4,118 research outputs found

    Discovery-led refinement in e-discovery investigations: sensemaking, cognitive ergonomics and system design.

    Get PDF
    Given the very large numbers of documents involved in e-discovery investigations, lawyers face a considerable challenge of collaborative sensemaking. We report findings from three workplace studies which looked at different aspects of how this challenge was met. From a sociotechnical perspective, the studies aimed to understand how investigators collectively and individually worked with information to support sensemaking and decision making. Here, we focus on discovery-led refinement; specifically, how engaging with the materials of the investigations led to discoveries that supported refinement of the problems and new strategies for addressing them. These refinements were essential for tractability. We begin with observations which show how new lines of enquiry were recursively embedded. We then analyse the conceptual structure of a line of enquiry and consider how reflecting this in e-discovery support systems might support scalability and group collaboration. We then focus on the individual activity of manual document review where refinement corresponded with the inductive identification of classes of irrelevant and relevant documents within a collection. Our observations point to the effects of priming on dealing with these efficiently and to issues of cognitive ergonomics at the human–computer interface. We use these observations to introduce visualisations that might enable reviewers to deal with such refinements more efficiently

    Social complexity in bees is not sufficient to explain lack of reversions to solitary living over long time scales

    Get PDF
    BackgroundThe major lineages of eusocial insects, the ants, termites, stingless bees, honeybees and vespid wasps, all have ancient origins (> or = 65 mya) with no reversions to solitary behaviour. This has prompted the notion of a 'point of no return' whereby the evolutionary elaboration and integration of behavioural, genetic and morphological traits over a very long period of time leads to a situation where reversion to solitary living is no longer an evolutionary option.ResultsWe show that in another group of social insects, the allodapine bees, there was a single origin of sociality > 40 mya. We also provide data on the biology of a key allodapine species, Halterapis nigrinervis, showing that it is truly social. H. nigrinervis was thought to be the only allodapine that was not social, and our findings therefore indicate that there have been no losses of sociality among extant allodapine clades. Allodapine colony sizes rarely exceed 10 females per nest and all females in virtually all species are capable of nesting and reproducing independently, so these bees clearly do not fit the 'point of no return' concept.ConclusionWe argue that allodapine sociality has been maintained by ecological constraints and the benefits of alloparental care, as opposed to behavioural, genetic or morphological constraints to independent living. Allodapine brood are highly vulnerable to predation because they are progressively reared in an open nest (not in sealed brood cells), which provides potentially large benefits for alloparental care and incentives for reproductives to tolerate potential alloparents. We argue that similar vulnerabilities may also help explain the lack of reversions to solitary living in other taxa with ancient social origins.Luke B. Chenoweth, Simon M. Tierney, Jaclyn A. Smith, Steven J.B. Cooper and Michael P. Schwar

    Numerical Study of the Two Color Attoworld

    Full text link
    We consider QCD at very low temperatures and non-zero quark chemical potential from lattice Monte Carlo simulations of the two-color theory in a very small spatial volume (the attoscale). In this regime the quark number rises in discrete levels in qualitative agreement with what is found analytically at one loop on S3xS1 with radius R_S3 << 1/{\Lambda}_QCD. The detailed level degeneracy, however, cannot be accounted for using weak coupling arguments. At each rise in the quark number there is a corresponding spike in the Polyakov line, also in agreement with the perturbative results. In addition the quark number susceptibility shows a similar behaviour to the Polyakov line and appears to be a good indicator of a confinement-deconfinement type of transition.Comment: 18 pages, 10 figure

    Ergodic Jacobi matrices and conformal maps

    Full text link
    We study structural properties of the Lyapunov exponent γ\gamma and the density of states kk for ergodic (or just invariant) Jacobi matrices in a general framework. In this analysis, a central role is played by the function w=−γ+iπkw=-\gamma+i\pi k as a conformal map between certain domains. This idea goes back to Marchenko and Ostrovskii, who used this device in their analysis of the periodic problem

    Psychological Encouragement for High School Students in Preparation for Online Learning During Covid-19

    Get PDF
    Psychosocial is commonly defined as referring to a relationship that is close in both psychological and social factors. Emotional and cognitive development, as well as social factors such as interpersonal relationships and the community in which a person lives all influence a person's psychological well-being. Psychosocial is focused on the interpersonal aspects that exist alongside psychological aspects (thoughts, emotions, and behavior) (social relations, traditions and culture). Initiated psychological encouragement (commonly referred to as DPA) is also known as PFA (PFA). Psychosocial encouragement is a type of DPA. DPA aims to reduce the detrimental effects of stress, to help individuals recover from disasters, and to assist in the process of their return to normal. A crisis situation is an ongoing (or expected) event that places people, groups, communities, or societies in an unstable and dangerous position, which then impacts those people, groups, or societies. There are both positive and negative impacts that teachers, students, and also parents have to face and deal with during a COVID-19 pandemic. Stress and pressure can arise naturally, for everyone, when someone is in an unpleasant/crisis situation. Emotional expressions, such as crying in children aged 0-3 years, or other non-adaptive behavior, such as aggressive or tantrums, are common indicators of stress in students (venting anger or excessive emotional outbursts at a certain age because there are unfulfilled wants or needs)

    Ekplorasi Etnomatematika Ulos Tikar-Tikar pada Materi Himpunan

    Get PDF
    The purpose of this study was to explore and find the set material on ulos mats made by ulos craftsmen in Pematangsiantar city which are mostly found as home industries. The research method used in this research is descriptive qualitative with an ethnographic approach. Data obtained by domain analysis and taxonomic analysis. The results of the study obtained the terms Kasuksak, flies, binoculars, weft thread, throwing thread, wool thread, lotak, Ulos Mats which can be used in mathematics lessons on set material. In conclusion, the exploration of ulos mats provides a fun, new nuanced mathematics learning experience, which students can find in everyday life and invites students to get to know the culture around them. &nbsp; Keywords: Yarn, Sets, Mathematics, Ulos mat

    Pretransplant assessment of human liver grafts by plasma lecithin: cholesterol acyltransferase (LCAT) activity in multiple organ donors.

    Get PDF
    In spite of the improved outcome of orthotopic liver transplantation (OLTx), primary graft nonfunction remains one of the life-threatening problems following OLTx. The purpose of this study was to evaluate plasma lecithin: cholesterol acyltransferase (LCAT) activity in multiple organ donors as a predictor of liver allograft viability prior to OLTx. Thirty-nine donors were studied during a 5-month period between April and August 1988. Allograft hepatectomy was performed using a rapid technique or its minor modification with hilar dissections, and the allografts were stored cold (4 degrees C) in University of Wisconsin (UW) solution. Early post-transplant allograft function was classified as good, fair, or poor, according to the highest SGOT, SGPT, and prothrombin time within 5 days following OLTx. Procurement records were reviewed to identify donor data, which included conventional liver function tests, duration of hospital stay, history of cardiac arrest, and graft ischemic time. Blood samples from the donors were drawn immediately prior to aortic crossclamp, and from these plasma LCAT activity was determined. Plasma LCAT activity of all donors was significantly lower than that of healthy controls (12.4 +/- 8.0 vs 39.2 +/- 13.3 micrograms/ml per hour, P less than 0.01). LCAT activity (16.4 +/- 8.3 micrograms/ml per hour) in donors of grafts with good function was significantly higher than that in those with fair (8.6 +/- 4.5 micrograms/ml per hour, P less than 0.01) or poor (7.3 +/- 2.4 micrograms/ml per hour, P less than 0.01) function.(ABSTRACT TRUNCATED AT 250 WORDS

    Revisiting protein aggregation as pathogenic in sporadic Parkinson and Alzheimer diseases.

    Get PDF
    The gold standard for a definitive diagnosis of Parkinson disease (PD) is the pathologic finding of aggregated α-synuclein into Lewy bodies and for Alzheimer disease (AD) aggregated amyloid into plaques and hyperphosphorylated tau into tangles. Implicit in this clinicopathologic-based nosology is the assumption that pathologic protein aggregation at autopsy reflects pathogenesis at disease onset. While these aggregates may in exceptional cases be on a causal pathway in humans (e.g., aggregated α-synuclein in SNCA gene multiplication or aggregated β-amyloid in APP mutations), their near universality at postmortem in sporadic PD and AD suggests they may alternatively represent common outcomes from upstream mechanisms or compensatory responses to cellular stress in order to delay cell death. These 3 conceptual frameworks of protein aggregation (pathogenic, epiphenomenon, protective) are difficult to resolve because of the inability to probe brain tissue in real time. Whereas animal models, in which neither PD nor AD occur in natural states, consistently support a pathogenic role of protein aggregation, indirect evidence from human studies does not. We hypothesize that (1) current biomarkers of protein aggregates may be relevant to common pathology but not to subgroup pathogenesis and (2) disease-modifying treatments targeting oligomers or fibrils might be futile or deleterious because these proteins are epiphenomena or protective in the human brain under molecular stress. Future precision medicine efforts for molecular targeting of neurodegenerative diseases may require analyses not anchored on current clinicopathologic criteria but instead on biological signals generated from large deeply phenotyped aging populations or from smaller but well-defined genetic-molecular cohorts

    Misaligned spin and orbital axes cause the anomalous precession of DI Herculis

    Full text link
    The orbits of binary stars precess as a result of general relativistic effects, forces arising from the asphericity of the stars, and forces from additional stars or planets in the system. For most binaries, the theoretical and observed precession rates are in agreement. One system, however -- DI Herculis -- has resisted explanation for 30 years. The observed precession rate is a factor of four slower than the theoretical rate, a disagreement that once was interpreted as evidence for a failure of general relativity. Among the contemporary explanations are the existence of a circumbinary planet and a large tilt of the stellar spin axes with respect to the orbit. Here we report that both stars of DI Herculis rotate with their spin axes nearly perpendicular to the orbital axis (contrary to the usual assumption for close binary stars). The rotationally induced stellar oblateness causes precession in the direction opposite to that of relativistic precession, thereby reconciling the theoretical and observed rates.Comment: Nature, in press [11 pg

    A GMSK VHF-uplink/UHF-downlink transceiver for the CubeSat missions: Thermo-functional performance

    Get PDF
    © 2018, CEAS. Functional and thermal performance characteristics of a very high frequency/ultra high frequency (VHF/UHF) transceiver based on Gaussian minimum shift keying (GMSK) modulation are presented. The transceiver has been designed for CubeSats telemetry and commanding needs or low rate data download. The design is validated at 27 dBm, 30 dBm and 33 dBm transmitting powers over −20 ∘C to +51 ∘C. Under these thermal conditions, the transmitter spurious dynamic response shows little if any change and the average sensitivity of receiver at the 12 dB signal noise and distortion (SINAD) is −116.7 dBm at 140 MHz and −116.78 dBm at 149.98 MHz. The transmitter and receiver frequencies are stable and the current consumption as well the output RF levels are steady. The design has been verified against a simulation model which allows system tradeoff analysis. The measurements demonstrate the transceiver made with commercial grade parts has dependable performance at the low earth altitudes and orbital heating conditions
    • …
    corecore