472 research outputs found

    Effects of Two Intensities of Exercise on Memory, Concentration, Planning, and Reasoning

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    Active workstations (e.g., desk cycles) have recently gained popularity as a means of reducing sedentary behavior in schools. In addition to physical benefits, teachers who have adopted active classrooms anecdotally report cognitive benefits such as students being more focused during instruction. In contrast, empirical work suggests that concurrent exercise has a negative effect on cognition (Lambourne & Tomporowski, 2010). The purpose of this study was to compare the effects of no exercise (CON), low-intensity exercise (LOW), and moderate-intensity exercise (MOD) on a series of cognitive measures. Young, healthy participants (n=48) were randomly assigned to either CON (sedentary), LOW (25-30% HRR), or MOD (50-55% HRR) groups. Those assigned to LOW and MOD exercised with a DeskCycle to achieve desired HR while those in CON sat passively at the Deskcycle. Four Cambridge Brain Sciences Inc. computerized tests were completed to assess planning, concentration, short-term memory, and reasoning while exercising. A self-paced word pair recall test was also administered during the exercise bout, and long-term recall of the word pairs was assessed 24 hours later. Separate one-way ANOVAs were conducted on each cognition test. A 3 (group) x 2 (test) RM ANCOVA with the amount of time spent during each test as covariates was used to assess immediate and delayed recall of word pairs. Groups did not differ in planning, concentration, short-term memory, or reasoning scores (p’s \u3e .05). In both immediate and delayed memory tests, MOD recalled fewer words than CON when controlling for test time (p=.049), and LOW was not different from either group (p\u3e .05). In the present study, exercise did not show any effect on planning, concentration, reasoning, or short-term memory. While previous research shows long-term memory is improved by exercise before or after learning (Roig, et al., 2013), moderate-intensity exercise that occurs during learning seems to impair long-term memory recall

    Metabolic responses of a phototrophic sponge to sedimentation supports transitions to sponge-dominated reefs

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    Declines in coral abundance have been linked to increased sedimentation at many locations across the world and at some of these locations there have been subsequent increases in sponge abundance. These shifts appear counterintuitive as sponges are suspension feeders and many rely on photosymbionts for carbon. At a sedimented reef in Indonesia (Wakatobi) corals have declined and the photoautotrophic sponge Lamellodysidea herbacea is now abundant. We hypothesise that this is partly due to L. herbacea's ability to clear its tissues of high levels of settled-sediment and compensate for associated metabolic demands by altering its respiration rate. Negligible detrimental effects to sponge tissue were observed after treatments up to five times the sedimentation rate of the highly sedimented reef. Rapid sediment clearance occurred that was potentially aided by mucus production. Finally, high sediment exposure caused an immediate reduction in respiration rate, likely due to reduced pumping to prevent clogging, whereas sustained high sedimentation caused an increase in respiration rate, potentially due to the energetic cost of mucus production. Our study provides evidence that some sponges can tolerate environments that appear unsuitable to many corals and with increased sedimentation this acclimation may support further transitions to sponge dominated reefs in the future

    Enumeration of leukocyte infiltration in solid tumors by confocal laser scanning microscopy

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    BACKGROUND: Leukocytes commonly infiltrate solid tumors, and have been implicated in the mechanism of spontaneous regression in some cancers. Conventional techniques for the quantitative estimation of leukocyte infiltrates in tumors rely on light microscopy of immunostained thin tissue sections, in which an arbitrary assessment (based on low, medium or high levels of infiltration) of antigen density is made by the pathologist. These estimates are relatively subjective and often require the opinion of a second pathologist. In addition, since thin tissue sections are cut, no data regarding the three-dimensional distribution of antigen can be obtained. RESULTS: To overcome these problems, we have designed a method to enumerate leukocyte infiltration into tumors, using confocal laser scanning microscopy of fluorescently immunostained leukocytes in thick tissue sections. Using image analysis software, a threshold was applied to eliminate unstained tissue and residual noise. The total antigen volume in the scanned tissue was calculated and divided by the mean cell volume (calculated by "seeding" ten individual cells) to obtain the cell count. Using this method, we compared the calculated leukocyte counts with those obtained manually by ten laboratory personnel. There was no significant difference (P > 0.05) between the cell counts obtained by either method. We then compared leukocyte infiltration into seven tumors and matched non-malignant tissue obtained from the periphery of the resected tissue. There was a significant increase in the infiltration of all leukocyte subsets into the tumors compared to minimal numbers in the non-malignant tissue. CONCLUSION: From these results we conclude that this method may be of considerable use for the enumeration of cells in tissues. Furthermore, since it can be performed by laboratory technical staff, less time input is required by the pathologist in assessing the degree of leukocyte infiltration into tumors

    Enhancing quantum transport in a photonic network using controllable decoherence

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    Transport phenomena on a quantum scale appear in a variety of systems, ranging from photosynthetic complexes to engineered quantum devices. It has been predicted that the efficiency of quantum transport can be enhanced through dynamic interaction between the system and a noisy environment. We report the first experimental demonstration of such environment-assisted quantum transport, using an engineered network of laser-written waveguides, with relative energies and inter-waveguide couplings tailored to yield the desired Hamiltonian. Controllable decoherence is simulated via broadening the bandwidth of the input illumination, yielding a significant increase in transport efficiency relative to the narrowband case. We show integrated optics to be suitable for simulating specific target Hamiltonians as well as open quantum systems with controllable loss and decoherence.Comment: 6 pages, 3 figure

    Body Weight Support on Anti-Gravity Treadmill Induces Less Physiological Strain While Running

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    The anti-gravity treadmill developed by AlterG® can be used as an alternative to traditional treadmill running. The AlterG® unloads an individual’s body weight through lower body positive pressure (LBPP) and can support up to 80% of an individual’s body weight. The cardiorespiratory response resulting from a bout of exercise on an AlterG® treadmill may be attenuated compared to similar exercise on a traditional treadmill. PURPOSE: The purpose of this study was to compare the physiological responses of running at 0%, 15%, 30%, and 45% of body weight support (BWS) on the AlterG® to a traditional treadmill. METHODS: Ten healthy, active males (n = 3) and females (n = 7) (mean ± SD; age 23 ± 3 yrs, weight 60 ± 9.4 kg, height 167.6 ± 6.4 cm) completed two separate treadmill sessions in a randomized order. The exercise sessions included running on an AlterG® treadmill at 6 mph and 1% grade with 0%, 15%, 30% and 45% BWS for 8 min each. The other exercise session included running on a traditional treadmill (TT) at 6 mph and 1% grade for 8 min. Oxygen consumption (VO2) and respiratory exchange ratio (RER) were measured every minute through indirect calorimetry. Heart rate (HR) was measured every minute with a heart rate monitor and values were averaged during the last five minutes of each exercise trial. Rating of perceived exertion (RPE) was measured every other minute. Multivariate ANOVA was used for statistical analysis for each dependent variable (p \u3c 0.05). RESULTS: BWS at 15%, 30% and 45% on the AlterG® treadmill significantly reduced VO2 18.5%, 28.3 and 33.7% compared to TT and 0%. Additionally, HR with BWS at 15%, 30% and 45% was significantly reduced 8.9%, 13.1% and 17.9% compared to TT and 0%. RER during 30% and 45% was significantly different (-8.6% and -7.4%) from TT. Perceived exertion during 45% BWS was significantly lower (10-20%) than all protocols. There was no significant difference in VO2 or HR reported between 30% and 45%. 0% BWS displayed no significant difference in VO2 or HR when compared to the traditional treadmill. CONCLUSION: Increasing the percentage of BWS while running on the AlterG® treadmill reduced VO2 and HR compared to TT and 0%. Greater levels of BWS (30% and 45%) resulted in lowered RER and perceived exertion (45% only). The AlterG® treadmill appears to lessen the physiological demands of running compared to a traditional treadmill

    Influenza-like Illness, the Time to Seek Healthcare, and Influenza Antiviral Receipt During the 2010–2011 Influenza Season— United States

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    Background. Few data exist describing healthcare-seeking behaviors among persons with influenza-like illness (ILI) or adherence to influenza antiviral treatment recommendations. Methods. We analyzed adult responses to the Behavioral Risk Factor Surveillance System in 31 states and the District of Columbia (DC) and pediatric responses in 25 states and DC for January–April 2011 by demographics and underlying health conditions. Results. Among 75 088 adult and 15 649 child respondents, 8.9% and 33.9%, respectively, reported ILI. ILI was more frequent among adults with asthma (16%), chronic obstruction pulmonary disease (COPD; 26%), diabetes (12%), heart disease (19%), kidney disease (16%), or obesity (11%). Forty-five percent of adults and 57% of children sought healthcare for ILI. Thirty-five percent of adults sought care ≤2 days after ILI onset. Seeking care ≤2 days was more frequent among adults with COPD (48%) or heart disease (55%). Among adults with a self-reported physician diagnosis of influenza, 34% received treatment with antiviral medications. The only underlying health condition with a higher rate of treatment was diabetes (46%). Conclusions. Adults with underlying health conditions were more likely to report ILI, but the majority did not seek care promptly, missing opportunities for early influenza antiviral treatment

    Two-photon quantum walks in an elliptical direct-write waveguide array

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    Integrated optics provides an ideal test bed for the emulation of quantum systems via continuous-time quantum walks. Here we study the evolution of two-photon states in an elliptic array of waveguides. We characterise the photonic chip via coherent-light tomography and use the results to predict distinct differences between temporally indistinguishable and distinguishable two-photon inputs which we then compare with experimental observations. Our work highlights the feasibility for emulation of coherent quantum phenomena in three-dimensional waveguide structures.Comment: 8 pages, 7 figure

    Correlated Lightning Mapping Array (LMA) and Radar Observations of the Initial Stages of Florida Triggered Lightning Discharges

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    We characterize the geometrical and electrical characteristics of the initial stages of nine Florida triggered lightning discharges using a Lightning Mapping Array (LMA), a C-band SMART radar, and measured channel-base currents. We determine initial channel and subsequent branch lengths, average initial channel and branch propagation speeds, and channel-base current at the time of each branch initiation. The channel-base current is found to not change significantly when branching occurs, an unexpected result. The initial stage of Florida triggered lightning typically transitions from vertical to horizontal propagation at altitudes of 3-6 km, near the typical 0 C level of 4-5 km and several kilometers below the expected center of the negative cloud-charge region at 7-8 km. The data presented potentially provide information on thunderstorm electrical and hydrometeor structure and discharge propagation physics. LMA source locations were obtained from VHF sources of positive impulsive currents as small as 10 A, in contrast to expectations found in the literature

    Generic Model Refactorings

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    Many modeling languages share some common concepts and principles. For example, Java, MOF, and UML share some aspects of the concepts\ud of classes, methods, attributes, and inheritance. However, model\ud transformations such as refactorings specified for a given language\ud cannot be readily reused for another language because their related\ud metamodels may be structurally different. Our aim is to enable a\ud flexible reuse of model transformations across various metamodels.\ud Thus, in this paper, we present an approach allowing the specification\ud of generic model transformations, in particular refactorings, so\ud that they can be applied to different metamodels. Our approach relies\ud on two mechanisms: (1) an adaptation based mainly on the weaving\ud of aspects; (2) the notion of model typing, an extension of object\ud typing in the model-oriented context. We validated our approach by\ud performing some experiments that consisted of specifying three well\ud known refactorings (Encapsulate Field, Move Method, and Pull Up Method)\ud and applying each of them onto three different metamodels (Java,\ud MOF, and UML)
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