Ecosystem properties and principles of living systems as foundation for sustainable agriculture – Critical reviews of environmental assessment tools, key findings and questions from a course process

With increasing demands on limited resources worldwide, there is a growing interest in sustainable patterns of utilisation and production. Ecological agriculture is a response to these concerns. To assess progress and compliance, standard and comprehensive measures of resource requirements, impacts and agro-ecological health are needed. Assessment tools should also be rapid, standardized, userfriendly, meaningful to public policy and applicable to management. Fully considering these requirements confounds the development of integrated methods. Currently, there are many methodologies for monitoring performance, each with its own foundations, assumptions, goals, and outcomes, dependent upon agency agenda or academic orientation. Clearly, a concept of sustainability must address biophysical, ecological, economic, and sociocultural foundations. Assessment indicators and criteria, however, are generally limited, lacking integration, and at times in conflict with one another. A result is that certification criteria, indicators, and assessment methods are not based on a consistent, underlying conceptual framework and often lack a management focus. Ecosystem properties and principles of living systems, including self-organisation, renewal, embeddedness, emergence and commensurate response provide foundation for sustainability assessments and may be appropriate focal points for critical thinking in an evaluation of current methods and standards. A systems framework may also help facilitate a comprehensive approach and promote a context for meaningful discourse. Without holistic accounts, sustainable progress remains an illdefined concept and an elusive goal. Our intent, in the work with this report, was to use systems ecology as a pedagogic basis for learning and discussion to: - Articulate general and common characteristics of living systems. - Identify principles, properties and patterns inherent in natural ecosystems. - Use these findings as foci in a dialogue about attributes of sustainability to: a. develop a model for communicating scientific rationale. b. critically evaluate environmental assessment tools for application in land-use. c. propose appropriate criteria for a comprehensive assessment and expanded definition of ecological land use

ELVIS - ELectromagnetic Vector Information Sensor

The ELVIS instrument was recently proposed by the authors for the Indian Chandrayaan-1 mission to the Moon and is presently under consideration by the Indian Space Research Organisation (ISRO). The scientific objective of ELVIS is to explore the electromagnetic environment of the moon. ELVIS samples the full three-dimensional (3D) electric field vector, E(x,t), up to 18 MHz, with selective Nyqvist frequency bandwidths down to 5 kHz, and one component of the magnetic field vector, B(x,t), from a few Hz up to 100 kHz.As a transient detector, ELVIS is capable of detecting pulses with a minimum pulse width of 5 ns. The instrument comprises three orthogonal electric dipole antennas, one magnetic search coil antenna and a four-channel digital sampling system, utilising flexible digital down conversion and filtering together with state-of-the-art onboard digital signal processing.Comment: 8 pages, 3 figures. Submitted to the DGLR Int. Symposium "To Moon and Beyond", Bremen, Germany, 2005. Companion paper to arXiv:astro-ph/050921

The Effects of Pregnenolone 16α-Carbonitrile Dosing on Digoxin Pharmacokinetics and Intestinal Absorption in the Rat

The effect of Pgp induction in rats by pregnenolone 16α-carbonitrile (PCN) (3 days, 35 mg/kg/d, p.o.) on digoxin pharmacokinetics and intestinal transport has been assessed. After intravenous or oral digoxin dosing the arterial and hepatic portal vein (oral) AUC(0-24h) were significantly reduced by PCN pre-treatment. Biliary digoxin clearance increased 2-fold following PCN treatment. PCN significantly increased net digoxin secretion (2.05- and 4.5-fold respectively) in ileum and colon but not in duodenum or jejunum. This increased secretion correlated with increased Pgp protein expression in ileum and colon. Both intestinal and biliary excretion therefore contribute to altered digoxin disposition following PCN

Statistical properties of ionospheric stimulated electromagnetic emissions

We have analysed the statistical properties of the stimulated electromagnetic emissions (SEE) spectral features in the steady state, reached after a long period of continuous HF pumping of the ionosphere in experiments performed at the Sura ionospheric radio research facility in Russia. Using a digital filter bank method, we have been able to analyse complex valued signals within narrow frequency bands. Each of the SEE spectral features are thereby separated into a number of narrow spectral components. Statistical tests were performed for all these spectral components and the distributions of the spectral amplitudes and phases were evaluated. Also, a test for sinusoidal components was performed. These tests showed that all observed SEE features were indistinguishable from coloured Gaussian noise. The test results exclude that the SEE features can be the result of a single isolated coherent process, but does not rule out that there could be many statistically independent parametric wave-wave processes taking place simultaneously at various parts of the HF-pumped ionosphere, as long as the superposition from all these is incoherent. Furthermore, from the test results, we cannot exclude the possibility that the waveforms of some, or all, of the SEE features may be chaotic

Activation of NF- B protein prevents the transition from juvenile ovary to testis and promotes ovarian development in Zebrafish

Testis differentiation in zebrafish involves juvenile ovary to testis transformation initiated by an apoptotic wave. The molecular regulation of this transformation process is not fully understood. NF-κB is activated at an early stage of development and has been shown to interact with steroidogenic factor-1 in mammals, leading to the suppression of anti-Müllerian hormone (Amh) gene expression. Because steroidogenic factor-1 and Amh are important for proper testis development, NF-κB-mediated induction of anti-apoptotic genes could, therefore, also play a role in zebrafish gonad differentiation. The aim of this study was to examine the potential role of NF-κB in zebrafish gonad differentiation. Exposure of juvenile zebrafish to heat-killed Escherichia coli activated the NF-κB pathways and resulted in an increased ratio of females from 30 to 85%. Microarray and quantitative real-time-PCR analysis of gonads showed elevated expression of NF-κB-regulated genes. To confirm the involvement of NF-κB-induced anti-apoptotic effects, zebrafish were treated with sodium deoxycholate, a known inducer of NF-κB or NF-κB activation inhibitor (NAI). Sodium deoxycholate treatment mimicked the effect of heat-killed bacteria and resulted in an increased proportion of females from 25 to 45%, whereas the inhibition of NF-κB using NAI resulted in a decrease in females from 45 to 20%. This study provides proof for an essential role of NF-κB in gonadal differentiation of zebrafish and represents an important step toward the complete understanding of the complicated process of sex differentiation in this species and possibly other cyprinid teleosts as well

Excess breast cancer risk and the role of parity, age at first childbirth and exposure to radiation in infancy

Exposure to ionizing radiation is a known risk factor for breast cancer and the fertility pattern is a recognized modifier of breast cancer risk. The aim of this study was to elucidate the interaction between these 2 factors. This study is based on a Swedish cohort of 17 202 women who had been irradiated for skin haemangiomas in infancy between 1920 and 1965. The mean age at treatment was 6 months and the median breast dose was 0.05 Gy (range 0–35.8 Gy). Follow-up information on vital status, parity, age at first childbirth and breast cancer incidence was retrieved through record linkage with national population registers for the period 1958–1995. Analyses of excess relative risk (ERR) models were performed using Poisson regression methods. In this cohort, the fertility pattern differed from that in the Swedish population, with significantly fewer childbirths overall and before 25 years of age but more childbirth after that age. There were 307 breast cancers in the cohort and the standardized incidence ratio (SIR) was 1.22 (95% CI 1.09–1.36). A linear dose–response model with stratification for fertility pattern and menopausal status resulted in the best fit of the data. ERR/Gy was 0.33 (95% CI 0.17–0.53). In absolute terms this means an excess of 2.1 and 5.4 cases per Gy per 104breast-years in the age groups 40–49 and 50–59 years respectively. The fertility pattern influenced the breast cancer risk in this irradiated population in a similar way to that observed in other studies. SIR at dose = 0 was highest, 2.31, among postmenopausal nulliparous women (95% CI 1.48–3.40, n = 62). SIR at dose = 0 was lowest in pre- or postmenopausal women with a first childbirth before 25 years of age; 0.89 (0.71–1.09) and 0.88 (0.58–1.25) respectively. Thus, in addition to the dose–effect response in the cohort, part of the breast cancer excess could be explained by a different fertility pattern. The estimates of ERR/Gy for the various categories of age at first childbirth, number of children, menopausal status and ovarian dose were very similar, contradicting any interaction effects on the scale of relative risk. © 2001 Cancer Research Campaign http://www.bjcancer.co

The Distribution of Redshifts in New Samples of Quasi-stellar Objects

Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in $\log(1+z)$. The first of these comprises 57 different redshifts among all known close pairs or multiple QSOs, with image separations $\leq$ 10\arcsec, and the second consists of 39 QSOs selected through their X-ray emission and their proximity to bright comparatively nearby active galaxies. The redshift distributions of the samples are found to exhibit distinct peaks with a periodic separation of $\sim 0.089$ in $\log(1+z)$ identical to that claimed in earlier samples but now extended out to higher redshift peaks $z = 2.63, 3.45$ and 4.47, predicted by the formula but never seen before. The periodicity is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogues. It is present in these three datasets at an overall significance level $10^{-5}$ - $10^{-6}$, and appears not to be explicable by spectroscopic or similar selection effects. Possible interpretations are briefly discussed.Comment: submitted for publication in the Astronomical Journal, 15 figure

A Quantum solution to the Byzantine agreement problem

We present a solution to an old and timely problem in distributed computing. Like Quantum Key Distribution (QKD), quantum channels make it possible to achieve taks classically impossible. However, unlike QKD, here the goal is not secrecy but agreement, and the adversary is not outside but inside the game, and the resources require qutrits.Comment: 4 pages, 1 figur

A measurement of the differential cross section for the two-body photodisintegration of 3He at theta_LAB = 90deg using tagged photons in the energy range 14 -- 31 MeV

The two-body photodisintegration of 3He has been investigated using tagged photons with energies from 14 -- 31 MeV at MAX-lab in Lund, Sweden. The two-body breakup channel was unambiguously identified by the (nonsimultaneous) detection of both protons and deuterons. This approach was made feasible by the over-determined kinematic situation afforded by the tagged-photon technique. Proton- and deuteron-energy spectra were measured using four silicon surface-barrier detector telescopes located at a laboratory angle of 90deg with respect to the incident photon-beam direction. Average statistical and systematic uncertainties of 5.7% and 6.6% in the differential cross section were obtained for 11 photon-energy bins with an average width of 1.2 MeV. The results are compared to previous experimental data measured at comparable photon energies as well as to the results of two recent Faddeev calculations which employ realistic potential models and take into account three-nucleon forces and final-state interactions. Both the accuracy and precision of the present data are improved over the previous measurements. The data are in good agreement with most of the previous results, and favor the inclusion of three-nucleon forces in the calculations.Comment: 12 pages, 13 figures; further Referee comments addresse