Effect of Application of Farmyard Manure to Ley on Forage Yield and Quality of Grass Silage

A two-year field trial was performed on ley near Uppsala, Sweden, with the following treatments (3 plots/treatment): A, no manure or fertiliser; B, manure applied in Oct.; C, manure applied in Oct. followed by rolling plots in May; D, manure applied in May; E, mineral fertiliser only. Apart from cattle manure, plots allocated to treatments B, C and D received the same amount of mineral nutrients as treatment E. The objective of this experiment was to get an indication of how different times of manure application (before or after the growth period) affected forage yields and the quality of the resulting silage. Annual forage yields (2 cuts/year) did not differ significantly in either year among treatments that received manure. Only the unfertilised control treatment (A) had a significantly lower yield. No differences were found between treatments that received only mineral fertilisers (E) or mineral fertilisers and manure (B, C and D). The 1998 ensiling experiment resulted in a very low overall silage quality, indicated by excessive formation of ammonia and very high counts of Clostridium spores (\u3e 106 cfu/g silage). In 1999, the best silage, with the lowest counts of Clostridium spores (\u3c 50 cfu/g), was produced from plots, which received manure in Oct. and were rolled in May (C). The same treatment without rolling in May (B) resulted in silage with a significantly higher pH, more butyric acid, and more Clostridium spores (\u3e 105 cfu/g). Other silage from manured plots, particularly that made from unchopped forage, also had high counts of Clostridium spores

Differences across the ITCZ in the chemical characteristics of the Indian Ocean MBL aerosol during INDOEX

International audienceThe water soluble inorganic part of the sub-micrometer aerosol was measured from two research vessels over the Indian Ocean during the winter monsoon season (February and March) as part of the INDOEX project in 1998 and 1999. Additional measurements were made of gas phase SO2 from one of the vessels in 1999. All samples collected north of the Inter Tropical Convergence Zone, ITCZ, were clearly affected by continental, anthropogenic sources. A sharp transition occurred across the ITCZ with concentrations of nss-SO42-, NH4+ and nss-K+ being lower by a factor of 7-15, >20 and >40, respectively, on the southern side of the ITCZ. The contribution from DMS to the sub-micrometer nss-SO42- was estimated to be up to 40% in clean air north of the ITCZ but less than 10% in polluted air originating from India. South of the ITCZ virtually all nss-SO42- was likely to be derived from oxidation of DMS. The concentration of SO2 decreased rapidly with distance from the Indian coast, the molar ratio SO2/nss-SO42- reaching values below 5% after 35 h travel time over the ocean. Surprisingly, MSA, which is derived from DMS, also showed higher concentrations in the sub-micrometer aerosol north of the ITCZ than south of it. This could be explained by the larger sub-micrometer surface area available north of the ITCZ for the condensation of MSA. South of the ITCZ a major part of the MSA was found on the super-micrometer particles. An analysis based on the air trajectories showed that systematic variation in the observed concentrations was associated with variations in the transport from source regions. For example, differences in time since air parcels left the Arabian or Indian coasts was shown to be an important factor for explaining the substantial differences in absolute concentrations

Interhemispheric differences in the chemical characteristics of the Indian Ocean aerosol during INDOEX

International audienceThe water soluble inorganic part of the sub-micrometer aerosol was measured from two research vessels over the Indian Ocean during the winter monsoon season (February and March) as part of the INDOEX project in 1998 and 1999. Additional measurements were made of gas phase SO2 from one of the vessels in 1999. All samples collected north of the ITCZ were clearly affected by continental, anthropogenic sources. A sharp transition occurred across the ITCZ with concentrations of nss-SO42, NH4+ and nss-K+ being lower by a factor of 7--15, >20 and >40, respectively, on the southern side of the ITCZ. The contribution from DMS to the sub-micrometer nss-SO42 was estimated to be up to 40% in clean air north of the ITCZ but less than 10% in polluted air originating from India. South of the ITCZ virtually all nss-SO42 was likely to be derived from oxidation of DMS. The concentration of \chem{SO_2} decreased rapidly with distance from the Indian coast, the ratio \SO2nss-SO42 reaching values below 5% after 35 h travel time over the ocean. Surprisingly, MSA, which is derived from DMS, also showed higher concentrations in the sub-micrometer aerosol north of the ITCZ than south of it. This could be explained by the larger sub-micrometer surface area available north of the ITCZ for the condensation of MSA. South of the ITCZ a major part of the MSA was found on the super-micrometer particles. The total amount of MSA, on both sub-micrometer and super-micrometer particles, varied little across the ITCZ. An analysis based on the air trajectories showed that systematic variation in the observed concentrations was associated with variations in the transport from source regions. For example, differences in time since air parcels left the Arabian or Indian coasts was shown to be an important factor for explaining the substantial differences in absolute concentrations

Mathematical modelling of clinical applications in fluid therapy

Background: This thesis presents a new application of fluid kinetic analysis using mathematical tools to evaluate fluid therapy problems. Several models were developed to mathematically handle fluid distribution concerning bleeding and anaesthesia, arterio-venous differences in plasma dilution, peripheral fluid accumulation and differences in fluid distribution among young and elderly patients. Non-linear regression models were used to fit equations to sampled haemoglobin data. Methods: I: Six chronically instrumented sheep were subjected to four randomly ordered experiments while conscious or during anesthesia with isoflurane. After plasma volume measurement 15% or 45% of the blood volume was withdrawn. To quantify transcapillary refill, mass balance and kinetic calculations utilized repeated measurements of haemoglobin concentration. II: Fifteen volunteers received an intravenous (iv) infusion of 15 mL/kg of lactated Ringer s solution during 10 min. Simultaneous arterial and venous blood haemoglobin (Hb) samples were obtained and Hb concentrations measured. III: Ten healthy female non-pregnant volunteers participated. The protocol included an infusion of acetated Ringer s solution, 25 ml/kg over 30 minutes. Blood samples were repeatedly. A standard bladder catheter was continuously monitoring urine excretion. Plasma dilution, peripheral accumulation and urine output were modelled simultaneously. IV: Twenty four volunteers participated. Two age groups, a young group (age 18-25) and an elderly group (age 70-90) were formed. On separate occasions, the subjects in both groups were given a crystalloid 25 mg/ml glucose solution, either orally (ORAL) or intravenously (IV) in a crossover design with at least two weeks in between. On each occasion, the subjects got 7 ml/kg of the crystalloid solution during 15 minutes. Results: I: After either normotensive or hypotensive hemorrhage, transcapillary refill occurred more rapidly during the first 40 min than during the next 140 min (p < 0.001). In conscious sheep, at 180 min, 57% and 42% of the bled volume had been restored after normotensive and hypotensive hemorrhage, respectively, in contrast to only 13% and 27% (p < 0.001) in isoflurane-anesthetized sheep. Using parameters derived from kinetic analysis, simulations illustrate that both the hydrostatic and colloid osmotic forces are weaker in the presence of isoflurane than in the awake state. II: The AV difference in plasma dilution was only positive during the infusion and for 2.5 min thereafter, which represents the period of net flow of fluid from plasma to tissue. Kinetic analysis showed that volume expansion of the peripheral fluid space began to decrease 14 min (arterial blood) and 20 min (venous blood) after the infusion ended. III: Maximum urinary output rate was found to be 19 (13 31) ml/min. The subjects were likely to accumulate three times as much of the infused fluid peripherally as centrally; Elimination efficacy, Eeff, was 24 (5 35) and the basal elimination kb was 1.11 (0.28 2.90). The total time delay Ttot of urinary output was estimated to 17 (11 - 31) min. IV: The lag-time of glucose given orally was estimated to be 17 (8 25) min for the younger group and 18 (13 22) min for the elderly. For fluid, the lag-time was estimated to 29 (21 - 34) min for the younger and 25 (16 39) min for the elderly. Conclusions: Final conclusion is that mathematical modelling of clinical applications can be done in several different clinical settings and will improve the understanding of fluid distribution. It is possible to continuously model fluid behaviour in the body as seen in Papers II-III. This should enhance the understanding of accumulating oedema in the body which is an apparent problem for all clinicians

Radiative forcing of climate

An update of the scientific discussions presented in Chapter 2 of the Intergovernmental Panel on Climate Change (IPCC) report is presented. The update discusses the atmospheric radiative and chemical species of significance for climate change. There are two major objectives of the present update. The first is an extension of the discussion on the Global Warming Potentials (GWP's), including a reevaluation in view of the updates in the lifetimes of the radiatively active species. The second important objective is to underscore major developments in the radiative forcing of climate due to the observed stratospheric ozone losses occurring between 1979 and 1990

Theory and observations: Model simulations of the period 1955-1985

The main objective of the theoretical studies presented here is to apply models of stratospheric chemistry and transport in order to understand the processes that control stratospheric ozone and that are responsible for the observed variations. The model calculations are intended to simulate the observed behavior of atmospheric ozone over the past three decades (1955-1985), for which there exists a substantial record of both ground-based and, more recently, satellite measurements. Ozone concentrations in the atmosphere vary on different time scales and for several different causes. The models described here were designed to simulate the effect on ozone of changes in the concentration of such trace gases as CFC, CH4, N2O, and CO2. Changes from year to year in ultraviolet radiation associated with the solar cycle are also included in the models. A third source of variability explicitly considered is the sporadic introduction of large amounts of NO sub x into the stratosphere during atmospheric nuclear tests

Temperature-dependent quantum pair potentials and their application to dense partially ionized hydrogen plasmas

Extending our previous work \cite{filinov-etal.jpa03ik} we present a detailed discussion of accuracy and practical applications of finite-temperature pseudopotentials for two-component Coulomb systems. Different pseudopotentials are discussed: i) the diagonal Kelbg potential, ii) the off-diagonal Kelbg potential iii) the {\em improved} diagonal Kelbg potential, iv) an effective potential obtained with the Feynman-Kleinert variational principle v) the ``exact'' quantum pair potential derived from the two-particle density matrix. For the {\em improved} diagonal Kelbg potential a simple temperature dependent fit is derived which accurately reproduces the ``exact'' pair potential in the whole temperature range. The derived pseudopotentials are then used in path integral Monte Carlo (PIMC) and molecular dynamics (MD) simulations to obtain thermodynamical properties of strongly coupled hydrogen. It is demonstrated that classical MD simulations with spin-dependent interaction potentials for the electrons allow for an accurate description of the internal energy of hydrogen in the difficult regime of partial ionization down to the temperatures of about $60 000$ K. Finally, we point out an interesting relation between the quantum potentials and effective potentials used in density functional theory.Comment: 18 pages, 11 figure

Urine culture doubtful in determining etiology of diffuse symptoms among elderly individuals: a cross-sectional study of 32 nursing homes

Background: The high prevalence of bacteriuria in elderly individuals makes it difficult to know if a new symptom is related to bacteria in the urine. There are different views concerning this relationship and bacteriuria often leads to antibiotic treatments. The aim of this study was to investigate the relationship between bacteria in the urine and new or increased restlessness, fatigue, confusion, aggressiveness, not being herself/himself, dysuria, urgency and fever in individuals at nursing homes for elderly when statistically considering the high prevalence of asymptomatic bacteriuria in this population.\ud \ud Methods: In this cross-sectional study symptoms were registered and voided urine specimens were collected for urinary cultures from 651 elderly individuals. Logistic regressions were performed to evaluate the statistical correlation between bacteriuria and presence of a symptom at group level. To estimate the clinical relevance of statistical correlations at group level positive and negative etiological predictive values (EPV) were calculated.\ud \ud Results: Logistic regression indicated some correlations at group level. Aside from Escherichia coli in the urine and not being herself/himself existing at least one month, but less than three months, EPV indicated no clinically useful correlation between any symptoms in this study and findings of bacteriuria.\ud \ud Conclusions: Urinary cultures provide little or no useful information when evaluating diffuse symptoms among elderly residents of nursing homes. Either common urinary tract pathogens are irrelevant, or urine culture is an inappropriate test