Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 49
Filter
1.
Int J Occup Saf Ergon ; 29(2): 555-561, 2023 Jun.
Article in English | MEDLINE | ID: mdl-35343402

ABSTRACT

In this study, the approaches of employees in marine fish hatcheries to occupational health and safety were determined. Cronbach's α coefficient was calculated as 0.858 in the reliability of the scale and scale factors based on internal consistency. In addition,factor analysis according to the varimax method was found to be approximately 64%. It was determined that 68% of the employees were not aware of the relevant laws. In addition,85% of the employees are aware of the dangers and risks in their workplaces. In the event of a negative situation in the workplace,the rate of those who know their legal rights is 73% (p ≤ 0.05). In addition,91% of the employees stated that they would use their right to object in a risky situation and quit the job. Sixty per cent of the employees stated that their jobs can satisfy them sociologically and economically throughout their life.


Subject(s)
Occupational Health , Animals , Reproducibility of Results , Fisheries , Workplace , Occupations , Surveys and Questionnaires
2.
Niger J Clin Pract ; 21(9): 1150-1157, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30156200

ABSTRACT

OBJECTIVE: The purpose of this study was to investigate the clinical effects of erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser treatment as a complementary to scaling and root planning (SRP) during the treatment of chronic periodontitis and gingival crevicular fluid (GCF) interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), and interleukin-35 (IL-35) levels. MATERIALS AND METHODS: Forty patients with chronic periodontitis were divided into two equal groups at random to receive SRP alone and SRP followed by Er, Cr: YSGG laser treatment, which are control and test groups, respectively. Clinical attachment level (CAL), probing depth (PD), bleeding on probing (BOP), gingival index (GI), and plaque index (PI) were measured for all patients in both groups at baseline and again at the end of the 1st, 3rd, and 6th months following the treatment. Levels of GCF IL-1ß, IL-6, and IL-35 were analyzed by enzyme-linked immunosorbent assay. RESULTS: After periodontal treatment, CAL, PD, BOP, GI, and PI, which are clinical parameters analyzed, decreased significantly (P < 0.05) in both test and control groups. GCF volume, IL-1 ß, IL-6, and IL-35, levels in both groups proved statistically significant reductions compared to the baseline (P < 0.05), but no substantial variations were detected among both groups. CONCLUSION: According to these results, we can suggest that IL-35 may be related to the pathogenesis of periodontitis and that Er, Cr: YSGG laser can be used as an adjunct to SRP in periodontal treatment.


Subject(s)
Chromium/therapeutic use , Dental Scaling , Erbium/therapeutic use , Laser Therapy/methods , Lasers, Solid-State/therapeutic use , Periodontitis/therapy , Root Planing , Adult , Dental Care , Enzyme-Linked Immunosorbent Assay , Female , Gallium , Gingival Crevicular Fluid/metabolism , Humans , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Interleukins/metabolism , Male , Middle Aged , Periodontal Index , Periodontitis/diagnosis , Scandium , Yttrium
3.
Crit Rev Food Sci Nutr ; 57(4): 701-717, 2017 Mar 04.
Article in English | MEDLINE | ID: mdl-25751069

ABSTRACT

Drying is one of the widely used methods of grain, fruit, and vegetable preservation. The important aim of drying is to reduce the moisture content and thereby increase the lifetime of products by limiting enzymatic and oxidative degradation. In addition, by reducing the amount of water, drying reduces the crop losses, improves the quality of dried products, and facilitates its transportation, handling, and storage requirements. Drying is a process comprising simultaneous heat and mass transfer within the material, and between the surface of the material and the surrounding media. Many models have been used to describe the drying process for different agricultural products. These models are used to estimate drying time of several products under different drying conditions, and how to increase the drying process efficiency and also to generalize drying curves, for the design and operation of dryers. Several investigators have proposed numerous mathematical models for thin-layer drying of many agricultural products. This study gives a comprehensive review of more than 100 different semitheoretical and empirical thin-layer drying models used in agricultural products and evaluates the statistical criteria for the determination of appropriate model.


Subject(s)
Dehydration , Edible Grain/chemistry , Food Preservation/methods , Fruit/chemistry , Vegetables/chemistry , Models, Theoretical
4.
Animal ; 11(3): 375-381, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27510851

ABSTRACT

Ultrasound scanning traits have been adapted in selection programs in many countries to improve carcass traits for lean meat production. As the genetic parameters of the traits interested are important for breeding programs, the estimation of these parameters was aimed at the present investigation. The estimated parameters were direct and maternal heritability as well as genetic correlations between the studied traits. The traits were backfat thickness (BFT), skin+backfat thickness (SBFT), eye muscle depth (MD) and live weights at the day of scanning (LW). The breed investigated was Kivircik, which has a high quality of meat. Six different multi-trait animal models were fitted to determine the most suitable model for the data using Bayesian approach. Based on deviance information criterion, a model that includes direct additive genetic effects, maternal additive genetic effects, direct maternal genetic covariance and maternal permanent environmental effects revealed to be the most appropriate for the data, and therefore, inferences were built on the results of that model. The direct heritability estimates for BFT, SBFT, MD and LW were 0.26, 0.26, 0.23 and 0.09, whereas the maternal heritability estimates were 0.27, 0.27, 0.24 and 0.20, respectively. Negative genetic correlations were obtained between direct and maternal effects for BFT, SBFT and MD. Both direct and maternal genetic correlations between traits were favorable, whereas BFT-MD and SBFT-MD had negligible direct genetic correlation. The highest direct and maternal genetic correlations were between BFT and SBFT (0.39) and between MD and LW (0.48), respectively. Our results, in general, indicated that maternal effects should be accounted for in estimation of genetic parameters of ultrasound scanning traits in Kivircik lambs, and SBFT can be used as a selection criterion to improve BFT.


Subject(s)
Breeding , Meat/analysis , Phenotype , Sheep, Domestic/physiology , Ultrasonography/veterinary , Animals , Bayes Theorem , Female , Male , Models, Genetic , Sheep, Domestic/genetics , Turkey
5.
Surg Radiol Anat ; 36(6): 527-36, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24154635

ABSTRACT

PURPOSE: The configurations of cerebral veins and dural venous sinuses differ not only between individuals, but also between the two brain hemispheres of an individual, making the anatomical classification of the cerebral veins difficult. We evaluated the superior dural venous sinuses and classified their types and variations using magnetic resonance venography (MRV) and digital substraction angiography (DSA). METHODS: A total of 394 patients were studied retrospectively. Superior dural venous sinuses were evaluated and the confluence of the sinuses was classified on 2-dimensional time-of-flight MRV, contrast-enhanced 3-dimensional spoiled gradient recalled echo magnetic resonance imaging, and/or cerebral DSA. Confluens sinuum was divided into three types: true confluence, partial confluence, and non-confluence. RESULTS: Of the three types, partial confluence (type II) was most frequently seen. Co-dominance of the transverse sinuses was most frequently observed. An occipital sinus was observed in 15 % of the patients. There were statistically significant differences between the left transverse sinus agenesis and the presence of the occipital sinus (p < 0.001), between the co-presence of the partial confluence type torcular and the occipital sinus (p = 0.040), and between the co-presence of the fenestrated straight sinus and the occipital sinus (p = 0.010). CONCLUSIONS: Although anatomical variations of dural venous sinuses are seen frequently, classification of venous sinuses helps surgeons in preoperative evaluation and management, and prevention of possible complications. In this study, we think that a comprehensive evaluation and classification of dural venous sinuses is a significant contribution to the literature.


Subject(s)
Angiography, Digital Subtraction/methods , Cerebral Angiography/methods , Cerebral Veins/abnormalities , Cerebral Veins/diagnostic imaging , Intracranial Arteriovenous Malformations/diagnosis , Magnetic Resonance Angiography/methods , Adolescent , Adult , Aged , Aged, 80 and over , Cerebral Veins/anatomy & histology , Child , Contrast Media , Cranial Sinuses , Echo-Planar Imaging/methods , Female , Humans , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Male , Middle Aged , Observer Variation , Retrospective Studies , Young Adult
6.
Anaesthesia ; 68(5): 492-6, 2013 May.
Article in English | MEDLINE | ID: mdl-23573844

ABSTRACT

We measured forces generated by Macintosh and GlideScope(®) laryngoscope blades during airway intubation by 16 participants in four manikins: Laerdal(®) SimMan; TruCorp AirSim™ Advance; Laerdal(®) Airway Management Trainer; and Ambu(®) Airway Man. Both laryngoscopes generated the least force in the Laerdal Airway Management Trainer and the most in the Ambu Airway Man. The respective median (IQR [range]) forces generated by the Macintosh blade were 2 (1-4 [1-7]) N vs 9 (7-13 [5-16]) N, p = 0.00004, with peak forces 9 (5-11 [3-16]) N vs 18 (12-22 [3-31]) N, p = 0.0004. The respective average and peak forces generated by the GlideScope blade were 1 (1-2 [0-3]) N vs 4 (3-5 [2-6]) N, p = 0.00001, and 4 (2-7 [0-12]) N vs 7 (4-9 [3-18]) N, p = 0.054.


Subject(s)
Anesthesiology/education , Laryngoscopes , Manikins , Airway Management , Algorithms , Humans , Inservice Training/methods , Laryngoscopy
7.
J Psychiatr Ment Health Nurs ; 19(3): 193-202, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22260727

ABSTRACT

This methodological study was planned to translate the Wijma Delivery Expectancy/Experience Questionnaire (W-DEQ) into Turkish and to investigate its reliability for both nulliparous and parous women in Turkish population. A total of 660 healthy women with normal pregnancies at gestational ages of between 28 and 40 weeks were recruited. The internal consistency reliability (Cronbach's α) was used for determining the reliability of the W-DEQ. Construct validity was also determined utilizing the known-groups method. In this study, independent sample t-tests were used to compare the nulliparous and parous groups differing in known fear status. In order to test the construct of the W-DEQ, Beck Anxiety Inventory, Depression Anxiety and Stress Scale and Brief Measure of Worry Severity scales were chosen as these scales are expected to correlate with the W-DEQ. Analysis of the construct validity of the W-DEQ version A using Pearson's correlation coefficients was performed for both nulliparous and parous women separately. All the scales in both groups showed a statistically significant correlation with the W-DEQ. The alpha coefficient (0.89) is well above the 0.70 criterion for internal consistency reliability. Turkish form of Wijma Delivery Expectancy/Experience Questionnaire Version A was fixed as reliable and valid means to measure the level of fear of childbirth among Turkish pregnants.


Subject(s)
Delivery, Obstetric/psychology , Fear , Parturition/psychology , Pregnancy/psychology , Surveys and Questionnaires , Adolescent , Adult , Female , Humans , Psychometrics , Reproducibility of Results , Turkey , Young Adult
8.
Anaesth Intensive Care ; 39(6): 1098-102, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22165365

ABSTRACT

The force applied during laryngoscopy can cause local tissue trauma and can induce cardiovascular responses and cervical spine movement in susceptible patients. Previous studies have identified numerous operator and patient factors that influence the amount of force applied during intubation. There are few studies evaluating the effect of different laryngoscope blades and no study involving video laryngoscopes. In this study we measured the forces using two laryngoscopic techniques. Three FlexiForce Sensors (A201-25, Tekscan, Boston, MA, USA) were attached to the concave blade surface of a Macintosh and a GlideScope laryngoscope. Experienced anaesthetists performed Macintosh and GlideScope intubations on the Laerdal Airway Management Trainer manikin. Compared to Macintosh intubations, the GlideScope intubations had equal or superior views of the glottis with 55%, 58% and 66% lower median peak, average and impulse forces applied to the tongue base. The distal sensor registered the most force in both devices and the force distribution pattern was similar between the devices. The findings suggest that the GlideScope requires less force for similar or better laryngoscopic views, at least in a manikin model.


Subject(s)
Laryngoscopes , Laryngoscopy/methods , Manikins , Airway Management , Humans , Intubation, Intratracheal/methods , Tongue/physiology
9.
Ann Hepatol ; 9(2): 161-5, 2010.
Article in English | MEDLINE | ID: mdl-20526009

ABSTRACT

INTRODUCTION: Elevated aminotransferase levels(ATLs) are alert the physicians for liver-affecting disease and may reflect liver injury. We aimed to determine the prevalence of elevated ATLs and the association of elevated ATLs with the metabolic syndrome (MetS) in a northern province of Turkey. MATERIALS AND METHODS: Elevated ATLs were evaluated among 1,095 individuals of the Tokat Prevalence Study which have been described in detail elsewhere. 1,095 participants had been selected by a simple random sampling method among 530,000 inhabitants in 70 (12 urban and 58 rural) areas in the province of Tokat which is located in the Black Sea Region of Turkey. RESULTS: The prevalence of elevated serum ALT, AST, and ALT and/or AST were found as 11%, 7.2%, and 13.3%, respectively. Increased BMI, fatty liver, and MetS were higher in our general population with elevated ATLs. After exclusion of individuals with hepatitis B or hepatitis C infection, 132 individuals with elevated ATLs (91 male and 41 female) were evaluated. MetS was found in 59 participants and its prevalence was markedly higher in females with elevated ATLs (p < 0.0001). When the males with elevated ATLs were evaluated, the ALT levels of the persons who have no risk of MetS (p =0.007) and the persons who have one risk of MetS (p = 0.001) were lower than the persons with MetS. CONCLUSIONS: Elevated ATLs are common and it's an important cause is MetS in Northern Turkey.


Subject(s)
Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Metabolic Syndrome/enzymology , Metabolic Syndrome/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Chi-Square Distribution , Female , Humans , Male , Middle Aged , Prevalence , Risk Assessment , Risk Factors , Turkey/epidemiology , Up-Regulation , Young Adult
10.
Br Poult Sci ; 50(1): 33-8, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19234927

ABSTRACT

1. The effect of intermittent partial surface wetting on body and surface temperature were investigated at 62 and 20 weeks of age in domestic laying hens of ATABEY (white) and ATAK (brown) strains. 2. The number of control and treatment birds was 96, half of which were 62 weeks of age and the remainder 20-week-old birds. 3. Sprinkling was done on the head, head appendages, neck and dorsal surface by releasing 10 ml/bird in a sprinkling session. The control birds were not sprinkled at any time. 4. The first measurement was carried out immediately before sprinkling, the second just after sprinkling, and measurements were then repeated every 5 min until the end of the 20th min. 5. Partial surface sprinkle cooling had a positive effect in relieving the birds of heat stress. The treatment birds had lower core body, head and dorsal surface temperatures than the control birds. 6. The treatment effect on egg production was significant in young birds but not in the older ones.


Subject(s)
Body Temperature/physiology , Chickens/physiology , Oviposition/physiology , Water , Animals , Eggs , Female , Hot Temperature , Random Allocation , Wettability
12.
Poult Sci ; 87(12): 2441-50, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19038798

ABSTRACT

This study investigated the efficacy of surface wetting at different thermal conditions on core body, head, and dorsal surface temperatures in laying hens. Hens were sprinkled on the head and dorsal surface by releasing a sprinkling dosage of 10 mL.bird(-1). The first measurement was taken presprinkling, and the second was taken immediately postsprinkling and then repeated every 5 min for 20 min. The cooling water needs for intermittent partial surface wetting to relieve acute heat stress in the laying hens were quantified for 48 domestic laying hens under 4 experimental thermal conditions. The hens were kept at 4 thermal conditions at average dry-bulb temperatures of 31.30 +/- 0.03, 33.20 +/- 0.08, 36.01 +/- 0.12, and 40.24 +/- 0.08 degrees C; RH of 67.68 +/- 0.37, 51.78 +/- 1.98, 24.59 +/- 0.90, and 16.12 +/- 1.55%; and air velocities of 0.09 +/- 0.00, 0.07 +/- 0.00, 0.08 +/- 0.00, and 0.09 +/- 0.00 m.s(-1), respectively. The differences in core body, head, and dorsal surface temperatures among the 4 thermal groups were 0.15, 0.18, 0.23, and 0.22 degrees C for core body temperature; 1.63, 1.44, 2.51, and 0.97 degrees C for core head temperature; and 1.23, 1.37, 1.41, and 0.64 degrees C for core dorsal temperature at thermal conditions 1, 2, 3, and 4, respectively. There were significant differences in core body, head, and dorsal surface temperatures among the 4 thermal condition groups. It was concluded that the spraying interval was directly proportional to the product of the vapor pressure deficit and the thermal resistance of convective mass transfer of the wetted hens, because there were no significant differences in the air velocity among the 4 thermal condition groups and the air velocity was very low.


Subject(s)
Body Temperature , Chickens/physiology , Hot Temperature , Water , Animal Husbandry , Animals , Body Weight , Female , Housing, Animal , Time Factors
13.
J Comput Assist Tomogr ; 32(4): 660-1, 2008.
Article in English | MEDLINE | ID: mdl-18664858

ABSTRACT

We report the first case of unilateral incus agenesis in the literature. Preoperative diagnosis by virtual endoscopy further enhances the significance of this case. We present thin-section temporal bone computed tomographic images and 3-dimensional reconstructed views which were all correlated with intraoperative findings. The patient was successfully treated with an ossicular prosthesis replacement.


Subject(s)
Endoscopy/methods , Hearing Loss/congenital , Hearing Loss/diagnosis , Incus/abnormalities , Incus/diagnostic imaging , Tomography, X-Ray Computed/methods , Adolescent , Female , Hearing Loss/surgery , Humans , Imaging, Three-Dimensional/methods , Incus/surgery , Prosthesis Implantation , Rare Diseases , Temporal Bone/diagnostic imaging
14.
Neuroradiol J ; 21(2): 275-8, 2008 Apr 07.
Article in English | MEDLINE | ID: mdl-24256841

ABSTRACT

Carotid artery dissection is usually unilateral. Rarely bilateral forms can be seen. Recent studies have shown the efficacy of computed tomography angiography (CTA) in the diagnosis of carotid dissection. Herein we report a case with bilateral carotid artery dissection diagnosis and follow-up which was carried out using mainly CTA.

15.
Interv Neuroradiol ; 14(4): 457-60, 2008 Dec 29.
Article in English | MEDLINE | ID: mdl-20557747

ABSTRACT

SUMMARY: We describe a patient with a small ruptured azygos anterior cerebral artery aneurysm located at a non-bifurcation distal site on the artery treated successfully with simple coiling.

16.
Interv Neuroradiol ; 14(1): 97-100, 2008 Mar 30.
Article in English | MEDLINE | ID: mdl-20557791

ABSTRACT

SUMMARY: We present imaging findings of a patient with an incomplete form of the PHACES syndrome with dolichosegmental intracranial arteries as the predominant component, and discuss the etiopathological and clinical significance of this finding.

17.
Diagn Interv Radiol ; 13(3): 105-8, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17846982

ABSTRACT

PURPOSE: Restrictions with computed tomography angiography (CTA) regarding the visualization of arteries near the skull base are well known. Today, the gold standard for overcoming this is the matched mask bone elimination method. Worldwide use of this method is limited since it requires advanced imaging physics and software. A more simple method was introduced recently that avoided motion artifacts significantly by restraining the patient's head with a vacuum-type head holder. The purpose of this study was to investigate the feasibility of using unregistered subtracted CTA without such head-holding methods. MATERIALS AND METHODS: Of the 42 patients that underwent subtracted CTA, 39 were recruited for this study. Two patients were excluded due to agitation during examination and one due to artifacts of an embolized aneurysm. All the examinations were performed in an 8-channel multidetector CT suite. After performing a non-contrast low-dose CT examination, CTA was carried out using the same scan planes as on the scout images. Images were transferred to a workstation and subtraction was performed. Hard-copy images through identical locations were reviewed by 2 observers, a radiologist and a clinician (neurologist), and visualization of the internal carotid artery and posterior artery systems were scored. Data were analyzed using the Wilcoxon signed-rank test. RESULTS: Significant statistical differences, in favor of subtracted images, were noted in both observers' scores, both for the internal carotid artery and posterior system arteries. The differences in the clinician's scores were more prominent than that of radiologist's. CONCLUSION: These results are promising for the expanded use of the subtraction method, especially in radiology departments that lack the staff and equipment for registered methods.


Subject(s)
Carotid Artery, Internal/diagnostic imaging , Intracranial Aneurysm/diagnostic imaging , Skull Base , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Angiography, Digital Subtraction , Cerebral Angiography , Female , Humans , Male , Middle Aged , Predictive Value of Tests
18.
Neuroradiol J ; 20(3): 287-90, 2007 Jun 30.
Article in English | MEDLINE | ID: mdl-24299668

ABSTRACT

Fat embolism syndrome is a rare, but life-threatening problem and is usually associated with severe trauma. Neurological symptoms are variable, and the clinical diagnosis is difficult. We describe a patient with fat density lesions on cranial CT sections and discuss the etiopathogenesis of cerebral fat embolism (CFE) in this patient who does not have a history of long bone fracture, but metastatic lung disease and empyema. This is probably the first case report of CFE secondary to pleural irrigation of empyema with demonstrative CT findings.

19.
Mikrobiyol Bul ; 40(3): 169-77, 2006 Jul.
Article in Turkish | MEDLINE | ID: mdl-17001845

ABSTRACT

Treatment of life threatening pneumococcal infections such as meningitis has recently become problematic due to the emergence of antibiotic resistant strains. Antimicrobial susceptibility data usually derived from the studies that included all clinical pneumococcal isolates. However, resistance patterns of this microorganism isolated from meningitis cases in our country are not exactly known. The aim of this study was to determine the antimicrobial susceptibility and serotypes of Streptococcus pneumoniae strains isolated from meningitis cases. This retrospective study was designed in three university hospitals in Turkey and 72 pneumococci isolated from patients with meningitis were evaluated. In this study disk diffusion test and E-test methods were used to determine the susceptibility of pneumococci to some antibiotics. All S. pneumoniae isolates were serotyped using Quellung reaction. Although resistance for oxacillin was found by disc diffusion method in 11 isolates, only six of them were found to be resistant by E-test. By the latter procedure, no resistance was recorded against ceftriaxone and meropenem, while chloramphenicol resistance was found as 1.4%. In our study, erythromycin, ciprofloxacin and levofloxacin resistance were 2.8%, TMP-SMX resistance was 26.4%, while no vancomycin resistance was detected by disk diffusion. In evaluation of 72 pneumococci, we found 16 different serotypes and four isolates could not be serotyped. The serogroup 23 (n: 19) was the most common one followed by serotype 19 (n: 9) and serotype 14 (n: 7). Of six resistant isolates, three pneumococci were serogroup 23 and the remaining were from three different serotype/serogroups 11, 14 and 19. As a result penicillin resistance in pneumococci isolated from meningitis was low and there was no resistance to ceftriaxone. It seems that ceftriaxone is an appropriate choice for empirical treatment of meningitis in our patients. These findings also revealed that pneumococcal polysaccharide capsule vaccines in use cover most of the invasive pneumococcal serotypes.


Subject(s)
Anti-Infective Agents/pharmacology , Meningitis, Pneumococcal/microbiology , Streptococcus pneumoniae/drug effects , Adolescent , Adult , Anti-Infective Agents/therapeutic use , Child , Child, Preschool , Drug Resistance, Bacterial , Humans , Infant , Infant, Newborn , Meningitis, Pneumococcal/drug therapy , Microbial Sensitivity Tests/methods , Middle Aged , Retrospective Studies , Serotyping , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/isolation & purification , Turkey
20.
Genetics ; 172(3): 1955-65, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16322505

ABSTRACT

A linkage disequilibrium-based method for fine mapping quantitative trait loci (QTL) has been described that uses similarity between individuals' marker haplotypes to determine if QTL alleles are identical by descent (IBD) to model covariances among individuals' QTL alleles for a mixed linear model. Mapping accuracy with this method was found to be sensitive to the number of linked markers that was included in the haplotype when fitting the model at a putative position of the QTL. The objective of this study was to determine the optimal haplotype structure for this IBD-based method for fine mapping a QTL in a previously identified QTL region. Haplotypes consisting of 1, 2, 4, 6, or all 10 available markers were fit as a "sliding window" across the QTL region under ideal and nonideal simulated population conditions. It was found that using haplotypes of 4 or 6 markers as a sliding "window" resulted in the greatest mapping accuracy under nearly all conditions, although the true IBD state at a putative QTL position was most accurately predicted by IBD probabilities obtained using all markers. Using 4 or 6 markers resulted in greater discrimination of IBD probabilities between positions while maintaining sufficient accuracy of IBD probabilities to detect the QTL. Fitting IBD probabilities on the basis of a single marker resulted in the worst mapping accuracy under all conditions because it resulted in poor accuracy of IBD probabilities. In conclusion, for fine mapping using IBD methods, marker information must be used in a manner that results in sensitivity of IBD probabilities to the putative position of the QTL while maintaining sufficient accuracy of IBD probabilities to detect the QTL. Contrary to expectation, use of haplotypes of 4-6 markers to derive IBD probabilities, rather than all available markers, best fits these criteria. Thus for populations similar to those simulated here, optimal mapping accuracy for this IBD-based fine-mapping method is obtained with a haplotype structure including a subset of all available markers.


Subject(s)
Haplotypes , Linkage Disequilibrium , Physical Chromosome Mapping/methods , Quantitative Trait Loci , Crosses, Genetic , Gene Frequency , Genetic Markers , Genetic Variation , Genetics, Population , Models, Genetic
SELECTION OF CITATIONS
SEARCH DETAIL
...