Computational thinking in high school courses

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Trichoderma viride cellulase induces resistance to the antibiotic pore-forming peptide alamethicin associated with changes in the plasma membrane lipid composition of tobacco BY-2 cells

<p>Abstract</p> <p>Background</p> <p>Alamethicin is a membrane-active peptide isolated from the beneficial root-colonising fungus <it>Trichoderma viride</it>. This peptide can insert into membranes to form voltage-dependent pores. We have previously shown that alamethicin efficiently permeabilises the plasma membrane, mitochondria and plastids of cultured plant cells. In the present investigation, tobacco cells (<it>Nicotiana tabacum </it>L. cv Bright Yellow-2) were pre-treated with elicitors of defence responses to study whether this would affect permeabilisation.</p> <p>Results</p> <p>Oxygen consumption experiments showed that added cellulase, already upon a limited cell wall digestion, induced a cellular resistance to alamethicin permeabilisation. This effect could not be elicited by xylanase or bacterial elicitors such as flg22 or elf18. The induction of alamethicin resistance was independent of novel protein synthesis. Also, the permeabilisation was unaffected by the membrane-depolarising agent FCCP. As judged by lipid analyses, isolated plasma membranes from cellulase-pretreated tobacco cells contained less negatively charged phospholipids (PS and PI), yet higher ratios of membrane lipid fatty acid to sterol and to protein, as compared to control membranes.</p> <p>Conclusion</p> <p>We suggest that altered membrane lipid composition as induced by cellulase activity may render the cells resistant to alamethicin. This induced resistance could reflect a natural process where the plant cells alter their sensitivity to membrane pore-forming agents secreted by <it>Trichoderma spp</it>. to attack other microorganisms, and thus adding to the beneficial effect that <it>Trichoderma </it>has for plant root growth. Furthermore, our data extends previous reports on artificial membranes on the importance of lipid packing and charge for alamethicin permeabilisation to <it>in vivo </it>conditions.</p

Plasma ceramide levels are altered in low and normal birth weight men in response to short-term high-fat overfeeding

AbstractLow birth weight (LBW) individuals have an increased risk of developing insulin resistance and type 2 diabetes compared with normal birth weight (NBW) individuals. We hypothesised that LBW individuals exhibit an increased fatty acid flux into lipogenesis in non-adipose tissue with a resulting accumulation of lipotoxic lipids, including ceramides, in the blood. Therefore, we measured fasting plasma levels of 27 ceramides in 18 young, healthy, LBW men and 25 NBW controls after an isocaloric control diet and a 5-day high-fat, high-calorie diet by HPLC-HRMS. LBW men did not show elevated plasma ceramide levels after the control or high-fat, high-calorie diet. An increased fatty acid oxidation rate in these individuals during both diets may limit ceramide synthesis and thereby compensate for a likely increased fatty acid load to non-adipose tissue. Interestingly, LBW and NBW men decreased d18:0–18:1/d18:1–18:0 and d18:1–24:2/d18:2–24:1 levels and increased the d18:0–24:1a level in response to overfeeding. Plasma d18:0–24:1a and total ceramide levels were positively associated with the fasting blood glucose level and endogenous glucose production after the control diet, and the total ceramide level was in addition positively associated with hepatic insulin resistance. Further studies are needed to determine if lipotoxicity contributes to insulin resistance in LBW individuals.</jats:p

Caring teaching and the complexity of building good relationships as pedagogies for social justice in health and physical education

The Health and Physical Education (HPE) profession has increasingly advocated for caring teacher-student relationships. In this paper, we draw on data from an international research project called ‘EDUHEALTH’ [Education for Equitable Health Outcomes – The Promise of School Health and Physical Education] to explore caring teaching and the complexity of building good relationships as pedagogies for social justice in HPE. The data reported on in this paper were generated through 20 HPE lesson observations and interviews with 13 HPE teachers across schools in Sweden, Norway and New Zealand. In our analysis of the data, we employed Nel Noddings ‘Care Theory’ [(1984. Caring, a feminine approach to ethics & moral education. Berkeley, CA: University of California Press; 1997). Pedagogisk filosofi [Philosophy of education]. Oslo: Ad Notam Gyldendal] to study the constitution of relationships and caring teaching in HPE practice. The findings demonstrate that caring teaching is inevitably built on developing good relationships, and that developing such good relationships is a complex process influenced by three key elements. First, teachers have to develop knowledge about their students on a societal, group and personal level; second, teachers have to reflect on the individual, environmental and relational aspects required for building good relationships; and third, teachers have to implement caring teaching strategies, such as planning, caring actions and doing ‘the little things’. Drawing on Nodding’s care theory, we conclude that pedagogies for social justice are enacted when teachers use their own knowledge and knowledge about the students, together with reflection and caring teaching strategies, to arrange a learning environment that promotes inclusion and equitable outcomes for all students.publishedVersio

School HPE: its mandate, responsibility and role in educating for social cohesion.

In a world of increasing diversity in which many established democracies are now consumed by capitalist individualism and protectionist ideals, a focus on equity and social justice is particularly pertinent. For many years, scholars have proposed that schools have the educational responsibility to prepare children for peaceful living in a heterogeneous society and claimed that health and physical education (HPE) activities at school can enhance interpersonal relations, and social cohesion. This paper explores the definition of social cohesion, as well as theories that support its inclusion in school practices before drawing on observational and interview data from of an international project that reveal how HPE teachers across three different countries teach for social cohesion. In our analysis of the data, we employ Allport’s ‘Contact Theory’ (1954) and Pettigrew’s (1998) extension of this theory to conceptualise and interpret the teaching for social cohesion in HPE practice. Within the overarching theme of teaching for social cohesion we present and discuss five sub-themes as examples of the teachers’ pedagogies: (1) a focus on inclusiveness; (2) the inclusion of culturally inclusive practices; (3) building teacher/student and student/student relationships; (4) planning and structuring activities for students to work together in heterogeneous teams while focusing on cooperation; and (5) focusing on personal and social responsibility by encouraging adherence to the principles of fair play and democratically determined rules. We conclude by stating that HPE should be recognised for its role in creating opportunities for constructive social interaction between students of difference, which can contribute to greater inclusion, social cohesion and ultimately social justice in society.publishedVersio

Aberrant Ganglioside Functions to Underpin Dysregulated Myelination, Insulin Signalling, and Cytokine Expression: Is There a Link and a Room for Therapy?

Gangliosides are molecules widely present in the plasma membranes of mammalian cells, participating in a variety of processes, including protein organization, transmembrane signalling and cell adhesion. Gangliosides are abundant in the grey matter of the brain, where they are critically involved in postnatal neural development and function. The common precursor of the majority of brain gangliosides, GM3, is formed by the sialylation of lactosylceramide, and four derivatives of its a- and b-series, GM1, GD1a, GD1b and GT1b, constitute 95% of all the brain gangliosides. Impairments in ganglioside metabolism due to genetic abnormalities of GM-synthases are associated with severe neurological disorders. Apart from that, the latest genome-wide association and translational studies suggest a role of genes involved in brain ganglioside synthesis in less pervasive psychiatric disorders. Remarkably, the most recent animal studies showed that abnormal ganglioside functions result in dysregulated neuroinflammation, aberrant myelination and altered insulin receptor signalling. At the same time, these molecular features are well established as accompanying developmental psychiatric disorders such as attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). This led us to hypothesize a role of deficient ganglioside function in developmental neuropsychiatric disorders and warrants further gene association clinical studies addressing this question. Here, we critically review the literature to discuss this hypothesis and focus on the recent studies on ST3GAL5-deficient mice. In addition, we elaborate on the therapeutic potential of various anti-inflammatory remedies for treatment of developmental neuropsychiatric conditions related to aberrant ganglioside functions. Keywords: insulin receptor signalling; major brain gangliosides; mice; myelination; neurodevelopmental disorders; neuroinflammatio

Researching social justice and health (in)equality across different school Health and Physical Education contexts in Sweden, Norway and New Zealand

The way school Health and Physical Education (HPE) is conceptualized and taught will impact on its ability to provide equitable outcomes across gender, sexuality, ethnicity, religion and social class. A focus on social justice in HPE is pertinent in times when these ideals are currently under threat from neoliberal globalization. This paper draws on data from the initial year of an international collaboration project called ‘Education for Equitable Health Outcomes – The Promise of School Health and Physical Education’ involving HPE and Physical Education Teacher Education researchers from Sweden, Norway and New Zealand. The data in this paper record the researchers’ presentations and discussions about issues of social justice and health as informed by school visits and interviews with HPE teachers in the three different countries. The analysis of the data is focused on what is addressed in the name of social justice in each of the three countries and how cross-cultural researchers of social justice in HPE interpret different contexts. In order to analyse the data, we draw on Michael Uljens’s concepts of non-affirmative and non-hierarchical education. The findings suggest that researching social justice and health (in)equality across different countries offers both opportunities and challenges when it comes to understanding the enactment of social justice in school and HPE practices. We conclude by drawing on Uljens to assert that the quest for social justice in HPE should focus on further problematizing affirmative and hierarchical educational practices since social justice teaching strategies are enabled and constrained by the contexts in which they are practised.Researching social justice and health (in)equality across different school Health and Physical Education contexts in Sweden, Norway and New ZealandpublishedVersio

Constraints on the formation of carbonates and low‐grade metamorphic phases in the Martian crust as a function of H₂O‐CO₂ fluids

Low‐grade metamorphic hydrous minerals and carbonates occur in various settings on Mars and in Martian meteorites. We present constraints on the stability of prehnite, zeolites, serpentine, and carbonates by modeling the influence of H2O‐CO2 fluids during low‐grade metamorphism in the Martian crust using compositions of a Martian basalt and an ultramafic cumulate. In basaltic compositions with 5 wt% fluid, our models predict prehnite in less oxidized, CO2‐poor conditions (≤0.44 mol kg−1 CO2) on warmer geotherms of 20 °C km−1. At fluid‐saturated conditions, epidote and laumontite are replaced by quartz, calcite, chlorite, and muscovite. In ultramafic compositions with 5 wt% fluid, antigorite (serpentine) is stable at CO2‐poor conditions of ≤0.33 mol kg−1, while talc forms at 0.05–0.56 mol kg−1 CO2. At fluid‐saturated conditions, antigorite is replaced by talc and chlorite, and at higher X(CO2) by magnesite and quartz. Our models therefore suggest that prehnite, zeolites, and serpentine have formed in a CO2‐poor environment on Mars implying that fluids during their formation either did not contain high amounts of CO2 or had degassed CO2. Carbonates and potentially talc would have formed in the presence of a CO2‐bearing fluid and therefore at different alteration stages than for prehnite, zeolites, and serpentine either in the same hydrothermal event during which the fluid composition changed gradually due to cooling and precipitation or by separate and successive alteration events with fluids of different compositions