Influence of pH and iota-carrageenan concentration on physicochemical properties and stability of beta-lactoglobulin-stabilized oil-in-water emulsions

The influence of pH and iota-carrageenan concentration on the properties of beta-lactoglobulin (beta-Lg)-stabilized oil-in-water emulsions was investigated by measuring the particle charge, particle size distribution, and creaming stability. Emulsions containing droplets stabilized by beta-Lg were produced by homogenization, and then, iota-carrageenan was added. At pH 3, the droplet charge did not change for iota-carrageenan concentrations 相似文献   

基于银川地区水质的小白菜营养液配方优选

应用四元二次通用旋转组合设计,采用DFT无土栽培,在二代节能日光温室内研究了营养液配方中的N(NO3--N)、P、K、Ca 4种元素对小白菜生长的影响,得到了产量与4种元素之间的回归方程。结果表明,4种元素对小白菜产量影响的大小顺序是NKPCa;小白菜N与Ca的交互效应在较低水平时呈一定的正相关关系,在较高水平时存在着一定的负相关关系;通过计算机模拟寻优,得到小白菜达到单株最高产量148.75 g时,最优的N、P、K、Ca 4因子浓度依次为9、0.5、4.5和3.0 mmol.L-1。经过验证,最优配方处理下的小白菜生长势、根系活力、产量、品质以及全氮磷钾含量均高于对照。     

Multiple spawning events promote increased larval dispersal of a predatory fish in a western boundary current

Transport of larvae by ocean currents is an important dispersal mechanism for many species. The timing and location of spawning can have a large influence on settlement location. Shifts in the known spawning habitat of fish, whether due to climate or the discovery of new spawning stock, can influence the distribution of juveniles and our understanding of connectivity. The globally distributed species; Pomatomus saltatrix, is one such example where a previously unrecognised summer spawning event and a more southern latitudinal extent was recently reported for the southwest Pacific population. Although restrictions are in place to protect the traditional spawning event, the importance of the newly recognised summer spawning event is uncertain. Here, we investigate larval dispersal of P. saltatrix using particle tracking simulations to identify the contributions of the different spawning events to settlement. By modelling dispersal of larvae released in northern and mid‐latitude regions over the Austral spring and summer, we show that the newly recognised mid‐latitude summer spawning event contributes over 50% of the larvae reaching southern latitudes. This is due to a reduced (1–2 days) pelagic larval duration (associated with temperature), resulting in reduced larval mortality, and the seasonal (summer) strengthening of the East Australian Current (EAC) transporting particles ~50 km further south. These findings demonstrate that in dynamic boundary current systems such as the EAC, the final settlement location of larvae that are transported by ocean currents can vary considerably depending on the timing and location of spawning and that multiple spawning events are important for maximum dispersal.     

Large‐scale,seasonal habitat use and movements of yellow American eels in the St. Lawrence River revealed by acoustic telemetry

Large‐scale habitat use and movements of yellow American eels (Anguilla rostrata) from the St. Lawrence River were examined using acoustic telemetry from early summer to late fall in 2010 and 2011. Sixty‐seven eels were tagged, and their passage or presence was recorded using fixed acoustic arrays covering a 400 km distance along the St. Lawrence River and Estuary. Sixty‐four per cent of the 67 tagged eels were detected. Most eels were detected at only one array; the closest to their release location and at several occasions during the tracking period, suggesting a high proportion of freshwater residency in the upstream part of the St. Lawrence River. Downstream movements towards the brackish estuary (63–418 km distance) were demonstrated for 16.4% of the eels, particularly for those caught at the most downstream site that is close to the brackish estuary. Our results strongly suggest a lower activity of freshwater resident yellow eels during summer, a behaviour that may be related to day length, which defines time available for their nocturnal foraging. Indeed, yellow eels were detected primarily at night; no effect of moon phase was revealed. Movements in the vicinity of arrays (up to 116 km in the fluvial estuary) were suggested and smaller‐scale movements within Lac St. Louis were demonstrated, highlighting a yellow‐eel home range far more extensive than previously reported in smaller systems. Evidence for within‐season homing and site fidelity is also reported.     

Feeding behaviour of green mussels,Perna viridis farmed in Marudu Bay,Malaysia

The green mussel, Perna viridis is known to have the ability to selectively ingest certain suspended particles from water. However, the preferential ingestion of specific phytoplankton taxa by P. viridis under different environmental conditions is not well understood. A study was undertaken to identify the phytoplankton taxa that are preferentially ingested and rejected by P. viridis in different environmental conditions at Marudu Bay, Malaysia. Phytoplankton abundance and composition in stomach and surrounding waters were determined microscopically. The gonad development stages of P. viridis and various environmental parameters of the bay including temperature, salinity, dissolved oxygen, current speed, pH, visibility, chlorophyll a, nutrients concentration and suspended particles were also determined. Results of current study demonstrated that selective ingestion in P. viridis was mainly influenced by seston concentration, phytoplankton abundance and composition. At high seston concentration with low phytoplankton abundance, P. viridis selectively ingested Coscinodiscus spp. In contrast, P. viridis was found to ingest wider range of phytoplankton at low seston concentration and high phytoplankton abundance. Interestingly, Chaetoceros spp. and Bacteriastrum spp. were selectively rejected by P. viridis in both high and low seston conditions. Nevertheless, no selective ingestion behaviour was evidenced in low seston with low phytoplankton conditions. Besides phytoplankton, zooplankton has also contributed significantly in the diet of P. viridis, where high numbers of copepod and bivalve larvae were found in the stomach. The findings of current study can be useful in determining potential farming sites for green mussel in future.     

Experimental tuberculosis in red deer (Cervus elaphus)

This study was designed to investigate experimental Mycobacterium bovis infection of red deer (Cervus elaphus). Three intravenously inoculated deer (dose 10 microg-1000 microg) developed miliary tuberculosis of the lungs and all died within 28 days of being infected. No clinical illnesses were observed in four subcutaneously (dose 1 microg-1000 microg) and three intratracheally (dose 10 microg-100 microg) inoculated deer. At the conclusion of the experiment six weeks post inoculation, these seven animals reacted to 2 mg/ml of bovine purified protein derivative. The principal lesions in the intravenously inoculated deer were in the lungs which had multiple foci of necrosis containing very large numbers of acid fast bacilli. A gradation of changes was seen in the subcutaneously inoculated deer. The animal receiving the 1 microg dose only had lesions at the injection site and the draining prescapular lymph node. Deer receiving higher doses also had histopathological changes in the lungs and liver. Microscopic changes in the intratracheally infected animals were restricted to the thoracic cavity. The ability of the deer to controlled infection was related to the route of inoculation.     

Difficulties in the molecular diagnosis of Helicobacter rodent infections

Molecular diagnostic methods using the polymerase chain reaction (PCR) are the gold standard in Helicobacter diagnostics. Most rely on the amplification of parts of the 16S rRNA gene sequence. Therefore, the validity and accuracy of results depends heavily on the PCR design and the time of its publication because new sequences are continually being submitted to databases. Here we report the presence of helicobacter in commercially bred mice supposedly free of this infection. Furthermore, three out of six different commercial laboratories performing helicobacter testing on the same spiked faecal samples failed to detect and identify H. hepaticus. We designed a simple generic PCR assay that amplifies a 261bp amplicon spanning two of the seven variable regions in the 16S rRNA of helicobacter. Using this assay together with an established generic assay designed by Bohr [Bohr, U.R., Primus, A., Zagoura, A., Glasbrenner, B., Wex, T., Malfertheiner, P., 2002. A group-specific PCR assay for the detection of Helicobacteraceae in human gut. Helicobacter 7, 378-383] and then cloning and sequencing their products, we detected the H. hepaticus used in the study that three commercial laboratories failed to detect. We think these assays together could detect all the currently known species of helicobacter and hopefully the new ones as well. In addition, we have been able to identify different species of helicobacter and their relative proportions infecting a single animal. This information has also shown that some helicobacters may have a much broader host range than originally reported.     

Healthy soils for sustainable food production and environmental quality

Soil is the foundation for sustainable food production and environmental protection. Created by unsustainable land management practices and a range of social, economic and environmental drivers, soil degradation and pollution have been an ongoing threat to international food security and environmental quality. Soil degradation and pollution assessments are, however, often focused on the soil itself with little scope to devise new soil management approaches that match food production systems and/or environmental protection. This study draws lessons from an Australia-China Joint Research Center Program, Healthy Soils for Sustainable Food Production and Environmental Quality: a research platform that has brought together multi-disciplinary approaches from world-renowned universities and research organizations in Australia and China. To this end, a framework is presented for future soil management in a new way that combines excellence in research, industry and policymakers in a partnership that will ensure not only the right focus of the research but also that high-quality outputs will be transferable to industry and end-users.     

Erratum to: Woody habitats promote pollinators and complexity of plant–pollinator interactions in homegardens located in rice terraces of the Philippine Cordilleras

Paddy and Water Environment -     

Cardiac muscle mass distribution in the domestic turkey and relationship to electrocardiogram.

Ventricular weights were measured in 20-week-old male and female heavy turkeys, and electrocardiograms (ECGs) were recorded in 10- and 20-week-old male and female heavy turkeys. Twenty-week-old males had heavier relative left ventricular and total ventricular weights than females of the same age. Left-to-right ventricular weight ratios were 4.4:1 in males and 4.5:1 in females. Heart rate was faster in young birds and in females, and that influenced the duration of the intervals of the ECG. Wave amplitudes were smaller in 10-week-old turkeys than in 20-week-old turkeys. There was no correlation between electrocardiographic parameters and ventricular weights of male and female turkeys. Two-dimensional ECGs were therefore found to be of minimal value for detecting turkeys with heavier ventricles.