Biogeography of the New Zealand Torrentfish, Cheimarrichthys fosteri (Teleostei: Pinguipedidae): A Distribution Driven Mostly by Ecology and Behaviour

Cheimarrichthys fosteri is an endemic New Zealand freshwater fish that has its closest common ancestry with the blue cod, Parapercis colias, a species found in New Zealand coastal seas. Cheimarrichthys fosteri is amphidromous, and widely distributed around New Zealand. The fact that it has marine-living juvenile has a strong impact on the species' distribution. Upstream/inland penetration in river systems is substantial, and the torrentfish reaches 700m elevation and 289km upstream from the sea. High elevation is typically achieved only at relatively short distances inland, whereas long inland penetration is achieved typically only in low-gradient river systems. The torrentfish is a poor climber, and explicit barriers to upstream migration, such as natural falls and the construction of dams and weirs, limit inland penetration in many river systems. Sparse distribution in some areas, particularly in eastern New Zealand may be due in part to absence or sparseness of riverine gravels. Absence from other areas, such as around Cook and Foveaux straits, the Marlborough Sounds, Fiordland and Stewart and Chatham islands, may result from oceanographic conditions that do not favour return to rivers of the marine-living juveniles. Ecological and behavioural variables relating to the marine life intervals are the predominating factors influencing distribution, and historical biogeographical influences are of minor importance.     

Estimates of gene flow in forest trees

Qualitative and quantitative estimates of gene flow were obtained for fourteen gymnosperm and seven angiosperm forest tree species. High levels of gene flow were prevalent among gymnosperms while these levels varied from high to low among angiosperms. In both groups, species with greater pollen dispersal abilities appear to maintain high levels of gene flow. A detailed analysis of population structure in relation to gene flow was carried out on a gymnosperm species (Pinus rigida) and two angiosperm subspecies (Eucalyptus caesia ssp. caesia and ssp. magna). The results suggested that populations of many species may be concatenated systems bound by gene flow, and the overall levels of gene flow may be influenced by either single or clusters of populations. Different levels of gene flow was found between two closely related species of E. caesia growing under similar ecological conditions, suggesting a plausible link between pollinator behaviour and pollen flow.     

Testing island biogeography theory with visitation rates of birds to British islands

Aim We consider three hypotheses – MacArthur and Wilson’s island biogeography theory (IBT), Lack’s habitat diversity idea and the ‘target effect’– that explain the pattern of decreased species richness on small and distant islands. Location We evaluate these hypotheses using a detailed dataset on the occurrence and abundance of terrestrial birds on nine islands off the coast of Britain and the Republic of Ireland. Methods  Unlike previous studies, we compile data on species that visit the islands, rather than just those that breed on them. We divided the species into five mutually exclusive categories based upon their migratory status and where they regularly breed: British residents, summer visitors to Britain, winter visitors to Britain, and vagrants from Europe or beyond Europe. For each species group on each island we calculated the average number of species visiting each year. We then regressed the average number of species against island area and distance to the mainland (all variables were log‐transformed). We also compared the average number of species visiting each island with the average number of species breeding on each island. Results  Average number of visiting British residents decreased significantly with increasing island distance, but showed no relationship with island area. There was no significant relationship between island area or island distance and average number of summer or winter visitors. European and non‐European vagrants likewise showed no relationship between numbers of species visiting and island distance. However, the relationship between island area and number of visiting species was significant for both these categories; as island area increases so too does the number of visiting species. Main conclusions  As predicted by IBT, there were fewer visiting species on more distant islands. There were substantially more visitors to each island than breeding species, supporting Lack’s argument that lower bird richness is not a result of varying immigration rates (as predicted by IBT) but rather a result of some other island property, e.g. fewer resources. Birds make a decision to either leave an island or stay and breed. The target effect was also clearly demonstrated by the increase in European and non‐European breeders with increasing island size.     

Sticholysin I–membrane interaction: An interplay between the presence of sphingomyelin and membrane fluidity

Sticholysin I (St I) is a pore-forming toxin (PFT) produced by the Caribbean Sea anemone Stichodactyla helianthus belonging to the actinoporin protein family, a unique class of eukaryotic PFT exclusively found in sea anemones. As for actinoporins, it has been proposed that the presence of sphingomyelin (SM) and the coexistence of lipid phases increase binding to the target membrane. However, little is known about the role of membrane structure and dynamics (phase state, fluidity, presence of lipid domains) on actinoporins' activity or which regions of the membrane are the most favorable platforms for protein insertion. To gain insight into the role of SM on the interaction of St I to lipid membranes we studied their binding to monolayers of phosphatidylcholine (PC) and SM in different proportions. Additionally, the effect of acyl chain length and unsaturation, two features related to membrane fluidity, was evaluated on St I binding to monolayers. This study revealed that St I binds and penetrates preferentially and with a faster kinetic to liquid-expanded films with high lateral mobility and moderately enriched in SM. A high content of SM induces a lower lateral diffusion and/or liquid-condensed phases, which hinder St I binding and penetration to the lipid monolayer. Furthermore, the presence of lipid domain borders does not appear as an important factor for St I binding to the lipid monolayer.     

Follow the leader: preference for specific amino acids directly following the initial methionine in proteins of different organisms

It is well established that the vast majority of proteins of all taxonomical groups and species are initiated by an AUG codon, translated into the amino acid methionine (Met). Many attempts were made to evaluate the importance of the sequences surrounding the initiation codon, mostly focusing on the RNA sequence. However, the role and importance of the amino acids following the initiating Met residue were rarely investigated, mostly in bacteria and fungi. Herein, we computationally examined the protein sequences of all major taxonomical groups represented in the Swiss-Prot database, and evaluated the preference of each group to specific amino acids at the positions directly following the initial Met. The results indicate that there is a species-specific preference for the second amino acid of the majority of protein sequences. Interestingly, the preference for a certain amino acid at the second position changes throughout evolution from lysine in prokaryotes, through serine in lower eukaryotes, to alanine in higher plants and animals.     

L’Aurignacien archaïque de la grotte El Castillo (Espagne) : caractérisation technologique et typologique

In this paper, we present the techno-typological study of level 16 of El Castillo cave (Archaic Aurignacian). In this level, we can identify an important bladelet production from schémas opératoires of unipolar prismatic cores, carinated endscraper and carinated burins types. Besides, we find a specific production of Discoid conception. The retouched blanks, though scanty, are dominated by the Dufour bladelets. Level 16 is in relation with the Archaic Aurignacian at the Cantabrian Iberia, which is present in sites like Cueva Morín, Labeko Koba, Gatzarria, or Isturitz and it also is in relation with the Mediterranean Archaic Aurignacian. Finally, we analyse the different hypotheses about the Initial Upper Paleolithic origin in Europe. The mosaic hypothesis is acceptable for us.     

Overexpression of γ-tocopherol methyl transferase gene in transgenic Brassica juncea plants alleviates abiotic stress: Physiological and chlorophyll a fluorescence measurements

Tocopherols (vitamin E) are lipid soluble antioxidants synthesized by plants and some cyanobacteria. We have earlier reported that overexpression of the γ-tocopherol methyl transferase (γ-TMT) gene from Arabidopsis thaliana in transgenic Brassica juncea plants resulted in an over six-fold increase in the level of α-tocopherol, the most active form of all the tocopherols. Tocopherol levels have been shown to increase in response to a variety of abiotic stresses. In the present study on Brassica juncea, we found that salt, heavy metal and osmotic stress induced an increase in the total tocopherol levels. Measurements of seed germination, shoot growth and leaf disc senescence showed that transgenic Brassica juncea plants overexpressing the γ-TMT gene had enhanced tolerance to the induced stresses. Analysis of the chlorophyll a fluorescence rise kinetics, from the initial “O” level to the “P” (the peak) level, showed that there were differential effects of the applied stresses on different sites of the photosynthetic machinery; further, these effects were alleviated in the transgenic (line 16.1) Brassica juncea plants. We show that α-tocopherol plays an important role in the alleviation of stress induced by salt, heavy metal and osmoticum in Brassica juncea.     

Being En Route

Through an ethnography of unauthorized migration from El Salvador to the United States, I explore "clandestinity" as a hidden, yet known, dimension of social reality. Unauthorized migrants who are en route to the United States have to make themselves absent from the spaces they occupy. When they become clandestine, such migrants embody illegality; in some cases, they literally "go underground" should they die and be buried en route. Because their presence is prohibited, unauthorized migrants do not fully arrive even when they reach their destinations. There are parallels between the ways that migrants are present in yet absent from nations, and the ways that ethnographers are present in yet absent from the field. This ethnography of migrants en route therefore suggests how anthropological knowledge practices also produce realities that are hidden, yet known.     

Teleconnection between the early immigration of brown planthopper (Nilaparvata lugens St?l) and ENSO indices: implication for its medium- and long-term forecast

Teleconnection between the early immigration of brown planthopper (BPH) and El Nino/Southern Oscillation (ENSO) indices from January of two years previously to the current June was investigated to make long-term forecast. The teleconnection results were as follows: ENSO indices which were significantly correlated with the early immigration of BPH were primarily sea surface temperature anomalies (SSTA) in N3, N4 and N3.4 regions, accounting for 71.8% of the total. Significant ENSO indices from two years and one year before the immigration events had a proportion of about 84%, while those in the current year only accounted for 16.7%. There was significantly negative correlation between the early immigration of BPH and SSTA in each Nino region from two years before to the previous spring, whereas there was significantly positive correlation between these two factors during the period from the previous winter to the current spring. The significant correlation between the early immigration of BPH and SSTA in each Nino region in the last summer and autumn did not show any obvious tendencies. The relationship between the southern oscillation index (SOI) and the early immigration of BPH was opposite to that between the immigration and SSTA in each Nino region. The above mentioned significant ENSO indices were used as key factors to build forecasting models for the early immigration of BPH by step-wise multiple linear regression analysis. Finally, 12 integrated forecasting models were obtained, which could make predictions 3–27 months ahead and had a predictive accuracy of 88.9%.