The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

Some key aspects of the reproductive strategy of the brown trout (Salmo trutta fario L.) in the Yadong River, Tibet, including spawning season, age at sexual maturity, fecundity and egg size, have been studied. The majority of the samples were less than 215 mm and age ranged from 1 to 4 in both sexes, indicating that the majority of the fish were younger and the pressure by overfishing was high. The spawning periodicity was determined to be between the end of October and January, mainly in November and December. The ratio of male to female brown trout population (1.29:1 with P > 0.05) suggested no sex significant differences, although males were significantly more abundant than females in October (P < 0.0001) on monthly basis. Age and size of males and females at maturity was different and males matured earlier than females. Fecundity was markedly correlated with their body weight (P < 0.001, r = 0.9255), standard length (P < 0.01, r = 0.8879), and gonad weight (P < 0.001, r = 0.9366). The mean size of mature eggs in the spawning season was: 4.0 +/- 0.45 mm and tended to increase along with the female spawners size (P < 0.001, r = 0.9641). Further researches about the brown trout population in the Yadong River should be conducted on issues such as artificial reproduction, culture, conservation, management, and restocking.

Regulation of gamete release in the economic brown seaweed Hizikia fusiforme (Phaeophyta)

Gamete release is an essential event in artificial seeding of the economic brown seaweed, Hizikia fusiforme. Mass egg release occurred in the dark, with few eggs being discharged in the light. Release of eggs was elicited with eight practical salinity units (one PSU = 1 g sea salts l(-1)) and was inhibited by salinity levels > 32 PSU. Egg release was optimal at 23 degrees C, and was decreased by 72% in agitated seawater compared to unstirred seawater. Inhibitors of photosynthesis and ions channels suppressed egg release, indicating that this process was physiologically associated with photosynthetic activity and ion transport.

Photosynthetic characteristics of the economic brown seaweed Hizikia fusiforme (Sargassaceae, Phaeophyta), with special reference to its "leaf" and receptacle

Photosynthetic responses to irradiance and temperature of "leaves" and receptacles were compared in February ( vegetative stage) and May ( reproductive stage) in the seaweed, Hizikia fusiforme ( Harvey) Okamura (Sargassaceae, Phaeophyta) from Nanao Island, Shantou, China. Irradiance-saturated photosynthesis (P-max) was significantly higher in receptacles than in "leaves" on a fresh weight basis, and that of "leaves" was greater in May than in February at ambient seawater temperatures. The optimum temperature for P-max was 30 degrees C for both "leaves" and receptacles, being 5 - 10 degrees C higher than the ambient seawater temperature. The apparent photosynthetic efficiencies were greater in receptacles than in "leaves" within the tested temperature range of 10 - 40 degrees C. The irradiance for saturating photosynthesis for both "leaves" and receptacles was temperature-dependent, with the highest values ( about 200 mu mol photons m(-2) s(-1)) at 30 degrees C.

Photosynthetic utilization of inorganic carbon in the economic brown alga, Hizikia Fusiforme (Sargassaceae) from the South China Sea

The mechanism of inorganic carbon (C-i) acquisition by the economic brown macroalga, Hizikia fusiforme (Harv.) Okamura (Sargassaceae), was investigated to characterize its photosynthetic physiology. Both intracellular and extracellular carbonic anhydrase (CA) were detected, with the external CA activity accounting for about 5% of the total. Hizikia fusiforme showed higher rates of photosynthetic oxygen evolution at alkaline pH than those theoretically derived from the rates of uncatalyzed CO2 production from bicarbonate and exhibited a high pH compensation point (pH 9.66). The external CA inhibitor, acetazolamide, significantly depressed the photosynthetic oxygen evolution, whereas the anion-exchanger inhibitor 4,4'-diisothiocyano-stilbene-2,2'-disulfonate had no inhibitory effect on it, implying the alga was capable of using HCO3- as a source of C-i for its photosynthesis via the mediation of the external CA. CO2 concentrations in the culture media affected its photosynthetic properties. A high level of CO2 (10,000 ppmv) resulted in a decrease in the external CA activity; however, a low CO2 level (20 ppmv) led to no changes in the external CA activity but raised the intracellular CA activity. Parallel to the reduction in the external CA activity at the high CO2 was a reduction in the photosynthetic CO2 affinity. Decreased activity of the external CA in the high CO2 grown samples led to reduced sensitiveness of photosynthesis to the addition of acetazolamide at alkaline pH. It was clearly indicated that H. fusiforme, which showed CO2-limited photosynthesis with the half-saturating concentration of C-i exceeding that of seawater, did not operate active HCO3- uptake but used it via the extracellular CA for its photosynthetic carbon fixation.

Degree of fourth-order coherence by double Hanbury Brown-Twiss detections

Photon quantum statistics of light can be shown by the high-order coherence. The fourth-order coherences of various quantum states including Pock states, coherent states, thermal states and squeezed vacuum states are investigated based on a double Banbury Brown Twiss (HBT) scheme. The analytical results are obtained by taking the overall efficiency and background into account.

Identified particle production, azimuthal anisotropy, and interferometry measurements in Au plus Au collisions at root s(NN)=9.2 GeV

We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au + Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance solenoidal tracker at RHIC (STAR) detector at root s(NN) = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density dN/dy in rapidity y, average transverse momentum < p(T)>, particle ratios, elliptic flow, and Hanbury-Brown-Twiss (HBT) radii are consistent with the corresponding results at similar root s(NN) from fixed-target experiments. Directed flow measurements are presented for both midrapidity and forward-rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, < p(T)>, and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for root s(NN) = 200 GeV, are suitable for the proposed QCD critical-point search and exploration of the QCD phase diagram at RHIC.

A study of fucoidan from the brown seaweed Chorda filum

Fucoidan fractions from the brown seaweed Chorda filum were studied using solvolytic desulfation.Methylation analysis and NMR spectroscopy were applied for native and desulfated polysaccharides.Homefucan sulfate from C.filum was shown to contain poly-a-(1-3)-fucopyranoside backbone with a high degree of branching,mainly of a-(1-2)-linked single units.Some fucopyranose residues are sulfated at O-4(mainly) and O-2 positions.Some a-(1-3)-linked fucose residues were shown by NMR to be 2-O-acetylated.The 1H and 13C NMR spectra of desulfated,deaceylated fucan were complerely assigned.THe spectral data obtained correspond to a quasiregular polysaccharide structure with a branched hexasaccharide repeating unit.Other fucoidan frations from C.filum have more complex carbohydrate composition and give rather complex methvlation patterns.

A fucoidan fraction from Ascophyllum nodosum

A fucoidan fraction was purified from the brown alga Ascophyllum nodosum. The polysaccharide contained -fucose and sulfate as the only constituents. Combination of methylation analysis, Smith degradation, FTIR and NMR spectroscopy on the native and the de-sulfated polymers demonstrated that the fucoidan consisted of a highly branched core region with primarily α-(1→3)-linked fucosyl residues and a few α-(1→4) linkages. Branch points were at position 2 of the →3-linked internal residues. The side chains consisted of single and multi-unit fucosyl residues. The combined analytical data suggested also a complex sulfation pattern with substitution principally at position 2 and/or position 4. Such diversity in the structural features of this fucoidan may be of importance for its various biological properties.

Defensive and Sensory Chemical Ecology of Brown Algae

The ecological interaction of brown algae are important as these macroalgae are common and often keystone members in many benthic marine communities.This review highlights their chemical interactions,particularly with potential herbivores,but also with fouling oranganisms,with potential pathogens,with each other as gametes,and with their microenvironments when they are spores.Phlorotannins,which are phenolic compounds unique to brown algae,have been studied hesvily in many of these respects and sre highlightes here.This includes recent controversy about their roles as defences against herbivory,as well as new understanding of their roles in primary cellular functions that may,in many instances,be more important than ,and which at least have to be considered in convert with,any possible ecological functions.Brown algae have also been useful models for testing theoties about the evolution of and ecological constraints on chemical defence.Furthermore,their mocroscopic motile gametes and spores have the ability to react to their chemical environments behavirourally.

Biosorption of Cd2+, Cu2+, Ni2+ and Zn2+ ions from aqueous solutions by pretreated biomass of brown algae

In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+.

Biosorption of Cd2+, Cu2+, Ni2+ and Zn2+ ions from aqueous solutions by pretreated biomass of brown algae

In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1 and EC2), or oxidizing by potassium permanganate (PC), or crosslinking with glutaraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd2+, Cu2+, Ni2+ and Zn2+. The experimental data have been analyzed using Langmuir, Freundlich and Redlich-Peterson isotherms. The results showed that the biosorption equilibrium was well described by both the Langmuir and Redlich-Peterson isotherms.