Root apex of higher plants shows very high sensitivity to environmental stimuli. The root cap acts as the most prominent plant sensory organ; sensing diverse physical parameters such as gravity, light, humidity, oxygen, and critical inorganic nutrients. However, the motoric responses to these stimuli are accomplished in the elongation region. This spatial discrepancy was solved when we have dis...

objectives : anterior maxilla, known as the esthetic zone, plays an important role in facial and smile esthetics. this study assessed the frequency of implant treatments in the esthetic zone of patients presenting to dental implant department of tehran university during 2002-2012. materials and methods: this descriptive study was conducted on dental records of patients receiving implant treatme...

the arid zone encompasses land that has an imbalance between precipitation and losses through evaporation. globally, arid zones comprise large part of many countries in the mid-latitudes in both the northern and the southern hemispheres. both australia and iran are countries with a large arid zone. this negative water balance in the arid zone affects the type of land use in these countries. at ...