Parental age and reproduction in the Marsh Tit Paras palustris

In the Marsh Tit Parus palustris , breeding performance improved with the age of both the male and the female parent—older birds produced larger clutches earlier in the season. The effect of male age, however, was mainly due to a positive association with the age of the female. When the effect of laying date was accounted for, there was no additional effect of female age on clutch-size. However, pairs with previous breeding experience laid larger clutches than newly formed pairs of the same age. There was some evidence that young females that laid late in the season were less likely to survive to breed again, leading to an age effect on reproductive performance. There was no evidence that individual birds laid earlier or produced larger clutches when they became older.     

CO2 fertilization in temperate FACE experiments not representative of boreal and tropical forests

Results from free-air CO₂ enrichment (FACE) experiments in temperate climates indicate that the response of forest net primary productivity (NPP) to elevated CO₂ might be highly conserved across a broad range of productivities. In this study, we show that the LPJ-GUESS dynamic vegetation model reproduces the magnitude of the NPP enhancement at temperate forest FACE experiments. A global application of the model suggests that the response found in the experiments might also be representative of the average response of forests globally. However, the predicted NPP enhancement in tropical forests is more than twice as high as in boreal forests, suggesting that currently available FACE results are not applicable to these ecosystems. The modeled geographic pattern is to a large extent driven by the temperature dependence of the relative affinities of the primary assimilation enzyme (Rubisco) for CO₂ and O₂.     

Regulation of the Cytoplasmic pH of Chara corallina in the Absence of External Ca2+: Its Significance in Relation to the Activity and Control of the H+ Pump

Effects of removal of external Ca²⁺ on the cytoplasmic pH (pH_c)of Chara corallina have been measured with the weak acid 5,5-dimethyl-oxazolidine-2,4-dione(DMO) as a function of external pH (pH₀) and of the externalconcentration of K⁺. Removal of Ca²⁺ always decreased pH_c whenpH₀ was below about 6.0; the decrease was about 0.2–0.4units at pH₀ 5.0, increasing to about 0.5 units at pH₀ 4.3.When pH₀ was 6.0 or higher the removal of Ca²⁺ had little orno effect on pH_c. This situation was not altered by changingthe concentration of K⁺, though in some experiments at pH₀ 5.0–5.2there was a slight decrease in pH₀ (about 0.2 units) when K⁺was increased from 0.2 to 2.0 mol m^–3, an effect apparentlyreversed when K⁺ was higher (5.0 or 10.0 mol m^–3). Theresults suggest that H⁺ transport continues in the absence ofexternal Ca²⁺, despite previous suggestions to the contrary,and that the H⁺ pump does not necessarily run near thermodynamicequilibrium with its chemical driving reaction. They indicate,rather, that the H⁺ pump is under kinetic control and providefurther evidence for the inadequacy of present models for theoperation of the H⁺ pump in charophyte cells, especially inrelation to its proposed role in regulating pH_c. Key words: Chara corallina, Cytoplasmic pH, Calcium     

The long‐term history of dispersal among lizards in the early Eocene: new evidence from a microvertebrate assemblage in the Bighorn Basin of Wyoming,USA

Abstract: Early Eocene mammal faunas of North America were transformed by intercontinental dispersal at the Paleocene–Eocene boundary, but lizard faunas from the earliest Eocene of the same area were dominated by immigrants from within the continent. A new lizard assemblage from the middle early Eocene of Wyoming sheds light on the longer‐term history of dispersal in relation to climate change. The assemblage consists of three iguanid species (including two new species possibly closely related to living Anolis), Scincoideus, ‘Palaeoxantusia’, four anguids, two species of an undescribed new anguimorph clade, Provaranosaurus and a varanoid (cf. Saniwa). Most North American glyptosaurin glyptosaurines are now referred to Glyptosaurus, and Glyptosaurus hillsi is given a new diagnosis. Scincoideus is otherwise known only from the mid‐Paleocene of Belgium, and the specimens described here are the first to document intercontinental dispersal to North America among lizards in the early Eocene. Like in mammals, some immigrant lizard lineages first appearing in the Bighorn Basin in the earliest Eocene persisted in the area long after the Paleocene–Eocene thermal maximum, but other immigrants appear to have been restricted to the Paleocene–Eocene thermal maximum.     

Tongues, tentacles and trunks: the biomechanics of movement in muscular-hydrostats

Muscular-hydrostats, muscular organs which lack typical systems of skeletal support, include the tongues of mammals and lizards, the arms and tentacles of cephalopod molluscs and the trunks of elephants. In this paper the means by which such organs produce elongation, shortening, bending and torsion are discussed. The most important biomechanical feature of muscular-hydrostats is that their volume is constant, so that any decrease in one dimension will cause a compensatory increase in at least one other dimension. Elongation of a muscular-hydrostat is produced by contraction of transverse, circular or radial muscles which decrease the cross-section. Shortening is produced by contraction of longitudinal muscles. The relation between length and width of a constant volume structure allows amplification of muscle force or displacement in muscular-hydrostats and other hydrostatic systems. Bending requires simultaneous contraction of longitudinal and antagonistic circular, transverse or radial muscles. In bending, one muscle mass acts as an effector of movement while the alternate muscle mass provides support for that movement. Torsion is produced by contraction of muscles which wrap the muscular-hydrostat in a helical fashion.     

Bank voles in linear habitats show restricted gene flow as revealed by mitochondrial DNA (mtDNA)

Genetic structure of bank vole populations in linear river bank habitat in southeast Norway was determined from analyses of DNA sequences for the mitochondrial D-loop. Animals were sampled at sites separated by 1 km, along two forested river banks separated by ≈ 100 m of open water. Twenty-six distinct haplotypes were found among 120 voles. The voles showed significant deviation from panmixis on both sides of the river. Animals from the same site or from sites 1 km apart were more likely to share haplotypes than animals 2 km apart or more. Common haplotypes were widespread on both river banks, and had a wider distribution than relatively rare haplotypes. Some rare haplotypes were found on both banks, but most were restricted to a single bank. The results suggest that short-term gene flow may be restricted for female bank voles in linear habitats. Female territorial behaviour may vary with habitat geometry. In the linear habitat described here, females defend only two territorial borders and may effectively limit female dispersal. Results were compared to a previous study of bank voles from this region in a two-dimensional habitat. Gene flow in the linear habitat was much more restricted than gene flow in the two-dimensional habitat. Probable mechanisms underlying this difference are discussed.     

SIMPLE: implementation of recommendations from international evidence-based guidelines on caesarean sections in the Netherlands. Protocol for a controlled before and after study

Background

Caesarean section (CS) rates are rising worldwide. In the Netherlands, the most significant rise is observed in healthy women with a singleton in vertex position between 37 and 42 weeks gestation, whereas it is doubtful whether an improved outcome for the mother or her child was obtained. It can be hypothesized that evidence-based guidelines on CS are not implemented sufficiently. Therefore, the present study has the following objectives: to develop quality indicators on the decision to perform a CS based on key recommendations from national and international guidelines; to use the quality indicators in order to gain insight into actual adherence of Dutch gynaecologists to guideline recommendations on the performance of a CS; to explore barriers and facilitators that have a direct effect on guideline application regarding CS; and to develop, execute, and evaluate a strategy in order to reduce the CS incidence for a similar neonatal outcome (based on the information gathered in the second and third objectives).

Methods

An independent expert panel of Dutch gynaecologists and midwives will develop a set of quality indicators on the decision to perform a CS. These indicators will be used to measure current care in 20 hospitals with a population of 1,000 women who delivered by CS, and a random selection of 1,000 women who delivered vaginally in the same period. Furthermore, by interviewing healthcare professionals and patients, the barriers and facilitators that may influence the decision to perform a CS will be measured. Based on the results, a tailor-made implementation strategy will be developed and tested in a controlled before-and-after study in 12 hospitals (six intervention, six control hospitals) with regard to effectiveness, experiences, and costs.

Discussion

This study will offer insight into the current CS care and into the hindering and facilitating factors influencing obstetrical policy on CS. Furthermore, it will allow definition of patient categories or situations in which a tailor-made implementation strategy will most likely be meaningful and cost effective, without negatively affecting the outcome for mother and child.

Trial registration

http://www.clinicaltrials.gov: NCT01261676