Defense against node compromise in sensor network security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

Two -way direction of influence in mother-infant interaction as denoted by concurrent reciprocal learning processes

This series of 5 single-subject studies used the operant conditioning paradigm to investigate, within the two-way influence process, how (a) contingent infant attention can reinforce maternal verbal behaviors during a period of mother-infant interaction and under subsequent experimental manipulation. Differential reinforcement was used to determine if it is possible that an infant attending to the mother (denoted by head-turns towards the image of the mother plus eye contact) increases (reinforces) the mother's verbal response (to a cue from the infant) upon which the infant behavior is contingent. There was also (b) an evaluation during the contrived parent-infant interaction for concurrent operant learning of infant vocal behavior via contingent verbal responding (reinforcement) implemented by the mother. Further, it was noted (c) whether or not the mother reported being aware that her responses were influenced by the infant's behavior. Findings showed: the operant conditioning of the maternal verbal behaviors were reinforced by contingent infant attention; and the operant conditioning of infant vocalizations was reinforced by contingent maternal verbal behaviors. No parent reported (1) being aware of the increase in their verbal response reinforced during operant conditioning of parental behavior nor a decrease in those responses during the DRA reversal phase, or (2) noticing a contingency between infant's and mother's response. By binomial 1-tail tests, the verbal-behavior patterns of the 5 mothers were conditioned by infant reinforcement (p < 0.02) and, concurrently, the vocal-response patterns of the 5 infants were conditioned by maternal reinforcement (p < 0.02). A program of systematic empirical research on the determinants of concurrent conditioning within mother-child interaction may provide a way to evaluate the differential effectiveness of interventions aimed at improving parent-child interactions. The work conducted in the present study is one step in this direction. ^

Defense Against Node Compromise in Sensor Network Security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

Adult education directors' perceptions of performance indicators for adult education programs in the state of Florida

Current demands for accountability in education emphasize outcome-based program evaluation and tie program funding to individual student performance. As has been the case for elementary and secondary programs, demands for accountability have increased pressure on adult educators to show evidence of the benefits of their programs in order to justify their financial support. In Florida, recent legislation fundamentally changes the delivery of adult education in the state by establishing a performance-based funding system that is based on outcomes related to the retention, completion, and employment of program participants.^ A performance-based funding system requires an evaluation process that stresses outcome indicators over indicators that focus on program context or process. Although the state has adopted indicators of program quality to evaluate its adult education programs, these indicators focus mostly on program processes rather than student outcomes. In addition, the indicators are not specifically tied to workforce development outcomes, a priority to federal and local funding agents.^ Improving the accountability of adult education programs and defining the role of these programs in Florida's Workforce Development System has become a priority to policy makers across the state. Another priority has been to involve adult education practitioners in every step of this process.^ This study was conducted in order to determine what performance indicators, as judged by the directors and supervisors of adult education programs in the state of Florida, are important and feasible in measuring the quality and effectiveness of these programs. The results of the study indicated that, both statewide and by region, the respondents consistently gave the highest ratings on both importance and feasibility to the indicators of Program Context, which reflect the needs, composition, and structure of the programs, and to the indicators of Educational Gain, which reflect learner progress in the attainment of basic skills and competencies. In turn, the respondents gave the lowest ratings on both importance and feasibility to the indicators in the areas of Return on State's Investment, Efficiency, Retention, and Workforce Training. In general, the indicators that received high ratings for importance also received high ratings for feasibility. ^

Health care utilization behavior of elders in a multicultural urban environment

The objective of this research is to determine the influences of social, environmental, behavioral, and economic forces on the health care service utilization of four racial/ethnic groups of non-institutionalized elders in a multicultural urban environment. To address these issues this dissertation examines three intertwined themes of culture, aging, and health, using a sample of elders residing in Miami-Dade County, FL in four racial/ethnic groups: white non-Hispanic; black non-Hispanic English speakers; Cuban; and non-Cuban Hispanic. ^ The research questions were analyzed using both quantitative and qualitative data. Data for the quantitative component uses telephone survey data from the Dade County Needs Assessment. The purpose of this component is to develop a more comprehensive model of elder health care utilization behavior. The qualitative component uses data from focus groups from Dade County Needs Assessment, archival data and a literature review of previous ethnographic research. The purpose of this component is to gain a better understanding of the social construction of the terms “age”' and “aging,” as well as to place issues of health and health care in the lives of elders. ^ The findings raised several important issues. First, just because people share a common chronological age does not mean that they are the same in every other respect. Examining elders as a homogeneous group of users of formal health care services in a community is simplistic. Placing “aging” and “health” in a cultural context is important. My findings confirm that the meaning of “aging” and “old” are socially constructed. Further, the term “aging” is NOT synonymous with ill health or frailty. This was a consistent finding in both the quantitative and qualitative results. ^ While all aging individuals share a mutual orientation toward aging (i.e., biological process), they do not age the same way (i.e., social construction of “aging”). Thus, policymakers and others serving the elder population must be aware of the particular cultural context, as well as the previous life experiences of the individuals that they serve. This analysis documents the importance of culture and geographic community in understanding health care service utilization of elders. ^

The multiple dimensions of political trust in democratic Argentina

Why do Argentines continue to support democracy despite distrusting political institutions and politicians? Support for democracy is high even though performance of the regime is poor. One would suspect that poor economic and political performance would open the door for military intervention given the history of Argentina. What changed? What explains variance across the multiple dimensions of political trust, such as trust in the regime, trust in political institutions, and trust in politicians? This dissertation is a case study of political culture through public opinion exploring the multiple dimensions of political trust in Argentina during the 1990s. ^ Variance across the different dimensions of political trust may be an indicator of the rise of a new type of citizens called "critical citizens." Critical citizens are citizens who criticize the regime to obtain democratic reforms but support the ideals of democracy. In established democracies, the rise of critical citizens is explained by a shift in individuals' value priorities towards postmaterialism. Postmaterialism is a cultural change in the direction of values that emphasize self-realization and individual well-being. Postmaterialism influences various social and political attitudes. ^ Because Argentina is experiencing a cultural change and a rise of critical citizens similar to more advanced societies, the theory of postmaterialism generated the main hypothesis to explain the multiple dimensions of political trust. This dissertation also tested an alternative explanation: the multiple dimensions of political trust responded instead to citizens' evaluations of performance. Ultimately, postmaterialism explained trust in the political regime and trust in the political institutions. Contrary to expectations, postmaterialism did not explain trust in the political elites or politicians. Trust in politicians was better explained by the alternative hypothesis, performance. ^ The main method of research was the statistical method supplemented with the comparative method when data were available. Two main databases were used: the World Values Surveys and the Latinobarometer. ^

Evaluating the impacts of Bolsa Escola programs on student performance in Brazil

Since the 1980s, governments and organizations have promoted cash transfers in education as a tool for motivating elementary aged children to attend school. Oftentimes, the monthly payments supplemented the income a child would be making in the labor market. In Brazil, where these Bolsa or grant programs were pioneered, there has been much success in removing children from harsh labor conditions and increasing enrollment rates among the poorest families. However, the capacity of Bolsa Escola programs to meet other objectives, such as impacting educational outcomes and reducing incidences of poverty, continues to be examined. As these programs continue to be adopted globally, funding millions of children and families, evidence that demonstrates such success becomes ever more imperative. This study, therefore, examined evidence to determine whether Bolsa Escola programs have a significant impact on the academic performance of beneficiaries in Brazil. ^ Through the course of three data collection phases, multiple data sources were used to demonstrate the academic performance of fourth and eighth grade Brazilian students who were eligible to participate in either an NGO or the federal cash transfer program. MANOVAs were conducted separately for fourth and eighth grade data to determine if significant differences existed between measures of academic performance of Bolsa and non-Bolsa students. In every case and for both grade levels, significant effects were found for participation. ^ The limited qualitative data collected did not support drawing conclusions. Thematic analysis of the limited interview data pointed to possible dependency on Bolsa monthly stipends, and reallocation of responsibilities in the home in cases where children shifted from being breadwinners to students. ^

Fish population dynamics in a seasonally varying wetland

Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the ‘reaction–diffusion’ mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction–diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first—the ‘refuge mechanism’—hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the ‘dynamic ideal free distribution mechanism’ is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.

Chilling damage in a changing climate in coastal landscapes of the subtropical zone: a case study from south Florida

Extensive portions of the southern Everglades are characterized by series of elongated, raised peat ridges and tree islands oriented parallel to the predominant flow direction, separated by intervening sloughs. Tall herbs or woody species are associated with higher elevations and shorter emergent or floating species are associated with lower elevations. The organic soils in this “Ridge-and-Slough” landscape have been stable over millennia in many locations, but degrade over decades under altered hydrologic conditions. We examined soil, pore water, and leaf phosphorus (P) and nitrogen (N) distributions in six Ridge and Slough communities in Shark Slough, Everglades National Park. We found P enrichment to increase and N to decrease monotonically along a gradient from the most persistently flooded sloughs to rarely flooded ridge environments, with the most dramatic change associated with the transition from marsh to forest. Leaf N:P ratios indicated that the marsh communities were strongly P-limited, while data from several forest types suggested either N-limitation or co-limitation by N and P. Ground water stage in forests exhibited a daytime decrease and partial nighttime recovery during periods of surface exposure. The recovery phase suggested re-supply from adjacent flooded marshes or the underlying aquifer, and a strong hydrologic connection between ridge and slough. We therefore developed a simple steady-state model to explore a mechanism by which a phosphorus conveyor belt driven by both evapotranspiration and the regional flow gradient can contribute to the characteristic Ridge and Slough pattern. The model demonstrated that evapotranspiration sinks at higher elevations can draw in low concentration marsh waters, raising local soil and water P concentrations. Focusing of flow and nutrients at the evapotranspiration zone is not strong enough to overcome the regional gradient entirely, allowing the nutrient to spread downstream and creating an elongated concentration plume in the direction of flow. Our analyses suggest that autogenic processes involving the effects of initially small differences in topography, via their interactions with hydrology and nutrient availability, can produce persistent physiographic patterns in the organic sediments of the Everglades.

Acute Posterior Ankle Pain in a Female Recreational Soccer Player

Os trigonum syndrome, a musculoskeletal disorder causing posterior ankle pain, occurs in approximately one in every 13 people. This condition can be challenging for the athletic trainer when evaluating an acute ankle injury. We present a unique case of an os trigonum successfully treated with conservative rehabilitation without a definitive diagnosis.

Process of privatization: Benefits of *reform in management of public housing

The study of the private management of public housing is an important topic to be critically analyzed as the government search for ways to increase efficiency in providing housing for the poor. Public Housing Authorities must address the cost for repairing or replacing the deteriorating housing stock, the increase in the need for affordable housing, and the lack of supply. There is growing pressure on efficient use of public funds that has heightened the need for profound structural reform. An important strategy for carrying out such reform is through privatization. Although privatization does not work in every case, the majority position in the traditional privatization literature is that reliance on private organizations normally, but not always, results in cost savings. ^ The primary purpose of this dissertation is to determine whether a consensus exist among decision-makers on the efficiency of privatizing the management of public housing. A secondary purpose is to review the techniques (best practices) used by the private sector that results in cost-efficiencies in the management of public housing. The study employs the use of a triangulated research design utilizing cross-sectional survey methodology that included use of a survey instrument to solicit responses from the private managers. The study consists of qualitative methods using interviews from key informants of private-sector management firms and public housing agencies, case studies, focus groups, archival records and housing authorities documents. ^ Results indicated that important decision-makers perceive that private managers made a positive contribution to cost-efficiencies in the management of public housing. The performance of private contractors served as a yardstick for comparison of efficiency of services that are produced in-house. The study concluded that private managers made the benefits of their management techniques well known creating a sense of competition between public and private managers. Competition from private contractors spurred municipal worker and management productivity improvements creating better management results for the public housing authorities. The study results are in concert with a review of recent research and studies that also concluded private managers have some distinct advantages to controlling costs in the management of public housing. ^

Three essays on market depth in futures markets

Liquidity is an important market characteristic for participants in every financial market. One of the three components of liquidity is market depth. Prior literature lacks a comprehensive analysis of depth in U.S. futures markets due to past limitations on the availability of data. However, recent innovations in data collection and dissemination provide new opportunities to investigate the depth dimension of liquidity. In this dissertation, the Chicago Mercantile Exchange (CME) Group proprietary database on depth is employed to study the dynamics of depth in the U.S. futures markets. This database allows for the analysis of depth along the entire limit order book rather than just at the first level. The first essay examines the characteristics of depth within the context of the five-deep limit order book. Results show that a large amount of depth is present in the book beyond the best level. Furthermore, the findings show that the characteristics of five-deep depth between day and night trading vary and that depth is unequal across levels within the limit order book. The second essay examines the link between the five-deep market depth and the bid-ask spread. The results suggest an inverse relation between the spread and the depth after adjusting for control factors. The third essay explores transitory volatility in relation to depth in the limit order book. Evidence supports the relation between an increase in volatility and a subsequent decrease in market depth. Overall, the results of this dissertation are consistent with limit order traders actively managing depth along the limit order book in electronic U.S. futures markets.

Development of a Lab-on-a-Chip Device for Rapid Nanotoxicity Assessment In Vitro

Increasing useof nanomaterials in consumer products and biomedical applications creates the possibilities of intentional/unintentional exposure to humans and the environment. Beyond the physiological limit, the nanomaterialexposure to humans can induce toxicity. It is difficult to define toxicity of nanoparticles on humans as it varies by nanomaterialcomposition, size, surface properties and the target organ/cell line. Traditional tests for nanomaterialtoxicity assessment are mostly based on bulk-colorimetric assays. In many studies, nanomaterials have found to interfere with assay-dye to produce false results and usually require several hours or days to collect results. Therefore, there is a clear need for alternative tools that can provide accurate, rapid, and sensitive measure of initial nanomaterialscreening. Recent advancement in single cell studies has suggested discovering cell properties not found earlier in traditional bulk assays. A complex phenomenon, like nanotoxicity, may become clearer when studied at the single cell level, including with small colonies of cells. Advances in lab-on-a-chip techniques have played a significant role in drug discoveries and biosensor applications, however, rarely explored for nanomaterialtoxicity assessment. We presented such cell-integrated chip-based approach that provided quantitative and rapid response of cellhealth, through electrochemical measurements. Moreover, the novel design of the device presented in this study was capable of capturing and analyzing the cells at a single cell and small cell-population level. We examined the change in exocytosis (i.e. neurotransmitterrelease) properties of a single PC12 cell, when exposed to CuOand TiO2 nanoparticles. We found both nanomaterials to interfere with the cell exocytosis function. We also studied the whole-cell response of a single-cell and a small cell-population simultaneously in real-time for the first time. The presented study can be a reference to the future research in the direction of nanotoxicity assessment to develop miniature, simple, and cost-effective tool for fast, quantitative measurements at high throughput level. The designed lab-on-a-chip device and measurement techniques utilized in the present work can be applied for the assessment of othernanoparticles' toxicity, as well.

Menopause, rurlity, and obesity in rural African American women

In the US, one in every eight deaths is due to an obesity-related chronic health condition (ORCHC). More than half of African American women (AAW) 20 years old or older are obese or morbidly obese, as are 63% of menopausal AAW. Many have ORCHC that increase their morbidity and mortality and increase health care costs. In 2013, 42.6 percent of AAs living in South Carolina (SC) were obese. The purpose of this cross-sectional study was to identify the cognitive, behavioral, biological, and demographic factors that influence health outcomes (BMI, and ORCHC) of AAW living in rural SC. A sample of 200 AAW (50 in each of the 4 groups of rurality by menopausal status), 18-64 years, completed the: Menopausal Rating Scale (symptoms); Body Image Assessment for Obesity (self-perception of body); Mental Health Inventory; Block Food Frequency Questionnaire; Eating Behaviors and Chronic Conditions, Traditional Food Habits, and Food Preparation Technique questionnaires — and measures for Body Mass Index. Most rural, and premenopausal AAW were single and not living with a partner. Premenopausal women had significantly higher educational levels. Sixty percent of AAW had between 1 and 5 ORCHC. Most AAW used salt based seasonings, ate deep fried foods 1 to 3 times a week, and ate outside the home 1 to 3 times a month. Few AAW knew the correct daily serving for grains and dairy, and most consumed less than the recommended daily serving of fruits, vegetables and dairy. Morbidly obese AAW used more traditional food preparation techniques than obese and normal-weight AAW. Rural, and menopausal AAW had significantly higher morbid obesity levels, consumed larger portions of meats and vegetables, and reported more body image dissatisfaction than very rural AAW, and premenopausal AAW, respectively. Controlling for socioeconomic factors the relationships between perceptions of body images, psychological distress, and psychological wellbeing remained significant for numbers of ORCHC^

Numerical groundwater flow modeling in the Wakal River basin, India

Increasing dependence on groundwater in the Wakal River basin, India, jeopardizes water supply sustainability. A numerical groundwater model was developed to better understand the aquifer system and to evaluate its potential in terms of quantity and replenishment. Potential artificial recharge areas were delineated using landscape and hydrogeologic parameters, Geographic Information System (GIS), and remote sensing. Groundwater models are powerful tools for recharge estimation when transmissivity is known. Proper recharge must be applied to reproduce field-measured heads. The model showed that groundwater levels could decline significantly if there are two drought years in every four years that result in reduced recharge, and groundwater withdrawal is increased by 15%. The effect of such drought is currently uncertain however, because runoff from the basin is unknown. Remote sensing and GIS revealed areas with slopes less than 5%, forest cover, and Normalized Difference Vegetative Index greater than 0.5 that are suitable recharge sites.