Delineation of a recognisable phenotype of interstitial deletion 3 (q22.3q25.1) in a case with previously unreported truncus arteriosus

Interstitial deletions of chromosome 3q22.3e25.1 are very rare with only five previous reports of deletions in this region [1,2,4,7,9]. We describe a case of a female infant with a de novo deletion. Dysmorphic features and congenital heart disease led to a clinical genetics assessment on day 1 of life. Chromosomal analysis showed an interstitial deletion with a female karyotype 46,XX,del (3)(q23q25.1) dn. Subsequent array CGH demonstrated the breakpoints as 3q22.3q25.1. This is the first documented association with a truncus arteriosus. We identify an emerging clinical phenotype of microphthalmia, microcephaly, congenital heart disease, slow feeding, skeletal abnormalities, with an abnormal facies and developmental delay. Array CGH demonstrated that the FOXL2 gene responsible for BPES was not deleted in this patient. (C) 2010 Elsevier Masson SAS. All rights reserved.

Artificial Impedance Surfaces for Reduced Dispersion in Antenna Feeding Systems

An impedance surface is presented that reduces the dispersion experienced upon propagation of broadband pulses within rectangular waveguides. The surface impedance is selected so that, within a frequency range, the transverse resonance condition is satisfied for longitudinal wavenumber that varies linearly with frequency. A synthesis procedure for practical surface topologies consisting of periodic dipole arrays is described. An example involving a finite structure is employed to illustrate the reduced dispersion. Numerical simulation results obtained from in-house mode-matching method as well as HFSS are presented. A prototype is fabricated and tested experimentally validating the theoretical predictions.

Feeding and digestive strategies in deposit-feeding holothurians

Deposit-feeding holothurians employ a range of feeding and digestive strategies depending on the Particular environment to which they are adapted. Habitat and feeding specialisation is reflected in the tentacles, which show high diversity.

Tentacular diversity in deep-sea deposit-feeding holothurians: implications for biodiversity in the deep sea

The tentacles of deep-sea holothurians show a wide range of morphological diversity. The present paper examines gross tentacle morphology in surface deposit feeding holothurians from a range of bathymetric depths. Species studied included the elasipods: Oneirophanta mutabilis, Psychropotes longicauda and Benthogone rosea and the aspidochirotids: Paroriza prouhoi, Pseudostichopus sp., Bathyplotes natans and Paroriza pallens. The sympatric abyssal species Oneirophanta mutabilis, Psychropotes longicauda and Pseudostichopus sp. show subtle differences in diet and the structure and filling patterns of the gut that suggest differences in feeding strategies which may represent one mechanism to overcome competition for food resources in an environment where nutrient resources are considered to be, at least periodically, limiting. Interspecific differences in tentacle functional morphology and digestive strategies, which reflects taxonomic diversity could be explained in terms of Sanders'; Stability–Time Hypothesis. Since different tentacle types will turn over sediments to different extents, their impact on sedimentary communities will be enormous so that high diversity in meiofaunal communities may be explained most simply by Dayton and Hessler's Biological Disturbance Hypothesis.

Further observations on tentacular feeding mechanisms in holothurians

Resource partitioning by aspidochirote holothurians from Beacon Island, Western Australia is largely on the basis of distinct macro- and micro-habitat preferences. Where two or more species occur together or overlap, food partitioning may be by using distinct feeding techniques (Holothuria cinerascens (Brandt), H. impatiens (Forskal) and H. difficilis Semper) or by particle selectivity (H. cf. pervicax Selenka and H. hartmeyeri Erwe). Methods of particle handling by the majority of species studied are similar, involving the use of tentacular nodules on sediment deposits but H. cinerascens collects particles from suspension in a dendrochirote-like tentacle. The nature and rôle of surface secretions are considered for both types of tentacles and the taxonomic value of tentacle form in the Holothurioidea questioned.