Competition and Predation in Soil Fungivorous Microarthropods Using Stable Isotope Ratio Mass Spectrometry

The soil food web is often described as having three main energy channels: root, bacterial and fungal. Here we provide quantitative data using a sensitive stable isotope ratio mass spectrometry procedure with microcosms on species interactions in the fungal pathway. We measured 15N and 13C enrichment in microarthropods through grazing rare isotope enriched fungal mycelia. Experimental treatments were various combinations of 1, 2, 3, 4 microarthropods species. We used three fungivores (the collembolan Lepidocyrtus curvicollis, the Astigmata Tyrophagus putrescentiae, the Oribatida Oribatula tibialis.), and the Mesostigmata predator Hypoaspis acquilifer We collected individuals of each species separately, as well as their faeces, and moult where available. All three fungivorous microarthropods consumed significantly more than their own body weight per day. The three fungivores differed in their consumption of the mycelium as it was not equally palatable to each. The Mesostigmata predator Hypoaspis also differed in its microarthropod prey preference. In multiple species combinations microarthropod behavioural interactions modified consumption and predation rates. Our selection of mites of different sizes, with varied preference for the mycelium, combined with differing predation rates on each mite, demonstrate that even three trophic level interactions with only five interacting species are not predictably simple. The interpretation of the stable isotope results and consumed-excreted weights indicate that: a) behaviour and microscopic observations should not be ignored in competition-predation interactions, and b) functional guilds can take advantage of more diverse food opportunities. The reality of mixed diets complicates functional guild assignments that are reflected in 15N and 13C isotope levels at natural abundances in the environment. Microcosm experiments with this sensitive technique can help decipher the interpretation of rare isotope natural abundance values, as well as providing measured consumption, growth, and excretion rate values for modelling soil food web interactions

Biomarkers in Parkinson disease: studies on clinical, radiological and biological biomarkers

Parkinson disease is the second most common neurodegenerative disorder after Alzheimer disease. It affects 2 to 3 percent of those over 65 years with an age-dependent prevalence. Currently, the diagnosis of PD is hampered by the limited sensitivity and specificity of the available investigations. The diagnosis is usually made based on the clinical presentation which has a number of significant limitations. First of all, the disease has been present for decades before motor symptoms develop. Secondly, using clinical exam alone, the misdiagnosis rate remains high with both over-and under-diagnosis common. It is important to make an expeditious and correct diagnosis of PD, especially in this era of increasing interest in neuroprotective strategies for PD and other neurodegenerative conditions. Delaying the diagnosis until motor symptoms develop is suboptimal as more than 40% of dopaminergic neurons have been destroyed at this stage. We also need to ensure that true cases of PD are being enrolled in PD trials and that these trials are not being confounded by the inclusion of individuals with other causes of parkinsonism. To accomplish these goals, there is a need for PD biomarkers that are both sensitive and specific. The objective of this thesis was to investigate, using a case-control study design, a number of potential biomarkers for PD. These biomarkers included clinical, biological and radiological markers. In the first study, we investigated the role of autonomic neuropathy as a clinical biomarker for PD. Using thermal threshold testing, nerve conduction testing and questionnaires, the PD group demonstrated a higher prevalence of autonomic neuropathy. Other outcome measures, including the presence of non-motor symptoms, pain, depressive symptoms and electrophysiological evidence of large fiber neuropathy were also found to be more prevalent in the PD group. In the second and third studies, we explored the potential role of CSF biological biomarkers in PD. In the second study, we evaluated CSF cytokine levels with the aim of identifying a unique cytokine pattern in the CSF of PD subjects. We failed to detect a cytokine pattern and found no difference in cytokine levels between PD and control groups. However, within a cohort of the PD group, we identified an association between IL-2 levels and disease severity, with higher concentrations of IL-2 seen in those with more severe disease. In the third study, we measured GDF5 protein levels in the CSF and found lower concentrations of GDF5 in the PD group compared to controls. GDF5 levels were lower in the female PD subjects compared to males. There was no association between GDF5 concentrations and PD characteristics, age or cognition. In the final study, we assessed the utility of SPECT imaging of dopamine transporters in the striatal region of the brain (DaTSCAN) as a radiological biomarker for PD in our healthcare system. Following a review of scans over a five-year period, 69% of scans showed evidence of dopaminergic deficit, supporting a diagnosis of PD. Review of request forms for DaTSCAN, demonstrated inappropriate referrals in 13% of cases. Chart review in a subgroup of scans documented a change in patient management in 65% of cases, based on the result of the scan. In this thesis, we sought to identify potential biomarkers for PD. We found significant differences between the subjects with PD and controls using clinical and biological tests. We also demonstrated findings that support the utility of a radiological biomarker in clinical practice. Our studies showed promising results and require further research. In the future, we envision studies investigating a multimodal biomarker approach in large cohorts of PD subjects

Enhanced signal of astrophysical tau neutrinos propagating through Earth

Earth absorbs \nue and \numu of energies above about 100 TeV. As is well-known, although \nutau will also disappear through charged-current interactions, the \nutau flux will be regenerated by prompt tau decays. We show that this process also produces relatively large fluxes of secondary \nube and \nubmu, greatly enhancing the detectability of the initial \nutau. This is particularly important because at these energies \nutau is a significant fraction of the expected astrophysical neutrino flux, and only a tiny portion of the atmospheric neutrino flux.Comment: Four pages, two inline figure

Scenario Based Methodologies in Identifying Ubicomp Application Sets

In ubiquitous systems of the future, a requirement for appropriate methods for the selection, analysis and evaluation of applications is evident. Traditional methods of analysis rely heavilyon the inherent predictability of the system, something which is totally lacking in ubiquitous systems. This paper discusses one possible approach to flexible analysis and evaluation, the ScenarioBased Approach, describing its use in the IST FP6 project, Daidalos. The Scenario Based approach addresses the adaptive nature of ubiquitous systems by its own intrinsic flexibility. This paper explains the approach and argues that it is appropriate that a method of analysis should exhibit similar characteristics to the object of that analysis

Effects of cover crops on phosphatase activity in a clay arable soil in the UK

The effect of five cover crop species (radish, buckwheat, vetch, phacelia and oat) alongside an un-cropped control, on the activity and persistence of soil acid and alkaline phosphatase activity was investigated. There was no effect on alkaline phosphatase activity at the time of cover crop incorporation (March), but by the point of maturation of the following oat cash crop (June) significant differences were detected, with the greatest activity following an oat cover crop. Acid phosphatase activity showed species-related significant differences at both sampling dates, with the magnitude increasing by June. Again, plots following an oat cover crop showed the greatest activity, followed by phacelia. This has shown that soil phosphatase enzymes are affected by the presence of a cover crop, that this effect is apparently species-dependent – and not dependent on the amount of biomass from the cover crop – and that cover crops could be a potential means to enhance soil phosphorus cycling

Advanced Photodetectors for Hyperspectroscopy and Other Applications

Hyperspectroscopy is a new method of surface image taking, providing simultaneously high position and spectral resolutions which allow one to make some conclusions about chemical compositions of the surfaces. We are now studying applications of the hyperspctroscopic technique to be used for medicine. This may allow one to develop early diagnostics of some illnesses, as for example, skin cancer. For image taking advanced MCPs are currently used, sensitive in the spectral interval of 450-850 nm. One of the aims of this work is to extend the hyperspectrocpic method to the UV region of spectra: 185-280 nm. For this we have developed and successfully tested innovative 1D and 2D UV sealed photosensitive gaseous detectors with resistive electrodes. These detectors are superior MCPs due to the very low rate of noise pulses and thus due to the high signal to noise ratio. Other important features of these detectors are that they have excellent position resolutions - 30 micron in digital form, are vibration stable and are spark protected. The first results from the application of these detectors for spectroscopy, hyperspectroscopy and the flame detection are presented.Comment: Presented at the IEEE Nuclear Science Syposium, Puerto Rico, October 200

Participatory research approaches to integrating scientific and farmer knowledge of soil to meet multiple objectives in the English East Midlands

Soil management influences food production, economic performance of farm businesses, and a range of public benefits such as water quality, flood control and aquatic and terrestrial biodiversity. The aim of this paper is to explore the role of participatory research in combining scientific and farmer knowledge of soils to meet these multiple objectives. We use five separate research studies involving communication, consultation and co‐production, carried out in the English East Midlands between 2014 and 2018.We compare the participatory processes for knowledge exchange and their material outcomes and assess them retrospectively against specified criteria for successful application of participatory research. We conclude that, depending on context and scalar fit, multiple approaches to participatory research can be complementary, strengthen engagement and build trust within a farming community, resulting in a greater shared understanding of how to address the soil management objectives of farmers and wider society

Transcriptomic responses in the blood and sputum of cigarette smokers compared to e-cigarette vapers.

RATIONALE: Electronic (e)-cigarettes are popular among youth and cigarette smokers attempting to quit. Studies to date have focused on the utility of e-cigarettes as a smoking cessation tool, but the biological effects are largely unknown. OBJECTIVES: To identify transcriptomic differences in the blood and sputum of e-cigarette users compared to conventional cigarettes smokers and healthy controls and describe biological pathways affected by these tobacco products. METHODS: Cross-sectional analysis of whole blood and sputum RNA-sequencing data from 8 smokers, 9 e-cigarette users (e-cigs) and 4 controls. Weighted gene co-network analysis (WGCNA) identified gene module associations. Ingenuity Pathway Analysis (IPA) identified canonical pathways associated with tobacco products. MAIN RESULTS: In blood, a three-group comparison showed 16 differentially expressed genes (DEGs); pair-wise comparison showed 7 DEGs between e-cigs and controls, 35 DEGs between smokers and controls, and 13 DEGs between smokers and e-cigs. In sputum, 438 DEGs were in the three-group comparison. In pair-wise comparisons, there were 2 DEGs between e-cigs and controls, 270 DEGs between smokers and controls, and 468 DEGs between smokers and e-cigs. Only 2 genes in the smokers vs. control comparison overlapped between blood and sputum. Most gene modules identified through WGCNA associated with tobacco product exposures also were associated with cotinine and exhaled CO levels. IPA showed more canonical pathways altered by conventional cigarette smoking than by e-cigarette use. CONCLUSION: Cigarette smoking and e-cigarette use led to transcriptomic changes in both blood and sputum. However, conventional cigarettes induced much stronger transcriptomic responses in both compartments

The utility of dopamine transporter scans for diagnosing Parkinsonian disorders

Introduction: Dopamine transporter scans are increasingly being used in the diagnosis of clinically undefined Parkinsonism. Aims: To assess the indications for imaging usage and its impact on future clinical management. Methods: Retrospective review of scans ordered and their corresponding results over a five-year period. A chart review was carried out on a cohort of scans to assess changes in clinical management. Results: One hundred and eighty scans (69% of total) were reported as showing evidence of dopaminergic deficit. A chart review in 81 patients showed a change in clinical management in 53 patients (65%). Scans were ordered inappropriately in 34 patients (13%). Discussion: 123I-FP-CIT SPECT scans are being more frequently ordered and if used correctly can alter clinical management. Increased education on indications for use is required to reduce waste of resources and risk to patients

The effect of crop residues, cover crops, manures and nitrogen fertilization on soil organic carbon changes in agroecosystems: a synthesis of reviews

International initiatives are emphasizing the capture of atmospheric CO2 in soil organic C (SOC) to reduce the climatic footprint from agroecosystems. One approach to quantify the contribution of management practices towards that goal is through analysis of long-term experiments (LTEs). Our objectives were to analyze knowledge gained in literature reviews on SOC changes in LTEs, to evaluate the results regarding interactions with pedo-climatological factors, and to discuss disparities among reviews in data selection criteria. We summarized mean response ratios (RRs) and stock change rate (SCR) effect size indices from twenty reviews using paired comparisons (N). The highest RRs were found with manure applications (30%, N = 418), followed by aboveground crop residue retention and the use of cover crops (9–10%, N = 995 and 129), while the effect of nitrogen fertilization was lowest (6%, N = 846). SCR for nitrogen fertilization exceeded that for aboveground crop residue retention (233 versus 117 kg C ha−1 year−1, N = 183 and 279) and was highest for manure applications and cover crops (409 and 331 kg C ha−1 year−1, N = 217 and 176). When data allows, we recommend calculating both RR and SCR because it improves the interpretation. Our synthesis shows that results are not always consistent among reviews and that interaction with texture and climate remain inconclusive. Selection criteria for study durations are highly variable, resulting in irregular conclusions for the effect of time on changes in SOC. We also discuss the relationships of SOC changes with yield and cropping systems, as well as conceptual problems when scaling-up results obtained from field studies to regional levels