UTILIZING ELECTRONIC NOSE AND GC-MS TO EXAMINE CRITICAL FACTORS INFLUENCING THE FORMATION OF ODOROUS VOC’S IN BIOSOLIDS.

Despite the efforts to better manage biosolids field application programs, biosolids managers still lack of efficient and reliable tools to apply large quantities of material while avoiding odor complaints. Objectives of this research were to determine the capabilities of an electronic nose in supporting process monitoring of biosolids production and, to compare odor characteristics of biosolids produced through thermal-hydrolysis anaerobic digestion (TH-AD) to those of alkaline stabilization in the plant, under storage and in the field. A method to quantify key odorants was developed and full scale sampling and laboratory simulations were performed. The portable electronic nose (PEN3) was tested for its capabilities of distinguishing alkali dosages in the biosolids production process. Frequency of recognition of unknown samples was tested achieving highest accuracy of 81.1%. This work exposed the need for a different and more sensitive electronic nose to assure its applicability at full scale for this process. GC-MS results were consistent with those reported in literature and helped to elucidate the behavior of the pattern recognition of the PEN3. Odor characterization of TH-AD and alkaline stabilized biosolids was achieved using olfactometry measurements and GC-MS. Dilution-to-threshold of TH-AD biosolids increased under storage conditions but no correlation was found with the target compounds. The presence of furan and three methylated homologues in TH-AD biosolids was reported for the first time proposing that these compounds are produced during thermal hydrolysis process however, additional research is needed to fully describe the formation of these compounds and the increase in odors. Alkaline stabilized biosolids reported similar odor concentration but did not increase and the ‘fishy’ odor from trimethylamine emissions resulted in more offensive and unpleasant odors when compared to TH-AD. Alkaline stabilized biosolids showed a spike in sulfur and trimethylamine after 3 days of field application when the alkali addition was not sufficient to meet regulatory standards. Concentrations of target compounds from field application of TH-AD biosolids gradually decreased to below the odor threshold after 3 days. This work increased the scientific understanding on odor characteristics and behavior of two types of biosolids and on the application of electronic noses to the environmental engineering field.

"I’ll call you when we are ready" (One family’s experience of critical care and end of life decision making)

The purpose of this paper is to explore through narrative accounts one family's expérience of critical care, after the admission of a family member to an Intensive Care Unit (ICU) and their subséquent death five weeks later. Numerous studies support the need for effective communication and clear information to be given to the family. In this instance it was évident from their stories that there were numerous barriers to communication, including language and a lack of insight into the needs of the family. Many families do not understand the complexities of nursing care in an ICU so lack of communication by nursing staff was identified as uncaring behavior and encounters. Facilitating a family's proximity to a dying patient and encouraging them to participate in care helps to maintain some sensé of personal control. Despite a commitment to involving family members in care, which was enshrined in the Unit Philosophy, relatives were banished to the waiting room for hours. They experienced feelings of powerlessness and helplessness as they waited with other relatives for news following investigations or until 'the doctor had completed his rounds'. Explanations of "we must make 'the patient' comfortable" was no consolation for those who wished to be involved in care. The words "I'il call you when we are ready" became a mantra to the forgotten families who waited patiently for those with power to admit them to the ICU. Implications are this family felt they were left alone to cope with the traumatic expériences leading up to and surrounding the death. They felt mainly supported by the priest, who not only administered the last rites but provided spiritual support to the family and dealt sensitively with many issues. Paternalism in décision making when there is a moral obligation to ensure that discussions on end of life dilemmas are an inclusive process with families, doctors, nurses was not understood, therefore it caused conflict within the family over EOL décision making. The family felt that the opportunity to share expériences through telling and retelling their stories would enable them to reconfigure the past and create purpose in the future.

ROLE OF THE FRONTAL EYE FIELD, SUPERIOR COLLICULUS, AND BASAL GANGLIA IN FLEXIBLE SACCADE BEHAVIOR

A distributed network of cortical and subcortical brain regions mediates the control of voluntary behavior, but it is unclear how this complex system may flexibly shift between different behavioral events. This thesis describes the neurophysiological changes in several key nuclei across the brain during flexible behavior, using saccadic eye movements in rhesus macaque monkeys. We examined five nuclei critical for saccade initiation and modulation: the frontal eye field (FEF) in the cerebral cortex, the subthalamic nucleus (STN), caudate nucleus (CD), and substantia nigra pars reticulata (SNr) in the basal ganglia (BG), and the superior colliculus (SC) in the midbrain. The first study tested whether a ‘threshold’ theory of how neuronal activity cues saccade initiation is consistent with the flexible control of behavior. The theory suggests there is a fixed level of FEF and SC neuronal activation at which saccades are initiated. Our results provide strong evidence against a fixed saccade threshold in either structure during flexible behavior, and indicate that threshold variability might depend on the level of inhibitory signals applied to the FEF or SC. The next two studies investigated the BG network as a likely candidate to modulate a saccade initiation mechanism, based on strong inhibitory output signals from the BG to the FEF and SC. We investigated the STN and CD (BG input), and the SNr (BG oculomotor output) to examine changes across the BG network. This revealed robust task-contingent shifts in BG signaling (Chapter 3), which uniquely impacted saccade initiation according to behavioral condition (Chapters 3 and 4). The thesis concludes with a published short review of the mechanistic effects of BG deep brain stimulation (Chapter 5), and a general discussion including proof of concept saccade behavioral changes in an MPTP-induced Parkinsonian model (Chapter 6). The studies presented here demonstrate that the conditions for saccade initiation by the FEF and SC vary according to behavioral condition, while simultaneously, large-scale task dependent shifts occur in BG signaling consistent with the observed modulation of FEF and SC activity. Taken together, these describe a mechanistic framework by which the cortico-BG loop may contribute to the flexible control of behavior.

The Behavior of Hydroxyl Units of Synthetic Goethite and its Dehydroxylated Product Hematite

The behavior of the hydroxyl units of synthetic goethite and its dehydroxylated product hematite was characterized using a combination of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) during the thermal transformation over a temperature range of 180-270 degrees C. Hematite was detected at temperatures above 200 degrees C by XRD while goethite was not observed above 230 degrees C. Five intense OH vibrations at 3212-3194, 1687-1674, 1643-1640, 888-884 and 800-798 cm(-1), and a H2O vibration at 3450-3445 cm(-1) were observed for goethite. The intensity of hydroxyl stretching and bending vibrations decreased with the extent of dehydroxylation of goethite. Infrared absorption bands clearly show the phase transformation between goethite and hematite: in particular. the migration of excess hydroxyl units from goethite to hematite. Two bands at 536-533 and 454-452 cm(-1) are the low wavenumber vibrations of Fe-O in the hematite structure. Band component analysis data of FTIR spectra support the fact that the hydroxyl units mainly affect the a plane in goethite and the equivalent c plane in hematite.

The effect of gender context on children's social behaviour in a limited resources situation : an observational study

Knowing when to compete and when to cooperate to maximize opportunities for equal access to activities and materials in groups is critical to children's social and cognitive development. The present study examined the individual (gender, social competence) and contextual factors (gender context) that may determine why some children are more successful than others. One hundred and fifty-six children (M age=6.5 years) were divided into 39 groups of four and videotaped while engaged in a task that required them to cooperate in order to view cartoons. Children within all groups were unfamiliar to one another. Groups varied in gender composition (all girls, all boys, or mixed-sex) and social competence (high vs. low). Group composition by gender interaction effects were found. Girls were most successful at gaining viewing time in same-sex groups, and least successful in mixed-sex groups. Conversely, boys were least successful in same-sex groups and most successful in mixed-sex groups. Similar results were also found at the group level of analysis; however, the way in which the resources were distributed differed as a function of group type. Same-sex girl groups were inequitable but efficient whereas same-sex boy groups were more equitable than mixed groups but inefficient compared to same-sex girl groups. Social competence did not influence children's behavior. The findings from the present study highlight the effect of gender context on cooperation and competition and the relevance of adopting an unfamiliar peer paradigm when investigating children's social behavior.

Autoethnography : critical appreciation of an emerging art

In this article, the author discusses how she applied autoethnography in a study of the design of hypermedia educational resources and shows how she addressed problematic issues related to autoethnographic legitimacy and representation. The study covered a 6-year period during which the practitioner’s perspective on the internal and external factors influencing the creation of three hypermedia CD-ROMs contributed to an emerging theory of design. The author highlights the interrelationship between perception and reality as vital to qualitative approaches and encourages researchers to investigate their reality more fully by practicing the art of autoethnography.

Enhancing the trust of location acquisition systems for critical applications and location-based security services

This paper identifies a number of critical infrastructure applications that are reliant on location services from cooperative location technologies such as GPS and GSM. We show that these location technologies can be represented in a general location model, such that the model components can be used for vulnerability analysis. We perform a vulnerability analysis on these components of GSM and GPS location systems as well as a number of augmentations to these systems.