Let K be a quadratic imaginary number field, let Kp^(infinity) the top of its p-class field tower for p an odd prime, and let G=Gal(Kp^(infinity)/K). It is known, due to a tremendous collection of work ranging from the principal results of class field theory to the famous Golod-Shafarevich inequality, that G is finite if the p-rank of the class group of K is 0 or 1, and is infinite if this rank is at least 3. This leaves the rank 2 case as the only remaining unsolved case. In this case, while finiteness is still a mystery, much is still known about G: It is a 2-generated, 2-related pro-p-group equipped with an involution that acts as the inverse modulo commutators, and is of one of three possible Zassenhaus types (defined in the paper). If such a group is finite, we will call it an interesting p-tower group. We further the knowledge on such groups by showing that one particular Zassenhaus type can occur as an interesting p-tower group only if the group has order at least p^24 (Proposition 8.1), and by proving a succinct cohomological condition (Proposition 4.7) for a p-tower group to be infinite. More generally, we prove a Golod-Shafarevich equality (Theorem 5.2), refining the famous Golod-Shafarevich inequality, and obtaining as a corollary a strict strengthening of previous Golod-Shafarevich inequalities (Corollary 5.5). Of interest is that this equality applies not only to finite p-groups but also to p-adic analytic pro-p-groups, a class of groups of particular relevance due to their prominent appearance in the Fontaine-Mazur conjecture. This refined version admits as a consequence that the sizes of the first few modular dimension subgroups of an interesting p-tower group G are completely determined by p and its Zassenhaus type, and we compute these sizes. As another application, we prove a new formula (Corollary 5.3) for the Fp-dimensions of the successive quotients of dimension subgroups of free pro-p-groups.

Simulation techniques are developed for high NA polarized microscopy with Babinet's principle, partial coherence and vector diffraction for non-periodic geometries. A mathematical model for the Babinet approach is developed and interpreted. Simulation results of the Babinet's principle approach are compared with those of Rigorous Coupled Wave Theory (RCWT) for periodic structures to investigate the accuracy of this approach and its limitations.A microscope system using a special solid immersion lens (SIL) is introduced to image Blu-Ray (BD) optical disc samples without removing the protective cover layer.Aberration caused by the cover layer is minimized with a truncated SIL. Sub-surface imaging simulation is achieved by RCWT, partial coherence, vector diffraction and Babinet's Principle. Simulated results are compared with experimental images and atomic force microscopy (AFM) measurement.A technique for obtaining native and induced using a significant amount of evanescent energy is described for a solid immersion lens (SIL) microscope.Characteristics of native and induced polarization images for different object structures and materials are studied in detail. Experiments are conducted with a NA = 1.48 at wavelength550nm microscope. Near-field images are simulated and analyzed with an RCWT approach. Contrast curve versus object spatial frequency calculations are compared with experimental measurements. Dependencies of contrast versus source polarization angles and air gap for native and induced polarization image profiles are evaluated. By using the relationship between induced polarization and topographical structure, an induced polarization image of an alternating phase shift mask (PSM) is converted into a topographical image, which shows very good agreement with AFM measurement. Images of other material structures include a dielectric grating, chrome-on-glass grating, silicon CPU structure, BD-R and BD-ROM.

Syfte och frågeställningar Syftet med studien har varit att jämföra lärares och rektorers syn på friluftsdagar avseende mål, innehåll och organisation. Resultatet har tolkats med utgångspunkt i en läroplansteoretisk modell. De mer preciserade frågeställningarna var: Vad vill skolan uppnå med friluftsdagarna? Hur ramar skolan in begreppet friluftsdag genom förekomsten av olika inslag? Hur ofta vill lärarna att olika inslag ska förekomma på friluftsdagarna samt vilka skolämnen är och bör finnas representerade? Hur ser organisationen ut kring friluftsdagarna på skolan enligt lärare och rektorer samt hur bör den se ut enligt lärarna? Vilken kompetens anser lärare och rektorer vara viktig för planeringen av friluftsdagarna?  Metod En enkätstudie med kvalitativa inslag genomfördes på 121 ämneslärare i svenska och idrott och hälsa samt 67 rektorer från högstadieskolor i Stockholms län. Enkäter skickades ut via e-post till respondenterna som valts ut genom ett obundet slumpmässigt urval från en förteckning på Skolverkets hemsida. Studien fick, efter tre påminnelser, en svarsfrekvens på 44,1 procent (n=83). Resultat och diskussion Resultatet visar att ”naturvistelse/friluftsliv” var det som lärare och rektorer tyckte var viktigast att uppnå på friluftsdagar och detta realiseras också genom inslag av natur- och utomhusvistelse. Lärare och rektorer ramar in begreppet friluftsdag olika. De har olika uppfattning om förekomsten av inslaget ”friluftsliv” och det gäller också inslaget ”fysisk aktivitet”. Rektorerna ansåg att dessa inslag förkommer i större utsträckning än lärarna. I jämförelsen mellan lärares uppfattning om vad som förekommer och hur det bör se ut på skolan visades en signifikant skillnad på inslagen ”tävlingsmoment”, ”ämnesintegrering”, ”naturvistelse”, ”fysisk aktivitet” samt ”miljö och hållbar utveckling”. Tävlingsmoment förekommer för ofta och kan tänkas ta plats från de andra inslagen som lärarna önskade mer av på friluftsdagarna. Ämnet som var och bör vara mest representerande på friluftsdagarna var ämnet idrott och hälsa. Idrottsläraren anses vara den som har kompetensen att planera och organisera friluftsdagar och är också den som oftast planerar och organiserar friluftsdagarna. Lärarna i studien tycker dock att planeringen borde fördelas på fler lärare. Slutsats Det tycks finnas en kontinuitet i övergången mellan intentionerna på transformeringsarenan och realiseringsarenan när det kommer till frisk luft, natur och friluftsliv på friluftsdagarna. Däremot delar lärare respektive rektorer, på de olika arenorna, inte uppfattningen om hur ofta friluftsliv och fysisk aktivitet förekommer på friluftsdagarna. / Aim and questions The aim of this study has been to compare teachers’ and headmasters’ view on field-days’ goal, content and organisation. The results were interpreted on the basis of a “curriculum theoretical model”. The questions are: What do schools strive to attain with field days? How do schools define the conception of field day by the existence of different features? How often do teachers want different features to occur at field days and what school subjects are, and should be represented according to teachers? How does the organization around the field days look like according to teachers and headmasters, and how should it look like according to teachers? Which qualifications are important when planning field days according to teachers and headmasters? Method The study was carried out on 121 teachers of Swedish and teachers of PE and 67 headmasters from secondary schools in Stockholm country. A questionnaire was sent by e-mail to the respondents who were chosen by an independent random selection with the help of a list at the web page of the National Agency for education. The percentage of answers, after three reminders, were 44.1% (n = 83). Results and discussion Results shows that ”being in nature/outdoor life” was what the schools considered to be most important to attain at field-days and this is also what becomes realized by features as being in nature and being outdoor. Teachers and headmasters do frame the term of field-days in different ways. They have different opinions about the existence of the feature ”outdoor life” and this also applies to the feature ”physical education”. Headmasters think that those features exist more often than the teachers. When comparing teachers opinion about how it looks like in school and how it should look like there was a significant difference within the features ”elements of competition”, ”integrating school subjects”, ”being in nature”, ”physical activity” and ”environment and sustainable development”. Elements of competition do exist often on field days and are supposed to take place from other features that the teachers wanted more of. The school subject which was and should be most represented at the field days was the subject physical education. The PE-teacher is the one who is regarded to have the competence and who does most of the planning and organizing around the field days Nevertheless teachers think that the planning should be spread more among teachers. Conclusion There seems to be continuity in the transition between the intentions at the transforming arena and implementation at the field when it comes to fresh air, nature and outdoor life at the field days. However, the teachers respectively headmasters, on the different arenas, does not always share the same opinion about how often outdoor life and physical activity do exist on the field days.

This thesis investigated the apparent effectiveness of environmental education essential elements in school field trip programming. First, the elements essential to environmental education field trips were identified from the literature. Second, these elements were incorporated into a questionnaire that was administered as a pre/post test to elementary school students visiting an extensive indoor environmental education facility located in Montreal. Finally, 24 environmental education programs at eight institutions in Montreal were observed to investigate the extent and methodology of implementation of the essential elements. With regard to the chief institution, it was concluded that (1) the educational programming appeared to significantly increase environmental knowledge, and (2) the environmental attitudes were most strongly correlated with student background. Program observation at the eight institutions demonstrated that a wide array of environmental topics was presented, but there was insufficient instruction of environmental issues and action strategies. The list of observed implementation methodologies and the study conclusions could prove useful as a research-based foundation for effective environmental education field trip program development.

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The detection of specific temporal patterns in communication signals may be of vital importance for certain organisms. In crickets, for instance, a female will move towards a singing male only if she can recognize the appropriate pulse rate characteristic to its own species' song. Additionally, in order to evade predatory insectivorous bats, flying crickets must be able to track the predator's ultrasonic echolocation signals, which are emitted at a variety of pulse rates. In this thesis, the temporal processing, or the integration of stimulus through time, in the peripheral1 auditory system of the cricket will be investigated. / The ON1 interneuron temporal processing was first examined and compared at high (bat-like) and low carrier (cricket-like) frequencies in three different experimental paradigms. First, integration time, which corresponds to the time it takes for a neuron to reach threshold when stimulated at the minimum effective intensity, was found to be significantly shorter at high carrier frequency than at low carrier frequency. Second, phase locking to sinusoidally amplitude modulated (SAM) signals was more efficient at high frequency, especially at high modulation rates and low modulation depths. Finally, we examined the efficiency with which ON1 detects gaps in a constant tone. As reflected by the decrease in firing rate in the vicinity of the gap, ON1 is better at detecting gaps at low carrier frequency. Following a gap, firing rate increases beyond the pre-gap level. This "rebound" phenomenon is similar for low and high carrier frequencies. / To determine the source of this differential temporal processing, the sensory afferents making synapses with ON1 were investigated. Low frequency (MT-type) and ultrasound auditory receptors were compared on the basis of latency, maximum firing rate, adaptation, information transmission, bursting and feature detection. Ultrasound receptors (HFs) were found to have a shorter latency, a higher maximum firing rate and stronger adaptation than low-frequency receptors (LFs). Individual HFs transmitted more linear (lower-bound) information than LFs. However, HFs' responses were more correlated than LFs' (i.e. they had larger mutual information), so that when superposing the spike trains of LFs, information transmission in the lowest amplitude modulation rates was greatly improved, and, in some cases, reached the level of HFs. Feature detection by spike in HFs was better than in LFs. Feature detection by bursts was better than for spikes, but equivalent in both types of receptors. The level of bursting in HFs, however, was much higher than in LFs, making them better feature detectors in general. / 1Because it lies in the prothoracic ganglion, ON1 is technically part of the central nervous system. For the purpose of this thesis, however, because ON1 receives direct input from the receptors, it will be considered to be part of the peripheral auditory systems.

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