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Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO3, in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos.

Subtle sexual dimorphism and its perception in apparently monomorphic bird species warrant assessment of how birds identify the sex of conspecifics, particularly of prospective mates. Visual sensitivity and its potential co-variation with cryptic sexual dichromatism are still uninvestigated in most avian taxa. Using molecular sexing, reflectance spectrometry and perceptual modelling based on the sequencing of short wavelength visual pigments, we assessed the sex-specificity of coloration and colour perception in the red-tailed tropicbird Phaethon rubricauda. We also measured morphological dimorphism at a previously unstudied breeding locality for this species. Our data are in line with both physical and avian-perceived monochromatism with a potential indication of achromatic sex differences in plumage reflectance. The moderate extent of size dimorphism is consistent with reports from other Pacific breeding populations, and morphological measurements from live specimens in this study are in line with reports on museum specimens from the same sample location. Potential differences between individuals of the same sex in size and coloration warrant the assessment of sexual dimorphism in larger sample sizes of this species.

Effective blood pressure control with a large arsenal of conventional antihypertensive drugs, such as diuretics, beta-adrenergic blockers, and calcium channel blockers, significantly reduce the morbidity and mortality associated with cardiovascular disease. However, blood pressure control with these drugs does not reduce cardiovascular disease risks to the levels in normotensive persons. Only two drug classes that inhibit or antagonize portions of the renin-angiotensin system (RAS), angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor type-1 (AT1 receptor) blockers, have protective and beneficial effects unrelated to the degree of blood pressure reduction. These drugs may prevent the blood pressure related functional and structural abnormalities of the cardiovascular system and reduce the end organdamage. The first part of this review presents the components of the RAS, biological actions of angiotensin peptides, and the functions of the enzymes that generate and metabolize angiotensins, including the likely effect of manipulating them. Special attention is devoted to renin, ACE, ACE2, chymase, and neprilysin. The second part of this review presents the rationale for targeting the RAS, based on clinical studies of the ACE inhibitors and AT1 receptor blockers. Finally, we present the investigational agents acting on the RAS that have a potential for clinical usage, and give the perspective of pharmacological, immunological and gene targeting of the RAS for treatment of cardiovascular disease.

AbstractThe content and chemical composition of Mentha aquaticaL. (Lamiaceae) essential oil during three phenophases (before flowering, flowering and after flowering) was compared. Quantities of the essential oils were determined according to the European Pharmacopoeia 4ed 12and chemical profiles by GC-MS. The highest content of the essential oil was found before flowering stage (0.73%). The main constituent of the essential oil through all the three phenophases was menthofuran (19.0–24.5%), followed by 1,8-cineole (11.8–20.2%), E-caryophyllene (6.7–16.6%) and viridiflorol (7.6–9.0%). Although the composition of the essential oil in all the three investigated phenophases was generaly similar, some qualitative differences were observed (presence of α-guaiene, γ-murolene, valencene and germacrene B only before flowering, linalool and pulegone in the flowering stage, and α-thujene, geranyl acetate, α-bisabolol oxide and 1-octene-3-ol acetate after flowering). Furthermore, the differences in quantities of all compounds present in the essential oils were also recorded. However, the qualitative composition of main constituents of the essential oil in all the three investigated stages led to the suggestion that the menthofuran, as the major compound could be used as the stable chemosystematic marker in the Mentha aquaticaL. taxonomy.

This literature review presents an historical perspective and basic principles of the isolated-perfused heart and gives examples of its current usage together with some personal research data. Heart function, both under conditions of health and disease, is regulated at the molecular, cellular, organ and whole organism level. To address regulation of the heart at various levels, a vast variety of experimental models ranging from man to a single molecule are needed. The isolated mammalian heart preparation, perfused with a blood-free medium, whole blood, or blood components according to Langendorff, has provided reliable information on the condition of the working musculature, the conduction system and the coronary vessels in various conditions. Due to the technical ease by which these functions of the heart can be analyzed, the preparation has been frequently used as a research tool. The molecularly based understanding of the heart will hopefully be a source for new treatments of common cardiac conditions, such as heart failure, cardiomyopathy and dysrhythmias. Thus, the isolated-perfused heart will be further used to test the heart's function under various circumstances. Advances in the conditions that increase stability and extend the life of this preparation could also contribute to its prolonged and expandable usage.

This review summarizes physiology of circulating and local reninangiotensin system (RAS), enzymatic properties and mechanism of action of angiotensin I converting enzyme inhibitors (ACEIs) on RAS, and implications of ACEIs in anesthetic management of patients treated with these drugs. ACEIs, through their effect on RAS, may improve cardiovascular functions, pulmonary dynamics, and body fluid homeostasis. Thus, ACEIs have become an integral part of management of patients with hypertension, congestive heart failure (CHF) and chronic renal disease. ACEIs, due to differences in their chemical structure, exert different pharmacological actions and can have protective or occasional damaging effects on different organs. The anesthesiologists are commonly involved in the management of patients treated with ACEIs. Thus, the role of ACEIs and their possible interaction with anesthetic agents must be an integral part of clinical decision-making during anesthesia Hemodynamic variation during anesthesia is mainly related to specific effects of anesthetic agents on sympathetic nervous system. Those with preoperative fasting, volume depletion and extended sympathetic blockade can have reduced vascular capacitance resulting in decreased venous return, reduced cardiac output and severe arterial hypotension. Angiotensin II (ANG2) a potent vasoconstrictor may counterbalance such hypotensive effect. During ACE inhibition ANG2 cannot counterbalance this hypotension. Thus, induction of anesthesia may cause severe hypotension in hypovolemic patients specifically in those receiving diuretics as a complement to ACEIs. Recent advances in RAS and the pharmacology of ACEIs have identified some predisposing factors and risks associated with anesthesia in patients treated with ACEIs. Practitioners should be vigilant, and readily have vasopressors, necessary fluids and other resuscitative measures for treatment of unexpected hemodynamic instability during anesthesia and surgery.

This review summarizes some basic properties and distribution of angiotensin I converting enzyme (ACE). ACE is one of several biologically important ectoproteins that exists in both membrane-bound and soluble forms. Localized on the surface of various cells, ACE is inserted at the cell membrane via its carboxyl terminus. Human plasma ACE originates from endothelial cells while other body fluids may contain ACE that originates from epithelial, endothelial or germinal cells. The two isoforms of ACE, the two-domain somatic form and the single domain germinal form, convert angiotensin I to angiotensin II, and metabolize kinins and many other biologically active peptides, including substance P, chemotactic peptide and opioid peptides. The broad spectrum of substrates for ACE and its wide distribution throughout the body indicates that this enzyme, in addition to an important role in cardiovascular homeostasis, may be involved in additional physiologic processes such as neovascularization, fertilization, atherosclerosis, kidney and lung fibrosis, myocardial hypertrophy, inflammation and wound healing. Future research should explore the possible functions of tissue ACE and its systemic role as a pressor agent. ACE inhibitors have achieved widespread use in the treatment of hypertension and the protection of endorgan damage in cardiovascular and renal diseases. Potential problems related to side effects and compliance of such therapy need to be adressed. A safer way of producing therapeutic effects is promised by the delivery of the ACE antisense sequences by a vector producing a permanent inhibition of ACE and long-term control of blood pressure in hypertensive patients.

A new physically-based compact device model of the PiN diode is presented. A one-dimensional model for the drift zone (low doped n-base region) is presented which accurately describes conductivity modulation and non-quasistatic charge storage effects within the structure. To validate the power diode compact model, simulation results are compared with those from a detailed drift–diffusion finite-element model, as well as with experimental results (for two different devices), showing an excellent agreement in all cases. The model is found to be efficient and robust in all cases examined.

A 27-year-old man with a history of acne presented to his primary care physician because of fatigue and dyspnea on exertion of 4 weeks' duration. He was remarkably pale, orthostatic pulse changes were noted, and a systolic ejection murmur was heard. The patient had profound anemia (hemoglobin concentration, 5.0 g/dL) and neutropenia (neutrophil count, 0.06 × 109/L); he was admitted for further evaluation. A detailed inquiry into his medication history revealed that he was taking several vitamins and zinc gluconate, 850 to 1000 mg/d for 1 year (US recommended daily allowance, 15 mg), as therapy for acne. A zinc toxic and copper-deficient state was confirmed by laboratory studies. The patient was treated with intravenous copper sulfate, followed by 3 months of oral therapy. The complete blood cell count, serum copper level, and serum zinc level returned to normal.

Introduction: The purpose of the present study was to develop a simple method for the simultaneous determination of mepivacaine, tetracaine, and p -butylaminobenzoic acid (BABA) in human plasma using high-performance liquid chromatography (HPLC) with a multiwavelength detector. Methods: Human blood samples containing heparin, as an anticoagulant, and physostigmine (100 μg/ml), as an anticholinesterase, or human plasma containing physostigmine were spiked with various concentrations of mepivacaine, tetracaine and, in some cases, BABA. Blood samples were centrifuged and plasma was deproteinized with trifluoroacetic acid (TFA; 7%). After centrifugation, the pH was adjusted to 4.5 and an aliquot of 20, 50 or 100 μl was injected into the HPLC apparatus. The detection was done simultaneously at wavelengths of 214 and 300 nm. Analytical chromatography was done on a Waters μBondapak C 18 reverse-phase column (3.9×300 mm; particle size 10 μm) with a 30-min increasing linear gradient of 20-40% acetonitrile+0.05% TFA in H 2 O+0.05% TFA at a flow rate of 1 ml/min. The Waters HPLC system included two pumps, an automatic injector, a column oven, and a M490 multiwavelength detector. Quantification was done using integration of peak areas with peaks of authentic mepivacaine, tetracaine, and BABA standards. Results: Calibration curves for standards of mepivacaine, tetracaine, and BABA were linear in the concentration ranges from 0.1 to 100 μg/ml, and the correlation coefficients exceeded .99 for all compounds. The lower limits of detection were 100 ng/ml for mepivacaine and 50 ng/ml for tetracaine and BABA. The yields for mepivacaine, tetracaine, and BABA were 91±2.1%, 82±3.3%, and 88±2.0% (mean±S.E.M., n =6), respectively. Degradation of tetracaine by human plasma at 37 °C was inhibited by physostigmine. Discussion: The method is sensitive enough to allow blood concentration determinations of mepivacaine and tetracaine or its metabolite, BABA, following local anesthesia induced by these two drugs, especially when their toxic effect may be present. This method also may be useful in forensic medicine for determination of the cause of death after local anesthesia with mepivacaine and/or tetracaine.

Physically based compact device models of the MOSFET, as well as PiN diode and insulated gate bipolar transistor (IGBT) are presented in this paper. For the correct description of static and dynamic behaviour of power bipolar devices (IGBT and PiN diode) a 1D module for the drift zone (low doped n-base region) is presented that incorporates conductivity modulation and non-quasistatic charge storage effect. Finally, it is possible to transform, relatively easily, these electric models into the electrothermal models by adding an extra node (thermal node) to the electrical compact models. This thermal node will store information about junction temperature of the active device and it represents a connection between the device and rest of the circuit thermal network.

The mussel Mytilus galloprovincialis has been studied in situ as a fouling organism in the north-eastern part of the Adriatic Sea, in waters ranging from relatively clean to those contaminated by pollutants of urban and industrial origin (oil pollution, fish processing plant). Observations were made with artificial substrata (glass, wood, metal, PVC, wooden fishing ships) exposed for 7, 14 and 30 days and from 2 to 14 months. The studies included parameters such as frequency of occurrence, abundance, grade of abundance, dominance, length of valve, cover and biomass; the qualitative degree of pollution was also determined for each site investigated. Mussels prefer the mediolittoral and upper infralittoral zones, slight urban-industrial pollution of organic origin, cleaner environments (primarily rich in food), shorter time of substratum exposure (up to one month), inert substrata (transparent glass, unprotected wood) and parts of ships protected from stronger water movements. The most unfavourable conditions for mussels include high silting (totally limiting), oil pollution (almost to totally limiting), nutrient-poor coasts, long time of exposure (substantial fouling competition), toxic coating (particularly for wood), and parts of ships more exposed to high water speed when in motion.

Laser interferometry was used to measure umbo velocity in the developing rat. The tympanic membrane was stimulated with pure tones between 0.4 and 40.0 kHz, at intensity levels between 50 and 130 dB SPL. The corresponding umbo velocity response was measured. Umbo velocity responded linearly with respect to sound pressure throughout development. When the stimulus level was held constant at 100 dB SPL, all animals displayed a velocity response that increased with frequency until a peak response was reached at about 20.0 kHz. Above this frequency the response decreased in all age groups. Umbo velocity increased with age at all frequencies, and at 1.0, 2.0, 4.0, 8.0, 16.0, and 32.0 kHz the velocity reached 90% of its mature value by 68, 24, 24, 15, 19, and 50 days after birth, respectively. These age‐related increases in tympanic membrane velocity coincided with improvements in compound action potential (CAP) thresholds (as measured by other investigators) at similar frequencies. Both umbo velocity and CAP thresholds showed substantial growth after 10 days of age. The role of middle‐ear functional development with respect to overall auditory sensitivity is discussed. © 1996 Acoustical Society of America.

Rats were adrenalectomized and injected for 7 days with dexamethasone (DEX) or deoxycorticosterone. Kallikrein and prekallikrein were assayed in urine and in a basolateral membrane-enriched fraction. The activities of renin and phospholipase A2 were also determined in the fraction. Adrenalectomy significantly decreased active kallikrein in urine. Administration of deoxycorticosterone raised the level of active kallikrein in urine without affecting the concentration of prekallikrein. Rats treated with DEX only had high Na+ and low active kallikrein excretion. The total kallikrein level (active kallikrein together with prekallikrein), however, returned to normal because DEX elevated the prekallikrein level. DEX also increased the prekallikrein concentration in the membrane-enriched fraction. Renin activity in the membrane-enriched fraction was enhanced by adrenalectomy but suppressed by either corticosteroid. The changes in the concentration of plasma renin were qualitatively similar but quantitatively different. The activity of phospholipase A2 in the membrane-enriched fraction was enhanced only by deoxycorticosterone. Thus, both gluco- and mineralocorticoids increased kallikrein excretion in the adrenalectomized animals, but DEX was apparently effective at a lower dose than deoxycorticosterone. DEX increases the prekallikrein concentration in urine and on the basal membrane of distal tubular cells and, in addition, may prevent its conversion by releasing an inhibitor of a prekallikrein activator.

The role of pigments in generating the colour and maculation of birds' eggs is well characterized, whereas the effects of the eggshell's nanostructure on the visual appearance of eggs are little studied. Here, we examined the nanostructural basis of glossiness of tinamou eggs. Tinamou eggs are well known for their glossy appearance, but the underlying mechanism responsible for this optical effect is unclear. Using experimental manipulations in conjunction with angle-resolved spectrophotometry, scanning electron microscopy, atomic force microscopy and chemical analyses, we show that the glossy appearance of tinamou eggshells is produced by an extremely smooth cuticle, composed of calcium carbonate, calcium phosphate and, potentially, organic compounds such as proteins and pigments. Optical calculations corroborate surface smoothness as the main factor producing gloss. Furthermore, we reveal the presence of weak iridescence on eggs of the great tinamou (Tinamus major), an optical effect never previously documented for bird eggs. These data highlight the need for further exploration into the nanostructural mechanisms for the production of colour and other optical effects of avian eggshells.

An advanced strategy is presented for modelling thermal stress induced in aluminium interconnections during processing. The advantage of the approach described is that it allows the residual stresses from one technological step to be used as an initial condition for subsequent steps. The particular example demonstrated here is for a passivated aluminium line (silicon-glass-aluminium-glass), however, the technique is readily extendible to more complex situations and material combinations.