A pilot study on quantification of training load: The use of HRV in training practice.

Recent laboratory studies have suggested that heart rate variability (HRV) may be an appropriate criterion for training load (TL) quantification. The aim of this study was to validate a novel HRV index that may be used to assess TL in field conditions. Eleven well-trained long-distance male runners performed four exercises of different duration and intensity. TL was evaluated using Foster and Banister methods. In addition, HRV measurements were performed 5 minutes before exercise and 5 and 30 minutes after exercise. We calculated HRV index (TLHRV) based on the ratio between HRV decrease during exercise and HRV increase during recovery. HRV decrease during exercise was strongly correlated with exercise intensity (R = -0.70; p < 0.01) but not with exercise duration or training volume. TLHRV index was correlated with Foster (R = 0.61; p = 0.01) and Banister (R = 0.57; p = 0.01) methods. This study confirms that HRV changes during exercise and recovery phase are affected by both intensity and physiological impact of the exercise. Since the TLHRV formula takes into account the disturbance and the return to homeostatic balance induced by exercise, this new method provides an objective and rational TL index. However, some simplification of the protocol measurement could be envisaged for field use.

Uso del fuego prescrito para la creación de rodales cortafuegos: estudio del caso de Las Mesas de Ana López, Vega de San Mateo, Gran Canaria (España)

Los regímenes de fuegos forestales están cambiando en Gran Canaria y los grandes incendios forestales son más probables que antiguamente. Esto es un cambio importante en el régimen de perturbaciones y una grave amenaza a la biodiversidad. El Plan de Prevención de Incendios Forestales de Gran Canaria, año 2002 dejó clara la obligación de cambiar las estructuras de vegetación de la Isla en dos ámbitos: paisaje y protección de zonas sensibles. El uso de fuego prescrito (años 2002-2005) ha resultado ser una herramienta especialmente eficiente en este ámbito y muy adecuada para compatibilizar las acciones de prevención de incendios con el mantenimiento de los procesos ecológicos. Estas primeras experiencias en Gran Canaria muestran la idoneidad de los tratamientos para establecer rodales resistentes al paso del fuego en zonas estratégicas (deducidas tras simulación con Farsite y FlamMap). Y revelan lo conveniente que es que estos rodales resistentes estén distribuidos por nuestros montes de modo que los incendios potencialmente grandes encuentren zonas en las que sea factible controlar los perímetros. Este control se pudo hacer eficientemente en el incendio de las Mesas de 17 de agosto de 2004.

Design and implementation of FPGA-based LQ control of active magnetic bearings

The need for high performance, high precision, and energy saving in rotating machinery demands an alternative solution to traditional bearings. Because of the contactless operation principle, the rotating machines employing active magnetic bearings (AMBs) provide many advantages over the traditional ones. The advantages such as contamination-free operation, low maintenance costs, high rotational speeds, low parasitic losses, programmable stiffness and damping, and vibration insulation come at expense of high cost, and complex technical solution. All these properties make the use of AMBs appropriate primarily for specific and highly demanding applications. High performance and high precision control requires model-based control methods and accurate models of the flexible rotor. In turn, complex models lead to high-order controllers and feature considerable computational burden. Fortunately, in the last few years the advancements in signal processing devices provide new perspective on the real-time control of AMBs. The design and the real-time digital implementation of the high-order LQ controllers, which focus on fast execution times, are the subjects of this work. In particular, the control design and implementation in the field programmable gate array (FPGA) circuits are investigated. The optimal design is guided by the physical constraints of the system for selecting the optimal weighting matrices. The plant model is complemented by augmenting appropriate disturbance models. The compensation of the force-field nonlinearities is proposed for decreasing the uncertainty of the actuator. A disturbance-observer-based unbalance compensation for canceling the magnetic force vibrations or vibrations in the measured positions is presented. The theoretical studies are verified by the practical experiments utilizing a custom-built laboratory test rig. The test rig uses a prototyping control platform developed in the scope of this work. To sum up, the work makes a step in the direction of an embedded single-chip FPGA-based controller of AMBs.

A Spanish version of the athens insomnia scale

Objectives To develop and validate a Spanish version of the Athens Insomnia Scale (AIS). Methods The AIS is designed to assess sleep difficulty and comprises eight items: the first five refer to the sleep disturbance and the last three to the daytime consequences. Either the full eight-item scale (AIS-8) or the brief form (AIS-5) can be administered. The adaptation used a backtranslation design. The validation process was based on a sample of 323 participants (undergraduates, community sample and psychiatric outpatients), which completed the AIS and other questionnaires: anxiety (BAI), depression (BDI) and psychological well-being (GHQ-12) scales. Results The internal consistency coefficients for both versions were above 0.80. The study of dimensionality revealed a single factor with high loadings and a percentage of explained variance above 50% in both versions. Test-retest reliability was above 0.70 (AIS-5) and over 0.80 (AIS-8) at a one-month interval. The correlation between the AIS and the previously mentioned scales was for both the AIS-5 and the AIS-8 above 0.40 and 0.50, respectively.

Sahalaitosten häiriömittauskäytännön yhtenäistäminen

Työn tavoitteena oli selvittää kahdeksan sahalaitoksen häiriöseurannan nykytila sekä selvittämisen jälkeen ehdottaa sahalaitoksille otettavaksi käyttöön yhtenäinen samoihin häiriön luokitus- ja kirjaamisperiaatteisiin perustuva mittauskäytäntö. Yhtenäisen käytännön myötä sahalaitoksilta saatavat häiriötiedot ovat sahalaitosten kesken vertailukelpoisia. Mittauskäytännön yhtenäistämisellä pyritään nostamaan tuotantolinjojen käytettävyyttä. Sahalaitosten häiriömittauskäytännöissä oletettiin olevan merkittäviä eroja. Työ suoritettiin lähettämällä kysymykset sähköpostilla etukäteen sahalaitoksille, jonka jälkeen käytiin sahalaitoksissa haastattelemassa häiriöasioiden kanssa tekemisissä olevia henkilöitä. Haastattelujen jälkeen sahalaitoksilta saatuja tietoja täydennettiin sähköpostin välityksellä. Näiden toimintatapojen lisäksi tutkittiin sahalaitoksilta saatuja häiriöraportteja ja syykoodilistoja sekä verrattiin tutkimuksessa satuja tuloksia aihetta käsittelevään kirjallisuuteen. Tutkimustulokset vahvistavat työn aloitusvaiheessa tehdyn oletuksen, jonka mukaan sahalaitosten häiriömittauskäytännöissä on merkittäviä eroja. Tutkimusta hyödyntäen asiantuntijatyöryhmä yhtenäisti sahalinjojen ja tasaamoiden pien-häiriöiden ja varsinaisten häiriöiden laukaisurajat sekä häiriöiden mittauspaikat. Myös syykoodilistat yhtenäistettiin. Tämän lisäksi muodostettiin yhtenäinen vertailuraportti, jotta sahalaitosten häiriötietojen vertaileminen on mahdollista.

Syöttöjännitteen jännitehäiriöt paperikoneen sähkökäytössä

Diplomityön tavoitteena oli selvittää paperikonelinjakäyttöjen toimintaa syöttöjännitteen alenemien ja –jännitekatkojen aikana. Työssä haluttiin selvittää, millaisista häiriöistä laitteistot selviävät pysähtymättä ja kuinka laitteistojen immuniteettia häiriöille voitaisiin parantaa. Standardien esittämien jännitehäiriöiden siedon vaatimuksien lisäksi haluttiin selvittää olosuhteet, joissa asiakkaiden sähkökäytöt tulisi toimia. Näiden ongelmien ratkaisemiseksi selvitettiin laboratoriomittauksin tyristori- ja ISU –syöttöyksiköillä varustettujen linjakäyttöjen testilaitteistojen ominaisuuksia jännitteen alenemien aikana. Lisäksi selvitettiin paperikoneen muiden laitteistojen toimintaa jännitehäiriöiden aikana. Avain sähkökäyttöjen jännitehäiriöiden siedon parantamiseksi löytyy ulkoisista energiavarastoista ja paperikoneen linjakäyttöjen hallitusta ohjaamisesta häiriöiden aikana. Näiden hyödyntäminen edellyttää kuitenkin työssä selvitetyn paperiprosessin ohjauksen tuntemista ratakatkon aikana.

Benthos of Spanish lakes and reservoirs

A summary of the results from the study of benthos of lakes and reservoirs in Spain is provided, with a list of the species found to date. Spanish natural lakes are smaller than European lakes; the largest is Lake Sanabria, of glacial origin, which is 3 Km long and half a kilorneter wide. Many are very small and situated in the mountains; more than 200 hundred have been recorded in Spain, but only in Lake Sanabria and Lake Banyoles have the benthos been studied. Lake Sanabria is a cold oligotrophic, monomictic lake with oxygen always present in the deepest zones. Its fauna is similar to that of other central European lakes, with Mici.opsectra c.orztractu (a chironomid) as the dominan1 species. Lake Banyoles is a karstic, monomictic and multibasin lake; despite the low primary productivity, due to the abundante of sulphate in the water, the allochthonous inflow of organic matter and the inflow of water from bottom springs, the profunda1 environinent is very stressing for benthic fauna. Very low oxygen concentrations and high sulphide content in the water and sediments dueto meromixis mean that only the larva of the dipteran Chaohoi.lcs flai7icans was present in one of the 5 basins of the lake. In other basins, when oxygen is available (no meromixis), the fauna is similar to that of tlie inineralized lakes of the Aegean region and some lakes in central Italia. On the other hand, preliminary data from the Pyrenean lakes and from Sierra Nevada ponds reveal no differences with northern cold lakes. Tlie largest lakes in Spain are the reservoirs. There are nearly 1000 and data are available on 100 of them, including the kargest. In addition to oxygen and sulphide content in the bottom waters, water level fluctuation and high sedimentation rates are disturbance factors that prevented the organization of the community. Allochthonous inputs of organic matter are also an important factor both in the reservoirs and also in the small, oligotrophic lakes like Banyoles and Sanabria. As a result the meiofaunal loop is very important in many of the Spanish water bodies . For this reason the natural lakes and reservoirs of Spain are dominated by Oligochaeta, small crustaceans and the microcarnivore chironomids (such as Procladi~ls, Cladopelma and Mi(,rnc.hil-onnmus) that feed on these meoifaunal elements. The phytophagous chironomids, like Chironomus, are only abundan1 in the shallow areas of mesotrophic and eutrophic reservoirs. This situation makes it difficult to apply the typological system of SAETHER which predicts with some confidence only the benthic communities of Spanish natural lakes above 1500 m in the Pyrenees or the ponds above 2000 m in Sierra Nevada mountains. Higher temperatures (which originate a longer stratification period), the presence of sulphate in the waters of the eastern part of Spain and high inputs of sediments and allochthonous organic matter seem to be the factors that originated the differences between the benthic profunda1 faunas of Spanish lakes and reservoirs and those of the temperate lakes of north and central Europe.

Absorbex®-linjan tehokkuuden parantaminen

Laminating Papers Oy:n PK1 Absorbex®-linjan lajivalikoima on erittäin suuri. Johtuen laajasta lajivalikoimasta ja pienestä keskimääräisestä tilauskoosta, tehdään PK1:llä useita lajinvaihtoja päivässä. Diplomityön tavoitteena oli parantaa tehokkuutta rationalisoimalla lajivalikoimaa ja kehittämällä lajinvaihtoprosessia. Työn kirjallisuusosassa esitettiin Absorbex®-paperin valmistus, sekä paperilta vaaditut laatuominaisuudet. Lisäksi esitettiin paperin impregnointi ja loppukäyttö laminaatin runkopaperina. Kirjallisuusosassa käsiteltiin myös paperikonelinjan tuottavuutta ja tehokkuutta, sekä niiden yhteyttä kannattavuuteen, laatuun ja Laminating Papers Oy:n strategian toteuttamiseen. Lisäksi käsiteltiin paperikoneen tehokkuutta ja sen mittaamista hyötysuhteilla.Kokeellisessa osassa tehtiin alustava selvitys PK1:n kokonaishyötysuhteeseen vaikuttavista tekijöistä. Selvityksen mukaan PK1:n kokonaishyötysuhde on heikko johtuen suuresta hylyn määrästä. Hylky muodostuu pääasiassa lajinvaihtohylystä ja pituusleikkauksen leveyshäviöstä. Kokonaishyötysuhteen parantamiseksi pitää lajivalikoimaa saada pienemmäksi. Lajivalikoiman rationalisoimiseksi poistettiin valikoimasta lajit, joita asiakas ei enää tilaa, sekä pyrittiin yhdistämään laatuominaisuuksiltaan lähellä toisiaan olevia lajeja. Lisäksi tuotannollisesti hankalat lajit pyrittiin poistamaan tai muuttamaan laatuspesifikaatiota edulliseksi. Lajivalikoiman hallitsemiseksi tulevaisuudessa kehitettiin työohje lajien rationalisoinnista ja määriteltiin PK1:n ihanne lajivalikoiman laatualueet. Lajinvaihto prosessia tutkittiin automaattisen lajinvaihdon ja operaattorien toiminnan osalta. Automaattisen lajinvaihdon toimintakyky selvitettiin erityisessä kartoitustutkimuksessa ja operaattorien suoritukselle pyrittiin löytämään paras mahdollinen toimitapa. Lajivalikoiman rationalisoinnissa on suuri potentiaali tehokkuuden parantamiseksi. Ihanne lajivalikoimaan päästäessä saadaan pelkästään lajinvaihtohylyn vähenemisen kautta kokonaishyötysuhdetta nostettua noin kaksi prosenttiyksikköä. Potentiaalin hyödyntäminen vaatii pitkäjänteistä yhteistyötä ja säännöllistä seurantaa tuotannon, teknisen asiakaspalvelun, myynnin ja markkinoinnin kesken. Automaattisen lajinvaihdon häiriötön toiminta edellyttää huolellista käyttöä ja säännöllistä ylläpitoa. Lajinvaihto voidaan suorittaa tehokkaasti käyttämällä aina parhaiksi havaittuja toimitapoja.

Polttolaitosten päästöjen viranomaisraportoinnin uudistaminen

EU:n suurten polttolaitosten direktiivi (2001/80/EY) sekä jätteenpolttodirektiivi (2000/76/EY) aiheuttavat lähivuosina oleellisia muutoksia polttolaitosten päästöjen tarkkailuun. Nämä direktiivit on pantu täytäntöön Suomen lainsäädännössä vastaavina asetuksina. Tässä diplomityössä selvitettiin, mitä muutoksia uudistunut lainsäädäntö tuo polttolaitosten päästölaskentaan ja viranomaisraportointiin. Suurimpia muutoksia ovat päästöjen tarkkailujaksojen lyhentyminen, raja-arvojen tulkinnan muuttuminen, häiriö- sekä ylös- ja alasajojaksojen jättäminen pois pitoisuusraja-arvojen tarkkailusta sekä siirtyminen ominaispäästöjen (mg/MJ) laskennasta pitoisuusarvojen (mg/m3n) laskentaan. Päästötietojen raportoinnissa on huomioitava, että ympäristöhallinnon tavoitteena on siirtyä sähköisesti tapahtuvaan tiedonsiirtoon ja kuukausittain tapahtuvaan raportointiin kaikkien tarkkailtavien päästöjen osalta. Uudistunut ympäristölainsäädäntö koskee jo eräitä polttolaitoksia ja lopuillekin uudistuneet vaatimukset astuvat voimaan lähivuosien aikana. LCP-asetus koskee uusia laitoksia heti, olemassa oleville laitoksille uudet mittausvelvoitteet astuvat voimaan 27.11.2004 ja asetuksen mukaiset raja-arvot 1.1.2008 alkaen. Samoin jätteenpolttoasetus koskee uusia laitoksia heti, käytössä oleville laitoksille se astuu voimaan 29.12.2005. Ensimmäisen ympäristöluvan myöntämisajankohta määrää, luetaanko laitos uusiin vai olemassa tai käytössä oleviin laitoksiin. LCP-asetuksessa uusien ja olemassa olevien laitosten päästöjen tarkkailu poikkeaa hieman toisistaan. Jätteenpoltto- ja rinnakkaispolttolaitoksilla päästöjen tarkkailun toteutustapa puolestaan riippuu poltettavan jätteen laadusta ja sen määrän suhteesta muuhun polttoaineeseen. Lisäksi tämän diplomityöprojektin aikana laadittiin yksityiskohtaiset toteutusohjeet polttolaitoksia koskevan uudistuneen ympäristölainsäädännön mukaiselle päästöjen tarkkailulle ja raportoinnille. Ohjeet laadittiin erikseen LCP- ja jätteenpolttoasetusten soveltamiseksi sekä CO2-päästöjen määrittämistä varten. Ohjeita ei ole sisällytetty tähän työhön, vaan niitä kannattaa tiedustella Kontram Oy:ltä, mikäli niihin halutaan tutustua tarkemmin.

Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings.

Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is considered beneficial and helps an animal to redirect energy and behaviour to cope with a critical situation. However, a long-term increase of glucocorticoids can impair e.g. growth and immune functions. We investigated how nestling barn owls (Tyto alba) are affected by the surrounding landscape and by human activities around their nest sites. We studied these effects on two response levels: (a) the physiological level of the hypothalamus-pituitary-adrenal axis, represented by baseline concentrations of corticosterone and the concentration attained by a standardized stressor; (b) fitness parameters: growth of the nestlings and breeding performance. Nestlings growing up in intensively cultivated areas showed increased baseline corticosterone levels late in the season and had an increased corticosterone release after a stressful event, while their body mass was decreased. Nestlings experiencing frequent anthropogenic disturbance had elevated baseline corticosterone levels, an increased corticosterone stress response and a lower body mass. Finally, breeding performance was better in structurally more diverse landscapes. In conclusion, anthropogenic disturbance affects offspring quality rather than quantity, whereas agricultural practices affect both life history traits.

The Mediterranean benthic herbivores show diverse responses to extreme storm disturbances

Catastrophic storms have been observed to be one of the major elements in shaping the standing structure of marine benthic ecosystems. Yet, little is known about the effect of catastrophic storms on ecosystem processes. Specifically, herbivory is the main control mechanism of macrophyte communities in the Mediterranean, with two main key herbivores: the sea urchin Paracentrotus lividus and the fish Sarpa salpa. Consequently, the effects of extreme storm events on these two herbivores (at the population level and on their behaviour) may be critical for the functioning of the ecosystem. With the aim of filling this gap, we took advantage of two parallel studies that were conducted before, during and after an unexpected catastrophic storm event. Specifically, fish and sea urchin abundance were assessed before and after the storm in monitored fixed areas (one site for sea urchin assessment and 3 sites for fish visual transects). Additionally, we investigated the behavioural response to the disturbance of S. salpa fishes that had been tagged with acoustic transmitters. Given their low mobility, sea urchins were severely affected by the storm (ca. 50% losses) with higher losses in those patches with a higher density of sea urchins. This may be due to a limited availability of refuges within each patch. In contrast, fish abundance was not affected, as fish were able to move to protected areas (i.e. deeper) as a result of the high mobility of this species. Our results highlight that catastrophic storms differentially affect the two dominant macroherbivores of rocky macroalgal and seagrass systems due to differences in mobility and escaping strategies. This study emphasises that under catastrophic disturbances, the presence of different responses among the key herbivores of the system may be critical for the maintenance of the herbivory function.

Nutrient enrichment and water depth modify consumer control in rocky shore macroalgal communities

The objective of my thesis is to assess mechanisms of ecological community control in macroalgal communities in the Baltic Sea. In the top-down model, predatory fish feed on invertebrate mesograzers, releasing algae partly from grazing pressure. Such a reciprocal relationship is called trophic cascade. In the bottom-up model, nutrients increase biomass in the food chain. The nutrients are first assimilated by algae and, via food chain, increase also abundance of grazers and predators. Previous studies on oceanic shores have described these two regulative mechanisms in the grazer - alga link, but how they interact in the trophic cascades from fish to algae is still inadequately known. Because the top-down and bottom-up mechanisms are predicted to depend on environmental disturbances, such as wave stress and light, I have studied these models at two distinct water depths. There are five factorial field experiments behind the thesis, which were all conducted in the Finnish Archipelago Sea. In all the experiments, I studied macroalgal colonization - either density, filament length or biomass - on submerged colonization substrates. By excluding predatory fish and mesograzers from the algal communities, the studies compared the strength of the top-down control to natural algal communities. A part of the experimental units were, in addition, exposed to enriched nitrogen and phosphorus concentrations, which enabled testing of bottom-up control. These two models of community control were further investigated in shallow (<1 m) and deep (ca. 3 m) water. Moreover, the control mechanisms were also expected to depend on grazer species. Therefore different grazer species were enclosed into experimental units and their impacts on macroalgal communities were followed specifically. The community control in the Baltic rocky shores was found to follow theoretical predictions, which have not been confirmed by field studies before. Predatory fish limited grazing impact, which was seen as denser algal communities and longer algal filaments. Nutrient enrichment increased density and filament length of annual algae and, thus, changed the species composition of the algal community. The perennial alga Fucus vesiculosusA and the red alga Ceramium tenuicorne suffered from the increased nutrient availabilities. The enriched nutrient conditions led to denser grazer fauna, thereby causing strong top-down control over both the annual and perennial macroalgae. The strength of the top-down control seemed to depend on the density and diversity of grazers and predators as well as on the species composition of macroalgal assemblages. The nutrient enrichment led to, however, weaker limiting impact of predatory fish on grazer fauna, because fish stocks did not respond as quickly to enhanced resources in the environment as the invertebrate fauna. According to environmental stress model, environmental disturbances weaken the top-down control. For example, on a wave-exposed shore, wave stress causes more stress to animals close to the surface than deeper on the shore. Mesograzers were efficient consumers at both the depths, while predation by fish was weaker in shallow water. Thus, the results supported the environmental stress model, which predicts that environmental disturbance affects stronger the higher a species is in the food chain. This thesis assessed the mechanisms of community control in three-level food chains and did not take into account higher predators. Such predators in the Baltic Sea are, for example, cormorant, seals, white-tailed sea eagle, cod and salmon. All these predatory species were recently or are currently under intensive fishing, hunting and persecution, and their stocks have only recently increased in the region. Therefore, it is possible that future densities of top predators may yet alter the strengths of the controlling mechanisms in the Baltic littoral zone.

Water availability predicts forest canopy height at the global scale.

The tendency of trees to grow taller with increasing water availability is common knowledge. Yet a robust, universal relationship between the spatial distribution of water availability and forest canopy height (H) is lacking. Here, we created a global water availability map by calculating an annual budget as the difference between precipitation (P) and potential evapotranspiration (PET) at a 1-km spatial resolution, and in turn correlated it with a global H map of the same resolution. Across forested areas over the globe, Hmean increased with P-PET, roughly: Hmean (m) = 19.3 + 0.077*(P-PET). Maximum forest canopy height also increased gradually from ~ 5 to ~ 50 m, saturating at ~ 45 m for P-PET > 500 mm. Forests were far from their maximum height potential in cold, boreal regions and in disturbed areas. The strong association between forest height and P-PET provides a useful tool when studying future forest dynamics under climate change, and in quantifying anthropogenic forest disturbance.

What can ecosystems learn? Expanding evolutionary ecology with learning theory.

BACKGROUND: The structure and organisation of ecological interactions within an ecosystem is modified by the evolution and coevolution of the individual species it contains. Understanding how historical conditions have shaped this architecture is vital for understanding system responses to change at scales from the microbial upwards. However, in the absence of a group selection process, the collective behaviours and ecosystem functions exhibited by the whole community cannot be organised or adapted in a Darwinian sense. A long-standing open question thus persists: Are there alternative organising principles that enable us to understand and predict how the coevolution of the component species creates and maintains complex collective behaviours exhibited by the ecosystem as a whole? RESULTS: Here we answer this question by incorporating principles from connectionist learning, a previously unrelated discipline already using well-developed theories on how emergent behaviours arise in simple networks. Specifically, we show conditions where natural selection on ecological interactions is functionally equivalent to a simple type of connectionist learning, 'unsupervised learning', well-known in neural-network models of cognitive systems to produce many non-trivial collective behaviours. Accordingly, we find that a community can self-organise in a well-defined and non-trivial sense without selection at the community level; its organisation can be conditioned by past experience in the same sense as connectionist learning models habituate to stimuli. This conditioning drives the community to form a distributed ecological memory of multiple past states, causing the community to: a) converge to these states from any random initial composition; b) accurately restore historical compositions from small fragments; c) recover a state composition following disturbance; and d) to correctly classify ambiguous initial compositions according to their similarity to learned compositions. We examine how the formation of alternative stable states alters the community's response to changing environmental forcing, and we identify conditions under which the ecosystem exhibits hysteresis with potential for catastrophic regime shifts. CONCLUSIONS: This work highlights the potential of connectionist theory to expand our understanding of evo-eco dynamics and collective ecological behaviours. Within this framework we find that, despite not being a Darwinian unit, ecological communities can behave like connectionist learning systems, creating internal conditions that habituate to past environmental conditions and actively recalling those conditions. REVIEWERS: This article was reviewed by Prof. Ricard V Solé, Universitat Pompeu Fabra, Barcelona and Prof. Rob Knight, University of Colorado, Boulder.

The Strengths and Difficulties Questionnaire (SDQ-Fin) among Finnish children and adolescents

Objective: The psychometric properties of The Strengths and Difficulties Questionnaire (SDQ-Fin), a Finnish version of a brief screening instrument were studied. Emotional and behavioural problems of 7- to 15-year-olds measured by the SDQ were reported, as well as the occurrence of self-reported eating disturbance symptoms and alcohol use among adolescents. Methods and samples: The cross-sectional school survey included 25 items of the SDQ-Fin, items about eating disturbance, alchol use and child psychiatric help-seeking. The study consists of three community samples: 1. The SDQ-Fin parent (n = 703) and teacher (n = 376) versions of 7 – 12 –year-olds, and self-report versions (n = 528) of 11 – 16 years-olds were obtained, and 2. the parent (n = 81) and self-report versions of 15-16 –year olds (n = 129) were obtained in Laitila and Pyhäranta. 3. The self-report versions of 13 – 16 – year-olds (n = 1458) in Salo and Rovaniemi were obtained. Results: The psychometric properties of the SDQ-Fin were for the most part comparable with the other European SDQ research results. The internal consistency (Cronbach’s alpha = 0.71 in all informants’ reports) and inter-rater reliability (between the pairs of reports r = 0.38 - 0.44) were adequate. The concurrent validity (r = 0.75 between the SDQ and the CBCL total scores; r = 0.71 between the SDQ and the YSR total scores) was sufficient. Factor analysis of the SDQ self-report generally confirmed the postulated structure for girls and boys, except for the conduct problems scale of boys, which was fused with emotional symptoms and with hyperactivity. The response rates, means and cut-off points of the SDQ self-report scores were similar to those found, e.g. in Norway and in Britain. A high level of psychological problems, especially emotional and conduct problems and hyperactivity-inattention, were associated with high level of eating disturbance symptoms and alcohol use. Conclusion: The results showed that the psychometric properties of the SDQ-Fin are adequate and provide additional confirmation of the usefulness of the SDQ-Fin for, e.g. screening, epidemiological research and clinical purposes.