On the redshift distribution and physical properties of ACT-selected DSFGs.

We present multi-wavelength detections of nine candidate gravitationally-lensed dusty star-forming galaxies (DSFGs) selected at 218GHz (1.4mm) from the ACT equatorial survey. Among the brightest ACT sources, these represent the subset of the total ACT sample lying in Herschel SPIRE fields, and all nine of the 218GHz detections were found to have bright Herschel counterparts. By fitting their spectral energy distributions (SEDs) with a modified blackbody model with power-law temperature distribution, we find the sample has a median redshift of z = 4.1 - 1.0 + 1.1 (68 per cent confidence interval), as expected for 218GHz selection, and an apparent total infrared luminosity of log 10 ( µ L IR / L ⊙ ) = 13.86 - 0.30 + 0.33 , which suggests that they are either strongly lensed sources or unresolved collections of unlensed DSFGs. The effective apparent diameter of the sample is µ d = 4.2 - 1.0 + 1.7 kpc , further evidence of strong lensing or multiplicity, since the typical diameter of dusty star-forming galaxies is 1.0-2.5 kpc. We emphasize that the effective apparent diameter derives from SED modelling without the assumption of optically thin dust (as opposed to image morphology). We find that the sources have substantial optical depth. ( τ = 4.2 - 1.9 + 3.7 ) to dust around the peak in the modified blackbody spectrum (λ obs ⩽ 500µm), a result that is robust to model choice.

The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3.

Stellar archaeology shows that massive elliptical galaxies formed rapidly about ten billion years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies at redshifts z greater than 2. Although the mean molecular gas mass (5 × 10(10) solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies that already have stellar masses above 2 × 10(11) solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 10(11) solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.

The detection of a population of submillimeter-bright, strongly lensed galaxies.

Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty star-forming galaxies. However, the identification of gravitational lenses is often time-intensive, involving the sifting of large volumes of imaging or spectroscopic data to find few candidates. We used early data from the Herschel Astrophysical Terahertz Large Area Survey to demonstrate that wide-area submillimeter surveys can simply and easily detect strong gravitational lensing events, with close to 100% efficiency.

Quasianamorphic optical imaging system with tomographic reconstruction for electron beam imaging.

We have developed a quasianamorphic optical tomography system coupled to a streak camera to provide continuous recording of the electron beam profile of an intense, long-pulse induction accelerator. A tomographic reconstruction method based on a maximum-entropy algorithm is used to reconstruct the images. The system has simplified the calculation of beam moments, eliminated ambiguity due to beam motion, and contributed to accelerator tuning.

Pygmoid Australomelanesian Homo sapiens skeletal remains from Liang Bua, Flores: population affinities and pathological abnormalities.

Liang Bua 1 (LB1) exhibits marked craniofacial and postcranial asymmetries and other indicators of abnormal growth and development. Anomalies aside, 140 cranial features place LB1 within modern human ranges of variation, resembling Australomelanesian populations. Mandibular and dental features of LB1 and LB6/1 either show no substantial deviation from modern Homo sapiens or share features (receding chins and rotated premolars) with Rampasasa pygmies now living near Liang Bua Cave. We propose that LB1 is drawn from an earlier pygmy H. sapiens population but individually shows signs of a developmental abnormality, including microcephaly. Additional mandibular and postcranial remains from the site share small body size but not microcephaly.

Palaeontology: early Neolithic tradition of dentistry.

Prehistoric evidence for the drilling of human teeth in vivo has so far been limited to isolated cases from less than six millennia ago. Here we describe eleven drilled molar crowns from nine adults discovered in a Neolithic graveyard in Pakistan that dates from 7,500-9,000 years ago. These findings provide evidence for a long tradition of a type of proto-dentistry in an early farming culture.

Roller organotypic cultures of postnatal rat retina.

Floating retinal sections from 7-12-day-old rats form ball-shaped retinal bodies during roller culturing. Histological studies of serial sections of retinal bodies showed that their outer surface is formed by the retina completely retaining organotypic cytoarchitectonics. Some retinal bodies have laminar structure consisting of several layers of the retina. At the initial stages of culturing some retinal bodies contain a cavity, which later is completely obliterated due to the growth of axons of ganglion cells and migration of glial cells and fibroblasts. This study demonstrated the possibility of long-term survival, differentiation, and in vitro axonal regeneration of ganglion cells, the main retinal efferent neurons, which can provide the basis for investigation of pathology and drug correction of injuries and stimulation of regeneration of these cells in experimental glaucoma models.

Modern human ancestry at the peripheries: a test of the replacement theory.

The replacement theory of modern human origins stipulates that populations outside of Africa were replaced by a new African species of modern humans. Here we test the replacement theory in two peripheral areas far from Africa by examining the ancestry of early modern Australians and Central Europeans. Analysis of pairwise differences was used to determine if dual ancestry in local archaic populations and earlier modern populations from the Levant and/or Africa could be rejected. The data imply that both have a dual ancestry. The diversity of recent humans cannot result exclusively from a single Late Pleistocene dispersal.

Integrated optical biosensor for detection of multivalent proteins.

We have developed a simple, highly sensitive and specific optical waveguide sensor for the detection of multivalent proteins. The optical biosensor is based on optically tagged glycolipid receptors embedded within a fluid phospholipid bilayer membrane formed upon the surface of a planar optical waveguide. Binding of multivalent cholera toxin triggers a fluorescence resonance energy transfer that results in a two-color optical change that is monitored by measurement of emitted luminescence above the waveguide surface. The sensor approach is highly sensitive and specific and requires no additional reagents and washing steps. Demonstration of protein-receptor recognition by use of planar optical waveguides provides a path forward for the development of fieldable miniaturized biosensor arrays.

Evaluation of thoracic aortic disease with the use of helical CT and multiplanar reconstructions: comparison with surgical findings.

PURPOSE: To assess the accuracy of helical computed tomography (CT) in differentiating different types of thoracic aortic disease, to determine the incremental value of multiplanar reconstructions, and to determine if helical CT could help to reliably predict the need for intraoperative hypothermic circulatory arrest. MATERIALS AND METHODS: Forty-nine patients underwent pre-operative helical CT with multiplanar reconstructions. Images were reviewed for type and location of pathologic lesions and for features that indicated the need for hypothermic circulatory arrest. The incremental yield of multiplanar reconstructions compared with that of axial images was assessed. Imaging findings were compared with surgical findings. RESULTS: The types of lesions present in the patients included 36 aneurysms (three were ruptured), six penetrating ulcers, five dissections, and two pseudoaneurysms. The accuracy of diagnosis was 92% (45 of 49 patients) with the use of CT (both with and without multiplanar reconstruction). The necessity of hypothermic circulatory arrest was successfully predicted in 94% (45 of 48 patients) of cases. CONCLUSION: Helical CT, both with and without the use of multiplanar reconstruction, enabled highly accurate differentiation among diseases of the thoracic aorta and prediction of the need for hypothermic circulatory arrest.

Ohalo II H2: a 19,000-year-old skeleton from a water-logged site at the Sea of Galilee, Israel.

The discovery of well-preserved human remains at the site of Ohalo II in the northern Jordan Valley substantially augments the meager fossil record of the Levantine late Upper Pleistocene. The Ohalo II H2 specimen, dated to ca. 19,000 B.P., is the most complete early Epipaleolithic hominid discovered in Israel and promises to contribute to the clarification of a number of problematic issues in the local evolution of anatomically modern humans. In addition to a description of the burial and its Kebaran context, a detailed anatomical description of the skeleton is offered and morphometric comparisons are made to other Upper Paleolithic hominids. Ohalo II H2 is shown to demonstrate affinities in the craniofacial skeleton to fossils from the early Upper Paleolithic and late Epi-Paleolithic of the Levant.

On the etiology of interproximal grooves.

The recent suggestion by Brown and Molnar (1990) that the common etiology of sinew processing is responsible for the production of interproximal tooth grooves is contested. Based on a review of the Australian evidence and presentation of a previously undescribed dentition from Central Europe, it is argued toothpicks are a likely cause of many artificial grooves in human teeth.

Bilateral absence of the lesser trochanter in a late Epigravettian skeleton from Arene Candide (Italy).

A virtually complete skeleton recovered from excavations in a Late Upper Paleolithic context by Cardini between 1940 and 1942 at the Arene Candide cave (NW Italy) lacks the normal development of the left and right lesser trochanters. The specimen is a short-statured male about 25 years old and shows no other especially peculiar skeletal irregularities, except for high negative angles of femoral torsion. We discuss a number of possible etiologies for the anomalous absence of the lesser trochanters. The condition is most likely a result of an epigenetic effect or a traumatic avulsion of both lesser trochanters. If the absence of normal development of the lesser trochanters involves a congenital condition, it is an extremely rare, previously undescribed trait. If the condition results from bilateral traumatic avulsion, it is probably the result of excessive muscular stress on the proximal femur and provides further evidence of hardship of life in Paleolithic populations and of the ability of these people to survive debilitating trauma.

A case of chondrodystrophic dwarfism in the Italian late Upper Paleolithic.

During excavations by P. Graziosi at Romito Cave near Papasidero (Cosenza) in Calabria, Italy, two skeletons (Romito 1 and 2) were discovered in a common grave. Although the specimens were briefly described by Messeri (Atti X Riuniuone Scientifica Ist. Ital. Preist. Protost., pp. 301-307, 1966), it is generally unknown in the anthropological literature that one of these individuals is a chondrodystrophic dwarf. As such, the specimen provides the earliest known case of dwarfism in the human skeletal record, extending the time span of this genetically determined growth abnormality to approximately 10,000 years ago. The specimen (Romito 2) exhibits features typical of chondrodysplasia, including a high domed skull, compressed cranial base, and in the postcranial skeleton extremely shortened diaphyseal lengths. The unique combination of these features suggests this pathological condition is acromesomelic dysplasia. Besides providing evidence for a greater antiquity of dwarfism than previously known, the fact that this individual reached late adolescence attests to tolerance of Upper Paleolithic groups for severely abnormal individuals and their ability to support members who were of limited economic value to the social group.

Dwarfism in an adolescent from the Italian late Upper Palaeolithic.

There have been numerous reports of pathological conditions in the hominid fossils, but these have only involved trauma or age-related deterioration in the health of otherwise normal individuals. Here we describe a skeleton of a young male from Riparo del Romito in Calabria, dated to the Epi-Gravettian of southern Italy. The preserved skeletal elements show that this individual (Romito 2) had the skull and long-bone morphology consistent with a mesomelic form of dwarfism, most probably the autosomal recessive disorder acromesomelic dysplasia. Generally recognized at birth, persons with acromesomelic dysplasia usually have normal intelligence and are free of serious medical problems. However, growth deficiency is severe (adult height typically is 110-120 cm) and mobility at the elbows is restricted. These physical impairments would have greatly interfered with the individual's participation in subsistence activities and would have been a substantial handicap in a nomadic hunting and gathering group. Thus, besides being the earliest known case of dwarfism in the human record, this skeleton provides evidence of tolerance of, and care for, a severely deformed individual in the Palaeolithic.

Artificial grooves on the Krapina Neanderthal teeth.

Gross and microscopic examination of the Krapina Neanderthal dental remains reveals the presence of artificial grooves along the cemento-enamel junction of 14 teeth representing ten different individuals. The grooves display distinct morphological features including their consistent location (primarily on the mesial and/or distal root walls), their troughlike appearance, striations and/or polishing in the channel, and the ridges of reactive cementum bordering the groove. These grooves occur only on erupted, permanent teeth, and except for a single occurrence on a lower I2, all are located on mandibular or maxillary P4-M3. The morphological nature of the grooves is distinct and has been used to distinguish these grooves from root caries and other pathological or natural causes. Based on the close resemblance between artificial grooves at Krapina and those which have been attributed to toothpick use in other fossil and recent populations, we argue the Krapina Neanderthals were habitually probing the interproximal dental spaces with tools.