172 research outputs found
CVABS: Moving Object Segmentation with Common Vector Approach for Videos
Background modelling is a fundamental step for several real-time computer
vision applications that requires security systems and monitoring. An accurate
background model helps detecting activity of moving objects in the video. In
this work, we have developed a new subspace based background modelling
algorithm using the concept of Common Vector Approach with Gram-Schmidt
orthogonalization. Once the background model that involves the common
characteristic of different views corresponding to the same scene is acquired,
a smart foreground detection and background updating procedure is applied based
on dynamic control parameters. A variety of experiments is conducted on
different problem types related to dynamic backgrounds. Several types of
metrics are utilized as objective measures and the obtained visual results are
judged subjectively. It was observed that the proposed method stands
successfully for all problem types reported on CDNet2014 dataset by updating
the background frames with a self-learning feedback mechanism.Comment: 12 Pages, 4 Figures, 1 Tabl
An applied study on the customer retention dynamics of organized ready-to-wear textiles retailers in real and virtual markets in Turkey
Purpose - This descriptive field study aims to reveal customer retention strategy formulation insights among top level marketing professionals of the organized ready-to-wear textiles retailers, who are members of United Brands Association (BMD) both active in off-line and online channels, in the Turkish market. Methodology - Regarding the literature review conducted a research model with seven variables was proposed, and depending on the proposed research model, six hypotheses were formulated. The research is conducted by a questionnaire which has been applied on-line, by e-mail, post; which is designed specifically to test the proposed relationships, namely the hypotheses constructed. Factor analysis has been conducted to reveal the dimensionality of the variables in the research model. In this regard, principle component analysis using Varimax rotation was performed and the reliabilities of the scales have been assessed by alpha coefficient. Depending on the results of the factor analysis, correlation and regression analyses have been used to test the hypotheses of the study. Findings - Results indicate that perceived product quality, service support and complaint handling, customer experience and suggestions provided and perceived price fairness have significant and positive effects on customer satisfaction. Furthermore, customer satisfaction, trust towards service provided, trust towards company and brand, corporate reputation and corporate social responsibility have significant and positive effects on customer retention. Conclusion - The outcomes and findings of the study were found to support the objectives of the study and the results of the statistical analysis were found to accept hypotheses of the study. Perceived product quality, perceived service quality, perceived price fairness, trust and corporate image are some vital challenges for customer retention.Publisher's Versio
Chiari I malformation presenting with ganglion cell complex thinning on routine examination
Chiari I malformation (CMI) is a rare congenital disorder characterized by the caudal displacement of cerebellar tonsils through the foramen magnum into the cervical canal(1). Ophthalmological signs include retro-orbital pain, diplopia, photophobia, impaired visual acuity, nystagmus, strabismus, and papilledema(2-4). The diagnosis is mostly based on magnetic resonance imaging (MRI) findings © This content is licensed under a Creative Commons Attributions 4.0 International License
Electronic Device Screen Time and Meibomian Gland Morphology in Children
Purpose: To investigate changes in meibomian gland morphology and impact of electronic device usage time on meibomian glands in pediatric age group.
Methods: In this prospective study, 149 eyes of 149 children were enrolled. The participants also completed the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire and provided information regarding weekly hours spent in front of a digital screen. Meibography was performed in all subjects. Grading of images was evaluated using a previously validated 5-point meiboscale (0–4) for meibomian gland atrophy and a 3-point scale for meibomian gland tortuosity (0–2).
Results: Of the 149 enrolled children, 83 (55.7%) were female and 66 (44.3%) male. The mean age was 13.0 ± 3.0 (range: 5–18) years. The mean loss of meibomian gland area was 20.80 ± 9.32%. The mean meiboscore was 1.20 ± 0.58 for gland atrophy and the mean tortuosity score was 0.99 ± 0.62. The mean screen time was 29.32 ± 16.18 hr/week. There was a weak and significantly positive correlation between loss of meibomian gland area and screen time (r = 0.210, p = 0.010). There was a weak and significantly positive correlation between meiboscore for gland atrophy and screen time (r = 0.188, p = 0.022). We found a weak but significantly positive correlation between meibomian gland tortuosity and screen time (r = 0.142, p = 0.033).
Conclusion: Meibomian gland morphology may show changes in pediatric age group and excessive screen time may be a factor triggering these changes in gland morphology
Choroidal vascularity index after a single dose of intravitreal dexamethasone implant in patients with refractory diabetic macular oedema
Purpose: To evaluate choroidal vascularity index (CVI) after a single dose of intravitreal dexamethasone implant in refractory diabetic macular oedema (DME). Methods: Total choroidal area, luminal area, and CVI were measured at baseline, 1st month, and at 3rd month after dexamethasone implant using binarization of enhanced depth imaging optical coherence tomography (EDI-OCT) images. Results: A total of 25 eyes of 25 patients (mean age: 61.4 ± 8.3 years; 12 males, 13 females), were enroled in the study. All eyes had been previously treated with intravitreal aflibercept injections (mean number of injections 4.6 ± 2.5). Mean CVI was 70.3 ± 8.1 prior to intravitreal dexamethasone treatment. It was decreased to 66.1 ± 9.3 at 1 month and 63.5 ± 10.1 at 3 months after treatment. The mean CVI was significantly decreased at 3 months compared with pre-treatment measures (p = 0.033). Conclusion: CVI was found to be decreased in patients who responded to intravitreal dexamethasone implant. © 2022 Elsevier B.V
The effects of pre-harvest napthalene acetic acid and aminoethoxyvinylglycine treatments on storage performance of ‘ Ak Sakı’ apple cultivar grown in Erzincan conditions
This study was carried out to determine the effects of pre-harvest aminoethoxyvinylglycine (AVG, 150, 225 ve 300 mg/L) and naphthaleneacetic acid (NAA, 20 mg/L) treatments in different doses on storage performance of ‘Ak Sakı’ apple cultivar (Malus domestica Borkh.) in 2012. The changes on some fruit quality parameters were measured at 2±1 oC temperature and with 90±5 % relative humidity at 45 days interval during storage. The lowest weight loss was obtained from 300 mg/L AVG treated fruits during the storage. In the all analysis date, the highest L* value was obtained from 300 mg/L AVG treated fruits, and the lowest hue angle value was reported from the fruits of control treatment. The flesh firmness was determined that the best kept in the 225 and 300 mg/L AVG treated fruits during the storage. The flesh firmness significantly reduced with NAA treatment at the end of storage. The highest soluble solids concentration (SSC) was obtain from control fruit during the storage, whereas the lowest SSC was observed in fruit treated with 300 mg/L AVG. In the all analysis date, the highest titratable acidity was obtained in fruits treated with 225 and 300 mg/L AVG. The starch degradation was delayed with AVG treatments
Structural alterations of the choroid evaluated using enhanced depth imaging optical coherence tomography in patients with coronavirus disease
Purpose: To assess choroidal changes using enhanced depth imaging optical coherence tomography in coronavirus disease (COVID-19). Methods: Thirty-two patients with moderate COVID-19 and 34 healthy subjects were included in the study. Choroidal thickness was measured at 3 points as follows: at the subfovea, 1500 mm nasal to the fovea, and 1500 mm temporal to the fovea. The total choroidal area, luminal area, stromal area, and choroidal vascular index were measured with Image-J. All the measurements were performed during the disease and at 4 months after remission. Results: In the patient group, the subfoveal, nasal, and temporal choroidal thicknesses were decreased as compared with those in the controls, but without statistically significant differences (p=0.534, p=0.437, and p=0.077, respectively). The mean total choroidal, stromal, and luminal areas and choroidal vascular index were statistically significantly decreased in the patient group (p<0.001, p=0.001, p=0.001, and p=0.003; respectively). At 4 months after remission, the choroidal structural parameters and choroidal vascular index revealed statistically significant increases as compared with the baseline measurements in the patients with COVID-19 (all p<0.001 and p=0.047, respectively). Conclusion: The choroidal vascular and stromal parameters showed significant transient decreases during the disease course of COVID-19. © This content is licensed under a Creative Commons Attributions 4.0 International License
Choroidal vascularity index and retinal nerve fiber layer reflectivity in newly diagnosed migraine patients
Purpose: To evaluate the choroidal structural parameters, peripapillary retinal nerve fiber layer (RNFL) thickness, and optic density index (ODI) and their correlations in patients with migraine. Methods: Twenty-eight newly diagnosed migraine patients and 28 age-matched healthy controls were included in this prospective cross-sectional study. The enhanced depth-optical coherence tomography images were evaluated. The choroidal area (CA) was binarized to the luminal area (LA) and stromal area (SA) using Image J. The choroidal vascularity index (CVI), the mean peripapillary RNFL thickness, superior-inferior-nasal-temporal quadrant RNFL thicknesses, and the ODI were compared statistically. Results: The difference in the mean CVI between the patient group and controls reached a statistical significance (p=0.035). The mean RNFL thickness was significantly decreased in patients with migraine compared with the controls (p=0.040). The mean RNFL thickness in the superior, temporal, and inferior quadrants was significantly decreased in the patient group in comparison to the control subjects (p=0.030, p=0.001, and p=0.022, respectively). There were no significant differences between the migraine group and the controls for the mean ODI of RNFL (p=0.399). Conclusion: The CVI and the RNFL thickness except for the nasal quadrant were significantly decreased in newly diagnosed migraine patients. © 2021 Elsevier B.V
The effect of magnesium added to levobupivacaine for femoral nerve block on postoperative analgesia in patients undergoing ACL reconstruction
Purpose The aim of this prospective randomised doubleblind
study is to investigate the effect of magnesium added
to local anaesthetics on postoperative VAS scores, total
opioid consumption, time to first mobilisation, patient
satisfaction and rescue analgesic requirements in arthroscopic
ACL reconstruction surgery.
Methods A total of 107 American Society of Anaesthesiologists
physical status grade I and II patients between 18
and 65 years of age who were scheduled to undergo elective
anterior crucial ligament (ACL) reconstruction with
hamstring autografts were enrolled in the study. The
patients were randomly allocated to Groups L (n = 51) and
LM (n = 56) using the closed-envelope method. Group
LM was administered 19 ml of 0.25 % levobupivacaine
and 1 ml of 15 % magnesium sulphate, while Group L was
administered 20 ml of 0.25 % levobupivacaine for femoral
blockade. General anaesthesia was administered using
laryngeal airway masks following neural blockade in both
groups. The patients were evaluated for heart rate and
mean arterial pressure, oxygen saturation, visual analogue
score (VAS), verbal rating scale (VRS), rescue analgesic
requirements, total opioid consumption, side effects and
time to first mobilisation at the 1st, 2nd, 4th, 6th, 12th and
24th hours postoperatively.
Results There was no statistically significant difference in
terms of demographic data, mean arterial pressure, heart
rate or oxygen saturation between groups. The area under
the curve VAS and VRS scores were lower at 4, 6, 12 and
24 h in Group LM (p = 0.001, p = 0.016, respectively).
The rescue analgesic requirement and the total opioid
consumption were significantly lower in Group LM
(p = 0.015, p = 0.019, respectively). The time to first
mobilisation and the Likert score (completely comfortable;
quite comfortable; slight discomfort; painful; very painful)
were higher, and the block onset time was lower in Group
LM (p = 0.014 and p = 0.012, respectively). There was
no difference in terms of side effects.
Conclusions The addition of magnesium to levobupivacaine
prolongs the sensory and motor block duration
without increasing side effects, enhances the quality of
postoperative analgesia and increases patient satisfaction;
however, the addition of magnesium delays the time to first
mobilisation and decreases rescue analgesic requirements
Phylogenetic relationships of Turkish indigenous donkey populations determined by mitochondrial DNA D-loop region
In this study, to analyze the mtDNA D-loop region and the origin of the maternal lineages of 16 different donkey populations, and to assess the domestication of Turkish indigenous donkeys in seven geographical regions, we investigated the DNA sequences of the D-loop region of 315 indigenous donkeys from Turkey. A total of 54 haplotypes, resulting from 35 polymorphic regions (27 parsimoniously informative and 6 singleton sites), were defined. Twenty-eight of these haplotypes are unique (51.85%), and 26 are shared among different Turkish indigenous donkey populations. The most frequent haplotype was Hap 1 (45.71%), followed by two haplotypes (Hap 4, 15.55% and Hap 7, 5.39%). The breed genetic diversity, evaluated by the haplotype diversity (HD ) and nucleotide diversity (?D ), for the Turkish donkey populations ranged from 0.533 ± 0.180 (Tekirdağ–Malkara, MAL) to 0.933 ± 0.122 (Aydin, AYD), and from 0.01196 ± 0.0026 (Antalya, ANT) to 0.02101 ± 0.0041 (Aydin, AYD), respectively. We observed moderate-to-high levels of haplotype diversity and moderate nucleotide diversity, indicating plentiful genetic diversity in all of the Turkish indigenous donkey populations. Phylogenetic analysis (NJT) and median-joining network analysis established that all haplotypes were distinctly grouped into two major haplogroups. The results of AMOVA analyses, based on geographic structuring of Turkish native donkey populations, highlighted that the majority of the observed variance is due to differences among samples within populations. The observed differences between groups were found to be statistically significant. Comparison among Turkish indigenous donkey mtDNA D-loop regions and haplotypes, and different countries’ donkey breeds and wild asses, identified two clades and which is named Somali (Clade IV) and Nubian (Clade V) lineages. The results can be used to understand the origin of Turkish donkey populations clearly, and to resolve the phylogenetic relationship among all of the different regions. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 215O555This research was funded by TUBITAK (The Scientific and Technological Research Council of Turkey), grant number 215O555, project leader Fulya ?zdil. The authors would like to kindly thank to Selen Yatkin who provide help during the sample collection. We are also grateful to all farmers and pastoralists for allowing us to use their animal to collect blood samples for free. Many thanks to our lab team ?eref M?cahit Topalo?lu and Ayla Fidan for helping laboratory experiment. The authors want to thank four anonymous reviewers for comments on this work
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