First insights into the impacts of benthic cyanobacterial mats on fish herbivory functions on a nearshore coral reef

Benthic cyanobacterial mats (BCMs) are becoming increasingly common on coral reefs. In Fiji, blooms generally occur in nearshore areas during warm months but some are starting to prevail through cold months. Many fundamental knowledge gaps about BCM proliferation remain, including their composition and how they influence reef processes. This study examined a seasonal BCM bloom occurring in a 17-year-old no-take inshore reef area in Fiji. Surveys quantified the coverage of various BCM-types and estimated the biomass of key herbivorous fish functional groups. Using remote video observations, we compared fish herbivory (bite rates) on substrate covered primarily by BCMs (> 50%) to substrate lacking BCMs (< 10%) and looked for indications of fish (opportunistically) consuming BCMs. Samples of different BCM-types were analysed by microscopy and next-generation amplicon sequencing (16S rRNA). In total, BCMs covered 51 ± 4% (mean ± s.e.m) of the benthos. Herbivorous fish biomass was relatively high (212 ± 36 kg/ha) with good representation across functional groups. Bite rates were significantly reduced on BCM-dominated substratum, and no fish were unambiguously observed consuming BCMs. Seven different BCM-types were identified, with most containing a complex consortium of cyanobacteria. These results provide insight into BCM composition and impacts on inshore Pacific reefs

CONSCIÊNCIA NA SUBSTITUIÇÃO DO USO DE ANIMAIS NO ENSINO: ASPECTOS HISTÓRICOS, ÉTICOS E DE LEGISLAÇÃO

o especismo, a discriminação de direitos em favor da espéciehumana e em detrimento de outras espécies, é praticado também noambiente acadêmico. O uso indiscriminado de animais não-humanospara o ensino e a pesquisa é uma prática antiga, que foi consolidadadurante a Idade Moderna. Mesmo diante da tecnologia atual, osanimais ainda são usados, de forma prejudicial, para a demonstraçãode conhecimentos. Como reação de um número crescente depesquisadores em todas as áreas do conhecimento, tem havido umaumento da criação, aperfeiçoamento e consolidação de métodossubstitutivos e, por parte dos estudantes, a objeção de consciência.Assim, a substituição do uso prejudicial de animais por métodosmais eficazes é uma realidade possível e positiva no desenvolvimento ético dos humanos pelo refinamento do respeito aos não-humanos, possibilitando o desenvolviment de habilidades necessárias à prática profissional

Sensitivity of phytoplankton, zooplankton and macroinvertebrates to hydrogen peroxide treatments of cyanobacterial blooms

Addition of hydrogen peroxide (H2O2) is a promising method to acutely suppress cyanobacterial blooms in lakes. However, a reliable H2O2 risk assessment to identify potential effects on non-target species is currently hampered by a lack of appropriate ecotoxicity data. The aim of the present study was therefore to quantify the responses of a wide diversity of freshwater phytoplankton, zooplankton and macroinvertebrates to H2O2 treatments of cyanobacterial blooms. To this end, we applied a multifaceted approach. First, we investigated the 24-h toxicity of H2O2 to three cyanobacteria (Planktothrix agardhii, Microcystis aeruginosa, Anabaena sp.) and 23 non-target species (six green algae, eight zooplankton and nine macroinvertebrate taxa), using EC50 values based on photosynthetic yield for phytoplankton and LC50 values based on mortality for the other organisms. The most sensitive species included all three cyanobacterial taxa, but also the rotifer Brachionus calyciflores and the cladocerans Ceriodaphnia dubia and Daphnia pulex. Next, the EC50 and LC50 values obtained from the laboratory toxicity tests were used to construct a species sensitivity distribution (SSD) for H2O2. Finally, the species predicted to be at risk by the SSD were compared with the responses of phytoplankton, zooplankton and macroinvertebrates to two whole-lake treatments with H2O2. The predictions of the laboratory-based SSD matched well with the responses of the different taxa to H2O2 in the lake. The first lake treatment, with a relatively low H2O2 concentration and short residence time, successfully suppressed cyanobacteria without major effects on non-target species. The second lake treatment had a higher H2O2 concentration with a longer residence time, which resulted in partial suppression of cyanobacteria, but also in a major collapse of rotifers and decreased abundance of small cladocerans. Our results thus revealed a trade-off between the successful suppression of cyanobacteria at the expense of adverse effects on part of the zooplankton community. This delicate balance strongly depends on the applied H2O2 dosage and may affect the decision whether to treat a lake or not.</p

Lipiodol injection for target volume delineation and image guidance during radiotherapy for bladder cancer.

A technique was developed for bladder tumour demarcation with lipiodol injection through a flexible cystoscope. The technique proved to be simple and useful for image-guided radiotherapy in bladder cancer as well as a helpful aid in the tumour delineation proces

Evaluation of tumor shape variability in head-and-neck cancer patients over the course of radiation therapy using implanted gold markers.

Purpose: This study quantifies tumor shape variability in head-and-neck cancer patients during radiation therapy using implanted markers. Methods and Materials: Twenty-seven patients with oropharyngeal tumors treated with (chemo) radiation were included. Helical gold markers (0.35 x 2 mm, 3-10/patient, average 6) were implanted around the tumor. Markers were identified on planning computed tomography (CT) and daily cone beam CT (CBCT). After bony anatomy registration, the daily vector length on CBCT in reference to the planning CT and daily marker movement perpendicular to the gross tumor volume (GTV) surface at planning CT (d(normal)) of each marker were analyzed. Time trends were assessed with linear regression of the <d(normal)>(markers). In 2 patients, 2 markers were implanted in normal tissue to evaluate migration by measuring intermarker distances. Results: Marker implantation was feasible without complications. Three-dimensional vectors (4827 measurements, mean 0.23 cm, interquartile ratio 0.24 cm) were highest in base of tongue sublocalization (P <.001) and bulky tumors (vectors exceeded 0.5 cm in 5.7% [0-20 mL], 12.0% [21-40 mL], and 21.7% [>= 41 mL], respectively [P <.001] of measurements). The measured inward time trend in 11/27 patients correlated with the visual observed marker pattern. In patients with an outward trend (5/27) or no trend (11/27), visual observation showed predominantly an inhomogeneous pattern. Remarkably, in 6 patients, outward marker movement was observed in the posterior pharyngeal wall. The difference in distance between normal tissue markers (1 SD) was 0.05-0.06 cm without time trend, indicating that implanted markers did not migrate. Conclusions: During head-and-neck radiation therapy, normal tissue markers remained stable. Changes in position of tumor markers depended on sublocalization and tumor volume. Large differences in marker patterns between patients as well as within patients were observed. Based on our study, the cranial and caudal border in the posterior pharyngeal wall are at highest risk to be covered insufficiently. Furthermore, implanted markers could help identify patients with an actual shrinkage of the GTV who might benefit from mid-radiation therapy redelineation to reduce toxicity. (C) 2012 Elsevier In

PANOPTES: Een nieuw hulpmiddel voor MBB'ers om kritieke organen te leren intekenen ten behoeve van radiotherapie planning

Een nauwkeurige intekening van de tumor en omliggende kritieke organen is essentieel voor radiotherapie om een zo goed mogelijk behandelresultaat te verkrijgen. Het intekenen van kritieke organen is echter gevoelig voor inter- en intra-observervariatie. Eerder onderzoek heeft uitgewezen dat de kwaliteit van intekenen van kritieke organen door MBRT studenten verbetering behoeft, maar dat hulpmiddelen hiervoor niet voorhanden zijn. In het Panoptes project is een web-based hulpmiddel voor het onderwijs ontwikkeld en getest om het intekenonderwijs te verbeteren. Het project is uitgevoerd door het Lectoraat Medische Technologie van de Hogeschool Inholland in samenwerking met de Universiteit van Manchester en het Amsterdam UMC (locatie AMC). De ontwikkelde tool is, na evaluatie, geïmplementeerd in het curriculum van de opleiding Medisch Beeldvormende en Radiotherapeutische Technieken in Haarlem