68,489 research outputs found

    What is the importance of sperm subpopulations?

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    .The study of sperm subpopulations spans three decades. The origin, meaning, and practical significance, however, are less clear. Current technology for assessing sperm morphology (CASA-Morph) and motility (CASA-Mot) has enabled the accurate evaluation of these features, and there are many options for data classification. Subpopulations could occur as a result of the stage of development of each spermatozoon in the subpopulation. Spermatogenesis might contribute to the production of these subpopulations. Insights from evolutionary biology and recent molecular research are indicative of the diversity among male gametes that could occur from unequal sharing of transcripts and other elements through cytoplasmic bridges between spermatids. Sperm cohorts exiting the gonads would contain different RNA and protein contents, affecting the spermatozoon physiology and associations with the surrounding environmental milieu. Subsequently, these differences could affect how spermatozoa interact with the environmental milieu (maturation, mixing with seminal plasma, and interacting with the environmental milieu, or female genital tract and female gamete). The emergence of sperm subpopulations as an outcome of evolution, related to the reproductive strategies of the species, genital tract structures, and copulatory and fertilization processes. This kind of approach in determining the importance of sperm subpopulations in fertilization capacity should have a practical impact for conducting reproductive technologies, inspiring and enabling new ways for the more efficient use of spermatozoa in the medical, animal breeding, and conservation fields. This manuscript is a contribution to the Special Issue in memory of Dr. Duane GarnerS

    A new index of resilience applicable to external pulse-disturbances that considers the recovery of communities in the short term

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    .Resilience is a key concept in the study of the recovery of ecosystems affected by disturbances. Currently, there are numerous indices to measure resilience, but many of them do not show the accuracy of the resilience value or the behaviour of ecological parameters in the face of disturbances. New approaches and technologies enable large amounts of information to be obtained, facilitating the proposal of new resilience indices that work consistently and intuitively for a wide variety of ecological response variables under different scenarios after pulse-disturbances. In this study, we propose and verify a new resilience index, comparing its performance with others previously published. We validated the performance of the new index using real data based on field measurements of changes in soil bacterial OTUs diversity and abundance after a wildfire. The new resilience index provided an automatic and robust functional classification of the behaviour of ecosystems after disturbances, supported by a bootstrap analysis. We identified 5 scenarios of ecosystem resilience performance according to their behaviour after a pulse-disturbance: resilient, non-resilient, recovering, rebound, and continuing.S

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

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    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    Interactive Sonic Environments: Sonic artwork via gameplay experience

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    The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken

    Structural and Attitudinal Barriers to Bicycle Ownership and Cycle-Based Transport in Gauteng, South Africa

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    Policies that aim to facilitate and promote non-motorised transport (NMT), and in particular cycling, have been developed by many high-income countries facing increasingly congested roads and saturated public transport systems. Such policies are also emerging in many low- and middle-income settings where high rates of urbanisation have led to similar problems with motorised transport. The aim of the present study was to better understand the potential structural and attitudinal barriers to cycle-based transport in one such context: South Africa’s Gauteng Province, the industrial powerhouse of sub-Saharan Africa that has recently made a firm commitment to NMT. The study focussed on demographic and socioeconomic variation in bicycle and car ownership, and related this to: (1) the reported use of motorised and non-motorised transport (both private and public); and (2) perceived ‘problems’ with cycling. The analyses drew on interviews with key respondents from n = 27,490 households conducted in 2013 as part of the third Quality of Life survey undertaken by the Gauteng City Regional Observatory. The survey contained items on three outcomes of interest: household vehicle ownership (bicycles and cars); modes of transport used for the “trips” most often made; and respondents’ “single biggest problem with… cycling”. Respondent- and household-level demographic and socioeconomic determinants of these outcomes were examined using descriptive and multivariable statistical analyses, the latter after adjustment for measured potential confounders identified using a theoretical causal path diagram (in the form of a directed acyclic graph). Of the n = 26,469 households providing complete data on all of the variables examined in the present study, only n = 8722 (32.9%) owned a car and fewer still (n = 2244; 8.4%) owned a bicycle. The ownership of these assets was commonest amongst wealthier, economically active households; and those that owned a car had over five times the odds of also owning a bicycle, even after adjustment for potential confounding (OR 5.17; 95% CI 4.58, 5.85). Moreover, of household respondents who reported making ‘trips’ during the preceding month (n = 18,209), over two-thirds of those whose households owned a car (70.1%) reported private car-based transport for such trips, while only 3.2% of those owning a bicycle reported cycling. Amongst the specific responses given to the item requesting the “single biggest problem with… cycling” by far the commonest was “Don’t know how to cycle” (32.2%), less than half as many citing “Vehicle accident risk” (15.9%), and fewer still: “Destination is too far” (13.9%); “Crime” (10.3%); “Too much effort” (9.2%); or “Lack of good paths” (4.6%). While the first of these reasons was commonest amongst poorer households, concerns about risk and effort were both most common amongst better educated, economically active and wealthier/better serviced households. In contrast, concerns over (cycle) paths were only common amongst those owning bicycles. The low prevalence of household bicycle ownership, and the disproportionate number of households owning bicycles that also owned cars, might explain the very small proportion of the ‘the trips most often made’ that involved cycle-based transport (0.3%), and the preferential use of cars amongst households owning both bicycles and cars. Low levels of bicycle ownership might also explain why so many respondents cited “Don’t know how” as the “single biggest problem with… cycling”; although risk and effort were also substantial concerns (presumably for many who did, and some who did not, know how to cycle); the lack of suitable cycle lanes being only primarily a concern for those who actually owned bicycles. Structural and attitudinal barriers to cycle-based transport limit the use of cycle-based transport in Gauteng, not only amongst the vast majority of household respondents who lack the means to cycle (and the means to learn how), but also amongst those dissuaded from learning to cycle, purchasing a bicycle and/or using a bicycle they own by: the risks and effort involved; the lack of suitable cycle paths; and/or because they also own a car and prefer to drive than cycle

    Metodología de intervención para trabajar ODS. Educación a través de las artes

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    La Agenda 2030 presenta 17 Objetivos de Desarrollo Sostenible (ODS), con sus metas e indicadores universales que los países miembros de la ONU emplean para enmarcar sus políticas. Entre las metas del ODS 4 “educación de calidad” encontramos: “asegurar que todos los alumnos adquieran los conocimientos teóricos y prácticos necesarios para promover el desarrollo sostenible, entre otras cosas mediante la educación para el desarrollo sostenible y los estilos de vida sostenibles, los derechos humanos, la igualdad de género, la promoción de una cultura de paz y no violencia, la ciudadanía mundial y la valoración de la diversidad cultural y la contribución de la cultura al desarrollo sostenible”. La educación, se considera el motor de la Agenda 2030 porque, además de representar el centro del ODS 4, desempeña también un papel notable en la implementación de los demás, mejorando su alcance y efectividad. Así pues, entre las disciplinas que sustentan este trabajo se escogió la Educación para el Desarrollo Sostenible y la Ciudadanía Global como marco de acción y punto de partida en la formación de los ciudadanos de un futuro viable, equitativo y habitable. Se continuó investigando las oportunidades del desarrollo de la Competencia Intercultural en las relaciones humanas, aquello que diferencia a unas personas de otras puede aportar al conjunto de la sociedad y cómo la educación permitiría su aprovechamiento. Con todo ello, se planteó el marco didáctico de interacción en el cual se implementó la interculturalidad en el ejercicio educativo. Se estudió así el poder de las artes como medio de motivación e inspiración a la hora de transmitir de la manera más eficaz posible los valores considerados más arriba. El objetivo del presente estudio se centra en demostrar el potencial de las artes para fomentar las competencias comunicativas, sociales, interculturales, emocionales, de ciudadanía y sostenibilidad. Para ello, se ha realizado una investigación aplicada que deriva en una propuesta concreta de intervención con un programa educativo destinado a la enseñanza de lenguas, tanto primera como extranjera, en distintos niveles de la educación formal en Mali y en España, aplicando un método holístico basado en el paradigma interpretativo. A través de la pintura, la literatura y el cine, se plantean una serie de actividades ideadas para crear un entorno educativo integrador, favorecer el empoderamiento del alumnado y promover el pensamiento crítico, la empatía, la resiliencia, la comunicación, la cooperación y la educación intercultural, como competencias esenciales para la consecución de los 17 ODS, la construcción de un mundo transcultural sostenible y el desarrollo de una ciudadanía global preparada para los retos del siglo XXI. En la metodología de este proceso educativo innovador, multidisciplinar, flexible y adaptable, se ha empleado un análisis del proceso de investigación para monitorizarlo adecuadamente (DAFO). Cada una de las propuestas presenta una recogida de datos cualitativos (observación, rúbricas) y cuantitativos (encuestas, entrevistas) y se ofrece un análisis de contraste de los resultados finales. Con todo, se espera facilitar la exigente tarea que supone hacer consciente a la sociedad de base (desde la misma infancia; desde los niveles más bajos de la misma y en todos los niveles de la educación formal) de en qué consisten los ODS y su relevancia para hacer de todas las personas corresponsables directas en su consecución para garantizar un futuro sostenible para toda la ciudadanía global.The 2030 Agenda presents 17 Sustainable Development Goals (SDGs), with their universal targets and indicators that UN member countries use to frame their policies. Among the targets of SDG 4 “quality education,” we find the one that seeks: “to ensure that all students acquire the theoretical and practical knowledge necessary to promote sustainable development, among other things through education for sustainable development and sustainable lifestyles, human rights, gender equality, the promotion of a culture of peace and non-violence, world citizenship and the appreciation of cultural diversity and the contribution of culture to sustainable development”. Education is considered the engine of the 2030 Agenda because, in addition to representing the centre of SDG 4, it also plays a notable role in the implementation of the others, improving their scope and effectiveness. Among the disciplines that support this research, Education for Sustainable Development and Global Citizenship sets the framework for action and represents a starting point in the formation of citizens for a viable, equitable and habitable future. Global citizenship implies human relations and those and intrinsically shaped by culture. Intercultural Education and, more specifically, the development of Intercultural Competence needed to be considered. What differentiates some people from others can contribute to society as a whole and education is the means to explore and understand. For the design of a didactic framework of interaction, the power of the arts was studied as a means of motivation and inspiration when transmitting the values considered above in the most effective way possible. The objective of this study focuses on proving the potential of the arts to promote communicative, social, intercultural, emotional, citizenship and sustainability skills. For this, the theoretical research derived in a concrete intervention proposal with an educational program in language teaching, both first and foreign languages, at different levels of formal education in Mali and Spain, applying a holistic method based on the interpretive paradigm. Through painting, literature and cinema, a series of activities were designed to create an inclusive educational environment, favour the empowerment of students and promote critical thinking, empathy, resilience, communication, cooperation and intercultural education, as essential skills for the achievement of the 17 SDGs, the construction of a sustainable transcultural world and the development of global citizenship prepared for the challenges of the 21st century. In the methodology of this innovative, multidisciplinary, flexible and adaptable educational process, an analysis of the research process has been used to adequately monitor it (SWOT). Each of the proposals presents a collection of qualitative data (observation, rubrics) and quantitative data (surveys, interviews) and contrast analysis of the final results is offered. All in all, it is expected to facilitate the demanding task of making basic society aware (from childhood itself, from its lowest levels and at all levels of formal education) of what the SDGs consist of and their relevance to make all people directly co-responsible in its achievement to guarantee a sustainable future for all global citizens

    Dynamic and Static Cognitive Deficits in Schizophrenia and Bipolar Disorder After the First Episode

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    Abstract Few studies have comprehensively examined the profile of cognitive functioning in first episode psychosis patients throughout the lifespan, and from first episode to chronic stage. We assessed functioning in general and specific cognitive functions, comparing both schizophrenia (N = 64) and bipolar I (N = 19) patients to controls (N = 103). Participants were from a population-based, case-control study of first episode psychosis patients, who were followed prospectively up to 10 years post first admission. A cognitive battery was administered at baseline and follow-up. By combining longitudinal and cross-sectional data, we were able to examine the cognitive profile of patients and controls throughout the entire age range of our sample (16–65). Schizophrenia patients exhibited widespread declines in IQ, executive function, visual memory, language ability, and verbal knowledge. However, the ages at which these declines occurred differed between functions. Deficits in verbal memory, working memory, processing speed, and visuospatial ability, on the other hand, were present at the first episode, and remained relatively static thereafter. Bipolar I patients also showed declines in IQ, verbal knowledge, and language ability, albeit at different ages to schizophrenia patients and only in verbal functions. Deficits on measures of verbal memory, processing speed, and executive function remained relatively static. Thus, both schizophrenia and bipolar I patients experienced cognitive decline in general and specific functions after the first episode, but the age at which these declines occurred differed between disorder and function. Cognitive remediation efforts may be most fruitful when targeting individual functions during specific time periods throughout adulthood

    Conservation agriculture affects grain and nutrient yields of Maize (Zea Mays L.) and can impact food and nutrition security in Sub-Saharan Africa

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    Maize is a major staple and plays an essential role in food and nutrition security in Sub-Saharan Africa (SSA). Conservation agriculture (CA), a climate-smart agriculture practise based on minimum soil disturbance, crop residue retention, and crop diversification, has been widely advocated but without extensive research on the impact it may have on maize nutrient composition, and food and nutrition security. This study assessed the grain yield, macro- and micronutrient mineral content, and nutrient yield of eight maize varieties grown in Malawi, and how these are affected by CA practises over two seasons. The minerals were analysed by inductively coupled plasma (ICP) coupled to optical emission spectroscopy (OES) and to mass spectroscopy (MS). Grain yield and Se content differed among the varieties, while C, N, Fe, K, Mg, Mn, P, and Zn were similar. The local variety Kanjerenjere showed lowest grain and nutrient yields. The open-pollinated varieties (OPVs) concentrated more minerals than the F1 hybrids, but the latter showed higher yields for both grain and nutrients. Typical consumption of the eight maize varieties could fully meet the protein and Mg dietary reference intake (DRIs) of Malawian children (1–3 years), as well as Mg and Mn needs of adult women (19–50 years), but their contribution to dietary requirements was low for Fe (39–41%) and K (13–21%). The trials showed that CA increased grain yield (1.2- to 1.8-fold) and Se content (1.1- to 1.7-fold), but that it had no effect on C, K, Mg, P, and Zn, and that N (1.1- to 1.2-fold), Mn (1.1- to 1.8-fold), and Fe (1.3- to 3.4-fold) were reduced. The high increase in grain yield under CA treatments resulted in increased yields of protein and Se, no effect on the yields of K, Mg, Mn, P, Zn, and reduced Fe yield. Conservation agriculture could contribute in reducing the risk of Se deficiency in Malawian women and children but exacerbates the risk of Fe deficiency. A combination of strategies will be needed to mitigate some of the foreseen effects of climate change on agriculture, and food and nutrition security, and improve nutrient intake

    Strung pieces: on the aesthetics of television fiction series

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    As layered and long works, television fiction series have aesthetic properties that are built over time, bit by bit. This thesis develops a group of concepts that enable the study of these properties, It argues that a series is made of strung pieces, a system of related elements. The text begins by considering this sequential form within the fields of film and television. This opening chapter defines the object and methodology of research, arguing for a non-essentialist distinction between cinema and television and against the adequacy of textual and contextual analyses as approaches to the aesthetics of these shows. It proposes instead that these programmes should be described as televisual works that can be scrutinised through aesthetic analysis. The next chapters propose a sequence of interrelated concepts. The second chapter contends that series are composed of building blocks that can be either units into which series are divided or motifs that unify series and are dispersed across their pans. These blocks are patterned according to four kinds of relations or principles of composition. Repetition and variation are treated in tandem in the third chapter because of their close connection, given that variation emerges from established repetition. Exception and progression are also discussed together in the fourth chapter since they both require a long view of these serial works. The former, in order to be recognised as a deviation from the patterns of repetition and variation. The latter, In order to be understood in Its many dimensions as the series advances. Each of these concepts is further detailed with additional distinctions between types of units, motifs, repetitions, variations, and exceptions, using illustrative examples from numerous shows. In contrast, the section on progression uses a single series as case study, Carnivàle (2003-05), because this is the overarching principle that encompasses all the others. The conclusion considers the findings of the research and suggests avenues for their application

    The empty space in abstract photography: a psychoanalytical perspective

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    The aim of the research that this thesis is based on is to explore the theoretical problems raised by the concept of photographic abstraction. These consist in the tension between the two aspects of the photographic sign, the indexical and iconic, and are examined in the context of the particular exploration of the empty space in abstract photography which I have pursued through my practice. The investigation draws mainly upon the psychoanalytic theory of transitional phenomena as proposed by Winnicott, as well as other art theories (Deleuze & Guattari, Ehrenzweig, Fer, Fuller, Greenberg, Joselit, Kuspit, Leider, Worringer) of abstraction. It explores the relationship of the abstract photographic image to notions of exteriority and interiority as these relate to the transition from the unconscious to conscious reality. The development of this research suggests the psychoanalytical concept of potential space as a contribution to an aesthetic model of abstraction. This concept is employed as a methodological tool in the development of the practical work and creates a framework for its interpretation. The concept of potential space is based on Winnicott's ideas around "playing with the real" in an intermediate area of experience between the internal and external reality, where creativity originates as a zone of fictive play that facilitates the subject's journey from "what is subjectively conceived of' to "what is objectively perceived. " The outcome of this investigation constitutes the production of a series of photographs describing an empty abstract space, one that is invested with a psychic dimension that produces the effect of ambiguity between its representational and abstract readings. It provides a redefinition of abstraction in a space of tension between the iconic and indexical aspects of the sign and opens up the space of abstraction in photography as one in which the relationship between inner and outer reality can be performed and can become a space of action and intervention
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