bluuebunny/crossref_metadata_2025 huggingface dataset:
Cryo-EM of dynein microtubule-binding domains shows how an axonemal dynein distorts the microtubule
Authors: Lacey Samuel E , He Shaoda , Scheres Sjors HW , Carter Andrew P
Published: July 2019

Dyneins are motor proteins responsible for transport in the cytoplasm and the beating of axonemes in cilia and flagella. They bind and release microtubules via a compact microtubule-binding domain (MTBD) at the end of a coiled-coil stalk. We address how cytoplasmic and axonemal dynein MTBDs bind microtubules at near atomic resolution. We decorated microtubules with MTBDs of cytoplasmic dynein-1 and axonemal dynein DNAH7 and determined their cryo-EM structures using helical Relion. The majority of the MTBD is rigid upon binding, with the transition to the high-affinity state controlled by the movement of a single helix at the MTBD interface. DNAH7 contains an 18-residue insertion, found in many axonemal dyneins, that contacts the adjacent protofilament. Unexpectedly, we observe that DNAH7, but not dynein-1, induces large distortions in the microtubule cross-sectional curvature. This raises the possibility that dynein coordination in axonemes is mediated via conformational changes in the microtubule.
Population demography of Oldham’s leaf turtle (Cyclemys oldhamii) in protected and disturbed habitats in Thailand
Authors: Seateun Sengvilay , Karraker Nancy E. , Stuart Bryan L. , Aowphol Anchalee
Published: July 2019

Background

Freshwater turtle populations are vulnerable to a range of human activities because of particular life history attributes, and anthropogenic impacts can cause shifts in demographic traits, including survival, density and population structure. Asian freshwater turtles have undergone dramatic population declines in recent decades principally because of collection for food, pet, and traditional medicine markets. Despite this, few studies have been conducted on the population demography of these turtles, thereby limiting our understanding of population trends and the development of conservation actions. Oldham’s leaf turtle (Cyclemys oldhamii) is one of the most commonly traded turtles in Asian markets, but previous published studies have focused solely on systematics.

Methods

We conducted a mark-recapture study of C. oldhamii at three sites in northeastern Thailand—a protected stream, a degraded stream, and human-constructed ponds—and evaluated differences in survival, density, population structure, and sexual dimorphism among sites.

Results

We captured 77 turtles at the protected stream, 67 at the constructed ponds, and two in the degraded stream. Survival was 12% lower and density was 35% lower in the constructed ponds than in the protected stream. Size class structure was skewed toward smaller individuals at the constructed ponds, and both sites exhibited subadult-skewed age class structure. Sex ratios were not statistically different than 1:1 at either site and did not differ between sites. We did not document sexual dimorphism in either population.

Discussion

Explanations for lower survival, lower densities, and skewed size class structure at the constructed ponds include collection for consumption or Buddhist prayer release locally, collection for illegal export from Thailand, predation by domestic dogs associated with humans living nearby, or lower habitat quality. Evidence from our study suggests that collection, either for local use or export, is the most likely explanation for differences in demographic characteristics between the two sites. The information gained from this study may contribute to a status assessment for C. oldhamii and development of conservation actions should they become necessary to protect populations in Thailand.
Parent-Adolescent Relationship in Context of Gender of Adolescents and Social Class of Families: A Case Study of GBPUAT, Uttarakhand
Authors: Kumari Arti , Singh Ritu , Mehra Manisha , Mishra Amit Kumar
Published: July 2019

The present study investigated gender differences in adolescents’ perceptions of parent-adolescent relationship among families (Class I, Class II, Class III, and Class IV) of G.B Pant University of Agriculture and Technology, Pantnagar, Uttarakhand across their gender. Families falling under social class I of the university had parent(s) working as Professor and Associate Professor in the university; those falling under social class II had parent(s) working as Assistant Professor or equivalent and Doctor in the university; those falling under social class III  had parent(s) working as Accountant, Supervisor, Lab Technician and Clerk in the university and those falling under social class IV had parent(s) working as Attendant, Driver, Peon, CRC laborer, Gardner and Sweeper. In the present study, forty adolescents were randomly selected from each social class of which 63 were girls and 97 boys making a total of 160 respondents. Respondents from each socio- economic class were split across gender to analyze difference in perception of their relationship with parents. Parent-child Relationship Scale (PCRS) by Dr Nalini Rao (1989) was administered with the adolescents. The present findings revealed interesting gender variations in parent–adolescent relationship across four social classes of families under study. Boys and girls both, from all the social classes reported no gender difference in their parents’ practice of symbolic punishment. On the contrary, in comparison to boys, girls from all the social classes of families reported their parents, mother and father both, to be significantly more protecting. Second striking observation was that boys and girls from social class I, II and III reported no gender based parental (mother and father) differential attitude on symbolic reward, loving, object reward, rejecting, object punishment, demanding, indifferent and neglecting domains of parent-adolescent relationship. However, girls from social class IV perceived their parents to be significantly more rejecting, indifferent and neglecting and mothers in particular to be more demanding and practicing object punishment. Whereas, boys from social class IV reported parents to be significantly more symbolically rewarding, loving and object rewarding and fathers in particular to be more demanding and practicing object punishment.
Isolation of Candida albicans among HIV Patients Presenting with Oral Thrush in Abuja, Nigeria
Authors: Thairu Yunusa, , Bob Ukonu, Agwu , Adeoye Aisha Mashood
Published: July 2019

Background: Candida infections are known contributors to the high morbidity and mortality rates seen in HIV positive patients.

Methodology: This was a descriptive cross-sectional study.  The study was carried out at the Microbiology research laboratory, department of Medical Microbiology, University of Abuja Teaching Hospital, Gwagwalada. The population is made up of two hundred and ten (210) patients who presented with oral thrush between fifteen years and seventy years which comprises of 160 HIV seropositive and 50 non age and sex matched HIV seronegative patients. Culture, Microscopy and ELISA methods were used for isolation of Candida albicans. An interviewer-administered, structured questionnaire was used as the study tool.

Results: The mean age for the isolation of Candida albicans was 30 ± 18.7 years, with the highest proportion of isolates within the age range of 21-30 years accounting for 27.1% of the study population recruited and the lowest proportion of isolates being 41-50 years accounting for 8.0%. From the 210 subjects with Candida albicans in the study, one hundred and sixty (160) representing 76.2 were isolated from HIV seropositive clients and Candida albicans isolation rate among HIV seronegative population was 23.8%.

Conclusion: The sensitivity, specificity and positive predictive value of using Grams reaction methods in the diagnosis of Candida albicans was 22.9%, 95.2% and 82.6%. The sensitivity, specificity and positive predictive value of using ELISA methods was 25.7%, 86.7% and 65.9%. In this study, there was preponderance of Candida albicans isolate among the young and the old in HIV seropositive patients but largely isolated from older patients among HIV seronegative  patients.
Glass Ceiling
Authors: Oxley Julinna
Published: July 2019

The term “glass ceiling” refers to the invisible barrier that prevents a qualified person from advancing into an organizational leadership position or attaining political office. The glass ceiling is an ethical issue because it may be the result of discrimination.
Assassination
Authors: Teson Fernando R.
Published: July 2019

Assassination is the extrajudicial intentional killing of an identified person for a political purpose. It is a troubling act and should be therefore presumptively prohibited. This entry tries to identify the conditions that could make assassination permissible in rare cases. First, the assassination would be needed to avert large losses of innocent lives. Second, the victim would have to be culpable. And, third, alternatives such as capture should not be available. The entry distinguishes between tyrannicide (assassination not sanctioned by the state) and targeted killing (assassination sanctioned by the state). Finally, the entry discusses various objections to assassination.
Executive Compensation
Authors: Donaldson Thomas
Published: July 2019

Criticisms of executive compensation, and especially CEO compensation, are rife. They rely on outsized ratios of executive compensation and ordinary employee compensation. Nonetheless, simple variance between executives and nonexecutives is insufficient to show unfairness. This article, in turn, considers moral arguments both for and against extremely high executive compensation. Arguments that defend high executive compensation often appeal to free market forces, the beneficial effects of which are said to necessitate unequal wealth distributions. Other arguments focus on the contributions that executive skills make to social welfare. After analyzing these and other arguments, the article identifies some of the more prominent proposals for firm‐initiated CEO compensation reform.
Siting
Authors: Hansson Sven Ove
Published: July 2019

Siting is the choice of a location for a human activity or construction. The object of siting can be some service facility or other positive resource for the neighborhood. Alternatively, it can be an activity with negative impact on the immediate environment, such as a landfill or a power plant. Most discussions of siting have focused on the latter category: that is, facilities that are perceived as negative by a large proportion of potential neighbors. There are two major classes of such facilities. In the first of these some
technology
is perceived to have negative local impact. Common examples are chemical industries, pipelines, nuclear power plants, wind farms, bioenergy plants, landfills, incinerators, railways, roads, and airports. The second class comprises facilities that bring in
people
whose presence is perceived as a threat. The siting of prisons, apartments for the mentally ill or retarded, rehabilitation centers for addicts, and housing for asylum seekers has often been met by local opposition.
Prudence
Authors: Bykvist Krister
Published: July 2019

To be prudent, in a general sense of the term, is to show foresight in your deliberations and take into account the effects your actions will have on the nonimmediate future. However, to be prudent is often understood, more narrowly, as being concerned with one's
own
future well‐being. Indeed, in the philosophical discussion it is often understood, more demandingly, as being concerned with one's own well‐being, without any intrinsic significance being attached to the
timing
of a certain benefit or harm in one's life, whether it be in the past, in the present, or in the future. This entry explores the question whether we have reason to be prudent in this more demanding sense.
Expert Testimony, Ethics of
Authors: Borenstein Jason , Henderson Carol
Published: July 2019

Experts can inform a variety of entities, including government committees and regulatory boards, and when they are undertaking that role, numerous ethical complexities can emerge. The focus of this entry will be to provide an overview of ethical issues related to when experts testify in legal proceedings, especially within the courtroom. A key issue is that experts can often have a conflict of interest between the duty to tell the truth and the desire to help a legal party win a case. Furthermore, it can be difficult to determine who is a genuine expert and which kinds of knowledge are within the scope of a given person's expertise. An overarching concern is the legal precedent that expert testimony may set and how that precedent may impact the public's well‐being.
Function Follows Form: Some Affinities Between Pure Icons, Hardcore Architecture and OOO
Authors: Deyong Sarah
Published: July 2019

Sarah Deyong, an associate professor and director of the architecture programme at the University of Nebraska–Lincoln, maps the complex relationships contemporary theorists and practitioners have with concepts of ‘form’, which can be traced back to previous avantgardes. She uses the work and publications of architectural collective WAI Think Tank as a microcosm of this complex discourse.
The Little Big Planet of Architectural Imagination: An Interview with NEMESTUDIO's Neyran Turan
Authors: Giamarelos Stylianos
Published: July 2019

Informed by the radical Italian groups of the 1960s and 1970s, NEMESTUDIO's work addresses all manner of urbanisms in our time of ‘Anthropocene’ geomorphology, global warming and the temporality of construction materials. Architect, historian and theorist Stylianos Giamarelos interviews the San‐Francisco‐based practice's co‐founder Neyran Turan to discover how the planetary scale of her thinking leads her back to the discipline of architecture and its history.
Play it Again: In Conversation with Architect Sam Jacob and Artist Pablo Bronstein
Authors: Butcher Matthew , Pearson Luke Caspar
Published: July 2019

Architecture and art are symbiotic disciplines. Architect Sam Jacob and artist Pablo Bronstein use tactics of performance, role play and enactment to both provoke and understand their individual practices. Robert Venturi and Aldo Rossi loom large as key influences in their expansive propositions. Guest‐Editors Matthew Butcher and Luke Caspar Pearson met with them in Bronstein's East London studio to discuss the meaning behind their use of historical architectural references within the development of their work.
Architecture Between the Panels: Comics, Cartoons and Graphic Narrative in the (New) Neo Avant‐Garde
Authors: Arana Luis Miguel Lus
Published: July 2019

Avant‐garde architects from the 1960s onwards drew numerous outside influences into the discipline, reshaping architecture's limits and communicative properties. Architect and researcher Luis Miguel Lus Arana, lecturer in History and Theory of Architecture at the University of Zaragoza in Spain, explores how comic books and cartoons were mobilised by groups such as Archigram, Ant Farm and Utopie to experiment with space and time. This discussion is accompanied by a specially commissioned comic by Lus Arana's alter ego, the cartoonist Klaus, charting this avant‐garde path from the experimental architecture of the mid‐20th century to the protagonists of today.
Application of Ti3C2 MXene Quantum Dots for Immunomodulation and Regenerative Medicine
Authors: Rafieerad Alireza , Yan Weiang , Sequiera Glen Lester , Sareen Niketa , Abu‐El‐Rub Ejlal , Moudgil Meenal , Dhingra Sanjiv
Published: July 2019

Inflammation is tightly linked to tissue injury. In regenerative medicine, immune activation plays a key role in rejection of transplanted stem cells and reduces the efficacy of stem cell therapies. Next‐generation smart biomaterials are reported to possess multiple biologic properties for tissue repair. Here, the first use of 0D titanium carbide (Ti3C2) MXene quantum dots (MQDs) for immunomodulation is presented with the goal of enhancing material‐based tissue repair after injury. MQDs possess intrinsic immunomodulatory properties and selectively reduce activation of human CD4+IFN‐γ+ T‐lymphocytes (control 87.1 ± 2.0%, MQDs 68.3 ± 5.4%) while promoting expansion of immunosuppressive CD4+CD25+FoxP3+ regulatory T‐cells (control 5.5 ± 0.7%, MQDs 8.5 ± 0.8%) in a stimulated lymphocyte population. Furthermore, MQDs are biocompatible with bone marrow‐derived mesenchymal stem cells and induced pluripotent stem cell‐derived fibroblasts. Finally, Ti3C2 MQDs are incorporated into a chitosan‐based hydrogel to create a 3D platform with enhanced physicochemical properties for stem cell delivery and tissue repair. This composite hydrogel demonstrates increased conductivity while maintaining injectability and thermosensitivity. These findings suggest that this new class of biomaterials may help bridge the translational gap in material and stem cell‐based therapies for tissue repair and treatment of inflammatory and degenerative diseases.
Scanning Tunneling Microscopy and Spectroscopy of Novel Silver–Containing DNA Molecules
Authors: Fardian‐Melamed Natalie , Eidelshtein Gennady , Rotem Dvir , Kotlyar Alexander , Porath Danny
Published: July 2019

The quest for a suitable molecule to pave the way to molecular nanoelectronics has been met with obstacles for over a decade. Candidate molecules such as carbon nanotubes lack the appealing trait of self‐assembly, while DNA seems to lack the desirable feature of conductivity. Silver‐containing poly(dG)–poly(dC) DNA (E‐DNA) molecules have recently been reported as promising candidates for molecular electronics, owing to the selectivity of their metallization, their thin and uniform structure, their resistance to deformation, and their maximum possible high conductivity. Ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) of E‐DNA presents an elaborate high‐resolution morphology characterization of these unique molecules, along with a detailed depiction of their electronic level structure. The energy levels found for E‐DNA indicate a novel truly hybrid metal–molecule structure, potentially more conductive than other DNA‐based alternatives.
Adlayer‐Free Large‐Area Single Crystal Graphene Grown on a Cu(111) Foil
Authors: Luo Da , Wang Meihui , Li Yunqing , Kim Changsik , Yu Ka Man , Kim Yohan , Han Huijun , Biswal Mandakini , Huang Ming , Kwon Youngwoo , Goo Min , Camacho‐Mojica Dulce C. , Shi Haofei , Yoo Won Jong , Altman Michael S. , Shin Hyung‐Joon , Ruoff Rodney S.
Published: July 2019

To date, thousands of publications have reported chemical vapor deposition growth of “single layer” graphene, but none of them has described truly single layer graphene over large area because a fraction of the area has adlayers. It is found that the amount of subsurface carbon (leading to additional nuclei) in Cu foils directly correlates with the extent of adlayer growth. Annealing in hydrogen gas atmosphere depletes the subsurface carbon in the Cu foil. Adlayer‐free single crystal and polycrystalline single layer graphene films are grown on Cu(111) and polycrystalline Cu foils containing no subsurface carbon, respectively. This single crystal graphene contains parallel, centimeter‐long ≈100 nm wide “folds,” separated by 20 to 50 µm, while folds (and wrinkles) are distributed quasi‐randomly in the polycrystalline graphene film. High‐performance field‐effect transistors are readily fabricated in the large regions between adjacent parallel folds in the adlayer‐free single crystal graphene film.
Toward Flexible Surface‐Enhanced Raman Scattering (SERS) Sensors for Point‐of‐Care Diagnostics
Authors: Xu Kaichen , Zhou Rui , Takei Kuniharu , Hong Minghui
Published: July 2019

Surface‐enhanced Raman scattering (SERS) spectroscopy provides a noninvasive and highly sensitive route for fingerprint and label‐free detection of a wide range of molecules. Recently, flexible SERS has attracted increasingly tremendous research interest due to its unique advantages compared to rigid substrate‐based SERS. Here, the latest advances in flexible substrate‐based SERS diagnostic devices are investigated in‐depth. First, the intriguing prospect of point‐of‐care diagnostics is briefly described, followed by an introduction to the cutting‐edge SERS technique. Then, the focus is moved from conventional rigid substrate‐based SERS to the emerging flexible SERS technique. The main part of this report highlights the recent three categories of flexible SERS substrates, including actively tunable SERS, swab‐sampling strategy, and the in situ SERS detection approach. Furthermore, other promising means of flexible SERS are also introduced. The flexible SERS substrates with low‐cost, batch‐fabrication, and easy‐to‐operate characteristics can be integrated into portable Raman spectroscopes for point‐of‐care diagnostics, which are conceivable to penetrate global markets and households as next‐generation wearable sensors in the near future.
Transparent Omniphobic Coating with Glass‐Like Wear Resistance and Polymer‐Like Bendability
Authors: Zhang Kaka , Huang Shuaishuai , Wang Jiandong , Liu Guojun
Published: July 2019

Transparent omniphobic or anti‐smudge coatings with glass‐like wear resistance and polymer‐like bendability have many potential applications but there are no reports of such materials. We Report herein a molecular composite possessing these properties. The composite is prepared via the photo‐initiated ring‐opening polymerization of the epoxide rings of glycidyloxypropyl polyhedral silsesquioxane (GPOSS). While the desired hardness is provided by the silica core, the flexibility is imparted by the glycidyloxypropyl network. Oil and water repellency is achieved without adversely affecting the other properties by incorporating a low‐surface‐tension liquid lubricant poly(dimethyl siloxane). On the final coating, various organic solvents and water readily and cleanly glide, while complex fluids, such as ink and paint facilely contract. These properties are retained after an initially flat coating sample is rolled into a U‐shape 500 times or is abraded with steel wool.
Emerging Bottom‐Up Strategies for the Synthesis of Graphene Nanoribbons and Related Structures
Authors: Jolly Anthony , Miao Dandan , Daigle Maxime , Morin Jean‐François
Published: July 2019

The solution‐phase synthesis is one of the most promising strategies for the preparation of well‐defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect‐free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd‐ and Ni‐catalyzed reactions.
Anti‐Stokes Stress Sensing: Mechanochemical Activation of Triplet–Triplet Annihilation Photon Upconversion
Authors: Yildiz Deniz , Baumann Christoph , Mikosch Annabel , Kuehne Alexander J. C. , Herrmann Andreas , Göstl Robert
Published: July 2019

The development of methods to detect damage in macromolecular materials is of paramount importance to understand their mechanical failure and the structure–property relationships of polymers. Mechanofluorophores are useful and sensitive molecular motifs for this purpose. However, to date, tailoring of their optical properties remains challenging and correlating emission intensity to force induced material damage and the respective events on the molecular level is complicated by intrinsic limitations of fluorescence and its detection techniques. Now, this is tackled by developing the first stress‐sensing motif that relies on photon upconversion. By combining the Diels–Alder adduct of a π‐extended anthracene with the porphyrin‐based triplet sensitizer PtOEP in polymers, triplet–triplet annihilation photon upconversion of green to blue light is mechanochemically activated in solution as well as in the solid state.
Enhanced sulfur‐resistant methanation performance over MoO3–ZrO2 catalyst prepared by solution combustion method
Authors: Ullah Niamat , Qu Jianglei , Li Zhenhua
Published: July 2019

Sulfur‐resistant methanation of syngas was studied over MoO3–ZrO2 catalysts at 400°C. The MoO3–ZrO2 solid‐solution catalysts were prepared using the solution combustion method by varying MoO3 content and temperature. The 15MoO3–ZrO2 catalyst achieved the highest methanation performance with CO conversion up to 80% at 400°C. The structure of ZrO2 and dispersed MoO3 species was characterized using X‐ray diffraction and transmission electron microscopy. The energy‐dispersive spectrum of the 15MoO3–ZrO2 catalyst showed that the solution combustion method gave well‐dispersed MoO3 particles on the surface of ZrO2. The structure of the catalysts depends on the Mo surface density. It was observed that in the 15MoO3–ZrO2 catalyst the Mo surface density of 4.2 Mo atoms nm−2 approaches the theoretical monolayer capacity of 5 Mo atoms nm−2. The addition of a small amount of MoO3 to ZrO2 led to higher tetragonal content of ZrO2 along with a reduction of particle size. This leads to an efficient catalyst for the low‐temperature CO methanation process.
Photophysical and Electrochemical Studies of Anchored Chromium (III) Complex on Reduced Graphene Oxide via Diazonium Chemistry
Authors: Jose Jemini , Rajamani Athimotlu Raju , Anandaram Sreekanth , Jose Sujin P. , Peter Sebastian C. , P B Sreeja
Published: July 2019

Covalently anchored chromium complex on reduced graphene oxide (rGO‐Cr) is successfully synthesised through trimethoxy silyl propanamine (TMSPA) and phenyl azo salicylaldehyde (PAS) coupling. The rGO‐Cr is characterised by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), electron dispersive analysis of X‐rays (EDAX), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Absorption and emission properties of rGO‐TMSPA‐PAS are studied by excitation dependent photoluminescence emissions at room temperature. Electrochemical sensing activity of rGO‐Cr is monitored for paracetamol using modified glassy carbon electrode. Cyclic voltammetry measurements indicated that rGO‐Cr substantially enhance the eletrochemical response of paracetamol. The experimental factors are investigated and optimized.
Joint Modeling of Characters, Words, and Conversation Contexts for Microblog Keyphrase Extraction
Authors: Zhang Yingyi , Zhang Chengzhi , Li Jing
Published: July 2019

Millions of messages are produced on microblog platforms every day, leading to the pressing need for automatic identification of key points from the massive texts. To absorb salient content from the vast bulk of microblog posts, this article focuses on the task of microblog keyphrase extraction. In previous work, most efforts treat messages as independent documents and might suffer from the data sparsity problem exhibited in short and informal microblog posts. On the contrary, we propose to enrich contexts via exploiting conversations initialized by target posts and formed by their replies, which are generally centered around relevant topics to the target posts and therefore helpful for keyphrase identification. Concretely, we present a neural keyphrase extraction framework, which has 2 modules: a conversation context encoder and a keyphrase tagger. The conversation context encoder captures indicative representation from their conversation contexts and feeds the representation into the keyphrase tagger, and the keyphrase tagger extracts salient words from target posts. The 2 modules were trained jointly to optimize the conversation context encoding and keyphrase extraction processes. In the conversation context encoder, we leverage hierarchical structures to capture the word‐level indicative representation and message‐level indicative representation hierarchically. In both of the modules, we apply character‐level representations, which enables the model to explore morphological features and deal with the out‐of‐vocabulary problem caused by the informal language style of microblog messages. Extensive comparison results on real‐life data sets indicate that our model outperforms state‐of‐the‐art models from previous studies.
Control of large scale interconnected systems with input and state delays using decentralized adaptive state observers
Authors: Hashemipour Seyed Hamid , Vasegh Nastaran , Khaki Sedigh Ali
Published: July 2019

This paper investigates the problem of decentralized model reference adaptive control (MRAC) for a class of large scale interconnected systems with both state and input delays. The upper bounds of the interconnection terms are considered to be unknown. Time varying delays in the nonlinear interconnection terms are bounded and nonnegative continuous functions and their derivatives are not necessarily less than one. For exact prediction, a decentralized adaptive state observer is designed and a nested predictor based approach is established to predict the future states of the input delay compensation. It is shown that the solutions of uncertain large‐scale time‐delay interconnected systems converge uniformly exponentially to a desired small ball. The effectiveness of the proposed approaches is illustrated by two examples.
Scenedesmus obliquusmicroalga‐based biorefinery – from brewery effluent to bioactive compounds, biofuels and biofertilizers – aiming at a circular bioeconomy
Authors: Ferreira Alice , Ribeiro Belina , Ferreira Ana F. , Tavares Marileide L. A. , Vladic Jelena , Vidović Senka , Cvetkovic Dragoljub , Melkonyan Lusine , Avetisova Gayane , Goginyan Vigen , Gouveia Luísa
Published: July 2019

The circular bioeconomy concept relies on the exploitation of wastes as a feedstock of different biotechnological processes to obtain, as much as possible, a huge spectrum of biochemical components through a biorefinery platform. This work deals with the treatment of brewery effluent through the cultivation ofScenedesmus obliquusmicroalga and the use of the biomass in a complex biorefinery. The treatment proved efficient in the removal of nutrients (N, P and COD removals of 88, 30 and 71% respectively). Several compounds and products were obtained from the biomass, such as: (a) phenols (0.249–1.016 mg GAE mL−1) and flavonoids (0.05–0.167 mg CE mL−1) by subcritical water extraction (SWE) at 120 °C, the extraction efficiency being five times higher at 200 °C; (b) biohydrogen by dark fermentation (67.1 mL H2gVS−1); (c) bio‐oil (64%), biochar (30%) and biogas (6%) by pyrolysis; and (d) enhanced capacity of germination/growth of wheat and barley seeds byS. obliquusculture and biomass (pellet, after centrifugation); better results were obtained with the biomass cultivated in brewery effluent (when compared with synthetic medium), and the biomass pellet was better than the whole culture; barley seeds treated with the pellet from the brewery effluent had the highest germination index (GI) of 85 compared with the control (tap water) GI of 35. The innovative study emphasis was on reducing microalgae production costs, providing environmental benefits in a biorefinery‐basedS. obliquusplatform. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Chromatin Architecture in the Fly: Living without CTCF/Cohesin Loop Extrusion?
Authors: Matthews Nicholas E. , White Rob
Published: July 2019

The organization of the genome into topologically associated domains (TADs) appears to be a fundamental process occurring across a wide range of eukaryote organisms, and it likely plays an important role in providing an architectural foundation for gene regulation. Initial studies emphasized the remarkable parallels between TAD organization in organisms as diverse as Drosophila and mammals. However, whereas CCCTC‐binding factor (CTCF)/cohesin loop extrusion is emerging as a key mechanism for the formation of mammalian topological domains, the genome organization in Drosophila appears to depend primarily on the partitioning of chromatin state domains. Recent work suggesting a fundamental conserved role of chromatin state in building domain architecture is discussed and insights into genome organization from recent studies in Drosophila are considered.
Power gains by using external information in clinical trials are typically not possible when requiring strict type I error control
Authors: Kopp‐Schneider Annette , Calderazzo Silvia , Wiesenfarth Manuel
Published: July 2019

In the era of precision medicine, novel designs are developed to deal with flexible clinical trials that incorporate many treatment strategies for multiple diseases in one trial setting. This situation often leads to small sample sizes in disease‐treatment combinations and has fostered the discussion about the benefits of borrowing of external or historical information for decision‐making in these trials. Several methods have been proposed that dynamically discount the amount of information borrowed from historical data based on the conformity between historical and current data. Specifically, Bayesian methods have been recommended and numerous investigations have been performed to characterize the properties of the various borrowing mechanisms with respect to the gain to be expected in the trials. However, there is common understanding that the risk of type I error inflation exists when information is borrowed and many simulation studies are carried out to quantify this effect. To add transparency to the debate, we show that if prior information is conditioned upon and a uniformly most powerful test exists, strict control of type I error implies that no power gain is possible under any mechanism of incorporation of prior information, including dynamic borrowing. The basis of the argument is to consider the test decision function as a function of the current data even when external information is included. We exemplify this finding in the case of a pediatric arm appended to an adult trial and dichotomous outcome for various methods of dynamic borrowing from adult information to the pediatric arm. In conclusion, if use of relevant external data is desired, the requirement of strict type I error control has to be replaced by more appropriate metrics.
Efficient Generation of Hydrazides in Proteins by RadA Split Intein
Authors: Liu Jun , Ekanayake Oshini , Santoleri Dominic , Walker Kelsi , Rozovsky Sharon
Published: July 2019

Protein C‐terminal hydrazides are useful for bioconjugation and construction of proteins from multiple fragments through native chemical ligation. To generate C‐terminal hydrazides in proteins, an efficient intein‐based preparation method has been developed by using thiols and hydrazine to accelerate the formation of the transient thioester intermediate and subsequent hydrazinolysis. This approach not only increases the yield, but also improves biocompatibility. The scope of the method has been expanded by employing Pyrococcus horikoshii RadA split intein, which can accommodate a broad range of extein residues before the site of cleavage. The use of split RadA minimizes premature intein N cleavage in vivo and offers control over the initiation of the intein N cleavage reaction. It is expected that this versatile preparation method will expand the utilization of protein C‐terminal hydrazides in protein preparation and modification.
Structure‐Guided Tuning of a Selectivity Switch towards Ribonucleosides in Trypanosoma brucei Purine Nucleoside 2′‐Deoxyribosyltransferase
Authors: Del Arco Jon , Mills Alberto , Gago Federico , Fernández‐Lucas Jesús
Published: July 2019

The use of nucleoside 2′‐deoxyribosyltransferases (NDTs) as biocatalysts for the industrial synthesis of nucleoside analogues is often hindered by their strict preference for 2′‐deoxyribonucleosides. It is shown herein that a highly versatile purine NDT from Trypanosoma brucei (TbPDT) can also accept ribonucleosides as substrates; this is most likely because of the distinct role played by Asn53 at a position that is usually occupied by Asp in other NDTs. Moreover, this unusual activity was improved about threefold by introducing a single amino acid replacement at position 5, following a structure‐guided approach. Biophysical and biochemical characterization revealed that the TbPDTY5F variant is a homodimer that displays maximum activity at 50 °C and pH 6.5 and shows a remarkably high melting temperature of 69 °C. Substrate specificity studies demonstrate that 6‐oxopurine ribonucleosides are the best donors (inosine>guanosine≫adenosine), whereas no significant preferences exist between 6‐aminopurines and 6‐oxopurines as base acceptors. In contrast, no transferase activity could be detected on xanthine and 7‐deazapurines. TbPDTY5F was successfully employed in the synthesis of a wide range of modified ribonucleosides containing different purine analogues.
Synergistic Effect of Covalent Bonding and Physical Encapsulation of Sulfur in the Pores of a Microporous COF to Improve Cycling Performance in Li‐S Batteries
Authors: Royuela Sergio , Almarza Joaquín , Mancheño María J. , Pérez‐Flores Juan C. , Michel Enrique G. , Ramos María M. , Zamora Félix , Ocón Pilar , Segura José L.
Published: July 2019

Lithium‐sulfur batteries stands out as a promising technology for energy storage owing to a combination of favorable characteristics including a high theoretical gravimetric capacity, energy density, inexpensive character, and environmental benignity. Covalent organic frameworks (COFs) are a rapidly developing family of functional nanostructures which combine porosity and crystallinity, and which have been already used in these kinds of batteries to build sulfur electrodes, by embedding sulfur into porous COFs in order to enhance cycle lifetimes. In this contribution, this is taken one step forward and a COF endowed with vinyl groups is used, in order to graft sulfur to the COF skeleton through inverse vulcanization. The main aim of the article is to show the synergistic effect of covalent bonding and physical encapsulation of sulfur in the pores of the COF in order to alleviate the fatal redox shuttling process, to improve the cycling performance, and to provide faster ion diffusion pathways. In addition, it is shown how the material with covalently‐bound S provides better electrochemical performance under demanding and/or changeable charge conditions than a parent analogue material with sulfur physically confined, but without covalent linkage.
Probing 2H‐Indazoles as Templates for SGK1, Tie2, and SRC Kinase Inhibitors
Authors: Schoene Jens , Gazzi Thais , Lindemann Peter , Christmann Mathias , Volkamer Andrea , Nazaré Marc
Published: July 2019

The broader and systematic application of a novel scaffold is often hampered by the unavailability of a short and reliable synthetic access. We investigated a new strategy for the design and synthesis of an array of N2‐substituted aza‐2H‐indazole derivatives as potential kinase inhibitors. Guided by a rational ligand alignment approach to qualify the so‐far underrepresented aza‐2H‐indazole scaffold, indazoles were connected at the N2 position with a phenyl spacer and an arylsulfonamide or amide linkage. Initial profiling against a panel of 30 kinases confirmed the in silico predicted selectivity bias. A synthesized focused library of 52 different aza‐2H‐indazole derivatives showed good initial selective inhibition against SGK1, Tie2, and SRC kinases, with the best representatives having IC50 values in the range of 500 nm. In a comparative computational study, these data were analyzed and rationalized in light of docking studies.
Nonuniqueness of Weak Solutions to the SQG Equation
Authors: Buckmaster Tristan , Shkoller Steve , Vicol Vlad
Published: July 2019

We prove that weak solutions of the inviscid SQG equations are not unique, thereby answering Open Problem 11 of De Lellis and Székelyhidi in 2012. Moreover, we also show that weak solutions of the dissipative SQG equation are not unique, even if the fractional dissipation is stronger than the square root of the Laplacian. In view of the results of Marchand in 2008, we establish that for the dissipative SQG equation, weak solutions may be constructed in the same function space both via classical weak compactness arguments and via convex integration. © 2019 Wiley Periodicals, Inc.
A new replica placement mechanism for mobile media streaming in edge computing
Authors: Tang Yayuan , Wang Hao , Guo Kehua , Luo Tao , Chi Tao
Published: July 2019

With the advent of the Internet of things era, cloud computing platforms will face the challenges of massive equipment requirements for access, massive data, insufficient bandwidth, and high power consumption. Edge computing, as a new technology, makes it possible to stream media over the edge network. However, many problems related to file sharing among edge nodes and to the files provided by cloud servers exist. We propose a novel replica placement strategy for mobile media streaming in edge computing (RPME) to address the aforementioned problem. First, we introduce a multilevel replica placement model in the RPME. In the RPME, we acquire the user information and the user‐item rating matrix when the user requests the media data. At the server, we cluster the users according the user information, update the user‐item rating matrix, and then generate a replica recommendation sequence. For when the server submits the replica recommendation sequence to the edge node considering the constraints of the edge node storage capacity and the limitations on the service capacity of the requested replica, we propose an effective replica placement mechanism in the RPME. To show the benefits of the RPME, we also present several experiments to prove its validity.
Kinetic Control over Morphology of Nanoporous Graphene on Surface
Authors: Huang Jianmin , Jia Hongxing , Wang Tao , Feng Lin , Du Pingwu , Zhu Junfa
Published: July 2019

On‐surface synthesis of high‐quality nanoporous graphene (NPG) for application in nanotechnology and nanodevices remains challenging. Rational design of molecular precursors and proper kinetic control over the reaction process are the two key factors to tune the synthesis. Herein, we report a detailed study of the coupling reactions of a planar halogen‐substituted nanographene molecular precursor, hexaiodo‐peri‐hexabenzocoronene (I6‐HBC), on the Au(111) surface in the synthesis of NPG. The influence of three basic kinetic processes – molecular adsorption, migration, and coupling – on the synthesis was investigated. The results show that the HBC molecules deposited at low temperature predominantly desorb from the Au(111) surface during the annealing process, whereas depositing the precursor molecules onto a hot surface (700 K) can lead to the formation of NPG. However, at such a high surface temperature, simultaneous intermolecular dehydrogenative coupling between HBC monomers can hinder the ordered growth of NPG through Ullmann coupling. Moreover, the deposition rate of the precursors greatly influences the growth morphology of the NPG nanostructures.
Design of Multi‐Metallic‐Based Electrocatalysts for Enhanced Water Oxidation
Authors: Bo Xin , Dastafkan Kamran , Zhao Chuan
Published: July 2019

Electrochemical water splitting by renewable energy resources is an efficient and green approach for hydrogen gas production. However, the anodic oxygen evolution reaction (OER) largely impedes the industrial application due to its sluggish four‐electron‐transition kinetics. Although various materials have been developed to accelerate the OER rate, still some issues should be addressed to meet the industrial demand: (i) considerable 200–300 mV overpotential as extra onset energy input, (ii) limited survival and performance in acidic electrolyte for the majority of oxide/hydroxide composite materials, (iii) unsatisfying long‐term durability and (iv) the need for facile and scalable preparation methods. Here, we emphasize on multi‐metallic composites with enhanced OER activity based on both precious and nonprecious elements that outperform the unary and binary composites. The regulation effect from multi‐metal incorporation is also summarized systematically: (i) introducing foreign metal atoms to the host material boosts the physical properties such as conductivity, surface area, defect density, morphology, wettability, etc., (ii) metal doping can synergistically regulate the electronic features of the host material, e. g. oxygen vacancy, eg orbit filling, coordinative number and covalence state, which can optimize the absorption/desorption energy of the M−O intermediate, (iii) chaotic impact from the added atoms twists the catalyst lattice into a more aggressive and higher energy state, which is more feasible to transform to an active intermediate with lower required energy supply. This review aims to provide a practical approach to further improve the OER performance via multi‐metallic‐based catalysts.
Stereoselective Alkyne Hydrogenation by using a Simple Iron Catalyst
Authors: Gregori Bernhard J. , Schwarzhuber Felix , Pöllath Simon , Zweck Josef , Fritsch Lorena , Schoch Roland , Bauer Matthias , Jacobi von Wangelin Axel
Published: July 2019

The stereoselective hydrogenation of alkynes constitutes one of the key approaches for the construction of stereodefined alkenes. The majority of conventional methods utilize noble and toxic metal catalysts. This study concerns a simple catalyst comprised of the commercial chemicals iron(II) acetylacetonate and diisobutylaluminum hydride, which enables the Z‐selective semihydrogenation of alkynes under near ambient conditions (1–3 bar H2, 30 °C, 5 mol % [Fe]). Neither an elaborate catalyst preparation nor addition of ligands is required. Mechanistic studies (kinetic poisoning, X‐ray absorption spectroscopy, TEM) strongly indicate the operation of small iron clusters and particle catalysts.
Ultralow power voltage reference circuit for implantable devices in standard CMOS technology
Authors: Pereira‐Rial Óscar , López Paula , Carrillo Juan M. , Brea Víctor M. , Cabello Diego
Published: July 2019

An ultralow power CMOS voltage reference for body implantable devices is presented in this paper. The circuit core consists of only regular threshold voltage PMOS transistors, thus leading to a very reduced output voltage dispersion, defined as σ/μ, and extremely low power consumption. A mathematical model of the generated reference voltage was obtained by solving circuit equations, and its numerical solution has been validated by extensive electrical simulations using a commercial circuit simulator. The proposed solution incorporates a passive RC low‐pass filter, to enhance power supply rejection (PSR) over a wide frequency range, and a speed‐up section, to accelerate the switching‐on of the circuit. The prototype was implemented in 0.18 μm standard CMOS technology and is able to operate with supply voltages ranging from 0.7 to 1.8 V providing a measured output voltage value of 584.2 mV at the target temperature of 36° C. The measured σ/μ dispersion of the reference voltage generated is 0.65% without the need of trimming. At the minimum supply of 0.7 V, the experimental power consumption is 64.5 pW, while the measured PSR is kept below –60 dB from DC up to the MHz frequency range.