bluuebunny/crossref_metadata_2025 huggingface dataset:
Reculturing Pedagogical Practice: Probing Teachers’ Cultural Models of Pedagogy
Authors: Chafi Essaid , Elkhouzai Elmostapha
Published: February 2017

A number of educational reform attempts, chief among which are pedagogy by objectives, competency-based approach, and pedagogy of integration, have been made to establish pedagogical reform in Moroccan public primary school. However, results have not been up to par. Failure of school reform has been largely rationalized in terms of technical problems associated with innovation delivery system. By adopting a “technicist” stance towards issues of pedagogical reform, decision makers and curriculum developers have paid a scant attention to the fact that pedagogical innovations are social constructions, and as such value-laden. The institutionalization of pedagogical frameworks import has so far failed to take into account the local sociocultural meanings. A close look into our classrooms shapes an understanding why prevailing traditional practices persist in spite of the progressive ideals advocated in reform packages. Pedagogy is more than techniques; it is deeply embedded in the sociocultural context. Upgrading pedagogical practice requires a sociocultural approach in which the nature of the cultural perspective of pedagogy is recognized and failure of pedagogical reform is also sought in the workings of the enveloping social structure. Such a cultural undertaking of pedagogy can be fulfilled by probing teachers’ cultural models of pedagogy. Without proper examination and understanding of teachers’ conceptualization of pedagogy and how it reflects on classroom practice, it will be difficult to determine an appropriate focus for pedagogical reform. Therefore, the study of teachers’ cultural models of pedagogy has the potential to provide reflective insight into many facets of teachers’ thinking and practice. Attentiveness to cultural models of pedagogy can lead and enlighten educational practice towards directions that current research has not explored yet.
Functional KRAS mutations and a potential role for PI3K/AKT activation in Wilms tumors
Authors: Polosukhina Dina , Love Harold D. , Correa Hernan , Su Zengliu , Dahlman Kimberly B. , Pao William , Moses Harold L. , Arteaga Carlos L. , Lovvorn Harold N. , Zent Roy , Clark Peter E.
Published: February 2017

Wilms tumor (WT) is the most common renal neoplasm of childhood and affects 1 in 10 000 children aged less than 15 years. These embryonal tumors are thought to arise from primitive nephrogenic rests that derive from the metanephric mesenchyme during kidney development and are characterized partly by increased Wnt/β‐catenin signaling. We previously showed that coordinate activation of Ras and β‐catenin accelerates the growth and metastatic progression of a murine WT model. Here, we show that activating KRAS mutations can be found in human WT. In addition, high levels of phosphorylated AKT are present in the majority of WT. We further show in a mouse model and in renal epithelial cells that Ras cooperates with β‐catenin to drive metastatic disease progression and promotes in vitro tumor cell growth, migration, and colony formation in soft agar. Cellular transformation and metastatic disease progression of WT cells are in part dependent on PI3K/AKT activation and are inhibited via pharmacological inhibition of this pathway. Our studies suggest both KRAS mutations and AKT activation are present in WT and may represent novel therapeutic targets for this disease.
A global estimate of the full oceanic 13C Suess effect since the preindustrial
Authors: Eide Marie , Olsen Are , Ninnemann Ulysses S. , Eldevik Tor
Published: February 2017

We present the first estimate of the full global ocean 13C Suess effect since preindustrial times, based on observations. This has been derived by first using the method of Olsen and Ninnemann (2010) to calculate 13C Suess effect estimates on sections spanning the world ocean, which were next mapped on a global 1° × 1° grid. We find a strong 13C Suess effect in the upper 1000 m of all basins, with strongest decrease in the subtropical gyres of the Northern Hemisphere, where δ13C of dissolved inorganic carbon has decreased by more than 0.8‰ since the industrial revolution. At greater depths, a significant 13C Suess effect can only be detected in the northern parts of the North Atlantic Ocean. The relationship between the 13C Suess effect and the concentration of anthropogenic carbon varies strongly between water masses, reflecting the degree to which source waters are equilibrated with the atmospheric 13C Suess effect before sinking. Finally, we estimate a global ocean inventory of anthropogenic CO2 of 92 ± 46 Gt C. This provides an estimate that is almost independent of and consistent, within the uncertainties, with previous estimates.
Neogene paleoceanography of the eastern equatorial Pacific based on the radiolarian record of IODP drill sites off Costa Rica
Authors: Sandoval María I. , Boltovskoy Demetrio , Baxter Alan T. , Baumgartner Peter O.
Published: February 2017

The Integrated Ocean Drilling Program (IODP) Expedition 344 drilled cores following a transect across the convergent margin off Costa Rica. Two of the five sites (U1381 and U1414) are the subject of the present study. Major radiolarian faunal breaks and characteristic species groups were defined with the aid of cluster analysis, nodal analysis, and discriminant analysis of principal components. A middle‐late Miocene to Pleistocene age (radiolarian zones RN5 to RN16) was determined for the sites, which agrees with the nannofossil zonations and 40Ar/39Ar and tephra layers. Considering the northward movement of the Cocos plate (∼7.3 cm/yr), and a paleolatitude calculator, it is assumed that during the Miocene the two sites were located ∼1000 km to the southwest of their current position, slightly south of the equator. The radiolarian faunas retrieved were thus seemingly formed under the influence of different oceanic currents and sources of nutrients. Changes in the radiolarian assemblages at Site U1414 point at dissimilar environmental settings associated with the colder South Equatorial Current and the warmer Equatorial Countercurrent, as well as to coastal upwelling. These differences are best reflected by changes in the abundance of the morphotype Spongurus spp., with noticeably higher values during the Miocene, than in the Pliocene and the Pleistocene. Because Spongurus spp. is generally associated with cooler waters, these abundance variations (as well as those of several other species) suggest that during the Miocene the area had a stronger influence of colder waters than during younger periods. During the Pliocene and the lowermost Pleistocene, biogenic remains are scarce, presumably due to the terrigenous input, which could have diluted and affected the preservation of pelagic fossils, as well as to the displacement of the site to warmer waters. A typically tropical fauna characterized the Pleistocene, yet with widespread presence of colder water species, most probably indicative of the influence of coastal upwelling processes.
Seasonal and interannual variability of the Eastern Tropical Pacific Fresh Pool
Authors: Guimbard S. , Reul N. , Chapron B. , Umbert M. , Maes C.
Published: February 2017

The Eastern Pacific Fresh Pool (EPFP) is a large region of low sea surface salinity (SSS) defined by values lower than 34 practical salinity scale within (5°S–30°N, 75°W–180°W). The fresh pool dynamically responds to strong regional and seasonally varying ocean‐atmosphere‐land interactions (including monsoon rain, trade and gap winds, and strong currents). Using more than 5 years of Soil Moisture and Ocean Salinity (SMOS) satellite sea surface salinity (SSS) and complementary satellite wind, rain, currents, and sea surface temperature data together with a historical ensemble of in situ products, the present study explores the seasonal and interannual dynamics of the fresh pool over the period 2004–2015. An important interannual variability of the maximal surface extension of the EPFP over the past decade is revealed with two extreme events (2012, 2015) occurring during the SMOS satellite period. These extremes are found to be related to the El Niño‐Southern Oscillation (ENSO) phases and associated anomalies of precipitation, surface currents, and trade wind in the central Pacific. In 2012 (La Niña), stronger trade winds coupled with a deficit of precipitation induced a minimum extension of the pool during the rainy season. Whereas, during the strong El Niño 2014–2015, the EPFP extension reached an unprecedented maximum value. A modification of the atmospheric freshwater fluxes and ocean surface currents during winter 2014 is found to have favored the onset of this abnormal fresh event.
The study of droplet‐laden turbulent airflow over waved water surface by direct numerical simulation
Authors: Druzhinin O. A. , Troitskaya Yu. I. , Zilitinkevich S. S.
Published: February 2017

The objective of the present paper is to elucidate possible effects of sea spray on the momentum transfer in marine boundary layer under strong wind forcing conditions by performing direct numerical simulation (DNS) of turbulent, droplet‐laden airflow over a waved water surface. Three‐dimensional, turbulent Couette airflow is considered in DNS as a model of a constant‐flux layer in the atmospheric surface layer. Two‐dimensional stationary waves at the water surface are prescribed and assumed to be unaffected by the airflow and/or droplets. Droplets are considered as nondeformable spheres and tracked in a Lagrangian framework, and their impact on the carrier flow is modeled with the use of a point‐force approximation. The results show that drops dynamics and their impact on the carrier airflow is controlled by the drops velocity at injection, the ratio of drops gravitational settling velocity versus the product of air friction velocity and Karman constant (
), and the wave slope, ka. Drops injected into the flow with the surrounding airflow velocity reduce the turbulent air‐stress and increase mean air velocity as compared to the droplet‐free case. On the other hand, the opposite effect is observed for drops injected with velocity equal to the water surface velocity, which increase the turbulent air stress and reduce the mean wind velocity. This modification of the airflow by drops is most pronounced for the ratio
, increases with drops mass loading, and is reduced for steeper waves and smaller settling velocity.
On the response of the Lorenz energy cycle for the Southern Ocean to intensified westerlies
Authors: Wu Yang , Wang Zhaomin , Liu Chengyan
Published: February 2017

The potential impact of intensified westerlies on the Lorenz energy cycle for the Southern Ocean is examined by employing a global eddy‐permitting ocean‐sea ice model. Two idealized sensitivity experiments are designed for this purpose: one is driven by 1992 forcing with weaker westerlies and the other driven by 1998 forcing with stronger westerlies. The intensified westerlies lead to the most significant increase of about 30% in the eddy kinetic energy (EKE) reservoir, followed by the mean kinetic energy (MKE) reservoir increase (17.9%), eddy available potential energy (EAPE) reservoir increase (8.6%), and mean available potential energy (MAPE) reservoir increase (6.5%). In contrast, the increases in the generations of kinetic energy and available potential energy are quite similar, ranging from 21% for EAPE generation to 26% for MKE generation. There are considerably increased energy transfers from MKE to MAPE (about 75%) and from MAPE to EAPE (about 78%), reflecting greatly enhanced baroclinic instability pathway. The conversion rates are strongly influenced by large topography; in particular, a relatively large energy conversion from EKE to MKE exists in the regions associated with large topography, in contrast to the energy flow from MKE to EKE over the broad Southern Ocean. Under stronger wind forcing, all energy conversions are enhanced, and the increases in the conversion rates from EAPE to EKE and from EKE to MKE are more prominent than the increases from MKE to MAPE and from MAPE to EAPE near large topography.
Reconstructing diet in Napoleon's Grand Army using stable carbon and nitrogen isotope analysis
Authors: Holder Sammantha , Dupras Tosha L. , Jankauskas Rimantas , Williams Lana , Schultz John
Published: February 2017

Objectives

Historical evidence has provided information regarding disease and mortality in Napoleon Bonaparte's Grand Army, but dietary information beyond individual soldier accounts remains scarce. The purpose of this research is to reconstruct the diets of Napoleon's multiethnic army who were associated with the Russian Campaign of 1812.

Materials and Methods

We conducted stable carbon and nitrogen isotope ratio analysis on femoral bone collagen of 78 individuals recovered from a salvage excavation at the mass gravesite of Šiaurės miestelis in Vilnius, Lithuania. These individuals were later discovered to be Napoleonic soldiers and camp followers who participated in the 1812 Russian Campaign.

Results

Stable carbon isotope ratios range from −19.2‰ to −11.8‰, with a mean of −17.8‰ ± 1.5‰ (1 σ). Stable nitrogen isotope ratios range from 7.1‰ to 13.6‰, with a mean of 10.5‰ ± 1.4‰ (1 σ). Both δ13C and δ15N values show a wide range of variation.

Discussion

Stable isotope data indicate considerable dietary variation in this population associated with a multiethnic and socially stratified military population. Diets ranged from predominantly C3‐based to predominantly C4‐based, with varying inputs of terrestrial, freshwater, and marine animal protein. Comparison with other European populations further denotes the exceptional range of dietary variation of soldiers and camp followers in Napoleon's army.
Blood–brain barrier breakdown in reversible cerebral vasoconstriction syndrome: Implications for pathophysiology and diagnosis
Authors: Lee Mi Ji , Cha Jihoon , Choi Hyun Ah , Woo Sook‐Young , Kim Seonwoo , Wang Shuu‐Jiun , Chung Chin‐Sang
Published: February 2017

Objective

Diagnosis of reversible cerebral vasoconstriction syndrome (RCVS) is currently based on luminographic findings of vasoconstriction. In addition to vasoconstriction, the blood–brain barrier (BBB) breakdown has been postulated as a central mechanism of RCVS. Our aim was to document BBB breakdown in patients with RCVS and its role for the pathophysiology‐based diagnosis of RCVS.

Methods

We prospectively recruited 72 consecutive patients with thunderclap headache who did not have aneurysmal subarachnoid hemorrhage from April 2015 to July 2016 at the Samsung Medical Center. Based on the International Classification of Headache Disorders–3 beta criteria and neuroimaging, patients were classified as having RCVS (n = 41; “definite” in 29 imaging‐proven patients and “probable” in 12 imaging‐negative patients), other secondary causes (n = 7), and thunderclap headache of undetermined cause (n = 24). BBB breakdown was evaluated using contrast‐enhanced fluid‐attenuated inversion recovery magnetic resonance imaging.

Results

BBB breakdown was documented in 20 (69.0%) patients with definite RCVS, 3 (25.0%) patients with probable RCVS, and none with other secondary causes. BBB breakdown was present in RCVS patients with (n = 4) and without (n = 19) concomitant posterior reversible encephalopathy syndrome. In patients with RCVS, the extent of BBB breakdown was independently associated with neurological complications (multivariate odds ratio = 1.48 per 1 territorial increase, 95% confidence interval = 1.04–2.12, adjusted p = 0.032). Three (12.5%) patients with thunderclap headache of undetermined cause were newly classified as having RCVS by the presence of BBB breakdown.

Interpretation

This is the first study to show BBB breakdown in patients with RCVS. This finding might broaden our understanding of the pathophysiology and clinical spectrum of RCVS. Ann Neurol 2017;81:454–466
Solid‐state NMR and EPR Spectroscopy of Mn2+‐Substituted ATP‐Fueled Protein Engines
Authors: Wiegand Thomas , Lacabanne Denis , Keller Katharina , Cadalbert Riccardo , Lecoq Lauriane , Yulikov Maxim , Terradot Laurent , Jeschke Gunnar , Meier Beat H. , Böckmann Anja
Published: February 2017

Paramagnetic metal ions deliver structural information both in EPR and solid‐state NMR experiments, offering a profitable synergetic approach to study bio‐macromolecules. We demonstrate the spectral consequences of Mg2+/ Mn2+ substitution and the resulting information contents for two different ATP:Mg2+‐fueled protein engines, a DnaB helicase from Helicobacter pylori active in the bacterial replisome, and the ABC transporter BmrA, a bacterial efflux pump. We show that, while EPR spectra report on metal binding and provide information on the geometry of the metal centers in the proteins, paramagnetic relaxation enhancements identified in the NMR spectra can be used to localize residues at the binding site. Protein engines are ubiquitous and the methods described herein should be applicable in a broad context.
Dielectric relaxations in phosphoric acid‐doped poly(2,5‐benzimidazole) and its composite membranes
Authors: Saleha Wasim F. G. , Ramesh Rahul , Nalajala Naresh , Ladewig Bradley P. , Neergat Manoj
Published: February 2017

Poly(2,5‐benzimidazole) (ABPBI)—a promising high‐temperature polymer electrolyte membrane—is characterized over a wide range of temperature (−50 to 220 °C) using broadband dielectric spectroscopy (BDS) to understand the various relaxation processes. The undoped ABPBI membrane shows two major secondary relaxations and a primary α relaxation. The effect of phosphoric acid (PA) and phosphotungstic acid grafted zirconium dioxide (PWA/ZrO2) nanoparticles on the chain relaxation and the proton conductivity is investigated. The phosphoric acid alters the relaxation trends, increases the number of free ions in the polymer matrix, and therefore the conductivity. The shift in the peak frequencies of different chain relaxation processes in the presence of PA and PWA/ZrO2 is attributed to the increase in free volume and the consequent easy motion of the polymer chains. The Fourier transform infra‐red (FTIR) spectroscopy of ABPBI and the acid‐doped composites show all the relevant peaks corresponding to CC, CN stretching, and phosphoric acid/phosphates, confirming the formation of ABPBI and doping with PA. The proton conductivity of the membranes is estimated from electrochemical impedance spectroscopy (EIS). To establish the effect of change in crystallinity on relaxations and proton conductivity, the undoped and PA‐doped membranes are characterized using thermogravimetric analysis and in situ XRD at high temperatures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44867.
Conjoined twins: From conception to separation, a review
Authors: Mian Asma , Gabra Nader Ishak , Sharma Tanuj , Topale Nitsa , Gielecki Jerzy , Tubbs R. Shane , Loukas Marios
Published: February 2017

Conjoined twins are suggested to result from aberrant embryogenesis. The two main theories proposed to explain the phenomena are fission and fusion. The incidence rate is 1 in 50,000 births; however, since about 60% of the cases are stillborn, the true incidence is approximated at 1 in 200,000. There is a higher predisposition towards female than male gender with a ratio of 3:1. Conjoined twins are classified based upon the site of attachment. The extent of organ sharing, especially the heart, determines the possibility and prognosis of a separation procedure. Meticulous preoperative evaluation, planning, and preparedness of the team are crucial for a successful separation. Separation of conjoined twins poses several technical, legal, and ethical issues. Clin. Anat. 30:385–396, 2017. © 2017 Wiley Periodicals, Inc.
A reassessment of cervical surface anatomy via CT scan in an adult population
Authors: Shen Xin‐Hua , Xue Hua‐Dan , Chen Yu , Wang Man , Mirjalili S. Ali , Zhang Zhu‐Hua , Ma Chao
Published: February 2017

Surface landmarks in the neck are important for orientations of cervical glands, arteries, veins, nerves, and vertebrae. Recent research suggests some orientations are not correct. What are the cervical landmark orientations in the Chinese population? In this study, two essential cervical anatomy planes, the thyroid cartilage and C7 planes, were assessed in living adult Chinese subjects using computed tomography (CT), and the hyoid, carotid bifurcation, cricoid cartilage, thyroid arteries, and vertebral artery were simultaneously positioned. After excluding patients with distorting pathology, a total of 108 cervical CT scans were examined. The thyroid cartilage plane commonly passed through the C5 (in males) or C4 (in females) vertebral level. The carotid artery bifurcated most commonly at C3 (left) or C4 (right), more than 10 mm above the thyroid cartilage plane bilaterally in most cases. Orientation of the carotid bifurcation according to the body or greater horn of the hyoid was more accurate. The superior thyroid artery was found a finger‐breadth below the thyroid cartilage plane, and the inferior thyroid artery in the C7 plane. The inferior border of the cricoid cartilage was most often at C7 (in males) or C6 (in females). The vertebral artery entered the C6 transverse foramen in more than 80% of scans. This reassessment of cervical surface anatomy using modern imaging tools in vivo provides both qualitative and quantitative information for surgeons in clinical practice. Clin. Anat. 30:330–335, 2017. © 2017 Wiley Periodicals, Inc.
Lateral femoral cutaneous nerve transposition: Renaissance of an old concept in the light of new anatomy
Authors: Hanna Amgad S.
Published: February 2017

Meralgia paresthetica causes pain in the anterolateral thigh. Most surgical procedures involve nerve transection or decompression. We conducted a cadaveric study to determine the feasibility of lateral femoral cutaneous nerve (LFCN) transposition. In three cadavers, the LFCN was exposed in the thigh and retroperitoneum. The two layers of the LFCN canal superficial and deep to the nerve were opened. The nerve was then mobilized medially away from the ASIS, by cutting the septum medial to sartorius. It was possible to mobilize the nerve for 2 cm medial to the ASIS. The nerve acquired a much straighter course with less tension. A new technique of LFCN transposition is presented here as an anatomical feasibility study. The surgical technique is based on the new understanding of the LFCN canal. Clin. Anat. 30:409–412, 2017. © 2017 Wiley Periodicals, Inc.
Did a student's race‐discrimination complaint survive motion to dismiss?
Authors: Gelpi Aileen
Published: February 2017

Irving Salmeron, a Mexican‐American with a learning disability, was a student at the University of California, San Francisco School of Medicine.
Implementation of competency‐based curriculum: College of Philosophy, Universidad Nacional del Este, Paraguay
Authors: de las Nieves Pereira de Vallejos A. , Giménez Morel R.A. , Tusing J.
Published: February 2017

Background

Our current knowledge‐based society demands that new information be quickly incorporated into daily practices, thus leading to a better and more equitable society. For universities, this involves preparing students by linking the skills developed through a major's curriculum directly to their application in the labor market. From 2011 to 2013, the College of Philosophy of the Universidad Nacional del Este, Paraguay instituted a competency‐based curriculum model in the first 3 years of study for Education Science, Communication Science, Psychology, Mathematics, Letters, Philosophy and History majors.

Aims

The research team sought to evaluate faculty and student perceptions of the faculty's preparedness and ability to administer this new curriculum. Additionally, the impact on student learning and skill development was also assessed.

Methods

Both students and faculty completed a two‐part survey evaluating these topics and ten key respondents completed an additional in‐depth interview to provide a qualitative dimension to the research.

Results

The research demonstrated that the new curriculum is open, participatory, contextualized, process‐oriented, dynamic, interdisciplinary and adaptable to changes and advances in the pedagogical disciplines as well as in society at large.

Conclusions

This new approach demands a lot of commitment from all participants as feedback is used to revise the teaching–learning process and to reevaluate which skills and competencies are in highest demand in both local and global labor markets.
Manual thrombectomy efficiency in relationship to the area at risk in patients with myocardial infarction with TIMI 0‐1 coronary flow: Insights from an all comers registry
Authors: Luz André , Silveira Inês , Brochado Bruno , Rodrigues Patrícia , João Sousa Maria , Santos Raquel , Trêpa Maria , Santos Mário , Silveira João , Torres Severo , Leite‐Moreira Adelino F. , Carvalho Henrique
Published: February 2017

Objectives

To review the effectiveness of manual thrombectomy (MT) in a series of patients with ST‐elevation myocardial infarction (STEMI) exclusively presenting with TIMI 0‐1 flow undergoing percutaneous coronary intervention (PCI), in accordance to the angiographically estimated area at risk (AAR). Second, to assess major in‐hospital clinical events, emphasizing neurological outcomes.

Background

The routine utilization of MT in STEMI is not recommended. However, in recent trials, a significant proportion of patients had neither large thrombus burden nor a totally occluded coronary segment, neutralizing the expected benefits of MT. In addition, the efficiency of MT to remove thrombus has rarely been addressed. Finally, MT diminished distal embolization, which has been related to mortality.

Results

In 850 consecutive STEMI‐patients, MT was utilized in 525 (62%) and it was considered efficient (TIMI 2‐3 flow after MT) in 445 (85%). We found a significant interaction between the AAR and the effectiveness of MT to reduce infarct size (P‐interaction = 0.014). In patients having AAR ≥ 28% (n = 184), efficient MT conferred lesser infarct size compared to inefficient MT (Ln‐transformed peak CK): 7.87 ± 0.86 versus 8.36 ± 0.41 IU/L, P = 0.005, with no impact for AAR <28%. Clinical outcomes including stroke between MT and PCI‐only groups were not different.

Conclusion

In comparison with the group where MT was inefficient, efficient MT may modestly reduce final infarct size without a significant clinical benefit. In comparison with PCI‐only, no difference was found regarding stroke. © 2017 Wiley Periodicals, Inc.
Enhancing Photocatalytic Hydrogen Generation: the Impact of the Peripheral Ligands in Ru/Pd and Ru/Pt Complexes
Authors: Das Nivedita , Bindra Gurmeet Singh , Paul Avishek , Vos Johannes G. , Schulz Martin , Pryce Mary T.
Published: February 2017

The synthesis, photophysical properties and photocatalytic efficiency of a range of novel supramolecular assemblies of the type [Ru(dceb)2(μ‐bisbpy)MCl2][PF6]2 and [Ru(bpy)2(μ‐bisbpy)MCl2][PF6]2 (M=Pd or Pt, dceb=diethyl 2,2’‐bipyridine‐4,4’‐dicarboxylate, bpy=2,2’‐bipyridine and bisbpy=2,2’:5’,3’’:6’’,2’’’‐quaterpyridine) are reported. Photocatalytic hydrogen generation was dependent on the nature of the peripheral ligand, on the catalytic centre and on the amount of water present in the photocatalytic mixture. The best catalytic conditions were obtained with the dceb peripheral ligand (turnover numbers up to 513 after 18 h). The experimental data and DFT calculations on both the bpy‐ and dceb‐based compounds indicated that the peripheral dceb ligands participated in the photocatalytic process.
Synthesis of 2‐Aminofurans by Sequential [2+2] Cycloaddition–Nucleophilic Addition of 2‐Propyn‐1‐ols with Tetracyanoethylene and Amine‐Induced Transformation into 6‐Aminopentafulvenes
Authors: Shoji Taku , Nagai Daichi , Tanaka Miwa , Araki Takanori , Ohta Akira , Sekiguchi Ryuta , Ito Shunji , Mori Shigeki , Okujima Tetsuo
Published: February 2017

Synthesis of 2‐aminofuran derivatives with an azulene or N,N‐dimethylanilino substituent was established by the formal [2+2] cycloaddition–retroelectrocyclization of 3‐(1‐azulenyl or N,N‐dimethylanilino)‐2‐propyn‐1‐ols with tetracyanoethylene, followed by intramolecular nucleophilic addition to the initially formed tetracyanobutadiene moiety of the internal hydroxyl group that come from 2‐propyn‐1‐ol. The reaction proceeds under mild conditions with short reaction period. The products of the reaction are readily available through a simple purification procedure. 2‐Aminofuran derivatives obtained by this reaction could be converted into 6‐aminofulvene derivatives upon reaction with various amines. The structures of 2‐aminofuran and 6‐aminopentafulvene with a N,N‐dimethylanilino substituent were confirmed by single‐crystal X‐ray structural analysis.
Intermediates Stabilized by Tris(triazolylmethyl)amines in the CuAAC Reaction
Authors: Chen Haoqing , Cai Chengzhi , Li Siheng , Ma Yong , Luozhong Sijin , Zhu Zhiling
Published: February 2017

Tris(triazolylmethyl)amine ligands (TL) are widely used to accelerate the CuI‐catalyzed azide‐alkyne cycloaddition (CuAAC) reaction, but its mechanistic role remains unclear. Using electrospray ionization mass spectrometry, we detected for the first time the trinuclear TL‐CuI3‐acetylide and the dinuclear TL‐CuI2‐acetylide complexes in aqueous solution. The apparent second‐order rate constants of their reaction with an azide were 27 and 783 m−1⋅s−1 when the alkyne was tethered to TL. In the catalytic system without the tether, the rate constant increased to >146 m−1⋅s−1 for the TL‐CuI3‐acetylide, but dropped about 14‐fold to approximately 55 m−1⋅s−1 for the TL‐CuI2‐acetylide. The results indicated that TL accelerated the reaction by stabilizing the CuI2‐ and CuI3‐acetylide and their azide‐adduct intermediates, but this role is largely weakened by excess alkyne and other competing ligands under catalytic conditions.
Irreversible Cysteine‐Selective Protein Labeling Employing Modular Electrophilic Tetrafluoroethylation Reagents
Authors: Václavík Jiří , Zschoche Reinhard , Klimánková Iveta , Matoušek Václav , Beier Petr , Hilvert Donald , Togni Antonio
Published: February 2017

Fluoroalkylation reagents based on hypervalent iodine are widely used to transfer fluoroalkyl moieties to various nucleophiles. However, the transferred groups have so far been limited to simple structural motifs. We herein report a reagent featuring a secondary amine that can be converted to amide, sulfonamide, and tertiary amine derivatives in one step. The resulting reagents bear manifold functional groups, many of which would not be compatible with the original synthetic pathway. Exploiting this structural versatility and the known high reactivity toward thiols, the new‐generation reagents were used in bioconjugation with an artificial retro‐aldolase, containing an exposed cysteine and a reactive catalytic lysine. Whereas commercial reagents based on maleimide and iodoacetamide labeled both sites, the iodanes exclusively modified the cysteine residue. The study thus demonstrates that modular fluoroalkylation reagents can be used as tools for cysteine‐selective bioconjugation.
A deep learning based strategy for identifying and associating mitotic activity with gene expression derived risk categories in estrogen receptor positive breast cancers
Authors: Romo‐Bucheli David , Janowczyk Andrew , Gilmore Hannah , Romero Eduardo , Madabhushi Anant
Published: February 2017

The treatment and management of early stage estrogen receptor positive (ER+) breast cancer is hindered by the difficulty in identifying patients who require adjuvant chemotherapy in contrast to those that will respond to hormonal therapy. To distinguish between the more and less aggressive breast tumors, which is a fundamental criterion for the selection of an appropriate treatment plan, Oncotype DX (ODX) and other gene expression tests are typically employed. While informative, these gene expression tests are expensive, tissue destructive, and require specialized facilities. Bloom‐Richardson (BR) grade, the common scheme employed in breast cancer grading, has been shown to be correlated with the Oncotype DX risk score. Unfortunately, studies have also shown that the BR grade determined experiences notable inter‐observer variability. One of the constituent categories in BR grading is the mitotic index. The goal of this study was to develop a deep learning (DL) classifier to identify mitotic figures from whole slides images of ER+ breast cancer, the hypothesis being that the number of mitoses identified by the DL classifier would correlate with the corresponding Oncotype DX risk categories. The mitosis detector yielded an average F‐score of 0.556 in the AMIDA mitosis dataset using a 6‐fold validation setup. For a cohort of 174 whole slide images with early stage ER+ breast cancer for which the corresponding Oncotype DX score was available, the distributions of the number of mitoses identified by the DL classifier was found to be significantly different between the high vs low Oncotype DX risk groups (P < 0.01). Comparisons of other risk groups, using both ODX score and histological grade, were also found to present significantly different automated mitoses distributions. Additionally, a support vector machine classifier trained to separate low/high Oncotype DX risk categories using the mitotic count determined by the DL classifier yielded a 83.19% classification accuracy. © 2017 International Society for Advancement of Cytometry
Insights into the Coordination and Extraction of Yttrium(III) Ions with a Phenoxyacetic Acid Ionic‐Liquid Extractant
Authors: Guo Xiang‐Guang , Yang Ruo‐Ou , Gong Yu , Jiang Zheng , Dong Yamin , Sun Xiaoqi
Published: February 2017

Phenoxyacetic acid type extractants such as sec‐octylphenoxyacetic acid (CA‐12), sec‐nonylphenoxyacetic acid (CA‐100), and the resulting bifunctional ionic‐liquid extractants were developed to separate yttrium from heavy rare‐earth elements (REEs). To obtain information on the coordination chemistry of this type of bifunctional ionic‐liquid extractant, the CA‐12 analogue n‐octylphenoxyacetic acid (HOCTPOA) was synthesized, and its structure was characterized by single‐crystal X‐ray diffraction analysis. Then, a bifunctional ionic‐liquid extractant based on HOCTPOA, namely, [N1888][OCTPOA] (N1888 is methyltrioctylammonium) was synthesized. The study of the extraction of yttrium with [N1888][OCTPOA] in chloride media was conducted by IR spectroscopy, log D versus log C slope analysis, ESI‐MS, extended X‐ray absorption fine structure (EXAFS), and DFT studies. The EXAFS data indicate that a YIII extraction complex with phenoxyacetic acid formed. Three possible YIII coordination cations were calculated by the DFT method, and the obtained Y–O bond lengths were comparable to the results from EXAFS fitting. A possible structure for the overall extracted complex was proposed, and this knowledge should contribute to a better understanding of the extraction process with phenoxyacetate‐type bifunctional ionic liquids.
On the Mechanism of the Oxidative Cleavage of N‐Heterocyclic‐Carbene–Palladium Bonds with Iodine
Authors: Lee Eunsung , Lee Jaechul , Yandulov Dmitry V.
Published: February 2017

The excellent performance of N‐heterocyclic carbenes (NHCs) in various palladium‐catalyzed reactions has been explained by their strong donor character, which grants remarkable stability to palladium complexes often under extreme conditions and imparts adjustable steric demand. However, despite such a strong stability, the oxidative cleavage of palladium–carbene bonds by iodine was observed in NHC–palladium complexes. The oxidative cleavage of a palladium(II) iodide complex supported by the NHC with the smallest steric profile, 1,3‐dimethylimidazol‐2‐ylidene (IMe), is demonstrated here. The syntheses and characterization of various palladium –IMe complexes are reported along with a study of the mechanism of the oxidative cleavage of Pd–IMe bonds with iodine. Owing to the small steric profile of IMe, the important features of structure and bonding in these complexes are preserved, but reactivity with the relatively weak oxidant iodine is facilitated. Further computational mechanistic insights for this oxidative cleavage of the Pd–NHC bond were demonstrated, and both dissociative oxidative cleavage and metathesis of the Pd–NHC bond with iodine are feasible on the basis of DFT calculations.
Phosphoric Acid Catalyzed 1,2‐Rearrangements of 3‐Hydroxyindolenines to Indoxyls and 2‐Oxindoles: Reagent‐Controlled Regioselectivity Enabled by Dual Activation
Authors: Schendera Eva , Lerch Stephanie , von Drathen Thorsten , Unkel Lisa‐Natascha , Brasholz Malte
Published: February 2017

A common synthetic route to indoxyl and 2‐oxindole alkaloids utilizes the oxidation of indoles to 3‐hydroxyindolenines, followed by acid‐mediated 1,2‐rearrangement. However, controlling the regioselectivity is often challenging and there is an ongoing need for new reaction conditions allowing to steer product selectivity. We report herein that phosphoric acids are ideal organocatalysts for the highly regioselective 1,2‐rearrangement of 3‐hydroxyindolenines to 2‐oxindoles, with predictable product selectivity arising from an efficient dual activation mode.
Large grains matter: contrasting bed stability and morphodynamics during two nearly identical experiments
Authors: MacKenzie Lucy G. , Eaton Brett C.
Published: February 2017

While the stabilizing function of large grains in step‐pool streams has long been recognized, the role they play in gravel‐bed streams is less clear. Most researchers have ignored the role of large grains in gravel‐bed streams, and have assumed that the median bed surface size controls the erodibility of alluvial boundaries. The experiments presented herein challenge this convention. Two experiments were conducted that demonstrate the significant morphodynamic implications of a slight change to the coarse tail of the bed material. The two distributions had the same range of particle sizes, and nearly identical bulk d50 values (1.6 mm); however the d90 of experiment GSD1 was slightly finer (3.7 mm) than that for experiment GSD2 (3.9 mm). Transport rates during GSD1 were nearly four times greater than during GSD2 (even though the dimensionless shear stress was slightly lower), and the channel developed a sinuous pattern with well‐developed riffles, pools and bars. During GSD2 the initial rectangular channel remained virtually unchanged for the duration of the experiment. The relative stability of GSD2 seems to be associated with a slightly larger proportion of stable (large) grains on the bed surface: at the beginning of GSD1, 3.5% of the bed was immobile, while almost twice as much of it (6.1%) was immobile at the beginning of GSD2. The results demonstrate that the largest grains (not the median size) exert first‐order control on channel stability. Copyright © 2017 John Wiley & Sons, Ltd.
Sacred sites in north‐western Morocco – naturalness of their vegetation and conservation value for vulnerable plant species
Authors: Frosch Birgit , Jäckle Holger , Mhamdi Allal , El Kadmiri Ahmed Achhal , Rudner Michael , Deil Ulrich
Published: February 2017

The vegetation and flora of 86 sacred sites (surroundings of tombs of local saints, cemeteries) in NW Morocco was studied to assess their conservation value for undisturbed Mediterranean evergreen forests and vulnerable plants. Habitats were mapped, based on life form, maximum height and cover value, and classified according to naturalness. Vascular plants were classified according to pre‐defined risk factors like stenochory or grazing sensitivity. Naturalness index and refugial value were calculated for each site. Only 20% of the mapped site area was closed forest. On many places, human impact had created a vegetation mosaic. Most of the vulnerable plants were mesophilous forest species or grazing sensitive taxa. Endemic species occurred only rarely. The occurrence of vulnerable plants and the naturalness of the vegetation were positively correlated. Sacred site extension had no significant effect on the number of vulnerable species. Results indicate a limited relevance of sacred sites in northern Morocco for the protection of intact forests and vulnerable plants. However, these localities can play an important role as stepping stones in agricultural landscapes. They protect plants, sensitive to opening of the tree layer, to deforestation and to intense grazing. Certain formerly widespread forest communities survived exclusively on sacred sites.
Dynamically correct formulations of the linearised Navier–Stokes equations
Authors: Dellar O. J. , Jones B. Ll
Published: February 2017

Motivated by the need to efficiently obtain low‐order models of fluid flows around complex geometries for the purpose of feedback control system design, this paper considers the effect on system dynamics of basing plant models on different formulations of the linearised Navier–Stokes equations. We consider the dynamics of a single computational node formed by spatial discretisation of the governing equations in both primitive variables (momentum equation and continuity equation) and pressure Poisson equation formulations. This reveals fundamental numerical differences at the nodal level, whose effects on the system dynamics at the full system level are exemplified by considering the corresponding formulations of a two‐dimensional (2D) channel flow, subjected to a variety of different boundary conditions. Copyright © 2017 John Wiley & Sons, Ltd.
Inflammatory demyelination induces ependymal modifications concomitant to activation of adult (SVZ) stem cell proliferation
Authors: Pourabdolhossein Fereshteh , Gil‐Perotín Sara , Garcia‐Belda Paula , Dauphin Aurelien , Mozafari Sabah , Tepavcevic Vanja , Manuel Garcia Verdugo Jose , Baron‐Van Evercooren Anne
Published: February 2017

Ependymal cells (E1/E2) and ciliated B1cells confer a unique pinwheel architecture to the ventricular surface of the subventricular zone (SVZ), and their cilia act as sensors to ventricular changes during development and aging. While several studies showed that forebrain demyelination reactivates the SVZ triggering proliferation, ectopic migration, and oligodendrogenesis for myelin repair, the potential role of ciliated cells in this process was not investigated. Using conventional and lateral wall whole mount preparation immunohistochemistry in addition to electron microscopy in a forebrain‐targeted model of experimental autoimmune encephalomyelitis (tEAE), we show an early decrease in numbers of pinwheels, B1 cells, and E2 cells. These changes were transient and simultaneous to tEAE‐induced SVZ stem cell proliferation. The early drop in B1/E2 cell numbers was followed by B1/E2 cell recovery. While E1 cell division and ependymal ribbon disruption were never observed, E1 cells showed important morphological modifications reflected by their enlargement, extended cytoskeleton, and reinforced cell–cell junction complexes overtime, possibly reflecting protective mechanisms against ventricular insults. Finally, tEAE disrupted motile cilia planar cell polarity and cilia orientation in ependymal cells. Therefore, significant ventricular modifications in ciliated cells occur early in response to tEAE suggesting a role for these cells in SVZ stem cell signalling not only during development/aging but also during inflammatory demyelination. These observations may have major implications for understanding pathophysiology of and designing therapeutic approaches for inflammatory demyelinating diseases such as MS.
Hippocampal subfields at ultra high field MRI: An overview of segmentation and measurement methods
Authors: Giuliano Alessia , Donatelli Graziella , Cosottini Mirco , Tosetti Michela , Retico Alessandra , Fantacci Maria Evelina
Published: February 2017

The hippocampus is one of the most interesting and studied brain regions because of its involvement in memory functions and its vulnerability in pathological conditions, such as neurodegenerative processes. In the recent years, the increasing availability of Magnetic Resonance Imaging (MRI) scanners that operate at ultra‐high field (UHF), that is, with static magnetic field strength ≥7T, has opened new research perspectives. Compared to conventional high‐field scanners, these systems can provide new contrasts, increased signal‐to‐noise ratio and higher spatial resolution, thus they may improve the visualization of very small structures of the brain, such as the hippocampal subfields. Studying the morphometry of the hippocampus is crucial in neuroimaging research because changes in volume and thickness of hippocampal subregions may be relevant in the early assessment of pathological cognitive decline and Alzheimer's Disease (AD). The present review provides an overview of the manual, semi‐automated and fully automated methods that allow the assessment of hippocampal subfield morphometry at UHF MRI, focusing on the different hippocampal segmentation produced. © 2017 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Histamine facilitates GABAergic transmission in the rat entorhinal cortex: Roles of H1 and H2 receptors, Na+‐permeable cation channels, and inward rectifier K+ channels
Authors: Cilz Nicholas I. , Lei Saobo
Published: February 2017

In the brain, histamine (HA) serves as a neuromodulator and a neurotransmitter released from the tuberomammillary nucleus (TMN). HA is involved in wakefulness, thermoregulation, energy homeostasis, nociception, and learning and memory. The medial entorhinal cortex (MEC) receives inputs from the TMN and expresses HA receptors (H1, H2, and H3). We investigated the effects of HA on GABAergic transmission in the MEC and found that HA significantly increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) with an EC50 of 1.3 µM, but failed to significantly alter sIPSC amplitude. HA‐induced increases in sIPSC frequency were sensitive to tetrodotoxin (TTX), required extracellular Ca2+, and persisted when GDP‐β‐S, a G‐protein inactivator, was applied postsynaptically via the recording pipettes, indicating that HA increased GABA release by facilitating the excitability of GABAergic interneurons in the MEC. Recordings from local MEC interneurons revealed that HA significantly increased their excitability as determined by membrane depolarization, generation of an inward current at −65 mV, and augmentation of action potential firing frequency. Both H1 and H2 receptors were involved in HA‐induced increases in sIPSCs and interneuron excitability. Immunohistochemical staining showed that both H1 and H2 receptors are expressed on GABAergic interneurons in the MEC. HA‐induced depolarization of interneurons involved a mixed ionic mechanism including activation of a Na+‐permeable cation channel and inhibition of a cesium‐sensitive inward rectifier K+ channel, although HA also inhibited the delayed rectifier K+ channels. Our results may provide a cellular mechanism, at least partially, to explain the roles of HA in the brain. © 2017 Wiley Periodicals, Inc.