Quantum energy flow in mesoscopic dielectric structures

We investigate the phononic energy transport properties of mesoscopic, suspended dielectric wires. The Landauer formula for the thermal conductance is derived and its universal aspects discussed. We then determine the variance of the energy current in the presence of a steady state current flow. In the final part, some initial results are presented concerning the nature of the temperature fluctuations of a mesoscopic electron gas thermometer due to the absorption and emission of wire phonons.Comment: 20 pages, 2 figures. Submitted to Phys. Rev.

Quantifying the levitation picture of extended states in lattice models

The behavior of extended states is quantitatively analyzed for two dimensional lattice models. A levitation picture is established for both white-noise and correlated disorder potentials. In a continuum limit window of the lattice models we find simple quantitative expressions for the extended states levitation, suggesting an underlying universal behavior. On the other hand, these results point out that the Quantum Hall phase diagrams may be disorder dependent.Comment: 5 pages, submitted to PR

Non-bee insects are important contributors to global crop pollination

Wild andmanaged bees arewell documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25-50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.Peer Reviewe

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

The impact of the Mid-Pleistocene Transition on the composition of submerged reefs of the Maui Nui Complex, Hawaii

The submarine reef terraces (L1–L12) of the Maui Nui Complex (MNC—the islands of Lanai, Molokai, Maui and\ud Kahoolawe) in Hawaii provide a unique opportunity to investigate the impact of climate and sea level change\ud on coral reef growth by examining changes in reef development through the Mid-Pleistocene Transition\ud (900–800 ka). We present an analysis of the biological and sedimentary composition of the reefs that builds\ud directly on recently published chronological and morphological data. We define nine distinct limestone facies\ud and place them in a spatial and stratigraphic context within 12 reef terraces using ROV and submersible\ud observations. These include oolitic, two coral reef, two coralline algal nodule, algal crust, hemi-pelagic mud,\ud bioclastic and peloidal mud facies. These facies characterise environments from high energy shallow water\ud coral reef crests to low energy non-reefal deep-water settings. Combining the bottom observations and\ud sedimentary facies data, we report a shift in the observed sedimentary facies across the submerged reefs of the\ud MNC from dominant shallow coral reef facies on the deep reefs to coralline algae dominated exposed outcrop\ud morphology on the shallower reefs. We argue that this shift is a reflection of the change in period and\ud amplitude of glacioeustatic sea level cycles (41 kyr and 60–70 m to 100 kyr and 120 m) during the Mid-\ud Pleistocene Transition (MPT, ~800 ka), coupled with a slowing in the subsidence rate of the complex. The\ud growth of stratigraphically thick coral reef units on the deep Pre-MPT reefs was due to the rapid subsidence of\ud the substrate and the shorter, smaller amplitude sea level cycles allowing re-occupation and coral growth on\ud successive cycle low-stands. Longer, larger amplitude sea level cycles after the MPT combined with greater\ud vertical stability at this time produced conditions conducive to deep-water coralline algae growth which\ud veneered the shallower terraces. Additionally, we compare reef development both within the MNC, and\ud between the MNC and Hawaii. Finally we suggest that climatic forcings such as sea-surface temperature and\ud oceanographic currents may also have influenced the distribution of coral species within the sample suite, e.g.,\ud the disappearance of the Acropora genus from the Maui Nui Complex in the Middle Pleistocene

Febrile polyarthritis and cutaneous nodules. An unusual presentation of a pancreatitis.

A case report of hidden pancreatitis with severe polyarthritis and necrosis of subcutaneous fat is presented. A brief review of this syndrome in the literature is also given. © 1984 Springer-Verlag.Case ReportsJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe