Modelling farm-level economic potential for conversion to organic farming

This paper discusses linear programming simulations at individual farm-level of potential income changes that may result from conversion to organic farming. The model is based on both conventional farm accountancy data and additional conventional and organic farm data from sector expertise and literature. The model is applied for Belgian agriculture. Simulations show that economic potential for conversion is higher than generally perceived, provided that farmers are willing to change farm management practices. However, the economic conversion potential (ECP) is not positive for all farms, not even when an optimal conversion process is assumed and it depends on farm type and farm characteristics. Additionally, due to higher risk and liquidity problems during the transition period, the positive results need to be put into perspective. Nevertheless, the differentiated ECP calculations can give new insights supporting farm-level policy choices with respect to conversion to organic farming.     

Differences in the fragrances of pollen,leaves, and floral parts of garland (Chrysanthemum coronarium) and composition of the essential oils from flowerheads and leaves

Headspace analyses of pollen, whole flowerheads, ligulate and tubular florets, flower buds, involucral bracts, and leaves have been performed on the food plant Chrysanthemum coronarium L. (Asteraceae). The analyses permitted differences in the pattern of volatiles emitted by the different floral parts to be observed and the site and phenological stage of emission of these chemicals to be verified. Camphor and cis-chrysanthenyl acetate were emitted mainly by ligulate and tubular florets; the production of myrcene and (Z)-ocimene was higher in the flower buds, whereas beta-caryophyllene, (E,E)-alpha-farnesene, and (E)-beta-farnesene seemed attributable mainly to the involucral bracts. The leaves showed a quite different volatile profile, with (Z)-ocimene as the main constituent. Pollen showed a completely different composition of its volatiles, with perilla aldehyde, cis-chrysanthenyl acetate, and camphor among the principal compounds; many carbonylic compounds and linear hydrocarbons have been detected exclusively in pollen. Furthermore, the essential oils obtained from flowerheads and leaves have been studied. These samples showed mainly quantitative differences. Camphor (22.1%) and cis-chrysanthenyl acetate (19.9%) were the main constituents of the oil from flowers, whereas the oil from the leaves contained mainly (Z)-ocimene (45.4%) and myrcene (28.2%).     

Phase transitions in the starch-water system studied by adiabatic scanning calorimetry

We report high-precision measurements of phase transitions in the starch-water system by using for the first time adiabatic scanning calorimetry (ASC). Potato starch and nixtamalized corn flours were studied by this technique as a function of the moisture content. We calculated the percentage of gelatinized starch granules, as a function of the temperature, for both flours. For bi-phasic behavior in potato starch, at intermediate water contents, we propose an explanation based on previous hypotheses and on the experimental behavior as deduced from ASC measurements. ASC results suggest, in the case of nixtamalized corn flour, that uniform moisture is present in corn starch granules for all the considered moistures. A shift to higher temperatures of the peak temperature is observed when comparing the c(p)(T) curves with the classical DSC endotherms as measured for this flour. For both flours we estimated from the ASC results the melting temperatures of the starch granules, at zero moisture content, by using Flory's equation.     

Differences in the fragrances of pollen and different floral parts of male and female flowers of Laurus nobilis

The headspace analyses of pollen, whole living female and male flowers, and staminoids have been performed on Laurus nobilis L. (Lauraceae) from Italy to determine whether there are differences in the volatiles emitted in order to give a contribution to the roles of the different flower parts in the pollination ecology of dioecious plants. Also, the essential oils obtained from male and female plants have been studied to evaluate a possible correlation between the spontaneously emitted volatiles and the constituents stored in the glandular tissues. Furthermore, the headspace sampling technique has been improved, with respect to previously employed methods, by means of solid-phase microextraction (SPME).     

Composition of the essential oil of Mentha microphylla from the Gennargentu Mountains (Sardinia,Italy)

The essential oil obtained by hydrodistillation of the fresh aerial parts of Mentha microphylla C. Kock (Lamiaceae) collected on the Gennargentu Mountains (Sardinia, Italy) has been investigated by gas chromatography (GC) and GC/mass spectrometry (MS). The main constituents that resulted were pulegone (34.1%), piperitenone oxide (32.9%), and piperitenone (11.3%). The presence of small amounts of compounds such as ethyl hexanoate, 1-octen-3-ol, nonanal, and ethyl 2-methylbutanoate could justify the particular odorous profile of the plant, resembling the aroma of milk and other dairy products such as mozzarella.     

Population sizes, site fidelity and residence patterns of Australian snubfin and Indo-Pacific humpback dolphins: Implications for conservation

Very little is known about the ecology of snubfin Orcaella heinsohni and Indo-Pacific humpback dolphins Sousa chinensis in Australian waters. We used photo-identification data collected between 1999 and 2002 in Cleveland Bay, northeast Queensland, to estimate abundance, site fidelity and residence patterns of these species in order to make recommendations for their effective conservation and management. Our abundance estimates indicate that less than a hundred individuals of each species inhabit this coastal area. Even with relatively unbiased and precise abundance estimates population trends will be extremely difficult to detect in less than three years unless changes in population size are very high (>20% p.a.). Though both species are not permanent residents in Cleveland Bay, they both used the area regularly from year to year following a model of emigration and reimmigration. Individuals of both species spend periods of days to a month or more in coastal waters of Cleveland Bay before leaving, and periods of over a month outside the study area before entering the bay again. Because of their small population sizes and movement patterns, snubfin and humpback dolphins are particularly vulnerable to local extinction. Our results illustrate that: (1) detection of population trends should not be a necessary criterion for enacting conservation measures of both species in this region, and (2) efforts to maintain viable populations of both species in Cleveland Bay must include management strategies that integrate anthropogenic activities in surrounding areas.     

Facile splitting of hydrogen and ammonia by nucleophilic activation at a single carbon center

In possessing a lone pair of electrons and an accessible vacant orbital, singlet carbenes resemble transition metal centers and thus could potentially mimic their chemical behavior. Although singlet di(amino)carbenes are inert toward dihydrogen, it is shown that more nucleophilic and electrophilic (alkyl)(amino)carbenes can activate H2 under mild conditions, a reaction that has long been known for transition metals. However, in contrast to transition metals that act as electrophiles toward dihydrogen, these carbenes primarily behave as nucleophiles, creating a hydride-like hydrogen, which then attacks the positively polarized carbon center. This nucleophilic behavior allows these carbenes to activate NH3 as well, a difficult task for transition metals because of the formation of Lewis acid-base adducts.     

The pathophysiology of mitochondrial cell death

In the mitochondrial pathway of apoptosis, caspase activation is closely linked to mitochondrial outer membrane permeabilization (MOMP). Numerous pro-apoptotic signal-transducing molecules and pathological stimuli converge on mitochondria to induce MOMP. The local regulation and execution of MOMP involve proteins from the Bcl-2 family, mitochondrial lipids, proteins that regulate bioenergetic metabolite flux, and putative components of the permeability transition pore. MOMP is lethal because it results in the release of caspase-activating molecules and caspase-independent death effectors, metabolic failure in the mitochondria, or both. Drugs designed to suppress excessive MOMP may avoid pathological cell death, and the therapeutic induction of MOMP may restore apoptosis in cancer cells in which it is disabled. The general rules governing the pathophysiology of MOMP and controversial issues regarding its regulation are discussed.     

A surgical technique for implantation of the vibrant soundbridge middle ear implant in dogs

Objective: To report a surgical implantation of the Vibrant Soundbridge (VSB) middle ear implant in dogs. Study Design: Pilot study. Animals: Dogs (n=3). Methods: A lateral approach to the tympanic bulla was used to insert the floating mass transducer of the VSB into the tympanic bulla. Using microscopic guidance the transducer was moved to and inserted into the round window niche by manipulation through the acoustic bony meatus, after reflection of the tympanic membrane. VSB position was confirmed by computed tomography (CT) imaging. Results: No intraoperative complications occurred and CT images confirmed correct placement of the VSB. Conclusions: A VSB can be safely implanted in the middle of dogs.     

Electron spectroscopy of aqueous solution interfaces reveals surface enhancement of halides

It has been suggested that enhanced anion concentrations at the liquid/vapor interface of airborne saline droplets are important to aerosol reactions in the atmosphere. We report ionic concentrations in the surface of such solutions. Using x-ray photoelectron spectroscopy operating at near ambient pressure, we have measured the composition of the liquid/vapor interface for deliquesced samples of potassium bromide and potassium iodide. In both cases, the surface composition of the saturated solution is enhanced in the halide anion compared with the bulk of the solution. The enhancement of anion concentration is more dramatic for the larger, more polarizable iodide anion. By varying photoelectron kinetic energies, we have obtained depth profiles of the liquid/vapor interface. Our results are in good qualitative agreement with classical molecular dynamics simulations. Quantitative comparison between the experiments and the simulations indicates that the experimental results exhibit more interface enhancement than predicted theoretically.