Abundance, size structure and community composition of phytoplankton in the Southern Ocean in the austral summer 1999/2000

The abundance, size structure and community composition of phytoplankton in the Southern Ocean were studied, using flow cytometry, microscopy and pigment profiles on two transects one latitudinal (N) and one longitudinal (W) during December 1999 and January 2000. In both transects, the concentration of autotrophic eukaryotes of 2-10μm equivalent spherical diameter (ESD) commonly exceeded those10μm ESD were detected by flow cytometry (however microscopy showed cells>10μm in length). Throughout transect N, chlorophyll α concentrations were generally. South of the Antarctic Polar Front (APF), chlorophyll α concentrations increased southward. CHEMTAX allocation of pigment data (italicized) showed that Diatoms contributed most chlorophyll with Haptophytes sub-dominant. North of the APF, chlorophyll α concentrations tended to increase northward. Here, Haptophytes contributed most chlorophyll, followed by Diatoms, Chlorophytes and Cyanobacteria, except at the northernmost stations where Cyanobacteria dominated. In transect W, chlorophyll α concentrations were also in most cases, but variable. Higher concentrations occasionally occurred in the west. In this transect, Diatoms contributed most (mean=61±15%) of the chlorophyll α, followed by Haptophytes. Nanodiatoms (particularly Fragilariopsis spp.) numerically dominated the diatom community. Fecal pellets composed of these nanodiatoms were observed in the Antarctic water, probably originating from heterotrophic dinoflagellates, implying a significant contribution of nanodiatoms to the microbial food web. However they contributed little to total chlorophyll α and diatom carbon biomass, particularly when chlorophyll and carbon concentrations were high

Role of Ventral Subiculum in Context-Induced Relapse to Alcohol Seeking after Punishment-Imposed Abstinence

In many human alcoholics, abstinence is self-imposed because of the negative consequences of excessive alcohol use, and relapse is often triggered by exposure to environmental contexts associated with prior alcohol drinking. We recently developed a rat model of this human condition in which we train alcohol-preferring P rats to self-administer alcohol in one context (A), punish the alcohol-reinforced responding in a different context (B), and then test for relapse to alcohol seeking in Contexts A and B without alcohol or shock. Here, we studied the role of projections to nucleus accumbens (NAc) shell from ventral subiculum (vSub), basolateral amygdala, paraventricular thalamus, and ventral medial prefrontal cortex in context-induced relapse after punishment-imposed abstinence. First, we measured double-labeling of the neuronal activity marker Fos with the retrograde tracer cholera toxin subunit B (injected in NAc shell) and demonstrated that context-induced relapse is associated with selective activation of the vSub→NAc shell projection. Next, we reversibly inactivated the vSub with GABA receptor agonists (muscimol+baclofen) before the context-induced relapse tests and provided evidence for a causal role of vSub in this relapse. Finally, we used a dual-virus approach to restrict expression of the inhibitory κ opioid-receptor based DREADD (KORD) in vSub→NAc shell projection neurons. We found that systemic injections of the KORD agonist salvinorin B, which selectively inhibits KORD-expressing neurons, decreased context-induced relapse to alcohol seeking. Our results demonstrate a critical role of vSub in context-induced relapse after punishment-imposed abstinence and further suggest a role of the vSub→NAc projection in this relapse. SIGNIFICANCE STATEMENT In many human alcoholics, abstinence is self-imposed because of the negative consequences of excessive use, and relapse is often triggered by exposure to environmental contexts associated with prior alcohol use. Until recently, an animal model of this human condition did not exist. We developed a rat model of this human condition in which we train alcohol-preferring P rats to self-administer alcohol in one context (A), punish the alcohol-reinforced responding in a different context (B), and test for relapse to alcohol seeking in Contexts A and B. Here, we used neuroanatomical, neuropharmacological, and chemogenetic methods to demonstrate a role of ventral subiculum and potentially its projections to nucleus accumbens in context-induced relapse after punishment-imposed abstinence

Global ubiquitinome profiling identifies NEDD4 as a regulator of Profilin 1 and actin remodelling in neural crest cells

The ubiquitin ligase NEDD4 promotes neural crest cell (NCC) survival and stem-cell like properties to regulate craniofacial and peripheral nervous system development. However, how ubiquitination and NEDD4 control NCC development remains unknown. Here we combine quantitative analysis of the proteome, transcriptome and ubiquitinome to identify key developmental signalling pathways that are regulated by NEDD4. We report 276 NEDD4 targets in NCCs and show that loss of NEDD4 leads to a pronounced global reduction in specific ubiquitin lysine linkages. We further show that NEDD4 contributes to the regulation of the NCC actin cytoskeleton by controlling ubiquitination and turnover of Profilin 1 to modulate filamentous actin polymerization. Taken together, our data provide insights into how NEDD4-mediated ubiquitination coordinates key regulatory processes during NCC development.Iman Lohraseb, Peter McCarthy, Genevieve Secker, Ceilidh Marchant, Jianmin Wu, Naveid Ali, Sharad Kumar, Roger J. Daly, Natasha L. Harvey, Hiroshi Kawabe, Oded Kleifeld, Sophie Wiszniak, Quenten Schwar

New technologies for examining neuronal ensembles in drug addiction and fear

Correlational data suggest that learned associations are encoded within neuronal ensembles. However, it has been difficult to prove that neuronal ensembles mediate learned behaviours because traditional pharmacological and lesion methods, and even newer cell type-specific methods, affect both activated and non-activated neurons. Additionally, previous studies on synaptic and molecular alterations induced by learning did not distinguish between behaviourally activated and non-activated neurons. Here, we describe three new approaches—Daun02 inactivation, FACS sorting of activated neurons and c-fos-GFP transgenic rats — that have been used to selectively target and study activated neuronal ensembles in models of conditioned drug effects and relapse. We also describe two new tools — c-fos-tTA mice and inactivation of CREB-overexpressing neurons — that have been used to study the role of neuronal ensembles in conditioned fear

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Canine Brachycephaly is Associated with a Retrotransposon-Mediated Missplicing of SMOC2

In morphological terms, “form” is used to describe an object’s shape and size. In dogs, facial form is stunningly diverse. Facial retrusion, the proximodistal shortening of the snout and widening of the hard palate is common to brachycephalic dogs and is a welfare concern, as the incidence of respiratory distress and ocular trauma observed in this class of dogs is highly correlated with their skull form. Progress to identify the molecular underpinnings of facial retrusion is limited to association of a missense mutation in BMP3 among small brachycephalic dogs. Here, we used morphometrics of skull isosurfaces derived from 374 pedigree and mixed-breed dogs to dissect the genetics of skull form. Through deconvolution of facial forms, we identified quantitative trait loci that are responsible for canine facial shapes and sizes. Our novel insights include recognition that the FGF4 retrogene insertion, previously associated with appendicular chondrodysplasia, also reduces neurocranium size. Focusing on facial shape, we resolved a quantitative trait locus on canine chromosome 1 to a 188-kb critical interval that encompasses SMOC2. An intronic, transposable element within SMOC2 promotes the utilization of cryptic splice sites, causing its incorporation into transcripts, and drastically reduces SMOC2 gene expression in brachycephalic dogs. SMOC2 disruption affects the facial skeleton in a dose-dependent manner. The size effects of the associated SMOC2 haplotype are profound, accounting for 36% of facial length variation in the dogs we tested. Our data bring new focus to SMOC2 by highlighting its clinical implications in both human and veterinary medicine

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

GRAZING RATE AND PARTICLE SIZE SELECTION BY THE CHOANOFLAGELLATE DIAPHANOECA GRANDIS FROM THE SEA-ICE OF LAGOON SAROMA KO, HOKKAIDO (Eleventh Symposium on Polar Biology)

Diaphanoeca grandis, a loricate choanoflagellate, is an abundant microheterotroph in many localities, including Antarctica. Little is known of its feeding selectivity or ingestion rates. In order to investigate the role of choanoflagellates in ice-covered marine environments, the grazing rates and particle size selection by D. grandis from the bottom-ice community of lagoon Saroma Ko were measured using fluorescent latex microspheres (FM). Maximum uptake rate was around 2FM-cell^・h^ and maximum clearance rate was 0.7 nl・cell^・h^. D. grandis was not able to ingest microspheres larger than 1 μm. These data are discussed in relation to their abundance, grazing rates by other protozoa and food availability in under-ice environments