Molecular Systematic of Three Species of Oithona (Copepoda, Cyclopoida) from the Atlantic Ocean: Comparative Analysis Using 28S rDNA

Species of Oithona (Copepoda, Cyclopoida) are highly abundant, ecologically important, and widely distributed throughout the world oceans. Although there are valid and detailed descriptions of the species, routine species identifications remain challenging due to their small size, subtle morphological diagnostic traits, and the description of geographic forms or varieties. This study examined three species of Oithona (O. similis, O. atlantica and O. nana) occurring in the Argentine sector of the South Atlantic Ocean based on DNA sequence variation of a 575 base-pair region of 28S rDNA, with comparative analysis of these species from other North and South Atlantic regions. DNA sequence variation clearly resolved and discriminated the species, and revealed low levels of intraspecific variation among North and South Atlantic populations of each species. The 28S rDNA region was thus shown to provide an accurate and reliable means of identifying the species throughout the sampled domain. Analysis of 28S rDNA variation for additional species collected throughout the global ocean will be useful to accurately characterize biogeographical distributions of the species and to examine phylogenetic relationships among them

Influence of dielectric breakdown on MOSFET drain current

Breakdown of gate dielectric is one of the most dangerous threats for reliability of MOSFET devices in operating conditions. Not only the gate leakage resulting from breakdown is a problem for power consumption issues, but the "on" drain current can be strongly affected. In this paper, we show that in recent technologies, featuring ultrathin gate dielectrics, the corruption of drain current due to breakdown can be modeled as the effect of a portion of channel being damaged by the opening of the breakdown spot. Devices featuring 2.2- and 3.5-nm-thick gate oxide and various channel widths are stressed by using a specialized setup, and the degradation of transistor parameters is statistically studied. The analysis shows that the radius of the damaged region responsible for drain current degradation can be estimated between 1.4 and 1.8 /spl mu/m

One-stage breast reconstruction techniques in elderly patients to preserve quality of life

The aim of this study was to review one-stage breast reconstruction techniques performed in elderly patients at our institution to identify the criteria of selection of each in terms of outcomes and quality of life

Prospective study on Trilucent soybean oil-filled breast prosthesis

Background: The use of Trilucent breast implants dates back to 1995. These implants were produced in an attempt to overcome the perceived shortcomings of other implants filled with saline and silicone gel. The filler material, which was derived from soybean oil, was said to be biodegradable and biocompatible. When this prosthesis was subsequently found to be prone to rapid aging and rupture of the silicone shell, the company that manufactured this implant decided to withdraw it from the market and offered to remove or replace all Trilucent prostheses. Methods: The authors present a clinical study of the Trilucent implant in which 36 patients received a total of 63 implants and 33 patients had 58 implants removed. The authors also examined the implant shell of the removed prostheses to investigate the possible cause of silicone implant aging and rupture. Results: Each of the implants removed was carefully inspected visually, and samples of the implant shell were analyzed by scanning electron microscopy. All the implants removed had a very bizarre appearance; they were variegated in color, with shades of yellow and brown, and were studded with whitish yellow nodules whose number grew in proportion to the time the prosthesis was implanted. Scanning electron microscopic analysis of the implant shell revealed a heterogeneous inner surface of the implant together with fissures and globoid deposits on the cut surface. Conclusions: The authors' findings on Trilucent implants are similar to those reported in previously published studies for other types of breast implants for the first 2 years after implantation, after which a progressive, rapid deterioration was observed

Neritization of the plankton fauna in the Mediterranean basin

The plankton fauna neritization in the Mediterranean Seas basin is discussed. Neritization is an increase of the neritic species percentage in zooplankton composition from the Mediterranean to the Black and Sea of Azov; It has been shown that the percentage of oceanic species decreases considerably in the Mediterranean Sea, adjacent to Gibraltar strait if compared with the Atlantic region, and the share of neritic – oceanic and neritic species increases correspondingly. Some of these species were observed in the open sea. In the Black Sea, oceanic species are absent. Neritic – oceanic and neritic species, which came there from the Mediterranean Sea, are distributed through out the area. The shallow-water straits between the seas and considerable changes in salinity and temperature regime prevent penetration of oceanic and neritic – oceanic species into each following sea of the Mediterranean basin. Considerable decrease of each sea, increase of the shelf percentage, decrease in the system stability of the circulating currents, separating coastal waters, and these of central regions, facilitate spatial distribution of alien species all over with masses of the seas. The high abundance of neritic species in the Black and Sea of Azov central regions can be possibly explained by a decrease in number of competitors for food and predators (before introduction of Ctenophora Mnemiopsis leidyi A. Agassiz, 1865) and an increase in food concentration for zooplankton

Scalp Reconstruction using Dermal Induction Template: State of the Art and Personal Experience.

The loss of skin envelope is a frequent and costly problem in health care. This article provides an overview on the state of the art in scalp reconstruction with dermal substitutes, as well as our personal experience of ten critical patients with non-melanoma skin cancer of the scalp. These patients were treated in a two-stage procedure by wide tumor excision, apposition of a dermal induction template (Hyalomatrix (R)) and successive skin grafting. Four patients underwent subgaleal tumor excision with preservation of the periosteum and six patients en bloc tumor excision together with the external cortical bone. A 10x10 cm template was used in all patients. Two weeks after demolition surgery, we observed neodermis formation. Results were documented by comparative photography, visual analogue scale for patient satisfaction, and Vancouver scar scale for evaluation of final graft characteristics. Patients were tumor-free during follow-up. The procedure achieved good scalp reshaping and graft scarring evolution. Patient satisfaction was high. Hyalomatrix (R) was effective for oncological scalp reconstruction in critical patients. It prepared the wound bed for graft take while awaiting histological diagnosis and confirmation of margin clearance. Further studies on dermal substitutes are needed to improve benefit in patients

Zooplankton associations in a Mediterranean long-term time-series

Coastal zooplankton have been investigated since 1984 at a Long Term Ecological Research station MC (LTER-MC) in the inner Gulf of Naples (Tyrrhenian Sea, Western Mediterranean). The sampling site, located between the littoral and the open sea systems, has very active hydrography that affects plankton communities. The present work was aimed at establishing whether, in such a dynamic and variable environment, species associations and homogeneous periods could be identified as characteristic and stable features of the mesozooplankton over the period 1984–2006. Hierarchical clustering was applied to assess species associations based on a matrix of similarities between species (R-mode), and homogeneous periods based on a matrix of similarities between observations (Q-mode). The Indicator Value index [IndVal, Dufrene and Legendre (1997) Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol. Monogr., 67, 345–366] was calculated to identify species characterizing each period. Five taxonomic groups with well-defined composition and abundance were identified as robust associations that likely reflect different modes of community functioning. The temporal course of these associations was largely shaped by strong seasonal forcing comprising both physical and biological (e.g. trophic) signals. These associations persisted over the long term, thus indicating some stable characters in the Naples zooplankton time-series, providing evidence of resilience in communities in highly variable coastal conditions