Publications

Abstract We have studied the segregation of a block copolymer of poly(d 8 ‐styrene‐ b ‐2‐vinylpyridine) (dPS‐PVP) at the interface between polystyrene and a random copolymer of poly(styreneran‐4‐hydroxystyrene) (PS‐r‐PPHS). Forward recoil spectrometry (FRES) was used to measure the equilibrium excess ( z * ) of the dPS‐PVP chains at the interface as a function of its volume fraction in the bulk PS phase (ϕ ∞ ). It was found that there is a sharp increase in z * at a critical value of ϕ ∞ . This upturn indicates the formation of a microemulsion of PS and the random copolymer PS‐r‐PPHS due to a vanishing of the interfacial tension caused by the strong adsorption of the block copolymer. Cross‐sectional transmission electron microscopy (TEM) of the interface shows that this microemulsion starts to form at the interface by forming a deeply corrugated structure where the “wavelength” of the corrugations is of the order of 50 nm. © 1995 John Wiley & Sons, Inc.

Additional file 4. Quantification of extracellular n-butanol using GC-FID. The spreadsheet contains the estimated fraction of viable cells after incubation in PBS containing 0.2 and 1% n-butanol, and the measurement values of quantified extracellular n-butanol in induced (ttgABC + ) and non-induced strains (ttgABC - ). The original readings for n-butanol and the internal standard isoprenol are shown, as well as the n-butanol measurements normalized by the standard, and the derived concentrations as volume per volume and milligrams per milliliter. The inlay shows the n-butanol standard curve, indicating that concentrations are in a linear measurement range.

Materials that combine facile synthesis, simple tuning of degradation rate, processability, and biocompatibility are in high demand for use in biomedical applications. We report on acetalated dextran, a biocompatible material that can be formed into microparticles with degradation rates that are tunable over 2 orders of magnitude depending on the degree and type of acetal modification. Varying the degradation rate produces particles that perform better than poly(lactic- co -glycolic acid) and iron oxide, two commonly studied materials used for particulate immunotherapy, in major histocompatibility complex class I (MHC I) and MHC II presentation assays. Modulating the material properties leads to antigen presentation on MHC I via pathways that are dependent or independent of the transporter associated with antigen processing. To the best of our knowledge, this is the only example of a material that can be tuned to operate on different immunological pathways while maximizing immunological presentation.

Anti-resorptive and anabolic agents are often prescribed for the treatment of osteoporosis continuously or sequentially for many years. However their impact on cortical bone quality and bone strength is not clear. Methods Six-month old female rats were either sham operated or ovariectomized (OVX). OVX rats were left untreated for two months and then were treated with vehicle (Veh), hPTH (1–34) (PTH), alendronate (Aln), or raloxifene (Ral) sequentially for three month intervals, for a total of three periods. Mid-tibial cortical bone architecture, mass, mineralization, and strength were measured on necropsy samples obtained after each period. Bone indentation properties were measured on proximal femur necropsy samples. Results Eight or more months of estrogen deficiency in rats resulted in decreased cortical bone area and thickness. Treatment with PTH for 3months caused the deposition of endocortical lamellar bone that increased cortical bone area, thickness, and strength. These improvements were lost when PTH was withdrawn without followup treatment, but were maintained for the maximum times tested, six months with Ral and three months with Aln. Pre-treatment with anti-resorptives was also somewhat successful in ultimately preserving the additional endocortical lamellar bone formed under PTH treatment. These treatments did not affect bone indentation properties. Summary Sequential therapy that involved both PTH and anti-resorptive agents was required to achieve lasting improvements in cortical area, thickness, and strength in OVX rats. Anti-resorptive therapy, either prior to or following PTH, was required to preserve gains attributable to an anabolic agent.

Human trajectory forecasting with multiple socially interacting agents is of\ncritical importance for autonomous navigation in human environments, e.g., for\nself-driving cars and social robots. In this work, we present Predicted\nEndpoint Conditioned Network (PECNet) for flexible human trajectory prediction.\nPECNet infers distant trajectory endpoints to assist in long-range multi-modal\ntrajectory prediction. A novel non-local social pooling layer enables PECNet to\ninfer diverse yet socially compliant trajectories. Additionally, we present a\nsimple "truncation-trick" for improving few-shot multi-modal trajectory\nprediction performance. We show that PECNet improves state-of-the-art\nperformance on the Stanford Drone trajectory prediction benchmark by ~20.9% and\non the ETH/UCY benchmark by ~40.8%. Project homepage:\nhttps://karttikeya.github.io/publication/htf/\n

Adolescents ages 10-15 experience dramatic changes in their biological, cognitive, emotional, and social development as well as in their physical and social environments. These include the physiological and psychological changes associated with puberty; further development of the brain; changes in family, peer, and romantic relationships; and exposure to new societal and cultural influences. During this period, many adolescents also begin to use alcohol. Alcohol use during adolescence has adverse effects on the body and increases the risk of alcohol dependence later in life. To better understand why some children drink whereas others do not, researchers are examining nonspecific and alcohol-specific factors that put adolescents at risk for, or which protect them from, early alcohol use and its associated problems. Nonspecific risk factors include certain temperamental and personality traits, family factors, and nonnormative development. Examples of nonspecific protective factors include certain temperamental characteristics, religiosity, and parenting factors (e.g., parental nurturance and monitoring). Among the most influential alcohol-specific risk and protective factors are a family history of alcoholism and the influences of siblings and peers, all of which shape an adolescent's expectancies about the effects of alcohol, which in turn help determine alcohol use behaviors.