Some of the properties of polygalacturonase preparations from commercial fungal preparations have been reported in recent investigations (3, 4,5, 7 ) . The results of older investigations ( 4 ) on pH optima, stability, and activation by alkali salts are subject to errors arising from the use of ill-dehed substrates and of preparations containing pectin esterase (PE ) as well as pectin polygalacturonase (PG) . The effect of several factors on the activity of purified PG prepared from three commercial fungal sources is presented here j the investigations in more detail have been reported by Rahman (11).EXPERIMENTAL Source and purification of polygalacturonases. Diluent-free pectinase preparations a were used in this study. These were purified by the methods described by Lineweaver et at. (6). The PG from Pectinol 45AP was obtained by adsorption on alginic acid, elution with NaCl a t 5°C. followed by acid inactivation of PE, and had an activity of 3.6 X 10" PG units per mg. total nitrogen. The PG from Pectinol 46AP and Wallerstein pectinase, since they were both found to be o n l y slightly adsorbed by alginic acid, were purified by acid treatment followed by ammonium sulfate and lead acetate fractionation. Their P G activities in similar units were 0.8 and 1.2, respectively.Pectic acid preparations. Two preparations of pectic acid were used in this study, one was the Wichmann pectic acid prepared from Sunkist Growers Exchange pectin N F as described by Newbold (9) and Newbold and Joslyn (lo), the other was pectic acid prepared from the Sunkist Growers Exchange sodium ammonium pectate by the procedure described by Joslyn et al. ( 2 ) . The analysis of the original pectin and of the pectic acid preparations using the methods described previously (10) are shown in Table 1.
Cybercrime becomes costlier than physical crime in developed economies. As a result, it has become the top priority in governance issues in financial institutions. As a developing nation in Bangladesh, the banking sector faces multi-dimensional challenges to adopt IT applications in banking with cybercrime. The paper examines what the banking industry faces cyber security risks and how the board members contribute to identify and mitigate the risk. Through an in-depth interview among the directors of commercial banks in Bangladesh, we identified the possible cyber risk and prepared the risk profile describing the sources, implications, severity of impact, likelihood of occurrence and ranked them. The result shows that the IT governance risk, IT investment risk, and information risk are most critical among the significant cyber security risks. The results of the study have important implications for both corporate boards and policymakers.
Although the enzymatic hydrolysis of pectic substances has been under investigation for a considerable time, and some aspects of its mechanism are known, the nature of this hydrolysis is not yet fully elucidated (7,9). Most of the data on the hydrolysis of 1,4glycosidic bonds of polygalacturonic acid preparations have been obtained with crude or at most partially purified polygalacturonases from commercial fungal enzymes. Jansen and MacDonnell ( 4 ) showed that polygalacturonase ( P G ) obtained from Pectinola preparations and free from pectin esterase ( P E ) will hydrolyze pectic acid rapidly, but its rate of hydrolysis of pectinic acids of varying degree of esterification with methyl alcohol decreases with increase in esterification. They explain the differences in rate of hydrolysis and in extent of hydrolysis by postulating that both the carbonyl groups adjacent to a 1,4-linkage must be free for it to be labile to PG. Matus (Zl), however, reported extensive glycosidic splitting of highly esterified pectic acids by crude PG preparations obtained from Swiss commercial filtration enzyme preparations. The hydrolysis of pectic acid by PG preparations from Pectinols has been followed usually by determination of decrease in viscosity and increase in free aldehyde groups ; these preparations are characterized by extensive decrease in viscosity (of the order of magnitude of 50%) when the extent of hydrolysis as measured by increase in reducing power is 2% or slightly less (4,7,9,10). Hydrolysis apparently occurs by random scission of the glycosidic linkages of pectic acid leading to the accumulation of D -galacturonic acid. By the application of chromatographic methods, compounds intermediate between pectic acid and D-galacturonic acid have been detected during the course of hydrolysis of pectic acid by PG preparations from three different molds ( 6 ) , and also of pectinic acid by commercial pectic enzyme preparations (16). The formation of lower molecular weight products of hydrolysis has been demonstrated, also by the use of ion exchange resins ( 3 ) . The polygalacturonase of Neurospora Grassa has been recently shown to convert more than 50% of the pectic acid hydrolyzed to a low molecular weight polyuronide (M W ca. 4,000), (18) ; di-and tri-galacturonic acids have been isolated among the end products of hydrolysis of pectic acid by the polygalacturonase of Saccharomyces fragilis (13) and also by a commercial fungal preparation (1). Fungal preparations thus may differ in their content of PE, and contain more than one PG enzyme (pectin depolymerase as well as pectin polygalacturonase).Since but little information was available in 1948 at the start of our investigations (14) on the course of hydrolysis of well defined pectic acid "Commercial pectic enzyme preparations manufactured by Rohm and Haas Company, Philadelphia, Pennsylvania. 308
Background Smokeless tobacco (SLT) use in Bangladesh is one of the highest in the world. Despite having a tobacco control programme, the use of SLTs has increased in recent years. The objective of this paper is to report on the prevalence of SLTs and challenges faced during control measures in Bangladesh. Methods A wide range of published reports on tobacco in general and SLT were reviewed. Websites of relevant organizations and national survey reports including PubMed were visited to identify national‐ or subnational‐level data. Legislations, policies and their implementation and programmes are reviewed. Additional data were captured by active surveys on SLT products, especially on graphic health warning. The authors’ perspectives on SLT control in Bangladesh were captured through a series of brainstorming sessions. Findings The reported prevalence of SLTs ranged from 21% to 26% among adults. SLT control measures are not adequately addressed despite the existence of several policies and programmes. It is based to the definition of Tobacco Control ACT in 2013. We propose inadequate prioritization and weak policy directives; unregulated industry leading to high production, marketing, violation of package warning and tax evasion; high level of cultural acceptance; and poor awareness of the people as challenges to the control efforts. In addition, a lenient attitude of the government towards the so‐called “cottage” industry made SLTs unabated. We propose prioritization of SLT control, strengthening industry monitoring and tax measures, countering cultural acceptability and public ignorance and cessation support engaging government and civil society organizations as the way forward. Conclusion The control measures should be evidence‐based warranting operational research. Government and non‐government organizations’ collaborative efforts on an immediate, short‐and long‐term basis are recommended to meet the challenges of SLTs. These primarily include policy support for prioritization, enforcement of legislation, industry and marketing regulation, stringent tax measures, denormalizing societal acceptability and cessation support.
An increase in using mobile phones and the availability of many phone brands induced the customers to consider various preferences in purchasing decisions. This descriptive study aimed to determine the factors that affect customers' preferences to buy a cellular phone. The primary data was collected from a survey among the smartphone users in different age groups through a structured questionnaire. The study results show that more than 70 percent of smartphone users belong to the age group under 40 years. The study found that, among the factors examined, product features, brand image, price, and product quality are the most significant factors influencing the Bangladeshi customers to buy smartphones. The study's findings have critical implications to mobile phone manufacturers to achieve competitive advantages in the market.
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