Bimetallic salen aluminum complexes: cooperation between reactive centers in the ring-opening polymerization of lactides and epoxides.

Three dinuclear aluminum alkyl complexes of the general formula LAlMe, where L are salen ligands with an alkyl backbone of different lengths between the nitrogen atoms (1,3-propylene (1), 1,5-pentylene (2) and 1,12-dodecaylene (3)), have been prepared through alkane elimination reactions between each ligand and two equivalents of AlMe. The related hemi-salen aluminum complex 4 was prepared by an analogous reaction between a phenoxy-imine ligand and a single equivalent of AlMe. The activities of these aluminum complexes in the ring-opening polymerization (ROP) of rac-lactide and of several epoxides have been investigated and compared.

Male competition fitness landscapes predict both forward and reverse speciation.

Speciation is facilitated when selection generates a rugged fitness landscape such that populations occupy different peaks separated by valleys. Competition for food resources is a strong ecological force that can generate such divergent selection. However, it is unclear whether intrasexual competition over resources that provide mating opportunities can generate rugged fitness landscapes that foster speciation.

Colourful stripes send mixed messages to safe and risky partners in a diffuse cleaning mutualism.

The steps by which neutral, random and/or negative biological interactions evolve into mutualistic ones remain poorly understood. Here, we study Elacatinus gobies and the 'client' fishes they clean. Colourful stripes are common to mutualist cleaners and noncleaning sister species.

Cleaner gobies evolve advertising stripes of higher contrast.

Elacatinus gobies of the Caribbean have undergone rapid speciation along ecological axes, and particular species from this genus act as 'cleaners' that remove ectoparasites from larger coral reef fish, termed 'clients'. Evolutionary shifts in habitat use, behavior and lateral body stripe colors differentiate cleaners from ancestral sponge-dwelling lineages. High-contrast stripe colors associated with cleaning behavior on coral reefs may have evolved as a signal of cleaning status.

Fitness consequences for copepods feeding on a red tide dinoflagellate: deciphering the effects of nutritional value, toxicity, and feeding behavior.

Phytoplankton exhibit a diversity of morphologies, nutritional values, and potential chemical defenses that could affect the feeding and fitness of zooplankton consumers. However, how phytoplankton traits shape plant-herbivore interactions in the marine plankton is not as well understood as for terrestrial or marine macrophytes and their grazers. The occurrence of blooms of marine dinoflagellates such as Karenia brevis suggests that, for uncertain reasons, grazers are unable to capitalize on, or control, this phytoplankton growth-making these systems appealing for testing mechanisms of grazing deterrence.

[Nutrition integrators in sports].

The use or abuse of many preparations, available in the gymnasium or as top-bench drugs, used as nutritive integrators, determines both toxicological and deontological and especially sport medicine problems, because these products are also involved in the antidoping control. Therefore, this article cover the needs for providing a consultation and information manual for all sport operators in the delicate phase of drug-food integration of the athlete, not only to prevent and restrict the doping phenomenon, but also for health-preservation of the athlete.

Incarceration of the gravid uterus.

Retroversion of the first trimester uterus occurs in 6 to 19 per cent of all pregnancies and usually does not cause problems. If the uterus remains retroverted as the pregnancy advances, it may become wedged into the pelvic cavity. This complication is referred to as uterine incarceration which can lead to spontaneous abortion, preterm labor, uterine dystocia, and inadvertent incision into the cervix or the bladder during cesarean section in cases of unrecognized incarceration.

Effect of intravenous magnesium sulfate on the biophysical profile of the healthy preterm fetus.

Objective: The null hypothesis is that intravenous magnesium sulfate does not affect the biophysical profile of the healthy preterm fetus.

Study Design: Thirty-one fetuses of 25 patients between the gestational ages of 24 and 35 weeks, median 31.4 and mean (+/- SD) 30.

Does "idiopathic" preterm labor resulting in preterm birth exist?

Objective: In an effort to elucidate possible causes of preterm labor, we undertook a prospective study of 50 patients consecutively admitted with intact membranes and preterm labor who eventually had a preterm delivery despite the use of tocolysis.

Study Design: A comprehensive evaluation plan was instituted. This included a detailed history and physical examination, targeted ultrasonography, amniocentesis for Gram stain, culture, and glucose determination, laboratory analysis for infection (complete blood cell count, urinalysis, and cervical and urine cultures) and for antiphospholipid antibody syndrome (antinuclear antibody, lupus anticoagulant, anticardiolipin antibody), pathologic examination of the placenta, and a urine toxicology screen.

Ear length in second-trimester aneuploid fetuses.

Objective: To test the hypothesis that small ears have diagnostic value in detecting second-trimester aneuploid fetuses by ultrasound.

Methods: We prospectively studied 452 patients with singleton pregnancies undergoing ultrasound examination for genetic amniocentesis at 14-25 weeks and an additional 30 singleton pregnancies at 20-25 weeks with a negative anomaly screen. Standard fetal biometry measurements were obtained, including ear length (from helix to end of lobe).

Transverse cerebellar diameter measurements in twin pregnancies and the effect of intrauterine growth retardation.

Objectives: Transverse cerebellar diameter measurements have been established for singleton but not twin pregnancies. In singleton pregnancies controversy exists on whether cerebellar growth is affected by intrauterine growth retardation. We undertook this retrospective study in twin pregnancies to establish a nomogram for the transverse cerebellar diameter in twins and to assess the effect of growth retardation on this measurement.

A comparison of pre-discharge survival and morbidity in singleton and twin very low birth weight infants.

The perinatal mortality rate of twins is four to 11 times higher than that of singletons, and twins are widely reported to have more morbidity than singletons, mainly because of a higher preterm birth rate. However, it is not clear that live-born preterm birth rate. However, it is not clear that live-born preterm twins suffer greater morbidity than comparable singletons.

Fatal recurrent reexpansion pulmonary edema.

A case is reported of fatal recurrent unilateral reexpansion pulmonary edema following thoracentesis in a woman with stage IV ovarian adenocarcinoma. Reexpansion pulmonary edema is a rare complication resulting from reexpansion of a collapsed lung after treatment of pleural effusion, pneumothorax, or atelectasis. The etiology is unknown, and there are no guaranteed measures of prevention.