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Lambda-polarization in e+e--annihilation at the Z0-pole

Strange quarks produced in e+e--annihilation at the Z0-pole are very strongly polarized. To study to which extent this polarization is transferred to the observable hadrons would give interesting information on the hadronization mechanism. Γ-particles produced with relatively large x-values are expected to frequently contain an originally produced s-quark. We estimate that Γ-particles with x>0.3 s

Biliary microflora in acute cholecystitis and the clinical implications

A prospective bacteriologic investigation was made in 43 consecutive patients (mean age 63 years) operated on for acute cholecystitis. Gallbladder bile and wall were cultured, using four methods and with special attention to optimal anaerobic technique. Cultures were positive in 72% of the patients, yielding a wide variety of species (21 species among 48 isolates). Anaerobes constituted 23% of the

Interactions between single latex particles and silica surfaces studied with AFM

The spreading of single styrene-acrylic latex particles on silicon oxide C surfaces was studied using atomic force microscopy (AFM). Three latexes with different glass transition temperature (Tg) were used and the effects of temperature, time and preparation method were investigated. Particle sizes and shape were measured with AFM and the contact angles were calculated. The observed rate for the s

Ergosterol content in ericaceous hair roots correlates with dark septate endophytes but not with ericold mycorrhizal colonization

The relationship between ergosterol content in ericaceous hair roots and ericoid mycorrhizal (ErM) colonization versus dark septate endophytic (DSE) hyphal colonization was examined in a dwarf shrub-dominated subarctic mire in Northern Sweden. Ergosterol content in hair roots did not correlate with ErM colonization in corresponding root samples. However, a significant positive relationship was fou

Natthärbärget som vandrande lösning

During most of the 20th century shelters for the homeless has been criticized as being of too low standard and an unworthy way of living in a welfare society. During the 1960s and 1970s most shelters in Sweden were shut down and replaced with other forms of housing for the homeless. Since the late 1980s and early 1990s the issue of homelessness has returned to the political agenda as an existing s

Molecular interference of Cd2+ with Photosystem II

Many heavy metals inhibit electron transfer reactions in Photosystem II (PSII). Cd2+ is known to exchange, with high affinity in a slow reaction, for the Ca2+ cofactor in the Ca/Mn cluster that constitutes the oxygen-evolving center. This results in inhibition of photosynthetic oxygen evolution. There are also indications that Cd2+ binds to other sites in PSII, potentially to proton channels in an

Search for leptoquark bosons in ep collisions at HERA

A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e(+) p and e(-) p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity of 117 pb(-1). No evidence for the direct or indirect production of such particles is found in data samples with a large transverse momentum final state el

Experimental studies of attosecond pulse trains

We present experimental measurements of attosecond pulse trains. The characterization of the pulses uses a spectral interferometry technique that is implemented with a Mach-Zehnder interferometer. This allows us to manipulate independently the pump and probe pulses for a wide range of applications. By letting the attosecond pulses pass through metallic films, we can in particular compensate for th

Probing Control : Analysis and Design with Application to Fed-Batch Bioreactors

Popular Abstract in Swedish I de flesta reglerproblem är syftet att hålla utsignalen nära ett önskat värde trots störningar som påverkar systemet. Ibland är det bästa referensvärdet inte känt i förväg. I stället skall det hittas i realtid för att optimera systemets prestanda. Denna avhandling behandlar en så kallade probing-strategi som kan tillämpas för denna klass av problem. Fokus ligger i tillIn most control problems the objective is to control the output at a desired value in spite of disturbances. In some cases, the best setpoint is not known a priori and it should be found online to optimize the process performance. This thesis examines a probing strategy that can be applied for this class of problems. The focus is on the application of the technique to the control of feed supply in

Analysis and modeling of solute transport dynamics by breakdown coefficients and random cascades

The small-scale variability and scaling properties of solute transport dynamics were investigated by laboratory experiments. Dye-stained water was applied at a constant flux in a Plexiglas Hele-Shaw cell filled with soil material, and the transport process was registered by digital photographs of the cell front, producing a very high resolution in both time (minutes) and space (millimeters). The e

The costoclavicular joint

Two patients with a costoclavicular joint were discovered by chance during a survey of cervical spines. These seem to be the first to be described in the radiological literature. No other case was found in a further review of 500 consecutive spine radiographs. The costoclavicular joint is a variant of the ligamentous connection between the medial part of the clavicle and the first rib.