46 results on '"Peter Novak"'
Search Results
2. Nanotechnology-driven Microemulsion Based Intranasal Delivery to Neurotechnology-driven Neuralink: Strategies to Improve Management of Neurodegenerative Disorders.
- Author
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Pragya, Bisht, Shradha, and Parashar, Poonam
- Abstract
Neurodegenerative disorder refers to malfunctioning of neurons their degradation leading to death of neurons. Among various neurodegenerative disorders APHD (Alzheimer's, Parkinson's, and Huntington's Disease) are particularly concerning due to their progressive and debilitating nature. The therapeutic agent used for treatment and management of APHD often show unsatisfactory clinical outcome owing to poor solubility and limited permeability across blood brain barrier (BBB). The nose-to brain delivery can overcome this BBB challenge as it can transport drug directly to brain though olfactory pathways bypassing BBB. Additionally, the nanotechnology has emerged as a cutting-edge methodology to address this issue and specifically mucoadhesive micro/nanoemulsion can improve the overall performance of the drug when administered intranasally. Beyond the therapy neurotechnology has emerged as are revolutionary AI-driven BCI (Brain computer interface) aimed to restore independence in patients with function loss due to neuron degeneration/death. A promising BCI Neuralink has been recently explored for clinical trials and results revealed that a quadriplegia bearing person with implanted Neuralink chip was able to perform few normal functions of daily routine such as playing online games, text messaging, reading, and learning foreign languages online through accessing the particular websites. This review will discuss the fundamental concepts of neurodegeneration, application of micro/nanoemulsion through intranasal route and integration of neurotechnology for the management and treatment of APHD. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Head-down tilt reduces the heart rate in postural tachycardia syndrome in acute setting: a pilot study.
- Author
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Novak, Peter
- Subjects
POSTURAL orthostatic tachycardia syndrome ,HEART beat ,POST-acute COVID-19 syndrome ,ORTHOSTATIC intolerance ,CEREBRAL circulation ,BLOOD volume - Abstract
Background: Reduced preload and thoracic blood volume accompany postural tachycardia syndrome (POTS). Head-down tilt (HDT) increases both preload and intrathoracic blood volume. The objective of this study was to assess the safety and efficacy of HDT in POTS in acute settings. Methods: This retrospective study evaluated POTS patients. Analyzed data included heart rate, blood pressure, cerebral blood flow velocity (CBFv) in the middle cerebral artery, and capnography. The baseline supine hemodynamic data were compared with the data obtained at the second minute of the −10° HDT. A linear mixed-effects model was used to assess the effect of HDT on hemodynamic variables. Results: The HDT was explored in seven POTS patients and an additional seven POTS patients without HDT served as controls. In the HDT arm, four POTS patients had overlapping diagnoses of myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) and one patient had comorbidity of post-acute sequelae of SARS-CoV-2 infection (PASC). HDT lowered heart rate by 10% and increased end-tidal CO
2 by 8%. There was no change in other cardiovascular variables. Conclusions: In the acute setting, HDT is safe. HDT reduces the heart rate presumably by modulating baroreflex by enhancing preload and stroke volume, which in turn increases thoracic blood volume with a net effect of parasympathetic cardiovagal activation and/or sympathetic withdrawal. This pilot study provides a foundation to proceed with longitudinal studies exploring the long-term effect of repetitive HDT in conditions associated with preload failure such as POTS, ME/CSF, and PASC. [ABSTRACT FROM AUTHOR]- Published
- 2024
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4. Clinical Trial-Ready Patient Cohorts for Multiple System Atrophy: Coupling Biospecimen and iPSC Banking to Longitudinal Deep-Phenotyping.
- Author
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Ndayisaba, Alain, Pitaro, Ariana T., Willett, Andrew S., Jones, Kristie A., de Gusmao, Claudio Melo, Olsen, Abby L., Kim, Jisoo, Rissanen, Eero, Woods, Jared K., Srinivasan, Sharan R., Nagy, Anna, Nagy, Amanda, Mesidor, Merlyne, Cicero, Steven, Patel, Viharkumar, Oakley, Derek H., Tuncali, Idil, Taglieri-Noble, Katherine, Clark, Emily C., and Paulson, Jordan
- Subjects
MULTIPLE system atrophy ,INDUCED pluripotent stem cells ,PARKINSON'S disease ,SPINOCEREBELLAR ataxia - Abstract
Multiple system atrophy (MSA) is a fatal neurodegenerative disease of unknown etiology characterized by widespread aggregation of the protein alpha-synuclein in neurons and glia. Its orphan status, biological relationship to Parkinson's disease (PD), and rapid progression have sparked interest in drug development. One significant obstacle to therapeutics is disease heterogeneity. Here, we share our process of developing a clinical trial-ready cohort of MSA patients (69 patients in 2 years) within an outpatient clinical setting, and recruiting 20 of these patients into a longitudinal "n-of-few" clinical trial paradigm. First, we deeply phenotype our patients with clinical scales (UMSARS, BARS, MoCA, NMSS, and UPSIT) and tests designed to establish early differential diagnosis (including volumetric MRI, FDG-PET, MIBG scan, polysomnography, genetic testing, autonomic function tests, skin biopsy) or disease activity (PBR06-TSPO). Second, we longitudinally collect biospecimens (blood, CSF, stool) and clinical, biometric, and imaging data to generate antecedent disease-progression scores. Third, in our Mass General Brigham SCiN study (stem cells in neurodegeneration), we generate induced pluripotent stem cell (iPSC) models from our patients, matched to biospecimens, including postmortem brain. We present 38 iPSC lines derived from MSA patients and relevant disease controls (spinocerebellar ataxia and PD, including alpha-synuclein triplication cases), 22 matched to whole-genome sequenced postmortem brain. iPSC models may facilitate matching patients to appropriate therapies, particularly in heterogeneous diseases for which patient-specific biology may elude animal models. We anticipate that deeply phenotyped and genotyped patient cohorts matched to cellular models will increase the likelihood of success in clinical trials for MSA. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Network autonomic analysis of post-acute sequelae of COVID-19 and postural tachycardia syndrome.
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Novak, Peter, Giannetti, Matthew P., Weller, Emily, Hamilton, Matthew J., Mukerji, Shibani S., Alabsi, Haitham S., Systrom, David, Marciano, Sadie P., Felsenstein, Donna, Mullally, William J., Pilgrim, David M., and Castells, Mariana
- Subjects
POSTURAL orthostatic tachycardia syndrome ,ORTHOSTATIC intolerance ,CEREBRAL circulation ,COVID-19 ,AUTONOMIC nervous system ,FLOW velocity - Abstract
Background: The autonomic nervous system (ANS) is a complex network where sympathetic and parasympathetic domains interact inside and outside of the network. Correlation-based network analysis (NA) is a novel approach enabling the quantification of these interactions. The aim of this study is to assess the applicability of NA to assess relationships between autonomic, sensory, respiratory, cerebrovascular, and inflammatory markers on post-acute sequela of COVID-19 (PASC) and postural tachycardia syndrome (POTS). Methods: In this retrospective study, datasets from PASC (n = 15), POTS (n = 15), and matched controls (n = 11) were analyzed. Networks were constructed from surveys (autonomic and sensory), autonomic tests (deep breathing, Valsalva maneuver, tilt, and sudomotor test) results using heart rate, blood pressure, cerebral blood flow velocity (CBFv), capnography, skin biopsies for assessment of small fiber neuropathy (SFN), and various inflammatory markers. Networks were characterized by clusters and centrality metrics. Results: Standard analysis showed widespread abnormalities including reduced orthostatic CBFv in 100%/88% (PASC/POTS), SFN 77%/88%, mild-to-moderate dysautonomia 100%/100%, hypocapnia 87%/100%, and elevated inflammatory markers. NA showed different signatures for both disorders with centrality metrics of vascular and inflammatory variables playing prominent roles in differentiating PASC from POTS. Conclusions: NA is suitable for a relationship analysis between autonomic and nonautonomic components. Our preliminary analyses indicate that NA can expand the value of autonomic testing and provide new insight into the functioning of the ANS and related systems in complex disease processes such as PASC and POTS. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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6. MemAID: Memory advancement with intranasal insulin vs. placebo in type 2 diabetes and control participants: a randomized clinical trial.
- Author
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Novak, Vera, Mantzoros, Christos S., Novak, Peter, McGlinchey, Regina, Dai, Weiying, Lioutas, Vasileios, Buss, Stephanie, Fortier, Catherine B., Khan, Faizan, Aponte Becerra, Laura, and Ngo, Long H.
- Subjects
TYPE 2 diabetes ,CLINICAL trials ,VERBAL memory ,EXECUTIVE function ,INSULIN ,WEIGHT gain - Abstract
Background: This study aimed at assessing the long-term effects of intranasal insulin (INI) on cognition and gait in older people with and without type 2 diabetes mellitus (T2DM). Methods: Phase 2 randomized, double-blinded trial consisted of 24 week treatment with 40 IU of INI (Novolin
® R, off-label use) or placebo (sterile saline) once daily and 24 week follow-up. Primary outcomes were cognition, normal (NW), and dual-task (DTW) walking speeds. Of 244 randomized, 223 completed baseline (51 DM-INI, 55 DM-Placebo, 58 Control-INI, 59 Control-Placebo; 109 female, 65.8 ± 9.1; 50–85 years old); 174 completed treatment (84 DM, 90 Controls); 156 completed follow-up (69 DM). Results: DM-INI had faster NW (~ 7 cm/s; p = 0.025) and DTW on-treatment (p = 0.007; p = 0.812 adjusted for baseline difference) than DM-Placebo. Control-INI had better executive functioning on-treatment (p = 0.008) and post-treatment (p = 0.007) and verbal memory post-treatment (p = 0.004) than Control-Placebo. DM-INI increased cerebral blood flow in medio-prefrontal cortex (p < 0.001) on MRI. Better vasoreactivity was associated with faster DTW (p < 0.008). In DM-INI, plasma insulin (p = 0.006) and HOMA-IR (p < 0.013) decreased post-treatment. Overall INI effect demonstrated faster walking (p = 0.002) and better executive function (p = 0.002) and verbal memory (p = 0.02) (combined DM-INI and Control-INI cohort, hemoglobin A1c-adjusted). INI was not associated with serious adverse events, hypoglycemic episodes, or weight gain. Conclusion: There is evidence for positive INI effects on cognition and gait. INI-treated T2DM participants walked faster, showed increased cerebral blood flow and decreased plasma insulin, while controls improved executive functioning and verbal memory. The MemAID trial provides proof-of-concept for preliminary safety and efficacy and supports future evaluation of INI role to treat T2DM and age-related functional decline. [ABSTRACT FROM AUTHOR]- Published
- 2022
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7. Qpack—a Python package for QASAT—quantitative scale for grading cerebral blood flow, autonomic testing, and skin biopsies.
- Author
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Novak, Peter
- Abstract
Quantitative grading of testing has research and clinical relevance. QASAT (quantitative scale for grading of cardiovascular reflex tests, transcranial Doppler, sudomotor testing, and small fiber densities from skin biopsies) is an objective instrument for grading dysautonomia, related small fiber neuropathy and cerebral blood flow. QASAT uses established autonomic tests (deep breathing, Valsalva maneuver, tilt test, sudomotor test) and skin biopsies for assessment of small fibers. Calculations of scores are complex. This paper presents a qpack—an open source software package that implements QASAT in a Python programming language. The qpack automatically generates reproducible scores of each test and reduces calculation errors. Datasets for verifying the correct qpack implementation are provided. The goal of qpack is to facilitate availability, reproducibility, and quality of autonomic studies and skin biopsies for assessment of small fibers. Qpack is easy to use with standard Python distributions, can be incorporated into routine clinical or research autonomic testing and it is freely available. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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8. Logic and the classical theory of mind.
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Novak, Peter
- Subjects
LOGIC ,MODAL analysis - Abstract
Discusses the partial formalization of the logic implicit in Classical Theory of Mind (CTM). Definition of the modal properties and relations of propositions; Information on the principles of the CTM; How logical modality is defined.
- Published
- 1998
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9. Correction to: Clinical trial-ready patient cohorts for multiple system atrophy: coupling biospecimen and iPSC banking to longitudinal deep-phenotyping.
- Author
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Ndayisaba, Alain, Pitaro, Ariana T., Willett, Andrew S., Jones, Kristie A., de Gusmao, Claudio Melo, Olsen, Abby L., Kim, Jisoo, Rissanen, Eero, Woods, Jared K., Srinivasan, Sharan R., Nagy, Anna, Nagy, Amanda, Mesidor, Merlyne, Cicero, Steven, Patel, Viharkumar, Oakley, Derek H., Tuncali, Idil, Taglieri-Noble, Katherine, Clark, Emily C., and Paulson, Jordan
- Subjects
MULTIPLE system atrophy ,SCHOLARSHIPS ,CORPORATE directors ,WOMEN'S hospitals ,PARKINSON'S disease - Abstract
This document is a correction notice for an article published in the journal Cerebellum. The correction states that an author, Dr. Anoopum Gupta, was inadvertently dropped from the author list due to a clerical error. Dr. Gupta contributed the Neurobooth methodology to the work. The funding section of the article has also been amended to include various sources of support. The document does not provide any data availability. [Extracted from the article]
- Published
- 2024
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10. Classification of orthostatic intolerance through data analytics.
- Author
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Gilmore, Steven, Hart, Joseph, Geddes, Justen, Olsen, Christian H., Mehlsen, Jesper, Gremaud, Pierre, and Olufsen, Mette S.
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ORTHOSTATIC intolerance ,DATA analytics ,CONSCIOUSNESS ,HEART rate monitoring ,MACHINE learning - Abstract
Imbalance in the autonomic nervous system can lead to orthostatic intolerance manifested by dizziness, lightheadedness, and a sudden loss of consciousness (syncope); these are common conditions, but they are challenging to diagnose correctly. Uncertainties about the triggering mechanisms and the underlying pathophysiology have led to variations in their classification. This study uses machine learning to categorize patients with orthostatic intolerance. We use random forest classification trees to identify a small number of markers in blood pressure, and heart rate time-series data measured during head-up tilt to (a) distinguish patients with a single pathology and (b) examine data from patients with a mixed pathophysiology. Next, we use Kmeans to cluster the markers representing the time-series data. We apply the proposed method analyzing clinical data from 186 subjects identified as control or suffering from one of four conditions: postural orthostatic tachycardia (POTS), cardioinhibition, vasodepression, and mixed cardioinhibition and vasodepression. Classification results confirm the use of supervised machine learning. We were able to categorize more than 95% of patients with a single condition and were able to subgroup all patients with mixed cardioinhibitory and vasodepressor syncope. Clustering results confirm the disease groups and identify two distinct subgroups within the control and mixed groups. The proposed study demonstrates how to use machine learning to discover structure in blood pressure and heart rate time-series data. The methodology is used in classification of patients with orthostatic intolerance. Diagnosing orthostatic intolerance is challenging, and full characterization of the pathophysiological mechanisms remains a topic of ongoing research. This study provides a step toward leveraging machine learning to assist clinicians and researchers in addressing these challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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11. Felid bedrooms with a panoramic view: selection of resting sites by Eurasian lynx (Lynx lynx) in a karstic landscape.
- Author
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Hočevar, Lan, Oliveira, Teresa, and Krofel, Miha
- Subjects
LYNX ,HABITAT selection ,BEDROOMS ,LANDSCAPES ,UNGULATES ,FELIDAE - Abstract
Eurasian lynx (Lynx lynx) is a crepuscular-nocturnal carnivore and mostly spends daytime resting. Although resting sites represent an important part of the lynx habitat and can be negatively affected by human activities, it is still poorly known how lynx select these sites, especially in regions with rugged topography characteristic for much of the species' range. We analysed microscale habitat selection of lynx resting sites at the home-range level in a karstic landscape of the Dinaric Mountains, Slovenia, using a use-availability study design. We also searched for differences in the selection of resting sites in respect to the presence of ungulate kills, which often limit the available resting sites during the prey-consumption period. Using generalised linear mixed models (GLMM), we tested which environmental features and human infrastructure are important for lynx when choosing resting sites. Lynx selected mountain ridges and hilltops, as well as locations with steeper slopes and lower local visibility. Such locations likely provide concealment from potential danger or prey and, at the same time, offer good overview of the surroundings. There was also a tendency to avoid forest cabins and to select rocky terrain and southern exposures, but support in the data for this was lower. When lynx were not limited by the presence of fresh kill, the selection tended to be stronger, but the differences were not significant, except for visibility, which was lower at resting sites near prey remains. Results likely reflect high availability of suitable resting sites in a rugged terrain of karstic landscape. Significance statement: Animals are often most vulnerable during sleep, thus the resting site should ideally provide them with cover to reduce exposure and at the same time give them good overview of the surroundings to detect any approaching danger. We used snow tracking and GPS telemetry, for the first time in combination with data from activity sensors, to reliably determine resting sites of Eurasian lynx in a rugged karstic landscape. We showed how lynx face the trade-off of the need to be concealed, yet at the same time attain good view, by selecting structured microhabitats on top of the ridges and on steep slopes. Our results also suggest that in the regions with rugged terrain the influence of human infrastructure might be lower compared to the study areas of previous research. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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12. Electrochemical skin conductance: a systematic review.
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Novak, Peter
- Subjects
FUNCTIONAL assessment ,META-analysis ,PERSPIRATION ,SKIN - Abstract
Purpose: Currently available techniques for the evaluation of small fiber neuropathy and related sudomotor function remain suboptimal. Electrochemical skin conductance (ESC) has recently been introduced as a simple noninvasive and fast method for the detection of sudomotor dysfunction. The purpose of this review is to synthesize and appraise research using ESC measurements for sudomotor evaluation in adults.Methods: Electronic databases including MEDLINE and Google Scholar were searched (up to March 13, 2017). The search strategy included the following terms: "electrochemical skin conductance," "Sudoscan," and "EZSCAN." Evidence was graded according to defined quality indicators including (1) level of evidence; (2) use of established tests as reference tests (e.g., quantitative sudomotor axon test [QSART], sympathetic skin responses [SSR], thermoregulatory sweat test [TST], and skin biopsies to assess sudomotor and epidermal small fibers); (3) use of consecutive/non-consecutive subjects; and (4) study design (prospective/retrospective).Results: A total of 24 studies met the inclusion criteria. These were classified into preclinical, normative, comparative/diagnostic, or interventional. ESC measurement properties, diagnostic accuracy, and similarities to and differences from established tests were examined.Conclusions: ESC measurements expand the arsenal of available tests for the evaluation of sudomotor dysfunction. The advantages and disadvantages of ESC versus established tests for evaluating sudomotor/small fiber function reviewed herein should be used as evidence to inform future guidelines on the assessment of sudomotor function. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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13. Multi-agent programming contest 2017.
- Author
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Ahlbrecht, Tobias, Dix, Jürgen, and Fiekas, Niklas
- Abstract
We present the twelfth edition of the Multi-Agent Programming Contest (
https://multiagentcontest.org ), an annual, community-serving competition that attracts groups from all over the world. Our contest facilitates comparison of multi-agent systems and provides a concrete problem that is interesting in itself and well-suited to be tackled in educational environments. This time, seven teams competed using strictly agent-based as well as traditional programming approaches. [ABSTRACT FROM AUTHOR]- Published
- 2018
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14. BackMatter.
- Author
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Jung, Stefanie and Krebs, Peter
- Published
- 2016
15. Maintaining customary harvesting of freshwater resources: sustainable Indigenous livelihoods in the floodplains of northern Australia.
- Author
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Ligtermoet, Emma
- Subjects
AQUATIC resource management ,FLOODPLAINS ,SUSTAINABLE development ,FRESH water ,INDIGENOUS peoples - Abstract
Freshwater resources underpin multiple livelihood systems around the world, particularly in highly productive tropical floodplain regions. Sustaining Indigenous people's access to freshwater resources for customary harvesting, while developing alternative livelihood strategies can be challenging. The sustainable livelihoods approach was applied to examine the ways in which multiple livelihoods in the East Alligator River floodplain region in northern Australia influence Aboriginal people's access to freshwater resources for customary harvesting. Interviews with Aboriginal residents were conducted to understand changes to freshwater customary harvesting practices. The dominant floodplain-based livelihoods analysed were pastoralism, biodiversity conservation and tourism and they were found to generate both opportunities and constraints for sustaining freshwater customary harvesting. Opportunities were provided through facilitating regular access to floodplain country and opportunistic access for harvesting, which assists in sustaining bio-cultural knowledge. Partnerships developed through these mainstream livelihoods built human capacity that enhanced all livelihood resource capitals (natural, human, social, financial and physical). Three key ways the dominant livelihoods constrained access to key freshwater resources were identified. Tourism required sacrificing certain hunting places and had to accommodate recreational fishing pressure. The successful recovery of the saltwater crocodile population through biodiversity conservation policy has inadvertently reduced people's customary access to in-stream resources. Pastoralism on the floodplain had restricted traditional floodplain burning practices associated with accessing aestivating long-necked turtles, affecting access and abundance. These findings highlight the need for the development of remote Indigenous livelihood strategies to make explicit their influences on freshwater customary harvesting practices, to better support their maintenance amongst multiple, non-customary floodplain livelihoods. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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16. FrontMatter.
- Published
- 2015
17. Temporal variation in benthic primary production in streams of the Australian wet-dry tropics.
- Author
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Garcia, Erica, Pettit, Neil, Warfe, Danielle, Davies, Peter, Kyne, Peter, Novak, Peter, and Douglas, Michael
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BENTHIC ecology ,PRIMARY productivity (Biology) ,MARINE productivity ,AQUATIC invertebrates ,WATER quality - Abstract
In the Australian wet-dry tropics, seasonal changes in hydrology can influence abiotic conditions and consequently influence standing stocks of benthic biomass and production. While there is some understanding of these processes at riverscape scales, effects of seasonal hydrology on benthic biomass and production in low-order streams remain largely unquantified. We observed changes in water quality, algal and macroinvertebrate biomass, and stream benthic primary productivity over a 15-month period in three low-order streams with contrasting flow regimes in the wet-dry tropics of northern Australia. Water quantity and quality showed a distinct seasonal signature reflected in seasonal peaks in algal (maximum 1.29 µg cm) and macroinvertebrate biomass (maximum 0.24 g m), and productivity (maximum 0.41 g C m days). In particular, transitional periods between dry and wet seasons were key times of elevated production and algal biomass. Overall, variation in biomass and benthic primary production was greater between seasons than among streams indicating that extrapolation between seasons may not be appropriate. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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18. BackMatter.
- Published
- 2011
19. FrontMatter.
- Author
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Berning, Detlev and Schwamberger, Gerald
- Published
- 2008
20. BackMatter.
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Fischer, Petra M.
- Published
- 2007
21. Intentions and Strategies in Game-Like Scenarios.
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Bento, Carlos, Cardoso, Amílcar, Dias, Gaël, Jamroga, Wojciech, der Hoek, Wiebe, and Wooldridge, Michael
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In this paper, we investigate the link between logics of games and "mentalistic" logics of rational agency, in which agents are characterized in terms of attitudes such as belief, desire and intention. In particular, we investigate the possibility of extending the logics of games with the notion of agents' intentions (in the sense of Cohen and Levesque's BDI theory). We propose a new operator that can be used to formalize reasoning about outcomes of strategies in game-like scenarios. We briefly discuss the relationship between intentions and goals in this new framework, and show how to capture dynamic logic-like constructs. Finally, we demonstrate how game-theoretical concepts like Nash equilibrium can be expressed to reason about rational intentions and their consequences. Keywords: Multi-agent systems, strategic reasoning, common sense reasoning. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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22. Development of PDMS-based flexible dry type SEMG electrodes by micromachining technologies.
- Author
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Jung, Jung, Cha, Doo, Kim, Deok, Yang, Hee, Choi, Kyo, Choi, Jong, and Chang, Sung
- Subjects
POLYDIMETHYLSILOXANE ,ELECTRODES ,MYOELECTRIC prosthesis ,ELECTROMYOGRAPHY ,MICROMACHINING ,ELECTRIC potential - Abstract
The authors developed PDMS (polydimethylsiloxane)-based dry type surface electromyography (SEMG) electrodes for myoelectric prosthetic hands. The SEMG electrodes were strongly recommended to be fabricated on a flexible substrate to be compatible with the surface of skin. In this study, the authors designed a bar-shaped dry-type flexible SEMG electrodes comprised of two input electrodes and a reference electrode on a flexible PDMS substrate to measure EMG signals. The space distance between each electrode with a size of 10 mm × 2 mm was chosen to 18 mm to get optimal result according to the simulation result with taking into consideration the conduction velocity and the median frequency of EMG signals. Raw EMG signals were measured from Brachioradialis, Biceps brachii, deltoideus, and pectoralis major muscles, to drive the application of the myoelectric hand prosthesis. Measured raw EMG signals were transformed to root mean square (RMS) EMG signals using Acqknowledge4.2. The experimental peak voltage values of RMS EMG signals from Brachioradialis, Biceps brachii, deltoideus, and pectoralis major muscles were 2.96 V, 4.45 V, 1.74 V, and 2.62 V, respectively. Values from the dry type flexible SEMG electrodes showed higher peak values than a commercially available wet type Ag-AgCl electrode. The study shows that the PDMS-based flexible electrode devised for measuring myoelectric signals from the surface of skin is more useful for prosthetic hands because of its greater sensitivity and flexibility. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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23. Leaf litter chemistry, decomposition and assimilation by macroinvertebrates in two tropical streams.
- Author
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Pettit, Neil, Davies, Tegan, Fellman, Jason, Grierson, Pauline, Warfe, Danielle, and Davies, Peter
- Subjects
MELALEUCA ,MASS loss (Astrophysics) ,FOOD chains ,RIPARIAN plants ,BIODEGRADATION ,RIVERS - Abstract
Riparian vegetation typically provides substantial allochthonous material to aquatic ecosystems where micro-organisms can play an important role in organic matter degradation which can support consumer biomass. We examined the effects of leaf litter quality (e.g., leaf nutrients, lignin and cellulose content), leaf species mixing, and microbial community diversity on in-stream breakdown rates of litter from dominant riparian trees ( Melaleuca argentea, M. leucadendra, and Nauclea orientalis) in both a perennial and intermittent river in Australia's wet-dry tropics. Leaf mass remaining after 82 days of in-stream incubation was negatively correlated ( P < 0.05) with initial leaf N and P content while initial lignin and cellulose content had no statistically significant effect. Breakdown rates of incubated leaves of both Melaleuca and Nauclea were significantly higher in mixed litter bags compared with single species litter bags. Although it was expected that leaf N content would decrease from initial levels during decomposition, we found either similar or slightly higher N content following in-stream incubation suggesting microbial colonisation increased overall N content. Stable isotopes of δC and δN for the major sources and consumers in both rivers provide evidence that leaf litter was an important macroinvertebrate food source in the perennial river where heavy shading may limit algal production. However, in the intermittent river where riparian cover was low, benthic algae were the major organic carbon source for consumers. Our findings suggest that riparian tree species influence rates of in-stream organic matter processing, microbial community composition, and aquatic food web dynamics in tropical wet-dry streams. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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24. The multi-agent programming contest from 2005-2010.
- Author
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Behrens, Tristan, Dastani, Mehdi, Dix, Jürgen, Köster, Michael, and Novák, Peter
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MULTIAGENT systems ,ARTIFICIAL intelligence software ,COMPUTER programming ,CONTESTS ,PROGRAMMING languages - Abstract
The is an annual international event on programming multi-agent systems: Teams of agents participate in a simulated cooperative scenario. It started in 2005 and is organised in 2010 for the sixth time. The contest is an attempt to stimulate research in the area of multi-agent system development and programming by (i) identifying key problems in the field and (ii) collecting suitable benchmarks that can serve as milestones for testing multi-agent programming languages, platforms and tools. This article provides a short history of the contest since it started and reports in more detail on the cows and cowboys scenario implemented for the 2008, 2009 and 2010 contest editions. We briefly discuss the underlying technological background and conclude with a critical discussion of the experiences and lessons learned. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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25. Improving e-payment security using Elliptic Curve Cryptosystem.
- Author
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Vincent, O. R., Folorunso, O., and Akinde, A. D.
- Subjects
ELECTRONIC commerce ,INTERNET sales ,COMPUTER crimes ,CRYPTOGRAPHY ,BANKING industry automation ,COMPUTER security - Abstract
The use of e-commerce has been associated with a lot of skepticism and apprehension due to some crimes associated with e-commerce and specifically to payment systems. The secure socket layer (SSL) protocol is trusted in this regard to secure transactions for sensitive applications like e-commerce. Unfortunately, the use of SSL protocol causes slow response time on the server which is a major cause of frustration for on-line shoppers. In this paper, we propose a secured credit-debit card payment systems based on Elliptic Curve Cryptosystem (ECC). We first examined ECC algorithm over prime fields GF( p), implement our proposed method using a typical transaction involving credit/debit card numbers and compared the performance with RSA cryptosystem. Our result shows that ECC is faster in terms of response to transaction request and occupies less memory space than equivalent RSA system. Thus, these makes it more suitable public Key cryptography scheme for application in a constraint open environment like payment system where fast operations are needed. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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26. Assessment of the variability in the anatomical position and size of the subthalamic nucleus among patients with advanced Parkinson’s disease using magnetic resonance imaging.
- Author
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Daniluk, Slawomir, Davies, Keith G., Ellias, Samuel A., Novak, Peter, and Nazzaro, Jules M.
- Subjects
PARKINSON'S disease ,MAGNETIC resonance imaging ,PATIENTS ,BRAIN stimulation ,SURGERY - Abstract
Targeting of the subthalamic nucleus (STN) during deep brain stimulation (DBS) surgery using standard atlas coordinates is used in some centers. Such coordinates are accurate for only a subgroup of patients, and subgroup size depends on the extent of inter-individual variation in STN position/size and degree to which atlas represents average anatomical relations. Few studies have addressed this issue. Sixty-two axial T
2 -weighted magnetic resonance (MR) images of the brain (1.5 T) were obtained before STN-DBS in 62 patients (37 males) with Parkinson’s disease using a protocol optimized for STN visualization. Image distortion was within sub-millimeter range. Midcommissural point (MCP)-derived coordinates of STN borders, STN center, and other brain landmarks were obtained using stereotactic software. MR-derived measurements were compared to Schaltenbrand and Wahren Atlas. We evaluated 117 best-visualized STNs. STN dimensions and coordinates of its center were highly variable. STN lateral coordinate ranged 8.7 mm–14.5 mm from MCP, A-P coordinate 3.5 mm posterior to 0.5 mm anterior to MCP, and vertical coordinate 1.3 mm–6 mm below MCP. The antero-posterior nucleus dimension varied by 8 mm and lateral-medial dimension by 5.8 mm. Differences between mean values of MR-derived data sets and Atlas values were statistically significant but moderate, excluding AC-PC length, for which the Atlas value was below the 1st percentile of the MR data set. The STN lateral coordinate strongly correlated with the width of the third ventricle (r = 0.73, p < 0.001). It is now possible to directly evaluate STNs at 1.5 T with minimal image distortion, which reveals variation in STN position and dimensions in the range of nucleus size. This puts under question the rationale of use of standard STN coordinates during DBS surgery. [ABSTRACT FROM AUTHOR]- Published
- 2010
- Full Text
- View/download PDF
27. Meteorological study of the first observation of red sprites from Poland.
- Author
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Iwański, Rafał, Odzimek, Anna, Clausen, Lasse, Kanawade, Vijay, Cnossen, Ingrid, and Edberg, Niklas
- Abstract
The first red sprite events scientifically observed from Poland on 20/21 July 2007, during the two-week SPARTAN Sprite-Watch 2007 campaign, are analysed in the context of the meteorological conditions over Poland and the Czech Republic at that time. The phenomena were detected and recorded from the IMWM High-Mountain Meteorological Observatory at Mount Śnieżka using a low-light television CCD camera. Meteorological conditions over the south-west Poland were monitored on the basis of information from the Polish and Czech meteorological radar and lightning detection systems and also from satellite infra-red difference images, indicating the development of thunderstorm clouds over central Europe. Four sprite events detected in the night-time of 20/21 July indicate that in this region sprites are produced by massive storm cells built on warm fronts which are supplied by warm and humid tropical air masses during local summer thunderstorm season. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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- View/download PDF
28. The effects of body mass index on cerebral blood flow velocity.
- Author
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Selim, Magdy, Jones, Richard, Novak, Peter, Zhao, Peng, and Novak, Vera
- Subjects
CEREBRAL circulation ,BODY mass index ,CEREBROVASCULAR disease risk factors ,OBESITY ,HYPERTENSION ,TYPE 2 diabetes - Abstract
Obesity is a risk factor for cerebrovascular disease. We aimed to determine the effects of high body mass index (BMI) on cerebral blood flow regulation in patients with type-2 diabetes mellitus, hypertension, and stroke. We analyzed data from 90 controls, 30 diabetics, 45 hypertensives, and 32 ischemic stroke patients who underwent transcranial Doppler for evaluation of blood flow velocities (BFV) in the middle cerebral arteries (MCA) and cerebrovascular resistance (CVR) during supine rest and head-up tilt. This study was a cross-sectional analysis. We used a structural equation multiple indicators modeling to determine the effects of BMI and other background variables (age, sex, race, smoking, alcohol use, and systolic blood pressure) on cerebral BFV. Higher BMI ( P = 0.02) and age ( P = 0.004) were associated with lower mean BFV during baseline, independent of diagnosis of diabetes mellitus, hypertension or stroke, and after adjusting for all background variables and vessel diameters. Men, especially those with stroke, had a lower mean BFV than women ( P = 0.01). CVR increased with BMI ( P = 0.001) at baseline and during head-up tilt ( P = 0.02), and was elevated in obese subjects ( P = 0.004) compared to normal weight subjects across all groups. High BMI is associated with a reduction in cerebral BFV and increased CVR. These findings indicate that obesity can adversely affect cerebral blood flow and resistance in the cerebrovascular bed, independent of diagnosis of type-2 diabetes, hypertension or stroke. Obesity may contribute to cerebromicrovascular disease, and affect clinical functional outcomes of the older population. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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- View/download PDF
29. 19TH International Symposium on the Autonomic Nervous System, Kauai Marriott Resort & Beach Club Kauai, Hawaii, October 29–November 1, 2008.
- Subjects
CONFERENCES & conventions ,AUTONOMIC nervous system - Abstract
The article presents the program for the 19th International Symposium on the Autonomic Nervous System at Kauai Marriott Resort & Beach club in Kauai, Hawaii on October 29 to November 1, 2008.
- Published
- 2008
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30. Öffentliches gesundheitswesen: Nachrichten.
- Author
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Brähler, Elmar, Bullinger, Monika, Gerber, Wolf-Dieter, Meyer-Probst, Bernhard, Novak, Peter, Siegrist, Johannes, and Tewes, Uwe
- Published
- 2001
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31. Ernährungsgewohnheiten bei Beschäftigten in der Metallindustrie: Determinanten und Muster.
- Author
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Reime, Birgit, Born, Jürgen, Novak, Peter, Wanek, Volker, and Hagel, Elisabeth
- Abstract
Copyright of Social & Preventive Medicine is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1998
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32. Time/frequency mapping of the heart rate, blood pressure and respiratory signals.
- Author
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Novak, P. and Novak, V.
- Abstract
The discrete Wigner distribution (DWD) was implemented for the time/frequency mapping of variations of R-R interval, blood pressure and respiratory signals. The smoothed cross-DWD was defined and the modified algorithm for the smoothed auto- and cross-DWD was proposed. Spurious cross-terms were suppressed using a smoothing data window and a Gauss frequency window. The DWD is easy to implement using the FFT algorithm. Examples show that the DWD follows well the instantaneous changes of spectral content of cardiovascular and respiratory signals which characterise the dynamics of autonomic nervous system responses. [ABSTRACT FROM AUTHOR]
- Published
- 1993
- Full Text
- View/download PDF
33. Complications in the First Year of Laparoscopic Gastric Banding: Is It Acceptable?
- Author
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Holeczy, Pavol, Novak, Peter, and Kralova, Alzbeta
- Abstract
Background: From December 1997 to December 1998, 25 laparoscopic adjustable silicone gastric banding (LASGB) procedures were done without previous experience in bariatric surgery. Body mass index (BMI) ranged from 37 to 57 kg/m
2 (average 45.5 kg/m2 ). Methods: Retrospective analysis of the 1-year experience was done. Operating time was measured, and BMI and complications were reviewed. Results: Five complications were observed. There was a complication rate of 20%. On two occasions, it was gastric wall slippage, and both were corrected laparoscopically. In one patient, the intususception of the gastric wall through the band resulted after profuse vomiting. Removal of the band was necessary, with conversion to an open procedure. On two occassions, the infection of the port-site was observed, in one of these patients, port removal was necessary. No antibiotic prophylaxis was used. Conclusion: Despite lack of experience in bariatric surgery in these laparoscopic surgeons, the complications with LASGB appear to be acceptable. Although prior bariatric surgical experience is preferable. [ABSTRACT FROM AUTHOR]- Published
- 1999
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34. FrontMatter.
- Published
- 2014
35. FrontMatter.
- Published
- 2013
36. FrontMatter.
- Published
- 2008
37. FrontMatter.
- Published
- 2008
38. FrontMatter.
- Published
- 2008
39. Untitled.
- Published
- 2008
40. FrontMatter.
- Published
- 2008
41. FrontMatter.
- Published
- 2008
42. FrontMatter.
- Published
- 2008
43. FrontMatter.
- Published
- 2008
44. FrontMatter.
- Published
- 2006
45. Buchbesprechungen.
- Author
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Gerber, Niklaus, Frentzel-Beyme, Rainer, Grüninger, Ueli, Bucher, Heiner, Brunner, Anne, and Hornung, Rainer
- Published
- 1991
- Full Text
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46. Neue Bücher Nouveaux livres.
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Biener, K., Spreng, H., and Schüler, G.
- Published
- 1983
- Full Text
- View/download PDF
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