WorldWideScience

Sample records for strong diurnal cycle

  1. Diurnal cloud cycle biases in climate models.

    Science.gov (United States)

    Yin, Jun; Porporato, Amilcare

    2017-12-22

    Clouds' efficiency at reflecting solar radiation and trapping the terrestrial radiation is strongly modulated by the diurnal cycle of clouds (DCC). Much attention has been paid to mean cloud properties due to their critical role in climate projections; however, less research has been devoted to the DCC. Here we quantify the mean, amplitude, and phase of the DCC in climate models and compare them with satellite observations and reanalysis data. While the mean appears to be reliable, the amplitude and phase of the DCC show marked inconsistencies, inducing overestimation of radiation in most climate models. In some models, DCC appears slightly shifted over the ocean, likely as a result of tuning and fortuitously compensating the large DCC errors over the land. While this model tuning does not seem to invalidate climate projections because of the limited DCC response to global warming, it may potentially increase the uncertainty of climate predictions.

  2. Modelling of diurnal cycle under climate change

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, A.V.; Bezmenov, K.V.; Demchenko, P.F.; Mokhov, I.I.; Petoukhov, V.K. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Atmospheric Physics

    1995-12-31

    The observed diurnal temperature range (DTR) displays remarkable change during last 30 years. Land air DTR generally decreases under global climate warming due to more significant night minimum temperature increase in comparison with day maximum temperature increase. Atmosphere hydrological cycle characteristics change under global warming and possible background aerosol atmosphere content change may cause essential errors in the estimation of DTR tendencies of change under global warming. The result of this study is the investigation of cloudiness effect on the DTR and blackbody radiative emissivity diurnal range. It is shown that in some cases (particularly in cold seasons) it results in opposite change in DTR and BD at doubled CO{sub 2} atmosphere content. The influence of background aerosol is the same as the cloudiness one

  3. Tropical Cyclone Diurnal Cycle as Observed by TRMM

    Science.gov (United States)

    Leppert, Kenneth D., II; Cecil, D. J.

    2015-01-01

    to frictional convergence) may disrupt the natural convective cycle of a cyclone. Hence, only data pertaining to storms whose centers were greater than 300 km from land were included in the composites. Early results suggest the presence of a diurnal cycle in the PR composites of all Atlantic basin tropical cyclones from a height of 2-12 km from approximately 0-400 km radius, but the cycle is most apparent above 6 km. At a height of 8 km, there is a peak (minimum) in the percentage of PR pixels greater than or equal to 20 dBZ near 0 (21) LST in the inner core with some indication that this signal propagates outward with time. In contrast, the 37- and 85-GHz composites show little indication of a diurnal cycle at any radii, regardless of the threshold used. Ongoing work with this project will involve sub-setting the composites according to storm intensity to see if the diurnal cycle varies with storm strength. Moderate to strong vertical wind shear often leads to asymmetries in tropical cyclone convection and may disrupt the cyclone's natural diurnal cycle. Therefore, wind shear thresholds will be applied to the composites to determine if the diurnal cycle becomes more apparent in a low shear environment. Finally, other work to be completed will involve developing composites for other tropical cyclone basins, including the East Pacific, Northwest Pacific, South Pacific, and Indian Ocean.

  4. Evaluating the diurnal cycle in cloud top temperature from SEVIRI

    Science.gov (United States)

    Taylor, Sarah; Stier, Philip; White, Bethan; Finkensieper, Stephan; Stengel, Martin

    2017-06-01

    The variability of convective cloud spans a wide range of temporal and spatial scales and is of fundamental importance for global weather and climate systems. Datasets from geostationary satellite instruments such as the Spinning Enhanced Visible and Infrared Imager (SEVIRI) provide high-time-resolution observations across a large area. In this study we use data from SEVIRI to quantify the diurnal cycle of cloud top temperature within the instrument's field of view and discuss these results in relation to retrieval biases. We evaluate SEVIRI cloud top temperatures from the new CLAAS-2 (CLoud property dAtAset using SEVIRI, Edition 2) dataset against Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data. Results show a mean bias of +0.44 K with a standard deviation of 11.7 K, which is in agreement with previous validation studies. Analysis of the spatio-temporal distribution of these errors shows that absolute retrieval biases vary from less than 5 K over the southeast Atlantic Ocean up to 30 K over central Africa at night. Night- and daytime retrieval biases can also differ by up to 30 K in some areas, potentially contributing to biases in the estimated amplitude of the diurnal cycle. This illustrates the importance of considering spatial and diurnal variations in retrieval errors when using the CLAAS-2 dataset. Keeping these biases in mind, we quantify the seasonal, diurnal, and spatial variation of cloud top temperature across SEVIRI's field of view using the CLAAS-2 dataset. By comparing the mean diurnal cycle of cloud top temperature with the retrieval bias, we find that diurnal variations in the retrieval bias can be small but are often of the same order of magnitude as the amplitude of the observed diurnal cycle, indicating that in some regions the diurnal cycle apparent in the observations may be significantly impacted by diurnal variability in the accuracy of the retrieval. We show that the CLAAS-2 dataset can measure the diurnal cycle of cloud tops

  5. Characterisation and quantification of regional diurnal SST cycles from SEVIRI

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, J.L.

    2014-01-01

    Hourly SST (sea surface temperature) fields from the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) offer a unique opportunity for the characterisation and quantification of the diurnal cycle of SST in the Atlantic Ocean, the Mediterranean Sea and the northern European shelf....... The different methodologies tested for the foundation temperature fields reveal variability introduced by averaging night-time SSTs over many days compared to single-day, pre-dawn values. Diurnal warming is most pronounced in the Mediterranean and Baltic seas while weaker diurnal signals are found...... in the tropics. Longer diurnal warming duration is identified in the high latitudes compared to the tropics. The maximum monthly mean diurnal signal can be up to 0.5K in specific regions....

  6. Robust fitting of diurnal brightness temperature cycle

    CSIR Research Space (South Africa)

    Udahemuka, G

    2007-11-01

    Full Text Available . In this paper, diurnal brightness temperatures received from the METEOSAT Second Generation (MSG) satellite were interpolated for missing data based on a model, and a performance test was performed by comparing a new approach based on robust modelling...

  7. Annual Climatology of the Diurnal Cycle on the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    Alan K Betts

    2016-01-01

    Full Text Available We show the annual climatology of the diurnal cycle, stratified by opaque cloud, using the full hourly resolution of the Canadian Prairie data. The opaque cloud field itself has distinct cold and warm season diurnal climatologies; with a near-sunrise peak of cloud in the cold season and an early afternoon peak in the warm season. There are two primary climate states on the Canadian Prairies, separated by the freezing point of water, because a reflective surface snow cover acts as a climate switch. Both cold and warm season climatologies can be seen in the transition months of November, March and April with a large difference in mean temperature. In the cold season with snow, the diurnal ranges of temperature and relative humidity increase quasi-linearly with decreasing cloud, and increase from December to March with increased solar forcing. The warm season months, April to September, show a homogeneous coupling to the cloud cover, and a diurnal cycle of temperature and humidity that depends only on net longwave. Our improved representation of the diurnal cycle shows that the warm season coupling between diurnal temperature range and net longwave is weakly quadratic through the origin, rather than the linear coupling shown in earlier papers. We calculate the conceptually important 24-h imbalances of temperature and relative humidity (and other thermodynamic variables as a function of opaque cloud cover. In the warm season under nearly clear skies, there is a warming of +2oC and a drying of -6% over the 24-h cycle, which is about 12% of their diurnal ranges. We summarize results on conserved variable diagrams and explore the impact of surface windspeed on the diurnal cycle in the cold and warm seasons. In all months, the fall in minimum temperature is reduced with increasing windspeed, which reduces the diurnal temperature range. In July and August, there is an increase of afternoon maximum temperature and humidity at low windspeeds, and a

  8. Variability of radiatively forced diurnal cycle of intense convection in the tropical west pacific

    Energy Technology Data Exchange (ETDEWEB)

    Gray, W.M.; Sheaffer, J.D.; Thorson, W.B. [Colorado State Univ., Fort Collins, CO (United States)

    1996-04-01

    Strong differences occur in daytime versus nighttime (DVN) net radiative cooling in clear versus cloudy areas of the tropical atmosphere. Daytime average cooling is approximately -0.7{degrees}C/day, whereas nighttime net tropospheric cooling rates are about -1.5{degrees}C/day, an approximately two-to-one difference. The comparatively strong nocturnal cooling in clear areas gives rise to a diurnally varying vertical circulation and horizontal convergence cycle. Various manifestations of this cyclic process include the observed early morning heavy rainfall maxima over the tropical oceans. The radiatively driven DVN circulation appears to strongly modulate the resulting diurnal cycle of intense convection which creates the highest, coldest cloudiness over maritime tropical areas and is likely a fundamental mechanism governing both small and large scale dynamics over much of the tropical environment.

  9. Diurnal cycles in water quality across the periodic table

    Science.gov (United States)

    Kirchner, James

    2014-05-01

    Diurnal cycles in water quality can provide important clues to the processes that regulate aquatic chemistry, but they often are masked by longer-term, larger-amplitude variability, making their detection and quantification difficult. Here I outline methods that can detect diurnal cycles even when they are massively obscured by statistically ill-behaved noise. I demonstrate these methods using high-frequency water quality data from the Plylimon catchment in mid-Wales (Neal et al., 2013; Kirchner and Neal, 2013). Several aspects combine to make the Plynlimon data set unique worldwide. Collected at 7-hour intervals, the Plynlimon data set is much more densely sampled than typical long-term weekly or monthly water quality data. This 7-hour sampling was also continued for two years, much longer than typical intensive sampling campaigns, and the resulting time series encompass a wide range of climatic and hydrological conditions. Furthermore, each sample was analyzed for a wide range of solutes with diverse sources in the natural environment. However, the 7-hour sampling frequency is both coarse and irregular in comparison to diurnal cycles, making their detection and quantification difficult. Nonetheless, the methods outlined here enable detection of statistically significant diurnal cycles in over 30 solutes at Plynlimon, including alkali metals (Li, Na, K, Rb, and Cs), alkaline earths (Be, Mg, Ca, Sr, and Ba), transition metals (Al, Ti, Mn, Fe, Co, Ni, Zn, Mo, Cd, and Pb), nonmetals (B, NO3, Si, As, and Se), lanthanides and actinides (La, Ce, Pr, and U), as well as total dissolved nitrogen (TDN), dissolved organic carbon (DOC), Gran alkalinity, pH, and electrical conductivity. These solutes span every row of the periodic table, and more than six orders of magnitude in concentration. Many of these diurnal cycles are subtle, representing only a few percent, at most, of the total variance in the concentration time series. Nonetheless they are diagnostically useful

  10. Deep greedy learning under thermal variability in full diurnal cycles

    Science.gov (United States)

    Rauss, Patrick; Rosario, Dalton

    2017-08-01

    We study the generalization and scalability behavior of a deep belief network (DBN) applied to a challenging long-wave infrared hyperspectral dataset, consisting of radiance from several manmade and natural materials within a fixed site located 500 m from an observation tower. The collections cover multiple full diurnal cycles and include different atmospheric conditions. Using complementary priors, a DBN uses a greedy algorithm that can learn deep, directed belief networks one layer at a time and has two layers form to provide undirected associative memory. The greedy algorithm initializes a slower learning procedure, which fine-tunes the weights, using a contrastive version of the wake-sleep algorithm. After fine-tuning, a network with three hidden layers forms a very good generative model of the joint distribution of spectral data and their labels, despite significant data variability between and within classes due to environmental and temperature variation occurring within and between full diurnal cycles. We argue, however, that more questions than answers are raised regarding the generalization capacity of these deep nets through experiments aimed at investigating their training and augmented learning behavior.

  11. Seasonal variations in the lightning diurnal cycle and implications for the global electric circuit

    Science.gov (United States)

    Blakeslee, Richard J.; Mach, Douglas M.; Bateman, Monte G.; Bailey, Jeffrey C.

    2014-01-01

    Data obtained from the Optical Transient Detector and the Lightning Imaging Sensor satellites (70° and 35° inclination low earth orbits, respectively) are used to statistically determine the number of flashes in the seasonal diurnal cycle as a function of local and universal time. These data include corrections for detection efficiency and instrument view time. They are further subdivided by season, land versus ocean, and other spatial (e.g., continents) and temporal (e.g., time of peak diurnal amplitude) categories. These statistics are then combined with analyses of high altitude aircraft observations of electrified clouds to produce the seasonal diurnal variation in the global electric circuit. Continental results display strong diurnal variation, with a lightning peak in the late afternoon and a minimum in late morning. In geographical regions dominated by large mesoscale convective systems, the peak in the diurnal curve shifts toward late evening or early morning hours. The maximum seasonal diurnal flash rate occurs in June-August, corresponding to the Northern Hemisphere summer, while the minimum occurs in December-February. Summer lightning dominates over winter activity and springtime lightning dominates over fall activity at most continental locations. Oceanic lightning exhibits minimal diurnal variation, but morning hours are slightly enhanced over afternoon. As was found earlier, for the annual diurnal variation, using basic assumptions about the mean storm currents as a function of flash rate and location (i.e., land/ocean), our seasonal estimates of the current in the global electric circuit provide an excellent match with independent measurements of the seasonal Carnegie curve diurnal variations. The maximum (minimum) total mean current of 2.4 kA (1.7 kA) is found during Northern Hemisphere summer (winter). Land thunderstorms supply about one half (52%) of the total global current. Ocean thunderstorms contribute about one third (31%) and the non

  12. Cumulus moistening, the diurnal cycle, and large-scale tropical dynamics

    Science.gov (United States)

    Ruppert, James H., Jr.

    Observations and modeling techniques are employed to diagnose the importance of the diurnal cycle in large-scale tropical climate. In the first part of the study, soundings, radar, and surface flux measurements collected in the Indian Ocean DYNAMO experiment (Dynamics of the Madden--Julian Oscillation, or MJO) are employed to study MJO convective onset. According to these observations, MJO onset takes place as follows: moistening of the low--midtroposphere is accomplished by cumuliform clouds that deepen as the drying by large-scale subsidence and horizontal advection simultaneously wane. This relaxing of subsidence is tied to decreasing column radiative cooling, which links back to the evolving cloud population. A new finding from these observations is the high degree to which the diurnal cycle linked to air-sea and radiative fluxes invigorates clouds and drives column moistening each day. This diurnally modulated cloud field exhibits pronounced mesoscale organization in the form of open cells and horizontal convective rolls. Based on these findings, it is hypothesized that the diurnal cycle and mesoscale cloud organization represent two manners in which local convective processes promote more vigorous day-to-day tropospheric moistening than would otherwise occur. A suite of model tests are carried out in the second part of the study to 1) test the hypothesis that the diurnal cycle drives moistening on longer timescales, and 2) better understand the relative roles of diurnally varying sea surface temperature (SST) and direct atmospheric radiative heating in the diurnal cycle of convection. Moist convection is explicitly represented in the model, the diurnal cycle of SST is prescribed, and cloud-interactive radiation is simulated with a diurnal cycle in shortwave heating. The large-scale dynamics are parameterized using the spectral weak temperature gradient (WTG) technique recently introduced by Herman and Raymond. In this scheme, external (i.e., large

  13. Satellite, climatological, and theoretical inputs for modeling of the diurnal cycle of fire emissions

    Science.gov (United States)

    Hyer, E. J.; Reid, J. S.; Schmidt, C. C.; Giglio, L.; Prins, E.

    2009-12-01

    The diurnal cycle of fire activity is crucial for accurate simulation of atmospheric effects of fire emissions, especially at finer spatial and temporal scales. Estimating diurnal variability in emissions is also a critical problem for construction of emissions estimates from multiple sensors with variable coverage patterns. An optimal diurnal emissions estimate will use as much information as possible from satellite fire observations, compensate known biases in those observations, and use detailed theoretical models of the diurnal cycle to fill in missing information. As part of ongoing improvements to the Fire Location and Monitoring of Burning Emissions (FLAMBE) fire monitoring system, we evaluated several different methods of integrating observations with different temporal sampling. We used geostationary fire detections from WF_ABBA, fire detection data from MODIS, empirical diurnal cycles from TRMM, and simple theoretical diurnal curves based on surface heating. Our experiments integrated these data in different combinations to estimate the diurnal cycles of emissions for each location and time. Hourly emissions estimates derived using these methods were tested using an aerosol transport model. We present results of this comparison, and discuss the implications of our results for the broader problem of multi-sensor data fusion in fire emissions modeling.

  14. Mesoscale Influences of Wind Farms Throughout a Diurnal Cycle

    Science.gov (United States)

    Fitch, A. C.; Lundquist, J. K.; Olson, J. B.

    2012-12-01

    Few observations are available to give insight into the interaction between large wind farms and the boundary layer. As wind farm deployment increases, questions are arising on the potential impact on meteorology within and downwind of large wind farms. While large-eddy simulation can provide insight into the detailed interaction between individual turbines and the boundary layer, to date it has been too computationally expensive to simulate wind farms with large numbers of turbines and the resulting wake far downstream. Mesoscale numerical weather prediction models provide the opportunity to investigate the flow in and around large wind farms as a whole, and the resulting impact on meteorology. To this end, we have implemented a wind farm parameterization in the Weather Research and Forecasting (WRF) model, which represents wind turbines by imposing a momentum sink on the mean flow; converting kinetic energy into electricity and turbulent kinetic energy (TKE). The parameterization improves upon previous models, basing the atmospheric drag of turbines on the thrust coefficient of a modern commercial turbine. In addition, the source of TKE varies with wind speed, reflecting the amount of energy extracted from the atmosphere by the turbines that does not produce electrical energy. We simulate a wind farm covering 10x10 km over land, consisting of 100 turbines each of nominal power output of 5 MW. Results will be presented showing how the wake structure varies dramatically over a diurnal cycle characteristic of a region in the Great Plains of the US, where wind farm deployment is planned. At night, a low-level jet forms within the rotor area, which is completely eliminated by energy extraction within the wind farm. The deep stable layer and lack of higher momentum air aloft at this time maximises the wind deficit and the length of the wake. The presentation will discuss the maximum reduction of wind speed within and downwind from the farm, and the wake e

  15. Inter-comparison of satellite rainfall products for representing rainfall diurnal cycle over the Nile basin

    NARCIS (Netherlands)

    Haile, A.T.; Haile, Alemseged Tamiru; Habib, Emad; Elsaadani, Mohamed; Rientjes, T.H.M.

    2013-01-01

    In this study, the authors inter-compared the performance of three satellite-rainfall products in representing the diurnal cycle of rain occurrence and rain rate over the Nile basin in eastern Africa. These products are the real time (RT) and post-real-time (PRT) (bias adjusted) versions of Tropical

  16. Radial frequency diagram (sunflower) for the analysis of diurnal cycle parameters: Solar energy application

    International Nuclear Information System (INIS)

    Božnar, Marija Zlata; Grašič, Boštjan; Mlakar, Primož; Soares, Jacyra; Pereira de Oliveira, Amauri; Costa, Tássio Santos

    2015-01-01

    Graphical abstract: A new type of graphical presentation showing diurnal cycle of solar energy forecast. The application is possible for other parameters related to weather and green energy production. - Highlights: • The diurnal cycle of solar energy is important for the management of the electrical grid. • A solar plant’s average production depends on the statistical features of solar radiation. • The new tool – the “sunflower”, is proposed for solar energy availability representation. • The sunflower identifies and quantifies information with a clear diurnal cycle. • The sunflower diagram has been developed from the “wind rose” diagram. - Abstract: Many meteorological parameters present a natural diurnal cycle because they are directly or indirectly dependent on sunshine exposure. The solar radiation diurnal pattern is important to energy production, agriculture, prognostic models, health and general climatology. This article aims at introducing a new type of radial frequency diagram – hereafter called sunflower – for the analysis of solar radiation data in connection with energy production and also for climatological studies. The diagram is based on two-dimensional data sorting. Firstly data are sorted into classes representing hours in a day. Then the data in each hourly class is sorted into classes of the observed variable values. The relative frequencies of the value classes are shown as sections on each hour’s segment in a radial diagram. The radial diagram forms a unique pattern for each analysed dataset. Therefore it enables the quick detection of features and the comparison of several such patterns belonging to the different datasets being analysed. The sunflower diagram enables a quick and comprehensive understanding of the information about diurnal cycle of the solar radiation data. It enables in a graphical form, quick screening and long-term statistics of huge data quantities when searching for their diurnal features and

  17. Impact of the Diurnal Cycle of the Atmospheric Boundary Layer on Wind-Turbine Wakes: A Numerical Modelling Study

    Science.gov (United States)

    Englberger, Antonia; Dörnbrack, Andreas

    2018-03-01

    The wake characteristics of a wind turbine for different regimes occurring throughout the diurnal cycle are investigated systematically by means of large-eddy simulation. Idealized diurnal cycle simulations of the atmospheric boundary layer are performed with the geophysical flow solver EULAG over both homogeneous and heterogeneous terrain. Under homogeneous conditions, the diurnal cycle significantly affects the low-level wind shear and atmospheric turbulence. A strong vertical wind shear and veering with height occur in the nocturnal stable boundary layer and in the morning boundary layer, whereas atmospheric turbulence is much larger in the convective boundary layer and in the evening boundary layer. The increased shear under heterogeneous conditions changes these wind characteristics, counteracting the formation of the night-time Ekman spiral. The convective, stable, evening, and morning regimes of the atmospheric boundary layer over a homogeneous surface as well as the convective and stable regimes over a heterogeneous surface are used to study the flow in a wind-turbine wake. Synchronized turbulent inflow data from the idealized atmospheric boundary-layer simulations with periodic horizontal boundary conditions are applied to the wind-turbine simulations with open streamwise boundary conditions. The resulting wake is strongly influenced by the stability of the atmosphere. In both cases, the flow in the wake recovers more rapidly under convective conditions during the day than under stable conditions at night. The simulated wakes produced for the night-time situation completely differ between heterogeneous and homogeneous surface conditions. The wake characteristics of the transitional periods are influenced by the flow regime prior to the transition. Furthermore, there are different wake deflections over the height of the rotor, which reflect the incoming wind direction.

  18. On the influence of cloud fraction diurnal cycle and sub-grid cloud optical thickness variability on all-sky direct aerosol radiative forcing

    International Nuclear Information System (INIS)

    Min, Min; Zhang, Zhibo

    2014-01-01

    The objective of this study is to understand how cloud fraction diurnal cycle and sub-grid cloud optical thickness variability influence the all-sky direct aerosol radiative forcing (DARF). We focus on the southeast Atlantic region where transported smoke is often observed above low-level water clouds during burning seasons. We use the CALIOP observations to derive the optical properties of aerosols. We developed two diurnal cloud fraction variation models. One is based on sinusoidal fitting of MODIS observations from Terra and Aqua satellites. The other is based on high-temporal frequency diurnal cloud fraction observations from SEVIRI on board of geostationary satellite. Both models indicate a strong cloud fraction diurnal cycle over the southeast Atlantic region. Sensitivity studies indicate that using a constant cloud fraction corresponding to Aqua local equatorial crossing time (1:30 PM) generally leads to an underestimated (less positive) diurnal mean DARF even if solar diurnal variation is considered. Using cloud fraction corresponding to Terra local equatorial crossing time (10:30 AM) generally leads overestimation. The biases are a typically around 10–20%, but up to more than 50%. The influence of sub-grid cloud optical thickness variability on DARF is studied utilizing the cloud optical thickness histogram available in MODIS Level-3 daily data. Similar to previous studies, we found the above-cloud smoke in the southeast Atlantic region has a strong warming effect at the top of the atmosphere. However, because of the plane-parallel albedo bias the warming effect of above-cloud smoke could be significantly overestimated if the grid-mean, instead of the full histogram, of cloud optical thickness is used in the computation. This bias generally increases with increasing above-cloud aerosol optical thickness and sub-grid cloud optical thickness inhomogeneity. Our results suggest that the cloud diurnal cycle and sub-grid cloud variability are important factors

  19. Seasonal Cycle of the Near-Surface Diurnal Wind Field Over the Bay of La Paz, Mexico

    Science.gov (United States)

    Turrent, Cuauhtémoc; Zaitsev, Oleg

    2014-05-01

    The results of numerical simulations of the troposphere over the Bay of La Paz, calculated for the months of January, April, July and October during the period 2006-2010 with the Weather Research and Forecast (WRF v3.5) regional model, are used to describe the seasonal features of the diurnal cycle of planetary boundary-layer winds. Two distinct near-surface diurnal flows with strong seasonal variability were identified: (1) a nocturnal and matutinal breeze directed from the subtropical Pacific Ocean, over the Baja California peninsula and the Bay of La Paz, into the Gulf of California that is associated with the regional sea-surface temperature difference between those two major water bodies; and (2) a mid to late afternoon onshore sea-breeze related to the peninsula's daily cycle of insolation heating that evolves with counter-clockwise rotation over the Bay of La Paz. The model results reveal the interaction over Baja California of opposing afternoon sea-breeze fronts that originate from the subtropical Pacific Ocean and the Gulf of California, with a convergence line forming over the peaks of the peninsula's topography and the associated presence of a closed vertical circulation cell over the Bay of La Paz and the adjacent Gulf. The collision of the opposing sea-breeze fronts over the narrow peninsula drives convection that is relatively weak due to the reduced heat source and only appears to produce precipitation sporadically. The spatial structure of the sea-breeze fronts over the Bay of La Paz region is complex due to shoreline curvature and nearby topographic features. A comparison of the numerical results with available meteorological near-surface observations indicates that the modelling methodology adequately reproduced the observed features of the seasonal variability of the local planetary boundary-layer diurnal wind cycle and confirms that the low-level atmospheric circulation over the Bay of La Paz is dominated by kinetic energy in the diurnal band

  20. Large Eddy Simulation of the Diurnal Cycle in Southeast Pacific Stratocumulus

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, P; Bretherton, C

    2008-03-03

    This paper describes a series of 6 day large eddy simulations of a deep, sometimes drizzling stratocumulus-topped boundary layer based on forcings from the East Pacific Investigation of Climate (EPIC) 2001 field campaign. The base simulation was found to reproduce the observed mean boundary layer properties quite well. The diurnal cycle of liquid water path was also well captured, although good agreement appears to result partially from compensating errors in the diurnal cycles of cloud base and cloud top due to overentrainment around midday. At other times of the day, entrainment is found to be proportional to the vertically-integrated buoyancy flux. Model stratification matches observations well; turbulence profiles suggest that the boundary layer is always at least somewhat decoupled. Model drizzle appears to be too sensitive to liquid water path and subcloud evaporation appears to be too weak. Removing the diurnal cycle of subsidence had little effect on simulated cloud albedo. Simulations with changed droplet concentration and drizzle susceptibility showed large liquid water path differences at night, but differences were quite small at midday. Droplet concentration also had a significant impact on entrainment, primarily through droplet sedimentation feedback rather than through drizzle processes.

  1. Target Detection over the Diurnal Cycle Using a Multispectral Infrared Sensor

    Directory of Open Access Journals (Sweden)

    Huijie Zhao

    2016-12-01

    Full Text Available When detecting a target over the diurnal cycle, a conventional infrared thermal sensor might lose the target due to the thermal crossover, which could happen at any time throughout the day when the infrared image contrast between target and background in a scene is indistinguishable due to the temperature variation. In this paper, the benefits of using a multispectral-based infrared sensor over the diurnal cycle have been shown. Firstly, a brief theoretical analysis on how the thermal crossover influences a conventional thermal sensor, within the conditions where the thermal crossover would happen and why the mid-infrared (3~5 μm multispectral technology is effective, is presented. Furthermore, the effectiveness of this technology is also described and we describe how the prototype design and multispectral technology is employed to help solve the thermal crossover detection problem. Thirdly, several targets are set up outside and imaged in the field experiment over a 24-h period. The experimental results show that the multispectral infrared imaging system can enhance the contrast of the detected images and effectively solve the failure of the conventional infrared sensor during the diurnal cycle, which is of great significance for infrared surveillance applications.

  2. Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site

    Science.gov (United States)

    Zhao, W.; Marchand, R.; Fu, Q.

    2016-12-01

    Millimeter Wavelength Cloud Radar (MMCR) data from Dec. 1996 to Dec. 2010, collected at the U. S. Department of Energy Atmospheric Radiation Measurement (ARM) program site in the U.S. Southern Great Plains (SGP), are categorized into clouds (-40dBZe≤reflectivityCRM). Observational and simulated radar reflectivity are compared and further sorted into different atmospheric states identified by Evans (2014). Evans used a neutral network to take ERA-Interim state variables (i.e. horizontal winds, relative humidity, temperature at seven predetermined pressure level and surface pressure) on an 8×8 grid with 1.5º×1.5º spatial resolution centered on the SGP site and found twenty-one atmospheric states which represent specific synoptic conditions. We use these states to study the differences in the diurnal cycle between observations and simulations. Differences in the (mean) annual diurnal cycle between the observations and model are decomposed into errors in the daily mean, errors in the diurnal variation in each state, and errors due to difference in the frequency of occurrence of atmospheric states between ERA and the MMF. The magnitude of various error sources is assessed.

  3. Modeling and Simulation of Optimal Resource Management during the Diurnal Cycle in Emiliania huxleyi by Genome-Scale Reconstruction and an Extended Flux Balance Analysis Approach.

    Science.gov (United States)

    Knies, David; Wittmüß, Philipp; Appel, Sebastian; Sawodny, Oliver; Ederer, Michael; Feuer, Ronny

    2015-10-28

    The coccolithophorid unicellular alga Emiliania huxleyi is known to form large blooms, which have a strong effect on the marine carbon cycle. As a photosynthetic organism, it is subjected to a circadian rhythm due to the changing light conditions throughout the day. For a better understanding of the metabolic processes under these periodically-changing environmental conditions, a genome-scale model based on a genome reconstruction of the E. huxleyi strain CCMP 1516 was created. It comprises 410 reactions and 363 metabolites. Biomass composition is variable based on the differentiation into functional biomass components and storage metabolites. The model is analyzed with a flux balance analysis approach called diurnal flux balance analysis (diuFBA) that was designed for organisms with a circadian rhythm. It allows storage metabolites to accumulate or be consumed over the diurnal cycle, while keeping the structure of a classical FBA problem. A feature of this approach is that the production and consumption of storage metabolites is not defined externally via the biomass composition, but the result of optimal resource management adapted to the diurnally-changing environmental conditions. The model in combination with this approach is able to simulate the variable biomass composition during the diurnal cycle in proximity to literature data.

  4. Influence of observed diurnal cycles of aerosol optical depth on aerosol direct radiative effect

    Directory of Open Access Journals (Sweden)

    A. Arola

    2013-08-01

    Full Text Available The diurnal variability of aerosol optical depth (AOD can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF or aerosol direct radiative effect (ADRE. The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally. We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on

  5. Diurnal cycle of the dust instantaneous direct radiative forcing over the Arabian Peninsula

    KAUST Repository

    Osipov, Sergey

    2015-08-27

    In this study we attempted to better quantify radiative effects of dust over the Arabian Peninsula and their dependence on input parameters. For this purpose we have developed a stand-alone column radiation transport model coupled with the Mie, T-matrix and geometric optics calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments were carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18–20 March 2012. Comprehensive ground-based observations and satellite retrievals were used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing were estimated both from the model and observations. Diurnal cycle of the shortwave instantaneous dust direct radiative forcing was studied for a range of aerosol and surface characteristics representative of the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing were evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions, along with anisotropic aerosol scattering, are mostly responsible for diurnal effects.

  6. Covariability in the Monthly Mean Convective and Radiative Diurnal Cycles in the Amazon

    Science.gov (United States)

    Dodson, Jason B.; Taylor, Patrick C.

    2015-01-01

    The diurnal cycle of convective clouds greatly influences the radiative energy balance in convectively active regions of Earth, through both direct presence, and the production of anvil and stratiform clouds. Previous studies show that the frequency and properties of convective clouds can vary on monthly timescales as a result of variability in the monthly mean atmospheric state. Furthermore, the radiative budget in convectively active regions also varies by up to 7 Wm-2 in convectively active regions. These facts suggest that convective clouds connect atmospheric state variability and radiation variability beyond clear sky effects alone. Previous research has identified monthly covariability between the diurnal cycle of CERES-observed top-of-atmosphere radiative fluxes and multiple atmospheric state variables from reanalysis over the Amazon region. ASVs that enhance (reduce) deep convection, such as CAPE (LTS), tend to shift the daily OLR and cloud albedo maxima earlier (later) in the day by 2-3 hr. We first test the analysis method using multiple reanalysis products for both the dry and wet seasons to further investigate the robustness of the preliminary results. We then use CloudSat data as an independent cloud observing system to further evaluate the relationships of cloud properties to variability in radiation and atmospheric states. While CERES can decompose OLR variability into clear sky and cloud effects, it cannot determine what variability in cloud properties lead to variability in the radiative cloud effects. Cloud frequency, cloud top height, and cloud microphysics all contribute to the cloud radiative effect, all of which are observable by CloudSat. In addition, CloudSat can also observe the presence and variability of deep convective cores responsible for the production of anvil clouds. We use these capabilities to determine the covariability of convective cloud properties and the radiative diurnal cycle.

  7. Effect of programmed diurnal temperature cycles on plasma thyroxine level, body temperature, and feed intake of holstein dairy cows

    Science.gov (United States)

    Scott, I. M.; Johnson, H. D.; Hahn, G. L.

    1983-03-01

    Holstein cows exposed to simulated summer diurnal ambient temperature cycles of Phoenix, Arizona and Atlanta, Georgia and diurnal modifications of these climates displayed daily cycles fluctuations in plasma thyroxine (T4) and rectal temperatures (Tre). There were daily diurnal changes in T4 and Tre under all simulated climate conditions. Maximal values generally occurred in the evening hours and minimum values in the morning. Although the diurnal rhythm was influenced by the various simulated climates (diurnal modifications) a diurnal rhythm was very evident even under constant conditions at thermoneutral (Tnc) and at cyclic thermoneutral conditions (TN). The major significance of the study is that the initiation of night cooling of the animals at a time when their Tre was highest was most beneficial to maintenance of a TN plasma T4 level. There was a highly significant negative relationship of average T4 and average Tre. There was also a significant negative relationship of feed consumption and average temperature-humidity index (THI). These data suggest that night cooling may be a most effective method to alleviate thermoregulatory limitations of a hot climate on optimal animal performance. Decreasing the night time air temperature (Ta) or THI or increasing the diurnal range allows the cows to more easily dissipate excess body heat accumulated during the day and minimize the thermal inhibition on feed intake, and alterations in plasma T4 and Tre.

  8. Dust emissions in the West African heat trough. The role of the diurnal cycle and of extratropical disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Knippertz, P. [Inst. fuer Physik der Atmosphaere, Johannes Gutenberg-Univ. Mainz (Germany)

    2008-10-15

    The summertime West African heat trough (HT) is one of the most active dust sources in the world. A detailed case study during May/June 2006 based upon analyses from the European Centre for Medium-Range Weather Forecasts and a new Meteosat dust product illustrates two important mechanisms of dust emissions in this region: (1) The dry continental-scale HT circulation exhibits a strong diurnal cycle characterized by nocturnal low-level jets and downward mixing of momentum to the surface during the build-up of the planetary boundary layer in the morning. This leads to strong gusty surface winds and dust emission, mostly along the northern side of the HT, but also within the southerly monsoon flow. Transports lead to an accumulation of dust near the axis of the HT. (2) Triggered by a lee cyclogenesis south of the Atlas Mountains, the Intertropical Discontinuity that separates dry Saharan and moist monsoonal air shifts northward and allows deep moist convection to penetrate into the Sahara. The evaporation of precipitation in the dry desert air also generates strong gusty winds and dust emissions. This study helps to clarify the physical mechanisms for a previously discovered relation between the annual cycles of dustiness on one hand and near-surface convergence and gustiness on the other hand. (orig.)

  9. A One-Year Study of the Diurnal Cycle of Meteorology, Clouds, and Radiation in the West African Sahel Region

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt-Collow, Allison; Ghate, Virendra P.; Miller, Mark A.; Trabachino, Lynne

    2016-01-09

    The diurnal cycles of meteorological and radiation variables are analyzed during the wet and dry seasons over the Sahel region of West Africa during 2006 using surface data collected by the Atmospheric Radiation Measurement (ARM) program’s Mobile Facility, satellite radiation measurements from the Geostationary Earth Radiation Budget (GERB) instrument aboard Meteosat 8, and reanalysis products from the National Center for Environmental Prediction (NCEP). The meteorological analysis builds upon past studies of the diurnal cycle in the region by incorporating diurnal cycles of lower tropospheric wind profiles, thermodynamic profiles, integrated water vapor and liquid water measurements, and cloud radar measurements of frequency and location. These meteorological measurements are complemented by 3-hour measurements of the diurnal cycles of the TOA and surface shortwave (SW) and longwave (LW) radiative fluxes and cloud radiative effects (CREs), and the atmospheric radiative flux divergence (RFD) and atmospheric CREs. Cirrus cloudiness during the dry season is shown to peak in coverage in the afternoon, while convective clouds during the wet season are shown to peak near dawn and have an afternoon minimum related to the rise of the Lifting Condensation Level into the Saharan Air Layer. The LW and SW RFDs and CREs exhibit diurnal cycles during both seasons, but there is a relatively small difference in the LW cycles during the two seasons (10-30 Wm^(-2) depending on the variable and time of day). Small differences in the TOA CREs during the two seasons are overwhelmed by large differences in the surface SW CREs, which exceed 100 Wm^(-2). A significant surface SW CRE during the wet season combined with a negligible TOA SW CRE produces a diurnal cycle in the atmospheric CRE that is modulated primarily by the SW surface CRE, peaks at midday at ~150 Wm^(-2), and varies widely from day to day.

  10. Diurnal Cycles of High Resolution Land Surface Temperatures (LSTs) Determined from UAV Platforms Across a Range of Surface Types

    Science.gov (United States)

    McCabe, M.; Rosas Aguilar, J.; Parkes, S. D.; Aragon, B.

    2017-12-01

    Observation of land surface temperature (LST) has many practical uses, from studying boundary layer dynamics and land-atmosphere coupling, to investigating surface properties such as soil moisture status, heat stress and surface heat fluxes. Typically, LST is observed via satellite based sensors such as LandSat or via point measurements using IR radiometers. These measurements provide either good spatial coverage and resolution or good temporal coverage. However, neither are able to provide the needed spatial and temporal resolution for many of the research applications described above. Technological developments in the use of Unmanned Aerial Vehicles (UAVs), together with small thermal frame cameras, has enabled a capacity to overcome this spatiotemporal constraint. Utilising UAV platforms to collect LST measurements across diurnal cycles provides an opportunity to study how meteorological and surface properties vary in both space and time. Here we describe the collection of LST data from a multi-rotor UAV across a study domain that is observed multiple times throughout the day. Flights over crops of Rhodes grass and alfalfa, along with a bare desert surface, were repeated with between 8 and 11 surveys covering the period from early morning to sunset. Analysis of the collected thermal imagery shows that the constructed LST maps illustrate a strong diurnal cycle consistent with expected trends, but with considerable spatial and temporal variability observed within and between the different domains. These results offer new insights into the dynamics of land surface behavior in both dry and wet soil conditions and at spatiotemporal scales that are unable to be replicated using traditional satellite platforms.

  11. Seasonal, Diurnal, and Solar-Cycle Variations of Electron Density at Two West Africa Equatorial Ionization Anomaly Stations

    Directory of Open Access Journals (Sweden)

    Frédéric Ouattara

    2012-01-01

    Full Text Available We analyse the variability of foF2 at two West Africa equatorial ionization anomaly stations (Ouagadougou and Dakar during three solar cycles (from cycle 20 to cycle 22, that is, from 1966 to 1998 for Ouagadougou and from 1971 to 1997 for Dakar. We examine the effect of the changing levels of solar extreme ultraviolet radiation with sunspot number. The study shows high correlation between foF2 and sunspot number (Rz. The correlation coefficient decreases from cycle 20 to cycle 21 at both stations. From cycle 21 to cycle 22 it decreases at Ouagadougou station and increases at Dakar station. The best correlation coefficient, 0.990, is obtained for Dakar station during solar cycle 22. The seasonal variation displays equinoctial peaks that are asymmetric between March and September. The percentage deviations of monthly average data from one solar cycle to another display variability with respect to solar cycle phase and show solar ultraviolet radiation variability with solar cycle phase. The diurnal variation shows a noon bite out with a predominant late-afternoon peak except during the maximum phase of the solar cycle. The diurnal Ouagadougou station foF2 data do not show a significant difference between the increasing and decreasing cycle phases, while Dakar station data do show it, particularly for cycle 21. The percentage deviations of diurnal variations from solar-minimum conditions show more ionosphere during solar cycle 21 at both stations for all three of the other phases of the solar cycle. There is no significant variability of ionosphere during increasing and decreasing solar cycle phases at Ouagadougou station, but at Dakar station there is a significant variability of ionosphere during these two solar-cycle phases.

  12. Study of Diurnal Cycle Variability of Planetary Boundary Layer Characteristics over the Red Sea and Arabian Peninsula

    KAUST Repository

    Li, Weigang

    2012-07-01

    This work is aimed at investigating diurnal cycle variability of the planetary boundary layer characteristics over the Arabian Peninsula and the Red Sea region. To fulfill this goal the downscaling simulations are performed using Weather Research and Forecasting (WRF) model. We analyze planetary boundary layer height, latent and sensible heat fluxes, and surface air temperature. The model results are compared with observations in different areas, for different seasons, and for different model resolutions. The model results are analyzed in order to better quantify the diurnal cycle variability over the Arabian Peninsula and the Red Sea. The specific features of this region are investigated and discussed.

  13. Evaluating the performance of ENVI-met model in diurnal cycles for different meteorological conditions

    Science.gov (United States)

    Acero, Juan A.; Arrizabalaga, Jon

    2018-01-01

    Urban areas are known to modify meteorological variables producing important differences in small spatial scales (i.e. microscale). These affect human thermal comfort conditions and the dispersion of pollutants, especially those emitted inside the urban area, which finally influence quality of life and the use of public open spaces. In this study, the diurnal evolution of meteorological variables measured in four urban spaces is compared with the results provided by ENVI-met (v 4.0). Measurements were carried out during 3 days with different meteorological conditions in Bilbao in the north of the Iberian Peninsula. The evaluation of the model accuracy (i.e. the degree to which modelled values approach measured values) was carried out with several quantitative difference metrics. The results for air temperature and humidity show a good agreement of measured and modelled values independently of the regional meteorological conditions. However, in the case of mean radiant temperature and wind speed, relevant differences are encountered highlighting the limitation of the model to estimate these meteorological variables precisely during diurnal cycles, in the considered evaluation conditions (sites and weather).

  14. On the Sensitivity of the Diurnal Cycle in the Amazon to Convective Intensity

    Science.gov (United States)

    Itterly, Kyle; Taylor, Patrick

    2015-01-01

    This presentation uses publicly available CERES and radiosonde data to investigate the sensitivity of thetropical convective diurnal cycle to atmosphere state. Averaging surface observations into regimes of convective intensitydefined by satellite shows great promise for physical understandingof convection.• Convective processes in the Amazon are highly variable seasonallyand locally.• Buoyancy/CIN more important JJA– Mesoscale/synoptic features easier to separate– Length/depth of buoyancy layer very important in DJF (EL).• Moisture more important DJF, esp. UTH– Humidity of lower atmosphere significantly impacts LTS, LCL and abilityfor parcels to reach LFC.• Lower level jet strength/direction important• Convective initiation correlated with LTS, LR, LTH, EL• Duration/Phase better correlated with humidity variables• Surface Flux amplitude well correlated with convection

  15. Application of numerical weather prediction in wind power forecasting: Assessment of the diurnal cycle

    Directory of Open Access Journals (Sweden)

    Tobias Heppelmann

    2017-06-01

    Full Text Available For a secure integration of weather dependent renewable energies in Germany's mixed power supply, precise forecasts of expected wind power are indispensable. These in turn are heavily dependent on numerical weather prediction (NWP. With this relevant area of application, NWP models need to be evaluated concerning new variables such as wind speed at hub heights of wind power plants. This article presents verification results of the deterministic NWP forecasts of the global ICON model, its ICON-EU nest, the COSMO-EU, and the COSMO-DE as well as of the ensemble prediction system COSMO-DE-EPS of the German National Weather Service (DWD, against wind mast observations. The focus is on the diurnal cycle in the Planetary Boundary Layer as wind power forecasts for Germany exhibit pronounced systematic amplitude and phase errors in the morning and evening hours. NWP forecasts with lead times up to 48 hours are examined. All considered NWP models reveal shortcomings concerning the representation of the diurnal cycle. Especially in summertime at onshore locations, when Low-Level Jets form, nocturnal wind speeds at hub height are underestimated. In the COSMO model, stable conditions are not sufficiently reflected in the first part of the night and the vertical mixing after sunrise establishes too late. The verification results of the COSMO-DE-EPS confirm the deficiencies of the deterministic forecasts. The deficiencies are present in all ensemble members and thus indicate potential for improvement not only in the model physics parameterization but also concerning the physical ensemble perturbations.

  16. Hydrogen Cycle in a Megacity: Diurnal Variation, Holiday Effect and Source Fingerprinting

    Science.gov (United States)

    Dubey, M. K.; Rahn, T. A.; Olsen, S.; Mazzoleni, C.; Zhang, Y.

    2007-05-01

    Mexico City with a population of 25 million, the largest mega-city in North America, provides a testing ground for regional and global impacts on air quality and climate of increasing urbanization. To help understand the biogeochemistry of Mexico City a comprehensive international multi-agency Megacity Initiative: Impact on Regional and Global Environment (MILAGRO) field campaign was conducted in March 2006. We report diurnal and weekly observations of molecular hydrogen, CO, and CO2 in Mexico City. A regular diurnal profile with peak concentrations of hydrogen in early morning caused by the high traffic and shallow boundary layer was revealed. A record level of hydrogen of 5 ppm, a factor of 10 above background levels, was measured. We hypothesize that most of the hydrogen is coming from automobiles. However, we did observe emissions from other industrial or power plant sources. Analysis of the H2/CO, CO/CO2, and H2/CO2 ratios are developed as a chemical fingerprinting method to delineate these sources and relate them to combustion efficiency. We utilize H2/CO ratios to diagnose traffic patterns, for example the early morning H2/CO peak is attributed to sluggish rush our traffic. We also observe significantly (25%) lower hydrogen during the weekend holidays than workdays. Finally, regional scale modeling of the Mexico City hydrogen cycle is performed using the Weather Research Forecast: Chemistry (WRF-CHM) model at 1 km resolution. The model results are compared to our measurements to gain a quantitative understanding of hydrogen sources and sinks in Mexico City. Our findings are significant to the understanding of the global hydrogen cycle and developing an urban baseline for hydrogen to assess potential perturbations to it from transitioning to a hydrogen economy.

  17. The Hydrogen Cycle in a Megacity: Diurnal Variation, Holiday Effect and Source Fingerprinting

    Science.gov (United States)

    Dubey, M. K.; Rahn, T. A.; Olsen, S.; Mazzoleni, C.; Zhang, Y.

    2006-12-01

    Mexico City with a population of 25 million, the largest mega-city in North America, provides a testing ground for regional and global impacts on air quality and climate of increasing urbanization. To help understand the biogeochemistry of Mexico City a comprehensive international multi-agency Megacity Initiative: Impact on Regional and Global Environment (MILAGRO) field campaign was conducted in March 2006. We report diurnal and weekly observations of molecular hydrogen, CO, and CO2 in Mexico City. A regular diurnal profile with peak concentrations of hydrogen in early morning caused by the high traffic and shallow boundary layer was revealed. A record level of hydrogen of 5 ppm, a factor of 10 above background, was measured. We hypothesize that most of the hydrogen is coming from automobiles; however, we did observe emissions from other industrial or power plant sources. Analysis of the H2/CO, CO/CO2, and H2/CO2 ratios are developed as a chemical fingerprinting method to delineate these sources and relate them to combustion efficiency. We also utilize H2/CO ratios to diagnose traffic patterns. For example, the early morning H2/CO peak is attributed to sluggish rush our traffic. Furthermore we observe significantly lower hydrogen during the weekend holidays than workdays. Finally, regional scale modeling of the Mexico City hydrogen cycle is performed using the Weather Research Forecast: Chemistry (WRF-CHM) model at 3 km resolution. The model results are compared to our measurements to gain a quantitative understanding of hydrogen sources and sinks in Mexico City. Our findings are significant to the understanding of the global hydrogen cycle and developing an urban baseline for hydrogen to assess potential perturbations to it from transitioning to a hydrogen economy.

  18. Contemporary model fidelity over the Maritime Continent: Examination of the diurnal cycle, synoptic, intraseasonal and seasonal variability

    Science.gov (United States)

    Baranowski, Dariusz

    2017-04-01

    One of the key challenges in subseasonal weather forecasting is the fidelity in representing the propagation of the Madden-Julian Oscillation (MJO) across the Maritime Continent (MC). In reality both propagating and non-propagating MJO events are observed, but in numerical forecast the latter group largely dominates. The fact that models still struggle to realistically represent the MJO over MC is generally attributed to its complex terrain and associated vigorous diurnal cycle of convection, multi-scale interactions between local and propagating modes of convection and regional air-sea interactions. In this study, multi-model simulations from the GEWEX Atmospheric System Study (GASS) / Year of Tropical Convection (YOTC) MJO Project are analyzed to quantify contemporary model performance in representing the MC mean climate and its variability, including the diurnal cycle, synoptic, intraseasonal, and seasonal variability. This dataset has been shown to be useful in such multi-model evaluation studies over different regions and/or focusing on different physical processes (e.g. Jiang et al., JGR, 2015; Mani et al., Clim. Dyn, 2016) For this study, comprehensive model performances are evaluated using metrics that utilize the mean precipitation pattern and the amplitude and phase of the diurnal cycle, with a particular focus on the linkage between a model's local MC variability and its fidelity in representing propagation of the MJO and equatorial Kelvin waves across the MC. Subseasonal to seasonal variability of mean precipitation and its diurnal cycle in 20 year long climate simulations from over 20 general circulation models (GCMs) is examined to benchmark model performance. Furthermore, we utilize cross model differences to gain insight into which processes are most critical to realistically represent multi-scale interactions over the MC region. This includes distinguishing the behavior between a number of land (Sumatra, Borneo, New Guinea and Southeast Asia) and

  19. Simulated precipitation diurnal cycles over East Asia using different CAPE-based convective closure schemes in WRF model

    Science.gov (United States)

    Yang, Ben; Zhou, Yang; Zhang, Yaocun; Huang, Anning; Qian, Yun; Zhang, Lujun

    2018-03-01

    Closure assumption in convection parameterization is critical for reasonably modeling the precipitation diurnal variation in climate models. This study evaluates the precipitation diurnal cycles over East Asia during the summer of 2008 simulated with three convective available potential energy (CAPE) based closure assumptions, i.e. CAPE-relaxing (CR), quasi-equilibrium (QE), and free-troposphere QE (FTQE) and investigates the impacts of planetary boundary layer (PBL) mixing, advection, and radiation on the simulation by using the weather research and forecasting model. The sensitivity of precipitation diurnal cycle to PBL vertical resolution is also examined. Results show that the precipitation diurnal cycles simulated with different closures all exhibit large biases over land and the simulation with FTQE closure agrees best with observation. In the simulation with QE closure, the intensified PBL mixing after sunrise is responsible for the late-morning peak of convective precipitation, while in the simulation with FTQE closure, convective precipitation is mainly controlled by advection cooling. The relative contributions of different processes to precipitation formation are functions of rainfall intensity. In the simulation with CR closure, the dynamical equilibrium in the free troposphere still can be reached, implying the complex cause-effect relationship between atmospheric motion and convection. For simulations in which total CAPE is consumed for the closures, daytime precipitation decreases with increased PBL resolution because thinner model layer produces lower convection starting layer, leading to stronger downdraft cooling and CAPE consumption. The sensitivity of the diurnal peak time of precipitation to closure assumption can also be modulated by changes in PBL vertical resolution. The results of this study help us better understand the impacts of various processes on the precipitation diurnal cycle simulation.

  20. Evaluating the impacts of climate change on diurnal wind power cycles using multiple regional climate models

    KAUST Repository

    Goddard, Scott D.

    2015-05-01

    Electrical utility system operators must plan resources so that electricity supply matches demand throughout the day. As the proportion of wind-generated electricity in the US grows, changes in daily wind patterns have the potential either to disrupt the utility or increase the value of wind to the system over time. Wind power projects are designed to last many years, so at this timescale, climate change may become an influential factor on wind patterns. We examine the potential effects of climate change on the average diurnal power production cycles at 12 locations in North America by analyzing averaged and individual output from nine high-resolution regional climate models comprising historical (1971–1999) and future (2041–2069) periods. A semi-parametric mixed model is fit using cubic B-splines, and model diagnostics are checked. Then, a likelihood ratio test is applied to test for differences between the time periods in the seasonal daily averaged cycles, and agreement among the individual regional climate models is assessed. We investigate the significant changes by combining boxplots with a differencing approach and identify broad categories of changes in the amplitude, shape, and position of the average daily cycles. We then discuss the potential impact of these changes on wind power production.

  1. Exploring diurnal and seasonal characteristics of global carbon cycle with GISS Model E2 GCM

    Science.gov (United States)

    Aleinov, I. D.; Kiang, N. Y.; Romanou, A.

    2017-12-01

    The ability to properly model surface carbon fluxes on the diurnal and seasonal time scale is a necessary requirement for understanding of the global carbon cycle. It is also one of the most challenging tasks faced by modern General Circulation Models (GCMs) due to complexity of the algorithms and variety of relevant spatial and temporal scales. The observational data, though abundant, is difficult to interpret at the global scale, because flux tower observations are very sparse for large impact areas (such as Amazon and African rainforest and most of Siberia) and satellite missions often struggle to produce sufficiently high confidence data over the land and may be missing CO2 amounts near the surface due to the nature of the method. In this work we use the GISS Model E2 GCM to perform a subset of experiments proposed by the Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP) and relate the results to available observations.The GISS Model E2 GCM is currently equipped with a complete global carbon cycle algorithm. Its surface carbon fluxes are computed by the Ent Terrestrial Biosphere Model (Ent TBM) over the land with observed leaf area index of the Moderate Resolution Imaging Spectrometer (MODIS) and by the NASA Ocean Biogeochemistry Model (NOBM) over the ocean. The propagation of atmospheric CO2 is performed by a generic Model E2 tracer algorithm, which is based on a quadratic upstream method (Prather 1986). We perform a series spin-up experiments for preindustrial climate conditions and fixed preindustrial atmospheric CO2 concentration. First, we perform separate spin-up simulations each for terrestrial and ocean carbon. We then combine the spun-up states and perform a coupled spin-up simulation until the model reaches a sufficient equilibrium. We then release restrictions on CO2 concentration and allow it evolve freely, driven only by simulated surface fluxes. We then study the results of the unforced run, comparing the amplitude and the phase

  2. Diurnal cycles control the fate of contaminants at an Andean river confluence impacted by legacy mining

    Science.gov (United States)

    Pasten, P.; Guerra, P. A.; Simonson, K.; Bonilla, C.; Pizarro, G. E.; Escauriaza, C. R.; González, C.

    2014-12-01

    The importance of hydrologic-geochemical interactions in arid environments is a controlling factor in quality and quantity of water available for human consumption and agriculture. When acid drainage affects these watersheds, water quality is gravely degraded. Despite its effect on watersheds, the relationship between time changes in hydrological variables and water quality in arid regions has not been studied thoroughly. Temporal variations in acid drainage can control when the transport of toxic elements is increased. We performed field work at the Azufre River (pH 2, E.C~10.9 mS/cm) and Caracarani River (pH 8.7, E.C~1.2 mS/cm) confluence, located in the Northern Chilean Altiplano (at 4000 m asl). We registered stream flowrates (total flowrate~430 L/s), temperature and electric conductivity (E.C) hourly using in-stream data loggers during one year. We also measured turbidity and pH during one field survey at different distances from the junction, as a proxy of the formation of iron-aluminum particles that cycle trace elements in these environments. We found turbidity-pH diurnal cycles were caused by upstream hourly changes in upstream flowrate: when the Caracarani River flowrate reached its daily peak, particle formation occurred, while the dissolution of particles occurred when the Azufre River reached its maximum value. This last process occurred due to upstream freeze-thaw cycles. This study shows how the dynamics of natural confluences determines chemical transport. The formation of particles enriched in toxic elements can promote settling as a natural attenuation process, while their dissolution will produce their release and transport long distances downstream. It is important to consider time as an important variable in water quality monitoring and in water management infrastructure where pulses of contamination can have potentially negative effects in its use. Acknowledgements: Funding was provided by "Proyecto Fondecyt 1130936" and "CONICYT

  3. Diurnal Freeze-Thaw Cycles Modify Winter Soil Respiration in a Desert Shrub-Land Ecosystem

    Directory of Open Access Journals (Sweden)

    Peng Liu

    2016-07-01

    Full Text Available Winter soil respiration (Rs is becoming a significant component of annual carbon budgets with more warming in winter than summer. However, little is known about the controlling mechanisms of winter Rs in dryland. We made continuous measurements of Rs in four microsites (non-crust (BS, lichen (LC, moss (MC, and a mixture of moss and lichen (ML in a desert shrub-land ecosystem northern China, to investigate the causes of Rs dynamics in winter. The mean winter Rs ranged from 0.10 to 0.17 µmol CO2 m−2·s−1 across microsites, with the highest value in BS. Winter Q10 (known as the increase in respiration rate per 10 °C increase in temperature values (2.8–19 were much higher than those from the growing season (1.5. Rs and Q10 were greatly enhanced in freeze-thaw cycles compared to frozen days. Diurnal patterns of Rs between freeze-thaw and frozen days differed. Although the freeze-thaw period was relatively short, its cumulative Rs contributed significantly to winter Rs. The presence of biocrust might induce lower temperature, thus having fewer freeze-thaw cycles relative to bare soil, leading to the lower Rs for microsites with biocrusts. In conclusion, winter Rs in drylands was sensitive to soil temperature (Ts and Ts-induced freeze-thaw cycles. The temperature impact on Rs varied among soil cover types. Winter Rs in drylands may become more important as the climate is continuously getting warmer.

  4. Effects of Tropical Islands on the Diurnal Cycle of Convection and its Influence on the MJO Propagation over the Maritime Continent

    Science.gov (United States)

    Savarin, A.; Chen, S. S.

    2017-12-01

    The Madden-Julian Oscillation (MJO) is a dominant mode of intraseasonal variability in the tropics. Large-scale convection fueling the MJO is initiated over the tropical Indian Ocean and propagates eastward across the Maritime Continent (MC) and into the western Pacific. Observational studies have shown that near 40-50% of the MJO events cannot pass through the MC, which is known as the MC barrier effect. Previous studies have also shown a strong diurnal cycle of convection over the islands and coastal seas, with an afternoon precipitation maximum over land and high terrain, and an early morning maximum over water and mountain valley areas. As an eastward-propagating MJO convective event passes over the MC, its nature may be altered due to the complex interaction with the large Islands and topography. In turn, the passage of an MJO event modulates local conditions over the MC. The diurnal cycle of convection over the MC and its modulation by the MJO are not well understood and poorly represented in global numerical prediction models. This study aims to improve our understanding of how the diurnal cycle of convection and the presence of islands of the MC affect the eastward propagation of the MJO over the region. To this end, we use the Unified Wave Interface-Coupled Model (UWIN-CM) in its fully-coupled atmosphere-ocean configuration at a convection-permitting (4 km) resolution over the region. The control simulation is from the MJO event that occurred in November-December 2011, and has been verified against the Dynamics of the MJO (DYNAMO) field campaign observations, TRMM precipitation, and reanalysis products. To investigate the effects of the tropical islands on the MJO, we conduct two additional numerical experiments, one with preserved island shape but flattened topography, and one where islands are replaced by water. The difference in the diurnal cycle and convective organization among these experiments will provide some insights on the origin of the MC

  5. Impact of Biomass Burning Aerosols on the Diurnal Cycle of Convective Clouds and Precipitation Over a Tropical Island

    Science.gov (United States)

    Hodzic, Alma; Duvel, Jean Philippe

    2018-01-01

    A coupled weather-aerosol model is used to study the effect of biomass burning aerosols on deep convection over the Borneo Island and surrounding oceans. Simulations are performed at the convection-permitting scale (4 km) for 40 days during the boreal summer and include interactive fire emissions and the aerosol effect on radiative and microphysical processes. Intense burning occurs daily in the southern part of the island, and smoke propagates northward to regions of deep convection. The model captures well the observed diurnal cycle of precipitation and high cloud cover. Cloud microphysics and radiative aerosol impacts are considered separately. Modifications of the cloud microphysics by smoke aerosols reinforce deep convection near the central Borneo mountainous region. This reinforced convection is due to reduced shallow precipitation in the afternoon that leads to a warm planetary boundary layer anomaly at sunset enhancing deep convection at night. Aerosol absorptive properties strongly affect local and synoptic atmospheric responses. The radiative processes of moderately absorbing aerosols tend to reduce deep convection over most regions due to local surface cooling and atmosphere warming that increase the static stability. For more absorbing aerosols, however, the impact is reversed with increased nighttime convection over most regions. This is partly related to changes in the vertical water vapor divergence profiles that decrease the convergence toward Borneo for moderately absorbing aerosols and increase it for more absorbing ones. These changes in the synoptic circulation due to large-scale aerosol perturbations are as important as local processes to explain the observed rainfall perturbation patterns.

  6. Size-resolved measurement of the mixing state of soot in the megacity Beijing, China: diurnal cycle, aging and parameterization

    Directory of Open Access Journals (Sweden)

    Y. F. Cheng

    2012-05-01

    Full Text Available Soot particles are the most efficient light absorbing aerosol species in the atmosphere, playing an important role as a driver of global warming. Their climate effects strongly depend on their mixing state, which significantly changes their light absorbing capability and cloud condensation nuclei (CCN activity. Therefore, knowledge about the mixing state of soot and its aging mechanism becomes an important topic in the atmospheric sciences.

    The size-resolved (30–320 nm diameter mixing state of soot particles in polluted megacity air was measured at a suburban site (Yufa during the CAREBeijing 2006 campaign in Beijing, using a volatility tandem differential mobility analyzer (VTDMA. Particles in this size range with non-volatile residuals at 300 °C were considered to be soot particles. On average, the number fraction of internally mixed soot in total soot particles (Fin, decreased from 0.80 to 0.57 when initial Dp increased from 30 to 320 nm. Further analysis reveals that: (1 Fin was well correlated with the aerosol hygroscopic mixing state measured by a CCN counter. More externally mixed soot particles were observed when particles showed more heterogeneous features with regard to hygroscopicity. (2 Fin had pronounced diurnal cycles. For particles in the accumulation mode (Dp at 100–320 nm, largest Fin were observed at noon time, with "apparent" turnover rates (kex → in up to 7.8% h−1. (3 Fin was subject to competing effects of both aging and emissions. While aging increases Fin by converting externally mixed soot particles into internally mixed ones, emissions tend to reduce Fin by emitting more fresh and externally mixed soot particles. Similar competing effects were also found with air mass age indicators. (4 Under the estimated emission

  7. Clouds, radiation, and the diurnal cycle of sea surface temperature in the tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Webster, P.J.; Clayson, C.A.; Curry, J.A. [Univ. of Colorado, Boulder, CO (United States)

    1996-04-01

    In the tropical Western Pacific (TWP) Ocean, the clouds and the cloud-radiation feedback can only be understood in the context of air/sea interactions and the ocean mixed layer. Considerable interest has been shown in attempting to explain why sea surface temperature (SST) rarely rises above 30{degrees}C, and gradients of the SST. For the most part, observational studies that address this issue have been conducted using monthly cloud and SST data, and the focus has been on intraseasonal and interannual time scales. For the unstable tropical atmosphere, using monthly averaged data misses a key feedback between clouds and SST that occurs on the cloud-SST coupling time scale, which was estimated to be 3-6 days for the unstable tropical atmosphere. This time scale is the time needed for a change in cloud properties, due to the change of ocean surface evaporation caused by SST variation, to feed back to the SST variation, to feed back to the SST through its effect on the surface heat flux. This paper addresses the relationship between clouds, surface radiation flux and SST of the TWP ocean over the diurnal cycle.

  8. Parameterization of convective transport in the boundary layer and its impact on the representation of the diurnal cycle of wind and dust emissions

    Directory of Open Access Journals (Sweden)

    F. Hourdin

    2015-06-01

    boundary layer by a mass flux scheme leads to realistic representation of the diurnal cycle of wind in spring, with a maximum near-surface wind in the morning. This maximum occurs when the thermal plumes reach the low-level jet that forms during the night at a few hundred meters above surface. The horizontal momentum in the jet is transported downward to the surface by compensating subsidence around thermal plumes in typically less than 1 h. This leads to a rapid increase of wind speed at surface and therefore of dust emissions owing to the strong nonlinearity of emission laws. The numerical experiments are performed with a zoomed and nudged configuration of the LMDZ general circulation model coupled to the emission module of the CHIMERE chemistry transport model, in which winds are relaxed toward that of the ERA-Interim reanalyses. The new set of parameterizations leads to a strong improvement of the representation of the diurnal cycle of wind when compared to a previous version of LMDZ as well as to the reanalyses used for nudging themselves. It also generates dust emissions in better agreement with current estimates, but the aerosol optical thickness is still significantly underestimated.

  9. The Antarctic krill Euphausia superba shows diurnal cycles of transcription under natural conditions.

    Directory of Open Access Journals (Sweden)

    Cristiano De Pittà

    Full Text Available BACKGROUND: Polar environments are characterized by extreme seasonal changes in day length, light intensity and spectrum, the extent of sea ice during the winter, and food availability. A key species of the Southern Ocean ecosystem, the Antarctic krill (Euphausia superba has evolved rhythmic physiological and behavioral mechanisms to adapt to daily and seasonal changes. The molecular organization of the clockwork underlying these biological rhythms is, nevertheless, still only partially understood. METHODOLOGY/PRINCIPAL FINDINGS: The genome sequence of the Antarctic krill is not yet available. A normalized cDNA library was produced and pyrosequenced in the attempt to identify large numbers of transcripts. All available E. superba sequences were then assembled to create the most complete existing oligonucleotide microarray platform with a total of 32,217 probes. Gene expression signatures of specimens collected in the Ross Sea at five different time points over a 24-hour cycle were defined, and 1,308 genes differentially expressed were identified. Of the corresponding transcripts, 609 showed a significant sinusoidal expression pattern; about 40% of these exibithed a 24-hour periodicity while the other 60% was characterized by a shorter (about 12-hour rhythm. We assigned the differentially expressed genes to functional categories and noticed that those concerning translation, proteolysis, energy and metabolic process, redox regulation, visual transduction and stress response, which are most likely related to daily environmental changes, were significantly enriched. Two transcripts of peroxiredoxin, thought to represent the ancestral timekeeping system that evolved about 2.5 billion years ago, were also identified as were two isoforms of the EsRh1 opsin and two novel arrestin1 sequences involved in the visual transduction cascade. CONCLUSIONS: Our work represents the first characterization of the krill diurnal transcriptome under natural conditions

  10. Strong hydrological control on nutrient cycling of subtropical rainforests

    Science.gov (United States)

    Lin, T. C.; Chang, C. T.; Huang, J. C.; Wang, L.; Lin, N. H.

    2016-12-01

    Forest nutrient cycling is strongly controlled by both biological and hydrological factors. However, based on a close examination of earlier reports, we highlight the role of hydrological control on nutrient cycling at a global scale and is more important at humid tropical and subtropical forests. we analyzed the nutrient budget of precipitation input and stream water output from 1994 to 2013 in a subtropical forest in Taiwan and conducted a data synthesis using results from 32 forests across the globe. The results revealed that monthly input and output of ions were positively correlated with water quantity, indicating hydrological control on nutrient cycling. Hydrological control is also evident from the greater ions export via stream water during the warm and wet growing season. The synthesis also illustrates that strong hydrological control leads to lower nitrogen retention and greater net loss of base cations in humid regions, particularly in the humid tropical and subtropical forests. Our result is of great significance in an era of global climate change because climate change could directly affect ecosystem nutrient cycling particularly in the tropics through changes in patterns of precipitation regime.

  11. Evaluation of convection-resolving models using satellite data: The diurnal cycle of summer convection over the Alps

    Directory of Open Access Journals (Sweden)

    Michael Keller

    2016-05-01

    Full Text Available Diurnal moist convection is an important element of summer precipitation over Central Europe and the Alps. It is poorly represented in models using parameterized convection. In this study, we investigate the diurnal cycle of convection during 11 days in June 2007 using the COSMO model. The numerical simulations are compared with satellite measurements of GERB and SEVIRI, AVHRR satellite-based cloud properties and ground-based precipitation and temperature measurements. The simulations use horizontal resolutions of 12 km (convection-parameterizing model, CPM and 2 km (convection-resolving model, CRM and either a one-moment microphysics scheme (1M or a two-moment microphysics scheme (2M.They are conducted for a computational domain that covers an extended Alpine area from Northern Italy to Northern Germany. The CPM with 1M exhibits a significant overestimation of high cloud cover. This results in a compensation effect in the top of the atmosphere energy budget due to an underestimation of outgoing longwave radiation (OLR and an overestimation of reflected solar radiation (RSR. The CRM reduces high cloud cover and improves the OLR bias from a domain mean of −20.1 to −2.6 W/m2. When using 2M with ice sedimentation in the CRM, high cloud cover is further reduced. The stronger diurnal cycle of high cloud cover and associated convection over the Alps, compared to less mountainous regions, is well represented by the CRM but underestimated by the CPM. Despite substantial differences in high cloud cover, the use of a 2M has no significant impact on the diurnal cycle of precipitation. Furthermore, a negative mid-level cloud bias is found for all simulations.

  12. ANNUAL AND DIURNAL CYCLES OF THE INVERSE RELATION BETWEEN PLANT TRANSPIRATION AND CARBON SEQUESTRATION

    Directory of Open Access Journals (Sweden)

    Hernán Alonso Moreno

    2008-07-01

    Full Text Available Understanding biogeochemical cycles and especially carbon budgets is clue to validate global change models in the present and near future. As a consequence, sinks and sources of carbon in the world are being studied. One of those sinks is the non-well known behavior of the planet vegetation which involves the processes of photosynthesis and respiration. Carbon sequestration rates are highly related to the transpiration through a molecular diffusion process occurring at the stomatal level which can be recorded by an eddy covariance micrometeorological station. This paper explores annual and diurnal cycles of latent heat (LE and CO2 net (FC fluxes over 6 different ecosystems. Based on the physics of the transpiration process, different time-scale analysis are performed, finding a near-linear relation between LE and CO2 net fluxes, which is stronger at the more vegetated areas. The North American monsoon season increases carbon up taking and LE-CO2 flux relation preserves at different time scales analysis (hours to days to months.El conocimiento de los ciclos biogeoquímicos y, en especial, de los balances de carbono es clave para la validación de los modelos de cambio global para el presente y el futuro cercano. Como consecuencia, en el mundo se estudian las fuentes y los sumideros de carbono. Uno de esos sumideros es la vegetación del planeta, que involucra los procesos de respiración y fotosíntesis y cuyo comportamiento se empieza a estudiar. Las tasas de captura del carbono están muy ligadas a la transpiración mediante un proceso de difusión molecular en los estomas, que puede registrarse por un sistema micrometeorológico de eddy covarianza. Este artículo explora los ciclos anuales y diurnos de los flujos netos de CO2 y calor latente de seis ecosistemas diferentes. Se desarrollan diversos análisis de escala temporal, basados en la física de la transpiración, y se halla una relación cuasilineal entre los flujos netos de calor

  13. An explanation for the different climate sensitivities of land and ocean surfaces based on the diurnal cycle

    Science.gov (United States)

    Kleidon, Axel; Renner, Maik

    2017-09-01

    Observations and climate model simulations consistently show a higher climate sensitivity of land surfaces compared to ocean surfaces. Here we show that this difference in temperature sensitivity can be explained by the different means by which the diurnal variation in solar radiation is buffered. While ocean surfaces buffer the diurnal variations by heat storage changes below the surface, land surfaces buffer it mostly by heat storage changes above the surface in the lower atmosphere that are reflected in the diurnal growth of a convective boundary layer. Storage changes below the surface allow the ocean surface-atmosphere system to maintain turbulent fluxes over day and night, while the land surface-atmosphere system maintains turbulent fluxes only during the daytime hours, when the surface is heated by absorption of solar radiation. This shorter duration of turbulent fluxes on land results in a greater sensitivity of the land surface-atmosphere system to changes in the greenhouse forcing because nighttime temperatures are shaped by radiative exchange only, which are more sensitive to changes in greenhouse forcing. We use a simple, analytic energy balance model of the surface-atmosphere system in which turbulent fluxes are constrained by the maximum power limit to estimate the effects of these different means to buffer the diurnal cycle on the resulting temperature sensitivities. The model predicts that land surfaces have a 50 % greater climate sensitivity than ocean surfaces, and that the nighttime temperatures on land increase about twice as much as daytime temperatures because of the absence of turbulent fluxes at night. Both predictions compare very well with observations and CMIP5 climate model simulations. Hence, the greater climate sensitivity of land surfaces can be explained by its buffering of diurnal variations in solar radiation in the lower atmosphere.

  14. An explanation for the different climate sensitivities of land and ocean surfaces based on the diurnal cycle

    Directory of Open Access Journals (Sweden)

    A. Kleidon

    2017-09-01

    Full Text Available Observations and climate model simulations consistently show a higher climate sensitivity of land surfaces compared to ocean surfaces. Here we show that this difference in temperature sensitivity can be explained by the different means by which the diurnal variation in solar radiation is buffered. While ocean surfaces buffer the diurnal variations by heat storage changes below the surface, land surfaces buffer it mostly by heat storage changes above the surface in the lower atmosphere that are reflected in the diurnal growth of a convective boundary layer. Storage changes below the surface allow the ocean surface–atmosphere system to maintain turbulent fluxes over day and night, while the land surface–atmosphere system maintains turbulent fluxes only during the daytime hours, when the surface is heated by absorption of solar radiation. This shorter duration of turbulent fluxes on land results in a greater sensitivity of the land surface–atmosphere system to changes in the greenhouse forcing because nighttime temperatures are shaped by radiative exchange only, which are more sensitive to changes in greenhouse forcing. We use a simple, analytic energy balance model of the surface–atmosphere system in which turbulent fluxes are constrained by the maximum power limit to estimate the effects of these different means to buffer the diurnal cycle on the resulting temperature sensitivities. The model predicts that land surfaces have a 50 % greater climate sensitivity than ocean surfaces, and that the nighttime temperatures on land increase about twice as much as daytime temperatures because of the absence of turbulent fluxes at night. Both predictions compare very well with observations and CMIP5 climate model simulations. Hence, the greater climate sensitivity of land surfaces can be explained by its buffering of diurnal variations in solar radiation in the lower atmosphere.

  15. Characteristics and Diurnal Cycle of GPM Rainfall Estimates over the Central Amazon Region

    Directory of Open Access Journals (Sweden)

    Rômulo Oliveira

    2016-06-01

    Full Text Available Studies that investigate and evaluate the quality, limitations and uncertainties of satellite rainfall estimates are fundamental to assure the correct and successful use of these products in applications, such as climate studies, hydrological modeling and natural hazard monitoring. Over regions of the globe that lack in situ observations, such studies are only possible through intensive field measurement campaigns, which provide a range of high quality ground measurements, e.g., CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GlobAl Precipitation Measurement and GoAmazon (Observations and Modeling of the Green Ocean Amazon over the Brazilian Amazon during 2014/2015. This study aims to assess the characteristics of Global Precipitation Measurement (GPM satellite-based precipitation estimates in representing the diurnal cycle over the Brazilian Amazon. The Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG and the Goddard Profiling Algorithm—Version 2014 (GPROF2014 algorithms are evaluated against ground-based radar observations. Specifically, the S-band weather radar from the Amazon Protection National System (SIPAM, is first validated against the X-band CHUVA radar and then used as a reference to evaluate GPM precipitation. Results showed satisfactory agreement between S-band SIPAM radar and both IMERG and GPROF2014 algorithms. However, during the wet season, IMERG, which uses the GPROF2014 rainfall retrieval from the GPM Microwave Imager (GMI sensor, significantly overestimates the frequency of heavy rainfall volumes around 00:00–04:00 UTC and 15:00–18:00 UTC. This overestimation is particularly evident over the Negro, Solimões and Amazon rivers due to the poorly-calibrated algorithm over water surfaces. On the other hand, during the dry season, the IMERG product underestimates mean precipitation in comparison to the S-band SIPAM

  16. Diurnal ozone cycle in the tropical and subtropical marine boundary layer

    NARCIS (Netherlands)

    Laat, A.T.J. de; Lelieveld, J.

    2000-01-01

    A conceptual analysis of diurnal ozone (O3 ) changes in the marine boundary layer (MBL) is presented. Such changes are most pronounced downwind of O3 sources in tropical and subtropical latitudes, and during summer at higher latitudes. Previously, it has been assumed that daytime photochemical O3

  17. Radiation closure and diurnal cycle of the clear-sky dust instantaneous direct radiative forcing over Arabian Peninsula

    KAUST Repository

    Osipov, Sergey

    2015-04-01

    To better quantify radiative effects of dust over the Arabian Peninsula we have developed a standalone column radiation transport model coupled with the Mie calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments are carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18-20 March 2012. Comprehensive ground-based observations and satellite retrievals are used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing are estimated both from the model and from observations. Diurnal cycle of the the shortwave instantaneous dust direct radiative forcing is studied for a range of aerosol and surface characteristics representative for the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing are evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions along with anisotropic aerosol scattering are mostly responsible for diurnal effects. We also discuss estimates of the climatological dust instantaneous direct radiative forcing over land and the Red Sea using two approaches. The first approach is based on the probability density function of the aerosol optical depth, and the second is based on the climatologically average Spinning Enhanced Visible and Infrared Imager (SEVIRI) aerosol optical depth. Results are compared with Geostationary Earth Radiation Budget (GERB) derived top of the atmosphere climatological forcing over the Red Sea.

  18. Photosynthetic bacterial growth and productivity under continuous illumination or diurnal cycles with olive mill wastewater as feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Eroglu, Ela [Middle East Technical University, Dept. of Chemical Engineering, 06531, Ankara (Turkey); University of California, Dept. of Plant and Microbial Biology, Berkeley, CA 94720-3102 (United States); Gunduz, Ufuk; Yucel, Meral [Middle East Technical University, Dept. of Biology, 06531, Ankara (Turkey); Eroglu, Inci [Middle East Technical University, Dept. of Chemical Engineering, 06531, Ankara (Turkey)

    2010-06-15

    Photofermentative hydrogen production from olive mill wastewater by Rhodobacter sphaeroides O.U.001 was investigated under different regimes of illumination. The analysis included measurements of biomass accumulation, H{sub 2}-production, high-value bio-product accumulation (polyhydroxybutyrate and carotenoid) and measurements of the medium pH as a function of growth and productivity. Batch cultures were grown under continuous light (CL) or 12 h light/12 h dark (12L/12D) diurnal cycles. Growth under CL or 12L/12D cycles yielded about the same amount of biomass (0.5 g dry cell weight per L culture) and volume of H{sub 2} gas (50 ml H{sub 2} per L culture). On the other hand, 12L/12D cultures showed a pronounced lag in biomass and H{sub 2} accumulation. Advances described in the work would find application in lowering operational costs for hydrogen production by better management of the energy source and cheap feedstock utilization. Compare to CL, equivalent amount of hydrogen gas accumulation within shorter time interval denoted to have two times higher hydrogen production rate and light conversion efficiencies via diurnal cycles, which can yield 50% savings on consumed energy source. (author)

  19. Sleep-wake cycle and diurnal fluctuation of amyloid-β as biomarkers of brain amyloid pathology

    OpenAIRE

    Roh, Jee Hoon; Huang, Yafei; Bero, Adam W.; Kasten, Tom; Stewart, Floy R.; Bateman, Randall J.; Holtzman, David M.

    2012-01-01

    Aggregation of amyloid-β (Aβ) in the brain begins to occur years prior to the clinical onset of Alzheimer’s disease (AD). Prior to Aβ aggregation, levels of extracellular, soluble interstitial fluid (ISF) Aβ, which are regulated by neuronal activity and the sleep-wake cycle, correlate with the amount of Aβ deposition in the brain seen later. The amount and quality of sleep declines with aging and to a greater extent in AD. How sleep quality amount as well as the diurnal fluctuation in Aβ chan...

  20. The Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site: An Atmospheric State-Based Analysis and Error Decomposition of a Multiscale Modeling Framework Simulation

    Science.gov (United States)

    Zhao, Wei; Marchand, Roger; Fu, Qiang

    2017-12-01

    Long-term reflectivity data collected by a millimeter cloud radar at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site are used to examine the diurnal cycle of clouds and precipitation and are compared with the diurnal cycle simulated by a Multiscale Modeling Framework (MMF) climate model. The study uses a set of atmospheric states that were created specifically for the SGP and for the purpose of investigating under what synoptic conditions models compare well with observations on a statistical basis (rather than using case studies or seasonal or longer time scale averaging). Differences in the annual mean diurnal cycle between observations and the MMF are decomposed into differences due to the relative frequency of states, the daily mean vertical profile of hydrometeor occurrence, and the (normalized) diurnal variation of hydrometeors in each state. Here the hydrometeors are classified as cloud or precipitation based solely on the reflectivity observed by a millimeter radar or generated by a radar simulator. The results show that the MMF does not capture the diurnal variation of low clouds well in any of the states but does a reasonable job capturing the diurnal variations of high clouds and precipitation in some states. In particular, the diurnal variations in states that occur during summer are reasonably captured by the MMF, while the diurnal variations in states that occur during the transition seasons (spring and fall) are not well captured. Overall, the errors in the annual composite are due primarily to errors in the daily mean of hydrometeor occurrence (rather than diurnal variations), but errors in the state frequency (that is, the distribution of weather states in the model) also play a significant role.

  1. Influences of the ENSO, oscillation Madden-Julian, waves of the east, hurricanes and moon phases on the diurnal cycle of precipitation at the tropical Andes of Colombia

    International Nuclear Information System (INIS)

    Poveda, German; Mesa, Oscar; Agudelo, Paula; Alvarez, Juan; Arias, Paola; Moreno, Hernan; Salazar, Luis; Toro, Vladimir; Vieira, Sara

    2002-01-01

    We study the effects of large-scale ocean-atmospheric, astronomic phenomena on the diurnal cycle of precipitation at the tropical Andes of Colombia. Such phenomena include both phases of El Nino/Southern Oscillation (ENSO), namely El Nino and La Nina, the intra seasonal Madden-Julian oscillation, tropical easterly waves (4-8 days), moon phases and hurricanes over the Atlantic and eastern pacific oceans. We found a clear-cut effect of both ENSO phases: El Nino is associated with a diminished rainfall diurnal cycle, and La Nina intensifies it. Thus, ENSO modulates precipitation in Colombia at timescales ranging from hours to decades. We identified a close association with different phases of the Madden-Julian oscillation, as the diurnal cycle is intensified (larger amplitude) during its westerly phase, but it gets decreased during its easterly phase. For both ENSO and the Madden-Julian oscillation we identified a clear-cut influence on the amplitude of the diurnal cycle, yet the phase is conserved for the most part. Tropical easterly waves appear to affect the diurnal cycle, but no clear overall signal is pervasive throughout the region. We al so found a significant statistical association with hurricanes occurring over the northeastern pacific ocean with the diurnal cycle of precipitation at rain gages located over the eastern slope of the eastern range of the Colombian Andes. Rainfall at all the remaining slopes of the Andes is statistically associated with hurricanes occurring at the tropical north Atlantic and the Caribbean Sea. Moon phases are not statistically associated with the diurnal cycle and daily total rainfall

  2. Estimation of Diurnal Cycle of Land Surface Temperature at High Temporal and Spatial Resolution from Clear-Sky MODIS Data

    Directory of Open Access Journals (Sweden)

    Si-Bo Duan

    2014-04-01

    Full Text Available The diurnal cycle of land surface temperature (LST is an important element of the climate system. Geostationary satellites can provide the diurnal cycle of LST with low spatial resolution and incomplete global coverage, which limits its applications in some studies. In this study, we propose a method to estimate the diurnal cycle of LST at high temporal and spatial resolution from clear-sky MODIS data. This method was evaluated using the MSG-SEVIRI-derived LSTs. The results indicate that this method fits the diurnal cycle of LST well, with root mean square error (RMSE values less than 1 K for most pixels. Because MODIS provides at most four observations per day at a given location, this method was further evaluated using only four MSG-SEVIRI-derived LSTs corresponding to the MODIS overpass times (10:30, 13:30, 22:30, and 01:30 local solar time. The results show that the RMSE values using only four MSG-SEVIRI-derived LSTs are approximately two times larger than those using all LSTs. The spatial distribution of the modeled LSTs at the MODIS pixel scale is presented from 07:00 to 05:00 local solar time of the next day with an increment of 2 hours. The diurnal cycle of the modeled LSTs describes the temporal evolution of the LSTs at the MODIS pixel scale.

  3. Influence of aerosol-radiative forcings on the diurnal and seasonal cycles of rainfall over West Africa and Eastern Atlantic Ocean using GCM simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyu-Myong [University of Maryland Baltimore County, Baltimore, MD (United States); Lau, William K.M.; Sud, Yogesh C. [Laboratory for Atmospheres, NASA/GSFC, Greenbelt, MD (United States); Walker, Gregory K. [SAIC/General Sciences Operation, Beltsville, MD (United States)

    2010-07-15

    Effects of aerosol radiative forcing on the diurnal and seasonal cycles of precipitation over West Africa and eastern Atlantic Ocean are investigated for the boreal summer season: June-July-August. An eight year (2000-2007) average of GCM simulated rainfall data is compared with the corresponding TRMM rainfall data. The comparison shows that the amplitude of the diurnal cycles of rainfall over land and ocean are reasonably well simulated. Over land, the phase of the simulated diurnal cycle of precipitation peaks several hours earlier than that of the TRMM data. Corresponding differences over the ocean(s) are relatively smaller. Some of the key features of the aerosol induced model simulated field anomalies are: (a) aerosol direct radiative forcing which increases the atmospheric stability and reduces the daytime moist convection and convective precipitation; (b) the aerosol induced changes in the diurnal cycle of precipitation are out of phase with those of the TRMM data over land, but are in-phase over the ocean; (c) aerosols reduce the amplitude of the diurnal cycle of precipitation over land and enhance it over ocean. However, the phase of the diurnal cycle is not affected much by the aerosol radiative forcing both over land and ocean. During the boreal summer, aerosol radiative forcing and induced circulation and precipitation cool the Sahel and the southern part of Sahara desert more than the adjacent areas to the north and south, thereby shifting the peak meridional temperature gradient northward. Consequently, an anomalous easterly jet is found north of its climatological location. This anomalous jet is associated with increased cyclonic circulation to the south of its axis, resulting in an anomalous monsoon rain belt in the Sahel. (orig.)

  4. The role of mesoscale convective systems in the diurnal cycle of rainfall and its seasonality over sub-Saharan Northern Africa

    Science.gov (United States)

    Liu, Weiran; Cook, Kerry H.; Vizy, Edward K.

    2018-03-01

    This study evaluates the role of MCSs in the total rainfall distribution as a function of season from a climatological perspective (1998-2014) over sub-Saharan northern Africa and examines how the diurnal cycle of rainfall changes with season. Tropical Rainfall Measuring Mission (TRMM) 3B42V7 rainfall estimates and European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis are used to evaluate the climatology. The percentages of the full TRMM precipitation delivered by MCSs have meridional structures in spring, fall and winter, ranging from 0 to 80% across sub-Saharan northern Africa, while the percentages are homogenous in summer (> 80%). The diurnal cycles of MCS-associated precipitation coincide with the full TRMM rainfall. Attributes of MCSs, including size, count, and intensity, vary synchronously with the diurnal cycle of rainfall. The diurnal peaks are classified into three categories: single afternoon peak, continuous afternoon peak, and nocturnal peak. Single afternoon peaks dominate in spring and fall while continuous afternoon and nocturnal peaks are more common in summer, indicating the seasonality of the diurnal cycle. The continuous afternoon peak combines rainfall from two system types—one locally-generated and one propagating. The seasonality of the diurnal cycle is related to the seasonality of MCS lifetimes, and propagation speeds and directions. The moisture component of the MSE profile contributes to the instability most in summer when convection is more frequent. Low-level temperature, which is related to surface warming and sensible heat fluxes, influences the instability more during winter and spring.

  5. Posttranscriptional mechanisms controlling diurnal gene expression cycles by body temperature rhythms.

    Science.gov (United States)

    Gotic, Ivana; Schibler, Ueli

    2017-10-03

    In mammals, body temperature oscillates in a daily fashion around a set point of 36°C-37°C. These fluctuations are controlled by the circadian master clock residing in the brain's suprachiasmatic nucleus and, despite their small amplitudes, contribute to the diurnal expression of genes throughout the organism. By focusing on the mechanisms underlying the temperature-dependent accumulation of the cold-inducible RNA-binding protein CIRBP - a factor involved in the tuning of amplitude and phase in circadian clocks of peripheral tissues - we have recently identified a novel mechanism governing temperature-dependent gene expression. This mechanism involves the differential spicing efficiency of primary RNA transcripts under different temperature conditions and thereby determines the fraction of Cirbp pre-mRNA processed into mature mRNA. A genome-wide transcriptome analysis revealed that this mechanism affects the output of hundreds of genes. Here we discuss our findings and future directions toward the identification of specific factors and parameters governing temperature-sensitive splicing efficacy.

  6. Impacts of the land-lake breeze of the Volta reservoir on the diurnal cycle of cloudiness and precipitation

    Science.gov (United States)

    Buchholz, Marcel; Fink, Andreas H.; Knippertz, Peter; Yorke, Charles

    2017-04-01

    Lake Volta in Ghana is the artificial lake on Earth with the largest surface area (8502 km2). It has been constructed in the early 1960s, with the lake being filled around 1966. Land-lake breezes and their effects on the diurnal cycle of local wind systems, cloudiness, and precipitation have been studied for several tropical lakes, among which studies on the effects of Lake Victoria in East Africa are one of the most perceived ones. To date, no studies on the strengths and effects of the land-lake breeze of the Volta reservoir are known to the authors. Using surface station data, a variety of satellite data on clouds and precipitation, and a convection-resolving regional model, the land-lake breeze and its impacts were studied for Lake Volta between 1998 and 2015. The observational data sets confirm a significant land-lake circulation. The only manned weather station operated by the Ghana Meteorological Service that is situated at the lake is Kete Krachi. Hourly observations for 2006 and 2014 show on several days a clearing of skies in the afternoon associated with a shift in the surface winds from southwest to southeast, the latter potentially indicating a lake breeze effect. Cloud occurrence frequency derived from the CLARA-A2, MODIS, and CLAAS2 cloud masks and the cloud physical properties from CLAAS2 clearly show the development of clouds at the lake breeze front in the course of the morning and around mid-day. This effect is most pronounced in March when also the difference between the surface temperatures of the lake and the desiccated land surface is strongest. During the peak of the wet season in July, the lake breeze cloudiness is masked by a high background cloudiness and likely also weaker due to the strong southwesterly monsoon flow that tends to weaken the land-lake circulation. However, the precipitation signal was found to be strongest in July, most probably due to the fact that in boreal fall, winter and spring, the lake breeze cloudiness often

  7. Role of Cumulus Parameterization Scheme on the Diurnal Cycle of Precipitation over Southeast Asia in RegCM4

    Science.gov (United States)

    Lui, Yuk Sing; Tam, Chi Yung Francis; Au-Yeung, Yee Man

    2017-04-01

    This study examines the sensitivity of precipitation simulations over the CORDEX-Southeast Asia (SEA) domain to the cumulus convection scheme used in the Regional Climate Model version 4 (RegCM4). With the ERA-interim reanalysis as lateral boundary conditions, model integrations using the MIT-Emanuel cumulus parameterization scheme, and those using a "mixed convection scheme" (namely with the MIT-Emanuel scheme over ocean and the Grell scheme with Arakawa Schubert-type closure over land), have been carried out for the 2001-2010 period. On the seasonal average, the use of the mixed convection scheme, in comparison to MIT-Emanuel scheme everywhere, improves rainfall simulations over the South China Sea (SCS) by reducing the summer-time wet bias there. On the other hand, runs with the mixed convection scheme under(over)-estimate rainfall over land in Southeastern China (western coastlines of Indochina and the Philippines). For the diurnal variation of precipitation, it is found that the RegCM4 can reproduce well the characteristics of the diurnal cycle (DC) in SEA. Compared with the mixed convection scheme, the MIT-Emanual scheme performs better in reproducing the amplitude and phase of DC over the landside coastal area of Indochina during summer. Empirical Orthogonal Function (EOF) analysis indicates that switching from the MIT-Emanuel scheme to the mixed convection scheme leads to a reduction in importance of the second EOF mode, which corresponds to rainfall peaked in the afternoon (local time). Further analyses reveal that such underestimation is related to increased cloud cover in RegCM4 using the mixed convection scheme; enhanced cloudiness in turn leads to reduced surface air temperature over land and thus reduced convective instability at 1200 and 1500 local time in the model simulations.

  8. Diurnal and menstrual cycles in body temperature are regulated differently: a 28-day ambulatory study in healthy women with thermal discomfort of cold extremities and controls.

    Science.gov (United States)

    Kräuchi, Kurt; Konieczka, Katarzyna; Roescheisen-Weich, Corina; Gompper, Britta; Hauenstein, Daniela; Schoetzau, Andreas; Fraenkl, Stephan; Flammer, Josef

    2014-02-01

    Diurnal cycle variations in body-heat loss and heat production, and their resulting core body temperature (CBT), are relatively well investigated; however, little is known about their variations across the menstrual cycle under ambulatory conditions. The main purpose of this study was to determine whether menstrual cycle variations in distal and proximal skin temperatures exhibit similar patterns to those of diurnal variations, with lower internal heat conductance when CBT is high, i.e. during the luteal phase. Furthermore, we tested these relationships in two groups of women, with and without thermal discomfort of cold extremities (TDCE). In total, 19 healthy eumenorrheic women with regular menstrual cycles (28-32 days), 9 with habitual TDCE (ages 29 ± 1.5 year; BMI 20.1 ± 0.4) and 10 controls without these symptoms (CON: aged 27 ± 0.8 year; BMI 22.7 ± 0.6; p temperature measurements of distal (mean of hands and feet) and proximal (mean of sternum and infraclavicular regions) skin regions, thighs, and calves were carried out under real-life, ambulatory conditions (i-Buttons® skin probes, sampling rate: 2.5 min). The distal minus proximal skin temperature gradient (DPG) provided a valuable measure for heat redistribution from the core to the shell, and, hence, for internal heat conduction. Additionally, basal body temperature was measured sublingually directly after waking up in bed. Mean diurnal amplitudes in skin temperatures increased from proximal to distal skin regions and the 24-h mean values were inversely related. TDCE compared to CON showed significantly lower hand skin temperatures and DPG during daytime. However, menstrual cycle phase did not modify these diurnal patterns, indicating that menstrual and diurnal cycle variations in skin temperatures reveal additive effects. Most striking was the finding that all measured skin temperatures, together with basal body temperature, revealed a similar menstrual cycle variation

  9. Comparison of data-driven and model-driven approaches to brightness temperature diurnal cycle interpolation

    CSIR Research Space (South Africa)

    Van den Bergh, F

    2006-01-01

    Full Text Available of the sequence no clouds were present, i.e. the cycle was complete without missing data. For each subsequent cycle this reference RKHS model was kept fixed and then just scaled and translated vertically to obtain the best least squares overlay. The 380 390 400... interpola- tion problem is novel. Results obtained by means of computer experiments are presented. 1. Introduction Remote sensing data obtained from earth observing satellites is frequently affected by cloud contamination, with about 50% of the globe...

  10. Diurnal cycle of methane flux from a lake, with high emissions during nighttime caused by convection in the water

    Science.gov (United States)

    Podgrajsek, E.; Sahlee, E.; Rutgersson, A.

    2012-12-01

    Many studies have stressed the importance of lakes as major contributors of methane to the atmosphere (e.g. Bastviken et al 2011). However there is still a lack of continuous long time flux measurements over lakes as well as poor understanding of the magnitude of methane fluxes through ebullition and vegetation pathways. In this study the Eddy covariance method has been used for measuring methane fluxes from a lake in central Sweden. At several occasions during the long time measuring campaign (autumn 2010-autumn 2012), a diurnal cycle of methane, with high fluxes during night and low during day, has been captured. Some of the high flux events during nighttime were comparable in magnitude to what previously only been measured from vegetation regions in lakes at these latitudes (e.g. Kankaala et al 2004) and from tropical reservoirs (e.g. Bastviken 2009). During these occasions the difference between air and water temperature (ΔT=Ta-Tw) also displayed an diurnal cycle, with ΔT being positive during day and negative during night with the corresponding change in the sensible heat flux i.e. negative during daytime and positive during nighttime. The high nighttime methane fluxes could be explained with this difference in air and water temperature, which will cool the water surface during night, creating convective mixing in the lake, while during daytime the water will be stably stratified. Temperature measurements made at different vertical levels in the lake water confirm this water stratification. The nighttime convective mixing may act to disturb the bottom water, triggering methane ebullition events and bringing methane rich water up to the surface, which can be emitted to the atmosphere. With this study we want to emphasis the necessity of introducing also complex physical processes when estimating air-water exchange fluxes and also measure methane fluxes not only at few occasions during daytime but also during night and for longer measuring periods. References

  11. Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs

    Directory of Open Access Journals (Sweden)

    Giordano Urbini

    2013-08-01

    Full Text Available The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because of the strong variations in the BOD5/NO3-N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD5 load is low. These phenomena cause inhibitory effects and BOD5 deficiency in the denitrification process. The results demonstrate the need for a more complex approach to designing and managing small wastewater treatment plants (WWTPs provided with denitrification than those usually adopted for medium- and large-size plants.

  12. Diurnal Ekman layer cycles at White Sands, New Mexico observed with Doppler lidar

    Science.gov (United States)

    Gunn, Andrew; Jerolmack, Douglas

    2017-11-01

    Atmospheric boundary layer turbulence is produced by shear and buoyancy, which are forced by larger-scale geostrophic and solar controls. Their absolute and relative inputs result in a nonlinear response of boundary-normal flow deflection within the Ekman layer. Classical analytical solutions for the deflection were found by assuming extrema of the shear-buoyancy phase space. At the chosen field site, a low-roughness long-fetch salt flat upwind of White Sands dune field, we employ a ground-based upward-facing Doppler lidar to observe the layer's dynamics throughout a continuous 70-day time series of wind vector measurements between 10 and 300 metres aloft. Within this domain we identify transition path bifurcation in the shear-buoyancy phase space, where deflection transience and the associated transformation of the vertical extent of the Ekman layer, are dependent on the daily stability cycle. Our analysis probes the natural system that is often modelled with idealised theory, revealing non-equilibrium dynamics that have implications within atmospheric science and geomorphology.

  13. Solar cycle distribution of strong solar proton events and the related solar-terrestrial phenomena

    Science.gov (United States)

    Le, Guiming; Yang, Xingxing; Ding, Liuguang; Liu, Yonghua; Lu, Yangping; Chen, Minhao

    2014-08-01

    We investigated the solar cycle distribution of strong solar proton events (SPEs, peak flux ≥1000 pfu) and the solar-terrestrial phenomena associated with the strong SPEs during solar cycles 21-23. The results show that 37 strong SPEs were registered over this period of time, where 20 strong SPEs were originated from the super active regions (SARs) and 28 strong SPEs were accompanied by the X-class flares. Most strong SPEs were not associated with the ground level enhancement (GLE) event. Most strong SPEs occurred in the descending phases of the solar cycles. The weaker the solar cycle, the higher the proportion of strong SPES occurred in the descending phase of the cycle. The number of the strong SPEs that occurred within a solar cycle is poorly associated with the solar cycle size. The intensity of the SPEs is highly dependent of the location of their source regions, with the super SPEs (≥20000 pfu) distributed around solar disk center. A super SPE was always accompanied by a fast shock driven by the associated coronal mass ejection and a great geomagnetic storm. The source location of strongest GLE event is distributed in the well-connected region. The SPEs associated with super GLE events (peak increase rate ≥100%) which have their peak flux much lower than 10000 pfu were not accompanied by an intense geomagnetic storm.

  14. The diurnal cycle of clouds and precipitation at the ARM SGP site: Cloud radar observations and simulations from the multiscale modeling framework

    Science.gov (United States)

    Zhao, Wei; Marchand, Roger; Fu, Qiang

    2017-07-01

    Millimeter Wavelength Cloud Radar (MMCR) data from December 1996 to December 2010, collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) site, are used to examine the diurnal cycle of hydrometeor occurrence. These data are categorized into clouds (-40 dBZe ≤ reflectivity < -10 dBZe), drizzle and light precipitation (-10 dBZe ≤ reflectivity < 10 dBZe), and heavy precipitation (reflectivity ≥ 10 dBZe). The same criteria are implemented for the observation-equivalent reflectivity calculated by feeding outputs from a Multiscale Modeling Framework (MMF) climate model into a radar simulator. The MMF model consists of the National Center for Atmospheric Research Community Atmosphere Model with conventional cloud parameterizations replaced by a cloud-resolving model. We find that a radar simulator combined with the simple reflectivity categories can be an effective approach for evaluating diurnal variations in model hydrometeor occurrence. It is shown that the MMF only marginally captures observed increases in the occurrence of boundary layer clouds after sunrise in spring and autumn and does not capture diurnal changes in boundary layer clouds during the summer. Above the boundary layer, the MMF captures reasonably well diurnal variations in the vertical structure of clouds and light and heavy precipitation in the summer but not in the spring.

  15. Simulated Diurnal Cycles and Seasonal Variability of Low-Level Jets in the Boundary Layer over Complex Terrain on the Coast of Southeast China

    Science.gov (United States)

    Shao, Min; Wang, Qin Geng; Xu, Jianjun

    2017-10-01

    The thermal and dynamical causes of boundary layer low-level jets (LLJs) over the southeast coast of China (a very complex terrain) are explored using a very high resolution diagnostic model California Meteorological (CALMET) along with the Advanced Research Weather Research and Forecasting (WRF-ARW) model, combined with observations. Both diurnal and seasonal variations in LLJs are investigated using simulations during two observational periods and four months in 2011. Two configurations, with different vertical and horizontal resolutions, are compared. The results show that the use of higher vertical and horizontal resolutions (including land cover/use) in the diagnostic model CALMET leads to large improvements in simulating boundary layer LLJs over complex terrain as compared with using lower vertical and horizontal resolutions in both WRF-ARW and CALMET models. The simulations using the diagnostic model CALMET better reproduced the observations, in that both LLJ events occur in the night (nocturnal LLJs) and in the afternoon (afternoon LLJs) are noticed. Compared to the nocturnal LLJs, the afternoon LLJs have larger wind speeds and occur at lower heights. The afternoon LLJ characteristics are closely associated with local thermodynamic circulations including the mountain-valley breeze and land-ocean breeze, which are regulated by the thermal contrasts between the ocean and mountains, and diurnal cycle of boundary layer friction. A comprehensive analysis of an afternoon LLJ and nocturnal LLJ indicates that there are large differences in wind field, vertical motions, and water vapor distributions between them. The local thermodynamic circulations also strongly affect vertical motions; even under a relatively stable atmosphere, the vertical motions during LLJs are stronger than the monthly average. Afternoon LLJ events, associated with the southeasterly land-ocean breeze in summer, occur more frequently than in winter; in contrast, nocturnal LLJ events occur in

  16. Diurnal changes in the xanthophyll cycle pigments of freshwater algae correlate with the environmental hydrogen peroxide concentration rather than non-photochemical quenching

    Science.gov (United States)

    Roach, Thomas; Miller, Ramona; Aigner, Siegfried; Kranner, Ilse

    2015-01-01

    Background and Aims In photosynthetic organisms exposure to high light induces the production of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), which in part is prevented by non-photochemical quenching (NPQ). As one of the most stable and longest-lived ROS, H2O2 is involved in key signalling pathways in development and stress responses, although in excess it can induce damage. A ubiquitous response to high light is the induction of the xanthophyll cycle, but its role in algae is unclear as it is not always associated with NPQ induction. The aim of this study was to reveal how diurnal changes in the level of H2O2 are regulated in a freshwater algal community. Methods A natural freshwater community of algae in a temporary rainwater pool was studied, comprising photosynthetic Euglena species, benthic Navicula diatoms, Chlamydomonas and Chlorella species. Diurnal measurements were made of photosynthetic performance, concentrations of photosynthetic pigments and H2O2. The frequently studied model organisms Chlamydomonas and Chlorella species were isolated to study photosynthesis-related H2O2 responses to high light. Key Results NPQ was shown to prevent H2O2 release in Chlamydomonas and Chlorella species under high light; in addition, dissolved organic carbon excited by UV-B radiation was probably responsible for a part of the H2O2 produced in the water column. Concentrations of H2O2 peaked at 2 µm at midday and algae rapidly scavenged H2O2 rather than releasing it. A vertical H2O2 gradient was observed that was lowest next to diatom-rich benthic algal mats. The diurnal changes in photosynthetic pigments included the violaxanthin and diadinoxanthin cycles; the former was induced prior to the latter, but neither was strictly correlated with NPQ. Conclusions The diurnal cycling of H2O2 was apparently modulated by the organisms in this freshwater algal community. Although the community showed flexibility in its levels of NPQ, the diurnal changes in

  17. TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

    NARCIS (Netherlands)

    Law, R. M.; Peters, W.; Roedenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S. -J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

    2008-01-01

    [1] A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

  18. TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

    NARCIS (Netherlands)

    Law, R. M.; Peters, W.; RöDenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S.-J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

    2008-01-01

    A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

  19. The Impact of the Afternoon Planetary Boundary-Layer Height on the Diurnal Cycle of CO and CO2 Mixing Ratios at a Low-Altitude Mountaintop

    Science.gov (United States)

    Lee, Temple R.; De Wekker, Stephan F. J.; Pal, Sandip

    2018-02-01

    Mountaintop trace-gas mixing ratios are often assumed to represent free atmospheric values, but are affected by valley planetary boundary-layer (PBL) air at certain times. We hypothesize that the afternoon valley-PBL height relative to the ridgetop is important in the diurnal cycle of mountaintop trace-gas mixing ratios. To investigate this, we use, (1) 4-years (1 January 2009-31 December 2012) of CO and CO2 mixing-ratio measurements and supporting meteorological observations from Pinnacles (38.61°N , 78.35°W , 1017 m a.s.l.), which is a monitoring site in the Appalachian Mountains, (2) regional O3 mixing-ratio measurements, and (3) PBL heights determined from a nearby sounding station. Results reveal that the amplitudes of the diurnal cycles of CO and CO2 mixing ratios vary as a function of the daytime maximum valley-PBL height relative to the ridgetop. The mean diurnal cycle for the subset of days when the afternoon valley-PBL height is at least 400 m below the ridgetop shows a daytime CO mixing-ratio increase, implying the transport of PBL air from the valley to the mountaintop. During the daytime, on days when the PBL heights exceed the mountaintop, PBL dilution and entrainment cause CO mixing ratios to decrease. This decrease in CO mixing ratio, especially on days when PBL heights are at least 400 m above the ridgetop, suggests that measurements from these days can be used as with afternoon measurements from flat terrain in applications requiring regionally-representative measurements.

  20. Heterogeneous Boundary Layers through the Diurnal Cycle: Evaluation of the WRF Wind Farm Parameterization using Scanning Lidar Observations and Wind Turbine Power Measurements during a Range of Stability Conditions

    Science.gov (United States)

    Lundquist, J. K.

    2015-12-01

    As wind energy deployment increases, questions arise regarding impacts on local climates and how these impacts evolve with the diurnal cycle of the boundary layer. Satellite observations suggest nocturnal increases of surface temperatures, and measurements of turbine wakes document stronger and more persistent reductions of wind speed and increases in turbulence downwind of turbines during stable conditions. Validations of mesoscale parameterizations of these effects have been constrained to idealized conditions defined by neutrally-stratified conditions and/or limited wind directions and wind speeds, or by comparison to idealized large-eddy simulations. Synthesis of conventional meteorological measurements and unconventional measurements can offer unique insights for validating models over a large heterogeneous domain. The CWEX-13 field experiment provides an extensive dataset for such validation at spatial scales on the order of 10 km in a range of atmospheric stability and wind conditions. CWEX-13 took place within a 300 MW wind farm in central Iowa during summer 2013 and featured strong diurnal cycles. The wind turbines are sited irregularly, creating a heterogenous "canopy". Three profiling lidars, numerous surface flux stations, and a scanning lidar sampled wakes from multiple turbines. Further, the wind farm owner/operator has provided access to turbine power production and wind speed measurement data for model validation, providing ~ 200 measurements of proxies that integrate the wind profile over the rotor disk, from 40 m to 120 m above the surface. Building on previous work that identified optimal physics options, grid configurations, and boundary condition data sets by comparison to lidar wind profile measurements, we execute simulations with the WRF Wind Farm Parameterization for a ten-day period featuring moderate winds and strong diurnal cycles. We evaluate simulations with different modeling choices (e.g., vertical resolution, approaches to

  1. The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin Australia)

    Energy Technology Data Exchange (ETDEWEB)

    May, Peter T.; Long, Charles N.; Protat, Alain

    2012-08-01

    The diurnal variation of convection and associated cloud and radiative properties remains a significant issue in global NWP and climate models. This study analyzes observed diurnal variability of convection in a coastal monsoonal environment examining the interaction of convective rain clouds, their associated cloud properties, and the impact on the surface radiation and corresponding boundary layer structure during periods where convection is suppressed or active on the large scale. The analysis uses data from the Tropical Warm Pool International Cloud Experiment (TWP-ICE) as well as routine measurements from the Australian Bureau of Meteorology and the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. Both active monsoonal and large-scale suppressed (buildup and break) conditions are examined and demonstrate that the diurnal variation of rainfall is much larger during the break periods and the spatial distribution of rainfall is very different between the monsoon and break regimes. During the active monsoon the total net radiative input to the surface is decreased by more than 3 times the amount than during the break regime - this total radiative cloud forcing is found to be dominated by the shortwave (SW) cloud effects because of the much larger optical thicknesses and persistence of long-lasting anvils and cirrus cloud decks associated with the monsoon regime. These differences in monsoon versus break surface radiative energy contribute to low-level air temperature differences in the boundary layer over the land surfaces.

  2. Spatial Variability of the Background Diurnal Cycle of Deep Convection around the GoAmazon2014/5 Field Campaign Sites

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Feng, Zhe; Hagos, Samson M.; Fast, Jerome; Machado, Luiz A. T.; Martin, Scot T.

    2016-07-01

    The Amazon rainforest is one of a few regions of the world where continental tropical deep convection occurs. The Amazon’s isolation makes it challenging to observe, but also creates a unique natural laboratory to study anthropogenic impacts on clouds and precipitation in an otherwise pristine environment. Extensive measurements were made upwind and downwind of the large city of Manaus, Brazil during the Observations and Modeling of the Green Ocean Amazon 2014-2015 (GoAmazon2014/5) field campaign. In this study, 15 years of high-resolution satellite data are analyzed to examine the spatial and diurnal variability of convection occurring around the GoAmazon2014/5 sites. Interpretation of anthropogenic differences between the upwind (T0) and downwind (T1-T3) sites is complicated by naturally-occurring spatial variability between the sites. During the rainy season, the inland propagation of the previous day’s sea-breeze front happens to be in phase with the background diurnal cycle near Manaus, but is out of phase elsewhere. Enhanced convergence between the river-breezes and the easterly trade winds generates up to 10% more frequent deep convection at the GoAmazon2014/5 sites east of the river (T0a, T0t/k, and T1) compared to the T3 site which was located near the western bank. In general, the annual and diurnal cycles during 2014 were representative of the 2000-2013 distributions. The only exceptions were in March when the monthly mean rainrate was above the 95th percentile and September when both rain frequency and intensity were suppressed. The natural spatial variability must be accounted for before interpreting anthropogenically-induced differences among the GoAmazon2014/5 sites.

  3. Size-resolved measurement of the mixing state of soot in the megacity Beijing, China: Diurnal cycle, aging and parameterization

    Science.gov (United States)

    Cheng, Y. F.; Su, H.; Rose, D.; Gunthe, S. S.; Berghof, M.; Wehner, B.; Achtert, P.; Nowak, A.; Takegawa, N.; Kondo, Y.; Shiraiwa, M.; Gong, Y. G.; Shao, M.; Hu, M.; Zhu, T.; Zhang, Y. H.; Wiedensohler, A.; Andreae, M. O.; Pöschl, U.

    2013-05-01

    In the summer of 2006, measurements of the mixing state of non-volatile particles were carried out at a suburban site of Beijing in the North China Plain by using a VTDMA. In this study, we perform an in-depth analysis of VTDMA results, focusing on the following topics: (1) comparison of the mixing state of soot measured by a VTDMA and the aerosol hygroscopicity mixing state determined by a CCN (cloud condensation nuclei) counter; (2) diurnal variation and evolution of soot mixing state at different size ranges; (3) calculation of kex→in and the influence of emissions on it; and (4) potential parameterization methods.

  4. Diurnal cycle and seasonal variation of cloud cover over the Tibetan Plateau as determined from Himawari-8 new-generation geostationary satellite data.

    Science.gov (United States)

    Shang, Huazhe; Letu, Husi; Nakajima, Takashi Y; Wang, Ziming; Ma, Run; Wang, Tianxing; Lei, Yonghui; Ji, Dabin; Li, Shenshen; Shi, Jiancheng

    2018-01-18

    Analysis of cloud cover and its diurnal variation over the Tibetan Plateau (TP) is highly reliant on satellite data; however, the accuracy of cloud detection from both polar-orbiting and geostationary satellites over this area remains unclear. The new-generation geostationary Himawari-8 satellites provide high-resolution spatial and temporal information about clouds over the Tibetan Plateau. In this study, the cloud detection of MODIS and AHI is investigated and validated against CALIPSO measurements. For AHI and MODIS, the false alarm rate of AHI and MODIS in cloud identification over the TP was 7.51% and 1.94%, respectively, and the cloud hit rate was 73.55% and 80.15%, respectively. Using hourly cloud-cover data from the Himawari-8 satellites, we found that at the monthly scale, the diurnal cycle in cloud cover over the TP tends to increase throughout the day, with the minimum and maximum cloud fractions occurring at 10:00 a.m. and 18:00 p.m. local time. Due to the limited time resolution of polar-orbiting satellites, the underestimation of MODIS daytime average cloud cover is approximately 4.00% at the annual scale, with larger biases during the spring (5.40%) and winter (5.90%).

  5. Observations of NOx, ΣPNs, ΣANs, and HNO3 at a Rural Site in the California Sierra Nevada Mountains: summertime diurnal cycles

    Directory of Open Access Journals (Sweden)

    P. J. Wooldridge

    2009-07-01

    Full Text Available Observations of NO, NO2, total peroxy nitrates (ΣPNs, total alkyl nitrates (ΣANs, HNO3, CO, O3, and meteorological parameters were obtained from October 2000 through February 2002 at 1315 m a.s.l., 38.9° N, 120.6° W on Sierra Pacific Industries land, adjacent to the University of California Blodgett Forest Research Station (UC-BFRS. We describe the data set with emphasis on the diurnal cycles during summertime 2001. We show that transport of the Sacramento urban plume is a primary factor responsible for diurnal variation in total reactive nitrogen mixing ratios as well as in NOx, ΣPNs and ΣANs, all of which exhibit a late afternoon/early evening peak. In contrast, HNO3 has a peak just after local noon indicating that HNO3 is in near steady state during the day with production due to photochemistry and removal by deposition and mixing with the background free troposphere. Boundary layer dynamics influence mixing ratios of all species in the early morning. Analysis of the morning feature suggests that higher mixing ratios of NOx and HNO3 persist in the residual layer than in the nocturnal boundary layer indicating the presence of nocturnal sinks of both species. Nighttime observations also indicate large HNO3 and ΣANs production through oxidation of alkenes by NO3.

  6. Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

    OpenAIRE

    Massimo Raboni; Vincenzo Torretta; Giordano Urbini

    2013-01-01

    The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because ...

  7. Carrier envelope phase effects in molecular dissociation by few-cycle strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, K I [Hellenic Army Academy, Department of Natural Science and Applications, Vari (Greece); Constantoudis, V [Institute of Microelectronics, NCSR ' Demokritos' , Athens (Greece); Mercouris, Th [Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens (Greece); Nicolaides, C A, E-mail: dimi@eie.g [Physics Department, National Technical University, Athens (Greece)

    2009-11-01

    Multiphoton molecular dissociation produced by few-cycle strong laser fields of mid-infrared wave lengths is studied theoretically. The dependence of the carrier envelope phase (CEP) on the photodissociation dynamics is investigated using both quantum and classical nonperturbative approaches. Our results show that dissociation is affected by the changes of the CEP. A detailed analysis shows that this dependence is sensitive to the duration and to the shape of the pulse.

  8. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  9. On the diurnal cycle of urban aerosols, black carbon and the occurrence of new particle formation events in springtime São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    J. Backman

    2012-12-01

    Full Text Available Large conurbations are a significant source of the anthropogenic pollution and demographic differences between cities that result in a different pollution burden. The metropolitan area of São Paulo (MASP, population 20 million accounts for one fifth of the Brazilian vehicular fleet. A feature of MASP is the amount of ethanol used by the vehicular fleet, known to exacerbate air quality. The study describes the diurnal behaviour of the submicron aerosol and relies on total particle number concentration, particle number size distribution, light scattering and light absorption measurements. Modelled planetary boundary layer (PBL depth and air mass movement data were used to aid the interpretation. During morning rush-hour, stagnant air and a shallow PBL height favour the accumulation of aerosol pollution. During clear-sky conditions, there was a wind shift towards the edge of the city indicating a heat island effect with implications on particulate pollution levels at the site. The median total particle number concentration for the submicron aerosol typically varied in the range 1.6 × 104–3.2 × 104 cm−3 frequently exceeding 4 × 104 cm−3 during the day. During weekdays, nucleation-mode particles are responsible for most of the particles by numbers. The highest concentrations of total particle number concentrations and black carbon (BC were observed on Fridays. Median diurnal values for light absorption and light scattering (at 637 nm wavelength varied in the range 12–33 Mm−1 and 21–64 Mm−1, respectively. The former one is equal to 1.8–5.0 μg m−3 of BC. The growth of the PBL, from the morning rush-hour until noon, is consistent with the diurnal cycle of BC mass concentrations. Weekday hourly median single-scattering albedo (ω0 varied in the range 0.59–0.76. Overall, this suggests a top of atmosphere (TOA warming effect. However

  10. Formation of a strong southward IMF near the solar maximum of cycle 23

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    S. Watari

    2004-01-01

    Full Text Available We analyzed observations of the solar activities and the solar wind parameters associated with large geomagnetic storms near the maximum of solar cycle 23. This analysis showed that strong southward interplanetary magnetic fields (IMFs, formed through interaction between an interplanetary disturbance, and background solar wind or between interplanetary disturbances are an important factor in the occurrence of intense geomagnetic storms. Based on our analysis, we seek to improve our understanding of the physical processes in which large negative Bz's are created which will lead to improving predictions of space weather.

    Key words. Interplanetary physics (Flare and stream dynamics; Interplanetary magnetic fields; Interplanetary shocks

  11. STATISTICAL STUDY OF STRONG AND EXTREME GEOMAGNETIC DISTURBANCES AND SOLAR CYCLE CHARACTERISTICS

    International Nuclear Information System (INIS)

    Kilpua, E. K. J.; Olspert, N.; Grigorievskiy, A.; Käpylä, M. J.; Tanskanen, E. I.; Pelt, J.; Miyahara, H.; Kataoka, R.; Liu, Y. D.

    2015-01-01

    We study the relation between strong and extreme geomagnetic storms and solar cycle characteristics. The analysis uses an extensive geomagnetic index AA data set spanning over 150 yr complemented by the Kakioka magnetometer recordings. We apply Pearson correlation statistics and estimate the significance of the correlation with a bootstrapping technique. We show that the correlation between the storm occurrence and the strength of the solar cycle decreases from a clear positive correlation with increasing storm magnitude toward a negligible relationship. Hence, the quieter Sun can also launch superstorms that may lead to significant societal and economic impact. Our results show that while weaker storms occur most frequently in the declining phase, the stronger storms have the tendency to occur near solar maximum. Our analysis suggests that the most extreme solar eruptions do not have a direct connection between the solar large-scale dynamo-generated magnetic field, but are rather associated with smaller-scale dynamo and resulting turbulent magnetic fields. The phase distributions of sunspots and storms becoming increasingly in phase with increasing storm strength, on the other hand, may indicate that the extreme storms are related to the toroidal component of the solar large-scale field

  12. Streptomyces clavuligerus shows a strong association between TCA cycle intermediate accumulation and clavulanic acid biosynthesis.

    Science.gov (United States)

    Ramirez-Malule, Howard; Junne, Stefan; Nicolás Cruz-Bournazou, Mariano; Neubauer, Peter; Ríos-Estepa, Rigoberto

    2018-05-01

    Clavulanic acid (CA) is produced by Streptomyces clavuligerus (S. clavuligerus) as a secondary metabolite. Knowledge about the carbon flux distribution along the various routes that supply CA precursors would certainly provide insights about metabolic performance. In order to evaluate metabolic patterns and the possible accumulation of tricarboxylic acid (TCA) cycle intermediates during CA biosynthesis, batch and subsequent continuous cultures with steadily declining feed rates were performed with glycerol as the main substrate. The data were used to in silico explore the metabolic capabilities and the accumulation of metabolic intermediates in S. clavuligerus. While clavulanic acid accumulated at glycerol excess, it steadily decreased at declining dilution rates; CA synthesis stopped when glycerol became the limiting substrate. A strong association of succinate, oxaloacetate, malate, and acetate accumulation with CA production in S. clavuligerus was observed, and flux balance analysis (FBA) was used to describe the carbon flux distribution in the network. This combined experimental and numerical approach also identified bottlenecks during the synthesis of CA in a batch and subsequent continuous cultivation and demonstrated the importance of this type of methodologies for a more advanced understanding of metabolism; this potentially derives valuable insights for future successful metabolic engineering studies in S. clavuligerus.

  13. The Impact of the Diurnal Cycle of Clouds and Precipitation over the Maritime Continent on the Propagation of the MJO into the Western Pacific

    Science.gov (United States)

    Burleyson, C. D.; Hagos, S. M.; Feng, Z.

    2016-12-01

    The processes that determine the interaction between the islands of the maritime continent (MC) and the eastward propagation of the Madden-Julian Oscillation (MJO) are poorly understood. We are undertaking a series of observational and modeling analyses aimed at understanding how clouds and precipitation over the islands of the MC lead to changes in the intensity of the MJO (inferred by the amplitude of the Real-time Multivariate MJO index [RMM] and other metrics) as it crosses the MC. One component of our analysis uses the long-term measurements from the DOE Atmospheric Radiation Measurement (ARM) sites in the Tropical Western Pacific (TWP) to examine cloud radiative effects as the MJO crosses the MC. Using the multi-year ARM dataset and a cloud resolving model (CRM), we show that the MJO interacts with the diurnal cycle of surface heating, clouds, and precipitation over the islands of the MC in a way that weakens it. Additionally, using a satellite climatology based on the TRMM 3B42 dataset we found that MJO episodes that weaken as they cross the MC are characterized by more frequent precipitation and warmer sea surface temperatures (SSTs) south of the equator and less frequent precipitation north of the equator compared to cases where the MJO intensifies. The north-south polarity in SSTs suggests a seasonal dependence in the ability of the MJO to cross the MC. This seasonality was confirmed by looking the seasonal distribution of changes in MJO amplitude as it crosses the MC. Consistent with the SST result, we found that MJO episodes that intensify as they cross the MC are more likely to occur during the northern hemisphere summer and less likely to occur during the northern hemisphere winter (Fig. 1). A regional CRM and satellite observations are used jointly to explore the processes responsible for this seasonality and to examine the impact of interannual oscillations such as ENSO and monsoons on the ability of the MJO to cross the MC. Fig. 1. The annual

  14. An overview of the diurnal cycle of the atmospheric boundary layer during the West African monsoon season: results from the 2016 observational campaign

    Science.gov (United States)

    Kalthoff, Norbert; Lohou, Fabienne; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Babić, Karmen; Dione, Cheikh; Ajao, Adewale; Amekudzi, Leonard K.; Aryee, Jeffrey N. A.; Ayoola, Muritala; Bessardon, Geoffrey; Danuor, Sylvester K.; Handwerker, Jan; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas; Fink, Andreas H.; Knippertz, Peter

    2018-03-01

    A ground-based field campaign was conducted in southern West Africa from mid-June to the end of July 2016 within the framework of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project. It aimed to provide a high-quality comprehensive data set for process studies, in particular of interactions between low-level clouds (LLCs) and boundary-layer conditions. In this region missing observations are still a major issue. During the campaign, extensive remote sensing and in situ measurements were conducted at three supersites: Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). Daily radiosoundings were performed at 06:00 UTC, and 15 intensive observation periods (IOPs) were performed during which additional radiosondes were launched, and remotely piloted aerial systems were operated. Extended stratiform LLCs form frequently in southern West Africa during the nighttime and persist long into the following day. They affect the radiation budget and hence the evolution of the atmospheric boundary layer and regional climate. The relevant parameters and processes governing the formation and dissolution of the LLCs are still not fully understood. This paper gives an overview of the diurnal cycles of the energy-balance components, near-surface temperature, humidity, wind speed and direction as well as of the conditions (LLCs, low-level jet) in the boundary layer at the supersites and relates them to synoptic-scale conditions (monsoon layer, harmattan layer, African easterly jet, tropospheric stratification) in the DACCIWA operational area. The characteristics of LLCs vary considerably from day to day, including a few almost cloud-free nights. During cloudy nights we found large differences in the LLCs' formation and dissolution times as well as in the cloud-base height. The differences exist at individual sites and also between the sites. The synoptic conditions are characterized by a monsoon layer with south-westerly winds, on average about 1.9 km

  15. Four years of CO2 and meteorological measurements in Mataró (Catalonia, Spain). An example of the CO2 diurnal cycles in a Mediterranean coastal city.

    Science.gov (United States)

    Curcoll Masanes, Roger; Font, Anna; Comerma, Marta; Morguí, Josep-Anton; Àgueda, Alba; Batet, Oscar; Cañas, Lidia; Grossi, Claudia; Nofuentes, Manel; Occhipinti, Paola; Rodó, Xavier

    2014-05-01

    Since November 2009, in collaboration with the science section of the Mataró Museum, IC3 is measuring CO2 concentration in the roof of this museum using a calibrated infrared (IR) analyzer (GMP343 Vaisala Carbocap®). The measurements began within the frame of the CarboSchools project (EU Science in Society programme). Meteorological variables (ambient temperature, relative humidity, precipitation, barometric pressure, wind direction and wind speed) are also measured with a Davis Vantage Pro2 Station. The Mataró Museum is located in the Mediterranean coastal city of Mataró (41.540174° N, 2.445486° E), 25 Km north-east of Barcelona. The in-situ meteorological data (pressure, temperature and humidity) is used to adjust the settings of the GMP343 every minute to calculate CO2 concentration. From late 2009 to 2012 CO2 data was calibrated using integrated discrete flask samples that were collected fortnightly and then measured using an optical analyzer (Licor-7000). From 2013 onwards CO2 GMP343 data has been calibrated by data inter-comparison with a Picarro G2301. Both the Picarro G2301 and the Licor-7000 analyzers were calibrated and referred to the International Scale using a scale strategy with seven NOAA reference cylinders. The dataset shows that CO2 signal in the coastal city of Mataró is regulated by the periodic land-sea breezes and the local emissions. The CO2 variability along the year (diurnal and seasonal CO2 signal) responds to the variability of the influence of the sea-land breezes, the contribution of the land and the sea ecosystems in the CO2 cycle and the variability of anthropogenic emissions Finally the CO2 data from Mataró is compared with the CO2 time series from other stations which have the same equipment but are located in different ecosystems. The other stations presented here are (1) DEC3: Located at the Ebre River Delta in a coastal and agricultural area. This station is also provided with GC and Picarro instrumentation and is part of

  16. The effect of sulfate concentration on (sub)millimeter-scale sulfide δ 34S in hypersaline cyanobacterial mats over the diurnal cycle

    Science.gov (United States)

    Fike, David A.; Finke, Niko; Zha, Jessica; Blake, Garrett; Hoehler, Tori M.; Orphan, Victoria J.

    2009-10-01

    Substantial isotopic fractionations are associated with many microbial sulfur metabolisms and measurements of the bulk δ 34S isotopic composition of sulfur species (predominantly sulfates and/or sulfides) have been a key component in developing our understanding of both modern and ancient biogeochemical cycling. However, the interpretations of bulk δ 34S measurements are often non-unique, making reconstructions of paleoenvironmental conditions or microbial ecology challenging. In particular, the link between the μm-scale microbial activity that generates isotopic signatures and their eventual preservation as a bulk rock value in the geologic record has remained elusive, in large part because of the difficulty of extracting sufficient material at small scales. Here we investigate the potential for small-scale (˜100 μm-1 cm) δ 34S variability to provide additional constraints for environmental and/or ecological reconstructions. We have investigated the impact of sulfate concentrations (0.2, 1, and 80 mM SO 4) on the δ 34S composition of hydrogen sulfide produced over the diurnal (day/night) cycle in cyanobacterial mats from Guerrero Negro, Baja California Sur, Mexico. Sulfide was captured as silver sulfide on the surface of a 2.5 cm metallic silver disk partially submerged beneath the mat surface. Subsequent analyses were conducted on a Cameca 7f-GEO secondary ion mass spectrometer (SIMS) to record spatial δ 34S variability within the mats under different environmental conditions. Isotope measurements were made in a 2-dimensional grid for each incubation, documenting both lateral and vertical isotopic variation within the mats. Typical grids consisted of ˜400-800 individual measurements covering a lateral distance of ˜1 mm and a vertical depth of ˜5-15 mm. There is a large isotopic enrichment (˜10-20‰) in the uppermost mm of sulfide in those mats where [SO 4] was non-limiting (field and lab incubations at 80 mM). This is attributed to rapid recycling of

  17. The tricarboxylic acid cycle activity in cultured primary astrocytes is strongly accelerated by the protein tyrosine kinase inhibitor tyrphostin 23

    DEFF Research Database (Denmark)

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S

    2017-01-01

    Tyrphostin 23 (T23) is a well-known inhibitor of protein tyrosine kinases and has been considered as potential anti-cancer drug. T23 was recently reported to acutely stimulate the glycolytic flux in primary cultured astrocytes. To investigate whether T23 also affects the tricarboxylic acid (TCA...... production. In addition, T23-treatment strongly increased the molecular carbon labeling of the TCA cycle intermediates citrate, succinate, fumarate and malate, and significantly increased the incorporation of (13)C-labelling into the amino acids glutamate, glutamine and aspartate. These results clearly...... demonstrate that, in addition to glycolysis, also the mitochondrial TCA cycle is strongly accelerated after exposure of astrocytes to T23, suggesting that a protein tyrosine kinase may be involved in the regulation of the TCA cycle in astrocytes....

  18. Can we bet on negative emissions to achieve the 2°C target even under strong carbon cycle feedbacks?

    Science.gov (United States)

    Tanaka, K.; Yamagata, Y.; Yokohata, T.; Emori, S.; Hanaoka, T.

    2015-12-01

    Negative emission technologies such as Bioenergy with Carbon dioxide Capture and Storage (BioCCS) play an ever more crucial role in meeting the 2°C stabilization target. However, such technologies are currently at their infancy and their future penetrations may fall short of the scale required to stabilize the warming. Furthermore, the overshoot in the mid-century prior to a full realization of negative emissions would give rise to a risk because such a temporal but excessive warming above 2°C might amplify itself by strengthening climate-carbon cycle feedbacks. It has not been extensively assessed yet how carbon cycle feedbacks might play out during the overshoot in the context of negative emissions. This study explores how 2°C stabilization pathways, in particular those which undergo overshoot, can be influenced by carbon cycle feedbacks and asks their climatic and economic consequences. We compute 2°C stabilization emissions scenarios under a cost-effectiveness principle, in which the total abatement costs are minimized such that the global warming is capped at 2°C. We employ a reduced-complexity model, the Aggregated Carbon Cycle, Atmospheric Chemistry, and Climate model (ACC2), which comprises a box model of the global carbon cycle, simple parameterizations of the atmospheric chemistry, and a land-ocean energy balance model. The total abatement costs are estimated from the marginal abatement cost functions for CO2, CH4, N2O, and BC.Our preliminary results show that, if carbon cycle feedbacks turn out to be stronger than what is known today, it would incur substantial abatement costs to keep up with the 2°C stabilization goal. Our results also suggest that it would be less expensive in the long run to plan for a 2°C stabilization pathway by considering strong carbon cycle feedbacks because it would cost more if we correct the emission pathway in the mid-century to adjust for unexpectedly large carbon cycle feedbacks during overshoot. Furthermore, our

  19. The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO2 flux

    Directory of Open Access Journals (Sweden)

    M. J. Filipiak

    2009-01-01

    Full Text Available The effect of diurnal variations in sea surface temperature (SST on the air-sea flux of CO2 over the central Atlantic ocean and Mediterranean Sea (60 S–60 N, 60 W–45 E is evaluated for 2005–2006. We use high spatial resolution hourly satellite ocean skin temperature data to determine the diurnal warming (ΔSST. The CO2 flux is then computed using three different temperature fields – a foundation temperature (Tf, measured at a depth where there is no diurnal variation, Tf, plus the hourly ΔSST and Tf, plus the monthly average of the ΔSSTs. This is done in conjunction with a physically-based parameterisation for the gas transfer velocity (NOAA-COARE. The differences between the fluxes evaluated for these three different temperature fields quantify the effects of both diurnal warming and diurnal covariations. We find that including diurnal warming increases the CO2 flux out of this region of the Atlantic for 2005–2006 from 9.6 Tg C a−1 to 30.4 Tg C a−1 (hourly ΔSST and 31.2 Tg C a−1 (monthly average of ΔSST measurements. Diurnal warming in this region, therefore, has a large impact on the annual net CO2 flux but diurnal covariations are negligible. However, in this region of the Atlantic the uptake and outgassing of CO2 is approximately balanced over the annual cycle, so although we find diurnal warming has a very large effect here, the Atlantic as a whole is a very strong carbon sink (e.g. −920 Tg C a−1 Takahashi et al., 2002 making this is a small contribution to the Atlantic carbon budget.

  20. Diurnal Variation of Tropical Ice Cloud Microphysics: Evidence from Global Precipitation Measurement Microwave Imager Polarimetric Measurements

    Science.gov (United States)

    Gong, Jie; Zeng, Xiping; Wu, Dong L.; Li, Xiaowen

    2018-01-01

    The diurnal variation of tropical ice clouds has been well observed and examined in terms of the occurring frequency and total mass but rarely from the viewpoint of ice microphysical parameters. It accounts for a large portion of uncertainties in evaluating ice clouds' role on global radiation and hydrological budgets. Owing to the advantage of precession orbit design and paired polarized observations at a high-frequency microwave band that is particularly sensitive to ice particle microphysical properties, 3 years of polarimetric difference (PD) measurements using the 166 GHz channel of Global Precipitation Measurement Microwave Imager (GPM-GMI) are compiled to reveal a strong diurnal cycle over tropical land (30°S-30°N) with peak amplitude varying up to 38%. Since the PD signal is dominantly determined by ice crystal size, shape, and orientation, the diurnal cycle observed by GMI can be used to infer changes in ice crystal properties. Moreover, PD change is found to lead the diurnal changes of ice cloud occurring frequency and total ice mass by about 2 h, which strongly implies that understanding ice microphysics is critical to predict, infer, and model ice cloud evolution and precipitation processes.

  1. A model of the plasma flow and current in Saturn's polar ionosphere under conditions of strong Dungey cycle driving

    Directory of Open Access Journals (Sweden)

    C. M. Jackman

    2006-05-01

    Full Text Available We propose a simple model of the flow and currents in Saturn's polar ionosphere. This model is motivated by theoretical reasoning, and guided quantitatively by in situ field and flow data from space missions, ground-based IR Doppler measurements, and Hubble Space Telescope images. The flow pattern consists of components which represent (1 plasma sub-corotation in the middle magnetosphere region resulting from plasma pick-up and radial transport from internal sources; (2 the Vasyliunas-cycle of internal plasma mass-loss down the magnetospheric tail at higher latitudes; and (3 the polar Dungey-cycle flow driven by the solar wind interaction. Upstream measurements of the interplanetary magnetic field (IMF indicate the occurrence of both extended low-field rarefaction intervals with essentially negligible Dungey-cycle flow, and few-day high-field compression regions in which the Dungey-cycle voltage peaks at a few hundred kV. Here we model the latter conditions when the Dungey-cycle is active, advancing on previous axi-symmetric models which may be more directly applicable to quiet conditions. For theoretical convenience the overall flow pattern is constructed by adding together two components - a purely rotational flow similar to previous axi-symmetric models, and a sun-aligned twin vortex representing the dawn-dusk asymmetry effects associated with the Vasyliunas-and Dungey-cycle flows. We calculate the horizontal ionospheric current associated with the flow and the field-aligned current from its divergence. These calculations show that a sheet of upward-directed field-aligned current flows at the boundary of open field lines which is strongly modulated in local-time by the Dungey-cycle flows. We then consider implications of the field-aligned current for magnetospheric electron acceleration and aurorae using two plasma source populations (hot outer magnetospheric electrons and cool dense magnetosheath electrons. Both sources display a strong dawn

  2. Diurnal variations from muon data at Takeyama underground station

    Science.gov (United States)

    Takahashi, K.; Imai, K.; Imai, T.; Kudo, S.; Wada, M.

    1985-01-01

    An underground station, Takeyama, is introduced, and some results of the solar diurnal and semi-diurnal variations for the period between 1967 and 1984 are presented. There are clear tendencies of double and single solar cycle variations in the daily variations which are in good accord with those detected by other underground and neutron monitor observations.

  3. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  4. Coordinated activation of PTA-ACS and TCA cycles strongly reduces overflow metabolism of acetate in Escherichia coli.

    Science.gov (United States)

    Peebo, Karl; Valgepea, Kaspar; Nahku, Ranno; Riis, Gethe; Oun, Mikk; Adamberg, Kaarel; Vilu, Raivo

    2014-06-01

    Elimination of acetate overflow in aerobic cultivation of Escherichia coli would improve many bioprocesses as acetate accumulation in the growth environment leads to numerous negative effects, e.g. loss of carbon, inhibition of growth, target product synthesis, etc. Despite many years of studies, the mechanism and regulation of acetate overflow are still not completely understood. Therefore, we studied the growth of E. coli K-12 BW25113 and several of its mutant strains affecting acetate-related pathways using the continuous culture method accelerostat (A-stat) at various specific glucose consumption rates with the aim of diminishing acetate overflow. Absolute quantitative exo-metabolome and proteome analyses coupled to metabolic flux analysis enabled us to demonstrate that onset of acetate overflow can be postponed and acetate excretion strongly reduced in E. coli by coordinated activation of phosphotransacetylase-acetyl-CoA synthetase (PTA-ACS) and tricarboxylic acid (TCA) cycles. Fourfold reduction of acetate excretion (2 vs. 8 % from total carbon) at fastest growth compared to wild type was achieved by deleting the genes responsible for inactivation of acetyl-CoA synthetase protein (pka) and TCA cycle regulator arcA. The Δpka ΔarcA strain did not accumulate any other detrimental by-product besides acetate and showed identical μ max and only ~5 % lower biomass yield compared to wild type. We conclude that a fine-tuned coordination between increasing the recycling capabilities of acetate in the PTA-ACS node through a higher concentration of active acetate scavenging Acs protein and downstream metabolism throughput in the TCA cycle is necessary for diminishing overflow metabolism of acetate in E. coli and achieving higher target product production in bioprocesses.

  5. Diurnal variations of tritium uptake by plants

    International Nuclear Information System (INIS)

    Hettinger, M.; Diabate, S.; Strack, S.

    1991-02-01

    The influence of the diurnal cycle is important for the behaviour of environmental tritium in the vegetation. A mathematical model has been used to calculate the deposition of tritium in plants as a function of diurnal variations of climatic parameters. The necessary physiological parameters (relationship of net photosynthesis and growth) were derived from growth experiments for tomatoes and maize. In chamber experiments, tomato and maize plants were exposed to tritium with natural diurnal variations of the climatic conditions. Within the range of standard deviations the measured concentrations of tritium in tissue free water of tomatoes correspond well to the estimated values. Furthermore, the incorporation into non-exchangeable organically bound tritium (OBT nx) can be sufficiently modelled and explained. There are deviations from the estimated concentrations in some parts of maize leaves. (orig.) [de

  6. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  7. Ciclo diário e semidiário de precipitação na costa norte do Brasil Diurnal and semidiurnal rainfall cycle over north coastland of Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio Moisés Santos Silva

    2013-03-01

    Full Text Available Estudou-se o ciclo diário e o ciclo semidiário da precipitação na região costeira do Norte do Brasil. Usou-se 13 anos de dados ininterruptos de precipitação estimados através do algoritmo 3B42_V6 do projeto TRMM. Os ciclos foram analisados por quadrimestres. Para obter informações sobre amplitude, fase e fração de variância de cada ciclo, utilizou-se a análise harmônica do ciclo composto no período de 24 horas para cada quadrimestre. Regiões mais próximas da costa apresentaram ciclos modulados por mecanismos oceânicos e, portanto, tendem a apresentar o máximo de precipitação no início da manhã e a noite. Regiões mais afastadas da costa apresentaram máximos às 2100 UTC (17:00 HL em função dos mecanismos de convecção local. A região Nordeste do Pará apresentou as maiores amplitudes de precipitação. Durante o quadrimestre de janeiro a abril observou-se as maiores taxas de precipitação. Não há variações sazonais significativas na fase dos ciclos. Os dois harmônicos correspondem a cerca de 80% do total da variância diária dos dados. No final, algumas sugestões de trabalhos futuros e aplicabilidade dos dados do 3B42_V6 são discutidas.The diurnal and semidiurnal rainfall cycles observed over the Brazilian North coastland were studied. A 13 years rainfall dataset derived by the 3B42_V6 algorithm was used. To obtain the amplitude, phase, and variance of each cycle the harmonic analysis was applied to the mean rainfall of 24 hours. Coastlands areas showed cycles modulated by oceanic mechanisms, thus the maximum rainfall was observed at early-morning and nighttime. Inland regions exhibited maximum rainfall at 2100 UTC (17:00 LST due the local convection mechanism. The highest amplitude of precipitation was observed over the Northeast of the Pará State. The highest rainfall rates were observed during January to April period. The phase of each cycle do not presented significant seasonal variation. The diurnal

  8. The Role of Nitric Oxide in Memory is Modulated by Diurnal Time

    Directory of Open Access Journals (Sweden)

    Stephanie L. Gage

    2014-04-01

    Full Text Available Nitric oxide (NO is thought to play an important neuromodulatory role in the olfactory system. This modulation has been suggested to be particularly important for olfactory learning and memory in the antennal lobe (the primary olfactory network in invertebrates. We are using the hawkmoth, Manduca sexta, to further investigate the role of NO in olfactory memory. Recent findings suggest that NO affects short-term memory traces and that NO concentration fluctuates with the light cycle. This gives rise to the hypothesis that NO may be involved in the connection between memory and circadian rhythms. In this study, we explore the role of diurnal time and NO in memory by altering the time of day when associative-olfactory conditioning is performed. We find a strong effect of NO on short-term memory, and two surprising effects of diurnal time. We find that (1 at certain time points, NO affects longer traces of memory in addition to short-term memory, and (2 when conditioning is performed close to the light cycle switches—both from light to dark and dark to light—NO does not significantly affect memory at all. These findings suggest an intriguing functional role for NO in olfactory conditioning that is modulated as a function of diurnal time.

  9. Diurnal and spatial variation of remotely sensed precipitation over Indian region

    Science.gov (United States)

    Rajan, D.; Iyengar, G. R.; Mitra, A. K.

    2016-05-01

    The climate of India is dominated by monsoon systems. The remotely sensed estimates obtained from the Tropical Rainfall Measuring Mission (TRMM) are used to examine the most of the Indian monsoon systems. This study deals with the diurnal and spatial variation of precipitation over the Indian region. The precipitation data from TRMM Multi-satellite Precipitation Analysis (TMPA), blended from a variety of sources (including rain gauges over land) and having both daily and 3- hourly output are being used for evaluation of the Numerical Weather Prediction models Basu (2007) of National Centre for Medium Range Weather Forecasting. The precipitation obtained from TRMM 3B42 for this study period has a spatial resolution of 0.25º X 0.25º latitude-longitude. The 3-hourly averaged values are centered at the middle of each 3 hr period. South Asian regions are dominated by seasonal climatic fluctuations and the major rainy season is the southwest monsoon season. In addition to the seasonal fluctuations, Indian summer monsoon is modulated by diurnal fluctuations; nature of diurnal variation of rainfall varies from place to place and depends upon the locations, topography of the region. Diurnal variation of rain-rate, frequency of rain, conditional rain rate, and maximum and minimum rain occurrence is studied. Over Indian tropical region, maximum rainfall over land and Bay of Bengal regions is observed during the late-afternoon and early-morning period, respectively. Drizzle or less rainfall occur frequently in the morning over most land areas, whereas convective activity occurs during the afternoon. The model predicted diurnal cycle of precipitation peaks too early (by ~3h) and the amplitude is too strong over Indian land region and tropical ocean region.

  10. Diurnal Temperature Cycles in Shallow Water Pools

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Paaijmans, K.P.; Heusinkveld, B.G.

    2006-01-01

    Larvas of malaria mosquito species live close to the water surface in shallow waters, and are exposed to water temperatures which differ considerably from the air or bulk water temperature. The present research aims to obtain a sound physical insight into processes which determine the water

  11. Annual and diurnal african biomass burning temporal dynamics

    Directory of Open Access Journals (Sweden)

    G. Roberts

    2009-05-01

    Full Text Available Africa is the single largest continental source of biomass burning emissions. Here we conduct the first analysis of one full year of geostationary active fire detections and fire radiative power data recorded over Africa at 15-min temporal interval and a 3 km sub-satellite spatial resolution by the Spinning Enhanced Visible and Infrared Imager (SEVIRI imaging radiometer onboard the Meteosat-8 satellite. We use these data to provide new insights into the rates and totals of open biomass burning over Africa, particularly into the extremely strong seasonal and diurnal cycles that exist across the continent. We estimate peak daily biomass combustion totals to be 9 and 6 million tonnes of fuel per day in the northern and southern hemispheres respectively, and total fuel consumption between February 2004 and January 2005 is estimated to be at least 855 million tonnes. Analysis is carried out with regard to fire pixel temporal persistence, and we note that the majority of African fires are detected only once in consecutive 15 min imaging slots. An investigation of the variability of the diurnal fire cycle is carried out with respect to 20 different land cover types, and whilst differences are noted between land covers, the fire diurnal cycle characteristics for most land cover type are very similar in both African hemispheres. We compare the Fire Radiative Power (FRP derived biomass combustion estimates to burned-areas, both at the scale of individual fires and over the entire continent at a 1-degree scale. Fuel consumption estimates are found to be less than 2 kg/m2 for all land cover types noted to be subject to significant fire activity, and for savanna grasslands where literature values are commonly reported the FRP-derived median fuel consumption estimate of 300 g/m2 is well within commonly quoted values. Meteosat-derived FRP data of the type presented here is now available freely to interested users continuously and in near

  12. Diurnal changes in ocean color sensed in satellite imagery

    Science.gov (United States)

    Arnone, Robert; Vandermuelen, Ryan; Soto, Inia; Ladner, Sherwin; Ondrusek, Michael; Yang, Haoping

    2017-07-01

    Measurements of diurnal changes in ocean color in turbid coastal regions in the Gulf of Mexico were characterized using above water spectral radiometry from a National Aeronautics and Space Administration (aerosol robotic network-WaveCIS CSI-06) site that can provide 8 to 10 observations per day. Satellite capability to detect diurnal changes in ocean color was characterized using hourly overlapping afternoon orbits of the visual infrared imaging radiometer suite (VIIRS) Suomi National Polar-orbiting Partnership ocean color sensor and validated with in situ observations. The monthly cycle of diurnal changes was investigated for different water masses using VIIRS overlaps. Results showed the capability of satellite observations to monitor hourly color changes in coastal regions that can be impacted by vertical movement of optical layers, in response to tides, resuspension, and river plume dispersion. The spatial variability of VIIRS diurnal changes showed the occurrence and displacement of phytoplankton blooming and decaying processes. The diurnal change in ocean color was above 20%, which represents a 30% change in chlorophyll-a. Seasonal changes in diurnal ocean color for different water masses suggest differences in summer and winter responses to surface processes. The diurnal changes observed using satellite ocean color can be used to define the following: surface processes associated with biological activity, vertical changes in optical depth, and advection of water masses.

  13. Diurnal variability of inner-shelf circulation in the lee of a cape under upwelling conditions

    Science.gov (United States)

    Lamas, L.; Peliz, A.; Dias, J.; Oliveira, P. B.; Angélico, M. M.; Castro, J. J.; Fernandes, J. N.; Trindade, A.; Cruz, T.

    2017-07-01

    The nearshore circulation in the lee of a cape under upwelling conditions was studied using in-situ data from 3 consecutive summers (2006-2008). Focus was given to a period between 20 July and 04 August 2006 to study the diurnal variability of the cross-shelf circulation. This period was chosen because it had a steady upwelling-favourable wind condition modulated by a diurnal cycle much similar to sea breeze. The daily variability of the observed cross-shelf circulation consisted of three distinct periods: a morning period with a 3-layer vertical structure with onshore velocities at mid-depth, a mid-day period where the flow is reversed and has a 2-layer structure with onshore velocities at the surface and offshore flow below, and, lastly, in the evening, a 2-layer period with intensified offshore velocities at the surface and onshore flow at the bottom. The observed cross-shelf circulation showed a peculiar vertical shape and diurnal variability different from several other systems described in literature. We hypothesize that the flow reversal of the cross-shelf circulation results as a response to the rapid change of the wind magnitude and direction at mid-day with the presence of the cape north of the mooring site influencing this response. A numerical modelling experiment exclusively forced by winds simulated successfully most of the circulation at the ADCP site, especially the mid-day reversal and the evening's upwelling-type structure. This supports the hypothesis that the cross-shelf circulation at diurnal timescales is mostly wind-driven. By analysing the 3D circulation in the vicinity of Cape Sines we came to the conclusion that the diurnal variability of the wind and the flow interaction with topography are responsible for the circulation variability at the ADCP site, though only a small region in the south of the cape showed a similar diurnal variability. The fact that the wind diurnally undergoes relaxation and intensification strongly affects the

  14. Diurnal variation of tropospheric temperature at a tropical station

    Directory of Open Access Journals (Sweden)

    K. Revathy

    2001-08-01

    Full Text Available The vertical velocity in the troposphere-lower stratosphere region measured using MST radar has been utilized to evaluate the temperature profile in the region. The diurnal variation of the tropospheric temperature on one day in August 1998 at the tropical station Gadanki (13.5° N, 79.2° E has been studied using the MST radar technique. The diurnal variation of the temperature revealed a prominent diurnal variation with the peak in the afternoon hours increasingly delayed in altitude. The tropopause temperature and altitude exhibited a clear diurnal cycle.Key words. Atmospheric composition and structure (pressure, density and temperature; troposphere - composition and chemistry; instruments and technique

  15. Counterintuitive angular shifts in the photoelectron momentum distribution for atoms in strong few-cycle circularly polarized laser pulses

    DEFF Research Database (Denmark)

    Martiny, Christian; Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2009-01-01

    We solve the three-dimensional time-dependent Schrödinger equation for a three-cycle circularly polarized laser pulse interacting with an atom. The photoelectron momentum distributions show counterintuitive shifts, similar to those observed in a recent experiment (Eckle et al 2008 Science 322 1525...

  16. Hydration status and diurnal trophic interactions shape microbial community function in desert biocrusts

    Science.gov (United States)

    Kim, Minsu; Or, Dani

    2017-12-01

    Biological soil crusts (biocrusts) are self-organised thin assemblies of microbes, lichens, and mosses that are ubiquitous in arid regions and serve as important ecological and biogeochemical hotspots. Biocrust ecological function is intricately shaped by strong gradients of water, light, oxygen, and dynamics in the abundance and spatial organisation of the microbial community within a few millimetres of the soil surface. We report a mechanistic model that links the biophysical and chemical processes that shape the functioning of biocrust representative microbial communities that interact trophically and respond dynamically to cycles of hydration, light, and temperature. The model captures key features of carbon and nitrogen cycling within biocrusts, such as microbial activity and distribution (during early stages of biocrust establishment) under diurnal cycles and the associated dynamics of biogeochemical fluxes at different hydration conditions. The study offers new insights into the highly dynamic and localised processes performed by microbial communities within thin desert biocrusts.

  17. Diurnal variations of summertime precipitation over the Tibetan Plateau in relation to orographically-induced regional circulations

    International Nuclear Information System (INIS)

    Liu Xiaodong; Bai Aijuan; Liu Changhai

    2009-01-01

    The diurnal patterns of variation of summertime precipitation over the Tibetan Plateau were first investigated using the TRMM multi-satellite precipitation analysis product for five summer seasons (i.e. June to August for 2002-2006). Both hourly precipitation amount and precipitation frequency exhibit pronounced daily variability with an overall late-afternoon-evening maximum and a dominant morning minimum. A notable exception is the prevalent nocturnal maximum around the periphery of the Plateau. In terms of the normalized harmonic amplitude, the diurnal signal shows significant regional contrast with the strongest manifestation over the central Plateau and the weakest near the periphery. This remarkable spatial dependence in daily rainfall cycles is clear evidence of orographic and heterogeneous land-surface impacts on convective development. Using six-hourly NCEP FNL data, we then examined the diurnal variability in the atmospheric circulation and thermodynamics in this region. The results show that the Plateau heats (cools) the overlying atmosphere during the day (night) more than the surrounding areas, and as a consequence a relatively stronger confluent circulation in this region occurs during the day than during the night, consistent with the diurnal rainfall cycles. Moreover, the regions with large low-level convergence and upper-level divergence correspond to the strong diurnal rainfall variations. The reversed daily alterations of convergence-divergence patterns in the vicinity of the Plateau edges are in agreement with the observed nighttime rainfall peak therein. This study further demonstrates the importance of the Tibetan Plateau in regulating regional circulation and precipitation.

  18. Estimation of evaporation from equilibrium diurnal boundary layer humidity

    Science.gov (United States)

    Salvucci, G.; Rigden, A. J.; Li, D.; Gentine, P.

    2017-12-01

    Simplified conceptual models of the convective boundary layer as a well mixed profile of potential temperature (theta) and specific humidity (q) impinging on an initially stably stratified linear potential temperature profile have a long history in atmospheric sciences. These one dimensional representations of complex mixing are useful for gaining insights into land-atmosphere interactions and for prediction when state of the art LES approaches are infeasible. As previously shown (e.g. Betts), if one neglects the role of q in bouyancy, the framework yields a unique relation between mixed layer Theta, mixed layer height (h), and cumulative sensible heat flux (SH) throughout the day. Similarly assuming an initially q profile yields a simple relation between q, h, and cumulative latent heat flux (LH). The diurnal dynamics of theta and q are strongly dependent on SH and the initial lapse rates of theta (gamma_thet) and q (gamma q). In the estimation method proposed here, we further constrain these relations with two more assumptions: 1) The specific humidity is the same at the start of the period of boundary layer growth and at the collapse; and 2) Once the mixed layer reaches the LCL, further drying occurs proportionally to the deardorff convective velocity scale (omega) multiplied by q. Assumption (1) is based on the idea that below the cloud layer, there are no sinks of moisture within the mixed layer (neglecting lateral humidity divergence). Thus the net mixing of dry air aloft with evaporation from the surface must balance. Inclusion of the simple model of moisture loss above the LCL into the bulk-CBL model allows definition of an equilibrium humidity (q) condition at which the diurnal cycle of q repeats (i.e. additions of q from surface balance entrainment of dry air from above). Surprisingly, this framework allows estimation of LH from q, theta, and estimated net radiation by solving for the value of Evaporative Fraction (EF) for which the diurnal cycle of q

  19. A Diurnal Rhythm in Brown Adipose Tissue Causes Rapid Clearance and Combustion of Plasma Lipids at Wakening

    Directory of Open Access Journals (Sweden)

    Rosa van den Berg

    2018-03-01

    Full Text Available Summary: Many favorable metabolic effects have been attributed to thermogenic activity of brown adipose tissue (BAT. Yet, time of day has rarely been considered in this field of research. Here, we show that a diurnal rhythm in BAT activity regulates plasma lipid metabolism. We observed a high-amplitude rhythm in fatty acid uptake by BAT that synchronized with the light/dark cycle. Highest uptake was found at the onset of the active period, which coincided with high lipoprotein lipase expression and low angiopoietin-like 4 expression by BAT. Diurnal rhythmicity in BAT activity determined the rate at which lipids were cleared from the circulation, thereby imposing the daily rhythm in plasma lipid concentrations. In mice as well as humans, postprandial lipid excursions were nearly absent at waking. We anticipate that diurnal BAT activity is an important factor to consider when studying the therapeutic potential of promoting BAT activity. : van den Berg et al. show a strong circadian rhythm in fatty acid uptake by brown adipose tissue that peaks at wakening regardless of the light exposure period. Consequently, postprandial lipid handling by brown adipose tissue is highest at wakening, resulting in the lowest postprandial plasma lipid excursions. Keywords: circadian rhythm, diurnal rhythm, brown adipose tissue, triglycerides, fatty acids, lipoprotein lipase, angiopoietin-like 4, postprandial lipid response, APOE∗3-Leiden.CETP mice

  20. Spatial Evolution of a Strong Field of Few-cycle Light Beam in Dielectric Media with Induced Plasma Nonlinearity

    International Nuclear Information System (INIS)

    Stumpf, S A; Korolev, A A; Kozlov, S A

    2013-01-01

    The paper reports results of computer simulation of strong light beam propagation in dielectric media in case of plasma generation. We investigate an extra-broadening of radiation spectrum to a 'violet' wing of visible range. We show that the resulting pulse spectrum is represented by sequence of well-separated maximums, broadening as propagation distance increases. Experimental data are compared with simulation results, showing a good mutual correspondence of spectral representations

  1. Diurnal Regulation of Cellular Processes in the Cyanobacterium Synechocystis sp. Strain PCC 6803: Insights from Transcriptomic, Fluxomic, and Physiological Analyses.

    Science.gov (United States)

    Saha, Rajib; Liu, Deng; Hoynes-O'Connor, Allison; Liberton, Michelle; Yu, Jingjie; Bhattacharyya-Pakrasi, Maitrayee; Balassy, Andrea; Zhang, Fuzhong; Moon, Tae Seok; Maranas, Costas D; Pakrasi, Himadri B

    2016-05-03

    Synechocystis sp. strain PCC 6803 is the most widely studied model cyanobacterium, with a well-developed omics level knowledgebase. Like the lifestyles of other cyanobacteria, that of Synechocystis PCC 6803 is tuned to diurnal changes in light intensity. In this study, we analyzed the expression patterns of all of the genes of this cyanobacterium over two consecutive diurnal periods. Using stringent criteria, we determined that the transcript levels of nearly 40% of the genes in Synechocystis PCC 6803 show robust diurnal oscillating behavior, with a majority of the transcripts being upregulated during the early light period. Such transcripts corresponded to a wide array of cellular processes, such as light harvesting, photosynthetic light and dark reactions, and central carbon metabolism. In contrast, transcripts of membrane transporters for transition metals involved in the photosynthetic electron transport chain (e.g., iron, manganese, and copper) were significantly upregulated during the late dark period. Thus, the pattern of global gene expression led to the development of two distinct transcriptional networks of coregulated oscillatory genes. These networks help describe how Synechocystis PCC 6803 regulates its metabolism toward the end of the dark period in anticipation of efficient photosynthesis during the early light period. Furthermore, in silico flux prediction of important cellular processes and experimental measurements of cellular ATP, NADP(H), and glycogen levels showed how this diurnal behavior influences its metabolic characteristics. In particular, NADPH/NADP(+) showed a strong correlation with the majority of the genes whose expression peaks in the light. We conclude that this ratio is a key endogenous determinant of the diurnal behavior of this cyanobacterium. Cyanobacteria are photosynthetic microbes that use energy from sunlight and CO2 as feedstock. Certain cyanobacterial strains are amenable to facile genetic manipulation, thus enabling

  2. Three-dimensional modeling of the P. falciparum genome during the erythrocytic cycle reveals a strong connection between genome architecture and gene expression

    Science.gov (United States)

    Ay, Ferhat; Bunnik, Evelien M.; Varoquaux, Nelle; Bol, Sebastiaan M.; Prudhomme, Jacques; Vert, Jean-Philippe; Noble, William Stafford; Le Roch, Karine G.

    2014-01-01

    The development of the human malaria parasite Plasmodium falciparum is controlled by coordinated changes in gene expression throughout its complex life cycle, but the corresponding regulatory mechanisms are incompletely understood. To study the relationship between genome architecture and gene regulation in Plasmodium, we assayed the genome architecture of P. falciparum at three time points during its erythrocytic (asexual) cycle. Using chromosome conformation capture coupled with next-generation sequencing technology (Hi-C), we obtained high-resolution chromosomal contact maps, which we then used to construct a consensus three-dimensional genome structure for each time point. We observed strong clustering of centromeres, telomeres, ribosomal DNA, and virulence genes, resulting in a complex architecture that cannot be explained by a simple volume exclusion model. Internal virulence gene clusters exhibit domain-like structures in contact maps, suggesting that they play an important role in the genome architecture. Midway during the erythrocytic cycle, at the highly transcriptionally active trophozoite stage, the genome adopts a more open chromatin structure with increased chromosomal intermingling. In addition, we observed reduced expression of genes located in spatial proximity to the repressive subtelomeric center, and colocalization of distinct groups of parasite-specific genes with coordinated expression profiles. Overall, our results are indicative of a strong association between the P. falciparum spatial genome organization and gene expression. Understanding the molecular processes involved in genome conformation dynamics could contribute to the discovery of novel antimalarial strategies. PMID:24671853

  3. Three-dimensional modeling of the P. falciparum genome during the erythrocytic cycle reveals a strong connection between genome architecture and gene expression.

    Science.gov (United States)

    Ay, Ferhat; Bunnik, Evelien M; Varoquaux, Nelle; Bol, Sebastiaan M; Prudhomme, Jacques; Vert, Jean-Philippe; Noble, William Stafford; Le Roch, Karine G

    2014-06-01

    The development of the human malaria parasite Plasmodium falciparum is controlled by coordinated changes in gene expression throughout its complex life cycle, but the corresponding regulatory mechanisms are incompletely understood. To study the relationship between genome architecture and gene regulation in Plasmodium, we assayed the genome architecture of P. falciparum at three time points during its erythrocytic (asexual) cycle. Using chromosome conformation capture coupled with next-generation sequencing technology (Hi-C), we obtained high-resolution chromosomal contact maps, which we then used to construct a consensus three-dimensional genome structure for each time point. We observed strong clustering of centromeres, telomeres, ribosomal DNA, and virulence genes, resulting in a complex architecture that cannot be explained by a simple volume exclusion model. Internal virulence gene clusters exhibit domain-like structures in contact maps, suggesting that they play an important role in the genome architecture. Midway during the erythrocytic cycle, at the highly transcriptionally active trophozoite stage, the genome adopts a more open chromatin structure with increased chromosomal intermingling. In addition, we observed reduced expression of genes located in spatial proximity to the repressive subtelomeric center, and colocalization of distinct groups of parasite-specific genes with coordinated expression profiles. Overall, our results are indicative of a strong association between the P. falciparum spatial genome organization and gene expression. Understanding the molecular processes involved in genome conformation dynamics could contribute to the discovery of novel antimalarial strategies. © 2014 Ay et al.; Published by Cold Spring Harbor Laboratory Press.

  4. Arvicanthis ansorgei, a Novel Model for the Study of Sleep and Waking in Diurnal Rodents.

    Science.gov (United States)

    Hubbard, Jeffrey; Ruppert, Elisabeth; Calvel, Laurent; Robin-Choteau, Ludivine; Gropp, Claire-Marie; Allemann, Caroline; Reibel, Sophie; Sage-Ciocca, Dominique; Bourgin, Patrice

    2015-06-01

    Sleep neurobiology studies use nocturnal species, mainly rats and mice. However, because their daily sleep/wake organization is inverted as compared to humans, a diurnal model for sleep studies is needed. To fill this gap, we phenotyped sleep and waking in Arvicanthis ansorgei, a diurnal rodent widely used for the study of circadian rhythms. Video-electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG) recordings. Rodent sleep laboratory. Fourteen male Arvicanthis ansorgei, aged 3 mo. 12 h light (L):12 h dark (D) baseline condition, 24-h constant darkness, 6-h sleep deprivation. Wake and rapid eye movement (REM) sleep showed similar electrophysiological characteristics as nocturnal rodents. On average, animals spent 12.9 h ± 0.4 awake per 24-h cycle, of which 6.88 h ± 0.3 was during the light period. NREM sleep accounted for 9.63 h ± 0.4, which of 5.13 h ± 0.2 during dark period, and REM sleep for 89.9 min ± 6.7, which of 52.8 min ± 4.4 during dark period. The time-course of sleep and waking across the 12 h light:12 h dark was overall inverted to that observed in rats or mice, though with larger amounts of crepuscular activity at light and dark transitions. A dominant crepuscular regulation of sleep and waking persisted under constant darkness, showing the lack of a strong circadian drive in the absence of clock reinforcement by external cues, such as a running wheel. Conservation of the homeostatic regulation was confirmed with the observation of higher delta power following sustained waking periods and a 6-h sleep deprivation, with subsequent decrease during recovery sleep. Arvicanthis ansorgei is a valid diurnal rodent model for studying the regulatory mechanisms of sleep and so represents a valuable tool for further understanding the nocturnality/diurnality switch. © 2015 Associated Professional Sleep Societies, LLC.

  5. A model of the plasma flow and current in Saturn's polar ionosphere under conditions of strong Dungey cycle driving

    Directory of Open Access Journals (Sweden)

    C. M. Jackman

    2006-05-01

    Full Text Available We propose a simple model of the flow and currents in Saturn's polar ionosphere. This model is motivated by theoretical reasoning, and guided quantitatively by in situ field and flow data from space missions, ground-based IR Doppler measurements, and Hubble Space Telescope images. The flow pattern consists of components which represent (1 plasma sub-corotation in the middle magnetosphere region resulting from plasma pick-up and radial transport from internal sources; (2 the Vasyliunas-cycle of internal plasma mass-loss down the magnetospheric tail at higher latitudes; and (3 the polar Dungey-cycle flow driven by the solar wind interaction. Upstream measurements of the interplanetary magnetic field (IMF indicate the occurrence of both extended low-field rarefaction intervals with essentially negligible Dungey-cycle flow, and few-day high-field compression regions in which the Dungey-cycle voltage peaks at a few hundred kV. Here we model the latter conditions when the Dungey-cycle is active, advancing on previous axi-symmetric models which may be more directly applicable to quiet conditions. For theoretical convenience the overall flow pattern is constructed by adding together two components - a purely rotational flow similar to previous axi-symmetric models, and a sun-aligned twin vortex representing the dawn-dusk asymmetry effects associated with the Vasyliunas-and Dungey-cycle flows. We calculate the horizontal ionospheric current associated with the flow and the field-aligned current from its divergence. These calculations show that a sheet of upward-directed field-aligned current flows at the boundary of open field lines which is strongly modulated in local-time by the Dungey-cycle flows. We then consider implications of the field-aligned current for magnetospheric electron acceleration and aurorae using two plasma source populations (hot outer magnetospheric electrons and cool dense magnetosheath electrons. Both sources display a

  6. Diurnal Ensemble Surface Meteorology Statistics

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excel file containing diurnal ensemble statistics of 2-m temperature, 2-m mixing ratio and 10-m wind speed. This Excel file contains figures for Figure 2 in the...

  7. Arctic and Antarctic diurnal and seasonal variations of snow albedo from multiyear Baseline Surface Radiation Network measurements

    OpenAIRE

    Wang, Xianwei; Zender, Charles S

    2011-01-01

    This study analyzes diurnal and seasonal variations of snow albedo at four Baseline Surface Radiation Network stations in the Arctic and Antarctica from 2003 to 2008 to elucidate similarities and differences in snow albedo diurnal cycles across geographic zones and to assess how diurnal changes in snow albedo affect the surface energy budget. At the seasonal scale, the daily albedo for the perennial snow at stations South Pole and Georg von Neumayer in Antarctica has a similar symmetric varia...

  8. Specific diurnal EMG activity pattern observed in occlusal collapse patients: relationship between diurnal bruxism and tooth loss progression.

    Directory of Open Access Journals (Sweden)

    Shigehisa Kawakami

    Full Text Available AIM: The role of parafunctional masticatory muscle activity in tooth loss has not been fully clarified. This study aimed to reveal the characteristic activity of masseter muscles in bite collapse patients while awake and asleep. MATERIALS AND METHODS: Six progressive bite collapse patients (PBC group, six age- and gender-matched control subjects (MC group, and six young control subjects (YC group were enrolled. Electromyograms (EMG of the masseter muscles were continuously recorded with an ambulatory EMG recorder while patients were awake and asleep. Diurnal and nocturnal parafunctional EMG activity was classified as phasic, tonic, or mixed using an EMG threshold of 20% maximal voluntary clenching. RESULTS: Highly extended diurnal phasic activity was observed only in the PBC group. The three groups had significantly different mean diurnal phasic episodes per hour, with 13.29±7.18 per hour in the PBC group, 0.95±0.97 per hour in the MC group, and 0.87±0.98 per hour in the YC group (p<0.01. ROC curve analysis suggested that the number of diurnal phasic episodes might be used to predict bite collapsing tooth loss. CONCLUSION: Extensive bite loss might be related to diurnal masticatory muscle parafunction but not to parafunction during sleep. CLINICAL RELEVANCE SCIENTIFIC RATIONALE FOR STUDY: Although mandibular parafunction has been implicated in stomatognathic system breakdown, a causal relationship has not been established because scientific modalities to evaluate parafunctional activity have been lacking. PRINCIPAL FINDINGS: This study used a newly developed EMG recording system that evaluates masseter muscle activity throughout the day. Our results challenge the stereotypical idea of nocturnal bruxism as a strong destructive force. We found that diurnal phasic masticatory muscle activity was most characteristic in patients with progressive bite collapse. PRACTICAL IMPLICATIONS: The incidence of diurnal phasic contractions could be used for

  9. Heliospheric Modulation of Galactic Cosmic Rays; Diurnal Variability Abstract Details

    Science.gov (United States)

    Kalu, D. F.; Okpala, K. C.

    2017-12-01

    We have studied the variability of Cosmic rays flux during solar quiet days at mid and high latitudes in the Northern Hemisphere. By using the five (5) quietest days for each month and the five disturbed days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1999-2015, which covers part of cycles 23, and cycle 24. This study seeks to understand the heliospheric contribution to the variation of these Cosmic rays on quietest days, three stations (Inuvik, Moscow, Rome) Neutron Monitors were employed. This study seeks to understand the important features of the high latitude and mid latitude diurnal wave, and how solar and geomagnetic activity may be influencing the wave characteristics. Cosmic ray wave characteristics were obtained by discrete Fourier transform (DFT). The mean, diurnal amplitude, phase and dispersion for each month's diurnal wave were calculated and profiled. There was clear indication that the terrestrial effect on the variability of the monthly mean was more associated with geomagnetic activity rather than rigidity of the cosmic rays. Correlation of the time series of these wave characteristic with solar and geomagnetic activity index showed better association with solar activity.

  10. Diurnal, semidiurnal, and fortnightly tidal components in orthotidal proglacial rivers.

    Science.gov (United States)

    Briciu, Andrei-Emil

    2018-02-22

    The orthotidal rivers are a new concept referring to inland rivers influenced by gravitational tides through the groundwater tides. "Orthotidal signals" is intended to describe tidal signals found in inland streamwaters (with no oceanic input); these tidal signals were locally generated and then exported into streamwaters. Here, we show that orthotidal signals can be found in proglacial rivers due to the gravitational tides affecting the glaciers and their surrounding areas. The gravitational tides act on glacier through earth and atmospheric tides, while the subglacial water is affected in a manner similar to the groundwater tides. We used the wavelet analysis in order to find tidally affected streamwaters. T_TIDE analyses were performed for discovering the tidal constituents. Tidal components with 0.95 confidence level are as follows: O1, PI1, P1, S1, K1, PSI1, M2, T2, S2, K2, and MSf. The amplitude of the diurnal tidal constituents is strongly influenced by the daily thermal cycle. The average amplitude of the semidiurnal tidal constituents is less altered and ranges from 0.0007 to 0.0969 m. The lunisolar synodic fortnightly oscillation, found in the time series of the studied river gauges, is a useful signal for detecting orthotidal rivers when using noisier data. The knowledge of the orthotidal oscillations is useful for modeling fine resolution changes in rivers.

  11. Diurnal Mood Fluctuation and Age.

    Science.gov (United States)

    Templer, Donald I.; And Others

    1981-01-01

    Studied the nature of diurnal mood variations in 173 persons aged 13 to 82. Results indicated adolescents and young adults tended to report better moods toward evening while middle-aged and elderly persons reported better moods in the morning. Limited findings suggest the opposite trends for depressed psychiatric patients (Author/JA)

  12. Optical Parametric Amplification Techniques for the Generation of High-Energy Few-Optical-Cycles IR Pulses for Strong Field Applications

    Directory of Open Access Journals (Sweden)

    Anna G. Ciriolo

    2017-03-01

    Full Text Available Over the last few decades, the investigation of ultrafast phenomena occurring in atoms, molecules and solid-state systems under a strong-field regime of light-matter interaction has attracted great attention. The increasing request for a suitable optical technology is significantly boosting the development of powerful ultrafast laser sources. In this framework, Optical Parametric Amplification (OPA is currently becoming a leading solution for applications in high-power ultra-broadband light burst generation. The main advantage provided by the OPA scheme consists of the possibility of exploring spectral ranges that are inaccessible by other laser technologies, as the InfraRed (IR window. In this paper, we will give an overview on recent progress in the development of high-power few-optical-cycle parametric amplifiers in the near-IR and in the mid-IR spectral domain. In particular, the design of the most advanced OPA implementations is provided, containing a discussion on the key technical aspects. In addition, a review on their application to the study of strong-field ultrafast physical processes is reported.

  13. Diurnal variations in water vapor over Central and South America

    Science.gov (United States)

    Meza, Amalia; Mendoza, Luciano; Clara, Bianchi

    2017-04-01

    Diurnal variations in atmospheric integrated water vapor (IWV) are studied employing IWV estimates, with a 30 minutes sampling rate, derived from Global Navigation Satellite Systems (GNSS) observations during the period 2007-2013. The analysis was performed in 70 GNSS tracking sites (GPS + GLONASS) belonging to Central and South America, which have more than 5 years of data. The selected area involves different climate types, from polar to tropical, and diverse relieves, therefore the patterns of IWV diurnal variations are very different for each station. There are many processes that could induce diurnal variations in atmospheric water vapor (Dai et al, 1999 a,b), the most relevant causes are: surface evapotranspiration, atmospheric large-scale vertical motion, atmospheric low-level moisture convergence and precipitation and vertical mixing (which affects the vertical distribution of water vapor but does not affect the IWV). Firstly, our work study the main characteristics of the IWV diurnal cycle (and for surface temperature, T) obtained for all stations together, using Principal Component Analysis (PCA). First and second PCA modes highlight the global main behaviors of IWV variability for all stations. The first mode on IWV represent the 70% of the variability and could be related to the surface evapotranspiration, while the second mode (27 % of the variability) is practically in counter phase to T variability (its first mode represent the 97% of the variability), therefore this mode could be related to breeze regime. Then, every station is separately analyzed and seasonal and local variations (relative to the relives) are detected, these results spotlight, among other characteristics, the sea and mountain breeze regime. This presentation shows the first analysis of IWV diurnal cycle performed over Central and South America and another original characteristic is PCA technique employed to infer the results. Reference: Dai, A., K. E. Trenberth, and T. R. Karl

  14. Comparative Analysis of Vertebrate Diurnal/Circadian Transcriptomes.

    Directory of Open Access Journals (Sweden)

    Greg Boyle

    Full Text Available From photosynthetic bacteria to mammals, the circadian clock evolved to track diurnal rhythms and enable organisms to anticipate daily recurring changes such as temperature and light. It orchestrates a broad spectrum of physiology such as the sleep/wake and eating/fasting cycles. While we have made tremendous advances in our understanding of the molecular details of the circadian clock mechanism and how it is synchronized with the environment, we still have rudimentary knowledge regarding its connection to help regulate diurnal physiology. One potential reason is the sheer size of the output network. Diurnal/circadian transcriptomic studies are reporting that around 10% of the expressed genome is rhythmically controlled. Zebrafish is an important model system for the study of the core circadian mechanism in vertebrate. As Zebrafish share more than 70% of its genes with human, it could also be an additional model in addition to rodent for exploring the diurnal/circadian output with potential for translational relevance. Here we performed comparative diurnal/circadian transcriptome analysis with established mouse liver and other tissue datasets. First, by combining liver tissue sampling in a 48h time series, transcription profiling using oligonucleotide arrays and bioinformatics analysis, we profiled rhythmic transcripts and identified 2609 rhythmic genes. The comparative analysis revealed interesting features of the output network regarding number of rhythmic genes, proportion of tissue specific genes and the extent of transcription factor family expression. Undoubtedly, the Zebrafish model system will help identify new vertebrate outputs and their regulators and provides leads for further characterization of the diurnal cis-regulatory network.

  15. Diurnal tides in the Arctic Ocean

    Science.gov (United States)

    Kowalik, Z.; Proshutinsky, A. Y.

    1993-01-01

    A 2D numerical model with a space grid of about 14 km is applied to calculate diurnal tidal constituents K(1) and O(1) in the Arctic Ocean. Calculated corange and cotidal charts show that along the continental slope, local regions of increased sea level amplitude, highly variable phase and enhanced currents occur. It is shown that in these local regions, shelf waves (topographic waves) of tidal origin are generated. In the Arctic Ocean and Northern Atlantic Ocean more than 30 regions of enhanced currents are identified. To prove the near-resonant interaction of the diurnal tides with the local bottom topography, the natural periods of oscillations for all regions have been calculated. The flux of energy averaged over the tidal period depicts the gyres of semitrapped energy, suggesting that the shelf waves are partially trapped over the irregularities of the bottom topography. It is shown that the occurrence of near-resonance phenomenon changes the energy flow in the tidal waves. First, the flux of energy from the astronomical sources is amplified in the shelf wave regions, and afterwards the tidal energy is strongly dissipated in the same regions.

  16. Concerted diurnal patterns in riverine nutrient concentrations and physical conditions.

    Science.gov (United States)

    Scholefield, David; Le Goff, Thierry; Braven, Jim; Ebdon, Les; Long, Terry; Butler, Mark

    2005-05-15

    Several long-term sets of hourly nitrate concentration data were obtained through deployment of a nitrate sensor in an upper reach of the River Taw, a small moorland-fed river in the South West of the UK. Examination of the data obtained during periods of low flow and the absence of rainfall in the catchment revealed the presence of marked diurnal cycles, which were in concert and negatively correlated with diurnal cycles in water temperature. After verifying that these cycles were natural, an intensive 90-h field monitoring campaign was conducted, in which river water was sampled hourly and immediately analysed in the laboratory for molybdate-reactive phosphorus (P), nitrate, nitrite, ammonium, and pH. Coincident measurements of water temperature, river discharge and solar energy were also taken at, or close to, the site. All measurements revealed diurnal patterns and all patterns were concerted. The cycles of P, nitrate, nitrite, and discharge had two maxima and minima per 24 h, while the cycle of water temperature had one, with a maximum at 20.00 and a minimum at 08.00. The amplitudes of the cycles of P and nitrate were each about 30% of the mean values, while the amplitude of the nitrite cycle was as great as 80% of the mean value on occasions. Both biological and physical mechanisms for the cycling could operate through water temperature and/or incident radiation to account for the observed phenomenon, but there remains uncertainty of which is the more important. The observations have important implications for both the accuracy of pollution assessment in rivers and the physiological rhythms of riverine organisms.

  17. Concerted diurnal patterns in riverine nutrient concentrations and physical conditions

    International Nuclear Information System (INIS)

    Scholefield, David; Le Goff, Thierry; Braven, Jim; Ebdon, Les; Long, Terry; Butler, Mark

    2005-01-01

    Several long-term sets of hourly nitrate concentration data were obtained through deployment of a nitrate sensor in an upper reach of the River Taw, a small moorland-fed river in the South West of the UK. Examination of the data obtained during periods of low flow and the absence of rainfall in the catchment revealed the presence of marked diurnal cycles, which were in concert and negatively correlated with diurnal cycles in water temperature. After verifying that these cycles were natural, an intensive 90-h field monitoring campaign was conducted, in which river water was sampled hourly and immediately analysed in the laboratory for molybdate-reactive phosphorus (P), nitrate, nitrite, ammonium, and pH. Coincident measurements of water temperature, river discharge and solar energy were also taken at, or close to, the site. All measurements revealed diurnal patterns and all patterns were concerted. The cycles of P, nitrate, nitrite, and discharge had two maxima and minima per 24 h, while the cycle of water temperature had one, with a maximum at 20.00 and a minimum at 08.00. The amplitudes of the cycles of P and nitrate were each about 30% of the mean values, while the amplitude of the nitrite cycle was as great as 80% of the mean value on occasions. Both biological and physical mechanisms for the cycling could operate through water temperature and/or incident radiation to account for the observed phenomenon, but there remains uncertainty of which is the more important. The observations have important implications for both the accuracy of pollution assessment in rivers and the physiological rhythms of riverine organisms

  18. Radiation balance at the surface in the city of São Paulo, Brazil: diurnal and seasonal variations

    NARCIS (Netherlands)

    Ferreira, M.J.; Oliveira, de A.P.; Soares, J.; Codato, G.; Wilde Barbaro, E.; Escobedo, J.F.

    2012-01-01

    The main goal of this work is to describe the diurnal and seasonal variations of the radiation balance components at the surface in the city of São Paulo based on observations carried out during 2004. Monthly average hourly values indicate that the amplitudes of the diurnal cycles of net radiation

  19. The influence of sea- and land-breeze circulations on the diurnal variability in precipitation over a tropical island

    Directory of Open Access Journals (Sweden)

    L. Zhu

    2017-11-01

    Full Text Available This study examines the diurnal variation in precipitation over Hainan Island in the South China Sea using gauge observations from 1951 to 2012 and Climate Prediction Center MORPHing technique (CMORPH satellite estimates from 2006 to 2015, as well as numerical simulations. The simulations are the first to use climatological mean initial and lateral boundary conditions to study the dynamic and thermodynamic processes (and the impacts of land–sea breeze circulations that control the rainfall distribution and climatology. Precipitation is most significant from April to October and exhibits a strong diurnal cycle resulting from land–sea breeze circulations. More than 60 % of the total annual precipitation over the island is attributable to the diurnal cycle with a significant monthly variability. The CMORPH and gauge datasets agree well, except that the CMORPH data underestimate precipitation and have a 1 h peak delay. The diurnal cycle of the rainfall and the related land–sea breeze circulations during May and June were well captured by convection-permitting numerical simulations with the Weather Research and Forecasting (WRF model, which were initiated from a 10-year average ERA-Interim reanalysis. The simulations have a slight overestimation of rainfall amounts and a 1 h delay in peak rainfall time. The diurnal cycle of precipitation is driven by the occurrence of moist convection around noontime owing to low-level convergence associated with the sea-breeze circulations. The precipitation intensifies rapidly thereafter and peaks in the afternoon with the collisions of sea-breeze fronts from different sides of the island. Cold pools of the convective storms contribute to the inland propagation of the sea breeze. Generally, precipitation dissipates quickly in the evening due to the cooling and stabilization of the lower troposphere and decrease of boundary layer moisture. Interestingly, the rather high island orography is not a

  20. High-Resolution Profiling of a Synchronized Diurnal Transcriptome from Chlamydomonas reinhardtii Reveals Continuous Cell and Metabolic Differentiation.

    Science.gov (United States)

    Zones, James Matt; Blaby, Ian K; Merchant, Sabeeha S; Umen, James G

    2015-10-01

    The green alga Chlamydomonas reinhardtii is a useful model organism for investigating diverse biological processes, such as photosynthesis and chloroplast biogenesis, flagella and basal body structure/function, cell growth and division, and many others. We combined a highly synchronous photobioreactor culture system with frequent temporal sampling to characterize genome-wide diurnal gene expression in Chlamydomonas. Over 80% of the measured transcriptome was expressed with strong periodicity, forming 18 major clusters. Genes associated with complex structures and processes, including cell cycle control, flagella and basal bodies, ribosome biogenesis, and energy metabolism, all had distinct signatures of coexpression with strong predictive value for assigning and temporally ordering function. Importantly, the frequent sampling regime allowed us to discern meaningful fine-scale phase differences between and within subgroups of genes and enabled the identification of a transiently expressed cluster of light stress genes. Coexpression was further used both as a data-mining tool to classify and/or validate genes from other data sets related to the cell cycle and to flagella and basal bodies and to assign isoforms of duplicated enzymes to their cognate pathways of central carbon metabolism. Our diurnal coexpression data capture functional relationships established by dozens of prior studies and are a valuable new resource for investigating a variety of biological processes in Chlamydomonas and other eukaryotes. © 2015 American Society of Plant Biologists. All rights reserved.

  1. Diurnal variation of summer precipitation over the Tibetan Plateau. A cloud-resolving simulation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jianyu; Zhang, Bing; Wang, Minghuan [China Meteorological Administration, Wuhan (China). Wuhan Inst. of Heavy Rain; Wang, Huijuan [Weather Modification Office of Hubei Province, Wuhan (China)

    2012-07-01

    In this study, the Weather Research and Forecasting model was used to simulate the diurnal variation in summer precipitation over the Tibetan Plateau (TP) at a cloudresolving scale. Compared with the TRMM, precipitation data shows that the model can well simulate the diurnal rainfall cycle with an overall late-afternoon maximum precipitation in the central TP and a nighttime maximum in the southern edge. The simulated diurnal variations in regional circulation and thermodynamics are in good correspondence with the precipitation diurnal cycles in the central and southern edge of TP, respectively. A possible mechanism responsible for the nocturnal precipitation maximum in the southern edge has been proposed, indicating the importance of the TP in regulating the regional circulation and precipitation. (orig.)

  2. Comparative Analysis of Vertebrate Diurnal/Circadian Transcriptomes

    OpenAIRE

    Boyle, Greg; Richter, Kerstin; Priest, Henry D.; Traver, David; Mockler, Todd C.; Chang, Jeffrey T.; Kay, Steve A.; Breton, Ghislain

    2017-01-01

    From photosynthetic bacteria to mammals, the circadian clock evolved to track diurnal rhythms and enable organisms to anticipate daily recurring changes such as temperature and light. It orchestrates a broad spectrum of physiology such as the sleep/wake and eating/fasting cycles. While we have made tremendous advances in our understanding of the molecular details of the circadian clock mechanism and how it is synchronized with the environment, we still have rudimentary knowledge regarding its...

  3. Diurnal variation of radon progeny

    International Nuclear Information System (INIS)

    Seftelis, I.; Nicolaou, G.; Trassanidis, S.; Tsagas, F.N.

    2007-01-01

    The diurnal variation of the gross alpha (α) radioactivity in the air near the ground and the gamma (γ) radioactivity emitted from the ground have been monitored in North-eastern Greece. Meteorological information comprising air temperature and humidity has been simultaneously recorded. Over a period of the 24 h of a typical day, the variation of α-radioactivity reaches a peak in the morning followed by a remarkable decrease, rising to a second peak in the afternoon. Furthermore, its significant dependence on the air temperature and humidity is confirmed, rising with an increase in humidity and decrease in temperature. The variation of the ground γ-radioactivity follows that of the air α-radioactivity. A mathematical model has been developed to describe the diurnal variation of the α-radioactivity in the air near the ground in terms of the above meteorological variables and ground level γ-radioactivity

  4. Diurnal variation of the human adipose transcriptome and the link to metabolic disease

    Directory of Open Access Journals (Sweden)

    Lamb John

    2009-02-01

    Full Text Available Abstract Background Circadian (diurnal rhythm is an integral part of the physiology of the body; specifically, sleep, feeding behavior and metabolism are tightly linked to the light-dark cycle dictated by earth's rotation. Methods The present study examines the effect of diurnal rhythm on gene expression in the subcutaneous adipose tissue of overweight to mildly obese, healthy individuals. In this well-controlled clinical study, adipose biopsies were taken in the morning, afternoon and evening from individuals in three study arms: treatment with the weight loss drug sibutramine/fasted, placebo/fed and placebo/fasted. Results The results indicated that diurnal rhythm was the most significant driver of gene expression variation in the human adipose tissue, with at least 25% of the genes having had significant changes in their expression levels during the course of the day. The mRNA expression levels of core clock genes at a specific time of day were consistent across multiple subjects on different days in all three arms, indicating robust diurnal regulation irrespective of potential confounding factors. The genes essential for energy metabolism and tissue physiology were part of the diurnal signature. We hypothesize that the diurnal transition of the expression of energy metabolism genes reflects the shift in the adipose tissue from an energy-expending state in the morning to an energy-storing state in the evening. Consistent with this hypothesis, the diurnal transition was delayed by fasting and treatment with sibutramine. Finally, an in silico comparison of the diurnal signature with data from the publicly-available Connectivity Map demonstrated a significant association with transcripts that were repressed by mTOR inhibitors, suggesting a possible link between mTOR signaling, diurnal gene expression and metabolic regulation. Conclusion Diurnal rhythm plays an important role in the physiology and regulation of energy metabolism in the adipose

  5. Maize global transcriptomics reveals pervasive leaf diurnal rhythms but rhythms in developing ears are largely limited to the core oscillator.

    Directory of Open Access Journals (Sweden)

    Kevin R Hayes

    Full Text Available BACKGROUND: Plant diurnal rhythms are vital environmental adaptations to coordinate internal physiological responses to alternating day-night cycles. A comprehensive view of diurnal biology has been lacking for maize (Zea mays, a major world crop. METHODOLOGY: A photosynthetic tissue, the leaf, and a non-photosynthetic tissue, the developing ear, were sampled under natural field conditions. Genome-wide transcript profiling was conducted on a high-density 105 K Agilent microarray to investigate diurnal rhythms. CONCLUSIONS: In both leaves and ears, the core oscillators were intact and diurnally cycling. Maize core oscillator genes are found to be largely conserved with their Arabidopsis counterparts. Diurnal gene regulation occurs in leaves, with some 23% of expressed transcripts exhibiting a diurnal cycling pattern. These transcripts can be assigned to over 1700 gene ontology functional terms, underscoring the pervasive impact of diurnal rhythms on plant biology. Considering the peak expression time for each diurnally regulated gene, and its corresponding functional assignment, most gene functions display temporal enrichment in the day, often with distinct patterns, such as dawn or midday preferred, indicating that there is a staged procession of biological events undulating with the diurnal cycle. Notably, many gene functions display a bimodal enrichment flanking the midday photosynthetic maximum, with an initial peak in mid-morning followed by another peak during the afternoon/evening. In contrast to leaves, in developing ears as few as 47 gene transcripts are diurnally regulated, and this set of transcripts includes primarily the core oscillators. In developing ears, which are largely shielded from light, the core oscillator therefore is intact with little outward effect on transcription.

  6. High night temperature strongly impacts TCA cycle, amino acid and polyamine biosynthetic pathways in rice in a sensitivity-dependent manner.

    Science.gov (United States)

    Glaubitz, Ulrike; Erban, Alexander; Kopka, Joachim; Hincha, Dirk K; Zuther, Ellen

    2015-10-01

    Global climate change combined with asymmetric warming can have detrimental effects on the yield of crop plants such as rice (Oryza sativa L.). Little is known about metabolic responses of rice to high night temperature (HNT) conditions. Twelve cultivars with different HNT sensitivity were used to investigate metabolic changes in the vegetative stage under HNT compared to control conditions. Central metabolism, especially TCA cycle and amino acid biosynthesis, were strongly affected particularly in sensitive cultivars. Levels of several metabolites were correlated with HNT sensitivity. Furthermore, pool sizes of some metabolites negatively correlated with HNT sensitivity under control conditions, indicating metabolic pre-adaptation in tolerant cultivars. The polyamines putrescine, spermidine and spermine showed increased abundance in sensitive cultivars under HNT conditions. Correlations between the content of polyamines and 75 other metabolites indicated metabolic shifts from correlations with sugar-phosphates and 1-kestose under control to correlations with sugars and amino and organic acids under HNT conditions. Increased expression levels of ADC2 and ODC1, genes encoding enzymes catalysing the first committed steps of putrescine biosynthesis, were restricted to sensitive cultivars under HNT. Additionally, transcript levels of eight polyamine biosynthesis genes were correlated with HNT sensitivity. Responses to HNT in the vegetative stage result in distinct differences between differently responding cultivars with a dysregulation of central metabolism and an increase of polyamine biosynthesis restricted to sensitive cultivars under HNT conditions and a pre-adaptation of tolerant cultivars already under control conditions with higher levels of potentially protective compatible solutes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. A longitudinal study of diurnal mood variation in depression; characteristics and significance.

    Science.gov (United States)

    Gordijn, M C; Beersma, D G; Bouhuys, A L; Reinink, E; Van den Hoofdakker, R H

    1994-08-01

    The course of 39 depressed in-patients' daily mood was recorded by means of frequent self-ratings during their entire stay (in total 3718 days). The frequency of diurnal variations largely varies between subjects without clear dichotomy in 'diurnal' and 'non-diurnal' subjects and the occurrence of diurnal variations is rather irregular. Mood variability measures rather than average daily mood improvement correlate with the response to sleep deprivation. These observations do not support theories of chronobiological rhythm disturbances in depression. It is argued that depressed subjects largely vary in susceptibility to stimuli. Signals generated by the biological clock or by processes related to the sleep-wake cycle are considered examples of such stimuli.

  8. Diurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity area

    Directory of Open Access Journals (Sweden)

    I. Xueref-Remy

    2018-03-01

    Full Text Available Most of the global fossil fuel CO2 emissions arise from urbanized and industrialized areas. Bottom-up inventories quantify them but with large uncertainties. In 2010–2011, the first atmospheric in situ CO2 measurement network for Paris, the capital of France, began operating with the aim of monitoring the regional atmospheric impact of the emissions coming from this megacity. Five stations sampled air along a northeast–southwest axis that corresponds to the direction of the dominant winds. Two stations are classified as rural (Traînou – TRN; Montgé-en-Goële – MON, two are peri-urban (Gonesse – GON; Gif-sur-Yvette – GIF and one is urban (EIF, located on top of the Eiffel Tower. In this study, we analyze the diurnal, synoptic and seasonal variability of the in situ CO2 measurements over nearly 1 year (8 August 2010–13 July 2011. We compare these datasets with remote CO2 measurements made at Mace Head (MHD on the Atlantic coast of Ireland and support our analysis with atmospheric boundary layer height (ABLH observations made in the center of Paris and with both modeled and observed meteorological fields. The average hourly CO2 diurnal cycles observed at the regional stations are mostly driven by the CO2 biospheric cycle, the ABLH cycle and the proximity to urban CO2 emissions. Differences of several µmol mol−1 (ppm can be observed from one regional site to the other. The more the site is surrounded by urban sources (mostly residential and commercial heating, and traffic, the more the CO2 concentration is elevated, as is the associated variability which reflects the variability of the urban sources. Furthermore, two sites with inlets high above ground level (EIF and TRN show a phase shift of the CO2 diurnal cycle of a few hours compared to lower sites due to a strong coupling with the boundary layer diurnal cycle. As a consequence, the existence of a CO2 vertical gradient above Paris can be inferred, whose amplitude depends

  9. Diurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity area

    Science.gov (United States)

    Xueref-Remy, Irène; Dieudonné, Elsa; Vuillemin, Cyrille; Lopez, Morgan; Lac, Christine; Schmidt, Martina; Delmotte, Marc; Chevallier, Frédéric; Ravetta, François; Perrussel, Olivier; Ciais, Philippe; Bréon, François-Marie; Broquet, Grégoire; Ramonet, Michel; Spain, T. Gerard; Ampe, Christophe

    2018-03-01

    Most of the global fossil fuel CO2 emissions arise from urbanized and industrialized areas. Bottom-up inventories quantify them but with large uncertainties. In 2010-2011, the first atmospheric in situ CO2 measurement network for Paris, the capital of France, began operating with the aim of monitoring the regional atmospheric impact of the emissions coming from this megacity. Five stations sampled air along a northeast-southwest axis that corresponds to the direction of the dominant winds. Two stations are classified as rural (Traînou - TRN; Montgé-en-Goële - MON), two are peri-urban (Gonesse - GON; Gif-sur-Yvette - GIF) and one is urban (EIF, located on top of the Eiffel Tower). In this study, we analyze the diurnal, synoptic and seasonal variability of the in situ CO2 measurements over nearly 1 year (8 August 2010-13 July 2011). We compare these datasets with remote CO2 measurements made at Mace Head (MHD) on the Atlantic coast of Ireland and support our analysis with atmospheric boundary layer height (ABLH) observations made in the center of Paris and with both modeled and observed meteorological fields. The average hourly CO2 diurnal cycles observed at the regional stations are mostly driven by the CO2 biospheric cycle, the ABLH cycle and the proximity to urban CO2 emissions. Differences of several µmol mol-1 (ppm) can be observed from one regional site to the other. The more the site is surrounded by urban sources (mostly residential and commercial heating, and traffic), the more the CO2 concentration is elevated, as is the associated variability which reflects the variability of the urban sources. Furthermore, two sites with inlets high above ground level (EIF and TRN) show a phase shift of the CO2 diurnal cycle of a few hours compared to lower sites due to a strong coupling with the boundary layer diurnal cycle. As a consequence, the existence of a CO2 vertical gradient above Paris can be inferred, whose amplitude depends on the time of the day and on

  10. Effects of Melatonin on Diurnal Mood.

    Science.gov (United States)

    1996-03-01

    As a substance produced nocturnally by the pineal gland, melatonin may have utility in promoting sleep during diurnal or other unusual sleep periods . Oral...substance produced nocturnally by the pineal gland, melatonin may have utility in promoting sleep during diurnal or other unusual sleep periods . Oral

  11. An unusual kind of diurnal streamflow variation

    Directory of Open Access Journals (Sweden)

    Cuevas Jaime G.

    2018-03-01

    Full Text Available During hydrological research in a Chilean swamp forest, we noted a pattern of higher streamflows close to midday and lower ones close to midnight, the opposite of an evapotranspiration (Et-driven cycle. We analyzed this diurnal streamflow signal (DSS, which appeared mid-spring (in the growing season. The end of this DSS coincided with a sustained rain event in autumn, which deeply affected stream and meteorological variables. A survey along the stream revealed that the DSS maximum and minimum values appeared 6 and 4 hours earlier, respectively, at headwaters located in the mountain forests/ plantations than at the control point in the swamp forest. Et in the swamp forest was higher in the morning and in the late afternoon, but this process could not influence the groundwater stage. Trees in the mountain headwaters reached their maximum Ets in the early morning and/or close to midday. Our results suggest that the DSS is a wave that moves from forests high in the mountains towards lowland areas, where Et is decoupled from the DSS. This signal delay seems to convert the link between streamflow and Et in an apparent, but spurious positive relationship. It also highlights the role of landscape heterogeneity in shaping hydrological processes.

  12. Familial circadian rhythm disorder in the diurnal primate, Macaca mulatta.

    Directory of Open Access Journals (Sweden)

    Irina V Zhdanova

    Full Text Available In view of the inverse temporal relationship of central clock activity to physiological or behavioral outputs in diurnal and nocturnal species, understanding the mechanisms and physiological consequences of circadian disorders in humans would benefit from studies in a diurnal animal model, phylogenetically close to humans. Here we report the discovery of the first intrinsic circadian disorder in a family of diurnal non-human primates, the rhesus monkey. The disorder is characterized by a combination of delayed sleep phase, relative to light-dark cycle, mutual desynchrony of intrinsic rhythms of activity, food intake and cognitive performance, enhanced nighttime feeding or, in the extreme case, intrinsic asynchrony. The phenotype is associated with normal length of intrinsic circadian period and requires an intact central clock, as demonstrated by an SCN lesion. Entrainment to different photoperiods or melatonin administration does not eliminate internal desynchrony, though melatonin can temporarily reinstate intrinsic activity rhythms in the animal with intrinsic asynchrony. Entrainment to restricted feeding is highly effective in animals with intrinsic or SCN lesion-induced asynchrony. The large isolated family of rhesus macaques harboring the disorder provides a powerful new tool for translational research of regulatory circuits underlying circadian disorders and their effective treatment.

  13. Diurnal regulation of scent emission in rose flowers.

    Science.gov (United States)

    Hendel-Rahmanim, Keren; Masci, Tania; Vainstein, Alexander; Weiss, David

    2007-11-01

    Previous studies have shown diurnal oscillation of scent emission in rose flowers with a peak during the day (Helsper in Planta 207:88-95, 1998; Picone in Planta 219:468-478, 2004). Here, we studied the regulation of scent production and emission in Rosa hybrida cv. Fragrant Cloud during the daily cycle and focused on two terpenoid compounds, germacrene D and geranyl acetate, whose biosynthetic genes have been characterized by us previously. The emission of geranyl acetate oscillated during the daily light/dark cycle with a peak early in the light period. A similar daily fluctuation was found in the endogenous level of this compound and in the expression of its biosynthetic gene, alcohol acetyl transferase (RhAAT). The rhythmic expression of RhAAT continued under conditions of constant light or darkness, indicating regulation by the endogenous circadian clock. However, the accumulation and emission of geranyl acetate ceased under continuous light. Our results suggest that geranyl acetate production is limited by the level of its substrate geraniol, which is suppressed under constant light conditions. The emission of germacrene D also oscillated during the daily cycle with a peak early in the light period. However, the endogenous level of this compound and the expression of its biosynthetic gene germacrene D synthase (RhGDS) were constant throughout the day. The diurnal oscillation of germacrene D emission ceased under continuous light, suggesting direct regulation by light. Our results demonstrate the complexity of the diurnal regulation of scent emission: although the daily emission of most scent compounds is synchronized, various independently evolved mechanisms control the production, accumulation and release of different volatiles.

  14. Diurnal expression of proteins in the retina of the blind cone-rod homeobox (Crx−/−) mouse and the 129/Sv mouse

    DEFF Research Database (Denmark)

    Møller, Morten; Rath, Martin Fredensborg; Ludvigsen, Maja

    2017-01-01

    rhythms were specifically identified as enzymes involved in glucose metabolism, Krebs cycle, and mitochondrial enzymes. Data are available via ProteomeXchange with identifier PXD005556.  Conclusion: We show diurnal protein rhythms in the retina of a mouse lacking the rods and cones. The diurnal protein...

  15. Outcome of Treatment of Human HeLa Cervical Cancer Cells With Roscovitine Strongly Depends on the Dosage and Cell Cycle Status Prior to the Treatment

    Czech Academy of Sciences Publication Activity Database

    Wesierska-Gadek, J.; Borza, A.; Walzi, E.; Kryštof, Vladimír; Maurer, M.; Komina, O.; Wandl, S.

    2009-01-01

    Roč. 106, č. 5 (2009), s. 937-955 ISSN 0730-2312 Institutional research plan: CEZ:AV0Z50380511 Keywords : APOPTOSIS * CELL CYCLE ARREST * CYCLIN-DEPENDENT KINASES Subject RIV: ED - Physiology Impact factor: 2.935, year: 2009

  16. Seasonal and diurnal variation of outdoor radon (222Rn) concentrations in urban and rural area with reference to meteorological conditions

    International Nuclear Information System (INIS)

    Podstawczynska, A.; Pawlak, W.; Kozak, K.; Mazur, J.

    2010-01-01

    The objective of the study was to investigate temporal variability of outdoor radon ( 222 Rn) concentration registered in the center of Lodz (urban station), at Ciosny (rural station) and Krakow (suburban station) in relation to meteorological parameters (i.e. air temperature, temperature vertical gradient, wind speed, soil heat flux, volumetric water content in soil) with special consideration of urban-rural differences. Continuous measurements of 222 Rn concentration (at 60 min intervals) were performed at a height of 2 m above the ground using AlphaGUARD PQ2000PRO (ionization chamber) from January 2008 to May 2009. 222 Rn levels were characterized by a diurnal cycle with an early morning maximum and a minimum in the afternoon. The well-marked 24 h pattern of radon concentration occurred in summer at anticyclonic weather with cloudless sky, light wind and large diurnal temperature ranges. The urban measurement site was characterized by the lowest atmospheric 222 Rn concentration and an urban-rural differences of radon levels increased from winter to summer and during the nighttime periods. The maximum contrasts of 222 Rn levels between Lodz and Ciosny, reaching - 30 Bq m -3 , were registered in June and July during the urban heat island (UHI) phenomenon (a positive thermal anomaly of a city if compared to rural area) and strong thermal inversion near the ground in the rural area. (authors)

  17. TIMP3 is a CLOCK-dependent diurnal gene that inhibits the expression of UVB-induced inflammatory cytokines in human keratinocytes.

    Science.gov (United States)

    Park, Sunyoung; Kim, Kyuhan; Bae, Il-Hong; Lee, Sung Hoon; Jung, Jiyong; Lee, Tae Ryong; Cho, Eun-Gyung

    2018-03-01

    As the outermost physical barrier of an organism, the skin is diurnally exposed to UV radiation (UVR). Recent studies have revealed that the skin exhibits a circadian rhythm in various functions, and this oscillation is disturbed and reset via a strong environmental cue, the UVR. However, a molecular link between circadian perturbation by UVR and UVR-induced cellular responses has not been investigated. We identified tissue inhibitor of metalloproteinase ( TIMP)- 3 as a novel circadian locomotor output cycles kaput (CLOCK)-dependent diurnal gene by using a CLOCK-knockdown strategy in human keratinocytes. Among dozens of identified transcripts down-regulated by CLOCK knockdown, TIMP3 displayed a rhythmic expression in a CLOCK-dependent manner, in which the expression of matrix metalloproteinase (MMP)-1 and inflammatory cytokines, such as TNF-α, chemokine (C-X-C motif) ligand (CXCL)-1, and IL-8, were inversely regulated. Upon UVB exposure, the expression of CLOCK and TIMP3 was down-regulated, which led to an up-regulation of secretion of MMP1 and TNF-α proteins and in the transcription of CXCL1 and IL-8 via CCAAT-enhancer binding protein (C/EBP)-α. UVB-induced TNF-α secretion increased further or decreased by knockdown or overexpression of TIMP3, respectively, as well as by CLOCK. As a novel CLOCK-dependent diurnal gene, TIMP3 inhibits the expression of inflammatory cytokines that are up-regulated by UV irradiation in human keratinocytes. Thus, our work suggests a molecular link between circadian perturbation by UVR and UVR-induced inflammation.-Park, S., Kim, K., Bae, I.-H., Lee, S. H., Jung, J., Lee, T. R., Cho, E.-G. TIMP3 is a CLOCK-dependent diurnal gene that inhibits the expression of UVB-induced inflammatory cytokines in human keratinocytes.

  18. Does a weekend effect in diurnal temperature range exist in the eastern and central Tibetan Plateau?

    International Nuclear Information System (INIS)

    You Qinglong; Kang Shichang; Xu Yanwei; Huang Jie; Fluegel, Wolfgang-Albert; Sanchez-Lorenzo, Arturo; Yan Yuping

    2009-01-01

    The 'weekend effect' method (defined here as the average for Saturday through Monday minus the average for Wednesday through Friday) has been used to identify fingerprints of anthropogenic emissions. Based on daily maximum and minimum temperature series from the China Meteorological Administration homogenized dataset, the weekend effect in diurnal temperature range (DTR) at 71 stations with elevations above 2000 m asl in the eastern and central Tibetan Plateau (TP) during 1961-2004 is examined, and principal component analysis (PCA) is performed to cluster series into four subregions with similar weekend effect variability. The DTR demonstrates a much stronger negative weekend effect in autumn and shows larger positive values in winter, which provides a strong evidence of anthropogenic activity in this region, especially in the central TP. Analysis by topographic type and degree of urbanization shows a clear weekly cycle which cannot be explained by a microclimate effect. We hypothesize that the interaction with anthropogenic aerosols from local emissions and transported by atmospheric circulation may account for the weekly cycle in the TP. More caution should be paid to the driving mechanism of the weekend effect in the most remote and clear regions in the world.

  19. diurnal and seasonal water relations of the desert phreatophyte prosopis-glandulosa (honey mesquite) in the Sonoran Desert of California

    OpenAIRE

    Nilsen, E. T.; Sharifi, M. R.; Rundel, P. W.; Jarrell, W. M.; Virginia, R. A.

    1983-01-01

    Diurnal and Seasonal water relations were monitored in a population of Prosopis glandulosa var. torreyana in the Sonoran Desert of southern California. Prosopis glandulosa at this research site acquired its water from a ground water source 4-6 m deep. Measurements of diurnal and seasonal cycles of aboveground environmental conditions, soil moisture, and soil water potential (to 6 m depth) were taken to ascertain environmental water availability and water stress. Leaf water potential, leaf con...

  20. Diurnal rainfall variability over the Upper Blue Nile Basin: a remote sensing based approach

    NARCIS (Netherlands)

    Rientjes, T.H.M.; Haile, A.T.; Fenta, A.A.

    2013-01-01

    In this study we aim to assess the diurnal cycle of rainfall across the Upper Blue Nile (UBN) basin using satellite observations from Tropical Rainfall Measuring Mission (TRMM). Seven years (2002-2008) of Precipitation Radar (PR) and TRMM Microwave Imager (TMI) data are used and analyses are based

  1. Diurnal effects of anoxia on the metabolome of the seagrass Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Fragner, Lena; Holmer, Marianne

    2015-01-01

    We investigated the response, adaptation and tolerance mechanisms of the temperate seagrass Zostera marina to water column anoxia. We exposed Z. marina to a diurnal light/dark cycle under anoxia and assessed the metabolic response by measuring the metabolome with gas chromatography coupled to mass...

  2. ESA STSE “SST Diurnal Variability: Regional Extend - Implications in Atmospheric Modelling”

    DEFF Research Database (Denmark)

    Karagali, Ioanna

    The diurnal variability of SST, driven by the coincident occurrence of low enough wind and solar heating, has been observed in various regions of the global ocean [4, 5, 6]. Atmospheric, oceanic and climate models are not adequately resolving the daily SST cycle, resulting in biases of the total...

  3. Strong Gradients in Forest Sensitivity to Climate Change Revealed by Dynamics of Forest Fire Cycles in the Post Little Ice Age Era

    Science.gov (United States)

    Drobyshev, Igor; Bergeron, Yves; Girardin, Martin P.; Gauthier, Sylvie; Ols, Clémentine; Ojal, John

    2017-10-01

    The length of the fire cycle is a critical factor affecting the vegetation cover in boreal and temperate regions. However, its responses to climate change remain poorly understood. We reanalyzed data from earlier studies of forest age structures at the landscape level, in order to map the evolution of regional fire cycles across Eastern North American boreal and temperate forests, following the termination of the Little Ice Age (LIA). We demonstrated a well-defined spatial pattern of post-LIA changes in the length of fire cycles toward lower fire activity during the 1800s and 1900s. The western section of Eastern North America (west of 77°W) experienced a decline in fire activity as early as the first half of the 1800s. By contrast, the eastern section showed these declines as late as the early 1900s. During a regionally fire-prone period of the 1910s-1920s, forests in the western section of Eastern boreal North America burned more than forests in the eastern section. The climate appeared to dominate over vegetation composition and human impacts in shaping the geographical pattern of the post-LIA change in fire activity. Changes in the atmospheric circulation patterns following the termination of the LIA, specifically changes in Arctic Oscillation and the strengthening of the Continental Polar Trough, were likely drivers of the regional fire dynamics.

  4. Variability of Diurnal Temperature Range During Winter Over Western Himalaya: Range- and Altitude-Wise Study

    Science.gov (United States)

    Shekhar, M. S.; Devi, Usha; Dash, S. K.; Singh, G. P.; Singh, Amreek

    2018-04-01

    The current trends in diurnal temperature range, maximum temperature, minimum temperature, mean temperature, and sun shine hours over different ranges and altitudes of Western Himalaya during winter have been studied. Analysis of 25 years of data shows an increasing trend in diurnal temperature range over all the ranges and altitudes of Western Himalaya during winter, thereby confirming regional warming of the region due to present climate change and global warming. Statistical studies show significant increasing trend in maximum temperature over all the ranges and altitudes of Western Himalaya. Minimum temperature shows significant decreasing trend over Pir Panjal and Shamshawari range and significant increasing trend over higher altitude of Western Himalaya. Similarly, sunshine hours show significant decreasing trend over Karakoram range. There exists strong positive correlation between diurnal temperature range and maximum temperature for all the ranges and altitudes of Western Himalaya. Strong negative correlation exists between diurnal temperature range and minimum temperature over Shamshawari and Great Himalaya range and lower altitude of Western Himalaya. Sunshine hours show strong positive correlation with diurnal temperature range over Pir Panjal and Great Himalaya range and lower and higher altitudes.

  5. Diurnal variation of zooplankton off Versova (Bombay)

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Desai, B.N.

    Physicochemical parameters and diurnal variaion of zooplankton were studied off Versova on 17/18 February 1981. Salinity and dissolved oxygen showed limited variation during the period of study. Nutrient values followed the tidal rhythm and high...

  6. Scale interactions on diurnal toseasonal timescales and their relevanceto model systematic errors

    Directory of Open Access Journals (Sweden)

    G. Yang

    2003-06-01

    Full Text Available Examples of current research into systematic errors in climate models are used to demonstrate the importance of scale interactions on diurnal,intraseasonal and seasonal timescales for the mean and variability of the tropical climate system. It has enabled some conclusions to be drawn about possible processes that may need to be represented, and some recommendations to be made regarding model improvements. It has been shown that the Maritime Continent heat source is a major driver of the global circulation but yet is poorly represented in GCMs. A new climatology of the diurnal cycle has been used to provide compelling evidence of important land-sea breeze and gravity wave effects, which may play a crucial role in the heat and moisture budget of this key region for the tropical and global circulation. The role of the diurnal cycle has also been emphasized for intraseasonal variability associated with the Madden Julian Oscillation (MJO. It is suggested that the diurnal cycle in Sea Surface Temperature (SST during the suppressed phase of the MJO leads to a triggering of cumulus congestus clouds, which serve to moisten the free troposphere and hence precondition the atmosphere for the next active phase. It has been further shown that coupling between the ocean and atmosphere on intraseasonal timescales leads to a more realistic simulation of the MJO. These results stress the need for models to be able to simulate firstly, the observed tri-modal distribution of convection, and secondly, the coupling between the ocean and atmosphere on diurnal to intraseasonal timescales. It is argued, however, that the current representation of the ocean mixed layer in coupled models is not adequate to represent the complex structure of the observed mixed layer, in particular the formation of salinity barrier layers which can potentially provide much stronger local coupling between the atmosphere and ocean on diurnal to intraseasonal timescales.

  7. Diurnal Variation of Intravenous Thrombolysis Rates for Acute Ischemic Stroke and Associated Quality Performance Parameters

    Directory of Open Access Journals (Sweden)

    Björn Reuter

    2017-07-01

    Full Text Available IntroductionBased on data from the Baden-Wuerttemberg stroke registry, we aimed to explore the diurnal variation of acute ischemic stroke (IS care delivery.Materials and methods92,530 IS patients were included, of whom 37,471 (40% presented within an onset-to-door time ≤4.5 h. Daytime was stratified in 3-h time intervals and working vs. non-working hours. Stroke onset and hospital admission time, rate of door-to-neurological examination time ≤30 min, onset-/door-to-imaging time IV thrombolysis (IVT rates, and onset-/door-to-needle time were determined. Multivariable regression models were used stratified by stroke onset and hospital admission time to assess the relationship between IVT rates, quality performance parameters, and daytime. The time interval 0:00 h to 3:00 h and working hours, respectively, were taken as reference.ResultsThe IVT rate of the whole study population was strongly associated with the sleep–wake cycle. In patients presenting within the 4.5-h time window and potentially eligible for IVT stratification by hospital admission time identified two time intervals with lower IVT rates. First, between 3:01 h and 6:00 h (IVT rate 18% and likely attributed to in-hospital delays with the lowest diurnal rate of door-to-neurological examination time ≤30 min and the longest door-to-needle time Second, between 6:01 h and 15:00 h (IVT rate 23–25% compared to the late afternoon and evening hours (IVT rate 27–29% due to a longer onset-to-imaging time and door-to-imaging time. No evidence for a compromised stroke service during non-working hours was observed.ConclusionThe analysis provides evidence that acute IS care is subject to diurnal variation which may affect stroke outcome. An optimization of IS care aiming at constantly high IVT rates over the course of the day therefore appears desirable.

  8. Climatology of diurnal tide and its long-term variability in the lower middle atmosphere over a tropical station

    Science.gov (United States)

    Kumar, P. Vinay; Dutta, Gopa; Mohammad, Salauddin; Rao, B. Venkateswara

    2017-10-01

    ECMWF reanalysis (ERA-interim) data of winds for two solar cycles (1991-2012) are harmonically analyzed to delineate the characteristics and variability of diurnal tide over a tropical site (13.5° N, 79.5° E). The diurnal cycle horizontal winds measured by Gadanki (13.5° N, 79.2° E) mesosphere-stratosphere-troposphere (MST) radar between May 2005 and April 2006 have been used to compute 24 h tidal amplitudes and phases and compared with the corresponding results obtained from ERA winds. The climatological diurnal tidal amplitudes and phases have been estimated from surface to ˜33 km using ERA interim data. The amplitudes and phases obtained in the present study are found to compare reasonably well with Global Scale Wave Model (GSWM-09). Diurnal tides show larger amplitudes in the lower troposphere below 5 km during summer and in the mid-stratosphere mainly during equinoctial months and early winter. Water vapor and convection in the lower troposphere are observed to play major roles in exciting 24-h tide. Correlations between diurnal amplitude and integrated water vapor and between diurnal amplitude and outgoing longwave radiation (OLR) are 0.59 and -0.34, respectively. Ozone mixing ratio correlates ( ρ = 0.66) well with diurnal amplitude and shows annual variation in the troposphere whereas semi-annual variation is observed at stratospheric heights with stronger peaks in equinoctial months. A clear annual variation of diurnal amplitude is displayed in the troposphere and interannual variability becomes prominent in the stratosphere which could be partly due to the influence of equatorial stratospheric QBO. The influence of solar activity on diurnal oscillations is found to be insignificant.

  9. Diurnal Variation In Behaviour Of Pink-Footed Geese (Anser Brachyrhynchus) During Spring Migration In Trøndelag, Norway

    DEFF Research Database (Denmark)

    Chudzińska, Magda Ewa; Madsen, Jesper; Nabe-Nielsen, Jacob

    habitat type, we fitted a model containing all predictors we believe may influence geese behaviour. The number of feeding and alert geese on fields displayed a strong diurnal trend, which varied among habitat types, frequent and sporadic disturbance, but not flock size. On roost sites, geese also showed...... diurnal variation in resting and alertness. The observed diurnal variation differed from what has been found on the wintering grounds indicating that during spring, birds increase their foraging intensity in order to meet energetic and nutritional demands in a short time. Seasonal availability of habitats...

  10. Inter-daily variability of a strong thermally-driven wind system over the Atacama Desert of South America: synoptic forcing and short-term predictability using the GFS global model

    Science.gov (United States)

    Jacques-Coper, Martín; Falvey, Mark; Muñoz, Ricardo C.

    2015-07-01

    Crucial aspects of a strong thermally-driven wind system in the Atacama Desert in northern Chile during the extended austral winter season (May-September) are studied using 2 years of measurement data from the Sierra Gorda 80-m meteorological mast (SGO, 22° 56' 24″ S; 69° 7' 58″ W, 2,069 m above sea level (a.s.l.)). Daily cycles of atmospheric variables reveal a diurnal (nocturnal) regime, with northwesterly (easterly) flow and maximum mean wind speed of 8 m/s (13 m/s) on average. These distinct regimes are caused by pronounced topographic conditions and the diurnal cycle of the local radiative balance. Wind speed extreme events of each regime are negatively correlated at the inter-daily time scale: High diurnal wind speed values are usually observed together with low nocturnal wind speed values and vice versa. The associated synoptic conditions indicate that upper-level troughs at the coastline of southwestern South America reinforce the diurnal northwesterly wind, whereas mean undisturbed upper-level conditions favor the development of the nocturnal easterly flow. We analyze the skill of the numerical weather model Global Forecast System (GFS) in predicting wind speed at SGO. Although forecasted wind speeds at 800 hPa do show the diurnal and nocturnal phases, observations at 80 m are strongly underestimated by the model. This causes a pronounced daily cycle of root-mean-squared error (RMSE) and bias in the forecasts. After applying a simple Model Output Statistics (MOS) post-processing, we achieve a good representation of the wind speed intra-daily and inter-daily variability, a first step toward reducing the uncertainties related to potential wind energy projects in the region.

  11. On the Trend of the Annual Mean, Maximum, and Minimum Temperature and the Diurnal Temperature Range in the Armagh Observatory, Northern Ireland, Dataset, 1844 -2012

    Science.gov (United States)

    Wilson, Robert M.

    2013-01-01

    Examined are the annual averages, 10-year moving averages, decadal averages, and sunspot cycle (SC) length averages of the mean, maximum, and minimum surface air temperatures and the diurnal temperature range (DTR) for the Armagh Observatory, Northern Ireland, during the interval 1844-2012. Strong upward trends are apparent in the Armagh surface-air temperatures (ASAT), while a strong downward trend is apparent in the DTR, especially when the ASAT data are averaged by decade or over individual SC lengths. The long-term decrease in the decadaland SC-averaged annual DTR occurs because the annual minimum temperatures have risen more quickly than the annual maximum temperatures. Estimates are given for the Armagh annual mean, maximum, and minimum temperatures and the DTR for the current decade (2010-2019) and SC24.

  12. Diurnal Reflectance Changes in Vegetation Observed with AVIRIS

    Science.gov (United States)

    Vanderbilt, V. C.; Ambrosia, V. G.; Ustin, S. L.

    1998-01-01

    Among the most important short-term dynamic biological processes are diurnal changes in canopy water relations. Plant regulation of water transport through stomatal openings affects other gaseous transport processes, often dramatically decreasing photosynthetic fixation of carbon dioxide during periods of water stress. Water stress reduces stomatal conductance of water vapor through the leaf surface and alters the diurnal timing of stomatal opening. Under non-water stressed conditions, stomates typically open soon after dawn and transpire water vapor throughout the daylight period. During stress periods, stomates may close for part of the day, generally near mid-day. Under prolonged stress conditions, stomatal closure shifts to earlier times during the day; stomates may close by mid-morning and remain closed until the following morning - or remain closed entirely. Under these conditions the relationship between canopy greenness (e.g., measured with a vegetation index or by spectral mixture analysis) and photosynthetic fixation of carbon is lost and the remotely sensed vegetation metric is a poor predictor of gas exchange. Prediction of stomatal regulation and exchange of water and trace gases is critical for ecosystem and climate models to correctly estimate budgets of these gases and understand or predict other processes like gross and net ecosystem primary production. Plant gas exchange has been extensively studied by physiologists at the leaf and whole plant level and by biometeorologists at somewhat larger scales. While these energy driven processes follow a predictable if somewhat asymmetric diurnal cycle dependent on soil water availability and the constraints imposed by the solar energy budget, they are nonetheless difficult to measure at the tree and stand levels using conventional methods. Ecologists have long been interested in the potential of remote sensing for monitoring physiological changes using multi-temporal images. Much of this research has

  13. Regimes of Diurnal Variation of Summer Rainfall over Subtropical East Asia

    Energy Technology Data Exchange (ETDEWEB)

    Yuan W.; Lin W.; Yu, R.; Zhang, M.; Chen, H.; Li, J.

    2012-05-01

    Using hourly rain gauge records and Tropical Rainfall Measuring Mission 3B42 from 1998 to 2006, the authors present an analysis of the diurnal characteristics of summer rainfall over subtropical East Asia. The study shows that there are four different regimes of distinct diurnal variation of rainfall in both the rain gauge and the satellite data. They are located over the Tibetan Plateau with late-afternoon and midnight peaks, in the western China plain with midnight to early-morning peaks, in the eastern China plain with double peaks in late afternoon and early morning, and over the East China Sea with an early-morning peak. No propagation of diurnal phases is found from the land to the ocean across the coastlines. The different diurnal regimes are highly correlated with the inhomogeneous underlying surface, such as the plateau, plain, and ocean, with physical mechanisms consistent with the large-scale 'mountain-valley' and 'land-sea' breezes and convective instability. These diurnal characteristics over subtropical East Asia can be used as diagnostic metrics to evaluate the physical parameterization and hydrological cycle of climate models over East Asia.

  14. Melatonin-induced CBF/DREB1s are essential for diurnal change of disease resistance and CCA1 expression in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Wei, Yunxie; He, Chaozu

    2016-03-01

    Melatonin (N-acetyl-5-methoxytryptamine) is an important regulator of circadian rhythms and immunity in animals. However, the diurnal changes of endogenous melatonin and melatonin-mediated diurnal change of downstream responses remain unclear in Arabidopsis. Using the publicly available microarray data, we found that the transcript levels of two melatonin synthesis genes (serotonin N-acetyltransferase (SNAT) and caffeate O-methyltransferase (COMT)) and endogenous melatonin level were regulated by diurnal cycles, with different magnitudes of change. Moreover, the transcripts of C-repeat-binding factors (CBFs)/Drought response element Binding 1 factors (DREB1s) were co-regulated by exogenous melatonin and diurnal changes, indicating the possible correlation among clock, endogenous melatonin level and AtCBFs expressions. Interestingly, diurnal change of plant immunity against Pst DC3000 and CIRCADIANCLOCK ASSOCIATED 1 (CCA1) expression were largely lost in AtCBFs knockdown line-amiR-1. Taken together, this study identifies the molecular pathway underlying the diurnal changes of immunity in Arabidopsis. Notably, the diurnal changes of endogenous melatonin may regulate corresponding changes of AtCBF/DREB1s expression and their underlying diurnal cycle of plant immunity and AtCCA1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Correlation between the water drinking test and modified diurnal tension curve in untreated glaucomatous eyes

    Directory of Open Access Journals (Sweden)

    Carlos Gustavo Vasconcelos-Moraes

    2008-01-01

    Full Text Available OBJECTIVES: To investigate the correlation and agreement between the intraocular pressure peaks detected during the water drinking test and the modified diurnal tension curve in untreated glaucomatous eyes. INTRODUCTION: It has been suggested that the intraocular pressure peaks detected during the water drinking test predict the peaks observed during a 24-hour diurnal tension curve. A more feasible and practical test for assessing intraocular pressure peaks in glaucomatous eyes during office hours would be of great clinical utility. METHODS: This was a prospective study involving open angle glaucoma patients without anti-glaucoma medication submitted to the modified diurnal tension curve and water drinking test on the same day. The intraocular pressure peaks during the water drinking test and the modified diurnal tension curve were reported and compared. Statistical analysis was performed to assess the correlation and agreement between intraocular pressure peak measurements. RESULTS: The correlation between intraocular pressure peaks during the water drinking test and modified diurnal tension curve was significant and strong (Pearson's Correlation Coefficient r=0.780, p<0.0001. Limited agreement was observed between these measurements. Eighty-two percent of intraocular pressure peaks were higher during the water drinking test than the modified diurnal tension curve. DISCUSSION: These findings suggest that the water drinking test may be used as tool to assess risk factors for glaucomatous patients. CONCLUSION: Intraocular pressure peaks detected during the water drinking test could be used in clinical practice to both estimate the peaks observed during the modified diurnal tension curve and assess the status of the eye's outflow facility.

  16. Extensive Regulation of Diurnal Transcription and Metabolism by Glucocorticoids.

    Directory of Open Access Journals (Sweden)

    Benjamin D Weger

    2016-12-01

    Full Text Available Altered daily patterns of hormone action are suspected to contribute to metabolic disease. It is poorly understood how the adrenal glucocorticoid hormones contribute to the coordination of daily global patterns of transcription and metabolism. Here, we examined diurnal metabolite and transcriptome patterns in a zebrafish glucocorticoid deficiency model by RNA-Seq, NMR spectroscopy and liquid chromatography-based methods. We observed dysregulation of metabolic pathways including glutaminolysis, the citrate and urea cycles and glyoxylate detoxification. Constant, non-rhythmic glucocorticoid treatment rescued many of these changes, with some notable exceptions among the amino acid related pathways. Surprisingly, the non-rhythmic glucocorticoid treatment rescued almost half of the entire dysregulated diurnal transcriptome patterns. A combination of E-box and glucocorticoid response elements is enriched in the rescued genes. This simple enhancer element combination is sufficient to drive rhythmic circadian reporter gene expression under non-rhythmic glucocorticoid exposure, revealing a permissive function for the hormones in glucocorticoid-dependent circadian transcription. Our work highlights metabolic pathways potentially contributing to morbidity in patients with glucocorticoid deficiency, even under glucocorticoid replacement therapy. Moreover, we provide mechanistic insight into the interaction between the circadian clock and glucocorticoids in the transcriptional regulation of metabolism.

  17. Extensive Regulation of Diurnal Transcription and Metabolism by Glucocorticoids.

    Science.gov (United States)

    Weger, Benjamin D; Weger, Meltem; Görling, Benjamin; Schink, Andrea; Gobet, Cédric; Keime, Céline; Poschet, Gernot; Jost, Bernard; Krone, Nils; Hell, Rüdiger; Gachon, Frédéric; Luy, Burkhard; Dickmeis, Thomas

    2016-12-01

    Altered daily patterns of hormone action are suspected to contribute to metabolic disease. It is poorly understood how the adrenal glucocorticoid hormones contribute to the coordination of daily global patterns of transcription and metabolism. Here, we examined diurnal metabolite and transcriptome patterns in a zebrafish glucocorticoid deficiency model by RNA-Seq, NMR spectroscopy and liquid chromatography-based methods. We observed dysregulation of metabolic pathways including glutaminolysis, the citrate and urea cycles and glyoxylate detoxification. Constant, non-rhythmic glucocorticoid treatment rescued many of these changes, with some notable exceptions among the amino acid related pathways. Surprisingly, the non-rhythmic glucocorticoid treatment rescued almost half of the entire dysregulated diurnal transcriptome patterns. A combination of E-box and glucocorticoid response elements is enriched in the rescued genes. This simple enhancer element combination is sufficient to drive rhythmic circadian reporter gene expression under non-rhythmic glucocorticoid exposure, revealing a permissive function for the hormones in glucocorticoid-dependent circadian transcription. Our work highlights metabolic pathways potentially contributing to morbidity in patients with glucocorticoid deficiency, even under glucocorticoid replacement therapy. Moreover, we provide mechanistic insight into the interaction between the circadian clock and glucocorticoids in the transcriptional regulation of metabolism.

  18. The effects of the diurnal atmospheric variability on entry, descent and landing on Mars

    Directory of Open Access Journals (Sweden)

    Marčeta D.

    2014-01-01

    Full Text Available Landing on Mars is extremely challenging task due to the fact that the Martian atmosphere is the most hostile environment in the Solar system to perform the entry, descent and landing (EDL process, because it is thick enough to create substantial heating of the entry vehicle but not thick enough to reduce its velocity to the one necessary for safe landing. Beside this, the atmosphere is very dynamic mainly due to high eccentricity of the Martian orbit, obliquity of the orbital to the equatorial plane and close alignment of the winter solstice and the orbital perihelion. Although seasonal variations of atmospheric parameters are significantly larger than the diurnal, it is very important to analyze diurnal cycles as they can significantly change vertical and horizontal atmospheric profiles in very short time intervals. This can present a serious threat to missions which have very precise timings and specific requirements such as the requirement for the daytime landing to enable ground images acquisition during the descent and landing phase. A 3-degrees-of-freedom trajectory integration routine was combined with the Mars Global Reference Atmospheric Model (Mars-GRAM to identify the dependence of the EDL profiles on the diurnal cycles of atmospheric parameters throughout the Martian year. The obtained results show that the influence of the diurnal cycles is the largest at the equator and decreases relatively symmetrically towards the poles with a slightly stronger influence in the northern hemisphere. Also, there is a significant influence of the orbital position of Mars on the effect of diurnal atmospheric variations which causes that, around the orbital perihelion and winter solstice, there is some kind of inversion of the dependance of optimal entry timing on latitude of the landing site comparing to the rest of the Martian year. [Projekat Ministarstva nauke Republike Srbije, br. 176002

  19. Phylogenetic relationships of diurnal, phytotelm-breeding Melanophryniscus (Anura: Bufonidae) based on mitogenomic data.

    Science.gov (United States)

    Pie, Marcio R; Ströher, Patrícia R; Belmonte-Lopes, Ricardo; Bornschein, Marcos R; Ribeiro, Luiz F; Faircloth, Brant C; McCormack, John E

    2017-09-10

    Melanophryniscus is a bufonid frog genus with a broad geographic distribution over southeastern South America. In recent years, several new species of Melanophryniscus have been discovered in southern Brazil showing a distinctive life-history strategy for the genus - breeding in phytotelmata - as well as a strong association with high-altitude regions. In this study, we use mitogenomic data to infer the phylogenetic relationships among diurnal, phytotelm-breeding Melanophryniscus and to determine the timing of their divergence. We obtained the mitochondrial genomes (not including the control region) for eight individuals of Melanophryniscus representing all three described species (M. alipioi, M. milanoi, and M. xanthostomus), as well as some recently-discovered and potentially new species. Gene order was conserved in all species and corresponded to the general order found in bufonids. Although the phylogenetic relationships among the studied species was poorly supported, dating confirmed that they diverged during the Pleistocene, suggesting that phytotelm breeding could have arisen during drier periods in the glacial/interglacial cycles due to a decrease in the availability of permanent streams or ephemeral/temporary streams or ponds in which Melanophryniscus species commonly breed. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Diurnal variations of dissolved and colloidal organic carbon and trace metals in a boreal lake during summer bloom.

    Science.gov (United States)

    Pokrovsky, O S; Shirokova, L S

    2013-02-01

    This work describes variation of element concentration in surface water of a subarctic organic-rich lake during the diurnal cycle of photosynthesis. An unusually hot summer 2010 in European part of subarctic Russia produced elevated surface water temperature (28-30 °C) and caused massive cyanobacterial bloom. Diurnal variation of ~40 dissolved macro and trace elements and organic carbon were recorded in the humic Lake Svyatoe in the White Sea drainage basin. Two days continuous measurements with 3 h sampling steps at the surface (0.5 m) allowed tracing cyanobacterial activity via pH and O₂ measurement and revealed constant concentrations (within ±20-30%) of all major elements (Na, Mg, Cl, SO₄, K, Ca), organic and inorganic carbon and most trace elements (Li, B, Sc, Ti, Ni, Cu, Ga, As, Rb, Sr, Y, Zr, Mo, Sb, medium and heavy REEs, Hf, Pb, Th, U). The concentration of Mn demonstrated a factor of 3 decrease during the day following Mn adsorption onto cyanobacterial cells due to ~1 pH unit raise during the photosynthesis and Mn release during the night due to desorption from the cell surface. The role of Mn(II) photo-oxidation by reactive oxygen species could be also pronounced, although its contribution to Mn diurnal variation was much smaller than the adsorption at the cell surfaces. Similar pattern, but with much lesser variations (c.a., 10-20%), was recorded for Ba and Fe. On-site ultrafiltration technique allowed to distinguish between low molecular weight (LMW) complexes (80-90%) with HMW allochthonous organics, independent on the diel photosynthetic cycle. Finally, biologically-relevant metals (Cu, Co, Cr, V, and Ni) demonstrated significant variations of colloidal fractions (from 10 to 60%) not directly related to the photosynthesis. The majority of possible metal nutrients, being strongly associated with organic and organo-mineral colloids do not exhibit any measurable concentration variation during photosynthesis. The two types of element behavior

  1. Wheel running improves REM sleep and attenuates stress-induced flattening of diurnal rhythms in F344 rats.

    Science.gov (United States)

    Thompson, Robert S; Roller, Rachel; Greenwood, Benjamin N; Fleshner, Monika

    2016-05-01

    Regular physical activity produces resistance to the negative health consequences of stressor exposure. One way that exercise may confer stress resistance is by reducing the impact of stress on diurnal rhythms and sleep; disruptions of which contribute to stress-related disease including mood disorders. Given the link between diurnal rhythm disruptions and stress-related disorders and that exercise both promotes stress resistance and is a powerful non-photic biological entrainment cue, we tested if wheel running could reduce stress-induced disruptions of sleep/wake behavior and diurnal rhythms. Adult, male F344 rats with or without access to running wheels were instrumented for biotelemetric recording of diurnal rhythms of locomotor activity, heart rate, core body temperature (CBT), and sleep (i.e. REM, NREM, and WAKE) in the presence of a 12 h light/dark cycle. Following 6 weeks of sedentary or exercise conditions, rats were exposed to an acute stressor known to disrupt diurnal rhythms and produce behaviors associated with mood disorders. Prior to stressor exposure, exercise rats had higher CBT, more locomotor activity during the dark cycle, and greater %REM during the light cycle relative to sedentary rats. NREM and REM sleep were consolidated immediately following peak running to a greater extent in exercise, compared to sedentary rats. In response to stressor exposure, exercise rats expressed higher stress-induced hyperthermia than sedentary rats. Stressor exposure disrupted diurnal rhythms in sedentary rats; and wheel running reduced these effects. Improvements in sleep and reduced diurnal rhythm disruptions following stress could contribute to the health promoting and stress protective effects of exercise.

  2. Pathophysiology of diurnal drooling in Parkinson's disease

    NARCIS (Netherlands)

    Kalf, J.G.; Munneke, M.; Engel-Hoek, L. van den; Swart, B.J.M. de; Borm, G.F.; Bloem, B.R.; Zwarts, M.J.

    2011-01-01

    Drooling is an incapacitating feature of Parkinson's disease. Better pathophysiological insights are needed to improve treatment. In this study, we tested the hypothesis that the cause of drooling is multifactorial. We examined 15 patients with Parkinson's disease with distinct diurnal saliva loss

  3. Diurnal variability of upper ocean temperature and heat budget in ...

    Indian Academy of Sciences (India)

    These data have been analysed to examine the diurnal variability of upper oceanic heat budget and to estimate the eddy diffusivity coefficient of heat in the upper layer. Diurnal variation of near-surface temperature is typical at northern location (13°N) with a range of 0.5°C while the diurnal range of temperature is enhanced ...

  4. On the diurnal ranges of Sea Surface Temperature (SST)

    Indian Academy of Sciences (India)

    This paper describes the variability in the diurnal range of SST in the north Indian Ocean using in situ measurements and tests the suitability of simple regression models in estimating the diurnal range.SST measurements obtained from 1556 drifting and 25 moored buoys were used to determine the diurnal range of SSTs.

  5. Diurnal oscillation of SBE expression in sorghum endosperm

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chuanxin; Mutisya, J.; Rosenquist, S.; Baguma, Y.; Jansson, C.

    2009-01-15

    Spatial and temporal expression patterns of the sorghum SBEI, SBEIIA and SBEIIB genes, encoding, respectively, starch branching enzyme (SBE) I, IIA and IIB, in the developing endosperm of sorghum (Sorghum bicolor) were studied. Full-length genomic and cDNA clones for sorghum was cloned and the SBEIIA cDNA was used together with gene-specific probes for sorghum SBEIIB and SBEI. In contrast to sorghum SBEIIB, which was expressed primarily in endosperm and embryo, SBEIIA was expressed also in vegetative tissues. All three genes shared a similar temporal expression profile during endosperm development, with a maximum activity at 15-24 days after pollination. This is different from barley and maize where SBEI gene activity showed a significantly later onset compared to that of SBEIIA and SBEIIB. Expression of the three SBE genes in the sorghum endosperm exhibited a diurnal rhythm during a 24-h cycle.

  6. Consequences of incongruency in diurnally varying resources for seedlings of Rumex crispus (Polygonaceae).

    Science.gov (United States)

    Cavender-Bares, J M; Voss, P B; Bazzaz, F A

    1998-09-01

    The incongruency of diurnally varying resources essential to plants may detrimentally affect plants early in their development as indicated by reduced water use efficiency and carbon gain. Typical diurnal patterns of light and CO(2) availability in a midsized temperate herbaceous or forest gap were simulated in specially designed growth chambers. A sinusoidally varying CO(2) treatment (400 ppm minimum, 800 ppm maximum) approximated the diurnal cycle of CO(2) at the soil surface, while a steady-state CO(2) treatment (600 ppm) with the same average CO(2 )concentration provided a control. Crossed with these two CO(2) treatments were two light regimes, one with 3 h of high light (850 μmol·m·s) in the morning (west side of a gap), and the other with 3 h of high light in the afternoon (east side). All treatments received baseline low light (55 μmol·m·s) for 14 h during the day. Rumex crispus was selected as a model species because of its rosette leaves, which grow close to the ground where diurnal CO(2 )variation is greatest. The relative timing of diurnal variations in light and CO(2) significantly affected seedling water use efficiency, carbon gain, and morphology. Total biomass, photosynthetic rates, daily integrated carbon, water use efficiency, and leaf area were enhanced by morning exposure to high light. Seedlings that were exposed to peak values of light and CO(2) incongruently, i.e., those plants receiving intense afternoon light with diurnally varying CO(2), were detrimentally affected relative to control plants receiving intense afternoon light with steady-state CO(2). The results of this experiment indicate that the incongruent availability of required resources-such as light and CO(2)-can detrimentally affect performance relative to when resources are congruent. These contrasting resource regimes can occur on the east and west side of gaps.

  7. Impact of assimilation window length on diurnal features in a Mars atmospheric analysis

    Directory of Open Access Journals (Sweden)

    Yongjing Zhao

    2015-05-01

    Full Text Available Effective simulation of diurnal variability is an important aspect of many geophysical data assimilation systems. For the Martian atmosphere, thermal tides are particularly prominent and contribute much to the Martian atmospheric circulation, dynamics and dust transport. To study the Mars diurnal variability and Mars thermal tides, the Geophysical Fluid Dynamics Laboratory Mars Global Climate Model with the 4D-local ensemble transform Kalman filter (4D-LETKF is used to perform an analysis assimilating spacecraft temperature retrievals. We find that the use of a ‘traditional’ 6-hr assimilation cycle induces spurious forcing of a resonantly enhanced semi-diurnal Kelvin waves represented in both surface pressure and mid-level temperature by forming a wave 4 pattern in the diurnal averaged analysis increment that acts as a ‘topographic’ stationary forcing. Different assimilation window lengths in the 4D-LETKF are introduced to remove the artificially induced resonance. It is found that short assimilation window lengths not only remove the spurious resonance, but also push the migrating semi-diurnal temperature variation at 50 Pa closer to the estimated ‘true’ tides even in the absence of a radiatively active water ice cloud parameterisation. In order to compare the performance of different assimilation window lengths, short-term to mid-range forecasts based on the hour 00 and 12 assimilation are evaluated and compared. Results show that during Northern Hemisphere summer, it is not the assimilation window length, but the radiatively active water ice clouds that influence the model prediction. A ‘diurnal bias correction’ that includes bias correction fields dependent on the local time is shown to effectively reduce the forecast root mean square differences between forecasts and observations, compensate for the absence of water ice cloud parameterisation and enhance Martian atmosphere prediction. The implications of these results for

  8. SMLTM simulations of the diurnal tide: comparison with UARS observations

    Directory of Open Access Journals (Sweden)

    R. A. Akmaev

    1997-09-01

    Full Text Available Wind and temperature observations in the mesosphere and lower thermosphere (MLT from the Upper Atmosphere Research Satellite (UARS reveal strong seasonal variations of tides, a dominant component of the MLT dynamics. Simulations with the Spectral mesosphere/lower thermosphere model (SMLTM for equinox and solstice conditions are presented and compared with the observations. The diurnal tide is generated by forcing specified at the model lower boundary and by in situ absorption of solar radiation. The model incorporates realistic parameterizations of physical processes including various dissipation processes important for propagation of tidal waves in the MLT. A discrete multi-component gravity-wave parameterization has been modified to account for seasonal variations of the background temperature. Eddy diffusion is calculated depending on the gravity-wave energy deposition rate and stability of the background flow. It is shown that seasonal variations of the diurnal-tide amplitudes are consistent with observed variations of gravity-wave sources in the lower atmosphere.

  9. SMLTM simulations of the diurnal tide: comparison with UARS observations

    Directory of Open Access Journals (Sweden)

    R. A. Akmaev

    Full Text Available Wind and temperature observations in the mesosphere and lower thermosphere (MLT from the Upper Atmosphere Research Satellite (UARS reveal strong seasonal variations of tides, a dominant component of the MLT dynamics. Simulations with the Spectral mesosphere/lower thermosphere model (SMLTM for equinox and solstice conditions are presented and compared with the observations. The diurnal tide is generated by forcing specified at the model lower boundary and by in situ absorption of solar radiation. The model incorporates realistic parameterizations of physical processes including various dissipation processes important for propagation of tidal waves in the MLT. A discrete multi-component gravity-wave parameterization has been modified to account for seasonal variations of the background temperature. Eddy diffusion is calculated depending on the gravity-wave energy deposition rate and stability of the background flow. It is shown that seasonal variations of the diurnal-tide amplitudes are consistent with observed variations of gravity-wave sources in the lower atmosphere.

  10. Atmospheric mercury in the Southern Hemisphere tropics: seasonal and diurnal variations and influence of inter-hemispheric transport

    Directory of Open Access Journals (Sweden)

    D. Howard

    2017-09-01

    Full Text Available Mercury is a toxic element of serious concern for human and environmental health. Understanding its natural cycling in the environment is an important goal towards assessing its impacts and the effectiveness of mitigation strategies. Due to the unique chemical and physical properties of mercury, the atmosphere is the dominant transport pathway for this heavy metal, with the consequence that regions far removed from sources can be impacted. However, there exists a dearth of long-term monitoring of atmospheric mercury, particularly in the tropics and Southern Hemisphere. This paper presents the first 2 years of gaseous elemental mercury (GEM measurements taken at the Australian Tropical Atmospheric Research Station (ATARS in northern Australia, as part of the Global Mercury Observation System (GMOS. Annual mean GEM concentrations determined at ATARS (0.95 ± 0.12 ng m−3 are consistent with recent observations at other sites in the Southern Hemisphere. Comparison with GEM data from other Australian monitoring sites suggests a concentration gradient that decreases with increasing latitude. Seasonal analysis shows that GEM concentrations at ATARS are significantly lower in the distinct wet monsoon season than in the dry season. This result provides insight into alterations of natural mercury cycling processes as a result of changes in atmospheric humidity, oceanic/terrestrial fetch, and convective mixing, and invites future investigation using wet mercury deposition measurements. Due to its location relative to the atmospheric equator, ATARS intermittently samples air originating from the Northern Hemisphere, allowing an opportunity to gain greater understanding of inter-hemispheric transport of mercury and other atmospheric species. Diurnal cycles of GEM at ATARS show distinct nocturnal depletion events that are attributed to dry deposition under stable boundary layer conditions. These cycles provide strong further evidence supportive of

  11. Atmospheric mercury in the Southern Hemisphere tropics: seasonal and diurnal variations and influence of inter-hemispheric transport

    Science.gov (United States)

    Howard, Dean; Nelson, Peter F.; Edwards, Grant C.; Morrison, Anthony L.; Fisher, Jenny A.; Ward, Jason; Harnwell, James; van der Schoot, Marcel; Atkinson, Brad; Chambers, Scott D.; Griffiths, Alan D.; Werczynski, Sylvester; Williams, Alastair G.

    2017-09-01

    Mercury is a toxic element of serious concern for human and environmental health. Understanding its natural cycling in the environment is an important goal towards assessing its impacts and the effectiveness of mitigation strategies. Due to the unique chemical and physical properties of mercury, the atmosphere is the dominant transport pathway for this heavy metal, with the consequence that regions far removed from sources can be impacted. However, there exists a dearth of long-term monitoring of atmospheric mercury, particularly in the tropics and Southern Hemisphere. This paper presents the first 2 years of gaseous elemental mercury (GEM) measurements taken at the Australian Tropical Atmospheric Research Station (ATARS) in northern Australia, as part of the Global Mercury Observation System (GMOS). Annual mean GEM concentrations determined at ATARS (0.95 ± 0.12 ng m-3) are consistent with recent observations at other sites in the Southern Hemisphere. Comparison with GEM data from other Australian monitoring sites suggests a concentration gradient that decreases with increasing latitude. Seasonal analysis shows that GEM concentrations at ATARS are significantly lower in the distinct wet monsoon season than in the dry season. This result provides insight into alterations of natural mercury cycling processes as a result of changes in atmospheric humidity, oceanic/terrestrial fetch, and convective mixing, and invites future investigation using wet mercury deposition measurements. Due to its location relative to the atmospheric equator, ATARS intermittently samples air originating from the Northern Hemisphere, allowing an opportunity to gain greater understanding of inter-hemispheric transport of mercury and other atmospheric species. Diurnal cycles of GEM at ATARS show distinct nocturnal depletion events that are attributed to dry deposition under stable boundary layer conditions. These cycles provide strong further evidence supportive of a multi-hop model of GEM

  12. Global distributions of diurnal and semi-diurnal tides: observations from HRDI-UARS of the MLT region

    Directory of Open Access Journals (Sweden)

    A. H. Manson

    Full Text Available HRDI (High Resolution Doppler Interferometer-UARS winds data have been analyzed in 4° latitude by 10° longitude cells at 96 km to obtain global contour maps of solar-tidal amplitudes and phases, and also mean winds. The solstices June–July (1993, December–January (1993–1994, and one equinox September–October (1994 are shown. 

    The 24-h diurnal tide that maximizes near the 20–25° latitude has significant seasonal changes with equinoctial maxima, and very clear longitudinal variability. Maxima are very clear over the oceans. In contrast, the 12-h semi-diurnal tides that maximize near the 40–55° latitude have very strong seasonal changes with winter maxima, and more modest longitudinal changes. The similarities with MLT (mesosphere-lower thermosphere radar observations (90 km and the GSWM (Global Scale Wave Model are very satisfactory. The mean winds are consistent with expectations and show clear poleward flow from summer to winter hemispheres in the solstices.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides Radio science (remote sensing

  13. Global distributions of diurnal and semi-diurnal tides: observations from HRDI-UARS of the MLT region

    Directory of Open Access Journals (Sweden)

    A. H. Manson

    2002-11-01

    Full Text Available HRDI (High Resolution Doppler Interferometer-UARS winds data have been analyzed in 4° latitude by 10° longitude cells at 96 km to obtain global contour maps of solar-tidal amplitudes and phases, and also mean winds. The solstices June–July (1993, December–January (1993–1994, and one equinox September–October (1994 are shown.  The 24-h diurnal tide that maximizes near the 20–25° latitude has significant seasonal changes with equinoctial maxima, and very clear longitudinal variability. Maxima are very clear over the oceans. In contrast, the 12-h semi-diurnal tides that maximize near the 40–55° latitude have very strong seasonal changes with winter maxima, and more modest longitudinal changes. The similarities with MLT (mesosphere-lower thermosphere radar observations (90 km and the GSWM (Global Scale Wave Model are very satisfactory. The mean winds are consistent with expectations and show clear poleward flow from summer to winter hemispheres in the solstices.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides Radio science (remote sensing

  14. Timing the tides: genetic control of diurnal and lunar emergence times is correlated in the marine midge Clunio marinus.

    Science.gov (United States)

    Kaiser, Tobias S; Neumann, Dietrich; Heckel, David G

    2011-05-20

    The intertidal zone of seacoasts, being affected by the superimposed tidal, diurnal and lunar cycles, is temporally the most complex environment on earth. Many marine organisms exhibit lunar rhythms in reproductive behaviour and some show experimental evidence of endogenous control by a circalunar clock, the molecular and genetic basis of which is unexplored. We examined the genetic control of lunar and diurnal rhythmicity in the marine midge Clunio marinus (Chironomidae, Diptera), a species for which the correct timing of adult emergence is critical in natural populations. We crossed two strains of Clunio marinus that differ in the timing of the diurnal and lunar rhythms of emergence. The phenotype distribution of the segregating backcross progeny indicates polygenic control of the lunar emergence rhythm. Diurnal timing of emergence is also under genetic control, and is influenced by two unlinked genes with major effects. Furthermore, the lunar and diurnal timing of emergence is correlated in the backcross generation. We show that both the lunar emergence time and its correlation to the diurnal emergence time are adaptive for the species in its natural environment. The correlation implies that the unlinked genes affecting lunar timing and the two unlinked genes affecting diurnal timing could be the same, providing an unexpectedly close interaction of the two clocks. Alternatively, the genes could be genetically linked in a two-by-two fashion, suggesting that evolution has shaped the genetic architecture to stabilize adaptive combinations of lunar and diurnal emergence times by tightening linkage. Our results, the first on genetic control of lunar rhythms, offer a new perspective to explore their molecular clockwork.

  15. Combined diurnal variations of discharge and hydrochemistry of the Isunnguata Sermia outlet, Greenland Ice Sheet

    Science.gov (United States)

    Graly, Joseph; Harrington, Joel; Humphrey, Neil

    2017-05-01

    In order to examine daily cycles in meltwater routing and storage in the Isunnguata Sermia outlet of the Greenland Ice Sheet, variations in outlet stream discharge and in major element hydrochemistry were assessed over a 6-day period in July 2013. Over 4 days, discharge was assessed from hourly photography of the outlet from multiple vantages, including where midstream naled ice provided a natural gauge. pH, electrical conductivity, suspended sediment, and major element and anion chemistry were measured in samples of stream water collected every 3 h.Photography and stream observations reveal that although river width and stage have only slight diurnal variation, there are large diurnal changes in discharge shown by the doubling in width of what we term the active channel, which is characterized by large standing waves and fast flow. The concentration of dissolved solutes follows a sinusoidal diurnal cycle, except for large and variable increases in dissolved solutes during the stream's waning flow. Solute concentrations vary by ˜ 30 % between diurnal minima and maxima. Discharge maxima and minima lag temperature and surface melt by 3-7 h; diurnal solute concentration minima and maxima lag discharge by 3-6 h.This phase shift between discharge and solute concentration suggests that during high flow, water is either encountering more rock material or is stored in longer contact with rock material. We suggest that expansion of a distributed subglacial hydrologic network into seldom accessed regions during high flow could account for these phenomena, and for a spike of partial silicate reaction products during waning flow, which itself suggests a pressure threshold-triggered release of stored water.

  16. The Tokar Gap Jet: Regional Circulation, Diurnal Variability, and Moisture Transport Based on Numerical Simulations

    KAUST Repository

    Davis, Shannon R.

    2015-05-14

    The structure, variability, and regional connectivity of the Tokar Gap jet (TGJ) are described using WRF Model analyses and supporting atmospheric datasets from the East African–Red Sea–Arabian Peninsula (EARSAP) region during summer 2008. Sources of the TGJ’s unique quasi-diurnal nature and association with atypically high atmospheric moisture transport are traced back to larger-scale atmospheric dynamics influencing its forcing. These include seasonal shifts in the intertropical convergence zone (ITCZ), variability of the monsoon and North African wind regimes, and ties to other orographic flow patterns. Strong modulation of the TGJ by regional processes such as the desert heating cycle, wind convergence at the ITCZ surface front, and the local land–sea breeze cycle are described. Two case studies present the interplay of these influences in detail. The first of these was an “extreme” gap wind event on 12 July, in which horizontal velocities in the Tokar Gap exceeded 26 m s−1 and the flow from the jet extended the full width of the Red Sea basin. This event coincided with development of a large mesoscale convective complex (MCC) and precipitation at the entrance of the Tokar Gap as well as smaller gaps downstream along the Arabian Peninsula. More typical behavior of the TGJ during the 2008 summer is discussed using a second case study on 19 July. Downwind impact of the TGJ is evaluated using Lagrangian model trajectories and analysis of the lateral moisture fluxes (LMFs) during jet events. These results suggest means by which TGJ contributes to large LMFs and has potential bearing upon Sahelian rainfall and MCC development.

  17. Annual and diurnal precipitation bimodal distributions as simulated by WRF-based CORDEX-Cetral America

    Science.gov (United States)

    Angel, M. C.; Mejia, J.; Chang, H. I.; Ochoa, C. A.; Castro, C. L.

    2017-12-01

    We examine the ability of a regional climate model (RCM) to simulate the observed annual and diurnal cycles of precipitation over Central America (CA), the Caribbean Sea and NW South America (NWSA). The region's annual cycle is dominated by a bimodal precipitation annual cycle: over CA and the Caribbean, the mid-summer drought suppresses the rainy season in July-August; over the NWSA, and more pronouncedly over the Andes, the ITCZ meridional migration is argue to dominate the bimodal distribution of the annual cycle. The intricate land-ocean distribution, the complex terrain, and the long lasting mesoscale convective systems have been related to intricate bimodal diurnal distribution of precipitation over the far eastern Pacific and NWSA. A CORDEX-CA simulation based on the Weather and Research Forecasting (WRF) model at 25 km grid size driven by ERA-Interim reanalysis for the period 1979-2015 was implemented. The simulations were evaluated using surface observations and the research-based High-Resolution Satellite Precipitation Product from TRMM (3B42) and CMORPH. We use spectral analysis to estimate the mean phase and amplitude spatial patterns at annual and diurnal time scales. We further contrast the consistencies and differences using more focus and higher resolution simulations based on WRF and ERA-Interim at 10km and convection-permitting simulations (<4 km grid sizes). The research discusses the flow and orographic dependencies on the ability to adequately simulate the annual and diurnal bimodal distributions of precipitation. These comparisons provide a high-level validation of the WRF-based CORDEX-CA's ability to simulate one of the rainniest region on earth and its basic but challenging small-scale spatial-temporal climate variations.

  18. Prediction of the antidepressant response to total sleep deprivation of depressed patients: longitudinal versus single day assessment of diurnal mood variation.

    Science.gov (United States)

    Reinink, E; Bouhuys, A L; Gordijn, M C; Van Den Hoofdakker, R H

    1993-10-01

    The relationship between diurnal variation of mood and the clinical response to total sleep deprivation (TSD) was investigated in 43 depressed patients. The question asked was whether the propensity to produce diurnal variations of mood or the actual mood course on the day before TSD determines the clinical response to TSD. Patients rated their mood three times daily during an experimental period of 56 days. The frequency as well as the amplitude of daily mood changes were assessed during this period. For each patient six TSDs were scheduled: two after days with a positive mood course, two after a negative mood course, and two after days without a diurnal change of mood. This strategy allowed comparisons of TSD responses within patients. Moreover, longitudinally and retrospectively assessed diurnal variation were compared with each other. It was found that patients vary largely in the occurrence of diurnal variations of mood. The propensity to produce diurnal variations either in terms of frequency or amplitude was positively correlated with the response to TSD. Within patients no differences were found in responses to TSDs applied after days with diurnal variations (positive or negative) or without diurnal variations. A second aim was to get more insight into the mechanism relating diurnal variations of mood and the TSD response. Therefore, the interrelatedness of various measures of diurnal variations, such as amplitudes and frequencies of positive or negative diurnal mood changes, was studied, as well as the relationships of these variables with TSD responses. On the basis of the strong interrelatedness it is suggested that they all reflect the same underlying mechanism, to be symbolized by an oscillator, producing positive daily fluctuations of mood.

  19. Diurnal variability of gas phase and surface water ethanol in southeastern North Carolina, USA

    Science.gov (United States)

    Kieber, R. J.; Powell, J. P.; Foley, L.; Mead, R. N.; Willey, J. D.; Avery, G. B.

    2017-11-01

    Diurnal variations in gas phase and surface water concentrations of ethanol and acetaldehyde were investigated at five locations in southeastern North Carolina, USA. There were distinct diurnal oscillations observed in gas phase concentrations with maxima occurring in late afternoon suggesting that photochemical production is an important process in the cycling of these analytes in the troposphere. The rapid decrease in concentrations after the mid day maximum suggests that there is also an atmospheric photochemical sink for both analytes most likely involving photo produced hydroxyl radicals with a half-life on the order of hours rather than days at ground level. Ethanol concentrations in the surface microlayer taken at the same time as gas phase samples had a very similar diurnal profile suggesting photochemical processes, in addition to atmospheric deposition, play a role in the aqueous phase cycling of both analytes. The concentration of ethanol and acetaldehyde increased significantly in flasks containing freshwater collected from the Cape Fear River exposed to simulated sunlight for 6 h underscoring the importance of in situ photochemical production. Results of this study are significant because they represent the first simultaneous analyses of the temporal variability of ethanol and acetaldehyde concentrations in the gas and aqueous phases. These measurements are essential in order to better define the processes involved in the global biogeochemical cycling of ethanol both now and in the future as our use of the biofuel continues to grow.

  20. A Broad-Area Method for the Diurnal Characterisation of Upwelling Medium Wave Infrared Radiation

    Directory of Open Access Journals (Sweden)

    Bryan Hally

    2017-02-01

    Full Text Available Fire detection from satellite sensors relies on an accurate estimation of the unperturbed state of a target pixel, from which an anomaly can be isolated. Methods for estimating the radiation budget of a pixel without fire depend upon training data derived from the location’s recent history of brightness temperature variation over the diurnal cycle, which can be vulnerable to cloud contamination and the effects of weather. This study proposes a new method that utilises the common solar budget found at a given latitude in conjunction with an area’s local solar time to aggregate a broad-area training dataset, which can be used to model the expected diurnal temperature cycle of a location. This training data is then used in a temperature fitting process with the measured brightness temperatures in a pixel, and compared to pixel-derived training data and contextual methods of background temperature determination. Results of this study show similar accuracy between clear-sky medium wave infrared upwelling radiation and the diurnal temperature cycle estimation compared to previous methods, with demonstrable improvements in processing time and training data availability. This method can be used in conjunction with brightness temperature thresholds to provide a baseline for upwelling radiation, from which positive thermal anomalies such as fire can be isolated.

  1. Pulse pressure and diurnal blood pressure variation

    DEFF Research Database (Denmark)

    Knudsen, Søren Tang; Poulsen, Per Løgstrup; Hansen, Klavs Würgler

    2002-01-01

    BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between...... retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence...... and 3-6 had higher PP and blunted diurnal BP variation: night PP 55 +/- 10 mm Hg, 64 +/- 10 mm Hg, 61 +/- 15 mm Hg, P groups (45 normo-, 19 micro-, and 15...

  2. Diurnal behaviour of water on Mars

    Science.gov (United States)

    Flasar, F. M.; Goody, R. M.

    1976-01-01

    A numerical model of the diurnal transport of water across the Martian surface is developed. The atmospheric boundary layer is modeled in terms of local radiative-convective processes, and radiative effects of ice fogs near the surface are included. Diffusion of water in the ground is treated for the cases of adsorption and condensation. The model is applied to the diurnal variation of water vapor in the atmosphere as observed by Barker (1974). The morning rise in the amount of water vapor can be explained in terms of the evaporation of ground fogs. The evening decrease is compatible with the model if adsorption dominates in the soil. The average level of vapor concentration requires that the atmosphere above the boundary layer be relatively dry. The ground fogs persist until midmorning and should be observable. Some consequences of these conclusions are discussed.

  3. The Quality of Life Analysis with Regard to Circadian and Diurnal Rhythm of Pubescents and Adolescents in Children's Homes in the Region of Pardubice.

    OpenAIRE

    ŠTORKOVÁ, Tereza

    2014-01-01

    This thesis deals with the quality of life of pubescent and adolescent in children's homes in the Pardubice region with regard to circadian and diurnal rhythms. In the theoretical part we define in detail the concept of quality of life, pubescence, and adolescence, biorhythms with a division between circadian and diurnal rhythms, sleep and institutional care. More attention is paid to sleep, its importance, quality and above all sleep cycles that are directly associated with the subsequent re...

  4. Temperature, extreme precipitation, and diurnal rainfall changes in the urbanized Jakarta city during the past 130 years

    NARCIS (Netherlands)

    Siswanto, [Unknown; van Oldenborgh, G.J.; van der Schrier, G.; Jilderda, R.; van den Hurk, B.J.J.M.

    2016-01-01

    Using a newly available 134-years long record of daily and 114-years hourly observations at Jakarta observatory, trends and variability in temperature, extreme precipitation, and changes in the diurnal cycle over Jakarta have been analysed. Although the number of days with rainfall has decreased

  5. Sleep deprivation and caffeine treatment potentiate photic resetting of the master circadian clock in a diurnal rodent

    NARCIS (Netherlands)

    Kumar Jha, Pawan; Bouâouda, Hanan; Gourmelen, Sylviane; Dumont, Stephanie; Fuchs, Fanny; Goumon, Yannick; Bourgin, Patrice; Kalsbeek, A.; Challet, Etienne

    Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light-dark cycle. However, non-photic factors, such as behavioural arousal and metabolic cues, can also phase-shift the master clock in the suprachiasmatic nuclei (SCN) and/or reduce the synchronizing

  6. Sleep Deprivation and Caffeine Treatment Potentiate Photic Resetting of the Master Circadian Clock in a Diurnal Rodent

    NARCIS (Netherlands)

    Jha, Pawan Kumar; Bouâouda, Hanan; Gourmelen, Sylviane; Dumont, Stephanie; Fuchs, Fanny; Goumon, Yannick; Bourgin, Patrice; Kalsbeek, Andries; Challet, Etienne

    2017-01-01

    Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light/dark cycle. However, nonphotic factors, such as behavioral arousal and metabolic cues, can also phase shift the master clock in the suprachiasmatic nuclei (SCNs) and/or reduce the synchronizing

  7. natalensis) and diurn'al (Rhabdomys pumilio)

    African Journals Online (AJOL)

    Heat production by means of oxygen consumption (Vo,) was measured at different ambient temperatures (T J 6-34 °e in both species. The thermo neutral zone for both speCies was found to be at T. = 32 ± 1 °e. Below the lower critical point. Vo. for the diurnal species (R. pumilio) was significantly higher. (p

  8. [Diurnal rythm of locomotor activity in Admetus pumilio C. Koch (Arach., Amblypygi) from the neotropical rain forest. II].

    Science.gov (United States)

    Beck, L

    1972-03-01

    The locomotor activity of the exclusively dark-active species Admetus pumilio shows a bigeminal type of diurnal rhythm, modified by an interposed third peak of activity. In accordance with Aschoff's rule, the period length depends on light intensity and is shortened in DD. The phase-angle difference must be determined separately for each form of activity. The first movements at the resting place ("awakening") and departure from it are the most readily identifiable forms of activity. Awakening takes place earlier and earlier with decreasing light intensity, thus diverging from departure more and more.Differing degrees of activity in LL and LD of different intensities show that light stimulates or inhibits depending on its intensity. The turning point between the two effects lies between 10 -2 and 10 -3 lx. Below this limit differences in light intensity are not discerned, although LL is well discerned from LD.Diurnal temperature cycles with amplitudes up to 8° C are unable to synchronize the circadian rhythm of Admetus, but may have a strongly masking effect. Different levels of constant temperatures influence the phase-angle differences, which become increasingly positive with rising temperature. Activity also increases with temperature, but decreases in the extra-optimal range above approximately 30° C. The L-phase/D-phase ratio of activity shows a maximum at about 26° C.In Admetus the dependence of activity parameters upon light intensity is unidirectional and shows no optima. In contrast to the findings by Erkert (1967) is discussed that optima are only realized in dusk active animals and are lacking in day-active and night-active species.

  9. Seasonal and diurnal variations of Hg° over New England

    Directory of Open Access Journals (Sweden)

    J. D. Hegarty

    2008-03-01

    Full Text Available Factors influencing diurnal to interannual variability in Hg° over New England were investigated using multi-year measurements conducted by AIRMAP at the Thompson Farm (TF coastal site, an inland elevated site at Pac Monadnock (PM, and two month measurements on Appledore Island (AI in the Gulf of Maine. Mixing ratios of Hg° at TF showed distinct seasonality with maxima in March and minima in October. Hg° at AI tracked the trend at TF but with higher minima, while at PM the diurnal and annual cycles were dampened. In winter, Hg° was correlated most strongly with CO and NOy, indicative of anthropogenic emissions as their primary source. Our analysis indicates that Hg° had a regional background level of ~160 fmol/mol in winter, a dry deposition velocity of ~0.20 cm s−1 with a ~16 day lifetime in the coastal boundary layer in summer. The influence of oceanic emissions on ambient Hg° levels was identified using the Hg°-CHBr3 correlation at both TF and AI. Moreover, the lower Hg° levels and steeper decreasing warm season trend at TF (0.5–0.6 fmol/mol d−1 compared to PM (0.2–0.3 fmol/mol d−1 likely reflected the impact of marine halogen chemistry. Large interannual variability in warm season Hg° levels in 2004 versus 2005/2006 may be due to the role of precipitation patterns in influencing surface evasion of Hg°. In contrast, changes in wintertime maximum levels of Hg° were small compared to drastic reductions in CO, CO2, NOy, and SO2 from 2004/2005 to 2006/2007. These trends could be explained by a homogeneous distribution of Hg° over North American in winter due to its long lifetime and/or rapid removal of reactive mercury from anthropogenic sources. We caution that during warmer winters, the Hg°-CO slope possibly reflects Hg° loss relative to changes in CO more than their emission ratio.

  10. Cumulative ozone effect on canopy stomatal resistance and the impact on boundary layer dynamics and CO2 assimilation at the diurnal scale: A case study for grassland in the Netherlands

    NARCIS (Netherlands)

    Super, I.; Vilà-Guerau De Arellano, J.; Krol, M.C.

    2015-01-01

    Biological, chemical, and dynamical processes occurring at the surface strongly interact at diurnal scales. Therefore, this study examines the seasonal ozone impact on stomatal resistance, surface energy balance, boundary layer dynamics, and CO2 assimilation at this (sub)diurnal scale under changing

  11. On the Diurnal Periodicity of Representative Earthquakes in Greece: Comparison of Data from Different Observation Systems

    Science.gov (United States)

    Desherevskii, A. V.; Sidorin, A. Ya.

    2017-12-01

    Due to the initiation of the Hellenic Unified Seismic Network (HUSN) in late 2007, the quality of observation significantly improved by 2011. For example, the representative magnitude level considerably has decreased and the number of annually recorded events has increased. The new observational system highly expanded the possibilities for studying regularities in seismicity. In view of this, the authors revisited their studies of the diurnal periodicity of representative earthquakes in Greece that was revealed earlier in the earthquake catalog before 2011. We use 18 samples of earthquakes of different magnitudes taken from the catalog of Greek earthquakes from 2011 to June 2016 to derive a series of the number of earthquakes for each of them and calculate its average diurnal course. To increase the reliability of the results, we compared the data for two regions. With a high degree of statistical significance, we have obtained that no diurnal periodicity can be found for strongly representative earthquakes. This finding differs from the estimates obtained earlier from an analysis of the catalog of earthquakes at the same area for 1995-2004 and 2005-2010, i.e., before the initiation of the Hellenic Unified Seismic Network. The new results are consistent with the hypothesis of noise discrimination (observational selection) explaining the cause of the diurnal variation of earthquakes with different sensitivity of the seismic network in daytime and nighttime periods.

  12. Studying Diurnal Variations of Aerosols with NASA MERRA-2 Reanalysis Data

    Science.gov (United States)

    Shen, Suhung; Ostrenga, Dana M.; Zeng, Jian; Vollmer, Bruce E.

    2018-01-01

    Aerosols play an important role in atmospheric dynamics, climate variations, and Earth's energy cycle by altering the radiation balance in the atmosphere through interaction with clouds, providing fertilizer for forests and canopy, and as a supply of iron to the ocean over long time periods. Studies suggest that much of the feedback between dust aerosols and dynamics is associated with diurnal and synoptic scale variability. However, the lack of sub-daily resolution of aerosols from satellite observations makes it difficult to study the diurnal characteristics, especially over tropical and subtropical regions. Investigation of this topic utilizes over 37 years of simulated global aerosol products from NASA atmospheric reanalysis, in the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data set, available from NASA Goddard Earth Science Data and Information Services Center (GES DISC). MERRA-2 covers the period 1980-present, and is continuing as an ongoing climate analysis. Aerosol assimilation is included throughout the period, using data from MODIS, MISR, AERONET, and AVHRR (in the pre-EOS period). The aerosols are assimilated using the MERRA-2 aerosol model, which interacts directly with radiation parameterization, and is radiatively coupled with atmospheric model dynamics in the Goddard Earth Observing System Model, Version 5 (GEOS-5). Hourly, monthly, and monthly diurnal data are available at spatial resolution of 0.5o x 0.625o (latitude x longitude). By using MERRA-2 hourly and monthly diurnal products, different aerosol diurnal variabilities are observed over North America, Africa, Asia, and Australia, that may be due to different meteorological conditions and aerosol sources. The presentation will also provide an overview of MERRA-2 data services at GES DISC, such as how to find and download data, and how to quickly visualize and analyze data online with Giovanni.

  13. Water stress induced breakdown of carbon-water relations: indicators from diurnal FLUXNET patterns

    Science.gov (United States)

    Nelson, Jacob; Carvalhais, Nuno; Migliavacca, Mirco; Reichstein, Markus; Jung, Martin

    2017-04-01

    Understanding of terrestrial carbon and water cycles is currently hampered by an uncertainty in how to capture the large variety of plant responses to drought across climates, ecological strategies, and environments. In FLUXNET, many sites do not uniformly report the ancillary variables needed to study drought response physiology such as soil moisture, sap flux, or species composition. In this sense, the use of diurnal patters to derive clues on ecosystem water limitation responses at a daily resolution from an existing dataset could prove valuable, if nothing less than a benchmark to test current hypotheses. To this end, we propose two data-driven indicators derived directly from the eddy covariance data and based on expected physiological responses to hydraulic and non-stomatal limitations. Hydraulic limitations are proxied using the normalized diurnal centroid, which measures the degree to which the flux of ET is shifted toward the morning. Non-stomatal limitations are characterized by the Diurnal Water:Carbon Index (DWCI), which measures the degree of coupling between daily ET and GPP fluxes. Globally, we found significantly high frequencies of morning shifted days in dry/Mediterranean climates and savanna plant functional types (PFT), whereas high frequencies of decoupling were found in dry climates and grassland/savanna PFTs. Overall, both the diurnal centroid and DWCI were associated with high net radiation and low latent energy. Using three water use efficiency (WUE) models, we found the mean difference between expected and observed WUE to be 0.09 to -0.23 umol/mmol and -0.42 to -0.49 umol/mmol for decoupled and morning shifted days respectively, indicating an increase in WUE associated with the metrics that the models were unable to capture. Furthermore we discuss the application of diurnal centroid and DWCI to methods of evapotranspiration partitioning and estimation of ecosystem isohydricity.

  14. Impact of land convection on temperature diurnal variation in the tropical lower stratosphere inferred from COSMIC GPS radio occultations

    Directory of Open Access Journals (Sweden)

    S. M. Khaykin

    2013-07-01

    Full Text Available Following recent studies evidencing the influence of deep convection on the chemical composition and thermal structure of the tropical lower stratosphere, we explore its impact on the temperature diurnal variation in the upper troposphere and lower stratosphere using the high-resolution COSMIC GPS radio-occultation temperature measurements spanning from 2006 through 2011. The temperature in the lowermost stratosphere over land during summer displays a marked diurnal cycle characterized by an afternoon cooling. This diurnal cycle is shown collocated with most intense land convective areas observed by the Tropical Rainfall Measurement Mission (TRMM precipitation radar and in phase with the maximum overshooting occurrence frequency in late afternoon. Two processes potentially responsible for that are identified: (i non-migrating tides, whose physical nature is internal gravity waves, and (ii local cross-tropopause mass transport of adiabatically cooled air by overshooting turrets. Although both processes can contribute, only the lofting of adiabatically cooled air is well captured by models, making it difficult to characterize the contribution of non-migrating tides. The impact of deep convection on the temperature diurnal cycle is found larger in the southern tropics, suggesting more vigorous convection over clean rain forest continents than desert areas and polluted continents in the northern tropics.

  15. Distinct patterns in the diurnal and seasonal variability in four components of soil respiration in a temperate forest under free-air CO2 enrichment

    Directory of Open Access Journals (Sweden)

    M. A. Gonzalez-Meler

    2011-10-01

    Full Text Available Soil respiration (RS is a major flux in the global carbon (C cycle. Responses of RS to changing environmental conditions may exert a strong control on the residence time of C in terrestrial ecosystems and in turn influence the atmospheric concentration of greenhouse gases. Soil respiration consists of several components oxidizing soil C from different pools, age and chemistry. The mechanisms underlying the temporal variability of RS components are poorly understood. In this study, we used the long-term whole-ecosystem 13C tracer at the Duke Forest Free Air CO2 Enrichment site to separate forest RS into its autotrophic (RR and heterotrophic components (RH. The contribution of RH to RS was further partitioned into litter decomposition (RL, and decomposition of soil organic matter (RSOM of two age classes – up to 8 yr old and SOM older than 8 yr. Soil respiration was generally dominated by RSOM during the growing season (44% of daytime RS, especially at night. The contribution of heterotrophic respiration (RSOM and RL to RS was not constant, indicating that the seasonal variability in RR alone cannot explain seasonal variation in RS. Although there was no diurnal variability in RS, there were significant compensatory differences in the contribution of individual RS components to daytime and nighttime rates. The average contribution of RSOM to RS was greater at night (54% than during the day (44%. The average contribution of RR to total RS was ~30% during the day and ~34% during the night. In contrast, RL constituted 26% of RS during the day and only 12% at night. About 95% of the decomposition of soil C older than 8 yr (Rpre-tr originated from RSOM and showed more pronounced and consistent diurnal variability than any other RS component; nighttime rates were on average 29% higher than daytime rates. In contrast, the decomposition of more recent, post-treatment C (Rpre-tr did not vary diurnally. None of the diurnal variations in components of RH

  16. Ten-Year Climatology of Summertime Diurnal Rainfall Rate Over the Conterminous U.S.

    Science.gov (United States)

    Matsui, Toshihisa; Mocko, David; Lee, Myong-In; Tao, Wei-Kuo; Suarez, Max J.; Pielke, Roger A., Sr.

    2010-01-01

    Diurnal cycles of summertime rainfall rates are examined over the conterminous United States, using radar-gauge assimilated hourly rainfall data. As in earlier studies, rainfall diurnal composites show a well-defined region of rainfall propagation over the Great Plains and an afternoon maximum area over the south and eastern portion of the United States. Zonal phase speeds of rainfall in three different small domains are estimated, and rainfall propagation speeds are compared with background zonal wind speeds. Unique rainfall propagation speeds in three different regions can be explained by the evolution of latent-heat theory linked to the convective available potential energy, than by gust-front induced or gravity wave propagation mechanisms.

  17. Quasi-biennial oscillation signatures in the diurnal tidal winds over Cachoeira Paulista, Brazil

    Science.gov (United States)

    de Araújo, Luciana Rodrigues; Lima, Lourivaldo Mota; Jacobi, Christoph; Batista, Paulo Prado

    2017-03-01

    Mesosphere/lower thermosphere winds obtained by meteor radar over Cachoeira Paulista (22.7° S, 45.0° W), Brazil, have been used to investigate the interannual variability of the diurnal tidal (DT) wind amplitude. The monthly DT displays year to year variations and their amplitudes are strongest during the westerly phase of the quasi-biennial oscillation (QBO) at the 30 hPa level. This can be observed in all seasons in the meridional component, whilst in the zonal component the signal is clearer during austral autumn, when the diurnal tide is strongest in this latitude. The spectrum obtained from the deseasonalized amplitudes shows a peak near 26 months in the meridional component, which can be associated to the stratospheric QBO. The QBO modulation of the DT amplitude shows a quasi-decadal variation, and it is stronger during the maximum of the solar cycle.

  18. MLT winds and diurnal tides at southern low latitudes in the period 1999-2008

    Science.gov (United States)

    Rodrigues de Araujo, Luciana; Takahashi, Hisao; Clemesha, Barclay; Batista, Paulo; Lima, Lourivaldo

    Meteor radar measurements obtained during the time intervals from March 1999 to July 2006 and from September 2007 to October 2008, at Cachoeira Paulista (22.7° S, 45.0° W), Brazil, have been analyzed to investigate long-term trends and solar activity-induced variations in the mesosphere and lower thermosphere region (MLT) dynamics. Regression analyses with a dependence on solar activity and time have revealed a possible effect of the solar cycle upon monthly zonal and meridional wind behavior, in which solar activity may have contributed to weaken eastward winds, increase westward and meridional winds in some height ranges and time periods. Diurnal and semidiurnal tide amplitudes also have been analyzed and the results point out that the diurnal tides for solar minimum years are amplifies, whereas the amplitudes for semidiurnal tides showed an opposite behavior.

  19. Diurnal and annual variations of meteor rates at the arctic circle

    Directory of Open Access Journals (Sweden)

    W. Singer

    2004-01-01

    Full Text Available Meteors are an important source for (a the metal atoms of the upper atmosphere metal layers and (b for condensation nuclei, the existence of which are a prerequisite for the formation of noctilucent cloud particles in the polar mesopause region. For a better understanding of these phenomena, it would be helpful to know accurately the annual and diurnal variations of meteor rates. So far, these rates have been little studied at polar latitudes. Therefore we have used the 33 MHz meteor radar of the ALOMAR observatory at 69° N to measure the meteor rates at this location for two full annual cycles. This site, being within 3° of the Arctic circle, offers in addition an interesting capability: The axis of its antenna field points (almost towards the North ecliptic pole once each day of the year. In this particular viewing direction, the radar monitors the meteoroid influx from (almost the entire ecliptic Northern hemisphere. We report on the observed diurnal variations (averaged over one month of meteor rates and their significant alterations throughout the year. The ratio of maximum over minimum meteor rates throughout one diurnal cycle is in January and February about 5, from April through December 2.3±0.3. If compared with similar measurements at mid-latitudes, our expectation, that the amplitude of the diurnal variation is to decrease towards the North pole, is not really borne out. Observations with the antenna axis pointing towards the North ecliptic pole showed that the rate of deposition of meteoric dust is substantially larger during the Arctic NLC season than the annual mean deposition rate. The daylight meteor showers of the Arietids, Zeta Perseids, and Beta Taurids supposedly contribute considerably to the June maximum of meteor rates. We note, though, that with the radar antenna pointing as described above, all three meteor radiants are close to the local horizon but all three radiants were detected.

  20. Diurnal and seasonal occurrence of polar patches

    Directory of Open Access Journals (Sweden)

    A. S. Rodger

    1996-05-01

    Full Text Available Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon, not local noon. There are minima in occurrence near midsummer and midwinter, with maxima in occurrence between equinox and winter. There are no significant correlations between the occurrence of polar patches and the corresponding hourly averages of the solar wind and IMF parameters, except that patches usually occur when the interplanetary magnetic field has a southward component. The results can be understood in terms of UT and seasonal differences in the plasma concentration being convected from the dayside ionosphere into the polar cap. In summer and winter the electron concentrations in the polar cap are high and low, respectively, but relatively unstructured. About equinox, a tongue of enhanced ionisation is convected into the polar cap; this tongue is then structured by the effects of the interplanetary magnetic field, but these Halley data cannot be used to separate the various competing mechanisms for patch formation. The observed diurnal and seasonal variation in the occurrence of polar patches are largely consistent with predictions of Sojka et al. (1994 when their results are translated into the southern hemisphere. However, the ionospheric effects of flux transfer events are still considered essential in their formation, a feature not yet included in the Sojka et al. model.

  1. Deregulated power prices: comparison of diurnal patterns

    International Nuclear Information System (INIS)

    Li Ying; Flynn, Peter C.

    2004-01-01

    We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms

  2. Deregulated power prices: comparison of diurnal patterns

    International Nuclear Information System (INIS)

    Ying Li; Flynn, P.C.

    2004-01-01

    We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms. (Author)

  3. Practical limitations on the use of diurnal temperature signals to quantify groundwater upwelling

    Science.gov (United States)

    Briggs, Martin A.; Lautz, Laura K.; Buckley, Sean F.; Lane, John W.

    2014-01-01

    Groundwater upwelling to streams creates unique habitat by influencing stream water quality and temperature; upwelling zones also serve as vectors for contamination when groundwater is degraded. Temperature time series data acquired along vertical profiles in the streambed have been applied to simple analytical models to determine rates of vertical fluid flux. These models are based on the downward propagation characteristics (amplitude attenuation and phase-lag) of the surface diurnal signal. Despite the popularity of these models, there are few published characterizations of moderate-to-strong upwelling. We attribute this limitation to the thermodynamics of upwelling, under which the downward conductive signal transport from the streambed interface occurs opposite the upward advective fluid flux. Governing equations describing the advection–diffusion of heat within the streambed predict that under upwelling conditions, signal amplitude attenuation will increase, but, counterintuitively, phase-lag will decrease. Therefore the extinction (measurable) depth of the diurnal signal is very shallow, but phase lag is also short, yielding low signal to noise ratio and poor model sensitivity. Conversely, amplitude attenuation over similar sensor spacing is strong, yielding greater potential model sensitivity. Here we present streambed thermal time series over a range of moderate to strong upwelling sites in the Quashnet River, Cape Cod, Massachusetts. The predicted inverse relationship between phase-lag and rate of upwelling was observed in the field data over a range of conditions, but the observed phase-lags were consistently shorter than predicted. Analytical solutions for fluid flux based on signal amplitude attenuation return results consistent with numerical models and physical seepage meters, but the phase-lag analytical model results are generally unreasonable. Through numerical modeling we explore reasons why phase-lag may have been over-predicted by the

  4. Ciclo diário da precipitação estimada através de um radar banda S e pelo algoritmo 3B42_V6 do projeto TRMM durante a estação chuvosa de 1999 no sudoeste da Amazônia Diurnal cycle of the precipitation estimated by a S-band radar, and the 3B42_V6 algorithm of the TRMM project during the rainy season of 1999 over southwestern of the Amazon

    Directory of Open Access Journals (Sweden)

    Cláudio Moisés Santos e Silva

    2011-03-01

    Full Text Available Neste artigo apresenta-se uma avaliação da precipitação estimada através do radar S-POL (banda S e pelo algoritmo 3B42_V6 do satélite TRMM, durante o experimento do período chuvoso de 1999 do projeto TRMM-LBA na Bacia Amazônica, enfocando-se a variabilidade diária. Para tal, utilizam-se técnicas estatísticas baseadas em tabela de contingência e índices, bem como a análise harmônica. Demonstra-se que precipitação determinada com o radar é coerente com as observações de rede de pluviômetros. O ciclo diário exibe um máximo principal no final da tarde, e um pico secundário à noite, que é associado à propagação de Linhas de Instabilidades no interior da Bacia Amazônica. O algoritmo 3B42_V6 reproduz características importantes do ciclo diário de precipitação: (i o máximo intenso às 2100 UTC (1700 HL; (ii precipitação noturna mais intensa durante o regime de Oeste. Uma importante aplicação deste estudo é o uso dos resultados para avaliação de modelos numéricos de simulação do tempo e do clima, principalmente no que concerne à representação da convecção sobre a região.The rainfall estimated with a S-band radar, and by the 3B42_V6 TRMM satellite algorithm, is evaluated by comparing it with rain gauge measurements during the 1999 rainy season in the Amazon Basin, with focus on the diurnal cycle. Statistic analyses based on contingency tables, skill scores, and harmonic analysis were used. The radar estimation is in agreement with the rain gauges measurements. The diurnal cycle exhibits a main maximum during the afternoon and a secondary one at night, which is associated to Squall Lines propagation over the Amazon Basin. It is also shown that the 3B42_V6 algorithm captured important features of the rainfall diurnal cycle: (i the maximum at 2100 UTC (1700 LST; (ii the nocturnal rainfall is strongest during Westerly regimes. These results are important for numerical weather and climate prediction model

  5. Winter habitat associations of diurnal raptors in Californias Central Valley

    Science.gov (United States)

    Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

    2011-01-01

    The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

  6. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Directory of Open Access Journals (Sweden)

    G. Duma

    2003-01-01

    Full Text Available Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998. This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999. In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989, where a giant artificial current loop was activated in the Barents Sea.

  7. Diurnal variation and evaluation of physico-chemical properties of ...

    African Journals Online (AJOL)

    This study was carried out to evaluate the magnitude of diurnal variation of physicochemical parameters and potability of the Ikpoba River. Water samples were taken from stations 1 and 2 within the Reservoir and station 3 downstream. Water quality parameters showed significant diurnal, seasonal and spatial variations.

  8. Characteristics of diurnal pattern of global photosynthetically-active ...

    African Journals Online (AJOL)

    A two year data (September 1992 August 1994) on photosynhetically-active radiation (PAR) measured at Ilorin (Lat.: 832´N. Long.:434´E) using LI-190SA quantum sensor are analysed both on daily and monthly mean diurnal bases. This was done with the aim of characterizing the diurnal pattern of this radiation at this ...

  9. Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR

    Directory of Open Access Journals (Sweden)

    J. Fiedler

    2005-06-01

    Full Text Available From 1997 to 2003, noctilucent clouds (NLC were observed by lidar above the ALOMAR observatory in Northern Norway (69° N during a total of 1880 measurement hours. This data set contains NLC signatures for 640h, covering all local times, even during the highest solar background conditions. After data limitation imposing a threshold value of 4x10-10m-1sr-1 for the volume backscatter coefficient of the NLC particles, a measure for the cloud brightness, local time dependencies of the NLC occurrence frequency, altitude, and brightness were determined. On average, over the 7 years NLC occurred during the whole day and preferably in the early morning hours, with a maximum occurrence frequency of ~40% between 4 and 7 LT. Splitting the data into weak and strong clouds yields almost identical amplitudes of diurnal and semidiurnal variations for the occurrence of weak clouds, whereas the strong clouds are dominated by the diurnal variation. NLC occurrence, altitude, as well as brightness, show a remarkable persistence concerning diurnal and semidiurnal variations from 1997 to 2003, suggesting that NLC above ALOMAR are significantly controlled by atmospheric tides. The observed mean anti-phase behavior between cloud altitude and brightness is attributed to a phase shift between the semidiurnal components by ~6h. Investigation of data for each individual year regarding the prevailing oscillation periods of the NLC parameters showed different phase relationships, leading to a complex variability in the cloud parameters.

  10. Seasonal and diurnal variability of N{sub 2}O emissions from a full-scale municipal wastewater treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Daelman, Matthijs R.J., E-mail: m.r.j.daelman@tudelft.nl [Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft (Netherlands); Department of Biosystems engineering, Ghent University, Coupure links 653, 9000 Gent (Belgium); Voorthuizen, Ellen M. van [Royal HaskoningDHV, P.O. Box 151, 6500AD Nijmegen (Netherlands); Dongen, Udo G.J.M. van [Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft (Netherlands); Volcke, Eveline I.P. [Department of Biosystems engineering, Ghent University, Coupure links 653, 9000 Gent (Belgium); Loosdrecht, Mark C.M. van [Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft (Netherlands)

    2015-12-01

    During nitrogen removal in conventional activated sludge processes, nitrous oxide can be emitted. With a global warming potential of 298 CO{sub 2}-equivalents it is an important greenhouse gas that affects the sustainability of wastewater treatment. The present study reports nitrous oxide emission data from a 16 month monitoring campaign on a full-scale municipal wastewater treatment. The emission demonstrated a pronounced diurnal and seasonal variability. This variability was compared with the variability of a number of process variables that are commonly available on a municipal wastewater treatment plant. On a seasonal timescale, the occurrence of peaks in the nitrite concentration correlated strongly with the emission. The diurnal trend of the emission coincided with the diurnal trend of the nitrite and nitrate concentrations in the tank, suggesting that suboptimal oxygen concentrations may induce the production of nitrous oxide during both nitrification and denitrification. This study documents an unprecedented dataset that could serve as a reference for further research. - Highlights: • Unique dataset of long-term nitrous oxide emission from activated sludge tanks • Emission exhibited pronounced diurnal variability, superimposed on seasonal trend • Seasonal nitrous oxide emission trend correlated with daily nitrite peaks • Emission’s diurnal trend suggests suboptimal oxygen concentrations as cause.

  11. Diurnal variation of aldosterone and plasma renin activity: timing relation to melatonin and cortisol and consistency after prolonged bed rest.

    Science.gov (United States)

    Hurwitz, Shelley; Cohen, Richard J; Williams, Gordon H

    2004-04-01

    Exposure to prolonged bed rest is known to induce changes in the renin-angiotensin-aldosterone system (RAAS) by way of posture, sodium and potassium balance, and stress, which may have serious consequences for patients. We focused on the diurnal variation of the RAAS by investigating changes in the levels of plasma renin activity (PRA) and aldosterone; for comparison to markers of the intrinsic pacemaker and to stress, we measured melatonin and cortisol. PRA, aldosterone, melatonin, and cortisol were measured hourly in 10 normal subjects with standardized sleep patterns, posture, and diet at baseline and after 11 days of prolonged bed rest conducted under a light-dark cycle. Circadian characteristics of hormone secretion patterns were estimated by multiple harmonic regression with excellent goodness-of-fit measures. Variability in the melatonin and cortisol patterns across subjects was minimal. Even for pulsatile hormones, this technique successfully estimated the acrophase, which was the salient feature. Baseline hormone peak times started with melatonin near the middle of the sleep period, followed by PRA, then aldosterone, and then cortisol around wake time. Prolonged bed rest did not induce significant changes in any timing characteristic of the secretion patterns. Baseline and prolonged bed rest peak times for melatonin and cortisol and amplitude characteristics for all hormones were highly correlated, indicating consistency within individuals. These data provide strong evidence that prolonged bed rest of 11 days' duration does not disrupt either the timing characteristics of the RAAS or the intrinsic pacemaker.

  12. Tissue specific diurnal rhythms of metabolites and their regulation during herbivore attack in a native tobacco, Nicotiana attenuata.

    Directory of Open Access Journals (Sweden)

    Sang-Gyu Kim

    Full Text Available Ecological performance is all about timing and the endogenous clock that allows the entrainment of rhythms and anticipation of fitness-determining events is being rapidly characterized. How plants anticipate daily abiotic stresses, such as cold in early mornings and drought at noon, as well as biotic stresses, such as the timing of pathogen infections, is being explored, but little is known about the clock's role in regulating responses to insect herbivores and mutualists, whose behaviors are known to be strongly diurnally regulated and whose attack is known to reconfigure plant metabolomes. We developed a liquid chromatography-mass spectrometry procedure and analyzed its output with model-based peak picking algorithms to identify metabolites with diurnal accumulation patterns in sink/source leaves and roots in an unbiased manner. The response of metabolites with strong diurnal patterns to simulated attack from the specialist herbivore, Manduca sexta larvae was analyzed and annotated with in-house and public databases. Roots and leaves had largely different rhythms and only 10 ions of 182 oscillating ions in leaves and 179 oscillating ions in roots were rhythmic in both tissues: root metabolites mainly peaked at dusk or night, while leaf metabolites peaked during the day. Many oscillating metabolites showed tissue-specific regulation by simulated herbivory of which systemic responses in unattacked tissues were particularly pronounced. Diurnal and herbivory-elicited accumulation patterns of disaccharide, phenylalanine, tyrosine, lyciumoside I, coumaroyl tyramine, 12-oxophytodienoic acid and jasmonic acid and those of their related biosynthetic transcripts were examined in detail. We conclude that oscillating metabolites of N. attenuata accumulate in a highly tissue-specific manner and the patterns reveal pronounced diurnal rhythms in the generalized and specialized metabolism that mediates the plant's responses to herbivores and mutualists. We

  13. Simulation of diurnal thermal energy storage systems: Preliminary results

    Science.gov (United States)

    Katipamula, S.; Somasundaram, S.; Williams, H. R.

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system; and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  14. Diurnal and semi-diurnal tidal structures due to O2, O3 and H2O ...

    Indian Academy of Sciences (India)

    from World Meteorological Organization (WMO. 1986), while the Rayleigh scattering cross section was calculated using the formula of Nicolet (1984). ..... Figure 5(a) exhibits the exponential growth of diurnal amplitude with altitude, at low to mid lat- itudes. At high latitudes, the diurnal amplitude decreases with altitude due to ...

  15. Diurnal warming in shallow coastal seas: Observations from the Caribbean and Great Barrier Reef regions

    Science.gov (United States)

    Zhu, X.; Minnett, P. J.; Berkelmans, R.; Hendee, J.; Manfrino, C.

    2014-07-01

    A good understanding of diurnal warming in the upper ocean is important for the validation of satellite-derived sea surface temperature (SST) against in-situ buoy data and for merging satellite SSTs taken at different times of the same day. For shallow coastal regions, better understanding of diurnal heating could also help improve monitoring and prediction of ecosystem health, such as coral reef bleaching. Compared to its open ocean counterpart which has been studied extensively and modeled with good success, coastal diurnal warming has complicating localized characteristics, including coastline geometry, bathymetry, water types, tidal and wave mixing. Our goal is to characterize coastal diurnal warming using two extensive in-situ temperature and weather datasets from the Caribbean and Great Barrier Reef (GBR), Australia. Results showed clear daily warming patterns in most stations from both datasets. For the three Caribbean stations where solar radiation is the main cause of daily warming, the mean diurnal warming amplitudes were about 0.4 K at depths of 4-7 m and 0.6-0.7 K at shallower depths of 1-2 m; the largest warming value was 2.1 K. For coral top temperatures of the GBR, 20% of days had warming amplitudes >1 K, with the largest >4 K. The bottom warming at shallower sites has higher daily maximum temperatures and lower daily minimum temperatures than deeper sites nearby. The averaged daily warming amplitudes were shown to be closely related to daily average wind speed and maximum insolation, as found in the open ocean. Diurnal heating also depends on local features including water depth, location on different sections of the reef (reef flat vs. reef slope), the relative distance from the barrier reef chain (coast vs. lagoon stations vs. inner barrier reef sites vs. outer rim sites); and the proximity to the tidal inlets. In addition, the influence of tides on daily temperature changes and its relative importance compared to solar radiation was quantified by

  16. Diurnal Rhythms Result in Significant Changes in the Cellular Protein Complement in the Cyanobacterium Cyanothece 51142

    Energy Technology Data Exchange (ETDEWEB)

    Stockel, Jana; Jacobs, Jon M.; Elvitigala, Thanura R.; Liberton, Michelle L.; Welsh, Eric A.; Polpitiya, Ashoka D.; Gritsenko, Marina A.; Nicora, Carrie D.; Koppenaal, David W.; Smith, Richard D.; Pakrasi, Himadri B.

    2011-02-22

    Cyanothece sp. ATCC 51142 is a diazotrophic cyanobacterium notable for its ability to perform oxygenic photosynthesis and dinitrogen fixation in the same single cell. Previous transcriptional analysis revealed that the existence of these incompatible cellular processes largely depends on tightly synchronized expression programs involving ,30% of genes in the genome. To expand upon current knowledge, we have utilized sensitive proteomic approaches to examine the impact of diurnal rhythms on the protein complement in Cyanothece 51142. We found that 250 proteins accounting for,5% of the predicted ORFs from the Cyanothece 51142 genome and 20% of proteins detected under alternating light/dark conditions exhibited periodic oscillations in their abundances. Our results suggest that altered enzyme activities at different phases during the diurnal cycle can be attributed to changes in the abundance of related proteins and key compounds. The integration of global proteomics and transcriptomic data further revealed that post-transcriptional events are important for temporal regulation of processes such as photosynthesis in Cyanothece 51142. This analysis is the first comprehensive report on global quantitative proteomics in a unicellular diazotrophic cyanobacterium and uncovers novel findings about diurnal rhythms.

  17. Diurnal Transcriptome and Gene Network Represented through Sparse Modeling in Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Satoru Koda

    2017-11-01

    Full Text Available We report the comprehensive identification of periodic genes and their network inference, based on a gene co-expression analysis and an Auto-Regressive eXogenous (ARX model with a group smoothly clipped absolute deviation (SCAD method using a time-series transcriptome dataset in a model grass, Brachypodium distachyon. To reveal the diurnal changes in the transcriptome in B. distachyon, we performed RNA-seq analysis of its leaves sampled through a diurnal cycle of over 48 h at 4 h intervals using three biological replications, and identified 3,621 periodic genes through our wavelet analysis. The expression data are feasible to infer network sparsity based on ARX models. We found that genes involved in biological processes such as transcriptional regulation, protein degradation, and post-transcriptional modification and photosynthesis are significantly enriched in the periodic genes, suggesting that these processes might be regulated by circadian rhythm in B. distachyon. On the basis of the time-series expression patterns of the periodic genes, we constructed a chronological gene co-expression network and identified putative transcription factors encoding genes that might be involved in the time-specific regulatory transcriptional network. Moreover, we inferred a transcriptional network composed of the periodic genes in B. distachyon, aiming to identify genes associated with other genes through variable selection by grouping time points for each gene. Based on the ARX model with the group SCAD regularization using our time-series expression datasets of the periodic genes, we constructed gene networks and found that the networks represent typical scale-free structure. Our findings demonstrate that the diurnal changes in the transcriptome in B. distachyon leaves have a sparse network structure, demonstrating the spatiotemporal gene regulatory network over the cyclic phase transitions in B. distachyon diurnal growth.

  18. Diurnal Transcriptome and Gene Network Represented through Sparse Modeling inBrachypodium distachyon.

    Science.gov (United States)

    Koda, Satoru; Onda, Yoshihiko; Matsui, Hidetoshi; Takahagi, Kotaro; Yamaguchi-Uehara, Yukiko; Shimizu, Minami; Inoue, Komaki; Yoshida, Takuhiro; Sakurai, Tetsuya; Honda, Hiroshi; Eguchi, Shinto; Nishii, Ryuei; Mochida, Keiichi

    2017-01-01

    We report the comprehensive identification of periodic genes and their network inference, based on a gene co-expression analysis and an Auto-Regressive eXogenous (ARX) model with a group smoothly clipped absolute deviation (SCAD) method using a time-series transcriptome dataset in a model grass, Brachypodium distachyon . To reveal the diurnal changes in the transcriptome in B. distachyon , we performed RNA-seq analysis of its leaves sampled through a diurnal cycle of over 48 h at 4 h intervals using three biological replications, and identified 3,621 periodic genes through our wavelet analysis. The expression data are feasible to infer network sparsity based on ARX models. We found that genes involved in biological processes such as transcriptional regulation, protein degradation, and post-transcriptional modification and photosynthesis are significantly enriched in the periodic genes, suggesting that these processes might be regulated by circadian rhythm in B. distachyon . On the basis of the time-series expression patterns of the periodic genes, we constructed a chronological gene co-expression network and identified putative transcription factors encoding genes that might be involved in the time-specific regulatory transcriptional network. Moreover, we inferred a transcriptional network composed of the periodic genes in B. distachyon , aiming to identify genes associated with other genes through variable selection by grouping time points for each gene. Based on the ARX model with the group SCAD regularization using our time-series expression datasets of the periodic genes, we constructed gene networks and found that the networks represent typical scale-free structure. Our findings demonstrate that the diurnal changes in the transcriptome in B. distachyon leaves have a sparse network structure, demonstrating the spatiotemporal gene regulatory network over the cyclic phase transitions in B. distachyon diurnal growth.

  19. Assessing the sources and magnitude of diurnal nitrate variability in the San Joaquin River (California) with an in situ optical nitrate sensor and dual nitrate isotopes

    Science.gov (United States)

    Pellerin, B.A.; Downing, B.D.; Kendall, C.; Dahlgren, R.A.; Kraus, T.E.C.; Saraceno, J.; Spencer, R.G.M.; Bergamaschi, B.A.

    2009-01-01

    1. We investigated diurnal nitrate (NO3-) concentration variability in the San Joaquin River using an in situ optical NO3- sensor and discrete sampling during a 5-day summer period characterized by high algal productivity. Dual NO3- isotopes (??15NNO3 and ??18O NO3) and dissolved oxygen isotopes (??18O DO) were measured over 2 days to assess NO3- sources and biogeochemical controls over diurnal time-scales. 2. Concerted temporal patterns of dissolved oxygen (DO) concentrations and ??18ODO were consistent with photosynthesis, respiration and atmospheric O2 exchange, providing evidence of diurnal biological processes independent of river discharge. 3. Surface water NO3- concentrations varied by up to 22% over a single diurnal cycle and up to 31% over the 5-day study, but did not reveal concerted diurnal patterns at a frequency comparable to DO concentrations. The decoupling of ??15NNO3 and ??18ONO3 isotopes suggests that algal assimilation and denitrification are not major processes controlling diurnal NO3- variability in the San Joaquin River during the study. The lack of a clear explanation for NO 3- variability likely reflects a combination of riverine biological processes and time-varying physical transport of NO3- from upstream agricultural drains to the mainstem San Joaquin River. 4. The application of an in situ optical NO3- sensor along with discrete samples provides a view into the fine temporal structure of hydrochemical data and may allow for greater accuracy in pollution assessment. ?? 2008 Blackwell Publishing Ltd.

  20. MicroRNA mir-16 is anti-proliferative in enterocytes and exhibits diurnal rhythmicity in intestinal crypts

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Anita, E-mail: anita.balakrishnan@doctors.org.uk [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); School of Clinical Sciences, Division of Gastroenterology, University of Liverpool, Liverpool L69 3GE (United Kingdom); Stearns, Adam T. [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 2JD (United Kingdom); Park, Peter J. [Department of Medicine, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Harvard Medical School, Center for Biomedical Informatics, Boston, MA 02115 (United States); Dreyfuss, Jonathan M. [Department of Medicine, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Ashley, Stanley W. [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Rhoads, David B. [Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States); Pediatric Endocrine Unit, MassGeneral Hospital for Children, Boston, MA 02114 (United States); Tavakkolizadeh, Ali, E-mail: atavakkoli@partners.org [Department of Surgery, Brigham and Women' s Hospital, Boston, MA 02115 (United States); Department of Surgery, Harvard Medical School, Boston, MA 02115 (United States)

    2010-12-10

    Background and aims: The intestine exhibits profound diurnal rhythms in function and morphology, in part due to changes in enterocyte proliferation. The regulatory mechanisms behind these rhythms remain largely unknown. We hypothesized that microRNAs are involved in mediating these rhythms, and studied the role of microRNAs specifically in modulating intestinal proliferation. Methods: Diurnal rhythmicity of microRNAs in rat jejunum was analyzed by microarrays and validated by qPCR. Temporal expression of diurnally rhythmic mir-16 was further quantified in intestinal crypts, villi, and smooth muscle using laser capture microdissection and qPCR. Morphological changes in rat jejunum were assessed by histology and proliferation by immunostaining for bromodeoxyuridine. In IEC-6 cells stably overexpressing mir-16, proliferation was assessed by cell counting and MTS assay, cell cycle progression and apoptosis by flow cytometry, and cell cycle gene expression by qPCR and immunoblotting. Results: mir-16 peaked 6 hours after light onset (HALO 6) with diurnal changes restricted to crypts. Crypt depth and villus height peaked at HALO 13-14 in antiphase to mir-16. Overexpression of mir-16 in IEC-6 cells suppressed specific G1/S regulators (cyclins D1-3, cyclin E1 and cyclin-dependent kinase 6) and produced G1 arrest. Protein expression of these genes exhibited diurnal rhythmicity in rat jejunum, peaking between HALO 11 and 17 in antiphase to mir-16. Conclusions: This is the first report of circadian rhythmicity of specific microRNAs in rat jejunum. Our data provide a link between anti-proliferative mir-16 and the intestinal proliferation rhythm and point to mir-16 as an important regulator of proliferation in jejunal crypts. This function may be essential to match proliferation and absorptive capacity with nutrient availability.

  1. MicroRNA mir-16 is anti-proliferative in enterocytes and exhibits diurnal rhythmicity in intestinal crypts

    International Nuclear Information System (INIS)

    Balakrishnan, Anita; Stearns, Adam T.; Park, Peter J.; Dreyfuss, Jonathan M.; Ashley, Stanley W.; Rhoads, David B.; Tavakkolizadeh, Ali

    2010-01-01

    Background and aims: The intestine exhibits profound diurnal rhythms in function and morphology, in part due to changes in enterocyte proliferation. The regulatory mechanisms behind these rhythms remain largely unknown. We hypothesized that microRNAs are involved in mediating these rhythms, and studied the role of microRNAs specifically in modulating intestinal proliferation. Methods: Diurnal rhythmicity of microRNAs in rat jejunum was analyzed by microarrays and validated by qPCR. Temporal expression of diurnally rhythmic mir-16 was further quantified in intestinal crypts, villi, and smooth muscle using laser capture microdissection and qPCR. Morphological changes in rat jejunum were assessed by histology and proliferation by immunostaining for bromodeoxyuridine. In IEC-6 cells stably overexpressing mir-16, proliferation was assessed by cell counting and MTS assay, cell cycle progression and apoptosis by flow cytometry, and cell cycle gene expression by qPCR and immunoblotting. Results: mir-16 peaked 6 hours after light onset (HALO 6) with diurnal changes restricted to crypts. Crypt depth and villus height peaked at HALO 13-14 in antiphase to mir-16. Overexpression of mir-16 in IEC-6 cells suppressed specific G1/S regulators (cyclins D1-3, cyclin E1 and cyclin-dependent kinase 6) and produced G1 arrest. Protein expression of these genes exhibited diurnal rhythmicity in rat jejunum, peaking between HALO 11 and 17 in antiphase to mir-16. Conclusions: This is the first report of circadian rhythmicity of specific microRNAs in rat jejunum. Our data provide a link between anti-proliferative mir-16 and the intestinal proliferation rhythm and point to mir-16 as an important regulator of proliferation in jejunal crypts. This function may be essential to match proliferation and absorptive capacity with nutrient availability.

  2. Diurnal flight behavior of Ichneumonoidea (Insecta: Hymenoptera) related to environmental factors in a tropical dry forest.

    Science.gov (United States)

    González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H

    2012-06-01

    The biology and behavior of insects are strongly influenced by environmental conditions such as temperature and precipitation. Because some of these factors present a within day variation, they may be causing variations on insect diurnal flight activity, but scant information exists on the issue. The aim of this work was to describe the patterns on diurnal variation of the abundance of Ichneumonoidea and their relation with relative humidity, temperature, light intensity, and wind speed. The study site was a tropical dry forest at Ría Lagartos Biosphere Reserve, Mexico; where correlations between environmental factors (relative humidity, temperature, light, and wind speed) and abundance of Ichneumonidae and Braconidae (Hymenoptera: Ichneumonoidea) were estimated. The best regression model for explaining abundance variation was selected using the second order Akaike Information Criterion. The optimum values of temperature, humidity, and light for flight activity of both families were also estimated. Ichneumonid and braconid abundances were significantly correlated to relative humidity, temperature, and light intensity; ichneumonid also showed significant correlations to wind speed. The second order Akaike Information Criterion suggests that in tropical dry conditions, relative humidity is more important that temperature for Ichneumonoidea diurnal activity. Ichneumonid wasps selected toward intermediate values of relative humidity, temperature and the lowest wind speeds; while Braconidae selected for low values of relative humidity. For light intensity, braconids presented a positive selection for moderately high values.

  3. Tracking diurnal changes of photosynthesis and evapotranspiration using fluorescence, gas exchange and hyperspectral remote sensing measurements

    Science.gov (United States)

    Wang, S.; Zhang, L.; Guanter, L.; Huang, C.

    2017-12-01

    Photosynthesis and evapotranspiration (ET) are the two most important activities of vegetation and make a great contribution to carbon, water and energy exchanges. Remote sensing provides opportunities for monitoring these processes across time and space. This study focuses on tracking diurnal changes of photosynthesis and evapotranspiration over soybean using multiple measurement techniques. Diurnal changes of both remote sensing-based indicators, including active and passive chlorophyll fluorescence and biophysical-related parameters, including photosynthesis rate (photo) and leaf stomatal conductance (cond), were observed. Results showed that both leaf-level steady-state fluorescence (Fs) and canopy-level solar-induced chlorophyll fluorescence were linearly correlated to photosynthetically active radiation (PAR) during the daytime. A double-peak diurnal change curve was observed for leaf-level photo and cond but not for Fs or SIF. Photo and cond showed a strong nonlinear (second-order) correlation, indicating that photosynthesis, which might be remotely sensed by SIF, has the opportunity to track short-term changes of ET. Results presented in this report will be helpful for better understanding the relationship between remote-sensing-based indices and vegetation's biophysical processes.

  4. Diurnal cortisol rhythms in Tsimane' Amazonian foragers: new insights into ecological HPA axis research.

    Science.gov (United States)

    Nyberg, Colleen H

    2012-02-01

    Although a growing body of research has documented important pathways by which the HPA axis mediates the interface between the psychosocial world and individual health, there is a paucity of data from nonwestern populations, particularly from those populations with distinct nutritional and infectious disease ecologies. The specific objectives of this study are: (1) to document variation in diurnal cortisol rhythms among the Tsimane', a remote population in the Bolivian Amazon, (2) to explore this variation by age and by gender, and (3) to compare diurnal rhythms from this study to other population based studies of cortisol conducted in industrialized nations. Salivary cortisol samples were collected twice daily, immediately upon waking and before bed, for three consecutive days from 303 participants (age 1.6-82 years, 1564 samples) in conjunction with the Tsimane' Amazonian Panel Study (TAPS). Cortisol rhythms showed strong age effects across the developmental span, with basal levels and slopes increasing into adulthood, although individuals older than 60 years demonstrated a precipitous flattening of the diurnal slope. Cortisol profiles were elevated in adult females compared to their age-matched male counterparts, and diurnal slopes, as well as mean cortisol concentrations among the Tsimane' were the lowest reported in any population based study of HPA axis function. Although the within-population variation in cortisol profiles was consistent with the established correlates of time of day, age, and sex, the between-population comparisons revealed dramatically lower levels of HPA activity among the Tsimane'. This study provides a benchmark against which to reference cortisol levels from industrialized populations, and expands the range of documented variation in HPA axis function in a nonwestern context. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Sleep Deprivation and Caffeine Treatment Potentiate Photic Resetting of the Master Circadian Clock in a Diurnal Rodent.

    Science.gov (United States)

    Jha, Pawan Kumar; Bouâouda, Hanan; Gourmelen, Sylviane; Dumont, Stephanie; Fuchs, Fanny; Goumon, Yannick; Bourgin, Patrice; Kalsbeek, Andries; Challet, Etienne

    2017-04-19

    Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light/dark cycle. However, nonphotic factors, such as behavioral arousal and metabolic cues, can also phase shift the master clock in the suprachiasmatic nuclei (SCNs) and/or reduce the synchronizing effects of light in nocturnal rodents. In diurnal rodents, the role of arousal or insufficient sleep in these functions is still poorly understood. In the present study, diurnal Sudanian grass rats, Arvicanthis ansorgei , were aroused at night by sleep deprivation (gentle handling) or caffeine treatment that both prevented sleep. Phase shifts of locomotor activity were analyzed in grass rats transferred from a light/dark cycle to constant darkness and aroused in early night or late night. Early night, but not late night, sleep deprivation induced a significant phase shift. Caffeine on its own induced no phase shifts. Both sleep deprivation and caffeine treatment potentiated light-induced phase delays and phase advances in response to a 30 min light pulse, respectively. Sleep deprivation in early night, but not late night, potentiated light-induced c-Fos expression in the ventral SCN. Caffeine treatment in midnight triggered c-Fos expression in dorsal SCN. Both sleep deprivation and caffeine treatment potentiated light-induced c-Fos expression in calbindin-containing cells of the ventral SCN in early and late night. These findings indicate that, in contrast to nocturnal rodents, behavioral arousal induced either by sleep deprivation or caffeine during the sleeping period potentiates light resetting of the master circadian clock in diurnal rodents, and activation of calbindin-containing suprachiasmatic cells may be involved in this effect. SIGNIFICANCE STATEMENT Arousing stimuli have the ability to regulate circadian rhythms in mammals. Behavioral arousal in the sleeping period phase shifts the master clock in the suprachiasmatic nuclei and/or slows down the photic

  6. Diurnal depression in leaf hydraulic conductance at ambient and elevated [CO2] reveals anisohydric water management in field-grown soybean

    Science.gov (United States)

    Diurnal cycles of photosynthesis and water use in field-grown soybean (Glycine max) are tied to light intensity and vapor pressure deficit (VPD). At high mid-day VPD, transpiration rates can lead to a decline in leaf water potential if leaf hydraulic conductance is insufficient to supply water to in...

  7. Diurnal depression in leaf hydraulic conductance at ambient and elevated [CO2] and reveals anisohydric water management in field-grown soybean

    Science.gov (United States)

    Diurnal cycles of photosynthesis and water use in field-grown soybean (Glycine max) are tied to light intensity and vapor pressure deficit (VPD). At high mid-day VPD, transpiration rates can lead to a decline in leaf water potential ('leaf) if leaf hydraulic conductance (Kleaf) is insufficient to su...

  8. Oculomotor Assessment of Diurnal Arousal Variations

    Science.gov (United States)

    Mulligan, Jeffrey B.; Diaz-Piedra, Carolina; Di Stasi, Leandro L.

    2017-01-01

    Saccadic and pupillary responses are reliable indices of arousal decrement (e.g. fatigue), that might be exploited to improve work schedule guidelines. In this study, we tested the sensitivity of a short 30-s oculomotor test to detect diurnal arousal variations. Twelve participants (5 females, 7 males, 37.7+-11.9 years) volunteered to be assessed every hour (66+-20 min) for three consecutive working days, during their regular office-hours. We used a fully automated testing system, the FIT 2000 Fitness Impairment Tester (Pulse Medical Instruments Inc., Rockville, MD, USA), to measure and record saccadic peak velocity, pupil diameter, and latency and amplitude of the pupillary light reflex. In addition, we collected subjective levels of arousal using the Stanford Sleepiness Scale, and body core temperature. We analyzed the data using a linear mixed model approach for longitudinal data. Both saccadic velocity and subjective alertness decreased over the course of a day, while body core temperature increased (all p-values.05). The data also weakly suggested an increase of the pupil diameter (p 07). The findings support the use of oculomotor indices in the assessment of arousal and fatigue in applied settings.

  9. Bats as prey of diurnal birds: a global perspective.

    Czech Academy of Sciences Publication Activity Database

    Mikula, P.; Morelli, Federico; Lučan, R. K.; Jones, D. N.; Tryjanowski, P.

    2016-01-01

    Roč. 46, č. 3 (2016), s. 160-174 ISSN 0305-1838 Institutional support: RVO:60077344 Keywords : avian predation hypothesis * bats * diurnal birds * nocturnality * predation Subject RIV: EG - Zoology Impact factor: 3.286, year: 2016

  10. Biophysical information in asymmetric and symmetric diurnal bidirectional canopy reflectance

    Science.gov (United States)

    Vanderbilt, Vern C.; Caldwell, William F.; Pettigrew, Rita E.; Ustin, Susan L.; Martens, Scott N.; Rousseau, Robert A.; Berger, Kevin M.; Ganapol, B. D.; Kasischke, Eric S.; Clark, Jenny A.

    1991-01-01

    The authors present a theory for partitioning the information content in diurnal bidirectional reflectance measurements in order to detect differences potentially related to biophysical variables. The theory, which divides the canopy reflectance into asymmetric and symmetric functions of solar azimuth angle, attributes asymmetric variation to diurnal changes in the canopy biphysical properties. The symmetric function is attributed to the effects of sunlight interacting with a hypothetical average canopy which would display the average diurnal properties of the actual canopy. The authors analyzed radiometer data collected diurnally in the Thematic Mapper wavelength bands from two walnut canopies that received differing irrigation treatments. The reflectance of the canopies varied with sun and view angles and across seven bands in the visible, near-infrared, and middle infrared wavelength regions. Although one of the canopies was permanently water stressed and the other was stressed in mid-afternoon each day, no water stress signature was unambiguously evident in the reflectance data.

  11. Elemental and organic carbon in the urban environment of Athens. Seasonal and diurnal variations and estimates of secondary organic carbon.

    Science.gov (United States)

    Grivas, G; Cheristanidis, S; Chaloulakou, A

    2012-01-01

    Elemental and organic carbon (EC and OC) hourly concentrations were measured continuously, at an urban location in central Athens, Greece, for an 8-month period (January-August). Average concentrations of 2.2 μgC m(-3) and 6.8 μgC m(-3) were observed, for EC and OC, respectively. The combined contribution of carbonaceous compounds (EC plus organic matter) to PM(10) was calculated at 26%. The seasonal variability of EC was limited, while OC mean concentrations were significantly higher (by 23%), during the warm months (May-August). The weekly variation followed a different pattern, with the weekend decrease of EC levels (25%) being more pronounced than of OC (14%). EC produced a bimodal diurnal cycle, with the morning rush hour traffic mode prevailing. The OC mean circadian variation displayed those peaks as well. However, midday-to-afternoon presence of secondary organic aerosol (SOA) was strongly indicated. The conditional probability function was used to assess the impact of wind direction. High EC, OC levels were linked to southern flows, which during summer are mainly related to the appearance of sea breeze circulation. The temporal variation of EC, OC and their correlation patterns with primary and secondary gaseous pollutants, suggested that, although primary emissions affected both fractions, SOA formation is an important factor to be accounted for, especially during the photochemical season. Secondary organic carbon was estimated using the EC tracer method and orthogonal regression on OC, EC hourly concentration data. The average contributions of secondary organic carbon (SOC) to OC were calculated at 20.9% for the cold period and 30.3% for the warm period. Maximum values of 58% and 91% were estimated for daily and hourly contributions, respectively. The SOC diurnal variations suggested photochemical formation throughout the year, intensified during summer months, with the correlation coefficient between SOC and the sum of oxidants (NO(2+)O(3)) reaching

  12. Agreement between diurnal variations of intraocular pressure by Tono-Pen and Goldmann applanation tonometer in patients on topical anti-glaucoma medication.

    Science.gov (United States)

    Gupta, Shikha; Sinha, Gautam; Sharma, Reetika; Nayak, Bhagabat; Patil, Bharat; Kashyap, Bibhuti; Shameer, Abdul; Dada, Tanuj

    2016-02-01

    To estimate agreement in diurnal variations of intraocular pressure (IOP) by Tono-Pen (TP) and Goldmann applanation tonometer (GAT) in glaucoma patients on topical anti-glaucoma medication(s). IOP was measured at every 3 h from 7 a.m. to 10 a.m. in 50 eyes of glaucoma patients on topical medication(s). Diurnal fluctuation of IOP by each method was calculated as maximum-minimum IOP in a day. Central corneal thickness (CCT) was measured by ultrasonic pachymeter. There was good correlation between TP and GAT at all times during a day, minimum, and maximum IOPs during a day (Correlation coefficient, 0.706 at 7 a.m., 0.624 at 10 a.m., 0.682 at 1 p.m., 0.814 at 4 p.m., 0.652 at 7 p.m., 0.572 at 10 p.m., 0.668 minimum IOP, 0.689 maximum IOP). Mean IOPs by TP were always higher than GAT at all times during a day. Bland-Altman plots suggested a close relationship between the two sets of readings, and that this relationship was consistent at different times in a day, in maximum IOPs, minimum IOPs and also in fluctuation of IOPs. Linear regression analysis between the differences of diurnal fluctuation (diurnal fluctuation by GAT-diurnal fluctuation by TP) and CCT showed strong association (R 2 = 0.857, p < 0.001). The mean change in difference of diurnal fluctuation (GAT-TP) for a 10-micron increase in CCT was 0.69 mmHg. TP can be considered a reliable alternative to GAT in glaucoma patients for knowing the diurnal control of IOP; however these two methods should not be used interchangeably. Difference of diurnal fluctuation between two methods is dependent on CCT.

  13. Numerical Study of Winter Diurnal Convection Over the City of Krasnoyarsk: Effects of Non-freezing River, Undulating Fog and Steam Devils

    Science.gov (United States)

    Hrebtov, M.; Hanjalić, K.

    2017-06-01

    We performed a numerical simulation of penetrative convection of an inversion-topped weakly stratified atmospheric boundary layer over urban terrain with a strong localized source of heat and moisture. With some simplifications, the case mimics the real environment of the Krasnoyarsk region in Russia where the non-freezing river Yenisei acts as a thermal and humidity source during winter, generating an undulating fog pattern along the river accompanied with scattered `steam devils'. An idealized full diurnal cycle was simulated using an unsteady Reynolds-averaged Navier-Stokes (RANS) three-equation algebraic flux model and the novel buoyancy-accounting functions for treating the ground boundary conditions. The results show a significant effect of the river on the net temperature and moisture distribution. The localized heat and moisture source leads to strong horizontal convection and marked non-uniformity of humidity concentration in the air. An interplay of several distinct large-scale vortex systems leads to a wavy pattern of moisture plumes over the river. The simulations deal with rare natural phenomena and show the capability of the RANS turbulence closure to capture the main features of flow and scalar fields on an affordable, relatively coarse, computational grid.

  14. The visual system of diurnal raptors: updated review.

    Science.gov (United States)

    González-Martín-Moro, J; Hernández-Verdejo, J L; Clement-Corral, A

    2017-05-01

    Diurnal birds of prey (raptors) are considered the group of animals with highest visual acuity (VA). The purpose of this work is to review all the information recently published about the visual system of this group of animals. A bibliographic search was performed in PubMed. The algorithm used was (raptor OR falcon OR kestrel OR hawk OR eagle) AND (vision OR «visual acuity» OR eye OR macula OR retina OR fovea OR «nictitating membrane» OR «chromatic vision» OR ultraviolet). The search was restricted to the «Title» and «Abstract» fields, and to non-human species, without time restriction. The proposed algorithm located 97 articles. Birds of prey are endowed with the highest VA of the animal kingdom. However most of the works study one individual or a small group of individuals, and the methodology is heterogeneous. The most studied bird is the Peregrine falcon (Falco peregrinus), with an estimated VA of 140 cycles/degree. Some eagles are endowed with similar VA. The tubular shape of the eye, the large pupil, and a high density of photoreceptors make this extraordinary VA possible. In some species, histology and optic coherence tomography demonstrate the presence of 2foveas. The nasal fovea (deep fovea) has higher VA. Nevertheless, the exact function of each fovea is unknown. The vitreous contained in the deep fovea could behave as a third lens, adding some magnification to the optic system. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Effects of diurnal adjustment on biases and trends derived from inter-sensor calibrated AMSU-A data

    Science.gov (United States)

    Chen, H.; Zou, X.; Qin, Z.

    2018-03-01

    Measurements of brightness temperatures from Advanced Microwave Sounding Unit-A (AMSU-A) temperature sounding instruments onboard NOAA Polarorbiting Operational Environmental Satellites (POES) have been extensively used for studying atmospheric temperature trends over the past several decades. Intersensor biases, orbital drifts and diurnal variations of atmospheric and surface temperatures must be considered before using a merged long-term time series of AMSU-A measurements from NOAA-15, -18, -19 and MetOp-A.We study the impacts of the orbital drift and orbital differences of local equator crossing times (LECTs) on temperature trends derivable from AMSU-A using near-nadir observations from NOAA-15, NOAA-18, NOAA-19, and MetOp-A during 1998-2014 over the Amazon rainforest. The double difference method is firstly applied to estimation of inter-sensor biases between any two satellites during their overlapping time period. The inter-calibrated observations are then used to generate a monthly mean diurnal cycle of brightness temperature for each AMSU-A channel. A diurnal correction is finally applied each channel to obtain AMSU-A data valid at the same local time. Impacts of the inter-sensor bias correction and diurnal correction on the AMSU-A derived long-term atmospheric temperature trends are separately quantified and compared with those derived from original data. It is shown that the orbital drift and differences of LECTamong different POESs induce a large uncertainty in AMSU-A derived long-term warming/cooling trends. After applying an inter-sensor bias correction and a diurnal correction, the warming trends at different local times, which are approximately the same, are smaller by half than the trends derived without applying these corrections.

  16. Observing Seasonal and Diurnal Hydrometeorological Variability Within a Tropical Alpine Valley: Implications for Evapotranspiration

    Science.gov (United States)

    Hellstrom, R. A.; Mark, B. G.

    2007-12-01

    Conditions of glacier recession in the seasonally dry tropical Peruvian Andes motivate research to better constrain the hydrological balance in alpine valleys. There is an outstanding need to better understand the impact of the pronounced tropical hygric seasonality on energy and water budgets within pro-glacial valleys that channel glacier runoff to stream flow. This paper presents a novel embedded network installed in the glacierized Llanganuco valley of the Cordillera Blanca (9°S) comprising eight low-cost, discrete temperature and humidity microloggers ranging from 3470 to 4740 masl and an automatic weather station at 3850 masl. Data are aggregated into distinct dry and wet periods sampled from two full annual cycles (2004-2006) to explore patterns of diurnal and seasonal variability. The magnitude of diurnal solar radiation varies little within the valley between the dry and wet periods, while wet season near-surface air temperatures are cooler. Seasonally characteristic diurnal fluctuations in lapse rate partially regulate convection and humidity. Steep lapse rates during the wet season afternoon promote up-slope convection of warm, moist air and nocturnal rainfall events. Standardized grass reference evapotranspiration (ET0) was estimated using the FAO-56 algorithm of the United Nations Food and Agriculture Organization and compared with estimates of actual ET from the process-based BROOK90 model that incorporates more realistic vegetation parameters. Comparisons of composite diurnal cycles of ET for the wet and dry periods suggest about twice the daily ET0 during the dry period, attributed primarily to the 500% higher vapor pressure deficit and 20% higher daily total solar irradiance. Conversely, the near absence of rainfall during the dry season diminishes actual ET below that of the wet season by two orders of magnitude. Nearly cloud-free daylight conditions are critical for ET during the wet season. We found significant variability of ET with elevation

  17. Gene Expression of Pneumocystis murina after Treatment with Anidulafungin Results in Strong Signals for Sexual Reproduction, Cell Wall Integrity, and Cell Cycle Arrest, Indicating a Requirement for Asci Formation for Proliferation.

    Science.gov (United States)

    Cushion, Melanie T; Ashbaugh, Alan; Hendrix, Keeley; Linke, Michael J; Tisdale, Nikeya; Sayson, Steven G; Porollo, Aleksey

    2018-02-20

    The echinocandins are a class of anti-fungal agents that target β-1,3-D-glucan (BG) biosynthesis. In the ascigerous Pneumocystis species, treatment with these drugs deplete the asci life cycle stage which contain BG, but large numbers of forms which do not express BG remain in the infected lungs. In the present study, the gene expression profiles of Pneumocystis murina were compared between infected untreated mice and those treated with anidulafungin for 2 weeks to understand the metabolism of the persisting forms. Almost 80 genes were significantly up- or down-regulated. Like other fungi exposed to echinocandins, genes associated with sexual replication, cell wall integrity, cell cycle arrest and stress comprised the strongest up-regulated signals in P. murina from the treated mice. The up-regulation of the P. murina β-1,3-D-glucan endohydrolase and endo-1,3-glucanase was notable and may explain the disappearance of the existing asci in the lungs of treated mice since both enzymes can degrade BG. The biochemical measurement of BG in the lungs of treated mice and fluorescent microscopy with an anti-BG antibody supported the loss of BG. Down-regulated signals included genes involved in cell replication, genome stability, ribosomal biogenesis and function, and the Pneumocystis -specific genes encoding the major surface glycoproteins (Msg). These studies suggest that P. murina attempted to undergo sexual replication in response to a stressed environment and were halted in any type of proliferative cycle, likely due to a lack of BG. Asci appear to be a required part of the life cycle stage of Pneumocystis and BG may be needed to facilitate progression through the life cycle via sexual replication. Copyright © 2018 Cushion et al.

  18. Cyanobacteria gene and protein sequences in diurnal oscillation metabolic processes

    Science.gov (United States)

    Tremberger, George, Jr.; Holden, T.; Cheung, E.; Dehipawala, S.; Gadura, N.; Golebiewska, U.; Valentin, K.; Smulczeski, M.; Satizabal, W.; Schneider, P.; Lieberman, D.; Cheung, T.

    2010-09-01

    Daytime photosynthesis and nighttime nitrogen fixation metabolic processes have been reported in the bacterium, Cyanothece 51142. The organism's auto-fluorescence with 532 nm excitation would place cyanobacteria at the forefront in the remote sensing of microbial activity in astrobiology. The sensitivity of nitrogenase to oxygen was studied in terms of sequence nucleotide fluctuation. A nucleotide sequence fractal dimension can be calculated from a numerical series consisting of the atomic numbers of each nucleotide. The fractal dimension and Shannon entropy form a two-dimensional measure that is useful in assessing evolutionary pressures. The studied sequences include nitrogenase iron protein NifH, nitrogenase molybdenum-iron protein alpha chain NifD and beta chain NifK. The photosynthesis-lacking UCYN-A cyanobacterium as reported recently in the journal, Nature, was observed to have the lowest entropy with relatively high fractal dimension values in the studied NifH, NifD and NifH sequences. The fractal dimension of NifH sequences correlates with the NifD sequence values with an R-square of 0.91 (N = 8). The Shannon mononucleotide entropy of NifD sequences correlates with the NifK sequence values with an R-square value of 0.92 (N = 8). The observed strong correlation suggests the presence of gradual evolutionary pressure among the studied cyanobacteria, and throws light on the reported paradox in evolution for the case of UCYN-A. The results show that diurnal oscillation metabolic processes in cyanobacteria (including the photosynthesis-deficient case) are not associated with extraordinary evolutionary pressures and thus are processes consistent with putative astrobiological organisms.

  19. Changes in the diurnal rhythms of cortisol, melatonin, and testosterone after 2, 4, and 7 consecutive night shifts in male police officers

    DEFF Research Database (Denmark)

    Jensen, Marie Aarrebo; Hansen, Åse Marie; Kristiansen, Jesper

    2016-01-01

    the effects of consecutive night shifts on three hormones, melatonin, cortisol, and testosterone, among police officers at work. More specifically, the aim was to investigate how the diurnal rhythms of melatonin, cortisol, and testosterone responded to two, four, and seven consecutive night shifts...... 4th hour when awake. The diurnal rhythms of melatonin, cortisol, and testosterone were all affected differently by an increasing number of consecutive night shifts: the amplitude of the melatonin rhythm was suppressed by 4.9% per day (95% CI 1.4–8.2% per day; p = 0.006). The diurnal rhythm...... followed the sleep/wake cycle. We found that there were no differences in the rhythms of melatonin, cortisol, and testosterone after 2, 4, and 7 recovery days, respectively. In conclusion, we found signs of desynchronization in terms of suppressed amplitude of melatonin and phase delay of salivary cortisol...

  20. Progress in Research on Diurnal and Semidiurnal Earth Rotation Change

    Science.gov (United States)

    Xu, Xueqing

    2015-08-01

    We mainly focus on the progress of research on high frequency changes in the earth rotation. Firstly, we review the development course and main motivating factors of the diurnal and semidiurnal earth rotation change. In recent decades, earth orientation has been monitored with increasing accuracy by advanced space-geodetic techniques, including lunar and satellite laser ranging, very long baseline interferometry and the global positioning system. We are able to obtain the Earth Rotation Parameters (ERP, polar motion and rotation rate changes) by even 1 to 2 hours observation data, form which obvious diurnal and semidiurnal signals can be detected, and compare them with the predicted results by the ocean model. Both the amplitude and phase are in good agreement in the main diurnal and semidiurnal wave frequency, especially for the UT1, whose compliance is 90%, and 60% for polar motion, there are 30% motivating factor of the diurnal and semidiurnal polar motion have not been identified. Then we comprehensively review the different types of global ocean tidal correction models since the last eighties century, as well as the application research on diurnal and semidiurnal polar motion and UT1, the current ocean tidal correction models have 10% to 20% uncertainty, and need for further refinement.

  1. Strong, weak, and missing links in microbial community of the N.W. Mediterranean Sea

    Czech Academy of Sciences Publication Activity Database

    Bettarel, Y.; Dolan, J. R.; Horňák, Karel; Lemée, R.; Mašín, Michal; Pedrotti, M. L.; Rochelle-Newall, E.; Šimek, Karel; Sime-Ngando, T.

    2002-01-01

    Roč. 42, č. 3 (2002), s. 451-462 ISSN 0168-6496 Grant - others:CNRS-PICS(FR) project 1111 Keywords : microbial abundances and activities * diurnal cycles * trophic and functional links Subject RIV: EE - Microbiology, Virology Impact factor: 2.589, year: 2002

  2. Combined effects of surface conditions, boundary layer dynamics and chemistry on diurnal SOA evolution

    Directory of Open Access Journals (Sweden)

    R. H. H. Janssen

    2012-08-01

    Full Text Available We study the combined effects of land surface conditions, atmospheric boundary layer dynamics and chemistry on the diurnal evolution of biogenic secondary organic aerosol in the atmospheric boundary layer, using a model that contains the essentials of all these components. First, we evaluate the model for a case study in Hyytiälä, Finland, and find that it is able to satisfactorily reproduce the observed dynamics and gas-phase chemistry. We show that the exchange of organic aerosol between the free troposphere and the boundary layer (entrainment must be taken into account in order to explain the observed diurnal cycle in organic aerosol (OA concentration. An examination of the budgets of organic aerosol and terpene concentrations show that the former is dominated by entrainment, while the latter is mainly driven by emission and chemical transformation. We systematically investigate the role of the land surface, which governs both the surface energy balance partitioning and terpene emissions, and the large-scale atmospheric process of vertical subsidence. Entrainment is especially important for the dilution of organic aerosol concentrations under conditions of dry soils and low terpene emissions. Subsidence suppresses boundary layer growth while enhancing entrainment. Therefore, it influences the relationship between organic aerosol and terpene concentrations. Our findings indicate that the diurnal evolution of secondary organic aerosols (SOA in the boundary layer is the result of coupled effects of the land surface, dynamics of the atmospheric boundary layer, chemistry, and free troposphere conditions. This has potentially some consequences for the design of both field campaigns and large-scale modeling studies.

  3. Diurnal microstructural variations in healthy adult brain revealed by diffusion tensor imaging.

    Directory of Open Access Journals (Sweden)

    Chunxiang Jiang

    Full Text Available Biorhythm is a fundamental property of human physiology. Changes in the extracellular space induced by cell swelling in response to the neural activity enable the in vivo characterization of cerebral microstructure by measuring the water diffusivity using diffusion tensor imaging (DTI. To study the diurnal microstructural alterations of human brain, fifteen right-handed healthy adult subjects were recruited for DTI studies in two repeated sessions (8∶30 AM and 8∶30 PM within a 24-hour interval. Fractional anisotropy (FA, apparent diffusion coefficient (ADC, axial (λ// and radial diffusivity (λ⊥ were compared pixel by pixel between the sessions for each subject. Significant increased morning measurements in FA, ADC, λ// and λ⊥ were seen in a wide range of brain areas involving frontal, parietal, temporal and occipital lobes. Prominent evening dominant λ⊥ (18.58% was detected in the right inferior temporal and ventral fusiform gyri. AM-PM variation of λ⊥ was substantially left side hemisphere dominant (p<0.05, while no hemispheric preference was observed for the same analysis for ADC (p = 0.77, λ// (p = 0.08 or FA (p = 0.25. The percentage change of ADC, λ//, λ⊥, and FA were 1.59%, 2.15%, 1.20% and 2.84%, respectively, for brain areas without diurnal diffusivity contrast. Microstructural variations may function as the substrates of the phasic neural activities in correspondence to the environment adaptation in a light-dark cycle. This research provided a baseline for researches in neuroscience, sleep medicine, psychological and psychiatric disorders, and necessitates that diurnal effect should be taken into account in following up studies using diffusion tensor quantities.

  4. Diurnal variations of humidity and ice water content in the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    P. Eriksson

    2010-12-01

    Full Text Available Observational results of diurnal variations of humidity from Odin-SMR and AURA-MLS, and cloud ice mass from Odin-SMR and CloudSat are presented for the first time. Comparisons show that the retrievals of humidity and cloud ice from these two satellite combinations are in good agreement. The retrieved data are combined from four almost evenly distributed times of the day allowing mean values, amplitudes and phases of the diurnal variations around 200 hpa to be estimated. This analysis is applied to six climatologically distinct regions, five located in the tropics and one over the subtropical northern Pacific Ocean. The strongest diurnal cycles are found over tropical land regions, where the amplitude is ~7 RHi for humidity and ~50% for ice mass. The greatest ice mass for these regions is found during the afternoon, and the humidity maximum is observed to lag this peak by ~6 h. Over tropical ocean regions the variations are smaller and the maxima in both ice mass and humidity are found during the early morning. Observed results are compared with output from three climate models (ECHAM, EC-EARTH and CAM3. Direct measurement-model comparisons were not possible because the measured and modelled cloud ice masses represent different quantities. To make a meaningful comparison, the amount of snow had to be estimated from diagnostic parameters of the models. There is a high probability that the models underestimate the average ice mass (outside the 1-σ uncertainty. The models also show clear deficiencies when it comes to amplitude and phase of the regional variations, but to varying degrees.

  5. Reduced peak, but no diurnal variation, in thrombin generation upon melatonin supplementation in tetraplegia. A randomised, placebo-controlled study.

    Science.gov (United States)

    Iversen, Per Ole; Dahm, Anders; Skretting, Grethe; Mowinckel, Marie-Christine; Stranda, Annicke; Østerud, Bjarne; Sandset, Per Morten; Kostovski, Emil

    2015-11-01

    Tetraplegic patients have increased risk of venous thrombosis despite anti-thrombotic prophylaxis. Moreover, they have blunted plasma variations in melatonin and altered diurnal variation of several haemostatic markers, compared with able-bodied. However, whether healthy individuals and tetraplegic patients, with or without melatonin, display abnormalities in thrombin generation during a 24-hour (h) cycle, is unknown. We therefore used the Calibrated Automated Thrombogram (CAT) assay to examine diurnal variations and the possible role of melatonin in thrombin generation. Six men with long-standing complete tetraplegia were included in a randomised placebo-controlled cross-over study with melatonin supplementation (2 mg, 4 consecutive nights), whereas six healthy, able-bodied men served as controls. Ten plasma samples were collected frequently during a 24-h awake/sleep cycle. No significant diurnal variation of any of the measured CAT indices was detected in the three study groups. Whereas endogenous thrombin potential (ETP) was independent (p > 0.05) of whether the tetraplegic men received melatonin or placebo, melatonin decreased (p = 0.005) peak values in tetraplegia compared with those given placebo. Able-bodied men had lower (p = 0.019) ETP and Lag-Time (p = 0.018) compared with tetraplegics receiving placebo. Neither the Time-to-Peak nor the Start-Tail was affected (p > 0.05) by melatonin in tetraplegia. In conclusion, indices of thrombin generation are not subjected to diurnal variation in healthy able-bodied or tetraplegia, but peak thrombin generation is reduced in tetraplegic men receiving oral melatonin.

  6. Interaction with diurnal and circadian regulation results in dynamic metabolic and transcriptional changes during cold acclimation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Carmen Espinoza

    Full Text Available In plants, there is a large overlap between cold and circadian regulated genes and in Arabidopsis, we have shown that cold (4°C affects the expression of clock oscillator genes. However, a broader insight into the significance of diurnal and/or circadian regulation of cold responses, particularly for metabolic pathways, and their physiological relevance is lacking. Here, we performed an integrated analysis of transcripts and primary metabolites using microarrays and gas chromatography-mass spectrometry. As expected, expression of diurnally regulated genes was massively affected during cold acclimation. Our data indicate that disruption of clock function at the transcriptional level extends to metabolic regulation. About 80% of metabolites that showed diurnal cycles maintained these during cold treatment. In particular, maltose content showed a massive night-specific increase in the cold. However, under free-running conditions, maltose was the only metabolite that maintained any oscillations in the cold. Furthermore, although starch accumulates during cold acclimation we show it is still degraded at night, indicating significance beyond the previously demonstrated role of maltose and starch breakdown in the initial phase of cold acclimation. Levels of some conventional cold induced metabolites, such as γ-aminobutyric acid, galactinol, raffinose and putrescine, exhibited diurnal and circadian oscillations and transcripts encoding their biosynthetic enzymes often also cycled and preceded their cold-induction, in agreement with transcriptional regulation. However, the accumulation of other cold-responsive metabolites, for instance homoserine, methionine and maltose, did not have consistent transcriptional regulation, implying that metabolic reconfiguration involves complex transcriptional and post-transcriptional mechanisms. These data demonstrate the importance of understanding cold acclimation in the correct day-night context, and are further

  7. Some features of Pc5 pulsations during a solar cycle

    International Nuclear Information System (INIS)

    Rao, D.R.K.; Gupta, J.C.

    1978-01-01

    The morphological features of Pc5 pulsations during a solar cycle are studied using Fort Churchill data for the years 1962 to 1972. Some of the characteristics noted are as follows: (1) Increasing sunspot numbers show little influence on the diurnal variations of the occurrence, amplitude and the period except perhaps some noticeable change in the absolute magnitude of these parameters during different hours of the day. (2) The morning occurrence peak dominates during all phases of the solar cycle. (3) With increasing magnetic activity the day side region(s) of generation of Pc5 is found to shift closer to the subsolar point and in the midnight sector, the occurrence region seemed to shift towards earlier hours with increasing magnetic activity and towards later hours with increasing sunspot numbers. (4) The amplitude of Pc5 pulsations is directly related to all the levels of magnetic activity. (5) The periods of Pc5 pulsations show strong correlation with increasing sunspot numbers and the amplitude and occurrences are found to vary in accordance with the magnetic activity all through the cycle. (6) The annual and semi-annual variations of Pc5 parameters have been demonstrated especially for the pulsations occurring in the morning close to 8 +- 1 h LT and for those occurring near the midnight hours. (7) a suspected 27-day recurrence tendency has been clearly noticed for the occurrence, amplitude and period of Pc5 pulsations. (author)

  8. Diurnal Regulation of Cellular Processes in the Cyanobacterium Synechocystis sp. Strain PCC 6803: Insights from Transcriptomic, Fluxomic, and Physiological Analyses

    Directory of Open Access Journals (Sweden)

    Rajib Saha

    2016-05-01

    Full Text Available Synechocystis sp. strain PCC 6803 is the most widely studied model cyanobacterium, with a well-developed omics level knowledgebase. Like the lifestyles of other cyanobacteria, that of Synechocystis PCC 6803 is tuned to diurnal changes in light intensity. In this study, we analyzed the expression patterns of all of the genes of this cyanobacterium over two consecutive diurnal periods. Using stringent criteria, we determined that the transcript levels of nearly 40% of the genes in Synechocystis PCC 6803 show robust diurnal oscillating behavior, with a majority of the transcripts being upregulated during the early light period. Such transcripts corresponded to a wide array of cellular processes, such as light harvesting, photosynthetic light and dark reactions, and central carbon metabolism. In contrast, transcripts of membrane transporters for transition metals involved in the photosynthetic electron transport chain (e.g., iron, manganese, and copper were significantly upregulated during the late dark period. Thus, the pattern of global gene expression led to the development of two distinct transcriptional networks of coregulated oscillatory genes. These networks help describe how Synechocystis PCC 6803 regulates its metabolism toward the end of the dark period in anticipation of efficient photosynthesis during the early light period. Furthermore, in silico flux prediction of important cellular processes and experimental measurements of cellular ATP, NADP(H, and glycogen levels showed how this diurnal behavior influences its metabolic characteristics. In particular, NADPH/NADP+ showed a strong correlation with the majority of the genes whose expression peaks in the light. We conclude that this ratio is a key endogenous determinant of the diurnal behavior of this cyanobacterium.

  9. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Orby, P.V.; Skjoth, C. A.

    2014-01-01

    In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  10. Central melanopsin projections in the diurnal rodent, Arvicanthis niloticus

    DEFF Research Database (Denmark)

    Langel, Jennifer L; Smale, Laura; Esquiva, Gema

    2015-01-01

    The direct effects of photic stimuli on behavior are very different in diurnal and nocturnal species, as light stimulates an increase in activity in the former and a decrease in the latter. Studies of nocturnal mice have implicated a select population of retinal ganglion cells that are intrinsica......The direct effects of photic stimuli on behavior are very different in diurnal and nocturnal species, as light stimulates an increase in activity in the former and a decrease in the latter. Studies of nocturnal mice have implicated a select population of retinal ganglion cells...... projections of ipRGCs by examining the distribution of immunoreactive PACAP fibers in intact and enucleated animals. This revealed evidence that these cells project to the suprachiasmatic nucleus, lateral geniculate nucleus (LGN), pretectum, and superior colliculus. This distribution was confirmed...... in nocturnal rodents. Overall, these data suggest that although ipRGCs and their projections are very similar in diurnal and nocturnal rodents, they may not be identical....

  11. SST Diurnal Variability: Regional Extent & Implications in Atmospheric Modelling

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, Jacob L.

    2013-01-01

    The project Sea Surface Temperature Diurnal Variability: Regional Extent and Implications in Atmospheric Modeling (SSTDV: R.EX.- IM.A.M.) was initiated within the framework of the European Space Agency's Support to Science Element (ESA STSE). The main focus is twofold: i) to characterize...... and quantify regional diurnal warming from the experimental MSG/SEVIRI hourly SST fields, for the period 2006-2012. ii) To investigate the impact of the increased SST temporal resolution in the atmospheric model WRF, in terms of modeled 10-m winds and surface heat fluxes. Withing this context, 3 main tasks...... SST variability on atmospheric modeling is the prime goal of the third and final task. This will be examined by increasing the temporal resolution of the SST initial conditions in WRF and by evaluating the WRF included diurnal scheme. Validation of the modeled winds will be performed against 10m ASAR...

  12. Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Simon [Reading Univ. (United Kingdom). Dept. of Meteorology; Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.; Owens, Mathew; Lockwood, Mike [Reading Univ. (United Kingdom). Dept. of Meteorology; Owen, Chris [Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.

    2017-10-01

    The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the A<0 cycles and A>0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1-2 h between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between A>0 and A<0 polarity cycles, suggesting a slight change in the anisotropy vector of GCRs arriving at Earth between polarity cycles. Polar neutron monitors show differences in phase between polarity cycles which have asymptotic directions at mid-to-high latitudes. All neutron monitors show changes in the amplitude of the

  13. Diurnal Salivary Alpha-amylase Dynamics among Dementia Family Caregivers

    Science.gov (United States)

    Liu, Yin; Granger, Douglas A.; Kim, Kyungmin; Klein, Laura C.; Almeida, David M.; Zarit, Steven H.

    2016-01-01

    Objective The study examined diurnal regulation of salivary alpha-amylase (sAA) in association with daily stressors, adult day services (ADS) use, and other caregiving characteristics. Methods A sample of 165 family caregivers of individuals with dementia (IWD) completed an 8-day diary study. Caregivers provided 5 saliva samples across the 8 days. On some days, caregivers provided all or most of the care. On other days, their relative attended ADS for part of the day. A 3-level unconditional linear spline model was fit to describe the typical sAA diurnal rhythms. Predictors were then added to the unconditional model to test the hypotheses on ADS use and daily stressors. Results Daily ADS use did not have an effect on diurnal sAA regulation. However, controlling for daily ADS use, greater ADS use over the 8 days was associated with a more prominent rise between 30 minutes after wake-up and before lunch, and a more prominent decline between before lunch and late afternoon. Fewer ADS days were associated with a more flattened sAA diurnal rhythm. Additionally, greater daily care-related stressor exposures had a within-person association with lower sAA levels in the late afternoon. Care-related stressor exposures had significant within- and between-person associations with sAA diurnal slopes. Furthermore, daily positive experiences had a significant between-person association with sAA diurnal slopes. Conclusions Caring for a disabled family member may heighten the vulnerability to potential physiological conditions. Respite from care stressors from ADS use may have some biobehavioral benefits on sAA regulations. PMID:27786517

  14. Carbon availability affects diurnally controlled processes and cell morphology of Cyanothece 51142.

    Directory of Open Access Journals (Sweden)

    Jana Stöckel

    Full Text Available Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria to convert solar energy and high concentrations of CO2 efficiently into biomass and renewable energy sources has sparked substantial interest in using flue gas from coal-burning power plants as a source of inorganic carbon. However, in order to guide further advances in this area, a better understanding of the metabolic changes that occur under conditions of high CO2 is needed. To determine the effect of high CO2 on cell physiology and growth, we analyzed the global transcriptional changes in the unicellular diazotrophic cyanobacterium Cyanothece 51142 grown in 8% CO2-enriched air. We found a concerted response of genes related to photosynthesis, carbon metabolism, respiration, nitrogen fixation, ribosome biosynthesis, and the synthesis of nucleotides and structural cell wall polysaccharides. The overall response to 8% CO2 in Cyanothece 51142 involves different strategies, to compensate for the high C/N ratio during both phases of the diurnal cycle. Our analyses show that high CO2 conditions trigger the production of carbon-rich compounds and stimulate processes such as respiration and nitrogen fixation. In addition, we observed that high levels of CO2 affect fundamental cellular processes such as cell growth and dramatically alter the intracellular morphology. This study provides novel insights on how diurnal and developmental rhythms are integrated to facilitate adaptation to high CO2 in Cyanothece 51142.

  15. Diurnal rhythms in neurexins transcripts and inhibitory/excitatory synapse scaffold proteins in the biological clock.

    Science.gov (United States)

    Shapiro-Reznik, Mika; Jilg, Anje; Lerner, Hadas; Earnest, David J; Zisapel, Nava

    2012-01-01

    The neurexin genes (NRXN1/2/3) encode two families (α and β) of highly polymorphic presynaptic proteins that are involved in excitatory/inhibitory synaptic balance. Recent studies indicate that neuronal activation and memory formation affect NRXN1/2/3α expression and alternative splicing at splice sites 3 and 4 (SS#3/SS#4). Neurons in the biological clock residing in the suprachiasmatic nuclei of the hypothalamus (SCN) act as self-sustained oscillators, generating rhythms in gene expression and electrical activity, to entrain circadian bodily rhythms to the 24 hours day/night cycles. Cell autonomous oscillations in NRXN1/2/3α expression and SS#3/SS#4 exons splicing and their links to rhythms in excitatory/inhibitory synaptic balance in the circadian clock were explored. NRXN1/2/3α expression and SS#3/SS#4 splicing, levels of neurexin-2α and the synaptic scaffolding proteins PSD-95 and gephyrin (representing excitatory and inhibitory synapses, respectively) were studied in mRNA and protein extracts obtained from SCN of C3H/J mice at different times of the 24 hours day/night cycle. Further studies explored the circadian oscillations in these components and causality relationships in immortalized rat SCN2.2 cells. Diurnal rhythms in mNRXN1α and mNRXN2α transcription, SS#3/SS#4 exon-inclusion and PSD-95 gephyrin and neurexin-2α levels were found in the SCN in vivo. No such rhythms were found with mNRXN3α. SCN2.2 cells also exhibited autonomous circadian rhythms in rNRXN1/2 expression SS#3/SS#4 exon inclusion and PSD-95, gephyrin and neurexin-2α levels. rNRXN3α and rNRXN1/2β were not expressed. Causal relationships were demonstrated, by use of specific siRNAs, between rNRXN2α SS#3 exon included transcripts and gephyrin levels in the SCN2.2 cells. These results show for the first time dynamic, cell autonomous, diurnal rhythms in expression and splicing of NRXN1/2 and subsequent effects on the expression of neurexin-2α and postsynaptic scaffolding proteins

  16. Associations between self-reported discrimination and diurnal cortisol rhythms among young adults: The moderating role of racial-ethnic minority status.

    Science.gov (United States)

    Zeiders, Katharine H; Hoyt, Lindsay T; Adam, Emma K

    2014-12-01

    Discrimination is theorized to set in motion a neuroendocrine response, which includes cortisol secretion from the hypothalamic-pituitary-adrenal axis. Repeated exposure to perceived discrimination is thought to contribute to alterations in diurnal cortisol rhythms and to have implications for health. Discrimination may have particularly strong effects on racial/ethnic minority individuals, based on histories of past exposure and/or greater perceived implications of discriminatory events. Utilizing an ethnically and racially diverse sample of young adults (N=140; Mage=22.8 years) and a multiple-day naturalistic cortisol protocol, the present study examined associations between self-reported discrimination and diurnal cortisol rhythms, and whether this relation was moderated by racial/ethnic minority status. Results revealed that self-reported discrimination predicted flatter diurnal cortisol slopes for racial/ethnic minority individuals only. These findings align with theory suggesting that discrimination experiences are important among racial/ethnic minorities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. A framework for global diurnally-resolved observations of Land Surface Temperature

    Science.gov (United States)

    Ghent, D.; Remedios, J.; Pinnock, S.

    2013-12-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Being a key boundary condition in land surface models, which determine the surface to atmosphere fluxes of heat, water and carbon; thus influencing cloud cover, precipitation and atmospheric chemistry predictions within Global models, the requirement for global diurnal observations of LST is well founded. Earth Observation satellites offer an opportunity to obtain global coverage of LST, with the appropriate exploitation of data from multiple instruments providing a capacity to resolve the diurnal cycle on a global scale. Here we present a framework for the production of global, diurnally resolved, data sets for LST which is a key request from users of LST data. We will show how the sampling of both geostationary and low earth orbit data sets could conceptually be employed to build combined, multi-sensor, pole-to-pole data sets. Although global averages already exist for individual instruments and merging of geostationary based LST is already being addressed operationally (Freitas, et al., 2013), there are still a number of important challenges to overcome. In this presentation, we will consider three of the issues still open in LST remote sensing: 1) the consistency amongst retrievals; 2) the clear-sky bias and its quantification; and 3) merging methods and the propagation of uncertainties. For example, the combined use of both geostationary earth orbit (GEO) and low earth orbit (LEO) data, and both infra-red and microwave data are relatively unexplored but are necessary to make the most progress. Hence this study will suggest what is state-of-the-art and how considerable advances can be made, accounting also for recent improvements in techniques and data quality. The GlobTemperature initiative under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013

  18. Inferring hydraulic properties of alpine aquifers from the propagation of diurnal snowmelt signals

    Science.gov (United States)

    Kurylyk, Barret L.; Hayashi, Masaki

    2017-05-01

    Alpine watersheds source major rivers throughout the world and supply essential water for irrigation, human consumption, and hydroelectricity. Coarse depositional units in alpine watersheds can store and transmit significant volumes of groundwater and thus augment stream discharge during the dry season. These environments are typically data scarce, which has limited the application of physically based models to investigate hydrologic sensitivity to environmental change. This study focuses on a coarse alpine talus unit within the Lake O'Hara watershed in the Canadian Rockies. We investigate processes controlling the hydrologic functioning of the talus unit using field observations and a numerical groundwater flow model driven with a distributed snowmelt model. The model hydraulic parameters are adjusted to investigate how these properties influence the propagation of snowmelt-induced diurnal signals. The model results expectedly demonstrate that diurnal signals at the talus outlet are progressively damped and lagged with lower hydraulic conductivity and higher specific yield. The simulations further indicate that the lag can be primarily controlled by a higher hydraulic conductivity upper layer, whereas the damping can be strongly influenced by a lower hydraulic conductivity layer along the base of the talus. The simulations specifically suggest that the talus slope can be represented as a two layer system with a high conductivity zone (0.02 m s-1) overlying a 10 cm thick lower conductivity zone (0.002 m s-1). This study demonstrates that diurnal signals can be used to elucidate the hydrologic functioning and hydraulic properties of shallow aquifers and thus aid in the parameterization of hydrological models.

  19. A numerical simulation of climate changes during the obliquity cycle on Mars

    International Nuclear Information System (INIS)

    Francois, L.M.; Walker, J.C.G.; Kuhn, W.R.

    1990-01-01

    A one-dimensional seasonal energy balance climate model has been developed for the Martian surface and coupled to a model of CO 2 distribution between atmosphere, regolith, and polar caps. This model takes into account the greenhouse warming of carbon dioxide, the meridional transport of heat, the CO 2 condensation and sublimation cycle, and its adsorption in the regolith. The model takes into consideration the diurnal variation of solar irradiation, since it is shown that disregard of this effect yields temperatures too high by several degrees. The yearly-averaged temperatures calculated from this climate model at different obliquities are used to estimate the importance of CO 2 exchanges between the regolith and atmosphere-cap systems during the obliquity cycle. For this purpose, the equation of thermal diffusion into the ground is solved for each latitude belt. The results differ substantially from those of previous studies, due in part to the consideration of the diurnal and seasonal variations of the solar irradiance. The model shows the importance of taking these short-period variations into account instead of using yearly-averaged quantities, due to the strong nonlinearity of the climate system on Mars. The roles of meridional heat transport and greenhouse warming are analyzed and shown to be important. For example, a permanent polar cap of carbon dioxide is destroyed by heat transport when the obliquity is high, while at low obliquity, high-pressure systems without permanent cap can exist if enough exchangeable carbon dioxide is available. Further, the results show the possible existence of hysteresis cycles in the formation and sublimation of permanent deposits during the course of the obliquity cycle

  20. LIS 0.1 DEGREE VERY HIGH RESOLUTION GRIDDED LIGHTNING DIURNAL CLIMATOLOGY (VHRDC) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The LIS 0.1 Degree Very High Resolution Gridded Lightning Diurnal Climatology (VHRDC) dataset consists of gridded diurnal climatologies of total lightning flash...

  1. Menstrual Cycle

    Science.gov (United States)

    ... To receive General email updates Enter email Submit Menstrual Cycle The menstrual cycle is the hormonal process ... Preventing problems with your menstrual cycle View more Menstrual Cycle resources Related information Endometriosis Infertility Polycystic ovary ...

  2. Daytime passerine migrants over the Sahara — are these diurnal ...

    African Journals Online (AJOL)

    When crossing the Sahara it was expected that nocturnal migrants would continue their flight into the day. We investigated whether migration taking place in the Sahara during daytime comprises the normal diurnal migrant species or the nocturnal ones prolonging their flight into the day. Birds departing from the Sahel in ...

  3. Diurnal variation of precipitation over the Carolina Sandhills region

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 119; Issue 5. Diurnal ... North American Mesoscale (NAM)model forecasts for the summers of 2004 to 2006 were evaluated using observations. ... This feature is attributed to model physics not capturing cloud –radiation interaction processes dominant during nights.

  4. Diurnal Fluctuations in Rectal Temperature of Sahel Goats During ...

    African Journals Online (AJOL)

    Experiments were performed on 10 adult Sahel goats with the aim of determining their diurnal temperature fluctuations during the hot dry season. The rectal temperatures (RT) were recorded with a standard clinical thermometer every hour from 06:00 to 19:00 hours. The RT of goats rose gradually from its minimum value of ...

  5. Diurnal Fluctuations in Rectal Temperature of Local Chickens ...

    African Journals Online (AJOL)

    Experiments were performed on 10 local Chickens with the aim of determining their diurnal temperature fluctuations during the hot dry season (April) in Maiduguri, Borno State. The rectal temperatures (RT) were recorded with a standard clinical thermometer every hour from 06.00 to 19.00 hours. The RT of the chickens rose ...

  6. Diurnal variation of precipitation over the Carolina Sandhills region

    Indian Academy of Sciences (India)

    Diurnal variation of precipitation over the Carolina Sandhills region. 591. Figure 16. WRF forecast local 10 m winds for 1900 Z on 10 August 2001. the analysis should be done with more stations to draw a more robust conclusion on the success of the NAM model. 5. Numerical simulation of convection,. 9–11 August 2001.

  7. Nocturnalism induced by scheduled feeding in diurnal Octodon degus.

    Science.gov (United States)

    Vivanco, Pablo; López-Espinoza, Antonio; Madariaga, Ana Maria; Rol, Maria Angeles; Madrid, Juan Antonio

    2010-01-01

    Octodon degus, a mainly diurnal rodent, characterized by its ability to shift to a nocturnal locomotor pattern under laboratory conditions, was studied to determine whether restricted food access during the scotophase could induce nocturnalism. To address this question, wheel running activity, feeding, and body temperature rhythms were analyzed for diurnal degus housed with a wheel and subjected to either long (12 h) or short (2 h) food availability periods, in the latter case with random or scheduled food access times. The results show that allowing nocturnal feeding for 2 h, but not 12 h, can shift a previous diurnal phase preference for wheel running activity and body temperature to the scotophase, with random feeding being more effective than scheduled food availability. However, this behavioral inversion proved to be unstable, as the degus returned to the diurnal phase within only a few days after the restricted feeding was discontinued. In addition, the negative masking effect induced by light, which is characteristic of the degus' nocturnal chronotype, was not observed when the animals were forced to feed at night. Thus, neither long, short, random, nor scheduled food-availability during the scotophase was able to induce all the characteristics of the nocturnal chronotype in Octodon degus.

  8. 40 CFR 86.133-96 - Diurnal emission test.

    Science.gov (United States)

    2010-07-01

    ... Section 86.133-96 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... emissions from the running loss and hot soak tests is not required as preparation for the diurnal emission... analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to...

  9. 40 CFR 86.1233-96 - Diurnal emission test.

    Science.gov (United States)

    2010-07-01

    ... Section 86.1233-96 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... emissions from the running loss and hot soak tests is not required as preparation for the diurnal emission... analysis. If the 4-minute sample period is inadequate to collect a sample of sufficient concentration to...

  10. Diurnal and Night Change in Greenhouse's Microclimatic Condition ...

    African Journals Online (AJOL)

    Data of climate parameters were collected and analyzed to determine night and diurnal change of solar radiation, air temperature and humidity inside greenhouse, temperature and humidity difference between inside and outside air of a greenhouse, the temperature difference between the soil and the inside air and the ...

  11. Modelling the diurnal variability of SST and its vertical extent

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, Jacob L.; Donlon, Craig J.

    2014-01-01

    of the water column where most of the heat is absorbed and where the exchange of heat and momentum with the atmosphere occurs. During day-time and under favourable conditions of low winds and high insolation, diurnal warming of the upper layer poses challenges for validating and calibrating satellite sensors...

  12. Diurnal dynamics of water quality parameters in an aquaculture ...

    African Journals Online (AJOL)

    Recirculating greenwater aquaculture technology is an appropriate method for producing commercial quantities of tilapia in areas where water is scarce. Greenwater systems achieve better fish production, more than 90% water recycling and nutrient utilization. This study was designed to address the diurnal dynamics of ...

  13. Diurnal Variation in the Basal Emission Rate of Isoprene

    Science.gov (United States)

    Jennifer Funk; Clive G. Jones; Christine J. Baker; Heather M. Fuller; Christian P. Giardina; Manuel T. Lerdua

    2003-01-01

    Isoprene is emitted from numerous plant species and profoundly influences tropospheric chemistry. Due to the short lifetime of isoprene in the atmosphere, developing an understanding of emission patterns at small time scales is essential for modeling regional atmospheric chemistry processes. Previous studies suggest that diurnal fluctuations in isoprene emission may be...

  14. Diurnal Effects on Serum Testosterone and Spermiogram of the ...

    African Journals Online (AJOL)

    This study has shown that there are diurnal effects on serum testosterone concentrations. We therefore suggest that these effects be taken into consideration during natural breeding program(s) as sexual activity or increased libido is probably better expressed during the cooler periods of the day. Nigerian Veterinary Journal ...

  15. Sleep EEG spectral analysis in a diurnal rodent : Eutamias sibiricus

    NARCIS (Netherlands)

    DIJK, DJ; DAAN, S

    1989-01-01

    1. Sleep was studied in the diurnal rodent Eutamias sibiricus, chronically implanted with EEG and EMG electrodes. Analysis of the distribution of wakefulness, nonrapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep over the 24 h period (LD 12:12) showed that total sleep time was 27.5%

  16. diurnal climatic pressure on haematology and blood biochemistry of ...

    African Journals Online (AJOL)

    Twelve 2.5-year-old West African Dward (WAD) sheep consisting of eight (8) ewes and four (4) rams with mean body weight 19.4kg were used to study the effects of diurnal (morning and afternoon) climatic variations on the haematological and biochemical responses in WAD sheep. The animals were randomly assigned to ...

  17. Pathophysiology of diurnal drooling in Parkinson’s disease

    NARCIS (Netherlands)

    Lenie van den Engel-Hoek; Johanna Kalf; Bastiaan Bloem; George Borm; Machiel Zwarts; Bert de Swart; Marten Munneke

    2011-01-01

    Drooling is an incapacitating feature of Parkinson's disease. Better pathophysiological insights are needed to improve treatment. In this study, we tested the hypothesis that the cause of drooling is multifactorial. We examined 15 patients with Parkinson's disease with distinct diurnal saliva loss

  18. Ecological consequences of diurnal flooding in tidal freshwater wetlands

    NARCIS (Netherlands)

    Barendregt, A.; Wassen, M.J.

    2010-01-01

    Diurnal flooding can be observed in the upper end of tidal estuaries, where flooding water originating from the river is constantly fresh. Here, the input from the river is confronted with a tidal wave, so that the sand banks, mud flats, low and high marshes and tidal forests are flooded mostly

  19. Diurnal variation in the performance of rapid response systems: the role of critical care services-a review article.

    Science.gov (United States)

    Sundararajan, Krishnaswamy; Flabouris, Arthas; Thompson, Campbell

    2016-01-01

    The type of medical review before an adverse event influences patient outcome. Delays in the up-transfer of patients requiring intensive care are associated with higher mortality rates. Timely detection and response to a deteriorating patient constitute an important function of the rapid response system (RRS). The activation of the RRS for at-risk patients constitutes the system's afferent limb. Afferent limb failure (ALF), an important performance measure of rapid response systems, constitutes a failure to activate a rapid response team (RRT) despite criteria for calling an RRT. There are diurnal variations in hospital staffing levels, the performance of rapid response systems and patient outcomes. Fewer ward-based nursing staff at night may contribute to ALF. The diurnal variability in RRS activity is greater in unmonitored units than it is in monitored units for events that should result in a call for an RRT. RRT events include a significant abnormality in either the pulse rate, blood pressure, conscious state or respiratory rate. There is also diurnal variation in RRT summoning rates, with most activations occurring during the day. The reasons for this variation are mostly speculative, but the failure of the afferent limb of RRT activation, particularly at night, may be a factor. The term "circadian variation/rhythm" applies to physiological variations over a 24-h cycle. In contrast, diurnal variation applies more accurately to extrinsic systems. Circadian rhythm has been demonstrated in a multitude of bodily functions and disease states. For example, there is an association between disrupted circadian rhythms and abnormal vital parameters such as anomalous blood pressure, irregular pulse rate, aberrant endothelial function, myocardial infarction, stroke, sleep-disordered breathing and its long-term consequences of hypertension, heart failure and cognitive impairment. Therefore, diurnal variation in patient outcomes may be extrinsic, and more easily modifiable

  20. Phase difference between calcification and organic matrix formation in the diurnal growth of otoliths in rainbow trout, Salmo gairdneri

    International Nuclear Information System (INIS)

    Mugiya, Y.

    1987-01-01

    The relative role of calcium and organic matrix deposition in the formation of daily increments in otoliths was studied in in vitro preparations of otolith-containing sacculi of rainbow trout, Salmo gairdneri. Sacculi were incubated in a Ringer solution containing both 45 Ca and 3 H-glutamic acid for 2 hours at 6-h intervals throughout a 24-h period and then the uptake of these isotopes was determined for both otolith and saccular tissue fractions. Serum calcium and sodium concentrations were also analyzed for diurnal variations. Serum calcium concentrations varied diurnally by 8% in a single phasic pattern, reaching a peak at dusk (1600 h) and a nadir at night (2200 h), while sodium concentrations remained almost constant throughout a 24-h period. Diurnal variation in the otolith's uptake of calcium and glutamic acid showed discrete, antiphasic cycles. The rate of calcium uptake varied in a pattern closely resembling that of serum calcium (the peak at 1600 h and the nadir at 2200 h); glutamic acid uptake remained almost constant during the daytime and peaked at night (2200 h). The results indicate that in rainbow trout daily increments of otoliths are formed by the antiphasic deposition of calcium and organic matrix

  1. The global surface composition of 67P/Churyumov-Gerasimenko nucleus by Rosetta/VIRTIS. II) Diurnal and seasonal variability

    Science.gov (United States)

    Ciarniello, M.; Raponi, A.; Capaccioni, F.; Filacchione, G.; Tosi, F.; De Sanctis, M. C.; Kappel, D.; Rousseau, B.; Arnold, G.; Capria, M. T.; Barucci, M. A.; Quirico, E.; Longobardo, A.; Kuehrt, E.; Mottola, S.; Erard, S.; Bockelée-Morvan, D.; Leyrat, C.; Migliorini, A.; Zinzi, A.; Palomba, E.; Schmitt, B.; Piccioni, G.; Cerroni, P.; Ip, W.-H.; Rinaldi, G.; Salatti, M.

    2016-11-01

    VIRTIS-M observations of the nucleus of comet 67P/Churyumov-Gerasimenko acquired from 2014 August to 2015 May have been analysed to investigate surface temporal variability at both seasonal and diurnal scales. The measured reflectance spectra are studied by means of comet spectral indicators (CSI) such as slopes in the visible and infrared ranges, and 3.2 μm band area and band centre. CSI maps derived from data acquired at different heliocentric distances (from 3.62 to 1.72 au) along the inbound leg of the comet's orbit are used to infer surface water ice abundance. We measure a global scale enrichment of water ice from 2014 August to 2015 May across the body of the comet, along with variability at small spatial scale, possibly related with the local insolation conditions. Analysis of water ice diurnal variability is performed on 2014 August observations. Water ice appears at the border of receding shadows in the neck of the comet (Hapi), sublimating in less than 1 h, after exposure to sunlight. As similar variability is not observed in other regions of the comet, we interpreted this as the expression of a diurnal cycle of sublimation and re-condensation of water ice, triggered by sudden shadowing produced on the neck by the body and the head of the nucleus.

  2. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  3. Modeling the diurnal variability of agricultural ammonia in Bakersfield, California, during the CalNex campaign

    Science.gov (United States)

    Lonsdale, Chantelle R.; Hegarty, Jennifer D.; Cady-Pereira, Karen E.; Alvarado, Matthew J.; Henze, Daven K.; Turner, Matthew D.; Capps, Shannon L.; Nowak, John B.; Neuman, J. Andy; Middlebrook, Ann M.; Bahreini, Roya; Murphy, Jennifer G.; Markovic, Milos Z.; VandenBoer, Trevor C.; Russell, Lynn M.; Scarino, Amy Jo

    2017-02-01

    NH3 retrievals from the NASA Tropospheric Emission Spectrometer (TES), as well as surface and aircraft observations of NH3(g) and submicron NH4(p), are used to evaluate modeled concentrations of NH3(g) and NH4(p) from the Community Multiscale Air Quality (CMAQ) model in the San Joaquin Valley (SJV) during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. We find that simulations of NH3 driven with the California Air Resources Board (CARB) emission inventory are qualitatively and spatially consistent with TES satellite observations, with a correlation coefficient (r2) of 0.64. However, the surface observations at Bakersfield indicate a diurnal cycle in the model bias, with CMAQ overestimating surface NH3 at night and underestimating it during the day. The surface, satellite, and aircraft observations all suggest that daytime NH3 emissions in the CARB inventory are underestimated by at least a factor of 2, while the nighttime overestimate of NH3(g) is likely due to a combination of overestimated NH3 emissions and underestimated deposition.Running CMAQ v5.0.2 with the bi-directional NH3 scheme reduces NH3 concentrations at night and increases them during the day. This reduces the model bias when compared to the surface and satellite observations, but the increased concentrations aloft significantly increase the bias relative to the aircraft observations. We attempt to further reduce model bias by using the surface observations at Bakersfield to derive an empirical diurnal cycle of NH3 emissions in the SJV, in which nighttime and midday emissions differ by about a factor of 4.5. Running CMAQv5.0.2 with a bi-directional NH3 scheme together with this emissions diurnal profile further reduces model bias relative to the surface observations. Comparison of these simulations with the vertical profile retrieved by TES shows little bias except for the lowest retrieved level, but the model bias relative to flight data aloft increases

  4. Does river restoration affect diurnal and seasonal changes to surface water quality? A study along the Thur River, Switzerland

    International Nuclear Information System (INIS)

    Chittoor Viswanathan, Vidhya; Molson, John; Schirmer, Mario

    2015-01-01

    Changes in river water quality were investigated along the lower reach of the Thur River, Switzerland, following river restoration and a summer storm event. River restoration and hydrological storm events can each cause dramatic changes to water quality by affecting various bio-geochemical processes in the river, but have to date not been well documented, especially in combination. Evaluating the success of river restoration is often restricted in large catchments due to a lack of high frequency water quality data, which are needed for process understanding. These challenges were addressed in this study by measuring water quality parameters including dissolved oxygen (DO), temperature, pH, electrical conductivity (EC), nitrate and dissolved organic carbon (DOC) with a high temporal frequency (15 min–1 h) over selected time scales. In addition, the stable isotopes of water (δD and δ 18 O-H 2 O) as well as those of nitrate (δ 15 N-NO 3 − and δ 18 O-NO 3 − ) were measured to follow changes in water quality in response to the hydrological changes in the river. To compare the spatial distribution of pre- and post-restoration water quality, the sampling stations were chosen upstream and downstream of the restored section. The diurnal and seasonal changes were monitored by conducting 24-hour campaigns in three seasons (winter, summer and autumn) in 2012 and 2013. The amplitude of the diurnal changes of the various observed parameters showed significant seasonal and spatial variability. Biological processes — mainly photosynthesis and respiration — were found to be the major drivers of these diurnal cycles. During low flow in autumn, a reduction of nitrate (attributed to assimilation by autotrophs) in the pre-dawn period and a production of DOC during the daytime (attributed to photosynthesis) were observed downstream of the restored site. Further, a summer storm event was found to override the influence of these biological processes that control the diurnal

  5. Does river restoration affect diurnal and seasonal changes to surface water quality? A study along the Thur River, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Chittoor Viswanathan, Vidhya [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Université de Neuchâtel, Centre d' Hydrogéologie et de Géothermie (CHYN), Rue Emile-Argand 11, CH-2000 Neuchâtel (Switzerland); Molson, John [Université Laval, Département de Géologie et Génie Géologique, Québec City, Québec (Canada); Schirmer, Mario [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Université de Neuchâtel, Centre d' Hydrogéologie et de Géothermie (CHYN), Rue Emile-Argand 11, CH-2000 Neuchâtel (Switzerland)

    2015-11-01

    Changes in river water quality were investigated along the lower reach of the Thur River, Switzerland, following river restoration and a summer storm event. River restoration and hydrological storm events can each cause dramatic changes to water quality by affecting various bio-geochemical processes in the river, but have to date not been well documented, especially in combination. Evaluating the success of river restoration is often restricted in large catchments due to a lack of high frequency water quality data, which are needed for process understanding. These challenges were addressed in this study by measuring water quality parameters including dissolved oxygen (DO), temperature, pH, electrical conductivity (EC), nitrate and dissolved organic carbon (DOC) with a high temporal frequency (15 min–1 h) over selected time scales. In addition, the stable isotopes of water (δD and δ{sup 18}O-H{sub 2}O) as well as those of nitrate (δ{sup 15}N-NO{sub 3}{sup −} and δ{sup 18}O-NO{sub 3}{sup −}) were measured to follow changes in water quality in response to the hydrological changes in the river. To compare the spatial distribution of pre- and post-restoration water quality, the sampling stations were chosen upstream and downstream of the restored section. The diurnal and seasonal changes were monitored by conducting 24-hour campaigns in three seasons (winter, summer and autumn) in 2012 and 2013. The amplitude of the diurnal changes of the various observed parameters showed significant seasonal and spatial variability. Biological processes — mainly photosynthesis and respiration — were found to be the major drivers of these diurnal cycles. During low flow in autumn, a reduction of nitrate (attributed to assimilation by autotrophs) in the pre-dawn period and a production of DOC during the daytime (attributed to photosynthesis) were observed downstream of the restored site. Further, a summer storm event was found to override the influence of these biological

  6. Daily and circadian rhythms of neurotransmitters and related compounds in the hypothalamic suprachiasmatic nuclei of a diurnal vertebrate.

    Science.gov (United States)

    Magnone, Maria Chiara; Bertolucci, Cristiano; Piazza, Francesca; Foà, Augusto

    2003-05-23

    By using immunocytochemistry we tested whether neurotransmitters, and enzymes specific to neurotransmitters synthesis are rhythmically expressed in the suprachiasmatic nuclei of the hypothalamus of Ruin lizards Podarcis sicula either kept in light-dark cycles or constant darkness. Within the suprachiasmatic nuclei, prominent 24 h rhythms under 12:12 light-dark cycles were found for vasoactive intestinal polypeptide (VIP) and for tyrosine hydroxylase (TH). Peaks of both VIP and TH fell in the light phase of the cycle. Rhythmic expression of TH persisted under constant temperature and darkness, demonstrating the existence of circadian rhythms of TH in the suprachiasmatic nuclei. No rhythmic expression of neurotransmitters and related compounds was found in the periventricular nuclei, the supraoptic nuclei, and the rest of the hypothalamus. Our data are the first demonstration of rhythmic expression of neurotransmitters and related compounds in the suprachiasmatic nuclei of a non-mammalian vertebrate. The demonstration of a diurnal peak of VIP in a diurnal reptile-vs. nocturnal peak of VIP typical of nocturnal mammals-provides new information for comparative studies on the circadian physiology of the suprachiasmatic nuclei across vertebrate classes and their adaptation strategies to different temporal niches.

  7. Using the Atmospheric Radiation Measurement (ARM) Datasets to Evaluate Climate Models in Simulating Diurnal and Seasonal Variations of Tropical Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Burleyson, Casey D. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Ma, Po-Lun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Fast, Jerome D. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Rasch, Philip J. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington

    2018-04-01

    We use the long-term Atmospheric Radiation Measurement (ARM) datasets collected at the three Tropical Western Pacific (TWP) sites as a tropical testbed to evaluate the ability of the Community Atmosphere Model (CAM5) to simulate the various types of clouds, their seasonal and diurnal variations, and their impact on surface radiation. We conducted a series of CAM5 simulations at various horizontal grid spacing (around 2°, 1°, 0.5°, and 0.25°) with meteorological constraints from reanalysis. Model biases in the seasonal cycle of cloudiness are found to be weakly dependent on model resolution. Positive biases (up to 20%) in the annual mean total cloud fraction appear mostly in stratiform ice clouds. Higher-resolution simulations do reduce the positive bias in the frequency of ice clouds, but they inadvertently increase the negative biases in convective clouds and low-level liquid clouds, leading to a positive bias in annual mean shortwave fluxes at the sites, as high as 65 W m-2 in the 0.25° simulation. Such resolution-dependent biases in clouds can adversely lead to biases in ambient thermodynamic properties and, in turn, feedback on clouds. Both the CAM5 model and ARM observations show distinct diurnal cycles in total, stratiform and convective cloud fractions; however, they are out-of-phase by 12 hours and the biases vary by site. Our results suggest that biases in deep convection affect the vertical distribution and diurnal cycle of stratiform clouds through the transport of vapor and/or the detrainment of liquid and ice. We also found that the modelled gridmean surface longwave fluxes are systematically larger than site measurements when the grid that the ARM sites reside in is partially covered by ocean. The modeled longwave fluxes at such sites also lack a discernable diurnal cycle because the ocean part of the grid is warmer and less sensitive to radiative heating/cooling compared to land. Higher spatial resolution is more helpful is this regard. Our

  8. Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

    International Nuclear Information System (INIS)

    Bernabei, R.; D'Angelo, S.; Di Marco, A.; Belli, P.; Cappella, F.; D'Angelo, A.; Prosperi, D.; Caracciolo, V.; Castellano, S.; Cerulli, R.; Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G.; Incicchitti, A.; Montecchia, F.; Ye, Z.P.

    2014-01-01

    The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton x year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity. (orig.)

  9. Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R.; D' Angelo, S.; Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipt. di Fisica, Rome (Italy); INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Belli, P. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Cappella, F.; D' Angelo, A.; Prosperi, D. [Universita di Roma ' ' La Sapienza' ' , Dipt. di Fisica, Rome (Italy); INFN, Sezione Roma, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Incicchitti, A. [INFN, Sezione Roma, Rome (Italy); Montecchia, F. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipt. di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Ye, Z.P. [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); University of Jing Gangshan, Jiangxi (China)

    2014-03-15

    The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton x year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity. (orig.)

  10. Multiple origin of diurnality in geckos: evidence from eye lens crystallins

    Science.gov (United States)

    Röll, Beate

    2001-05-01

    The large lizard family Gekkonidae comprises about 90 genera (1000 species). While most geckos are nocturnal, the members of about 15 genera are diurnal. All of these species are 'tertiarily' diurnal, i.e. they are descended from 'secondarily' nocturnal ancestors. They have adapted to a diurnal lifestyle in quite different ways, as can be deduced by the crystallin proteins in their lenses. Evaluation of the heterogeneous lens crystallin compositions of diurnal geckos reveals that there are at least three lineages that regained diurnality independently.

  11. Effects of light on NO3 uptake in small forested streams: diurnal and day-to-day variations

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Patrick J [ORNL

    2006-08-01

    We investigated the effects of autotrophy on short-term variations in nutrient dynamics by measuring diurnal and day-to-day variations in light level, primary productivity, and NO{sub 3}{sup -} uptake during early and late spring in 2 forested streams, the East and West Forks of Walker Branch in eastern Tennessee, USA. We predicted that diurnal and day-to-day variations in NO{sub 3}{sup -} uptake rate would be larger in the West Fork than in the East Fork in early spring because of higher rates of primary productivity resulting from a more stable substratum in the West Fork. We also predicted minimal diurnal variations in both streams in late spring after forest leaf emergence when light levels and primary productivity are uniformly low. Reach-scale rates of gross primary production (GPP) were determined using the diurnal dissolved O{sub 2} change technique, and reach-scale rates of NO{sub 3}{sup -} uptake were determined by tracer {sup 15}N-NO{sub 3}{sup -} additions. In the West Fork, significant diurnal and day-to-day variations in NO{sub 3}{sup -} uptake were related to variations in light level and primary productivity in early spring but not in late spring, consistent with our predictions. In early spring, West Fork NO{sub 3}{sup -} uptake rates were 2 to 3x higher at midday than during predawn hours and 50% higher on 2 clear days than on an overcast day several days earlier. In the East Fork, early spring rates of GPP were 4 to 5x lower than in the West Fork and diurnal and day-to-day variations in NO{sub 3}{sup -} uptake rates were <30%, considerably lower than in the West Fork. However, diurnal variations in NO{sub 3}{sup -} uptake rates were greater in late spring in the East Fork, possibly because of diurnal variation in water temperature. Our results indicate the important role of autotrophs in nutrient uptake in some forested streams, particularly during seasons when forest vegetation is dormant and light levels are relatively high. Our results also

  12. Prediction of the antidepressant response to total sleep deprivation by diurnal variation of mood.

    Science.gov (United States)

    Reinink, E; Bouhuys, N; Wirz-Justice, A; van den Hoofdakker, R

    1990-05-01

    The relationship between diurnal variation of mood and response to total sleep deprivation (TSD) was investigated in 131 depressed patients. This response was related to (1) the diurnal variation on the day before TSD as assessed by self-ratings of mood, and (2) the propensity to produce diurnal variations (the "diurnality") as assessed by the Hamilton Rating Scale for Depression. Three types of diurnality are distinguished: morning type (the propensity to feel better in the morning), evening type (the propensity to feel better in the evening), and a nondiurnal type. The results show that diurnality does predict the mood response to TSD. The direction of diurnality is decisive: patients who have the propensity to feel better in the evening benefit more from TSD than other patients.

  13. Diurnal regulation of photosynthesis in Jatropha curcas under drought during summer in a semi-arid region

    International Nuclear Information System (INIS)

    Tominaga, Jun; Inafuku, Sayuri; Coetzee, Tidimalo; Kawamitsu, Yoshinobu

    2014-01-01

    The diurnal photosynthetic responses to drought in Jatropha curcas have not been well assessed under field conditions in harsh semi-arid habitats. To illustrate this, diurnal changes in chlorophyll fluorescence and gas exchange rates were measured in field-grown Jatropha with or without a short (13 days) water recovery treatment under drought conditions during hot summer in a semi-arid. Sensitive stomatal closure coordinated with a drying atmosphere strictly limited a net CO 2 assimilation rate with a predominant morning peak, eventually turning negative during the day. Even though the risk of excess excitation energy which potentially causes photodamage increased with the extremely low capacity for CO 2 fixation, Jatropha preserved the integrity of PSII. Quantitative analysis of quenching partitioning revealed that regulated thermal energy dissipation accounted a large fraction of both instantaneous and daily absorbed energy by up to 80 and 72%, respectively, under the drought condition. Water recovery treatment more than doubled daily CO 2 uptake via mitigating diurnal stomatal closure. The regulated thermal dissipation flexibly adjusted PSII quantum efficiency to capacity of CO 2 fixation. In addition, downregulation of PSII quantum efficiency via sustained regulated thermal dissipation was observed and thought to be an additional photoprotective function. It is clear that Jatropha strongly rely upon the regulated thermal dissipation under drought condition, which must be critically important for this strict water conserving species, especially under a climate with high solar radiation loads as is seen in semi-arid regions. - Highlights: • Diurnal gas exchange and the fate of absorbed energy were assessed in Jatropha. • The dynamic stomatal closure was the predominant restriction under water stress. • The PSII integrity was preserved even under severe water stress. • The regulated thermal dissipation accounted by up to 72% of daily absorbed energy.

  14. Average diurnal variation of summer lightning over the Florida peninsula

    Science.gov (United States)

    Maier, L. M.; Krider, E. P.; Maier, M. W.

    1984-01-01

    Data derived from a large network of electric field mills are used to determine the average diurnal variation of lightning in a Florida seacoast environment. The variation at the NASA Kennedy Space Center and the Cape Canaveral Air Force Station area is compared with standard weather observations of thunder, and the variation of all discharges in this area is compared with the statistics of cloud-to-ground flashes over most of the South Florida peninsula and offshore waters. The results show average diurnal variations that are consistent with statistics of thunder start times and the times of maximum thunder frequency, but that the actual lightning tends to stop one to two hours before the recorded thunder. The variation is also consistent with previous determinations of the times of maximum rainfall and maximum rainfall rate.

  15. Diurnal variation of von Willebrand factor in plasma

    DEFF Research Database (Denmark)

    Timm, Annette; Fahrenkrug, Jan; Jørgensen, Henrik L

    2014-01-01

    thoroughly tested. OBJECTIVES: We examined whether VWF antigen and VWF activity in plasma display a diurnal profile in healthy young males, and whether such variation is related to changes in release or elimination. METHODS: Plasma from 20 healthy young males was collected at 9 time-points over 24 h (15 h......BACKGROUND: Quantitation of von Willebrand factor (VWF) in plasma is a central element in assessing von Willebrand disease (VWD). VWF activity is known to vary, which has partly been ascribed to biological and preanalytical variation. However, a possible diurnal expression of VWF has not been...... of light and 9 h of darkness); the plasma concentration of melatonin was used as an internal control to confirm the normal 24-h rhythms of the individual participants. RESULTS: The data, analyzed by rhythmometric statistics, revealed a significant variation (P = 0.02) and total amplitude of 22.6% in VWF...

  16. Seasonal and diurnal variability of Mars water-ice clouds

    Science.gov (United States)

    Christensen, Philip R.; Zurek, Richard W.; Jaramillo, L. L.

    1988-01-01

    The diurnal and seasonal behavior of cloud opacity and frequency of occurrence was studied using an atlas of cloud occurrences compiled from the Viking IRTM (Infrared Thermal Mapper) data set. It was found that in some areas the behavior of water appeared to repeat in the zonal mean. However, this interpretation is complicated by both poor coverage and the variability of dust and clouds. As a result, the extent and nature of interannual variability remains unclear.

  17. Diurnal and seasonal variations of surface water vapour density ...

    African Journals Online (AJOL)

    Diurnal and seasonal variations of surface water vapour density over some meteorological stations in Nigeria. ... Ife Journal of Science ... the three Sahelian stations, was 5.29±0.39; while during the rainy season, they were 21.72±1.22, 19.60±0.12 and 19.47±0.07 for the Southern, Midland and Northern regions respectively.

  18. The CIRCORT database: Reference ranges and seasonal changes in diurnal salivary cortisol derived from a meta-dataset comprised of 15 field studies

    Science.gov (United States)

    Miller, Robert; Stalder, Tobias; Jarczok, Marc; Almeida, David M.; Badrick, Ellena; Bartels, Meike; Boomsma, Dorret I.; Coe, Christopher L.; Dekker, Marieke C. J.; Donzella, Bonny; Fischer, Joachim E.; Gunnar, Megan R.; Kumari, Meena; Lederbogen, Florian; Oldehinkel, Albertine J.; Power, Christine; Rosmalen, Judith G.; Ryff, Carol D.; Subramanian, S V; Tiemeier, Henning; Watamura, Sarah E.; Kirschbaum, Clemens

    2016-01-01

    Diurnal salivary cortisol profiles are valuable indicators of adrenocortical functioning in epidemiological research and clinical practice. However, normative reference values derived from a large number of participants and across a wide age range are still missing. To fill this gap, data were compiled from 15 independently conducted field studies with a total of 104,623 salivary cortisol samples obtained from 18,698 unselected individuals (mean age: 48.3 years, age range: 0.5 to 98.5 years, 39% females). Besides providing a descriptive analysis of the complete dataset, we also performed mixed-effects growth curve modeling of diurnal salivary cortisol (i.e., 1 to 16 hours after awakening). Cortisol decreased significantly across the day and was influenced by both, age and sex. Intriguingly, we also found a pronounced impact of sampling season with elevated diurnal cortisol in spring and decreased levels in autumn. However, the majority of variance was accounted for by between-participant and between-study variance components. Based on these analyses, reference ranges (LC/MS-MS calibrated) for cortisol concentrations in saliva were derived for different times across the day, with more specific reference ranges generated for males and females in different age categories. This integrative summary provides important reference values on salivary cortisol to aid basic scientists and clinicians in interpreting deviations from the normal diurnal cycle. PMID:27448524

  19. Prenatal exposure to diurnal temperature variation and early childhood pneumonia.

    Science.gov (United States)

    Zeng, Ji; Lu, Chan; Deng, Qihong

    2017-04-01

    Childhood pneumonia is one of the leading single causes of mortality and morbidity in children worldwide, but its etiology still remains unclear. We investigate the association between childhood pneumonia and exposure to diurnal temperature variation (DTV) in different timing windows. We conducted a prospective cohort study of 2,598 children aged 3-6 years in Changsha, China. The lifetime prevalence of pneumonia was assessed by a questionnaire administered by the parents. Individual exposure to DTV during both prenatal and postnatal periods was estimated. Logic regression models was used to examine the association between childhood pneumonia and DTV exposure in terms of odds ratios (OR) and 95% confidence interval (CI). Lifetime prevalence of childhood pneumonia in preschool children in Changsha was high up to 38.6%. We found that childhood pneumonia was significantly associated with prenatal DTV exposure, with adjusted OR (95%CI) =1.19 (1.02-1.38), particularly during the second trimester. However, childhood pneumonia not associated with postnatal DTV exposure. Sensitivity analysis indicated that boys are more susceptible to the pneumonia risk of diurnal temperature variation than girls. We further observed that the prevalence of childhood pneumonia was decreased in recent years as DTV shrinked. Early childhood pneumonia was associated with prenatal exposure to the diurnal temperature variation (DTV) during pregnancy, particularly in the second trimester, which suggests fetal origin of childhood pneumonia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Specific diurnal EMG activity pattern observed in occlusal collapse patients: relationship between diurnal bruxism and tooth loss progression.

    Science.gov (United States)

    Kawakami, Shigehisa; Kumazaki, Yohei; Manda, Yosuke; Oki, Kazuhiro; Minagi, Shogo

    2014-01-01

    The role of parafunctional masticatory muscle activity in tooth loss has not been fully clarified. This study aimed to reveal the characteristic activity of masseter muscles in bite collapse patients while awake and asleep. Six progressive bite collapse patients (PBC group), six age- and gender-matched control subjects (MC group), and six young control subjects (YC group) were enrolled. Electromyograms (EMG) of the masseter muscles were continuously recorded with an ambulatory EMG recorder while patients were awake and asleep. Diurnal and nocturnal parafunctional EMG activity was classified as phasic, tonic, or mixed using an EMG threshold of 20% maximal voluntary clenching. Highly extended diurnal phasic activity was observed only in the PBC group. The three groups had significantly different mean diurnal phasic episodes per hour, with 13.29±7.18 per hour in the PBC group, 0.95±0.97 per hour in the MC group, and 0.87±0.98 per hour in the YC group (pstability.

  1. Diurnal Profiles of Melatonin Synthesis-Related Indoles, Catecholamines and Their Metabolites in the Duck Pineal Organ

    Directory of Open Access Journals (Sweden)

    Bogdan Lewczuk

    2014-07-01

    Full Text Available This study characterizes the diurnal profiles of ten melatonin synthesis-related indoles, the quantitative relations between these compounds, and daily variations in the contents of catecholamines and their metabolites in the domestic duck pineal organ. Fourteen-week-old birds, which were reared under a 12L:12D cycle, were killed at two-hour intervals. The indole contents were measured using HPLC with fluorescence detection, whereas the levels of catecholamines and their metabolites were measured using HPLC with electrochemical detection. All indole contents, except for tryptophan, showed significant diurnal variations. The 5-hydroxytryptophan level was approximately two-fold higher during the scotophase than during the photophase. The serotonin content increased during the first half of the photophase, remained elevated for approximately 10 h and then rapidly decreased in the middle of the scotophase. N-acetylserotonin showed the most prominent changes, with a more than 15-fold increase at night. The melatonin cycle demonstrated only an approximately 5-fold difference between the peak and nadir. The 5-methoxytryptamine content was markedly elevated during the scotophase. The 5-hydroxyindole acetic acid, 5-hydroxytryptophol, 5-methoxyindole acetic acid and 5-methoxytryptophol profiles were analogous to the serotonin rhythm. The norepinephrine and dopamine contents showed no significant changes. The DOPA, DOPAC and homovanillic acid levels were higher during the scotophase than during the photophase. Vanillylmandelic acid showed the opposite rhythm, with an elevated level during the daytime.

  2. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  3. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    International Nuclear Information System (INIS)

    Weiland, N.G.; Wise, P.M.

    1987-01-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with [ 3 H]prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland

  4. Estrogen alters the diurnal rhythm of alpha 1-adrenergic receptor densities in selected brain regions

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, N.G.; Wise, P.M.

    1987-11-01

    Norepinephrine regulates the proestrous and estradiol-induced LH surge by binding to alpha 1-adrenergic receptors. The density of alpha 1-receptors may be regulated by estradiol, photoperiod, and noradrenergic neuronal activity. We wished to determine whether alpha 1-receptors exhibit a diurnal rhythm in ovariectomized and/or estradiol-treated female rats, whether estradiol regulates alpha 1-receptors in those areas of brain involved with LH secretion and/or sexual behavior, and whether the concentrations of alpha-receptors vary inversely relative to previously reported norepinephrine turnover patterns. Young female rats, maintained on a 14:10 light-dark cycle were ovariectomized. One week later, half of them were outfitted sc with Silastic capsules containing estradiol. Groups of animals were decapitated 2 days later at 0300, 1000, 1300, 1500, 1800, and 2300 h. Brains were removed, frozen, and sectioned at 20 micron. Sections were incubated with (/sup 3/H)prazosin in Tris-HCl buffer, washed, dried, and exposed to LKB Ultrofilm. The densities of alpha 1-receptors were quantitated using a computerized image analysis system. In ovariectomized rats, the density of alpha 1-receptors exhibited a diurnal rhythm in the suprachiasmatic nucleus (SCN), medial preoptic nucleus (MPN), and pineal gland. In SCN and MPN, receptor concentrations were lowest during the middle of the day and rose to peak levels at 1800 h. In the pineal gland, the density of alpha 1-receptors was lowest at middark phase, rose to peak levels before lights on, and remained elevated during the day. Estradiol suppressed the density of alpha 1 binding sites in the SCN, MPN, median eminence, ventromedial nucleus, and the pineal gland but had no effect on the lateral septum. Estrogen treatment altered the rhythm of receptor densities in MPN, median eminence, and the pineal gland.

  5. Diurnal Preference Predicts Phase Differences in Expression of Human Peripheral Circadian Clock Genes.

    Science.gov (United States)

    Ferrante, Andrew; Gellerman, David; Ay, Ahmet; Woods, Kerri Pruitt; Filipowicz, Allan Michael; Jain, Kriti; Bearden, Neil; Ingram, Krista Kenyon

    2015-06-05

    Circadian rhythms play an integral role in human behavior, physiology and health. Individual differences in daily rhythms (chronotypes) can affect individual sleep-wake cycles, activity patterns and behavioral choices. Diurnal preference, the tendency towards morningness or eveningness among individuals, has been associated with interpersonal variation in circadian clock-related output measures, including body temperature, melatonin levels and clock gene mRNA in blood, oral mucosa, and dermal fibroblast cell cultures. Here we report gene expression data from two principal clock genes sampled from hair follicle cells, a peripheral circadian clock. Hair follicle cells from fourteen individuals of extreme morning or evening chronotype were sampled at three time points. RNA was extracted and quantitative PCR assays were used to measure mRNA expression patterns of two clock genes, Per3 and Nr1d2. We found significant differences in clock gene expression over time between chronotype groups, independent of gender or age of participants. Extreme evening chronotypes have a delay in phase of circadian clock gene oscillation relative to extreme morning types. Variation in the molecular clockwork of chronotype groups represents nearly three-hour phase differences (Per3: 2.61 hours; Nr1d2: 3.08 hours, both: 2.86) in circadian oscillations of these clock genes. The measurement of gene expression from hair follicles at three time points allows for a direct, efficient method of estimating phase shifts of a peripheral circadian clock in real-life conditions. The robust phase differences in temporal expression of clock genes associated with diurnal preferences provide the framework for further studies of the molecular mechanisms and gene-by-environment interactions underlying chronotype-specific behavioral phenomena, including social jetlag.

  6. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  7. Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2 to 70°N, and the GSWM tidal model

    Science.gov (United States)

    Manson, A.; Meek, C.; Hagan, M.; Hall, C.; Hocking, W.; MacDougall, J.; Franke, S.; Riggin, D.; Fritts, D.; Vincent, R.; Burrage, M.

    1999-07-01

    Continuous observations of the wind field have been made by six Medium Frequency Radars (MFRs), located between the equator and high northern latitudes: Christmas Islands (2°N), Hawaii (22°N), Urbana (40°N), London (43°N), Saskatoon (52°N) and Tromsø (70°N). Data have been sought for the time interval 1990-1997, and typically 5 years of data have become available from each station, to demonstrate the level of annual consistency and variability. Common harmonic analysis is applied so that the monthly amplitudes and phases of the semi-diurnal (SD) and diurnal (D) wind oscillations are available in the height range of (typically) 75-95 km in the upper Middle Atmosphere. Comparisons are made with tides from the Global Scale Wave Model (GSWM), which are available for 3-month seasons. The emphasis is upon the monthly climatologies at each location based upon comparisons of profiles, and also latitudinal plots of amplitudes and phases at particular heights. For the diurnal tide, the agreement between observations and model is now quite excellent with modelled values frequently lying within the range of yearly values. Both observations and model demonstrate strong seasonal changes. This result is a striking improvement over the comparisons of 1989 (JATP, Special issue). In particular, the phases and phase-gradients for the non-winter months at mid- to high-latitudes are now in excellent agreement. Some of the low latitude discrepancies are attributed to the existence of non-migrating tidal components associated with tropospheric latent heat release. For the semi-diurnal tide, the observed strong transitions between clear solstitial states are less well captured by the model. There is little evidence for improvement over the promising comparisons of 1989. In particular, the late-summer/autumnal tidal maximum of mid-latitudes is observed to be larger, and with strong monthly variability. Also the summer modelled tide has unobserved short (20 km) wavelengths at high

  8. Educational Business Cycles

    DEFF Research Database (Denmark)

    Tepe, Markus; Vanhuysse, Pieter

    2009-01-01

    Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...... teacher employment patterns at the state level in Germany and find strong evidence of cycling mechanisms, in the form of electioneering and honeymooning. Against a backdrop of a continuously shrinking total teachers' pool, German state-level incumbents accelerate the hiring of new teachers during election...... periods and partly reverse this during politically safer points in the electoral cycle. Cycles are mediated by issue salience: heightened attention to German public schooling after the notorious PISA-2000 tests further strengthens the manipulation of new teacher hiring for electoral purposes....

  9. Educational Business Cycles

    DEFF Research Database (Denmark)

    Tepe, Markus; Vanhuysse, Pieter

    Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...... teacher employment patterns at the state level in Germany and find strong evidence of cycling mechanisms, in the form of electioneering and honeymooning. Against a backdrop of a continuously shrinking total teachers' pool, German state-level incumbents accelerate the hiring of new teachers during election...... periods and partly reverse this during politically safer points in the electoral cycle. Cycles are mediated by issue salience: heightened attention to German public schooling after the notorious PISA-2000 tests further strengthens the manipulation of new teacher hiring for electoral purposes....

  10. Diurnal expression of proteins in the retina of the blind cone-rod homeobox (Crx-/- ) mouse and the 129/Sv mouse: a proteomic study.

    Science.gov (United States)

    Møller, Morten; Rath, Martin Fredensborg; Ludvigsen, Maja; Honoré, Bent; Vorum, Henrik

    2017-11-01

    The vertebrate retina contains a circadian clock participating in adaptations to day and night vision. This peripheral clock is independent of the master clock in the suprachiasmatic nucleus (SCN). The retinal clock is located in several cell types, including the photoreceptors. To investigate the role of the circadian clock of the photoreceptor cells in regulation of retinal protein rhythms, we analysed diurnal protein expression in the photoreceptor-deficient cone-rod homeobox knockout mouse (Crx -/- ) and the 129/Sv mouse. 2D gels were made from retinal homogenates of 129/Sv and Crx -/- mice killed at midday and midnight. Stained gels were analysed by use of PDQuest 2D gel analysis software. After trypsin digestion of differential expressed spots, the proteins were identified by LC-MS/MS using a nano-liquid chromatograph connected to a Q-TOF Premier mass spectrometer. These data were used to search the SWISS-PROT database. Both the retinae of the control and the Crx -/- mice exhibited diurnal proteins rhythms. As expected, proteins involved in phototransduction were not detected in the Crx -/- mouse; in this phenotype, however, proteins from spots showing diurnal rhythms were specifically identified as enzymes involved in glucose metabolism, Krebs cycle, and mitochondrial enzymes. Data are available via ProteomeXchange with identifier PXD005556. We show diurnal protein rhythms in the retina of a mouse lacking the rods and cones. The diurnal protein rhythms in this genotype, lacking the circadian clock of the photoreceptors, might be caused by a circadian clock in other retinal cell types or a direct light input to the retina. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  11. Long term change of diurnal cycle in surface air temperature over Tokyo metropolitan area

    Science.gov (United States)

    Hara, M.; Shimada, T.

    2017-12-01

    Tokyo Metropolitan area (i.e. southern part of Kanto district) is known for one of the hottest areas in summer in Japan. Especially in Saitama prefecture (north of Tokyo), the daily maximum surface air temperature (SAT) at screen height sometimes reached in 40 C. In the last decade, the summer heat environment in Japan is getting worse, and the number of emergency transportations due to heat stroke is rapidly increasing. In this study, we evaluate regional climate change due to some factors, such as land use / land cover changes. To evaluate the regional climate change, we performed analysis of observed data and a series of past climate simulations using the Weather Research and Forecasting (WRF) model with high horizontal resolution, including an urban canopy sub-model.

  12. Atmospheric stability in CFD &NDASH; Representation of the diurnal cycle in the atmospheric boundary layer

    DEFF Research Database (Denmark)

    Koblitz, Tilman; Bechmann, Andreas; Sogachev, Andrey

    2012-01-01

    ), for example the Coriolis force, buoyancy forces and heat transport, are mostly ignored in state-of-the-art CFD models. In order to decrease the uncertainty of wind resource assessment, especially in complex terrain, the effect of thermal stratification on the ABL should be included in such models. The present...

  13. Atmospheric leakage and condensate production in NASA's biomass production chamber. Effect of diurnal temperature cycles

    Science.gov (United States)

    Wheeler, Raymond M.; Drese, John H.; Sager, John C.

    1991-01-01

    A series of tests were conducted to monitor atmospheric leakage rate and condensate production in NASA's Biomass Production Chamber (BPC). Water was circulated through the 64 plant culture trays inside the chamber during the tests but no plants were present. Environmental conditions were set to a 12-hr photoperiod with either a matching 26 C (light)/20 C (dark) thermoperiod, or a constant 23 C temperature. Leakage, as determined by carbon dioxide decay rates, averaged about 9.8 percent for the 26 C/20 C regime and 7.3 percent for the constant 23 C regime. Increasing the temperature from 20 C to 26 C caused a temporary increase in pressure (up to 0.5 kPa) relative to ambient, while decreasing the temperature caused a temporary decrease in pressure of similar magnitude. Little pressure change was observed during transition between 23 C (light) and 23 C (dark). The lack of large pressure events under isothermal conditions may explain the lower leakage rate observed. When only the plant support inserts were placed in the culture trays, condensate production averaged about 37 liters per day. Placing acrylic germination covers over the tops of culture trays reduced condensate production to about 7 liters per day. During both tests, condensate production from the lower air handling system was 60 to 70 percent greater than from the upper system, suggesting imbalances exist in chilled and hot water flows for the two air handling systems. Results indicate that atmospheric leakage rates are sufficiently low to measure CO2 exchange rates by plants and the accumulation of certain volatile contaminants (e.g., ethylene). Control system changes are recommended in order to balance operational differences (e.g., humidity and temperature) between the two halves of the chamber.

  14. New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations

    NARCIS (Netherlands)

    Andela, N.; Kaiser, J.; van der Werf, G.R.

    2015-01-01

    Accurate near real time fire emissions estimates are required for air quality forecasts. To date, most approaches are based on satellite-derived estimates of fire radiative power (FRP), which can be converted to fire radiative energy (FRE) which is directly related to fire emissions. Uncertainties

  15. Observations and modeling of the diurnal SST cycle in the North and Baltic Seas

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, J.L.

    2013-01-01

    do not exceed 0.25 K, with a maximum standard deviation of 0.76 and a 0.45 correlation. When random noise is added to the models, their ability to reproduce the statistical properties of the SEVIRI observations improves. The correlation between the observed and modeled anomalies and different...

  16. Seasonal Variation of Diurnal Cycle of Rainfall in the Eastern Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Pednekar, S.; Katsumata, M.; Antony, M.K.; Kuroda, Y.; Unnikrishnan, A.S.

    it was seen that majority of the rain events (> 60%) were less than 3 hours duration throughout the study period. The longer duration rainfall events (i.e rain events greater than 6 hour duration) contributed significantly to Spring 2002 (20% of the total...

  17. Nutrient cycling in a strongly acidified mesotrophic lake

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Jiří; Brzáková, Martina; Hejzlar, Josef; Nedoma, Jiří; Porcal, Petr; Vrba, Jaroslav

    2004-01-01

    Roč. 49, č. 4 (2004), s. 1202-1213 ISSN 0024-3590 R&D Projects: GA ČR(CZ) GA206/00/0063; GA ČR(CZ) GA206/03/1583 Institutional research plan: CEZ:AV0Z6017912 Keywords : acidification * nutrients * water chemistry Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.024, year: 2004

  18. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  19. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  20. Diurnality as an energy-saving strategy: energetic consequences of temporal niche switching in small mammals

    OpenAIRE

    van der Vinne, V.; Gorter, J.A.; Riede, S.J.; Hut, R.A.

    2015-01-01

    Endogenous daily (circadian) rhythms allow organisms to anticipate daily changes in the environment. Most mammals are specialized to be active during the night (nocturnal) or day (diurnal). However, typically nocturnal mammals become diurnal when energetically challenged by cold or hunger. The circadian thermo-energetics (CTE) hypothesis predicts that diurnal activity patterns reduce daily energy expenditure (DEE) compared with nocturnal activity patterns. Here, we tested the CTE hypothesis b...

  1. Modeling the diurnal tide with dissipation derived from UARS/HRDI measurements

    Directory of Open Access Journals (Sweden)

    M. A. Geller

    1997-09-01

    Full Text Available This paper uses dissipation values derived from UARS/HRDI observations in a recently published diurnal-tide model. These model structures compare quite well with the UARS/HRDI observations with respect to the annual variation of the diurnal tidal amplitudes and the size of the amplitudes themselves. It is suggested that the annual variation of atmospheric dissipation in the mesosphere-lower thermosphere is a major controlling factor in determining the annual variation of the diurnal tide.

  2. Diurnal variations in the UV albedo of arctic snow

    Directory of Open Access Journals (Sweden)

    O. Meinander

    2008-11-01

    Full Text Available The relevance of snow for climate studies is based on its physical properties, such as high surface reflectivity. Surface ultraviolet (UV albedo is an essential parameter for various applications based on radiative transfer modeling. Here, new continuous measurements of the local UV albedo of natural Arctic snow were made at Sodankylä (67°22'N, 26°39'E, 179 m a.s.l. during the spring of 2007. The data were logged at 1-min intervals. The accumulation of snow was up to 68 cm. The surface layer thickness varied from 0.5 to 35 cm with the snow grain size between 0.2 and 2.5 mm. The midday erythemally weighted UV albedo ranged from 0.6 to 0.8 in the accumulation period, and from 0.5 to 0.7 during melting. During the snow melt period, under cases of an almost clear sky and variable cloudiness, an unexpected diurnal decrease of 0.05 in albedo soon after midday, and recovery thereafter, was detected. This diurnal decrease in albedo was found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. Independent UV albedo results with two different types of instruments confirm these findings. The measured temperature of the snow surface was below 0°C on the following mornings. Hence, the reversible diurnal change, evident for ~1–2 h, could be explained by the daily metamorphosis of the surface of the snowpack, in which the temperature of the surface increases, melting some of the snow to liquid water, after which the surface freezes again.

  3. Moored surface buoy observations of the diurnal warm layer

    KAUST Repository

    Prytherch, J.

    2013-09-01

    An extensive data set is used to examine the dynamics of diurnal warming in the upper ocean. The data set comprises more than 4700 days of measurements at five sites in the tropics and subtropics, obtained from surface moorings equipped to make comprehensive meteorological, incoming solar and infrared radiation, and high-resolution subsurface temperature (and, in some cases, velocity) measurements. The observations, which include surface warmings of up to 3.4°C, are compared with a selection of existing models of the diurnal warm layer (DWL). A simple one-layer physical model is shown to give a reasonable estimate of both the magnitude of diurnal surface warming (model-observation correlation 0.88) and the structure and temporal evolution of the DWL. Novel observations of velocity shear obtained during 346 days at one site, incorporating high-resolution (1 m) upper ocean (5-15 m) acoustic Doppler current profile measurements, are also shown to be in reasonable agreement with estimates from the physical model (daily maximum shear model-observation correlation 0.77). Physics-based improvements to the one-layer model (incorporation of rotation and freshwater terms) are discussed, though they do not provide significant improvements against the observations reported here. The simplicity and limitations of the physical model are used to discuss DWL dynamics. The physical model is shown to give better model performance under the range of forcing conditions experienced across the five sites than the more empirical models. ©2013. American Geophysical Union. All Rights Reserved.

  4. Diurnal alterations in circadian genes and peptides in major depressive disorder before and after escitalopram treatment.

    Science.gov (United States)

    Li, Su-Xia; Liu, Li-Jing; Xu, Ling-Zhi; Gao, Lei; Wang, Xin-Fu; Zhang, Jing-Tao; Lu, Lin

    2013-11-01

    Strong links exist between circadian disturbances and some of the most characteristic symptoms of clinical major depressive disorder (MDD). However, changes in the expression of clock genes or neuropeptides related to the regulation of circadian rhythm that may influence the susceptibility to recurrence after antidepressant treatment in MDD have not been investigated. Blood samples were collected at 4h intervals for 24h from 12 male healthy controls and 12 male MDD patients before and after treatment with escitalopram for 8 weeks. The outcome measures included the relative expression of clock gene mRNA (PERIOD1, PERIOD2, PERIOD3, CRY1, BMAL1, NPAS2, and GSK-3β), and the levels of serum melatonin, vasoactive intestinal polypeptide (VIP), cortisol, adrenocorticotropic hormone (ACTH), insulin-like growth factor-1 (IGF-1), and growth hormone (GH). Compared with healthy controls, MDD patients showed disruptions in the diurnal rhythms of the expression of PERIOD1, PERIOD2, CRY1, BMAL1, NPAS2, and GSK-3β and disruptions in the diurnal rhythms of the release of melatonin, VIP, cortisol, ACTH, IGF-1, and GH. Several of these disruptions (i.e., PER1, CRY1, melatonin, VIP, cortisol, ACTH, and IGF-1) persisted 8 weeks after escitalopram treatment, similar to the increase in the 24h levels of VIP and decreases in the 24h levels of cortisol and ACTH. These persistent neurobiological changes may play a role in MDD symptoms that are thought to contribute to the vulnerability to recurrence and long-term maintenance therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Biodegradation of Toluene Under Seasonal and Diurnal Fluctuations of Soil-Water Temperature.

    KAUST Repository

    Yadav, Brijesh K

    2012-05-12

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of varying soil-water temperature on biodegradation of toluene under aerobic conditions. To see the seasonal impact of temperature, three sets of batch experiments were conducted at three different constant temperatures: 10°C, 21°C, and 30°C. These conditions were considered to represent (1) winter, (2) spring and/or autumn, and (3) summer seasons, respectively, at many polluted sites. Three additional sets of batch experiments were performed under fluctuating soil-water temperature cases (21<>10°C, 30<>21°C, and 10<>30°C) to mimic the day-night temperature patterns expected during the year. The batches were put at two different temperatures alternatively to represent the day (high-temperature) and night (low-temperature) times. The results of constant- and fluctuating-temperature experiments show that toluene degradation is strongly dependent on soil-water temperature level. An almost two-fold increase in toluene degradation time was observed for every 10°C decrease in temperature for constant-temperature cases. Under fluctuating-temperature conditions, toluene degraders were able to overcome the temperature stress and continued thriving during all considered weather scenarios. However, a slightly longer time was taken compared to the corresponding time at daily mean temperature conditions. The findings of this study are directly useful for bioremediation of hydrocarbon-polluted sites having significant diurnal and seasonal variations of soil-water temperature.

  6. Diurnal Variation of Radon Concentration in the Postojna Cave

    International Nuclear Information System (INIS)

    Gregoric, A.; Vaupotic, J.

    2011-01-01

    Postojna Cave, with 20 km of galleries, is the longest known cave system and also the largest of about 20 show caves in Slovenia and one of the most visited show caves in the world. It is well known that high concentrations of radon are common in karstic caves, although quantities of uranium (238U) in limestone are rather low. The reason for this is low natural ventilation of the underground cavities. Tectonic faults constitute an additional source of radon. Variations of radon concentration in cave air arise from a balance of the emission from cave surfaces and drip waters, decay in cave air, and exchange with the outside atmosphere. Because of its elevated radon concentrations, Postojna Cave has been under permanent radon survey since 1995. The influence of meteorological conditions on the radon levels and their temporal variations depends mostly on the shape of the cave, and the number and directions of cracks, corridors and fissures connecting the cave rooms with the outside atmosphere. The driving force for air movement in horizontal caves, and thus the inflow of fresh air and release of the cave air to the atmosphere, is the temperature difference between the cave air and outdoors, which causes seasonal pattern of radon concentration in the cave with high levels in summer and low in winter. However, on a daily scale different behaviour of radon can be observed at different locations in the cave. In this paper diurnal variation of radon concentration at two locations is presented and discussed. Postojna Cave is a horizontal cave with a stable yearly temperature around 10 degrees of @C. Continuous measurements of radon concentration were carried out from 2005 to 2010 at two locations along the guided tourist trail. Radon concentration was measured with Radim 5 WP monitors (SMM Company, Prague, Czech Republic) with sampling frequency once an hour. The evaluation of five-year radon monitoring at two sites in the Postojna Cave reveals significant diurnal and

  7. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  8. Cycles in fossil diversity

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, Robert A.; Muller, Richard A.

    2004-10-20

    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

  9. Diurnal variation of atmospheric water vapor at Gale crater: Analysis from ground-based measurements

    Science.gov (United States)

    Martinez, German; McConnochie, Timothy; Renno, Nilton; Meslin, Pierre-Yves; Fischer, Erik; Vicente-Retortillo, Alvaro; Borlina, Caue; Kemppinen, Osku; Genzer, Maria; Harri, Ari-Matti; de la Torre-Juárez, Manuel; Zorzano, Mari-Paz; Martin-Torres, Javier; Bridges, Nathan; Maurice, Sylvestre; Gasnault, Olivier; Gomez-Elvira, Javier; Wiens, Roger

    2016-04-01

    We analyze measurements obtained by Curiosity's Rover Environmental Monitoring Station (REMS) and ChemCam (CCAM) instruments to shed light on the hydrological cycle at Gale crater. In particular, we use nighttime REMS measurements taken when the atmospheric volume mixing ratio (VMR) and its uncertainty are the lowest (between 05:00 and 06:00 LTST) [1], and daytime CCAM passive sky measurements taken when the VMR is expected to be the highest (between 10:00 and 14:00 LTST) [2]. VMR is calculated from simultaneous REMS measurements of pressure (P), temperature (T) and relative humidity (RH) at 1.6 m (VMR is defined as RH×es(T)/P , where es is the saturation water vapor pressure over ice). The REMS relative humidity sensor has recently been recalibrated (June 2015), providing RH values slightly lower than those in the previous calibration (Dec 2014). The full diurnal cycle of VMR cannot be analyzed using only REMS data because the uncertainty in daytime VMR derived from REMS measurements is extremely high. Daytime VMR is inferred by fitting the output of a multiple-scattering discrete-ordinates radiative transfer model to CCAM passive sky observations [3]. CCAM makes these observations predominately in the vicinity of 11:00 - 12:00 LTST, but occasionally in the early morning near 08:00 LTST. We find that throughout the Martian year, the daytime VMR is higher than at night, with a maximum day-to-night ratio of about 6 during winter. Various processes might explain the differences between nighttime REMS and daytime CCAM VMR values. Potential explanations include: (i) surface nighttime frost formation followed by daytime sublimation [1], (ii) surface nighttime adsorption of water vapor by the regolith followed by daytime desorption and (iii) large scale circulations changing vertical H2O profiles at different times of the year. Potential formation of surface frost can only occur in late fall and winter [1], coinciding with the time when the diurnal amplitude of the near

  10. Meteorological controls on the diurnal variability of carbon monoxide mixing ratio at a mountaintop monitoring site in the Appalachian Mountains

    Directory of Open Access Journals (Sweden)

    Temple R. Lee

    2015-05-01

    Full Text Available The variability of trace gases such as carbon monoxide (CO at surface monitoring stations is affected by meteorological forcings that are particularly complicated over mountainous terrain. A detailed understanding of the impact of meteorological forcings on trace gas variability is challenging, but is vital to distinguish trace gas measurements affected by local pollutant sources from measurements representative of background mixing ratios. In the present study, we investigate the meteorological and CO characteristics at Pinnacles (38.61 N, 78.35 W, 1017 m above mean sea level, a mountaintop monitoring site in northwestern Virginia, USA, in the Appalachian Mountains, from 2009 to 2012, and focus on understanding the dominant meteorological forcings affecting the CO variability on diurnal timescales. The annual mean diurnal CO cycle shows a minimum in the morning between 0700 and 0900 LST and a maximum in the late afternoon between 1600 and 2000 LST, with a mean (median daily CO amplitude of 39.2±23.7 ppb (33.2 ppb. CO amplitudes show large day-to-day variability. The largest CO amplitudes, in which CO mixing ratios can change >100 ppb in <3 h, occur in the presence of synoptic disturbances. Under fair weather conditions, local- to regional-scale transport processes are found to be more important drivers of the diurnal CO variability. On fair weather days with northwesterly winds, boundary layer dilution causes a daytime CO decrease, resembling the variability observed atop tall towers in flat terrain. Fair weather days with a wind shift from the northwest to the south are characterised by an afternoon CO increase and resemble the variability observed at mountaintops influenced by the vertical transport of polluted air from adjacent valleys.

  11. Diurnal and Intra-Annual Variations in Greenhouse Gases at Fixed Sites in the San Francisco Bay Area

    Science.gov (United States)

    Newman, S.; Guha, A.; Martien, P. T.; Bower, J.; Perkins, I.; Randall, S.; Young, A.; Stevenson, E.; Hilken, H.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions to 80% below 1990 levels by 2050, consistent with the State of California's climate goals. Recently, the Air District's governing board adopted a 2017 Clean Air Plan which lays out the agency's vision and includes actions to put the region on a path towards achieving the 2050 goal while also reducing air pollution and related health impacts. The Plan includes GHG rule-making efforts, policy initiatives, local government partnerships, outreach, grants, and incentives, encompassing over 250 specific implementation actions across all economic sectors to effect ambitious emission reductions in the region. To track trends in atmospheric observations of GHGs and associated species and monitor changes in regional emission patterns, the Air District has established a fixed site network (CO2, CH4, CO) of one generally upwind site (Bodega Bay - on the coast north of Marin County) and three receptor sites (Bethel Island - east of the major refineries, in the Sacramento River Delta; Livermore - east of the bulk of the East Bay cities; and San Martin - south of the major city of San Jose). Having collected over a year of data for each of the fixed sites, the Air District is now investigating spatial and temporal variations in GHG emissions. Concentrating on variations in diurnal cycles, we see the commonly observed pattern of seasonal changes in diurnal amplitude at all sites, with larger variations during the winter than the summer, consistent with seasonally varying daily changes in planetary boundary layer heights. Investigations explore the weekday/weekend effect on the diurnal patterns and the effect of seasonal wind direction changes on the intra-annual variations of the local enhancements. The Air District is beginning to investigate the ways in which the fixed site network reflects the dominant

  12. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  13. ANALYSIS THE DIURNAL VARIATIONS ON SELECTED PHYSICAL AND PHYSIOLOGICAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    A. MAHABOOBJAN

    2010-12-01

    Full Text Available The purpose of the study was to analyze the diurnal variations on selected physical and physiological parameters such as speed, explosive power, resting heart rate and breath holding time among college students. To achieve the purpose of this study, a total of twenty players (n=20 from Government Arts College, Salem were selected as subjects To study the diurnal variation of the players on selected physiological and performance variables, the data were collected 4 times a day with every four hours in between the times it from 6.00 to 18.00 hours were selected as another categorical variable. One way repeated measures (ANOVA was used to analyze the data. If the obtained F-ratio was significant, Seheffe’s post-hoc test was used to find out the significant difference if anyamong the paired means. The level of significance was fixed at.05 level. It has concluded that both physical and physiological parameters were significantly deferred with reference to change of temperature in a day

  14. Diurnal Solar Energy Conversion and Photoprotection in Rice Canopies.

    Science.gov (United States)

    Meacham, Katherine; Sirault, Xavier; Quick, W Paul; von Caemmerer, Susanne; Furbank, Robert

    2017-01-01

    Genetic improvement of photosynthetic performance of cereal crops and increasing the efficiency with which solar radiation is converted into biomass has recently become a major focus for crop physiologists and breeders. The pulse amplitude modulated chlorophyll fluorescence technique (PAM) allows quantitative leaf level monitoring of the utilization of energy for photochemical light conversion and photoprotection in natural environments, potentially over the entire crop lifecycle. Here, the diurnal relationship between electron transport rate (ETR) and irradiance was measured in five cultivars of rice (Oryza sativa) in canopy conditions with PAM fluorescence under natural solar radiation. This relationship differed substantially from that observed for conventional short term light response curves measured under controlled actinic light with the same leaves. This difference was characterized by a reduced curvature factor when curve fitting was used to model this diurnal response. The engagement of photoprotective processes in chloroplast electron transport in leaves under canopy solar radiation was shown to be a major contributor to this difference. Genotypic variation in the irradiance at which energy flux into photoprotective dissipation became greater than ETR was observed. Cultivars capable of higher ETR at midrange light intensities were shown to produce greater leaf area over time, estimated by noninvasive imaging. © 2017 American Society of Plant Biologists. All Rights Reserved.

  15. The diurnal order of the image in Dracula

    Directory of Open Access Journals (Sweden)

    Claudio Vescia Zanini

    2015-02-01

    Full Text Available the article analyses images from Bram Stoker’s novel Dracula having as a main theoretical frame the Diurnal regime of the Image, proposed by Gilbert Durand in The Anthropological Structures of the Imaginary and presented by Durand himself as the “order of antithesis”. By presenting the main kinds of images proposed by Durand in binary pairs (theriomorphic and diæretic, nyctomorphic and spectacular, catamorphic and ascensional, the analysis proposed here aims at staying in tune with both the theoretical approach and the context of production of the novel. Victorian England at the end of the nineteenth century was a time of anxieties, fears and doubts, recurrent in the Victorian cultural production as a whole and well-depicted in Dracula, a work where binary oppositions also seem to be recurrent: life and death, good and evil, moral and desire, among others. The focus is on how the main character is perceived by the other characters, which ultimately affects our perception as readers. Images related to animals, colors, weapons and movements are also included in the analysis. The conclusion points out that the Diurnal Order is a prolific and coherent approach towards an understanding of Bram Stoker’s vampire novel.

  16. Seasonal and diurnal calling patterns of Ross and leopards

    Science.gov (United States)

    Rogers, Tracey L.; Rowney, Gayle A.; Ciaglia, Michaela B.; Cato, Douglas H.

    2005-09-01

    The temporal calling patterns of two Antarctic pack ice seals, the leopard and Ross seal, were examined. This included seasonal onset and decline of calling (coinciding with their breeding season) as well as diurnal changes. Understanding of calling behavior has important implications for acoustic surveying, since this allows the number of calls to be related to an index of the number of animals present and to estimate abundance. The monthly changes in diurnal calling and haul-out patterns (measured via satellite telemetry) were compared. Underwater acoustic recordings were made between 14 October 2003 and 10 January 2004 off Mawson, Eastern Antarctica (660 44.243S and 690 48.748E). Recordings were made using an Acoustics Recording Package (ARP by Dr. John Hildebrand, Scripps Institute of Oceanography, La Jolla, CA) which is designed to sit on the seafloor and passively record acoustic signals. The package was deployed at a depth of 1320.7 m. The sampling rate was 500 Hz and the effective bandwidth from 10 to 250 Hz, covering the bandwidth of only the low-frequency calls of the Ross and leopard seal.

  17. The Influence of Roof Material on Diurnal Urban Canyon Breathing

    Science.gov (United States)

    Abuhegazy, Mohamed; Yaghoobian, Neda

    2017-11-01

    Improvements in building energy use, air quality in urban canyons and in general urban microclimates require understanding the complex interaction between urban morphology, materials, climate, and inflow conditions. Review of the literature indicates that despite a long history of valuable urban microclimate studies, more comprehensive approaches are needed to address energy, and heat and flow transport in urban areas. In this study, a more comprehensive simulation of the diurnally varying street canyon flow and associated heat transport is numerically investigated, using Large-eddy Simulation (LES). We use computational modeling to examine the impact of diurnal variation of the heat fluxes from urban surfaces on the air flow and temperature distribution in street canyons with a focus on the role of roof materials and their temperature footprints. A detailed building energy model with a three-dimensional raster-type geometry provides urban surface heat fluxes as thermal boundary conditions for the LES to determine the key aero-thermodynamic factors that affect urban street ventilation.

  18. Diurnal Oscillations of Soybean Circadian Clock and Drought Responsive Genes

    Science.gov (United States)

    Marcolino-Gomes, Juliana; Rodrigues, Fabiana Aparecida; Fuganti-Pagliarini, Renata; Bendix, Claire; Nakayama, Thiago Jonas; Celaya, Brandon; Molinari, Hugo Bruno Correa; de Oliveira, Maria Cristina Neves; Harmon, Frank G.; Nepomuceno, Alexandre

    2014-01-01

    Rhythms produced by the endogenous circadian clock play a critical role in allowing plants to respond and adapt to the environment. While there is a well-established regulatory link between the circadian clock and responses to abiotic stress in model plants, little is known of the circadian system in crop species like soybean. This study examines how drought impacts diurnal oscillation of both drought responsive and circadian clock genes in soybean. Drought stress induced marked changes in gene expression of several circadian clock-like components, such as LCL1-, GmELF4- and PRR-like genes, which had reduced expression in stressed plants. The same conditions produced a phase advance of expression for the GmTOC1-like, GmLUX-like and GmPRR7-like genes. Similarly, the rhythmic expression pattern of the soybean drought-responsive genes DREB-, bZIP-, GOLS-, RAB18- and Remorin-like changed significantly after plant exposure to drought. In silico analysis of promoter regions of these genes revealed the presence of cis-elements associated both with stress and circadian clock regulation. Furthermore, some soybean genes with upstream ABRE elements were responsive to abscisic acid treatment. Our results indicate that some connection between the drought response and the circadian clock may exist in soybean since (i) drought stress affects gene expression of circadian clock components and (ii) several stress responsive genes display diurnal oscillation in soybeans. PMID:24475115

  19. A stochastic differential equation model of diurnal cortisol patterns

    Science.gov (United States)

    Brown, E. N.; Meehan, P. M.; Dempster, A. P.

    2001-01-01

    Circadian modulation of episodic bursts is recognized as the normal physiological pattern of diurnal variation in plasma cortisol levels. The primary physiological factors underlying these diurnal patterns are the ultradian timing of secretory events, circadian modulation of the amplitude of secretory events, infusion of the hormone from the adrenal gland into the plasma, and clearance of the hormone from the plasma by the liver. Each measured plasma cortisol level has an error arising from the cortisol immunoassay. We demonstrate that all of these three physiological principles can be succinctly summarized in a single stochastic differential equation plus measurement error model and show that physiologically consistent ranges of the model parameters can be determined from published reports. We summarize the model parameters in terms of the multivariate Gaussian probability density and establish the plausibility of the model with a series of simulation studies. Our framework makes possible a sensitivity analysis in which all model parameters are allowed to vary simultaneously. The model offers an approach for simultaneously representing cortisol's ultradian, circadian, and kinetic properties. Our modeling paradigm provides a framework for simulation studies and data analysis that should be readily adaptable to the analysis of other endocrine hormone systems.

  20. Diurnal oscillations of soybean circadian clock and drought responsive genes.

    Directory of Open Access Journals (Sweden)

    Juliana Marcolino-Gomes

    Full Text Available Rhythms produced by the endogenous circadian clock play a critical role in allowing plants to respond and adapt to the environment. While there is a well-established regulatory link between the circadian clock and responses to abiotic stress in model plants, little is known of the circadian system in crop species like soybean. This study examines how drought impacts diurnal oscillation of both drought responsive and circadian clock genes in soybean. Drought stress induced marked changes in gene expression of several circadian clock-like components, such as LCL1-, GmELF4- and PRR-like genes, which had reduced expression in stressed plants. The same conditions produced a phase advance of expression for the GmTOC1-like, GmLUX-like and GmPRR7-like genes. Similarly, the rhythmic expression pattern of the soybean drought-responsive genes DREB-, bZIP-, GOLS-, RAB18- and Remorin-like changed significantly after plant exposure to drought. In silico analysis of promoter regions of these genes revealed the presence of cis-elements associated both with stress and circadian clock regulation. Furthermore, some soybean genes with upstream ABRE elements were responsive to abscisic acid treatment. Our results indicate that some connection between the drought response and the circadian clock may exist in soybean since (i drought stress affects gene expression of circadian clock components and (ii several stress responsive genes display diurnal oscillation in soybeans.

  1. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  2. Solar cycle variability of nonmigrating tides in the infrared cooling of the thermosphere

    Science.gov (United States)

    Nischal, N.; Oberheide, J.; Mlynczak, M. G.; Marsh, D. R.

    2017-12-01

    Nitric Oxide (NO) at 5.3 μm and Carbon dioxide (CO2) at 15 μm are the major infrared emissions responsible for the radiative cooling of the thermosphere. We study the impact of two important diurnal nonmigrating tides, the DE2 and DE3, on NO and CO2 infrared emissions over a complete solar cycle (2002-2013) by (i) analyzing NO and CO2 cooling rate data from SABER and (ii) photochemical modeling using dynamical tides from a thermospheric empirical tidal model, CTMT. Both observed and modeled results show that the NO cooling rate amplitudes for DE2 and DE3 exhibit strong solar cycle dependence. NO 5.3 μm cooling rate tides are relatively unimportant for the infrared energy budget during solar minimum but important during solar maximum. On the other hand DE2 and DE3 in CO2 show comparatively small variability over a solar cycle. CO2 15 μm cooling rate tides remain, to a large extent, constant between solar minimum and maximum. This different responses by NO and CO2 emissions to the DE2 and DE3 during a solar cycle comes form the fact that the collisional reaction rate for NO is highly sensitive to the temperature comparative to that for CO2. Moreover, the solar cycle variability of these nonmigrating tides in thermospheric infrared emissions shows a clear QBO signals substantiating the impact of tropospheric weather system on the energy budget of the thermosphere. The relative contribution from the individual tidal drivers; temperature, density and advection to the observed DE2 and DE3 tides does not vary much over the course of the solar cycle, and this is true for both NO and CO2 emissions.

  3. Origin of the Animal Circadian Clock: Diurnal and Light-Entrained Gene Expression in the Sponge Amphimedon queenslandica

    Directory of Open Access Journals (Sweden)

    Katia Jindrich

    2017-10-01

    Full Text Available The circadian clock is a molecular network that coordinates organismal behavior and physiology with daily environmental changes in the day-night cycle. In eumetazoans (bilaterians + cnidarians, this network appears to be largely conserved, yet different from other known eukaryotic circadian networks. To determine if the eumetazoan circadian network has an older origin, we ask here whether orthologs comprising this network are expressed in a manner consistent with a role in regulating circadian patterns in a representative of an earlier-branching animal lineage, the sponge Amphimedon queenslandica. The A. queenslandica genome encodes orthologs of many eumetazoan circadian genes, including two cryptochrome genes that encode flavoproteins, three Timeout genes, and two PAR-bZIP and seven bHLH-PAS transcription factor genes. There is no apparent Cycle ortholog, although we can identify three closely related ARNT genes. Of the putative circadian genes, only AqPARa and AqCry2 have a consistent oscillating diurnal expression profile, and the rhythmic expression of both these genes is partially lost when the animals are exposed to constant light or darkness. Expression of the other putative circadian genes, in particular AqClock, is neither diurnally-oscillating nor light-dependent. AqPARa and AqCry2 are also temporally and spatially co-expressed throughout embryonic and larval development. Transcripts of these genes are enriched first in cells comprising the larval posterior pigment ring, which is a simple photosensory organ that is responsible for the negative phototactic behavior displayed by larvae, and subsequently in the larval epithelial and subepithelial layers. The combined findings of no clear Cycle ortholog and of PAR-bZIP and cryptochrome being the only orthologs expressed in a pattern consistent with a circadian role suggests that either (i the ancestral metazoan circadian network was simpler than the eumetazoan network, or (ii that this

  4. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  5. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  6. Diurnal variation in the control of ventilation in response to rising body temperature during exercise in the heat.

    Science.gov (United States)

    Tsuji, Bun; Honda, Yasushi; Kondo, Narihiko; Nishiyasu, Takeshi

    2016-08-01

    We investigated whether heat-induced hyperventilation during exercise is affected by time of day, as diurnal variation leads to higher core temperatures in the evening. Nineteen male subjects were divided into two experiments (protocol 1, n = 10 and protocol 2, n = 9). In protocol 1, subjects performed cycle exercise at 50% peak oxygen uptake in the heat (37°C and 50% RH) in the morning (0600) and evening (1800). Results showed that baseline resting and exercising esophageal temperature (Tes) were significantly (0.5°C) higher in the evening than morning. Minute ventilation (V̇e) increased from 54.3 ± 7.9 and 54.9 ± 6.8 l/min at 10 min to 71.4 ± 8.1 and 76.5 ± 11.8 l/min at 48.5 min in the morning and evening, respectively (both P temperature is smaller in the evening. In protocol 2, the circadian rhythm-related higher resting Tes seen in the evening was adjusted down to the same temperature seen in the morning by immersing the subject in cold water. Importantly, the time course of changes in V̇e during exercise were smaller in the evening, but the threshold for V̇e remained higher in the evening than morning (P temperatures in the evening. This is likely due to diurnal variation in the control of ventilation in response to rising core temperature. Copyright © 2016 the American Physiological Society.

  7. Educational Business Cycles

    DEFF Research Database (Denmark)

    Tepe, Markus; Vanhuysse, Pieter

    2009-01-01

    teacher employment patterns at the state level in Germany and find strong evidence of cycling mechanisms, in the form of electioneering and honeymooning. Against a backdrop of a continuously shrinking total teachers' pool, German state-level incumbents accelerate the hiring of new teachers during election...

  8. Diurnal periodicity in the activity of the common sole, solea vulgaris quensel

    NARCIS (Netherlands)

    Kruuk, H.

    1963-01-01

    1. 1. The diurnal rhythm in the trawl catch of Solea vulgaris Quensel gave rise to this investigation into the diurnal activity rhythm of the fish. 2. 2. Periodicity in the food intake of the Sole in its natural habitat was studied by analyses of the contents of the intestines. Food intake

  9. Diurnality as an energy-saving strategy : energetic consequences of temporal niche switching in small mammals

    NARCIS (Netherlands)

    van der Vinne, Vincent; Gorter, Jenke A; Riede, Sjaak J; Hut, Roelof A

    Endogenous daily (circadian) rhythms allow organisms to anticipate daily changes in the environment. Most mammals are specialized to be active during the night (nocturnal) or day (diurnal). However, typically nocturnal mammals become diurnal when energetically challenged by cold or hunger. The

  10. Diurnality as an energy-saving strategy: energetic consequences of temporal niche switching in small mammals

    NARCIS (Netherlands)

    van der Vinne, V.; Gorter, J.A.; Riede, S.J.; Hut, R.A.

    2015-01-01

    Endogenous daily (circadian) rhythms allow organisms to anticipate daily changes in the environment. Most mammals are specialized to be active during the night (nocturnal) or day (diurnal). However, typically nocturnal mammals become diurnal when energetically challenged by cold or hunger. The

  11. The influence of diurnal temperature variation on degree-day accumulation and insect life history.

    Directory of Open Access Journals (Sweden)

    Shi Chen

    Full Text Available Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges. Here we apply a degree-day model for development of the grape berry moth (Paralobesia viteana, a significant vineyard pest in the northeastern USA to investigate how different diurnal temperature range conditions can influence degree-day accumulation and, hence, insect life history. We first consider changes in diurnal temperature range independent of changes in mean temperatures. We then investigate grape berry moth life history under potential climate change conditions, increasing mean temperature via variable patterns of change to diurnal temperature range. We predict that diurnal temperature range change can substantially alter insect life history. Altering diurnal temperature range independent of the mean temperature can affect development rate and voltinism, with the magnitude of the effects dependent on whether changes occur to the daily minimum temperature (Tmin, daily maximum temperature (Tmax, or both. Allowing for an increase in mean temperature produces more marked effects on life history but, again, the patterns and magnitude depend on the nature of the change to diurnal temperature range together with the starting conditions in the local environment. The study highlights the importance of characterizing the influence of diurnal temperature range in addition to mean temperature alone.

  12. Diurnal variation in blood parameters in the chicken in the hot ...

    African Journals Online (AJOL)

    Variations in the levels of these parameters throughout the 24 hours were determined. Thirteen out of the parameters measured showed significant diurnal variations. These include RBC, PCV, Hb, MVC, WBC, Na+, K+, urea, cholesterol, triglycerides, ALP, GPT and GGT. Keywords: Diurnal variation; blood picture; chicken.

  13. On the diurnal ranges of Sea Surface Temperature (SST) in the ...

    Indian Academy of Sciences (India)

    The variability of sea surface temperature (SST) is widely studied due to its large impact on ocean–atmosphere interaction. Kawai and Wada. (2007) provides an excellent review on the impor- tance of the diurnal variability of SST on air– sea interaction. Diurnal variations in the SST affect longer time-scale variability events ...

  14. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  15. Daily diurnal variation in admissions for ruptured abdominal aortic aneurysms.

    LENUS (Irish Health Repository)

    Killeen, Shane

    2012-02-03

    BACKGROUND: Many vascular events, such as myocardial infarction and cerebrovascular accident, demonstrate a circadian pattern of presentation. Blood pressure is intimately related to these pathologies and is the one physiological variable consistently associated with abdominal aortic aneurysm rupture. It also demonstrates a diurnal variation. The purpose of this study was to determine if rupture of an abdominal aortic aneurysm (RAAA) exhibits a diurnal variation. METHODS: A retrospective cohort-based study was performed to determine the timing of presentation of RAAA to the vascular unit of Cork University Hospital over a 15-year period. Time of admission, symptom onset, and co-morbidities such as hypertension were noted. Fournier\\'s analysis and chi-squared analysis were performed. To ameliorate possible confounding factors, patients admitted with perforated peptic ulcers were examined in the same manner. RESULTS: A total of 148 cases of RAAA were identified, with a male preponderance (71.7% [124] male versus 29.3% [44] female patients) and a mean age of 74.4 +\\/- 7.2 years at presentation. 70.9% (105) were known to have hypertension, 52.2% (77) were current smokers, and 46.8% (69) were being treated for chronic obstructive airway disease (COAD). Time of symptom onset was recorded in 88.5% (131) of patients. There was a marked early morning peak in RAAA admissions, with the highest number of RAAA being admitted between 08.00 and 09.59. A second, smaller peak was observed at 14.00-15.59. These findings were suggestive of diurnal variation. [chi(2) =16.75, p < 0.003]. Some 40% (59) of patients were admitted between 00.00 and 06.00, an incidence significantly higher than for other time periods (06.00-12.00, 12.00-18.00, and 18.00-24.00) [chi(2) = 18.72; df = 3; p < 0.0003]. A significantly higher number of patients admitted between 00.00 and 06.00 were known hypertensives (chi(2) = 7.94; p < 0.05). CONCLUSIONS: The findings of this study suggest a distinct

  16. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  17. Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp.: An energetic advantage

    Science.gov (United States)

    McGinnis, Daniel F.; Flury, Sabine; Tang, Kam W.; Grossart, Hans-Peter

    2017-03-01

    Diurnally-migrating Chaoborus spp. reach populations of up to 130,000 individuals m-2 in lakes up to 70 meters deep on all continents except Antarctica. Linked to eutrophication, migrating Chaoborus spp. dwell in the anoxic sediment during daytime and feed in the oxic surface layer at night. Our experiments show that by burrowing into the sediment, Chaoborus spp. utilize the high dissolved gas partial pressure of sediment methane to inflate their tracheal sacs. This mechanism provides a significant energetic advantage that allows the larvae to migrate via passive buoyancy rather than more energy-costly swimming. The Chaoborus spp. larvae, in addition to potentially releasing sediment methane bubbles twice a day by entering and leaving the sediment, also transport porewater methane within their gas vesicles into the water column, resulting in a flux of 0.01-2 mol m-2 yr-1 depending on population density and water depth. Chaoborus spp. emerging annually as flies also result in 0.1-6 mol m-2 yr-1 of carbon export from the system. Finding the tipping point in lake eutrophication enabling this methane-powered migration mechanism is crucial for ultimately reconstructing the geographical expansion of Chaoborus spp., and the corresponding shifts in the lake’s biogeochemistry, carbon cycling and food web structure.

  18. Epithermal Neutron Evidence for a Diurnal Surface Hydration Process in the Moon's High Latitudes

    Science.gov (United States)

    McClanahan, T. P.; Mitrofanov, I. G.; Boynton, W. V.; Chin, G.; Parsons, A.; Starr, R. D.; Evans, L. G.; Sanin, A.; Litvak, M.; Livengood, T.

    2015-01-01

    We report evidence from epithermal neutron flux observations that show that the Moon's high latitude surfaces are being actively hydrated, dehydrated and rehydrated in a diurnal cycle. The near-surface hydration is indicated by an enhanced suppression of the lunar epithermal neutron leakage flux on the dayside of the dawn terminator on poleward-facing slopes (PFS). At 0600 to 0800 local-time, hydrogen concentrations within the upper 1 meter of PFS are observed to be maximized relative to equivalent equator-facing slopes (EFS). During the lunar day surface hydrogen concentrations diminish towards dusk and then rebuild overnight. Surface hydration is determined by differential comparison of the averaged EFS to PFS epithermal neutron count rates above +/- 75 deg latitude. At dawn the contrast bias towards PFS is consistent with at least 15 to 25 parts-per-million (ppm) hydrogen that dissipates by dusk. We review several lines of evidence derived from temperature and epithermal neutron data by a correlated analysis of observations from the Lunar Reconnaissance Orbiter's (LRO) Lunar Exploration Neutron Detector (LEND) that were mapped as a function of lunar local-time, Lunar Observing Laser Altimeter (LOLA) topography and Diviner (DLRE) surface temperature.

  19. Diurnal changes in urban boundary layer environment induced by urban greening

    Science.gov (United States)

    Song, Jiyun; Wang, Zhi-Hua

    2016-11-01

    Urban green infrastructure has been widely used for mitigating adverse environmental problems as well as enhancing urban sustainability of cities worldwide. Here we develop an integrated urban-land-atmosphere modeling framework with the land surface processes parameterized by an advanced urban canopy model and the atmospheric processes parameterized by a single column model. The model is then applied to simulate a variety of forms of green infrastructure, including urban lawns, shade trees, green and cool roofs, and their impact on environmental changes in the total urban boundary layer (UBL) for a stereotypical desert city, viz. Phoenix, Arizona. It was found that green roofs have a relatively uniform cooling effect proportional to their areal coverage. In particular, a reduction of UBL temperature of 0.3 °C and 0.2 °C per 10% increase of green roof coverage was observed at daytime and nighttime, respectively. In contrast, the effect of greening of street canyons is constrained by the overall abundance of green infrastructure and the energy available for evapotranspiration. In addition, the increase in urban greening causes boundary-layer height to decrease during daytime but increase at nighttime, leading to different trends of changes in urban air quality throughout a diurnal cycle.

  20. Novel concept for the emulation of ground-target diurnal infrared signatures

    Science.gov (United States)

    Sanders, Jeffrey S.

    1998-07-01

    This paper describes a novel method for enhancing the infrared signature of surrogate or decoy armored vehicles. The method consists of using water tanks of a calculated thickness to emulate the heat capacity of thick metal on armored ground vehicles. Extensive experiments have shown that the surface temperature of the water tanks closely matches the surface temperature of thick metal plates over an entire diurnal cycle. Passive infrared signatures are duplicated since the surrogate vehicle component has the same innate thermal characteristics of the vehicle component to be emulated. Multiple fidelity, cost, and labor saving advantages are included by using water tanks. Infrared signature fidelity is enhanced since the water tank will have the correct surface temperature irregardless of location, time of day, time of year, or weather conditions. No external heat inputs are necessary to constantly adjust the water tank's temperature. The tanks can be made from any thickness of metal which greatly reduces the cost of materials and labor to construct a surrogate or decoy vehicle. This paper presents the derivation of the design equations for the water tanks as well as extensive experimental results under a variety of environmental conditions. In addition, results are presented for a similar concept where the equivalent heat capacity concept is used to replace solid aluminum with thinner plates of solid steel.

  1. Individual Differences in Diurnal Preference and Time-of-Exercise Interact to Predict Exercise Frequency.

    Science.gov (United States)

    Hisler, Garrett C; Phillips, Alison L; Krizan, Zlatan

    2017-06-01

    Diurnal preference (and chronotype more generally) has been implicated in exercise behavior, but this relation has not been examined using objective exercise measurements nor have potential psychosocial mediators been examined. Furthermore, time-of-day often moderates diurnal preference's influence on outcomes, and it is unknown whether time-of-exercise may influence the relation between chronotype and exercise frequency. The current study examined whether individual differences in diurnal preference ("morningness-eveningness") predict unique variance in exercise frequency and if commonly studied psychosocial variables mediate this relation (i.e., behavioral intentions, internal exercise control, external exercise control, and conscientiousness). Moreover, the study sought to test whether individuals' typical time-of-exercise moderated the impact of diurnal preference on exercise frequency. One hundred twelve healthy adults (mean age = 25.4; SD = 11.6 years) completed baseline demographics and then wore Fitbit Zips® for 4 weeks to objectively measure exercise frequency and typical time-of-exercise. At the end of the study, participants also self-reported recent exercise. Diurnal preference predicted both self-reported exercise and Fitbit-recorded exercise frequency. When evaluating mediators, only conscientiousness emerged as a partial mediator of the relation between diurnal preference and self-reported exercise. In addition, time-of-exercise moderated diurnal preference's relation to both self-reported exercise and Fitbit-recorded exercise frequency such that diurnal preference predicted higher exercise frequency when exercise occurred at a time that was congruent with one's diurnal preference. Based on these findings, diurnal preference is valuable, above and beyond other psychological constructs, in predicting exercise frequency and represents an important variable to incorporate into interventions seeking to increase exercise.

  2. Presumed symbolic use of diurnal raptors by Neanderthals.

    Directory of Open Access Journals (Sweden)

    Eugène Morin

    Full Text Available In Africa and western Eurasia, occurrences of burials and utilized ocher fragments during the late Middle and early Late Pleistocene are often considered evidence for the emergence of symbolically-mediated behavior. Perhaps less controversial for the study of human cognitive evolution are finds of marine shell beads and complex designs on organic and mineral artifacts in early modern human (EMH assemblages conservatively dated to ≈ 100-60 kilo-years (ka ago. Here we show that, in France, Neanderthals used skeletal parts of large diurnal raptors presumably for symbolic purposes at Combe-Grenal in a layer dated to marine isotope stage (MIS 5b (≈ 90 ka and at Les Fieux in stratigraphic units dated to the early/middle phase of MIS 3 (60-40 ka. The presence of similar objects in other Middle Paleolithic contexts in France and Italy suggest that raptors were used as means of symbolic expression by Neanderthals in these regions.

  3. Providing Diurnal Sky Cover Data at ARM Sites

    Energy Technology Data Exchange (ETDEWEB)

    Klebe, Dimitri I. [Solmirus Corporation, Colorado Springs, CO (United States)

    2015-03-06

    The Solmirus Corporation was awarded two-year funding to perform a comprehensive data analysis of observations made during Solmirus’ 2009 field campaign (conducted from May 21 to July 27, 2009 at the ARM SGP site) using their All Sky Infrared Visible Analyzer (ASIVA) instrument. The objective was to develop a suite of cloud property data products for the ASIVA instrument that could be implemented in real time and tailored for cloud modelers. This final report describes Solmirus’ research and findings enabled by this grant. The primary objective of this award was to develop a diurnal sky cover (SC) data product utilizing the ASIVA’s infrared (IR) radiometrically-calibrated data and is described in detail. Other data products discussed in this report include the sky cover derived from ASIVA’s visible channel and precipitable water vapor, cloud temperature (both brightness and color), and cloud height inferred from ASIVA’s IR channels.

  4. Blunted Diurnal Cortisol Activity in Healthy Adults with Childhood Adversity

    Directory of Open Access Journals (Sweden)

    Yuliya I. Kuras

    2017-11-01

    Full Text Available Childhood adversity, such as neglect, or physical, emotional, or sexual abuse, is prevalent in the U.S. and worldwide, and connected to an elevated incidence of disease in adulthood. A pathway in this relationship might be altered hypothalamic-pituitary-adrenal (HPA axis functioning, as a result of differential hippocampal development in early life. A blunted diurnal cortisol slope is a precursor for many disorders. While studies have focused on HPA reactivity in relation to childhood adversity, there has been markedly less research on basal HPA functioning in those with low-to-moderate adversity. Based on previous research, we hypothesized that adults with low-to-moderate childhood adversity would have altered HPA axis functioning, as evidenced by a blunted diurnal cortisol slope and altered cortisol awakening response (CAR. Healthy adults aged 18–65 (n = 61 adults; 31 males and 30 females completed the Childhood Trauma Questionnaire. Participants provided at-home saliva samples on two consecutive days at wake-up, and 30 min, 1, 4, 9, and 13 h later; samples were averaged over the 2 days. We found that low-to-moderate childhood adversity predicted lower morning cortisol (β = -0.34, p = 0.007, R2 = 0.21, as well as a blunted cortisol slope (β = 2.97, p = 0.004, R2 = 0.22, but found no association with CAR (β = 0.19, p = 0.14, R2 = 0.12. Overall, we found that in healthy participants, low-to-moderate adversity in childhood is associated with altered basal HPA activity in adulthood. Our findings indicate that even low levels of childhood adversity may predispose individuals to disease associated with HPA dysregulation in later life.

  5. Blunted Diurnal Cortisol Activity in Healthy Adults with Childhood Adversity.

    Science.gov (United States)

    Kuras, Yuliya I; Assaf, Naomi; Thoma, Myriam V; Gianferante, Danielle; Hanlin, Luke; Chen, Xuejie; Fiksdal, Alexander; Rohleder, Nicolas

    2017-01-01

    Childhood adversity, such as neglect, or physical, emotional, or sexual abuse, is prevalent in the U.S. and worldwide, and connected to an elevated incidence of disease in adulthood. A pathway in this relationship might be altered hypothalamic-pituitary-adrenal (HPA) axis functioning, as a result of differential hippocampal development in early life. A blunted diurnal cortisol slope is a precursor for many disorders. While studies have focused on HPA reactivity in relation to childhood adversity, there has been markedly less research on basal HPA functioning in those with low-to-moderate adversity. Based on previous research, we hypothesized that adults with low-to-moderate childhood adversity would have altered HPA axis functioning, as evidenced by a blunted diurnal cortisol slope and altered cortisol awakening response (CAR). Healthy adults aged 18-65 ( n = 61 adults; 31 males and 30 females) completed the Childhood Trauma Questionnaire. Participants provided at-home saliva samples on two consecutive days at wake-up, and 30 min, 1, 4, 9, and 13 h later; samples were averaged over the 2 days. We found that low-to-moderate childhood adversity predicted lower morning cortisol (β = -0.34, p = 0.007, R 2 = 0.21), as well as a blunted cortisol slope (β = 2.97, p = 0.004, R 2 = 0.22), but found no association with CAR (β = 0.19, p = 0.14, R 2 = 0.12). Overall, we found that in healthy participants, low-to-moderate adversity in childhood is associated with altered basal HPA activity in adulthood. Our findings indicate that even low levels of childhood adversity may predispose individuals to disease associated with HPA dysregulation in later life.

  6. Monthly and diurnal variations of limnological conditions of two ponds

    Directory of Open Access Journals (Sweden)

    AKM Fazlur Rahaman

    2017-06-01

    Full Text Available A study on monthly and diurnal changes of limnological conditions of two ponds was conducted in the Bangladesh Agricultural University campus, Mymensingh. The research work was performed by studying the limnological parameters such as transparency, temperature, dissolved oxygen, free carbon dioxide, pH, total alkalinity, nitrate-nitrogen, phosphate-phosphorus and plankton. Diurnal variations of physico-chemical factors were studied fortnightly at 6 hrs intervals at 6 a.m., 12 noon, 6 p.m. and 12 midnight. The amounts of transparency, dissolved oxygen and pH were higher during winter months than in summer months in both the ponds. Transparency, water temperature, total alkalinity, NO3-N and PO4-P were higher during summer months than in winter months in both the ponds. But the amount of free carbon dioxide was higher during winter months than in summer months in pond 1 while in pond 2 the amount of free carbon dioxide was higher during summer months than in winter months. Qualitative and quantitative monthly variations of phytoplankton and zooplankton were observed in both the ponds during the study period. The highest amount of dissolved oxygen, pH and total alkalinity were recorded at 6 p.m. and the lowest amounts of those at 6 a.m. in both the ponds. The highest temperature was recorded at 12 noon and the lowest at 12 midnight. But the highest amount of free carbon dioxide was recorded at 6 a.m. and the lowest at 6 p.m. in both the ponds. All the factors showed appreciable diel variations throughout the study period, which indicate that the ponds are productive.

  7. Tracking Seasonal and Diurnal Photosynthesis and Plant Water Status in Maize Using SIF, Eddy Covariance Fluxes, PAM Fluorescence and Gas Exchange

    Science.gov (United States)

    Chang, C.; Melkonian, J.; Riha, S. J.; Gu, L.; Sun, Y.

    2017-12-01

    Improving the sensitivity of methods for crop monitoring and yield forecasting is crucial as the frequency of extreme weather events increases. Conventional remote monitoring methods rely on greenness-based indices such as NDVI and EVI, which do not directly measure photosynthesis and are not sufficiently sensitive to rapid plant stress response. Solar-induced chlorophyll fluorescence (SIF) is a promising new technology that serves as a direct functional proxy of photosynthesis. We developed the first system utilizing dual QE Pro spectrometers to continuously measure the diurnal and seasonal cycle of SIF, and deployed the system in a corn field in upstate New York in 2017. To complement SIF, canopy-level measurements of carbon and water fluxes were also measured, along with concurrent leaf-level measurements of gas exchange and PAM fluorescence, midday water potential, leaf pigments, phenology, LAI, and soil moisture. We show that SIF is well correlated to GPP during the growing season and show that both are controlled by similar environmental conditions including PAR and water availability. We also describe diurnal changes in photosynthesis and plant water status and demonstrate the sensitivity of SIF to diurnal plant response.

  8. Capabilities of scatterometer for detection of diurnal thaw and refreeze of snow cover

    Science.gov (United States)

    Bartsch, A.; Naeimi, V.; Wagner, W.

    2009-04-01

    Microwave sensors with short wavelengths such as SeaWinds Quikscat (Ku-band) are sensitive to changes at snow surfaces due to thaw. Especially scatterometer can provide several measurements per day at high latitudes. Diurnal differences are investigated in a range of studies since they indicate exactly when snowmelt is taking place. Large changes in backscatter between morning and evening acquisitions are characteristic for the snowmelt period, when freezing takes place over night and thawing of the surface during the day. A change from volume to surface scattering occurs in case of melting. The actual number of dates of snow thaw is of most interest for glacier mass balance studies but the final disappearance of snow together with the length of spring thaw is required in regions with seasonal snow cover. When significant changes due to freeze/thaw cycling cease, closed snow cover also disappears. The exact day of year of beginning and end of freeze/thaw cycling can be clearly determined using QuikScat with consideration of long-term noise in order to exclude unnatural effects and changes in soil moisture and snow pack characteristics. SeaWinds Quikscat measurements are available since 1999. The first entire snowmelt period on the northern hemisphere is covered in 2000. A further scatteromter which provides the necessary observation intervals at high latitudes is the Metop ASCAT. It acquires data with %80 daily global coverage but at a longer wavelength (C-band) and different incidence angles since 2007. Comparison examples showing the capabilities of the two different sensors for the purpose of snowmelt detection are presented for high latitude regions and mountainous terrain at mid latitudes (Alps).

  9. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  10. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  11. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  12. [Diurnal changes in greenhouse gases at water-air interface of Xiangxi River in autumn and their influencing factors].

    Science.gov (United States)

    Huang, Wen-Min; Zhu, Kong-Xian; Zhao, Wei; Yu, Bo-Shi; Yuan, Xi-Gong; Feng, Rui-Jie; Bi, Yong-Hong; Hu, Zheng-Yu

    2013-04-01

    With the closed chamber and gas chromatography method, a 24-hour continuous monitoring was carried out to understand the greenhouse gases fluxes across the water-air interface of the Xiangxi River Bay, the Three-Gorges Reservoir in Autumn. Results indicated that the fluxes of CO2, CH4 and N2O across the water-air interface showed an obvious diurnal variation. The absorption and emission process of CH4 showed strong diurnal variation during the experimental period, reaching the highest emission at 1 am, whereas CO2 and N2O were emitted all day. The fluxes of CO2 ranged from 20.1-97.5 mg x (m2 x h)(-1) at day and 32.7-42.5 mg x (m2 x h)(-1) at night, the fluxes of N2O ranged from 18.4-133.7 microg x (m2 x h)(-1) at day and 42.1-102.6 microg x (m2 x h)(-1) at night. The fluxes of CO2 had positive correlation with wind speed and negative correlation with pH. The fluxes of N2O had positive correlation with pH.

  13. Diurnal variation in probability of death following self-poisoning in Sri Lanka—evidence for chronotoxicity in humans

    Science.gov (United States)

    Metcalfe, Chris; Gunnell, David; Mohamed, Fahim; Eddleston, Michael

    2012-01-01

    Background The absorption, distribution, metabolism and elimination of medicines are partly controlled by transporters and enzymes with diurnal variation in expression. Dose timing may be important for maximizing therapeutic and minimizing adverse effects. However, outcome data for such an effect in humans are sparse, and chronotherapeutics is consequently less practised. We examined a large prospective Sri Lankan cohort of patients with acute poisoning to seek evidence of diurnal variation in the probability of survival. Methods In all, 14 840 patients admitted to hospital after yellow oleander (Cascabela thevetia) seed or pesticide [organophosphorus (OP), carbamate, paraquat, glyphosate] self-poisoning were investigated for variation in survival according to time of ingestion. Results We found strong evidence that the outcome of oleander poisoning was associated with time of ingestion (P poisoning was over 50% lower following evening ingestion (risk ratio = 0.40, 95% confidence interval 0.26–0.62). Variation in dose across the day was not responsible. Conclusions We have shown for the first time that timing of poison ingestion affects survival in humans. This evidence for chronotoxicity suggests chronotherapeutics should be given greater attention in drug development and clinical practice. PMID:23179303

  14. Diurnal variation in probability of death following self-poisoning in Sri Lanka--evidence for chronotoxicity in humans.

    Science.gov (United States)

    Carroll, Robert; Metcalfe, Chris; Gunnell, David; Mohamed, Fahim; Eddleston, Michael

    2012-12-01

    The absorption, distribution, metabolism and elimination of medicines are partly controlled by transporters and enzymes with diurnal variation in expression. Dose timing may be important for maximizing therapeutic and minimizing adverse effects. However, outcome data for such an effect in humans are sparse, and chronotherapeutics is consequently less practised. We examined a large prospective Sri Lankan cohort of patients with acute poisoning to seek evidence of diurnal variation in the probability of survival. In all, 14 840 patients admitted to hospital after yellow oleander (Cascabela thevetia) seed or pesticide [organophosphorus (OP), carbamate, paraquat, glyphosate] self-poisoning were investigated for variation in survival according to time of ingestion. We found strong evidence that the outcome of oleander poisoning was associated with time of ingestion (P poisoning was over 50% lower following evening ingestion (risk ratio = 0.40, 95% confidence interval 0.26-0.62). Variation in dose across the day was not responsible. We have shown for the first time that timing of poison ingestion affects survival in humans. This evidence for chronotoxicity suggests chronotherapeutics should be given greater attention in drug development and clinical practice.

  15. Diurnal and vertical variability of the sensible heat and carbon dioxide budgets in the atmospheric surface layer

    International Nuclear Information System (INIS)

    Casso-Torralba, P.; Rosa Soler, M.; Vila-Guerau de Arellano, J.; Bosveld, F.; Vermeulen, A.; Werner, C.; Moors, E.

    2008-08-01

    The diurnal and vertical variability of heat and carbon dioxide (CO2) in the atmospheric surface layer are studied by analyzing measurements from a 213 m tower in Cabauw (Netherlands). Observations of thermodynamic variables and CO2 mixing ratio as well as vertical profiles of the turbulent fluxes are used to retrieve the contribution of the budget terms in the scalar conservation equation. On the basis of the daytime evolution of turbulent fluxes, we calculate the budget terms by assuming that turbulent fluxes follow a linear profile with height. This assumption is carefully tested and the deviation from linearity is quantified. The budget calculation allows us to assess the importance of advection of heat and CO2 during day hours for three selected days. It is found that, under nonadvective conditions, the diurnal variability of temperature and CO2 is well reproduced from the flux divergence measurements. Consequently, the vertical transport due to the turbulent flux plays a major role in the daytime evolution of both scalars and the advection is a relatively small contribution. During the analyzed days with a strong contribution of advection of either heat or carbon dioxide, the flux divergence is still an important contribution to the budget. For heat, the quantification of the advection contribution is in close agreement with results from a numerical model. For carbon dioxide, we qualitatively corroborate the results with a Lagrangian transport model. Our estimation of advection is compared with traditional estimations based on the Net Ecosystem-atmosphere Exchange (NEE)

  16. Multisensor Advanced Climatology Mean Liquid Water Path Diurnal Cycle L3 Monthly 1 degree x 1 degree V1 (MACLWP_diurnal) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Multi-Sensor Advanced Climatology of Liquid Water Path (MAC-LWP) data set contains monthly 1.0-degree ocean-only estimates of cloud liquid water path...

  17. Diurnal effects of prior heat stress exposure on sprint and endurance exercise capacity in the heat.

    Science.gov (United States)

    Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Goto, Heita; Goto, Takayuki; Shirato, Minayuki

    2018-03-21

    Active individuals often perform exercises in the heat following heat stress exposure (HSE) regardless of the time-of-day and its variation in body temperature. However, there is no information concerning the diurnal effects of a rise in body temperature after HSE on subsequent exercise performance in a hot environnment. This study therefore investigated the diurnal effects of prior HSE on both sprint and endurance exercise capacity in the heat. Eight male volunteers completed four trials which included sprint and endurance cycling tests at 30 °C and 50% relative humidity. At first, volunteers completed a 30-min pre-exercise routine (30-PR): a seated rest in a temperate environment in AM (AmR) or PM (PmR) (Rest trials); and a warm water immersion at 40 °C to induce a 1 °C increase in core temperature in AM (AmW) or PM (PmW) (HSE trials). Volunteers subsequently commenced exercise at 0800 h in AmR/AmW and at 1700 h in PmR/PmW. The sprint test determined a 10-sec maximal sprint power at 5 kp. Then, the endurance test was conducted to measure time to exhaustion at 60% peak oxygen uptake. Maximal sprint power was similar between trials (p = 0.787). Time to exhaustion in AmW (mean±SD; 15 ± 8 min) was less than AmR (38 ± 16 min; p temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p temperature during the endurance test was greater in AmR than AmW and PmW (p Mean skin temperature was higher from post 30-PR to 6 min into the endurance test in HSE trials than Rest trials (p Mean body temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p radiant, dry and evaporative heat losses were greater on HSE trials than on Rest trials (p temperature by prior HSE has the diurnal effects on endurance exercise capacity but not on sprint exercise capacity in the heat. Moreover, prior HSE reduces endurance exercise capacity in AM, but not in PM. This

  18. Contribution of diurnal and nocturnal insects to the pollination of Jatropha curcas (Euphorbiaceae) in southwestern China.

    Science.gov (United States)

    Luo, Chang W; Huang, Zachary Y; Chen, Xiao M; Li, Kun; Chen, You; Sun, Yong Y

    2011-02-01

    Jatropha curcas L. (Euphorbiaceae) is being increasingly planted worldwide, but questions remain regarding its pollination biology. This study examined the contribution of diurnal and nocturnal insects to the pollination of monoecious J. curcas, through its floral biology, pollination ecology, and foraging behavior of potential pollinators. Nectar production of both male and female flowers peaked in the morning, declined in the afternoon, and rapidly bottomed during the night in all of their anthesis days. The diurnal visitors to the flowers of J. curcas are bees and flies, and the nocturnal visitors are moths. Flowers received significantly more visits by diurnal insects than by nocturnal insects. Through bagging flowers during night or day or both or exclusion, we compared fruit and seed production caused by diurnal and nocturnal pollinators. Both nocturnal and diurnal visitors were successful pollinators. However, flowers exposed only to nocturnal visitors produced less fruits than those exposed only to diurnal visitors. Thus, diurnal pollinators contribute more to seed production by J. curcas at the study site.

  19. Natural sex hormone cycles and gender differences in memory.

    Science.gov (United States)

    Otero Dadín, C; Rodríguez Salgado, D; Andrade Fernández, E

    2009-01-01

    To analyze gender differences in memory and the influence of the natural sex hormone cycles on it. A total of 20 men and 19 women were assessed with memory tests two times coinciding with two hormonal phases of the diurnal cycle of testosterone in men or menstrual cycle in women. It was observed that women perform better than men in delayed verbal memory as well as in immediate and delayed object recall, and men in digit span. It was also found that there was a significant effect of the hormonal cycles on verbal working memory, immediate object recall and on the spatial component of visuoconstructive memory. Finally, hormonal cycles determine the existence and direction of gender differences in verbal working memory, delayed object recall and in the spatial component of visuoconstructive memory. Natural sex hormone cycles seem to influence gender differences in some measurements of memory.

  20. Diurnal activity of the American Mink (Neovison vison in Central Spain

    Directory of Open Access Journals (Sweden)

    Pablo García

    2009-11-01

    Full Text Available <strong>Abstract> The American mink (Neovison vison is an invasive species in Spain and its population ecology is poorly understood. Diurnal activity was studied in a population of central Spain by means of direct observations. This activity peaked in summer and winter, mink being more active just after daybreak (06:00-08:00 and before dawn (16:00-18:00. Foraging (50% of observations; N = 146 and travelling (38.2%, were the main activities recorded during daylight. Mink were recorded as either in water or on land. In the latter, their distance from the water edge never exceeded 5.5 m. This pattern of daylight activity could be a mechanism for reducing potential interactions with nocturnal mammals sharing the same habitats. The success of culling campaigns could be increased by extending trapping sessions to daylight hours. <strong>Riassunto> <strong>Attività diurna del visone americano (Neovison visonM nella Spagna centrale. strong> L’ecologia dell’alloctono visone americano in Spagna è tuttora poco nota. Tramite osservazione diretta, è stata indagata l’incidenza della attività diurna in una popolazione della Spagna centrale. Tale attività è risultata più frequente in estate ed inverno, quando i visoni sono attivi nelle prime ore del giorno (06:00-08:00 e prima del tramonto (16:00-18:00. Le attività registrate più frequentemente sono state il foraggiamento (50% delle osservazioni, N = 146 e gli spostamenti (travelling, 38,2%. I visoni sono stati osservati indistintamente sia in acqua che a terra; in quest’ultimo caso la distanza dalla riva non è mai stata superiore a 5,5 m. Si ipotizza che l’attività diurna potrebbe essere un meccanismo per ridurre le interazioni con mammiferi prevalentemente notturni legati ai medesimi ambienti. In base ai risultati ottenuti, si suggerisce che il successo delle operazioni di controllo della specie potrebbe essere incrementato estendendo il

  1. Acute effects of diurnal temperature range on mortality in 8 Chinese cities.

    Science.gov (United States)

    Zhou, Xiaodan; Zhao, Ang; Meng, Xia; Chen, Renjie; Kuang, Xingya; Duan, Xiaoli; Kan, Haidong

    2014-09-15

    Diurnal temperature range (DTR) is a meteorological indicator closely associated with global climate change. There have been no multicity studies in China addressing the DTR-related health impact. We hypothesized that an increase of DTR is associated with higher daily mortality with a potential lag of effect, and investigated the acute effects of DTR on total, cardiovascular, and respiratory mortality in 8 large Chinese cities from 2001 to 2010. We first calculated city-specific effect of DTR in the full year, the cool season (November to the next April) and the warm season (May to October) separately using a semi-parametric generalized additive model; then we pooled the city-specific estimates with meta analysis. After adjusting for long-term and seasonal trends, temperature, relative humidity and air pollution levels, we found statistically significant associations between DTR and daily mortality, especially in cool seasons. A 1 °C increment of DTR on lag-day 1 corresponded to a 0.42% (95% CI, 0.14 to 0.70) increase in total non-accidental mortality, 0.45% (95% CI, 0.26 to 0.65) increase in cardiovascular mortality, and a 0.76% (95% CI, 0.24 to 1.29) increase in respiratory mortality in cool seasons. Deaths among females and elderly (≥ 65 years) were more strongly associated with DTR than among males and younger people (climate policies in the country. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Diurnal and Seasonal Cloud Base Patterns Highlight Small-Mountain Tropical Cloud Forest Vulnerability

    Science.gov (United States)

    Van Beusekom, A.; Gonzalez, G.; Scholl, M. A.

    2016-12-01

    The degree to which cloud immersion sustains tropical montane cloud forests (TMCFs) during rainless periods and the amount these clouds are affected by urban areas is not well understood, as cloud base is rarely quantified near mountains. We found that a healthy small-mountain TMCF in Puerto Rico had lowest cloud base during the mid-summer dry season. In addition, we observed that cloud bases were lower than the mountaintops as often in the winter dry season as in the wet seasons, based on 2.5 years of direct and 16 years of indirect observations. The low clouds during dry season appear to be explained by proximity to the oceanic cloud system where lower clouds are seasonally invariant in altitude and cover; along with orographic lifting and trade-wind control over cloud formation. These results suggest that climate change impacts on small-mountain TMCFs may not be limited to the dry season; changes in regional-scale patterns that cause drought periods during the wet seasons will likely have higher cloud base, and thus may threaten cloud water support to sensitive mountain ecosystems. Strong El Niño's can cause drought in Puerto Rico; we will report results from the summer of 2015 that examined El Niño effects on cloud base altitudes. Looking at regionally collected airport cloud data, we see indicators that diurnal urban effects may already be raising the low cloud bases.

  3. Modifiers of diurnal temperature range and mortality association in six Korean cities

    Science.gov (United States)

    Lim, Youn-Hee; Park, Ae Kyung; Kim, Ho

    2012-01-01

    Rapid temperature changes within a single day may be critical for populations vulnerable to thermal stress who have difficulty adjusting themselves behaviorally and physiologically. We hypothesized that diurnal temperature range (DTR) is associated with mortality, and that this association is modified by season and socioeconomic status (SES). We evaluated meteorological and mortality data from six metropolitan areas in Korea from 1992 to 2007. We applied generalized linear models (GLM) for quantifying the estimated effects of DTR on mortality after adjusting for mean temperature, dew point temperature, day of the week, and seasonal and long-term trends. Most areas showed a linear DTR-mortality relationship, with evidence of increasing mortality with increasing DTR. Deaths among the elderly (75 years or older), females, the less educated, and the non-hospital population were associated more strongly with DTR than with the corresponding categories. DTR was the greatest threat to vulnerable study populations, with greater influence in the fall season. DTR was found to be a predictor of mortality, and this relationship was modified by season and SES.

  4. Seasonal and diurnal variation of lightning activity over southern Africa and correlation with European whistler observations

    Directory of Open Access Journals (Sweden)

    A. B. Collier

    2006-03-01

    Full Text Available Lightning Imaging Sensor (LIS data have been analysed to ascertain the statistical pattern of lightning occurrence over southern Africa. The diurnal and seasonal variations are mapped in detail. The highest flash rates (107.2 km-2 y-1 occur close to the equator but maxima are also found over Madagascar (32.1 km-2 y-1 and South Africa (26.4 km-2 y-1. A feature of the statistics is a relatively steady contribution from over the ocean off the east coast of South Africa that appears to be associated with the Agulhas current. Lightning statistics are of intrinsic meteorological interest but they also relate to the occurrence of whistlers in the conjugate region. Whistler observations are made at Tihany, Hungary. Statistics reveal that the period of most frequent whistler occurrence does not correspond to the maximum in lightning activity in the conjugate region but is strongly influenced by ionospheric illumination and other factors. The whistler/flash ratio, R, shows remarkable variations during the year and has a peak that is narrowly confined to February and March.

  5. Diurnal Lhc gene expression is present in many but not all species of the plant kingdom.

    Science.gov (United States)

    Oberschmidt, O; Hücking, C; Piechulla, B

    1995-01-01

    The diurnal and circadian expression of light-harvesting genes (Lhc) is well documented for many plant species of the 'Angiospermae' division. Here we present the diurnal mRNA levels of species of the Gymnospermae, Pteridophyta, Bryophyta and Phycophyta divisions. Except for four Coniferophytina species, diurnal Lhc mRNA accumulation is detected in fern, moss and algae, supporting the idea that the concept of 'ciracadian clock'-controlled gene expression is an ancient process. Possible reasons why plants need the 'circadian clock' control mechanism are discussed.

  6. Using a 1-D model to reproduce the diurnal variability of SST

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, Jacob L.; Donlon, Craig J.

    2017-01-01

    preferred approach to bridge the gap between in situ and remotely sensed measurements and obtain diurnal warming estimates at large spatial scales is modeling of the upper ocean temperature. This study uses the one-dimensional General Ocean Turbulence Model (GOTM) to resolve diurnal signals identified from...... forcing fields and is able to resolve daily SST variability seen both from satellite and in situ measurements. As such, and due to its low computational cost, it is proposed as a candidate model for diurnal variability estimates....

  7. An estimate of monthly global emissions of anthropogenic CO2: Impact on the seasonal cycle of atmospheric CO2

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, D [Oak Ridge National Laboratory (ORNL); Mills, R [Oak Ridge National Laboratory (ORNL); Gregg, J [University of Maryland; Blasing, T J [ORNL; Hoffman, F [Oak Ridge National Laboratory (ORNL); Andres, Robert Joseph [ORNL; Devries, M [Oak Ridge National Laboratory (ORNL); Zhu, Z [NASA Goddard Space Flight Center; Kawa, S [NASA Goddard Space Flight Center

    2008-01-01

    Monthly estimates of the global emissions of anthropogenic CO2 are presented. Approximating the seasonal CO2 emission cycle using a 2-harmonic Fourier series with coefficients as a function of latitude, the annual fluxes are decomposed into monthly flux estimates based on data for the United States and applied globally. These monthly anthropogenic CO2 flux estimates are then used to model atmospheric CO2 concentrations using meteorological fields from the NASA GEOS-4 data assimilation system. We find that the use of monthly resolved fluxes makes a significant difference in the seasonal cycle of atmospheric CO2 in and near those regions where anthropogenic CO2 is released to the atmosphere. Local variations of 2-6 ppmv CO2 in the seasonal cycle amplitude are simulated; larger variations would be expected if smaller source-receptor distances could be more precisely specified using a more refined spatial resolution. We also find that in the midlatitudes near the sources, synoptic scale atmospheric circulations are important in the winter and that boundary layer venting and diurnal rectifier effects are more important in the summer. These findings have implications for inverse-modeling efforts that attempt to estimate surface source/sink regions especially when the surface sinks are colocated with regions of strong anthropogenic CO2 emissions.

  8. Diurnal modulation signal from dissipative hidden sector dark matter

    Directory of Open Access Journals (Sweden)

    R. Foot

    2015-09-01

    Full Text Available We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken U(1′ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength ϵ∼10−9. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large (≳10% for a wide range of parameters.

  9. Unravelling Diurnal Asymmetry of Surface Temperature in Different Climate Zones.

    Science.gov (United States)

    Vinnarasi, R; Dhanya, C T; Chakravorty, Aniket; AghaKouchak, Amir

    2017-08-04

    Understanding the evolution of Diurnal Temperature Range (DTR), which has contradicting global and regional trends, is crucial because it influences environmental and human health. Here, we analyse the regional evolution of DTR trend over different climatic zones in India using a non-stationary approach known as the Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method, to explore the generalized influence of regional climate on DTR, if any. We report a 0.36 °C increase in overall mean of DTR till 1980, however, the rate has declined since then. Further, arid deserts and warm-temperate grasslands exhibit negative DTR trends, while the west coast and sub-tropical forest in the north-east show positive trends. This transition predominantly begins with a 0.5 °C increase from the west coast and spreads with an increase of 0.25 °C per decade. These changes are more pronounced during winter and post-monsoon, especially in the arid desert and warm-temperate grasslands, the DTR decreased up to 2 °C, where the rate of increase in minimum temperature is higher than the maximum temperature. We conclude that both maximum and minimum temperature increase in response to the global climate change, however, their rates of increase are highly local and depend on the underlying climatic zone.

  10. Listening to music affects diurnal variation in muscle power output.

    Science.gov (United States)

    Chtourou, H; Chaouachi, A; Hammouda, O; Chamari, K; Souissi, N

    2012-01-01

    The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (pmusic warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Large diurnal temperature range increases bird sensitivity to climate change.

    Science.gov (United States)

    Briga, Michael; Verhulst, Simon

    2015-11-13

    Climate variability is changing on multiple temporal scales, and little is known of the consequences of increases in short-term variability, particularly in endotherms. Using mortality data with high temporal resolution of zebra finches living in large outdoor aviaries (5 years, 359.220 bird-days), we show that mortality rate increases almost two-fold per 1°C increase in diurnal temperature range (DTR). Interestingly, the DTR effect differed between two groups with low versus high experimentally manipulated foraging costs, reflecting a typical laboratory 'easy' foraging environment and a 'hard' semi-natural environment respectively. DTR increased mortality on days with low minimum temperature in the easy foraging environment, but on days with high minimum temperature in the semi-natural environment. Thus, in a natural environment DTR effects will become increasingly important in a warming world, something not detectable in an 'easy' laboratory environment. These effects were particularly apparent at young ages. Critical time window analyses showed that the effect of DTR on mortality is delayed up to three months, while effects of minimum temperature occurred within a week. These results show that daily temperature variability can substantially impact the population viability of endothermic species.

  12. Study on the Diurnal Variation of the Plasma Immunoreactive Glucagon

    International Nuclear Information System (INIS)

    Lee, Hong Kyu; Hong, Kee Suk; Kim, Byoung Kook; Koh, Chang Soon; Chung, June Key; Kim, Eui Chong

    1984-01-01

    It is well known that glucagon, like insulin, is very important in the moment-to-moment control of the homeostasis of glucose, and of amino acids. Glucagon has been shown to have potent glycogenolytic, gluconeogenic and lipolytic activities. Attention to its role in the pathogenesis of diabetes mellitus and hypoglycemia has been also advanced recently. To evaluate the diurnal variation of plasma glucagon concentration, we measured serum glucose, insulin, and plasma glucagon every 30 minutes or every hour in 7 normal Korean adults. Results were as follows: 1) Although plasma glucagon concentration showed wide individual variations, it had a tendency to decrease after meals. After lunch and dinner, plasma glucagon concentration had gradually declined and reached its nadir at postprandial 2-2.5 hours. The minimal level of plasma glucagon was at 4 A.M. 2) Serum insulin:plasma glucagon ratios were increased promptly after meals. Especially after lunch, its peak was prominent (3.65 ± 1. 95). The minimal level of serum insulin:plasma glucagon ratio appeared at 6 A.M.

  13. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.

    1991-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  14. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosol of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez Garcia, M.M.; Perez Pastor, R.M.; Bea, J.F.; Campos, A.; Gonzalez Diaz, D.

    1990-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled in the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. From these results, it has been tried to identify emission sources of the studied hydrocarbons. (Author). 10 refs

  15. Severity and Diurnal Improvement of Morning Stiffness Independently Associate with Tenosynovitis in Patients with Rheumatoid Arthritis.

    Science.gov (United States)

    Kobayashi, Yoshihisa; Ikeda, Kei; Nakamura, Takayuki; Yamagata, Mieko; Nakazawa, Takuya; Tanaka, Shigeru; Furuta, Shunsuke; Umibe, Takeshi; Nakajima, Hiroshi

    2016-01-01

    Although morning stiffness has long been recognized as a characteristic feature of rheumatoid arthritis (RA), it is no more included in the 2010 ACR/EULAR Classification Criteria or in the current major instruments for evaluating disease activity of RA. In this cross-sectional study, we aimed to determine the independent value and the optimal measurement of morning stiffness by clarifying the associations between morning stiffness and synovial inflammation. We enrolled 76 consecutive RA patients who underwent musculoskeletal ultrasound examination and agreed to participate in the study. In addition to asking the duration of morning stiffness, we asked patients to complete a diagram which represents the time course of their morning stiffness in the dominant hand. Based on this diagram, we calculated the severity and the diurnal improvement of morning stiffness. We also determined the activity of intra-articular synovitis in 11 joints and tenosynovitis in 8 tendons/tendon compartments in the same hand by using power Doppler (PD) ultrasound with a semiquantitative score (0-3). For intra-articular synovitis, swollen/tender joint counts more strongly correlated with total PD scores (ρ = 0.379-0.561, p ≤ 0.001) than did any parameters of morning stiffness (ρ = 0.217-0.314, p = 0.006-0.021). For tenosynovitis, however, the severity on awakening and the improvement of morning stiffness more strongly correlated with total PD scores (ρ = 0.503-0.561, p morning stiffness as factors that independently associate with the total tenosynovial PD score. Our data demonstrate a pathophysiological link between morning stiffness and tenosynovitis and also give an insight into the optimal measurement of morning stiffness. Our data support an independent value of evaluating morning stiffness in the management of RA.

  16. Impact of Diurnal Variation of Winds on Coastal Waves off South East Coast of India

    Directory of Open Access Journals (Sweden)

    P G Remya

    2013-09-01

    Full Text Available The land-sea breeze systems, the most interesting phenomena observed at coastal regions, have significant impact on the costal wave characteristics. Present study also focuses the diurnal variations of winds and its impact on wave parameters like significant wave height and mean wave period off Ennore port located in the south east coast of India The impact of the diurnal variation of winds on complex wave patterns in the coastal regions of Indian Ocean have been addressed earlier also. In the present study an attempt has been made to explore the impact of diurnal variation of winds on coastal waves using numerical model forced with European Centre for Medium Range Weather Forecasts (ECMWF and National Centre for Environmental Prediction (NCEP blended wind fields. It has been observed that most of the time, the ECMWF blended wind field reproduces the diurnal variation.

  17. Diurnal variation in glycogen phosphorylase activity in rat liver. A quantitative histochemical study

    NARCIS (Netherlands)

    Frederiks, W. M.; Marx, F.; Bosch, K. S.

    1987-01-01

    The diurnal variations of the glycogen content and of glycogen phosphorylase activity in periportal and pericentral areas of rat liver parenchyma have been analyzed in periodic acid Schiff (PAS)-stained cryostat sections using quantitative microdensitometry. Glycogen content and phosphorylase

  18. Diurnal Variation over the Tropical Monsoon Regions During Northern Summer 1991

    National Research Council Canada - National Science Library

    Jimenez, Greg

    1997-01-01

    This study examines diurnal variation of convection over western India, the Bay of Bengal, Indochina and the northern South China Sea during the 1991 northern summer monsoon using combined Japanese (GMS) and Indian (INSAT...

  19. Endocrine and metabolic diurnal rhythms in young adult men born small vs appropriate for gestational age

    DEFF Research Database (Denmark)

    Brøns, Charlotte; Saltbæk, Pernille N; Friedrichsen, Martin

    2016-01-01

    for 24 h, to measure levels of glucose, free fatty acids (FFA), triglycerides (TG), insulin, C-peptide, leptin, resistin, ghrelin, plasminogen activator inhibitor-1 (PAI-1), incretins (GLP-1 and GIP), and inflammatory markers (TNF-α and IL-6) in 13 young men born SGA and 11 young men born AGA. RESULTS......: Repeated measurements analyses were used to analyze the diurnal variations and differences between groups. The SGA subjects had increased 24-h glucose (P=0.03), glucagon (P=0.03) and resistin (P=0.003) levels with no difference in diurnal rhythms compared with AGA controls. We found significant diurnal...... exhibit elevated 24-h blood glucose, and plasma glucagon and resistin levels with no major differences in diurnal rhythms of these or other key metabolic hormones, substrates or inflammatory markers implicated in the origin of adiposity and T2D....

  20. Quasi-Biennial Oscillation signatures in the diurnal tidal winds over Cachoeira Paulista

    Science.gov (United States)

    Rodrigues de Araujo, Luciana; Jacobi, Christoph; Batista, Paulo; Lima, Lourivaldo

    2016-07-01

    The solar diurnal tidal plays an important role in the Mesosphere and Lower Thermosphere (MLT) region at low latitudes, in which its amplitude for horizontal winds maximizes around 20 degrees. The tides are excited in the lower atmosphere and stratosphere and can be affected by short and long-term local variations during their upward propagation. In this work, the meteor winds obtained over Cachoeira Paulista (22.7° S, 45.0° W), Brazil, have been used to investigate interannual variability in the amplitude of the diurnal tidal winds. The monthly diurnal tidal displays year to year variations. Amplitudes are strongest when the equatorial quasi-biennial oscillation (QBO) at the 30 mb level is eastward. This behavior can be observed in all seasons in the meridional component, whilst it is more clearly expressed during austral autumn in the zonal component, just when the diurnal tidal is strongest at this latitude.

  1. Corrigendum: Childhood Adversity, Self-Esteem, and Diurnal Cortisol Profiles Across the Life Span.

    Science.gov (United States)

    2018-01-01

    Original article: Zilioli, S., Slatcher, R. B., Chi, P., Li, X., Zhao, J., & Zhao, G. (2016). Childhood adversity, self-esteem, and diurnal cortisol profiles across the life span. Psychological Science, 27, 1249-1265. doi:10.1177/0956797616658287.

  2. Seasonal and diurnal variability of thermal structure in the coastal waters off Visakhapatnam

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, B.P.; RameshBabu, V.; Chandramohan, P.

    Seasonal and diurnal variability of thermal structure in the coastal waters off Visakhapatnam has been examined in relation to the flow field and surface winds utilizing the hourly data of temperature and currents taken at a fixed location over a...

  3. Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis.

    Science.gov (United States)

    Adam, Emma K; Quinn, Meghan E; Tavernier, Royette; McQuillan, Mollie T; Dahlke, Katie A; Gilbert, Kirsten E

    2017-09-01

    Changes in levels of the stress-sensitive hormone cortisol from morning to evening are referred to as diurnal cortisol slopes. Flatter diurnal cortisol slopes have been proposed as a mediator between chronic psychosocial stress and poor mental and physical health outcomes in past theory and research. Surprisingly, neither a systematic nor a meta-analytic review of associations between diurnal cortisol slopes and health has been conducted to date, despite extensive literature on the topic. The current systematic review and meta-analysis examined associations between diurnal cortisol slopes and physical and mental health outcomes. Analyses were based on 179 associations from 80 studies for the time period up to January 31, 2015. Results indicated a significant association between flatter diurnal cortisol slopes and poorer health across all studies (average effect size, r=0.147). Further, flatter diurnal cortisol slopes were associated with poorer health in 10 out of 12 subtypes of emotional and physical health outcomes examined. Among these subtypes, the effect size was largest for immune/inflammation outcomes (r=0.288). Potential moderators of the associations between diurnal cortisol slopes and health outcomes were examined, including type of slope measure and study quality indices. The possible roles of flatter slopes as either a marker or a mechanism for disease etiology are discussed. We argue that flatter diurnal cortisol slopes may both reflect and contribute to stress-related dysregulation of central and peripheral circadian mechanisms, with corresponding downstream effects on multiple aspects of biology, behavior, and health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Medical Devices; Ophthalmic Devices; Classification of the Diurnal Pattern Recorder System. Final order.

    Science.gov (United States)

    2016-05-31

    The Food and Drug Administration (FDA) is classifying the diurnal pattern recorder system into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the diurnal pattern recorder system's classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  5. Dry season and diurnal surveys of phylloplane fungi of Hevea brasiliensis in Nigeria

    OpenAIRE

    J. A. Okhuoya; C. O. Ahweyevu

    2014-01-01

    Monthly and diurnal variation of phylloplane fungi of rubber (Hevea brasiliensis) leaves were studied over a period of four months in the dry season, using two culturing methods. Composite fungal population was the highest in April and the lowest in February. Serial dilution method recorded the higher number of fungal spores than ballistospore method. Mature leaves were found to have more fungal spores than premature and young leaves. Spore concentration on the leaves showed diurnal periodici...

  6. Long-term stability of diurnal salivary cortisol and alpha-amylase secretion patterns.

    Science.gov (United States)

    Skoluda, Nadine; La Marca, Roberto; Gollwitzer, Mario; Müller, Andreas; Limm, Heribert; Marten-Mittag, Birgitt; Gündel, Harald; Angerer, Peter; Nater, Urs M

    2017-06-01

    This study aimed to investigate long-term stability and variability of diurnal cortisol and alpha-amylase patterns. Diurnal cortisol and alpha-amylase secretion patterns were assessed on a single workday with three waves of measurement across a total time period of 24months in 189 participants. Separate hierarchical linear models were analyzed, with and without a number of potential predictor variables (age, BMI, smoking, chronic stress, stress reactivity). While low long-term stability was found in diurnal cortisol, the stability of diurnal alpha-amylase was moderate across the time period of 24months. Several predictor variables had a positive impact on diurnal cortisol and alpha-amylase secretion patterns averaged across waves. Our findings underpin the notion that long-term stability is not necessarily warranted in longitudinal studies. It is important to choose an appropriate study design when attempting to disentangle clinically and biologically relevant changes from naturally occurring variations in diurnal cortisol and alpha-amylase. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Coastal-trapped behavior of the diurnal internal tide at O'ahu, Hawai'i

    Science.gov (United States)

    Smith, Katharine A.; Merrifield, Mark A.; Carter, Glenn S.

    2017-05-01

    The influence of rotation on the structure and propagation of internal tides around O'ahu, Hawai'i is investigated using in situ observations and a tidally forced, primitive equation model with realistic bathymetry and stratification. Particular attention is given to the diurnal internal tide, which largely has been de-emphasized in previous studies of the region because of the dominance of the semidiurnal internal tide but has been determined by recent studies to be a significant contributor to baroclinic variability. Though both diurnal and semidiurnal internal tides are generated primarily over Ka'ena Ridge to the northwest of the island, the diurnal internal tide propagates clockwise around the island as an imperfectly trapped wave, while the semidiurnal internal tide propagates away from the ridge, unaffected by rotation. The diurnal and semidiurnal internal tides fall into the superinertial frequency range; however, the diurnal frequency apparently is sufficiently close to inertial (˜ 1.4f) for rotation to affect internal tide propagation. The in situ observations support the model finding that diurnal trapping provides the primary source of baroclinic variability along the eastern coast of the island, a stretch of coastline otherwise sheltered from the internal tide energy generated over the Hawaiian Ridge. The findings in Hawai'i suggest that coastal trapping of superinertial internal tides may be a significant source of variability and mixing in other nearshore systems around the world.

  8. Analysis of the Diurnal Variation of the Global Electric Circuit Obtained From Different Numerical Models

    Science.gov (United States)

    Jánský, Jaroslav; Lucas, Greg M.; Kalb, Christina; Bayona, Victor; Peterson, Michael J.; Deierling, Wiebke; Flyer, Natasha; Pasko, Victor P.

    2017-12-01

    This work analyzes different current source and conductivity parameterizations and their influence on the diurnal variation of the global electric circuit (GEC). The diurnal variations of the current source parameterizations obtained using electric field and conductivity measurements from plane overflights combined with global Tropical Rainfall Measuring Mission satellite data give generally good agreement with measured diurnal variation of the electric field at Vostok, Antarctica, where reference experimental measurements are performed. An approach employing 85 GHz passive microwave observations to infer currents within the GEC is compared and shows the best agreement in amplitude and phase with experimental measurements. To study the conductivity influence, GEC models solving the continuity equation in 3-D are used to calculate atmospheric resistance using yearly averaged conductivity obtained from the global circulation model Community Earth System Model (CESM). Then, using current source parameterization combining mean currents and global counts of electrified clouds, if the exponential conductivity is substituted by the conductivity from CESM, the peak to peak diurnal variation of the ionospheric potential of the GEC decreases from 24% to 20%. The main reason for the change is the presence of clouds while effects of 222Rn ionization, aerosols, and topography are less pronounced. The simulated peak to peak diurnal variation of the electric field at Vostok is increased from 15% to 18% from the diurnal variation of the global current in the GEC if conductivity from CESM is used.

  9. Diurnal variation in soil respiration under different land uses on Taihang Mountain, North China

    Science.gov (United States)

    Liu, Xiuping; Zhang, Wanjun; Zhang, Bin; Yang, Qihong; Chang, Jianguo; Hou, Ke

    2016-01-01

    The aim of this paper is to evaluate the diurnal variation in soil respiration under different land use types on Taihang Mountain, North China, and to understand its response to environmental factors (e.g., soil temperature and moisture) and forest management. Diurnal variations in soil respiration from plantations (Robinia pseudoacacia, Punica granatum, and Ziziphus jujuba), naturally regenerated forests (Vitex negundo var. heterophylla), grasslands (Bothriochloa ischaemum), and farmlands (winter wheat/summer maize) were measured using an LI-8100 automated soil CO2 flux system from May 2012 to April 2013. The results indicated that land use type had a significant effect on the diurnal variation of soil respiration. The diurnal soil respiration from farmlands was highest, followed by Ziziphus jujube, R. pseudoacacia, P. granatum, the lower soil CO2 efflux was found from B. ischaemum and V. negundo var. heterophylla. The diurnal soil respiration across different land use types was significantly affected by soil temperature and moisture, and their interaction. Precipitation-stimulated soil respiration increased more in soil with low water content and less in soil with high water content. The lower diurnal soil respiration from naturally regenerated forests suggests that naturally regenerated vegetation is the optimal vegetation type for reducing global warming.

  10. Dedicated Low Latitude Diurnal CO2 Frost Observation Campaigns by the Mars Climate Sounder

    Science.gov (United States)

    Piqueux, S.; Kass, D. M.; Kleinboehl, A.; Hayne, P. O.; Heavens, N. G.; McCleese, D. J.; Schofield, J. T.; Shirley, J. H.

    2017-12-01

    In December 2016 (Ls≈280, MY33) and July 2017 (Ls≈30, MY34), the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) conducted two distinct observation campaigns. The first one aimed at 1) confirming the presence of low latitude diurnal CO2 frost on Mars, and 2) refining the estimated mass of carbon dioxide condensed at the surface, whereas the second campaign was designed to 3) search for temporally and spatially varying spectral characteristics indicative of frost properties (i.e., crystal size, contamination, etc.) and relationship to the regolith. To meet these goals, MCS acquired thermal infrared observations of the surface and atmosphere at variable local times (≈1.70-3.80 h Local True Solar Time) and in the 10°-50°N latitude band where very low thermal inertia material (<< 100 Jm-2K-1s-0.5) is present. Atmospherically corrected surface brightness temperatures were retrieved in a wavelength region around 32 μm (MCS channel B1) as well as at 12 μm, 16 μm and 22 μm (MCS channels A4, A1, A5) where possible. A preliminary analysis of the data suggests a good general agreement between these new observations and earlier predictions in terms of frost distribution and spectral properties. In addition, pre-frost deposition surface cooling rates are found to be consistent with those predicted by numerical models (i.e., 1-2K per hour). Finally, we observe buffered surface temperatures near the local frost point, indicating a surface emissivity ≈1. (i.e., optically thin frost layers, or dust contaminated frost, or slab-like ice) and no discernable frost metamorphism. We will present a detailed analysis of these new and unique observations, and elaborate on the potential relationship between the regolith and this recurring frost cycle.

  11. Solar-forced diurnal regulation of cave drip rates via phreatophyte evapotranspiration

    Directory of Open Access Journals (Sweden)

    K. Coleborn

    2016-11-01

    Full Text Available We present results of a detailed study of drip rate variations at 12 drip discharge sites in Glory Hole Cave, New South Wales, Australia. Our novel time series analysis, using the wavelet synchrosqueezed transform, reveals pronounced oscillations at daily and sub-daily frequencies occurring in 8 out of the 12 monitored sites. These oscillations were not spatially or temporally homogenous, with different drip sites exhibiting such behaviour at different times of year in different parts of the cave. We test several hypotheses for the cause of the oscillations, including variations in pressure gradients between karst and cave due to cave breathing effects or atmospheric and earth tides, variations in hydraulic conductivity due to changes in viscosity of water with daily temperature oscillations, and solar-driven daily cycles of vegetative (phreatophytic transpiration. We conclude that the only hypothesis consistent with the data and hydrologic theory is that daily oscillations are caused by solar-driven pumping by phreatophytic trees which are abundant at the site. The daily oscillations are not continuous and occur sporadically in short bursts (2–14 days throughout the year due to non-linear modification of the solar signal via complex karst architecture. This is the first indirect observation leading to the hypothesis of tree water use in cave drip water. It has important implications for karst hydrology in regards to developing a new protocol to determine the relative importance of trends in drip rate, such as diurnal oscillations, and how these trends change over timescales of weeks to years. This information can also be used to infer karst architecture. This study demonstrates the importance of vegetation on recharge dynamics, information that will inform both process-based karst models and empirical estimation approaches. Our findings support a growing body of research exploring the impact of trees on speleothem paleoclimate proxies.

  12. Changes in the diurnal rhythms of cortisol, melatonin, and testosterone after 2, 4, and 7 consecutive night shifts in male police officers.

    Science.gov (United States)

    Jensen, Marie Aarrebo; Hansen, Åse Marie; Kristiansen, Jesper; Nabe-Nielsen, Kirsten; Garde, Anne Helene

    2016-08-11

    Night work is associated with a large range of acute health problems and possibly also health consequences in the long run. Yet, only very few field studies specifically investigate the effects of consecutive night shift on key physiological regulatory systems. In this field study, we investigated the effects of consecutive night shifts on three hormones, melatonin, cortisol, and testosterone, among police officers at work. More specifically, the aim was to investigate how the diurnal rhythms of melatonin, cortisol, and testosterone responded to two, four, and seven consecutive night shifts and a corresponding number of days for recovery. The study was part of the "In the Middle of the Night" project and included 73 male police officers from five different police districts. The participants were exposed to three intervention conditions: "2+2": two consecutive night shifts followed by two consecutive day recovery days; "4+4": four consecutive night shifts followed by four consecutive recovery days; "7+7": seven consecutive night shifts followed by seven consecutive recovery days. On the last day with night shift and the last recovery day in each intervention, the participants collected saliva samples every 4th hour when awake. The diurnal rhythms of melatonin, cortisol, and testosterone were all affected differently by an increasing number of consecutive night shifts: the amplitude of the melatonin rhythm was suppressed by 4.9% per day (95% CI 1.4-8.2% per day; p = 0.006). The diurnal rhythm of cortisol phase was delayed with an increasing number of night shifts by 33 min/day (95% CI 18-48 min per day; p ≤ 0.001), but did not show any changes in amplitude. For the diurnal rhythm of testosterone, there was no effect of the number of consecutive night shifts and the diurnal rhythm completely followed the sleep/wake cycle. We found that there were no differences in the rhythms of melatonin, cortisol, and testosterone after 2, 4, and 7 recovery days, respectively. In

  13. Diurnal and seasonal variability of rainfall in the sub-Sahel as seen from observations, satellites and a numerical model

    Science.gov (United States)

    Pinker, R. T.; Zhao, Y.; Akoshile, C.; Janowiak, J.; Arkin, P.

    2006-04-01

    Several climatic parameters are observed at the campus of the University of Ilorin, Ilorin, Nigeria in sub-Sahel Africa. This climatically important region is in the desert transition zone between the Sahara and the savanna of upper Nigeria and is influenced by the dusty Harmattan wind. It is characterized by persistent conditions with high aerosol loading as well as intense dust outbreaks that affect the local climate. The region is under the influence of the West African Monsoon (WAM) which has exhibited a dramatic change from wet conditions in the 50s and 60s to much drier conditions in the 70s, 80s and 90s. Observations at the Ilorin site were established to provide the Earth Observing System (EOS) Community with high quality climatic data, in particular, related to radiative fluxes and aerosols. The station is located in a region with extreme environmental conditions that are not common at other sites around the globe. For example, at Ilorin observed is the highest aerosol optical depth in the AErosol RObotic NETwork (AERONET) and the site is frequented by biomass burning during the dry season, thus adding new radiative effects to the dust aerosols (Pinker et al., 2001; Pandithurai et al., 2001; Holben et al., 2001, Smirnov et al., 2002). Biomass burning in savanna and forest ecosystems over Africa is believed to contribute about 20% to the global biomass burning. Dynamical models to predict WAM are not accurate in West Africa and tropical Atlantic regions, and are unable to simulate fundamental characteristics of rainfall (diurnal, seasonal and annual cycles). In this study we present an analysis of the diurnal and seasonal variability for several years of rainfall observations. Comparison is made with the output of a numerical model and satellite based estimates. It was found that two observed relative peaks in the annual rainfall distribution are seen in the satellite data but are not detected by the numerical model. It was also shown that the satellite

  14. Diurnal temperature range over Europe between 1950 and 2005

    Directory of Open Access Journals (Sweden)

    K. Makowski

    2008-11-01

    Full Text Available It has been widely accepted that diurnal temperature range (DTR decreased on a global scale during the second half of the twentieth century. Here we show however, that the long-term trend of annual DTR has reversed from a decrease to an increase during the 1970s in Western Europe and during the 1980s in Eastern Europe. The analysis is based on the high-quality dataset of the European Climate Assessment and Dataset Project, from which we selected approximately 200 stations covering the area bordered by Iceland, Algeria, Turkey and Russia for the period 1950 to 2005. We investigate national and regional annual means as well as the pan-European mean with respect to trends and reversal periods. 17 of the 24 investigated regions including the pan-European mean show a statistical significant increase of DTR since 1990 at the latest. Of the remaining 7 regions, two show a non-significant increase, three a significant decrease and two no significant trend. Changes in DTR are affected by both surface shortwave and longwave radiation, the former of which has undergone a change from dimming to brightening in the period considered. Consequently, we discuss the connections between DTR, shortwave radiation and sulfur emissions which are thought to be amongst the most important factors influencing the incoming solar radiation through the primary and secondary aerosol effect. We find reasonable agreement between trends in SO2 emissions, radiation and DTR in areas affected by high pollution. Consequently, we conclude that the trends in DTR could be mostly determined by changes in emissions and the associated changes in incoming solar radiation.

  15. Diurnal thermal analysis of microencapsulated PCM-concrete composite walls

    International Nuclear Information System (INIS)

    Thiele, Alexander M.; Sant, Gaurav; Pilon, Laurent

    2015-01-01

    Highlights: • Transient heat conduction across microencapsulated PCM-concrete walls was simulated. • Equivalent homogeneous wall with effective thermal properties was rigorously derived. • Adding PCM to the wall increases daily energy savings and delays peak thermal load. • Energy savings is maximum when PCM melting temperature equals indoor temperature. • Energy savings are limited in extreme climates but time delay can be large. - Abstract: This paper examines the benefits of adding microencapsulated phase change material (PCM) to concrete used in building envelopes to reduce energy consumption and costs. First, it establishes that the time-dependent thermal behavior of microencapsulated PCM-concrete composite walls can be accurately predicted by an equivalent homogeneous wall with appropriate effective thermal properties. The results demonstrate that adding microencapsulated PCM to concrete resulted in a reduction and a time-shift in the maximum heat flux through the composite wall subjected to diurnal sinusoidal outdoor temperature and solar radiation heat flux. The effects of the PCM volume fraction, latent heat of fusion, phase change temperature and temperature window, and outdoor temperature were evaluated. Several design rules were established including (i) increasing the PCM volume fraction and/or enthalpy of phase change increased the energy flux reduction and the time delay, (ii) the energy flux reduction was maximized when the PCM phase change temperature was close to the desired indoor temperature, (iii) the optimum phase change temperature to maximize the time delay increased with increasing average outdoor temperature, (iv) in extremely hot or cold climates, the thermal load could be delayed even though the reduction in daily energy flux was small, and (v) the choice of phase change temperature window had little effect on the energy flux reduction and on the time delay. This analysis can serve as a framework to design PCM composite walls

  16. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  17. Glacial cycles

    DEFF Research Database (Denmark)

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexi...

  18. CYCLE CONTROL

    African Journals Online (AJOL)

    changed to gestodene. Although large- scale comparative trials are needed to confirm this finding, evidence suggests that cycle control with gestodene is better than for monophasic preparations containing desogestrel, norgestimate or levonorgestrel,10 as well as for levonorg- estrel-or norethisterone-containing triphasics.

  19. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  20. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  1. Summertime diurnal variations in the isotopic composition of atmospheric nitrogen dioxide at a small midwestern United States city

    Science.gov (United States)

    Walters, Wendell W.; Fang, Huan; Michalski, Greg

    2018-04-01

    The nitrogen and oxygen stable isotopes (δ15N & δ18O) of nitrogen oxides (NOx = nitric oxide (NO) + nitrogen dioxide (NO2)) may be a useful tool for partitioning NOx emission sources and for evaluating NOx photochemical cycling, but few measurements of in situ NOx exist. In this study, we have collected and characterized the diurnal variability in δ15N and δ18O of NO2 from ambient air at a small Midwestern city (West Lafayette, IN, USA, 40.426° N, 86.908° W) between July 7 to August 5, 2016, using an active sampling technique. Large variations were observed in both δ15N(NO2) and δ18O(NO2) that ranged from -31.4 to 0.4‰ and 41.5-112.5‰, respectively. Daytime averages were -9.2 ± 5.7‰ (x̅ ± 1σ) and 86.5 ± 14.1‰ (n = 11), while nighttime averages were -13.4 ± 7.3‰ and 56.3 ± 7.1‰ (n = 12) for δ15N(NO2) and δ18O(NO2), respectively. The large variability observed in δ15N(NO2) is predicted to be driven by changing contributions of local NOx emission sources, as calculated isotope effects predict a minor impact on δ15N(NO2) relative to δ15N(NOx) that is generally less than 2.5‰ under the sample collection conditions of high ozone concentration ([O3]) relative to [NOx]. A statistical δ15N mass-balance model suggests that traffic-derived NOx is the main contributor to the sampling site (0.52 ± 0.22) with higher relative contribution during the daytime (0.58 ± 0.19) likely due to higher traffic volume than during the nighttime (0.47 ± 0.22). The diurnal cycle observed in δ18O(NO2) is hypothesized to be a result of the photochemical cycling of NOx that elevates δ18O(NO2) during the daytime relative to the nighttime. Overall, this data suggests the potential to use δ15N(NO2) for NOx source partitioning under environmental conditions of high [O3] relative to [NOx] and δ18O(NO2) for evaluating VOC-NOx-O3 chemistry.

  2. Seeking Augmented Information Content Concerning Diurnal Precipitation Achieved by Combining TRMM-PR and CloudSat-CPR Radar Data Sets

    Science.gov (United States)

    Smith, Eric A.; Kuo, Kwo-Sen; Carty, Hezekiah

    2008-01-01

    The CloudSat satellite's Cloud Profiling Radar (CPR) is a highly sensitive 94 GHz (W-band) nadir viewing radar system flown in retrograde sun synchronous orbit useful for determining the vertical structure of cloud hydrometeors down to sensitivity of approx. -30 dBZ reflectivity factor. Given this sensitivity, it is possible to unambiguously measure precipitation rates in clouds over a spectrum extending from approx. 0.08 - 3.0 mm hr (sup -1) down to altitudes of 0.5 km with approx.0.25 km vertical binning. This enables an effective means to measure a great deal of the drizzle and light rain spectrum. However, because of its near-polar sunsynchronous orbit, CloudSat cannot sample the diurnal cycle of precipitation, nor with its nadir-only CPR view can it obtain a high duty cycle in sampling precipitation at fixed local times over fixed positions. On the other hand, the TRMM satellite, which is flown in a non-sunsynchronous 35-degree inclined orbit carrying the 13.8 GHz KU-band Precipitation Radar (PR) scanning through nadir over an approx. 225 km swath, can sample both the diurnal cycle and with a much improved duty cycle relative to CloudSat. Moreover, the PR and CPR have the same 0.25 km vertical binning capability. The PR's greatest shortcoming is its approx. +17 dBZ sensitivity, which eliminates the possibility of measuring rain rates below -0.3-0.5 mm hr(sup -1), which can involve rainfall accumulations of up to 50% of the total over some regions. This begs the question of whether by combining CPR and PR data sets, whether it is possible to obtain an augmented measurement of the diurnal precipitation cycle. By collecting complimentary datasets during CloudSat and TRMM satellite orbit crossings within a delta t = 45-min proximity window, it is possible to demonstrate that whenever TRMM detects a precipitation signal, the correlations along the vertical axis between the reflectivities acquired from the CPR and PR are in inverse proportion to the magnitude of the

  3. Strong sum distance in fuzzy graphs.

    Science.gov (United States)

    Tom, Mini; Sunitha, Muraleedharan Shetty

    2015-01-01

    In this paper the idea of strong sum distance which is a metric, in a fuzzy graph is introduced. Based on this metric the concepts of eccentricity, radius, diameter, center and self centered fuzzy graphs are studied. Some properties of eccentric nodes, peripheral nodes and central nodes are obtained. A characterisation of self centered complete fuzzy graph is obtained and conditions under which a fuzzy cycle is self centered are established. We have proved that based on this metric, an eccentric node of a fuzzy tree G is a fuzzy end node of G and a node is an eccentric node of a fuzzy tree if and only if it is a peripheral node of G and the center of a fuzzy tree consists of either one or two neighboring nodes. The concepts of boundary nodes and interior nodes in a fuzzy graph based on strong sum distance are introduced. Some properties of boundary nodes, interior nodes and complete nodes are studied.

  4. Diurnal Variation of Hormonal and Lipid Biomarkers in a Molecular Epidemiology-Like Setting.

    Directory of Open Access Journals (Sweden)

    Linda W M van Kerkhof

    Full Text Available Many molecular epidemiology studies focusing on high prevalent diseases, such as metabolic disorders and cancer, investigate metabolic and hormonal markers. In general, sampling for these markers can occur at any time-point during the day or after an overnight fast. However, environmental factors, such as light exposure and food intake might affect the levels of these markers, since they provide input for the internal time-keeping system. When diurnal variation is larger than the inter-individual variation, time of day should be taken into account. Importantly, heterogeneity in diurnal variation and disturbance of circadian rhythms among a study population might increasingly occur as a result of our increasing 24/7 economy and related variation in exposure to environmental factors (such as light and food.The aim of the present study was to determine whether a set of often used biomarkers shows diurnal variation in a setting resembling large molecular epidemiology studies, i.e., non-fasted and limited control possibilities for other environmental influences.We show that markers for which diurnal variation is not an issue are adrenocorticotropic hormone, follicle stimulating hormone, estradiol and high-density lipoprotein. For all other tested markers diurnal variation was observed in at least one gender (cholesterol, cortisol, dehydroepiandrosterone sulfate, free fatty acids, low-density lipoprotein, luteinizing hormone, prolactin, progesterone, testosterone, triglycerides, total triiodothyronine and thyroid-stimulating hormone or could not reliably be detected (human growth hormone.Thus, studies investigating these markers should take diurnal variation into account, for which we provide some options. Furthermore, our study indicates the need for investigating diurnal variation (in literature or experimentally before setting up studies measuring markers in routine and controlled settings, especially since time-of-day likely matters for many more

  5. Seasonal and diurnal variations of atmospheric mercury across the US determined from AMNet monitoring data

    Directory of Open Access Journals (Sweden)

    X. Lan

    2012-11-01

    Full Text Available Speciated atmospheric mercury observations collected over the period from 2008 to 2010 at the Environmental Protection Agency and National Atmospheric Deposition Program Atmospheric Mercury Network sites (AMNet were analyzed for its spatial, seasonal, and diurnal characteristics across the US. Median values of gaseous elemental mercury (GEM, gaseous oxidized mercury (GOM and particulate bound mercury (PBM at 11 different AMNet sites ranged from 148–226 ppqv (1.32–2.02 ng m−3, 0.05–1.4 ppqv (0.47–12.4 pg m−3 and 0.18–1.5 ppqv (1.61–13.7 pg m−3, respectively. Common characteristics of these sites were the similar median levels of GEM as well as its seasonality, with the highest mixing ratios occurring in winter and spring and the lowest in fall. However, discernible differences in monthly average GEM were as large as 30 ppqv, which may be caused by sporadic influence from local emission sources. The largest diurnal variation amplitude of GEM occurred in the summer. Seven rural sites displayed similar GEM summer diurnal patterns, in that the lowest levels appeared in the early morning, and then the GEM mixing ratio increased after sunrise and reached its maxima at noon or in the early afternoon. Unlike GEM, GOM exhibited higher mixing ratios in spring and summer. The largest diurnal variation amplitude of GOM occurred in spring for most AMNet sites. The GOM diurnal minima appeared before sunrise and maxima appeared in the afternoon. The increased GOM mixing ratio in the afternoon indicated a photochemically driven oxidation of GEM resulting in GOM formation. PBM exhibited diurnal fluctuations in summertime. The summertime PBM diurnal pattern displayed daily maxima in the early afternoon and lower mixing ratios at night, implying photochemical production of PBM in summer.

  6. Computational Fluid Dynamics Modelling of the Diurnal Variation of Flow in a Street Canyon

    Science.gov (United States)

    Kwak, Kyung-Hwan; Baik, Jong-Jin; Lee, Sang-Hyun; Ryu, Young-Hee

    2011-10-01

    Urban surface and radiation processes are incorporated into a computational fluid dynamics (CFD) model to investigate the diurnal variation of flow in a street canyon with an aspect ratio of 1. The developed CFD model predicts surface and substrate temperatures of the roof, walls, and road. One-day simulations are performed with various ambient wind speeds of 2, 3, 4, 5, and 6 ms-1, with the ambient wind perpendicular to the north-south oriented canyon. During the day, the largest maximum surface temperature for all surfaces is found at the road surface for an ambient wind speed of 3 ms-1 (56.0°C). Two flow regimes are identified by the vortex configuration in the street canyon. Flow regime I is characterized by a primary vortex. Flow regime II is characterized by two counter-rotating vortices, which appears in the presence of strong downwind building-wall heating. Air temperature is relatively low near the downwind building wall in flow regime I and inside the upper vortex in flow regime II. In flow regime II, the upper vortex expands with increasing ambient wind speed, thus enlarging the extent of cool air within the canyon. The canyon wind speed in flow regime II is proportional to the ambient wind speed, but that in flow regime I is not. For weak ambient winds, the dependency of surface sensible heat flux on the ambient wind speed is found to play an essential role in determining the relationship between canyon wind speed and ambient wind speed.

  7. Reassessing changes in diurnal temperature range: A new data set and characterization of data biases

    Science.gov (United States)

    Thorne, P. W.; Menne, M. J.; Williams, C. N.; Rennie, J. J.; Lawrimore, J. H.; Vose, R. S.; Peterson, T. C.; Durre, I.; Davy, R.; Esau, I.; Klein-Tank, A. M. G.; Merlone, A.

    2016-05-01

    It has been a decade since changes in diurnal temperature range (DTR) globally have been assessed in a stand-alone data analysis. The present study takes advantage of substantively improved basic data holdings arising from the International Surface Temperature Initiative's databank effort and applies the National Centers for Environmental Information's automated pairwise homogeneity assessment algorithm to reassess DTR records. It is found that breakpoints are more prevalent in DTR than other temperature elements and that the resulting adjustments have a broader distribution. This strongly implies that there is an overarching tendency, across the global meteorological networks, for nonclimatic artifacts to impart either random or anticorrelated rather than correlated biases in maximum and minimum temperature series. Future homogenization efforts would likely benefit from simultaneous consideration of DTR and maximum and minimum temperatures, in addition to average temperatures. Estimates of change in DTR are relatively insensitive to whether adjustments are calculated directly or inferred from adjustments returned for the maximum and minimum temperature series. The homogenized series exhibit a reduction in DTR since the midtwentieth century globally (-0.044 K/decade). Adjustments serve to approximately halve the long-term global reduction in DTR in the basic "raw" data. Most of the estimated DTR reduction occurred over 1960-1980. In several regions DTR has apparently increased over 1979-2012, while globally it has exhibited very little change (-0.016 K/decade). Estimated changes in DTR are an order of magnitude smaller than in maximum and minimum temperatures, which have both been increasing rapidly on multidecadal timescales (0.186 K/decade and 0.236 K/decade, respectively, since the midtwentieth century).

  8. What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes.

    Science.gov (United States)

    Burkart, Katrin; Kinney, Patrick L

    2017-06-01

    Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI = 0.86-2.54%) per 1 °C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI = 0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

  9. Diurnal activity budgeting of Large Whistling Teal Dendrocygna bicolor (Vieillot, 1816 (Anseriformes: Anatidae in Deepor Beel wetlands, Assam, India

    Directory of Open Access Journals (Sweden)

    J. Das

    2011-12-01

    Full Text Available Diurnal activity budgets of the Large Whistling Teal Dendrocygna bicolor were quantified in Deepor Beel wetlands from March 2007 to January 2008. The study revealed that the Large Whistling Teal utilized 36.1% of time in resting, 37.1% in locomotion, 21.8% of diurnal time in feeding and 3.9% of diurnal time for preening activity. The teal spent <1% time in each, of alert and aggressive behaviours.

  10. Fuel cycle

    International Nuclear Information System (INIS)

    Bahm, W.

    1989-01-01

    The situation of the nuclear fuel cycle for LWR type reactors in France and in the Federal Republic of Germany was presented in 14 lectures with the aim to compare the state-of-the-art in both countries. In addition to the momentarily changing fuilds of fuel element development and fueling strategies, the situation of reprocessing, made interesting by some recent developmnts, was portrayed and differences in ultimate waste disposal elucidated. (orig.) [de

  11. Changes in diurnal temperature range and national cereal yields

    Energy Technology Data Exchange (ETDEWEB)

    Lobell, D

    2007-04-26

    Models of yield responses to temperature change have often considered only changes in average temperature (Tavg), with the implicit assumption that changes in the diurnal temperature range (DTR) can safely be ignored. The goal of this study was to evaluate this assumption using a combination of historical datasets and climate model projections. Data on national crop yields for 1961-2002 in the 10 leading producers of wheat, rice, and maize were combined with datasets on climate and crop locations to evaluate the empirical relationships between Tavg, DTR, and crop yields. In several rice and maize growing regions, including the two major nations for each crop, there was a clear negative response of yields to increased DTR. This finding reflects a nonlinear response of yields to temperature, which likely results from greater water and heat stress during hot days. In many other cases, the effects of DTR were not statistically significant, in part because correlations of DTR with other climate variables and the relatively short length of the time series resulted in wide confidence intervals for the estimates. To evaluate whether future changes in DTR are relevant to crop impact assessments, yield responses to projected changes in Tavg and DTR by 2046-2065 from 11 climate models were estimated. The mean climate model projections indicated an increase in DTR in most seasons and locations where wheat is grown, mixed projections for maize, and a general decrease in DTR for rice. These mean projections were associated with wide ranges that included zero in nearly all cases. The estimated impacts of DTR changes on yields were generally small (<5% change in yields) relative to the consistently negative impact of projected warming of Tavg. However, DTR changes did significantly affect yield responses in several cases, such as in reducing US maize yields and increasing India rice yields. Because DTR projections tend to be positively correlated with Tavg, estimates of yields

  12. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  13. Remote detection of water stress conditions via a diurnal photochemical reflectance index (PRI) improves yield prediction in rainfed wheat

    Science.gov (United States)

    Magney, T. S.; Vierling, L. A.; Eitel, J.

    2014-12-01

    Employing remotely sensed techniques to quantify the existence and magnitude of midday photosynthetic downregulation using the photochemical reflectance index (PRI) may reveal new information about plant responses to abiotic stressors in space and time. However, the interpretation and application of the PRI can be confounded because of its sensitivity to several variables changing at the diurnal (e.g., irradiation, shadow fraction) and seasonal (e.g., leaf area, chlorophyll and carotene pigment concentrations, irradiation) time scales. We explored different techniques to correct the PRI for variations in canopy structure and relative chlorophyll content (ChlR) using highly temporally resolved (frequency = five minutes) in-situ radiometric measurements of PRI and the Normalized Difference Vegetation Index (NDVI) over eight soft white spring wheat (Triticum aestivum L.)field plots under varying nitrogen and soil water conditions over two seasons. Our results suggest that the influence of seasonal variation in canopy ChlR and LAI on the diurnally measured PRI (PRIdiurnal) can be minimized using simple correction techniques, therefore improving the strength of PRI as a tool to quantify abiotic stressors such as daily changes in soil volumetric water content (SVWC), and vapor pressure deficit (VPD). PRIdiurnal responded strongly to available nitrogen, and linearly tracked seasonal changes in SVWC, VPD, and stomatal conductance (gc). Utilizing the PRI as an indicator of stress, yield predictions significantly over greenness indices such as the NDVI. This study provides insight towards the future interpretation and scaling of PRI to quantify rapid changes in photosynthesis, and as an indicator of plant stress.

  14. An empirical model for the statistics of sea surface diurnal warming

    Directory of Open Access Journals (Sweden)

    M. J. Filipiak

    2012-03-01

    Full Text Available A statistical model is derived relating the diurnal variation of sea surface temperature (SST to the net surface heat flux and surface wind speed from a numerical weather prediction (NWP model. The model is derived using fluxes and winds from the European Centre for Medium-Range Weather Forecasting (ECMWF NWP model and SSTs from the Spinning Enhanced Visible and Infrared Imager (SEVIRI. In the model, diurnal warming has a linear dependence on the net surface heat flux integrated since (approximately dawn and an inverse quadratic dependence on the maximum of the surface wind speed in the same period. The model coefficients are found by matching, for a given integrated heat flux, the frequency distributions of the maximum wind speed and the observed warming. Diurnal cooling, where it occurs, is modelled as proportional to the integrated heat flux divided by the heat capacity of the seasonal mixed layer. The model reproduces the statistics (mean, standard deviation, and 95-percentile of the diurnal variation of SST seen by SEVIRI and reproduces the geographical pattern of mean warming seen by the Advanced Microwave Scanning Radiometer (AMSR-E. We use the functional dependencies in the statistical model to test the behaviour of two physical model of diurnal warming that display contrasting systematic errors.

  15. Diurnal variation in gravity wave activity at low and middle latitudes

    Directory of Open Access Journals (Sweden)

    V. F. Andrioli

    2013-11-01

    Full Text Available We employ a modified composite day extension of the Hocking (2005 analysis method to study gravity wave (GW activity in the mesosphere and lower thermosphere using 4 meteor radars spanning latitudes from 7° S to 53.6° S. Diurnal and semidiurnal modulations were observed in GW variances over all sites. Semidiurnal modulation with downward phase propagation was observed at lower latitudes mainly near the equinoxes. Diurnal modulations occur mainly near solstice and, except for the zonal component at Cariri (7° S, do not exhibit downward phase propagation. At a higher latitude (SAAMER, 53.6° S these modulations are only observed in the meridional component where we can observe diurnal variation from March to May, and semidiurnal, during January, February, October (above 88 km and November. Some of these modulations with downward phase progression correlate well with wind shear. When the wind shear is well correlated with the maximum of the variances the diurnal tide has its largest amplitudes, i.e., near equinox. Correlations exhibiting variations with tidal phases suggest significant GW-tidal interactions that have different characters depending on the tidal components and possible mean wind shears. Modulations that do not exhibit phase variations could be indicative of diurnal variations in GW sources.

  16. Electron Dynamics in Nanostructures in Strong Laser Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kling, Matthias

    2014-09-11

    The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.

  17. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  18. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.

    1995-01-01

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  19. Strong-back safety latch

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  20. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    Artiklens formål er at diskutere oplevede kvaliteter og adfærdsaspekter af mobilitet med udgangspunkt i spørgsmålet om cykling i byer og relationen mellem design og adfærd. Artiklen tager afsæt i et studie forløb der involverede studerende fra Urban Design, Industriel Design Arkitektskolen Aarhus...... og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  1. [Effects of drying and wetting cycles induced by tides on net ecosystem exchange of CO2 over a salt marsh in the Yellow River Delta, China.

    Science.gov (United States)

    He, Wen Jun; Han, Guang Xuan; Xu, Yan Ning; Zhang, Xi Tao; Wang, An Dong; Che, Chun Guang; Sun, Bao Yu; Zhang, Xiao Shuai

    2018-01-01

    As a unique hydrological characteristic, the tidal action can strongly affect carbon balance in a salt marsh despite their short duration. Using the eddy covariance technique, we measured the net ecosystem CO 2 exchange (NEE) and its environmental factors and tidal change over a salt marsh in the Yellow River Delta. It aimed to investigate the effect of tidal process and drying and wetting cycles induced by tides on NEE. The results showed that the tidal process promoted the daytime CO 2 uptake, but it didn't clearly affect the nighttime CO 2 release. Tidal inundation was a major factor influencing daytime NEE. The diurnal change of NEE showed a distinct U-shaped curve on both drought and wet stages, but not with substantial variation in its amplitude during the drought stage. The drying and wetting cycles enhanced the absorption of daytime CO 2 . Under drought stage, the mean of the maximum photosynthetic rate (A max ), apparent quantum yield (α) and ecosystem respiration (R eco ) were higher than those in wet stage. In addition, the drying and wetting cycles suppressed the nighttime CO 2 release from the salt marsh but increased its temperature sensitivity.

  2. Diurnal and circadian expression profiles of glycerolipid biosynthetic genes in Arabidopsis.

    Science.gov (United States)

    Nakamura, Yuki; Andrés, Fernando; Kanehara, Kazue; Liu, Yu-chi; Coupland, George; Dörmann, Peter

    2014-01-01

    Glycerolipid composition in plant membranes oscillates in response to diurnal change. However, its functional significance remained unclear. A recent discovery that Arabidopsis florigen FT binds diurnally oscillating phosphatidylcholine molecules to promote flowering suggests that diurnal oscillation of glycerolipid composition is an important input in flowering time control. Taking advantage of public microarray data, we globally analyzed the expression pattern of glycerolipid biosynthetic genes in Arabidopsis under long-day, short-day, and continuous light conditions. The results revealed that 12 genes associated with glycerolipid metabolism showed significant oscillatory profiles. Interestingly, expression of most of these genes followed circadian profiles, suggesting that glycerolipid biosynthesis is partially under clock regulation. The oscillating expression profile of one representative gene, PECT1, was analyzed in detail. Expression of PECT1 showed a circadian pattern highly correlated with that of the clock-regulated gene GIGANTEA. Thus, our study suggests that a considerable number of glycerolipid biosynthetic genes are under circadian control.

  3. SST diurnal variability in the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, Jacob; Hasager, Charlotte Bay

    2012-01-01

    Five years of sea surface temperature (SST) retrievals from a geostationary platform are utilised to identify and characterise diurnal warming in the North and Baltic Seas. Observations from the Spinning Enhanced Visible Infrared Imager (SEVIRI) on board the Meteosat Second Generation satellite...... temperature anomalies. The best night-time reference field candidate is demonstrated to be an average of 3days of satellite observations from local midnight to 0300. When compared against night-time in situ measurements from various locations, mean biases are found in the order of ±0.1K and standard deviation...... (σ) between 0.4K and 0.9K. The 5year record with daytime temperature anomalies is used to derive robust statistical description of duration, spatial extent, proximity to coast and water depth of the diurnal warming events. Seasonal and inter-annual variations in the diurnal warming are also...

  4. Safe cycling!

    CERN Document Server

    Anaïs Schaeffer

    2012-01-01

    The HSE Unit will be running a cycling safety campaign at the entrances to CERN's restaurants on 14, 15 and 16 May. Pop along to see if they can persuade you to get back in the saddle!   With summer on its way, you might feel like getting your bike out of winter storage. Well, the HSE Unit has come up with some original ideas to remind you of some of the most basic safety rules. This year, the prevention campaign will be focussing on three themes: "Cyclists and their equipment", "The bicycle on the road", and "Other road users". This is an opportunity to think about the condition of your bike as well as how you ride it. From 14 to 16 May, representatives of the Swiss Office of Accident Prevention and the Touring Club Suisse will join members of the HSE Unit at the entrances to CERN's restaurants to give you advice on safe cycling (see box). They will also be organising three activity stands where you can test your knowle...

  5. Seasonal and Diurnal Variations of Tropical Tropopause Layer (TTL) Over the Indian Peninsula

    Science.gov (United States)

    Muhsin, M.; Sunilkumar, S. V.; Venkat Ratnam, M.; Krishna Murthy, B. V.; Parameswaran, K.

    2017-12-01

    Seasonal and diurnal variations in the thermal structure of the troposphere and lower stratosphere with special reference to the tropical tropopause layer (TTL) are studied using data from 3 h interval radiosonde launches carried out simultaneously from Trivandrum (8.5°N, 76.9°E) and Gadanki (13.5°N,79°E) during December 2010 to March 2014. TTL is defined as the region extending from the level of minimum stability (LMinS) to the level of maximum stability (LMaxS). Above the cold point tropopause (CPT), temperature showed warm anomaly (4-5 K) during summer monsoon (June-September) and cold anomaly (up to -4 K) during winter (December-February). The temperature in the troposphere showed a clear diurnal variation (±0.5 K) with a cold anomaly during early morning and warm anomaly during the day in all the seasons. At Gadanki, the diurnal temperature anomaly in the lower stratosphere showed its phase propagating downward with time, whereas at Trivandrum such variations are not clearly evident. At diurnal timescales, the TTL showed significant variations at LMinS (0.5-1.5 km/5-7 K) and smaller variations at CPT (0.2-0.5 km/2-3 K). In general, the amplitude of the diurnal component is greater than the semidiurnal component for all the TTL parameters, and these amplitudes are relatively larger at Trivandrum than at Gadanki. The observed diurnal variations could be the manifestation of tidal oscillations and/or due to the influence of local convection. Correlation analysis between different TTL parameters indicated a slow transition from a governing adiabatic process in the TTL base to a diabatic process at the TTL top.

  6. Repetitive methylphenidate administration modulates the diurnal behavioral activity pattern of adult female SD rats.

    Science.gov (United States)

    Lee, Min J; Yang, Pamela B; Wilcox, Victor T; Burau, Keith D; Swann, Alan C; Dafny, Nachum

    2011-02-01

    Diurnal rhythms influence many of the physiological processes that act to maintain homeostasis of the body in response to different environmental changes. Thus, disturbances in diurnal rhythms can lead to various physiological complications. Repeated exposure to psychostimulants may cause long-term effects by disturbing diurnal rhythms. The aim of the present study is to use the open field assay to determine whether repeated exposure to the psychostimulant methylphenidate (MPD) changes diurnal locomotor activity patterns of female adult Sprague-Dawley (SD) rats. As much as 31 female adult SD rats were divided into four groups. On experimental day (ED) 1, all groups were given an injection of saline. On ED 2-7, animals were injected once a day with either saline, or 0.6 mg/kg MPD, or 2.5 mg/kg MPD, or 10 mg/kg MPD depending on the group. On ED 8-10, no injections were given (washout period). On ED 11, animals were treated as they were on ED 2-7. Locomotor movements were recorded using a computerized animal activity monitoring system. The horizontal activity (HA), total distance traveled (TDT), and number of stereotypies (NOS) were analyzed by cosine curve statistical analysis (CCSA) test. The HA and TDT diurnal rhythm activity patterns of ED 2, 7, 8, and 11 were significantly different (p < 0.05) from the control recording of ED 1 according to the CCSA test. The observation obtained in this study suggests that repeated administration of MPD (all doses tested) is able to change diurnal locomotor patterns, which indicates that chronic MPD treatment exerts long-term effects.

  7. Relationship between the global electric circuit and electrified cloud parameters at diurnal, seasonal, and interannual timescales

    Science.gov (United States)

    Lavigne, Thomas; Liu, Chuntao; Deierling, Wiebke; Mach, Douglas

    2017-08-01

    In the early 1900s, J. W. Whipple began to validate C. T. R. Wilson's global electric circuit (GEC) hypothesis by correlating the diurnal variation of global thunder days with the diurnal variation of the fair weather electric field measured by the Carnegie Cruise. This study applies 16+ years of precipitation feature (PF) data from the Tropical Rainfall Measuring Mission, including lightning data from the Lightning Imaging Sensor, alongside 12 years of electric field measurements from Vostok, Antarctica, to further examine this relationship. Joint diurnal-seasonal variations of the electric field are introduced and compared with a variety of PF parameters that are potentially related to the GEC. All tested PF parameters showed significant correlations to the electric field on the joint seasonal-diurnal timescale, with the flash rate and volume of 30 dBZ between the -5°C and -35°C isotherms showing the best linear correlations with R2 values of 0.67 and 0.62, respectively. Furthermore, these relationships are analyzed during the two different phases of the El Niño-Southern Oscillation. Results show different seasonal-diurnal variations of the electric field during El Niño and La Niña periods, with enhancements in the electric field between the months of January through April at 16-24 UTC in La Niña years. A similar trend is shown in global PF parameters, indicating relationships between the variations seen in the fair weather electric field and the variations of global PFs at diurnal, seasonal, and interannual timescales. This provides further evidence that PFs around the globe have a direct connection to the GEC.

  8. Titanium: light, strong, and white

    Science.gov (United States)

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  9. On the diurnal ranges of sea surface temperature (SST) in the north Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Nasnodkar, N.; Rajesh, G.; Joseph, K.J.; Suresh, I.; Almeida, A.M.

    satellite-based microwave and infrared sen- sors, indicated that a simple model of diurnal warming as a function of local time, wind speed and solar radiation can account for most of the diurnal warming (Gentemann et al 2003; Stuart–Menteth et al 2003... in 0.2 ◦ C bins according to their magni- tudes varying from −0.5 ◦ Cto2.1 ◦ C. The ΔSSTs that exceeded 2.1 ◦ Cweregroupedinthe>2.1 ◦ C bin. The bin width of 0.2 ◦ C was chosen consider- ing the measurement accuracy of temperature sen- sors attached...

  10. Diurnal variability of Synechococcus abundance in Sagami Bay, Japan

    Digital Repository Service at National Institute of Oceanography (India)

    Mitbavkar, S.; Saino, T.

    copies but not yet divided (Fig. 2). Resultss Hydrography Temperature and salinity ranged from 15 to 23.5°C and 33 to 34.5, respectively (Fig. 3c-f). The depth at which the temperature change from the surface temperature is 0.5°C is defined..., according to the endogenous clock (Johnson et al., 1996) that is driven by the favorable external forcing such as light and nutrients during the day, thus leading to a diel variability in cell cycle progression pattern. This observation was possible due...

  11. Tomato plants overexpressing cryptochrome 2 reveal altered expression of energy and stress-related gene products in response to diurnal cues.

    Science.gov (United States)

    Lopez, Loredana; Carbone, Fabrizio; Bianco, Linda; Giuliano, Giovanni; Facella, Paolo; Perrotta, Gaetano

    2012-05-01

    In order to sense and respond to the fluctuating light conditions, higher plants possess several families of photoreceptors, such as phytochromes (PHYs), cryptochromes (CRYs) and phototropins. CRYs are responsible for photomorphogenesis and play a role in circadian, developmental and adaptive growth regulation of plants. In tomato (Solanum lycopersicum), CRY2 controls vegetative development, flowering time, fruit antioxidant content as well as the diurnal transcription of several other photoreceptor genes. We applied large-scale molecular approaches to identify altered transcripts and proteins in tomato wild-type (WT) versus a CRY2 overexpressing transgenic genotype, under a diurnal rhythm. Our results showed that tomato CRY2 profoundly affects both gene and protein expression in response to daily light cycle. Particularly altered molecular pathways are related to biotic/abiotic stress, photosynthesis, including components of the light and dark reactions and of starch and sucrose biosynthesis, as well as to secondary metabolism, such as phenylpropanoid, phenolic and flavonoid/anthocyanin biosynthesis pathways. One of the most interesting results is the coordinated up-regulation, in the transgenic genotype, of a consistent number of transcripts and proteins involved in photorespiration and photosynthesis. It is conceivable that light modulates the energetic metabolism of tomato through a fine CRY2-mediated transcriptional control. © 2011 Blackwell Publishing Ltd.

  12. Relative roles of emissions and meteorology in the diurnal pattern of urban PM10: analysis of the daylight saving time effect.

    Science.gov (United States)

    Muñoz, Ricardo C

    2012-06-01

    Daylight saving time (DST) is a common practice in many countries, in which Official Time (OT) is abruptly shifted 1 hour with respect to solar time on two occasions every year (in fall and spring). All anthropogenic emitting processes tied to OT like job and school commuting traffic, abruptly change in this moment their timing with respect to solar time, inducing a sudden shift between emissions and the meteorological factors that control the dispersion and transport of air pollutants. Analyzing 13 years of hourly particulate matter (PM10) concentrations measured in Santiago, Chile, we demonstrate that the DST practice has observable non-trivial effects in the PM10 diurnal cycle. The clearest impact is in the morning peak of PM10 during the fall DST change, which occurs later and has on average a significant smaller magnitude in the days after the DST change as compared to the days before it. This decrease in magnitude is most remarkable because it occurs in a period of the year when overall PM10 concentrations increase due to generally worsening of the dispersion conditions. Results are shown for seven monitoring stations around the city, and for the fall and spring DST changes. They show clearly the interplay of emissions and meteorology in conditioning urban air pollution problems, highlighting the role of the morning and evening transitions of the atmospheric boundary layer in shaping the diurnal pattern of urban air pollutant concentrations.

  13. Diurnal, seasonal, and annual trends in tropospheric CO in Southwest London during 2000-2015: Wind sector analysis and comparisons with urban and remote sites

    Science.gov (United States)

    Hernández-Paniagua, Iván Y.; Lowry, David; Clemitshaw, Kevin C.; Palmer, Paul I.; Fisher, Rebecca E.; France, James L.; Mendoza, Alberto; O'Doherty, Simon; Forster, Grant; Lanoisellé, M.; Nisbet, Euan G.

    2018-03-01

    Ambient carbon monoxide (CO) and meteorological parameters measured at the Egham (EGH) semi-rural site in SW London during 2000-2015 have permitted wind sector analysis of diurnal and seasonal cycles, and interpretation of long-term trends. CO daily amplitudes are used as a proxy for anthropogenic emissions. At EGH, morning and evening peaks in CO arise from the dominant contribution of road transport sources. Smaller amplitudes are observed during weekends than weekdays due to lower combustion emissions, and for mornings compared to evenings due to the timing of the development and break-up of the nocturnal inversion layer or planetary boundary layer (PBL). A wavelet transform revealed that the dominant mode of CO variability is the annual cycle, with apparent winter maxima likely due to increased CO emissions from domestic heating with summer minima ascribed to enhanced dispersion and dilution during the annual maximum of PBL mixing heights. Over the last two decades, both mitigation measures to reduce CO emissions and also a major switch to diesel cars, have accompanied a change at EGH from the dominance of local diurnal sources to a site measuring close to Atlantic background levels in summer months. CO observed in the S and SW wind sectors has declined by 4.7 and 5.9 ppb yr-1 respectively. The EGH CO record shows the highest levels in the early 2000s, with levels in E and calm winds comparable to those recorded at background stations in Greater London. However, since 2012, levels in S-SW sector have become more comparable with Mace Head background except during rush-hour periods. Marked declines in CO are observed during 2000-2008 for the NE, E, SE (London) and calm wind sectors, with the smallest declines observed for the S, SW and W (background) sectors. For the majority of wind sectors, the decline in CO is less noticeable since 2008, with an apparent stabilisation for NE, E and SE after 2009. The EGH CO data record exhibits a similar but slower exponential

  14. Diurnal and Directional Responses of Chlorophyll Fluorescence and the PRI in a Cornfield

    Science.gov (United States)

    Middleton, Elizabeth; Cheng, Y. B.; Corp, L.; Campbell, P.; Kustas, W.

    2010-01-01

    Determining the health and vigor of vegetation using high spectral resolution remote sensing is an important goal which has application to monitoring agriculture and ecosystem productivity and carbon exchange. Two spectral indices used to assess whether vegetation is performing near-optimally or exhibiting symptoms of environmental stress (e.g., drought or nutrient deficiency, non-optimal temperatures, etc.) are the Photochemical Reflectance Index (PRI) and solar-induced red and far-red Chlorophyll Fluorescence (Fs). Both the PRI and Fs capture the dynamics of photoprotection mechanisms within green foliage: the PRI is based on the association of the reflected radiation in the green spectrum with the xanthophyll cycle, whereas Fs measures the emitted radiation in the red and far-red spectrum. Fs was determined from retrievals in the atmospheric oxygen absorption features centered at 688 and 760 nm using a modified Fraunhofer Line Depth (FLD) method. We previously demonstrated diurnal and seasonal PRI differences for sunlit vs. shaded foliage in a conifer forest canopy, as expressed in the hotspot and darkspot of the Bidirectional Reflectance Function (BRF). In a USDA-ARS experimental field site located in Beltsville, MD, USA, measurements were acquired over a corn crop from a nadir view in 2008 with an ASD FieldSpec Pro (Analytical Spectral Devices, Inc., Boulder, CO, USA) to study the behavior of the PRI for sunlit and shaded foliage as captured in reflectance variations associated with the BRF, in a I m tall canopy in the vegetative growth stage. Those observations were compared to simulations obtained from two radiative transfer models. Measurements were then acquired to examine whether the PRI and Fs were influenced by view zenith and azimuth geometries at different times of day. Those measurements were made in 2010 with the Ocean Optics USB4000 Miniature Fiber Optic Spectrometer (Ocean Optics Inc., Dunedin, Florida, USA) at several times during the day on

  15. Diurnal inhibition of NMDA-EPSCs at rat hippocampal mossy fibre synapses through orexin-2 receptors

    Science.gov (United States)

    Perin, Martina; Longordo, Fabio; Massonnet, Christine; Welker, Egbert; Lüthi, Anita

    2014-01-01

    Diurnal release of the orexin neuropeptides orexin-A (Ox-A, hypocretin-1) and orexin-B (Ox-B, hypocretin-2) stabilises arousal, regulates energy homeostasis and contributes to cognition and learning. However, whether cellular correlates of brain plasticity are regulated through orexins, and whether they do so in a time-of-day-dependent manner, has never been assessed. Immunohistochemically we found sparse but widespread innervation of hippocampal subfields through Ox-A- and Ox-B-containing fibres in young adult rats. The actions of Ox-A were studied on NMDA receptor (NMDAR)-mediated excitatory synaptic transmission in acute hippocampal slices prepared around the trough (Zeitgeber time (ZT) 4–8, corresponding to 4–8 h into the resting phase) and peak (ZT 23) of intracerebroventricular orexin levels. At ZT 4–8, exogenous Ox-A (100 nm in bath) inhibited NMDA receptor-mediated excitatory postsynaptic currents (NMDA-EPSCs) at mossy fibre (MF)–CA3 (to 55.6 ± 6.8% of control, P = 0.0003) and at Schaffer collateral–CA1 synapses (70.8 ± 6.3%, P = 0.013), whereas it remained ineffective at non-MF excitatory synapses in CA3. Ox-A actions were mediated postsynaptically and blocked by the orexin-2 receptor (OX2R) antagonist JNJ10397049 (1 μm), but not by orexin-1 receptor inhibition (SB334867, 1 μm) or by adrenergic and cholinergic antagonists. At ZT 23, inhibitory effects of exogenous Ox-A were absent (97.6 ± 2.9%, P = 0.42), but reinstated (87.2 ± 3.3%, P = 0.002) when endogenous orexin signalling was attenuated for 5 h through i.p. injections of almorexant (100 mg kg−1), a dual orexin receptor antagonist. In conclusion, endogenous orexins modulate hippocampal NMDAR function in a time-of-day-dependent manner, suggesting that they may influence cellular plasticity and consequent variations in memory performance across the sleep–wake cycle. PMID:25085886

  16. Influence of diurnal photosynthetic activity on the morphology, structure, and thermal properties of normal and waxy barley starch

    DEFF Research Database (Denmark)

    Goldstein, Avi; Annor, George; Vamadevan, Varatharajan

    2017-01-01

    This study investigated the influence of diurnal photosynthetic activity on the morphology, molecular composition, crystallinity, and gelatinization properties of normal barley starch (NBS) and waxy barley starch (WBS) granules from plants cultivated in a greenhouse under normal diurnal (16h light...

  17. A quantitative analysis of the diurnal evolution of Ionospheric Alfvén resonator magnetic resonance features and calculation of changing IAR parameters

    Directory of Open Access Journals (Sweden)

    S. R. Hebden

    2005-07-01

    Full Text Available Resonance features of the Ionospheric Alfvén Resonator (IAR can be observed in pulsation magnetometer data from Sodankylä, Finland using dynamic spectra visualizations. IAR resonance features were identified on 13 of 30 days in October 1998, with resonance structures lasting for 3 or more hours over 10 intervals. The diurnal evolution of the harmonic features was quantified for these 10 intervals using a manual cursor-clicking technique. The resonance features displayed strong linear relationships between harmonic frequency and harmonic number for all of the time intervals studied, enabling a homogeneous cavity model for the IAR to be adopted to interpret the data. This enabled the diurnal variation of the effective size of the IAR to be obtained for each of the 10 time intervals. The average effective size was found to be 530 km, and to have an average variation of 32% over each time interval: small compared to the average variation in Alfvén velocity of 61%. Thus the diurnal variation of the harmonics is chiefly caused by the changing plasma density within the IAR due to changing insolation. This study confirms Odzimek (2004 that the dominating factor affecting the IAR eigenfrequencies is the variation in the Alfvén velocity at the F-layer ion-density peak, with the changing IAR size affecting the IAR eigenfrequencies to a smaller extent. Another IAR parameter was derived from the analysis of the IAR resonance features associated with the phase matching structure of the standing waves in the IAR. This parameter varied over the time intervals studied by 20% on average, possibly due to changing ionospheric conductivity. Keywords. Ionosphere (Auroral ionosphere;Wave propagation – Radio science (Electromagnetic noise and interference

  18. Coral-algae metabolism and diurnal changes in the CO2-carbonate system of bulk sea water

    Directory of Open Access Journals (Sweden)

    Paul L. Jokiel

    2014-05-01

    Full Text Available Precise measurements were conducted in continuous flow seawater mesocosms located in full sunlight that compared metabolic response of coral, coral-macroalgae and macroalgae systems over a diurnal cycle. Irradiance controlled net photosynthesis (Pnet, which in turn drove net calcification (Gnet, and altered pH. Pnet exerted the dominant control on [CO32−] and aragonite saturation state (Ωarag over the diel cycle. Dark calcification rate decreased after sunset, reaching zero near midnight followed by an increasing rate that peaked at 03:00 h. Changes in Ωarag and pH lagged behind Gnet throughout the daily cycle by two or more hours. The flux rate Pnet was the primary driver of calcification. Daytime coral metabolism rapidly removes dissolved inorganic carbon (DIC from the bulk seawater and photosynthesis provides the energy that drives Gnet while increasing the bulk water pH. These relationships result in a correlation between Gnet and Ωarag, with Ωarag as the dependent variable. High rates of H+ efflux continued for several hours following mid-day peak Gnet suggesting that corals have difficulty in shedding waste protons as described by the Proton Flux Hypothesis. DIC flux (uptake followed Pnet and Gnet and dropped off rapidly following peak Pnet and peak Gnet indicating that corals can cope more effectively with the problem of limited DIC supply compared to the problem of eliminating H+. Over a 24 h period the plot of total alkalinity (AT versus DIC as well as the plot of Gnet versus Ωarag revealed a circular hysteresis pattern over the diel cycle in the coral and coral-algae mesocosms, but not the macroalgae mesocosm. Presence of macroalgae did not change Gnet of the corals, but altered the relationship between Ωarag and Gnet. Predictive models of how future global changes will effect coral growth that are based on oceanic Ωarag must include the influence of future localized Pnet on Gnet and changes in rate of reef carbonate

  19. Evidence for island effects and diurnal signals in satellite images of clouds over the tropical western pacific

    Energy Technology Data Exchange (ETDEWEB)

    Barr-Kumarakulasinghe, S.A. [State Univ. of New York, Stony Brook, NY (United States); Reynolds, R.M.; Minnett, P.J. [Brookhaven National Lab., Upton, NY (United States)

    1996-04-01

    Instruments to measure atmospheric radiation and ancillary meteorological variables will be set up on Manus Island as the first site of the tropical western pacific (TWP) locale of the Atmospheric Radiation Measurements (ARM) program. Manus is in the {open_quotes}warm pool{close_quotes} region of the TWP. This region is critical in establishing global atmospheric circulation patterns and is a primary energy source for the Hadley and Walker cells. The myriad islands and enclosed seas in the immediate vicinity of Manus have been referred to as the {open_quotes}maritime continent{close_quotes}, which has the deepest convective activity in the world. Manus is in a region having a global impact on climate and where island effects on clouds are likely to be important. In this preliminary analysis we have sought evidence of island effects in the cloud fields around Manus and have studied the variability of the diurnal cycles of cloud cover over Manus and over other islands and areas of open sea in the region.

  20. Diurnal changes in chlorophyll fluorescence and light utilization in Colocasia esculenta leaves grown in marshy waterlogged area

    International Nuclear Information System (INIS)

    Roy Chowdhury, S.; Ashwani Kumar; Sahoo, N.

    2009-01-01

    Diurnal cycle of chlorophyll fluorescence was evaluated in Colocasia esculenta grown in marshy land under sun or under shade. The sun leaves maintained higher electron transport rate (ETR) and steady state to initial fluorescence ratio (Fs/F0) than shade leaves. In spite of lower ETR, higher photochemical quenching (PQ) and effective quantum yield of photosystem 2 (PS 2) was evident in shade plants compared to plants exposed to higher irradiance. ETR increased linearly with increase in irradiance more under low irradiance (r2 = 0.84) compared to higher irradiance (r2 = 0.62). The maximum quantum yield of PS 2 (Fv/Fm) did not differ much in sun and shade leaves with the exception of midday when excess of light energy absorbed by plants under sun was thermally dissipated. Hence swamp taro plants adopted different strategies to utilize radiation under different irradiances. At higher irradiance, there was faster decline in proportion of open PS 2 centers (PQ) and excess light energy was dissipated through non-photochemical quenching. Under shade, absorbed energy was effectively utilized resulting in higher PS2