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This article studies the importance of demand and supply factors in the Swedish fertility transition using county-level data and panel regressions. Fertility started to decline around 1880 when marital fertility began a continuous decline. A gradual diffusion of parity-specific control was important in this process. The fertility of the oldest age groups declined fastest, even though the decline s
A method for studying PCB desorption behaviour from sediments using supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) is presented. Four sediments were investigated and extracted with supercritical carbon dioxide employing increasingly harsher extraction conditions ranging from 40 degrees C and 12MPa to 100 degrees C and 36.5 MPa. To ensure quantitative extractions, the
Since the late 1970s the central government of China has initiated several ecological environmental protection projects. The most significant of these has been the tui geng huan lin (returning cultivated land to forest and pasture) project in operation since the late 1990s. China's northwest region is characterized by lack of water resources, yet such resources are of vital importance. There is sc
We studied long-term trends and the yearly variation in mean spring passage time in 36 passerine bird species trapped at Ottenby Bird Observatory in south-eastern Sweden. Between the years 1952-2002, data were available for 22-45 years depending on species. Most long-distance migrant species passed progressively earlier over the study period (range: 2.5 days earlier to 0.7 days later per 10 years,
The commercially available preparation of beta-galactosidase from Bacillus circulans, known as Biolacta FN5, has been extensively used in the production of prebiotic galactooligosaccharides (GOS). This study focuses on characterizing the production of GOS in two reaction systems: 10% lactose (w/v) in buffer and skim milk. Analysis of the temperature dependence of the GOS yield along with the relat
Human activity often causes a decline in the local density of plant populations. Below some critical lower density, populations may suffer a progressive decline in reproductive success because of the difficulties associated with finding suitable mates. Therefore, to conserve endangered plant species it is necessary to understand in greater detail how changes in population density affect different
The aim of this study was to determine whether muscle fibre degeneration brought about by chronic low-frequency electrical stimulation was related to the pattern and frequency of stimulation. Rabbit fast-twitch muscles, tibialis anterior and extensor digitorum longus, were stimulated for 9 days with pulse trains ranging in frequency from 1.25 Hz to 10 Hz. Histological data from these muscles were
The power expenditure of flapping flight in birds is characterised by a U-shaped function of speed through the air. From this relationship and the assumption of limited power available from flight muscles, it is possible to predict changes in the birds' airspeed in relation to external factors such as wind. These predictions are derived from flight mechanical theory and optimality criteria concern
Non-invasive documentation of historic façades with fluorescence lidar techniques can provide helpful information for the cultural heritage sector, especially when large areas outdoors are to be examined. This paper presents a case study on the Coliseum, Rome, where both cleaned and heavily soiled areas of the monument were scanned and analysed with two fluorescence lidar systems. Biodeterioration
Popular Abstract in Swedish Den främsta orsaken till att cancer kan leda till döden är att tumörceller växer in i angränsande vävnad (invasiv) och tar sig in i blodet eller lymfsystemet och på så sätt sprids (metastaserar) till andra ställen i kroppen och stör funktionen i livsviktiga organ dvs tumören får ett aggressivt växtsätt. Det är därför viktigt, både ur prognostisk och terapeutisk synvinkeThe progressive process of tumour invasion and generation of metastases is the primary cause of death for most patients with cancer. Some of the regulatory components of this progressive process are adhesion, migration, and proteolysis. Urokinase -type plasminogen activator (u-PA) is a serine protease associated with tissue remodelling, cellular invasiveness, matrix degradation, angiogenesis, and
In this paper, we discuss the internet low bit rate codec (iLBC) with an emphesis on the frame-independent longterm prediction. The frame-independent long-term prediction is a method to exploit pitch-lag correlations in the encoding of speech without suffering multiple-frame speech degradation in connection with transmission loss. We present mean opinion scores for the iLBC codec and show by means
To obtain knowledge about combustion mechanisms operating in the ammoxidation of toluene, the formation of carbon oxides was studied over a Ti02(B)-supported vanadium oxide catalyst with monolayer loading. The partial pressures of reactants were varied and kinetic rate expressions, completely describing experimental data, were derived. A comparison of the expressions obtained with those for the fo
