bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Imaging of Infiltration, Root Growth, and Root Water Uptake via Neutron Radiography
Authors: Oswald Sascha E. , Menon Manoj , Carminati Andrea , Vontobel Peter , Lehmann Eberhard , Schulin Rainer
Published: August 2008

Water infiltration into vegetated soils is affected by interactions between soil properties and plant activity. Water uptake by plant roots depends on the soil hydraulic properties and infiltration rate. In turn, roots are important water movers and induce nonuniform water content distributions with consequent impact on the infiltration rate. Our goal was to use neutron radiography to investigate root water uptake during rapid infiltration events and subsequent water redistribution. Neutron radiography is an imaging technique capable of measuring with high spatial and temporal resolution root density, soil structure, and water distributions in the vicinity of roots. We used time‐series neutron radiography to image infiltration events in 0.17‐ by 0.15‐ by 0.013‐m boxes filled with a sand mixture and that contained either lupine (Lupinus L.) or maize (Zea mays L.) plants. We measured four replications at two stages of plant growth. Neutron radiography can detect small variations in water content with high accuracy and high spatial and temporal resolution. Due to their high water content, roots were easily visible in the radiograms before infiltration. Following calibration, we quantified the water content in the sample during and after each infiltration event. Effects of soil heterogeneities such as thin soil layers were visible, as was water uptake by roots. We observed lower water contents along the main root of lupine during the early stage of infiltration, and slower and more diffuse uptake during the later stages of water redistribution, when the wetting front had propagated downward and the water content in the soil decreased. The observed root water uptake was not uniform but rather was localized in certain regions. For maize we observed a loss of water mainly in the upper part of the root system, closer to the stem rather than at root tips.
Effect of Flow Regime on Physical Nonequilibrium Transport in Unsaturated Porous Media
Authors: Mayer Alex , Sandman Todd , Breidenbach Michael
Published: August 2008

The mobile–immobile (MIM) conceptual model attributes physical nonequilibrium to the presence of practically immobile water held in pore spaces and mass transfer between mobile, flowing water and the immobile water. The goal of this study was to explore the relationships between MIM transport parameters and state variables as a function of flow and porous medium characteristics. The investigation involved conducting a series of solute tracer experiments under steady‐state and transient flow regimes across a range of pore velocities and water contents and in two unstructured porous media. Dispersivities obtained under transient conditions were higher than steady‐state dispersivities only for the more uniform porous medium. There was no significant difference between scaled mobile water contents obtained for the transient experiments and those obtained for the steady‐state experiments for either porous medium. Mass transfer coefficients for the transient experiments were consistently higher than those estimated for the steady‐state experiments for the more uniform porous medium. These results indicate that the flow regime (transient vs. steady‐state conditions) may be significant for physical nonequilibrium transport but depends on the porous medium characteristics. The results imply that conceptual models of physical nonequilibrium transport may need to be refined and, in some cases, models need to be developed to relate transport parameters to flow conditions.
Field Calibration Accuracy and Utility of Four Down‐Hole Water Content Sensors
Authors: Mazahrih Naem Th. , Katbeh‐Bader Nedal , Evett Steven R. , Ayars James E. , Trout Thomas J.
Published: August 2008

Soil water balance studies of profile water content, changes in stored water, crop water use, and spatial variability of water content and use require accurate soil water determinations that are representative across at least field‐sized areas. Several capacitance and other electromagnetic (EM) sensors are commercially available for use in access tubes to determine profile water content. Scientists and practitioners need to know if they are suitable replacements for the neutron moisture meter (NMM) in terms of accuracy and utility. In a field calibration of the NMM and three EM sensors in a Panoche clay loam soil in the San Joaquin Valley of California, three access tubes were installed in a site dried by plant water uptake and three were installed in an adjacent plot wetted to saturation and allowed to drain. Sensors were read and volumetric water content samples taken at several depths at each access tube; calibrations of water content vs. sensor reading were calculated for each depth and for appropriate combinations of depths by regression analysis. Calibrations for the EM sensors changed rapidly with depth, often requiring separate calibrations for every 10‐ or 20‐cm depth range, and were relatively inaccurate (RMSE of 0.015–0.063 m3 m−3). The NMM is the preferred choice for accurate profile water content and change in storage determination. In general, the EM sensors cannot be recommended for profile water content or change in storage determinations due to their relatively less accurate (larger RMSE values) calibrations, strong dependence of calibration slopes and exponents on depth, probable dependence of the calibrations on soil bulk electrical conductivity (BEC), and the likelihood of BEC changes in the field during the irrigation season.
'Suvetar' and 'Valotar' - new strawberry cultivars (Research Note)
Authors: HIETARANTA T. , PARIKKA P.
Published: August 2008

The strawberry (Fragaria × ananassa) cultivars Suvetar and Valotar have been released from the breeding programme of MTT Agrifood Research Finland. Both new cultivars overwintered as well as the control cultivars Jonsok and Polka. Suvetar overwintered even better than Polka. Suvetar was produced from the cross Polka × Emily. It scored better than the control cultivars for sensory assessed skin resistance. Measured fruit firmness of Suvetar was not significantly different from that of Polka, but was better than Jonsok. Valotar originates from a cross between Jewel and Senga Sengana. Its measured fruit firmness was better than that of Jonsok and Polka. Considering sensory assessments, the good firmness seems to be largely due to good skin resistance. The fresh flavour, yield, fruit size and fruit appearance of Suvetar and Valotar, together with improved fruit firmness, make both the new varieties suitable for the fresh fruit market.;
Contrasting extreme runoff events in areas of continuous permafrost, Arctic Alaska
Authors: Kane Douglas L. , Hinzman Larry D. , Gieck Robert E. , McNamara James P. , Youcha Emily K. , Oatley Jeffrey A.
Published: August 2008

Spring snowmelt floods in the Arctic are common and can be expected every year, mainly because of the extensive snow cover that ablates relatively quickly. However, documentation of extreme flows (both low and high) in the Arctic is lacking in part because extreme flows are relatively rare and gauging sites are very sparse, with most of short duration. In the nested Kuparuk River research watersheds on the North Slope of Alaska, two large summer floods have been observed (July 1999 and August 2002) in the headwaters; these high flows are contrasted to the low flows (drought conditions) observed in the summers of 2005 and 2007. It is clear that the continuous permafrost and the limited near-surface storage in the shallow active layer are responsible for both the high and low flow responses. Or, stated another way, the active layer is a poor buffer to both floods and droughts. When contrasting summer floods with snowmelt floods, it is clear from flood frequency analyses that the smaller, high-gradient headwater basins will be dominated by summer floods while those watersheds draining the low gradient coastal plain will be dominated by snowmelt floods. The two summer floods in the headwaters had flows that were three to four times greater than the largest measured snowmelt flood, while on the coastal plain the 2002 summer storm for the whole of the Kuparuk River only produced the maximum summer runoff of record that was about 1/4 of the maximum snowmelt flood. So, on the coastal plain and even for the Greater Kuparuk River that drains across the coastal plain, snowmelt floods dominate. Drought conditions prevail in summers when the limited surface water storage in the active layer and surface water bodies is depleted because evapotranspiration exceeds precipitation.
Hillslope hydrological linkages: importance to ponds within a polar desert High Arctic wetland
Authors: Abnizova Anna , Young Kathy L.
Published: August 2008

Arctic wetland environments are considered to be sensitive to ongoing climate change but they have received limited attention despite their ecological importance. To understand and quantify better the hydrologic processes which are leading to the sustainability and demise of High Arctic ponds, a water balance framework was employed on several ponds situated in two broad geomorphic areas near Creswell Bay, Somerset Island (72°43′N, 94°15′W). These ponds are also linked to an upland area through a range of linear features: stream, late-lying snowbeds and frost cracks. This study assesses the importance of these features with respect to the sustainability of these wetland ponds.

A pond's position in the moraine landscape was important in determining its connectivity to a nearby stream and late-lying snowbed. Close proximity to a stream draining a large upland snow-covered catchment ensures steady water levels during the snowmelt period. Once discharge slows, a late-lying snowbed continues to supply the pond and others nearby with meltwater. The deeply thawed, sandy coastal zone is characterized by frost cracks, which contribute to the patterned ground of this wetland zone. These cracks, when situated downslope of ponds, function primarily as ‘sinks’ and serve to deprive small and medium-sized ponds of water during dry periods, often leading to their desiccation.
Preparation and characterization of diethylnicotinamidium perchlorate
Authors: Ondrejkovičová Iveta , Mikloš Dušan , Štefániková Silvia
Published: August 2008

The title compound is the first example of N,N′-diethylnicotinamidium, [denaH]+, salt which has been characterized by X-ray analysis and IR spectra. [denaH]ClO4 was obtained from the reaction mixture prepared from N,N′-diethylnicotinamide (dena) and Fe(ClO4)3 in ethanol without any addition of HClO4. The proton required for protonation of dena is produced by hydrolysis of aquairon(III) cations. In the crystal structure, cations and anions are held together by ionic interactions. The cations are linked to each other by pyridinium-carbonyl N-H⋯O=C hydrogen bonds and an infinite linear chain along axis a is formed.
ICP MS analysis and classification of potable, spring, and mineral waters
Authors: Kraic Filip , Mocák Ján , Fiket Željka , Kniewald Goran
Published: August 2008

Ninety-three water samples were categorized into five classes as the tap, mineral, mineral carbonated, spring, and spring carbonated water, or, alternatively, into four or three categories — with all spring water samples together or as tap, mineral, and spring water, respectively. The samples originated from four European countries and thirty-one chemical descriptors (concentrations of contained elements) were used for their characterization. Analytical measurements were performed by mass spectrometry with inductively coupled plasma, allowing the determination of individual nuclides. Different water categories were characterized by chemometrical techniques, mainly by principal component analysis, cluster analysis, linear and quadratic discriminant analyses, correlation analysis, and ANOVA. Their role was to discover the nuclides important for distinct characterization of individual water categories as well as to assess the possibility of water samples from different countries being recognized from the increased/decreased content of some elements. The enhanced content of Cd, Cu, Zn, Bi, and Fe was characteristic for tap water samples, whilst mineral water samples were characterized by the elevated concentration of Sr, Li, B, Ni, Co, As, and Sb. The classification results were successful and close to 100 %, which was proved by the leave-one-out cross-validation procedure.
Application of Conceptual Rainfall-Runoff Model METQ for Simulation of Daily Runoff and Water Level: The case of the Lake Burtnieks Watershed
Authors: Apsīte Elga , Zīverts Ansis , Bakute Anda
Published: August 2008

Application of Conceptual Rainfall-Runoff Model METQ for Simulation of Daily Runoff and Water Level: The case of the Lake Burtnieks Watershed

In this study a conceptual rainfall-runoff METQ model—the latest version METQ2007BDOPT—was applied to simulate the daily runoff and water level of the Lake Burtnieks watershed from 1990 to 1999. The model structure and parameters were basically the same as in the METQ98, with some additional improvements and semi-automatical calibration performance. Model calibration was done for four rivers and one lake gauging station. The results of calibration showed a good correlation between the measured and simulated daily discharges. The Nash-Sutcliffe efficiency R2 varied from 0.90 to 0.58 and correlation coefficient r from 0.95 to 0.83. The highest values of R2 = 0.90 and r = 0.95 were obtained for the River Salaca and the lowest R2 = 0.53 and r = 0.83 for Lake Burtnieks. We observed some relationships between the model parameter values and physiographic characteristic of the sub-catchments.
Experimental Study of Peat Humification Indicators
Authors: Šīre Jānis , Kļaviņš Māris , Purmalis Oskars , Melecis Viesturs
Published: August 2008

Experimental Study of Peat Humification Indicators

An important parameter of organic matter in soils, peat, and fossil-carbon-containing deposits is their decomposition degree, which describes their transformation intensity—the humification degree of original living organic matter. In this article approaches to the analysis of humification degree are thoroughly described and14C dated peat columns extracted from several bogs in Latvia are investigated and compared. A new humification indicator is suggested: the ratio of the total amount of organic matter in peat in respect to the amount of humic substances.
Soil Pollution with Trace Elements in Territories of Military Grounds in Latvia
Authors: Kokorīte Ilga , Kļaviņš Māris , Šīre Jānis , Purmalis Oskars , Zučika Aija
Published: August 2008

Soil Pollution with Trace Elements in Territories of Military Grounds in Latvia

Contamination of land used for military activities can significantly differ from that of municipal and industrial land, both in the intensity and type. Largely this is due to the intensity of activities even in a comparatively large surface area, and also by use of substances and materials not common in civil practice. Pollution from military grounds can affect not only soldiers, but also adjacent territories and water resources. In this study, concentrations of trace elements in the soil, water and higher vegetation in former Soviet army military territories were surveyed. The presence of point sources was found, and in a few cases the pollution is intensively spreading into deeper soil horizons and groundwater.
Potential Impact of Climate Change on Aquatic Vegetation of River Salaca, Latvia
Authors: Grīnberga Laura , Spriņge Gunta
Published: August 2008

Potential Impact of Climate Change on Aquatic Vegetation of River Salaca, Latvia

Species diversity and cover of aquatic macrophytes were investigated in the River Salaca in 2007. In total 24 different taxa were found. Schoenoplectus lacustris was the dominant species, Sagittaria sagittifolia, Nuphar lutea, Nymphaea candida, Butomus umbellatus and different Potamogeton species were frequent. Cover of macrophytes varied in the river between 10-90%, maximum in-stream cover reached in rapidly flowing sites. Comparison of total cover of macrophytes in 1986 and 2002 surveys of several stretches was done. Causes for the changes are discussed. The increasing growth of aquatic vegetation in the River Salaca have been related to climatic factors—higher mean annual air temperatures, earlier springs and decrease in the period of ice cover in winter.
Landscape Ecological Structure in the Eastern Part of the North Vidzeme Biosphere Reserve, Latvia
Authors: Tērauds Aivars , Nikodemus Oļgerts , Rasa Inga , Bells Simons
Published: August 2008

Landscape Ecological Structure in the Eastern Part of the North Vidzeme Biosphere Reserve, Latvia

Latvia is a country where the forest area has increased and habitat fragmentation has reversed compared with many other European countries. In order to examine the effect of this expansion on biodiversity, vegetation maps dating from 2002 and the years 1930-1936 were used for comparative landscape structure analyses while archive materials from forest plans, and data from the national forest management database were used for land use analysis. Four landscape ecoregions in the eastern side of the North Vidzeme Biosphere Reserve were selected for analysis. Landscape structure indicators derived from landscape ecology were used for the ecological assessment of land use changes. The total number of forest patches had decreased over the study period, but mean patch size had increased for all types of landscape element. This general change was found to vary between different landscape units in the study area. The biggest change in the area of forest patches occurred in the Rūjiena drumlin field, where the amount of forest patches decreased least and forest area increased the most. This study showed that the internal structure of the forest matrix changed substantially. This finding has implications for biodiversity protection if this trend of land use change continues.
Effect of Burst Frequency and Duration of Kilohertz-Frequency Alternating Currents and of Low-Frequency Pulsed Currents on Strength of Contraction, Muscle Fatigue, and Perceived Discomfort
Authors: Laufer Yocheved , Elboim Michal
Published: August 2008

Background

Low-frequency pulsed currents (LPCs) and kilohertz-frequency alternating currents (KACs) are used clinically to augment muscle contractions. Treatment effectiveness may be enhanced by selecting stimulation parameters that evoke the strongest contractions with minimal discomfort and fatigue.

Objective

The objective of this study was to compare maximally induced strength (force-producing capacity) of contractions, muscle fatigue, and discomfort associated with an LPC and with 3 KACs differing in frequency and duration of burst modulation.

Design

This was a repeated-measures trial, with randomized order of current presentation.

Setting

The study was conducted in the physical therapy laboratory at the University of Haifa.

Subjects

Twenty-six volunteers without impairments, with a mean age of 27.4 years (SD=5.0, range=21–45), participated.

Intervention

All currents were applied in separate sessions to the wrist extensors of each subject. Currents consisted of an LPC with a 50-Hz pulse frequency and 3 KACs with a 2.5-kHz carrier frequency, including the “Russian current” (RC) burst modulated at 50 Hz with 25 cycles per burst and 2 currents burst modulated at 20 or 50 Hz with 10 cycles per burst.

Measurement

The maximal electrically induced isometric force, the force integral of 21 electrically induced consecutive contractions, and the degree of discomfort were recorded.

Results

Force of contraction was not affected by type of current. The LPC was least fatiguing, and the RC was most fatiguing, with the 2 other KACs having an intermediate effect. Degree of discomfort was higher with the KAC modulated at 20 Hz.

Conclusions

When comfort, strength, and fatigue are considered jointly, the LPC is advantageous. Electrically induced fatigue is affected by the number of cycles per second, rather than the number of bursts per second.
Short Term Effects on Bone Quality Associated with Consumption of Soy Protein Isolate and Other Dietary Protein Sources in Rapidly Growing Female Rats
Authors: Chen Jin-Ran , Singhal Rohit , Lazarenko Oxana P. , Liu Xiaoli , Hogue William R. , Badger Thomas M. , Ronis Martin J. J.
Published: August 2008

Beneficial effects of soy protein consumption on bone quality have been reported. The effects of other dietary protein sources such as whey protein hydrolysate (WPH) and rice protein isolate (RPI) on bone growth have been less well examined. The current study compared effects of feeding soy protein isolate (SPI), WPH and RPI for 14 d on tibial bone mineral density (BMD) and bone mineral content (BMC) in intact and ovariectomized (OVX) rapidly growing female rats relative to animals fed casein (CAS). The effects of estrogenic status on responses to SPI were also explored. Tibial peripheral quantitative computerized tomography (pQCT) showed all three protein sources had positive effects on either BMD or BMC relative to CAS ( P < 0.05), but SPI had greater effects in both intact and OVX female rats. SPI and E2 had positive effects on BMD and BMC in OVX rats ( P < 0.05). However, trabecular BMD was lower in a SPI + E2 group compared to a CAS + E2 group. In OVX rats, SPI increased serum bone formation markers, and serum from SPI-fed rats stimulated osteoblastogenesis in ex vivo. SPI also suppressed the bone resorption marker RatLaps ( P < 0.05). Both SPI and E2 increased alkaline phosphatase gene expression in bone, but only SPI decreased receptor activator of nuclear factor-κB ligand (RANKL) and estrogen receptor gene expression ( P < 0.05). These data suggest beneficial bone effects of a soy diet in rapidly growing animals and the potential for early soy consumption to increase peak bone mass.
Acetaminophen Is Cardioprotective Against H2O2-Induced InjuryIn Vivo
Authors: Jaques-Robinson Kathryn M. , Golfetti Roseli , Baliga Sunanda S. , Hadzimichalis Norell M. , Merrill Gary F.
Published: August 2008

Here we report our ongoing investigation of the cardiovascular effects of acetaminophen, with emphasis on oxidation-induced canine myocardial dysfunction. The objective of the current study was to investigate whether acetaminophen could attenuate exogenous H2O2-mediated myocardial dysfunction in vivo. Respiratory, metabolic, and hemodynamic indices such as left ventricular function (LVDP and ±dP/dtmax), and percent ectopy were measured in anesthetized, open-chest dogs during intravenous administration of 0.88 mM, 2.2 mM, 6.6 mM H2O2. Following 6.6 mM H2O2, tissue from the left ventricle was harvested for electron microscopy. Left ventricular function did not vary significantly between vehicle and acetaminophen groups under baseline conditions. Acetaminophen-treated dogs regained a significantly greater fraction of baseline function after high concentrations of H2O2than vehicle-treated dogs. Moreover, the incidence of H2O2-induced ventricular arrhythmias was significantly reduced in the acetaminophen-treated group. Percent ectopy following 6.6 mM concentrations of H2O2was 1 ± 0.3 vs. 0.3 ± 0.1 ( P < 0.05) for vehicle- and acetaminophen-treated dogs, respectively. Additionally, electron micrograph images of left ventricular tissue confirmed preservation of tissue ultrastructure in acetaminophen-treated hearts when compared to vehicle. We conclude that, in the canine myocardium, acetaminophen is both functionally cardioprotective and antiarrhythmic against H2O2-induced oxidative injury.
Activated Protein C Protection from Lung Inflammation in Endotoxin-Induced Injury
Authors: Pirrone Federica , Mazzola Silvia M. , Pastore Camilla , Paltrinieri Saverio , Sironi Giuseppe , Riccaboni Pietro , Viola Manuela , Passi Alberto , Clement Maria G. , Albertini Mariangela
Published: August 2008

We studied the protection of recombinant human activated protein C (rhAPC) in endotoxin-induced lung inflammation and injury and whether this effect is correlated with modulation of lung matrix metalloproteinase (MMP) activity. We randomly assigned 12 Large White pigs to receive intravenous Escher-ichia coli lipopolysaccharide (LPS; 40 μ g/kg/hr), rhAPC (24 μ g/ kg/hr), or both. We monitored respiratory mechanics and function, cell counts, and cytokine concentrations in bron-choalveolar lavage fluid (BALF). Lung samples were collected for the zymography of MMP-2 and MMP-9 activities and for histology. In septic pigs, rhAPC decreased proMMP-9 release as well as MMP-9 activation, and increased proMMP-2 presence without any evident activation compared with specimens that were given LPS alone. In addition, lung injury in rhAPC-treated animals was significantly attenuated, as shown by higher respiratory compliance, delayed increase in tumor necrosis alfa and interleukin-1β as well as neutrophil recruitment in the BALF, reduced lung edema, and histologic changes. In conclusion, rhAPC is beneficial in acute lung injury, and the protection may depend, at least in part, on modulation of MMP-2/9 activity.
Refractoriness of the Sheep Superior Vena Cava Myocardial Sleeve
Authors: Zhao Cuimei , Qi Jie , Liu Xingyuan , Chen Huaizhi , Li Jun , Liu Yi , Liang Lei , Zhang Yangyang , Xiao Junjie , Li Li , Peng Luying , Xu Jiahong , Ma Jun , Yang Ying , Wu Xianzheng , Chen Yi-Han
Published: August 2008

The cardiomyocytes in the superior vena cava (SVC) myocardial sleeve have distinct action potentials and ionic current profiles, but the refractoriness of these cells has not been reported. Using standard intracellular microelectrode techniques, we demonstrated in sheep that the effective refractory period (ERP) of the cardiomyocytes in the SVC (114.7 ± 6.5 ms) is shorter than that in the inferior vena cava (IVC) (166.7 ± 6.2 ms), right atrial free wall (RAFW) (201.0 ± 6.0 ms) and right atrial appendage (RAA) (203.1 ± 5.8 ms) ( P < 0.05). The right atrial cardiomyocyte ERP was heterogeneously shortened by acetylcholine, a muscarinic type 2 receptor (M2R) agonist. After perfusion with 15 μM acetylcholine, the shortest ERP occurred in the SVC (the ERP in the SVC, IVC, RAFW and RAA was 53.6 ± 2.7, 98.9 ± 2.2, 121.8 ± 6.0 and 109.7 ± 5.1 ms, respectively; P < 0.05). Carbachol (1 μM), another M2R agonist, produced a similar effect as acetylcholine. Furthermore, we used methoctramine, a M2R blocker, 4-DAMP, a muscarinic type 3 receptor (M3R) blocker, and tropicamide, a muscarinic type 4 receptor (M4R) blocker to inhibit the acetylcholine-induced ERP shortening of SVC cardiomyocytes, and found that the 50% inhibitory concentration for methoctramine, 4-DAMP and tropicamide was 5.91, 45.72 and 80.34 nM, respectively. Therefore, we conclude that the sheep SVC myocardial sleeve is a unique electrophysiological region of the right atrium with the shortest ERP both under physiological condition and under cholinergic agonist stimulation. M2R might play a major role in the response of the SVC myocardial sleeve to parasympathetic nerve tone. The association between the distinct refractoriness in SVC and atrial fibrillation originating from the region deserves further investigation.
Hematologic and Metabolic Effects of Dietary Supplementation with Agaricus sylvaticus Fungi on Rats Bearing Solid Walker 256 Tumor
Authors: Taveira Vanessa Cunha , Novaes Maria Rita Carvalho Garbi , dos Anjos Reis Marcelo , da Silva Monique Fernandes
Published: August 2008

Background: Many mushrooms have been used since ancient times for their nutritional and therapeutic properties. Alterations of hematologic parameters are commonly observed in patients with cancer, mainly due to the presence of some inflammatory mediators that have hemolytic effects, and yet can stimulate white blood cell release. Abnormalities in biochemical parameters are also found due to alterations in carbohydrate, protein, and lipid metabolism. Objective: The aim of the present study was to evaluate the effects of Agaricus sylvaticus on hematologic and biochemical parameters of rats inoculated with Walker 256 tumor. Methods: The animals were divided into 4 groups, with 20 in each group. Group 1 was inoculated with Walker 256 tumor and treated with A. sylvaticus. Group 2 was inoculated with Walker 256 tumor and administered a placebo solution. Group 3 was not inoculated with the tumor and was treated with A. sylvaticus, and Group 4 was not inoculated with the tumor and was administered a placebo solution. The rats were sacrificed after 12 days of treatment, and blood was collected following heart sectioning. Results: Statistically significant differences between Groups 1 and 2 were observed in red blood cell count, hematocrit, hemoglobin, C-reactive protein, urea, and triglyceride levels. No significant differences between these two groups were noted in hematimetric indices, leukocyte counts, creatinine, and glucose levels. No significant differences in hematologic and biochemical parameters were noted between Groups 3 and 4. Conclusion: A. sylvaticus is able to reduce anemia and improve biochemical parameters in animals with cancer and has no adverse effects on the blood cells of healthy animals.
In Vitro and In Vivo Anti-Allergic Effects of Arctium lappa L.
Authors: Knipping Karen , van Esch Elisabeth C. A. M. , Wijering Selva C. , van der Heide Sicco , Dubois Anthony E. , Garssen Johan
Published: August 2008

The discovery of drugs that can be used for the treatment of allergic disease is important in human health. Arctium lappa Linne (Compositae) (AL) has been used as a traditional medicine in Brazil and throughout Asia and is known to have an anti-inflammatory effect. In this study, the inhibitory effects of AL on degranulation and the release of mediators as well as on inhibition of cys-leukotriene biosynthesis by basophils were investigated. AL was selected out of 10,000 herbal extracts in a set-up for high throughput screening in which the degree of degranulation was monitored by the release of β-hexosaminidase from rat basophil leukemia (RBL-2H3) cells. The AL extract significantly reduced degranulation and biosynthesis of cys-leukotrienes of human basophils in peripheral blood mono-nuclear cells (PBMCs) (50% inhibitory concentration [IC50] = 8.3 and 11.4 μg/ml, respectively). Viability and metabolic activity of the PBMCs were not affected. Although arctiin, the active component of AL that has been described in the literature, was not able to reduce degranulation in RBL-2H3 cells, a single high-performance liquid chromatography (HPLC) fraction from the AL extract inhibited β-hexosaminidase release (IC50 = 22.2 μg/ml). Topical administration of an aqueous extract of AL (5 mg/ear) on the ear of whey-sensitized mice 4 hrs before challenge with whey in the ear inhibited acute ear swelling by 50% in an in vivo cow’s milk allergic model. The extract had no effect in this model when administered orally. In conclusion, the active component present in the active HPLC fraction of the AL extract was able to significantly reduce the release of inflammatory mediators through inhibition of degranulation and cys-leukotriene release in vitro. In addition, this active component was able to inhibit acute skin response in mice in vivo, indicating that AL is a very promising natural component for use in anti-allergic treatment.
The Effect of Terguride in Carbon Tetrachloride–Induced Liver Fibrosis in Rat
Authors: Hauso Øyvind , Gustafsson Björn I. , Nordrum Ivar S. , Waldum Helge L.
Published: August 2008

Background: Hepatic stellate cells (HSCs) are considered to be of vital importance in the pathogenesis of liver fibrosis. In vitro studies have demonstrated antiproliferative effects of 5-hydroxytryptamine2 (5-HT2, serotonin) receptor antagonists upon HSCs. Terguride, recognized as a partial dopamine agonist, also has potent 5-HT2 receptor antagonist qualities and has been shown to prevent serotonin-induced organ changes and fibrosis in rats. Aim: In the current study, the carbon tetrachloride (CCL4) hepatic fibrosis rat model was used in combination with daily administration of terguride to evaluate potential preventive effects of a 5-HT2 receptor antagonist upon liver fibrosis. Materials and Methods: Forty rats (Sprague-Dawley) were included in the study. Twelve animals received terguride in combination with CCL4 and 12 animals were given only CCL4. The remaining 16 animals served as model controls. The extent of fibrosis was evaluated by liver weight, histologic analysis, biochemical analysis, and α-smooth muscle actin (α-SMA) immunohistochemistry. Results: There were no significant differences in liver weight, hydroxyproline content, serum alanine and aspartate transaminases, serum hyaluronic acid, or α-SMA immunostaining between rats treated with terguride in combination with CCL4 and rats given only CCL4. All parameters, however, were significantly lower ( P < 0.01) in the model controls. Conclusion: Terguride, a potent 5-HT2 antagonist, did not prevent the development of liver fibrosis in rats given CCL4.
Superheavy Elements – Chemistry and Spectroscopy
Authors: Kaldor Uzi
Published: August 2008

Superheavy elements, a somewhat loose term usually applied to elements with atomic number above 100, exhibit chemical and spectroscopic properties that are not necessarily extrapolations of lighter elements in the same group of the periodic table. This behavior is caused by relativity, which already affects heavy elements (e.g., changing transition energies in gold by as much as 4 eV), and is more important for the superheavy atoms. These elements are produced in accelerators in minute quantities and have short lifetimes, making experimental studies very difficult and costly. Chemical experiments involving the heavier elements are of the ‘one‐atom‐at‐a‐time’ type. Input from theory is crucial in guiding the experimentalist in the search for data.

The various theoretical and computational methods used to study these elements are described, and representative results given. For atoms, one can use highly accurate methods: starting from the four‐component Dirac–Coulomb–Breit Hamiltonian, correlation may be included by the most powerful tools of quantum chemistry. In particular, the relativistic Fock‐space coupled cluster (CC) approach reproduced numerous energy levels of heavy elements with an accuracy of a few hundredths of an eV, and provides therefore a reliable tool for predicting yet unknown levels of superheavy elements, as well as their ground state electron configurations. Molecules present a more difficult computational challenge, and more approximate methods, relying on effective core potentials or density functionals, are often used. Molecular properties such as volatility or adsorption energies, which are needed to guide experimentalists in tracing the compounds produced when atoms synthesized in the accelerator are reacted with various chemicals, are calculated, providing invaluable help in determining the existence and properties of the superheavy elements.
Amplitude and Velocity Measurement
Authors: Sydenham Peter H.
Published: August 2008

Use of seismic mass‐spring sensors for amplitude and velocity sensing is discussed to show where and when that type of sensor is applicable.
Characteristics of Time and Frequency Measurement
Authors: Lombardi Michael A.
Published: August 2008

The characteristics of time and frequency measurements are discussed. The discussion begins with an overview of the definitions and units used in time and frequency metrology. It continues by describing several measurement systems and techniques, and the types of oscillators used as time and frequency standards.
Calibrations and Standards in Time Measurement
Authors: Lombardi Michael A.
Published: August 2008

A discussion of time interval and time synchronization references is presented. The instrumentation and standards used to make these measurements are described, and sources of measurement uncertainty are discussed.
Voltage Measurement
Authors: Eren Halit
Published: August 2008

Signals generated by the sensors and transducers from physical variables are mostly in the voltage form. Examples are found in thermocouples, strain gauges, chemical sensors, electrochemical probes, biological sensors, and so on. Voltage magnitudes produced by these sensors are small requiring specialized signal conditioning circuits in the form of electrical bridges, amplifiers, filters, multiplexers, analog‐to‐digital converters, and so on. Once converted to digital forms, information about the physical variable can be stored or processed by computers. This article introduces the main methods used for voltage measurement.
Current Measurement
Authors: Eren Halit
Published: August 2008

Knowledge of the voltage located at the terminal of each circuit element as well as the current flowing in each element gives full information on the circuit behavior. The measurement of voltages and currents is hence of utmost importance to measuring systems. This article gives the basic theory and practice needed to understand how electric current is measured and standardized.
Resistance Measurement
Authors: Eren Halit
Published: August 2008

One of the most used electrical components in measuring systems is apparently the simple resistor. It is used extensively as the basis for many sensor types and as a means to interrogate sensors to produce measurable voltages and currents. This article concentrates on the various aspects of the measurement of resistance.
Capacitance and Inductance Measurement
Authors: Liguori Consolatina
Published: August 2008

Capacitance and inductance measurement techniques are intensively used in industrial and scientific applications. In fact, along with resistors, capacitors, and inductors, which are basically components with the propriety of capacitance and inductance respectively, are widely used in circuits for realizing a wide range of electrical and electronic apparatus and instruments. Consequently, the need for capacitance and inductance measurements arises in the characterization, design evaluation, and production test of relevant components and in the circuit modeling of electrical apparatus. Furthermore, these measurements are important since some physical quantities (e.g. humidity, displacement, pressure etc.) are transduced in capacitance or inductance.
Characteristics of Chemical Measurements
Authors: Sydenham Peter H.
Published: August 2008

Chemical measurements have several differences compared to measuring physical quantities. This article covers the main issues that need to be understood when designing or applying chemical analytical measurements. Later articles in this section on
Chemical Properties
provide basic understanding of the measurement fundamentals and application principles used in the commonly met analytical instruments.
Optical Transducers for Chemical Measurements
Authors: Sharma Ashutosh
Published: August 2008

Optical phenomena are widely exploited in the development of instruments that perform measurement on chemical species. Various optical chemical measurement instruments that use incident photon radiation as the primary tool include those based on intensity, UV–visible absorption, atomic absorption, derivate spectra, spectrophotometers, and infrared absorption.
Mass Spectrometry
Authors: Sydenham Peter H.
Published: August 2008

The mass spectrometer is a key instrument for measuring the molecular and elemental composition of samples. Basic principles are presented of how the mass of constituent parts is separated in a magnetic or electric field.
Chromatography
Authors: Paull Brett
Published: August 2008

Chromatography is a physical method of separation in which compounds are separated due to differences in their distribution between two phases, namely, a mobile phase and a stationary phase. In column chromatography, the stationary phase is immobilized within columns of various dimensions and the mobile phase, which can be either a gas or a liquid, carries the solute compounds through the stationary phase. The variety of instrumentation employed to carry out chromatographic separations are collectively termed
chromatographs
and all consist of a mobile phase delivery system, a sample/solute injection system, the chromatographic column itself, and a detector to monitor the separation over time and to record the separation in the form of a chromatogram.
Electrochemical Measurements
Authors: Davey David
Published: August 2008

Electrochemical measurements provide the basis for chemical analysis methods. Two key kinds of measurement are discussed here–potentiometry and voltammetry. Polarography is emphasized under voltammetry. Microarrays and biosensors are introduced.
Transducer Fundamentals
Authors: Regtien Paul P.L.
Published: August 2008

Transducers (sensors, actuators) are based on physical effects, allowing the conversion of energy (signals) from one domain to another. Most important for measurement instruments are input transducers (or sensors). Their function is the conversion of information about a particular (physical) quantity into an electrical quantity, with preservation of the information as a major issue. This section describes general properties of transducers, with emphasis on nomenclature, structure, physical basis, and performance specification.
Systematic Description of Sensors
Authors: Regtien Paul P.L.
Published: August 2008

There are an overwhelming number of sensors available, for almost every quantity that has to be measured, based on many different physical principles, in a wide variety of shapes and sizes, and for all kinds of applications and conditions. To find a way through this sensor jungle, a clear and systematic description of sensors would be very helpful. This article presents a description following a systematic approach. Such a systematic presentation may help designers and users of sensors to get a clear overview of the major sensor concepts, to obtain a better understanding of their basic operation and performance, and to facilitate sensor selection.
Classification of Sensors
Authors: McGhee Joseph
Published: August 2008

New ideas for sensors are constantly being invented—and reinvented. Classification and taxonomy of the many sensors has been developed using the principles of life sciences methods. A basis using energy relationships has been well developed. Application of the principles to the classification of temperature sensors is outlined as an example.
Force‐Feedback Sensors
Authors: Jones Barry E.
Published: August 2008

A feedback closed loop enables maintenance of a prescribed relationship of one variable to another variable in a sensory system. Using feedback it is possible to improve accuracy and speed of measurement, reduce the effects of interfering and modifying inputs, and allow remote indication and noncontact measurement. The property of inversion assists instrument design, and can provide for digital indication.
Materials in Measuring Systems
Authors: Sydenham Peter H.
Published: August 2008

Materials are vital to the manufacture of effective sensors and measuring instrument. Ceramics and plastics have made obvious inroads into sensor and instrument construction replacing traditional metals and natural materials. This article provides an introduction to the use of fine materials, their selection, and the kind of design problems that can arise.
Ultrasonic Sensors
Authors: Lesniewski Peter J.
Published: August 2008

The detailed description of piezoelectric sensor technology presented here includes tensor wave formulation and transduction relations, review of sensor material properties, technologies and measurement principles such as resonant, and delay time. Also provided is information on alternative sensing methods and the main shortcomings of typical sensors. Refer to
Ultrasonic Instrumentation Principles
and
Ultrasonic Instrumentation Design
for application detail.
Signals in the Presence of Noise
Authors: Burdett Richard
Published: August 2008

A measurement system begins with sensing stages that couple to relevant measurands of the system under study. The power level of the wanted information‐bearing signals formed by the sensors is often very low and may be swamped by the interfering noise signals that are present. Careful attention to sensor and circuit design and assembly, plus use of certain signal processing methods, makes it possible to greatly enhance the original signal‐to‐noise ratio to usable levels. This first article of the group on signal‐to‐noise improvement introduces the issues involved that are developed in later articles of this section.
Operational Amplifiers
Authors: McGhee Joseph
Published: August 2008

Signals usually need to be amplified to allow a range of operations to be carried out in a measuring system's signal processing system. This article introduces the basic operational amplifier form commonly used in instrumentation. It describes how feedback is used to improve the performance of the basic amplifier, gives models for the many variations and covers frequency response and error sources in operational amplifiers.
Outline of Purpose of Analog Data Filters
Authors: McGhee Joseph
Published: August 2008

Active analog data filters are outlined in this block, commencing with a description of the role of active signal filters. A description of the signal parameters to be selected and the interference effects to be filtered out is given. Active filter types are classified and their applications are briefly described. A comparison between active analog and digital filters is given. Active filter design methodology is described and some suppliers of universal active analog filter modules are given.
Z‐Transforms
Authors: Bousbaine Amar
Published: August 2008

The z‐transform plays a major role in engineering practice. It is used to study the system characteristics and the derivation of the computational structures for implementing discrete time systems on computers. The most important aspects of the z‐transform are presented, that is, characteristics of signals in terms of their pole‐zero diagram, ROC, causality and stability, and impulse response. More importantly, applications of the z‐transform in signal processing are discussed, which covers the computation of the frequency response, and the stability of the discrete time systems. Detailed applications of the z‐transform are covered in (
General Performance of the Digital Filter
;
Low‐, High‐, and Band‐pass Digital Filters
;
Finite Infinite Impulse Response (IIR) Digital Filters
; and
Finite Impulse Response (FIR) Digital Filters
).
DFT
and
FFTs
Authors: Wöstenkühler Gerd
Published: August 2008

Time signals can be analyzed in the time and frequency domain. To convert signals between these domains on a computer, the discrete Fourier transform (DFT) can be used. This article describes the principle of this conversion based on periodic signals. It also outlines the advantage and conditions of the fast Fourier transform (FFT), the effect of a limited time window and a weighting window for data acquisition and the improvements by using an averaging algorithm in the time and frequency domain.
DSP
Chip Sets
Authors: Paterson‐Stephens Iain
Published: August 2008

In order to make the transition from a theoretical design on paper to a real working application, which employs a mixture of hardware and software elements and algorithm designs, a number of further concepts need to be grasped. This article gives an overview of a range of fundamental signal processing functions and relates these to the associated hardware features found in a typical DSP system. A number of system approaches are presented including the use of general purpose ‘programmable’ DSP devices, Application Specific Integrated Circuits (ASICS) and the use of Gate Arrays.