Wiener Number of Polyphenyls and Phenylenes

1994 ◽  
Vol 49 (11) ◽  
pp. 1040-1044 ◽  
Author(s):  
Ivan Gutman ◽  
Gyula Dömötör

Abstract It is shown that the values which the Wiener numbers of isomeric polyphenyls may assume are all congruent modulo 36. Similarly, the Wiener numbers of isomeric phenylens are always congruent modulo 18. These findings provide a rationalization for the known fact that the isomer-discriminating power of the Wiener number is rather weak. Extensions of the present results to more general classes of graphs are also pointed out.

1995 ◽  
Vol 74 (02) ◽  
pp. 673-679 ◽  
Author(s):  
C E Dempfle ◽  
S A Pfitzner ◽  
M Dollman ◽  
K Huck ◽  
G Stehle ◽  
...  

SummaryVarious assays have been developed for quantitation of soluble fibrin or fibrin monomer in clinical plasma samples, since this parameter directly reflects in vivo thrombin action on fibrinogen. Using plasma samples from healthy blood donors, patients with cerebral ischemic insult, patients with septicemia, and patients with venous thrombosis, we compared two immunologic tests using monoclonal antibodies against fibrin-specific neo-epitopes, and two functional tests based on the cofactor activity of soluble fibrin complexes in tPA-induced plasminogen activation. Test A (Enzymun®-Test FM) showed the best discriminating power among normal range and pathological samples. Test B (Fibrinostika® soluble fibrin) clearly separated normal range from pathological samples, but failed to discriminate among samples from patients with low grade coagulation activation in septicemia, and massive activation in venous thrombosis. Functional test C (Fibrin monomer test Behring) displayed good discriminating power between normal and pathological range samples, and correlated with test A (r = 0.61), whereas assay D (Coa-Set® Fibrin monomer) showed little discriminating power at values below 10 μg/ml and little correlation with other assays. Standardization of assays will require further characterization of analytes detected.


2019 ◽  
Vol 44 (3) ◽  
pp. 501-512
Author(s):  
S Sultana ◽  
HC Mohanta ◽  
Z Alam ◽  
S Naznin ◽  
S Begum

The article presents results of additive main effect and multiplicative interaction (AMMI) and genotype (G) main effect and genotype by environment (GE) interaction (G × GE) biplot analysis of a multi environmental trial (MET) data of 15 sweetpotato varieties released from Bangladesh Agricultural Research Institute conducted during 2015–2018. The objective of this study was to determine the effects of genotype, environment and their interaction on tuber yield and to identify stable sweetpotato genotypes over the years. The experimental layout was a randomized complete block design with three replications at Gazipur location. Combined analysis of variance (ANOVA) indicated that the main effects due to genotypes, environments and genotype by environment interaction were highly significant. The contribution of genotypes, environments and genotype by environment interaction to the total variation in tuber yield was about 60.16, 10.72 and 12.82%, respectively. The first two principal components obtained by singular value decomposition of the centred data of yield accounted for 100% of the total variability caused by G × GE. Out of these variations, PC1 and PC2 accounted for 71.5% and 28.5% of variability, respectively. The study results identified BARI Mistialu- 5, BARI Mistialu- 14 and BARI Mistialu- 15 as the closest to the “ideal” genotype in terms of yield potential and stability. Varieties ‘BARI Mistialu- 8, BARI Mistialu- 11 and BARI Mistialu- 12’ were also selected as superior genotypes. BARI Mistialu- 3 and BARI Mistialu- 13 was comparatively low yielder but was stable over the environment. Among them BARI Mistialu-12, BARI Mistialu-14 and BARI Mistialu-15 are rich in nutrient content while BARI Mistialu-8 and BARI Mistialu-11 are the best with dry matter content and organoleptic taste. Environments representing in 1st and 3rd year with comparatively short vectors had a low discriminating power and environment in 2nd year was characterized by a high discriminating power. Bangladesh J. Agril. Res. 44(3): 501-512, September 2019


2017 ◽  
Vol 10 (03) ◽  
pp. 1750057
Author(s):  
Abdollah Alhevaz ◽  
Maryam Baghipur ◽  
Sadegh Rahimi

The Wiener number [Formula: see text] of a graph [Formula: see text] was introduced by Harold Wiener in connection with the modeling of various physic-chemical, biological and pharmacological properties of organic molecules in chemistry. Milan Randić introduced a modification of the Wiener index for trees (acyclic graphs), and it is known as the hyper-Wiener index. Then Klein et al. generalized Randić’s definition for all connected (cyclic) graphs, as a generalization of the Wiener index, denoted by [Formula: see text] and defined as [Formula: see text]. In this paper, we establish some upper and lower bounds for [Formula: see text], in terms of other graph-theoretic parameters. Moreover, we compute hyper-Wiener number of some classes of graphs.


Res Publica ◽  
1975 ◽  
Vol 17 (4) ◽  
pp. 457-470
Author(s):  
Guido Dierickx

This contribution should be seen as an attempt to retrieve information from restcategories, such as «does not know» and «no answer».  From these, and from other data as well, we constructed 10, mostly summating, indexes of political ignorance. Among them is an index of objective ignorance, that is about political events, persons and situations.  The others aim at more subjective dimensions. Does the respondent feel informed about the political process : about government and party performance, partisan congeniality, modalities of voting, local politics social problems, political issues ?There seems to be some evidence in favor of the following hypotheses.1. The indexes tend to compensate each other: respondents who score low on one index, do not necessarily score low on the next one.2. I t is difficult to ascertain the validity of an index of objective ignorance. Moreover it does by no means express all the (relevant) dimensions of political information.3. A mong indexes of subjective ignorance one should distinguish between «policy» and «political» information ; the latter seems to refer to a situation where strictly political rules of the game, a.o. those of political conflict, prevail.4. Of all indexes the «political issues» index showed the most discriminating power, as well as the most expected associations.


2021 ◽  
pp. 9-10
Author(s):  
Bhoomika R. Chauhan ◽  
Jayesh Vaza ◽  
Girish R. Chauhan ◽  
Pradip R. Chauhan

Multiple choice questions are nowadays used in competitive examination and formative assessment to assess the student's eligibility and certification.Item analysis is the process of collecting,summarizing and using information from students' responses to assess the quality of test items.Goal of the study was to identify the relationship between the item difficulty index and item discriminating index in medical student's assessment. 400 final year medical students from various medical colleges responded 200 items constructed for the study.The responses were assessed and analysed for item difficulty index and item discriminating power. Item difficulty index an item discriminating power were analysed by statical methods to identify correlation.The discriminating power of the items with difficulty index in 40%-50% was the highest. Summary and Conclusion:Items with good difficulty index in range of 30%-70% are good discriminator.


Sign in / Sign up

Export Citation Format

Share Document