Determination of the spawning time and changes in the reproduction cycle of ribbon fish, Trichiurus lepturus, according to the hepatosomatic index and gonadosomatic index

The ribbon fishes, belonging to the family Trichiuridae, are one of the most important protein resources in the Indian Ocean. A considerable density of the dominant species of this family, Trichiurus lepturus has been observed in the Oman Sea. During the conducted cruises in the northern part of the Oman Sea, gonadosomatic index (GSI) and hepatosomatic index (HSI) were estimated according to the size of the female groups of Trichiurus lepturus. GSI increases significantly from September to next April (P <0.05). polymodal egg size frequency revealed prolong spawning time by the females. The HSI fluctuations are good indications for this type of reproductive behavior

Comparison of Different selenium Sources on Performance, Serum Attributes and Cellular Immunity in Broiler Chickens

The effects of organic and inorganic sources and concentration (0 and 0.3 mg per kg of diet) of Selenium (Se) on growth performance, blood biochemical and immune system were evaluated in broiler chickens. Chickens were fed corn-soy-based diets formulated to 8 dietary treatments containing no added Se (negative control), negative control plus yeast (positive control), and 6 diets had 0.3 mg/kg of diet supplemented with Se from Availa Se, Sel-plex, SeleMax, Se enriched yeast, sodium selenite and sodium selenate. Four hundred Ross 308 male chickens were randomly divided into 8 treatments and 5 replicates of 10 birds each. Feed intake, body weight gain, and feed conversion ratio were measured at starter (0-10 d), grower (11-24 d), and finisher (25-42 d) periods. On d 24 and 42, one bird from each replicate was killed by cervical dislocation and blood samples were collected to determine blood chemicals, glutathione peroxidase (GPx) activity and heterophile to lymphocyte ratio. Results showed that Se supplementation had no effect on feed intake, body weight gain, and feed conversion ratio of the chickens (P < 0.05). However, blood triglycerides, GPx activity and heterophile to lymphocyte ratio were significantly affected by organic and inorganic Se sources (P < 0.05). Results showed that selenium in organic and inorganic forms didn't have any effect on growth performance and blood parameters but they could improve immune system through increase in GPx activity

Optimization of breeding (salinity, light regime, brood density and sex ratio) of cultured tilapia under brackish water of Bafgh, Iran

Tilapia is one of the most important cultured fish in the world. World production of tilapia is highly increased in recent decades. Tilapias can live in different aquatic ecosystems due to their reproductive strategies. On the other hand, the gap between seed supplies and farmers' demand is one of the most serious limitations for tilapia culturists. Notice about different effective agents on tilapia reproduction aspects might be useful for increasing of production and better management of tilapia hatcheries. Studies about tilapia were started in Iran from November 2008 for the first time. Some reproductive normative of cultured tilapia in brackishwater were defined. In the present study, sex ratio, stocking density, photoperiod, water salinity and replacement period of female brooders of the Nile tilapia, Oreochromis niloticus were investigated. Studied reproduction indices showed sex ratio 1:1 (F:M), stocking density 5/m3, photoperiod 12:12 (L:D), 8ppm water salinity and 10 days replacement of brooders were suitable

An investigation on feasibility of introduction of tilapia to aquaculture industry of inland brackish waters at desert areas of Iran

Use of underground inland water for fisheries aims is improved all over the world. Tilapia is the first candidate for brackish water fish culture and an economic fish based on its biological characteristics. Tilapia was entered to Iran for the first time in November 2008. Bafq area at the center of Iran was licensed by Environment Organization, because of closed underground water resources of the area. Studies showed desired growth and adaptation of Nile tilapia in brackish water earth ponds and fiber glass tanks with high survival and low FCR. Limnological factors were suitable for tilapia culture. All male samples were made using certain doses of methyl testosterone in defined period. Optimum level of protein, fat and energy were determined for the best growth and food performance of cultured tilapia. Environmental program was presented to prevent environmental problems. However, studied shoed tilapia culture had not negative effects in the area. Economical performance of tilapia culture project was desirable. Tilapia was successfully introduced to some private fish farms in June 2011. Tilapia culture may improve in center of Iran after environmental surveys

Liquid-infiltrated photonic crystals - enhanced light-matter interactions for lab-on-a-chip applications

Optical techniques are finding widespread use in analytical chemistry for chemical and bio-chemical analysis. During the past decade, there has been an increasing emphasis on miniaturization of chemical analysis systems and naturally this has stimulated a large effort in integrating microfluidics and optics in lab-on-a-chip microsystems. This development is partly defining the emerging field of optofluidics. Scaling analysis and experiments have demonstrated the advantage of micro-scale devices over their macroscopic counterparts for a number of chemical applications. However, from an optical point of view, miniaturized devices suffer dramatically from the reduced optical path compared to macroscale experiments, e.g. in a cuvette. Obviously, the reduced optical path complicates the application of optical techniques in lab-on-a-chip systems. In this paper we theoretically discuss how a strongly dispersive photonic crystal environment may be used to enhance the light-matter interactions, thus potentially compensating for the reduced optical path in lab-on-a-chip systems. Combining electromagnetic perturbation theory with full-wave electromagnetic simulations we address the prospects for achieving slow-light enhancement of Beer-Lambert-Bouguer absorption, photonic band-gap based refractometry, and high-Q cavity sensing.Comment: Invited paper accepted for the "Optofluidics" special issue to appear in Microfluidics and Nanofluidics (ed. Prof. David Erickson). 11 pages including 8 figure

Population genetic molecular study of Penaeus semisulcatus from Persian Gulf and Oman Sea by using of Cytochrome oxidized COI and RFLP method

Goals: Determine of barcode of DNA in green tiger prawn, Penaeus semisulcatus, in the Gen bank of the species. Material and methods: In these study 30 specimens of Penaeus semisulcatus from each region in the Persian Gulf and Sea of Oman were sampled and preserved in ethanol 96%. The total DNA was extracted, COI gene was first amplified and then sequenced for each species. Finally the collected data were analyzed with the specific phylogenetic software. Result and discussion: Molecular analysis revealed some degree of interpopulation differences within two areas. Also for population study molecular data of species Penaeus semisulcatus were analysed base on COI RFLP and 16SrRNA sequences respectively. The results indicated that COI gen is a good marker for shrimp species differentiation that would be helpful to protect shrimp species

Optimum management of warmwater fish farms stocking, capacity determination, growth rate and brood stock managements and harvesting

This study was conducted to codify the guideline and indexes of optimal management in warm-water fish farms to attain sustainable aquaculture which they are population density, species diversity, brood stock'smanagements, capacity determination, growth and harvesting managements in cultural ponds. As results, these guideline and indexes were codifies for these fish farms and propagation centers. It's obviously that these sustainable patterns can be used for improving of permanent development for this aquacultural industry

Optomechanical Crystals

Structured, periodic optical materials can be used to form photonic crystals capable of dispersing, routing, and trapping light. A similar phenomena in periodic elastic structures can be used to manipulate mechanical vibrations. Here we present the design and experimental realization of strongly coupled optical and mechanical modes in a planar, periodic nanostructure on a silicon chip. 200-Terahertz photons are co-localized with mechanical modes of Gigahertz frequency and 100-femtogram mass. The effective coupling length, which describes the strength of the photon-phonon interaction, is as small as 2.9 microns, which, together with minute oscillator mass, allows all-optical actuation and transduction of nanomechanical motion with near quantum-limited sensitivity. Optomechanical crystals have many potential applications, from RF-over-optical communication to the study of quantum effects in mesoscopic mechanical systems.Comment: 16 pages, 7 figure

Dynamic manipulation of mechanical resonators in the high amplitude regime through optical backaction

Cavity optomechanics enables active manipulation of mechanical resonators through backaction cooling and amplification. This ability to control mechanical motion with retarded optical forces has recently spurred a race towards realizing a mechanical resonator in its quantum ground state. Here, instead of quenching optomechanical motion, we demonstrate high amplitude operation of nanomechanical resonators by utilizing a highly efficient phonon generation process. In this regime, the nanomechanical resonators gain sufficient energy from the optical field to overcome the large energy barrier of a double well potential, leading to nanomechanical slow-down and zero frequency singularity, as predicted by early theories . Besides fundamental studies and interests in parametric amplification of small forces, optomechanical backaction is also projected to open new windows for studying discrete mechanical states, and to foster applications. Here we realize a non-volatile mechanical memory element, in which bits are written and reset via optomechanical backaction by controlling the mechanical damping across the barrier. Our study casts a new perspective on the energy dynamics in coupled mechanical resonator - cavity systems and enables novel functional devices that utilize the principles of cavity optomechanics.Comment: 22 pages, 5 figure