Titania/alumina bilayer gate insulators for InGaAs metal-oxide-semiconductor devices

We describe the electrical properties of atomic layer deposited TiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> bilayer gate oxides which simultaneously achieve high gate capacitance density and low gate leakage current density. Crystallization of the initially amorphous TiO<sub>2</sub> film contributes to a significant accumulation capacitance increase (∼33%) observed after a forming gas anneal at 400 °C. The bilayer dielectrics reduce gate leakage current density by approximately one order of magnitude at flatband compared to Al<sub>2</sub>O<sub>3</sub> single layer of comparable capacitance equivalent thickness. The conduction band offset of TiO<sub>2</sub> relative to InGaAs is 0.6 eV, contributing to the ability of the stacked dielectric to suppress gate leakage conduction

A comparison of the polarization observables for the d(e, e\u27p) and P(e, e\u27p) reactions at quasi-free kinematics

Final-state recoil proton polarization observables were measured using the newly commissioned Proton Focal-Plane-Polarimeter at the MIT-Bates Linear Accelerator Center. This device permits access to a new class of electromagnetic spin observables. Measurements were made at two values of {dollar}{lcub}\cal Q{rcub}\sp2,{dollar} 0.38 and 0.50 (GeV/c){dollar}\sp2,{dollar} in the quasi-elastic region using the {dollar}d(\vec e,e\sp\prime\vec p)n{dollar} reaction in parallel kinematics with zero recoil momentum. Simultaneous measurements were also made using the {dollar}p(\vec e,e\sp\prime\vec p){dollar} reaction at the same kinematics allowing a precise comparison between the hydrogen and deuterium spin-dependent observables, {dollar}D\sb{lcub}LL{rcub}{dollar} and {dollar}D\sb{lcub}LT{rcub}{dollar} as well as the induced polarization {dollar}P\sb{lcub}n{rcub}.{dollar} In the elastic scattering limit the spin observables can be used to directly extract the ratio of {dollar}G\sbsp{lcub}E{rcub}{lcub}p{rcub}/G\sbsp{lcub}M{rcub}{lcub}p{rcub}.{dollar} Therefore, in the impulse approximation the results have direct bearing on the validity of approximations used to extract {dollar}G\sbsp{lcub}E{rcub}{lcub}n{rcub}/G\sbsp{lcub}M{rcub}{lcub}n{rcub}{dollar} for the neutron in analogous {dollar}d(\vec e,e\sp\prime\vec n)p{dollar} experiments. This comparison is also nearly free of systematic errors and is independent of both the beam polarization and the analyzing power of the {dollar}\sp{lcub}12{rcub}C(p,p\sp\prime){dollar} reaction. The results for deuterium are in good agreement with the hydrogen data and with the Plane-Wave-Impulse-Approximation theories of Arenhovel and Van Orden

Projections for future radiocarbon content in dissolved inorganic carbon in hardwater lakes: a retrospective approach

Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI14C data from 2013 and 1969 for Lake Constance reveals that this is not a valid assumption. We hypothesize that changes in atmospheric carbon contributions to lake water DIC have taken place due to anthropogenically forced eutrophication in the 20th century. A return to more oligotrophic conditions in the lake led to reoxygenation and enhanced terrigenous organic matter remineralization, contributing to lake water DIC. Such comparisons using DI14C measurements from different points in time enable nonlinear changes in lake water DIC source and signature to be disentangled from concurrent anthropogenically induced changes in atmospheric 14C. In the future, coeval changes in lake dynamics due to climate change are expected to further perturb these balances. Depending on the scenario, Lake Constance DI14C is projected to decrease from the 2013 measured value of 0.856 Fm to 0.54–0.62 Fm by the end of the century

The V_H repertoire and clonal diversification of B cells in inflammatory myopathies

The contribution of antigen-driven B-cell adaptive immune responses within the inflamed muscle of inflammatory myopathies (IMs) is largely unknown. In this study, we investigated the immunoglobulin VH gene repertoire, somatic hypermutation, clonal diversification, and selection of infiltrating B cells in muscle biopsies from IM patients (dermatomyositis and polymyositis), to determine whether B cells and/or plasma cells contribute to the associated pathologies of these diseases. The data reveal that Ig V<sub>H</sub> gene repertoires of muscle-infiltrating B cells deviate from the normal VH gene repertoire in individual patients, and differ between different types of IMs. Analysis of somatic mutations revealed clonal diversification of muscle-infiltrating B cells and evidence for a chronic B-cell response within the inflamed muscle. We conclude that muscle-infiltrating B cells undergo selection, somatic hypermutation and clonal diversification in situ during antigen-driven immune responses in patients with IMs, providing insight into the contribution of B cells to the pathological mechanisms of these disorders

Nephritis in the dog associated with Leptospira canicola infection

369 dogs infected with Leptospira canicola have been examined clinically. Agglutination tests and blood urea estimations have been carried out on each case. Details of examinations are given in the appendices. The cases have been classified into two main groups, primary and secondary renal, according to the agglutination titres and these two groups have been subdivided according to the degree of nitro- gen retention as evidenced by blood urea levels. Seven primary cases were shown to have a leptospiral bacteraemia in the early stage. 46 of the primary cases were kept under observation for periods of six months to four years, during which time agglutinins against L. canicola persisted as did proteinuria and the excretion of tubular casts.In Section 2 the renal lesions associated with L. cani- cola infection are described. The primary renal stage was characterised by an intense interstitial cellular infiltration which often localised predominantly in the corticomedullary zone. In subacute stages early fibrosis was evident but the infiltration remained the chief feature. In well established cases of chronic nephritis in the secondary stage the main lesion was extensive diffuse fibrosis with comparatively few small cellular foci remaining. Spirochaetes were sparse but were demonstrated mostly within the lumen of tubules or in the substance of a hyaline cast.In the experimental work described in Section 3 Koch's postulates have been fulfilled by reproducing the infection in dogs and recovering the organism in pure culture from the blood and kidneys of the infected animal. The recovered organism was then passaged through another two dogs. The renal lesions produced were similar to those observed in naturally occurring primary cases although not sufficiently extensive to produce obvious malaise or nitrogen retention in the dogs infected. It is suggested that loss of virulence of the organism in vitro is the main reason for the inability to produce renal failure. Despite the lack of severity of the condition produced in the dog the cellular infiltration was characteristically mononuclear and showed a definite tendency to localise in the boundary zone. Spirochaetes were readily demonstrated in the kidneys

Widespread dispersal and aging of organic carbon in shallow marginal seas

The occurrence of pre-aged organic carbon (OC) in continental margin surface sediments is a commonly observed phenomenon, yet the nature, sources, and causes of this aged OC remain largely undetermined for many continental shelf settings. Here we present the results of an extensive survey of the abundance and radiocarbon content of OC in surface sediments from the northern Chinese marginal seas. Pre-aged OC is associated with both coarser (>63 µm) and finer (<63 µm) sedimentary components; measurements on specific grain-size fractions reveal that it is especially prevalent within the 20–63 µm fraction of inner shelf sediments. We suggest that organic matter associated with this sortable silt fraction is subject to protracted entrainment in resuspension-deposition loops during which it ages, is modified, and is laterally dispersed, most likely via entrainment within benthic nepheloid layers. This finding highlights the complex dynamics and predepositional history of organic matter accumulating in continental shelf sediments, with implications for our understanding of carbon cycling on continental shelves, development of regional carbon budgets, and interpretation of sedimentary records

Temporal variability in composition and fluxes of Yellow River particulate organic matter

This study examines temporal variations of the abundance and carbon isotopic characteristics of particulate organic carbon (POC) and specific-source compounds in the context of hydrological variability in the Yellow River. The content and bulk carbon isotopic characteristics (13C and 14C) of POC were relatively uniform over the hydrologic (seasonal) cycle. We attribute these temporally invariant geochemical characteristics to the dominant contribution of loess material to the suspended particulate matter (SPM). In contrast, molecular-level signals revealed that hydrologic conditions exert a significant influence on the proportional contributions of petrogenic and especially fresh plant-derived OC, while pre-aged soil OC is mobilized via deeper erosion processes (e.g., gully erosion, mudslides) and is independent of hydrodynamics and surface runoff. A coupled biomarker-isotope mixing model was applied to estimate the time-varying supply of contemporary/modern biomass, pre-aged soil, and fossil OC components to Chinese marginal seas from the Yellow River. We found that natural (e.g., precipitation) and human-induced (e.g., water and sediment regulation) variations in hydrological regime strongly influence the flux with the magnitude of the corresponding annual fluxes of POC ranging between 0.343 ± 0.122 Mt yr−1 and 0.581 ± 0.213 Mt yr−1, but less strongly infleunce proportions of the different OC constituents. Inter-annual differences in pre-aged soil and fossil OC fluxes imply that extreme climate events (e.g., floods) modulate the exhumation and export of old carbon to the ocean, but the OC homogeneity in the pre-aged mineral soil-dominated watersheds facilitates robust predictions in terms of OC transport dynamics in the past (sediment cores) and in the future

Hydrologic controls on seasonal and inter-annual variability of Congo River particulate organic matter source and reservoir age

We present dissolved organic carbon (DOC) concentrations, particulate organic matter (POM) composition (δ13C, δ15N, ∆14C, N/C), and particulate glycerol dialkyl glycerol tetraether (GDGT) distributions from a 34-month time-series near the mouth of the Congo River. An end-member mixing model using δ13C and N/C indicates that exported POM is consistently dominated by C3 rainforest soil sources, with increasing contribution from C3 vegetation and decreasing contribution from phytoplankton at high discharge. Large C4 inputs are never observed despite covering ≈ 13% of the catchment. Low and variable ∆14C values during 2011 [annual mean = (− 148 ± 82) ‰], when discharge from left-bank tributaries located in the southern hemisphere reached record lows, likely reflect a bias toward pre-aged POM derived from the Cuvette Congolaise swamp forest. In contrast, ∆14C values were stable near − 50‰ between January and June 2013, when left-bank discharge was highest. We suggest that headwater POM is replaced and/or diluted by C3 vegetation and pre-aged soils during transit through the Cuvette Congolaise, whereas left-bank tributaries export significantly less pre-aged material. GDGT distributions provide further evidence for seasonal and inter-annual variability in soil provenance. The cyclization of branched tetraethers and the GDGT-0 to crenarchaeol ratio are positively correlated with discharge (r ≥ 0.70; p-value ≤ 4.3 × 10− 5) due to the incorporation of swamp-forest soils when discharge from right-bank tributaries located in the northern hemisphere is high. Both metrics reach record lows during 2013, supporting our interpretation of increased left-bank contribution at this time. We conclude that hydrologic variability is a major control of POM provenance in the Congo River Basin and that tropical wetlands can be a significant POM source despite their small geographic coverage

A Laser System for the Spectroscopy of Highly-Charged Bismuth Ions

We present and characterize a laser system for the spectroscopy on highly-charged ^209Bi^82+ ions at a wavelength of 243.87 nm. For absolute frequency stabilization, the laser system is locked to a near-infra-red laser stabilized to a rubidium transition line using a transfer cavity based locking scheme. Tuning of the output frequency with high precision is achieved via a tunable rf offset lock. A sample-and-hold technique gives an extended tuning range of several THz in the UV. This scheme is universally applicable to the stabilization of laser systems at wavelengths not directly accessible to atomic or molecular resonances. We determine the frequency accuracy of the laser system using Doppler-free absorption spectroscopy of Te_2 vapour at 488 nm. Scaled to the target wavelength of 244 nm, we achieve a frequency uncertainty of \sigma_{244nm} = 6.14 MHz (one standard deviation) over six days of operation.Comment: Contribution to the special issue on "Trapped Ions" in "Applied Physics B

Can a witness report hearsay evidence unintentionally? The effects of discussion on eyewitness memory

When eyewitnesses are exposed to misinformation about an event from a co-witness, they often incorporate this misinformation in their recall of the event. The current research aimed to investigate whether this memory conformity phenomenon is due to change in the witness's memory for the event, or to social pressures to conform to the co-witness's account. Participants were shown a crime video and then asked to discuss the video in groups, with some receiving misinformation about the event from their discussion partners. After a one week delay some participants were warned about possible misinformation before all participants provided their own account of the event. In Study 1, participants made remember/know judgments about the items recalled, and in Study 2 they indicated the source of their memories. Co-witness information was incorporated into participants' testimonies, and this effect was not reduced by warnings or source monitoring instructions, suggesting memory change may have occurred. However, there was some indication that remember/know judgments may help distinguish between "real" memories and co-witness information