Synthesis, crystal structure, nuclease and in vitro antitumor activities of a new mononuclear copper(II) complex containing a tripodal N3O ligand

We present here the synthesis, crystal structure, electrochemical behavior, spectroscopic properties (FT-IR, UV-Vis and EPR), nuclease and in vitro antitumor activities against human myeloid leukemia cell line of the mononuclear copper complex [Cu(HPClNOL)(Cl)]Cl · MeOH (1). The reaction of the tetradentate ligand HPClNOL [1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol] and 1 equiv. of [Cu(OH₂)₆](Cl)₂, in methanol, resulted in 1, which crystallizes as blue monoclinic crystals. The complex is pentacoordinated with a distorted square-pyramidal geometry. The activity of complex 1 toward plasmid DNA and THP-1 carcinogenic cells was investigated. Complex 1 promotes the cleavage of supercoiled DNA (pBlueScript KS⁺ DNA) to nicked circular and linear DNA forms. In addition to the three typical KS⁺ DNA forms, the cleavage resulted in a fourth band, which was visualized above of the nicked circular form. The results reveal that the cleavage mechanism is radical-independent. Furthermore, complex 1 is able to promote cell death of THP-1 cells by apoptosis, as confirmed by fluorescent microscopy, cell morphology and DNA degradation.     

Phylogeny and biogeography in the evolution of migration: shorebirds of the Charadrius complex

Aim We explore whether molecular phylogeny and biogeography can complement evolutionary ecology in developing a method to address a long-standing issue in the evolution of migration: have migrations between breeding and non-breeding grounds, which may be on different continents, evolved through origins in the breeding grounds with successive shifts of the non-breeding distribution or vice versa? Methods To accommodate the biology of migration, we treated breeding and non-breeding distributions as characters to be mapped onto a phylogeny derived from mitochondrial DNA sequence data and so examined the ancestral home issue as a study in the direction of character evolution. Results Our main findings from applying this approach to a subset of the Charadrius complex of shorebirds (Aves: Charadriinae) are that a case can be made for shifts of breeding distributions having occurred in the ancestries of C. alexandrinus and C. veredus as those species evolved their present migration patterns. Our results also argue for a southern hemisphere origin (specifically South America) for the Charadrius complex as a whole. A South American origin implies other shifts in breeding distributions having occurred in the evolution of the species C. semipalmatus and C. vociferus. On applying the methods we developed for dealing with phylogenetic uncertainty, these results are reinforced and the merit of testing them further is suggested. Conclusions By way of a new approach to the evolution of migration, our study adds to a consensus emerging from the evolutionary ecology of migrant birds, arguing that shifts of breeding distributions are commonly, though not necessarily exclusively, involved in the evolution of migration.     

Leveraging natural history biorepositories as a global,decentralized, pathogen surveillance network

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic reveals a major gap in global biosecurity infrastructure: a lack of publicly available biological samples representative across space, time, and taxonomic diversity. The shortfall, in this case for vertebrates, prevents accurate and rapid identification and monitoring of emerging pathogens and their reservoir host(s) and precludes extended investigation of ecological, evolutionary, and environmental associations that lead to human infection or spillover. Natural history museum biorepositories form the backbone of a critically needed, decentralized, global network for zoonotic pathogen surveillance, yet this infrastructure remains marginally developed, underutilized, underfunded, and disconnected from public health initiatives. Proactive detection and mitigation for emerging infectious diseases (EIDs) requires expanded biodiversity infrastructure and training (particularly in biodiverse and lower income countries) and new communication pipelines that connect biorepositories and biomedical communities. To this end, we highlight a novel adaptation of Project ECHO’s virtual community of practice model: Museums and Emerging Pathogens in the Americas (MEPA). MEPA is a virtual network aimed at fostering communication, coordination, and collaborative problem-solving among pathogen researchers, public health officials, and biorepositories in the Americas. MEPA now acts as a model of effective international, interdisciplinary collaboration that can and should be replicated in other biodiversity hotspots. We encourage deposition of wildlife specimens and associated data with public biorepositories, regardless of original collection purpose, and urge biorepositories to embrace new specimen sources, types, and uses to maximize strategic growth and utility for EID research. Taxonomically, geographically, and temporally deep biorepository archives serve as the foundation of a proactive and increasingly predictive approach to zoonotic spillover, risk assessment, and threat mitigation.

“We are not students of some subject matter, but students of problems. And problems may cut right across the borders of any subject matter or discipline.”–Karl Popper

     

Reproductive biology of the smooth butterfly ray Gymnura micrura

This study provides the first detailed information on the reproductive biology of the smooth butterfly ray Gymnura micrura. A total of 905 individuals were sampled, 377 of which were used for the reproductive study. Juveniles accounted for 75% of the sample, but all life cycle stages were present in the study area. The disc width at which 50% were mature (W(D50) )was estimated at 269 and 405 mm for males and females, respectively. The W(D50V) (based on the onset of vitellogenesis) was estimated at 359 mm. Uterine fecundity (mean ±s.d. = 3·8 ± 1·3; range: 1-6) was positively correlated with female size. A 3564% gain in mean wet mass was observed from egg to full-term embryo in utero. Size at birth ranged from 135 to 175 mm W(D) (19·5 to 55·0 g), with a mean of 165·1 mm W(D) (43·3 g). The embryo sex ratio was not significantly different from 1:1. The ovaries of pregnant females were undergoing vitellogenesis during gestation, with females ready to ovulate soon after parturition. Gymnura micrura may have an asynchronous reproductive cycle, with females reproducing continuously throughout the year.     

Effect of sodium bicarbonate supplementation on two different performance indicators in sports: a systematic review with meta-analysis

[Purpose]Sodium bicarbonate shows ergogenic potential in physical exercise and sports activities, although there is no strong evidence which performance markers show the greatest benefit from this supplement. This study evaluated the effects of sodium bicarbonate supplementation on time trial performance and time to exhaustion in athletes and sports practitioners.[Methods]A systematic review was conducted using three databases, including 17 clinical trials. Among these clinical trials, 11 were considered eligible for the meta-analysis according to the criteria for the assessment of methodological quality using the PEDro Scale. Time to exhaustion was assessed in six studies, while time trial performance was evaluated in five studies.[Results]A significant beneficial effect of supplementation on time to exhaustion was found in a random effects model (1.48; 95% confidence interval [CI], 0.49 to 2.48). There was no significant effect of supplementation on time trial performance in a fixed effects model (slope = −0.75; 95% CI, −2.04 to 0.55) relative to a placebo group.[Conclusion]Sodium bicarbonate has the potential to improve sports performance in general, especially in terms of time to exhaustion.     

Diet and feeding strategy of smooth butterfly ray Gymnura micrura in northeastern Brazil

The purpose of the present study was to analyze the diet of the smooth butterfly ray Gymnura micrura using qualitative and quantitative approaches to describe the feeding spectrum as well as ecological aspects related to feeding and niche width. The rays were obtained through monthly sampling as by‐catch from bottom trawl fisheries in northeastern Brazil from August 2007 to July 2008. A total of 286 stomachs were sampled, of which 176 contained food items. G. micrura is a predator in the region that feeds intermittently on large whole prey items, followed by a long period of digestion with simply little or no feeding activity. A low diversity of food items was found in the G. micrura diet, with an absolute predominance of teleosts, especially the roughneck grunt Pomadasys corvinaeformis. It is suggested that the species has a narrow feeding niche and a high degree of specialization. This presumed high degree of feeding specialization is discussed and the findings are compared in light of similar studies for closely related species, allowing to propose the family as primarily constituting piscivorous rays.