There are significant challenges associated with mapping critical habitat for large, migratory species. The humpback whales of Oceania in the South Pacific are no exception, with their winter ...breeding grounds spanning >4000 km of ocean basin. This subpopulation is listed as endangered, but there are few systematic spatial data with which to prioritise specific areas for additional research or conservation. A few sites in Oceania have been the focus of long-term, non-systematic population surveys. Using the maximum entropy algorithm, we developed predictive habitat models for 2 such sites: American Samoa 2003–2010 (n = 300) and Tonga 1996–2007 (n = 475), using sightings of whale groups and environmental factors hypothesised to influence their space-use patterns. At both sites, shallow water was the best predictor of the spatial distribution of mother–calf pairs. In contrast, access to deep water was important for adult groups, and sea-floor slope and rugosity influenced habitat suitability for males engaged in acoustic breeding displays. Our study illustrates the value of predictive modelling for identifying habitat partitioning for specific sub-groups of a wider population. Similarities between habitat requirements predicted in our study to those identified for other populations suggest that the slow recovery of Oceania humpback whales cannot be attributed to unusual breeding-habitat needs; instead, there may be other factors influencing the slow increase in population size. We recommend that the modelling techniques utilised here be used to identify other breeding sites within Oceania for future research and conservation efforts across the South Pacific region.
Receptor organization and dynamics at the cell membrane are important factors of signal transduction regulation. Using super‐resolution microscopy and single‐particle tracking, we show how the ...negative coreceptor CD22 works with the cortical cytoskeleton in restraining BCR signalling. In naïve B cells, we found endogenous CD22 to be highly mobile and organized into nanodomains. The landscape of CD22 and its lateral diffusion were perturbed either in the absence of CD45 or when the CD22 lectin domain was mutated. To understand how a relatively low number of CD22 molecules can keep BCR signalling in check, we generated Brownian dynamic simulations and supported them with ex vivo experiments. This combined approach suggests that the inhibitory function of CD22 is influenced by its nanoscale organization and is ensured by its fast diffusion enabling a “global BCR surveillance” at the plasma membrane.
Synopsis
The inhibitory activity of CD22 on BCR signalling relies on its distribution into nanoclusters and high lateral mobility as shown by super‐resolution microscopy and in silico simulations. These properties are CD45 dependent and enable CD22 to efficiently scan the B‐cell membrane and, jointly with the actin cytoskeleton, restrain BCR signalling.
The alteration of the actin cytoskeleton activates both positive and negative signalling molecules similarly to BCR ligand‐dependent stimulation.
The inhibitory coreceptor CD22 is highly mobile and organized into nanodomains on the membrane of naïve B cells.
The binding of CD22 to sialic acid and CD45 controls CD22 mobility and organization at the plasma membrane.
CD22 organization and fast lateral mobility provide a means of restraining BCR tonic and ligand‐dependent signalling.
Super‐resolution microscopy and in silico simulations reveal efficient scanning of the B‐cell membrane as the basis for CD22's ability to keep BCR signalling in check.
We examine two positions, ON1 and ON2, within the Ophiuchus cloud LDN 1688 using observations made with the ISO photo-polarimeter (ISOPHOT) instrument aboard the Infrared Space Observatory (ISO) ...satellite. The data include mid-infrared spectra (∼6-12 μm) and several photometric bands up to 200 μm. The data probe the emission from molecular polycyclic aromatic hydrocarbon (PAH)-type species, transiently heated very small grains and large classical dust grains.
We compare the observations to earlier studies, especially those carried out towards an isolated translucent cloud in Chamaeleon (Paper I). The spectra towards the two LDN 1688 positions are very similar to each other in spite of position ON1 having a larger column density and probably being subjected to a stronger radiation field. The ratios of the mid-infrared features are similar to those found in other diffuse and translucent clouds. Compared to Paper I, the 7.7/11.3 μm band ratios are lower, ∼2.0, at both LDN 1688 positions. A continuum is detected in the ∼10 μm region. This is stronger towards the position ON1 but still lower than on any of the sightlines in Paper I. The far-infrared opacities are higher than in diffuse medium. The value of the position ON2, τ200/N(H) = 3.9 × 10− 25 cm2/H, is twice the value found for ON1.
The radiation field of LDN 1688 is dominated by the two embedded B-type double stars, ρ Oph AB and HD 147889, with an additional contribution from the Upper Sco OB association. The strong heating is reflected in the high colour temperature, ∼24 K, of the large grain emission. Radiative transfer modelling confirms a high level of the radiation field and points to an increased abundance of PAH grains. However, when the hardening of the radiation field caused by the local B stars is taken into account, the observations can be fitted with almost no change to the standard dust models. However, all the examined models underestimate the level of the mid-infrared continuum.
Several recent papers claim the detection of a near-infrared (NIR) extragalactic background light (EBL) intensity at 1.25-4 mum that exceeds the integrated light of galaxies by factors of >3. When ...combined with a claimed optical detection of the EBL at 0.80 mum the EBL excess emission spectrum has a discontinuity at ~1 mum. This discontinuity has given rise to an interpretation in terms of ultraviolet radiation emanating from the first generation of massive stars at redshifts of 7-20 (so-called Population III stars). The interpretation of the NIR excess emission as being of extragalactic origin depends crucially on the model used in the subtraction of the zodiacal light (ZL), the dominant foreground contaminant. We estimate the ZL at 0.80 mum using on the one hand the measurement by Bernstein et al., with corrections for some omitted effects of atmospheric scattering and calibration, and on the other hand the model of Kelsall et al. There is in neither case any evidence for a step in the EBL at ~1 mum. We emphasize that in order to avoid systematic effects it is essential to use the same ZL model for both the NIR (1.25-4 mum) and optical (0.80 mum) data. We emphasize, however, that our analysis does not allow a statement on the overall level of the NIR EBL. The contribution of the diffuse galactic light to the 'EBL excess' emission is estimated. It is found to be significant at 3-4 mum and should be carefully evaluated in future measurements which aim at detecting an EBL signal at the level of ~10 nW m-2 sr-1, that is, at the level of the integrated light of (known) galaxies. PUBLICATION ABSTRACT
We studied the prevalence of alexithymia, its distribution in different age groups in a wide age range, its association with sociodemographic and health-related variables, and its co-occurrence with ...depression.
The study forms part of the Health 2000 Study. The original sample comprised 8028 subjects representing the general adult population of Finland. Alexithymia was measured with the 20-item Toronto Alexithymia Scale (TAS-20), and depression was measured with the 21-item Beck Depression Inventory. Altogether, 5454 participants filled in TAS-20 in their mother tongue.
The prevalence of alexithymia was 9.9%. Men (11.9%) were more commonly alexithymic than women (8.1%). Alexithymia was associated with male gender, increasing age, low educational level, poor perceived health, and depression.
The findings were in line with earlier population studies. For the first time, it was possible to analyze the prevalence of alexithymia in a wide age range (30–97 years). International comparative studies are needed.
Radial glia play key roles in neuronal migration, axon guidance, and neurogenesis during development of the central nervous system. However, the molecular mechanisms regulating growth and morphology ...of these extended cells are unknown. We show that ABBA, a novel member of the IRSp53-MIM protein family, is enriched in different types of radial glia. ABBA binds ATP-actin monomers with high affinity and deforms PtdIns(4,5)P₂-rich membranes in vitro through its WH2 and IM domains, respectively. In radial-glia-like C6-R cells, ABBA localises to the interface between the actin cytoskeleton and plasma membrane, and its depletion by RNAi led to defects in lamellipodial dynamics and process extension. Together, this study identifies ABBA as a novel regulator of actin and plasma membrane dynamics in radial glial cells, and provides evidence that membrane binding and deformation activity is critical for the cellular functions of IRSp53-MIM-ABBA family proteins.
As birch pollen allergen enters epithelium of allergic patients via lipid rafts and caveola we began to analyse its putative amphiphilic and lipid ligands on atomic level using molecular modelling ...and computational ligand docking. We carry out 3D modelling docking with both experimentally verified Bet v 1 ligands as well as larger lipid molecules for which experimental affinity studies were not available. The results suggest that the hydrophobic cavity of Bet v 1 has different binding sites for different ligands and groups of ligand type-specific amino acids can be defined. Bet v 1 proteins may also be able to bind and transport more complex amphiphilic molecules like ceramides and sphingomyelins known to be enriched on caveolae/lipid rafts. Furthermore, the suggested binding mode, where the hydrophobic tail groups of lipids locate inside Bet v 1, while the polar head group may remain solvent accessible, would allow Bet v 1 to bind glycolipids, e.g. gangliosides, also rich on caveolae/lipid rafts. Taken together, this in silico work suggests that Bet v 1 bind to amphiphilic and lipid ligands present on the caveolae/lipid rafts and thus could provide a molecular mechanism for the pollen entry to epithelial tissue of allergic patients.
The endolysosomal system specializes in degrading cellular components and is crucial to maintaining homeostasis and adapting rapidly to metabolic and environmental cues. Cells of the immune system ...exploit this network to process antigens or promote cell death by secreting lysosome-related vesicles. In B lymphocytes, lysosomes are harnessed to facilitate the extraction of antigens and to promote their processing into peptides for presentation to T cells, critical steps to mount protective high-affinity antibody responses. Intriguingly, lysosomal vesicles are now considered important signaling units within cells and also display secretory functions by releasing their content to the extracellular space. In this review, we focus on how B cells use pathways involved in the intracellular trafficking, secretion, and function of endolysosomes to promote adaptive immune responses. A basic understanding of such mechanisms poses an interesting frontier for the development of therapeutic strategies in the context of cancer and autoimmune diseases.
Abstract Objective The aim of the present study was to assess the prevalence of alexithymia in a sample of general chronic pain patients, to explore possible differences in depression and pain ...variables between alexithymic and nonalexithymic chronic pain patients and to analyze if depression is a mediator between alexithymia and pain disability. Methods Two hundred and seventy-one patients making their first visit to a pain clinic completed the study questionnaire including various pain measures, the Beck Depression Inventory-II (BDI-II) and the 20-item Toronto Alexithymia Scale (TAS-20). The sample was dichotomized to alexithymic and nonalexithymic groups. The means of the study variables were compared between the groups. The correlation analysis of the variables was carried out separately in both groups. Path analysis was done to ascertain the mediation effect of BDI-II between the TAS-20 and pain disability. Results Every fifth chronic pain patient was alexithymic. The BDI-II and pain variable scores were significantly higher in the alexithymic group than in the nonalexithymic group. Pain variables were not associated with alexithymia when BDI-II was controlled for. BDI-II worked as a full mediator between TAS-20 and pain disability. Conclusion The alexithymic patient group was more morbid than the nonalexithymic group. The results suggest that depression is the main factor in pain conditions of alexithymic chronic pain patients. The authors recommend screening and treatment of depression in alexithymic chronic pain patients.
Abstract Objective The relationship between alexithymia and occupational burnout has not previously been studied. We investigated the association between alexithymia and occupational burnout in a ...representative nationwide population health study. Methods This study was a part of the Finnish Health 2000 Study. The nationally representative sample comprised 3322 employees aged 30–64 years. Alexithymia was measured with the 20-item Toronto Alexithymia Scale (TAS-20) and occupational burnout with the Maslach Burnout Inventory-General Survey. Sociodemographic and health-related variables including depression were treated as confounders in the logistic regression analyses, which were performed alternately with TAS-20 total score and the scores of the three TAS-20 factor scales as alexithymia variables. Results Alexithymia and its three facets were significantly associated with occupational burnout even when controlled for confounding factors. Conclusions Even though both alexithymia and depression are associated with burnout, alexithymia may be an independent risk factor for occupational burnout.
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