The Guard

Guard cells

What are guard cells? A pair of guard cells surrounds each stoma on the leaf surface. Stomata are important because they regulate the uptake of CO 2 from the atmosphere for photosynthesis and also the loss of water vapour from the plant during transpiration. The aperture of the stomatal pore is controlled by the two guard cells. When the guard cells are fully turgid the pore gapes open, whereas...

"On guard at the gateway".

TO the general public the work of the Port Health Service is little known with the result that it gets very little publicity except on those rare occasions when a large passenger liner is held up with a case of suspected smallpox on board. Port health authorities whether they are concerned with a seaport or airport have one major function and that is to protect the country of which they are the...

A change of the guard.

Administration reinstates the Irish Guard

The U n iv e rs i ty r e i n s t a t e d the Irish Guard T u esd ay and it will perform a t S a tu r d a y ’s N o tre D a m e F l o r i d a S t a t e game, school officials said. The Guard m et with F a th e r M ark I’o o r m a n , v ice p r e s i ­ d e n t fo r S t u d e n t A f f a i r s , T u e s d a y to d i s c u s s t h e i r l a c k l u s t e r b e h a v i o r a t th e Oct. 5 Notre D a m...

Implementation Advice for IPv6 Router Advertisement Guard (RA-Guard)

The IPv6 Router Advertisement Guard (RA-Guard) mechanism is commonly employed to mitigate attack vectors based on forged ICMPv6 Router Advertisement messages. Many existing IPv6 deployments rely on RA-Guard as the first line of defense against the aforementioned attack vectors. However, some implementations of RA-Guard have been found to be prone to circumvention by employing IPv6 Extension Hea...