Parity of Sets of Mutually Orthogonal Latin Squares

Every Latin square has three attributes that can be even or odd, but any two of these attributes determines the third. Hence the parity of a Latin square has an information content of 2 bits. We extend the definition of parity from Latin squares to sets of mutually orthogonal Latin squares (MOLS) and the corresponding orthogonal arrays (OA). Suppose the parity of an $\mathrm{OA}(k,n)$ has an information content of $\dim(k,n)$ bits. We show that $\dim(k,n) \leq {k \choose 2}-1$. For the case corresponding to projective planes we prove a tighter bound, namely $\dim(n+1,n) \leq {n \choose 2}$ when $n$ is odd and $\dim(n+1,n) \leq {n \choose 2}-1$ when $n$ is even. Using the existence of MOLS with subMOLS, we prove that if $\dim(k,n)={k \choose 2}-1$ then $\dim(k,N) = {k \choose 2}-1$ for all sufficiently large $N$. Let the ensemble of an $\mathrm{OA}$ be the set of Latin squares derived by interpreting any three columns of the OA as a Latin square. We demonstrate many restrictions on the number of Latin squares of each parity that the ensemble of an $\mathrm{OA}(k,n)$ can contain. These restrictions depend on $n\mod4$ and give some insight as to why it is harder to build projective planes of order $n \not= 2\mod4$ than for $n \not= 2\mod4$. For example, we prove that when $n \not= 2\mod 4$ it is impossible to build an $\mathrm{OA}(n+1,n)$ for which all Latin squares in the ensemble are isotopic (equivalent to each other up to permutation of the rows, columns and symbols)

Diversification of Fish Culture and Exports among Major Shrimp-producing Countries of Asia: A Spatial and Temporal Analysis

Asian countries contribute nearly 90 per cent to global production of culture fisheries. Diversification of species is not happening in fish culture because of the high value shrimp commands in the export market. Shrimp farming is on the increase in all the major shrimp-producing Asian countries. Higher the growth in shrimp production, higher is the instability in production due to production risks associated with ecosystem complexities and disease incidences. Most of the shrimp-producing countries have been moving towards specialization of shrimp production for export because of the high price that the shrimp asserts in the international market. A comparison between the Asian countries for the period 1976-2002 has revealed that Malaysia has maintained low growth and low instability and higher diversification, and Bangladesh and Vietnam have diversified in fish exports. In a country-level comparison, India, Indonesia, Thailand and Philippines have shown moderate growth in production and export of shrimp. The instability associated with their shrimp production has also been moderate. Diversification in fish production as well as exports has been suggested for assured income to farmers and the country. It has been pointed that replacing, supplementing or rotating the shrimp farming with culture of other high-value fish species like Asian sea bass (Lates calcarifer), grouper (Epinephelus spp), mullets (Mugil spp) and milk fish (Chanos spp) culture may ease the risks in mono-cropping of shrimp.Agricultural and Food Policy,

A Study on Services Quality of Commercial Banks in Dire Dawa, Ethiopia: A Comparative Study of Public and Private Banks

This study compares the perception of customers’ about service quality of the public and private commercial banks in Dire Dawa, Ethiopia. This study is a questionnaire survey based on the combined and modified SERVQUAL by Parasuraman et al. (1988) and Banking Service Quality (BSQ) Scale by Bahia and Nantel (2000). It included nine service quality dimensions, with 35 statements, to measure and compare the wide range of services offered by Ethiopian public and private banks. A total of 500 questionnaires were administered and data was collected by stratified random sampling to customers of the two banking sectors and 488 were used for analysis purpose (243 public and 245 private). Comparison was done by using mean of nine dimensions that were used to measure the customers’ perceptions and independent samples t-test was used to explore the differences in the mean values of services quality dimensions between the two groups of customers (public banks’ customers and private banks’ customers). The mean result reveals that private banks outperform public banks in terms of tangibles, reliability, responsiveness, assurance, empathy, effectiveness and price dimensions. Moreover, the result of hypotheses test shows there are significant differences in perception between customers of the Ethiopian public and private banks regarding the responsiveness, assurance, empathy, effectiveness, and price dimensions as indicators of service quality. Keywords: Public Bank, Private Bank, Services quality, Customers’ Perceptions

Screening of yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) genotypes for resistance to Colletotrichum gloeosporoides

Anthracnose is one of the most destructive fungal diseases caused by Colletotrichumgloeosporoides in yard long bean, leading to complete crop loss at all stages and its partslike hypocotyls, stem, peduncle, flowers, leaves and pods were seriously affected. Few bush type cowpea cultivars have been earlier identified as reliable sources of resistance while trailing types are susceptible, but high yielding. Breeding resistant varieties is suggested as the only practical strategy, especially under hot and humid condition. Fifty-yard-long bean genotypes belonging to bush, semi erect and pole types were screened against anthracnose disease through artificial inoculation under pot culture. The present study identified the resistant varieties of vegetable cowpea through artificial inoculation followed by detached leaf assay. Among the 50 varieties of yard long bean observed, Kanakamony, dual purpose yard long bean was found highly resistant with disease severity of 3.67% followed by Arimbra local

FORMULATION DEVELOPMENT, CHARACTERIZATION AND IN- VITRO EVALUATION OF FLOATING MATRIX DOSAGE FORM OF TRAMADOL HYDROCHLORIDE USING VARIOUS POLYMERS

Objective: The purpose of present study was to formulate the gastro retentive floating tablets of tramadol hydrochloride for enhancement of the gastric residence time.Methods: The floating tablets were prepared by direct compression method and evaluated for hardness, thickness, and friability of the tablets. The in vitro drug release studies were performed for different formulations and to optimize the best formulae based on the dissolution profiles.Results: Fourier transform infrared spectroscopy and differential scanning calorimetry studies revealed that there was no interaction between tramodol hydrocholride and excipients. The formulated tablets were evaluated for properties like weight variation, hardness, thickness, friability, drug content, density and floating properties, matrix integrity and complied with USP requirements. The tablets of optimized formula had floating lag time of 120, 72 and 96 seconds and the tablets remained in the floating condition for more than 12 h. The results of drug excipients compatibility studies suggest that there was no significant change in the physical appearance of these blends, when stored at 40 °C/75% RH for a period of 4 weeks.  Among various trial formulations developed with different concentration of polymer F3 (HPMC K4 M with 120mg of polymer), F5 (HPMC K15 M with 100 mg polymer), F11 (PEO WSR 303 with 100mg polymer), were chosen as the optimized formulations based on the release profile.Conclusion: Tramodol HCl floating tablets were successfully made using various polymers for the enhancement of the gastric residence time. From the present study it was concluded that hydroxy propyl methyl cellulose K 4 M can be used as effective polymer for the formulation of floating effervescent tablets of highly soluble drug indicating successful development of sustained release floating drug delivery system.Key words: Tramodol HCl, floating tablets, PEO 303 WSR, PEO N60, HPMC K 4 M, HPMC K15 M and HPMC K 100 M.Â

Performance of parthenocarpic and non-parthenocarpic grafts of cucumber

Effect of rootstock on yield and quality of cucumber scion was studied at Department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during February-May, 2021. Parthenocarpic and non-parthenocarpic cucumber scions were grafted onto five different cultivated cucurbit species i.e. pumpkin, bottle gourd, oriental pickling melon, culinary melon and ash gourd. Significant variations were observed for all the traits under this study. The highest vine length (4.37 m) was observed in Heera scion grafted onto Lagenaria siceraria rootstock followed by Heera scion grafted onto Cucurbita moschata rootstock (4.13 m). The diameter of rootstock hypocotyl was higher in case of KPCH-1 grafted onto bottle gourd (1.48 mm) and Heera grafted onto bottle gourd (1.43 mm). KPCH-1 grafted on bottle gourd (29.33 days) and culinary melon (31 days) rootstocks showed early female flower initiation. The greater number of fruits was observed in graft combination of KPCH- 1 and bottle gourd (32) followed by parthenocarpic grafts with pumpkin (30.33) and ash gourd (30.33) rootstocks. A greater fruit weight was observed in graft combination of Heera and bottle gourd (7.51 kg) followed by Heera grafted onto pumpkin (7.38 kg). Results of this experiment suggest that these graft combinations can be employed in sustainable vegetable cultivation