Enantioselective sensing of insect pheromones in water.

An arrayed combination of water-soluble deep cavitands and cationic dyes has been shown to optically sense insect pheromones at micromolar concentration in water. Machine learning approaches were used to optimize the most effective array components, which allows differentiation between small structural differences in targets, including between different diastereomers, even though the pheromones have no innate chromophore. When combined with chiral additives, enantiodiscrimination is possible, dependent on the size and shape of the pheromone.

Re-Analysis of Abdominal Gland Volatilome Secretions of the African Weaver Ant, Oecophylla longinoda (Hymenoptera: Formicidae).

The African weaver ant, Oecophylla longinoda, is used as a biological control agent for the management of pests. The ant has several exocrine glands in the abdomen, including Dufour's, poison, rectal, and sternal glands, which are associated with pheromone secretions for intra-specific communication. Previous studies have analyzed the gland secretions of Dufour's and poison glands. The chemistry of the rectal and sternal glands is unknown. We re-analyzed the secretions from Dufour's and poison glands plus the rectal and sternal glands to compare their chemistries and identify additional components. We used the solid-phase microextraction (SPME) technique to collect gland headspace volatiles and solvent extraction for the secretions. Coupled gas chromatography-mass spectrometry (GC-MS) analysis detected a total of 78 components, of which 62 were being reported for the first time. These additional components included 32 hydrocarbons, 12 carboxylic acids, 5 aldehydes, 3 alcohols, 2 ketones, 4 terpenes, 3 sterols, and 1 benzenoid. The chemistry of Dufour's and poison glands showed a strong overlap and was distinct from that of the rectal and sternal glands. The different gland mixtures may contribute to the different physiological and behavioral functions in this ant species.

Profile of Terpenoid Compounds Mediating a Plant-Herbivore Interaction: Screening by Static Headspace Solid-Phase Microextraction-Gas Chromatography/Q-ToF Mass Spectrometry.

Conotrachelus dimidiatus (Coleoptera: Curculionidae) interacts with immature guava fruits (Psidium guajava L.) for feed, sleep, mate and oviposit. Determination of the volatile organic compounds (VOCs) emitted by the insect and immature fruits can help improve understanding of plant-insect and intraspecific insect interactions between females and males of C. dimidiatus. Daytime fruit setting emissions of immature guava consist mainly of limonene, caryophyllene, and aromadendrene. In addition to the host's volatiles, the aim of this study was to assess the VOCs released by the insect. Static headspace-solid phase microextraction (SHS-SPME), combined with gas chromatography/quadrupole time of flight mass spectrometry (GC/Q-ToF-MS), allowed the identification of the C10 terpenoids: grandlure I, II, II, IV, grandisoic acid, papayanol and papayanal bioactive compounds released by female and male C. dimidiatus under laboratory conditions. These chemical compounds are candidates for the preparation of a lure formulation.

Responses of the putative trachoma vector, Musca sorbens, to volatile semiochemicals from human faeces.

The putative vector of trachoma, Musca sorbens, prefers to lay its eggs on human faeces on the ground. This study sought to determine whether M. sorbens females were attracted to volatile odours from human faeces in preference to odours from the faeces of other animals, and to determine whether specific volatile semiochemicals mediate selection of the faeces. Traps baited with the faeces of humans and local domestic animals were used to catch flies at two trachoma-endemic locations in The Gambia and one in Ethiopia. At all locations, traps baited with faeces caught more female M. sorbens than control traps baited with soil, and human faeces was the most successful bait compared with soil (mean rate ratios 44.40, 61.40, 10.50 [P<0.001]; 8.17 for child faeces [P = 0.004]). Odours from human faeces were sampled by air entrainment, then extracts of the volatiles were tested by coupled gas chromatography-electroantennography with laboratory-reared female M. sorbens. Twelve compounds were electrophysiologically active and tentatively identified by coupled mass spectrometry-gas chromatography, these included cresol, indole, 2-methylpropanoic acid, butanoic acid, pentanoic acid and hexanoic acid. It is possible that some of these volatiles govern the strong attraction of M. sorbens flies to human faeces. If so, a synthetic blend of these chemicals, at the correct ratios, may prove to be a highly attractive lure. This could be used in odour-baited traps for monitoring or control of this species in trachoma-endemic regions.

Isolation of anti-algal substances from Cylindrotheca closterium and their inhibition activity on bloom-forming Prorocentrum donghaiense.

This paper studied the allelopathic effect of Cylindrotheca closterium on the growth of Prorocentrum donghaiense, the model of harmful algal blooms in aquatic environment, by the co-culture tests and bioassay-guided fraction methods. The growth of P. donghaiense in co-cultures was observably suppressed by C. closterium, and P. donghaiense biomass in C/P = 3: 1 group increased slowly with a low growth rate of 0.18 d-1 after 4 days. Petroleum ether (PE) extract derived from C. closterium filtrates was isolated by C18 column and the allelopathy of all isolated fractions for P. donghaiense was investigated. After 96 h cultivation, the inhibition ratio of PE-Ⅲ and PE-Ⅷ fractions on P. donghaiense could reach up to 70.2% and 64.3% at the concentration of 10-fold when compared to control, while the other fractions displayed relatively low inhibitory effects on P. donghaiense. PE-Ⅲ and PE-Ⅷ fractions also decreased the chlorophyll content and maximum quantum yield of photosystem II (Fv/Fm) of P. donghaiense cells. The activities of superoxide dismutase (SOD), one of antioxidant enzymes, reduced around 8.3% and 13.7% following exposure to 2-fold PE-Ⅲ and PE-Ⅷ, and was significantly decreased following higher exposure concentrations. After 96 h of 10-fold PE-Ⅲ and PE-Ⅷ treatments, Catalase (CAT) activity reduced to 44.86% and 46.42% of that observed in the control group. At the same time, a significant increase in malondialdehyde (MDA) contents was observed. These findings suggested that PE-Ⅲ and PE-Ⅷ fractions contained main allelochemicals and possibly acted as promising algistatic agents for emergency handling of P. donghaiense blooms.

Waterborne pheromones modulate gonadotropin-inhibitory hormone levels in sea lamprey (Petromyzon marinus).

The relationships between pheromone stimuli and neuropeptides are not well established in vertebrates due to the limited number of unequivocally identified pheromone molecules. The sea lamprey (Petromyzon marinus) is an advantageous vertebrate model to study the effects of pheromone exposure on neuropeptides since many pheromone molecules and neuropeptides have been identified in this species. Sexually mature male sea lamprey release pheromones 7α, 12α, 24-trihydroxy-5α-cholan-3-one 24-sulfate (3 keto-petromyzonol sulfate, 3kPZS) and 7α, 12α-dihydroxy-5α-cholan-3-one-24-oic acid (3-keto allocholic acid, 3kACA) that differentially regulate gonadotropin-releasing hormone (lGnRH) and steroid levels in sexually immature sea lamprey. However, the effects of these pheromones on gonadotropin-inhibitory hormones (GnIHs), hypothalamic neuropeptides that regulate lGnRH release, are still elusive. In this report, we sought to examine the effects of waterborne pheromones on lamprey GnIH-related neuropeptide levels in sexually immature sea lamprey. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analyses revealed sex differences in GnIH-related neuropeptide levels in the brain and plasma of immature sea lamprey. Exposure to 3kPZS and 3kACA exerted differential effects on GnIH-related neuropeptide levels in both sexes, but the effects were more prominent in female brains. We conclude that sea lamprey pheromones regulate GnIH-related neuropeptide levels in a sexually dimorphic manner.

Pheromone Composition and Chemical Ecology of Six Species of Cerambycid Beetles in the Subfamily Lamiinae.

Cerambycid beetles of the subfamily Lamiinae use male-produced aggregation-sex pheromones that are attractive to both sexes. Terpenoid pheromones have been identified from species in the tribes Acanthoderini and Acanthocinini native to North and South America, comprised of (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone), the structurally related 6-methylhept-5-en-2-one (sulcatone), and/or specific enantiomers or nonracemic ratios of enantiomers of the related compounds (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol), its acetate ester, (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), and 6-methylhept-5-en-2-ol (sulcatol). Here, we present new information about the chemical ecology of six acanthoderine and acanthocinine species native to the eastern USA. The pheromone of Astyleiopus variegatus (Haldeman) previously was identified as a blend of (S)-fuscumol and (S)-fuscumol acetate, and we report here that geranylacetone is a synergistic component. Males of Aegomorphus modestus (Gyllenhal), Lepturges angulatus (LeConte), and Lepturges confluens (Haldeman) were found to produce similar blends composed of the enantiomers of fuscumol acetate and geranylacetone, whereas males of Astylidius parvus (LeConte) and Sternidius alpha (Say) produced both enantiomers of fuscumol together with (R)-fuscumol acetate and geranylacetone. Field experiments with synthesized chemicals revealed that species with similar pheromone composition nevertheless differed in their responses to individual components, and to various blends of components, and in how attraction was influenced by chemicals that were pheromone components of other species. Sulcatone and/or sulcatol antagonized attraction of some species to pheromones of the geranylacetone class, suggesting that there is an adaptive advantage in an ability to detect these heterospecific compounds, such as in avoiding cross attraction to other cerambycid species, as yet unknown, that use pheromones composed of both chemical classes.

Knowing Me, Knowing You: Anal Gland Secretion of European Badgers (Meles meles) Codes for Individuality, Sex and Social Group Membership.

European badgers, Meles meles, are group-living in the UK, and demarcate their ranges with shared latrines. As carnivores, badgers possess paired anal glands, but olfactory information on the content of badger anal gland secretion (AGS) is largely uninvestigated. Here, we examined the volatile organic compounds (VOCs) of AGS samples from 57 free-living badgers using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry. AGS was rich in alkanes (C7-C15, 14.3% of identified compounds), aldehydes (C5-C14, 9.7%), phenols (C6-C15, 9.5%), alcohols (C5-C10, 7.3%), aromatic hydrocarbons (C6-C13, 6.8%), ketones (C6-C13, 6.3%) and carboxylic acids (C3-C12, 5.6%) and contained a variety of esters, sulfurous and nitrogenous compounds, and ethers. The number of VOCs per profile ranged from 20 to 111 (mean = 65.4; ± 22.7 SD), but no compound was unique for any of the biological categories. After normalization of the raw data using Probabilistic Quotient Normalization, we produced a resemblance matrix by calculating the Euclidian distances between all sample pairs. PERMANOVA revealed that AGS composition differs between social groups, and concentration and complexity in terms of number of measurable VOCs varies between seasons and years. AGS VOC profiles encode individual identity, sex and vary with female reproductive state, indicating an important function in intraspecific communication. Because AGS is excreted together with fecal deposits, we conclude that chemical complexity of AGS enables particularly latrine-using species, such as badgers, to advertise more complex individual-specific information than in feces alone.

Proteomic Analysis Reveals Allergen Variability among Breeds of the Dust Mite Blomia tropicalis.

BACKGROUND: The dawn of the "omics" technologies has changed allergy research, increasing the knowledge and identification of new allergens. However, these studies have been almost restricted to Dermatophagoides spp. Although Blomia tropicalis has long been established as a clinically important source of allergens, a thorough proteomic characterization is still lacking for this dust mite. OBJECTIVE: To increase knowledge of B. tropicalis allergens through proteomic analysis. METHODS: Eleven in-bred lineages of B. tropicalis were obtained from 11 unique different pregnant females. Their somatic extracts were analyzed and compared with a commercially available extract by liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: Considerable differences in the protein expression profiles were found among the breeds, and most of them displayed higher expression levels of major allergens than the commercially available extract. Blo t 2 was the most prominent allergenic protein in the analyzed extracts. Six identified allergens and 14 isoforms have not yet been recognized by IUIS. Conversely, 3 previously recognized B. tropicalis allergens were not found. CONCLUSIONS: The clear impact of inbreeding on allergen content shown by our study leads us to conclude that the quantification and/or identification of allergens from in-bred lines should be routinely considered for mite cultivation in order to select breeds with higher amounts of major allergens. In this sense, LC-MS/MS may be a useful method to achieve this quality control for research and commercial purposes.

Identification and Allelopathy of Green Garlic (Allium sativum L.) Volatiles on Scavenging of Cucumber (Cucumis sativus L.) Reactive Oxygen Species.

Garlic and formulations containing allicin are used widely as fungicides in modern agriculture. However, limited reports are available on the allelopathic mechanism of green garlic volatile organic compounds (VOCs) and its component allelochemicals. The aim of this study was to investigate VOCs of green garlic and their effect on scavenging of reactive oxygen species (ROS) in cucumber. In this study, green garlic VOCs were collected by HS-SPME, then analyzed by GS-MS. Their biological activity were verified by bioassays. The results showed that diallyl disulfide (DADS) is the main allelochemical of green garlic VOCs and the DADS content released from green garlic is approximately 0.08 mg/g. On this basis, the allelopathic effects of green garlic VOCs in vivo and 1 mmol/L DADS on scavenging of ROS in cucumber seedlings were further studied. Green garlic VOCs and DADS both reduce superoxide anion and increase the accumulation of hydrogen peroxide of cucumber seedlings. They can also regulate active antioxidant enzymes (SOD, CAT, POD), antioxidant substances (MDA, GSH and ASA) and genes (CscAPX, CsGPX, CsMDAR, CsSOD, CsCAT, CsPOD) responding to oxidative stress in cucumber seedlings.

Identification of a novel plant-derived attractant for Acromyrmex lobicornis leaf-cutting ants.

Leaf-cutting ants are considered major pests of agriculture and forestry in the Neotropics. Attractive toxic baits are the prevailing method for managing them. Thus, there is great interest in identifying attractants to incorporate into these baits. Moreover, leaf-cutting ants can avoid toxic baits by associating the attractant with the toxin. We evaluated attractiveness of heptyl butyrate, a volatile compound found in fresh apples and plums. We conducted field experiments with ten colonies of Acromyrmex lobicornis. First, we evaluated the behaviour of ants exposed to heptyl butyrate at 1% by surrounding resources. Then, we compared the attractiveness of heptyl butyrate and orange pulp, the most commonly used attractant. Finally, we evaluated whether heptyl butyrate increases the attractiveness of a carbohydrate resource at varying doses. Heptyl butyrate at 1% attracted 92% more ants than the control and that it was as attractive as orange pulp. Heptyl butyrate paired with sucrose at concentrations of 0.001 and 0.1% was more attractive than sucrose alone, but greater concentrations did not increase sucrose's attractiveness. Therefore, heptyl butyrate could be added to toxic baits to manage A. lobicornis as it is as attractive as the most commonly used attractant and can be applied directly to the pellets.

Isopentyl Butanoate: Aggregation Pheromone of the Brown Spiny Bug, Clavigralla tomentosicollis (Hemiptera: Coreidae), and Kairomone for the Egg Parasitoid Gryon sp. (Hymenoptera: Scelionidae).

The brown spiny bug, Clavigralla tomentosicollis Stål (Hemiptera: Coreidae) is a key pest of leguminous crops in many countries in Africa, causing significant yield losses especially in cowpea, pigeon pea and common beans. Although C. tomentosicollis uses olfaction to aggregate, little is known about the identity of the aggregation pheromone. This study aimed to identify the aggregation pheromone of C. tomentosicollis and to test its potential role in the behavior of its egg parasitoid, Gryon sp. In Y-tube olfactometer bioassays, only male volatiles strongly attracted both sexes of C. tomentosicollis. Coupled gas chromatography/electroantennographic detection (GC/EAD) and GC/mass spectrometry were used to identify antennally-active compounds from male volatiles. Antennae of both sexes detected identical components including a male-specific component, identified as isopentyl butanoate, which was also detected by antenna of the egg parasitoid. In olfactometer bioassays, both sexes of C. tomentosicollis and the egg parasitoid responded to isopentyl butanoate. These results suggest that isopentyl butanoate serves as an aggregation pheromone for both sexes of C. tomentosicollis and a useful kairomone to attract the parasitoid in the management of C. tomentosicollis.

O Complexo Regulador em Saúde do Distrito Federal, Brasil, e o desafio da integração entre os níveis assistenciais / The Regulatory Complex for Health Care in the Federal District, Brazil and the challenge for integrating levels of health care

Resumo A integração entre os níveis de atenção é um desafio contínuo mesmo em sistemas de saúde consolidados e de alta performance. A reestruturação do sistema público de saúde do Distrito Federal, baseado no fortalecimento da Atenção Primária à Saúde (APS), na reconfiguração da atenção especializada (ambulatorial e hospitalar) e de sua rede de urgência e emergência, trouxe como desafio a necessidade de integração entre esses níveis. Fez-se necessária a criação de um dispositivo que desempenhasse o papel de "gatekeeper" conduzindo o acesso equânime, transparente e seguro para a atenção especializada e hospitalar. Neste sentido, foi estruturado o Complexo Regulador em Saúde do Distrito Federal (CRDF) e suas Centrais de Regulação (CR), orientados para a execução de um processo regulatório de acesso para os serviços de internação hospitalar, ambulatorial (procedimentos e consultas especializadas), cirurgias eletivas, alta complexidade, transporte sanitário, urgências e transplantes de pacientes do Distrito Federal e de fora dele. Este artigo descreve o processo de implantação e de implementação do CRDF e de suas CR, de forma a refletir sobre as potencialidades e desafios de seu papel enquanto instrumento de integração entre os níveis assistenciais de saúde.

Abstract The integration among levels of care is a continuous challenge even in consolidated and high performance health systems. The reform of public health system of Distrito Federal, based on the strengthening of primary health care associated to the reconfiguration of specialized attention (ambulatory and hospital) and of its of urgency and emergence network brought, as a challenge, the need for integration between these levels. Thus, became necessary to create an instrumentto perform the role of gatekeeper, leading to equanimous, transparent and safe access to specialized and hospital care. Thus, the Regulatory Complex in Health of Distrito Federal (CRDF) and its Regulatory Centers (CR) were created to carry out the regulatory process of access to care services, such as hospitalization, ambulatory care (procedures and specialized consultations), elective surgeries, complex procedures, sanitary transport, urgencies and transplants of patients of the Federal District and outside it. This article describes the process of the CRDF implementation and its CRs, aiming to reflect on the potential and challenges of its role as an instrument of integration among the levels of care.

5α-cyprinol sulfate, a bile salt from fish, induces diel vertical migration in Daphnia.

Prey are under selection to minimize predation losses. In aquatic environments, many prey use chemical cues released by predators, which initiate predator avoidance. A prominent example of behavioral predator-avoidance constitutes diel vertical migration (DVM) in the freshwater microcrustacean Daphnia spp., which is induced by chemical cues (kairomones) released by planktivorous fish. In a bioassay-guided approach using liquid chromatography and mass spectrometry, we identified the kairomone from fish incubation water as 5α-cyprinol sulfate inducing DVM in Daphnia at picomolar concentrations. The role of 5α-cyprinol sulfate in lipid digestion in fish explains why from an evolutionary perspective fish has not stopped releasing 5α-cyprinol sulfate despite the disadvantages for the releaser. The identification of the DVM-inducing kairomone enables investigating its spatial and temporal distribution and the underlying molecular mechanism of its perception. Furthermore, it allows to test if fish-mediated inducible defenses in other aquatic invertebrates are triggered by the same compound.

Identification and Synthesis of Luteolide, a Highly Branched Macrolide Semiochemical from the Mantellid Frog Gephyromantis luteus.

Luteolide is a 10-membered aliphatic macrolactone, (4 R,8 S,9 S)-4,8-dimethylundecan-9-olide ((-) -17), released by the femoral gland of males of the mantellid frog Gephyromantis luteus. Its structure was established using NMR, MS, and chiral GC and confirmed by stereoselective synthesis of different stereoisomers. Among the approximately 20 current macrolides known from the Mantellidae, luteolide is the first example of a volatile macrolide furnishing three stereogenic centers and an ethyl side chain.

Identification of a non-host semiochemical from tick-resistant donkeys (Equus asinus) against Amblyomma sculptum ticks.

Amblyomma sculptum is a tick affecting animal and human health across Argentina, Bolivia, Paraguay and Brazil. Donkeys, Equus asinus, are known to be resistant to A. sculptum, suggesting that they can produce non-host tick semiochemicals (allomones), as already demonstrated for some other vertebrate host/pest interactions, whereas horses, Equus caballus, are considered as susceptible hosts. In this study, we tested the hypothesis that donkeys produce natural repellents against A. sculptum, by collecting sebum from donkeys and horses, collecting the odour from sebum extracts, and identifying donkey-specific volatile compounds by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS). From the complex collected blends, five main compounds were identified in both species. Hexanal, heptanal and (E)-2-decenal were found predominantly in donkey extracts, whilst ethyl octanoate and ethyl decanoate were found predominantly in horse extracts. One compound, (E)-2-octenal, was detected exclusively in donkey extracts. In Y-tube olfactometer bioassays 36 different A. sculptum nymphs were tested for each extract, compound and concentration. The dry sebum extracts and the compounds identified in both species induced neither attraction nor repellency. Only (E)-2-octenal, the donkey-specific compound, displayed repellency, with more nymphs preferring the arm containing the solvent control when the compound was presented in the test arm across four concentrations tested (p < 0.05, Chi-square test). A combination of a tick attractant (ammonia) and (E)-2-octenal at 0.25 M also resulted in preference for the control arm (p < 0.05, Chi-square test). The use of semiochemicals (allomones) identified from less-preferred hosts in tick management has been successful for repelling brown dog ticks, Rhipicephalus sanguineus sensu lato from dog hosts. These results indicate that (E)-2-octenal could be used similarly to interfere in tick host location and be developed for use in reducing A. sculptum numbers on animal and human hosts.

Isophorone derivatives as a new structural motif of aggregation pheromones in Curculionidae.

The beetle Homalinotus depressus (Coleoptera: Curculionidae) is a major pest of coconuts in the Northern region of Brazil, for which environmentally friendly methods of control are desired. Behavioral responses of H. depressus to airborne volatile extracts from conspecifics suggested the presence of a male-produced aggregation pheromone. GC analyses of these extracts showed the presence of four male-specific compounds. Analytical data in combination with the synthesis of standards led to the identification of the male-released semiochemicals as epoxyisophorone (1), isophorone (2), homalinol (3), and 2-hydroxyisophorone (4), of which (3) was the major constituent. The configuration of homalinol was determined to be cis on the basis of retention times of synthetic cis and trans synthetic standards. Enantiomers of cis-homalinol were obtained in high enantiomeric excess by using biocatalysis. Their separation on a GC enantioselective column (ß-Dex325®), allowed us to unambiguously determine that the absolute configuration of natural homalinol was (1R,2R,6S). Field bioassays demonstrated that both the synthetic major compound per se and mixtures of all four male-specific compounds were attractive to H. depressus.

Allelopathic effects of harmful algal extracts and exudates on biofilms on leaves of Vallisneria natans.

This study investigated the allelopathic effects of Microcystis aeruginosa (M. aeruginosa) extracts and exudates on the physiological responses, photosynthetic activity, and microbial structure of biofilms on leaves of Vallisneria natans (V. natans). By measuring physiological and photosynthetic indices, the results showed that M. aeruginosa allelochemicals inhibited photosynthesis, oxidative stress and antioxidant system stress response in the biofilms of V. natans leaves. Multifractal analysis found that the surface topography of V. natans leaves was altered due to the allelochemicals found in M. aeruginosa. Microbial diversity on the leaves was analyzed using high-throughput sequencing, and the results showed that M. aeruginosa exudates had a stronger effects on the microbial community structure of biofilms compared to extracts. These findings highlight how cyanobacterial allelochemicals induce negative effects on submerged macrophytes.

Implementing solid phase microextraction (SPME) as a tool to detect volatile compounds produced by giant pandas in the environment.

Chemical cues are thought to play an important role in mate identification in the solitary giant panda (Ailuropoda melanoleuca). The goal of this study was to detect and identify volatile compounds present in the enclosure air of captive giant pandas. We hypothesized that a subset of compounds produced from breeding animals would be detected in environmental samples because highly volatile chemicals are likely to facilitate mate detection. Samples were collected from the enclosures of 8 giant pandas (n = 4 male, n = 4 female) during the Mar-June breeding season and the Aug-Jan non-breeding period from 2012-2015. Volatile compounds were captured by securing a solid phase micro extraction fiber approximately 3 meters above the ground within a panda enclosure for 6-12 hours. Compounds adsorbed onto the SPME fibers were analyzed by gas chromatography mass spectrometry. Thirty-three compounds were detected in at least 10% of all samples within individual and season and across all subjects within each season. Aromatic compounds made up 27.3% of the enclosure volatile profile, while 21.2% was made of cyclic aliphatic compounds and 51.5% of the enclosure profile was comprised of acyclic aliphatic compounds. Three compounds were likely to be present in male enclosures regardless of season, while Undecane, 4-methyl had a significant (p<0.05) predicted probability of being present in female enclosures. 3,3'-(1,1-Ethanediyl)bis(1H-indole) had a significant (p<0.05) probability of occurrence in male enclosures during the breeding season. Given the prevalence of these compounds, we suspect that these chemicals are important in giant panda communication. This novel sampling technique can detect volatile compounds produced by captive species and also may be a useful tool for detecting pheromones in free-ranging individuals.

The stresses of allelochemicals isolated from culture solution of diatom Phaeodactylum tricornutum Bohlin on growth and physiology of two marine algae.

The allelopathic effects of extracts isolated from the culture filtrate of diatom Phaeodactylum triconutum Bohlin on typical marine microalgae Prorocentrum donghaiense Lu and Dunaliella salina Teodoresco were investigated by determining different physiological and biochemical parameters, such as growth rate, membrane systems and esterase activity under controlled laboratory conditions. The growth of P. donghaiense was significantly inhibited immediately after exposure to the allelochemicals, while the algae density of D. salina was less sensitive. Chlorophyll-a content, membrane systems, as well as esterase activity were simultaneously investigated by flow cytometry with particular fluorescent markers and exhibited changeable sensitivities. The results demonstrated that the membrane systems of P. donghaiense were suppressed by the allelochemicals directly, causing loss of integrity and membrane penetration. Esterase activity was the most sensitive indicator as that of P. donghaiense cells significantly increased in short time and was inhibited subsequently. However, the membrane of D. salina remained intact still after exposure to the extracts and the esterase activity was only inhibited on last day during experiment period. Membrane potential and chlorophyll-a content of the two marine algae also showed somewhat different changes, as that of P. donghaiense cells were impaired after 5 day exposure to all volume conditions while these two characteristics of D. salina was only suppressed by exposure to high volume of the allelochemicals on day 6. The present results indicated that the inhibition of culture filtrate of P. triconutum on P. donghaiense was algicidal whereas the effect on D. salina appeared to be algistatic.