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EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25th of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Current naval ships were designed without considerations for the air wake encountered on the flight deck. Naval frigates superstructures design has resulted in a sharp-edges box type that generates a wake dominated by highly turbulent recirculating flows. These flows can affect the safety of the helicopter during the takeoff and landing maneuvers. This paper presents wind tunnel tests performed in order to obtain a more complete insight and understanding of the typical flow on a simple frigate shape. Moreover, a solution to reduce the influence of the wake flow above the flight deck and a risk reduction for on-board helicopter operations is proposed by modifying the usual frigate geometry. Four simple frigate shape hangar roof configurations were investigated by wind tunnel testing. Measurements of the velocity and pressure fields on the flow above the flight deck were performed and results compared in order to evaluate the effectiveness of the modified hangar roof design.

Objective Previous trials have shown little benefit for preventing preterm birth in twin pregnancies using 90–200 mg of daily vaginal natural progesterone. Higher doses have not been tested. Our aim was to determine the efficacy and safety of two different daily doses of vaginal natural progesterone (200 and 400 mg), compared with placebo, for preventing preterm birth in unselected twin pregnancies. Design Randomised controlled double-blind multicentre trial (1:1:1). Setting The study was carried out in five university centres from Valencia, Murcia and Alicante (Spain). Population Women with dichorionic diamniotic twin pregnancies. Methods The women self-inserted two vaginal pessaries daily, containing placebo (n = 96), 200 mg of natural progesterone (n = 97) or 400 mg of natural progesterone (n = 97), from 20 to 34 weeks of gestation or delivery. Randomisation was performed by an external centre. Data were analysed on an intention-to-treat basis. Main outcome measure Preterm birth rate. Results The baseline characteristics for placebo and progesterone groups were similar. Comparison of the three groups and analysis of progesterone-treated versus untreated women showed similar pregnancy and neonatal outcomes. The proportion of preterm and very preterm births, low birthweight, perinatal mortality and neonatal morbidity showed no differences between the three groups. Similar results were also obtained when comparing the 200- versus 400-mg progesterone groups. No serious adverse effects were encountered. Conclusions Vaginal progesterone therapy was generally well tolerated, but failed to prevent preterm births in unselected dichorionic diamniotic twin pregnancies. The 400-mg progesterone dose offered no advantages over the 200-mg regimen.

Aerodynamic loads on railway vehicles under cross winds are governed both by the shapes of the vehicles and of the surroundings. Apart from the inertial loads due to accelerations acting on the vehicle, aerodynamic loads due to cross winds are of paramount importance in the lateral equilibrium of the vehicle, in such a way that if the lateral wind speed becomes larger than a threshold value, overturning of the vehicle can take place. The degree of danger of overturning increases when the train is on a bridge, the reason being that the velocity in the atmospheric boundary layer grows as the height increases, leaving aside the fact that at ground level there may be other elements acting as windbreaks (mainly vegetation). The effects of different types of solid parapets on the side force and rolling moment acting on a 1/70 scale two-dimensional model of a typical high-speed train vehicle have been measured by wind-tunnel tests, both when the vehicle is placed on a bridge and when it is on ground. Experimental results show that, as one could expect, aerodynamic loads decrease as the height of the windbreak increases, and that solid parapets seem to be more effective on bridges than on ground.

Background: The aim of this study is to establish the efficacy and safety of rupatadine vs ebastine and placebo in the treatment of seasonal allergic rhinitis (SAR). Rupatadine is a new second generation H1-antihistamine with once-daily dosing that may provide better control of symptoms than the currently used H1-receptor blockers because of its dual pharmacological profile (anti-PAF and anti-H1). Methods: In a multicentre study, 250 patients with SAR were included in a double-blind, randomized, parallel-group and placebo-controlled study. Patients received either rupatadine 10 mg, ebastine 10 mg or placebo once daily for 2 weeks. The main efficacy outcome was based on the patient's record of severity of nasal symptoms (sneezing, nasal itching, runny nose and nasal obstruction) and nonnasal symptoms (conjunctival itching, tearing and pharyngeal itching). The daily total symptom score (DTSS) was the mean of the DSS recorded for each of the seven symptoms assessed, and the mean DTSS (mDTSS) was the mean of the DTSS values for each study day. Results: Significant differences in mDTSS were detected between rupatadine and placebo (33% lower for rupatadine group; P = 0.005) after 2 weeks of treatment. The TSS for rupatadine were 22% lower than for ebastine, although the differences were not statistically significant. No serious adverse events were reported during the study period. Conclusions: Rupatadine 10 mg once daily was clearly superior to placebo in alleviating the symptoms of SAR over a 2-week period. In comparison with ebastine, rupatadine shows a trend towards a better profile as regard several secondary efficacy variables.

There is a self-similar solution for the stability limits of long, almost cylindrical liquid bridges between equal disks subjected to both axial and lateral accelerations. The stability limits depend on only two variables; the so-called reduced axial, and lateral Bond numbers. A novel experimental setup that involved rotating a horizontal cylindrical liquid bridge about a vertical axis of rotation was designed to test the stability limits predicted by the self-similar solution. Analytical predictions compared well with both numerical and experimental results.

GARSON is a new approach to autonomic and cognitive network management. This paper describes the main features of GARSON and its position among similar approaches. GARSON consists of several ‘planes’ playing different roles in the network management hierarchy. The autonomic monitoring plane and autonomic actuating plane of GARSON are described in more detail. The basic structure of GARSON network components is provided as well. The conclusions are drawn at the end of this paper, showing the possible usage areas of GARSON.

The problem of determination of the turbulence onset in natural convection on heated inclined plates in an air environment has been experimentally revisited. The transition has been detected by using hot wire velocity measurements. The onset of turbulence has been considered to take place where velocity fluctuations (measured through turbulence intensity) start to grow. Experiments have shown that the onset depends not only on the Grashof number defined in terms of the temperature difference between the heated plate and the surrounding air. A correlation between dimensionless Grashof and Reynolds numbers has been obtained, fitting quite well the experimental data.

The problem of determination of the turbulence onset in natural convection on heated inclined plates in an air environment has been experimentally revisited. The transition has been detected by using hot wire velocity measurements. The onset of turbulence has been considered to take place where velocity fluctuations (measured through turbulence intensity) start to grow. Experiments have shown that the distance to the plate edge where the onset begins depends both on the plate inclination angle and the plate temperature, and thus on the Grashof number defined in terms of the temperature difference between the heated plate and the surrounding air. An experimental setup to measure the above mentioned distance has been developed. In this paper, such an apparatus is presented, as well as the experimental procedure and some experimental results.

This paper describes how aerodynamic loads on train vehicles under cross winds are governed both by the shapes of the vehicles and of the surroundings. Aerodynamic loads due to cross winds are of paramount importance in the lateral equilibrium of the vehicle, in such a way that if the lateral wind speed becomes larger than a threshold value the overturning of the vehicle can take place. The degree of danger against overturning increases when the train is on a bridge, the reason being that the velocity in the atmospheric boundary layer grows as the height increases, leaving aside the fact that at ground level there may be other elements acting as windbreaks (mainly vegetation). The effects of different types of parapets, either solid or porous, on the wind protection of a train vehicle on a bridge under cross wind have been visualized by smoke wind-tunnel tests. In addition the effects of several types of solid parapets on the side force and rolling moment acting on a two-dimensional model of the same high-speed train coach have been measured by wind-tunnel pressure measurements. Experimental results show that, as one could expect, solid parapets seem to be more effective than porous ones, and the aerodynamic loads decrease as the height of the windbreak increases.

The effect of different acids on the efficiency of lead hydride generation in potassium dichromate oxidant medium was investigated and lactic acid-potassium dichromate was found to give optimum lead hydride generation. Various parameters affecting sensitivity and the influence of interfering ions were studied. The sensitivity of the method (0.44 ng) is greater than published values for ammonium peroxodisulphate-nitric acid (20.0 hg) and hydrogen peroxide-nitric acid (10.0 ng). This could be because lactic acid stabilizes the Pb(IV) metastable compounds more effectively, acting as intermediate species in lead hydride formation. The method was applied to the determination of lead in liquids (tap water and wine) and fish and vegetable samples. The liquids were analysed directly without preconcentration or mineralization and the solids after wet digestion or slurry formation; these two sample preparation methods gave similar results.

Background Anisakis simplex is a helmintic parasite of fish and shellfish that can induce in humans, after consumption, an immunoallergic response with multiorganic affectation, especially cutaneous (urticaria and angioedema), gastrointestinal and anaphylactic symptoms. Nephrotic syndrome can be produced by helmintic infection, especially schistosomiasis. Objective To report the unusual case of nephrotic syndrome associated to an allergic response to A. simplex . Methods A 60-year-old woman suffered from nephrotic syndrome three weeks after a generalized urticaria, angioedema and nauseas episode, following a raw anchovy's ingestion. Etiological study of nephrotic syndrome and urticaria/angioedema, cutaneous test, serum total and specific IgE determination, IgE-immunoblotting, and HLA typing were performed for diagnostic evaluation. Results Prick-test with A. simplex extract was positive. It was observed a significance increase of total IgE to the three weeks of anchovy's ingestion and then it diminished progressively. Specific IgE to A. simplex was > 100 UI/ml. Immunoblotting to A. simplex , revealed the existence of IgE-binding proteins with molecular mass ranging from 20 kDa to 99 kDa. Class I HLA expressed by the patient was type HLA-B12. Other secondary causes of nephrotic syndrome were carefully ruled out. Conclusions These data suggest, for the first time, the association between allergy to A. simplex and nephrotic syndrome.

The response of a long cylindrical liquid column subjected to an axial microgravity field has been experimentally studied on a TEXUS sounding rocket flight to check with theoretical predictions. The expected response of the liquid bridge was a quasi-static amphora-type deformation of the cylindrical shape. However, the experimental results showed a more complex behaviour. Nevertheless it has been possible to find out the reasons of this discrepancy except for a mysterious 0.5% uncertainty in the stimuli.

The testis is a tightly controlled dynamic tissue. In mammals, there is growing evidence that estrogen plays a role in the regulation of testicular functions. In teleosts, high levels of 17beta-estradiol (E2) in serum correlate with the end of spermatogenesis, spawning, and the initiation of postspawning stages when spermatogonia are the main cell types in the testis. Moreover, E2 modulates leukocyte functions in several teleost species. We hypothesized, therefore, that E2 would induce the infiltration of acidophilic granulocytes and cause a resumption of testicular cell proliferation in spermatogenically active gilthead seabream males. Several studies of this species have reported that supraphysiological doses of E2 are needed to induce histological and developmental changes in males. In fact, as gilthead seabream is a protandrous hermaphrodite teleost, long exposures (6-14 wk) to high doses of E2 result in feminization of the males. Taking all this into account, we sharply increased E2 levels during short times by i.p. injecting E2 diluted in coconut oil as the vehicle and sampled the fish after 7, 13, and 18 days to assess the effects that E2 had on spermatogenesis. It was observed that E2 levels in plasma increased, while 11-ketotestosterone (11-KT) and testosterone (T) levels remained unaltered. However, 11-KT and T levels strongly increased in control fish 18 days postinjection. The most relevant result of our study was that E2 accelerates the final events of spermatogenesis, inhibits the proliferation of spermatogonia in early stages, and induces some of the processes that usually occur during postspawning, such as the infiltration of acidophilic granulocytes and the apoptosis of primary spermatogonia. Strikingly, neither the shedding of spermatozoa nor an increase in the proliferative rate of spermatogonia stem cells was observed, probably because of the lack of other necessary stimuli, such as the increase in T levels that takes place during normal postspawning.

Anaesthesia may depress the immune system in mammals, but there is no available information on this topic in fish. In the present work, four anaesthetics that are used in aquaculture, MS222 (0 19 mM), benzocaine (0.21 mM), 2-phenoxyethanol (16 mM) and quinaldine sulphate (0.083 mM), were tested in order to observe their effects on the gilthead seabream (Sparus aurata L.) innate immune system. The results showed that the four anaesthetics produced increased blood glucose levels after an hour. In addition, benzocaine and 2-phenoxyethanol depressed complement activity and phagocytosis, while MS222 and quinaldine sulphate did not. Some anaesthesia is a common practice in aquaculture, the data obtained should be taken into account to avoid possible immunodepression in farmed fish.

The natural cytotoxic activity of head-kidney leucocytes from gilthead seabream (Sparus aurata L.), after in vitro and in vivo vitamin E treatment, against tumor cells was studied by flow cytometry. Leucocytes were incubated in culture medium with different vitamin E supplementations (0.01-10 microg ml(-1)) for 6, 24 or 48 h and the results demonstrate that all the assayed vitamin E supplementations significantly enhanced the natural cytotoxic activity of leucocytes. To determine the effect of a high dietary level of vitamin E on this activity, fish were fed with 0 (control), 600, 1200 or 1800 mg of vitamin E supplementation kg(-1) diet for 2, 4 or 6 weeks. After 2 and 4 weeks of treatment, the natural cytotoxic activity was significantly enhanced at the highest (1.8 g kg(-1) diet) and lowest (600 mg kg(-1) diet) vitamin E supplement dosage, respectively. No effect of the vitamin E supplemented diet on seabream leucocyte natural cytotoxic cell activity was observed after 6 weeks of treatment.

To determine the effects of chitin (poly [1--4]-beta-N-acetyl-D-glucosamine) on the innate immune response of gilthead seabream (Sparus aurata L.), fish were fed diets containing 0 mg (control), 25, 50 or 100 mg kg(-1) chitin for 2, 4 and 6 weeks. Lysozyme and natural haemolytic complement activities, together with head-kidney leucocyte respiratory burst, phagocytic and cytotoxic activities, were studied at each of the assayed times. Lysozyme activity was unaffected by the administration of chitin. The innate humoral and cellular immune response activities assayed were enhanced by the dietary intake of chitin, each increasing at a different time: natural haemolytic complement activity and cytotoxic activity after 2 weeks of treatment, respiratory burst activity from 4 weeks and phagocytic activity after 6 weeks, although, unlike the other activities, no statistically significant differences were observed in the first. The results indicate that chitin increases the activity of the seabream innate immune system, and its use as an immunostimulant is discussed, especially with regards to the protective role.

Gilthead seabream specimens were subjected to an intense short-term crowding stress of 100 kg m(-3) for 2 h. After 0, 1, 2, 3 and 4 days, blood glucose and serum cortisol levels, serum complement activity, phagocytic and respiratory burst activities of head-kidney leucocytes, and the percentage of monocyte/ macrophages and granulocytes in head-kidney and circulating blood were determined. An immediate effect of the stress was a depression in complement and phagocytic activities, both of which recovered after 3 or 2 days, respectively, while respiratory burst remained unaffected. The depression of phagocytosis in head-kidney leucocytes seemed to correlate with stress-induced migration of active cells from the organ to circulating blood. The present results point to the importance of minimising intense short-term crowding stress in order to reduce possible states of immunodepression in farmed fish.

To determine the effects of chitin (poly [1--4]-beta-N-acetyl-D--glucosamine) particles on the innate immune response of gilthead seabream (Sparus aurata L.), specimens were injected intravenously or intraperitoneally with the substance. Natural haemolytic complement activity, head-kidney leucocyte respiratory burst activity and phagocytic and cytotoxic activities were analysed in vitro 3, 5 or 10 days post-injection. All the immune parameters assayed remained unaffected when chitin was intravenously administered. However, the fish that had been intraperitoneally injected showed increased humoral and cellular immune responses. Natural haemolytic complement activity increased from 5 days post-injection although no statistically significant differences were observed. Respiratory burst and phagocytic activities peaked at 3 and 5 days post-injection, respectively, while cytotoxic activity had increased by 3 days post-injection and remained high until 10 days post-injection.

To determine the effects of three high levels of dietary intake of alpha-tocopherol acetate (vitamin E) on the non-specific immune response of gilthead seabream (Sparus aurata L.), specimens were fed a commercial diet (100 mg alpha-tocopherol kg-1) as control, or vitamin E supplemented diets (600, 1200 or 1800 mg alpha-tocopherol acetate kg-1) for 15, 30 or 45 days. Growth, serum alpha-tocopherol levels, natural haemolytic complement activity and head-kidney leucocyte migratory, respiratory burst and phagocytic activities were studied at each of the assay times. A positive correlation between alpha-tocopherol acetate intake and serum alpha-tocopherol levels was observed, the increase being linked to both the dosage and length of treatment. Specimens fed the diet supplemented with 600 mg vitamin E kg-1 showed no enhancement in any of their immune parameters, while those fed the diet supplemented with 1200 mg vitamin E kg-1 presented a slightly higher (but not statistically significant) specific growth rate than fish fed the other diets. In addition, serum haemolytic activity and the phagocytosis of head-kidney leucocytes were enhanced by the dietary intake of 1200 mg vitamin E kg-1 after 30 and 45 days of treatment, although leucocyte migration and respiratory burst activity remained unaffected. The highest vitamin E dietary dose used, 1800 mg kg-1, unexpectedly provoked no immunostimulation. These results indicate that a moderate level of vitamin E in the diet (1200 mg kg-1) stimulates the seabream's non-specific immune system after 30 days of administration. Lower or higher vitamin E concentrations may not be so effective, because of an imbalance in the vitamin E ratio with other antioxidants. The proposed dietary levels of vitamin together with the indicated administration time could be useful for reducing the susceptibility of farmed fish to infectious diseases.

This paper describes an easy and sensitive flow cytometric assay for assessing the non-specific cytotoxic activity of gilthead seabream (Sparus aurata L.) head-kidney leucocytes against tumor target cells. Concomitantly, the cytotoxic process and the cell types involved were microscopically studied. The assay was based on the consecutive use of two fluorochromes. The targets were preincubated with 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO) and then mixed with effectors. At the end of incubation time propidium iodide (PI) was added. While live effectors were non-fluorescent, live and dead targets retained the DiO (green) fluorescence and non-viable targets and effectors showed PI (red) fluorescence staining. The kinetics of the cytotoxic activity was studied from 10 to 240 min. Lymphocytes, monocyte-macrophages and granulocytes showed non-specific cytotoxic activity, as demonstrated by light and electron microscopy. In conclusion, the technique presented validates the effectiveness of a dual-color flow cytometric assay for assessing the activity of non-specific cytotoxic cells in fish.

The presence of infective endocarditis with appearance of vegetations over the tricuspid valve in patients with permanent pacemaker is an uncommon complication. We report here three patients with permanent cardiac pacemakers who developed a picture of infective endocarditis over the electrode with appearance of vegetations over the native valve. The microorganism recovered from blood cultures in the three patients was Staphylococcus. The presence of retained pacemaker leads and repetitive surgical procedures over the pacemaker pouch are two risk factors reported in literature also present in our patients. Infective endocarditis is an uncommon difficult-to-diagnose complication, with a poor prognosis and which requires the removal of the whole infected material, with implantation of an epidermal pacemaker. Some diagnostic and therapeutic issues are discussed.

Between 1st January 1988 and 30th June 1996, a total of 165 patients (115 males, 50 females; mean age 66.8 years) underwent isolated aortic valve replacement with Carpentier-Edwards supra-annular porcine bioprostheses in our unit. Our clinical experience with this device is reported.In this retrospective study, mortality and complications observed in these patients were analyzed. Complications appearing with a non-biased time-course were expressed by means of linearized rates. Actuarial analysis was performed using the Kaplan-Meier method.Cumulative follow up was 551.2 patient-years, with a mean follow up of 3.5 years per patient. The hospital mortality rate was 6.7%. Linearized rates (events per 100 patient-years) and actuarial probabilities of freedom from the different complications at 8.5 years follow up, respectively, were: late mortality, 4.5 and 58.6%; valve-related mortality, 1.1 and 82.6%; thromboembolism, 1.3 and 92.7%; prosthetic endocarditis, 0.5 and 97.4%; non-structural dysfunction, 0.5 and 94.7%; structural deterioration, 0.5 and 91.6%; reoperation, 0.5 and 94.2%. Actuarial freedom from any valve-related mortality or morbidity at 8.5 years was estimated at 66.3%.The Carpentier-Edwards supra-annular bioprosthesis, when implanted in the aortic position, presents a low rate of valve-related complications at this length of follow up. However, the limited life expectancy of our patients undergoing aortic valve replacement with bioprostheses (usually elderly subjects) may overshadow the potential good performance of this device.

Although phagocytosis is considered the main nonspecific defense mechanism in fish, the significance of the influence of bacterial properties and assay conditions on this mechanism has not been established. We report the influence of leukocyte source, bacterial species, presence or absence of a bacterial wall, bacterial status (live or dead), and bacterial opsonization on in vitro phagocytosis by sea bass (Dicentrarchus labrax L.) macrophages.Leukocytes were challenged with bacteria under different conditions and ultrastructurally studied. The number of phagocytic macrophages and the number of bacteria ingested per macrophage were quantified by microscopical counting, and the data obtained were statistically analyzed following general linear models.Macrophages from sea bass peritoneal exudate showed a greater capacity to engulf bacteria than did those isolated from blood, which, in turn, had greater engulfment properties than did those isolated from head-kidney. Greater phagocytic activity was observed in the assays carried out with Escherichia coli than in those carried out with Salmonella typhimurium, especially when the TA1950 S. typhimurium strain (with wall) was used. Macrophages showed greater phagocytic activity against live bacteria. Bacterial opsonization had a variable effect on phagocytosis. Sea bass macrophages did not always ingest the same number of bacteria.Sea bass macrophages have strong bacterial phagocytic activity. Significant differences were found that had been influenced by bacterial properties as well as by assay conditions. Positive correlation between the number of phagocytic macrophages and the number of bacteria ingested per phagocyte was observed.

Intravenous leiomyomatosis spreading through the inferior vena cava to the right heart is a rare neoplasm. We report the case of a patient with a uterine leiomyoma which through a right uterine vein progressed along the inferior vena cava up to the right ventricle. She was successfully operated, carrying out a total resection in two surgical stages. Surgical technique considerations are discussed.

This volume constitutes the proceedings of the First International Workshop on Rewriting Logic, held at the Asilomar Conference Center, Pacific Grove, California, Sept. 2-6, 1996. The three invited papers by Narciso Marti-Oliet, Ugo Montanari, and Martin Wirsing, and seventeen contributed papers selected by the Program Committee give a rich view of the latest developments and research directions in the field of rewriting logic and its various applications to computing. Besides work on models and on concurrency aspects, there are several papers describing the different rewriting logic languages developed so far in Europe and the U.S., as well as a paper on semantic foundations for the Cafe language in Japan. There are also several papers on logical and metalogical specification; on reflection and strategies; on applications to object-oriented design, specification and programming; and on applications to contraint solving, to real-time systems, and to discrete event simulation. In addition to the papers, the workshop placed strong emphasis on facilitating in-depth discussion of the topics by allowing ample time for the discussion of each paper, and by including five panel discussions and a tutorial.

Head-kidney, considered the major fish lympho-haemopoietic tissue, consists of cells of the different haemopoietic series supported by a network of stromal cells whose morphofunctional properties have not been established. We report the ultrastructure and cytochemical features of the reticulo-endothelial stroma of the head-kidney from the seawater teleost gilthead seabream (Sparus aurata L.).Samples of head-kidney were processed for electron microscopic study. Some of the samples were incubated for acid and alkaline phosphatase, peroxidase, glucose-6-phosphatase, or ATPase.The reticulo-endothelial stroma of gilthead seabream head-kidney consists of sinusoidal cells (endothelial and adventitial cells) and reticular cells (macrophage-type reticulum and fibroblast-like reticular cells). Transcytosis vesicles and rounded medium electron-dense granules were observed in the cytoplasm of the endothelial cells. The adventitial cells partially covered the outside surface of the endothelial cells and were joined by desmosomes. The macrophage-type reticulum cells were characterized by their cytoplasmic processes and acid phosphatase positive lysosomes. The fibroblast-like reticular cells were joined by desmosomes and formed an extensive network between the haemopoietic parenchyma. They were peroxidase negative and acid and alkaline phosphatase, glucose-6-phosphatase, beta-glucuronidase, and ATPase positive.The ultrastructural and cytochemical features of the reticulo-endothelial stroma of the gilthead seabream head-kidney are similar to those of mammalian bone marrow, suggesting phylogenetic analogies between both tissues.

The peripheral blood cells of the gilthead seabream (Sparus aurata L.) were studied by light and transmission and scanning electron microscopic methods. Acidophilic erythroblasts and mature erythrocytes, round, oval, and fusiform thrombocytes, neutrophils, acidophils and basophils, lymphocytes, plasma cells, and monocyte-macrophages were characterized. A comparison of our light and electron microscopic results was carried out. The results were discussed with those for other fish species and the main modifications from the common vertebrate haematological pattern observed being considered.

In this paper the dynamics of axisymmetric liquid columns held by capillary forces between two circular, concentric, solid disks is considered. The problem has been solved by using an one-dimensional model known in the literature as the Cosserat model, which includes viscosity effects, where the axial velocity is considered constant in each section of the liquid bridge. The dynamic response of the bridge to an excitation consisting of a small amplitude vibration of the supporting disks has been solved by linearising the Cosserat model. It has been assumed that such excitation is harmonic so that the analysis has been performed in the frequency domain and the dependence of the frequency of resonance corresponding to the first oscillation mode on the parameters defining the liquid bridge configuration as well as the axial microgravity level has been calculated for several liquid bridge configurations.

The ultrastructure of granulopoiesis in the head-kidney of the sea bass (Dicentrarchus labrax L.), an euryhaline seawater teleost, was studied. The heterophilic, acidophilic and basophilic series consisting of promyelocyte, myelocyte, metamyelocyte and mature granulocyte stages are described. The granulopoietic pattern was similar to those of higher vertebrates but dissimilar to those of some other fish, suggesting that the vertebrate granulopoietic scheme was probably conserved during the evolution of at least some teleost species. Very scare presumptive blast cells were present. The heterophilic series showed three types of granules that might correspond to nucleated, azurophil and specific granules which have been described in neutrophils from mammals and human bone marrow. Neither a crystalloid nor a dense core was found in the granules of acidophilic granulocytes, where an occasional light zone could be seen. The scarce cells of the basophilic series showed similar characteristics to those described in other fish species.

The ultrastructure of irradiated rabbit thyroid gland (0 Gy, as control, 4 Gy, 8 Gy, 12 Gy, 16 Gy and 20 Gy X-ray) is studied. The thyroid gland of the control group shows ultrastructural features similar to those described in other mammals. Modifications in follicular ultrastructure and interfollicular connective tissue ultrastructure as well as the presence of small thyroid follicles, probably neoformed, are found to be dose-dependent. Follicular epithelium varies from simple cuboidal to simple squamous, the latter being characteristic of the highest X-ray dose. Follicular cells show numerous cytoplasmic light vesicles and a very extensive rough endoplasmic reticulum consisting of vacuolated cisternae. Sloughed cells are present at 8 Gy. A well-developed interstitial glandular tissue consisting of extensive extracellular matrix, abundant collagen fibres and dilated, irregularly outlined capillaries are also present.

Mugil cephalus and Liza saliens nephrons consist of renal corpuscles, neck segments, first, second and third proximal segments, collecting segments and collecting ducts. The glomerular endothelial cells are fenestrated showing a thin diaphragm. Mesangial cells are located around and between the capillaries, suggesting a role in vessel contraction; they show no phagocytic ultrastructural features. An extensive part of the podocyte surface lies flat on the glomerular basement membrane; this characteristic is probably related to the diminishing of the glomerular filtration rate. Podocytes show large multivesicular bodies, lysosomes and vesicles with a dense bar. Large globules in the podocytes point to their possible secretory activity. The first proximal segment is made up of principal cells with a well developed brush border and tightly packed basal infoldings, and scarce ciliated cells. The second proximal segment consists of principal cells, with loose-packed microvilli and numerous deep basal invaginations, ciliated cells and dark cells. The third proximal segment shows cells with irregularly arranged microvilli and a basal labyrinth, and some ciliated cell. The collecting segment and the collecting duct cells were characterized by apical mucous droplets; the latter also show a well developed basal labyrinth and are surrounded by a layer of smooth muscle cells.