Exploring exploration : career identity development and temperment /

Career identity exploration is a central component of the lives of undergraduate university students. Although students are encouraged to explore, it is unclear whether different methods of exploration are better suited for certain individuals. In the present study, quantitative data were collected to examine the relationship between shyness and various methods of exploration. Two hundred fifty-seven university undergraduate students (29 male), ranging in age from 17-25 years completed a 60-minute self-report questionnaire. Shyness, identity, identity distress, subjective dimensions of exploration (satisfaction with exploration, reasons for not exploring, helpfulness of exploration methods), foci of exploration (non-social, social, self, and environmental), approaches to exploration (breadth, depth), and moderating variables (social support, sociability) were measured. Shyness was positively correlated with moratorium (high exploration, low commitment) and uncorrelated with the other identity statuses. Shyness was also positively correlated with identity distress, and a predicted interaction between shyness and identity diffusion predicting career identity distress was supported. Shyness was negatively correlated with satisfaction with amount of exploration engaged in to-date. In addition, shyness was correlated with the likelihood of selecting too stressful and too anxiety provoking as reasons for engaging in less exploration than one would like. Expected relationships between shyness and beliefs about, and engagement in, various methods of exploration were largely non-significant. Exceptions to this were the negative correlations between shyness and engagement in social exploration, and beliefs about the helpfulness of social self-exploration, both of which were significant at a trend level. A predicted interaction between shyness and social support predicting total social exploration was supported, showing that high social support buffers the negative relationship between shyness and exploration; such a moderating relationship did not exist, however, between sociability, shyness and social exploration. Results suggest that although shy university students are engaged in career exploration, they are experiencing feelings of distress and dissatisfaction with their career identity exploration and development. Thus, to help shy students become successfiil in their exploration, it is important for counsellors, family members, and peers to be aware of the feelings the individuals are experiencing and help them reduce the anxiety and stress associated with the exploration process. One promising method, supported by the results in this study, is by encouraging shy individuals to explore with social support.

Exploring the experiences of parents with children who have communication delays, as a population at risk for the development of behavioural concerns

Existing research identifies preschoolers with communication delays as a population at risk for the development of behavioural concerns. This risk increases when additional environmental factors such as parental stress and family conflict are also present. Research has also shown that behavioural concerns can be stable over time when they develop early. However, early intervention has been shown to be effective in addressing these concerns. The effectiveness of early intervention in addressing both child and family outcomes increases when interventions are delivered in a family-centred approach. This research project made use of data related to child behaviour and parenting, gathered through the Family Resource Project which explored the parenting experiences and resource access and allocation decisions of families who have preschool children with and without communication delays. Cluster analysis was used to explore whether there were identifiable clusters of children and families within each sample. Interview data fi"om each identified family cluster was then explored further, to identify how parents described their child's behaviour and their experience of parenting. Results show that, within this sample, parents of preschoolers with communication delays described their child's behaviour and their experience of parenting differently than did parents of children without communication delays. Results also showed that within this sample parents experiencing parental stress and/or family conflict described their child's behaviour and their experience of parenting differently than did parents from other clusters. Results suggest support for early intervention and the use of family-centred intervention, particularly for families of children with communication delays.

The development of automated methods for the determination of trace concentrations of carbomate pesticides in water using solid sorbent pre-concentration methods and high performance liquid chromatography /

Several automated reversed-phase HPLC methods have been developed to determine trace concentrations of carbamate pesticides (which are of concern in Ontario environmental samples) in water by utilizing two solid sorbent extraction techniques. One of the methods is known as on-line pre-concentration'. This technique involves passing 100 milliliters of sample water through a 3 cm pre-column, packed with 5 micron ODS sorbent, at flow rates varying from 5-10 mUmin. By the use of a valve apparatus, the HPLC system is then switched to a gradient mobile phase program consisting of acetonitrile and water. The analytes, Propoxur, Carbofuran, Carbaryl, Propham, Captan, Chloropropham, Barban, and Butylate, which are pre-concentrated on the pre-column, are eluted and separated on a 25 cm C-8 analytical column and determined by UV absorption at 220 nm. The total analytical time is 60 minutes, and the pre-column can be used repeatedly for the analysis of as many as thirty samples. The method is highly sensitive as 100 percent of the analytes present in the sample can be injected into the HPLC. No breakthrough of any of the analytes was observed and the minimum detectable concentrations range from 10 to 480 ng/L. The developed method is totally automated for the analysis of one sample. When the above mobile phase is modified with a buffer solution, Aminocarb, Benomyl, and its degradation product, MBC, can also be detected along with the above pesticides with baseline resolution for all of the analytes. The method can also be easily modified to determine Benomyl and MBC both as solute and as particulate matter. By using a commercially available solid phase extraction cartridge, in lieu of a pre-column, for the extraction and concentration of analytes, a completely automated method has been developed with the aid of the Waters Millilab Workstation. Sample water is loaded at 10 mL/min through a cartridge and the concentrated analytes are eluted from the sorbent with acetonitrile. The resulting eluate is blown-down under nitrogen, made up to volume with water, and injected into the HPLC. The total analytical time is 90 minutes. Fifty percent of the analytes present in the sample can be injected into the HPLC, and recoveries for the above eight pesticides ranged from 84 to 93 percent. The minimum detectable concentrations range from 20 to 960 ng/L. The developed method is totally automated for the analysis of up to thirty consecutive samples. The method has proven to be applicable to both purer water samples as well as untreated lake water samples.

The interpretation of environmental sustainability (ES) by the IOC/Olympic Games 1994-2008

The purpose of this qualitative multi-case study was to examine the interpretation of environmental sustainability (ES) within the Olympic 11 Movement. Two research questions guided the inquiry - first, how has the concept of ES been defined by the International Olympic Committee (lOC), and second, how has the concept of ES been defined and enacted by the Organizing Committees ofthe Olympic Games (OCOGs)? During the past two decades, the International Olympic Committee (lOC) established several policies and programs related to ES. Its actions reflect a broader trend of environmentalism within economic and social spheres around the world (Milton-Smith, 2002). Despite the numerous initiatives, the Olympic Games continue to cause significant environmental damage. Frey, et al. (2007) argued that the Olympic Movement contradicts the fundamental premises of ES because the Games are hosted in a two week time period, are situated in a confined area, and accumulate operating and infrastructure costs in the billions of dollars. Further, Etzion (2007) stated "there is positive and significant correlation between firm siz~ and environmental performance" (p. 642) and in the context of the Olympics the sizeimpact relation is striking. Since 1972, the year the UN launched its international environmental awareness efforts, the Summer Olympics grew to 201 nations (39% increase), 10,500 athletes (32% increase), 28 sports (30% increase), and 302 events (43% increase) (Johnson, 2004; Girginov & Parry, 2005; Upegui, 2008). The proliferation of Games activities counters the ES principles that exist within many of the IOC declarations, policies and programs.

EARLY LIFE EXPOSURE TO GENISTEIN AND DAIDZEIN DISRUPTS STRUCTURAL DEVELOPMENT OF REPRODUCTIVE ORGANS IN FEMALE MICE

In mice, exposure to isoflavones (ISO), abundant in soy infant formula, during the first 5 d of life alters structural and functional development of reproductive organs. Effects of longer exposures are unknown. The study objective was to evaluate whether exposure to a combination of daidzein and genistein in the first 10 compared to 5 d of life results in greater adverse effects on ovarian and uterine structure in adult mice. Thirteen litters of 8–12 pups were cross-fostered and randomized to corn oil or ISO (2 mg daidzein + 5 mg genistein/kg body weight/d) for the first 5 or 10 d of life. The 10-d protocol mimicked the period when infants are fed soy protein formula (SPF) but avoids the time when suckling pups can consume the mother’s diet. Body and organ weights and histology of ovaries and uteri were analyzed. There were no differences in the ovary or uterus weight, number of ovarian follicles, number of multiple oocyte follicles, or percent of ovarian cysts with 5 or 10 d of ISO intervention compared to respective controls. The 10-d ISO group had higher body weights from 6 d to 4 mo. of age and a higher percent of hyperplasia in the oviduct than the respective control. Lower numbers of ovarian corpus lutea and a higher incidence of abnormal changes were reported in the uteri of both ISO groups compared to their respective controls. Five- and 10-d exposure to ISO had similar long-lasting adverse effects on the structures of ovaries and uterus in adult mice. Only the 10-d ISO exposure resulted in greater body weight gain at adulthood.

The Influence of Cerebral Blood Flow and Carbon Dioxide on Neuromuscular Responses During Environmental Stress

Although reductions in cerebral blood flow (CBF) may be implicated in the development of central fatigue during environmental stress, the contribution from hypocapnia-induced reductions in CBF versus reductions in CBF per se has yet to be isolated. The current research program examined the influence of CBF, with and without consequent hypocapnia, on neuromuscular responses during hypoxia and passive heat stress. To this end, neuromuscular responses, as indicated by motor evoked potentials (MEP), maximal M-wave (Mmax) and cortical voluntary activation (cVA) of the flexor carpi radialis muscle during isometric wrist flexion, was assessed in three separate projects: 1) hypocapnia, independent of concomitant reductions in CBF; 2) altered CBF during severe hypoxia and; 3) thermal hyperpnea-mediated reductions in CBF, independent of hypocapnia. All projects employed a custom-built dynamic end-tidal forcing system to control end-tidal PCO2 (PETCO2), independent of the prevailing environmental conditions, and cyclooxygenase inhibition using indomethacin (Indomethacin, 1.2 mg·Kg-1) to selectively reduce CBF (estimated using transcranial Doppler ultrasound) without changes in PETCO2. A primary finding of the present research program is that the excitability of the corticospinal tract is inherently sensitive to changes in PaCO2, as demonstrated by a 12% increase in MEP amplitude in response to moderate hypocapnia. Conversely, CBF mediated reductions in cerebral O2 delivery appear to decrease corticospinal excitability, as indicated by a 51-64% and 4% decrease in MEP amplitude in response to hypoxia and passive heat stress, respectively. The collective evidence from this research program suggests that impaired voluntary activation is associated with reductions in CBF; however, it must be noted that changes in cVA were not linearly correlated with changes in CBF. Therefore, other factors independent of CBF, such as increased perception of effort, distress or discomfort, may have contributed to the reductions in cVA. Despite the functional association between reductions in CBF and hypocapnia, both variables have distinct and independent influence on the neuromuscular system. Therefore, future studies should control or acknowledge the separate mechanistic influence of these two factors.

Development and disease of the photoreceptor cilium

Primary cilia are microtubule-rich hair-like extensions protruding from the surface of most post-mitotic cells. They act as sensory organelles that help interpret various environmental cues. Mutations in genes encoding proteins involved in ciliogenesis or protein transport to the primary cilia lead to a wide variety of diseases commonly referred to as ciliopathies,which include primary ciliary dyskinesia, situs invertus, hydrocephalus, kidney diseases, respiratory diseases, and retinal degenerations. In the retina, the photoreceptor cells have a highly specialized primary cilium called the outer segment (OS), which is essential for photosensation. Development of the photoreceptor OS shares key regulatory mechanisms with ciliogenesis in other cell types. Accumulating evidence indicates that mutations that affect OS development and/or protein transport to the OS generally lead to photoreceptor degeneration, which can be accompanied by a range of other clinical manifestations due to the dysfunction of primary cilia in different cell types. Here, we review the general mechanisms regulating ciliogenesis, and present different examples of mutations affecting OS ciliogenesis and protein transport that lead to photoreceptor degeneration. Overall, we conclude that the genetic and molecular evidence accumulated in recent years suggest a clear link between the development and function of the primary cilium and various clinical conditions. Future studies aimed at uncovering the cellular and molecular mechanisms implicated in ciliogenesis in a wide variety of animal models should greatly increase our understanding of the pathophysiology of many human diseases, including retinal degenerations.

Design thinking and the precautionary principle : development of a theoretical model complementing preventive judgment for design for sustainability enriched through a study of architectural competitions adopting LEED

Cette thèse contribue à une théorie générale de la conception du projet. S’inscrivant dans une demande marquée par les enjeux du développement durable, l’objectif principal de cette recherche est la contribution d’un modèle théorique de la conception permettant de mieux situer l’utilisation des outils et des normes d’évaluation de la durabilité d’un projet. Les principes fondamentaux de ces instruments normatifs sont analysés selon quatre dimensions : ontologique, méthodologique, épistémologique et téléologique. Les indicateurs de certains effets contre-productifs reliés, en particulier, à la mise en compte de ces normes confirment la nécessité d’une théorie du jugement qualitatif. Notre hypothèse principale prend appui sur le cadre conceptuel offert par la notion de « principe de précaution » dont les premières formulations remontent du début des années 1970, et qui avaient précisément pour objectif de remédier aux défaillances des outils et méthodes d’évaluation scientifique traditionnelles. La thèse est divisée en cinq parties. Commençant par une revue historique des modèles classiques des théories de la conception (design thinking) elle se concentre sur l’évolution des modalités de prise en compte de la durabilité. Dans cette perspective, on constate que les théories de la « conception verte » (green design) datant du début des années 1960 ou encore, les théories de la « conception écologique » (ecological design) datant des années 1970 et 1980, ont finalement convergé avec les récentes théories de la «conception durable» (sustainable design) à partir du début des années 1990. Les différentes approches du « principe de précaution » sont ensuite examinées sous l’angle de la question de la durabilité du projet. Les standards d’évaluation des risques sont comparés aux approches utilisant le principe de précaution, révélant certaines limites lors de la conception d’un projet. Un premier modèle théorique de la conception intégrant les principales dimensions du principe de précaution est ainsi esquissé. Ce modèle propose une vision globale permettant de juger un projet intégrant des principes de développement durable et se présente comme une alternative aux approches traditionnelles d’évaluation des risques, à la fois déterministes et instrumentales. L’hypothèse du principe de précaution est dès lors proposée et examinée dans le contexte spécifique du projet architectural. Cette exploration débute par une présentation de la notion classique de «prudence» telle qu’elle fut historiquement utilisée pour guider le jugement architectural. Qu’en est-il par conséquent des défis présentés par le jugement des projets d’architecture dans la montée en puissance des méthodes d’évaluation standardisées (ex. Leadership Energy and Environmental Design; LEED) ? La thèse propose une réinterprétation de la théorie de la conception telle que proposée par Donald A. Schön comme une façon de prendre en compte les outils d’évaluation tels que LEED. Cet exercice révèle cependant un obstacle épistémologique qui devra être pris en compte dans une reformulation du modèle. En accord avec l’épistémologie constructiviste, un nouveau modèle théorique est alors confronté à l’étude et l’illustration de trois concours d'architecture canadienne contemporains ayant adopté la méthode d'évaluation de la durabilité normalisée par LEED. Une série préliminaire de «tensions» est identifiée dans le processus de la conception et du jugement des projets. Ces tensions sont ensuite catégorisées dans leurs homologues conceptuels, construits à l’intersection du principe de précaution et des théories de la conception. Ces tensions se divisent en quatre catégories : (1) conceptualisation - analogique/logique; (2) incertitude - épistémologique/méthodologique; (3) comparabilité - interprétation/analytique, et (4) proposition - universalité/ pertinence contextuelle. Ces tensions conceptuelles sont considérées comme autant de vecteurs entrant en corrélation avec le modèle théorique qu’elles contribuent à enrichir sans pour autant constituer des validations au sens positiviste du terme. Ces confrontations au réel permettent de mieux définir l’obstacle épistémologique identifié précédemment. Cette thèse met donc en évidence les impacts généralement sous-estimés, des normalisations environnementales sur le processus de conception et de jugement des projets. Elle prend pour exemple, de façon non restrictive, l’examen de concours d'architecture canadiens pour bâtiments publics. La conclusion souligne la nécessité d'une nouvelle forme de « prudence réflexive » ainsi qu’une utilisation plus critique des outils actuels d’évaluation de la durabilité. Elle appelle une instrumentalisation fondée sur l'intégration globale, plutôt que sur l'opposition des approches environnementales.

Sagittal sacro-pelvic morphology and spino-pelvic balance in pediatric lumbosacral spondylolisthesis : development of a postural model = Morphologie sacro-pelvienne et équilibre spino-pelvien sagittal dans le spondylolisthésis lombosacré pédiatrique : développement d'un modèle postural

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

The influence of environmental contaminants on time to pregnancy

Cette thèse porte sur l’évaluation de l’impact de certains composés environnementaux sur la fécondité féminine, tel que mesuré par le délai de conception (« time to pregnancy » en anglais, ou TTP). Cette recherche a été réalisée dans le cadre de l’Étude mère-enfant sur les composés chimiques de l’environnement (MIREC), une cohorte de grossesse de 2001 femmes recrutées durant le premier trimestre dans dix villes canadiennes de 2008 à 2011. Les données des questionnaires et les échantillons biologiques ont servi à évaluer l’effet de deux groupes de composés : les persistants [composés perfluorés – perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA) et perfluorohexane sulfonate (PFHxS)] et les non persistants (bisphénol A, triclosan et phtalates). Cette thèse comprend également une analyse du potentiel du ratio index-annulaire (2D:4D) comme mesure de sensibilité endocrinienne. À ce jour, des mesures anthropométriques ont été collectées sur environ 800 mères-enfants dans le cadre de l’Étude mère-enfant sur les composés chimiques de l’environnement : biomonitoring et neurodéveloppement à la petite enfance (MIREC CD Plus), un suivi de la cohorte MIREC portant sur la croissance et le développement des enfants jusqu’à 5 ans. Sur l’ensemble, les résultats de cette thèse permettent d’étoffer les preuves concernant les effets adverses potentiels de plusieurs contaminants environnementaux sur la fécondité féminine, telle que mesurée par le TTP. Dans le premier article, nous avons montré une association entre les PFOA et les PFHxS et une baisse de fécondité, ce que d’autres recherches avaient déjà révélé. Dans le deuxième article, nous avons évalué l’effet du triclosan sur le TTP, ce qui n’avait jamais été examiné, pour montrer un délai plus élevé chez les femmes du quartile supérieur d’exposition. De plus, nos résultats sont en accord avec ceux de la seule étude ayant évalué l’effet du Bisphénol A sur la fécondité féminine, qui n’avait pas détecté d’effet. Finalement, nos données semblent indiquer une association entre l’exposition des femmes aux phtalates et un TTP plus court, mais ces résultats ne sont pas statistiquement significatifs. En ce qui a trait au potentiel du ratio index-annuaire (2D:4D) pour mesurer la sensibilité endocrinienne chez les femmes, nos données ne permettent pas d’établir une association entre ce ratio et le TTP. Pour ce qui est des enfants, nous n’avons pas trouvé d’effet adverse entre le tabagisme de la mère durant la grossesse et leur ratio 2D:4D. Par conséquent, nos données ne semblent pas justifier l’utilisation du ratio 2D:4D pour mesurer la sensibilité endocrinienne en lien avec le potentiel reproducteur (basé sur le TTP) ou l’exposition des enfants au tabac durant le premier trimestre de grossesse.

Early adversity, brain development and emotion processing in monozygotic twins

Il existe actuellement de nombreuses preuves démontrant que des facteurs génétiques et environnementaux interagissent pendant des périodes spécifiques du développement pour rendre une personne vulnérable aux troubles psychologiques via diverses adaptations physiologiques. Cette thèse porte sur l'impact de l’adversité prénatale (représentée par le petit poids à la naissance, PPN) et de l’adversité postnatale précoce (symptômes dépressifs maternels et comportements maternels négatifs), sur le développement du cerveau, particulièrement les régions fronto-limbiques impliquées dans le traitement des émotions, pendant l'enfance et l'adolescence. Des jumeaux monozygotes (MZ) sont utilisés, lorsque possible, afin de contrôler pour les effets génétiques. Les chapitres 1 et 2 présentent les résultats de la vérification de l'hypothèse que l’adversité prénatale et postnatale précoce sont associées à une altération du fonctionnement des régions fronto-limbique tels que l’amygdale, l’hippocampe, l’insula, le cortex cingulaire antérieur et le cortex préfrontal, en réponse à des stimuli émotifs chez des enfants et des adolescents. On observe que les symptômes dépressifs maternels sont associés à une activation plus élevée des régions fronto-limbiques des enfants en réponse à la tristesse. Les résultats de l’étude avec des adolescents suggèrent que le PPN, les symptômes dépressifs et les comportements maternels négatifs sont associés à une fonction altérée des régions fronto-limbiques en réponse à des stimuli émotionnels. Chez les jumeaux MZ on observe également que la discordance intra-paire de PPN et de certains comportements maternels est associée à une discordance intra-paire du fonctionnement du cerveau et que ces altérations diffèrent selon le sexe. Le chapitre 3 présente les résultats de la vérification de l'hypothèse que l’adversité prénatale et postnatale précoce sont associées à un volume total réduit du cerveau et de l’hypothèse que les comportements maternels peuvent servir de médiateur ou de modérateur de l'association entre le PPN et le volume du cerveau. Avec des jumeaux MZ à l’adolescence on observe a) que le PPN est effectivement associé à une diminution du volume total du cerveau et b) que la discordance intra-paire de PPN est associée à une discordance du volume du cerveau. En somme, cette thèse présente un ensemble de résultats qui soutiennent deux hypothèses importantes pour comprendre les effets de l’environnement sur le développement du cerveau : que l’environnement prénatal et postnatal précoce ont un impact sur le développement du cerveau indépendamment du code génétique et que les mécanismes impliqués peuvent différer entre les garçons et les filles. Finalement, l’ensemble de ces résultats sont discutés à la lumière des autres travaux de recherche dans ce domaine et des avenues à explorer pour de la recherche ultérieure sont proposées.

Integrated Management for Sustainable Development of Coastal Zones – A Gis Based Study on the Central Kerala Coast

The present study focuses on the stability of the coast, exploitation of the coastal resources, human activities within the study are that extends from Fort Cochin at north to Thottappally at south, central Kerala State and hinterlands, socio-economic problems of the coastal community and the environmental issues arising in the recent past due to human activities. The objective of the study is critically analyse the coastal zone region and prevailing situation and to propose a comprehensive management plan for the sustainable development of the region under study. The thesis covers varied aspects of coastal uses like fisheries, tourism, land use, water resources etc. To critically examine the above scenarios, the ILWIS (Integrated Land and Water Information Systems) – GIS software has been used. A satellite image of the area has been used for the coastline change detection and land use patterns. The outcome of the present study will be beneficial to the various stakeholders within the coastal region and its hinterlands. To further add, this study should find better applications to similar or near-similar situations of Southeast Asia where identical scenarios are noticeable.

White Spot Syndrone Virus in Penaeids: Histopathology, Development of Polyclonal Antisera and a Cocktail Vaccine

The present study is the first comprehensive approach towards histopathology of White Spot Syndrome Virus (WSSV) in Penaeus indicus. WSSV could be demonstrated in the nuclei of all tissues, except those of midgut, subjected of electron microscopic observation. They were the nuclei of gill, foregut, heart, hepatopancreatic connective tissue, hindgut, nerve and dorsal aorta. A comparison was made between the electron microscopic and histopathological observations and a greater degree of correlation between the two in depicting the severity of the infection of the infection was unraveled. The study also illustrated variations in response and susceptibility of various tissues to WSSV infection. Accordingly, out of the tissues investigated, gill, foregut, hindgut and dorsal aorta exhibited advanced viral multiplication than the other tissues such as heart, midgut, nerve and hepatopancreas. Even though hepatocytes were not infected the connective tissue nuclei were packed with virions.

Development of Bioreactors for Nitrifying Water In Closed System Hatcheries Of Penaeid And Non-Penaeid Prawns

In the present study the development of bioreactors for nitrifying water in closed system hatcheries of penaeid and non-penaeid prawns. This work is an attempt in this direction to cater to the needs of aquaculture industry for treatment and remediation of ammonia and nitrate in penaeid and non-penaeid hatcheries, by developing nitrifying bacteria allochthonous to the particular environment under consideration, and immobilizing them on an appropriately designed support materials configured as reactors. Ammonia toxicity is the major limiting factors in penaeid and non-penaeid hatchery systems causing lethal and sublethal effects on larvae depending on the pH values. Pressing need of the aquaculture industry to have a user friendly and economically viable technology for the removal of ammonia, which can be easily integrated to the existing hatchery designs without any major changes or modifications. Only option available now is to have biological filters through which water can be circulated for the oxidation of ammonia to nitrate through nitrite by a group of chemolithotrophs known as nitrifying bacteria. Two types of bioreactors have been designed and developed. The first category named as in situ stringed bed suspended bioreactor(SBSBR) was designed for use in the larval rearing tanks to remove ammonia and nitrite during larval rearing on a continuous basis, and the other to be used for nitrifying freshly collected seawater and spent water named as ex situ packed bed bioreactior(PBBR). On employing the two reactors together , both penaeid and non-penaeid larval rearing systems can be made a closed recirculating system at least for a season. A survey of literature revealed that the in situ stringed bed suspended reactor developed here is unique in its design, fabrication and mode of application.