Rapid decline in extratropical Andean snow cover driven by the poleward migration of the Southern Hemisphere westerlies.

Seasonal snow in the extratropical Andes is a primary water source for major rivers supplying water for drinking, agriculture, and hydroelectric power in Central Chile. Here, we used estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze changes in snow cover extent over the period 2001-2022 in a total of 18 watersheds spanning approximately 1,100 km across the Chilean Andes (27-36°S). We found that the annual snow cover extent is receding in the watersheds analyzed at an average pace of approximately 19% per decade.

Ground-based measurements of the weather-driven sky radiance distribution in the Southern Hemisphere.

The angular distribution of the sky radiance determines the energy generation of solar power technologies as well as the ultraviolet (UV) doses delivered to the biosphere. The sky-diffuse radiance distribution depends on the wavelength, the solar elevation, and the atmospheric conditions. Here, we report on ground-based measurements of the all-sky radiance at three sites in the Southern Hemisphere across a transect of about 5,000 km: Santiago (33°S, a mid-latitude city of 6 million inhabitants with endemic poor air quality), King George Island (62°S, at the northern tip of the Antarctic Peninsula, one of the cloudiest regions on Earth), and Union Glacier (79°S, a snow-covered glacier in the vast interior of Western Antarctica).

[One stage surgical treatment of aortic coarctation associated with bicuspid aortic valve. Report of one case].

Percutaneous surgery is the treatment of choice of isolated aortic coarctation in adults However, when there are other heart problems related to aortic coarctation, its surgical management may vary. We report a 41-year-old male presenting with aortic coarctation associated with severe, symptomatic, bicuspid aortic valve lesions and significant left ventricular dysfunction. He underwent open heart surgery for the surgical resolution of these problems.

Black carbon footprint of human presence in Antarctica.

Black carbon (BC) from fossil fuel and biomass combustion darkens the snow and makes it melt sooner. The BC footprint of research activities and tourism in Antarctica has likely increased as human presence in the continent has surged in recent decades. Here, we report on measurements of the BC concentration in snow samples from 28 sites across a transect of about 2,000 km from the northern tip of Antarctica (62°S) to the southern Ellsworth Mountains (79°S).

Persistent extreme ultraviolet irradiance in Antarctica despite the ozone recovery onset.

Attributable to the Montreal Protocol, the most successful environmental treaty ever, human-made ozone-depleting substances are declining and the stratospheric Antarctic ozone layer is recovering. However, the Antarctic ozone hole continues to occur every year, with the severity of ozone loss strongly modulated by meteorological conditions. In late November and early December 2020, we measured at the northern tip of the Antarctic Peninsula the highest ultraviolet (UV) irradiances recorded in the Antarctic continent in more than two decades.

Evaluation of MODIS-derived estimates of the albedo over the Atacama Desert using ground-based spectral measurements.

Surface albedo is an important forcing parameter that drives the radiative energy budget as it determines the fraction of the downwelling solar irradiance that the surface reflects. Here we report on ground-based measurements of the spectral albedo (350-2200 nm) carried out at 20 sites across a North-South transect of approximately 1300 km in the Atacama Desert, from latitude 18° S to latitude 30° S. These spectral measurements were used to evaluate remote sensing estimates of the albedo derived from the Moderate Resolution Imaging Spectroradiometer (MODIS).

Income inequality and COVID-19 mortality: Age-stratified analysis of 22 OECD countries.

Our study builds on a growing body of research that demonstrates an association between income inequality and COVID-19 mortality. Using Poisson multivariate regression, we age-stratify our analysis by separately examining each of four age groups over a nine-month study period in 22 OECD countries. Our full regression model controls for national median income and relative poverty, and a set of pandemic-specific variables to capture exposure, susceptibility and treatment.

Evaluation of Antarctic Ozone Profiles derived from OMPS-LP by using Balloon-borne Ozonesondes.

Predicting radiative forcing due to Antarctic stratospheric ozone recovery requires detecting changes in the ozone vertical distribution. In this endeavor, the Limb Profiler of the Ozone Mapping and Profiler Suite (OMPS-LP), aboard the Suomi NPP satellite, has played a key role providing ozone profiles over Antarctica since 2011. Here, we compare ozone profiles derived from OMPS-LP data (version 2.

[Robotic mitral valve repair and closure of atrial septal defect. Report of 13 procedures].

Unlabelled: Background Robot-assisted minimally invasive heart surgery is an effective alternative when compared with classical approaches. It has a low mortality and postoperative complications and its long-term durability is comparable with conventional techniques.

Aim: To report short- and long-term results with the use of a robot-assisted transthoracic approach.

Dry-Season Snow Cover Losses in the Andes (18°-40°S) driven by Changes in Large-Scale Climate Modes.

The Andean snowpack is the primary source of water for many communities in South America. We have used Landsat imagery over the period 1986-2018 in order to assess the changes in the snow cover extent across a north-south transect of approximately 2,500 km (18°-40°S). Despite the significant interannual variability, here we show that the dry-season snow cover extent declined across the entire study area at an average rate of about -12% per decade.

Elemental and Mineralogical Composition of the Western Andean Snow (18°S-41°S).

The snowpack is an important source of water for many Andean communities. Because of its importance, elemental and mineralogical composition analysis of the Andean snow is a worthwhile effort. In this study, we conducted a chemical composition analysis (major and trace elements, mineralogy, and chemical enrichment) of surface snow sampled at 21 sites across a transect of about 2,500 km in the Chilean Andes (18-41°S).

Characterization of the CrbS/R Two-Component System in Reveals a New Set of Genes under Its Control and a DNA Motif Required for CrbR-Mediated Transcriptional Activation.

The CrbS/R system is a two-component signal transduction system that regulates acetate utilization in , and . CrbS is a hybrid histidine kinase that belongs to a recently identified family, in which the signaling domain is fused to an SLC5 solute symporter domain through aSTAC domain. Upon activation by CrbS, CrbR activates transcription of the gene, which encodes an acetyl-CoA synthase (ACS), and the gene, which encodes an acetate/solute symporter.

Outcomes of a Less-Invasive Approach for Proximal Aortic Operations.

Background: Less-invasive techniques have previously been described for mitral and aortic valve operations; however, few studies have examined their benefit for aortic root and ascending aorta reconstruction. Using propensity matching, we compared outcomes of patients undergoing proximal aortic operations through a J incision compared with full sternotomy.

Methods: From January 1995 to January 2014, 8,533 patients underwent proximal aortic operations at Cleveland Clinic.

Origin of a folded repeat protein from an intrinsically disordered ancestor.

Repetitive proteins are thought to have arisen through the amplification of subdomain-sized peptides. Many of these originated in a non-repetitive context as cofactors of RNA-based replication and catalysis, and required the RNA to assume their active conformation. In search of the origins of one of the most widespread repeat protein families, the tetratricopeptide repeat (TPR), we identified several potential homologs of its repeated helical hairpin in non-repetitive proteins, including the putatively ancient ribosomal protein S20 (RPS20), which only becomes structured in the context of the ribosome.

Successful Re-Repeat Resection of Primary Left Atrial Sarcoma After Previous Tumor Resection and Cardiac Autotransplant Procedures.

Primary cardiac sarcomas are rare but aggressive tumors and can present a technical challenge with regard to surgical approach and resection. Complete surgical resection, when feasible, remains crucial for palliation of symptoms and for its role as the mainstay of cardiac sarcoma therapy. Surgical resection of recurrent cardiac sarcomas, though formidable, is technically feasible and may provide reasonable survival, especially when the recurrence is local and the metastatic load is limited.

A Multiprotein DNA Translocation Complex Directs Intramycelial Plasmid Spreading during Streptomyces Conjugation.

Unlabelled: Conjugative DNA transfer in mycelial Streptomyces is a unique process involving the transfer of a double-stranded plasmid from the donor into the recipient and the subsequent spreading of the transferred plasmid within the recipient mycelium. This process is associated with growth retardation of the recipient and manifested by the formation of circular inhibition zones, named pocks. To characterize the unique Streptomyces DNA transfer machinery, we replaced each gene of the conjugative 12.

The stability region of the Streptomyces lividans plasmid pIJ101 encodes a DNA-binding protein recognizing a highly conserved short palindromic sequence motif.

Conjugation is a driving force in the evolution and shaping of bacterial genomes. In antibiotic producing streptomycetes even small plasmids replicating via the rolling-circle mechanism are conjugative. Although they encode only genes involved in replication and transfer, the molecular function of most plasmid encoded proteins is unknown.

Intracardiac abscess with cutaneous fistula secondary to ventricular septal defect repair simulating sternal wound infection.

Cutaneous fistula as a clinical presentation of intracardiac abscess of the right side is such an unusual occurrence that it has not until now been reported in the English-language medical literature. We present a rare case of right-sided infective endocarditis caused by Achromobacter xylosoxidans in which recurrent infection presented as sternal wound discharge. The infection was found to have an intracardiac origin and was successfully managed by radical débridement on cardiopulmonary bypass.

A septal chromosome segregator protein evolved into a conjugative DNA-translocator protein.

Streptomycetes, Gram-positive soil bacteria well known for the production of antibiotics feature a unique conjugative DNA transfer system. In contrast to classical conjugation which is characterized by the secretion of a pilot protein covalently linked to a single-stranded DNA molecule, in Streptomyces a double-stranded DNA molecule is translocated during conjugative transfer. This transfer involves a single plasmid encoded protein, TraB.

Distal landing zone open fenestration facilitates endovascular elephant trunk completion and false lumen thrombosis.

Background: Controversy surrounds the endovascular treatment of chronic dissection because of inconsistent remodeling of the aorta. The purpose of this study was to assess efficacy and safety of a novel technique for repairing aneurysmal change associated with chronic descending aortic dissection.

Methods: From July 2007 to April 2011, 24 patients with descending aortic aneurysmal change, consequent to previously repaired ascending aortic dissection or medically treated descending dissection, underwent combined open first-stage elephant trunk (ET) insertion and fenestration of the descending aorta intimal flap.

[Negative-pressure wound therapy versus standard wound dressing in the treatment of diabetic foot amputation. A randomised controlled trial].

Introduction: Foot amputation wounds in patients with diabetes are complex and treatment is often difficult. At the moment negative pressure wound therapy (NPWT) is widely used for the treatment of several types of wounds. Nevertheless, the clinical evidence to support the application of this dressing in foot amputation wounds in patients with diabetes is scarce.

Transcriptional interference and repression modulate the conjugative ability of the symbiotic plasmid of Rhizobium etli.

Bacteria of the order Rhizobiales are able to establish nitrogen-fixing symbioses with legumes. Commonly, genes for symbiosis are harbored on large symbiotic plasmids. Although the transfer of symbiotic plasmids is commonly detected in nature, there are few experimentally characterized examples.