared and transcendental structure of two-loop supersymmetric QCD amplitudes
Authors: Kälin Gregor , Mogull Gustav , Ochirov Alexander , Verbeek Bram
Published: January 2020

Abstract

Using a careful choice of infrared (IR) subtraction scheme, we demonstrate cancellation of all terms with transcendental weights 0, 1, 2 from the finite part of the full-color two-loop four-gluon

$$ \mathcal{N} $$

N

= 2 supersymmetric QCD amplitude, with N

f
massless supersymmetric quarks. This generalizes the previously observed cancellation of weight-2 terms in the superconformal theory, where N

f
= 2N

c
for gauge group SU(N

c
). The subtraction scheme follows naturally both from general IR factorization principles and from an integrand-level analysis of divergences in this amplitude. The divergences are written in terms of scalar triangle integrals whose expressions are known to all orders in the dimensional regulator ϵ = (4 − D)/2. We also present integrated expressions for the full-color two-loop four-point amplitudes with both matter and vectors on external legs in which lower-weight terms also cancel using an appropriate IR scheme. This provides us with values for the two-loop cusp, gluonic, and quark anomalous dimensions in

$$ \mathcal{N} $$

N

= 2 supersymmetric QCD, which are cross-checked between the three different amplitudes.
Phenomenology of keV scale sterile neutrino dark matter with S4 flavor symmetry
Authors: Gautam Nayana , Das Mrinal Kumar
Published: January 2020

Abstract

We study the possibility of simultaneously addressing neutrino phenomenology and the dark matter in the framework of inverse seesaw. The model is the extension of the standard model by the addition of two right handed neutrinos and three sterile fermions which leads to a light sterile state with the mass in the keV range along with three light active neutrino states. The lightest sterile neutrino can account for a feasible dark matter (DM) candidate. We present a S
4 flavor symmetric model which is further augmented by Z
4 × Z
3 symmetry to constrain the Yukawa Lagrangian. The structures of the mass matrices involved in inverse seesaw within the S
4 framework naturally give rise to correct neutrino mass matrix with non-zero reactor mixing angle θ
13. In this framework, we conduct a detailed numerical analysis both for normal hierarchy as well as inverted hierarchy to obtain dark matter mass and DM-active mixing which are the key factors for considering sterile neutrino as a viable dark matter candidate. We constrain the parameter space of the model from the latest cosmological bounds on the mass of the dark matter and DM-active mixing.
Properties of the new $$ \mathcal{N} $$ = 1 AdS4 vacuum of maximal supergravity
Authors: Bobev Nikolay , Fischbacher Thomas , Pilch Krzysztof
Published: January 2020

Abstract

The recent comprehensive numerical study of critical points of the scalar potential of four-dimensional

$$ \mathcal{N} $$

N

= 8, SO(8) gauged supergravity using Machine Learning software in [1] has led to a discovery of a new

$$ \mathcal{N} $$

N

= 1 vacuum with a triality-invariant SO(3) symmetry. Guided by the numerical data for that point, we obtain a consistent SO(3) × ℤ2-invariant truncation of the

$$ \mathcal{N} $$

N

= 8 theory to an

$$ \mathcal{N} $$

N

= 1 supergravity with three chiral multiplets. Critical points of the truncated scalar potential include both the

$$ \mathcal{N} $$

N

= 1 point as well as two new non-supersymmetric and perturbatively unstable points not found by previous searches. Studying the structure of the submanifold of SO(3) × ℤ2-invariant supergravity scalars, we find that it has a simple interpretation as a submanifold of the 14-dimensional

$$ {\mathbb{Z}}_2^3 $$

ℤ
2
3

-invariant scalar manifold (SU(1, 1)/U(1))7, for which we find a rather remarkable superpotential whose structure matches the single bit error correcting (7, 4) Hamming code. This 14-dimensional scalar manifold contains approximately one quarter of the known critical points. We also show that there exists a smooth supersymmetric domain wall which interpolates between the new

$$ \mathcal{N} $$

N

= 1 AdS4 solution and the maximally supersymmetric AdS4 vacuum. Using holography, this result indicates the existence of an

$$ \mathcal{N} $$

N

= 1 RG flow from the ABJM SCFT to a new strongly interacting conformal fixed point in the IR.
Higher-form symmetries, Bethe vacua, and the 3d-3d correspondence
Authors: Eckhard Julius , Kim Heeyeon , Schäfer-Nameki Sakura , Willett Brian
Published: January 2020

Abstract

By incorporating higher-form symmetries, we propose a refined definition of the theories obtained by compactification of the 6d (2, 0) theory on a three-manifold M
3. This generalization is applicable to both the 3d

$$ \mathcal{N} $$

N

= 2 and

$$ \mathcal{N} $$

N

= 1 supersymmetric reductions. An observable that is sensitive to the higher-form symmetries is the Witten index, which can be computed by counting solutions to a set of Bethe equations that are determined by M
3. This is carried out in detail for M
3 a Seifert manifold, where we compute a refined version of the Witten index. In the context of the 3d-3d correspondence, we complement this analysis in the dual topological theory, and determine the refined counting of flat connections on M
3, which matches the Witten index computation that takes the higher-form symmetries into account.
Chaotic dynamics of string around charged black brane with hyperscaling violation
Authors: Ma Da-Zhu , Zhang Dan , Fu Guoyang , Wu Jian-Pin
Published: January 2020

Abstract

By fast Lyapunov indicator (FLI), we study the chaotic dynamics of closed string around charged black brane with hyperscaling violation (HV). The Hawking temperature, Lifshitz dynamical exponent and HV exponent together affect the chaotic dynamics of this system. The temperature plays the role of driving the closed string to escape to infinity. There is a threshold value z

∗
= 2, below which the string is captured by the black brane no matter where the string is placed at the beginning. However, when z > 2, the string escapes to infinity if it is placed near the black brane at the beginning, but if the initial position of string is far away from the black brane, it oscillates around the black brane till eternity, which is a quasi-periodic motion. HV exponent plays the role of driving the string falling into the black brane. With the increase of HV exponent θ, the falling velocity becomes faster. We find that when we heat the system with large HV exponent, the chaotic system does not essentially changes. It indicates that the HV exponent plays a very important role in determining the state of the chaotic system. Also we study the effect from the winding number of the string. The study indicates that the chaotic dynamics of the string is insensitive to the winding number.
Searches for other vacua. Part II. A new Higgstory at the cosmological collider
Authors: Hook Anson , Huang Junwu , Racco Davide
Published: January 2020

Abstract

The detection of an oscillating pattern in the bispectrum of density perturbations could suggest the existence of a high-energy second minimum in the Higgs potential. If the Higgs field resided in this new minimum during inflation and was brought back to the electroweak vacuum by thermal corrections during reheating, the coupling of Standard Model particles to the inflaton would leave its imprint on the bispectrum. We focus on the fermions, whose dispersion relation can be modified by the coupling to the inflaton, leading to an enhanced particle production during inflation even if their mass during inflation is larger than the Hubble scale. This results in a large non-analytic contribution to non-Gaussianities, with an amplitude f
NL as large as 100 in the squeezed limit, potentially detectable in future 21-cm surveys. Measuring the contributions from two fermions would allow us to compute the ratio of their masses, and to ascribe the origin of the signal to a new Higgs minimum. Such a discovery would be a tremendous step towards understanding the vacuum instability of the Higgs potential, and could have fascinating implications for anthropic considerations.
Correlators of the symmetric product orbifold
Authors: Dei Andrea , Eberhardt Lorenz
Published: January 2020

Abstract

We exploit null vectors of the fractional Virasoro algebra of the symmetric product orbifold to compute correlation functions of twist fields in the large N limit. This yields a new method to derive correlation functions in these orbifold CFTs that is purely based on the symmetry algebra. We explore various generalisations, such as subleading (torus) contributions or correlation functions of other fields than the bare twist fields. We comment on the consequences of our computation for the AdS3
/CFT2 correspondence.
Generic invariant measures for iterated systems of interval homeomorphisms
Authors: Czernous Wojciech , Szarek Tomasz
Published: January 2020

It is well known that iterated function systems generated by orientation preserving homeomorphisms of the unit interval with positive Lyapunov exponents at its ends admit a unique invariant measure on (0, 1) provided their action is minimal. With the additional requirement of continuous differentiability of maps on a fixed neighbourhood of $$\{0,1\}$${0,1}, we present a metric in the space of such systems which renders it complete. Using then a classical argument (and an alternative uniqueness proof), we show that almost singular invariant measures are admitted by systems lying densely in the space. This allows us to construct a residual set of systems with unique singular stationary distribution. Dichotomy between singular and absolutely continuous unique measures is assured by taking a subspace of systems with absolutely continuous maps; the closure of this subspace is where the residual set is found.
Epigenetic histone modulation contributes to improvements in inflammatory bowel disease via EBI3
Authors: Wetzel Alexandra , Scholtka Bettina , Gerecke Christian , Kleuser Burkhard
Published: January 2020

Ulcerative colitis (UC) is characterized by relapsing–remitting inflammatory episodes paralleled by varying cytokine levels, suggesting that switching epigenetic processes might be involved. However, the epigenetic impact on cytokine levels in colitis is mostly unexplored. The heterodimeric interleukin (IL)-12 cytokine family have various functions in both pro- and anti-inflammatory processes. The family member IL-35 (EBI3/IL-12p35) was recently reported to play an anti-inflammatory role in UC. Therefore, we aimed to investigate a possible epigenetic regulation of the IL-35 subunits in vitro and in vivo, and to examine the epigenetic targeting of EBI3 expression as a therapeutic option for UC. Exposure to either the pro-inflammatory TNFα or to histone deacetylase inhibitors (HDACi) significantly increased EBI3 expression in Human Colon Epithelial Cells (HCEC) generated from healthy tissue. When applied in combination, a drastic upregulation of EBI3 expression occurred, suggesting a synergistic mechanism. Consequently, IL-35 was increased as well. In vivo, the intestines of HDACi-treated wild-type mice exhibited reduced pathological signs of colitis compared to non-treated colitic mice. However, the improvement by HDACi treatment was completely lost in Ebi3-deficient mice (Ebi3−/−). In fact, HDACi appeared to exacerbate the disease phenotype in Ebi3−/−. In conclusion, our results reveal that under inflammatory conditions, EBI3 is upregulated by the epigenetic mechanism of histone acetylation. The in vivo data show that the deficiency of EBI3 plays a key role in colitis manifestation. Concordantly, our data suggest that conditions promoting histone acetylation, such as upon HDACi application, improve colitis by a mechanism involving the local formation of the anti-inflammatory cytokine IL-35.
Reductions in body sway responses to a rhythmic support surface tilt perturbation can be caused by other mechanisms than prediction
Authors: Assländer Lorenz , Gruber Markus , Giboin Louis-Solal
Published: January 2020

Studies investigating balance control often use external perturbations to probe the system. These perturbations can be administered as randomized, pseudo-randomized, or predictable sequences. As predictability of a given perturbation can affect balance performance, the way those perturbations are constructed may affect the results of the experiments. In the present study, we hypothesized that subjects are able to adapt to short, rhythmic support surface tilt stimuli, but not to long pseudo-random stimuli. 19 subjects were standing with eyes closed on a servo-controlled platform tilting about the ankle joint axis. Pre and post to the learning intervention, pseudo-random tilt sequences were applied. For the learning phase, a rhythmic and easy-to-memorize 8-s long sequence was applied 75 times, where subjects were instructed to stand as still as possible. Body kinematics were measured and whole body center of mass sway was analyzed. Results showed reduced sway and less forward lean of the body across the learning phase. The sway reductions were similar for stimulus and non-stimulus frequencies. Surprisingly, for the pseudo-random sequences, comparable changes were found from pre- to post-tests. In summary, results confirmed that considerable adaptations exist when exposing subjects to an 8-s long rhythmic perturbation. No indications of predictions of the learning tilt sequence were found, since similar changes were also observed in response to pseudo-random sequences. We conclude that changes in body sway responses following 75 repetitions of an 8-s long rhythmic tilt sequence are due to adaptations in the dynamics of the control mechanism (presumably stiffness).
Immune biological rationales for the design of combined radio- and immunotherapies
Authors: Hader Michael , Frey Benjamin , Fietkau Rainer , Hecht Markus , Gaipl Udo S.
Published: January 2020

Cancer immunotherapies are promising treatments for many forms of cancer. Nevertheless, the response rates to, e.g., immune checkpoint inhibitors (ICI), are still in low double-digit percentage. This calls for further therapy optimization that should take into account combination of immunotherapies with classical tumor therapies such as radiotherapy. By designing multimodal approaches, immune modulatory properties of certain radiation schemes, additional immune modulation by immunotherapy with ICI and hyperthermia, as well as patient stratification based on genetic and immune constitutions have to be considered. In this context, both the tumor and its microenvironment including cells of the innate and adaptive immune system have to be viewed in synopsis. Knowledge of immune activation and immune suppression by radiation is the basis for well-elaborated addition of certain immunotherapies. In this review, the focus is set on additional immune stimulation by hyperthermia and restoration of an immune response by ICI. The impact of radiation dose and fractionation on immune modulation in multimodal settings has to be considered, as the dynamics of the immune response and the timing between radiotherapy and immunotherapy. Another big challenge is the patient stratification that should be based on matrices of biomarkers, taking into account genetics, proteomics, radiomics, and “immunomics”. One key aim is to turn immunological “cold” tumors into “hot” tumors, and to eliminate barriers of immune-suppressed or immune-excluded tumors. Comprehensive knowledge of immune alterations induced by radiation and immunotherapy when being applied together should be utilized for patient-adapted treatment planning and testing of innovative tumor therapies within clinical trials.
The semi-automated algorithm for the detection of bone marrow oedema lesions in patients with axial spondyloarthritis
Authors: Kucybała Iwona , Tabor Zbisław , Polak Jakub , Urbanik Andrzej , Wojciechowski Wadim
Published: January 2020

The aim of the study was to create the efficient tool for semi-automated detection of bone marrow oedema lesions in patients with axial spondyloarthritis (axSpA). MRI examinations of 22 sacroiliac joints of patients with confirmed axSpA-related sacroiliitis (median SPARCC score: 14 points) were included into the study. Design of our algorithm is based on Maksymowych et al. evaluation method and consists of the following steps: manual segmentation of bones (T1W sequence), automated detection of reference signal region, sacroiliac joint central lines and ROIs, a division of ROIs into quadrants, automated detection of inflammatory changes (STIR sequence). As a gold standard, two sets of manual lesion delineations were created. Two approaches to the performance assessment of lesion detection were considered: pixel-wise (detections compared pixel by pixel) and quadrant-wise (quadrant to quadrant). Statistical analysis was performed using Spearman's correlation coefficient. Correlation coefficient obtained for pixel-wise comparison of semi-automated and manual detections was 0.87 (p = 0.001), while for quadrant-wise analysis was 0.83 (p = 0.001). The correlation between two sets of manual detections was 0.91 for pixel-wise comparison (p = 0.001) and 0.88 (p = 0.001) for quadrant-wise approach. Spearman’s correlation between two manual assessments was not statistically different from the correlation between semi-automated and manual evaluations, both for pixel- (p = 0.14) and quadrant-wise (p = 0.17) analysis. Average single slice processing time: 0.64 ± 0.30 s. Our method allows for objective detection of bone marrow oedema lesions in patients with axSpA. The quantification of affected pixels and quadrants has comparable reliability to manual assessment.
Partitioning Infinite Hypergraphs into Few Monochromatic Berge-Paths
Authors: Bustamante Sebastián , Corsten Jan , Frankl Nóra
Published: January 2020

Extending a result of Rado to hypergraphs, we prove that for all $$s, k, t \in {\mathbb {N}}$$s,k,t∈N with $$k \ge t \ge 2$$k≥t≥2, the vertices of every $$r = s(k-t+1)$$r=s(k-t+1)-edge-coloured countably infinite complete k-graph can be partitioned into the cores of at most s monochromatic t-tight Berge-paths of different colours. We further describe a construction showing that this result is best possible.
The 2018 Kerala floods: a climate change perspective
Authors: Hunt Kieran M. R. , Menon Arathy
Published: January 2020

In August 2018, the Indian state of Kerala received an extended period of very heavy rainfall as a result of a low-pressure system near the beginning of the month being followed several days later by a monsoon depression. The resulting floods killed over 400 people and displaced a million more. Here, a high resolution setup (4 km) of the Weather Research and Forecasting (WRF) model is used in conjunction with a hydrological model (WRF-Hydro, run at 125 m resolution) to explore the circumstances that caused the floods. In addition to a control experiment, two additional experiments are performed by perturbing the boundary conditions to simulate the event in pre-industrial and RCP8.5 background climates. Modelled rainfall closely matched observations over the study period, and it is found that this would this would have been about 18% heavier in the pre-industrial due to recent weakening of monsoon low-pressure systems, but would be 36% heavier in an RCP8.5 climate due to moistening of the tropical troposphere. Modelled river streamflow responds accordingly: it is shown the six major reservoirs that serve the state would have needed to have 34% more capacity to handle the heavy rainfall, and 43% had the deluge been amplified by an RCP8.5 climate. It is further shown that this future climate would have significantly extended the southern boundary of the flooding. Thus it is concluded that while climate change to date may well have mitigated the impacts of the flooding, future climate change would likely exacerbate them.
Consistency of extreme temperature changes in China under a historical half-degree warming increment across different reanalysis and observational datasets
Authors: Zhao Siyao , Zhou Tianjun , Chen Xiaolong
Published: January 2020

The extreme temperature changes under a 0.5 °C global mean surface temperature warming increment is of great importance for climate change adaption and risk management on post-Paris-Agreement agenda. The impacts of the already happened 0.5 °C warming increment on extreme temperature can serve as essential references for the 1.5/2 °C projections. Quantifying the observed changes of climate extremes is hampered by the limitation of observational datasets in both spatial coverage and temporal continuity. The reanalysis datasets are hoped to be useful substitutes for the observations, but their performance over continental China remains unknown. In this study, we compare the extreme temperature changes associated with the past 0.5 °C warming derived from three reanalysis datasets including JRA-55, ERA and 20CR with the observation in China. Distinct increases (decreases) in warm (cold) extremes are detected in all three reanalyses in a spatially aggregated perspective as in the observation. On regional scales the reanalyses have evident spreads in regions with insufficient observational coverage such as the western China. JRA-55 shows good agreement with the observation in both spatial patterns and magnitudes of extreme temperature changes. Both ERA and 20CR show weaker consistency with the observation, particularly in western China, mainly due to less observational constraints in data assimilation. The different aerosol data used in reanalysis assimilation systems also influenced the data quality. Our results indicate that while the reanalyses can serve as useful substitutes to fill in the observational gaps, cautious should be taken in regions with sparse observations and large anthropogenic aerosol emissions.
Correction to: A nonsynonymous mutation in PLCG2 reduces the risk of Alzheimer’s disease, dementia with Lewy bodies and frontotemporal dementia, and increases the likelihood of longevity
Authors:   DESGESCO (Dementia Genetics Spanish Consortium), van der Lee Sven J. ,   EADB (Alzheimer Disease European DNA biobank),   IFGC (International FTD-Genomics Consortium),   IPDGC (The International Parkinson Disease Genomics Consortium),   RiMod-FTD (Risk and Modifying factors in Fronto-Temporal Dementia),   Netherlands Brain Bank (NBB),   The GIFT (Genetic Investigation in Frontotemporal Dementia and Alzheimer’s Disease) Study Group, Conway Olivia J. , Jansen Iris , Carrasquillo Minerva M. , Kleineidam Luca , van den Akker Erik , Hernández Isabel , van Eijk Kristel R. , Stringa Najada , Chen Jason A. , Zettergren Anna , Andlauer Till F. M. , Diez-Fairen Monica , Simon-Sanchez Javier , Lleó Alberto , Zetterberg Henrik , Nygaard Marianne , Blauwendraat Cornelis , Savage Jeanne E. , Mengel-From Jonas , Moreno-Grau Sonia , Wagner Michael , Fortea Juan , Keogh Michael J. , Blennow Kaj , Skoog Ingmar , Friese Manuel A. , Pletnikova Olga , Zulaica Miren , Lage Carmen , de Rojas Itziar , Riedel-Heller Steffi , Illán-Gala Ignacio , Wei Wei , Jeune Bernard , Orellana Adelina , Then Bergh Florian , Wang Xue , Hulsman Marc , Beker Nina , Tesi Niccolo , Morris Christopher M. , Indakoetxea Begoña , Collij Lyduine E. , Scherer Martin , Morenas-Rodríguez Estrella , Ironside James W. , van Berckel Bart N. M. , Alcolea Daniel , Wiendl Heinz , Strickland Samantha L. , Pastor Pau , Rodríguez Rodríguez Eloy , Boeve Bradley F. , Petersen Ronald C. , Ferman Tanis J. , van Gerpen Jay A. , Reinders Marcel J. T. , Uitti Ryan J. , Tárraga Lluís , Maier Wolfgang , Dols-Icardo Oriol , Kawalia Amit , Dalmasso Maria Carolina , Boada Mercè , Zettl Uwe K. , van Schoor Natasja M. , Beekman Marian , Allen Mariet , Masliah Eliezer , de Munain Adolfo López , Pantelyat Alexander , Wszolek Zbigniew K. , Ross Owen A. , Dickson Dennis W. , Graff-Radford Neill R. , Knopman David , Rademakers Rosa , Lemstra Afina W. , Pijnenburg Yolande A. L. , Scheltens Philip , Gasser Thomas , Chinnery Patrick F , Hemmer Bernhard , Huisman Martijn A. , Troncoso Juan , Moreno Fermin , Nohr Ellen A. , Sørensen Thorkild I. A. , Heutink Peter , Sánchez-Juan Pascual , Posthuma Danielle , Clarimón Jordi , Christensen Kaare , Ertekin-Taner Nilüfer , Scholz Sonja W. , Ramirez Alfredo , Ruiz Agustín , Slagboom Eline , van der Flier Wiesje M. , Holstege Henne
Published: January 2020

The IPDGC (The International Parkinson Disease Genomics Consortium) and EADB (Alzheimer Disease European DNA biobank) are listed correctly as an author to the article, however, they were incorrectly listed more than once.
Cases of asphyxia in children and adolescents: a retrospective analysis of fatal accidents, suicides, and homicides from 1998 to 2017 in Hamburg, Germany
Authors: Mosek Dieu Phuong , Sperhake Jan Peter , Edler Carolin , Püschel Klaus , Schröder Ann Sophie
Published: January 2020

Purpose

Injury-related asphyxia is one of the most common causes of death in children in Germany. However, only a few systematic studies have analyzed the causes and circumstances of asphyxia in children and adolescents.

Methods

All cases of asphyxia in children and adolescents (0–21 years of age) among the Hamburg Legal Medical Department’s autopsy cases from 1998 to 2017 were retrospectively analyzed with special focus on how often external findings were completely absent.

Results

Among 249 cases of fatal asphyxia, 68% were accidents, 14% were suicides, and 13% were homicides. Most of the cases involved boys. Adolescents and young adults aged 15–21 years represented the main age group. Drowning was the leading mechanism of asphyxia. Younger age was associated with less frequent detection of external signs of asphyxia in the postmortem external examination. Petechial hemorrhages were the most common visible external indication of asphyxia. No external findings indicative of asphyxia were present in 14% of the cases.

Conclusion

Asphyxia in children and adolescents often involves accidents. However, postmortem external examination alone is insufficient to identify asphyxia and the manner of death.
Single mean arterial blood pressure drops during stroke thrombectomy under general anaesthesia are associated with poor outcome
Authors: Fandler-Höfler Simon , Heschl Stefan , Argüelles-Delgado Placido , Kneihsl Markus , Hassler Eva , Magyar Marton , Kainz Andreas , Berghold Andrea , Niederkorn Kurt , Deutschmann Hannes , Fazekas Franz , Gattringer Thomas
Published: January 2020

Background

We examined the influence of periprocedural blood pressure (BP), especially critical BP drops, on 3-month functional outcome in stroke patients undergoing mechanical thrombectomy (MT) under general anaesthesia (GA).

Methods

We screened all patients with anterior circulation large vessel occlusion receiving MT under GA at our centre from January 2011 to June 2016 and selected those who had continuous invasive periinterventional BP monitoring. Clinical and radiological data were prospectively collected as part of an ongoing cohort study, monitoring data were extracted from electronic anaesthesia records. We used uni- and multivariable regression to investigate the association of BP values with unfavourable outcome, defined as modified Rankin Scale scores 3–6 3 months post-stroke.

Results

115 patients were included in this study (mean age 65.3 ± 13.0 years, 55.7% male). Periinterventional systolic, diastolic, and mean arterial BP (MAP) values averaged across MT had no effect on outcome. However, single BP drops were related to unfavourable outcome, with absolute MAP drops showing the highest association compared to both systolic and relative BP drops (with reference to pre-interventional values). The BP value with the strongest association with unfavourable outcome was identified as an MAP ever < 60 mmHg (p = 0.01) with a pronounced effect in patients with poor collaterals. An MAP < 60 mmHg remained independently associated with poor functional outcome in multivariable analysis (p < 0.01).

Conclusions

For patients undergoing MT under GA, single MAP drops < 60 mmHg are independently related to unfavourable 3-month outcome. Therefore, every effort should be made to prevent periinterventional hypotensive episodes, especially below this threshold.
Establishing metrics and control laws for the learning process: ball and beam balancing
Authors: Buza Gergely , Milton John , Bencsik Laszlo , Insperger Tamas
Published: January 2020

Understanding how dexterity improves with practice is a fundamental challenge of motor control and neurorehabilitation. Here we investigate a ball and beam implementation of a dexterity puzzle in which subjects stabilize a ball at the mid-point of a beam by manipulating the angular position of the beam. Stabilizability analysis of different biomechanical models for the ball and beam task with time-delayed proportional-derivative feedback identified the angular position of the beam as the manipulated variable. Consequently, we monitored the changes in the dynamics with learning by measuring changes in the control parameters. Two types of stable motion are possible: node type (nonoscillatory) and spiral type (oscillatory). Both types of motion are observed experimentally and correspond to well-defined regions in the parameter space of the control gains. With practice the control gains for each subject move close to or on the portion of the boundary which separates the node-type and spiral-type solutions and which is associated with the rightmost characteristic exponent of smallest real part. These observations suggest that with learning the control gains for ball and beam balancing change in such a way that minimizes overshoot and the settling time. This study provides an example of how mathematical analysis together with careful experimental observations can shed light onto the early stages of skill acquisition. Since the difficulty of this task depends on the length of the beam, ball and beam balancing tasks may be useful for the rehabilitation of children with dyspraxia and those recovering from a stroke.