Counts In Samples Research Articles

Hygienic Production Practices and Microbiological Quality of Sheep Milk in Ararso District of Jarar Zone, Somali Regional State, Ethiopia

This study was conducted to evaluate the hygienic production practices and microbiological quality of sheep milk in Ararso district of Jarar Zone, Somali Regional State, Ethiopia. A stratified sampling strategy was used to choose 180 households specifically for this investigation. A total of 60 pooled raw sheep milk samples (each containing 200 mL) were collected from the udders and milk handling equipment of selected milk producers in the research area. The samples were examined to determine microbiological quality. The data were gathered via a questionnaire, field observation, key informant interviews, and focus group discussions. The vast majority of respondents in pastoral (86.7%) and agro-pastoral (64.4%) production systems were illiterate. The majority of respondents (70.6%) in the research area cleaned the sheep home (kraal) once every two days. The majority (98.3%) of respondents in the research area milk their sheep in open kraals with no roof or walls. As a consequence, 36.7% of pastoral and agro-pastoral respondents (81.1%) reported cleaning milk vessels on a regular basis. Almost all of the responders in the research area used plastic equipment for milking and handling. The majority of responders in pastoral and agro-pastoralist categories placed barn hygiene first, with indexes of 0.24 and 0.23, respectively. The average total bacterial count (TBC), coiform count (CC) and yeast and mould count (YMC) of raw sheep milk samples were 5.13±0.21, 2.89±0.27, and 0.77±0.21 log10 cfu/mL, respectively. Raw sheep milk samples taken from producers’ milk handling equipment had a substantially higher mean total bacterial count (5.78±0.32 log10 cfu/mL) compared to samples collected from the udder (4.48±0.23 log10 cfu/mL). Milk samples from pastoral and agro-pastoral households had an average coliform count of 3.18 and 2.60 log10 cfu/mL, respectively. The average YMC in milk samples from pastoralists and agro-pastoralists were 0.74 and 0.80 log10 cfu/mL, respectively. In general, pastoralists and agro-pastoralists in the district do not practice hygienic milking and handling. Consequently, the implementation of hygienic milk production and handling practices is essential to enhance the safety and quality of sheep milk in the study area. Additionally, further research should be undertaken to investigate the microbiological aspects and assess the safety and quality parameters of sheep milk in greater detail.

Atmospheric Cold Plasma to Maintain Sea Bass Quality: An Opportunity for International Fish Trade

Whole chilled sea bass is an essential product for the European food market, and Türkiye is the foremost supplier. The importance of sea bass in the world food trade reveals the significance of food safety risks that may arise during or after harvest. This study aimed to examine the impact of atmospheric cold plasma (ACP) on delaying the spoilage of sea bass. The ACP is generated by an original device that produces a dielectric barrier discharge plasma using an alternating current (AC) power supply, applying a 30 kV high voltage with a sinusoidal frequency of 20 kHz. Whole sea bass samples were treated for 1 min (ACP1) or 7 min (ACP7), and then stored at 2 ± 1 °C. Sensory scores of plasma-treated sea bass were higher throughout the storage period. Both treatments decreased the initial bacterial load and delayed bacterial growth (p ≤ 0.05) during storage. The mesophilic aerobic bacteria count of control samples exceeded 6 log CFU/g on the second day of storage. However, ACP1 and ACP7 did not reach this value until the third and fourth days. The control samples had higher TMA-N and TBARS (p ≤ 0.05) than plasma-treated groups. The treatment did not significantly change the texture. Although ΔE was higher in ACP samples, a discoloration that could affect acceptability was not reported during the sensory test. Cold plasma can improve the overall market value by maintaining quality, benefiting the global fish trade. It has been shown that cold plasma has promising potential in the fresh fish industry.

Illumina Sequencing in Conjunction with Propidium Monoazide to Identify Live Bacteria After Antiseptic Treatment in a Complex Oral Biofilm: A Study Using an Ex Vivo Supragingival Biofilm Model

Background/Objectives: The evaluation of the efficacy of antibacterial treatments in complex oral ecosystems is limited by the inability to differentiate live from dead bacteria using omic techniques. The objective of this study was therefore to assess the ability of the combination of the 16S rRNA Illumina sequencing methodology and the action of propidium monoazide (PMA) to study viable bacterial profiles in oral biofilms after exposure to an antiseptic compound. Methods: Cariogenic supragingival biofilms were developed in an ex vivo model for 96 h, using saliva from healthy volunteers. The biofilms were treated with 0.12% chlorhexidine (CHX) combined with 0.05% cetylpyridinium chloride (CPC), for 60 s, using phosphate buffered saline as a control. After exposure, each biofilm was treated or not with PMA to then extract the bacterial DNA, quantify it by Qubit, quantify the bacterial population using qPCR, and perform the metataxonomic study of the samples using Illumina 16S rRNA sequencing. Results: A significantly lower DNA concentration in the PMA-treated biofilms (p < 0.05 compared with those not exposed to PMA) was observed. The viable bacterial count obtained by qPCR differed significantly from the total bacterial count in the biofilm samples exposed to the antiseptic (p < 0.05). The viable microbiome differed significantly from the total bacterial profile of the samples treated with CHX/CPC after exposure to PMA (p < 0.05 at the α- and β-diversity levels). Conclusions: The combination of Illumina 16S rRNA sequencing and PMA helps solve the inability to evaluate the efficacy of antibacterial treatments in the bacterial profile of complex ecosystems such as oral biofilms.

Autoantibody against aquaporin-5 may be a new diagnostic biomarker for primary Sjögren's syndrome.

The study aims to assess the diagnostic and clinical significance of autoantibodies against aquaporin-1 (anti-AQP1) and aquaporin-5 (anti-AQP5) in primary Sjögren's syndrome (pSS). A total of 163 participants were categorized into three groups: pSS group, other connective tissue diseases (CTD) group, and healthy control (HC) group. The levels of anti-AQP1 and anti-AQP5 autoantibodies in serum were determined using enzyme-linked immunosorbent assay (ELISA), and clinical data from patients were collected for statistical analysis. Our results showed that the level of anti-AQP1 in the pSS group was higher than in the HC group (P < 0.05), and no significant difference was observed between the pSS group and the CTD group (P > 0.05). ROC showed that the anti-AQP1 had no diagnostic value for pSS (P > 0.05). The anti-AQP5 level of 39 healthy adults was all below the cut-off value (14.10ng/ml) (P < 0.05). The level of anti-AQP5 in the pSS group was higher than the CTD group (P < 0.05), the AUC was 0.86 (95% CI 0.80-0.93), with a sensitivity of 0.95 (95% CI 0.87-0.99) and a specificity of 0.70 (95% CI 0.58-0.84). No correlation was found between anti-AQP5 levels and the EULAR primary Sjögren's syndrome disease activity index score, anti-SSA, anti-SSB, antinuclear antibodies, rheumatoid factor, anti-ds-DNA, salivary gland flow rate, complement 3, and lymphocyte count in pSS samples (P > 0.05), respectively. Therefore, the elevated anti-AQP5 may emerge as a novel diagnostic biomarker for pSS patients due to high sensitivity and specificity.

Machine learning algorithm approach to complete blood count can be used as early predictor of COVID-19 outcome.

Although the SARS-CoV-2 infection has established risk groups, identifying biomarkers for disease outcomes is still crucial to stratify patient risk and enhance clinical management. Optimal efficacy of COVID-19 antiviral medications relies on early administration within the initial five days of symptoms, assisting high-risk patients in avoiding hospitalization and improving survival chances. The complete blood count can be an efficient and affordable option to find biomarkers that predict the COVID-19 prognosis due to infection-induced alterations in various blood parameters. This study aimed to associate hematological parameters with different COVID-19 clinical forms and utilize them as disease outcome predictors. We performed a complete blood count in blood samples from 297 individuals with COVID-19 from Belo Horizonte, Brazil. Statistical analysis, as well as ROC Curves and machine learning Decision Tree algorithms were used to identify correlations, and their accuracy, between blood parameters and disease severity. In the initial four days of infection, traditional hematological COVID-19 alterations, such as lymphopenia, were not yet apparent. However, the monocyte percentage and granulocyte-to-lymphocyte ratio proved to be reliable predictors for hospitalization, even in cases where patients exhibited mild symptoms that later progressed to hospitalization. Thus, our findings demonstrate that COVID-19 patients with monocyte percentages lower than 7.7% and a granulocyte-to-lymphocyte ratio higher than 8.75 are assigned to the hospitalized group with a precision of 86%. This suggests that these variables can serve as important biomarkers in predicting disease outcomes and could be used to differentiate patients at hospital admission for managing therapeutic interventions, including early antiviral administration. Moreover, they are simple parameters that can be useful in minimally equipped health care units.

Preservation of chicken breast meat by ginger extract and ginger essential oil

The study aims to extend the shelf-life of chicken breast meat by different treatments, including: (i) ratio of ginger: water = 60:40, 70:30 and 80:20; (ii) ginger essential oil 6%, 10% and 14%; (iii) edible coatings formula (sodium alginate combined with ginger extract or ginger essential oil). The research evaluated the effect of these treatments on the physicochemical parameters (pH, color, shear force, drip loss) and microbiological indicators (E. coli and aerobic plate count) of chicken breast meat during the cooling storage. The results showed that the physicochemical parameters of chicken breast meat were not affected by different treatments, these parameters were well maintained during cooling storage (4 &amp;plusmn; 1&amp;deg;C). Moreover, the ginger extract 70%, ginger essential oil 10% and the combination of ginger with an edible coating positively inhibit the growth of microorganisms. The total aerobic and E. coli plate count of samples, which were treated by these treatments, decreased within 7-10 days of cooling storage. Moreover, the chicken breast meat was treated with sodium alginate-ginger essential oil 10% had E. coli and the aerobic microbial plate count was within Vietnamese National Standards (TCVN 12429- 3:2021) during ten days of cooling storage.

Wildlife density estimation by distance sampling: A novel technique with movement compensation.

Estimates of population density are fundamental to wildlife conservation and management. Distance sampling from line transects is a widely used sample count method and is most often analysed using Distance software. However, this method has limited capabilities with mobile populations (e.g., birds), which tend to encounter an observer more often than immobile ones. This paper presents a novel distance sampling method based on a different set of models and assumptions, named WildlifeDensity after its associated software. It is based on mechanistic modelling of visual detections of individuals or groups according to radial distance from the observer or perpendicular distance from the transect line. It also compensates for population-observer relative movement to avoid the detection overestimates associated with highly mobile populations. The models are introduced in detail and then tested in three ways: 1) WildlifeDensity is applied to several 'benchmark' populations of known density and no-to-low mobility, 2) the movement compensation model is tested on two highly mobile songbird populations, and 3) a fairly difficult case is analysed: a low-density, highly mobile bird population in a forest habitat. The results show that 1) using either radial or perpendicular distance data from surveys of immobile populations, WildlifeDensity provides similar estimates (and errors) to Distance, with radial WildlifeDensity analysis appearing to be slightly better for surveys of low-mobility populations (kangaroos), 2) the movement compensation model effectively removes the correlation between observer speed and detection numbers, and 3) WildlifeDensity provides acceptable estimates where conventional Distance analysis overestimates density due to high movement. In summary, WildlifeDensity extends the capabilities of distance sampling by 1) compensating for movement, 2) not requiring complete detectability on the transect line and 3) supporting the use of radial distances, which simplifies fieldwork and increases measurement accuracy.

National recommendations of the Croatian Chamber of Medical Biochemists and Working group for Laboratory hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine: Management of samples with suspected EDTA-induced pseudothrombocytopenia.

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions (i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management (i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions (i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results.

Normalization of short-chain fatty acid concentration by bacterial count of stool samples improves discrimination between eubiotic and dysbiotic gut microbiota caused by Clostridioides difficile infection-

ABSTRACT Short-chain fatty acids (SCFAs) represent a cornerstone of gut health, serving as critical mediators of immune modulation and overall host homeostasis. Patients with dysbiosis caused by Clostridioides difficile infection (CDI) typically exhibit lower SCFAs levels compared to healthy stool donors and, thus, the concentration of SCFAs has been proposed as a proxy marker of a healthy microbiota. However, there is no consistency in the methods used to quantify SCFAs in stool samples and usually, the results are normalized by the weight of the stool samples, which does not address differences in water and fiber content and ignores bacterial counts in the sample (the main component of stool that contributes to the composition of these metabolites in the sample). Here, we show that normalized SCFAs concentrations by the bacterial count improve discrimination between healthy and dysbiotic samples (patients with CDI), particularly when using acetate and propionate levels. After normalization, butyrate is the metabolite that best discriminates eubiotic and dysbiotic samples according to the area under the receiver operating characteristic (ROC) curve (AUC-ROC = 0.860, [95% CI: 0.786–0.934], p < .0001).

A-147 Comparative Precision of Platelet Counting by Optical, Fluorescent, and Impedance Techniques in Thrombocytopenia and Microcytosis Patients

Abstract Background In today's era of automation driven by Artificial Intelligence, even the most efficient automated hematology analyzer may struggle to accurately determine platelet count in patients with low platelet count and microcytosis. The Sysmex XN-series analyzer (Sysmex, Kobe, Japan) uses optical density, fluorescence, and electronic impedance methods for platelet counting. This study aimed to evaluate the accuracy of optical, fluorescence, and electrical impedance methods in estimating precise platelet counts in thrombocytopenic and microcytic patient samples. Methods A cross-sectional study was conducted in the Department of Laboratory Medicine at AIIMS, New Delhi, for 30 days consecutively. A total of 200 blood samples collected, of which 100 samples were of thrombocytopenia (&amp;lt;100x10^9/L) and 100 samples were of microcytosis (Mean corpuscular volume &amp;lt;76 femtoliters). MCV&amp;lt;76 fl was further categorized into 2 groups- MCV 60-70 fl and MCV 71-76 fl accordingly. Males and females were categorized and analyzed distinctly for thrombocytopenia and microcytosis. Statistical analysis was performed using SPSS 16.0 for Windows (SPSS Inc., Chicago, IL, USA) and the Bland Altman plot was analyzed. Results Of the 100 patients with thrombocytopenia (platelet&amp;lt;1 lakh/L) females were predominantly 54% while males were 46% and the median age was 29 years (0.02-70). Of the 100 patients with low MCV (&amp;lt;76 fl) females were 53%, while males were 47% and the median age was 29 years (0.3-69). The findings were compared against the standard manual platelet count method in peripheral smears verified by two expert pathologists. The Bland Altman plot for Platelet &amp;lt;1 lakh/L and MCV &amp;lt;76 fl were compared with standard manual platelet count method and the following findings were obtained i) In female with PLT- &amp;lt;1 lakh/L, PLT-O showed least bias (9.8) followed by PLT-F (10.4) and PLT-I (12.1) ii) In males with PLT-&amp;lt;1 lakh/L, PLT-O showed least bias(14.1) followed by PLT-F(16.5) and PLT-I(17.0) iii) For MCV 61-70fl, PLT-O showed the least bias (4.4) followed by PLT-F (6.7) and PLT-I (28.5) iv)For MCV 71-76fl, PLT-F showed least bias (-0.2) followed by PLT-O (1.5) and PLT-I(31.2). Conclusions Platelet count by optical method (PLT-O) detects platelet count more accurately with minimum bias when compared with PLT-F and PLT-I in patients with thrombocytopenia. In patients with microcytosis, PLT-I is less reliable in comparison to PLT-O and PLT-F. A limitation of the automated hematology analyzer is the inability to detect platelet clumps which is appreciated in peripheral smears.

Nondestructive intelligent detection of total viable count in pork based on miniaturized spectral sensor

Changes in the freshness of pork due to microbial action during complex transportation and storage indicate an urgent need for in-situ, real-time monitoring techniques for chemical spoilage of meat. This study reported the use of a portable detection device based on a miniaturized visible/near-infrared spectrometer, combined with data noise reduction and machine learning methods, to predict the total viable count (TVC) in pork samples. A rapid detection device for pork TVC was designed based on the miniaturized spectrometer; a spectral preprocessing method based on the resolution of the spectrometer was proposed; the effects of different preprocessing methods on the full-wavelength modeling effect were compared; and four different feature wavelength extraction algorithms were utilized for the feature wavelengths of pork TVC. The modeling effects of different simplified models were compared. The results showed that resolution interval correction combined with standard normal variation was the most effective in full-wavelength modeling, with correlation coefficients of prediction set (RP), root mean square errors in prediction set (RMSEP), and relative percent deviation (RPD) of 0.918, 0.464 (lg CFU/g), and 2.508, respectively; interval random frog − partial least squares regression (iRF-PLSR) had the best predictive ability among all simplified models, the number of wavelengths used in the simplified model was reduced by 85.45% compared with the full-wavelength model. In contrast, the model performance was improved with RP, RMSEP, and RPD of 0.948, 0.392 (lg CFU/g) and 2.970, respectively. The combination of a rational spectral acquisition setup and a data processing methodology, the miniaturized spectrometer showed competitive results with the complex detection system in predicting meat TVC.

Innovative probiotic yogurt: Leveraging green banana peel for enhanced quality, functionality, and sensory attributes

Yogurt, a popular dairy product renowned for its nutritional benefits and probiotic content, serves as a functional food with potential health-promoting properties. The objective of this study was to investigate whether incorporating green banana peel polyphenol extract (GBPPE) into yogurt formulations enhances the viability and functionality of probiotics while also potentially improving the overall quality and health-promoting properties of the yogurts. GBPPE was extracted and added to the yogurt formulation at 0.0 %, 0.5 %, 1 %, and 2 %. Various physico-chemical properties of GBPPE as well as a range of physical, biochemical, sensory, and microbial assessments of formulated yogurts were carried out. Compared to the control, yogurt containing GBPPE improves functional characteristics by increasing antioxidant activity while having no detrimental impact on physicochemical and organoleptic properties. In terms of antioxidant capabilities, all fortified yogurts showed significantly (p < 0.05) higher total phenolic, flavonoid contents and antioxidant activities than the control yogurt. The addition of GBPPE also affected (p < 0.05) pH, titratable acidity, viscosity, water-binding capacity, syneresis, and total soluble solids, while no significant differences in the color parameters were detected in both control and all fortified yogurts with reduced brightness (L∗) and increased redness (a∗) of the product. The initial viable counts of all yogurt samples were almost similar, and the maximum and minimum viability loss of probiotics were observed in control and 2 % GBPPE fortified samples, respectively. Sensory assessment revealed that yogurt with 0.5 % banana peel extract outperformed all other treatments except the control. These findings support the sustainable use of GBPPE to create probiotic yogurt with improved physicochemical, microbiological, and sensory qualities.

A spectroscopy-based proof-of-concept (POC) for developing loading of pathogen analyzer (LOPA) for dairy products

Detection of bacterial contamination in dairy products of daily use is a challenge worldwide. We have utilized Methylene Blue Reduction Test (MBRT) for quantification of the microbial count in dairy products (milk) and developed a proof-of-concept (POC) based on this for in-filed applications. In this study, we have used pasteurized milk contaminated with model bacteria Escherichia coli, and Staphylococcus aureus for the calibration and validation of the developed POC. The conversion of MB to Leuco-MB i.e., the colorimetric change due to the reduction of MB to Leuco-MB in presence of microbes has been utilized as the tool to detect presence of microbes in milk. The absorbance peak for methylene blue (MB) at 664 nm decreases significantly in presence of microbes and the blue color becomes faded. In our study, we have employed methylene blue (MB) discolouration phenomenon to estimate the microbial count in milk samples using our developed spectroscopy based POC. The limit of detection (LOD) and the limit of quantitation (LOQ) of the POC were found to be 0.32 CFU/mL and 0.97 CFU/mL. The end users of the developed POC are primarily those involved in the production, processing, testing, regulation, and research of dairy products to ensure they meet safety standards and protect public health. These include retailers, dairy farmers, dairy processors, quality control laboratories, regulatory agencies and research institutions. In our experiment, we have observed a significant change in MB absorption in the milk contaminated with microbes. The indigenously developed sensor strips designed for the working of the POC turn to colorless Leuco-MB compared to milk without the microbes. The analysis of the strips has been measured in the developed device.

Evaluation of the OpTest Fiber Quality Analyzer for Quantifying Cotton and Rayon Microfibers

Microfibers are small fiber particles that separate from larger textiles through wear abrasion or home laundering. Pervasive accumulation of synthetic microfibers in the environment is motivating efforts to quantify them, and to gain a better understanding of the factors that lead to their release from garments. Automated imaging systems have been previously employed for the quantification of synthetic and natural microfibers. In the current study, a rayon standard and microfibers sourced from scoured cotton HVI calibration standards were examined with the Fiber Quality Analyzer-360 (FQA) automated imaging system. Mechanically stirred suspensions of six cotton microfiber standards showed significantly lower fiber counts than those obtained with a rayon standard. Probe sonication of the sample suspensions significantly increased observed fiber counts for the cotton standard samples, by 105% on average. Mean length determinations decreased by, on average, 5% for the sonicated samples, an indication that count increases were not due to sample fragmentation. No significant change was observed for the fiber counts or length measurements of the sonicated rayon samples. The sonicated cotton samples showed an average of 95% detection by the FQA. These results highlight the importance of proper microfiber suspension for accurate detection and quantification using the FQA system.

Threshold of stochastic self-focusing from the Poisson property of extreme-event statistics.

Statistics of self-focusing induced by a stochastic laser driver is shown to converge, in the large-sample-size limit, to a generalized Poisson distribution whose mean is given by the exponent of the respective extreme-value statistics. For a given ratio of the laser peak power to the self-focusing threshold Pcr, the mean number of self-focusing counts in a large sample of laser pulses is shown to depend on the number of pulses in the sample, N, and the signal-to-noise ratio of laser pulses, a. We derive a closed-form solution for the threshold of stochastic self-focusing, which, unlike its deterministic counterpart, Pcr, is a function of the sample size N and the signal-to-noise ratio a. The parameter Na = exp (a2/2) is shown to set a borderline between the deterministic and stochastic regimes of self-focusing. When the number of laser pulses in a sample becomes comparable to Na, self-focusing can no longer be viewed as deterministic even for high signal-to-noise laser beams.

Thermographic assessment of mastitis progression in sahiwal cattle: Insights into the patterns in the natural course of infection

Mastitis is a global concern in the dairy sector, demanding innovative solutions for effective management for quality lifetime milk production. In this study, infrared thermography (IRT) as a non-invasive technology was integrated into routine farm activities for continuous health monitoring of animals. For 30 days, we systematically monitored the udder health status in 40 Sahiwal cows (160 quarters), employing IRT along with the California Mastitis Test (CMT). We also assessed somatic cell count (SCC), microbial identification, and milk quality parameters of representative samples. The thermal imaging data was analyzed, considering both backward propagation from the 0th day to the −10th day and forward propagation from the 0th day to the +10th day. Our findings revealed that on the 0th day, the mean temperatures of the udder surface skin temperature (USST) and teat skin surface temperature (TSST) exhibited differences (p < 0.05) between the quarters affected by sub-clinical mastitis (SCM) and clinical mastitis (CM) in comparison to the healthy quarters, with the highest degree of difference observed. The observed temperature differences between CM and SCM quarters compared to healthy ranged from 1.8 to 3.62 °C and 0.98 to 3.23 °C for USST, and from 1.68 to 3.16 °C and 0.56 to 2.32 °C for TSST, respectively. Furthermore, our observations indicated that both udder and teat quarters responded differently to mastitis. A temperature rise of 1.37 °C in SCM quarters and 1.75 °C in CM quarters was observed between the −10th and -8th day relative to day 0, with the increase being more pronounced in the morning hours. Also, a notable temperature surge occurred during the -2nd and -1st days relative to the 0th day. The log10SCC values and milk quality parameters significantly differed (p < 0.05) between mastitis-affected and healthy samples. In addition, Staphylococcus spp. was identified as the predominant mastitis-causing pathogen in the bacteriological identification conducted in this study. Therefore, IRT efficiently assesses the initiation point of udder infection in Sahiwal cows, aiding in effective udder health management.

Bacterial Inactivation Studies in Shrimp Pond Water by using Different Disinfectant Agents

Abstract Background Aquaculture water plays an important role in the dissemination of antibiotic-resistant bacteria during harvest of shrimps. Mitigation of bacteria through discharge is essential to prevent dissemination downstream. Chemical disinfection of culture water is feasible compared to other methods of bacterial inactivation. Objective To study the effect of different disinfectant agent’s viz., chlorine, Fenton’s reagent, and hydrogen peroxide (H2O2) on inactivation of bacteria from shrimp pond water Methods The water samples were subjected to treatment with various concentrations of chlorine (0.0, 1.0, 2.5, 5.0 and 10.0 mg L−1), Fenton’s reagent (1:10 mM ratio of Fe2+:H2O2; 2:20, 3:30, 4:40, 5:50) and H2O2 (20, 30, 40 and 50 mM) for different time durations (5 min, 15 min, 30 min and 60 min). Results The results indicated that all the disinfecting agents inactivated both the total heterotrophic bacteria and tetracycline-resistant bacteria with increased concentrations and time. At the end of 60 min treatment with chlorination (2.5 mg Cl2 L−1), Fenton’s reagent (2 mM Fe2+ + 20 mM H2O2) and H2O2 (50 mM H2O2), the total heterotrophic bacterial count in the water samples gradually decreased by 2.35, 2.65, and 1.38 log10 CFU mL−1, and tetracycline-resistant bacteria count reduced by 1.57, 1.66, and 1.43 log10 CFU mL−1, respectively from initial bacterial load. Conclusions The study revealed that disinfection agents can be successfully employed in the inactivation of antibiotic-resistant bacteria discharged through aquaculture water. Among three disinfection agents, Fenton’s reagent has been found effective in inhibiting both heterotrophic bacteria and tetracycline-resistant bacteria from water samples. Highlights Bacterial inactivation studies were carried with Chlorination, Fenton’s reagent, and Hydrogen peroxide. The highest decrease in HPC (2.65 log) and tetracycline-resistant bacterial (1.66 log) was noticed in the water samples treated with Fenton’s reagent. The use of disinfection agents effectively mitigates antibiotic-resistant bacteria from aquaculture wastewater.

Nonlinear scenario‐based model predictive control for quadrotors with bidirectional thrust

AbstractThe control of quadrotor vehicles under state and parameter uncertainty is a well studied problem that is vitally important to the deployment of these systems under real world conditions. In this article, we propose a linearization‐based extension to nonlinear systems of the existing scenario model predictive control (MPC) framework, which quantifies the impact of uncertainty on the vehicle dynamics through repeated sampling of the uncertainty space. Given the computational costs of such an approach, we also propose two simplifications of the scenario MPC algorithm that are significantly more tractable. In order to evaluate the performance of the algorithms, the specific problem of the control of a bidirectionally actuated quadrotor vehicle is considered. Simulations are carried out for each scenario MPC scheme as well as for a reference deterministic MPC scheme. When a sufficiently large sample count is considered, each of the scenario MPC algorithms achieves safer performance than the deterministic formulation without sacrificing any optimality. Additionally, the approximate solution techniques conclusively outperform the original nonlinear scenario MPC formulation for the same computational cost.

Assessment of microbial quality of oysters in Negombo Lagoon, Sri Lanka

Oysters are known for their nutritional value as a protein source in the human diet. The present study assessed the microbial quality of the oysters collected from Negombo Lagoon. Oysters and associated water samples were collected from four locations in the lagoon on a monthly basis from October 2021 to August 2022. The salinity, temperature, and pH of each location were also measured in situ. The samples were tested for aerobic plate count (APC), total coliforms, faecal coliforms and Escherichia coli (E. coli) following Sri Lankan Standards (SLS). Statistical analysis was performed using MINITAB 17. The results indicated that the APC in oysters (from 0 to 1.14 x 102 CFU/g) resulted in&lt;5x105 CFU/g, the maximum recommended bacterial count for good quality seafood, while the water showed APC from 1.6 to 1.8 x 103 CFU/mL. The total coliforms and faecal coliform counts in oysters were from 2.67x10-2 to 166×10-2 MPN/g and from 6.67 x 10-2 to 93.3 x 10-2 MPN/g, while these counts in water samples were from13.3 to 366.7 MPN/100mL and from 4.30 to 194 MPN/100 mL respectively. E. coli levels in oysters varied from 1.00 to 81.0 x 10-2 MPN/g, which were below the maximum recommended level (11 MPN/g) for good quality seafood. E. coli levels in water ranged from 1.33 to 93.3 MPN/100 mL. The findings further revealed that the correlations between E.coli in water and water quality parameters were statistically insignificant and weakly positive. But, the correlation between E.coli in oysters and respective water showed a strong positive correlation and it was statistically significant (p&lt;0.05). Although the oysters collected are suitable for direct consumption as per European shellfish harvesting area classification criteria, the microbial counts in water were higher than those of the oysters. Therefore, depuration of oysters is recommended for safe human consumption while continuous monitoring is conducted.

Comparing extragalactic megahertz-peaked spectrum and gigahertz-peaked spectrum sources

Recent sensitive wide-field radio surveys, such as the LOFAR Two-metre Sky Survey (LoTSS), the LOFAR LBA Sky Survey (LoLSS), and the Very Large Array Sky Survey (VLASS), enable the selection of statistically large samples of peaked spectrum (PS) sources. PS sources are radio sources that have a peak in their radio continuum spectrum and are observed to be compact. They are often considered to be the precursors to large radio galaxies. We present a sample of 8032 gigahertz-peaked spectrum (GPS) sources with spectral turnovers near 1400 MHz, and a sample of 506 megahertz-peaked spectrum (MPS) sources with turnovers near 144 MHz. Our GPS sample is over five times larger than any previously known sample of PS sources. These large sample sizes allow us to make a robust comparison between GPS sources and MPS sources, such that we can investigate the differences between these types of sources, and study their lifetimes. The shape of the source counts of both samples match that of the general radio-loud active galactic nuclei (AGN) samples, scaled down by a factor 44 ± 2 for the MPS sample, and a factor 28 ± 1 for the GPS sample. Assuming no cosmological evolution, these offsets imply that both MPS and GPS sources have a shorter duration than general radio-loud AGN, with MPS sources having an ≈1.6 times shorter lifespan than GPS sources. The shorter duration of MPS sources relative to GPS sources can be explained by the transition between GPS and MPS sources coinciding with the jet breakout phase of PS sources, such that GPS sources traverse through the surrounding medium at a lower speed than MPS sources. Such evolution has been observed in simulations of PS source evolution.