Heat and carbon dioxide generated by honeybees jointly act to kill hornets

We have found that giant hornets (Vespa mandarinia japonica) are killed in less than 10 min when they are trapped in a bee ball created by the Japanese honeybees Apis cerana japonica, but their death cannot be solely accounted for by the elevated temperature in the bee ball. In controlled experiments, hornets can survive for 10 min at the temperature up to 47°C, whereas the temperature inside the bee balls does not rise higher than 45.9°C. We have found here that the CO₂ concentration inside the bee ball also reaches a maximum (3.6 ± 0.2%) in the initial 0–5 min phase after bee ball formation. The lethal temperature of the hornet (45–46°C) under conditions of CO₂ concentration (3.7 ± 0.44%) produced using human expiratory air is almost the same as that in the bee ball. The lethal temperature of the honeybee is 50–51°C under the same air conditions. We concluded that CO₂ produced inside the bee ball by honeybees is a major factor together with the temperature involved in defense against giant hornets.     

Irrigation system and land use effect on surface water quality in river, at lake Dianchi, Yunnan, China

The surface water samples were collected in river Dahe and its tributaries, which flow into severely eutrophic lake Dianchi, Yunnan Province, China, in order to elucidate factors controlling water quality fluctuations. The temporal and spatial distribution of water quality tendency was observed. The water quality of each river is dependent on the hydrology effect such water gate and circulating irrigation system. We must consider the hydrology effect to accurately understand water quality variations of river in this study field. In river without highly circulating irrigation system or water gate effect, the downstream nitrate nitrogen (NO₃-N) concentration increase occurred in area dominated by open field cultivation, whereas the NO₃-N concentration was constant or decreased in area dominated by greenhouse land use. This result suggests that greenhouse covers the soil from precipitation, and nitrate load of greenhouse could be less than that of open field cultivation while the rainfall event. In the upper reaches of river, where is dominated by open field cultivation, there were no sharp increase dissolved molybdate reactive phosphorus and total phosphorus concentration, but P load was accumulated in the lower reaches of river, whose predominant land use is greenhouse. Although the P sources is unclear in this study, greenhouse area may have potential of P loads due to its high P content in greenhouse soil. Considering hydrology effect is necessary to determine what the major factor is influencing the water quality variation, especially in area with highly complicated irrigation system in this studying site.     

Gas reforming and tar decomposition performance of nickel oxide (NiO)/SBA-15 catalyst in gasification of woody biomass

In the gasification of biomass, it is necessary to limit the amount of by-product tar and increase the yields of hydrogen (H₂) and carbon monoxide (CO) (syngas). Therefore, we conducted gasification and reforming experiments on woody biomass using an electric tubular furnace, to evaluate the gas reforming and tar decomposition performance of a NiO/SBA-15 catalyst. As a result, we found that this catalyst is effective for H₂ production. It is believed that the increase in H₂ volume due to the catalyst occurs through a steam reforming reaction involving hydrocarbons, including methane (CH₄), and the water-gas shift reaction. With respect to the influence of the gasifying agent on the reforming effect of the catalyst, the amount of generated carbon dioxide (CO₂) and hydrogen (H₂) increases because the shift reaction is promoted by supplying steam. On the other hand, it was inferred that the shift reaction rarely occurred because it approaches equilibrium by supplying O₂. Furthermore, it is suggested that light aromatic hydrocarbons are decomposed by the catalyst.

Implications: The mesoporous silica catalyst NiO/SBA-15 was highly effective for H₂ production and decomposition of light aromatic compounds in the gasification of woody biomass. In the catalyst reaction, supplying steam promoted H₂ production. From thermodynamic analysis and discussion, it was also inferred that supplying O₂ might prevent the water gas shift reaction. The results are useful for designing a process needed for rich H₂ production and gas refining process for further use of syngas.     

Identification of microbial populations contributing to nitrification-associated nitrous oxide emission during cattle manure composting process with forced aeration

Journal of Material Cycles and Waste Management - This study was conducted to clarify the fates of whole nitrogen cycle-associated microorganisms during laboratory-scale composting of cattle manure...     

Synthesis and characterizations of Zr(IV)-loaded orange waste for effective sequestration of Mo(VI) and W(VI) from water

Journal of Material Cycles and Waste Management - An efficient and environmentally benign biosorbent for Mo(VI) and W(VI) sequestration was developed by loading Zr(IV) ions onto Saponified Orange...     

Analyzing flood risk and related impacts to urban communities in central Vietnam

This study aims at understanding flood risks and their impact on a community, in order to enhance communities’ resilience and adaptive capacity to these threats. It also investigates the possibility of looking at and handling risk from a resilience point of view. Therefore, while a conventional risk management process is employed in this study, social, physical, economic, and institutional dimensions of resilience are also included in order to grasp the extent of risks and the ways in which communities face, cope with, and recover from flooding. Findings showed that there was no significant difference in the perception of flood risk among household heads educated up to secondary school level, suggesting that they believe floods are purely natural events. Those with a higher level of education (high school and above) (82.7 % of respondents) were aware that flood disasters are the result of hazard and vulnerability combined. In addition, social dynamics were apparently strengthened by such disasters, which resulted in cohesion and mutual help following floods in some wards. Also, households with more sources of income and more savings appear to recover faster than others after a flooding event. With regard to governance and networks, greater efforts have to be made by local institutions to ensure basic functioning during and after disaster events and to invest more into risk reduction activities. However, further studies need to be conducted to clarify the understanding of the impact flood disasters have on the environment and community lives and livelihoods in general, as traditional coping strategies, although still practical, no longer suffice in the face of changes in climate and environment.     

Surgical examination of male genital function of calopterygid damselflies (Odonata)

Male genitalia show rapid and divergent evolution. It is rarely determined whether variation in male genital morphology influences male reproductive success. Male damselflies possess a unique aedeagus with a re-curved head and spiny lateral processes, and most females have two sperm storage organs, a spherical bursa copulatrix and a tubular spermatheca. Previous studies have indicated that the re-curved head may remove bursal sperm, whereas the lateral processes remove spermathecal sperm. However, we need more direct evidence of these functions. We compared sperm number in female sperm storage organs by interrupting copulation to examine sperm removal by the male. In Calopteryx cornelia, males removed almost all bursal sperm but only partially removed spermathecal sperm. In contrast, females of Mnais pruinosa store sperm primarily in the bursa, and males removed only bursal sperm. To examine the functions of male spiny lateral processes, we compared mating behaviour between control and experimental males from which we removed (cut) the lateral processes. In C. cornelia, cutting of the lateral processes resulted in a decreased number of abdominal movements during copulation and no removal of spermathecal sperm. The amount of bursal sperm removed during copulation also decreased in experimental males compared to the unmanipulated males. However, in M. pruinosa, the experimental removal of male lateral processes did not decrease the abdominal movements and little affected the removal of bursal sperm. Inter-specific differences between C. cornelia and M. pruinosa may be caused by variation in the strategies of female sperm storage.     

Post furnace formation of PCDDs and PCDFs in MSWI: Observations in an incinerator installed with quench reactor

Reduction of dioxin emission by a quench reactor with lime spray was investigated in relation to post furnace formation pathways. Results showed that the quench reactor performed to supress post furnace reaction of precursor molecules to form selected congeners of PCDD and PCDF.     

Modeling the influence of biogenic volatile organic compound emissions on ozone concentration during summer season in the Kinki region of Japan

Tropospheric ozone adversely affects human health and vegetation, and biogenic volatile organic compound (BVOC) emission has potential to influence ozone concentration in summer season. In this research, the standard emissions of isoprene and monoterpene from the vegetation of the Kinki region of Japan, estimated from growth chamber experiments, were converted into hourly emissions for July 2002 using the temperature and light intensity data obtained from results of MM5 meteorological model. To investigate the effect of BVOC emissions on ozone production, two ozone simulations for one-month period of July 2002 were carried out. In one simulation, hourly BVOC emissions were included (BIO), while in the other one, BVOC emissions were not considered (NOBIO). The quantitative analyses of the ozone results clearly indicate that the use of spatio-temporally varying BVOC emission improves the prediction of ozone concentration. The hourly differences of monthly-averaged ozone concentrations between BIO and NOBIO had the maximum value of 6 ppb at 1400 JST. The explicit difference appeared in urban area, though the place where the maximum difference occurred changed with time. Overall, BVOC emissions from the forest vegetation strongly affected the ozone generation in the urban area.