Catching Element Formation In The Act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions.Comment: 14 pages including 3 figure

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Nocturia and chronic kidney disease: Systematic review and nominal group technique consensus for primary care assessment and treatment

Context: Reduced renal function impairs salt and water homeostasis, which can drive nocturnal or 24-h polyuria. Nocturia can arise early in chronic kidney disease (CKD). Evidence-based recommendations can facilitate management outside nephrology clinics. Objective: To conduct a systematic review (SR) of nocturia in CKD and achieve expert consensus for management in primary care and in specialist clinics outside nephrology. Evidence acquisition: Four databases were searched from January 2000 to April 2020. A total of 4011 titles and abstracts were screened, and 108 studies underwent full-text screening. Seven studies met the inclusion criteria and two were identified through other sources. Consensus was achieved among an expert panel with public involvement using the nominal group technique (NGT). Evidence synthesis: Several plausible mechanisms contribute to nocturnal or 24-h polyuria in CKD, but there is little evidence on interventions to improve nocturia. NGT assessment recommendations for nocturia (at least two voids per night) in patients with CKD or at risk of CKD being assessed in a non-nephrology setting are: history (thirst, fluid intake), medication review (diuretics, lithium, calcium channel antagonists, nonsteroidal anti-inflammatory medications), examination (oedematous state, blood pressure), urinalysis (haematuria and albumin/creatinine ratio), blood tests (blood urea, serum creatinine and electrolytes, estimated glomerular filtration rate), and a bladder diary. Renal ultrasound should follow local CKD guidelines. Treatment options include optimising blood pressure control, dietary adjustment to reduce salt intake, fluid advice, and a medication review. Referral to specialist nephrology services should follow local guidelines. Conclusions: CKD should be considered when evaluating patients with nocturia. The aim of assessment is to identify mechanisms and instigate therapy, but the latter may be more applicable to reducing wider morbidity associated with CKD than nocturia itself. Patient summary: People with kidney disease can suffer severe sleep disturbance because of a need to pass urine overnight. We looked at published research and found some useful information about the underlying mechanisms. A group of experts was able to develop practical approaches for assessing and treating this condition

Resection Prior to Liver Transplantation for Hepatocellular Carcinoma

OBJECTIVE: To evaluate the feasibility and postoperative course of liver transplantation (LT) in cirrhotic patients who underwent liver resection prior to LT for HCC. SUMMARY BACKGROUND DATA: Although LT provides longer survival than liver resection for treatment of small HCCs, donor shortage and long LT wait time may argue against LT. The feasibility and survival following LT after hepatic resection have not been previously examined. METHODS: Between 1991 and 2001, among 107 patients who underwent LT for HCC, 88 met Mazzafero’s criteria upon pathologic analysis of the explant. Of these, 70 underwent primary liver transplantation (PLT) and 18 liver resection prior to secondary liver transplantation (SLT) for recurrence (n = 11), deterioration of liver function (n = 4), or high risk for recurrence (n = 3). Perioperative and postoperative factors and long-term survival were compared. RESULTS: Comparison of PLT and SLT groups at the time of LT revealed similar median age (53 vs. 55 years), sex, and etiology of liver disease (alcohol/viral B/C/other). In the SLT group, the mean time between liver resection and listing for LT was 20 months (range 1–84 months). Overall time on LT waiting list of the two groups was similar (3 vs. 5 months). Pathologic analysis after LT revealed similar tumor size (2.2 vs. 2.3 cm) and number (1.6 vs. 1.7). Perioperative and postoperative courses were not different in terms of operative time (551 vs. 530 minutes), blood loss (1191 vs. 1282 mL), transfusion (3 vs. 2 units), ICU (9 vs. 10 days) or hospital stay (32 vs. 31 days), morbidity (51% vs. 56%) or 30-day mortality (5.7% vs. 5.6%). During a median follow-up of 32 months (3 to 158 months), 3 patients recurred after PLT and one after SLT. After transplantation, 3- and 5-year overall survivals were not different between groups (82 vs. 82% and 59 vs. 61%). CONCLUSIONS: In selected patients, liver resection prior to transplantation does not increase the morbidity or impair long-term survival following LT. Therefore, liver resection prior to transplantation can be integrated in the treatment strategy for HCC

The B73 maize genome: Complexity, diversity, and dynamics

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylationpoor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize

The B73 maize genome: complexity, diversity, and dynamics

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize

Catching Element Formation In The Act. The Case for a New MeV Gamma-Ray Mission: Radionuclide Astronomy in the 2020s. A White Paper for the 2020 Decadal Survey

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions