A facile method for the stain-free visualization of hierarchical structures with electron microscopy

Diblock copolymers form hierarchical morphologies with numerous applications in drug delivery and as nanoreactors. Yet, the visualization of these structures by electron microscopy can be extremely difficult, requiring complex staining techniques with associated health risks and the potential to alter structural morphology. Reported here is the synthesis of diblock copolymers by RAFT containing 3,5-bis(trifluoromethyl)phenyl functionality allowing for facile visualization of their resulting hierarchical structures by TEM with no further sample preparation.P.E.W. thanks the AWE and E.A. thanks Schlumberger for financial support, and J.d.B is grateful for a Marie Curie Intraeuropean Fellowship (project # 273807). This work was also supported by an ERC Starting Investigator Grant (ASPiRe) and a Next Generation Fellowship provided by the Walters-Kundert Foundation.This is the accepted manuscript. The final published version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/pola.27517/abstract

Conservative and disruptive modes of adolescent change in human brain functional connectivity

Adolescent changes in human brain function are not entirely understood. Here, we used multiecho functional MRI (fMRI) to measure developmental change in functional connectivity (FC) of resting-state oscillations between pairs of 330 cortical regions and 16 subcortical regions in 298 healthy adolescents scanned 520 times. Participants were aged 14 to 26 y and were scanned on 1 to 3 occasions at least 6 mo apart. We found 2 distinct modes of age-related change in FC: “conservative” and “disruptive.” Conservative development was characteristic of primary cortex, which was strongly connected at 14 y and became even more connected in the period from 14 to 26 y. Disruptive development was characteristic of association cortex and subcortical regions, where connectivity was remodeled: connections that were weak at 14 y became stronger during adolescence, and connections that were strong at 14 y became weaker. These modes of development were quantified using the maturational index (MI), estimated as Spearman’s correlation between edgewise baseline FC (at 14 y, FC14) and adolescent change in FC (ΔFC14−26), at each region. Disruptive systems (with negative MI) were activated by social cognition and autobiographical memory tasks in prior fMRI data and significantly colocated with prior maps of aerobic glycolysis (AG), AG-related gene expression, postnatal cortical surface expansion, and adolescent shrinkage of cortical thickness. The presence of these 2 modes of development was robust to numerous sensitivity analyses. We conclude that human brain organization is disrupted during adolescence by remodeling of FC between association cortical and subcortical areas

Surviving sepsis: going beyond the guidelines

The Surviving Sepsis Campaign is a global effort to improve the care of patients with severe sepsis and septic shock. The first Surviving Sepsis Campaign Guidelines were published in 2004 with an updated version published in 2008. These guidelines have been endorsed by many professional organizations throughout the world and come regarded as the standard of care for the management of patients with severe sepsis. Unfortunately, most of the recommendations of these guidelines are not evidence-based. Furthermore, the major components of the 6-hour bundle are based on a single-center study whose validity has been recently under increasing scrutiny. This paper reviews the validity of the Surviving Sepsis Campaign 6-hour bundle and provides a more evidence-based approach to the initial resuscitation of patients with severe sepsis

A compilation of data on the radiant emissivity of some materials at high temperatures

This paper gives a compilation of experimental data from a variety of sources of the emissivity of materials used in high temperature applications. The data is given in the form of temperature dependent correlation equations which can be used for modelling purposes. The data on refractory materials show the importance of surface properties, the effect of surface coatings and ways in which these can be taken into account for more accurate predictions of emissivity. Information is also given on chars, ash particles and furnace deposits resulting from the combustion of coal and biomass

Emissions performance of high moisture wood fuels burned in a residential stove

A study has been made of the effect of fuel moisture content on emissions from a wood burning domestic stove. Two fuel types were studied: beech which is a hardwood, and spruce which is a softwood. The moisture contents investigated were for a freshly felled wood, a seasoned wood and a kiln dried wood. The effect of the moisture measurement method was considered using a commercial electrical conductivity probe moisture meter which was compared with laboratory analysis by drying in an oven at 105 °C. It was shown that the probe can significantly underestimate the actual moisture content in certain cases. Correlations were made of the burning rate, the Emission Factors for the formation of gaseous and particulate pollutants as a function of the moisture content. We also studied the ratio of Black Carbon to Total Carbon (BC/TC) to obtain information on the organic content of the particles. The NOₓ emissions from this type of stove were only dependent on the fuel-nitrogen content and not on the moisture content

Mapping the recovery of the burnt vegetation by classifying pre- and post-fire spectral indices

[EN] This study analyzed the state of recovery of the burnt vegetation in the National Park of Torres del Paine between December, 2011 and March, 2012. The calculation and comparison of the NVDI (normalized difference vegetation index) of the burnt area throughout a time series of 24 Landsat images acquired before, during and after the fire (2009- 2015), showed the temporal variation in the biomass levels of the burnt vegetation. The subsequent classification and comparison of the spectral indices: NDVI, NBR (normalized burnt ratio) and NDWI (normalized difference water index) on a full-data available and phenologically matched pre- and post-fire image pair (acquired in October 2009 and 2014), enabled to analyze and mapping the state of recovery of the burnt vegetation. The results show that the area of the lowest classes of all the spectral indices of the pre-fire date became the most dominant on the post-fire date. The pre- and post- fire NDVI class crossing by a confusion matrix showed that the highest and most prevailing pre-fire NDVI classes, mostly corresponding to hydromorphic forests and Andean scrubs, turned into the lowest class in 2014. The remaining area, comprising Patagonian steppe, reestablished its biomass levels in 2014, mostly exhibiting the same pre-fire NDVI classes. These results may provide guidelines to monitor and manage the regeneration of the vegetation impacted by this fire.[ES] Este trabajo analizó el estado de recuperación de la vegetación del Parque Nacional Torres del Paine, incendiada entre Diciembre de 2011 y Marzo de 2012. El cálculo y comparación del NDVI (normalized difference vegetation index) del área afectada a lo largo de una serie temporal de 24 imágenes Landsat adquiridas antes, durante y después del incendio (2009-2015), permitió apreciar la variación temporal en los niveles de biomasa de la vegetación afectada. La posterior clasificación y comparación de los índices espectrales NDVI, NBR (normalized burnt ratio) y NDWI (normalized difference water index), en un par de imágenes pre- y post-incendio con disponibilidad de datos completos y fenológicamente compatibles (adquiridas en Octubre de 2009 y 2014), permitió analizar y mapear el estado de recuperación de la vegetación afectada. Los resultados muestran que el área de las dos clases inferiores de todos los índices espectrales de la fecha pre-incendio pasó a ser la más dominante en la fecha post-incendio. El cruce de clases de NDVI pre- y post-incendio mediante una matriz de error evidenció que la clase más alta y prevaleciente de NDVI pre-incendio, correspondiente en su mayor parte a bosque higromórfico y matorral preandino, se tornó la clase más baja en 2014. El resto del área de estudio, compuesta principalmente por estepa patagónica, restableció sus niveles de biomasa en 2014, exhibiendo en gran medida las mismas clases de NDVI pre-incendio. Estos resultados podrían proveer directrices para el monitoreo y manejo de la regeneración de la vegetación impactada por este incendio.Peña, MA.; Ulloa, J. (2017). Mapeo de la recuperación de la vegetación quemada mediante la clasificación de índices espectrales pre- y post-incendio. Revista de Teledetección. (50):37-48. doi:10.4995/raet.2017.7931SWORD374850Abdel Malak, D., & Pausas, J. G. (2006). Fire regime and post-fire Normalized Difference Vegetation Index changes in the eastern Iberian peninsula (Mediterranean basin). International Journal of Wildland Fire, 15(3), 407. doi:10.1071/wf05052Bastos, A., Gouveia, C. M., DaCamara, C. C., & Trigo, R. M. (2011). Modelling post-fire vegetation recovery in Portugal. Biogeosciences, 8(12), 3593-3607. doi:10.5194/bg-8-3593-2011CEQUA (Centro de Estudios del Cuaternario FuegoPatagonia y Antártica). 2014. Difusión cartográfica digital a escala local Parque Nacional Torres del Paine. Punta Arenas: CEQUA.Chen, X., Vogelmann, J. E., Rollins, M., Ohlen, D., Key, C. H., Yang, L., … Shi, H. (2011). Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest. International Journal of Remote Sensing, 32(23), 7905-7927. doi:10.1080/01431161.2010.524678De Santis, A., & Chuvieco, E. (2007). Burn severity estimation from remotely sensed data: Performance of simulation versus empirical models. Remote Sensing of Environment, 108(4), 422-435. doi:10.1016/j.rse.2006.11.022Díaz-Delgado, R., Lloret, F., & Pons, X. (2003). Influence of fire severity on plant regeneration by means of remote sensing imagery. International Journal of Remote Sensing, 24(8), 1751-1763. doi:10.1080/01431160210144732Díaz-Delgado, R., Salvador, R., Pons, X. 1998. Monitoring of plant community regeneration after fire by remote sensing. En: L. Traboud (Ed.), Fire management and landscape ecology (pp. 315–324). Fairfield, WA: International Association of Wildland Fire.Escuin, S., Navarro, R., & Fernández, P. (2007). Fire severity assessment by using NBR (Normalized Burn Ratio) and NDVI (Normalized Difference Vegetation Index) derived from LANDSAT TM/ETM images. International Journal of Remote Sensing, 29(4), 1053-1073. doi:10.1080/01431160701281072Garay, G, Guineo, O. 1995. Conociendo la flora y monta-a de "Torres del Paine". Punta Arenas: Impresiones Don Bosco.Gouveia, C., DaCamara, C. C., & Trigo, R. M. (2010). Post-fire vegetation recovery in Portugal based on spot/vegetation data. Natural Hazards and Earth System Science, 10(4), 673-684. doi:10.5194/nhess-10-673-2010Jones, H, Vaughan, R. 2010. Remote sensing of vegetation: Principles, techniques and applications. New York: Oxford University Press.Kushla, J. D., & Ripple, W. J. (1998). Assessing wildfire effects with Landsat thematic mapper data. International Journal of Remote Sensing, 19(13), 2493-2507. doi:10.1080/014311698214587Liang, S., Li, X., Wang, J. 2012. Advanced remote sensing. Terrestrial information extraction and applications. Oxford: Academic Press.Pe-a, M. 2008. Relationships between remotely sensed surface parameters associated with the urban heat sink formation in Santiago, Chile. International Journal of Remote Sensing, 29(5), 4385-4404.Villa-Martínez, R., & Moreno, P. I. (2007). Pollen evidence for variations in the southern margin of the westerly winds in SW patagonia over the last 12,600 years. Quaternary Research, 68(3), 400-409. doi:10.1016/j.yqres.2007.07.00

Fluoride and oral health

The discovery during the first half of the 20th century of the link between natural fluoride, adjusted fluoride levels in drinking water and reduced dental caries prevalence proved to be a stimulus for worldwide on-going research into the role of fluoride in improving oral health. Epidemiological studies of fluoridation programmes have confirmed their safety and their effectiveness in controlling dental caries. Major advances in our knowledge of how fluoride impacts the caries process have led to the development, assessment of effectiveness and promotion of other fluoride vehicles including salt, milk, tablets, toothpaste, gels and varnishes. In 1993, the World Health Organization convened an Expert Committee to provide authoritative information on the role of fluorides in the promotion of oral health throughout the world (WHO TRS 846, 1994). This present publication is a revision of the original 1994 document, again using the expertise of researchers from the extensive fields of knowledge required to successfully implement complex interventions such as the use of fluorides to improve dental and oral health. Financial support for research into the development of these new fluoride strategies has come from many sources including government health departments as well as international and national grant agencies. In addition, the unique role which industry has played in the development, formulation, assessment of effectiveness and promotion of the various fluoride vehicles and strategies is noteworthy. This updated version of ‘Fluoride and Oral Health’ has adopted an evidence-based approach to its commentary on the different fluoride vehicles and strategies and also to its recommendations. In this regard, full account is taken of the many recent systematic reviews published in peer reviewed literature

Examining the Relationships among the Coaching Climate, Life Skills Development and Well-Being in Sport

Using Benson and Saito's framework for positive youth development, we investigated the relationships between the coaching climate, young people's perceived life skills development within sport, and their psychological well-being. British youth sport participants (N=326, Mage=13.81, range=11–18 years) completed a survey assessing the coaching climate, participants' perceived life skills development (teamwork, goal setting, time management, emotional skills, interpersonal communication, social skills, leadership, and problem solving and decision making) and psychological well-being (self-esteem, positive affect, and satisfaction with life). In all analyses, the coaching climate was positively related to young peoples' perceived development of life skills within sport and their psychological well-being. Total life skills development (a summative score of all eight life skills scores) was positively related to all three psychological well-being indicators – providing support for the "pile-up" effect – and partially mediated the relationships between the coaching climate and participants' psychological well-being. Interpretation of the results indicated that coaches should foster the development of multiple life skills in youth sport participants, as they are associated with participants' psychological well-being. One way this can be achieved is through autonomy-supportive coaching behaviours

An evaluation of the anti-proliferative and pro-apoptotic properties of Nigella Sativa

Background: Nigella sativa is a traditional herb used since ancient Egyptian and Greek civilizations. It is also known as black seed, black cumin, and as the blessed seed, after its reported extraordinary curing ability. Nigella sativa has a broad range of therapeutic properties including anti-cancer, anti-oxidant, anti-inflammatory, anti-microbial, anti-helminthic, and anti-fungal activities. Objective: The aim of this study was to evaluate the anti-cancer properties of Nigella sativa oil on the Jurkat E6.1 cell line. Method: Investigation of the anti-cancer properties of Nigella sativa oil in the human T lymphoblastic Jurkat E6.1 cell line was undertaken evaluating 4 different concentrations (undiluted, diluted 1:10,1:50 and 1:100) at three time points (24, 48 and 72 hours). Cell viability was assessed using the vital dye, trypan blue. Apoptosis was detected using the Human Annexin V assay by flow cytometry. Wilcoxon Signed–Rank test was used for statistical analysis. A p-value ≼ 0.05 was considered statistically significant. Results: Cells treated with undiluted oil could not be assessed by trypan blue due to the hydrophobicity of oil and bubble formation when mixed with culture media. The 1:10 dilution had the highest percentage of non-viable cells with 92.78% followed by 90.53% and 67.62% for the 1:50 and 1:100 dilutions, respectively, after 72 hours. Cells treated with undiluted oil had 58.18% apoptotic cells followed by 44.3%, 33.89% and 26.81% for the 1:10, 1:50 and 1:100 dilutions respectively. Conclusion: Nigella sativa seed oil induced apoptosis and inhibited cell proliferation in the Jurkat E6.1 cell line in vitro in a time- and dosage-dependant manner. Further research is required to determine whether Nigella sativa demonstrates similar efficacy in other leukaemic cell lines, and other cancer types, and also to determine which bioactive constituent(s) present is(are) responsible

Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions