The first Holocene stratigraphic record of river-channel occupation and switching between the Brahmaputra-Jamuna and Old Brahmaputra paleovalleys is presented here. Motivated by the Brahmaputra River's historic avulsion from the Old Brahmaputra channel to its present-day Jamuna course, we have obtained sediment and radiocarbon samples from 41 boreholes along a 120 km transect crossing these two braided-river valleys. The stratigraphy along this transect reveals sand-dominated Holocene channel systems, each bound by remnant, mud-capped Pleistocene stratigraphy. Using sediment lithology and bulk strontium concentration as a provenance indicator, we define the geometry and channel-occupation history of each paleovalley. The western Brahmaputra-Jamuna valley is broad and somewhat deeper compared with the Old Brahmaputra valley, the latter actually comprising a composite of two narrower sub-valleys bifurcated by an antecedent topographic remnant. The gently sloped valley margins (slope: 0.002 to 0.007) and high width-to-thickness ratio (W/T:~1000) of the Brahmaputra-Jamuna valley suggest that it was filled primarily through lateral channel migration and the reworking of braidbelt and overbank deposits. Conversely, the two Old Brahmaputra sub-valleys have comparatively steeper valley margins (slope: 0.007 to 0.022) and lower width-to-thickness ratios (W/T:~125 and 250), indicating that these were filled primarily through vertical aggradation of channel sands. We attribute this disparity in valley geometry and fill processes to the different occupation histories for each valley. In this case, the much larger Brahmaputra-Jamuna valley represents the principal, if not singular, river course during the last lowstand of sea-level, with a prominent gravel lag underlying the valley. In contrast the smaller Old Brahmaputra valleys do not appear to have been present, or at least well developed, at the last lowstand. Rather these courses were first occupied during the early Holocene transgression, and we infer that the river had been previously excluded from this region by the relatively higher elevation between the Madhupur Terrace and the Shillong Massif. We also demonstrate that the Brahmaputra River experienced 3-4 major avulsions during the Holocene, with considerably longer occupation times within the principal Brahmaputra-Jamuna valley. Together these observations indicate that occupation history and antecedent topography have been important controls on river course mobility and avulsion behavior.

The microbiota of the nasopharyngeal tract (NT) play a role in host immunity against respiratory infectious diseases. However, scant information is available on interactions of SARS-CoV-2 with the nasopharyngeal microbiome. This study characterizes the effects of SARS-CoV-2 infection on human nasopharyngeal microbiomes and their relevant metabolic functions. Twenty-two (n = 22) nasopharyngeal swab samples (including COVID-19 patients = 8, recovered humans = 7, and healthy people = 7) were collected, and underwent to RNAseq-based metagenomic investigation. Our RNAseq data mapped to 2281 bacterial species (including 1477, 919 and 676 in healthy, COVID-19 and recovered metagenomes, respectively) indicating a distinct microbiome dysbiosis. The COVID-19 and recovered samples included 67% and 77% opportunistic bacterial species, respectively compared to healthy controls. Notably, 79% commensal bacterial species found in healthy controls were not detected in COVID-19 and recovered people. Similar dysbiosis was also found in viral and archaeal fraction of the nasopharyngeal microbiomes. We also detected several altered metabolic pathways and functional genes in the progression and pathophysiology of COVID-19. The nasopharyngeal microbiome dysbiosis and their genomic features determined by our RNAseq analyses shed light on early interactions of SARS-CoV-2 with the nasopharyngeal resident microbiota that might be helpful for developing microbiome-based diagnostics and therapeutics for this novel pandemic disease.

BackgroundCiprofloxacin is a broad-spectrum antibiotic that acts against a number of bacterial infections. The study was carried out to examine the in vitro quality control tests for ten leading brands of ciprofloxacin hydrochloride 500 mg tablet formulation, registered in Bangladesh by Directorate General of Drug Administration. The quality control parameters of ten different brands of ciprofloxacin hydrochloride 500 mg tablets were determined by weight variation, friability, hardness, disintegration, dissolution and assay tests. All the tablets were evaluated for conformity with United States Pharmacopoeia-National Formulary (USP-NF) and British Pharmacopoeia (BP) standards.ResultsAmong ten brands of tablets Brand C had lower mean weight variation of 1.59% and Brand E had highest mean weight variation of 3.32%. For friability test Brand F had lowest mean friability (0.27%) and Brand G had highest mean friability (0.54%). Among ten brands mean lowest and highest hardness were founded in Brand G (4.49 kg/cm2) and Brand F (7.13 kg/cm2) respectively. The disintegration time for ten brands of ciprofloxacin tablet obtained were in the subsequent order: Brand G (8.19 min) < Brand C (9.25 min) < Brand E (9.61 min) < Brand D (10.11 min) < Brand B (11.07 min) < Brand A (12.15 min) < Brand H (13.68 min) < Brand I (14.59 min) < Brand J (16.32 min) < Brand F (17.49 min). Among ten brands for dissolution test mean percentages of drug release were not less than 80% in 45 min for four tablets (Brand E, 81.52%; Brand D, 86.44%; Brand G, 86.82% and Brand C, 94.12%), consequently they met BP standard and as per USP-NF standard six brands (Brand B, 75.62%; Brand A, 76.18%; Brand E, 81.52%; Brand D, 86.44%; Brand G, 86.82% and Brand C, 94.12%) had released not less than 75% drugs, so they also complied with the standard. The percentages of the drug content of the ten brands of ciprofloxacin tablet were obtained in the following sequence: Brand H (96.84%) < Brand J (97.34%) < Brand D (98.15%) < Brand I (98.47%) < Brand E (99.37%) < Brand F (100.28%) < Brand B (100.38%) < Brand A (100.54%) < Brand G (101.39%) < Brand C (101.46%). All of the brands met the BP and USP-NF specifications for assay. First-order, Higuchi and Korsmeyer–Peppas kinetics model fit for all of the mentioned ten brands.ConclusionThe present study revealed that all of the leading brands of this tablet met the quality control parameters as per pharmacopoeial specifications except dissolution test for four brands (Brand J, Brand H, Brand I, and Brand F).

Nature is the best source of complementary and alternative medicine. The plant Phyllanthus acidus (PA) L. has been used traditionally in pain, inflammatory and oxidative stress related disorders. In this consequence, methanolic extract of PA (MEPA) was selected to explore the ability of this plant to enhance cognitive function, brain antioxidant enzymes and anti-acetylcholinesterase activity which can be used for the treatment of oxidative stress related disorders like Alzheimer's disease (AD). The purpose of this study was to investigate the neuroprotective effect of MEPA on learning and memory impairment in scopolamine-induced rats of dementia and oxidative stress. Treatment with MEPA (i.e., 100 and 200 mg/kg b.w.) was investigated in scopolamine-treated Swiss albino male rats for 14 days and its neuroprotective effects were examined using Elevated Plus Maze (EPM) test, Passive Avoidance (PA) test, Novel Object Recognition (NOR) test, Morris Water Maze (MWM) test as well as level of antioxidant enzymes such as catalase (CAT), super oxide dismutase (SOD), glutathione reductase (GSR), glutathione-S-transferase (GST), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), lipid peroxidation (TBARS) contents and * Corresponding author. Md. S. Uddin et al. 54 acetylcholinesterase (AChE) activity in rat brain tissue homogenates. Administration of MEPA significantly (P < 0.05, P < 0.01; P < 0.01) decreased RTL (retention transfer latency) in rats on 7 th and 14 th day compared to the disease control and control group in the EPM test. In PA test the doses of MEPA suggestively (P < 0.05, P < 0.001; P < 0.05, P < 0.01) increased STL (step-through latency) in rats on 7 th and 14 th day with respect to disease control and control group. For NOR test administration of MEPA considerably (P < 0.01, P < 0.001; P < 0.01) increased the DI (discrimination index) in rats with respect to that of disease control and control group. The doses of MEPA markedly (P < 0.05, P < 0.01; P < 0.01) decreased EL (escape latency) and significantly (P < 0.01, P < 0.001; P < 0.05, P < 0.01) increased TSTQ (time spent in the target quadrant) on successive days as compared to that of disease control and control group in the acquisition trial of MWM test. In case of probe trial of MWM test MEPA administration considerably (P < 0.01; P < 0.05, P < 0.01) increased TSTQ and significantly (P < 0.05, P < 0.01; P < 0.05, P < 0.01) increased TSA (time spent in the annuli) in rats on successive days as compared to that of disease control and control group. MEPA administration significantly (P

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This present research was conducted to assess the bioaccumulation of toxic heavy metals in fish before and after six months feeding with synthetic feed. Here in concentrations of eight toxic heavy metals such as chromium (Cr), copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni), zinc (Zn), iron (Fe) and manganese (Mn) were determined by atomic absorption spectrophotometric (AAS) method. Before feeding, the concentrations in fish were found to be 19.5 ppb, 61.8, 30.5, 35.3, 123.3, 121.9, 197.7 and 543.2 ppb, respectively. And after feeding with synthetic feed, the concentrations were found to be 22.1 ppb, 101.5, 37.7, 102.0, 147.6, 214.1, 175.8 and 508.0 ppb, respectively. Contents of the trace metals in the feed, fresh water and the water after addition with synthetic feed were also evaluated. The Labeo rohita locally known as "Rui fish" has been selected for this study since it is a very popular fish in the rural as well as in urban peoples of Bangladesh. The accumulation of beneficial elements i.e., Cu, Zn, Fe and Mn were found to be within the permissible limit in both the fishes of before and after feeding with the synthetic feed. Concentrations of potential toxic metals i.e., Cd, Pb and Ni (37.7 ppb, 102.0, and 147.6 ppb, respectively) accumulated in the fish after six months feeding were found to be much higher than that of the recommended permissible limit. Concentrations of Cd, Pb and Ni (21.6 ppb, 102.0 and 114.0 ppb, respectively) in the synthetic feed used for feeding were also found to be much higher than the WHO/EU recommended value. Considering the potential health risk issues, it is recommended that the use of natural feed should be encouraged for feeding despite the synthetic feed in the fish firming project.

BackgroundBangladesh instituted a national lockdown to contain community transmission of COVID-19, initially for 10 days, from March 26 th to April 4 th , 2020, then extended successively through May 30 th . During the lockdown, the pandemic and its mitigation measures' impacts on social, economic, and financial aspects of life in Bangladesh were widely documented. i,ii iii Disruptions to the health system, particularly critical maternal health services, however, have received relatively less attention. This study analyzed potential impacts of COVID-19 and its related mitigation measures on maternal health services in Bangladesh, examining national and district trends in antenatal care (ANC), institutional delivery, and postnatal care (PNC) by utilizing publicly available routine service statistics from before, during, and after the lockdown. MethodsRoutine monthly service statistics from January through July 2020 from the Directorate General of Family Planning (DGFP) of Bangladesh's Ministry of Health and Family Welfare (MoHFW) were examined to determine ANC, institutional delivery, and PNC service trends. Analysis did not include statistics from the Directorate General of Health Service (DGHS), which are not publicly available. Comparisons with data from the first seven months of 2019 are presented to account for seasonal trends.