FSR19 and FSR25 confirmed as two new faint and metal-rich globular clusters in the galactic bulge

We combined the near-IR photometry from the VISTA Variables in the Vía Láctea extended Survey (VVVX) with Gaia EDR3 catalog to study some properties of FSR19 and FSR25. These are confirmed to be low luminosity metal-rich bulge globular clusters (Obasi et al. 2020). The proper motions (PM) remain unchanged and the Color magnitude diagrams (CMD) are consistent with what we previously reported and the red giant branches are narrower than the field

Phenotypic gender in Hormathophylla spinosa (Brassicaceae), a perfect hermaphrodite with tetradynamous flowers, is variable

Abstract. Angiosperms show an evolutionary trend from an indefinite to a fixed number of floral organs. When floral formula inconstancy in recent angiosperms is reported, it is often considered as a byproduct of stress and its fitness consequences remain mostly unexplored. We report substantial nonhomeotic meristic variation in stamen number (0-10 stamens per flower) in two populations of Hormathophylla spinosa during four years. This variation was plastic, suggesting its functional role in the adjustment of phenotypic gender. However, no correlations were found between phenotypic gender and plant size, pollinator or herbivore abundance. Effects on female reproductive success were inconsistent on a per-flower and on a perplant basis, rendering adaptive explanations in terms of selfing or resource adjustment unsatisfactory with the data available. Nevertheless, individuals showing larger interannual variation in phenotypic gender showed higher female reproductive success, suggesting an advantage for gender modification. Although our results do not easily conform to any adaptive explanation, this remarkable example of breakdown of trait canalization should stimulate the study of the mechanisms and ultimate causes responsible for the maintenance of fixed floral traits

ENGINEERING BIOCERAMIC MICROSTRUCTURE FOR CUSTOMIZED DRUG DELIVERY

One of the most efficient approaches to treat cancer and infection is to use biomaterials as a drug delivery system (DDS). The goal is for the material to provide a sustained release of therapeutic drug dose locally to target the ill tissue without affecting other organs. Silica Calcium Phosphate nano composite (SCPC) is a drug delivery platform that successfully demonstrated the ability to bind and release several therapeutics including antibiotics, anticancer drugs, and growth factors. The aim of the present work is to analyze the role of SCPC microstructure on drug binding and release kinetics. The main crystalline phases of SCPC are a-cristobalite (SiO2, Cris) and ß- rhenanite (NaCaPO4, Rhe); therefore, these two phases were prepared and characterized separately. Structural and compositional features of Cris, Rhe and SCPC bioceramics demonstrated a significant influence on the loading capacity and the release kinetics profile of Vancomycin (Vanc) and Cisplatin (Cis). Fourier Transform Infrared (FTIR) spectroscopy analyses demonstrated the high affinity between the P-O functional groups, in Rhe and SCPC, and the (C=O and N-H) of Vanc and (N-H and O-H) of Cis. By contrast, a weak chemical interaction between the Si-O functional group in Cris and SCPC and the two drugs was observed. Vanc loading per unit surface area increased in the order 8.00 µg Vanc/m2 for Rhe > 4.49 µg Vanc /m2 for SCPC>3.01 µg Vanc /m2 for Cris (p<0.05). Cis loading capacity increased in the order 8.59 µg Vanc /m2 for Cris, 17.8 µg Vanc/m2 for Rhe and 6.03 µg Vanc /m2 for SCPC (p<0.05). The drug release kinetics was dependent on the carrier as well as on the kind of drug. Different burst release and sustained release rates were measured for Vanc and Cis from the same carrier. The percentages of the amount of drug amount released from Cris, Rhe and SCPC during the burst stage (the first 2h) were: 50%, 50%, and 46% of Vanc; and 53.4%, 36.6%, and 30.6 % of Cis, respectively. Burst release correlated with the pore size distribution and surface area. Furthermore, the average rates of sustained release in the period 8-216h from Cris, Rhe and SCPC were: 9.8, 7.2 and 3.5 µg/h of Vanc and 4.5, 5.3 and 3.5 µg/h of Cis, respectively. Nearly inert Cris ceramic showed release kinetics controlled by its hierarchical nanoporous structure. On the other hand, the phase composition and surface chemistry of bioactive Rhe or SCPC ceramics overruled the effect of surface area. The relatively low rate of drug release from SCPC was due to the dissolution-back precipitation reaction taking place on the material surface as confirmed by FTIR bands of surface hydroxyapatite layer at 576.5, 596.7 and 620.7 cm-1. Moreover, the solid solution of crystalline phases of SCPC enhanced the bioactivity of the composite. Nuclear Magnetic Resonance (NMR) and cell culture analyses demonstrated that the interactions between the SCPC dissolution products and the released drug did not cause measurable negative effects on the bioactivity of the tested drugs. The therapeutic effects of the SCPC-Cis hybrid were evaluated using a rat model of hepatocellular carcinoma (HCC). Animals were treated by either systemic cisplatin injection (sCis), or with SCPC-Cis hybrid placed adjacent (ADJ) to, or within (IT), the tumor. Five days after implantation 50-55% of the total cisplatin loaded was released from the SCPC-Cis hybrids resulting in an approximately 50% decrease in tumor volume compared to sCis treatment. Severe side effects were observed in animals treated with sCis including rapid weight loss and decreased liver and kidney function; such effects were not observed in SCPC-Cis treated animals. Analysis of cisplatin distribution demonstrated drug concentrations in the tumor were 21 and 1.5-times higher in IT and ADJ groups, respectively, as compared to sCis treated animals. These data demonstrate the SCPC drug delivery system can provide an effective localized treatment for HCC with significantly reduced toxicity compared to systemic drug administration. Moreover, it is possible to tailor drug release kinetics from SCPC hybrids by controlling the crystalline structure of the material and the ratios of Cris and Rhe in the composite

From prebiotic chemistry to cellular metabolism—The chemical evolution of metabolism before Darwinian natural selection.

Abstract It is generally assumed that the complex map of metabolism is a result of natural selection working at the molecular level. However, natural selection can only work on entities that have three basic features: information, metabolism and membrane. Metabolism must include the capability of producing all cellular structures, as well as energy (ATP), from external sources; information must be established on a material that allows its perpetuity, in order to safeguard the goals achieved; and membranes must be able to preserve the internal material, determining a selective exchange with external material in order to ensure that both metabolism and information can be individualized. It is not difficult to understand that protocellular entities that boast these three qualities can evolve through natural selection. The problem is rather to explain the origin of such features under conditions where natural selection could not work. In the present work we propose that these protocells could be built by chemical evolution, starting from the prebiotic primordial soup, by means of chemical selection. This consists of selective increases of the rates of certain specific reactions because of the kinetic or thermodynamic features of the process, such as stoichiometric catalysis or autocatalysis, cooperativity and others, thereby promoting their prevalence among the whole set of chemical possibilities. Our results show that all chemical processes necessary for yielding the basic materials that natural selection needs to work may be achieved through chemical selection, thus suggesting a way for life to begin.

Ferroelectricity free lead halide perovskites

Direct piezoelectric force microscopy DPFM is employed to examine whether or not lead halide perovskites exhibit ferroelectricity. Compared to conventional piezoelectric force microscopy, DPFM is a novel technique capable of measuring piezoelectricity directly. This fact is fundamental to be able to examine the existence of ferroelectricity in lead halide perovskites, an issue that has been under debate for several years. DPFM is used to detect the current signals, i.e. changes in the charge distribution under the influence of the scan direction and applied force of the atomic force microscope AFM tip in contact mode. For comparison, i we use DPFM on lead halide perovskites and well known ferroelectric materials i.e. periodically poled lithium niobate and lead zirconate titanate ; and ii we conduct parallel experiments on MAPbI3 films of different grain sizes, film thicknesses, substrates, and textures using DPFM as well as piezoelectric force microscopy PFM and electrostatic force microscopy EFM . In contrast to previous work that claimed there were ferroelectric domains in MAPbI3 perovskite films, our work shows that the studied perovskite films Cs0.05 FA0.83MA0.17 0.95Pb I0.83Br0.17 3 and MAPbI3 are ferroelectricity free. The observed current profiles of lead halide perovskites possibly originate from ion migration that happens under an applied electrical bias and in strained samples under mechanical stress. This work provides a deeper understanding of the fundamental physical properties of the organic inorganic lead halide perovskites and solves a longstanding dispute about their non ferroelectric character an issue of high relevance for optoelectronic and photovoltaic application

AISLAMIENTO DE ADN GENÓMICO DE Myrciaria dubia (HBK) “CAMU CAMU” APROPIADO PARA ANÁLISIS MOLECULARES

Myrciaria dubia “camu-camu”, una especie nativa de la Amazonía que produce frutos con alto contenido de vitamina C y otras sustancias importantes. Sin embargo, los estudios moleculares de esta planta son escasos, por falta de un protocolo reproducible para purificar sus ácidos nucléicos. El objetivo de este trabajo fue establecer un protocolo para aislar el ADN genómico a partir de hojas de M. dubia, apropiado para análisis moleculares. El ADN se purificó con un protocolo modificado, la calidad y cantidad se estimó por espectrofotometría y electroforesis en gel de agarosa. Adicionalmente, la calidad se evaluó mediante RAPD. El ratio de calidad (A260/A280) promedio del ADN fue 1.9±0.1 y el espectro de absorción UV/Vis presentó un único pico de máxima absorbancia a 260nm. Mediante electroforesis el ADN fue íntegro y sin ARN. También, la síntesis de amplicones RAPD nos sugiere ausencia de inhibidores para polimerasas. La concentración promedio del ADN fue 99±33 ng/ml y el rendimiento promedio fue 237±80 mg ADN/g hoja. En conclusión, se ha establecido un protocolo de aislamiento de ADN genómico a partir de hojas de Myrciaria dubia “camu camu”, caracterizado por permitirnos obtener ADN de alta calidad y cantidad suficiente para análisis moleculares como el RAPD

Lengthweight relationship and parameters of growth for the checkered puffer Sphoeroides testudineus from a karstic tropical coastal lagoon: La Carbonera, Yucatan, Mexico

Summary This study reports length-weight relationships and growth parameters for Sphoeorides testudineus from La Carbonera, a karstic tropical coastal lagoon on the northwestern coast of the Yucatan Peninsula, Mexico. A total of 461 specimens were collected between April 2009 and March 2010. The lengthweight relationship was W = 0.061Lt 2.98 . Model parameters of the von Bertalanffy growth equation were: L ∞ = 29.50 cm, k = 0.77 year À1 and t 0 = À0.168 years. Introduction Sphoeroides testudineus, a member of the Tetraodontidae family, is known colloquially as checkered puffer and locally as 'xpu' (Mayan) and 'pez globo' (Spanish). It is an important estuarine-dependent fish species of ecological and commercial importance. The checkered puffer is the dominant species in many Yucatan coastal lagoons (Arceo-Carranza and Vega-Cendejas, 2009). The aim of this study was to present the LWR and to estimate the parameters of growth of S. testudineus from La Carbonera lagoon in northwestern Yucatan Peninsula. Materials and methods Samples of S. testudineus were collected during daytime between April 2009 and March 2010 in La Carbonera lagoon, a karstic coastal lagoon in northwestern Yucatan Peninsula, Mexico (21°13′-21°14′N; 89°52′-89°54′W). Collected specimens were euthanized in ice slurry, preserved in formaldehyde (4%) and transported to the laboratory where they were measured (±0.1 mm) and weighed (±0.01 g). The collected fishes were classified under three climatic seasons representing dry (March-June), rainy (July-October), and when there were prevailing north winds (NovemberFebruary). To determine parameters a and b, a regression analysis of log-converted total weight and total length was used. The 95% confidence intervals for b (CI 95%) were calculated to determine if the hypothetical value of isometry (3) fell between these intervals ÀkðtÀt0Þ , where Lt is the length at age t, L ∞ is asymptotic length, k is the growth rate (year À1 ) and t 0 is the hypothetical age of fish at length zero. The growth performance index (u') proposed by Results and discussion From a total of 461 of S. testudineus collected during the study period, 33.8% were collected in the dry season, 30.2% in the rainy season and 36% during the season when north winds prevaile

Influence of 1 and 25 Hz,1.5 mT Magnetic Fields on Antitumor Drug Potency in a Human Adenocarcinoma Cell Line

The resistance of tumor cells to antineoplastic agents is a major obstacle during cancer chemotherapy. Many authors have observed that some exposure protocols to pulsed electromagnetic fields (PEMF) can alter the efficacy of anticancer drugs; nevertheless, the observations are not clear. We have evaluated whether a group of PEMF pulses (1.5 mT peak, repeated at 1 and 25 Hz) produces alterations of drug potency on a multidrug resistant human colon adenocarcinoma (HCA) cell line, HCA-2/1 cch . The experiments were performed including (a) exposures to drug and PEMF exposure for 1 h at the same time, (b) drug exposure for 1 h, and then exposure to PEMF for the next 2 days (2 h/day). Drugs used were vincristine (VCR), mitomycin C (MMC), and cisplatin. Cell viability was measured by the neutral red stain cytotoxicity test. The results obtained were: (a) The 1 Hz PEMF increased VCR cytotoxicity (P < 0.01), exhibiting 6.1% of survival at 47.5 mg/ml, the highest dose for which sham exposed groups showed a 19.8% of survival. For MMC at 47.5 mg/ml, the % of survival changed significantly from 19.2% in sham exposed groups to 5.3% using 25 Hz (P < 0.001). Cisplatin showed a significant reduction in the % of survival (44.2-39.1%, P < 0.05) at 25 Hz and 47.5 mg/ml, and (b) Minor significant alterations were observed after nonsimultaneous exposure of cells to PEMF and drug. The data indicate that PEMF can induce modulation of cytostatic agents in HCA-2/1 cch , with an increased effect when PEMF was applied at the same time as the drug. The type of drug, dose, frequency, and duration of PEMF exposure could influence this modulation

COLLABORATIVE MODELING TO EVALUATE WATER MANAGEMENT SCENARIOS IN THE RIO GRANDE BASIN 1

ABSTRACT: This article describes the collaborative modeling process and the resulting water resources planning model developed to evaluate water management scenarios in the transboundary Rio Grande basin. The Rio Grande is a severely water stressed basin that faces numerous management challenges as it crosses numerous jurisdictional boundaries. A collaborative process was undertaken to identify and model water management scenarios to improve water supply for stakeholders, the environment, and international obligations of water delivery from Mexico to the United States. A transparent and open process of data collection, model building, and scenario development was completed by a project steering committee composed of university, nongovernmental, and governmental experts from both countries. The outcome of the process was a planning model described in this article, with data and operations that were agreed on by water planning officials in each country. Water management scenarios were created from stakeholder input and were modeled and evaluated for effectiveness with the planning model. (KEY TERMS: Rio Grande; decision support systems; planning; geographic information system; water resources management.