Plant parasitic nematodes - problems related to clover and organic farming

Organic farming puts new and exciting challenges to the science of nematology. The occurrence of plant parasitic nematodes in organic farming systems needs to be investigated further. Good management strategies for nematodes should include monitoring of the composition and density of nematode populations. This would allow for increased yields and better sustainability of organic farming

Detailed and GlobalAnalysis of a Remedial Course's Impact on Incoming Students' Marks

Engineering incoming students are facing great difficulties to overcome first course subjects. To tackle that situation and increase the students’ success a Remedial course in Mathematics was offered to Informatics Engineering freshmen. This study presents a statistical analysis of their results comparing the marks obtained by those joining the course (studio group) versus those who did not participate (control group). ANOVA tests are performed over the students’ marks averages as well as over each subject students marks. These tests show statistically significant differences between both groups, with the studio group consistently outperforming the control group at 99% confidence level in most cases and at more than 92% confidence level in every case

The IACOB project. V. Spectroscopic parameters of the O-type stars in the modern grid of standards for spectral classification

The IACOB and OWN surveys are two ambitious complementary observational projects which have made available a large multi-epoch spectroscopic database of optical high resolution spectra of Galactic massive O-type stars. As a first step in the study of the full sample of (more than 350) O stars surveyed by the IACOB/OWN projects, we have performed the quantitative spectroscopic analysis of a subsample of 128 stars included in the modern grid of O-type standards for spectral classification. We use semi-automatized tools to determine the set of spectroscopic parameters that can be obtained from the optical spectrum of O-type stars. We also benefit from the multi-epoch character of the surveys to perform a spectroscopic variability study of the sample, accounting for spectroscopic binarity and variability of the main wind diagnostic lines. We provide a general overview of the stellar and wind parameters of this reference sample, and updated recipes for the SpT\,--\,Teff/log g calibrations for Galactic O-type stars. We evaluate our semi-automatized analysis strategy with $\sim$40 stars from the literature, and find a good agreement. The agreement between the synthetic spectra associated with fastwind best fitting models and the observed spectra is good for most targets, but 46 stars present a particular behavior of the wind diagnostic lines that cannot be reproduced by our grid of spherically symmetric unclumped models. These are potential targets of interest for more detailed investigations of clumpy winds and/or the existence of additional circumstellar components. Last, our variability study has led to the detection of signatures of spectroscopic binarity in 27\% of the stars and small amplitude radial velocity variations in the photospheric lines of another 30\%. Additionally, 31\% of the investigated stars show variability in the wind diagnostic lines.Comment: 20 pages, 18 figures, accepted for publication in Astronomy & Astrophysic

The IACOB project. VI. On the elusive detection of massive O-type stars close to the ZAMS

The apparent lack of massive O-type stars near the zero-age main sequence (at ages < 2 Myr) is a topic widely discussed. Different explanations for this elusive detection have been proposed, but no firm conclusions have been reached yet. We reassess this empirical result benefiting from the high-quality spectroscopic observations of >400 Galactic O-type stars gathered by the IACOB and OWN surveys. We used temperatures and gravities from a iacob-gbat/fastwind spectroscopic analysis to locate our sample in the Kiel and spectroscopic HR diagrams. We evaluated the completeness of our sample of stars, observational biases using information from the Galactic O star catalog (GOSC), systematics of our methodology, and compare with other recent studies using smaller samples of Galactic O-type stars. We base our discussion on the spectroscopic HR diagram to avoid the use of uncertain distances. We performed a detailed study of the young cluster Trumpler-14 as an example of how Gaia cluster distances can help to construct the associated classical HR diagram. The apparent lack of massive O-type stars near the ZAMS with masses between 30 and 70 Msol persist even when spectroscopic results from a large, non-biased sample of stars are used. We do not find correlation between the dearth of stars and observational biases, limitations of our methodology, or the use of spectroscopic HR diagram instead of the classical one. Investigating the efficiency of mass accretion during the formation process we conclude that an adjustment of the accretion rate towards lower values could reconcile the hotter boundary of detected O-type stars and the theoretical birthline. Last, we discuss that the presence of a small sample of O2-O3.5 stars found closer to the ZAMS might be explained taking into account non-standard star evolution (e.g. binary interaction, mergers, or homogeneous evolution).Comment: 20 pages, 15 figures, accepted for publication in Astronomy & Astrophysic

Size and shape of supported zirconia nanoparticles determined by x-ray photoelectron spectroscopy

6 pages, 7 figures, 1 table.-- PACS: 68.55.Ac; 68.55.Jk; 79.60.DpThe initial stages of growth of zirconia nanoparticles deposited on SiO2, Y2O3, and CeO2 substrates have been studied by the x-ray photoelectron spectroscopy peak shape analysis. ZrO2 was deposited by plasma decomposition of a volatile Zr(OtBu)4 precursor. The electronic interactions at each particular interface formed have been followed by means of the modified Auger parameter of the deposited Zr cations. They were quantified by means of Wagner plots and the chemical state vectors of the systems. The observed changes in these local electronic probes as the amount of deposit was increased have been correlated to the particular ZrO2 nanostructures identified on each substrate considered. A Volmer-Weber (islands) growth mechanism has been found for all the substrates considered. Moreover, clear indications have been found of a columnar growth for the case of ZrO2 deposited on SiO2.We thank the Spanish Ministry of Science and Education (MAT2004-01558) for financial support.Peer reviewe

Occurrence of C60 and related fullerenes in the Sava River under different hydrologic conditions

The presence of nanomaterials in the environment has caught the attention of the scientific because of the uncertainties in their fate, mobility and potential toxic effects. However, few studies have determined experimentally their concentration levels in aquatic systems up to date, which complicates the development of an adequate risk assessment. In the present study, the occurrence of ten fullerenes has been assessed in the Sava River (Southeastern Europe): 27 freshwater samples and 12 sediment samples from 12 sampling points have been analysed during two sampling campaigns. C was the most ubiquitous fullerene, with concentrations of 8 pg/l–59 ng/l and 108–895 pg/g in water and sediments, respectively. Statistically significant differences existed between the levels in 2014 and 2015, which has been attributed to the extreme hydrologic conditions (severe floods and drought, respectively). C fullerene has been detected in most of the samples and the fullerene derivatives [6,6]-phenyl C butyric acid methyl ester and N‑methyl fulleropyrrolidine have been detected eventually, which highlights that nanotechnology research and development activities are responsible for emitting these emerging contaminants to the environment. The role of diverse potential anthropogenic sources (including oil refinery, general industrial activity, river navigation, urban emissions and nanotechnology) is discussed

An Online Sales System to Be Managed by People with Mental Illness

The percentage of the population aged 65 and over is increasing during the last decades. It is one of the problems that the European health system, and in particular the Spanish system, has to face out. This increase is linked to the rising of dependent people, whose suffer progressive deterioration of both their physical and mental capacities. In this context, technology plays a key role in improving the quality of life, not only of older people but also their caregivers. A technological ecosystem to support patients with mental illness, their caregivers, and the connection with their relatives was developed in previous works. This solution is prepared to evolve according to the users’ and organization’s needs. In this sense, the present work describes the inclusion of a new software tool, an online sales platform that promotes active ageing, seeking that it can be used and managed by older people who may have cognitive impairment problems. Although there are many e-commerce platforms on the market, they not consider users with special needs. The objective has not been to develop a software prototype from scratch, but to focus on aspects relating to accessibility and usability to improve online stores and apply these improvements to an existing solution, following the philosophy of Open Source software development. This work aims to describe the definition process itself

Determination of texture by infrared spectroscopy in titanium oxide–anatase thin films

12 pages, 6 figures, 4 tables, 2 appendix.-- PACS: 68.55.Jk; 78.66.Nk; 78.30.HvA theoretical model to determine the effective dielectric tensor of heterogeneous materials composed by anisotropic microcrystallites has been introduced to explain the infrared spectral features of textured thin films of uniaxial materials as the function of a textural parameter. This theoretical treatment is able to satisfactorily reproduce the experimental absorbance spectra of TiO2–anatase thin films chosen as a model system. Comparison of texture data obtained from infrared spectroscopy and x-ray diffraction are in good agreement which support the validity of the proposed model.Peer reviewe

Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways

Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair. However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects. EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists. Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways. These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair

Identifying predictors of suicide in severe mental illness : a feasibility study of a clinical prediction rule (Oxford Mental Illness and Suicide tool or OxMIS)

Background: Oxford Mental Illness and Suicide tool (OxMIS) is a brief, scalable, freely available, structured risk assessment tool to assess suicide risk in patients with severe mental illness (schizophrenia-spectrum disorders or bipolar disorder). OxMIS requires further external validation, but a lack of large-scale cohorts with relevant variables makes this challenging. Electronic health records provide possible data sources for external validation of risk prediction tools. However, they contain large amounts of information within free-text that is not readily extractable. In this study, we examined the feasibility of identifying suicide predictors needed to validate OxMIS in routinely collected electronic health records. Methods: In study 1, we manually reviewed electronic health records of 57 patients with severe mental illness to calculate OxMIS risk scores. In study 2, we examined the feasibility of using natural language processing to scale up this process. We used anonymized free-text documents from the Clinical Record Interactive Search database to train a named entity recognition model, a machine learning technique which recognizes concepts in free-text. The model identified eight concepts relevant for suicide risk assessment: medication (antidepressant/antipsychotic treatment), violence, education, self-harm, benefits receipt, drug/alcohol use disorder, suicide, and psychiatric admission. We assessed model performance in terms of precision (similar to positive predictive value), recall (similar to sensitivity) and F1 statistic (an overall performance measure). Results: In study 1, we estimated suicide risk for all patients using the OxMIS calculator, giving a range of 12 month risk estimates from 0.1-3.4%. For 13 out of 17 predictors, there was no missing information in electronic health records. For the remaining 4 predictors missingness ranged from 7-26%; to account for these missing variables, it was possible for OxMIS to estimate suicide risk using a range of scores. In study 2, the named entity recognition model had an overall precision of 0.77, recall of 0.90 and F1 score of 0.83. The concept with the best precision and recall was medication (precision 0.84, recall 0.96) and the weakest were suicide (precision 0.37), and drug/alcohol use disorder (recall 0.61). Conclusions: It is feasible to estimate suicide risk with the OxMIS tool using predictors identified in routine clinical records. Predictors could be extracted using natural language processing. However, electronic health records differ from other data sources, particularly for family history variables, which creates methodological challenges