Pro Pelle Cutem: Photographing Furs for the Hudson’s Bay Company’s 250th Anniversary Celebrations in Canada

In 1920, the Hudson’s Bay Company (HBC) celebrated its 250^th anniversary through national and international events, as well as honours and benefits for its employees. The year 1920 was an important moment for the HBC, as it underwent institutional change to support the expansion of its department store operations through public relations and advertising strategies. Central to these strategies was an emphasis on the HBC’s central role in Canadian nation formation, and in particular its fur trade history. This article discusses the use of photography in the HBC’s 250^th anniversary celebrations through an analysis of photographs of fur. I trace photographic representations of fur through three moments: in the process of extraction (as trapped animal or dead pelt); in the process of preparation (as Indigenous bush labour); and in the process of consumption (as fur goods in a department store window). While the fur trade was declining in significance at the time of the 250^th anniversary celebrations, its symbolic status was essential to the Company’s burgeoning retail operations. In this article, I argue that the photograph of fur replaced the fur pelt as the central trade item of the HBC, and, further, that photography fused together nationalist and capitalist expansion in Canada.     

Structural coherency of graphene on Ir(111)

Low-pressure chemical vapor deposition allows one to grow high structural quality monolayer graphene on Ir(111). Using scanning tunneling microscopy, we show that graphene prepared this way exhibits remarkably large-scale continuity of its carbon rows over terraces and step edges. The graphene layer contains only a very low density of defects. These are zero-dimensional defects, edge dislocation cores consisting of heptagon-pentagon pairs of carbon atom rings, which we relate to small-angle in-plane tilt boundaries in the graphene. We quantitatively examined the bending of graphene across Ir step edges. The corresponding radius of curvature compares to typical radii of thin single-wall carbon nanotubes.     

Strongly Correlated Aromatic Molecular Conductor

Strongly correlated electronic molecules open the way for strong coupling between charge, spin, and lattice degrees of freedom to enable interdisciplinary fields, such as molecular electronic switches and plasmonics, spintronics, information storage, and superconducting circuits. However, despite exciting computational predictions and promising advantages to prepare flexible geometries, the electron correlation effect in molecules has been elusive. Here, the electron correlation effects of molecular plasmonic films are reported to uncover their coupling of charge, spin, lattice, and orbital for the switchable metal‐to‐insulator transition under external stimuli, at which the simultaneous transition occurs from the paramagnetic, electrical, and thermal conducting state to the diamagnetic, electrical, and thermal insulating state. In addition, density functional theory calculation and spectroscopic studies are combined to provide the mechanistic understanding of electronic transitions and molecular plasmon resonance observed in molecular conducting films. The self‐assembled molecular correlated conductor paves the way for the next generation integrated micro/nanosystems.     

Materials Informatics Reveals Unexplored Structure Space in Cuprate Superconductors

High-temperature superconducting cuprates have the potential to be transformative in a wide range of energy applications. In this work, the corpus of historical data about cuprates is analyzed using materials informatics, re-examining how their structures are related to their critical temperatures (Tc). The available data is highly clustered and no single database contains all the features of interest to properly examine trends. To work around these issues a linear calibration approach that allows the utilization of multiple data sources is employed, combining fine resolution data for which the Tc is unknown with coarse resolution data where it is known. The hybrid data set constructed enables the exploration of the trends in Tc with the apical and in-plane copper–oxygen distances. It is shown that large regions of the materials space have yet to be explored. Novel experiments relying on the nano-engineering of the crystal structure may enable the exploration of such new regions. Based on the trends identified it is proposed that single layer Bi-based cuprates are good candidate systems for such experiments.     

Evidence of Spin Frustration in a Vanadium Diselenide Monolayer Magnet

Monolayer VSe₂, featuring both charge density wave and magnetism phenomena, represents a unique van der Waals magnet in the family of metallic 2D transition‐metal dichalcogenides (2D‐TMDs). Herein, by means of in situ microscopy and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X‐ray and angle‐resolved photoemission, and X‐ray absorption, direct spectroscopic signatures are established, that identify the metallic 1T‐phase and vanadium 3d¹ electronic configuration in monolayer VSe₂ grown on graphite by molecular‐beam epitaxy. Element‐specific X‐ray magnetic circular dichroism, complemented with magnetic susceptibility measurements, further reveals monolayer VSe₂ as a frustrated magnet, with its spins exhibiting subtle correlations, albeit in the absence of a long‐range magnetic order down to 2 K and up to a 7 T magnetic field. This observation is attributed to the relative stability of the ferromagnetic and antiferromagnetic ground states, arising from its atomic‐scale structural features, such as rotational disorders and edges. The results of this study extend the current understanding of metallic 2D‐TMDs in the search for exotic low‐dimensional quantum phenomena, and stimulate further theoretical and experimental studies on van der Waals monolayer magnets.     

Lorene Squire’s Psychical Landscapes of Colonial/Modern Gender in the Canadian North

From 1937 to 1939, Lorene Squire was commissioned by The Beaver (the company magazine of the Hudson’s Bay Company) and Canadian Airways to produce photographs of the Canadian North suitable for their publications, focused on her specialisation in wildfowl photography, as well as landscapes, planes, and people. This article focuses on her 1938 commissions, and in particular two photographs of Indigenous women and two self-portraits. When these photographs are considered alongside photographs of white settler women, her correspondence, and her book Wildfowling With A Camera (1938), I argue that they offer insights into gender as a colonial concept (what María Lugones calls the ‘colonial/modern gender system’). I contend that the setting of the ‘North’ as a psychical landscape makes Squire’s contestations possible. Squire’s photographs resist common ways of depicting white and Indigenous women in the 1930s, but they do so in a way that is paradoxical and leaves intact the colonial/modern gender system. In addition to providing biographical information about Squire, this article contributes to theoretical and historical scholarship on the meaning of photographs of Indigenous people in Canada for projects of nation-building and northern economic development, as well as on how the North functions as a reference point for Canadian identity.     

Persistence and prevalence of pathogenic and extended-spectrum beta-lactamase-producing Escherichia coli in municipal wastewater treatment plant receiving slaughterhouse wastewater

We compared the prevalence of pathogenic and extended-spectrum beta-lactamase (ESBL) – producing Escherichia coli in effluents of a municipal wastewater treatment plant (WWTP) receiving wastewater from a slaughterhouse. A total of 1248 isolates were screened for the presence of virulence genes associated with enterohemorrhagic E. coli (EHEC) (stx₁, stx₂, and eae) and extraintestinal pathogenic E. coli (ExPEC) (sfa/focDE, kpsMT K1, hlyA, papEF, afa/draBC, clbN, f17A and cnf). The prevalence of atypical enteropathogenic E. coli (EPEC) was 0.7%, 0.2% and 0.5% in city wastewater, slaughterhouse wastewater and in the treated effluent, respectively. One stx_1a and stx_2b-positive E. coli isolate was detected in city wastewater. The prevalence of ExPEC was significantly higher in city wastewater (8.4%), compared to slaughterhouse wastewater (1.2%). Treatment in the WWTP did not significantly impact the prevalence of ExPEC in the outlet effluent (5.0%) compared to city wastewater. Moreover, the most potentially pathogenic ExPEC were isolated from city wastewater and from the treated effluent. ESBL-producing E. coli was also mainly detected in city wastewater (1.7%), compared to slaughterhouse wastewater (0.2%), and treated effluent (0.2%). One ESBL-producing E. coli, isolated from city wastewater, was eae-β1 positive. These results showed that pathogenic and/or ESBL-producing E. coli were mainly detected in human wastewater, and at a lesser extend in animal wastewater. Treatment failed to eliminate these strains which were discharged into the river, and then these strains could be transmitted to animals and humans via the environment.     

教室灯具和黑板灯具的选择

通过对灯具样品及教室照明数据的采集和整理,分析了教室灯具配光与教室照明、黑板灯具配光与黑板照明之间的内在关系,提出了正确设计和选用灯具的方法。     

Adaptive clustering for time series: Application for identifying cell cycle expressed genes

The biological problem of identifying the active genes during the cell division process is addressed. The cell division ensures the proliferation of cells, which is drastically aberrant in cancer cells. The studied genes are described by their expression profiles during the cell division cycle. Commonly, the identification process is a supervised approach based on an a priori set of reference genes, assumed as well-characterizing the cell cycle phases. Each studied gene is then classified by its peak similarity to one pre-specified reference gene. This classical approach suffers from two limitations. On the one hand, there is no consensus between biologists about the set of reference genes to consider for the identification process. On the other hand, the proximity measures used for genes expression profiles are unjustified and mainly based on the expression values regardless of the genes expression behavior. To identify genes expression profiles, a new adaptive clustering approach is proposed which consists of two main points. First, it allows in an unsupervised way the selection of a well-justified set of reference genes, to be compared with the pre-specified ones. Secondly, it enables the users to learn the appropriate proximity measure to use for genes expression data, a measure which will cover both proximity on values and on behavior. The adaptive clustering method is compared to a correlation-based approach through public and simulated genes expression data.     

GO-modified flexible polymer nanocomposites fabricated via 3D stereolithography

Graphene oxide (GO) induced enhancement of elastomer properties showed a great deal of potential in recent years, but it is still limited by the barrier of the complicated synthesis processes. Stereolithography (SLA), used in fabrication of thermosets and very recently in “flexible” polymers with elastomeric properties, presents itself as simple and user-friendly method for integration of GO into elastomers. In this work, it was first time demonstrated that GO loadings can be incorporated into commercial flexible photopolymer resins to successfully fabricate GO/elastomer nanocomposites via readily accessible, consumer-oriented SLA printer. The material properties of the resulting polymer was characterized and tested. The mechanical strength, stiffness, and the elongation of the resulting polymer decreased with the addition of GO. The thermal properties were also adversely affected upon the increase in the GO content based on differential scanning calorimetry and thermogravimetric analysis results. It was proposed that the GO agglomerates within the 3D printed composites, can result in significant change in both mechanical and thermal properties of the resulting nanocomposites. This study demonstrated the possibility for the development of the GO/elastomer nanocomposites after the optimization of the GO/“flexible” photoreactive resin formulation for SLA with suitable annealing process of the composite in future.