Objects, subjects, bits and bytes: learning from the digital collections of the National Museums

This paper is concerned with online museum education, exploring the themes of user-centredness, digitization, authority and control. Taking as its starting point the shift of focus in museum policy from the collection to the user-learner, it suggests that this movement from object to subject – this ‘de-centring’ of the cultural institution – is further complicated by a fundamental change in the nature of the object, as a result of digitization programmes which transform material, ‘possessible’ artefacts into volatile amalgams of bits and bytes. The ability of users to take, manipulate, re-distribute and re-describe digital objects is, we suggest, a primary source of their educational value. It is also, however, a source of difficulty for institutions as they come to terms with the changing patterns of ownership, participation and knowledge production we are experiencing as we move further into the digital age

The equivalence of information-theoretic and likelihood-based methods for neural dimensionality reduction

Stimulus dimensionality-reduction methods in neuroscience seek to identify a low-dimensional space of stimulus features that affect a neuron's probability of spiking. One popular method, known as maximally informative dimensions (MID), uses an information-theoretic quantity known as "single-spike information" to identify this space. Here we examine MID from a model-based perspective. We show that MID is a maximum-likelihood estimator for the parameters of a linear-nonlinear-Poisson (LNP) model, and that the empirical single-spike information corresponds to the normalized log-likelihood under a Poisson model. This equivalence implies that MID does not necessarily find maximally informative stimulus dimensions when spiking is not well described as Poisson. We provide several examples to illustrate this shortcoming, and derive a lower bound on the information lost when spiking is Bernoulli in discrete time bins. To overcome this limitation, we introduce model-based dimensionality reduction methods for neurons with non-Poisson firing statistics, and show that they can be framed equivalently in likelihood-based or information-theoretic terms. Finally, we show how to overcome practical limitations on the number of stimulus dimensions that MID can estimate by constraining the form of the non-parametric nonlinearity in an LNP model. We illustrate these methods with simulations and data from primate visual cortex

Floating Widgets: Interaction with Acoustically-Levitated Widgets

Acoustic levitation enables new types of human-computer interface, where the content that users interact with is made up from small objects held in mid-air. We show that acoustically-levitated objects can form mid-air widgets that respond to interaction. Users can interact with them using in-air hand gestures. Sound and widget movement are used as feedback about the interaction

Textured Surfaces for Ultrasound Haptic Displays

We demonstrate a technique for rendering textured haptic surfaces in mid-air, using an ultrasound haptic display. Our technique renders tessellated 3D `haptic' shapes with different waveform properties, creating surfaces with distinct perceptions

The Gore Iliac Branch Endoprosthesis as an alternate aortic main body: Promising results in select patients

No abstrac

Objects, subjects, bits and bytes: learning from the digital collections of the National Museums

This paper is concerned with online museum education, exploring the themes of user-centredness, digitization, authority and control. Taking as its starting point the shift of focus in museum policy from the collection to the user-learner, it suggests that this movement from object to subject – this ‘de-centring’ of the cultural institution – is further complicated by a fundamental change in the nature of the object, as a result of digitization programmes which transform material, ‘possessible’ artefacts into volatile amalgams of bits and bytes. The ability of users to take, manipulate, re-distribute and re-describe digital objects is, we suggest, a primary source of their educational value. It is also, however, a source of difficulty for institutions as they come to terms with the changing patterns of ownership, participation and knowledge production we are experiencing as we move further into the digital age

Survival of patients undergoing surgery for metastatic spinal tumours and the impact of surgical site infection

Background Patients with metastatic spinal tumours have a limited prognosis. Surgical complications which may result in prolonged hospitalisation or readmission are highly undesirable. Surgical site infection (SSI) is one such complication which can, in extreme cases, lead to death. Aim To assess the impact of SSI on patient survival after surgery for spinal metastases. Methods Demographic, operative and survival data were collected on 152 patients undergoing surgery for spinal metastases at Salford Royal NHS Foundation Trust. American Society of Anesthesiologists (ASA) grade and the Revised To kuhashi Score (RTS) were obtained as measures of health status at baseline. A semi-parametric Cox proportional hazards survival analysis was used to assess the relationships between covariates and survival. Results Mean age at operation was 60.5 years (standard deviation 12.9 years). Seventeen patients (11.2%) experienced SSI. At the time of last follow up, 117 patients had died. RTS score (p<0.001; hazard ratio 0.82; 95% confidence interval: 0.76-0.87) and ASA grade (p=0.022; hazard ratio 1.40; 95% confidence interval: 1.05-1.87) were significantly associated with survival, with better survival found in patients with higher RTS and lower ASA scores. Infection status was of substantive importance, with better survival in those without SSI (p=0.075). Age was not substantively related to survival (p=0.299). Overall, median survival time from operation was 262 days (95% confidence interval: 190-334 days). Conclusions Five-year survival in patients undergoing surgery for spinal metastases is approximately 23%. Either or both of RTS or ASA scores can be used as indicators of patient survival. There is insufficient evidence to conclude that the presence of SSI retards survival

MS

thesisThe Green River Formation (Eocene) shows a diversity of lacus­trine carbonate lithologies comparable to carbonate formations of marine origin. Petrographic analyses of nearly 100 thin sections show that fossils (calcareous algae, ostracodes, gastropods, pelecypods), coated grains, microcrystalline carbonate aggregates, sparry carbonate, microcrystalline carbonate and terrigenous grains are the main rock-forming components of the lacustrine carbonate rocks. The most abundant allochemical constituents are polygenetic microcrys­ talline carbonate aggregates (intraclasts, pellets) and fragmental algal "plates." Coated grains (ooliths, pisoliths, circumcrusts) are also common and probably are biochemical (algal ?) precipitates. Pore-filling sparry calcite and neomorphic sparry calcite are the dominant orthochemical constituents in some rocks, however microcrystalline carbonate clearly is the most abundant orthochemical constituent in the formation. Terrigenous constituents are present in nearly all carbonate rocks; they compose up to 50 percent of some carbonate rocks. Micrite and sandy and silty carbonate rocks are the most, abundant carbonate lithologies in the Green River Formation. Sparites and low- terrigenous carbonate rocks are less common. The similarity of lacustrine carbonate rock components and lithologies with marine carbonate components and lithologies leads to the conclusion that lacustrine carbonate rocks can not be differentiated from marine carbonate rocks solely on the basis of petrographic relationships. Subenvironments of deposition are recognized on the basis of lithologic variations, sedimentary structures, stratification, color and lithologic associations within the formation. Nearshore and shore­ line environments are represented by cleanly washed allochem-sparite, sandy and silty sparite, and biohermal and biostromal algal biolithite whereas lagoonal, mudflat and offshore deeper water deposition is char­ acterized by micrite, allochem-micrite and sandy, silty and clayey micrite. Diagenesis has caused substantial changes in the carbonate rocks, including neomorphism of microcyrstalline carbonate mud to coarser microcrystalline calcite and sparry calcite. Dolomicrite is ubiquitous in the formation and probably formed during early diagenesis prior to lithification as a replacement product of calcium carbonate micrite. Stable carbon and oxygen isotopes were analyzed in an effort to evaluate the effects of biological precipitation of calcium carbonate and to determine whether dolomicrite formed as a primary precipitate or by replacement of calcium carbonate. Preliminary results suggest a biogenic fractionation for the microcrystalline carbonate of ooliths, pisoliths and certain microcrystalline carbonate aggregates; an inorganic origin for most micrite not incorporated in allochems; and an early diagenetic replacement origin for dolomicrite

A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, New Mexico, and a revision of taeniolabidoid systematics and phylogeny

Multituberculates were amongst the most abundant and taxonomically diverse mammals of the late Mesozoic and the Paleocene, reaching their zenith in diversity and body size in the Paleocene. Taeniolabidoidea, the topic of this paper, includes the largest known multituberculates, which possess highly complex cheek teeth adapted for herbivory. A new specimen from the early Paleocene (middle Puercan; biochron Pu2) of the Nacimiento Formation, New Mexico represents a new large-bodied taeniolabidoid genus and species, Kimbetopsalis simmonsae. A phylogenetic analysis to examine the relationships within Taeniolabidoidea that includes new information from Kimbetopsalis gen. et sp. nov. and gen. nov. and from new specimens of Catopsalis fissidens, first described here, and data from all other described North American and Asian taeniolabidoids. This analysis indicates that Catopsalis is nonmonophyletic and justifies our transfer of the basal-most taeniolabidoid ‘Catopsalis’ joyneri to a new genus, Valenopsalis. Kimbetopsalis and Taeniolabis form a clade (Taeniolabididae), as do the Asian Lambdopsalis, Sphenopsalis, and possibly also Prionessus (Lambdopsalidae). Taeniolabidoids underwent a modest taxonomic radiation during the early Paleocene of North America and underwent a dramatic increase in body size, with Taeniolabis taoensis possibly exceeding 100 kg. Taeniolabidoids appear to have gone extinct in North America by the late Paleocene but the appearance of lambdopsalids in the late Paleocene of Asia suggests that they dispersed from North America in the early to middle Paleocene