Global Tonga tsunami explained by a fast-moving atmospheric source.

Volcanoes can produce tsunamis by means of earthquakes, caldera and flank collapses, pyroclastic flows or underwater explosions1-4. These mechanisms rarely displace enough water to trigger transoceanic tsunamis. Violent volcanic explosions, however, can cause global tsunamis1,5 by triggering acoustic-gravity waves6-8 that excite the atmosphere-ocean interface. The colossal eruption of the Hunga Tonga-Hunga Ha'apai volcano and ensuing tsunami is the first global volcano-triggered tsunami recorded by modern, worldwide dense instrumentation, thus providing a unique opportunity to investigate the role of air-water-coupling processes in tsunami generation and propagation. Here we use sea-level, atmospheric and satellite data from across the globe, along with numerical and analytical models, to demonstrate that this tsunami was driven by a constantly moving source in which the acoustic-gravity waves radiating from the eruption excite the ocean and transfer energy into it by means of resonance. A direct correlation between the tsunami and the acoustic-gravity waves' arrival times confirms that these phenomena are closely linked. Our models also show that the unusually fast travel times and long duration of the tsunami, as well as its global reach, are consistent with an air-water-coupled source. This coupling mechanism has clear hazard implications, as it leads to higher waves along land masses that rise abruptly from long stretches of deep ocean waters.

Molecular phylogenetic relationships reveal contrasting evolutionary patterns in Gorgoniidae (Octocorallia) in the Eastern Pacific.

The description and delimitation of species in an evolutionary framework is essential for understanding patterns of biodiversity and distribution, and in the assessment of conservation strategies for natural resources. This study seeks to clarify the evolutionary history and genetic variation within and between closely related octocoral species that are fundamental to benthic marine ecosystems for harbouring a high diversity of associated fauna. For our study system, we focused on members of the Gorgoniidae family in the Eastern Pacific, particularly of the Ecuadorian littoral, a less studied marine ecosystem. According to our results, the diagnosis of the genus Pacifigorgia is here amended to include species previously considered in the genus Leptogorgia. The genera Leptogorgia and Eugorgia are included within a single clade, and neither are recovered as monophyletic. In this case, according to the priority rule of the International Code of Zoological Nomenclature (ICZN), our proposal is to include the species considered in these two genera in Leptogorgia. In addition, we found evidence of interesting speciation patterns: morphological differentiation with no apparent genetic differentiation (in Pacifigorgia), and inconsistencies between mitochondrial and nuclear data that suggest a hybridisation phenomenon (in Leptogorgia). In the first case, recent radiation, ancient hybridisation, sympatric speciation, and in the second, reticulate evolution may have contributed to the evolutionary history of the studied taxa. Therefore, incongruences observed between morphological and molecular evidences in these octocorals, and in corals in general, may reveal the types of events/patterns that have influenced their evolution.

Reducing Antibiotic Duration for Uncomplicated UTI in the Pediatric Emergency Department.

BACKGROUND: Short-duration (3-5 days) antibiotic treatment of uncomplicated urinary tract infection (uUTI) in children >24 months of age is equivalent to longer-duration antibiotic treatment, with added benefits of antibiotic stewardship. At our pediatric emergency department (ED), 13% of 5- to 18-year-old patients discharged with uUTI received ≤5 days of antibiotics. We aimed to increase short-duration prescriptions in patients with uUTI from 13% to >50% over 12 months. METHODS: This quality improvement project was conducted from January 2021 to August 2022. Complicated UTI was excluded. Interventions included education, practice feedback, and electronic health record changes. The outcome measure, the proportion of children treated with a short antibiotic duration, was studied by using p-charts. Antibiotic days saved were calculated. Revisits with UTI within 14 days of confirmed uUTI treated with short-duration antibiotics (balancing measure) were analyzed by using Fisher's exact test. RESULTS: In 1292 (n = 363 baseline, 929 post-intervention) eligible patients treated for uUTI, shorter antibiotic duration increased from 13% to 91%. We met our 50% aim within 2 months, with continued improvement leading to an additional centerline shift. Consequently, 2619 antibiotic days were saved. Two of 334 (0.6%) patients returned (P = NS) within 14 days of the index visit with a culture-positive uUTI. CONCLUSIONS: By using education, feedback, and electronic health record changes, we decreased antibiotic duration in children discharged from the ED for uUTI without a significant increase in return visits with UTI. These interventions can be expanded to wider age groups and other outpatient settings.

Suction-Based Optical Coherence Elastography for the Biomechanical Characterization of Pathological Skin Conditions: A Pilot Study.

Accurate characterization of mechanical properties is crucial in the evaluation of therapeutic effects for problematic skin conditions. A pilot study was carried out using a novel optical coherence elastography (OCE) device, combining mechanical characterization through suction-based deformation and imaging through optical coherence tomography. Using AI-assisted image segmentation and a power-law model, we were able to describe the mechanical behavior, comparing with measurements from the most commonly used commercial instrument (Cutometer) and subjective analyses of stiffness using the Patient and Observer Scar Assessment Scale. Twenty subjects were included with either keloids or hypertrophic scars. Measurements were fast and produced no discomfort. Mechanical and structural (epidermal thickness and rugosity) descriptors in pathologic skin conditions differed significantly from those in control tissue. We showed for the first time, the clinical feasibility of this novel suction-based OCE device in evaluating mechanical and structural properties in pathological skin conditions such as scars.

Computerised vaccination register for the Murcia region, Spain, 1991 to 2011.

We describe the Murcia regional vaccination register in Spain, which was set up in 1991, detailing its main features, advantages and limitations. We also report on some recent special actions carried out that led to an improvement in vaccination coverage against measles, rubella and mumps (MMR): by using the vaccination register, we were able to identify and vaccinate persons aged under 20 years in a measles outbreak in 2010 in the town of Jumilla who were not adequately vaccinated for their age with MMR vaccine. From spring 2012, use of our register will enable us to identify susceptible individuals in our region under 40 years of age who have received fewer than two doses of MMR vaccine and call them for the appropriate vaccination. We also set out our experience in the use of barcodes to identify individuals and collect vaccine data: our data show that the barcodes help to improve data quality and completeness. Finally, we identify certain challenges in search of greater standardisation for systems and encoding that is necessary to enable an easy exchange of data between different registers.

The effect of the sixth sulfur ligand in the catalytic mechanism of periplasmic nitrate reductase.

The catalytic mechanism of nitrate reduction by periplasmic nitrate reductases has been investigated using theoretical and computational means. We have found that the nitrate molecule binds to the active site with the Mo ion in the +6 oxidation state. Electron transfer to the active site occurs only in the proton-electron transfer stage, where the Mo(V) species plays an important role in catalysis. The presence of the sulfur atom in the molybdenum coordination sphere creates a pseudo-dithiolene ligand that protects it from any direct attack from the solvent. Upon the nitrate binding there is a conformational rearrangement of this ring that allows the direct contact of the nitrate with Mo(VI) ion. This rearrangement is stabilized by the conserved methionines Met141 and Met308. The reduction of nitrate into nitrite occurs in the second step of the mechanism where the two dimethyl-dithiolene ligands have a key role in spreading the excess of negative charge near the Mo atom to make it available for the chemical reaction. The reaction involves the oxidation of the sulfur atoms and not of the molybdenum as previously suggested. The mechanism involves a molybdenum and sulfur-based redox chemistry instead of the currently accepted redox chemistry based only on the Mo ion. The second part of the mechanism involves two protonation steps that are promoted by the presence of Mo(V) species. Mo(VI) intermediates might also be present in this stage depending on the availability of protons and electrons. Once the water molecule is generated only the Mo(VI) species allow water molecule dissociation, and, the concomitant enzymatic turnover.

Bacterial nitrate reductases: Molecular and biological aspects of nitrate reduction.

Nitrogen is a vital component in living organisms as it participates in the making of essential biomolecules such as proteins, nucleic acids, etc. In the biosphere, nitrogen cycles between the oxidation states +V and -III producing many species that constitute the biogeochemical cycle of nitrogen. All reductive branches of this cycle involve the conversion of nitrate to nitrite, which is catalyzed by the enzyme nitrate reductase. The characterization of nitrate reductases from prokaryotic organisms has allowed us to gain considerable information on the molecular basis of nitrate reduction. Prokaryotic nitrate reductases are mononuclear Mo-containing enzymes sub-grouped as respiratory nitrate reductases, periplasmic nitrate reductases and assimilatory nitrate reductases. We review here the biological and molecular properties of these three enzymes along with their gene organization and expression, which are necessary to understand the biological processes involved in nitrate reduction.

Solubilization and fractionation of paired helical filaments.

Paired helical filaments isolated from brains of two different patients with Alzheimer's disease were extensively treated with the ionic detergent, sodium dodecyl sulphate. Filaments were solubilized at different extents, depending on the brain examined, thus suggesting the existence of two types of paired helical filaments: sodium dodecyl sulphate-soluble and insoluble filaments. In the first case, the number of structures resembling paired helical filaments greatly decreased after the detergent treatment, as observed by electron microscopy. Simultaneously, a decrease in the amount of sedimentable protein was also observed upon centrifugation of the sodium dodecyl sulfate-treated paired helical filaments. A sodium dodecyl sulphate-soluble fraction was isolated as a supernatant after low-speed centrifugation of the sodium dodecyl sulphate-treated paired helical filaments. The addition of the non-ionic detergent Nonidet-P40 to this fraction resulted in the formation of paired helical filament-like structures. When the sodium dodecyl sulphate-soluble fraction was further fractionated by high-speed centrifugation, three subfractions were observed: a supernatant, a pellet and a thin layer between these two subfractions. No paired helical filaments were observed in any of these subfractions, even after addition of Nonidet P-40. However, when they were mixed back together, the treatment with Nonidet P-40 resulted in the visualization of paired helical filament-like structures. These results suggest that at least two different components are needed for the reconstitution of paired helical filaments as determined by electron microscopy. The method described here may allow the study of the components involved in the formation of paired helical filaments and the identification of possible factors capable of blocking this process.

[Study of the sentinel node in breast cancer using lymphoscintigraphy and a fast method for cytokeratin]. / Estudio del ganglio centinela en el cáncer de mama mediante linfogammagrafía y citoqueratina por congelación.

INTRODUCTION: Histopathological examination of the axillary sentinel node (SN) is becoming a routine procedure in the surgical phase of infiltrating ductal carcinoma of the breast (IDC). The SN exam may yield false negative cases mainly due to identification failure of the SN but some of the false negative cases may be the result of the pathological examination procedure applied. MATERIAL AND METHODS: Sixty two (62) cases of clinically staged N0 IDC of the breast by TNM nomenclature were assigned to breast surgery along with conventional axillary node dissection. The identification technique included lymphoscintigraphy and intraoperative gamma-detecting probe after peritumoral injection of 99mTc-labeled colloids.The histological study of SN was performed with paired 4 microm slices and staining with hematoxylin-eosin and with a fast method of cytokeratins for freezing. RESULTS: In only two of the 62 patients, it was not possible to identify the SN. Eighteen of the remaining 60 had SN involvement by metastasis, having no metastases in the other nodes of the axillary dissection in 6 of them. Ten of those were micrometastasis (size of metastasis= or <0.2 cm). In two out of these last 10 cases, diagnosis of the micrometastasis was only possible using slices stained with CK. There were no false negative results. CONCLUSIONS: The lymphoscintigraphy, after peritumoral injection of small volumes and low dose of the tracer, makes it possible to obtain excellent results in the intraoperative detection of the SN in breast cancer. The study of this SN with a fast method for CK decreases the number of false negative results of the technique.

Note: development of ESS Bilbao's proton ion source: Ion Source Hydrogen positive.

The Ion Source Hydrogen positive is a 2.7 GHz off-resonance microwave discharge ion source. It uses four coils to generate an axial magnetic field in the plasma chamber around 0.1 T that exceeds the ECR resonance field. A new magnetic system was designed as a combination of the four coils and soft iron in order to increase the reliability of the source. The description of the simulations of the magnetic field and the comparison with the magnetic measurements are presented. Moreover, results of the initial commissioning of the source for extraction voltage until 50 kV will be reported.

[Plain-film radiography in the study of spinal pain]. / La radiografía simple en el estudio del dolor de la columna vertebral.

The introduction of tomographic imaging techniques, fundamentally computed tomography and magnetic resonance imaging, has led to a gradual decrease in the indications for plain-film radiography, resulting in fewer patients studied and fewer projections for each patient. Consequently, plain-film studies of the spine have received less attention and radiologists are less familiar with the typical findings in normal and pathologic conditions of the spine. Nevertheless, plain-film radiography continues to be widely used in both primary and specialized care. Thus, radiologists still need to be aware of the normal radiologic anatomy of the spine and of the radiologic manifestations of the diverse pathological processes that can affect the spinal column and that can cause pain. The aim of this article is to review the manifestations on plain-film radiography of a wide variety of diseases that can cause back pain, including congenital, traumatic, degenerative, tumor-related, inflammatory, and infectious diseases and processes.

Structural and transcriptional properties of different nucleosomal particles containing high mobility group proteins 14 and 17 (HMG 14/17).

Binding of high mobility group (HMG) proteins 14 and 17 (HMG 14/17) to complete nucleosomal cores and to cores lacking one H2A.H2B dimer, the amino-terminal tails of histones, or both one H2A.H2B dimer and the amino-terminal ends of histones is accompanied by an overall stabilization of the particles as determined by thermal denaturation, circular dichroism and DNase I digestion. In spite of the structural stabilization brought about by HMG 14/17, the presence of these proteins causes little effect on the efficiency of the different nucleosomal particles as transcription templates for RNA polymerase II. The nucleosomal particles lacking one H2A.H2B dimer and containing two bound HMG 14/17 molecules are efficient in vitro transcription templates, which allow transcription of the whole length of the DNA present in the particle. These results are consistent with HMG 14/17 being present in active chromatin.

Interaction of RNA polymerase II with structurally altered nucleosomal particles. Transcription is facilitated by loss of one H2A.H2B dimer.

The loss of one H2A.H2B dimer from the nucleosomal core increases its affinity for RNA polymerase II and its efficiency as a transcription template, allowing transcription of the entire DNA present in the particle. In contrast, the nucleosomal core lacking the amino-terminal ends of histones, which has an affinity for polymerase equal to that of the H2A.H2B-deficient core, shows transcription properties similar to those of the whole nucleosomal core, with synthesis of short RNA chains (40 nucleotides or less). Similar results were obtained with a bacterial RNA polymerase. The improved efficiency of the H2A.H2B-deficient cores as transcription templates does not appear to be produced by nonspecific loss of protein or structural relaxation of the particle. These results suggest that a particle lacking one H2A.H2B dimer might be a necessary intermediate during in vivo transcription.

Peptidyl transferase centres of rat and yeast ribosomes. Different response to modification of protein amino groups.

Modification of rat liver ribosomes with dimethylmaleic anhydride, a reagent for protein amino groups, causes a large stimulation of peptidyl transferase activity assayed by the "fragment" reaction, as well as the inactivation of poly(U)-directed polyphenylalanine synthesis. In contrast to rat ribosomes, the peptidyl transferase of yeast ribosomes is little affected by modification. Although other interpretations are not excluded, these results might be due to differences between the peptidyl transferase centres of mammalian and yeast ribosomes.

Interaction of RNA polymerase II with acetylated nucleosomal core particles.

Chemical acetylation of nucleosomal cores is accompanied by an increase in their efficiency as in vitro transcription templates. Low amounts of acetic anhydride cause preferential modification of the amino-terminal tails of core histones. Modification of these domains, which causes moderate structural effects, is apparently correlated with the observed stimulation of RNA synthesis. In contrast, extensive modification of the globular regions of core histones, which is accompanied by a large structural relaxation of the particle, causes little additional effect on transcription. Acetylation of the amino-terminal domains of histones might stimulate transcription by changing the interaction of the histone tails with components of the transcriptional machinery.

Reconstitution of rat liver 60S ribosomal subunits following disassembly by dimethylmaleic anhydride.

Modification of 60S ribosomal subunits from rat liver with dimethylmaleic anhydride (60 mumols/ml) is accompanied by release of 35% of the protein. The acidic ribosomal proteins, as well as 9 basic proteins, are selectively liberated from the ribosomal subunits. Reconstitution of the protein-deficient particles with the corresponding split proteins is accompanied by substantial recovery of the original polyphenylalanine synthetic activity. The described reconstitution procedure can be used to investigate the roles played by the released proteins and the functional similarities of proteins from different sources. Hybrid reconstitution of residual ribosomal particles from rat liver or yeast with the corresponding heterologous split proteins produces subunits which have incorporated heterologous proteins but are inactive in polyphenylalanine synthesis.

Dicarboxylic acid anhydrides as dissociating agents of protein-containing structures.

Dissociation of protein-containing structures by modification of protein amino groups with dicarboxylic acid anhydrides is a mild procedure which, in some cases, offers advantages over treatment with alternative dissociating agents, such as urea, guanidine hydrochloride, detergents, high ionic strength, and extremes of pH. In addition to dissociating multimeric proteins and protein aggregates, dicarboxylic acid anhydrides are effective dissociating agents for membrane-bound proteins and nucleoprotein particles. With most dicarboxylic acid anhydrides reviewed, the introduced reagent residues can be eliminated under moderate acid conditions, which allows the purification of unmodified individual components, and the use of diassembly-reconstitution systems valuable for investigating the structural and functional roles played by the individual components of complex particles. Each reagent can be suitable for a particular purpose, depending on the required specificity of the modification and stability of the modified groups. The stability of the acylated amino groups ranges from the very stable succinylated amino groups to the very labile acylation obtained with dimethylmaleic anhydride. Between these extremes, the stability of the modified amino groups decreases stepwise in the following order: maleic, exo-cis-3,6-endoxo-delta 4-tetrahydrophthalic, citraconic, and 3,4,5,6-tetrahydrophthalic anhydride. With respect to the selectivity of the produced modification, little or no modification of hydroxyamino acid and cysteine residues has been observed with dimethylmaleic, exo-cis-3,6-endoxo-delta 4-tetrahydrophthalic, and 3,4,5,6-tetrahydrophthalic anhydrides. With the other reagents, the extent of modification of hydroxyamino acid residues increases in the order citraconic, maleic and succinic anhydride. Citraconic and maleic anhydrides can produce irreversible modification of cysteine residues, the reactivity of sulfhydryl groups being higher with maleic anhydride.

Effect of high mobility group proteins 14 and 17 on the structural and transcriptional properties of acetylated complete and H2A.H2B-deficient nucleosomal cores.

Acetylation of H2A.H2B-deficient nucleosomal cores, like that of the complete particles, causes a substantial increase in the efficiency of the particles as in vitro transcription templates. Binding of the high mobility group proteins 14 and 17 (HMG 14/17) to chemically acetylated nucleosomal particles, both complete nucleosomal cores and those lacking one of the two H2A.H2B dimers, is accompanied by a small structural stabilization. The affinity of HMG 14/17 for the nucleosomal cores is not affected by acetylation of the particles. With acetylated complete and H2A.H2B-deficient cores, the binding of HMG 14/17 does not cause any significant change in the levels of RNA synthesis, which is compatible with the presence of these proteins in transcriptionally active nucleosomes.

Interaction with RNA polymerase of nucleosomal cores lacking one H2A.H2B dimer.

Nucleosomal particles lacking one H2A.H2B dimer interact with RNA polymerase from Escherichia coli more strongly than the complete nucleosomal core particles. Moreover, the in vitro transcription of the H2A.H2B-deficient particles is much more efficient than that of the whole nucleosomal cores, both in the presence and absence of rifampicin. Although a substantial fraction of particles in the preparation of whole nucleosomal cores binds to RNA polymerase, the efficiency of these particles as transcription templates is very small. This block to transcription is partially eliminated when one H2A.H2B dimer is released from the core particle. Our results suggest that the lack of one H2A.H2B dimer from nucleosomal particles might be required for the formation of complexes with RNA polymerase active in transcription.