Apogon smithi (Kotthaus, 1970) (Teleostei: Apogonidae), a Red Sea cardinalfish colonizing the Mediterranean Sea

Smith's cardinalfish Apogon smithi is recorded for the first time in the Mediterranean Sea. Six specimens were caught by commercial trawler north of Jaffa, Israel, at depths of 40 m and the relatively high number of specimens suggests that A. smithi has established a sustainable population. This is the third Indo-Pacific apogonid species documented in the Mediterranean Sea, and is assumed to be a migrant originating from the Red Sea.     

The costs of reproduction to males and females of a paternal mouthbrooding cardinalfish Apogon notatus

In the cardinalfish Apogon notatus , starving males mouthbrood the eggs, and females are more active than males in courtship and in attacks against conspecific intruders upon their breeding territory, but sexual ornaments are developed in males. Condition factor, hepatosomatic index and fat body-somatic index declined in both sexes during the breeding season. The deterioration of somatic condition was more severe in females, suggesting that the overall energetic costs were larger for females which produced more than twice as many clutches as males brooded in a season. Selective mortality of females could be due primarily to the depletion of their energy reserves. The increased mortality in females is a possible mechanism for the male-biased operational sex ratio which may provide the potential for sexual selection on males.     

Replacement migration,or why everyone is going to have to live in Korea: a fable for our times from the United Nations

This paper considers international migration in the context of population ageing. In many Western countries, the search for appropriate responses to manage future population ageing and population decline has directed attention to international migration. It seems reasonable to believe that international migrants, mostly of young working age, can supply population deficits created by low birth rates, protect European society and economy from the economic costs of elderly dependency, and provide a workforce to care for the elderly. Particular prominence has been given to this option through the publicity attendant on a report from the UN Population Division in 2000 on 'replacement migration', which has been widely reported and widely misunderstood. Although immigration can prevent population decline, it is already well known that it can only prevent population ageing at unprecedented, unsustainable and increasing levels of inflow, which would generate rapid population growth and eventually displace the original population from its majority position. This paper reviews these arguments in the context of the causes and inevitability of population ageing, with examples mostly based on UK data. It discusses various options available in response to population ageing through workforce, productivity, pensions reform and other means. It concludes that there can be no 'solution' to population ageing, which is to a considerable degree unavoidable. However, if the demographic regime of the United Kingdom continues to be relatively benign, future population ageing can be managed with tolerable inconvenience without recourse to increased immigration for 'demographic' purposes. At present (2001), net immigration to the United Kingdom is already running at record levels and is now the main engine behind UK population and household growth. By itself, population stabilization, or even mild reduction, is probably to be welcomed in the United Kingdom, although the issue has attracted little attention since the 1970s.     

Parasitic castration of a vertebrate: Effect of the cymothoid isopod, Anilocra apogonae, on the five-lined cardinalfish, Cheilodipterus quinquelineatus

Parasitic castration, the specific blocking of host reproductive output by an individual parasite, is a host-parasite interaction common to many invertebrates, particularly crustaceans, echinoderms and molluscs. It can reduce host density, alter host population dynamics and the evolution of host life history traits. Here we show that parasitisation by a single female cymothoid isopod, Anilocra apogonae, castrates its vertebrate host, the five-lined cardinalfish, Cheilodipterus quinquelineatus. Parasitised male fish fail to mouthbrood their young. The gonads of parasitised fish are smaller and parasitised female fish have substantially fewer and smaller ova than do the gonads of unparasitised fish. As for parasitic castrators of invertebrate hosts, A. apogonae on C. quinquelineatus are uniformly dispersed amongst infested hosts (one adult female isopod per host), are site specific, and their body size is highly correlated with that of their host. These isopods are large relative to the body size of their hosts, averaging 3.8% of the weight of the host. Parasitised fish also weigh less and are shorter than unparasitised fish of the same age. Despite the presence of other potential hosts, A. apogonae only infests C. quinquelineatus. The consistency of the ecological correlates amongst known parasitic castrators suggests that the parasitic castrator host-parasite relationship will be recognised for other parasites of vertebrates.     

What biogeography is: a place for process

The search for understanding of the past and present processes that have and/or continue to generate observed biotic distribution patterns substantially involves historical reconstruction based on present patterns (both phylogenetic and geographical). How this should be undertaken has been a cause for major debate over many decades. Residual patterns do not always provide explicit pointers to the causal processes, and in addition to applying our understanding of earth history, we need also to carefully explore the implications of contemporary processes as a means for unravelling pattern. Some biogeographers assert that earth and life evolve together, but knowledge of distributions and ecologies indicate that this is sometimes true and sometimes false. Just as general patterns may sometimes indicate a commonality of the means that generated the patterns so, too, do observable processes sometimes indicate commonalities. Vicariance and dispersal are fundamental attributes of biotic distributions. Phylogeography has the potential to assist us in determining which of these mechanisms has generated observable patterns.     

Cell migration: fibroblasts find a new way to get ahead

Fibroblasts migrate on two-dimensional (2D) surfaces by forming lamellipodia-actin-rich extensions at the leading edge of the cell that have been well characterized. In this issue, Petrie et al. (2012. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201201124) show that in some 3D environments, including tissue explants, fibroblasts project different structures, termed lobopodia, at the leading edge. Lobopodia still assemble focal adhesions; however, similar to membrane blebs, they are driven by actomyosin contraction and do not accumulate active Rac, Cdc42, and phosphatidylinositol 3-kinases.     

SABER: a computational method for identifying active sites for new reactions

A software suite, SABER (Selection of Active/Binding sites for Enzyme Redesign), has been developed for the analysis of atomic geometries in protein structures, using a geometric hashing algorithm (Barker and Thornton, Bioinformatics 2003;19:1644–1649). SABER is used to explore the Protein Data Bank (PDB) to locate proteins with a specific 3D arrangement of catalytic groups to identify active sites that might be redesigned to catalyze new reactions. As a proof‐of‐principle test, SABER was used to identify enzymes that have the same catalytic group arrangement present in o‐succinyl benzoate synthase (OSBS). Among the highest‐scoring scaffolds identified by the SABER search for enzymes with the same catalytic group arrangement as OSBS were L ‐Ala D/L ‐Glu epimerase (AEE) and muconate lactonizing enzyme II (MLE), both of which have been redesigned to become effective OSBS catalysts, demonstrated by experiments. Next, we used SABER to search for naturally existing active sites in the PDB with catalytic groups similar to those present in the designed Kemp elimination enzyme KE07. From over 2000 geometric matches to the KE07 active site, SABER identified 23 matches that corresponded to residues from known active sites. The best of these matches, with a 0.28 Å catalytic atom RMSD to KE07, was then redesigned to be compatible with the Kemp elimination using RosettaDesign. We also used SABER to search for potential Kemp eliminases using a theozyme predicted to provide a greater rate acceleration than the active site of KE07, and used Rosetta to create a design based on the proteins identified.     

Correction to: Waste is not a service

The International Journal of Life Cycle Assessment -     

Topological virtual screening: a way to find new anticonvulsant drugs from chemical diversity

A topological virtual screening (tvs) test is presented, which is capable of identifying new drug leaders with anticonvulsant activity. Molecular structures of both anticonvulsant-active and non active compounds, extracted from the Merck Index database, were represented using topological indexes. By means of the application of a linear discriminant analysis to both sets of structures, a topological anticonvulsant model (tam) was obtained, which defines a connectivity function. On the basis of this model, 41 new structures with anticonvulsant activity have been identified by a topological virtual screening.     

A cilium is not a cilium is not a cilium: signaling contributes to ciliary morphological diversity

Mukhopadhyay and colleagues reveal in this issue of Developmental Cell that signaling mediated by a specialized neuronal cilium in C. elegans affects its structure. The finding that this cilium is modified in response to the cues it transduces suggests that cilia may not be static antennae, but organelles whose functions are shaped by their signaling activities.     

The rhizobial adhesion protein RapA1 is involved in adsorption of rhizobia to plant roots but not in nodulation

The effect of the rhizobium adhesion protein RapA1 on Rhizobium leguminosarum bv. trifolii adsorption to Trifolium pratense (red clover) roots was investigated. We altered RapA1 production by cloning its encoding gene under the plac promoter into the stable vector pHC60. After introducing this plasmid in R. leguminosarum bv. trifolii, three to four times more RapA1 was produced, and two to five times higher adsorption to red clover roots was obtained, as compared with results for the empty vector. Enhanced adsorption was also observed on soybean and alfalfa roots, not related to R. leguminosarum cross inoculation groups. Although the presence of 1 mM Ca2+ during rhizobial growth enhanced adsorption, it was unrelated to RapA1 level. Similar effects were obtained when the same plasmid was introduced in Rhizobium etli for its adsorption to bean roots. Although root colonization by the RapA1-overproducing strain was also higher, nodulation was not enhanced. In addition, in vitro biofilm formation was similar to the wild-type both on polar and on hydrophobic surfaces. These results suggest that RapA1 receptors are present in root but not on inert surfaces, and that the function of this protein is related to rhizosphere colonization.     

Finding a place to live: conspecific attraction affects habitat selection in juvenile green and golden bell frogs

Conspecific attraction plays an important role in habitat selection of several taxa and can affect and determine distribution patterns of populations. The behaviour is largely studied and widespread among birds, but in amphibians, its occurrence seems limited to breeding habitats of adults and gregarious tadpoles. The Australian green and golden bell frogs (Litoria aurea) have suffered considerable shrinking of their original distribution in south-eastern Australia since the 1970s. Currently, with only about 40 populations remaining, the species is considered nationally threatened. In natural conditions, these frogs are aggregated in the landscape and do not seem to occupy all suitable ponds within the occurrence area. To date, studies focusing on the frogs’ habitat have failed in finding a general habitat feature that explains current or past occupancy. This led us to the hypothesis that social cues may play a key role in habitat selection in this species. Using two choice experiments, we tested the preference of juvenile green and golden bell frogs for habitats containing cues of conspecifics of similar size versus habitats without conspecific cues. Tested frogs did not show a preference for habitats containing only scent from conspecifics but did prefer habitats where conspecifics were present. Our results show that conspecific attraction is a determining factor in juvenile green and golden bell frog habitat selection. To our knowledge, this is the first time the behaviour is shown to occur in juvenile frogs in the habitat selection context. From a conservation management point of view, the behaviour may help to explain the failure of reintroductions to areas where the frogs have been extinct, and the non-occupation of suitable created habitats in areas where they still inhabit and develop appropriated management strategies.     

Food catches the eye but not for everyone: a BMI-contingent attentional bias in rapid detection of nutriments

An organism's survival depends crucially on its ability to detect and acquire nutriment. Attention circuits interact with cognitive and motivational systems to facilitate detection of salient sensory events in the environment. Here we show that the human attentional system is tuned to detect food targets among nonfood items. In two visual search experiments participants searched for discrepant food targets embedded in an array of nonfood distracters or vice versa. Detection times were faster when targets were food rather than nonfood items, and the detection advantage for food items showed a significant negative correlation with Body Mass Index (BMI). Also, eye tracking during searching within arrays of visually homogenous food and nonfood targets demonstrated that the BMI-contingent attentional bias was due to rapid capturing of the eyes by food items in individuals with low BMI. However, BMI was not associated with decision times after the discrepant food item was fixated. The results suggest that visual attention is biased towards foods, and that individual differences in energy consumption--as indexed by BMI--are associated with differential attentional effects related to foods. We speculate that such differences may constitute an important risk factor for gaining weight.     

Attenuated Mengo virus: a new vector for live recombinant vaccines.

Several features make Mengo virus an excellent candidate for use as a vaccine vector. The virus has a wide host range, including rodents, pigs, monkeys, and most likely humans, and expresses its genome exclusively in the cytoplasm of the infected cell. Stable attenuated strains exist which are deleted for part of the 5' noncoding region of the genome. Here we report an attenuated Mengo virus recombinant, vLCMG4, that encodes an immunodominant cytotoxic T-lymphocyte epitope of the lymphocytic choriomeningitis virus (LCMV) nucleo-protein. vLCMG4 induced protective immunity against lethal LCMV infection after a single, low-dose immunization in BALB/c mice and elicited an LCMV-specific CD8+ cytotoxic T lymphocyte response. This demonstrates the potential of recombinant Mengo virus vaccines to confer protection against infectious diseases by the induction of cellular immune responses.     

Oxytocin receptor is not required for social attachment in prairie voles

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