5,184 research outputs found
Emerging concept of income presentation
This article reviews the development of income presentation found in the authoritative accounting pronouncements since 1941. During this period, within the historical cost reporting model for presentation of income, emphasis has shifted from the all-inclusive concept of net income and the current operating performance concept to a hybrid approach which substantially incorporates the two concepts
Nearly free electrons in the layered oxide superconductor Ag5Pb2O6
We present first measurements of quantum oscillations in the layered oxide
superconductor
Ag5Pb2O6. From a detailed angular and temperature dependent study of the dHvA
effect we determine the electronic structure and demonstrate that the electron
masses are very light, m^* is approximately equalt to 1.2 m_e. The Fermi
surface we observe is essentially that expected of nearly-free electrons -
establishing
Ag5Pb2O6 as the first known example of a monovalent, nearly-free electron
superconductor at ambient pressure.Comment: 4 pages, 3 figure
Hydrologic and Erosion Responses to Wildfire Along the Rangeland-Xeric Forest Continuum in the Western US: A Review and Model of Hydrologic Vulnerability
The recent increase in wildfire activity across the rangeland–xeric forest continuum in the western United States has landscape-scale consequences in terms of runoff and erosion. Concomitant cheatgrass (Bromus tectorum L.) invasions, plant community transitions and a warming climate in recent decades along grassland–shrubland–woodland–xeric forest transitions have promoted frequent and large wildfires, and continuance of the trend appears likely if warming climate conditions prevail. These changes potentially increase overall hydrologic vulnerability by spatially and temporally increasing soil exposure to runoff and erosion processes. Plot and hillslope-scale studies demonstrate burning may increase event runoff or erosion by factors of 2–40 over small-plot scales and more than 100-fold over large-plot to hillslope scales. Reports of flooding and debris flow events from rangelands and xeric forests following burning show the potential risk to natural resources, property, infrastructure and human life. We present a conceptual model for evaluating post-fire hydrologic vulnerability and risk. We suggest that post-fire risk assessment of potential hydrologic hazards should adopt a probability-based approach that considers varying site susceptibility in conjunction with a range of potential storms and that determines the hydrologic response magnitudes likely to affect values-at-risk. Our review suggests that improved risk assessment requires better understanding in several key areas including quantification of interactions between varying storm intensities and measures of site susceptibility, the varying effects of soil water repellency, and the spatial scaling of post-fire hydrologic response across rangeland–xeric forest plant communities
Thermal noise suppression: how much does it cost?
In order to stabilize the behavior of noisy systems, confining it around a
desirable state, an effort is required to suppress the intrinsic noise. This
noise suppression task entails a cost. For the important case of thermal noise
in an overdamped system, we show that the minimum cost is achieved when the
system control parameters are held constant: any additional deterministic or
random modulation produces an increase of the cost. We discuss the implications
of this phenomenon for those overdamped systems whose control parameters are
intrinsically noisy, presenting a case study based on the example of a Brownian
particle optically trapped in an oscillating potential.Comment: 6 page
Leveraging arbitrary mobile sensor trajectories with shallow recurrent decoder networks for full-state reconstruction
Sensing is one of the most fundamental tasks for the monitoring, forecasting
and control of complex, spatio-temporal systems. In many applications, a
limited number of sensors are mobile and move with the dynamics, with examples
including wearable technology, ocean monitoring buoys, and weather balloons. In
these dynamic systems (without regions of statistical-independence), the
measurement time history encodes a significant amount of information that can
be extracted for critical tasks. Most model-free sensing paradigms aim to map
current sparse sensor measurements to the high-dimensional state space,
ignoring the time-history all together. Using modern deep learning
architectures, we show that a sequence-to-vector model, such as an LSTM (long,
short-term memory) network, with a decoder network, dynamic trajectory
information can be mapped to full state-space estimates. Indeed, we demonstrate
that by leveraging mobile sensor trajectories with shallow recurrent decoder
networks, we can train the network (i) to accurately reconstruct the full state
space using arbitrary dynamical trajectories of the sensors, (ii) the
architecture reduces the variance of the mean-square error of the
reconstruction error in comparison with immobile sensors, and (iii) the
architecture also allows for rapid generalization (parameterization of
dynamics) for data outside the training set. Moreover, the path of the sensor
can be chosen arbitrarily, provided training data for the spatial trajectory of
the sensor is available. The exceptional performance of the network
architecture is demonstrated on three applications: turbulent flows, global
sea-surface temperature data, and human movement biomechanics.Comment: 11 pages, 5 figures, 2 table
Cisplatin and fluorouracil with or without panitumumab in patients with recurrent or metastatic squamous-cell carcinoma of the head and neck (SPECTRUM): an open-label phase 3 randomised trial
Background: Previous trials have shown that anti-EGFR monoclonal antibodies can improve clinical outcomes of patients with recurrent or metastatic squamous-cell carcinoma of the head and neck (SCCHN). We assessed the efficacy and safety of panitumumab combined with cisplatin and fluorouracil as first-line treatment for these patients.
Methods: This open-label phase 3 randomised trial was done at 126 sites in 26 countries. Eligible patients were aged at least 18 years; had histologically or cytologically confi rmed SCCHN; had distant metastatic or locoregionally recurrent disease, or both, that was deemed to be incurable by surgery or radiotherapy; had an Eastern Cooperative Oncology Group performance status of 1 or less; and had adequate haematological, renal, hepatic, and cardiac function. Patients were randomly assigned according to a computer-generated randomisation sequence (1:1; stratifi ed by previous treatment, primary tumour site, and performance status) to one of two groups. Patients in both groups received up to six 3-week cycles of intravenous cisplatin (100 mg/m(2) on day 1 of each cycle) and fl uorouracil (1000 mg/m(2) on days 1-4 of each cycle); those in the experimental group also received intravenous panitumumab (9 mg/kg on day 1 of each cycle). Patients in the experimental group could choose to continue maintenance panitumumab every 3 weeks. The primary endpoint was overall survival and was analysed by intention to treat. In a prospectively defi ned retrospective analysis, we assessed tumour human papillomavirus (HPV) status as a potential predictive biomarker of outcomes with a validated p16-INK4A (henceforth, p16) immunohistochemical assay. Patients and investigators were aware of group assignment; study statisticians were masked until primary analysis; and the central laboratory assessing p16 status was masked to identifi cation of patients and treatment. This trial is registered with ClinicalTrials. gov, number NCT00460265.
Findings: Between May 15, 2007, and March 10, 2009, we randomly assigned 657 patients: 327 to the panitumumab group and 330 to the control group. Median overall survival was 11.1 months (95% CI 9.8-12.2) in the panitumumab group and 9.0 months (8.1-11.2) in the control group (hazard ratio [HR] 0.873, 95% CI 0.729-1.046; p = 0.1403). Median progression-free survival was 5.8 months (95% CI 5.6-6.6) in the panitumumab group and 4.6 months (4.1-5.4) in the control group (HR 0.780, 95% CI 0.659-0.922; p = 0.0036). Several grade 3 or 4 adverse events were more frequent in the panitumumab group than in the control group: skin or eye toxicity (62 [19%] of 325 included in safety analyses vs six [2%] of 325), diarrhoea (15 [5%] vs four [1%]), hypomagnesaemia (40 [12%] vs 12 [4%]), hypokalaemia (33 [10%] vs 23 [7%]), and dehydration (16 [5%] vs seven [2%]). Treatment-related deaths occurred in 14 patients (4%) in the panitumumab group and eight (2%) in the control group. Five (2%) of the fatal adverse events in the panitumumab group were attributed to the experimental agent. We had appropriate samples to assess p16 status for 443 (67%) patients, of whom 99 (22%) were p16 positive. Median overall survival in patients with p16-negative tumours was longer in the panitumumab group than in the control group (11.7 months [95% CI 9.7-13.7] vs 8.6 months [6.9-11.1]; HR 0.73 [95% CI 0.58-0.93]; p = 0.0115), but this difference was not shown for p16-positive patients (11.0 months [7.3-12.9] vs 12.6 months [7.7-17.4]; 1.00 [0.62-1.61]; p = 0.998). In the control group, p16-positive patients had numerically, but not statistically, longer overall survival than did p16-negative patients (HR 0.70 [95% CI 0.47-1.04]).
Interpretation: Although the addition of panitumumab to chemotherapy did not improve overall survival in an unselected population of patients with recurrent or metastatic SCCHN, it improved progression-free survival and had an acceptable toxicity profile. p16 status could be a prognostic and predictive marker in patients treated with panitumumab and chemotherapy. Prospective assessment will be necessary to validate our biomarker findings
Special Libraries, May 1916
Volume 7, Issue 5https://scholarworks.sjsu.edu/sla_sl_1916/1004/thumbnail.jp
First Recorded Mating Flight of the Hypogeic Ant, Acropyga epedana, with its Obligate Mutualist Mealybug, Rhizoecus colombiensis
On 26-July, 2005 a mating aggregation of Acropyga epedana Snelling (Hymenoptera: Formicidae) was observed in the Chiricahua Mountains in south-eastern Arizona. This is the first record of a mating flight of A. epedana, the only nearctic member of this pantropical genus. Mating behavior was observed, newly mated queens were collected, and a complete colony was excavated. New information is reported on the natural history and mating behavior of the species. The identity of a mealybug mutualist, Rhizoecus colombiensis (Homoptera: Rhizoecinae) is confirmed. Reproductive females participating in flights all carried mealybugs between their mandibles, indicating a vertical transfer of mealybugs with their ant hosts. No captured foundresses survived long in captivity, most likely due to the death of their mealybugs. The colony excavated had a single queen, though polygyny is common in the genus. Nearly all workers within the nest were heavily parasitized by mites, although males or gynes were not parasitized. These natural history observations are discussed with regard to this poorly understood mutualistic relationship between Acropyga ants and their mealybug partners
Polymorphic organization in a planktonic graptoloid (Hemichordata: Pterobranchia) colony of Late Ordovician age
Graptolites are common fossils in Early Palaeozoic strata, but little is known of their soft-part anatomy. However, we report a long-overlooked specimen of Dicranograptus aff. ramosus from Late Ordovician strata of southern Scotland that preserves a strongly polymorphic, recalcitrant, organic-walled network hitherto unseen in graptoloid graptolites. This network displays three morphologies: proximally, a strap-like pattern, likely of flattened tubes; these transform distally into isolated, hourglass-shaped structures; then, yet more distally, revert to a (simpler) strap-like pattern. The network most likely represents a stolon-like system, hitherto unknown in graptoloids, that connected individual zooids. Its alternative interpretation, as colonial xenobionts that infested a graptoloid colony and mimicked its architecture, is considered less likely on taphonomic and palaeobiological grounds. Such polymorphism is not known in non-graptolite pterobranchs, which are less diverse and morphologically more conservative: a division of labour between graptoloid zooids for such functions as feeding, breeding and rhabdosome construction may have been the key to their remarkable evolutionary success
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