The effects of video compression on acceptability of images for monitoring life sciences experiments

Future manned space operations for Space Station Freedom will call for a variety of carefully planned multimedia digital communications, including full-frame-rate color video, to support remote operations of scientific experiments. This paper presents the results of an investigation to determine if video compression is a viable solution to transmission bandwidth constraints. It reports on the impact of different levels of compression and associated calculational parameters on image acceptability to investigators in life-sciences research at ARC. Three nonhuman life-sciences disciplines (plant, rodent, and primate biology) were selected for this study. A total of 33 subjects viewed experimental scenes in their own scientific disciplines. Ten plant scientists viewed still images of wheat stalks at various stages of growth. Each image was compressed to four different compression levels using the Joint Photographic Expert Group (JPEG) standard algorithm, and the images were presented in random order. Twelve and eleven staffmembers viewed 30-sec videotaped segments showing small rodents and a small primate, respectively. Each segment was repeated at four different compression levels in random order using an inverse cosine transform (ICT) algorithm. Each viewer made a series of subjective image-quality ratings. There was a significant difference in image ratings according to the type of scene viewed within disciplines; thus, ratings were scene dependent. Image (still and motion) acceptability does, in fact, vary according to compression level. The JPEG still-image-compression levels, even with the large range of 5:1 to 120:1 in this study, yielded equally high levels of acceptability. In contrast, the ICT algorithm for motion compression yielded a sharp decline in acceptability below 768 kb/sec. Therefore, if video compression is to be used as a solution for overcoming transmission bandwidth constraints, the effective management of the ratio and compression parameters according to scientific discipline and experiment type is critical to the success of remote experiments

A study of video frame rate on the perception of moving imagery detail

The rate at which each frame of color moving video imagery is displayed was varied in small steps to determine what is the minimal acceptable frame rate for life scientists viewing white rats within a small enclosure. Two, twenty five second-long scenes (slow and fast animal motions) were evaluated by nine NASA principal investigators and animal care technicians. The mean minimum acceptable frame rate across these subjects was 3.9 fps both for the slow and fast moving animal scenes. The highest single trial frame rate averaged across all subjects for the slow and the fast scene was 6.2 and 4.8, respectively. Further research is called for in which frame rate, image size, and color/gray scale depth are covaried during the same observation period

Children\u27s Exposure to Intimate Partner Violence and Other Family Violence.

Explores in depth the survey results from the National Survey of Children\u27s Exposure to Violence (NatSCEV) regarding exposure to family violence among children in the United States, including exposure to intimate partner violence, assaults by parents on siblings of children surveyed, and other assaults involving teen and adult household members. These results confirm that children are exposed to unacceptable rates of violence in the home. The bulletin presents information regarding the types of exposure to family violence, the gender of the perpetrator, the relationship of the child witness to the perpetrator, and youth\u27s reactions to the incident. It also discusses the implications of the survey data for researchers, practitioners, and policymakers and makes policy recommendations, including better screening protocols for exposure to family violence, improved interventions for those exposed, increased coordination of services for adult and child victims of family violence, and more prevention and education programs to reduce family violence. This is the second in a series of bulletins that present findings from NatSCEV, the most comprehensive nationwide survey to date of the incidence and prevalence of children’s exposure to violence across all ages, settings, and timeframes

Polyvictimization: Children\u27s Exposure to Multiple Types of Violence, Crime, and Abuse.

Presents the findings of the National Survey of Children\u27s Exposure to Violence (NatSCEV) regarding children\u27s direct exposure to multiple types of violence, crime, and abuse, also known as polyvictimization. Children and youth who are exposed to multiple types of violence are at particularly high risk for lasting physical, mental, and emotional harm, even compared with children who experience repeated exposures to a single type of violence. Among the key findings: 8 percent of all youth in the nationally representative NatSCEV sample had seven or more different kinds of exposures to violence, crime, and abuse in the past year. These youth also had a disproportionate share of the most serious kinds of victimizations, such as sexual victimization and parental maltreatment. Polyvictimization was most likely to start near the beginning of grade school and the beginning of high school and tended to persist over time. It was associated with a cluster of four prior circumstances or pathways: living in a violent family, living in a distressed and chaotic family, living in a violent neighborhood, and having preexisting psychological symptoms. In addition, polyvictims are overrepresented among certain demographic groups, including boys, African American children, and children in single-parent, stepparent, and other adult caregiver families. This is the third in a series of bulletins that present findings from NatSCEV, the most comprehensive nationwide survey to date of the incidence and prevalence of children\u27s exposure to violence across all ages, settings, and timeframes

Child and Youth Victimization Known to Police, School, and Medical Authorities.

Presents the survey results from the National Survey of Children\u27s Exposure to Violence (NatSCEV) regarding authorities\u27 knowledge of victimization incidents involving children and youth, particularly police, school, and medical authorities. Compared with a similar study in the early 1990s, the survey found that authorities were more likely to know about NatSCEV survey participants\u27 exposure to violence, which may reflect efforts by authorities, criminal justice and child protection agencies, and advocates to promote disclosure. This increase in disclosure is also consistent with the decrease in child victimizations during the last two decades. The survey found that 46 percent of children who were victimized in the previous year had at least one victimization known to school, police, and medical authorities, with school authorities (e.g., teachers, principals, and counselors) being the most likely to know of the victimizations. However, police were most likely to know about many of the most serious victimizations. In general, authorities were most likely to know about serious victimizations, including sexual abuse by an adult, kidnapping, and gang or group assaults. They were least likely to know about victimizations committed by other youth, including peer and sibling assaults, dating violence, flashing, and completed or attempted rate. This bulletin also discusses factors that promote or hinder disclosure of victimization incidents to authorities, and the implications of the increase in disclosure for prevention and treatment. This is the fourth in a series of bulletins that present findings from NatSCEV, the most comprehensive nationwide survey to date of the incidence and prevalence of children’s exposure to violence across all ages, settings, and timeframes

Predicting Optimal Targeting Strategies in Multispecies Fisheries: A Portfolio Approach

When regulations are species specific but the species are part of a multispecies fishery, studies show that harvest rates are correlated such that net revenues attributed to each species are also correlated. This correlation suggests that portfolio theory is well suited for multispecies fisheries that exhibit joint productive characteristics. This paper uses a portfolio approach to model the behavior of fishermen faced with multiple targeting options in a random harvest fishery. The approach draws from the expected utility hypothesis and financial portfolio theory to predict optimal targeting strategies. The methodology is applied to the pelagic longline fleet operating in the U.S. Atlantic Ocean, Caribbean, and Gulf of Mexico. The model provides evidence that area closures aimed at reducing juvenile swordfish mortality will be more effective in certain regions. Efficient risk-return frontiers are also generated for use in predicting targeting behavior in lieu of a closure.fisheries economics, fisheries management, highly migratory species, multispecies fisheries, portfolio theory, swordfish, targeting strategies, Resource /Energy Economics and Policy, Q22, G11, D81, C61,

Energy transitions, sub-national government and regime flexibility : how has devolution in the United Kingdom affected renewable energy development?

We acknowledge the support of the Economic and Social Research Council for funding the research on which this paper was based (Grant Number RES-062-23-2526).Peer reviewedPostprin

Tobacco Cessation Treatments Among Young Adult Smokers

Summarizes a study of differences between younger and older adult smokers in their motivations and attempts to quit and their use of smoking cessation treatments. Compares data by demographics, education, health insurance status, and other factors

Response of Eelgrass Zostera marina to CO2 Enrichment: Possible Impacts of Climate Change and Potential for Remediation of Coastal Habitats

Projected increases in dissolved aqueous concentrations of carbon dioxide [CO2(aq)] may have significant impacts on photosynthesis Of CO2-limited organisms such as seagrasses. Short-term CO2(aq) enrichment increases photosynthetic rates and reduces light requirements for growth and survival of individual eelgrass Zostera marina L. shoots growing in the laboratory under artificial light regimes for at least 45 d. This study examined the effects of long-term CO2(aq) enrichment on the performance of eelgrass growing under natural light-replete (33% surface irradiance) and light-limited (5% surface irradiance) conditions for a period of 1 yr. Eelgrass shoots were grown at 4 CO2(aq) concentrations in outdoor flow-through seawater aquaria bubbled with industrial flue gas containing approximately 11% CO2. Enrichment with CO2(aq) did not alter biomass-specific growth rates, leaf size, or leaf sugar content of above-ground shoots in either light treatment. CO2(aq) enrichment, however, led to significantly higher reproductive output, below-ground biomass and vegetative proliferation of new shoots in light-replete treatments. This suggests that increasing the CO2 content of the atmosphere and ocean surface will increase the area-specific productivity of seagrass meadows. CO2(aq) enrichment did not affect the performance of shoots grown under light limitation, suggesting that the transition from carbon- to light-limited growth followed Liebig\u27s Law. This study also demonstrated that direct injection of industrial flue gas could significantly increase eelgrass productivity; this might prove useful for restoration efforts in degraded environments. The broader effects Of CO2(aq) enrichment on the function of natural seagrass meadows, however, require further study before deliberate CO2 injection could be considered as an engineering solution to the problem of seagrass habitat degradation

Assessing Population Trends of New-Hampshire Forest Birds: Local vs Regional Patterns

We examined the changes in abundance between 1969 and 1986 of 19 forest-dwelling, mostly migratory bird species breeding in New Hampshire at 2 different scales: one local (an intensively studied 10-ha plot in unfragmented forest) and the other regional (Breeding Bird Surveys statewide). Twelve of the 19 species exhibited similar trends at both scales. Eight neither increased nor decreased, and 4 (Least Flycatcher, Winter Wren, Wood Thrush, and Swainsoh\u27s Thrush) declined significantly. Others increased, decreased, or re-mained steady at one or the other scale. Overall, more species declined than increased both locally (8 vs. 1) and regionally (5 vs. 1). Comparisons of these patterns, combined with results of intensive studies at the local level, suggest that changes in food abundance and in vege-tation structure related to forest succession on the breeding grounds, along with other pro-cesses that influence bird reproductive success and survivorship, are the most plausible explanations for most of the observed trends. Winter mortality was also identified as affecting breeding abundances, but only in short-distance migrant and permanently resident species. We have no evidence to indicate that the numbers of long-distance migrants were affected by events in their Neotropical wintering areas, although this possibility is difficult to assess from breeding-ground data. We urge caution in attributing declines of breeding forest migrant birds to tropical deforestation or similar causes until we either can eliminate alternate explanations that involve breeding-season events or have available critically needed demo-graphic information on migrant populations in their wintering areas