USE OF SENSORY EVALUATION FOR MEASURING DEODORIZING EFFECTS OF AN AIR CONDITIONER

The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R² values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.     

Macroinvertebrate community structure,secondary production and trophic‐level dynamics in urban streams affected by non‐point‐source pollution

1. Despite non‐point‐source (NPS) pollution being perhaps the most ubiquitous stressor affecting urban streams, there is a lack of research assessing how urban NPS pollution affects stream ecosystems. We used a natural experimental design approach to assess how stream macroinvertebrate community structure, secondary production and trophic structure are influenced by urban NPS pollution in six streams. 2. Differences in macroinvertebrate community structure and secondary production among sites were highly correlated with stream‐water specific conductivity and dissolved inorganic phosphorus (DIP) concentrations. Macroinvertebrate richness, the Shannon diversity index and the Shannon evenness index were all negatively correlated with specific conductivity. These patterns were driven by differences in the richness and production of EPT and other intolerant taxa. Production of the five most productive taxa, tolerant taxa, non‐insect taxa and primary consumers were all positively correlated with stream‐water DIP. 3. Despite the positive correlation between primary consumer production and DIP, there was no correlation between macroinvertebrate predator production and either total or primary consumer macroinvertebrate production. This was observed because DIP was positively correlated with the production of non‐insect macroinvertebrate taxa assumed to be relatively unavailable for macroinvertebrate predator consumption. After removing production of these taxa, we observed a strong positive correlation between macroinvertebrate predator production and production of available prey. 4. Our results suggest that urban NPS pollution not only affects macroinvertebrate community structure, but also alters secondary production and trophic‐level dynamics. Differences in taxon production in our study indicate the potential for altered energy flow through stream food webs and potential effects on subsidies of aquatic insect prey to riparian food webs.     

防止逃鱼用的拦网和拦栅的合理规格的研究

目前一般较大的湖泊水库放养鱼类的回捕率颇低,逃鱼是重要原因之一。为了确定拦鱼用的网和栅所应采取的规格,测量了2,227尾(3—16厘米)鲢、鳙、草、青鱼种的全长,最大周长、头宽、颅宽的各个数值,推算出全长与最大周长、头宽、颅宽的迥归方程式及它们的95%的可信限。通过实验,观察到在流水条件下,鱼种能溯水穿越较自身最大周长为小的拦网网目或较头宽为小的拦栅栅距而逃逸。作者称这种能力为“穿拦系数”(用Kg 或Kp 表示)。并测出在武昌东湖某些生活污水进水口处,1973年3—4月份白鲢鱼种的穿拦系数按Kg 计算为1.5,按Kp 计算为1.2。作者建议在静水或出水口处,设置拦鱼用的拦网的网目长度不得超过所投放色种的最大周长的95%的可信限的下限的1/2,各种拦栅的栅距不得超过鱼种的头宽的95%可信限的下限。而在流水条件下,在确定所应采取的拦网网目或拦栅栅距时,还应该考虑“穿拦系数”在内。文末附有检索表,列举了鲢、鳙、草、青鱼种(3—16厘米)相应于全长值的最大周长值、头宽值、颅宽值以及它们的95%可信限的上限和下限的各个数值,供确定拦网网目和拦栅栅距的规格时参考。       

Life stage‐dependent effects of experimental heat waves on an insect herbivore

1. Worldwide concern about the consequences of climate change has prompted efforts to understand and predict the responses of populations to changes in temperature. 2. A heat wave can adversely affect organisms, may affect different life stages differently, and could decrease populations. In this study, green peach aphid [Myzus persicae (Sulzer)] nymphs, reproductive adults, and late‐reproductive adults were exposed to a heat wave, defined as 5 °C above the control temperature regime for five consecutive days. 3. The negative effects of experimental warming on development, reproduction, and survival negatively affected population growth. Nymphs and reproductive adults were more severely impacted than late‐reproductive adults. 4. Experiments designed to mimic temperature regimes can assess the direct effects of climate change on individuals and populations. Our study highlights the importance of assessing the life stage‐specific responses to heat stress.     

Application of r/K selection to macroinvertebrate responses to extreme floods

1. Due to climate change, contemporary climate scenarios forecast an increase in extreme weather, which may have considerable impacts on the world's riverine ecosystems. Because the flow regime is a primary determinant of the structure and function of lotic ecosystems, changes in the weather could fundamentally alter these ecosystems through changes in hydrologic disturbance regimes. 2. In this paper, we use the abundance/biomass comparison (ABC) method, based on r/K selection theory, and event probability distribution to characterise the responses of macroinvertebrates in Taiwan mountain streams to extreme floods. 3. Severe impacts on macroinvertebrates, resulting in a large shift in community structure toward r‐selected taxa, usually were observed the year after extreme floods. 4. Macroinvertebrate communities dominated by K‐selected taxa had more individuals with traits conferring resistance to flooding disturbance, while those dominated byr‐selected taxa had more individuals with traits conferring resilience. 5. This relationship between the changes in flow regime and the ecological response of r‐ and K‐selected taxa may be exploited to understand the potential effects of flood extremes in the future, and to keep decision makers informed about the ecological consequences of climate‐mediated changes to hydrological regimes.