The functional neuroanatomy of major depression: an fMRI study using an emotional activation paradigm

An important issue regarding the neural basis of major depression is whether the functional brain changes associated with the affect disturbance seen in this syndrome are similar to those that accompany transient sadness in normal subjects. To address this question, we carried out an fMRI study using an emotional activation paradigm. Brain activity associated with passive viewing of an emotionally laden film clip aimed at inducing a transient state of sadness was contrasted with that associated with passive viewing of an emotionally neutral film clip in patients suffering from unipolar depression and in normal control subjects. Results showed that transient sadness produced significant activation in the medial and inferior prefrontal cortices, the middle temporal cortex, the cerebellum and the caudate in both depressed and normal subjects. They also revealed that passive viewing of the emotionally laden film clip produced a significantly greater activation in the left medial prefrontal cortex and in the right cingulate gyrus in depressed patients than in normal control subjects. These findings suggest that these two cortical regions might be part of a neural network implicated in the pathophysiology of major depression. Taken together, these results strongly support the view that activation paradigms represent an extremely useful and powerful way of delineating the functional anatomy of the various symptoms that characterize major depression.     

Masking-level differences in older adults: the effect of the level of the masking noise

In Experiment 1, masking-level differences (MLDs) for a 500-Hz tone at five masker levels were obtained from younger and older adults. For both age groups, there were no reliable increases in MLD once the spectrum level of the masker exceeded 27 dB SPL. MLDs were larger for younger than for older adults over the range of masker levels tested. In Experiment 2, the levels of both the signal and the masker in one ear were attenuated by either 15 or 30 dB relative to their level in the other ear, which was fixed at a spectrum level of 47 dB SPL. MLDs for both age groups declined with increasing IAA and age-related differences were observed in all conditions. The findings of these experiments indicate that (1) age-related differences in MLDs exist even when the level of the masker is sufficiently high that older adults achieve their plateau performance, and (2) older listeners are not disadvantaged more than younger listeners by interaural differences in the level of the input.     

Reliability of revealing deformation bands in an A5456 alloy by acoustic emission

The dynamics of the first deformation bands in an aluminum-magnesium A5456 alloy deformed at a constant rate of increase of stresses $\left( {\dot \sigma _0 = const} \right)$ is studied by acoustic emission and simultaneous high-speed video filming. A linear relation is found between an acoustic signal and the area of the first band during the first 20 ms of its development. Acoustic precursors are shown to be used to trigger devices with a positive or negative feedback to amplify or suppress deformation jumps, respectively.     

Facilitation and inhibition of the acoustic startle reflex in the rat after a momentary increase in background noise level

Small increments in background noise were shown to increase the amplitude of a subsequently elicited acoustic startle reflex (ASR) in rats by as much as 100% under optimal conditions. Increment lead time (5-160 ms) and level (1.5-15 dB), initial noise level (30-70 dB), startle level (95-125 dB), number of test days (1-5), and drug condition (diazepam or saline ip) were varied in 6 experiments. Prepulse facilitation (PPF), measured by difference scores, was greatest for intermediate increments (3 dB) and lead times (20-40 ms) and was replaced by prepulse inhibition (PPI) for higher values, especially in the later test days. Diazepam reduced baseline ASR and diminished PPI, but it did not affect PPF. These data argue against hypotheses that attribute PPF of this sort to either temporal integration within the ASR pathways or to the elicitation of a nonspecific arousal reaction by the prepulse.     

The use of active noise control (ANC) to reduce acoustic noise generated during MRI scanning: some initial results

The search of reprolysin inhibitors offers the possibility of intervention against both matrixins and ADAMs. Here we report the crystal structure of the complex between adamalysin II, a member of the reprolysin family, and a phosphonate inhibitor modeled on an endogenous venom tripeptide. The inhibitor occupies the primed region of the cleavage site adopting a retro-binding mode. The phosphonate group ligates the zinc ion in an asymmetric bidentate mode and the adjacent Trp indole system partly fills the primary specificity subsite S1'. An adamalysin-based model of tumor necrosis factor-alpha-converting enzyme (TACE) reveals a smaller S1' pocket for this enzyme.     

Either a paradigm shift or no mental measurement: the nonscience and the nonsense of The Bell Curve

We have shown previously that intravenous infusions of insulin, known to induce glucoprivic hunger, and of insulin combined with glucose, known to induce satiety, produce in the VMH and PVN of Wistar rats monoaminergic changes that differ from those related to spontaneously occurring hunger and satiety, while the genetically obese Zucker rat is totally resistant to the behavioural effects of insulin and insulin + glucose infusions. In the present study, the impact of these infusions on VMH and PVN monoamines in obese Zucker rats was assessed using microdialysis. Monaminergic changes (increase in DOPAC and 5-HIAA and decrease in DA and 5-HT) were quite similar in obese rats to those we found in normal rats when insulin was infused. In contrast, changes in 5-HT or DA in response to insulin and glucose were quite different in the Zucker rat. Monoaminergic changes related to meals were more dramatic in the Zucker rat and so were able to reverse the background changes produced by the insulin infusion. These data confirm the idea that the effect on monoamines of spontaneously occurring hunger and satiety is different from the effect on monoamines by insulin and glucose-induced hunger and satiety. The results show disturbances of the obese Zucker rat related both to insulin and to hypothalamic monoamines that may be involved in the hyperphagia and obesity of this model.     

Startle amplitude and fear in an acoustic startle paradigm: Lesions to the brachium of the inferior colliculus or the lateral tegmental tract.

In 2 Experiments, startle amplitude and startle stimulus-induced freezing (an index of fear) were measured in an acoustic startle response (ASR) paradigm in rats. Lesions to lateral tegmental tract (LTG), a pathway medial to brachium of the inferior colllciulus (BIC), significantly decreased freezing and produced a persistent 5-fold increase in ASR amplitude compared with sham-operated controls. Lesions to BIC increased both ASR amplitude (2-fold) and freezing. Neither BIC not LTG lesions affected startle amplitude when startle was elicited by a brief footshock stimulus. Characteristics of the lesion effects were tested with manipulations of interstimulus interval, stimulus intensity, and prepulse inhibition. The data suggest (a) an ascending pathway medial to BIC that carries the fear-inducing dimensions of an acoustic stimulus and (b) a descending pathway that provides tonic inhibition of the sensory input to the ASR circuitry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A theoretical study of the effect of experimental noise on the measurement of anisotropy in diffusion imaging

Diffusion tensor imaging (DTI) is a modality known to be highly sensitive to the detrimental effects of experimental noise. Here, using Monte Carlo simulations, we compare and contrast how noise complicates the measurement of diffusion anisotropy in diffusion tensor and conventional diffusion-weighted imaging (DWI). As the signal-to-noise ratio (SNR) decreases below a value of approximately 20, the eigenvalues (lambda(i)) of the diffusion tensor D are found to diverge rapidly from their true values, with the result that the measured anisotropy can be significantly in error and isotropic structures falsely assigned a high level of anisotropy. The effect of noise on the rotationally variant indices, calculated from a conventional diffusion-weighted imaging experiment, is found to be much less insidious, because the apparent diffusion coefficients (ADCs) diverge only slowly as the signal-to-noise decreases. Thus, although rotationally variant indices almost always underestimate the true diffusion anisotropy, they show only a small susceptibility to experimental noise and hence, are preferred to their rotationally invariant counterparts when the signal-to-noise ratio is small.     

The early diagnosis of an acoustic neuroma

A study aiming to assess the clinical tolerance of a special follow-up soybean milk formula (Neo-Soyal 2) in children with cow's milk protein intolerance or allergy (CMPI/CMPA) has been conducted in 17 infants and children (9 girls and 8 boys) aged from 6 months to 3 years. All the patients had a past history suggestive of CMPI/CMPA and were fed a restricted hypoallergenic diet with a semi-elemental formula based on protein hydrolysates. At the time of initiation of the study, all the patients were asymptomatic with normal growth while on a semi-elemental diet. The formula with protein hydrolysates was substituted by the test milk (Neo-Soyal 2) and blood samples were taken before and after 2 months. The clinical tolerance to the follow-up soybean formula was considered excellent in 16 children who remained asymptomatic with normal growth velocity. Only one patient developed a severe diarrhoea within 72 hours after introduction of the soybean formula which was stopped. However, after one month he was able to tolerate a certain amount of the soybean milk (240 ml) without symptoms. For all the patients studied, there was no change in the nutritional parameters measured in the blood before and after 2 months of the trial. Likewise, the plasma amino acid levels determined in 2 patients remained unchanged before and after the experimental period. These data indicate that the soybean milk formula used here (Neo-Soyal 2) can be safely given as a substitute of semi-elemental diets during the follow-up of children with CMPI/CMPA after the age of 6 months.     

The effect of indefinite pretrial incarceration on the anxiety level of an urban jail population

This study investigated the effect of indefinite incarceration on the anxiety levels of males (N = 60) held in a large metropolitan county jail. The IPAT Anxiety Scale Questionnaire (Self Analysis Form) was administered to 60 male Ss (18 to 26 years of age) at intervals of 1 weeks and 8 weeks after incarceration. An analysis of variance, one-way with repeated measures, on the matching IPAT Anxiety Scale scores revealed a highly significant increase in anxiety (p less than .001) from 1 week to 8 weeks. A Newman-Keuls posttest comparison also indicated that anxiety levels rose significantly (p less than .001). The results suggested that indefinite pretrail incarceration can increase anxiety to a level of psychological morbidity. The possible effect of this finding upon the guarantee of a right to speedy trial was discussed.     

The effect of the lower stress level on the cyclic creep behavior of an ods superalloy

Cyclic creep and stress rupture results are reported and discussed as a function of the lower applied load for INCONEL MA6000, which is a mechanically alloyed oxide dispersion strengthened (ODS) and γ’ precipitation strengthened nickel-base superalloy. In prior work, very large decreases in the effective minimum cyclic creep rate, based on time at maximum load, were found to occur for cyclic creep testing using a lower load near zero. The present results show that this decrease in creep rate depends on the value of the lower load. As the lower load increases, the cyclic creep rate increases proportionally, but remains less than the corresponding static creep rate. The values of the cyclic creep rates are shown to be related to the magnitude of the anelastic strain recovery occurring during the lower load portion of the cyclic creep test. The results are also used to improve on the anelastic relaxation model for cyclic creep of materials with strong pinning points.     

The effect of the lower stress level on the cyclic creep behavior of an ods superalloy

Cyclic creep and stress rupture results are reported and discussed as a function of the lower applied load for INCONEL MA6000, which is a mechanically alloyed oxide dispersion strengthened (ODS) and γ’ precipitation strengthened nickel-base superalloy. In prior work, very large decreases in the effective minimum cyclic creep rate, based on time at maximum load, were found to occur for cyclic creep testing using a lower load near zero. The present results show that this decrease in creep rate depends on the value of the lower load. As the lower load increases, the cyclic creep rate increases proportionally, but remains less than the corresponding static creep rate. The values of the cyclic creep rates are shown to be related to the magnitude of the anelastic strain recovery occurring during the lower load portion of the cyclic creep test. The results are also used to improve on the anelastic relaxation model for cyclic creep of materials with strong pinning points. INCONEL is a trademark of the INCO family of companies formerly Associate Research Scientist with Columbia University     

The effect of the lower stress level on the cyclic creep behavior of an ods superalloy

Metallurgical and Materials Transactions A - Cyclic creep and stress rupture results are reported and discussed as a function of the lower applied load for INCONEL MA6000, which is a mechanically...     

The liberating effect on the analyst of the paradigm shift in psychoanalysis.

Discusses a paradigm shift in psychoanalysis. This new paradigm is reflected in dyadic systems perspective, relational theorizing, social constructivism, and intersubjectivity theory. The author illustrates the shift's impact upon psychoanalysis with the effects of intersubjectivity theory upon his own practice. From the intersubjective perspective, there are (1) few metapsychological assumptions, (2) no assumptions of core universal conflicts, (3) a liberation of the analyst's feelings in ways that facilitate therapy, (4) a susceptibility to different errors than those of other theories, and (5) a nonadversarial approach to resistance. These 5 ideas are elaborated and illuminated by a selective use of the literature and clinical vignettes. Finally, a personal addendum describes the author's painful conflict in moving from a traditional to a constructivist stance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Helix rigidity of DNA: the meroduplex as an experimental paradigm

The intrinsic rigidity of the DNA helix is generally believed to arise primarily from vertical base-stacking interactions; however, relatively little experimental information exists regarding the relationship between the thermodynamic stability of base-stacking interactions and the mechanical rigidity imparted by such interactions. To address this issue, the solution conformations of complexes formed between adenine (A) or N-6-methyladenine (meA) monomer and deoxythymidylate (dTn) polymers of varying length (n = 40, 60, 81, and 110) have been examined. Such complexes are known to exist as extended, chiral structures in which the purine monomers exist as extensively stacked arrays. Thus, one can in principle examine the structural consequences of base-pair stack formation in the absence of any change in stoichiometric (phosphate) charge. The current approach has utilized the method of transient electric birefringence (TEB), which is highly sensitive to changes in nucleic acid conformation. Addition of millimolar concentrations of either A or meA to the dTn species leads to the formation of relatively rigid, chiral complexes whose dimensions are strictly limited by the length of the polymer strand. For adenine, the principal species appears to be [A] approximately n/2-dTn in which the polymer strand doubles back to form the two continuous strands of the complex (merotriplex). The addition of a methyl group to the N-6 position of adenine (meA) results in a shift to a meroduplex form, [meA] approximately n-dTn, with an intrinsic rigidity that is nearly identical to the rigidity of the corresponding duplex, dAn-dTn, despite the fact that the stoichiometric charge of the meroduplex is only one-half of that of the full duplex. The current results thus support a model in which helix rigidity is primarily due to the intrinsic resistance to deformation of base-stacking interactions; the deformation energies, as with the stacking energies themselves, are expected to be quite sequence-dependent. Phosphate-phosphate (repulsive) interactions, whose contributions are both salt-dependent and relatively sequence-independent, appear to play a secondary role in establishing helix rigidity. In particular, the DNA helix is likely to possess substantial rigidity in the absence of phosphate interactions. Thus, proteins whose interactions with DNA lead to substantial bending of the helix axis may facilitate such distortions through solvation of bases in addition to partial charge neutralization.     

The measurement of psychological androgyny: an extended replication

The Bem Sex-Role Inventory (BSRI), the recently developed measure for psychological androgyny, was administered to 344 middle-Tennessee high school and university students. The BSRS's reliability coefficients and mean scores were very similar to those reported earlier for California junior college and university students, respectively. The present scoring patterns for the BSRI remained unchanged with the introduction of the four "familial context" variables of sex of Ss' siblings, sex of Ss' nearest-in-age sibling, parent whom the Ss considered emotionally warmest, and parent whom the Ss would most prefer to be like. Contrary to Bem's original findings, the present results with the BSRI suggested that Ss' responses to the measure may be affected by the social desirability phenomenon. Moreover, scores on the BSRI did not correlate consistently or highly with those presently obtained with a symbolic sex-role measure and a verbal sex-role scale. This lack of construct validity has been reported previously in at least two other studies. Though apparently reliable, the validity of the BSI remains problematic.