Sea Otter, Enhydra lutris, mortalities in California, 1968 through 1993

Sea otter, Enhydra lutris, mortality in California and the relative contribution from specific causes was assessed for the 26 years from 1968 through 1993. There were 2,082 dead sea otters recorded from Tomales Bay (Marin County) south to Bluff Cove (Los Angeles County) during that period. The average number of carcasses recorded was 80 per year and seven per month. Sex was identified in 87% (n=1,819) of the cases and was composed of 47% female and 53% male. A relative age was assigned to 97% (n=2,017) of the cases and was composed of 28% pup, 18% subadult and 54% adult. Specific causes of death were determined for 26% (n=55 1) of the cases. The majority of these (n=381) were considered to be due to natural causes and included the following specific causes: shark bitten (n=78), probably shark bitten (n=106), other natural causes (n=140), and mating wounds (n=57). The remaining (n=170) were considered to be due to human-related causes and included the following specific causes: shot (n=72), probably shot (n=8), net drowned (n=76), and other human causes (n=14). The large proportion of carcasses without an identified specific cause of death prompted a more detailed necropsy effort in 1992 and 1993. During that period, 78 of the 232 recovered carcasses were examined by veterinary pathologists and a specific cause of death was determined in 76% (n=59) of the cases. This effort identified a wide range of specific causes of death that otherwise may have been categorized as "unknown without trauma". Considering the variety of diseases diagnosed in this expanded necropsy program, it would be prudent to continue this level of examination to refine our knowledge of sea otter pathology. (48pp.

Treatment Outcomes for At-Risk Young Children With Behavior Problems: Toward a New Definition of Success

This study examined the outcomes of Early Pathways (EP), an in-home parent–child therapy program with 447 at-risk children younger than 5 years of age who were referred for severe behavior and emotional problems, such as aggression, oppositional behavior, and separation anxiety. EP emphasized parent-directed training of child behavior strategies including psychoeducation regarding child development, child-led play, and cognitive-behavioral techniques. Outcomes were assessed using a unique 2-dimensional definition of treatment completion, which consisted of treatment duration and an assessment of reliable change for the primary outcome measure of child behavior problems. Results showed that the majority of children (63.4%) met or exceeded treatment completion. In addition, repeated-measures multivariate analyses of variance at pretest, posttest, and follow-up revealed increased child prosocial behaviors, reduced child behavior problems, improved caregiver nurturing, an increase in parents’ developmentally appropriate expectations of children, improved parent–child relationships, and a decrease in clinical diagnoses following treatment. This study offers guidance for developing effective early-intervention services for families in poverty to enhance outcomes for their young children. Along with its existing large-scale, community-based effectiveness studies, future research should establish additional statistical support including a randomized, waitlist control design of EP

Efficient photon counting and single-photon generation using resonant nonlinear optics

The behavior of an atomic double lambda system in the presence of a strong off-resonant classical field and a few-photon resonant quantum field is examined. It is shown that the system possesses properties that allow a single-photon state to be distilled from a multi-photon input wave packet. In addition, the system is also capable of functioning as an efficient photodetector discriminating between one- and two-photon wave packets with arbitrarily high efficiency.Comment: 4 pages, 2 figure

Carbon Dioxide Sequestration to form Calcium Carbonate Nanoparticles

The emission of carbon dioxide caused by burning fossil fuels is one of the leading sources of global warming. Reducing the amount of CO2 released into the atmosphere through carbon sequestration can mitigate this problem. One method of carbon sequestration is the use of a carbon dioxide scrubber. Once captured, CO2 can be used to create a valuable chemical commodity such as calcium carbonate nanoparticles. To create CaCO3 particles in the 50-100 nanometer range, a chemical additive is necessary to limit particle size. The study used a laboratory scale carbon dioxide scrubber to react CO2 with calcium chloride and OH- ions to form calcium carbonate nanoparticles. Varying CaCl2 concentrations were tested as well as two chemical additives (AOT and PEG) in varying amounts. The resulting CaCO3 nanoparticles were analyzed to determine average particle size using dynamic light scattering. The study confirmed that the scrubber process effectively reduced CO2 released from the system. In general, larger quantities of additive led to smaller particles, but while AOT and PEG both limit CaCO3 particle size, AOT was the most effective. Unexpected results showed that larger concentrations of CaCl2 reduce the formation of bubble build-up in the reactor. Future work can be done to explore this effect of CaCl2 on sud formation by monitoring and recording bubble levels during the reaction

Simultaneous Modelling of the Stellar Halo and Globular Cluster System of NGC 5128

An important test for models of galaxy formation lies in the metallicity distribution functions (MDFs) of spheroid stars and their globular clusters (GCs).We have compared the MDFs obtained from spectroscopy of the GCs and the star-by-star photometry of red giants in the nearby elliptical NGC 5128, with the predictions of a semi-analytic galaxy formation model. We have selected model ellipticals comparable in luminosity and environment to NGC 5128, and derived their MDFs. A direct comparison between models and data shows that the MDFs are qualitatively similar, both have stellar components which are predominantly metal-rich (0.8Z), with a small fraction of metal-poor stars extending down to 0.002Z. The model MDFs show only small variations, whether they are brightest cluster galaxies or low luminosity group ellipticals. Our comparison also reveals that these model MDFs harbour a greater fraction of stars above solar metallicity than the observations, producing generally more metal-rich (by 0.1 dex) MDFs. One possibility is that the outer-bulge observations are missing some of the highest metallicity stars. We find good agreement between the model and observed GC MDFs, provided that the metal-poor GC formation is halted early in the model. Under this proviso, both the models and data are bimodal with peaks at 0.1Z and Z, and cover similar metallicity ranges. This broad agreement for the stars and GCs suggests that the bulk of the stellar population in NGC 5128 may have been built up in a hierarchical fashion, involving both quiescent and merger-induced star formation. The existence of age structure amongst the metal-rich GCs needs to be tested against high-quality data for this galaxy.Comment: 13 pages, 9 figures and a table, accepted by MNRA

The Kinematics and Dynamics of the Globular Clusters and the Planetary Nebulae of NGC 5128

A new kinematic and dynamic study of the halo of the giant elliptical galaxy, NGC 5128, is presented. From a spectroscopically confirmed sample of 340 globular clusters and 780 planetary nebulae, the rotation amplitude, rotation axis, velocity dispersion, and the total dynamical mass are determined for the halo of NGC 5128. The globular cluster kinematics were searched for both radial dependence and metallicity dependence by subdividing the globular cluster sample into 158 metal-rich ([Fe/H] > -1.0) and 178 metal-poor ([Fe/H] < -1.0) globular clusters. Our results show the kinematics of the metal-rich and metal-poor subpopulations are quite similar. The kinematics are compared to the planetary nebula population where differences are apparent in the outer regions of the halo. The total mass of NGC 5128 is found using the Tracer Mass estimator (Evans et al. 2003), to determine the mass supported by internal random motions, and the spherical component of the Jeans equation to determine the mass supported by rotation. We find a total mass of (1.0+/-0.2) x 10^(12) Msun from the planetary nebulae data out to a projected radius of 90 kpc and (1.3+/-0.5) x 10^(12) Msun from the globular clusters out to a projected radius of 50 kpc. Lastly, we present a new and homogeneous catalog of known globular clusters in NGC 5128. This catalog combines all previous definitive cluster identifications from radial velocity studies and HST imaging studies, as well as 80 new globular clusters from a study of M.A. Beasley et al. (2007, in preparation).Comment: Accepted in the Astronomical Journal,52 pages, 13 figures, 6 tables - Changes made to Table 1 from originally submitted 0704.118