bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of natural antioxidants on stored freeze‐dried food product formulated using horse mackerel (Trachurus trachurus)
Authors: Sarkardei Samiramis , Howell Nazlin K. 
Published: July 2010

SummaryThe physical and chemical properties of Trachurus trachurus (horse mackerel) as well as a food product in the presence and absence of natural antioxidants, were investigated. The rate of lipid oxidation in the freeze‐dried horse mackerel product stored at room temperature (22 °C) was investigated, using peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and hexanal concentration to determine primary, secondary and tertiary oxidation products. Natural antioxidants were used to slow down oxidation processes and to improve nutritional and eating quality. These included vitamin E + vitamin C + citric acid (250, 250, 100 mg kg−1, respectively), vitamin E + vitamin C + citric acid + rosemary (250, 250, 100, 250 mg kg−1, respectively) and rosemary (250 mg kg−1). Biochemical analysis such as PV and TBARS measurements showed that the combination of vitamin E + vitamin C + citric acid (250, 250, 100 mg kg−1) were found to be the most significant (P ≤ 0.01) in controlling the rate of lipid oxidation in freeze‐dried food followed by rosemary (250 mg kg−1). There was an initial rise in the PV of all samples, which dropped after 8 weeks, because of formation of secondary oxidation products. The rise in PV was much higher in the control samples with no antioxidants added, compared with the antioxidant‐treated samples. Combinations of E + C + citric acid treatment group followed by rosemary alone were the most significant in lowering PV, hence, reducing formation of primary oxidation products (P ≤ 0.01). Once the primary oxidation products were lowered, TBARS levels (secondary oxidation products) increased in control samples after 12 weeks; however, in E + C + citric acid treatment group and rosemary‐treated samples, this increase was significantly lower (P ≤ 0.01). There was a rise in hexanal concentration for up to 8 weeks, which dropped only in the antioxidant‐treated groups and continued to rise in the control samples.
Geographic variation in seed mass within and among nine species of Pedicularis (Orobanchaceae): effects of elevation, plant size and seed number per fruit
Authors: Guo Hui , Mazer Susan J. , Du Guozhen 
Published: July 2010

Summary 1. We examined geographic variation in mean individual seed mass (MISM) among 38 populations within and across nine Pedicularis species in the eastern Tibetan Plateau, measuring the effects of one extrinsic factor (elevation) and two intrinsic factors (plant size and mean seed number per fruit). 2. Across all populations, elevation is negatively correlated with MISM; within eight of nine species, this pattern is also observed among populations. This relationship, however, is not significant when controlling for variation in plant size or seeds per fruit. High‐elevation populations produce smaller plants with more seeds per fruit than low‐elevation populations; controlling for these variables eliminates the negative correlation between elevation and MISM. 3. Across all populations, the predicted trade‐off between MISM and seeds per fruit is consistently strong, with or without controlling for the effects of plant size. By contrast, the trade‐off between MISM and total seasonal fecundity can be detected only when controlling for plant size. 4. Independent of plant size, populations that produce small seeds do not support individuals with particularly low reproductive yield (fecundity × MISM). Accordingly, high‐elevation populations exhibit neither lower reproductive yield nor smaller seeds than expected given their lower biomass. 5. Synthesis. In Pedicularis, elevation, plant size and seeds per fruit are all correlated with MISM among populations across species. Elevation is less important, however, than intrinsic factors in determining the MISM of a population; the effect of elevation on MISM disappears when the effects of intrinsic factors are controlled statistically. The observed decline in MISM with increasing elevation is therefore partly mediated by the decline in plant size and partly by an increase in mean seed number per fruit with elevation. Altitudinal variation in MISM across populations or species has been described before, but this is the first study to control for the effect of intrinsic factors simultaneously. This result calls into question the conclusions of studies that have detected geographic variation in MISM without controlling for variation in intrinsic factors.
Ultramafic soils and species sorting in the flora of New Caledonia
Authors: Pillon Yohan , Munzinger Jérôme , Amir Hamid , Lebrun Michel 
Published: July 2010

Summary1. Island floras are generally characterized by disharmony due to uneven representations of plant groups. This has usually been explained by the unequal capacity of plants to disperse and colonize islands, but it has been suggested that the ecology of the recipient islands may also be important.2. We investigated the phylogenetic structure of the flora of New Caledonia, a biodiversity hotspot in the South‐West Pacific, to examine the phylogenetic pattern of a disharmonic flora and to test two competing hypotheses: disharmony due to uneven dispersability versus disharmony due to uneven ability to adapt to the ultramafic soils that are widespread on the archipelago and constrain plant growth.3. Dispersal did not seem to be a significant factor as plant families with low levels of endemism and thus high effective dispersal capacities tended to be under‐represented.4. We identified several clusters of over‐represented families, such as the COM clade (Celastrales, Oxalidales and Malpighiales), in which nickel hyperaccumulation (a syndrome associated with ultramafic soils) was particularly common. We indeed found a positive association between hyperaccumulation and over‐representation. Therefore, ultramafic soils may have been a major force for species sorting in the flora of New Caledonia.5. Because we think that most colonizers were naïve to ultramafic soils before they reached the archipelago, the over‐represented groups in New Caledonia may have possessed an exaptation to ultramafic soils, which has facilitated their settlement and diversification.6. Synthesis. This study supports that beyond dispersal, ecology is an important factor in determining the success of different plant groups to colonize an island. In the case of New Caledonia, exaptation to ultramafic soils is likely a primary cause of ecological filtering.
Can optimal defence theory be used to predict the distribution of plant chemical defences?
Authors: McCall Andrew C. , Fordyce James A. 
Published: July 2010

Summary 1. The optimal defence theory (ODT) of chemical defence provides a predictive framework for the distribution of anti‐herbivore defences in plants. One of its predictions is that chemical defences will be allocated within a plant as a function of tissue value, where value is correlated with the cost of having that tissue removed. While many studies have examined intra‐plant variation in defence chemistry, these results have rarely been compiled quantitatively to assess whether defence allocation is consistent with the prediction of ODT that more valuable tissues should be more defended than less valuable tissues. 2. We performed a formal meta‐analysis of published and unpublished studies to examine the predictive utility of ODT. Specifically, we examined whether defence chemicals occur at higher concentrations in flowers versus leaves and in younger leaves compared to older leaves, under the assumption that younger leaves are more valuable than older leaves. We also examined whether the expansion status of younger leaves, nodal position of the leaves, growing conditions and chemical class of defence compounds affected the mean effect sizes. 3. We found that tissues with higher assumed value had significantly higher concentrations of defence chemicals than tissues with lower value. In particular, we found that younger leaves had higher concentrations of defence chemicals than older leaves, consistent with the predictions of ODT. The magnitude of this difference was higher in the younger leaf/older leaf comparison than in the flower/leaf comparison, with no evidence that flowers were more defended than leaves. The overall results were not affected by chemical class, young leaf expansion status, growing conditions or leaf position on the plant. 4. Synthesis. We found general agreement between the predictions of ODT and the intraplant distribution of chemical defence and conclude it is a useful model. The effect size varied depending on the tissue compared. Explicit measures of tissue value, in particular as it relates to relative fitness, are required to further validate the predictive utility and general applicability of ODT.
Ant‐mediated seed dispersal does not facilitate niche expansion
Authors: Warren Robert J. , Giladi Itamar , Bradford Mark A. 
Published: July 2010

Summary 1. Whereas classic niche theory is based on the contraction of the niche via negative interactions, facilitative niche theory suggests that mutualisms can expand the niche via positive interactions. Specifically, animal‐mediated seed dispersal can expand the utilization of physical space by plants and allow greater access to resources and other environmental requirements. Ant‐mediated dispersal of plant propagules (myrmecochory) is a common mutualism throughout the world, particularly in the deciduous forests of the eastern United States where this research is conducted. 2. We examine two facets of niche expansion via ant‐mediated seed dispersal: (1) increased utilization of resources along resource gradients and (2) escape from unfavourable density‐dependent conditions. 3. We test these assumptions by introducing Hexastylis arifolia seeds in cafeteria‐style bait stations along abiotic gradients (moisture, temperature, light) for removal by key seed dispersers from the ant genus Aphaenogaster. We also examine plant aggregation along the same gradients. 4. Ant‐mediated dispersal services decrease significantly with increasing soil moisture and ultimately fail at levels that are demonstratively within the plant’s niche optima; further, the decline in dispersal services is correlated with increasing plant aggregation, suggesting that enemy escape also falters at relatively high levels of soil moisture. 5. Synthesis. Facilitated propagule dispersal fails to expand the Hexastylis arifolia niche in either enhanced resource utilization or decreased density dependence as the niche requirements for the ant disperser are nested within those for the plant. The strength of this interaction varies across space and time, and in doing so may undermine attempts to predict future distributions. Further, given that myrmecochores are typically poor dispersers, the incomplete niche overlap between the plant and its facilitator makes this plant guild particularly susceptible to climatic change if each participant responds individually to shifting environmental conditions.
Plant–soil feedback: experimental approaches, statistical analyses and ecological interpretations
Authors: Pernilla Brinkman E. , Van der Putten Wim H. , Bakker Evert‐Jan , Verhoeven Koen J.F. 
Published: July 2010

Summary 1. Feedback between plants and soil organisms has become widely recognized as a driving force of community composition and ecosystem functioning. However, there is little uniformity in quantification and analysis of plant–soil feedback effects. Meta‐analysis suggested that the various experimental methods tend to result in different feedback values. Yet, a direct comparison of the different experimental approaches and their statistical analyses is lacking. 2. We used currently applied methods to calculate plant–soil feedback value ranges and compared their statistical analyses to those based on actual biomass data. Then, we re‐analysed a case study to compare plant–soil feedback values obtained under the same environmental conditions, but using different experimental approaches: soil sterilization, addition of soil inoculum, and soil conditioning by ‘own’ vs. ‘foreign’ plant species. 3. Different measures to calculate plant–soil feedback values were more variable in positive than in negative feedback values. Analysis of calculated feedback values that are based on treatment averages can lead to a serious inflation of type I errors. 4. In our case study, both the strength and the direction of the feedback effects depended on the experimental approach that was chosen, leading to diverging conclusions on whether feedback to a certain soil was positive or negative. Soil sterilization and addition of soil organisms yielded larger feedback than comparison of own and foreign soil. 5. Synthesis. The ecological interpretation of plant–soil feedback effects strongly depends on the experimental procedure. When the research question focuses on the strength and the sign of plant–soil feedback, soil sterilization (presumed that the side effect of increased nutrient availability can be controlled) or addition of soil inoculum is to be preferred. When the research question concerns the specificity of soil feedback effects, plant performance can be better compared between own and foreign soil. We recommend that when using calculated feedback values, the original data need to be presented as well in order to trace the cause of the effect.
Complex responses to climate drivers in onset of spring flowering across a semi‐arid elevation gradient
Authors: Crimmins Theresa M. , Crimmins Michael A. , David Bertelsen C. 
Published: July 2010

Summary 1. Many studies have documented advancement in spring plant phenology; however, studies in dry climates, where water, rather than temperature, is the limiting factor, are rare. To better understand how plants of a water‐limited environment may respond to predicted changes in climate, we used a species‐rich 20‐year data set collected in a semi‐arid ecosystem to determine species’ relationships with precipitation and temperature for seasons coincident with and previous to flowering. Our data were collected across a 1200‐m elevation gradient, allowing us to explore the consistency in relationships with climatic variables from desert scrub to pine forest. A second objective was to document evidence of changes in the onset of spring flowering over this 20‐year period. 2. Onset of spring flowering for species at the lowest elevations was most commonly driven by temperature and precipitation conditions of the previous autumn. In contrast, onset of spring flowering for species in high‐elevation communities was more often associated with spring temperatures, a pattern consistent with communities of higher latitudes. Despite these coarse patterns, species’ relationships to climate variables were highly variable and individualistic. 3. Approximately 10% of species showed a significant trend in changes in first flowering date over the period 1984–2003; most trends were in the direction of later onset. The decrease in autumn precipitation observed over the study period appears to explain the delay in onset observed for many of the species across the elevation gradient. Other species’ delays in spring flowering appear to be related to the slight decrease in spring temperature observed over the study period. 4. Synthesis. The south‐western USA is expected to become warmer and drier. Climate relationships documented in this study suggest divergent, individualistic changes in the onset of spring flowering. Low‐elevation plants may exhibit delayed spring flowering due to changes in the timing or amount of precipitation or insufficient chilling. High‐elevation species may show advancement in spring flowering due to warming temperatures. The highly individualistic responses to climate change may result in significant changes in the diversity, composition and abundance of plants in flower. Variable changes in phenology such as these have major implications for species population dynamics and ecosystem functioning.
Factors influencing inappropriate use of ED visits among type 2 diabetics in an evidence‐based management programme
Authors: Chiou Shang‐Jyh , Campbell Claudia , Myers Leann , Culbertson Richard , Horswell Ronald 
Published: July 2010

AbstractObject  This study analyses inappropriate use of emergency department (ED) services among type 2 diabetics under an evidence‐based management programme.Methods  Using 1999‐2006 databases of Louisiana Health Care Services Division (HCSD) eight public hospitals ED visits among the uninsured and other patients in Louisiana, we termed urgent ED visits appropriate and less‐urgent visits inappropriate. Eliminating weekend ED visits, 17 458 urgent and 22 395 less‐urgent visits by 8596 patients were analysed, using generalized estimating equation methods.Results  Caucasians were 0.82 times (95% CI: 0.751–0.889) less likely to use the ED inappropriately compared with African Americans. Patients with commercial insurance, Medicaid and Medicare used the ED more inappropriately than uninsured, with odds ratios of 1.28, 1.32 and 1.28, respectively. Patients hospitalized the prior year were 0.84 times (95% CI: 1.08–1.31) less likely for inappropriate. Patients in larger hospitals used the ED more inappropriately, with an odds ratio of 1.44 (95% CI: 1.32–1.56).Conclusions  The study suggests that inappropriate use of the ED among diabetic patients in an evidence‐based management programme is more likely to occur among African American, patients with insurance coverage and those seeking care in larger hospitals. Reinforcing the regular use of clinic services for diabetes management, providing clinic access in off‐hours, and engaging the health plans in providing incentives for more appropriate use of the ED might reduce inappropriate ED visits. Notably, uninsured patients with diabetes from HCSD were more efficient users of the ED.
A review of cost‐effectiveness, cost‐containment and economics curricula in graduate medical education
Authors: Varkey Prathibha , Murad Mohammad H. , Braun Chad , Grall Kristi J.H. , Saoji Vivek 
Published: July 2010

AbstractObjective  Numerous studies performed over the last 30 years suggest that doctors have poor knowledge of the costs of medical care. In most graduate medical education programmes, trainees do not receive formal training in cost‐effective medical practice.Methods  Comprehensive literature search of electronic bibliographic databases for articles that describe health economics, cost‐containment and cost‐effectiveness curricula in graduate medical education. Critical appraisal of the literature and qualitative description is presented. Heterogeneity of curricula precluded quantitative summary of data.Results  We identified 40 articles that met the inclusion criteria for this review. Internal medicine residents were the targeted learners in 27 studies (68%); Family Medicine and Surgery residents were each targeted in five studies (13%); Rehabilitation, Paediatrics and Emergency Medicine residents were each targeted in one study. In general, the methodological quality of the included studies was poor to moderate and mostly targeted knowledge of health economics or cost‐containment as opposed to targeting cost‐effectiveness. In terms of describing the standard curricular components, studies sufficiently described the different educational strategies (e.g. didactics, interactive, experiential, self‐directed) and the component of learner assessment, but lacked the description of other elements such as needs assessment and curriculum evaluation.Conclusion  Cost‐effectiveness curricula in graduate medical education are lacking and clearly needed.
Acute myocardial infarction – from territory to definitive treatment in an Italian province
Authors: Giuliani Enrico , Lazzerotti Sara , Fantini Giuseppe , Guerri Elisa , Serantoni Carlo , Modena Maria Grazia , Barbieri Alberto 
Published: July 2010

AbstractRationale, aims and objectives  Early reperfusion is the key to therapeutic success in acute myocardial infarction (AMI). The duration of the process is influenced by various factors which in most of the cases are not easily modifiable. The aim of this study is to analyse AMI treatment process duration to identify determining factors. The objective is to better exploit time intervals imposed by spatial distance from the hospital.Method  One‐year data regarding acute coronary syndromes with elevated ST segment for patients presenting to Policlinico teaching hospital (Modena, Italy) have been studied. Patients were divided into two groups for hospital access: A – ambulance access to Policlinico emergency room (ER); B – self‐referral to ER.Results  A total of 141 patients have undergone percutaneous transluminal coronary angioplasty for AMI at Policlinico, 106 males, 35 females (58.1% males in group A, 82.7% in B, P 0.002), with an average age of 66.09 ± 14.30 years in group A and 60.90 ± 13.47 in B (P 0.047). Mean pre‐hospital time for group A was 122.54 ± 130.69 minutes and B 171.49 ± 353.60 (P 0.25), mean hospital time in group A was 196.03 ± 67.66 and B 255.14 ± 113.16 (P < 0.001), mean total time in group A was 318.56 ± 146.91 and B 426.63 ± 382.01 (P 0.02).Discussion  Data show that group B suffered on average a 108‐minute delay from symptoms insurgence to definitive treatment. The duration of hospital time plays more important role in this finding than distance from the medical facility. In fact, on the ambulance a medical crew starts the diagnostic and therapeutic process relieving ER from initial evaluation.
Clinical effectiveness in cardiovascular trials in relation to the importance to the patient of the end‐points measured
Authors: Bowater Russell J. , Lilford Richard J. 
Published: July 2010

AbstractBackground  In order to increase the statistical power of a trial design, it is common practice for trialists to place a strong emphasis on end‐points other than mortality. To assess the validity of this practice, the aim of this study was to investigate the relationship between the effectiveness of cardiovascular interventions in clinical trials and the importance to the patient of the end‐point used to measure this effectiveness.Methods  A reanalysis of a database of cardiovascular trials used in an earlier study. This database consists of all randomized controlled trials published in six leading journals for cardiovascular research between January 2002 and June 2003 that involve the exposure of humans to any therapeutic or primary preventive intervention for cardiovascular disease and report at least one composite end‐point.Results  On the basis of analysing the study data using a statistical modelling approach, the best estimate of the percentage of trials that have a true (not estimated) relative risk of less than 0.8 for the end‐point of moderate outcome, major outcome and death are 63%, 39% and 0% respectively, and the upper 95% confidence limits on these three percentages are 73%, 43% and 15% respectively.Conclusions  The proportion of interventions tested in the cardiovascular trials considered in this study that have a substantial beneficial effect relative to the control decreases as the end‐point used to measure this effect becomes more important to the patient, that is, as the end‐point severity increases from minor outcome to major outcome to death. Also, the analysis presented in this study strongly suggests that most of these interventions are likely to have close to no genuine effect on mortality relative to the control. Overall, this study substantially strengthens the empirical basis for the belief that the actions of trialists in choosing to study and heavily emphasize end‐points other than mortality in cardiovascular trials and in particular end‐points that are of only moderate or major importance to patients, may mislead practitioners and policy‐makers about the overall effectiveness of the intervention concerned.