USAGE BEHAVIOR OF MEAT PRODUCTS BY AUSTRALIANS AND HONG KONG CHINESE: A COMPARISON OF FREE CHOICE AND CONSENSUS PROFILING

Australian and Hong Kong Chinese male and female consumers, aged 20 to 30 years, evaluated a range of 16 meat products using two questionnaires. One questionnaire comprised the 12 most frequently used terms by consumers to describe how, when and where they would most often consume each product. The alternate questionnaire for each individual comprised free choice vocabulary. Half of each consumer sample used the consensus questionnaire and the other half, the free choice questionnaire first, and indicated how often they would consume each meat product in the various contexts listed using graphic line scales of 100 mm anchored at either end by the words ‘never’ and ‘always’. After an interval of time, the alternate questionnaire was completed. It was found that similar conclusions can be drawn about major contextual dimensions either by principal component analysis of data from a consensus questionnaire or by generalized Procrustes analysis of data from free choice profiling.     

Therapeutic efficacy of novel memantine nitrate MN‐08 in animal models of Alzheimer’s disease

Alzheimer''s disease (AD) is a leading cause of dementia in elderly individuals and therapeutic options for AD are very limited. Over‐activation of N‐methyl‐D‐aspartate (NMDA) receptors, amyloid β (Aβ) aggregation, a decrease in cerebral blood flow (CBF), and downstream pathological events play important roles in the disease progression of AD. In the present study, MN‐08, a novel memantine nitrate, was found to inhibit Aβ accumulation, prevent neuronal and dendritic spine loss, and consequently attenuate cognitive deficits in 2‐month‐old APP/PS1 transgenic mice (for a 6‐month preventative course) and in the 8‐month‐old triple‐transgenic (3×Tg‐AD) mice (for a 4‐month therapeutic course). In vitro, MN‐08 could bind to and antagonize NMDA receptors, inhibit the calcium influx, and reverse the dysregulations of ERK and PI3K/Akt/GSK3β pathway, subsequently preventing glutamate‐induced neuronal loss. In addition, MN‐08 had favorable pharmacokinetics, blood‐brain barrier penetration, and safety profiles in rats and beagle dogs. These findings suggest that the novel memantine nitrate MN‐08 may be a useful therapeutic agent for AD.     

Involvement of Thylakoid Overenergization in Tentoxin-Induced Chlorosis in Nicotiana spp

The purpose of this work was to clarify the mechanism of tentoxin-induced chlorosis in Nicotiana spp. seedlings. We found that chlorosis does not correlate with the inhibition of chloroplast ATP synthesis in vivo, since it occurs at tentoxin concentrations far higher than that required for the inhibition of photophosphorylation measured in the same seedlings. However, tentoxin-induced chlorosis does correlate with in vivo overenergization of thylakoids. We show that tentoxin induces overenergization in intact plants and isolated thylakoids, probably via multiple interactions with ATP synthase. Furthermore, gramicidin D, a protonophore that relieves overenergization, also relieves chlorosis. Two lines of evidence suggest that reactive oxygen species may be involved in the process of chlorosis: ascorbate, a quencher of oxygen radicals, significantly protects against chlorosis, whereas transgenic Nicotiana spp. mutants overexpressing chloroplast superoxide dismutase are partially resistant to tentoxin-induced chlorosis. It is proposed that chlorosis in developing seedlings results from overenergization of thylakoids, which leads to the generation of oxygen radicals.     

Stress-induced changes in carbon sources for isoprene production in Populus deltoides

Isoprene is emitted from leaves of numerous plant species and has important implications for plant metabolism and atmospheric chemistry. The ability to use stored carbon (alternative carbon sources), as opposed to recently assimilated photosynthate, for isoprene production may be important as plants routinely experience photosynthetic depression in response to environmental stress. A CO₂‐labelling study was performed and stable isotopes of carbon were used to examine the role of alternative carbon sources in isoprene production in Populus deltoides during conditions of water stress and high leaf temperature. Isotopic fractionation during isoprene production was higher in heat‐ and water‐stressed leaves (?8.5 and ?9.3‰, respectively) than in unstressed controls (?2.5 to ?3.2‰). In unstressed plants, 84–88% of the carbon in isoprene was derived from recently assimilated photosynthate. A significant shift in the isoprene carbon composition from photosynthate to alternative carbon sources was observed only under severe photosynthetic limitation (stomatal conductance < 0.05 mol m^?2 s^?1). The contribution of photosynthate to isoprene production decreased to 77 and 61% in heat‐ and water‐stressed leaves, respectively. Across water‐ and heat‐stress experiments, allocation of photosynthate was negatively correlated to the ratio of isoprene emission to photosynthesis. In water‐stressed plants, the use of alternative carbon was also related to stomatal conductance. It has been proposed that isoprene emission may be regulated by substrate availability. Thus, understanding carbon partitioning to isoprene production from multiple sources is essential for building predictive models of isoprene emission.     

赤红壤早稻田甲烷排放通量及其影响因素

用封闭箱法对广东省赤红壤早稻田CH4排放通量进行了观测。结果表明,CH4排放有明显的季节变化规律,3个排放高峰分别出现在水稻分蘖末期、孕穗抽穗期和乳熟期,平均通量为5.7mg.m-2.h-1。在测定期内,CH4排放与5和10cm土壤温度呈显著正相关,与土壤Eh呈显著负相关,与土壤pH值、水层深浅相关不明显。     

Black Point is associated with reduced levels of stress, disease- and defence-related proteins in wheat grain

Black Point in wheat is a dark discoloration at the embryo end of the grain, which causes substantial financial losses to wheat growers due to down-grading of otherwise high-grade wheat. There does not appear to be a single cause for Black Point, although evidence suggests that fungal infection is the main link to Black Point symptoms. We sought to identify grain proteins from Black Point-affected and Black Point-free wheat cultivar SUN239V, which is known to be very susceptible to Black Point. The proteomes of both the germ and endosperm-bran components of Black Point-affected and Black Point-free grain were compared using two-dimensional gel electrophoresis (2-DE) with six replicate gels run for each protein sample. Approximately 1478 discrete protein spots were found in 2-DE gels from the germ fraction of the grain, of which 354 were identified by mass spectrometry (MS). Similarly, 1360 discrete protein spots were found from the endosperm-bran fraction, of which 303 were identified by MS. No proteins of fungal or bacterial origin were positively identified, suggesting that, at least in some cases, Black Point is not associated with microbial activity. Of the germ proteins, 252 were differentially expressed in Black Point-affected tissue, with 67 of these proteins identified by MS. Of the endosperm-bran proteins, 317 were differentially expressed in Black Point-affected tissue, with 86 identified. The largest of 12 functional classes to which the differentially abundant proteins were assigned was the 'stress' class, i.e. products of genes associated with stress, disease and defence. Higher levels of these proteins were found in Black Point-free grain, suggesting that protection from the disease might be afforded by increased levels of the 'stress' proteins.     

Developmental Variability of Photooxidative Stress Tolerance in Paraquat-Resistant Conyza

Paraquat-resistant hairy fleabane (Conyza bonariensis L. Cronq.) has been extensively studied, with some contention. A single, dominant gene pleiotropically controls levels of oxidant-detoxifying enzymes and tolerance to many photooxidants, to photoinhibition, and possibly to other stresses. The weed forms a rosette on humid short days and flowers in dry long days and, thus, needs plasticity to photooxidant stresses. In a series of four experiments over 20 months, the resistant and susceptible biotypes were cultured in constant 10-h low-light short days at 25[deg]C. Resistance was measured as recovery from paraquat. The concentration required to achieve 50% inhibition of the resistant biotype was about 30 times that of the susceptible one just after germination, increased to >300 times that of the susceptibles at 10 weeks of growth, and then decreased to 20-fold, remaining constant except for a brief increase while bolting. Resistance increased when plants were induced to flower by long days. The levels of plastid superoxide dismutase and of glutathione reductase were generally highest in resistant plants compared to those of the susceptibles at the times of highest paraquat resistance, but they were imperceptibly different from the susceptible type at the times of lower paraquat resistance. Photoinhibition tolerance measured as quantum yield of oxygen evolution at ambient temperatures was highest when the relative amounts of enzymes were highest in the resistant biotype. Resistance to photoinhibition was not detected by chlorophyll a fluorescence. Enzyme levels, photoinhibition tolerance, and paraquat resistance all increased during flowering in both biotypes. Imperceptibly small increases in enzyme levels would be needed for 20-fold resistance, based on the moderate enzyme increases correlated with 300-fold resistance. Thus, it is feasible that either these enzymes play a role in the first line of defense against photooxidants, or another, yet unknown mechanism(s) facilitate(s) the lower level of resistance, or the enzymes and unknown mechanisms act together.