bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic differences in vertical connectivity in the Caribbean coral Montastraea cavernosa despite high levels of horizontal connectivity at shallow depths
Authors: Serrano X. , Baums I. B. , O'Reilly K. , Smith T. B. , Jones R. J. , Shearer T. L. , Nunes F. L. D. , Baker A. C.
Published: July 2014

The deep reef refugia hypothesis proposes that deep reefs can act as local recruitment sources for shallow reefs following disturbance. To test this hypothesis, nine polymorphic DNA microsatellite loci were developed and used to assess vertical connectivity in 583 coral colonies of the Caribbean depth‐generalist coral Montastraea cavernosa. Samples were collected from three depth zones (≤10, 15–20 and ≥25 m) at sites in Florida (within the Upper Keys, Lower Keys and Dry Tortugas), Bermuda, and the U.S. Virgin Islands. Migration rates were estimated to determine the probability of coral larval migration from shallow to deep and from deep to shallow. Finally, algal symbiont (Symbiodinium spp.) diversity and distribution were assessed in a subset of corals to test whether symbiont depth zonation might indicate limited vertical connectivity. Overall, analyses revealed significant genetic differentiation by depth in Florida, but not in Bermuda or the U.S. Virgin Islands, despite high levels of horizontal connectivity between these geographic locations at shallow depths. Within Florida, greater vertical connectivity was observed in the Dry Tortugas compared to the Lower or Upper Keys. However, at all sites, and regardless of the extent of vertical connectivity, migration occurred asymmetrically, with greater likelihood of migration from shallow to intermediate/deep habitats. Finally, most colonies hosted a single Symbiodinium type (C3), ruling out symbiont depth zonation of the dominant symbiont type as a structuring factor. Together, these findings suggest that the potential for shallow reefs to recover from deep‐water refugia in M. cavernosa is location‐specific, varying among and within geographic locations likely as a consequence of local hydrology.
Discovery of the first light‐dependent protochlorophyllide oxidoreductase in anoxygenic phototrophic bacteria
Authors: Kaschner Marco , Loeschcke Anita , Krause Judith , Minh Bui Quang , Heck Achim , Endres Stephan , Svensson Vera , Wirtz Astrid , von Haeseler Arndt , Jaeger Karl‐Erich , Drepper Thomas , Krauss Ulrich
Published: July 2014

In all photosynthetic organisms, chlorophylls function as light‐absorbing photopigments allowing the efficient harvesting of light energy. Chlorophyll biosynthesis recurs in similar ways in anoxygenic phototrophic proteobacteria as well as oxygenic phototrophic cyanobacteria and plants. Here, the biocatalytic conversion of protochlorophyllide to chlorophyllide is catalysed by evolutionary and structurally distinct protochlorophyllide reductases (PORs) in anoxygenic and oxygenic phototrophs. It is commonly assumed that anoxygenic phototrophs only contain oxygen‐sensitive dark‐operative PORs (DPORs), which catalyse protochlorophyllide reduction independent of the presence of light. In contrast, oxygenic phototrophs additionally (or exclusively) possess oxygen‐insensitive but light‐dependent PORs (LPORs). Based on this observation it was suggested that light‐dependent protochlorophyllide reduction first emerged as a consequence of increased atmospheric oxygen levels caused by oxygenic photosynthesis in cyanobacteria. Here, we provide experimental evidence for the presence of an LPOR in the anoxygenic phototrophic α‐proteobacterium Dinoroseobacter shibae DFL12T. In vitro and in vivo functional assays unequivocally prove light‐dependent protochlorophyllide reduction by this enzyme and reveal that LPORs are not restricted to cyanobacteria and plants. Sequence‐based phylogenetic analyses reconcile our findings with current hypotheses about the evolution of LPORs by suggesting that the light‐dependent enzyme of D. shibae DFL12T might have been obtained from cyanobacteria by horizontal gene transfer.
Serum 1,3‐beta‐d‐glucan for antifungal treatment stratification at the intensive care unit and the influence of surgery
Authors: Prattes Jürgen , Hoenigl Martin , Rabensteiner Jasmin , Raggam Reinhard B. , Prueller Florian , Zollner‐Schwetz Ines , Valentin Thomas , Hönigl Katharina , Fruhwald Sonja , Krause Robert
Published: July 2014

The purpose of this study was to evaluate a preemptive approach with serum 1,3‐beta‐d‐glucan (BDG) as a marker for treatment stratification of systemic antifungal (AF) therapy in patients with clinical suspected invasive fungal infections (IFI) at intensive care units (ICU), and the impact of surgical procedures. A total of 66 ICU patients with clinical suspected IFI were included in this retrospective analysis. Serum BDG testing was performed prior to initiation of AF treatment and in addition to routine diagnostic measures. Based on the BDG results the initial clinical decision whether or not to start systemic AF therapy was re‐evaluated. Impact of surgical procedures on clinical utility of serum BDG was evaluated in a sub‐group of 25 patients who had undergone surgical procedures prior to BDG evaluation. BDG test results led to discontinuation of AF therapy in 13 patients, and initiation of AF therapy in seven patients. In 46 patients the clinical decision was confirmed by BDG. The majority of suspected, probable and proven IFI cases (10/13, 77%) was predicted by the test. BDG testing turned out positive in 9/25 (36%) of patients that had undergone recent surgery and levels correlated with clinical findings. Serum BDG evaluation seems to be a promising tool to guide AF therapy in ICU patients even after recent surgical procedures.
Endoscopic ultrasound as an adjunctive evaluation in patients with esophageal motor disorders subtyped by high‐resolution manometry
Authors: Krishnan K. , Lin C.‐Y. , Keswani R. , Pandolfino J. E. , Kahrilas P. J. , Komanduri S.
Published: July 2014

Background

Esophageal motor disorders are a heterogeneous group of conditions identified by esophageal manometry that lead to esophageal dysfunction. The aim of this study was to assess the clinical utility of endoscopic ultrasound (EUS) in the further evaluation of patients with esophageal motor disorders categorized using the updated Chicago Classification.

Methods

We performed a retrospective, single center study of 62 patients with esophageal motor disorders categorized according to the Chicago Classification. All patients underwent standard radial endosonography to assess for extra‐esophageal findings or alternative explanations for esophageal outflow obstruction. Secondary outcomes included esophageal wall thickness among the different patient subsets within the Chicago Classification.

Key Results

EUS identified 9/62 (15%) clinically relevant findings that altered patient management and explained the etiology of esophageal outflow obstruction. We further identified substantial variability in esophageal wall thickness in a proportion of patients including some with a significantly thickened non‐muscular layer.

Conclusions & Inferences

EUS findings are clinically relevant in a significant number of patients with motor disorders and can alter clinical management. Variability in esophageal wall thickness of the muscularis propria and non‐muscular layers identified by EUS may also explain the observed variability in response to standard therapies for achalasia.
Climate refugia: joint inference from fossil records, species distribution models and phylogeography
Authors: Gavin Daniel G. , Fitzpatrick Matthew C. , Gugger Paul F. , Heath Katy D. , Rodríguez‐Sánchez Francisco , Dobrowski Solomon Z. , Hampe Arndt , Hu Feng Sheng , Ashcroft Michael B. , Bartlein Patrick J. , Blois Jessica L. , Carstens Bryan C. , Davis Edward B. , de Lafontaine Guillaume , Edwards Mary E. , Fernandez Matias , Henne Paul D. , Herring Erin M. , Holden Zachary A. , Kong Woo‐seok , Liu Jianquan , Magri Donatella , Matzke Nicholas J. , McGlone Matt S. , Saltré Frédérik , Stigall Alycia L. , Tsai Yi‐Hsin Erica , Williams John W.
Published: July 2014

Climate refugia, locations where taxa survive periods of regionally adverse climate, are thought to be critical for maintaining biodiversity through the glacial–interglacial climate changes of the Quaternary. A critical research need is to better integrate and reconcile the three major lines of evidence used to infer the existence of past refugia – fossil records, species distribution models and phylogeographic surveys – in order to characterize the complex spatiotemporal trajectories of species and populations in and out of refugia. Here we review the complementary strengths, limitations and new advances for these three approaches. We provide case studies to illustrate their combined application, and point the way towards new opportunities for synthesizing these disparate lines of evidence. Case studies with European beech, Qinghai spruce and Douglas‐fir illustrate how the combination of these three approaches successfully resolves complex species histories not attainable from any one approach. Promising new statistical techniques can capitalize on the strengths of each method and provide a robust quantitative reconstruction of species history. Studying past refugia can help identify contemporary refugia and clarify their conservation significance, in particular by elucidating the fine‐scale processes and the particular geographic locations that buffer species against rapidly changing climate.

Contents

Summary
38

I.
Climate refugia: biogeographical and conservation significance
38

II.
Approaches for reconstructing refugia: strengths, limitations and recent advances
39

III.
Climate refugia of the past: three case studies
46

IV.
New integrative approaches to reconstructing refugia
47

V.
How can historical refugia inform us about future refugia?
48

VI.
Concluding thoughts
49

Acknowledgements
49

References
49
Frequent Premature Ventricular Complex Is Associated with Left Atrial Enlargement in Patients with Normal Left Ventricular Ejection Fraction
Authors: PARK YEONJEONG , KIM SUJI , SHIN JEWOOK , OH AH REUM , SHIN EUN JI , LEE JUNG HOON , AHN TAEHOON , CHA JI‐YOUNG , MOON JEONGGEUN
Published: July 2014

Background

Premature ventricular complex (PVC) has been regarded as benign; however, when frequent, the arrhythmia can induce left ventricular (LV) systolic dysfunction. Meanwhile, the influence of PVCs on cardiac structural remodeling and functional change before occurrence of overt systolic heart failure has not been fully described. In this study, we attempted to identify early cardiac structural/functional manifestations of frequent PVCs in patients with normal LV systolic function.

Methods

A total of 146 patients (age: 55 ± 15 years, 48 males) with frequent PVCs observed on 24‐hour Holter monitoring (>10/h) and normal LV ejection fraction (LV EF ≥ 55% on echocardiography) were enrolled. Clinical characteristics and echocardiographic parameters of the patients were compared with those of an age‐/sex‐matched control group (n = 292, age: 55 ± 15 years, 96 males).

Results

Patients with frequent PVCs had significantly larger left atrial volume index (LAVI [28 ± 9 mL/m2 vs. 24 ± 7 mL/m2]), along with larger LV end‐diastolic dimension (49.4 ± 4.4 mm vs. 48.5 ± 3.9 mm), lower LV EF (63 ± 7% vs. 66 ± 6%), and lower peak systolic mitral annular velocity (7 ± 2 cm/s vs. 8 ± 2 cm/s; P < 0.05 for all), whereas other clinical characteristics were similar. In particular, in patients with frequent PVCs, LAVI showed linear correlation with PVC burden (R = 0.30, P < 0.001), and, in a multiple regression model, PVC burden independently estimated LAVI, even after controlling for age, sex, comorbidities, and systolic function (β = 0.309, P < 0.001).

Conclusion

Frequent PVC is associated with LA enlargement in patients with normal LV EF. Atrial anatomical remodeling may precede LV geometry change and systolic dysfunction in patients with frequent PVCs.
Study of Spatial Relationship of Phrenic Nerves with Cardiac Structures Relevant to Electrophysiologic Interventions
Authors: RANDHAWA ARPANDEEP , SAHNI DAISY , AGGARWAL ANJALI , ROHIT MANOJ KUMAR , SEHGAL SHOBHA , REDDY Y MADHU
Published: July 2014

Background

Pulmonary vein (PV) isolation with catheter ablation in treating atrial fibrillation carries the risk of injury to phrenic nerve (PN). Left PN (LPN) stimulation continues to be one of the common complications of transvenous left ventricular lead placement during cardiac resynchronization therapy (CRT).

Methods and Results

In 30 formalin‐fixed cadavers, spatial relationship of PNs with PV ostia, left atrial appendage (LAA), and cardiac veins was observed. Segmental location of LPN and cardiac vein crossover was also noted. Right and left PNs coursed abutting the ostium of right superior and left superior PVs in five (16.6%) and one (3.33%) cases, respectively. LPN coursed along the lateral surface of LAA in 20 (66.66%) cases and behind LAA in one (3.33%) case. Out of 18 (60%) cases having two cardiac veins draining free wall of left ventricle (LV) and suitable for CRT lead placement, both cardiac veins were crossed by LPN in two (6.66%) cases. LPN–cardiac vein crossover was located in midlateral segment in 10 (33.3%) cases; mid posterolateral segment in five (16.7%) cases; apical lateral segment and apical posterolateral segment in three (10.0%) cases each.

Conclusion

PN is highly susceptible to either injury during catheter ablation or stimulation with LV pacing in certain critical locations. Detailed knowledge of spatial relationship of PNs with cardiac structures could help minimize inadvertent complications during these transcatheter electrophysiological procedures.
Are leaves ‘freewheelin'? Testing for a Wheeler‐type effect in leaf xylem hydraulic decline
Authors: SCOFFONI CHRISTINE , SACK LAWREN
Published: July 2014

A recent study found that cutting shoots under water while xylem was under tension (which has been the standard protocol for the past few decades) could produce artefactual embolisms inside the xylem, overestimating hydraulic vulnerability relative to shoots cut under water after relaxing xylem tension (Wheeler et al. 2013). That study also raised the possibility that such a ‘Wheeler effect’ might occur in studies of leaf hydraulic vulnerability. We tested for such an effect for four species by applying a modified vacuum pump method to leaves with minor veins severed, to construct leaf xylem hydraulic vulnerability curves. We tested for an impact on leaf xylem hydraulic conductance (Kx) of cutting the petiole and minor veins under water for dehydrated leaves with xylem under tension compared with dehydrated leaves after previously relaxing xylem tension. Our results showed no significant ‘cutting artefact’ for leaf xylem. The lack of an effect for leaves could not be explained by narrower or shorter xylem conduits, and may be due to lesser mechanical stress imposed when cutting leaf petioles, and/or to rapid refilling of emboli in petioles. These findings provide the first validation of previous measurements of leaf hydraulic vulnerability against this potential artefact.
Diagnosis and treatment of urea cycle disorder in Japan
Authors: Nakamura Kimitoshi , Kido Jun , Mitsubuchi Hiroshi , Endo Fumio
Published: July 2014

Urea cycle disorder (UCD) is an inborn error of the metabolic pathway producing urea from ammonia, which occurs primarily in the liver. Decreased excretion of nitrogen in the urea cycle due to deficiency of carbamoyl phosphate synthase I (CPSI), ornithine transcarbamylase (OTC), argininosuccinate synthase (ASS), argininosuccinate lyase (ASL), and N‐acetyl glutamate synthase (NAGS) causes hyperammonemia. We examined the clinical manifestations, treatment, and prognosis of 177 patients with UCD from January 1999 to March 2009 in Japan. Compared with a previous study conducted in Japan, a larger number of patients survived without mental retardation, even when the peak blood ammonia was >360 μmol/L. In those with peak blood ammonia >360 μmol/L, an indicator of poor prognosis, the frequency of convulsions, mental retardation, brain abnormality on magnetic resonance imaging, hemodialysis, liver transplantation, and intake of non‐protein formulas was significantly higher than in those with peak blood ammonia <360 μmol/L. In this article, we have reported the current state of UCD to evaluate prognosis and its relationship with peak blood ammonia and hemodialysis.
Comparison of potential increases in juvenile salmonid rearing habitat capacity among alternative restoration scenarios, Trinity River, California
Authors: Beechie Timothy J. , Pess George R. , Imaki Hiroo , Martin Aaron , Alvarez Justin , Goodman Damon H.
Published: July 2014

River restoration plans often propose multiple rehabilitation actions to address key habitat impairments, but they rarely attempt to quantify the potential benefits of alternative sets of actions for targeted biota. We use geomorphic and biological analyses to estimate restoration potential under three alternative scenarios for a 64‐km section of the Trinity River, California, between the North Fork Trinity River and Lewiston Dam, which is the focus of habitat rehabilitation efforts under the Trinity River Restoration Program. The three scenarios are (1) increasing habitat quality by wood additions and alcove construction, (2) increasing habitat quantity by increasing sinuosity and side‐channel length, and (3) increasing both habitat quality and quantity. For each scenario, we used existing stream habitat and juvenile salmonid data from previous studies to estimate potential improvements in fry or pre‐smolt production. The potential increase in Oncorhynchus tshawytscha (Chinook salmon) and O. mykiss (steelhead) fry rearing capacity was 62 and 67%, respectively, for Scenario 1 (increasing habitat quality), and 36 and 44% for Scenario 2 (increasing habitat quantity). Only the most optimistic Scenario 3 (increasing both habitat quality and quantity) more than doubles potential juvenile salmonid production (112% increase in Chinook fry capacity and 107% increase in steelhead fry capacity). These quantitative predictions are useful in developing realistic restoration targets and evaluating whether proposed restoration actions can achieve the aims of a restoration program.
The role of personal and key resources in the family‐to‐work enrichment process
Authors: Tement Sara
Published: July 2014

Based on the work‐home resources model, the aim of the present research was to test a process model of family‐to‐work enrichment by examining whether self‐efficacy (i.e., personal resource) mediates the relationship between support from one's family and work engagement. Further, it was assumed that positive affectivity (i.e., key resource) moderates the relation between family support and self‐efficacy. Using an occupationally heterogeneous sample of Slovenian employees (n = 738), we found support for a mediating effect of self‐efficacy as well as for the moderating role of positive affectivity. In general, our results broaden the understanding of work‐family enrichment processes and provide support for the work‐home resources model. In addition, they point to the relevant role of personal and key resources in work‐family interactions.
Soil capability as a predictor of cropland change in Alberta, Canada from 1988 to 2010
Authors: Zhang X. , Huffman T. , Liu J. , Liu H.
Published: July 2014

Understanding the mutual influences between cropland use and soil characteristics is important in anticipating and planning for food production, environmental protection and resource sustainability. Numerous studies focus on the relationship between crop rotations and soil characteristics at a microscale, but fewer studies focus on the relationships between soil capability and cropland use and change at a medium scale. We explore how soil capability has influenced cropland changes over 22 yr, using statistical and land use transition analysis. Landsat images from the years 1988, 2002 and 2010 were used to map cropland changes by soil capability class within a pilot site in Alberta, Canada. Between the late 1980s and 2010: (i) the area of annual crops increased substantially while that of forest and summer‐fallow decreased; (ii) changes in cropland use among annual crops, perennial crops and summer‐fallow differed substantially depending on soil capability; and (iii) a transition from annual crops and summer‐fallow to perennial crops was more likely on land of poorer soil capability, whereas the transition from perennial crops and summer‐fallow to annual crops was more likely on land with higher soil capability. The changes in land use practices identified in this study indicate that producers are actively intensifying production on their best land to optimize profitability while simultaneously reducing the intensity of production on poorer land for either financial or environmental reasons, or both.
Risk‐reducing surgery for women at high risk of epithelial ovarian cancer
Authors: Gaughan Eve Maria Geraldine , Walsh Thomas Anthony
Published: July 2014

Key content

The lifetime risk of ovarian cancer in the general population is 1.4% but women with hereditary ovarian cancer syndromes have a lifetime probability as high as 25–60% for developing epithelial ovarian cancer.

Screening has not been found to be associated with a statistically significant reduction in mortality from ovarian cancer and cannot be routinely recommended even for women at high risk. Serum CA125 levels are only elevated in 50–60% of stage I ovarian cancers and interval cancers may develop between screening visits.

Studies show a 4–20% risk of finding an occult malignancy at the time of risk‐reducing bilateral salpingo‐oophorectomy.

Studies support the efficacy of risk‐reducing bilateral salpingo‐oophorectomy in significantly reducing the risk of gynaecological and breast cancer in women who carry BRCA1 or BRCA2 mutations.

Women undergoing risk‐reduction bilateral salpingo‐oophorectomy should be counselled about the effects of early menopause and the available management options including hormone replacement therapy.

Learning objectives

To be able to identify those women at increased risk of ovarian cancer.

To be able to appropriately counsel those at high risk of ovarian cancer regarding modifiable risk factors, screening and the role of risk‐reducing surgery, including prophylactic bilateral salpingo‐oophorectomy and its alternatives such as tubal ligation and salpingectomy.

To understand the limitations of current screening modalities for the reduction of ovarian cancer risk.

Ethical issues

Ethical concerns exist pertaining to the performance of screening modalities, which have not been found to significantly reduce mortality from ovarian cancer and can cause harm in terms of psychological and surgical morbidity from false‐positive results.

For those with a positive family history of ovarian cancer but no genetic cancer syndrome, the discussion to perform risk‐reducing surgery should be balanced against the risk of surgical morbidity and early menopause. Individual patient risk factors must be considered in the decision‐making process.
The Hand: Shall We Ever Understand How It Works?
Authors: Latash Mark L.
Published: July 2014

The target article presents a review of the neural control of the human hand. The review emphasizes the physical approach to motor control. It focuses on such concepts as equilibrium-point control, control with referent body configurations, uncontrolled manifold hypothesis, principle of abundance, hierarchical control, multidigit synergies, and anticipatory synergy adjustments. Changes in aspects of the hand neural control with age and neurological disorder are discussed. The target article is followed by six commentaries written by Alexander Aruin, Kelly Cole, Monica Perez, Robert Sainburg, Marco Sanello, and Wei Zhang.
Cell and tissue engineering for liver disease
Authors: Bhatia Sangeeta N. , Underhill Gregory H. , Zaret Kenneth S. , Fox Ira J.
Published: July 2014

Advances in cell and tissue engineering are moving cell-based therapies for treating liver disease and liver failure closer to the clinic.
Improving management of constipation in an inpatient setting using a care bundle
Authors: Linton Andrew
Published: July 2014

Constipation is a common occurrence on geriatric in-patient wards. It can result in delirium and other complications including bowel obstruction. Over treatment with laxatives can result in iatrogenic diahorrea, which can lead to dehydration, delirium, and the false positive labeling and unnecessary treatment of clostridium difficile carriers. This can result in increased morbidity and mortality, and a longer stay in hospital. This means that improving the assessment and treatment of constipation should improve patient outcomes and result in significant hospital cost savings.

Multidisciplinary discussion and planning resulted in the delivery of our constipation project. This aimed to encourage the early assessment and treatment of constipation of inpatients on a geriatric rehabilitation ward. The goal was to prevent significant constipation by intervening early, improving the prescription of laxatives, and titrating them when the constipation has resolved. This involved educational sessions, non-pharmacological alternatives to laxatives (optimisation of hydration, exercise, and high fibre foods), laxative prescription guidance, and twice weekly laxative ward rounds.

The profile of laxative prescription changed in keeping with our guidance. There was a reduction in overall laxative prescription by a third and the prescription of "PRN" laxatives was eliminated. This hopefully resulted in reduced morbidity for the patients and reduced length of stay. There was a cost savings on the laxative bill on average per day of the project, which when extrapolated to a 365 day year was £1226.40. This doesn't include potential savings gained from reduced complications of constipation and reduced length of stay, which are hard to accurately measure.
Tests of modified gravity theories in the Solar System
Authors: Mozaffari Ali
Published: July 2014

We review the case for testing preferred acceleration scale theories of gravity (sometimes falling under the guise of modified Newtonian dynamics) in the Solar System using the forthcoming LISA Pathfinder (LPF) mission. Using a combination of analytical and numerical results, we suggest that different types of theory should be detectable using the predicted anomalous tidal stresses effects around the saddle points of the Newtonian gravitational field. The saddle point bubbles’ expected extent of ∼400 km are to be contrasted with potential miss parameters of ≤10 km, making such a test in easy reach of LPF. We also consider routes to constraining our theories from data, based on scenarios of both null and positive results.
Perihelion advances for the orbits of Mercury, Earth, and Pluto from extended theory of general relativity (ETGR)
Authors: Ridao Luis Santiago , Avalos Rodrigo , De Cicco Martín Daniel , Bellini Mauricio
Published: July 2014

We explore the geodesic movement on an effective four-dimensional hypersurface that is embedded in a five-dimensional Ricci-flat manifold described by a canonical metric, to applying to planetary orbits in our solar system. Some important solutions are given, which provide the standard solutions of general relativity without any extra force component. We study the perihelion advances of Mercury, the Earth, and Pluto using the extended theory of general relativity. Our results are in very good agreement with observations and show how the foliation is determinant to the value of the perihelion’s advances. Possible applications are not limited to these kinds of orbits.
Plasmon dispersions in ultrathin metallic films
Authors: Wu Reng-Lai , Long Ye-Jun , Xue Hong-Jie , Yu Yabin , Hu Hui-Fang
Published: July 2014

We present an eigen-equation for plasmon of ultrathin films based on the self-consistent linear response approximation (SCLRA). The calculations for plasmon dispersion in both single and multilayer systems are reported. There are two types of plasmon in the plasmon spectrum, two-dimensional (2D) and bulk-like (BL) modes. The plasmon energy of the 2D mode is zero in the long wave limit, while the one of BL mode is nonzero in the long-wave limit. Given a surface electron density, with the decrease of the wave vector the dispersions of the 2D plasmon of different layer systems become equal to each other, and approach results of the pure 2D system.
FEATURE GROUP MATCHING: A NOVEL METHOD TO FILTER OUT INCORRECT LOCAL FEATURE MATCHINGS
Authors: FRONTONI EMANUELE , MANCINI ADRIANO , ZINGARETTI PRIMO
Published: July 2014

The importance of finding correct correspondences between two images is the major aspect in problems such as appearance-based robot localization and content-based image retrieval. Local feature matching has become a commonly used method to compare images, despite being highly probable that at least some of the matchings/correspondences it detects are incorrect. In this paper, we describe a novel approach to local feature matching, named Feature Group Matching (FGM), to select stable features and obtain a more reliable similarity value between two images. The proposed technique is demonstrated to be translational, rotational and scaling invariant. Experimental evaluation was performed on large and heterogeneous datasets of images using SIFT and SURF, the actual state-of-the-art feature extractors. Results show that FGM avoids almost 95% of incorrect matchings, reduces the visual aliasing (number of images considered similar) and increases both robotic localization and image retrieval accuracy on the average of 13%.
Analysis of Ultrasonic Guided Waves Propagation in Complex Composite Structures
Authors: Raišutis Renaldas , Žukauskas Egidijus , Samaitis Vykintas , Jankauskas Audrius , Draudvilienė Lina , Griškevičius Paulius , Juzėnas Kazimieras
Published: July 2014

The object of the investigation is a honeycomb structure of composite sandwich made of glass-epoxy laminating layers and a honeycomb core of epoxy impregnated paper. Large composite tanks possessing cylindrical shape are produced using the winding process. Therefore, the final products have uneven thickness and fibre orientation lamina layers, and also an unevenly impregnated honeycomb layer. The aim of this research is to develop an economically attractive embedded ultrasonic measurement technique for on-field diagnostics of complex composite structures used for production of large liquid storage tanks. Development of the relatively cheap and easy to operate embedded diagnostic/monitoring technique is important aiming to assure safety of liquid storage tanks (monitoring structural integrity against overpressure, etc.) and detection of accidental defects that may appear during transportation, installation and exploitation of those structures. Typical defects that are aimed to be detected are relatively large delaminations/disbonds (area having diameter of 150–200 mm) of skin layers caused by low energy impacts that cannot be detected visually and show severe influence on the structural strength and safety of liquid tanks. This work presents results of numerical modeling and experimental research in low frequency (50 kHz) ultrasonic guided waves (UGW) propagation in large honeycomb composite structures. Finite element (FE) simulation of UGW propagation has been made aiming to reduce quantity of ultrasonic transducers and optimize their placement on composite structure. The possibilities to place ultrasonic transducers and receivers on both sides (internal or external) of composite structures and to use such a proposed technique for detection of delamination/debonding areas caused by low energy impacts or alternating semi static loads (e.g. filling and draining of liquid from storage tank) and monitoring of partial self-healing of relatively rigid composite structures were proved by experimental testing.
Toward Hybrid Nanostructure-Slime Mould Devices
Authors: Mayne Richard , Adamatzky Andrew
Published: July 2014

The plasmodium of slime mould Physarum polycephalum has recently received significant attention for its value as a highly malleable amorphous computing substrate. In laboratory-based experiments, nanoscale artificial circuit components were introduced into the P. polycephalum plasmdodium to investigate the electrical properties and computational abilities of hybridized slime mould. It was found through a combination of imaging techniques and electrophysiological measurements that P. polycephalum is able to internalize a range of electrically active nanoparticles (NPs), assemble them in vivo and distribute them around the plasmodium. Hybridized plasmodium is able to form biomorphic mineralized networks inside the living plasmodium and the empty trails left following its migration, both of which facilitate the transmission of electricity. Hybridization also alters the bioelectrical activity of the plasmodium and likely influences its information processing capabilities. It was concluded that hybridized slime mould is a suitable substrate for producing functional unconventional computing devices.
Malware Analysis Using Visualized Image Matrices
Authors: Han KyoungSoo , Kang BooJoong , Im Eul Gyu
Published: July 2014

This paper proposes a novel malware visual analysis method that contains not only a visualization method to convert binary files into images, but also a similarity calculation method between these images. The proposed method generates RGB-colored pixels on image matrices using the opcode sequences extracted from malware samples and calculates the similarities for the image matrices. Particularly, our proposed methods are available for packed malware samples by applying them to the execution traces extracted through dynamic analysis. When the images are generated, we can reduce the overheads by extracting the opcode sequences only from the blocks that include the instructions related to staple behaviors such as functions and application programming interface (API) calls. In addition, we propose a technique that generates a representative image for each malware family in order to reduce the number of comparisons for the classification of unknown samples and the colored pixel information in the image matrices is used to calculate the similarities between the images. Our experimental results show that the image matrices of malware can effectively be used to classify malware families both statically and dynamically with accuracy of 0.9896 and 0.9732, respectively.
A Method to Characterize the Quality of a Polymer Laser Sintering Process
Authors: Rüsenberg Stefan , Josupeit Stefan , Schmid Hans-Joachim
Published: July 2014

The reproducibility and reliability of quality aspects are an important challenge of the polymer laser sintering process. However, existing quality concepts and standardization activities considering influencing factors along the whole process chain have not been validated experimentally yet. In this work, these factors are analyzed and kept constant to obtain a reliable material data set for different layer thicknesses and testing temperatures. In addition, material qualities regarding powder ageing effects are analyzed using different build heights and layer thicknesses: while an increase of the layer thickness reduces mechanical part strength and density, it also results in a less intense thermal ageing of unmolten powder due to shorter build times.
Daily Crude Oil Price Forecasting Using Hybridizing Wavelet and Artificial Neural Network Model
Authors: Shabri Ani , Samsudin Ruhaidah
Published: July 2014

A new method based on integrating discrete wavelet transform and artificial neural networks (WANN) model for daily crude oil price forecasting is proposed. The discrete Mallat wavelet transform is used to decompose the crude price series into one approximation series and some details series (DS). The new series obtained by adding the effective one approximation series and DS component is then used as input into the ANN model to forecast crude oil price. The relative performance of WANN model was compared to regular ANN model for crude oil forecasting at lead times of 1 day for two main crude oil price series, West Texas Intermediate (WTI) and Brent crude oil spot prices. In both cases, WANN model was found to provide more accurate crude oil prices forecasts than individual ANN model.
Real-Time 3D Simulation for the Trawl Fishing Gear Based on Parallel Processing of Sonar Sensor Data
Authors: Park Myeong-Chul , Ha Ok-Kyoon , Ha Seok-Wun , Jun Yong-Kee
Published: July 2014

A huge and a complex internal computation is required to visualize the underwater geometry of a fishing gear, because each particle of the gear should be calculated with consideration of several force vectors, such as the movements of the fishing vessel, the buoyancy of the gear, and the tension of pulling or pursing acting on the net panels. The internal computation is the main drawback for providing a real-time visualization that takes into account the force vectors and the changes of underwater environments which can be obtained from the multiple sonar sensors. This paper presents a three-dimensional (3D) visualization tool that offers real-time simulations of the trawl fishing gear using parallel processing for the particles applying the force vectors. This tool also offers different underwater geometries for each fishing gear through a multiview display. The tool employs OpenMP APIs and OpenGL libraries to calculate in parallel the particles and to draw the underwater shapes of fishing gears, respectively. This work can be applied to other simulation systems for analyzing the precise model of graphical geometries as well as modeling the underwater shapes of fishing gears.
A Novel User Classification Method for Femtocell Network by Using Affinity Propagation Algorithm and Artificial Neural Network
Authors: Ahmed Afaz Uddin , Tariqul Islam Mohammad , Ismail Mahamod , Kibria Salehin , Arshad Haslina
Published: July 2014

An artificial neural network (ANN) and affinity propagation (AP) algorithm based user categorization technique is presented. The proposed algorithm is designed for closed access femtocell network. ANN is used for user classification process and AP algorithm is used to optimize the ANN training process. AP selects the best possible training samples for faster ANN training cycle. The users are distinguished by using the difference of received signal strength in a multielement femtocell device. A previously developed directive microstrip antenna is used to configure the femtocell device. Simulation results show that, for a particular house pattern, the categorization technique without AP algorithm takes 5 indoor users and 10 outdoor users to attain an error-free operation. While integrating AP algorithm with ANN, the system takes 60% less training samples reducing the training time up to 50%. This procedure makes the femtocell more effective for closed access operation.
An Extended SISa Model for Sentiment Contagion
Authors: Liu Zhifeng , Zhang Tingting , Lan Qiujun
Published: July 2014

One of the main differences between sentiment and infectious diseases is that the former one has two opposite infectious states: positive (optimistic) and negative (pessimistic), while the latter one has not. In this paper, based on the SISa model, we consider this issue and propose a new model of sentiment contagion called the SOSa-SPSa model. The results of both numerical and agent-based simulations show that our model could explain the process of sentiment contagion better than that of Hill et al. (2010). Further analysis shows that both the numbers of optimistic and pessimistic individuals will increase with the probability of spontaneity or contagion and decrease with the probability of recovery. Potential applications of this model in financial market have also been discussed.
Determination of Location and Depth of Mineral Rocks at Olode Village in Ibadan, Oyo State, Nigeria, Using Geophysical Methods
Authors: Ojo Akintayo O. , Omotoso Toyin O. , Adekanle Olorunyomi J.
Published: July 2014

Magnetic and resistivity geophysical methods were used to investigate the location and depth of mineral rocks at Olode village, Oyo State, Nigeria. 80 magnetic data points were acquired in 10 profiles using G-816 proton precession magnetometer with 10 m spacing in between each profiles and 10 m stations interval. After correcting diurnal variations, the raw magnetic data obtained were plotted as 2D and 3D magnetic contour maps. The residual anomalies obtained were plotted against distance using Microsoft Excel, and Peter’s half-slope method was used to find the depth to the magnetic sources. The magnetic signature obtained show considerable varying amplitude from a minimum value of 155.3 nT at a depth of 6.37 m to a maximum value of 670.3 nT at a depth of 6.25 m. Resistivity data were obtained using Campus Tiger resistivity meter and 9 VESs were acquired using Schlumberger configuration. All VESs were 150 m long, 75 m on each side of the referenced points which were 10 m apart. VESs 1–4 and 7–9 are underlined with rocks of high conductivity and susceptibility values. VESs 5 and 6 show rocks with low conductivity and susceptibility values. The results of these geophysical methods show that there are rocks with high magnetic susceptibility and conductivity values from the centre towards the eastern region of the study area and low magnetic susceptibility and conductivity values at the western region. On the average, the depths of these rocks from the surface fall in the interval of 5.80 m to 6.72 m.
S-Shaped Canals: A Series of Cases Performed by Four Specialists around the World
Authors: Machado Ricardo , Chaniottis Antonis , Vera Jorge , Saucedo Carlos , Vansan Luiz Pascoal , Silva Emmanuel João Nogueira Leal
Published: July 2014

Recognition of anatomical variations is a real challenge for clinicians undertaking therapy regardless of the teeth that are to be treated. The extent of the curvature is one of the most important variables that could lead to instrument fracture. In clinical conditions, two curves can be present in the same root canal trajectory. This type of geometry is denoted as the “S” shape, and it is a challenging condition. This report describes a different clinical and educational scenario where four specialists around the world present different approaches for the treatment of root canals with double curvatures or S-shaped canals. Endodontic therapy is a very nuanced and challenging science and art. The clinical and teaching experience of the authors show different approaches that can be successfully employed to treat challenging teeth having roots with multiple curves. The necessity of precise knowledge of the root canal morphology and its variation is also underlined.
Fractional Differential Equations with Fractional Impulsive and Nonseparated Boundary Conditions
Authors: Fu Xi , Liu Xiaoyou
Published: July 2014

This paper studies the existence results for nonseparated boundary value problems of fractional differential equations with fractional impulsive conditions. By means of Schaefer fixed point theorem, Banach fixed point theorem, and nonlinear alternative of Leray-Schauder type, some existence results are obtained. Examples are given to illustrate the results.
Simple BiCMOS CCCTA Design and Resistorless Analog Function Realization
Authors: Tangsrirat Worapong
Published: July 2014

The simple realization of the current-controlled conveyor transconductance amplifier (CCCTA) in BiCMOS technology is introduced. The proposed BiCMOS CCCTA realization is based on the use of differential pair and basic current mirror, which results in simple structure. Its characteristics, that is, parasitic resistance(Rx)and current transfer(io/iz), are also tunable electronically by external bias currents. The realized circuit is suitable for fabrication using standard 0.35 μm BiCMOS technology. Some simple and compact resistorless applications employing the proposed CCCTA as active elements are also suggested, which show that their circuit characteristics with electronic controllability are obtained. PSPICE simulation results demonstrating the circuit behaviors and confirming the theoretical analysis are performed.
Exact Controllability of an Impulsive Semilinear System with Deviated Argument in a Banach Space
Authors: Das Sanjukta , Pandey Dwijendra N. , Sukavanam N.
Published: July 2014

A functional differential equation with deviated argument coupled with impulsive conditions is studied for the existence and uniqueness of the mild solution and exact controllability of the system. The results are obtained by using Banach contraction principle and C0 semigroup theory without imposing additional assumptions such as analyticity and compactness conditions on the generated semigroup and the nonlinear term. An example is provided to illustrate the presented theory.
On the Flow Instabilities and Turbulent Kinetic Energy of Large-Scale Francis Hydroturbine Model at Low Flow Rate Conditions
Authors: Su Wen-Tao , Li Xiao-Bin , Li Feng-Chen , Wei Xian-Zhu , Liu Jin-Tao , Wu Yu-Lin
Published: July 2014

This paper is to make a better understanding of the flow instabilities and turbulent kinetic energy (TKE) features in a large-scale Francis hydroturbine model. The flow instability with aspect of pressure oscillation and pressure-velocity correlation was investigated using large eddy simulation (LES) method along with two-phase cavitation model. The numerical simulation procedures were validated by the existing experimental result, and further the TKE evolution was analyzed in a curvilinear coordinates. By monitoring the fluctuating pressure and velocities in the vanes’ wake region, the local pressure and velocity variations were proven to have a phase difference approaching π/2, with a reasonable cross-correlation coefficient. Also the simultaneous evolution of pressure fluctuations at the opposite locations possessed a clear phase difference of π, indicating the stresses variations on the runner induced by pressure oscillation were in an odd number of nodal diameter. Considering the TKE generation, the streamwise velocity component u s′2 contributed the most to the TKE, and thus the normal stress production term and shear stress production term imparted more instability to the flow than other production terms.
Punctuated Evolution of Influenza Virus Neuraminidase (A/H1N1) under Opposing Migration and Vaccination Pressures
Authors: Phillips J. C.
Published: July 2014

Influenza virus contains two highly variable envelope glycoproteins, hemagglutinin (HA) and neuraminidase (NA). The structure and properties of HA, which is responsible for binding the virus to the cell that is being infected, change significantly when the virus is transmitted from avian or swine species to humans. Here we focus first on the simpler problem of the much smaller human individual evolutionary amino acid mutational changes in NA, which cleaves sialic acid groups and is required for influenza virus replication. Our thermodynamic panorama shows that very small amino acid changes can be monitored very accurately across many historic (1945–2011) Uniprot and NCBI strains using hydropathicity scales to quantify the roughness of water film packages. Quantitative sequential analysis is most effective with the fractal differential hydropathicity scale based on protein self-organized criticality (SOC). Our analysis shows that large-scale vaccination programs have been responsible for a very large convergent reduction in common influenza severity in the last century. Hydropathic analysis is capable of interpreting and even predicting trends of functional changes in mutation prolific viruses directly from amino acid sequences alone. An engineered strain of NA1 is described which could well be significantly less virulent than current circulating strains.