Electronic properties and phase transitions in low-dimensional semiconductors

We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X = Se, S, Te) compounds. These chalcogenides belong to a family of the low-dimensional semiconductors possessing chain or layered structure. They are of significant interest because of their highly anisotropic properties, semi- and photoconductivity, non-linear effects in their I-V characteristics (including a region of negative differential resistance), switching and memory effects, second harmonic optical generation, relaxor behavior and potential applications for optoelectronic devices. We review the crystal structure of TlX and TlMX2 compounds, their transport properties under ambient conditions, experimental and theoretical studies of the electronic structure, transport properties and semiconductor-metal phase transitions under high pressure, and sequences of temperature-induced structural phase transitions with intermediate incommensurate states. Electronic nature of the ferroelectric phase transitions in the above-mentioned compounds, as well as relaxor behavior, nanodomains and possible occurrence of quantum dots in doped and irradiated crystals is discussed.Comment: 70 pages, 38 figure

Low Levels of Human HIP14 Are Sufficient to Rescue Neuropathological, Behavioural, and Enzymatic Defects Due to Loss of Murine HIP14 in Hip14−/− Mice

Huntingtin Interacting Protein 14 (HIP14) is a palmitoyl acyl transferase (PAT) that was first identified due to altered interaction with mutant huntingtin, the protein responsible for Huntington Disease (HD). HIP14 palmitoylates a specific set of neuronal substrates critical at the synapse, and downregulation of HIP14 by siRNA in vitro results in increased cell death in neurons. We previously reported that mice lacking murine Hip14 (Hip14−/−) share features of HD. In the current study, we have generated human HIP14 BAC transgenic mice and crossed them to the Hip14−/− model in order to confirm that the defects seen in Hip14−/− mice are in fact due to loss of Hip14. In addition, we sought to determine whether human HIP14 can provide functional compensation for loss of murine Hip14. We demonstrate that despite a relative low level of expression, as assessed via Western blot, BAC-derived human HIP14 compensates for deficits in neuropathology, behavior, and PAT enzyme function seen in the Hip14−/− model. Our findings yield important insights into HIP14 function in vivo

Light-Induced Stomatal Opening Is Affected by the Guard Cell Protein Kinase APK1b.

Guard cells allow land plants to survive under restricted or fluctuating water availability. They control the exchange of gases between the external environment and the interior of the plant by regulating the aperture of stomatal pores in response to environmental stimuli such as light intensity, and are important regulators of plant productivity. Their turgor driven movements are under the control of a signalling network that is not yet fully characterised. A reporter gene fusion confirmed that the Arabidopsis APK1b protein kinase gene is predominantly expressed in guard cells. Infrared gas analysis and stomatal aperture measurements indicated that plants lacking APK1b are impaired in their ability to open their stomata on exposure to light, but retain the ability to adjust their stomatal apertures in response to darkness, abscisic acid or lack of carbon dioxide. Stomatal opening was not specifically impaired in response to either red or blue light as both of these stimuli caused some increase in stomatal conductance. Consistent with the reduction in maximum stomatal conductance, the relative water content of plants lacking APK1b was significantly increased under both well-watered and drought conditions. We conclude that APK1b is required for full stomatal opening in the light but is not required for stomatal closure

Displaced Voices: A Journal of Archives, Migration and Cultural Heritage Volume 1, Issue 1 (Summer 2020)

Displaced Voices is a biannual digital magazine produced twice a year by the Living Refugee Archive team at the University of East London. Displaced Voices aims to provide a digital platform for activists, archivists, researchers, practitioners and academics to contribute to issues pertaining to refugee and migration history; refugee and migrant rights; social justice; cultural heritage and archives. We welcome a range of contributions to the magazine including articles of between 1000-2000 words; reports on fieldwork in archival collections; book recommendations and reviews; and more creative pieces including (but not limited too) cartoons; photography; and poetry. We would also welcome news on activities; publication of reports, projects; letters and news from your own networks. We welcome submissions from all writers whether you are a student, practitioner, activist or established academic. The Displaced Voices online magazine is born out of the collaborative and intersectional work that we have been undertaking through our work with the refugee and migration archives housed at the University of East London. Our work to date has explored the intersections of refugee and migration studies with narrative and life history research linked to oral history methods and archival approaches to the preservation, documentation and accessibility of archival resources recording the refugee experience. This magazine is a collaborative project between the Living Refugee Archive at the University of East London; the Oral History Society Migration Special Interest Group and the International Association for the Study of Forced Migration Working Group on the History of Forced Migration and Refugees. Thematically we are looking to engage with articles that explore the intersection of refugee and forced migration studies; history and cultural heritage studies; narrative research; oral history and archival science