5,001 research outputs found
Cardiac myoglobin deficit has evolved repeatedly in teleost fishes
Peer reviewedPublisher PD
Colloquy
At present, our system of criminal law administration has a considerable Rube Goldberg quality to it. Once the system decides to imprison a particular defendant--if we except from the generalization the couple of states that recently changed their laws in fundamental respects--the judge naturally asks himself what will happen when this man goes to prison. The answer is that the convicted offender will sit in prison for as long as the parole board wants him to. The judge must next consider whether any constraints exist on the parole board\u27s decisions on when to release people from prison. In a third of the statutory sentences the judge can specify that the defendant must remain imprisoned for up to one third or one half of the time to which he is sentenced. The question then becomes how long the judge wants a particular defendant to stay in prison. He knows that a nine-year sentence will mean minimum parole eligibility after three years,and that the parole board releases prisoners on their first eligibility date in eighty-five percent of the cases. Therefore, judges purpose-fully inflate sentences to discount for their knowledge that the parole board decreases the sentences which a judge imposes
Criminal Sovereignty: Understanding North Korea\u27s Illicit International Activities
This monograph examines Office Number 39’s origins, organizational structure, and activities in order to develop a more calibrated strategy and policy to meet the North Korean challenge. This monograph focuses on Office Number 39\u27s key illicit activities— to include manufacture and distribution of illegal drugs, the counterfeiting of U.S. currency, and the manufacture and distribution of counterfeit cigarettes. Finally, as Kim Jong-Il grows frailer, assessing how his successor may continue or alter Office Number 39’s activities is also examined.https://press.armywarcollege.edu/monographs/1348/thumbnail.jp
Integrated Flight and Propulsion Control for Novel Rotorcraft
Distributed Electric Propulsion (DEP) has increased the design space for aerospace vehicles, especially those categorized as eVTOL (Electric Vertical Take-Off and Landing). This new class of vehicles not only looks different from the typical airplane or helicopter, but functions differently as well. A robust understanding of how the vehicle is controlled in both nominal and off-nominal modes will frame the approach to certification for private and commercial VTOL aircraft.
Embry-Riddle Aeronautical University’s Eagle Flight Research Center (EFRC) is researching how the various methods of DEP thrust control apply to larger eVTOL vehicle operation. Researchers will utilize a mixture of flight dynamic simulation and physical testing in collaboration with FAA experts in rotorcraft handling qualities certification. Outcomes of the research include the characterization of various DEP thrust and moment control methods and how this maps to certifiable vehicle-level attributes like handling qualities in nominal and degraded flight modes. A prototype will be built and tested showing the ability of a quad-rotor vehicle to continue flight after the loss of thrust by failure of one rotor.
It is anticipated that a better understanding of the DEP units will help inform the process of certification for the emerging market of urban air mobility vehicles. The data obtained from testing will be utilized to define the possible performance parameters, which will aid in developing appropriate means of compliance for advanced fly-by-wire N-rotor eVTOL vehicles
On Embeddability of Buses in Point Sets
Set membership of points in the plane can be visualized by connecting
corresponding points via graphical features, like paths, trees, polygons,
ellipses. In this paper we study the \emph{bus embeddability problem} (BEP):
given a set of colored points we ask whether there exists a planar realization
with one horizontal straight-line segment per color, called bus, such that all
points with the same color are connected with vertical line segments to their
bus. We present an ILP and an FPT algorithm for the general problem. For
restricted versions of this problem, such as when the relative order of buses
is predefined, or when a bus must be placed above all its points, we provide
efficient algorithms. We show that another restricted version of the problem
can be solved using 2-stack pushall sorting. On the negative side we prove the
NP-completeness of a special case of BEP.Comment: 19 pages, 9 figures, conference version at GD 201
Clastic polygonal networks around Lyot crater, Mars: Possible formation mechanisms from morphometric analysis
Polygonal networks of patterned ground are a common feature in cold-climate environments. They can form through the thermal contraction of ice-cemented sediment (i.e. formed from fractures), or the freezing and thawing of ground ice (i.e. formed by patterns of clasts, or ground deformation). The characteristics of these landforms provide information about environmental conditions. Analogous polygonal forms have been observed on Mars leading to inferences about environmental conditions. We have identified clastic polygonal features located around Lyot crater, Mars (50°N, 30°E). These polygons are unusually large ( > 100 m diameter) compared to terrestrial clastic polygons, and contain very large clasts, some of which are up to 15 metres in diameter. The polygons are distributed in a wide arc around the eastern side of Lyot crater, at a consistent distance from the crater rim. Using high-resolution imaging data, we digitised these features to extract morphological information. These data are compared to existing terrestrial and Martian polygon data to look for similarities and differences and to inform hypotheses concerning possible formation mechanisms. Our results show the clastic polygons do not have any morphometric features that indicate they are similar to terrestrial sorted, clastic polygons formed by freeze-thaw processes. They are too large, do not show the expected variation in form with slope, and have clasts that do not scale in size with polygon diameter. However, the clastic networks are similar in network morphology to thermal contraction cracks, and there is a potential direct Martian analogue in a sub-type of thermal contraction polygons located in Utopia Planitia. Based upon our observations, we reject the hypothesis that polygons located around Lyot formed as freeze-thaw polygons and instead an alternative mechanism is put forward: they result from the infilling of earlier thermal contraction cracks by wind-blown material, which then became compressed and/or cemented resulting in a resistant fill. Erosion then leads to preservation of these polygons in positive relief, while later weathering results in the fracturing of the fill material to form angular clasts. These results suggest that there was an extensive area of ice-rich terrain, the extent of which is linked to ejecta from Lyot crater
The impact of predation by marine mammals on Patagonian toothfish longline fisheries
Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of “depredation hot spots” can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources
Recommended from our members
Homogeneous catalysis under ultra-dilute conditions: TAML/NaClO oxidation of persistent metaldehyde
This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of the American Chemical Society, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/jacs.6b11145TAML activators enable homogenous oxidation catalysis where the catalyst and substrate (S) are ultra-dilute (pM–low μM) and the oxidant is very dilute (high nM–low mM). Water contamination by exceptionally persistent micropollutants (MPs), including metaldehyde (Met), provides an ideal space for determining the characteristics and utilitarian limits of this ultradilute catalysis. The low MP concentrations decrease throughout catalysis with S oxidation (kII) and catalyst inactivation (ki) competing for the active catalyst. The percentage of substrate converted (%Cvn) can be increased by discovering methods to increase kII/ki. Here we show that NaClO extends catalyst lifetime to increase the Met turnover number (TON) threefold compared with H2O2, highlighting the importance of oxidant choice as a design tool in TAML systems. Met oxidation studies (pH 7, D2O, 0.01 M phosphate, 25 °C) monitored by 1H NMR spectroscopy show benign acetic acid as the only significant product. Analysis of TAML/NaClO treated Met solutions employing successive identical catalyst doses revealed that the processes can be modeled by the recently published relationship between the initial and final [S] (S0 and S∞, respectively), the initial [catalyst] (FeTot) and kII/ki. Consequently, this study establishes that S is proportional to S0 and that the %Cvn is conserved across all catalyst doses in multicatalyst-dose processes because the rate of the kII process depends on [S] while that of the ki process does not. A general tool for determining the FeTot required to effect a desired %Cvn is presented. Examination of the dependence of TON on kII/ki and FeTot at a fixed S0 indicates that for any TAML process employing FeTot < 1 10-6 M, small catalyst doses are not more efficient than one large dose.T.J.C thanks the Heinz Endowments for funding. NMR instrumentation at CMU was partially supported by NSF (CHE-0130903 and CHE-1039870)
Development of ERAU VOLTRON Hybrid-Electric Powerplant
The energy density of today’s batteries is not high enough for electric powered aircraft to achieve an operationally viable range plus FAA stipulated reserve flight times. Hybrid-electric power generation systems may be able to bridge the gap, providing a way for these aircraft to fly distances not possible with batteries alone. There is a recognition that gasoline-electric hybrid systems can deliver specific energy and specific power that are higher than any currently available battery system.
Embry-Riddle Aeronautical University’s (ERAU’s) Eagle Flight Research Center (EFRC) is building a 70+ kW hybrid-electric power generation system using a rotary engine and Permanent Magnet Synchronous Machine (PMSM) & Inverter. The rotary engine will be directly coupled to the PMSM which will generate electrical energy to power multi-rotor eVTOL vehicles. These results will be achieved by utilizing advanced control systems implemented on a National Instruments Compact RIO.
Past research conducted at the EFRC demonstrated the ability to design and operate a hybrid-electric powerplant. The VOLTRON project will attempt to create a system with an even higher specific energy but with the compact size and high power characteristics of a rotary engine and eventually alternative fuel flexibility
Differences in need for antihypertensive drugs among those aware and unaware of their hypertensive status: a cross sectional survey
BACKGROUND: Lack of antihypertensive use among hypertensive individuals is a major public health problem. It remains unclear as to how much of this lack of treatment is because of failure to diagnose hypertension or failure to initiate drug treatment for those with a diagnosis of hypertension. The primary aim of this study was to determine the proportion of those untreated individuals who would be recommended to start drug therapy for control of blood pressure among those aware or unaware of their diagnosis of hypertension. METHODS: The Canadian Heart Health Surveys (1986 – 1992), a national, cross-sectional descriptive survey (n = 23 129), was used to determine the proportion of individuals who were untreated, yet satisfied the 2004 Canadian hypertension guidelines for initiating drug therapy. Patients were divided into subgroups of those aware and unaware of having a diagnosis of hypertension according to self reported awareness from the survey. RESULTS: Of those with untreated hypertension (= 140/90 mmHg), only 37% were aware of their diagnosis. 74% of untreated individuals aware of their diagnosis of hypertension would require drug therapy, compared to 57% of those who were unaware. Of those >65 years of age, 52% of aware individuals needed drug therapy whereas only 34% of unaware elderly would need drug treatment. CONCLUSION: In both unaware and aware subgroups, the majority of patients with untreated hypertension would benefit from antihypertensive drug therapy according to the 2004 Canadian Hypertension recommendations. The proportion of untreated patients that still need drug therapy was higher among those who were aware compared to those who were unaware. This finding suggests that the major gap in hypertension control may be in initiating drug therapy rather than in diagnosing hypertension. Further studies are needed to confirm these results to ultimately help strategize public health efforts in controlling hypertension
- …