An approximate expression for the motional capacitance of a lateral field resonator

A simple approximate expression is obtained for the motional capacitance of a lateral-field quartz resonator. Comparison with measured values for fundamental-mode and third-overtone SC-cut resonators shows agreement within 10-50%     

Performance characterisation of the MCNS DOCSIS 1.0 CATV protocolwith prioritised first come first served scheduling

The Multimedia Cable Networks Systems (MCNS) Data Over Cable Service Interface Specifications (DOCSIS) is established as the primary cable network data communications standard. The head-end scheduling algorithm is not defined within the standard but it is the key function for providing the required performance capability. Computer simulation, using the Common Simulation Framework (CSF) 12 version of the CableLabs DOCSIS 1.0 computer model, has been used to predict the upstream system throughput and mean access delay. A prioritised first come first served scheduling algorithm has been considered to provide a baseline reference set of performance statistics against which other algorithms can be compared. The simulations, with theoretical confirmation, have shown that the maximum sustainable system throughput is 1965 kbps for a channel capacity of 2560 kbps and a packet size of 1500 octets, whereas for packet size of 100 octets the maximum sustainable throughput is only 1550 kbps. The mean access delay is found to vary between 10-900 ms depending on the offered load and assuming that the offered load does not exceed the capacity of the channel. Excess offered load causes service starvation according to the assigned priority     

New thoughts about thinking.

Reviews the book, The Nature of Thought: Essays in Honor of D.O. Hebb edited by P.W. Jusczyk and R.M. Klein (1980). The phenomenon of thinking, the topic to which this important collection of essays is addressed, is one of the principal perennial concerns of psychology. It is as fundamental and as unsolved a problem today as at the time of experimental psychology's introspectionist beginnings and, through the ensuing decades, has never ceased to stimulate, fascinate, baffle, and bewilder the serious student of psychological phenomena. The present volume appropriately reflects a wide spectrum of specific concerns and approaches to this topic. Appropriate, as well, is its dedication in honour of D.O. Hebb, whose own approach to the study of thought is especially broad and encompassing. The book resulted from a recent series of lectures, in Hebb's honour, at Dalhousie University. This is not, however, a volume primarily addressed to Hebb's ideas. Rather, it is a collection of progress reports by a number of distinguished researchers in the fields of human and animal cognition on recent approaches to topics such as consciousness, mental imagery, problem solving, representation, attention, and skilled performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The composition of imaginal transformations.

Three experiments with 54 volunteers (aged 17–28 yrs) examined the performance of composite imaginal transformations using tasks in which Ss performed pairs of distinct imaginal transformations either in close succession or simultaneously. Results obtained under a number of distinct task conditions were most consistent with the proposal of noninteractive composition. Implications for analog-spatial models, task demand, and procedural accounts of imaging are discussed. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0 mm and an average caloric density of 611 cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.     

Calcium and endoplasmic reticulum dynamics during oocyte maturation and fertilization in the marine worm Cerebratulus lacteus

Disseminated gonococcal infection is the most common systemic complication of acute gonorrhea and occurs in 0.5% to 3.0% of patients with untreated mucosal infection. It is also the most common cause of septic arthritis in patients less than 30 years of age. Fortunately, the incidence of gonorrhea is decreasing dramatically in the United States and Western Europe, although it is still high in developing countries. Increasing resistance to antibiotics requires continuous surveillance of antimicrobial susceptibilities to determine the efficacy of current therapeutic measures.