Self-Reference and Diagonalisation

This poem is an exercise on self-reference and diagonalisation in mathematics featuring Turing’s proof of the undecidability of the halting problem, Cantor’s cardinality argument, the Burali-Forti paradox, and Epimenides\u27 liar paradox

Europium-doped calcium pyrophosphates : allotropic forms and photoluminescent properties

In a search for new luminescent biological probes, we synthesized calcium pyrophosphates doped with europium up to an atomic Eu/(Eu+Ca) ratio of 2%. They were prepared by coprecipitating a mixture of calcium and europium salts with phosphate. After heating at 900°C in air, two phases coexisted, identified as the β calcium pyrophosphate form and EuPO4. Heating near 1250°C in air, during the β→ transformation, europium ions substitute for calcium ions in the * calcium pyrophosphate structure as demonstrated by the spectroscopic study. Europium ions with both valence states (divalent and trivalent) were observed in the samples. Following the synthesis procedure, partial reduction of Eu3+ took place even in an oxidizing atmosphere. The 0.5%-doped compound could serve as a sensitive probe in biological applications. Depending on the excitation wavelength, the luminescence occurs either in the red or in the blue regions, which discriminates it from parasitic signals arising from other dyes or organelles in live cells

Projet : Béton d'Argile Environnemental (B.A.E.): Rapport scientifique

Rapport scientifiqueLa terre est un matériau à changement de phase naturel, localement disponible, à faible énergie griseet recyclable. Ces qualités en font un matériau de construction d’avenir.La physique et la mécanique de la matière divisée (et ultra divisée) sont des domaines en plein essor.L’éclosion des nanosciences offre un nouvel éclairage sur les comportements mécaniques, thermiques,hygrométriques et rhéologiques du matériau terre, en particulier aux échelles physico-chimiques lesplus fines des argiles.A cet apport de connaissances théoriques s’ajoute un savoir-faire industriel très élaboré pour la miseen oeuvre de matériaux offrant de nombreux points communs avec la terre, véritable béton d’argile.Ainsi, les méthodes appliquées à la confection de bétons de ciment toujours plus performants d’unepart et celles appliquées au coulage des crus des céramiques industrielles d’autre part sonttransférables au matériau terre.D’autre part, le marché spécialisé de la construction en terre s’organise et se développe rapidement. Acela s’ajoute une demande sociétale toujours plus forte qui conduit par exemple les industriels de labrique cuite à proposer des briques crues. Les carrières de granulats souhaitent quant à elles valoriserleurs importants volumes de coproduits de carrières (fines argilo-calcaires).Les conditions sont donc réunies pour mettre en place à l’échelle nationale, à l’instar de la filière bois,une filière terre qui s'appuie sur des bases scientifiques et techniques approfondies.L’enjeu scientifique réside notamment dans une meilleure compréhension des propriétés mécaniqueset thermiques du matériau terre en liaison avec son comportement hygrométrique d’une part et unemeilleure connaissance des systèmes argile/eau en vue du coulage du matériau terre à l’état liquided’autre part. Il réside également dans une meilleure compréhension de la cohésion du matériau et del’amélioration de cette cohésion par ajout de polymères : les nanocomposites argile/polymère sont, dece point de vue, exemplaires.ObjectifsLe projet s’articule autour de 6 objectifs :1. établir un état de l’art et une synthèse des caractéristiques mécaniques, thermiques ethygrométriques du matériau terre en vue de l’élaboration de règles professionnelles.2. étudier l’influence de la densité, de l’organisation spatiale du réseau poreux et de l’humidité relativesur les caractéristiques mécaniques et thermiques : ce sont 3 paramètres clés de la dispersion desvaleurs données par la littérature.3. transférer d’une part la technologie des superplastifiants du béton de ciment afin de mettre enoeuvre la terre à l’état liquide et d’autre part la Direct Coagulation Casting (DCC) de l’industriecéramique afin de solidifier la terre après coulage par coagulation des argiles.4. formuler de nouveaux liants argiles / biopolymères pour la confection de nouveaux bétons, briques,enduits et peintures très écologiques.5. Evaluer l’intérêt de l’ajout de particules végétales poreuses pour optimiser les performances(mécaniques et thermiques) de ces bétons.6. Valoriser les coproduits de carrières de granulats en les transformant en matériaux de constructionterre innovants

Long-term (10 years) prognostic value of a normal thallium-201 myocardial exercise scintigraphy in patients with coronary artery disease documented by angiography

In order to assess the prognostic significance of normal exercise thallium-210 myocardial scintigraphy in patients with documented coronary artery disease, we studied the incidence of cardiac death and non-fatal myocardial infarction in 69 symptomatic patients without prior Q wave myocardial infarction, who demonstrated one or more significant coronary lesions (stenosis ≤70%) on an angiogram performed within 3 months of scintigraphy (Group 1). These patients were compared to a second group of 136 patients with an abnormal exercise scintigram, defined by the presence of reversible defect(s) and angiographically proven coronary artery disease (Group 2), and to a third group of 102 patients with normal exercise scintigraphy without significant coronary lesions (stenosis ≥30%) or with normal coronary angiography (Group 3). In contrast to coronary lesions observed in Group 2, patients in Group I presented more frequently with single- vessel disease (83% vs 35%, P>0·0001) and with more distal lesions (55% vs 23%, P>0·0001). Over a mean follow-up period of 8·6 years, one fatal and eight non-fatal cases of myocardial infarction were observed in Group 1. The majority of patients in Group 1 were treated medically: only 24 (35%) underwent myocardial revascularization, usually by coronary angioplasty. There was no significant difference in the incidence of combined major cardiac events (cardiac death, non-fatal myocardial infarction) in patients with normal exercise scintigraphy, with or without documented coronary artery disease (Groups 1 and 3), while the incidence was higher in Group 2. However, while the mortality remained very low in Group 1, the incidence of non-fatal myocardial infraction was not different from that of Group 2, where most patients underwent revascularization procedures. In conclusion, patients with coronary artery disease and a normal exercise thallium-201 myocardial scintigram usually have mild coronary lesions (single-vessel disease, distal location) and good long-term prognosis, with a low incidence of cardiac deat

The use of emergency contraception among female senior high students in the Ho municipality of the Volta Region, Ghana

Background: Emergency contraception (EC) is one option for preventing unplanned pregnancy when it is available and properly used. Unsafe abortions are responsible for nearly one third of maternal deaths in sub-Saharan Africa and about quarter of unsafe abortions are among teenagers.Methods: A quantitative descriptive cross-sectional study. Data was collected using a pretested questionnaire. 260 senior high students were selected using a systematic sampling method in the Volta Region, Ghana. Data were cleaned and entered into SPSS version 22 and analysed into descriptive statistics.Results: Respondents acquired awareness about EC from friends (36.9%), family members (5.6%) and the mass media (41.6%). The required time for EC to be taken were stated as immediately after sex (57.9%), 24 hours after sex (1.2%) and (30.6%) did not know. 28.4% of participants indicated they would not use EC in the future as their faith was against it, 18.0% believed EC is ineffective and 24.9% consider it dangerous to their health. Reasons for use of EC included condom slipped (35.7%), inability to be on daily pill (33.7%), forced unprotected sex (8.2%) and miscalculation of the safe menstrual period (22.4%). There was a significant relationship between age and history of use of EC (p=0.000, c2=8.128, n=260).Conclusions: Strengthening education in Senior High Schools on sexual and reproductive health, with special emphasis on emergency contraceptives as a pregnancy preventive procedure will remain imperative to reducing the canker of maternal mortality attributed to adolescent abortions while improving understanding of the appropriate use of EC

Knowledge of pregnant women on the factors that influence anaemia in pregnancy in a rural farming district of the Western Region of Ghana

Background: The presence of anaemia in pregnancy is one of the serious public health concerns across the globe especially in developing countries like Ghana. This study assessed pregnant women's knowledge on factors influencing aneamia in pregnancy in a low-income district of Ghana.Methods: A quantitative descriptive cross-sectional study. Data was collected using a pretested questionnaire. 112 pregnant women seeking antenatal care were recruited using systematic sampling technique in the Wassa East district of Ghana. Data were cleaned and entered into SPSS version 22 and analysed into descriptive statistics.Results: Majority of participants; 72.3% did not know the causes of anaemia in pregnancy. Pregnant women (27.7%) indicated nutritional deficiency as a common cause of anaemia; 18.7% of them could identify appropriately at least one sign of anaemia in pregnancy with 28% asserting that pregnancy-related anaemia can affect labour, despite 72% indicating that anaemia could cause maternal mortality. The reasons for irregular ANC attendance included; perceived non importance of ANC (18.8%), financial difficulties (17.9%), health facility inaccessibility (18.8%) and time constraints (44.5%). There was a strong association between knowledge level on the cause of anaemia in pregnancy and the educational level of pregnant women (p=0.005 chi square = 50.289).Conclusions: Lack of knowledge on the importance of antenatal care and financial constraints were among the reasons leading to a surge in anaemia amongst pregnant women in the district. Health providers should incorporate services which enable pregnant women to access valuable information on anaemia prevention in pregnancy

Stable transmission of targeted gene modification using single-stranded oligonucleotides with flanking LNAs

Targeted mutagenesis directed by oligonucleotides (ONs) is a promising method for manipulating the genome in higher eukaryotes. In this study, we have compared gene editing by different ONs on two new target sequences, the eBFP and the rd1 mutant photoreceptor βPDE cDNAs, which were integrated as single copy transgenes at the same genomic site in 293T cells. Interestingly, antisense ONs were superior to sense ONs for one target only, showing that target sequence can by itself impart strand-bias in gene editing. The most efficient ONs were short 25 nt ONs with flanking locked nucleic acids (LNAs), a chemistry that had only been tested for targeted nucleotide mutagenesis in yeast, and 25 nt ONs with phosphorothioate linkages. We showed that LNA-modified ONs mediate dose-dependent target modification and analyzed the importance of LNA position and content. Importantly, when using ONs with flanking LNAs, targeted gene modification was stably transmitted during cell division, which allowed reliable cloning of modified cells, a feature essential for further applications in functional genomics and gene therapy. Finally, we showed that ONs with flanking LNAs aimed at correcting the rd1 stop mutation could promote survival of photoreceptors in retinas of rd1 mutant mice, suggesting that they are also active in vivo