BACTERIAL FLORA IN THE DIGESTIVE TRACT OF HELIX ASPERSA MÜLLER SNAILS UNDER TWO BREEDING SYSTEMS

El objetivo del estudio fue comparar la flora bacteriana de intestino y hepatopáncreas del caracol Helix aspersa Müller criados en dos sistemas de producción: intensivo y extensivo. Se colectaron 30 caracoles adultos aparentemente sanos por cada sistema de producción, en seis criaderos ubicados en la provincia de Lima. Se tomó muestras de mucosa intestinal y parénquima del hepatopáncreas de cada individuo, empleando protocolos de aislamientos establecidos para bacterias aerobias y aerobias facultativas. Se aisló bacterias de 15 géneros: Escherichia, Citrobacter, Klebsiella, Enterobacter, Serratia, Hafnia, Proteus, Providencia, Aeromonas, Staphylococcus, Streptococcus, Enterococcus, Micrococcus, Pseudomonas, Acinetobacter; y bacilos gramnegativos no fermentadores (BNF). Se obtuvo 193 cepas en las muestras de caracoles del sistema extensivo, donde el género Escherichia fue el de mayor frecuencia (17.1%, 33/193); mientras que en caracoles del sistema intensivo se aisló 183 cepas, donde el género Klebsiella fue el de mayor frecuencia (17.5%, 32/183). Por otro lado, el género más frecuentemente aislado en intestino y hepatopáncreas fue Klebsiella (13.6%, 25/184 y 17.2%, 33/192, respectivamente). Bacterias de los géneros Providencia y Micrococcus solo se encontraron en el hepatopáncreas. Hubo diferencias estadísticas en la frecuencia de algunas bacterias aisladas dentro de cada tipo de muestra por efecto del sistema de crianza.El objetivo del estudio fue comparar la flora bacteriana de intestino y hepatopáncreas del caracol Helix aspersa Müller criados en dos sistemas de producción: intensivo y extensivo. Se colectaron 30 caracoles adultos aparentemente sanos por cada sistema de producción, en seis criaderos ubicados en la provincia de Lima. Se tomó muestras de mucosa intestinal y parénquima del hepatopáncreas de cada individuo, empleando protocolos de aislamientos establecidos para bacterias aerobias y aerobias facultativas. Se aisló bacterias de 15 géneros: Escherichia, Citrobacter, Klebsiella, Enterobacter, Serratia, Hafnia, Proteus, Providencia, Aeromonas, Staphylococcus, Streptococcus, Enterococcus, Micrococcus, Pseudomonas, Acinetobacter; y bacilos gramnegativos no fermentadores (BNF). Se obtuvo 193 cepas en las muestras de caracoles del sistema extensivo, donde el género Escherichia fue el de mayor frecuencia (17.1%, 33/193); mientras que en caracoles del sistema intensivo se aisló 183 cepas, donde el género Klebsiella fue el de mayor frecuencia (17.5%, 32/183). Por otro lado, el género más frecuentemente aislado en intestino y hepatopáncreas fue Klebsiella (13.6%, 25/184 y 17.2%, 33/192, respectivamente). Bacterias de los géneros Providencia y Micrococcus solo se encontraron en el hepatopáncreas. Hubo diferencias estadísticas en la frecuencia de algunas bacterias aisladas dentro de cada tipo de muestra por efecto del sistema de crianza

ESTUDIO PRELIMINAR DE COLECCIÓN DE SEMEN EN OSO DE ANTEOJOS (Tremarctos ornatus)

Semen was collected in a Spectacled Bear (Tremarctos ornatus) reared in captivity using the electroejaculation technique. Four series of 6 volt discharges by 15 seconds each plus manual stimulation were carried out. An effective penis erection and small volume of ejaculate was obtained in the last series of electrical stimulus. Seminal motility was 50%. Further studies are required to optimize the use of the electroejaculator in order to obtain higher volumes and better semen quality.Semen was collected in a Spectacled Bear (Tremarctos ornatus) reared in captivity using the electroejaculation technique. Four series of 6 volt discharges by 15 seconds each plus manual stimulation were carried out. An effective penis erection and small volume of ejaculate was obtained in the last series of electrical stimulus. Seminal motility was 50%. Further studies are required to optimize the use of the electroejaculator in order to obtain higher volumes and better semen quality

LEPTIN DETERMINATION AND SERUM LEVELS IN ADULT ALPACAS WITH DIFFERENT BODY CONDITION

El presente estudio tuvo como objetivo determinar la presencia de la hormona leptina en alpacas adultas, cuantificar sus valores y relacionarlos con la condición corporal. Se utilizaron 36 alpacas hembras adultas, vacías y sin cría, las cuales fueron divididas en dos grupos, según su condición corporal (CC): G1: CC <3.0 y G2: CC >3.0, de acuerdo a una escala 1 - 5 (1: emaciada, 5: obesa). Se tomaron muestras de sangre por punción de la vena yugular y el suero resultante fue mantenido en congelación a –20 ºC hasta su análisis. La determinación de leptina fue realizada mediante la técnica de radioinmunoensayo (RIA). La media general de la concentración de leptina fue de 17.23 ± 0.81 ng/ml. Los valores encontrados para G1 fueron de 18.14 ± 1.12 ng/ml y para G2: 16.32 ± 1.15 ng/ml, sin diferencias estadísticas entre grupos. Los resultados obtenidos permiten evidenciar la presencia de leptina en alpacas.The aim of this study was to determine the presence of leptin in adults alpacas, in order to quantify leptin values for these animals, and to relate them with body condition. For this purpose, 36 non pregnant and non nursing female adult alpacas were used. They were divided in two groups according to body condition (BC): G1: BC <3.0 and G2: BC>3.0, using the 1 to 5 scale (1: emaciate, 5: obese). Blood samples by jugular venipunction to obtain serum were taken. Serum samples were maintained at -20 ºC until analysis. The leptin determination was carried out by the radioimmunoassay technique (RIA). The mean of leptin concentration was 17.23 ± 0.81 ng/ml. Values for G1 were 18.14 ± 1.12 ng/ ml and for G2. were 16.32 ± 1.15 ng/ml, without statistical differences between groups. The results showed that the leptin hormone is also present in alpacas

Leptin determination and serum levels in adult alpacas with different body condition

El presente estudio tuvo como objetivo determinar la presencia de la hormona leptina en alpacas adultas, cuantificar sus valores y relacionarlos con la condición corporal. Se utilizaron 36 alpacas hembras adultas, vacías y sin cría, las cuales fueron divididas en dos grupos, según su condición corporal (CC): G1: CC 3.0, de acuerdo a una escala 1 - 5 (1: emaciada, 5: obesa). Se tomaron muestras de sangre por punción de la vena yugular y el suero resultante fue mantenido en congelación a –20 ºC hasta su análisis. La determinación de leptina fue realizada mediante la técnica de radioinmunoensayo (RIA). La media general de la concentración de leptina fue de 17.23 +- 0.81 ng/ml. Los valores encontrados para G1 fueron de 18.14 +- 1.12 ng/ml y para G2: 16.32 +- 1.15 ng/ml, sin diferencias estadísticas entre grupos. Los resultados obtenidos permiten evidenciar la presencia de leptina en alpacas

A λ-lemma for Normally Hyperbolic Invariant Manifolds

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Current State of Conservation Knowledge on Threatened Amphibian Species in Peru

This study documents the current state of conservation knowledge on threatened amphibian species in Peru. Following the International Union for the Conservation of Nature (IUCN) classification system, we considered species in the following categories: Critically Endangered, Endangered, Vulnerable, and Near Threatened. Even though only the first three categories are regarded as threatened by IUCN, we included the fourth category to make comparisons with the list of threatened species issued by the Peruvian government. We used the Global Amphibian Assessment\u27s database and the list issued in Peru for this comparison. We conducted separate field surveys in 17 regions of Peru to evaluate the presence/absence of threatened amphibian species and species that are potentially threatened. We also used the Declining Amphibian Database-DAPTF, to compare our results with previous assessments on population declines, and the World Wildlife Fund\u27s Wildfinder database, to determine in which Neotropical ecoregion each species occurs. We compiled data on 83 species, 44 of which are recognized as threatened by the IUCN and/or the Peruvian government. The remaining 39 species should be re-assessed as they face various threats. A re-evaluation of current estimates is needed as only 8% of all species recorded in Peru are recognized as threatened by the government, whereas the global estimate of threatened species is about 32%. In addition to using IUCN criteria, this re-assessment should follow national guidelines standardized in Peru and be in accordance with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Because the habitat of almost 40% of threatened species reported herein still remains unprotected, and data on chytridiomycosis and other threats are lacking for most taxa, it is crucial to develop strategies for habitat conservation and research on disease dynamics in natural populations

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Physical association of low density lipoprotein particles and extracellular vesicles unveiled by single particle analysis

Abstract Extracellular vesicles (EVs) in blood plasma are recognized as potential biomarkers for disease. Although blood plasma is easily obtainable, analysis of EVs at the single particle level is still challenging due to the biological complexity of this body fluid. Besides EVs, plasma contains different types of lipoproteins particles (LPPs), that outnumber EVs by orders of magnitude and which partially overlap in biophysical properties such as size, density and molecular makeup. Consequently, during EV isolation LPPs are often co‐isolated. Furthermore, physical EV‐LPP complexes have been observed in purified EV preparations. Since co‐isolation or association of LPPs can impact EV‐based analysis and biomarker profiling, we investigated the presence and formation of EV‐LPP complexes in biological samples by using label‐free atomic force microscopy, cryo‐electron tomography and synchronous Rayleigh and Raman scattering analysis of optically trapped particles and fluorescence‐based high sensitivity single particle flow cytometry. Furthermore, we evaluated the impact on flow cytometric analysis in the presence of LPPs using in vitro spike‐in experiments of purified tumour cell line‐derived EVs in different classes of purified human LPPs. Based on orthogonal single‐particle analysis techniques we demonstrate that EV‐LPP complexes can form under physiological conditions. Furthermore, we show that in fluorescence‐based flow cytometric EV analysis staining of LPPs, as well as EV‐LPP associations, can influence quantitative and qualitative EV analysis. Lastly, we demonstrate that the colloidal matrix of the biofluid in which EVs reside impacts their buoyant density, size and/or refractive index (RI), which may have consequences for down‐stream EV analysis and EV biomarker profiling