Response of photosynthetic organisms to global change: an approach based on marker pigments

Report for the scientific sojourn carried out at the Department of Freshwater Ecology, National Environmetal Research Institute, Denmark, from 2006 to 2008. The main objective of the project was to reconstruct photosynthetic organism community composition using pigmentbased methods and to study their response to natural (e.g. climate) or anthropogenic (e.g. eutrophication) perturbations that took place in the system over time. We performed a study in different locations and at different temporal scales. We analysed the pigment composition in a short sediment record (46 cm sediment depth) of a volcanic lake (Lake Furnas) in the Azores Archipelago (Portugal). The lake has been affected during the last century by successive fish introductions. The specific objective was to reconstruct the lake’s trophic state history and to assess the role of land-use, climate and fish introductions in structuring the lake community. Results obtained suggested that whereas trophic cascade and changes in nutrient concentrations have some clear effects on algal and microbial assemblages, interpreting the effects of changes in climate are not straightforward. This is probably related with the rather constant precipitation in the Azores Islands during the studied period. We also analysed the pigment composition in a long sediment record (1800 cm sediment depth) of Lake Aborre (Denmark) covering ca. 8kyr of lake history. The specific objective was to describe changes in lake primary production and lake trophic state over the Holocene and to determine the photosynthetic organisms involved. Results suggested that external forcing (i.e. land use changes) was responsible of erosion and nutrient run off to the lake that contributed to the reported changes in lake primary production along most of the Holocene.

Monitoring switch-type sensors and powering autonomous sensors via inductive coupling: application to removable seats in vehicles

Aquesta tesi explora la possibilitat de fer servir enllaços inductius per a una aplicació de l’automòbil on el cablejat entre la centraleta (ECU) i els sensors o detectors és difícil o impossible. S’han proposat dos mètodes: 1) el monitoratge de sensors commutats (dos possibles estats) via acoblament inductiu i 2) la transmissió mitjançant el mateix principi físic de la potència necessària per alimentar els sensors autònoms remots. La detecció d'ocupació i del cinturó de seguretat per a seients desmuntables pot ser implementada amb sistemes sense fils passius basats en circuits ressonants de tipus LC on l'estat dels sensors determina el valor del condensador i, per tant, la freqüència de ressonància. Els canvis en la freqüència són detectats per una bobina situada en el terra del vehicle. S’ha conseguit provar el sistema en un marge entre 0.5 cm i 3 cm. Els experiments s’han dut a terme fent servir un analitzador d’impedàncies connectat a una bobina primària i sensors comercials connectats a un circuit remot. La segona proposta consisteix en transmetre remotament la potència des d’una bobina situada en el terra del vehicle cap a un dispositiu autònom situat en el seient. Aquest dispositiu monitorarà l'estat dels detectors (d'ocupació i de cinturó) i transmetrà les dades mitjançant un transceptor comercial de radiofreqüència o pel mateix enllaç inductiu. S’han avaluat les bobines necessàries per a una freqüència de treball inferior a 150 kHz i s’ha estudiat quin és el regulador de tensió més apropiat per tal d’aconseguir una eficiència global màxima. Quatre tipus de reguladors de tensió s’han analitzat i comparat des del punt de vista de l’eficiència de potència. Els reguladors de tensió de tipus lineal shunt proporcionen una eficiència de potència millor que les altres alternatives, els lineals sèrie i els commutats buck o boost. Les eficiències aconseguides han estat al voltant del 40%, 25% i 10% per les bobines a distàncies 1cm, 1.5cm, i 2cm. Les proves experimentals han mostrat que els sensors autònoms han estat correctament alimentats fins a distàncies de 2.5cm.

Simple and fast methods based on solid-phase extraction coupled to liquid chromatography with UV detection for the monitoring of caffeine in natural and waste waters as marker of anthropogenic impact

Two concentration methods for fast and routine determination of caffeine (using HPLC-UV detection) in surface, and wastewater are evaluated. Both methods are based on solid-phase extraction (SPE) concentration with octadecyl silica sorbents. A common “offline” SPE procedure shows that quantitative recovery of caffeine is obtained with 2 mL of an elution mixture solvent methanol-water containing at least 60% methanol. The method detection limit is 0.1 μg L−1 when percolating 1 L samples through the cartridge. The development of an “online” SPE method based on a mini-SPE column, containing 100 mg of the same sorbent, directly connected to the HPLC system allows the method detection limit to be decreased to 10 ng L−1 with a sample volume of 100 mL. The “offline” SPE method is applied to the analysis of caffeine in wastewater samples, whereas the “on-line” method is used for analysis in natural waters from streams receiving significant water intakes from local wastewater treatment plants

PCR detection of the pKM.19/ScrfI RFLP (D7S23), a marker closely linked to the cystic fibrosis mutation

Source: Description: pKM-19 is a 1.0 kb EcoRI human genomic fragment inserted in pUC13, that detects a Scrfl (CC/NGG) RFLP (1, 2). We report here the primer sequences suitable for the detection of this RFLP by PCR...

High amplitude contractions in the middle third of the esophagus: a manometric marker of chronic alcoholism?

BACKGROUND--Oesophageal motor abnormalities have been reported in alcoholism. AIM--To investigate the effects of chronic alcoholism and its withdrawal on oesophageal disease. PATIENTS--23 chronic alcoholic patients (20 men and three women; mean age 43, range 23 to 54). METHODS--Endoscopy, manometry, and 24 hour pH monitoring 7-10 days and six months after ethanol withdrawal. Tests for autonomic and peripheral neuropathy were also performed. Motility and pH tracings were compared with those of age and sex matched control groups: healthy volunteers, nutcracker oesophagus, and gastro-oesophageal reflux disease. RESULTS--14 (61%) alcoholic patients had reflux symptoms, and endoscopy with biopsy showed oesophageal inflammation in 10 patients. One patient had an asymptomatic squamous cell carcinoma. Oesophageal motility studies in the alcoholic patients showed that peristaltic amplitude in the middle third was > 150 mm Hg (95th percentile (P95) of healthy controls) in 13 (57%), the ratio lower/ middle amplitude was < 0.9 in 15 (65%) (> 0.9 in all control groups), and the lower oesophageal sphincter was hypertensive (> 23.4 mm Hg, P95 of healthy controls) in 13 (57%). All three abnormalities were present in five (22%). Abnormal reflux (per cent reflux time > 2.9, P95 of healthy controls) was shown in 12 (52%) alcoholic patients, and was unrelated to peristaltic dysfunction. Subclinical neuropathy in 10 patients did not effect oesophageal abnormalities. Oesophageal motility abnormalities persisted at six months in six patients with ongoing alcoholism, whereas they reverted towards normal in 13 who remained abstinent; reflux, however, was unaffected. CONCLUSIONS--Oesophageal peristaltic dysfunction and reflux are frequent in alcoholism. High amplitude contractions in the middle third of the oesophagus seem to be a marker of excessive alcohol consumption, and tend to improve with abstinence.

Application of a floating well concept to a latch-up-free, low-cost, smart power high-side switch technology

The aim of this brief is to present an original design methodology that permits implementing latch-up-free smart power circuits on a very simple, cost-effective technology. The basic concept used for this purpose is letting float the wells of the MOS transistors most susceptible to initiate latch-up.

The switch from conventional to atypical antipsychotic treatment should not be based exclusively on the presence of cognitive deficits. A pilot study in individuals with schizophrenia.

Background: Atypical antipsychotics provide better control of the negative and affective symptoms of schizophrenia when compared with conventional neuroleptics; nevertheless, their heightened ability to improve cognitive dysfunction remains a matter of debate. This study aimed to examine the changes in cognition associated with long-term antipsychotic treatment and to evaluate the effect of the type of antipsychotic (conventional versus novel antipsychotic drugs) on cognitive performance over time. Methods: In this naturalistic study, we used a comprehensive neuropsychological battery of tests to assess a sample of schizophrenia patients taking either conventional (n = 13) or novel antipsychotics (n = 26) at baseline and at two years after. Results: Continuous antipsychotic treatment regardless of class was associated with improvement on verbal fluency, executive functions, and visual and verbal memory. Patients taking atypical antipsychotics did not show greater cognitive enhancement over two years than patients taking conventional antipsychotics. Conclusions Although long-term antipsychotic treatment slightly improved cognitive function, the switch from conventional to atypical antipsychotic treatment should not be based exclusively on the presence of these cognitive deficits.

High amplitude contractions in the middle third of the esophagus: a manometric marker of chronic alcoholism?

BACKGROUND--Oesophageal motor abnormalities have been reported in alcoholism. AIM--To investigate the effects of chronic alcoholism and its withdrawal on oesophageal disease. PATIENTS--23 chronic alcoholic patients (20 men and three women; mean age 43, range 23 to 54). METHODS--Endoscopy, manometry, and 24 hour pH monitoring 7-10 days and six months after ethanol withdrawal. Tests for autonomic and peripheral neuropathy were also performed. Motility and pH tracings were compared with those of age and sex matched control groups: healthy volunteers, nutcracker oesophagus, and gastro-oesophageal reflux disease. RESULTS--14 (61%) alcoholic patients had reflux symptoms, and endoscopy with biopsy showed oesophageal inflammation in 10 patients. One patient had an asymptomatic squamous cell carcinoma. Oesophageal motility studies in the alcoholic patients showed that peristaltic amplitude in the middle third was > 150 mm Hg (95th percentile (P95) of healthy controls) in 13 (57%), the ratio lower/ middle amplitude was < 0.9 in 15 (65%) (> 0.9 in all control groups), and the lower oesophageal sphincter was hypertensive (> 23.4 mm Hg, P95 of healthy controls) in 13 (57%). All three abnormalities were present in five (22%). Abnormal reflux (per cent reflux time > 2.9, P95 of healthy controls) was shown in 12 (52%) alcoholic patients, and was unrelated to peristaltic dysfunction. Subclinical neuropathy in 10 patients did not effect oesophageal abnormalities. Oesophageal motility abnormalities persisted at six months in six patients with ongoing alcoholism, whereas they reverted towards normal in 13 who remained abstinent; reflux, however, was unaffected. CONCLUSIONS--Oesophageal peristaltic dysfunction and reflux are frequent in alcoholism. High amplitude contractions in the middle third of the oesophagus seem to be a marker of excessive alcohol consumption, and tend to improve with abstinence.

Establishing Zebrafish as a Novel Exercise Model: Swimming Economy, Swimming-enhanced Growth and Muscle Growth Marker Gene Expression

Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish.