Optimisation in behavioural synthesis using hierarchical expansion: module ripping

During behavioural synthesis, an abstract functional description of a system is mapped automatically onto a physical structure. In a competitive setting, this mapping will be highly optimised - the dataflow is re-arranged, units and registers are multiplexed and so on - to deliver a final structure that meets some overall user supplied specification. Ultimately, however, the physical functional units are drawn from some predefined (human designed) library - these may be thought of as the leaf-level modules in the design hierarchy. Design re-use and increasing sophistication of module libraries inevitably leads to leaf modules becoming larger and more complex. As these modules are, by definition, atomic, a synthesis system is unable to capitalise on any internal similarities the leaf modules may possess. This paper describes the design, construction and effects of using a hierarchically defined module library. The set of leaf-level modules made available to the synthesis environment is conventional - add, subtract, multiply and so on - but the optimiser is capable of ?ripping apart? these modules to manipulate their inner structures. Two advantages accrue from this technique: (1) it is possible to optimise behavioural designs far more effectively, with up to a 65% reduction in area, and a 46% reduction in delay reported, and (2) it is possible to build library modules that have tightly controllable internal timing relationships. This is essential when designing systems that communicate externally via low-level protocols, but behavioural synthesis, by its very nature, usually distorts timing information. Using this technique, it is possible to create ?islands of fixed timing? embedded in the synthesised design

Intrathecal treatment of neoplastic meningitis due to breast cancer with a slow-release formulation of cytarabine

DepoCyte is a slow-release formulation of cytarabine designed for intrathecal administration. The goal of this multi-centre cohort study was to determine the safety and efficacy of DepoCyte for the intrathecal treatment of neoplastic meningitis due to breast cancer. DepoCyte 50 mg was injected once every 2 weeks for one month of induction therapy; responding patients were treated with an additional 3 months of consolidation therapy. All patients had metastatic breast cancer and a positive CSF cytology or neurologic findings characteristic of neoplastic meningitis. The median number of DepoCyte doses was 3, and 85% of patients completed the planned 1 month induction. Median follow up is currently 19 months. The primary endpoint was response, defined as conversion of the CSF cytology from positive to negative at all sites known to be positive, and the absence of neurologic progression at the time the cytologic conversion was documented. The response rate among the 43 evaluable patients was 28% (CI 95%: 14–41%); the intent-to-treat response rate was 21% (CI 95%: 12–34%). Median time to neurologic progression was 49 days (range 1–515(+)); median survival was 88 days (range 1–515(+)), and 1 year survival is projected to be 19%. The major adverse events were headache and arachnoiditis. When drug-related, these were largely of low grade, transient and reversible. Headache occurred on 11% of cycles; 90% were grade 1 or 2. Arachnoiditis occurred on 19% of cycles; 88% were grade 1 or 2. DepoCyte demonstrated activity in neoplastic meningitis due to breast cancer that is comparable to results reported with conventional intrathecal agents. However, this activity was achieved with one fourth as many intrathecal injections as typically required in conventional therapy. The every 2 week dose schedule is a major advantage for both patients and physicians. © 2001 Cancer Research Campaign http://www.bjcancer.co

Association of sella turcica bridging with palatal canine impaction in skeletal Class I and Class II

Laila Fawzi Baidas,1 Huda Mohammad Al-Kawari,1 Zhara Al-Obaidan,2 Aqeelah Al-Marhoon,2 Sawsan Al-Shahrani2 1Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia; 2College of Dentistry, King Saud University, Riyadh, Saudi Arabia Purpose: Based on the evidence of the embryonic origin of the sella turcica and the teeth, this retrospective study evaluated the association between sella turcica bridging and palatal canine impaction in skeletal Class I and Class II orthodontic patients.Methods: Sixty-two orthodontic patients with palatally impacted canines and 54 controls with erupted canines (aged 12–25 years) were classified into skeletal Class I and Class II ­(according to ANB angle and Wits analysis). The length, depth, and diameter of the sella turcica were ­measured, and the shape was described. The difference in linear dimensions between the study and control groups was calculated using two-way analysis of variance and Student’s t-test. The ­interrelationship of the variables, subject groups, skeletal type, and age, with the linear ­dimensions of sella turcica, was tested using regression analyses. The association between sella turcica, bridging and palatally impacted canines was determined in skeletal type using a chi-square test.Results: Highly significant differences were found in the length, diameter, and depth of the sella turcica between the study sample and the control (P<0.001, P=0.015, P<0.0001, respectively). There was a highly significant frequency of bridging in cases with palatally impacted canines (P<0.0001). An increasing incidence of bridging was found in subjects with palatally impacted canines and skeletal Class I (P<0.0001) and Class II (P=0.044) relationships. Regression analysis showed that the age was significantly related to a change in length (P=0.025), diameter (P<0.0001), and depth (P<0.0001). The normal sella turcica morphology was present in most subjects (56.4%), and no significant association was found in subjects with palatally impacted canines in terms of the shape of the sella turcica.Conclusion: Sella turcica bridging is frequently seen in patients with impacted canines. The findings suggest that careful monitoring of canine eruption is required in patients diagnosed with sella turcica bridging at an early age. Keywords: sella turcica bridging, sella turcica shape, skeletal type, palatally impacted canin