The Shelter Characteristics of Traditional-styled Inuit Snow Houses

The shelter value of snow iglus at Resolute (74 41 N, 94 54 W) in the Canadian High Arctic was assessed. After a survey of snow conditions, construction sites were chosen and two iglus were built and furnished in a traditional way. A large iglu (4.1 m diameter) contained 72 blocks averaging 23.6 kg and had a surface area-to-volume ratio of 2.21:1. A smaller iglu (3.05 m in diameter) contained 46 blocks averaging 28.2 kg and had a surface area-to-volume ratio of 1.73:1. The smaller iglu provided 75% of the large iglu's space for 76.5% of its mass. Snow hardness averaged 12000 g/sq. cm, and the mean density of the snow was 397 kg per cu m. The energy required to build and heat each iglu was calculated from the snow characteristics, construction activities and microclimate parameters measured during occupancy. Heat flux was calculated for human bodies, kudliks (seal oil lamps), and geothermal sources at temperature differentials as high as 45 C from ambient, for both the unlined large iglu and the small iglu, which was lined with caribou skins on the inside. The smaller iglu was more efficient, requiring the fat of one seal every 6.3 days for heating, while the large iglu required the fat of one seal every 3.7 days. The meat content of each seal would have sustained a family of four for the same time interval, and the resultant body heat would have provided 8% to 14% of the total energy necessary to maintain comfortable temperatures within the iglu.On a évalué la valeur de la protection offerte par les igloos de neige à Resolute (74° 40' de latit. N.) dans l'Extrême-Arctique canadien. On a d'abord procédé à un relevé de l'état de la neige, puis choisi les sites et construit et équipé deux igloos de façon traditionnelle. Soixante-douze blocs de neige pesant en moyenne 23,6 kg ont servi à construire le grand igloo (4,1 m de diamètre) dont le rapport surface:volume était égal à 2,21. Quarante-six blocs pesant en moyenne 28,2 kg ont servi à la construction du petit igloo dont le rapport surface:volume était égal à 1,73. Ce petit igloo représentait 75 p. cent de l'espace du grand igloo pour 76,5 p. cent de sa masse. La dureté de la neige était en moyenne de 12 000 g/cm² et sa densité moyenne de 397 kg/m³. On a calculé l'énergie nécessaire pour construire et chauffer chaque igloo à partir des caractéristiques de la neige, des activités relatives à la construction et des paramètres du microclimat mesurés au cours de l'occupation. On a calculé le flux thermique pour les corps, les kudliks (lampes à l'huile de phoque) et les sources géothermiques à des différences de température allant jusqu'à 45 °C au-dessus de la température ambiante, et ce, pour le grand igloo nu et pour le petit qui, lui, était tapissé de peaux de caribou sur les parois internes. Le petit igloo était le plus éconergétique, ne consommant pour le chauffage que la graisse d'un phoque tous les 6,3 jours alors que le grand igloo en consommait autant tous les 3,7 jours. La viande de chaque phoque aurait assuré la subsistance d'une famille de quatre personnes au cours des mêmes périodes, et la chaleur animale qui en aurait résulté aurait fourni de 8 à 14 p. cent de l'énergie totale nécessaire pour maintenir une température confortable dans l'igloo

Prevalence of and Barriers to Dual-Contraceptive Methods Use among Married Men and Women Living with HIV in India

Objective. To describe the prevalence and correlates of dual-contraceptive methods use (condoms and an effective pregnancy prevention method) and barriers to their use among married persons living with HIV (PLHIV) in India. Methods. We conducted a quantitative survey (93 men, 97 women), 25 in-depth interviews, seven focus groups, and five key informant interviews. Results. Prevalence of dual- contraceptive method use increased from 5% before HIV diagnosis to 23% after diagnosis (P < 0.001). Condoms were the most common contraceptive method, with prevalence increasing from 13% before diagnosis to 92% after diagnosis (P < 0.001). Barriers to using noncondom contraceptives were lack of discussion about noncondom contraceptives by health care providers, lack of acceptability of noncondom contraceptives among PLHIV, and lack of involvement of husbands in family planning counseling. Conclusion. There is a need for interventions, including training of health care providers, to increase dual-contraceptive methods use among married PLHIV

"Clicking" trimeric peptides onto hybrid T8POSS nanocages and identifying synthesis limitations

Macromolecule branching upon polyhedral oligomeric silsesquioxanes (POSS) via "click" chemistry has previously been reported for promoting natural biological responses in vitro, particularly when regarding their demonstrated biocompatibility and structural robustness as potential macromolecule anchoring points. However, "clicking" of large molecules around POSS structures uncovers two main challenges: (1) a synthetic challenge encompassing multi-covalent attachment of macromolecules to a single nanoscale-central position, and (2) purification and separation of fully adorned nanocages from those that are incomplete due to their similar physical characteristics. Here we present peptide decoration to a T8POSS nanocage through the attachment of azido-modified trimers. Triglycine- and trialanine-methyl esters "clicked" to 97% and 92% completion, respectively, resulting in 84% and 68% yields of the fully-adorned octamers. The "clicks" halt within 27-h of the reaction time, and efforts to further increase the octamer yield were of negligible benefit. Exploration of reaction conditions reveals multiple factors preventing full octa-arm modification to all available POSS nanocages, and offers insights into macromolecule attachment between both peptides and small inorganic-organic structures, all of which require consideration for future work of this nature

A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells

Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many years because of their potential for large-scale manufacturing using roll-to-roll processing allied to their use of earth abundant raw materials. Two main challenges exist for DSC devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid electrolytes which can limit device lifetimes. To increase device efficiency requires optimized dye injection and regeneration, most likely from multiple dyes while replacement of liquid electrolytes requires solid charge transporters (most likely hole transport materials – HTMs). While theoretical and experimental work have both been widely applied to different aspects of DSC research, these approaches are most effective when working in tandem. In this context, this perspective paper considers the key parameters which influence electron transfer processes in DSC devices using one or more dye molecules and how modelling and experimental approaches can work together to optimize electron injection and dye regeneration. This paper provides a perspective that theory and experiment are best used in tandem to study DSC device

Randomized clinical trial of a brief and extensive dyadic intervention for advanced cancer patients and their family caregivers

Background Few intervention programs assist patients and their family caregivers to manage advanced cancer and maintain their quality of life (QOL). This study examined (i) whether patient–caregiver dyads (i.e., pairs) randomly assigned to a brief or extensive dyadic intervention (the FOCUS Program) had better outcomes than dyads randomly assigned to usual care and (ii) whether patients' risk for distress and other factors moderated the effect of the brief or extensive program on outcomes. Methods Advanced cancer patients and their caregivers ( N  = 484 dyads) were stratified by patients' baseline risk for distress (high versus low), cancer type (lung, colorectal, breast, or prostate), and research site and then randomly assigned to a brief (three‐session) or extensive (six‐session) intervention or control. The interventions offered dyads information and support. Intermediary outcomes were appraisals (i.e., appraisal of illness/caregiving, uncertainty, and hopelessness) and resources (i.e., coping, interpersonal relationships, and self‐efficacy). The primary outcome was QOL. Data were collected prior to intervention and post‐intervention (3 and 6 months from baseline). The final sample was 302 dyads. Repeated measures MANCOVA was used to evaluate outcomes. Results Significant group by time interactions showed that there was an improvement in dyads' coping ( p  < 0.05), self‐efficacy ( p  < 0.05), and social QOL ( p  < 0.01) and in caregivers' emotional QOL ( p  < 0.05). Effects varied by intervention dose. Most effects were found at 3 months only. Risk for distress accounted for very few moderation effects. Conclusions Both brief and extensive programs had positive outcomes for patient–caregiver dyads, but few sustained effects. Patient–caregiver dyads benefit when viewed as the ‘unit of care’. Copyright © 2012 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96760/1/pon3036.pd

"Clicking” trimeric peptides onto hybrid T₈POSS nanocages and identifying synthesis limitations

Macromolecule branching upon polyhedral oligomeric silsesquioxanes (POSS) via “click” chemistry has previously been reported for promoting natural biological responses in vitro, particularly when regarding their demonstrated biocompatibility and structural robustness as potential macromolecule anchoring points. However, “clicking” of large molecules around POSS structures uncovers two main challenges: (1) a synthetic challenge encompassing multi-covalent attachment of macromolecules to a single nano scale-central position, and (2) purification and separation of fully adorned nanocages from those that are incomplete due to their similar physical characteristics. Here we present peptide decoration to a T8POSS nanocage through the attachment of azido-modified trimers. Triglycine- and trialanine-methyl esters “clicked” to 97% and 92% completion, respectively, resulting in 84% and 68% yields of the fully-adorned octamers. The “clicks” halt within 27-h of the reaction time, and efforts to further increase the octamer yield were of negligible benefit. Exploration of reaction conditions reveals multiple factors preventing full octa-arm modification to all available POSS nanocages, and offers insights into macromolecule attachment between both peptides and small inorganic-organic structures, all of which require consideration for future work of this nature

Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial

This is the final version of the article. Available from Springer Nature via the DOI in this record.Contrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'). Here we exploit a bidecadally resolved (14)C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago). We observe no divergence between the kauri and Atlantic marine sediment (14)C data sets, implying limited changes in deep water formation. However, a Southern Ocean (Atlantic-sector) iceberg rafted debris event appears to have occurred synchronously with GI-5.1 warming and decreased precipitation over the western equatorial Pacific and Atlantic. An ensemble of transient meltwater simulations shows that Antarctic-sourced salinity anomalies can generate climate changes that are propagated globally via an atmospheric Rossby wave train.A challenge for testing mechanisms of past climate change is the precise correlation of palaeoclimate records. Here, through climate modelling and the alignment of terrestrial, ice and marine (14)C and (10)Be records, the authors show that Southern Ocean freshwater hosing can trigger global change.This work was funded by the Australian Research Council (FL100100195, DP170104665 and SR140300001) and the Natural Environment Research Council (NE/H009922/1 and NE/H007865/1)

Microplastics and nanoplastics in the marine-atmosphere environment

The discovery of atmospheric micro(nano)plastic transport and ocean-atmosphere exchange points to a highly complex marine plastic cycle, with negative implications for human and ecosystem health. Yet, observations are currently limited. In this Perspective, we quantify the processes and fluxes of the marine-atmospheric micro(nano)plastic cycle, with the aim of highlighting the remaining unknowns in atmospheric micro(nano)plastic transport. Between 0.013 and 25 million metric tons per year of micro(nano)plastics are potentially being transported within the marine atmosphere and deposited in the oceans. However, the high uncertainty in these marine-atmospheric fluxes is related to data limitations and a lack of study intercomparability. To address the uncertainties and remaining knowledge gaps in the marine-atmospheric micro(nano)plastic cycle, we propose a future global marine-atmospheric micro(nano)plastic observation strategy, incorporating novel sampling methods and the creation of a comparable, harmonized and global data set. Together with long-term observations and intensive investigations, this strategy will help to define the trends in marine-atmospheric pollution and any responses to future policy and management actions. Atmospheric transport of microplastics could be a major source of plastic pollution to the ocean, yet observations currently remain limited. This Perspective quantifies the known budgets of the marine-atmospheric micro(nano)plastic cycle and proposes a future global observation strategy.Peer reviewe