On the Positive Correlation between DIF and Difficulty: A New Theory on the Correlation as Methodological Artifact

Author(s):  
Daniel M. Bolt ◽  
Xiangyi Liao
2004 ◽  
Vol 20 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Sara Holmberg ◽  
Anders Thelin ◽  
Eva-Lena Stiernström

Summary: The concept of “sense of coherence” (SOC) has been widely recognized since it was first introduced by Antonovsky. The originality and usefulness of the SOC scale and its relation to other psychosocial measures has been the subject of lively debate. The aim of this paper was to test for associations between SOC and work-related psychosocial factors (mainly the Job Demand-Control model), general living conditions, education, and social network factors. Cross-sectional data from a population-based sample of 1782 rural males from nine counties in Sweden were analyzed with a multiple regression technique. The subjects were occupationally active at inclusion and the mean age was 50 years (range 40-60). SOC was assessed with the original 29-item questionnaire. Psychosocial variables and lifestyle factors were assessed using questionnaires and structured interviews. The mean SOC among the subjects was 152.3 (standard deviation, 19.4). A strong negative correlation was found between SOC and job demand, whereas a positive correlation with job control was demonstrated. A positive correlation with general living conditions and with social support was also found. However, there was no correlation to education and occupation. Thus, SOC was shown to be strongly correlated to work-related psychosocial factors and social support, but independent of sociodemographic factors.


2013 ◽  
Vol 3 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Catherine Joseph ◽  
Suhasini Reddy ◽  
Kanwal Kashore Sharma

Locus of control (LOC), safety attitudes, and involvement in hazardous events were studied in 205 Indian Army aviators using a questionnaire-based method. A positive correlation was found between external LOC and involvement in hazardous events. Higher impulsivity and anxiety, and decreased self-confidence, safety orientation, and denial were associated with a greater number of hazardous events. Higher external LOC was associated with higher impulsivity, anxiety, and weather anxiety and with lower self-confidence, safety orientation, and denial. Internal LOC was associated with increased self-confidence, safety orientation, and denial. Hazardous events and self-confidence were higher in those involved in accidents than those not involved in accidents. Future research needs to address whether training can effectively modify LOC and negative attitudes, and whether this would cause a reduction in, and better management of, human errors.


2015 ◽  
Vol 122 (03) ◽  
Author(s):  
P Prinz ◽  
T Hofmann ◽  
A Ahnis ◽  
U Elbelt ◽  
M Goebel-Stengel ◽  
...  

1963 ◽  
Vol 03 (01) ◽  
pp. 25-38
Author(s):  
Manuel Tubis ◽  
William Blahd ◽  
John Endow

SummaryA study of the removal of I131-labeled Congo red from the blood of amyloid, non-amyloid, multiple myeloma, rheumatoid arthritis and other patients is presented. The percentage removal of the labeled dye shows the same variation reported by many other workers using Bennhold’s test and its modifications.However, there seems to be a positive correlation between the percentage removal of the labeled dye and the presence of amyloid as revealed by biopsy and autopsy. The half-time of disappearance is also correlated with the amyloidosis.The availability of the I131-labeled dye permits the use of very small weights of the dye thereby drastically reducing the possibility of toxic and sometimes fatal reactions encountered with the unlabeled dye. The I131 present permits easy quantitation of the dye in the blood without separation of plasma and obviates the need of fasting. It also permits external counting and scanning of deposits in the organs containing the dye.The availability and use of the labeled dye may stimulate more comparative studies of the removal of the dye from the blood correlated with biopsy and autopsy findings.


1987 ◽  
Vol 58 (03) ◽  
pp. 850-852 ◽  
Author(s):  
M B McCrohan ◽  
S W Huang ◽  
J W Sleasman ◽  
P A Klein ◽  
K J Kao

SummaryThe use of plasma thrombospondin (TSP) concentration was investigated as an indicator of intravascular platelet activation. Patients (n = 20) with diseases that have known vasculitis were included in the study. The range and the mean of plasma TSP concentrations of patients with vasculitis were 117 ng/ml to 6500 ng/ml and 791±1412 ng/ml (mean ± SD); the range and the mean of plasma TSP concentrations of control individuals (n = 33) were 13 ng/ml to 137 ng/ml and 59±29 ng/ml. When plasma TSP concentrations were correlated with plasma concentrations of another platelet activation marker, β-thromboglobulin (P-TG), it was found that the TSP concentration inei eased exponentially as the plasma β-TG level rose. A positive correlation between plasma levels of plasma TSP and serum fibrin degradation products was also observed. The results suggest that platelets are the primary source of plasma TSP in patients with various vasculitis and that plasma TSP can be a better indicator than β-TG to assess intravascular platelet activation due to its longer circulation half life.


1995 ◽  
Vol 73 (03) ◽  
pp. 429-434 ◽  
Author(s):  
Kazuomi Kario ◽  
Takefumi Matsuo ◽  
Reiko Asada ◽  
Toshiyuki Sakata ◽  
Hisao Kato ◽  
...  

SummaryWe compared factor VII clotting activity (FVIIc) assays using different thromboplastins to determine which is the most sensitive for activated FVII (FVIIa) or for FVII antigen (FVIIag). FVIIc levels were measured using thromboplastins derived from bovine brain (FVIIc Bov), human placenta (FVIIc Hum), and rabbit brain (FVIIc Rab). FVIIa levels were measured by fluorogenic assays using human soluble tissue factor (rsTF) or bovine rsTF. We also measured FVII activity by an amidolytic assay (FVIIc:am Hum) using human thromboplastin and a chromogenic substrate for thrombin. FVIIag levels were determined by ELISA. In the FVIIa assay, the reaction time obtained from using bovine rsTF was shorter than that with human rsTF, suggesting that the interaction of plasma FVIIa with bovine rsTF was stronger than with human rsTF. The plasma FVIIa levels measured using human rsTF and bovine rsTF were almost the same (r=0.947, p<0.0001). Among the three FVIIc assays, FVIIc Bov had the strongest positive correlation with the plasma FVIIa level (r=0.886, p<0.000l), but had no correlation with FVIIag. An increase of 1 ng/ml in the plasma FVIIa level yielded a 27.9% increase of FVIIc Bov. Plasma FVIIc Hum and FVIIc:am Hum showed moderate correlations with both FVIIa (r=0.520, p<0.02 and r=0.569, p<0.01, respectively) and FVIIag (r=0.438, p<0.05 and r=0.468, p<0.05, respectively). FVIIc Rab had the lowest correlation with FVIIa (r=0.367, p<0.1), but had a moderate correlation with FVIIag (r=0.436, p<0.05). After in vitro cold activation, FVIIc Bov levels increased the most and FVIIc:am levels showed the least change. These findings indicate that consideration of the thromboplastin used for assay is necessary when assessing the clinical significance of FVII activity as a cardiovascular risk factor.


Author(s):  
Shah Namrata Vinubhai ◽  
Pardeep Agarwal ◽  
Bushra Fiza ◽  
Ramkishan Jat

Background: Serum ferritin is known as an index for body iron stores also as an inflammatory marker and it is influenced by several disease. We were looking for a correlation between HbA1c and S. Ferritin in type 2 DM. Methodology: The present study a total of 150 participants were enrolled of which 100 were confirmed cases of Type 2 Diabetes Mellitus and rest 50 age and sex matched healthy subjects constituted the control group. All were screened for HbA1c, Fasting blood sugar, Post prandial blood sugar and S.Ferritin. Results: A highly significant variation and positive correlation was observed with respect to S.Ferritin and HbA1c levels. Mean S.Ferritin was high in the subgroup with poor glycemic control. Conclusion: The fasting, post prandial sugar levels, HbA1c and S.Ferritin were significantly higher in the diabetic subjects. This study shows a positive correlation between HbA1c and S. Ferritin levels. So we can conclude that in diabetic patients S. Ferritin may serve as an independent marker of poor glycemic and metabolic control. Keywords: Serum ferritin, Type 2 Diabetes Mellitus, HbA1c.


Author(s):  
Ol'ga Ptashec ◽  
Lyudmila Luchenok

The results of studies on the influence of agrotechnological techniques on the productivity of alfalfa (Medicago sativa), cultivation on agro-peat soils in the south of Belarus were presented. It was established that the yield of green mass on average over 4 years of life was 393.6–517.9 c / ha when sown under cover and 494.3–629.8 centners ha-1 with coverless sowing. Productivity — 56.5–75.1 and 69.5–89.7 centners ha-1, respectively. A positive correlation between the increase in the yield and productivity of the grass stand with an rise in the seeding rate and doses of fertilizers applied was noted.


2006 ◽  
Vol 54 (4) ◽  
pp. 425-430
Author(s):  
T. Árendás ◽  
L. C. Marton ◽  
P. Bónis ◽  
Z. Berzsenyi

The effect of varying weather conditions on the moisture content of the maize grain yield was investigated in Martonvásár, Hungary from late August to late September, and from the 3rd third of September to the 1st third of Novemberbetween 1999 and 2002. In every year a close positive correlation (P=0.1%) could be observed between the moisture content in late September and the rate of drying down in October. Linear regression was used each year to determine the equilibrium moisture content, to which the moisture content of kernels returned if they contained less than this quantity of water in late September and harvesting was delayed. In the experimental years this value ranged from 15.24-19.01%.


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