A process for the separation of 177Lu from neutron irradiated 176Yb targets.

A conceptual flowsheet has been developed for the separation of (177)Lu from a 300 mg neutron irradiated (176)Yb enriched target. The key component of the process is an extraction chromatographic (EXC) resin containing 2-ethylhexyl 2-ethylhexylphosphonic acid (HEH[EHP]) sorbed onto a 25-53 microm Amberchrom CG-71 substrate. The process is divided into three sections: (1) front-end target removal system, (2) primary separation system and (3) secondary separation system. Each section involves the separation of Yb and Lu using the HEH[EHP] resin followed by concentration and acid adjustment of the Lu-rich eluate using an EXC material containing a diglycolamide extractant. The use of the diglycolamide EXC material is a significant feature of the flowsheet, allowing one to avoid lengthy evaporations and acidity adjustments between successive HEH[EHP] column runs while removing adventitious impurities from the (177)Lu. The overall recovery of (177)Lu is estimated at 73% with an overall decontamination factor from Yb of 10(6). The overall processing time can be as short as 4h.

Describing behavioral states using a system model of the primate brain.

A system model of the primate neocortex is presented, based mainly on the neuroanatomy of the rhesus macaque monkey and consisting of a set of processing modules arranged as a perception-action hierarchy. These modules correspond to regions of the neocortex and their connectivity to that of the neocortex. A computational approach based on predicate logic is explained, and the results of a computer implementation of the model are reported, which demonstrate social behaviors involving affiliation and social conflict. The behavioral states of primates involved in these behaviors can be represented by the states of the system model, which have a logical representation and a diagrammatic form. It is shown how the behavioral states in goal-directed behaviors can be represented and also their short term moment-to-moment development in time. It is then shown how the state of social interaction among two or more primates can be represented, using their individual behavioral states, with interindividual action and perception. The causal dynamics of behavioral states is explained and also a control mechanism, namely, the use of confirmation signals, which stabilizes behavioral states and their dynamics. Stabilized behavioral states are seen as corresponding to coherent activations of the system, resulting from successful selection of module activations and intermodule communication with confirmation.

Metal ion separations in polyethylene glycol-based aqueous biphasic systems: correlation of partitioning behavior with available thermodynamic hydration data.

Solvent extraction utilizing an oil-water mixture (e.g., chloroform-water) and a suitable complexant, is a proven technology for the selective removal and recovery of metal ions from aqueous solutions. Aqueous biphasic systems (ABS), formed by mixing certain inorganic salts and water-soluble polymers, or by mixing two dissimilar water-soluble polymers, have been studied for more than 40 years for the gentle, non-denaturing separation of fragile biomolecules, yet ABS have been virtually ignored as a possible extraction technology for metal ions. In this report we review our metal ion partitioning work and discuss the three major types of partitioning: (1) those rare instances that the metal ion species present in a given solution partitions to the PEG-rich phase without an extractant; (2) the use of halide salts which produce a metal anion complex that partitions to the PEG-rich phase; and (3) the use of a water-soluble extractant which distributes to the PEG-rich phase. In addition, we correlate the partitioning behavior we observed with available thermodynamic data for metal ions and their complexes.

Virginia Woolf and Leslie Stephen: a father's contribution to psychosis and genius.

Leslie Stephen, the father of Virginia Woolf, was a cacophony of contradictions. From all accounts, he was a bully, a manipulator, and a blustering, pessimistic, emotionally dishonest man. Although he could be lovable, charming, whimsical, encouraging, and deeply devoted to his family, he subjugated the adult women in his household and at least one son to exploitation and abuse, demanding (and receiving from his wife and step-daughter) almost total abnegation of self. Julia Stephen, in contrast, was an optimistic, seemingly selfless person, who characteristically presented herself in an "up" mood to the world. Virginia incorporated both parental moods into her character structure, as have a number of the author's cyclothymic patients. Therefore, it is postulated that pessimism and habitual deflating affronts on the part of one parent, in combination with a compulsive "good mood" on the part of the second parent, are a particularly lethal combination of character traits, which in their offspring may contribute to the rapid mood shifting characteristic of manic depression. In contrast to Julie, Stephen was a presence who could not be side-stepped. This combination of sweet and monstrous attributes in her father's nature, and again in the contrasting temperaments of the parental couple, must have been impossible to integrate for the small Virginia, who already was desperately engaged in the struggle for selfhood. She could not complete her development on the oedipal level, although she loved her father dearly, because identification with her mother meant further threat to an identity already weakened at the separation-individuation phase of development. Virginia's solution was to identify with her father in his character, his sexual identity, and his profession. Stephen, who was particularly devoted to Virginia, whom he regarded as an extension of himself, encouraged this identification, and served as her teacher and mentor. In that sense, he truly was the captain of the ship in her voyage To the Lighthouse, master of the currents that swept her onward to the grand light of her genius. A four-fold comparison of Virginia Woolf and Leslie Stephen is made concerning their respective ages of weaning, success in navigating both the rapproachment phase of separation-individuation and the oedipal period, and the ages at which their mothers died. It appears that Virginia lost her mother at those four critical periods when Leslie did not.(ABSTRACT TRUNCATED AT 400 WORDS)

Virginia Woolf: manic-depressive psychosis and genius. An illustration of separation-individuation theory.

Virginia Stephen was a member of one of England's great literary families, many of whom were also mentally ill. An exquisitely endowed infant, she was beautifully matched with her mother during the symbiotic state of development, and later called this period "the base upon which life stands." Difficulties presumably began as early as the differentiation subphase of separation. Mrs. Stephen appeared to be a narcissistic woman, who required constant affirmation, and thus was unable to respond to the needs of a developing child. Virginia probably was rescued from engulfment by a powerful biologically determined practicing period of separation-individuation. This great organismic surge, in all likelihood, is as characteristic of toddlers who are incipient manics as of children of future genius. Because of the strong regressive pull, it is probable that Virginia experienced a particularly high-powered glee in evading the field of her mother. This "economic condition," according to Freud, is a given that is felt by the manic as he overthrows the imprisoning restraints of the superego. Deflated by events beyond her control, such as the sadism of her siblings, Virginia probably attempted to return to her mother. But it appears that Mrs. Stephen was not available. Hence Virginia was forced to split off her anger and turn it against herself, keeping her aggression unavailable for neutralization. As a result she was unable to proceed to an age-adequate level of development. The raw rage lay smoldering within until many years later, when it burst forth to power her manic attacks. This failure of rapprochement presumably deflated Virginia, and resulted in a basic mood of depression already apparent in the nursery. Virginia also experienced a second basic mood, elation, which appears to have been characteristic of her even in well periods, and resembles the description of the typical manic victim given by Beck.