Preservació digital al núvol

Ara que ja ningú qüestiona les publicacions digitals, l'accés obert o els repositoris de tipus institucional o temàtic, cal co-mençar a treballar en els temes de preservació. Som responsables d'assegurar l'accés i l'ús futurs dels documents digitals, hagin nascut en format digital o siguin fruit dels projectes de digitalització. En aquest article es parla sobre la preservació digital i els tipus de continguts, així com els conceptes, tipologies, costos i usos de l'anomenat «núvol». També es mostra un exemple de núvol privat, la preservació de tesis doctorals del TDX i es comenta una experiència de núvol públic, el DuraCloud.

Conversando con Eduardo Sevilla Guzmán. De la Sociología Rural a la Agroecología: la revalorización del conocimiento local como constante

Eduardo Sevilla Guzmán il·lustra l'especificitat de vàries disciplines centrades en el medi rural a partir de la seva pròpia experiència. Tal i com explica en l'entrevista, la seva deriva cap a les Ciències Socials es degué a la necessitat de sostreure's al domini que els interessos de latifundistes i multinacionals exercien sobre la recerca en l'escola d'enginyers on treballava. Més endavant, la necessitat de cercar una alternativa al que es coneix com agricultura "convencional" el dugué a focalitzar la seva atenció en l'estudi d'altres formes històriques i contemporànies de manejar els recursos naturals, confluint ¿amb la incorporació dels sabers locals i científics en Ciències Naturals- en l'Agroecologia. En tot aquest camí ha seguit de prop i col·laborat amb el SOC (Sindicato de Obreros del Campo), històrica i combativa associació de jornalers andalusos, i establert una xarxa internacional d'aliances acadèmiques i activistes en el camp dels estudis i les lluites camperoles. La seva aposta ¿com veurem tot seguit- és a favor d'un tipus d'investigació militant i pluriepistemològica.

Els estudis bibliomètrics basats en l'anàlisi de citacions en àrees d'humanitats en el període 1959-2008

[eng] Objective: To analyse the scientific papers studying citations in the areas of humanities during the period 1959-2008 and to determine the aspects evaluated. The main bibliometric aspects measured were type of study, obsolescence, dispersion, language, theme, author impact and self-citations.Methodology: Broad revision of the international literature in the area of library and information science in the period studied, and detailed analysis of 119 bibliometric studies.Results: Most of the few studies of this area are based on ad-hoc citation compilations. There is a certain predominance of philology. Library quarterly is the journal that has published most papers of this kind. The conclusions of these studies can be as useful as those in the experimental sciences; it would be useful to increase their number.

Aproximació al moviment "open access"

[eng] The article describes the background and current state of the open access (OA) movement. Its objectives --with roots in scientists' traditional desire to disseminate their works, in librarians' concerns about the serials crisis, and in technological advances-- were formally articulated in the Budapest Open Access Initiative (BOAI) declaration of 2002. This statement established two strategies for providing access to scientific information without any economic, technical, or legal obstacles: 1) publication of articles in OA journals or 2) deposit by authors of their works in stable institutional or subject-based repositories. The article suggests that this second "route" appears to offer greater possibilities of attaining open access in the short term. However, there still is a lot of work to be done in disseminating the concepts of OA and in training authors regarding procedures for depositing their works: in other words what is needed is a series of promotional activities for overcoming one of today's greatest challenges: author inertia.

La propietat intel·lectual dels resultats de la recerca en l'àmbit universitari

S'hi analitza el procés de transmissió dels drets de propietat intel·lectual dels resultats de la recerca universitària. Habitualment les universitats renuncien als seus possibles drets en benefici dels autors que, sovint, quan publiquen un article en una publicació periòdica, assignen els drets a l'editor de la revista. Finalment, aquest ven el producte, en forma de subscripció a les seves publicacions, a les universitats, on s'havia originat el procés. La crisi motivada per l¿augment dels preus de subscripció a les publicacions periòdiques, unida a les limitacions que el procés de transmissió dels drets de propietat intel·lectual imposa en l¿accés a la informació científica, bàsicper als científics, ja que la difusió dels seus treballs és a la base de la seva promoció, són l¿origen del moviment de lliure accés (open access). Aquesta iniciativa intenta retornar al món acadèmic el control dels processos de comunicació i distribució de la informació científica. Finalment, el creixement de la informació electrònica disponible ha provocat que les biblioteques deixin d¿adquirir exemplars impresos de les publicacions per a disposar d¿accés remot als continguts d¿aquestes publicacions en format electrònic. Aquest canvi implica que les biblioteques han de fer front a una sèrie de qüestions de caràcter legal a l'hora d¿adquirir les llicència d¿ús d¿aquests recursosdigitals.

Presentació del dossier Jornades sobre Metodologia de Recerca

L'impuls de l'activitat investigadora caracteritza actualment la major part de les polítiques educatives, i és una realitat inquestionable que augmenta les exigències institucionals relatives a la producció científica en un panorama cada vegada més internacionalitzat. El saber es difon mitjançant circuits cada vegada més ramificats i fluids, alhora que s'accedeix a un volum creixent de producció científica amb una facilitat impensable fa una década, pero també és un fet que es posen més en evidéncia els desfasaments entre ambits científics, entre famílies d'una determinada comunitat científica, entre perspectives agresolades i novedoses del coneixement, entre cosmovisions localistes i d'ampli calat, entre tecnologies transferibles i reflexions epistemologiques ... i podríem seguir mencionant una Ilarga sé-rie de contradiccions que impregnen la nostra realitat diaria. En definitiva, si bé és cert que es tracta de popularitzar l'activitat investigadora, també ho és que es multipliquen determinades barreres que amb més o menys subtilesa s'han d'esquivar perqué la investigació i els seus resultats siguin una realitat tangible.

Oscillatory magnetic tweezers based on ferromagnetic beads and simple coaxial coils

We report the design and validation of simple magnetic tweezers for oscillating ferromagnetic beads in the piconewton and nanometer scales. The system is based on a single pair of coaxial coils operating in two sequential modes: permanent magnetization of the beads through a large and brief pulse of magnetic field and generation of magnetic gradients to produce uniaxial oscillatory forces. By using this two step method, the magnetic moment of the beads remains constant during measurements. Therefore, the applied force can be computed and varies linearly with the driving signal. No feedback control is required to produce well defined force oscillations over a wide bandwidth. The design of the coils was optimized to obtain high magnetic fields (280 mT) and gradients (2 T/m) with high homogeneity (5% variation) within the sample. The magnetic tweezers were implemented in an inverted optical microscope with a videomicroscopy-based multiparticle tracking system. The apparatus was validated with 4.5 ¿m magnetite beads obtaining forces up to ~2 pN and subnanometer resolution. The applicability of the device includes microrheology of biopolymer and cell cytoplasm, molecular mechanics, and mechanotransduction in living cells.

A new estimator to minimize the error due to breathing in the measurement of respiratory impedance

This paper presents a new respiratory impedance estimator to minimize the error due to breathing. Its practical reliability was evaluated in a simulation using realistic signals. These signals were generated by superposing pressure and flow records obtained in two conditions: 1) when applying forced oscillation to a resistance- inertance- elastance (RIE) mechanical model; 2) when healthy subjects breathed through the unexcited forced oscillation generator. Impedances computed (4-32 Hz) from the simulated signals with the new estimator resulted in a mean value which was scarcely biased by the added breathing (errors less than 1 percent in the mean R, I , and E ) and had a small variability (coefficients of variation of R, I, and E of 1.3, 3.5, and 9.6 percent, respectively). Our results suggest that the proposed estimator reduces the error in measurement of respiratory impedance without appreciable extracomputational cost.

Device for simultaneous measurement of the Peltier and Seebeck coefficients verification of the Kelvin relation

We have designed and built an experimental device, which we called a "thermoelectric bridge." Its primary purpose is simultaneous measurement of the relative Peltier and Seebeck coefficients. The systematic errors for both coefficients are equal with this device and manipulation is not necessary between the measurement of one coefficient and the other. Thus, this device is especially suitable for verifying their linear relation postulated by Lord Kelvin. Also, simultaneous measurement of thermal conductivity is described in the text. A sample is made up of the couple nickel¿platinum, taking measurements in the range of ¿20¿60°C and establishing the dependence of each coefficient with temperature, with nearly equal random errors ±0.2%, and systematic errors estimated at ¿0.5%. The aforementioned Kelvin relation is verified in this range from these results, proving that the behavioral deviations are ¿0.3% contained in the uncertainty ±0.5% caused by the propagation of errors

Design of surface forces apparatus for tribology studies combined with nonlinear optical spectroscopy

We describe the design, calibration, and performance of surface forces apparatus with the capability of illumination of the contact interface for spectroscopic investigation using optical techniques. The apparatus can be placed in the path of a Nd-YAG laser for studies of the linear response or the second harmonic and sum-frequency generation from a material confined between the two surfaces. In addition to the standard fringes of equal chromatic order technique, which we have digitized for accurate and fast analysis, the distance of separation can be measured with a fiber-optic interferometer during spectroscopic measurements (2 Å resolution and 10 ms response time). The sample approach is accomplished through application of a motor drive, piezoelectric actuator, or electromagnetic lever deflection for variable degrees of range, sensitivity, and response time. To demonstrate the operation of the instrument, the stepwise expulsion of discrete layers of octamethylcyclotetrasiloxane from the contact is shown. Lateral forces may also be studied by using piezoelectric bimorphs to induce and direct the motion of one surface.

Nonequilibrium patterns and shape fluctuations in reactive membranes

A simple kinetic model of a two-component deformable and reactive bilayer is presented. The two differently shaped components are interconverted by a nonequilibrium reaction, and a phenomenological coupling between local composition and curvature is proposed. When the two components are not miscible, linear stability analysis predicts, and numerical simulations show, the formation of stationary nonequilibrium composition/curvature patterns whose typical size is determined by the reactive process. For miscible components, a linearization of the dynamic equations is performed in order to evaluate the correlation function for shape fluctuations from which the behavior of these systems in micropipet aspiration experiments can be predicted.

Generation of dynamic structures in nonequilibrium reactive membranes

We present a nonequlibrium approach for the study of a flexible bilayer whose two components induce distinct curvatures. In turn, the two components are interconverted by an externally promoted reaction. Phase separation of the two species in the surface results in the growth of domains characterized by different local composition and curvature modulations. This domain growth is limited by the effective mixing due to the interconversion reaction, leading to a finite characteristic domain size. In addition to these effects, first introduced in our earlier work [ Phys. Rev. E 71 051906 (2005)], the important new feature is the assumption that the reactive process actively affects the local curvature of the bilayer. Specifically, we suggest that a force energetically activated by external sources causes a modification of the shape of the membrane at the reaction site. Our results show the appearance of a rich and robust dynamical phenomenology that includes the generation of traveling and/or oscillatory patterns. Linear stability analysis, amplitude equations, and numerical simulations of the model kinetic equations confirm the occurrence of these spatiotemporal behaviors in nonequilibrium reactive bilayers.