bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Comparison of UTC- and PIN-Photodiodes for Continuous-Wave Terahertz Generation
Authors: Nellen S. , Ishibashi T. , Deninger A. , Kohlhaas R. B. , Liebermeister L. , Schell M. , Globisch B.
Published: December 2019

We carried out an experimental comparison study of the two most established optoelectronic emitters for continuous-wave (cw) terahertz generation: a uni-traveling-carrier photodiode (UTC-PD) and a pin-photodiode (PIN-PD). Both diodes are commercially available and feature a similar package (fiber-pigtailed housings with a hyper-hemispherical silicon lens). We measured the terahertz output as a function of optical illumination power and bias voltage from 50 GHz up to 1 THz, using a precisely calibrated terahertz power detector. We found that both emitters were comparable in their spectral power under the operating conditions specified by the manufacturers. While the PIN-PD turned out to be more robust against varying operating parameters, the UTC-PD showed no saturation of the emitted terahertz power even for 50 mW optical input power. In addition, we compared the terahertz transmission and infrared (IR) blocking ratio of four different filter materials. These filters are a prerequisite for correct measurements of the absolute terahertz power with thermal detectors.
From the Neolithic to the Bronze Age in Central Italy: Settlement, Burial, and Social Change at the Dawn of Metal Production
Authors: Dolfini Andrea
Published: December 2019

The Late Neolithic and Copper Age were a time of change in most of Europe. Technological innovations including animal traction, the wheel, and plow agriculture transformed the prehistoric economy. The discovery of copper metallurgy expanded the spectrum of socially significant materials and realigned exchange networks away from Neolithic “greenstone,” obsidian, andSpondylusshells. New funerary practices also emerged, signifying the growing importance of lineage ancestors, as well as new ideas of personal identity. These phenomena have long attracted researchers’ attention in continental Europe and the British Isles, but comparatively little has been done in the Italian peninsula. Building on recent discoveries and interdisciplinary research on settlement patterns, the subsistence economy, the exchange of socially valuable materials, the emergence of metallurgy, funerary practices, and notions of the body, I critically appraise current models of the Neolithic-Bronze Age transition in light of the Italian regional evidence, focusing on central Italy. In contrast to prior interpretations of this period as the cradle of Bronze Age social inequality and the prestige goods economy, I argue that, at this juncture, prehistoric society reconfigured burial practices into powerful new media for cultural communication and employed new materials and objects as novel identity markers. Stratified political elites may not be among the new identities that emerged at this time in the social landscape of prehistoric Italy.
The many meanings of organic farming: framing food security and food sovereignty in Indonesia
Authors: Schreer Viola , Padmanabhan Martina
Published: December 2019

This paper contributes to the discourse on food policy, particularly in relation to organic farming in Indonesia. Organic farming was first adopted by non-state actors in Indonesia, by faith-based organisations and then by small farmer associations, while the state support for organic agriculture followed at a later date. The three groups, represented in this study by three case studies, adopt different positions with regard to the definition of organic agriculture and its relevance to food self-sufficiency, food security and food sovereignty. For Bina Sarana Bhakti Foundation (BSB), organic farming is both a spiritual worldview and a practical philosophy. For the Indonesian Peasant Union (SPI), organic agriculture foremost is a political tool to resist global capitalist agriculture. Despite their very different outlooks, both these two civil society organisations see organic agriculture as a post-materialist enterprise directed towards explicitly social-political goals. By contrast, the government’s engagement in organic agriculture, although laced with evocative phrases such as “back to nature”, is driven primarily by visions of developing a new niche market for Indonesian exports. The Indonesian State adopts a one-dimensional productivist definition that excludes different meanings and traditions of organic farming. The reduction of the meaning of ‘organic’ to ‘organically certified products’ excludes farmers who consider that they are practicing organic agriculture. We conclude that there is a strong case to be made that the State should relax its regulatory grip on the organic sector, to create room for sorely needed innovation and cooperation among the different actors involved.
Numerical evaluation of turbulent flow in a circular conduit along a side weir
Authors: Bagherifar Meysam , Emdadi Ayoub , Azimi Hamed , Sanahmadi Babak , Shabanlou Saeid
Published: December 2019

Side weir is used as a slot in the side wall of the main channel to direct excess water that is above the weir crest. Such structures are used in control of flow level in irrigation, drainage networks and urban sewage disposal systems. Furthermore, circular channels are pretty important because considerable length of sewage disposal and transmission pipeline system is made of circular channels. In this study, changes inflow free surface, turbulence and flow field passing through a circular channel along a side weir are simulated. This means that for modeling the variations in flow free surface and the flow field turbulence, the volume-of-fluid scheme and RNG k–ε turbulence model are used, respectively. In order to validate the accuracy of the numerical model, the flow free surface changes along the side weir, the discharge coefficient of side weir, discharge of side weir, Froude number at upstream of the side weir and specific energy are compared with the experimental measurements. Comparison of simulation results with the experimental measurements shows high accuracy of CFD model. In other words, the root-mean-square error percent and the mean absolute error for flow free surface are, respectively, obtained to be 0.554% and 0.547%. Moreover, average difference between the specific energy at upstream and downstream of the side weir is calculated about 2.1%. The main purpose of this simulation is gaining an understanding of behavior of the passing flow through circular channels with side weir for subcritical flow regime.
Weighted estimates for operator-valued Fourier multipliers
Authors: Fackler Stephan , Hytönen Tuomas P. , Lindemulder Nick
Published: December 2019

We establish Littlewood–Paley decompositions for Muckenhoupt weights in the setting of UMD spaces. As a consequence we obtain two-weight variants of the Mikhlin multiplier theorem for operator-valued multipliers. We also show two-weight estimates for multipliers satisfying Hörmander type conditions.
Quantifying Environmental Impacts of Temporary Housing at the Urban Scale: Intersection of Vulnerability and Post-Hurricane Relief in New Orleans
Authors: McConnell Claire , Bertolin Chiara
Published: December 2019

The increasing risk and exposure of people and assets to natural hazards and disasters suggests an increasing need for temporary housing following disasters. Resilience to natural hazards is dependent on the resources available to families or communities to prepare for and mitigate risk, influenced by social vulnerability. This study seeks to quantify the total environmental impact of temporary housing deployment in New Orleans, using the catastrophic impact of Hurricane Katrina in southern Louisiana in August 2005 as a case example. We employ a novel approach to estimate displacement period and take into account social vulnerability across New Orleans neighborhoods to better understand the scale of post-disaster relief and its global warming potential. The methodology implemented in this study comprises three steps: a risk assessment, a life cycle assessment, and a resulting total impact assessment. We demonstrate the considerable risk of greenhouse gas emissions and energy impacts from temporary housing deployment linked to hurricane hazard. Furthermore, we show that environmental impact is highly sensitive to displacement period and find the current methodology of anticipating temporary housing use by hazard alone to be inadequate. Additionally, the approach presented in this article provides tools to politicians and disaster risk professionals that allow for resource investment planning to decrease social vulnerability, thus enhancing resilience and adaptive capacity in a more homogeneous way at the urban scale.
Sacred Heritage
Authors: Gilchrist Roberta
Published: December 2019

Roberta Gilchrist critically evaluates the concept of sacred heritage. Drawing on global perspectives from heritage studies, archaeology, museology, anthropology and architectural history, she examines the multiple values of medieval Christian heritage. Gilchrist investigates monastic archaeology through the lens of the material study of religion and reveals the sensory experience of religion through case studies including Glastonbury Abbey and Scottish monasticism. Her work offers new insights into medieval identity and regional distinctiveness, healing and magic, and memory practices in the sacred landscape. It also reflects on the significance of medieval sacred landscapes as contested heritage sites which hold diverse meanings to contemporary groups. This title is also available as Open Access.
Happiness and public policy: a procedural perspective
Authors: STUTZER ALOIS
Published: December 2019

This article comments on the role of empirical subjective wellbeing research in public policy within a constitutional, procedural perspective of government and state. It rejects the idea that, based on the promises of the measurement, we should adopt a new policy perspective that is oriented toward a decision rule maximizing some aggregate measure of subjective wellbeing. This social engineering perspective, implicit in much reasoning about wellbeing policy, neglects: (1) important motivation problems on the part of government actors, such as incentives to manipulate indicators, but also on the part of citizens to truthfully report their wellbeing; and (2) procedural utility as a source of wellbeing. Instead, wellbeing research should be oriented toward gaining insights that improve the diagnoses of societal problems and help us to evaluate alternative institutional arrangements in order to address them, both as inputs into the democratic process.
Decision aid for early identification of acute underlying illness in emergency department patients with atrial fibrillation or flutter
Authors: Scheuermeyer Frank X. , Norena Monica , Innes Grant , Grunau Brian , Christenson Jim , Grafstein Eric , Barbic David , Barrett Tyler
Published: December 2019

Background

Emergency department (ED) patients with atrial fibrillation or flutter (AFF) with underlying occult condition such as sepsis or heart failure, and who are managed with rate or rhythm control, have poor prognoses. Such conditions may not be easy to identify early in the ED evaluation when critical treatment decisions are made. We sought to develop a simple decision aid to quickly identify undifferentiated ED AFF patients who are at high risk of acute underlying illness.

Methods

We collected consecutive ED patients with electrocardiogram-proven AFF over a 1-year period and performed a chart review to ascertain demographics, comorbidities, and investigations. The primary outcome was having an acute underlying illness according to prespecified criteria. We used logistic regression to identify factors associated with the primary outcome, and developed criteria to identify those with an underlying illness at presentation.

Results

Of 1,083 consecutive undifferentiated ED AFF patients, 400 (36.9%) had an acute underlying illness; they were older with more comorbidities. Modeling demonstrated that three predictors (ambulance arrival; chief complaint of chest pain, dyspnea, or weakness; CHA2DS2-VASc score greater than 2) identified 93% of patients with acute underlying illness (95% confidence interval [CI], 91–96%) with 54% (95% CI, 50–58%) specificity. The decision aid missed 28 patients; (7.0%) simple blood tests and chest radiography identified all within an hour of presentation.

Conclusions

In ED patients with undifferentiated AFF, this simple predictive model rapidly differentiates patients at risk of acute underlying illness, who will likely merit investigations before AFF-specific therapy.
Effect of probiotic supplementation in pregnant women: a meta-analysis of randomised controlled trials
Authors: Kuang Linghan , Jiang Yongmei
Published: December 2019

Probiotics are being used increasingly in pregnant women, whereas the efficiency on pregnancy outcomes is yet lacking. PubMed, Embase and the Cochrane Library were searched. Relative risks (RR) or weighted mean differences (WMD) with 95 % CI were employed to calculate the summary outcomes. A total of eighteen randomised controlled trials (RCT) including 4356 pregnant women were eligible. The summary RR indicated that probiotic supplementation was associated with a significant decrease in the risk of atopic eczema (RR 0·68; 95 % CI 0·58, 0·81; P < 0·001) and eczema (RR 0·79; 95 % CI 0·68, 0·91; P = 0·002) without significant heterogeneity. Probiotic supplementation was associated with a prolonged gestational age (WMD 0·09; 95 % CI 0·04, 0·15; P = 0·001) with insignificant heterogeneity, whereas no significant effect was exerted on birth weight (P = 0·851). The risks of death (RR 0·34; 95 % CI 0·13, 0·91; P = 0·031) and necrotising enterocolitis (NEC) (RR 0·38; 95 % CI 0·18, 0·81; P = 0·012) were significantly reduced in pregnant women receiving probiotics without evidence of heterogeneity. These findings suggested that probiotics in pregnant women were beneficial for atopic eczema, eczema, gestational age, death and NEC.
Freudenthal's theorem and spherical classes in H*QS0
Authors: Zare Hadi
Published: December 2019

This note is on spherical classes in $H_*(QS^0;k)$ when $k=\mathbb{Z}, \mathbb{Z}/p$, with a special focus on the case of p=2 related to the Curtis conjecture. We apply Freudenthal's theorem to prove a vanishing result for the unstable Hurewicz image of elements in ${\pi _*^s}$ that factor through certain finite spectra. After either p-localization or p-completion, this immediately implies that elements of well-known infinite families in ${_p\pi _*^s}$, such as Mahowaldean families, map trivially under the unstable Hurewicz homomorphism ${_p\pi _*^s}\simeq {_p\pi _*}QS^0\to H_*(QS^0;\mathbb{Z} /p)$. We also observe that the image of the submodule of decomposable elements under the integral unstable Hurewicz homomorphism $\pi _*^s\simeq \pi _*QS^0\to H_*(QS^0;\mathbb{Z} )$ is given by $\mathbb{Z} \{h(\eta ^2),h(\nu ^2),h(\sigma ^2)\}$. We apply the latter to completely determine spherical classes in $H_*(\Omega ^dS^{n+d};\mathbb{Z} /2)$ for certain values of n>0 and d>0; this verifies Eccles' conjecture on spherical classes in $H_*QS^n$, n>0, on finite loop spaces associated with spheres.
ON FINITE-BY-NILPOTENT GROUPS
Authors: DETOMI ELOISA , DONADZE GURAM , MORIGI MARTA , SHUMYATSKY PAVEL
Published: December 2019

Abstarct

Letγn= [x1,…,xn] be thenth lower central word. Denote byXnthe set ofγn-values in a groupGand suppose that there is a numbermsuch that$|{g^{{X_n}}}| \le m$for eachg∈G. We prove thatγn+1(G)has finite (m, n) -bounded order. This generalizes the much-celebrated theorem of B. H. Neumann that says that the commutator subgroup of a BFC-group is finite.
Brain structural effects of treatments for depression and biomarkers of response: a systematic review of neuroimaging studies
Authors: Enneking Verena , Leehr Elisabeth J. , Dannlowski Udo , Redlich Ronny
Published: December 2019

Antidepressive pharmacotherapy (AD), electroconvulsive therapy (ECT) and cognitive behavioural therapy (CBT) are effective treatments for major depressive disorder. With our review, we aim to provide a systematic overview of neuroimaging studies that investigate the effects of AD, ECT and CBT on brain grey matter volume (GMV) and biomarkers associated with response. After a systematic database research on PubMed, we included 50 studies using magnetic resonance imaging and investigating (1) changes in GMV, (2) pre-treatment GMV biomarkers associated with response, or (3) the accuracy of predictions of response to AD, ECT or CBT based on baseline GMV data. The strongest evidence for brain structural changes was found for ECT, showing volume increases within the temporal lobe and subcortical structures – such as the hippocampus–amygdala complex, anterior cingulate cortex (ACC) and striatum. For AD, the evidence is heterogeneous as only 4 of 11 studies reported significant changes in GMV. The results are not sufficient in order to draw conclusions about the structural brain effects of CBT. The findings show consistently that higher pre-treatment ACC volume is associated with response to AD, ECT and CBT. An association of higher pre-treatment hippocampal volume and response has only been reported for AD. Machine learning approaches based on pre-treatment whole brain patterns reach accuracies of 64–90% for predictions of AD or ECT response on the individual patient level. The findings underline the potential of brain biomarkers for the implementation in clinical practice as an additive feature within the process of treatment selection.
Tocqueville on Intellectual Independence, Doubt, and Democratic Citizenship
Authors: Arellano Alec
Published: December 2019

Some contend that politics functions best when deference is given to tradition and authoritative community norms, while others argue for the importance of independent thought and doubt about received sources of authority. Insight into this question can be found in the work of Alexis de Tocqueville. While Tocqueville is often taken to regard the doubt characteristic of intellectual independence solely as a pathology, I show that he also saw it as a potential precursor to conversation, a stimulus to self-assured conviction, and a counter to distortionary abstractions. Nonetheless, Tocqueville also elaborates the destructive outcomes of too much doubt and intellectual independence. I identify the ways in which he seeks to discipline and educate the drive to independent thought so as to attain its benefits without falling victim to its pathologies. In doing so, I demonstrate the ways in which Tocqueville can be a guide to navigating the perennial tension between intellectual inquiry and authoritative community norms.
Educating the global citizen or the global consumer?
Authors: Kramsch Claire
Published: December 2019

In this paper I review three models of language that have dominated language learning and teaching in the last 40 years: the textual model, the information exchange model, and the multilingual model. I analyze each one and consider how it stacks up to instances of language use in a globalized world. I then propose moving beyond the metaphors of citizens and consumers, and consider language teaching as educating denizens of a global ecology that requires sensitivity to context, political awareness, ethical answerability and a good dose of situational cunning.
Teaching and learning L2 in the classroom: It's about time
Authors: Lightbown Patsy M. , Spada Nina
Published: December 2019

One of the challenges facing second and foreign language (L2) teachers and learners in primary and secondary school settings is the limited amount of time available. There is disagreement about how to meet this challenge. In this paper we argue against two ‘common sense’ recommendations for increasing instructional time – start as early as possible and use only the L2 (avoiding the use of the first language (L1)) in the classroom. We propose two better ways to increase the instructional time: provide periods of intensive instruction later in the curriculum and integrate the teaching of language and content. Studies in schools settings around the world have failed to find long-term advantages for an early start or exclusive use of the L2 in the classroom. Nevertheless, many language educators and policy makers continue to adopt these practices, basing their choice on their own intuitions and public opinion rather than on evidence from research.
Unknown External Force Estimation and Collision Detection for a Cooperative Robot
Authors: Yousefizadeh Shirin , Bak Thomas
Published: December 2019

In human–robot cooperative industrial manipulators, safety issues are crucial. To control force safely, contact force information is necessary. Since force/torque sensors are expensive and hard to integrate into the robot design, estimation methods are used to estimate external forces. In this paper, the goal is to estimate external forces acting on the end-effector of the robot. The forces at the task space affect the joint space torques. Therefore, by employing an observer to estimate the torques, the task space forces can be obtained. To accomplish this, loadcells are employed to compute the net torques at the joints. The considered observers are extended Kalman filter (EKF) and nonlinear disturbance observer (NDOB). Utilizing the computed torque obtained based on the loadcells measurements and the observer, the estimates of external torques applied on the robot end-effector can be achieved. Moreover, to improve the degree of safety, an algorithm is proposed to distinguish between intentional contact force from an operator and accidental collisions. The proposed algorithms are demonstrated on a robot, namely WallMoBot, which is designed to help the operator to install heavy glass panels. Simulation results and preliminary experimental results are presented to demonstrate the effectiveness of the proposed methods in estimating the joint space torques generated by the external forces applied to the WallMoBot end-effector and to distinguish between the user-input force and accidental collisions.
Artificial intelligence for team sports: a survey
Authors: Beal Ryan , Norman Timothy J. , Ramchurn Sarvapali D.
Published: December 2019

The sports domain presents a number of significant computational challenges for artificial intelligence (AI) and machine learning (ML). In this paper, we explore the techniques that have been applied to the challenges within team sports thus far. We focus on a number of different areas, namely match outcome prediction, tactical decision making, player investments, fantasy sports, and injury prediction. By assessing the work in these areas, we explore how AI is used to predict match outcomes and to help sports teams improve their strategic and tactical decision making. In particular, we describe the main directions in which research efforts have been focused to date. This highlights not only a number of strengths but also weaknesses of the models and techniques that have been employed. Finally, we discuss the research questions that exist in order to further the use of AI and ML in team sports.
Can inferencing be trained in preschoolers using shared book-reading? A randomised controlled trial of parents’ inference-eliciting questions on oral inferencing ability
Authors: DAVIES Catherine , MCGILLION Michelle , ROWLAND Caroline , MATTHEWS Danielle
Published: December 2019

The ability to make inferences is essential for effective language comprehension. While inferencing training benefits reading comprehension in school-aged children (see Elleman, 2017, for a review), we do not yet know whether it is beneficial to support the development of these skills prior to school entry. In a pre-registered randomised controlled trial, we evaluated the efficacy of a parent-delivered intervention intended to promote four-year-olds’ oral inferencing skills during shared book-reading. One hundred children from socioeconomically diverse backgrounds were randomly assigned to inferencing training or an active control condition of daily maths activities. The training was found to have no effect on inferencing. However, inferencing measures were highly correlated with children's baseline language ability. This suggests that a more effective approach to scaffolding inferencing in the preschool years might be to focus on promoting vocabulary to develop richer and stronger semantic networks.
A cluster of Legionnaires' disease in Belgium linked to a cooling tower, August–September 2016: practical approach and challenges
Authors: Hammami N. , Laisnez V. , Wybo I. , Uvijn D. , Broucke C. , Van Damme A. , Van Zandweghe L. , Bultynck W. , Temmerman W. , Van De Ginste L. , Moens T. , Robesyn E.
Published: December 2019

A cluster of Legionnaires' disease (LD) with 10 confirmed, three probable and four possible cases occurred in August and September 2016 in Dendermonde, Belgium. The incidence in the district was 7 cases/100 000 population, exceeding the maximum annual incidence in the previous 5 years of 1.5/100 000. Epidemiological, environmental and geographical investigations identified a cooling tower (CT) as the most likely source. The case risk around the tower decreased with increasing distance and was highest within 5 km.Legionella pneumophilaserogroup 1, ST48, was identified in a human respiratory sample but could not be matched with the environmental results. Public health authorities imposed measures to control the contamination of the CT and organised follow-up sampling. We identified obstacles encountered during the cluster investigation and formulated recommendations for improved LD cluster management, including faster coordination of teams through the outbreak control team, improved communication about clinical and environmental sample analysis, more detailed documentation of potential exposures obtained through the case questionnaire and earlier use of a geographical information tool to compare potential sources and for hypothesis generation.
Reducing Supervision of Quantitative Image Analysis of Meteorite Samples
Authors: Crapster-Pregont Ellen J. , Ebel Denton S.
Published: December 2019

When selecting a method for determining modal mineralogy and elemental composition of geological samples (e.g., meteorites), a number of factors should be considered, includingthe number of objects or the area to be analyzed; the scale of expected chemical variation; instrument time restrictions; and post-processing time. This study presents a method that minimizes acquisition time while maintaining the ability to distinguish minerals based on combinations of intensities of electron probe micro-analyzer-generated X-ray element maps. While some other methods yield similar outcomes, this method's post-processing utilizes standard parameterized, X-ray intensity “map math” in an algorithm that is adaptable and requires minimal supervision once implemented. This study's minimized supervision in the post-processing of X-ray intensity maps decreases analysis time and its adaptability increases the number of potential applications. The method also facilitates calibration of the exact locations of analysis using laser ablation methods. While the method described here has advantages, the choice of method always depends on the question being asked.
Prospective Validity of the Suicide Cognitions Scale Among Acutely Suicidal Military Personnel Seeking Unscheduled Psychiatric Intervention
Authors: Bryan Craig J. , Rozek David C. , Khazem Lauren R.
Published: December 2019

Abstract. Background and Aim: The Suicide Cognitions Scale (SCS) was developed to assess a broad range of suicide-related cognitions. Research to date supports the scale's factor structure, internal consistency, and construct validity. The present study tested the scale's prospective validity for suicide attempts among 97 military personnel presenting to an emergency department or psychiatric outpatient clinic for an unscheduled walk-in evaluation. Method: Cox regression and receiver operator characteristic analyses were conducted to test the prospective validity of the SCS. Results: Results supported the prospective validity of the SCS (area under the curve [AUC] = 0.69) and indicate the scale's performance is comparable to an empirically supported measure of suicide ideation (AUC = 0.75). The SCS performance was not reduced by removing items containing the word suicide. Limitations: Homogeneous sample comprised of US soldiers, predominantly male, with recent suicidal ideation. Conclusion: Results support the SCS as an indicator of subsequent risk for suicidal behavior when used in acute care settings, and suggest the scale's performance is similar to more traditional suicide risk screening methods that depend on honest self-disclosure of suicidal thoughts.
The Use of Monthly Mean Average for Investigating the Presence of Hysteresis and Long‐Term Trends in Ionospheric NmF2
Authors: Huang Jianping , Hao Yongqiang , Zhang Donghe , Xiao Zuo
Published: December 2019

Yearly averaging is a basic preprocessing of ionospheric data to smooth out the short‐term, cyclic variations in the observations. However, we find that the use of yearly (running) average method probably leads to a biased evaluated relation between the ionospheric parameters (e.g.,
2 peak electron density,
) and the solar extreme ultraviolet (EUV) irradiance. The bias is essentially related to the annual/seasonal variations of the ionosphere, which means that the ionospheric sensitivity to the solar EUV irradiance varies with season and the same solar input can produce different ionization levels in different months/seasons. The yearly method simply averages the observations of different seasons, leading to a biased yearly
‐EUV relation, which will further affect the estimation of the ionospheric hysteresis (different
‐EUV relation in the solar rising and declining phase). Also, the extraction of long‐term trends in the ionosphere will be more uncertain if using a regression approach based on the biased
‐EUV relation. In conclusion, we suggest to do the analysis month by month (using monthly average method) to properly deal with the annual/seasonal variations of the ionosphere, and to obtain accurate estimation of the hysteresis and long‐term trends. Though both the yearly and monthly methods were used in precedent works, the bias introduced by the yearly average method has not been fully recognized prior to this study.
Comprehensive Analysis of the Magnetic Signatures of Small‐Scale Traveling Ionospheric Disturbances,as Observed by Swarm
Authors: Yin Fan , Lühr Hermann , Park Jaeheung , Wang Ling
Published: December 2019

Based on Swarm satellite data from 2015 through 2018, we present the mean characteristics of magnetic field fluctuations at midlatitudes and low latitudes. It is the first comprehensive study focusing on small‐scale variations (<10 km). Events are observed on about 35% of the orbits. The highest occurrence rates are detected after sunset, in the East Asian/Australian sector, and during months around June solstice. Low occurrence rates are found at low magnetic latitudes (below ±10° quasi‐dipole latitude), in the region of the South Atlantic Anomaly, and during equinox seasons. All these occurrence features compare well with those of medium‐scale traveling ionospheric disturbances. We therefore term our small‐scale events small‐scale traveling ionospheric disturbances (SSTIDs). SSTIDs exhibit high field‐aligned current (FAC) densities connected to narrow current sheets with meridional width of typically 4 km. The intense FACs of several μA/m2 flow typically between the hemispheres. Return currents are distributed over larger scales and thus have smaller amplitudes. Peak current densities get larger toward lower latitudes. There are two groups of events, around morning‐noontime and evening‐night, which are separated by demarcation lines near 04 and 15 magnetic local time. The magnetic amplitudes of the small‐scale fluctuations are larger in sunlight than in darkness, indicating larger total currents in the loops. But the FAC peak current densities are larger in darkness, inferring a stronger squeezing of the current sheet under low‐conductivity conditions. We suggest that our SSTIDs are an evolutional state of medium‐scale traveling ionospheric disturbances.
Periodic Mesoscale Eddies in the South China Sea
Authors: Chu Xiaoqing , Chen Gengxin , Qi Yiquan
Published: December 2019

Although numerous mesoscale eddies are observed in the South China Sea (SCS), a comprehensive study that focuses on periodic eddies has not yet been reported. Periodic eddies are a type of eddies that occur nearly annually in fixed time frames with similar patterns and trajectories. On the basis of in situ and satellite observations, this paper reports a periodic anticyclonic eddy in the western SCS (the Western SCS Anticyclonic Eddy, WAE) and elucidates the underlying processes responsible for its generation and evolution. The WAE is a seasonal phenomenon modulated by the Asian monsoon and basin‐scale circulation. Usually, the WAE generates around 112°E, 14°N in February–March, induced by the cyclonic gyre in the northern SCS associated with the winter monsoon. The WAE occupies the western SCS for 5 months and finally dissipates in July due to the reversal of the monsoon and thus the circulation transition. The WAE shows important interannual variations associated with large‐scale climate variation, and the Niño‐3.4 index could be a potential predictor for its interannual variation. Finally, we summarize 13 periodic eddies in the SCS, including those unreported by previous studies. The period eddies in the SCS exhibit an inverse “L” shape vortex train structure along the western boundary and around the 17°N section, with an anticyclonic “phase” in summer and a cyclonic “phase” in winter. This study provides new knowledge for periodic eddies in the SCS and will benefit targeted observations of periodic eddies.
Evaporation From the Southern Ocean Estimated on the Basis of AIRS Satellite Data
Authors: Boisvert Linette , Vihma Timo , Shie Chung‐Lin
Published: December 2019

Evaporation plays an important role in the global water and energy cycles and, hence, in climate change. Evaporation over the Southern Ocean, where the Antarctic sea ice coverage has a large annual cycle, is poorly quantified. In this study, daily evaporation is estimated for the Southern Ocean with a sea‐ice‐specific algorithm, using surface temperature and air humidity from National Aeronautics and Space Administration's Atmospheric Infrared Sounder (AIRS), and wind speeds from Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2), reanalysis during 2003–2016. An uncertainty of 34% was found in the evaporation product. The results indicate that annual evaporation has considerable interannual and regional variability, but with a decreasing trend during the study period over most of the Southern Ocean. There are, however, areas where evaporation has increased, specifically in the Ross Sea in winter and summer, with smaller positive trends in spring and fall. Overall, the changes in the difference between the surface specific humidity and the air specific humidity, and to a much lesser extent in the wind speed, are the main drivers for the changes in evaporation throughout the year. During spring and fall months, changes to the sea ice cover, which alter the surface specific humidity, are the main drivers for the change, but in summer and winter the main driver is the air‐specific humidity. Air masses originating from the Antarctic continent (south) are associated with cold and dry conditions, which increase evaporation, whereas air masses from lower latitudes in the Southern Ocean (north) are associated with warm and moist conditions, decreasing evaporation. Comparisons with other reanalysis evaporation products produce similar trends, although annual averages differ.
An Integrated Agriculture, Atmosphere, and Hydrology Modeling System for Ecosystem Assessments
Authors: Ran L. , Yuan Y. , Cooter E. , Benson V. , Yang D. , Pleim J. , Wang R. , Williams J.
Published: December 2019

We present a regional‐scale integrated modeling system (IMS) that includes Environmental Policy Integrated Climate (EPIC), Weather Research and Forecast (WRF), Community Multiscale Air Quality (CMAQ), and Soil and Water Assessment Tool (SWAT) models. The centerpiece of the IMS is the Fertilizer Emission Scenario Tool for CMAQ (FEST‐C), which includes a Java‐based interface and EPIC adapted to regional applications along with built‐in database and tools. The SWAT integration capability is a key enhanced feature in the current release of FEST‐C v1.4. For integrated modeling demonstration and evaluation, FEST‐C EPIC is simulated over three individual years with WRF/CMAQ weather and N deposition. Simulated yearly changes in water and N budgets along with yields for two major crops (corn grain and soybean) match those inferred from intuitive physical reasoning and survey data given different‐year weather conditions. Yearlong air quality simulations with an improved bidirectional ammonia flux modeling approach directly using EPIC‐simulated soil properties including NH3 content helps reduce biases of simulated gas‐phase NH3 and NH4+ wet deposition over the growing season. Integrated hydrology and water quality simulations applied to the Mississippi River Basin show that estimated monthly streamflow and dissolved N near the outlet to the Gulf of Mexico display similar seasonal patterns as observed. Limitations and issues in different parts of the integrated multimedia simulations are identified and discussed to target areas for future improvements.
Parameterizing Perennial Bioenergy Crops in Version 5 of the Community Land Model Based on Site‐Level Observations in the Central Midwestern United States
Authors: Cheng Yanyan , Huang Maoyi , Chen Min , Guan Kaiyu , Bernacchi Carl , Peng Bin , Tan Zeli
Published: December 2019

With projected expansion of biofuel production at a global scale, there is a pressing need to develop adequate representation of bioenergy crops in land surface models to help effectively quantify the biogeophysical and biogeochemical effects of its associated land use changes. This study implements two new perennial bioenergy crops, Miscanthus and switchgrass, into the Community Land Model Version 5 based on site‐level observations from the midwestern United States by modifying parameters associated with photosynthesis, phenology, allocation, decomposition, and carbon cost of nitrogen uptake and integrating concomitantly land management practices. Sensitivity analyses indicate that carbon and energy fluxes of the perennial crops are most sensitive to photosynthesis and phenology parameters. Validation of simulated fluxes against site‐level measurements demonstrates that the model is capable of capturing the overall patterns of energy and carbon fluxes, as well as physiological transitions from leaf emergence to senescence. Compared to annual crops, perennial crops feature longer growing season, greater leaf areas, and higher productivity, leading to increased transpiration, lower annual runoff, and larger carbon uptake. The model simulations suggest that with higher CO2 assimilation rates and lower demands for nutrients and water, high‐yielding perennial crops are promising alternatives of bioenergy feedstocks compared to traditional annual crops not only for mitigating climate change but also for environmental conservation purposes by reducing fertilizer application and therefore alleviating surface‐ and ground‐water contaminations. Although the local‐scale simulations shed light on potential benefits of using perennial grasses as bioenergy feedstocks, quantifying consequences of their plantations at larger scales warrants additional investigation.
Mathematical Reconstruction of Land Carbon Models From Their Numerical Output: Computing Soil Radiocarbon From C Dynamics
Authors: Metzler Holger , Zhu Qing , Riley William , Hoyt Alison , Müller Markus , Sierra Carlos A.
Published: December 2019

Radiocarbon (14C) is a powerful tracer of the global carbon cycle that is commonly used to assess carbon cycling rates in various Earth system reservoirs and as a benchmark to assess model performance. Therefore, it has been recommended that Earth System Models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 report predicted radiocarbon values for relevant carbon pools. However, a detailed representation of radiocarbon dynamics may be an impractical burden on model developers. Here, we present an alternative approach to compute radiocarbon values from the numerical output of an ESM that does not explicitly represent these dynamics. The approach requires computed 12C stocks and fluxes among all carbon pools for a particular simulation of the model. From this output, a time‐dependent linear compartmental system is computed with its respective state‐transition matrix. Using transient atmospheric 14C values as inputs, the state‐transition matrix is then applied to compute radiocarbon values for each pool, the average value for the entire system, and component fluxes. We demonstrate the approach with ELMv1‐ECA, the land component of an ESM model that explicitly represents 12C, and 14C in 7 soil pools and 10 vertical layers. Results from our proposed method are highly accurate (relative error <0.01%) compared with the ELMv1‐ECA 12C and 14C predictions, demonstrating the potential to use this approach in CMIP6 and other model simulations that do not explicitly represent 14C.
Upscaling Reactive Transport Under Hydrodynamic Slip Conditions in Homogeneous Porous Media
Authors: Valdés‐Parada Francisco J. , Lasseux Didier , Whitaker Stephen
Published: December 2019

Reactive transport of a dilute species in a Newtonian fluid saturating a homogeneous porous medium for slip flow is analyzed in this work. Incompressible Newtonian flow with a first‐order (Navier) slip boundary condition is considered together with a first‐order heterogeneous reaction. Kinetic numbers range up to unity while Knudsen numbers, characteristic of slip‐flow, are smaller than approximately 0.1. The pore‐scale problem is upscaled, using the volume averaging method, to obtain a macroscopic transport equation (referred to as the complete upscaled model) operating at the Darcy scale. Using order of magnitude estimates and an expansion in terms of the Kinetic number, simplifications in the expressions of the effective coefficients are explored. The conditions under which the effective convective velocity and the total dispersion tensor are independent of reaction are derived. Under such conditions, a simplified version of the macroscopic transport equation is obtained. This is referred to as the simplified model. Numerical results for a simple structure indicate that the longitudinal dispersion coefficient decreases with decreasing Knudsen number, while the opposite holds for the transverse component of the total dispersion tensor, the effective convective velocity, and the effective reaction rate coefficient. These effects are more evident when the Péclet number increases (i.e., in the convective‐favored regime) and when slip effects are more pronounced. Results predicted by the simplified and the complete versions of the upscaled model are validated with direct numerical simulations of the pore‐scale problem on a two‐dimensional model structure.
DKC1 enhances angiogenesis by promoting HIF-1α transcription and facilitates metastasis in colorectal cancer
Authors: Hou Pingfu , Shi Peicong , Jiang Tao , Yin Hang , Chu Sufang , Shi Meilin , Bai Jin , Song Jun
Published: December 2019

Background

Dyskeratosis congenita 1 (DKC1) is dysregulated in several cancers. However, the expression and function of DKC1 in colorectal cancer (CRC) is rarely reported.

Methods

Tissue microarrays (TAMs) including 411 cases of CRC tissues and corresponding paracancerous tissues were used to examine the DKC1 expression. The correlations between the DKC1 expression and clinicopathological or survival characters were further analysed. The functions and molecular mechanism of DKC1 in CRC were investigated through a series of in vitro and in vivo experiments.

Results

The result showed that DKC1 expression was increased in CRC tissues. Increased DKC1 expression was associated with high grade of TNM stage, additional lymph node metastasis, and poor prognosis of patients with CRC. Multivariate COX analysis indicated that DKC1 can act as an independent prognostic factor for patients with CRC. DKC1 also facilitated the CRC angiogenesis and metastasis by increasing HIF-1α and VEGF expression levels. Chromatin immunoprecipitation assay demonstrated that DKC1 facilitated HIF-1α expression by regulating HIF-1α promoter activity.

Conclusion

DKC1 appears to regulate CRC angiogenesis and metastasis through directly activating HIF-1α transcription. DKC1 can serve as an accurate indicator in predicting the prognosis of patients with CRC and act as a potential therapeutic target for CRC.
Paclitaxel induces lymphatic endothelial cells autophagy to promote metastasis
Authors: Zamora Audrey , Alves Melinda , Chollet Charlotte , Therville Nicole , Fougeray Tiffany , Tatin Florence , Franchet Camille , Gomez-Brouchet Anne , Vaysse Charlotte , Martinez Laurent O. , Najib Souad , Guillermet-Guibert Julie , Lacazette Eric , Prats Anne-Catherine , Garmy-Susini Barbara
Published: December 2019

Cytotoxic therapy for breast cancer inhibits the growth of primary tumors, but promotes metastasis to the sentinel lymph nodes through the lymphatic system. However, the effect of first-line chemotherapy on the lymphatic endothelium has been poorly investigated. In this study, we determined that paclitaxel, the anti-cancer drug approved for the treatment of metastatic or locally advanced breast cancer, induces lymphatic endothelial cell (LEC) autophagy to increase metastases. While paclitaxel treatment was largely efficacious in inhibiting LEC adhesion, it had no effect on cell survival. Paclitaxel inhibited LEC migration and branch point formation by inducing an autophagy mechanism independent of Akt phosphorylation. In vivo, paclitaxel mediated a higher permeability of lymphatic endothelium to tumor cells and this effect was reversed by chloroquine, an autophagy-lysosome inhibitor. Despite a strong effect on reducing tumor size, paclitaxel significantly increased metastasis to the sentinel lymph nodes. This effect was restricted to a lymphatic dissemination, as chemotherapy did not affect the blood endothelium. Taken together, our findings suggest that the lymphatic system resists to chemotherapy through an autophagy mechanism to promote malignant progression and metastatic lesions. This study paves the way for new combinative therapies aimed at reducing the number of metastases.