Guard cells are a valuable model system for the study of photoreception, ion transport, and osmoregulation in plant cells. Changes in stomatal apertures occur when sensing mechanisms within the guard cells transduce environmental stimull into the ion fluxes and biosynthesis of organic solutes that regulate turgor. The electrical events mediating sensory transduction in guard cells can be charac...

Existing proposals for implementing the run-time suspension test for GHC concentrate upon suspending unifications in the bodies of clauses being used to evaluate guard literals. However, by making simple alterations to the guard and adding special primitives to it to localise the requirement to suspend to a primitive in the guard, unifications in the bodies of clauses may proceed without being ...

Increased variability in stomatal aperture at high temperatures can be attributed, in part, to the differential sensitivity of guard cells to thermal damage. Individual stomata become increasingly open at higher temperatures until guard cells are lethally damaged; at that temperature, apertures decrease. The extent of irreversible damage causing closure was estimated by K(+) uptake, neutral red...

From the Department of Pediatric Gastroenterology (Hasosah), King Abdulaziz Medical City, National Guard Hospital, Jeddah, and the Departments of Pediatric Gastroenterology (Al-Sunaid), and Medical Imaging (Al-Shaalan), King Abdulaziz Medical City, National Guard Hospital, Riyadh, Kingdom of Saudi Arabia. Address correspondence to: Dr. Mohammed Y. Hasosah, Department of Pediatric Gastroenterolo...

Dropping probability of handoff calls and blocking probability of new calls are two important QoS measures for cellular networks. Call admission policies, such as fractional guard channel and uniform fractional guard channel policies are used to maintain the pre-specified level of QoS. Since the parameters of network traffics are unknown and time varying, the optimal number of guard channels is...

A 993-bp regulatory region upstream of the translation start codon of subtilisin-like serine protease gene was isolated from Gossypium barbadense. This (T/A)AAAG-rich region, GbSLSP, and its 5'- and 3'-truncated versions were transferred into tobacco and Arabidopsis after fusing with GUS or GFP. Histochemical and quantitative GUS analysis and confocal GFP fluorescence scanning in the transgenic...

Elevated carbon dioxide (CO2) in leaves closes stomatal apertures. Research has shown key functions of the β-carbonic anhydrases (βCA1 and βCA4) in rapid CO2-induced stomatal movements by catalytic transmission of the CO2 signal in guard cells. However, the underlying mechanisms remain unclear, because initial studies indicate that these Arabidopsis (Arabidopsis thaliana) βCAs are targeted to d...

In this paper we examine the effects of the required portions of guard timing spaces in a MAC frame of ETSI BRAN HIPERLAN/2 system such as inter-mobile guard timing space in UL(Up Link) duration, inter-RCH(Random CHannel) guard timing space, sector switch guard timing space. In particular, we calculate the number of OFDM(Orthogonal Frequency Division Multiplexing) symbols required for these gua...

The central issue in direct-sequence code-division multiple-access (DS-CDMA) ad hoc networks is the prevention of a near-far problem. This paper considers two types of guard zones that may be used to control the near-far problem: a fundamental exclusion zone and an additional CSMA guard zone that may be established by the carrier-sense multiple-access (CSMA) protocol. In the exclusion zone, no ...

In response to drought stress, the phytohormone abscisic acid (ABA) induces stomatal closure. Thereby the stress hormone activates guard cell anion channels in a calcium-dependent, as well as -independent, manner. Open stomata 1 protein kinase (OST1) and ABI1 protein phosphatase (ABA insensitive 1) represent key components of calcium-independent ABA signaling. Recently, the guard cell anion cha...