Market Performance of Potato Auctions in Bhutan

Market performance with respect to a main horticultural export commodity in Bhutan is the subject of this paper. Imperfections in (market) infrastructure and market structure and conduct may prevent an optimal price for farmers. Market performance is assessed by testing the law of one price for this commodity. This is done by testing three series of auction price data on both long-run and short-run price integration. It is concluded that auction prices were interrelated both in the long and short run with one of the three auctions as the price-leading market. Policy implications are suggested.Auctions, Bhutan, Law of one price, Market performance, Potato marketing, Marketing, C22, L1, M31, O1, Q13,

A time-resolved fluorescence immunoassay for the measurement of testosterone in saliva: Monitoring of testosterone replacement therapy with testosterone buciclate

Monitoring of testosterone replacement therapy requires a reliable method for testosterone measurement. Determination of salivary testosterone, which reflects the hormone's biologically active plasma fraction, is a superior technique for this purpose. The aim of the present study was to establish a new sensitive time-resolved fluorescence immunoassay for the accurate measurement of testosterone levels in saliva and to validate it by monitoring testosterone replacement therapy in eight hypogonadal men. A clinical phase I- study with the new ester testosterone buciclate was performed to search for new testosterone preparations to produce constant serum levels in the therapy of male hypogonadism. After two control examinations eight male patients with primary hypogonadism were randomly assigned to two treatment groups (n = 2x4) and given single doses of either 200 mg (group I) or 600 mg (group II) testosterone buciclate intramuscularly. Saliva and blood samples were obtained 1, 2, 3, 5 and 7 days post injection and then weekly for three months. The time-resolved fluorescence immunoassay for salivary testosterone shows a detection limit of 16 pmol/l, an intra-assay CV of 8.9% (at a testosterone concentration of 302 pmol/l), an inter-assay CV of 8.7% (at a testosterone concentration of 305 pmol/l) and a good correlation with an established radioimmunsassay of r = 0.89. The sample volume required by this method is only 180 mu l for extraction and duplicate determination. The assay procedure requires no more than three hours. In group I (200 mg) testosterone did not increase to normal levels either in saliva or in serum. However, in group II, androgen levels increased significantly and were maintained in the normal range for up to 12 weeks with maximal salivary testosterone levels of 303 +/- 18 pmol/l (mean+/-SE) and maximal testosterone levels of 13.1 +/- 0.9 nmol/l (mean+/-SE) in serum in study week 6 and 7. The time-resolved fluorescence immunoassay for salivary testosterone provides a useful tool for monitoring androgen status in men and women and is well suited for the follow-up of testosterone replacement therapy on an outpatient basis. The long-acting ester testosterone buciclate is a promising agent for substitution therapy of male hypogonadism and in combination with testosterone monitoring in saliva offers an interesting new perspective for male contraception

'Waterstreams': A model for estimation of crop water demand, water supply, salt accumulation and discharge for soilless crops

Abstract: Closed growing systems are obligatory for soilless grown greenhouse crops in The Netherlands. It requires water sources of high quality as sodium (Na) accumulation is a potential risk and necessitates frequent discharge, which causes undesirable emission of nutrients and plant protection products. Rainwater as the primary water source, needs to be stored since precipitation and crop demand do not match. Large dry spells will become more frequent due to climatic changes and this necessitates the use of additional water sources, which will differ in quality and costs. The model ‘WATERSTREAMS’ was developed to estimate the total water demand and waste water flows from greenhouse crops and to optimize between options for water sources, concerning Na accumulation and nutrient emission. It describes all water flows in a greenhouse crop and the growing system. At the same time the Na concentrations in the input flows as well as the uptake are calculated, and if Na accumulates beyond a threshold value, a discharge event is programmed. The model calculations can be used to determine the total water demand from individual crops to clusters of greenhouses, as well as to optimize the size of rainwater collection tanks or the required capacity of additional water sources, using actual, historical or forecasted meteorological data. It also gives insight in the emission quantity

First Observation of a Spontaneously Matured Female European Eel (Anguilla anguilla)

This study reports on the first observation of a spontaneously matured female European eel. The 43-year-old eel, together with eleven other females, resided at an aquarium house since their capture in 2002 and stocking as glass eels in 1978. In June 2019, the girth of the belly of the female increased as a sign of oocyte maturation. The specimen had an estimated gonadosomatic index (GSI) of 47, only half of the oocytes were hydrated and matured, indicating that European eels are polycyclic batch spawners. The live eels of the cohort were still in the previtellogenic phase but their eye sizes were close to that of the matured eel. We hypothesize that substances released by other maturing and spawning fishes may have triggered puberty of the eel. This first observation, and the possibility of more eels maturing in the near future, provides a natural reference for the sexual maturation of the European eel.</p