bluuebunny/crossref_metadata_2025 huggingface dataset:
Cohomology bounds for sheaves of dimension one
Authors: Choi Jinwon , Chung Kiryong
Published: October 2014

We find sharp bounds on h0(F) for one-dimensional semistable sheaves F on a projective variety X. When X is the projective plane ℙ2, we study the stratification of the moduli space by the spectrum of sheaves. We show that the deepest stratum is isomorphic to a closed subset of a relative Hilbert scheme. This provides an example of a family of semistable sheaves having the biggest dimensional global section space.
On the anomalous peak in the forward bias capacitance and conduction mechanism in the Au/n-4H SiC (MS) Schottky diodes (SDs) in the temperature range of 140–400 K
Authors: Kaya Ahmet
Published: October 2014

The temperature and voltage dependence profile of the surface states (Nss), series resistance (Rs) and electrical conductivity (σ ac ) have been investigated in temperature and voltage ranges of 140–400 K and (-5 V )-(6 V ), respectively. The value of barrier height (BH) decreases with increasing temperature as ΦB(T) = (1.02 - 4×10-4⋅ T ) eV. These values of negative temperature coefficient (-4×10-4 eV ⋅ K -1) is in good agreement with the α of band gap of SiC (-3.1×10-4 eV ⋅ K -1). Capacitance-voltage (C–V) plots for all temperatures show an anomalous peak in the accumulation region because of the effect of series resistance (Rs) and Nss. The effect of Rs and Nss on the C and conductance (G) are found noticeable high especially at low temperatures. The decrease in C values also corresponds to an increase in G/ω values in the accumulation region. In addition, Ln (σ ac ) versus q/kT plots have two straight lines with different slopes which are corresponding to below and above room temperatures for various forward biases which are an evident two valid possible conduction mechanisms. The values of activation energy (Ea) were obtained from the slope of these plots and they changed from 6.3 meV to 4.7 meV below room temperatures and 42.5 meV to 34.4 meV for above room temperatures, respectively.
Spin-polarized electron transmission resonance through a driven quantum well with spin-orbit coupling
Authors: Ding Xiu-Huan , Zhang Cun-Xi , Wang Rui
Published: October 2014

In this paper, we study the spin-dependent electron transmission through a quantum well in semiconductor heterostructures with dipole-type oscillation field and homogeneous oscillation field. The numerical evaluations show that Dresselhaus spin-orbit coupling eliminates the spin degeneracy and leads to the splitting of asymmetric Fano-type resonance peaks in the transmissivity. The width of the splitting peaks is found to be highly sensitive to the direction of incident electron. The dipole modulation and the homogeneous modulation is approximately equivalent under certain conditions. The location and the line shape of the Fano-type resonance can be controlled by adjusting the energy and the direction of the incident electron, the oscillation frequency, and the amplitude of the external field. These interesting features may be used to devise tunable spin filters and realize pure spin transmission currents by the more practical dipole-type oscillation in the experimental setup.
Study the structure and performance of thermal/plasma modified Au nanoparticle-doped TiO2 photocatalyst
Authors: Mahmood Asif , Ramay Shahid M. , Al-Zaghayer Yousef S. , Atiq Shahid , Ahmad Iftikhar , Shar Muhammad Ali , Khan Salah Din
Published: October 2014

This study describes the influence of thermal/plasma treatments on the structure and photocatalytic performance of the Au -doped TiO 2 catalyst. Au (gold) nanoparticles were attached on TiO 2 (Titania) nanoparticle surfaces by conventional deposition precipitation technique and the resulting catalysts were subsequently modified with thermal (at 450°C under vacuum) and plasma (at an ambient temperature under Argon atmosphere for 20 min) treatments. Structural characterization of the modified catalysts was performed by diverse analytical techniques and the photocatalytic activity was evaluated by assessing the degradation of the methylene blue (MB) in water under UV (ultra-violet) irradiations. Results showed that the thermal/plasma treatment significantly influenced the structural features of Au -doped TiO 2 catalyst by altering the morphology, increasing the Au nanoparticles population, improving the Au / TiO 2 catalytic activity, changing the textural properties and reducing the band gap energies thus tuned Au -doped TiO 2 catalyst to higher efficiency. Thermal/plasma treated Au -doped TiO 2 was found to exhibit higher photocatalytic activity than the as-synthesized (pristine sample). This improvement in photocatalytic activity might be due to the cathodic influence of gold in suppressing the electron–hole recombination during the reaction.
Equation of state and thermal expansion of metals with FCC structure: Application to Cu, Al and Ni
Authors: Tam Pham Dinh , Hoc Nguyen Quang , Tinh Bui Duc , Hien Nguyen Duc
Published: October 2014

The equation of state, the expressions of lattice parameter and thermal expansion coefficient in general form are obtained by the statistical moment method. Applying to Cu , Al and Ni metals, we determine these properties in simple analytic form for each metal. Numerical results for the thermal expansion coefficient of these metals in different temperatures and pressures are in good agreement with experiments.
Appearance of Boulware–Deser ghost in bigravity with doubly coupled matter
Authors: Yamashita Yasuho , De Felice Antonio , Tanaka Takahiro
Published: October 2014

In this paper, we discuss the ghost freeness in the case when we add matter coupled to two metrics to the ghost-free bigravity. In this paper we show that the Boulware–Deser ghost generally revives in the presence of doubly coupled matter and that ghost freeness strongly restricts the model of kinetically doubly coupled matter. This result may anticipate difficulties in the attempt to derive the ghost-free bigravity as a low-energy effective theory, starting with a model applicable at high energies.
Life's Bottleneck: Sustaining the World's Phosphorus for a Food Secure Future
Authors: Cordell Dana , White Stuart
Published: October 2014

Phosphorus security is emerging as one of the twenty-first century's greatest global sustainability challenges. Phosphorus has no substitute in food production, and the use of phosphate fertilizers in the past 50 years has boosted crop yields and helped feed billions of people. However, these advantages have come at a serious cost. Mobilizing phosphate rock into the environment at rates vastly faster than the natural cycle has not only polluted many of the world's freshwater bodies and oceans, but has also created a human dependence on a single nonrenewable resource. The 2008 phosphate price spike attracted unprecedented attention to this global situation. This review provides an updated and integrated synthesis of the biophysical, social, geopolitical, and institutional challenges and opportunities for food security. Remaining phosphorus resources are becoming increasingly scarce, expensive, and inequitably distributed. All farmers require fertilizers, yet a sixth of the world's farmers and their families are too poor to access fertilizer markets. Inefficient use of this fossil resource from mine to field to fork calls for substantial reduction in demand through efficiency and recycling. Phosphorus governance at global, regional, and local scales is required to stimulate and support context-specific sustainable strategies to ensure all the world's farmers have sufficient access to phosphorus to feed the world and ensure ecosystem integrity and farmer livelihoods.
Water Security and Society: Risks, Metrics, and Pathways
Authors: Garrick Dustin , Hall Jim W.
Published: October 2014

Water security is a major challenge for science and society. We review the rapidly growing literature on water security from the perspective of risk science and management. Competing definitions and indicators of water security reflect unsettled conceptual and methodological issues. However, risk concepts have become prevalent in defining water security; measuring it quantitatively; tracking indicators of hazards, exposure, and vulnerability; and informing management options to reduce water-related risks. We examine water security indicators and indices to identify thresholds for water-related risks across multiple dimensions of water security and examine how these vary across different scales and socioeconomic contexts. Water security indicators reveal a disparity in hazards and vulnerability across geographic and political-economic conditions. Recognition of water security as a major societal challenge has been closely followed by a strong commitment to academic, government, development, and policy responses. Pathways to water security capture the sequence of investments in institutions and infrastructure to reduce water-related risks and manage trade-offs. Two well-studied water management case studies illustrate the pathways to water security and the need for more systematic comparative assessment.
Gender and Sustainability
Authors: Meinzen-Dick Ruth , Kovarik Chiara , Quisumbing Agnes R.
Published: October 2014

Sustainability and gender have been prominent on the development agenda since the 1980s, but there has been little systematic study of the links between the two. This review draws on ecofeminist theory, feminist political ecology, intrahousehold literature, and natural resource management case studies and reviews to examine how gender shapes the motives, means, and opportunities for men and women to contribute to sustainability. Particular attention is given to evidence on closeness to nature, focus on conservation, rights to resources, opportunities to exploit resources, and constraints to adoption of sustainable practices. Despite early claims that women are naturally more conserving of resources, the empirical literature, in particular, gives a more mixed and nuanced picture. Conservation is influenced not only by gender but also by a host of tangible and intangible factors, including local ecology, context, and culture, that affect incentives and the ability to adopt sustainable extraction and provision practices.
TFF2 deficiency exacerbates weight loss and alters immune cell and cytokine profiles in DSS colitis, and this cannot be rescued by wild-type bone marrow
Authors: Judd Louise M. , Chalinor Heather V. , Walduck Anna , Pavlic Daniel I. , Däbritz Jan , Dubeykovskaya Zinaida , Wang Timothy C. , Menheniott Trevelyan R. , Giraud Andrew S.
Published: October 2014

The trefoil factor TFF2 is a member of a tripartite family of small proteins that is produced by the stomach and the colon. Recombinant TFF2, when applied intrarectally in a rodent model of hapten colitis, hastens mucosal healing and reduces inflammatory indexes. Additionally, TFF2 is expressed in immune organs, supporting a potential immunomodulatory and reparative role in the bowel. In this study we confirm that TFF2 is expressed in the colon and is specifically enriched in epithelial cells relative to colonic leukocytes. TFF2-deficient, but not TFF1-deficient, mice exhibit a more severe response to acute or chronic dextran sulfate (DSS)-induced colitis that correlates with a 50% loss of expression of TFF3, the principal colonic trefoil. In addition, the response to acute colitis is associated with altered expression of IL-6 and IL-33, but not other inflammatory cytokines. While TFF2 can reduce macrophage responsiveness and block inflammatory cell recruitment to the colon, the major role in limiting the susceptibility to acute colitis appears to be maintenance of barrier function. Bone marrow transfer experiments demonstrate that leukocyte expression of TFF2 is not sufficient for prevention of colitis induction but, rather, that the gastrointestinal epithelium is the primary source of TFF2. Together, these findings illustrate that epithelial TFF2 is an important endogenous regulator of gut mucosal homeostasis that can modulate immune and epithelial compartments. Because of its extreme stability, even in the corrosive gut lumen, TFF2 is an attractive candidate as an oral therapeutic scaffold for future drug development in the treatment of inflammatory bowel disease.
Decreased plasma soluble erythropoietin receptor in high-altitude excessive erythrocytosis and Chronic Mountain Sickness
Authors: Villafuerte Francisco C. , Macarlupú José Luis , Anza-Ramírez Cecilia , Corrales-Melgar Daniela , Vizcardo-Galindo Gustavo , Corante Noemí , León-Velarde Fabiola
Published: October 2014

Excessive erythrocytosis (EE) is the hallmark of chronic mountain sickness (CMS), a prevalent syndrome in high-altitude Andean populations. Although hypoxemia represents its underlying stimulus, why some individuals develop EE despite having altitude-normal blood erythropoietin (Epo) concentration is still unclear. A soluble form of the Epo receptor (sEpoR) has been identified in human blood and competes directly for Epo with its membrane counterpart (mEpoR). Thus, reduced levels of circulating sEpoR could lead to higher Epo availability and ultimately to EE. We characterized the relationship between Epo and sEpoR, with hematocrit and hemoglobin concentration in healthy highlanders and CMS patients at 4,340 m in Cerro de Pasco, Peru. Our results show that EE patients show decreased plasma sEpoR levels and can be subdivided into two subgroups of normal and high plasma Epo concentration for the altitude of residence, with hemoglobin concentration rising exponentially with an increasing Epo-to-sEpoR ratio (Epo/sEpoR). Also, we showed that the latter varies as an inverse exponential function of arterial pulse O2saturation. Our findings suggests that EE is strongly associated with higher Epo/sEpoR values, leading to elevated plasma Epo availability to bind mEpoR, and thereby a stronger stimulus for augmented erythropoiesis. Differences in the altitude normal and high Epo CMS patients with a progressively higher Epo/sEpoR supports the hypothesis of the existence of two genetically different subgroups suffering from EE and possibly different degrees of adaptation to chronic high-altitude hypoxia.
New Strategies in Acute Myelogenous Leukemia: Leukemogenesis and Personalized Medicine
Authors: Gojo Ivana , Karp Judith E.
Published: October 2014

Recent advances in molecular technology have unraveled the complexity of leukemogenesis and provided the opportunity to design more personalized and pathophysiology-targeted therapeutic strategies. Despite the use of intensive chemotherapy, relapse remains the most common cause for therapeutic failure in acute myelogenous leukemia (AML). The interactions between leukemia stem cells (LSC) and marrow microenvironment appear to be critical in promoting therapeutic resistance through progressive acquisition of genetic and epigenetic changes within leukemia cells and immune evasion, resulting in leukemia cell survival. With advances in genomic-sequencing efforts, epigenetic and phenotypic characterization, personalized therapeutic strategies aimed at critical leukemia survival mechanisms may be feasible in the near future. Here, we review select novel approaches to therapy of AML such as targeting LSC, altering leukemia/marrow microenvironment interactions, inhibiting DNA repair or cell-cycle checkpoints, and augmenting immune-based antileukemia activity. Clin Cancer Res; 20(24); 6233–41. ©2014 AACR.
Prognostic Impact of Human Leukocyte Antigen Class I Expression and Association of Platinum Resistance with Immunologic Profiles in Epithelial Ovarian Cancer
Authors: Mariya Tasuku , Hirohashi Yoshihiko , Torigoe Toshihiko , Asano Takuya , Kuroda Takafumi , Yasuda Kazuyo , Mizuuchi Masahito , Sonoda Tomoko , Saito Tsuyoshi , Sato Noriyuki
Published: October 2014

Epithelial ovarian cancer (EOC) is one of the most deadly carcinomas in females. Immune systems can recognize EOCs; however, a defect of human leukocyte antigen (HLA) class I expression is known to be a major mechanism for escape from immune systems, resulting in poor prognosis. The purpose of this study is to identify novel correlations between immunologic responses and other clinical factors. We investigated the expression of immunologic components in 122 cases of EOCs for which surgical operations were performed between 2001 and 2011. We immunohistochemically stained EOC specimens using an anti-pan HLA class I monoclonal antibody (EMR8-5) and anti-CD3, -CD4, and -CD8 antibodies, and we analyzed correlations between immunologic parameters and clinical factors. In multivariate analysis that used the Cox proportional hazards model, independent prognostic factors for overall survival in advanced EOCs included low expression level of HLA class I [risk ratio (RR), 1.97; 95% confidence interval (CI), 1.01–3.83; P = 0.046] and loss of intraepithelial cytotoxic T lymphocyte (CTL) infiltration (RR, 2.11; 95% CI, 1.06–4.20; P = 0.033). Interestingly, almost all platinum-resistant cases showed a significantly low rate of intraepithelial CTL infiltration in the χ2 test (positive vs. negative: 9.0% vs. 97.7%; P < 0.001). Results from a logistic regression model revealed that low CTL infiltration rate was an independent factor of platinum resistance in multivariate analysis (OR, 3.77; 95% CI, 1.08–13.12; P = 0.037). Platinum-resistant EOCs show poor immunologic responses. The immune escape system of EOCs may be one of the mechanisms of platinum resistance. Cancer Immunol Res; 2(12); 1220–9. ©2014 AACR.
5-Lipoxygenase Pathway in Experimental Abdominal Aortic Aneurysms
Authors: Bhamidipati Castigliano M. , Whatling Carl A. , Mehta Gaurav S. , Meher Akshaya K. , Hajzus Vanessa A. , Su Gang , Salmon Morgan , Upchurch Gilbert R. , Owens Gary K. , Ailawadi Gorav
Published: October 2014

Objective—

The impact of leukotriene production by the 5-lipoxygenase (5-LO) pathway in the pathophysiology of abdominal aortic aneurysms (AAAs) has been debated. Moreover, a clear mechanism through which 5-LO influences AAA remains unclear.

Approach and Results—

Aneurysm formation was attenuated in 5-LO
–/–
mice, and in lethally irradiated wild-type mice reconstituted with 5-LO
–/–
bone marrow in an elastase perfusion model. Pharmacological inhibition of 5-LO–attenuated aneurysm formation in both aortic elastase perfused wild-type and angiotensin II–treated LDLr
–/–
(low-density lipoprotein receptor) mice, with resultant preservation of elastin and fewer 5-LO and MMP9 (matrix metalloproteinase)-producing cells. Separately, analysis of wild-type mice 7 days after elastase perfusion showed that 5-LO inhibition was associated with reduced polymorphonuclear leukocyte infiltration to the aortic wall. Importantly, 5-LO inhibition initiated 3 days after elastase perfusion in wild-type mice arrested progression of small AAA. Human AAA and control aorta corroborated these elastin and 5-LO expression patterns.

Conclusions—

Inhibition of 5-LO by pharmacological or genetic approaches attenuates aneurysm formation and prevents fragmentation of the medial layer in 2 unique AAA models. Administration of 5-LO inhibitor in small AAA slows progression of AAA. Targeted interruption of the 5-LO pathway is a potential treatment strategy in AAA.
DNA Methylation of a GC Repressor Element in the Smooth Muscle Myosin Heavy Chain Promoter Facilitates Binding of the Notch-Associated Transcription Factor, RBPJ/CSL1
Authors: Rozenberg Julian M. , Tesfu Daniel B. , Musunuri Srilaxmi , Taylor Joan M. , Mack Christopher P.
Published: October 2014

Objective—

The goal of the present study was to identify novel mechanisms that regulate smooth muscle cell (SMC) differentiation marker gene expression.

Approach and Results—

We demonstrate that the CArG-containing regions of many SMC-specific promoters are imbedded within CpG islands. A previously identified GC repressor element in the SM myosin heavy chain (MHC) promoter was highly methylated in cultured aortic SMC but not in the aorta, and this difference was inversely correlated with SM MHC expression. Using an affinity chromatography/mass spectroscopy–based approach, we identified the multifunctional Notch transcription factor, recombination signal binding protein for immunoglobulin κ J region (RBPJ), as a methylated GC repressor–binding protein. RBPJ protein levels and binding to the endogenous SM MHC GC repressor were enhanced by platelet-derived growth factor-BB treatment. A methylation mimetic mutation to the GC repressor that facilitated RBPJ binding inhibited SM MHC promoter activity as did overexpression of RBPJ. Consistent with this, knockdown of RBPJ in phenotypically modulated human aortic SMC enhanced endogenous SMC marker gene expression, an effect likely mediated by increased recruitment of serum response factor and Pol II to the SMC-specific promoters. In contrast, the depletion of RBPJ in differentiated transforming growth factor-β–treated SMC inhibited SMC-specific gene activation, supporting the idea that the effects of RBPJ/Notch signaling are context dependent.

Conclusions—

Our results indicate that methylation-dependent binding of RBPJ to a GC repressor element can negatively regulate SM MHC promoter activity and that RBPJ can inhibit SMC marker gene expression in phenotypically modulated SMC. These results will have important implications on the regulation of SMC phenotype and on Notch-dependent transcription.
Does Aneurysmal Wall Enhancement on Vessel Wall MRI Help to Distinguish Stable From Unstable Intracranial Aneurysms?
Authors: Edjlali Myriam , Gentric Jean-Christophe , Régent-Rodriguez Christine , Trystram Denis , Hassen Wajih Ben , Lion Stéphanie , Nataf François , Raymond Jean , Wieben Oliver , Turski Patrick , Meder Jean-Francois , Oppenheim Catherine , Naggara Olivier
Published: October 2014

Background and Purpose—

Arterial wall enhancement on vessel wall MRI was described in intracranial inflammatory arterial disease. We hypothesized that circumferential aneurysmal wall enhancement (CAWE) could be an indirect marker of aneurysmal wall inflammation and, therefore, would be more frequent in unstable (ruptured, symptomatic, or undergoing morphological modification) than in stable (incidental and nonevolving) intracranial aneurysms.

Methods—

We prospectively performed vessel wall MRI in patients with stable or unstable intracranial aneurysms. Two readers independently had to determine whether a CAWE was present.

Results—

We included 87 patients harboring 108 aneurysms. Interreader and intrareader agreement for CAWE was excellent (κ=0.85; 95% confidence interval, 0.75–0.95 and κ=0.90; 95% confidence interval, 0.83–0.98, respectively). A CAWE was significantly more frequently seen in unstable than in stable aneurysms (27/31, 87% versus 22/77, 28.5%, respectively;
P
<0.0001). Multivariate logistic regression, including CAWE, size, location, multiplicity of aneurysms, and daily aspirin intake, revealed that CAWE was the only independent factor associated with unstable status (odds ratio, 9.20; 95% confidence interval, 2.92–29.0;
P
=0.0002).

Conclusions—

CAWE was more frequently observed in unstable intracranial aneurysms and may be used as a surrogate of inflammatory activity in the aneurysmal wall.
Multisensory Feedback Can Enhance Embodiment Within an Enriched Virtual Walking Scenario
Authors: Leonardis Daniele , Frisoli Antonio , Barsotti Michele , Carrozzino Marcello , Bergamasco Massimo
Published: October 2014

This study investigates how the sense of embodiment in virtual environments can be enhanced by multisensory feedback related to body movements. In particular, we analyze the effect of combined vestibular and proprioceptive afferent signals on the perceived embodiment within an immersive walking scenario. These feedback signals were applied by means of a motion platform and by tendon vibration of lower limbs, evoking illusory leg movements. Vestibular and proprioceptive feedback were provided congruently with a rich virtual scenario reconstructing a real city, rendered on a head-mounted display (HMD). The sense of embodiment was evaluated through both self-reported questionnaires and physiological measurements in two experimental conditions: with all active sensory feedback (highly embodied condition), and with visual feedback only. Participants' self-reports show that the addition of both vestibular and proprioceptive feedback increases the sense of embodiment and the individual's feeling of presence associated with the walking experience. Furthermore, the embodiment condition significantly increased the measured galvanic skin response and respiration rate. The obtained results suggest that vestibular and proprioceptive feedback can improve the participant's sense of embodiment in the virtual experience.
fMRI-Based Robotic Embodiment: Controlling a Humanoid Robot by Thought Using Real-Time fMRI
Authors: Cohen Ori , Druon Sébastien , Lengagne Sébastien , Mendelsohn Avi , Malach Rafael , Kheddar Abderrahmane , Friedman Doron
Published: October 2014

We present a robotic embodiment experiment based on real-time functional magnetic resonance imaging (rt-fMRI). In this study, fMRI is used as an input device to identify a subject's intentions and convert them into actions performed by a humanoid robot. The process, based on motor imagery, has allowed four subjects located in Israel to control a HOAP3 humanoid robot in France, in a relatively natural manner, experiencing the whole experiment through the eyes of the robot. Motor imagery or movement of the left hand, the right hand, or the legs were used to control the robotic motions of left, right, or walk forward, respectively.
Comparison of SSVEP BCI and Eye Tracking for Controlling a Humanoid Robot in a Social Environment
Authors: Kishore Sameer , González-Franco Mar , Hintemüller Christoph , Kapeller Christoph , Guger Christoph , Slater Mel , Blom Kristopher J.
Published: October 2014

Recent advances in humanoid robot technologies have made it possible to inhabit a humanlike form located at a remote place. This allows the participant to interact with others in that space and experience the illusion that the participant is actually present in the remote space. Moreover, with these humanlike forms, it may be possible to induce a full-body ownership illusion, where the robot body is perceived to be one's own. We show that it is possible to induce the full-body ownership illusion over a remote robotic body with a highly robotic appearance. Additionally, our results indicate that even with nonmanual control of a remote robotic body, it is possible to induce feelings of agency and illusions of body ownership. Two established control methods, an SSVEP-based BCI and eye tracking, were tested as a means of controlling the robot's gesturing. Our experience and the results indicate that both methods are tractable for immersive control of a humanoid robot in a social telepresence setting.
Controller Required? The Impact of Natural Mapping on Interactivity, Realism, Presence, and Enjoyment in Motion-Based Video Games
Authors: Shafer Daniel M. , Carbonara Corey P. , Popova Lucy
Published: October 2014

In three experiments with U.S. undergraduates, effects of three levels of naturally mapped control interfaces were compared on a player's sense of presence, interactivity, realism, and enjoyment in video games. The three levels of naturally mapped control interfaces were: kinesic natural mapping (using the player's body as a game controller), incomplete tangible mapping (using a controller in a way similar to a real object), and realistic tangible mapping (using a controller or an object that directly relates to the real-life activity the game simulates). The results show that levels of interactivity, realism, spatial presence, and enjoyment were consistent across all conditions. However, when performing activities such as table tennis or lightsaber dueling with objects in-hand (incomplete tangible or realistic tangible conditions), perceived reality was a more important predictor of spatial presence. When performing the same activities with empty hands, interactivity emerged as the more important direct predictor of spatial presence. Control interface, therefore, matters greatly to the route by which cognitive processing of games takes place and how enjoyment is produced.
Achieving Participant Acceptance of their Avatars
Authors: Blom Kristopher J. , Bellido Rivas Anna I. , Alvarez Xenxo , Cetinaslan Ozan , Oliveira Bruno , Orvalho Verónica , Slater Mel
Published: October 2014

An experiment was carried out to examine the extent to which an avatar can be perceived by people as similar to themselves, including their face and body. The avatar was judged by the participants themselves rather than by third parties. The experiment was organized in two phases. The initial phase consisted of a forced-choice, paired comparison method used to create a ranking of 10 virtual faces in order of preference. This set of faces included a facial mesh, created by a custom software pipeline to rapidly generate avatars that resembled the experimental participants. Six more faces, derived from the participants' own face, were also shown in order to gain insight into the acceptance of a variety of facial similarities. In the second phase, full-body avatars with the most and least preferred faces were presented along with the direct pipeline output. Participants rated their level of satisfaction with those avatars as virtual self-representations and provided the level of perceived resemblance to themselves. The results show that our avatars are perceived to be similar to the self, rated at 7.5/10. Those avatars with faces derived from the participants' face mixed with an ethnically similar face were also rated with high scores. These results differ significantly from how arbitrary avatars are perceived. Therefore, reasonably physically similar avatars can also be expected to be perceived as similar by participants.
Perception-Based Traffic Control for Shared Haptic Virtual Environments
Authors: Schuwerk Clemens , Paggetti Giulia , Chaudhari Rahul , Steinbach Eckehard
Published: October 2014

Shared Haptic Virtual Environments (SHVEs) are often realized using a client–server communication architecture. In this case, a centralized physics engine, running on the server, is used to simulate the object-states in the virtual environment (VE). At the clients, a copy of the VE is maintained and used to render the interaction forces locally, which are then displayed to the human through a haptic device. While this architecture ensures stability in the coupling between the haptic device and the virtual environment, it necessitates a high number of object-state update packets transmitted from the server to the clients to achieve satisfactory force feedback quality. In this paper, we propose a perception-based traffic control scheme to reduce the number of object-state update packets by allowing a variable but not perceivable object-state error at the client. To find a balance between packet rate reduction and force rendering fidelity, our approach uses different error thresholds for the visual and haptic modality, where the haptic thresholds are determined by psychophysical experiments in this paper. Force feedback quality is evaluated with subjective tests for a variety of different traffic control parameter settings. The results show that the proposed scheme reduces the packet rate by up to 97%, compared to communication approaches that work without data reduction. At the same time, the proposed scheme does not degrade the haptic feedback quality significantly. Finally, it outperforms well-known dead reckoning, commonly used in visual-only distributed applications.
Spread of the introduced species Laurencia caduciramulosa (Rhodomelaceae, Rhodophyta) to the northwest Atlantic: A morphological and molecular analysis
Authors: Collado-Vides Ligia , CASSANO VALÉRIA , DÍAZ-LARREA JHOANA , DURAN ALAN , DA SILVA MEDEIROS AMANDA , SENTÍES ABEL , TOYOTA FUJII MUTUE
Published: October 2014

Introduction of species is a common problem in marine environments; marine macroalgae in particular have been reported to be introduced in all oceans, mainly through transport in ballast water, ship fouling and aquarium trade. The majority of the reported alien seaweeds belong to the Rhodophyta. Recently several species of the Laurencia complex have been reported, contributing to an increase of the number of red algae being successfully introduced. Since its description as a new species from Vietnam in 1997, Laurencia caduciramulosa has been spreading steadily with disjunct reports consistently finding specimens close to harbors or major ports. Biscayne Bay, Florida, home to one of the largest ports in USA, and surrounded by the Miami metropolis, is prone to receiving introduced species. This study reports the first introduction of L. caduciramulosa in Biscayne Bay, and its spread to the NW Atlantic. Morphological analysis demonstrated that the specimens collected in Crandon Park, Biscayne Bay, are similar to other specimens of the same species described for Vietnam (original description), Brazil, the Canary Islands and Cuba. Furthermore, molecular analysis using chloroplast-encoded rbcL DNA sequences corroborated the morphological identification. The phylogenetic results suggested that populations in Brazil, Canary Islands and Cuba are recent introductions, while the position of the Florida clade can be interpreted as a distinct and earlier introduction. Due to the level of expertise and knowledge of the Laurencia complex available, we suggest that in the future this group can be used as a model to conduct population genetics analysis of all described introductions in relation to native populations in order to describe patterns of expansion and provide an insight of marine invasions processes.
Turbo-taxonomy: 21 new species of Myzostomida (Annelida)
Authors: SUMMERS MINDI M. , AL-HAKIM IIN INAYAT , ROUSE GREG W.
Published: October 2014

An efficient protocol to identify and describe species of Myzostomida is outlined and demonstrated. This taxonomic approach relies on careful identification (facilitated by an included comprehensive table of available names with relevant geographical and host information) and concise descriptions combined with DNA sequencing, live photography, and accurate host identification. Twenty-one new species are described following these guidelines: Asteromyzostomum grygieri n. sp., Endomyzostoma scotia n. sp., Endomyzostoma neridae n. sp., Mesomyzostoma lanterbecqae n. sp., Hypomyzostoma jasoni n. sp., Hypomyzostoma jonathoni n. sp., Myzostoma debiae n. sp., Myzostoma eeckhauti n. sp., Myzostoma hollandi n. sp., Myzostoma indocuniculus n. sp., Myzostoma josefinae n. sp., Myzostoma kymae n. sp., Myzostoma laurenae n. sp., Myzostoma miki n. sp., Myzostoma pipkini n. sp., Myzostoma susanae n. sp., Myzostoma tertiusi n. sp., Protomyzostomum lingua n. sp., Protomyzostomum roseus n. sp., Pulvinomyzostomum inaki n. sp., and Pulvinomyzostomum messingi n. sp..
Phylogenetic relationships and taxonomic revision of Paranoplocephala Lühe, 1910 sensu lato (Cestoda, Cyclophyllidea, Anoplocephalidae)
Authors: HAUKISALMI VOITTO , HARDMAN LOTTA M. , HOBERG ERIC P. , HENTTONEN HEIKKI
Published: October 2014

An extensive phylogenetic analysis and genus-level taxonomic revision of Paranoplocephala Lühe, 1910-like cestodes (Cyclophyllidea, Anoplocephalidae) are presented. The phylogenetic analysis is based on DNA sequences of two partial mitochondrial genes, i.e. cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1), and includes 51 cestode isolates. The revision concerns all 34 Paranoplocephala-like species considered valid, of which 21 species could be included in the molecular phylogenetic analysis. Based on the phylogenetic relationships and main morphological features, with emphasis on the structure of the scolex, suckers and neck, length of the vagina (relative to the cirrus sac) and distribution of testes, 12 new genera are proposed for cestodes traditionally assigned to Paranoplocephala s. l. This results in 23 new combinations. The new genera are: Gulyaevia n. g., Chionocestus n. g., Microticola n. g., Beringitaenia n. g., Arctocestus n. g., Rauschoides n. g., Eurotaenia n. g., Douthittia n. g., Lemminia n. g., Tenoraia n. g., Rodentocestus n. g. and Cookiella n. g. In addition, Paranoplocephala (s. s.) and Parandrya Gulyaev & Chechulin, 1996 are redescribed; the latter genus is considered valid, although it has been earlier synonymized with Paranoplocephala. A new species (Beringitaenia nanushukensis n. sp.) from Microtus miurus is described. Based on the DNA sequence data, several additional lineages probably representing independent species are identified, but not described as new taxa because of lack of good-quality specimens or absence of reliable morphological differences. The study also presents the first evidence for the phylogenetic position of the monotypic genus Gallegoides Tenora & Mas-Coma, 1978 based on DNA sequence data. A key for the Paranoplocephala-like genera is presented. The patterns of diversity and zoogeography of cestodes representing the “arvicoline clade” (72 species) are complex, involving mechanisms of dispersal, geographic colonization and host switching linking faunas across Eurasia and North America.
New species and subspecies of Rhyacophila (Trichoptera: Rhyacophilidae) from Asia
Authors: KISS OTTÓ
Published: October 2014

New species and subspecies of the genus Rhyacophila (Trichoptera, Rhyacophilidae), i.e. Rhyacophila mikusi n. sp. in the R. yosiiana Group from Taiwan (Republic of China), Rhyacophila wichardi n. sp. in the R. curvata Group, Rhyacophila chayulpa ghunsa new subspecies in the R. chayulpa Group, and Rhyacophila chembo bigu new subspecies in the R. khimbarpa Group from Nepal are described and illustrated with drawings of the genitalia.
A taxonomic revision of the Asian keelback snakes, genus Amphiesma (Serpentes: Colubridae: Natricinae), with description of a new species
Authors: GUO PENG , LIU QIN , ZHANG LIANG , LI JIAN X. , HUANG YU Y. , PYRON R. ALEXANDER
Published: October 2014

The Asian keelback snakes (genus Amphiesma) are a widely distributed group of Old World natricines, inhabiting a variety of niches and exhibiting significant morphological variation. Recent molecular phylogenies suggest that this genus is not monophyletic, and that additional cryptic diversity is also likely present. We conducted a phylogenetic analysis of the group based on 3162 bp of one mitochondrial gene (Cyt. b) and three nuclear genes (C-mos, Rag1, NT3), sampling 18 species in addition to those sequenced in previous works. All analyses consistently show that Amphiesma consists of three distinct, monophyletic lineages with strong support. We divide Amphiesma into three genera, Amphiesma, Hebius, and Herpetoreas. The genus Amphiesma is monotypic, Herpetoreas contains three species, and Hebius comprises the remaining 39 species. On the basis of a combination of molecular analyses and external morphological comparisons, we describe a new species in the Herpetoreas group from China as H. burbrinki sp. nov. Several other species are shown to be non-monophyletic or contain significant levels of intraspecific genetic diversity. Another Old World natricine genera, Xenochrophis is also found to be non-monophyletic. Our results indicate that further taxonomic revisions are needed in Natricinae, at multiple levels.
Note on the genus Morimospasma Ganglbauer with description of two new species from China (Coleoptera: Cerambycidae: Lamiinae)
Authors: XIE GUANGLIN , ZOU XIA , WANG WENKAI
Published: October 2014

The genus Morimospasma Ganglbauer, 1890 is reviewed. Two new species, M. jiangi sp. nov. and M. dalaolingensis sp. nov., are described and illustrated. M. paradoxum Ganglbauer is newly recorded from Anhui, China. Taxonomic status of M. nitidituberculatus Hua is discussed. The Chinese names of M. jiangi sp. nov. and M. dalaolingensis sp.nov. are designated, respectively, as Jiǎngshì Jùliútiānniú and Dàlǎolǐng Jùliútiānniú in Chinese phonetic alphabet. A key to all six species of Morimospasma is provided.
Mesoscale Eddies Affect Near-Surface Turbulent Exchange: Evidence from Lidar and Tower Measurements
Authors: Eder Fabian , Schmidt Marius , Damian Thomas , Träumner Katja , Mauder Matthias
Published: October 2014

The eddy-covariance technique tends to underestimate turbulent heat fluxes, which results in nonclosure of the surface energy balance. This study shows experimental evidence that mesoscale turbulent organized structures, which are inherently not captured by the standard eddy-covariance technique, can affect near-surface turbulent exchange. By using a combined setup of three Doppler wind lidars above a cropland-dominated area in Germany, low-frequency turbulent structures were detected in the surface layer down to a few meters above ground. In addition, data from two micrometeorological stations in the study area were analyzed with respect to energy balance closure. In accordance with several previous studies, the data confirm a strong friction velocity dependence of the energy balance residual. At both stations, the energy balance residual was found to be positively correlated with the vertical moisture gradient in the lower atmospheric boundary layer, but at only one station was it correlated with the temperature gradient. This result indicates that mesoscale transport probably contributes more to the latent heat flux than to the sensible heat flux, but this conclusion depends largely on the measurement site. Moreover, flow distortion due to tower mountings and measurement devices affects the energy balance closure considerably for certain wind directions.
Characterization of Initiation and Growth of Selected Severe Convective Storms over Central Europe with MSG-SEVIRI
Authors: Senf Fabian , Dietzsch Felix , Hünerbein Anja , Deneke Hartwig
Published: October 2014

The early development of severe convective storms over central Europe was investigated on the basis of nine cases from 2012. Using data from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) imaging radiometer aboard a geostationary Meteosat Second Generation (MSG) satellite, dynamical and microphysical properties of developing storms were monitored and combined. Several satellite-based storm properties, for example, cloud-top temperature, cloud-top cooling rate, and cloud particle effective radius, were investigated following the storm tracks. A framework for quantification of uncertainties of along-track properties resulting from tracking errors was also introduced. The majority of studied storms show a distinct maximum in cloud-top cooling rate; the corresponding time was used for track synchronization. The cloud growth phase was divided into an initial updraft intensification period before the maximum cooling and a continued growth period afterward. The initial updraft intensification period is variable and strongly depends on the convection initiation mechanism and detection conditions. The continued growth period is more confined, lasting between 30 and 45 min. The change in anvil size and the resulting average anvil edge velocity were determined from infrared satellite images. As a consequence of mass transport, the anvil edge velocity shows its highest correlation with the cloud-top vertical velocity approximately 20–30 min after the maximum in the cloud-top cooling rate. Larger effective radii of ice crystals were observed for vertically slower-growing clouds. The largest anticorrelation between cloud-top vertical velocity and effective radius was found at a time lag of 20 min after the maximum in cloud-top cooling.
The MJO and Air–Sea Interaction in TOGA COARE and DYNAMO
Authors: de Szoeke Simon P. , Edson James B. , Marion June R. , Fairall Christopher W. , Bariteau Ludovic
Published: October 2014

Dynamics of the Madden–Julian Oscillation (DYNAMO) and Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) observations and reanalysis-based surface flux products are used to test theories of atmosphere–ocean interaction that explain the Madden–Julian oscillation (MJO). Negative intraseasonal outgoing longwave radiation, indicating deep convective clouds, is in phase with increased surface wind stress, decreased solar heating, and increased surface turbulent heat flux—mostly evaporation—from the ocean to the atmosphere. Net heat flux cools the upper ocean in the convective phase. Sea surface temperature (SST) warms during the suppressed phase, reaching a maximum before the onset of MJO convection. The timing of convection, surface flux, and SST is consistent from the central Indian Ocean (70°E) to the western Pacific Ocean (160°E).

Mean surface evaporation observed in TOGA COARE and DYNAMO (110 W m−2) accounts for about half of the moisture supply for the mean precipitation (210 W m−2 for DYNAMO). Precipitation maxima are an order of magnitude larger than evaporation anomalies, requiring moisture convergence in the mean, and on intraseasonal and daily time scales. Column-integrated moisture increases 2 cm before the convectively active phase over the Research Vessel (R/V) Roger Revelle in DYNAMO, in accordance with MJO moisture recharge theory. Local surface evaporation does not significantly recharge the column water budget before convection. As suggested in moisture mode theories, evaporation increases the moist static energy of the column during convection. Rather than simply discharging moisture from the column, the strongest daily precipitation anomalies in the convectively active phase accompany the increasing column moisture.
Optimization of the High-Frequency Radar Sites in the Bering Strait Region
Authors: Panteleev Gleb , Yaremchuk Max , Stroh Jacob , Posey Pamela , Hebert David , Nechaev Dmitri A.
Published: October 2014

Monitoring surface currents by coastal high-frequency radars (HFRs) is a cost-effective observational technique with good prospects for further development. An important issue in improving the efficiency of HFR systems is the optimization of radar positions on the coastline. Besides being constrained by environmental and logistic factors, such optimization has to account for prior knowledge of local circulation and the target quantities (such as transports through certain key sections) with respect to which the radar positions are to be optimized.

In the proposed methodology, prior information of the regional circulation is specified by the solution of the 4D variational assimilation problem, where the available climatological data in the Bering Strait (BS) region are synthesized with dynamical constraints of a numerical model. The optimal HFR placement problem is solved by maximizing the reduction of a posteriori error in the mass, heat, and salt (MHS) transports through the target sections in the region. It is shown that the MHS transports into the Arctic and their redistribution within the Chukchi Sea are best monitored by placing HFRs at Cape Prince of Wales and on Little Diomede Island. Another equally efficient configuration involves placement of the second radar at Sinuk (western Alaska) in place of Diomede. Computations show that 1) optimization of the HFR deployment yields a significant (1.3–3 times) reduction of the transport errors compared to nonoptimal positioning of the radars and 2) error reduction provided by two HFRs is an order of magnitude better than the one obtained from three moorings permanently maintained in the region for the last 5 yr. This result shows a significant advantage of BS monitoring by HFRs compared to the more traditional technique of in situ moored observations. The obtained results are validated by an extensive set of observing system simulation experiments.