Showing papers by "Tulane University published in 1993"
TL;DR: It is shown that murine tumor necrosis factor alpha labeled with 125I (I-mTNF alpha) crosses the blood-brain barrier (BBB) after i.v. injection, suggesting that TNF alpha is sequestered by the brain.
555 citations
TL;DR: In this paper, the authors studied the concentration behavior of positive bound states of the nonlinear Schrodinger equation and proved that the positive radial solutions with least energy among all nontrivial radial solutions must concentrate at the origin ash→0+.
Abstract: We study the concentration behavior of positive bound states of the nonlinear Schrodinger equation
$$ih\frac{{\partial \psi }}{{\partial t}} = \frac{{ - h^2 }}{{2m}}\Delta \psi + V\left( x \right)\psi - \gamma \left| \psi \right|^{p - 1} \psi .$$
Under certain condition ofV, we show that positive ground state solutions must concentrate at global minimum points ofV ash→0+; moreover, a point at which a sequence of positive bound states concentrates must be a critical point ofV. In cases thatV is radial, we prove that the positive radial solutions with least energy among all nontrivial radial solutions must concentrate at the origin ash→0+.
515 citations
TL;DR: It is argued that the problem of plan recognition, inferring an agent's plan from observations, is largely a problem of inference under conditions of uncertainty and an approach to the plan recognition problem that is based on Bayesian probability theory is presented.
483 citations
TL;DR: In this paper, the authors examined the relationship of both positive and negative affectivity to organizational commitment, turnover intentions, global job satisfaction and performance, and concluded that negative affect is associated with lower levels of job satisfaction.
Abstract: Previous research has shown that dispositional negative affect (NA) is associated with lower levels of job satisfaction. Little research has been conducted, however, on other organizational implications of negative affect or on the potential effects of dispositional positive affect (PA). The present studies examined the relationship of both positive and negative affectivity to organizational commitment, turnover intentions, global job satisfaction and performance. In the first study both NA and PA were associated with organizational commitment and turnover intentions. Additionally, commitment mediated the relationship between dispositional affectivity and turnover. Finally, PA and tenure interacted to predict job performance, such that PA and job performance were positively related, but only for high tenure employees. In Study 2 the findings were generally similar, but not identical. Both NA and PA were related to global job satisfaction and turnover intentions. However, only PA was related to affective organizational commitment. Moreover, both job satisfaction and affective commitment mediated the relationship between dispositional affectivity and turnover intentions. Finally, unlike Study 1, PA was not related to job performance. Rather, NA and tenure interacted such that when individuals were lower in tenure, NA was negatively related to performance.
483 citations
TL;DR: Reanalyses of four data sets offered further support for the hypothesized "nuisance" properties of NA in studies involving relations between self-reports of stressors and strain.
Abstract: On the basis of a brief review of the health, organizational, and personality psychology literatures supportive of the expectation that observed relations between self-reports of stressors and strains are influenced by the mood-dispositional dimension negative affectivity (NA), reanalyses of four data sets were conducted. The results of these reanalyses, contrary to the assertions of several authors in the applied psychology literature, offered further support for the hypothesized "nuisance" properties of NA in studies involving relations between self-reports of stressors and strain. A discussion of how NA and other mood-dispositional dimensions may be of interest to investigators concerned with relations between self-reports of any condition of employment and any affective state of workers is presented.
481 citations
TL;DR: A framework was proposed that posits that both objective life circumstances and global personality dimensions indirectly affect SWB through their effects on the interpretation of life circumstances.
Abstract: As a means of integrating bottom-up and top-down theories of subjective well-being (SWB), a framework was proposed that, in part, posits that both objective life circumstances and global personality dimensions indirectly affect SWB through their effects on the interpretation of life circumstances. This proposition was tested both cross-sectionally and longitudinally among a sample of approximately 375 men and women. Personality was operationalized in terms of the dispositional trait negative affectivity (NA), and the life circumstance investigated was health. Strong support was obtained for the hypothesized indirect effects of NA and objective health on SWB. Implications of the integrative framework for the study of SWB are discussed.
419 citations
TL;DR: A perturbation theory is developed for the correlation energy of a finite-density system, with respect to the coupling constant \ensuremath{\alpha} which multiplies the electron-electron repulsion operator in T=T.
Abstract: A perturbation theory is developed for the correlation energy ${\mathit{E}}_{\mathit{c}}$[n], of a finite-density system, with respect to the coupling constant \ensuremath{\alpha} which multiplies the electron-electron repulsion operator in ${\mathit{H}}^{\mathrm{\ensuremath{\alpha}}}$=T^+\ensuremath{\alpha}V${\mathrm{^}}_{\mathit{e}\mathit{e}}$+${\mathit{tsum}}_{\mathit{i}}$${\mathit{v}}_{\mathrm{\ensuremath{\alpha}}}$(${\mathbf{r}}_{\mathit{i}}$). The external potential ${\mathit{v}}_{\mathrm{\ensuremath{\alpha}}}$ is constrained to keep the gound-state density n fixed for all \ensuremath{\alpha}\ensuremath{\ge}0. ${\mathit{v}}_{\mathrm{\ensuremath{\alpha}}}$ is given completely in terms of functional derivatives at full charge (\ensuremath{\alpha}=1), from which ${\mathit{E}}_{\mathit{c}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]=${\mathit{e}}_{\mathit{c},2}$[n]+ ${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$${\mathit{e}}_{\mathit{c},3}$[n]+${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}2}$${\mathit{e}}_{\mathit{c},4}$[n]+..., where each ${\mathit{e}}_{\mathit{c},}$j[n] is expressed in terms of integrals involving Kohn-Sham determinants. Here, ${\mathit{n}}_{\ensuremath{\lambda}}$(x,y,x)=${\ensuremath{\lambda}}^{3}$n(\ensuremath{\lambda}x,\ensuremath{\lambda}y,\ensuremath{\lambda}z) and \ensuremath{\lambda}=${\mathrm{\ensuremath{\alpha}}}^{\mathrm{\ensuremath{-}}1}$. The identification of ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}\mathrm{\ensuremath{\infty}}}$${\mathit{E}}_{\mathit{c}}$[${\mathit{n}}_{\ensuremath{\lambda}}$], which is a high-density limit, as the second-order energy ${\mathit{e}}_{\mathit{c},2}$[n] allows one to compute bounds upon ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}\mathrm{\ensuremath{\infty}}}$${\mathit{E}}_{\mathit{c}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]; the bounds imply that ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}\mathrm{\ensuremath{\infty}}}$${\mathit{E}}_{\mathit{c}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]\ensuremath{\simeq}${\mathit{E}}_{\mathit{c}}$[n] for a large class of small atoms and molecules, and suggest that ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}\mathrm{\ensuremath{\infty}}}$${\mathit{E}}_{\mathit{c}}$[${\mathit{n}}_{\ensuremath{\lambda}}$] should be of the same order of magnitude as ${\mathit{E}}_{\mathit{c}}$[n] in finite insulators and semiconductors.
380 citations
TL;DR: Comparison of observed and recalled food intakes showed no significant differences in percentage of energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat or in the amount of sodium consumed, although there were differences in energy intakes.
Abstract: Objective The objective of the study was to validate the use of 24-hour recalls assisted by food records as a dietary assessment tool for use with third-grade children. Design Trained staff observed children during mealtime at school, and parents observed and recorded what children ate in their presence. The following day children participated in a 24-hour recall interview. Children's ability to recall what they consumed during a 24-hour period was compared with observational data collected during the same period. Setting All data were collected in elementary school settings at four sites involved in the Child and Adolescent Trial for Cardiovascular Health. Subjects The sample of 49 children was self-selected, based on parents' willingness to observe and record their child's food intake. Main outcome measures Recalled and observed data for energy and nutrient levels were compared using mean energy and nutrient analysis and quartile classification. In addition, recalled and observed foods were compared by meal type and estimation of portion size. Statistical analysis performed Paired t tests, Pearson and Spearman correlations, and classification analysis were used to compare recalled and observed data. Results Comparison of observed and recalled food intakes showed no significant differences in percentage of energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat or in the amount of sodium consumed, although there were differences in energy intakes. Spearman rank order correlations between recalled and observed nutrients ranged from .45 to .79. A 77.9% agreement was found across all meals in the food items children recalled having consumed compared with those adults actually observed them consuming. Conclusions We conclude that the 24-hour recall assisted by food records is a valid method for assessing the dietary intake of children as young as 8 years old for the purpose of group comparison.
303 citations
01 Jan 1993
242 citations
TL;DR: The authors found that diagnoses of chronic PTSD in combat veterans are associated with cognitive performance deficits, when comparisons are made with military troops judged to be free of stress-related psychopathology, thus highlighting the need for continued investigation of the neuropsychologlcal sequelae of prolonged stress exposure.
Abstract: Vietnam combat veterans assigned diagnoses of PTSD were compared on measures of attention/concentration, new learning, and memory with Army National Guard enlistees who reported no unusual traumatic events or stress-related symptoms. Results showed that PTSD veterans performed more poorly than the comparison sample on a measure of verbal learning, exhibiting less proficient cumulative acquisition across repeated exposures, greater sensitivity to proactive interference, and more perseverative errors. Veterans with PTSD diagnoses also evidenced impairments in word fluency and visual attention/tracking abilities. These preliminary findings suggest that diagnoses of chronic PTSD in combat veterans are associated with cognitive performance deficits, when comparisons are made with military troops judged to be free of stress-related psychopathology. Results are consistent with self-reported complaints of concentration and memory impairments among PTSD-diagnosed clinical samples, thus highlighting the need for continued investigation of the neuropsychologlcal sequelae of prolonged stress exposure.
230 citations
TL;DR: L-arginine administration from 2 days prior to and 2 weeks following catheter-induced injury to the rabbit thoracic aorta attenuated the development of intimal hyperplasia by 39% as compared with untreated controls, suggesting that the mechanism for this effect is the conversion of L- arginine to nitric oxide.
TL;DR: A 140-pS channel which is permeable to both cations and anions was identified on the parasitophorous vacuole membrane, the outer of the two membranes that separate the parasite from the erythrocyte cytosol, and may be essential for fulfilling the parasite's metabolic demands.
Abstract: During its 48-hour cycle inside the red blood cell, the human malaria parasite, Plasmodium falciparum, increases its volume 25-fold and divides asexually. This rapid growth demands large amounts of nutrients, a problem exacerbated by the lower metabolic rate and relative ionic impermeability of the host red blood cell. Direct passage of small nutrients across the two membranes that separate the parasite from the erythrocyte cytosol may be important for parasite development and has been demonstrated for radiolabelled glucose, amino acids, and purine nucleosides. Flux studies on plasmodia are limited, however, to suspensions of erythrocyte-free parasites and so cannot be used to examine the individual transport properties of the two membranes involved. Here we use the cell-attached patch clamp method to overcome this limitation. After removing the intervening red blood cell membrane and forming gigaohm seals on the small (3-5 microns) parasite, we studied transport across the parasitophorous vacuole membrane (PVM), the outer of the two membranes that separate the parasite from the erythrocyte cytosol. A 140-pS channel which is permeable to both cations and anions was identified on the PVM. This channel is present at high density, is open more than 98 per cent of the time at the resting potential of the PVM, and is permeable to lysine and glucuronate. The channel can readily transport amino acids and monosaccharides across the PVM and may be essential for fulfilling the parasite's metabolic demands.
TL;DR: The data obtained from perfused tubules indicate that the proximal tubule adds substantial amounts of ANG II or a precursor into the tubular lumen, providing further evidence that intratubular ANG II concentrations are in the nanomolar range and are regulated independently of the plasma ANG II levels.
Abstract: It is now established that all of the components necessary for the local formation of angiotensin II (ANG II) coexist in the kidney and can alter local ANG II production rate. However, data on ANG ...
TL;DR: The importance of breakfast to overall dietary quality and adequacy in school-age children is confirmed, with results indicated that 16% of all children skipped breakfast; the highest percentage was in black girls (24%).
Abstract: Breakfast consumption patterns were assessed for 467 10-year-old children (59% white, 50% girls), who were interviewed in 1984–1985 or in 1987–1988. Consumption patterns were then related to mean daily nutrient intake patterns. More whites (56%) and more girls (46%) ate breakfast at home, whereas more blacks (58%) and more boys (49%) ate breakfast at school. Results indicated that 16% of all children skipped breakfast; the highest percentage was in black girls (24%). Breakfast consumption made a significant contribution to the child's mean daily nutrient intake. The average total energy intake was significantly lower for children who did not consume breakfast (mean = 1,821 kcal) and for children who consumed breakfast at home (mean = 2,098 kcal) compared with children who consumed breakfast at school (mean = 2,326 kcal). A similar pattern was noted for macronutrient contribution. Percentage of total energy from fat was lower in children who did not eat breakfast (34%) compared with those who did (37% to 39%), yet percentage of energy from carbohydrate was higher (53%) in children who did not eat breakfast. Children who skipped breakfast did not make up the differences in dietary intakes at other meals. A higher percentage of children who did not consume breakfast compared with those who ate breakfast did not meet two thirds of the Recommended Dietary Allowance for vitamins and minerals. These data confirm the importance of breakfast to overall dietary quality and adequacy in school-age children.
TL;DR: Within the amplified DNA segment, regions were sequenced which yield highly variable, moderately variable and highly conserved sequence information, appropriate for comparison with other species in the phylum Microspora at all taxonomic levels.
Abstract: . A segment of ribosomal DNA, about 1,350 base pairs long, was amplified from the microsporidian species Encephalitozoon hellem, isolated from AIDS patients, and Encephalitozoon cuniculi. the amplified DNA segment extends from position 530 in the small ribosomal RNA subunit to position 580 in the large ribosomal RNA subunit. A comparison of sequence data from this region for Encephalitozoon hellem and Encephalitozoon cuniculi shows relatively high sequence similarity, supporting the placement of these two organisms in the same genus. At the same time, sequence differences between the two organisms confirm that they are not the same species. Three separate isolates of E. hellem were sequenced in the highly variable intervening spacer region. the sequence was identical for all three isolates. Within the amplified DNA segment, regions were sequenced which yield highly variable, moderately variable and highly conserved sequence information, appropriate for comparison with other species in the phylum Microspora at all taxonomic levels. We suggest that sequence data from these regions be included in future species descriptions for the purposes of species identification and phylogenetic analysis. Restriction digests of the amplified region are presented and give a rapid method for distinguishing between the two Encephalitozoon species.
TL;DR: An Aspergillus parasiticus gene, designated apa-2, was identified as a regulatory gene associated with aflatoxin biosynthesis and was found to complement an A. flavus afl-2 mutant strain for a flatoxin production, suggesting that apA-2 is functionally homologous to aFL-2.
Abstract: An Aspergillus parasiticus gene, designated apa-2, was identified as a regulatory gene associated with aflatoxin biosynthesis. The apa-2 gene was cloned on the basis of overproduction of pathway intermediates following transformation of fungal strains with cosmid DNA containing the aflatoxin biosynthetic genes nor-1 and ver-1. Transformation of an O-methylsterigmatocystin-accumulating strain, A. parasiticus SRRC 2043, with a 5.5-kb HindIII-XbaI DNA fragment containing apa-2 resulted in overproduction of all aflatoxin pathway intermediates analyzed. Specific enzyme activities associated with the conversion of norsolorinic acid and sterigmatocystin were increased approximately twofold. The apa-2 gene was found to complement an A. flavus afl-2 mutant strain for aflatoxin production, suggesting that apa-2 is functionally homologous to afl-2. Comparison of the A. parasiticus apa-2 gene DNA sequence with that of the A. flavus afl-2 gene (G. A. Payne, G. J. Nystorm, D. Bhatnagar, T. E. Cleveland, and C. P. Woloshuk, Appl. Environ. Microbiol. 59:156-162, 1993) showed that they shared > 95% DNA homology. Physical mapping of cosmid subclones placed apa-2 approximately 8 kb from ver-1.
TL;DR: The ability of the kidney to alter its sodium excretion in response to acute changes in renal arterial pressure in anesthetized dogs is examined, suggesting that NO may participate in the mediation of the pressure-natriuresis response.
Abstract: Inhibition of nitric oxide (NO) synthesis by intrarenal administration of nitro-L-arginine (NLA) leads to decreases in urinary sodium excretion (UNaV) in association with the increases in renal vascular resistance (RVR). In the present study, we examined the ability of the kidney to alter its sodium excretion in response to acute changes in renal arterial pressure (RAP) in anesthetized dogs before and during intrarenal infusion of NLA (50 micrograms.kg-1.min-1). NO synthesis inhibition in 11 dogs increased RVR by 32 +/- 4% and decreased renal blood flow (RBF) by 25 +/- 3%, outer cortical blood flow by 25 +/- 6%, urine flow by 37 +/- 14%, UNaV by 71 +/- 5%, and fractional excretion of sodium (FENa) by 71 +/- 4%. Glomerular filtration rate was not significantly changed during NLA infusion. As previously reported, there was suppression of the RBF autoregulation plateau during NO synthesis inhibition. In addition, there was a marked attenuation of urine flow and UNaV responses to reductions in RAP (150 to 75 mmHg), with significant reductions in the slopes of the relationships between RAP vs. UNaV and RAP vs. FENa during NLA infusion. Similar responses were observed in nine other dogs treated with the angiotensin receptor antagonist losartan, indicating that an augmented activity of the renin-angiotensin system is not responsible for attenuation of the slope of the pressure-natriuresis relationship during NLA infusion. These data suggest that NO may participate in the mediation of the pressure-natriuresis response.
TL;DR: Dynamical modeling and experimental analyses indicate that an intentional parameter phi psi and 2 control parameters omega c (coupled frequency) and delta omega (difference between uncoupled eigen-frequencies) affect phi.
Abstract: In 1:1 frequency locking, the interlimb phase difference phi is an order parameter quantifying the spatial-temporal organization of 2 rhythmic subsystems. Dynamical modeling and experimental analyses indicate that an intentional parameter phi psi (intended coordination mode, phi = 0 degrees or phi = 180 degrees) and 2 control parameters omega c (coupled frequency) and delta omega (difference between uncoupled eigen-frequencies) affect phi. An experiment was conducted on 1:1 frequency locking in which phi psi, omega c, and delta omega were manipulated using a paradigm in which a person swings hand-held pendulums. As delta omega deviated from 0, the observed phi deviated from the phi psi, indicating a displacement in the phi attractor point. The displacements were exaggerated by increasing omega c. The displacements were coordinated with a decrease in the stability of phi and with higher harmonics in power spectrum of phi. Implications of the results for modeling interlimb coordination are discussed.
TL;DR: An apparent increase over time is noted in the percent of children meeting dietary recommendations for total fat, saturated fatty acid, and cholesterol, yet, few children meet the prudent diet recommendations.
TL;DR: The spline-Laplacian accurately estimates isolated dipoles or distributed sources, is insensitive to subcortical sources and to sources which originate outside the boundaries of the electrode array, and acts as a bandpass spatial filter whose characteristics appear to provide a good match to the volume conduction of intracranial sources through human heads.
Abstract: Spline generated surface Laplacians are introduced as an effective method for estimating neocortical source activity at moderate scales. The method appears to be robust to the unavoidable perturbations of measured potentials and errors of head geometry and resistivity that are certain to occur in clinical or research settings. In particular, the surface Laplacian is derived for general ellipsoidal surfaces in terms of the spline function. The spline-Laplacian accurately estimates isolated dipoles or distributed sources, is insensitive to subcortical sources and to sources which originate outside the boundaries of the electrode array, and acts as a bandpass spatial filter whose characteristics appear to provide a good match to the volume conduction of intracranial sources through human heads. As a result, spatial resolution is improved over that obtained with conventional EEG by at least a factor of three. This improvement is likely to have a significant impact on both medical and cognitive studies involving EEG. >
TL;DR: It is indicated that loss of HBsAg is associated with marked improvements in clinical and serum biochemical features of chronic hepatitis B, yet mild degrees of hepatitis and low levels of viral DNA may persist in the liver.
TL;DR: For the purpose of approximating the evict density-functional exchange-correlation energy E sc, the coordinate scaling identity E a xc is established for α=λ -1 , or E λ xc [n λ ]=λ 2 E xc (x,y,x) and n λ 3 n(λx,λy,λz)
Abstract: For the purpose of approximating the exact density-functional exchange-correlation energy ${\mathit{E}}_{\mathrm{xc}}$[n], we previously established the coordinate scaling identity ${\mathit{E}}_{\mathrm{xc}}^{\mathrm{\ensuremath{\alpha}}}$[n]=${\mathrm{\ensuremath{\alpha}}}^{2}$${\mathit{E}}_{\mathrm{xc}}$[${\mathit{n}}_{\ensuremath{\lambda}}$] for \ensuremath{\alpha}=${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$, or ${\mathit{E}}_{\mathrm{xc}}^{\ensuremath{\lambda}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]=${\ensuremath{\lambda}}^{2}$${\mathit{E}}_{\mathrm{xc}}$[n], where ${\mathit{E}}_{\mathrm{xc}}^{\mathrm{\ensuremath{\alpha}}}$[n] is the exchange-correlation energy functional for electronic charge \ensuremath{\surd}\ensuremath{\alpha} e and where ${\mathit{n}}_{\ensuremath{\lambda}}$(x,y,z)=${\ensuremath{\lambda}}^{3}$n(\ensuremath{\lambda}x,\ensuremath{\lambda}y,\ensuremath{\lambda}z). This identity is utilized here to derive the low-density limit ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}0}$ ${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$${\mathit{E}}_{\mathrm{xc}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]=${\mathrm{inf}}_{\mathrm{\ensuremath{\Psi}}\ensuremath{\rightarrow}\mathit{n}}$ 〈\ensuremath{\Psi}\ensuremath{\Vert}V${\mathrm{^}}_{\mathit{e}\mathit{e}}$\ensuremath{\Vert}\ensuremath{\Psi}〉-(${\mathit{e}}^{2}$/2)FF[n(${\mathbf{r}}_{1}$)n(${\mathbf{r}}_{2}$) /\ensuremath{\Vert}${\mathbf{r}}_{1}$-${\mathbf{r}}_{2}$\ensuremath{\Vert}]${\mathit{d}}^{3}$${\mathit{r}}_{1}$${\mathit{d}}^{3}$${\mathit{r}}_{2}$, which allows us to express the Lieb-Oxford bound in the tighest-possible manner, namely, ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}0}$ ${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$${\mathit{E}}_{\mathrm{xc}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]\ensuremath{\ge}-${\mathit{Ce}}^{2}$F${\mathit{n}}^{4/3}$(r)${\mathit{d}}^{3}$r, where 1.43\ensuremath{\le}C\ensuremath{\le}1.68. Meaningful adherences to and violations of the bound are presented to demonstrate that it is surprisingly tight and thus quite useful. Other key properties of ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}0}$ ${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$${\mathit{E}}_{\mathrm{xc}}$[${\mathit{n}}_{\ensuremath{\lambda}}$] are found, including the observation that ${\mathrm{lim}}_{\ensuremath{\lambda}\ensuremath{\rightarrow}0}$ ${\ensuremath{\lambda}}^{\mathrm{\ensuremath{-}}1}$${\mathit{E}}_{\mathrm{xc}}$[${\mathit{n}}_{\ensuremath{\lambda}}$]+(${\mathit{e}}^{2}$/2)FF[n(${\mathbf{r}}_{1}$)n(${\mathbf{r}}_{2}$) /\ensuremath{\Vert}${\mathbf{r}}_{1}$-${\mathbf{r}}_{2}$\ensuremath{\Vert}]${\mathit{d}}^{3}$${\mathit{r}}_{1}$${\mathit{d}}^{2}$${\mathit{r}}_{2}$ is convex, which is a severe constraint. We discuss these and other exact relationships as formal tests of generalized-gradient approximations (GGA's) for exchange and correlation.We find that the Perdew-Wang 1991 (PW91) GGA respects many of the known exact relationships, including those respected by the local-density approximation plus many others that are violated by the local-density approximation. We present a minor variant of the PW91 correlation-energy functional which additionally satisfies a strong \ensuremath{\lambda}\ensuremath{\rightarrow}\ensuremath{\infty} (high-density) constraint. Finally, we show that atomic densities are much closer to the high-density than to the low-density limit.
TL;DR: Endometrial thickness the day of hCG administration is prognostic of fecundity and continuing pregnancy in cycles of ovulation induction, and endometrial pattern was unrelated to pregnancy.
TL;DR: The present results show that in the peripheral vascular bed of the cat, Ang-(1-7) causes vasodilation or modest vasoconstriction, depending on the dose and the regional vascular bed studied, and suggest that the vasodilator effect of the peptide may be mediated in part by the release of endothelium-derived relaxing factor and the vasconstrictor effect by activation of the AT1 receptor subtype.
TL;DR: The results provided quantitative data on the effects of specific 4-VO criteria and durations on selective, bilaterally symmetrical CA1 pyramidal cell damage, differential CA1-CA3 cell vulnerability, and prospect of a "therapeutic window" for pharmacological treatment of CA1 neuronal injury.
Journal Article•
TL;DR: The presence of this ER variant in breast tumor cell lines, as well as breast tumor biopsies and uterine tissue, suggests that it is a naturally occurring variant that may arise by alternative splicing, and whose overexpression may be involved in the progression of breast tumors to a hormone-independent state.
Abstract: Estrogen receptor (ER) expression by breast tumors is an important predictor of disease-free survival in breast cancer patients and, more importantly, is a strong predictor of response to endocrine therapy. Variant forms of the ER may play an important role in the loss of hormone responsiveness and the progression to hormone independence. We have examined a panel of human breast tumor cell lines, both ER-positive and ER-negative, and have identified an ER mRNA variant containing a deletion of exon 5 in the ER-negative BT-20 and ER-positive MCF-7 cell lines. This exon 5 deletion variant has been previously reported to be overexpressed in ER-negative/progesterone receptor-positive breast tumors. Using RNase protection analysis, we have found that the predominant ER transcript in the BT-20 cells is the exon 5 deletion variant, while the principal transcript in MCF-7 cells is the wild-type ER mRNA. The variant ER transcript is translated into a truncated receptor protein of approximately M(r) 42,000 when expressed in yeast and, more important, in breast tumor cells. This is the first demonstration of an exon 5 deletion variant ER protein. Functional analysis has shown that this variant ER possesses constitutive transcriptional regulatory activity with respect to an estrogen-regulated reporter gene construct in a yeast expression system. The presence of this ER variant in breast tumor cell lines, as well as breast tumor biopsies and uterine tissue, suggests that it is a naturally occurring variant that may arise by alternative splicing, and whose overexpression may be involved in the progression of breast tumors to a hormone-independent state.
01 Jan 1993
TL;DR: The authors discusses the mechanisms that underlie negative affect toward outgroup members and presents some supporting evidence from both own research and some of the hallmark works in stereotyping, affect, and prejudice.
Abstract: Publisher Summary This chapter presents the negative interdependence and prejudice. Numerous researchers have attempted to account for the prejudice associated with outgroup members. Some approaches to this problem start at the level of the individual and largely confine their analysis to processes that occur within the individual. Other approaches start at the level of society, examining the interactions of groups as groups, that is, concentrating their analyses on several people interacting with several other people. The chapter discusses both Allport's genuine conflicts of interest and many imaginary conflicts. It discusses the mechanisms that underlie negative affect toward outgroup members and presents some supporting evidence from both own research and some of the hallmark works in stereotyping, affect, and prejudice. The chapter discusses two major techniques of negative affect reduction in light of the current perspective.
TL;DR: In this paper, an economic interpretation of seasonal cointegration and integration is presented using the notion of a slightly impatient borrowing-constrained utility-maximizing consumer, and the test statistics for non-cointegration occurring at the frequency 1 2 of a cycle have the same distribution as the test statistic obtained for the zero frequency case by Engle and Granger (1987) and Engle, Granger, and Yoo (1987).
TL;DR: Investigation of the effects on divalent cation uptake in rat thymic lymphocytes of three structurally related imidazole reagents finds that all three of these agents are potent inhibitors of isolated sarcoplasmic reticulum Ca(2+)-ATPase, and concludes that econazole, miconazoles, and SKF 96365 inhibit cytochrome P-450-independent filling of intracellular Ca2+ pools.
Abstract: Cytochrome P-450 has been proposed to underlie the mechanism of regulation of the plasma membrane Ca2+ permeability by the Ca2+ content of the inositol 1,4,5-trisphosphate-sensitive Ca2+ pool. We have investigated the effects on divalent cation uptake in rat thymic lymphocytes of three structurally related imidazole reagents reported to inhibit redox mechanisms. Changes in intracellular Ca2+ concentration and intracellular Mn2+ concentration were measured fluorimetrically with indo-1 and/or quin-2. Econazole, miconazole, and SKF 96365 were found to be potent blockers of Ca2+ and Mn2+ uptake activated by release of Ca2+ from intracellular stores induced by thapsigargin. Additionally, we found that concentrations of these agents required to abolish divalent cation uptake also released Ca2+ from the thapsigargin-sensitive intracellular stores, consistent with inhibition of the endosomal Ca(2+)-ATPase. In agreement with this suggestion, we have found that all three of these agents are potent inhibitors of isolated sarcoplasmic reticulum Ca(2+)-ATPase. We conclude that econazole, miconazole, and SKF 96365 inhibit cytochrome P-450-independent filling of intracellular Ca2+ pools, as well as store-regulated Ca2+ entry, and caution against the use of these compounds as selective inhibitors of cytochrome P-450.
TL;DR: Three simple heuristics for the vehicle routeing problem with customer time windows that can be violated by paying appropriate penalties are described, which enables significant reduction in the number of vehicles required and/or the total route distances while controlling both customer penalties and waiting times.
Abstract: We describe three simple heuristics for the vehicle routeing problem with customer time windows that can be violated by paying appropriate penalties. The customer demands are known, and a homogeneous fleet of vehicles stationed at a single depot is considered. The penalty payable to a customer is assumed to be a linear function of the amount of time window violation. Upper limits are imposed on both the penalty payable and the waiting time allowed at any customer. At each customer in a route, the PC-based heuristics simultaneously determine the actual time to begin service, and the next customer to serve. To achieve this, each heuristic uses different measures to compare the cost of waiting and penalty payable, with the benefit obtained by leaving immediately for the next customer. Computational results on a set of benchmark problems show that the procedure is efficient and enables significant reduction in the number of vehicles required and/or the total route distances while controlling both customer penalties and waiting times.