temporal variation

The cell-free layer exhibits dynamic characteristics in the time domain that may be capable of altering nitric oxide (NO) bioavailability in small arterioles. However, this effect has not been fully elucidated. This study utilized a computational model on NO transport to predict how temporal variations in the layer width could modulate NO bioavailability in the arterioles. Data on the layer width was acquired from high-speed video recordings in arterioles (ID = 48.4 ± 1.8 lm) of the rat cremaster muscle. We found that when wall shear stress response was not considered, the layer variability could lead to a slight decrease (1.6-6.6%) in NO bioavailability that was independent of transient changes in NO scavenging rate. Conversely, the transient response in wall shear stress and NO production rate played a dominant role in reversing this decline such that a significant augmentation (5.3-21.0%) in NO bioavailability was found with increasing layer variability from 24.6 to 63.8%. This study highlighted the importance of the temporal changes in wall shear stress and NO production rate caused by the layer width variations in prediction of NO bioavailability in arterioles.

Two net balance records of neighboring glaciers under different conditions are analyzed to extract temporal variations in glacier melting in the Himalayas. Significant melt was observed every year at one site (wet site), whereas no melt occurred at the second site because of its high elevation (dry site). Accumulation at the wet site of a glacier is estimated from the dry site neighboring another glacier through a measured precipitation record for a short time period. The difference between the estimated accumulation and the net balances at the wet site is obtained as the ''melt index,'' which represents the glacier melting conditions. The melt index with an interannual timescale is significant as a climatic proxy at high elevation since no relationship between stable isotopes and temperature is established and few long-term temperature records are available at high elevations in the Himalayas. The melt index showed a decadal fluctuation with a major amplitude never reported in previous studies with respect to temperature and ice cores analyses in the Himalayas. Ice cores from a site where significant melt occurs every year have not been considered available in reconstructing past climates since climatic signals in ice were disturbed by meltwater infiltration. However, we suggest a new approach to glean temperature information by a combination of wet and dry cores, not obtainable from a good-quality ice core alone.

The Hengill volcanic system in SW-Iceland is a central volcano that produces basaltic and subordinate amount of more evolved rock types and is cut by an active NE-SW fissure swarm. Recent seismic activity indicates that the South Iceland Seismic Zone (SISZ) intersects the eastern part of the fissure zone forming a triple junction with the volcanic zone. The main geological features include a fissure zone and a graben into which most of the volcanic products (lavas and hyaloclastites) accumulate forming highlands in its central part. Three basaltic fissure eruptions of 9, 5 and 2 thousand years before present are found within the fissure swarm. Reykjavik Energy has explored and exploited the huge geothermal resource developed in this volcanic system, first in Nesjavellir in the northern sector and then Hellisheiði in the south. Extensive geophysical surveys including resistivity (TEM) and MT have been done to delineate the geothermal anomaly. A total of about 90 deep exploration, pro...

Petroleum products, such as gasoline, leaked from an underground storage tank can be recovered successfully by two-pump operations. The success of the recovery effort depends on the accurate placement of the recovery well at the spill site. An effective recovery operation can minimize the remaining contamination mass in the subsurface. Therefore, a careful evaluation and determination has to be made as to where to locate the recovery well. The location of the well can be decided based on an estimation of the extent and thickness of free product on the water table. Such an estimation should be based on analysis of governing mechanisms. In this study we present analytical solutions to estimate the recovery of oil from an established oil lens. These solutions are obtained by applying the Laplace transformation to averaged linear partial differential equations governing the phenomenon. The governing equation for the free product thickness is derived by averaging the oil phase mass balance equation along the free product thickness and substituting the boundary conditions at the oil/ water interface and oil surface. The analytical solutions estimate the temporal and spatial distribution of free product thickness on the water table for a number of recovery scenarios. Results are presented for the temporal and spatial variation of the free product thickness, temporal variation of the free product volume recovered, and recovery efficiency based on the readings at the monitoring wells. Since they can be utilized without a great deal of data, analytical solutions are quite attractive as screening tools in two-pump free product recovery operations.

The scope of phenetic variation exhibited by populations of lake whitefish Coregonus clupeaformis in the Canadian Maritime Provinces is not known, which complicates the task of accurately identifying specimens of the endangered Atlantic whitefish C. huntsmani. We developed criteria for accurate (!95% correct classification) species discrimination using morphological data acquired from archival and recent coregonid collections from the Maritime Provinces. We used discriminant function analyses to assess (1) the usefulness of Atlantic whitefish external typological characters in accurately identifying species, (2) the temporal stability of reportedly diagnostic characters, and (3) which morphological characters could be used to accurately identify these coregonids to species. Not all external typological characters were robust in the discrimination of recent Atlantic whitefish and lake whitefish collections. Several previously identified diagnostic characters exhibited significant temporal variation but remained robust in species discrimination. Species-specific differences for the number of lateral line scales, mouth position, and proportional pectoral fin length could be used concomitantly for accurate (!95% correct classification) identification of coregonid species in the Canadian Maritime Provinces. Atlantic whitefish possessed a significantly (P , 0.001) greater number of lateral line scales (range ¼ 90-102; mean 6 SD ¼ 93.79 6 2.70) than lake whitefish (range ¼ 66-91; mean ¼ 77.18 6 4.21), a significantly (P , 0.01) shorter pectoral fin than lake whitefish (11% and 16% of fork length, respectively), and a significantly (P , 0.001) more terminal mouth than lake whitefish (ratio of upper jaw to lower jaw: mean 6 SD ¼ 0.98 6 0.07 and 0.82 6 0.06, respectively). These characters can also be used to distinguish between Atlantic whitefish and round whitefish Prosopium cylindraceum collected in the Maritime Provinces.

Dynamic systems with lumped parameters which experience random temporal variations are considered in this paper. These variations may lead to ''short-term'' dynamic instability that is reflected in the system's response as alternating periods of zero or almost zero response and rare short outbreaks. As long as it may be impractical to preclude completely such outbreaks for a designed system, the corresponding response should be analyzed to evaluate the system's reliability. Results of such analyses are presented separately for cases of slow and rapid parameter variations. Linear models of the systems are studied in the former case using parabolic approximation (PA) for the variations in the vicinity of their peaks together with Krylov-Bogoliubov (KB) averaging for the transient response. This results in a solution for the response probability density function (PDF). The case of rapid broadband parameter variations is studied using theory of Markov processes. The system is assumed to operate beyond its stochastic instability threshold -although only slightly -and its nonlinear model is used accordingly. The analysis is based on solution of the Fokker-Planck-Kolmogorov (FPK) partial differential equation for stationary PDF of the response. Several such PDFs are analyzed; they are found to have integrable singularities at the origin indicating an intermittent nature of the response.

Coccolithophores, a special group of calcifying phytoplankton in the Indian Ocean, their distribution and productivity are strongly mediated by monsoonal dynamics, and they are a key player in the oceanic biogeochemical cycles. Our study explores the multifaceted dynamics between monsoondriven environmental variability and coccolithophores, examining the influences of upwelling, nutrient accessibility and stratification. Normally, the Southwest (SW) monsoon is characterized by strong winds and substantial upwelling of nutrients and promotes coccolithophore blooms. In contrast, the population density is often lower with reduced upwelling of the northeast (NE) monsoon. This driving force is also noted in the analysis as different responses across regions of the Indian Ocean highlight the local environmental conditions. In addition, it highlights the importance of detailed long-term monitoring and innovative methods, including remote sensing and in situ measurements. As the monsoon pattern continues to change as a result of climate change, the research on coccolithophores in the Indian Ocean is becoming increasingly important in projecting future changes in marine ecosystems and environmental carbon. This review offers a comprehensive overview of the present state of knowledge, highlights major research gaps and proposes directions for future research to gain an understanding of the resilience and adaptability of coccolithophores in a changing environment.

Background: Microvolt T-wave alternans (TWA) have been accepted as a tool for assessing vulnerability to ventricular tachyarrhythmias. There is lack of data concerning prospective temporal variations in TWA measurements after acute myocardial infarction (AMI). We analysed the temporal patterns of TWA in post-AMI patients. Methods and Results: TWA tests were performed <1 month (TWA early) and 6 months (TWA late) after AMI in 51 consecutive patients treated with successful percutaneous coronary intervention (PCI). Twenty seven patients (53%) had anterior wall infarctions and 24 (47%) had inferior/lateral wall infarctions. TWA was measured during a treadmill manual exercise protocol and defined as positive, negative and indeterminate. Group A included patients with TWA negative in both tests and Group B included those with TWA abnormal (positive or indeterminate) at first or second determinations. TWA early was negative, positive and indeterminate in 38 (74.6%), 8 (15.6%) and 5 (9.8%) patients, respectively, whereas TWA late was negative, positive and indeterminate in 30 (58.9%), 14 (27.4%) and 7 (13.7%) patients, respectively. TWA early was classified as normal in 74.6% and abnormal in 25.4% of the cases, and TWA late was normal in 58.9% and abnormal in 41.1%. TWA tests were concordant in 36 patients (70.6%) and discordant 15 patients (29.4%). At TWA late, 10 patients (19.6%) changed from TWA negative to TWA abnormal and 4 patients (7.8%) from TWA abnormal to TWA negative. After TWA early+TWA late, 45% of the patients had 1 test classified as abnormal. Left ventricular ejection fraction was <50% in 22% of Group A and 52% of Group B (P = 0.037). Conclusions: In the era of primary PCI, temporal changes in TWA measurements may occur frequently during the first 6 months post-AMI. These findings should be considered in risk stratification strategies following AMI.

The white shrimp Penaeus (Litopenaeus) schmitti . A new species of Penaeus from the American. Atlantic. Anais Acad. Brasil. Cienc. Rio de Janeiro 8, 315-318.] has been part of commercial fisheries in Cuba since 1953. Over exploitation led to a serious decline of the captures in the early 1980s until the fishery was finally closed due to a population crash and captures were reduced to the extraction of only some breeders for the Cuban hatcheries. Previous population genetic studies in this species had shown that wild populations are genetically diverse over geographic distances as small as a few hundred kilometres providing useful information for managers. The present study provides new evidences on the spatial (and also temporal) variation of the genetic diversity and population structure in P. schmitti Cuban wild populations using both allozymes and microsatellites. It is highly probable that low effective population size of P. schmitti in Cuba results in genetic changes through time as a result of genetic drift. Two likelihood-based methods used in this work to estimated effective population size N e revealed concordant low effective numbers taking into account the species characteristics.

Osteoarthritis (OA) is the most prevalent form of arthritis and is among the most prevalent chronic conditions in the United States. Because there is no known cure for OA, treatment is directed towards the alleviation of pain, improving function, and limiting disability. The major burden of care falls on the individual, who tailors personal systems of care to alleviate troublesome symptoms. To date, little has been known about the temporal variations in self-care that older patients with OA develop, nor has it been known to what extent self-care patterns vary with ethnicity and disease severity. This study was designed to demonstrate the self-care strategies used by older African Americans and whites to alleviate the symptoms of OA on a typical day and during specific segments of a typical day over the past 30 days. A sample of 551 older adults participated in in-depth interviews, and the authors clustered their responses into six categories. Findings showed that the frequency of particular behaviors varied by time of day, disease severity, and race. Overall, patterns of self-care behaviors were similar between African-Americans and whites, but African-Americans used them in different proportions than whites and in response to disease severity. Knowledge of what strategies persons with OA use to lessen their symptoms at various times of the day may enable practitioners and their patients to improve management of OA symptoms. Recognition that people may choose their strategies to ameliorate their symptoms by race and disease severity may further enable tailored symptom relief. African-Americans; osteoarthritis; self-care; chronic disease Osteoarthritis (OA) is the most prevalent form of arthritis and is among the most prevalent chronic conditions in the U.S. . Because there is no known cure for OA, treatment is directed primarily to alleviating pain, improving function, and limiting disability . Therefore, the major burden of care falls on the individual, who tailors his or her own personal systems of care to alleviate troublesome symptoms and promote independent functioning.

New observations of the vertically integrated CO 2 mixing ratio, CO 2 , from groundbased remote sensing show that variations in CO 2 are primarily determined by largescale flux patterns. They therefore provide fundamentally different information than observations made within the boundary layer, which reflect the combined influence of large scale and local fluxes. Observations of both CO 2 and CO 2 concentrations in the free troposphere show that large-scale spatial gradients induce synoptic-scale temporal variations in CO 2 in the Northern Hemisphere midlatitudes through horizontal advection. Rather than obscure the signature of surface fluxes on atmospheric CO 2 , these synoptic-scale variations provide useful information that can be used to reveal the meridional flux distribution. We estimate the meridional gradient in CO 2 from covariations in CO 2 and potential temperature, θ, a dynamical tracer, on synoptic timescales to evaluate surface flux estimates commonly used in carbon cycle models. We find that Carnegie Ames Stanford Approach (CASA) biospheric fluxes underestimate both the CO 2 seasonal cycle amplitude throughout the Northern Hemisphere midlatitudes as well as the meridional gradient during the growing season. Simulations using CASA net ecosystem exchange (NEE) with increased and phase-shifted boreal fluxes better reflect the observations. Our simulations suggest that boreal growing season NEE (between 45-65 • N) is underestimated by ∼40 % in CASA. We describe the implications for this large seasonal exchange on inference of the net Northern Hemisphere terrestrial carbon sink.

The reflectance spectroscopy and BVRI photometry are two widely used procedures in many different fields of astronomy. Thanks to these observation techniques we categorize objects into groups according to similarities in surface properties and characteristics, improve our knowledge about the density of specific materials onorbit, identify specific spectral features, related to certain materials in comparison to laboratory samples and find evidence of material "reddening" caused by the spaceweathering or aging effects. The photometric measurements, acquired by the AGO70 telescope, are capable of recognition and processing of the diffuse part of the reflection, while the reflectance spectroscopy with the AMOS-Spec cameras capture specular reflections. Both methods are based on the capturing and processing of the incoming sunlight reflected by the object's surface, which enables us to reconnect these methods again and use them for the crosscalibration. In this article we will present the instruments and methods of the data processing, as well as the example results.

The study was conducted to investigate the surface water quality of the Tista River at Kaunia point in wet (September to November) and dry season (December to February) during the period from September 2013 to February 2014. The water samples were collected from five different sampling stations of Tista River mentioned as Station 1 (St-1), 2 (St-2), 3 (St-3), 4 (St-4) and 5 (St-5). The analysis of the study showed that the average transparency was 13.28 and 32.31 cm in wet and dry season, respectively, while the temperature was observed 25.86 and 18.18 ⁰ C in wet and dry season, respectively. The observed electrical conductivity (EC) was 84 and 145.67 µs cm-1 , pH was 7.72 and 8.03, dissolve oxygen (DO) was 5.35 and 5.37 mg l-1 , biochemical oxygen demand (BOD) 1.64 and 1.89 mg l-1 in wet and dry season, respectively. In wet season, the total dissolved solid (TDS) was measured 53.2 mg l-1 , while 73.86 mg l-1 in dry season. The alkalinity was found 40.94 and 43.4 mg l-1 in wet and dry season, whereas, the hardness was found 98.47 and 102.46 mg l-1 in the following seasons. The study showed that most of the water quality parameters of the Tista River were suitable for aquatic organisms as well as fishes. However, the agricultural runoff and waste materials generated from anthropogenic sources could be the main causes of degradation of water quality and aquatic organisms.

A dataset containing more than six years (February 2009 to present) of radiance-spectra for carbon dioxide (CO2) and methane (CH4) observations has been acquired by the Greenhouse gases Observing SATellite (GOSAT), nicknamed "Ibuki", Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS). This manuscript provides updates on the performance of the satellite and TANSO-FTS sensor and describes important changes to the data product, which has recently been made available to users. With these changes the typical accuracy of retrieved column-averaged dry air mole fractions of CO2 and CH4 ( 2 CO X and 4 CH X ) are 2ppm or 0.5% and 13ppb or 0.7%, respectively. Three major anomalies of the satellite system affecting TANSO-FTS are reported: a failure of one of the two solar paddles in May 2014, a switch to the secondary pointing system in January 2015 and most recently, a cryo-cooler shutdown and restart in August 2015. The Level 1A (L1A) (raw

For the time lapse study in CCS and EOR, we have proposed the method using the seismic ACROSS (Accurately Controlled and Routinely Operated Signal System) and geophone array. However, it is considered that the near-surface effects and their temporal changes caused by water content changes, temperature and surface wave generation, might have very large effects for time lapse estimation, and we would like to evaluate and reduce the near-surface effects by the comparison of surface and borehole geophone records. We have carried out simulation studies to evaluate the effects of near-surface and heterogeneities such as the man-made cavities in the green tuff layers (Vp ̃2.5 km/s). We also evaluate the near-surface effects by changing geophone depths. The results of the simulations are as follows. At the simulation of surface hypocenters, seismic waves passed through the man-made cavities attenuated and seismic waves scattered at the man-made cavities. This shows that there will be a hete...

Laser ranging measurements to the LAGEOS satellite from 1976 through 1989 are related via geodetic and orbital theories to a variety of geodetic and geodynamic parameters. The SL7.1 analyses are explained of this data set including the estimation process for geodetic parameters such as Earth&#x27;s gravitational constant (GM), those describing the Earth&#x27;s elasticity properties (Love numbers), and the temporally varying geodetic parameters such as Earth&#x27;s orientation (polar motion and Delta UT1) and tracking site horizontal tectonic motions. Descriptions of the reference systems, tectonic models, and adopted geodetic constants are provided; these are the framework within which the SL7.1 solution takes place. Estimates of temporal variations in non-conservative force parameters are included in these SL7.1 analyses as well as parameters describing the orbital states at monthly epochs. This information is useful in further refining models used to describe close-Earth satellite...

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Purpose The concentrations of PM 10 mass, PM 2.5 mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter. Methods Daily PM 10 and PM 2.5 samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 μg. Pre-and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters. The 18-month mean PM 10 and PM 2.5 mass concentrations ranged from 15.4 μg/m 3 in Helsinki to 56.7 μg/m 3 in Athens and from 9.0 μg/m 3 in Helsinki to 25.0 μg/m 3 in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm 3 in Helsinki to 24,180 part/cm 3 in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM 10 with the exception of Athens where PM 2.5 comprised 43% of PM 10 . Higher PM mass and number Responsible editor: Euripides Stephanou

Aerosol number size distributions have been measured since 5 May 1997 in Helsinki, Finland. The presented aerosol data represents size distributions within the particle diameter size range 8-400 nm during the period from May 1997 to March 2003. The daily, monthly and annual patterns of the aerosol particle number concentrations were investigated. The temporal variation of the particle number concentration showed close correlations with traffic activities. The highest total number concentrations were observed during workdays; especially on Fridays, and the lowest concentrations occurred during weekends; especially Sundays. Seasonally, the highest total number concentrations were observed during winter and spring and lower concentrations were observed during June and July. More than 80% of the number size distributions had three modes: nucleation mode (D p <30 nm), Aitken mode (20-100 nm) and accumulation mode (D p >90 nm). Less than 20% of the number size distributions had either two modes or consisted of more than three modes. Two different measurement sites were used; in the first (Siltavuori, 5.5.1997(Siltavuori, 5.5. -5.3.2001)), the arithmetic means of the particle number concentrations were 7000 cm -3 , 6500 cm -3 , and 1000 cm -3 respectively for nucleation, Aitken, and accumulation modes. In the second site (Kumpula, 6.3.2001(Kumpula, 6.3. -28.2.2003) ) they were 5500 cm -3 , 4000 cm -3 , and 1000 cm -3 . The total number concentration in nucleation and Aitken modes were usually significantly higher during workdays than during weekends. The temporal variations in the accumulation mode were less pronounced. The lower concentrations at Kumpula were mainly due to building construction and also the slight overall decreasing trend during these years. During the site changing a period of simultaneous measurements over two weeks were performed showing nice correlation at both sites.

Hypoxia has occurred in Upper Charlotte Harbor, a shallow (w3 m) estuary in Southwest Florida, during moderate to high freshwater flows from the Peace and Myakka Rivers and after hurricanes, due to nutrient loading and vertical stratification. This paper studies the annual hypoxia and water quality dynamics in Upper Charlotte Harbor in 2000, using CH3D-IMS, an integrated modeling system which includes coupled models of circulation, wave, sediment transport, and water quality. The CH3D-IMS simulations showed that bottom-water hypoxic conditions occur during periods with relatively steady moderate to high (5e40 m 3 /s) freshwater inflows and sediment oxygen demand (SOD). During periods of relatively steady moderate to high river discharge, strong vertical salinity stratification results in reduced vertical mixing which prevents surface water from supplying dissolved oxygen (DO) to bottom water where SOD continuously consumes DO. There was significant temporal fluctuation of the hypoxic water volume, as a result of significant temporal variation in vertical turbulent mixing associated with combinations of spring-neap tides and river discharge. The validated modeling system could be used to forecast hypoxia.

Structural features of volcanic and hydrothermal systems can be used to infer the location of magma chambers or productive geothermal areas. The Hengill volcanic triple-junction complex has a well-developed geothermal system, which is being exploited to extract hot fluids that are used for electrical power and heat production. In the framework of the I-GET project, a 4month temporary seismological network including seven highdynamic broadband instruments was deployed and 1D transient electromagnetic soundings (TEM) and 3D magnetotelluric (MT) surveys were performed to improve understanding of the relationships between structural features, seismic activity and fluid production at the Hengill geothermal system. The MT and TEM data set is analyzed elsewhere. The analysis of the seismological data set allowed the detection and classification of more than 600 earthquakes, among which long-period (LP) earthquakes were observed for the first time in this area. This work focuses first on a joint inversion for the 3D velocity structure and determination of the locations of the hypocentres from about 250 local volcano-tectonic earthquakes with clear Pand S-wave arrival times. The results confirm those from earlier tomography studies in this area. Integrating the seismic velocity and resistivity models in a semi-quantitative approach by crossplotting the resistivity model with the velocity ratio V P /V S delineates a structural body with a high seismic velocity ratio and low resistivity that is interpreted as the main heat source of the geothermal system.

Mengaku membenarkan Laporan Akhir Penyelidikan ini disimpan di Perpustakaan Universiti Teknologi Malaysia dengan syarat-syarat kegunaan seperti berikut: 1. Laporan Akhir Penyelidikan ini adalah hakmilik Universiti Teknologi Malaysia. 2. Perpustakaan Universiti Teknologi Malaysia dibenarkan membuat salinan untuk tujuan rujukan sahaja. 3. Perpustakaan dibenarkan membuat penjualan salinan Laporan Akhir Penyelidikan ini bagi kategori TIDAK TERHAD.

Understanding the extent to which natural assemblages withstand changes in the regime of disturbance has considerable practical and theoretical interest. In this paper we examine the separate and interactive effects of intensity, temporal variation, and spatial extent of disturbance on temporal variance in assemblages of algae and invertebrates of rocky shores in the northwest Mediterranean. Temporal variation of disturbance is a predictor variable in the experiment, while temporal variance in abundance and number of taxa and in structure of assemblages are response variables. Multivariate analyses detected a positive relationship between intensity of disturbance and temporal variance in the structure of assemblages, while temporal variation of disturbance elicited the opposite effect. Univariate analyses conducted on the most abundant taxa revealed idiosyncratic patterns, while temporal variance in mean number of taxa was greatly reduced by disturbance, with no distinction among levels of intensity, temporal variation, or spatial extent. These outcomes suggest caution in interpreting the results of experiments in which intensity and temporal variation of disturbance cannot be separated. Distinguishing between these traits of disturbance may be key to predicting the ecological consequence of environmental fluctuations, including those expected under modified climate scenarios.

measurements then~s.elves. Within the error,s of the methods used, estimation of standard nwteorologieal shelter height air temperatures recorded at the time of satellite overpass appears possible. Further r@nenwnts of the remote sensing methods used here are possible and can be expected in the era of the National Aeronautics and Space Administration's' Earth Observing System.

We have studied collisional perturbations of radio-frequency (rf) electric-dipole (E1) transitions between the nearly degenerate opposite-parity levels in atomic dysprosium (Dy) in the presence of 10 to 80 µTorr of H2, N2, He, Ar, Ne, Kr, and Xe. Collisional broadening and shift of the resonance, as well as the attenuation of the signal amplitude are observed to be proportional to the foreign-gas density with the exception of H2 and Ne, for which no shifts were observed. Corresponding rates and cross sections are presented. In addition, rates and cross sections for O2 are extracted from measurements using air as foreign gas. The primary motivation for this study is the need for accurate determination of the shift rates, which are needed in a laboratory search for the temporal variation of the fine-structure constant [A. T.

We monitored bacterioplankton communities from Chesapeake Bay over 2 years (2002)(2003)(2004)) by use of denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene. Chesapeake Bay bacterioplankton exhibited a repeatable annual pattern and strong seasonal shifts. In winter, the bacterial communities were dominated by Alphaproteobacteria and Actinobacteria, whereas in summer, the predominant bacteria were members of Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, Actinobacteria, Planctomycetes, and Bacteroidetes. Phylotypes of Alphaproteobacteria and Actinobacteria present in warm seasons were different from those in cold seasons. Relatively stable communities were present in summer-fall across the sampling years, whereas winter communities were highly variable interannually. Temporal variations in bacterial communities were best explained by changes of chlorophyll a (Chl a) and water temperature, but dissolved oxygen, ammonia, nitrite and nitrate, and viral abundance also contributed significantly to the bacterial seasonal variations. * Numbers in parentheses stand for corresponding month and year (same in Figures). { Middle bay. { Southern bay.

Major, trace element and isotopic (Sr, Nd, Pb) data are reported for representative samples of interplinian (Protohistoric, Ancient Historic and Medieval Formations) activity of Mt. Somma-Vesuvius volcano during the last 3500 years. Tephra and lavas exhibit signi®cant major, trace element and isotopic variations. Integration of these data with those obtained by previous studies on the older Somma suites and on the latest activity, allows to better trace a complete petrological and geochemical evolution of the Mt. Somma-Vesuvius magmatism. Three main groups of rocks are recognized. A ®rst group is older than 12.000 yrs, and includes effusive-explosive activity of Mt. Somma. The second group (8000±2700 yrs B.P.) includes the products emitted by the Ottaviano (8000 yrs. B.P.) and Avellino (3550 yrs B.P.) plinian eruptions and the interplinian activity associated with the Protohistoric Formation. Ancient Historic Formation (79±472 A.D.), Medieval Formation (472±1139 A.D.) and Recent interplinian activity (1631±1944 A.D.) belong to the third group of activity (79±1944 A.D.). The three groups of rocks display distinct positive trends of alkalis vs. silica, which become increasingly steeper with age. In the ®rst group there is an increase in silica and alkalis with time, whereas an opposite tendency is observed in the two younger groups. Systematic variations are also evident among the incompatible (Pb, Zr, Hf, Ta, Th, U, Nb, Rb, Cs, Ba) and compatible elements (Sr, Co, Cr). REE document variable degrees of fractionation, with recent activity displaying higher La/Yb ratios than Medieval and Ancient Historic products with the same degree of evolution. N-MORB normalized multi-element diagrams for interplinian rocks show enrichment in Rb, Th, Nb, Zr and Sm (b à 10 N-MORB). Sr isotope ratios are variable, with Protohistoric rocks displaying 87 Sr/ 86 Sr 0.70711±0.70810, Ancient Historic 87 Sr/ 86 Sr 0.70665±0.70729, and Medieval Sr/ 86 Sr 0.70685±0.70803. Neodymium isotopic compositions in the interplinian rocks show a tendency to become slightly more radiogenic with age, from the Protohistoric ( 143 Nd/ 144 Nd 0.51240±0.51247) to Ancient Historic ( 143 Nd/ 144 Nd 0.51245± 0.51251). Medieval interplinian activity ( 143 Nd/ 144 Nd: 0.51250±0.51241) lacks meaningful internal trends. All the interplinian rocks have virtually homogeneous compositions of 207 Pb/ 204 Pb and 208 Pb/ 204 Pb in acid-leached residues ( 207 Pb/ 204 Pb

We studied the inland flight behavior of 46 radio-marked Marbled Murrelets (Brachyramphus marmoratus) in 2000 and 2001 in central California to determine how the frequency of inland flights varied among individuals and over time. All breeding murrelets regularly flew inland (mean 82% of daily surveys), but we observed considerable variation in the inland flight behavior of non-nesters. Non-nesters that were physiologically in breeding condition (potential breeders) regularly flew inland (90% of individuals; mean 41% of daily surveys), but non-nesters that were not in breeding condition (nonbreeders) rarely flew inland (20% of individuals; mean 1% of daily surveys). The mean percentage of surveys on which individual murrelets flew inland increased from 20% in 2000 to 61% in 2001, which was partly due to an increase in the percentage of breeders from 11% in 2000 to 50% in 2001. The frequency of inland flights was greatest during the incubation and chickprovisioning stages (100% in both stages), and lowest during the pre-and postbreeding stages (70% and 78%, respectively). Although the mean percentage of flights increased dramatically between years, the regional population estimate from at-sea surveys increased only 28% from 496 to 637 individuals during the same period, indicating that monitoring techniques such as radar that count inland flights are more likely to reflect annual variation in breeding effort than changes in regional population size. Moreover, the inland flight behavior of potential breeders indicates that radar surveys will overestimate breeding population size, even though the lack of inland flights by nonbreeders indicates that radar surveys will underestimate regional population size.

Two large sandy seas in northern China, the Taklamakan and Badanjilin deserts, were investigated for geochemical variations of soluble salts in aeolian sands. The aim was to explore factors influencing the composition and distribution of soluble salts in aeolian sands and their environmental implications. The total concentrations of soluble salt in the aeolian sands range between 0.14 and 1.32%, with pH ranging between 8.4 and 9.6, indicating a primary degree of salt accumulation and alkaline soil conditions in these regions. Sodium chloride and bicarbonate are the major salts. High inter-regional homogenization and small local differences in the chemical compositions and distributional patterns of salt occur in the two deserts. The spatial variations in salt content correlate with regional climatic parameters, such as precipitation and temperature. This suggests that the regional air temperature and moisture conditions of climate have a significant influence on the soluble salts in aeolian sands. The domination of sedimentation of soluble salts in aeolian sands deposited via atmospheric processes, which is heavily associated with dry deposition, is discussed. Case studies from the two deserts suggest that variations in salt content in sedimentary sequences, interlaid by aeolian and lacustrine sediments, should be interpreted with care if the aim is to reveal palaeo-environmental changes. To a certain extent, the two deserts, as inferred from the carbon-bearing salts and the alkalinity of the sandy soils, appear to have potential to provide a significant contribution to the global carbon cycle.

We summarized the temporal variation in populations of inland trout Salmo, Salvelinus, and Oncorhynchus spp. from streams in North America and determined the statistical power to detect trends over time. The coefficients of variation in abundance averaged 49% (SD ¼ 27%; range ¼ 15-108%) over time for all ages of trout. Temporal variation was lower when more age-classes were monitored, but whether abundance or biomass was more variable differed among populations. Detecting population trends was difficult when using the traditional a ¼ 0.05 criterion. For example, detecting a 5% annual decline with good power (1 -b ! 0.80) would require about 20 years if only one site were monitored. Even when a was relaxed to 0.20, 15 years were required to detect a 5% annual decline when the variation was average. Using a network of sites improved the ability to detect changes: a 5% annual decline at a ¼ 0.05 could be detected in 10 years when 30 sites were monitored. For high-value populations, it may require relaxing a to ensure that declines are detected, even if this increases the risk of claiming change when none has occurred and thus undertaking unnecessary management action. For example, a 5% annual decline could be detected with good power (!0.80) in 8 years when a network of 30 sites is monitored at a ¼ 0.20. Thus, biologists should monitor the least-variable component of a population, monitor a network of sites, and increase a for species of concern to ensure that real population trends are detected. Estimates of trend parameters (and their uncertainty) should be considered in addition to whether or not a statistical test for trend is significant. A pilot study or existing data can help estimate the variation that is typical of the population(s) to be monitored, determine whether trends can be reliably detected, and identify how much risk needs to be incurred to detect trends.

The bactericidal characteristics of nano-copper oxide or functionalized zeolite coated concrete pipes against Acidithiobacillus thiooxidans were studied by measuring the temporal variation of bacterial dry cell weight measurement, cellular Adenosine Triphosphate production, as well as oxygen uptake rate of the aforementioned bacterium. Uncorroded (UC), severely corroded (SC), and moderately corroded (MC) concrete pipes were electrochemically coated with a nano-copper oxide, while another uncorroded concrete pipe was used to apply functionalized zeolite coating (Z2). Specimens were characterized by field emission-scanning electron microscopy, and optical microscopy. Oxygen uptake rate of the bacterium was the highest in UC followed by the MC. Oxygen uptake rate and cellular Adenosine Triphosphate decreased progressively in Z2 and SC throughout the duration of the experiment due to decline in live bacterial cell. The maximum bacterial specific growth rate was 1.1 Â 10 À2 day À1 for both UC and MC, with a decay rates varying from 1.4 Â 10 À2 to 2.6 Â 10 À2 day À1 . The minimum concentration limits for the inhibition of the bacterium in the nano-copper oxide coated concrete pipes ranged from 2.3 mg to 2.6 mg Cu per mg dry cell weight.

Variations in molybdenum isotopic composition, spanning the range of ∼ 2.3‰ in the terms of 97 Mo/ 95 Mo ratio, have been measured in sediment cores from three lakes in northern Sweden and north-western Russia. These variations have been produced by both isotopically variable input of Mo into the lakes due to Mo isotopic heterogeneity of bedrock in the drainage basins and fractionation in the lake systems due to temporal variations in limnological conditions. Mo isotope abundances of bedrock in the lake drainage basins have been documented by analysis of Mo isotope ratios of a suite of molybdenite occurrences collected in the studied area and of detrital fractions of the lake sediment cores. The median .δ 97 Mo value of the investigated molybdenites is 0.26‰ with standard deviation of 0.43‰ (.n = 19), whereas the median .δ 97 Mo value of detrital sediment fractions from two lakes is -0.40‰ with standard deviation of 0.36‰ (.n = 15). The isotopic composition of Mo in the sediment cores has been found to be dependent on redox conditions of the water columns and the dominant type of scavenging phases. Hydrous Fe oxides have been shown to be an efficient scavenger of Mo from porewater under oxic conditions. Oxidative precipitation of Fe(II) in the sediments resulted in co-precipitation of Mo and significant authigenic enrichment at the redox boundary. In spite of a pronounced increase in Mo concentration associated with Fe oxides at the redox boundary the isotopic composition of Mo in this zone varies insignificantly, suggesting little or no isotope fractionation during scavenging of Mo by hydrous Fe oxides. In a lake with anoxic bottom water a chironomid-inferred reconstruction of O 2 conditions in the bottom water through the Holocene indicates that increased O 2 concentrations are generally associated with low .δ 97 Mo/ 95 Mo values of the sediments, whereas lowered O 2 contents of the bottom water are accompanied by relatively high .δ 97 Mo/ 95 Mo values, thus confirming the potential of Mo isotope data to be a proxy for redox conditions of overlying waters. However, it is pointed out that other processes including input of isotopically heterogeneous Mo and Mn cycling in the redox-stratified water column can be a primary cause of variations in Mo isotopic compositions of lake sediments.

Debris cover over glaciers greatly affects their rate of ablation and is a sensitive indicator of glacier health. This study focuses on estimation of debris cover over Samudratapu glacier, Chenab basin, Himalaya, using optical remote-sensing data. Remote-sensing image data of IRS-1C LISS-III (September 2001), IRS-P6 AWiFS (September 2004) and Terra ASTER (September 2004) along with Survey of India topographical maps (1963) were used in the study. Supervised classification of topographically corrected reflectance image data was systematically conducted to map six land-cover classes in the glacier terrain: snow, ice, mixed ice and debris, debris, valley rock, and water. An accuracy assessment of the classification was conducted using the ASTER visible/near-infrared data as the reference. The overall accuracies of the glacier-cover maps were found to range from 83.7% to 89.1%, whereas the individual class accuracy of debris-cover mapping was found to range from 82% to 95%. This shows that supervised classification of topographically corrected reflectance data is effective for the extraction of debris cover. In addition, a comparative study of glacier-cover maps generated from remote-sensing data (supervised classification) of September 2001 and September 2004 and Survey of India topographical maps (1963) has highlighted the trends of glacier depletion and recession. The glacier snout receded by about 756 m from 1963 to 2004, and the total glacier area was reduced by 13.7 km 2 (from 110 km 2 in 1963). Further, glacier retreat is found to be accompanied by a decrease in mixed ice and debris and a marked increase in debris-cover area. The area covered by valley rock is found to increase, confirming an overall decrease in the glacier area. The results from this study demonstrate the applicability of optical remote-sensing data in monitoring glacier terrain, and particularly mapping debris-cover area.

A comprehensive study of power spectral densities for time series data of blood pressure measured for four individuals, one healthy subject and three diseased subjects (pure autonomic failure (PAF), PAF complicated with supraventricular premature contraction, and multiple cerebral infarction with atrial fibrillation (Af)), was carried out using the computing program “MemCalc.” The whole spectrum for every time series indicates exponential characteristics until it levels off at a limit determined by the accuracy of the present measurement. The three-dimensional spectral array obtained from segment time series analysis showed a fine array of the fundamental and its harmonic modes, and was concluded to be a powerful tool for medical diagnosis. “Homeostasis” in living bodies is discussed on the basis of the present results. A new link between the nonlinear sciences and basic and/or clinical medicine found in the present study is sure to play an important role in medical diagnosis and pr...

A 4-yr study of spatial and temporal variability in the geochemistry of vadose groundwaters from caves within the Edwards aquifer region of central Texas offers new insights into controls on vadose groundwater evolution, the relationship between vadose and phreatic groundwaters, and the fundamental influence of soil composition on groundwater geochemistry. Variations in Sr isotopes and trace elements (Mg/Ca and Sr/Ca ratios) of dripwaters and soils from different caves, as well as phreatic groundwaters, provide the potential to distinguish between local variability and regional processes controlling fluid geochemistry, and a framework for understanding the links between climatic and hydrologic processes. The Sr isotope compositions of vadose cave dripwaters (mean 87 Sr/ 86 Sr ϭ 0.7087) and phreatic groundwaters (mean 87 Sr/ 86 Sr ϭ 0.7079) generally fall between values for host carbonates (mean 87 Sr/ 86 Sr ϭ 0.7076) and exchangeable Sr in overlying soils (mean 87 Sr/ 86 Sr ϭ 0.7088). Dripwaters have lower Mg/Ca and Sr/Ca ratios, and higher 87 Sr/ 86 Sr values than phreatic groundwaters. Dripwater 87 Sr/ 86 Sr values also inversely correlate with both Mg/Ca and Sr/Ca ratios. Mass-balance modeling combined with these geochemical relationships suggest that variations in fluid compositions are predominantly controlled by groundwater residence times, and water-rock interaction with overlying soils and host aquifer carbonate rocks. Consistent differences in dripwater geochemistry (i.e., 87 Sr/ 86 Sr, Mg/Ca, and Sr/Ca) between individual caves are similar to compositional differences in soils above the caves. While these differences appear to exert significant control on local fluid evolution, geochemical and isotopic variations suggest that the controlling processes are regionally extensive. Temporal variations in 87 Sr/ 86 Sr values and Mg/Ca ratios of dripwaters from some sites over the 4-yr interval correspond with changes in both aquifer and climatic parameters. These results have important implications for the interpretation of trace element and isotopic variations in speleothems as paleoclimate records, as well as the understanding of controls on water chemistry for both present-day and ancient carbonate aquifers.

A strong earthquake with a magnitude of 7.6 (M L = 7.3) occurred on September 21, 1999, in central Taiwan. In order to discern any potential precursors before this earthquake, geomagnetic data at Lunping (LNP), Taiwan, Geomagnetic Observatory situated 100 km from the epicenter are examined using two methods, i.e., the traditional induction arrows and complex demodulation. Our results show that the remarkable temporal variation of real induction arrows appear to be strong prior to the great earthquake over the previous 24 months. After the great earthquake, the magnitudes of induction arrows decreased to the normal (mean of 8 years) levels. In other words, the direction of real induction arrows of the periods 30 and 20 min rotated 85°and 40°anticlockwise, respectively, before the Chi-Chi earthquake and returned to mean direction of last 10 years after the earthquake. A horizontal source field model using the finite difference method for 3-D shows that the variation of the real induction arrows might be ascribed to the conductivity variation body, which is 5 km buried at the epicenter area of the Chi-Chi earthquake, changing its conductivity from 0.002S/m to 0.06 S/m. The ratios of modulus (demodulated by using the complex demodulation method) over a period 12, and 8 h relative to the period of 24 h reveal a remarkable change that appeared 4-5 months prior to this strong earthquake. They increased gradually from the beginning of 1999 to August 1999 and decreased again to a (8 years) mean level after the strong earthquake occurrence. We consider that the variation of the induction arrow might be ascribed to the conductivity anomaly, which is buried 5 km at the south-east side of LNP with a conductivity change of 0.06 S/m. We propose that this elevation might be related to the preparation process of the great earthquake.

We suggest a visual analytics framework for the exploration and analysis of spatially and temporally referenced values of numeric attributes. The framework supports two complementary perspectives on spatio-temporal data: as a temporal sequence of spatial distributions of attribute values (called spatial situations) and as a set of spatially referenced time series of attribute values representing local temporal variations. To handle large amounts of data, we use the Self-Organizing Map (SOM) method, which groups objects and arranges them according to similarity of relevant data features. We apply the SOM approach to spatial situations and to local temporal variations and obtain two types of SOM outcomes, called space-in-time SOM and time-in-space SOM, respectively. The examination and interpretation of both types of SOM outcomes are supported by appropriate visualization and interaction techniques. The paper describes the use of the framework by an example scenario of data analysis. We also discuss how the framework can be extended from supporting explorative analysis to building predictive models of the spatio-temporal variation of attribute values. We apply our approach to phone call data showing its usefulness in real-world analytic scenarios.

Estudos sobre a climatologia das precipitações no Estado do Pará são essenciais para o planejamento das atividades agrícolas. A variação da precipitação anual e sazonal no Estado do Pará foi analisada com base em séries históricas de 23 anos (1976-1998) de dados diários de chuva. A análise foi realizada para 31 localidades do Estado do Pará, sendo os resultados representados em mapas com a utilização de técnicas de sistemas de informações geográficas (SIG). A variabilidade da precipitação anual e sazonal foi caracterizada com base no coeficiente de variação e no índice de variabilidade interanual relativo. A variação desses coeficientes para a precipitação anual no Estado do Pará foi de 15 a 30%. As características mensais da estação chuvosa, em termos de início, fim e duração, foram determinadas utilizando-se o critério proposto por KASSAM (1979). A variação entre as datas de plantio precoces e tardias corresponderam aos decêndios identificados pelos dias julianos 309319 e 353363, ...

This study aimed to characterize spatial/temporal variations of ambient volatile organic compounds (VOCs) using a community-scale monitoring approach and identify the main sources of concern in Paterson, NJ, an urban area with mixed sources of VOCs. VOC samples were simultaneously collected from three local source-dominated (i.e., commercial, industrial, and mobile) sites in Paterson and one background site in Chester, NJ (located ,58 km southwest of Paterson). Samples were collected using the EPA TO-15 method from midnight to midnight, one in every sixth day over one year. Among the 60 analyzed VOCs, ten VOCs (acetylene, benzene, dichloromethane, ethylbenzene, methyl ethyl ketone, styrene, toluene, m,pxylene, o-xylene, and p-dichlorobenzene) were selected to examine their spatial/temporal variations. All of the 10 VOCs in Paterson were significantly higher than the background site (p,0.01). Ethylbenzene, m,p-xylene, o-xylene, and pdichlorobenzene measured at the commercial site were significantly higher than the industrial/mobile sites (p,0.01). Seven VOCs (acetylene, benzene, dichloromethane, methyl ethyl ketone, styrene, toluene, and p-dichlorobenzene) were significantly different by season (p,0.05), that is, higher in cold seasons than in warm seasons. In addition, dichloromethane, methyl ethyl ketone, and toluene were significantly higher on weekdays than weekend days (p,0.05). These results are consistent with literature data, indicating the impact of anthropogenic VOC sources on air pollution in Paterson. Positive Matrix Factorization (PMF) analysis was applied for 24-hour integrated VOC measurements in Paterson over one year and identified six contributing factors, including motor vehicle exhausts (20%), solvents uses (19%), industrial emissions (16%), mobile+stationery sources (12%), small shop emissions (11%), and others (22%). Additional locational analysis confirmed the identified sources were well matched with point sources located upwind in Paterson. The study demonstrated the community-scale monitoring approach can capture spatial variation of VOCs in an urban community with mixed VOC sources. It also provided robust data to identify major sources of concern in the community.

In this paper, a combined cross-section and time-series econometric analysis of Spanish regional growth is presented. This analysis operates with a database where the number of cross-sectional units is small for a typical panel of data, while the time dimension is clearly dominant. First, using recent techniques in the econometric analysis of panel data (both panel unit root and panel co-integration tests), a co-integrating relationship between the level of regional output and the level of regional input factors is found, and the steady-state equilibrium production function is estimated. Second, a dynamic spatio-temporal panel error correction model is used in order to describe the short-run regional growth adjustment process in space and time. As conclusion, it is possible to identify significant spatial effects in the Spanish regional growth after controlling for temporal variation of the implied variables.

Supervised learning networks based on a decisionbased formulation are explored. More specifically, a decisionbased neural network (DBNN) is proposed, which combines the perceptron-like learning rule and hierarchical nonlinear network structure. The decision-based mutual training can be applied to both static and temporal pattern recognition problems. For static pattern recognition, two hierarchical structures are proposed: hidden-node and subcluster structures. The relationships between DBNN's and other models (linear perceptron, piecewiselinear perceptron, LVQ, and PNN) are discussed. As to temporal DBNN's, model-based discriminant functions may be chosen to compensate possible temporal variations, such as waveform warping and alignments. 'Qpical examples include DTW distance, prediction error, or likelihood functions. For classification applications, DBNN's are very effective in computation time and performance. This is confirmed by simulations conducted for several applications, including texture classification, OCR, and ECG analysis.

We studied within-tree variaton in density and mortality of the leaf miner, Cameraria sp. nov., on Emory oak. Miner densities were lower in the peripheral than the central parts of trees. Following tagged mined and unmined leaves revealed that peripheral leaves fall sooner than central leaves and that more Cameraria mining peripheral leaves die due to abscission than those mining central leaves. We discuss factors that might influence interactions between leaf miners and abscission of the host-leaves they attack.