Evaluation of Pseudo-Haptic Interactions with Soft Objects in Virtual Environments

This paper proposes a pseudo-haptic feedback method conveying simulated soft surface stiffness information through a visual interface. The method exploits a combination of two feedback techniques, namely visual feedback of soft surface deformation and control of the indenter avatar speed, to convey stiffness information of a simulated surface of a soft object in virtual environments. The proposed method was effective in distinguishing different sizes of virtual hard nodules integrated into the simulated soft bodies. To further improve the interactive experience, the approach was extended creating a multi-point pseudo-haptic feedback system. A comparison with regards to (a) nodule detection sensitivity and (b) elapsed time as performance indicators in hard nodule detection experiments to a tablet computer incorporating vibration feedback was conducted. The multi-point pseudo-haptic interaction is shown to be more time-efficient than the single-point pseudo-haptic interaction. It is noted that multi-point pseudo-haptic feedback performs similarly well when compared to a vibration-based feedback method based on both performance measures elapsed time and nodule detection sensitivity. This proves that the proposed method can be used to convey detailed haptic information for virtual environmental tasks, even subtle ones, using either a computer mouse or a pressure sensitive device as an input device. This pseudo-haptic feedback method provides an opportunity for low-cost simulation of objects with soft surfaces and hard inclusions, as, for example, occurring in ever more realistic video games with increasing emphasis on interaction with the physical environment and minimally invasive surgery in the form of soft tissue organs with embedded cancer nodules. Hence, the method can be used in many low-budget applications where haptic sensation is required, such as surgeon training or video games, either using desktop computers or portable devices, showing reasonably high fidelity in conveying stiffness perception to the user

Multi-proxy assessment of brachiopod shell calcite as a potential archive of seawater temperature and oxygen isotope composition

Most of our knowledge of past seawater temperature history is based on δ18O values of calcium carbonate fossil shells. However, the determination of past temperatures using this proxy requires the knowledge of past seawater δ18O values, which is generally poorly constrained. Other paleothermometers using carbonate archives, such as Mg/Ca ratios and clumped isotopes (Δ47), have been developed to allow for paleotemperatures to be estimated independently and to allow past ocean δ18O values to be calculated using various groups of calcifying organisms. Articulated brachiopod shells are some of the most commonly used archives in studies of past oceanic geochemistry and temperature. They are abundant in the fossil record since the Cambrian, and for decades, their low Mg–calcite mineralogy has been considered relatively resistant to diagenetic alteration. Here, we investigate the potential of brachiopod shells as recorders of seawater temperatures and seawater δ18O values using new brachiopod shell geochemical data by testing multiple well-established or suggested paleothermometers applied to carbonate archives. Modern articulated brachiopod shells covering a wide range of temperatures (−1.9 to 25.5 ∘C), depths (5 to 3431 m) and salinities (33.4 to 37.0 PSU) were analysed for their stable isotope compositions (δ13C, δ18O and Δ47) and their elemental ratios (Mg/Ca, Sr/Ca, Na/Ca and Li/Ca). Our data allowed us to propose a revised oxygen isotope fractionation equation between modern-brachiopod shell calcite and seawater: (1) T = - 5.0 ( ± 0.2 ) ( δ 18 O c - δ 18 O sw ) + 19.4 ( ± 0.4 ) , where δ18Oc is in ‰ VPDB, δ18Osw is in ‰ VSMOW, and T is in ∘C. Our results strongly support the use of clumped isotopes as an alternative temperature proxy but confirm significant offsets relative to the canonical relationship established for other biogenic and abiogenic calcium carbonate minerals. Brachiopod shell Mg/Ca ratios show no relationship with seawater temperatures, indicating that this ratio is a poor recorder of past changes in temperatures, an observation at variance with several previous studies. Despite significant correlations with brachiopod living temperature, brachiopod shell Sr/Ca, Na/Ca and Li/Ca values indicate the influence of environmental and biological factors unrelated to temperature, which undermines their potential as alternative temperature proxies. Kinetic effects (growth rates) could explain most of the deviation of brachiopod shell calcite from expected isotopic equilibrium with seawater and part of the distribution of Sr/Ca, Na/Ca and Li/Ca ratios.</p

Bias in Online Freelance Marketplaces: Evidence from TaskRabbit and Fiverr

Online freelancing marketplaces have grown quickly in recent years. In theory, these sites offer workers the ability to earn money without the obligations and potential social biases associated with traditional employment frameworks. In this paper, we study whether two prominent online freelance marketplaces - TaskRabbit and Fiverr - are impacted by racial and gender bias. From these two platforms, we collect 13,500 worker profiles and gather information about workers' gender, race, customer reviews, ratings, and positions in search rankings. In both marketplaces, we find evidence of bias: we find that gender and race are significantly correlated with worker evaluations, which could harm the employment opportunities afforded to the workers. We hope that our study fuels more research on the presence and implications of discrimination in online environments

Metadata matters: access to image data in the real world

Data sharing is important in the biological sciences to prevent duplication of effort, to promote scientific integrity, and to facilitate and disseminate scientific discovery. Sharing requires centralized repositories, and submission to and utility of these resources require common data formats. This is particularly challenging for multidimensional microscopy image data, which are acquired from a variety of platforms with a myriad of proprietary file formats (PFFs). In this paper, we describe an open standard format that we have developed for microscopy image data. We call on the community to use open image data standards and to insist that all imaging platforms support these file formats. This will build the foundation for an open image data repository

Some cultural consequences in Spain of the Spanish Invasion of Morocco 1859-60

This article argues is a contribution to the study of interrelationships between colonialism, art, and literature in the nineteenth century. The article argues that the Spanish invasion of Morocco in 1859 led to contradictions and tensions within liberal nationalism, not least because of concerns about the tensions between the need for military reassertion of Spain and the respect for the independence of nations. This led to some reconfiguration of Spanish intellectuals' already complex relationship with North Africa and Islam. A major, perhaps surprising consequence of this reconfiguration, was some equation of Moroccan identity with a monotonous surface that was resistant to the gaze. In consequence, the Catalan painter Fortuny's crucial experience of Morocco led him to value near blank surfaces, and thus to make a major contribution to the origins of modern art

Bacteria isolated from lung modulate asthma susceptibility in mice

Asthma is a chronic, non-curable, multifactorial disease with increasing incidence in industrial countries. This study evaluates the direct contribution of lung microbial components in allergic asthma in mice. Germ-Free and Specific-Pathogen-Free mice display similar susceptibilities to House Dust Mice-induced allergic asthma, indicating that the absence of bacteria confers no protection or increased risk to aeroallergens. In early life, allergic asthma changes the pattern of lung microbiota, and lung bacteria reciprocally modulate aeroallergen responsiveness. Primo-colonizing cultivable strains were screened for their immunoregulatory properties following their isolation from neonatal lungs. Intranasal inoculation of lung bacteria influenced the outcome of allergic asthma development: the strain CNCM I 4970 exacerbated some asthma features whereas the pro-Th1 strain CNCM I 4969 had protective effects. Thus, we confirm that appropriate bacterial lung stimuli during early life are critical for susceptibility to allergic asthma in young adults