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The ParABS system is essential for prokaryotic chromosome segregation. After loading at parS on the genome, ParB (partition protein B) proteins rapidly redistribute to distances of ~15 kilobases from the loading site. It has remained puzzling how this large-distance spreading can occur along DNA loaded with hundreds of proteins. Using in vitro single-molecule fluorescence imaging, we show that ParB from Bacillus subtilis can load onto DNA distantly of parS, as loaded ParB molecules themselves are found to be able to recruit additional ParB proteins from bulk. Notably, this recruitment can occur in cis but also in trans, where, at low tensions within the DNA, newly recruited ParB can bypass roadblocks as it gets loaded to spatially proximal but genomically distant DNA regions. The data are supported by molecular dynamics simulations, which show that cooperative ParB-ParB recruitment can enhance spreading. ParS-independent recruitment explains how ParB can cover substantial genomic distance during chromosome segregation, which is vital for the bacterial cell cycle.

Monitoring of the periglacial environment is relevant for many disciplines including glaciology, natural hazard management, geomorphology, and geodesy. Since October 2022, Rock Glacier Velocity (RGV) is a new Essential Climate Variable (ECV) product within the Global Climate Observing System (GCOS). However, geodetic surveys at high elevation remain very challenging due to environmental and logistical reasons. During the past decades, the introduction of low-cost global navigation satellite system (GNSS) technologies has allowed us to increase the accuracy and frequency of the observations. Today, permanent GNSS instruments enable continuous surface displacement observations at millimetre accuracy with a sub-daily resolution. In this paper, we describe decennial time series of GNSS observables as well as accompanying meteorological data. The observations comprise 54 positions located on different periglacial landforms (rock glaciers, landslides, and steep rock walls) at altitudes ranging from 2304 to 4003 and spread across the Swiss Alps. The primary data products consist of raw GNSS observables in RINEX format, inclinometers, and weather station data. Additionally, cleaned and aggregated time series of the primary data products are provided, including daily GNSS positions derived through two independent processing tool chains. The observations documented here extend beyond the dataset presented in the paper and are currently continued with the intention of long-term monitoring. An annual update of the dataset, available at https://doi.org/10.1594/PANGAEA.948334 (Beutel et al., 2022), is planned. With its future continuation, the dataset holds potential for advancing fundamental process understanding and for the development of applied methods in support of e.g. natural hazard management., Earth System Science Data, 14 (11), ISSN:1866-3516, ISSN:1866-3508

Temperature measurements in boreholes are the most common method allowing the quantitative and direct observation of permafrost evolution in the context of climate change. Existing boreholes and monitoring networks often emerged in a scientific context targeting different objectives and with different setups. A standardized, well-planned and robust instrumentation of boreholes for long-term operation is crucial to deliver comparable, high-quality data for scientific analyses and assessments. However, only a limited number of guidelines are available, particularly for mountain regions. In this paper, we discuss challenges and devise best practice recommendations for permafrost temperature measurements at single sites as well as in a network, based on two decades of experience gained in the framework of the Swiss Permafrost Monitoring Network PERMOS. These recommendations apply to permafrost observations in mountain regions, although many aspects also apply to polar lowlands. The main recommendations are (1) to thoroughly consider criteria for site selection based on the objective of the measurements as well as on preliminary studies and available data, (2) to define the sampling strategy during planification, (3) to engage experienced drilling teams who can cope with inhomogeneous and potentially unstable subsurface material, (4) to select standardized and robust instrumentation with high accuracy temperature sensors and excellent long-term stability when calibrated at 0°C, ideally with double sensors at key depths for validation and substitution of questionable data, (5) to apply standardized maintenance procedures allowing maximum comparability and minimum data processing, (6) to implement regular data control procedures, and (7) to ensure remote data access allowing for rapid trouble shooting and timely reporting. Data gaps can be avoided by timely planning of replacement boreholes. Recommendations for standardized procedures regarding data quality documentation, processing and final publication will follow later., Frontiers in Earth Science, 9, ISSN:2296-6463

PURPOSE: Inhomogeneities in the static magnetic field (B0 ) deteriorate MRSI data quality by lowering the spectral resolution and SNR. MRSI with low spatial resolution is also prone to lipid bleeding. These problems are increasingly problematic at ultra-high fields. An approach to tackling these challenges independent of B0 -shim hardware is to increase the spatial resolution. Therefore, we investigated the effect of improved spatial resolution on spectral quality and quantification at 4 field strengths. METHODS: Whole-brain MRSI data was simulated for 3 spatial resolutions and 4 B0 s based on experimentally acquired MRI data and simulated free induction decay signals of metabolites and lipids. To compare the spectral quality and quantification, we derived SNR normalized to the voxel size (nSNR), linewidth and metabolite concentration ratios, their Cramer-Rao-lower-bounds (CRLBs), and the absolute percentage error (APE) of estimated concentrations compared to the gold standard for the whole-brain and 8 brain regions. RESULTS: At 7T, we found up to a 3.4-fold improved nSNR (in the frontal lobe) and a 2.8-fold reduced linewidth (in the temporal lobe) for 1 cm3 versus 0.25 cm3 resolution. This effect was much more pronounced at higher and less homogenous B0 (1.6-fold improved nSNR and 1.8-fold improved linewidth in the parietal lobe at 3T). This had direct implications for quantification: the volume of reliably quantified spectra increased with resolution by 1.2-fold and 1.5-fold (when thresholded by CRLBs or APE, respectively). CONCLUSION: MRSI data quality benefits from increased spatial resolution particularly at higher B0 , and leads to more reliable metabolite quantification. In conjunction with the development of better B0 shimming hardware, this will enable robust whole-brain MRSI at ultra-high field.

Graphical abstract, Highlights • We demonstrated reliable and fast whole-brain 3D-MRSI of high-grade gliomas at 7T. • tCho, Gln, and Gly were increased in contrast-enhancing tumor tissue. • Results corresponded well to clinical data, but show more differentiated images. • We found cases of heterogeneity in metabolic images not visible in clinical imaging., Objectives Successful neurosurgical intervention in gliomas depends on the precision of the preoperative definition of the tumor and its margins since a safe maximum resection translates into a better patient outcome. Metabolic high-resolution imaging might result in improved presurgical tumor characterization, and thus optimized glioma resection. To this end, we validated the performance of a fast high-resolution whole-brain 3D-magnetic resonance spectroscopic imaging (MRSI) method at 7T in a patient cohort of 23 high-grade gliomas (HGG). Materials and methods We preoperatively measured 23 patients with histologically verified HGGs (17 male, 8 female, age 53 ± 15) with an MRSI sequence based on concentric ring trajectories with a 64 × 64 × 39 measurement matrix, and a 3.4 × 3.4 × 3.4 mm3 nominal voxel volume in 15 min. Quantification used a basis-set of 17 components including N-acetyl-aspartate (NAA), total choline (tCho), total creatine (tCr), glutamate (Glu), glutamine (Gln), glycine (Gly) and 2-hydroxyglutarate (2HG). The resultant metabolic images were evaluated for their reliability as well as their quality and compared to spatially segmented tumor regions-of-interest (necrosis, contrast-enhanced, non-contrast enhanced + edema, peritumoral) based on clinical data and also compared to histopathology (e.g., grade, IDH-status). Results Eighteen of the patient measurements were considered usable. In these patients, ten metabolites were quantified with acceptable quality. Gln, Gly, and tCho were increased and NAA and tCr decreased in nearly all tumor regions, with other metabolites such as serine, showing mixed trends. Overall, there was a reliable characterization of metabolic tumor areas. We also found heterogeneity in the metabolic images often continued into the peritumoral region. While 2HG could not be satisfyingly quantified, we found an increase of Glu in the contrast-enhancing region of IDH-wildtype HGGs and a decrease of Glu in IDH1-mutant HGGs. Conclusions We successfully demonstrated high-resolution 7T 3D-MRSI in HGG patients, showing metabolic differences between tumor regions and peritumoral tissue for multiple metabolites. Increases of tCho, Gln (related to tumor metabolism), Gly (related to tumor proliferation), as well as decreases in NAA, tCr, and others, corresponded very well to clinical tumor segmentation, but were more heterogeneous and often extended into the peritumoral region.

This project contains all the required material for the reproducibility of the results presented in the paper Tubini et. al 2020, "A method for solving heat transfer with phase change in ice or soil that allows for large time steps while guaranteeing energy conservation".

Eukaryotic cells employ three SMC (structural maintenance of chromosomes) complexes to control DNA folding and topology. The Smc5/6 complex plays roles in DNA repair and in preventing the accumulation of deleterious DNA junctions. To elucidate how specific features of Smc5/6 govern these functions, we reconstituted the yeast holo‐complex. We found that the Nse5/6 sub‐complex strongly inhibited the Smc5/6 ATPase by preventing productive ATP binding. This inhibition was relieved by plasmid DNA binding but not by short linear DNA, while opposing effects were observed without Nse5/6. We uncovered two binding sites for Nse5/6 on Smc5/6, based on an Nse5/6 crystal structure and cross‐linking mass spectrometry data. One binding site is located at the Smc5/6 arms and one at the heads, the latter likely exerting inhibitory effects on ATP hydrolysis. Cysteine cross‐linking demonstrated that the interaction with Nse5/6 anchored the ATPase domains in a non‐productive state, which was destabilized by ATP and DNA. Under similar conditions, the Nse4/3/1 module detached from the ATPase. Altogether, we show how DNA substrate selection is modulated by direct inhibition of the Smc5/6 ATPase by Nse5/6., Biochemical reconstitution and structural analyses provide insight into the architecture and substrate‐associated conformational changes of the yeast holo‐SMC5/6 complex.

Rock glaciers are slowly flowing mixtures of debris and ice occurring in mountains. They can represent a reservoir of water, and melting ice inside them can affect surface water hydrochemistry. Investigating the interactions between rock glaciers and water bodies is therefore necessary to better understand these mechanisms. With this goal, we elucidate the hydrology and structural setting of a rock glacier-marginal pond system, providing new insights into the mechanisms linking active rock glaciers and impounded surface waters. This was achieved through the integration of waterborne geophysical techniques (ground penetrating radar, electrical resistivity tomography and self-potentials) and heat tracing. Results of these surveys showed that rock glacier advance has progressively filled the valley depression where the pond is located, creating a dam that could have modified the level of impounded water. A sub-surface hydrological window connecting the rock glacier to the pond was also detected, where an inflow of cold and mineralised underground waters from the rock glacier was observed. Here, greater water contribution from the rock glacier occurred following intense precipitation events during the ice-free season, with concomitant increasing electrical conductivity values. The outflowing dynamic of the pond is dominated by a sub-surface seepage where a minor fault zone in bedrock was found, characterised by altered and highly-fractured rocks. The applied approach is evaluated here as a suitable technique for investigating logistically-complex hydrological settings which could be possibly transferred to wider scales of investigation.

Purpose Short‐echo‐time proton MR spectra at 7T feature nine to 10 distinct macromolecule (MM) resonances that overlap with the signals of metabolites. Typically, a metabolite‐nulled in vivo MM spectrum is included in the quantification`s prior knowledge to provide unbiased metabolite quantification. However, this MM model may fail if MMs are pathologically altered. In addition, information about the individual MM peaks is lost. In this study, we aimed to create an improved MM model by parameterization of the in vivo MM spectrum into individual components, and to use this new model to quantify free induction decay MR spectroscopic imaging (FID‐MRSI) data. Methods The measured in vivo MM spectrum was parameterized using advanced method for accurate, robust, and efficient spectral fitting (AMARES) and Hankel‐Lanczos singular value decomposition algorithms from which six different MM models were derived. Soft constraints were applied to avoid over‐parameterization. All MM models were combined with simulated metabolite spectra to form complete basis sets. FID‐MRSI data from 14 healthy volunteers were quantified via LCModel, and the results were compared between all basis sets. Results The MM model using nine individual AMARES‐parameterized MM components with additional soft constraints achieved the most reliable results. Nine MMs and seven metabolites were mapped simultaneously over the whole slice. Conclusion The proposed MM model may facilitate studies that involve patients with pathologically altered MMs. Magn Reson Med 79:1231–1240, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Proton MRS (1 H MRS) provides noninvasive, quantitative metabolite profiles of tissue and has been shown to aid the clinical management of several brain diseases. Although most modern clinical MR scanners support MRS capabilities, routine use is largely restricted to specialized centers with good access to MR research support. Widespread adoption has been slow for several reasons, and technical challenges toward obtaining reliable good-quality results have been identified as a contributing factor. Considerable progress has been made by the research community to address many of these challenges, and in this paper a consensus is presented on deficiencies in widely available MRS methodology and validated improvements that are currently in routine use at several clinical research institutions. In particular, the localization error for the PRESS localization sequence was found to be unacceptably high at 3 T, and use of the semi-adiabatic localization by adiabatic selective refocusing sequence is a recommended solution. Incorporation of simulated metabolite basis sets into analysis routines is recommended for reliably capturing the full spectral detail available from short TE acquisitions. In addition, the importance of achieving a highly homogenous static magnetic field (B0 ) in the acquisition region is emphasized, and the limitations of current methods and hardware are discussed. Most recommendations require only software improvements, greatly enhancing the capabilities of clinical MRS on existing hardware. Implementation of these recommendations should strengthen current clinical applications and advance progress toward developing and validating new MRS biomarkers for clinical use.

The PermaSense project is an ongoing interdisciplinary effort between geo-science and engineering disciplines started in 2006 with the goals to make observations possible that previously have not been possible. Specifically the aims are to obtain measurements data in unprecedented quantity and quality based on technological advances. This paper describes a unique ten+ year data record obtained from in-situ measurements in steep bedrock permafrost in an Alpine environment 5 on the Matterhorn Hörnligrat, Zermatt Switzerland at 3500 m a.s.l. Through the utilization of state-of-the-art wireless sensor technology it was possible to obtain more data of higher quality, make this data available in near real-time and tightly monitor and control the running experiments. This data set (DOI: doi.pangaea.de/10.1594/PANGAEA.897640, Weber et al., 2019a) constitutes the longest, densest and most diverse data record in the history of mountain permafrost research worldwide with 17 different sensor types used at 29 distinct sensor locations consisting of over 114.5 million data points captured over a period 10 of ten+ years. By documenting and sharing this data in this form we contribute to making our past research reproducible and facilitate future research based on this data e.g. in the area of analysis methodology, comparative studies, assessment of change in the environment, natural hazard warning and the development of process models., Earth System Science Data Discussions, ISSN:1866-3591

Figure S1. Illustration of the influence of logistic model parameters on curve, and the model fitted to a CKC. From left to right: Îą defines the asymmetry of the logistic model, Ď the steepness of the curve and k influences the terminal slope. The regression curve fitted to a given CKC for a malignant (blue) and a benign lesion (green). Figure S2. Boxplot of automatic segmentation performance in terms of Dice similarity coefficient (DSC). DWI, diffusion-weighted imaging; GI, Gini Importance; mRMR, minimum-Redundancy-Maximum-Relevance; PET, positron emission tomography; w/o, without. (DOCX 219 kb)

The cryosphere is defined by the presence of frozen water in its many forms: glaciers, ice caps, ice sheets, snow, permafrost, and river and lake ice. In the extended Hindu Kush Himalaya (HKH) region, including the Pamirs, Tien Shan and Alatua, the cryosphere is a key freshwater resource, playing a vital and significant role in local and regional hydrology and ecology. Industry, agriculture, and hydroelectric power generation rely on timely and sufficient delivery of water in major river systems; changes in the cryospheric system may thus pose challenges for disaster risk reduction in the extended HKH region.

Rock slope destabilization due to warming or thawing permafrost poses a risk to the safety of local communities and infrastructure in populated mountain regions. The analysis of fracture kinematics in the context of local temperature evolution in the longer-term is a common approach aiming to identify its forcing (e.g. Wegmann and Gudmundsson, 1999, Matsuoka and Murton, 2008, Blikra and Christiansen, 2014). Hasler et al. (2012) and Weber et al. (2017) analyzed fracture dilatation data measured at Matterhorn Hörnligrat at 3500 m a.s.l. and suggest thawing related processes, such as meltwater percolation into fractures to cause irreversible displacement. However, this finding so far has not been backed up by data from different instruments or analysis methods. Hence, misinterpretation of the existing data can not reliably be excluded. Based on further data consisting of surface displacements measured with D-GPS, inclinometers, ambient seismic vibrations and ground resistivity captured and compiled over a period of ten years, we apply a multi-data cross validation technique to detect and quantify temperature-induced rock slope dynamics and identify the components of derived process knowledge that predict behavior across differing observation methods. The combined analysis of this multi-modal dataset allows to further develop and analyse our limited understanding of the dominant processes governing rock slope stability, in our case a steep bedrock mountain permafrost buttress. Based on this evidence we conclude that the kinematics observed at the surface in the winter/refreezing period is negligible compared to those observed during spring initiated by the thawing and mobilization of fluid water w.r.t. destabilization and precursory signs of rockfall at a larger scale. Therefore, future research should focus on the quantification of water supply, distribution and mobility both in the frozen and fluid state.

Long echo time (TE) MR spectroscopy (MRS) sequences are sensitive only to metabolites of low molecular weight. At shorter TE, significantly more metabolite signals are detectable, including broad signals of high-molecular-weight macromolecules (MMs). Although the presence of MM resonances can bias metabolite quantification at short TE, proper quantification of MMs is important since MMs themselves may serve as potentially valuable biomarkers for many pathologies.We have therefore developed an FID-based 2D-MR Spectroscopic Imaging (2D-MRSI) sequence to map MMs in healthy brain tissue at 7T within a scan time of ~17min and a repetition time of 879ms. This 2D-MRSI technique provides MM maps over a whole slice (i.e., including cortical gray matter) at an ultra-short acquisition delay of 1.3ms, using double inversion for efficient nulling of low-molecular-weight metabolites.The optimal sequence parameters were estimated using Bloch simulations, phantom testing, and in vivo validation. The acquired in vivo MM spectra (n=6) included nine distinct MM peaks in the range of ~0.9–3.7ppm. The measured average MM spectrum was incorporated into the LCModel basis set and utilized for further quantification of MRSI data sets without metabolite nulling, which were acquired in five additional volunteers. The quantification results for two basis sets, one including the MMs and one without MM spectrum, were compared.Due to the high spectral resolution and full signal detection provided by the FID-MRSI sequence, we could successfully map five important brain metabolites. Most quantified metabolite signal amplitudes were significantly lower since the inclusion of MMs into the basis set corrected the overestimation of metabolite signals. The precision of fit (i.e., Cramér Rao lower bounds) remained unchanged. Our MM maps show that the overall MM contribution was higher in gray matter than in white matter.In conclusion, the acquired MM spectrum improved the accuracy of metabolite quantification and allowed the acquisition of high spatial resolution maps of five major brain metabolites and also MMs.

This work presents a new approach for high‐resolution MRSI of the brain at 7 T in clinically feasible measurement times. Two major problems of MRSI are the long scan times for large matrix sizes and the possible spectral contamination by the transcranial lipid signal. We propose a combination of free induction decay (FID)‐MRSI with a short acquisition delay and acceleration via in‐plane two‐dimensional generalised autocalibrating partially parallel acquisition (2D‐GRAPPA) with adiabatic double inversion recovery (IR)‐based lipid suppression to allow robust high‐resolution MRSI. We performed Bloch simulations to evaluate the magnetisation pathways of lipids and metabolites, and compared the results with phantom measurements. Acceleration factors in the range 2–25 were tested in a phantom. Five volunteers were scanned to verify the value of our MRSI method in vivo. GRAPPA artefacts that cause fold‐in of transcranial lipids were suppressed via double IR, with a non‐selective symmetric frequency sweep. The use of long, low‐power inversion pulses (100 ms) reduced specific absorption rate requirements. The symmetric frequency sweep over both pulses provided good lipid suppression (>90%), in addition to a reduced loss in metabolite signal‐to‐noise ratio (SNR), compared with conventional IR suppression (52–70%). The metabolic mapping over the whole brain slice was not limited to a rectangular region of interest. 2D‐GRAPPA provided acceleration up to a factor of nine for in vivo FID‐MRSI without a substantial increase in g‐factors (

Abweichender Titel nach ��bersetzung von der Verfasserin/des Verfassers

Figure S1. Sequencing and assembly strategy of the A. salmonicida subsp. pectinolytica strain 34mel genome. Figure S2. Gene similarity and Mummer alignments to other Aeromonas genomes. Figure S3. Transposon conglomerates from A. salmonicida subsp. pectinolytica strain 34mel. Figure S4. Transposon family content in analyzed Aeromonas strains. Figure S5. Comparison of the A. salmonicida subsp. pectinolytica strain 34mel genome, plasmid pFBAOT6 from Aeromonas caviae, and transposon Tn1721. Table S1. Pathogenic as well as temperature-dependent growth features of analyzed Aeromonas strains. Table S2. General genome features of A. salmonicida subsp. pectinolytica strain 34mel. Table S3. Polymorphic sites in rRNAs from A. salmonicida subsp. pectinolytica strain 34mel. Table S4. Genes disrupted by transposons in A. salmonicida subsp. pectinolytica strain 34mel. Table S5. Transposon details from analyzed Aeromonas strains. Table S6. Genes retained in transposon TnAs1 from the environmental IncP-9 TOL plasmid pWW0 from Pseudomonas putida. Text S1. Annotation details for RNA genes in the A. salmonicida subsp. pectinolytica strain 34mel genome. Text S2. Short unassigned contigs from the A. salmonicida subsp. pectinolytica strain 34mel draft genome. Text S3. Transposons: nomenclature and completeness. Text S4. On transposon counting and the meaning of â ISAs11â . Text S5. Insertions on pFBAOT6 in transposon Tn1721 and details of the regions shared with the A. salmonicida subsp. pectinolytica strain 34mel genome. Text S6. Details of PacBio library preparation, sequencing, and assembly of the genome from A. salmonicida subsp. pectinolytica strain 34mel. (PDF 1171 kb)

Item does not contain fulltext A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of (1)H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of (1)H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which (1)H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units. © RSNA, 2014 Online supplemental material is available for this article.

SummaryCondensin—an SMC-kleisin complex—is essential for efficient segregation of sister chromatids in eukaryotes [1–4]. In Escherichia coli and Bacillus subtilis, deletion of condensin subunits results in severe growth phenotypes and the accumulation of cells lacking nucleoids [5, 6]. In many other bacteria and under slow growth conditions, however, the reported phenotypes are much milder or virtually absent [7–10]. This raises the question of what role prokaryotic condensin might play during chromosome segregation under various growth conditions. In B. subtilis and Streptococcus pneumoniae, condensin complexes are enriched on the circular chromosome near the single origin of replication by ParB proteins bound to parS sequences [11, 12]. Using conditional alleles of condensin in B. subtilis, we demonstrate that depletion of its activity results in an immediate and severe defect in the partitioning of replication origins. Multiple copies of the chromosome remain unsegregated at or near the origin of replication. Surprisingly, the growth and chromosome segregation defects in rich medium are suppressed by a reduction of replication fork velocity but not by partial inhibition of translation or transcription. Prokaryotic condensin likely prevents the formation of sister DNA interconnections at the replication fork or promotes their resolution behind the fork.

International audience; Processes that control climate-dependent rockfall from permafrost-affected rock slopes are still poorly understood.In this study, we present the results of a Wireless Sensor Network, integrated within the Swiss project PermaSenseand developed in 2012, to measure rock temperature and geotechnical parameters in the steep rockwalls of theAiguille du Midi (AdM, 3842 m a.s.l., Mont Blanc massif, France). Accessible year round by cable car, the AdMcomprises two main peaks: (i) the Piton Nord with the cable car arrival station, where 4 crack-meters are placed onfour major fractures, and (ii) the Piton Central with many touristic infrastructure, equipped with three 10-m-deepboreholes with 15 temperatures sensors since 2009, and where 2 crack-meters are installed along a major fracture.Three major kinematic regimes are observed: (i) opening of clefts when the rock temperature becomes positive,followed by closing during the cold period, (ii) summer opening continued by a winter opening, and (iii) closingduring the warm period followed by opening in winter.

Summary Smc/ScpAB promotes chromosome segregation in prokaryotes, presumably by compacting and resolving nascent sister chromosomes. The underlying mechanisms, however, are poorly understood. Here, we investigate the role of the Smc ATPase activity in the recruitment of Smc/ScpAB to the Bacillus subtilis chromosome. We demonstrate that targeting of Smc/ScpAB to ParB/parS loading sites is strictly dependent on engagement of Smc head domains and relies on an open organization of the Smc coiled coils. We find that dimerization of the Smc hinge domain stabilizes closed Smc rods and hinders head engagement as well as chromosomal targeting. Conversely, the ScpAB sub-complex promotes head engagement and Smc rod opening and thereby facilitates recruitment of Smc to parS sites. Upon ATP hydrolysis, Smc/ScpAB is released from loading sites and relocates within the chromosome—presumably through translocation along DNA double helices. Our findings define an intermediate state in the process of chromosome organization by Smc., Graphical Abstract, Highlights • ATP-dependent head engagement is required for chromosomal targeting of Smc/ScpAB • ATP-dependent head engagement drives coiled-coil opening of Smc in vivo • Targeting of Smc/ScpAB to parS/ParB requires the head-proximal coiled coil of Smc • Hinge dimerization antagonizes head engagement, coiled-coil opening, and targeting, Smc/ScpAB is an important chromosome-organizing machine in bacteria. Minnen et al. show that targeting of Smc/ScpAB to chromosomal parS/ParB sites requires ATP-dependent engagement of Smc heads, which promotes disengagement of the Smc coiled coils and drives the complex into a targeting-competent open conformation.

In meiotic DNA recombination, the Hop2-Mnd1 complex promotes Dmc1-mediated single-stranded DNA (ssDNA) invasion into homologous chromosomes to form a synaptic complex by a yet-unclear mechanism. Here, the crystal structure of Hop2-Mnd1 reveals that it forms a curved rod-like structure consisting of three leucine zippers and two kinked junctions. One end of the rod is linked to two juxtaposed winged-helix domains, and the other end is capped by extra alpha-helices to form a helical bundle-like structure. Deletion analysis shows that the helical bundle-like structure is sufficient for interacting with the Dmc1-ssDNA nucleofilament, and molecular modeling suggests that the curved rod could be accommodated into the helical groove of the nucleofilament. Remarkably, the winged-helix domains are juxtaposed at fixed relative orientation, and their binding to DNA is likely to perturb the base pairing according to molecular simulations. These findings allow us to propose a model explaining how Hop2-Mnd1 juxtaposes Dmc1-bound ssDNA with distorted recipient double-stranded DNA and thus facilitates strand invasion.

vorgelegt von Stephan Gruber Graz, Univ., Dipl.-Arb., 2015

Despite the rising interest in mountain permafrost due to climatic changes and a noticed increase of registered rockfall events in the European Alps and other mountain ranges, little is known about transient thermal conditions in the detachment areas of rockfalls. Temperature conditions prior to the rockfall events of 144 past events in the European Alps were modelled with a physically based ground temperature model. To minimise the impact that uncertainty has on interpretations, only relative values were used, that is, percentiles obtained from cumulative distribution functions of the modelled ground surface temperatures from the beginning of the meteorological measurement series up to the event dates. Our results suggest that small and mid‐sized rockfalls (volumes up to 100 000 m3) from high elevation occurred mainly during short‐term periods of unusually high temperatures. This was neither found to be a result of the seasonal distribution (most analysed events in higher elevations occurred from July to September) nor of the longer‐term temporal distribution (most analysed events occurred after 2000) only. Plausible explanations are either a destabilisation related to advective thaw or failure due to stress redistribution caused by large temperature variations. Large deep‐seated rock slope failures (≥100 000 m3) in high elevation occurred all year round.

Poster; The steep rockwalls of the Mont Blanc massif have been affected by an increase in rockfall activity in the last decades. Permafrost degradation is suggested as the most likely triggering factor. To better understand geomorphic processes we investigate permafrost distribution and address questions on its pattern in steep alpine bedrock. We use GIS-modeling to simulate Mean Annual Rock Surface Temperature (MARST) distribution. Rock temperature measurements including three 10-m-deep borehole monitoring at the Aiguille du Midi (AdM, 3842 m a.s.l) serve to estimate the temperature offset (i.e. temperature difference between rock surface and depth of negligible inter-annual temperature varibility). The estimation of the lower extent of permafrost distribution is derived from a combination of both approaches and hypotheses on permafrost occurrence are evaluated with Electrical Resistivity Tomography (ERT) measurements. The MARST model indicates that the 0 °C isotherm extends down to 2600 m a.s.l in the most shaded faces and rises up to 3800 m in the most sun-exposed areas. According to recent literature and the AdM borehole thermal profiles, we postulate that permafrost could extends down below MARST reaching up to 3°C due to temperature offset processes. ERT measurements performed along 160-m-long profiles at six different sites which the top are located from 3360 m a.s.l to 2760 m a.s.l and the MARST range from 3°C are the first of this kind. Five of sites are located in the granite area making them directly comparable. They all show high resistivity values at depth (>200 k) interpreted as permafrost bodies. Lower resistivity values (< 90 k ) are found either above the high resistivity bodies and interpreted as thawed active layer, or below MARST warmer than 2-3°C and interpreted as non-perenially frozen rock. Two sites were measured in autumn 2012 and autumn 2013 allowing for time-lapse investigation which demonstrates the change in resistivity in repeated measurements. These preliminary results could confirm that steep alpine bedrock permafrost exists below surface tempera- ture reaching up to 3 °C. A temperature-resistivity calibration will be performed in a freezing laboratory at the Technical University of Munich to better assess ERT results and their interpretation in terms of permafrost occurrence and interannual changes

Poster, Geophysical Research Abstracts, 15, EGU2013-13058

We present a custom acoustic emission (AE) monitoring system designed to performlong-term measurements on high-alpine rock-walls. AE monitoring is a common tech-nique for characterizing damage evolution in solid materials. The system is based ona two-channel AE sensor node (AE-node) integrated into a Wireless Sensor Network (WSN) customized for operation in harsh environments. This wireless architecture of-fers flexibility in the deployment of AE-nodes at any position of the rock-wall that needsto be monitored, within a range of a few hundred meters from a core station connectedto the internet. The system achieves near real-time data delivery and allows the user toremotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock-wall, a special casing was developed.The monitoring system is completed by two probes that measure rock temperatureand liquid water content, both probes being also integrated into the WSN. We report afirst deployment of the monitoring system on a rock-wall at Jungfraujoch, 3500 ma.s.l.,Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the systemcould serve a number of other applications, including rock-fall hazard surveillance orstructural monitoring of concrete structures., Geoscientific Instrumentation, Methods and Data Systems Discussions, 2, ISSN:2193-0872

Diese Untersuchung fand im geographisch eigenen Kontext statt. Die Methode der „Anthropology at Home“ eröffnete mir dabei aber nicht nur Eigenes sondern auch Fremdes. Ganz im Gegensatz dazu wurden mir Lebensstile vermittelt, die ich nicht mein Eigen nennen kann. Dennoch habe ich über das Teilen von Ideen, zum Beispiel über den Zugang zur biologischen Landwirtschaft, manchmal in einen Dialog eintreten könne, der mich zum „Verwandten“ machte. Eingangs gibt die Arbeit einen Einblick in Region Waldviertel und in die materielle Kultur. Die materielle Kultur, hier auch als materielle Umwelt bezeichnet, hat Bedeutungen für die InterviewpartnerInnen. Sie ist gekennzeichnet durch das Wechselspiel zwischen materiellen Kräften und sozialen Beziehungen. Die sozialen Beziehungen gehen aus dem Umgang mit den Dingen hervor. Dinge sind eingebunden in sozialen Interaktionen. Sie stehen hier im Gegensatz zur traditionellen Herangehensweise der Anthropologie, die materielle Kultur als Zeichen und Symbole auffasst. Soziale Handlungen bedingen in dieser Ethnographie mehrere Dinge. Aus ihnen gehen geplante Kreationen, wie die Retraditionalisierung des Mohnanbaus hervor. Diese entstand durch die Gründung des Vereins für Sonderkulturen. Trotz des Bruches mit dem Mohnanbau in der ersten Hälfte des 20. Jahrhunderts wird der Mohnanbau in seiner Tradition als kontinuierlich betrachtet und gleichzeitig dabei völlig neu interpretiert. Die Produktion des Mohns als materielle Kraft führt zu sozialen Beziehungen und Handlungen. Im Mohndorf Armschlag zum Beispiel gibt es eine Reihe an Festtagen, bei denen die MohnproduzentInnen soziale Beziehungen jährlich erneuern und in eine Art Kommunikation mit ihren KonsumentInnen eingehen. Als Kommunikationsmedium dient auch die Landschaft. Neben den blühenden Mohnfeldern gibt es eigens angelegte Mohngärten und Wandertage. Diese Kommunikationsmedien zeigen, wie die Landschaft genutzt wird um die „Botschaft“ des Mohns zu verbreiten und sich zu repräsentieren. Ein weiterer Aspekt, der in Verbindung mit sozialen Handlungen steht, ist die Identitätsbildung, die hier als Prozess dargestellt wird. In der Kultur- und Sozialanthropologie wird, in der momentan gän-gigen Betrachtung, eher davon ausgegangen, dass Identitäten durch Abgrenzungen entstehen. Das geschieht durch Eigen- und Fremdzuschreibungen über bestimmte Kategorien. Handlungen gehen aber drüber hinaus. Sie können auch Einstellungen vermitteln und stellen in dieser Arbeit Lebensstile dar, die zum Beispiel über Ansichten mit Bezug zur biologischen Landwirtschaft einhergehen. Neben den Auswirkungen von materiellen Kräften auf soziale Beziehungen legt die Arbeit als zweiten Schwerpunkt ein Augenmerk auf den Produktionsprozess des Mohns. Es zeigt sich, dass der Mohnanbau von Energien der Umwelt und des Menschen geprägt ist. Der Zyklus des Mohnanbaus ist bestimmt durch die Planung der Fruchtfolge, den Anbau und die Ernte. Er ist mit unterschiedlichen Philosophien verknüpft. Bei der Düngung und Nährstoffproblematik gibt es unterschiedliche Zugangsweisen in der landwirt-schaftlichen Ausrichtung, die sich auch über den Umgang mit dem Boden definieren. Auch die Ernte ist mit Einstellungen verknüpft. Man hilft sich nicht nur gegenseitig in der Familie, sondern auch überbetrieblich. Die traditionelle Erntetechnik wird hoch gehalten und nur in Ausnahmefällen werden Mähdrescher eingesetzt. Das heißt, dass das Ernten in der Gemeinschaft nicht nur aus der Not heraus geschieht sondern eine bewusste Entscheidung und, vor allem im biologischen Landbau, mit einer Lebenseinstellung verbunden ist. Generell ist über das Wissen des dreiteiligen Anbauprozesses zu sagen, dass konventionell arbeitende BäuerInnen in der Regel auf agrarwissenschaftliche Erkenntnisse und biologisch arbeitende BäuerInnen viel auf eigenes Erfahrungswissen zurückgreifen. Schlussendlich zeigt die Arbeit, dass der weitere Weg des Mohns in Form von Verarbeitungstechni-ken und Vermarktungsstrategien vor allem auf Eigenlösungen der jeweiligen LandwirtInnen beruht. Die Praxis zeigt, dass das oft mit einem Mehraufwand verbunden ist aber auch Mehrwert hervorbringt. Es wird aber durchwegs klar, dass sich der Waldviertler Graumohn als Produkt auf den direktvermarkteten bäuerlichen Märkten in der Stadt und auf dem Land behaupten kann. Damit sind dem Waldviertler Graumohn gute Aussichten und ein besonderer Stellenwert innerhalb der agrarisch-österreichischen Produktpalette gesichert.

Durante el verano austral de 2008 se realizaron dos perforaciones en la cima del monte Reina Sofía (275 m snm) (628390S, 608210W) en las proximidades de la Base Antártica Española Juan Carlos I en la isla Livingston. Uno de ellos alcanzó una profundidad de 25m (PG-1, Permamodel-Gulbelkian-1) y el otro 15 m de profundidad (PG-2) ambas perforaciones se realizaron en roca cuarcita. En todos los casos se extrajo el testigo de la perforación para su posterior análisis físico, químico y biológico. Una vez realizados los sondeos fueron entubados en forma hermética para alojar en su interior las cadenas termométricas que registran en forma permanente la evolución temporal del gradiente térmico del suelo con periodo horario de registro de temperaturas. Presentamos en este trabajo los datos de temperaturas registrados durante 2008 en las perforaciones PG-1 y PG-2 a diferentes profundidades, tras su primer año de funcionamiento. De estos datos podemos evaluar la profundidad de amplitud térmica anual cero y su temperatura, así como el gradiente térmico y una primera estimación de la profundidad del permafrost continuo en esta zona de estudio. El presente trabajo se encuadra en proyecto internacional del Año Polar Internacional (API) y promovido por la Asociación Internacional del Permafrost (IPA) que lleva como título “Thermal State of Permafrost”(TSP).