Acoustic measurement of the Deepwater Horizon Macondo well flow rate

On May 31, 2010, a direct acoustic measurement method was used to quantify fluid leakage rate from the Deepwater Horizon Macondo well prior to removal of its broken riser. This method utilized an acoustic imaging sonar and acoustic Doppler sonar operating onboard a remotely operated vehicle for noncontact measurement of flow cross-section and velocity from the well’s two leak sites. Over 2,500 sonar cross-sections and over 85,000 Doppler velocity measurements were recorded during the acquisition process. These data were then applied to turbulent jet and plume flow models to account for entrained water and calculate a combined hydrocarbon flow rate from the two leak sites at seafloor conditions. Based on the chemical composition of end-member samples collected from within the well, this bulk volumetric rate was then normalized to account for contributions from gases and condensates at initial leak source conditions. Results from this investigation indicate that on May 31, 2010, the well’s oil flow rate was approximately 0.10 ± 0.017 m³ s^-1 at seafloor conditions, or approximately 85 ± 15 kg s^-1 (7.4 ± 1.3 Gg d^-1), equivalent to approximately 57,000 ± 9,800 barrels of oil per day at surface conditions. End-member chemical composition indicates that this oil release rate was accompanied by approximately an additional 24 ± 4.2 kg s^-1 (2.1 ± 0.37 Gg d^-1) of natural gas (methane through pentanes), yielding a total hydrocarbon release rate of 110 ± 19 kg s^-1 (9.5 ± 1.6 Gg d^-1).     

Conservation of an immunoglobulin variable-region gene family indicates a specific, noncoding function.

Blot-hybridization and DNA sequence analyses reveal the particular evolutionary conservation of a group of immunoglobulin heavy-chain variable-region (VH) genes in all mammalian species examined. These particular genes are group III genes--the VH7183 family in the mouse and the homologous VH III family in human. This conservation is localized to sequences encoding framework regions 1 and 3 of the antibody variable region and is exerted at the nucleotide level. Because selection acting at the amino acid level alone cannot explain the conservation of these sequences, these sequences must have a noncoding function. The preferential rearrangement of VH7183 and VH III genes, together with the similarity of the conserved sequences to elements implicated in recombination in other systems, suggest that these sequences function to target the series of rearrangements that assemble complete immunoglobulin genes.     

School-Based Predictors of Early Adolescent Depression

Childhood and adolescent depression is associated with negative outcomes in the school environment. Research demonstrates that childhood and adolescent depression often results in poor schoolwork, reduced academic achievement, impairments on cognitive tasks, and acting out behavior patterns. This longitudinal study sought to determine the extent to which affective, social, and academic variables collected in 3rd, 4th, and 5th grades could predict depressive symptoms in 6th grade (early adolescence). A primary objective was to define conceptual sets of school-based predictor variables that would reliably predict depressive symptoms in early adolescence. Results from cross-validated discriminant function analyses indicated the best group of predictors of depression in early adolescence included teacher rated academic competence, social skills, critical events, self-reported loneliness, self-image, and self-concept. The results suggest that early school-based identifiers of depressive symptoms are found prior to early adolescence.     

In vivo investigation of tolerance and antitumor activity of cisplatin-loaded PLGA-mPEG nanoparticles

The tolerance of BALB/c mice to different doses of blank and cisplatin-loaded PLGA-mPEG nanoparticles and the in vivo anticancer activity of these nanoparticles on SCID mice xenografted with colorectal adenocarcinoma HT 29 cells were investigated. Nanoparticles with an average size of 150-160 nm and approximately 2% w/w cisplatin content were prepared by a modified emulsification and solvent evaporation method. Normal BALB/c mice tolerated three weekly intravenous injections of a relatively high dose of blank PLGA-mPEG nanoparticles (500 mg/kg, equivalent to about 10 mg nanoparticles/mouse) and three weekly intravenous injections of a high dose of nanoparticle-entrapped cisplatin (10 mg/kg). Also, histopathology examination indicated that there were no differences in the kidneys or spleens from animals treated with cisplatin-loaded nanoparticles or blank nanoparticles compared to the untreated control group. A moderate granulation of protoplasm of hepatic cells was observed in the livers from mice treated with cisplatin-loaded nanoparticles and blank nanoparticles, however, both the hepatic lobe and the portal hepatis maintained their normal architecture. The cisplatin-loaded PLGA-mPEG nanoparticles appeared to be effective at delaying tumor growth in HT 29 tumor-bearing SCID mice. The group of mice treated with cisplatin-loaded nanoparticles exhibited higher survival rate compared to the free cisplatin group. The results justify further evaluation of the in vivo antitumor efficacy of the PLGA-mPEG/cisplatin nanoparticles.     

A comparison of father–infant interaction between primary and non-primary care giving fathers

Background This study examined the socio‐demographic characteristics and attitudes of primary care giving fathers and non‐primary care giving fathers and the quality of their interaction with their infants. Method Two groups of fathers of 11.9‐month old infants were compared – 25 primary care giving fathers (20 h per week or more of sole infant care) and 75 non‐primary care giving fathers – with regard to socio‐demographic characteristics, attitudinal differences and father–infant interaction during play and mealtimes. The quality of father–child interaction in relation to the total number of hours of primary care provided by fathers was also examined. Results Primary care giving fathers had lower occupational status and earned a smaller proportion of the family income but did not differ in educational level or attitudes compared with non‐primary care giving fathers. There were no differences between the partners of the two groups of fathers on any variables, and their infants did not differ in temperament. Primary care giving fathers and their infants exhibited more positive emotional tone during play than non‐primary care giving fathers, although fathers did not differ in responsivity. There were no differences between the groups during mealtimes. There was a positive association between total number of child care hours provided by all fathers and infant positive emotional tone. Conclusions Primary and non‐primary care giving fathers were similar in many respects, but primary care giving fathers and their infants were happier during play. This suggests a possible link between the involvement of fathers in the care of their children and their children's emotional state. The finding of a trend towards increased paternal happiness with increased hours of child care suggests that there may also be a gain for fathers who are more involved in the care of their infants. Further research is needed to determine whether these differences ultimately have an effect on children's development.     

Parent Support,Peer Support,and Peer Acceptance in Healthy Lifestyle for Asthma Management Among Early Adolescents

PURPOSE. This study aims to investigate the association between social support variables and healthy lifestyle for asthma management among early adolescents (ages 9–14 years). DESIGN AND METHODS. Questionnaires were completed by 86 parent–adolescent dyads. RESULTS. Healthy lifestyle was associated with social support variables. The association with peer acceptance was stronger among adolescents who received less asthma-specific support from peers. Age was negatively associated with healthy lifestyle, but the association was attenuated after adjustment for asthma-specific peer support. PRACTICE IMPLICATIONS. The findings of this study suggest recognizing the developmental change of social support during early adolescence.     

Fallout plume of submerged oil from Deepwater Horizon

The sinking of the Deepwater Horizon in the Gulf of Mexico led to uncontrolled emission of oil to the ocean, with an official government estimate of ∼5.0 million barrels released. Among the pressing uncertainties surrounding this event is the fate of ∼2 million barrels of submerged oil thought to have been trapped in deep-ocean intrusion layers at depths of ∼1,000–1,300 m. Here we use chemical distributions of hydrocarbons in >3,000 sediment samples from 534 locations to describe a footprint of oil deposited on the deep-ocean floor. Using a recalcitrant biomarker of crude oil, 17α(H),21β(H)-hopane (hopane), we have identified a 3,200-km² region around the Macondo Well contaminated by ∼1.8 ± 1.0 × 10⁶ g of excess hopane. Based on spatial, chemical, oceanographic, and mass balance considerations, we calculate that this contamination represents 4–31% of the oil sequestered in the deep ocean. The pattern of contamination points to deep-ocean intrusion layers as the source and is most consistent with dual modes of deposition: a “bathtub ring” formed from an oil-rich layer of water impinging laterally upon the continental slope (at a depth of ∼900–1,300 m) and a higher-flux “fallout plume” where suspended oil particles sank to underlying sediment (at a depth of ∼1,300–1,700 m). We also suggest that a significant quantity of oil was deposited on the ocean floor outside this area but so far has evaded detection because of its heterogeneous spatial distribution.The sinking of the Deepwater Horizon in the Gulf of Mexico led to the discharge of ∼5.0 million barrels of petroleum from the Macondo Well. The discharge occurred at a water depth of ∼1,500 m and gave rise to intrusion layers (1) in the deep ocean that included both water-soluble hydrocarbons in the dissolved phase (2–6) and small particles of water-insoluble hydrocarbons (7–11). These intrusion layers were found primarily at a depth of 1,000–1,300 m and may have hosted the majority of the environmental discharge, including all the natural gas and ∼2 million barrels of liquid oil (12). Although the most abundant of the water-soluble hydrocarbons underwent rapid biodegradation during the spill (4, 6, 8, 9, 13–15), the fate and impacts of the insoluble hydrocarbons in the deep ocean have remained uncertain (16).The intrusion layers that hosted hydrocarbon contamination persisted for 6 mo or more and at distances >300 km from the well, but available evidence suggests that particles of submerged oil were particularly concentrated during the first 6 wk of discharge and within ∼15 km of the well (8, 9, 11). Thus, initial partitioning of hydrocarbon particles to the intrusion layers appears to have given way to transport or removal by undefined deep-ocean processes. Such processes might include sedimentation, buoyant rise toward the sea surface, incorporation into pelagic biota, biodegradation, or interventions at the wellhead. Mechanisms exist that support several of these options (9, 17–20), but uncertainty as to oil’s actual partitioning, the effect of chemical dispersant (21), and the impacts of a changing microbial community (6, 8, 9, 13–15, 17, 22–24) have precluded further understanding of the processes that acted on the oil.In this study we focus on testing the hypothesis that oil particles suspended in the deep intrusion layers were deposited on the sea floor over a broad area. To do so, we use publicly available data generated as part of the ongoing Natural Resource Damage Assessment (NRDA) process (Supporting Information) to assess the spatial distribution of petroleum hydrocarbons in the deep-ocean sediments of the Gulf of Mexico. We focus on the recalcitrant compound 17α(H),21β(H)-hopane (hereafter referred to as “hopane”) as a conserved tracer for crude oil deposition to sediments (25); we treat hopane as a degradation-resistant proxy for Macondo’s liquid-phase oil (26). Analysis of the spatial distribution of hopane allows us to define both a regional background level and a depositional footprint of oil from the Deepwater Horizon event. In combination with other lines of evidence, this analysis leads us to conclude that significant quantities of particulate oil sank from the intrusion layers to rest on the underlying sea floor.     

Reverse restriction fragment length polymorphism (RRFLP): A novel technique for genotyping infectious laryngotracheitis virus (ILTV) live attenuated vaccines

A novel technique, the reverse restriction fragment length polymorphism (RRFLP) assay, was developed as a means of detecting specific informative polymorphic sites in the infectious laryngotracheitis virus (ILTV) genome. During the RRFLP procedure, DNA is digested with restriction enzymes targeting an informative polymorphic site and then used as template in a real-time polymerase chain reaction (PCR) with primers flanking the informative region. The analysis of the ΔC_t values obtained from digested and undigested template DNA provides the genotype of the DNA. In this study, the RRFLP assay was applied as a method to differentiate between the two types of infectious laryngotracheitis virus attenuated live vaccines. Sequence analysis of ILTV vaccines revealed an informative polymorphic site in the 5′-non-coding region of the infected cell protein (ICP4) gene. Unique AvaI and AlwI restriction enzyme sites were identified in the tissue culture origin and chicken embryo origin attenuated vaccines, respectively. These two informative polymorphic sites were used in a RRFLP assay to genotype rapidly and reproducibly ILTV attenuated live vaccines.     

Beneficial effects of a protein free, high carbohydrate meal on rat coping behavior and neurotransmitter levels during heat stress

This study examined effects of a single protein-free (PROT-free), high carbohydrate meal (0% protein, 82% carbohydrate) or control meal (20% protein, 62% carbohydrate) on coping behavior and neurotransmitter levels of male Fischer 344 rats. Meals varying in protein/carbohydrate ratio differentially affect transport of neurotransmitter precursors into the brain and alter neurotransmission. The meals were studied in animals exposed to heat stress and normothermic control animals. Coping behavior was assessed using the Porsolt swim test (N = 39). In other rats, dopamine (DA), epinephrine (EPI), norepinephrine (NE) and serotonin in the striatum were assessed using in vivo microdialysis (N = 35). In control-fed rats, heat stress impaired Porsolt performance in comparison to normothermic controls (p <0.05). The PROT-free, high carbohydrate meal protected animals from adverse effects of stress on coping performance as it reduced the effect of heat stress more than 90%. Significant changes in striatal DA and EPI efflux were observed as a consequence of the nutritional manipulation and heat exposure. It is concluded a single PROT-free, high carbohydrate meal improves ability to cope with heat stress and alters neurotransmission. The neurochemical basis for these effects may be a change in DA efflux, although other mechanisms cannot be ruled out.