Sato Grassmannians for generalized Tate spaces

We generalize the concept of Sato Grassmannians of locally linearly compact topological vector spaces (Tate spaces) to the category limA of the "locally compact objects" of an exact category A, and study some of their properties. This allows us to generalize the Kapranov dimensional torsor Dim(X) and determinantal gerbe Det(X) for the objects of limA and unify their treatment in the determinantal torsor D(X). We then introduce a class of exact categories, that we call partially abelian exact, and prove that if A is partially abelian exact, Dim(X) and Det(X) are multiplicative in admissible short exact sequences. When A is the category of finite dimensional vector spaces on a field k, we recover the case of the dimensional torsor and of the determinantal gerbe of a Tate space, as defined by Kapranov and reformulate its properties in terms of the Waldhausen space S(A) of the exact category A. The advantage of this approach is that it allows to define formally in the same way the Grassmannians of the iterated categories lim^nA. We then prove that the category of Tate spaces is partially abelian exact, which allows us to extend the results on Dim and Det already known for Tate spaces to 2-Tate spaces, such as the multiplicativity of Dim and Det for 2-Tate spaces, as considered by Arkhipov-Kremnizer and Frenkel-Zhu.Comment: Major changes: different ordering of the sections; introduction of symmetric determinantal theories vs determinantal theorie

Quotations of the Middle Ages in the music of the ‘Gothic’ movement. An analytical survey

Recoge los trabajos presentados en el II Congreso sobre arte, literatura y cultura gótica urbana, celebrado en mayo 2013 en la Universidad Autónoma de MadridThe article deals with bands making the “Ethereal” type of music and their use of quotations of the Middle Ages. The first example is the track Il bagatto (2000) by Ataraxia. The primary source for Ataraxia’s music is a French dance published in 1530 which, in turn, reveals harmonic connections with an Italian one published in 1578. The two ancient dances, French and Italian, seem to have been conceived as separate developments from a common archaic tune. The Italian one was used in the Seventies by Angelo Branduardi, who added a text taken from the famous fresco of Pinzolo portraying the “danse macabre” (1539). Considering that the lyrics of Ataraxia’s Il bagatto show strong connections with Branduardi’s ones, we could say that the general network of ancient-modern references reveals its intriguing circular shape. The second example is the Troubadour song Reis glorios (12th century), put into music by Ordo Equitum Solis (1992) and Estampie (2000). Ordo Equitum Solis’ version shows characteristics that are typical of the philological ensembles: among the others, the efforts to follow the inner rhythm of the words and the renounce to any chordal support. Estampie’s version, on the contrary, aims to change the ancient tune into a sort of “pop song”, in the attempt to trap the text into a constant rhythm and to put it into a precise harmonic structure. To end, the common background of these bands shows how this kind of quotations can be traced back to the period following the production of Dead Can Dance in the years 1987-1990

Data-driven control design for neuroprotheses: a virtual reference feedback tuning (VRFT) approach

This paper deals with design of feedback controllers for knee joint movement of paraplegics using functional electrical stimulation (FES) of the paralyzed quadriceps muscle group. The controller design approach, virtual reference feedback tuning (VRFT), is directly based on open loop measured data and fits the controller in such a way that the closed-loop meets a model reference objective. The use of this strategy, avoiding the modeling step, significantly reduces the time required for controller design and considerably simplifies the rehabilitation protocols. Linear and nonlinear controllers have been designed and experimentally tested, preliminarily on a healthy subject and finally on a paraplegic patient. Linear controller is effective when applied on small range of knee joint angle. The design of a nonlinear controller allows better performances. It is also shown that the control design is effective in tracking assigned knee angle trajectories and rejecting disturbances

Rapid Screening of Alicyclobacillus acidoterrestris Spoilage of Fruit Juices by Electronic Nose: A Confirmation Study

Early screening ofAlicyclobacillus spp.in fruit juices is a major applicative goal for the food industry, since juice contamination can lead to considerable loss of quality, and subsequently, to economic damages for juice producers. This paper presents an accurate study to assess and confirm the EOS507 electronic nose's (EN) ability of diagnosingAlicyclobacillus acidoterrestrisspoilage in artificially contaminated fruit juices. The authors experimental results have shown that the EOS507 can early identify, just after 24 hours from inoculation, contaminated orange and pear juices with an excellent classification rate close to 90% and with a detection threshold as low as 103 cfu/ml. In apple juice the detection threshold was about 105 cfu/ml, thus requiring longer incubation times (72 hours). PLS regression of EOS507 data can be also used to predict with fair accuracy the colony-forming units concentration of the bacteria. These results were supported by the GC/MS/MS measurements of specific chemical markers, such as guaiacol

Inter-model variability and biases of the global water cycle in CMIP3 coupled climate models

Observed changes such as increasing global temperatures and the intensification of the global water cycle in the 20th century are robust results of coupled general circulation models (CGCMs). In spite of these successes, model-to-model variability and biases that are small in first order climate responses, however, have considerable implications for climate predictability especially when multi-model means are used. We show that most climate simulations of the 20th and 21st century A2 scenario performed with CMIP3 (Coupled Model Inter-comparison Project Phase 3) models have deficiencies in simulating the global atmospheric moisture balance. Large biases of only a few models (some biases reach the simulated global precipitation changes in the 20th and 21st centuries) affect the multi-model mean global moisture budget. An imbalanced flux of -0.14 Sv exists while the multi-model median imbalance is only -0.02 Sv. Moreover, for most models the detected imbalance changes over time. As a consequence, in 13 of the 18 CMIP3 models examined, global annual mean precipitation exceeds global evaporation, indicating that there should be a 'leaking' of moisture from the atmosphere whereas for the remaining five models a 'flooding' is implied. Nonetheless, in all models, the actual atmospheric moisture content and its variability correctly increases during the course of the 20th and 21st centuries. These discrepancies therefore imply an unphysical and hence 'ghost' sink/source of atmospheric moisture in the models whose atmospheres flood/leak. The ghost source/sink of moisture can also be regarded as atmospheric latent heating/cooling and hence as positive/negative perturbation of the atmospheric energy budget or non-radiative forcing in the range of -1 to +6 W m^-2 (median +0.1 W m^-2). The inter-model variability of the global atmospheric moisture transport from oceans to land areas, which impacts the terrestrial water cycle, is also quite high and ranges from 0.26 to 1.78 Sv. In the 21st century this transport to land increases by about 5% per century with a model-to-model range from 1 to 13%. We suggest that this variability is weakly correlated to the land-sea contrast in air temperature change of these models. Spatially heterogeneous forcings such as aerosols contribute to the variability in moisture transport, at least in one model. The polewards shifts of dry zones in climate simulations of the 21st century are also assessed. It is shown that the multi-model means of the two subsets of models with negative and positive imbalances in the atmospheric moisture budget produce spatial variability in the dry zone positions similar in size to the spatial shifts expected from 21st century global warming. Thus, the selection of models also affects the multi-model mean dry zone extension. In general, we caution the use of multi-model means of E - P fields and suggest self-consistency tests for climate models

Anthropogenic impact on Antarctic surface mass balance, currently masked by natural variability, to emerge by mid-century

Global and regional climate models robustly simulate increases in Antarctic surface mass balance (SMB) during the twentieth and twenty-first centuries in response to anthropogenic global warming. Despite these robust model projections, however, observations indicate that there has been no significant change in Antarctic SMB in recent decades. We show that this apparent discrepancy between models and observations can be explained by the fact that the anthropogenic climate change signal during the second half of the twentieth century is small compared to the noise associated with natural climate variability. Using an ensemble of 35 global coupled climate models to separate signal and noise, we find that the forced SMB increase due to global warming in recent decades is unlikely to be detectable as a result of large natural SMB variability. However, our analysis reveals that the anthropogenic impact on Antarctic SMB is very likely to emerge from natural variability by the middle of the current century, thus mitigating future increases in global sea level