1,037 research outputs found

    A Road to Injustice Paved with Good Intentions: Maggie\u27s Misguided Crackdown on Drowsy Driving

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    Sleep-deprived drivers pose a serious threat to the public, killing and injuring tens of thousands of Americans each year. Nevertheless, this problem was largely ignored until the summer of 2003, when the New Jersey legislature made national headlines by passing Maggie\u27s Law. Maggie\u27s Law is a unique revision to New Jersey\u27s vehicular homicide statute that permits unprecedented criminal penalties for drowsy drivers who are involved in deadly automobile accidents. The law\u27s passage has had an effect far outside New Jersey\u27s borders, leading many other states and the federal government to consider similar legislation. This Note details the history and language of Maggie\u27s Law, and acknowledges that drowsy driving is a major safety concern that policymakers have failed to address adequately. This Note argues, however, that the language of Maggie\u27s Law will significantly reduce its effectiveness. In particular, this Note addresses problems concerning the law\u27s under- and over-inclusiveness, ambiguity, and focus. In addition, this Note highlights the difficulty of enforcing the law effectively. Recognizing that steps must be taken to address the danger created by drowsy drivers, this Note proposes alternative language to the current version of Maggie\u27s Law. It contends that a totality of the circumstances approach rather than the twenty-four-hour limit in Maggie\u27s Law provides better structures for criminal sanctions against drowsy drivers. This Note also emphasizes the need to couple non-judicial strategies with tougher criminal penalties in order to more effectively reduce drowsy driving accidents

    Synchronizing Cardiac Cycle Phase with Foot Strike to Optimize Cardiac Performance in Patients with Chronic Systolic Heart Failure and Cardiac Resynchronization Therapy (CRT)

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    Despite advances in medical and Cardiac Resynchronization Therapy (CRT), patients with chronic systolic heart failure (HF) have persistent symptoms including dyspnea on exertion and exercise intolerance. Novel strategies to improve exercise performance in these patients, such as optimizing cardio-locomotor coupling, could be particularly beneficial to improve functional capacity. For example, runners display a lower heart rate and higher oxygen pulse, suggestive of a higher stroke volume (SV), when foot strike occurs in diastole. Whether patients with HF undergoing CRT can similarly increase SV is unknown. PURPOSE: To compare the effects of diastolic versus systolic foot strike timing on exercise hemodynamics in patients with HF and CRT. METHODS: Ten patients (Age: 58 ± 17 years, 40% Female) with HF and previously implanted CRT pacemakers completed repeated 5-minute bouts of walking on a treadmill at a fixed but individualized speed (range: 1.5-3mph). Participants were randomized to walking to an auditory tone to synchronize their foot strike to either the systolic (ECG R-wave; 0 or 100%±15% or R-R interval) or diastolic phase (45±15% of the R-R interval) of their cardiac cycle. Participants were included if ≥50% of their steps were valid (i.e. in time). Patients wore a chest strap with an attached ECG sensor and accelerometer (CounterpaceR). Foot strike timing and associated valid step counts were assessed via CounterpaceR or post-hoc analysis of foot strike waveforms. Cardiopulmonary parameters were measured breath by breath via indirect calorimetry and cardiac output was measured via acetylene rebreathing, with SV calculated as the quotient of cardiac output and heart rate. RESULTS: There was no difference in oxygen uptake between conditions (1.02 ± 0.44 vs. 1.04 ± 0.44 L/min, P=0.298). When compared to systolic walking, stepping in diastole was associated with higher SV (Diastolic: 80 ± 28 vs. Systolic: 74 ± 26 ml, P=0.003) and cardiac output (8.3 ± 3.5 vs. 7.9 ± 3.4 L/min, P=0.004); heart rate (paced) was not different between conditions (101 ± 15 vs. 103 ± 14 bpm, P=0.300). Mean arterial pressure was significantly lower during diastolic walking (85 ± 12 vs. 98 ± 20 mmHg, P=0.007). CONCLUSION: In patients with HF and previous CRT, synchronizing foot strike with diastole during walking increased SV and cardiac output and reduced arterial pressure. Our findings indicate that in such paced hearts, diastolic stepping increases oxygen delivery and decreases afterload, which may facilitate increased exercise capacity. Therefore, if added to pacemakers, this cardio-locomotor coupling technology may maximize CRT efficiency and increase exercise participation and quality of life in patients with HF

    Omnidirectional Transfer for Quasilinear Lifelong Learning

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    In biological learning, data are used to improve performance not only on the current task, but also on previously encountered and as yet unencountered tasks. In contrast, classical machine learning starts from a blank slate, or tabula rasa, using data only for the single task at hand. While typical transfer learning algorithms can improve performance on future tasks, their performance on prior tasks degrades upon learning new tasks (called catastrophic forgetting). Many recent approaches for continual or lifelong learning have attempted to maintain performance given new tasks. But striving to avoid forgetting sets the goal unnecessarily low: the goal of lifelong learning, whether biological or artificial, should be to improve performance on all tasks (including past and future) with any new data. We propose omnidirectional transfer learning algorithms, which includes two special cases of interest: decision forests and deep networks. Our key insight is the development of the omni-voter layer, which ensembles representations learned independently on all tasks to jointly decide how to proceed on any given new data point, thereby improving performance on both past and future tasks. Our algorithms demonstrate omnidirectional transfer in a variety of simulated and real data scenarios, including tabular data, image data, spoken data, and adversarial tasks. Moreover, they do so with quasilinear space and time complexity

    Three red suns in the sky: A transiting, terrestrial planet in a triple M-dwarf system at 6.9 pc

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    We present the discovery from Transiting Exoplanet Survey Satellite (TESS) data of LTT 1445Ab. At a distance of 6.9 pc, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use MEarth data and results from the Science Processing Operations Center data validation report to determine that the planet transits the primary star in the system. The planet has a radius of 1.380.12+0.13{1.38}_{-0.12}^{+0.13} R{R}_{\oplus }, an orbital period of 5.358820.00031+0.00030{5.35882}_{-0.00031}^{+0.00030} days, and an equilibrium temperature of 43327+28{433}_{-27}^{+28} K. With radial velocities from the High Accuracy Radial Velocity Planet Searcher, we place a 3σ upper mass limit of 8.4 M{M}_{\oplus } on the planet. LTT 1445Ab provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. We also present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicate a moderate amount of variability, in agreement with that observed in the TESS light-curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system hints that the entire system may be co-planar, implying that the system may have formed from the early fragmentation of an individual protostellar core.Accepted manuscrip

    Spleen tyrosine kinase-mediated autophagy is required for epithelial-mesenchymal plasticity and metastasis in breast cancer

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    The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGF-β to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGF-β-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy related 7 (ATG7) or pharmacological inhibition of SYK activity with fostamatib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, the current study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells

    Skeletal Light-Scattering Accelerates Bleaching Response in Reef-Building Corals

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    Background At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as ‘microscopic’ reduced-scattering coefficient, μ′S,m), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Results Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-μ′S,m corals bleach at higher rate and severity than high-μ′S,m corals and the Symbiodinium associated with low-μ′S,m corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-μ′S,m corals. Conclusions While symbionts associated with low-μ′S,m corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor of light-dependent bleaching among the corals assessed here, this work establishes μ′S,m as one of the key determinants of differential bleaching response
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