Life‐history traits of three Ambassid fishes (Chanda nama,Parambassis lala and Parambassis ranga) from the Mathabhanga River,southwestern Bangladesh

The present study provides the first indication of the life‐history traits, including, population structure, growth pattern, condition factor, form factor (a_3.0), size at first sexual maturity (L_m), natural mortality (M_W) and optimum catchable length (L_opt), of three Ambassid (Chanda nama, Parambassis lala and Parambassis ranga) fishes from the Mathabhanga River in southwest Bangladesh. A total of 370 individuals were occasionally collected from August 2017 to July 2018 with cast nets, gill nets, square lift nets, and conical‐ and box‐traps. The total length (TL) ranged from 2.4 to 7.5 cm for C. nama, 1.9–3.8 cm for P. lala and 1.8–6.5 cm for P. ranga. The length‐frequency distributions (LFDs) showed the 4.0–5.0 cm TL size group for C. nama and the 3.0–4.0 cm TL size group were numerically dominant for P. lala and P. ranga. The length–weight relationships (LWRs) indicated isometric growth for C. nama, and positive allometric growth for P. lala and P. ranga. All the LWR values were very significant (p < .001), with all r² values > .950. Based on the Spearman rank correlation test, body weight (BW) versus Fulton's‐condition factor (K_F) was extremely correlated (p < .001), indicating a better wellbeing for these species. The a_3.0 value was 0.0082, 0.0138 and 0.0104 for C. nama, P. lala and P. ranga, respectively. Based on the maximum length (L_max), the L_m was 4.4 cm TL for C. nama, 2.5 cm TL for P. lala, and 4.0 cm TL for P. ranga. Based on the asymptotic length (L_∞), the L_m was 4.88 cm TL for C. nama, 2.63 cm TL for P. lala, and 4.28 cm TL for P. ranga. The M_W value was 2.2, 3.3 and 2.7/year for C. nama, P. lala and P. ranga, respectively. The optimum catchable length (L_opt) was 5.36 cm TL for C. nama, 2.75 cm TL for P. lala and 4.65 cm TL for P. ranga. The findings of the present study should be very useful for effective and sustainable management of these fishes in the Mathabhanga River and the connecting ecosystems.     

New maximum size record,length–weight relationships and form factor of Hooghly Croaker Panna heterolepis Trewavas, 1977 from the Bay of Bengal (Bangladesh)

The present study analysed the length–weight relationships (LWRs) and form factor (a_3.0) of Panna heterolepis Trewavas, 1977 from the Bay of Bengal, Bangladesh. A total of 316 specimens were sampled during the pre‐monsoon (n = 96), monsoon (n = 116) and post‐monsoon (n = 104) season (March 2018–February 2019) using a Seine bag net. Individual total length (TL) and body weight (BW) were measured with a measuring board and digital weight balance, respectively. The TL vs. BW relationship indicated a negative allometric growth for P. heterolepis. The present study also provides LWR, a_3.0 (0.0070) and a new maximum recorded size (29.50 cm TL and 24.50 cm SL) of P. heterolepis for the first time, data currently lacking in the FishBase online database. The results of the present study will be helpful for stock assessment and management of this fish in the Bay of Bengal, Bangladesh and neighbouring countries.     

Electrochemical reduction of La(Ni3.6Co0.7Al0.4Mn0.3) (LaMM) deuterides investigated by in situ neutron powder diffraction: Following the metal-hydride phase transition under technical operating conditions in a KOD electrolyte

We investigated the first charge cycle of LaNi_3.6Co_0.7Al_0.4Mn_0.3 (LaMM) during electrochemical reduction in a 6N KOD (potassium deuteroxide) electrolyte, corresponding to conditions of commercially used batteries by means of in situ neutron powder diffraction. Our measurement allowed to directly analyze the phase range of the α and β phases and the related volume change as a function of the charge transfer. The intercalation of hydrogen was followed in a home-made electrochemical cell, installed on the high intensity neutron powder diffractometer (DMC) at the Swiss continuous spallation neutron source. Compared to previous investigations following mostly in situ charging under pressure (following pressure–composition–temperature isotherms, PCT), our experimental conditions reflect closely the process as used in technical battery applications.     

Computer-Aided Design of Orally Bioavailable Pyrrolidine Carboxamide Inhibitors of Enoyl-Acyl Carrier Protein Reductase of Mycobacterium tuberculosis with Favorable Pharmacokinetic Profiles

We have carried out a computational structure-based design of new potent pyrrolidine carboxamide (PCAMs) inhibitors of enoyl-acyl carrier protein reductase (InhA) of Mycobacterium tuberculosis (MTb). Three-dimensional (3D) models of InhA-PCAMx complexes were prepared by in situ modification of the crystal structure of InhA-PCAM1 (Protein Data Bank (PDB) entry code: 4U0J), the reference compound of a training set of 20 PCAMs with known experimental inhibitory potencies (IC₅₀^exp). First, we built a gas phase quantitative structure-activity relationships (QSAR) model, linearly correlating the computed enthalpy of the InhA-PCAM complex formation and the IC₅₀^exp. Further, taking into account the solvent effect and loss of inhibitor entropy upon enzyme binding led to a QSAR model with a superior linear correlation between computed Gibbs free energies (ΔΔG_com) of InhA-PCAM complex formation and IC₅₀^exp (pIC₅₀^exp = −0.1552·ΔΔG_com + 5.0448, R² = 0.94), which was further validated with a 3D-QSAR pharmacophore model generation (PH4). Structural information from the models guided us in designing of a virtual combinatorial library (VL) of more than 17 million PCAMs. The VL was adsorption, distribution, metabolism and excretion (ADME) focused and reduced down to 1.6 million drug like orally bioavailable analogues and PH4 in silico screened to identify new potent PCAMs with predicted IC₅₀^pre reaching up to 5 nM. Combining molecular modeling and PH4 in silico screening of the VL resulted in the proposed novel potent antituberculotic agent candidates with favorable pharmacokinetic profiles.     

Estimation of relative growth of Minor carp Labeo bata (Cyprinidae) through multi‐linear dimensions

This study focuses on relative growth through length‐weight relationships (LWRs) and length‐length relationships (LLRs) using a total of 15 linear dimensions of Minor carp Labeo bata (Hamilton, 1822) from the Ganges River, northwestern (NW) Bangladesh. Also, meristic counts covering various fin rays and scales from different body parts (including lateral line scales) of L. bata (Hamilton, 1822) have been studied. A total of 300 individuals of L. bata were sampled occasionally from the Ganges River from July 2013 to June 2014, using various traditional fishing gears (e.g., Cast net, Gill net and Square lift net). Number of fin rays from all fins and scales were counted using magnifying glass. Additionally, a total of 15 different lengths were measured to 0.1 cm and whole body weight (BW) was taken to the nearest 0.1 g for each individual. Fin formula of L. bata is as follows: dorsal, D. 10–12 (i–ii/9‐10); pectoral, P₁. 12–16 (iii–iv/9–12); pelvic, P₂. 9 (i/8); anal, A. 6–7 (ii/4–5); and caudal, C. 20–24 (iv–vi/16–18), respectively. Minimum and maximum lengths were found as 8.0 to 25.1 cm in total length (TL) and body weight (BW) ranges from 4.8 to 161.0 g. All LWRs were highly significant (p < .001) with r² values ≥0.960. Based on r² value, LWR by BW versus TL was the best fitted model among 13 equations. In addition, the LLRs were also significant with r² values ≥ 0.959. According to r² value, LLR by TL versus FL was the best fitted model among 15 equations. This study would be very effective for species identification and stock assessment in the Ganges River, NW Bangladesh and surrounding ecosystems.