Future investigative needs

The one element whose chemical behaviour falls within the domains of both hydrolysis and organic complexation is iron. Due to the biogeochemical significance of iron in seawater, the formation behaviour of Fe(OH) 1 and 

Fe(OH)3 can be singled out as being worthy of special emphasis in future speciation studies. 

While some elements, such as Fe, can be singled out for their special biogeo-chemical significance, the speciation of other elements can be highlighted due to an extreme paucity of quantitative assessments with respect to both speciation and distribution. Elements such as Nb, Ta, Ru, Os, Rh, Ir, Pt and Au are especially deserving of further distributional characterisations and speciation assessments. 

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Future investigation needs and stimulating research suggestions are submitted to the separation scientists community with the aim of advancing this exciting separative method and raising the level of interest in valuable and still unexplored analytical schemes. 

Complementary use, in future, of small angle solution synchrotron X-ray scattering methods with electron microscopy could contribute to the clarification of the path of the linker DNA. Thus further experiments seeking a universal model for the chromatin fibre structure need to be undertaken although the existence of such a universal structure is questionable. More importantly future investigations need to be aimed at imderstanding what relevance the structure of the fibre has to the control of DNA transcription and replication. 

Bacteria and their composites with soil minerals or organic matter are capable of taking up a wide range and variety of toxic metals in soil environments. Research done over the last decade or so has greatly improved our understanding of the mechanisms on biosorption of metals and bacte-ria-metal-soil component interactions. However, more studies from molecular level are needed in order to enhance the ability of bacteria and their association with soil components to remediate toxic metals-contaminated soils. The focus of future investigations should be on the mechanisms by which metals are sorbed and bound by bacterial cell surfaces and bacteria-soil/mineral composites. In this connection, X-ray absorption spectroscopy (XAS) is a promising technique because it can provide information about... 

Many methods are available for determining food antioxidant capacity, which is an important topic in food and nutrition research. However, there is a great need to standardize these methods because the frequent lack of an actual substrate in the procedure, the system composition, and the method of inducing oxidation could limit their accuracy. In fact, antioxidant activities in complex systems cannot be evaluated satisfactorily using a single test, and several test procedures may be required. The search for more specific assays that can be more directly related to oxidative deterioration of foods and biological systems should be the objective of future investigations. 

The most obvious future data needs concern the missing, uncertain, and conflicting data identified above. Additional experimental investigations are needed in the case of Fe(III) and Zr(IV) carbonate complexation, and in the case of the Sn(IV)/Sn(II) and the Se(0)/Se(-II) redox couples. The molecular structure of metal silicate complexes needs clarification in order to remove ambiguities in the speciation scheme of these complexes. A rather challenging topic concerns the supposed transformation of crystalline tetra-valent actinide oxides, AnOz(cr), to solids with an amorphous surface layer as soon as the An4+ ion hydrolyses. The consequences of such... 

Fundamental mechanisms of this relaxation phenomenon remain unknown and need future investigation. However, correlating the T-compensated HFR after relaxation with that after purge is of practical interest, because the initial membrane water content critically important for PEFC cold-start performance corresponds to the HFR after relaxation (during cool down), not the FIFR immediately after purge. For this reason, an empirical correlation is attempted between the HFR after purge and that after relaxation, as shown in Fig. 21. It can be seen that a reasonable correlation exists over a... 

Ideally, future investigations on the ecology of zooplankton feeding should preferably be conducted in situ, although laboratory experiments are needed to investigate the effects of potentially important signaling substances between Phaeocystis and different predators in presence of realistic alternative prey. 

While electrokinetic treatment of soils looks promising, most of the work performed was bench-scale, under carefully controlled laboratory conditions. For electrokinetic remediation to be a viable alternative for in-situ cleanup of waste sites, a number of factors will have to be investigated. All of the work to date has dealt with uniformly contaminated soil samples. Studies performed on partially saturated soils will yield different results. Further studies on the removal of mixed metal contaminated soils, using different soil types, are needed. The presence of organic compounds in the soil will also influence successful treatment of real contaminated soils. The use of reagents which could increase desorption and/or solubilization (without further contaminating the soil matrix) may also be areas of future investigation. Finally, field tests need to be performed to substantiate studies accomplished on the bench scale. 

As with many therapeutic decisions, economic cost both to the individual and to society mnst be considered. Currently, the annual cost of the new potentially disease-modifying therapies is considerable. The cost to the pharmacist of glatiramer and both currently available interferons is between 10,000 and 17,000 per patient per year. Given this expense, it must be remembered that these therapies are not curative and that individual patients may experience variable results. Future investigations evaluating these therapeutic modahties clearly will need to address not only chnical but also economic and humanistic outcomes. 

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