bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibacterial iridoid glucosides from Eremostachys laciniata
Authors: Modaressi Masoud , Delazar Abbas , Nazemiyeh Hossein , Fathi‐Azad Fatemeh , Smith Eileen , Rahman M. Mukhlesur , Gibbons Simon , Nahar Lutfun , Sarker Satyajit D. 
Published: August 2008

AbstractEremostachys laciniata (L) Bunge (family: Lamiaceae alt. Labiatae; subfamily: Lamioideae) is one of the 15 endemic Iranian herbs of the genus Eremostachys. A decoction of the roots and flowers of E. laciniata has traditionally been taken orally for the treatment of allergies, headache and liver diseases. Three antibacterial iridoid glucosides, phloyoside I (1), phlomiol (2) and pulchelloside I (3) have been isolated from the rhizomes of this plant. The structures of these compounds were elucidated unequivocally by a series of 1D and 2D NMR analyses. The antibacterial activity and brine shrimp toxicity of these compounds were assessed using the resazurin microtitre assay and the brine shrimp lethality assay, respectively. All three iridoid glycosides 1–3 exhibited from low to moderate levels (MIC = 0.05–0.50 mg/mL) of antibacterial activity. Of these compounds, compound 3 was the most active, and displayed antibacterial activity against 9 of 12 different strains tested. The most noteworthy activity of 3 was against Bacillus cereus, penicillin‐resistant Escherichia coli, Proteus mirabilis and Staphylococcus aureus with an MIC value of 0.05 mg/mL. Copyright © 2008 John Wiley & Sons, Ltd.
Pharmacological in vivo test to evaluate the bioavailability of some St John's Wort innovative oral preparations
Authors: Isacchi B. , Galeotti N. , Bergonzi M. C. , Ghelardini C. , Bilia A.R. , Vincieri F. F. 
Published: August 2008

AbstractIn this study, the optimisation of biopharmaceutical properties of a dried commercial extract of St John's Wort were evaluated employing the in vivo forced swimming test (FST). Three new dosage forms containing β‐cyclodextrin and surfactants (SDS, ASC8) were compared in the FST with the commercial extract. The commercial extract showed antidepressant activity in mice after 60 min at a dosage of 100 mg/kg. The same antidepressant activity appeared in 30 min with a micellar solution of SDS containing the same quantity of extract (100 mg/kg), while with micelles of ASC8 the effect appeared at 15 min and with a dosage of 30 mg/kg. In the case of β‐cyclodextrin the best results were obtained at 30 min, administering 60 mg/kg of the extract. Finally, the influence of the formulations on the water solubility of the constituents of the extract is reported. The tensides dramatically enhanced solubility, in particular that of the more lipophilic compounds, in the case of β‐cyclodextrin this effect was very pronounced for flavonoids and biapigenin, lower for hypericins and practically insignificant for hyperforins. Copyright © 2008 John Wiley & Sons, Ltd.
Increased renal expression of nitric oxide synthase and atrial natriuretic peptide in rats with glycyrrhizic‐acid‐induced hypertension
Authors: Ma Seong Kwon , Bae Eun Hui , Kim In Jin , Choi Ki Chul , Kim Suhn Hee , Lee JongUn , Kim Soo Wan 
Published: August 2008

AbstractThe present study aimed to examine whether there is an altered regulation of local hormonal systems in the kidney following the treatment of glycyrrhizic acid (GA), the active ingredient in licorice. Male Sprague‐Dawley rats were treated with GA for 3 weeks. The expression of mineralocorticoid receptor (MR) was determined in the kidney by immunoblotting and real‐time polymerase chain reaction (PCR). The protein expression of endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) was determined. The expression of atrial natriuretic peptide (ANP), natriuretic peptide receptor (NPR)‐A and NPR‐C was determined by real‐time PCR. The activity of guanylyl cyclase was determined by the amount of cGMP generated in responses to sodium nitroprusside (SNP) or ANP. Following the GA treatment, systolic blood pressure was increased. The mRNA and protein expressions of MR were increased in the kidney. The protein expression of eNOS and iNOS was also increased. The expression of ANP mRNA was increased although that of NPR‐A and NPR‐C mRNA was not changed. The cGMP production provoked by either SNP or ANP was not changed. The increased expression of MR may contribute to GA‐induced hypertension. The enhanced expression of NOS and ANP may play a compensatory role in GA‐induced hypertension. Copyright © 2008 John Wiley & Sons, Ltd.
‘African potato’ (Hypoxis hemerocallidea corm): a plant‐medicine for modern and 21st century diseases of mankind? – a review
Authors: Owira Peter M. O. , Ojewole John A. O. 
Published: August 2008

AbstractThe traditional uses, therapeutic attributes, phytochemical and pharmacological profiles of ‘African potato’ (Hypoxis hemerocallidea corm) extracts have been reviewed. Available biomedical evidence suggests that ‘African potato’ is a potential plant‐medicine for some modern and 21st century diseases of mankind. Thus far, biomedical evidence has revealed that ‘African potato’ extracts possess antiinflammatory, antineoplastic, antioxidant, antidiabetic and antiinfective properties in vivo and in vitro. However, more laboratory and clinical studies are required to clarify these observations, and to isolate, purify and characterize the active chemical constituents responsible for the herb's pharmaco‐therapeutic effects. Copyright © 2008 John Wiley & Sons, Ltd.
Boundary‐layer ventilation by baroclinic life cycles
Authors: Sinclair V. A. , Gray S. L. , Belcher S. E. 
Published: August 2008

AbstractVentilation of the boundary layer has an important effect on local and regional air quality and is a prerequisite for long‐range pollution transport. Once in the free troposphere, pollutants can alter the chemical composition of the troposphere and impact on the Earth's radiative forcing. Idealised baroclinic life cycles, LC1 and LC2, have been simulated in a three‐dimensional dry hemispheric model in the presence of boundary‐layer turbulent fluxes. A passive tracer is added to the simulations to represent pollution emitted at, or near, the surface. A simple conveyor‐belt diagnostic is developed to objectively identify regions of the boundary layer that can be ventilated by either warm or cold conveyor belts. Transport of pollutants within and above the boundary layer is examined on synoptic scales. Three different physical mechanisms are found to interact with each other to ventilate pollutants out of the boundary layer. These mechanisms are turbulent mixing within the boundary layer, horizontal advection due to Ekman convergence and divergence within the boundary layer, and advection by the warm conveyor belt. The mass of tracer ventilated by the two life cycles is remarkably similar given the differences in frontal structure, suggesting that the large‐scale baroclinicity is an effective constraint on ventilation. Copyright © 2008 Royal Meteorological Society
Use of Canadian Quick covariances in the Met Office data assimilation system
Authors: Jackson D. R. , Keil M. , Devenish B. J. 
Published: August 2008

AbstractIn this paper, we describe the use of Canadian Quick (CQ) covariances in the Met Office assimilation system. These covariances have two particular advantages over other methods (such as the National Meteorological Center (NMC) method). First, they are calculated from a single long forecast run, rather than a series of short forecasts, and thus are much quicker to produce. Second, in cases where the vertical range of the assimilation system increases, they can be used immediately.Here, we compare the performance of CQ and NMC covariances in a troposphere/stratosphere configuration of the Met Office assimilation system. The forecast model used has 50 levels from the surface to 63 km. In general, the performance of the two covariances is similar. However, it is clear that a consequence of the bootstrapping approach that was used to develop the NMC covariances is noisy patterns in the error covariances which adversely affects mean errors, particularly in the winter middle and high latitudes above the 10 hPa level. In addition, the NMC covariances show evidence of gravity waves, which appear to have been generated spuriously by the 3D‐Var assimilation due to lack of dynamical balance in the 3D‐Var analyses. Such signals are absent in the trials where CQ covariances are used.The CQ method was also used to generate covariances for expanded versions of the model which spans the surface to around 80–84 km. Trial results are generally in good agreement with Earth Observing System Microwave Limb Sounder (EOS MLS) correlative measurements. Through this work, the CQ approach is proving to be a very effective tool for developing and testing new models which will be used to provide operational weather forecasts at the Met Office. The results show that the CQ approach is a quick and effective alternative to the NMC method, and can produce similar or sometimes better results. It is a particularly useful tool in the development of new assimilation systems. © Crown Copyright 2008 Reproduced with the permission of Her Majesty's St ationery Office. Published by J ohn Wiley & Sons, Ltd
Numerical test of a simple approach for using TOMS total ozone data in hurricane environment
Authors: Wu Yonghui , Zou X. 
Published: August 2008

AbstractUsing a regime‐dependent linear regression model that maps TOMS observed total column ozone (O3) into model mean vertically‐integrated potential vorticity (MPV): O3 = α × MPV + β, where the regression constants α and β are evaluated separately for data in regions strongly and weakly influenced by deep convection/southerly advection, respectively, TOMS ozone data can readily be incorporated into a hurricane forecast model. Case‐studies of several hurricanes are conducted applying such a simple regime‐dependent linear regression model to TOMS ozone data assimilation. Improvements in the track prediction are shown. A detailed analysis of how TOMS total ozone affects the track prediction is conducted for Hurricane Erin (2001). A significant improvement in the track prediction for Hurricane Erin (2001) using TOMS ozone occurred at about 20 hours into the model forecast, when the control forecast experiences a sudden increase of track error. It is found that such an improvement in the track prediction of Hurricane Erin is mainly due to differences in the steering flows of the two forecast experiments, resulting from the presence of an upstream middle‐latitude ozone trough and a downstream low‐latitude ozone trough. An examination of the time evolution of these two troughs in both forecast experiments indicates that both troughs became stronger and moved closer to Hurricane Erin with time in the forecast experiment with the assimilation of TOMS ozone data than did those in the control forecast. Copyright © 2008 Royal Meteorological Society
Development of a solenoid RF coil for animal imaging in 3 T high‐magnetic‐field MRI
Authors: Lee Hong‐Seok , Woo Dong‐Cheol , Min Kwang‐Hong , Kim Yong‐Kwon , Lee Heung‐Kyu , Choe Bo‐Young 
Published: August 2008

AbstractThe purpose of this study was to develop a solenoid coil for use with small animals in a 3 Tesla horizontal magnetic resonance imaging (MRI) system, and to investigate image quality by examination of parameters such as signal‐to‐noise ratio (SNR) and Q‐factor. A receiver solenoid coil was formed by winding three separate coils of copper tape around an acryl cylinder. The cylinder was supported at each end. A euthanized rat weighing 240 g was used as a subject animal for imaging. A cylindrical plastic tube containing a solution of 0.7 g/L CuSO4 was used as a phantom. Measured SNRs were 985 in the phantom image 995 in the rat. The Q‐factor was 89 in the phantom and 84 in the rat, in the loaded condition. The homogeneity of the radiofrequency (RF) field was good and the resolution of the image was sufficient to distinguish internal organs from one another in the abdomen of a rat. This study has demonstrated that a solenoid coil may be used to produce good quality images of small animals. SCANNING 30: 419–425, 2008. © 2008 Wiley Periodicals, Inc.
Combating against internet worms in large‐scale networks: an autonomic signature‐based solution
Authors: Simkhada Kumar , Taleb Tarik , Waizumi Yuji , Jamalipour Abbas , Nemoto Yoshiaki 
Published: August 2008

AbstractIn this paper, we propose a signature‐based hierarchical email worm detection (SHEWD) system to detect e‐mail worms in large‐scale networks. The proposed system detects novel worms and instantly generates their signatures. This feature helps to check the spread of any kind of worm—knownorunknown.We envision a two‐layer hierarchical architecture comprising local security managers (LSMs), metropolitan security managers (MSM), and a global security manager (GSM). Local managers collectsuspiciousflows and hand them to metropolitan managers. Metropolitan managers then use cluster analysis to sort worms from the suspicious flows. The sorted worms are used to generate the worm signature which is relayed to the global manager and then to all the collaborating networks. A separate scheme is proposed to automatically select suitable values of the system parameters. This parameter selection procedure takes into account the current network state and thethreat levelof the ongoing attack. The performance of the whole system is investigated using real network traffic with traces of worms. Experimental results demonstrate that the proposed scheme is capable to accurately detect email worms during the early phase of their propagations. Copyright © 2008 John Wiley & Sons, Ltd.
Brain mapping with transcranial magnetic stimulation using a refined correlation ratio and Kendall's τ
Authors: Matthäus L. , Trillenberg P. , Fadini T. , Finke M. , Schweikard A. 
Published: August 2008

AbstractTranscranial magnetic stimulation provides a mean to stimulate the brain non‐invasively and painlessly. The effect of the stimulation hereby depends on the stimulation coil used and on its placement. This paper presents a mapping algorithm based on the assumption of a monotonous functional relationship between the applied electric field strength at the representation point of a muscle and the evoked motor potential. We combine data from coil characteristics, coil placement, and stimulation outcome to calculate a likelihood map for the representation of stimulated muscles in the brain. Hereby, correlation ratio (CR) and Kendall's rank coefficient τ are used to find areas in the brain where there is most likely a functional or monotonous relationship between electric field strength applied to this area and the muscle response. First results show a good accordance of our method with mapping from functional magnetic resonance imaging.In our case, classical evaluation of CR with binning is impossible, because sample data sets are too small and data are continuous. We therefore introduce a refined CR formula based on a Parzen windowing of the X‐data to solve the problem. In contrast to usual windowing approaches, which require numeric integration, it can be evaluated directly in O(n2) time. Hence, its advantage lies in fast evaluation while maintaining robust applicability to small sample sets. We suggest that the presented formula can generally be used in CR‐related problems where sample size is small and data range is continuous. Copyright © 2008 John Wiley & Sons, Ltd.
Combining data from primary and ancillary surveys to assess the association between neighborhood‐level characteristics and health outcomes: the Multi‐Ethnic Study of Artherosclerosis
Authors: Sánchez B. N. , Raghunathan T. E. , Diez Roux A. V. , Zhu Y. , Lee O. 
Published: August 2008

AbstractThere is increasing interest in understanding the role of neighborhood‐level factors on the health of individuals. Many large‐scale epidemiological studies that accurately measure health status of individuals and individual risk factors exist. Sometimes these studies are linked to area‐level databases (e.g. census) to assess the association between crude area‐level characteristics and health. However, information from such databases may not measure the neighborhood‐level constructs of interest. More recently, large‐scale epidemiological studies have begun collecting data to measure specific features of neighborhoods using ancillary surveys. The ancillary surveys are composed of a separate, typically larger, set of individuals. The challenge is then to combine information from these two surveys to assess the role of neighborhood‐level factors. We propose a method for combining information from the two data sources using a likelihood‐based framework. We compare it with currently used ad hoc approaches via a simulation study. The simulation study shows that the proposed approach yields estimates with better sampling properties (less bias and better coverage probabilities) compared with the other approaches. However, there are cases where some ad hoc approaches may provide adequate estimates. We also compare the methods by applying them to the Multi‐Ethnic Study of Atherosclerosis and its Neighborhood Ancillary Survey. Copyright © 2008 John Wiley & Sons, Ltd.
Graphical diagnostics to check model misspecification for the proportional odds regression model
Authors: Liu Ivy , Mukherjee Bhramar , Suesse Thomas , Sparrow David , Park Sung Kyun 
Published: August 2008

AbstractThe cumulative logit or the proportional odds regression model is commonly used to study covariate effects on ordinal responses. This paper provides some graphical and numerical methods for checking the adequacy of the proportional odds regression model. The methods focus on evaluating functional misspecification for specific covariate effects, but misspecification of the link function can also be dealt with under the same framework. For the logistic regression model with binary responses, Arbogast and Lin (Statist. Med.2005;24:229–247) developed similar graphical and numerical methods for assessing the adequacy of the model using the cumulative sums of residuals. The paper generalizes their methods to ordinal responses and illustrates them using an example from the VA Normative Aging Study. Simulation studies comparing the performance of the different diagnostic methods indicate that some of the graphical methods are more powerful in detecting model misspecification than the Hosmer–Lemeshow‐type goodness‐of‐fit statistics for the class of models studied. Copyright © 2008 John Wiley & Sons, Ltd.
Bias in frequently reported analyses of subfertility trials
Authors: Dias Sofia , McNamee Roseanne , Vail Andy 
Published: August 2008

AbstractRandomized controlled trials in subfertility are often designed so that participants in each trial arm are offered the randomized treatment for up to k cycles, until success occurs. In clinical journals, success probabilities are often reported ‘per cycle’ and inferential procedures carried out as if all cycles were independent. However, this assumption does not hold. In this paper we consider the implications of such an assumption when we have a heterogeneous (Beta) patient population. We conducted a simulation study to assess the bias of estimates of the risk difference, risk ratio and odds ratio calculated using the total number of randomized women or the total number of treatment cycles as the unit of analysis, as well as the coverage of their confidence intervals (CIs). We found that the commonly reported ‘per cycle’ analyses are more biased and have poorer coverage of the CIs than the analyses based on the total number of women, in heterogeneous populations. Such information will help researchers who wish to interpret publications when the number of randomized participants is not extractable. Copyright © 2008 John Wiley & Sons, Ltd.
Joint analysis of multi‐level repeated measures data and survival: an application to the end stage renal disease (ESRD) data
Authors: Liu Lei , Ma Jennie Z. , O'Quigley John 
Published: August 2008

AbstractShared random effects models have been increasingly common in the joint analyses of repeated measures (e.g. CD4 counts, hemoglobin levels) and a correlated failure time such as death. In this paper we study several shared random effects models in the multi‐level repeated measures data setting with dependent failure times. Distinct random effects are used to characterize heterogeneity in repeated measures at different levels. The hazard of death may be dependent on random effects from various levels. To simplify the estimation procedure, we adopt the Gaussian quadrature technique with a piecewise log‐linear baseline hazard for the death process, which can be conveniently implemented in the freely available software aML. As an example, we analyze repeated measures of hematocrit level and survival for end stage renal disease patients clustered within a randomly selected 126 dialysis centers in the U.S. renal data system data set. Our model is very comprehensive yet easy to implement, making it appealing to general statistical practitioners. Copyright © 2008 John Wiley & Sons, Ltd.
Statistical performance of cladistic strategies for haplotype grouping in pharmacogenetics
Authors: Lunceford Jared K. , Liu Nancy 
Published: August 2008

AbstractHaplotypes comprising multiple single nucleotide polymorphisms (SNPs) are popular covariates for capturing the key genetic variation present over a region of interest in the DNA sequence. Although haplotypes can provide a clearer assessment of genetic variation in a region than their component SNPs considered individually, the multi‐allelic nature of haplotypes increases the complexity of the statistical models intended to discover association with outcomes of interest. Cladistic methods cluster haplotypes according to the estimates of their genealogical closeness and have been proposed recently as strategies for reducing model complexity and increasing power. Two examples are methods based on a haplotype nesting algorithm described by Templeton et al. (Genetics 1987; 117:343–351) and hierarchical clustering of haplotypes as described by Durrant et al. (Am. J. Hum. Genet. 2004; 75:35–43). In the context of assessing the pharmacogenetic effects of candidate genes, for which high‐density SNP data have been gathered, we have conducted a simulation‐based case study of the testing and estimation properties of two strategies based on Templeton's algorithm (TA), one being that described by Seltman et al. (Am. J. Hum. Genet. 2001; 68:1250–1263; Genet. Epidemiol. 2003; 25:48–58), as well as the method of Durrant et al. using data from a diabetes clinical trial. Even after adjusting for multiplicity, improvements in power can be realized using cladistic approaches with treatment group sizes in the range expected for standard trials, although these gains may be sensitive to the cladistic structure used. Differences in the relative performance of the cladistic approaches examined were observed with the clustering approach of Durrant et al. showing statistical properties superior to the methods based on TA. Copyright © 2008 John Wiley & Sons, Ltd.