152 research outputs found
Anatomy of Malicious Singularities
As well known, the b-boundaries of the closed Friedman world model and of
Schwarzschild solution consist of a single point. We study this phenomenon in a
broader context of differential and structured spaces. We show that it is an
equivalence relation , defined on the Cauchy completed total space
of the frame bundle over a given space-time, that is responsible for
this pathology. A singularity is called malicious if the equivalence class
related to the singularity remains in close contact with all other
equivalence classes, i.e., if for every . We
formulate conditions for which such a situation occurs. The differential
structure of any space-time with malicious singularities consists only of
constant functions which means that, from the topological point of view,
everything collapses to a single point. It was noncommutative geometry that was
especially devised to deal with such situations. A noncommutative algebra on
, which turns out to be a von Neumann algebra of random operators,
allows us to study probabilistic properties (in a generalized sense) of
malicious singularities. Our main result is that, in the noncommutative regime,
even the strongest singularities are probabilistically irrelevant.Comment: 16 pages in LaTe
Systematic Scoring Balloon Lesion Preparation for Drug-Coated Balloon Angioplasty in Clinical Routine: Results of the PASSWORD Observational Study
INTRODUCTION: Scoring balloon angioplasty (SBA) for lumen gain prior to stent implantations or drug-coated balloon angioplasty (DCB) is considered an essential interventional tool for lesion preparation. Recent evidence indicates that SBA may play a pivotal role in enhancing the angiographic and clinical outcomes of DCB angioplasty. METHODS: We studied the systematic use of SBA with a low profile, non-slip element device prior to DCB angioplasty in an unselected, non-randomized patient population. This prospective, all-comers study enrolled patients with de novo lesions as well as in-stent restenotic lesions in bare metal stents (BMS-ISR) and drug-eluting stents (DES-ISR). The primary endpoint was the target lesion failure (TLF) rate at 9 months (ClinicalTrials.gov Identifier NCT02554292). RESULTS: A total of 481 patients (496 lesions) were recruited to treat de novo lesions (78.4%, 377), BMS-ISR (4.0%, 19), and DES-ISR (17.6%, 85). Overall risk factors were acute coronary syndrome (ACS, 20.6%, 99), diabetes mellitus (46.8%, 225), and atrial fibrillation (8.5%, 41). Average lesion lengths were 16.7 +/- 10.4 mm in the de novo group, and 20.1 +/- 8.9 mm (BMS-ISR) and 16.2 +/- 9.8 mm (DES-ISR) in the ISR groups. Scoring balloon diameters were 2.43 +/- 0.41 mm (de novo), 2.71 +/- 0.31 mm (BMS-ISR), and 2.92 +/- 0.42 mm (DES-ISR) whereas DCB diameters were 2.60 +/- 0.39 mm (de novo), 3.00 +/- 0.35 mm (BMS-ISR), and 3.10 +/- 0.43 mm (DES-ISR), respectively. The overall accumulated TLF rate of 3.0% (14/463) was driven by significantly higher target lesion revascularization rates in the BMS-ISR (5.3%, 1/19) and the DES-ISR group (6.0%, 5/84). In de novo lesions, the TLF rate was 1.1% (4/360) without differences between calcified and non-calcified lesions (p = 0.158) and small vs. large reference vessel diameters with a cutoff value of 3.0 mm (p = 0.901). CONCLUSIONS: The routine use of a non-slip element scoring balloon catheter to prepare lesions suitable for drug-coated balloon angioplasty is associated with high procedural success rates and low TLF rates in de novo lesions
Self-organization of developing embryo using scale-invariant approach
<p>Abstract</p> <p>Background</p> <p>Self-organization is a fundamental feature of living organisms at all hierarchical levels from molecule to organ. It has also been documented in developing embryos.</p> <p>Methods</p> <p>In this study, a scale-invariant power law (SIPL) method has been used to study self-organization in developing embryos. The SIPL coefficient was calculated using a centro-axial skew symmetrical matrix (CSSM) generated by entering the components of the Cartesian coordinates; for each component, one CSSM was generated. A basic square matrix (BSM) was constructed and the determinant was calculated in order to estimate the SIPL coefficient. This was applied to developing <it>C. elegans </it>during early stages of embryogenesis. The power law property of the method was evaluated using the straight line and Koch curve and the results were consistent with fractal dimensions (fd). Diffusion-limited aggregation (DLA) was used to validate the SIPL method.</p> <p>Results and conclusion</p> <p>The fractal dimensions of both the straight line and Koch curve showed consistency with the SIPL coefficients, which indicated the power law behavior of the SIPL method. The results showed that the ABp sublineage had a higher SIPL coefficient than EMS, indicating that ABp is more organized than EMS. The fd determined using DLA was higher in ABp than in EMS and its value was consistent with type 1 cluster formation, while that in EMS was consistent with type 2.</p
Meeting Report: ESC Forum on Drug Eluting Stents European Heart House, Nice, 27-28 September 2007
Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations
BACKGROUND: The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers. METHOD: In study populations of 3161 adults, comprising Greenlandic Inuits, Swedish fishermen and their wives, and inhabitants from Warsaw, Poland and Kharkiv, Ukraine, serum concentrations of CB-153 and p,p'-DDE, were analysed by gas chromatography-mass spectrometry. RESULTS: The median serum concentrations of CB-153 were for male and female Inuits 200 and 110, for Swedish fishermen 190 and their wives 84, for Kharkiv men and women 44 and 27, and for Warsaw men and women 17 and 11 ng/g lipids, respectively. The median serum concentrations of p,p'-DDE were for Kharkiv men and women 930 and 650, for male and female Inuits 560 and 300, for Warsaw men and women 530 and 380, and for Swedish fishermen 240 and their wives 140 ng/g lipids, respectively. The correlation coefficients between CB-153 and p,p'-DDE varied between 0.19 and 0.92, with the highest correlation among Inuits and the lowest among men from Warsaw. Men had averagely higher serum concentrations of CB-153 and p,p'-DDE, and there were positive associations between age and the POP-biomarkers, whereas the associations with BMI and smoking were inconsistent. Dietary seafood was of importance only in the Inuit and Swedish populations. CONCLUSION: CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations
Applicability of non-invasively collected matrices for human biomonitoring
With its inclusion under Action 3 in the Environment and Health Action Plan 2004–2010 of the European Commission, human biomonitoring is currently receiving an increasing amount of attention from the scientific community as a tool to better quantify human exposure to, and health effects of, environmental stressors. Despite the policy support, however, there are still several issues that restrict the routine application of human biomonitoring data in environmental health impact assessment. One of the main issues is the obvious need to routinely collect human samples for large-scale surveys. Particularly the collection of invasive samples from susceptible populations may suffer from ethical and practical limitations. Children, pregnant women, elderly, or chronically-ill people are among those that would benefit the most from non-invasive, repeated or routine sampling. Therefore, the use of non-invasively collected matrices for human biomonitoring should be promoted as an ethically appropriate, cost-efficient and toxicologically relevant alternative for many biomarkers that are currently determined in invasively collected matrices. This review illustrates that several non-invasively collected matrices are widely used that can be an valuable addition to, or alternative for, invasively collected matrices such as peripheral blood sampling. Moreover, a well-informed choice of matrix can provide an added value for human biomonitoring, as different non-invasively collected matrices can offer opportunities to study additional aspects of exposure to and effects from environmental contaminants, such as repeated sampling, historical overview of exposure, mother-child transfer of substances, or monitoring of substances with short biological half-lives
Raspodjela lindana u vodi, sedimentu i ribama iz rijeke Warri (Delta Nigera, Nigerija)
This paper is the first attempt to quantify the levels and the distribution pattern of lindane in the surface water, sediment and fish (Chrysichthys furcatus and Tilapia zilli). The samples were collected from three stations (Ovwian, Ekakpamre, and Ovu) of the Warri River in the western Niger Delta of Nigeria in 2006: during the dry (January-April) and wet seasons (May-August). The analysis included a total of 96 samples made up of 24 samples each for water, sediment, and fish. The pesticide levels were analysed using high performance liquid chromatography to elucidate its distribution in various environmental compartments. Residue levels in the matrices ranged from below the detection limit (BDL) to 1.37µg L-1 in water, BDL to 12.66 µg g-1 dry weight (dw) in sediment, BDL to 16.67 µg g-1dw in Chrysichthys furcatus, and BDL to 0.15 µg g-1dw in Tilapia zilli .The observed values were above the ecological benchmarks (0.01 µg L-1) recommended by the Nigerian Environmental Protection Agency and European Union. They were also relatively higher than in previous studies on the Nigerian environment, which calls for regular monitoring of the Niger Delta water bodies.Istražene su pojava i raspodjela lindana u površinskoj vodi, sedimentu i dvije vrste riba Chrysichthys furcatus i Tilapia zilli iz rijeke Warri u zapadnom dijelu delte Nigera (Nigerija). Uzorci su skupljeni 2006. godine na tri postaje (Ovwian, Ekakpamre i Ovu) tijekom sušne (siječanj - travanj) i vlažne sezone (svibanj - kolovoz). Analizirano je ukupno 96 uzoraka: po 24 uzorka vode, sedimenta i riba. Razine pesticida odre|ene su primjenom tekućinske kromatografije visoke djelotvornosti (HPLC) te je utvr|ivana njihova raspodjela u različitim dijelovima okoliša. Koncentracije rezidua u uzorcima vode bile su u rasponu: ispod granice detekcije (BDL) do 1,37 µg L-1, u sedimentu: BDL do 12,66 µg g-1 suhe tvari, u ribama Chrysichthys furcatus: BDL do 16,67 µg g-1 suhe tvari te Tilapia zilli: BDL do 0,15 µg g-1 suhe tvari. Određene vrijednosti bile su ispod graničnih vrijednosti (0,01 µg L-1) propisanih od Nigerijske uprave za zaštitu okoliša i Europske unije. Kako su dobivene vrijednosti bile relativno više u odnosu na podatke iz ranijih istraživanja okoliša u Nigeriji, istaknuta je potreba trajnog monitoringa vodotoka u delti Nigera
Preparation and Characterization of Superparamagnetic Molecularly Imprinted Polymers for Selective Adsorption and Separation of Vanillin in Food Samples
- …