Comparison of semi-automatic and automatic data acquisition methods for studying three-dimensional distributions of large neuronal populations and axonal plexuses

Neuroanatomy is in need of high throughput methods for reliably recording the distribution of tissue elements across large brain regions. We compared two methods for recording the spatial distribution of identified neuronal elements such as tracer labelled cell bodies or axonal plexuses. The methods compared were computerized image-combining microscopy (semi-automatic method), which is a user controlled method providing feedback during digitization, and digital camera technology with image analysis software (automatic method). Both methods were applied to biotinylated dextran amine labelled axonal plexuses and FluoroRuby labelled neuronal cell bodies, in the pontine nuclei of the rat. Coordinates were assigned to the labelled elements using both methods. The ensuing distribution patterns were compared, section by section, and in three-dimensional reconstruction. The experienced investigator, using the semi-automatic method, could detect individual axons, fragments of axons, weakly labelled elements, and overlapping cell bodies, better than the automatic system. Nevertheless, both methods detected the overall distribution of the labelled axons and cells investigated. Automatic methods provide opportunities for efficient large-scale data acquisition of labelled neuronal elements.     

The quality of cold-smoked Atlantic salmon (Salmo salar) as affected by salting method, time and temperature

The effects of temperature (4 and 10–12 °C) and time (6, 12 and 24 h) on colorimetric parameters (Commission International de l'Eclairage (CIE) L*a*b*), carotenoid concentration, salt content and yield were investigated in brine (saturated or 50% saturation) and dry salted fillets of cold‐smoked Atlantic salmon (Salmo salar). Lightness (L*), yellowness (b*), hue (H_ab) and chroma (C*) values were lower at 10 than 4 °C (P < 0.01), whereas redness (a*) was unaffected. L* increased (P < 0.05) and a*, b*, H_ab and C* values dropped when salting time was increased (P < 0.001). Astaxanthin concentration of brine‐salted fillets decreased with increasing salting time (P < 0.05), but was unaffected by salting temperature. Increasing salting time affected colour negatively. The salt content of dry salted fillets increased with temperature and salting time. The process yield was unaffected by temperature and decreased with salting time. In conclusion, the cold smoking process is more important for variation in quality parameters than the salting process.     

Performance-based modelling of long-term deterioration to support rehabilitation and investment decisions in drinking water distribution systems

Managing the urban drinking water system in the long term in order to maintain system performance can be challenging due to the difficulty of modelling future deterioration of the networks. This paper establishes a methodology for cohort survival models where historical (empirical) data on decommissioning ages of pipes are used to calibrate survival functions of pipe cohorts according to service level targets. The benefit of the approach is that remaining useful life of pipes, future renewal rates and investment needs can be governed by a required level of service in the network. A case study shows how the methodology can be applied to a cohort of drinking water pipes to create a ‘calibration curve’, which is a survival function calibrated with empirical data.     

Effect of Modified Atmosphere Packaging and Soluble Gas Stabilization on the Shelf Life of Skinless Chicken Breast Fillets

The suitability of soluble gas stabilization (SGS) to dissolve CO₂ into skinless chicken breast fillets before modified atmosphere (MA) packaging (MAP) was investigated. Head space gas composition (%), top web deflation (mm), muscle surface color (Minolta L*a*b*), pH, exudates in the packages (%), microbial characteristics, and off‐odor were assessed in the packaged fillets. Increased SGS treatment time (2 versus 12 h) before MA packaging increased the CO₂ content in the packaged fillets and counteracted package collapse. High package filling degree (51.8%) (low gas to product volume ratio) gave significantly (P < 0.001) lower CO₂ content in head space than normal filling degree (29.7%). Color, pH, and package exudates were not affected by SGS treatment. Aerobic plate count (APC), Enterbacteriaceae count (EC), and lactic acid bacteria (LAB) increased significantly (P < 0.001) at each sampling during storage (5, 11, 17, and 24 d). SGS treatment significantly (P < 0.015) decreased APC, EC, and Pseudomonas spp. counts (PC) compared with no SGS treatment. Filling degree did not have a significant effect on the investigated microbiological characteristics. Off‐odor scores correlated highest with EC (r²_(adj)= 0.82). Fillets SGS treated in 12 h were the only one not rejected at off‐odor evaluation on day 24. The samples stored in air spoiled after 5 d. SGS treatment in combination with MAP can be used successfully on chicken breast fillets to improve the microbiological (APC, EC, and PC) and sensorial characteristics, and in addition reduce package collapse and possibly increase the filling degree.     

Wave-Ice Interactions in Barents Sea Marginal Ice Zone

The motion of two ice floes in a wave field were simultaneously measured with two six degree of freedom instruments in the Barents Sea Marginal Ice Zone. The heave motion amplitude was used to interpret the wave amplitude. The response of the floes in a wave field relative to the wave amplitude at several different frequencies was investigated through spectral analysis. Comparison of the calculated wave amplitude at these two locations gave the wave attenuation coefficient, which was somewhat larger than those reported from previous field experiments; this is perhaps due to both the relatively higher concentration and the types of ice found during the investigation. The heave, sway, surge, pitch, roll, and yaw amplitudes were compared with the wave amplitude. The nondimensional response amplitude operators have similar values in the directions parallel and perpendicular to the wave direction; the response amplitude operators in pitch, heave, and surge agree with the predictions from previous theoretical studies. Similar responses in the sway, roll, and yaw directions indicate significant floe-floe interactions. These floe interactions may also contribute to the observed wave attenuation. Finally, there was essentially no difference between the floe energy attenuation and the wave attenuation.     

Development and optimization of a new processing approach for manufacturing topical liposomes-in-hydrogel drug formulations by dual asymmetric centrifugation

Objective: The objective of the present study was to utilize dual asymmetric centrifugation (DAC) as a novel processing approach for the production of liposomes-in-hydrogel formulations.

Materials and methods: Lipid films of phosphatidylcholine, with and without chloramphenicol (CAM), were hydrated and homogenized by DAC to produce liposomes in the form of vesicular phospholipid gels with a diameter in the size range of 200?300?nm suitable for drug delivery to the skin. Different homogenization processing parameters were investigated along with the effect of adding propylene glycol (PG) to the formulations prior to homogenization. The produced liposomes were incorporated into a hydrogel made of 2.5% (v/v) soluble β-1,3/1,6-glucan (SBG) and mixed by DAC to achieve a homogenous liposomes-in-hydrogel-formulation suitable for topical application.

Results and discussion: CAM-containing liposomes with a vesicle diameter of 282?±?30?nm and polydispersity index (PI) of 0.13?±?0.02 were successfully produced by DAC after 50?min centrifugation at 3500?rpm, and homogenously (Conclusion: We managed to develop a relatively fast and reproducible new method for the production of liposomes-in-hydrogel formulations by DAC.     

Using electricity as a tool in quality studies of Atlantic salmon

In order to reveal what role anaerobe muscle activity has on the fillet quality in Atlantic salmon (Salmo salar), 18 rested fish were killed on site and immediately filleted. One fillet was used as control group while the other was electrically exercised using 10 V, 5 Hz pDC for 3 min. Fillet weight and muscle pH was measured before the fillets were wrapped in aluminum foil and stored on ice. After 7 days muscle pH, color, and weight was measured. Texture profile analysis (TPA) was estimated using a 20 mm cylindrical probe compressing either at 40, 60 or 80% into the fillet and the shear force was estimated by slicing standardized muscles samples with a blade. Results show that electrical stimulation forces the muscle to contract and the muscle pH to drop by 0.5 units, leading to higher drip loss and loss of color. Comparing the fillets in pairs (paired t test) strengthens evidence on drip loss and color loss, but revealed also softer texture. Optimum compression rate for detecting differences in salmon muscle is at 60% compression. We conclude that electrical stimulation is a powerful tool for simulating anaerobe muscle activity enabling comparative studies within the same individual, hence isolating the variation amongst individuals and the location of sampling. Furthermore electrical stimulation reduces the need for live animal experimentation in quality studies.