Investigating and determination exploitation pattern of jinga shrimp (M.affinis) in the Khouzestan Province waters

Study of shrimp stock was carried out from September 2007 to November 2009 in west of Khuzestan coastal waters. In this period, twelve cruises in Life- Buseif (western coastal area) were carried using shrimp trawl net. In Life- Buseif fishing area, the CPUE of total shrimp was the highest (44.2 kg/h) in 21st October 2008. In this area, the highest biomass of total shrimps was in same time (982.4 t). This value was 808.5 t for M. affinis. Maximum mean length of males and females of M.affinis were observed in 4th November 2009 (12.1 & 11.3 cm respectively). Maximum and minimum sex ratio (f:m) of this species was 1.8:1 in 15th November 2008 and 0.6:1 in 3rd November 2008. Relative frequency of shrimp in total catch was observed in November (22.2%). According to the results of this study, shrimp catch season was opened in Life- Buseif from 4th Nov until 24th Dec 2007, from 24th Oct until 14th Dec 2008 and from 27th Oct until 17th Dec 2009

Polychromatic solitons in a quadratic medium

We introduce the simplest model to describe parametric interactions in a quadratically nonlinear optical medium with the fundamental harmonic containing two components with (slightly) different carrier frequencies [which is a direct analog of wavelength-division multiplexed (WDM) models, well known in media with cubic nonlinearity]. The model takes a closed form with three different second-harmonic components, and it is formulated in the spatial domain. We demonstrate that the model supports both polychromatic solitons (PCSs), with all the components present in them, and two types of mutually orthogonal simple solitons, both types being stable in a broad parametric region. An essential peculiarity of PCS is that its power is much smaller than that of a simple (usual) soliton (taken at the same values of control parameters), which may be an advantage for experimental generation of PCSs. Collisions between the orthogonal simple solitons are simulated in detail, leading to the conclusion that the collisions are strongly inelastic, converting the simple solitons into polychromatic ones, and generating one or two additional PCSs. A collision velocity at which the inelastic effects are strongest is identified, and it is demonstrated that the collision may be used as a basis to design a simple all-optical XOR logic gate.Comment: 9 pages, 8 figures, accepted to Phys. Rev.

Biological aspects of Sepia pharaonis in the Bahrekan waters (NW Persian Gulf)

The biological aspects of Sepia pharaonis was studied during years 2006-07. The studied area restricted to the Bahrekan in Khouzestan province covering the depths of 2 up to 25m. The sampling methods were gillnet and bottom trawl. A total of 310 specimens collected, of which there wasn’t found any cuttlefish in the study area from July to October (5 months). The collected samples were transferred to the laboratory ashore for further biological measurements consist of: Mantle length, Body weight, sex determination. Gonado-Somatic Index, and determination of Spermatophoric Index, Spawning season, Food preference, Maturity stages and chemical analysis for food value determination. The results showed that the overall sex ratio is about M:F= 2:1 with percentage of 67.41% for males and 32.50% for females. Males are significantly bigger than females with average mantle length (ML) of 233.3 and 269.3 mm for female and male, respectively; with body weight of 1102.3 and 1450.6 g. The mantle length body weight relationship was found W=0.001 ML 2.540 (R2= 0.92) Female as: W= 0.0015 ML 4797 (R2= 0.93) male From point of feeding, the food preferences results indicated that fish is considered as main food, crabs as minor food and other marine organisms such as bivalvia and gastropods as random food. The highest vacuity Index (CV) and empty stomachs was determined for March-April and the lowest value was is December. Also, the maximum GSI was estimated for March-April months in which showing coherrances with the lowest food preference. The maximum spermatophoricfilaments were 856 and 45 for male pharaoh cuttlefish with mantle length of 300 and 185 mm, and on the other hand this values for fecundity were estimated 1589 and 53 for female specimens with 254 and 198 mm mantle length. The spawning season occurs in April- March in which accompany with migration of pharaoh cuttlefish towards shallow waters. The fishing season would be in this period in w

The first X-ray survey of Galactic Luminous Blue Variables

Aims: The X-ray emission of massive stars has been studied when these objects are in their main-sequence phase, as well as in their Wolf-Rayet phase. However, the X-ray properties of the transitional Luminous Blue Variable (LBV) phase remain unknown. Methods: Using a dedicated but limited XMM survey as well as archival XMM and Chandra observations, we performed the first X-ray survey of LBVs: about half of the known LBVs or candidate LBVs are studied. Results: Apart from the well known X-ray sources eta Car and Cyg OB2 #12, four additional LBVs are detected in this survey, though some doubt remains on the association with the X-ray source for two of these. For the other LBVs, upper limits on the flux were derived, down to $\log[L_{\rm X}/L_{\rm BOL}]-9.4$ for PCyg. This variety in the strength of the X-ray emission is discussed, with particular emphasis on the potential influence of binarity.Comment: 13 pages, 2 figures, accepted by A&

RepSeq-A database of amino acid repeats present in lower eukaryotic pathogens

BACKGROUND Amino acid repeat-containing proteins have a broad range of functions and their identification is of relevance to many experimental biologists. In human-infective protozoan parasites (such as the Kinetoplastid and Plasmodium species), they are implicated in immune evasion and have been shown to influence virulence and pathogenicity. RepSeq http://repseq.gugbe.com is a new database of amino acid repeat-containing proteins found in lower eukaryotic pathogens. The RepSeq database is accessed via a web-based application which also provides links to related online tools and databases for further analyses. RESULTS The RepSeq algorithm typically identifies more than 98% of repeat-containing proteins and is capable of identifying both perfect and mismatch repeats. The proportion of proteins that contain repeat elements varies greatly between different families and even species (3 - 35% of the total protein content). The most common motif type is the Sequence Repeat Region (SRR) - a repeated motif containing multiple different amino acid types. Proteins containing Single Amino Acid Repeats (SAARs) and Di-Peptide Repeats (DPRs) typically account for 0.5 - 1.0% of the total protein number. Notable exceptions are P. falciparum and D. discoideum, in which 33.67% and 34.28% respectively of the predicted proteomes consist of repeat-containing proteins. These numbers are due to large insertions of low complexity single and multi-codon repeat regions. CONCLUSION The RepSeq database provides a repository for repeat-containing proteins found in parasitic protozoa. The database allows for both individual and cross-species proteome analyses and also allows users to upload sequences of interest for analysis by the RepSeq algorithm. Identification of repeat-containing proteins provides researchers with a defined subset of proteins which can be analysed by expression profiling and functional characterisation, thereby facilitating study of pathogenicity and virulence factors in the parasitic protozoa. While primarily designed for kinetoplastid work, the RepSeq algorithm and database retain full functionality when used to analyse other species