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Selected AbstractsThe transition to an advanced organic economy: half a millennium of English agriculture1ECONOMIC HISTORY REVIEW, Issue 3 2006E. A. WRIGLEY All organic economies were subject to constraints upon growth for reasons familiar to the classical economists, but their relative success in coping with these constraints differed substantially. This is visible both when comparing different areas at the same point in time and when comparing the circumstances of a given economy at different points in time. In this article the state of the English economy in 1300 is compared with its state in 1800. At the former date the balance between output and population was unfavourable. A run of poor harvests spelled grave and widespread suffering. Five hundred years later this had ceased to be true. The particular focus of the article is upon the significance of a rising level of productivity per head in agriculture, not simply in supplying food but in providing the raw materials and energy needed if industry and transport were to expand. In the circumstances of an organic economy both were heavily dependent upon the ,surplus' made available by a productive agriculture after meeting the needs of the population for food. [source] Protection of lodgepole pines from mass attack by mountain pine beetle, Dendroctonus ponderosae, with nonhost angiosperm volatiles and verbenoneENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2001D.P.W. Huber Abstract A number of angiosperm nonhost volatiles (NHVs) and green leaf volatiles (GLVs) were tested alone and as supplements to the antiaggregation pheromone, verbenone, for their ability to disrupt attack by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), on lodgepole pine, Pinus contorta Dougl. ex Loud. var. latifolia Engel. Preliminary experiments led to a refined NHV blend [benzyl alcohol, guaiacol, benzaldehyde, nonanal, salicylaldehyde, and conophthorin] and a refined GLV blend [(Z)-3-hexen-1-ol and (E)-2-hexen-1-ol]. In a 20-replicate experiment, NHV and GLV groups both singly, and verbenone alone, significantly reduced MPB mass attack on pheromone-baited trees and on trees within 5 m of the pheromone-baited trees. Both blends in combination with verbenone reduced the number of mass attacked, baited trees to three out of 20 compared to 20 out of 20 of the baited controls. Each binary combination was also effective at reducing mass attack. In these experiments, all tested repellents were released from devices stapled to trees at the same point as the pheromone bait, suggesting that the repellency could have been to a point source, rather than to the whole tree. Therefore, in two further experiments bands of release devices were wrapped around the treated trees and the pheromone bait was removed from the treated trees. In one experiment, when the aggregation pheromone bait was suspended between pairs of trees treated with the NHV blend plus GLV blend plus verbenone, only three out of 25 treated pairs had mass attack on at least one member of the pair. In the other 60-replicate experiment, with no pheromone baits present, attack occurred on 13 untreated and 11 banded trees, all in the path of a large advancing infestation. However, the mean attack density on the banded trees was significantly reduced to a level below the 40 attacks m,2 of bark surface required to kill a healthy lodgepole pine. As a result of these experiments, operational trials are recommended. [source] Closed-loop identification of the time-varying dynamics of variable-speed wind turbinesINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 1 2009J. W. van Wingerden Abstract The trend with offshore wind turbines is to increase the rotor diameter as much as possible to decrease the costs per kWh. The increasing dimensions have led to the relative increase in the loads on the wind turbine structure. Because of the increasing rotor size and the spatial load variations along the blade, it is necessary to react to turbulence in a more detailed way: each blade separately and at several separate radial distances. This combined with the strong nonlinear behavior of wind turbines motivates the need for accurate linear parameter-varying (LPV) models for which advanced control synthesis techniques exist within the robust control framework. In this paper we present a closed-loop LPV identification algorithm that uses dedicated scheduling sequences to identify the rotational dynamics of a wind turbine. We assume that the system undergoes the same time variation several times, which makes it possible to use time-invariant identification methods as the input and the output data are chosen from the same point in the variation of the system. We use time-invariant techniques to identify a number of extended observability matrices and state sequences that are inherent to subspace identification identified in a different state basis. We show that by formulating an intersection problem all states can be reconstructed in a general state basis from which the system matrices can be estimated. The novel algorithm is applied on a wind turbine model operating in closed loop. Copyright © 2008 John Wiley & Sons, Ltd. [source] Preventing crown collisions increases the crown cover and leaf area of maturing lodgepole pineJOURNAL OF ECOLOGY, Issue 3 2006SHAWN X. MENG Summary 1Crown collisions induced by tree sway are hypothesized to reduce crown closure and leaf area in maturing cold temperate forests. These declines are thought to lead to the decline in productivity when a stand ages. 2We tethered groups of lodgepole pine (Pinus contorta Dougl. Ex Loud. Var. latifolia Engelm.) trees in a web pattern at 10 m height, in four 15-m tall stands in western Alberta, Canada, to determine whether preventing crown collisions would increase crown cover and leaf area. 3The stands all had less than 65% crown closure at the beginning of study. Photographs of the canopy were taken in each control and webbed plot in 1998 and at the same point in 2004. Six years after webbing, crown cover had increased by 14.4%, compared to a 2.1% increase for the control plots. 4Webbing also resulted in significant increases in mean branch length, leaf area per branch and foliage density of individual branches from top and middle sections of the crown. Polishing of branches, caused by chronic contact with adjacent trees, was three times as common on control trees compared to webbed trees. The mean leaf area per tree was larger for the webbed trees. 5Crowns of webbed trees were more symmetrical than those of control trees. Trees from webbed plots, however, had a decline in leaf area density. The branches of control trees were typically curved upward with twigs pointed inward, making the crowns more compact compared to the outwardly expanding crowns of trees from the webbed plots. 6The fact that crowns expanded laterally after webbing, despite little change in light regime, provides strong evidence against the hypothesis that loss of crown closure in maturing stands is caused by a lack of light. 7The study indicates that the decline in crown closure and leaf area in maturing and tall stands is at least partly related to wind-induced sway of trees abrading the edges of crowns. [source] Centenarians , a useful model for healthy aging?AGING CELL, Issue 3 2009A 29-year follow-up of hospitalizations among 40 000 Danes born in 190 Summary Centenarians surpass the current human life expectancy with about 20,25 years. However, whether centenarians represent healthy aging still remains an open question. Previous studies have been hampered by a number of methodological shortcomings such as a cross-sectional design and lack of an appropriate control group. In a longitudinal population-based cohort, it was examined whether the centenarian phenotype may be a useful model for healthy aging. The study was based on a complete follow up of 39 945 individuals alive in the Danish 1905 birth cohort on January 1, 1977 identified through the Danish Civil Registration System (DCRS). Data from the Danish Demographic Database and The Danish National Patient Register (in existence since 1977) were used. The 1905 cohort was followed up from 1977 through 2004 with respect to hospitalizations and number of hospital days. Survival status was available until December 2006. Danish centenarians from the 1905 cohort were hospitalized substantially less than their shorter-lived contemporaries at the same point in time during the years 1977 through 2004. For example, at age 71,74, the proportion of nonhospitalized centenarians was 80.5% compared with 68.4% among individuals who died in their early 80s. This trend was evident in both sexes. As a result of their lower hospitalization rates and length of stay in hospital compared with their contemporaries, who died at younger ages, Danish centenarians represent healthy agers. Centenarians constitute a useful study population in the search for fixed traits associated with exceptional longevity, such as genotype. [source] Investigation into the protein composition of human tear fluid using centrifugal filters and drop coating deposition Raman spectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2009Jacob Filik Abstract Drop coating deposition Raman spectroscopy (DCDRS) is a simple method of analysing weak protein solutions. This study is another step in evaluating the analysis of tear fluid by DCDRS as a future medical diagnostic technique. The main aims of this study are to determine whether the DCDR spectra from tear samples contain signals from more than one protein (so relative levels can be measured) and, if so, are the proteins homogeneously distributed in the dried ring of the deposited material. Tear samples were collected from four healthy volunteers and pooled prior to analysis. Proteins were separated by mass into three groups using centrifugal filters. These groups contained proteins with (1) masses greater than 100 kDa, (2) masses between 100 and 50 kDa and (3) masses between 50 and 3 kDa. DCDR spectra from each of these protein group solutions displayed significant differences, confirming that the mass separation had been successful. When used as basis vectors for least-squares fitting, these spectra (and that of urea) produced excellent fits to the normal tear spectra. Least-squares fitting of spectra from the same point on a single sample and from several drops of the same sample showed that the tear DCDR spectra were highly reproducible. Raman point mapping of the tear ring showed significant radial ring variation, especially towards the outer edge of the ring. The specific peak changes in the protein signal across the ring suggested that the difference in the outer edge was due to protein desiccation as opposed to inhomogeneous protein deposition. Copyright © 2008 John Wiley & Sons, Ltd. [source] Rendez-vous search on a rectangular latticeNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 5 2007William H. Ruckle Abstract In a rendez-vous search two or more teams called seekers try to minimize the time needed to find each other. In this paper, we consider s seekers in a rectangular lattice of locations where each knows the configuration of the lattice, the distribution of the seekers at time 0, and its own location, but not the location of any other. We measure time discretely, in turns. A meeting takes place when the two seekers reach the same point or adjacent points. The main result is that for any dimension of lattice, any initial distribution of seekers there are optimal strategies for the seekers that converge (in a way we shall make clear) to a center. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 [source] Octahedral tilting in cation-ordered Jahn,Teller distorted perovskites , a group-theoretical analysisACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2010Christopher J. Howard Computer-based group-theoretical methods are used to enumerate structures arising in A2BB,X6 perovskites, with either rock-salt or checkerboard ordering of the B and B, cations, under the additional assumption that one of these two cations is Jahn,Teller active and thereby induces a distortion of the BX6 (or B,X6) octahedron. The requirement to match the pattern of Jahn,Teller distortions to the cation ordering implies that the corresponding irreducible representations should be associated with the same point in the Brillouin zone. Effects of BX6 (and B,X6) octahedral tilting are included in the usual way. Finally, an analysis is presented of more complex models of ordering and distortion as might lead to the doubling of the long axis of the common Pnma perovskite, observed in systems such as Pr1,,,xCaxMnO3 (x, 0.5). The structural hierarchies derived in this work should prove useful in interpreting experimental results. [source] Impact of splenectomy on circulating T-lymphocyte subsets in stage III gastric cancerANZ JOURNAL OF SURGERY, Issue 6 2002Min Young Cho Background: The role of splenectomy remains unclear in patients with gastric cancer who undergo total gastrectomy. The aim of this study was to prospectively evaluate the impact of splenectomy on circulating T-lymphocyte subsets and survival in advanced gastric cancer. Methods: Analysis of lymphocyte subsets was performed in 40 patients with American Joint Committee on Cancer (AJCC) stage III gastric adenocarcinoma located on the upper one-third of the stomach, who underwent a curative total gastrectomy with or without splenectomy. Circulating T-lymphocyte subsets were measured on venous blood by using flow cytometry and monoclonal antibodies at preoperative day 1, and postoperative months 1, 3, 6, 12 and 18. Results: The proportion of lymphocytes and the values of CD3, CD8, CD16 and CD25 subsets were higher in the splenectomy group of patients at postoperative month 3. In the spleen preservation group at the same point of treatment, the proportion of granulocytes and the values of CD4 and CD4 : CD8 ratio were higher. Except for CD16 levels, all T-lymphocyte subsets showed no significant difference between splenectomy and spleen preservation groups after postoperative month 3. Increased CD16 levels in the splenectomy group were not associated with improvement in patients' 5-year survival rates. Conclusion: These results suggest that the long-term impact of splenectomy does not play an important role in postoperative quantitative changes of circulating T-lymphocyte subsets of patients with stage III gastric cancer who have undergone total gastrectomy. Furthermore, splenectomy does not give a prognostic benefit, based on tumour recurrence and survival of patients with proximal one-third gastric cancer who undergo total gastrectomy. [source] Assessing the spawning season in common dentex (Dentex dentex) using microsatellitesAQUACULTURE RESEARCH, Issue 12 2008Yaisel J Borrell Abstract A set of five variable microsatellite markers was used for the genetic characterization of two common dentex (Dentex dentex) broodstocks from an experimental hatchery and for the screening of the egg batches spawned during the complete spawn season in 2006. After parentage assignment, simulations were performed for the hatchery 1 broodstocks; the microsatellite set correctly assigned over 93% of descendants to parents when one parent was known and 80% when neither parent was known. Of the 261 eggs that the DNA was correctly amplified from, 254 were successfully assigned to a parental couple. More than one female or male took part (at the same point in time) in the spawning season. However, we observed ,dominant' individuals that produced high proportions of the descendants (unequal reproductive success) in all the sampling periods, although the contributions of these dominant individuals could change over time. This phenomenon reduces the effective breeding numbers, and could lead to inbreeding if this factor is not taken into account when the next parental generation is obtained. This factor should also be considered in aquaculture selection programmes because the dominant breeders may not be the most interesting individuals for commercial or productive schemes. [source] Large scale wildlife monitoring studies: statistical methods for design and analysisENVIRONMETRICS, Issue 2 2002Kenneth H. Pollock Abstract Techniques for estimation of absolute abundance of wildlife populations have received a lot of attention in recent years. The statistical research has been focused on intensive small-scale studies. Recently, however, wildlife biologists have desired to study populations of animals at very large scales for monitoring purposes. Population indices are widely used in these extensive monitoring programs because they are inexpensive compared to estimates of absolute abundance. A crucial underlying assumption is that the population index (C) is directly proportional to the population density (D). The proportionality constant, ,, is simply the probability of ,detection' for animals in the survey. As spatial and temporal comparisons of indices are crucial, it is necessary to also assume that the probability of detection is constant over space and time. Biologists intuitively recognize this when they design rigid protocols for the studies where the indices are collected. Unfortunately, however, in many field studies the assumption is clearly invalid. We believe that the estimation of detection probability should be built into the monitoring design through a double sampling approach. A large sample of points provides an abundance index, and a smaller sub-sample of the same points is used to estimate detection probability. There is an important need for statistical research on the design and analysis of these complex studies. Some basic concepts based on actual avian, amphibian, and fish monitoring studies are presented in this article. Copyright © 2002 John Wiley & Sons, Ltd. [source] Raman spectroscopy of synthetic, geological and biological vaterite: a Raman spectroscopic studyJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2010U. Wehrmeister Abstract Raman spectroscopy was used to study vaterite samples of biological, geological and synthetic origin. The Raman band positions and the full width at half-maximum (FWHM) of the lattice modes and the internal modes of the carbonate ion of all specimens show no significant differences between vaterites of different origin. With increasing Mg concentrations, synthetic vaterite samples show increasing FWHM in the region of the lattice modes and the three ,1 bands, whereas no change in luminescence was detected. In contrast, in situ measurements of vaterite areas in freshwater cultured pearls (FWCPs) by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) together with the Raman spectra obtained at the same points show that the luminescence intensity in biological samples is affected by the magnesium content. The Raman spectroscopic features of vaterite and parisite-(Ce) are compared, and their similarities suggest that the structure of vaterite contains at least three crystallographically independent carbonate groups and similar carbonate group layers. A band at 263 cm,1 is observed for the first time in this study, whereas it could be demonstrated that bands previously reported at 130 and 190 cm,1 do not belong to vaterite. Copyright © 2009 John Wiley & Sons, Ltd. [source] Impact of Tips Preliver Transplantation for the Outcome PosttransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009G. P. Guerrini The effects of transjugular intrahepatic portocaval shunt (TIPS) on the survival of grafts and patients after liver transplantation (LTx) have only been documented in small series and with only a comparative description with non-TIPS recipients. We evaluated 61 TIPS patients who had a subsequent LTx and compared these with 591 patients transplanted with cirrhosis without TIPS. Pretransplant characteristics were similar between groups. Graft survival at 1, 3 and 5 years post-LTx was 85.2%, 77% and 72.1% (TIPS) and 75.3%, 69.8% and 66.1% (controls). Patient survival at the same points was 91.7%, 85% and 81.7%, respectively (TIPS) and 85.4%, 80.3% and 76.2% (controls). Cox regression showed the absence of TIPS pre-LTx, transfusion of >5 units of blood during LTx, intensive care unit (ICU) stay post-LTx >3 days and earlier period of transplant to be significantly associated with a worse patient and graft survival at 1 year. Migration of the TIPS stent occurred in 28% of cases, increasing the time on bypass during LTx, but was not related to graft or patient survival. TIPS may improve portal supply to the graft and reduce collateral flow, improving function. This may account for the improved adjusted graft and patient survival by Cox regression at 12 months. Long-term survival was not affected. [source] Acupuncture for the induction of labour: a double-blind randomised controlled studyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2010J Modlock Please cite this paper as: Modlock J, Nielsen B, Uldbjerg N. Acupuncture for the induction of labour: a double-blind randomised controlled study. BJOG 2010;117:1255,1261. Objective, To investigate whether acupuncture is effective for the induction of labour in post-term pregnancies. Design, A double-blind multicentre randomised controlled study. Settings, Aarhus University Hospital and Herning Regional Hospital, Denmark. Population, One hundred and twenty-five healthy women with uneventful pregnancies at gestational week 41+6 were randomised into two groups. Methods, The intervention group was given acupuncture twice on the same day at acupuncture point GV20 and bilaterally at points BL67, LI4 and SP6. The control group received sham acupuncture at the same points. Main outcome measures, At effect evaluation, which was carried out 24 hours after randomisation, the primary endpoint was labour or delivery. Results, The primary endpoint was achieved in seven women (12%) in the acupuncture group and eight women (14%) in the control group (P = 0.79). Stratification for parity and fetal gender did not alter the results. Conclusion, Under the treatment regimen investigated in this study, acupuncture for the induction of labour in post-term women at gestational age 41+6 weeks may not be effective. [source] | |||||||||||||||||||