26 research outputs found

    Evaluation of a firm model in estimating aggregate supply response

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    The North Central Regional Research Project NC- 54, “Supply Response and Adjustments for Hog and Beef Cattle Production,” was started in 1961. The project statement lists these objectives: (1) To estimate farm resource use and supply response of hogs and beef cattle in representative farm situations. (2) To estimate total production of hogs and beef cattle and patterns of resource use for states in the North Central Region and for the nation. (3) To determine the production situations and the areas in which a specified output of hogs and beef cattle would or could be produced most efficiently under various projected levels of demand and prices and at a given level of technology representing that now known but not yet generally adopted. Linear-programming, time-series analysis, production function analysis and “outlook” research were used in the study. The linear-programming research was divided into two phases. Phase I involved (a) estimating the optimum organization and production for representative farms at various prices for hogs, cattle and feed grains and (b) aggregating these results to give estimates of regional production. The purpose of Phase II was to examine the effects of permitting acquisition and disposal of factors of production assumed fixed in the Phase I model. This was accomplished by including purchase and sale activities for fixed assets at predetermined prices. Insofar as the purchases and sales were not conducted within a framework of regional constraints and because an appropriate weighting scheme was not readily available, no aggregation of the Phase II results was made. Time-series analysis, production function analysis and “outlook” analysis were used to complement the programming analysis

    Plasmid-mediated AmpC

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    _Objectives:_ The objective of this study was to determine the prevalence of pAmpC beta-lactamases in community-acquired Gram negative bacteria in the Netherlands, and to identify possible risk factors for carriage of these strains. Methods: Fecal samples were obtained from community-dwelling volunteers. Participants also returned a questionnaire for analysis of risk factors. Screening for pAmpC was performed with selective enrichment broth and a selective screening agar. Confirmation of AmpC-production was performed with two double disc combination tests: cefotaxime and ceftazidime with either boronic acid or cloxacillin as inhibitor. Multiplex PCR was used as gold standard for detection of pAmpC. 16S rRNA PCR and AFLP were performed as required, plasmids were identified by PCR-based replicon typing. Questionnaire results were analyzed with SPSS, version 20.0. Results: Fecal samples were obtained from 550 volunteers; mean age 51 years (range: 18-91), 61% were females. pAmpC was present in seven E. coli isolates (7/550, 1.3%, 0.6-2.7 95% CI): six CMY-2-like pAmpC and one DHA. ESBL-encoding genes were found in 52/550 (9.5%, 7.3-12.2 95% CI) isolates; these were predominantly blaCTX-M genes. Two isolates had both ESBL and pAmpC. Admission to a hospital in the previous year was the only risk factor we identified. Conclusions: Our data indicate that the prevalence of pAmpC in the community seems still low. However, since pAmpC-producing isolates were not identified as ESBL producers by routine algorithms, there is consistent risk that further increase of their prevalence might go undetected

    Successful high-dosage monotherapy of tigecycline in a multidrug-resistant Klebsiella pneumoniae pneumonia-septicemia model in rats

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    Background: Recent scientific reports on the use of high dose tigecycline monotherapy as a “drug of last resort” warrant further research into the use of this regimen for the treatment of severe multidrug-resistant, Gram-negative bacterial infections. In the current study, the therapeutic efficacy of tigecycline monotherapy was investigated and compared to meropenem monotherapy in a newly developed rat model of fatal lobar pneumonia-septicemia. Methods: A Klebsiella pneumoniae producing extended-spectrum β-lactamase (ESBL) and an isogenic variant producing K. pneumoniae carbapenemase (KPC) were used in the study. Both strains were tested for their in vitro antibiotic susceptibility and used to induce pneumonia-septicemia in rats, which was characterized using disease progression parameters. Therapy with tigecycline or meropenem was initiated at the moment that rats suffered from progressive infection and was administered 12-hourly over 10 days. The pharmacokinetics of meropenem were determined in infected rats. Results: In rats with ESBL pneumonia-septicemia, the minimum dosage of meropenem achieving survival of all rats was 25 mg/kg/day. However, in rats with KPC pneumonia-septicemia, this meropenem dosage was unsuccessful. In contrast, all rats with KPC pneumonia-septicemia were successfully cured by administration of high-dose tigecycline monotherapy of 25 mg/kg/day (i.e., the minimum tigecycline dosage achieving 100% survival of rats with ESBL pneumonia-septicemia in a previous study). Conclusions: The current study supports recent literature recommending high-dose tigecycline as a last resort regimen for the treatment of severe multidrug-resistant bacterial infections. The use of ESBL- and KPC-producing K. pneumoniae strains in the current rat model of pneumonia-septicemia enables further investigation, helping provide supporting data for follow-up clinical trials in patients suffering from severe multidrug-resistant bacterial respiratory infections

    A national cross-sectional survey of dental anxiety in the French adult population

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    <p>Abstract</p> <p>Background</p> <p>Dental anxiety is a public health problem but no epidemiological study has been undertaken in France to evaluate its prevalence. The aim of this study was to estimate the prevalence, severity and associations of dental anxiety in a sample of the French adult population.</p> <p>Methods</p> <p>A convenience sample of 2725 adults (mean age = 47 years, SD16, minimum = 16, maximum = 101 years), representative of the French population with regard to age and urban distribution, completed a French version of the Corah Dental Anxiety scale (DAS) and a questionnaire relating to their dental appointments.</p> <p>Results</p> <p>Moderate dental anxiety (14≥DAS≥13) was revealed for 172 persons (6.2%), while 195 (7.3%) had severe dental anxiety (DAS≥15), giving an overall prevalence of dental anxiety of 13.5%. Prevalence was lower proportionally with age (P < 0.001) and was higher in French overseas territories and in the countryside (P < 0.01). Farmers and low skilled workers were significantly more anxious than executives and shopkeepers (P < 0.001). Anxiety was associated with avoidance of care (p < 0.001) and lack of regular dental appointments (p < 0.001).</p> <p>Conclusion</p> <p>Dental anxiety in France appears to concern a similar proportion of the population as in other industrialised European, Australasian or North American countries. Recommendations for prevention and management of dental anxiety are made with reference to dental education and health care services in France.</p

    Investigations into the killing activity of an antimicrobial peptide active against extensively antibiotic-resistant K. pneumoniae and P. aeruginosa

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    SET-M33 is a multimeric antimicrobial peptide active against Gram-negative bacteria in vitro and in vivo. Insights into its killing mechanism could elucidate correlations with selectivity. SET-M33 showed concentration-dependent bactericidal activity against colistin-susceptible and resistant isolates of P. aeruginosa and K. pneumoniae. Scanning and transmission microscopy studies showed that SET-M33 generated cell blisters, blebs, membrane stacks and deep craters in K. pneumoniae and P. aeruginosa cells. NMR analysis and CD spectra in the presence of sodium dodecyl sulfate micelles showed a transition from an unstructured state to a stable α-helix, driving the peptide to arrange itself on the surface of micelles. SET-M33 kills Gram-negative bacteria after an initial interaction with bacterial LPS. The molecule becomes then embedded in the outer membrane surface, thereby impairing cell function. This activity of SET-M33, in contrast to other similar antimicrobial peptides such as colistin, does not generate resistant mutants after 24h of exposure, non-specific interactions or toxicity against eukaryotic cell membranes, suggesting that SET-M33 is a promising new option for the treatment of Gram-negative antibiotic-resistant infections

    A randomized controlled trial of the efficacy and cost-effectiveness of a brief intensified cognitive behavioral therapy and/or pharmacotherapy for mood and anxiety disorders: Design and methods

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    Background: Anxiety and mood disorders involve a high disease burden and are associated with high economic costs. A stepped-care approach intervention and abbreviated diagnostic method are assumed to increase effectiveness and efficiency of the mental healthcare and are expected to reduce economic costs. Methods: Presented are the rationale, design, and methods of a two-armed randomized controlled trial comparing \u27treatment as usual\u27 (TAU) with a brief intensified cognitive behavioral therapy (CBT) and/or pharmacotherapy. Eligible participants (N =500) of five Dutch outpatient Mental Healthcare Centers are randomly assigned to either TAU or to the experimental condition (brief CBT and/or pharmacotherapy). Data on patients\u27 progress and clinical effectiveness of treatment are assessed at baseline, post-treatment (3. months after baseline), and at 6 and 12. months post-treatment by Routine Outcome Monitoring (ROM). Cost analysis is performed on the obtained data. Discussion: Since few studies have investigated both the clinical and cost effectiveness of a stepped-care approach intervention and a shortened diagnostic ROM method in both anxiety and/or mood disorders within secondary mental health care, the results of this study might contribute to the improvement of (cost)-effective treatment options and diagnostic methods for these disorders

    The Feasibility of Measuring Lung Hyperinflation with a Smart Shirt: An in Vitro Study

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    Home monitoring of patients with chronic obstructive pulmonary disease can increase quality of life and decrease health care costs. Despite the existence of an important relationship between lung hyperinflation (LH) and patient outcomes, LH is often ignored in home monitoring as it difficult to assess at home. A smart shirt containing respiratory inductance plethysmography (RIP, which measures thoracic and abdominal cross-sectional area changes) is a promising tool for home monitoring of LH. This study investigates the feasibility of a smart shirt to monitor LH. We aimed to describe the relationship between temperature and the output, and between the circumference and output of the smart shirt and to correct for temperature dependency. To do so, the smart shirt was applied to a custom-made torso model. Ambient temperature was increased and decreased in 15 tests, while maintaining a constant torso circumference to derive a temperature correction. Additionally, sensor output was monitored with varying circumference. The results revealed a linear relation between temperature and RIP output. Nine of the twelve shirts showed a linear output to changes in circumference. A median temperature drift of -34.7 mL/°C was observed and corrected to a minimum drift of -0.5 mL/°C. In conclusion, RIP is a promising method for measuring LH in home monitoring. Patients will not be falsely diagnosed with LH due to temperature changes. Sensor output can easily be corrected for temperature. Furthermore, the relationship between circumference and output is linear, confirming the ease of implementing the calibration procedure for obtaining lung volumes

    The accuracy of tidal volume measured with a smart shirt during tasks of daily living in healthy subjects: Cross-sectional study

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    Background: The Hexoskin is a smart shirt that can take continuous and objective measurements and could be part of a potentialtelemonitoring system.Objective: The aim of this study was to determine the accuracy of the calibrated Hexoskin in measuring tidal volumes (TVs)in comparison to spirometry during various tasks.Methods: In a cross-sectional study, the TV of 15 healthy subjects was measured while performing seven tasks using spirometryand the Hexoskin. These tasks were performed during two sessions; between sessions, all equipment was removed. A one-Timespirometer-based calibration per task was determined in session 1 and applied to the corresponding task in both sessions.Bland-Altman analysis was used to determine the agreement between TV that was measured with the Hexoskin and that measuredwith spirometry. A priori, we determined that the bias had to be less than ±5%, with limits of agreement (LOA) of less than ±15%.Lung volumes were measured and had to have LOA of less than ±0.150 L.Results: In the first session, all tasks had a median bias within the criteria (±0.6%). In the second session, biases were ±8.9%;only two tasks met the criteria. In both sessions, LOA were within the criteria in six out of seven tasks (±14.7%). LOA of lungvolumes were greater than 0.150 L.Conclusions: The Hexoskin was able to correctly measure TV in healthy subjects during various tasks. However, afterreapplication of the equipment, calibration factors were not able to be reused to obtain results within the determined boundaries.Trial Registration: Netherlands Trial Register NL6934; https://www.trialregister.nl/trial/6934

    Reproducibility of hypercapnic ventilatory response measurements with steady-state and rebreathing methods

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    In this study, the hypercapnic ventilatory response (HCVR) was measured, defined as the ventilation response to carbon dioxide tension (PCO2). We investigated which method, rebreathing or steady-state, is most suitable for measurement of the HCVR in healthy subjects, primarily based on reproducibility. Secondary outcome parameters were subject experience and duration. 20 healthy adults performed a rebreathing and steady-state HCVR measurement on two separate days. Subject experience was assessed using numeric rating scales (NRS). The intraclass correlation coefficient (ICCs) of the sensitivity to carbon dioxide above the ventilatory recruitment threshold and the projected apnoea threshold were calculated to determine the reproducibility of both methods. The ICCs of sensitivity were 0.89 (rebreathing) and 0.56 (steady-state). The ICCs of the projected apnoea threshold were 0.84 (rebreathing) and 0.25 (steady-state). The steady-state measurement was preferred by 16 out of 20 subjects; the differences in NRS scores were small. The hypercapnic ventilatory response measured using the rebreathing setup provided reproducible results, while the steady-state method did not. This may be explained by high variability in end-tidal PCO2. Differences in subject experience between the methods are small

    Reproducibility of hypercapnic ventilatory response measurements with steady-state and rebreathing methods

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    In this study, the hypercapnic ventilatory response (HCVR) was measured, defined as the ventilation response to carbon dioxide tension (PCO2). We investigated which method, rebreathing or steady-state, is most suitable for measurement of the HCVR in healthy subjects, primarily based on reproducibility. Secondary outcome parameters were subject experience and duration. 20 healthy adults performed a rebreathing and steady-state HCVR measurement on two separate days. Subject experience was assessed using numeric rating scales (NRS). The intraclass correlation coefficient (ICCs) of the sensitivity to carbon dioxide above the ventilatory recruitment threshold and the projected apnoea threshold were calculated to determine the reproducibility of both methods. The ICCs of sensitivity were 0.89 (rebreathing) and 0.56 (steady-state). The ICCs of the projected apnoea threshold were 0.84 (rebreathing) and 0.25 (steady-state). The steady-state measurement was preferred by 16 out of 20 subjects; the differences in NRS scores were small. The hypercapnic ventilatory response measured using the rebreathing setup provided reproducible results, while the steady-state method did not. This may be explained by high variability in end-tidal PCO2. Differences in subject experience between the methods are small
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