bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre-LGM Northern Hemisphere ice sheet topography
Authors: Kleman J. , Fastook J. , Ebert K. , Nilsson J. , Caballero R.
Published: October 2013

Abstract. We here reconstruct the paleotopography of Northern Hemisphere ice sheets during the glacial maxima of marine isotope stages (MIS) 5b and 4.We employ a combined approach, blending geologically based reconstruction and numerical modeling, to arrive at probable ice sheet extents and topographies for each of these two time slices. For a physically based 3-D calculation based on geologically derived 2-D constraints, we use the University of Maine Ice Sheet Model (UMISM) to calculate ice sheet thickness and topography. The approach and ice sheet modeling strategy is designed to provide robust data sets of sufficient resolution for atmospheric circulation experiments for these previously elusive time periods. Two tunable parameters, a temperature scaling function applied to a spliced Vostok–GRIP record, and spatial adjustment of the climatic pole position, were employed iteratively to achieve a good fit to geological constraints where such were available. The model credibly reproduces the first-order pattern of size and location of geologically indicated ice sheets during marine isotope stages (MIS) 5b (86.2 kyr model age) and 4 (64 kyr model age). From the interglacial state of two north–south obstacles to atmospheric circulation (Rocky Mountains and Greenland), by MIS 5b the emergence of combined Quebec–central Arctic and Scandinavian–Barents-Kara ice sheets had increased the number of such highland obstacles to four. The number of major ice sheets remained constant through MIS 4, but the merging of the Cordilleran and the proto-Laurentide Ice Sheet produced a single continent-wide North American ice sheet at the LGM.
A seasonality trigger for carbon injection at the Paleocene-Eocene thermal maximum
Authors: Eldrett J. S. , Greenwood D. R. , Polling M. , Brinkhuis H. , Sluijs A.
Published: October 2013

Abstract. The Paleocene-Eocene thermal maximum (PETM) represents a ~170 kyr episode of anomalous global warmth ~56 Ma ago. The PETM is associated with rapid and massive injections of 13C-depleted carbon into the ocean-atmosphere system reflected as a prominent negative carbon isotope excursion (CIE) in sedimentary components. Earth's surface and deep ocean waters warmed by ~5 °C, of which part may have occurred prior to the CIE. However, few records document continental climatic trends and changes in seasonality have not been documented. Here we present the first high-resolution vegetation reconstructions for the PETM, based on bioclimatic analysis of terrestrially-derived spore and pollen assemblages preserved in an expanded section from the Central North Sea. Our data indicate reductions in boreal conifers and an increase in mesothermal to megathermal taxa, reflecting a shift towards wetter and warmer climate. We also record an increase in summer temperatures, greater in magnitude than the rise in mean annual temperature changes. Within the CIE, vegetation varies significantly with initial increases in epiphytic and climbing ferns, and development of extensive wetlands, followed by abundance of Carya spp. indicative of broadleaf forest colonization. Critically, the change in vegetation we report occurs prior to the CIE, and is concomitant with anomalous marine ecological change, as represented by the occurrence of Apectodinium augustum. This suggests that amplifications of seasonal extremes triggered carbon injection.
Comment on "Polynomial cointegration tests of anthropogenic impact on global warming" by Beenstock et al. (2012) – some hazards in econometric modelling of climate change
Authors: Pretis F. , Hendry D. F.
Published: October 2013

Abstract. We outline six important hazards that can be encountered in econometric modelling of time-series data, and apply that analysis to demonstrate errors in the empirical modelling of climate data in Beenstock et al. (2012). We show that the claim made in Beenstock et al. (2012) as to the different degrees of integrability of CO2 and temperature is incorrect. In particular, the level of integration is not constant and not intrinsic to the process. Further, we illustrate that the measure of anthropogenic forcing in Beenstock et al. (2012), a constructed "anthropogenic anomaly", is not appropriate regardless of the time-series properties of the data.
Testing the realism of a topography driven model (FLEX-Topo) in the nested catchments of the Upper Heihe, China
Authors: Gao H. , Hrachowitz M. , Fenicia F. , Gharari S. , Savenije H. H. G.
Published: October 2013

Abstract. Although elevation data is globally available, and used in many existing hydrological models, its information content is still poorly understood and under-exploited. Topography is closely related to geology, soil, climate and land cover. As a result, it may reflect the dominant hydrological processes in a catchment. In this study, we evaluated this hypothesis through three progressively more complex conceptual rainfall-runoff models. The first model (FLEXL) is lumped, and it does not make use of elevation data. The second model (FLEXD) is semi-distributed. It also does not make use of elevation data, but it accounts for input spatial variability. The third model (FLEXT), also semi-distributed, makes explicit use of topography information. The structure of FLEXT consists of four parallel components representing the distinct hydrological function of different landscape elements. These elements were determined based on a topography based landscape classification approach. All models were calibrated and validated at the catchment outlet. Additionally, the models were evaluated at two nested sub-catchments. FLEXT, performs better than the other models in the nested sub-catchment validation and it is therefore better transferable. This supports the following hypotheses: (1) topography can be used as an integrated indicator to distinguish landscape elements with different hydrological function; (2) the model structure of FLEXT is much better equipped to represent hydrological signatures than a lumped or semi-distributed model, and hence has a more realistic model structure and parameterization; (3) the wetland/terrace and grassland hillslope landscape elements of the Upper Heihe contribute the main part of the fast runoff while the bare soil/rock landscape provides the main contribution to the groundwater. Most of the precipitation on the forested hillslopes is evaporated, thus generating relatively little runoff.
Combining earthquakes and GPS data to estimate the probability of future earthquakes with magnitude Mw ≥ 6.0
Authors: Chen K.-P. , Tsai Y.-B. , Chang W.-Y.
Published: October 2013

Abstract. According to Wyss et al. (2000) result indicates that future main earthquakes can be expected along zones characterized by low b values. In this study we combine Benioff strain with global positioning system (GPS) data to estimate the probability of future Mw ≥ 6.0 earthquakes for a grid covering Taiwan. An approach similar to the maximum likelihood method was used to estimate Gutenberg–Richter parameters a and b. The two parameters were then used to estimate the probability of simulating future earthquakes of Mw ≥ 6.0 for each of the 391 grids (grid interval = 0.1°) covering Taiwan. The method shows a high probability of earthquakes in western Taiwan along a zone that extends from Taichung southward to Nantou, Chiayi, Tainan and Kaohsiung. In eastern Taiwan, there also exists a high probability zone from Ilan southward to Hualian and Taitung. These zones are characterized by high earthquake entropy, high maximum shear strain rates, and paths of low b values. A relation between entropy and maximum shear strain rate is also obtained. It indicates that the maximum shear strain rate is about 4.0 times the entropy. The results of this study should be of interest to city planners, especially those concerned with earthquake preparedness. And providing the earthquake insurers to draw up the basic premium.
Hindcasting to measure ice sheet model sensitivity to initial states
Authors: Aschwanden A. , Aðalgeirsdóttir G. , Khroulev C.
Published: October 2013

Abstract. Validation is a critical component of model development, yet notoriously challenging in ice sheet modeling. Here we evaluate how an ice sheet system model responds to a given forcing. We show that hindcasting, i.e. forcing a model with known or closely estimated inputs for past events to see how well the output matches observations, is a viable method of assessing model performance. By simulating the recent past of Greenland, and comparing to observations of ice thickness, ice discharge, surface speeds, mass loss and surface elevation changes for validation, we find that the short term model response is strongly influenced by the initial state. We show that the thermal and dynamical states (i.e. the distribution of internal energy and momentum) can be misrepresented despite a good agreement with some observations, stressing the importance of using multiple observations. In particular we identify rates of change of spatially dense observations as preferred validation metrics. Hindcasting enables a qualitative assessment of model performance relative to observed rates of change. It thereby reduces the number of admissible initial states more rigorously than validation efforts that do not take advantage of observed rates of change.
Geologic sequestration of carbon dioxide: Implications for public water systems
Authors: Drago Joseph A. , Carpenter Adam T.
Published: October 2013

Underground sources of drinking water must be protected when geologic sequestration of carbon dioxide is used to mitigate greenhouse gas emissions.
San Francisco's race against time: Should other US cities start running?
Authors: Labonte Julie L.
Published: October 2013

To mitigate what undoubtedly would be severe water infrastructure damage from an earthquake of magnitude 6.7 or greater (the “Big One”), the San Francisco Bay Area has embarked on a monumental upgrade to its Hetch Hetchy Regional Water System, and invites other communities to learn from its experiences.
Climate change, extreme weather, and water utilities: Preparing for the new normal
Authors: Renner Rob
Published: October 2013

The effects of climate change on water utilities will be myriad and are expected to create significant challenges for utilities as they make long‐term plans for how to maintain adequate water supplies and quality into the future.
An evaluation of the accuracy of on‐line THM monitoring
Authors: Saini Harmesh , West Michael , Wang Qin , Garvey Jim , Mui Rudy
Published: October 2013

This study shows that the performance of an on‐line, automated trihalomethane monitor is as accurate and precise as off‐line commercial laboratories.
Urban Growth and Water Supply in Jorhat, India
Authors: Bhuyan Mayurakshi , Husain Zahid
Published: October 2013

This study focuses on urban growth in Jorhat, Assam, India, and its effect on the inefficient and insufficient water supply there. The results of the research highlight the various water supply systems of Jorhat and explore the possibility of tapping water sources through different means. The article also discusses the role of the various sources in providing domestic water to the citizens of Jorhat and the gap between water supply and demand.
Constructing the Monk: Francis Poulenc and the Post-War Context
Authors: Moore Christopher
Published: October 2013

Following the Second World War Francis Poulenc took a keen interest in the music of the French avant-garde and was compelled to react in both his music and his writings to the aesthetic and technical experiments of the younger generation. Although the music of composers like Olivier Messiaen and Pierre Boulez did not elicit a profound change on the substance of Poulenc’s compositional language, he did grow to the realization that the style he had embraced during the interwar period—one generally described as light-hearted and ironic—had become largely out of sync with new critical trends and concerns. Poulenc’s self-conscious aim to assert a personal form of “seriousness” in his works—one constructed with recourse to religiosity, stylistic homogeneity and the ostensibly concomitant values of sincerity and authenticity—formed the backbone of a new tone and persona that emerged following the war and which inflected his entire body of work up to his death in 1963. Poulenc’s desire to reinvent himself during this period forces us to re-examine his works, writings, and elements of his biography for the way in which they were constructed as a means of facilitating the discursive emergence of this new, more “serious,” persona.
Reliability and Availability of the Vessel Traffic Management and Information Systems
Authors: Ristov Pančo , Komadina Pavao , Tomas Vinko
Published: October 2013

This paper presents an approach to the reliability and availability of Vessel Traffic Management and Information Systems through the analysis of hardware, software and human reliability. The paper analyzes the critical subsystems and modules on the basis of the reliability theory, in order to achieve and ensure the availability of systems, i.e. to increase the safety of maritime traffic and the protection of the sea and marine environment. The paper discusses some of the techniques and mechanisms of hardware and software redundancy, as well as the activities that result in increasing the reliability of man.
Utility and Applications of Orthotopic Models of Human Non‐Small Cell Lung Cancer (NSCLC) for the Evaluation of Novel and Emerging Cancer Therapeutics
Authors: Justilien Verline , Fields Alan P.
Published: October 2013

Lung cancer is a leading cause of cancer deaths worldwide. Despite advances in chemotherapy, radiation therapy, and surgery, lung cancer continues to have a low 5‐year survival rate, highlighting a dire need for more effective means of prevention, diagnosis, prognosis, and treatment. Mouse models that recapitulate the clinical features of advanced human lung cancer are critical for testing novel therapeutic approaches. This unit describes a highly reproducible, easy‐to‐establish orthotopic murine model of lung cancer, provides methods for in vivo imaging and monitoring of tumor growth, and discusses the usefulness of this model for translational lung cancer research and the development of therapeutic strategies. Curr. Protoc. Pharmacol. 62:14.27.1‐14.27.17. © 2013 by John Wiley & Sons, Inc.
VIC+ for water‐limited conditions: A study of biological and hydrological processes and their interactions in soil‐plant‐atmosphere continuum
Authors: Luo Xiangyu , Liang Xu , McCarthy Heather R.
Published: October 2013

The Three‐Layer Variable Infiltration Capacity (VIC‐3L) land surface model is extended to include biological and hydrological processes important to water, energy, and carbon budgets under water‐limited climatic conditions: (1) movement of soil water from wet to dry regions through hydraulic redistribution (HR); (2) groundwater dynamics; (3) plant water storage; and (4) photosynthetic process. HR is represented with a process‐based scheme and the interaction between HR and groundwater dynamics is explicitly considered. The impact of frozen soil on HR in the cold season is also represented. Transpiration is calculated by combining an Ohm's law analogy, where flow from the soil to leaves is buffered by plant water storage, with the Penman‐Monteith method, where stomatal conductance is linked with photosynthesis. In this extended model (referred to as VIC+), water flow in plants and in the unsaturated and saturated zones, transpiration and photosynthesis are closely coupled, and multiple constraints are simultaneously applied to the transpiration process. VIC+ is evaluated with an analytical solution under simple conditions and with observed data at two AmeriFlux sites. Scenario simulations demonstrate the following results: (1) HR has significant impacts on water, energy, and carbon budgets during the dry season; (2) Rise of groundwater table, increase of root depth, HR, and plant water storage are favorable to dry‐season latent heat flux; (3) Plant water storage can weaken the intensity of upward HR; (4) Frozen soil can restrict downward HR in the wet winter and reduce the soil water reserves for the dry season.
How are terrestrial gamma ray flashes produced in thunderstorms?
Authors: Balcerak Ernie
Published: October 2013

Terrestrial gamma ray flashes (TGFs) are intense bursts of gamma rays that originate in thunderstorms and last from a few tens of microseconds to a few milliseconds. First observed in the early 1990s, TGFs are the highest‐energy natural phenomenon originating within Earth's atmosphere.
Effects of plume‐scale versus grid‐scale treatment of aircraft exhaust photochemistry
Authors: Cameron Mary A. , Jacobson Mark Z. , Naiman Alexander D. , Lele Sanjiva K.
Published: October 2013

This is a study to examine the impact of modeling photochemistry from aircraft emissions in an expanding plume versus at the grid scale in an atmospheric model. Differences in model treatments for a single flight occurred at all altitudes during takeoff, cruise, and landing. After 10 h, the plume treatment decreased grid‐scale ozone production by 33%, methane destruction by 30%, and carbon monoxide destruction by 32% at cruise altitude compared with the grid‐scale treatment. The plume treatment changed the odd nitrogen partitioning by ~10%. For multiple overlapping flights at cruise altitude, final ozone, methane, and carbon monoxide perturbations decreased by 77, 68, and 74%, respectively, compared with the grid‐scale treatment. Enhanced mixing with ambient air reduced the plume‐scale and grid‐scale differences. The persistent differences in photochemical activity indicate that individual plume treatment should be incorporated into 3‐D modeling studies.
On the relationship between lightning peak current and Early VLF perturbations
Authors: Salut M. M. , Cohen M. B. , Ali M. A. M. , Graf K. L. , Cotts B. R. T. , Kumar Sushil
Published: October 2013

Lightning strokes are known to cause direct heating and ionization of the D region, some of which are detected via scattering of VLF transmitter signals and are known as Early VLF events. The disturbed ionosphere typically recovers in many tens of seconds. New experimental evidence is presented demonstrating that the scattering pattern and onset amplitude of Early VLF events are strongly related to both the magnitude and polarity of causative lightning peak current. Observations of Early VLF events at nine Stanford VLF receiver sites across the continental United States are combined with lightning geolocation data from the National Lightning Detection Network (NLDN). During January and March 2011, NLDN recorded 7769 intense lightning discharges with high peak currents (>100 kA) generating 1250 detected Early VLF events. We show that the size of the scattered field due to the ionospheric disturbance increases with the peak current intensity of the causative lightning discharge. The most intense peak currents of >+200 and <−250 kA disturb VLF transmitter signals as far as ∼400 km away from the lightning stroke. Early VLF event detection probability also increases rapidly with peak current intensity. On the other hand, the observed VLF amplitude change is not significantly dependent on the peak current intensity. Stroke polarity is also important, with positive strokes being ∼5 times more likely to generate Early VLF disturbances than negative strokes of the same intensity. Intense positive cloud‐to‐ground lightning discharges, especially when occurring over the sea, are also more likely to produce Early VLF events with long recovery (many minutes).
Large lunar tidal effects in the equatorial electrojet during northern winter and its relation to stratospheric sudden warming events
Authors: Yamazaki Yosuke
Published: October 2013

It has been known for many decades that lunar tidal effects in the equatorial electrojet are greatest during northern winter; the mechanism of which has never been identified. Recent findings of the lunar tidal amplification during stratospheric sudden warming (SSW) events raise the question: To what extent do SSWs contribute to the large lunar tide during northern winter? We use ground magnetometer data at Addis Ababa for the years 1958–2007 to determine the average M2 lunar tide in the equatorial electrojet at different seasons. When all the data are included, the amplitude of the lunar tide is largest during northern winter. However, when only the data for non‐SSW winters are used, the amplitude during northern winter is not significantly larger than during other seasons. The M2 amplitude during SSW events is approximately 3 times as large as that for non‐SSW winters, and it considerably increases the amplitude of the average lunar tide during northern winter. The M2 phase is not significantly affected by SSW events. These results indicate that the occurrence of SSW events significantly modulates the seasonal pattern of lunar tidal effects on the ionosphere.
Late‐time drainage from a sloping Boussinesq aquifer
Authors: Bogaart Patrick W. , Rupp David E. , Selker John S. , van der Velde Ype
Published: October 2013

Numerical solutions to the nonlinear Boussinesq equation, applied to a steeply sloping aquifer and assuming uniform hydraulic conductivity, indicate that late‐time recession discharge decreases nearly linearly in time. When recession discharge is characterized by −dQ/dt = aQb, this is equivalent to constant dQ/dt or b = 0. This result suggests that a previously reported exponential decrease with time (b = 1) of modeled recession discharge from a similar sloping aquifer represented by the same equation appears to be an artifact of the numerical solution scheme and its interpretation. Because the linearly decreasing recession discharge (b = 0) is not known from field studies, these findings challenge the application of a nonlinear Boussinesq framework assuming uniform conductivity and geometric similarity to infer hydraulic properties of sloping aquifers from observations of streamflow. This finding also questions the validity of the physical interpretation of the exponential decline in late time resulting from the commonly used linearized form of the Boussinesq equation, opposed to the full nonlinear equation, when applied under these conditions. For this reason, application of the linearized equation to infer hydraulic properties of sloping aquifers is also challenged, even if the observed recession is consistent with that of the linearized Boussinesq equation.
Wood dispersal in braided streams: Results from physical modeling
Authors: Welber Matilde , Bertoldi Walter , Tubino Marco
Published: October 2013

Wood is a key feature of riverine systems, playing a significant role in their morphodynamics and ecology. Wood dynamics have been widely investigated in single‐thread streams, but limited information is available about wood transport and deposition in large multithread rivers. In this work, we used a large (3 × 25 m) physical model to provide a quantitative description of wood dispersal processes in braided systems. Deposition patterns were characterized in terms of downstream distribution and accumulation size and linked to wood piece properties (diameter, length, and presence of a rootwad) and flow stage. Statistical analysis of observed wood patterns showed that relative log diameter strongly reduces wood mobility, with travel distance dropping for diameters exceeding 50% of median channel depth. Wood tended to form small, sparse accumulations, with large log jams occurring for large log length, complex piece shape, and moderate flow discharge. Flow stage had a dual effect on mobility as both channel conveyance and the availability of retentive sites increased with discharge for the tested range of flow conditions. Additionally, wood deposition was strongly linked to bed morphology. In particular, 40–60% of transported wood was stored at bar apex, with more than 30% of wood deposited on the first bar downstream of the input point, highlighting the crucial role of local‐scale morphology in wood dispersal.
Isolation of Human Melanoma Stem Cells Using ALDH as a Marker
Authors: Luo Yuchun , Nguyen Nicholas , Fujita Mayumi
Published: October 2013

This unit describes a protocol for establishing a patient‐derived tumor xenograft model (PDTX model) of human melanoma and isolating human melanoma stem cells from human melanoma specimens using aldehyde dehydrogenase (ALDH) as a marker. One major limitation of analyzing a small fraction of cancer stem cells from patient tumor samples is that substantial quantities of fresh tumor tissues are not available. To overcome this challenge, we have established a PDTX model of human melanoma. In this model, human tumor tissues obtained from melanoma patients are dissected into small pieces and subsequently implanted into immunocompromised mice. The PDTX tumors retain fundamental genotypic and phenotypic features of the original tumors and are suitable for further biological analyses. Using the PDTX model, we have analyzed ALDH‐labeled human melanoma stem cells. This unit will describe how to establish a PDTX model using human tumor samples. We will also describe how to isolate and analyze ALDH‐labeled human melanoma stem cells using this model. Curr. Protoc. Stem Cell Biol. 26:3.8.1‐3.8.10. © 2013 by John Wiley & Sons, Inc.
Laboratory Growth and Maintenance of Streptococcus pyogenes (The Group A Streptococcus, GAS)
Authors: Gera Kanika , McIver Kevin S.
Published: October 2013

Streptococcus pyogenes is a Gram‐positive bacterium that strictly infects humans. It is the causative agent of a broad spectrum of diseases accounting for millions of infections and at least 517,000 deaths each year worldwide. It is a nutritionally fastidious organism that ferments sugars to produce lactic acid and has strict requirements for growth. To aid in the study of this organism, this unit describes the growth and maintenance of S. pyogenes. Curr. Protoc. Microbiol. 30:9D.2.1‐9D.2.13. © 2013 by John Wiley & Sons, Inc.
25th Anniversary Article: Progress in Chemistry and Applications of Functional Indigos for Organic Electronics
Authors: Głowacki Eric Daniel , Voss Gundula , Sariciftci Niyazi Serdar
Published: October 2013

Indigo and its derivatives are dyes and pigments with a long and distinguished history in organic chemistry. Recently, applications of this ‘old’ structure as a functional organic building block for organic electronics applications have renewed interest in these molecules and their remarkable chemical and physical properties. Natural‐origin indigos have been processed in fully bio‐compatible field effect transistors, operating with ambipolar mobilities up to 0.5 cm2/Vs and air‐stability. The synthetic derivative isoindigo has emerged as one of the most successful building‐blocks for semiconducting polymers for plastic solar cells with efficiencies > 5%. Another isomer of indigo, epindolidione, has also been shown to be one of the best reported organic transistor materials in terms of mobility (∼2 cm2/Vs) and stability. This progress report aims to review very recent applications of indigoids in organic electronics, but especially to logically bridge together the hereto independent research directions on indigo, isoindigo, and other materials inspired by historical dye chemistry: a field which was the root of the development of modern chemistry in the first place.
Toward an integrated software platform for systems pharmacology
Authors: Ghosh Samik , Matsuoka Yukiko , Asai Yoshiyuki , Hsin Kun‐Yi , Kitano Hiroaki
Published: October 2013

Understanding complex biological systems requires the extensive support of computational tools. This is particularly true for systems pharmacology, which aims to understand the action of drugs and their interactions in a systems context. Computational models play an important role as they can be viewed as an explicit representation of biological hypotheses to be tested. A series of software and data resources are used for model development, verification and exploration of the possible behaviors of biological systems using the model that may not be possible or not cost effective by experiments. Software platforms play a dominant role in creativity and productivity support and have transformed many industries, techniques that can be applied to biology as well. Establishing an integrated software platform will be the next important step in the field. © 2013 The Authors. Biopharmaceutics & Drug Disposition published by John Wiley & Sons, Ltd.
A p‐Quinodimethane‐Bridged Porphyrin Dimer
Authors: Zeng Wangdong , Ishida Masatoshi , Lee Sangsu , Sung Young Mo , Zeng Zebing , Ni Yong , Chi Chunyan , Kim Dongho , Wu Jishan
Published: October 2013

A p‐quinodimethane (p‐QDM)‐bridged porphyrin dimer 1 has been prepared for the first time. An unexpected Michael addition reaction took place when we attempted to synthesize compound 1 by reaction of the cross‐conjugated keto‐linked porphyrin dimers 8 a and 8 b with alkynyl/aryl Grignard reagents. Alternatively, compound 1 could be successfully prepared by intramolecular Friedel–Crafts alkylation of the diol‐linked porphyrin dimer 14 with concomitant oxidation in air. Compound 1 shows intense one‐photon absorption (OPA, λmax=955 nm, ε=45400 M−1 cm−1) and a large two‐photon absorption (TPA) cross‐section (σ(2)max=2080 GM at 1800 nm) in the near‐infrared (NIR) region due to its extended π‐conjugation and quinoidal character. It also exhibits a short singlet excited‐state lifetime of 25 ps. The cyclic voltammogram of 1 displays multiple redox waves with a small electrochemical energy gap of 0.86 eV. The ground‐state geometry, electronic structure, and optical properties of 1 have been further studied by density functional theory (DFT) calculations and compared with those of the keto‐linked dimer 8 b. This research has revealed that incorporation of a p‐QDM unit into the porphyrin framework had a significant impact on its optical and electronic properties, leading to a novel NIR OPA and TPA chromophore.
Fullerene‐sp2‐Iminosugar Balls as Multimodal Ligands for Lectins and Glycosidases: A Mechanistic Hypothesis for the Inhibitory Multivalent Effect
Authors: Rísquez‐Cuadro Rocío , García Fernández José M. , Nierengarten Jean‐François , Ortiz Mellet Carmen
Published: October 2013

Concerted functioning of lectins and carbohydrate‐processing enzymes, mainly glycosidases, is essential in maintaining life. It was commonly assumed that the mechanisms by which each class of protein recognizes their cognate sugar partners are intrinsically different: multivalency is a characteristic feature of carbohydrate–lectin interactions, whereas glycosidases bind to their substrates or substrate‐analogue inhibitors in monovalent form. Recent observations on the glycosidase inhibitory potential of multivalent glycomimetics have questioned this paradigm and led to postulate an inhibitory multivalent effect. Here the mechanisms at the origin of this phenomenon have been investigated. A D‐gluco‐configured sp2‐iminosugar glycomimetic motif, namely 1‐amino‐5N,6O‐oxomethylydenenojirimycin (1N‐ONJ), behaving, simultaneously, as a ligand of peanut agglutinin (PNA) lectin and as an inhibitor of several glycosidases, has been identified. Both the 1N‐ONJ–lectin‐ and 1N‐ONJ–glycosidase‐recognition processes have been found to be sensitive to multivalency, which has been exploited in the design of a lectin–glycosidase competitive assay to explore the implication of catalytic and non‐glycone sites in enzyme binding. A set of isotropic dodecavalent C60‐fullerene–sp2‐iminosugar balls incorporating matching or mismatching motifs towards several glycosidases (inhitopes) was synthesized for that purpose, thereby preventing differences in binding modes arising from orientational preferences. The data supports that: 1) multivalency allows modulating the affinity and selectivity of a given inhitope towards glycosidases; 2) multivalent presentation can switch on the inhibitory capacity for some inhitope–glycosidase pairs, and 3) interactions of the multivalent inhibitors with non‐glycone sites is critical for glycosidase recognition. The ensemble of results point to a shift in the binding mode on going from monovalent to multivalent systems: in the first case a typical ′′key–lock′′ model involving, essentially, the high‐affinity active site can be assumed, whereas in the second, a lectin‐like behavior implying low‐affinity non‐glycone sites probably operates. The differences in responsiveness to multivalency for different glycosidases can then be rationalized in terms of the structure and accessibility of the corresponding carbohydrate‐binding regions.
Vibrational Circular Dichroism Discrimination of Diastereomeric Cedranol Acetates
Authors: Gordillo‐Román Bárbara , Camacho‐Ruiz Jorge , Bucio María A. , Joseph‐Nathan Pedro
Published: October 2013

The reliability of vibrational circular dichroism (VCD) spectroscopy to discriminate four diastereomeric cedranol acetates 1, 2, 3, 4 by means of their absolute configuration is examined. The usage of CompareVOA software to quantify comparisons of the measured infrared (IR) and VCD spectra with the corresponding simulated spectra at the B3LYP/DGDZVP and B3PW91/DGDZVP levels of theory for each diastereomer enabled the B3PW91 functional to be qualified as superior to the B3LYP functional for vibrational calculations of 1, 2, 3, 4. Analogously, a set of quantitative VCD spectra cross‐comparisons of 1, 2, 3, 4 unambiguously distinguished the diastereomers using B3PW91 and failed using B3LYP. Remarkably, quantitative IR spectra cross‐comparisons of 1, 2, 3, 4 using B3PW91 or B3LYP functionals demonstrated that the achiral spectroscopic IR technique is not able to distinguish cedranol acetate diastereomers. VCD comparisons using anisotropy g‐factor values of bands in the 1550–950 cm‐1 region of the spectra were of aid to facilitate visual spectra matching for each diastereomer. Chirality 25:939‐951, 2013. © 2013 Wiley Periodicals, Inc.
Neurogenesis in the lamprey central nervous system following spinal cord transection
Authors: Zhang Guixin , Pizarro Ivonne Vidal , Swain Gary P. , Kang Shin H. , Selzer Michael E.
Published: October 2013

After spinal cord transection, lampreys recover functionally and axons regenerate. It is not known whether this is accompanied by neurogenesis. Previous studies suggested a baseline level of nonneuronal cell proliferation in the spinal cord and rhombencephalon (where most supraspinal projecting neurons are located). To determine whether cell proliferation increases after injury and whether this includes neurogenesis, larval lampreys were spinally transected and injected with 5‐bromo‐2&prime‐deoxyuridine (BrdU) at 0–3 weeks posttransection. Labeled cells were counted in the lesion site, within 0.5 mm rostral and caudal to the lesion, and in the rhombencephalon. One group of animals was processed in the winter and a second group was processed in the summer. The number of labeled cells was greater in winter than in summer. The lesion site had the most BrdU labeling at all times, correlating with an increase in the number of cells. In the adjacent spinal cord, the percentage of BrdU labeling was higher in the ependymal than in nonependymal regions. This was also true in the rhombencephalon but only in summer. In winter, BrdU labeling was seen primarily in the subventricular and peripheral zones. Some BrdU‐labeled cells were also double labeled by antibodies to glial‐specific (antikeratin) as well as neuron‐specific (anti‐Hu) antigens, indicating that both gliogenesis and neurogenesis occurred after spinal cord transection. However, the new neurons were restricted to the ependymal zone, were never labeled by antineurofilament antibodies, and never migrated away from the ependyma even at 5 weeks after BrdU injection. They would appear to be cerebrospinal fluid‐contacting neurons. J. Comp. Neurol. 522:1316–1332, 2014. © 2013 Wiley Periodicals, Inc.
SPICE modeling of nonlinear memristive behavior
Authors: Vourkas Ioannis , Batsos Athanasios , Sirakoulis Georgios Ch.
Published: October 2013

The recent discovery of the ‘modern’ memristor has drawn great attention of both academia and industry. Given their favorable performance merits, memristors are expected to play a fundamental role in electronic industry. Modeling of memristive devices is essential for circuit design, and a number of Simulation Program with Integrated Circuit Emphasis (SPICE) models have already been introduced. The common problem in most models is that there is no threshold consideration; hence, only a few address the nonlinear nature of the device. This paper aims to present a SPICE implementation of a threshold‐type switching model of a voltage‐controlled memristive device that attributes the switching effect to a tunneling distance modulation. Threshold‐type switching is closer to the actual behavior of most experimentally realizable memristive systems, and our modeling approach addresses the issue of programming thresholds. Both the netlist and the simple schematic are provided, thus making it easy to comprehend and ready to be used. Compared with other modeling solutions, it involves significantly low‐complexity operation under an unlimited set of frequencies, and its simulation results are in good qualitative and quantitative agreement with the theoretical formulation. The proposed model is used to simulate an antiserial memristive switch, proving that it can be efficiently introduced in complex memristive circuits. Copyright © 2013 John Wiley & Sons, Ltd.
The importance of selection at the level of the pair over 25 years in a natural population of birds
Authors: Björklund Mats , Gustafsson Lars
Published: October 2013

Knowledge of the pattern of selection in natural populations is fundamental for our understanding of the evolutionary process. Selection at higher levels has gained considerable theoretical support in recent years, and one possible level of selection is the breeding pair where fitness is a function of the pair and cannot be reduced to single individuals. We analyzed the importance of pair‐level selection over 25 years in a natural population of the collared flycatcher. Pair‐level selection was significant in five and probably in another 9 years. The relative importance of pair‐level selection varied over years and can have stronger or the same strength as directional selection. This means that selection can act on the combination of the breeding pair in addition to selection on each individual separately. Overall, the conservative estimates obtained here show that this is a potentially important form of selection.
One‐Pot Synthesis of Benzimidazo[1,2‐f]phenanthridines by Cascade Palladium‐Catalyzed N‐Arylation and Intramolecular C–H Coupling
Authors: Liu Jianming , Zhang Ningfei , Yue Yuanyuan , Liu Guihua , Liu Ren , Zhang Yuanli , Zhuo Kelei
Published: October 2013

An efficient protocol has been developed that uses sequential N‐arylation and intramolecular C–H coupling for the construction of azole‐fused phenanthridine heterocycle derivatives in good yields. This new method allows the one‐pot synthesis of polysubstituted complex molecules from readily available benzo[d]imidazoles and 1,2‐dibromobenzenes.
Micromachined silicon attenuated total reflectance infrared spectroscopy: An emerging detection method in micro/nanofluidics
Authors: Karabudak Engin
Published: October 2013

Microfluidics is an emerging field with various applications. In situ analysis of liquids inside microfluidic channels is an important research subject for any of these applications. On the other hand, attenuated total reflectance infrared spectroscopy (ATR‐IR) is a strong surface detection method. Recently, there have been various attempts to use ATR‐IR for detection of liquids inside microfluidic channels. Micromachined silicon ATR‐IR (μSi‐ATR‐IR) is an emerging analytical tool for micro/nanofluidics. This paper reviews μSi‐ATR‐IR micro/nanofluidics detection devices and discusses the application fields, capabilities, advantages, and disadvantages of the method.
Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis
Authors: Deeb Sami El , Wätzig Hermann , El‐Hady Deia Abd , Albishri Hassan M. , de Griend Cari Sänger‐van , Scriba Gerhard K. E.
Published: October 2013

Since the introduction about 30 years ago, CE techniques have gained a significant impact in pharmaceutical analysis. The present review covers recent advances and applications of CE for the analysis of pharmaceuticals. Both small molecules and biomolecules such as proteins are considered. The applications range from the determination of drug‐related substances to the analysis of counterions and the determination of physicochemical parameters. Furthermore, general considerations of CE methods in pharmaceutical analysis are described.
Design and validation of a thermoreversible material for percutaneous tissue hydrodissection
Authors: Johnson Alexander , Sprangers Anthony , Cassidy Patrick , Heyrman Sean , Hinshaw J. Louis , Lubner Meghan , Puccinelli John , Brace Chris
Published: October 2013

Interventional oncology procedures such as thermal ablation are becoming routine for many cancers. Hydrodissection—separating tissues with fluids—protects tissues near the treatment zone to improve ablation's safety and facilitate more aggressive treatments. However, currently used fluids such as normal saline and 5% dextrose in water (D5W) migrate in the peritoneum, reducing their protective efficacy. As a hydrodissection alternative, we investigated a thermoreversible poloxamer 407 (P407) solution. Such a material can be injected as a liquid which then forms a semi‐solid gel at body temperature without syneresis. The desired gelation temperature of 32°C was achieved with 15.4 wt/wt % P407. Viscosity analysis revealed the lowest viscosity and ideal injection point was at 14°C. Solution viscosity increased during gelation, to a peak of 65 kPa*s at 40°C. The electrical impedance of P407 was significantly greater than isotonic saline, but lower than D5W, indicating its potential for electrical protection. The P407 gel was similar to other hydrodissection fluids at ultrasound and CT imaging. Ex vivo liver ablations showed that P407 protects neighboring tissues, but may require a thicker barrier for comparable protection to D5W. Overall, we found that the P407 solution is a feasible alternative to traditional hydrodissection fluids and warrants additional study. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1400–1409, 2013.
Laser fabrication of porous silicon‐based platforms for cell culturing
Authors: Peláez Ramón‐J. , Afonso Carmen‐N. , Vega Fidel , Recio‐Sánchez Gonzalo , Torres‐Costa Vicente , Manso‐Silván Miguel , García‐Ruiz Josefa‐P. , Martín‐Palma Raúl‐J.
Published: October 2013

In this study, we explore the selective culturing of human mesenchymal stem cells (hMSCs) on Si‐based diffractive platforms. We demonstrate a single‐step and flexible method for producing platforms on nanostructured porous silicon (nanoPS) based on the use of single pulses of an excimer laser to expose phase masks. The resulting patterns are typically 1D patterns formed by fringes or 2D patterns formed by circles. They are formed by alternate regions of almost unmodified nanoPS and regions where the nanoPS surface has melted and transformed into Si nanoparticles. The patterns are produced in relatively large areas (a few square millimeters) and can have a wide range of periodicities and aspect ratios. Direct binding, that is, with no previous functionalization of the pattern, alignment, and active polarization of hMSCs are explored. The results show the preferential direct binding of the hMSCs along the transformed regions whenever their width compares with the dimensions of the cells and they escape from patterns for smaller widths suggesting that the selectivity can be tailored through the pattern period. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1463–1468, 2013.
Exploring Quality in Gradient Copolymers
Authors: Elsen Andrea M. , Li Yuanchao , Li Qiaoxi , Sheiko Sergei S. , Matyjaszewski Krzysztof
Published: October 2013

Quality of gradient copolymers is evaluated by atomic force microscopy (AFM) and correlated with molecular weight distribution (MWD) values. ARGET ATRP is employed with decreasing levels of catalyst concentrations to generate copolymers with increasing / values. The copolymers are transformed into molecular bottlebrushes to enable imaging and analysis of individual molecules by AFM. The average height (cross‐sectional) profile of all bottlebrushes agrees with the instantaneous composition (ICHEMA‐TMS) of the analogous copolymer backbone, as determined by 1H NMR. The copolymer synthesized with 500 ppm of catalyst exhibits more narrow distributions of both brush height and backbone length when analyzed as a bottlebrush by AFM. Correspondingly, the copolymers synthesized with lower catalyst concentrations yield bottlebrushes with broader height and length distribution. These results establish MWD values as an excellent trait to assess quality within gradient copolymers.

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Readiness redefined: A behavioral task during screening predicted 1‐year weight loss in the look AHEAD study
Authors: Tsai Adam G. , Fabricatore Anthony N. , Wadden Thomas A. , Higginbotham Allison J. , Anderson Andrea , Foreyt John , Hill James O. , Jeffery Robert W. , Gluck Marci E. , Lipkin Edward W. , Reeves Rebecca S. , Van Dorsten Brent
Published: October 2013

Objective

Predicting outcome in weight loss trials from baseline characteristics has proved difficult. Readiness to change is typically measured by self‐report.

Methods

Performance of a behavioral task, completion of food records, from the screening period in the Look AHEAD study (n = 549 at four clinical centers) was assessed. Completeness of records was measured by the number of words and Arabic numerals (numbers) recorded per day, the number of eating episodes per day, and days per week where physical activity was noted. The primary outcome was weight loss at one year.

Results

In univariable analysis, both the number of words recorded and the number of numbers recorded were associated with greater weight loss. In multivariable analysis, individuals who recorded 20‐26, 27‐33, and ≥34 words per day lost 9.12%, 11.40%, and 12.08% of initial weight, compared to 8.98% for individuals who recorded less than 20 words per day (P values of 0.87, 0.008, and <0.001, respectively, compared to <20 words per day).

Conclusions

Participants who kept more detailed food records at screening lost more weight after 1 year than individuals who kept sparser records. The use of objective behavioral screening tools may improve the assessment of weight loss readiness.