Bovine bile as a bio-surfactant pre-treatment option for anaerobic digestion of high-fat cattle slaughterhouse waste

Bovine bile was assessed as a novel bio-surfactant pre-treatment to enhance anaerobic digestion of lipid-rich dissolved air flotation (DAF) sludge using biochemical methane potential (BMP) tests. Bile was dosed at arbitrary concentrations from 0.2–6 g/L. At 0.6 g bile/L, methane yield increased by 7.08%. Doses above 2 g bile/L produced negative impacts on SMP, kinetics and digestion profile. At 6 g/L bile produced a 6% decrease in specific methane production and up to 79% additional inhibitory duration, delayed time of peak methane production by up to 74%, and slowed total digestion time by up to 65%. Reaction kinetics declined linearly with respect to bile addition, reaching half the control value at 6 g/L bile concentration. Subsequent anaerobic toxicity assays between 1 and 6 g bile/L revealed that bile has an inhibitory effect under BMP testing at these higher doses. The economic viability of using bile as a bio-surfactant was assessed. In comparison to the current use of bile as a sale product to pharmaceutical companies, the addition of 0.2 g bile/L to existing slaughterhouse waste streams could increase the value of bile to 220% of its current sale value. The promising results of bile dosed at 0.6 g/L under BMP testing warrant further investigation into long-term impact of bile pre-treatments of high-fat slaughterhouse wastewater in semi-continuous digestion experiments

Flood dispersal and deposition by near-bed gravitational sediment flows and oceanographic transport : a numerical modeling study of the Eel River shelf, northern California

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 110 (2005): C09025, doi:10.1029/2004JC002727.A large flood of the Eel River, northern California, created a thick sediment deposit between water depths of 50 and 70 m in January 1997. The freshwater plume, however, confined sediment delivery to water depths shallower than 30 m. Mechanisms proposed to explain the apparent cross-shelf transport include dispersal by oceanographic currents, resuspension by energetic waves, and gravitationally forced transport of a thin layer of fluidized mud. Field observations indicate that these processes were all active but cannot determine their relative significance or whether these mechanisms alone explain the location, size, and timing of deposition. Approximately 30% of the sediment delivered by the Eel River is accounted for in the midshelf mud bed and inner shelf, but the fate of the remaining 70% is uncertain. A three-dimensional, hydrodynamic model was used to examine potential mechanisms of sediment transport on the Eel River shelf. The model includes suspended sediment transport and was modified to account for a thin, near-bed layer of fluidized mud. It was used to simulate flood dispersal on the Eel River shelf, to compare the relative importance of transport within the near-bed fluid mud layer to suspended sediment transport, and to evaluate sediment budgets for floods. Settling properties of fine-grained sediment, both within the flood plume and the fluid mud layer, critically impact depositional patterns. To a lesser degree, wind-driven ocean currents influence the volume of sediment that escapes the shelf, and wave magnitude affects the cross-shelf location of flood deposits. Though dilute suspension accounts for a large fraction of total flux, cross-shelf transport by gravitational forcing appears necessary to produce a midshelf mud deposit similar in volume, location, and timing to those seen offshore of the Eel River.The Office of Naval Research’s Coastal Geoscience Program supported this through program N0014-01-1-008

Multi-neuronal refractory period adapts centrally generated behaviour to reward

Oscillating neuronal circuits, known as central pattern generators (CPGs), are responsible for generating rhythmic behaviours such as walking, breathing and chewing. The CPG model alone however does not account for the ability of animals to adapt their future behaviour to changes in the sensory environment that signal reward. Here, using multi-electrode array (MEA) recording in an established experimental model of centrally generated rhythmic behaviour we show that the feeding CPG of Lymnaea stagnalis is itself associated with another, and hitherto unidentified, oscillating neuronal population. This extra-CPG oscillator is characterised by high population-wide activity alternating with population-wide quiescence. During the quiescent periods the CPG is refractory to activation by food-associated stimuli. Furthermore, the duration of the refractory period predicts the timing of the next activation of the CPG, which may be minutes into the future. Rewarding food stimuli and dopamine accelerate the frequency of the extra-CPG oscillator and reduce the duration of its quiescent periods. These findings indicate that dopamine adapts future feeding behaviour to the availability of food by significantly reducing the refractory period of the brain's feeding circuitry

Extreme star formation events in quasar hosts over 0.5<z<4{\bf0.5<\textit{z}<4}

We explore the relationship between active galactic nuclei and star formation in a sample of 513 optically luminous type 1 quasars up to redshifts of $\sim$4 hosting extremely high star formation rates (SFRs). The quasars are selected to be individually detected by the \textit{Herschel} SPIRE instrument at $>$3$\sigma$ at 250 $\mu$m, leading to typical SFRs of order of 1000 M$_{\odot}$yr$^{-1}$. We find the average SFRs to increase by almost a factor 10 from $z\sim0.5$ to $z\sim3$, mirroring the rise in the comoving SFR density over the same epoch. However, we find that the SFRs remain approximately constant with increasing accretion luminosity for accretion luminosities above 10$^{12}$ L$_{\odot}$. We also find that the SFRs do not correlate with black hole mass. Both of these results are most plausibly explained by the existence of a self-regulation process by the starburst at high SFRs, which controls SFRs on time-scales comparable to or shorter than the AGN or starburst duty cycles. We additionally find that SFRs do not depend on Eddington ratio at any redshift, consistent with no relation between SFR and black hole growth rate per unit black hole mass. Finally, we find that high-ionisation broad absorption line (HiBAL) quasars have indistinguishable far-infrared properties to those of classical quasars, consistent with HiBAL quasars being normal quasars observed along a particular line of sight, with the outflows in HiBAL quasars not having any measurable effect on the star formation in their hosts.Comment: 12 pages, 6 figure

Degradation and forgone removals increase the carbon impact of intact forest loss by 626%

Intact tropical forests, free from substantial anthropogenic influence, store and sequester large amounts of atmospheric carbon but are currently neglected in international climate policy. We show that between 2000 and 2013, direct clearance of intact tropical forest areas accounted for 3.2% of gross carbon emissions from all deforestation across the pantropics. However, full carbon accounting requires the consideration of forgone carbon sequestration, selective logging, edge effects, and defaunation. When these factors were considered, the net carbon impact resulting from intact tropical forest loss between 2000 and 2013 increased by a factor of 6 (626%), from 0.34 (0.37 to 0.21) to 2.12 (2.85 to 1.00) petagrams of carbon (equivalent to approximately 2 years of global land use change emissions). The climate mitigation value of conserving the 549 million ha of tropical forest that remains intact is therefore significant but will soon dwindle if their rate of loss continues to accelerate

Effect of Lowest Instrumented Vertebra on Trunk Mobility in Patients With Adolescent Idiopathic Scoliosis Undergoing a Posterior Spinal Fusion

Study Design Prospective. Objectives The goal of this study was to evaluate the effect of posterior spinal fusion surgery terminating at different lowest instrumented vertebrae (LIV) on trunk mobility in individuals with adolescent idiopathic scoliosis (AIS). Summary of Background Data Posterior spinal fusion with instrumentation is the standard surgical technique employed in AIS for correcting spine deformities with Cobb angles exceeding 50°. Surgical correction of curve deformity reduces trunk mobility and range of motion. However, conflicting findings from previous studies investigating the impact of different LIV levels on the reduction in trunk mobility after surgery have been reported. Methods The study was designed as a prospective study with 47 patients (7 males and 40 females) with AIS who underwent posterior spinal fusion. Patients were classified into 5 groups based on their surgical LIV level (ie, T12, L1, L2, L3, and L4). Trunk flexion-extension (sagittal plane), lateral bending (coronal plane), and axial rotation (transverse plane) kinematics were assessed during preoperative, 1 year postoperative, and 2 years postoperative evaluation visits. Results There were postoperative reductions of 41%, 51%, and 59% in trunk range of motion in the sagittal, coronal, and transverse planes, respectively (p \u3c .0001). A trend toward greater postoperative reductions in peak forward flexion at more distal LIVs was observed (p = .04). Conclusions Fusion reduces trunk mobility in the sagittal, coronal, and transverse planes. More distal LIV fusions limit peak forward flexion to a greater extent which is considered clinically significant. After fusion, the reductions seen in axial rotation, lateral bending, and backward extension do not differ significantly at more distal LIVs

Process optimisation of anaerobic digestion treating high-strength wastewater in the Australian red meat processing industry

This work represents and reviews a compilation of investigations into improving anaerobic digestion performance of high-strength wastewater in the Australian Red Meat Processing industry. The industry produces significant quantities of organic-rich wastewater which requires treatment prior to release to the environment. Anaerobic lagoons are a cost-effective method of waste treatment where land availability is not an issue; however, the high fat load in the wastewater can negatively impact the anaerobic lagoon system and result in compromised anaerobic digestion performance. This paper will discuss the importance of upstream primary pre-treatment and review a series of investigations focused on optimising digester performance and improving fat biodegradability. These studies include: 1. the effect of temperature and mixing; 2. the influence of feedstock trace element composition and supplementation, and; 3. the potential benefit from pre-treatments such as chemical, thermobaric, thermochemical and bio-surfactant. This paper discusses the implications of these findings for covered anaerobic lagoon operation and provides recommendations to promote optimum digester performance and future opportunities in adopting alternate anaerobic digestion technology options. Finally, the paper provides recent trends toward the use of other waste streams for co-digestion and discusses this in terms of digester optimization and technology options

Survival following Treatment of Aortoesophageal Fistula with Dual Esophageal and Aortic Intervention

Aortoesophageal fistulas are a rare but commonly fatal complication of esophageal cancer. Reports of successfully managed cases are few, with high mortality and morbidity usually resulting from failure to control the initial massive haemodynamic insult. We report the case of a 47-year-old Caucasian man with recently diagnosed advanced esophageal cancer who suffered an episode of massive haematemesis. Emergency gastroscopy revealed an arterial bleeding point in the proximal esophagus. A self-expanding metal esophageal stent was placed to achieve initial partial haemostasis. CT angiography confirmed an aortoesophageal fistula. An endoluminal stent device was thus inserted within the thoracic aorta stabilising the bleeding point. The patient subsequently made an uneventful recovery and was discharged on long-term antibiotics for palliative care. He survived for 2 months at home before dying of disseminated malignancy. The successful use of esophageal stenting as a means of achieving haemostasis, allowing time for endovascular intervention, is as yet a relatively unexplored area of management of this rare condition

Cryogenic mechanical loss of a single-crystalline GaP coating layer for precision measurement applications

The first direct observations of gravitational waves have been made by the Advanced LIGO detectors. However, the quest to improve the sensitivities of these detectors remains, and epitaxially grown single-crystal coatings show considerable promise as alternatives to the ion-beam sputtered amorphous mirror coatings typically used in these detectors and other such precision optical measurements. The mechanical loss of a 1 μm thick single-crystalline gallium phosphide (GaP) coating, incorporating a buffer layer region necessary for the growth of high quality epitaxial coatings, has been investigated over a broad range of frequencies and with fine temperature resolution. It is shown that at 20 K the mechanical loss of GaP is a factor of 40 less than an undoped tantala film heat-treated to 600 °C and is comparable to the loss of a multilayer GaP/AlGaP coating. This is shown to translate into possible reductions in coating thermal noise of a factor of 2 at 120 K and 5 at 20 K over the current best IBS coatings (alternating stacks of silica and titania-doped tantala). There is also evidence of a thermally activated dissipation process between 50 and 70 K

Negotiating the Maze: Case based, Collaborative Distance Learning in Dentistry

The module was developed as an elective to give motivated senior dental students an opportunity to expand their horizons in planning oral rehabilitation. It comprised one tutor and 12 students, from five universities world-wide, communicating on the World Wide Web (WWW), to develop oral rehabilitation plans for simulated patients. Trigger material came from one of two Case Profiles and consisted of diagnostic casts and details of the clinical and radiographic examination in WWW/CD-ROM form. No background material was supplied as to the "patient's" age, sex, history or main concern(s). Students worked in groups of three, each student from a different location. Individual students were given a role within the group: "Patient", who developed a "personal background" belonging to the trigger examination material, "Academic" who identified state-of-the-art treatment options available for the dental treatment needs identified by the group and "General Practitioner" who tailored these options to the "patient's" needs and wants. Student feedback focused on their perception of their experience with the program in response to a questionnaire comprising 11 structured and four "open" questions. All students felt that the program increased their confidence in planning oral rehabilitation. Ten students felt that the "best thing about the program" was the interaction with students from other universities and the exposure to different philosophies from the different schools. Eight students mentioned their increased awareness of the importance of patient input into holistic planning. Under the heading "What was the worst thing", students cited some technical hitches and the snowball effect of two sluggish students who were not identified early enough and thus impacted negatively on the working of their groups. Student feedback showed that the module succeeded in its aims but needed modification to improve the logistics of working with an extended campu