Key plant species and detritivores drive diversity effects on instream leaf litter decomposition more than functional diversity: A microcosm study.

Anthropogenic impacts on freshwater ecosystems cause critical losses of biodiversity that can in turn impair key processes such as decomposition and nutrient cycling. Forest streams are mainly subsidized by terrestrial organic detritus, so their functioning and conservation status can be altered by changes in forest biodiversity and composition, particularly if these changes involve the replacement of functional groups or the loss of key species. We examined this issue using a microcosm experiment where we manipulated plant functional diversity (FD) (monocultures and low-FD and high-FD mixtures, resulting from different combinations of deciduous and evergreen Quercus species) and the presence of a key species (Alnus glutinosa), all in presence and absence of detritivores, and assessed effects on litter decomposition, nutrient cycling, and fungal and detritivore biomass. We found (i) positive diversity effects on detritivore-mediated decomposition, litter nutrient losses and detritivore biomass exclusively when A. glutinosa was present; and (ii) negative effects on the same processes when microbially mediated and on fungal biomass. Most positive trends could be explained by the higher litter palatability and litter trait variability obtained with the inclusion of alder leaves in the mixture. Our results support the hypothesis of a consistent slowing down of the decomposition process as a result of plant biodiversity loss, and hence effects on stream ecosystem functioning, especially when a key (N-fixing) species is lost; and underscore the importance of detritivores as drivers of plant diversity effects in the studied ecosystem processes.

Severe Trombiculiasis in Hunting Dogs Infested With Neotrombicula inopinata (Acari: Trombiculidae).

This study records the clinical findings in nine hunting dogs showing systemic illness associated with trombiculids and identifies the mite species involved. In fall, coinciding with the seasonality of mites, all dogs were infested with mites and had been in the risk area (Sierra Cebollera Natural Park, La Rioja, Spain) a few hours before the onset of symptoms. The symptoms included vomiting, anorexia, weakness and lethargy, diarrhea, and even stupor. The clinical picture was fast-acting and potentially fatal. The infestations varied from low to severe. Molecular analysis of mites that fed on the dogs confirmed that they were larvae of Neotrombicula inopinata (Oudemans, Acari, Trombiculidae). This is the first time that N. inopinata has been identified as feeding on dogs and implicated in canine systemic illness associated with trombiculids. In contrast to other chiggers, N. inopinata does not seem to cause dermatitis. Likewise, the clinical and epidemiological similarity between the clinical symptoms we describe herein and the occurrence of seasonal canine illness (SCI) led us to suspect that this illness may be caused by infestation with these mites. The condition could be the consequence of severe infestation from large numbers of feeding mites, especially N. inopinata. Whether or not the cases were due to a severe allergic host response to salivary proteins or the result of the transmission of a new or emerging trombiculid-borne pathogen is not known.

Pleuropulmonary involvement in patients with systemic lupus erythematosus from a Latin American inception cohort (GLADEL).

Objectives The objectives of this study were to examine the demographic and clinical features associated with the occurrence of pleuropulmonary manifestations, the predictive factors of their occurrence and their impact on mortality in systemic lupus erythematosus (SLE) patients. Materials and methods The association of pleuropulmonary manifestations with demographic and clinical features, the predictive factors of their occurrence and their impact on mortality were examined in GLADEL patients by appropriate univariable and multivariable analyses. Results At least one pleuropulmonary manifestation occurred in 421 of the 1480 SLE patients (28.4%), pleurisy being the most frequent (24.0%). Age at SLE onset ≥30 years (OR 1.42; 95% CI 1.10-1.83), the presence of lower respiratory tract infection (OR 3.19; 95% CI 2.05-4.96), non-ischemic heart disease (OR 3.17; 95% CI 2.41-4.18), ischemic heart disease (OR 3.39; 95% CI 2.08-5.54), systemic (OR 2.00; 95% CI 1.37-2.91), ocular (OR 1.58; 95% CI 1.16-2.14) and renal manifestations (OR 1.44; 95% CI 1.09-1.83) were associated with pleuropulmonary manifestations, whereas cutaneous manifestations were negatively associated (OR 0.47; 95% CI 0.29-0.76). Non-ischemic heart disease (HR 2.24; 95% CI 1.63-3.09), SDI scores ≥1 (OR 1.54; 95% CI 1.10-2.17) and anti-La antibody positivity (OR 2.51; 95% CI 1.39-4.57) independently predicted their subsequent occurrence. Cutaneous manifestations were protective of the subsequent occurrence of pleuropulmonary manifestations (HR 0.62; 95% CI 0.43-0.90). Pleuropulmonary manifestations independently contributed a decreased survival (HR: 2.79 95% CI 1.80-4.31). Conclusion Pleuropulmonary manifestations are frequent in SLE, particularly pleuritis. Older age, respiratory tract infection, cardiac, systemic and renal involvement were associated with them, whereas cutaneous manifestations were negatively associated. Cardiac compromise, SDI scores ≥1 and anti-La positivity at disease onset were predictive of their subsequent occurrence, whereas cutaneous manifestations were protective. They independently contributed to a decreased survival in these patients.

Early discoid lupus erythematosus protects against renal disease in patients with systemic lupus erythematosus: longitudinal data from a large Latin American cohort.

OBJECTIVES: The objective of this study was to examine whether early discoid lupus erythematosus (DLE) would be a protective factor for further lupus nephritis in patients with systemic lupus erythematosus (SLE). METHODS: We studied SLE patients from GLADEL, an inception longitudinal cohort from nine Latin American countries. The main predictor was DLE onset, which was defined as physician-documented DLE at SLE diagnosis. The outcome was time from the diagnosis of SLE to new lupus nephritis. Univariate and multivariate survival analyses were conducted to examine the association of DLE onset with time to lupus nephritis. RESULTS: Among 845 GLADEL patients, 204 (24.1%) developed lupus nephritis after SLE diagnosis. Of them, 10 (4.9%) had DLE onset, compared to 83 (12.9%) in the group of 641 patients that remained free of lupus nephritis (hazard ratio 0.39; P = 0.0033). The cumulative proportion of lupus nephritis at 1 and 5 years since SLE diagnosis was 6% and 14%, respectively, in the DLE onset group, compared to 14% and 29% in those without DLE (P = 0.0023). DLE onset was independently associated with a lower risk of lupus nephritis, after controlling for sociodemographic factors and disease severity at diagnosis (hazard ratio 0.38; 95% confidence interval 0.20-0.71). CONCLUSIONS: Our data indicate that DLE onset reduces the risk of further lupus nephritis in patients with SLE, independently of other factors such as age, ethnicity, disease activity, and organ damage. These findings have relevant prognosis implications for SLE patients and their clinicians. Further studies are warranted to unravel the biological and environmental pathways associated with the protective role of DLE against renal disease in patients with SLE.

Colloidal stability of a temperature-sensitive poly(N-isopropylacrylamide/2-acrylamido-2-methylpropanesulphonic acid) microgel.

In this work, a study of the thermally induced flocculation of poly(N-isopropylacrylamide/2-acrylamido-2-methylpropanesulphonic acid) microgel, that is, poly(NIPAM/aMPS) microgel samples is presented. The aggregation process is monitored in continuous by dynamic light scattering measurements. Theoretical explanations are considered and discussed in terms of interaction potentials, paying special attention to osmotic and elastic contributions due to particle interpenetration. The rate of aggregation is studied as a function of temperature, and theoretical calculations of kinetic constants based on model core-shell particle interactions provide very good agreement with experimental results. The reversibility of aggregation is also analyzed. It is found that aggregation is completely reversible only under certain conditions: the temperature of an aggregated sample must decrease under 20 degrees C. These results are experimental evidence of the secondary minimum in the interaction potential where aggregation occurs.

Electrokinetic Characterization of Poly(N-isopropylacrylamide) Microgel Particles: Effect of Electrolyte Concentration and Temperature.

A fundamental study about the characterization of a poly(N-isopropylacrylamide), poly(NIPAM), microgel, cross-linked with N,N'-methylene bisacrylamide (BA), has been carried out. The anionic charge of this system was increased by copolymerization with 2-acrylamido-2methylpropanesulphonic (AMPS) acid. The electrokinetic behavior of these aMPS/NIPAM microgel particles has been investigated. First, the surface charge density was determined by conductimetric titration, and the particle size was obtained by transmission electron microscopy under several conditions. Electrophoretic mobility measurements were carried out as a function of electrolyte concentration and temperature. The hydrodynamic diameter of the particles was also measured by photon correlation spectroscopy as a function of electrolyte concentration and temperature. These size data have been taken into account in order to explain the mobility behavior by using Ohshima's theory for soft particles, with very good agreement between experiments and theoretical predictions. Copyright 2001 Academic Press.

Riparian vegetation and water chemistry in a basin under semiarid mediterranean climate, andarax river, Spain.

A study has been made of the relationships between the characteristics of the riparian vegetation (floristic composition, structure and diversity) and the spatial-temporal variation of the quality of the stream waters in a basin under a semiarid Mediterranean climate in the southeastern Iberian Peninsula. The plant communities of the high reaches present greater specific richness and diversity (S mean= 7.0 ± 3.4 and H'mean= 2.0 ± 0.7) than do those of the middle and low reaches (S mean= 4.5 ± 1.6 and H'mean= 1.8 ± 0.6). One zone reached the highest specific richness (S= 12, H'= 3.2), which, apart from being situated in the intermediate stretch of the basin, represents a transitional state (ecotone) between the Salix and Tamarix communities. The characteristics of the waters analyzed indicate very high rates of erosion and runoff due to the nature of the soils (easily eroded marls) and to agricultural expansion and mining since the 16th century. The present-day riparian vegetation is not adequate to absorb the nitrates added to the basin by crop fertilization, reaching extremely high values, particularly during the dry period (between 1.2 and 42.5 mg/liter). Sewage dumping at three sampling stations did not appear to affect the specific composition of the woody vegetation. In the zones with watercourses, water salinity was low during the period of greater water flow, but considerably higher in the dry season (the upper limit was some 1.2 mS/m), resulting in a predominance of salt cedars over willows. Three types of saltcedar areas were distinguished: subhalophilous, which barely changes its chemical composition over the season; halophilous, which develops over strongly mineralized waters and markedly alters in chemical composition during the dry season; and hyperhalophilous, where salinity is extraordinarily high and quite constant throughout the year. A direct relationship was found between the dominance of Tamarix africana and abundance of NaCl.

Efficacy of orally administered invermectin against larval stages of Oestrus ovis in sheep.

The efficacy of ivermectin administered orally at a dosage rate of 0.2 mg/kg liveweight against naturally acquired larval infestations of Oestrus ovis in sheep was 100% in a field trial. Ten sheep were free from infestation by first, second and third instar larvae of O. ovis 12 days post treatment, whereas 10 control sheep harboured 37.7 larvae on average, most of them first stage.

Short report: one case of nasal human myiasis caused by third stage instar larvae of Oestrus ovis.

This is a report of a case of human nasal myiasis caused by third instar larvae of the sheep nasal bot fly, Oestrus ovis. Female flies rarely deposit first instar larvae in the eye, nostrils, and external auditory canal of humans, where they usually survive only a few days without further development. One human infestation by third instar larvae of O. ovis has been recorded in an patient infected with human immunodeficiency virus (HIV) in the United Kingdom. Our report describes a new case of nasal myiasis caused by the third instar larvae of the sheep bot fly in a patient without HIV or signs of any other disease.

Canine myiasis by sheep bot fly (Diptera:Oestridae).

We present a case of canine infestation by 3rd instars of Oestrus ovis (L.) in a 10-yr-old cross-bred dog (Collie x German Shepherd) from Fuerteventura, Canary Islands, Spain. This report confirms that this fly can develop in dogs.

[Influence of the nature of the ingested blood on the gonotrophic parameters of Phlebotomus perniciosus under laboratory conditions]. / Influence de la nature du sang ingéré sur les paramètres gonotrophiques de Phlebotomus perniciosus sous conditions de laboratoire.

A laboratory study was conducted about the duration of developmental stages and the productivity connected with the type of blood meal ingested by the female of Phlebotomus perniciosus. The pre-oviposition and egg incubation periods are not affected whatever the blood ingested by the female. The shorter time required to achieve larval development (rabbit) and pupal development (hamster) governs the generation time, shorter than in the other hosts (dog and man). The productivity is greater when blood is ingested from the rabbit and the dog. This is mainly due to the smaller number of eggs retained in females with these hosts.