bluuebunny/crossref_metadata_2025_split huggingface dataset:
Creative patterns and stimulation in conceptual design
Authors: Jin Yan , Benami Oren 
Published: April 2010

AbstractConceptual design is a creative process. Designers create functions to satisfy customer needs and behaviors and forms to fulfill their functions. Although cognitive processes are at the center in developing new ideas, they are rarely taken into account in research and development of design support methods and systems. It is conceivable that if one understands how cognitive processes are stimulated to generate design ideas, then more effective methods and tools can be developed to support conceptual design. In this article, a cognitive model of conceptual design is developed to capture the relationships among design entities, design operations, and cognitive processes. A protocol analysis is performed to evaluate the model, and a cognitive experiment carried out to study the creative patterns and stimulating relationships. The results show that designers exhibit patterns of creative design behavior, and that these patterns can be captured and instilled into the design process to promote creativity.
Umbelliferae of Southern Africa: an introduction and annotated check-list
Authors: Burtt B.L. 
Published: April 2010

Nullam profecto plantarum familiam quam Umbelliferas, majoribus premi aut pluribus difficultatibus, nullam ad nostra usque tempora magis esse desertam atque confusam, ecquis negabit, qui vel nuperrimos plantarum indices cum rerum natura ipsa comparaverit?K. J. P. Sprengel (1813a).Truly, no family of plants is weighed down with greater or more numerous difficulties, none up to this time is so neglected and confused, as the Umbelliferae. Is there anyone, even one who has compared the very latest indexes of the plants with nature itself, who will deny this?Native genera of Umbelliferae recorded for southern Africa total 38, and 19 are endemic. Of these, 17 lack close allies either within the area or outside it, suggesting that southern Africa once had a much richer Umbelliferan flora than at present, and emphasizing the importance of the area in the history of the family. The native species number about 195. All names that have been used for southern African species are listed and cross-referenced to the recommended name, which is set out with full synonymy. Difficult problems are discussed in a series of Notes. There is a list of 20 new names (6 new species, 11 transfers and 3 replacement names). The introductory sections include notes on family classification and the phytogeography of the genera; there is a survey of characters useful in classification and particular attention is paid to studies carried out on the family in other areas. All work quoted is fully referenced. A key to the genera is provided.
ON PRODUCTS OF PSEUDO-ANOSOV MAPS AND DEHN TWISTS OF RIEMANN SURFACES WITH PUNCTURES
Authors: ZHANG C. 
Published: April 2010

AbstractLet S be a Riemann surface of type (p,n) with 3p+n>4 and n≥1. We investigate products of some pseudo-Anosov maps θ and Dehn twists tα on S, and prove that under certain conditions the products tkα∘θ are pseudo-Anosov for all integers k. We also give examples that show that tkα∘θ are not pseudo-Anosov for some integers k.
ON CARMICHAEL NUMBERS IN ARITHMETIC PROGRESSIONS
Authors: BANKS WILLIAM D. , POMERANCE CARL 
Published: April 2010

AbstractAssuming a conjecture intermediate in strength between one of Chowla and one of Heath-Brown on the least prime in a residue class, we show that for any coprime integers a and m≥1, there are infinitely many Carmichael numbers in the arithmetic progression a mod m.
Satellite Observations From the International Polar Year
Authors: Jezek Kenneth , Drinkwater Mark 
Published: April 2010

To realize the benefit of the growing number of international satellites to the scientific objectives of the 2007–2008 International Polar Year (IPY), the Global Interagency IPY Polar Snapshot Year (GIIPSY) was established in November 2005 to develop a consensus on polar science requirements and objectives for IPY that could best and perhaps only be met using the Earth‐observing satellites. Requirements focused on all aspects of the cryosphere and ranged from sea ice and ice sheets to permafrost and snow cover. Individual topics included how best to develop high‐resolution digital elevation models of outlet glaciers using stereo‐optical systems, measure ice sheet surface velocity using interferometric synthetic aperture radar (InSAR), and repeatedly measure sea ice motion using optical and microwave imaging instruments.Because of this foresight, several IPY science objectives were well met using satellite observations, allowing a wealth of valuable data to be collected on cryospheric processes (Figure 1). Further, the framework for coordinating these remote sensing efforts serves as a valuable model for future coordinated efforts to monitor cryospheric dynamics.
Hubble 3D: A Science and Hollywood Collaboration Made (Nearly) in Heaven
Authors: Showstack Randy 
Published: April 2010

Just 2 days after the 2010 Academy Awards® ceremony in early March bestowed Oscars® for motion picture achievements, NASA deputy administrator Lori Garver touted a new film about the Hubble Space Telescope, Hubble 3D, for best drama, special effects, screenplay, actors and actress, and director and producer. The 43‐minute IMAX and Warner Brothers Pictures production, which opened in theaters on 19 March, is an example of the ability of Hollywood and the science community to partner in providing a dynamic educational and entertaining product, according to a number of people associated with the film.Sharing the red carpet at the Smithsonian National Air and Space Museum in Washington, D.C., with astronauts and others to mark the world premiere, Garver said the film shows the drama of the astronauts' efforts to repair the telescope while traveling 17,000 miles per hour and performing grueling space walks (see Figure 1). “We have literally opened our eyes on the universe through this telescope,” she said. “This is a taxpayer‐funded agency, and we are giving back to the public the very story that they paid for.”
Vithanage Receives 2009 Natural Hazards Focus Group Award for Graduate Research
Authors: Anonymous  
Published: April 2010

Meththika Vithanage has been awarded the Natural Hazards Focus Group Award for Graduate Research, given annually to recent Ph.D. recipients for outstanding contributions to natural hazards research. Vithanage's thesis is entitled “Effect of tsunami on coastal aquifers: Field studies and tank experiments.” She was formally presented with the award at the Natural Hazards Focus Group reception during the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif.Vithanage received her B.S. in natural resources from Sabaragamuwa University of Sri Lanka in 2002 and an M.S. in environmental science from the University of Peradeniya, Sri Lanka, in 2005. In 2009, she attained a Ph.D. in hydrogeology under the supervision of Karsten Jensen and Peter Engesgaard in the Department of Geology and Geography at University of Copenhagen, Denmark.
Reconciling Differing Views of Tropical Pacific Climate Change
Authors: DiNezio Pedro , Clement Amy , Vecchi Gabriel 
Published: April 2010

Recent analyses of global warming projections simulated with global climate models (GCMs) suggest that the tropical Pacific does not become El Niño‐ or La Niña‐like in response to increased greenhouse gases (GHGs). Rather, the physical mechanisms that drive tropical Pacific climate change depart substantially from the El Niño‐Southern Oscillation (ENSO) analogy often invoked for interpreting future climate changes [e.g., Knutson and Manabe, 1995; Meehl and Washington, 1996; Cane et al., 1997; Collins et al., 2005; Meehl et al., 2007; Lu et al., 2008; Cox et al., 2004] and past climate changes [e.g. Lea et al., 2001; Koutavas et al., 2002]. This presents an opportunity for reconciling theory, models, and observations.An ENSO analogy typically is invoked for interpreting tropical Pacific climate change because if an external forcing introduces some east‐west asymmetry, this asymmetry can be amplified in the same way as interannual perturbations are, through the positive ocean‐atmosphere Bjerknes feedback. This then would lead to an altered mean state of the tropical Pacific resembling El Niño or La Niña [Dijkstra and Neelin, 1995]. For instance, the model projections used for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) anticipate tropical Pacific climate change in response to increased GHGs that has been described as El Niño—like [Meehl et al., 2007]. These models project robust enhanced equatorial warming [Liu et al., 2006; DiNezio et al., 2009] and a weakening of the overturning atmosphere circulation across the tropical Pacific, i.e., the Walker circulation [Vecchi and Soden, 2007], both of which occur during El Niño events. However, these experiments also show a shoaling and sharpening of the equatorial thermocline [Vecchi and Soden, 2007; DiNezio et al., 2009] (Figure 1a). This is in contrast to El Niño events, when the thermocline response is heavily dominated by a relaxed tilt (Figure 1b).
Volcanic vents found in deep Caribbean waters
Authors: Showstack Randy 
Published: April 2010

Scientists surveying the Cayman Trough in the Caribbean Sea have discovered the world's deepest undersea volcanic vents, or “black smokers,” the National Oceanography Center (NOC) in Southampton, UK, announced on 11 April. The vents were found at a depth of 5000 meters, about 800 meters deeper than any previously discovered.Jon Copley, a marine biologist at the University of Southampton's School of Ocean and Earth Science, said, “Seeing the world's deepest black‐smoker vents looming out of the darkness was awe‐inspiring.” Geochemist Doug Connelly of NOC, principal scientist of the expedition, noted, “We hope our discovery will yield new insights into biogeochemically important elements in one of the most extreme naturally occurring environments on our planet.” Researchers used an NOC‐developed Autosub6000 robot submarine, which was remotely controlled from the Royal Research Ship James Cook.
Updated International Geomagnetic Reference Field
Authors: Showstack Randy 
Published: April 2010

The latest release of International Geomagnetic Reference Field (IGRF‐11) was published online at the end of 2009. IGRF is a standard reference model of Earth's internal magnetic field. The reference field is typically updated every 5 years by an international team of geomagnetic field modelers working under the auspices of the International Association of Geomagnetism and Aeronomy and in collaboration with institutions collecting and disseminating magnetic field measurements from satellites and a worldwide network of ground‐based observatories.As with earlier versions of the reference field, IGRF‐11 provides a global picture of the past and present geomagnetic field as well as a linear prediction of field changes over the upcoming 5 years. IGRF is widely used in navigation and heading systems, geophysical surveying, and space weather modeling and prediction.
Recommendations for Interdisciplinary Study of Tipping Points in Natural and Social Systems
Authors: Jordan Teresa E. , Sala Osvaldo E. , Stafford Susan G. , Bubier Jill L. , Crittenden John C. , Cutter Susan L. , Kay Alan C. , Libecap Gary D. , Moore John C. , Rabalais Nancy N. , Shepherd J. Marshall , Travis Jospeh 
Published: April 2010

In September 2009, the U.S. National Science Foundation's (NSF) Advisory Committee for Environmental Research and Education (AC‐ERE) released “Transitions and Tipping Points in Complex Environmental Systems,” a report that advocates sweeping change in the way environmental research and education are sponsored and conducted. The conviction of the committee that physical and life scientists, engineers, educators, and social scientists must work collaboratively to understand the dynamics of complex environmental systems should resonate with AGU's membership.A major theme of the AC‐ERE report is that scientists need to understand environmental systems that, partly owing to human activity, may be approaching thresholds for irreversible change. This theme echoes sentiments expressed in the geosciences community, such as by Rockström et al. [2009], who estimate the magnitudes of thresholds for irreversible changes in nine key Earth subsystems and focus on how human activities have driven systems closer—or even past—some thresholds. The AC‐ERE report argues that understanding natural systems will require integrated research among geoscientists, social scientists, ecologists, and others.
Solute transporters and aquaporins are impaired in celiac disease
Authors: Laforenza Umberto , Miceli Emanuela , Gastaldi Giulia , Scaffino Manuela F. , Ventura Ulderico , Fontana Jacopo M. , Orsenigo Maria N. , Corazza Gino R. 
Published: April 2010

Background information. Celiac disease is a chronic inflammatory disorder of the small bowel induced in genetically susceptible subjects by gluten ingestion. Diarrhoea, weight loss and malabsorption represent the major clinical presentation of the disease. Here we examined the possible alteration in the expression and localization of water channels [AQPs (aquaporins)] and some solute transporters in duodenal mucosa of celiac disease patients. Duodenal biopsies from untreated celiacs, treated celiacs, healthy controls and disease controls were considered in the present study. The expressions of some AQPs and transporter mRNAs in human duodenal biopsies were determined by semi‐quantitative RT—PCR (reverse transcription PCR) and real‐time RT—PCR. The localization of AQPs 3, 7 and 10 and of SGLT1 (Na+/glucose co‐transporter 1), PEPT1 (H+/oligopeptide transporter 1) and NHE3 (Na+/H+ exchanger 3) was evaluated by immunohistochemistry.Results. AQPs 3, 7, 10 and 11, SGLT, PEPT and NHE, CFTR (cystic fibrosis transmembrane conductance regulator) and NKCC (Na‐K‐2Cl co‐transporter) mRNAs were expressed in duodenal biopsies of healthy controls, treated celiac patients and disease controls. The expression of transcripts was virtually absent in duodenal biopsies of untreated celiac disease patients except for CFTR and NKCC. In healthy controls, immunohistochemistry revealed a labelling in the apical membrane of surface epithelial cells of the duodenum. The immunolabelling was heavily reduced or absent in untreated celiac patients, while it was normal in patients consuming a gluten‐free diet for at least 12 months.Conclusions. Our results indicate that the main routes for water and solute absorption are deficient in celiac disease and may play a role in the onset of malabsorption symptoms.
Identification of the structural motif responsible for trimeric assembly of the C-terminal regulatory domains of polycystin channels PKD2L1 and PKD2
Authors: Molland Katrina L. , Narayanan Anoop , Burgner John W. , Yernool Dinesh A. 
Published: April 2010

Polycystin 2-type cation channels PKD2 and PKD2L1 interact with polycystin 1-type proteins PKD1 and PKD1L3 respectively, to form receptor–cation-channel complexes. The PKD2L1–PKD1L3 complex perceives sour taste, whereas disruption of the PKD2–PKD1 complex, responsible for mechanosensation, leads to development of ADPKD (autosomal-dominant polycystic kidney disease). Besides modulating channel activity and related signalling events, the CRDs (C-terminal regulatory domains) of PKD2 and PKD2L1 play a central role in channel oligomerization. The present study investigates the aggregation state of purified full-length PKD2L1-CRD as well as truncations of CRDs from PKD2 channels. Far- and near-UV CD spectroscopy show that the full-length PKD2L1 CRD (PKD2L1-198) and the truncated PKD2 CRD (PKD2-244) are α-helical with no β-sheet, the α-helix content agrees with sequence-based predictions, and some of its aromatic residues are in an asymmetric environment created at least by partially structured regions. Additionally, the CRD truncations exhibit an expected biochemical function by binding Ca2+ in a physiologically relevant range with Kd values of 2.8 μM for PKD2-244 and 0.51 μM for PKD2L1-198. Complimentary biophysical and biochemical techniques establish that truncations of the PKD2 and PKD2L1 CRDs are elongated molecules that assemble as trimers, and the trimeric aggregation state is independent of Ca2+ binding. Finally, we show that a common coiled-coil motif is sufficient and necessary to drive oligomerization of the PKD2 and PKD2L1 CRD truncations under study. Despite the moderate sequence identity (39%) between CRDs of PKD2 and PKD2L1, they both form trimers, implying that trimeric organization of CRDs may be true of all polycystin channels.
The reconstituted Escherichia coli MsbA protein displays lipid flippase activity
Authors: Eckford Paul D. W. , Sharom Frances J. 
Published: April 2010

The MsbA protein is an essential ABC (ATP-binding-cassette) superfamily member in Gram-negative bacteria. This 65 kDa membrane protein is thought to function as a homodimeric ATP-dependent lipid translocase or flippase that transports lipid A from the inner to the outer leaflet of the cytoplasmic membrane. We have previously shown that purified MsbA from Escherichia coli displays high ATPase activity, and binds to lipids and lipid-like molecules, including lipid A, with affinity in the low micromolar range. Bacterial membrane vesicles isolated from E. coli overexpressing His6-tagged MsbA displayed ATP-dependent translocation of several fluorescently NBD (7-nitrobenz-2-oxa-1,3-diazole)-labelled phospholipid species. Purified MsbA was reconstituted into proteoliposomes of E. coli lipid and its ability to translocate NBD-labelled lipid derivatives was characterized. In this system, the protein displayed maximal lipid flippase activity of 7.7 nmol of lipid translocated per mg of protein over a 20 min period for an acyl chain-labelled PE (phosphatidylethanolamine) derivative. The protein showed the highest rates of flippase activity when reconstituted into an E. coli lipid mixture. Substantial flippase activity was also observed for a variety of other NBD-labelled phospholipids and glycolipids, including molecules labelled on either the headgroup or the acyl chain. Lipid flippase activity required ATP hydrolysis, and was dependent on the concentration of ATP and NBD–lipid. Translocation of NBD–PE was inhibited by the presence of the putative physiological substrate lipid A. The present paper represents the first report of a direct measurement of the lipid flippase activity of purified MsbA in a reconstituted system.
Transferrin-iron routing to the cytosol and mitochondria as studied by live and real-time fluorescence
Authors: Shvartsman Maya , Fibach Eitan , Cabantchik Z. Ioav 
Published: April 2010

In the present study we analysed the mechanism of intracellular routing of iron acquired by erythroid cells via receptor-mediated endocytosis of Tf-Fe [Tf (transferrin)-iron]. Using real-time fluorimetry and flow cytometry, in conjunction with targeted fluorescent metal sensors, we monitored concurrently the cytosolic and mitochondrial changes in labile iron evoked by endocytosed Tf-Fe. In K562 human erythroleukaemia cells, most of the Tf-Fe was found to be delivered to the cytosolic labile iron pool by a saturable mechanism [60–120 nM Km (app)] that was quantitatively dependent on: Tf receptor levels, endosomal acidification/reduction for dislodging iron from Tf and ensuing translocation of labile iron into the cytosolic compartment. The parallel ingress of iron to mitochondria was also saturable, but with a relatively lower Km (app) (26–42 nM) and a lower maximal ingress per cell than into the cytosol. The ingress of iron into the mitochondrial labile iron pool was blocked by cytosol-targeted iron chelators, implying that a substantial fraction of Tf-Fe delivered to these organelles passes through the cytosol in non-occluded forms that remain accessible to high-affinity ligands. The present paper is the first report describing intracellular iron routing measured in intact cells in real-time and in quantitative terms, opening the road for also exploring the process in mixed-cell populations of erythroid origin.
Comparative effects of telmisartan, sitagliptin and metformin alone or in combination on obesity, insulin resistance, and liver and pancreas remodelling in C57BL/6 mice fed on a very high-fat diet
Authors: Souza-Mello Vanessa , Gregório Bianca M. , Cardoso-de-Lemos Fernando S. , de Carvalho Laís , Aguila Márcia B. , Mandarim-de-Lacerda Carlos A. 
Published: April 2010

The aim of the present study was to evaluate the effects of monotherapies and combinations of drugs on insulin sensitivity, adipose tissue morphology, and pancreatic and hepatic remodelling in C57BL/6 mice fed on a very HF (high-fat) diet. Male C57BL/6 mice were fed on an HF (60% lipids) diet or SC (standard chow; 10% lipids) diet for 10 weeks, after which time the following drug treatments began: HF-T (HF diet treated with telmisartan; 5.2 mg·kg−1 of body weight·day−1), HF-S (HF diet treated with sitagliptin; 1.08 g·kg−1 of body weight·day−1), HF-M (HF diet treated with metformin; 310.0 mg·kg−1 of body weight·day−1), HF-TM (HF diet treated with telmisartan+metformin), HF-TS (HF diet treated with telmisartan+sitagliptin) and HF-SM (HF diet treated with sitagliptin+metformin). Treated groups also had free access to the HF diet, and treatments lasted for 6 weeks. Morphometry, stereological tools, immunostaining, ELISA, Western blot analysis and electron microscopy were used. The HF diet yielded an overweight phenotype, an increase in oral glucose intolerance, hyperinsulinaemia, hypertrophied islets and adipocytes, stage 2 steatosis (&gt;33%), and reduced liver PPAR-α (peroxisome-proliferator-activated receptor-α) and GLUT-2 (glucose transporter-2) levels, concomitant with enhanced SREBP-1 (sterol-regulatory-element-binding protein-1) expression (P&lt;0.0001). Conversely, all drug treatments resulted in significant weight loss, a reversal of insulin resistance, islet and adipocyte hypertrophy, and alleviated hepatic steatosis. Only the HF-T and HF-TS groups had body weights similar to the SC group at the end of the experiment, and the latter treatment reversed hepatic steatosis. Increased PPAR-α immunostaining in parallel with higher GLUT-2 and reduced SREBP-1 expression may explain the favourable hepatic outcomes. Restoration of adipocyte size was consistent with higher adiponectin levels and lower TNF-α (tumour necrosis factor-α) levels (P&lt;0.0001) in the drug-treated groups. In conclusion, all of the drug treatments were effective in controlling the metabolic syndrome. The best results were achieved using telmisartan and sitagliptin as monotherapies or as a dual treatment, combining partial PPAR-γ agonism and PPAR-α activation in the liver with extended incretin action.