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.

Fluid dynamics of self-propelled microorganisms, from individuals to concentrated populations

Abstract: Nearly close-packed populations of the swimming bacterium Bacillus subtilis form a collective phase, the “Zooming BioNematic” (ZBN). This state exhibits large-scale orientational coherence, analogous to the molecular alignment of nematic liquid crystals, coupled with remarkable spatial and temporal correlations of velocity and vorticity, as measured by both novel and standard applications of particle imaging velocimetry. The appearance of turbulent dynamics in a system which is nominally in the regime of Stokes flow can be understood by accounting for the local energy input by the swimmers, with a new dimensionless ratio analogous to the Reynolds number. The interaction between organisms and boundaries, and with one another, is modeled by application of the methods of regularized Stokeslets.

One‐Step Synthesis of Nb2O5/C/Nb2C (MXene) Composites and Their Use as Photocatalysts for Hydrogen Evolution

Abstract: Hydrogen production through facile photocatalytic water splitting is regarded as a promising strategy to solve global energy problems. Transition-metal carbides (MXenes) have recently drawn attention as potential co-catalyst candidates for photocatalysts. Here, we report niobium pentoxide/carbon/niobium carbide (MXene) hybrid materials (Nb2 O5 /C/Nb2 C) as photocatalysts for hydrogen evolution from water splitting. The Nb2 O5 /C/Nb2 C composites were synthesized by one-step CO2 oxidation of Nb2 CTx . Nb2 O5 grew homogeneously on Nb2 C after mild oxidation, during which some amorphous carbon was also formed. With an optimized oxidation time of 1.0 h, Nb2 O5 /C/Nb2 C showed the highest hydrogen generation rate (7.81 μmol h-1 gcat-1 ), a value that was four times higher than that of pure Nb2 O5 . The enhanced performance of Nb2 O5 /C/Nb2 C was attributed to intimate contact between Nb2 O5 and conductive Nb2 C and the separation of photogenerated charge carriers at the Nb2 O5 /Nb2 C interface; the results presented herein show that transition-metal carbide are promising co-catalysts for photocatalytic hydrogen production.

Application of Computer-assisted Interviews to Sexual Behavior Research

Abstract: Collection of sensitive data with the use of video-enhanced, computer-assisted, self-administered interviews (V-CASI) has the potential to reduce interview bias and improve the validity of the study. The purpose of this study was to compare responses to sensitive questions elicited by V-CASI and by face-to-face interview (FTFI) methods. Women attending a New Orleans, Louisiana, public family planning or sexually transmitted disease clinic from July 1995 to July 1996, diagnosed with a Chlamydia trachomatis infection responded to eight close-ended behavioral questions (four socially undesirable, two socially desirable, and two neutral behaviors) using both FTFI and V-CASI techniques in a randomized crossover design. Of the 280 women included, the mean age was 23 years, 95 percent were African American, and 71 percent felt comfortable using computers. While kappa scores indicated good-to-excellent agreement between interview techniques, women tended to admit to socially undesirable behaviors more often on V-CASI compared with FTFI. Thirty percent of the women gave a discrepant response between V-CASI and FTFI toward social desirability. Women who reported a socially undesirable behavior in V-CASI (i.e., more than two sex partners and infrequent condom usage) were more likely to have a discrepant response. Utilization of the same logistic regression model to predict condom use yielded different results when data from V-CASI were used compared with data from FTFI. The V-CASI technique can reduce social desirability bias and improve validity in research requiring information on sensitive sexual behaviors.

Placement in Foster Care Enhances Quality of Attachment Among Young Institutionalized Children

Abstract: This study examined classifications of attachment in 42-month-old Romanian children (N = 169). Institutionalized since birth, children were assessed comprehensively, randomly assigned to care as usual (CAU) or to foster care, and compared to family-reared children. Attachment classifications for children in foster care were markedly different from those in the CAU. Importantly, children placed in foster care before 24 months were more likely to have secure attachments and if placed earlier were less likely to have disorganized or insecure-other attachments. Cognitive status predicted greater likelihood of organized attachment in the CAU and greater likelihood of secure attachment in the foster care and never-institutionalized groups. Foster care is an important intervention to reduce the adverse effects following early deprivation.

High rates of organic carbon burial in fjord sediments globally

Abstract: Fjords have been hypothesized to be hotspots of organic carbon burial. A global compilation of organic carbon data and sedimentation rates shows that fjords sequester twice as much carbon as other ocean regions.