Bayesian anomaly detection methods for social networks

Learning the network structure of a large graph is computationally demanding, and dynamically monitoring the network over time for any changes in structure threatens to be more challenging still. This paper presents a two-stage method for anomaly detection in dynamic graphs: the first stage uses simple, conjugate Bayesian models for discrete time counting processes to track the pairwise links of all nodes in the graph to assess normality of behavior; the second stage applies standard network inference tools on a greatly reduced subset of potentially anomalous nodes. The utility of the method is demonstrated on simulated and real data sets.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS329 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

An on-board near-optimal climb-dash energy management

On-board real time flight control is studied in order to develop algorithms which are simple enough to be used in practice, for a variety of missions involving three dimensional flight. The intercept mission in symmetric flight is emphasized. Extensive computation is required on the ground prior to the mission but the ensuing on-board exploitation is extremely simple. The scheme takes advantage of the boundary layer structure common in singular perturbations, arising with the multiple time scales appropriate to aircraft dynamics. Energy modelling of aircraft is used as the starting point for the analysis. In the symmetric case, a nominal path is generated which fairs into the dash or cruise state. Feedback coefficients are found as functions of the remaining energy to go (dash energy less current energy) along the nominal path

Climb-dash real-time calculations

On-board rear-optimal climb-dash energy management, optimal symmetric flight with an intermediate vehicle model, and energy states are presented

Social Workers\u27 Perceptions of Family Preservation Programs

The passage of the Adoptions and Safe Families Act of 1997, with its focus on child safety and concurrent planning, has presented family preservation workers with new challenges and new opportunities. Twenty volunteers from a large comprehensive social service agency were interviewed to determine their experiences with two models of family preservation—Multisystemic Therapy (MST) and Traditional Family Preservation Service (TFPS) or practice as usual. Workers from both programs were able to articulate values consistent with family preservation as important strengths of the programs— keeping families together and empowering families for example. Information from referring agencies was described as variable and not especially useful when working with seriously troubled families, especially as it related to risk and child safety. Both groups indicated that the jargon of family preservation had permeated their agencies, and that working with other agencies was at times a challenge, though for different reasons. Finally, despite some reservations about the effectiveness of short-term treatment with families that face serious challenges, both groups of workers were generally satisfied with family preservation as an approach to practice

Amino acid transport in poky (mi) mutants of Neurospora crassa

Amino acid transport in pok

Computed tomography measures of nutrition in patients with end-stage liver disease provide a novel approach to characterize deficits

Aim Patients with cirrhosis and end-stage liver disease (ESLD) develop severe nutrition deficits that impact on morbidity and mortality. Laboratory measures of nutrition fail to fully assess clinical deficits in muscle mass and fat stores. This study employs computed tomography imaging to assess muscle mass and subcutaneous and visceral fat stores in patients with ESLD. Methods This 1:1 case-control study design compares ESLD patients with healthy controls. Study patients were selected from a database of ESLD patients using a stratified method to assure a representative sample based on age, body mass index (BMI), gender, and model for end-stage liver disease score (MELD). Control patients were trauma patients with a low injury severity score (<10) who had a CT scan during evaluation. Cases and controls were matched for age +/- 5 years, gender, and BMI +/- 2. Results There were 90 subjects and 90 controls. ESLD patients had lower albumin levels (p<0.001), but similar total protein levels (p=0.72). ESLD patients had a deficit in muscle mass (-19%, p<0.001) and visceral fat (-13%, p<0.001), but similar subcutaneous fat (-1%, p=0.35). ESLD patients at highest risk for sarcopenia included those over age 60, BMI< 25.0, and female gender. We found degree of sarcopenia to be independent of MELD score. Conclusions These results support previous research demonstrating substantial nutrition deficits in ESLD patients that are not adequately measured by laboratory testing. Patients with ESLD have significant deficits of muscle and visceral fat stores, but a similar amount of subcutaneous fat

Factors influencing the stable carbon isotopic composition of suspended and sinking organic matter in the coastal Antarctic sea ice environment

A high resolution time-series analysis of stable carbon isotopic signatures in particulate organic carbon (&amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt;) and associated biogeochemical parameters in sea ice and surface waters provides an insight into the factors affecting &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in the coastal western Antarctic Peninsula sea ice environment. The study covers two austral summer seasons in Ryder Bay, northern Marguerite Bay between 2004 and 2006. A shift in diatom species composition during the 2005/06 summer bloom to near-complete biomass dominance of &lt;i&gt;Proboscia inermis&lt;/i&gt; is strongly correlated with a large ~10 &amp;permil; negative isotopic shift in &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; that cannot be explained by a concurrent change in concentration or isotopic signature of CO&lt;sub&gt;2&lt;/sub&gt;. We hypothesise that the &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; shift may be driven by the contrasting biochemical mechanisms and utilisation of carbon-concentrating mechanisms (CCMs) in different diatom species. Specifically, very low &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in &lt;i&gt;P. inermis&lt;/i&gt; may be caused by the lack of a CCM, whilst some diatom species abundant at times of higher &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; may employ CCMs. These short-lived yet pronounced negative &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; excursions drive a 4 &amp;permil; decrease in the seasonal average &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; signal, which is transferred to sediment traps and core-top sediments and consequently has the potential for preservation in the sedimentary record. This 4 &amp;permil; difference between seasons of contrasting sea ice conditions and upper water column stratification matches the full amplitude of glacial-interglacial Southern Ocean &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; variability and, as such, we invoke phytoplankton species changes as a potentially important factor influencing sedimentary &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt;. We also find significantly higher &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in sea ice than surface waters, consistent with autotrophic carbon fixation in a semi-closed environment and possible contributions from post-production degradation, biological utilisation of HCO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt; and production of exopolymeric substances. This study demonstrates the importance of surface water diatom speciation effects and isotopically heavy sea ice-derived material for &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in Antarctic coastal environments and underlying sediments, with consequences for the utility of diatom-based &amp;delta;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;POC&lt;/sub&gt; in the sedimentary record