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Floristic diversity of Khagrachari Sadar of Khagrachari district, within Chittagong Hill Tracts of Bangladesh, has been investigated. A territory's vegetation type and diversity provide insight into the overall resources, their usage structures, and conservation status that are crucial to developing conservation plans and regulations. This analysis helps to portray the overall scenario of a region's plant biomass/vegetation diversity exquisitely. This study has revealed the occurrence of 369 vascular plant species belonging to 144 genera under 97 families from the study area. Out of these 32 are pteridophytes, 2 are gymnosperms and the rest of 335 are angiosperms. Based on habit distribution, herbs are represented by 150 species followed by shrubs (48), trees (108), climbers (47) and epiphytes by 16 species. Dicotyledonous (Magnoliopsida) group was dominant and represented by 254 species belonging to 73 genera under 62 families, followed by monocotyledonous (Liliopsida) with 81 species under 52 genera and 17 families. Among the dicotyledonous plants, Rubiaceae was found to be the largest family with 24 species, whereas with 17 species Orchidaceae is the largest family in monocotyledonous. It appears that Forested areas are dominated by Melocanna baccifera, with an IVI of 8.00 and have the scanty appearance of two herbs (Spathoglottis plicata, Adiantum flabellaletum) and one tree species (Cycas pectinata). For effective conservation management and sustainable usage of the taxa, the status of occurrence has been determined where 304 species (82.23 percent) are considered as ‘Common’, 61 (16.53 percent) are considered ‘Least Concern’, 2 (0.54%) are considered ‘Vulnerable’ and 2 (0.54%), are considered ‘Critically Endangered’. Several diversity indices, such as Margelef’s richness, Shannon-Winer Index, Pielou’s Evenness, and Simpson’s Index values showed the substantial diversity status of the vascular plant in selected 4 sites. A considerable seasonal fluctuation was evident in the diversity indices at four different research locations where data reflected that the rainy season is more diverse than others.

Medicinal plants play in an important role in the primary health care system. The paper deals with the indigenous knowledge related to ethnomedicinal knowledge and plant parts application for curing various ailments by the ethnic community of Thanchi Upazila of Bandarban Hill District. Semi-structured questionnaires, interviews, group discussions, and specific plant sample collection were done from July 2019 to December 2021 to procure ethno-medicinal data from local herbalists and elderly villagers for this study and from the forest areas. A total of 129 plant species under 110 genera and 63 families have been documented, which have been traditionally used by the ethnic people for the treatment of different ailments. Traditional knowledge and information about medicinal plants such as local names, scientific names, families, habits, habitats, plant-parts used, names of ailments, modes of use, etc. were recorded, validated, and documented. Plant families namely, Asteraceae and Euphorbiaceae were represented by the highest (8) number of species, followed by Fabaceae, Verbenaceae, Apocynaceae, Araceae, Caesalpiniaceae, Lamiaceae, Rubiaceae and Zingiberaceae. The most widely used medicinal plants included Anacardium occidentale, Bombax ceiba, Calotropis gigantea, Terminalia chebula, Aegle mermelos, Ageratum conyzoides, Andrographis paniculata, Aristolochia indica, Blumea balsamifera, Bryophyllum pinnatum, Celosia cristata, Centella asiatica, Melastoma malabathricum, Mimosa pudica, Musa paradisiaca, Oroxylum indicum, Plumbago indica and Vitex negundo. Herbs (36%) were found to be the most used plant, followed by shrubs (33%), trees (17%), climbers (9%) and fern (5%). Most medicinal plants were used for the treatment of fever, skin diseases, cough problems, menstrual problems, body pain, indigestion, headaches, stomachaches, constipation, swelling problems, wounds and others. Among the plant parts, mostly leaves were used (43%), followed by roots (21%), whole plants (10%), stems (6%) along with fruit, rhizome, flower, bark, seed and latex for the treatment of diseases. The most common formulations prescribed to treat various diseases were juices. The findings will be useful for future research in the Bandarban Hill District. Asian J. Med. Biol. Res. 2022, 8 (2), 123-140

The purpose of this study was to estimate the tree biodiversity in the Kaptai National Park. The total area of the Kaptai National Park is about 4,564 ha (11,273.08 acres) under the jurisdiction of Rangamati South Forest Division, Rangamati Hill Tracts district. The study was conducted through extensive survey only on the tree species composition in the Kaptai National Park. During the investigation, a total of 65 tree species belonging to 29 families were recorded from the park. Among the plant families, Mimosaceae possessed the highest number of species (7) followed by Meliaceae (6), Ancardiaceae (5), Moraceae (4), Verbenaceae (4), Combretaceae (4), Myrtaceae (4), Dipterocarpaceae (3), Fabaceae (3), Rubiaceae (2), Bombacaceae (2), Caesalpiniaceae (2), Dilleniaceae (2) and Bignoniaceae (2) respectively. There were 15 families which contained single species. Tree species belonging to the family Mimosaceae was dominated in respect to number of species and their population as well. The findings of the present investigation will contribute in the regeneration of tree species in this degraded forest ecosystem and in the protection, conservation and sustainable management of the Kaptai National Park. Jahangirnagar University J. Biol. Sci. 8(2): 71-79, 2019 (December)

The protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to the current vaccination or natural infection is a global concern. We aimed to investigate the rate of SARS-CoV-2 infection and its clinical features among infection-naïve, infected, vaccinated, and post-infection-vaccinated individuals. A cohort was designed among icddr,b staff registered for COVID-19 testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). Reinfection cases were confirmed by whole-genome sequencing. From 19 March 2020 to 31 March 2021, 1644 (mean age, 38.4 years and 57% male) participants were enrolled; where 1080 (65.7%) were tested negative and added to the negative cohort. The positive cohort included 750 positive patients (564 from baseline and 186 from negative cohort follow-up), of whom 27.6% were hospitalized and 2.5% died. Among hospitalized patients, 45.9% had severe to critical disease and 42.5% required oxygen support. Hypertension and diabetes mellitus were found significantly higher among the hospitalised patients compared to out-patients; risk ratio 1.3 and 1.6 respectively. The risk of infection among positive cohort was 80.2% lower than negative cohort (95% CI 72.6–85.7%; p

Fruits of Sonneratia apetala (Buch.-Ham.) are widely used as food and in treating various diseases in the tropical coastal areas. This study evaluated nutrient compositions in the pericarp and seed of this fruit. Each pericarp and seed was successively fractionated into n-hexane, diethyl ether, chloroform, ethyl acetate, and methanol. Polyphenols contents and antioxidant activities of different pericarp and seed fractions were measured in different in vitro methods and phenolic compounds were determined by HPLC. Carbohydrates, proteins, lipids, and ash contents were 29.6, 8.8, 2.8, and 25.5% of dry weight in pericarp, whereas 28.3, 11.5, 4.2, and 22.7% in seed, respectively. Among the mineral macro-elements, K content was the highest followed by Na, Ca, Mg, P, and S while in micro-elements, Fe was at the largest followed by Mn, Zn, and Cu. The methanol fraction of seed showed the highest polyphenols content (221.9 mg gallic acid equivalent/g fraction), 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 2.1 μg/m...

The reaction of Mn 2 (CO) 6 (pyS) 2 (1) with (CpMo(CO) 3 ) 2 (2) at 110 °C gives the heterodinuclear complex CpMoMn(CO) 3 (μ-CO)(μ-η 2 -pyS))(μ-η 1 -pyS) (3), the mononuclear molybdenum complex CpMo(CO) 2 (μ-η 2 -pyS) (4), and the 46-electron trimolybdenum cluster Cp 3 Mo 3 (μ-CO) 2 (μ-S)(μ 3 -S)(μ-η 2 -NC 5 H 4 ) (5). Compound 4 could also be prepared in high yield from the reaction of 2 with pyridine-2-thiol at 110 °C. Compound 3 represents a rare example of a Mo-Mn heterodinuclear complex containing a μ-η 2 -pyridine-2-thiolato, a μ-η 1 -pyridine-2-thiolato, and a cyclopentadienyl ligand. The 46-electron compound 5 represents a unique example of a trimolybdenum compound containing three cyclopentadienyl ligands, an orthometalated pyridyl ligand, a capping sulfido, a bridging sulfido, and two semibridging CO ligands. Curiously, although this complex is formally electron deficient, it is unreactive toward two-electron donors. The structures of all the compounds have been unambiguously established by single-crystal X-ray crystallography.

The basic aim of this work was to determine the reason for the large variances in sweet potato starch yields during extraction. The study was conducted on 19 varieties of sweet potatoes harvested in both the wet and dry season. There was higher starch content (or decreased water content) in sweet potato harvested in the dry season. There seems to be no direct relationship between starch content and starch recovery. This was because the starch present in the tubers was held in different ways in the fiber. As a result different varieties of sweet potato require different amounts of rasping to release the starch. In the choice of the sweet potato variety for starch extraction the amount of tuber harvested per unit area of land, its starch content (which depends on the season of harvest) and most importantly the starch extractability needs to be taken into account. With increased rasping there was increase in the starch extracted from the sweet potato. However, increased in starch extraction levels a...

The longest common subsequence problem has been widely studied and used to find out the relationship between sequences. In this paper, we study the interleaving relationship between sequences. Given a target sequence T and two merging sequences A and B, we need to find out the LCS between M(A, B) and T, where M(A, B) denotes the merging sequence of A and B. We first present a O((Rr + Pm)log log r) time algorithm where |T| = n, |A| = m, |B| = r, R is the total number of ordered pairs of positions at which the two strings A and T match and P denotes the total number of ordered pairs of positions at which the two strings B and T match. We also propose an algorithm to solve a variation of the problem where block constraint arises. The running time of the blocked version is O(max{Rβ log log r, Pαlog log r}), where α denotes the number of blocks in A and β denotes the number of blocks in B.

Increasing popularity of decentralized Peer-to-Peer (P2P) architecture emphasizes on the need to come across an overlay structure that can provide efficient content discovery mechanism, accommodate high churn rate and adapt to failures in the presence of heterogeneity among the peers. Traditional p2p systems incorporate distributed client-server communication, which finds the peer efficiently that store a desires data item, with minimum delay and reduced overhead. However traditional models are not able to solve the problems relating scalability and high churn rates. Hierarchical model were introduced to provide better fault isolation, effective bandwidth utilization, a superior adaptation to the underlying physical network and a reduction of the lookup path length as additional advantages. It is more efficient and easier to manage than traditional p2p networks. This paper discusses a further step in p2p hierarchy via 3-layers hierarchical model with distributed database architecture in different layer, each of which is connected through its root. The peers are divided into three categories according to their physical stability and strength. They are Ultra Super-peer, Super-peer and Ordinary Peer and we assign these peers to first, second and third level of hierarchy respectively. Peers in a group in lower layer have their own local database which hold as associated super-peer in middle layer and access the database among the peers through user queries. In our 3-layer hierarchical model for DHT algorithms, we used an advanced Chord algorithm with optimized finger table which can remove the redundant entry in the finger table in upper layer that influences the system to reduce the lookup latency. Our research work finally resulted that our model really provides faster search since the network lookup latency is decreased by reducing the number of hops. The peers in such network then can contribute with improve functionality and can perform well in P2P networks.

The starch granules present in the sweet potato roots are imbedded in cellulosic fibers and held together by pcectin substrates. Rasping the chopped roots conventionally does the extraction of starch. Vision of this study was to investigate the effect of endogenous and commercial hydrolytic enzymes (cytolase, pectinase and cellulase) whether breakdown these substrates could lead to better release of the starch granule. The experiments revealed that the inherent or endogenous enzyme had no substantial effect on improving starch extraction. However, the addition of commercial enzyme was found to increase the extraction of starch considerably even at lower levels of rasping. It was found that cytolase enzyme at 0.1% (v/w) level that is a combination of pectinase and carbohydrases was able to enhance starch extraction more than two and half fold than that of control. Besides this mixture of cytolase and pectinase at 0.1% level gave also more than 95% starch recovery. Mixing and optimum temperature for action of the enzymes during incubation increases starch yields. It was found that enzymes addition could serve as a good alternative to increased rasping, which could break down the starch granules and fiber. With the drop in price of the enzymes this could lead to cost saving over the amount spent in rasping. Thus enzyme assisted extraction can perform a major role in getting better yields and quality of starch in an environmentally friendly way.

The starch granules present in the sweet potato roots are imbedded in cellulosic fibers and held together by pectin substrates. Rasping the chopped roots conventionally does the extraction of starch. Vision of this study was to investigate the effect of endogenous and commercial hydrolytic enzymes (cytolase, pectinase and cellulase) whether breakdown these substrates could lead to better release of the starch granule. The experiments revealed that the inherent or endogenous enzyme had no substantial effect on improving starch extraction. However, the addition of commercial enzyme was found to increase the extraction of starch considerably even at lower levels of rasping. It was found that cytolase enzyme at 0.2% (v/w) level that is a combination of pectinase and carbohydrases was able to enhance starch extraction more than two and half fold than that of control. Besides this, mixture of cytolase and pectinase at 0.1% level gave also more than 95% starch recovery. Mixing and optimum temperature for action of the enzymes during incubation increases starch yields. It was found that enzymes addition could serve as a good alternative to increased rasping, which could break down the fiber to get out the starch granule. With the drop in price of the enzymes this could lead to cost saving over the amount spent in rasping. Thus enzyme-assisted extraction can perform a major role in getting better yields and quality of starch in an environmentally friendly way.