Developmental changes in foraging-predator avoidance trade-offs in larval lumpfish Cyclopterus lumpus

The 5-12 wk old larvae increased time spent clinging to a surface in the presence of a predator, trading-off time available for foraging in order to reduce the probability of attack. Overall, fewer fish fed in the presence of a predator, and of the fish that did feed, 12 wk old lumpfish also showed a significant decrease in feeding rate (bites per minute swimming) in the presence of a predator. -from Author

Inertial oscillations in an Ekman layer containing a horizontal discontinuity surface

Solutions are obtained for systems of equations that determine the development of velocity profiles in an infinitely deep fluid system subjected to Coriolis accelerations and composed of two layers of viscous fluid differing in density, viscosity, and geostrophic velocity. The density, viscosity, and horizontal pressure gradient are assumed to remain constant in space and time within each layer and to differ discontinuously at the horizontal interface between the layers...

Direct Laser Fabrication of a Gas Turbine Engine Component - Microstructure and Properties - Part I

This paper presents the development of a new technique for the production of abrasive turbine blade tips by direct laser processing. This superalloy cermet component is an integral part of the low pressure turbine sealing system in a demonstrator engine. Direct laser fabrication of this component fiom a bed a loose powder results in significant cost savings and improved performance over the currently employed production technique. The technology has been demonstrated by fabricating a prototype lot of 100 blade tips, which will be subjected to an engine test. This is the first instance of a direct fabrication method applied to the production of functional engine hardware. This research was funded by the United States Air Force contract F33615-94- C-2424 titled "Affordable Turbine Blade Tips".Mechanical Engineerin

Synthesis and characterization of biodegradable lignin nanoparticles with tunable surface properties

Lignin nanoparticles can serve as biodegradable carriers of biocidal actives with minimal environmental footprint. Here we describe the colloidal synthesis and interfacial design of nanoparticles with tunable surface properties using two different lignin precursors, Kraft (Indulin AT) lignin and Organosolv (high-purity lignin). The green synthesis process is based on flash precipitation of dissolved lignin polymer, which enabled the formation of nanoparticles in the size range of 45–250 nm. The size evolution of the two types of lignin particles is fitted on the basis of modified diffusive growth kinetics and mass balance dependencies. The surface properties of the nanoparticles are fine-tuned by coating them with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride). We analyze how the colloidal stability and dispersion properties of these two types of nanoparticles vary as a function of pH and salinities. The data show that the properties of the nanoparticles are governed by the type of lignin used and the presence of polyelectrolyte surface coating. The coating allows the control of the nanoparticles’ surface charge and the extension of their stability into strongly basic regimes, facilitating their potential application at extreme pH conditions

The Hydrodynamics Laboratory of the California Institute of Technology

This paper presents a description of the Hydrodynamics Laboratory and its principal pieces of equipment that have been developed during the last five years. The field of investigations to be undertaken by the Laboratory is presented in general terms

Termination of Parental Rights for Parents With Substance Use Disorder: For Whom and Then What?

The purpose of this study is to investigate the correlates of termination of parental rights (TPR) for parents with substance use disorder (SUD) and to determine what happens with regard to permanency once a TPR decision is made. Bivariate techniques and hierarchical non-linear modeling are used. Parents of older youth, boys, and Hispanics were less likely, while parents who failed to make progress in substance use treatment and parenting skills are more likely to experience TPR. At follow up, 85% of the children were adopted, 7% remained in a substitute care settings, and 7% were reunified with their parents. Concerns remain for children without a permanent home setting

Polarization Variability Arising from Clumps in the Winds of Wolf-Rayet Stars

The polarimetric and photometric variability of Wolf-Rayet (WR) stars as caused by clumps in the winds, is revisited. In the model which is improved from Li et al. 2000, the radial expansion of the thickness is accounted for, but we retain the dependence on the beta velocity law, stellar occultation effects. We again search for parameters that can yield results consistent with observations in regards to the mean polarization, the ratio of polarimetric to photometric variability, and the volume filling factor. Clump generation and spatial distribution are randomized by the Monte Carlo method so as to produce clumps which are, in the mean, distributed uniformly in space and have time intervals with a Gaussian distribution. The generated clumps move radially outward with a velocity law determined by a beta index, and the angular size of the clumps is assumed to keep fixed. By fitting the observational results and the volume filling factor, the clump velocity law index beta and clump ejection rate are inferred, and are found to be well constrained. In addition, the subpeak features on broad emission lines seem to support the clump ejection rate. Meanwhile, the fraction of the total mass loss rate that is contained in the clumps is obtained by fitting the observed polarization. We conclude that this picture for the clump properties produces a valuable diagnostic of WR wind structure.Comment: 28 pages, 13 figures, accepted for publication in RA

Weather, Crime, and Mental Illness

ABSTRACT - A simple count of disturbed incidents in the mentally ill and total radio transmissions of the Minneapolis Police Departmenf were collected daily over a six-month period. These were correlated with calendar time, temperature, humidity, and barometric pressure for the same period. Separate comparisons were made of all these measures for December 1959 with those of other Decembers. All the weather variables correlated linearly and significantly with the behavior v.ariables; temperature and humidity, positively; barometric pressure negatively. Calendar time for the half year correlated linearly and negatively. December 1959 had a higher crime and mental disturbance rate than other Decembers; this was accompanied by higher temperature and humidity

Cohomological finiteness conditions for a class of metabelian groups

We consider a class of metabelian groups first studied by Baumslag and Stammbach and we show that these groups are consistent with the Bieri-Groves conjecture which relates cohomological finiteness conditions to the Bieri-Neumann-Strebel sigma invariant.Comment: 10 pages Accepted for publication in the Bulletin of the London Mathematical Societ

6'-Methoxy Raloxifene-analog enhances mouse bone properties with reduced estrogen receptor binding

Raloxifene (RAL) is an FDA-approved drug used to treat osteoporosis in postmenopausal women. RAL suppresses bone loss primarily through its role as a selective estrogen receptor modulator (SERM). This hormonal estrogen therapy promotes unintended side effects, such as hot flashes and increased thrombosis risk, and prevents the drug from being used in some patient populations at-risk for fracture, including children with bone disorders. It has recently been demonstrated that RAL can have significant positive effects on overall bone mechanical properties by binding to collagen and increasing bone tissue hydration in a cell-independent manner. A Raloxifene-Analog (RAL-A) was synthesized by replacing the 6-hydroxyl substituent with 6-methoxy in effort to reduce the compound's binding affinity for estrogen receptors (ER) while maintaining its collagen-binding ability. It was hypothesized that RAL-A would improve the mechanical integrity of bone in a manner similar to RAL, but with reduced estrogen receptor binding. Molecular assessment showed that while RAL-A did reduce ER binding, downstream ER signaling was not completely abolished. In-vitro, RAL-A performed similarly to RAL and had an identical concentration threshold on osteocyte cell proliferation, differentiation, and function. To assess treatment effect in-vivo, wildtype (WT) and heterozygous (OIM+/-) female mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL or RAL-A from 8 weeks to 16 weeks of age. There was an untreated control group for each genotype as well. Bone microarchitecture was assessed using microCT, and mechanical behavior was assessed using 3-point bending. Results indicate that both compounds produced analogous gains in tibial trabecular and cortical microarchitecture. While WT mechanical properties were not drastically altered with either treatment, OIM+/- mechanical properties were significantly enhanced, most notably, in post-yield properties including bone toughness. This proof-of-concept study shows promising results and warrants the exploration of additional analog iterations to further reduce ER binding and improve fracture resistance