A City Hall for Boston, Massachusetts

Thesis (M.Arch)--Massachusetts Institute of Technology, Dept. of Architecture, 1961.Accompanying drawings held by MIT Museum.Includes bibliographical references (leaves 58-59).by Thomas Allan Briner.M.Arc

A New System for Automatic Radiotracking of Small Mammals

We developed a radiotracking system for automatic and continuous data collection, which allows the radiotracking of several animals at the same time. Based on a system controller, 3 fixed antennas, and small-size radiotransmitters (<2 g, 14 by 12 by 4 mm), the system has the capacity to record several individuals continuously at intervals of <5 min. Antennas, positioned at fixed points in the field, forward the signals from tagged animals to the system controller, where data are collected. The coordinates of the individual's locations are calculated through triangulation on the basis of the angles of incidence from the transmitter signal to each antenna. Transmitters are individually identified by the chronological sequence of their signals. Field tests with Microtus arvalis show the utility of the new technique and possibilities for the syste

Local non-equilibrium distribution of charge carriers in a phase-coherent conductor

We use the scattering matrix approach to derive generalized Bardeen-like formulae for the conductances between the contacts of a phase-coherent multiprobe conductor and a tunneling tip which probes its surface. These conductances are proportional to local partial densities of states, called injectivities and emissivities. The current and the current fluctuations measured at the tip are related to an effective local non-equilibrium distribution function. This distribution function contains the quantum-mechanical phase-coherence of the charge carriers in the conductor and is given as products of injectivities and the Fermi distribution functions in the electron reservoirs. The results are illustrated for measurements on ballistic conductors with barriers and for diffusive conductors.Comment: 4 pages, 2 figures, submitted to "Comptes Rendus de l'Academie des Sciences

High prevalence rates of Toxoplasma gondii in cat-hunted small mammals - Evidence for parasite induced behavioural manipulation in the natural environment?

Toxoplasma gondii causes one of the most frequent parasitic infections in vertebrates on earth. The present study aimed to assess the occurrence of T. gondii infection in cat-hunted wild small mammals, and to determine the circulating T. gondii genotypes in cat prey. There is evidence suggesting that T. gondii may manipulate rodents' behaviour enhancing transmission to their definitive feline host by facilitating predation. Given that most studies focusing on rodent behavior have been performed under laboratory conditions, we tested this hypothesis in the natural environment. We analysed 157 cat-hunted wild small mammals of six different species from Switzerland. Brain and skeletal muscle samples from each animal were tested for T. gondii DNA by PCR, and positive samples were genotyped using a multilocus sequence typing approach, including 10 genetic markers. Additionally, to evaluate exposure to cat faeces, the presence of Taenia taeniaeformis metacestodes was investigated at necropsy. The prevalence of T. gondii in cat-hunted Arvicola amphibius s.l. was 11.1% (7/63), 14.6% (7/48) in Apodemus spp., 13.6% (3/22) in Myodes glareolus, 6.7% (1/15) in Crocidura russula, and 0% in Microtus arvalis (0/8) and Sorex sp. (0/1). All completely genotyped T. gondii parasites, exhibited the ToxoDB #3 genotype, a Type II variant. We additionally analysed 48 trap-captured A. amphibius s.l., which all tested negative for T. gondii infection, contrasting with the higher prevalence in cat-hunted A. amphibius s.l. (0% vs. 11.1%; p = 0.0176). Furthermore, T. taeniaeformis was detected in both groups, indicating widespread contamination with cat faeces in the sampled areas. These results provide evidence that T. gondii infected rodents are at higher risk to be predated by cats and therewith support the behaviour manipulation hypothesis

High prevalence rates of Toxoplasma gondii in cat-hunted small mammals - Evidence for parasite induced behavioural manipulation in the natural environment?

Toxoplasma gondii causes one of the most frequent parasitic infections in vertebrates on earth. The present study aimed to assess the occurrence of T. gondii infection in cat-hunted wild small mammals, and to determine the circulating T. gondii genotypes in cat prey. There is evidence suggesting that T. gondii may manipulate rodents’ behaviour enhancing transmission to their definitive feline host by facilitating predation. Given that most studies focusing on rodent behavior have been performed under laboratory conditions, we tested this hypothesis in the natural environment. We analysed 157 cat-hunted wild small mammals of six different species from Switzerland. Brain and skeletal muscle samples from each animal were tested for T. gondii DNA by PCR, and positive samples were genotyped using a multilocus sequence typing approach, including 10 genetic markers. Additionally, to evaluate exposure to cat faeces, the presence of Taenia taeniaeformis metacestodes was investigated at necropsy. The prevalence of T. gondii in cat-hunted Arvicola amphibius s.l. was 11.1% (7/63), 14.6% (7/48) in Apodemus spp., 13.6% (3/22) in Myodes glareolus, 6.7% (1/15) in Crocidura russula, and 0% in Microtus arvalis (0/8) and Sorex sp. (0/1). All completely genotyped T. gondii parasites, exhibited the ToxoDB #3 genotype, a Type II variant. We additionally analysed 48 trap-captured A. amphibius s.l., which all tested negative for T. gondii infection, contrasting with the higher prevalence in cat-hunted A. amphibius s.l. (0% vs. 11.1%; p = 0.0176). Furthermore, T. taeniaeformis was detected in both groups, indicating widespread contamination with cat faeces in the sampled areas. These results provide evidence that T. gondii infected rodents are at higher risk to be predated by cats and therewith support the behaviour manipulation hypothesis

Kleinsäuger mit Haarproben zuverlässig bestimmen

Um das Vorkommen der Schweizer Kleinsäugetiere zu untersuchen, müssen diese lebend gefangen und bestimmt werden. Gewisse ähnliche Arten lassen sich jedoch morphologisch nicht genau unterscheiden. Für eine sichere Artbestimmung ist deshalb bei einigen Arten eine DNA-Analyse unumgänglich. Die Entnahme von Haarproben ermöglicht eine für das Tier schnelle und schonende Gewinnung von DNA

Local densities, distribution functions, and wave function correlations for spatially resolved shot noise at nanocontacts

We consider a current-carrying, phase-coherent multi-probe conductor to which a small tunneling contact is attached. We treat the conductor and the tunneling contact as a phase-coherent entity and use a Green's function formulation of the scattering approach. We show that the average current and the current fluctuations at the tunneling contact are determined by an effective local non-equilibrium distribution function. This function characterizes the distribution of charge-carriers (or quasi-particles) inside the conductor. It is an exact quantum-mechanical expression and contains the phase-coherence of the particles via local partial densities of states, called injectivities. The distribution function is analyzed for different systems in the zero-temperature limit as well as at finite temperature. Furthermore, we investigate in detail the correlations of the currents measured at two different contacts of a four-probe sample, where two of the probes are only weakly coupled contacts. In particular, we show that the correlations of the currents are at zero-temperature given by spatially non-diagonal injectivities and emissivities. These non-diagonal densities are sensitive to correlations of wave functions and the phase of the wave functions. We consider ballistic conductors and metallic diffusive conductors. We also analyze the Aharonov-Bohm oscillations in the shot noise correlations of a conductor which in the absence of the nano-contacts exhibits no flux-sensitivity in the conductance.Comment: 17 pages, 8 figure

Nanoscopic Tunneling Contacts on Mesoscopic Multiprobe Conductors

We derive Bardeen-like expressions for the transmission probabilities between two multi-probe mesoscopic conductors coupled by a weak tunneling contact. We emphasize especially the dual role of a weak coupling contact as a current source and sink and analyze the magnetic field symmetry. In the limit of a point-like tunneling contact the transmission probability becomes a product of local, partial density of states of the two mesoscopic conductors. We present expressions for the partial density of states in terms of functional derivatives of the scattering matrix with respect to the local potential and in terms of wave functions. We discuss voltage measurements and resistance measurements in the transport state of conductors. We illustrate the theory for the simple case of a scatterer in an otherwise perfect wire. In particular, we investigate the development of the Hall-resistance as measured with weak coupling probes.Comment: 10 pages, 5 figures, revte

Using narrative evidence synthesis in HRM research: an overview of the method, its application and the lessons learned

The use of systematic approaches to evidence review and synthesis has recently become more common in the field of organizational research, yet their value remains unclear and largely untested. First used in medical research, evidence review is a technique for identifying, evaluating and synthesizing existing empirical evidence. With greater demand for the best evidence about ‘what works’ in organizational settings, nuanced approaches to evidence synthesis have evolved to address more complex research questions. Narrative synthesis is perceived to be particularly suited to evaluating diverse evidence types spanning multiple disciplinary fields, characteristic of the HRM domain. This article evaluates the narrative evidence synthesis approach, explains how it differs from other techniques and describes a worked example in relation to employee engagement. We consider its strengths, the challenges of using it and its value in HRM research

Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.

We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies