Target phenomenon

Histoplasma capsulatum var. duboisii causes African histoplasmosis, skin manifestations being the prominent sign in this variant. Three patterns may be differentiated clinically superficial (ulcerating papules or nodules, infiltrated plaques, target phenomenon ), subcutaneous granulomas (first hot and tender, then cold, rupture) and osteomyelitic lesions, the latter often demanding surgical procedures combined with amphotericin B and ketoconazole. 

The pharmaceutical industry has experienced this target phenomenon before. The extent of governmental authority was broadly increased... 

In spite of the considerable virtues of Strevens account of scientific explanation, this chapter makes the case that it fails to adequately capture the nature and function of explanatory idealization in chemistry. Explanatory idealization in chemistry is often a matter of distorting explanatorily relevant causal factors - the difference-makers themselves. Strevens commitment to an ontological conception of causal explanation rules out the idealization of difference-makers because they undermine the causal entailment of the target phenomenon. And in an ontological mode of explanation, it is difficult to see how idealized models in chemistry could perform a legitimate causal-explanatory function. For example, the ontological status of atomic and molecular orbitals is vexed to say the least and therefore appear to be poor candidates for causal-difference-makers in Strevens sense. 

Recently, the related phenomenon of RNA interference (RNAi) has attracted much attention [5]. RNAi occurs when a short (generally 21 nucleotides in length) double-stranded RNA (dsRNA) catalyticaUy represses the translation of a fully complementary mRNA sequence. The process appears to proceed via a complex formed between the antisense RNA strand and a protein with RNase activity [6]. Upon binding to the target mRNA sequence, the ribonucleoprotein complex initiates cleavage of the mRNA transcript thus preventing translation of intact protein. After dissociation from the truncated mRNAs, the ribonucleoprotein complex is free to act on other intact mRNAs. Such small interfering RNAs (siRNAs) have... 

The counterflow configuration has been extensively utilized to provide benchmark experimental data for the study of stretched flame phenomena and the modeling of turbulent flames through the concept of laminar flamelets. Global flame properties of a fuel/oxidizer mixture obtained using this configuration, such as laminar flame speed and extinction stretch rate, have also been widely used as target responses for the development, validation, and optimization of a detailed reaction mechanism. In particular, extinction stretch rate represents a kinetics-affected phenomenon and characterizes the interaction between a characteristic flame time and a characteristic flow time. Furthermore, the study of extinction phenomena is of fundamental and practical importance in the field of combustion, and is closely related to the areas of safety, fire suppression, and control of combustion processes. 

It may be worthwhile to compare briefly the PECD phenomenon discussed here, which relates to randomly oriented chiral molecular targets, with the likely more familiar Circular Dichroism in the Angular Distribution (CDAD) that is observed with oriented, achiral species [44 7]. Both approaches measure a photoemission circular dichroism brought about by an asymmetry in the lab frame electron angular distribution. Both phenomena arise in the electric dipole approximation and so create exceptionally large asymmetries, but these similarities are perhaps a little superficial. 

NK cells possess a receptor for Fc/and this enables them to adhere to target cells coated in antibody with the resultant destruction ofthat cell. This phenomenon is known as antibody-dependent cell-mediated cytotoxicity (ADCC). This was attributed to a separate cell population known as killer (K) cells but these have now been shown to be in effect NK cells. 

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