In defensive ant-plant interactions myrmecophytic plants express reduced chemical defense in their leaves to protect themselves from pathogens, and it seems that mutualistic partners are required to make up for this lack of defensive function. Previously, we reported that mutualistic ants confer plants of Acacia hindsii protection from pathogens, and that the protection is given by the ant-asso...

Extrafloral nectar (EFN) plays an important role as plant indirect defence through the attraction of defending ants. Like all rewards produced in the context of a mutualism, however, EFN is in danger of being exploited by non-ant consumers that do not defend the plant against herbivores. Here we asked whether plants, by investing more in EFN, can improve their indirect defence, or rather increa...

Rheological properties of waxy barley flour (WBF) dispersions mixed with various gums (carboxyl methyl celluleose, guar gum, gum arabic, konjac gum, locust bean gum, tara gum, and xanthan gum) at different gum concentrations were examined in steady and dynamic shear. WBF-gum mixture samples showed a clear trend of shear-thinning behavior and had a non-Newtonian nature with yield stress. Rheolog...

Pierce’s disease (PD) causes symptoms of leaf scorch and fruit cluster wilt on wine, table and raisin grapes, and is caused by the bacterial pathogen Xylella fastidiosa. These fastidious, gram-negative bacteria occur only in the xylem of infected plants and are transmitted by xylem-feeding insects; leafhoppers and sharpshooters. The close association of plants with bacteria, either pathogenic o...

BACKGROUND Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior. METHODS WE TESTED CEREBRAL BLOOD FLOW (CBF) IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no ...

Many anticancer drugs exert their cytotoxicity by inhibiting DNA synthesis and cell replication. However, side effects such as bone marrow suppression, gastrointestinal toxicity, and renal damage remain to be addressed (Peterson et al., 1992). One avenue to developing clinically applicable chemotherapeutic agents with fewer complications is to screen traditional medicinal plants, which have bee...

Two experiments examined whether chewing spearmint gum can affect the initial learning or subsequent recall of a word list. Comparing those participants in Experiment 1 who chewed gum at the learning or the recall phases showed that chewing gum at initial learning was associated with superior recall. In addition, chewing gum led to context-dependent effects as a switch between gum and no gum (o...

In the past few decades, discharging thousands of organic, inorganic, and biological pollutants into environment has severely deteriorated water quality especially the heavy metals pollution which could be concentrated in organisms and, thus, harmful to most plants and animals not only at a high dose but also in relatively low concentration [1]. The continuous existence of heavy metal contamina...

We investigated whether change of emotion related to sourness during chewing causes higher brain functions by using mental arithmetic test. Subjects comprised 120 healthy individuals. The mental arithmetic test was performed under four conditions: chewing lemon-flavored gum (Standard gum, as a delicious gum); gum with 6 times the citric acid component of the Standard gum (Strong-sour gum, as an...

Gum arabic is mainly produced from two Acacias that are found in the gum belt of Sub-Saharan Africa. These are Acacia senegal that produces high quality gum and Acacia seyal that produces low quality gum. In recent years the gum market structure has changed and Sudan lost its near monopoly position as Chad and Nigeria became important gum suppliers. In order to understand the competition betwee...