Generalized Lévy walks and the role of chemokines in migration of effector CD8+ T cells.

Chemokines have a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. Here we track T cells using multi-photon microscopy to demonstrate that the chemokine CXCL10 enhances the ability of CD8+ T cells to control the pathogen Toxoplasma gondii in the brains of chronically infected mice. This chemokine boosts T-cell function in two different ways: it maintains the effector T-cell population in the brain and speeds up the average migration speed without changing the nature of the walk statistics. Notably, these statistics are not Brownian; rather, CD8+ T-cell motility in the brain is well described by a generalized Lévy walk. According to our model, this unexpected feature enables T cells to find rare targets with more than an order of magnitude more efficiency than Brownian random walkers. Thus, CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets

The new onset of dysphagia four years after anterior cervical discectomy and fusion: Case report and literature review.

Background: Dysphagia is a common complication immediately following anterior cervical spine surgery. However, its onset more than 1-year postoperatively is rare. Case Description: A 45-year-old male initially underwent a C3-4 and C5-6 anterior cervical discectomy and fusion (ACDF). At age 49, 4 years later, he presented with worsening dysphagia accompanied by neck and right upper extremity pain. Radiographs demonstrated an extruded left C3 screw, which had migrated into the prevertebral soft tissues at the C4-C5 level; there was also loosening of the right C3 screw. The subsequent barium swallow study revealed that the screw was embedded in the pharyngeal wall. The patient required a two-stage operation; first, to remove the anterior instrumentation, and second, to perform a posterior instrumented C2-T2 fusion. Conclusion: A barium swallow study and other dynamic imaging are a valuable component of the diagnostic workup and therapeutic intervention to evaluate the delayed onset dysphagia following an ACDF

Dung beetles as hydrological engineers: effects of tunnelling on soil infiltration

1. Soil infiltration capacity determines the partitioning of precipitation into infiltration and overland flow and is therefore an important soil hydrological characteristic. Water infiltration through soil is facilitated by macropores created by roots and soil macrofauna. In clay-rich soils, such as those of the tropical forests of Sabah, Malaysian Borneo, most infiltration occurs via these preferential flow pathways. 2. We evaluated the effects of dung beetle tunnelling on infiltration and macropore creation (depth and width of the flow pathways) in tropical forest soils in Sabah. Using mesocosms, we applied three treatments (i) soil-only, (ii) dung-only, (iii) dung + dung beetles, and measured saturated hydraulic conductivity (i.e., the steady-state infiltration rate) after 0, 5 and 10 days, and assessed depth and width of infiltration pathways by applying a blue dye tracer. 3. The steady-state infiltration rate increased in the presence of dung beetles, though differences among treatments were only statistically significant after 10 days. After 5 days of dung beetle presence, infiltrated water had reached a greater depth than the control mesocosms without beetles. However, there were no differences in the width of infiltration pathways among treatments. 4. These results reveal the important, but under studied roles of dung beetles on soil hydrological functioning, that may have consequences for nutrient cycling and plant productivity. Further, our findings indicate that the novel application of an established hydrological method—blue dye tracer—can provide interesting and reliable results for macrofauna–soil interaction studies.ISSN:0307-6946ISSN:1365-231

Does heterogeneity in regenerating secondary forests affect mean throughfall?

As secondary tropical forests grow, their canopy structure and density change. This affects the canopy storage and aerodynamic roughness, and thus the amount of water that is lost to interception. Because interception is a considerable part of total evapotranspiration, it is important to assess how interception changes as secondary forests mature, and how this is affected by forest structure. However, the effects of tropical forest regeneration, and in particular changes in forest structure, on mean throughfall are so far poorly studied. This hampers the estimation of the interception loss, and thus the water balance, for regenerating forests. Therefore, we monitored throughfall for twelve regenerating, logged-over forest plots in Sabah, Malaysian Borneo over a 7-month period to determine the effects of forest regeneration on mean throughfall and tested if inclusion of measures of forest heterogeneity improves the prediction of mean throughfall compared to estimates based on tree height or density alone. Mean throughfall varied between 74% and 89% (average: 84%) of precipitation and was lowest in regenerating forest plots with a longer time since logging. There was a significant negative relationship between mean throughfall and tree density or basal area, as well as variables reflecting forest heterogeneity (i.e., the Shannon Diversity Index and the coefficient of variation of the diameter at breast height). Nevertheless, the inclusion of these indicators of heterogeneity did not improve model performance substantially; the best model was a linear relation with tree density alone. These results suggest that in the context of logged and regenerating forests in Sabah, mean throughfall depends mainly on tree density and is not substantially affected by species diversity or structural heterogeneity. To see if mean throughfall could be estimated over larger spatial scales based on LiDAR data, we also tested the relation between mean throughfall and LiDAR-derived Top of Canopy (TCH) but this relation was not significant for our study plots. A more in-depth analysis of LiDAR-products, such as point clouds, may be needed to estimate mean throughfall over large areas in tropical rainforests

Dung beetles as hydrological engineers: effects of tunnelling on soil infiltration

1. Soil infiltration capacity determines the partitioning of precipitationinto infiltration and overland flow and is therefore an important soil hydrologicalcharacteristic. Water infiltration through soil is facilitated by macropores created byroots and soil macrofauna. In clay-rich soils, such as those of the tropical forests ofSabah, Malaysian Borneo, most infiltration occurs via these preferential flow pathways. 2. We evaluated the effects of dung beetle tunnelling on infiltration and macroporecreation (depth and width of the flow pathways) in tropical forest soils in Sabah. Usingmesocosms, we applied three treatments (i) soil-only, (ii) dung-only, (iii) dung+dungbeetles, and measured saturated hydraulic conductivity (i.e., the steady-state infiltrationrate) after 0, 5 and 10 days, and assessed depth and width of infiltration pathways byapplying a blue dye tracer. 3. The steady-state infiltration rate increased in the presence of dung beetles, thoughdifferences among treatments were only statistically significant after 10 days. After5 days of dung beetle presence, infiltrated water had reached a greater depth than thecontrol mesocosms without beetles. However, there were no differences in the width ofinfiltration pathways among treatments. 4. These results reveal the important, but under studied roles of dung beetles on soilhydrological functioning, that may have consequences for nutrient cycling and plantproductivity. Further, our findings indicate that the novel application of an establishedhydrological method–blue dye tracer–can provide interesting and reliable results formacrofauna–soil interaction studies

Does multimodal analgesia with acetaminophen, nonsteroidal antiinflammatory drugs, or selective cyclooxygenase-2 inhibitors and patientcontrolled analgesia morphine offer advantages over morphine alone? Meta-analyses of randomized trials

The authors analyzed data from 52 randomized placebocontrolled trials (4,893 adults) testing acetaminophen, nonsteroidal antiinflammatory drugs, or selective cyclooxygenase-2 inhibitors given in conjunction with morphine after surgery. The median of the average 24-h morphine consumption in controls was 49 mg (range, 15-117 mg); it was significantly decreased with all regimens by 15-55%. There was evidence of a reduction in pain intensity at 24 h (1 cm on the 0-to 10-cm visual analog scale) only with nonsteroidal antiinflammatory drugs. Nonsteroidal antiinflammatory drugs also significantly reduced the incidence of nausea/vomiting from 28.8% to 22.0% (number needed to treat, 15) and of sedation from 15.4% to 12.7% (number needed to treat, 37) but increased the risk of severe bleeding from 0% to 1.7% (number needed to harm, 59). Selective cyclooxygenase-2 inhibitors increased the risk of renal failure in cardiac patients from 0% to 1.4% (number needed to harm, 73). A decrease in morphine consumption is not a good indicator of the usefulness of a supplemental analgesic. There is evidence that the combination of nonsteroidal antiinflammatory drugs with patient-controlled analgesia morphine offers some advantages over morphine alone

Offline and online LSTM networks for respiratory motion prediction in MR-guided radiotherapy

Objective. Gated beam delivery is the current clinical practice for respiratory motion compensation in MR-guided radiotherapy, and further research is ongoing to implement tracking. To manage intra-fractional motion using multileaf collimator tracking the total system latency needs to be accounted for in real-time. In this study, long short-term memory (LSTM) networks were optimized for the prediction of superior–inferior tumor centroid positions extracted from clinically acquired 2D cine MRIs. Approach. We used 88 patients treated at the University Hospital of the LMU Munich for training and validation (70 patients, 13.1 h), and for testing (18 patients, 3.0 h). Three patients treated at Fondazione Policlinico Universitario Agostino Gemelli were used as a second testing set (1.5 h). The performance of the LSTMs in terms of root mean square error (RMSE) was compared to baseline linear regression (LR) models for forecasted time spans of 250 ms, 500 ms and 750 ms. Both the LSTM and the LR were trained with offline (offline LSTM and offline LR) and online schemes (offline+online LSTM and online LR), the latter to allow for continuous adaptation to recent respiratory patterns. Main results. We found the offline+online LSTM to perform best for all investigated forecasts. Specifically, when predicting 500 ms ahead it achieved a mean RMSE of 1.20 mm and 1.00 mm, while the best performing LR model achieved a mean RMSE of 1.42 mm and 1.22 mm for the LMU and Gemelli testing set, respectively. Significance. This indicates that LSTM networks have potential as respiratory motion predictors and that continuous online re-optimization can enhance their performance

Biodiversity consequences of long-term active forest restoration in selectively logged tropical rainforests

Forest restoration figures prominently on climate action plans, both in the public and private sector. Restoration has the potential to enhance forest recovery and carbon storage, yet could cause unanticipated alterations of forest biodiversity and functioning. In particular little is known about the long-lasting effects of active forest restoration. We therefore evaluated the effects of such management on adult trees and seedlings of actively restored forest to comparable areas where forest regenerated naturally. We investigated a forest site in Sabah, Malaysian Borneo that is recovering from selective logging between 1981 and 1991. Some of the area has been left to naturally regenerate, and some areas have been actively restored for production purposes between 1994 and 2004 through climber cutting and enrichment-planting of exclusively indigenous tree species. We hypothesized that active forest restoration affects forest diversity and composition negatively (i.e., reduction in diversity and presence of pioneer species), and that the silvicultural interventions had long-lasting effects (i.e., higher density of species that were planted, fewer climbers). Surprisingly, our findings suggest that active forest restoration promoted the recovery of adult tree species diversity, expressed as Shannon Diversity Index, and in particular promoted rare species. In actively restored plots, the number of adult individuals of tree species that were planted was enhanced, and the density of liana seedlings was reduced, demonstrating that these silvicultural interventions were effective and had long-lasting effects on the forest structure. Nevertheless, we could not detect differences in the number of seedlings of species that were planted nor in the density of adult lianas between actively restored and naturally regenerating forest sites. We also did not find differences in the species diversity of seedlings, but we observed a compositional shift in the species community for seedlings that were younger than one year. Furthermore, we did not detect a difference between actively restored and naturally regenerating forest plots in the abundance of the present tree guilds (i.e., pioneer or late-succession species) for neither adult trees nor seedlings, as all of our forest plots were dominated by late-succession species. Our results show that active forest restoration can promote species diversity and highlight that active forest restoration focusing on biomass production does not need to adversely affect biodiversity. This work emphasizes the potential of active forest restoration on biodiversity and potentially other key ecosystem functions which are needed to be restored in order to mitigate climate change and the current ecological crisis

Analysis of Behavior and Trafficking of Dendritic Cells within the Brain during Toxoplasmic Encephalitis

Under normal conditions the immune system has limited access to the brain; however, during toxoplasmic encephalitis (TE), large numbers of T cells and APCs accumulate within this site. A combination of real time imaging, transgenic reporter mice, and recombinant parasites allowed a comprehensive analysis of CD11c+ cells during TE. These studies reveal that the CNS CD11c+ cells consist of a mixture of microglia and dendritic cells (DCs) with distinct behavior associated with their ability to interact with parasites or effector T cells. The CNS DCs upregulated several chemokine receptors during TE, but none of these individual receptors tested was required for migration of DCs into the brain. However, this process was pertussis toxin sensitive and dependent on the integrin LFA-1, suggesting that the synergistic effect of signaling through multiple chemokine receptors, possibly leading to changes in the affinity of LFA-1, is involved in the recruitment/retention of DCs to the CNS and thus provides new insights into how the immune system accesses this unique site

The BLAST Survey of the Vela Molecular Cloud: Physical Properties of the Dense Cores in Vela-D

The Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) carried out a 250, 350 and 500 micron survey of the galactic plane encompassing the Vela Molecular Ridge, with the primary goal of identifying the coldest dense cores possibly associated with the earliest stages of star formation. Here we present the results from observations of the Vela-D region, covering about 4 square degrees, in which we find 141 BLAST cores. We exploit existing data taken with the Spitzer MIPS, IRAC and SEST-SIMBA instruments to constrain their (single-temperature) spectral energy distributions, assuming a dust emissivity index beta = 2.0. This combination of data allows us to determine the temperature, luminosity and mass of each BLAST core, and also enables us to separate starless from proto-stellar sources. We also analyze the effects that the uncertainties on the derived physical parameters of the individual sources have on the overall physical properties of starless and proto-stellar cores, and we find that there appear to be a smooth transition from the pre- to the proto-stellar phase. In particular, for proto-stellar cores we find a correlation between the MIPS24 flux, associated with the central protostar, and the temperature of the dust envelope. We also find that the core mass function of the Vela-D cores has a slope consistent with other similar (sub)millimeter surveys.Comment: Accepted for publication in the Astrophysical Journal. Data and maps are available at http://blastexperiment.info