Modeling Dynamical Positional Physical Data on Field Zones Occupied by Playing Positions in Elite-Level Futsal: A Comparison Between Running Velocities, Accelerations, and Decelerations.

ABSTRACT: Serrano, C, Felipe, JL, García-Unanue, J, Vicente Gimenez, J, Jiménez-Linares, L, Ibáñez, E, Hernando, E, Gallardo, L, and Sánchez-Sánchez, J. Modeling dynamical positional physical data on field zones occupied by playing positions in elite-level futsal: a comparison between running velocities, acceleration, and deceleration. J Strength Cond Res 37(1): 200-206, 2023-The aim of this study was to analyze the influence of playing positions on the physical demands and the specific court zones occupied during official futsal games. The total number of observations were 188, corresponding to 8 matches from the first division of the Spanish Futsal League during the 2019-2020 season. All dynamic motion representations were recorded using an 18 Hz device with ultra-wideband technology and local positioning system installed on the futsal pitch for each position. Python Data Analysis Library, Matplotlib, and Python programming language were applied as computational tools to generate visual analysis of figures to represent every physical demand analyzed. An analysis of variance test showed differences between playing positions, specifically, for winger position (p < 0.05). Based on eta-square coefficients, all variables showed large effects, except acceleration distance zone 1 (1-2 m·s-2). Accordingly, the visual representation of positional dynamic motion data showed differences in the physical demands and the court zone occupied by the different playing positions. This innovative visual analysis allows fitness coaches to associate the physical demands with court zones occupied by different playing positions, and it aids in the design of training drills associated with futsal competition requirements.

Characterisation of Goal Scoring Patterns during Open Play Related to Zone Pitch Division and Number of Players Involved in the 2018 FIFA World Cup.

The aim of this study was to characterise all the goal scoring patterns during open play (elaborate attacks versus counterattacks) related to zone pitch division and the number of players involved in the 2018 FIFA World Cup in Russia. An Iterative Dichotomiser 3 (ID3) decision tree algorithm was used to classify all the goal scoring patterns (94 goals in 64 matches). The results did not show statistical differences between the type of scoring goal during the 2018 FIFA World Cup (p > 0.05; ES = Moderate). According to the result of the patterns of how the goals were achieved, an ID3 algorithm decision tree with seven classification decision nodes was calculated. Consequently, this study may aid national team coaches for the next World Cup to establish notational analyses and spatial-temporal relations to understand how scoring patterns during open play are related to zone pitch division and the number of players involved.

Magnetic resonance imaging assessment in patients with axial spondyloarthritis: development of checklists for use in clinical practice.

The objective of our study was to standardize magnetic resonance imaging (MRI) assessment of spine and sacroiliac joints in patients with axial spondyloarthritis (axSpA) and/or inflammatory spinal pain, by creating checklists and templates based on the opinions of rheumatologists and radiologists. A scientific committee developed a series of questionnaires with multiple items regarding MRI in patients with axial inflammatory pain and/or axSpA. Then an expert panel of rheumatologists and radiologists rated all items in a 9-point Likert scale. Finally, the scientific committee and the expert panel met to create the definitive documents. Several definitive checklists and templates were generated for rheumatologist-requested MRI and for radiologist-requested MRI reports of sacroiliac joint and spinal examinations. A technical requirement protocol was also agreed on. Our results could be useful in increasing understanding between rheumatologists and radiologists regarding MRI in axSpA diagnosis and follow-up.

Prevalence and characteristics associated with dactylitis in patients with early spondyloarthritis: results from the ESPeranza cohort.

OBJECTIVES: Dactylitis is a typical feature of psoriatic arthritis. However, dactylitis was included as a spondyloarthritis (SpA) feature for both (axial and peripheral) of the ASAS classification criteria, but data about its prevalence are scarce, especially in patients with a recent onset of the disease. Our objective was to determine the prevalence and characteristics associated with dactylitis in patients with early SpA. METHODS: A baseline dataset from the ESPeranza cohort was used. This programme included patients who were suspected of having SpA (age <45 years, symptoms duration of 3-24 months and with inflammatory back pain, or asymmetrical arthritis, or spinal/joint pain plus ≥1 of the SpA features). For this study, 609 patients who were diagnosed with SpA by their physician were included. Descriptive, univariable and multivariable logistic regression analyses were employed to investigate the association between the presence of dactylitis and the characteristics associated with SpA. RESULTS: Fifty-eight (9.5%) patients currently or previously had dactylitis. In the multivariable analysis, dactylitis was independently associated with peripheral arthritis (OR= 4.83; p<0.001), enthesitis (OR= 2.49; p=0.01), psoriasis (OR= 3.62; p<0.01) and the physician's visual analogue scale (OR= 0.82; p=0.01). However, 67% of the patients who had dactylitis did not have peripheral arthritis or psoriasis and 15% had predominantly axial disease. CONCLUSIONS: Dactylitis is a frequent manifestation in patients with SpA, even during the early stages of the disease. Its presence is mainly associated with peripheral manifestations and psoriasis. Nevertheless, dactylitis is not exclusive of patients with PsA or peripheral manifestations.

Should over-treatment of axial spondyloarthritis with biologics remain a concern after the issue of the new ASAS criteria? Data from REGISPONSERBIO (Spanish Register of Biological Therapy in Spondyloarthritides).

OBJECTIVES: To study whether disease status at treatment initiation has changed after the issue of the ASAS classification criteria. METHODS: REGISPONSERBIO registers patients with axial spondyloarthritis (axSpA) on biological treatment since 2013. It includes patients starting biological treatment (incident) or already on biological therapies (prevalent). Patients in both groups were compared in terms of: age at disease onset and at treatment start, disease duration, gender, HLA-B27, body mass index (BMI), BASDAI, BASFI, C-reactive protein, ESR, metrological data, ASQoL, WAPAI, extra-articular manifestations, comorbidities, radiological study, type of biological treatment and concomitant treatments. RESULTS: 256 patients were included, of whom 174 (65%) were already on biologic therapy. Compared to incident patients, prevalent patients started treatment with longer disease duration (15 vs. 8.6 years; p<0.001), a higher proportion of them were men (83% vs. 67%; p=0.01), a smaller proportion of them showed non-radiographic axial spondylarthritis (nr-axSpA)(17% vs. 32%; p<0.01), and a higher proportion had HLAB27 (85% vs. 73%; p=0.02). There were no statistically significant differences in terms of disease activity, degree of disability, quality of life, or prevalence of extra-articular manifestations. CONCLUSIONS: Data suggest that, after the issue of the new classification criteria for SpA, biological therapy is being administered earlier than previously in SpA patients and in a higher proportion of patients with nr-axSpA. However, this change in prescribing profile, apparently, has not caused an over-treatment, as patients do not seem to have a lower disease burden than prior to the issue of the criteria.

The EJES-3D tool for personalized prescription of exercise in axial spondyloarthritis through multimedia animations: pilot study.

To develop and evaluate a web application based on multimedia animations, combined with a training program, to improve the prescription of exercises in spondyloarthritis (SpA). After a review of exercises included in the main clinical trials and recommendations of international societies, a multidisciplinary team-rehabilitators, rheumatologists, physiotherapists, computer scientists and graphic designers-developed a web application for the prescription of exercises (EJES-3D). Once completed, this was presented to 12 pairs of rehabilitators-rheumatologists from the same hospital in a workshop. Knowledge about exercise was tested in rheumatologists before and 6 months after the workshop, when they also evaluated the application. The EJES-3D application includes 38 multimedia videos and allows prescribing predesigned programs or customizing them. A patient can consult the prescribed exercises at any time from a device with internet connection (mobile, tablet, or computer). The vast majority of the evaluators (89%) were satisfied or very satisfied and considered that their expectations regarding the usefulness of the web application had been met. They highlighted the ability to tailor exercises adapted to the different stages of the disease and the quality and variety of the videos. They also indicated some limitations of the application and operational problems. The EJES-3D tool was positively evaluated by experts in SpA, potentially the most demanding group of users with the most critical capacity. This allows a preliminary validation of the contents, usefulness, and ease of use. Analyzing and correcting the errors and limitations detected is allowing us to improve the EJES-3D tool.

Identification and management of comorbidity in psoriatic arthritis: evidence- and expert-based recommendations from a multidisciplinary panel from Spain.

The objective is to establish recommendations, based on evidence and expert opinion, for the identification and management of comorbidities in patients with psoriatic arthritis (PsA). The following techniques were applied: discussion group, systematic review, and Delphi survey for agreement. A panel of professionals from four specialties defined the users, the sections of the document, possible recommendations, and what systematic reviews should be performed. A second discussion was held with the results of the systematic reviews. Recommendations were formulated in the second meeting and voted online from 1 (total disagreement) to 10 (total agreement). Agreement was considered if at least 70% voted ≥7. The level of evidence and grade of recommendation were assigned using the Oxford Centre for Evidence-Based Medicine guidance. The full document was critically appraised by the experts, and the project was supervised at all times by a methodologist. In a final step, the document was reviewed and commented by a patient and a health management specialist. Fourteen recommendations were produced, together with a checklist to facilitate the implementation. The items with the largest support from evidence were those related to cardiovascular disease and risk factors. The panel recommends paying special attention to obesity, smoking, and alcohol consumption, as they are all modifiable factors with an impact on treatment response or complications of PsA. Psychological and organizational aspects were also deemed important. We herein suggest practical recommendations for the management of comorbidities in PsA based on evidence and expert opinion.

Etoricoxib in ankylosing spondylitis: is there a role for active patients refractory to traditional NSAIDs?

OBJECTIVES: To evaluate the efficacy of etoricoxib in patients with axial ankylosing spondyloarthritis (AS) refractory to traditional NSAIDs. METHODS: This was an open label, multicentric, randomised, prospective (4 weeks with and open extension to 6 months), non-controlled study. Consecutive patients with axial AS refractory to traditional NSAID eligible for anti-TNF-α therapy were selected. The primary outcomes were the rate of patients with good clinical response (not eligible for anti-TNF-α therapy after etoricoxib) and the Assessment of Spondyloarthritis International Society response criteria for biologic therapies (ASASBIO) response at 4 weeks. Secondary outcomes included: ASAS20 and 40 responses, ASDAS-CRP response, BASDAI, BASFI, back and night back pain, global patient and physician assessment of the disease, and biologic parameters like C-reactive protein (CRP) at 2, 4 weeks and 6 months. RESULTS: A total of 57 axial AS patients were recruited, 46 men, with mean age of 43 years. After 4 weeks of treatment, 26 patients (46%) achieved a good clinical response and 11 (20%) an ASASBIO response. These results at 24 weeks were 19 (33%) and 13 (23%) respectively. All individual clinical variables improved significantly after 4 weeks of treatment. CRP serum levels decreased after 4 weeks but reached no statistical significance, although 30% of patients showed a normalisation of CRP. CONCLUSIONS: Etoricoxib provided a clear clinical improvement in around a third of patients with axial AS refractory to traditional NSAIDs. Special care should be required when deciding to start anti-TNF-α therapy; it seems reasonable to keep in mind these results of etoricoxib treatment.

Anti-TNF-α therapy in patients with refractory uveitis due to Behçet's disease: a 1-year follow-up study of 124 patients.

OBJECTIVE: The aim of this study was to assess the efficacy of anti-TNF-α therapy in refractory uveitis due to Behçet's disease (BD). METHODS: We performed a multicentre study of 124 patients with BD uveitis refractory to conventional treatment including high-dose corticosteroids and at least one standard immunosuppressive agent. Patients were treated for at least 12 months with infliximab (IFX) (3-5 mg/kg at 0, 2 and 6 weeks and then every 4-8 weeks) or adalimumab (ADA) (usually 40 mg every 2 weeks). The main outcome measures were degree of anterior and posterior chamber inflammation, visual acuity, macular thickness and immunosuppression load. RESULTS: Sixty-eight men and 56 women (221 affected eyes) were studied. The mean age was 38.6 years (s.d. 10.4). HLA-B51 was positive in 66.1% of patients and uveitis was bilateral in 78.2%. IFX was the first biologic agent in 77 cases (62%) and ADA was first in 47 (38%). In most cases anti-TNF-α drugs were used in combination with conventional immunosuppressive drugs. At the onset of anti-TNF-α therapy, anterior chamber and vitreous inflammation was observed in 57% and 64.4% of patients, respectively. In both conditions the damage decreased significantly after 1 year. At baseline, 50 patients (80 eyes) had macular thickening [optical coherence tomography (OCT) >250 µm] and 35 (49 eyes) had cystoid macular oedema (OCT>300 µm) that improved from 420 µm (s.d. 119.5) at baseline to 271 µm (s.d. 45.6) at month 12 (P < 0.01). The best-corrected visual acuity and the suppression load also showed significant improvement. After 1 year of follow-up, 67.7% of patients were inactive. Biologic therapy was well tolerated in most cases. CONCLUSION: Anti-TNF-α therapy is effective and relatively safe in refractory BD uveitis.

Standards of care for patients with spondyloarthritis.

To define and give priory to standards of care in patients with spondyloarthritis (SpA). A systematic literature review on SpA standards of care and a specific search in relevant and related sources was performed. An expert panel was established who developed the standards of care and graded their priority (high, mild, low, or no priority) following qualitative methodology and Delphi process. An electronic survey was sent to a representative sample of 167 rheumatologists all around the country, who also gave priority to the standards of care (same scale). A descriptive analysis is presented. The systematic literature review retrieved no article specifically related to SpA patients. A total of 38 standards of care were obtained-12 related to structure, 20 to process, and 6 to result. Access to care, treatment, and safety standards of care were given a high priority by most of rheumatologists. Standards not directly connected to daily practice were not given such priority, as standards which included a time framework. The standards generated for the performance evaluation (including patient and professionals satisfaction) were not considered especially important in general. This set of standards of care should help improve the quality of care in SpA patients.

Toxicity outcome in patients treated with modulated arc radiotherapy for localized prostate cancer.

AIM: This study evaluates the acute toxicity outcome in patients treated with RapidArc for localized prostate cancer. BACKGROUND: Modern technologies allow the delivery of high doses to the prostate while lowering the dose to the neighbouring organs at risk. Whether this dosimetric advantage translates into clinical benefit is not well known. MATERIALS AND METHODS: Between December 2009 and May 2012, 45 patients with primary prostate adenocarcinoma were treated using RapidArc. All patients received 1.8 Gy per fraction, the median dose to the prostate gland, seminal vesicles, pelvic lymph nodes and surgical bed was 80 Gy (range, 77.4-81 Gy), 50.4 Gy, 50.4 Gy and 77.4 Gy (range, 75.6-79.2 Gy), respectively. RESULTS: The time between the last session and the last treatment follow up was a median of 10 months (range, 3-24 months). The incidence of grade 3 acute gastrointestinal (GI) and genitourinary (GU) toxicity was 2.2% and 15.5%, respectively. Grade 2 acute GI and GU toxicity occurred in 30% and 27% of patients, respectively. No grade 4 acute GI and GU toxicity were observed. Older patients (>median) or patients with V60 higher than 35% had significantly higher rates of grade ≥2 acute GI toxicity compared with the younger ones. CONCLUSIONS: RapidArc in the treatment of localized prostate cancer is tolerated well with no Grade >3 GI and GU toxicities. Older patients or patients with higher V60 had significantly higher rates of grade ≥2 acute GI toxicity. Further research is necessary to assess definitive late toxicity and tumour control outcome.

Scoring with the Berlin MRI method for assessment of spinal inflammatory activity in patients with ankylosing spondylitis: a calibration exercise among rheumatologists.

OBJECTIVES: To test the reliability of the Berlin MRI scoring method and the effect of a calibration exercise on the score's reliability among untrained readers in MRI examinations of patients with established ankylosing spondylitis (AS). METHODS: Eleven rheumatologists read blinded images of 20 AS patients before and after a two-day workshop on the Berlin MRI scoring method. Reliability (intra- and inter-reader) and concordance with the expert (all measured by intraclass correlation coefficient (ICC)) were compared before and after 2 weeks of the training. Feasibility in terms of time and difficulty was also measured. RESULTS: The mean Berlin score increased from (mean ± standard deviation) 5.04 ± 6.41 before to 6.40±7.08 after the calibration exercise (p<0.01). Inter-reader ICC decreased from 0.83 (95% CI: 0.75-0.93) to 0.78 (95% CI: 0.66-0.90), and intra-reader ICC from 0.89 (95% CI: 0.84-0.94) to 0.87 (95% CI: 0.82-0.92). Agreement with an experienced reader improved after the calibration exercise, with ICC = 0.59 (95% CI 0.45-0.76) before vs. ICC = 0.65 (95% CI 0.50-0.80) after training. CONCLUSIONS: The Berlin method is a reliable scoring method for assessment of spinal inflammatory activity by using MRI in patients with AS, even in the hands of inexperienced readers. A calibration exercise can improve feasibility and sensitivity of the scoring method.

Oxford phase 3 unicondylar knee arthroplasty through a minimally invasive approach: long-term results.

PURPOSE: Surgical treatment options for medial compartment osteoarthritis of the knee include high tibial osteotomy, total knee arthroplasty or unicompartmental knee arthroplasty (UKA), depending on the patient's age, level of physical activity and the degree of deformity. METHODS: In this study, we evaluated the long-term results of patients who underwent the Oxford cemented meniscal-bearing unicondylar knee prosthesis through a minimally invasive approach including a clinical, functional and radiographic assessment. RESULTS: Favourable clinical and radiological outcomes were registered overall at ten years after surgery. Overall results of UKA according to the American Knee Society (AKS) using Insall's criteria showed an excellent or good outcome for 492 knees (96.28 %), fair for 11 (2.15 %) and poor for eight (1.57 %) in the post-operative long term. CONCLUSIONS: We believe that with appropriate surgical technique, patient selection, prosthetic design and specific training, surgeons should achieve good outcomes with the added advantages of a minimally invasive approach. High volume for this technique is important in our opinion.

A Hybrid Online Off-Policy Reinforcement Learning Agent Framework Supported by Transformers.

Reinforcement learning (RL) is a powerful technique that allows agents to learn optimal decision-making policies through interactions with an environment. However, traditional RL algorithms suffer from several limitations such as the need for large amounts of data and long-term credit assignment, i.e. the problem of determining which actions actually produce a certain reward. Recently, Transformers have shown their capacity to address these constraints in this area of learning in an offline setting. This paper proposes a framework that uses Transformers to enhance the training of online off-policy RL agents and address the challenges described above through self-attention. The proposal introduces a hybrid agent with a mixed policy that combines an online off-policy agent with an offline Transformer agent using the Decision Transformer architecture. By sequentially exchanging the experience replay buffer between the agents, the agent's learning training efficiency is improved in the first iterations and so is the training of Transformer-based RL agents in situations with limited data availability or unknown environments.

Early carbon mobilization and radicle protrusion in maize germination.

Considerable amounts of information is available on the complex carbohydrates that are mobilized and utilized by the seed to support early seedling development. These events occur after radicle has protruded from the seed. However, scarce information is available on the role of the endogenous soluble carbohydrates from the embryo in the first hours of germination. The present work analysed how the soluble carbohydrate reserves in isolated maize embryos are mobilized during 6-24 h of water imbibition, an interval that exclusively embraces the first two phases of the germination process. It was found that sucrose constitutes a very significant reserve in the scutellum and that it is efficiently consumed during the time in which the adjacent embryo axis is engaged in an active metabolism. Sucrose transporter was immunolocalized in the scutellum and in vascular elements. In parallel, a cell-wall invertase activity, which hydrolyses sucrose, developed in the embryo axis, which favoured higher glucose uptake. Sucrose and hexose transporters were active in the embryo tissues, together with the plasma membrane H(+)-ATPase, which was localized in all embryo regions involved in both nutrient transport and active cell elongation to support radicle extension. It is proposed that, during the initial maize germination phases, a net flow of sucrose takes place from the scutellum towards the embryo axis and regions that undergo elongation. During radicle extension, sucrose and hexose transporters, as well as H(+)-ATPase, become the fundamental proteins that orchestrate the transport of nutrients required for successful germination.

Petroleum-influenced beach sediments of the Campeche Bank, Mexico: diversity and bacterial community structure assessment.

The bacterial diversity and community structure were surveyed in intertidal petroleum-influenced sediments of ≈ 100 km of a beach, in the southern Gulf of Mexico. The beach was divided in twenty sampling sites according to high, moderate and low petroleum influence. Densities of cultured heterotrophic (HAB) and hydrocarbon degrading bacteria (HDB) were highly variable in sediments, with little morphological assortment in colonies. PCR-RISA banding patterns differentiated distinct communities along the beach, and the bacterial diversity changed inversely to the degree of petroleum hydrocarbon influence: the higher TPH concentration, the lower genotype diversity. Seven DNA sequences (Genbank EF191394 -EF191396 and EF191398 -EF191401) were affiliated to uncultured members of Gemmatimonas, Acidobacterium, Desulfobacteraceae, Rubrobacterales, Actinobacterium and the Fibrobacteres/Acidobacteria group; all the above taxa are known for having members with active roles in biogeochemical transformations. The remaining sequences (EF191388 - EF191393 and EF191397) affiliated to Pseudoalteromonas, and to oil-degrading genera such as Pseudomonas, Vibrio and Marinobacter, being the last one an obligate oil-degrading bacterium. An exchange of bacteria between the beach and the oil seep environment, and the potential cleaning-up role of bacteria at the southern Gulf of Mexico are discussed.

Real-World Effectiveness and Treatment Retention of Secukinumab in Patients with Psoriatic Arthritis and Axial Spondyloarthritis: A Descriptive Observational Analysis of the Spanish BIOBADASER Registry.

Rheumatic diseases are extensively managed with biological disease-modifying antirheumatic drugs (bDMARDs), but a notable proportion of patients withdraw in the long term because of lack of effectiveness, adverse events, or the patient's decision. The present real-world analysis showed the effectiveness, retention, and safety data collected in the Spanish BIOBADASER registry for patients with psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA, including ankylosing spondylitis (AS) and non-radiographic axSpA) treated with secukinumab, a human antibody against interleukin-17A (IL-17A), for more than 12 months. Six hundred and thirty-nine patients were analysed (350, 262, and 27 PsA, AS, and nr-axSpA patients, respectively). The results showed an improvement in the disease activity after 1 year of treatment, in terms of decreases of the mean Disease Activity Score 28 using C-reactive protein (DAS28-CRP), the mean Disease Activity Psoriatic Arthritis (DAPSA) score, swollen joint counts (SJC), and tender joint counts (TJC) in PsA patients and decreases in the mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the mean Ankylosing Spondylitis Disease Activity Score (ASDAS) in axSpA patients. This improvement was maintained or increased after 2 and 3 years of treatment, indicating that secukinumab is effective in both naïve and non-responder patients. Retention rates were higher when secukinumab was used as the first-line biological treatment, although they were also adequate in the second and third lines of treatment. Collected safety data were consistent with previous reports.

High-dose etanercept in ankylosing spondylitis: results of a 12-week randomized, double blind, controlled multicentre study (LOADET study).

OBJECTIVES: Etanercept 50 mg a week is approved in the treatment of AS. Increasing the etanercept dose to 100 mg/week improves efficacy in cutaneous psoriasis, a clinical manifestation related to the spondylarthritis family, while maintaining its safety profile. The purpose of this study was to evaluate the efficacy and safety of etanercept 100 vs 50 mg/week in patients with AS. METHODS: Adult patients with AS were randomized to receive etanercept 50 mg twice a week (biw), or etanercept 50 mg once a week (qw) for 12 weeks. The primary efficacy endpoint was Ankylosing Spondylitis Assessment Study (ASAS20) response at Week 12; secondary endpoints included ASAS40, ASAS50, ASAS70 and ASAS5/6 responses, partial remission and quality of life. Safety was assessed until 15 days after the last visit. RESULTS: A total of 108 patients were randomly selected and treated, 54 in each arm. At 12 weeks, ASAS20 response was achieved by 34 (71%) out of 48 patients of the etanercept 50 mg biw group and by 37 (76%) out of 49 patients of the etanercept 50 mg qw group (not statistically significant differences). Other efficacy variables improved significantly over time, but not between treatment groups. Fifty-six patients experienced at least one adverse event (generally, infections and infestations, gastrointestinal disorders and injection site reactions), most of them mild or moderate. CONCLUSIONS: High-dose (100 mg/week) etanercept in the treatment of AS for 12 weeks is as safe as the standard dose (50 mg/week). However, it does not significantly increase its efficacy. Trial Registration. Clinicaltrials.gov, http://clinicaltrials.gov/, NCT00873730.

Encystment of Azotobacter nigricans grown diazotrophically on kerosene as sole carbon source.

Encystment of Azotobacter nigricans was induced by its diazotrophic cultivation on kerosene. Its growth and nitrogenase activity were affected by kerosene in comparison to cultures grown on sucrose. Electron microscopy of vegetative cells showed that when nitrogenase activity was higher and the poly-beta-hydroxybutyrate granules were not present to a significant extent, peripheral bodies were abundant. After 8 days of culture on kerosene, the presence of cysts with intracellular bunches of poly-beta-hydroxybutyrate granules was observed. Germination of cysts bears germinating multicelled yet unbroken capsule cysts with up to three cells inside. This is the first report of encystment induction of Azotobacter species grown on kerosene.

Biomass and lipid production from Chlorella vulgaris UTEX 26 cultivated in 2 m3 raceway ponds under semicontinuous mode during the spring season.

A Chlorella vulgaris UTEX 26 semicontinuous culture was implemented in 2000 L raceways with M medium during spring season at greenhouse conditions. Areal biomass productivities between 20 and 26 g m-2 d-1 were reached on the third day. The maximal areal lipid productivity obtained was 6.1 g m-2 d-1 and an increment in the saturated fatty acids (SFA) proportion (C14-C18) was favored in comparison with the fatty acids obtained with M medium in photobioreactors of 1 L and photoperiod light:darkness 12:12 h. After the eighth day of the culture or biomass concentrations above 0.25 g L-1, the microalgal cultures were prone to contamination by ciliates and amoebae, due to the sugars excreted by C. vulgaris UTEX 26. The periodical addition of NH4HCO3 to the microalgal culture maintained the ammonium concentration between 25 and 50 mg L-1, which contributed to diminish the contamination risks by protozoa.