Water addition but not reduction alters plant biomass-diversity relationship.

The relationship between plant aboveground biomass and diversity typically follows a unimodal pattern, showing a positive correlation in resource-poor habitats and a negative correlation in resource-rich environments. Precipitation is a crucial resource for both plant biomass and diversity in terrestrial ecosystems. However, the impact of precipitation changes on the relationship between plant biomass and diversity remains unclear. We conduct a water addition field experiment in a semiarid grassland and identify a unimodal relationship between plant biomass and species richness under ambient conditions. Water addition delays the declining phase of this unimodal curve and shift it upward compared to ambient conditions. Our meta-analysis of water addition experiments conducted across major biomes worldwide (grassland, shrubland, desert, and forest) supports this finding, while water reduction does not alter the biomass-diversity relationship. Water addition increases biomass in all climate but only increases species richness in arid and semiarid climate. Similarly, water reduction decreases biomass in all climate but only reduces species richness in arid and semiarid climate. Species richness in dry subhumid and humid climate does not change significantly. Furthermore, our field experiment shows that water addition increases plant diversity while decreasing soil inorganic nitrogen levels. The increase in one resource, such as water, leads to the scarcity of another, such as nutrient, thus postponing the declining phase of the plant biomass-diversity relationship typically observed in resource-rich habitats. Our research contributes to predicting the plant biomass-diversity relationship under changing precipitation conditions and highlights the complex interplay between water availability, nutrient level, and plant diversity.

GABA and 5-HT systems are implicated in the anxiolytic-like effect of spinosin in mice.

The present study investigated the anxiolytic-like effects of spinosin, one of the major flavonoids in Ziziphi Spinosae Semen (ZSS), in experimental models of anxiety compared with a known anxiolytic, diazepam. Repeated treatment with spinosin (2.5 and 5mg/kg/day, p.o.) significantly increased the percentage of entries into and time spent on the open arms of the elevated plus maze compared with the control group. In the light/dark box test, spinosin exerted an anxiolytic-like effect at 5mg/kg. In the open-field test, 5mg/kg spinosin increased the number of central entries. Spinosin did not affect spontaneous activity. The anxiolytic-like effects of spinosin in the elevated plus maze, light/dark box test, and open field test were blocked by the γ-aminobutyric acid-A (GABAA) receptor antagonist flumazenil (3mg/kg, i.p.) and 5-hydroxytryptamine-1A (5-HT1A) receptor antagonist WAY-100635 (1mg/kg, i.p.). These results suggest that spinosin exerts anxiolytic-like effects, and its mechanism of action appears to be modulated by GABAA and 5-HT1A receptors.

[Analysis of misdiagnosis of calcifying epithelioma in oral and maxillofacial-head and neck region].

Eight patients misdiagnosed as calcifying epithelioma during 2003-2008 at Department of Oral and Maxillofacial Surgery of Cangzhou Central Hospital were retrospectively analyzed. The pertinent literatures were reviewed and the pathogenesis, clinical manifestations, imaging performance and differential diagnosis of calcifying epithelioma were discussed.