bluuebunny/crossref_metadata_2025 huggingface dataset:
Impulsive stabilization for linear neutral‐type time‐delay systems
Authors: Chen Wu‐Hua , Lu Xiaomei , Zong Guangdeng
Published: September 2018

The problem of impulsive stabilization of linear neutral delay systems is investigated by using the impulse‐time‐dependent Lyapunov functions. The construction of impulse‐time‐dependent Lyapunov functions is based on the singular system representation of the impulsively controlled neutral delay system. In order to overcome the difficulty arising from time‐varying state delays, a Razumikhin‐type analysis method is developed and the key technique is to establish the relation between the slow and fast state variables by using a difference inequality. The derived stability criterion weakens the restriction condition on the impulse operators found in the previous result. For constant delay case, an improved stability criterion is derived by applying an impulse‐time‐dependent Lyapunov functional. Next, based on the newly established stability criteria, novel sufficient conditions on the existence of impulsive controllers with range dwell‐time constraint are presented. Finally, two numerical examples are given to demonstrate the effectiveness of the proposed results.
An efficientk‐means‐type algorithm for clustering datasets with incomplete records
Authors: Lithio Andrew , Maitra Ranjan
Published: September 2018

Thek‐means algorithm is arguably the most popular nonparametric clustering method but cannot generally be applied to datasets with incomplete records. The usual practice then is to either impute missing values under an assumed missing‐completely‐at‐random mechanism or to ignore the incomplete records, and apply the algorithm on the resulting dataset. We develop an efficient version of thek‐means algorithm that allows for clustering in the presence of incomplete records. Our extension is calledkm‐means and reduces to thek‐means algorithm when all records are complete. We also provide initialization strategies for our algorithm and methods to estimate the number of groups in the dataset. Illustrations and simulations demonstrate the efficacy of our approach in a variety of settings and patterns of missing data. Our methods are also applied to the analysis of activation images obtained from a functional magnetic resonance imaging experiment.
Roles and drivers of agribusiness shaping Climate‐Smart Landscapes: A review
Authors: Salvini Giulia , Dentoni Domenico , Ligtenberg Arend , Herold Martin , Bregt Arnold K.
Published: September 2018

The Climate‐Smart Landscape (CSL) approach has recently emerged as an integrated management strategy to address the increasing pressures on agricultural production, ecosystem conservation, rural livelihoods, and climate change mitigation/adaptation. Agribusiness companies play a controversial role in achieving CSL goals. On one hand, their operations cause land and natural resource degradation. On the other hand, they have technical, managerial, and financial resources to invest in more sustainable landscapes. Despite the controversy, empirical evidence on which practices agribusiness companies plan to undertake for sustainable landscape management and their intentions to contribute achieving CSL objectives is scarce and fragmented in the academic literature. To fill in this knowledge gap, this paper describes and reviews agribusiness companies' planned practices for integrated landscape management worldwide. Additionally, this paper evaluates to what extent companies plan to engage in two crucial factors to achieving CSL: stakeholder involvement and activities' monitoring. Results show that despite many agribusiness‐led initiatives have potential in contributing to more sustainable practices, major steps should still be taken to involve stakeholders and monitoring their process and outcomes to actually achieve CSL goals.
Toward Linux kernel memory safety
Authors: Reshetova Elena , Liljestrand Hans , Paverd Andrew , Asokan N.
Published: September 2018

The security of billions of devices worldwide depends on the security and robustness of the mainline Linux kernel. However, the increasing number of kernel‐specific vulnerabilities, especially memory safety vulnerabilities, shows that the kernel is a popular and practically exploitable target. Two major causes of memory safety vulnerabilities are reference counter overflows (temporal memory errors) and lack of pointer bounds checking (spatial memory errors). To succeed in practice, security mechanisms for critical systems like the Linux kernel must also consider performance and deployability as critical design objectives. We present and systematically analyze two such mechanisms for improving memory safety in the Linux kernel, ie, (1) an overflow‐resistant reference counter data structure designed to securely accommodate typical reference counter usage in kernel source code and (2) runtime pointer bounds checking using Intel memory protection extension in the kernel. We have implemented both mechanisms and we analyze their security, performance, and deployability. We also reflect on our experience of engaging with Linux kernel developers and successfully integrating the new reference counter data structure into the mainline Linux kernel.
Quantification of changeability level for engineering systems
Authors: Rehn Carl F. , Pettersen Sigurd S. , Garcia Jose J. , Brett Per O. , Erikstad Stein O. , Asbjørnslett Bjørn E. , Ross Adam M. , Rhodes Donna H.
Published: September 2018

This paper outlines a generic method for quantifying changeability level, to support better decision making in the early stages of design of engineering systems. Changeability represents the ability of a system to change form, function, or operation, and is a collective term for characteristics such as flexibility, adaptability, and agility. Quantification of changeability level must not be confused with valuation of changeability. The level of changeability in a design is essentially under the control of the designer. Two aspects of changeability are discussed, the first being how to structure changeable design alternatives using the Design for Changeability (DFC) variable. The DFC variable represents combinations of path enablers built into a design. Path enablers are characteristics of systems enabling them to change more easily. The second aspect is to quantify the level of changeability for a given design alternative, based on change cost and time. For the latter, we propose two measures for quantification: (1) bottom‐up, measuring the reduction of cost and time enabled for each relevant change, and (2) top‐down, measuring the span of change opportunities at given cost and time thresholds. A case study of a ship is presented to demonstrate the proposed generic method.
Mechanisms and Inhibitors of Histone Arginine Methylation
Authors: Fulton Melody D. , Brown Tyler , Zheng Y. George
Published: September 2018

Histone methylation plays an important regulatory role in chromatin restructuring and RNA transcription. Arginine methylation that is enzymatically catalyzed by the family of protein arginine methyltransferases (PRMTs) can either activate or repress gene expression depending on cellular contexts. Given the strong correlation of PRMTs with pathophysiology, great interest is seen in understanding molecular mechanisms of PRMTs in diseases and in developing potent PRMT inhibitors. Herein, we reviewed key research advances in the study of biochemical mechanisms of PRMT catalysis and their relevance to cell biology. We highlighted how a random binary, ordered ternary kinetic model for PRMT1 catalysis reconciles the literature reports and endorses a distributive mechanism that the enzyme active site utilizes for multiple turnovers of arginine methylation. We discussed the impacts of histone arginine methylation and its biochemical interplays with other key epigenetic marks. Challenges in developing small‐molecule PRMT inhibitors were also discussed.
Reading and the Development of Social Understanding: Implications for the Literacy Classroom
Authors: Kozak Stephanie , Recchia Holly
Published: September 2018

Research has underscored the cognitive benefits of reading, but scholars have also begun to explore its implications in the socioemotional domain. The authors review research exploring the links between reading and social understanding skills such as empathy and perspective taking, examine the qualities of literature that are posited to foster social understanding, and propose explanations of why reading may confer these benefits. Building on this review, the authors include ideas on how to incorporate this research into literacy classrooms by providing specific book suggestions and accompanying activities that may leverage the potential sociocognitive benefits of reading within a classroom context.
Towards predictive computer simulations in cardiology: Finite element analysis of personalized heart models
Authors: Cansız Barış , Sveric Krunoslav , Ibrahim Karim , Strasser Ruth H. , Linke Axel , Kaliske Michael
Published: September 2018

The goal of this manuscript is to demonstrate the feasibility of our recent numerical developments towards predictive computer simulations in cardiology. In contrast to existing weakly coupled and strongly coupled monolithic approaches in the literature, we utilize a fully implicit staggered solution scheme that enables to study the strong excitation‐contraction coupling of the heart tissue in the monodomain and the bidomain setting through finite element simulations. On the constitutive level, we employ the recently proposed modified Hill model (CMAME 315; 434‐466, 2017) that treats the myocardium as an electro‐visco‐active material. All the time integrations are evaluated via an implicit backward Euler scheme that ensures unconditional stability. The performance of the framework is demonstrated by means of two clinically relevant and interesting examples. Firstly, basic deformation characteristics of a personalized left ventricle model such as rotation, twist and longitudinal shortening are simulated along with a physiological pressure‐volume relation. In addition, the results of the viscoelastic and elastic solutions are compared. In the second example, we simulate a continuously beating virtual biventricle model having dyssynchrony and imitate two different cardiac resynchronization therapy attempts in order to improve the cardiac output. The corresponding electrocardiograms and left ventricle volume‐time relations are recorded during the simulation and compared to the healthy case.
4D gauge theories with conformal matter
Authors: Apruzzi Fabio , Heckman Jonathan J. , Morrison David R. , Tizzano Luigi
Published: September 2018

Abstract

One of the hallmarks of 6D superconformal field theories (SCFTs) is that on a partial tensor branch, all known theories resemble quiver gauge theories with links comprised of 6D conformal matter, a generalization of weakly coupled hypermultiplets. In this paper we construct 4D quiverlike gauge theories in which the links are obtained from compactifications of 6D conformal matter on Riemann surfaces with flavor symmetry fluxes. This includes generalizations of super QCD with exceptional gauge groups and quarks replaced by 4D conformal matter. Just as in super QCD, we find evidence for a conformal window as well as confining gauge group factors depending on the total amount of matter. We also present F-theory realizations of these field theories via elliptically fibered Calabi-Yau fourfolds. Gauge groups (and flavor symmetries) come from 7-branes wrapped on surfaces, conformal matter localizes at the intersection of pairs of 7-branes, and Yukawas between 4D conformal matter localize at points coming from triple intersections of 7-branes. Quantum corrections can also modify the classical moduli space of the F-theory model, matching expectations from effective field theory.
Three-dimensional mode selection of the flow past a rotating and inline oscillating cylinder
Authors: Lo Jacono David , Bourguet Rémi , Thompson Mark C. , Leontini Justin S.
Published: September 2018

This paper studies the transition to three-dimensional flow in the wake of a cylinder immersed in a free stream, where the cylinder is externally forced to continuously rotate about its axis and to linearly oscillate in the streamwise direction. Floquet stability analysis is used to assess the stability of the nominal two-dimensional flows at a Reynolds number

$Re=100$

and rotation rate

$\unicode[STIX]{x1D6FC}=\unicode[STIX]{x1D714}D/U=3$

to three-dimensional perturbations, as a function of the amplitude and frequency of the linear oscillations. Two modes of instability are found, distinguished by their spatial structure, temporal behaviour and apparent mechanism. The first mode has a shorter wavelength in the spanwise direction and appears to be linked to a centrifugal instability in the layer of fluid near the rotating body. The second mode has a longer wavelength and is linked to an instability of the vortex cores in the wake that is subharmonic, leading to a period doubling. Either mode can be stable while the other is unstable, depending primarily on the frequency of the oscillation of the cylinder. This indicates that either mode can control the transition to a three-dimensional flow. The results are compared to the fully three-dimensional simulation results of a rotating cylinder elastically mounted and free to oscillate in the streamwise direction from Bourguet & Lo Jacono (J. Fluid Mech., vol. 781, 2015, pp. 127–165), and appear to be able to explain the surprising switching of the observed spanwise wavelength in that flow as a change in the dominant mode, and therefore mechanism, of instability.
Active attenuation of a trailing vortex inspired by a parabolized stability analysis
Authors: Edstrand Adam M. , Sun Yiyang , Schmid Peter J. , Taira Kunihiko , Cattafesta Louis N.
Published: September 2018

Designing effective control for complex three-dimensional flow fields proves to be non-trivial. Often, intuitive control strategies lead to suboptimal control. To navigate the control space, we use a linear parabolized stability analysis to guide the design of a control scheme for a trailing vortex flow field aft of a NACA0012 half-wing at an angle of attack

$\unicode[STIX]{x1D6FC}=5^{\circ }$

and a chord-based Reynolds number

$Re=1000$

. The stability results show that the unstable mode with the smallest growth rate (fifth wake mode) provides a pathway to excite a vortex instability, whereas the principal unstable mode does not. Inspired by this finding, we perform direct numerical simulations that excite each mode with body forces matching the shape function from the stability analysis. Relative to the uncontrolled case, the controlled flows show increased attenuation of circulation and peak streamwise vorticity, with the fifth-mode-based control set-up outperforming the principal-mode-based set-up. From these results, we conclude that a rudimentary linear stability analysis can provide key insights into the underlying physics and help engineers design effective physics-based flow control strategies.
Remasculinizing the Shirker: The JewishFrontkämpferunder Hitler
Authors: Geheran Michael J.
Published: September 2018

This article examines the impact of Nazi persecution on the gender identity of German-Jewish veterans of World War I. National Socialism threatened to erase everything these Jewish men had achieved and sacrificed. It sought to destroy the identity they had constructed as soldiers in the service of the Fatherland, as well as the high status they had earned asFrontkämpfer(front-line fighters) in the Great War, upon which their sense of masculinity identity rested. Although diminished and disempowered by Nazi terror, Jewish veterans were able to orient themselves toward hegemonic ideals of martial masculinity, which elevated military values as the highest expression of manhood, giving them a space to assert themselves and defy the Nazi classificationJew. For the Jewish men who fought in World War I, the Nazi years became a battle to reclaim their status and masculine honor. They believed that the manner in which they handled themselves under the Nazis was a reflection of their character: as men who had been tried and tested in the trenches, their responses to persecution communicated their identity as soldiers, as Jews, and as Germans.
When Does the Family Govern the Family Firm?
Authors: Bøhren Øyvind , Stacescu Bogdan , Almli Line F. , Søndergaard Kathrine L.
Published: September 2018

We find that the controlling family holds both the chief executive officer and chair positions in 79% of Norwegian family firms. The family holds more governance positions when it owns large stakes in small, profitable, low-risk firms. This result suggests that the family trades off expected costs and benefits by conditioning participation intensity on observable firm characteristics. We find that the positive effect of performance on participation is twice as strong as the positive effect of participation on performance. The endogeneity of participation, therefore, should be carefully accounted for when analyzing the effect of family governance on the family firm’s behavior.
Does Option-Based Compensation Affect Payout Policy? Evidence from FAS 123R
Authors: Ferri Fabrizio , Li Nan
Published: September 2018

Does option-based compensation affect payout policy? To address this question, we examine the adoption of mandatory expensing of stock options. Our identification strategy exploits the fact that the reduction in option-based compensation after the accounting change varies with the firm-specific expected accounting impact. Across a battery of tests, we do not find that (accounting-driven) reductions in option-based pay cause dividends to increase or repurchases to decrease. Our results contrast with the widely held belief that option-based pay has a significant causal influence on payout policy and cast doubts on its role in the shift from dividends to repurchases.
Beyond not bad or just okay: social predictors of young adults’ wellbeing and functioning (a TRAILS study)
Authors: Richards J. S. , Hartman C. A. , Jeronimus B. F. , Ormel J. , Reijneveld S. A. , Veenstra R. , Verhulst F. C. , Vollebergh W. A. M. , Oldehinkel A. J.
Published: September 2018

Background

Various childhood social experiences have been reported to predict adult outcomes. However, it is unclear how different social contexts may influence each other's effects in the long run. This study examined the joint contribution of adolescent family and peer experiences to young adult wellbeing and functioning.

Methods

Participants came from the TRacking Adolescents’ Individual Lives Survey (TRAILS) study (n= 2230). We measured family and peer relations at ages 11 and 16 (i.e. family functioning, perceived parenting, peer status, peer relationship quality), and functioning as the combination of subjective wellbeing, physical and mental health, and socio-academic functioning at age 22. Using structural equation modelling, overall functioning was indicated by two latent variables for positive and negative functioning. Positive, negative and overall functioning at young adulthood were regressed on adolescent family experiences, peer experiences and interactions between the two.

Results

Family experiences during early and mid-adolescence were most predictive for later functioning; peer experiences did not independently predict functioning. Interactions between family and peer experiences showed that both protective and risk factors can have context-dependent effects, being exacerbated or overshadowed by negative experiences or buffered by positive experiences in other contexts. Overall the effect sizes were modest at best.

Conclusions

Adolescent family relations as well as the interplay with peer experiences predict young adult functioning. This emphasizes the importance of considering the relative effects of one context in relation to the other.
Hippocampal-subregion functional alterations associated with antidepressant effects and cognitive impairments of electroconvulsive therapy
Authors: Bai Tongjian , Wei Qiang , Xie Wen , Wang Anzhen , Wang Jiaojian , JI Gong-Jun , Wang Kai , Tian Yanghua
Published: September 2018

Background

Electroconvulsive therapy (ECT), an effective antidepressive treatment, is frequently accompanied by cognitive impairment (predominantly memory), usually transient and self-limited. The hippocampus is a key region involved in memory and emotion processing, and in particular, the anterior-posterior hippocampal subregions has been shown to be associated with emotion and memory. However, less is known about the relationship between hippocampal-subregion alterations following ECT and antidepressant effects or cognitive impairments.

Methods

Resting-state functional connectivity (RSFC) based on the seeds of hippocampal subregions were investigated in 45 pre- and post-ECT depressed patients. Structural connectivity between hippocampal subregions and corresponding functionally abnormal regions was also conducted using probabilistic tractography. Antidepressant effects and cognitive impairments were measured by the Hamilton Depressive Rating Scale (HDRS) and the Category Verbal Fluency Test (CVFT), respectively. Their relationships with hippocampal-subregions alterations were examined.

Results

After ECT, patients showed increased RSFC in the hippocampal emotional subregion (HIPe) with the left middle occipital gyrus (LMOG) and right medial temporal gyrus (RMTG). Decreased HDRS was associated with increased HIPe-RMTG RSFC (r = −0.316, p = 0.035) significantly and increased HIPe-LMOG RSFC at trend level (r = −0.283, p = 0.060). In contrast, the hippocampal cognitive subregion showed decreased RSFC with the bilateral angular gyrus, and was correlated with decreased CVFT (r = 0.418, p = 0.015 for left; r = 0.356, p = 0.042 for right). No significant changes were found in structural connectivity.

Conclusion

The hippocampal-subregions functional alterations may be specially associated with the antidepressant and cognitive effects of ECT.
Ambivalence, anxieties / Adaptations, advances: Conceptual History and International Law
Authors: CLARK MARTIN
Published: September 2018

Scholars of the history of international law have recently begun to wonder whether their work is predominantly about law or history. The questions we ask – about materials, contexts and movements – all raise intractable problems of historiography. Yet, few scholars have turned to historical theory to think through how we might go about addressing them.

This article works towards remedying that gap by exploring why and how we might engage with historiography more deeply.

Section 2 shows how the last three decades of the ‘turn to history’ can be usefully read as a move from ambivalence to anxiety. The major works of the 2000s thoroughly removed the pre-1990s ambivalence to history, offering brief considerations about method. Recent efforts building on those works have led to the present era of anxiety about both history and method, raising questions around materials, contexts and movements. But far from a negative state, this moment of anxiety is both appropriate and potentially creative: it prompts us to rethink our mode of engaging with historiography.

Section 3 explores how this engagement might proceed. It reconstructs the principles and debates within conceptual history around the anxieties of materials, contexts and movements. It then explores how these might be adapted to histories of international law, both generally and within one concrete project: a conceptual history of recognition in the writings of British jurists.

Section 4 concludes by considering the advances achieved by this kind of engagement, and reflects on new directions for international law and its histories.
Towards a Postcolonial Genealogy of International Organizations Law
Authors: SINCLAIR GUY FITI
Published: September 2018

This article sketches the contours of a postcolonial genealogy of international organizations law. Contrary to conventional accounts, which remain strongly Eurocentric, the article claims that international organizations law did not emerge until the closing stages of the Second World War, and that its evolution was strongly influenced by the accelerating processes of decolonization that accompanied its birth. More specifically, the article argues that the emergence of international organizations law was spurred by a series of perceived problems regarding the adequacy of the international legal system in the aftermath of the end of formal colonial rule, in which the relations of power constructed through colonialism remained profoundly implicated. The politics of decolonization thus shaped the practice of international organizations, provided the catalyst for many of the foundational cases in international organizations law, and motivated much of its early doctrinal scholarship. Moreover, the article argues that the functionalist logic of international organizations law is deeply embedded in a postcolonial imaginary which, by supporting the division of the world into formally equivalent nation-states, ostensibly cuts against the hegemonic territorialism of colonial governance.
Metastable transitions in inertial Langevin systems: What can be different from the overdamped case?
Authors: SOUZA ANDRE N. , TAO MOLEI
Published: September 2018

Metastable transitions in Langevin dynamics can exhibit rich behaviours that are markedly different from its overdamped limit. In addition to local alterations of the transition path geometry, more fundamental global changes may exist. For instance, when the dissipation is weak, heteroclinic connections that exist in the overdamped limit do not necessarily have a counterpart in the Langevin system, potentially leading to different transition rates. Furthermore, when the friction coefficient depends on the velocity, the overdamped limit no longer exists, but it is still possible to efficiently find instantons. The approach, we employed for these discoveries, was based on (i) a simple rewriting of the Freidlin–Wentzell action in terms of time-reversed dynamics and (ii) an adaptation of the string method, which was originally designed for gradient systems, to this specific non-gradient system.
Stability of aqueous formaldehyde under γ irradiation: prebiotic relevance
Authors: López-Islas A. , Colín-García M. , Negrón-Mendoza A.
Published: September 2018

Formaldehyde is a precursor of sugars, which are compounds essential in all forms of life and a necessary molecule for prebiotic processes. This work focuses on evaluating the stability of formaldehyde exposed to a high radiation field simulating prebiotic conditions on primitive Earth, such as the ocean or shallow waters. Formaldehyde may have been formed from reactions in the atmosphere and from rainout processes reached water bodies. In our experiments, we employed γ radiation and found that formaldehyde was labile towards radiation and decomposed even at low irradiation doses due to the fact that aldehyde/hydrate groups present in formaldehyde structure are very reactive under irradiation. However, after exposing this molecule to several doses of irradiation, we detected the formation of formic acid and glycolaldehyde – both of which are of prebiotic interest. We also observed formaldehyde regeneration by one of its radiolytic products: formic acid.
Extractable and Germinable Seedbank Methods Provide Different Quantifications of Weed Communities
Authors: Reinhardt Theresa , Leon Ramon G.
Published: September 2018

Seedbank sampling and quantification methods vary in their ability to describe weed diversity and density, so proper method selection is critical for studying weed communities. The germinable seedbank (GSB) method is commonly preferred over extractable seedbank method (ESB), because the latter is more time-consuming. However, these two methods have only been compared using a few weed species and a relatively small number of samples. A total of 204 weed seedbank samples were used to compare both methods for weed density, richness, evenness, and Shannon-Weiner diversity using a split-sample approach. The two methods yielded dramatically different results. The ESB had 418% higher density and 35% more species per sample but 11% less evenness than the GSB. Diversity was estimated to be only 9% higher using the extractable compared with the germinable method. While the extractable method had higher density and richness overall, this was not true for every species, with only 7 of 14 common species detected in higher amounts by the extractable method. The results indicate the two methods are not strongly correlated, limiting the possibility of generating a conversion factor between methods. Nevertheless, evenness and Shannon-Weiner diversity might allow comparisons between both methods when the emphasis is on characterizing predominant weed species. The GSB is a practical approach to compare treatments or conditions; however, the ESB is more useful to accurately quantify weed species richness, diversity, and density.
CME: Fusobacterium nucleatum/naviforme – eine seltene, aber nicht zu unterschätzende Ursache für pyogene Leberabszesse
Authors: Rifaat Mario , Depmeier Carsten , Jeger Victor , Schneemann Markus , Anagnostopoulos Alexia
Published: September 2018

Zusammenfassung. Pyogene Leberabszesse gehören zu den häufigsten abdominellen Infektionen. Als Ursache können neben den häufigsten Erregern auch seltenere Keime wie Fusobakterien, die auch in der natürlichen oropharyngealen und enteralen Flora vorkommen können, eine Rolle spielen. Weil sich dieser Keim diagnostisch schwieriger isolieren lässt, kann eine Infektion mit diesen selteneren Erregern und deren Therapie eine Herausforderung darstellen.
Magenbypass: Abnehmen mit Komplikationen
Authors: Nucera Maria , Mahanty Mark , Eigenmann Franz , Nocito Antonio
Published: September 2018

Zusammenfassung. Der Roux-Y-Magenbypass (RYGBP) stellt weltweit die am häufigsten durchgeführte bariatrische Operation dar – innere Hernien zählen zu den wichtigsten Langzeitkomplikationen. Unser Bericht einer 30-jährigen Patientin beschreibt erstmalig einen Fall einer ischämisch bedingten Dünndarmstenose nach RYGBP. Bei der Erstvorstellung wurden eine Petersen- und eine Brolin-Hernie diagnostiziert und laparoskopisch erfolgreich verschlossen. Der minderperfundierte Dünndarmanteil erholte sich in der Folge gut. Die Zweitvorstellung folgte eine Woche darauf bei postprandialem Erbrechen aufgrund postischämischer Dünndarmstenosen. Diese wurden mittels Ballondilatation erfolgreich behandelt.
Technologische Innovationen in der Diabetes-Therapie
Authors: Strey Christopher
Published: September 2018

Zusammenfassung. Über die vergangenen Jahre hat eine wahre Flut an technologischen Innovationen die Behandlungsmöglichkeiten für Menschen mit Diabetes mellitus drastisch erweitert. Die kapilläre Blutzuckermessung wird nach und nach durch die kontinuierliche Glukosemessung ersetzt. Immer mehr Insulinpumpen-Systeme werden an kontinuierliche Glukosemessung gekoppelt und dadurch zunehmend selbstregulierend. Neue ultra-lang und -kurz wirksame Insuline sind erhältlich. Für mehrere anti-diabetische Wirkstoffgruppen, die bisher injiziert werden mussten, gibt es bald orale Alternativen.
Limited Role of Working Time Shift in Offsetting the Increasing Occupational‐Health Cost of Heat Exposure
Authors: Takakura Jun'ya , Fujimori Shinichiro , Takahashi Kiyoshi , Hasegawa Tomoko , Honda Yasushi , Hanasaki Naota , Hijioka Yasuaki , Masui Toshihiko
Published: September 2018

Climate change increases workers' exposure to heat stress. To prevent heat‐related illnesses, according to occupational‐health recommendations, labor capacity must be reduced. However, this preventive measure is expected to be costly, and the costs are likely to rise as the scale and scope of climate change impacts increase over time. Shifting the start of the working day to earlier in the morning could be an effective adaptation measure for avoiding the impacts of labor capacity reduction. However, the plausibility and efficacy of such an intervention have never been quantitatively assessed. Here we investigate whether working time shifts can offset the economic impacts of labor capacity reduction due to climate change. Incorporating a temporally (1 hr) and spatially (0.5° × 0.5°) high‐resolution heat exposure index into an integrated assessment model, we calculated the working time shift necessary to offset labor capacity reduction and economic loss under hypothetical with‐ and without‐realistic‐adaptation scenarios. The results of a normative scenario analysis indicated that a global average shift of 5.7 (4.0–6.1) hours is required, assuming extreme climate conditions in the 2090s. Although a realistic (<3 hr) shift nearly halves the economic cost, a substantial cost corresponding to 1.6% (1.0–2.4%) of global total gross domestic product is expected to remain. In contrast, if stringent climate‐change mitigation is achieved, a realistic shift limits the remaining cost to 0.14% (0.12–0.47%) of global total gross domestic product. Although shifting working time is shown to be effective as an adaptation measure, climate‐change mitigation remains indispensable to minimize the impact.
Variation in Plasmaspheric Hiss Wave Power With Plasma Density
Authors: Malaspina David M. , Ripoll Jean‐Francois , Chu Xiangning , Hospodarsky George , Wygant John
Published: September 2018

Plasmaspheric hiss waves are commonly observed in the inner magnetosphere. These waves efficiently scatter electrons, facilitating their precipitation into the atmosphere. Predictive inner magnetosphere simulations often model hiss waves using parameterized empirical maps of observed hiss power. These maps nearly always include parameterization by magnetic L value. In this work, data from the Van Allen Probes are used to compare variation in hiss wave power with variation in both L value and cold plasma density. It is found that for L> 2.5, plasmaspheric hiss wave power increases with plasma density. For L> 3, this increase is stronger and occurs regardless of L value and for all local times. This result suggests that the current paradigm for parameterizing hiss wave power in many magnetospheric simulations may need to be revisited and that a new parameterization in terms of plasma density rather than L value should be explored.
Eolianite Grain Size Distributions as a Proxy for Large Changes in Planetary Atmospheric Density
Authors: Goosmann Erik A. , Catling David C. , Som Sanjoy M. , Altermann Wladyslaw , Buick Roger
Published: September 2018

Atmospheres are dynamic over geologic timescales, making large changes in planetary air density possible. For the Earth, geological proxies suggest that air density in the Neoarchean was similar to or lower than today. This air density variation possibly affected eolian dune grain sizes by controlling the trajectories of grains though the air. Balancing the fall velocity and threshold friction velocity, a metric separating saltation and suspension transport, suggests that a lower air density could increase the mean grain size of dunes because decreased air drag extends the size range of grains in modified saltation and incipient suspension regimes. Consequently, the dune‐forming sand left behind in pure saltation, the dominant dune‐forming transport mode, could have coarser grains. We analyzed size distributions of two eolianites from 2.64 and 1.5 Ga (billion years ago) for deviations from modern sand dunes emplaced at sea level, which globally exhibit similar mean grain sizes. Both aeolianites have mean grain sizes within one standard deviation of the modern mean and are not statistically separable at 95% confidence. Overall, this suggests that while air density is important in eolian physics, a factor of 2 to 4 change in density is insufficient to produce an unambiguous grain size signal. This suggests that while eolian dune grain sizes have not significantly changed over the range of Earth's atmospheric conditions, they could be useful when investigating the order of magnitude changes thought to have occurred on Mars.
Thinning Can Reduce Losses in Carbon Use Efficiency and Carbon Stocks in Managed Forests Under Warmer Climate
Authors: Collalti Alessio , Trotta Carlo , Keenan Trevor F. , Ibrom Andreas , Bond‐Lamberty Ben , Grote Ruediger , Vicca Sara , Reyer Christopher P. O. , Migliavacca Mirco , Veroustraete Frank , Anav Alessandro , Campioli Matteo , Scoccimarro Enrico , Šigut Ladislav , Grieco Elisa , Cescatti Alessandro , Matteucci Giorgio
Published: September 2018

Forest carbon use efficiency (CUE, the ratio of net to gross primary productivity) represents the fraction of photosynthesis that is not used for plant respiration. Although important, it is often neglected in climate change impact analyses. Here we assess the potential impact of thinning on projected carbon cycle dynamics and implications for forest CUE and its components (i.e., gross and net primary productivity and plant respiration), as well as on forest biomass production. Using a detailed process‐based forest ecosystem model forced by climate outputs of five Earth System Models under four representative climate scenarios, we investigate the sensitivity of the projected future changes in the autotrophic carbon budget of three representative European forests. We focus on changes in CUE and carbon stocks as a result of warming, rising atmospheric CO2 concentration, and forest thinning. Results show that autotrophic carbon sequestration decreases with forest development, and the decrease is faster with warming and in unthinned forests. This suggests that the combined impacts of climate change and changing CO2 concentrations lead the forests to grow faster, mature earlier, and also die younger. In addition, we show that under future climate conditions, forest thinning could mitigate the decrease in CUE, increase carbon allocation into more recalcitrant woody pools, and reduce physiological‐climate‐induced mortality risks. Altogether, our results show that thinning can improve the efficacy of forest‐based mitigation strategies and should be carefully considered within a portfolio of mitigation options.
Multiscale Framework for Modeling Multicomponent Reactive Transport in Stream Corridors
Authors: Painter S. L.
Published: September 2018

Travel time‐based representations of transport, a highly successful strategy for modeling conservative tracer transport in stream corridors, are extended to accommodate multicomponent reactive transport. Specifically, convolution representations used to model exchange of solute with the hyporheic zone are shown to be equivalent to solving one‐dimensional subgrid models in Lagrangian form coupled to the advection dispersion equation for the stream channel. Unlike the convolution‐based representations of previous travel time‐based stream transport models, the subgrid model generalizes to include multicomponent reactive transport with general nonlinear reactions. An example involving biomass growth, the establishment of redox zonation, and the resulting impact on denitrification rates demonstrate reach‐scale application of the new approach. Although simplified, those example simulations show some of the key phenomena associated with hyporheic zone denitrification that are not represented with conventional first‐order estimates.
Climate Controls on Runoff and Low Flows in Mountain Catchments of Western North America
Authors: Dierauer Jennifer R. , Whitfield Paul H. , Allen Diana M.
Published: September 2018

In the mountainous regions of western North America, snowmelt recharges groundwater and provides ecosystem‐sustaining base flow during low‐flow periods. Continued warming is expected to have large impacts on snowmelt hydrology and on low‐flow regimes, but the relative impact of temperature and precipitation on low flows is unclear. To address this knowledge gap, the dominant climate controls on summer and winter season low flows in 63 near‐natural catchments in mountainous ecoregions of western North America are identified with correlation analysis, and low‐flow sensitivity to temperature and precipitation is quantified with multiple linear regression analysis. Results show that precipitation is the dominant control on the interannual variability of annual runoff and on the duration and severity of summer and winter low flows. The temperature sensitivity of low flows, however, can be as much as twice that of annual runoff. Warm winters correspond to significantly lower runoff; significantly longer, more severe summer low flows; and significantly shorter winter low flows. This highlights the importance of winter climate conditions for runoff and low flows in these mountain catchments and provides another line of evidence regarding the impacts of climate change on snowmelt hydrology.
Identifying Wetland Consolidation Using Remote Sensing in the North Dakota Prairie Pothole Region
Authors: Krapu Christopher , Kumar Mukesh , Borsuk Mark
Published: September 2018

Artificial drainage of wetlands in the Great Plains has been linked to increased runoff, erosion, and the consolidation of small, seasonal wetlands into larger, more permanent bodies of water. We analyzed hydrologic changes to over 1.2 million water bodies across the entire North Dakota portion of the Prairie Pothole Region using the ratio of aggregate water area and total perimetric length in a landscape‐scale shape index calculated from existing Landsat derived data of water presence/absence. This ratio showed a clear change point toward more consolidation of wetlands around the period 1999 (±1 year) after an extended multiyear period of above‐average rainfall. We used hydrologic simulations with forcing data from across the region to show that this shift is unlikely to be due solely to natural variation in precipitation and evapotranspiration. Using county‐level regressions, we found that wetland consolidation as measured by the shape index was highly correlated with agricultural transitions out of wheat and into corn and soybeans over the period 1984–2014 (R2 > 0.4), though we do not find evidence of a strong correlation between reported drainage and wetland consolidation. These results highlight a potential hysteretic interaction involving interannual variations in hydrologic forcing and anthropogenic landscape alterations on wetland consolidation in the North Dakota prairie potholes.
Effects of Forest Roads on Runoff Initiation in Low‐Order Ephemeral Streams
Authors: Ramos‐Scharrón C. E. , LaFevor M. C.
Published: September 2018

Understanding hydrologic connectivity is essential for managing ephemeral headwater streams where upstream land use influences downstream aquatic habitats. This study relies on a field‐based approach to evaluate how precipitation and roads affect runoff generation in low‐order ephemeral streams of the U.S. Virgin Islands. Logistic regression analyses show that runoff delivery from unroaded catchments agrees with a water storage conceptual model typical for subsurface storm and saturation overland flow‐dominated settings. Without roads, runoff occurs only about 4 times per year in response to 10 and 78 mm of storm rainfall, depending on antecedent precipitation. In contrast, maximum 15‐min rainfall intensities are a better predictor of runoff generation on unpaved roads than are total rainfall and antecedent conditions. Intensities surpassing ~10 mm/hr lead to road runoff, and this occurs about 40 times per year. Road‐influenced streams represent an intermediate setting for which runoff generation depends on storm and antecedent rainfall, as well as the road surface area captured by drains and flow path distance. In our focus area, roads can provoke streams to deliver runoff to coral bearing waters 10 to 13 times every year as a response to 9.3‐ to 50‐mm storms, depending on antecedent rainfall and road drain characteristics. These results highlight the sensitivity of road connectivity to specific road drain characteristics and display the potential for connectivity as a guiding watershed restoration principle.
The novel immunoglobulin super family receptor SLAMF9 identified in TAM of murine and human melanoma influences pro-inflammatory cytokine secretion and migration
Authors: Dollt Claudia , Michel Julia , Kloss Loreen , Melchers Susanne , Schledzewski Kai , Becker Kathrin , Sauer Andrea , Krewer Andreas , Koll Franziska , Schmieder Astrid
Published: September 2018

Melanoma is a highly immunogenic tumor with a good response to treatment with immune checkpoint inhibitors. Tumor-associated macrophages (TAMs) play an important immunosuppressive role in such tumors and have therefore been identified as possible future therapeutic targets in oncology. The aim of this study was to identify novel immunoregulatory receptors specifically expressed on TAM. Expression of Slamf9, a member of the signaling lymphocytic-activating molecule (Slam) immunoreceptor family, was found to be upregulated in a gene expression analysis of murine bone marrow-derived macrophages (BMDM) stimulated with tumor-conditioned medium of B16F1 melanoma cells. SLAMF9+ macrophages were identified in human and murine melanomas by using self-generated antibodies against human and murine SLAMF9. A comprehensive immunohistochemical analysis of tissue microarrays detected SLAMF9+ TAM in 73.3% of human melanomas, but also in 95.5% of naevi of melanoma patients and in 50% of naevi from healthy controls. In addition, 20% of melanomas and 2.3% of naevi from melanoma patients displayed a positive SLAMF9 expression also in melanocytic cells. No SLAMF9 expression was detected in naevus cells of healthy donors. Although SLAMF9 has no intracellular signaling motif, a comprehensive functional analysis revealed that the molecule was able to significantly enhance TNF-α secretion after LPS-stimulation. In addition, SLAMF9 delayed the wound closure of RAW 264.7 cells in a scratch assay, while proliferation and cell death were not affected. Taken together, SLAMF9 is a novel type-I-transmembrane receptor with immunomodulatory properties in macrophages. Further studies are required to evaluate whether SLAMF9 classifies as a promising future therapeutic target in melanoma.
Loss of PRC1 induces higher-order opening of Hox loci independently of transcription during Drosophila embryogenesis
Authors: Cheutin Thierry , Cavalli Giacomo
Published: September 2018

Polycomb-group proteins are conserved chromatin factors that maintain the silencing of key developmental genes, notably the Hox gene clusters, outside of their expression domains. Depletion of Polycomb repressive complex 1 (PRC1) proteins typically results in chromatin unfolding, as well as ectopic transcription. To disentangle these two phenomena, here we analyze the temporal function of two PRC1 proteins, Polyhomeotic (Ph) and Polycomb (Pc), on Hox gene clusters during Drosophila embryogenesis. We show that the absence of Ph or Pc affects the higher-order chromatin folding of Hox clusters prior to ectopic Hox gene transcription, demonstrating that PRC1 primary function during early embryogenesis is to compact its target chromatin. Moreover, the differential effects of Ph and Pc on Hox cluster folding match the differences in ectopic Hox gene expression observed in these two mutants. Our data suggest that PRC1 maintains gene silencing by folding chromatin domains and impose architectural layer to gene regulation.
Cortical modulation of sensory flow during active touch in the rat whisker system
Authors: Chakrabarti Shubhodeep , Schwarz Cornelius
Published: September 2018

Sensory gating, where responses to stimuli during sensor motion are reduced in amplitude, is a hallmark of active sensing systems. In the rodent whisker system, sensory gating has been described only at the thalamic and cortical stages of sensory processing. However, does sensory gating originate at an even earlier synaptic level? Most importantly, is sensory gating under top-down or bottom-up control? To address these questions, we used an active touch task in behaving rodents while recording from the trigeminal sensory nuclei. First, we show that sensory gating occurs in the brainstem at the first synaptic level. Second, we demonstrate that sensory gating is pathway-specific, present in the lemniscal but not in the extralemniscal stream. Third, using cortical lesions resulting in the complete abolition of sensory gating, we demonstrate its cortical dependence. Fourth, we show accompanying decreases in whisking-related activity, which could be the putative gating signal.