Male-Induced Sociosexual Behavior by Vaginal Secretions in Macaca arctoides

Odor communication in Old World monkeys and apes is controversial, because most females have evolved visual and behavioral cues to signal fertility, e.g., sexual swellings. Female stump-tailed macaques (Macaca arctoides) do not have swellings, and mediation of chemical communication likely occurs because males engage in sexual behavior mostly throughout the periovulatory phase of the menstrual cycle. We tested whether vaginal secretions from different cycle phases, with saline solution as a control, promote changes in the frequency of male genital exploration, copulation, and coercive behavior toward females different from the donors, while female donors were apart from the group. Males explored more female genitals when exposed to follicular, periovulatory, and early luteal secretions in comparison to saline or menstrual or late luteal secretions. The increase in coercive behavior after exposure to follicular and periovulatory secretions most likely was a male response to the lack of cooperation of target females in engaging in copulation, as the latter were not receptive during the tests. The strength of male response to vaginal secretions varied significantly as a result of individual variability between donor females, yet the variability does not correlate either to dominance rank or to female age. Exploratory behavior of males correlates significantly with their social rank. Our results suggest that vaginal secretions are among the cues that male Macaca arctoides use to acknowledge the reproductive status of females in the absence of visual signals.     

Substrate preference of Bifidobacterium adolescentis MB 239: compared growth on single and mixed carbohydrates

The utilization of mono-, di-, and oligosaccharides by Bifidobacterium adolescentis MB 239 was investigated. Raffinose, fructooligosaccharides (FOS), lactose, and the monomeric moieties glucose and fructose were used. To establish a hierarchy of sugars preference, the kinetics of growth and sugar consumption were determined on individual and mixed carbohydrates. On single carbon sources, higher specific growth rates and cell yields were attained on di- and oligosaccharides compared to monosaccharides. Analysis of the carbohydrates in steady-state chemostat cultures, growing at the same dilution rate on FOS, lactose, or raffinose, showed that monomeric units and hydrolysis products were present. In chemostat cultures on individual carbohydrates, B. adolescentis MB 239 simultaneously displayed α-galactosidase, β-galactosidase, and β-fructofuranosidase activities on all the sugars, including monosaccharides. Glycosyl hydrolytic activities were found in cytosol, cell surface, and growth medium. Batch experiments on mixtures of carbohydrates showed that they were co-metabolized by B. adolescentis MB 239, even if different disappearance kinetics were registered. When mono-, di-, and oligosaccharides were simultaneously present in the medium, no precedence for monosaccharides utilization was observed, and di- and oligosaccharides were consumed before their constitutive moieties.     

Fear-like behavioral responses in mice in different odorant environments: Trigeminal versus olfactory mediation under low doses

Odors can have repulsive effects on rodents based on two complementary adaptive behaviors: the avoidance of predator odors (potentially dangerous) and the avoidance of trigeminal stimulants (potentially noxious). The present study aimed to compare the behavioral effects on mice of odors according to their trigeminal properties and ecological significance. We used three different odors: 2,4,5-trimethylthiazoline (TMT: a fox feces odor frequently used to elicit fear-induced behaviors), toluene (a strong stimulant of the trigeminal system) and phenyl ethyl alcohol (PEA: a selective stimulant of the olfactory system). First, we checked preference and avoidance behaviors in mice with and without anosmia towards these odors to ensure their olfactory/trigeminal properties. Secondly, we used a standard test (open-field and elevated plus-maze) to assess the behaviors of mice when exposed to these odors. The results show that the anosmic and control mice both avoided TMT and toluene odors. In the open-field and the elevated plus-maze, mice exhibited "anxious" behaviors when exposed to TMT. Conversely, exposure to PEA induced "anxiolytic" effects confirmed by low blood corticosterone levels resulting from completion of the elevated plus-maze. Compared with TMT exposure, toluene exposure induced moderate "anxious" effects.     

Food Aversion Plus Odor Cue Protects Crop From Wild Mammals

Abstract: Wild mammals cause foraging damage to crops worldwide and nonlethal methods are required for controlling such damage. Many wildlife management situations demand protection of untreated foods. We tested learned food aversion plus an odor cue as a paradigm for protecting untreated model crop items from European badgers (Meles meles). Following conditioning with a combination of ziram and clove oil, badgers avoided untreated maize cobs in presence of a clove odor cue. A clove oil control did not condition badgers. This work has been an important step before proceeding to full-scale field trials for protecting growing crops on a wider scale. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):785–791; 2008)     

The effects of interspecific competition and prey odor on foraging behavior in the rock crab, Cancer irroratus (Say)

The effects of competitor pressure and prey odor on foraging behavior of the rock crab, Cancer irroratus (Say), were investigated. The Jonah crab, Cancer borealis (Stimpson), was chosen as the interspecific competitor because it shares resources with C. irroratus. Four treatments were tested for their effect on foraging: the presence or absence of a competitor and two types of prey odor; body odor (living mussel) and tissue extract (dead mussel tissue). The presence of Jonah crabs did not influence location time, search time, prey size selected, or handling time of the rock crabs. However, rock crabs responded differently to the presence of body odor and tissue extract cues. The presence of extract odor decreased the time to locate prey while increasing the number of prey manipulated and prey size selected. When prey body odor was present, rock crabs displayed less investigative behaviors than in the presence of extract odor, illustrated by reduced location time. Extract odor provided a stronger and more attractive cue than body odor, but increased prey manipulation and search time. Extract odor induced increases in manipulation and searching for prey but canceled out the benefits of decreased location time, resulting in crabs from both treatments displaying similar search times. These elevated behaviors may be associated with foraging for injured and cracked prey or may indicate an area of conspecific feeding.     

Assessing Toxicity of Mixtures: The Search for Economical Study Designs

Toxicity screening and testing of chemical mixtures for interaction effects is a potentially onerous task due to the sheer volume of combinations that may be of interest. We propose an economical approach for assessing the interaction effects of chemical mixtures that is guided by risk-based considerations. We describe the statistical underpinnings of the approach and use examples from the published literature to illustrate concepts of local versus global mixture assessment. Our approach employs a sequential testing procedure to find the dose combinations that define the dose boundary for a specified acceptable risk level. The first test is conducted for a dose combination consisting of the acceptable doses of each individual chemical in the mixture. The outcome of this first test indicates the dose combination that should be tested next. Continuing in this manner, the boundary of dose combinations for the specified acceptable risk level can be approximated based on measurements for relatively few dose combinations. Dose combinations on one side of the boundary would have responses less than the response associated with the acceptable risk level, and dose combinations on the boundary would be acceptable levels of exposure for the mixture.     

Reaction Kinetics of Immobilized α-Chymotrypsin in Organic Media 1. Influence at Solvent Polarity

Esterification of N-acetyl phenylalanine with ethanol catalyzed by immobilized α-chymotrypsin (EC 3.4.21.1) was studied in various reaction media. The effect of reaction medium polarity on enzymatic activity as well as equilibrium yield was measured. The reaction rate increased with increasing amounts of added water, reaching an optimum corresponding to water saturation of the reaction medium. Further additions of water resulted in decreased activity. Bell-shaped activity profiles were obtained for all reaction media tested. Reaction media consisting of pure solvents and of mixtures of solvents were used. The enzymatic activity and the equilibrium yield increased with decreased polarity of the medium. Maximum activity was found in a reaction medium consisting of 80% diisopropyl ether and 20% heptane. The enzymatic activity obtained at optimal water additions in the different solvents and solvents mixtures could be correlated to the solubility of water and the log P of the medium. The equilibrium yield of the reaction was much more closely correlated to the solubility of water than the log P. Much lower enzymatic activity was obtained when solvent mixtures producing water-miscible media were created, than in mixtures producing water-immiscible media, such as mixtures of acetonitrile and diisopropyl ether. The equilibrium yield could be increased by decreasing the water content in the reaction medium, which reduced the water activity.