Influence of MHC on sibling discrimination in Arctic char,Salvelinus alpinus (L.)

The preference of juvenile Arctic char [Salvelinus alpinus (L.)] for odors from siblings and nonsiblings with different major histocompability complex class II (MHC) genotypes was studied in two-choice fluviarium tests. In the first part of the study, test fish demonstrated no preference for water scented by a sibling with a MHC genotype different from its own versus water scented by a MHC identical nonsibling. When both donors were siblings with different MHC genotypes, however, the test fish chose the water scented by the fish with the same MHC type as the test fish. The results suggest that odors with information about kinship are dependent on MHC but also on other, unknown factors. In the second part of the study, we observed that fish isolated since fertilization did not show any behavioral discrimination towards siblings, based on MHC genotype. One reasonable explanation for this result is that Arctic char learn to discriminate between odors from individuals of different MHC types.     

Analysis of characteristic human female axillary odors: Qualitative comparison to males

Odors produced in the human female axillae are of both biological and commercial importance. Several studies have suggested that extracts from female underarm secretions can alter the length and timing of the female menstrual cycle. In addition, more than 1.6 billion dollars are spent annually on products to eliminate or mask the axillary odors. Our recent studies have determined that the characteristic axillary odors in males consist of C₆–C₁₁, saturated, unsaturated and branched acids, with (E)-3-methyl-2-hexenoic acid (3M2H) being the major compound in this mixture. The 3M2H appears to be carried to the skin surface bound to two proteins in the axillary secretions. Data reported here show that the same mixture of odorous compounds is found in female axillary secretions, with several minor qualitative differences. Separation of the female apocrine secretions into aqueous and organic soluble fractions demonstrated that 3M2H, and several other members of the acids in the characteristic odor, are released by hydrolysis with base. Electrophoretic separation of the proteins found in the aqueous phase of female apocrine secretions revealed a pattern identical to that seen in males. The qualitative similarity of the acidic constituents making up the characteristic axillary odors of both females and males as well as the proteins present in the aqueous phase suggest a similar origin for axillary odors in both sexes.     

An investigation of human apocrine gland secretion for axillary odor precursors

Recently completed studies from our laboratories have demonstrated that the characteristic human male axillary odors consist of C₆ to C₁₁ normal, branched, and unsaturated aliphatic acids, with (E)-3-methyl-2-hexenoic acid being the most abundant. To investigate the mechanism by which the odor is formed, it is necessary to determine the nature of the odorless precursor(s) found in the apocrine secretion which is converted by the cutaneous microorganisms to the characteristic axillary odor. Pooled apocrine secretion was obtained from several male volunteers by intracutaneous injection of epinephrine. Partitioning this secretion into aqueous and organic soluble fractions was followed by hydrolysis of each fraction with NaOH or incubation with axillary microorganisms (cutaneous lipophilic corynebacterium). Analysis by gas chromatography/mass spectrometry (GC/MS) revealed the presence of (E)- and (Z)-3-methyl-2-hexenoic acid in the aqueous phase hydrolysate and aqueous phase incubated with bacteria; however, only a trace amount was seen in the resultant organic phase mixtures. These results suggest that a water-soluble precursor(s) is converted by the axillary flora to the characteristic axillary odors.     

Analysis of characteristic odors from human male axillae

A number of studies concerning the analysis of axillary odors have assumed that the characteristic odor produced in the axillae is due to volatile steroids and isovaleric acid. Organoleptic evaluation of Chromatographic eluants from axillary extracts was employed to isolate the region in the chromatogram where the characteristic odor eluted. The odor of the dissolved eluant was eliminated when it was treated with base, suggesting that acids make up the characteristic axillary odor. Subsequent extraction of the pH-adjusted axillary extract in conjunction with organoleptic evaluation of the Chromatographic eluant, preparative gas chromatography, and analysis by GC-MS as well as GC-FTIR showed the presence of a number of C₆ to C₁₁ straight-chain, branched, and unsaturated acids as important contributors to the axillary odor. The major odor component is (E)-3-methyl-2-hexenoic acid. Three homologous series of minor components are also important odor contributors; these consist of the terminally unsaturated acids, the 2-methyl-C₆ to -C₁₀ acids and the 4-ethyl-C₅ to -C₁₁ acids. These types of acids have not been reported previously as components of the human axillary secretions and have not been proposed previously as part of the principal odor components in this area.     

Infrared identification of carboxylic acids formed in polymer photooxidation

Several low molecular weight carboxylic acids with different substitutions were introduced into various polymer matrices: polypropylene, polystyrene, poly(butylene terephthalate), MDI-based polyurethane, and poly(vinyl chloride). These acids were then submitted to chemical treatments by sulfur tetrafluoride and ammonia. Derivatization reactions by SF₄ and NH₃ gave, respectively, acyl fluorides and carboxylate ions. The wavenumbers corresponding to the v?_c?o maxima of the carboxylic acids, acyl fluorides, and carboxylate ions were determined. For each one of these species, noticeable shifts were recorded that depended on the nature of the substitutents as well as on the nature of the polymer matrix. In addition, samples of the chosen polymers were exposed to photoaging. Photooxidized samples were reacted with SF₄ and NH₃. Their IR characteristics were determined before and after the treatments. Comparison with the results obtained with the molecular acids permitted us to specify the chemical structure of the acids formed by photooxidation and then to determine the oxidation sites on the macromolecular chains of the different polymers. © 1994 John Wiley & Sons, Inc.     

Lewis Acids as Highly Efficient Catalysts for the Decarboxylative Esterification of Carboxylic Acids with Dialkyl Dicarbonates

Mild Lewis acids such as Mg(ClO₄)₂ show a new level of catalytic activity for the decarboxylative esterification of carboxylic acids with commercially available dialkyl dicarbonates. In the presence of as little as one mol % Mg(ClO₄)₂ catalyst, carboxylic acids can thus easily and near quantitatively be protected at room temperature, e.g., as methyl, benzyl, or t‐butyl esters. Only volatile by‐products are released so that the purification of the products is particularly easy. Many sensitive functionalities are tolerated, including even phenol esters, or free hydroxy and BOC groups.     

Individual Discrimination by Odors in Sibling Prairie Voles (<Emphasis Type="Italic">Microtus ochrogaster</Emphasis>)

The habituation–discrimination paradigm has been used widely to demonstrate that animals can detect individually distinctive odors of unfamiliar conspecifics. By using a modification of the habituation–discrimination technique, Todrank et al. (Anim Behav 55:377–386, 1998) found that golden hamsters discriminate between the individual odors of their own familiar brothers but cannot discriminate between the odors of two siblings that are unrelated and unfamiliar to the subject. This suggested that previous evidence showing that animals could discriminate between the odors of individuals actually may have demonstrated the ability to discriminate between genetically unrelated conspecifics (i.e., members of different families). To test this possibility, we conducted habituation–discrimination experiments with prairie voles, Microtus ochrogaster. Voles were tested under three conditions: subject and both targets were unrelated and unfamiliar; subject and both targets were brothers and familiar; subject was unrelated and unfamiliar to targets, but targets were brothers. In all cases, voles discriminated between the two individual odors. Thus, prairie voles can discriminate individual differences between the odors of brothers and they do not have to have previous experience with the conspecifics in order for discrimination to occur. The theoretical importance of these results is discussed.     

Ultrasonication and microwave assisted extraction of degradation products from degradable polyolefin blends aged in soil

Two nonconventional extraction techniques, microwave assisted extraction (MAE) and ultrasonication, were used to extract degradation products from polyolefins with enhanced degradability. High‐density polyethylene/polypropylene blends with two different biodegradable additives (a granular starch/iron oxide mixture and Mater‐Bi AF05H) were subjected to outdoor soil burial tests and removed at different periods of time between 0 and 21 months. The extracted products were analyzed by gas chromatography mass spectrometry (GC‐MS). Ultrasonication was found to be a more suitable technique than MAE because of better reproducibility. In addition, higher amounts of certain products (e.g., carboxylic acids) were extracted by ultrasonication than by MAE. The degradation products extracted from the two blends were basically a homologous series of alkanes, alkenes, carboxylic acids, and alcohols. The amount of hydrocarbons (saturated and unsaturated) and alcohols remained basically the same as the degradation times increased. However, carboxylic acids tended to decrease slightly with the exposure time. Their concentration remained practically unchanged until 12 months of soil burial when a more significant decrease was noted. The quantitative analysis of the degradation products revealed for both samples a decrease in the amount of carboxylic acids with the exposure time, although the trend was different according to the additive used in each sample. For blends with Mater‐Bi the amount of carboxylic acids was at a minimum after 12‐month exposure in soil, which coincided with a minimum in the molecular weight distribution. After blends with granular starch/iron oxide were exposed to 3 months in soil, tetradecanoic acid was no longer detectable and the amount of hexadecanoic and octadecanoic acids decreased significantly. Solid‐phase microextraction, a solvent‐free extraction technique, was used to extract the degradation products that could have migrated to the soil from blends with Mater‐Bi. Small amounts of tetradecanoic acid and dodecanol were identified by GC‐MS in the soil surrounding the sample. The degradation patterns observed here correlate with our previous results from mechanical and morphological characterization of these samples. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1101–1112, 2001     

NMR based determination of minute acid functionality: end-groups in PET

Conditions are determined for the carbodiimide-mediated room temperature esterification of the carboxylic acid end-groups of poly(ethylene terephthalate) with hexafluoroisopropanol. The hexafluoroisopropyl ester is quantified with ¹⁹F NMR, using α,α,α-trifluorotoluene as a secondary standard. This provides a technique for accurate determination of minute amounts of carboxylic acid functionality in small samples of polymers, and potentially in animal and plant based foods.     

Chemical Synthesis of Rare Natural Bile Acids: 11α‐Hydroxy Derivatives of Lithocholic and Chenodeoxycholic Acids

A method for the preparation of 11α‐hydroxy derivatives of lithocholic and chenodeoxycholic acids, recently discovered to be natural bile acids, is described. The principal reactions involved were (1) elimination of the 12α‐mesyloxy group of the methyl esters of 3α‐acetate‐12α‐mesylate and 3α,7α‐diacetate‐12α‐mesylate derivatives of deoxycholic acid and cholic acid with potassium acetate/hexamethylphosphoramide; (2) simultaneous reduction/hydrolysis of the resulting △¹¹‐3α‐acetoxy and △¹¹‐3α,7α‐diacetoxy methyl esters with lithium aluminum hydride; (3) stereoselective 11α‐hydroxylation of the △¹¹‐3α,24‐diol and △¹¹‐3α,7α,24‐triol intermediates with B₂H₆/tetrahydrofuran (THF); and (4) selective oxidation at C‐24 of the resulting 3α,11α,24‐triol and 3α,7α,11α,24‐tetrol to the corresponding C‐24 carboxylic acids with NaClO₂ catalyzed by 2,2,6,6‐tetramethylpiperidine 1‐oxyl free radical (TEMPO) and NaClO. In summary, 3α,11α‐dihydroxy‐5β‐cholan‐24‐oic acid and 3α,7α,11α‐trihydroxy‐5β‐cholan‐24‐oic acid have been synthesized and their nuclear magnetic resonance (NMR) spectra characterized. These compounds are now available as reference standards to be used in biliary bile acid analysis.     

三辛胺萃取有机羧酸的机理(Ⅱ)──有机羧酸的pK_a值和亲油性的影响

在本文（Ⅰ）报研究的基础上,进一步考察了三辛胺──有机羧酸体系的红外光谱图．选用的有机羧酸为甲酸、丁酸、己酸和氯乙酸等．通过红外光谱分析定量求取了负载羧酸有机相的I值,讨论了有机羧酸的pK_a值和亲油性对不同形态萃合物组成比的影响．     

Surface migration of carboxylic acid in styrene–butadiene rubber and its tribological consequences

Surface migration of the carboxylic acids (C₁₀H₂₁COOH, C₁₁H₂₃COOH, C₁₂H₂₅COOH, C₁₅H₃₁COOH, C₁₆H₃₃COOH, and C₁₇H₃₅COOH) in styrene–butadiene rubber (SBR) matrix was investigated together with its influence on tribological properties of the vulcanisates. Macro‐ and microtribological properties were correlated with properties that come from carboxylic acid addition to the samples. A plastifying effect was characterized by a decrease of the rubber glass transition temperature measured by the DSC method. Thickness of an acid bloom was directly determined from an indentation experiment and estimated from the DSC curve as well as from FTIR reflection spectra. Morphology of the bloom was studied using an AFM technique to characterize topography as well as microroughness of the bloom surface. Macrofriction was studied using block‐on‐ring tribometer. Microfriction was examined with a Nano Test apparatus, applying ball‐on‐plate contact. Despite correlation found between plastification, morphology, and bloom thickness on the one hand, and tribologic properties of the rubber on the other hand, influence of the chain length of carboxylic acids on properties of the samples still needs further qualitative investigation. Tribological properties of SBR modified with carboxylic acids are the result of balance of two opposite effects: plastification of rubber—leading to an increase of friction and lubrication—which causes a decrease of friction of the rubber. Apart from plastifying and lubrication effects microroughness also plays an important role in friction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3368–3376, 2002     

Chemical Analysis and Comparison of Acid Components of Anal Secretions of Idolothripine Thrips

Anal secretions of 17 species in nine genera of the subfamily Idolothripinae were analzyed by TLC, GC, and GC-MS. From all species, juglone and two or more carboxylic acids with carbon numbers ranging from 10 to 14 were detected; the exception was Gastrothrips sp., from which none was detected. Twelve carboxylic acids were found, of which decanoic acid, (E)-4-decenoic acid, and (Z)-5-tetradecenoic acid were widely found, and acid ingredients were fairly species-specific. The Gastrothrips sp. was the only exception, and it had no secretion components among the tubuliferan species so far analyzed. Juglone is thought to be a potent defensive allomone, and roles of the carboxylic acids are discussed.     

The effect of lyophilization on the solvent extraction of lipid classes,fatty acids and sterols from the oysterCrassostrea gigas

The lipid class compositions of adult Pacific oysters [Crassostrea gigas (Thunberg)] were examined using latroscan thin-layer chromatography/flame-ionization detection (TLC/FID), and fatty acid compositions determined by capillary gas chromatography and gas chromatography/mass spectrometry (GC/MS). The fatty acid methyl esters were separated using argentation TLC and also analyzed as their 4,4-dimethyloxazoline derivatives using GC/MS. Major esterified fatty acids inC. gigas were 16∶0, 20∶5n−3, and 22∶6n−3. C₂₀ and C₂₂ nonmethylene interrupted (NMI) fatty acids comprised 4.5 to 5.9% of the total fatty acids. The NMI trienoic fatty acid 22∶3(7,13,16) was also identified. Very little difference was found in the proportions of the various lipid classes, fatty acids or sterols between samples of adult oysters of two different sizes. However, significant differences in some of the lipid components were evident according to the method of sample preparation used prior to lipid extraction with solvents. Lyophilization (freeze drying) of samples led to a significant reduction in the amounts of triacylglycerols (TG) extracted by solvents in two separate experiments (7.0 and 52.5% extracted). Extracts from lyophilized samples had less 16∶0, C₁₈ unsaturated fatty acids, and 24-ethylcholest-5-en-3β-ol, while C₂₀ and C₂₂ unsaturated fatty acids comprised a higher proportion of the total fatty acids. There was no significant change in the amounts of polar lipids, total sterols, free fatty acids or hydrocarbons observed in extracts from lyophilized samples relative to extracts from nonlyophilized samples. Addition of water to the freezedried samples prior to lipid extraction greatly improved lipid yields and resulted in most of the TG being extracted.     

Composition and Source Apportionment of Organic Aerosol in Beirut,Lebanon, During Winter 2012

Fine organic aerosols were collected at a semi-urban site in Beirut, Lebanon, from 28 January to 12 February 2012 as part of the Emission and Chemistry of Organic Carbon in East Mediterranean-Beirut (ECOCEM-Beirut). A total of 20 quartz filter samples were collected on a 12 h basis using a high-volume sampler and were analyzed using a GC/MS technique. Levoglucosan was the major most abundant single component with an average value of 306 ng.m^?3, followed by saturated and unsaturated carboxylic acids and sugars with average values of 234 and 118 ng.m^?3, respectively. Reported values for other carboxylic acids, polycyclic aromatic hydrocarbons, and biogenic secondary organic aerosols (BSOA) were 87, 33 and 21 ng.m^?3, respectively. Compared to a similar field campaign conducted in summer 2011, levoglucosan concentrations were lower in summer by a factor of 6, due to the use of wood burning for residential heating in winter. Concentrations of saturated and unsaturated carboxylic acids, other carboxylic acids, and BSOA were higher in summer by a factor of 3, 2, and 7, respectively. Higher concentrations observed for BSOA and other dicarboxylic acids during summer are due to higher biogenic emissions and greater photochemical activity in summer.

Copyright 2013 American Association for Aerosol Research     

Novel feature of nano‐titanium dioxide on textiles: Antifelting and antibacterial wool

In this study, the antifelting and antibacterial features of wool samples treated with nanoparticles of titanium dioxide (TiO₂) were evaluated. To examine the antifelting properties of the treated samples, the fabric shrinkage after washing was determined. The antimicrobial activity was assessed through the calculation of bacterial reduction against Escherichia coli (Gram‐negative) and Staphylococcus aureus (Gram‐positive) bacteria. TiO₂ was stabilized on the wool fabric surface by means of carboxylic acids, including citric acid (CA) and butane tetracarboxylic acid (BTCA). Both oxidized samples with potassium permanganate and nonoxidized wool fabrics were used in this study. The relations between both the TiO₂ and carboxylic acid concentrations in the impregnated bath and the antifelting and antibacterial properties are discussed. With increasing concentration in the impregnated bath, the amount of TiO₂ nanoparticles on the surface of the wool increased; subsequently, lower shrinkage and higher antibacterial properties were obtained. The existence of TiO₂ nanoparticles on the surface of the treated samples was proven with scanning electron microscopy images and energy‐dispersive spectrometry. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Discriminant Analysis of Sunflower Seeds for Fatty Acid Composition Using NIR Spectroscopy

Near-infrared reflectance (NIR) spectroscopy data from sunflower seeds of genotypes differing in oleic and linoleic fatty acid contents were evaluated by discriminant analysis. A single husked seed was used for spectral analysis of each genotype. We applied two clustering strategies to discriminate the genotypes. First, we fit three calibration curves for high oleic × low oleic, high oleic × mid-oleic and mid-oleic × low oleic genotype-derived fatty acids. Next, we fit just one curve to all these three groups. All these curves were established using principal component analysis. The clustering precision was determined by d, the Mahalanobis distance between the genotype and the closest group, and D, the distance up to the next group. The spectral range used for calibration was 1,651–1,952 nm. The genotypes were well classified when d was close to one and the ratio D/d was close to or higher than two. The discriminant analysis allowed the classification of the high oleic and mid-oleic genotypes even though they had similar signals in gas chromatography (GC). Although both clustering strategies were similar, the first one allowed a better discrimination between the mid-oleic and low oleic genotypes.     

Behavioral and Chemical Investigations of Contact Kairomones Released by the Mud Dauber Wasp <Emphasis Type="Italic">Trypoxylon politum</Emphasis>, a Host of the Parasitoid <Emphasis Type="Italic">Melittobia digitata</Emphasis>

Contact kairomones from the host mud dauber wasp Trypoxylon politum Say (Hymenoptera: Crabronidae) that mediate behavioral responses of its ectoparasitoid Melittobia digitata Dahms (Hymenoptera: Eulophidae) were investigated. Chemical residues from host by-products, the cocoon, and the meconium, induced arrestment behavior of macropterous female parasitoids, while those from the host stage attacked, i.e., the prepupa, did not. Melittobia digitata response to polar and apolar extracts of host by-products indicated kairomone(s) solubility mainly in hexane. GC and GC/MS analysis of cocoon and meconium apolar extracts revealed a mixture of linear carboxylic acids from C₆ to C₁₈, and both extracts contained almost identical compounds. When a reconstructed blend of host by-product carboxylic acids was tested, M. digitata females showed only a weak response, thus suggesting that other unidentified compounds present in small quantities also may be involved. Melittobia digitata’s response to contact kairomones was innate and not affected by previous host exposure experience. Our results provide evidence of contact kairomone exploitation in the genus Melittobia. The ecological significance of these findings in the host selection process of M. digitata is discussed.     

Chemistry of odortypes in mice: Fractionation and bioassay

Mice can discriminate samples of urine obtained from two groups of inbred mice that are genetically identical except in their major histocompatibility complex (MHC) haplotype (congenic mice), whereas they cannot distinguish urine samples from two genetically identical groups of mice. Chemical fractions of urine samples obtained from MHC congenic mice were tested in a Y-maze olfactometer using a method modified to accommodate the bioassay to chemical fractions that might differ in sensory properties from the unfractionated urine. Fractions depleted in protein by several methods were consistently discriminable by mice in the Y maze, providing a direct demonstration that the airborne MHC genotype information can be conveyed by volatile compounds alone.     

A new procedure for the synthesis of α-acyloxy aldehydes from ketones via α,β-epoxy sulfides

α-Acyloxy aldehydes, as O-protected α-hydroxy aldehydes, have been prepared in good yields via a new procedure involving the sequence: (1) reaction of ketones with sulfur ylides to give α,β-epoxy sulfides, (2) ring opening with carboxylic acids, (3) oxidation of the α-acyloxy-β-hydroxy sulfide products by mCPBA to the corresponding sulfones; and (4) acyl migration followed by elimination of the sulfinate group. The last transformation was readily accomplished, in very good yields, by equivalent amounts of triethylamine in dichloromethane at room temperature (method A); or by acyl migration assisted by complexation of the liberated alkanthiol accomplished in the α-acyloxy-β-hydroxy sulfides by Ag₂O in acetonitrile to give the same α-acyloxy aldehydes (method B). The presented procedure, compared to alternative procedures, has advantages including easily available key intermediates (α,β-epoxy sulfides), mildness of the reactions conditions, more general procedure (applied to different types of α-hydroxy aldehydes).