Amphetamine increases blood pressure and heart rate but has no effect on motor recovery or cerebral haemodynamics in ischaemic stroke: a randomized controlled trial (ISRCTN 36285333)

Amphetamine enhances recovery after experimental ischaemia and has shown promise in small clinical trials when combined with motor or sensory stimulation. Amphetamine, a sympathomimetic, might have haemodynamic effects in stroke patients, although limited data have been published. Subjects were recruited 3-30 days post ischaemic stroke into a phase II randomised (1:1), double blind, placebo-controlled trial. Subjects received dexamphetamine (5mg initially, then 10mg for 10 subsequent doses with 3 or 4 day separations) or placebo in addition to inpatient physiotherapy. Recovery was assessed by motor scales (Fugl-Meyer, FM), and functional scales (Barthel index, BI and modified Rankin score, mRS). Peripheral blood pressure (BP), central haemodynamics and middle cerebral artery blood flow velocity were assessed before, and 90 minutes after, the first 2 doses. 33 subjects were recruited, age 33-88 (mean 71) years, males 52%, 4-30 (median 15) days post stroke to inclusion. 16 patients were randomised to placebo and 17 amphetamine. Amphetamine did not improve motor function at 90 days; mean (standard deviation) FM 37.6 (27.6) vs. control 35.2 (27.8) (p=0.81). Functional outcome (BI, mRS) did not differ between treatment groups. Peripheral and central systolic BP, and heart rate, were 11.2 mmHg (p=0.03), 9.5 mmHg (p=0.04) and 7 beats/minute (p=0.02) higher respectively with amphetamine, compared with control. A non-significant reduction in myocardial perfusion (Buckberg Index) was seen with amphetamine. Other cardiac and cerebral haemodynamics were unaffected. Amphetamine did not improve motor impairment or function after ischaemic stroke but did significantly increase BP and heart rate without altering cerebral haemodynamics.

Investigating a Hybrid Metaheuristic For Job Shop Rescheduling

Previous research has shown that artificial immune systems can be used to produce robust schedules in a manufacturing environment. The main goal is to develop building blocks (antibodies) of partial schedules that can be used to construct backup solutions (antigens) when disturbances occur during production. The building blocks are created based upon underpinning ideas from artificial immune systems and evolved using a genetic algorithm (Phase I). Each partial schedule (antibody) is assigned a fitness value and the best partial schedules are selected to be converted into complete schedules (antigens). We further investigate whether simulated annealing and the great deluge algorithm can improve the results when hybridised with our artificial immune system (Phase II). We use ten fixed solutions as our target and measure how well we cover these specific scenarios.

Avaliação transcricional de Glutationas -transferases em PEIXE-ZEBRA (Danio rerio) e alterações causadas pela exposição á Microcistina-LR

As Microcistinas são heptapeptídios cíclicos produzidos como metabólitos secundários por diferentes espécies de cianobactérias, sendo relevantes pelo seu potencial hepatotóxico. Peixes apresentam estratégias bioquímicas para detoxificar contaminantes ambientais, incluindo a ativação de enzimas de fase II de biotransformação, que incluem as isoformas de glutationa S-transferase (GST). As GST catalizam a conjugação de glutationa reduzida (GSH) com uma variedade de xenobióticos, incluindo as microcistinas. O presente estudo avaliou os níveis transcricionais de quinze isoformas de GST a fim de identificar isoformas possivelmente envolvidas na detoxificação de contaminantes ambientais como a microcistina-LR (MC-LR) em Danio rerio. A técnica de PCR em tempo real (RT-qPCR) foi utilizada para avaliação dos níveis transcricionais, permitindo análise das GST em diferentes órgãos, abundância e a ativação/repressão das isoformas de GST pela exposição à MC-LR. Foram avaliados os possíveis efeitos causados em brânquia e fígado após exposição por 24 hs às concentrações de 5 µg.L-1 e 50 µg.L-1 de MC-LR. Baseado nos scores de estabilidade para oito genes normalizadores, foram selecionados glicose-6-fosfato desidrogenase (g6pdh), β-actina1 e beta-2-microglobulina (b2m); b2m, alfa-tubulina 1 (tuba) e β- actin1; e tuba, b2m e g6pdh, para normalização dos níveis trancricionais de GST para distribuição órgão-específica, abundância e efeito da MC-LR em brânquia e fígado, respectivamente. A avaliação transcricional da distribuição órgão-específica revelou níveis significativos de gstal e gstk1.1 no fígado; gstp1 e gstp2 em brânquia; mgst3a, gstr1, gstm2, gstm33, gstp1, gstp2 e gstk1.1 no intestino; gstm2, gstm3 e gstal no olho e gstt1a e gsta2.1 no cérebro. Considerando os níveis de transcritos para um dado órgão, gstk1.1, gstal, gstp1 e gstt2 foram mais abundantes nos órgãos de detoxificação, tais como o fígado, brânquias e intestino, enquanto gstt1a e gsta2.1 foram mais abundantes no rim. Em brânquia, gsta2.1 e gstt1b foram reprimidas por 5 µg.L-1 de MC-LR e mgst1.1 foi reprimida em 50 µg.L-1 de MC-LR. No fígado, as isoformas gst2.2 e gstp2 foram reprimidas em ambas as concentrações, gstal foi reprimida em 5 µg.L-1, e gstt1a e gstk1.1 foram reprimidas em 50 µg.L-1 de MC-LR. As isoformas gstal, gstr1, gstp1, mgst3a, gstm1, gstm2 e gstm3 não foram alteradas pela exposição a MC-LR. Os resultados obtidos fornecem informações para a escolha de isoformas específicas de GST possivelmente envolvidas na detoxificação/toxicidade de MC-LR, a serem melhores caracterizadas ao nível protéico e também contribui para a escolha de genes normalizadores a serem utilizados em outros estudos da mesma natureza

Tenecteplase and alteplase in acute ischaemic stroke thrombolysis: clinical and imaging study

Introduction: Intravenous thrombolysis in acute ischaemic stroke with alteplase improves clinical outcomes, but it has limited efficacy and is associated with increased risk of intracranial haemorrhage. An improved tissue plasminogen activator, tenecteplase, was evidenced to be at least equally effective with lower risk of haemorrhage in acute myocardial infarction thrombolysis. To date, two completed phase II randomised controlled studies comparing tenecteplase and alteplase in acute ischaemic strokes showed variable results. Methods: A literature review of thrombolytic agents used in myocardial infarction and acute ischaemic stroke was performed, followed by a retrospective investigation of the bolus-to- infusion delay of alteplase administration. The main focus of this thesis is the report of our single centre phase II randomised controlled trial that compared tenecteplase (0.25mg/kg, maximum 25mg) and alteplase (0.9mg/kg, maximum 90mg, 10% as the initial bolus, following by one hour infusion with the rest of the dose) in acute ischaemic stroke thrombolysis using advanced imaging as biomarkers. Imaging comprised baseline computed tomography (CT), CT perfusion (CTP) and CT angiography (CTA), and CT+CTA at 24-48 hours. The primary end-point was penumbral salvage (CTP-defined penumbra volume minus follow-up CT infarct volume). A sub-study of coagulation and fibrinolysis analysis of the two agents was performed by comparing a group of coagulation variables measured pre-treatment, 3-12 hours, and 24±3 hours post thrombolysis. An individual patient data (IPD) meta-analysis was carried out using all three completed tenecteplase/alteplase comparison studies in stroke thrombolysis. We compared clinical outcomes including modified Rankin scale at 3 months, early neurological improvement at 24 hours, intracerebral haemorrhage rate and mortality at 3 months between all three tenecteplase doses (0.1mg/kg, 0.25 mg/kg, and 0.4mg/kg) examined and standard alteplase. Imaging outcomes including penumbra salvage, recanalisation rates were also compared using the data from the two studies that had advance imaging carried out. Results: Delay between the initial bolus and the subsequent infusion in administration of alteplase is common. This may reduce the likelihood of achieving a good functional outcome. Among the 104 patients recruited in ATTEST trial, 71 contributed to the imaging primary outcome. No significant differences were observed for penumbral salvage [68 (SD 28) % tenecteplase vs 68 (SD 23) % alteplase], mean difference 1% (95% confidence interval -10%, 12%, p=0·81) or for any secondary end-point. The SICH incidence (1/52, 2% vs 2/51, 4%, by SITS-MOST definition, p=0·55; by ECASS-2 definition, 3/52, 6% tenecteplase vs 4/51, 8% alteplase, p=0.59) did not differed significantly. There was a trend towards lower ICH risk in the tenecteplase group (8/52 tenecteplase, 15% vs 14/51 alteplase, 29%, p=0·091). Compared to baseline, alteplase caused significant hypofibrinogenaemia (p=0.002), prolonged Prothrombin Time (PT) (p=0.011), hypoplasminogenaemia (p=0.001) and lower Factor V (p=0.002) at 3-12 hours after administration with persistent hypofibrinogenaemia at 24h (p=0.011), while only minor hypoplasminogenaemia (P=0.029) was seen in the tenecteplase group. Tenecteplase consumed less plasminogen (p<0.001) and fibrinogen (p=0.002) compared with alteplase. In a pooled analysis, tenecteplase 0.25mg/kg had the greatest odds to achieve early neurological improvement (OR [95%CI] 3.3 [1.5, 7.2], p=0.093), excellent functional outcome (mRS 0-1) at three months (OR [95%CI] 1.9 [0.8, 4.4], p= 0.28), with reduced odds of ICH (OR [95%CI] 0.6 [0.2, 1.8], P=0.43) compared with alteplase. Only 19 patients were treated with tenecteplase 0.4mg/kg, which showed increased odds of SICH compared with alteplase (OR [95% CI] 6.2 [0.7, 56.3]). In the two studies where advanced imaging was performed, the imaging outcomes did not differ in the IPD analysis. Conclusion: Tenecteplase 0.25 mg/kg has the potential to be a better alternative to alteplase. It can be given as a single bolus, does not cause disruption to systemic coagulation, and is possibly safer and more effective in clot lysis. Further phase III study to compare tenecteplase and alteplase in acute ischaemic stroke is warranted.

Pressure ulcer management in Oman: nurses’ knowledge and views

Background: Pressure ulcers (PrUs) have a significant impact on health system expenditure and patient’s quality of life. It is a global problem. Many studies were undertaken in regard to PrU prevention and management. In Oman, no studies have been conducted to investigate nurses’ knowledge on prevention and management of PrUs. The purpose of this descriptive sequential explanatory mixed-method study was to explore the nurses’ level of knowledge in relation to prevention and management of PrUs in Oman. Methods: A mixed method design was used and the study was conducted over two Phases. In Phase I, a questionnaire was developed to explore nurses’ knowledge on PrU, policy, and resources. The main section of the questionnaire was the Pieper-Zulkowski Pressure Ulcer knowledge test (PZ-PUKT) which tests the knowledge on PrU. Another two sections were developed including questions about wound policy and resources available for PrU prevention and management in Oman. The questionnaire was distributed to nurses who were working in surgical, medical, orthopaedic, CCU, and ICU wards/units in seven hospitals. In Phase II study, semi-structured qualitative interviews were conducted with 16 of the questionnaire respondents. Interviews took approximately 30 minutes, were recorded and transcribed verbatim. Qualitative data were analysed using the Knowledge, Attitudes and Practice (KAP) model as the a priori framework. Results: In Phase I, 478 questionnaires were analysed. The knowledge test results showed the overall mean percent score for correctly answered questions was 51% suggesting a low level of knowledge. There was a significant relationship between nurses’ knowledge and age (P=0.001) and between knowledge and years of experience (P=0.001) with knowledge increasing with age and years of experience. In Phase II, four themes were identified from the interviews: knowledge, attitude, and practice (framework themes) and perception of role. Findings indicated positive and negative attitudes towards the care of PrUs. Some nurses stated feeling rewarded when they see wounds improving while others said they could not work with patients independently because they lacked the knowledge and the skills needed. There was variation in the management of PrU between hospitals. Both studies indicated that the wound management policy did not include enough information to guide nurses. Conclusion: Overall the nurses’ level of knowledge on PrU was relatively low. Most nurses were not familiar with wound management policy or different PrU prevention and management strategies. Nurses are aware of the risk of PrUs and try their best to manage them with the available resources however more training is required.

A randomised controlled trial of triple antiplatelet therapy (Aspirin, Clopidogrel and Dipyridamole) in the secondary prevention of stroke: safety, tolerability and feasibility

Background: Aspirin, dipyridamole and clopidogrel are effective in secondary vascular prevention. Combination therapy with three antiplatelet agents might maximise the benefit of antiplatelet treatment in the secondary prevention of ischaemic stroke. Methodology/Principal Findings: A randomised, parallel group, observer-blinded phase II trial compared the combination of aspirin, clopidogrel and dipyridamole with aspirin alone. Adult patients with ischaemic stroke or transient ischaemic attack (TIA) within 5 years were included. The primary outcome was tolerability to treatment assessed as the number of patients completing randomised treatment. Recruitment was halted prematurely after publication of the ESPRIT trial (which confirmed that combined aspirin and dipyridamole is more effective than aspirin alone). 17 patients were enrolled: male 12 (71%), mean age 62 (SD 13) years, lacunar stroke syndrome 12 (71%), median stroke/TIA onset to randomisation 8 months. Treatment was discontinued in 4 of 9 (44%) patients receiving triple therapy vs. none of 8 taking aspirin (p = 0.08). One recurrent stroke occurred in a patient in the triple group who was noncompliant of all antiplatelet medications. The number of patients with adverse events and bleeding complications, and their severity, were significantly greater in the triple therapy group (p,0.01). Conclusions/Significance: Long term triple antiplatelet therapy was asociated with a significant increase in adverse events and bleeding rates, and their severity, and a trend to increased discontinuations. However, the patients had a low risk of recurrence and future trials should focus on short term therapy in high risk patients characterised by a very recent event or failure of dual antiplatelet therapy.

Qualidade de vida, percepção de saúde, resiliência, auto-regulação e suporte social nos adolescentes portugueses com a doencça crónica

Tese de Doutoramento em Psicologia na área de especialidade Psicologia da Saúde

Reproductive performance as affected by lactation status and body fat in beef cows.

Seventy-one mature Brangus cows, 38 nonlactating (NL) and 33 in late stage of lactation (L) were fed for 192 days (Phase I) a low energy diet (L). During Phase II (65 days) 19 NL and 17 L cows were fed a high energy diet (H). The other nonlactating (19) and lactating (16) cows remained on the low energy diet. Energy restriction during Phase I did not affect (P> 0.05) cyclic ovarian activity although losses in body weight and condition were substantial. Rapid changes in body weight, condition, and percent empty body lipe (EBLP) during Phase II did not substantially influencefertility, although a five-fold difference in EBLP was observed (NL0H vs. L-L). Treatment groups did not differ (P> 0.05) in conception rate, days from the beginning of the breeding season to breeding and to conception, conception at first service, and number of services per conception. Values observed for these parameters for NL-H, L-H, NL-L, and L-L groups were respectively: 68,4%, `3,.2, 23.3, 36.8% and 1.68; 82,4% 12.7, 19.5, 58.8% and 1.29; 68.4%, 10.2, 17.4, 47.4%, and 1.41; 68.8%, 12.4, 19.5, 43.7%, and 1.50.

Identification of metabolites of kurarinone from Sophora flavescens Ait in rat urine by ultra-performance liquid chromatography with linear ion trap orbitrap mass spectrometry

Purpose: To study the in vivo metabolism of kurarinone, a lavandulyl flavanone which is a major constituent of Kushen and a marker compound with many biological activities, using ultra-performance liquid chromatography coupled with linear ion trap Orbitrap mass spectrometry (UPLC-LTQ-Orbitrap- MS). Methods: Six male Sprague-Dawley rats were randomly divided into two groups. First, kurarinone was suspended in 0.5 % carboxymethylcellulose sodium (CMC-Na) aqueous solution, and was given to rats (n = 3, 2 mL for each rat) orally at 50 mg/kg. A 2 mL aliquot of 0.5 % CMC-Na aqueous solution was administered to the rats in the control group. Next, urine samples were collected over 0-24 h after the oral administrations and all urine samples were pretreated by a solid phase extraction (SPE) method. Finally, all samples were analyzed by a UPLC-LTQ-Orbitrap mass spectrometry coupled with an electrospray ionization source (ESI) that was operated in the negative ionization mode. Results: A total of 11 metabolites, including the parent drug and 10 phase II metabolites in rat urine, were first detected and interpreted based on accurate mass measurement, fragment ions, and chromatographic retention times. The results were based on the assumption that kurarinone glucuronidation was the dominant metabolite that was excreted in rat urine. Conclusion: The results from this work indicate that kurarinone in vivo is typically transformed to nontoxic glucuronidation metabolites, and these findings may help to characterize the metabolic profile of kurarinone.

Biologia reprodutiva da Tainha, Mugil curema valenciennes, 1836 (osteichthyes: mugilidade) nas águas costeiras do Rio Grande do Norte

The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.

L'activité tonique diaphragmatique chez les enfants avec et sans support respiratoire

Introduction : Les nourrissons, vu la grande compliance de leur cage thoracique, doivent maintenir activement leur volume pulmonaire de fin d’expiration (VPFE). Ceci se fait par interruption précoce de l’expiration, et par le freinage expiratoire au niveau laryngé et par la persistance de la contraction des muscles inspiratoires. Chez les nourrissons ventilés mécaniquement, notre équipe a montré que le diaphragme est activé jusqu’à la fin de l’expiration (activité tonique). Il n’est pas clair si cette activité tonique diaphragmatique compense pour l’absence de freinage laryngé liée à l’intubation endotrachéale. Objectif : Notre objectif est de déterminer si l’activité tonique diaphragmatique persiste après l’extubation chez les nourrissons et si elle peut être observée chez les enfants plus âgés. Méthode : Ceci est une étude observationnelle longitudinale prospective de patients âgés de 1 semaine à 18 ans admis aux soins intensifs pédiatriques (SIP), ventilés mécaniquement pour >24 heures et avec consentement parental. L’activité électrique du diaphragme (AEdi) a été enregistrée à l’aide d’une sonde nasogastrique spécifique à 4 moments durant le séjour aux SIP : en phase aigüe, pré et post-extubation et au congé. L’AEdi a été analysée de façon semi-automatique. L’AEdi tonique a été définie comme l’AEdi durant le dernier quartile de l’expiration. Résultats : 55 patients avec un âge médian de 10 mois (écart interquartile: 1-48) ont été étudiés. Chez les nourrissons (<1an, n=28), l’AEdi tonique en pourcentage de l’activité inspiratoire était de 48% (30-56) en phase aigüe, 38% (25-44) pré-extubation, 28% (17-42) post-extubation et 33% (22-43) au congé des SIP (p<0.05, ANOVA, avec différence significative entre enregistrements 1 et 3-4). Aucun changement significatif n’a été observé pré et post-extubation. L’AEdi tonique chez les patients plus âgés (>1an, n=27) était négligeable en phases de respiration normale (0.6mcv). Par contre, une AEdi tonique significative (>1mcv et >10%) a été observée à au moins un moment durant le séjour de 10 (37%) patients. La bronchiolite est le seul facteur indépendant associé à l’activité tonique diaphragmatique. Conclusion : Chez les nourrissons, l’AEdi tonique persiste après l’extubation et elle peut être réactivée dans certaines situations pathologiques chez les enfants plus âgés. Elle semble être un indicateur de l’effort du patient pour maintenir son VPFE. D’autres études devraient être menées afin de déterminer si la surveillance de l’AEdi tonique pourrait faciliter la détection de situations de ventilation inappropriée.

Essays on Emissions Trading Markets

This dissertation is a collection of three economics essays on different aspects of carbon emission trading markets. The first essay analyzes the dynamic optimal emission control strategies of two nations. With a potential to become the largest buyer under the Kyoto Protocol, the US is assumed to be a monopsony, whereas with a large number of tradable permits on hand Russia is assumed to be a monopoly. Optimal costs of emission control programs are estimated for both the countries under four different market scenarios: non-cooperative no trade, US monopsony, Russia monopoly, and cooperative trading. The US monopsony scenario is found to be the most Pareto cost efficient. The Pareto efficient outcome, however, would require the US to make side payments to Russia, which will even out the differences in the cost savings from cooperative behavior. The second essay analyzes the price dynamics of the Chicago Climate Exchange (CCX), a voluntary emissions trading market. By examining the volatility in market returns using AR-GARCH and Markov switching models, the study associates the market price fluctuations with two different political regimes of the US government. Further, the study also identifies a high volatility in the returns few months before the market collapse. Three possible regulatory and market-based forces are identified as probable causes of market volatility and its ultimate collapse. Organizers of other voluntary markets in the US and worldwide may closely watch for these regime switching forces in order to overcome emission market crashes. The third essay compares excess skewness and kurtosis in carbon prices between CCX and EU ETS (European Union Emission Trading Scheme) Phase I and II markets, by examining the tail behavior when market expectations exceed the threshold level. Dynamic extreme value theory is used to find out the mean price exceedence of the threshold levels and estimate the risk loss. The calculated risk measures suggest that CCX and EU ETS Phase I are extremely immature markets for a risk investor, whereas EU ETS Phase II is a more stable market that could develop as a mature carbon market in future years.

Assessment of the Occurrence and Potential Risks of Pharmaceuticals and their Metabolites in Fish and Water Using Liquid Chromatography Mass Spectrometry

A comprehensive method for the analysis of 11 target pharmaceuticals representing multiple therapeutic classes was developed for biological tissues (fish) and water. Water samples were extracted using solid phase extraction (SPE), while fish tissue homogenates were extracted using accelerated solvent extraction (ASE) followed by mixed-mode cation exchange SPE cleanup and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Among the 11 target pharmaceuticals analyzed, trimethoprim, caffeine, sulfamethoxazole, diphenhydramine, diltiazem, carbamazepine, erythromycin and fluoxetine were consistently detected in reclaimed water. On the other hand, caffeine, diphenhydramine and carbamazepine were consistently detected in fish and surface water samples. In order to understand the uptake and depuration of pharmaceuticals as well as bioconcentration factors (BCFs) under the worst-case conditions, mosquito fish were exposed to reclaimed water under static-renewal for 7 days, followed by a 14-day depuration phase in clean water. Characterization of the exposure media revealed the presence of 26 pharmaceuticals while 5 pharmaceuticals including caffeine, diphenhydramine, diltiazem, carbamazepine, and ibuprofen were present in the organisms as early as 5 h from the start of the exposure. Liquid chromatography ultra-high resolution Orbitrap mass spectrometry was explored as a tool to identify and quantify phase II pharmaceutical metabolites in reclaimed water. The resulting data confirmed the presence of acetyl-sulfamethoxazole and sulfamethoxazole glucuronide in reclaimed water. To my knowledge, this is the first known report of sulfamethoxazole glucuronide surviving intact through wastewater treatment plants and occurring in environmental water samples. Finally, five bioaccumulative pharmaceuticals including caffeine, carbamazepine, diltiazem, diphenhydramine and ibuprofen detected in reclaimed water were investigated regarding the acute and chronic risks to aquatic organisms. The results indicated a low potential risk of carbamazepine even under the worst case exposure scenario. Given the dilution factors that affect environmental releases, the risk of exposure to carbamazepine will be even more reduced.

Geographical literacy, attitudes, and experiences of freshman students: A qualitative study at Florida International University

The purpose of the study was to explore the geography literacy, attitudes and experiences of Florida International University (FIU) freshman students scoring at the low and high ends of a geography literacy survey. The Geography Literacy and ABC Models formed the conceptual framework. Participants were freshman students enrolled in the Finite Math course at FIU. Since it is assumed that students who perform poorly on geography assessments do not have an interest in the subject, testing and interviewing students allowed the researcher to explore the assumption. ^ In Phase I, participants completed the Geography Literacy Survey (GLS) with items taken from the 2010 NAEP Geography Subject Area Assessment. The low 35% and high 20% performers were invited for Phase II, which consisted of semi-structured interviews. A total of 187 students participated in Phase I and 12 in Phase II. ^ The primary research question asked was what are the geography attitudes and experiences of freshman students scoring at the low and high ends of a geographical literacy survey? The students had positive attitudes regardless of how they performed on the GLS. ^ The study included a quantitative sub-question regarding the performance of the students on the GLS. The students’ performance on the GLS was equivalent to the performance of 12th grade students from the NAEP Assessment. There were three qualitative sub-questions from which the following themes were identified: the students’ definition of geography is limited, students recall more out of school experiences with geography, and students find geography valuable. In addition, there were five emergent themes: there is a concern regarding a lack of geographical knowledge, rote memorization of geographical content is overemphasized, geographical concepts are related to other subjects, taking the high school level AP Human Geography course is powerful, and there is a need for real-world applications of geographical knowledge. ^ The researcher offered as suggestions for practice to reposition geography in our schools to avoid misunderstandings, highlight its interconnectedness to other fields, connect the material to real world events/daily decision-making, make research projects meaningful, partner with local geographers, and offer a mandatory geography courses at all educational levels.^

Assessment of the Occurrence and Potential Risks of Antibiotics and their Metabolites in South Florida Waters Using Liquid Chromatography Tandem Mass Spectrometry

An automated on-line SPE-LC-MS/MS method was developed for the quantitation of multiple classes of antibiotics in environmental waters. High sensitivity in the low ng/L range was accomplished by using large volume injections with 10-mL of sample. Positive confirmation of analytes was achieved using two selected reaction monitoring (SRM) transitions per antibiotic and quantitation was performed using an internal standard approach. Samples were extracted using online solid phase extraction, then using column switching technique; extracted samples were immediately passed through liquid chromatography and analyzed by tandem mass spectrometry. The total run time per each sample was 20 min. The statistically calculated method detection limits for various environmental samples were between 1.2 and 63 ng/L. Furthermore, the method was validated in terms of precision, accuracy and linearity. The developed analytical methodology was used to measure the occurrence of antibiotics in reclaimed waters (n=56), surface waters (n=53), ground waters (n=8) and drinking waters (n=54) collected from different parts of South Florida. In reclaimed waters, the most frequently detected antibiotics were nalidixic acid, erythromycin, clarithromycin, azithromycin trimethoprim, sulfamethoxazole and ofloxacin (19.3-604.9 ng/L). Detection of antibiotics in reclaimed waters indicates that they can’t be completely removed by conventional wastewater treatment process. Furthermore, the average mass loads of antibiotics released into the local environment through reclaimed water were estimated as 0.248 Kg/day. Among the surface waters samples, Miami River (reaching up to 580 ng/L) and Black Creek canal (up to 124 ng/L) showed highest concentrations of antibiotics. No traces of antibiotics were found in ground waters. On the other hand, erythromycin (monitored as anhydro erythromycin) was detected in 82% of the drinking water samples (n.d-66 ng/L). The developed approach is suitable for both research and monitoring applications. Major metabolites of antibiotics in reclaimed wates were identified and quantified using high resolution benchtop Q-Exactive orbitrap mass spectrometer. A phase I metabolite of erythromycin was tentatively identified in full scan based on accurate mass measurement. Using extracted ion chromatogram (XIC), high resolution data-dependent MS/MS spectra and metabolic profiling software the metabolite was identified as desmethyl anhydro erythromycin with molecular formula C36H63NO12 and m/z 702.4423. The molar concentration of the metabolite to erythromycin was in the order of 13 %. To my knowledge, this is the first known report on this metabolite in reclaimed water. Another compound acetyl-sulfamethoxazole, a phase II metabolite of sulfamethoxazole was also identified in reclaimed water and mole fraction of the metabolite represent 36 %, of the cumulative sulfamethoxazole concentration. The results were illustrating the importance to include metabolites also in the routine analysis to obtain a mass balance for better understanding of the occurrence, fate and distribution of antibiotics in the environment. Finally, all the antibiotics detected in reclaimed and surface waters were investigated to assess the potential risk to the aquatic organisms. The surface water antibiotic concentrations that represented the real time exposure conditions revealed that the macrolide antibiotics, erythromycin, clarithromycin and tylosin along with quinolone antibiotic, ciprofloxacin were suspected to induce high toxicity to aquatic biota. Preliminary results showing that, among the antibiotic groups tested, macrolides posed the highest ecological threat, and therefore, they may need to be further evaluated with, long-term exposure studies considering bioaccumulation factors and more number of species selected. Overall, the occurrence of antibiotics in aquatic environment is posing an ecological health concern.