bluuebunny/crossref_metadata_2025 huggingface dataset:
Phage‐display library biopanning as a novel approach to identifying nematode vaccine antigens
Authors: ELLIS S. E. , NEWLANDS G. F. J. , NISBET A. J. , MATTHEWS J. B.
Published: July 2011

Infections with parasitic nematodes are of significant welfare and economic importance worldwide, and because of the emergence of anthelmintic resistance, this has lead to alternative methods of parasite control being required. Vaccination offers a feasible alternative control, and the majority of research has focused on the production of recombinant versions of native antigens previously identified as protective in vaccinated animals. Attempts at the production of protective recombinant subunit vaccines have been hindered, however, as these antigens have invariably failed to replicate the same level of protective immune response as seen with the native versions. It has been proposed that these failures are owing to the fact that the recombinant proteins do not contain the appropriate post‐translational modifications to retain the protective capacity of the native molecules. In this review, we discuss a novel approach to vaccine antigen identification through the application of random peptide phage‐display libraries and their use to identify peptide sequences that potentially mimic the structure(s) of antigenic epitopes. This area of research is still relatively novel with respect to parasites, and the current state of the art will be discussed here.
Gibberellin partly mediates LANCEOLATE activity in tomato
Authors: Yanai Osnat , Shani Eilon , Russ Dor , Ori Naomi
Published: July 2011

Elaboration of a compound leaf shape depends on extended morphogenetic activity in developing leaves. In tomato (Solanum lycopersicum), the CIN‐TCP transcription factor LANCEOLATE (LA) promotes leaf differentiation. LA is negatively regulated by miR319 during the early stages of leaf development, and decreased sensitivity of LA mRNA to miR319 recognition in the semi‐dominant mutant La leads to prematurely increased LA expression, precocious leaf differentiation and a simpler and smaller leaf. Increased levels or responses of the plant hormone gibberellin (GA) in tomato leaves also led to a simplified leaf form. Here, we show that LA activity is mediated in part by GA. Expression of the SlGA20 oxidase1 (SlGA20ox1) gene, which encodes an enzyme in the GA biosynthesis pathway, is increased in gain‐of‐function La mutants and reduced in plants that over‐express miR319. Conversely, the transcript levels of the GA deactivation gene SlGA2 oxidase4 (SlGA2ox4) are increased in plants over‐expressing miR319. The miR319 over‐expression phenotype is suppressed by exogenous GA application and by a mutation in the PROCERA (PRO) gene, which encodes an inhibitor of the GA response. SlGA2ox4 is expressed in initiating leaflets during early leaf development. Its expression expands as a result of miR319 over‐expression, and its over‐expression leads to increased leaf complexity. These results suggest that LA activity is partly mediated by positive regulation of the GA response, probably by regulation of GA levels.
LATE, a C2H2 zinc‐finger protein that acts as floral repressor
Authors: Weingartner Magdalena , Subert Christa , Sauer Norbert
Published: July 2011

The transition from vegetative to generative development is a major developmental switch in flowering plants and is critical for reproductive success. This transition requires reprogramming of lateral primordia at the shoot apical meristem, which leads to the formation of determinate floral meristems instead of leaves. In Arabidopsis, flowering is induced by a network of interacting pathways. In the photoperiod‐dependent pathway, the two key elements mediating the effect of day length on flowering time are the transcription factors CONSTANS (CO) and the phloem mobile flowering signal FLOWERING LOCUS T (FT). Here, we identify a factor that is critically involved in this flowering response. The gene, which we named LATE FLOWERING (LATE), encodes a C2H2‐type zinc‐finger transcriptional regulator, and is expressed in the leaf vasculature and the vegetative shoot apical meristem. Ectopic expression of LATE in all tissues results in a dose‐dependent phenotype characterized by late flowering, altered floral organ identity and sterile flowers. Using tissue‐specific promoters, we further show that LATE controls the transition to flowering at two levels: first, it regulates the expression of flowering time genes in the leaf vasculature, and second, it interferes with floral meristem identity genes at the apex.
Skin disorders among travellers returning from tropical and non‐tropical countries consulting a travel medicine clinic
Authors: Herbinger K.‐H. , Siess C. , Nothdurft H. D. , von Sonnenburg F. , Löscher T.
Published: July 2011

Objective  To evaluate the causes and risks for imported skin disorders among travellers.

Methods  Data of 34 162 travellers returning from tropical and non‐tropical countries and presenting at the outpatient travel medicine clinic of the University of Munich, Germany, between 1999 and 2009 were analyzed for this study. Of these, 12.2% were diagnosed with skin disorders.

Results  Main destinations visited were Asia (40%), Africa (27%) and Latin America (21%). Tourism in the form of adventure travel/backpacking (47%) and package holidays (23%) was the most common purpose of travel. The leading causes of skin disorders were arthropodal (23%), bacterial (22%), helminthic (11%), protozoan (6%), viral (6%), allergic (5%) and fungal (4%). The 10 most frequently diagnosed specific skin diseases associated with specific destinations were insect bites (17%, Southern Europe), cutaneous larva migrans (8%, Asia and Latin America), cutaneous leishmaniasis (2.4%, Mediterranean Region/Middle East), dengue fever (1.5%, Asia), rickettsioses (1.3%, Southern Africa), myiasis (0.8%, Central America), filarioses (0.7%, Africa), tick bites (0.6%, Central/Eastern Europe), schistosomiasis (0.6%, Africa) and tungiasis (0.6%, Africa). Travellers in sub‐Saharan Africa had the highest relative risk of acquiring skin disorders.

Conclusion  As more than 20% of all skin disorders among returned travellers were caused by arthropods and about 50% by infectious pathogens, pre‐travel consultations should include specific prophylaxis and consider the most important risk factor for the travel destination.
Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes
Authors: Ruiz‐González I , Sánchez MA , García‐Fernández RA , García‐Palencia P , Sánchez B , Letelier CA , González‐Bulnes A , Flores JM
Published: July 2011

Contents

The objective of this study was to investigate differences on the endometrial immunoexpression of type I IFN receptor subunit 1 (IFNAR1) and oxytocin receptor (OTR) during the time of maternal recognition of pregnancy in sheep, when oestrus is synchronized with either prostaglandin analogues (group PG) or conventional progestagens (group P). Plasma progesterone was measured from day 0 to 21 post‐coitus (pc) (day 0 = day of oestrus). Immunohistochemistry was performed in samples of uterine horns from pregnant sheep on days 9pc, 13pc, 15pc, 17pc and 21pc to locate IFNAR1 and OTR expression in different endometrial compartments. Mean levels of plasma progesterone were different between treatments, obtaining higher levels in the PG group than in the P group (p < 0.05). Comparing days of pregnancy, IFNAR1 protein expression was different in the luminal epithelium (LE) (p < 0.05), while OTR was different in the LE and in the superficial glandular epithelium (SG) (p < 0.05). Temporal variation on the expression of both proteins from day 9pc to 21pc has been evidenced. IFNAR1 and OTR expression did not show significant differences between treatments. However, the response observed in the endometrium was highly inconsistent when prostaglandin analogues were used. Therefore, the protocol based on prostaglandin analogues still needs to be optimized before being considered as a better alternative to progestagens for oestrous synchronization in sheep.
Noonan syndrome
Authors: Turner Anne M
Published: July 2011

Noonan syndrome is a common autosomal dominant condition, readily recognisable in childhood. It is characterised by a pattern of typical facial dysmorphism and malformations including congenital cardiac defects, short stature, abnormal chest shape, broad or webbed neck, and a variable learning disability. Mildly affected adults may not be diagnosed until the birth of a more obviously affected child. The phenotype is highly variable. Important progress in understanding the molecular basis of this and other related conditions was made in 2001 when germline mutations in the PTPN11 gene were found to account for ∼50% of cases. Since then, mutations in additional genes in the rat sarcoma (RAS) pathway have been identified in a proportion of the remainder. Molecular confirmation of diagnosis is now possible for many families and has become increasingly important in guiding management. Increased awareness by paediatricians will lead to earlier diagnosis, and provide patients and their families with accurate genetic counselling, including options when planning pregnancy.
Management of children with Thrombocytopenia‐absent radius syndrome: An institutional experience
Authors: Coccia Paola , Ruggiero Antonio , Mastrangelo Stefano , Attinà Giorgio , Scalzone Maria , Pittiruti Mauro , Zampino Giuseppe , Maurizi Palma , Riccardi Riccardo
Published: July 2011

Aim:  Thrombocytopenia‐absent radius (TAR) syndrome is characterised by bilateral absence of the radii in the presence of both thumbs and hypomegakaryocytic thrombocytopenia.

We report our experience of three patients affected by TAR syndrome presenting with different clinical manifestations focusing on the management of these patients.

Methods and results:  We propose the use of long‐term central venous catheters to reduce discomfort because of repeated vein punctures in search for a venous access, rendered difficult by upper limbs abnormalities.

Conclusions:  It is important to improve the quality of life of affected patients.
Parents' search for evidence‐based practice: A personal story
Authors: Ben‐Sasson Ayelet
Published: July 2011

Many clients engage in an intense search for evidence related to the diagnosis, prognosis and intervention options of their (or their dependent's) health condition. A client‐based search for evidence poses challenges from a client and clinician perspective and evolves the client‐clinician relationship. This paper describes the meaning of searching for health evidence by health‐care clients such as parents of hospitalised children through a personal story. I discuss the subjective search for evidence‐based health information, interpretation and transfer of information as well as its impact on providers. In order to implement client‐centred care and evidence‐based practice health care organisations and providers need to take an active role in guiding clients in effective health information‐seeking behaviour and to develop mechanisms for processing evidence presented by clients.
Promoting mental health nursing: Employing undergraduate nursing students as assistants in mental health
Authors: Cleary Michelle , Horsfall Jan , Happell Brenda
Published: July 2011

The difficulty in attracting graduates of nursing programmes into mental health nursing (MHN) remains an ongoing challenge. Moreover, it is frequently claimed that undergraduate nursing students do not always regard MHN favourably for future employment. Although undergraduate nurses are employed as assistants in nursing (AIN) in mental health settings, there is no published research exploring their role, the career trajectory into MHN, or its effectiveness as a recruitment strategy. In this paper, we draw on the literature to delineate factors that might contribute to the desire of AIN to work in MHN. Nine factors were identified: acceptance by nurses, fitting in with the culture, managing the workload, developing a realistic appraisal of the effectiveness and limits of psychiatry, constructive learning from direct interpersonal interactions with clients, practising communication skills, being supported in a structured way, working with positive role models, and the overall quality of the employment setting. A comprehensive understanding of these factors can enhance the experience of undergraduate nursing students working as AIN, and potentially increase recruitment into MHN.
Urethral trauma. Part I: introduction, history, anatomy, pathology, assessment and emergency management
Authors: Mundy Anthony R. , Andrich Daniela E.
Published: July 2011

What’s known on the subject? and What does the study add?

Iatrogenic trauma aside, urethral injuries are not common. Nonetheless, there have been a large number of cohort studies, generally of small numbers of patients.

This review pulls together all of the information available to try and produce a coherent narrative.
Postoperative systems models more accurately predict risk of significant disease progression than standard risk groups and a 10‐year postoperative nomogram: potential impact on the receipt of adjuvant therapy after surgery
Authors: Donovan Michael J. , Khan Faisal M. , Powell Douglas , Bayer‐Zubek Valentina , Cordon‐Cardo Carlos , Costa Jose , Eastham James , Scardino Peter
Published: July 2011

Study Type – Prognostic (individual cohort)

Level of Evidence 2b

What's known on the subject? and What does the study add?

Physicians are becoming increasingly aware of the need to better understand adverse pathology (e.g. margin positive or extracapsular extension) post‐surgery. Systems models provide the necessary risk discriminatory tools to guide patient monitoring and decision‐making.

OBJECTIVE

To compare the performance of a systems‐based risk assessment tool with standard defined risk groups and the 10‐year postoperative nomogram for predicting disease progression, including biochemical relapse and clinical (systemic) failure.

PATIENTS AND METHODS

Clinical variables, biometric profiles and outcome results from a training cohort comprising 373 patients in a published postoperative systems‐based prognostic model were obtained.

Patients were stratified according to D'Amico standard risk groups, Kattan 10‐year postoperative nomogram and prognostic scores from the postoperative tissue model.

The association of pathological variables and calculated risk groups with biochemical recurrence and clinical (systemic) failure was assessed using the concordance index (C‐index) and hazard ratio (HR).

RESULTS

Systems‐based post‐prostatectomy models to predict significant disease progression (post‐treatment clinical failure) were more accurate than the D'Amico defined risk groups and the Kattan 10‐year postoperative nomogram (systems model: C‐index, 0.84; HR, 17.46; P < 0.001 vs D'Amico: C‐index, 0.73; HR, 11; P= 0.001; 10‐year nomogram: C‐index, 0.79; HR, 5.06; P < 0.001).

The systems models were also more accurate than standard risk groups for predicting prostate‐specific antigen recurrence (systems model: C‐index, 0.76; HR, 8.94; P < 0.001 vs D'Amico C‐ index, 0.70; HR, 4.67; P < 0.001) and showed incremental improvement over the 10‐year postoperative nomogram (C‐index, 0.75; HR, 5.83; P < 0.001).

The postoperative tissue model provided additional risk discrimination over surgical margin status and extracapsular extension for predicting disease outcome, and was most significant for the clinical (systemic) failure endpoint (surgical margin: C‐index, 0.58; HR, 1.57; P= 0.2; extracapsular extension: C‐index, 0.62; HR, 2.06; P= 0.04).

CONCLUSIONS

Risk assessment models that incorporate characteristics from the patient's own tumour specimen are more accurate than clinical‐only nomograms for predicting significant disease outcome.

Systems‐based tools should provide useful information concerning the appropriate receipt of adjuvant therapy in the post‐surgical setting.
Elevated physiological levels of folic acid can increase in vitro growth and invasiveness of prostate cancer cells
Authors: Petersen Lars F. , Brockton Nigel T. , Bakkar Ashraf , Liu Shuhong , Wen Jing , Weljie Aalim M. , Bismar Tarek A.
Published: July 2011

What's known on the subject? and What does the study add?

Evidence has emerged identifying folic acid supplementation as a potential risk factor for cancer development or progression. Long‐term folic acid supplementation has been shown to increase the risk of prostate cancer development by three‐fold. Sarcosine is a byproduct of folate metabolism and has been proposed as a biomarker for aggressive prostate cancer phenotypes.

We looked at the effects of physiologically relevant levels of folic acid on in vitro prostate cancer cell growth and invasion, and demonstrated that higher levels can have the effect of increasing both of these biological processes. We also show that these changes toward a more aggressive phenotype are not linked to increased sarcosine levels, however other metabolic pathways may be involved.

OBJECTIVES

To investigate the effects of different folic acid concentrations on the growth and invasiveness of prostate cancer cell lines.

To determine if observed changes are correlated with changes in levels of the potential prostate cancer biomarker, sarcosine, a byproduct of folate metabolism.

MATERIALS AND METHODS

The prostate cancer cell lines PC‐3, LNCaP and DU145 were cultured in media containing 4, 20 or 100 nm of folic acid and assayed for growth over 9 days by counting viable cells at 3‐day intervals, or for invasion by passage through a Matrigel‐coated transwell membrane.

Cells grown in the different folic acid media were collected and subjected to metabolomic analysis by gas chromatography and mass spectrometry to measure levels of intracellular sarcosine.

RESULTS

The results show that higher levels of folic acid can increase cell growth in PC‐3 and LNCaP prostate cancer cell lines, and may also increase the invasive capacity of PC‐3, LNCaP and DU145 cells.

We did not observe a correlation between increased invasion from higher folic acid concentrations and levels of sarcosine, but there were significant changes in other metabolites in cells grown in higher levels of folic acid.

CONCLUSION

These findings suggest that folic acid has an important and potentially negative role in prostate cancer progression.
What is the effect of climate change on marine fish biodiversity in an area of low connectivity, the Baltic Sea?
Authors: Hiddink Jan Geert , Coleby Chris
Published: July 2011

Aim  Climate change could result in an increase in species richness because large‐scale biogeography suggests that more species could be gained from equatorial regions than may be lost pole‐ward. However, the colonization of newly available habitat may lag behind the rate dictated by climatic warming if there exists of a lack of connectivity between ‘donor’ and receiving areas. The objective of this study was to compare how regional warming affected the biodiversity of marine fish in areas that differed in their connectivity in the Baltic Sea.

Location  North‐east Atlantic, Kattegat and Baltic Sea.

Methods  The total species richness and the mean species richness from scientific surveys were related to changes in temperature and salinity. Changes in the extent of the distribution of individual fish species were related to the latitudinal distribution, salinity tolerance, maximum body size and exploitation status to assess to what extent climate change and fishing impacts could explain changes in species richness in the Baltic.

Results  Rising temperatures in the well‐connected Kattegat correlated to an increase in the species richness of fish, due to an increase in low‐latitude species. Unexpectedly, species richness in the poorly connected Baltic Sea also increased. However, the increase seems to be related to higher salinity rather than temperature and there was no influx of low‐latitude species.

Main conclusions  These results do not support the hypothesis that low‐connectivity areas are less likely to see increases in species richness in response to warming. This indicates that the effect of climate change on biodiversity may be more difficult to predict in areas of low connectivity than in well‐connected areas.
An Energy‐Conserving Hair Reflectance Model
Authors: d'Eon Eugene , Francois Guillaume , Hill Martin , Letteri Joe , Aubry Jean‐Marie
Published: July 2011

We present a reflectance model for dielectric cylinders with rough surfaces such as human hair fibers. Our model is energy conserving and can evaluate arbitrarily many orders of internal reflection. Accounting for compression and contraction of specular cones produces a new longitudinal scattering function which is non‐Gaussian and includes an off‐specular peak. Accounting for roughness in the azimuthal direction leads to an integral across the hair fiber which is efficiently evaluated using a Gaussian quadrature. Solving cubic equations is avoided, caustics are included in the model in a consistent fashion, and more accurate colors are predicted by considering many internal pathways.
Stratified Sampling for Stochastic Transparency
Authors: Laine Samuli , Karras Tero
Published: July 2011

The traditional method of rendering semi‐transparent surfaces using alpha blending requires sorting the surfaces in depth order. There are several techniques for order‐independent transparency, but most require either unbounded storage or can be fragile due to forced compaction of information during rendering. Stochastic transparency works in a fixed amount of storage and produces results with the correct expected value. However, carelessly chosen sampling strategies easily result in high variance of the final pixel colors, showing as noise in the image. In this paper, we describe a series of improvements to stochastic transparency that enable stratified sampling in both spatial and alpha domains. As a result, the amount of noise in the image is significantly reduced, while the result remains unbiased.
Efficient Computation of Blue Noise Point Sets through Importance Sampling
Authors: Kalantari Nima Khademi , Sen Pradeep
Published: July 2011

Dart‐throwing can generate ideal Poisson‐disk distributions with excellent blue noise properties, but is very computationally expensive if a maximal point set is desired. In this paper, we observe that the Poisson‐disk sampling problem can be posed in terms of importance sampling by representing the available space to be sampled as a probability density function (pdf). This allows us to develop an efficient algorithm for the generation of maximal Poisson‐disk distributions with quality similar to naïve dart‐throwing but without rejection of samples. In our algorithm, we first position samples in one dimension based on its marginal cumulative distribution function (cdf). We then throw samples in the other dimension only in the regions which are available for sampling. After each 2D sample is placed, we update the cdf and data structures to keep track of the available regions. In addition to uniform sampling, our method is able to perform variable‐density sampling with small modifications. Finally, we also propose a new min‐conflict metric for variable‐density sampling which results in better adaptation of samples to the underlying importance field.
Silhouette‐Aware Warping for Image‐Based Rendering
Authors: Chaurasia Gaurav , Sorkine Olga , Drettakis George
Published: July 2011

Image‐based rendering (IBR) techniques allow capture and display of 3D environments using photographs. Modern IBR pipelines reconstruct proxy geometry using multi‐view stereo, reproject the photographs onto the proxy and blend them to create novel views. The success of these methods depends on accurate 3D proxies, which are difficult to obtain for complex objects such as trees and cars. Large number of input images do not improve reconstruction proportionally; surface extraction is challenging even from dense range scans for scenes containing such objects. Our approach does not depend on dense accurate geometric reconstruction; instead we compensate for sparse 3D information by variational image warping. In particular, we formulate silhouette‐aware warps that preserve salient depth discontinuities. This improves the rendering of difficult foreground objects, even when deviating from view interpolation. We use a semi‐automatic step to identify depth discontinuities and extract a sparse set of depth constraints used to guide the warp. Our framework is lightweight and results in good quality IBR for previously challenging environments.
ManyLoDs: Parallel Many‐View Level‐of‐Detail Selection for Real‐Time Global Illumination
Authors: Hollander Matthias , Ritschel Tobias , Eisemann Elmar , Boubekeur Tamy
Published: July 2011

Level‐of‐Detail structures are a key component for scalable rendering. Built from raw 3D data, these structures are often defined as Bounding Volume Hierarchies, providing coarse‐to‐fine adaptive approximations that are well‐adapted for many‐view rasterization. Here, the total number of pixels in each view is usually low, while the cost of choosing the appropriate LoD for each view is high. This task represents a challenge for existing GPU algorithms. We propose ManyLoDs, a new GPU algorithm to efficiently compute many LoDs from a Bounding Volume Hierarchy in parallel by balancing the workload within and among LoDs. Our approach is not specific to a particular rendering technique, can be used on lazy representations such as polygon soups, and can handle dynamic scenes. We apply our method to various many‐view rasterization applications, including Instant Radiosity, Point‐Based Global Illumination, and reflection/refraction mapping. For each of these, we achieve real‐time performance in complex scenes at high resolutions.
Anaglyph Stereo Without Ghosting
Authors: Sanftmann H. , Weiskopf D.
Published: July 2011

Anaglyph stereo provides a low‐budget solution to viewing stereoscopic images. However, it may suffer from ghosting and bad color reproduction. Here we address the first issue. We present a novel technique to perceptually calibrate an anaglyph stereoscopic system and to use the calibration to eliminate ghosting from the anaglyph image. We build a model based on luminance perception by the left and right eyes through the anaglyph glasses. We do not rely on power spectra of a monitor or on transmission spectra of anaglyph glasses, but show how the five parameters of our model can be captured with just a few measurements within a minute. We present how full color, half color, and gray anaglyphs can be rendered with our technique and compare them to the traditional method.
A Physically Plausible Model for Light Emission from Glowing Solid Objects
Authors: Wilkie A. , Weidlich A.
Published: July 2011

The emissive properties of glowing solid objects appear to be something that the graphics community has not considered in depth before. While the volumetric emission of plasma, i.e. flames, has been discussed numerous times, and while the emission characteristics of entire luminaires can be handled via IESNA profiles, the exact appearance of glowing solid objects appears to have eluded detailed scrutiny so far. In this paper, we discuss the theoretical background to thermally induced light emission of objects, describe how one can handle this behaviour with very little effort in a physically based rendering system, and provide examples for the visual importance of handling this in a plausible fashion.
Variable Bit Rate GPU Texture Decompression
Authors: Olano M. , Baker D. , Griffin W. , Barczak J.
Published: July 2011

Variable bit rate compression can achieve better quality and compression rates than fixed bit rate methods. None the less, GPU texturing uses lossy fixed bit rate methods like DXT to allow random access and on‐the‐fly decompression during rendering. Changes in games and GPUs since DXT was developed make its compression artifacts less acceptable, and texture bandwidth less of an issue, but texture size is a serious and growing problem. Games use a large total volume of texture data, but have a much smaller active set. We present a new paradigm that separates GPU decompression from rendering. Rendering is from uncompressed data, avoiding the need for random access decompression. We demonstrate this paradigm with a new variable bit rate lossy texture compression algorithm that is well suited to the GPU, including a new GPU‐friendly formulation of range decoding, and a new texture compression scheme averaging 12.4:1 lossy compression ratio on 471 real game textures with a quality level similar to traditional DXT compression. The total game texture set are stored in the GPU in compressed form, and decompressed for use in a fraction of a second per scene.
Efficient Packing of Arbitrary Shaped Charts for Automatic Texture Atlas Generation
Authors: Nöll T. , Strieker D.
Published: July 2011

Texture atlases are commonly used as representations for mesh parameterizations in numerous applications including texture and normal mapping. Therefore, packing is an important post‐processing step that tries to place and orient the single parameterizations in a way that the available space is used as efficiently as possible. However, since packing is NP hard, only heuristics can be used in practice to find near‐optimal solutions. In this publication we introduce the new search space of modulo valid packings. The key idea thereby is to allow the texture charts to wrap around in the atlas. By utilizing this search space we propose a new algorithm that can be used in order to automatically pack texture atlases. In the evaluation section we show that our algorithm achieves solutions with a significantly higher packing efficiency when compared to the state of the art, especially for complex packing problems.
Least Squares Vertex Baking
Authors: Kavan L. , Bargteil A.W. , Sloan P.‐P.
Published: July 2011

We investigate the representation of signals defined on triangle meshes using linearly interpolated vertex attributes. Compared to texture mapping, storing data only at vertices yields significantly lower memory overhead and less expensive runtime reconstruction. However, standard approaches to determine vertex values such as point sampling or averaging triangle samples lead to suboptimal approximations. We discuss how an optimal solution can be efficiently calculated using continuous least‐squares. In addition, we propose a regularization term that allows us to minimize gradient discontinuities and mach banding artifacts while staying close to the optimum. Our method has been integrated in a game production lighting tool and we present examples of representing signals such as ambient occlusion and precomputed radiance transfer in real game scenes, where vertex baking was used to free up resources for other game components.
Direct Ray Tracing of Phong Tessellation
Authors: Ogaki Shinji , Tokuyoshi Yusuke
Published: July 2011

There are two major ways of calculating ray and parametric surface intersections in rendering. The first is through the use of tessellated triangles, and the second is to use parametric surfaces together with numerical methods such as Newton's method. Both methods are computationally expensive and complicated to implement. In this paper, we focus on Phong Tessellation and introduce a simple direct ray tracing method for Phong Tessellation. Our method enables rendering smooth surfaces in a computationally inexpensive yet robust way.
A Ray Tracing Approach to Diffusion Curves
Authors: Bowers John C. , Leahey Jonathan , Wang Rui
Published: July 2011

Diffusion curves [OBW*08] provide a flexible tool to create smooth‐shaded images from curves defined with colors. The resulting image is typically computed by solving a Poisson equation that diffuses the curve colors to the interior of the image. In this paper we present a new method for solving diffusion curves by using ray tracing. Our approach is analogous to final gathering in global illumination, where the curves define source radiance whose visible contribution will be integrated at a shading pixel to produce a color using stochastic ray tracing. Compared to previous work, the main benefit of our method is that it provides artists with extended flexibility in achieving desired image effects. Specifically, we introduce generalized curve colors called shaders that allow for the seamless integration of diffusion curves with classic 2D graphics including vector graphics (e.g. gradient fills) and raster graphics (e.g. patterns and textures). We also introduce several extended curve attributes to customize the contribution of each curve. In addition, our method allows any pixel in the image to be independently evaluated, without having to solve the entire image globally (as required by a Poisson‐based approach). Finally, we present a GPU‐based implementation that generates solution images at interactive rates, enabling dynamic curve editing. Results show that our method can easily produce a variety of desirable image effects.
Coherent Out‐of‐Core Point‐Based Global Illumination
Authors: Kontkanen Janne , Tabellion Eric , Overbeck Ryan S.
Published: July 2011

We describe a new technique for coherent out‐of‐core point‐based global illumination and ambient occlusion. Point‐based global illumination (PBGI) is used in production to render tremendously complex scenes, so in‐core storage of point and octree data structures quickly becomes a problem. However, a simple out‐of‐core extension of a classical top‐down octree building algorithm would be extremely inefficient due to large amount of I/O required. Our method extends previous PBGI algorithms with an out‐of‐core technique that uses minimal I/O and stores data on disk compactly and in coherent chunks for later access during shading. Using properties of a space‐filling Z‐curve, we are able to preprocess the data in two passes: an external ID‐sort and an octree construction pass.
Guided Image Filtering for Interactive High‐quality Global Illumination
Authors: Bauszat Pablo , Eisemann Martin , Magnor Marcus
Published: July 2011

Interactive computation of global illumination is a major challenge in current computer graphics research. Global illumination heavily affects the visual quality of generated images. It is therefore a key attribute for the perception of photo‐realistic images. Path tracing is able to simulate the physical behaviour of light using Monte Carlo techniques. However, the computational burden of this technique prohibits interactive rendering times on standard commodity hardware in high‐quality. Trying to solve the Monte Carlo integration with fewer samples results in characteristic noisy images. Global illumination filtering methods take advantage of the fact that the integral for neighbouring pixels may be very similar. Averaging samples of similar characteristics in screen‐space may approximate the correct integral, but may result in visible outliers. In this paper, we present a novel path tracing pipeline based on an edge‐aware filtering method for the indirect illumination which produces visually more pleasing results without noticeable outliers. The key idea is not to filter the noisy path traced images but to use it as a guidance to filter a second image composed from characteristic scene attributes that do not contain noise by default. We show that our approach better approximates the Monte Carlo integral compared to previous methods. Since the computation is carried out completely in screen‐space it is therefore applicable to fully dynamic scenes, arbitrary lighting and allows for high‐quality path tracing at interactive frame rates on commodity hardware.
Global versus Low Carbon Economy: The Case of the Revised EU Emissions Trading Scheme
Authors: Ahner Nicole , Meeus Leonardo
Published: July 2011

Europe is tightening its climate change policy and with that its pollution control legislation, supposedly to lead the way towards a low carbon economy. As the rest of the world is lagging behind in greenhouse gas emission reduction efforts, this causes increasing concern for the European carbon‐intensive industry. In order to address concerns of economic competitiveness and emission leakage, the EU is considering the extension of its recently revised EU Emission Trading Scheme on carbon‐intensive goods imported from countries not taking comparable action to reduce their emissions. This article examines the permissibility of such an extension under the law of the World Trade Organization, namely the General Agreement of Tariffs and Trade (1994).
Carbon Leakage – The First Mover Disadvantage: Australia's Trade‐Related Assistance Measures for Emissions‐Intensive, Trade‐Exposed Industries
Authors: Haywood Caroline
Published: July 2011

As developed countries adopt climate change mitigation measures ahead of others, they fear ‘carbon leakage’: relocation of their emissions‐intensive trade‐exposed (EITE) industries to countries without climate regimes. The Australian Government will provide a percentage of emission allowances for free to eligible EITE industries under its emissions trading scheme. This article examines the compatibility of these measures with Australia's obligations under the General Agreement on Tariffs and Trade and Agreement on Subsidies and Countervailing Measures. Ultimately, these measures are held likely to be consistent with World Trade Organization rules, proving that the ‘first mover’ disadvantage of carbon leakage can be overcome.
Sealing the Deal: Environmental and Indigenous Justice and Mining in Nunavut1
Authors: Bowman Laura
Published: July 2011

Nunavut is a territory in Canada's Eastern Arctic inhabited by a majority Inuit population. This population continues to rely on wildlife as a food source, and on harvesting for both cultural and economic well‐being. Increased mining investment in Nunavut has resulted in a diminishment of public hearing opportunities for individual Inuk and other residents of Nunavut in non‐renewable resource decisions that will affect harvesters. This represents a substantial erosion of the participatory rights the Inuit agreed to when they ratified the Nunavut Land Claims Agreement in 1993.
Reconciliation, Indigenous Rights and Offshore Oil and Gas Development in the Canadian Arctic
Authors: Manley‐Casimir Kirsten
Published: July 2011

In this article, the author addresses the potential impacts of Arctic offshore oil and gas development on Indigenous communities who reside in northern Canada. She argues that the potential environmental, social and cultural harms of such development may disproportionately affect such Indigenous communities. Relying on Canadian jurisprudence, she suggests that the principle of reconciliation may help mitigate the negative impacts of the development of Arctic offshore oil and gas resources. A fulsome conception of reconciliation supports meaningful consultation, efforts to substantially address Indigenous concerns, and ongoing collaborative negotiations in the context of offshore oil and gas development in the Arctic.
Arctic Bottom Trawling in Canadian Waters: Exploring the Possibilities for Legal Action against Unsustainable Fishing
Authors: Church Rebekah
Published: July 2011

As sea ice coverage decreases in the Arctic, previously inaccessible areas are becoming more attractive to commercial fishing. This article outlines the current state of bottom trawling in the Canadian Arctic. It examines how commercial fishing is regulated in the region and analyzes whether opportunities exist for judicially challenging the issuance of regulatory permits for Arctic trawling. The regulation of Arctic bottom trawling suggests that any decision to allow more extensive trawling operations will take place at the policy level, making court proceedings questioning the validity of such decisions challenging.
‘Th'ancient Distaff’ and ‘Whirling Spindle’: measuring the contribution of spinning to household earnings and the national economy in England, 1550–17701
Authors: MULDREW CRAIG
Published: July 2011

The purpose of this article is to estimate the workforce involved in spinning from the late sixteenth century until the eve of mechanization. In addition, the potential contribution to family earnings from spinning will be examined. Just about all of the millions of yards of woollen yarn that went into making English cloth had to be spun by women and children, but this activity has not been investigated to the extent that it deserves. Spinning was a skilled occupation where there was a great demand for the best quality product. Sources exist which make it possible to make general estimates of the amount of spinning needed in the economy, and its cost. This evidence shows that employment in spinning increased dramatically from the late seventeenth century, and continued to increase until there were probably over one million women and children employed in spinning by the mid‐eighteenth century. In addition earnings increased to the extent whereby earnings from spinning could contribute over 30 per cent of household income for poorer families. This has implications for looking at trends in real wages over time, as well as for the concept of the industrious revolution.
Entrepreneurs, formalization of social ties, and trustbuilding in Europe (fourteenth to twentieth centuries)1
Authors: ALFANI GUIDO , GOURDON VINCENT
Published: July 2011

The establishment of trust is a key component of economic activity and social ties can make business dealings work better. However, we do not know much about how economic actors created new social ties deliberately in order to pursue their objectives. This article analyses the way in which merchants and entrepreneurs used specific rituals to establish formal social ties, with the intent of protecting their business relationships. It focuses on relational instruments that until now had been neglected, particularly godparenthood and marriage witnessing. It shows that formalization, ritualization, and publicity of ties were used by entrepreneurs to establish trust with their business associates, for example when information was asymmetric or when institutions were perceived as inefficient in guaranteeing mutual good behaviour. The analysis covers a long period, from the late middle ages to today. It pays particular attention to the consequences of the Reformation in the sixteenth and seventeenth centuries and of the industrial revolution in the nineteenth. Contrary to the received wisdom, it suggests that formal social ties such as godparenthood continued to play an important role in economic activity during and after the industrial revolution. New databases on early modern Italy and nineteenth‐century France are used.
Serum and CSF PDGF‐AA and FGF‐2 in relapsing‐remitting multiple sclerosis: a case–control study
Authors: Harirchian M. H. , Tekieh A. H. , Modabbernia A. , Aghamollaii V. , Tafakhori A. , Ghaffarpour M. , Sahraian M. A. , Naji M. , Yazdanbakhsh M.
Published: July 2011

Background and purpose:  Fibroblast growth factor‐2 (FGF‐2) and platelet‐derived growth factor‐A (PDGF‐AA) are potent modulators of oligodendrocytes, the main responsible cells for myelin regeneration. We measured FGF‐2 and PDGF‐AA in the sera and cerebrospinal fluid (CSF) of patients with relapsing‐remitting multiple sclerosis (RR‐MS) and compared these values with control subjects.

Methods:  Twenty‐three patients with RR‐MS and 23 subjects without inflammatory and demyelinating diseases were included. Serum samples of the patients were collected in both relapse and remission phases and were analyzed with ELISA method. CSF was drawn during the relapse period. Blood and CSF were drawn from control subjects for comparison. Wilcoxon and Mann–Whitney U‐test and Spearman’s rank correlation were used for analysis. P values of <0.05 were considered significant.

Results:  Age and sex distribution were similar in both groups. Serum values of FGF‐2 were higher in relapse phase compared with remission phase, with a trend toward significance (P = 0.052). CSF PDGF‐AA showed significant negative correlation with disease duration (correlation coefficient = −0.58, P = 0.004). Serum levels of PDGF did not differ between two phases significantly. There was no difference in serum and CSF values of these factors between patients and controls. When we compared patients with prolonged disease with controls, a significant difference between the CSF levels of PDGF‐AA was observed (mean ± SEM 2.78 ± 0.8 in controls vs. 0.55 ± 0.29 in patients with MS ≥ 2 years, P < 0.05).

Conclusion:  Our study was the first to show that CSF PDGF‐AA is related to disease duration. Supporting previous findings we showed that serum and CSF levels of these factors are weak indicators of disease severity.
A comprehensive investigation of memory impairment in attention deficit hyperactivity disorder and oppositional defiant disorder
Authors: Rhodes Sinéad M. , Park Joanne , Seth Sarah , Coghill David R.
Published: July 2011

Background:  We conducted a comprehensive and systematic assessment of memory functioning in drug‐naïve boys with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD).

Methods:  Boys performed verbal and spatial working memory (WM) component (storage and central executive) and verbal and spatial storage load tasks, and the spatial span, spatial executive WM, spatial recognition memory and verbal recognition memory tasks from the Cambridge Neuropsychological Test Automated Battery. Groups comprised: (a) ADHD only (N = 21); (b) ADHD+ODD (N = 27); (c) ODD only (N = 21); and (d) typically developing (TYP) boys (N = 26). Groups were matched for age (M = 9.7 years) and sex (all boys).

Results:  Confirmatory factor analyses confirmed the presence of five factors: verbal functioning, spatial functioning, WM storage, WM central executive and long‐term memory (LTM). All three clinical groups demonstrated impaired memory performance. Boys with ODD and ODD+ADHD but not ADHD alone performed poorly on verbal memory tasks, whilst all three clinical groups showed impaired performance on spatial memory tasks. All three clinical groups performed poorly on the storage and central executive WM factors and the LTM factor.

Conclusions:  ADHD and ODD are characterised by impaired performance storage and central executive WM tasks and LTM tasks. This is, we believe, the first report of impaired WM and LTM performance in ODD. This study suggests that verbal memory difficulties are more closely associated with ODD than ADHD symptoms and that combined ADHD+ODD represents a true comorbidity. The data also support a small but growing number of suggestions in the literature of impaired LTM in ADHD.