bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stock, turnover time and accumulation of organic matter in bulk and density fractions of a Podzol soil
Authors: Schulze K. , Borken W. , Muhr J. , Matzner E. 
Published: June 2009

SummaryTemperate forest soils store large amounts of organic matter and are considered as net sinks for atmospheric carbon dioxide. Information about the sink strength and the turnover time of soil organic carbon (SOC) is required to assess the potential response of soils to climate change. Here we report on stocks, turnover times (TT) and accumulation of SOC in bulk soil and density fractions from genetic horizons of a Podzol in the Fichtelgebirge, Germany. Stocks of SOC, total nitrogen and exchangeable cations determined in nine quantitative soil pits strongly varied with stone content and thickness of horizons in both the organic layer and the mineral soil. On the basis of radiocarbon signatures, mean turnover times of 4, 9 and 133 years, respectively, were calculated for Oi, Oe and Oa horizons from three soil pits, using a non‐steady‐state model. The Oa horizons accumulated 4–8 g C m−2 year−1 whereas the Oi and Oe horizons were close to steady‐state during the past decade. Free particulate organic matter (FPOM) was the most abundant fraction in the Oa and EA horizons with TT of 70–480 years. In the B horizons, mineral associated organic matter (MAOM) dominated with over 40% of total SOC and had TT of 390–2170 years. In contrast to other horizons, MAOM in the Bsh and Bs horizon had generally faster TT than occluded particulate organic matter (OPOM), possibly because of sorption of dissolved organic carbon by iron and aluminium oxides/hydroxides. Our results suggest that organic horizons with relatively short turnover times could be particularly vulnerable to changes in climate or other disturbances.
Disturbance and species displacement: different tolerances to stream drying and desiccation in a native and an invasive crayfish
Authors: LARSON ERIC R. , MAGOULICK DANIEL D. , TURNER CLINTON , LAYCOCK KELLY H. 
Published: June 2009

Summary1. Crayfish are among the most threatened taxa in the world and invasive crayfish are the primary cause of the decline of native crayfish. Most research has emphasised biotic interactions as the mechanism by which native crayfish are displaced by invasives, although crayfish occupy variable environments and the role of disturbance in facilitating crayfish invasion and displacement is understudied.2. We compared tolerance to a disturbance, stream drying, in a native and invasive crayfish as a potential mechanism to explain their distribution. Our experiments and observations were conducted across scales, from laboratory environmental chambers to stream mesocosms to field sampling. We hypothesised that the invasive crayfish would be more tolerant of desiccation than the native, and that this physiological distinction between the two would be reflected in their distribution in relation to stream drying.3. In the laboratory, the native crayfishOrconectes eupunctuswas less tolerant of desiccation than the invasiveOrconectes neglectus chaenodactylus, with all native crayfish dying within 2 days without water, while some of the invasive crayfish survived for nearly 2 weeks. Under simulated stream drying in mesocosms, only the nativeO. eupunctussurvived less well than in a control. Field sampling demonstrated a significant negative relationship betweenO. eupunctusdensity and low summer flows, whileO. neglectusdensity was positively associated with low summer flows. The greater resistance ofO. neglectusto drying could, through priority effects, inhibit recolonisation byO. eupunctusonce flow resumes.4. Abiotic disturbances are potentially important to the displacement of native by invasive crayfish. Disturbance mediated displacement of aquatic species provides both an opportunity to conserve native species by maintaining or restoring habitat and disturbance regimes and is also a challenge due to increasing human water demand, flow regime alteration and global climate change.
Diabetic persons with foot ulcers and their perceptions of hyperbaric oxygen chamber therapy
Authors: Katarina Hjelm , Magnus Löndahl , Per Katzman , Jan Apelqvist 
Published: June 2009

Aim.  To elucidate how diabetic patients with limb‐threatening foot lesions perceive and evaluate content and organisation of treatment in a multi‐place hyperbaric oxygen chamber.Background.  To our knowledge there are no patients’ evaluations of diabetes care in a high‐technology area like the hyperbaric oxygen chamber. The burden on persons with diabetic foot complications might be increased if adjuvant therapy with hyperbaric oxygen therapy (HBOT) within a locked airtight vessel is given.Design.  Explorative study.Participants.  Participants were included in the HODFU study, a prospective randomised double‐blind study, designed to evaluate whether HBOT heals more chronic foot ulcers than placebo treatment with hyperbaric air. Six females and 13 males, aged 44–83 years (median 70), with diabetic foot ulcers, participated.Method.  Focus‐group interviews by an external evaluator.Results.  Management was perceived as well‐functioning with competent staff delivering quick treatment in a positive manner and in good co‐operation. HBOT sessions, in groups, were described as unproblematic and pleasant, through sharing experiences with others, although time‐consuming and tiring. Recognising the responsible physician and communication with other physicians in the health‐care chain was perceived as problematic. Placebo treatment, when given, did not reveal any problems; many perceived HBOT as the last resort and respondents had a negative view of future health and expressed fears of new wounds and amputation.Conclusions and relevance to clinical practice.  From patients’ perspective HBOT in the delivered health‐care model was perceived as well‐functioning, taking into consideration both technical and relational aspects of care in this high‐technology environment. Communication with the patient and between different care givers, with a consistent message given and information about who is responsible and to whom one should turn, wherever treated, is the most crucial aspect of the model. Future fears need to be recognised and group interaction can be encouraged to share the burden of disease.
Duration of symptom onset to hospital admission and admission to discharge or death in SARS in mainland China: a descriptive study
Authors: Feng Dan , Jia Na , Fang Li‐Qun , Richardus Jan Hendrik , Han Xiao‐Na , Cao Wu‐Chun , De Vlas Sake J. 
Published: June 2009

SummaryObjective  To describe and analyse factors associated with the duration of disease onset to hospital admission, admission to discharge and admission to death for severe acute respiratory syndrome (SARS), using the recently developed comprehensive database covering all regions of mainland China, and compare the results within and outside China.Methods  The database included all probable 5327 SARS cases, of whom 343 died. Linear regression (uni‐ and multivariate analysis) was performed for all three durations to test the impact of the following variables: sex, age, occupation, geographic location and period of the SARS epidemic (time since the first case, i.e. 16 November 2002).Results  The average duration of onset of symptoms to hospital admission was 3.8 days, of admission to discharge for those who survived was 29.7 days, while admission to death for casualties was 17.4 days. Health care workers, patients from Tianjin and patients infected towards the end of the epidemic had the shortest duration of onset to admission. Regarding admission to discharge, particularly young patients and patients from Guangdong had the shortest duration. Older age was the sole factor associated with shorter duration of admission to death.Conclusions  The average duration and pattern (with time of epidemic and age) of onset of symptoms to hospital admission of SARS patients in mainland China were comparable to other affected areas. The duration of hospital admission to discharge was shorter than elsewhere, possibly because of different hospitalisation policies. The duration of hospital admission to death in mainland China, however, appeared to be shorter than in other areas, which is in striking contrast to the much lower case fatality in mainland China.
The economic impact of SARS in Beijing, China
Authors: Beutels Philippe , Jia Na , Zhou Qing‐Yi , Smith Richard , Cao Wu‐Chun , De Vlas Sake J. 
Published: June 2009

SummaryObjective  To document the impact of the severe acute respiratory syndrome (SARS) outbreak in Beijing on indicators of social and economic activity.Methods  Associations between time series of daily and monthly SARS cases and deaths and volume of public train, airplane and cargo transport, tourism, household consumption patterns and gross domestic product growth in Beijing were investigated using the cross‐correlation function.Results  Significant correlation coefficients were found for all indicators except wholesale accounts and expenditures on necessities, with the most significant correlations occurring with a delay of 1 day to 1 month.Conclusions  Especially leisure activities, local and international transport and tourism were affected by SARS particularly in May 2003. Much of this consumption was merely postponed; but irrecoverable losses to the tourist sector alone were estimated at about US$ 1.4 bn, or 300 times the cost of treatment for SARS cases in Beijing.
Detection of Chalara fraxinea in common ash (Fraxinus excelsior) using real time PCR
Authors: Chandelier A. , André F. , Laurent F. 
Published: June 2009

SummaryA real time PCR assay was developed for the detection of Chalara fraxinea in common ash. PCR primers and Taqman probes, based on the internal transcribed spacer region of the multi‐copy gene rDNA, were tested for specificity and sensitivity. The primers amplified an 81 bp fragment for C. fraxinea but did not amplify DNA from other Chalara species or from other fungi isolated from ash, whether pathogenic or saprophytic. The limit of detection was 5 pg of genomic DNA per PCR. Moreover, naturally‐infected samples were correctly diagnosed. A procedure for DNA extraction from woody tissues using an electric drill yielded DNA of an appropriate quality for real time PCR. This molecular method could be useful for routine analysis of this emergent pathogen and for epidemiological studies.
Efficiency of farmers' selection in a participatory barley breeding programme in Jordan
Authors: Fufa F. , Grando S. , Kafawin O. , Shakhatreh Y. , Ceccarelli S. 
Published: June 2009

With 1 figure and 4 tables AbstractThe study assessed farmers’ and breeders’ selection efficiencies in one cycle of selection in a participatory barley breeding program. The selectors were compared with each other for objectively measured agronomic traits and for their selection scores. Farmers’ scores were positively correlated with grain yield in all locations while breeders’ scores not always. The selection criteria of farmers varied with location; those in low‐moisture areas selected for tall plants while those in high rainfall area for short. Breeders’ gave high scores to tall entries regardless of the selection environment. The results showed that in all locations farmers were at least as efficient as or, in most cases, more efficient than breeders in identifying high yielding genotypes with desirable traits for their specific environment indicating their competence in selection. Breeders appeared to select for their wide geographic mandate area while farmers focused on their specific locality. The finding indicates that decentralized participatory plant breeding is important to increase and stabilize productivity and maintain genetic diversity as each pocket area is occupied by the best and different genotypes.
Relationship between costs of lifestyle interventions and weight loss in overweight adults
Authors: Bogers R. P. , Barte J. C. M. , Schipper C. M. A. , Vijgen S. M. C. , De Hollander E. L. , Tariq L. , Milder I. E. J. , Bemelmans W. J. E. 
Published: June 2009

SummaryLifestyle interventions in a healthcare setting are effective for weight loss, but it is unclear whether more expensive interventions result in more weight loss. Our objective was to explore the relationship between intervention costs and effectiveness in a systematic review of randomized trials.Intervention studies were selected from 14 reviews and from a systematic MEDLINE‐search. Studies had to contain a dietary and a physical activity component and report data on measured weight loss in healthy Caucasian overweight adults. Intervention costs were calculated in a standardized way. The association between costs and percentage weight loss after 1 year was assessed using regression analysis.Nineteen original studies describing 31 interventions were selected. The relationship between weight loss and intervention costs was best described by an asymptotic regression model, which explained 47% of the variance in weight loss. A clinically relevant weight loss of 5% was already observed in interventions of approximately €110. Results were similar in an intention‐to‐treat analysis.In conclusion, lifestyle interventions in health care for overweight adults are relatively cheap and higher intervention costs are associated with more weight loss, although the effect of costs on weight loss levels off with growing costs.
Nested species subsets of amphibians and reptiles on Neotropical forest islands
Authors: Watling J. I. , Gerow K. , Donnelly M. A. 
Published: June 2009

AbstractNested species subsets are a common pattern of community assembly characteristic of many types of fragmented landscapes and insular systems. Here we describe nested subset patterns of amphibian and reptile occupancy on 23 forest islands in north‐eastern Bolivia. We used observed occupancy patterns to differentiate five distributional guilds: widespread species, rare species, poor colonizers, area‐sensitive species and supertramps. Amphibian occurrences were nested along a forest island isolation gradient, and when species from each of the distribution classes were removed from subsequent analyses of nestedness, we found that dispersal‐limited poor colonizers were responsible for the association between nestedness and isolation. Amphibians associated with the grassland matrix at the study site showed a nested pattern linked with area, although this pattern did not scale up to all amphibians and could not be unequivocally attributed to any of the distributional guilds we recognized. There were no strong associations between two biological characteristics, body size and relative abundance in the matrix, and the likelihood of occupancy along either forest island area or isolation gradients. The relative importance of isolation in shaping nested patterns of amphibians on these forest islands may be a result of either (1) the greater range in isolation values included in this study compared with many others; (2) the long time since isolation in this landscape, manifesting a footprint of isolation not apparent in more recently fragmented patches; (3) the relatively homogeneous grassland matrix surrounding forest islands that likely provides little refuge for animals moving among forest islands.
PACAP regulates immediate catecholamine release from adrenal chromaffin cells in an activity‐dependent manner through a protein kinase C‐dependent pathway
Authors: Kuri Barbara A. , Chan Shyue‐An , Smith Corey B. 
Published: June 2009

AbstractAdrenal medullary chromaffin cells are a major peripheral output of the sympathetic nervous system. Catecholamine release from these cells is driven by synaptic excitation from the innervating splanchnic nerve. Acetylcholine has long been shown to be the primary transmitter at the splanchnic‐chromaffin synapse, acting through ionotropic nicotinic acetylcholine receptors to elicit action potential‐dependent secretion from the chromaffin cells. This cholinergic stimulation has been shown to desensitize under sustained stimulation, yet catecholamine release persists under this same condition. Recent evidence supports synaptic chromaffin cell stimulation through alternate transmitters. One candidate is pituitary adenylate cyclase activating peptide (PACAP), a peptide transmitter present in the adrenal medulla shown to have an excitatory effect on chromaffin cell secretion. In this study we utilize native neuronal stimulation of adrenal chromaffin cellsin situand amperometric catecholamine detection to demonstrate that PACAP specifically elicits catecholamine release under elevated splanchnic firing. Further data reveal that the immediate PACAP‐evoked stimulation involves a phospholipase C and protein kinase C‐dependant pathway to facilitate calcium influx through a Ni2+and mibefradil‐sensitive calcium conductance that results in catecholamine release. These data demonstrate that PACAP acts as a primary secretagogue at the sympatho‐adrenal synapse under the stress response.
Treatment with the Kv7 potassium channel activator flupirtine is beneficial in two independent mouse models of pulmonary hypertension
Authors: Morecroft I , Murray A , Nilsen M , Gurney AM , MacLean MR 
Published: June 2009

Background and purpose: Voltage‐gated potassium (Kv) channels contribute to resting membrane potential in pulmonary artery smooth muscle cells and are down regulated in patients with pulmonary arterial hypertension (PAH) and a contribution from Kv7 channels has been recently proposed. We investigated the effect of the Kv7 channel activator, flupirtine, on PAH in two independent mouse models: PAH induced by hypoxia and spontaneous PAH in mice over‐expressing the 5‐HT transporter (SERT+mice).Experimental approach: Right ventricular pressure was assessedin vivoin mice chronically treated with flupirtine (30 mg·kg−1·day−1). In separatein vitroexperiments, pulmonary arteries from untreated mice were mounted in a wire myograph. Relaxations to acute administration of flupirtine and contractions to Kvchannel blocking drugs, including the Kv7 channel blocker linopirdine, were measured.Key results: In wild‐type (WT) mice, hypoxia increased right ventricular pressure, pulmonary vascular remodelling and right ventricular hypertrophy. These effects were attenuated by flupirtine, which also attenuated these indices of PAH in SERT+mice. In thein vitroexperiments, flupirtine induced a potent relaxant response in arteries from untreated WT and SERT+mice. The relaxation was fully reversed by linopirdine, which potently contracted mouse pulmonary arteries while other Kvchannel blockers did not.Conclusions and implications: Flupirtine significantly attenuated development of chronic hypoxia‐induced PAH in mice and reversed established PAH in SERT+mice, apparently via Kv7 channel activation. These results provide the first direct evidence that drugs activating Kv7 channels may be of benefit in the treatment of PAH with different aetiologies.
Oxidative stress may enhance the malignant potential of human hepatocellular carcinoma by telomerase activation
Authors: Nishikawa Taichiro , Nakajima Tomoki , Katagishi Tatsuo , Okada Yoshihisa , Jo Masayasu , Kagawa Keizo , Okanoue Takeshi , Itoh Yoshito , Yoshikawa Toshikazu 
Published: June 2009

AbstractBackground/Aims: Continuous oxidative stress (OS) plays an important role in the progression of chronic liver diseases and hepatocarcinogenesis through telomere shortening in hepatocytes. However, it has not been established how the OS influences the progression of human hepatocellular carcinomas (HCCs). We examined the correlations of OS with telomere length of cancer cells, telomerase activity and other clinicopathological factors in 68 HCCs.Methods: The level of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) as a marker of OS was examined immunohistochemically and OS was scored in four grades (0–3). The telomere length of cancer cells was measured by quantitative fluorescence in situ hybridization. Telomerase activity was measured by (i) immunodetection of human telomerase reverse transcriptase (hTERT) and (ii) telomere repeat amplification protocol (TRAP) assay. Telomerase related proteins, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and Akt, and other clinicopathological factors were also evaluated.Results: As the OS grade increased, the average telomere length became significantly shorter in HCCs, especially in the hTERT‐negative group. In the state of high‐grade OS, hTERT‐positive HCC cells showed more proliferative and less apoptotic features compared with hTERT‐negative HCC cells. Telomerase activity, as measured by the TRAP assay, was strongly correlated with OS grade in HCCs. Furthermore, a high OS grade was correlated with the downexpression of PTEN and the activation of Akt.Conclusions: Oxidative stress enhanced the malignant potential of HCCs through the activation of telomerase, which raises the possibility of using OS as a marker for assessing the clinical state of HCCs.
Paracorporeal Artificial Heart in Postoperative Heart Failure
Authors: Turina Marko T. , Bosio R. , Senning Åke 
Published: June 2009

ABSTRACTA pneumatically driven artificial heart with a tubular silicone rubber membrane and disc valves was used for functional heart replacement in the paracorporeal mode. A fluidic drive system allows adjustment of the heart rate, positive and negative pressures and systole/diastole ratio.Since August, 1977, the artificial heart has been used in four patients with refractory postoperative heart failure not responding to volume loading, pH and electrolyte correction, catecholamines and intraaortic balloon pumping. Large cannulae were placed in the atria and great vessels. The ventricles were fixed on the chest paracorporeally. The assist system was used as a left heart bypass in one patient and as a biventricular bypass in three other patients. After 48–72 hours, the ventricular function recovered in three patients, permitting removal of the artificial heart. One patient died of cerebral complications six weeks later; the other two recovered completely and were released in good condition.Profound postoperative heart failure can be completely reversed by the use of the paracorporeal artificial heart; the advantage of the system lies in the simplicity of its implantation and removal.