bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensino Baseado em Casos Aliado à Aprendizagem Online em Disciplina de Comunicação Científica
Authors: Cabral Patrícia Fernanda de Oliveira , Souza Nilcimar Dos Santos , Queiroz Salete Linhares
Published: October 2017

Ways of organization of learning activities based on Computer-Supported Collaborative Learning have been discussed since the beginning of the 80s. With that in mind, educators should be encouraged to use computers in innovative ways to help students gain experience in collaboration and develop critical thinking and argument skills. This paper addresses a didactic activity based on computer-supported collaborative learning principles. We investigate the dynamics of interactions among undergraduate chemistry students within the groups focusing on skills of active learning conversation described in the Collaborative Learning Model. In a virtual learning environment named eduqui.info 37 students divided into 17 doubles and 1 trio solved 4 investigative case studies related to environmental pollution caused by plastic and oil, replacement of aviation gasoline by ethanol and replacement of trans fat found in foods. The messages posted on eduqui.info Forum by 2 doubles were analyzed for the identification of the students’ collaboration. The major sub-skills related to Collaborative Learning Model found in the students’ messages were Inform, Argue and Request. It is possible to conclude that activities like the one addressed in this study can be effectively used to develop critical thinking and argument skills in undergraduate chemistry students.
Estrutura Ontológica para representar Papéis Colaborativos Afetivos em ambientes CSCL
Authors: Reis Rachel Carlos Duque , Rodriguez Carla Lopes , Lyra Kamila Takayama , Isotani Seiji
Published: October 2017

The use of ontologies to represent CSCL scenarios have been investigated by several researchers in the literature. Despite of important contributions of such works, we have observed the lack of studies that consider the aspects related to students’ affect (e.g., personality trait) to represent such scenarios. Thus, this paper aims at extending the ontological structure of Affective Collaborative Learning (ACL) role to represent the relation between Stable/Unstable Extroverted personality traits and Full Participant role defined by the Distributed Cognition learning theory. Based on such ontological structure we create three CSCL scenarios to deal with lack of students’ reflection. In order to evaluate the impact of low and high impulsivity characteristics on such scenarios, we developed a case study with children aged between 09-10 to verify three alternative hypotheses. The results indicate that low impulsivity in homogeneous groups, where students performed the ACL role Extroverted Stable Full Participant, does not influence the group performance. Based on such ontological structure we hope to contribute with solutions to create more effective and personalized CSCL scenarios.
David J. Wertheim, Ed. The Jew as Legitimation: Jewish-Gentile Relations Beyond Antisemitism and Philosemitism
Authors: Levy Richard S.
Published: October 2017

No abstract is available.
Two single-point mutations shift the ligand selectivity of a pheromone receptor between two closely related moth species
Authors: Yang Ke , Huang Ling-Qiao , Ning Chao , Wang Chen-Zhu
Published: October 2017

Male moths possess highly sensitive and selective olfactory systems that detect sex pheromones produced by their females. Pheromone receptors (PRs) play a key role in this process. The PR HassOr14b is found to be tuned to (Z)−9-hexadecenal, the major sex-pheromone component, in Helicoverpa assulta. HassOr14b is co-localized with HassOr6 or HassOr16 in two olfactory sensory neurons within the same sensilla. As HarmOr14b, the ortholog of HassOr14b in the closely related species Helicoverpa armigera, is tuned to another chemical (Z)−9-tetradecenal, we study the amino acid residues that determine their ligand selectivity. Two amino acids located in the transmembrane domains F232I and T355I together determine the functional difference between the two orthologs. We conclude that species-specific changes in the tuning specificity of the PRs in the two Helicoverpa moth species could be achieved with just a few amino acid substitutions, which provides new insights into the evolution of closely related moth species.
Maturation and fertilization in vitro of Pteria sterna (Gould, 1851, Mollusca)
Authors: Harris C , Fierro S , De-La-Cerda A , Domínguez D , Echanove JJ , Fierro I , Garay K , García B , González JC , Lara R , López AC , Martínez J , Montalvo M , Nieto R , Oceguera A , Orozco C , Sánchez G , Torres AL , Varela S , Vital V , Zavala JO , Gould MC
Published: October 2017

P. sterna oocytes cannot be fertilized in vitro unless they are obtained by inducing spawning. The present work was undertaken to develop a simple method to induce germinal vesicle breakdown that would enable the oocytes to be fertilized without prior spawning. We found that Pteria sterna oocytes removed from the ovaries are induced to undergo germinal vesicle breakdown (GVBD) by 10 mM NH4Cl in seawater, and proceed to metaphase I of meiosis, at which stage they can be fertilized and will develop at least as far as "D" larvae. On the other hand, ovarian oocytes exposed to 2 × 10–5 M serotonin in seawater remained in prophase and did not undergo GVBD. Ammonium chloride treatment provides a simple, inexpensive procedure that can be useful in studies of fertilization and development, and for attempts to repopulate this exploited species.
Paleointensity From Subaerial Basaltic Glasses From the Second Hawaii Scientific Drilling Project (HSDP2) Core and Implications for Possible Bias in Data From Lava Flow Interiors
Authors: Cai S. , Tauxe L. , Cromwell G.
Published: October 2017

In this study, we collected samples from subaerial basaltic glassy margins from the second Hawaii Scientific Drilling Project (HSDP2) core. We employed the rigorous “IZZI” method during the paleointensity experiment combined with the stringent “CCRIT” criteria for data selection to obtain 21 robust paleointensity estimates recorded by glassy margins from 20 lava flows. We compared our new results to published paleointensities from the interiors of the lava flows from HSDP2 and found that our data are systematically lower than those from the interiors of the same lava flows. The reasons for the discrepancy in intensity are still unclear, but one possibility that could not be absolutely excluded is the effect of cooling rate on the more slowly cooled lava flow interiors. Although our new data from the glassy margins are lower than those from the lava flow interiors, they are still overall higher than the expected field of the study site calculated from a geocentric axial dipole model with an ancient average field of 42 ZAm2, either because of a long‐term local anomaly of the field in Hawaii or an insufficient age distribution of our new data (e.g., missing the time period with low field intensities).
Biogeochemical Impact of Snow Cover and Cyclonic Intrusions on the Winter Weddell Sea Ice Pack
Authors: Tison J.‐L. , Schwegmann S. , Dieckmann G. , Rintala J.‐M. , Meyer H. , Moreau S. , Vancoppenolle M. , Nomura D. , Engberg S. , Blomster L. J. , Hendricks S. , Uhlig C. , Luhtanen A.‐M. , de Jong J. , Janssens J. , Carnat G. , Zhou J. , Delille B.
Published: October 2017

Sea ice is a dynamic biogeochemical reactor and a double interface actively interacting with both the atmosphere and the ocean. However, proper understanding of its annual impact on exchanges, and therefore potentially on the climate, notably suffer from the paucity of autumnal and winter data sets. Here we present the results of physical and biogeochemical investigations on winter Antarctic pack ice in the Weddell Sea (R. V. Polarstern AWECS cruise, June–August 2013) which are compared with those from two similar studies conducted in the area in 1986 and 1992. The winter 2013 was characterized by a warm sea ice cover due to the combined effects of deep snow and frequent warm cyclones events penetrating southward from the open Southern Ocean. These conditions were favorable to high ice permeability and cyclic events of brine movements within the sea ice cover (brine tubes), favoring relatively high chlorophyll‐a (Chl‐a) concentrations. We discuss the timing of this algal activity showing that arguments can be presented in favor of continued activity during the winter due to the specific physical conditions. Large‐scale sea ice model simulations also suggest a context of increasingly deep snow, warm ice, and large brine fractions across the three observational years, despite the fact that the model is forced with a snowfall climatology. This lends support to the claim that more severe Antarctic sea ice conditions, characterized by a longer ice season, thicker, and more concentrated ice are sufficient to increase the snow depth and, somehow counterintuitively, to warm the ice.
Novel Ω‐Shaped Core–Shell Photodetector with High Ultraviolet Selectivity and Enhanced Responsivity
Authors: Hu Mingxiang , Teng Feng , Chen Hongyu , Jiang Mingming , Gu Yuzhu , Lu Hongliang , Hu Linfeng , Fang Xiaosheng
Published: October 2017

The design of nanostructure plays an important role in performance enhancement of low‐dimensional optoelectronic devices. Herein, a novel photodetector (PD) based on electrospun SnO2 nanofibers with Ω‐shaped ZnO shell (SnO2@ZnO) is fabricated. With 87.4% transmittance at 550 nm, SnO2@ZnO PD exhibits a high photo‐to‐dark current ratio up to 104 at around 280 nm. Owing to the additional Ω‐shaped ZnO shell, SnO2@ZnO PD possesses a responsivity of nearly 100 A W−1 under 5 V bias and the illumination of 250 nm light, which is 30‐time enhancement of pristine SnO2 PD. The enhancement is mainly attributed to type‐II energy band structure. Furthermore, by changing the direction of incident light, SnO2@ZnO PD has a high UV selectivity with an UV–vis rejection ratio (R250 nm/R400 nm) as much as 2.0 × 103 at 5 V bias under back illumination, which is fourfold higher than that under face illumination. The UV selectivity improvement may be attributed to light confinement in the Ω‐shaped structure. With both theoretical simulations and experimental comparisons, it is demonstrated that the unique compact Ω‐shaped nanostructure does contribute to photon trapping and gaining process, especially in back‐illumination configuration. The approach can be easily extended to other materials, preparing novel building blocks for optoelectronic devices.
Scaffold‐Based microRNA Therapies in Regenerative Medicine and Cancer
Authors: Curtin Caroline M. , Castaño Irene Mencía , O'Brien Fergal J.
Published: October 2017

microRNA‐based therapies are an advantageous strategy with applications in both regenerative medicine (RM) and cancer treatments. microRNAs (miRNAs) are an evolutionary conserved class of small RNA molecules that modulate up to one third of the human nonprotein coding genome. Thus, synthetic miRNA activators and inhibitors hold immense potential to finely balance gene expression and reestablish tissue health. Ongoing industry‐sponsored clinical trials inspire a new miRNA therapeutics era, but progress largely relies on the development of safe and efficient delivery systems. The emerging application of biomaterial scaffolds for this purpose offers spatiotemporal control and circumvents biological and mechanical barriers that impede successful miRNA delivery. The nascent research in scaffold‐mediated miRNA therapies translates know‐how learnt from studies in antitumoral and genetic disorders as well as work on plasmid (p)DNA/siRNA delivery to expand the miRNA therapies arena. In this progress report, the state of the art methods of regulating miRNAs are reviewed. Relevant miRNA delivery vectors and scaffold systems applied to‐date for RM and cancer treatment applications are discussed, as well as the challenges involved in their design. Overall, this progress report demonstrates the opportunity that exists for the application of miRNA‐activated scaffolds in the future of RM and cancer treatments.
In Situ Coupling Strategy for the Preparation of FeCo Alloys and Co4N Hybrid for Highly Efficient Oxygen Evolution
Authors: Zhu Xiang , Jin Tian , Tian Chengcheng , Lu Chenbao , Liu Xiaoming , Zeng Min , Zhuang Xiaodong , Yang Shize , He Lin , Liu Honglai , Dai Sheng
Published: October 2017

An in situ coupling approach is developed to create a new highly efficient and durable cobalt‐based electrocatalyst for the oxygen evolution reaction (OER). Using a novel cyclotetramerization, a task‐specific bimetallic phthalocyanine‐based nanoporous organic framework is successfully built as a precursor for the carbonization synthesis of a nonprecious OER electrocatalyst. The resultant material exhibits an excellent OER activity with a low overpotential of 280 mV at a current density of 10 mA cm−2 and high durability in an alkaline medium. This impressive result ranks among the best from known Co‐based OER catalysts under the same conditions. The simultaneous installation of multiple diverse cobalt‐based active sites, including FeCo alloys and Co4N nanoparticles, plays a critical role in achieving this promising OER performance. This innovative approach not only enables high‐performance OER activity to be achieved but simultaneously provides a means to control the surface features, thereby tuning the catalytic property of the material.
Early diagnosis of lymphoma utilising Doppler pulmonary artery flow imaging
Authors: Su Tonglin , Kritharides Leonard , Chow Vincent
Published: October 2017

This case report illustrates the importance of careful Doppler interrogation of pulmonary artery (PA) and pulmonary artery branches in a standard Echocardiographic examination, which can be easily missed or ignored when using portable hand‐held device as this is usually a focussed examination. A comprehensive echocardiogram with dedicated superior vena cava (SVC) and detailed Doppler analysis of the PA added crucial information in the early diagnosis and expedited the commencement of life‐saving therapy in a 38‐year‐old female patient with lymphoma.
Do geographic differences or socioeconomic disparities affect survival in sinonasal squamous cell carcinoma?
Authors: Zhou Albert H. , Chung Sei Y. , Patel Varesh R. , Unsal Aykut A. , Hsueh Wayne D. , Baredes Soly , Eloy Jean Anderson
Published: October 2017

Background

Squamous cell carcinoma (SCC) is the most common malignancy in the sinonasal tract. We present the first population‐based analysis that examines geographic differences in demographic and clinical characteristics, socioeconomic factors, treatment modality, and disease‐specific survival (DSS) of this entity.

Methods

All cases of sinonasal squamous cell carcinoma (SNSCC) were queried using the U.S. Surveillance, Epidemiology, and End Results (SEER) registry from 1973 to 2013. Patients were stratified by geographic location and characteristics such as demographics (age, gender, race, metropolitan/nonmetropolitan status, and income), stage at diagnosis, and treatment modality. Survival data were generated using Kaplan‐Meier regression analysis.

Results

In total, 6094 patients were identified; 15.3% were from the East, 16.3% from the Midwest, 19.3% from the South, and 49.1% from the West. Patients from the South were younger (p < 0.001). The South had the highest proportion of patients who were black (p < 0.001), lived in nonmetropolitan areas (p < 0.001), and presented with localized disease (p < 0.001). Southern patients also had the lowest median income (p < 0.05), and were least likely to be treated with both surgery and radiotherapy (p < 0.001). The South exhibited the lowest 20‐year DSS compared to all other regions (p < 0.001).

Conclusion

SNSCC patients from the South had the poorest long‐term DSS, despite being most likely to present with localized disease. The South had the highest proportion of patients who were black, resided in rural or urban towns, had the lowest median income, and did not receive standard combination therapy, compared to the East, Midwest, and West.
A Manganese Pre‐Catalyst: Mild Reduction of Amides, Ketones, Aldehydes, and Esters
Authors: Kelly Colin M. , McDonald Robert , Sydora Orson L. , Stradiotto Mark , Turculet Laura
Published: October 2017

A new (N‐phosphinoamidinate)manganese complex is shown to be a useful pre‐catalyst for the hydrosilative reduction of carbonyl compounds, and in most cases at room temperature. The Mn‐catalyzed reduction of tertiary amides to tertiary amines, with a useful scope, is demonstrated for the first time by use of this catalyst, and is competitive with the most effective transition‐metal catalysts known for such transformations. Ketones, aldehydes, and esters were also successfully reduced under mild conditions by using this new Mn catalyst.
More than 50% or Less than 70% Chance: Pragmatic Implications of Single‐Bound Probability Estimates
Authors: Hohle Sigrid Møyner , Teigen Karl Halvor
Published: October 2017

Probability estimates can be given as ranges or uncertainty intervals, where often only one of the interval bounds (lower or upper) is specified. For instance, a climate forecast can describe La Niña as having “more than 70% chance” or “less than 90% chance” of occurring. In three experiments, we studied how research participants perceived climate‐related forecasts expressed with lower‐bound (“over X% chance”) or upper‐bound (“under Y% chance”) probability statements. Results indicate that such single‐bound statements give pragmatic information in addition to the numeric probabilities they convey. First, the studies show that these statements are directional, leading the listeners' attention in opposite directions. “Over” statements guide attention towards the possible occurrence of the event and are explained by reasons for why it might happen, while “under” statements direct attention to its possible non‐occurrence and are more often explained by reasons for why the target event might not appear, corresponding to positive (it is possible) versus negative (it is uncertain) verbal probabilities. Second, boundaries were found to reveal the forecaster's beliefs and could be perceived as indicative of an increasing or a decreasing trend. Single‐bound probability estimates are therefore not neutral communications of probability level but might “leak” information about the speaker's expectations and about past and future developments of the forecast. Copyright © 2017 John Wiley & Sons, Ltd.
Simulation‐based evaluation of the linear‐mixed model in the presence of an increasing proportion of singletons
Authors: Bruyndonckx Robin , Hens Niel , Aerts Marc
Published: October 2017

Data in medical sciences often have a hierarchical structure with lower level units (e.g. children) nested in higher level units (e.g. departments). Several specific but frequently studied settings, mainly in longitudinal and family research, involve a large number of units that tend to be quite small, with units containing only one element referred to as singletons. Regardless of sparseness, hierarchical data should be analyzed with appropriate methodology such as, for example linear‐mixed models. Using a simulation study, based on the structure of a data example on Ceftriaxone consumption in hospitalized children, we assess the impact of an increasing proportion of singletons (0–95%), in data with a low, medium, or high intracluster correlation, on the stability of linear‐mixed models parameter estimates, confidence interval coverage and F test performance. Some techniques that are frequently used in the presence of singletons include ignoring clustering, dropping the singletons from the analysis and grouping the singletons into an artificial unit. We show that both the fixed and random effects estimates and their standard errors are stable in the presence of an increasing proportion of singletons. We demonstrate that ignoring clustering and dropping singletons should be avoided as they come with biased standard error estimates. Grouping the singletons into an artificial unit might be considered, although the linear‐mixed model performs better even when the proportion of singletons is high. We conclude that the linear‐mixed model is stable in the presence of singletons when both lower‐ and higher level sample sizes are fixed. In this setting, the use of remedial measures, such as ignoring clustering and grouping or removing singletons, should be dissuaded.
Brain lesions affecting gait recovery in stroke patients
Authors: Lee Kyoung Bo , Kim Joon Sung , Hong Bo Young , Sul Bomi , Song Seojin , Sung Won Jin , Hwang Byong Yong , Lim Seong Hoon
Published: October 2017

Objectives

Gait recovery is an important goal in stroke patients. Several studies have sought to uncover relationships between specific brain lesions and the recovery of gait, but the effects of specific brain lesions on gait remain unclear. Thus, we investigated the effects of stroke lesions on gait recovery in stroke patients.

Materials and Methods

In total, 30 subjects with stroke were assessed in a retrograde longitudinal observational study. To assess gait function, the functional ambulation category (FAC) was tested four times: initially (within 2 weeks) and 1, 3, and 6 months after the onset of the stroke. Brain lesions were analyzed via overlap, subtraction, and voxel‐based lesion symptom mapping (VLSM).

Results

Ambulation with FAC improved significantly with time. Subtraction analysis showed that involvement of the corona radiata, internal capsule, globus pallidus, and putamen were associated with poor recovery of gait throughout 6 months after onset. The caudate nucleus did influence poor recovery of gait at 6 months after onset. VLSM revealed that corona radiata, internal capsule, globus pallidus, putamen and cingulum were related with poor recovery of gait at 3 months after onset. Corona radiata, internal capsule, globus pallidus, putamen, primary motor cortex, and caudate nucleus were related with poor recovery of gait at 6 months after onset.

Conclusion

Results identified several important brain lesions for gait recovery in patients with stroke. These results may be useful for planning rehabilitation strategies for gait and understanding the prognosis of gait in stroke patients.
Keep your eye on…
Authors: Knopf Alison
Published: October 2017

Your dog's quality of life in interacting with your child

How to encourage preschoolers to eat fruits and vegetables
On mentorship and working with children
Authors: Walters Anne S.
Published: October 2017

In this inaugural column for me, there are big shoes to fill. Throughout his long and distinguished career, Dr. Greg Fritz has touched innumerable lives: patients, families, trainees, and, of course, the readers of this newsletter. I've known him since coming to Brown 30 years ago, and he has been a person I've consulted at nodal and critical points in my career. His colleagues have watched him navigate the complexities of academic, clinical, and advocacy leadership with passion, exuberance, and humility. He has been (and probably will continue to be) a mentor to so many. And now he knows when to pass the torch in these many roles. These are good lessons for the rest of us.
Ostial right coronary chronic total occlusion: Transesophageal echocardiographic guidance for retrograde aortic re‐entry
Authors: Corrigan Frank E. , Karmpaliotis Dimitrios , Samady Habib , Lerakis Stamatios
Published: October 2017

As antegrade options are limited, intervention upon the ostial right coronary artery (RCA) chronic total occlusion (CTO) warrants a retrograde approach. Landmarks for an aggressive approach are concerning as passage of stiff guidewires or electrocautery near the RCA ostium may result in wire passage into structures other than the aorta. We report the first use of transesophageal echocardiography (TEE) to assist retrograde passage of a guidewire into the aorta. For the ostial RCA CTO, TEE guidance may be considered to assist retrograde passage of aggressive guidewires into the aorta.
A case of empyema and septic arthritis due to Nocardia farcinica
Authors: Ishiguro Takashi , Yoshioka Hiroaki , Kawai Shoko , Katsumata Shin‐ichi , Gonoi Tohru , Takayanagi Noboru
Published: October 2017

Key Clinical Message

Septic arthritis due to Nocardia sp. should be suspected when a patient with risk factors such as pneumoconiosis or diabetes mellitus develops joint symptoms, especially if the patient has had nocardiosis in other sites.
Nitrite‐Enhanced Charge Transfer to and from Single Polyaniline Nanotubes
Authors: Liu Jianyun , Li Xiuting , Batchelor‐McAuley Christopher , Zhu Guodong , Compton Richard G.
Published: October 2017

As Liu et al. reported previously (Appl. Mater. Today 2017, 7, 239–245), the charge transfer to partially oxidized polyaniline (PANI) nanotubes in electrochemical reactions is heavily limited due to the non‐conductivity of the reduction/oxidation products. In this paper, the doping level of individual PANI nanotubes was substantially enhanced using nitrite as an electron acceptor in sulfuric acid aqueous solution as recorded by the nano‐impact method. The charge transferred to one single tube during reduction process is close to the theoretical value of 170±112 pC per tube (assuming 2‐electron reduction for the PANI tubes studied), while the charge during PANI oxidation is dramatically decreased. Reaction processes are proposed based on the oxidative properties of nitrite in acid solution. UV–visible spectroscopy analysis further confirms an oxidation–reduction reaction between PANI and nitrite. In contrast the electrochemical reaction of ensembles (21 μg cm−1) of PANI tubes on glassy carbon electrodes simply show limited electrocatalytic activity.
An {As4Cu4[Cu(H2O)]12} Cluster Incorporated within Four [Nb7O22]9− Units
Authors: Li Li , Dong Kaili , Ma Pengtao , Zhang Chao , Niu Jingyang , Wang Jingping
Published: October 2017

A gigantic 16‐copper‐containing 28‐niobate cluster, Na14K7H5{As4Cu4[Cu(H2O)]12Nb28O109}⋅37.5 H2O (1), has been prepared by a one‐pot reaction, which is the first example of arsenic copper clusters containing polyoxoniobate, and the first tetrahedral arrangement of both the Cu cluster and the [Nb7O22]9− subunits.
Antimicrobial Peptide Structures: From Model Membranes to Live Cells
Authors: Sani Marc‐Antoine , Separovic Frances
Published: October 2017

The rise in antibiotic resistance has led to a renewed interest in antimicrobial peptides (AMPs) that target membranes. The mode of action of AMPs involves the disruption of the lipid bilayer and leads to growth inhibition and death of the bacteria. However, details at the molecular level of how these peptides kill bacteria and the reasons for the observed differences in selectivity remain unclear. Structural information is crucial for defining the molecular mechanism by which these peptides recognize, self‐assemble and interact with a particular lipid membrane. Solid‐state NMR is a non‐invasive technique that allows the study of the structural details of lipid–peptide and peptide–peptide interactions. Following on from studies of antibiotic and lytic peptides, gramicidin A and melittin, respectively, we investigated maculatin 1.1, an AMP from the skin of Australian tree frogs that acts against Gram‐positive bacteria. By using perdeuterated phospholipids and specifically labelled peptides, 2H, 31P and {31P}15N REDOR solid‐state NMR experiments have been used to localize, maculatin 1.1 in neutral and anionic model membranes. However, the structure, location and activity depend on the composition of the model membrane and current advances in solid‐state NMR spectroscopy now allow structure determination of AMPs in live bacteria.
Increasing the Reactivity of Diborenes: Derivatization of NHC‐Supported Dithienyldiborenes with Electron‐Donor Groups
Authors: Auerhammer Dominic , Arrowsmith Merle , Bissinger Philipp , Braunschweig Holger , Dellermann Theresa , Kupfer Thomas , Lenczyk Carsten , Roy Dipak K. , Schäfer Marius , Schneider Christoph
Published: October 2017

A series of NHC‐supported 1,2‐dithienyldiborenes was synthesized from the corresponding (dihalo)thienylborane NHC precursors. NMR and UV/Vis spectroscopic data, as well as X‐ray crystallographic analyses, were used to assess the electronic and steric influences on the B=B double bond of various NHCs and electron‐donating substituents on the thienyl ligands. Crystallographic data showed that the degree of coplanarity of the diborene core and thienyl groups is highly dependent on the sterics of the substituents. Furthermore, any increase in the electron‐donating ability of the substituents resulted in the destabilization of the HOMO and greater instability of the resulting diborenes.
On Pentakis(pentafluoroethyl)stannate, [Sn(C2F5)5]−, and the Gas‐Free Generation of Pentafluoroethyllithium, LiC2F5
Authors: Wiesemann Markus , Klösener Johannes , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold
Published: October 2017

Pentafluoroethyllithium, LiC2F5, has been established as an efficient and versatile reagent for the transfer of the pentafluoroethyl unit to a number of electrophiles. Here, the stability of this species up to −40 °C is of advantage, particularly in comparison to its smaller congener LiCF3. The usual production of LiC2F5, however, from gaseous HC2F5 or IC2F5 and strong bases requires specially designed apparatuses, which severely impeded its value as a laboratory reagent. In this contribution we communicate an alternative gas‐free and highly efficient protocol for the synthesis of LiC2F5 from the already commercialized stannate salt [PPh4][Sn(C2F5)5]. The [Sn(C2F5)5]− anion represents not only the first example of a structurally characterized hypervalent pentaalkylstannate but also serves as a precursor for the synthesis of the homoleptic tetrakis(pentafluoroethyl)stannane, Sn(C2F5)4. The reaction of the latter with n‐butyllithium provides an insight into the mechanism of LiC2F5 generation.
Prozessmodelle in der Verfahrenstechnik: Ein langer Weg
Authors: Repke Jens‐Uwe
Published: October 2017

No abstract.
Support work‐life balance to help staff avoid burnout
Authors: Williams Kate
Published: October 2017

“If you can take a vacation, then they don't need you,” my father told me over the table as we ate dinner one Thursday night. His comment mirrored the strong work ethic that he has demonstrated his entire life, a model that I, as a first‐born, Type‐A child, have tried to emulate but have found difficult to do.
Understand the top facts academic administrators should know about campus safety
Authors: Hope Joan
Published: October 2017

A safe campus is key to students, faculty, and staff focusing on academic pursuits. As an academic administrator, what can you do to ensure that your campus is as safe as possible?
Advance institution's mission, increase student satisfaction with customer service approach
Authors: Sutton Halley
Published: October 2017

Sharon Hoffman brought an unusual work experience to her position as assistant dean of student services at Green Mountain College: her time as a concierge at a ski resort in the mountains of Vermont, a few hours from where the campus is located. When the current president came to GMC after working for the Vermont Country Store, he wanted to address what he perceived as “customer service issues” on the campus. He wanted to change the culture of customer service, and Hoffman's experience working at the ski resort in Killington made her an ideal candidate to work there, she said.
Historical Biogeography of endemic seed plant genera in the Caribbean: Did GAARlandia play a role?
Authors: Nieto‐Blázquez María Esther , Antonelli Alexandre , Roncal Julissa
Published: October 2017

The Caribbean archipelago is a region with an extremely complex geological history and an outstanding plant diversity with high levels of endemism. The aim of this study was to better understand the historical assembly and evolution of endemic seed plant genera in the Caribbean, by first determining divergence times of endemic genera to test whether the hypothesized Greater Antilles and Aves Ridge (GAARlandia) land bridge played a role in the archipelago colonization and second by testing South America as the main colonization source as expected by the position of landmasses and recent evidence of an asymmetrical biotic interchange. We reconstructed a dated molecular phylogenetic tree for 625 seed plants including 32 Caribbean endemic genera using Bayesian inference and ten calibrations. To estimate the geographic range of the ancestors of endemic genera, we performed a model selection between a null and two complex biogeographic models that included timeframes based on geological information, dispersal probabilities, and directionality among regions. Crown ages for endemic genera ranged from Early Eocene (53.1 Ma) to Late Pliocene (3.4 Ma). Confidence intervals for divergence times (crown and/or stem ages) of 22 endemic genera occurred within the GAARlandia time frame. Contrary to expectations, the Antilles appears as the main ancestral area for endemic seed plant genera and only five genera had a South American origin. In contrast to patterns shown for vertebrates and other organisms and based on our sampling, we conclude that GAARlandia did not act as a colonization route for plants between South America and the Antilles. Further studies on Caribbean plant dispersal at the species and population levels will be required to reveal finer‐scale biogeographic patterns and mechanisms.
Post aus dem Universum
Authors: Beck Alexander , Klein Ulrich , Lesch Harald
Published: October 2017

Astrophysik: Die Milchstraße als Heimatgalaxie unserer Erde hat sie, und alle anderen Galaxien haben sie auch – großräumige kosmische Magnetfelder. Um ihre Entstehung und Entwicklung zu verstehen, kombinieren Forscher radioteleskopische Beobachtungen des Himmels mit numerischen Simulationen am Computer. Das führt sie zu neuen Erkenntnissen an den Grenzen bisherigen Wissens.
Von Hand zu Herz
Authors: Hatzfeld Christian , Koev Nataliya , Werthschützky Roland
Published: October 2017

Untersuchungen mit dem Herzkatheter sind längst millionenfache Routine – und doch mit Risiken verbunden. Ingenieure haben nun ein Assistenzsystem entwickelt, das den Führungsdraht mit einem miniaturisierten Kraftsensor leichter und präziser navigieren lässt und dem Kardiologen haptische Rückmeldungen gibt.
#Smartphone‐Gemeinschaften
Authors: Unterstell Rembert
Published: October 2017

WhatsApp, Snapchat oder Pokémon GO: Die Konstanzer Medienwissenschaftlerin und Heinz Maier‐Leibnitz‐Preisträgerin Isabell Otto untersucht die modernen Digitalmedien mit kulturwissenschaftlichem Esprit / Mediale Teilhabe zwischen Erwartung und Zumutung
Impact of Platinum Loading on Performance and Degradation of Polymer Electrolyte Fuel Cell Electrodes Studied in a Rainbow Stack
Authors: Gazdzicki P. , Mitzel J. , Dreizler A. M. , Schulze M. , Friedrich K. A.
Published: October 2017

The paper focuses on the investigation of durability and performance of a low temperature polymer electrolyte membrane fuel cell (PEMFC) stack as a function of Pt loading in automotive test conditions. Major motivations are problems related to the need to reduce the amount of Pt in membrane electrode assemblies (MEAs) in order to make PEMFC more competitive. The particular challenge is to maintain sufficiently high performance and long‐term durability. The study shows that for cathode Pt loadings below 0.2 mg cm−2 and for current densities exceeding 1 A cm−2 a sudden drop of performance is observed. The same threshold value is found for the increase of irreversible voltage losses which lead to an intense reduction of PEMFC durability for cathodic loadings below 0.2 mg cm−2. Another durability issue at cathodic Pt loadings < 0.4 mg cm−2 is the acceleration of reversible degradation, which leads to a strong voltage drop during continues fuel cell operation (i.e., without a recovery interruption).
Synthesis and Biological Evaluation of some 3d Metal Complexes with a Novel Heterocyclic Schiff Base
Authors: Thomas Preethy Soosan , Mohanan Kochukittan
Published: October 2017

A heterocyclic Schiff base was prepared by condensing 3‐acetylcoumarin with 2‐amino‐3‐carboxyethyl‐4,5,6,7‐tetrahydrobenzo[b]thiophene. Such Schiff bases derived from two different heterocyclic moieties are rare and expected to have properties surpassing those of either of the parent compounds in effectiveness of complex formation and biological activities. This ligand formed a series of complexes with manganese(II), cobalt(II), nickel(II), copper(II), and zinc(II) ions. The ligand and the metal complexes were characterized by various physicochemical and spectral studies. These included elemental analysis, molar conductance, magnetic susceptibility, as well as UV–vis, IR, 1H NMR, 13C NMR, and ESR spectral studies. The ESR spectral data adequately supported the covalent nature of the metal–ligand bonds. The ligand possessed a hexagonal crystal structure, but on complexation the crystallinity was lost. The fluorescence spectra of the ligand and its metal complexes in DMSO were also recorded. The ligand and the metal complexes were screened for their antimicrobial activities, and it was observed that the metal complexes are more active than the ligand. The α‐amylase inhibitory activity and the DNA cleavage activity of the ligand and the metal complexes were also examined. in vitro antitumor activity of the copper(II) complex was assayed against human cervical carcinoma cells (HeLa cell line), showing that the complex exhibited promising antitumor activity on the HeLa cell line.
Cultural stressors, identity development, and substance use attitudes among Hispanic immigrant adolescents
Authors: Grigsby Timothy J. , Forster Myriam , Meca Alan , Zamboanga Byron L. , Schwartz Seth J. , Unger Jennifer B.
Published: October 2017

The goal of this investigation was to determine whether various cultural stressors (bicultural stress, perceived discrimination, and perceived negative context of reception [PNCR]) predict positive and negative substance use attitudes, directly and indirectly through personal identity, in a sample of immigrant Hispanic adolescents. Data on cultural stressors, substance use attitudes, and covariates were collected from 302 Hispanic immigrant adolescents (152 from Miami [61% Cuban] and 150 from Los Angeles [70% Mexican]) at 3 time points. PNCR was associated with identity confusion (β = .175, p = .033). Identity confusion significantly predicted higher positive attitudes toward alcohol and other drug (AOD; β = .216, p < .001) and cigarette use (β = .191, p = .015) and mediated the relationship between PNCR with unfavorable AOD attitudes (β = −.019, 95% confidence interval [CI] [− 0.052, − 0.001]) and favorable AOD attitudes (β = 0.038, 95% CI [0.003, 0.086]). Perceptions of a negative context of reception may hinder successful personal identity formation and impact health outcomes for immigrant youth.
Development of the muscles associated with the mandibular and hyoid arches in the Siberian sturgeon, Acipenser baerii (Acipenseriformes: Acipenseridae)
Authors: Warth Peter , Hilton Eric J. , Naumann Benjamin , Olsson Lennart , Konstantinidis Peter
Published: October 2017

The skeleton of the jaws and neurocranium of sturgeons (Acipenseridae) are connected only through the hyoid arch. This arrangement allows considerable protrusion and retraction of the jaws and is highly specialized among ray‐finned fishes (Actinopterygii). To better understand the unique morphology and the evolution of the jaw apparatus in Acipenseridae, we investigated the development of the muscles of the mandibular and hyoid arches of the Siberian sturgeon, Acipenser baerii. We used a combination of antibody staining and formalin‐induced fluorescence of tissues imaged with confocal microscopy and subsequent three‐dimensional reconstruction. These data were analyzed to address the identity of previously controversial and newly discovered muscle portions. Our results indicate that the anlagen of the muscles in A. baerii develop similarly to those of other actinopterygians, although they differ by not differentiating into distinct muscles. This is exemplified by the subpartitioning of the m. adductor mandibulae as well as the massive m. protractor hyomandibulae, for which we found a previously undescribed portion in each. The importance of paedomorphosis for the evolution of Acipenseriformes has been discussed before and our results indicate that the muscles of the mandibular and the hyoid may be another example for heterochronic evolution.
Degradation alters the lubrication of articular cartilage by high viscosity, hyaluronic acid‐based lubricants
Authors: Bonnevie Edward D. , Galesso Devis , Secchieri Cynthia , Bonassar Lawrence J.
Published: October 2017

Hyaluronic acid (HA) is widely injected as a viscosupplement in the treatment of osteoarthritis. Despite its extensive use, it is not currently known if cartilage degradation alters how HA‐based solutions lubricate the articular surface. In this study we utilized a model of cartilage degradation by IL‐1β along with a recently developed framework to study role of cartilage degradation on lubrication by clinically‐approved HA‐based lubricants with high viscosities. Cartilage explants were cultured up to 8 days with 10 ng/ml IL‐1β. After culture, samples were examined histologically, immunohistochemically, biochemically, mechanically, topographically, and tribologically. The tribological testing analyzed both boundary and mixed lubrication modes to assess individual effects of viscosity and boundary lubricating ability. Friction testing was carried out using PBS and two clinically approved HA‐based viscosupplements in a cartilage‐glass configuration. After culture with IL‐1β, boundary mode friction was elevated after both 4 and 8 days. Additionally, friction in mixed mode lubrication, where HA is most effective as a lubricant, was significantly elevated after 8 days of culture. As cartilage became rougher, softer, and more permeable after culture, the boundary mode plateau was extended, and as a result, significantly increased lubricant viscosities or sliding speeds were necessary to achieve effective mixed lubrication. Overall, this study revealed that lubrication of cartilage by HA is degradation‐dependent and coincides with changes in mechanics and roughness. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1456–1464, 2018.
Temporal variability in composition and fluxes of Yellow River particulate organic matter
Authors: Tao Shuqin , Eglinton Timothy I. , Zhang Liang , Yi Zhiwei , Montluçon Daniel B. , McIntyre Cameron , Yu Meng , Zhao Meixun
Published: October 2017

This study examines temporal variations of the abundance and carbon isotopic characteristics of particulate organic carbon (POC) and specific‐source compounds in the context of hydrological variability in the Yellow River. The content and bulk carbon isotopic characteristics (13C and 14C) of POC were relatively uniform over the hydrologic (seasonal) cycle. We attribute these temporally invariant geochemical characteristics to the dominant contribution of loess material to the suspended particulate matter (SPM). In contrast, molecular‐level signals revealed that hydrologic conditions exert a significant influence on the proportional contributions of petrogenic and especially fresh plant‐derived OC, while pre‐aged soil OC is mobilized via deeper erosion processes (e.g., gully erosion, mudslides) and is independent of hydrodynamics and surface runoff. A coupled biomarker‐isotope mixing model was applied to estimate the time‐varying supply of contemporary/modern biomass, pre‐aged soil, and fossil OC components to Chinese marginal seas from the Yellow River. We found that natural (e.g., precipitation) and human‐induced (e.g., water and sediment regulation) variations in hydrological regime strongly influence the flux with the magnitude of the corresponding annual fluxes of POC ranging between 0.343 ± 0.122 Mt yr−1 and 0.581 ± 0.213 Mt yr−1, but less strongly infleunce proportions of the different OC constituents. Inter‐annual differences in pre‐aged soil and fossil OC fluxes imply that extreme climate events (e.g., floods) modulate the exhumation and export of old carbon to the ocean, but the OC homogeneity in the pre‐aged mineral soil‐dominated watersheds facilitates robust predictions in terms of OC transport dynamics in the past (sediment cores) and in the future.
Kelp detritus provides high‐quality food for sea urchin larvae
Authors: Feehan Colette J. , Grauman‐Boss Beatrice C. , Strathmann Richard R. , Dethier Megan N. , Duggins David O.
Published: October 2017

Highly productive kelps release abundant particulate organic matter into the nearshore environment due to their constant fragmentation and erosion by ocean waves. The contribution of kelp detritus to coastal planktonic food webs has not previously been examined. Here, we demonstrate that detritus derived from a dominant kelp in the Northeast Pacific, Nereocystis luetkeana, provides high‐quality food for planktonic sea urchin larvae. Our findings challenge the paradigm that phytoplankton are the main diet for zooplankton in nearshore regions, with implications for modeling of ocean production. Furthermore, at the benthic adult stage, sea urchins can destructively graze kelps causing the kelp ecosystem to collapse; hence, our results have implications for understanding feedback mechanisms that may determine the resilience of kelp ecosystems.
Alkali‐Mediated Miscibility of Gelatin/Polycaprolactone for Electrospinning Homogeneous Composite Nanofibers for Tissue Scaffolding
Authors: Zhou Qihui , Zhang Huilan , Zhou Ya , Yu Zhepao , Yuan Huihua , Feng Bei , van Rijn Patrick , Zhang Yanzhong
Published: October 2017

Electrospun natural‐synthetic composite nanofibers, which possess favorable biological and mechanical properties, have gained widespread attention in tissue engineering. However, the development of biomimetic nanofibers of hybrids remains a huge challenge due to phase separation of the polymer blends. Here, aqueous sodium hydroxide (NaOH) solution is proposed to modulate the miscibility of a representative natural‐synthetic hybrid of gelatin (GT) and polycaprolactone (PCL) for electrospinning homogeneous composite nanofibers. Alkali‐doped GT/PCL solutions and nanofibers examined at macroscopic, microscopic, and internal molecular levels demonstrate appropriate miscibility of GT and PCL after introducing the alkali dopant. Particularly, homogeneous GT/PCL nanofibers with smooth surface and uniform diameter are obtained when aqueous NaOH solution with a concentration of 10 m is used. The fibers become more hydrophilic and possess improved mechanical properties both in dry and wet conditions. Moreover, biocompatibility experiments show that stem cells adhere to and proliferate better on the alkali‐modified nanofibers than the untreated one. This study provides a facile and effective approach to solve the phase separation issue of the synthetic‐natural hybrid GT/PCL and establishes a correlation of compositionally and morphologically homogeneous composite nanofibers with respect to cell responses.