301 research outputs found
Self-knowledge and the limits of transparency
No full textA number of recent accounts of our first-person knowledge of our attitudes give a central role to transparency - our capacity to answer the question of whether we have an attitude by answering the question of whether to have it. In this paper I raise a problem for such accounts, by showing that there are clear cases of first-person knowledge of attitudes which are not transparent
Sympathetic discharge and vascular resistance after bed rest
No full text Shoemaker, J. Kevin, Cynthia S. Hogeman, Urs A. Leuenberger, Michael D. Herr, Kristen Gray, David H. Silber, and Lawrence I. Sinoway. Sympathetic discharge and vascular resistance after bed rest. J. Appl. Physiol. 84(2): 612–617, 1998.—The effect of −6° head-down-tilt bed rest (HDBR) for 14 days on supine sympathetic discharge and cardiovascular hemodynamics at rest was assessed. Mean arterial pressure, heart rate ( n = 25), muscle sympathetic nerve activity (MSNA; n = 16) burst frequency, and forearm blood flow ( n = 14) were measured, and forearm vascular resistance (FVR) was calculated. Stroke distance, our index of stroke volume, was derived from measurements of aortic mean blood velocity (Doppler) and R-R interval ( n = 7). With these data, an index of total peripheral resistance was determined. Heart rate at rest was greater in the post (71 ± 2 beats/min)- compared with the pre-HDBR test (66 ± 2 beats/min; P < 0.003), but mean arterial pressure was unchanged. Aortic stroke distance during post-HDBR (15.5 ± 1.1 cm/beat) was reduced from pre-HDBR levels (20.0 ± 1.5 cm/beat) ( P < 0.03). Also, MSNA burst frequency was reduced in the post (16.7 ± 2.8 beats/min)- compared with the pre (25.2 ± 2.6 beats/min)-HDBR condition ( P < 0.01). Bed rest did not alter forearm blood flow, FVR, or total peripheral resistance. Thus reductions in MSNA with HDBR were not associated with a decrease in FVR. </jats:p
Confidence from uncertainty - A multi-target drug screening method from robust control theory
No full textAbstract
Background
Robustness is a recognized feature of biological systems that evolved as a defence to environmental variability. Complex diseases such as diabetes, cancer, bacterial and viral infections, exploit the same mechanisms that allow for robust behaviour in healthy conditions to ensure their own continuance. Single drug therapies, while generally potent regulators of their specific protein/gene targets, often fail to counter the robustness of the disease in question. Multi-drug therapies offer a powerful means to restore disrupted biological networks, by targeting the subsystem of interest while preventing the diseased network from reconciling through available, redundant mechanisms. Modelling techniques are needed to manage the high number of combinatorial possibilities arising in multi-drug therapeutic design, and identify synergistic targets that are robust to system uncertainty.
Results
We present the application of a method from robust control theory, Structured Singular Value or μ- analysis, to identify highly effective multi-drug therapies by using robustness in the face of uncertainty as a new means of target discrimination. We illustrate the method by means of a case study of a negative feedback network motif subject to parametric uncertainty.
Conclusions
The paper contributes to the development of effective methods for drug screening in the context of network modelling affected by parametric uncertainty. The results have wide applicability for the analysis of different sources of uncertainty like noise experienced in the data, neglected dynamics, or intrinsic biological variability.
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Pleosporales
No full textOne hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
Augmented sympathetic tone alters muscle metabolism with exercise: lack of evidence for functional sympatholysis
No full text Shoemaker, J. Kevin, Prasant Pandey, Michael D. Herr, David H. Silber, Qing X. Yang, Michael B. Smith, Kristen Gray, and Lawrence I. Sinoway. Augmented sympathetic tone alters muscle metabolism with exercise: lack of evidence for functional sympatholysis. J. Appl. Physiol. 82(6): 1932–1938, 1997.—It is unclear whether sympathetic tone opposes dilator influences in exercising skeletal muscle. We examined high levels of sympathetic tone, evoked by lower body negative pressure (LBNP, −60 mmHg) on intramuscular pH and phosphocreatine (PCr) levels (31P-nuclear magnetic resonance spectroscopy) during graded rhythmic handgrip (30 contractions/min; ∼17, 34, 52 and 69% maximal voluntary contraction). Exercise was performed with LBNP and without LBNP (Control). At the end of exercise, LBNP caused lower levels of muscle pH (6.59 ± 0.09) compared with Control (6.78 ± 0.05; P < 0.05). PCr recovery, an index of mitochondrial respiration, was less during the recovery phase of the LBNP trial. Exercise mean arterial pressure was not altered by LBNP. The protocols were repeated with measurements of forearm blood flow velocity and deep venous samples (active forearm) of hemoglobin (Hb) saturation, pH, and lactate. With LBNP, mean blood velocity was reduced at rest, during exercise, and during recovery compared with Control ( P < 0.05). Also, venous Hb saturation and pH levels during exercise and recovery were lower with LBNP and lactate was higher compared with Control ( P < 0.05). We conclude that LBNP enhanced sympathetic tone and reduced oxygen transport. At high workloads, there was a greater reliance on nonoxidative metabolism. In other words, sympatholysis did not occur. </jats:p
Murray City Fire Department, 2001
No full textGroup photo of the Murray Fire Department crew, on and around one of the Fire Department\u27s large trucks. Pictured: Jon Jastram, Matt Boulden, Marilyn Madsen, Mike Estrada, Andy Walkingshaw, Jesse Valenzuela, Phil Roberts, Chief Gil Rodriguez, Paul Adams, Blair Camp, Mike Dykman, Jack Snow, Randy Willden, Laura Lloyd, Glenae Turley, Chad Pascua, Kendall Baird, Jeff Ellis, Art Cracraft, Kent Swensen, Paul Krueger, Jerry Bilanzich, Shane Stratton, Chris Pendleton, Steve Ellefsen, Bob Smith, Pat Killion, Joe Beard, Jeff Thornley, Paul Mapes, Kevin Potter, Joe Treadwell, Kelly Farrington, Amy Fisher, Russ Jensen, Rex Stembridge, Dave Florin, Paul Adams, Jon Harris, Brad Freeman, Russ Blank, Kevin Divine, Scott White, Jon Grangroth, Jeremy Shoemaker, Statt Berger, Jennifer Litster, Kevin Fellion, Jeff Griffith, Dave Shaw, Jason Jone
Neutrino Self-Interactions: A White Paper
No full textNeutrinos are the Standard Model (SM) particles which we understand the
least, often due to how weakly they interact with the other SM particles.
Beyond this, very little is known about interactions among the neutrinos, i.e.,
their self-interactions. The SM predicts neutrino self-interactions at a level
beyond any current experimental capabilities, leaving open the possibility for
beyond-the-SM interactions across many energy scales. In this white paper, we
review the current knowledge of neutrino self-interactions from a vast array of
probes, from cosmology, to astrophysics, to the laboratory. We also discuss
theoretical motivations for such self-interactions, including neutrino masses
and possible connections to dark matter. Looking forward, we discuss the
capabilities of searches in the next generation and beyond, highlighting the
possibility of future discovery of this beyond-the-SM physics.Comment: Editors: Nikita Blinov, Mauricio Bustamante, Kevin J. Kelly, Yue
Zhang. 29 pages, 16 figures, plus references. Contribution to Snowmass 202
Tree coverage assessment using object-based image analysis
No full textThe need to conserve natural and ecological systems is a topical issue in the world today. Assessment of the state of ecological systems is often carried out using remote sensing data collection techniques and analysis. Nonetheless, the usage of software in remote sensing and classification is set with many difficulties. The purpose of this study was to suggest an easy to use solution to classify high-resolution satellite imagery quickly and efficiently. Moreover, the objective of the research was to assess tree coverage in Lubbock, Texas, an ecosystem where key relationships facilitating ecological diversity are dependent upon the preservation and promotion of biodiversity. In this study, the object-based image analysis (OBIA) was used in the classification of images from satellite data. The use of OBIA data produced significant improvements in the assessment of tree canopies and land use in Lubbock. OBIA is user friendly and easy to use even with limited or no previous experience. The classification depicts different land use patterns in the study area. The urban zone of Lubbock has a dense network of tree canopies. Canopy coverage however decreases towards the transition zone and rural part of Lubbock. The transition quadrangle is composed of low vegetation, trees, and bare ground. Tree canopy coverage is minimal in the rural part of the study area. This part is dominated by agriculture. Agricultural activities distort the natural landscape and result in habitat loss for raptors. A decline in birds of prey is likely to increase pest infestation and increased usage of synthetic chemicals in Lubbock
Geolocators as Tools for Inferring Waterfowl Movements and Breeding Phenology in the Pacific Flyway
No full textUnderstanding the geographical extent and timing of wildlife movements enables resource managers to meet the habitat needs of target species efficiently and effectively. Historically, information about waterfowl movements has been derived from mark-recovery data in which birds are trapped and marked with metal leg bands that are subsequently reported via hunter harvest. Such banding efforts typically yield two data points per individual (banding location and harvest location), and are poorly suited for estimating migration paths, stopover sites and timing of movements. Here, we use light-level geolocators �" which enable researchers to track individual locations on the basis of estimated daily twilight times �" to build a more complete understanding of the geography and timing of migratory movements for canvasbacks (Aythya valisineria) in the Pacific Flyway. During 2015-2017, 151 geolocators were placed on canvasbacks using two alternative attachment methods (leg-band vs. nasal-saddle mounts) during spring migration (February - March) near Reno, NV. Five of these geolocators (three males and two female) were successfully recovered from hunters. Four of the five tagged canvasbacks (2 males and 2 female) migrated to breeding sites in southern Canada (Alberta and Saskatchewan, via stopover sites in Utah and Montana), while one male migrated to a breeding site in Alaska. After initial capture in early spring, two canvasbacks (one Canada-breeding male and the Alaska-breeding male) remained near the capture site in Western Nevada or California for over a month (40 and 77 days, respectively), until resuming migration in late March or April. During spring migration, canvasbacks made an average of 3 stops, with an average stopover duration of 18±4 days. Three canvasbacks made a distinct molt migration after breeding. For fall migration, the canvasbacks made an average of 2.3±0.7 stops, lasting an average of 7.1±1.3 days, on their way to wintering sites in California’s Central Valley and San Francisco Bay area. Recovery of nasal saddle-mounted geolocators was significantly lower than leg band-mounted devices. This study demonstrates the value of geolocators for assessing year-round habitat use for waterfowl populations. This information complements standard band-recovery approaches, and enables waterfowl managers to ensure that the spatial and temporal distributions of individuals are identified so that habitat conservation efforts reflect the full annual habitat use cycle.Avian ecologists typically undertake costly and time intensive nest surveys to estimate key parameters such as nesting propensity, clutch size, nest success and hatching success. However, nesting surveys can be prohibitively difficult and/or costly in many cases. Less time consuming and invasive tools to supplement reproductive parameter estimates are needed. However, use of geolocators to infer reproductive parameters has not been rigorously validated. We attached light level geolocators to wood ducks (Aix sponsa) in northern Nevada, in a population that also was intensively monitored via artificial nest boxes. To designate each day as either nesting or non-nesting from geolocator data, we used a Bayesian mixture model, enabling estimation of life-history traits such as nesting propensity, annual nesting attempts, incubation duration and nest success. We also attempted to distinguish among nest prospecting, laying, incubation, and brood-rearing behaviors using an unsupervised time-series clustering algorithm, and to further estimate clutch size and nest fate. Using artificial nest box monitoring as validation data, we confirmed the accuracy of geolocator-derived estimates of the number and timing of nesting attempts and nest success. We were unable to confirm the validity of geolocator-derived estimates of clutch size (number of laying days). Using geolocator data, we estimated a nesting propensity of 0.92, with 87% apparent nest success for surviving females (100% success in natural cavities vs. 73% success in artificial nest boxes). Our clustering assignments showed some ability to discriminate among nesting behaviors, but were unable to effectively predict clutch size or nest fate. Our study is the first to rigorously validate the use of incubation length for predicting success of individual nests. We contend that widespread deployment of geolocators on waterfowl and other birds would enable estimates of reproductive parameters for species and populations not amenable to standard nesting surveys, after controlling for nesting season adult female survival
Forebrain Neurocircuitry Associated With Human Reflex Cardiovascular Control
No full textPhysiological homeostasis depends upon adequate integration and responsiveness of sensory information with the autonomic nervous system to affect rapid and effective adjustments in end organ control. Dysregulation of the autonomic nervous system leads to cardiovascular disability with consequences as severe as sudden death. The neural pathways involved in reflexive autonomic control are dependent upon brainstem nuclei but these receive modulatory inputs from higher centres in the midbrain and cortex. The growth of neuroimaging technologies have allowed closer study of the cortical circuitry related to autonomic cardiovascular adjustments to many stressors in awake humans and have exposed many forebrain sites that associate strongly with cardiovascular arousal during stress including the medial prefrontal cortex, insula cortex, anterior cingulate, amygdala and hippocampus. Using a comparative approach, this review will consider the cortical autonomic circuitry in rodents and primates with a major emphasis on more recent neuroimaging studies in awake humans. A challenge with neuroimaging studies is their interpretation in view of multiple sensory, perceptual, emotive and/or reflexive nature of autonomic responses. This review will focus on those responses related to non-volitional baroreflex control of blood pressure and also on the coordinated responses to non-fatiguing, non-painful volitional exercise with particular emphasis on the medial prefrontal cortex and the insula cortex
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