Search Results (13)

Coral reefs are threatened by climate change, because it causes increasingly frequent and severe summer heatwaves, resulting in mass coral bleaching and mortality. Coral bleaching is believed to be driven by an excess production of reactive oxygen (ROS) and nitrogen species (RNS), yet their relative roles during thermal stress remain understudied. Here, we measured ROS and RNS net production, as well as activities of key enzymes involved in ROS scavenging (superoxide dismutase and catalase) and RNS synthesis (nitric oxide synthase) and linked these metrics to physiological measurements of cnidarian holobiont health during thermal stress. We did this for both an established cnidarian model, the sea anemone Exaiptasia diaphana, and an emerging scleractinian model, the coral Galaxea fascicularis, both from the Great Barrier Reef (GBR). Increased ROS production was observed during thermal stress in both species, but it was more apparent in G. fascicularis, which also showed higher levels of physiological stress. RNS did not change in thermally stressed G. fascicularis and decreased in E. diaphana. Our findings in combination with variable ROS levels in previous studies on GBR-sourced E. diaphana suggest G. fascicularis is a more suitable model to study the cellular mechanisms of coral bleaching. Full article

Food products often consist of several phases. Comminuted meat products, for example, are multiphase systems consisting of structured meat particles and unstructured batter-like substance. To develop and understand the processing of these products, it is important to understand the sensory and mechanical perception principles. To this end, two-phase food prototypes consisting of mixtures of ground beef and beef batter were prepared and subjected to sensory, texture, and oral processing analysis. The oral processing analysis focused on the biomechanical data of the chewing process, namely the kinematics of jaw movement and electromyographic activity. The ground meat served as the anisotropic phase and the meat dough as the isotropic phase. A significant increase in muscle activity, duration per bite, and occlusion time with increasing proportion of fibrous particles was demonstrated (p < 0.05). In contrast, a higher proportion of isotropic substance resulted in significantly higher amplitudes of jaw movement and faster jaw kinetics (p < 0.05). In mixed regimes, the system responded mainly according to the dominant phase, with sensory or mechanical response changing at a critical point. In combination with texture and sensory data, a holistic characterization of the food models could be performed. Full article

Dinoflagellates of the family Symbiodiniaceae are crucial photosymbionts in corals and other marine organisms. Of these, Cladocopium goreaui is one of the most dominant symbiont species in the Indo-Pacific. Here, we present an improved genome assembly of C. goreaui combining new long-read sequence data with previously generated short-read data. Incorporating new full-length transcripts to guide gene prediction, the C. goreaui genome (1.2 Gb) exhibits a high extent of completeness (82.4% based on BUSCO protein recovery) and better resolution of repetitive sequence regions; 45,322 gene models were predicted, and 327 putative, topologically associated domains of the chromosomes were identified. Comparison with other Symbiodiniaceae genomes revealed a prevalence of repeats and duplicated genes in C. goreaui, and lineage-specific genes indicating functional innovation. Incorporating 2,841,408 protein sequences from 96 taxonomically diverse eukaryotes and representative prokaryotes in a phylogenomic approach, we assessed the evolutionary history of C. goreaui genes. Of the 5246 phylogenetic trees inferred from homologous protein sets containing two or more phyla, 35–36% have putatively originated via horizontal gene transfer (HGT), predominantly (19–23%) via an ancestral Archaeplastida lineage implicated in the endosymbiotic origin of plastids: 10–11% are of green algal origin, including genes encoding photosynthetic functions. Our results demonstrate the utility of long-read sequence data in resolving structural features of a dinoflagellate genome, and highlight how genetic transfer has shaped genome evolution of a facultative symbiont, and more broadly of dinoflagellates. Full article

Background: Symptoms of anxiety are often unrecognized and untreated in dialysis patients. We investigated the diagnostic accuracy of two widely used screening tools for anxiety in hemodialysis patients. Methods: For this cross-sectional validation study, chronic hemodialysis patients from eight dialysis centers in the Netherlands were included. The Beck Anxiety Inventory (BAI) and Hospital Anxiety and Depression Scale—Anxiety subscale (HADS-A) were validated by the Mini International Neuropsychiatric Inventory (MINI) diagnostic interview. Receiver operating characteristic curves were used to determine the optimal cut-off values. Results: Of 65 participants, 13 (20%) were diagnosed with one or more anxiety disorders on the MINI, of which 5 were included in the analysis. ROC curves showed a good diagnostic accuracy of the BAI and HADS-A. The optimal cut-off value for the BAI was ≥13 (sensitivity 100%, specificity 85%) and for the HADS-A was ≥10 (sensitivity 80%, specificity 100%). Conclusions: Based on our limited data, both the BAI and the HADS-A seem to be valid screening instruments for anxiety in hemodialysis patients that can be used in routine dialysis care. The HADS-A consists of fewer items and showed fewer false-positive results than the BAI, which might make it more useful in clinical practice. Full article

Heat-tolerant strains of the coral endosymbiont, Cladocopium C1^acro (Symbiodiniaceae), have previously been developed via experimental evolution. Here, we examine physiological responses and bacterial community composition (using 16S rRNA gene metabarcoding) in cultures of 10 heat-evolved (SS) and 9 wild-type (WT) strains, which had been exposed for 6 years to 31 °C and 27 °C, respectively. We also examine whether the associated bacterial communities were affected by a three-week reciprocal transplantation to both temperatures. The SS strains had bacterial communities with lower diversities that showed more stability and lower variability when exposed to elevated temperatures compared with the WT strains. Amplicon sequence variants (ASVs) of the bacterial genera Labrenzia, Algiphilus, Hyphobacterium and Roseitalea were significantly more associated with the SS strains compared with the WT strains. WT strains showed higher abundance of ASVs assigned to the genera Fabibacter and Tropicimonas. We hypothesize that these compositional differences in associated bacterial communities between SS and WT strains also contribute to the thermal tolerance of the microalgae. Future research should explore functional potential between bacterial communities using metagenomics to unravel specific genomic adaptations. Full article

Corals are the main primary producers of coral reefs and build the three-dimensional reef structure that provides habitat to more than 25% of all marine eukaryotes. They harbor a complex consortium of microorganisms, including bacteria, archaea, fungi, viruses, and protists, which they rely on for their survival. The symbiosis between corals and bacteria is poorly studied, and their symbiotic relationships with intracellular bacteria are only just beginning to be acknowledged. In this review, we emphasize the importance of characterizing intracellular bacteria associated with corals and explore how successful approaches used to study such microorganisms in other systems could be adapted for research on corals. We propose a framework for the description, identification, and functional characterization of coral-associated intracellular bacterial symbionts. Finally, we highlight the possible value of intracellular bacteria in microbiome manipulation and mitigating coral bleaching. Full article

The popular yet demonic guardian of ancient Egypt, Bes, combines dwarfish and leonine features, and embodies opposing traits such as a fierce and gentle demeanor, a hideous and comical appearance, serious and humorous roles, an animalistic and numinous nature. Drawing connections with similarly stunted figures, great and small cats, sacred cows, baboons, demonic monsters, universal gods and infant deities, this article will focus on the animalistic associations of the Bes figure to illustrate that this leonine dwarf encompassed a wider religious significance than apotropaic and regenerative functions alone. Bes was thought to come from afar but was always close; the leonine dwarf guarded the sun god Ra along the diurnal solar circuit; the figure protected pregnant women and newborn children; it was a dancer and musician; the figure belonged to the company of magical monsters of hybrid appearance as averter of evil and sword-wielding fighter. Exploring the human and animal, demonic and numinous aspects of this leonine dwarf will not only further our understanding of its nature and function, but also its significance and popularity. Full article

This study investigates working alliance in blended cognitive behavioral therapy (bCBT) for depressed adults in specialized mental health care. Patients were randomly allocated to bCBT (n = 47) or face-to-face CBT (n = 45). After 10 weeks of treatment, both patients and therapists in the two groups rated the therapeutic alliance on the Working Alliance Inventory Short-Form Revised (WAI-SR; Task, Bond, Goal, and composite scores). No between-group differences were found in relation to either patient or therapist alliance ratings, which were high in both groups. In the full sample, a moderate positive association was found between patient and therapist ratings on Task (ρ = 0.41, 95% CI 0.20; 0.59), but no significant associations emerged on other components or composite scores. At 30 weeks, within-and between-group associations between alliance and changes in depression severity (QIDS, Quick Inventory of Depressive Symptomatology) were analyzed with linear mixed models. The analyses revealed an association between depression over time, patient-rated alliance, and group (p < 0.001). In face-to-face CBT, but not in bCBT, lower depression scores were associated with higher alliance ratings. The online component in bCBT may have led patients to evaluate the working alliance differently from patients receiving face-to-face CBT only. Full article

Coral bleaching linked to climate change has generated interest in the response of coral’s bacterial microbiome to thermal stress. The sea anemone, Exaiptasia diaphana, is a popular coral model, but the response of its bacteria to thermal stress has been barely explored. To address this, we compared the bacterial communities of Great Barrier Reef (GBR) E. diaphana maintained at 26 °C or exposed to increasing temperature (26–33 °C) over two weeks. Communities were analyzed by metabarcoding of the bacterial 16S rRNA gene. Bleaching and Symbiodiniaceae health were assessed by Symbiodiniaceae cell density and dark-adapted quantum yield (F_v/F_m), respectively. Significant bleaching and reductions in F_v/F_m occurred in the heat-treated anemones above 29 °C. Overall declines in bacterial alpha diversity in all anemones were also observed. Signs of bacterial change emerged above 31 °C. Some initial outcomes may have been influenced by relocation or starvation, but collectively, the bacterial community and taxa-level data suggested that heat was the primary driver of change above 32 °C. Six bacterial indicator species were identified as potential biomarkers for thermal stress. We conclude that the bacterial microbiome of GBR E. diaphana is generally stable until a thermal threshold is surpassed, after which significant changes occur. Full article

Elephants were first deployed in warfare by Indian and Persian armies. The Greco-Macedonian troops first encountered these fearsome creatures in battle during the campaign of Alexander the Great. Subsequently, the Successors and later Hellenistic rulers similarly used elephants in battle. From this time, the animal began to appear in Greco-Roman art. Tracing the appearance of the elephant in Hellenistic history and art, I suggest that the elephant not only continued to be associated with its Asian and African origins and came to symbolize military triumph over exotic foes, it retained religious and mythic proportions as a fearsome, fabulous monster connected with the martichora and unicorn, griffon and sphinx, dragon and hippocampus. In particular, I re-examined the posthumous portrait of Alexander the Great in which he wears an elephant scalp as a headdress, similar to Heracles’ lion scalp. This deified portraiture not only depicts Alexander as descendant of Heracles and Dionysus, both sons of Zeus, but also—through connections with Ammon and Indra—as the legitimate ruler of the three continents of the known world, Europe, Africa, and Asia. Full article

A mummy portrait of a young woman with a golden wreath is part of the archaeological collection of the Allard Pierson Museum in Amsterdam. This portrait is covered by four authors, each from their separate perspective, namely provenance research, technical examination, museum presentation, and diversity education. Provenance research is significant not only for tracing the second-life biography of the panel, but also for assessing its bona fide authenticity. Non-invasive examinations can help identify possible underlayers, pigments and modern restorations. Museological aspects concern the contextualization of the portrait, not only as a funerary artefact, but also as an expression of physical appearance. Educational programs can be implemented to illustrate to museum visitors the relevance of ancient artefacts for modern society. Full article

The quality of digital poetry or art—not merely as contained within our aesthetic reaction to digitally expressive works but as well our intellectual grounding in them—suggests that the digital’s seemingly ephemeral character is an indication of its lack of an apparently material existence. While, aesthetically, the digital’s ephemerality lies in the very fact of the digitally artistic enterprise, the fact is that its material substrate is what makes the aesthetic pleasure we take in it possible. When we realize for ourselves the role played by this substrate, furthermore, a paradox looms up before us. The fact is that we both enjoy, and in some sense separately understand the artwork comprehensively and fully; we also allow ourselves to enter into an ongoing conversation about the nature of the physical world. This conversation is not insignificant for the world of art especially, inasmuch as art depends upon the actual materials of the world—even digital art—and, too, upon our physical engagement with the art. Digital poetry and art, whose dynamic demands the dissolution of the line that would otherwise distinguish one from the other, have brought the notion of embodiment to the fore of our considerations of them, and here is the charm, along with the paradoxical strength, of digital art and poetry: it is our physical participation in them that makes them fully come into being. Full article

Adaptation of reef corals to climate change is an issue of much debate, and often viewed as too slow a process to be of relevance over decadal time scales. This notion is based on the long sexual generation times typical for some coral species. However, the importance of somatic mutations during asexual reproduction and growth on evolution and adaptation (i.e., cell lineage selection) is rarely considered. Here we review the existing literature on cell lineage selection and show that the scope for somatic mutations to arise in the coral animal and associated Symbiodinium is large. For example, we estimate that ~100 million somatic mutations can arise within a branching Acropora coral colony of average size. Similarly, the large population sizes and rapid turn-over times of in hospite Symbiodinium likely result in considerable numbers of somatic mutations. While the fate of new mutations depends on many factors, including ploidy level and force and direction of selection, we argue that they likely play a key role in the evolution of reef corals. Full article