bluuebunny/crossref_metadata_2025 huggingface dataset:
Intercomparison of the comparative reactivity method (CRM) and pump–probe technique for measuring total OH reactivity in an urban environment
Authors: Hansen R. F. , Blocquet M. , Schoemaecker C. , Léonardis T. , Locoge N. , Fittschen C. , Hanoune B. , Stevens P. S. , Sinha V. , Dusanter S.
Published: October 2015

Abstract. The investigation of hydroxyl radical (OH) chemistry during intensive field campaigns has led to the development of several techniques dedicated to ambient measurements of total OH reactivity, which is the inverse of the OH lifetime. Three techniques are currently used during field campaigns, including the total OH loss rate method, the pump–probe method, and the comparative reactivity method. However, no formal intercomparison of these techniques has been published so far, and there is a need to ensure that measurements of total OH reactivity are consistent among the different techniques. An intercomparison of two OH reactivity instruments, one based on the comparative reactivity method (CRM) and the other based on the pump–probe method, was performed in October 2012 in a NOx-rich environment, which is known to be challenging for the CRM technique. This study presents an extensive description of the two instruments, the CRM instrument from Mines Douai (MD-CRM) and the pump–probe instrument from the University of Lille (UL-FAGE), and highlights instrumental issues associated with the two techniques. It was found that the CRM instrument used in this study underestimates ambient OH reactivity by approximately 20 % due to the photolysis of volatile organic compounds (VOCs) inside the sampling reactor; this value is dependent on the position of the lamp within the reactor. However, this issue can easily be fixed, and the photolysis of VOCs was successfully reduced to a negligible level after this intercomparison campaign. The UL-FAGE instrument may also underestimate ambient OH reactivity due to the difficulty to accurately measure the instrumental zero. It was found that the measurements are likely biased by approximately 2 s-1, due to impurities in humid zero air. Two weeks of ambient sampling indicate that the measurements performed by the two OH reactivity instruments are in agreement, within the measurement uncertainties for each instrument, for NOx mixing ratios up to 100 ppbv. The CRM technique has hitherto mainly been used in low-NOx environments, i.e. environments with ambient NOx mixing ratios lower than a few ppbv, due to a measurement artifact generated by ambient NO inside the sampling reactor. However, this study shows that this technique can also be used under NOx-rich conditions if a NOx-dependent correction is carefully applied on the OH reactivity measurements. A full suite of 52 VOCs, NOx, and other inorganic species were monitored during this intercomparison. An investigation of the OH reactivity budget for this urban site suggests that this suite of trace gases can account for the measured total OH reactivity.
A new method for the absolute radiance calibration for UV–vis measurements of scattered sunlight
Authors: Wagner T. , Beirle S. , Dörner S. , Penning de Vries M. , Remmers J. , Rozanov A. , Shaiganfar R.
Published: October 2015

Abstract. Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds, and the shortwave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV–vis instruments that measure the spectrally resolved sky radiance, for example zenith sky differential optical absorption spectroscopy (DOAS) instruments or multi-axis (MAX)-DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method, clear-sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about < 7 %. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements be constant and known.
Retrieval of xCO2 from ground-based mid-infrared (NDACC) solar absorption spectra and comparison to TCCON
Authors: Buschmann M. , Deutscher N. M. , Sherlock V. , Palm M. , Warneke T. , Notholt J.
Published: October 2015

Abstract. High resolution solar absorption spectra, taken within the Network for the Detection of Atmospheric Composition Change (NDACC) in the mid-infrared spectral region are used to infer partial or total column abundances of many gases. In this paper we present the retrieval of a column averaged mole fraction of carbon dioxide from NDACC-IRWG spectra taken with a Fourier-Transform-Infra-Red (FTIR) spectrometer at the site in Ny-Ålesund, Spitsbergen. The retrieved time series is compared to co-located standard TCCON measurements of total column CO2. Comparing the NDACC and TCCON retrievals we find that the sensitivity of the NDACC retrieval is lower in the troposphere (by a factor of two) and higher in the stratosphere, compared to TCCON. Thus, the NDACC retrieval is less sensitive to tropospheric changes (e.g. the seasonal cycle) in the column average.
Relating field-aligned beams to inverted-V structures and visible auroras
Authors: Lee E. , Parks G. K. , Fu S. Y. , Fillingim M. , Cui Y. B. , Hong J. , Dandouras I. , Rème H.
Published: October 2015

Abstract. The ion composition experiment on Cluster measures 3-D distributions in one spin of the spacecraft (4 s). These distributions often measure field-aligned ion beams (H+, He+ and O+) accelerated out of the ionosphere. The standard model of these beams relies on a quasi-static U-shaped potential model. The beams contain important information about the structure and distribution of the U-shaped potential structures. For example, a simple beam with a narrow velocity range tells us that the particles are accelerated going through a quasi-static U-shaped potential structure localized in space. A more complex beam with a large range of velocities varying smoothly (a few tens of kilometers per second to > 100 km s−1) tells us that the potential structure is extended and distributed along the magnetic field. The Cluster experiment has now revealed new features about the beams. Some beams are broken into many individual structures each with their own velocity. The U-shaped potential model would interpret the new features in terms of particles accelerated by narrow isolated potential structures maintained over an extended region of the magnetic field. Another interpretation is that these features arise as Cluster traverses toward the center of a small-scale U-shaped potential region detecting particles accelerated on different equipotential contours. The estimate of the distance of the adjacent contours is ~ 590–610 m at a Cluster height of ~ 3.5 RE. The observed dimensions map to ~ 295–305 m in the ionosphere, suggesting Cluster has measured the potential structure of an auroral arc.
Reconstruction of flood events based on documentary data and transnational flood risk analysis of the Upper Rhine and its French and German tributaries since AD 1480
Authors: Himmelsbach I. , Glaser R. , Schoenbein J. , Riemann D. , Martin B.
Published: October 2015

Abstract. This paper presents the long-term analysis of flood occurrence along the southern part of the Upper Rhine River system and of 14 of its tributaries in France and Germany covering the period starting from 1480 BC. Special focus is given on the temporal and spatial variations of flood events and their underlying meteorological causes over time. Examples are presented of how long-term information about flood events and knowledge about the historical aspect of flood protection in a given area can help to improve the understanding of risk analysis and therefor transnational risk management. Within this context, special focus is given to flood vulnerability while comparing selected historical and modern extreme events, establishing a common evaluation scheme. The transnational aspect becomes especially evident analyzing the tributaries: on this scale, flood protection developed impressively different on the French and German sides. We argue that comparing high technological standards of flood protection, which were initiated by the dukes of Baden on the German side starting in the early 19th century, misled people to the common belief that the mechanical means of flood protection like dams and barrages can guarantee the security from floods and their impacts. This lead to widespread settlements and the establishment of infrastructure as well as modern industries in potentially unsafe areas until today. The legal status in Alsace on the French side of the Rhine did not allow for continuous flood protection measurements, leading to a constant – and probably at last annoying – reminder that the floodplains are a potentially unsafe place to be. From a modern perspective of flood risk management, this leads to a significant lower aggregation of value in the floodplains of the small rivers in Alsace compared to those on the Baden side – an interesting fact – especially if the modern European Flood directive is taken into account.
Recent changes in climate, hydrology and sediment load in the Wadi Abd, Algeria (1970–2010)
Authors: Achite M. , Ouillon S.
Published: October 2015

Abstract. Here we investigate the changes of temperature, precipitation, river runoff and sediment transport in the Wadi Abd in NW Algeria over a time series of 40 hydrological years (1970–2010). Temperature increased and precipitation decreased with the reduction in rainfall being relatively higher during the rainy season. A shift towards an earlier onset of first rains during summer was also found with cascading effects on hydrology (hydrological regimes, vegetation etc) and thus on erosion and sediment yield. During the 1980s, the flow regime shifted from perennial to intermittent with an amplification of the variations of discharge and a modification of the sediment regime with higher and more irregular suspended particulate flux. Sediment flux was shown to almost double every decade from 1970s to 2000s. The sediment regime shifted from two equivalent seasons of sediment delivery (spring and autumn) to a single major season regime. In 2000s, autumn produced over 4 times more sediment than spring. The enhanced scatter denotes an increase of hysteresis phenomena in the Wadi Abd that is probably related to the change in the hydrologic regime. The increased erosion of the watershed is accompanied by a decrease in the coefficient b of its rating curves and a decrease in the erosive power of the river. At the end of the period, due to the irregularity of the discharge, the ability of a rating curve to derive suspended sediment concentration from river discharge was poor.
Effects of land use changes on the dynamics of selected soil properties in the Northeast Wollega, Ethiopia
Authors: Adugna A. , Abegaz A.
Published: October 2015

Abstract. Land use change can have negative or positive effects on soil quality. Our objective was to assess the effects of land uses changes on the dynamics of selected soil physical and chemical properties. Soil samples were collected from three adjacent land uses, namely forestland, grazing land and cultivated land at 0–15 cm depth, and tested in National Soil Testing Center, Ministry of Agriculture of Ethiopia. Percentage changes of soil properties on cultivated and grazing land was computed and compared to forestland, and Analysis of variance (ANOVA) was used to test the significance of the changes. The results indicate that sand, silt, SOM, N, pH, CEC and Ca were the highest in forestlands. Mg was the highest in grazing land while clay, P and K were the highest in cultivated land. The percentage changes in sand, clay, SOM, pH, CEC, Ca and Mg were higher in cultivated land than the change in grazing land compared to forestland, except P. In terms of relationship between soil properties; SOM, N, CEC and Ca were strongly positively correlated with most of soil properties while P and silt have no significant relationship with any of other considered soil properties. Clay has negative correlation with all of soil properties. Generally, cultivated land has the least concentration of soil physical and chemical properties except clay and AP which suggest increasing degradation rate in soils of cultivated land. So as to increase SOM and other nutrients in the soil of cultivated land, integrated implementation of land management through compost, cover crops, manures, minimum tillage and crop rotation; and liming to increase soil pH are suggested.
Dialogical Grammar: Varieties of Dialogue in Wittgenstein’s Methodology
Authors: Lemberger Dorit
Published: October 2015

The dialogical character of Wittgenstein’s Philosophical Investigations has received scant attention in the literature, given the work’s status in his total oeuvre, and is dismissed as a marginal as compared to the other differences between the Tractatus and the Investigations. The main lines of interpretation that have been proposed see dialogue as a rhetorical technique intended to present erroneous positions and then refute them, as an exemplification of what can be expressed in language (McGinn 1997; Rhees 1998), or as a reflection of Wittgenstein’s informal teaching method (Malcolm 2001; Savickey et al. 1990). The present article adopts the perspective that Wittgenstein’s use of dialogue makes it possible to track the various modes of language-acts, consonant with his directions to examine the daily use of language (Wittgenstein 2009, §116 and esp. §132), “when language is, as it were, idling.” In his later inquiries, Wittgenstein frequently considers the nature of mental states, accompanied by an attempt to characterize the differences between them while at the same time dealing with the cases in which it is difficult to distinguish them. In this process he made a variety of uses of dialogue, each of which embodies a different aspect of language action.  Subsequently I will demonstrate that these different uses are not haphazard. A scrutiny of the nature of the dialogue can help us understand the nature of the activity carried out of the state of consciousness. Finally, I propose a distinction among three main types of dialogue: technical, conversational, and reflexive.
A Comprehensive Review on Fishery Biology of Catfishes
Authors: Amin Muhammad , Shoaib Mohammad , Nabi Ghulam , Ahmed Naveed , Kifayatullah Muhammad
Published: October 2015

Cat fish exploit a large diversity of both plant and animal protein, and adapt harsh environmental conditions as they have the ability to take atmospheric oxygen. Marine catfish tolerate a broad range of salinities between Open Ocean and fresh water. The entire catfishes have soft as well as scaleless body, are greatly appreciated by consumers and maintain healthy in both fresh and dried condition. In this review article various aspects of cat fish has been discussed.
He Will Rock You:
Authors: Lockhart Jessica J.
Published: October 2015

This article draws on medieval accounts of athletic sport and its literary depictions to examine a tradition of Havelok the Dane's athletic prowess that runs across the Lai d'Haveloc, the Middle English Havelok, and numerous chronicles. Robert Mannyng describes a physical remnant of this athletic tradition: a stone lying in Lincoln Castle said to have been thrown by Havelok. By reading Havelok's stone not merely as a relic of a past king but as marking a playspace—the imagined site of a former game—we may understand the stone as a point of intersection between the pleasurable activities of contemporary sport and historicist imagining. In the romances, Havelok's athletic wonders highlight the social effects of wonder as sport. In turn, Mannyng's stone creates an imaginative playspace within his Chronicle: one that exploits an affective connection between the wonders of athletic spectating and an imaginative engagement with history.
Redeeming the Dog:
Authors: Huber Emily Rebekah
Published: October 2015

In the Middle English romance Sir Gowther, Gowther's redemption is contingent upon the reform of his animality as well as of his humanity. This article discusses Gowther's similarity to three different cultural representations of dogs in medieval culture: the folk type of the demonic hellhound, the secular and revered hunting hound of the nobility, and the figure of the holy greyhound. Gowther's canine self is imagined by way of his muteness as well as his appetites; these functions are instrumental in the reform of his relationships to both humans and animals in the romance.
Turned to Fables:
Authors: Lavinsky David
Published: October 2015

This essay takes as its context the discourse of sacerdotal authority and deviance explicitly dramatized by the Pardoner's claims for the efficacy of his speech. It considers this topic in relation to medieval discussions of officium, and how the same category in Wycliffite thought initially invites us to dismiss the Pardoner as a false preacher. Yet there is still a sense in which he preaches truly; key here, rather than orthodox concepts of officium, are his texts: fables and exempla. Tracking how these were implicated in contemporary crises of language, form, and truthful speech, the essay goes on to argue that the Pardoner's tale of avarice stages a case for the efficacious work of literature.
The Influence of Different Retting Processes on the Strength of Fibres obtained from Poliostigma raticulatum, Grewia mollis, Cissus populnea and Hibiscus sabdariffa
Authors: Dass Peter Michael , Akinterinwa Ayodele , Ndahi Adamu Jibrin , Abba Shamsu
Published: October 2015

The extraction of vegetable fibres from different parts of plants has been a major focal point in the search for natural fibres that would substitute synthetic fibres. Fibres from Poliostigma reticulatum, Grewia mollis, Cissus populnea and Hibiscus sabdariffa were extracted by water and chemical retting. In chemical retting different concentrations of NaOH and NH4OH were used. The extracted fibres were further purified and their tensile strength measured. The pH of water was measured as retting progresses and observed to increase as the retting time increases. This was ascribed to the secretion of enzymes by microorganisms as they acted on the mucilaginous matter of the bast with the resultant loosening of the fibres. The tensile strength of the fibres was determined using the Shirley Testometric 220D and was observed to gradual decline as the retting time increases. This was attributed to the continual removal of non-fibrous matter and the freeing of the fibres in the composite. However, beyond the fifth week of retting, no appreciable change in tensile strength was observed. This suggested that most of the non-fibrous matter have been solublized and utilized as source of nutrients and energy by the microorganisms. Acidic metabolites were produced due to microbial activities may have changed the pH of the medium and subsequently hindered their growth. In chemical retting, as the concentration of the medium increases the strength of the fibres decreases to a minimum then remain constant. This was accredited to the breakdown of inter- molecular bonds between non-fibrous substances and the fibres. And subsequently, the non-fibrous components separate from the fibres and dissolved in the medium revealing the actual fibres strength. It was therefore, opined that retted fibres in water, 5% NH4OH and 15% NaOH are clearer and lustrous for all sample except those from Kargo.
Conformational Analysis of Rat Seminal Vesicle Secretory Protein 4, an Intrinsically Disordered Protein Having Interesting Pharmacological Properties
Authors: Susan Costantini , Gautam Vasu , Maria Salvatore , Birolo Leila , Longobardi Sara , Giovanni Colonna
Published: October 2015

Rat seminal vesicle protein 4 (RSV4) is a member of the seminal vesicle protein family present in rats, 90 residues long. When secreted, it is involved in many functions related to the reproduction ranging from semen coagulation to sperm capacitation, but its fragments have also shown in vitro pharmacological properties such as anti-inflammatory and pro-coagulant activity, important in the cancer development. However, no three-dimensional model of this protein is yet available probably because of the presence of intrinsic disorder in the structure. In this article we report structural studies in solution of RSV4 by SEC (size exclusion chromatography) and CD (circular dichroism). In solution the monomer is highly flexible and poorly organized with the presence of highly fluctuating helical segments and, as also suggested by SEC, is classifiable as NU-PMG (natively unfolded pre-molten globule). The lack of a cooperative sigmoidal structural transition induced by thermal and GdmCl perturbation in monomer supports the poor structural organization expected for a NU-PMG conformational model. The structure of RSV4 monomer was modeled computationally and subjected to molecular dynamics simulations to study its conformational changes and energetic stability.
Anders omgaan met interculturele conflicten
Authors: Vanfraechem Inge
Published: October 2015

Alternatively handling intercultural conflicts

This article describes the European research project ALTERNATIVE, which studies the possible implementation of restorative justice approaches in intercultural conflicts. Besides theoretical research into concepts such as justice, security, conflict (transformation) and restorative justice, action-research was implemented in four diverse intercultural settings (Austria, Hungary, Serbia and Northern Ireland). In order to compare those settings, an innovative comparative research method was developed through which the various realities are ‘thickly described’ within evaluation grids. The article describes the different aspects of the research and reflects upon the question whether a more broad understanding of restorative justice, surpassing the judicial sector and aspects, is emerging.
Diversiteitsbewuste communicatie. Niet culturen, maar mensen ontmoeten elkaar
Authors: Hoffman Edwin
Published: October 2015

Intercultural communication. Not cultures but people meet

Intercultural communication is often portrayed as communication between people with a different ethnic or national background. People may interpret differences and misunderstandings arising in communication as especially grand and problematic. Sometimes, people see the reason for a difference in opinion or the conflict to be situated within the other (often national or ethnic) culture. They see themselves and others as a member of a different group, with a different culture and thus claim the differences to be related to the culture and not the individual person (culturalising or culturistic approach). This approach entails certain risks when it is seen as a condition to be able to speak to others and when handled as the sole frame of reference to interpret people’s meaning-making. An alternative approach can be found in a systemic and communication-theory approach, linking it to intersectionality, pluralism, diversity competence and the TOPOI model, as this article explains.
Conflictbeleving en herstelrecht in Brussel
Authors: Huysmans Minne , Claes Erik
Published: October 2015

Experiencing conflict and restorative justice in Brussels

This article stems from a practice-oriented research on restorative justice and perceptions of conflict in a poor neighbourhood in Brussels: the Anneessens district. The first part of the article focuses on the conceptual shift from a crime-oriented towards a conflict-oriented restorative justice, including the search for a user-friendly working definition of ‘conflict’. The classical restorative justice story receives a facelift in order to address metropolitan challenges. The second part analyses 41 walking interviews of residents, focusing on conflict themes and zones. The third part cautiously checks the working definition in the frame of the analysed data. A provisional conclusion entails that the notion of crime and its related meanings should not be discarded too quickly.
Material Speculation: Actual Artifacts for Critical Inquiry
Authors: Wakkary Ron , Odom William , Hauser Sabrina , Hertz Garnet , Lin Henry
Published: October 2015

Speculative and fictional approaches have long been implemented in human-computer interaction and design techniques through scenarios, prototypes, forecasting, and envisionments. Recently, speculative and critical design approaches have reflectively explored and questioned possible, and preferable futures in HCI research. We propose a complementary concept – material speculation – that utilizes actual and situated design artifacts in the everyday as a site of critical inquiry. We see the literary theory of possible worlds and the related concept of the counterfactual as informative to this work. We present five examples of interaction design artifacts that can be viewed as material speculations. We conclude with a discussion of characteristics of material speculations and their implications for future design-oriented research.
Multi-Lifespan Information System Design
Authors: Friedman Batya , Nathan Lisa P. , Yoo Daisy
Published: October 2015

Contemporary information ecosystems evolve at lightening speed. Last year’s cutting edge innovations are this year’s standard fare and next year’s relics. An information innovation can be implemented, made available through the Internet, and appropriated within 24 hours. Yet, significant societal problems engage much longer timeframes. In 2010 Friedman and Nathan pointed to a fundamental disconnect between mainstream design thinking and these longer-term problems. To address this disconnect, they proposed a multi-lifespan information system design framing.

This workshop builds on previous work by the organizers and others to: (1) elaborate and identify new opportunities and challenges in taking up multi-lifespan information system design problems, and (2) generate critical and constructive discussions for further development of multi- lifespan information system design thinking. 
Temaet folkemord i forfatterskapet til Tore Linné Eriksen
Authors: Rønning Balsvik Randi
Published: October 2015

This article points to the responsibility historians have in the formation of what we may call the collective memory of persons, groups and states. What are the images of “the other” conveyed in textbooks and media? In Norway, the historian Tore Linné Eriksen has – more than any other scholar – used his research, writings and enormous capacity for work to educate students, youth and the public in general and to create a more just image of “the other”. His driving force has been an extraordinary ability to be at the forefront in spotting international research, as well as his sense of justice and respect for the non-western world. His last extensive work on global history (Globalhistorie 1750–1900) clearly demonstrates these capabilities.

In the early 1980s, long before the wave of genocide studies after the Rwanda catastrophe of 1994, Eriksen’s two works on Namibia –Namibia: Kolonialisme, apartheid og frigjøringskamp i det sørlige Afrika (1982) and The Political Economy of Namibia: An Annotated Critical Bibliography (1985) – used the concept of genocide to describe German conduct in Namibia in the early 20th century. In 2007, Eriksen published his book about what he calls the first genocide of the 20th century, Det første folkemordet i det tjuende århundret. Namibia 1903–1908. German and African history is woven into the question of whether the dangerous relations that developed between German settlers and Africans can be labelled genocide. The present article attempts to present Eriksen’s arguments. An introductory section deals with the trends in the international research literature and establishes a link between colonialism and genocide. In 2008, Eriksen’s article on the extinction of the Herero people in Namibia – “Utslettelse av Hererofolket i Namibia 1903– 1908” – was published in Bernt Hagtvets collection of articles, Folkemordenes svarte bok. The following year, Tore Linné Eriksen’s article in the journal Historisk Tidsskrift (2009) on genocide in a comparative colonial perspective won the prize for best article of the year.

In Eriksen’s global history, referred to above, it is stated and shown that, to a certain extent, there is disagreement among historians as to what can be called genocide. What about the extinction of indigenous peoples due to diseases in the wake of European immigration? In his use of the term, Eriksen is more cautious than the authors of some of the works he refers to. The present article argues for more attention to be paid to the concept of “intent” when it comes to interpreting the tragic outcomes of conflict.
Exploring the effect of current sheet thickness on the high‐frequency Fourier spectrum breakpoint of the solar wind
Authors: Borovsky Joseph E. , Podesta John J.
Published: October 2015

The magnetic power spectrum of the solar wind at 1 AU exhibits a breakpoint at a frequency of about 0.1–1 Hz, with the spectrum being steeper above the breakpoint than below the breakpoint. Because magnetic discontinuities contain much of the Fourier power in the solar wind, it is suspected that current sheet thicknesses (i.e., discontinuity thicknesses) may play a role in determining the frequency of this breakpoint. Using time series measurements of the solar wind magnetic field from the Wind spacecraft, the effect of current sheet thicknesses on the breakpoint is investigated by time stretching the solar wind time series at the locations of current sheets, effectively thickening the current sheets in the time series. This localized time stretching significantly affects the magnetic power spectral density of the solar wind in the vicinity of the high‐frequency breakpoint: a substantial fraction of the Fourier power at the breakpoint frequency is contained in current sheets that occupy a small fraction of the spatial volume of the solar wind. It is concluded that current sheet thickness appears to play a role in determining the frequency fB of the high‐frequency breakpoint of the magnetic power spectrum of the solar wind. This analysis of solar wind data is aided by comparisons with power spectra generated from artificial time series.
Long‐term variations in the intensity of polar cap plasma flows inferred from SuperDARN
Authors: Koustov A. V. , Fiori R. A. D. , Abooali zadeh Z.
Published: October 2015

Multiyear (1995–2013) velocity data collected by the Super Dual Auroral Network (SuperDARN) HF radars are considered to investigate the diurnal, seasonal, and solar cycle variation of the polar cap plasma flow speed. By considering monthly data sets, we show that the flows are systematically faster in the dawn/prenoon sector. The effect is particularly strong for interplanetary magnetic field (IMF) Bz < 0, By > 0 and in summer months. For Bz < 0, the flow speed increases with intensification of the IMF transverse component Bt at a rate of 20–30 m/s/nT during near noon summer hours. The dependence is weaker for other seasons and away from noon. For IMF Bz > 0, the flow speed response to the increase in Bt is weak. Despite the general sensitivity of the flow speed to Bt intensity and season, the speed for specific IMF bins and seasons or the speed averaged over a year does not change much over the solar cycle. Overall, the velocity is reduced during years of lowest solar activity, but a progression of the effect throughout the solar cycle was not observed. Inferred diurnal and seasonal trends of the polar cap flow speed are generally consistent with variations in the occurrence of VHF echoes whose onset depends on the strength of the ionospheric electric field or equivalently the magnitude of the plasma flow speed.
Impact breaching of Europa's ice: Constraints from numerical modeling
Authors: Cox Rónadh , Bauer Aaron W.
Published: October 2015

Numerical simulations show that impactors can penetrate Europa's ice, creating conduits to the underlying ocean. Breaching becomes inevitable when transient cavity depth exceeds 90% of ice thickness. Results indicate that a 0.5 km comet would penetrate 5 km ice, and a 5 km comet could breach 40 km ice. Thinner ice would be breached more frequently, thicker ice less so, but even the 40 km upper estimates for ice thickness would be penetrated by comets with recurrence intervals less than 250 Ma. If actual ice thickness is 8–13 km (indicated by comparing Europan and simulated crater geometries), the ocean could be exposed by impactors in the range 0.7–1.5 km, which have recurrence intervals ≈3 to 7 Ma. Thus, it seems that Europa's ice has been penetrated often in the past and possibly in geologically recent time. The largest known impact sites, Callanish and Tyre, probably represent transition from craters to penetrating impacts. The geomorphic expression of full penetration must exist on the surface; chaos terrain is a candidate. Astrobiological materials could be transported to the ocean via these impact‐created conduits.
Associated congenital anomalies in infants with isolated gastroschisis: A single‐institutional experience
Authors: Corona‐Rivera Jorge Román , Nieto‐García Rafael , López‐Marure Eloy , Cárdenas‐Ruiz Velasco Juan José , Bobadilla‐Morales Lucina , Mellín‐Sánchez Estrella Lizbeth , Aguirre‐Guillén Rafael L. , Pérez‐Ramírez René O. , Zapata‐Aldana Eugenio , Sandoval‐Talamantes Ana K. , Solís‐Ledezma Susana , Corona‐Rivera Alfredo , Gómez‐Ruiz Larissa M.
Published: October 2015

The aim of our study was to determine the frequency and type of associated congenital anomalies in patients with isolated gastroschisis born at the Dr. Juan I. Menchaca Civil Hospital of Guadalajara (Guadalajara, México), and to explore its possible association with the included outcome variables. One hundred‐eight cases with isolated gastroschisis were reviewed from 2009 to 2014. The occurrence of intestinal and extraintestinal associated anomalies (either secondary or primary) was prospectively assessed. The type of gastroschisis, length of hospital stay (LOS), and in‐hospital mortality were outcome variables for statistical analysis. Of infants with gastroschisis, 52 (48.1%) had one or more associated anomalies (AA), with increased odds in males (OR = 2.3, 95%CI: 1.1–5.0). AA classified, as secondary and primary were present in 34.3 and 5.6% of patients, respectively. Of secondary AA, 25.9% were intestinal anomalies, and 17.6% were extraintestinal. Primary AA were congenital heart disease (n = 3), meningomyelocele, and hydrocephaly and amniotic band sequence in one instance, respectively. Multivariate logistic regression showed that secondary AA (both intestinal and extraintestinal) were associated with complex gastroschisis, prolonged LOS, and in‐hospital death, whereas primary AA were not related to a worse outcome. Our results highlight the pathogenic importance of properly investigating and categorizing the presence of others secondary or primary AA when diagnosis of gastroschisis is made. © 2015 Wiley Periodicals, Inc.
A highly active multi‐usable palladium pyridylfluorene film‐based catalyst for C–C cross‐coupling reactions
Authors: Zhao Xiuhua , Zhao Yayun , Zhang Jie , Li Xing
Published: October 2015

The two terminal pyridyl nitrogen atoms of 2,7‐bis(4‐pyridyl)fluorene (1) were coordinated to Pd(II) ions to give self‐assembled, multilayer films using the layer‐by‐layer (LbL) method. The films were prepared by alternately dipping the substrate, pre‐coated with a polyethyleneimine layer, in aqueous solutions of PdCl2 and ethanol solutions of 1. The resulting films were characterized using UV–visible absorption spectroscopy, atomic force microscopy (AFM), X‐ray photoelectron spectroscopy, scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP‐AES). UV–visible spectra and SEM images show almost uniform growth of the film in a near ideal LbL manner. AFM images show that nanostructured aggregates of Pd(II) complexes form on the surface. With an increase in the number of Pd(II)/1 bilayers, more particulate aggregates are distributed on the surface. When released from the substrate, the Pd(II) complex nanostructure shows high catalytic activity for Suzuki–Miyaura and Mizoroki–Heck cross‐coupling reactions. The catalyst loading is as low as 9.1 × 10−3 mol% Pd, as measured using ICP‐AES, and high turnover numbers of up to 1.08 × 104 are obtained. Copyright © 2015 John Wiley & Sons, Ltd.
An Improved Dual Unscented Kalman Filter for State and Parameter Estimation
Authors: Yu Anxi , Liu Ye , Zhu Jubo , Dong Zhen
Published: October 2015

A dual unscented Kalman filter (DUKF) is used to estimate the state and the parameter simultaneously via two parallel unscented Kalman filters. The original DUKF usually has performance degradation as a result of assuming the control inputs of each filter are constant, which usually are disturbance inputs or systematic measurement errors in the control system. An improved dual unscented Kalman filter (IDUKF) with random control inputs and sequential dual estimation structure is derived and applicable to the system in which the parameter is linearly observed and uncorrelated with the state. The accuracy, observability, and computational efficiency of the new filter are discussed. Then, the expansibility of the IDUKF for nonlinear parameter observed substructures is investigated. Finally, two simulation experiments about space target tracking and typical time series filtering are shown. The theoretical analyses and simulation results demonstrate the following. (1) the IDUKF can obtain higher accuracy than the original DUKF and a comparative accuracy with the JUKF (joint unscented Kalman filter) when the state and the parameter are not strongly correlated; (2) the IDUKF has better applicability than the DUKF when the state is correlated with the unknown parameter; (3) when the modeling error is not ignorable, the IDUKF is more robust and more accurate than the JUKF due to lower sensitivity to the modeling error.
Functional localization of the human color center by decreased water displacement using diffusion‐weighted fMRI
Authors: Williams Rebecca J. , Reutens David C. , Hocking Julia
Published: October 2015

Introduction

Decreased water displacement following increased neural activity has been observed using diffusion‐weighted functional MRI (DfMRI) at high b‐values. The physiological mechanisms underlying the diffusion signal change may be unique from the standard blood oxygenation level‐dependent (BOLD) contrast and closer to the source of neural activity. Whether DfMRI reflects neural activity more directly than BOLD outside the primary cerebral regions remains unclear.

Methods

Colored and achromatic Mondrian visual stimuli were statistically contrasted to functionally localize the human color center Area V4 in neurologically intact adults. Spatial and temporal properties of DfMRI and BOLD activation were examined across regions of the visual cortex.

Results

At the individual level, DfMRI activation patterns showed greater spatial specificity to V4 than BOLD. The BOLD activation patterns were more prominent in the primary visual cortex than DfMRI, where activation was localized to the ventral temporal lobe. Temporally, the diffusion signal change in V4 and V1 both preceded the corresponding hemodynamic response, however the early diffusion signal change was more evident in V1.

Conclusions

DfMRI may be of use in imaging applications implementing cognitive subtraction paradigms, and where highly precise individual functional localization is required.
Wnt5A exerts immunomodulatory activity in the human ovarian cancer cell line SKOV‐3
Authors: Arabzadeh Somayeh , Hossein Ghamartaj , Zarnani Amir Hassan
Published: October 2015

The purpose of this study was three fold: (1) to reveal the implications of Wnt5A for cytokine and chemokine production by human ovarian cancer cell line SKOV‐3 cells, (2) to determine the influence of Wnt5A on chemotactic SKOV‐3 cell migration, and (3) to assess the effect of inflammatory mediators on Wnt5A expression levels and to describe its underlying molecular mechanisms. A cytokine array was performed using a conditioned medium harvested from SKOV‐3 cells transfected with specific siRNAs against Wnt5A or with scrambled siRNA and a transfection reagent alone as negative controls for 48 h. Chemotactic cell migration was performed using transwells. Inflammation‐induced Wnt5A expression was determined by treating cells with recombinant human (rh) IL‐1β, IFNβ, or TNFα alone or in combination with STAT3 and NF‐κB inhibitors for different time durations. The cytokine array showed the suppression of GCSF, GM‐CSF, IL‐1α, IL‐2, IL‐13, and MCP‐3 production, whereas cell RANTES and IL‐7 showed increased levels in Wnt5A knock‐down cells compared with those in controls. Chemotactic migration decreased significantly when the conditioned medium from Wnt5A knock‐down cells was applied to the upper chamber of the transwell. Compared with the control, there were 30‐fold and five‐fold increases in Wnt5A mRNA levels in cells treated, with rhIL‐1β and rhIFNβ, respectively after 8 h (P < 0.001). Compared with the control, TNF‐α had a 1.8‐fold increased levels of Wnt5A mRNA after 4 h (P < 0.01). Both NF‐κB and STAT3 inhibitors decreased inflammation‐induced Wnt5A expression. This study revealed a previously unrecognized immunomodulatory role of endogenous Wnt5A in ovarian cancer cells, which could further influence chemotactic cell migration.
Mechanistic Understanding of the Divergent Cyclizations of o‐Alkynylbenzaldehyde Acetals and Thioacetals Catalyzed by Metal Halides
Authors: Mi Yanhua , Zhou Tao , Wang Kung‐Pern , Lee Daesung , Xia Yuanzhi
Published: October 2015

Invited for the cover of this issue are the groups of Yuanzhi Xia at Wenzhou University (P.R. China) and Daesung Lee at University of Illinois at Chicago (USA). The image depicts the mechanistic understanding of the regiodivergent cyclizations of­ o‐alkynylbenzaldehyde acetals and thioacetals catalyzed by metal halides. Read the full text of the article at 10.1002/chem.201502469.
Neuropeptide F neurons modulate sugar reward during associative olfactory learning of Drosophila larvae
Authors: Rohwedder Astrid , Selcho Mareike , Chassot Bérénice , Thum Andreas S.
Published: October 2015

All organisms continuously have to adapt their behavior according to changes in the environment in order to survive. Experience‐driven changes in behavior are usually mediated and maintained by modifications in signaling within defined brain circuits. Given the simplicity of the larval brain of Drosophila and its experimental accessibility on the genetic and behavioral level, we analyzed if Drosophila neuropeptide F (dNPF) neurons are involved in classical olfactory conditioning. dNPF is an ortholog of the mammalian neuropeptide Y, a highly conserved neuromodulator that stimulates food‐seeking behavior. We provide a comprehensive anatomical analysis of the dNPF neurons on the single‐cell level. We demonstrate that artificial activation of dNPF neurons inhibits appetitive olfactory learning by modulating the sugar reward signal during acquisition. No effect is detectable for the retrieval of an established appetitive olfactory memory. The modulatory effect is based on the joint action of three distinct cell types that, if tested on the single‐cell level, inhibit and invert the conditioned behavior. Taken together, our work describes anatomically and functionally a new part of the sugar reinforcement signaling pathway for classical olfactory conditioning in Drosophila larvae. J. Comp. Neurol. 523:2637–2664, 2015. © 2015 Wiley Periodicals, Inc.
Precision‐tuning and hybrid pricer for closed‐form solution‐based Heston calibration
Authors: Brugger Christian , Liu Gongda , De Schryver Christian , Wehn Norbert
Published: October 2015

Calibration methods are the heart of modeling any financial process. While for the Heston model (semi) closed‐form solutions exist for simple products, their evaluation involves complex functions and infinite integrals. So far, these integrals can only be solved with time‐consuming numerical methods. For that reason, calibration consumes a large portion of available compute power in the daily finance business.

However, more and more theoretical and practical subtleties have been discovered over the years, and today, a large number of calibration methods are available. Currently, there is no clear indication which numerical method should be used for a specific calibration purpose under given speed and accuracy constraints. With this publication, we aim at closing this gap. We derive a novel methodology for systematically finding the best methods for a well‐defined accuracy target. For a practical setup, we study the available popular closed‐form solutions and integration algorithms. In total, we compare 14 numerical methods, including adaptive quadrature and Fourier methods. For a target accuracy of 10−3, we show that adaptive Gauss–Kronrod methods are best on CPUs for the unrestricted parameter set. Furthermore, we introduce hybrid pricer methods that combine quadrature and fast Fourier transform pricers, what gives us another 2.4× speedup. Copyright © 2015 John Wiley & Sons, Ltd.
Multistrain probiotic production by co‐culture fermentation in a lab‐scale bioreactor
Authors: Jangra Manoj , Belur Prasanna D. , Oriabinska Larysa B. , Dugan Olexii M.
Published: October 2015

Most commercial probiotic products intended for pharmaceutical applications consist of combinations of probiotic strains and are available in various forms. The development of co‐culture fermentation conditions to produce probiotics with the correct proportion of viable microorganisms would reduce multiple operations and the associated costs. The aim of this study was to develop a fermentation medium and process to achieve biomass comprising the desired proportion of two probiotic strains in co‐culture. Initially, a quantification medium was developed, and the method was optimized to allow the quantification of each strain's biomass in a mixture. The specific growth rates of Lactobacillus delbrueckii spp. bulgaricus and Lactobacillus plantarum were determined in media with different carbon sources. The inoculum volume was optimized to achieve equal proportion of biomass in co‐culture fermentation in test tubes. Next, fermentation was carried out in a 3‐L bioreactor. A biomass concentration of 2.06 g/L, with L. delbrueckii spp. bulgaricus and L. plantarum in the ratio of 47%:53% (by weight), was achieved with concomitant production of 12.69 g/L of lactic acid in 14 h. The results show that with careful manipulation of process conditions, it is possible to achieve the desired proportion of individual strains in the final biomass produced by co‐culture fermentation. This process may serve as a model to produce multistrain probiotic drugs at industrial scale.