bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on Operations: IGAPS: A Taxonomy and Facet Classification System
Authors: Pell John , Huppuch Meghan
Published: July 2017

This paper describes an assessment of the information management practices at International Planned Parenthood Federation/Western Hemisphere Region and the development and implementation of an information management pilot for that organization. The pilot included the development of a taxonomy to classify the organization’s documents, training in basic citation practices, and a decentralized model for building an organized library of documents within the citation management software Mendeley. The authors discuss the pilot’s taxonomy within the context of literature on taxonomy development and offers strategic recommendations for improving the information management practices of not-for-profit organizations that lack dedicated information management staff.
Book Review: Managing Metadata in Web-scale Discovery Systems
Authors: Hagen Brianne
Published: July 2017

Managing metadata in libraries today presents challenges to information professionals concerned with quality control, providing relevant search results, and taming the volume of items available for access in a web-scale discovery system. No longer are libraries limited to the collections they “own.” Catalogers and metadata professionals now assume the responsibility of providing access to millions of resources, often with limitations on who can access that resource. Relationships with vendors provide opportunities to help manage the gargantuan scale of information. Of course those opportunities come with their own problems as relationships among vendors can be contentious, leaving metadata managers to figure out quality control on a grand scale. In addition to this politicized information landscape, new ways of managing and creating metadata are emerging, leaving information professionals with the task of managing multiple schema in different formats. The essays in Managing Metadata in Web-scale Discovery Systems seek to address issues in managing the large scale of information overwhelming catalogers today, with potential solutions for taming the beast of exponentially increasing data.
Book Review: Linked Data for Cultural Heritage (An ALCTS Monograph)
Authors: Ojennus Paul
Published: July 2017

While linked data has been on the horizon for librarians, archivists, and other curators of cultural memory nearly since it was first expounded fifteen years ago, for many it has remained an abstraction.1 Jones and Seikel present six contributions by those engaged in implementing linked data projects across the cultural heritage landscape, seeking to bridge the gap between the idea of linked data and concrete applications that can be adopted at a local level. The focus is not on the technology of linked data, though each of the chapters discuss some technical issues relevant to the projects, but rather on how the technology can overcome the limits of earlier cultural metadata encoding systems (e.g., MARC) and what new challenges and opportunities it presents. By presenting studies of real-world implementations of linked data, this volume effectively communicates the progress made and a sense of what the technology could do for a local collection.
Book Review: Managing Digital Cultural Objects: Analysis, Discovery, and Retrieval
Authors: Washington Anne
Published: July 2017

Over the past twenty years, libraries, archives, museums, and other institutions have made hundreds of thousands of digitized and born digital cultural heritage objects available online. This momentum is not likely to slow anytime soon. Digitization programs continue to convert analog media, and efforts are ramping up to procure and preserve born digital material. While discussion of technical specifications and skills to support these processes are critical, there is a growing body of research beyond these topics. Some scholars and practitioners have turned their attention towards theory, assessment, and innovative analysis and Managing Digital Cultural Objects: Analysis, Discovery, and Retrieval adds to this conversation.
Expanding HIV testing and linkage to care in southwestern Uganda with community health extension workers
Authors: Asiimwe Stephen , Ross Jennifer M. , Arinaitwe Anthony , Tumusiime Obed , Turyamureeba Bosco , Roberts D. Allen , O’Malley Gabrielle , Barnabas Ruanne V.
Published: July 2017

Introduction: Achieving the UNAIDS goals of 90–90‐90 will require more than doubling the number of people accessing HIV care in Uganda. Community‐based programmes for entry into HIV care are effective strategies to expand access to HIV care, but few programmes have been evaluated with a particular focus on scale‐up.

Methods: Integrated Community Based Initiatives, a Uganda‐based non‐governmental organization, designed and implemented a programme of community‐based HIV counselling and testing and facilitated linkage to care utilizing community health extension workers (CHEWs) in rural Sheema District, Uganda. CHEWs performed programme activities during 1 October 2015 through 31 March 2016. Outcomes for this evaluation were (1) the number of people tested for HIV, and (2) the proportion of those testing positive who were seen at an ART clinic within three months of their positive test, and (3) the cost of the programme per person newly diagnosed with HIV. Microcosting methods were used to calculate the programme costs. Program scalability factors were evaluated using a published framework.

Results: Sixty‐two CHEWs attended a five‐day training that introduced the biology of HIV, the conduct of confidential HIV testing, HIV prevention messages, and linkage, referral, and reporting requirements. CHEWs received a $30 monthly stipend and a field testing kit that included a bicycle, field bag, umbrella, gumboots, reporting booklet, pens, and HIV testing materials. Trained CHEWs tested 43,696 persons for HIV infection during the six‐month programme period. Nine‐hundred seventy‐four participants (2.2%) were identified as HIV positive, and 623 participants (64%) were linked to HIV care. An estimated 69% of adult residents received testing as part of this campaign. The programme cost $3.02 per person test, $135.70 per positive person identified, and $212.15 per HIV‐positive person linked to care.

Conclusions: Lay community health extension workers (CHEWs) can be rapidly trained to scale‐up home‐based HIV testing and counselling (HTC) and linkage to care in a high‐quality and low‐cost manner to large numbers of people in a rural, high burden setting. A combination HIV testing approach, such as adding partner testing to community‐based testing, could increase the proportion of HIV‐positive persons identified.
Effect of frequency of clinic visits and medication pick‐up on antiretroviral treatment outcomes: a systematic literature review and meta‐analysis
Authors: Mutasa‐Apollo Tsitsi , Ford Nathan , Wiens Matthew , Socias Maria Eugenia , Negussie Eyerusalem , Wu Ping , Popoff Evan , Park Jay , Mills Edward J. , Kanters Steve
Published: July 2017

Introduction: Expanding and sustaining antiretroviral therapy (ART) coverage may require simplified HIV service delivery strategies that concomitantly reduce the burden of care on the health system and patients while ensuring optimal outcomes. We conducted a systematic review to assess the impact of reduced frequency of clinic visits and drug dispensing on patient outcomes.

Methods: As part of the development process of the World Health Organization antiretroviral (ARV) guidelines, we systematically searched medical literature databases for publications up to 30 August 2016. Information was extracted on trial characteristics, patient characteristics and the following outcomes: mortality, morbidity, treatment adherence, retention, patient and provider acceptability, cost and patients exiting the programme. When feasible, conventional pairwise meta‐analyses were conducted.

Results and discussion: Of 6443 identified citations, 21 papers, pertaining to 16 studies, were included in this review, with 11 studies contributing to analyses. Although analyses were feasible, they were limited by the sparse evidence base, despite the importance of the research area, and relatively low quality. Comparative analyses of eight studies reporting on frequency of clinic visits showed that less frequent clinic visits led to higher odds of being retained in care (odds ratio [OR]: 1.90; 95% CI: 1.21–2.99). No differences were found with respect to viral failure, morbidity or mortality; however, most estimates were favourable to reduced clinic visits. Reduced frequency of ARVs pick‐ups showed a trend towards better retention (OR: 1.93; 95% CI: 0.62–6.04). Strategies using community support tended to have better outcomes; however, their implementation varied, particularly by location. External validity may be questionable.

Conclusions: Our systematic review suggests that reduction of clinical visits (and likely ARVs pick‐ups) may improve clinical outcomes, and that they are a viable option to relieve health systems and reduce burden of care for PLHIV. Strategies aimed at reducing clinic visits or drug refill services should focus on stable patients who are virally suppressed, tolerant to their drug regimen and fully adherent. These strategies may be critical to the current changes taking place in HIV treatment policy; thus, due to the data limitations, further high quality research is needed to inform policy and programmatic interventions.
The future of the teaching profession from the perspective of students with a Major in Education
Authors: Campos Céspedes Jensy , Solano Gutiérrez Walter
Published: July 2017

The article offers the results obtained in a study where, through the application of a survey and the development of a discussion forum with students from education majors, information about their perceptions with regard to four axes related to the future of the teaching profession was obtained, as follows: the teacher profile, the student characteristics, the participation of the family and the community in the education process and the curricular changes. From the study, it can be observed that the family and the community are perceived as the organizations with greater trends towards change as a consequence of the technological development and the globalization processes of societies, whilst the teacher profile, the concept of student, of school and curricula, tend to remain within the status quo. The perceptions shown by the future teachers who participated in the study demand relevant changes in the training processes of the education professionals.
Effectiveness of Tutoring to Improve Academic Performance in Nursing Students at the University of Seville
Authors: Guerra-Martín María Dolores , Lima-Serrano Marta , Lima-Rodríguez Joaquín Salvador
Published: July 2017

In response to the increase of Higher Education support provided to tutoring programs, this paper presents the design, implementation and evaluation of a tutoring program to improve the academic performance of at-risk students enrolled in the last year of a nursing degree characterized by academic failure (failed courses). A controlled experimental study was carried out to evaluate a tutoring program that included a minimum of nine meetings performed by an expert professor as tutor. A questionnaire for assessing the academic needs was designed and interventions were performed when responses were: nothing, a little or something. Medium to large effects were found in the progress of failed course to passed course (p =.000, rφ = .30), improving the information about courses (p < .001, d = 2.01), the information comprehension (p < .001, d = 0.85) and the strategies to improve academic performance (p < .001, d = 1.37). The intervention group students’ response highlighted program satisfaction and effectiveness. The significance of the study lies in reinforcing the formal tutoring as a tool to improve academic performance in at-risk students.
Can the integration of a PLE in an e-portfolio platform improve generic competences?
Authors: Galván-Fernández Cristina , Rubio-Hurtado María José , Martínez-Olmo Francesc , Rodríguez-Illera José Luis
Published: July 2017

The study analyzes the improvement in generic competences through e-portfolio/PLE platform and didactic planning. The new version of the platform, Digital Folder, contains utilities for students and teachers and some PLE components that help the learning process through e-portfolios. Didactic planning is compared for students from the University of Vic and the University of Barcelona, with a total of 61 participants. A questionnaire has been applied for measuring the use of functions and how much these functions aid in the improvement of the generic competences (reflection, planning and selection of information). The results confirm that the most helpful functions for students are: the Schedule, the Academic tasks, the Teacher’s portfolio and Dialogue with the teacher. However, the implication of these functions in the improvement of the competences depends on didactic planning overall for reflection on learning.
Social Learning Analytics in Higher Education. An experience at the Primary Education stage
Authors: Díaz-Lázaro José Javier , Solano Fernández Isabel M. , del Mar Sánchez Vera María
Published: July 2017

The concept of Learning Analytics, as we understand it today, is relatively new but the practice of evaluating user behavior is not innovative. For years, technological development, along with other educational aspects, have encouraged, developed and facilitated this practice as a way of providing a personalized quality experience to students. The main goal of this study, carried out in the Primary Education Degree of the University of Murcia, was to research, from the perspective of Social Learning Analytics, how students learn and collaborate in online environments, specifically through their use of social media. With the idea of improving and optimizing future teaching experiences, a pilot study was conducted using weblog, Twitter and Facebook to work with different topics on the subject. The method used in this research was a participant observation and the analysis performed was both quantitative, based mainly on the data gathered from the learning analytics, and qualitative (analyzing students’ content from comments). Results show that there was greater interaction on Facebook than weblogs, where students interacted to deal with aspects related to the learning process and the topic of the subject. This exchange of information grew during the development of the experience. In addition, learning analytics shows that there is a relationship between group members and their interaction and behavior in networks.
Covariation in patterns of turbulence‐driven hyporheic flow and denitrification enhances reach‐scale nitrogen removal
Authors: Li Angang , Aubeneau Antoine F. , Bolster Diogo , Tank Jennifer L. , Packman Aaron I.
Published: July 2017

Coinjections of conservative tracers and nutrients are commonly used to assess travel time distributions and nutrient removal in streams. However, in‐stream tracer data often lack information on long‐term hyporheic storage, and removal rate coefficients are often assumed to be uniform despite plentiful evidence that microbially mediated transformations, such as denitrification, exhibit strong spatial variability in the hyporheic zone. We used process‐based particle‐tracking simulations to explore the coupled effects of spatial patterns in hyporheic flow and denitrification on reach‐scale nitrogen removal. We simulated whole‐stream nitrogen dynamics with exponential, layered, and uniform profiles of hyporheic denitrification. We also simulated nitrogen dynamics in Little Rabbit Creek, an agricultural headwater stream in the Kalamazoo River Basin (Michigan, USA) where vertical profiles of hyporheic denitrification were measured in situ. Covariation between pore water velocity and mixing causes rapid exchange in the near‐surface bioactive region and substantially prolonged exchange in the deeper hyporheic. Patterns of hyporheic denitrification covary with patterns of hyporheic flow. This covariation directly controls tailing of in‐stream breakthrough curves and hence reach‐scale nutrient removal. Enhanced denitrification near the sediment‐water interface strongly tempers breakthrough curve tails at time scales associated with flushing of the near‐surface region, while more spatially uniform denitrification causes weaker tempering over a wider range of hyporheic exchange time scales. At the reach scale, overall nitrogen removal increases with heterogeneity of hyporheic denitrification, indicating that covariation between flow and denitrification—particularly the rapid flushing of highly bioactive regions near the sediment‐water interface—controls whole‐stream transformation rates.
Simulation of Mercury's magnetosheath with a combined hybrid‐paraboloid model
Authors: Parunakian David , Dyadechkin Sergey , Alexeev Igor , Belenkaya Elena , Khodachenko Maxim , Kallio Esa , Alho Markku
Published: July 2017

In this paper we introduce a novel approach for modeling planetary magnetospheres that involves a combination of the hybrid model and the paraboloid magnetosphere model (PMM); we further refer to it as the combined hybrid model. While both of these individual models have been successfully applied in the past, their combination enables us both to overcome the traditional difficulties of hybrid models to develop a self‐consistent magnetic field and to compensate the lack of plasma simulation in the PMM. We then use this combined model to simulate Mercury's magnetosphere and investigate the geometry and configuration of Mercury's magnetosheath controlled by various conditions in the interplanetary medium. The developed approach provides a unique comprehensive view of Mercury's magnetospheric environment for the first time. Using this setup, we compare the locations of the bow shock and the magnetopause as determined by simulations with the locations predicted by stand‐alone PMM runs and also verify the magnetic and dynamic pressure balance at the magnetopause. We also compare the results produced by these simulations with observational data obtained by the magnetometer on board the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft along a dusk‐dawn orbit and discuss the signatures of the magnetospheric features that appear in these simulations. Overall, our analysis suggests that combining the semiempirical PMM with a self‐consistent global kinetic model creates new modeling possibilities which individual models cannot provide on their own.
On the relation of earthquake stress drop and ground motion variability
Authors: Oth Adrien , Miyake Hiroe , Bindi Dino
Published: July 2017

One of the key parameters for earthquake source physics is stress drop since it can be directly linked to the spectral level of ground motion. Stress drop estimates from moment corner frequency analysis have been shown to be extremely variable, and this to a much larger degree than expected from the between‐event ground motion variability. This discrepancy raises the question whether classically determined stress drop variability is too large, which would have significant consequences for seismic hazard analysis. We use a large high‐quality data set from Japan with well‐studied stress drop data to address this issue. Nonparametric and parametric reference ground motion models are derived, and the relation of between‐event residuals for Japan Meteorological Agency equivalent seismic intensity and peak ground acceleration with stress drop is analyzed for crustal earthquakes. We find a clear correlation of the between‐event residuals with stress drops estimates; however, while the island of Kyushu is characterized by substantially larger stress drops than Honshu, the between‐event residuals do not reflect this observation, leading to the appearance of two event families with different stress drop levels yet similar range of between‐event residuals. Both the within‐family and between‐family stress drop variations are larger than expected from the ground motion between‐event variability. A systematic common analysis of these parameters holds the potential to provide important constraints on the relative robustness of different groups of data in the different parameter spaces and to improve our understanding on how much of the observed source parameter variability is likely to be true source physics variability.
Characterization of the 3‐D fracture setting of an unstable rock mass: From surface and seismic investigations to numerical modeling
Authors: Colombero C. , Baillet L. , Comina C. , Jongmans D. , Vinciguerra S.
Published: July 2017

The characterization of the fracturing state of a potentially unstable rock cliff is a crucial requirement for stability assessments and mitigation purposes. Classical measurements of fracture location and orientation can however be limited by inaccessible rock exposures. The steep topography and high‐rise morphology of these cliffs, together with the widespread presence of fractures, can additionally condition the success of geophysical prospecting on these sites. In order to mitigate these limitations, an innovative approach combining noncontact geomechanical measurements, active and passive seismic surveys, and 3‐D numerical modeling is proposed in this work to characterize the 3‐D fracture setting of an unstable rock mass, located in NW Italian Alps (Madonna del Sasso, VB). The 3‐D fracture geometry was achieved through a combination of field observations and noncontact geomechanical measurements on oriented pictures of the cliff, resulting from a previous laser‐scanning and photogrammetric survey. The estimation of fracture persistence within the rock mass was obtained from surface active seismic surveys. Ambient seismic noise and earthquakes recordings were used to assess the fracture control on the site response. Processing of both data sets highlighted the resonance properties of the unstable rock volume decoupling from the stable massif. A finite element 3‐D model of the site, including all the retrieved fracture information, enabled both validation and interpretation of the field measurements. The integration of these different methodologies, applied for the first time to a complex 3‐D prone‐to‐fall mass, provided consistent information on the internal fracturing conditions, supplying key parameters for future monitoring purposes and mitigation strategies.
Understanding the spatial variation of sea level rise in the North Sea using satellite altimetry
Authors: Sterlini Paul , Le Bars Dewi , de Vries Hylke , Ridder Nina
Published: July 2017

This paper examines the spatial variation of sea surface height trends in the North Sea Basin as seen by satellite altimetry and assesses its underlying causes. Changes in the potential temperature and salinity of the North Sea are transposed into corresponding changes in sea surface height and regional anomalies of linear sea level trend calculated. The same is carried out for the meteorological processes which act on the sea surface. The steric and meteorological regional sea level rise anomalies are summed with those from contributions from land ice and compared against the values seen by satellite altimetry over the period 1993–2014. Results show that there is good agreement between the observations and the reconstruction. The local meteorological contribution appears to be most important in describing regional variation in linear sea level rise and is reinforced with a local halosteric contribution which shows a similar spatial pattern.
Seasonal cycle of hydrography on the eastern shelf of the Filchner Trough, Weddell Sea, Antarctica
Authors: Ryan S. , Hattermann T. , Darelius E. , Schröder M.
Published: July 2017

New 2 year long records from three moorings, located at
S along the eastern flank and shelf of the Filchner Trough, give insight in the seasonal cycle of hydrography to a region where Modified Warm Deep Water (MWDW) enters the southern Weddell Sea continental shelf, possibly reaching the Filchner Ronne Ice Shelf, the biggest ice shelf (by volume) in Antarctica. A persistent northward flow of Ice Shelf Water (ISW) is found along the eastern flank of the trough at 400 m depth, while the data on the eastern shelf indicate a seasonal cycle, characterized by four phases. A distinct warm inflow period (separated in two phases), with maximum temperatures of
C, appears to be related to the seasonal heaving of the Antarctic Slope Front thermocline along the continental shelf break further north and a seasonal extension of the ISW layer onto the eastern shelf. The density gradients between the ISW in the trough and the MWDW on the adjacent shelf drive the southward flow during these phases. A flow reversal is found in winter, ceasing the southward flow along the eastern flank of the trough. Weaker density gradients between the trough and the shelf during winter allow a westward flow, partly driven by a N‐S density gradient, existing across the eastern shelf during this time. From spring through to summer, the ISW layer in the trough extends onto the eastern shelf where it occupies the bottom layer at our moorings, associated with northward flow.
Types of lightning discharges that abruptly terminate enhanced fluxes of energetic radiation and particles observed at ground level
Authors: Chilingarian A. , Khanikyants Y. , Mareev E. , Pokhsraryan D. , Rakov V. A. , Soghomonyan S.
Published: July 2017

We present ground‐based measurements of thunderstorm‐related enhancements of fluxes of energetic radiation and particles that are abruptly terminated by lightning discharges. All measurements were performed at an altitude of 3200 m above sea level on Mount Aragats (Armenia). Lightning signatures were recorded using a wideband electric field measuring system with a useful frequency bandwidth of 50 Hz to 12 MHz and network of five electric field mills, three of which were installed at the Aragats station, one at the Nor Amberd station (12.8 km from Aragats), and one at the Yerevan station (39 km from Aragats). We observed that the flux‐enhancement termination was associated only with close (within 10 km or so of the particle detector) negative CGs and normal‐polarity ICs; that is, with lightning types which reduce the upward directed electric field below the cloud and hence suppress the acceleration of electrons toward the ground.
New insights into the column CH2O/NO2 ratio as an indicator of near‐surface ozone sensitivity
Authors: Schroeder Jason R. , Crawford James H. , Fried Alan , Walega James , Weinheimer Andrew , Wisthaler Armin , Müller Markus , Mikoviny Tomas , Chen Gao , Shook Michael , Blake Donald R. , Tonnesen Gail S.
Published: July 2017

Satellite‐based measurements of the column CH2O/NO2 ratio have previously been used to estimate near‐surface ozone (O3) sensitivity (i.e., NOx or VOC limited), and the forthcoming launch of air quality‐focused geostationary satellites provides a catalyst for reevaluating the ability of satellite‐measured CH2O/NO2 to be used in this manner. In this study, we use a 0‐D photochemical box model to evaluate O3 sensitivity and find that the relative rate of radical termination from radical‐radical interactions to radical‐NOx interactions (referred to as LROx/LNOx) provides a good indicator of maximum O3 production along NOx ridgelines. Using airborne measurements from NASA's Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relative to Air Quality (DISCOVER‐AQ) deployments in Colorado, Maryland, and Houston, we show that in situ measurements of CH2O/NO2 can be used to indicate O3 sensitivity, but there is an important “transition/ambiguous” range whereby CH2O/NO2 fails to categorize O3 sensitivity, and the range and span of this transition/ambiguous range varies regionally. Then, we apply these findings to aircraft‐derived column density measurements from DISCOVER‐AQ and find that inhomogeneities in vertical mixing in the lower troposphere further degrades the ability of column CH2O/NO2 to indicate near‐surface O3 sensitivity (i.e., the transition/ambiguous range is much larger than indicated by in situ data alone), and we hypothesize that the global transition/ambiguous range is sufficiently large to make the column CH2O/NO2 ratio unuseful for classifying near‐surface O3 sensitivity. Lastly, we present a case study from DISCOVER‐AQ‐Houston that suggests that O3 sensitivity on exceedance days may be substantially different than on nonexceedance days (which may be observable from space) and explore the diurnal evolution of O3 sensitivity, O3 production, and the column CH2O/NO2 ratio. The results of these studies suggest that although satellite measurements of CH2O/NO2 alone may not be sufficient for accurately classifying near‐surface O3 sensitivity, new techniques offered by geostationary platforms may nonetheless provide methods for using space‐based measurements to develop O3 mitigation strategies.
Spatial patterns of DOC concentration and DOM optical properties in a Brazilian tropical river‐wetland system
Authors: Dalmagro Higo J. , Johnson Mark S. , de Musis Carlo R. , Lathuillière Michael J. , Graesser Jordan , Pinto‐Júnior Osvaldo B. , Couto Eduardo G.
Published: July 2017

The Cerrado (savanna) and Pantanal (wetland) biomes of Central Western Brazil have experienced significant development activity in recent decades, including extensive land cover conversion from natural ecosystems to agriculture and urban expansion. The Cuiabá River transects the Cerrado biome prior to inundating large areas of the Pantanal, creating one of the largest biodiversity hot spots in the world. We measured dissolved organic carbon (DOC) and the optical absorbance and fluorescence properties of dissolved organic matter (DOM) from 40 sampling locations spanning Cerrado and Pantanal biomes during wet and dry seasons. In the upper, more agricultural region of the basin, DOC concentrations were highest in the rainy season with more aromatic and humified DOM. In contrast, DOC concentrations and DOM optical properties were more uniform for the more urbanized middle region of the basin between wet and dry seasons, as well as across sample locations. In the lower region of the basin, wet season connectivity between the river and the Pantanal floodplain led to high DOC concentrations, a fourfold increase in humification index (HIX) (an indicator of DOM humification), and a 50% reduction in the spectral slope (SR). Basin‐wide, wet season values forSR, HIX, and FI (fluorescence index) indicated an increasing representation of terrestrially derived DOM that was more humified. Parallel factor analysis identified two terrestrially derived components (C1 and C2) representing 77% of total fluorescing DOM (fDOM). A third, protein‐like fDOM component increased markedly during the wet season within the more urban‐impacted region.
2‐Iodoxybenzoic Acid Tosylates: the Alternative to Dess–Martin Periodinane Oxidizing Reagents
Authors: Yusubov Mekhman S. , Postnikov Pavel S. , Yusubova Roza Ya. , Yoshimura Akira , Jürjens Gerrit , Kirschning Andreas , Zhdankin Viktor V.
Published: July 2017

Two powerful hypervalent iodine(V) oxidants, DMP‐OTs (1‐tosyloxy‐1,1‐diacetoxy‐1H‐1λ5‐benzo[d][1,2]iodoxol‐3‐one) and IBX‐OTs (1‐tosyloxy‐1‐oxo‐1H‐1λ5‐benzo[d][1,2]iodoxol‐3‐one) show high reactivity in the oxidation of structurally complex primary and secondary alcohols, which are highly functionalized polyketide or terpene fragments or steroids. The yields of the corresponding carbonyl compounds are even higher for the protocol that uses pyridine as additive. The oxidations proceed very rapidly at room temperature leaving the protective groups and π‐systems intact and affording the corresponding carbonyl compounds in good to excellent yields. Moreover, IBX‐OTs is an efficient reagent for the oxidative dehydrogenation of steroidal alcohols to the corresponding enones.

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Carbon Nitride Aerogels for the Photoredox Conversion of Water
Authors: Ou Honghui , Yang Pengju , Lin Lihua , Anpo Masakazu , Wang Xinchen
Published: July 2017

Aerogel structures have attracted increasing research interest in energy storage and conversion owing to their unique structural features, and a variety of materials have been engineered into aerogels, including carbon‐based materials, metal oxides, linear polymers and even metal chalcogenides. However, manufacture of aerogels from nitride‐based materials, particularly the emerging light‐weight carbon nitride (CN) semiconductors is rarely reported. Here, we develop a facile method based on self‐assembly to produce self‐supported CN aerogels, without using any cross‐linking agents. The combination of large surface area, incorporated functional groups and three‐dimensional (3D) network structure, endows the resulting freestanding aerogels with high photocatalytic activity for hydrogen evolution and H2O2 production under visible light irradiation. This work presents a simple colloid chemistry strategy to construct 3D CN aerogel networks that shows great potential for solar‐to‐chemical energy conversion by artificial photosynthesis.
Generation of apoptosis‐resistant HEK293 cells with CRISPR/Cas mediated quadruple gene knockout for improved protein and virus production
Authors: Zhang Weifeng , Xiao Dan , Shan Linlin , Zhao Junli , Mao Qinwen , Xia Haibin
Published: July 2017

Apoptosis has important functions during pathophysiologic processes. However, from a biopharmaceutical point of view, active apoptosis of host cells is undesirable during viral packaging or protein expression, because it decreases the efficiency of viral or protein production. Here we used the CRISPR/Cas technique to knock out four pro‐apoptotic genes, Caspase3, Caspase6, Caspase7 and AIF1, in HEK293 cells, and successfully produced an apoptosis‐resistant cell line. Furthermore, this cell line showed higher expression levels of pro‐apoptotic proteins and higher packaging efficiency for the virus carrying these proteins than control HEK293 cells. This study not only produced an apoptosis‐resistant cell line that is useful in producing apoptosis‐inducing proteins or viruses expressing these proteins, but also provides a methodology to build other apoptosis‐resistant cell lines.
Enzyme‐Free Ligation of 5′‐Phosphorylated Oligodeoxynucleotides in a DNA Nanostructure
Authors: Kramer Markus , Richert Clemens
Published: July 2017

Multicomponent reactions are difficult synthetic transformations. For DNA, there is a special opportunity to align multiple strands in a folded nanostructure, so that they are preorganized to give a specific sequence. Multistrand reactions in DNA origami structures have previously been performed using photochemical crosslinking, 1,3‐diploar cycloadditions or phosphoramidate‐forming reactions. Here we report carbodiimide‐driven phosphodiester formation in a small origami sheet that produces DNA strands up to 600 nucleotides in length in a single step. The method uses otherwise unmodified oligodeoxynucleotides with a 5′‐terminal phosphate as starting materials. Compared to an enzymatic multistrand ligation involving linear duplexes, the carbodiimide‐driven ligation gave fewer side products, as detected by gel electrophoresis. The full‐length 600mer product was successfully amplified by polymerase chain reaction.
Confining Gold Nanoclusters in Highly Defective Graphitic Layers To Enhance the Methanol Electrooxidation Reaction
Authors: Mao Zhe , Hu Haihua , Su Rui , Liu Peizhi , Li Yixing , Zhang Wenting , Zhao Xiaoning , Guo Junjie , Guan Pengfei , Qin Gaowu , Zhang Xuefeng
Published: July 2017

The development of a highly efficient catalyst possessing both high activity and remarkable stability is a major focus in fuel‐cell applications. Herein, we utilized an arc‐discharge approach with an ultrafast cooling system to synthesize a core@shell structural Au@C nanocomposite comprising 3–5 nm gold clusters confined within highly defective graphitic layers. Such a construction not only improves the conductivity to accelerate the penetration of ions and electrons during the electrocatalytic process of methanol molecules, but it also suppresses chemical/thermal coarsening of the gold clusters. More importantly, the atomic‐scale Au/C interfaces contribute to a synergistic effect and enhance the activity relative to that of other gold‐based catalysts in the electrooxidation of methanol. This work highlights the role of heterogeneous interfaces in the catalytic efficiency of precious‐metal catalysts and rationalizes optimization in catalyst engineering.
Origin of enhanced VCD in amyloid fibril spectra: Effect of deuteriation and pH
Authors: Pazderková Markéta , Pazderka Tomáš , Shanmugasundaram Maruda , Dukor Rina K. , Lednev Igor K. , Nafie Laurence A.
Published: July 2017

Supramolecular chirality of amyloid fibrils, protein aggregates related to many neurodegenerative diseases, is a remarkable property associated with fibril structure and polymorphism. Since its discovery almost 10 years ago there is still little understanding of this phenomenon, including the cause of the highly enhanced vibrational circular dichroism (VCD) intensity arising from fibril supramolecular chirality. In this study, VCD spectra, enhanced by filament supramolecular chirality, are presented for lysozyme and insulin fibrils above and below pH 2 and after deuterium exchange, above and below pD 2. Supramolecular chirality (observed by VCD) and fibril morphology (documented by atomic force microscopy) are not affected by protein deuteriation. In D2O the fibril VCD sign pattern changes to fewer bands, with implications for the amide I/II origin of enhanced VCD intensity. Separation of amide I and II signals will facilitate calculations of enhanced VCD spectra of amyloid fibrils and enable a better understanding of the origin of the VCD sign pattern.
Reliable HPLC separation, vibrational circular dichroism spectra, and absolute configurations of isoborneol enantiomers
Authors: Gao Rui‐Qi , Fan Jun , Tan Qi , Guo Dong , Chen Tao , He Ru‐Jian , Li Dan , Zhang Hui , Zhang Wei‐Guang
Published: July 2017

Resolution of chiral compounds has played an important role in the pharmaceutical field, involving detailed studies of pharmacokinetics, physiological, toxicological, and metabolic activities of enantiomers. Herein, a reliable method by high‐performance liquid chromatography (HPLC) coupled with an optical rotation detector was developed to separate isoborneol enantiomers. A cellulose tris(3, 5‐dimethylphenylcarbamate)‐coated chiral stationary phase showed the best separation performance for isoborneol enantiomers in the normal phase among four polysaccharide chiral packings. The effects of alcoholic modifiers and column temperature were studied in detail. Resolution of the isoborneol racemate displayed a downward trend along with an increase in the content of ethanol and column temperature, indicating that less ethanol in the mobile phase and lower temperature were favorable to this process. Moreover, two isoborneol enantiomers were obtained via a semipreparative chiral HPLC technique under optimum conditions, and further characterized by analytical HPLC, and experimental and calculated vibrational circular dichroism (VCD) spectroscopy, respectively. The solution VCD spectrum of the first‐eluted component was consistent with the Density Functional Theory (DFT) calculated pattern based on the SSS configuration, indicating that this enantiomer should be (1S, 2S, 4S)‐(+)‐isoborneol. Briefly, these results have provided reliable information to establish a method for analysis, preparative separation, and absolute configuration of chiral compounds without typical chromophoric groups.
Cyclooxygenase Inhibition: Pain, Inflammation, and the Cardiovascular System
Authors: Grosser Tilo , Theken Katherine N. , FitzGerald Garret A.
Published: July 2017

Inhibitors of the cyclooxygenases (COXs), the nonsteroidal antiinflammatory drugs (NSAIDs), relieve inflammatory pain, but are associated with gastrointestinal and cardiovascular complications. Given the widespread use of NSAIDs, there has been a longstanding interest in optimizing their risk–benefit ratio, for example by reducing their gastrointestinal risk. More recently, the focus has shifted toward the cardiovascular complications of NSAIDs and very large prospective studies have been performed to compare cardiovascular risk across distinct NSAIDs. Surprisingly, much less attention has been paid to the efficacy side of the risk–benefit ratio. There is marked variability in the degree of pain relief by NSAIDs due to the complex interplay of molecular mechanisms contributing to the pain sensation, variability in the disposition of NSAIDs, and imprecision in the quantification of human pain. Here we discuss how NSAIDs relieve pain, how molecular mechanisms relate to clinical efficacy, and how this may inform our interpretation of clinical trials.
Insights from zebrafish on human pigment cell disease and treatment
Authors: Cooper Cynthia D.
Published: July 2017

Black pigment cells, melanocytes, arise early during development from multipotent neural crest cells. Melanocytes protect human skin from DNA damaging sunrays and provide color for hair, eyes, and skin. Several disorders and diseases originate from these cells, including the deadliest skin cell cancer, melanoma. Thus, melanocytes are critical for a healthy life and for protecting humans from disease. Due to the ease of visualizing pigment cells through transparent larvae skin and conserved roles for zebrafish melanophore genes to mammalian melanocyte genes, zebrafish larvae offer a biologically relevant model for understanding pigment cell development and disease in humans. This review discusses our current knowledge of melanophore biology and how zebrafish are contributing to improving how diseases of melanocytes are understood and treated in humans. Developmental Dynamics 246:889–896, 2017. © 2017 Wiley Periodicals, Inc.
Coevolution of competing Callosobruchus species does not stabilize coexistence
Authors: Hausch Stephen J. , Fox Jeremy W. , Vamosi Steven M.
Published: July 2017

Interspecific resource competition is expected to select for divergence in resource use, weakening interspecific relative to intraspecific competition, thus promoting stable coexistence. More broadly, because interspecific competition reduces fitness, any mechanism of interspecific competition should generate selection favoring traits that weaken interspecific competition. However, species also can adapt to competition by increasing their competitive ability, potentially destabilizing coexistence. We reared two species of bean beetles, the specialist Callosobruchus maculatus and the generalist C. chinensis, in allopatry and sympatry on a mixture of adzuki beans and lentils, and assayed mutual invasibility after four, eight, and twelve generations of evolution. Contrary to the expectation that coevolution of competitors will weaken interspecific competition, the rate of mutual invasibility did not differ between sympatry and allopatry. Rather, the invasion rate of C. chinensis, but not C. maculatus, increased with duration of evolution, as C. chinensis adapted to lentils without experiencing reduced adaptation to adzuki beans, and regardless of the presence or absence of C. maculatus. Our results highlight that evolutionary responses to interspecific competition promote stable coexistence only under specific conditions that can be difficult to produce in practice.
Critical assessment of the nanofiltration for reusing brackish effluent from an anaerobic membrane bioreactor
Authors: González E. , Ruigómez I. , Gómez J. , Marrero M.C. , Díaz F. , Delgado S. , Vera L.
Published: July 2017

In this study, a saline effluent from an anaerobic membrane bioreactor was treated by nanofiltration in order to allow its agricultural reuse. Short‐term tests were conducted to investigate membrane fouling and selective rejection of ions and emerging organic contaminants (EOCs). The study has been conducted with a negatively charged commercial thin‐film composite membrane (DK, GE Osmonics). The effect of operating pressure (5–20 bar) and cross‐flow velocity (0.12–0.37 m/s) on membrane performance have been researched. Dimensional analysis of steady permeate flux indicated that the gel layer or the polarization layer can be completely removed at critical cross‐flow velocity. At a sub‐critical velocity, membrane autopsies by scanning electron microscopy (SEM) and energy dispersive X‐Ray spectroscopy revealed a complex mixture of organic matter, phosphates and colloidal silica over the membranes surface. Since the rejection of monovalent cations (76–88%) was lower than that of multivalent cations (above 96%), the treated effluent was characterized by a very high levels of sodium adsorption ratio and ammonium. In addition, moderate rejection of low molecular weight EOCs (clofibric acid and caffeine) was observed. Therefore, the treated effluent did not achieve enough quality to be reused for agricultural irrigation. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 383–390, 2018
Mixture toxicity in the marine environment: Model development and evidence for synergism at environmental concentrations
Authors: Deruytter David , Baert Jan M. , Nevejan Nancy , De Schamphelaere Karel A.C. , Janssen Colin R.
Published: July 2017

Little is known about the effect of metal mixtures on marine organisms, especially after exposure to environmentally realistic concentrations. This information is, however, required to evaluate the need to include mixtures in future environmental risk assessment procedures. We assessed the effect of copper (Cu)–Nickel (Ni) binary mixtures on Mytilus edulis larval development using a full factorial design that included environmentally relevant metal concentrations and ratios. The reproducibility of the results was assessed by repeating this experiment 5 times. The observed mixture effects were compared with the effects predicted with the concentration addition model. Deviations from the concentration addition model were estimated using a Markov chain Monte-Carlo algorithm. This enabled the accurate estimation of the deviations and their uncertainty. The results demonstrated reproducibly that the type of interaction—synergism or antagonism—mainly depended on the Ni concentration. Antagonism was observed at high Ni concentrations, whereas synergism occurred at Ni concentrations as low as 4.9 μg Ni/L. This low (and realistic) Ni concentration was 1% of the median effective concentration (EC50) of Ni or 57% of the Ni predicted-no-effect concentration (PNEC) in the European Union environmental risk assessment. It is concluded that results from mixture studies should not be extrapolated to concentrations or ratios other than those investigated and that significant mixture interactions can occur at environmentally realistic concentrations. This should be accounted for in (marine) environmental risk assessment of metals. Environ Toxicol Chem 2017;36:3471–3479. © 2017 SETAC.