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Effect of sperm treatment with lysolecithin on in vitro outcomes of equine intracytoplasmic sperm injection
No full textIntracytoplasmic sperm injection (ICSI) in horses is currently employed for clinical and commercial uses, but the protocol could be optimized to improve its efficiency. We have hypothesized that destabilization of plasma and acrosomal membranes prior to injection would positively impact the developmental potential of equine zygotes generated by ICSI. This study evaluated effects of the sperm treatment with lysolecithin on plasma and acrosomal membranes and on oocyte activation ability, initially following heterologous ICSI on bovine oocytes and subsequently employing equine oocytes. The effects of the lysolecithin -treatment on the efficiency of conventional and piezo-assisted equine ICSI were evaluated. To do this, the equine sperm were treated with different concentrations of lysolecithin and the sperm plasma membrane, acrosome and DNA integrity were evaluated by flow cytometry. The results showed that a lysolecithin concentration of 0.08 % destabilized the membranes of all sperm and affected DNA integrity within the range described for the species (8-30 %). In addition, the heterologous ICSI assay showed that lysolecithin treatment was detrimental to the sperm's ability to activate the oocyte, therefore, chemical oocyte activation was used after equine ICSI after injection with lysolecithin -treated sperm. This group showed similar developmental rate to the control group with and without exogenous activation. In conclusion, lysolecithin pre-treatment is not necessary when using ICSI to produce equine embryos in vitro. The results from the current study provide additional insight regarding the factors impacting ICSI in horses
Effectiveness of aloe vera in patients with type 2 Diabetes Mellitus and pre-diabetes: An overview of systematic reviews
Get PDFBackground and aims: The effects of aloe vera are inconsistent and unclear. The aim of this study is to analyze the effects of aloe vera in metabolic profiles.
Methods: An electronic search of systematic reviews (SRs) was performed in seven databases up to June 2021.
Results: Four SRs met the eligibility criteria. In T2DM, SMD for FBG = -5.61 (p < 0.001). For HbA1c, MD = -0.95 (p = 0.02). In pre-diabetes, SMD for FBG = -1.41 (p = 0.02). For HbA1c, MD = -0.31 (p = 0.02). For TG, MD = -4.99 (p = 0.000).
Conclusion: There exist a moderate to high quality of evidence in favor of the effects of aloe vera in patients with T2DM and pre-diabetes
Fish sperm cryopreservation using biodegradable containers: New low-cost and environment-friendly methodology
No full textContainers used to cryopreserve sperm are made with non-biodegradable plastic compounds, having a high monetary and environmental cost. Therefore, the development of biodegradable alternative containers for cell cryopreservation is necessary. Thus, this study aimed to evaluate the efficiency of hard-gelatin and hard-hydroxypropyl methylcellulose (HPMC) capsules as low-cost and biodegradable alternative containers for sperm cryopreservation. Sperm from 12South American silver catfish Rhamdia quelen were individually cryopreserved in plastic straws 0.25 mL (as control), hard-gelatin, and hard-HPMC capsules. The quality of post-thaw sperm cryopreserved in the different containers was checked by measuring spermatozoa membrane integrity, kinetic parameters, mitochondrial activity, fertilization, hatching, and normal larvae rates. The samples cryopreserved in straws showed a higher percentage of membrane integrity (68%) than those frozen in hard-gelatin (40%) and hard-HPMC capsules (40%). However, we did not observe differences between the samples stored in straws and hard capsules for the rest of the tested sperm parameters. Thus, based on the high sperm fertility capability, both capsules were efficient as cryopreservation containers for maintaining sperm functionality
Novel Apoplastic Antifreeze Proteins of Deschampsia antarctica as Enhancer of Common Cell Freezing Media for Cryobanking of Genetic Resources, a Preliminary Study
No full textAntifreeze proteins (AFPs) are natural biomolecules found in cold-adapted organisms that lower the freezing point of water, allowing survival in icy conditions. These proteins have the potential to improve cryopreservation techniques by enhancing the quality of genetic material postthaw. , a freezing-tolerant plant, possesses AFPs and is a promising candidate for cryopreservation applications. In this study, we investigated the cryoprotective properties of AFPs from extracts on Atlantic salmon spermatozoa. Apoplastic extracts were used to determine ice recrystallization inhibition (IRI), thermal hysteresis (TH) activities and ice crystal morphology. Spermatozoa were cryopreserved using a standard cryoprotectant medium (C+) and three alternative media supplemented with apoplastic extracts. Flow cytometry was employed to measure plasma membrane integrity (PMI) and mitochondrial membrane potential (MMP) postthaw. Results showed that a low concentration of AFPs (0.05 mg/mL) provided significant IRI activity. Apoplastic extracts from demonstrated a cryoprotective effect on salmon spermatozoa, with PMI comparable to the standard medium. Moreover, samples treated with apoplastic extracts exhibited a higher percentage of cells with high MMP. These findings represent the first and preliminary report that suggests that AFPs derived from apoplastic extracts of have the potential to serve as cryoprotectants and could allow the development of novel freezing media
Microclimate, an important part of ecology and biogeography
No full textBrief introduction: What are microclimates and why are they important?Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next.Microclimate investigations in ecology and biogeographyWe highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles.Microclimate applications in ecosystem managementMicroclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity.Methods for microclimate scienceWe showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state-of-the-art of the field.What's next?We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management
Bioaugmentation of a Biobed Packing Material with an iprodione-degrading Bacterial Consortium Enhances the Dissipation of Iprodione and Mitigates Adverse Effects on the Microbiota
No full textIprodione (IPR) is a common contaminant of natural water resources. On-farm biopurification systems (BPS) like biobeds can degrade pesticides and prevent point source contamination. In cases of toxic or mobile chemicals like IPR, inoculation of biobed packing material (BPM) with specialized pesticide-degrading microorganisms can enhance BPS performance. Still, little is known about the efficiency of bioaugmentation against IPR and its effects on the BPM microbiota. We hypothesized that adding an IPR-degrading bacterial consortium (BC) in a BPS will enhance the transformation of IPR and its derivatives and alleviate their adverse impact on the BPM microbiota. We measured the transformation of IPR in BPM inoculated (BPM + IPR + BC) or not inoculated (BPM + IPR) with an IPR-degrading BC. Furthermore, the effects of IPR on the activity of key soil microbial enzymes and on the abundance of total bacteria, fungi, and specific bacterial taxa were determined in the above treatments compared with a control (BPM). BPM bioaugmentation accelerated IPR degradation in BPM + IPR + BC (t1/2: 4.3 d) compared to BPM + IPR (t1/2: 9.1 d). Accordingly, significantly lower enzymatic activities and abundances of total fungi, total bacteria, Pseudomonadota, Actimycetota, and Bacillota were evident in the first 14 days in BPM + IPR compared to BPM and BPM + IPR + BC. However, the effects were transient, and recovery was observed thereafter. Bioaugmentation of BPM with an IPR-degrading BC accelerated the dissipation of IPR and its derivatives and led to mitigation of the toxicity of IPR to the activity and abundance of the BPM microbiota
High-Order Commensurate Zwitterionic Quinonoid Phase Induces a Nanoscale Dipole Lattice on Graphene
No full textSince the introduction of hybrid van der Waals heterostructures (h-vdWHs) for device architecture development, many vertically staked organic two-dimensional materials have been investigated in order to control transport properties. This article introduces a novel h-vdWH that achieves periodic interaction by the development of a superlattice. We describe a complete investigation of the diphenyl-functionalized p-benzoquinonemonoimine zwitterion on highly oriented pyrolytic graphite and monolayer graphene using high-resolution scanning tunneling microscopy images and numerical simulations. The molecular phase on both substrates exhibits a structurally identical antiparallel dipole alignment in a head-to-tail dimer configuration. Density functional theory calculations reveal that this molecular adsorption induces a local dipole at the graphene interface due to the rearrangement of the electron density distribution
La configuración de la flexibilización laboral. 50 años de transformaciones internacionales del mundo del trabajo
No full textA partir del estudio de diversas investigaciones, este artículo aborda los cambios en el mundo del trabajo desde la década de 1970, influenciados por el capitalismo industrial y marcados por la transformación laboral a través de una mayor flexibilidad laboral y la disminución de la seguridad en el empleo. Estos cambios fueron respuestas a las turbulencias económicas y a los avances tecnológicos que condujeron a un aumento del desempleo y a una disminución de la influencia sindical en la política laboral. Se subraya la importancia de adoptar una perspectiva sincrónica para comprender la historia del trabajo, donde diversas formas de relaciones laborales coexisten en el contexto del ca-pitalismo en momentos específicos. Se destacan diversos modelos de trabajo, tanto a nivel internacional como nacional, lo que refleja la dimensión global de este fenómeno. La flexibilidad laboral y la precariedad afectaron a sectores de la fuerza laboral en condiciones inestables, mientras que otros disfrutaron de mejores condiciones laborales en sociedades capitalistas, tanto en el núcleo como en la periferia. La experiencia chilena desde el golpe de Estado de 1973 se integra en este contexto histórico de transformaciones en el mundo del tra-bajo, caracterizado por la aplicación de concepciones neoliberales críticas en cuanto a la expansión de los derechos laborales y la seguridad en el empleo.In light of various research studies, this article examines changes in the world of work since the 1970s, influenced by industrial capitalism and marked by labor transformation through increased labor flexibility and redu-ced job security. These changes were responses to economic turbulence and technological advancements, which resulted in rising unemployment rates and a decrease in labor union influence in labor policy. The importance of adop-ting a synchronic perspective is emphasized to understand the history of labor, where various forms of labor relations coexist in the context of capitalism at specific moments. Various models of labor, both on an international and natio-nal scale, are highlighted, reflecting the global dimension of this phenomenon. Labor flexibility and precariousness affected sectors of the workforce in uns-table conditions, while others enjoyed better labor conditions in capitalist so-cieties, both in the core and periphery. The Chilean experience since the coup d'état of 1973 is integrated into this historical context of transformations in the world of work, characterized by the application of critical neoliberal concepts regarding the expansion of labor rights and job security
La región mendosanjuanina. Una nueva territorialidad económica para Mendoza, San Juan y San Luis en el siglo XVIII
No full textEste artículo busca demostrar la existencia de una territorialidad eco-nómica llamada la región mendosanjuanina para el siglo XVIII, así como problematizar la existencia económica de lo que la historiografía denomina Cuyo. Para ello se analiza a las economías de Mendoza, San Juan y San Luis a partir de distintas variables y dinámicas económicas. Las conclusiones alcanzadas permi-ten analizar las diferencias existentes entre la economía de la región mendosan-juanina y San Luis. El trabajo combina la utilización de los datos aportados por la historiografía y por las fuentes documentales conservadas en el Archivo General de la Provincia de Mendoza y el Archivo General de la Nación Argentina.This article aims to demonstrate the existence of an economic territoriality called the Mendosanjuanina region during the eighteenth century and to problematize the economic existence of what historiography calls Cuyo. To this end, the economies of Mendoza, San Juan and San Luis are examined from different variables and economic dynamics. The conclusions reached allow us to analyze the differences between the economy of the Mendoza region and San Luis. The work combines the use of data provided by historiography and documentary sources preserved in the General Provincial Archive of Mendoza and the General Archive of the Nation of Argentina
Crustáceos planctónicos crustáceo em baías com estado trófico diferente no lago Llanquihue (41° S Chile)
Get PDFThe Llanquihue lake is included in the called Araucanian or Nord Patagonian lakes located between 38-41° S. These lakes are characterized by their oligo-mesotrophic status due to human intervention which takes to the increase in nutrients inputs from industries and towns. Effects on zooplankton assemblages are observed with marked increase of daphnids abundance. The aim of the present study is to analyze the trophic status and zooplankton relative abundance in different bays of Llanquihue lake. It was found direct associations between chlorophyll a with daphnids percentage, total dissolved nitrogen with reactive soluble phosphorus nitrogen/phosphorus molar radio with cyclopoids percentage, and an inverse relation between daphnids and calanoids percentages. The occurrence of three kinds of microcrustacean assemblages and environmental conditions was evidenced: the first one with high calanoids percentage, low species number and low chlorophyll and nutrients concentration, a second with moderate chlorophyll and nutrients concentration and moderate daphnids percentage; high species number and a third site with high chlorophyll and nutrients concentration, high daphnids percentage and high species number. Daphnids increase under mesotrophic status, agree with similar results observed for southern Argentinean and New Zealand lakes.O lago Llanquihue está incluído nos chamados lagos araucana ou Nord Patagônia localizado entre 38-41° S. Estes lagos são caracterizados pela condicao oligo-mesotrofica debido a intervencao humana, com aumento da carga de nutrientes provenientes de industrias y areas urbanas com efeitos sobre as assembleias zooplantonicas sao observadas, com aumento acentuado de dafnideos. O objetivo do presente estudo é analisar o estado trófico a abundancia relative do zooplancton em diferentes compartimentos do lago Llanquihue. Foram encontradas associações diretas entre clorofila a com percentual de dafinídeos, nitrogênio total dissolvido com fósforo solúvel reativo molares razao molar nitrogênio / fósforo com percentual de ciclopóides, e uma relação inversa entre percentuais de dafinídeos e calanóides porcentagens. A ocorrência de três tipos de assembleias de microcrustáceos e as condições ambientais fora: a primeira com alta porcentais de calanóides, baixo número de espécies e baixa clorofila e a nutrientes, uma segunda com concentracoes moderadas de clorofila e nutrientes percentual moderado de daphnideos e alto número de espécies; e uma terceiro local com alta concentração de clorofila e nutrientes, alta abundância dafinídeos e número elevado de espécies. Resultados similares com aumento de dafnideos em condicoes mesotroficas também foram observados para lagos da Argentina e Nova Zelândia do sul