Watersheds are Schramm-Loewner Evolution curves

We show that in the continuum limit watersheds dividing drainage basins are Schramm-Loewner Evolution (SLE) curves, being described by one single parameter $\kappa$. Several numerical evaluations are applied to ascertain this. All calculations are consistent with SLE$_\kappa$, with $\kappa=1.734\pm0.005$, being the only known physical example of an SLE with $\kappa<2$. This lies outside the well-known duality conjecture, bringing up new questions regarding the existence and reversibility of dual models. Furthermore it constitutes a strong indication for conformal invariance in random landscapes and suggests that watersheds likely correspond to a logarithmic Conformal Field Theory (CFT) with central charge $c\approx-7/2$.Comment: 5 pages and 4 figure

Effect of stocking density on the growth of Gracilariopsis persica and Gracilaria corticata, with the potential for mariculture in Persian Gulf

This study was conducted to investigate the effect of initial stocking density of red algae Gracilaropsis persica and Gracilaria corticata on the growth and biomass production of these species. Three stocking densities of 50 gm^-1, 125 gm^-1 and 200 gm^-1 were used and algae cultivated in Persian Gulf (Bandar Abbas) in winter for 45 days. Algae collected from natural environment and cultivated on poly ethylene rope in the sea. Relative growth rate (RGR) and total biomass were measured fortnightly. Temperature, salinity, pH and nutrients (nitrate, nitrite and phosphate) were measured during the trial. The result of the present study showed that there were significant differences in growth rate between different treatments in both species (P<0.05). Algae that cultivated with 50 gm^-1 initial stocking density had the highest relative growth rate in both species. At the end of 45-day trial, total biomass was the highest in 200 gm^-1 treatment (P<0.05). Furthermore, the present study showed that the growth rate of Gracilariopsis persica was higher than Gracilaria corticata. The results of the present study showed that stocking density is able to affect the growth of red algae Gracilariopsis persica and Gracilaria corticata and Gracilariopsis persica have higher growth rate and better potential of commercial culture in the Persian Gulf compared to Gracilaria corticata

Monitoring of Cochlodinium sp for shrimp farms in Hormozgan Province

The Blooming due to the some species of phytoplanktons especially Dynoflagellates has made some problems for water ecosystems and aquaculture. In this study, the density of phytoplanktons specially Cochlodinium sp. and also environmental factors such as temperature, pH, dissolved Oxygen, and transparency were recorded two weekly in 18 stations of Hormozgan province, Iran in order to monitoring of the possibility of phytoplankton blooming. During six months monitoring, the target phytoplankton, Cochlodinium sp was not observed in shrimp farms. But, other phytoplanktons and zooplanktons were observed as follow: 13 genus of phytoplankton and six genuses of zooplanktons has found in ponds, main water channel and sea. The diatoms with 10 genuses had the highest abundance and Dynoflagellates with 3 genuses had the lowest abundance and blue-green phytoplankton with one genus was in lowest group. Totally, diatoms with 77%, Dynoflagellate with 15% and blue-green alga with 8% abundance were the main populations of planktons in the studied area

Germination and bioactivity of Trichoderma atroviride affected by culturing and storage conditions

Identification of the production and storage factors that affect conidial germination and bioactivity (fitness) will assist the success of biological control agents. Effects of culturing conditions on conidial fitness of Trichoderma atroviride LU132 were examined in different storage conditions over time. Abiotic factors (temperature, nutrients, water activity, pH) during production were studied. Conidia from the culturing regimes which resulted in greatest and least bioactivity against Rhizoctonia solani in dual culture were selected to assess effects of storage condition on conidial fitness. Fitness of the test conidia was examined after storage at 30°C and at 0 or 50% relative humidity (RH) over 6 months. Fitness declined over time, and the decline was greater for 50% RH than 0% RH. The greatest number of conidia and germination percentage resulted from conidia produced at 25°C, but greatest bioactivity resulted from those produced at 30°C. Different C to N ratios (5:1 or 160:1) did not affect these parameters. However, fewer conidia were produced at 30°C, and the least germination and bioactivity resulted from conidia produced at 20°C. Conidia can be divided into two groups: those adapted to extreme culturing conditions (e.g. high temperature), and those protected by nutrients during storage. However, environmental factors are not independent. For example, conidial production at 30°C is probably accompanied by water stress, oxidation, and rapid pH change which may also affect fitness