Polar graphs of initial motions at an earthquake source

A modified technique for fault-plane solutions is developed, using polar diagrams with the earthquake focus at the origin and with station azimuth and angle of incidence at the focus as coördinates. A figure is given illustrating the distribution of initial longitudinal motion in a perfectly general case for a plane fault source with rectilinear slip, together with all the special cases which can be derived from it. Formulas are given which combine all the quantities entering into the solution

Factors important for persistence of Lactobacillus reuteri in the gastrointestinal tract

Lactobacillus reuteri ATCC 55730 is a commercially available probiotic i.e. health promoting bacterium. The interest for lactic acid bacteria (LAB) as probiotics might be due to the tradition of use in food preservation, their non-pathogenic behavior and, a natural occurrence in the human gastrointestinal (GI) tract. Although examples of clinically proven probiotic effects are increasing, the understandings of bacterial-host interactions behind these effects are only beginning to be unravelled. To put this thesis work into context, the field of probiotic research is described and health promoting mechanisms and perspectives of strain selection are discussed. The experimental work has focused on properties of L. reuteri ATCC 55730 that are tentatively important for persistence of this and other probiotic strains in the GI tract. To get an idea of the proteins on the surface of L. reuteri ATCC 55730, a draft genome sequence was scrutinized using bioinformatic tools. This resulted in the identification of a diverse set of 126 putative proteins with different possible means of surface attachment. The bacterium was also exposed to heat and acid stress and the response monitored by DNA microarrays. Acid stress is a well-documented way of investigating probiotic strains, since survival in the acidic GI tract is considered a prerequisite for a probiotic effect. Heat stress could be considered an artificially constructed environment for a probiotic bacterium, but is probably still relevant in elucidating mechanisms of persistence in other stressful conditions such as the passage of the GI tract. To further investigate genes revealed in the bioinformatical and DNA microarray analysis as well as a set of genes from the seven earlier identified two-component systems of L. reuteri ATCC 55730, 14 genes were mutated. These where then evaluated for ecological performance using a three-stage continuous culture system simulating a human colon using a real time PCR approach to monitor the relative abundance of the individual mutants. Two caseinolytic protease (Clp) genes, clpE and clpL that were induced in heat and acid stress respectively, both showed importance for persistence in the colon model

Initial motion of the first longitudinal earthquake wave recorded at Pasadena and Huancayo

The initial motion of the first longitudinal earthquake waves (P waves) recorded at a station is (1) upward or away from the epicenter (compression = c) or (2) downward or toward the epicenter (dilatation = d). The P waves do not change their phase during their propagation through the earth, and the first motion, obtained from seismograms, depends only on the earthquake mechanism. The directions of later waves (such as pP, P_cP, PP, etc.) depend both on the earthquake mechanism and the possible phase changes on reflections; also, their directions are generally more difficult to determine from seismic records, owing to the motion already existing when they arrive. When the earthquake mechanism has been established by means of the P waves, the direction of motion of the later waves could give some information about the earth's interior

Teleseismic magnitude relations

Using available sets of magnitude determinations, primarily from Uppsala seismological bulletin, various extensions are made of the Zurich magnitude recommendations of 1967. Thus, body-wave magnitude (m) and surface-wave magnitudes (M) are related to each other for 12 different earthquake regions as well as world-wide. Depth corrections for M are derived for all focal depths. Formulas are developed which permit calculation of M also from vertical component long-period seismographs. Body-wave magnitudes from broad-band and narrow-band short-period seismographs are compared and relations deduced. Applications are made both to underground nuclear explosions and to earthquakes. The possibilities of explosion-earthquake discrimination on the basis of magnitudes are examined, as well as the determination of explosive yield from magnitudes. For earthquakes, relations between magnitudes of main earthquakes and largest aftershocks are investigated. A world-wide station network for more homogeneous magnitude determinations is suggested in order to provide the necessary reference system

Hur påverkar ympning växtnäringsupptagning och avkastning i ekologisk växthusgurka?

Odlingssäsongen 2009 undersöktes hur ympning påverkar gurkskördens storlek, tidighet och kvalitet. Dessutom studerades hur olika metoder för plockning och beskärning påverkade skörden. Projektet genomfördes i samarbete mellan praktiker, trädgårdsrådgivare och forskare

Availability of phosphorus in greenhouse cropping systems with tomatoes - influence of soil and citric acid

Analyses of plant sap from organic greenhouse tomato crops show that the levels of phosphorus (P) are frequently low, despite the fact that soil analyses indicate P status in the soil to be good. In the present study, two soils (A and B) with a pH of just over 6 and a high total content of N and P were investigated with respect to release of P and uptake in a tomato crop. The fertilisers primarily used on soil A was silage and blood meal, and on soil B Vinasse and blood meal. An incubation experiment showed that the release of P per unit time was greater from soil A than soil B. This difference between the two soils may be due to lower soil organic matter concentration, with less P sorbed by Al and Fe on soil A, and a fertiliser regime which favours a high concentration of dissolved organic carbon in this soil. Tomato plants grown for 10 weeks in the soils had greater DW production, total uptake of P and concentration of P in the leaves on soil A than on soil B. Addition of citric acid to the soils in order to mobilise P increased plant yield and uptake of N and P on soil A. Despite the increased growth, the concentration of P in plant leaves increased and the N concentration was unchanged. On soil B addition of citric acid decreased Zn uptake in the tomato plants despite good availability, resulting in a lower concentration of this micronutrient in the leaves. The plants on soil A maintained their concentrations of all micronutrients analysed, but the ratio of P to micronutrients increased. Thus for commercial organic tomato growers, adding citric acid with the irrigation water offers a possibility to increase P availability

The aftershock sequence of the Kamchatka earthquake of November 4, 1952

Aftershock epicenters of the Kamchatka earthquake of November 4, 1952, are distributed over an area approximately 1,030 kilometers in length by 240 kilometers in width. Assuming that this distribution represents the active strain zone, the total average strain, average elastic energy, and average stress of the rocks before slip were 11.9 × 10^(−5), 1.35 × 10^2 ergs/cm.^3, and 12.6 kg/cm.^2, respectively. The strain-release curve of the sequence has been constructed using observations from Uppsala and Kiruna. The data include more than 400 shocks with magnitudes 6.0 and greater which have occurred up to December, 1956. The curve exhibits three segments each of the form ΣJ^(1/2) = A + B log t, where J is the energy and t is the time measured from the time of the principal earthquake. The slope B changes abruptly at t = 0.4 days and at t = 195 days, the latter change being particularly pronounced. Moreover, this was accompanied by other evidence suggesting a change in mechanism. The coefficients B have almost the exact ratio of 1 : 2 : 5 in the three intervals 0-0.4, 0.4—195, and after 195 days. The aftershock activity has its highest concentration in the vicinity of the principal earthquake and tapers off toward both ends of the active fault segment. The majority of the aftershocks have clear pP impulses occurring generally 9 to 13 sec. after P, indicating that the foci were in or close to the Mohorovičić discontinuity. The rate of strain accumulation and release for the time interval from 1897 to 1956 for the entire Kamchatka-northern Japan stress system shows a slow decrease with time. Comparison of the rate of the entire system with that of the aftershock sequence leads to an approximate estimate of the possible duration of the sequence

Mechanisms of the aftershocks of the Kern County, California, earthquake of 1952

Using directions of first motion of longitudinal waves recorded at near-by stations, the orientation of fault traces and the nature of fault motions have been deduced for fifty-seven earthquakes of the Kern County aftershock series. Unlike the main shock, the aftershocks exhibit considerable strike slip with left-hand strike slip dominating on and to the south of the White Wolf fault and right-hand strike slip and dip slip to the north of it. The two last-mentioned mechanisms represent a secondary strain release, beginning not earlier than thirty-seven hours after the main shock

Finns det en prispremie på ekologiska bomullskläder?

Idag är ekologiska produkter ett mycket omdebatterat ämne. En tydlig betalningvilja kan urskiljas på ekologiska matvaror men hur ser denna ut för ekologiska kläder? Värderas dessa också högre av konsumenterna? Syftet med uppsatsen är att undersöka om det finns en prispremie på ekologiskt producerade bomullskläder samt utreda eventuella bakomliggande orsaker till resultatet. Undersökningen kommer endast behandla bastoppar för kvinnor i form av linnen och t-shirtar. En begränsning till toppar från lågpriskedjor som HM, Lindex, KappAhl, Gina Tricot och Åhléns görs även. För efterforskningen insamlas data från lågpriskedjorna där pris samt andra egenskaper dokumenteras. Datat används sedan för att skatta en hedonisk prismodell för att påvisa vilken verkan de olika egenskaperna har på priset. Den relevanta egenskapen, huruvida plagget är producerad av ekologiskt alternativt konventionellt odlad bomull, visar på en negativ korrelation mellan priset och om produkten är ekologisk. Resultatet antyder att ekologiska bomullsplagg i snitt är 29 kr billigare och visar på ett signifikant estimat. En prispremie för ekologiska bomullskläder kan därför inte konstateras. Detta resultat skiljer sig från tidigare studier som visat på tydlig betalnigsvilja för ekologiska matvaror där samma metod tillämpats. För kläder har studier baserat på enkätundersökningar också visat på en betalnignsvilja hos konsumenterna. För framtida studier vore det intressant att inkludera andra butiker och kedjor för att få en bredare uppfattning samt att utöka observationen av plagg. En annan intressant vinkel skulle vara att jämföra Sverige med andra länder för att se hur priser skiljer sig samt företagens utbud och märkning.Today, organic products are a highly debated. A clear willingness to pay can be distinguished for organic food products but how about for organic clothing? Do consumers also value these organic products higher? The purpose of this paper is to examine if there is a price premium for organically produced cotton clothing as well as investigate possible underlying causes for the result. The study will deal only with basic tops for women in the form of tank tops and t -shirts. A limitation to tops from low price chains like HM, Lindex, KappAhl, Gina Tricot and Åhlens is also done. For the research, data has been collected from the chains where price and other characteristics have been documented. The data is then used to estimate a hedonic pricing model for demonstration of the impact on price with respect to the various attributes. The relevant characteristic, whether the product is produced from organically alternatively conventionally grown cotton, indicate a negative correlation between the price and if the product is organic. The results suggest that organic cotton tops are on average 29 SEK cheaper and show a significant estimate. A price premium for organic cotton clothing is therefore not observed. This result differs from previous studies that have shown a clear willingness to pay for organic food where the same method, hedonic pricing, has been applied. For clothing, studies based on surveys also indicated that consumers where willing to pay a higher price for the organically produced. For future studies, it would be interesting to include other stores and chains to get a broader view and to expand the observation of garments. Another interesting angle would be to compare Sweden with other countries to see how prices differ in realtion to companys supply and way of labeling

Quality-Based Clustering of Food Products for Customized Food Logistics

Perishability and quality deterioration over time makes food differ from industrial products. The objective of this research is to describe the food quality from a logistics perspective and specify which characteristics of food products are necessary to consider in designing food logistics. These characteristics include food sensory factors, food safety factors, packaging, and the interaction of all these factors with the surrounding environment which can occur related to the logistics processes.According to the results, food products are suggested to be divided into 6 major groups based on their similarity in the interaction with surrounding environment factors affecting the products during logistics activities. These groups are Vegetables, Fruits, Biennial vegetables, Chilled & Super-Chilled, Frozen, and Ambient. Subsequently, the sensitivity of each group was analyzed with regard to the environmental factors they are exposed to during logistics, such as e.g. temperature variations, humidity, or pressure and vibration.The results of this study can increase the knowledge and know-how for more efficient and safer food transports while minimizing the risk of damage to the food products during transport