Observation of a single protein by ultrafast X-ray diffraction.

The idea of using ultrashort X-ray pulses to obtain images of single proteins frozen in time has fascinated and inspired many. It was one of the arguments for building X-ray free-electron lasers. According to theory, the extremely intense pulses provide sufficient signal to dispense with using crystals as an amplifier, and the ultrashort pulse duration permits capturing the diffraction data before the sample inevitably explodes. This was first demonstrated on biological samples a decade ago on the giant mimivirus. Since then, a large collaboration has been pushing the limit of the smallest sample that can be imaged. The ability to capture snapshots on the timescale of atomic vibrations, while keeping the sample at room temperature, may allow probing the entire conformational phase space of macromolecules. Here we show the first observation of an X-ray diffraction pattern from a single protein, that of Escherichia coli GroEL which at 14 nm in diameter is the smallest biological sample ever imaged by X-rays, and demonstrate that the concept of diffraction before destruction extends to single proteins. From the pattern, it is possible to determine the approximate orientation of the protein. Our experiment demonstrates the feasibility of ultrafast imaging of single proteins, opening the way to single-molecule time-resolved studies on the femtosecond timescale.

The impact of the association between Val16Ala-SOD2 SNP and SOD2 immunohistochemistry expression in the prognosis of patients with esophageal cancer.

INTRODUCTION: Esophageal cancer is an extensive public health issue worldwide, warranting the search for biomarkers related to its risk and progression. Previous studies have indicated an association between Val16AlaSOD2 single nucleotide polymorphism in the gene encoding the enzyme superoxide dismutase 2 and esophageal cancer. However, further investigations are needed to clarify its role in disease risk and progression. OBJECTIVE: To investigate the role of Val16AlaSOD2-SNP in esophageal cancer progression and in the survival of patients METHODS: Tumor samples were utilized for Val16Ala-SNP genotyping, while SOD2 expression levels in tissue were assessed using immunohistochemistry. A SOD2 Val16Ala-SNP database was used to obtain information on the genotype of healthy individuals. Risk and overall survival analyzes were performed. RESULTS: The Val16Ala SNP was associated with an increased risk of esophageal cancer (RR 2.18, 95%CI 1.23-3.86), regardless of age and gender, but did not have a significant effect on patient survival. In contrast, weak SOD2 expression demonstrated a significantly associated with poor overall survival after treatment, independent of other clinicopathological variables (HR, 0.41; 95% CI, 0.22-0.79 P = 0.007). CONCLUSIONS: Val16Ala SNP was positively associated with esophageal cancer, and the expression of SOD2 was an independent prognostic marker.

Feasibility of renal perfusion quantification by Fourier decomposition MRI.

PURPOSE: To evaluate the feasibility of perfusion measurements in the human kidney by Fourier decomposition MRI (FD-MRI). METHODS: Renal perfusion measurements by FD-MRI and arterial spin labeling (ASL) were performed using a 1.5 T whole-body MR-scanner (Magnetom Avanto, Siemens Healthineers AG, Germany) in 15 healthy volunteers (mean age 33.0 ± 13.6 years). Five healthy volunteers were measured twice to evaluate the reproducibility. Besides, five patients with renal artery stenosis (RAS) (mean age 58.4 ± 16.2 years) were included in the study to evaluate potential clinical use of the FD-MRI for evaluating renal perfusion. For renal FD-MRI, coronal 2D-TrueFisp sequence (1 section; section thickness: 10 mm; FOV: 400 × 400 mm 2; TR/TE: 2.06/0.89 ms; 250 images; 0,36 s/image), for renal ASL, coronal FAIR-TrueFisp sequence (1 section; section thickness: 10 mm; FOV: 400 × 400 mm2; TR/TE 4.0/2.0 ms, TI 1200 ms, 30 averages; 8,32 s/average) were acquired without any triggering. Perfusion parameter maps of the kidneys were calculated for both methods. After manual segmentation, ROI-based analysis (whole kidney, cortex and medulla, respectively) was performed and the results were subsequently compared using the Student t-test. RESULTS: The acquisition times were 1.30 min and 4.16 min, for renal FD-MRI and ASL, respectively. No significant difference in global renal perfusion (RBF) between both methods was detected (mean RBF in the right kidney: 308.4 ± 31.5 mL/100 mL/min for FD-MRI; 315.2 ± 41.1 for ASL; in the left kidney: 315.6 ± 32.8 mL/100 mL/min for FD-MRI; 310.2 ± 39.1 mL/100 mL/min for ASL, respectively). The results indicated good reproducibility of both considered methods. However, cortico-medullar differentiation was not possible by FD-MRI, probably due to lower SNR compared to ASL. Significant difference in the side-separated RBF were measured by FD-MRI as well as by ASL (p < 0.05) in patients with RAS. CONCLUSIONS: FD-MRI is a novel, rapid approach for contrast-free perfusion quantification in the human kidney. Main advantage of this new method compared to ASL perfusion is the significant shorter acquisition time and lower dependency on patient's compliance. However, lower SNR of FD-MRI needs further improvement to make FD-MRI a competitive alternative to ASL.

Imaging of exercise-induced spinal remodeling in elite rowers.

OBJECTIVES: As in-vivo knowledge of training-induced remodeling of intervertebral discs (IVD) is scarce, this study assessed how lumbar IVDs change as a function of long-term training in elite athletes and age-matched controls using compositional Magnetic Resonance Imaging (MRI). DESIGN: Prospective case-control study. METHODS: Prospectively, lumbar spines of 17 elite rowers (ERs) of the German national rowing team (mean age: 23.9 ±â€¯3.3 years) were imaged on a clinical 3.0 T MRI scanner. ERs were imaged twice during the annual training cycle, i.e., at training intensive preseason preparations (t0) and 6 months later during post-competition recovery (t1). Controls (n = 22, mean age: 26.3 ±â€¯1.9 years) were imaged once at corresponding time points (t0: n = 11; t1: n = 11). Segment-wise, the glycosaminoglycan (GAG) content of lumbar IVDs (n = 195) was determined using glycosaminoglycan chemical exchange saturation transfer (gagCEST). Linear mixed models were set up to assess the influence of cohort and other variables on GAG content. RESULTS: During preseason, IVD GAG values of ERs were significantly higher than those of controls (ERs(t0): 2.58 ±â€¯0.27% (mean ±â€¯standard deviations); controls(t0): 1.43 ±â€¯0.36%; p ≤ 0.001), while during post-competition recovery, such differences were not present anymore (ERs(t1): 2.11 ±â€¯0.18%; controls(t1): 1.89 ±â€¯0.24%; p = 0.362). CONCLUSIONS: Professional elite-level rowing is transiently associated with significantly higher gagCEST values, which indicate increased lumbar IVD-GAG content and strong remodeling effects in response to training. Beyond professional rowing, core-strengthening full-body exercise may help to enhance the resilience of the lumbar spine as a potential therapeutic target in treating back pain.

Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke.

BACKGROUND AND PURPOSE: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. METHODS: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. RESULTS: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest (P=0.002) and movement-related beta desynchronization (P=0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. CONCLUSIONS: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.

Importance and vulnerability of the world's water towers.

Mountains are the water towers of the world, supplying a substantial part of both natural and anthropogenic water demands1,2. They are highly sensitive and prone to climate change3,4, yet their importance and vulnerability have not been quantified at the global scale. Here we present a global water tower index (WTI), which ranks all water towers in terms of their water-supplying role and the downstream dependence of ecosystems and society. For each water tower, we assess its vulnerability related to water stress, governance, hydropolitical tension and future climatic and socio-economic changes. We conclude that the most important (highest WTI) water towers are also among the most vulnerable, and that climatic and socio-economic changes will affect them profoundly. This could negatively impact 1.9 billion people living in (0.3 billion) or directly downstream of (1.6 billion) mountainous areas. Immediate action is required to safeguard the future of the world's most important and vulnerable water towers.

Differential DNA methylation in experienced meditators after an intensive day of mindfulness-based practice: Implications for immune-related pathways.

The human methylome is dynamically influenced by psychological stress. However, its responsiveness to stress management remains underexplored. Meditation practice has been shown to significantly reduce stress level, among other beneficial neurophysiological outcomes. Here, we evaluated the impact of a day of intensive meditation practice (t2-t1 = 8 h) on the methylome of peripheral blood mononuclear cells in experienced meditators (n = 17). In parallel, we assessed the influence of a day of leisure activities in the same environment on the methylome of matched control subjects with no meditation experience (n = 17). DNA methylation profiles were analyzed using the Illumina 450 K beadchip array. We fitted for each methylation site a linear model for multi-level experiments which adjusts the variation between t1 and t2 for baseline differences. No significant baseline differences in methylation profiles was detected between groups. In the meditation group, we identified 61 differentially methylated sites (DMS) after the intervention. These DMS were enriched in genes mostly associated with immune cell metabolism and ageing and in binding sites for several transcription factors involved in immune response and inflammation, among other functions. In the control group, no significant change in methylation level was observed after the day of leisure activities. These results suggest that a short meditation intervention in trained subjects may rapidly influence the epigenome at sites of potential relevance for immune function and provide a better understanding of the dynamics of the human methylome over short time windows.

Prediction-based neural mechanisms for shielding the self from existential threat.

The human mind has an automatic tendency to avoid awareness of its mortality. How this protective mechanism is implemented at the neuronal level is unknown. Here we test the hypothesis that prediction-based mechanisms mediate death-denial by shielding the self from existential threat. We provide evidence that self-specific predictive processes are downregulated during the perception of death-related linguistic stimuli and that this mechanism can predict fear-of-death. Using a magnetoencephalography visual mismatch paradigm, we show that the brain's automatic prediction response to deviancy is eliminated when death words and self-face representations are coupled, but remains present when coupled to other-face or to negative words. We further demonstrate a functional link between how death impacts self-image vs. Other-image, and show that it predicts fear-of-death. Finally, we confirm this effect in a behavioral active inference experiment showing that death-related words bias perceptual judgment on facial self and other morphed video clips. Together these results lay out, for the first time, a plausible neural-based mechanism of death-denial.

Auditory perceptual learning is not affected by anticipatory anxiety in the healthy population except for highly anxious individuals: EEG evidence.

OBJECTIVE: A recent neurocomputational model proposed that anxious hypervigilance impedes perceptual learning. This view is supported by the observed modulation of the mismatch negativity (MMN), a biomarker of implicit perceptual learning processes, in anxiety disorders. However, other studies found that anxious states sensitize brain responses with no impact on perceptual learning. The present research aimed to elucidate the impact of anticipatory anxiety on early stimulus processing in the healthy population. METHODS: We used electroencephalography to investigate the impact of unpredictable threat on the amplitude of the MMN and other components of the auditory evoked response in healthy participants during a passive auditory oddball task. RESULTS: We found a general sensitization of early components of the auditory evoked response and changes in subjective and autonomic measures of anxiety during threat periods. The MMN amplitude did not differ during threat, compared to safe periods. However, this difference was modulated by the level of state or trait anxiety. CONCLUSION: We propose that anxiety sensitizes early brain responses to unspecific environmental stimuli but affects implicit perceptual learning processes only when an individual is located at the higher end of the anxiety spectrum. SIGNIFICANCE: This view might distinguish between an adaptive role of anxiety on processing efficiency and its detrimental impact on implicit perceptual learning observed in psychiatric conditions.

'Birth defects' of photosystem II make it highly susceptible to photodamage during chloroplast biogenesis.

High solar flux is known to diminish photosynthetic growth rates, reducing biomass productivity and lowering disease tolerance. Photosystem II (PSII) of plants is susceptible to photodamage (also known as photoinactivation) in strong light, resulting in severe loss of water oxidation capacity and destruction of the water-oxidizing complex (WOC). The repair of damaged PSIIs comes at a high energy cost and requires de novo biosynthesis of damaged PSII subunits, reassembly of the WOC inorganic cofactors and membrane remodeling. Employing membrane-inlet mass spectrometry and O2 -polarography under flashing light conditions, we demonstrate that newly synthesized PSII complexes are far more susceptible to photodamage than are mature PSII complexes. We examined these 'PSII birth defects' in barley seedlings and plastids (etiochloroplasts and chloroplasts) isolated at various times during de-etiolation as chloroplast development begins and matures in synchronization with thylakoid membrane biogenesis and grana membrane formation. We show that the degree of PSII photodamage decreases simultaneously with biogenesis of the PSII turnover efficiency measured by O2 -polarography, and with grana membrane stacking, as determined by electron microscopy. Our data from fluorescence, QB -inhibitor binding, and thermoluminescence studies indicate that the decline of the high-light susceptibility of PSII to photodamage is coincident with appearance of electron transfer capability QA - → QB during de-etiolation. This rate depends in turn on the downstream clearing of electrons upon buildup of the complete linear electron transfer chain and the formation of stacked grana membranes capable of longer-range energy transfer.

Association of Extrapyramidal Tracts' Integrity With Performance in Fine Motor Skills After Stroke.

Background and Purpose- Tractography by diffusion tensor imaging has extended our knowledge on the contribution of damage to different pathways to residual motor function after stroke. Integrity of the corticospinal tract (CST), for example, has been identified to characterize and predict its course. Yet there is only scarce data that allow a judgment on the impact of extrapyramidal pathways between the basal ganglia on motor function poststroke. We aimed at studying their association with performance in fine motor skills after stroke. Methods- We performed probabilistic tractography and reconstructed nigro-pallidal tracts connecting substantia nigra and globus pallidus, as well as the CST in 26 healthy subjects. Resulting tracts were registered to the individual images of 20 patients 3 months after stroke, and their microstructural integrity was measured by fractional anisotropy. Clinical examination of the patients' gross (grip force) and fine (nine-hole peg test) motor skills was performed 1 year after stroke. For assessment of factors influencing nine-hole peg test, we used a multivariate model. Results- Nigro-pallidal tracts were traceable in all participants, had no overlap to the CST and passed the nucleus subthalamicus. In stroke patients, nigro-pallidal tracts ipsilateral to the stroke lesion showed a significantly reduced fractional anisotropy (ratio, 0.96±0.02; P=0.021). One year after stroke, nine-hole peg test values were significantly slower for the affected hand, while grip force was comparable between both hands. Reduced integrity of the nigro-pallidal tracts was associated with worse performance in the nine-hole peg test ( P=0.040), as was reduced integrity of the CST ( P<0.001) and younger age ( P<0.001). Conclusions- Nigro-pallidal tracts with containing connections of the nucleus subthalamicus represent a relevant part of the extrapyramidal system and specifically contribute to residual fine motor skills after stroke beyond the well-known contribution of the CST. They may deliver supportive information for prediction of motor recovery after stroke.

Differential effects of non-dual and focused attention meditations on the formation of automatic perceptual habits in expert practitioners.

Non-dual meditation aims to undo maladaptive cognitive and affective patterns by recognizing their constructed and transient nature. We previously found high-amplitude spontaneous gamma (25-40 Hz) oscillatory activity during such practice. Nonetheless, it is unclear how this meditation state differs from other practices, in terms of perceptual information processing. Here, we hypothesized that non-dual meditation can downregulate the automatic formation of perceptual habits. To investigate this hypothesis, we recorded EEG from expert Buddhist meditation practitioners and matched novices to measure two components of the auditory evoked response: the Mismatch Negativity (MMN) and the Late Frontal Negativity (LFN), a potential observed at a latency sensitive to attentional engagement to the auditory environment, during the practices of Open Presence (OP) and Focused Attention (FA), as well as during a control state, in the context of a passive oddball paradigm. We found an increase in gamma oscillatory power during both meditation states in expert practitioners and an interaction between states and groups in the amplitude of the MMN. A further investigation identified the specific interplay between the MMN and the LFN as a possible marker to differentiate the two meditation states as a function of expertise. In experts, the MMN increased during FA, compared to OP, while the opposite pattern was observed at the LFN latency. We propose that the state of OP in experts is characterized by increased sensory monitoring and reduced perceptual inferences compared to FA. This study represents a first attempt to describe the impact of non-dual meditation states on the regulation of automatic brain predictive processes.

Influence of arterial input function (AIF) on quantitative prostate dynamic contrast-enhanced (DCE) MRI and zonal prostate anatomy.

PURPOSE: Reproducibility of quantitative perfusion analysis of DCE requires a standardized AIF acquisition. However, there are many different approaches for AIF assessment so that the absolute values of perfusion parameters may vary depending on the used method. This study analyzes the influence of the method of AIF determination on quantitative DCE-MRI. METHODS: In this retrospective, single-center, cohort study three different methods of AIF determination in 50 consecutive patients with multiparametric MRI of the prostate were conducted. As a reference, AIF was selected manually by defining a region of interest in an artery manually (AIFm). The second method (AIFa), based on an automated algorithm and the third, population-derived AIFp where then compared. Primary endpoint were differences in the performance of the perfusion parameters Ktrans, ve and kep regarding the AIF acquisition methods, secondary endpoints consisted of the evaluation of differences in the peripheral and transition zone of the prostate (PZ, TZ). RESULTS: In all three methods, Ktrans, ve, and kep were significantly higher in PZ than in TZ with Ktrans showing least overlapping. There were no significant differences for Ktrans determined with AIFm and AIFa (0.3 ±â€¯0.2 min-1 for PZ for both and 0.5 ±â€¯0.3 min-1 for TZ in AIFm and 0.4 ±â€¯0.3 min-1 in AIFa), while there were great differences between AIFa and AIFp and AIFm and AIFp (0.1 ±â€¯0.03 min-1 for TZ and PZ in AIFp). Spearman test demonstrated good correlation of values for Ktrans and kep in all 3 methods (ρ ≥ 0.76). AIFa showed a success rate of 98% in finding the artery. CONCLUSION: AIFa is a recommendable user-independent automatical method to determine quantitative perfusion parameters allowing an objective measurement and saving interactive time for the radiologist. AIFp may be applied as second alternative method.

Radiostereometric migration measurement of an uncemented Cerafit® femoral stem: 26 patients followed for 10 years.

Radiostereometric analysis (RSA) is the gold standard for evaluating micromotions of orthopaedic implants. The method is applied for identifying novel design weaknesses in endoprostheses. Current research frequently assesses relatively short time periods. Short-term RSA studies have been widely used for predicting the long-term stability of many hip prosthetic designs, but only a few studies have focused on uncemented hip implants, especially for extended periods. The purpose of this study was to analyse the migration pattern of the Cerafit® femoral stem within 10 years and to verify the predictive value of short-term RSA after 2 years for this uncemented femoral hip stem. Twenty-six patients were followed for 10 years. Ten years after implantation, a mean subsidence of 0.22 mm±0.56 mm, a mean internal rotation of 0.59°±1.67° and a mean maximum total point motion (MTPM) of 1.28 mm±0.54 mm were detected. The main migration took place in the first 6 weeks after surgery (subsidence of 0.36 mm±0.73 mm; internal rotation of 0.62°±1.49°, MTPM of 1.05 mm±0.68 mm). All the migration values measured were small. No late-onset migration was observed. This study suggests that the Cerafit® implants are stable after 10 years. Thus, RSA could be the best tool to assess long-term implant behaviour.

[Pain in patients with paraplegia]. / Schmerzen bei Patienten mit Querschnittlähmung.

Chronic pain is one of the most reported health problems in patients suffering from spinal cord injuries and is described by the patients as one of the most burdensome sequelae of paraplegia. Various types of pain, such as nociceptive, neuropathic and other types of pain can occur. In addition, multiple pathophysiological mechanisms based on the biopsychosocial pain model play a role in the origins of the pain. These aspects necessitate a multimodal pain management approach in this patient group. This article presents an overview of the occurrence, importance and pathophysiology of chronic pain following spinal cord injury as well as diagnostic and therapeutic approaches.

Impact of a global temperature rise of 1.5 degrees Celsius on Asia's glaciers.

Glaciers in the high mountains of Asia (HMA) make a substantial contribution to the water supply of millions of people, and they are retreating and losing mass as a result of anthropogenic climate change at similar rates to those seen elsewhere. In the Paris Agreement of 2015, 195 nations agreed on the aspiration to limit the level of global temperature rise to 1.5 degrees Celsius ( °C) above pre-industrial levels. However, it is not known what an increase of 1.5 °C would mean for the glaciers in HMA. Here we show that a global temperature rise of 1.5 °C will lead to a warming of 2.1 ± 0.1 °C in HMA, and that 64 ± 7 per cent of the present-day ice mass stored in the HMA glaciers will remain by the end of the century. The 1.5 °C goal is extremely ambitious and is projected by only a small number of climate models of the conservative IPCC's Representative Concentration Pathway (RCP)2.6 ensemble. Projections for RCP4.5, RCP6.0 and RCP8.5 reveal that much of the glacier ice is likely to disappear, with projected mass losses of 49 ± 7 per cent, 51 ± 6 per cent and 64 ± 5 per cent, respectively, by the end of the century; these projections have potentially serious consequences for regional water management and mountain communities.

Supercomplexes of plant photosystem I with cytochrome b6f, light-harvesting complex II and NDH.

Photosystem I (PSI) is a pigment-protein complex required for the light-dependent reactions of photosynthesis and participates in light-harvesting and redox-driven chloroplast metabolism. Assembly of PSI into supercomplexes with light harvesting complex (LHC) II, cytochrome b6f (Cytb6f) or NAD(P)H dehydrogenase complex (NDH) has been proposed as a means for regulating photosynthesis. However, structural details about the binding positions in plant PSI are lacking. We analyzed large data sets of electron microscopy single particle projections of supercomplexes obtained from the stroma membrane of Arabidopsis thaliana. By single particle analysis, we established the binding position of Cytb6f at the antenna side of PSI. The rectangular-shaped Cytb6f dimer binds at the side where Lhca1 is located. The complex binds with its short side rather than its long side to PSI, which may explain why these supercomplexes are difficult to purify and easily disrupted. Refined analysis of the interaction between PSI and the NDH complex indicates that in total up to 6 copies of PSI can arrange with one NDH complex. Most PSI-NDH supercomplexes appeared to have 1-3 PSI copies associated. Finally, the PSI-LHCII supercomplex was found to bind an additional LHCII trimer at two positions on the LHCI side in Arabidopsis. The organization of PSI, either in a complex with NDH or with Cytb6f, may improve regulation of electron transport by the control of binding partners and distances in small domains.

Climate Change Impacts on the Upper Indus Hydrology: Sources, Shifts and Extremes.

The Indus basin heavily depends on its upstream mountainous part for the downstream supply of water while downstream demands are high. Since downstream demands will likely continue to increase, accurate hydrological projections for the future supply are important. We use an ensemble of statistically downscaled CMIP5 General Circulation Model outputs for RCP4.5 and RCP8.5 to force a cryospheric-hydrological model and generate transient hydrological projections for the entire 21st century for the upper Indus basin. Three methodological advances are introduced: (i) A new precipitation dataset that corrects for the underestimation of high-altitude precipitation is used. (ii) The model is calibrated using data on river runoff, snow cover and geodetic glacier mass balance. (iii) An advanced statistical downscaling technique is used that accounts for changes in precipitation extremes. The analysis of the results focuses on changes in sources of runoff, seasonality and hydrological extremes. We conclude that the future of the upper Indus basin's water availability is highly uncertain in the long run, mainly due to the large spread in the future precipitation projections. Despite large uncertainties in the future climate and long-term water availability, basin-wide patterns and trends of seasonal shifts in water availability are consistent across climate change scenarios. Most prominent is the attenuation of the annual hydrograph and shift from summer peak flow towards the other seasons for most ensemble members. In addition there are distinct spatial patterns in the response that relate to monsoon influence and the importance of meltwater. Analysis of future hydrological extremes reveals that increases in intensity and frequency of extreme discharges are very likely for most of the upper Indus basin and most ensemble members.

Facet tropism and facet joint orientation: risk factors for the development of early biochemical alterations of lumbar intervertebral discs.

OBJECTIVE: To assess the glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVD) in healthy volunteers with facet tropism (FT) and sagittal facet joint (FJ) orientation using glycosaminoglycan chemical exchange saturation transfer imaging (gagCEST). METHOD: Seventy-five lumbar IVDs of twenty-five young, healthy volunteers without any history of lumbar spine pathologies (13 female; 12 male; mean age: 28.0 ± 4.4 years; range: 21-35 years) were examined with a 3T MRI scanner. Orientation of FT and FJ were assessed for L3/4, L4/5 and L5/S1 using standard T2 weighted images. Biochemical gagCEST imaging was used to determine the GAG content of each nucleus pulposus (NP) and annulus fibrosus (AF). RESULTS: Significantly higher gagCEST values of NP were found in volunteers without FT and normal FJ orientation compared to volunteers with FT and sagittal FJ orientation >45° (P < 0.0001). GagCEST values were significantly higher in volunteers without FT compared to volunteers with moderate or severe FT (moderate FT: P < 0.0001; severe FT: P = 0.0033). Volunteers with normal FJ orientation showed significantly higher gagCEST values compared to those with sagittal FJ orientation >45° (P < 0.001). We found a significant, negative correlation between gagCEST values and higher angels in sagittal FJ orientation (rho = -0.459; P < 0.0001). CONCLUSION: GagCEST analysis indicated lower GAG values of NP in young volunteers with FT and sagittal orientated FJ, indicating that FT and sagittal orientation of the FJ represent risk factors for the development of early biochemical alterations of lumbar IVDs.

The influence of maternal nutrition on expression of genes responsible for adipogenesis and myogenesis in the bovine fetus.

The objective of this study was to determine whether altered maternal energy supply during mid-gestation results in differences in muscle histology or genes regulating fetal adipose and muscle development. In total, 22 Angus cross-bred heifers (BW=527.73±8.3 kg) were assigned randomly to the three dietary treatments providing 146% (HIGH; n=7), 87% (INT; n=7) or 72% (LOW; n=8) of the energy requirements for heifers from day 85 to day 180 of gestation. Fetuses were removed via cesarean section at day 180 of gestation and longissimus muscle (LM) and subcutaneous fat were collected and prepared for analysis of gene expression. Samples from the LM and semitendinosus (ST) were evaluated for muscle fiber diameter, area and number. The right hind limb was dissected and analyzed to determine compositional analysis. Fetal growth and muscle histology characteristics of the LM and ST were similar among treatments. Preadipocyte factor-1 expression was up-regulated in fetal LM (P<0.05) of HIGH fetuses as compared with INT, whereas LOW fetuses showed increased CCAAT/enhancer-binding protein-ß (C/EBP-ß) expression in LM as compared with INT (P<0.05). Peroxisome proliferator-activated receptor γand C/EBP-α did not differ as a result of dietary treatment in LM or subcutaneous fat samples. There was a tendency for increased expression of fatty acid synthase in LM of LOW fetuses as compared with INT (P<0.10). Myogenin was more highly expressed (P<0.05) in LM of the LOW fetuses, whereas µ-calpain expression was increased in the HIGH treatment compared with INT. A tendency for increased expression of IGF-II was observed for both LOW and HIGH fetuses compared with INT (P<0.10). Expression of stearoyl-CoA desaturase, myoblast determination protein 1, myogenic factor 5, myogenic regulatory factor-4, m-calpain, calpastatin, IGF-I and myostatin was similar between treatments. Collectively, these results suggest that fetal growth characteristics are not affected by the level of maternal nutritional manipulation imposed in this study during mid-gestation. However, differences in expression of fetal genes regulating adipose and muscle tissue growth and development could lead to differences in postnatal composition and warrants further investigation.