885 resultados para Paradigms


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In this essay I will argue that natural selection is more important to functional explanations than what has been thought in some of the literature in philosophy of biology. I start by giving a brief overview of the two paradigms cases of functional explanations: etiological functions and causal-role functions. i then consider one particular attempt to conciliate both perspectives given by David Buller (1998). Buller's trial to conciliate both etiological functions and causal-role functions results in what he calls a weak etiological theory. I argue that Buller has not succeeded in his construal of the weak etiological theory: he underestimates the role that selective processes have in functional explanations and so his theory may not be classified as an etiologial theory. As an alternative, I consider the account of etiological functions given by Ruth Millikan (1984) and I argue that Millikan's theory is more comprehensive to assess contentious case in biology like exaptations. Finally, I conclude by analyzing where the adoption of Millikan's theory leave us. I argue, contrary to Millikan and others, that once we assume the importance of natural selection in functional explanations, there is no strong reason to resist a linguistic reform of the word function and hence that the attempts to conciliate both etiological functions and causal-role functions are misplaced.

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Tausta Suomessa lainsäätäjä reagoi helposti yhteiskunnalliseen häiriötekijään rikosoikeuden keinoin. Tästä on osoituksena se, että syksyllä 2010 varsinaisen rikoslain lisäksi rikoksesta oli säädetty 256 eri laissa. Suomalainen, lähtökohdiltaan maltillinen kontrolli- ja kriminaalipolitiikka on 1970-luvulla linjatun vastaisesti johtanut 2000-luvulle tultaessa rikosoikeudellisen kontrollin lisääntymiseen ja jopa kiristymiseen. Raja rikosten ja rikkomusten välillä on liudentunut ja paikoitellen kadonnut ja erityisesti turvallisuudesta on kehittynyt – käsitteeseen liittyvistä oikeudellisista jännitteistä huolimatta – keskeinen rikosoikeudellisen sääntelyn oikeutusperuste. Rikosoikeuden käyttäminen vähäisten rikosten kontrollointiin on aiheuttanut Suomeen viivästymisen ongelman. Yleisessä tiedossa on se, että Euroopan ihmisoikeustuomioistuin on antanut 2000-luvulla Suomelle kymmeniä tuomioita siksi, että rikosjuttuja on käsitelty viranomaisissa ja tuomioistuimissa liian kauan. Vähemmän on sen sijaan keskusteltu siitä, että myös vähäiset rikokset viivästyvät rikosoikeuden alan laajetessa ja viranomaisten voimavarojen ehtyessä. Suomessa ongelmaa on pyritty hoitamaan rikosoikeudellista toimivaltaa hallintoviranomaisille delegoimalla tilanteen ollessa nyt se, että uuden sakkomenettelylain voimaan tullessa noin 90 % rikosoikeudellisesta kompetenssista on poliisilla ja muilla hallintoviranomaisilla. Se taasen on ongelmallista perustuslain 3 §:ssä säädetyn vallanjakoperiaatteen kannalta. Välttämätöntä on korostaa myös sitä, että pääosin rikosoikeudelliseen kontrolliin perustuva systeemi aiheuttaa rikosoikeuden inflaatiota: rikosoikeuden arvostuksen vähenemisestä aiheutuvia ei-mittavissa olevia kuluja. Rikosoikeuden laajenemista vastaan esitetään kuitenkin harvoin kritiikkiä. Rikosoikeustieteen piirissäkään sille ei ole esitetty vakavasti otettavaa vaihtoehtoa. Esimerkiksi hallinnollisia sanktioita ei ole Suomessa – ei tosin muissa Pohjoismaissakaan – koettu rikosoikeuden vaihtoehtona, vaan usein rikosoikeutta täydentävänä järjestelmänä. Hallinnollisten sanktioiden käyttäminen rikosoikeuden ohessa ei ole ollut yksiselitteistä ja jäsenneltyä, yleisiin oppeihin perustuvaa. Kontrollin erityisille alueille, esimerkiksi sotilaskontrolliin, on lisäksi kehittynyt rikos- ja hallinto-oikeuden sekajärjestelmiä. Tutkimuskysymykset Käsillä olevassa artikkelimuotoisessa väitöskirjatutkimuksessa pyritään hahmottelemaan rikos- ja hallinto-oikeudellisten rangaistusjärjestelmien välisiä eroavaisuuksia Suomessa. Tutkimuksen keskeisin tehtävä on sen pohtiminen, millä tavalla 2010-luvulle tultaessa olisi tutkimuksen empiiriset ja teoreettiset lähtökohdat huomioon ottaen järkevää ja tarkoituksenmukaista rangaista. Tällä perusteella kehitetään yksikertaista hallintosanktiointiteoreettista mallia, että sitä hyväksikäyttäen lainvalmisteluprosessin sanktiointitilanteessa, sanktiosta päätettäessä, olisi mahdollista asettaa oikeusturvan vähimmäistakeet täyttävällä tavalla oikeus- ja muilta vaikutuksiltaan rationaalinen seuraamus sekä säätää sen määräämiseksi yhteiskunnallisilta vaikutuksiltaan tehokas ja riittävän oikeusturvallinen menettely. Tutkimustehtävä on tiivistetysti 1) hallinnollisten sanktioiden ja rikosoikeudellisten rangaistusten ja niiden alan määrittäminen, 2) hallinnollisten sanktioiden sääntelymallien valintaperusteluiden selvittäminen, 3) hallintosanktioteoreettisen mallin kehittäminen lainvalmisteluprosessia varten sekä 4) de lege ferenda -suositusten tekeminen rangaistavuuden hyväksyttävyyden ja joutuisuuden parantamiseksi. Menetelmä ja aineistot Tutkimus kytkeytyy teoreettisen rikosoikeustieteen, hallinto-oikeustieteen ja prosessioikeustieteen alalle ja se on luonteeltaan ongelmakeskeinen. Tieteenalojen väliset painotukset ja niiden vaikutus vaihtelevat tutkimuksessa. Vaikka tutkimus on monella tavalla luonteeltaan teoreettinen, siinä rakennetaan nimenomaan lainsäädäntötyötä ja lainvalmistelua tukevaa tutkimusta ja teoriaa. Tältä osin näkökulma liittyy kriminalisointiteoreettisessa tutkimuksessa hahmotettuun lainsäätäjän oikeuslähdeoppia koskevaan uuteen näkökulmaan, jolla on yhteyksiä lainsäädäntötutkimukseen ja oikeusteoriassa hahmotettuun legisprudence-tutkimusuuntaukseen, näkökulman suuntautuessa lainsäädäntötasolle. Tutkimuksen lähteistä suurin osa on oikeustieteellistä kirjallisuutta, jonka pääosa muotoutuu suomalaisesta oikeustieteellisestä kirjallisuudesta. Myös pohjoismaalaista, saksalaista ja hieman myös anglosaksista kirjallisuutta on käytetty. Kansainvälisten kirjallisuuslähteiden merkitys ei ole ollut merkittävä, koska kattava eurooppalainen näkemys aihepiiristä on pyritty saamaan Euroopan ihmisoikeustuomioistuimen ratkaisukäytäntöä hyödyntäen. Tutkimuksen lähteinä on käytetty laajasti myös kansallista lainvalmisteluaineistoa, erityisesti hallituksen esityksiä ja perustuslakivaliokunnan lausuntokäytäntöä. Johtopäätökset Kriminaali- ja/tai kontrollipolitiikassa on juuri nyt tärkeää pohtia, millä tavalla 2010-luvulle tultaessa on järkevää ja tarkoituksenmukaista rangaista. Tähän voisi olla mahdollista vastata tutkimuksessa kehitettävällä hallintosanktiointiteoreettisella mallilla. Mallin kehittäminen on edellyttänyt yhteiskunnallisten sanktiokäytäntöjen oikeusvaltioopillista tarkastelua, jolloin sanktioiden yhteiskunnalliseen merkitykseen pureutuminen kuvailee myös sitä, millainen modernin oikeusvaltion tila tällä hetkellä on. Perinteisten oikeusvaltioiden paradigmojen käyttäminen ei välttämättä edistä relevantin oikeusvaltiollisen sanktiointiteoreettisen mallin kehittämistä. Voi olla niinkin, että klassinen oikeusvaltio-oppi ja oletetunlaiset rikosoikeuden erityiset elementit eivät enää vastaa yhteiskuntatodellisuutta. Näin rankaisemisen yleiset opit voivat nousta kehittämisen kohteeksi oikeusvaltiollisuuden elementtien toteuttamiseksi valtavasta kasvaneessa hallintoyhteiskunnassa – hallinto-johtoisessa yhteiskunnallisessa todellisuudessa. Suomen rikoslaki sisältää laajassa merkityksessä sadoittain erilaatuisia kriminalisointeja, joiden merkitys on usein hallinnon toimintaa subventoiva, symbolinen tai jonkin toisen kriminalisoinnin vaikutusta tehostamaan pyrkivä. Tällainen rikoslaki on tehtävänsä, vaikuttavuutensa ja hyväksyttävyytensä kannalta ongelmallinen. Suomalainen hallinnollisten sanktioiden järjestelmä ei sekään ole järkevä ja tarkoituksenmukainen, yleisiin oppeihin perustuva systeemi. Myös yleiseurooppalainen kehitys näyttäisi viittaavan siihen, että Suomessa on tarve kehittää sekä rikosoikeutta että sille vaihtoehtoista hallintosanktioiden järjestelmää, sanktio-oikeutta. Tämä edellyttää lainsäädäntöuudistuksia.

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Japan has been a major actor in the field of development cooperation for five decades, even holding the title of largest donor of Official Development Assistance (ODA) during the 1990s. Financial flows, however, are subject to pre-existing paradigms that dictate both donor and recipient behaviour. In this respect Japan has been left wanting for more recognition. The dominance of the so called ‘Washington Consensus’ embodied in the International Monetary Fund (IMF) and the World Bank has long circumvented any indigenous approaches to development problems. The Tokyo International Conference on African Development (TICAD) is a development cooperation conference that Japan has hosted since 1993 every five years. As the main organizer of the conference Japan has opted for the leading position of African development. This has come in the wake of success in the Asian region where Japan has called attention to its role in the so called ‘Asian Miracle’ of fast growing economies. These aspirations have enabled Japan to try asserting itself as a major player in directing the course of global development discourse using historical narratives from both Asia and Africa. Over the years TICAD has evolved into a continuous process with ministerial and follow-up meetings in between conferences. Each conference has produced a declaration that stipulates the way the participants approach the question of African development. Although a multilateral framework, Japan has over the years made its presence more and more felt within the process. This research examines the way Japan approaches the paradigms of international development cooperation and tries to direct them in the context of the TICAD process. Supplementing these questions are inquiries concerning Japan’s foreign policy aspirations. The research shows that Japan has utilized the conference platform to contest other development actors and especially the dominant forces of the IMF and the World Bank in development discourse debate. Japan’s dominance of the process is evident in the narratives found in the conference documents. Relative success has come about by remaining consistent as shown by the acceptance of items from the TICAD agenda in other forums, such as the G8. But the emergence of new players such as China has changed the playing field, as they are engaging other developing countries from a more equal level.

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Recent progress in gastrointestinal stromal tumor's (GIST) treatment were responsible for changing GIST's natural history. Knowlegde acquirement of molecular mechanism-based systemic therapy gave rise to the development of targeted antineoplastic drugs capable of reaching outcomes that had never been reached before. The introduction of imatinib in the clinical practice not only changed GIST's patients survival but also shifted paradigms. However, besides all these new advances and the improved results with imatinib, the surgeon still plays a pivotal role in the management of the primary GIST tumor and even in the metastatic setting.

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Complex System is any system that presents involved behavior, and is hard to be modeled by using the reductionist approach of successive subdivision, searching for ''elementary'' constituents. Nature provides us with plenty of examples of these systems, in fields as diverse as biology, chemistry, geology, physics, and fluid mechanics, and engineering. What happens, in general, is that for these systems we have a situation where a large number of both attracting and unstable chaotic sets coexist. As a result, we can have a rich and varied dynamical behavior, where many competing behaviors coexist. In this work, we present and discuss simple mechanical systems that are nice paradigms of Complex System, when they are subjected to random external noise. We argue that systems with few degrees of freedom can present the same complex behavior under quite general conditions.

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The zebrafish (Danio rerio) has been used as a model in neuroscience but knowledge about its behavior is limited. The aim of this study was to determine the preference of this fish species for a dark or light environment. Initially we used a place preference test and in a second experiment we applied an exit latency test. A two-chamber aquarium was used for the preference test. The aquarium consisted of a black chamber and a white chamber. In the first experiment the animal was placed in the aquarium and the time spent in the two compartments was recorded for 10 min. More time was spent in the black compartment (Wilcoxon matched-pairs signed-rank test, T = 7, N1 = N2 = 18, P = 0.0001). In the second experiment the animal was placed in the black or white compartment and the time it took to go from the initial compartment to the opposite one was recorded. The test lasted a maximum of 10 min. The results showed that the animal spent more time to go from the black to the white compartment (Mann-Whitney rank sum test, T = 48, N1 = 9, N2 = 8, P<0.0230). These data suggest that this fish species has a natural preference for a dark environment and this characteristic can be very useful for the development of new behavioral paradigms for fish.

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In this work, the feasibility of the floating-gate technology in analog computing platforms in a scaled down general-purpose CMOS technology is considered. When the technology is scaled down the performance of analog circuits tends to get worse because the process parameters are optimized for digital transistors and the scaling involves the reduction of supply voltages. Generally, the challenge in analog circuit design is that all salient design metrics such as power, area, bandwidth and accuracy are interrelated. Furthermore, poor flexibility, i.e. lack of reconfigurability, the reuse of IP etc., can be considered the most severe weakness of analog hardware. On this account, digital calibration schemes are often required for improved performance or yield enhancement, whereas high flexibility/reconfigurability can not be easily achieved. Here, it is discussed whether it is possible to work around these obstacles by using floating-gate transistors (FGTs), and analyze problems associated with the practical implementation. FGT technology is attractive because it is electrically programmable and also features a charge-based built-in non-volatile memory. Apart from being ideal for canceling the circuit non-idealities due to process variations, the FGTs can also be used as computational or adaptive elements in analog circuits. The nominal gate oxide thickness in the deep sub-micron (DSM) processes is too thin to support robust charge retention and consequently the FGT becomes leaky. In principle, non-leaky FGTs can be implemented in a scaled down process without any special masks by using “double”-oxide transistors intended for providing devices that operate with higher supply voltages than general purpose devices. However, in practice the technology scaling poses several challenges which are addressed in this thesis. To provide a sufficiently wide-ranging survey, six prototype chips with varying complexity were implemented in four different DSM process nodes and investigated from this perspective. The focus is on non-leaky FGTs, but the presented autozeroing floating-gate amplifier (AFGA) demonstrates that leaky FGTs may also find a use. The simplest test structures contain only a few transistors, whereas the most complex experimental chip is an implementation of a spiking neural network (SNN) which comprises thousands of active and passive devices. More precisely, it is a fully connected (256 FGT synapses) two-layer spiking neural network (SNN), where the adaptive properties of FGT are taken advantage of. A compact realization of Spike Timing Dependent Plasticity (STDP) within the SNN is one of the key contributions of this thesis. Finally, the considerations in this thesis extend beyond CMOS to emerging nanodevices. To this end, one promising emerging nanoscale circuit element - memristor - is reviewed and its applicability for analog processing is considered. Furthermore, it is discussed how the FGT technology can be used to prototype computation paradigms compatible with these emerging two-terminal nanoscale devices in a mature and widely available CMOS technology.

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This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC). Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical) properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps.

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Simple manual reaction time (MRT) to a visual target (S2) is shortened when a non-informative cue (S1) is flashed at the S2 location shortly before the onset of S2 (early facilitation). Afterwards, MRT to S2 appearing at the S1 location is lengthened (inhibition of return - IOR). Similar results have been obtained for saccadic reaction time (SRT). Moreover, when there is a temporal gap between offset of the fixation point (FP) and onset of a target (gap paradigm), SRT is shorter than SRT in an overlap paradigm (FP remains on). In the present study, we determined SRT to S2 (10º) after presenting S1 at the same eccentricity (10º) or at a parafoveal position (2º) in the same or in the opposite hemifield. In addition, we employed both gap and overlap paradigms. Twelve subjects were asked not to respond to S1 (2º or 10º) to the right or to the left of FP, but to respond by making a saccadic movement in response to S2. We obtained the following results: 1) a 40-ms gap effect, 2) an interaction between gap effect and IOR, 3) a 39-ms delay (IOR) when S2 appeared at the cued (S1) position, and 4) a smaller (17 ms) but significant inhibition when S1 occurred at 2º in the ipsilateral hemifield. Thus, a parafoveal (2º) S1 elicits an inhibition of SRT towards ipsilateral peripheral targets. Since an inhibition of the ipsilateral hemifield by a 1º eccentric cue has been reported to occur when manual responses are employed, we suggest that the postulated functional link between covert and overt orienting of attention is also valid for parafoveal cues.

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This review addresses the mechanisms of methylmercury (MeHg)-induced neurotoxicity, specifically examining the role of oxidative stress in mediating neuronal damage. A number of critical findings point to a central role for astrocytes in mediating MeHg-induced neurotoxicity as evidenced by the following observations: a) MeHg preferentially accumulates in astrocytes; b) MeHg specifically inhibits glutamate uptake in astrocytes; c) neuronal dysfunction is secondary to disturbances in astrocytes. The generation of reactive oxygen species (ROS) by MeHg has been observed in various experimental paradigms. For example, MeHg enhances ROS formation both in vivo (rodent cerebellum) and in vitro (isolated rat brain synaptosomes), as well as in neuronal and mixed reaggregating cell cultures. Antioxidants, including selenocompounds, can rescue astrocytes from MeHg-induced cytotoxicity by reducing ROS formation. We emphasize that oxidative stress plays a significant role in mediating MeHg-induced neurotoxic damage with active involvement of the mitochondria in this process. Furthermore, we provide a mechanistic overview on oxidative stress induced by MeHg that is triggered by a series of molecular events such as activation of various kinases, stress proteins and other immediate early genes culminating in cell damage.

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Happy emotional states have not been extensively explored in functional magnetic resonance imaging studies using autobiographic recall paradigms. We investigated the brain circuitry engaged during induction of happiness by standardized script-driven autobiographical recall in 11 healthy subjects (6 males), aged 32.4 ± 7.2 years, without physical or psychiatric disorders, selected according to their ability to vividly recall personal experiences. Blood oxygen level-dependent (BOLD) changes were recorded during auditory presentation of personal scripts of happiness, neutral content and negative emotional content (irritability). The same uniform structure was used for the cueing narratives of both emotionally salient and neutral conditions, in order to decrease the variability of findings. In the happiness relative to the neutral condition, there was an increased BOLD signal in the left dorsal prefrontal cortex and anterior insula, thalamus bilaterally, left hypothalamus, left anterior cingulate gyrus, and midportions of the left middle temporal gyrus (P < 0.05, corrected for multiple comparisons). Relative to the irritability condition, the happiness condition showed increased activity in the left insula, thalamus and hypothalamus, and in anterior and midportions of the inferior and middle temporal gyri bilaterally (P < 0.05, corrected), varying in size between 13 and 64 voxels. Findings of happiness-related increased activity in prefrontal and subcortical regions extend the results of previous functional imaging studies of autobiographical recall. The BOLD signal changes identified reflect general aspects of emotional processing, emotional control, and the processing of sensory and bodily signals associated with internally generated feelings of happiness. These results reinforce the notion that happiness induction engages a wide network of brain regions.

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Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

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There has been concern regarding the use of controversial paradigms for repetitive transcranial magnetic stimulation (rTMS) to manage treatment-resistant depression (TRD). This meta-analysis assessed the efficacy of bilateral rTMS compared with unilateral and sham rTMS in patients with TRD. PubMed, Embase, CENTRAL, PsycINFO, Web of Science, EAGLE and NTIS databases were searched to identify relevant studies, and randomized controlled trials (RCTs) on bilateral rTMS for TRD patients were included. The response was defined as the primary outcome, and remission was the secondary outcome. Ten RCTs that included 634 patients met the eligibility criteria. The risk ratio (RRs) of both the primary and secondary outcomes of bilateral rTMS showed non-significant increases compared to unilateral rTMS (RR=1.01, P=0.93; odds ratio [OR]=0.77, P=0.22). Notably, the RR of the primary bilateral rTMS outcome was significantly increased compared to that for sham rTMS (RR=3.43, P=0.0004). The results of our analysis demonstrated that bilateral rTMS was significantly more effective than sham rTMS but not unilateral rTMS in patients with TRD. Thus, bilateral rTMS may not be a useful paradigm for patients with TRD.

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Enzyme technology is an ever-growing field of knowledge and, in recent years, this technology has raised renewed interest, due to the search for new paradigms in several productive processes. Lipases, esterases and cutinases are enzymes used in a wide range of processes involving synthesis and hydrolysis reactions. The objective of this work was to investigate and compare the specific lipase and esterase activities of five enzymes - four already classified as lipases and one classified as cutinase - in the presence of natural and synthetic substrates. All tested enzymes presented both esterase and lipase specific activities. The highest specific esterase activity was observed for Aspergillus 1068 lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate, while the highest specific lipase activity was observed for Geotrichum sp. lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate. These results display some interface-independent lipolytic activity for all lipases tested. This is in accordance with the rationale that a new and broader definition of lipases may be necessary.