Gaps remaining

Dichlorvos (9.50) is an insecticide of reportedly wide use, the metabolites of which in humans include dichloroethanol and dimethyl phosphate. Like paraoxon, dichlorvos is hydrolyzed by human serum. However, the enzyme activities hydrolyzing the two substrates were shown to differ by a number of criteria [114], Clearly large gaps remain in our understanding of the human metabolism of organophosphorus insecticides and other toxins. A bacterial phosphodiesterase appears as a promising tool to understand the catalytic mechanisms of organophosphoric acid triester detoxification [115-117],... 

Though great progress has been made in the past four decades, many gaps remain in our understanding of the chemical processes that occur in the sea. There are several reasons for this. First, except for water and the six major ions, all the other substances in seawater are present at very low concentrations. The combination of trying to detect low concentrations in the presence of large amounts of salts makes measurement of the trace constituents in seawater very difficult. To make matters even more complicated, most elements are present in several different forms, or species, in seawater. The speci-ation of an element determines its reactivity. Thus, the concentration of each species of an element must be known to fully understand the chemical behavior of that element. 

Different options for getting disposal Information to the pesticide user have been tried. For example, a number of manuals were published to provide advice on specific disposal problems. These were Intended to provide "how-to" Infornetlon to the people In the field who advise and regulate pesticide users. Each made a definite contribution, but Information gaps remained. 

Although many gaps remain in our knowledge, a summary of what is known concerning core policies, strategies and interventions to promote more rational use of medicines is presented in the following sections and summarized in Table 6. 

The first 50 consecutive steps were identified. A number of gaps remained between positions 50 and 60. There are two dominant reasons for this limit decrease of yield of liberated amino acids and increase of background mate-... 

We have considered in these pages a number of clay mineral systems based upon the relative positions of clays in chemical space. These systems have further been viewed in P-T space, although briefly. The point of this exercise has not been encyclopedic but more one of method, or analysis of the problems and methods which can be used in an attempt to solve them. It is apparent that large gaps remain in the proposed analysis. I hope that the general use of common physical-chemical methods of analysis will be more systematically employed in future studies on clay minerals. 

Picatinny Test No h It uses apparatus of Perkins (Ref 32) which consists of a motor-driven prohe which moves to a set gap, remains stationary for a specified time, and then moves back to the starti ng point. The capacitance can be varied from 10" to fii, and the voltage can be varied from 1.0 to 5k volts. No humidity control is present. The schematic circuit is shown in Fig E17, which is a copy of Fig II of Ref 35, p23... 

Although the SEMS represents a marked advance in the state of the art for measurement of aerosol size distribution, an important gap remains in current measurement technology, namely, the ability to make rapid, high-resolution measurements of the accumulation-mode aerosols on-line. The limitation of the DMA or SEMS for measurement of particles larger than 0.2 xm in diameter is the multiple charging that allows particles of two or more different sizes to contribute a given mobility fraction. Regardless of... 

It is simple to see what gaps remain to be filled in and what... 

Figure 2 translates the charge carrier formation reaction into an energy level diagram for various systems. In fact these levels refer to standard chemical potentials or (in the case of the Fermi-levels ) to full chemical potentials (see e.g. Refs.3,35). As long as —in pure materials— the gap remains large compared to RT, the Boltzmann-form of the chemical potential of the respective charge carrier (defect) is valid,... 

There is now strong evidence that certain strains of LAB are endowed with the capacity to stimulate both nonspecific and specific immune functions. This highlights the opportunity for the dairy and health food industries to develop novel, valueadding, immunity-enhancing food products. However, many significant gaps remain in our knowledge. Therefore, future studies should be directed at ... 

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