bluuebunny/crossref_metadata_2025 huggingface dataset:
Object oriented database using frames in second generation APL
Authors: Pantziarka Panagiotis
Published: January 2007

The appeal of Object Oriented systems and methodologies is that they provide conceptually simple and powerful tools to represent the real-world. The essential elements of object orientation include: information hiding, classes, dynamic instantiation of objects, methods and the inheritance of properties by objects.

Frames are a way to combine both data and procedures to represent knowledge. This paper describes a frame representation system that is used to create a simple object oriented database. The frame structures are described and it is shown that they can be represented as nested arrays. The inheritance mechanisms are detailed and functions developed to handle the frames. Finally a proposal is made for the further development of frame structured systems in APL.
Reading to write
Authors: Polivka Raymond P.
Published: January 2007

Teaching a programming language offers many challenges. Foremost, of course, is the question of how to present the material. Part of any presentation are the drills and exercises. Frequently, after the content has been presented, the student is asked to write a program. This is much akin to asking a student, who has just been exposed to the grammar and some vocabulary of a new language, to write an essay in that language.

This paper will discuss several alternate approaches in presenting exercises to develop the proficiency of a student in the use of a programming language.
Managing a diamond jewelry manufacturing business using APL
Authors: Promisel Steven I. , Merrill James V.
Published: January 2007

We discuss the development of several interconnected computer systems designed and built for a manufacturer of finished jewelry. Our approach will be two-fold. We describe how the company uses APL-based computer systems to analyze pricing issues and handle the manufacturing process. We show how the system has been developed by describing what techniques have been employed and what tools have been created and used. The purpose of this paper is to show how an APL application development system can be used to build continually evolving interactive computer systems in a combined sales and manufacturing environment.
Toward a common prototyping language
Authors: Rudd Jack G. , Brown James A.
Published: January 2007

Several years ago the U.S. Department of Defense created its Defense Science Board Task Force on Military Software, chaired by Dr. Frederick Brooks, to provide recommendations on how best to solve the problem of escalating military software acquisition costs. The final report (reference 2) of this task force was completed in September 1987, and was widely distributed. Among its several major conclusions are the following:

DoD Directive 5000.29 and STD 2167 codify the best 1975 thinking about software, including a so-called 'waterfall' model calling for formal specification, then request for bids, then contracting, delivery, installation, and maintenance. In the decade since the waterfall model was developed, our discipline has come to recognize that setting the requirements is the most difficult and crucial part of the software building process, and one that requires iteration between the designers and users. In best modern practice, the early specification is embodied in a prototype, which the intended users can themselves drive in order to see the consequences of their imaginings. Then, as the design effort begins to yield data on the cost and schedule consequences of particular specifications, the designers and the users revise the specifications.

Directive 5000.29 not only does not encourage this best modern practice, it essentially forbids it. We recommend that it be revised immediately to mandate and facilitate early prototyping before the baseline specifications are established.

DoD STD-2167 likewise needs a radical overhaul to reflect best modern practice. Draft DoD STD 2167A is a step, but it does not go nearly far enough. As drafted, it continues to reinforce exactly the document-driven, specify-then-build approach that lies at the heart of so many DoD software problems.
Some uses of truncated Boolean vectors in analysis
Authors: Smith Howard J.
Published: January 2007

The truncated first occurrence vector (TFOV) is a data construct which the author has found useful in a variety of application areas. It is based on comparisons of adjacent items in a set ordered by some criterion.

The use of the TFOV and its several derivatives improve efficiency and reduce the load on system resources. A contributing factor in performance improvement is the algorithm used in the APL implementations of monadic grade and its offshoot dyadic grade. It is interesting to note that an ordered set improves the efficiency of processes other than those utilizing the TFOV. Calculation of the range and median of a numeric set is an example of this.

As new primitives have been added to APL, construction and generation of the TFOV has been simplified. The paper shows both the early and the later idioms used in programs. The techniques for calculating frequency distributions and the related statistical mode or modes are shown. The development of sub-totals by group in simple (single criterion) and hierarchical cases are illustrated. The generation of (ordered) defining subsets and “arrival” and “departure” sequences are shown. Along with the ordered defining subset (ODS) a pointer to the ODS can be developed. This technique has been found useful in applications requiring data compaction.

The TFOV has proven useful in the development of control vectors for formatting tables especially for insertion of sub-total. A function for pagination of documents which eliminates “widows” has been developed, as have functions for reformatting paragraphs in text processing. In these latter cases, while the ordering algorithm is simply that of position, the concept is a direct outgrowth of experience with the TFOV.

The techniques and concepts discussed in this paper are not intended to be exhaustive but are intended to stimulate programmers in considering an approach often overlooked. It is interesting to note that, while these ideas are applicable in other languages, their recognition required the primitives and arrays of APL.
CAPTURE
Authors: Helmy Ahmed
Published: January 2007

Queries and small transfers are likely to constitute a significant portion of the flows in emerging classes of sensor networks. Route discovery for such queries incurs much more communication overhead than the actual data transfer. Especially for large-scale sensor networks, it is quite costly to establish shortest path routes for such types of requests. Flooding-based approaches for routing are designed to search for high quality routes. Such approaches may be suitable for prolonged transfers, but not for small ones. In this paper, we present an architecture that is geared towards one-shot frequent queries in sensor networks. In our approach we aim at reducing the total energy cost query resolution as opposed to searching for high quality routes.Our architecture uses a hybrid approach, where each node collects information about nodes in its proximity, up to R hops away, using a link state protocol. Beyond the proximity, we introduce the novel notion of contacts that act as short cuts to reduce the degrees of separation between the request source and the target. A new efficient, on-demand, contact selection protocol is integrated into the search process. We do not assume knowledge of node locations. Several protocols to implement different policies for the search are introduced. Extensive simulations are used to systematically evaluate the performance of our protocols. Our results show substantial communication overhead reduction for our contact-based technique as compared to related schemes. The study also shows reasonable settings of parameters that work well for a wide range of networks.
On call admission and performance evaluation for multiservice CDMA networks
Authors: Bo Xiaoming , Chen Zujue
Published: January 2007

Call admission control and performance evaluation in wireless communication networks are essential for system design and operation. The network capacity and admissibility of imperfectly power-controlled multiservice code division multiple access (CDMA) system are studied in this paper. A generalized capacity formula considering traffic activity is derived, based on which a handoff prioritized call admission policy is presented and evaluated using the K-dimensional birth-death process model. System performance in terms of blocking probabilities, resource utilization and average system throughput are demonstrated and discussed in detail as the traffic intensity increases. It is also shown that the system parameters such as outage probability constraint and power control error have great impact on system capacity and performance. Since this work is based on the imperfect power control model, it is more appropriate to the design of practical multiservice CDMA networks.
Gene ranking using bootstrapped P-values
Authors: Mukherjee S. N. , Roberts S. J. , Sykacek P. , Gurr S. J.
Published: January 2007

Recent research has shown that it is possible to find genes involved in the pathogenesis of a particular condition on the basis of microarray experiments. Genes which are differentially expressed, for example between healthy and diseased tissues, are likely to be relevant to the disease under study. Some of the properties of microarray datasets make the task of finding these genes a challenging one. This paper proposes a gene-ranking algorithm whose main novelty is the use of bootstrapped P-values. We present an analysis of the algorithm, showing how it takes account of small-sample variability in observed values of the test statistic, in a way conventional statistical tests cannot. Experimental results show that our algorithm outperforms the widely-used two-sample
t
-test on challenging artificial data. Gene ranking is then performed on two well-known microarray datasets, with encouraging results. For example, a number of genes from one of the datasets, whose differential expression was subsequently confirmed by a more reliable biochemical analysis, are found to be ranked higher by the bootstrapped algorithm than by the conventional
t
-test, suggesting that the proposed algorithm may be better able to exploit the limited data available to infer biologically useful information.
Machine learning methods applied to DNA microarray data can improve the diagnosis of cancer
Authors: Bair Eric , Tibshirani Robert
Published: January 2007

The morbidity rate of cancer victims varies greatly for similar patients who receive similar treatments. It is hypothesized that this variation can be explained by the genetic heterogeneity of the disease. DNA Microarrays, which can simultaneously measure the expression level of thousands of different genes, have been successfully used to identify such genetic differences. However, microarray data typically has a large number of features and relatively few observations, meaning that conventional machine learning tools can fail when applied to such data. We describe a novel procedure called "nearest shrunken centroids" that has successfully detected clinically relevant genetic differences in cancer patients. This procedure has the potential to become a powerful tool for diagnosing and treating cancer.
"In vivo" spam filtering
Authors: Fawcett Tom
Published: January 2007

Spam, also known as Unsolicited Commercial Email (UCE), is the bane of email communication. Many data mining researchers have addressed the problem of detecting spam, generally by treating it as a static text classification problem. True
in vivo
spam filtering has characteristics that make it a rich and challenging domain for data mining. Indeed, real-world datasets with these characteristics are typically difficult to acquire and to share. This paper demonstrates some of these characteristics and argues that researchers should pursue
in vivo
spam filtering as an accessible domain for investigating them.
Resolving citations in a paper repository
Authors: Sarawagi Sunita , Vydiswaran V. G. Vinod , Srinivasan Sumana , Bhudhia Kapil
Published: January 2007

In this paper, we describe our process of creating a citation graph from a given repository of physics publications in LATEX format. The task involved a series of information extraction, data cleaning, matching and ranking steps. This paper describes the challenges we faced along the way and the issues involved in resolving them.
Model Builder for Predictive Analytics & Fair Isaac's approach to KDD Cup 2003
Authors: Carleton Joel , Hartnett Daragh , Milana Joseph , Momma Michinari , Sirosh Joseph , Surpi Gabriela
Published: January 2007

Fair Isaac tackled the third task of KDD Cup 2003 using a predictive modeling approach that leveraged citation graphs, text mining, custom variable creation and linear regression. The core tools we used were embedded in our Model Builder for Predictive Analytics (MBPA) product that makes commercially available a broad set of previously proprietary methodologies used by Fair Isaac for predictive scoring systems such as credit risk and credit card fraud. This short paper reviews the KDD cup problem our approach, and the toolset. We analyze the predictive variables in the model, the main sources of prediction errors, and the steps that could be taken to alleviate such errors in future work.
Editing requirements for data base applications and their implementation on the INDY backend kernel
Authors: Otis Allen J. , Copeland George P.
Published: January 2007

An extrapolation of user and hardware cost trends indicate that future systems should provide more complete functionality, simplicity of use, and reliability by increasing the amount of hardware present in the system. For data base systems, this can be done by providing very high level data languages and by implementing them directly in hardware. These goals are realized with a simple hardware arrangement called INDY, which uses inexpensive memory technologies (such as charge coupled devices, magnetic bubbles, or discs). This paper first discusses the data definition and editing requirements of data languages. Then the implementation of these requirements on the INDY backend kernel is described. Finally, a comparison is made of the various memory technologies for suitability to INDY.
Bubbles for relational database
Authors: Chang Hsu
Published: January 2007

The mechanical disk storage is limited by long initial delay, few inputs/outputs, and serial access, thus necessitating large complex programs in existing database systems in order to map the user's view into the physical storage and to provide different access paths in response to different queries. Bubble devices are capable of set-oriented processing and associative addressing architecture. This paper presents concepts on data structure, storage structure, and access methods for bubble implementation of relational database.
A performance evaluation of a general parallel processing model
Authors: Nelson Randolph
Published: January 2007

In this paper we analyze a model of a parallel processing system. In our model there is a single queue which is
K
≥ 1 identical processors. Jobs are assumed to consist of a sequence of barrier synchronizations where, at each step, the number of tasks that must be synchronized is random with a known distribution. An exact analysis of the model is derived. The model leads to a rich set of results characterizing the performance of parallel processing systems. We show that the number of jobs concurrently in execution, as well as the number of synchronization variables, grows linearly with the load of the system and strongly depends on the average number of parallel tasks found in the workload. Properties of expected response time or such systems are extensively analyzed and, in particular, we report on some non-obvious response time behavior that arises as a function of the variance of parallelism found in the workload. Based on exact response time analysis, we propose a simple calculation that can be used as a rule of thumb to predict speedups. This can be viewed as a generalization of Amdahl's law that includes queueing effects. This generalization is reformulated when precise workloads cannot be characterized, but rather when only the fraction or sequential work and the average number of parallel tasks arc assumed to be known.
Efficient trace-driven simulation method for cache performance analysis
Authors: Wang Wen-Hann , Baer Jean-Loup
Published: January 2007

We propose improvements to current trace-driven cache simulation methods to make them faster and more economical. We attack the large time and space demands of cache simulation in two ways. First, we reduce the program traces to the extent that exact performance can still be obtained from the reduced traces. Second, we devise an algorithm that can produce performance results for a variety of metrics (hit ratio, write-back counts, bus traffic) for a large number of set-associative write-back caches in just a single simulation run. The trace reduction and the efficient simulation techniques are extended to parallel multiprocessor cache simulations. Our simulation results show that our approach substantially reduces the disk space needed to store the program traces and can dramatically speedup cache simulations and still produce the exact results.
An advisor for flexible working sets
Authors: Alonso Raphael , Appel Andrew W.
Published: January 2007

The traditional model of virtual memory working sets does not account for programs that can adjust their working sets on demand. Examples of such programs are garbage-collected systems and databases with block cache buffers. We present a memory-use model of such systems, and propose a method that may be used by virtual memory managers to advise programs on how to adjust their working sets. Our method tries to minimize memory contention and ensure better overall system response time. We have implemented a memory “advice server” that runs as a non-privileged process under Berkeley Unix. User processes may ask this server for advice about working set sizes, so as to take maximum advantage of memory resources. Our implementation is quite simple, and has negligible overhead, and experimental results show that it results in sizable performance improvements.
Analysis of critical architectural and programming parameters in a hierarchical
Authors: Torrellas Joseph , Hennessy John , Weil Thierry
Published: January 2007

Scalable shared-memory multiprocessors are the subject of much current research, but little is known about the performance behavior of these machines. This paper studies the performance effects of two machine characteristics and two program characteristics that seem to be major factors in determining the performance of a hierarchical shared-memory machine. We develop an analytical model of the traffic in a machine loosely based on Stanford's DASH multiprocessor and use program parameters extracted from multiprocessor traces to study its performance. It is shown that both locality in the data reference stream and the amount of data sharing in a program have an important impact on performance. Although less obvious, the bandwidth within each cluster in the hierarchy also has a significant performance effect. Optimizations that improve the intracluster cache coherence protocol or increase the bandwidth within a cluster can be quite effective.
Challenges in obtaining peak parallel performance with a Convex C240, parallel vector processor
Authors: McGehearty Patrick F.
Published: January 2007

This report examines the behavior of the Linpack 300×300 benchmark [Dongarra] on a parallel vector machine. It is observed that the performance of several parallel vector machines on this application is far below their nominal peak performance. Dissection of the internals of the algorithms shows how peak performance is limited. The insights gained provide guidance to algorithm developers as to ways to make maximum use of architectural strengths. System architects may gain insight about which system characteristics to optimize to increase the performance of future designs for this class of application.
Interpolation in symbolic summation
Authors: Caruso Fabrizio
Published: January 2007

We present two software packages for computing the null space of a matrix with rational function coefficients. We use two approaches based on classical interpolation algorithms. The packages are written in the Mathematica language.In the first package we use polynomial interpolation and Cramer's rule to reconstruct the components of the solutions. This package works under some assumptions on the matrix that, in most cases, are true for systems involved in Zeilberger's algorithm for hypergeometric definite summation.In the second package we use a hybrid method based on heuristic rational function interpolation on some low degree components of the solutions and "symbolic" Gaussian elimination on the other components. The second package works under very general conditions and can be customized for systems related to symbolic summation.
Validated numerical methods for systems and control engineering
Authors: Kanno Masaaki , Smith Malcolm C.
Published: January 2007

The aim of this research is to investigate the development of numerical methods for systems and control which have a guarantee on accuracy. An end-product of such research is an algorithm which could be described as "infallible" in the following sense: the user would specify
a priori
a tolerance as small as desired, and the computer would provide an answer which was guaranteed to be accurate to the specified tolerance. Though this is an established subject within Computer Science [5], as well as a few application areas in science and engineering (see [1, Part III]), the direction appears to be quite new in the control systems area. A characteristic feature of previous work is the application of computer algebra tools and the avoidance of floating-point arithmetic.
On optimization problems
Authors: Tian-Jiao Wu
Published: January 2007

Let
R
= real field,
X
= (
x
1
,
x
2
,......,

x
n

),
D
a domain in
R

n

(
X
),
f
,

g
i

,

h
i

in
R
[X].
Simulation game for managing the laboratory sevice
Authors: Hogan Andrew
Published: January 2007

The goal of this research is to develop, test, and implement a simulation game capable of assisting VA laboratory decision makers in planning program changes, altering systems and procedures, determining staffing levels based on variable demands for service, rearranging space utilization and/or evaluating possible equipment acquisitions. The secondary goal is to teach laboratory management skills to supervisory personnel. The simulation game will be designed to process the kinds of information generated by the new VA computer based management information systems (MIS). It is expected that development of the game at this time will aid in the definition of the laboratory MIS.A principal feature of the model will be its transferability to any VA Medical Center. To this end, parts of the simulation game will be developed at 2 different sites. Upon completion, these parts will be joined into a single model and tested in a third medical center. Personnel from Medical District 14 and the Laboratory Management Consultation Program at the Centers for Disease Control will evaluate the transferability of the game among VAMCs.
Model instantiation for query driven simulation in active KDL
Authors: Miller John A. , Potter Walter D. , Kochut Krys J. , Weyrich Orville R.
Published: January 2007

The focus of this paper is on how Active KDL can be used to provide a very powerful simulation support environment. Active KDL (Knowledge/Data Language) is an object-oriented database programming language, which provides access to integrated
model, knowledge
, and
data bases
. Simulation inputs and outputs can be stored by Active KDL since it supports complex objects. More importantly, Active KDL also allows users to specify rules to capture heuristic knowledge and methods to specify procedural behavior. Finally, Active KDL provides a simple mechanism for specifying concurrent execution, namely tasks embedded in active objects. These facilities provide a powerful mechanism for building simulation models out of pre-existing model components. These capabilities provide a tight coupling between a SIMODULA-like simulation system and a knowledge/database system, supporting query driven simulation, where model instantiation is used for information generation.
Modeling the cost of resource allocation in distributed control
Authors: Fraser Martin D. , Gagliano Ross A. , Schaefer Mark E.
Published: January 2007

Modifying our previously developed simulation model [FRA89], we study in this paper the costs associated with distributed allocation of computing resources in a multitasking environment. Using funds endowed upon arrival, computing tasks compete for necessary resources through sealed-bid auctions to improve their processing schedules. The costs and times dedicated to auctioning are compared to the costs and times allowed for task processing. Measuring computing resources in terms of processing rates allows the task management, in the form of an auction, algorithm, to have its requirements specified in the same way as the requirements for the simulated mission processing. Machine capacity is computed for and assigned to each completing task. Data are then compiled by segmented capacity classes. A unifying theme of past and current research is the efficiency of auctioning to allocate reconfigurable computing resources in a variable capacity machine. We observed that at optimal rates of occurrence of capacity classes which minimize the total costs per successful completion, congestion was resolved through auctions generating endogenously implied prices which substantially exceeded the exogenously imposed price.
Electric-field-based routing
Authors: Nguyen Nam T. , Wang An-I Andy , Reiher Peter , Kuenning Geoff
Published: January 2007

Constructing multipath routes in MANETs is important for providing reliable delivery, load balancing, and bandwidth aggregation. However, popular multipath routing approaches fail to produce spatially disjoint routes in a simple and cost-effective manner, and existing single-path approaches cannot be easily modified to produce multiple disjoint routes. In this paper we propose Electric-Field-Based Routing (EFR) as a reliable framework for routing in MANETs by applying the concept of electric field lines. Our location-based protocol naturally provides spatially disjoint routes based on the shapes of these lines. The computation is highly localized and requires no explicit coordination among routes. EFR can also be easily extended to offer load-balancing, bandwidth aggregation, and power management. Through simulation, EFR shows a higher delivery ratio and lower overhead under high mobility, high network loads, and network failures compared to popular multipath and location-based schemes. EFR also demonstrates high resiliency to DoS attacks.
Abnormal muscle and hematopoietic gene expression may be important for clinical morbidity in primary hyperparathyroidism
Authors: Reppe Sjur , Stilgren Lis , Abrahamsen Bo , Olstad Ole K. , Cero Fadila , Brixen Kim , Nissen-Meyer Lise Sofie , Gautvik Kaare M.
Published: January 2007

In primary hyperparathyroidism (PHPT), excess PTH secretion by adenomatous or hyperplastic parathyroid glands leads to elevated serum [Ca2+]. Patients present complex symptoms of muscular fatigue, various neuropsychiatric, neuromuscular, and cardiovascular manifestations, and, in advanced disease, kidney stones and metabolic bone disease. Our objective was to characterize changes in muscle and hematopoietic gene expression in patients with reversible mild PHPT after parathyroidectomy and possibly link molecular pathology to symptoms. Global mRNA profiling using Affymetrix gene chips was carried out in biopsies obtained before and 1 yr after parathyroidectomy in seven patients discovered by routine blood [Ca2+] screening. The tissue distribution of PTH receptor (PTHR1 and PTHR2) mRNAs were quantitated using real-time RT-PCR in unrelated persons to define PTH target tissues. Of about 10,000 expressed genes, 175 muscle, 169 hematological, and 99 bone-associated mRNAs were affected. Notably, the major part of muscle-related mRNAs was increased whereas hematological mRNAs were predominantly decreased during disease. Functional and molecular network analysis demonstrated major alterations of several tissue characteristic groups of mRNAs as well as those belonging to common cell signaling and major metabolic pathways. PTHR1 and PTHR2 mRNAs were more abundantly expressed in muscle and brain than in hematopoietic cells. We suggest that sustained stimulation of PTH receptors present in brain, muscle, and hematopoietic cells have to be considered as one independent, important cause of molecular disease in PHPT leading to profound alterations in gene expression that may help explain symptoms like muscle fatigue, cardiovascular pathology, and precipitation of psychiatric illness.
EGCG, a green tea polyphenol, improves endothelial function and insulin sensitivity, reduces blood pressure, and protects against myocardial I/R injury in SHR
Authors: Potenza Maria A. , Marasciulo Flora L. , Tarquinio Mariela , Tiravanti Edy , Colantuono Giuseppe , Federici Antonio , Kim Jeong-a , Quon Michael J. , Montagnani Monica
Published: January 2007

Epigallocatechin gallate (EGCG), a bioactive polyphenol in green tea, may augment metabolic and vascular actions of insulin. Therefore, we investigated effects of EGCG treatment to simultaneously improve cardiovascular and metabolic function in spontaneously hypertensive rats (SHR; model of metabolic syndrome with hypertension, insulin resistance, and overweight). In acute studies, EGCG (1–100 μM) elicited dose-dependent vasodilation in mesenteric vascular beds (MVB) isolated from SHR ex vivo that was inhibitable by Nω-nitro-l-arginine methyl ester (l-NAME; nitric oxide synthase antagonist) or wortmannin [phosphatidylinositol (PI) 3-kinase inhibitor]. In chronic studies, 9-wk-old SHR were treated by gavage for 3 wk with EGCG (200 mg·kg−1·day−1), enalapril (30 mg·kg−1·day−1), or vehicle. A separate group of SHR receiving l-NAME (80 mg/l in drinking water) was treated for 3 wk with either EGCG or vehicle. Vasodilator actions of insulin were significantly improved in MVB from EGCG- or enalapril-treated SHR (when compared with vehicle-treated SHR). Both EGCG and enalapril therapy significantly lowered systolic blood pressure (SBP) in SHR. EGCG therapy of SHR significantly reduced infarct size and improved cardiac function in Langendorff-perfused hearts exposed to ischemia-reperfusion (I/R) injury. In SHR given l-NAME, beneficial effects of EGCG on SBP and I/R were not observed. Both enalapril and EGCG treatment of SHR improved insulin sensitivity and raised plasma adiponectin levels. We conclude that acute actions of EGCG to stimulate production of nitric oxide from endothelium using PI 3-kinase-dependent pathways may explain, in part, beneficial effects of EGCG therapy to simultaneously improve metabolic and cardiovascular pathophysiology in SHR. These findings may be relevant to understanding potential benefits of green tea consumption in patients with the metabolic syndrome.
Granular Cells of the Mormyrid Electrosensory Lobe and Postsynaptic Control Over Presynaptic Spike Occurrence and Amplitude Through an Electrical Synapse
Authors: Zhang Jianmei , Han Victor Z. , Meek Johannes , Bell Curtis C.
Published: January 2007

Primary afferent fibers from the electroreceptors of mormyrid electric fish use a latency code to signal the intensity of electrical current evoked by the fish's own electric organ discharge (EOD). The afferent fibers terminate centrally in the deep and superficial granular layers of the electrosensory lobe with morphologically mixed chemical–electrical synapses. The granular cells in these layers seem to decode afferent latency through an interaction between primary afferent input and a corollary discharge input associated with the EOD motor command. We studied the physiology of deep and superficial granular cells in a slice preparation with whole cell patch recording and electrical stimulation of afferent fibers. Afferent stimulation evoked large all-or-none electrical excitatory postsynaptic potentials (EPSPs) and large all or none GABAergic inhibitory postsynaptic potentials (IPSPs) in both superficial and deep granular cells. The amplitudes of the electrical EPSPs depended on postsynaptic membrane potential, with maximum amplitudes at membrane potentials between −65 and −110 mV. Hyperpolarization beyond this level resulted in either the abrupt disappearance of EPSPs, a step-like reduction to a smaller EPSP, or a graded reduction in EPSP amplitude. Depolarization to membrane potentials lower than that yielding a maximum caused a linear decrease in EPSP amplitude, with EPSP amplitude reaching 0 mV at potentials between −55 and −40 mV. We suggest that the dependence of EPSP size on postsynaptic membrane potential is caused by close linkage of pre- and postsynaptic membrane potentials through a high-conductance gap junction. We also suggest that this dependence may result in functionally important nonlinear interactions between synaptic inputs.
Unusually Long Duration, Multiple-Doppler Radar Observations of a Front in a Convective Boundary Layer
Authors: Stonitsch John R. , Markowski Paul M.
Published: January 2007

Dual-Doppler observations acquired by a network of mobile radars deployed in the Oklahoma panhandle on 3 June 2002 are used to document the kinematic structure and evolution of a front. The data were collected during the International H2O Project on a mission to study the initiation of deep convection. Synchronized scanning allowed for the synthesis of three-dimensional wind fields for nearly 5.5 h of the 1557–0000 UTC period. The front initially moved southward as a cold front, stalled, and later retreated northward as a warm front. Deep convection failed to be initiated along the front. In situ thermodynamic measurements obtained by a mobile mesonet were used to document changes in the density gradient at the surface. This paper examines the relationships among the changes in baroclinity, the thermally direct frontal circulation, updraft intensity, alongfront updraft variability, and the intensity of vortices along the front.

Increases in the front-normal density gradient tended to be associated with increases in the thermally direct frontal circulation, as expected. Increases in the front-normal density gradient were also associated with an increase in the tilt of the frontal updraft as well as an increase in the contiguity of the updraft along the front, termed the “slabularity.” During periods when the front-normal density gradient and associated thermally direct frontal circulation were weak, the kinematic fields were dominated by boundary layer convection and the slabularity of the front was reduced. Intensification of the front-normal density gradient was accompanied by an increase in the horizontal wind shear and the intensity of vortices that were observed along the front. The vortices modulated the vertical velocity field along the front and therefore the slabularity, too. Thus, although the slabularity was a strong function of the strength of the thermally direct frontal circulation, the slabularity appeared to be modified by vortices in complex ways. Possible implications of the observations for convection initiation are also discussed, particularly with respect to updraft tilt and slabularity.
On the Theoretical Equivalence of Differently Proposed Ensemble–3DVAR Hybrid Analysis Schemes
Authors: Wang Xuguang , Snyder Chris , Hamill Thomas M.
Published: January 2007

Hybrid ensemble–three-dimensional variational analysis schemes incorporate flow-dependent, ensemble-estimated background-error covariances into the three-dimensional variational data assimilation (3DVAR) framework. Typically the 3DVAR background-error covariance estimate is assumed to be stationary, nearly homogeneous, and isotropic. A hybrid scheme can be achieved by 1) directly replacing the background-error covariance term in the cost function by a linear combination of the original background-error covariance with the ensemble covariance or 2) through augmenting the state vector with another set of control variables preconditioned upon the square root of the ensemble covariance. These differently proposed hybrid schemes are proven to be equivalent. The latter framework may be a simpler way to incorporate ensemble information into operational 3DVAR schemes, where the preconditioning is performed with respect to the background term.
An Adaptive Vertical Coordinate Formulation for a Nonhydrostatic Model with Flux-Form Equations
Authors: Zängl Günther
Published: January 2007

The concept of adaptive vertical coordinates is used to upgrade conventional terrain-following σ coordinates to arbitrary hybrid coordinates. Compared with previous approaches for implementing adaptive coordinates, the method presented here combines unrestricted applicability to nonhydrostatic models with the capability to integrate the atmospheric equations in flux form. The coordinate is based on a three-dimensional field carrying the vertical position of the coordinate surfaces, which is made time dependent by introducing a prognostic equation. As a specific example, the adaptive coordinate is used to emulate a hybrid isentropic system. Idealized tests in which the coordinate surfaces are artificially moved reveal that the ensuing spurious motions are small enough to be negligible in realistic applications. Mountain wave tests demonstrate that the hybrid coordinate remains numerically stable under strong forcing. However, the model layer distribution established with the hybrid isentropic coordinate is not optimal for representing the dynamics of breaking gravity waves because the vertical distance between the model levels tends to be too large in the wave breaking region. On the other hand, real case studies demonstrate that the hybrid coordinate significantly improves the representation of the tropopause because of enhanced vertical resolution in the tropopause region.
The Scientist-Practitioner Model
Authors: Horn Robert A. , Troyer Julie A. , Hall Elizabeth J. , Mellott Ramona N. , Coté L. Sue , Marquis Jeffrey D.
Published: January 2007

This study reviews the continued debate concerning the scientist-practitioner model as a best practice/best approach to training future professionals. However, to begin such an investigation of the fundamental questions regarding the model, researchers must have a starting point. The current study serves as a catalyst for future research, investigating the reported level of use of the model by surveying Web-based program materials from more than 300 doctorate-level programs in school psychology, counseling psychology, and clinical psychology. Results show more than one half of all programs surveyed make specific mention of the model of training. Nearly all have some reference to scholarly research expectations and to training of practitioners. Emphasis of scholarly research is further supported by nearly two thirds of the programs mentioning a requirement of a dissertation. Emphasis of practitioner training is shown by an overwhelming majority of the programs’ indicating practica, internship, or fieldwork as a requirement.
Reliability and Validity of the Greek Version of the Derogatis Psychiatric Rating Scale (DPRS)
Authors: Vorvolakos Theofanis , Samakouri Maria , Xenitidis Kiriakos , Perentzi Maria , Tzavaras Nikos , Livaditis Miltos
Published: January 2007

Background: The aim of this paper is to report on the Greek version of the Derogatis Psychiatric Rating Scale (DPRS) and its validity and reliability when administered to a Greek sample. The DPRS is a clinician-rated measure of psychiatric symptoms with nine basic and eight complementary symptom dimensions and a Global Pathology Index.

Method: The DPRS was translated into Greek and administered to 161 psychiatric patients and healthy volunteers. Its validity was assessed against the Semi-structured Clinical Interview (SCID) and the Symptoms Checklist-90-Revised (SCL-90-R). The inter-rater reliability and test-retest reliability were also evaluated for each symptom dimension.

Results: All the symptom dimensions of the DPRS, except euphoria, have concurrent validity with the SCID on the relevant symptom dimensions diagnoses set by the interview. At the cut-off point 2/3 the DPRS has a sensitivity of 98% and a specificity of 74% in indicating active psychiatric patients. The symptom dimensions of the DPRS also have strong correlations with the relevant dimensions of SCL-90-R. The range for inter-rater reliability was from 0.48 to 0.88, the range for test-retest reliability was from 0.25 to 0.85, and the internal consistency was 0.90.

Conclusion: The Greek version of the DPRS has acceptable psychometric properties, rendering it a useful screening instrument of global psychopathology as well as a multidimensional measure of some basic psychiatric symptoms.
Brief Communication: Differences Between Ethnic Groups in Demographic and Clinical Features of Patients Admitted and Assessed After Deliberate Self-Harm: A Retrospective Case-Note Study
Authors: Bhogal Kuljit , Baldwin David , Hartland Louise , Nair Rajesh
Published: January 2007

Background to the study: When compared to the United Kingdom general population, rates of deliberate self-harm (DSH) are increased among certain ethnic groups, particularly in those from the Indian diaspora.

Aim: To investigate differences between ethnic groups in the demographic and clinical features of patients admitted after episodes of DSH and subsequently assessed by a nurse-led DSH liaison team.

Method: A retrospective case-note study ( N = 297) with completion of a standardized data collection instrument. The ethnic origin of each patient was assessed by a variety of means.

Results: Asian patients ( n = 38) were more likely to be female ( p = 0.043), married ( p = 0.027), and cite problems with their partner ( p = 0.017) as a precipitant to DSH. The indigenous group ( n = 234) were more likely to have previous contact with psychiatric services ( p = 0.023), to have used alcohol preceding DSH ( p = 0.014), and to have a criminal record ( p = 0.007).

Conclusions: In this population, the demographic and clinical features of patients assessed after DSH vary significantly with ethnic group. A case-control study is warranted to examine these differences in more detail.
Demoralisation - A Useful Conceptualisation of Non-Specific Psychological Distress Among Refugees Attending Mental Health Services
Authors: Briggs Lynne , Macleod A. D. (Sandy)
Published: January 2007

Background: While it is recognised that many refugee and migrant clients present at mental health services with non-specific psychological distress little is known about successful intervention strategies.

Aims: The aim of this study was to systematically review clinical files to determine the degree of ‘demoralisation’ symptoms among a sample of refugee and migrant clients attending a community-based mental health service.

Method: Sixty-four closed cases were reviewed using a specifically designed case review sheet as a checklist which included diagnostic criteria for a Demoralisation Syndrome.

Results: The findings indicated that while many of the refugee and migrant clients had attracted a diagnosis of major depressive disorder, in the main they did not benefit from a normal course of treatment. Further analysis suggested that demoralisation may be a preferable concept for many of these clients rather than affective disorder. This finding suggests that demoralisation may be a different construct than low mood or depression.

Conclusions: The findings add support to the concept that demoralisation could be a distinct diagnostic entity in its own right that may be useful to clinicians attending refugee and migrant clients.
Expert and Lay Explanations of Suicidal Behaviour: Comparison of the General Population’s, Suicide Attempters’, General Practitioners’ and Psychiatrists’ Views
Authors: Zadravec Tina , Grad Onja , Sočan Gregor
Published: January 2007

Background: Different explanations of suicidal behaviour coexist today. The incompatibility of the beliefs among experts and (potential) users of medical services can influence the implementation of prevention programmes, help-seeking behaviour and adherence to treatment.

Aims: The aims of the study were to identify explanatory models of suicidal behaviour and to determine possible incompatibilities between lay (the general population and suicide attempters) and expert (the general practitioners and psychiatrists) views.

Methods: The Questionnaire on Attitudes towards Suicide was revised on the basis of semi-structured interviews with the general population, suicide attempters, general practitioners and psychiatrists. The revised version was then applied to each of these four groups.

Results: Five explanatory models were identified: namely, personality, sociological, medical, crisis and genetic models. Significant group differences on the explanatory models were found. The lay people favoured crisis, sociological and medical models whereas the experts shared the belief in the medical, genetic and crisis models.

Conclusions: The crisis model gained considerable support and was generally accepted as correct. This could be the common ground between lay people and experts and the starting point of both treatment and prevention programmes.
Trade Union Recognition in Britain: An Emerging Crisis for Trade Unions?
Authors: Gall Gregor
Published: January 2007

This article examines recent developments in union recognition in Britain and assesses the influence of the statutory union recognition provisions contained in the Employment Relations Act 1999 upon the gaining of union recognition and the capacity of unions to take advantage of this more favourable legal environment. It details the significant increase in new union recognition agreements, concluding that the new law is one among a number of factors explaining this growth. However, the impact of the rise in new agreements is found to have made a negligible impact on aggregate union recognition coverage, indicating the limitations to union capacity to significantly increase coverage with a more favourable environment at hand.
Britain and Individual Employment Rights: ‘Paper Tigers, Fierce in Appearance but Missing in Tooth and Claw’
Authors: Pollert Anna
Published: January 2007

There is much evidence that the ‘European social model’ is under threat, with neoliberalism increasingly dominating policy both at EU and national levels. Within this trend, Britain stands out as already having a long-established free market tradition-Anglo-American in both industrial relations and corporate governance systems. This article seeks to illustrate how British state allegiance to a ‘flexible’ labour market has brought new restrictions to accessing statutory employment protection, the chief defence for ‘unorganized’ workers those who are neither unionized nor covered by collective agreements and who now comprise the majority of workers in Britain. The New Labour government, committed to voluntarism and fiexibility, has used the very instrument it avers to avoid legal regulation to limit access to employment tribunals, the final resort for legal enforcement of employment rights. The government has thus constrained its concessions to the European social model, which comprise a range of laws since 1997 enhancing individual employment rights, in its overarching neoliberal policy, by ensuring legal regulation remains difflcult to achieve and does not ‘burden’ business. This article, based on research both on legal developments, and on the social support mechanisms for non-unionized workers, seeks to demonstrate the extreme vulnerability of the unorganized worker in an increasingly free market Britain. How far this portrait has relevance to the rightward drift of Europe depends on the degree to which it can be exported, how far continental European systems are sufflciently institutionally embedded to resist this, and how successfully the European social model is defended.