bluuebunny/crossref_metadata_2025 huggingface dataset:
Ocean Warming Slows Coral Growth in the Central Red Sea
Authors: Cantin Neal E. , Cohen Anne L. , Karnauskas Kristopher B. , Tarrant Ann M. , McCorkle Daniel C.
Published: July 2010

Red Sea Coral Decline

Large, rapid sea surface temperature rises of 1°C or greater typically cause bleaching of corals.

Cantin
et al.

(p.
322
) show that smaller temperature increases also have detrimental effects on corals, dramatically reducing their rates of calcification and skeletal extension. Corals in the Red Sea, where water temperatures have risen by 0.4 to 1°C since the mid-1970s, have declined in skeletal extension by about 30%, and decreased in calcification rates by around 18% since 1998. This finding suggests that we may see an end to coral growth in the Red Sea this century.
Cenozoic Tectonics of Western North America Controlled by Evolving Width of Farallon Slab
Authors: Schellart W. P. , Stegman D. R. , Farrington R. J. , Freeman J. , Moresi L.
Published: July 2010

Cenozoic Tectonics

The Basin and Range Province of western North America—exemplified by the alternating mountain ridge and valley landscapes across nearly the entire U.S. state of Nevada—started to form ∼50 million years ago through a series of extensions of the continental crust. Prior to that, massive mountain-building collisions at the boundary between North America and the Pacific Ocean formed a subduction zone and compressed the continent. By combining observations of global subduction zone velocities with numerical modeling,

Schellart
et al.

(p.
316
) demonstrate that the thinning of the subducting portion of the oceanic plate controlled how and when the transition from compression to extension occurred. Even today, where the much smaller remnant oceanic plate continues to slowly subduct below North America in the Pacific Northwest, the width of the slab and not its age controls the velocity of subduction. Indeed, this relation may explain the dynamics of other modern subduction zones, from South America to Japan.
Reengineering Enzymes
Authors: Lutz Stefan
Published: July 2010

First-principles design and directed evolution expand the role of enzymes in chemical synthesis.
Association of Trypanolytic ApoL1 Variants with Kidney Disease in African Americans
Authors: Genovese Giulio , Friedman David J. , Ross Michael D. , Lecordier Laurence , Uzureau Pierrick , Freedman Barry I. , Bowden Donald W. , Langefeld Carl D. , Oleksyk Taras K. , Uscinski Knob Andrea L. , Bernhardy Andrea J. , Hicks Pamela J. , Nelson George W. , Vanhollebeke Benoit , Winkler Cheryl A. , Kopp Jeffrey B. , Pays Etienne , Pollak Martin R.
Published: July 2010

Out of Africa

Kidney disease is more common in African Americans than in Americans of European descent, and genetics is likely to be a major contributing factor.

Genovese
et al.

(p.
841
, published online 15 July) now show that African Americans who carry specific sequence variants in a gene on chromosome 22 encoding apolipoprotein L-1 (APOL1) have an increased risk of developing hypertension-attributed end-stage kidney disease or focal segmental glomerulosclerosis. These variants are absent from European chromosomes. Among the functions ascribed to APOL1 is the ability to lyse and kill trypanosomes. Intriguingly, APOL1 derived from the risk alleles, but not the “wild-type” allele, killed
Trypanosoma brucei rhodesiense
, which causes African sleeping sickness.
Kidney Disease Is Parasite-Slaying Protein's Downside
Authors: Leslie Mitch
Published: July 2010

Researchers describe two Jekyll-and-Hyde genetic variations online in
Science
this week that can lead to kidney shutdown but may also fend off a microorganism that causes sleeping sickness in thousands of people in Africa.
New Biosecurity Rules to Target the Riskiest Pathogens
Authors: Bhattacharjee Yudhijit
Published: July 2010

An executive order issued by President Barack Obama earlier this month indicates that the regulations on so-called select agents may end up more streamlined and less burdensome.
Probing Culture's Secrets, From Capuchins to Children
Authors: Balter Michael
Published: July 2010

At a recent meeting on how culture, usually defined as the passing on of traditions by learning from others, arises and changes, researchers probed questions such as what sparks cultural trends and how complex traditions are transmitted.
From the Outside Looking In
Authors: Mervis Jeffrey
Published: July 2010

A new push to get scientists into the classroom began with the best of intentions. But that's not always enough, say those involved with the D.C. public schools.
Rolling the Dice
Authors: Mervis Jeffrey
Published: July 2010

Retired statistician Eva Jacobs uses dice to show a sixth-grade math class that what they are learning about probability has real-world applications--and also that math can be fun.
Let's Have the Kids Judge
Authors: Mervis Jeffrey
Published: July 2010

Kids Judge! is a science fair that goes the other way: Researchers explain their work to fourth-grade students.
Microneedle Delivery of H5N1 Influenza Virus-Like Particles to the Skin Induces Long-Lasting B- and T-Cell Responses in Mice
Authors: Song Jae-Min , Kim Yeu-Chun , Lipatov Aleksandr S. , Pearton Marc , Davis C. Todd , Yoo Dae-Goon , Park Kyoung-Mi , Chen Li-Mei , Quan Fu-Shi , Birchall James C. , Donis Ruben O. , Prausnitz Mark R. , Compans Richard W. , Kang Sang-Moo
Published: July 2010

A simple method suitable for self-administration of vaccine would improve mass immunization, particularly during a pandemic outbreak. Influenza virus-like particles (VLPs) have been suggested as promising vaccine candidates against potentially pandemic influenza viruses, as they confer long-lasting immunity but are not infectious. We investigated the immunogenicity and protective efficacy of influenza H5 VLPs containing the hemagglutinin (HA) of A/Vietnam/1203/04 (H5N1) virus delivered into the skin of mice using metal microneedle patches and also studied the response of Langerhans cells in a human skin model. Prime-boost microneedle vaccinations with H5 VLPs elicited higher levels of virus-specific IgG1 and IgG2a antibodies, virus-specific antibody-secreting cells, and cytokine-producing cells up to 8 months after vaccination compared to the same antigen delivered intramuscularly. Both prime-boost microneedle and intramuscular vaccinations with H5 VLPs induced similar hemagglutination inhibition titers and conferred 100% protection against lethal challenge with the wild-type A/Vietnam/1203/04 virus 16 weeks after vaccination. Microneedle delivery of influenza VLPs to viable human skin using microneedles induced the movement of CD207+Langerhans cells toward the basement membrane. Microneedle vaccination in the skin with H5 VLPs represents a promising approach for a self-administered vaccine against viruses with pandemic potential.
Development and Application of Multiprobe Real-Time PCR Method Targeting the
hsp65
Gene for Differentiation of
Mycobacterium
Species from Isolates and Sputum Specimens
Authors: Kim Kijeong , Lee Hyungki , Lee Mi-Kyung , Lee Seoung-Ae , Shim Tae-Sun , Lim Seong Yong , Koh Won-Jung , Yim Jae-Joon , Munkhtsetseg Bazarragchaa , Kim Wonyong , Chung Sang-In , Kook Yoon-Hoh , Kim Bum-Joon
Published: July 2010

We developed a multiprobe real-time PCR assay targeting
hsp65
(HMPRT-PCR) to detect and identify mycobacterial isolates and isolates directly from sputum specimens. Primers and probes for HMPRT-PCR were designed on the basis of the
hsp65
gene sequence, enabling the recognition of seven pathogenic mycobacteria, including
Mycobacterium tuberculosis
,
M. avium
,
M. intracellulare
,
M. kansasii
,
M. abscessus
,
M. massiliense
, and
M. fortuitum.
This technique was applied to 24 reference and 133 clinical isolates and differentiated between all strains with 100% sensitivity and specificity. Furthermore, this method was applied to sputum specimens from 117 consecutive smear-positive patients with smear results of from a trace to 3+. These results were then compared to those obtained using the
rpoB
PCR-restriction analysis method with samples from cultures of the same sputum specimens. The HMPRT-PCR method correctly identified the mycobacteria in 89 samples (76.0%, 89/117), and moreover, the sensitivity level was increased to 94.3% (50/53) for sputa with an acid-fast bacillus score equal to or greater than 2+. Our data suggest that this novel HMPRT-PCR method could be a promising approach for detecting pathogenic mycobacterial species from sputum samples and culture isolates routinely in a clinical setting.
TMPRSS2 and TMPRSS4 Facilitate Trypsin-Independent Spread of Influenza Virus in Caco-2 Cells
Authors: Bertram Stephanie , Glowacka Ilona , Blazejewska Paulina , Soilleux Elizabeth , Allen Paul , Danisch Simon , Steffen Imke , Choi So-Young , Park Youngwoo , Schneider Heike , Schughart Klaus , Pöhlmann Stefan
Published: July 2010

Proteolysis of influenza virus hemagglutinin by host cell proteases is essential for viral infectivity, but the proteases responsible are not well defined. Recently, we showed that engineered expression of the type II transmembrane serine proteases (TTSPs) TMPRSS2 and TMPRSS4 allows hemagglutinin (HA) cleavage. Here we analyzed whether TMPRSS2 and TMPRSS4 are expressed in influenza virus target cells and support viral spread in the absence of exogenously added protease (trypsin). We found that transient expression of TMPRSS2 and TMPRSS4 resulted in HA cleavage and trypsin-independent viral spread. Endogenous expression of TMPRSS2 and TMPRSS4 in cell lines correlated with the ability to support the spread of influenza virus in the absence of trypsin, indicating that these proteases might activate influenza virus in naturally permissive cells. Indeed, RNA interference (RNAi)-mediated knockdown of both TMPRSS2 and TMPRSS4 in Caco-2 cells, which released fully infectious virus without trypsin treatment, markedly reduced the spread of influenza virus, demonstrating that these proteases were responsible for efficient proteolytic activation of HA in this cell line. Finally, TMPRSS2 was found to be coexpressed with the major receptor determinant of human influenza viruses, 2,6-linked sialic acids, in human alveolar epithelium, indicating that viral target cells in the human respiratory tract express TMPRSS2. Collectively, our results point toward an important role for TMPRSS2 and possibly TMPRSS4 in influenza virus replication and highlight the former protease as a potential therapeutic target.
Yellow Fever Virus Maintenance in Trinidad and Its Dispersal throughout the Americas
Authors: Auguste Albert J. , Lemey Philippe , Pybus Oliver G. , Suchard Marc A. , Salas Rosa Alba , Adesiyun Abiodun A. , Barrett Alan D. , Tesh Robert B. , Weaver Scott C. , Carrington Christine V. F.
Published: July 2010

Trinidad, like many other American regions, experiences repeated epizootics of yellow fever virus (YFV). However, it is unclear whether these result from
in situ
evolution (enzootic maintenance) or regular reintroduction of YFV from the South American mainland. To discriminate between these hypotheses, we carried out a Bayesian phylogeographic analysis of over 100 prM/E gene sequences sampled from 8 South American countries. These included newly sequenced isolates from the recent 2008-2009 Trinidad epizootic and isolates derived from mainland countries within the last decade. The results indicate that the most recent common ancestor of the 2008-2009 epizootic existed in Trinidad 4.2 years prior to 2009 (95% highest probability density [HPD], 0.5 to 9.0 years). Our data also suggest a Trinidad origin for the progenitor of the 1995 Trinidad epizootic and support
in situ
evolution of YFV between the 1979 and 1988-1989 Trinidad epizootics. Using the same phylogeographic approach, we also inferred the historical spread of YFV in the Americas. The results suggest a Brazilian origin for YFV in the Americas and an overall dispersal rate of 182 km/year (95% HPD, 52 to 462 km/year), with Brazil as the major source population for surrounding countries. There is also strong statistical support for epidemiological links between four Brazilian regions and other countries. In contrast, while there were well-supported epidemiological links within Peru, the only statistically supported external link was a relatively weak link with neighboring Bolivia. Lastly, we performed a complete analysis of the genome of a newly sequenced Trinidad 2009 isolate, the first complete genome for a genotype I YFV isolate.
Interaction of the Papillomavirus E8∧E2C Protein with the Cellular CHD6 Protein Contributes to Transcriptional Repression
Authors: Fertey Jasmin , Ammermann Ingo , Winkler Michael , Stöger Reinhard , Iftner Thomas , Stubenrauch Frank
Published: July 2010

Expression of the E6 and E7 oncogenes of high-risk human papillomaviruses (HPV) is controlled by cellular transcription factors and by viral E2 and E8∧E2C proteins, which are both derived from the HPV E2 gene. Both proteins bind to and repress the HPV E6/E7 promoter. Promoter inhibition has been suggested to be due to binding site competition with cellular transcription factors and to interactions of different cellular transcription modulators with the different amino termini of E2 and E8∧E2C. We have now identified the cellular chromodomain helicase DNA binding domain 6 protein (CHD6) as a novel interactor with HPV31 E8∧E2C by using yeast two-hybrid screening. Pull-down and coimmunoprecipitation assays indicate that CHD6 interacts with the HPV31 E8∧E2C protein via the E2C domain. This interaction is conserved, as it occurs also with the E8∧E2C proteins expressed by HPV16 and -18 and with the HPV31 E2 protein. Both RNA knockdown experiments and mutational analyses of the E2C domain suggest that binding of CHD6 to E8∧E2C contributes to the transcriptional repression of the HPV E6/E7 oncogene promoter. We provide evidence that CHD6 is also involved in transcriptional repression but not activation by E2. Taken together our results indicate that the E2C domain not only mediates specific DNA binding but also has an additional role in transcriptional repression by recruitment of the CHD6 protein. This suggests that repression of the E6/E7 promoter by E2 and E8∧E2C involves multiple interactions with host cell proteins through different protein domains.
The Human Papillomavirus Type 16 E6 Oncoprotein Activates mTORC1 Signaling and Increases Protein Synthesis
Authors: Spangle Jennifer M. , Münger Karl
Published: July 2010

The mammalian target of rapamycin (mTOR) kinase acts as a cellular rheostat that integrates signals from a variety of cellular signal transduction pathways that sense growth factor and nutrient availability as well as intracellular energy status. It was previously reported that the human papillomavirus type 16 (HPV16) E6 oncoprotein may activate the S6 protein kinase (S6K) through binding and E6AP-mediated degradation of the mTOR inhibitor tuberous sclerosis complex 2 (TSC2) (Z. Lu, X. Hu, Y. Li, L. Zheng, Y. Zhou, H. Jiang, T. Ning, Z. Basang, C. Zhang, and Y. Ke, J. Biol. Chem. 279:35664-35670, 2004; L. Zheng, H. Ding, Z. Lu, Y. Li, Y. Pan, T. Ning, and Y. Ke, Genes Cells 13:285-294, 2008). Our results confirmed that HPV16 E6 expression causes an increase in mTORC1 activity through enhanced phosphorylation of mTOR and activation of downstream signaling pathways S6K and eukaryotic initiation factor binding protein 1 (4E-BP1). However, we did not detect a decrease in TSC2 levels in HPV16 E6-expressing cells. We discovered, however, that HPV16 E6 expression causes AKT activation through the upstream kinases PDK1 and mTORC2 under conditions of nutrient deprivation. We show that HPV16 E6 expression causes an increase in protein synthesis by enhancing translation initiation complex assembly at the 5′ mRNA cap and an increase in cap-dependent translation. The increase in cap-dependent translation likely results from HPV16 E6-induced AKT/mTORC1 activation, as the assembly of the translation initiation complex and cap-dependent translation are rapamycin sensitive. Lastly, coexpression of the HPV16 E6 and E7 oncoproteins does not affect HPV16 E6-induced activation of mTORC1 and cap-dependent translation. HPV16 E6-mediated activation of mTORC1 signaling and cap-dependent translation may be a mechanism to promote viral replication under conditions of limited nutrient supply in differentiated, HPV oncoprotein-expressing proliferating cells.
Role of Herpes Simplex Virus ICP27 in the Degradation of mRNA by Virion Host Shutoff RNase
Authors: Taddeo Brunella , Zhang Weiran , Roizman Bernard
Published: July 2010

The virion host shutoff (VHS) RNase tegument protein released into cells by infecting virus has two effects. Preexisting stable mRNAs (e.g., GAPDH [glyceraldehyde-3-phosphate dehydrogenase]) are rapidly degraded. Stress response RNAs containing AU-rich elements (AREs) in the 3′ untranslated region (3′UTR) are deadenylated and cleaved, but the cleavage products persist for hours, in contrast to the short half-lives of ARE-containing mRNAs in uninfected cells. At late times, the VHS RNase is neutralized by the viral structural proteins VP16 and VP22. A recent study (J. A. Corcoran, W. L. Hsu, and J. R. Smiley, J. Virol. 80:9720-9729, 2006) reported that, at relatively late times after infection, ARE RNAs are rapidly degraded in cells infected with ΔICP27 mutant virus and concluded that ICP27 “stabilizes” ARE mRNAs. We report the following. (i) The rates of degradation of ARE mRNA at early times (3 h) after infection with the wild type or the ΔICP27 mutant virus are virtually identical, and hence ICP27 plays no role in this process. (ii) In noncomplementing cells, VHS RNase or VP22 is not synthesized. Therefore, the only VHS that is active is brought into cells by the ΔICP27 mutant. (ii) The VHS RNase brought into the cells by the ΔICP27 virus is reduced in potency relative to that of wild-type virus. Hence the rapid degradation of ARE mRNAs noted in ΔICP27 mutant-infected cells at late times is similar to that taking place in mock-infected or in ΔVHS RNase mutant-virus-infected cells and does not by itself support the hypothesis that ICP27 stabilizes ARE mRNAs. (iii) Concurrently, we present the first evidence that VHS RNase interacts with ICP27 most likely when bound to cap- and poly(A)-binding proteins, respectively.
Chronic kidney disease presenting acutely: presentation, clinical features and outcome of patients with irreversible chronic kidney disease who require dialysis immediately
Authors: Wolfe Maytal , Almond Alison , Robertson Sue , Donaldson Ken , Isles Chris
Published: July 2010

Background

Patients with irreversible chronic kidney disease who require dialysis immediately are a subset of ultra late referrals for whom the term chronic kidney disease presenting acutely might usefully be applied. Although well known to nephrologists and recognised as a specific group with considerable problems, little has been written about them.

Objective

To describe the presentation, clinical features and outcome of irreversible chronic kidney disease presenting acutely, with particular reference to nausea and vomiting as presenting symptoms.

Method and results

Review of 202 consecutive patients with irreversible chronic kidney disease who had dialysis between 1996 and 2006 showed that 15 (7%) had required dialysis immediately or within 7 days of presentation. Analysis of 14 available case records showed eight avoidable late referrals: previous evidence of renal failure in six, and two patients with diabetes who had not had their renal function checked. Gastrointestinal symptoms were common and led to further delays in diagnosis, with three patients having endoscopy requested before their bloods were checked. Physical and psychological morbidity associated with this form of presentation was high.

Conclusions

Chronic kidney disease presenting acutely is not uncommon, often avoidable and associated with adverse outcomes. The identification, follow-up and appropriate referral of patients with raised serum creatinine is likely to reduce its incidence. Nausea and vomiting may occur sufficiently frequently in advanced renal failure to justify measuring renal function before proceeding to endoscopy when patients present with gastrointestinal symptoms.
Time trends of female breast cancer mortality in Greece during 1980–2005: a population based study
Authors: Pavlidou E , Zafrakas M , Papadakis N , Agorastos T , Benos A
Published: July 2010

Background

Changes in female breast cancer mortality trends have been observed in recent years in western countries. The aim of the present study was to analyse breast cancer mortality in Greece, between 1980 and 2005.

Methods

Time trends of breast cancer mortality were calculated per 100 000 women in the whole female population of Greece, in different age groups, and in different areas of the country. Mortality data and population age distribution were provided by the National Statistical Service of Greece.

Results

Overall, female breast cancer mortality in Greece had an increasing trend during 1980–2005. Subgroup analysis according to age showed that this increase was confined to women older than 70 years. In contrast, a mild decrease was noted after the mid-1990s in women 40–69 years old. There were no notable regional differences in breast cancer mortality.

Conclusions

The increasing trend of breast cancer mortality in women aged 70 years and older could be attributed to limited use of secondary prevention methods and rare administration of systemic cytotoxic chemotherapy in these women. In contrast, implementation of these strategies could explain the recent reduction of breast cancer mortality in younger age groups.
Republished paper: Determinants of child health and development: the contribution of ALSPAC—a personal view of the birth cohort study
Authors: Golding Jean
Published: July 2010

Britain has a unique experience of national longitudinal birth cohorts, but the Avon Longitudinal Study of Parents and Children differed in two major respects—it was based in one area rather than being a national sample, and it started in pregnancy rather than at birth or later in the first year. This paper outlines a personal selection of 10 topics, highlighting results from some of the 400+ papers that have already been published from this study. It indicates in particular how many childcare and domestic fashions were neither of benefit to the children (or their parents), the importance of pregnancy in regard to childhood conditions and the likely dangers of some common chemicals, whether in medications or domestic products.
Herbivore Diet Affects Fecal Pellet Settling
Authors: Bienfang P. K.
Published: July 2010

The sinking rates of fecal pellets produced by herbivorous zooplankton grazing upon phytoplankton stocks composed primarily of diatoms and flagellates were studied and found to be significantly (P < 0.01) different. Under diatom diet, fecal pellets of Calanus sp. showed ranges of volume and sinking rate of 0.38–2.51∙106 μm3 and 70–171 m∙d−1, respectively; under flagellate-based diet the pellet volumes and sinking rates ranged from 0.42 to 3.52∙106 μm3 and 51 to 152 m∙d−1, respectively. Sinking rates for the two sets of fecal pellets were related to compositional density, and significantly (P < 0.01) correlated with the excess density (Δρ = ρp − ρsw) between the particle and the fluid. No significant (P < 0.05) correlation was found between the sinking rates and volumes of fecal pellets examined in these two sets. Calculated pellet densities (ρp) under diatom and flagellate-based nutrition averaged 1.174 and 1.114 g∙cm−3, and conferred average sinking rates of 123.3 and 87.9 m∙d−1, respectively. A mathematical treatment of the functional parameters relevant to the vertical flux of excretory materials is presented, and by application of steady-state turnover theory, provides a framework to estimate the downward transfer rate per unit area of any given pellet constituent considered.Key words: fecal pellets, herbivorous zooplankton, Calanus, nutrition, sinking rate, model
DERIVATIONS OF THE TRIGONOMETRIC BCn SUTHERLAND MODEL BY QUANTUM HAMILTONIAN REDUCTION
Authors: FEHÉR L. , PUSZTAI B. G.
Published: July 2010

The BCn Sutherland Hamiltonian with coupling constants parametrized by three arbitrary integers is derived by reductions of the Laplace operator of the group U(N). The reductions are obtained by applying the Laplace operator on spaces of certain vector valued functions equivariant under suitable symmetric subgroups of U(N) × U(N). Three different reduction schemes are considered, the simplest one being the compact real form of the reduction of the Laplacian of GL(2n, ℂ) to the complex BCn Sutherland Hamiltonian previously studied by Oblomkov.
THE EINSTEIN–PODOLSKY–ROSEN PROPOSITION ON QUANTUM THEORY AND ITS IMPLICATIONS FOR INTUITIVE CLASSICAL LOGIC
Authors: ESKANDARIAN ALI
Published: July 2010

Einstein, Podolsky and Rosen raised foundational questions about the completeness of quantum mechanics, if certain intuitive logical statements regarding the nature of reality were assumed to be true. These questions are ultimately of significance to the information content of the theory, which is currently the focus of intense research. In this presentation, selected investigations that have made progress in addressing the EPR concerns and that shed light on the nature of quantum states are surveyed. The implications for intuitive classical logic are speculated in the concluding remarks.
GRID DIAGRAMS OF LORENZ LINKS
Authors: RAZUMOVSKY ROMAN
Published: July 2010

In paper [1] Birman and Kofman prove the coincidence of the class of Lorenz links and the class of twisted links. The proof in that work is algebraic. We will identify this class in terms of grid diagrams and provide a transparent geometric argument for Birman–Kofman's result.
ARONSZAJN TREES AND FAILURE OF THE SINGULAR CARDINAL HYPOTHESIS
Authors: NEEMAN ITAY
Published: July 2010

The tree property at κ+states that there are no Aronszajn trees on κ+, or, equivalently, that every κ+tree has a cofinal branch. For singular strong limit cardinals κ, there is tension between the tree property at κ+and failure of the singular cardinal hypothesis at κ; the former is typically the result of the presence of strongly compact cardinals in the background, and the latter is impossible above strongly compacts. In this paper, we reconcile the two. We prove from large cardinals that the tree property at κ+is consistent with failure of the singular cardinal hypothesis at κ.
Secure and robust virtual coordinate system in wireless sensor networks
Authors: Dong Jing , Ackermann Kurt E. , Bavar Brett , Nita-Rotaru Cristina
Published: July 2010

Virtual Coordinate System (VCS)-based routing provides a practical, efficient, and scalable means for point-to-point routing in wireless sensor networks. Several VCS-based routing protocols have been proposed in the last few years, all assuming that nodes behave correctly. However, many applications require deploying sensor networks in adversarial environments, making VCS-based routing protocols vulnerable to numerous attacks.

In this article, we study the security of VCS-based routing protocols, with a focus on the unique component of VCS-based routing protocols, the virtual coordinate system. We first identify the security requirements of a correctly functioning VCS-based routing protocol and a set of novel attacks that can result in the violation of each of the identified requirements. The attacks target the underlying virtual coordinate system and can be mounted with low resources. However, they are epidemic in nature and are highly destructive to system performance. We then propose lightweight defense mechanisms designed specifically for resource-constrained sensor networks against each of the identified attacks. The proposed techniques require only local information on sensor nodes and take into account the unreliable nature of wireless links and network churn. Finally, we evaluate experimentally the impact of the attacks and the effectiveness of our defense mechanisms using a well-known VCS-based routing protocol, BVR. Our experiments show that the proposed techniques successfully mitigate all the identified attacks under a realistic link model and even at a high level of network churn.
Collaborative location certification for sensor networks
Authors: Gao Jie , Sion Radu , Lederer Sol
Published: July 2010

Location information is of essential importance in sensor networks deployed for generating location-specific event reports. When such networks operate in hostile environments, it becomes imperative to guarantee the correctness of event location claims. In this article we address the problem of assessing location claims of untrusted (potentially compromised) nodes. The mechanisms introduced here prevent a compromised node from generating illicit event reports for locations other than its own. This is important because by compromising “easy target” sensors (say, sensors on the perimeter of the field that's easier to access), the adversary should not be able to impact data flows associated with other (“premium target”) regions of the network.

To achieve this goal, in a process we call
location certification
, data routed through the network is “tagged” by participating nodes with “belief” ratings, collaboratively assessing the probability that the claimed source location is indeed correct. The effectiveness of our solution relies on the joint knowledge of participating nodes to assess the truthfulness of claimed locations. By collaboratively generating and propagating a set of “belief” ratings with transmitted data and event reports, the network allows authorized parties (e.g., final data sinks) to evaluate a metric of trust for the claimed location of such reports. Belief ratings are derived from a data model of observed past routing activity. The solution is shown to feature a strong ability to detect false location claims and compromised nodes. For example, incorrect claims as small as 2 hops (from the actual location) are detected with over 90% accuracy.

Finally, these new location certification mechanisms can be deployed in tandem with traditional secure localization, yet do not require it, and, in a sense, can serve to minimize the need thereof.
Example-based facial rigging
Authors: Li Hao , Weise Thibaut , Pauly Mark
Published: July 2010

We introduce a method for generating facial blendshape rigs from a set of example poses of a CG character. Our system transfers controller semantics and expression dynamics from a generic template to the target blendshape model, while solving for an optimal reproduction of the training poses. This enables a scalable design process, where the user can iteratively add more training poses to refine the blendshape expression space. However, plausible animations can be obtained even with a single training pose. We show how formulating the optimization in gradient space yields superior results as compared to a direct optimization on blendshape vertices. We provide examples for both hand-crafted characters and 3D scans of a real actor and demonstrate the performance of our system in the context of markerless art-directable facial tracking.
Geodesic patterns
Authors: Pottmann Helmut , Huang Qixing , Deng Bailin , Schiftner Alexander , Kilian Martin , Guibas Leonidas , Wallner Johannes
Published: July 2010

Geodesic curves in surfaces are not only minimizers of distance, but they are also the curves of zero geodesic (sideways) curvature. It turns out that this property makes
patterns of geodesics
the basic geometric entity when dealing with the cladding of a freeform surface with wooden panels which do not bend sideways. Likewise a geodesic is the favored shape of timber support elements in freeform architecture, for reasons of manufacturing and statics. Both problem areas are fundamental in freeform architecture, but so far only experimental solutions have been available. This paper provides a systematic treatment and shows how to design geodesic patterns in different ways: The evolution of geodesic curves is good for local studies and simple patterns; the level set formulation can deal with the global layout of multiple patterns of geodesics; finally geodesic vector fields allow us to interactively model geodesic patterns and perform surface segmentation into panelizable parts.
Physical reproduction of materials with specified subsurface scattering
Authors: Hašan Miloš , Fuchs Martin , Matusik Wojciech , Pfister Hanspeter , Rusinkiewicz Szymon
Published: July 2010

We investigate a complete pipeline for measuring, modeling, and fabricating objects with specified subsurface scattering behaviors. The process starts with measuring the scattering properties of a given set of base materials, determining their radial reflection and transmission profiles. We describe a mathematical model that predicts the profiles of different stackings of base materials, at arbitrary thicknesses. In an inverse process, we can then specify a desired reflection profile and compute a layered composite material that best approximates it. Our algorithm efficiently searches the space of possible combinations of base materials, pruning unsatisfactory states imposed by physical constraints. We validate our process by producing both homogeneous and heterogeneous composites fabricated using a multi-material 3D printer. We demonstrate reproductions that have scattering properties approximating complex materials.
Subspace self-collision culling
Authors: Barbič Jernej , James Doug L.
Published: July 2010

We show how to greatly accelerate self-collision detection (SCD) for reduced deformable models. Given a triangle mesh and a set of deformation modes, our method precomputes
Subspace Self-Collision Culling (SSCC) certificates
which, if satisfied, prove the absence of self-collisions for large parts of the model. At runtime, bounding volume hierarchies augmented with our certificates can aggressively cull overlap tests and reduce hierarchy updates. Our method supports both discrete and continuous SCD, can handle complex geometry, and makes no assumptions about geometric smoothness or normal bounds. It is particularly effective for simulations with modest subspace deformations, where it can often verify the absence of self-collisions in
constant time.
Our certificates enable low amortized costs, in time and across many objects in multi-body dynamics simulations. Finally, SSCC is effective enough to support self-collision tests at audio rates, which we demonstrate by producing the first sound simulations of clattering objects.
Volume contact constraints at arbitrary resolution
Authors: Allard Jérémie , Faure François , Courtecuisse Hadrien , Falipou Florent , Duriez Christian , Kry Paul G.
Published: July 2010

We introduce a new method for simulating frictional contact between volumetric objects using interpenetration volume constraints. When applied to complex geometries, our formulation results in dramatically simpler systems of equations than those of traditional mesh contact models. Contact between highly detailed meshes can be simplified to a single unilateral constraint equation, or accurately processed at arbitrary geometry-independent resolution with simultaneous sticking and sliding across contact patches. We exploit fast GPU methods for computing layered depth images, which provides us with the intersection volumes and gradients necessary to formulate the contact equations as linear complementarity problems. Straightforward and popular numerical methods, such as projected Gauss-Seidel, can be used to solve the system. We demonstrate our method in a number of scenarios and present results involving both rigid and deformable objects at interactive rates.
By-example synthesis of architectural textures
Authors: Lefebvre Sylvain , Hornus Samuel , Lasram Anass
Published: July 2010

Textures are often reused on different surfaces in large virtual environments. This leads to unpleasing stretch and cropping of features when textures contain architectural elements. Existing retargeting methods could adapt each texture to the size of their support surface, but this would imply storing a different image for each and every surface, saturating memory. Our new texture synthesis approach casts synthesis as a shortest path problem in a graph describing the space of images that can be synthesized. Each path in the graph describes how to form a new image by cutting strips of the source image and reassembling them in a different order. Only the paths describing the result need to be stored in memory: synthesized textures are reconstructed at rendering time. The user can control repetition of features, and may specify positional constraints. We demonstrate our approach on a variety of textures, from facades for large city rendering to structured textures commonly used in video games.
Dynamic video narratives
Authors: Correa Carlos D. , Ma Kwan-Liu
Published: July 2010

This paper presents a system for generating dynamic narratives from videos. These narratives are characterized for being compact, coherent and interactive, as inspired by principles of sequential art. Narratives depict the motion of one or several actors over time. Creating compact narratives is challenging as it is desired to combine the video frames in a way that reuses redundant backgrounds and depicts the stages of a motion. In addition, previous approaches focus on the generation of static summaries and can afford expensive image composition techniques. A dynamic narrative, on the other hand, must be played and skimmed in real-time, which imposes certain cost limitations in the video processing. In this paper, we define a novel process to compose foreground and background regions of video frames in a single interactive image using a series of spatio-temporal masks. These masks are created to improve the output of automatic video processing techniques such as image stitching and foreground segmentation. Unlike hand-drawn narratives, often limited to static representations, the proposed system allows users to explore the narrative dynamically and produce different representations of motion. We have built an authoring system that incorporates these methods and demonstrated successful results on a number of video clips. The authoring system can be used to create interactive posters of video clips, browse video in a compact manner or highlight a motion sequence in a movie.
SmartBoxes for interactive urban reconstruction
Authors: Nan Liangliang , Sharf Andrei , Zhang Hao , Cohen-Or Daniel , Chen Baoquan
Published: July 2010

We introduce an interactive tool which enables a user to quickly assemble an architectural model directly over a 3D point cloud acquired from large-scale scanning of an urban scene. The user loosely defines and manipulates simple building blocks, which we call SmartBoxes, over the point samples. These boxes quickly snap to their proper locations to conform to common architectural structures. The key idea is that the building blocks are smart in the sense that their locations and sizes are automatically adjusted on-the-fly to fit well to the point data, while at the same time respecting contextual relations with nearby similar blocks. SmartBoxes are assembled through a discrete optimization to balance between two snapping forces defined respectively by a data-fitting term and a contextual term, which together assist the user in reconstructing the architectural model from a sparse and noisy point cloud. We show that a combination of the user's interactive guidance and high-level knowledge about the semantics of the underlying model, together with the snapping forces, allows the reconstruction of structures which are partially or even completely missing from the input.
Ambient point clouds for view interpolation
Authors: Goesele Michael , Ackermann Jens , Fuhrmann Simon , Haubold Carsten , Klowsky Ronny , Steedly Drew , Szeliski Richard
Published: July 2010

View interpolation and image-based rendering algorithms often produce visual artifacts in regions where the 3D scene geometry is erroneous, uncertain, or incomplete. We introduce ambient point clouds constructed from colored pixels with uncertain depth, which help reduce these artifacts while providing non-photorealistic background coloring and emphasizing reconstructed 3D geometry. Ambient point clouds are created by randomly sampling colored points along the viewing rays associated with uncertain pixels. Our real-time rendering system combines these with more traditional rigid 3D point clouds and colored surface meshes obtained using multiview stereo. Our resulting system can handle larger-range view transitions with fewer visible artifacts than previous approaches.
A coaxial optical scanner for synchronous acquisition of 3D geometry and surface reflectance
Authors: Holroyd Michael , Lawrence Jason , Zickler Todd
Published: July 2010

We present a novel optical setup and processing pipeline for measuring the 3D geometry and spatially-varying surface reflectance of physical objects. Central to our design is a digital camera and a high frequency spatially-modulated light source aligned to share a common focal point and optical axis. Pairs of such devices allow capturing a sequence of images from which precise measurements of geometry
and
reflectance can be recovered. Our approach is enabled by two technical contributions: a new active multiview stereo algorithm and an analysis of light descattering that has important implications for image-based reflectometry. We show that the geometry measured by our scanner is accurate to within 50 microns at a resolution of roughly 200 microns and that the reflectance agrees with reference data to within 5.5%. Additionally, we present an image relighting application and show renderings that agree very well with reference images at light and view positions far from those that were initially measured.
Apparent display resolution enhancement for moving images
Authors: Didyk Piotr , Eisemann Elmar , Ritschel Tobias , Myszkowski Karol , Seidel Hans-Peter
Published: July 2010

Limited spatial resolution of current displays makes the depiction of very fine spatial details difficult. This work proposes a novel method applied to moving images that takes into account the human visual system and leads to an improved perception of such details. To this end, we display images rapidly varying over time along a given trajectory on a high refresh rate display. Due to the retinal integration time the information is fused and yields apparent super-resolution pixels on a conventional-resolution display. We discuss how to find optimal temporal pixel variations based on linear eye-movement and image content and extend our solution to arbitrary trajectories. This step involves an efficient method to predict and successfully treat potentially visible flickering. Finally, we evaluate the resolution enhancement in a perceptual study that shows that significant improvements can be achieved both for computer generated images and photographs.
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p

Centroidal Voronoi Tessellation and its applications
Authors: Lévy Bruno , Liu Yang
Published: July 2010

This paper introduces
L

p

-Centroidal Voronoi Tessellation (
L

p

-CVT), a generalization of CVT that minimizes a higher-order moment of the coordinates on the Voronoi cells. This generalization allows for aligning the axes of the Voronoi cells with a predefined background tensor field (anisotropy).
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p

-CVT is computed by a quasi-Newton optimization framework, based on closed-form derivations of the objective function and its gradient. The derivations are given for both surface meshing (Ω is a triangulated mesh with per-facet anisotropy) and volume meshing (Ω is the interior of a closed triangulated mesh with a 3D anisotropy field). Applications to anisotropic, quad-dominant surface remeshing and to hexdominant volume meshing are presented. Unlike previous work,
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p

-CVT captures sharp features and intersections without requiring any pre-tagging.
A synthetic-vision based steering approach for crowd simulation
Authors: Ondřej Jan , Pettré Julien , Olivier Anne-Hélène , Donikian Stéphane
Published: July 2010

In the everyday exercise of controlling their locomotion, humans rely on their optic flow of the perceived environment to achieve collision-free navigation. In crowds, in spite of the complexity of the environment made of numerous obstacles, humans demonstrate remarkable capacities in avoiding collisions. Cognitive science work on human locomotion states that relatively succinct information is extracted from the optic flow to achieve safe locomotion. In this paper, we explore a novel vision-based approach of collision avoidance between walkers that fits the requirements of interactive crowd simulation. By simulating humans based on cognitive science results, we detect future collisions as well as the level of danger from visual stimuli. The motor-response is twofold: a reorientation strategy prevents future collision, whereas a deceleration strategy prevents imminent collisions. Several examples of our simulation results show that the emergence of self-organized patterns of walkers is reinforced using our approach. The emergent phenomena are visually appealing. More importantly, they improve the overall efficiency of the walkers' traffic and avoid improbable locking situations.
Multi-scale image harmonization
Authors: Sunkavalli Kalyan , Johnson Micah K. , Matusik Wojciech , Pfister Hanspeter
Published: July 2010

Traditional image compositing techniques, such as alpha matting and gradient domain compositing, are used to create composites that have plausible boundaries. But when applied to images taken from different sources or shot under different conditions, these techniques can produce unrealistic results. In this work, we present a framework that explicitly matches the visual appearance of images through a process we call
image harmonization
, before blending them. At the heart of this framework is a multi-scale technique that allows us to transfer the appearance of one image to another. We show that by carefully manipulating the scales of a pyramid decomposition of an image, we can match contrast, texture, noise, and blur, while avoiding image artifacts. The output composite can then be reconstructed from the modified pyramid coefficients while enforcing both alpha-based and seamless boundary constraints. We show how the proposed framework can be used to produce realistic composites with minimal user interaction in a number of different scenarios.
Feature-based locomotion controllers
Authors: de Lasa Martin , Mordatch Igor , Hertzmann Aaron
Published: July 2010

This paper introduces an approach to control of physics-based characters based on high-level features of movement, such as center-of-mass, angular momentum, and end-effectors. Objective terms are used to control each feature, and are combined by a prioritization algorithm. We show how locomotion can be expressed in terms of a small number of features that control balance and end-effectors. This approach is used to build controllers for human balancing, standing jump, and walking. These controllers provide numerous benefits: human-like qualities such as arm-swing, heel-off, and hip-shoulder counter-rotation emerge automatically during walking; controllers are robust to changes in body parameters; control parameters and goals may be modified at run-time; control parameters apply to intuitive properties such as center-of-mass height; and controllers may be mapped onto entirely new bipeds with different topology and mass distribution, without modifications to the controller itself. No motion capture or off-line optimization process is used.
A tight Karp-Lipton collapse result in bounded arithmetic
Authors: Beyersdorff Olaf , Müller Sebastian
Published: July 2010

Cook and Krajíček have recently obtained the following Karp-Lipton collapse result in bounded arithmetic: if the theory
PV
proves NP⊆ P/
poly
, then the polynomial hierarchy collapses to the Boolean hierarchy, and this collapse is provable in
PV
. Here we show the converse implication, thus answering an open question posed by Cook and Krajíček. We obtain this result by formalizing in
PV
a hard/easy argument of Buhrman et al. [2003].

In addition, we continue the investigation of propositional proof systems using advice, initiated by Cook and Krajíček. In particular, we obtain several optimality results for proof systems using advice. We further show that these optimal systems are equivalent to natural extensions of Frege systems.