Statistical Significance and Leadership: Measure of Value or Misleading Number?

Author(s):  
Tiffany Danko
Author(s):  
N.J. Tao ◽  
J.A. DeRose ◽  
P.I. Oden ◽  
S.M. Lindsay

Clemmer and Beebe have pointed out that surface structures on graphite substrates can be misinterpreted as biopolymer images in STM experiments. We have been using electrochemical methods to react DNA fragments onto gold electrodes for STM and AFM imaging. The adsorbates produced in this way are only homogeneous in special circumstances. Searching an inhomogeneous substrate for ‘desired’ images limits the value of the data. Here, we report on a reversible method for imaging adsorbates. The molecules can be lifted onto and off the substrate during imaging. This leaves no doubt about the validity or statistical significance of the images. Furthermore, environmental effects (such as changes in electrolyte or surface charge) can be investigated easily.


2003 ◽  
Vol 73 (6) ◽  
pp. 439-445 ◽  
Author(s):  
Navia ◽  
Ortega ◽  
Requejo ◽  
Perea ◽  
López-Sobaler ◽  
...  

A study was conducted on the influence of maternal education level on food consumption, energy and nutrient intake, and dietary adequacy in 110 pre-school children from Madrid, Spain. With increasing maternal education, children consumed more sugar (p < 0.05), fruit (p < 0.05), and fish (p < 0.05). Snacking was more frequent with decreasing maternal education (p < 0.05). Though statistical significance was not reached, the consumption of pre-cooked foods was greater among children of mothers educated to a higher level, a phenomenon probably related to the work situation of these women. With respect to dietary composition, no significant differences were found between groups for macronutrient, fiber and energy intakes, except for energy supplied by polyunsaturated fatty acids (PUFA), which was greater in the children of less educated women (p < 0.01). This is probably due to their greater consumption of sunflower seed oil. The diets of children belonging to well-educated mothers came closer to meeting the recommended intakes for folate, vitamin C, and iodine. It would seem that maternal educational level influences the food habits of children. Mothers with less education may require special advice in this area.


VASA ◽  
2018 ◽  
Vol 47 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Artur I. Milnerowicz ◽  
Aleksandra A. Milnerowicz ◽  
Marcin Protasiewicz ◽  
Wiktor Kuliczkowski

Abstract. Background: Effectiveness of vascular closure devices during endovascular procedures requiring a direct puncture of a vascular prosthesis placed in the inguinal region is unknown. Patients and methods: The retrospective analysis included 134 patients with a history of polyethylene terephthalate (PETE) graft implantation in the inguinal region. In 20 (15 %) patients, haemostasis was achieved with manual compression, in 21 (16 %) with the StarClose™, and in 93 (69 %) with the AngioSeal™ device. Results: The incidence of vascular complications in the manual compression group was higher (at a threshold of statistical significance) than in the device closure group (45.0 vs. 24.5 %, p = 0.059). The difference was considered statistically significant when manual compression was compared with the AngioSeal™ closure group (45.0 vs. 13.9 %, p < 0.01). The vascular complication rate in the StarClose™ group was significantly higher than in the AngioSeal™ group (71.4 vs. 13.9 %, p < 0.000001). While haematomas were the only vascular complications observed after application of AngioSeal™, both haematomas and pseudoaneurysms were found in the StarClose™ group. Conclusions: The AngioSeal™ vascular closure device provides better local haemostasis than the StarClose™ device or manual compression during endovascular interventions requiring a direct puncture of PETE grafts


1996 ◽  
Vol 75 (02) ◽  
pp. 251-253 ◽  
Author(s):  
Manuel Monreal ◽  
Antoni Alastrue ◽  
Miquel Rull ◽  
Xavier Mira ◽  
Jordi Muxart ◽  
...  

SummaryCentral venous access devices are often essential for the administration of chemotherapy to patients with malignancy, but its use has been associated with a number of complications, mainly thrombosis. The true incidence of upper extremity deep vein thrombosis (DVT) in this setting is difficult to estimate since there are very few studies in which DVT diagnosis was based on objective tests, but its sequelae include septic thrombophlebitis, loss of central venous access and pulmonary embolism.We performed an open, prospective study in which all cancer patients who underwent placement of a long-term Port-a-Cath (Pharmacia Deltec Inc) subclavian venous catheter were randomized to receive or not 2500 IU sc of Fragmin once daily for 90 days. Venography was routinely performed 90 days after catheter insertion, or sooner if DVT symptoms had appeared. Our aims were: 1) to investigate the effectiveness of low doses of Fragmin in preventing catheter-related DVT; and 2) to try to confirm if patients with high platelet counts are at a higher risk to develop subclavian DVT, as previously suggested.On the recommendation of the Ethics Committee, patient recruitment was terminated earlier than planned: DVT developed in 1/16 patients (6%) taking Fragmin and 8/13 patients (62%) without prophylaxis (Relative Risk 6.75; 95% Cl: 1.05-43.58; p = 0.002, Fisher exact test). No bleeding complications had developed. As for prediction of DVT, there was a tendency towards a higher platelet count in those patients who subsequently developed DVT, but differences failed to reach any statistical significance (286 ±145 vs 207 ±81 X 109/1; p = 0.067). According to our experience, Fragmin at the dosage used proved to be both effective and safe in these patients.


1970 ◽  
Vol 24 (03/04) ◽  
pp. 450-460 ◽  
Author(s):  
H Yamazaki ◽  
T Odakura ◽  
K Takeuchi ◽  
T Sano

SummaryIn 382 patients, aged 21 to 76 years, including 39 healthy volunteers, a platelet count by Olef’s method, an adhesive platelet count by Moolten-Vroman’s method, prothrombin activity due to one-stage prothrombin time and calcium clotting time were measured. In 39 cases of myocardial infarction and 40 cases of cerebral thrombosis, both in acute stage, a marked decrease in the adhesive platelet count and adhesive index and an increase of prothrombin activity were observed with statistical significance compared to the healthy group (P < 0.01). In the recovery stage of myocardial infarction, cerebral thrombosis and other diseases, except for malignant tumors, acute infectious diseases, diabetes mellitus and blood or liver diseases, the above observations were absent or reduced. In the case of thrombosis, a negative correlation was seen between the adhesive platelet count and prothrombin activity (r — —0.238, P < 0.01). There is no correlation between the changes in platelet adhesiveness or blood coagulability and total cholesterol level in serum.


1997 ◽  
Vol 77 (02) ◽  
pp. 238-242 ◽  
Author(s):  
J Oldenburg ◽  
J K Picard ◽  
R Schwaab ◽  
H H Brackmann ◽  
E G D Tuddenham ◽  
...  

SummaryMolecular genetic studies have shown that development of antibodies to factor VIII (inhibitors) occurs most frequently in patients with severe haemophilia due to major gene lesions including inversions, stop codons and large deletions. Previous studies of HLA type were performed on inhibitor and non-inhibitor patients with diverse uncharacterised mutations which may have confounded detection of significant associations. We therefore selected a group of patients with a single mutation type, the prevalent intron 22 inversion, with or without inhibitors, to determine HLA genotype. Seventy-one such patients, 42 without and 29 with inhibitors (13 high, 9 low and 7 transient responders) were genotyped for MHC Class I HLA-A, -B, -C and Class II HLA-DQA, -DQB and -DRB loci. No strong correlation of any HLA-allele to inhibitor or non-inhibitor status was found. However, alleles of the haplotype HLA-A3, HLA-B7, HLA-C7, HLA-DQA0102, HLA-DQB0602, HLA-DR15 occurred more often in inhibitor patients. Since the alleles of this extended haplotype are common in the North European population only a very strong association would achieve statistical significance. Further studies of groups of patients similar to those studied here will be needed to confirm or exclude this association.


Author(s):  
Pawan Kumar Saini ◽  
Devendra Yadav ◽  
Rozy Badyal ◽  
Suresh Jain ◽  
Arti Singh ◽  
...  

Background: Psoriasis is an autoimmune chronic inflammatory disorder affecting the skin mediated by T-lymphocytes resulting in production of cytokines which cause hyperproliferation of keratinocytes.  Several factors and hormones like Prolactin have an action similar to these cytokines in promoting the multiplication of keratinocytes and other cells like lymphocytes and epithelial cells may have a role on the etiopathogenesis of psoriasis. Aim:-The aim of study is to compare the serum Prolactin levels in patients of psoriasis with a control group. Setting and study design: This is a case-control study conducted in the department of Dermatology, Venereology and Leprosy GMC, Kota over a period of 1year from July 2017 to June 2018 Material and method: The study included 100 cases of psoriasis (60 males and 40 females) and 100 controls similar for age and sex. Serum Prolactin levels were measured by ECLIA and results were obtained. Statistical analysis: Mean and standard deviation were calculated for each variable. Statistical significance of the results was analyzed using correlation analysis (Pearson correlation coefficient) and independent samples t-test. Statistical significance was assumed at p value<0.05. Result: Serum Prolactin level was significantly higher in cases of psoriasis compared to controls (p-value <0.001). PASI score and serum Prolactin levels were found to have a positive correlation (r value = 0.337; p-value: 0.001). No significant  correlation was found between serum levels of Prolactin and duration of disease r value= -0.034, P value =0.733). Serum Prolactin level was higher in male patients compared to females patients. Conclusion:- High serum Prolactin may be a biological marker of disease severity in psoriasis and may have a role in the pathogenesis of psoriasis. Further studies with large sample size are required to confirm this hypothesis.


MedPharmRes ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 27-32
Author(s):  
Bien Le ◽  
Dai Huynh ◽  
Mai Tuan ◽  
Minh Phan ◽  
Thao Pham ◽  
...  

Objectives: to evaluate the fluid responsiveness according to fluid bolus triggers and their combination in severe sepsis and septic shock. Design: observational study. Patients and Methods: patients with severe sepsis and septic shock who already received fluid after rescue phase of resuscitation. Fluid bolus (FB) was prescribed upon perceived hypovolemic manifestations: low central venous pressure (CVP), low blood pressure, tachycardia, low urine output (UOP), hyperlactatemia. FB was performed by Ringer lactate 500 ml/30 min and responsiveness was defined by increasing in stroke volume (SV) ≥15%. Results: 84 patients were enrolled, among them 30 responded to FB (35.7%). Demographic and hemodynamic profile before fluid bolus were similar between responders and non-responders, except CVP was lower in responders (7.3 ± 3.4 mmHg vs 9.2 ± 3.6 mmHg) (p 0.018). Fluid response in low CVP, low blood pressure, tachycardia, low UOP, hyperlactatemia were 48.6%, 47.4%, 38.5%, 37.0%, 36.8% making the odd ratio (OR) of these triggers were 2.81 (1.09-7.27), 1.60 (0.54-4.78), 1.89 (0.58-6.18), 1.15 (0.41-3.27) and 1.27 (0.46-3.53) respectively. Although CVP < 8 mmHg had a higher response rate, the association was not consistent at lower cut-offs. The combination of these triggers appeared to raise fluid response but did not reach statistical significance: 26.7% (1 trigger), 31.0% (2 triggers), 35.7% (3 triggers), 55.6% (4 triggers), 100% (5 triggers). Conclusions: fluid responsiveness was low in optimization phase of resuscitation. No fluid bolus trigger was superior to the others in term of providing a higher responsiveness, their combination did not improve fluid responsiveness as well.


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