Chemosensory grazing by marine calanoid copepods (arthropoda: crustacea)

In laboratory experiments, mixed populations of two marine copepods (Acartia clausi and Eurytemora herdmani) when fed artificial food particles consisting of microcapsules that were either enriched with an encapsulated homogenate of naturally occurring phytoplankton or nonenriched preferentially ingested the enriched capsules. Beads or nonenriched capsules were either seldom ingested or not ingested at all. The observations demonstrate that filter-feeding in these species is a behavioral process, under sensory control, and that the copepods are able to discriminate between enriched and nonenriched food particles.     

Cytologic diagnosis of Lawsonia intracellularis proliferative ileitis in a Japanese snow macaque (Macaca fuscata)

Diffuse ileal thickening and ileocecocolic lymphadenomegaly were observed during exploratory laparotomy in a 2-year-old male Japanese snow macaque (Macaca fuscata) that had flu-like signs and diarrhea. Cytologic examination of ileal biopsy imprints revealed many mature, mildly karyolytic neutrophils and fewer well-differentiated lymphocytes, eosinophils, macrophages, and plasma cells in a background containing amorphous, necrotic material. Tightly cohesive sheets of moderately pleomorphic epithelial cells also were seen. The cytologic diagnosis was chronic, active, mixed inflammation with atypical epithelial cells and necrosis. Histologically, the mucosal and crypt epithelium was moderately hyperplastic with a loss of goblet cells, increased mitoses, and frequent crypt abscesses. Within the lamina propria and extending into the submucosa was a marked neutrophilic infiltrate, with low numbers of lymphocytes, histiocytes, plasma cells, and eosinophils. The histologic diagnosis was chronic, diffuse, marked suppurative and lymphocytic ileitis. Warthin-Starry silver staining of the ileal biopsy and imprint specimens demonstrated numerous pleomorphic, curved bacilli consistent with Lawsonia intracellularis. Polymerase chain reaction (PCR) and immunohistochemistry confirmed the identity of the infectious agent. L intracellularis infection may be underdiagnosed because silver stain is required to visualize the organism with light microscopy and because the pathognomonic crypt hyperplasia may be complicated by secondary pathologic changes. Application of silver stain to cytologic specimens should be considered when distal intestinal lesions associated with hyperplastic epithelium, with or without inflammation, hemorrhage, or necrosis, are identified in animals with clinical signs of enteritis, especially in frequently affected species or in stressed or young animals.     

Effects of grinding and thermal treatments on hydrolysis susceptibility of pea proteins (Pisum sativum L.)

The effects of three particle sizes with two types of grindings and two thermal treatments on pea protein extraction (PE) and susceptibility to in vitro enzymatic hydrolysis (pepsin plus trypsin) were studied. Degrees of hydrolysis (DH) were calculated. Remaining peptides were detected by SDS-PAGE and identified by immunoblotting and MS/MS spectrometry. The increase in particle size decreased PE and DH due to a restricted access of solvents and enzymes to proteins. The thermal treatment induced a decrease in PE but did not modify DH. Heating improved legumin (alphaM) and convicilin pepsin hydrolyses but reduced the pea albumin 2 (PA2) hydrolysis. After pepsin and trypsin hydrolysis, only peptides from vicilin and lectin were identified by LC-MS/MS analyses, whatever the treatment.     

Toxicity and tolerance of aluminium in vascular plants

Elevated levels of Al in soil solution may be toxic to plants. The activity of monomeric inorganic Al species is the best measure of the phytotoxic fraction. Decreasing soil pH increases soil solution Al exponentially as the pH falls below 4.5. In the presence of organic matter and organic acids the availability of A1 is reduced, due to complexation. The Al concentration is also dependent on dominant clay mineral and clay content. Symptoms of Al toxicity usually first appear in the roots becoming structurally and functionally damaged and inefficient in absorbing water and nutrients. This might be due to disturbance of mitosis and changed permeability of the root membranes. Aluminium also affects DNA replication, protein synthesis, and activity of some enzymes. Symptoms on shoots usually develop at a later stage of Al poisoning. There is an antagonism between the macronutrients P, Ca, Mg, and K on the one hand, and Al on the other. Aluminium may induce deficiency of mineral nutrients and high nutrient concentrations reduce al toxicity. There is considerable variation in Al tolerance between species and between varieties of the same species. Several mechanisms for Al tolerance are suggested. Tolerant plants may possess an active exclusion mechanism or may be able to inactivate Al within their tissues. pH increases induced by the plant in the rhizosphere, exudation of chelating agents, a low C.E.C. in the roots and an ability to withstand or compensate Al induced nutrient deficiency are other possible tolerance mechanisms.     

Pythiosis in a dromedary camel (Camelus dromedarius).

A 4.5-yr-old male dromedary camel (Camelus dromedarius) was evaluated for a mass on the right side of the face. A complete blood count and blood chemistry revealed anemia and hypoproteinemia. Radiographs did not reveal bony involvement. The mass was resected and Pythium insidiosum was cultured. The camel was treated with an experimental immunotherapeutic vaccine and with sodium iodide and ceftiofur. The camel began to lose weight postoperatively and died 6 mo later. At necropsy, the camel was found to have gastritis of the third compartment of the stomach with intralesional hyphae of this oomycete pathogen.     

Echoguided closed commissurotomy for mitral valve stenosis in a dog

Surgical treatment of mitral stenosis (MS) usually consists of open mitral commissurotomy (MC) or percutaneous balloon MC, which require a cardiopulmonary bypass or transseptal approach, respectively. We describe here the first surgical management of congenital MS in a dog using a less invasive procedure, a surgical closed MC under direct echo guidance. A 5-year-old female Cairn terrier was referred for ascites, weakness, and marked exercise intolerance for 2 months, which was refractory to medical treatment. Diagnosis of severe MS associated with atrial fibrillation (AF) was confirmed by echo-Doppler examination and electrocardiography. Poor response to medical treatment suggested a corrective procedure on the valve was indicated. However, due to the cost and high mortality rate associated with cardiopulmonary bypass, a hybrid MC was recommended. A standard left intercostal thoracotomy was performed and three balloon valvuloplasty catheters of differing diameters were sequentially inserted through the left atrium under direct echo guidance. Transesophageal echocardiography revealed a 62% reduction in the pressure half-time compared to the pre-procedure. Thirteen months after surgery the dog is still doing well with resolution of ascites and a marked improvement of most echo-Doppler variables.     

Continuous microalgal culture using swine manure dialysate as a nutrient source

Nutrients diffusing from swine manure through hollow-fibre dialysis improve the dry matter yield of the marine diatom Phaeodactylum tricornutum grown under natural light by 40% (72·6 versus 51·6 mg liter⁻¹ day⁻¹) compared to natural estuarine water. The increase is achieved despite incomplete nutrient removal and is ascribed to the higher concentrations of ammonia and orthophosphate supplied by swine manure dialysate. Growth promoting factors aside, the exclusion of predators and particles causing turbidity as well as the limited dialysis of heavy metals eliminate or greatly attenuate the growth retarding effects of such undersirable constituents of swine manure.     

GC-MS quantification of suspected volatile allergens in fragrances. 2. Data treatment strategies and method performances

The performances of the GC-MS determination of suspected allergens in fragrance concentrates have been investigated. The limit of quantification was experimentally determined (10 mg/L), and the variability was investigated for three different data treatment strategies: (1) two columns and three quantification ions; (2) two columns and one quantification ion; and (3) one column and three quantification ions. The first strategy best minimizes the risk of determination bias due to coelutions. This risk was evaluated by calculating the probability of coeluting a suspected allergen with perfume constituents exhibiting ions in common. For hydroxycitronellal, when using a two-column strategy, this may statistically occur more than once every 36 analyses for one ion or once every 144 analyses for three ions in common.     

Seasonal and spatial heterogeneities in host and vector abundances impact the spatiotemporal spread of bluetongue

Bluetongue (BT) can cause severe livestock losses and large direct and indirect costs for farmers. To propose targeted control strategies as alternative to massive vaccination, there is a need to better understand how BT virus spread in space and time according to local characteristics of host and vector populations. Our objective was to assess, using a modelling approach, how spatiotemporal heterogeneities in abundance and distribution of hosts and vectors impact the occurrence and amplitude of local and regional BT epidemics. We built a reaction–diffusion model accounting for the seasonality in vector abundance and the active dispersal of vectors. Because of the scale chosen, and movement restrictions imposed during epidemics, host movements and wind-induced passive vector movements were neglected. Four levels of complexity were addressed using a theoretical approach, from a homogeneous to a heterogeneous environment in abundance and distribution of hosts and vectors. These scenarios were illustrated using data on abundance and distribution of hosts and vectors in a real geographical area. We have shown that local epidemics can occur earlier and be larger in scale far from the primary case rather than close to it. Moreover, spatial heterogeneities in hosts and vectors delay the epidemic peak and decrease the infection prevalence. The results obtained on a real area confirmed those obtained on a theoretical domain. Although developed to represent BTV spatiotemporal spread, our model can be used to study other vector-borne diseases of animals with a local to regional spread by vector diffusion.