Search

A mobile agent navigating along edges of a simple connected unweighted graph, either finite or countably infinite, has to find an inert target (treasure) hidden in one of the nodes. This task is known as treasure hunt. The agent has no a priori knowledge of the graph, of the location of the treasure, or of the initial distance to it. The cost of a treasure hunt algorithm is the worst-case number of edge traversals performed by the agent until finding the treasure. Awerbuch et al. [3] considered graph exploration and treasure hunt for finite graphs in a restricted model where the agent has a fuel tank that can be replenished only at the starting node s. The size of the tank is B = 2(1 + a)r, for some positive real constant a, where r, called the radius of the graph, is the maximum distance from s to any other node. The tank of size B allows the agent to make at most -B° edge traversals between two consecutive visits at node s. Let e (d) be the number of edges whose at least one endpoint is at distance less than d from s. Awerbuch et al. [3] conjectured that it is impossible to find a treasure hidden in a node at distance at most d at cost nearly linear in e (d). We first design a deterministic treasure hunt algorithm working in the model without any restrictions on the moves of the agent at cost O(e (d) logd) and then show how to modify this algorithm to work in the model from Awerbuch et al. [3] with the same complexity. Thus, we refute the preceding 20-year-old conjecture. We observe that no treasure hunt algorithm can beat cost T(e (d)) for all graphs, and thus our algorithms are also almost optimal. [ABSTRACT FROM AUTHOR]

Treasure hunt is finding a hidden inert target by a mobile agent. We consider deterministic algorithms for treasure hunt in trees. Our goal is to establish the impact of different kinds of initial knowledge given to the agent on the cost of treasure hunt, defined as the total number of edge traversals until the agent reaches the treasure. The agent can be initially given either a complete map of the tree rooted at its starting node, with all port numbers marked, or a blind map of the tree rooted at its starting node but without port numbers. It may also be given, or not, the distance from the root to the treasure. This yields four different knowledge types that are partially ordered by their precision. The penalty of a less precise knowledge type 풯2 over a more precise knowledge type 풯1 measures intuitively the worst‐case ratio of the cost of an algorithm supplied with knowledge of type 풯2 over the cost of an algorithm supplied with knowledge of type 풯1. Our main results establish penalties for comparable knowledge types in this partial order. For knowledge types with known distance, the penalty for having a blind map over a complete map turns out to be very large. By contrast, for unknown distance, the penalty of having a blind map over having a complete map is small. When a map is provided (either complete or blind), the penalty of not knowing the distance over knowing it is medium. [ABSTRACT FROM AUTHOR]

The MI, Chromocult® coliform, and Compass CC chromogenic culture-based methods used to assess water quality by the detection of Escherichia coli and total coliforms were compared in terms of their specificity and sensitivity, using 16S rRNA sequencing for colony identification. A sewage water sample was divided in 2-ìL subsamples for testing by all three culture-based methods. All growing colonies were harvested and subjected to 16S rRNA sequencing. Test results showed that all E. coli colonies were correctly identified by all three methods, for a specificity and a sensitivity of 100%. However, for the total coliform detection, the MI agar, Chromocult® coliform agar, and Compass CC agar were specific for only 69.2% (9/13), 47.2% (25/53), and 40.5% (17/42), whereas sensitive for 97.8% (45/46), 97.5% (39/40), and 85.7% (24/28), respectively. Thus, given the low level of specificity of these methods for the detection of total coliforms, confirming the identity of total coliform colonies could help to take public health decisions, in particular for cities connected to a public drinking water distribution system since the growth of few putative total coliform colonies on chromogenic agar is problematic and can lead to unnecessary and costly boiling notices from public health authorities. [ABSTRACT FROM AUTHOR]

The mEI, Chromocult® enterococci, and m-Enterococcus culture-based methods used to assess water quality by the detection of Enterococcus spp. were first compared in terms of sensitivity using (1) 41 different type strains of Enterococcus spp. and (2) environmental colonies identified by 16S rRNA sequencing. Then, two specific-rtPCR assays targeting Enterococcus spp. and Enterococcus faecalis/faecium were tested for their ability to confirm the identity of putative enterococcal colonies. The mEI, Chromocult® enterococci, and m-Enterococcus methods detected β-glucosidase activity for 28 (68.3%), 32 (78.0%), and 12 (29.3%) of the 41 reference enterococcal strains tested, respectively. Analysis with environmental colonies showed that mEI and Chromocult® enterococci media had false positive rates of 4.3% and 5.0%, respectively. Finally, the two rtPCR assays showed a specificity of 100%. Only two (2/19) colonies of E. faecium isolated from mEI agar were not detected by the Enterococcus faecium rtPCR assay, for a sensitivity of 89.5%. Our results showed that Chromocult® enterococci medium recovered more E. faecalis/faecium cells than the two other methods. Thus, the use of Chromocult® enterococci combined with the Enterococcus faecalis/ faecium rtPCR assay showed the best combination to decrease the high false-positive rate obtained when the entire Enterococcus genus is targeted. [ABSTRACT FROM AUTHOR]

The MI agar, Colilert®, Chromocult coliform® agar, and DC with BCIG agar chromogenic culture-based methods used to assess microbiological quality of drinking water were compared in terms of their ubiquity, sensitivity, ease of use, growth of atypical colonies and affordability. For ubiquity, 129 total coliform (representing 76 species) and 19 Escherichia coli strains were tested. Then, 635 1-L well water samples were divided into 100 mL subsamples for testing by all four methods. Test results showed that 70.5, 52.7,36.4, and 23.3% of the non-E coli total coliform strains and 94.7,94.7, 89.5, and 89.5% of the 19 E. coli strains yielded a positive signal with the four methods, respectively. They also yielded a total coliform positive signal for 66.5, 51.7, 64.9, and 55.0% and an E. coli positive signal for 16.1,14.8,17.3, and 13.4% of the 635 well water samples tested, respectively. Results showed that Colilert® is the most expensive method tested in terms of reactants, yet it is the easiest to use. Large numbers of atypical colonies were also often observed on Chromocult coliform® and DC with BCIG, thereby challenging the target microorganism count. Thus, the MI agar method seems to be the best option for the assessment of drinking water quality. [ABSTRACT FROM AUTHOR]

MI agar and Colilert®, as well as mFC agar combined with an Escherichia coli-specific molecular assay (mFC + E. coli rtPCR), were compared in terms of their sensitivity, ease of use, time to result and affordability. The three methods yielded a positive E. coli signal for 11.5, 10.8, and 11.5% of the 968 well water samples tested, respectively. One hundred and thirty-six (136) samples gave blue colonies on mFC agar and required confirmation. E. coli-specific rtPCR showed false-positive results in 23.5% (32/136) of cases. In terms of ease of use, Colilert was the simplest method to use while the MI method provided ease of use comparable to all membrane filtration methods. However, the mFC + E. coli rtPCR assay required highly trained employees for confirmation purposes. In terms of affordability, and considering contamination rate of well water samples tested, the Colilert method and the mFC + E. coli rtPCR assay were at least five times more costly than the MI agar method. Overall, compared with the other two methods tested, the MI agar method offers the most advantages to assess drinking water quality. [ABSTRACT FROM AUTHOR]

Objectives. Several studies suggest that health professionals show negative attitudes towards people with Borderline Personality Disorder (BPD). Many publications have focused on the attitudes of nurses or other type of clinicians like social workers or psychologists. Few researches concern the attitudes of general physicians towards BPD even if they are the main professionals involved in the evaluation and treatment of these patients. Additionally, patients with BPD frequently consult general physicians and, because of the difficulties interacting with these patients, they do not always receive the treatments required by their condition. This research aims to assess the attitudes of general physicians and family medicine residents regarding patients presenting with this disorder. Method. Forty family medicine residents and thirty-five general physicians were compared to thirty-nine mental health professionals using the Attitudes toward people with BPD Scale (ABPDS; Bouchard, 2001). This measure has two subscales labeled Comfort when interacting with someone who has BPD and Positives perceptions about BPD. The internal consistency of the scale as well as the two distinct factors are satisfactory. The participants also complete a socio-demographic questionnaire. Means, t tests, ANOVAs and factorial ANOVAs are completed in order to compare the three groups on the ABPDS and explore the influence of variables such as sex, age, years of experience, and professional setting (urban or rural) on the results. Results. The results show that general physicians have similar attitudes than mental health professionals towards people presenting with BPD and that family medicine residents present less positive attitude than the other two groups. In addition, clinicians with less experience tend to have less positive attitudes towards people with BPD and clinicians from urban settings seem to have more positive attitude. It was difficult to determinate which variables influence the results because the years of experience, the professional settings and the title of the participants are extremely related. The factorial ANOVAs show no interaction effect between these three variables. Conclusion. Several studies show that health professionals present negative attitudes toward patients with BPD. This study reveals that general physicians and family medicine residents show respectively similar attitudes or less positive attitudes than other mental health professionals. These results underline the importance of providing specific training about BPD to family medicine residents. Because general physicians guide the evaluations and interventions concerning these patients and mental health professionals interact regularly with BPD, it will be helpful if all the clinicians receive more specific training regarding this disorder. [ABSTRACT FROM AUTHOR]

Copyright of Sante Mentale au Quebec is the property of Revue Sante Mentale au Quebec and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Borderline personality disorder (BPD) is a severe mental health problem predisposing to dysfunctional interaction behaviors and negative couple outcomes. This study aimed to assess, through direct observation, the quality of relationships of couples in which women were diagnosed with BPD. The sample consisted of 28 couples in which the woman had BPD, and 82 community couples. Couples’ interactions were coded using three scales—withdrawal/ avoidance, dominance, and criticism/attack/conflict—from the Global Couple Interaction Coding System. Couples in which the women had BPD evidenced significantly more negative behaviors, particularly dominance behaviors, than community couples. Moreover, in BPD couples, women adopted Criticism/Attack/Conflict behaviors more frequently than men. [ABSTRACT FROM AUTHOR]

Copyright of Sante Mentale au Quebec is the property of Revue Sante Mentale au Quebec and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Sante Mentale au Quebec is the property of Revue Sante Mentale au Quebec and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main goal of the present study was to examine and compare the psychosocial functioning of 35 couples including a woman diagnosed with borderline personality disorder (BPD) to that of a nonclinical control sample of 35 couples. The BPD status of women from the clinical group and the prevalence of personality disorder in their partner were ascertained through the SCID-II. Participants completed self-report measures of couple functioning. A majority of couples in which the woman suffered from BPD (68.7%) evidenced frequent episodes of breakups and reconciliations and, over an 18-month period, nearly 30% of these couples dissolved their relationship. Nearly half of the men involved in a romantic relationship with a woman suffering from BPD met criteria for one personality disorder or more. As compared with nonclinical couples, clinical couples showed lower marital satisfaction, higher attachment insecurity, more demand/withdraw communication problems, and higher levels of violence. [ABSTRACT FROM AUTHOR]

Women with Borderline Personality Disorder (BPD) are prone to have sexual relationship difficulties and dysfunctional attitudes toward sexuality. A sample of 34 heterosexual couples composed of women meeting BPD criteria was compared to a sample of dating or married women from the general population. A short form of the Sexual Activities and Attitudes Questionnaire (SAAQ) was used to measure six types of sexual attitudes. Women diagnosed with BPD did not differ from controls on the frequency of three types of sexual activities in the last year but their subjective sexual experiences differed: they showed stronger negative attitudes, felt sexually pressured by their partners, and expressed ambivalence toward sexuality. Regression analyses suggest that anxious attachment mediates the association between BPD and feeling pressured to engage in sex. [ABSTRACT FROM AUTHOR]

Forty-five adults with primary insomnia received cognitive-behavioral therapy (CBT) implemented in a group therapy format, in individual face-to-face therapy or through brief individual telephone consultations. The results indicate that CBT was effective in improving sleep parameters with all 3 methods of treatment implementation, and there was no significant difference across methods of implementation. All 3 treatment modalities produced improvements in sleep that were maintained for 6 months after treatment completion. These results suggest that group therapy and telephone consultations represent cost-effective alternatives to individual therapy for the management of insomnia. [ABSTRACT FROM AUTHOR]

This study describes a self-efficacy (SE) scale and examines its usefulness in predicting adherence to cognitive-behavioral therapy (CBT) of insomnia. The SE scale, which included three subscales (global, task-related, and self-regulation), was administered to 39 patients receiving CBT for primary insomnia. Participants' daily sleep diaries were used to estimate their adherence to treatment. The results showed that the SE scale has adequate psychometric properties. Treatment adherence increased from Week 2 to Week 7 and decreased during the week following the last therapy session. In general, the global self-efficacy measure was more strongly associated with adherence during the first week of treatment, whereas the task-related efficacy was more strongly associated with adherence behaviors from Weeks 4 to 8. These findings suggest that self-efficacy perceptions are useful in predicting adherence to CBT of insomnia. [ABSTRACT FROM AUTHOR]

This work demonstrates the ability of a bacterial concentration and recovery procedure combined with three different PCR assays targeting the lacZ, wecG, and 16S rRNA genes, respectively, to detect the presence of total coliforms in 100-ml samples of potable water (presence/absence test). PCR assays were first compared to the culture-based Colilert and MI agar methods to determine their ability to detect 147 coliform strains representing 76 species of Enterobacteriaceae encountered in fecal and environmental settings. Results showed that 86 (58.5%) and 109 (74.1 %) strains yielded a positive signal with Colilert and MI agar methods, respectively, whereas the lacZ, wecG, and 16S rRNA PCR assays detected 133 (90.5%), 111 (75.5%), and 146 (99.3%) of the 147 total coliform strains tested. These assays were then assessed by testing 122 well water samples collected in the Quebec City region of Canada. Results showed that 97 (79.5%) of the samples tested by culture-based methods and 95 (77.9%), 82 (67.2%), and 98 (80.3%) of samples tested using PCR-based methods contained total coliforms, respectively. Consequently, despite the high genetic variability of the total coliform group, this study demonstrated that it is possible to use molecular assays to detect total coliforms in potable water; the 16S rRNA molecular assay was shown to be as efficient as recommended culturebased methods. This assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality. [ABSTRACT FROM AUTHOR]

Abstract: MI agar (MI), Chromocult® Coliform agar ES (Chromocult), and DC with BCIG agar (DC) are chromogenic membrane filtration culture-based methods used to assess microbiological water quality. In this study, their ability to detect Escherichia coli colonies on confluent growth plates was determined by testing water samples containing increasing concentrations of a non-E. coli growing bacterium, Citrobacter youngae. Then, their ability to inhibit the growth of non-coliform bacteria was determined by simultaneously testing 603 well water samples. Results were compared with those obtained with mFC and Colilert® methods. Results showed that the E. coli count was difficult to determine on mFC, Chromocult and DC when non-E. coli colonies reached levels of 104 colony forming units (CFU)/100mL. However, the E. coli count did not interfere with Colilert until non-E. coli colonies reached concentrations of 107 CFU/100mL. No inhibition was observed with MI as E. coli colonies could be easily detected in the presence of at least 107 CFU/100mL of C. youngae. Using well water samples, confluent growth plates were observed for 144, 177, and 185 of the 603 well water samples tested with the MI, Chromocult and DC methods, respectively. Among these confluent growth plates, E. coli colonies were not detected for 10, 20, and 31 water samples. However, they were detected by the mFC and/or Colilert methods. Thus, among the three methods tested, the MI method presented the lowest grow rate of atypic colonies and was the only one that presents no interference in the E. coli count. [Copyright &y& Elsevier]