Himalayan Journal of Science and Technology

Whole genome sequencing (WGS) has become a powerful tool in accessing food-borne infections

Hemanta Khanal — Sun, 31 Dec 2023 00:00:00 +0000

Research Prospective

Utilization of Partially Purified Milk Clotting Protease from Ginger Rhizome in the Manufacturing of Fresh Cheese

Sun, 31 Dec 2023 00:00:00 +0000

This study was carried out to utilize the partially purified ginger rhizome protease in fresh cheesemaking. The crude ginger rhizome extract was partially purified by employing 30-80% (NH4)2SO4 saturations (w/v). The maximum milk clotting activity was achieved at 50% saturation, exhibiting the purification fold of 1.64 and activity recovery of 85.76%. The milk pH and temperature for optimum time of coagulation and milk clotting activity were optimized by using response surface methodology (RSM). A numerical optimization study revealed that the optimum milk pH and temperature for producing cheese were 6.5 and 50 C respectively. The cheese produced by ginger protease had significantly (p<0.05) higher moisture, ash and yield, but lower fat content than the rennet cheese. No significant difference (p>0.05) was found in the calcium and protein content of both cheeses. The prepared cheese using ginger protease had significantly (p<0.05) higher spreadability, but lower aftertaste than the rennet cheese. However, non-significant difference (p>0.05) was observed in the flavor and overall acceptance between the two cheeses. Hence, this study demonstrated that the ginger rhizome protease has the potential to be utilized as an effective milk coagulating enzyme in the manufacturing of fresh cheese.

Adsorption of Hydrogen Molecules in Nickel Decorated Silicene

Prajwal Shrestha, Nurapathi Panth — Sun, 31 Dec 2023 00:00:00 +0000

First-principles simulations based on density functional theory (DFT) have been used to study the structural, electronic and magnetic properties of pristine and Ni decorated silicene sheets. Generalized Gradient Approximation (GGA) based exchange correlation functionals are used under software package Quantum ESPRESSO (QE), 6.5 versions. We have reconstructed the optimized unit cell of silicene, which has a face centered cubic (fcc) structure with two silicon atoms having lattice parameters a = b = 3.8 Å. The distance between two nearest silicene monolayers is found to be 20.5 Å which is large enough to neglect the interlayer interactions between 4×4 supercells of silicene monolayers. The atoms in the prepared supercell are fully relaxed under Bloyden-Fletcher-Goldfarb-Shanno (BFGS) scheme prior to the self-consistent, band structure and density of state (DoS) calculations. The pristine silicene is semi-metallic in nature possessing a Dirac-cone as in graphene. The h-site adsorption is found to be the most stable adsorption site of nickel in silicene with the binding energy of 4.69 eV. The addition of nickel atom completely distorts the hexagonal structure of silicene destroying the Dirac cone and the system becomes slightly insulating from its semi-metallic nature. We then construct a 4×4 nickel dimer silicene which further destroys the hexagonal silicene structure with further opening of the band gap. The charge transfer analysis in the Ni decorated systems shows the charge transfers of 0.163e and 0.294e in Ni adatom silicene and Ni dimer silicene respectively showing that the nickel atoms are adsorbed by weak van der Waals forces in both of the systems. We then proceed to hydrogen molecule adsorption in these prepared 4×4 silicene systems: pristine, Ni adatom and Ni dimer silicene systems. The adsorption energy of hydrogen in the Ni adatom silicene is found to be the largest making it the most effective system for hydrogen storage.

Factors Affecting Academic Achievement of B.Sc. Students of Tribhuvan University Constituent Campuses in Province - 1, Nepal.

Roma Ghimire — Sun, 31 Dec 2023 00:00:00 +0000

An attempt has been made to assess the factors affecting academic achievements of bachelor’s level students under Institute Science and Technology of Tribhuvan University in Province No. 1, Nepal. The academic achievement has been considered as a dependent variable and the gender, caste/ethnicity, socio-economic status and learning facilities as independent variables. A cross-sectional research design was used. The sample size of this research was 130 and the sample was drawn using simple random sampling technique. A well-designed questionnaire was used to collect the data. The Binary logistic regression model was used to find the association of various factors with the academic achievement of the students and the goodness of fit test of the model was assessed through Hosmer and Lemeshow test. The study concluded that the internet facility at libraries, as a learning facility, contributed significantly to the students’ academic achievement whereas the remaining variables had no significant effect on the academic achievement of students’ Moreover, this research also discusses the implications for improving academic achievement.

Comparative Computational Study on Molecular Structure, Electronic and Vibrational Analysis of Vinyl Bromide based on HF and DFT Approach

Sun, 31 Dec 2023 00:00:00 +0000

In this study, we have used the Hartree-Fock and Density Functional Theory method of calculation and compared the equilibrium configuration, electronic and vibrational mode of Vinyl Bromide molecule. The molecule is geometrically optimized initially by using 6-31G basis set with B3LYP functional and then bond angles, bond lengths, dihedral angles and IR spectra are compared respectively. Various groups of atoms in Vinyl Bromide molecule by DFT has more accurate bond length, bond angle values rather than by HF computation when comparing with the experimental values. The ground state energies are found at angle 10° or 180° or 360° using HF and DFT method of calculation for the H4-C1-C2-Br6 position. Values of the carbon-hydrogen, carbon-carbon and carbon-bromine bond lengths and bond angles for optimization state of C₂H₃Br molecule using Hartree-Fock and Density Functional Theory methods with respect to the basis set 6-31G have been analyzed. The C−H in-plane bending vibration and C−H out-of-plane bending vibrations occur in the region 1400–1050 cm^-1 and 1000–675 cm^-1 respectively. The electronic properties, such as Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital energies are performed by HF and DFT approach and the difference in Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital energy gap for HF and DFT method are 14.0847 eV and 6.8994 eV respectively

Characterization, Quality Assessment and Comparison of Selected Rice Landraces (Anadi, Bhotange, and Kalo Nuniya) of Nepal

Sakul Rai, Dambar Bd Khadka, Bimala Pokhrel — Sun, 31 Dec 2023 00:00:00 +0000

This study aimed to characterize, assess and compare the milling-, physical-, cooking-, and eating qualities of brown and milled rice landraces (Kalo Nuniya, Anadi, and Bhotange). Paddysamples (~10 kg each) were cleaned, sun-dried to bring the moisture content to about 13-14%, shelled and then milled to obtain brown (unpolished) rice and milled (white/polished) rice, respectively. Milling-, physical-, cooking-, eating-, and nutritional properties of the rices were studied. The data generated were statistically analyzed using Genstat^®version 12.1 for two-way ANOVA, and MS-Excel version 2019 for the Jarque-Bera test of homogeneity, correlation, and to generate graphical presentations. Bhotangehad better brown rice recovery (BRR=76.70%) and milled rice recovery (MRR=58.91%). Anadiand KaloNuniyahad poorer BRR (71.11%) and MRR (49.97%), respectively. Classifying rice samples based on the ‘grain type’, Anadi-, Bhotange-, and KaloNuniya-white were found to be of Medium-, Long-and Medium-'grain type'. Similarly, Anadi-, Bhotange-,and KaloNuniya-brown were found to be of Medium-, Medium-and Small-'grain type', respectively. In terms of size (1000-kernel weight, TKW), Anadi, Bhotangeand KaloNuniya(all white/polished) were found to be 'Small', 'Small' and 'Tiny'. Equilibrium moisture content during soaking (EMC-S) negatively (moderate degree) correlated with apparent amylose content (AAC) for both milled-(R²=0.73) and brown rices (R²=0.70). In white-rices, apparent water uptake ratio (AWUR) showed moderate degree of positive correlation (R²=0.367) with length/breadth (l/b) ratio. But for brown rices, AWUR showed high degree of positive correlation (R²=0.793) with l/b ratio. Volume expansion ratio (VER) positively (moderate degree) correlated (R²=0.63) with AAC for milled rices. This simple correlation established between 2 parameters (assuming other factors to be the same) with few data points cannot be generalized and further investigations are needed to establish solid correlations. Both Bhotangewhite and Bhotangebrown, respectively, had better cooking properties with lower solid loss (both 1.36 ± 0.11%), cooking times (17.67±1.52 and 25.33±2.51 min), higher VER (2.78±0.03 and 2.70±0.04), and l/b ratios after cooking (3.03±0.03 and 2.59±0.03). Anadiwhite had a sticky texture shown by the least VER (2.63 ± 0.13) and the lowest AAC (15.70±1.03%). Classifying rice samples based on the ‘AAC’, Anadi-, Bhotange-,and KaloNuniya-white had Low-, Low-, and Intermediate AAC. Anadi-, Bhotange-, and KaloNuniya-brown had very Low-, Low-, and Low AAC, respectively. Classifying rice samples based on the GT, Anadi-, Bhotange-, and KaloNuniya-white had Low-, Low-, and Intermediate GT. Similarly, Anadi-, Bhotange-, and KaloNuniya-white had Intermediate-, High-, and High-GT, respectively.

Prevalence of livestock associated methicillin resistant Staphylococcus aureus (La-mrsa) in domestic livestock of Dharan, Nepal

Sun, 31 Dec 2023 00:00:00 +0000

Introduction: Methicillin Resistant Staphylococcus aureus (MRSA) infection has drawn a lot of attention since studies suggested that animals may act as reservoirs for human infection. Over the past 20 years, MRSA infections have become more prevalent worldwide. MRSA was initially only discovered in humans, but later it was discovered in animals as well.

Objectives: The study aimed to determine the prevalence of LA-MRSA in domestic livestock of Dharan, Nepal.

Methods: Overall, 320 skin swab samples of cattle (cows) were collected by swabbing the skin of cattle aseptically with a sterile cotton swab and the samples were transported to the laboratory in a cold chain. The samples were streaked in Mannitol salt agar(MSA) containing oxacillin concentration of 6mg/L and incubated at 37°C for 24 hours. Staphylococcus aureus colonies were identified based on cultural characteristics on MSA plates (golden yellow colonies), Gram’s reaction, and positive results for coagulase and catalase test. The purified isolates of MRSA were subjected to antibiotic susceptibility tests and Biofilm formation.

Results: MRSA was found to be prevalent in 10% of cattle. Antibiotic-resistant tests reported that MRSA was found to be sensitive to chloramphenicol 12(37.5%) followed by ceftriaxone 12 (37.25%), gentamycin 9(28.12%), cefotaxime 4(12.5%), while 100% of MRSA were resistant to penicillin and vancomycin. The moderate biofilm-forming MRSA was 5(15.625%), followed by 3(9.375%) weak biofilm producers and 24(75%) were negative towards biofilm formation.

Conclusion: The prevalence of MRSA (10%) and Vancomycin-Resistant Staphylococcus aureus (100% VRSA) in cattle shows the need for regular surveillance. Chloramphenicol can be a treatment of choice for MRSA infections. However, emerging VRSA is a serious epidemiological issue that needs to be addressed properly. Therefore, Healthcare organizations must adopt precise criteria to control and prevent MRSA infection..

Feasibility study of Replacing Currently used Freons with Ammonium Chloride and Barium Hydroxide for Freezing System

Prithivi Rasaili, Ajaya Bhattarai — Sun, 31 Dec 2023 00:00:00 +0000

The machinery used to cool or freeze food uses a lot of energy. Consequently, it is necessary to lower energy use. Additionally, due to their significant global warming potential (GWP), traditional refrigerants must be replaced to help reduce greenhouse gas (GHG) emissions. Therefore, the usage of alternative refrigerants with lower GWPs is necessary. The possibility of the ammonium chloride (NH₄Cl(s)) and solid hydrated barium hydroxide (Ba(OH)₂.8H₂O(s)) based non-freon refrigerant as a substitute refrigerant was evaluated in this study. Demo-tests were conducted using a prototype refrigerator, which is essentially a closed chamber with foam and PVC insulation. Despite reaching the freezing point satisfactorily, the stirring chamber of the prototype had an unpleasant ammonia odor. Due to the lack of equilibrium between the reactant and product, these components were not permanent solutions like freons. Therefore, further research is needed to determine how effective it would be as a refrigerant

Optimization and Quality Evaluation of Oats (Avena sativa) Flour Incorporated Paneer

Sabin Bahadur Khatri, Kiran Khadka, Navin Gautam, Nabin Khadka, Bicky Raut — Sun, 31 Dec 2023 00:00:00 +0000

Efforts were initiated to prepare a carbohydrate, calcium and fibre rich paneer by addition of oat flour (Avena sativa). Six samples’ formulations were prepare including control paneer, (100% milk curd). The different formulations of (oats flour: milk curd) in the ratio as: sample (1:99), sample (1.5:98.5), sample (2:98), sample (2.5:97.5) and sample (3:97) to access the quality and acceptability of paneer. The experiment was designed by central composite mixture design and the obtained data was analyzed statistically by Genstat Discovery Edition 3 (DE3), for Analysis of Variance (ANOVA) at 5% level of significance version 12.1. The oats flour and milk curd for the development of value-added product, and evaluate proximate and sensory characteristics of product.

The sensory evaluation revealed sample (1:99) was found to be best by comparing sensory score of overall acceptance given by the panelists and functional components. Crude protein, crude fat, total ash and carbohydrate of control product were found to be 41.43%, 49.7%, 4.39% and 4.44% whereas for best product the results were 40.54%, 48.97%, 4.39% and 5.92% respectively. The calcium content of best paneer and control paneer were found to be 467.08 mg/100 g and 399.12 mg/100 g respectively. The fiber contents were zero and 0.156% in control and best product sample (1:99) respectively. Therefore, it was concluded that the incorporation of oats flour for the formulation of value-added paneer will be helpful for developing value-added dairy products for the developing countries.

Phytochemical Screening and Antimicrobial Activity of Piper betle L. and Nicotiana tabacum L. across Dharan, Nepal

Sun, 31 Dec 2023 00:00:00 +0000

Piper betle L. and Nicotiana tabacum L., were studied to find their antibacterial properties. Water, ethanol, methanol, acetone, and petroleum ether were used as solvents for plant crude extraction for phytochemical testings. Total phenolic content and total flavonoid content. Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) were used as test organisms to determine the antibacterial activity of the plant extracts using agar well diffusion method.

This study showed a significant antibacterial activity against both bacterial strains with a zone of inhibition ranging from 7.16 to 17.83 mm for Piper betle L. and 7.16 to 12.5 mm for Nicotiana tabacum L. against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). The study reveals that Nicotiana tabacum L. and Piper betle L. can be a promising source against different pathogenic bacteria if thoroughly explored.

Screening of Antibiotic producing Actinomycetes for Antibiosis from soil of Sunsari, Nepal

Dhiren Subba Limbu, Ramesh Majhi, ShivNandan Sah, Kamana Bantawa, Bishan Rai — Sun, 31 Dec 2023 00:00:00 +0000

Actinomycetes, slow-growing gram-positive bacteria, are useful in the search for bioactive compounds. A total of 24 different actinomycete strains were recovered from farming soil samples collected from the Sunsari district. The isolates were then tested against two gram-positive and three gram-negative bacteria. Results showed that 21% of all isolates are antibacterial at least, one of the test organisms, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella Typhi, and Pseudomonas spp. According to antibacterial activity and spectrum broadness, one of the isolates (S11) was selected for secondary screening. The minimum inhibitory concentration (MIC) of crude antibacterial substances extracted from the broth culture of the isolate (S11) was found to be 1.3 mg/ml against test organisms. The chromatogram in TLC showed only one spot with an Rf value of 0.87 by the isolate suggesting that the isolate produced only one compound which was utterly different from the spot with an Rf value of 0.94 paid by gentamycin. According to identification by Microscopy (1000X) and overall biochemical, and physiological characteristics, the isolate was considered Streptomyces antibioticus, a distinct taxonomic group.

Suitability Analysis of Drinking Water from The Springs of Deumai Watershed Ilam, Nepal

Priya Darshan Shrestha, Manoj Khanal, Champak Babu Shilwal — Thu, 28 Dec 2023 00:00:00 +0000

Spring is one of the major sources of drinking water in hilly and Himalayan region. The overall purpose of this study was to analyse the suitability of drinking water by studying the physicochemical properties. Springs of Deumai watershed Ilam, Nepal was investigated for water samples and the physicochemical parameters studied were TDS, pH, temperature, total hardness, alkalinity, total iron and major ion concentrations (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^–, SO₄^2–, NO₃^–) to describe the water’s chemical characteristics. The physical parameters were determined using pH meter, laboratory thermometer etc. The determination of concentration of chemical parameters was performed by using spectrophotometric method, flame photometric method and titration method. The average pH was found 7.47 and average temperature was found to be 19.4ºC. The dominance trend for major cations was Ca²⁺> Na⁺ > Mg²⁺ > K⁺ > Fe and for anions was HCO₃^– > Cl^– > NO₃^– > SO₄^2–. All the values obtain were within the range specified by WHO and NDWQS guidelines of drinking water. According to the findings and comparison with the guidelines of drinking water given by World Health Organization (WHO) and National Drinking Water Quality Standard (NDWQS), the water quality for drinking water was found within the standards set by them.

Risk Factors Associated with Overweight and Obesity Among Females of Reproductive Age Residing in Damak Municipality

Samiksha Pradhan, Pallavi Vyas Jaisani — Sun, 31 Dec 2023 00:00:00 +0000

The study was intended to assess risk factors associated with overweight and obesity among females residing in Damak municipality. A cross-sectional quantitative study was performed on 202 females of reproductive age (15–49 years) with a structured questionnaire. Measurements like weight, height, and waist and hip circumference were used to determine indicators of overweight and obesity. General obesity was analyzed using the WHO BMI classification, while Waist Circumference (WC) and Waist to Hip Ratio (WHR) analyzed abdominal obesity based on International Diabetes Federation – IDF, and WHO criteria, respectively. Microsoft Office 16 and SPSS Statistics version 20 were used to analyze data. The Chi-square test was used to establish an association between the variables under study.

The study revealed that 31.7% of respondents were overweight, 8.4% were obese, 63.4% were abdominally obese by WC, and 71.8% by WHR. Here, the mean BMI was 25.36±4.56 kg/m2, and the mean WC was 89.69±12.47 cm, with a mean WHR of 0.91±0.09. Age, marital status, family size, parity, sleeping hours, eating pattern, protein intake, and consumption of dairy, eggs, and whole cereals were significantly associated (p<0.05) with overweight and obesity; while age, marital status, education, occupation, family size, parity, and contraceptive use were common factors associated with abdominal obesity (WC and WHR). However, family history, protein intake, and consumption of wheat and eggs were associated (p<0.05) only with WC. The study showed a high prevalence of increased weight among reproductive-aged females in Damak. Thus, being overweight or obese should be viewed as a critical issue. The population should be made aware of the risk factors of obesity.

Length-Weight Relationship of Fishes in Some Rivers of Morang, Nepal

Sharada Shrestha, Ganesh Tamang, Jash Hang Limbu, Dipak Rajbanshi — Sun, 31 Dec 2023 00:00:00 +0000

The length-weight relationship is a crucial aspect of fishery assessments, providing valuable biological information. The length-weight relationship is expressed by the equation W = aL^b, where W represents the total weight of the fish and L denotes the standard length. The LWR equation was transformed into a linear form using logarithmic transformation: LogW = a + bLogL. The biometric data obtained from this study includes information on species, sample numbers (N), standard length range, total weight range, and the length-weight relationship constants (a and b) for each species. In this study, we estimated the length-weight relationship of 16 freshwater fish species from some rivers of Morang district, Eastern Nepal. A total of 1,600 fish specimens, representing 16 different species from 5 families were studied from September 2022 to February 2023. The fishes were captured from the river and preserved in 20% formalin for subsequent biometric measurements in the laboratory. Biometric measurements were taken as follows: for each fish, length measurements were listed as standard length or fork length (SL in cm) from mouth to where the caudal fin is lobate. Length measurements were taken with a regular ruler validated against a Vernier Calliper, with an accuracy of 0.1 cm. Weight measurements were obtained using an electronic digital balance with a precision of 0.01 g. While listing weight, a fish consistency was maintained concerning the degree of wetness of the body to ensure accuracy. Among the species listed in the Morang district, Puntius terio has the smallest range of standard length (2.7 cm - 7.4 cm) and total weight (1.07 g - 7.06 g) while Garra gotyla gotyla has the largest range of standard length (4.3 cm - 18.6 cm) and total weight (4.5 g - 15.6 g). These variations indicate the natural size differences among the species. The analysis of the length-weight relationships revealed that all the studied fish species exhibited a negative allometric growth pattern. This means that as the length of the fish increases, its weight increases at a slower rate. The findings of this study contribute to our understanding of the growth patterns of freshwater fish species in the study area.