bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Approach to Classify Nailfold Capillary Images in Indian Population Using USB Digital Microscope
Authors: Suma K. V.  , Sasi Vishwajit , Rao Bheemsain
Published: February 2018

Nailfold capillaroscopy is a simple, non-invasive clinical aid used for the diagnosis of vascular dysfunction. The method proposed emphasizes on the USB Digital Microscope which is a cheaper and useful alternative to commercially available expensive videocapillaroscopes which produces high quality images. As the process of identifying anomalies in nailfold capillaries is a tedious and time-consuming process this article proposes a completely automated system to diagnose anomalies. The nailfold capillary images are pre-processed to highlight the important features and remove noise in the images. The processed images are then used to train machine learning models. This article then assays and compares the performance of Logistic Regression classifier, fully connected neural network, Convolutional Neural Network (CNN) and Random Forest classifiers by evaluating their classification accuracy, sensitivity and specificity. The results prove Logistic Regression to be most accurate with a low classification error rate of 10.64%. while, a substantial classification accuracy of 72% was obtained with a small dataset by using bottleneck features of a deep CNN.
Uncertain Hamacher Aggregation Operators and Their Application to Multiple Attribute Decision Making
Authors: Wei Guiwu
Published: February 2018

This article utilizes Hamacher operations to develop some uncertain aggregation operators: uncertain Hamacher weighted average (UHWA) operator, uncertain Hamacher weighted geometric (UHWG) operator, uncertain Hamacher ordered weighted average (UHOWA) operator, uncertain Hamacher ordered weighted geometric (UHOWG) operator, uncertain Hamacher hybrid average (UHHA) operator, uncertain Hamacher hybrid geometric (UHHG) operator and some uncertain Hamacher correlate aggregation operators and uncertain induced Hamacher aggregation operators. The prominent characteristics of these proposed operators are studied. Then, the article utilizes these operators to develop some approaches to solve the uncertain multiple attribute decision making problems. Finally, a practical example is given to verify the developed approach and to demonstrate its practicality and effectiveness.
Climate Change Information and Media
Authors: Neelima B. N.
Published: February 2018

Climate change is a scientific, health, political, economic, national security, environmental, moral and religious issue, among many others. The article presents the findings of a study which investigates what messages and messengers best engage young people with climate science and its solutions. The opinions and media habits of young adults, aged 18-25 currently residing and studying in two metropolises of India, Bengaluru (Bangalore) and Chennai (Madras) vis-à-vis climate change have been elicited and interpreted. A survey of 500 randomly selected college and university students studying and residing in these two metropolises have revealed a heightened concern for the global environment and climate change issues among youth. The extent of information the respondents had on climate change issues was considerable. The respondents relied more on social media, especially blogs and networking groups for information on climate change, than the traditional mass media. Gender, economic status, course of study, and parental education were some of the important variables strongly associated with knowledge about climate change issues.
“Sasi”
Authors: Kaya Ivonne Raystika Gretha , Hutabarat Johannes , Bambang Azis Nur
Published: February 2018

This article describes how seaweed farming is one of the primary livelihoods in the West Ceram Regency. This activity has been done by the local people and others since 2006. However, the competition over land use between the cultivators of the seaweed, groupers, and fishermen have caused declining seaweed production. Semi-structured interviews, in-depth interviews and participant observations were conducted with seaweed farmers, fishermen catch, grouper farmers, and the government (Marine and Fisheries Department) (n = 83) in three villages. An in-depth interview with seaweed farmers was performed to deepen the understanding of the working conditions and related problems. One way to resolve the seaweed farmers problem in Kotania Bay is by applying Molucass local wisdom, named sasi. Sasi is applied at the time of planting seaweed and called “Tutup Sasi” and called “Buka Sasi” at harvesting with Kewang control. Finally, the article concludes that the use of “sasi” can manage the competition and resolve conflict, ensure continued business, increase efficiency and provide equity resource management.
Information Technology Resources, the Organizational Capability of Lean-Agile Manufacturing, and Business Performance
Authors: Ghobakhloo Morteza , Azar Adel
Published: February 2018

This article drew on the resource-based view of the firm and assessed how manufacturing firms—particularly in developing countries—can leverage their IT resources in support of lean manufacturing and agile manufacturing. The data collection was conducted via a survey of Iranian automobile manufacturers that supply international automobile makers. The result showed that IT resources are crucial to the development of lean manufacturing and agile manufacturing. The value of IT is truly transformed to performance improvement when IT resources are effectively leveraged in support of these manufacturing systems. Lean and agile manufacturing are two manufacturing strategies that can co-exist in one system and agile manufacturing may flourish under lean manufacturing circumstances. Complementarities exist among different practices of lean manufacturing as well as different dimensions of agile manufacturing. The authors' findings offer theoretical insights regarding the values of IT-enabled lean manufacturing and agile manufacturing at operation and strategic levels.
Development and Evaluation of Equipment Enhancements for Transient Liquid Phase Bonding (TLPB) and Sintering
Authors: Rangelov Ventzeslav , Altenbockum Silvia , Kleff Jessica , Weber Constanze , Oppermann Hermann , Lang Klaus-Dieter
Published: February 2018

Operating devices at higher temperatures in automotive applications and the use of wide bandgap materials have driven the development of new bonding technologies as silver sintering and transient liquid phase bonding (TLPB). Considering their specific demands a dedicated tool for processing in batch was developed and characterized. Press unit containing a flexible elastomer membrane was implemented in a vacuum reflow soldering chamber. It allows bonding of various devices with different thickness without using height compensating tooling. Pressures up to 0.5 MPa, temperatures of maximum 300 °C and reducing atmosphere were utilized to demonstrate the process capability for void free low pressure silver sintering and Cu-Sn TLPB.
Amazighopsidae, a new family of decapod macruran astacideans from the late Cretaceous (Cenomanian-Turonian) of Gara Sbaa, Southeastern Morocco
Authors: Garassino Alessandro , Pasini Giovanni
Published: February 2018

We investigate a new decapod macruran discovered in deposits identified at the top of Gara Sbaa slope, located in SE Morocco, along the “Hamada des Kem Kem”, close to the Algerian border. These fossiliferous levels are known in the literature as part of the Late Cretaceous Kem Kem beds. We report the new family Amazighopsidae, created to accommodate Amazighopsis cretacica n. gen., n. sp. Indeed, some morphological characters, such as a short rostrum with the serrate upper margin, cervical and antennal grooves not forming the characteristic W-shaped pattern, the telson without diaeresis, lateral margins of the telson with one movable median spine and two movable distal spines, and the uropodal exopod without diaeresis, are so peculiar and unique to justify the erection of the new family tentatively ascribed to the infraorder Astacidea.
A "milder" version of Calderón's inverse problem for anisotropic conductivities and partial data
Authors: Ouhabaz El Maati
Published: February 2018

Given a general symmetric elliptic operator

L_{a} := \sum_{k,j=1}^d \partial_k (a_{kj} \partial_j ) + \sum_{k=1}^d a_k \partial_k - \partial_k(\overline{a}_k . ) + a_0

we define the associated Dirichlet–to–Neumann (D-t-N) map with partial data, i.e., data supported in a part of the boundary. We prove positivity,

L^p

-estimates and domination properties for the semigroup associated with this D-t-N operator. Given

L_a

and

L_b

of the previous type with bounded measurable coefficients

a = \{a_{kj}, a_k, a_0 \}

and

b = \{b_{kj}, b_k, b_0 \}

, we prove that if their partial D-t-N operators (with

a_0

and

b_0

replaced by

a_0 -\lambda

and

b_0 -\lambda

) coincide for all

\lambda

, then the operators

L_a

and

L_b

, endowed with Dirichlet, mixed or Robin boundary conditions are unitary equivalent. In the case of the Dirichlet boundary conditions, this result was proved recently by Behrndt and Rohleder [6] for Lipschitz continuous coefficients. We provide a different proof, based on spectral theory, which works for bounded measurable coefficients and other boundary conditions.
Madžarska v luči obiska turistov iz Slovenije – prostorska razporeditev turističnega prometa in spletne ponudbe
Authors: Koderman Miha , Kerma Simon , Kostanjšek Tomaž
Published: February 2018

V prispevku so predstavljene poglavitne značilnosti potovanj turistov iz Slovenije na Madžarsko. Uvodoma je podan pregled ključnih turističnih kazalcev te države, ki se v nadaljevanju podrobneje osredotoči na turiste iz Slovenije in njihovo vlogo v strukturi tujih obiskovalcev. Drugi del prispevka povzema glavne izsledke analize spletne ponudbe organiziranih turističnih potovanj, ki jo oglašujejo slovenske turistične agencije. Ponudba je bila predmet prostorske in vsebinske (pogostost pojavljanja oglaševanih destinacij, vrsta storitev, trajanje in cena) analize.
A contrastive morphological analysis of tense formation in Igbo and Yoruba: implication on learners and teachers
Authors: Uwaezuoke Aghaegbuna Haroldson , Ogunkeye Olufunmilayo M.
Published: February 2018

This paper is a contrastive morphological study of tenses in the Igbo and Yoruba languages. It is limited to tenses only excluding aspects. It intends to aid speakers of the two languages in their effort to learn another’s language. This is considered vital since the two languages are among the major languages in Nigeria and people have become interested in learning them. Globalization has also necessitated the transfer of technological information into these languages, thus making this paper an invaluable one. Data for the two languages are collected from the primary and secondary sources in addition to the researchers’ intuitive knowledge of the languages. Data are analyzed using a contrastive analysis approach. Our findings show that there are differences in the processes of forming tenses in both languages. For instance, Igbo has indicative suffix –rV which may be deleted or optionally used with certain verbs in the present, and obligatorily used for verbs in the past, but in Yoruba, the present tense and past tense are unmarked. A hyphen is written between the future morpheme and the verb in Igbo, but Yoruba has a separate free morpheme to express the future. Also, in Igbo the 1st person singular pronoun and the 3rd person plural pronoun can come after the future morpheme –ga which is prefixed with a followed by the prefixed verbroot, but in Yoruba all the subject pronouns come before the future morpheme. These areas of differences are predicted by contrastive analysis as constituting learning difficulties. This paper  proffers solution to the perceived tense problem by advocating that teachers should be more attentive to their students’ speeches and write-ups in order to immediately correct any error that might occur. They should avail themselves of the available materials on contrastive analysis such as this and guide the students to know the formation of tenses in these languages and immediately correct any error that might occur or better prevent the errors from manifesting.
Gestión del ruido ambiental en Valencia
Authors: Bejarano Juan Sebastián , Diago Sara
Published: February 2018

El presente documento trata de realizar un análisis exhaustivo, en base a los datos ofrecidos por el Ayuntamiento de Valencia, sobre el nivel de afectación del ruido en la sociedad valenciana. Para nuestro estudio tomaremos como base los 19 distritos de que consta la ciudad de Valencia y emplearemos los datos relativos a las 6 estaciones de ruido que tiene nuestra ciudad, cruzando éstos con otros indicadores de interés para efectuar las conclusiones de nuestro proyecto.
High-molecular-weight esters in α-pinene ozonolysis secondary organic aerosol: Structural characterization and mechanistic proposal for their formation from highly oxygenated molecules
Authors: Kahnt Ariane , Vermeylen Reinhilde , Iinuma Yoshiteru , Safi Shalamzari Mohammad , Maenhaut Willy , Claeys Magda
Published: February 2018

Abstract. Stable high-molecular-weight esters are present in α-pinene ozonolysis secondary organic aerosol (SOA) with the two most abundant ones corresponding to a diaterpenylic ester of cis-pinic acid with a molecular weight (MW) of 368 C19H28O7) and a hydroxypinonyl ester of cis-pinic acid with a MW of 358 (C17H26O8). However, their molecular structures are not completely elucidated and their relationship with highly oxygenated molecules (HOMs) in the gas phase is still unclear. In this study, liquid chromatography in combination with positive ion electrospray ionization mass spectrometry has been performed on high-molecular-weight esters present in α-pinene/O3 SOA with and without derivatization into methyl esters. Unambiguous evidence could be obtained for the molecular structure of the MW 368 ester in that it corresponds to an ester of cis-pinic acid where the carboxyl substituent of the dimethylcyclobutane ring and not the methylcarboxyl substituent is esterified with 7-hydroxypinonic acid. The same linkage was already proposed in previous work for the MW 358 ester (Yasmeen et al., 2010), but could be supported in the present study. Guided by the molecular structures of these stable esters, we propose a formation mechanism from gas-phase HOMs that takes into account the formation of an unstable C19H28O11 product, which is detected as a major species in α-pinene ozonolysis experiments as well as in the pristine forest atmosphere by chemical ionization – atmospheric pressure ionization – time-of-flight mass spectrometry with nitrate clustering (Ehn et al., 2012, 2014). It is suggested that an acyl peroxy radical related to cis-pinic acid (RO2·) and an alkoxy radical related to 7- or 5-hydroxypinonic acid (R'O·) serve as key gas-phase radicals and combine according to a RO2· + R'O· → RO3R' radical termination reaction. Subsequently, the unstable C19H28O11
Chemical modeling of the reactivity of short-lived greenhouse gases: a model inter-comparison prescribing a well-measured, remote troposphere
Authors: Prather Michael J. , Flynn Clare M. , Zhu Xin , Steenrod Stephen D. , Strode Sarah A. , Fiore Arlene M. , Correa Gustavo , Murray Lee T. , Lamarque Jean-Francois
Published: February 2018

Abstract. We develop a new protocol for merging in situ measurements with 3-D model simulations of atmospheric chemistry with the goal of integrating over the data to identify the most reactive air parcels in terms of tropospheric production and loss of the greenhouse gases ozone and methane. Presupposing that we can accurately measure atmospheric composition, we examine whether models constrained by such measurements agree on the chemical budgets for ozone and methane. In applying our technique to a synthetic data stream of 14,880 parcels along 180 W, we are able to isolate the performance of the photochemical modules operating within their global chemistry-climate and chemistry-transport models, removing the effects of modules controlling tracer transport, emissions, and scavenging. Differences in reactivity across models are driven only by the chemical mechanism and the diurnal cycle of photolysis rates, which are driven in turn by temperature, water vapor, solar zenith angle, clouds, and possibly aerosols and overhead ozone, which are calculated in each model. We evaluate six global models and identify their differences and similarities in simulating the chemistry through a range of innovative diagnostics. All models agree that the more highly reactive parcels dominate the chemistry (e.g., the hottest 10 % of parcels control 25–30 % of the total reactivities), but do not fully agree on which parcels comprise the top 10 %. Distinct differences in specific features occur, including the regions of maximum ozone production and methane loss, as well as in the relationship between photolysis and these reactivities. Unique, possibly aberrant, features are identified for each model, providing a benchmark for photochemical module development. Among the 6 models tested here, 3 are almost indistinguishable based on the inherent variability caused by clouds, and thus we identify 4, effectively distinct, chemical models. Based on this work, we suggest that water vapor differences in model simulations of past and future atmospheres may be a cause of the different evolution of tropospheric O3 and CH4, and lead to different chemistry-climate feedbacks across the models.
Groundwater–surface water relations in regulated lowland catchments; hydrological and hydrochemical effects of a major change in surface water level management
Authors: Rozemeijer Joachim , Klein Janneke , Hendriks Dimmie , Borren Wiebe , Ouboter Maarten , Rip Winnie
Published: February 2018

Abstract. In lowland deltas with intensive land use such as The Netherlands, surface water levels are tightly controlled by inlet of diverted river water during dry periods and discharge via large-scale pumping stations during wet periods. The conventional water level regime in these polder catchments is either a fixed water level year-round or an unnatural regime with a lower winter level and a higher summer level in order to optimize hydrological conditions for agricultural land use. The objective of this study was to assess the hydrological and hydrochemical effects of changing the water level management from a conventional fixed water level regime to a flexible, more natural regime with low levels in summer and high levels in winter between predefined minimum and maximum levels. Ten study catchments were hydrologically isolated and equipped with controlled inlet and outlet weirs or pumping stations. The water level management was converted into a flexible regime. We used water and solute balance modeling for catchment-scale assessments of changes in water and solute fluxes. Our model results show relevant changes in the water exchange fluxes between the polder catchment and the regional water system and between the groundwater, surface water, and field surface storage domains within the catchment. Compared to the reference water level regime, the flexible water level regime water balance scenario showed increased surface water residence times, reduced inlet and outlet fluxes, reduced groundwater-surface water exchange, and in some catchments increased overland flow. The solute balance results show a general reduction of chloride concentrations and a general increase in N-tot concentrations. The total phosphorus (P-tot) and sulfate (SO4) concentration responses varied and depended on catchment-specific characteristics. For our study catchments, our analyses provided a quantification of the water flux changes after converting towards flexible water level management. Regarding the water quality effects, this study identified the risks of increased overland flow in former agricultural fields with nutrient enriched top soils and of increased seepage of deep groundwater which can deliver extra nutrients to surface water. At a global scale, catchments in low-lying and subsiding deltas are increasingly being managed in a similar way as the Dutch polders. Applying our water and solute balance approach to these areas may prevent unexpected consequences of the implemented water level regimes.
Exploring the Typology of Challenges and Strategies in Translating Culture-Bound Items for Professional Purposes
Authors: Aldhahi Maha M. , Fernández-Parra María , Davies Lloyd H.
Published: February 2018

The translation of culture-bound expressions such as idioms, proverbs and similes can be a challenge even for professional translators who are expected to have an excellent command of the languages they work with, at least theoretically. Challenges arise when either the image or the meaning of the source language expression does not exist in the target language. For instance, the Arabic simile كمسمار جحا translates literally as “like Juha’s nail” (image). However, a more suitable translation into English would in fact be along the lines of “no more than a vacuous excuse” (meaning). Therefore, in this paper, the author aims to establish, by conducting a survey of Arab professionals, the extent to which these expressions pose a challenge when translating between English and Arabic. In this survey, translators are also asked to translate selected culture-bound expressions and comment on them. The initial results will show that the translation of culture-bound expressions can indeed cause significant challenges for professional translators and that these challenges can be grouped into five categories on the basis of image and meaning. Suggestions regarding procedures will be made to overcome these cultural challenges by category. Overall, the results will suggest that there is a pressing need to increase the cultural component in translator training programmes.
Dr. Strangelove or How I Should Stop Worrying and Love Fascism
Authors: Dias Andre
Published: February 2018

This paper presents a Foucauldian discourse analysis of Stanley Kubrick’s Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb. The analysis examines linguistic and extralinguistic aspects of both the film and the novel. It is composed of three parts: the first is an analysis of the Manichaeism during the Cold War period and how it turned the Soviets into mortal enemies of the United States; the second is how the nuclear threat and the Cold War paranoia could destroy the democratic system in the United States; and the third analysis explain how Fascistic relations could be cultivated through the discipline of bodies. It has been concluded that the movie is presenting a concept, here referred to as Strangelove’s Hypothesis, that a Strangelovian scenario (i.e., a nuclear holocaust, usually caused by incompetence or without the will to do so) could lead to the emergence of a Fascistic-like form of government in order to restore security. The solution presented to avoid such scenario is a sociopsychological change in order to pursue more peaceful relations.
Comparative Examination of the Primary School Science Curricula in Turkey (Curricula of 1992, 2001, 2005, 2013 and 2017)
Authors: Hamurcu Hülya
Published: February 2018

In the present study, the science course curricula of 1992, 2001, 2005, 2013 and 2017 taught at the primary school level in Turkey have been examined comparatively in terms of four main elements (Target, Content, Educational Status, and Measurement and Evaluation). The reason for investigating the science curriculum at five key years was to identify and examine main changes in the system. To this end, the main elements of the curricula were presented in a table. The similarities and differences between the curricula in question were determined and interpreted as a result of the evaluations. The study was carried out using the document review technique, among qualitative research methods. The science curricula published by the Ministry of National Education were analysed in the study. The curricula of the afore-mentioned years were first analysed separately in the process, and then the results were re-investigated by being gathered together. Therefore, it was attempted to ensure the consistency of the data. The results achieved show that the curricula cannot be realized as expected due to certain problems encountered in the process of implementation despite overall positive developments (the fact that teachers are not informed sufficiently, infrastructure problems, crowded classes, the lack of technological equipment, etc.)
Contradictions as Drivers for Improving Inclusion in Teaching Pupils with Special Educational Needs
Authors: Paju Birgit , Kajamaa Anu , Pirttimaa Raija , Kontu Elina
Published: February 2018

The aim of this paper is to enhance understanding of the contradictions that arise in the drive to improve teaching practices among pupils with special educational needs (SENs). A questionnaire was administrated to 167 classroom teachers, subject teachers, special education teachers and teaching assistants in Finland. The analysis, based on thematic coding and analysis of manifestations of contradictions, revealed contradictions related to artefacts of teaching, participation in the community and school staff’s professional ability to teach SEN pupils in mainstream. Four types of manifestations, namely conflicts, critical conflicts, dilemmas, and double binds, could be identified in the data. Focusing the improvement of inclusive practices on all pupils calls for the collective resolution of contradictions and the development of tools and models that facilitate the educational change.
Identity and othering in past and present: Representations of the Soviet era in Estonian post-Soviet textbooks
Authors: Kello Katrin
Published: February 2018

This paper analyses representations of the ‘core Soviet era’ (1945-1985) in Estonian post-Soviet history textbooks (1989-2016). Attitudes towards the Soviet system have been a rich resource for identity building, and hence a powerful political tool across the whole of the post-Soviet block. Based on an analysis of sections about the Soviet era in Estonia in 21 textbooks, the paper takes a look at how textbooks reflect broader processes of social meaning making, identity building and othering after a profound social and political turn. In 1989 and during the early 1990s, perspectives and narratives in Estonian history textbooks were closely related to social memory and national politics, enacting a specific social representation of the Soviet era that dominated the Estonian-speaking public space during the 1990s. The Soviet era, Russia and local Russians became the main Others for Estonia and Estonians. Over time, public discourse has diversified. The national curriculum and textbooks, however, still maintain the canon that formed in 1990s and thus reflect earlier sentiments. Apart from the increasing salience of Soviet-era daily life in more recent textbooks, the thematic choices and emphases have changed little since the 1990s. Therefore, even if the style of writing has ‘cooled down’, issues of identity preservation, resistance and accommodation, together with a saliently negative representation of wrongdoings by the Soviet system, still prevail. On the one hand, this testifies to the resilience of an established tradition in the textbook genre in general. On the other hand, it reflects the dominance of an ethnocentric tradition in Estonian history textbook writing. The paper discusses the implications of these findings for interethnic relations in Estonia.
YAP and TAZ regulate adherens junction dynamics and endothelial cell distribution during vascular development
Authors: Neto Filipa , Klaus-Bergmann Alexandra , Ong Yu Ting , Alt Silvanus , Vion Anne-Clémence , Szymborska Anna , Carvalho Joana R , Hollfinger Irene , Bartels-Klein Eireen , Franco Claudio A , Potente Michael , Gerhardt Holger
Published: February 2018

Formation of blood vessel networks by sprouting angiogenesis is critical for tissue growth, homeostasis and regeneration. How endothelial cells arise in adequate numbers and arrange suitably to shape functional vascular networks is poorly understood. Here we show that YAP/TAZ promote stretch-induced proliferation and rearrangements of endothelial cells whilst preventing bleeding in developing vessels. Mechanistically, YAP/TAZ increase the turnover of VE-Cadherin and the formation of junction associated intermediate lamellipodia, promoting both cell migration and barrier function maintenance. This is achieved in part by lowering BMP signalling. Consequently, the loss of YAP/TAZ in the mouse leads to stunted sprouting with local aggregation as well as scarcity of endothelial cells, branching irregularities and junction defects. Forced nuclear activity of TAZ instead drives hypersprouting and vascular hyperplasia. We propose a new model in which YAP/TAZ integrate mechanical signals with BMP signaling to maintain junctional compliance and integrity whilst balancing endothelial cell rearrangements in angiogenic vessels.
Sea cucumbers reduce chromophoric dissolved organic matter in aquaculture tanks
Authors: Sadeghi-Nassaj Seyed Mohammad , Catalá Teresa S. , Álvarez Pedro A. , Reche Isabel
Published: February 2018

Background

Mono-specific aquaculture effluents contain high concentrations of nutrients and organic matter, which affect negatively the water quality of the recipient ecosystems. A fundamental feature of water quality is its transparency. The fraction of dissolved organic matter that absorbs light is named chromophoric dissolved organic matter (CDOM). A sustainable alternative to mono-specific aquaculture is the multitrophic aquaculture that includes species trophically complementary named “extractive” species that uptake the waste byproducts. Sea cucumbers are recognized as efficient extractive species due to the consumption of particulate organic matter (POM). However, the effects of sea cucumbers on CDOM are still unknown.

Methods

During more than one year, we monitored CDOM in two big-volume tanks with different trophic structure. One of the tanks (−holothurian) only contained around 810 individuals of Anemonia sulcata, whereas the other tank (+holothurian) also included 90 individuals of Holothuria tubulosa and Holothuria forskali. We routinely analyzed CDOM absorption spectra and determined quantitative (absorption coefficients at 325 nm) and qualitative (spectral slopes) optical parameters in the inlet waters, within the tanks, and in their corresponding effluents. To confirm the time-series results, we also performed three experiments. Each experiment consisted of two treatments: +holothurians (+H) and –holothurians (−H). We set up three +H tanks with 80 individuals of A. sulcata and 10 individuals of H. tubulosa in each tank and four –H tanks that contained only 80 individuals of A. sulcata.

Results

In the time-series, absorption coefficients at 325 nm (a325) and spectral slopes from 275 to 295 nm (S275−295) were significantly lower in the effluent of the +holothurian tank (average: 0.33 m−1 and 16 µm−1, respectively) than in the effluent of the −holothurian tank (average: 0.69 m−1 and 34 µm−1, respectively), the former being similar to those found in the inlet waters (average: 0.32 m−1 and 22 µm−1, respectively). This reduction in the absorption of the dissolved organic matter appears to be mediated by the POM consumption by holothurians. The experiments confirmed the results observed in the time-series. The a325 and S275−295 values were significantly lower in the treatment with holothurians than in the treatment without holothurians indicating a reduction in the concentration of chromophoric organic compounds, particularly of low molecular weight.

Discussion

Consequently, sea cucumbers appear to improve water transparency in aquaculture tanks. The underlying mechanism of this improvement might be related to the POM consumption by holothurians, which reduces the concentration of CDOM derived from POM disaggregation or to the direct assimilation of dissolved compounds of low molecular weight as chromophoric amino acids.
Application of an Anisotropy‐Based Correction to Relative Paleointensity Estimates of Experimentally Deposited Sediments
Authors: Molinek F. R. , Bilardello D.
Published: February 2018

The magnetization of a sediment is acquired when ferromagnetic detrital particles align with the Earth's magnetic field as they settle through the water column. The relative continuity and ubiquity of the global sedimentary record makes sediments and sedimentary rocks an ideal target for studies of relative paleointensity (RPI) and the evolution of the Earth's magnetic field. However, processes including flocculation, contact with the substrate, bioturbation, and compaction disrupt this alignment, leading to shallowed remanent inclinations and biased intensities. The inclination of the depositional field also exerts an influence on the remanent intensity, thus affecting RPI estimates and leading to complications in interpretations of the global record. We present a series of 12 deposition experiments conducted in varying field strengths and inclinations, from which we determine RPI estimates. We then correct these estimates using a modified anisotropy‐based inclination correction technique. We find experimentally that our correction reduces the inclination dependence of relative paleointensity while preserving the RPI's dependence on the depositional intensity. Our results suggest that the anisotropy‐based correction should improve RPI estimates obtained from natural sediments and sedimentary rocks.
Modeling Slab‐Slab Interactions: Dynamics of Outward Dipping Double‐Sided Subduction Systems
Authors: Király Ágnes , Holt Adam F. , Funiciello Francesca , Faccenna Claudio , Capitanio Fabio A.
Published: February 2018

Slab‐slab interaction is a characteristic feature of tectonically complex areas. Outward dipping double‐sided subduction is one of these complex cases, which has several examples on Earth, most notably the Molucca Sea and Adriatic Sea. This study focuses on developing a framework for linking plate kinematics and slab interactions in an outward dipping subduction geometry. We used analog and numerical models to better understand the underlying subduction dynamics. Compared to a single subduction model, double‐sided subduction exhibits more time‐dependent and vigorous toroidal flow cells that are elongated (i.e., not circular). Because both the Molucca and Adriatic Sea exhibit an asymmetric subduction configuration, we also examine the role that asymmetry plays in the dynamics of outward dipping double‐sided subduction. We introduce asymmetry in two ways; with variable initial depths for the two slabs (“geometric” asymmetry), and with variable buoyancy within the subducting plate (“mechanical” asymmetry). Relative to the symmetric case, we probe how asymmetry affects the overall slab kinematics, whether asymmetric behavior intensifies or equilibrates as subduction proceeds. While initial geometric asymmetry disappears once the slabs are anchored to the 660 km discontinuity, the mechanical asymmetry can cause more permanent differences between the two subduction zones. In the most extreme case, the partly continental slab stops subducting due to the unequal slab pull force. The results show that the slab‐slab interaction is most effective when the two trenches are closer than 10–8 cm in the laboratory, which is 600–480 km when scaled to the Earth.
The Magmatic Gas Signature of Pacaya Volcano, With Implications for the Volcanic CO2 Flux From Guatemala
Authors: Battaglia A. , Bitetto M. , Aiuppa A. , Rizzo A.L. , Chigna G. , Watson I. M. , D'Aleo R. , Juárez Cacao F. J. , de Moor M. J.
Published: February 2018

Pacaya volcano in Guatemala is one of the most active volcanoes of the Central American Volcanic Arc (CAVA). However, its magmatic gas signature and volatile output have received little attention to date. Here, we present novel volcanic gas information from in‐situ (Multi‐GAS) and remote (UV camera) plume observations in January 2016. We find in‐plume H2O/SO2 and CO2/SO2 ratios of 2‐20 and 0.6‐10.5, and an end‐member magmatic gas signature of 80.5 mol. % H2O, 10.4 mol. % CO2, and 9.0 mol. % SO2. The SO2 flux is evaluated at 885 ± 550 tons/d. This, combined with co‐acquired volcanic plume composition, leads to H2O and CO2 fluxes of 2,230 ± 1,390 and 700 ± 440, and a total volatile flux of ∼3,800 tons/d. We use these results in tandem with previous SO2 flux budgets for Fuego and Santiaguito to estimate the total volcanic CO2 flux from Guatemala at ∼1,160 ± 600 tons/day. This calculation is based upon CO2/total S (St) ratios for Fuego (1.5 ± 0.75) and Santiaguito (1.4 ± 0.75) inferred from a gas (CO2/St ratio) versus trace‐element (Ba/La ratio) CAVA relationship. The H2O‐poor and low CO2/St ratio (∼1.0‐1.5) signature of Pacaya gas suggests dominant mantle‐wedge derivation of the emitted volatiles. This is consistent with 3He/4He ratios in olivine hosted fluid inclusions (FIs), which range between 8.4 and 9.0 Ra (being Ra the atmospheric 3He/4He ratio) at the upper limit of MORB range (8 ± 1 Ra). These values are the highest ever measured in CAVA and among the highest ever recorded in arc volcanoes worldwide, indicating negligible 4He contributions from the crust/slab.
Phytoplankton Community Structure in 2011–2013 Compared to the Extratropical Warming Event of 2014–2015
Authors: Du X. , Peterson W. T.
Published: February 2018

Coastal waters of the Northern California Current experienced “normal” ocean conditions in 2011–2012, weak upwelling in 2013–2014, then suddenly warmed in September 2014. The response of phytoplankton community structure to contrasting ocean conditions was determined from samples collected off Newport, Oregon. Cluster analysis identified three prominent phytoplankton community types: one that occurred during the upwelling season characterized by the highest abundance and diversity of diatoms, a preupwelling/relaxation community characterized by lower abundance, lowest diversity of diatoms and dinoflagellates, and another one associated with the warm anomalies from September 2014 through 2015 with reduced diatom abundance and diversity but the highest dinoflagellate diversity. The changes of diatom and dinoflagellate community were correlated with local factors (silicate, silicate: nitrate ratios, temperature, and salinity), and with the Pacific Decadal Oscillation.
Space‐Weathered Anorthosite as Spectral D‐Type Material on the Martian Satellites
Authors: Yamamoto S. , Watanabe S. , Matsunaga T.
Published: February 2018

Spectral D‐type asteroids are characterized by dark, red‐sloped, and featureless spectra at visible and near‐infrared wavelengths and are thought to be composed of rocks rich in organic compounds. The Martian satellites, Phobos and Deimos, spectrally resemble D‐type asteroids, suggesting that they are captured D‐type asteroids from outside the Martian system. Here we show that the spectral features of lunar space‐weathered anorthosite are consistent with D‐type spectra, including those of Phobos and Deimos. This can also explain the distinct spectral features on Phobos, the red and blue units, as arising from different degrees of space weathering. Thus, D‐type spectra of the Martian satellites can be explained by space‐weathered anorthosite, indicating that D‐type spectra do not necessarily support the existence of organic compounds, which would be strong evidence for the capture scenario.
Response of the Land‐Atmosphere System Over North‐Central Oklahoma During the 2017 Eclipse
Authors: Turner D. D. , Wulfmeyer V. , Behrendt A. , Bonin T. A. , Choukulkar A. , Newsom R. K. , Brewer W. A. , Cook D. R.
Published: February 2018

On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse's effect on the land‐atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north‐central Oklahoma. The observations showed that turbulent fluxes of heat and momentum at the surface responded quickly to the change in solar radiation. The decrease in the sensible heat flux resulted in a decrease in the air temperature below 200 m, and a large decrease in turbulent motions throughout the boundary layer. Furthermore, the turbulent mixing in the boundary layer lagged behind the change in the surface fluxes, and this lag depended on the height above the surface. The turbulent motions increased and the convective boundary layer was reestablished as the sensible heat flux recovered.
MMS Examination of FTEs at the Earth's Subsolar Magnetopause
Authors: Akhavan‐Tafti M. , Slavin J. A. , Le G. , Eastwood J. P. , Strangeway R. J. , Russell C. T. , Nakamura R. , Baumjohann W. , Torbert R. B. , Giles B. L. , Gershman D. J. , Burch J. L.
Published: February 2018

Determining the magnetic field structure, electric currents, and plasma distributions within flux transfer event (FTE)‐type flux ropes is critical to the understanding of their origin, evolution, and dynamics. Here the Magnetospheric Multiscale mission's high‐resolution magnetic field and plasma measurements are used to identify FTEs in the vicinity of the subsolar magnetopause. The constant‐α flux rope model is used to identify quasi‐force free flux ropes and to infer the size, the core magnetic field strength, the magnetic flux content, and the spacecraft trajectories through these structures. Our statistical analysis determines a mean diameter of 1,700 ± 400 km (~30 ± 9 di) and an average magnetic flux content of 100 ± 30 kWb for the quasi‐force free FTEs at the Earth's subsolar magnetopause which are smaller than values reported by Cluster at high latitudes. These observed nonlinear size and magnetic flux content distributions of FTEs appear consistent with the plasmoid instability theory, which relies on the merging of neighboring, small‐scale FTEs to generate larger structures. The ratio of the perpendicular to parallel components of current density, RJ, indicates that our FTEs are magnetically force‐free, defined as RJ < 1, in their core regions (<0.6 Rflux rope). Plasma density is shown to be larger in smaller, newly formed FTEs and dropping with increasing FTE size. It is also shown that parallel ion velocity dominates inside FTEs with largest plasma density. Field‐aligned flow facilitates the evacuation of plasma inside newly formed FTEs, while their core magnetic field strengthens with increasing FTE size.
The Influence of IMF By on the Bow Shock: Observation Result
Authors: Wang M. , Lu J. Y. , Kabin K. , Yuan H. Z. , Liu Z.‐Q. , Zhao J. S. , Li G.
Published: February 2018

In this study we use the bow shock crossings contained in the Space Physics Data Facility database, collected by four spacecraft (IMP 8, Geotail, Magion‐4, and Cluster1) to analyze the effect of the interplanetary magnetic field (IMF) By component on the bow shock position and shape. Although the IMF Bz component is usually considered much more geoeffective than By, we find that the dayside bow shock is more responsive to the eastward component of the IMF than the north‐south one. We believe that the explanation lies in the changes that the Bz component induces on the magnetopause location and shape, which largely compensate the corresponding changes in the dayside bow shock location. In the tail, we find that the bow shock cross section is elongated roughly in the direction perpendicular to the IMF direction, which agrees with earlier modeling studies.
Comparison of Relativistic Microburst Activity Seen by SAMPEX With Ground‐Based Wave Measurements at Halley, Antarctica
Authors: Douma Emma , Rodger Craig J. , Clilverd Mark A. , Hendry Aaron T. , Engebretson Mark J. , Lessard Marc R.
Published: February 2018

Relativistic electron microbursts are a known radiation belt particle precipitation phenomenon; however, experimental evidence of their drivers in space have just begun to be observed. Recent modeling efforts have shown that two different wave modes (whistler mode chorus waves and electromagnetic ion cyclotron (EMIC) waves) are capable of causing relativistic microbursts. We use the very low frequency/extremely low frequency Logger Experiment and search coil magnetometer at Halley, Antarctica, to investigate the ground‐based wave activity at the time of the relativistic microbursts observed by the Solar Anomalous Magnetospheric Particle Explorer. We present three case studies of relativistic microburst events, which have one or both of the wave modes present in ground‐based observations at Halley. To extend and solidify our case study results, we conduct superposed epoch analyses of the wave activity present at the time of the relativistic microburst events. Increased very low frequency wave amplitude is present at the time of the relativistic microburst events, identified as whistler mode chorus wave activity. However, there is also an increase in Pc1–Pc2 wave power at the time of the relativistic microburst events, but it is identified as broadband noise and not structured EMIC emissions. We conclude that whistler mode chorus waves are, most likely, the primary drivers of relativistic microbursts. However, case studies confirm the potential of EMIC waves as an occasional driver of relativistic microbursts.
Measurement of Individual H+ and O+ Ion Temperatures in the Topside Ionosphere
Authors: Hsu Chih‐Te , Heelis Roderick A.
Published: February 2018

Plasma temperatures in the ionosphere are associated with both the dynamics and spatial distribution of the neutral and charge particles. During the daytime, temperatures are determined by solar energy inputs and energy exchange between charged and neutral particles. Plasma transport parallel to the magnetic field adds another influence on temperatures through adiabatic processes that are most evident during the nighttime. Previous observations suggest that the topside H+ temperature (TH+) should reside between the O+ temperature (TO+) and the electron temperature (Te), and further calculations confirm the preferential heat transfer from the electrons to H+ in the topside. In this work we implement a more sophisticated analysis procedure to extract individual mass‐dependent ion temperatures from the retarding potential analyzer measurements on the DMSP F15 satellite. The results show that the daytime TH+ is a few hundred degrees higher than TO+ at all longitudes. The nighttime temperature difference between TH+ and TO+ is indicative of mass‐dependent adiabatic heating and cooling processes across the equatorial region. The ion temperatures and measured plasma flows present clear longitudinal variations that are associated with magnetic declination.
Longitudinal Thin Structure of Equatorial Plasma Depletions Coincidently Observed by Swarm Constellation and all‐Sky Imager
Authors: Xiong Chao , Xu Jiyao , Wu Kun , Yuan Wei
Published: February 2018

The lower pair satellites of Swarm mission, flying side‐by‐side and separated by 1.4° in longitude (about 150 km), usually observed equatorial plasma depletions (EPDs) showing quite different structures, and sometime even only one satellite observed EPD. In this study, we provided 6‐h continuous observations of EPDs on the night of 23–24 September 2014, from an all‐sky imager located at Fuke (geographic:19.5°N,109.1°E), south of China. From the airglow images the EPDs were found with longitudinal extensions of about 50 km and all tilted from northwest to southeast direction. We further checked the in situ electron density simultaneously measured by the Swarm lower pair satellites and found the differences of Swarm in situ electron densities explained well by the longitudinally thin structure of EPDs observed from the all‐sky imager. During later periods the bifurcation and merging were observed by the airglow images, and it was the first time to report both processes in the evolution of one EPD. The bifurcation was first observed at the higher‐latitude part, and then observed at lower latitudes of EPD. The subbranches generated through bifurcation showed even thinner longitudinal extension of about 20–30 km, and later the subbranches started to merge with each other, forming a really complicated mesh of depleted regions.