Influence of aquaculture waste on fatty acid profiles and gonad maturation of wild fish aggregations at fish farms.

Wild fish belonging to four species belonging to different trophic groups were captured at three distances from fish farm facilities: long distance (>5 Km), medium distance (1.5 Km) and close to sea-cages. Flesh, brain, liver and gonads were sampled for fatty acid analysis. Fish aggregated near sea-cages showed accumulation of fatty acids of vegetable origin in the studied tissues, due to surplus feed consumption or via predation of fish that consumed the feed. Gonads accumulated vegetable fatty acids in different manner in the different species, and the species least and most influenced by fish-feeds were selected for gonad histological examination. Results showed an acceleration of the final stages of the oocyte development in fish aggregated near fish farms compared to fish captured at long distance. Differences in oocyte development were more acute in the species which incorporated higher quantities of vegetable fatty acids.

The short-term effects of farmed fish food consumed by wild fish congregating outside the farms.

We simulated in the laboratory the possible effects on fatty acids and immune status of wild fish arriving for the first time in the vicinity of a sea-cage fish farm, shifting their natural diet to commercial feed consumption, rich in fatty acids of vegetable origin. The flesh fatty acid profile of golden mullet specimens was altered after 2weeks of commercial feed consumption, showing an increase in fatty acids of vegetable origin. The serum peroxidase and bactericidal activities, and head-kidney leucocyte phagocytic capacity, increased after eight weeks of the new diet, while the respiratory burst activity decreased. The extent of these changes cannot be considered large enough to regard them as compromising the health status of fish. More research is needed in order to elucidate whether the rapid assimilation of the dietary fatty acids could harm the immune status of fish when feeding for longer periods than two months.

Mediterranean fouling communities assimilate the organic matter derived from coastal fish farms as a new trophic resource.

Currently, the lipid content of fish feeds includes high amounts of terrestrial vegetable oils, rich in n-6 fatty acids and poor in n-3 fatty acids. Sinking organic matter in the shape of fragmented pellets and fish faeces could be ingested by the surrounding fauna attracted to the submerged structures of aquaculture facilities or living in natural benthic habitats. Fatty acids contained in feed pellets were used as trophic markers to shed light on the assimilation and incorporation of aquaculture wastes by the invertebrate fauna associated to sea-cages. Eighteen macroinvertebrate species, and zooplankton, seaweeds and sediments were collected from two fish farms, one of which (control) had not been used as such for two years. This study demonstrates that macroinvertebrate fauna present in fouling can take up sinking organic matter from farms. Further research should be directed at assessing the potential implications of aquaculture production for the surrounding ecosystem.

Circadian rhythms of gene expression of lipid metabolism in Gilthead Sea bream liver: synchronisation to light and feeding time.

This research aimed at investigating circadian rhythm expression of key genes involved in lipid metabolism in the liver of a teleost fish (Sparus aurata), and their synchronisation to different light-dark (L-D) and feeding cycles. To this end, 90 gilthead sea bream were kept in 12:12 h (light:dark, LD, lights on at ZT0) and fed a single daily meal at mid-light (ML = ZT6), mid-darkness (MD = ZT18) and randomly (RD) at a 1.5% body weight ration. A total of 18 tanks were used, six tanks per feeding treatment with five fishes per tank; locomotor activity was recorded in each tank. After 25 days of synchronisation to these feeding regimes, fishes were fasted for one day and liver samples were taken every 4 hours during a 24 h cycle (ZT2, 6, 10, 14, 18 and 22) and stored at -80 °C until analysis. To determine whether the rhythm expression presented an endogenous control, another experiment was performed using 30 fish kept in complete darkness and fed randomly (DD/RD). Samples were taken following the same procedure as above. The results revealed that all genes investigated exhibited well defined daily rhythms. The lipolysis-related and fatty acid turnover genes (hormone-sensitive lipase (hsl) and peroxisome proliferator-activated receptor-α (pparα)) exhibited a nocturnal achrophase (Ø = ZT18:03-19:21); lipoprotein lipase (lpl) also showed the same nocturnal achrophase (Ø = ZT20:04-21:36). In contrast, lipogenesis-related gene, fatty acid synthase (fas), and of fatty acid turnover, cyclooxygenase (cox-2), showed a diurnal rhythm (Ø = ZT2:27-8:09); while pparγ was nocturnal (Ø = ZT16:16-18:05). Curiously, feeding time had little influence on the phase of these daily rhythms, since all feeding groups displayed similar achrophases. Furthermore, under constant conditions pparα and hsl showed circadian rhythmicity. These findings suggest that lipid utilisation in the liver is rhythmic and strongly synchronised to the LD cycle, regardless of feeding time, which should be taken into consideration when investigating fish nutrition and the design of feeding protocols.

Midriasis congénita como signo inicial de displasia septo-óptica / Congenital mydriasis as an initial sign of septo-optic dysplasia

La displasia septo-óptica (DSO)[MIM182230] es una entidad heterogénea poco frecuente, caracterizada por la tríada clásica: hipoplasia del nervio óptico, anomalías de las hormonas hipofisarias y defectos de la línea media cerebral (incluyendo agenesia del septumpellucidumy/o del cuerpo calloso; también se han descrito malformaciones corticales asociadas, citado como síndrome DSO plus). Referimos el primer caso clínico conocido, en el que el signo de diagnóstico inicial de DSO fue una midriasis bilateral, como manifestación de hipoplasia de ambos nervios ópticos, hipoplasia hipofisaria y disgenesia cerebral con alteración de migración neuronal. Discutimos el diagnóstico diferencial de la midriasis congénita (AU)

Septo-optic dysplasia (SOD)[MIM182230] consisting of a heterogeneous and uncommon condition characterised by the classic triad: optic nerve hypoplasia, abnormalities of pituitary hormone, and defects of the brain midline (including agenesis of the septum pellucidum and/or the corpus callosum; it has also been described associated cortical malformations, it was referred to as SOD plus syndrome).We report the first known case in which the initial diagnostic sign of SOD was a bilateral mydriasis as a manifestation of hypoplasia of both optic nerves, pituitary hypoplasia andcerebral dysgenesis with neuronal migration disorder. We discuss the differential diagnosis of congenital mydriasis (AU)

[Congenital mydriasis as an initial sign of septo-optic dysplasia]. / Midriasis congénita como signo inicial de displasia septo-óptica.

Septo-optic dysplasia (SOD)[MIM182230] consisting of a heterogeneous and uncommon condition characterised by the classictriad: optic nerve hypoplasia, abnormalities of pituitary hormone, and defects of thebrain midline (including agenesis of the septum pellucidum and/or the corpus callosum; ithas also been described associated cortical malformations, it was referred to as SOD plus syndrome).We report the first known case in which the initial diagnostic sign of SOD was a bilateralmydriasis as a manifestation ofhypoplasia of both optic nerves, pituitary hypoplasia andcerebral dysgenesis with neuronal migration disorder.We discuss thedifferential diagnosis of congenital mydriasis.

Two-dimensional colloidal aggregation mediated by the range of repulsive interactions.

We study the effect of the interaction's range on the structural and kinetic properties of a computer-simulated two-dimensional aggregating colloidal system. For this purpose, we considered that the particles of the system interact through a repulsive Yukawa potential which depends on two parameters: the value of the interaction potential between particles in contact V0 and the range of the interaction kappa(d) . We observed that the increase of the interaction range or V0 provokes the arrangement of the small aggregates in linear structures. The repulsive interactions have also a strong influence on the kinetic behavior of the coagulation process. Indeed, they induce the formation of three different time-separated aggregation regimes. In the first regime (at early states) the aggregation is dominated by the range of the repulsive forces, and the cluster-cluster repulsion increases with the cluster size. The second regime (at intermediate times) is reached when the average cluster size is larger than the interaction range. Here, the cluster-cluster repulsions do not grow anymore with the cluster size, so the probability of overcoming the repulsive barrier is the same for all clusters. This corresponds with the so-called reaction-limited-cluster-aggregation regime, where more than one collision between the clusters is needed to form a bond. The third aggregation regime is found at long aggregation times. In this region the coagulation is mainly determined by the diffusion time and the kinetics becomes diffusion controlled. A physical interpretation for the transition between chain structures and the typical fractals aggregates from the point of view of the range of the interactions is discussed. Moreover, a method has been developed in order to obtain the effect of the interactions with a non-negligible range over the aggregation rates directly from the simulations. The relation between these different regions with the parameters of the interaction potential V0 and kappa(d) is analyzed.

La gestión de riesgos en Atención Primaria: estudio de la morbilidad / Management of risks in Primary Health Care: morbidity study

OBJETIVO. Identificar en las reclamaciones económicas en Atención Primaria, a través de los diagnósticos clínicos, el análisis de las causas, la intensidad del daño ocasionado y las medidas que se pueden adoptar para evitar su repetición. MATERIAL Y MÉTODOS. Es un estudio observacional, descriptivo y transversal, que analiza la morbilidad que ha dado origen a las reclamaciones económicas (443 en Atención Primaria) presentadas contra el Insalud en el período 1995-2001, utilizando la CIE-9 modificada. RESULTADOS. En la distribución de las reclamaciones por grupos diagnósticos, el de traumatismos es el más numeroso, con el 26,40% del total de casos, seguido por problemas cardiovasculares (19,40%), tumores (10,60%) y problemas nerviosos y respiratorios (7,70% y 6,50%). El error diagnóstico es el motivo más frecuente de reclamación (62,75%); el resultado de muerte se produjo en el 40,60% del total de sucesos reclamados. El mayor número de fallecimientos (87,20%) se produce en las reclamaciones por problemas cardiovasculares; le siguen tumores (46,80%), aparato respiratorio (65,50%) y traumatismos (15,40%). El síndrome coronario agudo representa el 65% de los siniestros de su grupo, valorándose como práctica clínica inadecuada la observada en 36 de los casos de infarto agudo de miocardio (IAM). En los otros grupos, los porcentajes de práctica clínica inadecuada fueron: traumatismos el 58,20%, tumores el 32%, aparato respiratorio el 34,5%, aparato genitourinario el 54,5%. Organización o dotación incorrecta se encontró en el 70% de los accidentes en centros de salud. CONCLUSIONES. Los porcentajes de práctica clínica inadecuada detectados en las reclamaciones ponen de relieve la necesidad de mejorar la práctica clínica en Atención Primaria, para lo que es conveniente implantar la metodología de la gestión de riesgos clínicos

OBJECTIVE. Identify the analysis of the causes, intensity of harm caused and measures that can be adopted to avoid its repetition in the economic claims in Primary Health Care through the clinical diagnoses. MATERIAL AND METHODS. This is an observational, descriptive, cross-sectional study that analyzes morbidity that has given rise to the economic claims (443 in Primary Health Care) presented against the Spanish Public Health System in the period 1995-2001, using the modified ICD-9. RESULTS. In the distribution of the claims per diagnostic groups, traumas are the most numerous, with 26.40% of all the cases, followed by cardiovascular problems (19.40%), tumors (10.60%) and nervous and respiratory problems (7.70% and 6.50%). Diagnostic error is the most frequent reason for the claim (62.75%); the result of death occurred in 40.60% of all the events with claims. The greatest number of deaths (87.20%) occurs in claims due to cardiovascular problem; followed by tumors (46.80%), respiratory tract (65.50%) and traumas (15.40%). Acute coronary syndrome represents 65% of the damage of its group, that observed in 36 of the cases of AMF being assessed as inadequate clinical practice. In the other groups, the percentages of inadequate clinical practice were: trauma 58.20%, tumors 32%, respiratory tract 34.5%, genitourinary tract 54.5%. Incorrect organization or resources were found in 70% of the accidents in health care centers. CONCLUSIONS. The percentage of inadequate clinical practice detected in the claims manifests the need to improve the clinical practice in Primary Health Care. Thus, it is convenient to introduce the clinical risk management methodology

Short- and long-range topological correlations in two-dimensional aggregation of dense colloidal suspensions.

We have studied the average properties and the topological correlations of computer-simulated two-dimensional (2D) aggregating systems at different initial surface packing fractions. For this purpose, the centers of mass of the growing clusters have been used to build the Voronoi diagram, where each cell represents a single cluster. The number of sides (n) and the area (A) of the cells are related to the size of the clusters and the number of nearest neighbors, respectively. We have focused our paper in the study of the topological quantities derived from number of sides, n , and we leave for a future work the study of the dependence of these magnitudes on the area of the cells, A . In this work, we go beyond the adjacent cluster correlations and explore the organization of the whole system of clusters by dividing the space in concentric layers around each cluster: the shell structure. This method allows us to analyze the time behavior of the long-range intercluster correlations induced by the aggregation process. We observed that kinetic and topological properties are intimately connected. Particularly, we found a continuous ordering of the shell structure from the earlier stages of the aggregation process, where clusters positions approach a hexagonal distribution in the plane. For long aggregation times, when the dynamic scaling regime is achieved, the short- and long-range topological properties reached a final stationary state. This ordering is stronger for high particle densities. Comparison between simulation and theoretical data points out the fact that 2D colloidal aggregation in the absence of interactions (diffusion-limited cluster aggregation regimen) is only able to produce short-range cluster-cluster correlations. Moreover, we showed that the correlation between adjacent clusters verifies the Aboav-Weaire law, while all the topological properties for nonadjacent clusters are mainly determined by only two parameters: the second central moment of number-of-sides distribution mu(2) = sumP (n) (n-6)(2) and the screening factor a (defined through the Aboav-Weaire equation). We also found that the values of mu(2) and a calculated for two-dimensional aggregating system are related through a single universal common form a proportional to mu2(-0.89), which is independent of the particle concentration.

Gestión de riesgos en Atención Primaria: casos pediátricos / Risk management in Primary Care: paediatric cases

Objetivo: valorar la seguridad de la asistencia a la población infantil, analizando los expedientesde responsabilidad patrimonial del extinguido Insalud.Material y métodos: estudio observacional, descriptivo y transversal; se analizaron los56 expedientes con edad pediátrica por un grupo de trabajo con amplia experiencia profesionalen Atención Primaria. El análisis estadístico se realizó con los programas SPSS versión11 y S-PLUS versión 6.0.Resultados: los casos pediátricos constituyen el 12,64% del total (443) de reclamacionesen Atención Primaria del período analizado (1995-2001); la edad media fue de 4,81años, siendo los varones el 57,15%. En el 53,57% de los expedientes no había documentaciónclínica o ésta era de calidad inaceptable. Se habían originado secuelas orgánicas o funcionalesen el 53,57% de las reclamaciones y el fallecimiento en el 23,21% de los casos.Había error diagnóstico en el 64,30% de los casos y una posible praxis inadecuada en el35,71% (37% en el estudio global). Aplicando la CIE-9, los grupos XVII (28,57%), VI(10,71%), VIII (8,92%), X (8,92%) y XVI (8,92%) son los prevalentes.Conclusiones: el análisis de casos pediátricos proporciona mejores resultados que losdel total en Atención Primaria. La mayoría de las reclamaciones se fundan en supuestoserrores médicos. En las áreas rurales, atendidas por médicos generales, existe un mayor riesgode praxis inadecuada. La implantación de programas de gestión de riesgos ayudará a mejorarla calidad y la seguridad de los pacientes

Objective: To assess the safety of health care to patients in paediatric age, analysing thepatrimonial responsibility dossiers against the extinguished Insalud.Material and methods: An observational, descriptive, transversal study; it were analysedall 56 dossiers in paediatric age by a work team with a large professional experience in Primary settings was conformed. A technical document with proceedings and clinical specificjudgement was accorded. The statistic analysis was made with the SPSS version 11 andS-Plus version 6.0 programs.Results: The paediatric cases accounted for 12.64% of total (443) of claims in primarycare in the analysed period (1995-2001); the average age of 4.81 years, being the males57.15%.In 53.57% of administrative dossiers there had not clinical records or its quality wasnot acceptable. Physical or organic sequelae were present in 53.75%; and death in 23.21%.Diagnostic error was identified in 64.30% of claims, and probable medical malpractice in35.71% of cases (37% in global study). According with CIE-9, groups XVII (28, 57%), VI(10.71%), VIII (8.92%),X (8.92%) and XVI (8.92%) were prevalent.Conclusions: The pediatric cases analysis give better results than that we found in theoverall number in primary care. The majority of claims are based on alleged medical errors.The rural areas deserved by general practitioners, present an increased risk of medical malpractice.When the attendant physician was paediatrician the minor percentage of malapraxiswas found. To implement specific programmes of risk healthcare management will helpto increase the quality and safety of patients

Spontaneous formation of mesostructures in colloidal monolayers trapped at the air-water interface: a simple explanation.

The spontaneous formation of loosely bound ordered aggregates, foam, voids, chains, striations, and loops (see Figure 1a), called mesostructures hereafter, has been observed in colloidal monolayers trapped at the air-water interface. The distance between particles in these mesostructures is of the order of the particle radius (micrometers), implying that the colloidal interaction potential has a minimum at such distances, which could induce the phase separation of colloidal monolayers in dense and dilute regions. This is at odds with the accepted theory (Derjaguin-Landau-Verwey-Overbeek (DLVO)) of colloidal interactions, which predicts a secondary minimum at distances of nanometers between pairs of interacting particles. Moreover, the introduction of capillary, hydrophobic, and dipolar interactions between particles in an extended DLVO theory is not able to explain the spontaneous formation of mesostructures either. Recently, a great deal of effort has focused on understanding the mechanism behind the phenomenon of long-range attraction between colloidal particles confined in interfaces. In particular, this attraction has been employed to explain the spontaneous formation of mesostructures. Here, we show that the appearance of our mesostructures is due to the contamination of colloidal monolayers by silicone oil (poly(dimethylsiloxane)), which arises from the coating of the needles and syringes used to deposit and spread the particle solution at the air-water interface. The difference in the interfacial tension of water and silicone oil accounts for the formation of the experimentally observed mesostructures.

The effect of the salt concentration and counterion valence on the aggregation of latex particles at the air/water interface.

An experimental study on colloidal aggregation in two dimensions is presented. This study shows that a high amount of electrolyte concentration is necessary to screen the particle interactions and to induce the aggregation process. Our results indicate that the stability of the colloidal particles, with a diameter of 735 nm, increases when they are trapped at the air-water interface. The reason for this stability is the existence of long-range repulsive interactions between the external parts of the particles that are propagated at the air phase. The subphase electrolyte concentration that separates the slow aggregation rate region from the fast aggregation rate region, the critical coagulation concentration (C.C.C.), has been determined for counterions with a different valence. Two regimes can be distinguished: at low salt concentration the aggregation process becomes slower and the aggregation is reaction limited. At high ionic strength the repulsive interactions between the immersed part of the particles are very weak and the aggregation rate tends to grow. However, because of the aerial repulsive interactions, pure diffusion-limited cluster aggregation is never found.

A Light Scattering Study of the Transition Region between Diffusion- and Reaction-Limited Cluster Aggregation.

Two limiting regimes for colloidal particle aggregation are well described in the literature: diffusion-limited cluster aggregation and reaction-limited cluster aggregation. Between these two limiting regimes, a vast transition region is expected. In this paper, the transition region is studied by means of static and dynamic light scattering. Therefore, a system of latex particles is aggregated at different electrolyte concentrations. The time dependence of the average diffusion coefficient is fitted considering the Brownian kernel and the kernel proposed by Schmitt et al. [Phys. Rev. E 62, 8335 (2000)]. The first fits the experimental data only at high electrolyte concentrations while the latter, which considers multiple cluster-cluster contacts, is found to fit the complete set of experimental data. Copyright 2001 Academic Press.

Colloidal Interaction at the Air-Liquid Interface.

In this paper, we propose a model to analyze the stability of colloidal particles at the air-liquid interface. The proposed model for the colloidal particle interaction considers DLVO interactions and capillary, hydrophobic, and dipolar interactions between the particles. Typical values from the literature were assigned to most parameters included in the model. Numerical computation revealed the most important parameter in determining the total interaction is the density of dipoles at the external surface of the particles. We have found significant differences for the pair potential between hydrophobic and hydrophilic particles. Hydrophobic particles must aggregate in a principal minimum of the interaction potential curve while hydrophilic particles aggregate in a secondary minimum. Copyright 2000 Academic Press.

Controlled release of carbofuran from an alginate-bentonite formulation: water release kinetics and soil mobility.

The insecticide-nematicide carbofuran was incorporated in alginate-based granules to obtain controlled-release (CR) properties. The basic formulation [sodium alginate (1.61%)-carbofuran (0. 59%)-water] was modified by addition of sorbents. The effect on carbofuran release rate, caused by the incorporation of natural and acid-treated bentonite (0.5 and 1.0 M H(2)SO(4)) in alginate formulation, was studied by immersion of the granules in water under shaking. The time taken for 50% of the active ingredient to be released into water, t(50), was longer for those formulations containing natural bentonite (6.1 h) or acid-treated bentonite (9.0 and 11.7 h for 0.5 and 1.0 M H(2)SO(4) treatments, respectively) than for the preparation without bentonite (4.7 h). It appears from the results that the release of carbofuran from the various formulations is controlled by a diffusion mechanism according to the n values obtained, which were close to 0.5 in all cases. The mobility of carbofuran from alginate-based CR formulations was investigated by using soil columns packed with a clay soil (53% clay and 0.08% organic matter). Two alginate-based CR formulations containing natural bentonite or acid-treated bentonite (0.5 M H(2)SO(4)) were compared to technical grade carbofuran. The use of alginate-based CR formulations resulted in a reduction of the leached amount of carbofuran compared with the total amount of pesticide leached using the technical product (50 and 75% for CR granules containing natural and acid-treated bentonite, respectively). Alginate-bentonite CR formulations might be efficient systems for reducing carbofuran leaching in clay soils, which would reduce the risk of groundwater pollution.