1,302 research outputs found
Criteria for Optimum Mixture - Ratio Distribution Using Several Types of Impinging-Stream Injector Elements
Empirical correlations are given relating the mixture-ratio distributions produced by various configurations of impinging-stream injectors and the ratios of density, velocity, and orifice cross-sectional area of the two fluids being mixed. Injector-element designs studied are two-on-one, two-on-two, and four-on-one
Integrated cross-domain object storage in working memory: Evidence from a verbal-spatial memory task
Working-memory theories often include domain-specific verbal and visual stores (e.g., the phonological and visuospatial buffers of Baddeley, 1986), and some also posit more general stores thought to be capable of holding verbal or visuospatial materials (Baddeley, 2000; Cowan, 2005). However, it is currently unclear which type of store is primarily responsible for maintaining objects that include components from multiple domains. In these studies, a spatial array of letters was followed by a single probe identical to an item in the array or differing systematically in spatial location, letter identity, or their combination. Concurrent verbal rehearsal suppression impaired memory in each of these trial types in a task that required participants to remember verbal-spatial binding, but did not impair memory for spatial locations if the task did not require verbal-spatial binding for a correct response. Thus, spatial information might be stored differently when it must be bound to verbal information. This suggests that a cross-domain store such as the episodic buffer of Baddeley (2000) or the focus of attention of Cowan (2001) might be used for integrated object storage, rather than the maintenance of associations between features stored in separate domain-specific buffers
Mechanical Percussion Devices: A Survey of Practice Patterns Among Healthcare Professionals
# Background
Mechanical percussion devices have become popular among sports medicine professionals. These devices provide a similar effect as manual percussion or tapotement used in therapeutic massage. To date, there are few published studies or evidence-based guidelines for these devices. There is a need to understand what professionals believe about this technology and how they use these devices in clinical practice.
# Purpose
To survey and document the knowledge, clinical application methods, and use of mechanical percussion devices among healthcare professionals in the United States.
# Design
Cross-sectional survey study.
# Methods
A 25 question online survey was emailed to members of the National Athletic Trainers Association, Academy of Orthopedic Physical Therapy, and American Academy of Sports Physical Therapy.
# Results
Four hundred twenty-five professionals completed the survey. Most professionals (92%, n=391) used devices from two manufacturers: Hyperice® and Theragun®. Seventy-seven percent directed clients to manufacturer and generic websites (n=329) to purchase devices. Most respondents used a medium and low device speed setting for pre- and post-exercise (62%, n=185), pain modulation (59%, n=253), and myofascial mobility (52%, n=222). A large proportion of respondents preferred a total treatment time between 30 seconds and three minutes (36-48%, n=153-204) or three to five minutes (18-22%, n=76-93). Most respondents (54-69%, n=229-293) believed that mechanical percussion increases local blood flow, modulates pain, enhances myofascial mobility, and reduces myofascial restrictions. Most respondents (72%, n=305) were influenced by other colleagues to use these devices. Sixty-six percent used patient reported outcomes (n=280) to document treatment efficacy. Live instruction was the most common mode of education (79%, n=334).
# Conclusion
These results are a starting point for future research and provide insight into how professionals use mechanical percussion devices. This survey also highlights the existing gap between research and practice. Future research should examine the efficacy of this technology and determine consensus-based guidelines.
# Level of Evidence
Flexible attention allocation to visual and auditory working memory tasks: manipulating reward induces a trade-off
Prominent roles for general attention resources are posited in many models of working memory, but the manner in which these can be allocated differs between models or is not sufficiently specified. We varied the payoffs for correct responses in two temporally-overlapping recognition tasks, a visual array comparison task and a tone sequence comparison task. In the critical conditions, an increase in reward for one task corresponded to a decrease in reward for the concurrent task, but memory load remained constant. Our results show patterns of interference consistent with a trade-off between the tasks, suggesting that a shared resource can be flexibly divided, rather than only fully allotted to either of the tasks. Our findings support a role for a domain-general resource in models of working memory, and furthermore suggest that this resource is flexibly divisible
‘We achieve the impossible’: discourses of freedom and escape at music festivals and free parties
In this article, we explore the notion of freedom as a form of governance within contemporary consumer culture in a sphere where ‘freedom’ appears as a key component: outdoor music-based leisure events, notably music festivals and free parties. ‘Freedom’ is commodified as central to the marketing of many music festivals, which now form a highly commercialised sector of the UK leisure industry, subject to various regulatory restrictions. Free parties, in contrast, are unlicensed, mostly illegal and far less commercialised leisure spaces. We present data from two related studies to investigate how participants at three major British outdoor music festivals and a small rural free party scene draw on discourses of freedom, escape and regulation. We argue that major music festivals operate as temporary bounded spheres of ‘licensed transgression’, in which an apparent lack of regulation operates as a form of governance. In contrast, free parties appear to ‘achieve the impossible’ by creating alternative (and illegal) spaces in which both freedom and regulation are constituted in different ways compared to music festival settings
Cross-domain interference costs during concurrent verbal and spatial serial memory tasks are asymmetric
Some evidence suggests that memory for serial order is domain-general. Evidence also points to asymmetries in interference between verbal and visual-spatial tasks. We confirm that concurrently remembering verbal and spatial serial lists provokes substantial interference compared with remembering a single list, but we further investigate the impact of this interference throughout the serial position curve, where asymmetries are indeed apparent. A concurrent verbal order memory task affects spatial memory performance throughout the serial positions of the list, but performing a spatial order task affects memory for the verbal serial list only for early list items; in the verbal task only, the final items are unaffected by a concurrent task. Adding suffixes eliminates this asymmetry, resulting in impairment throughout the list for both tasks. These results suggest that domain-general working memory resources may be supplemented with resources specific to the verbal domain, but perhaps not with equivalent spatial resources
Recommended from our members
Benthic foraminifer stable isotope record from Site 849 (0 - 5 Ma) : local and global climate changes
Benthic foraminifer and δ¹³C data from Site 849, on the west flank of the East Pacific Rise (0°11'N, 110°3l'W; 3851 m), give relatively continuous records of deep Pacific Ocean stable isotope variations between 0 and 5 Ma. The mean sample spacing is 4 k.y. Most analyses are from Cibicides wuellerstorfi> but isotopic offsets relative to Uvigerina peregrina appear roughly constant. Because of its location west of the East Pacific Rise, Site 849 yields a suitable record of mean Pacific Ocean δ¹³C, which approximates a global oceanic signal. The ~lOO-k.y.-period climate cycle, which is prevalent in δ¹⁸O does not dominate the long-term δ¹³C record. For δ¹³C, variations in the -400- and 41-k.y. periods are more important. Phase lags of δ¹³C relative to ice volume in the 41- and 23-k.y. bands are consistent with δ¹³C as a measure of organic biomass. A model-calculated exponential response time of 1-2 k.y. is appropriate for carbon stored in soils and shallow sediments responding to glacial-interglacial climate change. Oceanic δ¹³C leads ice volume slightly in the 100-k.y. band, and this suggests another process such as changes in continental weathering to modulate mean river δ¹³C at long periods.
The δ¹³C record from Site 849 diverges from that of Site 677 in the Panama Basin mostly because of decay of ¹³C-depleted organic carbon in the relatively isolated Panama Basin. North Atlantic to Pacific δ¹³C differences calculated using published data from Sites 607 and 849 reveal variations in Pliocene deep water within the range of those of the late Quaternary. Maximum δ¹³C contrast between these sites, which presumably reflects maximum influx of high-δ¹³C northern source water into the deep North Atlantic Ocean, occurred between 1.3 and 2.1 Ma, well after the initiation of Northern Hemisphere glaciation. Export of high-δ¹³C North Atlantic Deep Water from the Atlantic to the circumpolar Antarctic, as recorded by published δ'3C data from Subantarctic Site 704, appears unrelated to the North Atlantic-Pacific δ¹³C contrast. To account for this observation, we suggest that deep-water formation in the North Atlantic reflects northern source characteristics, whereas export of this water into the circumpolar Antarctic reflects Southern Hemisphere wind forcing. Neither process appears directly linked to ice-volume variations
Effects of Thyroxine Exposure on Osteogenesis in Mouse Calvarial Pre-Osteoblasts
The incidence of craniosynostosis is one in every 1,800-2500 births. The gene-environment model proposes that if a genetic predisposition is coupled with environmental exposures, the effects can be multiplicative resulting in severely abnormal phenotypes. At present, very little is known about the role of gene-environment interactions in modulating craniosynostosis phenotypes, but prior evidence suggests a role for endocrine factors. Here we provide a report of the effects of thyroid hormone exposure on murine calvaria cells. Murine derived calvaria cells were exposed to critical doses of pharmaceutical thyroxine and analyzed after 3 and 7 days of treatment. Endpoint assays were designed to determine the effects of the hormone exposure on markers of osteogenesis and included, proliferation assay, quantitative ALP activity assay, targeted qPCR for mRNA expression of Runx2, Alp, Ocn, and Twist1, genechip array for 28,853 targets, and targeted osteogenic microarray with qPCR confirmations. Exposure to thyroxine stimulated the cells to express ALP in a dose dependent manner. There were no patterns of difference observed for proliferation. Targeted RNA expression data confirmed expression increases for Alp and Ocn at 7 days in culture. The genechip array suggests substantive expression differences for 46 gene targets and the targeted osteogenesis microarray indicated 23 targets with substantive differences. 11 gene targets were chosen for qPCR confirmation because of their known association with bone or craniosynostosis (Col2a1, Dmp1, Fgf1, 2, Igf1, Mmp9, Phex, Tnf, Htra1, Por, and Dcn). We confirmed substantive increases in mRNA for Phex, FGF1, 2, Tnf, Dmp1, Htra1, Por, Igf1 and Mmp9, and substantive decreases for Dcn. It appears thyroid hormone may exert its effects through increasing osteogenesis. Targets isolated suggest a possible interaction for those gene products associated with calvarial suture growth and homeostasis as well as craniosynostosis. © 2013 Cray et al
ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries
This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors
Detection of Atmospheric Muon Neutrinos with the IceCube 9-String Detector
The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino
detector under construction at the geographic South Pole. The dominant
population of neutrinos detected in IceCube is due to meson decay in cosmic-ray
air showers. These atmospheric neutrinos are relatively well-understood and
serve as a calibration and verification tool for the new detector. In 2006, the
detector was approximately 10% completed, and we report on data acquired from
the detector in this configuration. We observe an atmospheric neutrino signal
consistent with expectations, demonstrating that the IceCube detector is
capable of identifying neutrino events. In the first 137.4 days of livetime,
234 neutrino candidates were selected with an expectation of 211 +/-
76.1(syst.) +/- 14.5(stat.) events from atmospheric neutrinos
- …