First trait-based characterization of Arctic ice meiofauna taxa

Trait-based approaches connect the traits of species to ecosystem functions to estimate the functional diversity of communities and how they may respond to environmental change. For the first time, we compiled a traits matrix across 11 traits for 28 species of Arctic ice meiofauna, including Copepoda (Subclass), Nematoda (Phylum), Acoela (Order), Rotifera (Phylum), and Cnidaria (Phylum). Over 50 years of pan-Arctic literature were manually reviewed, and trait categories were assigned to enable future trait–function connections within the threatened ice-associated ecosystem. Approximately two-thirds of the traits data were found at the genus or species level, ranging from 44% for Nematoda to 100% for Cnidaria. Ice meiofauna were shown to possess advantageous adaptations to the brine channel network within sea ice, including a majority with small body widths < 200 μm, high body flexibility, and high temperature and salinity tolerance. Diets were found to be diverse outside of the algal bloom season, with most organisms transitioning to ciliate-, omnivore-, or detritus-based diets. Eight species of the studied taxa have only been recorded within sea ice, while the rest are found in a mixture of sympagic–pelagic–benthic habitats. Twelve of the ice meiofauna species have been found with all life stages present in sea ice. Body width, temperature tolerance, and salinity tolerance were identified as traits with the largest research gaps and suffered from low-resolution taxonomic data. Overall, the compiled data show the degree to which ice meiofauna are adapted to spending all or portions of their lives within the ice

Seasonality of vertical flux and sinking particle characteristics in an ice-free high arctic fjord—Different from subarctic fjords?

Source: http://dx.doi.org/10.1016/j.jmarsys.2015.10.003 A manuscript version of this article is part of Ingrid Wiedmann's doctoral thesis, which is available in Munin at http://hdl.handle.net/10037/8293The arctic Adventfjorden (78°N, 15°E, Svalbard) used to be seasonally ice-covered but has mostly been ice-free since 2007. We used this ice-free arctic fjord as a model area to investigate (1) how the vertical fl ux of biomass (chlorophyll a and particulate organic carbon, POC) follows the seasonality of suspended material, (2) how sink- ing particle characteristics change seasonally and affect the vertical fl ux, and (3) if the vertical fl ux in the ice-free arctic fjord with glacial runoff resembles the fl ux in subarctic ice-free fjords. During seven fi eld investigations (December 2011 – September 2012), suspended biomass was determined (5, 15, 25, and 60 m), and short-term sediment traps were deployed (20, 30, 40, and 60 m), partly modi fi ed with gel- fi lled jars to study the size and frequency distribution of sinking particles. During winter, resuspension from the sea fl oor resulted in large, detrital sinking particles. Intense sedimentation of fresh biomass occurred during the spring bloom. The highest POC fl ux was found during autumn (770 – 1530 mg POC m − 2 d − 1 ), associated with sediment-loaded glacial runoff and high pteropod abundances. The vertical biomass fl ux in the ice-free arctic Adventfjorden thus resem- bled that in subarctic fjords during winter and spring, but a higher POC sedimentation was observed during autumn

The occurrence of Nematoda in coastal sea ice on Svalbard (European Arctic) determined with the 18S small subunit rRNA gene

Understanding the diversity and functioning of Arctic sea ice ecosystems is vital to evaluate and predict the impact of current and future climate change. In the microscopic communities inhabiting the brine channels inside sea ice, nematodes often dominate numerically and act as bacterivores and herbivores. Despite nematodes great abundances and known ecological roles, molecular tools have not been applied to investigate their species diversity in sea ice. In an attempt to begin establishing a molecular baseline for species diversity of sea ice nematodes, we Sanger sequenced 74 specimens from four locations around Svalbard (European Arctic), using the 18S rRNA barcode. Currently available nucleotide reference databases are both underpopulated with representative marine nematode taxa and contain a substantial number of misidentified organisms. Together, these limitations inhibited the ability to identify marine specimens collected in this study with certainty. Nevertheless, our molecular data indicate the presence of two genera in sea ice on Svalbard—Theristus and Halomonhystera. While it is possible that the latter represents a novel ice nematode species, future studies, including morphometric analysis, are needed to verify our molecular findings. We leverage the assignment of molecular information to robustly identify nematodes and provide the first insight into the diversity of sea ice nematodes in the European Arctic. We advocate for an intensified cooperation between molecular and morphological taxonomists to expedite the establishment of baseline surveys that are required to predict biological consequences of the diminishing sea ice habitat in the future

Applied sketching in HCI:Hands-on course of sketching techniques

Hand-drawn sketches are an easy way for researchers to communicate and express ideas, as well as document, explore and describe concepts between researcher, user, or client. Sketches are fast, easy to create, and – by varying their fidelity – they can be used in all areas of HCI. The Applied Sketching in HCI course will explore and demonstrate themes around sketching in HCI with the aim of producing tangible outputs. Those attending will leave the course with the confidence to engage actively with sketching on a day-to-day basis. Participants will be encouraged to apply what they have learnt to their own research

Sketching in HCI:Hands-on course of sketching techniques

Freehand sketching is a valuable process, input, output, and tool, often used by people to communicate and express ideas, as well as document, explore and describe concepts between researcher, user, or client. Sketches are fast, easy to create, and - by varying their fidelity - can be used in all areas of HCI. Sketching in HCI will explore and demonstrate themes around sketching in HCI with the aim of producing tangible outputs. Attendees will leave the course with the confidence to engage actively with sketching on an everyday basis in their research practice

SketchBlog #1:the rise and rise of the sketchnote

The Interactions website (interactions.acm.org) hosts a stable of bloggers who share insights and observations on HCI, often challenging current practices. Each issue we'll publish selected posts from some of the leading and emerging voices in the field

Sketchi:Hands-on special interest group on sketching in HCI

Sketching is of great value as a process, input, output and tool in HCI, but can be confined to individual ideation or note-taking, as few researchers have the confidence to document events, studies and workshops under the public gaze. The recent surge in interest in this sometimes-overlooked skill has manifested itself in courses, workshops and live-scribing of high-profile events – and a renewed enthusiasm for freehand sketching as a formal part of the research process at all levels. SketCHI aims to address both research interests and sketching practice in a combined approach to define, discuss and deliver theory and methods to a broad audience. As well as structuring high level discussions and collating information and resources, this SIG will allow attendees to practice and explore observational sketching on location around the conference, with feedback and encouragement from industry professionals. Finally, attendees will be encouraged to collaborate and form a research community around sketching in HCI

Carrier Recombination in Highly Uniform and Phase-Pure GaAs/(Al,Ga)As Core/Shell Nanowire Arrays on Si(111): Mott Transition and Internal Quantum Efficiency

GaAs-based nanowires are among the most promising candidates for realizing a monolithical integration of III-V optoelectronics on the Si platform. To realize their full potential for applications as light absorbers and emitters, it is crucial to understand their interaction with light governing the absorption and extraction efficiency, as well as the carrier recombination dynamics determining the radiative efficiency. Here, we study the spontaneous emission of zincblende GaAs/(Al,Ga)As core/shell nanowire arrays by $\mu$-photoluminescence spectroscopy. These ordered arrays are synthesized on patterned Si(111) substrates using molecular beam epitaxy, and exhibit an exceptionally low degree of polytypism for interwire separations exceeding a critical value. We record emission spectra over more than five orders of excitation density for both steady-state and pulsed excitation to identify the nature of the recombination channels. An abrupt Mott transition from excitonic to electron-hole-plasma recombination is observed, and the corresponding Mott density is derived. Combining these experiments with simulations and additional direct measurements of the external quantum efficiency using a perfect diffuse reflector as reference, we are able to extract the internal quantum efficiency as a function of carrier density and temperature as well as the extraction efficiency of the nanowire array. The results vividly document the high potential of GaAs/(Al,Ga)As core/shell nanowires for efficient light emitters integrated on the Si platform. Furthermore, the methodology established in this work can be applied to nanowires of any other materials system of interest for optoelectronic applications

SketCHI 2.0: Hands-On Special Interest Group on Sketching in HCI

Sketching is universal. It enables us to work through problems, communicate complexity, work with people who have diverse needs, and document work processes we employ within Human-Computer Interaction. Increased interest in sketching as a methodology within HCI has led to increased attendance of interactive courses, meet-ups, and discussion groups, from those who are complete beginners, to seasoned researchers with the skills and knowledge to support others. By bringing together these individuals, we are able to advance the understanding of how sketching underpins research, and how we might work with sketching as technology advances. SketCHI 2.0 aims to support ongoing discussions and collaborations around sketching in HCI, and further build the Sketching HCI community. As well as drawing on location, feedback, and discussion, we will form collaborative working groups to further our collective interest in this area and conduct high-level discussions about the practical applications and outputs of sketching in HCI

Sketching & drawing as future inquiry in HCI

Creating visual imagery helps us to situate ourselves within unknown worlds, processes, make connections, and find solutions. By exploring drawn ideas for novel technologies, we can examine the implications of their place in the world. Drawing, or sketching, for future inquiry in Human Computer Interaction (HCI) can be a stand-alone investigative approach, part of a wider ‘world-building’ in design fiction, or simply ideation around a concept. By examining instances of existing practice in HCI, in this paper we establish recommendations and rationales for those wishing to utilise sketching and drawing within their research. We examine approaches ranging from ideation, diagramming, scenario building, comics creation and artistic representation to create a model for sketching and drawing as future inquiry for HCI. This work also reflects on the ways in which these arts can inform and elucidate research and practice in HCI, and makes recommendations for the field, within its teaching, processes and outcomes