Tulane University

About: Tulane University is a education organization based out in New Orleans, Louisiana, United States. It is known for research contribution in the topics: Population & Blood pressure. The organization has 24478 authors who have published 47205 publications receiving 1944993 citations. The organization is also known as: University of Louisiana.

Attachment Disturbances in Young Children. I: The Continuum of Caretaking Casualty

Abstract: Objective: To determine whether signs of disordered attachment were greater in young children being reared in more socially depriving caregiving environments. Method: Three groups of children were studied by means of structured interviews with caregivers that were administered over several months in Bucharest, Romania, in 1999: (1) 32 toddlers living in a typical unit (standard care) in a large institution in Bucharest; (2) 29 toddlers living in the same institution on a “pilot unit” designed to reduce the number of adults caring for each child; and (3) 33 toddlers living at home who had never been institutionalized. The presence of attachment disorders and other behavioral problems was assessed by caregiver/ parent report. Results: Children on the typical unit (standard care) had significantly more signs of disordered attachment than children in the other two groups. Both the emotionally withdrawn and the indiscriminately social pattern of attachment disorder were apparent in these children, but cluster analysis suggested that mixed patterns are more typical. Conclusions: The continuum of caretaking casualty is reflected by increasing signs of disordered attachment in toddlers living in more socially depriving environments. J. Am. Acad. Child Adolesc. Psychiatry, 2002, 41(8):972‐982. Key Words: reactive attachment disorder, inhibited attachment disorder, children in institutions, deprivation, neglect.

Tests of a ladder of density functionals for bulk solids and surfaces

Abstract: The local spin-density approximation (LSDA) and the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE) are fully non-empirical realizations of the first two rungs of ``Jacob's ladder'' of exchange-correlation density functionals. The recently proposed non-empirical meta-GGA of Tao, Perdew, Staroverov, and Scuseria (TPSS), featuring the kinetic energy density as an additional local ingredient, completes the third rung. A hierarchy of these functionals, complemented by the meta-GGA of Perdew, Kurth, Zupan, and Blaha (PKZB), is tested in self-consistent Gaussian-type orbital calculations of equilibrium lattice constants, bulk moduli, and cohesive energies for 18 solids, and in studies of the jellium surface energy. The ascent of the ladder generally results in better performance, although most of the improvement for bulk solids occurs in the transition from LSDA to PBE. For the jellium surface energy, PBE is less accurate than LSDA, but PKZB and TPSS are more accurate. We support the idea that most of the error of these functionals for bulk solids arises in the description of core--valence interaction, by demonstrating that it can be removed through adjustment of the corresponding term in the equation of state. Overall, TPSS gives the best description of solids and surfaces, as it was found to do for molecules in earlier work.

The Gal(alpha 1-4)Gal-specific tip adhesin of Escherichia coli P-fimbriae is needed for pyelonephritis to occur in the normal urinary tract.

Abstract: Nonobstructive acute pyelonephritis in humans is most often caused by P-fimbriated Escherichia coli. P-fimbriae are heteropolymeric fibers carrying a Gal(alpha 1-4)Gal-specific PapG adhesin at its distal end. The pyelonephritic strain DS17 expresses P-fimbriae from a single gene cluster. A mutant strain, DS17-8, which expresses P-fimbriae tacking the PapG adhesin, was constructed by allelic replacement introducing a 1-bp deletion early in the papG gene. In cynomolgus monkeys, DS17 and DS17-8 were equally able to cause bladder infection, whereas only the wild-type strain DS17 could cause pyelonephritis as monitored by bacteriological, functional, and histopathological criteria. Since DS17, but not DS17-8, adheres to renal tissue, these data underscore the critical role of microbial adherence to host tissues in infectious disease and strongly suggest that the PapG tip adhesin of P-fimbriae is essential in the pathogenesis of human kidney infection.

Hydroxyapatite-coated titanium for orthopedic implant applications.

Abstract: The interface mechanical characteristics and histology of commercially pure (CP) titanium- and hydroxyapatite- (HA) coated Ti-6Al-4V alloy were investigated. Interface shear strength was determined using a transcortical push-out model in dogs after periods of three, five, six, ten, and 32 weeks. Undecalcified histologic techniques with implants in situ were used to interpret differences in mechanical response. The HA-coated titanium alloy implants developed five to seven times the mean interface strength of the uncoated, beadblasted CP titanium implants. The mean values for interface shear strength increased up to 7.27 megaPascals (MPa) for the HA-coated implants after ten weeks of implantation, and the maximum mean value of interface shear strength for the uncoated CP titanium implants was 1.54 MPa. For both implant types there was a slight decrease in mean shear strength from the maximum value to that obtained after the longest implantation period (32 weeks). Histologic evaluations in all cases revealed mineralization of interface bone directly onto the HA-coated implant surface, with no fibrous tissue layer interposed between the bone and HA visible at the light microscopic level. The uncoated titanium implants had projections of bone to the implant surface with apparent direct bone-implant apposition observed in some locations. Measurements of the HA coating material made from histologic sections showed no evidence of significant HA resorption in vivo after periods of up to 32 weeks.