BACKGROUND Traumatic diaphragmatic ruptures affect mainly the left side. In an experimental study in human corpses we examined the stretch behaviour of the left and right diaphragmatic halves. METHODS In a total of 8 male and 8 female corpses each diaphragmatic half was divided into 4 different segments. Each segments stretch behaviour was investigated. In steps of 2 N the stretch was increas...

The presence of stomata is a diagnostic trait of all living and extinct land plants with the exception of liverworts. They are preserved widely in the fossil record from anatomically pristine stomatal complexes on permineralized and charcoalified stems of the earliest land plants dating back .400 million years to isolated guard cell pairs in quaternary aged palynological samples. Detailed study...

The presence of stomata is a diagnostic trait of all living and extinct land plants with the exception of liverworts. They are preserved widely in the fossil record from anatomically pristine stomatal complexes on permineralized and charcoalified stems of the earliest land plants dating back .400 million years to isolated guard cell pairs in quaternary aged palynological samples. Detailed study...

The current study, devoted to leaf micromorphology of tribe Agrimonieae in Iran including three genera (Agrimonia, Aremonia,and Sanguisorba),four species (Agrimonia eupatoria,Aremonia agrimonioides,S. minor, and S. officinalis), and six subspecies (A. eupatoria subsp. eupatoria, A. eupatoria subsp. grandis, A. eupatoria subsp. asiatica, S. minor subsp. minor, S. minor subsp. lasiocarpa, and S. ...

Stomata are pores that regulate plant gas exchange [1]. They evolved more than 400 million years ago [2, 3], but the origin of their active physiological responses to endogenous and environmental cues is unclear [2-6]. Recent research suggests that the stomata of lycophytes and ferns lack pore closure responses to abscisic acid (ABA) and CO(2). This evidence led to the hypothesis that a fundame...

Cyclin D (CYCD) plays an important role in cell cycle progression and reentry in response to external signals. Here, we demonstrate that Arabidopsis thaliana CYCD4 is associated with specific cell divisions in the hypocotyl. We observed that cycd4 T-DNA insertion mutants had a reduced number of nonprotruding cells and stomata in the hypocotyl epidermis. Conversely, CYCD4 overexpression enhanced...

The proper number and distribution of stomata are essential for the efficient exchange of gases between the atmosphere and the aerial parts of plants. We show that the density and development of stomatal complexes on the epidermis of Arabidopsis thaliana leaves depend, in part, on the microRNA-mediated regulation of Agamous-like16 (AGL16), which is a member of the MADS box protein family. AGL16...

Stomata are formed by a pair of guard cells which have thickened, elastic cell walls to withstand the large increases in turgor pressure that have to be generated to open the pore that they surround. We have characterized FOCL1, a guard cell-expressed, secreted protein with homology to Hyp-rich cell wall proteins. FOCL1-GFP localizes to the guard cell outer cuticular ledge and plants lacking FO...

Long-lived shade leaves of avocado had extremely low rates of photosynthesis. Gas exchange measurements of photosynthesis were of limited use, so we resorted to Chl fluorescence imaging (CFI) and spot measurements to evaluate photosynthetic electron transport rates (ETRs) and non-photochemical quenching (NPQ). Imaging revealed a remarkable transient heterogeneity of NPQ during photosynthetic in...