Abstract: A system and method for establishing a voice over Internet protocol link to a called party's mobile telephony device utilizes push notifications to activate a communications application on the called party's mobile telephony communications device. When a request to establish a voice over Internet protocol link to a mobile device is received by an incoming proxy server of a voice over Internet protocol service provider, the service provider causes a push notification to be sent to the mobile device. The called party can respond to the push notification in a manner that causes a communications application on the mobile device to be activated. Once the push notification has caused the communications application to activate, the communications application sends a special registration request to an outbound proxy server.

Abstract: A system and method for establishing a voice over Internet protocol link to a called party's mobile telephony device utilizes push notifications to activate a communications application on the called party's mobile telephony communications device. When a request to establish a voice over Internet protocol link to a mobile device is received by an incoming proxy server of a voice over Internet protocol service provider, the service provider causes a push notification to be sent to the mobile device. The called party can respond to the push notification in a manner that causes a communications application on the mobile device to be activated. Once the push notification has caused the communications application to activate, the communications application sends a special registration request to an outbound proxy server.

Abstract: A system and method for establishing a voice over Internet protocol link to a called party's mobile telephony device utilizes push notifications to activate a communications application on the called party's mobile telephony communications device. When a request to establish a voice over Internet protocol link to a mobile device is received by an incoming proxy server of a voice over Internet protocol service provider, the service provider causes a push notification to be sent to the mobile device. The called party can respond to the push notification in a manner that causes a communications application on the mobile device to be activated. Once the push notification has caused the communications application to activate, the communications application sends a special registration request to an outbound proxy server.

Abstract: A system and method for establishing a voice over Internet protocol link to a called party's mobile telephony device utilizes push notifications to activate a communications application on the called party's mobile telephony communications device. When a request to establish a voice over Internet protocol link to a mobile device is received by an incoming proxy server of a voice over Internet protocol service provider, the service provider causes a push notification to be sent to the mobile device. The called party can respond to the push notification in a manner that causes a communications application on the mobile device to be activated. Once the push notification has caused the communications application to activate, the communications application sends a special registration request to an outbound proxy server.

Abstract: A retaining clip for retaining reagent test slides in a stacked arrangement includes a first assembly having a first cover plate and at least two parallel, co-planar rails extending transversely from an inner surface of the first cover plate. A second assembly includes a second cover plate, and a rail receiving platform extending transversely from an inner surface of the second cover plate. The first cover plate and the second cover plate define between them a space for receiving the plurality of reagent test slides. The rails of the first assembly include ratchet teeth, and the rail receiving platform of the second assembly includes pawls. The pawls engage the ratchet teeth to prevent the separation of the first assembly and the second assembly and to securely but removably hold the plurality of reagent test slides in a stacked arrangement between the first and second cover plates.