Search

This paper provides a deeper analysis of the relationships between interfunctional coordination (IFC) and business performance (BP). IFC is studied in many fields such as marketing, management, logistics, informatics or human resources. The novelty lies in offering an original perspective on IFC and its impact on individual items of BP. The statistical analysis of the relationship between IFC and BP is based on a survey of small and medium-sized manufacturers. Sufficient models were identified by a stepwise backward procedure based on Akaike information criterion (AIC). The results show that it is possible to find a sufficient model for each item of BP. Sets of IFC items with exclusively positive or negative influence on at least two BP items were identified. These items of IFC are aimed on cooperative arrangement, expertise, leadership style, coordination activities and control. This research brings theoretical contributions and can be useful for managers.

The Weibull distribution is frequently applied in various fields, ranging from economy, business, biology, to engineering. This paper aims at estimating the parameters of two-parameter Weibull distribution are determined. For this purpose, the method of quantiles (three different choices of quantiles) and Weibull probability plot method is utilized. The asymptotic covariance matrix of the parameter estimates is derived for both methods. For optimal random choices of quantiles, the variance, covariance and generalized variance is computed. The main contribution of this study is the introduction of the best choice of percentiles for the method of quantiles and the joint asymptotic efficiency comparison of applied methods.

The paper deals with testing of the hypothesis of equality of expectations among p samples from Poisson or negative binomial distribution. a comparison of two main approaches is carried out. The first approach is based on transforming the samples from either Poisson or negative binomial distribution in order to achieve normality or variance stability, and then testing the hypothesis of equality of expectations via the F‑test. In the second approach, test statistics coming from the theory of maximum likelihood appearing in generalised linear models framework, specially designed for testing the hypothesis among samples from the respective distributions (Poisson or negative binomial), are used. The comparison is done graphically, by plotting the simulated power functions of the test of the hypothesis of equality of expectations, when first or second approach was used. Additionally, the relationship between the power functions obtained via the respective approaches and sample sizes is studied by evaluating the respective power functions as functions of a sample size numerically.

Brno and Graz, the second largest cities of their countries, observe in each winter season PM10 concentrations of daily means which regularly exceed the limit value of 50 ?g/m3. This is mainly caused by unfavorable dissemination conditions of the ambient air. Hence, partial regulation measures have to be taken in Brno and Graz where specific decisions for certain regulations may be based on the average PM10 concentration of the next day provided that reliable forecasts of these values are available. For several sites in the two cities we establish forecasts of daily PM10 concentrations based on multiple linear regression and generalized linear models utilizing both measured covariates of the present day and meteorological forecasts of the next day. The comparisons, based on different quality measures demonstrate the usefulness of both model approaches as they yield results of similar quality. Our prediction models may support future decisions concerning possible traffic restrictions or other regulations.

The purpose is to acquaint readers with the contribution of imaging methods (IMs) of the orbit, specifically computed tomography (CT) and magnetic resonance imaging (MRI), in the diagnosis of thyroid-associated orbitopathy (TAO). Methods: IMs of the orbit are an indispensable accessory in the clinical and laboratory examination of TAO patients. The most frequently used and probably most accessible method is an ultrasound examination of the orbit (US), which, however, has a number of limitations. Other methods are CT and MRI. Based on the published knowledge implemented in our practice and several years of experience with the diagnosis and treatment of TAO patients, we would like to point out the benefits of CT and MRI in the given indications: visualisation of the extraocular muscles, assessment of disease activity, diagnosis of dysthyroid optic neuropathy and differential diagnosis of other pathologies in the orbit. Our recommendation for an ideal MRI protocol for disease activity evaluation is also included.  Conclusion: IMs play an irreplaceable role not only in the early diagnosis of TAO, but also in the monitoring of the disease and the response to the applied treatment. When choosing a suitable IM for this diagnosis, a number of factors must always be taken into account; not only availability, cost and burden for the patient, but especially the sensitivity and specificity of the given method for the diagnosis of TAO.

Purpose: The aim of this pilot study was to assess oxygen saturation in retinal blood vessels in patients with monoclonal gammopathies (MGs)., Methods: Thirty-one patients with MGs (11 women and 20 men, mean age 65.9 ± 8.9 years) were enrolled during 2016-2020. The patients were diagnosed at the Haemato-Oncology Department and subsequently examined at the Ophthalmology Department before initiating systemic therapy. All patients were subjected to automatic retinal oximetry (Oxymap ehf.) and had their fundus photographed (Topcon TRC-50DX retinal camera). We assessed the association between retinal oxygen saturation (SatO 2 ) - arterial SatO 2 , venous SatO 2 and arterio-venous (AV) difference-and MGs parameters: serum monoclonal immunoglobulin (M-protein) level and serum immunoglobulin-free light chains (FLC kappa and lambda), total protein, serum viscosity, haemoglobin, albumin, lactate dehydrogenase, C-reactive protein, creatinine and serum calcium level. Hyperviscosity-related retinopathy was also evaluated., Results: Statistical analysis showed a significant positive correlation (r = 0.462; p = 0.009) between the AV difference and the haemoglobin level. A significant, medium strong negative correlation was found between the AV difference and the serum levels of the monoclonal light lambda chains (r = -0.450; p = 0.011). Contrary to expectations, no statistically significant correlation was found between retinal oxygen saturation and the total protein or viscosity., Conclusion: This study found correlation between retinal oxygen saturation and certain parameters in the blood of patients with MGs. Increasing levels of monoclonal immunoglobulin seem to reduce oxygen absorption in retinal arterioles, resulting in a lower AV difference, particularly in patients with a high free light chain level., (© 2022 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Management of patients with thyroid-associated orbitopathy (also called Graves' disease) is dependent on the assessment of the disease activity. Evaluation of disease activity is based on ophthalmological examination. Magnetic resonance imaging (MRI) is an auxiliary method that may help quantify the activity and is also helpful in obtaining anatomical information concerning muscle thickness, exophthalmos, or optic neuropathy. We present a review of MRI techniques of the orbits with emphasis on the evaluation of disease activity. The most convincing seems to be the group of T2-weighted techniques such as conventional T2 weighting, T2 relaxometry, and T2 mapping. Dynamic contrast-enhanced MRI is another promising method., (Copyright © 2022 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Purpose: Purpose of this prospective uncontrolled single-centre pilot study was to find an association of retinal oxygen saturation (SatO 2 ) with acid-base balance (ABB), carboxyhaemoglobin concentration, current plasma glucose concentration (PG), mean PG and PG variability over the last 72 hr, haemoglobin A1c (HbA1c), and other conditions., Methods: Forty-one adults (17 men) with type 1 (N = 14) or type 2 (N = 27) diabetes mellitus, age 48.6 ± 13.5 years, diabetes duration 9 (0.1-36) years, BMI 29.4 ± 6.3 kg/m 2 , and HbA1c 52 ± 12.7 mmol/mol completed the study. The 4-day study comprised two visits (Day l, Day 4) including 72 hr of continuous glucose monitoring (CGM) by iPro ® 2 Professional CGM (Medtronic, MiniMed, Inc., Northridge, CA, USA). Retinal oximeter Oxymap T1 (Oxymap ehf., Reykjavik, Iceland) was used to assess SatO 2 ., Results: Wilcoxon signed-rank test showed no SatO 2 difference between eyes and visits. Spearman's correlation analysis revealed a significant correlation between arterial SatO 2 and PG variability in type 2 diabetes mellitus, a positive correlation of venous SatO 2 with HbA1c and with finger pulse oximetry. However, no correlation of SatO 2 with ABB, carboxyhaemoglobin, current PG, mean PG over the 72 hr, age, diabetes duration, BMI, lipoproteinaemia, body temperature, systolic and diastolic blood pressure, heart rate, central retinal thickness and retinal nerve fibre layer thickness was found., Conclusion: This study confirmed the association of venous SatO 2 with long-term but not with short-term diabetes control, ABB and other conditions. The increased SatO 2 and questionable impact of PG variability on retinal SatO 2 is a research challenge., (© 2021 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose: To inform about possible use of the automatic retinal oximetry for the retinal oxygen saturation measurement in the eye and systemic diseases., Methods: We performed a literature review dealing with issues of retinal oxygen saturation monitoring by dual non-invasive retinal oximetry Oxymap T1 (Oxymap ehf. Reykjavík, Iceland)., Results: We have found two main strains writing our paper on retinal oxygen saturation eye diseases. The first section concerns diseases created by having hypoxia as its main pathological factor  - for example diabetes mellitus and retinal vein occlusion. The second group deals with atrophy as the main pathological mechanism which is typical for decreasing retinal oxygen consumption - for example glaucoma or retinitis pigmentosa (the second one named is not included in our work). Oximetry in systemic diseases creates a relatively new chapter of this branch with a very big potential of interdisciplinary cooperation for the future. It is possible the cooperation will not only include diabetologists but also neurologists (for example, in diseases like sclerosis multiplex or Devics, Alzheimers and Parkinsons disease) and haematologists (retinal oxygen saturation changes in patients with different rheological attributes of blood)., Conclusion: Retinal oxygen saturation measuring by automatic retinal oximetry is a relatively new method with scientifically confirmed high reproducibility of results. Currently it is the only experimental method with vast potentials not only in the realm of the possibility of observing eye diseases (diabetic retinopathy, retinal vein occlusion or glaucoma) but also in developing interdisciplinary cooperation with diabetologists, neurologists and haematologists.

Purpose: Optic neuritis (ON) is an inflammatory demyelinating disorder of the optic nerve, which can be the first manifestation of multiple sclerosis (MS). The main goal was to assess changes in the retinal nerve fibre layer (RNFL) and in retinal oxygen saturation [arterial (AS), venous (VS) and arterio-venous (A-V) difference] in the affected and unaffected eye., Methods: Fifty patients with ON due to MS within 3 months of onset of symptoms were enrolled (17 males, mean age 35.3). All patients were examined at baseline (V1) and after 6 months (V2) using optical coherence tomography (OCT) to get RNFL values; automatic retinal oximetry to obtain saturation values; and ultrasound to exclude arterial stenosis, and orbital colour Doppler imaging was performed in the ophthalmic artery., Results: At V1, AS was significantly increased in affected eye compared to unaffected eye (99.5% versus 98.0%, p = 0.03). Significant decrease in A-V difference from baseline was detected in both eyes for ON eye: 32.0% versus 29.0%, p = 0.004; for fellow eye: 31.4% versus 30.0%, p = 0.04. We did not observe any changes in retinal vessel diameter. There were no changes observed in blood flow in ophthalmic artery. At V1, there were no significant differences in RNFL, and significant loss of RNFL was confirmed in the affected eye at V2 (95 μm versus 86 μm, p = 0.0002) and in comparison with the fellow eye (86 μm versus 94 μm, p = 0.0002). There were no correlations between RNFL and saturation values at V1, although at V2, there was a negative correlation between the RNFL and AS (Spearman's rho = -0.480, p = 0.003) and between the RNFL and VS (rho = -0.620, p = 0.00007)., Conclusion: Retinal oximetry is altered in both eyes in MS patients with unilateral ON. During the course of the disease, the retinal oxygen consumption decreases to a different degree in each eye and this change is not completely followed by changes in the RNFL thickness, suggesting either sub-clinical ON or systemic effects in the clinically unaffected eye. Since this is the first and initial longitudinal evaluation of the saturation changes in MS patients, the clinical value of these findings needs to be deeper evaluated in the future studies., (© 2020 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)