scispace - formally typeset
Search or ask a question

Showing papers by "Tufts University published in 1974"


Journal ArticleDOI
TL;DR: Considerations and techniques are proposed that reduce the complexity of programs by dividing them into functional modules, which can make it possible to create complex systems from simple, independent, reusable modules.
Abstract: Considerations and techniques are proposed that reduce the complexity of programs by dividing them into functional modules. This can make it possible to create complex systems from simple, independent, reusable modules. Debugging and modifying programs, reconfiguring I/O devices, and managing large programing projects can all be greatly simplified. And, as the module library grows, increasingly sophisticated programs can be implemented using less and less new code.

1,138 citations


Journal ArticleDOI
TL;DR: A combined Golgi‐Nissl approach provides a scheme in which neuronal types, defined in terms of a number of functionally significant features, can be precisely localized within the cochlear nucleus of the cat.
Abstract: A detailed parcellation of the entire cochlear nucleus of the cat was prepared with the Nissl and Protargol methods in the form of a cytoarchitectonic atlas. Neuronal cell types were characterized in rapid Golgi impregnations. Golgi impregnations were used to define the specific features of the mature neuronal types. Neurons from the Golgi preparations were systematically mapped according to type and location in serial sections. These neurons were then plotted in corresponding positions in the cytoarchitectonic atlas. This combined Golgi-Nissl approach provides a scheme in which neuronal types, defined in terms of a number of functionally significant features, can be precisely localized within the cochlear nucleus.

482 citations


Journal ArticleDOI
TL;DR: This review deals primarily with analytical and preparative isoelectric focusing (IEF) in gel media and reports the analysis of glycoproteins, immunoglobulins, lipoprotein, membrane proteins, peptides and metalloproteins to the study of biological systems.

380 citations


Journal ArticleDOI
TL;DR: The differences in serum cholesterol and uric acid levels, and in intrapopulation trends of blood pressure in relation to age between the more and less acculturated groups were found to correlate best with dietary differences, especially in intake of salt, and of tinned meat and fish.
Abstract: Cardiovascular risk factors have been analyzed as part of a combined ethnographic, anthropometric, and medical study of 1390 adult subjects in defined populations representing six Solomon Islands Societies. The six societies, all at low levels of acculturation, differed in habitat, way of life, and exposure to Western civilization. Criteria for ranking the societies in respect to acculturation were developed based on demographic changes within defined populations, secular increase in adult height, length and intensity of contact with Western cultural influences, religious belief, education, availability of medical care, economy, and diet. The six tribal groups were ranked by these criteria as follows: (1) Nasioi, (2) Nagovisi, (3) Lau, (4) Baegu, (5) Aita, (6) Kwaio. Physical health and nutrition were good in all six groups, and clinical evidence of coronary heart disease and atherosclerosis was absent. Serum cholesterol levels were higher at almost all ages and both sexes in the three more acculturated t...

369 citations


Journal ArticleDOI
TL;DR: Daughters were significantly more likely than sons to be described as little, beautiful, pretty, and cute, and as resembling their mothers, suggesting that sex-typing and sex-role socialization have already begun at birth.
Abstract: Thirty pairs of primiparous parents, fifteen with sons and fifteen with daughters, were interviewed within the first 24 hours postpartum. Although male and female infants did not differ in birth length, weight, or Apgar scores, daughters were significantly more likely than sons to be described as little, beautiful, pretty, and cute, and as resembling their mothers. Fathers made more extreme and stereotyped rating judgments of their newborns than did mothers. Findings suggest that sex-typing and sex-role socialization have already begun at birth.

326 citations



Journal ArticleDOI

222 citations


Journal ArticleDOI
TL;DR: Large discrepancies were found in almost all categories of comparisons in the same 253 cases that had been examined by six independent examiners previously.

220 citations


Journal ArticleDOI
30 Aug 1974-Science
TL;DR: Rats trained on 16 two-odor discrimination problems showed rapid acquisition of a learning set and one-trial learning by the end of the problem series, and learning-set performance of rats trained with odor stimulus comparable to that reported for primates trained on visual cues.
Abstract: Rats trained on 16 two-odor discrimination problems showed rapid acquisition of a learning set and one-trial learning by the end of the problem series. Learning to sample odor cues before responding and adoption of a "win-stay, lose-shift" strategy probably accounts for the virtually errorless learning. Learning-set performance of rats trained with odor stimulus comparable to that reported for primates trained on visual cues.

197 citations


Journal ArticleDOI
25 Oct 1974-Science
TL;DR: The findings with leukocytes support the suggestion that singlet excited oxygen acts as one of the mediators of their bactericidal action.
Abstract: Human polymorphonuclear leukocytes kill a colorless mutant strain of Sarcina lutea much more readily than a carotenoid-containing strain. A similar protective effect has been reported in the organism during photodynamic inactivation, where it is attributable to the quenchintg of singlet excited oxygen by carotenoids. The findings with leukocytes support the suggestion that singlet excited oxygen acts as one of the mediators of their bactericidal action.

181 citations


Journal ArticleDOI
TL;DR: A new synthesis of an R-factor-specific protein occurs in E. coli minicells containing tetracycline-resistant R factors when they are incubated in the presence of tetrACYcline.

Journal ArticleDOI
TL;DR: The prominence of the C-cell population and increased tissue calcitonin content in the normal adult thyroid gland and in the neonate is similar to that observed in the adult.
Abstract: C-cells have been mapped in the thyroid glands of 6 human neonates by means of immunoperoxidase localization of calcitonin and tissue calcitonin content as measured by radioimmunoassay. The C-cells were concentrated in a zone in the upper two-thirds of the lateral lobes bilaterally, where they were identified individually and in small groups in both an intrafollicular and parafollicular distribution. In contrast to findings in the adult, C-cells were predominantly intrafollicular in the neonate. The relative numbers of C-cells counted per unit area of thyroid tissue correlated strongly with the calcitonin content of immediately adjacent tissue sections. In areas rich in C-cells, as many as 75 immunoperoxidase-stained cells per low-power field were counted, and the concentration of calcitonin was as high as 540 to 2100 mU/g fresh weight, values that were as great as 10 times those observed in the normal adult thyroid gland. The prominence of the C-cell population and increased tissue calcitonin content in the human neonatal thyroid gland may reflect an as yet undefined physiologic role for calcitonin in the newborn.

Journal ArticleDOI
TL;DR: Inhibition obtained with diHydropteroylhexaglutamate and dihydropteroysltriglutamate is sufficient to warrant consideration of these compounds as physiological regulators of thymidylate formation.

Journal ArticleDOI
TL;DR: These mutants, selected as strains resistant to rifampin or streptolydigin, demonstrate drug-resistant in vitro ribonucleic acid synthesis and sporeforming ability and support of phage infection are altered in many of the mutants.
Abstract: Mutants of Bacillus subtilis with altered deoxyribonucleic-dependent ribonucleic acid polymerase activity have been isolated and characterized. These mutants, selected as strains resistant to rifampin or streptolydigin, demonstrate drug-resistant in vitro ribonucleic acid synthesis. Sporeforming ability and support of phage infection are altered in many of the mutants. Mutations to rifampin and streptolydigin resistance have been located on the B. subtilis chromosome and ordered relative to the markers cysA14 and str.

Journal ArticleDOI
01 Dec 1974-Virology
TL;DR: The hypothesis that the A exclusion system blocks entry of superinfecting phage DNA explains the observation that the P22 generalized transducing particles are excluded, and the sie A-excluded DNA is nicked, indicating that at least some of it is ejected from the phage head.

Journal ArticleDOI
02 Aug 1974-Science
TL;DR: Thirteen of 20 normal adults given 10 milligrams of dextroamphetamine exhibited paradoxical drowsiness accompanied by lowered electrical brain activity (contingent negative variation, or CNV) in the first hour post-drug while seven subjects showed behavioral alertness and increased CNV amplitude.
Abstract: Thirteen of 20 normal adults given 10 milligrams of dextroamphetamine exhibited paradoxical drowsiness accompanied by lowered electrical brain activity (contingent negative variation, or CNV) in the first hour post-drug. During this period, seven subjects showed behavioral alertness and increased CNV amplitude. Both groups of subjects showed heightened alertness 2 and 3 hours post-drug. Amphetamine is not a simple stimulant of the central nervous system but can also act as a depressant.

Journal ArticleDOI
TL;DR: It was found that the broad EPR signal, induced by light in benzene solutions of chlorophyll a and hydroquinone, and related to chlorophyLL oxidation, is efficiently quenched by P‐438 and to a much smaller extent also by Sarcina phytoene.
Abstract: — Carotenoid pigments were extracted and purified from wild-type and mutants 7 and 93a of Sarcina lutea, and tested for their ability to quench 1O2. The wild-type pigment (P-438, 9 conjugated double bonds) is as active in quenching 1O2 as is β-carotene. On the other hand, the pigment P-422 (8 conjugated double bonds) from mutant 7 is 2 or 3 times less efficient, whereas phytofluene and phytoene from S. lutea are 100 and 1000 times less efficient, respectively, than is β-carotene at quenching 1O2. It was also found that the broad EPR signal, induced by light in benzene solutions of chlorophyll a and hydroquinone, and related to chlorophyll oxidation, is efficiently quenched by P-438 and to a much smaller extent also by Sarcina phytoene.

Journal ArticleDOI
TL;DR: The nonserial problem of synthesizing an energy integrated separation system is solved by decomposing the original problem so that a serial structure results.
Abstract: The problem of synthesizing an optimal multicomponent separation system which is energy integrated is solved by a combined decomposition and dynamic programming technique. Dynamic programming is an optimization technique which allows the solution by decomposition of a multistage or serial optimization problem. Whenever the special serial structure is absent, again decomposition can be tried, but in this case it is by no means obvious how to decompose effectively the given problem into subproblems. In this paper the nonserial problem of synthesizing an energy integrated separation system is solved by decomposing the original problem so that a serial structure results.

Journal ArticleDOI
TL;DR: Among 50 patients with acute pericarditis, 48 showed classic stage 1 S-T segment deviations, stage 3 T wave inversions developed in 32 patients, and the wide dispersion of ÂT in stage 3 is consistent with inhomogeneity of the ventricular recovery process after injury.
Abstract: Among 50 patients with uncomplicated acute pericarditis, 48 showed classic stage 1 S-T segment deviations; stage 3 T wave inversions developed in 32 patients. Electrocardiographic changes during the transitional stages 2 and 4 were recorded in 23 and 32 patients, respectively. Stage 1 orientation of the S-T segment frontal plane mean vector (ÂS-T) corresponded closely to ÂT and ÂQRS. Precordial S-T segment elevations occurred with increasing frequency from leads V 1 to V 6 . Subsequent T wave inversions produced a wide dispersion of ÂT in stage 3 between −50 ° and +100 °; precordial T waves were always inverted in leads V 5 and V 6 . Forty-one patients had P-R segment shifts; in 93 percent ÂP-R was concentrated between −120 ° and −150 °, directly opposite to ÂP. ÂS-T was oriented to the left and anterior and inferior, representing the generalized subepicardial ventricular myocarditis of acute pericarditis. ÂP-R was oriented to the right and posterior and superior, representing the corresponding generalized atrial injury. The wide dispersion of ÂT in stage 3 is consistent with inhomogeneity of the ventricular recovery process after injury.

Journal ArticleDOI
TL;DR: The amino acid composition of the polypeptide isolated from the crude insoluble copper protein is strikingly similar to that of metallothionein, suggesting that the neonatal protein represents a copper-rich form of metAllothione in a distinct population of heavy lysosomes.

Journal ArticleDOI
TL;DR: Levels of ampicillin in fibrin loci were strikingly higher when the drug was injected intermittently than when the same total dose was given by continuous infusion, due to the higher peak levels attained in serum with the intermittent approach.
Abstract: methods of administration, levels of antibiotic in sc fibrin clots rose progressively until they were similar to peak concentrations of free drug in serum. Levels of ampicillin in these fibrin loci were strikingly higher when the drug was injected intermittently than when the same total dose was given by continuous infusion. This appeared to be due to the higher peak levels attained in serum with the intermittent approach. The concomitant administration of probenecid increased the levels of ampicillin or oxacillin in serum and fibrin clots but did not affect distribution between the two compartments.

Journal ArticleDOI
TL;DR: Fibrin clots were studied in vitro to determine the kinetics of entry and exit of two penicillins as mentioned in this paper, showing that the model in the in vivo fibrin clot may provide an accurate representation of the behavior of antibiotics in a localized area of suppuration.
Abstract: Fibrin clots were studied in vitro to determine the kinetics of entry and exit of two penicillins. The nature of the ambient bath did not affect the behavior of ampicillin. In contrast, oxacillin penetrated more slowly from serum than from Krebs-Ringer solution, and its exit from clots previously exposed to serum was similarly delayed. These phenomena may be related to protein binding of the drugs. Ampicillin was administered to rabbits by iv bolus, after which concentrations of the drug in various sites were measured. Levels in sc-implanted fibrin clots closely resembled those in abscesses, rising to a peak at 1 hr and thereafter remaining in excess of concentrations in serum. Levels approaching those in serum were rapidly achieved in "interstitial fluid" and declined at a slightly lower rate. These studies suggest that the model in the in vivo fibrin clot may provide an accurate representation of the behavior of antibiotics in a localized area of suppuration.

Journal ArticleDOI
TL;DR: Purified rat liver alkaline phosphatase appears to be a zinc-containing enzyme, loss of which results in irreversible inactivation, and loss of activity after electrodialysis can be rapidly reversed by the addition of magnesium.

Journal ArticleDOI
TL;DR: Using horseradish peroxidase as a retrograde axoplasmically transported tracer, afferents from medial pulvinar to a region of cortex within the arcuate sulcus roughly coextensive with the frontal eye fields or area 8 could be demonstrated.

Journal ArticleDOI
TL;DR: The time course of spontaneous ventricular vulnerability to fibrillation during coronary occlusion differs from that of ligature release, the former diminishing and the latter increasing with the duration of occluding, suggest different electrophysiologic mechanisms for ventricular tachyarrhythmias during and after release of coronary ligation.
Abstract: Release of left anterior descending coronary artery ligature was performed in 32 dogs after periods of ligation ranging from 3 to 45 minutes. Spontaneous ventricular tachycardia or fibrillation occurred during occlusion in 9 of 20 dogs, developing during the first 8 minutes of occlusion in 8 of the 9. Ventricular tachycardia or fibrillation was evoked by release of occlusion in 3 of 7 dogs after a short-term occlusion of 3 to 6 minutes, and in 9 of 13 dogs after release of a long-term occlusion of 15 to 45 minutes. Thresholds for induced ventricular tachycardia or fibrillation were obtained using a train of gated stimuli (100 Hz for 250 msec). During short-term occlusions, average thresholds for ventricular tachycardia or fibrillation were reduced from 32.4 ma (control) to 3.4 ma ( P Our data suggest the following conclusions: (1) The time course of spontaneous ventricular vulnerability to fibrillation during coronary occlusion differs from that of ligature release, the former diminishing and the latter increasing with the duration of occlusion. (2) This observation and the lack of correlation between thresholds of induced ventricular tachycardia or fibrillation and spontaneous vulnerability to fibrillation after ligature release suggest different electrophysiologic mechanisms for ventricular tachyarrhythmias during and after release of coronary ligation.

Journal ArticleDOI
TL;DR: In this paper, a model for granular superconductors consisting of an array of small superconducting particles interacting by Josephson coupling through insulating barriers is considered and the conditions for observing the phase-locking transition distinct from quasiordering within the grains are found.
Abstract: We consider a model for granular superconductors consisting of an array of small superconducting particles interacting by Josephson coupling through insulating barriers. We obtain systematically the various critical regions, critical temperature shifts, and crossover regions between zero- and three-dimensional behavior as functions of measurable sample parameters. The qualitative behavior of the system in the various regimes is analyzed and results for the specific heat and fluctuation conductivity in the Gaussian region above ${T}_{c}$ are obtained. The possibility of obtaining large critical regions is emphasized. The conditions for observing the phase-locking transition distinct from quasiordering within the grains are found. Theoretical predictions are compared with existing experimental results.

Journal ArticleDOI
01 May 1974-Blood
TL;DR: Data suggest that minute amounts of H2O2, which could theoretically be generated in vivo at sites of platelet plug formation, could play a regulatory role in the dynamics of growth and/or dissipation of the hemostatic plug.

Journal ArticleDOI
TL;DR: A formal method is described for the synthesis of multicomponent distillation systems when energy integration is considered between streams both within the separation sequence and in other parts of the process.
Abstract: A formal method is described for the synthesis of multicomponent distillation systems when energy integration is considered between streams both within the separation sequence and in other parts of the process. The pressure in each column is considered as an optimization variable for both the energy integration and column sizing computations. Four rules are used to enumerate all feasible energy matches between the streams associated with the distillation columns. A bounding strategy which uses both upper and lower bounds is combined with dynamic programming to synthesize the optimal distillation sequence with energy integration. A five-component separation problem demonstrates the effectiveness of the methods.

Journal ArticleDOI
TL;DR: It appears that myeloperoxidase (MPO) can not only decarboxylate free and bound amino acids, yielding aldehydes, but also it can actively participate in oxidative peptide cleavage, which may play a critical role in the microbicidal action of the leukocyte.
Abstract: The antimicrobial activities of the myeloperoxidase-H2O2-halide system have received considerable attention recently. The precise mechanism by which this system exerts its lethal activity is presently not clear. In an effort to learn more regarding a possible mechanism of action, the susceptibility of protein-bound amino acids to enzymatic attack by myeloperoxidase (MPO) in the presence of chloride ions was investigated. [1, 7-14C]diaminopimelic acid (DAP) was incorporated into Escherichia coli W-7 proteins with little randomization of the radioactivity. Under appropriate conditions, it was observed that the MPO-H2O2-halide system released approximately 94% of the radioactivity from labeled bacteria. This would indicate that, in addition to decarboxylation, peptide bonds are also split during this reaction. The oxidative decarboxylation of DAP-labeled bacteria by MPO (i) is Cl− dependent, (ii) has an acid pH optimum, (iii) requires a specific concentration of H2O2 for activity, (iv) reaches a plateau by 25 min, and (v) is markedly inhibited by taurine. These properties are similar to those observed with free amino acids. It appears from these data that MPO can not only decarboxylate free and bound amino acids, yielding aldehydes, but also it can actively participate in oxidative peptide cleavage. Both of those activities may play a critical role in the microbicidal action of the leukocyte.

Journal ArticleDOI
01 Nov 1974-Nature
TL;DR: The results suggest that antigenic determinants related to the SP 104 virus are present on the lymphocytes of patients with SLE, and preliminary evidence linking the SP104 virus to SLE in humans is presented.
Abstract: VIRUSES have been implicated as the agents of systemic lupus erythematosus (SLE) expressed by dogs1 and mice2. We have shown that cell-free filtrates prepared from the spleens of dogs with positive LE cell tests induced anti-nuclear and anti-double-stranded DNA antibodies in CAF1 mice. The canine filtrate also induced lymphoid tumours in some recipient mice1. One of these neoplasms, SP 104, produces a monoclonal antibody against double-stranded DNA. Cultured SP 104 cells produce, in addition to the anti-DNA antibody, C-type RNA viruses that induce anti-nuclear antibodies when inoculated into normal mice (R.M.L., W.T., C.S., and R.S.S., unpublished). Here we present preliminary evidence linking the SP 104 virus to SLE in humans. Our results suggest that antigenic determinants related to the SP 104 virus are present on the lymphocytes of patients with SLE.