Effect of arginine vasopressin on the canine epicardial coronary artery: experiments on V1-receptor-mediated production of nitric oxide

OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.

Endothelium-dependent relaxation in response to poly-L-arginine in canine coronary arteries: implications about hyperpolarization as a mechanism of vasodilatation

OBJECTIVE: To study the mechanism by which poly-L-arginine mediates endothelium-dependent relaxation. METHODS: Vascular segments with and without endothelium were suspended in organ chambers filled with control solution maintained at 37ºC and bubbled with 95% O2 / 5% CO2. Used drugs: indomethacin, acetycholine, EGTA, glybenclamide, ouabain, poly-L-arginine, methylene blue, N G-nitro-L-arginine, and verapamil and N G-monomethyl-L-arginine. Prostaglandin F2á and potassium chloride were used to contract the vascular rings. RESULTS: Poly-L-arginine (10-11 to 10-7 M) induced concentration-dependent relaxation in coronary artery segments with endothelium. The relaxation to poly-L-arginine was attenuated by ouabain, but was unaffected by glybenclamide. L-NOARG and oxyhemoglobin caused attenuation, but did not abolish this relaxation. Also, the relaxations was unaffected by methylene blue, verapamil, or the presence of a calcium-free bathing medium. The endothelium-dependent to poly-L-arginine relaxation was abolished only in vessels contracted with potassium chloride (40 mM) in the presence of L-NOARG and indomethacin. CONCLUSION: These experiments indicate that poly-L-arginine induces relaxation independent of nitric oxide.

El valor razonable como concepto vinculado a la pertinencia del valor. Fair value as a concept related to value relevance.

IDENTIFICACIÓN Y CARACTERIZACIÓN DEL PROBLEMA - HIPÓTESIS Según la NIC 39, el valor razonable es la cantidad por la que puede ser intercambiado un activo o cancelado un pasivo entre un comprador y un vendedor interesados y debidamente informados, en condiciones de independencia mutua. La definición del FASB (SFAC 7) es muy similar, y define el valor razonable como el monto mediante el que un activo podría ser enajenado en una transacción entre partes independientes, dispuestas a realizar la operación en situaciones diferentes a la de una liquidación o a la de una venta forzada. Puede apreciarse que esta definición de valor razonable es limitada porque, a excepción de escenarios que se correspondan con mercados perfectos y completos, el concepto puede abarcar valores de entrada, valores de salida y valores en uso, los cuales pueden ser muy diferentes (Beaver, 1987). El valor de entrada es el valor de adquisición o de reemplazo, el valor de salida es el precio al cual un activo puede ser vendido o liquidado, y el valor en uso es el valor incremental de una empresa atribuible a un activo (se correspondería con el valor presente mencionado anteriormente). Dado que el IASB y la FASB se ocupan de la valuación de activos que una empresa posee, y no de activos que serán adquiridos en un futuro, su definición de valor razonable debería ser interpretada desde la perspectiva del vendedor. Por lo tanto, el concepto de valor razonable que manejan el IASB y la FASB se asemeja a un valor de salida, tal como lo propusieron Chambers y Stirling hace bastantes años atrás.Planteado esto, lo que tratará de dilucidar este proyecto de investigación es si este concepto de valor razonable es realmente novedoso o es una simple regresión a los valores corrientes de salida defendidos por los autores de la década del setenta. OBJETIVOS GENERALES Y ESPECÍFICOS General Analizar si el concepto “valor razonable” tal como es definido por la normativa actual se corresponde con una definición novedosa o es una adaptación/modificación/regresión de conceptos ya existentes (valores corrientes de salida). Específicos Revisar la literatura específica desde el punto de vista de la teoría contable y las normas de las que dispone la profesión referidas a los siguientes aspectos: a) Valores corrientes b) Valor razonable MATERIALES Y MÉTODOS El análisis que se llevará a cabo comprenderá dos aspectos. El primero consiste en la revisión de la doctrina contable. Para ello se analizará bibliografía significativa y trabajos de eventos académicos relacionados con el valor razonable. En segundo término se revisará la normativa profesional a nivel nacional e internacional. Después de concluido con los pasos anteriores se analizará la novedad del concepto valor razonable y su semejanza con el valor corriente de salida planteado por los autores de la década del setenta. IMPORTANCIA DEL PROYECTO – IMPACTO Se pretende revisar si el concepto valor razonable planteado por la normativa actual resulta realmente novedoso o es una adaptación de viejos conceptos planteados en la década del setenta del siglo pasado. El proyecto resulta importante porque es un tema no desarrollado en la literatura, ni planteado en congresos. Se estima lograr material de publicación y presentación en eventos académicos. According to the NIC 39, fair value is the quantity for the one that can be exchanged an asset or cancelled a liability between a buyer and a seller interested and due informed, in conditions of mutual independence. The definition of the FASB (SFAC 7) is very similar, and defines fair value as the amount by means of which an assets might be alienated in a transaction between independent parts, ready to realize the operation in situations different from that of a liquidation or to that of a forced sale. This definition of reasonable value is limited because, with the exception of scenes that fit with perfect and complete markets, the concept can include values of entry, values of exit and values in use, which can be very different (Beaver, 1987). The value of entry is the value of acquisition or of replacement, the value of exit is the price to which an asset can be sold or liquidated, and the value in use is the incremental value of a company attributable to an asset. Provided that the IASB and the FASB deal with the appraisal of assets that a company possesses, and not of assets that will be acquired in a future, this definition of fair value should be interpreted from the perspective of the seller. Therefore, the concept of reasonable value that they handle the IASB and the FASB is alike a value of exit, as Chambers and Stirling proposed it enough years ago behind. We will review if the concept of "fair value" is really new or if it is an adaptation of old concepts.

The design and development of heat extraction technologies for the utilisation of compost thermal energy

A composting Heat Extraction Unit (HEU) was designed to utilise waste heat from decaying organic matter for a variety of heating application The aim was to construct an insulated small scale, sealed, organic matter filled container. In this vessel a process fluid within embedded pipes would absorb thermal energy from the hot compost and transport it to an external heat exchanger. Experiments were conducted on the constituent parts and the final design comprised of a 2046 litre container insulated with polyurethane foam and kingspan with two arrays of qualpex piping embedded in the compost to extract heat. The thermal energy was used in horticultural trials by heating polytunnels using a radiator system during a winter/spring period. The compost derived energy was compared with conventional and renewable energy in the form of an electric fan heater and solar panel. The compost derived energy was able to raise polytunnel temperatures to 2-3°C above the control, with the solar panel contributing no thermal energy during the winter trial and the electric heater the most efficient maintaining temperature at its preset temperature of 10°C. Plants that were cultivated as performance indicators showed no significant difference in growth rates between the heat sources. A follow on experiment conducted using special growing mats for distributing compost thermal energy directly under the plants (Radish, Cabbage, Spinach and Lettuce) displayed more successful growth patterns than those in the control. The compost HEU was also used for more traditional space heating and hot water heating applications. A test space was successfully heated over two trials with varying insulation levels. Maximum internal temperature increases of 7°C and 13°C were recorded for building U-values of 1.6 and 0.53 W/m2K respectively using the HEU. The HEU successfully heated a 60 litre hot water cylinder for 32 days with maximum water temperature increases of 36.5°C recorded. Total energy recovered from the 435 Kg of compost within the HEU during the polytunnel growth trial was 76 kWh which is 3 kWh/day for the 25 days when the HEU was activated. With a mean coefficient of performance level of 6.8 calculated for the HEU the technology is energy efficient. Therefore the compost HEU developed here could be a useful renewable energy technology particularly for small scale rural dwellers and growers with access to significant quantities of organic matter

Multimodality Imaging of Heart Valve Disease

Unidentified heart valve disease is associated with a significant morbidity and mortality. It has therefore become important to accurately identify, assess and monitor patients with this condition in order that appropriate and timely intervention can occur. Although echocardiography has emerged as the predominant imaging modality for this purpose, recent advances in cardiac magnetic resonance and cardiac computed tomography indicate that they may have an important contribution to make. The current review describes the assessment of regurgitant and stenotic heart valves by multimodality imaging (echocardiography, cardiac computed tomography and cardiac magnetic resonance) and discusses their relative strengths and weaknesses.

Focused Cardiac Ultrasound Using a Pocket-Size Device in the Emergency Room

Background:Cardiovascular urgencies are frequent reasons for seeking medical care. Prompt and accurate medical diagnosis is critical to reduce the morbidity and mortality of these conditions.Objective:To evaluate the use of a pocket-size echocardiography in addition to clinical history and physical exam in a tertiary medical emergency care.Methods:One hundred adult patients without known cardiac or lung diseases who sought emergency care with cardiac complaints were included. Patients with ischemic changes in the electrocardiography or fever were excluded. A focused echocardiography with GE Vscan equipment was performed after the initial evaluation in the emergency room. Cardiac chambers dimensions, left and right ventricular systolic function, intracardiac flows with color, pericardium, and aorta were evaluated.Results:The mean age was 61 ± 17 years old. The patient complaint was chest pain in 51 patients, dyspnea in 32 patients, arrhythmia to evaluate the left ventricular function in ten patients, hypotension/dizziness in five patients and edema in one patient. In 28 patients, the focused echocardiography allowed to confirm the initial diagnosis: 19 patients with heart failure, five with acute coronary syndrome, two with pulmonary embolism and two patients with cardiac tamponade. In 17 patients, the echocardiography changed the diagnosis: ten with suspicious of heart failure, two with pulmonary embolism suspicious, two with hypotension without cause, one suspicious of acute coronary syndrome, one of cardiac tamponade and one of aortic dissection.Conclusion:The focused echocardiography with pocket-size equipment in the emergency care may allow a prompt diagnosis and, consequently, an earlier initiation of the therapy.

Temperature, urbanization and body color polymorphism in South Brazilian populations of Drosophila kikkawai (Diptera, Drosophilidae)

Body color polymorphism of urban populations of cosmopolite fly Drosophila kikkawai Burla, 1954 was investigated in relation to its possible association with environmental temperature. Samples of D. kikkawai were collected in spring, summer, autumn and winter between 1987 to 1988, in zones with different levels of urbanization in the southern Brazilian city of Porto Alegre, Rio Grande do Sul. A clear association was observed between darker flies and both seasons with low temperatures and areas of low urbanization (where temperature is generally lower than in urbanized areas). Results of preliminary laboratory experiments involving six generations of flies grown in chambers at temperatures of 17º and 25ºC confirmed this tendency to a relationship between body color and temperature, with allele frequency of the main gene involved in body pigmentation changing over time.

Estructura del aparato reproductor masculino de Uca uruguayensis (Decapoda, Ocypodidae)

The structure of the male reproductive tract was described in Uca uruguayensis Nobili, 1901, by using histological methods, scanning electron microscopy techniques, and stereoscopic observations of fresh material. The aim of this work was to establish the functional changes associated with sexual maturation. The morphology of the first (G1) and second (G2) pair of gonopods was described. The male reproductive tract consists of paired organs: testes, and tubular and convoluted vas deferens (VD) ending with a terminal ampoule (TA).The (VD) is composed of three parts: anterior (AVD), medial (MVD) and posterior (PVD). The AVD and MVD are lined by a single layer of cubical cells. The PVD epithelial cells are columnar with elongated nuclei. The terminal ampoule comprises four interconnecting chambers and is externally surrounded by connective tissue. The study of testes and vas deferens at different times along the year suggests that U. uruguayensis has a single and continuous reproductive season from December to March. The TA has not been described in other brachyurans and this structure is novel to Brachyura.

Life history, biomass and production of Coronatella rectangula (Branchiopoda, Anomopoda, Chydoridae) from Minas Gerais

Species of Chydoridae provide the main diversity of the Cladocera. These organisms have been the subject of many studies; some dealing with their role in energy flow in aquatic ecosystems, since they inhabit the littoral region of water bodies which undergo the first impacts from anthropic activities. The aim of this study is to increase knowledge about the life cycle of Coronatella rectangula (Sars, 1861), a species found in several water bodies in the state of Minas Gerais, Brazil. The life cycle was determined by the culture of parthenogenetic females under controlled conditions in the laboratory. Experimental cultures were maintained in growth chambers at a constant temperature of 23.6(±0.5)ºC, through a 12 h light/12 h dark photoperiod. The organisms were fed on a suspension of Pseudokirchneriella subcapitata (Chlorophyceae) (10(5) cells.mL-1), and 0.02 mL of a mixed suspension of yeast and fish ration added per organism in equal proportions (1:1). Fifty parthenogenetic females with eggs were isolated and maintained until they produced neonates. Thirty of these neonates that had less than 24 hours were put in polypropylene bottles of 50 mL and kept in a germination chamber. These organisms were observed daily to obtain the parameters of the life cycle. Biomass and secondary production were also calculated. The embryonic development time of the specimens of C. rectangula was 1.68(±0.13) days and the time to reach primipara, was 2.48(±0.45) days. The mean fecundity of C. rectangula was two eggs/female/brood and the total number of eggs produced by the female during its life cycle was 27.8 eggs. During the whole life cycle, specimens of C. rectangula had a maximum of 14 seedlings, with two instars in the juvenile stage. Total biomass for C. rectangula was 36.66 µgDW.m-3(9.83 for the juvenile stage and 26.82 µgDW.m-3 for adults), and secondary production was 12.10 µgDW.m-3.day-1(8.34 µgDW.m-3.day-1 for egg production and 3.76 µgDW.m-3.day-1 for the juvenile stage).

Lymnaea Diaphana; a study of Topotypic specimens (Pulmonata: Lymnaeidae)

A description of the species Lymnaea diaphana King, 1830 is presented, on the basis of material collected at its type-locality, San Gregorio, on the north coast of the Strait of Magellan, in the Chilean province of Magallanes. It may be identified by the following characters taken together: adult shell over 10 mm in length, whorls inflated, regularly convex, separated by a well-marked suture, aperture ovate occupying about half the shell length; renal organ forming an approximately right angle with the ureter; pouch of the oviduct well noticeable high on the right ventral surface and on the right side of the nidamental gland; uterus bent to the right into an approximately right angle; body of the spermatheca projected into the pulmonary cavity and adhered to the pericardium and to the roof of the pulmonary cavity; spermiduct highly sinuous, folding dorsalward between the left half of the oviduct and the left shoulder of the nidamental gland, and then winding on ventralward to reach the prostate on the middle line; prostate voluminous, convex on the left, pushed in on the right, with a deep dorsal furrow corresponding to a fold which projects into the prostatic lumen and is more developed at the fore half of the organ; apical end of the penial sheath with about six minute protuberances corresponding to inner chambers; prepuce from about as long about twice as long as the penial sheath, with some variation beyond those limits; lateral teeth of the radula basically tricuspid, with a usually simple ectocone which may show a bifid or trifid point. A diagnosis between lymnaea diaphana and three other lymnaeids which also occur in South America and were previously studied by the author - L. columella, L. viatrix and L. rupestris - is presented.

The influence of building materials on the residual action of BHC

Residual insecticide activity of BHC vapors from various building materials in controlled humidity chambers in the laboratory were significantly different. Laboratory-reared, first instar nymphs of Dipetalogaster maximus were exposed to vapors of BHC which were being released from the treated surfaces of building materials taken from Mambaí, Goiás.

Desensitization of thermal hyperemia in the skin is reproducible.

OBJECTIVE: Local heating increases skin blood flow SkBF (thermal hyperemia). In a previous study, we reported that a first local thermal stimulus could attenuate the hyperemic response to a second one applied later on the same skin spot, a phenomenon that we termed desensitization. However, other studies found no evidence for desensitization in similar conditions. The aim of the present work was to test whether it was related to differences in instrumentation. METHODS: Twenty-eight healthy young males were studied. Two pairs of heating chambers, one custom-made (our study) and one commercial (other groups), were affixed to forearm skin. SkBF was measured with single-point laser-Doppler flowmetry (LDF) (780nm) in one pair, and laser-Doppler imaging (LDI) (633nm) in the other. A temperature step from 34 to 41°C, was applied for 30minutes and repeated after two hours. RESULTS: During the second thermal challenge, the plateau SkBF was lower than during the first thermal and was observed with each of the four combinations of SkBF measurement techniques and heating equipment (p<0.05 for all conditions, range -9% to -16% of the initial value). CONCLUSION: Desensitization of thermal hyperemia is not specific to peculiar operating conditions.

Oxygen isotope thermometry in carbonatites, Fuerteventura, Canary Islands, Spain

Crystallization temperatures of the oceanic carbonatites of Fuerteventura, Canary Islands, have been determined from oxygen isotope fractionations between calcite, silicate minerals (feldspar, pyroxene, biotite, and zircon) and magnetite. The measured fractionations have been interpreted in the light of late stage interactions with meteoric and/or magmatic water. Cathodoluminescence characteristics were investigated for the carbonatite minerals in order to determine the extent of alteration and to select unaltered samples. Oxygen isotope fractionations of minerals of unaltered samples yield crystallization temperatures between 450 and 960degreesC (average 710degreesC). The highest temperature is obtained from pyroxene-calcite pairs. The above range is in agreement with other carbonatite thermometric Studies. This is the first study that provides oxygen isotope data coupled with a CL study on carbonatite-related zircon. The CL pictures revealed that the zircon is broken and altered in the carbonatites and in associated syenites. Regarding geological field evidences of syenite-carbonatite relationship and the close agreement of published zircon U/Pb and whole rock and biotite K/Ar and Ar-Ar age data, the most probable process is early zircon crystallization from the syenite magma and late-stage reworking during magma evolution and carbonatite segregation. The oxygen isotope fractionations between zircon and other carbonatite minerals (calcite and pyroxene) support the assumption that the zircon would correspond to the early crystallization of syenite-carbonatite magmas.

The tectonically controlled emplacement of a vertically sheeted gabbro-pyroxenite intrusion: Feeder-zone of an ocean-island volcano (Fuerteventura, Canary Islands)

The Miocene PX1 gabbro-pyroxenite pluton, Fuerteventura, Canary Islands, is a 3.5 x 5.5 km shallow-level intrusion (0.15-0.2 GPa and 1100-1120 degrees C), interpreted as the feeder-zone to an ocean-island volcano. It displays a vertical magmatic banding expressed in five 50 to 100 metre-wide NNE-SSW trending alkaline gabbro sequences alternating with pyroxenites. This emplacement geometry was controlled by brittle to ductile shear zones, generated by a regional E-W extensional tectonic setting that affected Fuerteventura during the Miocene. At a smaller scale, the PX1 gabbro and pyroxenite bands consist of metre-thick differentiation units, which suggest emplacement by periodic injection of magma pulses as vertical dykes that amalgamated, similarly to a sub-volcanic sheeted dyke complex. Individual dykes underwent internal differentiation following a solidification front parallel to the dyke edges. This solidification front may have been favoured by a significant lateral/horizontal thermal gradient, expressed by the vertical banding in the gabbros, the fractionation asymmetry within individual dykes and the migmatisation of the wall rocks. Pyroxenitic layers result from the fractionation and accumulation of clinopyroxene +/- olivine +/- plagioclase crystals from a mildly alkaline basaltic liquid. They are interpreted as truncated differentiation sequences, from which residual melts were extracted at various stages of their chemical evolution by subsequent dyke intrusions, either next to or within the crystallising unit. Compaction and squeezing of the crystal mush is ascribed to the incoming and inflating magma pulses. The expelled interstitial liquid was likely collected and erupted along with the magma flowing through the newly injected dykes. Clinopyroxene mineral orientation - as evidenced by EBSD and micro X-ray tomography investigations - displays a marked pure-shear component, supporting the interpretation of the role of compaction in the generation of the pyroxenites. Conversely, gabbro sequences underwent minor melt extraction and are believed to represent crystallised coalesced magma batches emplaced at lower rates at the end of eruptive cycles. Clinopyroxene orientations in gabbros record a simple shear component suggesting syn-magmatic deformation parallel to observed NNE-SSW trending shear zones induced by the regional tensional stress field. This emplacement model implies a crystallisation time of 1 to 5 years for individual dykes, consistent with PX1 emplacement over less than 0.5 My. A minimum amount of approximately 150 km(3) of magma is needed to generate the pluton, part of it having been erupted through the Central Volcanic Centre of Fuerteventura. If the regional extensional tectonic regime controls the PX1 feeder-zone initiation and overall geometry, rates and volumes of magma depend on other, source-related factors. High injection rates are likely to induce intrusion growth rates larger than could be accommodated by the regional extension. In this case, dyke intrusion by propagation of a weak tip, combined with the inability of magma to circulate through previously emplaced and crystallised dykes could result in an increase of non-lithostatic pressure on previously emplaced mushy dyke walls; thus generating strong pure-shear compaction within the pluton feeder-zone and interstitial melt expulsion. These compaction-dominated processes are recorded by the cumulitic pyroxenite bands. (C) 2010 Elsevier B.V. All rights reserved.