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RESUMEN El conocimiento del desarrollo embrionario y fetal es de suma importancia para poder establecer parámetros de desarrollo normal, la salud del feto y para identificar periodos críticos en la curva de crecimiento. Uno de estos procesos es el patrón de osificación. El presente estudio describe el patrón de osificación en embriones y fetos de alpaca utilizando las técnicas de radiología y diafanización. Se utilizaron 17 alpacas hembra preñadas para la colección de embriones y fetos de variada edad (32, 45, 60, 90, 118, 150, 165, 190, 220 y 280 días). Los especímenes fueron pesados, medidos y radiografiados, y posteriormente fijados en formol tamponado al 10% para ser sometidos al proceso de diafanización en hidróxido de potasio y finalmente teñidos con Rojo de Alizarina. La descripción de los especímenes indica que en embriones de 32 y 45 días no existen estructuras mineralizadas; sin embargo, se pueden ver estructuras radiopacas e indicios de mineralización a los 60 días, indicando que la osificación se estaría iniciando entre los 45 y 60 días de gestación. Los huesos del cráneo y de la caja torácica son los primeros en osificarse. La osificación se presenta de manera consecutiva en la columna vertebral, miembros torácicos y pélvicos, llegando a un estado avanzado de osificación en el último tercio de gestación. ABSTRACT Knowledge of embryonic and foetal development is extremely important in order to establish normal development parameters, the health of the foetus, and to identify critical periods in the growth curve. One of these processes is the pattern of ossification. The present study describes the ossification pattern in alpaca embryos and foetuses using radiology and diaphanization techniques. Seventeen pregnant female alpacas were used for the collection of embryos and foetuses of various ages (32, 45, 60, 90, 118, 150, 165, 190, 220 and 280 days). The specimens were weighed, measured and radiographed, and later fixed in 10% buffered formalin to be subjected to the diaphanization process in potassium hydroxide and finally stained with Alizarin Red. The description of the specimens indicates that in embryos of 32 and 45 days there are no mineralized structures; however, it can be seen radiopaque structures and signs of mineralization at 60 days, indicating that ossification would be starting between 45 and 60 days of gestation. The bones of the skull and the rib cage are the first to ossify. Ossification occurs consecutively in the vertebral column, thoracic and pelvic limbs, reaching an advanced state of ossification in the last third of gestation.

RESUMEN Se han descrito áreas alopécicas en la zona lateral y medial del metatarso de los camélidos sudamericanos, y se les ha denominado «glándulas metatarsales», análogas a las presentes en los cérvidos. En este estudio, se colectaron muestras de tejido de la región metatarsal de 8 especímenes (6 alpacas adultas y dos fetos [5 y 8 meses]) en el camal de Sicuani, Cusco (Perú), y fueron fijadas en formol tamponado al 10% y procesadas mediante la técnica histológica estándar. Seis muestras fueron teñidas con Hematoxilina-Eosina, PAS y Tricrómico de Golden Masson, y fueron evaluadas posteriormente mediante microscopía de campo claro, y dos muestras de alpacas adultas fueron procesadas mediante corte por congelación con un criostato y posterior tinción lipídica diferencial con rojo Nilo y contraste nuclear con Hoescht 33342, evaluándose mediante microscopio de fluorescencia. Se observó un tejido epidérmico alto, conformado por células principales del tipo lipoqueratinocitos, con presencia de vacuolas de contenido lipídico (rojo Nilo). La epidermis presenta proyecciones columnares que se acercan hacia la superficie epidérmica, sirviendo de tejido de sostén y nutricio al contener capilares y presencia de fibras colágenas; la lámina basal de la epidermis presenta papilas que dan origen a dichas proyecciones. En las muestras fetales se observa la misma estructura, pero con menor altura, además de presentarse la membrana epidermal descrita en fetos de camélidos. Se concluye que estas estructuras no son compatibles con tejido glandular al no presentar acinos glandulares ni conductos secretores, determinándose como un epitelio glandular modificado con secreción de naturaleza sebáceo - lipídica. ABSTRACT Alopecic areas have been described in the lateral and medial area of the metatarsus of South American camelids, and have been called «metatarsal glands», analogous to those present in cervids. In this study, tissue samples were collected from the metatarsal region of 8 specimens (6 adult alpacas and two foetuses [5 and 8 months]) in the slaughterhouse of Sicuani, Cusco (Peru), and were fixed in 10% buffered formalin and processed by the standard histological technique. Six samples were stained with Hematoxylin-Eosin, PAS and Golden Masson’s Trichrome, and were subsequently evaluated by brightfield microscopy, and two samples of adult alpacas were processed by freezing cutting with a cryostat and subsequent differential lipid staining with Nile red and nuclear contrast with Hoecht 33342 and evaluated by fluorescence microscopy. A high epidermal tissue was observed, made up of main cells of the lipokeratinocyte type, with the presence of vacuoles with lipid content (Nile red). The epidermis presents columnar projections that approach the epidermal surface, serving as supportive and nutritious tissue as it contains capillaries and collagen fibres; the basal lamina of the epidermis has papillae that give rise to these projections. In the foetal samples the same structure is observed, but with less height, in addition to presenting the epidermal membrane described in camelid foetuses. It is concluded that these structures are not compatible with glandular tissue as they do not present glandular acini or secretory ducts, being determined as a modified glandular epithelium with sebaceous-lipid secretion.

We study lepton flavor violation (LFV) within the Littlest Higgs Model with T parity (LHT) realizing an inverse seesaw (ISS) mechanism of type I. In this scenario there appear new $\mathcal{O}$(TeV) Majorana neutrinos, driving LFV. We are analyzing the heavy Majorana neutrinos effects on LFV processes: $\ell \to \ell' \gamma$, $Z \to \bar{\ell}\ell'$, $L \to 3 \ell$ decays and $\mu \to e$ conversion in nuclei but we emphasize Type III decay channel of $L \to 3 \ell$ which are known as "wrong-sign": $\ell \rightarrow \ell' \ell'' \Bar{\ell}'''$ satisfying $\ell \neq \ell' = \ell'' \neq \ell'''$, since these processes vanish in the traditional LHT. First, we get values to $| \theta_{ej} \theta^{\dagger}_{\mu j}|$, $| \theta_{ej} \theta^{\dagger}_{\tau j}|$, and $| \theta_{\mu j} \theta^{\dagger}_{\tau j}|$ through $\ell \to \ell' \gamma$. With aid of these limits for mixing matrices, we can demonstrate that results for branching ratios of wrong sign processes yield within one order of magnitude below present bounds. We do not expect large correlations among the two wrong-sign decay modes. Also, we see that the mean values of heavy Majorana neutrino masses for all LFV processes are quasi-degenerate around 4 TeV.

[Background]: Ticks are obligate hematophagous arthropods that synthesize the glycan Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) associated with the alpha-gal syndrome (AGS) or allergy to mammalian meat consumption., [Research design and methods]: In this study, we used a proteomics approach to characterize tick proteins in salivary glands (sialome SG), secreted saliva (sialome SA) and with α-Gal modification (alphagalactome SG and SA) in model tick species associated with the AGS in the United States (Amblyomma americanum) and Australia (Ixodes holocyclus). Selected proteins reactive to sera (IgE) from patients with AGS were identified to advance in the identification of possible proteins associated with the AGS. For comparative analysis, the α-Gal content was measured in various tick species., [Results]: The results confirmed that ticks produce proteins with α-Gal modifications and secreted into saliva during feeding. Proteins identified in tick alphagalactome SA by sera from patients with severe AGS symptomatology may constitute candidate disease biomarkers., [Conclusions]: The results support the presence of tick-derived proteins with α-Gal modifications in the saliva with potential implications in AGS and other disorders and protective capacity against tick infestations and pathogen infection. Future research should focus on the characterization of the function of tick glycoproteins with α-Gal in tick biology and AGS., This work was supported by the State Research Agency, Spain, project BIOGAL [PID2020-116761GB-I00], the Spanish Research Council Grant [2020AEP123] and Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). Ixodes holocyclus saliva and salivary gland collections was supported by the Australian Research Council Linkage Grant [LP120200836 (2013-2018)]. MV was supported by the University of Castilla La Mancha, UCLM, Spain, and the Fondo Europeo de Desarrollo Regional, FEDER, EU.

Ticks are arthropod ectoparasites and vectors of pathogens affecting human and animal health worldwide. The exoskeleton is a structure that protect arthropods from natural threats such as predators and diseases. Both structural proteins and chemical elements are components of the exoskeleton. However, the chemical composition and effect of pathogen infection on tick exoskeleton properties has not been characterized. In this study, we characterized the chemical composition of tick exoskeleton and the effect of Anaplasma pathogen infection on the chemical elements of the exoskeleton and selected structural proteins. The chemical composition was characterized ventral, dorsal upper and dorsal lower regions of tick exoskeleton by scanning electron microscopy and energy dispersive spectroscopy and compared between infected and uninfected ticks. The levels of selected structural proteins were analyzed in infected and uninfected I. scapularis salivary glands by immunofluorescence analysis. The results showed that tick exoskeleton contains chemical elements also found in other arthropods. Some of the identified elements such as Mg and Al may be involved in tick exoskeleton stabilization through biomineralization of structural proteins that may be overrepresented in response to pathogen infection. These results suggested that pathogen infection alters the chemical composition of tick exoskeleton by mechanisms still to be characterized and with tick species and exoskeleton region-specific differences., This research was partially supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185).

This article belongs to the Special Issue Zebrafish as a Powerful Tool for Drug Discovery 2021., Mycobacteriosis affects wild fish and aquaculture worldwide, and alternatives to antibiotics are needed for an effective and environmentally sound control of infectious diseases. Probiotics have shown beneficial effects on fish growth, nutrient metabolism, immune responses, disease prevention and control, and gut microbiota with higher water quality. However, the identification and characterization of the molecules and mechanisms associated with probiotics is a challenge that requires investigation. To address this challenge, herein we used the zebrafish model for the study of the efficacy and mechanisms of probiotic interventions against tuberculosis. First, bacteria from fish gut microbiota were identified with high content of the surface glycotope Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) that has been shown to induce protective immune responses. The results showed that probiotics of selected bacteria with high α-Gal content, namely Aeromonas veronii and Pseudomonas entomophila, were biosafe and effective for the control of Mycobacterium marinum. Protective mechanisms regulating immunity and metabolism activated in response to α-Gal and probiotics with high α-Gal content included modification of gut microbiota composition, B-cell maturation, anti-α-Gal antibodies-mediated control of mycobacteria, induced innate immune responses, beneficial effects on nutrient metabolism and reduced oxidative stress. These results support the potential of probiotics with high α-Gal content for the control of fish mycobacteriosis and suggested the possibility of exploring the development of combined probiotic treatments alone and in combination with α-Gal for the control of infectious diseases., This research was funded by Junta de Comunidades de Castilla-La Mancha (JCCM), Spain, and EU-FEDER (grant GALINFEC SBPLY/17/180501/000185). MC was funded by the Ministerio de Ciencia, Innovación y Universidades, Spain (grant FJC-2018-038277-I).

Rhipicephalus spp. (Acari: Ixodidae) ticks are obligate hematophagous arthropods, which constitute a model for the study of vector-host interactions. The chemical composition or elementome of salivary glands (SG) and cement provides information relevant for the study of protein-based complex multifunctional tissues with a key role in tick biology. In this study, we characterized the elementome of cement cones in Rhipicephalus sanguineus collected from naturally infested dogs and in SG and cement of R. bursa collected from experimentally infested rabbits at different feeding stages. The elementome was characterized using scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS). The results showed the identification of up to 14 chemical elements in the cement, and suggested tick/host-driven differences in the cement elementome between tick species and between SG and cement within the same species. By still unknown mechanisms, ticks may regulate cement elementome during feeding to affect various biological processes. Although these analyses are preliminary, the results suggested that N is a key component of the cement elementome with a likely origin in SG/salivary proteins (i.e., Glycine (C2H5NO2)-rich superfamily member proteins; GRPs) and other tick/host-derived components (i.e. NAPDH). Future research should be focused on tick elementome and its functional implications to better understand cement structure and function., This work was supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185), and partially funded by Fundação para a Ciênciae Tecnologia (FCT) under the project PTDC/CVT-CVT/29073/2017 (UID/Multi/04413/2013). Margarita Villar was supported by the University of Castilla La 309 Mancha, UCLM, Spain, and the Fondo Europeo de Desarrollo Regional, FEDER, EU.

Humans evolved by losing the capacity to synthesize the glycan Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal), which resulted in the capacity to develop a protective response mediated by anti-α-Gal IgM/IgG antibodies against pathogens containing this modification on membrane proteins. As an evolutionary trade-off, humans can develop the alpha-Gal syndrome (AGS), a recently diagnosed disease mainly associated with allergic reactions to mammalian meat consumption. The etiology of the AGS is the exposure to tick bites and the IgE antibody response against α-Gal-containing glycoproteins and glycolipids. The objective of this study was to characterize the anti-α-Gal antibody response in association with the immune-mediated peripheral neuropathy, Guillain-Barré syndrome (GBS), and compare it with different factors known to modulate the antibody response to α-Gal such as exposure to tick bites and development of allergic reactions in response to tick bites. The results showed a significant decrease in the IgM/IgG response to α-Gal in GBS patients when compared to healthy individuals. In contrast, the IgM/IgG levels to α-Gal did not change in patients with allergic reactions to tick bites. The IgE response was not affected in GBS patients, but as expected, the IgE levels significantly increased in individuals exposed to tick bites and patients with tick-associated allergies. These results suggest that the immune pathways of anti-α-Gal IgM/IgG and IgE production are independent. Further studies should consider the susceptibility to allergic reactions to tick bites in GBS patients., This work was supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). MV was supported by the University of Castilla La Mancha (UCLM, Spain) and the Fondo Europeo de Desarrollo Regional, FEDER, EU. IGFM was supported by the UCLM. MC was funded by the Ministerio de Ciencia, Innovación y Universidades, Spain (grant FJC-2018-038277-I).

The α-Gal syndrome (AGS) is a type of allergy characterized by an IgE antibody response against the carbohydrate Galα1-3Galβ1-4GlcNAc-R (α-Gal). Tick bites are recognized as the most important cause of anti-α-Gal IgE antibody increase in humans. Several risk factors have been associated with the development of AGS, but their integration into a standardized disease diagnosis has proven challenging., This paper was partially funded by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185).

The alpha-Gal syndrome (AGS) is associated with tick bites that can induce in humans high levels of IgE antibodies against the carbohydrate Gal&alpha, 1-3Gal&beta, 1-(3)4GlcNAc-R (&alpha, Gal) present in glycoproteins and glycolipids from tick saliva that mediate primarily delayed anaphylaxis to mammalian meat consumption. It has been proposed that humans evolved by losing the capacity to synthesize &alpha, Gal to increase the protective immune response against pathogens with this modification on their surface. This evolutionary adaptation suggested the possibility of developing vaccines and other interventions to induce the anti-&alpha, Gal IgM/IgG protective response against pathogen infection and multiplication. However, the protective effect of the anti-&alpha, Gal immune response for the control of tuberculosis caused by Mycobacterium spp. has not been explored. To address the possibility of using vaccination with &alpha, Gal for the control of tuberculosis, in this study, we used the zebrafish-Mycobacterium marinum model. The results showed that vaccination with &alpha, Gal protected against mycobacteriosis in the zebrafish model of tuberculosis and provided evidence on the protective mechanisms in response to vaccination with &alpha, Gal. These mechanisms included B-cell maturation, antibody-mediated opsonization of mycobacteria, Fc-receptor (FcR)-mediated phagocytosis, macrophage response, interference with the &alpha, Gal antagonistic effect of the toll-like receptor 2 (TLR2)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB)-mediated immune response, and upregulation of pro-inflammatory cytokines. These results provided additional evidence supporting the role of the &alpha, Gal-induced immune response in the control of infections caused by pathogens with this modification on their surface and the possibility of using this approach for the control of multiple infectious diseases.

This article belongs to the Special Issue Ectoparasite Biogenic Components in the Modulation of Vector-host-pathogen Interactions., Ticks are obligate hematophagous arthropods and vectors of pathogens affecting human and animal health worldwide. Cement is a complex protein polymerization substance secreted by ticks with antimicrobial properties and a possible role in host attachment, sealing the feeding lesion, facilitating feeding and pathogen transmission, and protection from host immune and inflammatory responses. The biochemical properties of tick cement during feeding have not been fully characterized. In this study, we characterized the proteome of Rhipicephalus microplus salivary glands (sialome) and cement (cementome) together with their physicochemical properties at different adult female parasitic stages. The results showed the combination of tick and host derived proteins and other biomolecules such as α-Gal in cement composition, which varied during the feeding process. We propose that these compounds may synergize in cement formation, solidification and maintenance to facilitate attachment, feeding, interference with host immune response and detachment. These results advanced our knowledge of the complex tick cement composition and suggested that tick and host derived compounds modulate cement properties throughout tick feeding., This research was funded by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). M.V. was supported by the University of Castilla La Mancha, UCLM, Spain, and the Fondo Europeo de Desarrollo Regional, FEDER, EU. I.G.F.M. was supported by the University of Castilla La Mancha, UCLM, Spain.

The molecular interactions between hosts, vectors and pathogens drive the etiology of infectious diseases. At first sight, the Guillain-Barré and Alpha-Gal syndromes have quite different etiologies but, as proposed here, a closer look into the immune response to galactose-containing oligosaccharide structures that characterizes these two diseases reveals striking commonalities. In this Opinion paper, we address the main molecular drivers of two apparently unrelated diseases, and how the characterization of the immune response and immunological tolerance would advance the control and prevention of these diseases., This study was funded by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). M.V. was supported by the University of Castilla La Mancha, Spain.

Humans evolved by losing the capacity to synthesize the glycan Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal), which resulted in the development of a protective response mediated by anti-α-Gal IgM/IgG/IgA antibodies against pathogens containing this modification on membrane proteins. As an evolutionary trade-off, humans can develop the alpha-Gal syndrome (AGS), a recently diagnosed disease mediated by anti-α-Gal IgE antibodies and associated with allergic reactions to mammalian meat consumption and tick bites. However, the anti-α-Gal antibody response may be associated with other immune-mediated disorders such as those occurring in patients with COVID-19 and Guillain-Barré syndrome (GBS). Here, we provide a dataset (209 entries) on the IgE/IgM/IgG/IgA anti-α-Gal antibody response in healthy individuals and patients diagnosed with AGS, tick-borne allergies, GBS and COVID-19. The data allows correlative analyses of the anti-α-Gal antibody response with factors such as patient and clinical characteristics, record of tick bites, blood group, age and sex. These analyses could provide insights into the role of anti-α-Gal antibody response in disease symptomatology and possible protective mechanisms.

Objectives. To interpret the motives of pregnancy in girls and the re-signification of their life’s course. Materials and methods. In the cities of Bogota, Cali, Cartagena and Medellin, 18 life stories of adolescents under 15 years old with experience of pregnancy were made during 2012 and 2013. A phenomenological analytical framework was used to reveal the motives and meanings. Results. The “because motives” and “in order to motives” of adolescents life course, are redefined by the moral control of families, couples, education and health professionals based on common sense and professional habitus. Conclusion. In the real “because motives” it is found that common sense assigns blame and responsibility to teens for their pregnancy. In the educational context there is a device that excludes them and promotes dropouts. In the field of health, human rights abuses are used as a control and punishment mechanism.

La vicuña es una especie emblemática de la conservación de fauna en el Perú. La población de vicuñas se recuperó después de varios años de medidas oportunas para su conservación, pasando al apéndice II del CITES. En la actualidad existen vicuñas que se mantienen libres (silvestría) y poblaciones mantenidas encerradas en cercos permanentes (cautiverio). Durante 2018 se realizaron 58 capturas programadas (llamadas Chacus) en la Región Cusco, capturando 6777 animales, correspondiendo 3229 y 3548 cabezas para silvestría y cautividad, respectivamente. La distribución etaria en el caso de juveniles fue mayor en silvestría (18.08%) con respecto al sistema de cautividad (7.2%), lo cual estaría evidenciando la existencia de mayor mortalidad en esta población. El censo nacional de 2012 indica una mayor proporción de hembras en la población general de la Región Cusco; sin embargo, en este trabajo se encontraron poblaciones similares por sexo en ambos sistemas de crianza. La proporción de vicuñas esquiladas respecto a las capturadas fue de 52.95 y 30.21% para silvestría y cautividad, respectivamente, en tanto que la producción de fibra fue de 172.4 y 156.7 g por animal en promedio para silvestría y cautividad, respectivamente. Estos resultados conllevan a la posibilidad de replantear el uso de cercos permanentes en la crianza de vicuñas en cautiverio para la producción de fibra, considerando los menores niveles productivos obtenidos en este sistema de manejo.

Every day the juridical sociology or sociology of the law gets more importance in the field of law sciences. This importance takes root in the perspectives of analysis that juridical sociology offers to the study of the laws and its relationships with the social phenomena. Nevertheless, as a subjetc of early formation, there is a contrversy about the concept an the object of juridical sociology. From a comparative point of view this article presents the contributions of academicians of Europe and America to those object and concept. Cada día la sociología jurídica o sociología del derecho adquiere mayor importancia en el campo de la ciencias jurídicas, importancia que radica en las perspectivas de análisis que la sociología jurídica ofrece al estudio de la norma jurídica y su relación con los fenómenos sociales, sin embargo, como disciplina de reciente formación, existe una controversia acerca del concepto y objeto de la sociología del derecho. Desde un enfoque comparativo, el artículo presenta los aportes realizados por académicos de Europa y América relativos al concepto y objeto de la sociología del derecho.

Objectives. To interpret the motives of pregnancy in girls and the re-signification of their life’s course. Materials and methods. In the cities of Bogota, Cali, Cartagena and Medellin, 18 life stories of adolescents under 15 years old with experience of pregnancy were made during 2012 and 2013. A phenomenological analytical framework was used to reveal the motives and meanings. Results. The “because motives” and “in order to motives” of adolescents life course, are redefined by the moral control of families, couples, education and health professionals based on common sense and professional habitus. Conclusion. In the real “because motives” it is found that common sense assigns blame and responsibility to teens for their pregnancy. In the educational context there is a device that excludes them and promotes dropouts. In the field of health, human rights abuses are used as a control and punishment mechanism.

This paper reviews compliance with the right to health in Colombia following the reform of the Colombian health system in 1993. A case study in the department of Nariño shows the differential effects of war on the guarantee of the right to health of Colombians. The poorest, most vulnerable populations are affected by war and suffer the greatest violation of their right to health. Violations of human rights, including the right to health, are greatest among poor homes, ethnic groups, sexual minorities and all those living in areas where war is at its most intense. Moreover, the social security health care system’s philosophy and organization have enabled illegal armed agents, mainly the paramilitary, to appropriate and manage health resources and use them for their own ends.

OBJETIVOS: Describir y comprender los significados que tiene la sexualidad en los adolescentes , y cómo se construyen e influyen en sus prácticas sexuales y salud reproductiva. MATERIAL Y MÉTODOS: La investigación se llevó a cabo en tres zonas de la ciudad de Bogotá. Se seleccionaron 20 grupos focales y se tomaron 20 relatos de vida de adolescentes mujeres y varones entre 10 y 14 años. Mediante la categorización deductiva e inductiva de las transcripciones de los discursos verbales, se procedió a un análisis de tipo interpretativo para generar conceptos y relaciones que configuran hipótesis plausibles sobre las significaciones que circulan en el universo simbólico adolescente. RESULTADOS: Existen diferencias en los significados que tienen los varones y las mujeres sobre la sexualidad, la forma en que los construyen y los agentes que contribuyen a su conformación. Estos hallazgos suponen articulaciones distintas en relación con los riesgos en salud sexual y reproductiva CONCLUSIONES: La construcción cultural que se hace de la diferencia sexual -el género- marca los significados que se dan a la sexualidad en los grupos estudiados y establece formas de interactuar con su entorno social. Las mujeres relacionan la sexualidad con el ejercicio reproductivo y la viven como una experiencia negativa. Para los varones existe la posibilidad positiva y placentera de la sexualidad, enmarcada en un contexto que los impulsa a tener relaciones sexuales como forma de sustentar su masculinidad.OBJECTIVE: To describe and understand the meanings that adolescents give to sexuality and how they are created and influence adolescents' reproductive health and sexual practices. MATERIAL AND METHODS: The research was conducted in three different regions within Bogotá city. Twenty focus groups were selected and 20 life stories of boys and girls between 10 and 14 years old were transcribed. From inductive and deductive categorization of the transcripts of the oral histories, an interpretative analysis was carried out in order to generate concepts and relations that comprise plausible hypotheses about the meanings that circulate in the adolescents' symbolic universe. RESULTS: There are notable differences between the meanings that boys and girls give to sexuality, the ways in which such meanings are created, and the factors that contribute to its configuration. These findings imply dissimilar constructions related with reproductive and sexual health risks. CONCLUSIONS: The cultural constructions resulting from sexual differences that is, gender suggest the meanings that are given to sexuality in the groups studied and define ways of interacting with the social environment. Girls relate sexuality with reproduction and they experience it as negative. For boys, the possibility of a positive and pleasant experience of sexuality exists, marked by a context that encourages having sexual relations as a way of maintaining manhood.

El embarazo adolescente tiene un alto impacto socioeconómico. El objetivo de esta investigaciónfue interpretar los significados de la sexualidad y el embarazo de niñas menores de 15 añoscon experiencia de embarazo. Se realizó un estudio cualitativo interpretativo desde el enfoquefenomenológico de Alfred Schütz sobre el sentido común. Se realizaron 18 relatos de vidacon adolescentes menores de 15 años con experiencia de embarazo en las ciudades de Bogotá,Cali, Cartagena y Medellín. Los significados de la menarquia, el inicio de relaciones sexuales,la unión en pareja, el uso de anticonceptivos y la atención del parto están influenciados por laagencia moral social e institucional. La empresa moral circula por los espacios de socializaciónde las adolescentes: madres, padres, hogares, instituciones y profesionales del sector de la saludy educativo clasifican, de acuerdo con su sentido común, lo que está bien o es “normal” paralas niñas adolescentes.

To interpret the motives of pregnancy in girls and the re-signification of their life's course.In the cities of Bogota, Cali, Cartagena and Medellin, 18 life stories of adolescents under 15 years old with experience of pregnancy were made during 2012 and 2013. A phenomenological analytical framework was used to reveal the motives and meanings.The "because motives" and "in order to motives" of adolescents life course, are redefined by the moral control of families, couples, education and health professionals based on common sense and professional habitus.In the real "because motives" it is found that common sense assigns blame and responsibility to teens for their pregnancy. In the educational context there is a device that excludes them and promotes dropouts. In the field of health, human rights abuses are used as a control and punishment mechanism.

Resumen en español: "En la parte sur del Estado de Quintana Roo se encuentra la cuenca del río Hondo. Ésta presenta un gran número de asentamientos humanos, los cuales dependen de la ganadería, la agricultura, la pesca y el turismo. Estas actividades representan un riesgo para el estado de salud de los ecosistemas acuáticos, ya sea por la presencia de contaminantes o por la modificación total o parcial del entorno natural. Con la finalidad de conocer el grado de afectación presente en la cuenca, se realizó un análisis espacial de un índice biótico de integridad (IBI), en función de elementos del paisaje. Se seleccionaron 23 sitios de muestreo, donde se determinaron los porcentajes de cobertura de los diferentes usos del suelo, coberturas y paisajes a varias escalas espaciales de medición (125, 250, 500 y 1000 m) en los distintos estratos de la cuenca (alta, media, baja). Si bien se encontraron correlaciones bajas entre las variables del paisaje y el IBI, se observaron diferencias entre los estratos de la cuenca. Los paisajes con agricultura, asentamientos humanos y vegetación secundaria presentaron relaciones negativas con respecto al IBI, en la cuenca alta y baja, así como las selvas y los pastizales en la cuenca media. Del total de usos, coberturas y paisajes ubicados en la cuenca del río Hondo, los que resultaron ser más perjudiciales para la integridad biótica fueron los de origen antrópico, mientras que los que menos afectaron fueron los de carácter natural, tales como humedales y selvas. Conocer la condición del paisaje puede ser de utilidad para determinar el estado de salud de los ambientes acuáticos en la cuenca del río Hondo. "