Hydrodynamic Techniques for Fouling Control in Membrane Systems

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DNA barcoding of a stowaway reef coral in the international aquarium trade results in a new distribution record

Dead corals and limestone boulders that act as substrate for live specimens of marine invertebrates and algae are sold as ‘live rock’ in the international aquarium trade. During a customs inspection of an airfreight shipment of ‘live rock’ at Schiphol Airport (Netherlands), 450 boulders imported from Indonesia were checked for the presence of undeclared organisms. During unpacking, about 50% of the boulders appeared to have small stony corals attached to them. Some of these corals belonged to a species unknown from Indonesia. Mitochondrial COI and nuclear ITS markers revealed 100% and 99.3% match with Polycyathus chaishanensis Lin et al., 2012, a species reported from tidal pools in Taiwan. This new distribution record suggests that despite their easy access, intertidal and shallow subtidal reef coral assemblages (< 1 m depth) may still be underexplored

New Facility for Membrane Fouling Investigations under Customizable Hydrodynamics: Validation and Preliminary Experiments with Pulsating Cross-Flow

Flux reduction induced by fouling is arguably the most adverse phenomenon in membrane-based separation systems. In this respect, many laboratory-scale filtration studies have shown that an appropriate use of hydrodynamic perturbations can improve both performance and durability of the membrane; however, to fully understand and hence appropriately exploit such effects, it is necessary to understand the underpinning flow processes. Towards this end, in this work we propose and validate a new module-scale laboratory facility with the aim of investigating, at very well-controlled flow conditions, how hydrodynamics affects mass transport phenomena at the feed/membrane interface. The proposed facility was designed to obtain a fully developed and uniform flow inside the test section and to impose both steady and pulsating flow conditions. The walls of the facility were made transparent to grant optical accessibility to the flow. In this paper, we discuss data coming from particle image velocimetry (PIV) measurements and preliminary ultrafiltration tests both under steady and pulsating flow conditions. PIV data indicate that the proposed facility allows for excellent flow control from a purely hydrodynamic standpoint. Results from filtration tests provide promising results pointing towards pulsating flows as a viable technique to reduce fouling in membrane systems

Ondes et instabilités de fronts en milieu tournant et stratifié

Fronts occur in the Earth oceans and atmosphere and separate masses of air of fluid of different temperature and different velocities. Their instabilities are relevant to the transport of heat and energy in the oceans and atmosphere, and are therefore very relevant for climate modeling. In this study, a front is generated in the laboratory in a density stratified and differentially rotating fluid, and the corresponding flow is investigated numerically using DNS. In former studies of fronts, mainly the frontal instability has been discusses and baroclinic instability and newly found Rossby Kelvin instability were reported (Flor et al 2011, Scolan 2011, and Scolan et al 2013). The exact state of the interface is very relevant for the type of instability and waves we may expect. We therefore focus on the interfacial dynamics, and consider the diffusion of vorticity and density at an interface as a function of Rossby and Schmidt number. We note the existence of interfacial Ekman layers, observe Kelvin Helmholtz instability and discuss Hölmböe instability as well as other wave types near the interface

Monitoring of mental workload levels during an everyday life office-work scenario

Personal and ubiquitous healthcare applications offer new opportunities to prevent long-term health damage due to increased mental workload by continuously monitoring physiological signs related to prolonged high workload and providing just-in-time feedback. In order to achieve a quantification of mental load, different load levels that occur during a workday have to be discriminated. In this work, we present how mental workload levels in everyday life scenarios can be discriminated with data from a mobile ECG logger by incorporating individual calibration measures. We present an experiment design to induce three different levels of mental workload in calibration sessions and to monitor mental workload levels in everyday life scenarios of seven healthy male subjects. Besides the recording of ECG data, we collect subjective ratings of the perceived workload with the NASA Task Load Index (TLX), whereas objective measures are assessed by collecting salivary cortisol. According to the subjective ratings, we show that all participants perceived the induced load levels as intended from the experiment design. The heart rate variability (HRV) features under investigation can be classified into two distinct groups. Features in the first group, representing markers associated with parasympathetic nervous system activity, show a decrease in their values with increased workload. Features in the second group, representing markers associated with sympathetic nervous system activity or predominance, show an increase in their values with increased workload. We employ multiple regression analysis to model the relationship between relevant HRV features and the subjective ratings of NASA-TLX in order to predict the mental workload levels during office-work. The resulting predictions were correct for six out of the seven subjects. In addition, we compare the performance of three classification methods to identify the mental workload level during office-work. The best results were obtained with linear discriminant analysis (LDA) that yielded a correct classification for six out of the seven subjects. The k-nearest neighbor algorithm (k-NN) and the support vector machine (SVM) resulted in a correct classification of the mental workload level during office-work for five out of the seven subject

Portal vein thrombosis in patients on the waiting list for liver transplantation : a single center cohort study

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Morpho-molecular traits of Indo-Pacific and Caribbean <i>Halofolliculina </i>ciliate infections

Coral diseases are emerging as a major threat to coral reefs worldwide, and although many of them have been described, knowledge on their epizootiology is still limited. This is the case of the Halofolliculina ciliate infections, recognized as the skeletal eroding band (SEB) and Caribbean ciliate infection (CCI), two diseases caused by ciliates belonging to the genus Halofolliculina (Class Heterotrichea). Despite their similar macroscopic appearance, the two diseases are considered different and their pathogens have been hypothesized to belong to different Halofolliculina species. In this work, we analysed the morphology and genetic diversity of Halofolliculina ciliates collected in the Caribbean Sea, Red Sea and Indo-Pacific Ocean. Our analyses showed a strong macroscopic similarity of the lesions and similar settlement patterns of the halofolliculinids from the collection localities. In particular, the unique erosion patterns typical of the SEB were observed also in the Caribbean corals. Fine-scale morphological and morphometric examinations revealed a common phenotype in all analysed ciliates, unequivocally identified as Halofolliculina corallasia. Phylogenetic analyses based on nuclear and mitochondrial (COI) molecular markers consistently found all samples as monophyletic. However, although the nuclear marker displayed an extremely low intra-specific diversity, consistent with the morphological recognition of a single species, the analyses based on COI showed a certain level of divergence between samples from different localities. Genetic distances between localities fall within the intra-specific range found in other heterotrich ciliates, but they may also suggest the presence of a H. corallasia species complex. In conclusion, the presented morpho-molecular characterization of Halofolliculina reveals strong similarities between the pathogens causing SEB and CCI and call for further detailed studies about the distinction of these two coral diseases

Integrative systematics illuminates the relationships in two sponge-associated hydrozoan families (Capitata : Sphaerocorynidae and Zancleopsidae)

An integrated approach using morphological and genetic data is needed to disentangle taxonomic uncertainties affecting the hydrozoan families Sphaerocorynidae and Zancleopsidae. Here we used this approach to accurately characterise species in these families, identify the previously unknown polyp stages of the genera Euphysilla and Zancleopsis, which were originally described exclusively based on the medusa stages, describe a new sphaerocorynid genus and species, and assess the phylogenetic position of the two families within the Capitata. The monotypic genus Astrocoryne was found to be a synonym of Zancleopsis. Astrocoryne cabela was therefore transferred to the genus Zancleopsis as Zancleopsis cabela comb. nov. The new polyp-based genus and species Kudacoryne diaphana gen. nov. sp. nov. was erected within the Sphaerocorynidae. Both taxa are primarily based on genetic data, but the introduction of this new genus was made necessary by the fact that it clustered with the genera Heterocoryne and Euphysilla, despite showing Sphaerocoryne-like polyps. Interestingly, the species analysed in this work showed contrasting biogeographical patterns. Based on our data and literature records, some species appear to have a wide circumtropical range, whereas others are limited to few localities. Overall, these results lay the ground for future investigations aimed at resolving the taxonomy and systematics of these two enigmatic families.Peer reviewe

Diversity, host specificity and biogeography in the Cladocorynidae (Hydrozoa, Capitata), with description of a new genus

The hydrozoan family Cladocorynidae inhabits tropical to temperate waters and comprises the two genera Pteroclava and Cladocoryne. Pteroclava lives in association with some octocorals and hydrozoans, whereas Cladocoryne is more generalist in terms of substrate choice. This work provides a thorough morpho-molecular reassessment of the Cladocorynidae by presenting the first well-supported phylogeny of the family based on the analyses of three mitochondrial and four nuclear markers. Notably, the two nominal genera were confirmed to be monophyletic and both morphological and genetic data led to the formal description of a new genus exclusively associated with octocorals, Pseudozanclea gen. nov. Maggioni & Montano. Accordingly, the diagnosis of the family was updated. The ancestral state reconstruction of selected characters revealed that the symbiosis with octocorals likely appeared in the most recent common ancestor of Pteroclava and Pseudozanclea. Additionally, the presence of euryteles aggregation in the polyp stage and the exumbrellar nematocyst pouches with euryteles represent synapomorphies of all cladocorynid taxa and probably emerged in their most recent common ancestor. The analysis of several Pteroclava krempfi colonies from Indo-Pacific and Caribbean localities associated with several host octocorals revealed a high intra-specific genetic variability. Single- and multi-locus species delimitations resulted in three to five species hypotheses, but the statistical analysis of morphometric data showed only limited distinction among the clades of P. krempfi. However, P. krempfi clades showed differences in both host specificity, mostly at the octocoral family level, and geographic distribution, with one clade found exclusively in the Caribbean Sea and the others found in the Indo-Pacific.Fil: Maggioni, Davide. Università degli Studi di Milano; ItaliaFil: Garese, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Danwei Huang. National University Of Singapore; SingapurFil: Hoeksema, Bert W.. University of Groningen; Países BajosFil: Arrigoni, Roberto. Stazione Zoologica Anton Dohrn; ItaliaFil: Seveso, Davide. Università degli Studi di Milano; ItaliaFil: Galli, Paolo. Università degli Studi di Milano; ItaliaFil: Berumen, Michael L.. King Abdullah University of Science and Technology; Arabia SauditaFil: Montalbetti, Enrico. Università degli Studi di Milano; ItaliaFil: Pica, Daniela. Consorzio Nazionale Interuniversitario per le Scienze del Mare; ItaliaFil: Torsani, Fabrizio. Università Politecnica Delle Marche; ItaliaFil: Montano, Simone. Università degli Studi di Milano; Itali