Design and analysis of a robust, low-cost, highly articulated manipulator enabled by jamming of granular media

Hyper-redundant manipulators can be fragile, expensive, and limited in their flexibility due to the distributed and bulky actuators that are typically used to achieve the precision and degrees of freedom (DOFs) required. Here, a manipulator is proposed that is robust, high-force, low-cost, and highly articulated without employing traditional actuators mounted at the manipulator joints. Rather, local tunable stiffness is coupled with off-board spooler motors and tension cables to achieve complex manipulator configurations. Tunable stiffness is achieved by reversible jamming of granular media, which-by applying a vacuum to enclosed grains-causes the grains to transition between solid-like states and liquid-like ones. Experimental studies were conducted to identify grains with high strength-to-weight performance. A prototype of the manipulator is presented with performance analysis, with emphasis on speed, strength, and articulation. This novel design for a manipulator-and use of jamming for robotic applications in general-could greatly benefit applications such as human-safe robotics and systems in which robots need to exhibit high flexibility to conform to their environments.United States. Defense Advanced Research Projects Agency (Maximum Mobility and Manipulation Program

Global forest land-use change 1990–2005

This report presents the key findings on forest land use and land-use change between 1990 and 2005 from FAO’s 2010 Global Forest Resources Assessment (FRA 2010) Remote Sensing Survey. This survey was the result of a partnership between FAO, its member countries and the European Commission Joint Research Centre (JRC). It is the first report of its kind to present systematic estimates of global forest land use and change. A systematic sample for globally consistent, statistically reliable results The survey is based on a systematic sample of Landsat satellite imagery for the years 1990, 2000 and 2005 located at the intersection of each degree of longitude and latitude. Globally, 15 779 sample sites were processed for land cover and land use. The final number of sample sites analysed was 13 066 after accounting for sites with no data, statistical outliers and nation-specific review and revision (see Annex 1). The area surveyed at each sample site was 10 km × 10 km, providing a sampling intensity of about 1 percent of the global land surface. Forest land use is reported This report focuses on forest land use, not land cover. Forest land use is defined as areas with tree cover, or where management or natural processes will ultimately restore tree cover, and the predominant use is forestry. In some cases, forest land use may include land temporarily without tree cover, for example during cycles of shifting cultivation, forest plantations and even-age forest management. This approach is consistent with the forest definition used in FRA country reports and similar to the classes used in national reports under the United Nations Framework Convention on Climate Change. Forest area The survey estimates the total area of the world’s forests in 2005 at 3.8 billion hectares, or 30 percent of the global land area. Annual global forest area losses were greater between 2000–2005 than 1990–2000 Overall, there was a net decrease in global forest area of 1.7 percent between 1990 and 2005, at an annual rate of change of 0.11 percent. This equates to an annual shift from forest land use to other land uses of 3 million hectares per year between 1990 and 2000 and of 6 million hectares per year between 2000 and 2005. There were regional differences in forest loss and gain Major regional differences were found in the net rates of forest area change; only Asia and North America experienced gains in forest area and all other regions saw net declines. South America had the highest net forest loss and some 3.3 million hectares annually between 1990 and 2005. Africa had the second highest net forest loss – 1.6 million hectares annually – during the same period. Europe, including the Russian Federation, had a net loss of 0.5 million hectares annually and Oceania lost just under 0.1 million hectares annually. North America experienced net gains in forest area of 0.2 million hectares annually, while Asia had a net gain of 1.4 million hectares annually between 1990 and 2005. Forest loss was highest in the tropics For this survey, forests were categorized according to four climatic domains: boreal, subtropical, temperate and tropical. There were significant gains in forest area in the boreal (0.9 million hectares annually) and subtropical (1.1 million hectares annually) between 1990 and 2005. There was also a net gain in forest area in the temperate domain of 0.9 million hectares annually over the same period. In contrast, the tropical domain had a net loss of forest area of 6.8 million hectares annually between 1990 and 2005. This net reduction in forest land use was nearly 2.5 times the net forest area gained in the other three domains combined.JRC.H.3 - Forest Resources and Climat

Deweyan tools for inquiry and the epistemological context of critical pedagogy

This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated

Assessing uncertainty and complexity in regional-scale crop model simulations

Crop models are imperfect approximations to real world interactions between biotic and abiotic factors. In some situations, the uncertainties associated with choices in model structure, model inputs and parameters can exceed the spatiotemporal variability of simulated yields, thus limiting predictability. For Indian groundnut, we used the General Large Area Model for annual crops (GLAM) with an existing framework to decompose uncertainty, to first understand how skill changes with added model complexity, and then to determine the relevant uncertainty sources in yield and other prognostic variables (total biomass, leaf area index and harvest index). We developed an ensemble of simulations by perturbing GLAM parameters using two different input meteorology datasets, and two model versions that differ in the complexity with which they account for assimilation. We found that added complexity improved model skill, as measured by changes in the root mean squared error (RMSE), by 5-10% in specific pockets of western, central and southern India, but that 85% of the groundnut growing area either did not show improved skill or showed decreased skill from such added complexity. Thus, adding complexity or using overly complex models at regional or global scales should be exercised with caution. Uncertainty analysis indicated that, in situations where soil and air moisture dynamics are the major determinants of productivity, predictability in yield is high. Where uncertainty for yield is high, the choice of weather input data was found critical for reducing uncertainty. However, for other prognostic variables (including leaf area index, total biomass and the harvest index) parametric uncertainty was generally the most important source, with a contribution of up to 90% in some cases, suggesting that regional-scale data additional to yield to constrain model parameters is needed. Our study provides further evidence that regional-scale studies should explicitly quantify multiple uncertainty sources

Silent progression in disease activity-free relapsing multiple sclerosis.

ObjectiveRates of worsening and evolution to secondary progressive multiple sclerosis (MS) may be substantially lower in actively treated patients compared to natural history studies from the pretreatment era. Nonetheless, in our recently reported prospective cohort, more than half of patients with relapsing MS accumulated significant new disability by the 10th year of follow-up. Notably, "no evidence of disease activity" at 2 years did not predict long-term stability. Here, we determined to what extent clinical relapses and radiographic evidence of disease activity contribute to long-term disability accumulation.MethodsDisability progression was defined as an increase in Expanded Disability Status Scale (EDSS) of 1.5, 1.0, or 0.5 (or greater) from baseline EDSS = 0, 1.0-5.0, and 5.5 or higher, respectively, assessed from baseline to year 5 (±1 year) and sustained to year 10 (±1 year). Longitudinal analysis of relative brain volume loss used a linear mixed model with sex, age, disease duration, and HLA-DRB1*15:01 as covariates.ResultsRelapses were associated with a transient increase in disability over 1-year intervals (p = 0.012) but not with confirmed disability progression (p = 0.551). Relative brain volume declined at a greater rate among individuals with disability progression compared to those who remained stable (p < 0.05).InterpretationLong-term worsening is common in relapsing MS patients, is largely independent of relapse activity, and is associated with accelerated brain atrophy. We propose the term silent progression to describe the insidious disability that accrues in many patients who satisfy traditional criteria for relapsing-remitting MS. Ann Neurol 2019;85:653-666

A Preliminary Analysis of Combined Liver Resection With New Chemotherapy for Synchronous and Metachronous Colorectal Liver Metastasis

ObjectiveTo compare the survival between patients with synchronous and metachronous colorectal liver metastases after hepatectomy with new generation of perioperative chemotherapy.MethodsFrom October 2002 to January 2008, patients receiving hepatectomy for synchronous or metachronous colorectal liver metastasis were studied retrospectively.ResultsFifty-five patients (synchronous group = 35, metachronous group = 20) underwent hepatectomy for colorectal liver metastases. Besides younger age with male predominance, patients in the synchronous group had more tumour multinodularity and bilobe liver involvement. They had received less hepatic curative hepatectomy (81.1% vs. 100%) with a higher rate of peri-operative chemotherapy (91.4% vs. 50%) and postoperative morbidity (25.7% vs. 0%). However both groups had no statistical significant difference in median overall survival (OS) and disease free survival (DFS). Inferior OS and DFS were observed in the synchronous group for patients who had no peri-operative chemotherapy or those showing poor response to chemotherapy. The most favourable OS is observed in both groups after performing globally curative hepatectomy.ConclusionSynchronous colorectal liver metastasis is not a poor prognostic factor for survival when compared with the metachronous metastasis. Globally curative hepatectomy in combination of new generation of chemotherapy is recommended for the management of resectable colorectal liver metastasis

Trueness and precision of the real-time RT-PCR method for quantifying the chronic bee paralysis virus genome in bee homogenates evaluated by a comparative inter-laboratory study

The Chronic bee paralysis virus (CBPV) is the aetiological agent of chronic bee paralysis, a contagious disease associated with nervous disorders in adult honeybees leading to massive mortalities in front of the hives. Some of the clinical signs frequently reported, such as trembling, may be confused with intoxication syndromes. Therefore, laboratory diagnosis using real-time PCR to quantify CBPV loads is used to confirm disease. Clinical signs of chronic paralysis are usually associated with viral loads higher than 108 copies of CBPV genome copies per bee (8 log(10) CBPV/bee). This threshold is used by the European Union Reference Laboratory for Bee Health to diagnose the disease. In 2015, the accuracy of measurements of three CBPV loads (5, 8 and 9 log(10) CBPV/bee) was assessed through an inter-laboratory study. Twenty-one participants, including 16 European National Reference Laboratories, received 13 homogenates of CBPV-infected bees adjusted to the three loads. Participants were requested to use the method usually employed for routine diagnosis. The quantitative results (n = 270) were analysed according to international standards NF ISO 13528 (2015) and NF ISO 5725-2 (1994). The standard deviations of measurement reproducibility (S-R) were 0.83, 1.06 and 1.16 at viral loads 5, 8 and 9 log(10) CBPV/bee, respectively. The inter-laboratory confidence of viral quantification (+/- 1.96 S-R) at the diagnostic threshold (8 log(10) CBPV/bee) was +/- 2.08 log(10) CBPV/bee. These results highlight the need to take into account the confidence of measurements in epidemiological studies using results from different laboratories. Considering this confidence, viral loads over 6 log(10) CBPV/bee may be considered to indicate probable cases of chronic paralysis

We’re Going Live When?! Implementing Digital Commons at Texas A&M University-Commerce

Texas A&M University-Commerce implemented Digital Commons as their institutional repository in Summer 2021. This is the first institutional repository launched at our university. The Implementation Committee divided into two groups, Scholarly Communications and Special Collections and University Archives, and each had unique needs and requirements. This included developing an organizational structure, workflows, creating policies, usage permissions, and identifying content. This was a complex project for our small staff, but we were able to launch successfully by our deadline. This session focuses on the most important decisions made in order to launch Digital Commons in under a month. We will discuss our implementation workflows, processes and challenges that were met. We will wrap up by discussing what worked and what did not work

Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death