1,246 research outputs found
Linking Ground, Space and Knowledge: The Role of Weather Forecasting in Pastoralists\u27 Decision-Making
Changing weather patterns and decreasing land availability continue to challenge the livelihood of the pastoralists in northern Tanzania. The increasing variability of expected rains has complicated livestock management, often jeopardizing household resilience. Drought Early Warning Systems are being set up to contribute to decision-making processes at national and international levels. Nevertheless, due to the large spatial- and temporal resolution of these systems and their high uncertainties, these systems have limited value at a pastoral household level.
Therefore, this paper explores what type of weather and climate information is deemed valuable for pastoral households in Longido District, Tanzania. It is based on an ethnographic study, conducted over a period of four months. It explores what weather information would be useful, the necessary scale of desired information, the required lead time of communication and, lastly, the most effective method of communicating forecast information. Following on this data, the study assessed the status of remote sensing and weather forecast modelling, exploring the question, the desired weather information can be forecast with enough skill and at a scale that is relevant to pastoral households in Longido? The ECMWF weather model was used in the assessment, revealing some optimism and scepticism concerning the status of existing information and technologies.
Technological recommendations include verification of rainfall data, further research on the rainfall threshold concept, and exploring the model skill of embedded models in Tanzania. At the level of implementation , recommendations include discussing the adverse impacts of actions taken based on the forecasts and forming an implementation advisory group, which includes a comprehensive breadth of stakeholders, such as knowledgeable community members, village leaders, traditional leaders and also professionals from the field of climate sciences, rangeland ecology and anthropology
Instrumental Music Influences Recognition of Emotional Body Language
In everyday life, emotional events are perceived by multiple sensory systems. Research has shown that recognition of emotions in one modality is biased towards the emotion expressed in a simultaneously presented but task irrelevant modality. In the present study, we combine visual and auditory stimuli that convey similar affective meaning but have a low probability of co-occurrence in everyday life. Dynamic face-blurred whole body expressions of a person grasping an object while expressing happiness or sadness are presented in combination with fragments of happy or sad instrumental classical music. Participants were instructed to categorize the emotion expressed by the visual stimulus. The results show that recognition of body language is influenced by the auditory stimuli. These findings indicate that crossmodal influences as previously observed for audiovisual speech can also be obtained from the ignored auditory to the attended visual modality in audiovisual stimuli that consist of whole bodies and music
Heart rate increase and inappropriate sinus tachycardia after cryoballoon pulmonary vein isolation for atrial fibrillation
Background: Cryoballoon pulmonary vein isolation (PVI) is a common therapy for atrial fibrillation (AF). While moderately increased sinus rhythm heart rate (HR) after PVI has been observed, inappropriate sinus tachycardia (IST) is a rare phenomenon. We aimed to investigate the prevalence and natural history of an abnormal sinus HR response after cryoballoon PVI. Methods: We included 169/646 (26.2%) patients with AF undergoing PVI with available Holter recordings before and 3, 6 and 12 months after the procedure. Patients with AF on Holter monitoring were excluded. Mean HR increase >= 20 bpm or an IST-like pattern (mean HR > 90 bpm or > 80 bpm when beta-blocking agents were used) following PVI was categorised as abnormal sinus HR response. Results: Following PVI, mean HR +/- standard deviation increased in the entire group from 63.5 +/- 8.4 to 69.1 +/- 9.9 bpm at 3 months (p < 0.001), and to 71.9 +/- 9.4 bpm at 6 months (p < 0.001). At 12 months, mean HR was 71.2 +/- 10.1 bpm (p < 0.001). Only 7/169 patients (4.1%) met criteria for abnormal sinus HR response: mean HR was 61.9 +/- 10.6 bpm (pre-ablation), 84.6 +/- 9.8 bpm (3 months), 80.1 +/- 6.5 bpm (6 months) and 76.3 +/- 10.1 bpm (12 months). Even at 12 months, mean HR was significantly different from that pre-ablation in this group (p = 0.033). However, in patients meeting IST-like pattern criteria, mean HR at 12 months was no longer significantly different from that pre-ablation. Conclusion: Few patients had an abnormal sinus HR response after PVI. Peak HR was observed 3 months after PVI, but HR was still significantly increased 12 months post-ablation compared with pre-ablation. An IST-like pattern was rarely observed. In these patients, HR decreased to pre-ablation values within a year
On QBF Proofs and Preprocessing
QBFs (quantified boolean formulas), which are a superset of propositional
formulas, provide a canonical representation for PSPACE problems. To overcome
the inherent complexity of QBF, significant effort has been invested in
developing QBF solvers as well as the underlying proof systems. At the same
time, formula preprocessing is crucial for the application of QBF solvers. This
paper focuses on a missing link in currently-available technology: How to
obtain a certificate (e.g. proof) for a formula that had been preprocessed
before it was given to a solver? The paper targets a suite of commonly-used
preprocessing techniques and shows how to reconstruct certificates for them. On
the negative side, the paper discusses certain limitations of the
currently-used proof systems in the light of preprocessing. The presented
techniques were implemented and evaluated in the state-of-the-art QBF
preprocessor bloqqer.Comment: LPAR 201
Molecular profiles of BRCA1-mutated and matched sporadic breast tumours: relation with clinico-pathological features
About 5–10% of breast cancers are hereditary; a genetically and clinically heterogeneous disease in which several susceptibility genes, including BRCA1, have been identified. While distinct tumour features can be used to estimate the likelihood that a breast tumour is caused by a BRCA1 germline mutation it is not yet possible to categorize a BRCA1 mutated tumour. The aim of the present study is to molecularly classify BRCA1 mutated breast cancers by resolving gene expression patterns of BRCA1 and matched sporadic surgical breast tumour specimens. The expression profiles of 6 frozen breast tumour tissues with a proven BRCA1 gene mutation were weighed against those from 12 patients without a known family history but who had similar clinico-pathological characteristics. In addition two fibroblast cultures, the breast cancer cell-line HCC1937 and its corresponding B-lymphoblastoid cell line (heterozygous for mutation BRCA1 5382insC) and an epithelial ovarian cancer cell line (A2780) were studied. Using a high density membrane based array for screening of RNA isolated from these samples and standard algorithms and software, we were able to distinguish subgroups of sporadic cases and a group consisting mainly of BRCA1-mutated breast tumours. Furthermore this pilot analysis revealed a gene cluster that differentially expressed genes related to cell substrate formation, adhesion, migration and cell organization in BRCA1-mutated tumours compared to sporadic breast tumours. © 2001 Cancer Research Campaign http://www.bjcancer.co
Increased plasma levels of NT-proBNP, Troponin T and GDF-15 are driven by persistent AF and associated comorbidities:Data from the AF-RISK study
Atrial fibrillation (AF) is a progressive disease, and early recognition and management may reflect an important strategy to reduce its disease burden. In this study, we evaluated plasma levels of three biomarkers - N-terminal pro-brain natriuretic peptide (NTproBNP), Troponin-T, and growth differentiation factor-15 (GDF-15) - in patients with paroxysmal AF (pAF) (≤7 days of continuous AF, n = 323) and persistent AF ((AF duration > 7 days and < 1 year, n = 84) using patients from AF RISK study (NCT01510210). In this AF-RISK sub-study, patients with persistent AF experienced more symptoms (higher European Heart Rhythm Association class (p < 0.001)), had a higher comorbidity burden (p < 0.001), and had more unfavorable echocardiographic parameters (p < 0.001). All three biomarker levels were significantly higher in patients with persistent AF as compared to those with pAF (p < 0.001). Multivariate linear regression analyses showed that age (beta-coefficient for NTproBNP: 0.21; GDF-15: 0.41; Troponin-T: 0.23) and CHA2DS2-VASc (beta-coefficient for NTproBNP: 0.20; GDF-15: 0.25; Troponin-T: 0.27) were determinants of all three biomarkers, and that persistent AF determined NTproBNP (beta-coefficient: 0.34), but not Troponin-T and GDF-15. More detailed analysis of CHA2DS2-VASc score showed that for all three biomarkers age, coronary artery disease and heart failure were determinants of plasma biomarkers levels, whereas sex determined NTproBNP and Troponin T, and hypertension determined NTproBNP and GDF15. Overall, this study therefore suggests that in AF, Troponin T and GDF15, and especially NTproBNP could be used to detect those patients with more persistent form of AF that may warrant more aggressive treatment of AF and concomitant comorbidities. Future studies, however, are essential to evaluate if more aggressive AF treatment and risk factor management will reduce disease progression and holds a novel therapeutic intervention to reduce the burden of AF.</p
DepQBF 6.0: A Search-Based QBF Solver Beyond Traditional QCDCL
We present the latest major release version 6.0 of the quantified Boolean
formula (QBF) solver DepQBF, which is based on QCDCL. QCDCL is an extension of
the conflict-driven clause learning (CDCL) paradigm implemented in state of the
art propositional satisfiability (SAT) solvers. The Q-resolution calculus
(QRES) is a QBF proof system which underlies QCDCL. QCDCL solvers can produce
QRES proofs of QBFs in prenex conjunctive normal form (PCNF) as a byproduct of
the solving process. In contrast to traditional QCDCL based on QRES, DepQBF 6.0
implements a variant of QCDCL which is based on a generalization of QRES. This
generalization is due to a set of additional axioms and leaves the original
Q-resolution rules unchanged. The generalization of QRES enables QCDCL to
potentially produce exponentially shorter proofs than the traditional variant.
We present an overview of the features implemented in DepQBF and report on
experimental results which demonstrate the effectiveness of generalized QRES in
QCDCL.Comment: 12 pages + appendix; to appear in the proceedings of CADE-26, LNCS,
Springer, 201
Complex organic molecules in low-mass protostars on Solar System scales -- II. Nitrogen-bearing species
The chemical inventory of planets is determined by the physical and chemical
processes that govern the early phases of star formation. The aim is to
investigate N-bearing complex organic molecules towards two Class 0 protostars
(B1-c and S68N) at millimetre wavelengths with ALMA. Next, the results of the
detected N-bearing species are compared with those of O-bearing species for the
same and other sources. ALMA observations in Band 6 ( 1 mm) and Band 5
( 2 mm) are studied at 0.5" resolution, complemented by Band 3
( 3 mm) data in a 2.5" beam. NH2CHO, C2H5CN, HNCO, HN13CO, DNCO,
CH3CN, CH2DCN, and CHD2CN are identified towards the investigated sources.
Their abundances relative to CH3OH and HNCO are similar for the two sources,
with column densities that are typically an order of magnitude lower than those
of O-bearing species. The largest variations, of an order of magnitude, are
seen for NH2CHO abundance ratios with respect to HNCO and CH3OH and do not
correlate with the protostellar luminosity. In addition, within uncertainties,
the N-bearing species have similar excitation temperatures to those of
O-bearing species ( 100 300 K). The similarity of most abundances
with respect to HNCO, including those of CH2DCN and CHD2CN, hints at a shared
chemical history, especially the high D/H ratio in cold regions prior to star
formation. However, some of the variations in abundances may reflect the
sensitivity of the chemistry to local conditions such as temperature (e.g.
NH2CHO), while others may arise from differences in the emitting areas of the
molecules linked to their different binding energies in the ice. The two
sources discussed here add to the small number of sources with such a detailed
chemical analysis on Solar System scales. Future JWST data will allow a direct
comparison between the ice and gas abundances of N-bearing species.Comment: Accepted to A&A, 41 pages, 37 figure
Interpreting Overdiagnosis Estimates in Population-based Mammography Screening
Estimates of overdiagnosis in mammography screening range from 1% to 54%. This review explains such variations using gradual implementation of mammography screening in the Netherlands as an example. Breast cancer incidence without screening was predicted with a micro-simulation model. Observed breast cancer incidence (including ductal carcinoma in situ and invasive breast cancer) was modeled and compared with predicted incidence without screening during various phases of screening program implementation. Overdiagnosis was calculated as the difference between the modeled number of breast cancers with and the predicted number of breast cancers without screening. Estimating overdiagnosis annually between 1990 and 2006 illustrated the importance of the time at which overdiagnosis is measured. Overdiagnosis was also calculated using several estimators identified from the literature. The estimated overdiagnosis rate peaked during the implementation phase of screening, at 11.4% of all predicted cancers in women aged 0–100 years in the absence of screening. At steady-state screening, in 2006, this estimate had decreased to 2.8%. When different estimators were used, the overdiagnosis rate in 2006 ranged from 3.6% (screening age or older) to 9.7% (screening age only). The authors concluded that the estimated overdiagnosis rate in 2006 could vary by a factor of 3.5 when different denominators were used. Calculations based on earlier screening program phases may overestimate overdiagnosis by a factor 4. Sufficient follow-up and agreement regarding the chosen estimator are needed to obtain reliable estimates
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