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Background: Despite many epidemiological reports concerning the efficacy of angiotensin-converting enzyme (ACE) inhibitors in dogs with mitral regurgitation (MR), the hemodynamic effects of ACE inhibitor administration have not been fully evaluated. Objectives: To document left atrial pressure (LAP) in dogs with MR administered ACE inhibitors, in order to obtain interesting information about daily LAP changes with administration of ACE inhibitors. Animals: Five healthy Beagle dogs weighing 9.8 to 14.2 kg (2 males and 3 females; aged 2 years). Methods: Experimental, crossover, and interventional study. Chordae tendineae rupture was induced, and a radiotelemetry transmitter catheter was inserted into the left atrium. LAP was recorded for 72 consecutive hours during which each of 3 ACE inhibitors—enalapril (0.5 mg/kg/d), temocapril (0.1 mg/kg/d), and alacepril (3.0 mg/kg/d)—were administered in a crossover study. Results: Averaged diurnal LAP was significantly, but slightly reduced by alacepril (P= .03, 19.03 ± 3.01–18.24 ± 3.07 mmHg). The nightly drops in LAP caused by alacepril and enalapril were significantly higher than the daily drops (P= .03, −0.98 ± 0.19 to −0.07 ± 0.25 mmHg, and P= .03, −0.54 ± 0.21–0.02 ± 0.17 mmHg, respectively), despite the fact that the oral administrations were given in the morning. Systolic blood pressure (122.7 ± 14.4–117.4 ± 13.1 mmHg, P= .04) and systemic vascular resistance (5800 ± 2685–5144 ± 2077 dyne × s/cm5, P= .03) were decreased by ACE inhibitors. Conclusions and Clinical Importance: ACE inhibitors decrease LAP minimally, despite reductions in left ventricular afterload. ACE inhibitors should not be used to decrease LAP.

A Lower Tunnel Among the peculiarities inherent in quantum mechanics is the ability of particles to tunnel through barriers that they lack the energy to surmount classically, as happens during radioactive decay. Strong laser fields can liberate electrons in this way from atoms and molecules. Akagi et al. (p. 1364 ) elegantly confirm that tunneling is not limited to the highest-energy electrons in a system by mapping the energy and momentum of both the ejected electron and positive ion produced when an intense laser pulse impinges on hydrogen chloride. When the molecule adopts specific orientations relative to the laser field, tunneling occurs from lower-lying states, as well as the highest-energy occupied orbital. This raises the possibility of tunneling microscopy capable of imaging the electronic structure of single molecules.

We are all influenced by Nicolai Delone’s research. Through much of his career, his influence reached Canada through his published papers. However, Professor Delone visited the National Research Council of Canada’s laboratories at least three times from about 1989 to 1995. At that time he was primarily interested in stabilization. Stabilization refers to the fact that, as the intensity of laser light illuminating an atom is increased, the ionization rate passes through a maximum, then falls. Surprisingly the atom becomes stable against ionization at very high intensities.

The concentration of mercury in fish samples from the Atlantic coast of Ghana was determined using a simple, rapid and accurate method. A mixture of HNO3, HClO4 and H2SO4 was used for complete oxidation of organic tissue. Mercury is detected by the cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer developed at the National Institute for Minamata Disease (NIMD). In total, 56 samples covering 13 species of fish were analysed for total mercury. The concentration of mercury in the edible muscle tissue of these fish ranged from 0.004 to 0.122 μg g−1 wet weight. All fish species sampled had concentrations less than the WHO limit of 0.5 μg g−1 wet weight. The low concentrations of mercury detected in the samples do not constitute any significant mercury exposure to the general population through fish consumption.

Miniature inverted-repeat transposable elements (MITEs) represent a large superfamily of transposons that are moderately to highly repetitive and frequently found near or within plant genes. To elucidate the organization of MITEs in the barley genome, MITEs were integrated into the genetic map of barley. In this report, we describe the use of MITEs in amplified fragment length polymorphism (AFLP) mapping, and demonstrate their superiority over conventional AFLP mapping. Barley MITEs include members of the Stowaway, Barfly, and Pangrangja families. By amplifying the flanking sequences of these MITEs, a total of 214 loci were mapped from a population of 93 doubled-haploid segregating individuals between Hordeum vulgare ssp. vulgare and H. vulgare ssp. spontaneum. The 214 MITE-AFLP and 40 anchor simple sequence repeat (SSR) loci were distributed on 7 linkage groups, covering a total map distance of 1 165 cM. The average marker density on each chromosome ranged between 3.4 and 9.6 cM per locus. Only 1 MITE-based locus was frequently found to be associated with MITE loci from the same family, resulting in clusters in chromosomal subregions. In barley, it will be possible to cover the entire genome with a limited set of MITE-based primers and to build highly dense maps of specific regions.

Silicon isotope separation has been performed utilizing the infrared multiphoton dissociation (IRMPD) of Si2F6 irradiated with two-frequency CO2 laser lights. The two-frequency excitation method improved the separation efficiency by keeping the high enrichment factors. For example, Si2F6 with the 28Si fraction of 99.4% was obtained at 40.0% dissociation of Si2F6 after the simultaneous irradiation of 100 pulses with 966.23 cm-1 photons (0.089 J/cm2) and 954.55 cm-1 photons (0.92 J/cm2), while 1000 pulses were needed to obtain 99.0% of 28Si at 27.2% dissociation in the case of single frequency irradiation at 954.55 cm-1 (0.92 J/cm2). The single-step enrichment factors of 29Si and 30Si increased with increasing Si2F6 pressure. The reason for this enhancement has been discussed in terms of the rotational and vibrational relaxations by collisions with ambient gases.

Mercury exists in various forms including metallic mercury, inorganic and organic mercury compounds. Research studies show that contamination brought about by natural and man-made activities is clearly a growing problem today. In 1956, the first recognized poisoning outbreaks occurred. Minamata Disease is a disorder of the central nervous system caused by the consumption of fish and shellfish contaminated with methylmercury. Clinical manifestation differs from inorganic mercury poisoning in which the kidneys and the renal system are damaged. The toxidrome consists of sensory disorders in the distal portion of the four extremities, cerebral ataxia, bilateral concentric constriction of the visual field, central disorder of ocular movement, central hearing impairment and disequilibrium. Fetal type Minamata Disease bom of mothers being exposed to methylmercury during pregnancy resulted in conditions similar to those associated with infantile cerebral palsywere also documented. Measures to control environmental pollution were implemented such as the environmental restoration project, compensation and relief of victims as part of the health and environmental management undertaken by the government. At present, global research studies are focusing on long-term and low-dose inorganic and methyl mercury exposure; and developmental neurobehavioral toxicity including relevant environmental factors influencing mercury transformations, mass balances and partitioning in ecosystems.

Total mercury (THg) and methylmercury (MeHg) levels have been determined in fish species representing various tropic levels in four major hydroelectric reservoirs (Mtera, Kidatu, Hale-Pangani, Nyumba ya Mungu) located in two distinct geographical areas in Tanzania. The Mtera and Kidatu reservoirs are located along the Great Ruaha River drainage basin in the southern central part of the country while the other reservoirs are located within the Pangani River basin in the north eastern part of Tanzania. Fish mercury levels ranged from 5 to 143 microg/kg (mean 40 microg/kg wet weight) in the Mtera Reservoir, and from 7 to 119 microg/kg (mean 21 microg/kg) in the Kidatu Reservoir downstream of the Great Ruaha River. The lowest THg levels, in the range 1-10 microg/kg (mean 5 microg/kg), were found in fish from the Nyumba ya Mungu (NyM) Reservoir, which is one of the oldest reservoirs in the country. Fish mercury levels in the Pangani and Hale mini-reservoirs, downstream of the NyM Reservoir, were in the order of 3-263 microg/kg, with an average level of 21 microg/kg. These THg levels are among the lowest to be reported in freshwater fish from hydroelectric reservoirs. Approximately 56-100% of the total mercury in the fish was methylmercury. Herbivorous fish species contained lower THg levels than the piscivorous species; this was consistent with similar findings in other fish studies. In general the fish from the Tanzanian reservoirs contained very low mercury concentrations, and differed markedly from fish in hydroelectric reservoirs of similar age in temperate and other regions, which are reported to contain elevated mercury concentrations. The low levels of mercury in the fish correlated with low background concentrations of THg in sediment and flooded soil (mean 2-8 microg/kg dry weight) in the reservoir surroundings. This suggested a relatively clean reservoir environment that has not been significantly impacted by mercury contamination from natural or anthropogenic sources.

In evaluating the giga-cycle fatigue strength of some high strength steels, information on the size distribution of nonmetallic inclusions contained in the material is indispensable. To save time and effort of obtaining such data concerning the inclusions, a convenient dissolution method to evaluate the maximum inclusion size is proposed, in place of a conventional method of measuring the inclusion sizes on many cross-sectional areas. Meanwhile, to save time-consuming work of obtaining giga-cycle fatigue properties of some metallic materials, an intermittent ultrasonic fatigue testing method has also been developed. In the present paper, these two newly developed methods were successfully combined to assess the long life fatigue properties of maraging steels as a function of inclusion size.

Concentration levels of mercury and its organic compounds in natural water samples are very low, so accurate analysis is still a major problem. To ensure the validity of such measurements a proper quality control/quality assurance programme should be implemented. In the absence of reference materials, the best way to check the accuracy of the results is through interlaboratory comparisons and comparisons of the results obtained by different analytical methods. The purpose of the present work was to compare independent analytical techniques used by two different laboratories for determination of total mercury (Hg-T) and monomethylmercury compounds (MeHg) in seawater samples from Minamata Bay, Japan. The interlaboratory study was carried out between the Jožef Stefan Institute, Ljubljana, Slovenia and the National Institute for Minamata Disease, Minamata, Japan. Copyright © 2001 John Wiley & Sons, Ltd.

The toxicological consequences of Hg releases to the environment are largely governed by the conversion ofinorganic Hg to the most toxic methylmercury (MeHg), that is biomagnified through aquatic food chains. To gain further insight on the biological and physico-chemical factors controlling MeHg production and distribution among freshwater sediments and water, we used a sensitive and specific radiochemical procedure, developed at the National Institute for Minamata Disease. Systems containing 203Hg2+-spiked sediment cores (0.7 μg total Hg g-1 d.w.) and overlying water, both from a pristine mountain stream in Southern Japan, were incubated for 21–38 days in different conditions. Inorganic Hg and MeHg in sediment and water were extracted in dithizone-benzene and measured after separation by thin-layer chromatography. The conversion of added Hg to MeHg was 3.0 to 13.7% in sediments, with a tendency for higher proportions in the top layers. Surprisingly, more MeHg was found in the sediment (11.3%) and water (66.5%) of a system bubbled with air than in one bubbled with nitrogen (4.2 and 44.1%). Artificially increased levels ofbioturbation reduced by half the MeHg concentrationsand % of added total Hg in sediment and water. In allsystems, 55–68% of total Hg and MeHg in water wereassociated to suspended particles >1μm. MeHgbioaccumulation factors (BFs) from water ranged270–8100 and from sediment, 0.2–5.7 (wet weight basis). BFs in relation to water where 3 times higher for MeHg than for total Hg.

Mercury methylation and partitioning between sediment, water and fish were studied in river sediment spiked with mercuric chloride at levels of 1, 5 and 10 ppm as Hg. Maximum methylmercury production in the sediment occurred during the first week of incubation, with concentrations reaching 45.5 ng/g (dry wt.). Equilibrium conditions were established 3-4 weeks after the contamination of the sediment with mercury. Methylmercury partitioning between sediment and water yielded methylmercury levels of 25-154 ng/l in the fish aquariums and 0.26 ng/l in the fish-free control after 1 week of incubation. Equilibrium levels were 1.5-5.5 ng/l and 0.53 ng/l, respectively, during the 7th week. Over 50% of the methylmercury in whole water were in soluble form or associated with colloidal particulate1 micron. Mercury concentration in fish increased almost exponentially from 30 ppb to an average of 345 ppb within 3 weeks. Mercury uptake rates by fish were in the range of 10-18 ng/g per day during the 2nd and 3rd weeks, high rates occurring in water with methylmercury to total mercury ratios0.45. The partition coefficients for total mercury and methylmercury between fish and water (Kf-w) were 5000-7000 and 10,000-22,000, respectively. Large differences were observed in methylmercury production in sediment-water incubation with fish and the fish-free control. Equilibrium methylmercury concentrations in sediment were in the range 15-32 ng/g in the aquariums containing fish and 3-4.5 ng/g in the fish-free control. The significance of fish in mercury methylation in the aquariums still remains to be clarified as fish itself cannot methylate mercury in vivo.

It has previously been confirmed that the guinea pig has aggregations of 10-20 lymphoid follicles at the junction of the nasal cavity and the nasopharyngeal duct. The vascular architecture of this nasal-associated lymphoid tissue (NALT) was studied by the corrosion cast/scanning electron microscope method. The NALT was supplied by branches of the inferior nasal artery. These afferent arterial branches gave off arterioles to the follicles and the interfollicular regions, where the arterioles ramified into capillaries. Some of these arterioles reached the subepithelial region to form a single-layer dense capillary network. The subepithelial capillaries gathered into short collecting venules, which in turn drained into high endothelial venules (HEV) in the interfollicular region. The HEV, which also receives tributaries from the follicular and interfollicular capillary plexuses, descended in the interfollicular regions and finally flowed into the efferent veins at the bottom of the NALT. Indentations impressed by high endothelial cells (HEC) were prominent on the surface of the HEV casts, and their frequency was larger in the upper course or segments than in the lower. This suggests that the incidence of HEC in the upper segments is higher than in the lower segments, and these findings are consistent with the hypothesis that some substances which are taken up into the subepithelial capillaries and transported to the venules induce differentiation and maintain of HEVs.

We propose a new approach to obtain molecular frame photoelectron angular distributions from molecules ionized by intense laser pulses. With our method we study the angular tunnel ionization probability of H2 at a wavelength of 800 nm over an intensity range of 2-4.5 x 10(14) W/cm2. We find an anisotropy that is stronger than predicted by any existing model. To explain the observed anisotropy and its strong intensity dependence we develop an analytical model in the framework of the strong-field approximation. It expresses molecular ionization as a product of atomic ionization rate and a Fourier transform of the highest occupied molecular orbital filtered by the strong-field ionization process.

Mature rat spinal cord cDNA libraries constructed in λgt10 and λZAPII were screened with an oligonucleotide probe (39 mer), and 4 clones that possess DNA-inserts encoding a glycine receptor subunit were obtained. The cloned cDNAs were used to reconstruct the nucleotide sequence of the full-length open reading frame consisting of 1350 base pairs (bp) as well as the 5′-(184 bp) and 3′-(591 bp) non-coding regions. Synthetic RNA transcribed in vitro from the glycine receptor cDNA induced Xenopus oocytes to synthesize functional glycine receptor that generated large Cl − currents. The electrophysiological properties of the wild-type receptor and some mutant receptors produced by site-directed mutagenesis were analyzed.

In den bisherigen Kapiteln wurden Stromrichterschaltungen vorwiegend aus der Sicht der Antriebstechnik dargestellt, die entweder die Energieumformung von einem Wechsel- bzw. Drehstromsystem zu einem Gleichstromsystem bzw. umgekehrt oder von einem Gleichstromsystem zu einem anderen Gleichstromsystem ermoglichen.

We have developed a prototype of the real time AV transmission system for high quality MPEG2-TS stream over IP-based home network. By using the prototype, we have proved the effectiveness of basic framework of DTCP-IP and our newly developed small delay and precise de-jittering technology for high quality streaming.

Object movement detection by high order correlation analysis of optical sensor array signals is introduced. The optical sensors observe the moving object surface which is assumed to be a non-uniform speckle-like texture. The measurement system is applicable to general robotic movement detection because: it employs a noncontact measurement method, the system can be made very compact, and it enables approximation of the movement trace with a sequence of arcs instead of the conventional connection of simple line segments. The authors looked into estimation of the running trace of an autonomous vehicle by observing the ground pattern. >

This paper deals with "unified power quality conditioners" (UPQCs) which aim to integrate series active and shunt active filters. The main purpose of a UPQC is to compensate for voltage flicker/imbalance, reactive power, negative sequence current and harmonics. In other words, the UPQC has the capability of improving power quality at the point of installation on power distribution systems or industrial power systems. This paper discusses the control strategy of the UPQC, with the focus on the flow of instantaneous active and reactive power inside the UPQC. Some interesting experimental results obtained from a laboratory model of 20 kVA, along with theoretical analyses, are shown to verify the viability and effectiveness of the UPQC.

We evaluated a series of novel cephem antibiotics, N-alkylpyridinium (alkyl group), N-carboxyethylpyridinium (carboxylic group), N-sulfoethylpyridinium (sulfonic group) and N-alkylquaternary ammonium salts (ammonioethyl group), N-alkyl-aromatic-quaternary ammonium salts and N-alkyl-heterocyclic quaternary ammonium salts (cyclic group) as vinylthio pyridinium derivatives at the C-3 position and hydroxyiminoaminothiazol at the C-7 position, for their activity against methicillin-resistant Staphylococcus aureus (MRSA) and their solubility, by measuring the minimum inhibitory concentrations (MICs) and the dissolving test in phosphate buffer. All tested compounds, except for the alkyl group, showed good solubility (10%) in 1/15 M phosphate buffer (pH 7.2). The concentrations required to inhibit 80% of the bacterial strains (MIC80s) of the alkyl group, carboxylic group, sulfonic group, ammonioethyl group and cyclic group against MRSA were 1.56, 12.5-25, 6.25, 1.56 and 1.56 microg/ml, respectively. These results indicated that the ammonioethyl and cyclic groups yield the maximum anti-MRSA and anti-Enterococcus faecalis activity, and also good water solubility.

The methylmercury content in two new marine bivalve mollusk tissue Standard Reference Materials (SRMs) has been certified using results of analyses from the National Institute of Standards and Technology (NIST) and two other laboratories. The certified concentrations of methylmercury were established based on the results from four and six different (independent) analytical methods, respectively, for SRM 1566b Oyster Tissue (13.2 +/- 0.7 microg/kg) and SRM 2977 Mussel Tissue (organic contaminants and trace elements) (36.2 +/- 1.7 microg/kg). The certified concentration of methylmercury in SRM 1566b is among the lowest in any certified reference material (CRM).

Rice is one of the most important crops in the world, and feeds about 40% of the world population. The yield of rice needs to be increased, since a world food crisis has been predicted for the early 21st century. World annual rice production must increase from its current value of 520 to 810 million tons by 2025 (Hossain 1996). Since rice shows heterosis to give a higher yield, hybrid rice may offer a solution to this predicted food crisis. The yield of hybrid rice is about 15% higher than that of conventional pure line varieties (Yuan 1994). In 1991, hybrid rice covered 17.6 million ha, 55% of the total area of rice in China (Yuan 1994).

The vibrational state distribution and the stereodynamics of product NO in the highly exothermic O(

Probenazole (3-allyloxy-1,2-benzisothiazole-1,1-dioxide) is an agricultural chemical primarily used to prevent rice blast disease. Probenazole-treated rice acquires resistance to blast fungus irrespective of the rice variety. The chemical is applied prophylactically, and is thought to induce or bolster endogenous plant defenses. However, the mechanisms underlying this effect have not been established. To understand the mode of the chemical's action, we screened for novel probenazole-responsive genes in rice by means of differential display and identified a candidate gene, RPR1. RPR1 contains a nucleotide binding site and leucine-rich repeats, thus sharing structural similarity with known disease resistance genes. The expression of RPR1 in rice can be up-regulated by treatment with chemical inducers of systemic acquired resistance (SAR) and by inoculation with pathogens. RPR1-related sequences in rice varieties seem to be varied in sequence and/or expression, indicating that RPR1 itself is not a crucial factor for induced resistance in rice. However, Southern blot analysis revealed the existence of homologous sequences in all varieties examined. While the role of RPR1 has yet to be clarified, this is the first report of the identification of a member of this gene class and its induction during the systemic expression of induced disease resistance.

Japan has a long history of mercury contamination, the most tragic example being the organic mercury poisoning of Minamata Bay, and the subsequent outbreak of Minamata disease, which killed so many people. Today in Japan there are many cases of mercury contamination of soils in the vicinity of agricultural and industrial chemical plants etc. In other parts of the world, mercury contamination problems, such as those caused by the smelting of gold in the Amazon basin and other tropical regions, have become a worldwide concern.

The omega-3 fatty acid desaturases are membrane-bound enzymes catalyzing the conversion of linoleic acid to linolenic acid in lipids, and are located both in the microsome and plastid envelopes as two different isoforms. A cDNA encoding the microsome omega-3 fatty acid desaturase (OsFAD3) and the corresponding genomic clone were isolated from rice (Oryza sativa L.). The OsFAD3 gene was composed of 8 exons and 7 introns. A microsatellite was present in the second exon of the OsFAD3 gene, showing polymorphism between Indica and Japonica rice varieties. The mapping of this microsatellite showed that the OsFAD3 gene was located on chromosome 11. Expression of the OsFAD3 cDNA in tobacco hairy root tissues and subsequent analysis of fatty acid compositions demonstrated the activity of the microsome omega-3 fatty acid desaturase. The OsFAD3 mRNA was abundant in root tissues, but was hardly detectable in leaves. In root tissues, a high level of the OsFAD3 mRNA was observed at 15 degrees C and 20 degrees C, with its level decreasing markedly at temperatures below 10 degrees C. The accumulation of the OsFAD3 mRNA in leaf tissues remained at quite low levels, both at normal growth temperatures and at chilling temperatures. Similar temperature responses of the OsFAD3 gene were observed both in chilling- tolerant and in chilling-intolerant rice cultivars.

Monitoring of environmental and human exposure to mercury in the Nungwe Bay area of the Lake Victoria goldfields. Tanzania, has revealed low mercury concentrations in fish (range: 1.8–16.9 ppb, mean: 7.0 ppb) and human hair (range: 156–5433 ppb, mean: 947 ppb) that represent background levels. Gold mining has not produced a significant increase in environmental methylmercury that is available for bioaccummulation in aquatic food chains. Urinary mercury levels in gold mine workers frequently exposed to Hg vapour in amalgamation and burning of amalgam were significantly higher (mean: 241 ng/ml) than those in the general mine population not occupational exposed to Hg (mean: 2.6 ng/ml). Rotation of mine duties reduced Hg exposure levels and hence the risk of intoxication in the gold mine workers. The lowest urinary and hair mercury levels were found in the Nungwe Bay fishing village population. This was consistent with the low mercury content of fish consumed by the inhabitants of the Nungwe Bay.

This report will provide a summary of the discussions and conclusions of the Ocean Working Group concerning the current knowledge of mercury in the ocean and its fate and transport between the oceanic reservoir and other compartments. Because of the generality of the discussions, the report will not refer to individual publications directly; rather a comprehensive list of recent relevant publications is appended at the end of the report.