No evidence of predator odor avoidance in a North American bird community

Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian life.Prior studies investigating predator avoidance behaviors in response to predator odor cues have produced mixed results across species and contexts.Here we assess if a community of birds in eastern Pennsylvania displays avoidance behaviors towards predator odor cues in a natural foraging setting.We use clay caterpillars to measure foraging activity by birds in the presence of predator(bobcat)urine,non-predator(rabbit)urine,and water controls in two different environmental contexts(field vs.forest).Although we detected a weak trend for birds to forage less at predator urine-treated sites,we found no significant difference in avian foraging between the site types.We did find that foraging rates between environmental contexts changed significantly over the course of the experiment,with forest sites showing decreasing foraging rates and field sites showing increasing foraging rates.Our results reinforce the published literature that avoidance of predator odors by birds may not be ubiquitous across contexts and species.

Progress in Research on Insect Olfactory Perception of Habitat Odor Molecules

A highly sensitive olfactory system allows insects to precisely identify and position volatile compounds from different sources in their habitats,and plays a crucial role in their foraging,mating,and oviposition activities.During evolution,insects have successfully developed a large and complex olfactory system to adapt to heterogeneous environments,enabling the maintenance of inset population.A comprehensive examination of the olfactory system of insects may therefore yield novel insights into the development of innovative pest control and prevention strategies,as well as the study of olfactory mechanisms in vertebrates and even humans.This paper outlines the current state of research into the signal transduction mechanism by which insects perceive the olfactory molecules of their habitats.The aim of this review is to provide a reference point for future studies into the olfactory perception mechanism and its potential applications in pest management.

Volatile Solid and Bury Period Influence on Odorous Material Production in Simulating Landfill Treatment

Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.

Orientation of larval and juvenile horseshoe crabs Limulus polyphemus to visual cues: Effects of chemical odors

Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods.Yet,little is known about the ability of early life history stages to detect and respond to visual cues.We examined the visuallydirected movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes.The studytested the hypotheses that (1) larval and juvenile crabs can detect and respond to visual targets and (2) the direction of orientationvaries with the presence of chemical cues associated with settlement habitats.Orientation of larval and juvenile crabs torectangles subtending angles from 30-330° was tested in a circular arena containing water that either lacked estuarine chemicalcues (offshore water) or contained odors from aquatic vegetation or known predators.In the absence of chemical odors,larvaeoriented toward and juveniles moved away from dark horizons subtending angles > 60°.When placed in water containingchemical odors from potential nursery habitats,including the seagrasses Halodule wrightii and Syringodium filiforme,crabsreversed their direction of orientation relative to their responses in offshore water.Odors from two known predators,themummichug Fundulus grandis and blue crab Callinectes sapidus,had no affect on the orientation of larvae.Yet,juvenilesresponded to both odors by moving toward the visual target.Results support the hypothesis that the visual orientation of larvaland juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoesan ontogenetic shift following

Sensory-directed flavor analysis of key odorants compounds development of French fries and oils in the break-in,optimum and degrading frying stage

The flavor is a decisive sensory characteristic that determines the popularity of French fries(FFs).During high-oleic rapeseed oil(RO)frying,the flavor development of FFs showed three noticeable stages including break-in(3.5%-7.5%of total polar compounds(TPC)),optimum(7.5%-22.18%of TPC),and degrading stages(above 22.18%of TPC).Further,in order to distinguish the key aroma compounds in each stage,the FFs prepared in RO at TPC of 3.5%(FF4),14.5%(FF15),and 26.96%(FF27)and their relevant oils(RO4,RO15,RO27)were selected for sensory-directed analysis.The results revealed that the FF4 had low contents of(E,E)-2,4-decadienal(deep-fried odor)which also caused lower sensory score in FF4 sample.The higher contents of(E,E)-2,4-decadienal in FF15 induced its higher deep-fried odor.The FF27 had higher hexanoic acid(sweaty odor),heptanoic acid,nonanoic acid,benzene acetaldehyde(stale odor),and trans-4,5-epoxy-(E)-2-decenal(metallic odor)compared with FF4 and FF15,thus leading to the undesirable flavor of FF27.Moreover,the decrease of 2,5-dimethylpyrazine and 2-ethyl-6-methyl-pyrazine in FF27 induced the lower roasty flavor,which may also lead to the decline of the sensory score.Similarly,the higher contents of(E)-2-undecenal,hexanoic acid,heptanoic acid,and nonanoic acid in RO27 lead to increase its rancid score and thus lower the sensory score.

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

Studies on Silicon-Containing Fragrance Raw Materials( Ⅱ )——Syntheses and Odors of 4-Trimethylsilylcyclohex-3-enol and 4-Trimethylsilylcyclohexanol Derivatives

1-Substituted- 4-trimethylsilylcyclohex- 3-enol and 1-substituted- 4-trimetnylsilyl-cyclohexanol, 4-trimethylsilylcyclohex-3-enol and 4-trimethylsilylcyclohexanol, and some of their esters and carbon counterparts were synthesized. Structures of the nineteen new compounds were determined by 1H NMR, IR and MS. Their odors are evaluated.

Sustainable Recycling of Livestock Wastes by Composting and Environmentally Friendly Control of Wastewater and Odors

Excess amounts of livestock wastes are excreted in limited area and cause pollution problems in Japan.Comparative studies on livestock waste management among EU(European Union),US(the United States of America)and Asia including Japan are surveyed.In Japan,livestock wastes are mostly separated into solid and liquid matter.Solid matter is converted into organic fertilizer by means of composting.Composting should be developed into the technology that has low emission,high-quality and low cost.Various odorous compounds are emitted from the process of livestock waste management.Odor emission from livestock farms should be mitigated to protect the local community.High-quality compost can be widely distributed to cropland to decrease expenditure of chemical fertilizer.Although liquid matter,namely wastewater or slurry,could be applied to cropland of livestock farms such as EU countries,most of Japanese farms do not have enough cropland to use liquid matter.Particularly pig farms have no area to spread wastewater,which should be purified to clean water in accordance with the criteria of water quality and could be discharged into public water area.The most desirable management of livestock wastes should involve sustainable recycling as compost and environmentally friendly control of odors and wastewater.

20 ppm Anhydrous Ammonia Odor Agent Proposed for Hydrogen Fuel for Safe Detection of Leaks

Preferably 20 ppm anhydrous ammonia (NH3) is proposed to be added to hydrogen fuel (H) made from renewable energy sources (green hydrogen), so that H leaks may be easily detectable by smell, but not dangerously toxic. Including this odor agent, would allow H to be distributed safely in pipes, as required by law, and it would allow H to be safely stored, transported, and exported for sale, and widely commercialized. Further research is suggested to identify optimum pressure, temperature, and automated technique for injecting NH3 into H, and to chart the minimum concentration needed, as a function of temperature and humidity. An application to make hypersonic H burning aircraft safer for ground maintenance crews is proposed. An ability to make, store and distribute H, made from local sources of renewable energy, would reduce a need for fossil fuels, especially in poor, remote communities, where it could improve their economy by creating an export product for sale, while reducing pollution.

Spatiotemporal Neural Activity Changes in the Molluscan Olfactory Center Specifically Induced by Innately Aversive and <i>In Vitro</i>Aversively Conditioned Odors

In the procerebrum (PC), the olfactory center, of the land slug Limax, an oscillation of local field potential (LFP) with 0.5 - 1 Hz is observed by electrophysiological extracellular recording. The oscillation has a phase delay along the distal-proximal axis, resulting in the propagation of waves from the distal to proximal region. One important advantage of nervous systems of mollusks such as Limax is that their nervous systems in vitro retain several types of computational properties found in vivo (e.g. learning and memory). A previous study showed that the LFP frequency in the PC of Limax increased specifically in response to innately aversive and in vitro aversively conditioned odors. In the present study, we examined spatiotemporal neural activity changes induced in the PC by those odors using the fluorescent voltage imaging technique. The results showed that innately aversive (onion and hexanol) and in vitro aversively conditioned (carrot, which is innately attractive) odors specifically induced an increase in propagation speed of the neural activity in the PC, while innately attractive odors did not induce it. The results also suggested that the avoidance behavior by those odors might be induced by the increase of propagation speed and the following increases in the discharges of the partial nerve that transmits the motor output.

Study on the Antibacterial and Deodorization Effect of 4,4-Dichloro-2-Hydroxydiphenyl Ether in Laundry Gel Beads

In the formulation development of laundry gel beads,4,4-dichloro-2-hydroxydiphenyl ether(HP-100)was used as a bacteriostatic agent,and the effect of HP-100 dosage on the bacteriostatic rate of laundry gel bead samples with different formulation systems was examined by the suspension quantification method;the long-lasting bacteriostatic performance of laundry gel bead samples added with HP-100 was investigated by the absorption method for evaluating the antimicrobial performance of textiles;the effect of HP-100 on the odor control of laundry gel bead samples was investigated by filling out surveys and questionnaires using the actual measurement method.Questionnaire was used to investigate the effect of HP-100 on odor control.The test results showed that the antibacterial rate of the two laundry gel samples against S.aureus increased with the increase of HP-100 dosage,and the antibacterial rate of Formula 1 reached 99.9%when the dosage of HP-100 was 0.3%;the antibacterial rate of cotton cloth washed with the laundry gel sample of Formula 1+0.3%HP-100 was more than 50%after 24 h,and still had the antibacterial effect;the antibacterial rate of cotton cloth washed with the sample of laundry gel with HP-100 was more than 50%after 24 h,and still had the antibacterial effect;the antibacterial effect of the sample with HP-100 was more than 50%after 24 h,and still had the antibacterial effect.The fabrics washed with HP-100 added laundry gel beads had better odor control than those treated with laundry gel beads without HP-100,and the addition of HP-100 to laundry gel beads could have antibacterial and deodorizing effects.

土臭素对淡水鱼品质的影响及控制策略研究进展

水产品味道鲜美,营养丰富,是人类摄取食物蛋白的重要来源。但以土腥味为代表的特殊异味在淡水养殖的鱼类中经常出现,不但影响水产品的风味,更降低了消费者的消费意愿,制约着水产品养殖行业的稳定发展。而科学控制和预防水产品中的土腥味是保障水产品质量的重要手段,对满足产业需求具有重要意义,仍需深入研究。本文综述了水产品中以土腥味为典型代表的特殊异味,探讨了以土臭素为代表的异味物质在水产品中造成土腥味的机理,并结合目前控制土腥味的常用方法,对未来水产品异味防控发展趋势进行展望,以期消除水产品中的异味物质,尤其是淡水养殖的水产品中存在的土腥味。

豆浆豆腥味形成机理及其去除方法的研究进展

豆浆是一种营养价值丰富且能防治高血脂、高血压、动脉硬化、缺铁性贫血等疾病的理想植物蛋白饮料,经常食用可以增进和保护人体健康,甚至可以作为预防新冠的优质食品。但是大豆中天然存在的豆腥味降低了消费者的接受度,同时也限制了豆制品进一步的研发。本文针对能对豆浆豆腥味有贡献的挥发性化合物(醛类、醇类、呋喃类、酮类)及导致其形成的反应途径进行了系统的综述,并进一步阐述了豆腥味对豆浆开发的影响。随后从物理、化学、生物、遮蔽四个方面探讨了豆浆去腥工艺的发展现状,对当前豆腥味研究中存在的问题以及未来的研究方向做了归纳与展望,以期为开发低豆腥或无豆腥味豆制品及推动大豆类产品消费提供理论依据。

减少猪场臭气生成的饲粮配制技术与养殖技术研究进展

随着养殖规模和集约化程度的不断提高,养殖场产生的臭气严重危害人畜健康和周边生态环境,臭气污染问题备受关注。解决猪场臭气污染的重要途径之一是减少臭气物质产生,而改进饲粮技术和养殖技术是减少猪场臭气物质生成的关键技术措施。本文综述了猪场臭气组成及产生途径、猪场中关键致臭物质及筛选方法、有效减少臭气生成的饲粮技术和养殖技术,旨在为加强猪场臭气方面的基础研究及减排技术的推广提供参考,进一步推进养猪业的高质量发展。

我国城市水源水库水质风险成因及对策

我国城市水源中约40%为湖泊或水库,且大部分为水库,因此水源水库的水质状况对我国城市安全极其关键。本文综述了我国水源水库水质问题研究进展,分析了22个代表性水源水库的周年水质状况。结果发现,当前我国城市水源水库水质风险类型主要是异味问题、藻类水华、铁锰超标、有机质偏高、营养盐超标等。引发水源水库水质问题的主要原因包括流域开发强度过大、库底淤积及内源释放、生态系统结构失衡、气候与水文异常变化等。针对上述主要问题,提出了构建在线水质监测预警体系、控制流域土地开发强度、构建面源拦截及流域净化系统、疏浚底泥、优化生态系统结构、实施应急曝气与控藻工程、完善流域生态保护法律法规等多种水源水库水质安全保障技术措施。鉴于水源水库水质及水生态对暴雨、高温热浪等极端气象响应敏感而复杂,在当前极端天气事件频发、强度不断增加的气候背景下,还应加强水库生态学基础研究,以深入理解水源水库水质对气候变化的响应机制,提高水库水安全保障科技支撑能力,满足我国城市高质量发展的水资源需求。

橘汁发酵过程中柑橘香气及其贡献化合物的分析

柑橘香气是柑橘果酒重要香气属性之一。为研究柑橘果酒加工过程中柑橘香气形成及影响机制,采用固相萃取法和正向硅胶色谱法结合气相色谱嗅闻仪、气相色谱质谱仪和感官评价对柑橘香气及其贡献化合物和异味物质在橘汁发酵中的变化趋势进行分析。结果表明,从橘汁中共鉴定出29种关键香气物质,主要为果香气、柑橘香气、花香气、清香气和乳脂香气化合物,其中月桂烯、庚醛、柠檬烯、γ-松油烯、癸醇、辛醛、辛醇、香茅醇和橙花醇被鉴定为柑橘香气重要贡献化合物。在橘汁发酵前4 d,柑橘香气强度呈显著增加的趋势,随后显著减弱。Pearson相关性分析显示,柑橘香气强度的变化与柠檬烯、γ-松油烯、辛醇和橙花醇含量增减密切相关(P<0.05)。伴随着柑橘香气化合物含量降低,异丁酸、丁酸、2-甲基丁酸、戊酸、己酸、庚酸和辛酸等酸败刺激性气味物质含量显著增加,这些异味物质对柑橘香气的形成具有显著的遮盖作用。研究结果可为今后柑橘果酒工艺改进及香气品质提升提供一定的理论依据。

不同种类道路沥青材料异味特征及析源分析

随着我国社会经济逐渐向绿色可持续转型,沥青路面铺筑过程中的异味污染成为不可忽视的环境问题。本研究针对八种不同的道路沥青材料使用过程中产生的挥发性物质,通过气相色谱-质谱联用仪(GC-MS)和气体检测仪进行定性与定量分析。在此基础上,结合异味阈值计算各物质异味活度值(OAV),通过异味活度值加和(SOAV)的方法对沥青异味进行分析,并对异味污染物中各组分及其异味贡献进行进一步的析源工作。研究结果表明,沥青挥发物的浓度与异味活度值加和并没有完全的正相关关系,胶粉改性沥青挥发物浓度及异味活度值加和相较于其他沥青均有显著提高。对八种不同种类道路沥青材料异味特征进行分析得出:六种组分对沥青异味的产生有贡献,其中,苯系物、醛类以及硫化氢对沥青异味的贡献较大,烯烃类以及酮类是胶粉改性沥青挥发物中特有的异味贡献组分。

高锰酸钾氧化饮用水中醛类嗅味物质的效果及动力学研究

我国北方呼和浩特市以黄河为水源的JH饮用水厂近年来冬季经常有醛类嗅味物质检出,常规处理工艺如混凝、沉淀等对其去除效果有限,需要对其进行其它处理工艺的探究.本文选择高锰酸钾对水厂检出频率和浓度均较高的反,反-2,4-庚二烯醛(tt24hept)、反-2-辛烯醛(t2oa)、反,反-2,4-辛二烯醛(tt24oda)、反,反-2,4-癸二烯醛(tt24dda)和β-环柠檬醛(β-cyclo)5种醛类嗅味物质进行氧化控制研究,探究其去除效果、氧化动力学和氧化机理.结果表明,20℃,pH=7时,2 mg·L^(-1)高锰酸钾氧化5种醛类嗅味物质30 min后,去除率达75%以上.根据动力学分析可知,高锰酸钾氧化5种醛类嗅味物质属于伪二级动力学过程,其伪二级反应速率常数分别为5.25×10^(4)、2.66×10^(4)、4.50×10^(4)、2.71×10^(4)、5.37×10^(3)L·mol^(-1)·min^(-1),醛类嗅味物质结构中含碳碳双键数目越多、含亚甲基数目越少,反应速率常数越大.同时,氧化过程会产生新生态二氧化锰,促进高锰酸钾对嗅味物质的控制效果.最后,通过水厂原水加标实验效果验证,理论反应方程可为饮用水厂应对醛类物质嗅味问题提供相应的理论依据并指导生产.

橄榄果实表型性状分级及挥发性化合物鉴定与特征香气分析

对59个品种(系)橄榄果实表型性状(单果质量、纵径、横径、果形指数)进行测定分析和概率分级,筛选果形指数级别不同且遗传背景不同的15个品种(系)橄榄果实,采用顶空固相微萃取和气相色谱-质谱联用技术进行挥发性化合物的分离鉴定。结果表明:4个表型性状的变异丰富,变异系数范围为10.70%~26.67%;经K-S检验,果形指数、纵径、横径符合正态分布,并对这3个表型性状进行概率分级;橄榄果实中共鉴定到886种挥发性化合物,包括萜类186种、杂环类157种、酯类146种、酮类73种、烃类64种、醇类64种、醛类53种、芳烃51种、酸类21种、胺类21种、酚类20种、其他30种,含量1881.70~6727.40μg/g(以鲜质量计,下同);萜类为主要的挥发性化合物,相对含量52.49%,含量最高的为α-蒎烯(309.66μg/g),相对含量7.13%;香气活性值(odor activity value,OAV)分析表明,对橄榄具有香气贡献的特征香气成分为181种,贡献最高的为杂环化合物5-乙基-3-羟基-4-甲基-2(5H)-呋喃酮,OAV为2468148.28,呈甜香型;进一步通过主成分分析结合正交偏最小二乘判别分析,筛选到不同品种(系)橄榄果实的差异特征香气成分6种,变量投影重要性值最高的是α-法呢烯,OAV为19.71,香气类型花果香。研究结果可为橄榄果实品质质量分级提供依据,也为深入研究橄榄果实香气形成机制、果实品质改善提供了参考依据。

Co-IP联合质谱分析筛选中华蜜蜂气味受体OR1和OR2的互作蛋白

【目的】中华蜜蜂(Apis cerana cerana)是我国特有的蜜蜂品种,其高度灵敏的嗅觉系统能在复杂气味环境中识别群体内化学信号以及区分食物源散发的特异性气味分子,气味受体(Odorant receptors,ORs)在中蜂识别气味分子的行为过程中起到了重要而又关键的作用。通过分析筛选OR1和OR2的互作蛋白,为深入探究OR1和OR2蛋白在蜜蜂嗅觉系统中的功能提供理论依据。【方法】通过构建OR1和OR2基因的真核表达载体pFastBac-OR1和pFastBac-OR2载体,转染Sf9细胞,提取细胞总蛋白,利用免疫共沉淀(Co-IP)联合质谱分析技术筛选鉴定与OR1和OR2互作的细胞蛋白,并对这些互作蛋白进行GO功能注释、KEGG信号通路和蛋白互作网络分析。【结果】IP组和IgG组重组蛋白在细胞内得到正确表达,利用Co-IP联合质谱分析技术共筛选到273个与OR1互作的细胞蛋白和204个与OR2互作的细胞蛋白,主要为微管蛋白、热休克蛋白、核糖体蛋白等。对这些蛋白进行GO功能富积分析,发现这些蛋白质涉及多种生物学功能,包括RNA剪接、核糖体和能量运输有关。KEGG信号通路分析结果表明互作蛋白参与调节了多条细胞内的重要通路,包括核糖体、剪接体、RNA转运等与核糖体相关的通路,丙酮酸代谢、硫胺素新陈代谢、脂肪酸生物合成、淀粉和蔗糖代谢、FoxO信号通路,Hedgehog信号通路等。【结论】OR1和OR2可能通过与多种蛋白直接或间接的相互作用调控并影响其嗅觉感受。