Julie, ou Le bon père : comédie en trois actes et en prose / par M. D* N**,...

[Représentation. Paris, Théâtre de la Comédie française. 1769-06-14]

Elastic properties and secondary structure formation of single-stranded DNA at monovalent and divalent salt conditions

Single-stranded DNA (ssDNA) plays a major role in several biological processes. It is therefore of fundamental interest to understand how the elastic response and the formation of secondary structures are modulated by the interplay between base pairing and electrostatic interactions. Here we measure force-extension curves (FECs) of ssDNA molecules in optical tweezers set up over two orders of magnitude of monovalent and divalent salt conditions, and obtain its elastic parameters by fitting the FECs to semiflexible models of polymers. For both monovalent and divalent salts, we find that the electrostatic contribution to the persistence length is proportional to the Debye screening length, varying as the inverse of the square root of cation concentration. The intrinsic persistence length is equal to 0.7 nm for both types of salts, and the effectivity of divalent cations in screening electrostatic interactions appears to be 100-fold as compared with monovalent salt, in line with what has been recently reported for single-stranded RNA. Finally, we propose an analysis of the FECs using a model that accounts for the effective thickness of the filament at low salt condition and a simple phenomenological description that quantifies the formation of non-specific secondary structure at low forces.

The effect of positive airway pressure during pre-oxygenation and induction of anaesthesia upon duration of non-hypoxic apnoea

Résumé de l'étude. L'application d'une pression positive (PEEP) pendant la phase d'induction d'une anesthésie générale peut prévenir la formation d'atélectasies pulmonaires. Ceci pourrait permettre d'accroître la durée d'apnée non hypoxique par l'augmentation de la capacité pulmonaire résiduelle fonctionnelle (CRF). Nous avons étudié le bénéfice de l'application d'une PEEP durant la phase d'induction d'une anesthésie générale sur la durée d'apnée avant que la saturation périphérique en oxygène atteigne 90%. Quarante patients ASA I-II ont été randomisés en deux groupes distincts. - Dans le groupe PEEP (n=20), les patients ont été pré-oxygénés durant 5 minutes avec une Fi02 à l00% par l'intermédiaire d'un appareil de CPAP (6cmH2O). Après induction de l'anesthésie, les patients furent ventilés mécaniquement (PEEP 6cmH2O) durant 5 minutes supplémentaires. - Dans le groupe ZEEP (n=20), aucune pression positive (ni CPAP, ni PEEP) ne fut utilisée. La durée d'apnée pour atteindre une saturation périphérique de 90% fut mesurée. La durée d'apnée non hypoxique était plus longue dans le groupe PEEP par rapport au groupe ZEEP (599 +/- 135 s vs 470 +/- 150 s, p= 0,007). Nous concluons que l'application d'une pression positive durant la phase d'induction d'une anesthésie générale chez l'adulte prolonge la durée d'apnée non hypoxique de plus de 2 minutes.

Success rate of airway management by residents in a pre-hospital emergency setting: a retrospective study

Abstract Objective: The objective of this retrospective study over a 5-year period was to assess the success rate of airway management by residents. Criteria of successful airway management were both the adherence to a standardized protocol of pre-hospital airway.

The Effect of Deicing Salt on Aggregate Durability, Progress Report HR-266, 1985

The Iowa DOT has been using rapid freezing in air and thawing in water to evaluate coarse aggregate durability in concrete since 1962. Earlier research had shown that the aggregate pore system was a major factor in susceptibility to D-cracking rapid deterioration. There are cases were service records show rapid deterioration of concrete containing certain aggregates on heavily salted primary roads and relatively good performance with the same aggregate in secondary pavements with limited use of deicing salt. A five-cycle salt treatment of the coarse aggregate prior to durability testing has yielded durability factors that correlate with aggregate service records on heavily salted primary pavements. X-ray fluorescence analyses have shown that sulfur contents correlate well with aggregate durabilities with higher sulfur contents producing poor durability. Trial additives that affect the salt treatment durabilities would indicate that one factor in the rapid deterioration mechanism is an adverse chemical reaction. The objective· of the current research is to develop a simple method of determining aggregate susceptibility to salt related deterioration. This method of evaluation includes analyses of both the pore system and chemical composition.

Pre-stimulus beta oscillations within left posterior sylvian regions impact auditory temporal order judgment accuracy.

Both neural and behavioral responses to stimuli are influenced by the state of the brain immediately preceding their presentation, notably by pre-stimulus oscillatory activity. Using frequency analysis of high-density electroencephalogram coupled with source estimations, the present study investigated the role of pre-stimulus oscillatory activity in auditory spatial temporal order judgments (TOJ). Oscillations within the beta range (i.e. 18-23Hz) were significantly stronger before accurate than inaccurate TOJ trials. Distributed source estimations identified bilateral posterior sylvian regions as the principal contributors to pre-stimulus beta oscillations. Activity within the left posterior sylvian region was significantly stronger before accurate than inaccurate TOJ trials. We discuss our results in terms of a modulation of sensory gating mechanisms mediated by beta activity.

Methods for assessment of pre-harvest sprouting in wheat cultivars

The objective of this work was to test methods for pre-harvest sprouting assessment in wheat cultivars. Fourteen wheat cultivars were grown in Londrina and Ponta Grossa municipalities, Paraná state, Brazil. They were sampled at 10 and 17 days after physiological maturity and evaluated using the methods of germination by rainfall simulation (in a greenhouse), in-ear grain sprouting, and grains removed from the ears. The in-ear grain sprouting method allowed the differentiation of cultivars, but showed different resistance levels from the available description of cultivars. The sprouting of grain removed from the ears did not allow a reliable distinction of data on germination in any harvest date or location. The method of rainfall simulation is the most suitable for the assessment of cultivars as to pre-harvest sprouting, regardless of the sampling date and evaluated location.

Potasssium chloride as a nutrient seed primer to enhance salt‑tolerance in maize

The objective of this work was to determine if KCl could be a useful nutrient primer for safe seed germination in maize crop under salt stress conditions. Seed priming was done using 50 mmol L‑1 of muriate of potash, and germination and seedling growth were evaluated after salt stress with NaCl up to 50 mmol L‑1. Another set of seeds was tested under the same salt stress conditions without priming. Under salinity stress, germination percentage, germination rate index, germination coefficient, and seedling vigor indexes were higher in primed seeds. In unprimed seeds, mean germination time increased, while the germination rate index and the fresh and dry matter mass decreased more sharply with salinity stress. The Na/K ratio was higher in unprimed seeds.