Microbial mineral weathering has been predominantly investigated at shallow depths in humid and tropical environments. Much less is understood about its role in the deeper subsurface of arid and semi-arid environments where microbial weathering is limited by the availability of water and energy sources for microbial metabolism. However, the deep subsurface in these climate zones may host a microbial community that thrives on weathering of iron (Fe)-bearing minerals that serve as electron donors or acceptors.

To investigate the role of microorganisms in weathering of Fe-bearing minerals in a dry climate, we recovered a >80 m deep weathering profile in a semi-arid region of the Chilean Coastal Cordillera. The bedrock is rich in Fe-bearing minerals (hornblende, biotite, chlorite, magnetite and hematite) but lacks detectable organic carbon. We evaluated the bioavailability of Fe(III)-bearing minerals that may serve as an electron acceptor for Fe(III)-reducing microorganisms. Using geochemical, mineralogical and cultivation-based methods, we found enhanced Fe bioavailability and more in vitro microbial Fe(III) reduction at increased depth. We obtained an Fe(III)-reducing enrichment culture from the deepest weathered rock found at 77 m depth. This enrichment culture is capable of reducing ferrihydrite (up to 0.6 mM d–1) using lactate or dihydrogen as an electron donor and grows at circumneutral pH. The main organism in the enrichment culture is the spore-forming Desulfotomaculum ruminis (abundance of 98.5%) as revealed by 16S rRNA gene amplicon sequencing.

Our findings provide evidence for a microbial contribution to the weathering of Fe-bearing minerals in semi-arid environments. While microorganisms are probably not contributing to the weathering of Fe(II)-bearing silicate minerals, they are most likely of importance regarding reductive dissolution of secondary weathering products. The Fe(III) reduction quantified in this weathering profile by the in situ microbial community suggests that microorganisms are active weathering agents in semi-arid climates.

Party competition is foundational to the study of modern politics, affecting outcomes as varied as policy choices, political participation, and the quality of representation. Scholars have long argued that increased levels of party competition are associated with more liberal policy making. By this logic, parties in close competition with one another try to expand their bases of support by catering to the desires of those who tend to abstain from the political process—the “have-nots.” We extend this classic hypothesis by examining the relationship between competition and policy liberalism over several decades, articulating and testing a theory that suggests that party competition relates differently to social and economic policy liberalism. We find robust evidence that increased competition has a positive relationship with economic policy liberalism, weaker evidence for a negative relationship between competition and social policy liberalism, and suggestive evidence that the direction and magnitudes of these relationships have changed over time.

Cognitive deficits are viewed as core symptoms and among the major disabilities of schizophrenia. Among these deficits, memory impairments are likely to play a crucial role, and more specifically, memory for personal episodes, is disproportionately impaired. Schizophrenia is associated with a reduction of specific autobiographical memories which are marked after the onset of the disease (e.g., Riutort et al., 2003). This impairment is consistent with the existence of an abnormal development of personal identity in patients with schizophrenia. Williams and colleagues (1996) suggest that the specificity with which people retrieve episodes from their past determines the specificity with which they imagine the future. The aim of the present study was to investigate this hypothesis in patients with schizophrenia. A French adaptation of the Autobiographical Memory Test (AMT, Williams & Broadbent, 1986) was administrated to 12 patients with schizophrenia (4 men) and 12 control participants. In this version (TeMA, Neumann & Philippot, 2006), participants had to recollect specific past events or to imagine specific future scenarios in response to cue words. Results showed that patients retrieved fewer specific autobiographical memories and generated fewer specific future events than controls. In addition, their difficulty to imagine the future was correlated to their lack of specificity in the retrieval of past memories. The possibility that memory impairments could affect imageability of the future might have central clinical implications. Indeed, it suggests that cognitive deficits may play an important role in the feelings of hopelessness about the future often encountered in schizophrenia.

A G4C2 repeat extension in the first intron of C9ORF72 is the most common cause of familial frontotemporal dementia with and without motoneuron disease or atypical Parkinsonism. We recently found that the characteristic p62 positive/TDP43 negative neuronal cytoplasmic inclusions (NCIs) mainly seen in cerebellum und hippocampus consist of different dipeptide repeat proteins (DPRs) generated by an ATG independent translation of stable sense and antisense transcripts of the extended intron.

After creating specific antibodies against all potential DPRs resulting from different reading frames, we investigated their regional and cellular distribution pattern in the central nervous system of autopsy cases with C9ORF72 mutation by immunohistochemistry.

Aggregates of all DPRs were seen in neuronal cell bodies and processes. Glycine-alanine and glycine-prolin DPRs dominated. NCIs were abundant in all neocortical areas, in the hippocampal formation and in cerebellum, less frequent in subcortical nuclei, and rare in brain stem and spinal cord following a rostro-caudal gradient. Different DPRs were found in the same NCI. The regional distribution pattern of NCIs was similar in all clinical subtypes, and did not directly correlate with neurodegeneration. DPRs and TDP43 that usually also aggregates in C9ORF72 mutation cases were rarely co-localized in the same NCI. In case of co-localization DPR proteins formed a central core surrounded by TDP43.

The detection of DPR inclusions directly connects the mutation with specific neuropathological alterations. The formation of DPR inclusions seems to precede the formation of TDP43 inclusions. If there is a neurotoxic effect of DPRs, DPR inclusions might be neuroprotective.

We introduce the Galaxy IFU Spectroscopy Tool (GIST), a convenient, all-in-one and multi-purpose tool for the analysis and visualisation of already reduced (integral-field) spectroscopic data. In particular, the pipeline performs all steps from read-in and preparation of data to its scientific analysis and visualisation in publication-quality plots. The code measures stellar kinematics and non-parametric star formation histories using the pPXF routine (Cappellari & Emsellem 2004; Cappellari 2017), performs an emission-line analysis with the GandALF procedure (Sarzi et al. 2006; Falcón-Barroso et al. 2006), and determines absorption line-strength indices and their corresponding single stellar population equivalent population properties (Kuntschner et al.2006; Martín-Navarro et al. 2018). The dedicated visualisation routine Mapviewer facilitates the access of all data products in a sophisticated graphical user interface with fully interactive plots.

The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high-intensity interaction when using a regular structure with known spacing.

The U.S. Science Plan for Deep Ice Coring in West Antarctica calls for two ice cores to be collected. the first of these cores, from Siple Dome, was completed during the 1997/98 field season. the second core is to be collected from a site near the divide that separates ice flowing to the Ross Sea and to the Amundsen Sea.Using high-resolution, grid-based aerogeophysical surveys of the Ross/Amundsen ice-divide region, we identify seven candidate sites and assess their suitability for deep coring. We apply ice-flow and temperature calculations to predict time-scales and annual-layer resolution, and to assess the potential for basal melting for several selected sites. We conclude that basal melting is likely for sites with very thick ice, as was observed at the Byrd core site. Nevertheless, these sites are most attractive for coring since they promise recovery of a long climate record with comparatively high time resolution during the last glacial period.

Stable isotopes in ice cores are used as a proxy for the temperature at the time of snow formation. Where net accumulation rate is relatively high, snow is buried quickly and initial isotopic values are preserved. However, in low-accumulation areas, snow is exposed to lengthy vapor exchange with the atmosphere. the original isotopic signature of this snow may be modified by equilibration with atmospheric water vapor in the boundary layer over the snow surface in summer. We estimate the characteristic times for equilibration by using an electrical resistor network analogue. Warm, windy summers and low accumulation rate enhance equilibration. Although equilibration of the complete snowpack is unlikely, significant post-depositional change may occur in some Antarctic environments.

The spatial pattern of accumulation rate can be inferred from internal layers in glaciers and ice sheets. Non-dimensional analysis determines where finite strain can be neglected (‘shallow-layer approximation’) or approximated with a local one-dimensional flow model (‘local-layer approximation’), and where gradients in strain rate along particle paths must be included (‘deep layers’). We develop a general geophysical inverse procedure to infer the spatial pattern of accumulation rate along a steady-state flowband, using measured topography of the ice-sheet surface, bed and a ‘deep layer’. A variety of thermomechanical ice-flow models can be used in the forward problem to calculate surface topography and ice velocity, which are used to calculate particle paths and internal-layer shapes. An objective tolerance criterion prevents over-fitting the data. After making site-specific simplifications in the thermomechanical flow algorithm, we find the accumulation rate along a flowband through Taylor Mouth, a flank site on Taylor Dome, Antarctica, using a layer at approximately 100 m depth, or 20% of the ice thickness. Accumulation rate correlates with ice-surface curvature. At this site, gradients along flow paths critically impact inference of both the accumulation pattern, and the depth-age relation in a 100 m core.

Persistent katabatic winds form widely distributed localized areas of near-zero net surface accumulation on the East Antarctic ice sheet (EAIS) plateau. These areas have been called 'glaze' surfaces due to their polished appearance. They are typically 2-200 km2 in area and are found on leeward slopes of ice-sheet undulations and megadunes. Adjacent, leeward high-accumulation regions (isolated dunes) are generally smaller and do not compensate for the local low in surface mass balance (SMB). We use a combination of satellite remote sensing and field-gathered datasets to map the extent of wind glaze in the EAIS above 1500 m elevation. Mapping criteria are derived from distinctive surface and subsurface characteristics of glaze areas resulting from many years of intense annual temperature cycling without significant burial. Our results show that 11.2 ± 1.7%, or 950 ± 143 × 103km2, of the EAIS above 1500 m is wind glaze. Studies of SMB interpolate values across glaze regions, leading to overestimates of net mass input. Using our derived wind-glaze extent, we estimate this excess in three recent models of Antarctic SMB at 46-82 Gt. The lowest-input model appears to best match the mean in regions of extensive wind glaze.

The late-Holocene trends in δ18O differ significantly in two ice cores (30 km apart) from the area of Taylor Dome, Antarctica. It is unlikely that the trend in the core from Taylor Mouth (the flank site) is due to a standard δ18O–surface temperature relationship. Assuming that the Taylor Dome (nearsummit) core records local climate variations common to both cores, we assess two leading possible causes for the observed differences: (1) Relative to Taylor Dome, Taylor Mouth may collect snow from more sources with distinct isotopic compositions. (2) Vapor motion during prolonged near-surface exposure may cause post-depositional isotope enrichment at Taylor Mouth, where the accumulation rate is low. Our model of firn pore-space vapor and sublimating ice grains suggests that post-depositional processes can modify δ18O values by several ‰. Isotopic samples from areas with significantly different accumulation rates near Taylor Mouth could differentiate between possibilities (1) and (2).

A new model of isotopic diffusion in the upper few meters of firn tracks the isotopic composition of both the ice matrix and the pore-space vapor through time in two dimensions. Stable isotopes in the vapor phase move through the firn by diffusion along concentration gradients and by advection. Wind-driven ventilation carries atmospheric water vapor into the firn, where it mixes with existing pore-space vapor. Unlike previous models, our model allows disequilibrium between pore-space vapor and the surrounding snow grains. We also calculate the isotopic effects of ventilation-driven sublimation and condensation in the firn. Model predictions of isotopic diffusion in firn compare favorably with existing diffusion models. Model results quantify what other investigators have suggested: isotopic change in the upper few meters is more rapid than can be explained by the Whillans and Grootes (1985) model; isotopic equilibration with atmospheric vapor is an important component of post-depositional isotopic change; and ventilation enhances isotopic exchange by creating regions of relatively rapid sublimation and condensation in the firn.

Objectives: The Centers for Medicare and Medicaid Services (CMS) issues National Coverage Determinations (NCDs) for medical interventions expected to have a significant impact on Medicare, the health insurance program for US citizens aged 65 years and older and certain people with disabilities under the age of 65 years. The objective of this study was to evaluate NCDs issued from 1999 to 2013 to identify key trends, and to discuss implications for future CMS policy.

Methods: We used the Tufts Medical Center Medicare National Coverage Determination Database to examine characteristics of NCDs from 1999 through 2013. We examined various characteristics of NCDs, including: whether the intervention under review is used for prevention or treatment of disease, the type of intervention considered, evidence limitations cited by CMS, and coverage determination outcome. We evaluated longitudinal trends in categorical and continuous variables in the database, using Cochran-Armitage trend tests and linear regression, respectively.

Results: We found that NCDs increasingly focus on preventive care (p = 0.072), pertain to diagnostic imaging (p = 0.033), and evaluate health education/behavioral therapy interventions (p = 0.051). CMS increasingly cites the lack of relevant outcomes (p = 0.019) and the lack of applicability of study results to the Medicare population (p < 0.001) as evidence limitations. CMS less often restricts coverage to certain population subgroups in NCDs (p < 0.001), but increasingly applies coverage with evidence development policies (p < 0.001).

Conclusions: Identified trends reflect broader changes in Medicare as CMS shifts its focus from treatment to prevention of disease, addresses potentially overutilized technologies, and attempts to issue flexible coverage policies.