Mass Coral Reef Bleaching: A Recent Outcome of Increased El Niño Activity?

Coral reefs are generally considered to be the most biologically productive of all marine ecosystems, but in recent times these vulnerable aquatic resources have been subject to unusual degradation. The general decline in reefs has been greatly accelerated by mass bleaching in which corals whiten en masse and often fail to recover. Empirical evidence indicates a coral reef bleaching cycle in which major bleaching episodes are synchronized with El Niño events that occur every 3–4 years on average. By heating vast areas of the Pacific Ocean, and affecting the Indian and Atlantic Oceans as well, El Niño causes widespread damage to reefs largely because corals are very sensitive to temperature changes. However, mass bleaching events were rarely observed before the 1970s and their abrupt appearance two decades ago remains an enigma. Here we propose a new explanation for the sudden occurrence of mass bleaching and show that it may be a response to the relative increase in El Niño experienced over the last two decades.     

Patterns in the structural typology of benthic communities on two coral reefs of the central Great Barrier Reef

The morphological life-forms, that is to say, physiognomic-structural attributes, of two coral reef communities were used in a numerical analysis to determine the power of these attributes in recovering the underlying community structure. We used 17 attributes from the benthic communities at 6 reef slope sites on each of a midshelf and off-shore reef of the central Great Barrier Reef. These reefs had been previously well studied by traditional species-level means for several major taxonomic groups such as corals, fish and soft corals. Our multivariate analyses were able to recover broad patterns of between-reef affinity and discrete within-reef zonation patterns similar to those found in earlier studies, and in broad accord with the prevailing model of reef community structure, but with far greater efficacy. But perhaps more importantly, by placing all the benthos within the same context for the first time, our analyses were able to recover new patterns of community structure independent of the ones described earlier. This suggests that single-model explantations for the complex phenomena of coral reefs are likely to be inadequate.     

Patterns in the use of space by benthic communities on two coral reefs of the Great Barrier Reef

A rapid benthic line-transect survey method for use by non-specialist observers is described. At both Davies Reef (mid-continental shelf) and Myrmidon Reef (outer-continental shelf) in the central Great Barrier Reef a set of 6 sites of varying depths on the reef flat, crest and slope were sampled using this method. At least 10 contiguous 10 m transects were made at each site. Benthic organisms were recorded as life forms with categories based on both high level taxa and morphologies, and including scleractinian corals, alcyonarians, sponges, algae and others. Percentage cover data for 19 benthic categories are presented for all sites. Coral cover on both reefs is high on the crest and slope but low on the reef flat. At all sites the cover of soft corals and sponges is much less than cover of hard corals and algae. Abundances of soft corals and sponges increase with depth. Analysis of gaps between hard corals show that many colonies grow close to each other (<1 cm)even when total coral cover is low.     

Role of endogenous gibberellins in germination of melon (Cucumis melo) seeds

The effect of the plant growth retardants ancymidol. mefluidide and uniconazole on germination of two melon accessions differing in their ability to germinate at 14°C was examined. The accessions were the cold sensitive Noy Yizre'el and the cold tolerant Persia 202. The three growth retardants were able to delay the germination of intact Noy Yizre'el seeds, but did not affect that of intact Persia 202 seeds. On the other hand germination of decoated seeds of both accessions was unaffected by these inhibitors at normal oxygen concentration, but was inhibited at 5% oxygen. When gibberellin-like activity was measured by a dwarf rice biological assay following HPLC fractionation, it was found that seeds of Persia 202 contained much more gibberellin-like activity than Noy Yizre'el seeds. Among the extracted compounds several endogenous gibberellins were identified by combined gas chromatography-mass spectrometry (GC-MS). They included GA₄, GA₂₀, GA₁ and GA₃ in Noy Yizre'el and GA₃₄, GA₂₀, GA₁ and GA₈ in Persia 202. It is suggested that the better germination of intact Persia 202 seeds, compared to Noy Yizre'el seeds at low temperature and low oxygen concentration, is due to a higher endogenous level of GA and a better seed coat permeability to oxygen.     

Sexual Therapy of Patients with Cardiovascular Disease

Physical illness or disability inevitably has a damaging effect on sexual relationships. Physicians are usually unaware of the sexual consequences of illness on their patients, and lack experience in treating sexual dysfunctions.The report of treatment of a couple with serious cardiovascular disease illustrates the potential efficacy of brief sex therapy for improving the quality of a patient''s life. If a primary physician lacks the skills to conduct sex therapy, he may collaborate with nonphysician therapists. The physician''s knowledge of the physiological and psychological effects of a specific illness on his patient is essential to successful therapy. Often, simple education, encouragement or reassurance by the physician is enough to overcome the damaging effects of illness on a patient''s sex life.     

Characterization of PfiT/PfiA toxin–antitoxin system of Pseudomonas aeruginosa that affects cell elongation and prophage induction

Toxin–antitoxin (TA) systems are small genetic modules usually consisting of two elements—a toxin and an antitoxin. The abundance of TA systems among various bacterial strains may indicate an important evolutionary role. Pseudomonas aeruginosa, which can be found in a variety of niches in nature, is an opportunistic pathogen for various hosts. While P. aeruginosa strains are very versatile and diverse, only a few TA systems were characterized in this species. Here, we describe a newly characterized TA system in P. aeruginosa that is encoded within the filamentous Pf4 prophage. This system, named PfiT/PfiA, is a homologue of the ParE/YefM TA system. It is a type II TA system, in which the antitoxin is a protein that binds the toxic protein and eliminates the toxic effect. PfiT/PfiA carries several typical type II characteristics. Specifically, it constitutes two small genes expressed in a single operon, PfiT inhibits growth and PfiA eliminates this effect, PfiA binds PfiT, and PfiT expression results in elongated cells. Finally, we assigned a novel function to this TA system, where an imbalance between PfiT and PfiA, favouring the toxin, resulted in cell elongation and an increase in virion production.     

Potential Early Predictors for Outcomes of Experimental Hemorrhagic Shock Induced by Uncontrolled Internal Bleeding in Rats

Uncontrolled hemorrhage, resulting from traumatic injuries, continues to be the leading cause of death in civilian and military environments. Hemorrhagic deaths usually occur within the first 6 hours of admission to hospital; therefore, early prehospital identification of patients who are at risk for developing shock may improve survival. The aims of the current study were: 1. To establish and characterize a unique model of uncontrolled internal hemorrhage induced by massive renal injury (MRI), of different degrees (20-35% unilateral nephrectomy) in rats, 2. To identify early biomarkers those best predict the outcome of severe internal hemorrhage. For this purpose, male Sprague Dawley rats were anesthetized and cannulas were inserted into the trachea and carotid artery. After abdominal laparotomy, the lower pole of the kidney was excised. During 120 minutes, hematocrit, pO₂, pCO₂, base excess, potassium, lactate and glucose were measured from blood samples, and mean arterial pressure (MAP) was measured through arterial tracing. After 120 minutes, blood loss was determined. Statistical prediction models of mortality and amount of blood loss were performed. In this model, the lowest blood loss and mortality rate were observed in the group with 20% nephrectomy. Escalation of the extent of nephrectomy to 25% and 30% significantly increased blood loss and mortality rate. Two phases of hemodynamic and biochemical response to MRI were noticed: the primary phase, occurring during the first 15 minutes after injury, and the secondary phase, beginning 30 minutes after the induction of bleeding. A Significant correlation between early blood loss and mean arterial pressure (MAP) decrements and survival were noted. Our data also indicate that prediction of outcome was attainable in the very early stages of blood loss, over the first 15 minutes after the injury, and that blood loss and MAP were the strongest predictors of mortality.     

Dating the Lower to Middle Paleolithic transition in the Levant: A view from Misliya Cave,Mount Carmel,Israel

The transition from the Lower to the Middle Paleolithic in the Levant is a crucial event in human evolution, since it may involve the arrival of a new human population. In the current study, we present thermoluminescence (TL) dates obtained from 32 burnt flints retrieved from the late Lower Paleolithic (Acheulo-Yabrudian) and Early Middle Paleolithic (Mousterian) layers of Misliya Cave, Mount Carmel, Israel. Early Middle Paleolithic industries rich in Levallois and laminar products were assigned mean ages ranging from ∼250 to ∼160 ka (thousands of years ago), suggesting a production of this industry during MIS 7 and the early part of MIS 6. The mean ages obtained for the samples associated with the Acheulo-Yabrudian (strengthened by an isochron analysis) indicate a production of this cultural complex ∼250 ka ago, at the end of MIS 8. According to the Misliya TL dates, the transition from the Lower to the Middle Paleolithic in the site took place at the limit MIS 8/7 or during the early part of MIS 7. The dates, together with the pronounced differences in lithic technology strongly suggest the arrival of a new population during this period.     

Bacterial Consortium of Millepora dichotoma Exhibiting Unusual Multifocal Lesion Event in the Gulf of Eilat, Red Sea

Colonies of the hydrocoral Millepora dichotoma along the Gulf of Eilat are exhibiting unusual tissue lesions in the form of white spots. The emergence and rapid establishment of these multifocal tissue lesions was the first of its kind reported in this region. A characterization of this morphological anomaly revealed bleached tissues with a significant presence of bacteria in the tissue lesion area. To ascertain possible differences in microbial biota between the lesion area and non-affected tissues, we characterized the bacterial diversity in the two areas of these hydrocorals. Both culture-independent (molecular) and culture-dependent assays showed a shift in bacterial community structure between the healthy and affected tissues. Several 16S rRNA gene sequences retrieved from the affected tissues matched sequences of bacterial clones belonging to Alphaproteobacteria and Bacteroidetes members previously associated with various diseases in scleractinian corals.