Ordered Measurements of Permutationally-Symmetric Qubit Strings

We show that any sequence of measurements on a permutationally-symmetric (pure or mixed) multi-qubit string leaves the unmeasured qubit substring also permutationally-symmetric. In addition, we show that the measurement probabilities for an arbitrary sequence of single-qubit measurements are independent of how many unmeasured qubits have been lost prior to the measurement. Our results are valuable for quantum information processing of indistinguishable particles by post-selection, e.g. in cases where the results of an experiment are discarded conditioned upon the occurrence of a given event such as particle loss. Furthermore, our results are important for the design of adaptive-measurement strategies, e.g. a series of measurements where for each measurement instance, the measurement basis is chosen depending on prior measurement results.Comment: 13 page

Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts

Despite the ubiquity of chemoautotrophic symbioses at hydrothermal vents, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of vent snail, in which specific host–symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts' metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts' interaction with regional-scale differences in geochemistry

Estimated GFR and the Effect of Intensive Blood Pressure Lowering after Acute Intracerebral Hemorrhage

Background: The kidney-brain interaction has been a topic of growing interest. Past studies of the effect of kidney function on intracerebral hemorrhage (ICH) outcomes have yielded inconsistent findings. Although the second, main phase of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2) suggests the effectiveness of early intensive blood pressure (BP) lowering in improving functional recovery after ICH, the balance of potential benefits and harms of this treatment in those with decreased kidney function remains uncertain. Study Design: Secondary analysis of INTERACT2, which randomly assigned patients with ICH with elevated systolic BP (SBP) to intensive (target SBP < 140 mm Hg) or contemporaneous guideline-based (target SBP < 180 mm Hg) BP management. Setting & Participants: 2,823 patients from 144 clinical hospitals in 21 countries. Predictors Admission estimated glomerular filtration rates (eGFRs) of patients were categorized into 3 groups based on the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation: normal or high, mildly decreased, and moderately to severely decreased (>90, 60-90, and <60 mL/min/1.73 m2, respectively). Outcomes: The effect of admission eGFR on the primary outcome of death or major disability at 90 days (defined as modified Rankin Scale scores of 3-6) was analyzed using a multivariable logistic regression model. Potential effect modification of intensive BP lowering treatment by admission eGFR was assessed by interaction terms. Results: Of 2,623 included participants, 912 (35%) and 280 (11%) had mildly and moderately/severely decreased eGFRs, respectively. Patients with moderately/severely decreased eGFRs had the greatest risk for death or major disability at 90 days (adjusted OR, 1.82; 95% CI, 1.28-2.61). Effects of early intensive BP lowering were consistent across different eGFRs (P = 0.5 for homogeneity). Limitations: Generalizability issues arising from a clinical trial population. Conclusions: Decreased eGFR predicts poor outcome in acute ICH. Early intensive BP lowering provides similar treatment effects in patients with ICH with decreased eGFRs

Microbial indicators as a diagnostic tool for assessing water quality and climate stress in coral reef ecosystems

Microorganisms play a fundamental role in the functioning and stability of coral reef ecosystems. However, environmental disturbances can trigger alterations to the natural microbial community composition and their functional traits with potentially detrimental consequences for host organisms, such as corals, sponges and algae and concomitant implications for the entire coral reef ecosystem. Coral reefs are increasingly affected by localized impacts such as declining water quality and global pressures derived from human-induced climate change, which severely alters the natural conditions on reefs and can push dominating benthic life forms towards the limit of their resistance and resilience. Microorganisms can respond very rapidly to these altered environmental conditions so defining their natural variability over spatial and temporal gradients is critical for early and accurate identification of environmental disturbances. The rapid response of microbes to environmental change is likely to confer significant advantages over traditional reef monitoring methods, which are based on visual signs of health deterioration in benthic coral reef macroorganisms. This review discusses the potential of microbes as early warning indicators for environmental stress and coral reef health and proposes priorities for future research