A large population of 'Lyman-break' galaxies in a protocluster at redshift z approximately 4.1

The most massive galaxies and the richest clusters are believed to have emerged from regions with the largest enhancements of mass density relative to the surrounding space. Distant radio galaxies may pinpoint the locations of the ancestors of rich clusters, because they are massive systems associated with 'overdensities' of galaxies that are bright in the Lyman-alpha line of hydrogen. A powerful technique for detecting high-redshift galaxies is to search for the characteristic 'Lyman break' feature in the galaxy colour, at wavelengths just shortwards of Lyalpha, which is due to absorption of radiation from the galaxy by the intervening intergalactic medium. Here we report multicolour imaging of the most distant candidate protocluster, TN J1338-1942 at a redshift z approximately 4.1. We find a large number of objects with the characteristic colours of galaxies at that redshift, and we show that this excess is concentrated around the targeted dominant radio galaxy. Our data therefore indicate that TN J1338-1942 is indeed the most distant cluster progenitor of a rich local cluster, and that galaxy clusters began forming when the Universe was only ten per cent of its present age.     

Developmental plasticity and human health

Many plants and animals are capable of developing in a variety of ways, forming characteristics that are well adapted to the environments in which they are likely to live. In adverse circumstances, for example, small size and slow metabolism can facilitate survival, whereas larger size and more rapid metabolism have advantages for reproductive success when resources are more abundant. Often these characteristics are induced in early life or are even set by cues to which their parents or grandparents were exposed. Individuals developmentally adapted to one environment may, however, be at risk when exposed to another when they are older. The biological evidence may be relevant to the understanding of human development and susceptibility to disease. As the nutritional state of many human mothers has improved around the world, the characteristics of their offspring--such as body size and metabolism--have also changed. Responsiveness to their mothers' condition before birth may generally prepare individuals so that they are best suited to the environment forecast by cues available in early life. Paradoxically, however, rapid improvements in nutrition and other environmental conditions may have damaging effects on the health of those people whose parents and grandparents lived in impoverished conditions. A fuller understanding of patterns of human plasticity in response to early nutrition and other environmental factors will have implications for the administration of public health.     

The myosin motor in muscle generates a smaller and slower working stroke at higher load

Muscle contraction is driven by the motor protein myosin II, which binds transiently to an actin filament, generates a unitary filament displacement or 'working stroke', then detaches and repeats the cycle. The stroke size has been measured previously using isolated myosin II molecules at low load, with rather variable results, but not at the higher loads that the motor works against during muscle contraction. Here we used a novel X-ray-interference technique to measure the working stroke of myosin II at constant load in an intact muscle cell, preserving the native structure and function of the motor. We show that the stroke is smaller and slower at higher load. The stroke size at low load is likely to be set by a structural limit; at higher loads, the motor detaches from actin before reaching this limit. The load dependence of the myosin II stroke is the primary molecular determinant of the mechanical performance and efficiency of skeletal muscle.     

Mutations in INVS encoding inversin cause nephronophthisis type 2, linking renal cystic disease to the function of primary cilia and left-right axis determination

Nephronophthisis (NPHP), an autosomal recessive cystic kidney disease, leads to chronic renal failure in children. The genes mutated in NPHP1 and NPHP4 have been identified, and a gene locus associated with infantile nephronophthisis (NPHP2) was mapped. The kidney phenotype of NPHP2 combines clinical features of NPHP and polycystic kidney disease (PKD). Here, we identify inversin (INVS) as the gene mutated in NPHP2 with and without situs inversus. We show molecular interaction of inversin with nephrocystin, the product of the gene mutated in NPHP1 and interaction of nephrocystin with beta-tubulin, a main component of primary cilia. We show that nephrocystin, inversin and beta-tubulin colocalize to primary cilia of renal tubular cells. Furthermore, we produce a PKD-like renal cystic phenotype and randomization of heart looping by knockdown of invs expression in zebrafish. The interaction and colocalization in cilia of inversin, nephrocystin and beta-tubulin connect pathogenetic aspects of NPHP to PKD, to primary cilia function and to left-right axis determination.     

Integrative taxonomic revision of Dendrobaena veneta (Rosa, 1886) sensu lato with description of a new species and resurrection of Dendrobaena succinta (Rosa, 1905) (Megadrili: Lumbricidae)

Dendrobaena veneta is one of the most widely used compost worms now distributed all over Europe and has been described under several synonymous names. Besides the typical stripy red specimens, another form bearing pinkish pigmentation also exists, mostly found in natural habitats in the East Mediterranean. Here we provide the first integrative taxonomic analysis of D. veneta, including some closely related species. Both the morphological and molecular results highly support the resurrection of D. succinta, a former synonym of D. veneta. In addition, we describe a peculiar new species, D. karacadagi sp. n. from Anatolia, and prove the highly homoplasious character of the cross section of the longitudinal musculature.

urn:lsid:zoobank.org:pub:336D3F7A-AEA1-465B-9096-03070C761A6A     

Regional,individual and political determinants of FOMC members' key macroeconomic forecasts

We study Federal Open Market Committee members' individual forecasts of inflation and unemployment in the period 1992–2004. Our results imply that Governors and Bank presidents forecast differently, with Governors submitting lower inflation and higher unemployment rate forecasts than bank presidents. For Bank presidents we find a regional bias, with higher district unemployment rates being associated with lower inflation and higher unemployment rate forecasts. Bank presidents' regional bias is more pronounced during the year prior to their elections or for nonvoting bank presidents. Career backgrounds or political affiliations also affect individual forecast behavior.     

Formation of cardiovascular tubes in invertebrates and vertebrates

The cardiovascular system developed early in evolution and is pivotal for the transport of oxygen, nutrients, and waste products within the organism. It is composed of hollow tubular structures and has a high level of complexity in vertebrates. This complexity is, at least in part, due to the endothelial cell lining of vertebrate blood vessels. However, vascular lumen formation by endothelial cells is still controversially discussed. For example, it has been suggested that the lumen mainly forms via coalescence of large intracellular vacuoles generated by pinocytosis. Alternatively, it was proposed that the vascular lumen initiates extracellularly between adjacent apical endothelial cell surfaces. Here we discuss invertebrate and vertebrate cardiovascular lumen formation and highlight the possible modes of blood vessel formation. Finally, we point to the importance of a better understanding of vascular lumen formation for treating human pathologies, including cancer and coronary heart disease.