Assessing Effects and interactions among key variables affecting the growth of mixotrophic microalgae: pH, inoculum volume, and growth medium composition.

A 2(3) + 3 full factorial experimental design was used to evaluate growth rate and biomass productivity of four selected, high-biomass-yielding microalgae species,namely, Chlorella vulgaris (CV), Scenedesmus acutus (SA), Chlamydomonas reinhardtii (CR), and Chlamydomonas debaryana (CD), in mixtures of growth medium (MWC) and wastewater at different proportions (from 20 to 50% of MWC) and at different pH (from 7 to 9). Multilinear regression analysis of the biomass productivity data showed that for SA and CD the biomass productivity was independent of the proportion of medium (MWC), while the growth of CV and CR slowed down in mixtures with high proportions of wastewater. However, the biomass productivity of SA was dependent on pH, while the growth of the other microalgae was independent of pH (7-9). When evaluating the influence of pH and proportion of medium, CD appeared most robust among the algae species, despite its lower biomass productivity. All the four species reduced 80-90% of the nitrate [Formula: see text] and 60-70% of the ammonia [Formula: see text] initially present in the wastewater:medium mixture, although the extent of the reduction was dependent on the initial [Formula: see text] ratio. Both SA and CV reduced ∼20-25% of the chemical oxygen demand (COD) contained in the wastewater. This study shows the remarkable influence of certain variables that are often ignored in the search for optimal conditions of microalgal growth and also reveals the importance of considering interactions among growth variables in potential applications at large scale, particularly in the field of bioremediation.

Admixture estimates for the population of Havana City.

BACKGROUND: The Cuban population is essentially a result of the admixture between Spanish, West African and, to a lesser degree, Amerindian tribes that inhabited the island. AIM: The study analysed the genetic structure of the three principal ethnic groups from Havana City, and the contribution of parental populations to its genetic pool. SUBJECTS AND METHODS: According to genealogical information and anthropological traits, 206 subjects were classified as Mulatto, of Spanish decent or of African descent. Seventeen Ancestry Informative Markers, with high difference in frequency between parental populations, were selected to estimate individual and group admixture proportions. The statistical analyses were performed using the ADMIX, ADMIX95 and STRUCTURE 2.1 packages. RESULTS: The results demonstrate a high level of European and African admixture in Mulattos (57-59% European; 41-43% West African). The European contribution was higher in those of Spanish descent (85%) while in those of African descent, the West African contribution ranged between 74% and 76%. Genetic structure was only detected in Mulattos and those of African descent. An Amerindian contribution was not detectable in the studied sample. CONCLUSION: Our findings indicate the existence of admixture and genetic structure in the population of Havana City. This study represents one of the first steps towards understanding Cuban population admixture in order to produce successful experimental designs for admixture mapping.

Brain death after severe traumatic brain injury: the role of systemic secondary brain insults.

Secondary brain insults predominantly due to hypotension are frequent among patients with fatal traumatic brain injury. We assessed the correlation between different systemic secondary brain insults and brain death in 404 patients admitted to our intensive care unit (ICU) after severe traumatic brain injury. We collated data on hypoxemia and hypotension prior to as well as the occurrence of hypoxemia, hypotension, shock, anemia, hyperglycemia, and hyperthermia within the first 24 hours after ICU admission. We also considered both the presence of extracranial injuries and the category of traumatic brain injury using computerized tomography. The 59 patients (14.6%) who developed brain death, were significantly older than patients without a fatal neurological outcome (46.1 +/- 22 vs 29.5 +/- 14.9 years; P < .0001). Intracranial mass lesions, whether surgically evacuated were more frequent among brain-dead patients. The systemic secondary brain insults significantly associated with brain death were hypoxemia, hypotension, shock, anemia, and hyperglycemia within the first 24 hours after ICU admission. After multivariate analysis, the factors that independently predicted brain death were the occurrence of shock (odds ratio [OR], 6.74; 95% confidence interval [CI], 2.85-15.84; P = .001) and older age (OR, 1.05; 95% CI, 1.03-1.07; P = .003). In conclusion, early shock seems to be the major systemic secondary brain insult associated with brain death in patients with severe traumatic brain injury. Prevention of or correction of shock might help to either decrease the occurrence of a fatal neurological outcome or in brain-dead patients to preserve organs in better condition for procurement.

[Assessment of hypothalamo-pituitary axis in early phase of severe cranioencephalic brain injury]. / Valoración del eje hipotálamo-hipofisario en la fase precoz del traumatismo craneoencefálico grave.

OBJECTIVE: To assess early pituitary function in a sequential cohort of critical care patients after severe traumatic brain injury (TBI). DESIGN: This was a prospective observational study. The pituitary function was always tested on the third day after TBI. SETTING: Neurocritical intensive care unit (ICU) in a University hospital. PATIENTS: A total of 136 adult patients with severe TBI (range, 16-65 years) enrolled over a 2 year and 9 month period having a stay in the ICU treated than 48 hours. INTERVENTION: None. MEASUREMENTS AND DATA COLLECTED: The following data were recorded within the first 72 hours after injury: demographic variables, injury severity, neuromonitoring data, systemic secondary brain insults, use of vasoactive drugs and type of TBI according to the computerized tomography (CT) scan findings. Pituitary function was evaluated by measurement of both the pituitary and target organ hormones, with the exception of the somatotrophic function, which was assessed by measurement of basal serum values of insulin-like growth factor-I (IGF-I). RESULTS: Pituitary dysfunction was observed in 101 patients (74.2%). Seventy-nine patients (58%) had impairment of only one pituitary axis, the axes being affected as follows: gonadotropic 63.7% (87 patients), thyrotropic 8.8% (12 patients) and corticotropic 0.7% (1 patient). Low IGF-1 plasmatic levels in accordance to the patient's age were observed in 90 patients (66.7%). However, only 26 of them had a value below 90 ng/ml. CONCLUSIONS: Our data show that pituitary dysfunction occurs early and with high frequency after severe TBI, but the real significance of these findings still needs to be elucidated.

A high-throughput AFLP-based method for constructing integrated genetic and physical maps: progress toward a sorghum genome map.

Sorghum is an important target for plant genomic mapping because of its adaptation to harsh environments, diverse germplasm collection, and value for comparing the genomes of grass species such as corn and rice. The construction of an integrated genetic and physical map of the sorghum genome (750 Mbp) is a primary goal of our sorghum genome project. To help accomplish this task, we have developed a new high-throughput PCR-based method for building BAC contigs and locating BAC clones on the sorghum genetic map. This task involved pooling 24,576 sorghum BAC clones ( approximately 4x genome equivalents) in six different matrices to create 184 pools of BAC DNA. DNA fragments from each pool were amplified using amplified fragment length polymorphism (AFLP) technology, resolved on a LI-COR dual-dye DNA sequencing system, and analyzed using Bionumerics software. On average, each set of AFLP primers amplified 28 single-copy DNA markers that were useful for identifying overlapping BAC clones. Data from 32 different AFLP primer combinations identified approximately 2400 BACs and ordered approximately 700 BAC contigs. Analysis of a sorghum RIL mapping population using the same primer pairs located approximately 200 of the BAC contigs on the sorghum genetic map. Restriction endonuclease fingerprinting of the entire collection of sorghum BAC clones was applied to test and extend the contigs constructed using this PCR-based methodology. Analysis of the fingerprint data allowed for the identification of 3366 contigs each containing an average of 5 BACs. BACs in approximately 65% of the contigs aligned by AFLP analysis had sufficient overlap to be confirmed by DNA fingerprint analysis. In addition, 30% of the overlapping BACs aligned by AFLP analysis provided information for merging contigs and singletons that could not be joined using fingerprint data alone. Thus, the combination of fingerprinting and AFLP-based contig assembly and mapping provides a reliable, high-throughput method for building an integrated genetic and physical map of the sorghum genome.