Will the crab Hemigrapsus penicillatus invade the coasts of Europe?

A crab previously unknown in the European fauna was discovered in La Rochelle (France) in 1994. This shore crab was identified as Hemigrapsus penicillatus, a North-West Pacific species. It appears to be spreading rapidly. It has now been detected from Laredo, Spain (43 °25′N, 03 °20′W) to Fromentine, France (46°53′N, 02°09′W) in sheltered areas of the mid-littoral zone. It is locally abundant, with a density of up to 10–20 individuals per square metre. In its native area, its distribution ranges from a cold (northern Japan, south of the Pacific coast of Russia) to a tropical (Taiwan, Hong-Kong) habitat. Being tolerant to both high and low temperatures (even at freezing point), it will probably colonize most of the European and North-African coasts within a short period of time.     

“Primeval forest relict beetles” of Central Europe: a set of 168 umbrella species for the protection of primeval forest remnants

Identification of forest stands with priority for the conservation of biodiversity is of particular importance in landscapes with a long cultural and agricultural history, such as Central Europe. A group of species with a high indicator value for the naturalness of forest ecosystems are saproxylic insects. Some of these species, especially within the order Coleoptera, have been described as primeval forests relicts. Here, we compiled a list of 168 “primeval forest relict species” of saproxylic beetles based on expert knowledge. These species can serve as focal and umbrella species for forest conservation in Central Europe. They were selected because of their dependence on the continuous presence of primeval forest habitat features, such as over-mature trees, high amounts of dead wood, and dead wood diversity, as well as their absence in managed Central European forests. These primeval forest relict species showed a moderately strong clumping pattern within the phylogeny of beetles, as indicated by phylogenetic signal testing using the D-statistic. When we controlled for phylogenetic relatedness, an ordinal linear model revealed that large body size and preference for dead wood and trees of large diameter are the main characteristics of these species. This list of species can be used to identify forest stands of conservation value throughout Central Europe, to prioritize conservation and to raise public awareness for conservation issues related to primeval forests.     

Czech alien flora and the historical pattern of its formation: what came first to Central Europe?

Temporal patterns of immigration to the country were analysed using 668 alien species in the flora of the Czech Republic for which the dates of the first record were available (64.8% of the total number of 1031 so-called neophytes, i.e. aliens introduced after the year 1500). After a period of initial slow increase lasting to the 1840s, the accumulation of neophytes over time could be best fitted by a linear model that explained 97% of the variance. The intensity of floristic research, which varied between periods, did not significantly affect the overall increase in the number of aliens. The effect of species traits on the year of introduction was evaluated, with continent of origin, introduction type (deliberate or accidental), life history, Grime's life strategy, onset of flowering, mode of dispersal and propagule size as explanatory variables. Species of European origin and CSR strategists arrived earlier than those with other origins and strategies. Deliberately introduced species appeared earlier than accidental arrivals, and those cultivated for utilitary reasons on average arrived earlier than ornamentals. Species capable of early flowering were remarkably more prevalent among early newcomers. A separate analysis of accidentally introduced American species also identified life history as a significant predictor of immigration time, with annuals being introduced earlier than biennials and perennials. The data contribute to an understanding of a crucial stage of the invasion process that has received little attention in the literature. The model "early alien" to Central Europe is a European species with a CSR strategy deliberately brought for cultivation as a utilitary plant. Once it escaped from cultivation, its establishment in the wild was favoured by its ability to flower early and, therefore, complete the life cycle.     

Spermatozoa and Plasmodium zoites: the same way to invade oocyte and host cells?

Cell movement or motility is essential for a large variety of processes. Fertilization and host cells invasion by parasites are among the mostly studied models so far. Body of evidences into the literature raises the question that common mechanisms may be found in the sequential events that lead to cell motility in these two particular models. This short review aims at highlighting these common features by comparing knowledge on motile forms of Plasmodium falciparum and one of the best known motile cell namely the spermatozoa. Emphasis will be done on the substantial changes affecting the biochemical, electrophysiological and functional properties of both models.     

Is phylogenetic relatedness to native species important for the establishment of reptiles introduced to California and Florida?

Aim Charles Darwin posited that introduced species with close relatives were less likely to succeed because of fiercer competition resulting from their similarity to residents. There is much debate about the generality of this rule, and recent studies on plant and fish introductions have been inconclusive. Information on phylogenetic relatedness is potentially valuable for explaining invasion outcomes and could form part of screening protocols for minimizing future invasions. We provide the first test of this hypothesis for terrestrial vertebrates using two new molecular phylogenies for native and introduced reptiles for two regions with the best data on introduction histories. Location California and Florida, USA. Methods We performed an ordination of ecological traits to confirm that ecologically similar species are indeed closely related phylogenetically. We then inferred molecular phylogenies for introduced and native reptiles using sequence data for two nuclear and three mitochondrial genes. Using these phylogenies, we computed two distance metrics: the mean phylogenetic distance (MPD) between each introduced species and all native species in each region (which indicates the potential interactions between introduced species and all native species in the community) and the distance of each introduced species to its nearest native relative – NN (indicating the degree of similarity and associated likelihood of competition between each introduced species and its closest evolutionary analogue). These metrics were compared for introduced species that established and those that failed. Results We demonstrate that phylogenetically related species do share similar ecological functions. Furthermore, successfully introduced species are more distantly related to natives (for NN and MPD) than failed species, although variation is high. Main conclusions The evolutionary history of a region has value for explaining and predicting the outcome of human‐driven introductions of reptiles. Phylogenetic metrics are thus useful inputs to multi‐factor risk assessments, which are increasingly required for screening introduced species.     

Disentangling the complexities of vertebrate sex allocation: a role for squamate reptiles?

Sex allocation is an important field in evolutionary biology, both historically and currently. However, while sex allocation theory has successfully predicted sex ratio bias in some taxa, most notably parasitic wasps, vertebrates are notorious for their poor fit to theoretical models. We argue that this arises from the use of very complex model systems to test relatively simple theoretical models. We further argue that squamate reptiles – lizards and snakes – have unduly been neglected in sex allocation studies and in fact may conform more readily to the underlying assumptions of existing theoretical models than many other vertebrates. We provide a five-point argument in favor of the use of squamates as model systems in sex allocation based on their diversity in sex determining mechanisms, life history biology, and ease of experimental manipulations.     

What is the potential for moving adult surgery to the ambulatory setting?

Data from the Manitoba health insurance program were used to analyse the patterns of outpatient surgery in patients aged 20 years or older in the eight largest hospitals in the province (all with at least 125 beds) in 1983-84. With the exception of tooth extraction, only procedures that were not done more than 86% of the time as inpatient or outpatient procedures were considered. Large differences between the hospitals and between physicians within each hospital were found in the rates of outpatient surgery, even after adjustment for patient characteristics and differences in case mix. If the standard of the hospital with the highest rate of outpatient surgery were followed by the seven other hospitals, up to 17.5 inpatient beds could be closed or freed. However, the potential savings from substituting outpatient for inpatient procedures must be realistically appraised. The appropriate place for monitoring the use of inpatient and outpatient surgery may be the individual hospital, particularly those with high occupancy rates and a large demand for inpatient beds.     

Carbohydrates: is the advice to eat less justified for diabetes and cardiovascular health?

PURPOSE OF REVIEW: Recent randomized controlled trials examining diets of varying carbohydrate composition recommended for people with diabetes and cardiovascular disease and those at risk are summarized. RECENT FINDINGS: Severe carbohydrate restriction results in appreciable initial weight loss and improvement in risk factors. After a year, however, the beneficial effects are equal to or less than those achieved on conventional alternatives. Some people develop elevations of LDL cholesterol. Modest carbohydrate restriction with relatively high intakes of cis-unsaturated fatty acids and protein is acceptable to many people and is more likely to produce sustained benefit in terms of weight loss and cardiovascular risk indicators. SUMMARY: Diets involving moderate carbohydrate restriction are suitable alternatives to high-carbohydrate, high-fibre diets for weight loss and reduction of cardiovascular disease and diabetes risk, as well as to treat individuals with the conditions. As such diets are generally high in protein and unsaturated fatty acids, they are not recommended for those with established or incipient nephropathy. High-carbohydrate, high-fibre diets remain appropriate for use in all those situations, provided carbohydrate is derived principally from minimally processed wholegrain breads and cereals and intact vegetables and fruit. Lower carbohydrate options may be preferable for markedly insulin-resistant individuals.     

What is happening to the monocotyledons?

An attempt is made to elucidate some of the more pronounced departures from traditional classifications in the book The families of the monocotyledons byDahlgren and collaborators, which embodies the latest opinions of the lateRolf Dahlgren on the subject. Consideration is given to the treatment of theLiliiflorae (especiallyLiliales andAsparagales) andBromeliiflorae, and to the theory offered for the origin of the monocots which identifies theDioscoreales as the most primitive order of the subclass.Dahlgren aimed at an eclectic classification (one based on a combination of similarity criteria and phylogenetic criteria) and the results of his use of cladistic methods (in association withF. N. Rasumssen) to supply the phylogenetic input are assessed. The resulting system itself is considered in the light of the distinction drawn byJ. S. L. Gilmour between natural and artificial classifications and their respective uses.Dedicated to the memory of JohnS. L. Gilmour.     

Scientific Breeding in Central Europe during the Early Nineteenth Century: Background to Mendel’s Later Work

Efforts to bring science into early 19th century breeding practices in Central Europe, organised from Brno, the Hapsburg city in which Mendel would later turn breeding experiments into a body of timeless theory, are here considered as a significant prelude to the great discovery. During those years prior to Mendel’s arrival in Brno, enlightened breeders were seeking ways to regulate the process of heredity, which they viewed as a force to be controlled. Many were specialising in sheep breeding for the benefit of the local wool industry while others were showing an interest in commercial plants, especially fruit trees and vines, and later cereals. Breeders explained their problems in regulating heredity in terms of (1) climatic influences (2) disruption due to crossing (3) sports or saltations. Practical experience led them to the concepts of ‘inheritance capacity’ and the ‘mutual elective affinity’ of parents. The former was seen to differ among individuals and also among traits; the latter was proposed as a means of adding strength to heredity. The breeders came to recognise that traits might be hidden and yet transmitted as a ‘potential’ to future generations. They also grew to understand that heredity would be strengthened when a quality was ‘fixed’ within a lineage by ‘pure blood relations.’ Continued selection of the desired quality might then lead to ‘a higher perfection.’ But the ultimate ‘physiological’ question about breeding, ‘what is inherited and how?,’ found no answer. Major figures in this development included Abbot Napp, the one who asked this question and who was due to receive Mendel into the monastery in 1843, and Professor Diebl whose lectures on agriculture and natural science at the Brno Philosophical Institute Mendel would attend in 1846. Here we analyse their progress in theorizing about breeding up until about 1840. In discussing this development, we refer to certain international contacts, especially with respect to information transfer and scientific education, within the wider context of the late Enlightenment.     

Visual system: how is the retina wired up to the cortex?

A single retinal output neuron transmits to primary visual cortex through multiple pathways with different strengths. A new study in which activity was simultaneously recorded in pairs of retinal and cortical neurons provides evidence that these pathways converge on a single cortical neuron.     

Area 51: How do Acanthamoeba invade the central nervous system?

Acanthamoeba granulomatous encephalitis generally develops as a result of haematogenous spread, but it is unclear how circulating amoebae enter the central nervous system (CNS) and cause inflammation. At present, the mechanisms which Acanthamoeba use to invade this incredibly well-protected area of the CNS and produce infection are not well understood. In this paper, we propose two key virulence factors: mannose-binding protein and extracellular serine proteases as key players in Acanthamoeba traversal of the blood-brain barrier leading to neuronal injury. Both molecules should provide excellent opportunities as potential targets in the rational development of therapeutic interventions against Acanthamoeba encephalitis.     

Perceptual learning: is V1 up to the task?

Our ability to make fine visual discriminations improves with practice, and so at some level so must our visual system. A new paper reports that the receptive field structure of a neuron can be fine-tuned for different visual tasks. These findings raise important questions about the circuitry and mechanisms that underly perceptual learning.