Reproductive biology of Lepidocephalichthys guntea: a key conservation approach considering environmental factors in Payra River, Bangladesh.

The guntea loach, Lepidocephalichthys guntea, is categorically common freshwater fish in Southeast Asia. Current study is the first elucidation on the reproductive feature of L. guntea including population structure, sex ratio (SR), size at first maturity (Lm), breeding period, and condition factor, emphasizing on the effect of environmental factors on reproduction of this fish in the Payra River (Southern Bangladesh) during July 2021 to June 2022. Using various conventional gears, 1128 individuals (534 males and 594 females) have been collected. Total length (TL), standard length (SL), and body weight (BW) of each fish were measured. Ovaries were cautiously dissected, removed, and precisely weighed. TL ranges from 4.6 to 9.7 cm (BW = 0.7-9.27 g) for male and 4.6-10.3 cm (BW = 0.8-10.75 g) for female. Both male (47.34%) and female (52.66%) populations were the leading group in 7.00-7.99 cm TL. Overall SR was not notably altered from anticipated value of 1:1 (male:female = 1:1.11). Nonetheless, monthly variations of SR specified females were considerably outnumbered males in each month excluding March-May. Lm range was 6.4-7.0 cm, so larger than Lm is recommended to exploit. Monthly changes in GSI indicated that the main spawning season was from March to June. The spawning season was substantially correlated with rainfall, nonetheless with temperature. Additionally, relative weight indicated that habitat was imbalanced with higher predators. A fishing ban is recommended during peak spawning to protect L. guntea in the Payra River and its surroundings based on current research.

Computational study for temperature distribution in ArF excimer laser corneal refractive surgeries using different beam delivery techniques.

Refractive errors are the most common causes of vision impairment worldwide and laser refractive surgery is one of the most frequently performed ocular surgeries. Clinical studies have reported that approximately 10.5% of patients need an additional procedure after the surgery. The major complications of laser surgery are over/under correction and dry eye. An increase in temperature may be a cause for these complications. The purpose of this study was to estimate the increase in temperature during laser refractive surgery and its relationship with the complications observed for different surgical techniques. In this paper, a finite element model was applied to investigate the temperature distribution of the cornea when subjected to ArF excimer laser at a single spot using various beam delivery systems (broad beam, scanning slit, and flying spot). The Pennes bio-heat equation was used to predict the temperature values at different laser pulse energies and frequencies. The maximum temperature increase by ArF laser ([Formula: see text] frequency and [Formula: see text] pulse energy) at a single spot was [Formula: see text] for [Formula: see text] diopter correction ([Formula: see text] of ablation of corneal stroma) using broad beam, scanning slit, and flying spot beam delivery approaches respectively. The peak temperature due to a single pulse was estimated to be [Formula: see text]. Although the peak temperature (sufficient energy to break intermolecular bonds) exists for a very short time ([Formula: see text]) compared to the thermal relaxation time ([Formula: see text]), there is some thermal energy exchange between corneal tissues during a laser refractive surgery. Heating may cause collagen denaturation, collagen shrinkage, and more evaporation and hence proposed to be a risk factor for over/under correction and dry eye.

Scaling in Colloidal and Biological Networks.

Scaling and dimensional analysis is applied to networks that describe various physical systems. Some of these networks possess fractal, scale-free, and small-world properties. The amount of information contained in a network is found by calculating its Shannon entropy. First, we consider networks arising from granular and colloidal systems (small colloidal and droplet clusters) due to pairwise interaction between the particles. Many networks found in colloidal science possess self-organizing properties due to the effect of percolation and/or self-organized criticality. Then, we discuss the allometric laws in branching vascular networks, artificial neural networks, cortical neural networks, as well as immune networks, which serve as a source of inspiration for both surface engineering and information technology. Scaling relationships in complex networks of neurons, which are organized in the neocortex in a hierarchical manner, suggest that the characteristic time constant is independent of brain size when interspecies comparison is conducted. The information content, scaling, dimensional, and topological properties of these networks are discussed.

River pattern influences the composition of small indigenous species (SIS) of fish in deltaic Rajbari district, Bangladesh.

Bangladesh is endowed with diverse rivers providing huge ecosystem services, but the diversity status and the abundance of the small indigenous species (SIS) are not identical in all rivers due to the natural water flow regime and anthropogenic challenges. Therefore, the present study endeavors to elucidate the composition and conservation status of SIS fish from four rivers namely, the Padma, the Gorai, the Chandana and the Horai rivers of Rajbari District, Bangladesh. Data were meticulously collected through fish sampling in each season, field observations, focus group discussions, and individual interviews by using a semi-structured questionnaire spanning from May 2021 and April 2022. The number of SIS in the Padma, the Gorai, the Chandana and the Horai rivers of Rajbari were 60, 36, 33 and 26, respectively, whereas a predominant concentration of fishes was notably observed in the benthopelagic zone of these rivers. Among the 60 riverine SIS, 23 fish were common in the four rivers. Additionally, Cyprinidae (>30%) was observed to be the most abundant SIS in the studied rivers. The fishermen in the research area used seven major fishing equipment of which cast nets are the most common for catching fish species. The abundance of SIS during the rainy season was the highest for all the studied rivers than the other seasons and 12 SIS were available throughout the year. Notably, the least concerned SIS outnumbered the other categories whereas, more than 10% was under the vulnerable category in the four rivers. The leading threats to the fish diversity were pollution followed by illegal and overfishing, siltation, reduced depth, degeneration of rivers and others. Consequently, to safeguard the existing SIS, reducing human pressure, implementing fishing regulations strictly, establishing and administering fish sanctuaries, and raising public awareness can be helpful for the sustainability of aquatic resources in deltaic areas.

Evaluating biometric indices for Indian Gagata, Gagata cenia (Hamilton, 1822) through multi-model inferences.

Biometric indices provide crucial information on fish population growth and aquatic habitat well-being. This study offers the first comprehensive elucidation on biometric indices of Gagata cenia (Hamilton, 1822) specifically; population structure, growth pattern and parameters, form factor (a 3.0 ), conditions factors, prey-predator status, reproduction, optimum catchable length (L opt ), mortality and exploitation rate in the Jamuna River, northern Bangladesh. The aim of this study is to estimate stock status of G. cenia in order to protect the declining wild stock. Total of 725 fishes were randomly collected (ranges between 2.7 and 8.5 cm total length (TL), while 0.30-8.24 g body weight (BW)) occasionally using conventional fishing gears during June 2020 to May 2021. The b value of length-weight relationship (TL vs. BW) was 3.33 which indicated positive allometric growth pattern with r 2 value 0.942. Growth parameters were supposed as asymptotic length (L ∞ ) = 9.09 cm, (K) = 0.94 year-1, growth performance index (Ø') = 1.89 and longevity (t max ) = 3.2 year-1 for this population. The calculated a 3.0 was 0.0172 and Fulton's condition (K F ) is the best suited tool for assessing the well-being of this population. Additionally, relative weight (W R ) specifies an imbalanced territory with regard to the occurrence of predators. The size at sexual maturity (L m ) and L opt for combined sexes of G. cenia were 5.4 cm and 6.0 cm, respectively henceforth fish sizes 6.0-6.5 cm TL are recommended for exploitation. The current study verified fishing mortality was significantly lower than natural mortality and the exploitation rate (E) was 0.32 which indicated the stock was under fishing. Our findings would be very beneficial in planning the sustainable and appropriate management of this fish in Bangladesh and nearby ecosystems.

Fish availability and market channel in Rajbari, Bangladesh.

Knowledge about fisheries market margins and fish availability in the market is crucial to establish an effective and well-planned marketing strategy. Hereby, the study was conducted to bring some knowledge on the availability of raw and processed fish and its marketing channel in Rajbari Sadar, Bangladesh from June to December 2020. Here, data were collected from fish traders and consumers of the target markets through questionnaire surveys, focus group discussions and field visits. The study found 107 fish and shellfish species in these markets, of which more than 50% species were commonly available and less than 10% were found very rarely. The study also observed 18 types of processed fish products in these markets including dried (77.77%), salted (16.67%) and fermented (5.56%) products arriving from mostly Dhaka and Chattogram. The markets were dominated by wild freshwater fishes of nearby rivers, ponds and canals etc. The length of processed and marine fish marketing channel was comparatively longer than freshwater one because these items are supplied here from coastal districts via several intermediaries. The study revealed remarkable market margin for hilsa fish even noticed up to 57.14% at consumer level. There was also observed some major constraints to a good marketing system such as unplanned market location, insufficient drainage system, high transportation cost, etc. Based on the constraints, the study would suggest to establish a well-planned and modern equipped fish market with high quality cold storage and ice factories, which could help to ensure smoother transaction route from production to customer minimizing economic loss.

Entropy generation in MHD Casson fluid flow with variable heat conductance and thermal conductivity over non-linear bi-directional stretching surface.

This consideration highlights the belongings of momentum, entropy generation, species and thermal dissemination on boundary layer flow (BLF) of Casson liquid over a linearly elongating surface considering radiation and Joule heating effects significant. Transportation of thermal and species are offered by using the temperature-dependent models of thermal conductivity and mass diffusion coefficient. Arising problem appear in the form of nonlinear partial differential equations (NPDEs) against the conservation laws of mass, momentum, thermal and species transportation. Appropriate renovation transfigures the demonstrated problem into ordinary differential equations. Numerical solutions of renovated boundary layer ordinary differential equations (ODEs) are attained by a proficient and reliable technique namely optimal homotopy analysis method (OHAM). A graphical and tabular interpretation is given for convergence of analytic solutions through error table and flow behavior of convoluted physical parameters on calculated solutions are presented and explicated in this examination. Reliability and effectiveness of the anticipated algorithm is established by comparing the results of present contemplation as a limiting case of available work, and it is found to be in excellent settlement. Decline in fluid velocity and enhancement in thermal and species transportation is recorded against the fluctuating values of Hartman number. Also reverse comportment of Prandtl number and radiation parameter is portrayed. Moreover, it is conveyed that supplementing values of the magnetic parameter condenses the fluid velocity and upsurges the thermal and concentration distributions. Negative impact of elevating Joule heating phenomenon is noted on the molecular stability of the system via Brinkman number [Formula: see text] Furthermore, the system's stability at a molecular level is controlled by diminishing values of radiation [Formula: see text] temperature difference [Formula: see text] concentration difference [Formula: see text] diffusion parameters [Formula: see text] and Brinkman number [Formula: see text].

Hopf bifurcation and global dynamics of time delayed Dengue model.

BACKGROUND AND OBJECTIVE: Dengue viral infections are a standout amongst the supreme critical mosquito-borne illnesses nowadays. They create problems like dengue fever (DF), dengue stun disorder (DSS) and dengue hemorrhagic fever (DHF). Lately, the frequency of DHF has expanded considerably. Dengue may be caused by one of serotypes DEN-1 to DEN-4. For the most part, septicity with one serotype presents upcoming defensive resistance against that specific serotype yet not against different serotypes. When anyone is infected for a second time with different serotypes, a serious ailment will occur. The proposed model focused on the dynamic interaction between susceptible cells and free virus cells. The ailment free steady states of the specimen are determined. The steadiness of the steady states has been examined by using Laplace transform. METHODS: We introduce an appropriate numerical technique based on an Adams Bash-forth Moulton method for non-integer order delay differential equations. The numerical simulations validate the accuracy and efficacy of the numerical method. RESULTS: In this paper, we study a non-integer order model with temporal delay to elaborate the dynamics of Dengue internal transmission dynamics. The temporal delay is presented in the susceptible cell and free virus cell. Centered on non-integer Laplace transform, some environs on firmness and Hopf bifurcation are derived for the model. Beside these global stability analysis is also done. Lastly, the imitative theoretical results are justified by few numerical simulations. CONCLUSION: The study spectacles that the non-integer order with temporal-delay can successfully enhance the dynamics and rejuvenate the steadiness terms of non-integer order septicity prototypes. Both the ailment free equilibrium (AFE) node and ailment persistent equilibrium (APE) node are steady for the given system. We deduce a recipe that regulates the critical value at threshold.