Prop Research Articles

An editorial reflection

A note of encouragement to those hesitant or waiting to write for our journal, together with a guide to some of the ‘props’ of the trade.

Formal Verification and Diagnosis of Combinational Circuit Designs with Propositional Logic

Zero-defect is extremely important for VLSI designs. Formal techniques for verifying the correctness of logic designs overcome the limits of test case simulation. Many formal systems have been prop...

6. Perceived sweetness in sweetener-NaCl-gum systems and its relationship to prop sensitivity

6. Perceived sweetness in sweetener-NaCl-gum systems and its relationship to prop sensitivity

Pics, Props, and Politics: A Reply to Murray and Smith

Pics, Props, and Politics: A Reply to Murray and Smith

A Metabolic Enzyme That Rapidly Produces Superoxide, Fumarate Reductase of Escherichia coli

Aerobic organisms synthesize superoxide dismutases in order to escape injury from endogenous superoxide. An earlier study of Escherichia coli indicated that intracellular superoxide is formed primarily by autoxidation of components of the respiratory chain. In order to identify those components, inverted respiratory vesicles were incubated with five respiratory substrates. In most cases, essentially all of the superoxide was formed through autoxidation of fumarate reductase, despite the paucity of this anaerobic terminal oxidase in the aerobic cells from which the vesicles were prepared. In contrast, most dehydrogenases, the respiratory quinones, and the cytochrome oxidases did not produce any detectable superoxide. The propensity of fumarate reductase to generate superoxide could conceivably deluge cells with superoxide when anaerobic cells, which contain abundant fumarate reductase, enter an aerobic habitat. In fact, deletion or overexpression of the frd structural genes improved and retarded, respectively, the outgrowth of superoxide dismutase-attenuated cells when they were abruptly aerated, suggesting that fumarate reductase is a major source of superoxide in vivo. Steric inhibitors that bind adjacent to the flavin completely blocked superoxide production, indicating that the flavin, rather than an iron-sulfur cluster, is the direct electron donor to oxygen. Since the turnover numbers for superoxide formation by other flavoenzymes are orders of magnitude lower than that of fumarate reductase (1600 min-1), additional steric or electronic factors must accelerate its autoxidation.

"The Props of My Affections"

"The Props of My Affections"

Entering Academic Psychiatry: A Resident's Perspective

University-basedpsychiatryresidencyprograms encourage thepursuit qfacademic careers, both on admission, byfiworing applicants with evidence qf a commitment to investigation, and afler residency training, by selecting asfa culty residents who have demonstrated academic and research productivity. While attempting to achieve multiple goals, some residents may be discouraged to pursue an academic career as a result of marked conflict between the clinical and academic components oftraining. The substantial diffirences in priorities among psychiatry residents ought to be explored early in residency training by devoting seminars to career planning and by facili tating the pursuit qf academic activities under a preceptorship program. Furthermore, the option fo r research track residencyprograms should be available to those with a strong commitment to academic psychiatry. In th e past 15 yea rs medi cal ed uca tors and research ers havc been incrcasin gly conce rne d abou t th e future of academic medi cin e ( 1-9) . Su ch conce rn stems from various threats to th e academic medi cal es tablishmen t, including fina ncial const raints (I 0) , litigation issu es (II) , insufficient funds to suppo r t research ( 12, 13), a nd a decline of interest by medi cal students and resid ents to pu rsu e a clini cal resea rch academic ca reer (I,3,9,14,15) . The trend towards fewer ph ysician-investigators has been identified in th e U.S. a nd worldwide (16). Wyngaarden (I) addressed th e declining interest in biom edi cal research on th c part of young physicians. He pointed out that ph ysician-investigat or s a re an enda nge re d species , basing this s ta te me n t on th e substantial declin e of th e pr op ort ion of fed eral postdoctoral fellowships awarded to M.Do's (physician-scientist s) com pare d with those granted to Ph.Dv's (non-physicians biomedi cal scie nt ists ), fro m 46% in 1977 to 20% in 1986. By 1977, of 2800 postdoctoral fellowships in th e clini cal sciences, only 2304 were filled, and 500 positions were not used. The pr oportion of federa l research grants awarded to principal investigators who are physician-scientist s also declined , from 43% in 1966 to 32% in 1977. A more recent article in th e American Journal ofMedicine com pa res academic physi cians to din osaurs, st ruggling to survive (17) . In the 80's fed eral research support to M .D o's con t inue d to decline; by 1987 68% of all NIH grants were awarded to investigators with a Ph .D. Strong recommendations to correc t th e decline in number of those en te r ing clinical investigation have been mad e, including eco no mic incentives and reexa mina-

Evaluation and Treatment of Demented Elderly

There are curre nt ly 27 mill ion people over 65 in the United States and this number will double in th e next 50 years . This will confro n t psychiatrists and ot her physician s with th e ca re of m any elderly pat ients with dementia. T hese pa tien ts will ofte n require hospi tali za tion whe n ill becau se the ir mental, physica l, a nd social func t ioning tends to break down a t once, overwhe lming fami lies and outpatient ph ysician s. Once hospitali zed, th ey require acc ura te di agnoses, multidisciplinary ca re, and planning for rehabi litation from th e on set of th e hospi tali zat ion . However, dementia is ofte n undiagn osed a nd untreated in universi ty hospi tal s as well as in prima ry ca re clinics a nd nursin g homes. The conse q ue nces of th is are limi ted pr osp ect s for clinica l improvement a nd th e likelihood of fur ther decline. Dr. Ros enberg's con t r ibu t ion to th e Jdftrson J ournal ofPsychiatry, Psychi atric Cons ulta t ion for th e Demented Eld erly eloq ue n t ly describ es t he d ilemmas of ca ring for elde rly dement ed patients in ge ne ral hospital se tt ings. It is notable th at the psychi atric consultants' initial advice to prescri be a high -poten cy neu rol eptic along with an antich olin ergic agen t is pot entially problematic becau se of demented pa ti ents propen sit y to develop ext rapyramidal side effec ts a nd deli riu m from th ese agents , respectively. Usin g a benzodiazipine is equally pr obl ematic because it may incr ease cog nitive impai rment a nd th e risk of fall s. These com plica t ions con t r ibu te to th e se nse th at gene ra l hospi tal wards are inappropriate places to ca re for demented patients. In stead , such patient s may fare bett er on dedicated ge ria t r ic psychi at ry/medi cal units wh ere the mi lieu and approach es to ca re are design ed to suppo r t impaired pat ients, com pe nsa te for th eir deficit s, a nd st im ula te th eir remaining ca pa bilit ies to ac h ieve th eir high est level of fun ct ion. Care on th e unit sho uld be ca r r ied ou t by a multidisciplina ry tea m under th e direct ion of a ge ria tric psychi atrist. The team sho uld cons ist of geriat ricians, and ge ro n to logica lly-t ra ine d nurses, social workers, a nd occupa tio na l a nd recr eational th erapists. Dr. Rosenberg's case report illu strates th e variet y of dan gers of a n inappropriate placement. Ph ysicians a re angry, nurses a re frus t ra ted , the ward is

A hybrid Isoetes, I. × harveyi, in northeastern North America

Fifty-five Isoetes plants from 11 localities were uniformly 2n = 77. These plants were referable to I. harveyi A. A. Eaton, and exhibited hybrid vigour. SEM of spores of the type and other collections had polymorphic spores and exhibited a morphology that ranged from I. macrospora to I. tuckermanii, the putative parents. This common hybrid should be named I. ×harveyi A. A. Eaton pro sp. Key words: Isoetes, hybrid, cytology, SEM.

Metal ion dependence of phosphorothioate ATP analogs in the Bacillus stearothermophilus tyrosyl-tRNA synthetase

Pre-steady-state kinetic analyses on the formation of tyrosyl adenylate from tyrosine and each of the four diastereomers of alpha- and beta-phosphorothioate adenosine triphosphates [ATP alpha S and ATP beta S; Eckstein, F., & Goody, R. (1976) Biochemistry 15, 1685-1691; Yee, D., Armstrong, V. W., & Eckstein, F. (1979) Biochemistry 18, 4116-4123] were performed in the presence of Mg2+, Co2+, and Cd2+ as the divalent metal ion cofactor. A modest preference of 5.5-fold in kappa 3/KA' (where kappa 3 is the rate constant for tyrosyl adenylate formation and KA' is the dissociation constant for ATP, or phosphorothioate ATP, from the E.Tyr.metal.ATP complex) for the Sp ATP alpha S diastereomer and the absence of an inversion of preference when the metal ion is changed suggest that there is a stereospecific enzyme-alpha-phosphate interaction and that there is no direct metal ion interaction with the alpha-phosphate. The extent of reaction of the ATP alpha S diastereomers (30-50%) implies that these analogues are more susceptible to the hydrolytic site reaction previously reported for this enzyme [Wells, T. N. C., & Fersht, A. R. (1986) Biochemistry 25, 1881-1886]. The strong preference in kappa 3/KA' for the RP ATP beta S diastereomer (16-fold for Mg2+ and 50-fold for Co2+) is indicative of a stereospecific interaction with the pro SP beta oxygen of ATP.(ABSTRACT TRUNCATED AT 250 WORDS)

William Leslie, Henry Howard and Lord Arlington 1666–67

In a previous article in Recusant History (Jan. 1958), passing reference was made to two substantial documents by William Leslie (about 20,000 words in all) in Public Record Office: ‘A Relation of the Cardinals of the Court of Rome’ and ‘Concerning the affairs of Rome in relation to England’ (PRO SP 9/203/7, 8 and 9). They are part of the archives of Henry Bennet, Lord Arlington, Secretary of State 1662-74, and have been endorsed by Arlington's secretary, Joseph Williamson, in the form: ‘This was a copy of a paper written to Mr Henry Howard of Norfolk 1667 by one Leslie, a Scottish priest at Rome, and by him for his own discharge communicated to my Lord Arlington, with renunciation of all such correspondences for the future.’

A new Isoetes hybrid (Isoetes echinospora × riparia) for Canada

A new interspecific hybrid in Isoetes, Isoetes echinospora Dur. × Isoetes riparia Engelm., is delineated by means of cytology and scanning electron microscopy of spores from the Ottawa–Hull district of Canada. The hybrid should be known as I. × dodgei A. A. Eaton pro sp. This triploid hybrid (2n = 33) exhibits polymorphic megaspores and hybrid vigour. The megaspores of some of the hybrids are extremely spiny, with many fused and irregular spines resulting in convoluted and distorted surfaces. Distribution maps for three species, I. echinospora, I. riparia, and I. macrospora Dur., as well as one hybrid, I. × dodgei, are presented for the Ottawa district.

On 64%-Majority Rule

Introduction d'une definition de consensus social base sur deux restrictions: une sur les preferences individuelles et l'autre sur la distribution des preferences. Dans ce cas de consensus, une regle de majorite a 64% presente de nombreuses proprietes interessantes par opposition aux regles de super-majorite possedant des proprietes paradoxales comme les regles electorales americaines

WATER STRUCTURE IN DESPENTAPEPTIDE (B26—B30) INSULIN CRYSTAL AT 1.5 RESOLUTION

The water structure in despentapeptide (B26-B30) insulin crystal is presented in this paper. Ac- cording to inspection of the final F_0-extended (2F_0-F_c) Fourier map, 81 water molecules (about two thirds of solvent) with electron density greater tLan 0.4 e/A~3 are included in the water model to be discussed. In a hydrogen bond length range of 2.4--3.2 A, 51 water molecules, that is, 63% of the total 81, are hydrogen bonded to protein, of which 12 link the adjacent protein molecules through one- water bridges and more through two-water bridges. There is a tight water network in a long crevice be- tween protein molecules; two Cd atoms, like two piles, prop up the network through three water molecules (Cd ligands) at either end of the network, indicating that Cd ions and water networks play an important role in close packing of protein molecules in the crystal.

Tool company moves into 'prop' manufacturing

Tool company moves into 'prop' manufacturing

Tool company moves into ‘prop’ manufacturing

Tool company moves into ‘prop’ manufacturing

Assessing the stability of a propped, insitu retaining wall in overconsolidated clay : Symons, I F Inst Civ Engr ProcV75, Part 2, Dec 1983, P617–633

Assessing the stability of a propped, insitu retaining wall in overconsolidated clay : Symons, I F Inst Civ Engr ProcV75, Part 2, Dec 1983, P617–633

"The Props of My Affections": A Note on "The Prelude" II, 276-281

"The Props of My Affections": A Note on "The Prelude" II, 276-281

Propping across the Channel

If you cross the Channel on one of two new Seaspeed hovercraft, spare a thought for the giant propellers over your head which are speeding you over the waves to your Continental destination.

A Corollary to Lazard's Theorem on Pro-P -GROUPS

A Corollary to Lazard's Theorem on Pro-P -GROUPS