434 research outputs found
Energy from Waste: Preparing Today for Tomorrow's Energy Needs
No full textThis paper addresses the question of why Hooker Chemical Company, a subsidiary of Occidental Petroleum Corporation, would turn to solid waste as an energy alternative. It presents the considerations in the company's decision to construct a $70 million Energy-From-Waste plant, already well underway at Hooker's Niagara Falls, New York, plant site, with similar plants under study for other Hooker locations. It attempts to illustrate why both Occidental and Hooker are committed to the concept that resource recovery is one of today's practical means of preparing for future energy management.
The paper explains that the Energy-From-Waste alternative was selected for Niagara Falls not as an experiment, but as a viable future energy source based on circumstances relevant to this particular plant site. Operational, financial, technical and corporate considerations are presented in light of Hooker's competitive position in the world chemicals market.
The author does not attempt to establish that Energy-From-Waste is the best of all possible energy alternatives, nor does he ignore some very real problems, including the lack of profitability seen in other similar ventures. Energy-From-Waste, however, is a practical and proven technology that the company feels will grow more attractive and cost-efficient over the years, while traditional fuel costs remain unpredictable. Hooker believes that to do well in the future, industry must plan ahead. The time for active development of energy alternatives is now
The evolving reputation of Richard Hooker : an examination of responses to the Ecclesiastical Polity, 1640-1714.
Get PDFSIGLEAvailable from British Library Document Supply Centre-DSC:DXN033104 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Psychomotor Impairment Detection via Finger Interactions with a Computer Keyboard During Natural Typing
Get PDFModern digital devices and appliances are capable of monitoring the timing of button presses, or finger interactions in general, with a sub-millisecond accuracy. However, the massive amount of high resolution temporal information that these devices could collect is currently being discarded. Multiple studies have shown that the act of pressing a button triggers well defined brain areas which are known to be affected by motor-compromised conditions. In this study, we demonstrate that the daily interaction with a computer keyboard can be employed as means to observe and potentially quantify psychomotor impairment. We induced a psychomotor impairment via a sleep inertia paradigm in 14 healthy subjects, which is detected by our classifier with an Area Under the ROC Curve (AUC) of 0.93/0.91. The detection relies on novel features derived from key-hold times acquired on standard computer keyboards during an uncontrolled typing task. These features correlate with the progression to psychomotor impairment (p < 0.001) regardless of the content and language of the text typed, and perform consistently with different keyboards. The ability to acquire longitudinal measurements of subtle motor changes from a digital device without altering its functionality may allow for early screening and follow-up of motor-compromised neurodegenerative conditions, psychological disorders or intoxication at a negligible cost in the general population.Comunidad de Madri
Therapeutic potential of tryptamine psychedelics for psychiatric disorders
Get PDFThe modern psychiatric crisis has become a global epidemic as the prevalence of psychiatric disorders continues to rise. These numbers have only been exacerbated by the COVID-19 pandemic, and the long-term psychological effects resulting from the social isolation and fear of the disease have yet to be seen. Those already suffering from psychiatric disorders have limited options for treatment, as current therapeutic methods for mood, anxiety, and substance use disorders demonstrate high failure rates with many individuals suffering from treatment resistance. Individuals that do respond to modern therapies typically require treatment for several weeks or months, occasionally even years, before experiencing any reductions in their symptoms.
Tryptamine psychedelics have been used for millennia by indigenous cultures through highly ritualized religious ceremonies to purge individuals of disease and offer spiritual guidance, however their application within modern medicine did not begin until Albert Hofmann’s discovery of LSD in 1938. The next several decades saw an explosion in clinical studies involving tryptamine psychedelics showcasing their ability to demonstrate immediate treatment after single doses in individuals suffering from diseases such as depression and PTSD, however research and clinical practices came to a halt after the passing of the Controlled Substances Act of 1970. As renewed interest in psychedelic medicine continues to grow, this review details the therapeutic potential of tryptamine psychedelics while exploring their current status within clinical trials
PET/MRI in the presence of metal implants: Completion of the attenuation map from PET emission data
Get PDFWe present a novel technique for accurate whole-body attenuation correction in the presence of metallic endoprosthesis, on integrated non-time-of-flight (non-TOF) PET/MRI scanners. The proposed implant PET-based attenuationmap completion (IPAC) method performs a joint reconstruction of radioactivity and attenuation from the emission data to determine the position, shape, and linear attenuation coefficient (LAC) of metallic implants. Methods: The initial estimate of the attenuation map was obtained using the MR Dixon method currently available on the Siemens Biograph mMR scanner. The attenuation coefficients in the area of the MR image subjected to metal susceptibility artifacts are then reconstructed fromthe PET emission data using the IPAC algorithm. The method was tested on 11 subjects presenting 13 different metallic implants, who underwent CT and PET/MR scans. Relative mean LACs and Dice similarity coefficients were calculated to determine the accuracy of the reconstructed attenuation values and the shape of the metal implant, respectively. The reconstructed PET images were compared with those obtained using the reference CT-based approach and the Dixon-based method. Absolute relative change (aRC) images were generated in each case, and voxel-based analyses were performed. Results: The error in implant LAC estimation, using the proposed IPAC algorithm, was 15.7%± 7.8%, which was significantly smaller than the Dixon- (100%) and CT-(39%) derived values. A mean Dice similarity coefficient of 73% ± 9% was obtained when comparing the IPAC- with the CT-derived implant shape. The voxel-based analysis of the reconstructed PET images revealed quantification errors (aRC) of 13.2% ± 22.1% for the IPACwith respect to CT-corrected images. The Dixon-based method performed substantially worse, with a mean aRC of 23.1% ± 38.4%. Conclusion: We have presented a non-TOF emission-based approach for estimating the attenuation map in the presence of metallic implants, to be used for whole-body attenuation correction in integrated PET/MR scanners. The Graphics Processing Unit implementation of the algorithm will be included in the open-source reconstruction toolbox Occiput.io
Classics in neuroimaging: Imaging the dopaminergic pathway with PET.
No full textThe success of positron emission tomography (PET) for observing molecular processes underlying brain function and disease is underpinned by radiotracer chemistry. From the earliest applications of PET to measure dopamine synthesis capacity and the abundance of neuroreceptors and transporters, to the more recent topic of dynamic neurochemical imaging, interrogation of brain dopamine in conditions such as neurodegenerative diseases, schizophrenia, mood disorders, and addictions has been a driving force that challenges the ingenuity of radiopharmaceutical scientists. In fact, the pursuit of new ligands and reaction methods to address longstanding challenges has often been pioneered in the context of dopamine imaging. From this viewpoint, we highlight the unique history of imaging the dopaminergic pathway with PET, and present our interpretation of how this worldwide effort shaped and continues to drive the field of molecular imaging
Images as proximity sensors : the incidence of conspecific foraging in Antarctic fur seals
Get PDFBackground: Although there have been recent advances in the development of animal-attached ‘proximity’ tags to remotely record the interactions of multiple individuals, the efficacy of these devices depends on the instrumentation of sufficient animals that subsequently have spatial interactions. Among densely colonial mammals such as fur seals, this remains logistically difficult, and interactions between animals during foraging have not previously been recorded. Results: We collected data on conspecific interactions during diving at sea using still image and video cameras deployed on 23 Antarctic fur seals. Animals carried cameras for a total of 152 days, collecting 38,098 images and 369 movies (total time 7.35 h). Other fur seals were detected in 74% of deployments, with a maximum of five seals seen at one time (n = 122 images, 28 videos). No predators other than conspecifics were observed. Detection was primarily limited by light conditions, since conspecifics were usually further from each other than the 1-m range illuminated by camera flash under low light levels. Other seals were recorded at a range of depths (average 27 ± 14.3 m, max 66 m). In terms of bouts of dives, still images of other seals were recorded in 5 single dives (of 330) and 28 bouts of dives <2 min apart (of 187). Linear mixed models suggested a relationship between conspecific observations per dive and the number of krill images recorded per dive. Using light conditions as a proxy for detectability, other seals were more likely to be observed at the bottom of dives than during descent or ascent. Seals were also more likely to be closer to each other and oriented perpendicular to each other at the bottom of dives, and in the same direction as each other during ascent. Conclusions: These results are contrary to animal-attached camera observations of penguin foraging, suggesting differing group-foraging tactics for these marine predators. Group foraging could have consequences for models linking predator behaviour to prey field densities since this relationship may be affected by the presence of multiple predators at the same patch.Peer reviewe
Two new combinations in Erythranthe section Simiolus (Phrymaceae) for the
No full textTwo Chilean members of Mimulus, M. minimus and M. depressus var. ciminum, are transfered to Erythranthe as E. minima and E. depressa var. ciminum respectively. Key words: Mimulus, Scrophulariaceae, nomenclature, Mexico History of the specific taxon Two different species of Mimulus have been published with the same name. One, M. nanus Philippi (1860: 45), is a diminutive, yellow-flowered annual collected by its author in Chile. It is known only from his type collection obtained in the lower Andes of the Atacama Desert (Muñoz Pizzaro 1960, von Bohlen 1995). Later it was reduced in rank to varietal status as M. depressus Philippi (1860: 45) var. nanus (Philippi) Reiche (1911: 62). The specific epithet is not legitimate although the varietal name is acceptable under ICN Article 11.2 (McNeill et al. 2012). The legitimate earlier Mimulus nanus Hooker & Arnott (1839: 379) is a small annual from western North America with rich pink or strong violet-pink corollas. It has lately been transferred to the genus Diplacus as D. nanus (Hooker & Arnott) G.L. Nesom (Barker et al. 2012: 29). While reviewing Mimulus in Chile for a monograph, Christian von Bohlen (1995) concluded that M. nanus of Philippi was distinct from M. depressus, and proposed M. minimus C. Bohlen (1995: 13) as a new name. Hitherto, Reiche's varietal combination had been the accepted name (Marticorena & Quezada 1985: 70). This binomial, in turn, also has a later illegitimate homonym, M. minimus E. Pérez-Calix & Zamudio (2011: 32), given to a recentl
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