"Mind the trap": mindfulness practice reduces cognitive rigidity

Two experiments examined the relation between mindfulness practice and cognitive rigidity by using a variation of the Einstellung water jar task. Participants were required to use three hypothetical jars to obtain a specific amount of water. Initial problems were solvable by the same complex formula, but in later problems ("critical" or "trap" problems) solving was possible by an additional much simpler formula. A rigidity score was compiled through perseverance of the complex formula. In Experiment 1, experienced mindfulness meditators received significantly lower rigidity scores than non-meditators who had registered for their first meditation retreat. Similar results were obtained in randomized controlled Experiment 2 comparing non-meditators who underwent an eight meeting mindfulness program with a waiting list group. The authors conclude that mindfulness meditation reduces cognitive rigidity via the tendency to be "blinded" by experience. Results are discussed in light of the benefits of mindfulness practice regarding a reduced tendency to overlook novel and adaptive ways of responding due to past experience, both in and out of the clinical setting.     

Crustose coralline algae that promote coral larval settlement harbor distinct surface bacterial communities

Coral Reefs - Most benthic invertebrates, including ecosystem engineers such as corals, sponges and bivalves, have a motile planktonic larval phase and rely on specific chemical cues to identify a...     

Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans

The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.     

Vibrio sp. as a potentially important member of the Black Band Disease (BBD) consortium in Favia sp. corals

Black Band Disease (BBD) is a well-described disease plaguing corals worldwide. It has been established that ecological and environmental stress factors contribute to the appearance and progression of the disease, believed to be caused by a diverse microbial consortium. We have identified and characterized Vibrio sp. associated with BBD in Eilat reef corals using both culture-dependent and -independent methods. Direct sampling using 16S rRNA gene clone libraries showed seasonal dynamics in the diversity of BBD-associated Vibrios . In the two sampling periods, BBD-associated Vibrio clones showed similarities to different groups: October samples were similar to known pathogens, while December samples were similar to general aquatic Vibrio sp. Cultured bacterial isolates of Vibrio sp. were highly homologous (≥99%) to previously documented BBD-associated bacteria from the Caribbean, Bahamas and Red Seas, and were similar to several known coral pathogens, such as Vibrio coralliilyticus . The proteolytic activity of Vibrio sp., as measured using casein- and azocasein-based assays, directly correlated with temperature elevation and peaked at 26–28 °C, with the microorganisms producing more proteases per bacterial cell or increasing the rate of proteolytic activity of the same proteases (potentially metalloproteases). This activity may promote coral tissue necrosis and aid in ensuing progression of the coral BBD.     

Plasminogen activator activity in differentiating leukemia cells

Plasminogen activator (PA) activity of human promyelocytic leukemia cell line HL-60 was assayed by following the conversion of plasminogen to plasmin and the plasmin-mediated hydrolysis of 14C-labeled globin. When HL-60 cells were induced to differentiate into macrophages by 12-O-tetradecanoyl-phorbol-13-acetate (TPA), cell-associated PA activity and secretion of PA into the conditioned medium increased profoundly. PA activity increased earlier and as a result of lower concentrations of TPA than the ability of the cells to adhere. Exposure to 10(-6)M dexamethasone did not prevent TPA-induced adherence and produced a slight inhibition of cellular PA activity. These findings imply that TPA-induced differentiation of HL-60 cells to macrophage-like cells is associated with induction of PA activity.     

Global distribution and diversity of coral-associated Archaea and their possible role in the coral holobiont nitrogen cycle

Diversity, distribution and genetic comparison of Archaea associated with the surface mucus of corals from three genera, namely Acanthastrea sp., Favia sp. and Fungia sp., from the Gulf of Eilat, Israel and from Heron Island, Australia were studied. Sequencing of the 16S rRNA gene of the coral-associated Archaea revealed dominance of Crenarchaeota (79%, on average). In this phylum, 87% of the sequences were similar (>or= 97%) to the Thermoprotei, with 76% of these being similar (>or= 97%) to the ammonium oxidizer, Nitrosopumilus maritimus. Most of the coral-associated euryarchaeotal sequences (69%) were related to marine group II, while other euryarchaeotal clades were found to be related to anaerobic methanotrophs (8%), anaerobic nitrate reducers (i.e. denitrification, 15%) and marine group III (8%). Most of the crenarchaeotal and euryarchaeotal coral-associated 16S rRNA gene sequences from Heron Island (61%) and from the Gulf of Eilat (71%) were closely related (>or= 97%) to sequences previously derived from corals from the Virgin Islands. Analysis of archaeal amoA sequences obtained from the fungiid coral, Fungia granulosa, divided into three clades, all related to archaeal sequences previously obtained from the marine environment. These sequences were distantly related to amoA sequences previously found in association with other coral species. Preliminary experiments suggest that there is active oxidation of ammonia to nitrite in the mucus of F. granulosa. Thus, coral-associated Archaea may contribute to nitrogen recycling in the holobiont, presumably by acting as a nutritional sink for excess ammonium trapped in the mucus layer, through nitrification and denitrification processes.     

The Possible Role of Cyanobacterial Filaments in Coral Black Band Disease Pathology

Black band disease (BBD), characterized by a black mat or line that migrates across a coral colony leaving behind it a bare skeleton, is a persistent disease affecting massive corals worldwide. Previous microscopic and molecular examination of this disease in faviid corals from the Gulf of Eilat revealed a number of possible pathogens with the most prominent being a cyanobacterium identified as Pseudoscillatoria coralii. We examined diseased coral colonies using histopathological and molecular methods in order to further assess the possible role of this cyanobacterium, its mode of entry, and pathological effects on the coral host tissues. Affected areas of colonies with BBD were sampled for examination using both light and transmission electron microscopies. Results showed that this dominant cyanobacterium was found on the coral surface, at the coral–skeletal interface, and invading the polyp tissues and gastrovascular cavity. Although tissues surrounding the invasive cyanobacterial filaments did not show gross morphological alterations, microscopic examination revealed that the coral cells surrounding the lesion were dissociated, necrotic, and highly vacuolated. No amoebocytes were evident in the mesoglea of affected tissues suggesting a possible repression of the coral immune response. Morphological and molecular similarity of the previously isolated BBD-associated cyanobacterium P. coralii to the current samples strengthens the premise that this species is involved in the disease in this coral. These results indicate that the cyanobacteria may play a pivotal role in this disease and that the mode of entry may be via ingestion, penetrating the coral via the gastrodermis, as well as through the skeletal–tissue interface.     

The occurrence of the trehalose fermenting, tetracycline and polymyxin resistant phenotype among the Enterobacteriaceae

In Proteus morganii, P. mirabilis, and Providencia stuartii the ability to ferment trehalose and resistance to tetracycline were associated in 90%-97% of the strains. The same was true of at least 78% of the strains of Serratia marcescens. Proteus vulgaris showed a more quantitative association of the two traits. As the characters occur independently in 3-10% of the strains, the association is considered to be due to simultaneous selection in some natural niche. The trehalose fermenting, tetracycline and polymyxin resistant species ferment few other carbohydrates, fewer than the remainder of the Serratia species.     

Conditioning film and initial biofilm formation on electrochemical CaCO3 deposition on a metallic net in the marine environment

Electrochemical deposition of minerals is a unique technology for artificial reef constructions, relying on calcium carbonate (CaCO₃) build-up over metallic structures through electrolysis of seawater. The present study traces the first 72 h following electric current termination on bacterial biofilm build-up on a metallic net covered with CaCO₃. 16S rRNA clone libraries indicated a dynamic succession. Proteobacteria and Bacteroidetes were evident at all sampling times while Cyanobacteria appeared only within the first 8 h. A significant increase in total organic carbon (TOC) and total protein was observed after 48 h with a significant correlation (R ² = 0.74), indicating TOC is a good tool for characterizing initial biofilm formation. 18S rRNA gene sequences obtained 72 h following current termination indicated a significant presence of Cnidarians (51%). Understanding the dynamics among primary bacterial settlers is important because they play a crucial role in driving the colonization of sessile invertebrate communities on artificial, as well as natural surfaces.     

Impacts of nursery-based propagation and out-planting on coral-associated bacterial communities

Coral Reefs - Efforts to manage coral reef declines are increasingly turning towards in situ propagation of corals to aid reef recovery. Understanding the factors that influence...