The development of optimized high performance liquid chromatography systems for the analysis of improvised explosives

Existing instrumental techniques must be adaptable to the analysis of novel explosives if science is to keep up with the practices of terrorists and criminals. The focus of this work has been the development of analytical techniques for the analysis of two types of novel explosives: ascorbic acid-based propellants, and improvised mixtures of concentrated hydrogen peroxide/fuel. In recent years, the use of these explosives in improvised explosive devices (IEDs) has increased. It is therefore important to develop methods which permit the identification of the nature of the original explosive from post-blast residues. Ascorbic acid-based propellants are low explosives which employ an ascorbic acid fuel source with a nitrate/perchlorate oxidizer. A method which utilized ion chromatography with indirect photometric detection was optimized for the analysis of intact propellants. Post-burn and post-blast residues if these propellants were analyzed. It was determined that the ascorbic acid fuel and nitrate oxidizer could be detected in intact propellants, as well as in the post-burn and post-blast residues. Degradation products of the nitrate and perchlorate oxidizers were also detected. With a quadrupole time-of-flight mass spectrometer (QToFMS), exact mass measurements are possible. When an HPLC instrument is coupled to a QToFMS, the combination of retention time with accurate mass measurements, mass spectral fragmentation information, and isotopic abundance patterns allows for the unequivocal identification of a target analyte. An optimized HPLC-ESI-QToFMS method was applied to the analysis of ascorbic acid-based propellants. Exact mass measurements were collected for the fuel and oxidizer anions, and their degradation products. Ascorbic acid was detected in the intact samples and half of the propellants subjected to open burning; the intact fuel molecule was not detected in any of the post-blast residue. Two methods were optimized for the analysis of trace levels of hydrogen peroxide: HPLC with fluorescence detection (HPLC-FD), and HPLC with electrochemical detection (HPLC-ED). Both techniques were extremely selective for hydrogen peroxide. Both methods were applied to the analysis of post-blast debris from improvised mixtures of concentrated hydrogen peroxide/fuel; hydrogen peroxide was detected on variety of substrates. Hydrogen peroxide was detected in the post-blast residues of the improvised explosives TATP and HMTD.

The Development of High Performance Liquid Chromatography Systems for the Analysis of Improvised Explosives

Existing instrumental techniques must be adaptable to the analysis of novel explosives if science is to keep up with the practices of terrorists and criminals. The focus of this work has been the development of analytical techniques for the analysis of two types of novel explosives: ascorbic acid-based propellants, and improvised mixtures of concentrated hydrogen peroxide/fuel. In recent years, the use of these explosives in improvised explosive devices (IEDs) has increased. It is therefore important to develop methods which permit the identification of the nature of the original explosive from post-blast residues. Ascorbic acid-based propellants are low explosives which employ an ascorbic acid fuel source with a nitrate/perchlorate oxidizer. A method which utilized ion chromatography with indirect photometric detection was optimized for the analysis of intact propellants. Post-burn and post-blast residues if these propellants were analyzed. It was determined that the ascorbic acid fuel and nitrate oxidizer could be detected in intact propellants, as well as in the post-burn and post-blast residues. Degradation products of the nitrate and perchlorate oxidizers were also detected. With a quadrupole time-of-flight mass spectrometer (QToFMS), exact mass measurements are possible. When an HPLC instrument is coupled to a QToFMS, the combination of retention time with accurate mass measurements, mass spectral fragmentation information, and isotopic abundance patterns allows for the unequivocal identification of a target analyte. An optimized HPLC-ESI-QToFMS method was applied to the analysis of ascorbic acid-based propellants. Exact mass measurements were collected for the fuel and oxidizer anions, and their degradation products. Ascorbic acid was detected in the intact samples and half of the propellants subjected to open burning; the intact fuel molecule was not detected in any of the post-blast residue. Two methods were optimized for the analysis of trace levels of hydrogen peroxide: HPLC with fluorescence detection (HPLC-FD), and HPLC with electrochemical detection (HPLC-ED). Both techniques were extremely selective for hydrogen peroxide. Both methods were applied to the analysis of post-blast debris from improvised mixtures of concentrated hydrogen peroxide/fuel; hydrogen peroxide was detected on variety of substrates. Hydrogen peroxide was detected in the post-blast residues of the improvised explosives TATP and HMTD.

Predictors of first semester attrition and their relation to retention of generic associate degree nursing students

In community college nursing programs the high rate of attrition was a major concern to faculty and administrators. Since first semester attrition could lead to permanent loss of students and low retention in nursing programs, it was important to identify at-risk students early and develop proactive approaches to assist them to be successful. The goal of nursing programs was to graduate students who were eligible to take the national council licensing examination (RN). This was especially important during a time of critical shortage in the nursing workforce. ^ This study took place at a large, multi-campus community college, and used Tinto's (1975) Student Integration Model of persistence as the framework. A correlational study was conducted to determine whether the independent variables, past academic achievement, English proficiency, achievement tendency, weekly hours of employment and financial resources, could discriminate between the two grade groups, pass and not pass. Establishing the relationship between the selected variables and successful course completion might be used to reduce attrition and improve retention. Three research instruments were used to collect data. A Demographic Information form developed by the researcher was used to obtain academic data, the research questionnaire Measure of Achieving Tendency measured achievement motivation, and the Test of Adult Basic Education (TABE), Form 8, Level A, Tests 1, 4, and 5 measured the level of English proficiency. The Department of Nursing academic policy, requiring a minimum course grade of “C” or better was used to determine the final course outcome. A stepwise discriminant analysis procedure indicated that college language level and pre-semester grade point average were significant predictors of final course outcome. ^ Based on the findings of the study recommendations focused on assessing students' English proficiency prior to admission into the nursing program, an intensive remediation plan in language comprehension for at-risk students, and the selection of alternate textbooks and readings that more closely matched the English proficiency level of the students. A pilot study should be conducted to investigate the benefit of raising the admission grade point average. ^

An evaluation of an intervention strategy for retention and determination of predictors of success for high -risk students in an associate degree nursing program

The purpose of this study was twofold: (1) to evaluate the effect of a specific instructional Intervention, a Nursing Theory Laboratory, on increasing the retention of high risk students in the associate degree nursing program at Miami-Dade Community College in Miami, Florida; and (2) to identify predictors of success of high risk nursing students in this associate degree nursing program.^ Data were collected from the 195 nursing students enrolled in Nursing Fundamentals during the 1985-1987 academic years, and identified as high risk students. Control and experimental groups were selected based on enrollment in the Nursing Theory Laboratory.^ Results were determined by analyzing several cross-tabulations of selected variables and yielding chi square values, t-tests, and two discriminant analyses. There was no significant relationship between age or ethnic background and enrollment in the Nursing Theory Laboratory. There was no significant relationship between enrollment in the Nursing Theory Laboratory and success in Nursing 1 (Nursing Fundamentals). There was a significant relationship between enrollment in the Nursing Theory Laboratory and success in Nursing 3 (Medical-Surgical Nursing). Writing assessment test scores in two entrance tests and high risk categories, based on the number of enrollments in required science courses, were identified as predictors of success in this program.^ The conclusion was that the Nursing Theory Laboratory does not significantly improve retention of high risk associate degree nursing students if they are enrolled in this intervention at the same time they are enrolled in Nursing Fundamentals. Since those students who were enrolled in the Nursing Theory Laboratory had a significantly higher success rate in Nursing 3, than those students who were not enrolled in the Nursing Theory Laboratory, a recommendation of this study was to offer the Nursing Theory Laboratory to high risk students prior to the beginning of nursing courses. Another recommendation was that students deficient in reading and writing skills should be required to enroll in developmental courses prior to enrollment in the nursing course. ^

Predictors of client retention in alternative -to -prison substance abuse programs

Increased treatment retention among substance abusing individuals has been associated with reduced drug use, fewer arrests, and decreased unemployment, as well as a reduction in health risk behaviors. This longitudinal study examined the predictors of client retention for alternative to prison substance abuse treatment programs through assessing the roles of motivational factors and the client-worker relationship. The sample was comprised of 141 male felony offenders who were legally mandated to community based long-term residential drug treatment programs. ^ The primary measures used in the study were the consecutive days a participant remained in treatment, Stages of Change Readiness Model and Treatment Eagerness Scale (SOCRATES), the Working Alliance Inventory (WAI), and The Readiness Ruler. Hierarchical multiple regression analysis was conducted for four hypotheses (a) participants who are more motivated to change at the time of entry will remain in treatment longer, (b) participants who have a strong therapeutic alliance will remain in treatment a greater number of consecutive days than participants who have weaker therapeutic alliance, (c) motivation to change, as measured at treatment entry, will be positively related to therapeutic alliance, (d) during the course of treatment variation in motivation to change will be predicted by the therapeutic alliance. ^ Results support the following conclusions: Among clients in alternative-to prison programs the number of days in treatment is positively related to their motivation to change. The therapeutic alliance is not a predictor of the number of days in treatment. Motivation to change, particularly recognition of a drug problem, is positively related to the therapeutic alliance. Changes in motivation to change in response to treatment are positively related to the therapeutic alliance among clients in an alternative to prison substance abuse treatment programs. These results carry forward prior research and have implications for social work practice, research, and social welfare policy. ^

Retention and special education referral practices before and after the implementation of high -stakes testing

The rewards and sanctions associated with high-stakes testing may induce educators to participate in practices that will ensure the elimination of the scores of low-achieving students from the testing pool. Two ways in which scores may be eliminated is through retention or referral to special education. ^ This study examined the use of these practices at 179 elementary schools in Miami-Dade County Public Schools, the 4th largest school district in the country. Between- and within-subjects designs were analyzed using repeated measures analysis of variance to compare retention and referral to special education practices over a five-year period of time, two years prior to and two years after the implementation of Florida's high-stakes test, the Florida Comprehensive Assessment Test, FCAT. ^ Significant main effects for referral and retention over time were demonstrated. The use of retention steadily increased over the first three years, with its usage maintained during the fourth year. While the use of referral actually decreased from the first to second years, a significant change occurred after the implementation of the FCAT. ^ Examination of the use of these practices according to student and school characteristics revealed significant differences. Increases in the use of referral across time was significant for Black, non-Hispanic and Hispanic students, all limited English proficiency population categories, medium and low socioeconomic status category schools, all grade levels, and for schools with accountability grades of A. C, D and F with the most striking absolute increase occurring for F schools. Increases in the use of retention across time were significant for all ethnic groups, limited English proficiency categories, and socioeconomic status categories, for grades kindergarten through four and by gender. Significant increases occurred for schools with accountability performance grades of C, D and F; however the most dramatic increase occurred for the F schools. A direct relationship between performance category grade of school and their use of retention was demonstrated. The results suggest that schools changed their use of referral and retention in response to the implementation of the FCAT. ^

Factors Affecting De Novo Urinary Retention after Holmium Laser Enucleation of the Prostate

Objective Patients can experience urinary retention (UR) after Holmium laser enucleation of the prostate (HoLEP) that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP. Materials and Methods 336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37) and the non-urinary retention (non-UR; n = 299) groups. Results The mean age of patients was 68.3 (±6.5) years and the mean operative time was 75.3 (±37.4) min. Thirty seven patients (11.0%) experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7) days after UR. With regard to the causes of UR, 24 (7.1%) and 13 (3.9%) patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p<0.05), we found significant differences between the UR and the non-UR groups with regard to a morcellation efficiency (OR 0.701, 95% CI 0.498–0.988) and a bleeding-related complication, such as, a reoperation for bleeding (OR 0.039, 95% CI 0.004–0.383) or a transfusion (OR 0.144, 95% CI 0.027–0.877). Age, history of diabetes, prostate volume, pre-operative post-void residual, bladder contractility index, learning curve, and operative time were not significantly associated with the UR (p>0.05). Conclusions De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP.

It takes an institution's village to retain a student: A comprehensive look at two early warning system undergraduate retention programs and administrators' perceptions of students' experiences and the retention services they provide students in the early warning system retention programs

Institutions have implemented many campus interventions to address student persistence/retention, one of which is Early Warning Systems (EWS). However, few research studies show evidence of interventions that incorporate noncognitive factors/skills, and psychotherapy/psycho-educational processes in the EWS. A qualitative study (phenomenological interview and document analysis) of EWS at both a public and private 4-year Florida university was conducted to explore EWS through the eyes of the administrators of the ways administrators make sense of students' experiences and the services they provide and do not provide to assist students. Administrators' understanding of noncognitive factors and the executive skills subset and their contribution to retention and the executive skills development of at-risk students were also explored. Hossler and Bean's multiple retention lenses theory/paradigms and Perez's retention strategies were used to guide the study. Six administrators from each institution who oversee and/or assist with EWS for first time in college undergraduate students considered academically at-risk for attrition were interviewed. Among numerous findings, at Institution X: EWS was infrequently identified as a service, EWS training was not conducted, numerous cognitive and noncognitive issues/deficits were identified for students, and services/critical departments such as EWS did not work together to share students' information to benefit students. Assessment measures were used to identify students' issues/deficits; however, they were not used to assess, track, and monitor students' issues/deficits. Additionally, the institution's EWS did address students' executive skills function beyond time management and organizational skills, but did not address students' psychotherapy/psycho-educational processes. Among numerous findings, at Institution Y: EWS was frequently identified as a service, EWS training was not conducted, numerous cognitive and noncognitive issues/deficits were identified for students, and services/critical departments such as EWS worked together to share students' information to benefit students. Assessment measures were used to identify, track, and monitor students' issues/deficits; however, they were not used to assess students' issues/deficits. Additionally, the institution's EWS addressed students' executive skills function beyond time management and organizational skills, and psychotherapy/psycho-educational processes. Based on the findings, Perez's retention strategies were not utilized in EWS at Institution X, yet were collectively utilized in EWS at Institution Y, to achieve Hossler and Bean's retention paradigms. Future research could be designed to test the link between engaging in the specific promising activities identified in this research (one-to-one coaching, participation in student success workshops, academic contracts, and tutoring) and student success (e.g., higher GPA, retention). Further, because this research uncovered some concern with how to best handle students with physical and psychological disabilities, future research could link these same promising strategies for improving student performance for example among ADHD students or those with clinical depression.

Doctoral Students: Online, On Time, and On to Graduation

Increased numbers of students are enrolling in online doctoral programs. Although students enroll for a variety of reasons, many do not persist to the dissertation phase. The results of this quantitative study can guide the development of retention strategies for students who are at risk of academic failure in doctoral programs.

Predictors of client retention in alternative to prison substance abuse programs

Increased treatment retention among substance abusing individuals has been associated with reduced drug use, fewer arrests, and decreased unemployment, as well as a reduction in health risk behaviors. This longitudinal study examined the predictors of client retention for alternative to prison substance abuse treatment programs through assessing the roles of motivational factors and the client-worker relationship. The sample was comprised of 141 male felony offenders who were legally mandated to community based long-term residential drug treatment programs. The primary measures used in the study were the consecutive days a participant remained in treatment, Stages of Change Readiness Model and Treatment Eagerness Scale (SOCRATES), the Working Alliance Inventory (WAI), and The Readiness Ruler. Hierarchical multiple regression analysis was conducted for four hypotheses (a) participants who are more motivated to change at the time of entry will remain in treatment longer, (b) participants who have a strong therapeutic alliance will remain in treatment a greater number of consecutive days than participants who have weaker therapeutic alliance, (c) motivation to change, as measured at treatment entry, will be positively related to therapeutic alliance, (d) during the course of treatment variation in motivation to change will be predicted by the therapeutic alliance. Results support the following conclusions: Among clients in alternative-to prison programs the number of days in treatment is positively related to their motivation to change. The therapeutic alliance is not a predictor of the number of days in treatment. Motivation to change, particularly recognition of a drug problem, is positively related to the therapeutic alliance. Changes in motivation to change in response to treatment are positively related to the therapeutic alliance among clients in an alternative to prison substance abuse treatment programs. These results carry forward prior research and have implications for social work practice, research, and social welfare policy.

Retention and special education referral practices before and after the implementation of high-stakes testing

The rewards and sanctions associated with high-stakes testing may induce educators to participate in practices that will ensure the elimination of the scores of low-achieving students from the testing pool. Two ways in which scores may be eliminated is through retention or referral to special education. This study examined the use of these practices at 179 elementary schools in Miami-Dade County Public Schools, the 4th largest school district in the country. Between- and within-subjects designs were analyzed using repeated measures analysis of variance to compare retention and referral to special education practices over a five-year period of time, two years prior to and two years after the implementation of Florida's high-stakes test, the Florida Comprehensive Assessment Test, FCAT. Significant main effects for referral and retention over time were demonstrated. The use of retention steadily increased over the first three years, with its usage maintained during the fourth year. While the use of referral actually decreased from the first to second years, a significant change occurred after the implementation of the FCAT. Examination of the use of these practices according to student and school characteristics revealed significant differences. Increases in the use of referral across time was significant for Black, non-Hispanic and Hispanic students, all limited English proficiency population categories, medium and low socioeconomic status category schools, all grade levels, and for schools with accountability grades of A, C, D and F with the most striking absolute increase occurring for F schools. Increases in the use of retention across time were significant for all ethnic groups, limited English proficiency categories, and socioeconomic status categories, for grades kindergarten through four and by gender. Significant increases occurred for schools with accountability performance grades of C, D and F; however the most dramatic increase occurred for the F schools. A direct relationship between performance category grade of school and their use of retention was demonstrated. The results suggest that schools changed their use of referral and retention in response to the implementation of the FCAT.