First report on proliferative kidney disease (PKD) in marble trout (Salmo trutta marmoratus, Cuvier 1817)

Proliferative kidney disease is a hyperplastic response of the principal lymphoid tissue of salmonid fish infected by Tetracapsidoides bryosalmonae, a myxozoan parasite. This parasite affects many rainbow trout farms in Europe and North America. The disease has also been reported in other salmonids as well as in pike (Esox lucius) and grayling (Thymallus thymallus). In autumn 2000, an outbreak of PKD induced mortality in a group of marble trout (Salmo trutta marmoratus) juveniles reared in a farm in north-east Italy. The fish were intended to restock public waters. Diseased fish showed a lethargic behaviour, skin darkening, abdominal dilatation, gill anaemia and, after necroscopy, increase in volume and a pale colour of the kidney. All fishes subjected to histological examination showed a marked granulomatous interstitial nephritis, as well as foci of pancreatic and hepatic necrosis. The immunohistochemistry and PAS stain allowed visualisation of the extrasporogonic phase of the parasite Tetracapsuloides bryosalmonae in several tissues of the host. This is the first reported outbreak of PKD in marble trout, and should receive full attention since this species is potentially under risk of extinction

Building intersubjectivity in blended problem-solving tasks

This paper aims to shed light on the process of building intersubjectivity between student-student dyads in a blended educational context. Three girls and five boys, 17 to 18 years old, participated in two types of problem-solving tasks. They formed four dyads and were required to negotiate aloud what to post in a web-forum. Dyads were video recorded, with eight sessions in total. The same pairs participated in both tasks. We are interested in understanding how the intersubjective processes were affected by the tasks and by the dyads. The two tasks differ concerning the structure of the problems. The first task was based on two short papers – one pro and other con – referring to a problem close to students' real life: the use of digital devices in class. The second problem was based on perspective-taking: dyads were required to imagine “How would the school of the future look in 20 years.” Data were analysed through a purpose-built codebook, comprising five macro-categories and 21 subcategories. Altogether, our results indicate an effect of both the type of task and of dyads' specific style of interaction. Nevertheless, a five-step process featuring intersubjectivity was found. Practical implications for teachers and educators are highlighted

Comparative Therapeutic Effects of Natural Compounds Against Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae)

The fish parasites Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae) cause important losses in freshwater and marine aquaculture industry, respectively. The possible adverse effects of compounds used to control these parasites in aquaculture resulted in increased interest on the search for natural products with antiparasitic activity. In this work, eighteen plant-derived compounds (2′,4′-Dihydroxychalcone; 7-Hydroxyflavone; Artemisinin; Camphor (1R); Diallyl sulfide; Esculetin; Eucalyptol; Garlicin 80%; Harmalol hydrochloride dihydrate; Palmatine chloride; Piperine; Plumbagin; Resveratrol; Rosmarinic acid; Sclareolide; Tomatine, Umbelliferone, and Usnic Acid) have been tested in vitro. Sixteen of these were used to determine their effects on the gill cell line G1B (ATCC®CRL-2536™) and on the motility of viable dinospores of Amyloodinium ocellatum, and thirteen were screened for inhibitory activity against Saprolegnia spp. The cytotoxicity results on G1B cells determined that only two compounds (2′,4′-Dihydroxychalcone and Tomatine) exhibited dose-dependent toxic effects. The highest surveyed concentrations (0.1 and 0.01 mM) reduced cell viability by 80%. Upon lowering the compound concentration the percentage of dead cells was lower than 20%. The same two compounds revealed to be potential antiparasitics by reducing in a dose-dependent manner the motility of A. ocellatum dinospores up to 100%. With respect to Saprolegnia, a Minimum Inhibitory Concentration was found for Tomatine (0.1 mM), Piperine and Plumbagin (0.25 mM), while 2′,4′-Dihydroxychalcone considerably slowed down mycelial growth for 24 h at a concentration of 0.1 mM. Therefore, this research allowed to identify two compounds, Tomatine and 2′,4′-Dihydroxychalcone, effective against both parasites. These compounds could represent promising candidates for the treatment of amyloodiniosis and saprolegniosis in aquaculture. Nevertheless, further in vitro and in vivo tests are required in order to determine concentrations that are effective against the considered pathogens but at the same time safe for hosts, environment and consumers

Transcriptome analysis of amyloodinium ocellatum tomonts revealed basic information on the major potential virulence factors

The ectoparasite protozoan Amyloodinium ocellatum (AO) is the etiological agent of amyloodiniosis in European seabass (Dicentrarchus labrax) (ESB). There is a lack of information about basic molecular data on AO biology and its interaction with the host. Therefore, de novo transcriptome sequencing of AO tomonts was performed. AO trophonts were detached from infested ESB gills, and quickly becoming early tomonts were purified by Percoll\uae density gradient. Tomont total RNA was processed and quality was assessed immediately. cDNA libraries were constructed using TruSeq\uae Stranded mRNA kit and sequenced using Illumina sequencer. CLC assembly was used to generate the Transcriptome assembly of AO tomonts. Out of 48,188 contigs, 56.12% belong to dinophyceae wherein Symbiodinium microadriaticum had 94.61% similarity among dinophyceae. Functional annotations of contigs indicated that 12,677 had associated GO term, 9005 with KEGG term. The contigs belonging to dinophyceae resulted in the detection of several peptidases. A BLAST search for known virulent factors from the virulence database resulted in hits to Rab proteins, AP120, Ribosomal phosphoprotein, Heat-shock protein70, Casein kinases, Plasmepsin IV, and Brucipain. Hsp70 and casein kinase II alpha were characterized in-silico. Altogether, these results provide a reference database in understanding AO molecular biology, aiding to the development of novel diagnostics and future vaccines

Rhabdomyosarcoma of Soft Tissues in an Adult Brook Trout (Salvelinus fontinalis)

This report describes a spontaneously arising rhabdomyosarcoma of soft tissues in a brook trout (Salvelinus fontinalis). The lesion was examined by means of histology, immunohistochemistry (IHC) and transmission electron microscopy (TEM). The cross-reactivity of the primary antibodies used in the IHC was investigated in silico using the Protein Blast system. Microscopically, the lesion appeared as a 'small round cell' undifferentiated sarcoma with rare myotube formation. IHC identified expression of sarcomeric actin and vimentin and these molecules showed the highest protein sequence identity. Lower protein sequence identity coincided with negative immunolabelling for desmin, MyoD1, myogenin and CD3. TEM revealed myofibrils, but without a defined sarcomeric architecture. The diagnosis of solid alveolar rhabdomyosarcoma of soft tissues was achieved on the basis of histological and ultrastructural finding

Identificação de áreas no estado de São Paulo vulneráveis à contaminação de água subterrânea.

RESUMO: Os solos atuam como um filtro natural e influem na vulnerabilidade de corpos de água subterrânea à contaminação por agrotóxicos e outras substâncias químicas orgânicas. Com o objetivo de caracterizar a vulnerabilidade da água subterrânea à contaminação no estado de São Paulo, em base territorial e escala exploratória, esse trabalho foi elaborado utilizando o índice TR, propriedades médias dos solos e dados de recarga hídrica líquida anual. Foi possível identificar áreas nas diferentes categorias de vulnerabilidade com base no índice TR, destacando-se áreas vulneráveis na região centro-nordeste do estado, onde ocorrem importantes atividades agrícolas. Também foi possível a identificação das classes de solos predominantes nas áreas com maior vulnerabilidade das águas subterrâneas à contaminação.CONBEA 2021. Evento on-line

Identificação remota de cenários críticos para contaminação de água subterrânea em áreas agrícolas.

Para verificar as condições realísticas para contaminação de água subterrânea em áreas agrícolas e contribuir para maior consistência nos processos decisórios na avaliação de riscos ambientais, um método inovador de identificação remota de cenários críticos, utilizando dados geoespaciais, é apresentado e aplicado

Estudo in vitro da eficácia dos extratos de Nim (Azadirachta indica) contendo concentrações conhecidas de azadiractina A contra fêmeas de Rhipicephalus microplus.

O carrapato Rhipicephalus microplus é considerado o principal parasita de bovinos, gerando grandes prejuízos à pecuária brasileira. O uso intensivo de acaricidas para o seu controle, gerou um grave problema de resistência nestes parasitas aos princípios químicos usados. A utilização de extratos de plantas tropicais surgiu recentemente, como uma alternativa ao controle químico. Os extratos de Azadirachta indica conhecidos popularmente como Nim, são amplamente usados no controle destes parasitas. No entanto, poucos estudos foram desenvolvidos para testar soluções com a principal substância ativa quantificada. Assim este estudo foi desenvolvido para investigar a ação ?in vitro? de extratos de sementes desta planta, quantificadas por HPLC, sobre fêmeas de Rhipicephalus microplus

(Z)-N,N-Dimethyl-2-[phen­yl(pyridin-2-yl)methyl­idene]hydrazinecarbothio­amide

The title compound, C15H16N4S, exists in the Z conformation with the thionyl S atom lying cis to the azomethine N atom. The shortening of the N—N distance [1.3697 (17) Å] is due to extensive delocalization with the pyridine ring. The hydrazine–carbothio­amide unit is almost planar, with a maximum deviation of 0.013 (2) Å for the amide N atom. The stability of this conformation is favoured by the formation of an intra­molecular N—H⋯N hydrogen bond. The packing of the mol­ecules involves no classical inter­molecular hydrogen-bonding inter­actions; however, a C—H⋯π inter­action occurs