Observations on gynes and drones around nuptial flights in the stingless bees Tetragonisca angustula and Melipona beecheii (Hymenoptera, Apidae, Meliponinae)

The nuptial flight of gynes of Tetragonisca angustula and Melipona beecheii was studied. The moment of nuptial flight was found to be related to the ambient temperature, and the duration of the nuptial flight for M. beecheii was longer in November (rainy season) than in March (dry season). A repeated mating flight was recorded for two gynes of T. angustula. Three of five T. angustula queens and all six M. beecheii queens were mated successfully. Behavioural data of drones and gynes shortly before and after the nuptial flight are presented. Drones of T. angustula participated in a congregation for up to three days. The importance of pheromones for the attraction of drones and gynes is discussed. An hypothesis explaining the observed seasonal occurrence of male congregations near nests of T. angustula is presented

A novel astronomical application for formation flying small satellites

OLFAR, Orbiting Low Frequency Antennas for Radio Astronomy, will be a space mission to observe the universe frequencies below 30 MHz, as it was never done before with an orbiting telescope. Because of the ionospheric scintillations below 30 MHz and the opaqueness of the ionosphere below 15 MHz, a space mission is the only opportunity for this as yet unexplored frequency range in radio astronomy. The frequency band is scientifically very interesting for exploring the early cosmos at high hydrogen redshifts, the so-called dark-ages and the epoch of reionization, the discovery of planetary and solar bursts in other solar systems, for obtaining a tomographic view of space weather, ultra-high energy cosmic rays and for many other astronomical areas of interest. Because of the low observing frequency the aperture size of the instrument must be in the order of 100 km. This requires a distributed space mission which is proposed to be implemented using formation flying of small satellites. The individual satellites are broken down in five major subsystems: the spacecraft bus, the antenna design, the frontend, backend and data transport. One of the largest challenges is the inter-satellite communication. In this paper the concept and design considerations of OLFAR are presented

Nitrogen and energy balance of a short-rotation poplar forest system.

The mean annual dry matter production of a short-rotation poplar forest in the Netherlands was 14.4 tonnes ha-1 during a 5-year growing period. During the growing period trees took up 542 kg N ha-1 of which 64 % was in the bole and branches. In the 5th year denitrification was measured in undisturbed columns in the field by the acetylene-inhibition technique. An annual denitrification rate of 18 kg N ha-1 was estimated on the basis of the observed N2O profile. The system needed an annual input of 122 kg N ha-1 to balance the nitrogen budget. The energy balance showed that at the present dry matter production the system had a net output of 54 GJ ha-1 year-1. An increase in dry matter production to a maximum of 25 tonnes ha-1 year-1, possible by planting the trees at a higher density, would raise the net energy output to 97 GJ ha-1 year-1, in spite of higher energy inputs associated with fertilizer applications. (Abstract retrieved from CAB Abstracts by CABI’s permission

Analyzing generic and branded substitution patterns in the Netherlands using prescription data

BACKGROUND: As in other societies, pharmaceutical expenditures in the Netherlands are rising every year. As a consequence, needs for cost control are often expressed. One possible solution for cost control could come through increasing generic substitution by pharmacists. We aim to analyse the extent and nature of substitution in recent years and estimate the likelihood of generic or branded substitution in Dutch pharmacies in relation to various characteristics. METHODS: We utilized a linked prescription dataset originating from a general practitioner (GP) and a pharmacy database, both from the northern Netherlands. We selected specific drugs of interest, containing about 55,000 prescriptions from 15 different classes. We used a crossed generalized linear mixed model to estimate the effects that certain patient and pharmacy characteristics as well as timing have on the likelihood that a prescription will eventually be substituted by the pharmacist. RESULTS: Generic substitution occurred at 25% of the branded prescriptions. Generic substitution was more likely to occur earlier in time after patent expiry and to patients that were older and more experienced in their drug use. Individually owned pharmacies had a lower probability of generic substitution compared to chain pharmacies. Oppositely, branded substitution occurred in 10% of generic prescriptions and was positively related to the patients' experience in branded use. Individually owned pharmacies were more likely to substitute a generic drug to a branded compared to other pharmacies. Antidepressant and PPI prescriptions were less prone to generic and more prone to branded substitution. CONCLUSION: Analysis of prescription substitution by the pharmacist revealed strong relations between substitution and patient experience on drug use, pharmacy status and timing. These findings can be utilised to design further strategies to enhance generic substitution

Influence of water on the sulfidation of Co/NaY and Co/CaY prepared by impregnation, A. Mössbauer Emission spectroscopy and EXAFS Study

The influence of physisorbed water on the sulfidation of impregnation type Co/NaY(imp) and Co/CaY(imp) catalysts which contain about 4 wt % Co and are prepared via pore volume impregnation is studied by Mossbauer emission spectroscopy and extended X-ray absorption fine structure. It is found that in the absence as well as in the presence of water, sulfidation of the impregnated samples finally results in the formation of Co9S8-like species at the outer zeolite surface. In the presence of water, this process proceeds via the intermediate formation of a well-ordered ''CoS1+x'' phase (NiAs structure). Water removal prior to sulfidation retards the formation of Co9S8-like species. This retardation in Co9S8 formation is found to be more effective for CaY-zeolite than for NaY- zeolite, which means that a larger part of the formed ''Co- sulfide'' is preserved in highly dispersed ''Co-sulfide'' particles. These findings are clearly different from those obtained earlier with ion exchanged CoNaY(ion ex) samples, for which drying prior to sulfidation resulted in very small ''Co- sulfide'' species with no resemblance to ''Co9S8'

Financial problems and psychological distress: Investigating reciprocal effects among business owners

Abstract: Building on conservation of resources theory and the dynamic equilibrium model, this threewave longitudinal study among 302 Dutch agricultural business owners (one-year time intervals) investigated reciprocal relationships between the financial situation of the business and psychological distress. Results of structural equation modeling analyses revealed a negative spiral of farm decline, in which psychological variables played a key role. Experiencing financial problems predicted psychological distress, and acted as a self-fulfilling prophecy by strengthening intentions to quit the business, which predicted a deterioration of the objective financial situation of the business one year later. Moreover, farmers experiencing more psychological distress were more likely to get caught in this negative spiral than business owners with better mental health, because they experienced more financial problems, irrespective of their objective financial situation. Long-term psychological distress rather than temporary fluctuations in distress levels accounted for this effect