Contribution of subcortical structures to cognition assessed with invasive electrophysiology in humans

Implantation of deep brain stimulation (DBS) electrodes via stereotactic neurosurgery has become a standard procedure for the treatment of Parkinson's disease. More recently, the range of neuropsychiatric conditions and the possible target structures suitable for DBS have greatly increased. The former include obsessive compulsive disease, depression, obesity, tremor, dystonia, Tourette's syndrome and cluster-headache. In this article we argue that several of the target structures for DBS (nucleus accumbens, posterior inferior hypothalamus, nucleus subthalamicus, nuclei in the thalamus, globus pallidus internus, nucleus pedunculopontinus) are located at strategic positions within brain circuits related to motivational behaviors, learning, and motor regulation. Recording from DBS electrodes either during the operation or post-operatively from externalized leads while the patient is performing cognitive tasks tapping the functions of the respective circuits provides a new window on the brain mechanisms underlying these functions. This is exemplified by a study of a patient suffering from obsessive-compulsive disease from whom we recorded in a flanker task designed to assess action monitoring processes while he received a DBS electrode in the right nucleus accumbens. Clear error-related modulations were obtained from the target structure, demonstrating a role of the nucleus accumbens in action monitoring. Based on recent conceptualizations of several different functional loops and on neuroimaging results we suggest further lines of research using this new window on brain functions.

Response of fine root respiration to variations in biotic and abiotic factors in a mixed Mediterranean forest affected by drought-induced secondary succession

Understanding the factors controlling fine root respiration (FRR) at different temporal scales will help to improve our knowledge about the spatial and temporal variability of soil respiration (SR) and to improve future predictions of CO2 effluxes to the atmosphere. Here we present a comparative study of how FRR respond to variability in soil temperature and moisture in two widely spread species, Scots pines (Pinus sylvestris L.) and Holm-oaks (HO; Quercus ilex L.). Those two species show contrasting water use strategies during the extreme summer-drought conditions that characterize the Mediterranean climate. The study was carried out on a mixed Mediterranean forest where Scots pines affected by drought induced die-back are slowly being replaced by the more drought resistant HO. FRR was measured in spring and early fall 2013 in excised roots freshly removed from the soil and collected under HO and under Scots pines at three different health stages: dead (D), defoliated (DP) and non-defoliated (NDP). Variations in soil temperature, soil water content and daily mean assimilation per tree were also recorded to evaluate FRR sensibility to abiotic and biotic environmental variations. Our results show that values of FRR were substantially lower under HO (1.26 ± 0.16 microgram CO2 /groot·min) than under living pines (1.89 ± 0.19 microgram CO2 /groot·min) which disagrees with the similar rates of soil respiration previously observed under both canopies and suggest that FRR contribution to total SR varies under different tree species. The similarity of FRR rates under HO and DP furthermore confirms other previous studies suggesting a recent Holm-oak root colonization of the gaps under dead trees. A linear mixed effect model approach indicated that seasonal variations in FRR were best explained by soil temperature (p<0.05) while soil moisture was not exerting any direct control over FRR, despite the low soil moisture values during the summer sampling. Plant assimilation rates were positively related to FRR explaining part of the observed variability (p<0.01). However the positive relations of FRR with plant assimilation occurred mainly during spring, when both soil moisture and plant assimilation rates were higher. Our results finally suggest that plants might be able to maintain relatively high rates of FRR during the sub-optimal abiotic and biotic summer conditions probably thanks to their capacity to re-mobilize carbon reserves and their capacity to passively move water from moister layers to upper layers with lower water potentials (where the FR were collected) by hydraulic lift.

De fine miraculorum in Novo Testamento enarratorum

Arkit: 1 arkintunnukseton lehti, A-B4 C1.

De fine studiorum genuino

Invocatio: B.c.D.

Fine et via educationis

Arkit: 1 arkintunnukseton lehti, A-B4.

Time-Resolved Photoluminescence in Antimonide and Dilute Nitride Quantum Well Structures

This Master's thesis is devoted to semiconductor samples study using time-resolved photoluminescence. This method allows investigating recombination in semiconductor samples in order to develop quality of optoelectronic device. An additional goal was the method accommodation for low-energy-gap materials. The first chapter gives a brief intercourse into the basis of semiconductor physics. The key features of the investigated structures are noted. The usage area of the results covers saturable semiconductor absorber mirrors, disk lasers and vertical-external-cavity surface-emittinglasers. The experiment set-up is described in the second chapter. It is based on up-conversion procedure using a nonlinear crystal and involving the photoluminescent emission and the gate pulses. The limitation of the method was estimated. The first series of studied samples were grown at various temperatures and they suffered rapid thermal annealing. Further, a latticematched and metamorphically grown samples were compared. Time-resolved photoluminescence method was adapted for wavelengths up to 1.5 µm. The results allowed to specify the optimal substrate temperature for MBE process. It was found that the lattice-matched sample and the metamorphically grown sample had similar characteristics.

Crystal structures of 5-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II) and Zn(II)

The crystal and molecular structures of [bis(5-chloro-2-methoxybenzoate)tetraaquamanganese(II)], [pentaaqua(5-chloro-2-methoxybenzoato)cobalt(II)] (5-chloro-2-methoxybenzoate), [pentaaqua(5-chloro-2-methoxybenzoato)nickel(II)] (5-chloro-2-methoxybenzoate) and [aquabis(5-chloro-2-methoxybenzoate)zinc(II)] monohydrate were determined by a single-crystal X-ray analysis. Mn(H2O)4L2 (where L = C8H6ClO3) crystallizes in the monoclinic system, space group P21/c. [Co(H2O)5L]L and [Ni(H2O)5L]L both are isostructural, space group P212121. The crystals of [Zn(H2O)L2] H2O are monoclinic, space group Pc. Mn(II) ion is positioned at the crystallographic symmetry center. Mn(II) and Co(II) ions adopt the distorted octahedral coordination but Zn(II) tetrahedral one.The carboxylate groups in the complexes with M(II) cations function as monodentate, bidentate and/or free COO-groups. The ligands exist in the crystals as aquaanions. The complexes of 5-chloro-2-methoxybenzoates with Mn(II), Co(II) and Zn(II) form bilayer structure.

Network Structures and Modularity among Biofuel Heating System Manufacturers

The aim of this thesis was to study network structures and modularity among biofuel heating system manufacturers in the Finnish bioenergy sector by utilizing the perspectives of numerous Finnish bioenergy specialists. The study is qualitative due to the fact that the research material was gathered with semi-structured theme interviews during May and June 2010. The research methodology used in the thesis combines conceptual and action-oriented approach. Networks, value nets, and modularity were studied from different perspectives. Three network and platform strategies were discovered and a general network structure was formed. Moreover, benefits and disadvantages of networks and modularity among biofuel heating system manufacturers were illustrated. The analysis provides a comprehensive perception of the industry. The results of the research were constructed by implementing existing theories into practice. Also future recommendations for the biofuel heating system manufacturers were given. The results can be considered to be beneficial because the number of previous studies about the subject is relatively small. The reliability of the study is eminent because the number of the interviews was inclusive.

The structures of the honeydew oligosaccharides synthesized by Claviceps africana

The structures of the principal oligosaccharides in the honeydew exudate of the sorghum ergot pathogen Claviceps africana, which has become epidemic in the Americas, have been characterized through linkage analysis using FAB-MS and GC-MS techniques, as 1,6-di-b-D-fructofuranosyl-D-mannitol and 1,5-di-b-D-fructofuranosyl-D-arabitol trisaccharides, 1-b-D-fructofuranosyl-D-mannitol and 5-b-D-fructofuranosyl-D-arabitol disaccharides and other minor disaccharides and trisaccharides. Their structural diversity is explained according to perceived biosynthetic interrelationships in pathways that appear to be unique amongst ergot fungi, particularly concerning intra-molecular reduction of fructose. The oligosaccharide, 1,6-di-b-D-fructofuranosyl-D-mannitol, which inhibits C. africana macrospore germination at a concentration in water of 1 g/mL or more, forms together with other slightly less bioactive oligosaccharides, the basis of a novel strategy to limit ergot disease losses in hybrid sorghum seed production.

Development of simple and efficient synthetic strategies for production of fine chemicals of pharmaceutical relevance : metal-mediated allylation combined with applied catalysis

Den snart 200 år gamla vetenskapsgrenen organisk synteskemi har starkt bidragit till moderna samhällens välfärd. Ett av flaggskeppen för den organiska synteskemin är utvecklingen och produktionen av nya läkemedel och speciellt de aktiva substanserna däri. Därmed är det viktigt att utveckla nya syntesmetoder, som kan tillämpas vid framställningen av farmaceutiskt relevanta målstrukturer. I detta sammanhang är den ultimata målsättningen dock inte endast en lyckad syntes av målmolekylen, utan det är allt viktigare att utveckla syntesrutter som uppfyller kriterierna för den hållbara utvecklingen. Ett av de centralaste verktygen som en organisk kemist har till förfogande i detta sammanhang är katalys, eller mera specifikt möjligheten att tillämpa olika katalytiska reaktioner vid framställning av komplexa målstrukturer. De motsvarande industriella processerna karakteriseras av hög effektivitet och minimerad avfallsproduktion, vilket naturligtvis gynnar den kemiska industrin samtidigt som de negativa miljöeffekterna minskas avsevärt. I denna doktorsavhandling har nya syntesrutter för produktion av finkemikalier med farmaceutisk relevans utvecklats genom att kombinera förhållandevis enkla transformationer till nya reaktionssekvenser. Alla reaktionssekvenser som diskuteras i denna avhandling påbörjades med en metallförmedlad allylering av utvalda aldehyder eller aldiminer. De erhållna produkterna innehållende en kol-koldubbelbindning med en närliggande hydroxyl- eller aminogrupp modifierades sedan vidare genom att tillämpa välkända katalytiska reaktioner. Alla syntetiserade molekyler som presenteras i denna avhandling karakteriseras som finkemikalier med hög potential vid farmaceutiska tillämpningar. Utöver detta tillämpades en mängd olika katalytiska reaktioner framgångsrikt vid syntes av dessa molekyler, vilket i sin tur förstärker betydelsen för de katalytiska verktygen i organiska kemins verktygslåda.

Advanced welding technologies used for arctic metal structures

Rapid depletion of easy-to-access fossil fuel, predominantly, oil and gas resources has now necessitated increase in need to develop new oil and gas sources in ever more remote and hostile environments. This is necessary in order to explore more oil and gas resources to meet rapidly rising long-term energy demand in the world, both at present and in the nearest future. Arctic is one of these harsh environments, where enormous oil and gas resources are available, containing about 20% of the world total oil and gas, but the environmental conditions are very harsh and hostile. However, virtually all the facilities required for the exploration and development of this new energy source are constructed with metals as well as their alloys and are predominantly joined together by welding processes and technologies. Meanwhile, due to entirely different environment from the usual moderate temperate region, conventional welding technologies, common metals and their alloys cannot be applied as this Arctic environment demand metals structures with very high toughness and strength properties under extremely low temperature. This is due to the fact that metals transit from ductility to brittleness as the temperature moves toward extreme negative values. Hence, this research work investigates and presents the advanced welding technologies applicable to Arctic metal structures which can give satisfactory weldments under active Arctic service conditions. .

”Iha fine. Paljon parempaa kuin edellisessä koulussa!” Kyselytutkimus loimaalaisten kahdeksas- ja yhdeksäsluokkalaisten kouluruokailusta ja kouluruokailutottumuksista

Tutkimuksella tarkasteltiin yläkoululaisten kouluruokailun ajankohtaisia ilmiöitä sekä selvitettiin kouluruokailutottumusten ja oppilaiden taustamuuttujien (sukupuoli, painoindeksi, fyysinen kunto ja aktiivisuus, uni ja väsyneisyys sekä koulumenestys) mahdollista yhteyttä. Tutkimuksen kohderyhmä muodostui Loimaan kaupungissa sijaitsevista Puistokadun ja Opintien koulun kahdeksas- ja yhdeksäsluokkalaisista oppilaista. Tutkimus suoritettiin kyselyyn osallistuneilla kouluilla marraskuun alussa 2011, jolloin tutkimukseen osallistui molemmista kouluista 69 oppilasta kokonaisotannan ollessa 138 oppilasta. Tutkimusjoukko koostui 65 tytöstä ja 72 pojasta. Tämä tutkimus on tutkimusotteeltaan pääosin kvantitatiivinen, mutta siinä esiintyy myös kvalitatiivisia piirteitä. Tutkimusmenetelmänä käytettiin strukturoituja ja avoimia kysymyksiä sisältävää kyselylomaketta, joka oli muodostettu tätä tutkimusta varten aiempien tutkimuksien pohjalta. Tutkimuksen tulokset olivat myönteisiä kouluruokailun osalta. Oppilaiden antama keskiarvo kouluruoalle oli 7,5 arvosteluasteikon ollessa neljästä kymmeneen. Oppilaista 86 prosenttia osallistui kouluruokailuun päivittäin ja 83 prosenttia viihtyi kouluruokalassa yli kymmenen minuuttia. Oppilaat söivät ruoka-aineiden välisiä suhteita kuvaavan lautasmallin eri osia hyvin. Oppilaat toivoivat kouluruokailuunsa enemmän jälkiruokia ja pehmeää leipää sekä paremmanmakuista pääruokaa. Oppilaiden taustamuuttujia tarkastellessa havaittiin niillä olevan yhteyksiä oppilaiden kouluruokailutottumuksiin, mutta tilastollisesti tarkasteltuna yhteydet eivät olleet merkitseviä. Ainoastaan yöunien keston ja väsyneisyyden yhteys kouluruokailutottumuksiin oli melkein merkitsevää. Tutkimukseen osallistuneet oppilaat eivät noudattaneet vähähiilihydraattista ruokavaliota, joten ”karppauksella” ei ollut vaikutuksia kouluruokailuun. Tutkimuksen tuloksia verrattaessa laajempiin tutkimuksiin (Terveyden ja hyvinvoinnin laitos 2011; Hoppu ym. 2008; Urho & Hasunen 2004), voidaan todeta tutkimukseen osallistuneiden oppilaiden pitävän kouluruoasta ja kouluruokailusta enemmän kuin ikätoverinsa. Oppilaat osallistuivat aktiivisemmin kouluruokailuun, söivät lautasmallin osia paremmin ja viettivät enemmän aikaa kouluruokailussa.