Poor Ability (poor + ability)

Distribution by Scientific Domains


Selected Abstracts


The human mirror neuron system in a population with deficient self-awareness: An fMRI study in alexithymia

HUMAN BRAIN MAPPING, Issue 7 2009
Yoshiya Moriguchi
Abstract The mirror neuron system (MNS) is considered crucial for human imitation and language learning and provides the basis for the development of empathy and mentalizing. Alexithymia (ALEX), which refers to deficiencies in the self-awareness of emotional states, has been reported to be associated with poor ability in various aspects of social cognition such as mentalizing, cognitive empathy, and perspective-taking. Using functional magnetic resonance imaging (fMRI), we measured the hemodynamic signal to examine whether there are functional differences in the MNS activity between participants with ALEX (n = 16) and without ALEX (n = 13), in response to a classic MNS task (i.e., the observation of video clips depicting goal-directed hand movements). Both groups showed increased neural activity in the premotor and the parietal cortices during observation of hand actions. However, activation was greater for the ALEX group than the non-ALEX group. Furthermore, activation in the left premotor area was negatively correlated with perspective-taking ability as assessed with the interpersonal reactivity index. The signal in parietal cortices was negatively correlated with cognitive facets assessed by the stress coping inventory and positively correlated with the neuroticism scale from the NEO five factor personality scale. In addition, in the ALEX group, activation in the right superior parietal region showed a positive correlation with the severity of ALEX as measured by a structured interview. These results suggest that the stronger MNS-related neural response in individuals scoring high on ALEX is associated with their insufficient self-other differentiation. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [source]


ON FINANCE AS A THEORY OF TFP, CROSS-INDUSTRY PRODUCTIVITY DIFFERENCES, AND ECONOMIC RENTS,

INTERNATIONAL ECONOMIC REVIEW, Issue 2 2008
Andrés Erosa
We develop a theory of capital-market imperfections to study how the ability to enforce contracts affects resource allocation across entrepreneurs of different productivities, and across industries with different needs for external financing. The theory implies that countries with a poor ability to enforce contracts are characterized by the use of inefficient technologies, low aggregate TFP, large differences in labor productivity across industries, and large employment shares in industries with low productivity. These implications are supported by the empirical evidence. The theory also suggests that entrepreneurs have a vested interest in maintaining a status quo with low enforcement. [source]


Biochemical and ultrastructural alterations in the rat ventral prostate due to repetitive alcohol drinking

JOURNAL OF APPLIED TOXICOLOGY, Issue 4 2007
M. I. Díaz Gómez
Abstract Previous studies showed that cytosolic and microsomal fractions from rat ventral prostate are able to biotransform ethanol to acetaldehyde and 1-hydroxyethyl radicals via xanthine oxidase and a non P450 dependent pathway respectively. Sprague Dawley male rats were fed with a Lieber and De Carli diet containing ethanol for 28 days and compared against adequately pair-fed controls. Prostate microsomal fractions were found to exhibit CYP2E1-mediated hydroxylase activity significantly lower than in the liver and it was induced by repetitive ethanol drinking. Ethanol drinking led to an increased susceptibility of prostatic lipids to oxidation, as detected by t-butylhydroperoxide-promoted chemiluminiscence emission and increased levels of lipid hydroperoxides (xylenol orange method). Ultrastructural alterations in the epithelial cells were observed. They consisted of marked condensation of chromatin around the perinuclear membrane, moderate dilatation of the endoplasmic reticulum and an increased number of epithelial cells undergoing apoptosis. The prostatic alcohol dehydrogenase activity of the stock rats was 4.84 times lower than that in the liver and aldehyde dehydrogenase activity in their microsomal, cytosolic and mitochondrial fractions was either not detectable or significantly less intense than in the liver. A single dose of ethanol led to significant acetaldehyde accumulation in the prostate. The results suggest that acetaldehyde accumulation in prostate tissue might result from both acetaldehyde produced in situ but also because of its low aldehyde dehydrogenase activity and its poor ability to metabolize acetaldehyde arriving via the blood. Acetaldehyde, 1-hydroxyethyl radical and the oxidative stress produced may lead to epithelial cell injury. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Melanin as a Target for Melanoma Chemotherapy: Pro-oxidant Effect of Oxygen and Metals on Melanoma Viability

PIGMENT CELL & MELANOMA RESEARCH, Issue 3 2003
Patrick J. Farmer
Melanoma cells have a poor ability to mediate oxidative stress, which may be attributed to constitutive abnormalities in their melanosomes. We hypothesize that disorganization of the melanosomes will allow chemical targeting of the melanin within. Chemical studies show that under oxidative conditions, synthetic melanins demonstrate increased metal affinity and a susceptibility to redox cycling with oxygen to form reactive oxygen species. The electron paramagnetic resonance (EPR)-active 5,5,-dimethyl-pyrollidine N-oxide spin adduct was used to show that binding of divalent Zn or Cu to melanin induces a pro-oxidant response under oxygen, generating superoxide and hydroxyl radicals. A similar pro-oxidant behaviour is seen in melanoma cell lines under external peroxide stress. Melanoma cultures grown under 95% O2/5% CO2 atmospheres show markedly reduced viability as compared with normal melanocytes. Cu- and Zn-dithiocarbamate complexes, which induce passive uptake of the metal ions into cells, show significant antimelanoma activity. The antimelanoma effect of metal- and oxygen-induced stress appears additive rather than synergistic; both treatments are shown to be significantly less toxic to melanocytes. [source]