Testing for Smooth Transition Effects in Probit Models

2011 ◽  
Author(s):  
Daniele Massacci
Keyword(s):  
Smooth Transition ◽  
Probit Models ◽  
Transition Effects

Design and Testing of an Experimental IPv4-to-IPv6 Transition Network

2006 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Mustaffa Samad
Keyword(s):  
Transition Period ◽  
Internet Protocol ◽  
Smooth Transition ◽  
Internet Users ◽  
Ipv6 Transition ◽  
Information And Communication ◽  
Ipv6 Networks ◽  
And Migration ◽  
Set Up ◽  
Design And Testing

The Internet has been an integral part of the Information and Communication Technology (ICT) community in recent years. New internet users have been growing steadily over the years. This has lead to the depletion of new Internet Protocol (IP) addresses worldwide. To overcome this predicament, the new Internet Protocol version 6 (IPv6) had been introduced. The existing Internet Protocol version 4 (IPv4) is expected to be eventually replaced by this IPv6. The changeover from IPv4 to IPv6 is expected to be implemented progressively. During this transition period, these two protocols are expected to coexist for a number of years. IPv4-to-IPv6 transition tools have been designed to facilitate a smooth transition from IPv4 to IPv6. The two most basic IPv4-to-IPv6 transition tools available are the hybrid stack mechanism and tunneling. Tunneling is the encapsulation of IPv6 traffic within IPv4 packets so they can be sent over an IPv4 infrastructure. This project was initiated to set up an experimental IPv6 testbed, in order to study the performance as well as transition and migration issues of IPv6 networks under controlled conditions. This paper looks at how tunneling can be performed over existing internetwork infrastructure at Fakulti Kejuruteraan Elektrik (FKE), UiTM.

Topping-off technique for stabilization of lumbar degenerative instabilities in 322 patients

2020 ◽  
Vol 32 (3) ◽  
pp. 366-372
Author(s):  
Sandro M. Krieg ◽  
Nele Balser ◽  
Haiko Pape ◽  
Nico Sollmann ◽  
Lucia Albers ◽  
...  
Keyword(s):  
Patient Satisfaction ◽  
Interbody Fusion ◽  
Smooth Transition ◽  
Lumbar Pain ◽  
Adjacent Segment ◽  
Lumbar Interbody Fusion ◽  
Rod System ◽  
Reoperation Rates ◽  
Topping Off

OBJECTIVESemi-rigid instrumentation (SRI) was introduced to take advantage of the concept of load sharing in surgery for spinal stabilization. The authors investigated a topping-off technique in which interbody fusion is not performed in the uppermost motion segment, thus creating a smooth transition from stabilized to free motion segments. SRI using the topping-off technique also reduces the motion of the adjacent segments, which may reduce the risk of adjacent segment disease (ASD), a frequently observed sequela of instrumentation and fusion, but this technique may also increase the possibility of screw loosening (SL). In the present study the authors aimed to systematically evaluate reoperation rates, clinical outcomes, and potential risk factors and incidences of ASD and SL for this novel approach.METHODSThe authors collected data for the first 322 patients enrolled at their institution from 2009 to 2015 who underwent surgery performed using the topping-off technique. Reoperation rates, patient satisfaction, and other outcome measures were evaluated. All patients underwent pedicle screw–based semi-rigid stabilization of the lumbar spine with a polyetheretherketone (PEEK) rod system.RESULTSImplantation of PEEK rods during revision surgery was performed in 59.9% of patients. A median of 3 motion segments (range 1–5 segments) were included and a median of 2 motion segments (range 0–4 segments) were fused. A total of 89.4% of patients underwent fusion, 73.3% by transforaminal lumbar interbody fusion (TLIF), 18.4% by anterior lumbar interbody fusion (ALIF), 3.1% by extreme lateral interbody fusion (XLIF), 0.3% by oblique lumbar interbody fusion (OLIF), and 4.9% by combined approaches in the same surgery. Combined radicular and lumbar pain according to a visual analog scale was reduced from 7.9 ± 1.0 to 4.0 ± 3.1, with 56.2% of patients indicating benefit from surgery. After maximum follow-up (4.3 ± 1.8 years), the reoperation rate was 16.4%.CONCLUSIONSThe PEEK rod concept including the topping-off principle seems safe, with at least average patient satisfaction in this patient group. Considering the low rate of first-tier surgeries, the presented results seem at least comparable to those of most other series. Follow-up studies are needed to determine long-term outcomes, particularly with respect to ASD, which might be reduced by the presented approach.

Sign in / Sign up

Export Citation Format

Share Document