Use of health services for anxiety disorders: a multisite study in Quebec

OBJECTIVE: We investigated patient characteristics and use of services for anxiety disorders among patients seeking care from participating clinicians at 7 anxiety clinics in Quebec: 3 general hospital clinics, 3 psychologist-run clinics, and one psychiatric hospital clinic. METHODS: Persons eligible for the study were those who were visiting the clinics for the first time, had a current diagnosis of an anxiety disorder, and could communicate in French or English. Subjects recruited through advertisements were excluded. Data, collected by a self-administered questionnaire, included demographics, treatment history, use of services for anxiety, and the Beck Anxiety Inventory (BAI). RESULTS: The sample comprised 235 subjects: 146 seen at 3 general hospital clinics, 54 at 3 psychologist-run clinics, and 35 at a psychiatric hospital clinic. There were statistically significant differences by clinic type in the prevalence of specific anxiety diagnoses, BAI score, referral source, antidepressant use, and use of services. High-intensity use (10 or more consultations during the previous year) was reported by 23.4% of the sample for medical services and 19.6% for mental health services. Multiple logistic regression identified variables associated with high-intensity use of medical services (higher BAI score, 1 to 4 years since first sought treatment, and less than 12 years of education) and high-intensity use of mental health services (clinic type, obsessive-compulsive disorder [OCD], and 5 or more years since first sought treatment). CONCLUSIONS: The patient populations seen at different types of anxiety clinics differ in several respects, including referral source, previous treatment, and severity of symptoms. Regardless of type of clinic, patients with a longer time since they first sought treatment use more services, particularly mental health services. Those with less education use more medical services than those with greater education.     

The binding of receptor-recognized alpha2-macroglobulin to the low density lipoprotein receptor-related protein and the alpha2M signaling receptor is decoupled by oxidation

Receptor-recognized forms of alpha2-macroglobulin (alpha2M*) bind to two classes of cellular receptors, a high affinity site comprising approximately 1500 sites/cell and a lower affinity site comprising about 60,000 sites/cell. The latter class has been identified as the so-called low density lipoprotein receptor-related protein (LRP). Ligation of receptors distinct from LRP activates cell signaling pathways. Strong circumstantial evidence suggests that the high affinity binding sites are responsible for cell signaling induced by alpha2M*. Using sodium hypochlorite, a powerful oxidant produced by the H2O2-myeloperoxidase-Cl- system, we now demonstrate that binding to the high affinity sites correlates directly with activation of the signaling cascade. Oxidation of alpha2M* using 200 microM hypochlorite completely abolishes its binding to LRP without affecting its ability to activate the macrophage signaling cascade. Scatchard analysis shows binding to a single class of high affinity sites (Kd - 71 +/- 12 pM). Surprisingly, oxidation of native alpha2-macroglobulin (alpha2M) with 125 microM hypochlorite results in the exposure of its receptor-binding site to LRP, but the ligand is unable to induce cell signaling. Scatchard analysis shows binding to a single class of lower affinity sites (Kd - 0.7 +/- 0.15 nM). Oxidation of a cloned and expressed carboxyl-terminal 20-kDa fragment of alpha2M (RBF), which is capable of binding to both LRP and the signaling receptor, results in no significant change in its binding Kd, supporting our earlier finding that the oxidation-sensitive site is predominantly outside of RBF. Attempts to understand the mechanism responsible for the selective exposure of LRP-binding sites in oxidized native alpha2M suggest that partial protein unfolding may be the most likely mechanism. These studies provide strong evidence that the high affinity sites (Kd - 71 pM) are the alpha2M* signaling receptor.     

Performance based on selective multipath reception

As wireless data rate requirements increase, multipath delay spread becomes an increasingly significant limitation on the performance of wireless systems. Techniques such as RAKE reception combat time dispersion by combining multipath components. Alternative implementations of RAKE receivers isolate the strongest multipath components and then shift each component to a common timing reference. The optimal timing reference in frequency-selective fading channels remains an open problem. This paper examines the impact pulse shaping and multipath delay spread on both signal-to-noise ratio (SNR) and bit-error rate performance. The receiver being considered achieves symbol synchronization to the strongest multipath component. The performance when synchronization is achieved based on the first multipath component arrival is also found and used to illustrate performance differences. Multipath delay distributions used on the performance calculations are derived from indoor measurements. Pulse shapes considered in the analysis include root-raised cosine, raised cosine, and Gaussian filters. SNR losses are shown to range between 1-6 dB for bit rates of 10 Mb/s. Results show that synchronization of the receiver to the strongest multipath component gives a 1-3 dB advantage over synchronization to the first arriving multipath component.     

Audio watermarking under desynchronization and additive noise attacks

Digital watermarking is often modeled as the transmission of a message over a noisy channel denoted as "watermark channel". Distortions introduced by the watermark channel result mainly from attacks and may include interference from the original signal. One of the main differences with classical transmission situations stems from the fact that perceived distortions have to be taken into account. However, measuring the perceived impact an attack has on a watermarked signal is currently an unsolved problem. Possible means of circumventing this problem would be 1) to define the distortion in a so-called "perceived domain" and define an "ad hoc" equivalence between objective and perceived distortion or 2) to define an "equivalent distortion" by removing from the attack noise the part that is correlated to the host signal. This paper concentrates on the second approach and first shows that the resulting "equivalent" attack is a particular case of a thoroughly studied channel: filtering plus additive noise. However, the approach in this paper emphasizes the fact that the additive noise in the model has to be decorrelated with the signal. Then, the formalism is applied to (desynchronization plus noise) attacks on audio signals. In this context, this paper provides the corresponding capacities, as well as optimal "attack" and "defense" strategies in a game theory context.     

Exploratory analytics on patent data sets using the SIMPLE platform

Exploratory Analytics is the process of analyzing data for the purpose of forming hypotheses. Patent data sets, because they are relatively large and diverse and because they consist of a mixture of structured and unstructured information present a formidable challenge and a great opportunity in applying exploratory analytics techniques. In this paper we describe methods we have implemented for effective exploratory analytics on patent data sets using an interactive approach and a web based software tool called SIMPLE. We use real-world case studies to demonstrate the effectiveness of our exploratory analytics approach in the discovery of useful information from the patent corpus.     

Quantized based image watermarking in an independent domain

This paper presents a performance study for two well known quantized based watermarking schemes Scalar Costa Scheme (SCS), and Trellis Coded Quantization scheme (TCQ) in an independent domain. For our study, the independent domain is obtained by the combination of the cited schemes with Independent Component Analysis (ICA). The Independent Component Analysis is used while inserting and extracting the message. Thus a performance compromise improvement of the original SCS and TCQ schemes in terms of robustness, capacity, and security is shown. Then the obtained schemes performances are compared to the Spread Transform (ST) based scheme well known for its proven good robustness properties. Our results show that, using watermarking with side information in independent domain permits to improve the global SCS and TCQ schemes performances. For example, in the case of SCS, by studying the Bit Error Rate (BER) in function of the watermark to noise ratio (WNR), the robustness has been improved by 20 dB (1 decade) when WNR is equal to 0 dB. Moreover, the capacity study shows for the same WNR=0 dB, the amount of information to be transmitted without error for a given noise level of the proposed SCS combined with ICA scheme (SCS-ICA) is much higher than that of the existing schemes. Finally, the study of the probability density functions (PDF) of the original and marked signals has shown that the Cachin-security level of the TCQ in an independent domain scheme (TCQ-ICA) is the best one compared to the other known schemes.     

Microsatellite instability in gynecological sarcomas and in hMSH2 mutant uterine sarcoma cell lines defective in mismatch repair activity

We have examined a panel of gynecological sarcomas for microsatellite instability. The genomic DNA from 11 of 44 sarcomas contained somatic alterations in the lengths of one or more di-, tri-, tetra-, or pentanucleotide microsatellite sequence markers, and 6 of these cases had alterations in two or more markers. In addition, di-, tri-, and tetranucleotide microsatellites were found to be highly unstable in single cell clones of two cell lines derived from a uterine mixed mesodermal tumor. Since such instability is characteristic of cells defective in postreplication mismatch repair, we examined mismatch repair activity in extracts made from these lines. Both extracts were repair deficient, while an extract of another gynecological sarcoma cell line not exhibiting microsatellite instability was repair proficient. The repair deficiency was complemented by a colon tumor cell extract that was defective in the hMLH1 protein but not by an extract defective in hMSH2 protein. This suggested that the defect in the uterine sarcoma line could be in hMSH2. Subsequent analysis of the gene revealed a 2-bp deletion in exon 14, leading to premature truncation of the hMSH2 protein at codon 796 and no detectable wild-type gene present. These data suggest that the microsatellite instability observed in these cell lines, and possibly in a significant number of gynecological sarcomas, is due to defective postreplication mismatch repair. There was no apparent correlation with microsatellite instability and clinical outcome.     

Random exploration of the Kluyveromyces lactis genome and comparison with that of Saccharomyces cerevisiae

The genome of the yeast Kluyveromyces lactis was explored by sequencing 588 short tags from two random genomic libraries (random sequenced tags, or RSTs), representing altogether 1.3% of the K. lactis genome. After systematic translation of the RSTs in all six possible frames and comparison with the complete set of proteins predicted from the Saccharomyces cerevisiae genomic sequence using an internally standardized threshold, 296 K.lactis genes were identified of which 292 are new. This corresponds to approximately 5% of the estimated genes of this organism and triples the total number of identified genes in this species. Of the novel K.lactis genes, 169 (58%) are homologous to S.cerevisiae genes of known or assigned functions, allowing tentative functional assignment, but 59 others (20%) correspond to S.cerevisiae genes of unknown function and previously without homolog among all completely sequenced genomes. Interestingly, a lower degree of sequence conservation is observed in this latter class. In nearly all instances in which the novel K.lactis genes have homologs in different species, sequence conservation is higher with their S.cerevisiae counterparts than with any of the other organisms examined. Conserved gene order relationships (synteny) between the two yeast species are also observed for half of the cases studied.