bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations between unemployment and cardiovascular risk factors varies with the unemployment rate: The Cardiovascular Risk Factor Study in Southern Sweden (CRISS)
Authors: Henriksson Karin M. , Lindblad Ulf , Ågren Bo , Nilsson-Ehle Peter , RÅstam Lennart
Published: May 2004

Aims: To investigate associations between CVD risk factors and socio-economic status (SES) in middle-age men during a period of economic changes. Methods: Crossectional surveys at age 37, 40 and 43 in a birth cohort of men in Helsingborg, Sweden. All male residents born 1953 - 4 (n=1460) were invited; participation rates were 68% (n=991) at baseline. Of these enrolled, 78% (n=770) were re-examined after three years and 71% (n=702) again after six years follow-up. Main outcome measures were body mass index (BMI), S-cholesterol, HDL-cholesterol, systolic and diastolic blood pressure (SBP, DBP), smoking and leisure time physical activity (LTPA), education, employment, ethnicity. Results: Baseline unemployment rate was low, n=23 (2.4%), but three and six years later it had increased to 61 (8.2%) and 51 (7.5%) respectively. At baseline, BMI and S-cholesterol were significantly higher in unemployed than in employed men (ΔBMI 1.6 kg/m2, CI: 0.2; 2.9, Δ S-cholesterol 0.6 mmol/L, CI: 0.1; 1.0), and in men with short versus long education (Δ BMI 0.9 kg/m2, CI: 0.4; 1.4, Δ S-cholesterol 0.2 mmol/L, CI: 0.03: 0.4), independent of other SES factors. Over the study period crossectional associations with employment status disappeared for BMI, but remained between short education and BMI. Short education was also associated with a significant increase in BMI (Δ=0.4 kg/m2, CI: 0.1; 0.7) during 6-year follow-up. Conclusions: This study shows that associations between unemployment and CVD risk factors were lost when unemployment rates increased. When the attributable risk of unemployment associated with CVD risk factors is estimated, it is vital to consider the general unemployment rates in society.
Understanding young men's sexual health and prospects for sexual behaviour change in rural Zambia
Authors: Ndubani Phillimon , Bond Virginia , Liljeström Rita , Höjer Bengt
Published: May 2004

Aims: Building on the experiences of an initial study in 1993, the current survey was conducted to enhance understanding of men's sexual health and prospects for behaviour change in Chiawa, rural Zambia. Methods: Seventy-nine randomly selected men in the age range 16 - 25 years were interviewed using a questionnaire. Results: The obstacles to good sexual health reported were: inadequate access to health facilities (35%); unemployment (24%); diseases in general (20%); and HIV/AIDS (17%). Nineteen (24%) had suffered from an STI in the past. Five (13%) of the married and 16 (33%) of the single men had extra or pre-marital relationships at the time of the interviews. In 1993, 50% of the single men had pre-marital relationships. A real man (murume chaiye) was considered to be married, have children, have a job and sexually satisfy his wife; 97% considered themselves to be real men. Some 91% perceived themselves to be at risk of HIV infection; 76 (96%) were aware that HIV could be passed from mother to child, although 51 (61%) would not think about HIV when making decisions about having children. Sixty-eight (86%) believed that condoms could reduce the risk of HIV and 27% used condoms all the time they had sex. In 1993, 6% used condoms all the time they had sex. Conclusions: There are prospects for behaviour change among the men. Prevention messages need to build on what they already know and practise. The messages must aim to change their local sexual norms, which perpetuate risky practices.
Prevention of hip fracture by external hip protectors: an intervention in 17 nursing homes in two municipalities in Norway
Authors: Forsén Lisa , Arstad Christian , Sandvig Sidsel , Schuller Annemarie , Røed Ulf , Søgaard Anne J.
Published: May 2004

Aims: This study was undertaken to estimate the effect of hip protectors on the incidence of hip fracture when introduced into nursing homes as a regular part of the healthcare for all residents. Methods: A pre-test/test design was used. The pre-intervention period lasted 18 months from May 1996. The intervention period lasted 18 months from May 1998. During the intervention period all residents (965 beds) in nursing homes in two municipalities in Norway were offered free use of hip protectors. The project manager provided motivational activities in the nursing homes during the whole period, aimed at increasing the participation rate. Results: The intervention period showed a 39% reduction in the hip fracture incidence when compared with the pre-intervention period (p=0.003). The percentage of daily users of the protector varied from 35% during the first months to 22% at the end of the period. Among the 61 persons who suffered a hip fracture 31 were registered as daily users. Fourteen of the 31 users were not wearing the protector when the hip fracture occurred, while five of the 31 had the protector on their knees. Twelve of the 31 suffered a hip fracture while properly wearing the protector. Conclusions: This non-randomized study showed that hip protectors introduced to all residents in nursing homes considerably reduced the incidence of hip fracture. It may be possible to achieve higher compliance and a further reduction in the incidence of hip fractures if the producers of hip protectors increase the comfort of the protector without reducing its effect. In addition, it is important that health workers encourage more individuals at high risk to use the protector.
The Applicability of Davis Tube Tests to Ore Separation by Drum Magnetic Separators
Authors: Murariu Vasile , Svoboda Jan
Published: May 2004

The current practice of assessing the efficiency of recovery of magnetite and ferrosilicon by drum magnetic separators is to conduct Davis tube tests at a magnetic induction equal to that on the surface of the drum. It is, however, the magnetic force or the force index, and not the magnetic field strength, that are decisive in the operation of a magneticseparator. Since the magneticfield gradients generated by Davis tube and drum magnetic separators are generally different, it is unlikely that the above practice would yield correct information. This article analyses the patterns of the force index generated by drum magnetic separators and a Davis tube operated at different field strengths. It is shown that in order to obtain a correct assessment of the efficiency of separation by a ferrite drum magnetic separator, a Davis tube should be operated at the field of about 0.1 T, which is lower than the current practice suggests. For a rare‐earth drum separator the Davis tube operating field should be at least 0.3 T.
The Processing of Beach Sand from Sri Lanka for the Recovery of Titanium Using Magnetic Separation
Authors: Premaratne W. A. P. J. , Rowson N. A.
Published: May 2004

An investigation has been carried out to study the mineralogical and chemical characteristics of beach sand deposits from Sri Lanka and application and optimisation of different magnetic separators (induced roll magnetic separator and disc magnetic separator) to improve the recovery of titanium from the deposit. Commercial grade titanium concentrates could be achieved employing both induced roll and disc magnetic separators. However, the titanium recovery increased greatly in the magnetic fraction with a titanium content of commercial grade (up to 63.9% TiO2) when paramagnetic titanium‐bearing minerals were separated from beach sand using the disc magnetic separator. The results of the mineralogical and chemical analysis tests for the beach sand deposit indicated that 71% of beach sand was smaller than 355 μm in particle size and more than 99% of titanium content of the deposit was contained in this fraction.
The Effect of Heat Treatment on Chalcopyrite
Authors: Sahyoun C. , Kingman S. W. , Rowson N. A.
Published: May 2004

The influence of conventional heat treatment and microwave radiation on chalcopyrite was investigated. There was a significant increase in the proportion of material recovered to magnetic fraction and magnetic susceptibility with conventional heating time. XRD analysis detected phase changes in conventional heat‐treated chalcopyrite, which increases the magnetic susceptibility of the ore and enables its effective magnetic separation, which is impossible to achieve in its original state.

With microwave treatment, the magnetic susceptibility increases and the proportion of material recovered to magnetic fraction on the induced rolls is also increased. However, XRD analysis failed to detect any phase changes. A possible explanation for this observed behaviour is that the more magnetic component that has been formed by microwave treatment is below the threshold of detection of the XRD analyser. Taking into account that results from the froth flotation tests indicated that % weight fraction in the concentrate decreases with microwave exposure time, the change might be due to a surface effect.
Gravity Separation: Old Technique/New Methods
Authors: Falconer Andrew
Published: May 2004

A comparative review of various types of the main gravity separation devices, both in the recent past and present is presented. The application of each device is discussed in turn, with details of the variables involved and the respective advantages and disadvantages of the separators, together with explanatory diagrams illustrating the processes.
Isoelectric Point Mobility Shift Assay for Rapid Screening of Charged and Uncharged Ligands Bound to Proteins
Authors: Kempná Petra , Cipollone Rita , Villacorta Luis , Ricciarelli Roberta , Zingg Jean‐Marc
Published: May 2004

Three human proteins (hTAP1, hTAP2 and hTAP3) that are related to the yeast phosphatidylinositol/phosphatidylcholine transfer protein SEC14p were recently cloned in our laboratory. These proteins contain a relatively large hydrophobic pocket, the so called CRAL‐TRIO domain, which is present also in other human proteins, such as CRALBP, α‐TTP and MEG2. The CRAL‐TRIO domains in these proteins bind ligands such as retinaldehyde, tocopherols and polyphosphoinositides, respectively. To screen for potential hTAPs ligands, we developed a semi‐quantitative isoelectric point mobility shift assay (IPMS‐assay) that allows assessing the binding of potential hydrophobic ligands to proteins. Purified proteins occupied with a charged ligand migrate differently on isoelectric focusing gels when compared with free protein. Competition of bound charged ligands with uncharged ones reverses the mobility shift, so that the relative affinities of the two ligands to the protein can be estimated. IUBMB Life, 55: 103‐107, 2003
Establishing a global KM initiative: the Wipro story
Authors: Chatzkel Jay
Published: May 2004

Wipro Technologies is an Indian information technology outsourcing company that, over a two year period, established a knowledge management initiative that enables it to build a competitive advantage as it experiences rapid growth in its global market. The Wipro story is remarkable in that it shows that having a sound, innovative knowledge management effort is no longer merely an option but rather a core necessity for any organization anywhere in the world if it is to compete successfully and survive globally. Wipro’s CEO said the knowledge initiative must be based on knowledge sharing and collaboration and this has to be translated into delivering value to the customer, in terms of: speed, being able to deploy for the customer, and innovative products and services which are focused on the customer needs. The knowledge initiative has been implemented across all areas of the firm in all its locations around the world.
Reconfiguring knowledge management – combining intellectual capital, intangible assets and knowledge creation
Authors: Hussi Tomi
Published: May 2004

Intellectual capital, intangible assets and knowledge creation are all concepts that are strongly linked to the phenomenon of knowledge management. Yet they have only been parallel to each other. This controversy between different approaches has also resulted in vague definitions of knowledge management. This paper will critically discuss the definitions of these concepts. The analysis shows that different concepts actually focus on different angles of the topic. Based on this, a model will be built that ties all of them into a unitary entity. At the same time, this model gives a reconfigured definition of the concept of knowledge management.
Managing knowledge work: specialization and collaboration of engineering problem‐solving
Authors: Kim Jeffrey , King John
Published: May 2004

In this paper we investigate the exploratory nature of knowledge creation and sharing practice in high‐technology industry. Traditional approaches in knowledge management focus on the storage and retrieval of knowledge, but they do not address the tacit dimension of knowledge process. Using data gathered at three semiconductor manufacturers in Japan and Korea, we examine the social processes by which expert teams cooperate across team boundaries despite differing points of view resulting from increasing team specialization. Three engineering teams are studied: design, process, and process integration. They are responsible for trouble management in the production of dynamic random access memory (DRAM), a class of integrated circuit semiconductor devices. Trouble management is the handling of problems that require exploratory, yet routine problem‐solving practice. The findings suggest that the crucial challenge in achieving effective control of the knowledge management process rests not in strategies for collecting and classifying relevant problem/solution information. Rather, it is in the management of “problematization”, a political process involving the articulation behaviors of different teams of engineers.
The reward effect: a case study of failing to manage knowledge
Authors: Gal Yoav
Published: May 2004

This article describes an organization that took great interest in the idea of knowledge management and launched such initiatives. Despite the success of five KM projects during the years 2000 to 2002, senior management decided to discontinue all such initiatives. The purpose of this article is to examine the reasons for such a phenomenon.
Facilitating knowledge sharing in Russian and Chinese subsidiaries: the role of personal networks and group membership
Authors: Hutchings Kate , Michailova Snejina
Published: May 2004

The unprecedented escalation in the number of organizations that have decided to internationalize their operations in the last two decades, and the international movement of labor that has accompanied such expansion has meant that understanding the process of knowledge sharing within subsidiary operations has become an issue of increasing importance. Where the cultural distance between home and host nations is great, as it is between Western industrialized economies and the transition economies of the (former) Communist nations, there is even greater saliency for achieving effective knowledge sharing if its potential value for gaining organizational competitive advantage is to be harnessed. In examining knowledge sharing in Russia and China, this paper specifically addresses how group membership and personal networking in these countries facilitate and impede knowledge sharing. Ultimately, the paper provides important insights for Western managers about how to work with the national compositions to optimize knowledge sharing in their subsidiary operations in Russia and China.
Knowledge management in a public organization: a study on the relationship between organizational elements and the performance of knowledge transfer
Authors: Omar Sharifuddin Syed‐Ikhsan Syed , Rowland Fytton
Published: May 2004

Relatively little study has been performed on knowledge management and knowledge transfer in the public sector, and even less in the developing countries. This paper investigates the relationship between organizational elements and the performance of knowledge transfer. Five main independent variables were identified – organizational culture, organizational structure, technology, people/human resources and political directives – and these were tested against creation of knowledge assets and knowledge transfer performance using the Spearman rank test. Tacit and explicit knowledge were also tested against knowledge transfer performance. To achieve an in‐depth empirical study, the Ministry of Entrepreneur Development of Malaysia was chosen for a case study. The findings are based on replies to a questionnaire survey done from September to December 2001. The results reveal that there are significant relationships between some of the variables and either the creation of knowledge assets or the performance of knowledge transfer. Therefore, it is necessary for organizations to consider some of the elements that show a relationship between the tested variables in implementing a knowledge management strategy in an organization. However, certain variables that did not show any relationship should not be ignored totally, as they are still very important for some organizations.
Improving the use of know‐how in organizations by reconciling enablers and contributors
Authors: Blackmore Aliah
Published: May 2004

This paper explores the impact of IT upon the use of know‐how within the organization. An attempt is made to determine whether measures to improve the interaction between IT systems and users can also improve the way that know‐how is used in the organization. In this context, the purpose of this paper is two‐fold: to present ideas that can be used to understand current development in specific organizations[1]; and to outline measures for applying such ideas to other organizations in the future.
The diffusion of tacit knowledge and its implications on information systems: the role of meta‐abilities
Authors: Hisyam Selamat Mohamad , Choudrie Jyoti
Published: May 2004

Diffusing tacit knowledge, a transparent and subjective form of knowledge, needs an individual’s ability to externalize and sharing of this knowledge. This paper proposes a framework for the diffusion of tacit knowledge by using the concept of meta‐abilities. The argument of this research is that meta‐abilities develop individual influencing skills and sharing attitudes. These two elements in turn enable individuals to externalize their tacit knowledge in the form of creative idea, actions, reactions and reflection. Documenting these externalized and shared knowledge can provide a basis to keep information systems (IS) updated with relevant and reliable “best practices”. From a discussion of this framework, it is concluded that the future focus for the diffusion of tacit knowledge should be toward an individual’s meta‐abilities development that develop creativity and interpretivity. There should also be an impetus towards creating the right organizational culture and infrastructure that promotes tacit knowledge sharing and externalization within and between employees.
Compact and extremally disconnected spaces
Authors: Nayar Bhamini M. P.
Published: May 2004

Viglino defined a Hausdorff topological space to be C‐compact
if each closed subset of the space is an H‐set in the sense of
Veličko. In this paper, we study the class of Hausdorff spaces
characterized by the property that each closed subset is an
S‐set in the sense of Dickman and Krystock. Such spaces are
called C‐s‐compact. Recently, the notion of strongly
subclosed relation, introduced by Joseph, has been utilized to
characterize C‐compact spaces as those with the property that
each function from the space to a Hausdorff space with a strongly
subclosed inverse is closed. Here, it is shown that
C‐s‐compact spaces are characterized by the property that
each function from the space to a Hausdorff space with a strongly
sub‐semiclosed inverse is a closed function. It is established
that this class of spaces is the same as the class of Hausdorff,
compact, and extremally disconnected spaces. The class of
C‐s‐compact spaces is properly contained in the class of
C‐compact spaces as well as in the class of S‐closed spaces
of Thompson. In general, a compact space need not be
C‐s‐compact. The product of two C‐s‐compact spaces need
not be C‐s‐compact.
A Gauss‐Kuzmin‐Lévy theorem for a certain continued fraction
Authors: Chan Hei-Chi
Published: May 2004

We consider an interval map which is a generalization of the
well‐known Gauss transformation. In particular, we prove a result
concerning the asymptotic behavior of the distribution functions
of this map.
Numerical approximation for integral equations
Authors: Deeba Elias , Xie Shishen
Published: May 2004

A numerical algorithm, based on a decomposition technique, is
presented for solving a class of nonlinear integral equations.
The scheme is shown to be highly accurate, and only few terms are
required to obtain accurate computable solutions.
Control of rigid and flexible objects on a pneumatic active surface device
Authors: Šafarič Riko , Uran Suzana , Winther Tobias
Published: May 2004

Submillimeter or even micro-sized objects, such as micromechatronics, are becoming increasingly important and have the potential of making a huge impact on our society. Current manufacturing techniques are, however, incapable of massively parallel automated handling of objects at these scales, thereby limiting the possibilities of widespread commercial success in these fields (e.g., micro-electromechanical system, MEMS). In response to this type of challenge, a programmable, closed-loop controllable, pneumatic active surface device has been developed, the details of which are presented in this paper. It is a fundamentally new approach to automated massive parallel small-sized parts manipulation. By regulating the air flow in and out of numerous small orifices, the pneumatic active surface device, is shown to cause objects placed on the array to be moved in ways that are useful. It offers great flexibility, speed and the possibility of potentially handling many objects simultaneously. It can be employed to position, orient, identify, sort, feed, and assemble parts or objects. The first part of this paper describes the experimental device used to prove the concept and possible applications. The latter part of the paper goes into detail on the basics of closed-loop motion and positioning control techniques for rigid (VLSI chips, MEMS) objects and the control of flexible (PVC polyvinyl foil, paper) objects.
Smart sensor for operational load measurement
Authors: Petko Maciej , Uhl Tadeusz
Published: May 2004

Operation load measurement is an important technique enabling machine health monitoring and fault localization; however, direct measurement is usually difficult or impossible. The paper deals with the development of a smart sensor, which estimates the load based on structure response. In case studies, a hardware neural network was used to obtain the load course from structure vibrations - shaker-excited in a steel frame, and arising during landing in a landing gear of an airplane. The paper describes the prototype of a smart sensor, and design and implementation of load identification algorithm. For monitoring purposes, signal processing had to be done in real-time; additionally the highest possible integration level is desired, and thus a field programmable gate array (FPGA) chip was selected as the hardware platform for load estimation. The methodology of signal processing algorithms, implementation in application-specific integrated circuit (ASIC)/FPGA was developed, which allows for automation of the most time-consuming and error-prone tasks. Moreover, the same code, being the starting point for hardware synthesis, can be used in a Matlab/Simulink environment, enabling high-level system simulation and algorithm verification. Details of the procedure are presented, along with the tools used and results obtained during its realization. Performance of the smart sensor during experiment is analysed and, finally, conclusions are shown.
Machine vision using image data feedback for fault detection in complex deformable webs
Authors: Farooq Umer , King Tim , Gaskell P. H. , Kapur N.
Published: May 2004

Complex deformable webs like lace fabrics are amongst the most complicated materials to be inspected without any human intervention. The ability of such webs to deform easily, along with their complex patterns, presents a challenging problem for any machine vision system. Their pattern complexity makes it very difficult to use any global image processing or rule-based techniques for inspection, leaving direct comparison with a perfect prototype as the only choice available. Due to the elastic nature of the lace fabric, small distortions are characteristic of the product and are unavoidable. This renders sensitive direct comparison methods, such as those employed for the automatic inspection of printed circuit boards, prone to unacceptable false alarms. In the present work, the authors have exploited a mechatronic methodology, coupled with image processing techniques, to develop a high-speed inspection station for complex patterned lace webs.
An enhanced constant sample-time digital tachometer through oversampling
Authors: Kavanagh Richard C.
Published: May 2004

High-quality digital tachometers are incorporated into servo, mechatronic, robotic and precision production systems for the calculation of accurate, high-bandwidth, digital velocity information. The M/T-type tachometer and the related constant sample-time digital tachometer (CSDT) have been shown to perform well in many such systems. However, sensor nonideality can introduce very significant errors into the tachometer output. In this paper, it is shown that performance can be greatly improved (i.e., the noise present in the velocity signal significantly reduced) by oversampling the counter values used for velocity calculation. The counting and oversampling operations inherent to the oversampled CSDT (OCSDT) are implemented using a field-programmable gate array (FPGA). The design of the digital circuitry is described in detail, with particular emphasis on the circuits required for implementation and control of the oversampling operation. The FPGA acts as a peripheral device to a digital signal processor (DSP). Besides implementing some division-based calculations to generate a velocity word, the DSP can carry out other measurement and control functions, as required by the overall system. Simulation studies and experimental results are used to highlight the advantages of the over-sampling technique.
Highly positive intraoperative fluid balance during cardiac surgery is associated with adverse outcome
Authors: Toraman Fevzi , Evrenkaya Serdar , Yuce Murat , Turek Onur , Aksoy Nazan , Karabulut Hasan , Demirhisar Önder , Alhan Cem
Published: May 2004

Hemodilution and increase in capillary permeability occurring with cardiopulmonary bypass (CPB) impose a risk for tissue edema and blood transfusion that may result in an increased complication rate after coronary artery bypass grafting (CABG).

Of the 1280 consecutive patients undergoing isolated on-pump CABG, total fluid balance at the end of the operation was less than or equal to 500 mL in 1155 (Group 1) and more than 500 mL in 125 (Group 2). During CPB, blood was added to the reservoir only when the hematocrit fell to 17% or less and crystalloid solution only when the pump flow index fell below 2.0 L/min/m2. Anesthetic, surgical, and postoperative management and diagnoses were the same in all patients, and a single surgical and anesthesia team performed all operations. No patient was excluded from the study.

Results: Hypertension, diabetes, chronic obstructive pulmonary disease, New York Heart Association (NYHA) Class III - IV, use of angiotensin converting enzyme (ACE) inhibitors, chronic renal failure, and female gender were the significant preoperative risk factors for increased volume replacement during CPB. The groups were similar in body mass index, preoperative hematocrit values, total fluid balance in the intensive care unit (ICU), and total chest tube output. However, red blood cells’ transfusion rate, readmission rate to the ICU and length of hospital stay were significantly higher in Group 2 patients. Multiple logistic regression revealed that age < 70 years ( p < 0.001, Odds Ratio (OR): 2, 95% CI: 1.4 - 2.8), and total fluid balance > 500 mL at the end of the operation ( p < 0.01, OR: 2.2, 95% CI: 1.5-3.2) were the predictors of increased length of stay. For transfusion of red blood cells, age > 70 years ( p < 0.0001, OR: 2.3, 95% CI: 1.6-3.3), and total fluid balance > 500 mL at the end of the operation ( p < 0.001, OR: 2, 95% CI: 1.3-2.9) were the only significant risk factors.

This study suggests that intraoperative volume overload increases blood transfusion and length of hospital stay in patients undergoing CABG.
Inflammatory response in an immunosuppressed patient with Wegener’s granulomatosis
Authors: Mirsadraee Saeed , Fraser Alexander , Kerr Michael A , James Teifi E , van Doorn Carin
Published: May 2004

Background: The use of cardiopulmonary bypass (CPB) triggers a systemic inflammatory response (IR), but it is not known if a similar response occurs in an immuno-suppressed patient with autoimmune disease.

Methods and results: Observational study in a 56-year-old man receiving immunosuppressive therapy for Wegener’s granulomatosis (WG) who underwent aortic valve replacement on CPB. The following markers for IR were studied in the perioperative period: C3a, C5a, neutrophil elastase (NE), interleukin eight (IL-8), white cell count (WCC) and C-reactive protein (CRP). Results were compared with published literature on the IR in patients undergoing coronary revascularisation with and without the use of CPB. All inflammatory markers increased in the perioperative period. The intensity of IR was markedly reduced compared to published literature for patients undergoing coronary revascularisation on CPB and the temporal patients and extend resembled that for off-pump.

Conclusion: In a patient with WG on immunosuppressive therapy the CPB-related IR is reduced.
Effect of cardiopulmonary bypass on leukocyte activation: changes in membrane-bound elastase on neutrophils
Authors: Tang M , Gu Y J , Wang W J , Xu Y P , Chen C Z
Published: May 2004

Background: Neutrophil elastase is known to be released from the activated leukocytes as a result of cardiopulmonary bypass (CPB). However, its biological effect on organ injury is questionable because it is quickly bound by natural proteinase inhibitors (PIs). Recently, membrane-bound elastase (MBE) was found to be able to resist the PIs’ process and, thus, is biologically more active. This paper studies the effect of CPB on the kinetic change of MBE and its possible link to postoperative inflammation and organ function.

Method: Ten consecutive patients undergoing elective coronary artery bypass grafting (CABG) surgery with CPB were recruited into the study. Blood samples were taken before sternotomy, after aortic declamping, at the end of CPB, three and six hours after CPB and on the first postoperative day. MBE was determined by substrate assay from isolated neutrophils. Inflammation and organ function markers were determined according to routine laboratory methods.

Results: MBE slightly increased after aortic declamping, while it significantly increased and reached its peak at the end of CPB; it returned to its preoperative level on the first postoperative day. In contrast to lung sequestration of neutrophils, there was no transpulmonary gradient of MBE between left and right atria after aortic declamping. Neither MBE nor total MBE activity was positively correlated with postoperative inflammation markers such as blood lactate and C-reactive protein and organ function markers such as creatine phosphokinase and alanine aminotransferase.

Conclusions: CPB induces increased MBE expression on neutrophils with its peak at the end of CPB. Lack of association between neutrophil MBE and clinical markers suggests that multiple systems might be involved in the post-CPB inflammatory reaction and organ dysfunction.
Pump-induced haemolysis: a comparison of short-term ventricular assist devices
Authors: Bennett M , Horton S , Thuys C , Augustin S , Rosenberg M , Brizard C
Published: May 2004

Centrifugal pumps are superior to roller pumps for extended support durations in terms of pump-induced haemolysis. In this study, we evaluated the commonly used Biomedicus BP 50 and compared it with the Jostra Rotaflow and a standard roller pump in an in vitro test circuit. Each circuit was run for a six-day period and repeated five times. Plasma haemoglobin values showed the roller pump to become more haemolytic than the Biomedicus ( p = 0.022) and the Rotaflow. A statistically significant difference between the Biomedicus and the Rotaflow was observed on day six of the trial ( p = 0.016), with the Rotaflow showing lower levels of haemolysis than the Biomedicus. These results support the use of the new generation centrifugal pump, the Rotaflow, as a suitable device for short-term ventricular assist.
Highest core temperature during cardiopulmonary bypass and rate of mediastinitis
Authors: Groom Robert C , Rassias Athos J , Cormack John E , DeFoe Gordon R , DioDato Christian , Krumholz Charles K , Forest Richard J , Pieroni John W , O’Connor Brian , Warren Craig S , Olmstead Elaine M , Ross Cathy S , O’Connor Gerald T ,   Northern New England Cardiovascular Disease Study Group
Published: May 2004

Temperature control during cardiopulmonary bypass (CPB) may be related to rates of bacterial infection. We assessed the relationship between highest core temperature during CPB and rates of mediastinitis in 6955 consecutive isolated coronary artery bypass graft (CABG) procedures in northern New England.

The overall rate of mediastinitis was 1.1%. The association between highest core temperature and mediastinitis was different for diabetics than for nondiabetics. A multivariate model showed that there was a significant interaction between diabetes and temperature in their association with mediastinitis ( p = 0.015). Diabetic patients showed higher rates of mediastinitis as highest core temperature increased, from 0.7% in the ≤37°C group to 3.3% in the ≥38°C group ( ptrend = 0.002). Adjusted rates were similar. Nondiabetic patients did not show this trend ( ptrend = 0.998).

Among diabetic patients, a peak core body temperature > 37.9°C during CPB is a significant risk factor for development of mediastinitis. Avoidance of higher temperatures during CPB may lower the risk of mediastinitis for diabetic patients undergoing CABG surgery.
Assimilation of data into an ocean model with systematic errors near the equator
Authors: Bell M. J. , Martin M. J. , Nichols N. K.
Published: May 2004

Assimilation of thermal data into an ocean model near the equator often results in a dynamically unbalanced state with unrealistic deep overturning circulations. The way in which these circulations arise from errors in the model or its forcing and the equatorial dynamics is discussed. A scheme is proposed to calculate a state with a better balance by using the observational increments to the model to update slowly evolving bias fields. These bias fields augment the model state and affect the model's pressure gradients. The properties of the augmented shallow‐water equations are examined. When forced by steady incorrect wind stresses, solutions of the augmented equations assimilating full fields of surface height data converge to the correct surface height and vertical velocity fields. © Royal Meteorological Society, 2004. The contributions of M. J. Bell and M. J. Martin are Crown copyright.
The extratropical transition of hurricane Irene (1999): A potential‐vorticity perspective
Authors: Agusti‐panareda A. , Thorncroft C. D. , Craig G. C. , Gray S. L.
Published: May 2004

Extratropical transition (ET) of tropical cyclones is common in all ocean basins where tropical cyclones recurve polewards. After the tropical cyclone experiences ET, a rapid deepening can take place resulting in the development of a very large and deep extratropical cyclone. The ET of hurricane Irene (1999) was an example of such an ‘explosive’ ET. Irene formed in the Caribbean and experienced ET as it moved poleward, resulting in a low‐pressure system which deepened 39 hPa in 24 hours (according to the Met Office analyses). The extent to which the hurricane was responsible for the explosive extratropical development has been determined by performing Met Office Unified Model forecasts from initial states with and without the hurricane. The circulation and temperature anomalies associated with the hurricane were removed from the initial state using potential‐vorticity inversion. The moisture anomaly co‐located with the hurricane core was also removed. The results show that an extratropical cyclogenesis event takes place regardless of the presence of the hurricane in the initial conditions. However, the hurricane makes a significant difference to the track and central mean‐sea‐level pressure evolution of the resulting extratropical cyclone. When Irene was present the track of the extratropical cyclone was more zonal and the cyclone deepening rate was twice as fast as when Irene was not present. These effects appear to be particularly associated with a negative potential‐vorticity anomaly and enhanced divergent flow in the region of the upper‐level outflow of the transforming hurricane rather than with the hurricane vortex. Results also show that the presence of the hurricane resulted in a significant downstream surface‐low development in the eastern Atlantic. Copyright © 2004 Royal Meteorological Society.
Effects of convection on the removal of the multiplicity of stable states in one‐dimensional vertical models
Authors: Pujol Toni
Published: May 2004

Here I develop a model of a radiative–convective atmosphere with both radiative and convective schemes highly simplified. The atmospheric absorption of radiation at selective wavelengths makes use of constant mass absorption coefficients in finite width spectral bands. The convective regime is introduced by using a prescribed lapse rate in the troposphere. The main novelty of the radiative–convective model developed here is that it is solved without using any angular approximation for the radiation field. The solution obtained in the purely radiation mode (i.e. with convection ignored) leads to multiple equilibria of stable states, being very similar to some results recently found in simple models of planetary atmospheres. However, the introduction of convective processes removes the multiple equilibria of stable states. This shows the importance of taking convective processes into account even for qualitative analyses of planetary atmospheres. Copyright © 2004 Royal Meteorological Society.
Assessment of wind‐stress errors using bias corrected ocean data assimilation
Authors: Huddleston M. R. , Bell M. J. , Martin M. J. , Nichols N. K.
Published: May 2004

Current seasonal forecasting methods make extensive use of wind‐stress products and ocean thermal profile observations to produce ocean analyses for retrospective forecasts. The combination of inaccurate wind‐stress forcing and relatively accurate ocean thermal profile observations can have significant detrimental impacts on the analysis in equatorial regions as it leads to an imbalance between the zonal pressure gradient and wind stress. Model integrations have been performed to assess various wind‐stress products using a Pacific region ocean general‐circulation model in three assimilation modes. The assimilation of thermal profile data has been shown to impact negatively on the zonal and vertical current structure. A bias correction scheme has been used to illustrate how these errors can be mitigated. The method used to correct for these systematic errors allows for the errors to evolve in time and space. The strength of the equatorial undercurrent is brought to a realistic level, but the scheme does reduce its variability. The European Remote Sensing satellite scatterometer wind products have been used to illustrate the methodology and comparisons have been drawn with several other wind‐stress products. © Royal Meteorological Society, 2004. Contributions by M. R. Huddleston, M. J. Bell and M. J. Martin are Crown copyright.
A simplified bi‐dimensional variational analysis of soil moisture from screen‐level observations in a mesoscale numerical weather‐prediction model
Authors: Balsamo G. , Bouyssel F. , Noilhan J.
Published: May 2004

The analysis of soil moisture for the initialization of a mesoscale numerical weather‐prediction (NWP) model is considered subject to operational constraints, both in terms of computational cost and data availability. A variational technique is used to analyse the soil moisture by assimilating screen‐level observations of temperature and relative humidity. We consider a simplified bi‐dimensional (z and t) variational approach (simplified 2D‐VAR), where the estimate of the observation operator is obtained from extra integration(s) of the numerical model. The fundamental assumptions of the method are first evaluated: linearity of the observation operator, horizontal decoupling between grid points, and truncation of the control variable space (variable decoupling), that allow the simplified 2D formalism. Thus, the variational method is applied at each grid point separately and the gain matrix is computed from finite differences given the small dimension involved. The 2D‐VAR technique keeps count of the full physics of the model, so the corrections applied to the control variable are adapted to the current meteorological conditions and the grid‐point characteristics (texture and vegetation), as well as to the previous soil state. The linear estimate of the observation operator is studied in detail to optimize its evaluation. The validation of the method is shown with simulated observations, and the assimilation of real observations is performed with different time‐windows. A sequential assimilation cycle on a 6‐hour time‐window allows the comparison with the optimum interpolation technique, while a 24‐hour window is considered to extend the temporal consistency of the assimilated observations in the analysis. Results from the performed analyses with the simplified 2D‐VAR method show a good retrieval of soil moisture, and a comparison with other initialization methods is also provided. Copyright © 2004 Royal Meteorological Society.
The response time of a convective cloud ensemble to a change in forcing
Authors: Cohen Brenda G. , Craig George C.
Published: May 2004

In this paper, the timescale of the convective mass‐flux response to step‐function changes in external forcing conditions is measured directly using idealized cloud‐resolving model simulations of unorganized convection in radiative–convective equilibrium. Many parametrization schemes require an estimate of this response time in the form of a fixed adjustment timescale, but the physical mechanism which sets its value is currently unknown. These experiments confirm the existence of a unique timescale, for given initial forcing conditions, of the order of one hour. The hypothesized role of gravity waves in effecting the convective adjustment is tested by changing the mean cloud spacing of the initial state. This reveals a linear dependence of the response time on the cloud spacing, in agreement with the theory. Meanwhile, similar experiments to investigate the sensitivity of the timescale to changes in gravity‐wave speed reveal a remarkable robustness of the average wave speed over a range of stratifications and tropospheric depths. Copyright © 2004 Royal Meteorological Society.
The effect of overlying absorbing aerosol layers on remote sensing retrievals of cloud effective radius and cloud optical depth
Authors: Haywood Jim M. , Osborne Simon R. , Abel Steven J.
Published: May 2004

Two types of partially absorbing aerosol are included in calculations that are based on intensive aircraft observations: biomass burning aerosol characterized during the Southern AFricAn Regional science Initiative (SAFARI 2000) and mineral dust aerosol characterized during the SaHAran Dust Experiment (SHADE). Measurements during SAFARI 2000 reveal that the biomass burning aerosol layer is advected over the South Atlantic ocean at elevated altitudes above the marine boundary layer which is capped by semi‐permanent stratocumulus cloud sheets. Similarly, the mineral dust is measured at elevated altitudes during SHADE resulting in transport above cloud for distances of several thousands of kilometres. We perform theoretical calculations of the effect of these partially absorbing aerosol layers on satellite retrievals of cloud effective radius and cloud optical depth, and show that, in these cases, retrievals of cloud optical depth or liquid water path are likely to be subject to systematic low biases. The theoretical calculations suggest that the cloud effective radius may be subject to a significant low bias for Moderate resolution Imaging Spectrometer (MODIS) retrievals that rely on the 0.86 and 1.63 µm radiance pair for an overlying aerosol layer of either biomass burning aerosol or mineral dust. Conversely, the cloud effective radius may be subject to a significant high bias for Advanced Very High Resolution Radiometer or MODIS retrievals that rely on the 0.63 and 3.7 µm radiance pair for an overlying aerosol layer of mineral dust. Analysis of 1 km resolution MODIS data for the SAFARI 2000 period suggests that the effective radius derived from the 0.86 and 1.63 µm radiance pair is, indeed, subject to a low bias in the presence of overlying biomass burning aerosol. These results show the difficulties associated with remote sensing retrievals, which must be kept in mind when attempting to assess any potential indirect effect. © Crown copyright 2004.
The capability of 4D‐Var systems to assimilate cloud‐affected satellite infrared radiances
Authors: Chevallier Fr'ed'eric , Lopez Philippe , Tompkins Adrian M. , Janisková Marta , Moreau Emmanuel
Published: May 2004

Four‐dimensional variational (4D‐Var) assimilation schemes assume the linearity of their forward model in the vicinity of prior information and usually do not properly handle variables that have finer temporal and spatial scales in the real world than in the forward model. Hence cloud‐affected satellite infrared radiances are discarded from numerical weather‐prediction 4D‐Var systems, despite the critical need of observations within the cloudy regions. This paper suggests the reappraisal of that choice, subject to achieving improvements in the numerical simulation of cloudiness.

A new observation operator, that computes cloud‐affected infrared radiances from 4D‐Var control variables, namely atmospheric temperature, humidity, ozone, surface temperature and surface pressure, is presented. The vertical distributions of cloud cover and of cloud condensate are diagnosed in the operator itself. The goal of this paper is to assess the feasibility of using it to assimilate cloud‐affected infrared radiances, such as those from the narrow‐band Advanced Infrared Sounder on‐board the Aqua platform or those from the broad‐band Meteosat Visible and Infrared Imager. It is shown that there is a potential benefit in assimilating directly in 4D‐Var some of the upper‐tropospheric channels at 4.5, 6.3 and 14.3 µm in the presence of clouds, for instance the 6.3 µm channel on board all the geostationary satellites. The approach is illustrated with one‐dimensional variational retrievals collocated with radiosonde observations. © Royal Meteorological Society, 2004.