A theory of well-connected relations

The simple concept of a well-connected relation (WCR) is defined and then developed into a theory for studying the structure of binary relations. Several interesting partitions of a binary relation are identified. It is shown that binary relations can be separated into families which form a hierarchy. Finally, concepts of universal algebra are extended to the family of “prime” relations. One application for the theory is in the logical design of data bases.     

On a characterization of α-entropy

We have characterized Havrada and Charvat [2] entropy by assuming a set of intuitive postulates and with the help of functional equations.     

Lattice disorder and electrical conductivity of flux-grown Ca(WO4) x (MoO4)1−x crystals

The growth of solid solutions of Ca(WO₄) _x (MoO₄)_1–x in the rangeX=0.072 to 0.86 has been successfully accomplished for the first time, employing a flux technique. The fact that proper mixing occurs is established by observing the variation in unit cell parameters and density of the crystals. The electrical conductivity of the pelletized samples is interpreted in terms of Schottky and Frenkel defect concentrations. The role of oxygen ion vacancies is stressed for the intrinsic region of conductivity.     

On the asymptotic stability of the solution of a linear viscoelastic continuous shaft

We study the vibrations of a whirling shaft which satisfies the linear viscoelastic stress-strain relation for a Kelvin model. The solution of the problem is obtained by using theory of Laplace transform, integral equations, compact operators and oscillating functions, it is shown that the model is asymptotically stable for ω² less than or equal to the least eigen-value of the system otherwise unstable, where ω is the frequency of the whirling shaft. The result is represented in the form of a stability theorem.     

IMPROVED MANPOWER UTILIZATION IN LIVE-RUN SHIFT OF NEWSPAPER PRINTING OPERATIONS

Operations of a typical metropolitan daily newspaper are studied, and a mathematical model is developed to minimize the total expected annual production cost of operations through choice of various controllable schemes. The identifiable heterogeneities within the system are exploited in a positive way. Varying sensitivity of customers to inclusion of the latest news, varying advertisers' desired distribution with in selected zones, and limited interest for die local news are handled by offering multiple editions of die newspaper. Production workload is also distributed between advance and live runs, allowing printing of only news-sensitive sections during live-runs. To reduce peak loads, the final selection of start and run times for sections of various editions during live-runs, are made around values prescribed by management.

The delays due to critical failures are avoided by adequately overdesigning press capacity, leaving only non-critical failures to affect delays. Recommendations are made for reducing non-critical failures.     

Two-port laparoscopic cholecystectomy: an innovative new method for gallbladder removal

This study was directed at defining the optimal in vitro screening methodology for the selection of new anti-myelogenous leukemia agents. Using thousands of samples of synthetic compounds from the Eastman Pharmaceutical, Inc. and Sterling Research Corporation (Eastman/Sterling) inventory, a number of sequential combinations of 8 cell lines were employed to optimize the model. The cells in these lines were of either murine (L1210 lymphocytic leukemia, C1498 myelogenous leukemia, and colony-forming unit-granulocyte macrophage [CFU-GM]) or human (HL-60, K-562, HEL, and THP-1 myelogenous leukemias, and CFU-GM) origin. The focus of the study was to find the most efficient and cost-effective manner in which to test compounds for both cytotoxicity against the tumor cells and for differential cytotoxicity against tumor as compared with normal cells.     

Ectopic pregnancy--changing trends

This study is an attempt to have an overall view of the changing trends in the clinical presentation, diagnostic modalities and management of ectopic pregnancy over a period of three and a half decades. The incidence of ectopic pregnancy was one in 368 during the 15-year period from 1959-1973 (group A) and has increased to one in 160 during the latter part of the study period from 1988-1993 (group B). Medical termination of pregnancy, abortion, intra-uterine contraceptive device and previous tubal ligation were the important risk factors recently (group B). Unruptured tubal pregnancy was diagnosed in 9.8% (group B) as compared to only 3% in group A. However, as most of the patients came to the hospital with disturbed pregnancy, the use of ultrasonography and urine gravindex test was helpful in only 14% in the latter part of the study. The characteristic clinical features like pain abdomen with amenorrhoea, vaginal bleeding and positive culdocentesis were the most reliable diagnostic criteria in both the groups. There is an increasing trend towards conserving the tubes and methotrexate use recently.     

Cloning of intestinal phospholipase A2 from intestinal epithelial RNA by differential display PCR

Differential display polymerase chain reaction (DD-PCR) is a powerful technique for comparing gene expression between cell types, or between stages of development or differentiation. Differentially expressed genes may be cloned and analysed further. Here we extend the use of DD-PCR to analyse differences in gene expression between two complex epithelia: that of the small intestine and of the large intestine. The aim of this study was to identify genes expressed preferentially in Paneth cells. Paneth cells are secretory epithelial cells putatively involved in host defense and regulation of crypt cell proliferation and are found at the base of the small intestinal crypts adjacent to the stem cell zone. Of 34 clones that were analysed, partial sequencing identified two clones related to known Paneth cell products: a homologue of secretory phospholipase A2 (clone B1) and a homologue of a neutrophil defensin (clone C5). B1 was strongly expressed in Paneth cells, as demonstrated by in-situ hybridization. B1 was also expressed at a lower level in the large intestinal epithelium. A full length B1 cDNA clone was isolated and sequenced, and shown to be highly homologous to type II secretory phospholipase A2 genes, and almost identical to the enhancing factor gene and the putative gene for the MOM-1 locus. B1 expression is limited to the intestinal tract, and we propose that it be designated intestinal phospholipase A2, or i-PLA2. The method we describe is well suited to the rapid identification of genes expressed exclusively or predominantly in Paneth cells.