bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance targets and the Brier score
Authors: Roulston Mark S.
Published: August 2007

The Brier score and Brier skill score are commonly used measures for evaluating probability forecasts. An oft‐cited desirable property of these measures is that they are strictly proper, meaning that forecasters wishing to optimise the expected value of these measures should report their true beliefs and not ‘hedge’ the forecast by reporting probabilities that differ from their true beliefs. In this article, it is argued that the propriety of the Brier score only discourages hedging if the utility of the forecaster is a linear function of the score. In particular, it is demonstrated, that if known performance targets based on the score are imposed on the forecaster then this negates the propriety of the score. Forecasters wishing to maximise the probability of achieving the target value of the Brier score or Brier skill score should hedge their forecasts rather than report their true beliefs. In contrast, performance targets drawn from a uniform distribution which are unknown to the forecaster during the evaluation period will induce the utility function of the forecaster to be a linear function of the Brier score. This preserves the propriety of the scoring rule. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
A novel algorithm for automatic tropical cyclone eye fix using Doppler radar data
Authors: Wong Ka Yan , Yip Chi Lap , Li Ping Wah
Published: August 2007

Tropical cyclone (TC) is among the most destructive of weather phenomena. A key element in issuing early TC warnings is an accurate and timely knowledge of the location of the circulation centre, or ‘eye’, of the TC. However, TC radar eye fix is often carried out manually in practice, and results may vary among forecasters. In this paper, a novel motion field structure analysis method is described as an aid to locate TC eyes more accurately. The method is comprehensive, and can handle incomplete data and landfalling cases. Implemented on a standard desktop computer, an average error of 0.15 degrees in latitude/longitude on a Mercator Projection map for TCs that are completely inside the radar image is obtained. This is well within the relative errors given by different TC warning centres. The method provides an independent and objective source of information to assist forecasters to fix the TC centre. Copyright © 2007 Royal Meteorological Society
Weather and cycling—a first approach to the effects of weather conditions on cycling
Authors: Brandenburg Christiane , Matzarakis Andreas , Arnberger Arne
Published: August 2007

In urban and suburban recreation areas, walking and cycling constitute an important part of leisure activities. Both activities involving motion, are not only carried out for recreation but also for commuting to and from work. The mixture of recreation and commuting cycling is a challenge for park management. Conflicts between user groups, such as walkers and cyclists, exist due to the different movement speeds and also different user profiles: walkers, leisure cyclists and cyclists who commute have distinctive degrees of acceptance towards other user groups. Another challenge for park management is the damage caused by the bicycles. There is damage to the surface of gravel trails due to the frequency of use and there is damage to the vegetation next to the trails as a result of evasive manoeuvres by the cyclists. Paved trails are preferred by cyclists as this results in increased speed.

Important issues associated with park management are: degradation of the soil surface in general, and trails in particular, as well as conflicts between different recreational users, such as walkers and cyclists caused by their different user profiles including different speeds and acceptance of social carrying capacities.

To shed some light on bicycling activities in Vienna, an analysis of the pattern of the temporal use of daily frequency of recreational and commuting cyclists was carried out, taking weather conditions into consideration. The results show that, principally, cycling is an activity performed during fine weather. This is especially the case for recreational use. Fine weather is interpreted as generally sunny weather with an ambient temperature of more than 5 °C, few clouds and no precipitation for a period of 1 year. In this study, the temperature, precipitation and cloud cover, as well as the thermal index ‘physiologically equivalent temperature’ (PET), were used as parameters to describe more precisely the dependence of both cyclist groups on the local weather conditions. Copyright © 2007 Royal Meteorological Society
Spatial distribution of climatic indices in northern Greece
Authors: Baltas E.
Published: August 2007

Results of research work concerning the spatial estimation of precipitation and air temperature and the representation of different climatic indices, which assess the climate of a region in northern Greece, are reported. The climatic indices used were the Johansson Continentality Index, the Kerner Oceanity Index, the De Martonne Aridity Index and the Pinna Combinative Index. Data from 15 meteorological stations located in northern Greece during the period 1965–1995 were analysed and processed on a monthly basis and graphs of precipitation and temperature were constructed for use in agricultural applications. Köppen's classification was also investigated for the 15 stations. GIS interpolation techniques, such as the inverse distance weighted (IDW) function, were used for the areal estimation of the above mentioned parameters in northern Greece and an evaluation of the climate indices was made, based on the results. Copyright © 2007 Royal Meteorological Society
Prediction of occurrence and quantity of daily summer monsoon precipitation over Orissa (India)
Authors: Mohanty U. C. , Mohapatra M.
Published: August 2007

The precipitation over Orissa State, a meteorological subdivision on the east coast of India, shows large‐scale spatio‐temporal variation caused by the interaction of the basic monsoon flow with the monsoon disturbances over the Bay of Bengal and the orography owing to the Eastern Ghats and other hill peaks in Orissa and its neighbourhood. Hence, it is difficult to predict daily precipitation over Orissa. The objective of this study is to predict the occurrence and quantity of precipitation 24 h ahead, over specific locations of Orissa during the summer monsoon season (June‐September). For this purpose, a probability of precipitation (PoP) model has been developed by applying stepwise regression with the available surface and upper air parameters from synoptic and radiosonde and radio wind stations in and around Orissa as potential predictors. The parameters selected through stepwise regression for the PoP model have been used to develop a probabilistic model for a Quantitative Precipitation Forecast (QPF) in different ranges, such as 0.1–10, 11–25, 26–50, 51–100 and > 100 mm, using Multiple Discriminant Analysis (MDA). Both the PoP and QPF models have been developed based on data from 1980 to 1994 and verified with the data from 1995 to 1998.

Considering six representative stations for six homogeneous regions in Orissa, the PoP model performs very well with percentages of correct forecast for occurrence/non‐occurrence of precipitation being about 73 and 65% respectively for developmental and independent data. However, the skill score of the MDA model for categorical forecast is poor, especially for higher values of precipitation. Copyright © 2007 Royal Meteorological Society
Cold environmental stress induces detrusor overactivity via resiniferatoxin‐sensitive nerves in conscious rats
Authors: Imamura Tetsuya , Ishizuka Osamu , Aizawa Naoki , Zhong Chen , Ogawa Teruyuki , Nakayama Tsuyoshi , Tanabe Tomoaki , Nishizawa Osamu
Published: August 2007

Aims

We determined if cold environmental stress induced detrusor overactivity in conscious rats. We then examined the role of resiniferatoxin (RTX)‐sensitive nerves in this response.

Methods

Three days prior to cystometric investigation, the urinary bladders of 12 female rats were cannulated. Six of the rats were treated with RTX 24 hr prior to cystometric investigation. The rats were exposed to three ambient temperature conditions: room temperature (RT, 27°C) for 20 min, low temperature (LT, 4°C) for 40 min, and RT again for 20 min. During each exposure, cystometric patterns of the rats were recorded. Additionally, neuronal structures of urinary bladders were visualized by immunohistochemistry.

Results

When the conscious rats were suddenly transferred from RT to LT, the cooled rats exhibited micturition patterns of detrusor overactivity. After 20 min at LT, the response slowly improved. After returning to RT, the overactive detrusor response disappeared, reverting to patterns similar to those before transfer to LT. When the RTX‐treated rats were exposed with cold stress, they also exhibited detrusor overactivity. However, it was significantly mitigated compared to the non‐RTX‐treated normal rats. The normal rats had distinct neuronal structures labeled with S100 and calcitonin gene‐related peptide antibodies in the urinary bladders, but the RTX‐treated rats had few.

Conclusion

Detrusor overactivity of the conscious rats was induced by cold environmental stress. A portion of the cold‐stress detrusor overactivity might be mediated by RTX‐sensitive neurological pathway. The cold‐stress model would be useful to investigate lower urinary tract functions. Neurourol. Urodynam. 27:348–352, 2008. © 2007 Wiley‐Liss, Inc.
A numerical method for one‐dimensional nonlinear Sine‐Gordon equation using collocation and radial basis functions
Authors: Dehghan M. , Shokri Ali
Published: August 2007

In this article, we propose a numerical scheme to solve the one‐dimensional undamped Sine‐Gordon equation using collocation points and approximating the solution using Thin Plate Splines (TPS) radial basis function (RBF). The scheme works in a similar fashion as finite difference methods. The results of numerical experiments are presented and are compared with analytical solutions to confirm the good accuracy of the presented scheme.© 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
CFD‐based risk assessment for hydrogen applications
Authors: Hansen Olav R. , Middha Prankul
Published: August 2007

Computational fluid dynamics calculations for gas explosion safety have been widely used for doing risk assessments within the oil and gas industry for more than a decade. On the basis of predicted consequences of a range of potential accident scenarios a risk level is predicted. The development of applications using hydrogen as a clean energy carrier has accelerated in recent years, and hydrogen may be used widely in the future. Because of the very high reactivity of hydrogen, safe handling is critical. For most applications it is not realistic to perform an extensive risk assessment similar to what is done for large petrochemical installations. On the other hand, simplified methods, like venting guidelines, may have a questionable validity for hydrogen. The use of simple methods, if these actually are conservative, will in general predict too high consequences for the majority of scenarios, as these are not able to represent actual geometry and physics of the explosion.

In this article a three‐step approach is proposed. The initial approach will be to carry out a “worst‐case” calculation evaluating the consequences if a full stoichiometric gas cloud is ignited. Mitigation measures can also be considered. As a second step, if potential consequences of the initial approach are not acceptable, the assumptions are refined and more calculations are performed to make the evaluations more realistic and reduce unnecessary conservatism of the chosen worst‐case scenarios. Typically a number of dispersion calculations will be performed to generate likely gas clouds, which are subsequently ignited. If estimated consequences are still not acceptable, a more comprehensive study, including ventilation, dispersion, and explosion, is performed to evaluate the probability for unacceptable events. © 2007 American Institute of Chemical Engineers Process Saf Prog 2007
Safety instrument system manuals—a need to balance reliability and safety
Authors: Thomas Harold W. , Deibert David , Arner David C. , Weir David
Published: August 2007

With the recently approved IEC 61511 and ANSI/ISA‐84.00.01 standards, process industry companies are being challenged to determine the level of performance required from their safety instrumented functions (SIF) and to verify that the design, installation, operation, and maintenance employed is sufficient to ensure that the required performance is sustained until the SIF is decommissioned. As a practical matter, user companies must self‐certify or user approve their SIF equipment, since they are responsible for the correct operation of the SIF in the operating environment, not just individual components as manufactured. To accomplish this, user companies need lifecycle assistance from equipment manufacturers, irrespective of hardware or software certification status related to IEC 61508. One of the best means to communicate the necessary information is via a safety manual for those involved in instrument system design installation and operation. IEC 61508 requires that equipment manufacturers provide a safety manual with any product claimed to comply with IEC 61508. Although required for product certification, it is the authors' current experience that quality and consistency in safety manuals is lacking. Part of this is due to IEC 61508 not providing a clear concise template with minimum requirements. The safety manual requirements are scattered throughout the rather complex standard. This article seeks to provide a user's perspective of what essential information is needed from equipment manufacturers to not only comply with IEC 61508, but also to provide enough information to the user of the product to allow the essential balance of reliability and safety in both SIF and instrumented protective function applications. © 2007 American Institute of Chemical Engineers Process Saf Prog 2007
Positron annihilation studies in plastically deformed Fe‐Mn‐Si‐Cr‐Ni‐C
Authors: De Baerdemaeker J. , Mostafa Khaled M. , Van Caenegem N. , Segers D. , Houbaert Y.
Published: August 2007

Fe‐Mn‐Si‐Cr‐Ni‐C samples with deformations from 2 to 20% were investigated using positron annihilation spectroscopy, optical microscopy (OM) and X‐ray diffraction (XRD). Both Doppler broadening of the annihilation radiation (DBAR) and positron annihilation lifetime spectroscopy (PALS) measurements were performed. The DBAR experiments, carried out using a slow positron beam, indicate a sudden increase in the defect concentration in between 4 and 6% deformation. This is confirmed by the lifetime measurements. In between 6% and 8% deformation the lineshape parameter significantly changes which coincides with the drastic increase of the concentration of the martensite phase as confirmed by XRD. Positron annihilation spectroscopy indirectly probe the γ/ε martensitic phase transformation by probing correlated dislocations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of swift heavy ion‐induced defects in Fe‐Rh alloy by using positron beam technique
Authors: Hori Fuminobu , Fukuzumi Masafumi , Kawasuso Atsuo , Zushi Yoshihiro , Chimi Yasuhiro , Ishikawa Norito , Iwase Akihiro
Published: August 2007

Recently, we have found that 100–200 MeV heavy ion irradiation induces ferromagnetic state in B2 type Fe‐50at.%Rh intermetallic alloy below antiferromagnetic‐ferromagnetic transition temperature of unirradiated alloy. In order to characterize the lattice defects induced by swift heavy ion irradiation, we performed Doppler‐broadening experiments for unirradiated Fe‐Rh alloy and that irradiated with 200 MeV 136Xe ions by using a slow positron beam. The S‐parameter increases gradually with increasing the ion‐fluence up to 5 x 1012 ions.cm–2. Above 5 x 1012 ions.cm–2, the rate of S‐parameter increase is slowly saturated. From the dependence of S‐parameter on ion‐fluence, we have calculated the concentration of vacancy‐type defects surviving in the specimen, which is much smaller than that estimated by TRIM‐code. The result implies that anti‐site type defects dominantly remain in the irradiated specimen, which stabilize the ferromagnetic state in Fe‐50at.%Rh alloy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron annihilation in structural vacancies in Al‐rich NiAl alloys
Authors: Morales A. L. , Leon L. A. , Raigoza N. , Duque C. A. , Kuriplach J. , Hou M.
Published: August 2007

Positron annihilation in structural vacancies in B 2 Al‐rich NiAl alloys is studied theoretically. For this purpose we use the atomic superposition method combined with molecular dynamics employed for relaxations of random vacancy configurations. We found that the defect lifetime decreases with the increasing Ni vacancy concentration. Calculated positron lifetimes are discussed in terms of the ‘vacancy‐superstructure' effect and compared with experimental positron lifetime data available. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal formation of vacancies in Cu3Sn
Authors: Shishido I. , Yasueda H. , Mizuno M. , Araki H. , Shirai Y.
Published: August 2007

The formation of thermal vacancies in Cu3Sn has been investigated by using positron annihilation lifetime spectroscopy. Positron lifetime measurement was performed in‐situ between 293 K and 673 K. The positron lifetime below 433 K was found to be about 140 ps, which indicates that there are no detectable vacancies below 433 K. A sharp increase of the mean positron lifetime τm, which is due to thermal vacancy formation, starts around 453 K and the saturation trapping of positrons by thermal vacancies are observed above 633 K. The Arrhenius plot of the positron trapping rate, which is proportional to the vacancy concentration, represents a linear behavior and the vacancy formation enthalpy was determined to be 0.63±0.02 eV. This value is relatively low comparing with that expected from the melting temperature (950 K) of this alloy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Composition influence on positron annihilation parameters in ZnO‐based nanocrystal semiconductor powders
Authors: Damonte L. C. , Hernández Fenollosa M. A. , Donderis V. , Marí B.
Published: August 2007

Zn1–xMgxO powders at various compositions were obtained by mechanical milling from the binary oxides. The progressive incorporation of Mg atoms into the ZnO lattice was monitored by X‐ray diffraction (XRD). The evolution of annihilation parameters with milling time and composition were analyzed and related to the possible types of mechanical and substitutional induced defect present. It was concluded that the average lifetime constitute a useful parameter to sense the complete cation substitution in the wurtzite structure. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanocrystalline alloys studied by positron annihilation lifetime spectroscopy
Authors: Petriska Martin , Pavúk Milan , Slugeň Vladimír , Kršjak Vladimír , Miglierini Marcel
Published: August 2007

Nanocrystalline alloys present a new class of materials that exhibit interesting magnetic properties. These stem primarily from the presence of crystalline grains with the size of several tens of nanometers embedded in a residual amorphous matrix. In this paper, we employ positron annihilation spectrometry to investigate the relation between positron lifetime and microstructure of the NANOPERM‐type metallic Fe76Mo8Cu1B15 alloy. The behaviour of positron lifetime with respect to the annealing temperature is discussed for samples, which were prepared by one hour thermal treatment in a vacuum at temperatures ranging from 330 up to 700 °C. Samples in amorphous (as‐quenched) state were analysed, too. The results of this work confirm that the optimum annealing temperature of 550 °C correlates with the minimum of free volume and coincide with the temperature at which superior magnetic properties are observed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron annihilation spectroscopic study of hydrothermal grown n‐type zinc oxide single crystal
Authors: Hui C. W. , Zhang Z. D. , Zhou T. J. , Ling C. C. , Beling C. D. , Fung S. , Brauer G. , Anwand W. , Skorupa W.
Published: August 2007

Positron lifetime and coincidence Doppler broadening spectroscopic (CDBS) measurements were carried out to study the defects in two hydrothermal (HT) grown ZnO single crystal samples (HT1 and HT2) obtained from two companies. Single component model could offer good fittings to the room temperature spectra of HT1 and HT2, with the positron lifetimes equal to 199 ps and 181 ps respectively. These two lifetime components were associated with saturated positron trapping into two VZn‐related defects with different microstructures. The positron lifetimes of HT1 was found to be temperature independent. For the HT2 sample, the positron lifetime remained unchanged with T > 200 K and decreased with decreasing temperature as T<200K. This could be explained by the presence of an additional positron trap having similar electronic environment to that of the delocalized state and competing in trapping positrons with the 181 ps component at low temperatures. Positron‐electron autocorrelation function, which was the fingerprint of the annihilation site, was extracted from the CDBS spectrum. The obtained autocorrelation functions of HT1 and HT2 at room temperature, and HT2 at 50 K had features consistent with the above postulates that the 181 ps and the 199 ps components had distinct microstructures and the low temperature positron trap existed in HT2. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of cuprous oxide using time of flight positron annihilation induced Auger electron spectroscopy
Authors: Nadesalingam M. P. , Mukherjee S. , Somasundaram S. , Chenthamarakshan C. R. , De Tacconi Norma R. , Davis B. , Rajeshwar K. , Weiss A. H.
Published: August 2007

Changes in the surface of copper (I) oxide resulting from vacuum annealing and reoxidation after vacuum annealing have been investigated using positron annihilation induced Auger electron spectroscopy (PAES). The PAES measurement shows a large monotonic increase in the intensity of the annihilation induced Cu (M2,3 VV) Auger peak as the sample is subjected to thermal anneal in the vacuum at 300 °C temperature for 13 minutes. Exposure of the vacuum annealed surface to oxygen resulted in a large reduction of Cu (M2,3 VV) intensity and an increase in the signal due to the KLL transition in O. These results provide a clear demonstration of the utility of PAES in the study of oxide surfaces. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How many random edges make a dense hypergraph non‐2‐colorable?
Authors: Sudakov Benny , Vondrák Jan
Published: August 2007

We study a model of random uniform hypergraphs, where a random instance is obtained by adding random edges to a large hypergraph of a given density. The research on this model for graphs has been started by Bohman et al. (Random Struct Algorithms 22 (2003) 33–42), and continued in (Bohman et al., Random Struct Algorithms 24 (2004) 105–117) and (Krivelevich et al., Random Struct Algorithms 29 (2006), 180–193). Here we obtain a tight bound on the number of random edges required to ensure non‐2‐colorability. We prove that for anyk‐uniform hypergraph withΩ(nk‐ε) edges, addingω(nkε/2) random edges makes the hypergraph almost surely non‐2‐colorable. This is essentially tight, since there is a 2‐colorable hypergraph withΩ(nk‐ε) edges which almost surely remains 2‐colorable even after addingo(nkε/2) random edges.© 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Bootstrapping for confidence interval estimation and hypothesis testing for parameters of system dynamics models
Authors: Dogan Gokhan
Published: August 2007

Methods for confidence interval estimation and hypothesis testing used in the literature and implemented in system dynamics software packages typically assume that the data are normally distributed, not autocorrelated and not heteroskedastic. In dynamic models these assumptions are often violated. Here we propose the bootstrapping method for confidence interval estimation and hypothesis testing in system dynamics models and provide an overview of the issues involved in applying bootstrapping properly in dynamic models. Bootstrapping is a widely used and robust method but its use in system dynamics models is rare. Bootstrapping can handle violations of the maintained assumptions of traditional methods. It is also valid for small samples whereas traditional methods are valid only asymptotically. Another advantage of bootstrapping is that it is a convenient tool for testing hypotheses including complicated functions of parameters (e.g., multiplication, division of parameters). We provide two examples for illustration, one in discrete time and one in continuous time, including experimental data from the beer distribution game and field data from a study of service quality in the banking industry. Copyright © 2007 John Wiley & Sons, Ltd.
System dynamics projects that failed to make an impact
Authors: Größler Andreas
Published: August 2007

The purpose of this paper is to discuss the phenomenon of why some system dynamics projects fail to generate substantial impact in organizations—despite the fact that they are based on an apparently valid system dynamics model and are conducted by experts in the field. The approach followed in the paper is a conceptual discussion, extended by two short case studies. Findings are that the quality of the model and the expertise of the modeler are necessary but not sufficient requirements for organizational impact. Further research should concentrate on the detailed analysis of additional requirements. Practical implications are an increased embedding of system dynamics projects in organizational intervention architectures. The originality of the paper lies in its focus and discussion of failed projects that are invaluable sources for insight generation. Copyright © 2007 John Wiley & Sons, Ltd.
Hepatoprotective efficacy of certain flavonoids against microcystin induced toxicity in mice
Authors: Jayaraj R. , Deb Utsab , Bhaskar A. S. B. , Prasad G. B. K. S. , Rao P. V. Lakshmana
Published: August 2007

Toxic cyanobacteria (blue‐green algae) water blooms have become a serious problem in several industrialized areas of the world. Microcystin‐LR (MC‐LR) is a cyanobacterial heptapeptide that represents acute and chronic hazards to animal and human health. Identification of suitable chemprotectants against microcystin is essential considering human health hazards. In the present study, we have evaluated the protective efficacy of three flavanoids namely quercetin (200 mg/kg), silybin (400 mg/kg), and morin (400 mg/kg)] pretreatment against microcystin toxicity (0.75 LD50, 57.5 μg/kg) in mice. Various biochemical variables were measured to study the recovery profile of protected animals at 1‐ and 3‐days post‐toxin treatment. The serum alanine amino transferase (ALT) shows 17‐fold increase in MC‐LR treated animals compared with control group at 1 day. The silybin and quercetin group showed a decrease in level of ALT compared with MC‐LR group but still higher than control group. No significant protection was observed with aspartate aminotransaminase (AST) and lactate dehydrogenase (LDH) levels in flavanoid‐treated groups at 1‐day post‐treatment. But at 3 days, the serum levels of AST and ALT were normalized to control values, but the serum LDH levels were still significantly higher than the control group. No significant changes were observed in glutathione peroxidase and reduced glutathione levels at both 1‐ and 3‐day postexposure. The catalase activity shows a significant decrease in quercetin‐treated animals at 3‐day postexposure. The protein phosphatase was significantly inhibited in MC‐LR group compared to control. The silybin pretreated group showed recovery after 1 day. At 3 days, the PPAse activity was reversed to control values in all the flavanoid‐treated groups. Immunoblotting analysis showed microcystin‐PPAse adduct in liver tissues of toxin‐treated as well as flavanoid‐treated mice even after 3 days. The results of this study show that flavanoids, quercetin, silybin, and morin could reverse the hepatotoxic effects of MC‐LRin vivo. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 472–479, 2007.
Effects of aqueous extracts from five species of the family Papaveraceae on selected aquatic organisms
Authors: Jančula Daniel , Suchomelová Jana , Gregor Jakub , Smutná Marie , Maršálek Blahoslav , Táborská Eva
Published: August 2007

The effects of aqueous root extracts from five species of the family Papaveraceae on the growth of cyanobacteria, algae, and other non‐target aquatic organisms were investigated to evaluate their potential use as algicides or cyanocides in the aquatic environment. Dicranostigma lactucoides and Sanguinaria canadensis featured the highest toxicity while Macleaya microcarpa was found to be the least toxic to all aquatic organisms tested. The Chelidonium majus extract had the best properties as a potential algicide or cyanocide because of its significant toxicity to phytoplankton and lower toxicity to non‐target aquatic organisms as compared with the other Papaveraceae family members. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 480–486, 2007.
Biomonitoring of heavy metals using Mytilus galloprovincialis in Safi coastal waters, Morocco
Authors: Maanan Mohamed
Published: August 2007

Heavy metal concentrations of mercury, cadmium, lead, zinc, cooper, nickel, manganese, and chromium in Mytilus galloprovincialis were investigated to provide information on pollution of Safi coastal area, since these metals have the highest toxic potential. The concentration of Hg and Pb was determined by AFS and ICP‐MS methods, respectively, whilst the remaining metals (Cd, Cr, Cu, Mn, Zn, and Ni) were quantified by AAS. High lead, cadmium, chromium, and mercury levels were registered in tissue samples collected from two stations near the Jorf Lihoudi and Safi city, while elevated concentration of manganese and zinc (14.70–25.30 mg kg−1 and 570–650 mg kg−1 dry wt, respectively) were found in mussel specimens from Cap Cantin. The high levels of nickel found respectively in the areas near the industrial area being of concern in terms of environmental health need frequent monitoring. The metal concentrations recorded at the clean stations may be considered as useful background levels to which to refer for comparison within the Atlantic coast. M. galloprovincialis are suitable biomonitors to investigate the contamination levels of heavy metals pollution face a different human activity in this coastal area of the Atlantic coast. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 525–531, 2007.
Toxicological effects and bioaccumulation in the freshwater clam (Corbicula fluminea) following exposure to trivalent arsenic
Authors: Santos H. M. , Diniz M. S. , Costa P. M. , Peres I. , Costa M. H. , Alves S. , Capelo J. L.
Published: August 2007

Contamination of aquatic environments by arsenic is a serious worldwide problem. The main objective of this work was to evaluate the response of a freshwater clam (Corbicula fluminea) to arsenic (As III) exposure and infer its potential as a biological indicator of contamination. Metallothioneins (MTs) were used as indicators of metalloid toxicity in combination with an histological and histochemical evaluation. After a period of acclimatization in the laboratory, 50 C. fluminea (0.4 g ± 0.1) were exposed to different nominal concentrations of arsenic (100, 300, 500, and 1000 μg L−1) for 7 days. The concentration of total As III in the water and in the tissues of the organisms was determined by atomic absorption spectrometry, and MTs were quantified through differential pulse polarography. Results suggest that the organisms exposed to the concentrations of 300 and 1000 μg As L−1 accumulated the highest levels of As III in the tissues (17 ± 9 and 15 ± 3 μg g−1 distilled water, respectively), which was confirmed through histochemical analysis. An apparent induction of MTs was also observed in the organisms exposed to As III, suggesting that C. fluminea possesses some capacity for arsenic regulation. The results suggest that the induction of MTs may be of high interest as a biomarker for arsenic contamination in aquatic environments, and confirms the potential of C. fluminea as a biological indicator. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 502–509, 2007.
Is relative abundance a good indicator of population size? Evidence from fragmented populations of a specialist butterfly (Lepidoptera: Lycaenidae)
Authors: Collier Neil , Mackay Duncan A. , Benkendorff Kirsten
Published: August 2007

A common task for conservation biologists and ecologists is to establish how many individuals there are in a population, usually within a defined area of habitat. Estimates of both absolute and relative population sizes are widely used in many aspects of population conservation and management. Mark–recapture studies are appropriate for estimating the absolute population sizes of a wide range of animals, in both open and closed populations, while relative abundances can be estimated from a variety of survey methods. Relative abundances are often used in a comparative way to compare both population size and fluctuations in abundance. Here, we used transect counts and capture–recapture studies to estimate the relative abundances and population sizes of a specialist butterfly, Theclinesthes albocincta (Lycaenidae) in three habitat fragments, over two consecutive years. The sizes of the three populations differed significantly between sites and were highly variable between years. One population was extremely small and is likely to become locally extinct. We found that estimates of relative abundance were highly correlated with estimates of population size (r2 = 0.88, P = 0.017) derived from the open population models. The combination of transect counts and capture–recapture studies used in this study appears to be a very informative tool for the conservation and management of this butterfly species and could be extended to other insects.
Quality performance of newborn screening systems: Strategies for improvement
Authors: Webster D.
Published: August 2007

Newborn metabolic screening is a public health activity with the potential to realize significant health gains for infants affected with a range of congenital conditions. Many of these are inborn errors of metabolism. The activities required to achieve the gains are diverse and carried out by a number of organizations, by families and by many health care professionals. Laboratories have the best‐developed quality strategies, which include quality assurance programmes, guidelines, protocols and standards. Two‐tier testing and use of multiple markers improve sensitivity and specificity. There are international initiatives to harmonize assay materials and definitions to allow better benchmarking between programmes. Outside the laboratory, standards, education and protocols improve the quality of specimen collection, diagnosis and treatment, which together produce the health gains.
Separation and Quantification of Vegetable Oil Based Polyols by High Performance Liquid Chromatography with Evaporative Light Scattering Detection
Authors: Yue Jin , Narine Suresh S.
Published: August 2007

Polyols with terminal primary alcohol functionalities were obtained from canola oil via an ozonolysis and hydrogenation process. A high performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was developed for separating and quantifying the polyol products. Linear calibration curves were obtained for the mono‐ol, diol and triol components with correlations (r2) above 0.98. According to the standard curve, the content of mono‐ol, diol and triol can be obtained from their HPLC‐ELSD chromatograms.
Does Soil Salinity Affect Yield and Composition of Cottonseed Oil?
Authors: Ahmad Sajjad , Anwar Farooq , Hussain Abdullah Ijaz , Ashraf Muhammad , Awan Abdul Rasul
Published: August 2007

Variation in the yield and composition of oil of cotton (Gossypium hirsutum) seed collected from two different sites (saline and non‐saline) of Pakistan was examined. Hexane‐extracted oil content of cottonseed from saline and non‐saline areas was found to be 17.7 and 18.6%, respectively. No significant (P > 0.05) differences in the refractive index (40 °C), color, specific gravity (24 °C), iodine, free fatty acid, peroxide, unsaponifiable matter, saponification, conjugated diene and triene and p‐anisidine values of the oils of cotton plants from saline and non‐saline habitats were observed. Fatty acid compositional analysis showed the concentration of stearic (C18:0) and oleic (C18:1) acids to be significantly (P ≤ 0.05) higher, whereas that of linoleic (C18:2) acid was lower in cottonseed oils from the saline area than those from the non‐saline habitat. Tocopherol contents of cottonseed oils were significantly (P ≤ 0.05) higher from the saline area than those from the non‐saline area. The results of the present study showed that soil salinity did not affect the oil yield of cottonseed, however, it significantly (P ≤ 0.05) affected the tocopherol and fatty acid profiles of the oils examined.
Prognostic importance of plasma NT‐pro BNP in chronic heart failure in patients treated with a β‐blocker: Results from the Carvedilol Or Metoprolol European Trial (COMET) trial
Authors: Olsson Lars G. , Swedberg Karl , Cleland John G.F. , Spark Phillip A. , Komajda Michel , Metra Marco , Torp‐Pedersen Christian , Remme Willem J. , Scherhag Armin , Poole‐Wilson Philip ,   COMET investigators
Published: August 2007

Background

Plasma levels of N‐terminal pro‐brain natriuretic peptide (NT‐pro BNP) are increased in patients with chronic heart failure (CHF). Beta‐blockers (BB) may influence these levels but it is unclear whether changes in NT‐pro BNP reflect concomitant changes in prognosis.

Objectives

To assess the prognostic importance of NT‐pro BNP at baseline and during follow‐up, in patients in whom beta‐blocker therapy is initiated.

Methods

In COMET, 3029 patients with CHF in NYHA class II–IV and EF<35% were randomised to carvedilol or metoprolol tartrate and were followed for an average of 58 months. Blood samples were collected for the measurement of NT‐pro BNP at baseline (n=1559) and during follow‐up (n=309).

Results

Baseline plasma concentrations of NT‐pro BNP above the median (1242 pg/ml) were associated with higher all‐cause mortality (RR 2.77; 95% CI 2.33–3.3, p<0.001). Patients who achieved NT‐pro BNP levels <400 pg/ml during follow‐up had a lower subsequent mortality (RR 0.32; 95% CI 0.15–0.69, p=0.004).

Conclusions

The plasma concentration of NT‐pro BNP is a powerful predictor of mortality in patients with CHF. Patients who achieve an NT‐pro BNP of <400 pg/ml subsequent to treatment with a beta‐blocker have a favourable prognosis.
Rose, Orange, and Tulip: The failed post-Soviet revolutions
Authors: Tudoroiu Theodor
Published: August 2007

In 2003–2005, democratic revolutions overthrew the Georgian, Ukrainian, and Kyrgyz post-Soviet authoritarian regimes. However, disillusioned citizens witness today their new leaders creating a Bonapartist regime, entering into open conflict with former revolutionary allies or being forced to accept cohabitation with leaders of the previous regime. This article argues that despite internationally acclaimed civic mobilisation, civil society's weakness seriously affected the three revolutionary processes. These were in fact initiated, led, controlled, and finally subordinated by former members of the authoritarian regimes' political elite. Finally, the supposedly democratic revolutions proved to be little more than a limited rotation of ruling elites within undemocratic political systems.
Social shock in transforming Central and Eastern Europe
Authors: Berend Ivan T.
Published: August 2007

Central and Eastern European societies, in spite of significant successes of transformation, are in a social shock. Economic hardship, unemployment, lower income and even poverty for many, and social polarization played a role in disappointment. The main reason of social shock, however, was cultural, the sharp collision of state socialist, and traditional values on the one hand and new values and social behavioral requirements on the other. The doors opened widely, but most of the people were frightened to enter into an unknown world. Social-behavioral changes are generations-long processes.
Co-ingestion of leucine with protein does not further augment post-exercise muscle protein synthesis rates in elderly men
Authors: Koopman René , Verdijk Lex B. , Beelen Milou , Gorselink Marchel , Kruseman Arie Nieuwenhuijzen , Wagenmakers Anton J. M. , Kuipers Harm , van Loon Luc J.C.
Published: August 2007

Leucine has been suggested to have the potential to modulate muscle protein metabolism by increasing muscle protein synthesis. The objective of this study was to investigate the surplus value of the co-ingestion of free leucine with protein hydrolysate and carbohydrate following physical activity in elderly men. Eight elderly men (mean age 73 ± 1 years) were randomly assigned to two cross-over treatments consuming either carbohydrate and protein hydrolysate (CHO+PRO) or carbohydrate, protein hydrolysate with additional leucine (CHO+PRO+leu) after performing 30 min of standardized physical activity. Primed, continuous infusions withl-[ring-13C6]phenylalanine andl-[ring-2H2]tyrosine were applied, and blood and muscle samples were collected to assess whole-body protein turnover as well as protein fractional synthetic rate in thevastus lateralismuscle over a 6 h period. Whole-body protein breakdown and synthesis rates were not different between treatments. Phenylalanine oxidation rates were significantly lower in the CHO+PRO+leuv. CHO+PRO treatment. As a result, whole-body protein balance was significantly greater in the CHO+PRO+leu compared to the CHO+PRO treatment (23·8 (sem0·3)v. 23·2 (sem0·3) μmol/kg per h, respectively;P < 0·05). Mixed muscle fractional synthetic rate averaged 0·081 (sem0·003) and 0·082 (sem0·006) %/h in the CHO+PRO+leu and CHO+PRO treatment, respectively (NS). Co-ingestion of leucine with carbohydrate and protein following physical activity does not further elevate muscle protein fractional synthetic rate in elderly men when ample protein is ingested.
Growth and breakdown of low-speed streaks leading to wall turbulence
Authors: ASAI MASAHITO , KONISHI YASUFUMI , OIZUMI YUKI , NISHIOKA MICHIO
Published: August 2007

Two-dimensional local wall suction is applied to a fully developed turbulent boundary layer such that near-wall turbulence structures are completely sucked out, but most of the turbulent vortices in the original outer layer can survive the suction and cause the resulting laminar flow to undergo re-transition. This enables us to observe and clarify the whole process by which the suction-surviving strong vortical motions give rise to near-wall low-speed streaks and eventually generate wall turbulence. Hot-wire and particle image velocimetry (PIV) measurements show that low-frequency velocity fluctuations, which are markedly suppressed near the wall by the local wall suction, soon start to grow downstream of the suction. The growth of low-frequency fluctuations is algebraic. This characterizes the streak growth caused by the suction-surviving turbulent vortices. The low-speed streaks obtain almost the same spanwise spacing as that of the original turbulent boundary layer without the suction even in the initial stage of the streak development. This indicates that the suction-surviving turbulent vortices are efficient in exciting the necessary ingredients for the wall turbulence, namely, low-speed streaks of the correct scale. After attaining near-saturation, the low-speed streaks soon undergo sinuous instability to lead to re-transition. Flow visualization shows that the streak instability and its subsequent breakdown occur at random in space and time in spite of the spanwise arrangement of streaks being almost periodic. Even under the high-intensity turbulence conditions, the sinuous instability amplifies disturbances of almost the same wavelength as predicted from the linear stability theory, though the actual growth is in the form of a wave packet with not more than two waves. It should be emphasized that the mean velocity develops the log-law profile as the streak breakdown proceeds. The transient growth and eventual breakdown of low-speed streaks are also discussed in connection with the critical condition for the wall-turbulence generation.
Stratified turbulence forced in rotational and divergent modes
Authors: LINDBORG E. , BRETHOUWER G.
Published: August 2007

We perform numerical box simulations of strongly stratified turbulence. The equations solved are the Boussinesq equations with constant Brunt–Väisälä frequency and forcing either in rotational or divergent modes, or, with another terminology, in vortical or wave modes. In both cases, we observe a forward energy cascade and inertial-range scaling of the horizontal kinetic and potential energy spectra. With forcing in rotational modes, there is approximate equipartition of kinetic energy between rotational and divergent modes in the inertial range. With forcing in divergent modes the results are sensitive to the vertical forcing wavenumber kfv. If kfv is sufficiently large the dynamics is very similar to the dynamics of the simulations which are forced in rotational modes, with approximate equipartition of kinetic energy in rotational and divergent modes in the inertial range. Frequency spectra of rotational, divergent and potential energy are calculated for individual Fourier modes. Waves are present at low horizontal wavenumbers corresponding to the largest scales in the boxes. In the inertial range, the frequency spectra exhibit no distinctive peaks in the internal wave frequency. In modes for which the vertical wavenumber is considerably larger than the horizontal wavenumber, the frequency spectra of rotational and divergent modes fall on top of each other. The simulation results indicate that the dynamics of rotational and divergent modes develop on the same time scale in stratified turbulence. We discuss the relevance of our results to atmospheric and oceanic dynamics. In particular, we review a number of observational reports indicating that stratified turbulence may be a prevalent dynamic process in the ocean at horizontal scales of the order of 10 or 100 m up to several kilometres.
On the boundary layer structure of differentially heated cavity flow in a stably stratified porous medium
Authors: DANIELS P. G.
Published: August 2007

This paper considers two-dimensional flow generated in a stably stratified porous medium by monotonic differential heating of the upper surface. For a rectangular cavity with thermally insulated sides and a constant-temperature base, the flow near the upper surface in the high-Darcy–Rayleigh-number limit is shown to consist of a double horizontal boundary layer structure with descending motion confined to the vicinity of the colder sidewall. Here there is a vertical boundary layer structure that terminates at a finite depth on the scale of the outer horizontal layer. Below the horizontal boundary layers the motion consists of a series of weak, uniformly stratified counter-rotating convection cells. Asymptotic results are compared with numerical solutions for the cavity flow at finite values of the Darcy–Rayleigh number.