A positive relationship between the abundance of ammonia oxidizing archaea and natural abundance δ15N of ecosystems

We present a significant relationship between the natural abundance isotopic composition of ecosystem pools and the abundance of a microbial gene. Natural abundance 15N of soils and soil DNA were analysed and compared with archaeal ammonia oxidizer abundance along an elevation gradient in northern Arizona and along a substrate age gradient in Hawai'i. There was a significant positive correlation between the abundance of archaeal amoA genes and natural abundance δ15N of total soil or DNA suggesting that ammonia oxidizing archaea play an important role in ecosystem N release. © 2013 Elsevier Ltd

Seeing Tree Structure from Vibration

Humans recognize object structure from both their appearance and motion; often, motion helps to resolve ambiguities in object structure that arise when we observe object appearance only. There are particular scenarios, however, where neither appearance nor spatial-temporal motion signals are informative: occluding twigs may look connected and have almost identical movements, though they belong to different, possibly disconnected branches. We propose to tackle this problem through spectrum analysis of motion signals, because vibrations of disconnected branches, though visually similar, often have distinctive natural frequencies. We propose a novel formulation of tree structure based on a physics-based link model, and validate its effectiveness by theoretical analysis, numerical simulation, and empirical experiments. With this formulation, we use nonparametric Bayesian inference to reconstruct tree structure from both spectral vibration signals and appearance cues. Our model performs well in recognizing hierarchical tree structure from real-world videos of trees and vessels.Comment: ECCV 2018. The first two authors contributed equally to this work. Project page: http://tree.csail.mit.edu

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

Time trends of chest pain symptoms and health related quality of life in coronary artery disease

BACKGROUND: There is at present a lack of knowledge of time trends in health related quality of life (HRQL) in common patients with coronary artery disease (CAD) treated in ordinary care. The objective of this study is to assess and compare time trends of health related quality of life (HRQL) and chest pain in patients with coronary artery disease. METHODS: 253 consecutive CAD patients in Stockholm County, Sweden – 197 males/56 females; 60 ± 8 years – were followed during two years. Perceived chest pain symptoms and three global assessments of HRQL were assessed at baseline, after one and after two years. EuroQol-5 dimension (EQ-5D) with a predefined focus on function and symptoms; the broader tapping global estimates of HRQL; EuroQol VAS (EQ-VAS) and Cardiac Health Profile (CHP) were used. Chest pain was ranked according to Canadian Cardiovascular Society (CCS). Change in HRQL was analysed by a repeated measurements ANOVA and chest pain symptoms were analysed by Friedman non-parametric ANOVA. RESULTS: Perceived chest pain decreased during the two years (p < 0.00022); CCS 0: 41–51%; CCS 1: 19–15%; CCS 2: 31–27%; CCS 3: 5–4% and CCS 4: 4–2%. By contrast, HRQL did not change: EQ-5D: 0.76 (CI 0.73–0.79) -0.78 (CI 0.75–0.81), EQ-VAS: 0.68 (CI 0.66–0.71)-0.68 (CI 0.65–0.71) and CHP: 0.66 (CI 0.64–0.69) -0.66 (CI 0.64–0.69). CONCLUSION: HRQL did not increase despite a reduction in the severity of chest pain during two years. This implies that the major part of HRQL in these consecutive ordinary patients with CAD is unresponsive to change in chest pain symptoms

Decreased D2-40 and increased p16INK4A immunoreactivities correlate with higher grade of cervical intraepithelial neoplasia

<p>Abstract</p> <p>Background</p> <p>D2-40 has been shown a selective marker for lymphatic endothelium, but also shown in the benign cervical basal cells. However, the application of D2-40 immunoreactivity in the cervical basal cells for identifying the grade of cervical intraepithelial neoplasia (CIN) has not been evaluated.</p> <p>Methods</p> <p>In this study, the immunoreactive patterns of D2-40, compared with p16^INK4A, which is currently considered as the useful marker for cervical cancers and their precancerous diseases, were examined in total 125 cervical specimens including 32 of CIN1, 37 of CIN2, 35 of CIN3, and 21 of normal cervical tissue. D2-40 and p16^INK4Aimmunoreactivities were scored semiquantitatively according to the intensity and/or extent of the staining.</p> <p>Results</p> <p>Diffuse D2-40 expression with moderate-to-strong intensity was seen in all the normal cervical epithelia (21/21, 100%) and similar pattern of D2-40 immunoreactivity with weak-to-strong intensity was observed in CIN1 (31/32, 97.2%). However, negative and/or focal D2-40 expression was found in CIN2 (negative: 20/37, 54.1%; focal: 16/37, 43.2%) and CIN3 (negative: 22/35, 62.8%; focal: 12/35, 34.3%). On the other hand, diffuse immunostaining for p16^INK4Awas shown in 37.5% of CIN1, 64.9% of CIN2, and 80.0% of CIN3. However, the immunoreactive pattern of D2-40 was not associated with the p16^INK4Aimmunoreactivity.</p> <p>Conclusions</p> <p>Immunohistochemical analysis of D2-40 combined with p16^INK4Amay have a significant implication in clinical practice for better identifying the grade of cervical intraepithelial neoplasia, especially for distinguishing CIN1 from CIN2/3.</p

Symptom increase following a functional capacity evaluation in patients with chronic low back pain:An explorative study of safety

Introduction: This study was performed to study intensity and duration of symptom increase following an FCE and to explore safety of an FCE. Methods: Included were 92 patients with chronic low back pain (CLBP), mean age 38.5 years, mean self-reported disability 12.5 (Roland Morris Disability Questionnaire). All patients underwent an FCE. Symptom increase was measured with a 2-item questionnaire. Operational definition for safety: no formal complaint filed and symptom increase to occur only temporarily. Results: No formal complaints were filed (n=92). In total, 54 patients returned the questionnaire (59%; 'responders'). Of the responders, 76% reported increased symptom intensity after an FCE, ranging from 'little increase' to 'severe increase'. Symptoms of all responders returned to pre-FCE level. Duration of symptom increase of the responders ranged from 1 day to 3 weeks. Symptom increase resided to pre-FCE level within 1 week in 93% of the responders. Symptom increase was weakly related to self-reported disability (r=0.38, p <0.05). Except for gender, differences between responders and non-responders were non-significant. Conclusion: A temporary increase in symptom intensity following an FCE is common. Within the operational definitions of safety used in this study, assessment of functional capacity of patients with CLBP appears safe

Interactive Effects of Time, CO\u3csub\u3e2\u3c/sub\u3e, N, and Diversity on Total Belowground Carbon Allocation and Ecosystem Carbon Storage in a Grassland Community

Predicting if ecosystems will mitigate or exacerbate rising CO2 requires understanding how elevated CO2 will interact with coincident changes in diversity and nitrogen (N) availability to affect ecosystem carbon (C) storage. Yet achieving such understanding has been hampered by the difficulty of quantifying belowground C pools and fluxes. Thus, we used mass balance calculations to quantify the effects of diversity, CO2, and N on both the total amount of C allocated belowground by plants (total belowground C allocation, TBCA) and ecosystem C storage in a periodically burned, 8-year Minnesota grassland biodiversity, CO2, and N experiment (BioCON). Annual TBCA increased in response to elevated CO2, enriched N, and increasing diversity. TBCA was positively related to standing root biomass. After removing the influence of root biomass, the effect of elevated CO2 remained positive, suggesting additional drivers of TBCA apart from those that maintain high root biomass. Removing root biomass effects resulted in the effects of N and diversity becoming neutral or negative (depending on year), suggesting that the positive effects of diversity and N on TBCA were related to treatmentdriven differences in root biomass. Greater litter production in high diversity, elevated CO2, and enhanced N treatments increased annual ecosystem C loss in fire years and C gain in non-fire years, resulting in overall neutral C storage rates. Our results suggest that frequently burned grasslands are unlikely to exhibit enhanced C sequestration with increasing atmospheric CO2 levels or N deposition

Depleted 15N in hydrolysable-N of arctic soils and its implication for mycorrhizal fungi–plant interaction

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 97 (2009): 183-194, doi:10.1007/s10533-009-9365-1.Uptake of nitrogen (N) via root-mycorrhizal associations accounts for a significant portion of total N supply to many vascular plants. Using stable isotope ratios (δ15N) and the mass balance among N pools of plants, fungal tissues, and soils, a number of efforts have been made in recent years to quantify the flux of N from mycorrhizal fungi to host plants. Current estimates of this flux for arctic tundra ecosystems rely on the untested assumption that the δ15N of labile organic N taken up by the fungi is approximately the same as the δ15N of bulk soil. We report here hydrolysable amino acids are more depleted in 15N relative to hydrolysable ammonium and amino sugars in arctic tundra soils near Toolik Lake, Alaska, USA. We demonstrate, using a case study, that recognizing the depletion in 15N for hydrolysable amino acids (δ15N = -5.6 ‰ on average) would alter recent estimates of N flux between mycorrhizal fungi and host plants in an arctic tundra ecosystem.This study was funded by NSF-DEB-0423385and NSF-DEB 0444592. Additional support was provided by Arctic Long Term Ecological Research program, funded by National Science Foundation, Division of Environmental Biology