Evolutionary tree reconstruction

It is described how Minimum Description Length (MDL) can be applied to the problem of DNA and protein evolutionary tree reconstruction. If there is a set of mutations that transform a common ancestor into a set of the known sequences, and this description is shorter than the information to encode the known sequences directly, then strong evidence for an evolutionary relationship has been found. A heuristic algorithm is described that searches for the simplest tree (smallest MDL) that finds close to optimal trees on the test data. Various ways of extending the MDL theory to more complex evolutionary relationships are discussed

Perceived Locus of Control in the Children of Military and Civilian Families Affected By Deployment and Divorce

This study was designed to explore the differences between locus of control (LOC) in children from civilian and military families and to investigate whether military deployment is associated with an external locus of control. Existing literature has focused on the negative implications of external LOC for children\u27s mental health and achievement. However, research regarding this construct related to children of military families has not been conducted. In the present study, LOC was measured by the Nowicki-Strickland Locus of Control Scale for Children, designed for individuals from the 3rd to the 12th grade. The 54 participants in this study ranged in age from 7 to 17 and came from either a military family with a deployed parent, a civilian family with two caregivers in the home, or a divorced/separated civilian family. After conducting a univariate one-way ANOVA on the data, it was found that children of deployed military families did not score significantly different for mean locus of control than civilian separated/divorced families, or civilian intact families. A correlation comparing age and LOC scores likewise found no significant relationship

Sexual Orientation and the Disclosure of Unwanted Sexual Experiences

Individuals who identify as lesbian, gay, bisexual, questioning, and other non-heterosexual orientations (LGBQ+) are significantly more likely to experience a sexual assault. To date, research on barriers to sexual assault disclosure (i.e., telling someone about a sexual assault) has been conducted almost exclusively on heterosexual women. Participants ages 18 to 30 participated in a cross-sectional, online study that assessed unwanted sexual experiences, disclosure of those experiences, perceptions of the police and perceptions of belonging to the LGBQ+ community. Findings demonstrated that survivors who identified as LGBQ+ took longer to initially disclose their sexual assault and had greater negative perceptions of police than survivors who identified as heterosexual. Also, among survivors who identified as LGBQ+, the degree of outness of sexual orientation was positively associated with sexual assault disclosure. However, perceptions of the police were not associated with disclosure of sexual assault to the police among people who identified as LGBQ+. Perceptions of belonging to the LGBQ+ community were also not associated with disclosure likelihood. The results of this study help to better understand how the sexual assault disclosure process differs by sexual orientation and suggest that providers who work with survivors who identify as LGBQ+ need to keep in mind the unique concerns faced by survivors who identify as LGBQ+ who may be considering disclosing their trauma. These findings also call attention to the negative perceptions of police that continue to be held by people who identify as LGBQ+. Due to limited research on the topic of sexual assault and the LGBQ+ community, this study may encourage future researchers to examine additional barriers to sexual assault disclosure that may be unique for survivors who identify as LGBQ+ and how disclosure is received by both formal and informal support

Perceived Locus of Control in the Children of Military and Civilian Families Affected by Deployment and Divorce

This study was designed to explore the differences between locus of control (LOC) in children from civilian and military families and to investigate whether military deployment is associated with an external locus of control more than other family dynamics. The literature has focused on the negative implications of external LOC for children’s mental health and achievement as well as in childhood chronic illness, parental absence, and parental alcoholism. However, prior research regarding this construct related to children of military families is significantly lacking. In the present study, LOC was measured by the Nowicki-Strickland Locus of Control Scale for Children, a 40 question scale designed for individuals within the range of 3rd to 12th grade. The 54 participants in this study ranged in age from 7 to 17 and came from either a military family with a deployed parent, a civilian family with two caregivers in the home, or a divorced - separated civilian family. A univariate one-way ANOVA was conducted on the data. It was found that children of deployed military families did not score significantly different for mean locus of control than civilian separated/divorced families, or civilian intact families. A correlation comparing age and LOC scores found no significant relationship. Limitations of this study included a small sample size due to time restrictions, and subsequently reduced statistical power. Future investigations into LOC should continue to explore its relationship with children in military families, as future studies correcting for sampling may obtain significant results. Further research should also probe more deeply into the negative and positive consequences that external and internal attributional tendencies may have for children’s development, academic performance, and overall well-being

Subpixel resolution from multiple images

Multiple images taken from similar locations and under similar lighting conditions contain similar, but not identical, information. Slight differences in instrument orientation and position produces mismatches between the projected pixel grids. These mismatches ensure that any point on the ground is sampled differently in each image. If all the images can be registered with respect to each other to a small fraction of a pixel accuracy, then the information from the multiple images can be combined to increase linear resolution by roughly the square root of the number of images. In addition, the gray-scale resolution of the composite image is also improved. We describe methods for multiple image registration and combination, and discuss some of the problems encountered in developing and extending them. We display test results with 8:1 resolution enhancement, and Viking Orbiter imagery with 2:1 and 4:1 enhancements

Playbook Data Analysis Tool: Collecting Interaction Data from Extremely Remote Users

Typically, user tests for software tools are conducted in person. At NASA, the users may be located at the bottom of the ocean in a pressurized habitat, above the atmosphere in the International Space Station, or in an isolated capsule on a simulated asteroid mission. The Playbook Data Analysis Tool (P-DAT) is a human-computer interaction (HCI) evaluation tool that the NASA Ames HCI Group has developed to record user interactions with Playbook, the group's existing planning-and-execution software application. Once the remotely collected user interaction data makes its way back to Earth, researchers can use P-DAT for in-depth analysis. Since a critical component of the Playbook project is to understand how to develop more intuitive software tools for astronauts to plan in space, P-DAT helps guide us in the development of additional easy-to-use features for Playbook, informing the design of future crew autonomy tools.P-DAT has demonstrated the capability of discreetly capturing usability data in amanner that is transparent to Playbooks end-users. In our experience, P-DAT data hasalready shown its utility, revealing potential usability patterns, helping diagnose softwarebugs, and identifying metrics and events that are pertinent to Playbook usage aswell as spaceflight operations. As we continue to develop this analysis tool, P-DATmay yet provide a method for long-duration, unobtrusive human performance collectionand evaluation for mission controllers back on Earth and researchers investigatingthe effects and mitigations related to future human spaceflight performance

Carotid Artery Aneurysm: A Case Study

A 60 year old male arrived at the emergency department after losing consciousness. CT showed he demonstrated a right hemispheric embolic stroke with a middle cerebral artery distribution. Upon further investigation, the patient was found to have a right common carotid artery aneurysm that extended about 1 cm from the carotid bifurcation into the internal carotid artery. The patient underwent carotid artery reconstruction with the use of his right great saphenous vein. This case demonstrates an unusual form of cerebral embolization due to a internal carotid artery aneurysm

Elevated tau and interleukin-6 concentrations in adults with obstructive sleep apnea

The article of record as published may be found at http://dx.doi.org/10.1016/j.sleep.2017.11.1121Obstructive sleep apnea (OSA) is characterized by apneas and hypopneas that result in hypoxia, cerebral hypoperfusion, endothelial dysfunction, inflammation, and oxidative stress. These pathophysiologic processes likely contribute to neuronal damage. Tau is a protein that stabilizes microtubules and, along with amyloid beta (Ab), is associated with neurodegenerative processes. We sought to determine if tau and other biomarkers of inflammation were related to OSA severity. Concentrations of tau, Ab40, Ab42, c-reactive protein (CRP), TNF-a, interleukin (IL)-6, and IL-10 were measured in blood and compared between participants with moderate-severe OSA (n 1⁄4 28), those with mild OSA (n 1⁄4 22), and healthy controls (n 1⁄4 24). The cohort included relatively young, primarily male active duty military personnel without a history of traumatic brain injury or neurodegenerative disease. Total biomarker concentrations were determined from plasma samples using an ultra-sensitive detection method, SimoaTM, and CRP was assayed by ELISA. Total tau and IL-6 concentrations were elevated in participants with moderate-severe OSA, with a mean apnea-hypopnea index (AHI) of 26.1/h, compared to those with mild OSA (mean AHI 8.6/h) and healthy controls (mean AHI 2.1/h). Tau concentrations were also significantly correlated with the AHI (r 1⁄4 0.342, p 1⁄4 0.004). Our findings show that tau is elevated in the blood of young patients with moderate-severe OSA, suggesting that this degree of sleep-disordered breathing is a contributing factor in the development of neurodegenerative disorders. The finding of increased IL-6 further suggests that inflammatory biomarkers are present early in the course of this chronic disease

The centred travelling salesman at high temperature

A recently formulated statistical mechanics method is used to study the phase transition occurring in a generalisation of the Traveling Salesman Problem (TSP) known as the centred TSP. The method shows that the problem has clear signs of a crossover, but is only able to access (unscaled) finite temperatures above the transition point. The solution of the problem using this method displays a curious duality