Molecular basis of autotrophic vs mixotrophic growth in Chlorella sorokiniana.

In this work, we investigated the molecular basis of autotrophic vs. mixotrophic growth of Chlorella sorokiniana, one of the most productive microalgae species with high potential to produce biofuels, food and high value compounds. To increase biomass accumulation, photosynthetic microalgae are commonly cultivated in mixotrophic conditions, adding reduced carbon sources to the growth media. In the case of C. sorokiniana, the presence of acetate enhanced biomass, proteins, lipids and starch productivity when compared to autotrophic conditions. Despite decreased chlorophyll content, photosynthetic properties were essentially unaffected while differential gene expression profile revealed transcriptional regulation of several genes mainly involved in control of carbon flux. Interestingly, acetate assimilation caused upregulation of phosphoenolpyruvate carboxylase enzyme, enabling potential recovery of carbon atoms lost by acetate oxidation. The obtained results allowed to associate the increased productivity observed in mixotrophy in C. sorokiniana with a different gene regulation leading to a fine regulation of cell metabolism.

Cortical inhibition in Parkinson's disease: new insights from early, untreated patients.

Transcranial magnetic stimulation (TMS) has opened important perspectives on the pathophysiological bases and potential targets of treatment strategies for idiopathic Parkinson's disease (IPD). Studies have been mainly focusing on motor cortical inhibitory phenomena. However, differences in patients and methods caused several discrepancies, particularly on the so-called long-latency cortical inhibition (LICI). We wanted to challenge such controversies by studying early, drug-naïve patients, and by reproducing the original method that detected a pathologic LICI in IPD. We studied the motor potentials evoked in the first dorsal interosseous muscle on the more and the less parkinsonian side of the body in 18 asymmetrical untreated IPD patients in the early stages of their disease. We had 12 healthy controls. The TMS variables were the active motor threshold, the size of the motor-evoked potential, the cortical silent period and LICI. Average active motor threshold was similar in patients and controls, but its variability was significantly higher among patients (P<0.05). There was a trend for the cortical silent period to be shorter on the more affected side of the patients (P=0.1). Patients, especially on their more affected side, exhibited a late LICI peak, which was absent among controls (P<0.05). This effect was independent of the silent period duration. However, patients and controls having a short silent period also had a shorter LICI (P<0.05). Changes in LICI had a strong trend to correlate to the severity of the parkinsonian signs (P=0.1). Thus, the present study definitely reinforced several previous TMS findings in IPD as a feature of the "pure" disease pathophysiology. The pathologic enhancement of late LICI can act as a candidate physiological hallmark of IPD, to be tested in various diagnostic or therapeutic circumstances.

Cortical excitability in drug-naive patients with partial epilepsy: a cross-sectional study.

OBJECTIVE: To use paired-pulse transcranial magnetic stimulation (TMS) to investigate cortical excitability in drug-naive patients with partial epilepsy. METHODS: Twenty-one drug-naive patients with partial epilepsy and 15 control subjects were studied. The relaxed threshold to TMS, the central silent period, and the intracortical inhibition/facilitation were measured. Statistics implied cluster analysis methods. Also assessed were the patient interictal EEG epileptiform abnormalities (EAs) on a semiquantitative basis. Then the TMS was contrasted to the clinical and EEG findings, using chi2 or Fisher exact tests. RESULTS: One-third of the patients made up a "pathologic" cluster with a disrupted intracortical inhibition (p < 0.01). Two-thirds had a normal inhibition. Interictal EAs predominated in the pathologic cluster, for frequency (p < 0.04), duration (p < 0.04), and focality (p < 0.02). CONCLUSIONS: Intracortical inhibition, which was impaired in one-third of the patients, reflects gamma-aminobutyric acid (GABA) activity within cortical area 4. Defective GABA inhibition is a typical pathogenic factor in partial epilepsy. Transcranial magnetic stimulation proved able to detect it. The weaker cortical inhibition had a direct relation to the severity of interictal epileptiform abnormalities.

Enactment of virtue ethics: collaboration between nurse academics and international students in questionnaire design.

Increased enrolment of international nursing students in undergraduate and postgraduate programs is predicted as Australian universities compete for students in the globalised university market. This study explored issues impacting on the ability of international nursing students to achieve their study goals at an Australian university (n=29). However, this paper principally describes the design of the instrument by two nursing lecturers and international nursing students (n=10) in a collaborative process, characterised by a pluralistic world view and the enactment of virtue ethics. The myth of the term 'ESL' is critiqued, and challenged. In designing the instrument, we argued it was essential to be cognisant of the conceptual attributes and embedded meanings of language for the unique study population, to ensure face and content validity.

International nurse education: implications for providers.

This exploratory study conducted in 1996 described the profiles, roles and preparation of twelve South Australian registered nurses in relation to their provision of education programs for nurses from South East Asia. The research showed respondents were well qualified and highly experienced educators whose roles were complex. Their preparation for providing education programs for nurse from South East Asia had been haphazard and inadequate. Consequently respondents considered they were not fully prepared for the providing this specialised education. Career planning and a more strategic approach to the development of specific expertise are essential to support an international approach to nurse education. Nurse education that values intercultural awareness, and is multicultural and global would benefit both local and international students. Development of germane knowledge, skill, attitudes and behaviours is recommended to ensure excellence in the provision of international nurse education. An action research model is proposed as an alternative to traditional professional development to prepare providers of international education.