bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of evidence‐based medicine on magnetic resonance spectroscopy
Authors: Lin Alexander P. , Tran Thao T. , Ross Brian D.
Published: June 2006

Magnetic resonance spectroscopy (MRS) is a robust, non‐invasive means of defining aspects of human neurochemistry. After more than two decades, it is clear that in addition to its scientific interest, MRS has diagnostic value in tumor diagnosis, prognosis, therapeutic outcome, dementia diagnosis and prognosis, multiple sclerosis, infections, trauma, development, stroke, perinatal ischemia, xenobiotics and inborn errors (as determined from a meta‐analysis included in this paper). However, in many healthcare systems, a new radiological technique requires evidence‐based medicine (EBM) before it is recommended for reimbursement. Much of the reason why MRS is thought to be non‐reimbursable in the USA is due to recent announcements that this 15‐year‐old technique is still considered ‘investigational’ by these EBM assessments. An analysis is presented of the technology assessments that brought about this situation. Based on the conclusions of the EBM assessments, strategies are suggested that involve all entities responsible for spectroscopy including the scientists' role in ensuring the future for clinical spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd.
Development of diffuse large B cell lymphoma during the maintenance therapy for B‐lineage acute lymphoblastic leukemia
Authors: Kato Itaru , Manabe Atsushi , Aoyama Chiaki , Kamiya Takahiro , Morimoto Tsuyoshi , Matsufuji Hiroshi , Suzuki Koyu , Kitagawa Yoshiro , Hori Toshinori , Tsurusawa Masahito , Kiyokawa Nobutaka , Junichiro Fujimoto , Hosoya Ryota
Published: June 2006

Non‐Hodgkin lymphoma (NHL) is a very rare complication of acute lymphoblastic leukemia (ALL). A Japanese boy presented with B‐lineage ALL at the age of 2.5. He was treated with chemotherapy for standard‐risk ALL. While he was receiving maintenance treatment 2 years and 9 months after the diagnosis of ALL, diffuse large B cell lymphoma (DLBL) was diagnosed from a biopsy of an abdominal mass. DLBL was treated by surgical resection followed by chemotherapy for 6 months. The patient has been free from the recurrence of ALL or DLBL for 16 months after the development of DLBL. Pediatr Blood Cancer 2007;48:230–232. © 2006 Wiley‐Liss, Inc.
Results from a rosuvastatin historical cohort study in more than 45 000 Dutch statin users, a PHARMO study
Authors: Goettsch W.G. , Heintjes E.M. , Kastelein J.J.P. , Rabelink T.J. , Johansson Saga , Herings R.M.C.
Published: June 2006

Purpose

Clinical benefits of statin therapy are accepted, but their safety profiles have been under scrutiny, particularly for the recently introduced statin, rosuvastatin, relating to serious adverse events involving muscle, kidney and liver. Therefore, a historical cohort study was performed to evaluate the association between rosuvastatin versus other statin use and the incidence of rhabdomyolysis, myopathy, acute renal failure and hepatic impairment.

Methods

Incident users of rosuvastatin or other statins in 2003–2004 and a cohort of patients not prescribed statins were included from the PHARMO database of >2 million Dutch residents. Cases of hospitalisations for myopathy, rhabdomyolysis, acute renal failure or hepatic impairment were identified for these cohorts. Potential cases were validated through a multi‐step process using data obtained from hospital records. Additionally, cases of all cause deaths were identified from certification alone.

Results

In 2003 and 2004, 10 147 incident rosuvastatin users, 37 396 incident other statin users and 99 935 patients without statin prescriptions were included. There were 26 validated outcome events in the three cohorts including one case each of myopathy (other statin group) and rhabdomyolysis (non‐treated group). There were no significant differences in the incidence of outcome events between rosuvastatin and other statin users.

Conclusion

This study indicated that the number of outcome events is less than 1 per 3000 person years. This study in more than 45 000 Dutch statin users suggests that rosuvastatin does not lead to an increased incidence of rhabdomyolysis, myopathy, acute renal failure or hepatic impairment compared to other statins. Copyright © 2006 John Wiley & Sons, Ltd.
Solution self‐assembly of tailor‐made macromolecular building blocks prepared by controlled radical polymerization techniques
Authors: Lutz Jean‐François
Published: June 2006

This review describes the preparation of colloidal aggregates (spherical micelles, cylindrical micelles, polymer vesicles, multicompartment micelles, polyion complexes, schizophrenic micelles) using bottom‐up self‐assembly approaches. In particular, it focuses primarily on the self‐organization of well‐defined macromolecular building blocks (macrosurfactants, polysoaps, polyelectrolytes) synthesized by controlled radical polymerization techniques such as atom transfer radical polymerization, reversible addition fragmentation transfer polymerization and nitroxide‐mediated polymerization. The goal of this review is to highlight that these versatile techniques of polymer synthesis allow the preparation of unprecedented nanostructures in dilute solutions. Copyright © 2006 Society of Chemical Industry
On the Mathematical Reconstruction of Two Dimensional Plants
Authors: Grzywna Zbigniew J. , Borys Przemysław , Dudek Gabriela
Published: June 2006

A set of 10, chosen medicinal plants (some of them with a reputation as remedies for tuberculosis) has been investigated through Partitioned Iterated Function Systems-Semi Fractals with Angle (PIFS-SFA) coding, Lempel, Ziv, Welch with quantization and noise (LZW-QN) compression, and surface density statistics (f(α)-SDS) discrimination techniques. The final outcomes of this quantitative analysis were, firstly: the linear ordering of the plants in question accompanied by the hope that it reflects their medical significance, secondly: the mathematical representation of each of the plants, and thirdly: the impressive compression achieved, leading to remarkable computer memory saving, and still permitting successful pattern recognition i.e., proper identification of the plant from the compressed image.
WOMEN’S EDUCATIONAL ATTAINMENT AND INTERGENERATIONAL PATTERNS OF FERTILITY BEHAVIOUR IN KENYA
Authors: OMARIBA D. WALTER RASUGU
Published: June 2006

There is a strong theoretical and empirical relationship between educational attainment and fertility behaviour. However, a fundamental issue that has largely been neglected is the change in this relationship across cohorts resulting from differential improvement in educational opportunities for women over time and how it relates to fertility transition. Utilizing the 1998 DHS data from Kenya this study examines the differential effect of educational attainment on women’s use of modern contraception and desire for cessation of childbearing across generations. The findings indicate that even after controlling for husband’s education and other relevant factors, a woman’s advanced education is positively associated with use of modern contraception. However, support for a similar hypothesis on a woman’s desire for family limitation was only found among the youngest cohort of women. The results suggest that for Kenya’s incipient fertility transition to be sustained the government needs to continue efforts to improve female education and support access to family planning among younger women.
Faith, doubt, aid and prayer: the Lisbon earthquake of 1755 revisited
Authors: BASSNETT SUSAN
Published: June 2006

This essay considers reactions to the Lisbon earthquake of 1755, in particular the ways in which the founders of English Methodism, John and Charles Wesley used the event in their sermons and hymns respectively. The Wesleys focused on the vengeful power of the divine in order to urge people to look into their hearts and change their ways to avoid damnation. In contrast, the reaction to the global natural disasters of 2005 has been quite different. The Archbishop of Canterbury's essay that emphasises the privacy of faith that exists because it is engaged in a struggle against doubt is compared with the Wesleyan response, and through these very different religious positions the contrast between eighteenth century and twenty-first century reactions to natural disasters is highlighted.
Seeing too much: the 1755 earthquake in literature
Authors: CARVALHÃO BUESCO HELENA
Published: June 2006

The 1755 Lisbon earthquake produced huge and diversified reactions in Portuguese literature. This paper aims at analysing some of the issues raised by these reactions, namely: the recognition of the disturbance, beginning as geographical and architectural, but soon becoming symbolic and anthropological; the effects on the understanding of a phenomenon which, because it goes beyond the frontiers of what is known, soon becomes a paradigm of the incomprehensible, with the consequent debates on how to make God compatible with the destruction that occurred, and the confirmation of fear and terror as the major effects of the event. The paradoxical relation between seeing (too much) and saying (too little) is stressed, as well as the visual, theatrical, and melodramatic components of several descriptions of the event.
German historians and the crucial dilemma
Authors: VON DER DUNK HERMANN W.
Published: June 2006

Post-war German historiography is an interesting example of changing norms and the problem of satisfying a balance between explanation and (moral) judgement. Whereas national historians of Imperial Germany could feel in harmony with History, defeat and the peace of Versailles destroyed the belief in historical justice, so the bulk of the craft sympathized with Hitler's policy, although not always with his methods. The fall of the Third Reich and the revelation of its crimes caused a deep crisis of historical consciousness and attempts to deny or belittle personal responsibility and cooperation. After the 1960s however, a generation took over who could internalize the democratic norms and, through that, closed the gap between German and Western historiography. With the next generation after the reunification, critical revisionism of the national past even increased in so far as it included the first wave of post-war historiography with its apologetic tendencies. Historiography so became a striking example of a thorough national metamorphosis.
Paleointensity applications to timing and extent of eruptive activity, 9°–10°N East Pacific Rise
Authors: Bowles Julie , Gee Jeffrey S. , Kent Dennis V. , Perfit Michael R. , Soule S. Adam , Fornari Daniel J.
Published: June 2006

Placing accurate age constraints on near‐axis lava flows has become increasingly important given the structural and volcanic complexity of the neovolcanic zone at fast spreading ridges. Geomagnetic paleointensity of submarine basaltic glass (SBG) holds promise for placing quantitative age constraints on near‐axis flows. In one of the first extensive tests of paleointensity as a dating tool or temporal marker we present the results of over 550 successful SBG paleointensity estimates from 189 near‐axis (<4 km) sites at the East Pacific Rise, 9°–10°N. Paleointensities range from 6 to 53 μT and spatially correspond to the pattern expected from known temporal variations in the geomagnetic field. Samples within and adjacent to the axial summit trough (AST) have values approximately equal to or slightly higher than the present‐day. Samples out to 1–3 km from the AST have values higher than the present‐day, and samples farther off axis have values lower than the present‐day. The on‐axis samples (<500 m from the AST) provide a test case for using models of paleofield variation for the past few hundred years as an absolute dating technique. Results from samples collected near a well‐documented eruption in 1991–1992 suggest there may be a small negative bias in the paleointensity estimates, limiting resolution of the dating technique. Possible explanations for such a bias include local field anomalies produced by preexisting magnetic terrain; anomalously high magnetic unblocking temperatures, leading to a small cooling rate bias; and/or the possibility of a chemical remanence produced by in situ alteration of samples likely to have complicated thermal histories. Paleointensity remains useful in approximating age differences in young flows, and a clear along‐axis paleointensity contrast near 9°50′N is suggestive of a ∼150–200 year age difference. Paleointensity values of off‐axis samples are generally consistent with rough age interpretations based on side scan data. Furthermore, spatial patterns in the paleointensity suggest extensive off‐axis flow emplacement may occur infrequently, with recurrence intervals of 10–20 kyr. Results of a stochastic model of lava emplacement show that this can be achieved with a single distribution of flows, with flow size linked to time between eruptions.
Ray trace calculation of ionospheric propagation at lower frequencies
Authors: Reilly Michael H.
Published: June 2006

The Raytrace/Ionospheric Conductivity and Electron Density–Bent‐Gallagher model has been revised to make it applicable to ionospheric propagation at low radio frequencies (0.5–5.0 MHz), where the ionosphere and magnetic anisotropy drastically alter propagation paths and provide a severe test of propagation model algorithms. The necessary revisions are discussed, and the model is applied to the problem of ionospheric penetration from a source below the ionosphere to a receiver above the ionosphere. It is necessary to include the electron collision frequency in the Appleton‐Hartree index of refraction in order to permit ionospheric penetration for radio frequencies below the maximum plasma frequency (e.g., whistler modes). The associated reformulation of the ray trace equations for a complex index of refraction is straightforward. Difficulties with numerical methods are cited for the lowest frequencies, and future improvements are indicated.
Interlaced x-ray microplanar beams: A radiosurgery approach with clinical potential
Authors: Dilmanian F. Avraham , Zhong Zhong , Bacarian Tigran , Benveniste Helene , Romanelli Pantaleo , Wang Ruiliang , Welwart Jeremy , Yuasa Tetsuya , Rosen Eliot M. , Anschel David J.
Published: June 2006

Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-μm thick and spaced 100–300 μm on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90° angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 × 3.4 × 3.4 mm3exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-μm dose falloff (80–20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.
The pink shrimp Farfantepenaeus duorarum, its symbionts and helminths as bioindicators of chemical pollution in Campeche Sound, Mexico
Authors: Vidal-Martínez V.M. , Aguirre-Macedo M.L. , Del Rio-Rodríguez R. , Gold-Bouchot G. , Rendón-von Osten J. , Miranda-Rosas G.A.
Published: June 2006

The pink shrimp Farfantepenaeus duorarum may acquire pollutants, helminths and symbionts from their environment. Statistical associations were studied between the symbionts and helminths of F. duorarum and pollutants in sediments, water and shrimps in Campeche Sound, Mexico. The study area spatially overlapped between offshore oil platforms and natural shrimp mating grounds. Spatial autocorrelation of data was controlled with spatial analysis using distance indices (SADIE) which identifies parasite or pollutant patches (high levels) and gaps (low levels), expressing them as clustering indices compared at each point to produce a measure of spatial association. Symbionts included the peritrich ciliates Epistylis sp. and Zoothamnium penaei and all symbionts were pooled. Helminths included Hysterothylacium sp., Opecoeloides fimbriatus, Prochristianella penaei and an unidentified cestode. Thirty-five pollutants were identified, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides and heavy metals. The PAHs (2–3 ring) in water, unresolved complex mixture (UCM), Ni and V in sediments, and Zn, Cr and heptachlor in shrimps were significantly clustered. The remaining pollutants were randomly distributed in the study area. Juvenile shrimps acquired pesticides, PAHs (2–3 rings) and Zn, while adults acquired PAHs (4–5 rings), Cu and V. Results suggest natural PAH spillovers, and continental runoff of dichlorodiphenyltrichloroethane (DDT), PCBs and PAHs (2–3 ring). There were no significant associations between pollutants and helminths. However, there were significant negative associations of pesticides, UCM and PCBs with symbiont numbers after controlling shrimp size and spatial autocorrelation. Shrimps and their symbionts appear to be promising bioindicators of organic chemical pollution in Campeche Sound.
BLOC-1 Complex Deficiency Alters the Targeting of Adaptor Protein Complex-3 Cargoes
Authors: Salazar G. , Craige B. , Styers M. L. , Newell-Litwa K. A. , Doucette M. M. , Wainer B. H. , Falcon-Perez J. M. , Dell’Angelica E. C. , Peden A. A. , Werner E. , Faundez V.
Published: June 2006

Mutational analyses have revealed many genes that are required for proper biogenesis of lysosomes and lysosome-related organelles. The proteins encoded by these genes assemble into five distinct complexes (AP-3, BLOC-1-3, and HOPS) that either sort membrane proteins or interact with SNAREs. Several of these seemingly distinct complexes cause similar phenotypic defects when they are rendered defective by mutation, but the underlying cellular mechanism is not understood. Here, we show that the BLOC-1 complex resides on microvesicles that also contain AP-3 subunits and membrane proteins that are known AP-3 cargoes. Mouse mutants that cause BLOC-1 or AP-3 deficiencies affected the targeting of LAMP1, phosphatidylinositol-4-kinase type II alpha, and VAMP7-TI. VAMP7-TI is an R-SNARE involved in vesicle fusion with late endosomes/lysosomes, and its cellular levels were selectively decreased in cells that were either AP-3- or BLOC-1–deficient. Furthermore, BLOC-1 deficiency selectively altered the subcellular distribution of VAMP7-TI cognate SNAREs. These results indicate that the BLOC-1 and AP-3 protein complexes affect the targeting of SNARE and non-SNARE AP-3 cargoes and suggest a function of the BLOC-1 complex in membrane protein sorting.
Simulation and the design building block approach in the design of ships and other complex systems
Authors: Andrews D.J
Published: June 2006

This paper is in many respects a continuation of the earlier paper by the author published in Proc. R. Soc. A in 1998 entitled ‘A comprehensive methodology for the design of ships (and other complex systems)’. The earlier paper described the approach to the initial design of ships developed by the author during some 35 years of design practice, including two previous secondments to teach ship design at UCL. The present paper not only takes that development forward, it also explains how the research tool demonstrating the author's approach to initial ship design has now been incorporated in an industry based design system to provide a working graphically and numerically integrated design system. This achievement is exemplified by a series of practical design investigations, undertaken by the UCL Design Research Centre led by the author, which were mainly undertaken for industry clients in order to investigate real problems to which the approach has brought significant insights. The other new strand in the present paper is the emphasis on the human factors or large scale ergonomics dimension, vital to complex and large scale design products but rarely hitherto been given sufficient prominence in the crucial formative stages of large scale design because of the inherent difficulties in doing so. The UCL Design Building Block approach has now been incorporated in the established PARAMARINE ship design system through a module entitled SURFCON. Work is now underway on an Engineering and Physical Sciences Research Council joint project with the University of Greenwich to interface the latter's escape simulation tool maritimeEXODUS with SURFCON to provide initial design guidance to ship designers on personnel movement. The paper's concluding section considers the wider applicability of the integration of simulation during initial design with the graphically driven synthesis to other complex and large scale design tasks. The paper concludes by suggesting how such an approach to complex design can contribute to the teaching of designers and, moreover, how this design approach can enable a creative qualitative approach to engineering design to be sustained despite the risk that advances in computer based methods might encourage emphasis being accorded to solely to quantitative analysis.
The distribution of species diversity across a flora's component lineages: dating the Cape's ‘relicts’
Authors: Warren Ben H , Hawkins Julie A
Published: June 2006

The Cape Floristic Region is exceptionally species-rich both for its area and latitude, and this diversity is highly unevenly distributed among genera. The modern flora is hypothesized to result largely from recent (post-Oligocene) speciation, and it has long been speculated that particular species-poor lineages pre-date this burst of speciation. Here, we employ molecular phylogenetic data in combination with fossil calibrations to estimate the minimum duration of Cape occupation by 14 unrelated putative relicts. Estimates vary widely between lineages (7–101 Myr ago), and when compared with the estimated timing of onset of the modern flora's radiation, it is clear that many, but possibly not all, of these lineages pre-date its establishment. Statistical comparisons of diversities with lineage age show that low species diversity of many of the putative relicts results from a lower rate of diversification than in dated Cape radiations. In other putative relicts, however, we cannot reject the possibility that they diversify at the same underlying rate as the radiations, but have been present in the Cape for insufficient time to accumulate higher diversity. Although the extremes in diversity of currently dated Cape lineages fall outside expectations under a constant underlying diversification rate, sampling of all Cape lineages would be required to reject this null hypothesis.
Identification of clustered YY1 binding sites in imprinting control regions
Authors: Do Kim Jeong , Hinz Angela K. , Bergmann Anne , Huang Jennifer M. , Ovcharenko Ivan , Stubbs Lisa , Kim Joomyeong
Published: June 2006

Mammalian genomic imprinting is regulated by imprinting control regions (ICRs) that are usually associated with tandem arrays of transcription factor binding sites. In this study, the sequence features derived from a tandem array of YY1 binding sites of Peg3-DMR (differentially methylated region) led us to identify three additional clustered YY1 binding sites, which are also localized within the DMRs of Xist, Tsix, and Nespas. These regions have been shown to play a critical role as ICRs for the regulation of surrounding genes. These ICRs have maintained a tandem array of YY1 binding sites during mammalian evolution. The in vivo binding of YY1 to these regions is allele specific and only to the unmethylated active alleles. Promoter/enhancer assays suggest that a tandem array of YY1 binding sites function as a potential orientation-dependent enhancer. Insulator assays revealed that the enhancer-blocking activity is detected only in the YY1 binding sites of Peg3-DMR but not in the YY1 binding sites of other DMRs. Overall, our identification of three additional clustered YY1 binding sites in imprinted domains suggests a significant role for YY1 in mammalian genomic imprinting.
Serum ghrelin levels are suppressed in hypopituitary patients following insulin‐induced hypoglycaemia irrespective of GH status
Authors: Ryber Louise , Öbrink Kristina , Houe Nanna , Frystyk Jan , Jørgensen Jens Otto Lunde
Published: June 2006

Objective  Circulating ghrelin is suppressed during insulin‐induced hypoglycaemia in healthy subjects, but it is unknown whether this is determined by feedback inhibition from counter‐regulatory hormones. We therefore investigated the impact of GH and cortisol on ghrelin secretion during insulin‐induced hypoglycaemia.

Design  Serum levels of ghrelin, GH, and cortisol were measured in 41 adult patients with suspected hypopituitarism during insulin‐induced hypoglycaemia. Based on their peak GH response (cut‐off level: 3 µg/l), the patients were divided into a GH‐sufficient group (GHS) and a GH‐deficient group (GHD).

Results  The GHS patients (n = 16) were younger (P < 0·01), had lower baseline cortisol levels [255 ± 37 vs. 372 ± 38 nmol/l (P = 0·04)], and tended to have a lower body mass index (P = 0·09) as compared to GHD patients (n = 25). By definition, peak GH (µg/l) was higher in GHS patients [15·0 ± 1·8 vs. 1·0 ± 0·2 (P < 0·0001)].The increase in serum cortisol during the ITT (insulin‐tolerance test) was higher and occurred later in GHS patients [Cmax (nmol/l): 561 ± 41 vs. 412 ± 50 (P = 0·04); Tmax (minutes): 65 ± 5 vs. 49 ± 5 (P = 0·03)]. Serum ghrelin levels changed significantly with time during ITT in both groups (P < 0·0001), characterized by a moderate decline during the initial 50–60 min and a return to baseline after 2 h. No significant differences were recorded in AUCghrelin during the ITT between the two groups. No gender differences in ghrelin levels were recorded.

Conclusions  (i) Like in healthy subjects serum ghrelin levels are suppressed during an ITT in patients with suspected hypopituitarism. (ii) The suppression of ghrelin was similar in GHD and GHS subjects and was not determined by cortisol. (iii) We hypothesize that insulin rather than hypoglycaemia accounts for ghrelin suppression during an ITT.
Synergistic effects associated with climate change and the development of rocky shore molluscs
Authors: Przeslawski R. , Davis A. R. , Benkendorff K.
Published: June 2006

Global climate change and ozone layer thinning will simultaneously expose organisms to increasingly stressful conditions. Early life stages of marine organisms, particularly eggs and larvae, are considered most vulnerable to environmental extremes. Here, we exposed encapsulated embryos of three common rocky shore gastropods to simultaneous combinations of ecologically realistic levels of ultraviolet radiation (UVR), water temperature stress and salinity stress to identify potential interactions and associated impacts of climate change. We detected synergistic effects with increases in mortality and retardation in development associated with the most physiologically stressful conditions. The effects of UVR were particularly marked, with mortality increasing up to 12‐fold under stressful conditions. Importantly, the complex outcomes observed on applying multiple stressors could not have been predicted from examining environmental variables in isolation. Hence, we are probably dramatically underestimating the ecological impacts of climate change by failing to consider the complex interplay of combinations of environmental variables with organisms.
Fire history and the global carbon budget: a 1°× 1° fire history reconstruction for the 20th century
Authors: Mouillot Florent , Field Christopher B.
Published: June 2006

A yearly global fire history is a prerequisite for quantifying the contribution of previous fires to the past and present global carbon budget. Vegetation fires can have both direct (combustion) and long‐term indirect effects on the carbon cycle. Every fire influences the ecosystem carbon budget for many years, as a consequence of internal reorganization, decomposition of dead biomass, and regrowth. We used a two‐step process to estimate these effects. First we synthesized the available data available for the 1980s or 1990s to produce a global fire map. For regions with no data, we developed estimates based on vegetation type and history. Second, we then worked backwards to reconstruct the fire history. This reconstruction was based on published data when available. Where it was not, we extrapolated from land use practices, qualitative reports and local studies, such as tree ring analysis. The resulting product is intended as a first approximation for questions about consequences of historical changes in fire for the global carbon budget. We estimate that an average of 608 Mha yr−1burned (not including agricultural fires) at the end of the 20th century. 86% of this occurred in tropical savannas. Fires in forests with higher carbon stocks consumed 70.7 Mha yr−1at the beginning of the century, mostly in the boreal and temperate forests of the Northern Hemisphere. This decreased to 15.2 Mha yr−1in the 1960s as a consequence of fire suppression policies and the development of efficient fire fighting equipment. Since then, fires in temperate and boreal forests have decreased to 11.2 Mha yr−1. At the same time, burned areas increased exponentially in tropical forests, reaching 54 Mha yr−1in the 1990s, reflecting the use of fire in deforestation for expansion of agriculture. There is some evidence for an increase in area burned in temperate and boreal forests in the closing years of the 20th century.
Foliar respiration acclimation to temperature and temperature variableQ10alter ecosystem carbon balance
Authors: Wythers Kirk R. , Reich Peter B. , Tjoelker Mark G. , Bolstad Paul B.
Published: June 2006

The response of respiration to temperature in plants can be considered at both short‐ and long‐term temporal scales. Short‐term temperature responses are not well described by a constantQ10of respiration, and longer‐term responses often include acclimation. Despite this, many carbon balance models use a staticQ10of respiration to describe the short‐term temperature response and ignore temperature acclimation.

We replaced static respiration parameters in the ecosystem model photosynthesis and evapo‐transpiration (PnET) with a temperature‐driven basal respiration algorithm (Rdacclim) that accounts for temperature acclimation, and a temperature‐variableQ10algorithm (Q10var). We ran PnET with the new algorithms individually and in combination for 5 years across a range of sites and vegetation types in order to examine the new algorithms' effects on modeled rates of mass‐ and area‐based foliar dark respiration, above ground net primary production (ANPP), and foliar respiration–photosynthesis ratios.

TheRdacclimalgorithm adjusted dark respiration downwards at temperatures above 18°C, and adjusted rates up at temperatures below 5°C. TheQ10varalgorithm adjusted dark respiration down at temperatures below 15°C. Using both algorithms simultaneously resulted in decreases in predicted annual foliar respiration that ranged from 31% at a tall‐grass prairie site to 41% at a boreal coniferous site. The use of theRdacclimandQ10varalgorithms resulted in increases in predicted ANPP ranging from 18% at the tall‐grass prairie site to 38% at a warm temperate hardwood forest site.

The new foliar respiration algorithms resulted in substantial and variable effects on PnETs predicted estimates of C exchange and production in plants and ecosystems. Current models that use static parameters may over‐predict respiration and subsequently under‐predict and/or inappropriately allocate productivity estimates. Incorporating acclimation of basal respiration and temperature‐sensitiveQ10have the potential to enhance the application of ecosystem models across broad spatial scales, or in climate change scenarios, where large temperature ranges may cause static respiration parameters to yield misleading results.
Role of peroxisome proliferator‐activated receptor‐α in acute pancreatitis induced by cerulein
Authors: Genovese Tiziana , Mazzon Emanuela , Di Paola Rosanna , Muià Carmelo , Crisafulli Concetta , Malleo Giuseppe , Esposito Emanuela , Cuzzocrea Salvatore
Published: June 2006

The peroxisome proliferator‐activated receptor‐α (PPAR‐α) is a member of the nuclear receptor superfamily of ligand‐dependent transcription factors related to retinoid, steroid and thyroid hormone receptors. The aim of the present study was to examine the effects of endogenous PPAR‐α ligand on the development of acute pancreatitis caused by cerulein in mice. Intraperitoneal injection of cerulein into PPAR‐α wild‐type (WT) mice resulted in severe, acute pancreatitis characterized by oedema, neutrophil infiltration and necrosis and by elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as an increase in myeloperoxidase activity) was associated with enhanced expression of the adhesion molecules intercellular adhesion molecule‐1 (ICAM‐1) and P‐selectin. Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for transforming growth factor‐β (TGF‐β) and vascular endothelial growth factor (VEGF) in the pancreas of cerulein‐treated PPAR‐α wild‐type (WT) mice in comparison to sham‐treated mice. Acute pancreatitis in PPAR‐αWT mice was also associated with a significant mortality (20% survival at 5 days after cerulein administration). In contrast, the degree of pancreatic inflammation and tissue injury (histological score), up‐regulation/formation of ICAM‐1 and P‐selectin, infiltration of neutrophils, and the expression of TGF‐β and VEGF was markedly enhanced in pancreatic tissue obtained from cerulein‐treated PPAR‐α knockout (KO) mice. Thus, endogenous PPAR‐α ligands reduce the degree of pancreas injury caused by acute pancreatitis induced by cerulein administration.
Patient self‐medication – a change in hospital practice
Authors: Grantham Glennice , McMillan Virginia , Dunn Sandra V , Gassner Lee‐Anne , Woodcock Peta
Published: June 2006

Aims and objectives.  The purpose of this study was to evaluate the effectiveness of a self‐medication programme (SMP) for inpatients of the Nursing Convalescent Unit, a 26‐bed unit with medical and surgical patients.

Background.  Self‐medication is an important part of self‐management of chronic illness. Self‐medication is a way of allowing patients to give themselves their medications in hospital after receiving education instead of the usual practice of medications administered by a Registered Nurse (RN).

Design.  The pilot study was undertaken over a six‐month period to examine the relationship between a programme of self‐medication and patient knowledge and adherence to medication regimens, number of medication errors, efficiency in relation to the number of nursing hours associated with the SMP, patient and nursing satisfaction.

Methods.  A total of 220 patients participated in the study. The SMP included three levels of patient self‐administration of medications: level one, medications administered by a RN; level two, self‐medication directly supervised by a RN and level three, self‐medication indirectly supervised by a RN. Outcome measures included staff and patient satisfaction, number of medication errors, time taken by nurses to undertake activities related to the SMP and the number of patients who achieved levels two and three.

Results.  Study findings showed that 45% of patients remained on level one, 26% achieved level two and 29% achieved level three. There were no patient initiated medication errors during the study period. Efficiencies were identified in staff workload associated with patient discharge procedures. Overall, nurses perceived that the SMP increased their knowledge of medications and contributed to effective patient education.

Conclusions.  In selected patients, the SMP was an effective aid for improving adherence to medication regimens.

Relevance to clinical practice.  Collaboration between nurses, medical staff, pharmacists, patients and carers is integral to the success of in hospital SMP.
Practice development ‘without walls’ and the quandary of corporate practice
Authors: Graham Iain , Fielding Carol , Rooke Debbie , Keen Steven
Published: June 2006

Aim.  The context of this study is a group of clinical nurse specialists from across a Trust seeking accreditation as a practice development unit. The university was asked to facilitate the accreditation process via 11 2‐hour learning sessions (including a one‐hour focus group). During initial discussions between the university and practice development unit, the overarching research question for this study was set as: ‘what are the main roles and responsibilities of clinical nurse specialists?’

Background.  Although there is no known study of a practice development unit based beyond a ward or speciality, the central tenet of the practice development unit literature is that units must demonstrate their worth if they are to survive and harness senior management support in doing so.

Design and methods.  Data gleaned from the transcribed audio tape‐recordings of the learning sessions were studied at least three times to ensure transcription accuracy and produce detailed charts. Ethical approval was granted by the appropriate Local Research Ethics Committee and written informed consent obtained from clinical nurse specialists. The study lasted 30 months and ended in October 2004.

Results.  The four crucial statements that give meaning to specialist practice are: quality care giver; expert; information giver and initiator of change. Further analysis reveals the area of corporate and political practice as being missing from this and other lists of clinical nurse specialist attributes found in the literature. Clinical nurse specialists characterize their relationship with the Trust in terms of dichotomy – differing agendas and perceptions of value.

Conclusions.  The specialist role requires professional development in the areas of corporate and political acumen and professional business management.

Relevance to clinical practice.  While the findings of this study relate to one Trust and a group of 16 clinical nurse specialists, with careful application they may be transferable to other settings and groups of senior nurses.
Use of trade‐off theory to advance understanding of herbivore–parasite interactions
Authors: HUTCHINGS MICHAEL R. , JUDGE JOHANNA , GORDON IAIN J. , ATHANASIADOU SPIRIDOULA , KYRIAZAKIS ILIAS
Published: June 2006

Trade‐off theory has been extensively used to further our understanding of animal behaviour. In mammalian herbivores, it has been used to advance our understanding of their reproductive, parental care and foraging strategies. Here, we detail how trade‐off theory can be applied to herbivore–parasite interactions, especially in foraging environments.

Foraging is a common mode of uptake of parasites that represent the most pervasive challenge to mammalian fitness and survival. Hosts are hypothesized to alter their foraging behaviour in the presence of parasites in three ways: (i) hosts avoid foraging in areas that are contaminated with parasites; (ii) hosts select diets that increase their resistance and resilience to parasites; and (iii) hosts select for foods with direct anti‐parasitic properties (self‐medication). We concentrate on the mammalian herbivore literature to detail the recent advances made using trade‐off frameworks to understand the mechanisms behind host–parasite interactions in relation to these three hypotheses.

In natural systems, animals often face complex foraging decisions including nutrient intake vs. predation risk, nutrient intake vs. sheltering and nutrient intake vs. parasite risk trade‐offs. A trade‐off framework is detailed that can be used to interpret mammal behaviour in complex environments, and may be used to advance the self‐medication hypothesis.

The use of trade‐off theory has advanced our understanding of the contact process between grazing mammalian hosts and their parasites transmitted via the faecal–oral route. Experimental manipulation of the costs and benefits of a nutrient intake vs. parasite risk trade‐off has shown that environmental conditions (forage quality and quantity) and the physiological state (parasitic and immune status) of a mammalian host can both affect the behavioural decisions of foraging animals.

Naturally occurring trade‐offs and the potential to manipulate their costs and benefits enables us to identify the abilities and behavioural rules used by mammals when making decisions in complex environments and thus predict animal behaviour.
Gray whaleEschrichtius robustuspopulation and stock identity
Authors: SWARTZ STEVEN L. , TAYLOR BARBARA L. , RUGH DAVID J.
Published: June 2006

In response to conservation and management concerns about gray whaleEschrichtius robustuspopulation and stock structure, we provide an overview of the life history and ecology of gray whales as a context for discussion of population and stock structure within the species. Historically eastern and western North Pacific gray whales were managed separately because: (i) their ranges do not overlap; (ii) genetic analyses indicate that the two populations are significantly different; and (iii) eastern gray whales have increased in abundance over the past century while western gray whales have not.

Here, we review gray whale migration timing and segregation, feeding and prey species, and reproduction and reproductive behaviour. For the eastern and western gray whale, we review their distribution, history of exploitation, abundance and current status, although most of what is known is founded on the better studied eastern gray whale and only implied for the lesser known western gray whale. Methods to investigate population and stock identity are reviewed including genetics, morphology, chemical signatures, carbon isotopes, parasites, photographic identification and trends in abundance.

While the evidence indicates that there is at least some degree of mixing within each of the gray whale populations, no stocks or sub‐stocks can be defined. Population structure is not evident in nuclear data, and because selection occurs primarily on the nuclear genome, it is unlikely that there is structuring within each population that could result in evolutionary differences. For western gray whales, there are insufficient data to assess the plausibility of stock structure within the population, owing to its extremely depleted state. Research on eastern gray whales has focused mostly on documenting changes in abundance, feeding biology and behaviour, and suggests separate breeding groups to be unlikely. Both males and females are promiscuous breeders lending little opportunity for the nuclear genome to be anything other than well mixed as is suggested by the high haplotypic diversity of the eastern population.

The available data strongly indicate that western gray whales represent a population geographically isolated from eastern gray whales and therefore that the western and eastern populations should be treated as separate management units.
Challenges to re‐enrolling perinatally HIV‐infected and HIV‐exposed but uninfected children into a prospective cohort study: strategies for locating and recruiting hard‐to‐reach families
Authors: Freedman Darcy , Koenig Linda J. , Wiener Jeffrey , Abrams Elaine J. , Carter Rosalind J. , Tepper Vicki , Palumbo Paul , Nesheim Steven , Bulterys Marc
Published: June 2006

Children infected with the human immunodeficiency virus (HIV) are living longer. Studies aimed at understanding the health and well‐being of these children as they age into adolescence are enhanced by research designs that include appropriate comparison groups. HIV‐exposed but uninfected children are one such comparison group; however, recruitment of this comparison group is challenging because uninfected children may no longer be followed at tertiary care centres, and some may be in foster care or no longer living with their biological parents. This paper describes the recruitment methods, sampling plan, and factors associated with enrolling perinatally HIV‐infected children and a comparison group of HIV‐exposed but uninfected children into the HIV Follow‐up Of Perinatally Exposed Children (PACTS‐HOPE) prospective cohort study. The source population consists of HIV‐infected and uninfected children originally enrolled in the Perinatal AIDS Collaborative Transmission Study (PACTS). Recruitment took place at paediatric HIV clinics in four US locations between March 2001 and March 2003.

A total of 182 HIV‐infected and 180 uninfected children were enrolled. Enrolment of uninfected children was much harder than that of infected children because the former often could not be located. After adjusting for site and birth‐year category, uninfected children born to white mothers were significantly less likely to be enrolled (P < 0.01). There was a trend for infected and uninfected children of mothers with a history of injection drug use to enrol at lower rates. Although recruitment of the uninfected comparison group was challenging, it was nevertheless facilitated by hierarchical recruitment techniques, involvement of family networks, and continuity of study staff. The PACTS‐HOPE cohort will provide opportunities for future research aimed at understanding the unique effects of HIV on the well‐being of HIV‐infected children.
Differences in construction costs and chemical composition between deciduous and evergreen woody species are small as compared to differences among families
Authors: VILLAR RAFAEL , ROBLETO JEANNETTE RUIZ , DE JONG YVONNE , POORTER HENDRIK
Published: June 2006

We tested to what extent differences in construction costs (CC) and chemical composition of woody species are attributed to leaf habit. Eight evergreen and eight deciduous species belonging to six families were selected to form eight phylogenetic independent contrasts (PICs). The plants were grown from seed in a glasshouse. Differences in leaf, stem and root CC between evergreen and deciduous species were minor, the proportion of variance explained by leaf habit generally being less than 6%. Surprisingly, differences in leaf chemical composition between deciduous and evergreen species were small as well. Variation in CC and chemical composition among families was substantial, the factor ‘family’ explaining 50–85% of variance. We therefore conclude that in this case, phylogeny is a more important factor than functional group. Leaves of the fast‐growing species in this experiment showed high levels of minerals, organic acids, proteins and lipids, whereas leaves of the slow‐growing species had higher concentrations of soluble phenolics, lignin as well as higher carbon/nitrogen (C/N) ratio. These relationships suggest a trade‐off between growth and defence. In contrast, CC of leaves, stems, roots or whole plants showed no or only a weak correlation with relative growth rate (RGR). The C/N ratio of the leaves is an easily measured parameter that correlated strongly in a negative way with the RGR of the plants and reflected better the balance between investment in structure and physiological functioning than CC.