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In the present work, the effect of low aluminum additions and the hot forging process on the microstructure and non-metallic inclusions of high manganese steels is analyzed. Four high-manganese steels (HMnS) were prepared by adding low aluminum contents of 1.1 and 1.5 wt. % to four carbon austenitic steels with medium carbon content (0.3 - 0.4 wt% C) and manganese contents of 17 and 22 wt. Samples of the as-cast steels were hot forged to 1100°C to obtain an overall reduction of 70 %. Microstructural evolution was studied using microscopy techniques (OM, and SEM-EDS) and X-ray diffraction measurements for the as-cast and hot forged steels. A typical grain columnar zone formed during solidification of a cast ingot was obtained in the as-cast condition, where the microstructure consisted of nonmetallic inclusions in a fully austenitic matrix. The non-metallic inclusions were identified as Al2O3 and MnS particles. Thermomechanical treatment allows the formation of an austenitic microstructure characterized by twins in steels with high manganese content, while an austenitic-martensitic duplex microstructure was obtained in HMnS, which contained the lowest manganese contents. The highest tensile strength values were obtained for 17Mn-1Al steel, which had the smallest grain size and higher content of non-metallic inclusions. The hardness values were similar to those obtained in the as-cast condition.

During the second third of last century, the Orinoco Crocodile (Crocodylus intermedius) underwent a hunting process driven by the demand from the North American, European, and Japanese leather industry, resulting in a sharp decline of its populations. Currently, only two known remaining populations of this Critically Endangered species persist in the Colombian Orinoquía: in the Guayabero-Duda-Lozada and the Cravo Norte-Ele-Lipa River Systems. The latter has been the only population subject of study, including recent surveys and local conservation initiatives such as egg and hatchling ranching. Despite suggestions for population recovery based on the observed increase in clutches in the area, information regarding its genetic status has been pending assessment. This research aims to provide a genetic characterization of this remaining population and to evaluate the diversity recovered during a period of the egg ranching initiative. For this purpose, we utilized variable molecular markers, specifically 17 microsatellite loci, nuclear DNA. Despite revealing intermediate levels of genetic diversity, we identified an effective population size of 11.5-17, well below the minimum values proposed for short-term subsistence. While no evidence of inbreeding was found, it is acknowledged as a potential risk based on the population's history. Additionally, we detected a historical bottleneck possibly influenced by arid periods affecting the region since the Pleistocene. While the evaluated population presents a unique opportunity for C. intermedius conservation, it also exposes a high risk of entering the extinction vortex. The primary action to be taken is to support the egg and hatchling ranching program, which successfully recovered most of the genetic diversity present in the population., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Castillo-Rodríguez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Morphological traits from blood stages have been the gold standard for determining haemosporidian parasite species. However, the status of some taxa and the value of such traits in parasites from reptiles remain contentious. The scarce sampling of these species worsens the situation, and several taxa lack molecular data. A survey was performed in the Magdalena Department in Colombia, where 16 species of reptiles were captured. A peculiar haemosporidian parasite was found in the Turnip-tailed gecko Thecadactylus rapicauda . This haemosporidian does not show malarial pigment in blood stages under light microscopy; thus, it fits the Garnia genus's characters belonging to the Garniidae . However, the phylogenetic analyses using a partial sequence of cytochrome b and the mitochondrial DNA placed it within the Plasmodium clade. Our findings suggest that many putative Garnia species belong to the genus Plasmodium , like the one reported here. This study either shows that visible malarial pigment in blood stages is not a diagnostic trait of the genus Plasmodium or malarial pigment might be present in an undetectable form under a light microscope. In any case, the current taxonomy of haemosporidian parasites in reptiles requires revision. This study highlights the importance of using molecular and morphological traits to address taxonomic questions at the species and genus levels in haemosporidian parasites from reptiles.

Haemogregarines (Adeleorina) have a high prevalence in turtles. Nevertheless, there is only one Hepatozoon species described that infects Testudines so far; it is Hepatozoon fitzsimonsi which infects the African tortoise Kinixys belliana. Colombia harbours a great diversity of chelonians; however, most of them are threatened. It is important to identify and characterize chelonian haemoparasite infections to improve the clinical assessments, treatments and the conservation and reintroduction programs of these animals. To evaluate such infections for the Colombian wood turtle Rhinoclemmys melanosterna, we analysed blood from 70 individuals. By using the morphological characteristics of blood stages as well as molecular information (18S rRNA sequences), here we report a new Hepatozoon species that represents the first report of a hepatozoid species infecting a semi-aquatic continental turtle in the world. Although the isolated lineage clusters within the phylogenetic clades that have morphological species of parasites already determined, their low nodal support makes their position within each group inconclusive. It is important to identify new molecular markers to improve parasite species identification. In-depth research on blood parasites infecting turtles is essential for increasing knowledge that could assess this potential unknown threat, to inform the conservation of turtles and for increasing the state of knowledge on parasites.

Thirteen species of Neotropical bats of the genus Micronycteris are currently recognized and are allocated to four subgenera Leuconycteris , Micronycteris , Schizonycteris , and Xenonectes . Despite that, the presence of polyphyletic clades in molecular phylogenies suggests that its diversity is underestimated. Additionally, the incorrect identification of some genetic sequences, the incorrect assignation of available valid names, and restricted geographic sampling have biased the identification of independently evolutionary lineages within Micronycteris . In this study, several unknown genealogical lineages in the genus are identified and an updated phylogenetic hypothesis is proposed using mitochondrial and nuclear DNA fragments. The phylogenetic analyses congruently showed all individuals in four well-supported subgenera, but M. schmidtorum was revealed as the sister taxon of M. brosseti in the subgenus Leuconycteris. Twenty-seven different genealogical lineages were identified. These included eight confirmed species: M. brosseti , M. buriri , M. giovanniae , M. matses , M. schmidtorum , M. simmonsae , M. tresamici , and M. yatesi . Nineteen either allopatric or parapatric candidate species were also confirmed, two within the M. hirsuta complex, nine within the M. megalotis complex, seven within the M. minuta complex, and one corresponding to " M. sp.". These results revealed an extensive undescribed diversity within each subgenus of Micronycteris . Nevertheless, the evolutionary processes associated with the specific radiations are poorly understood. This is just the beginning of the assessment of the taxonomy and systematics of Micronycteris , which requires additional integrative taxonomical approaches for its advance., (Darwin M. Morales-Martínez, Hugo F. López-Arévalo, Mario Vargas-Ramírez.)

A new species of Pristimantis (Craugastoridae, subgenus Pristimantis) is described from a relict and unexplored cloud forest in the western slope from Cordillera Oriental of the Colombian Andes. The specific name was chosen by consensus expert scientists and local people. Pristimantis chamezensis sp. nov. is easily distinguished from congeneric species by having a gray iris with black reticulations in life, subconical tubercles on the upper eyelid, the chin edged with irregular, dark-brown blotches, and conical heel tubercles. The phylogenetic analyses suggest that the origin and radiation of its clade may have occurred in the highlands. With the description of P. chamezensis sp. nov. , we identify 14 species distributed throughout the eastern slope of the Andes that are associated with the Orinoco Basin., (Andrés R. Acosta-Galvis, Ana M. Saldarriaga-Gómez, Beatriz Ramírez, Mario Vargas-Ramírez.)

The genus Haemocystidium was described in 1904 by Castellani and Willey. However, several studies considered it a synonym of the genera Plasmodium or Haemoproteus . Recently, molecular evidence has shown the existence of a monophyletic group that corresponds to the genus Haemocystidium . Here, we further explore the clade Haemocystidium spp. by studying parasites from Testudines. A total of 193 individuals belonging to six families of Testudines were analyzed. The samples were collected in five localities in Colombia: Casanare, Vichada, Arauca, Antioquia, and Córdoba. From each individual, a blood sample was taken for molecular analysis, and peripheral blood smears were made, which were fixed and subsequently stained with Giemsa. The prevalence of Haemocystidium spp. was 1.55% (n = 3/193); all infected individuals belonged to Podocnemis vogli (Savanna Side-necked turtle) from the department of Vichada. This is the first report of Haemocystidium spp. in Colombia and in this turtle species. The phylogenetic analysis of a mitochondrial c ytb fragment revealed Haemocystidium spp. as a monophyletic group and as a sister taxon of Haemoproteus catharti and the genus Plasmodium . Haemocystidium spp. are difficult to identify by morphology only. As a result, it is possible that some of the taxa, such as Haemocystidium ( Simondia ) pacayae , represent a species complex. The parasite found in our study is morphologically indistinguishable from Haemocystidium ( Simondia ) pacayae reported in Peru. However, the new lineage found in P. vogli shows a genetic distance of 0.02 with Hae. pacayae and 0.04 with Hae. peltocephali . It is proposed that this divergent lineage might be a new species. Nevertheless, additional molecular markers and ecological features could support this hypothesis in the future., Competing Interests: The authors declare that they have no conflict of interest., (© 2019 The Authors.)

In this paper we report the synthesis of a new polyacrylate named poly(1,1'-BP4MA) which is a derivate from 4-biphenylmethanol monomer. Poly(1,1'-BP4MA) was obtained by solution and bulk polymerization techniques to yield polymers with high molecular weight and high solubility. The study of the optical properties showed that poly(1,1'-BP4MA) is a fluorescent material with emission in the UV-green region and it has similar quantum yield to tryptophan.