Inter‐ and intraspecific variation in body‐ and genome size in calanoid copepods from temperate and arctic waters

The tendency of ectotherms to get larger in the cold (Bergmann clines) has potentially great implications for individual performance and food web dynamics. The mechanistic drivers of this trend are not well understood, however. One fundamental question is to which extent variation in body size is attributed to variation in cell size, which again is related to genome size. In this study, we analyzed body and genome size in four species of marine calanoid copepods, Calanus finmarchicus, C. glacialis, C. hyperboreus and Paraeuchaeta norvegica, with populations from both south Norwegian fjords and the High Arctic. The Calanus species showed typical interspecific Bergmann clines, and we assessed whether they also displayed similar intraspecific variations—and if correlation between genome size and body size differed between species. There were considerable inter‐ as well as intraspecific variations in body size and genome size, with the northernmost populations having the largest values of both variables within each species. Positive intraspecific relationships suggest a functional link between body and genome size, although its adaptiveness has not been settled. Impact of additional drivers like phylogeny or specific adaptations, however, was suggested by striking divergences in body size – genome size ratios among species. Thus, C. glacialis and C. hyperboreus, had fairly similar genome size despite very different body size, while P. norvegica, of similar body size as C. hyperboreus, had the largest genome sizes ever recorded from copepods. The inter‐ and intraspecific latitudinal body size clines suggest that climate change may have major impact on body size composition of keystone species in marine planktonic food webs.     

Extracellular siderophores from Aspergillus ochraceous.

A large number of iron-chelating compounds (siderophores) were isolated from supernatants of iron-deficient cultures of a mold isolate, subsequently identified as Aspergillus ochraceous . Siderophores in their iron chelate form were purified to homogeneity by using Bio-Gel P2, silica gel, and C-18 bonded silica gel (reverse-phase) columns. Most of these compounds, as identified by 1H and 13C nuclear magnetic resonance spectroscopy and X-ray crystallography, belong to the ferrichrome family. The organism produces ferrirubin and ferrichrysin as the predominant and the second major compound (62 and 15% of the total siderophores), respectively. Ferrichrysin appears as the first siderophore in the medium on day 2 of growth. Several of the other siderophores are novel and ranged in quantities from 0.2 to 5% of the total. The trivial names asperchrome A, B1, B2, C, D1, D2, and D3 are proposed for these novel compounds, which are all members of the ferrichrome family, and all but the first one contain a common Orn1 - Orn2 - Orn3 - Ser1 -Ser2-Gly cyclic hexapeptide ring with three dissimilar ornithyl delta-N-acyl groups. Another compound which appeared late in the growth period was similar to fusarinine C ( fusigen ). All of these compounds showed growth factor activity to various extents in bioassays with Arthrobacter flavescens Jg-9. None of these compounds showed antibacterial activity against Escherichia coli or Bacillus megaterium.     

A report on three live births in women with poor ovarian response following intra-ovarian injection of platelet-rich plasma (PRP)

Molecular Biology Reports - The prevalence of poor response to gonadotropin stimulation is approximately 9–24% in women undergoing in vitro fertilization. Interestingly, due to containing a...     

Tight Coupling between Glucose and Mitochondrial Metabolism in Clonal ��-Cells Is Required for Robust Insulin Secretion

The biochemical mechanisms underlying glucose-stimulated insulin secretion from pancreatic β-cells are not completely understood. To identify metabolic disturbances in β-cells that impair glucose-stimulated insulin secretion, we compared two INS-1-derived clonal β-cell lines, which are glucose-responsive (832/13 cells) or glucose-unresponsive (832/2 cells). To this end, we analyzed a number of parameters in glycolytic and mitochondrial metabolism, including mRNA expression of genes involved in cellular energy metabolism. We found that despite a marked impairment of glucose-stimulated insulin secretion, 832/2 cells exhibited a higher rate of glycolysis. Still, no glucose-induced increases in respiratory rate, ATP production, or respiratory chain complex I, III, and IV activities were seen in the 832/2 cells. Instead, 832/2 cells, which expressed lactate dehydrogenase A, released lactate regardless of ambient glucose concentrations. In contrast, the glucose-responsive 832/13 line lacked lactate dehydrogenase and did not produce lactate. Accordingly, in 832/2 cells mRNA expression of genes for glycolytic enzymes were up-regulated, whereas mitochondria-related genes were down-regulated. This could account for a Warburg-like effect in the 832/2 cell clone, lacking in 832/13 cells as well as primary β-cells. In human islets, mRNA expression of genes such as lactate dehydrogenase A and hexokinase I correlated positively with HbA_1c levels, reflecting perturbed long term glucose homeostasis, whereas that of Slc2a2 (glucose transporter 2) correlated negatively with HbA_1c and thus better metabolic control. We conclude that tight metabolic regulation enhancing mitochondrial metabolism and restricting glycolysis in 832/13 cells is required for clonal β-cells to secrete insulin robustly in response to glucose. Moreover, a similar expression pattern of genes controlling glycolytic and mitochondrial metabolism in clonal β-cells and human islets was observed, suggesting that a similar prioritization of mitochondrial metabolism is required in healthy human β-cells. The 832 β-cell lines may be helpful tools to resolve metabolic perturbations occurring in Type 2 diabetes.     

Illuminating and mitigating the evolving impacts of COVID-19 on ethnocultural communities: a participatory action mixed-methods study

BACKGROUND:The COVID-19 pandemic has exacerbated disparities in poverty and illness for people in vulnerable circumstances in ethnocultural communities. We sought to understand the evolving impacts of COVID-19 on ethnocultural communities to inform intersectoral advocacy and community action.METHODS:The Illuminate Project used participatory action research, with cultural health brokers as peer researchers, from Sept. 21 to Dec. 31, 2020, in Edmonton, Alberta. Twenty-one peer researchers collected narratives from members of ethnocultural communities and self-interpreted them as they entered the narratives into the SenseMaker platform, a mixed-method data collection tool. The entire research team analyzed real-time, aggregate, quantitative and qualitative data to identify emerging thematic domains, then visualized these domains with social network analysis.RESULTS:Brokers serving diverse communities collected 773 narratives. Identified domains illuminate the evolving and entangled impacts of COVID-19 including the following: COVID-19 prevention and management; care of acute, chronic and serious illnesses other than COVID-19; maternal care; mental health and triggers of past trauma; financial insecurity; impact on children and youth and seniors; and legal concerns. We identified that community social capital and cultural brokering are key assets that facilitate access to formal health and social system supports.INTERPRETATION:The Illuminate Project has illustrated the entangled, systemic issues that result in poor health among vulnerable members of ethnocultural communities, and the exacerbating effects of COVID-19, which also increased barriers to mitigation. Cultural brokering and community social capital are key supports for people during the COVID-19 pandemic. These findings can inform policy to reduce harm and support community resiliency.

Mahatma Gandhi observed that “the true measure of any society can be found in how it treats its most vulnerable members.” Ethnocultural communities, defined by their unique shared characteristics (e.g., cultural traditions, language, country of origin),¹ face greater challenges and have higher rates of poverty and illness than the general Canadian population. Migration results in conditions that affect all social determinants of health and disproportionally affect health outcomes, herein referred to as vulnerable circumstances.^2,3 The emergence of major outbreaks of SARS-CoV-2 infections in ethnocultural communities highlights both the vulnerable circumstances of these communities and the disparities they face in accessing high-quality, culturally appropriate information and support.^4–7 Studies have shown substantial variation in deaths attributed to COVID-19 based on factors such as age, sex, ethnicity, length of time in Canada, income and education.^8–11 However, given the well-known gap in reporting comprehensive COVID-19 data in relation to race and ethnicity, efforts to measure its impact are hampered.^8–12 There is an urgent need to understand the evolving challenges of COVID-19 to inform action and public policy that can mitigate these challenges.To understand evolving situations of complexity and crisis, sensemaking, defined as “a continuous process to establish situational awareness,”¹³ is a crucial undertaking.¹⁴ Using participatory action research,^15–18 we sought to understand the evolving impacts of COVID-19 on ethnocultural communities to inform broader national efforts to migitate the impacts of COVID-19. Particularly, we sought to understand how the challenges of COVID-19 are entangled with contextual factors at multiple levels, how families and communities are leveraging strengths and social capital to adapt, and the role of cultural brokers in managing the crisis.     

Chemotaxis-mediated biodegradation of cyclic nitramine explosives RDX, HMX, and CL-20 by Clostridium sp. EDB2

Cyclic nitramine explosives, RDX, HMX, and CL-20 are hydrophobic pollutants with very little aqueous solubility. In sediment and soil environments, they are often attached to solid surfaces and/or trapped in pores and distribute heterogeneously in aqueous environments. For efficient bioremediation of these explosives, the microorganism(s) must access them by chemotaxis ability. In the present study, we isolated an obligate anaerobic bacterium Clostridium sp. strain EDB2 from a marine sediment. Strain EDB2, motile with numerous peritrichous flagella, demonstrated chemotactic response towards RDX, HMX, CL-20, and NO(2)(-). The three explosives were biotransformed by strain EDB2 via N-denitration with concomitant release of NO(2)(-). Biotransformation rates of RDX, HMX, and CL-20 by the resting cells of strain EDB2 were 1.8+/-0.2, 1.1+/-0.1, and 2.6+/-0.2nmol h(-1)mgwet biomass(-1) (mean+/-SD; n=3), respectively. We found that commonly seen RDX metabolites such as TNX, methylenedinitramine, and 4-nitro-2,4-diazabutanal neither produced NO(2)(-) during reaction with strain EDB2 nor they elicited chemotaxis response in strain EDB2. The above data suggested that NO(2)(-) released from explosives during their biotransformation might have elicited chemotaxis response in the bacterium. Biodegradation and chemotactic ability of strain EDB2 renders it useful in accelerating the bioremediation of explosives under in situ conditions.     

Fluorinated aminoglycosides and their mechanistic implication for aminoglycoside 3'-phosphotransferases from Gram-negative bacteria

Aminoglycoside 3'-phosphotransferases [APH(3')s] are important bacterial resistance enzymes for aminoglycoside antibiotics. These enzymes phosphorylate the 3'-hydroxyl of these antibiotics, a reaction that inactivates the drug. A series of experiments were carried out to shed light on the details of the turnover chemistry by these enzymes. Quench-flow pre-steady-state kinetic analyses of the reactions of Gram-negative APH(3') types Ia and IIa with kanamycin A, neamine, and their respective difluorinated analogues 4'-deoxy-4',4'-difluorokanamycin A and 4'-deoxy-4',4'-difluoroneamine were carried out, in conjunction with measurements of thio effect and viscosity studies. The fluorinated analogues were shown to be severely impaired as substrates for these enzymes. The magnitude of the effect of the impairment of the fluorinated substrates was in the same range as when the D198A mutant APH(3')-Ia was studied with nonfluorinated substrates. Residue 198 is the proposed active site base that promotes the aminoglycoside hydroxyl for phosphorylation. These findings collectively argue that the Gram-negative APH(3')s show significant nucleophilic participation in the transition state for the phosphate transfer reaction.     

Polyphenols of mature plant,seedling and tissue cultures of Theobroma cacao

The major flavone in mature cocoa leaves is isovitexin, with smaller amounts of vitexin and 7-O-glucosides of apigenin, luteolin and chrysoeriol. F     

Metabolite production during transformation of 2,4,6-trinitrotoluene (TNT) by a mixed culture acclimated and maintained on crude oil-containing media

Metabolites formed during 2,4,6-trinitrotoluene (TNT) removal by a mixed bacterial culture (acclimated and maintained on crude oil-containing medium and capable of high rates of TNT removal) were characterized. In resting cell experiments in the absence of glucose, 46.2 mg/l TNT were removed in 171 h (87.5% removal), with a combined total formation of 7.7 mg/l amino-4,6-dinitrotoluene (ADNT) and 0.3 mg/l 4,4-azoxytetranitrotoluene and 2,4-azoxytetranitrotoluene, leaving 70% of the initial TNT unaccounted for. In the presence of glucose, resting cells removed 45.4 mg/l TNT in 49 h (95.5% removal), with 9.1 mg/l ADNT and 2.4 mg/l azoxy compounds being produced, leaving 70.3% of the TNT unaccounted for. Growing cells (glucose present) were capable of removing 44.2 mg/l TNT within 21 h (97.9% removal), with the concomitant formation of 1.8 mg/l ADNTs and 2.2 mg/l azoxy compounds. Denitrated TNT in the form of 2,6-dinitrotoluene was also produced in growing cells with a maximum amount of 1.31 mg/l after 28 h, followed by a slight decrease with time, leaving 88.5% of the initial TNT unaccounted for after 171 h. Radiolabeled ¹⁴C-TNT studies revealed 4.14% mineralization after an incubation period of 163 days with growing cells.