bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of secure cryptography against the threat of power-attacks in DSP-embedded processors
Authors: Gebotys Catherine H.
Published: August 2005

Embedded wireless devices require secure high-performance cryptography in addition to low-cost and low-energy dissipation. This paper presents for the first time a design methodology for security on a VLIW complex DSP-embedded processor core. Elliptic curve cryptography is used to demonstrate the design for security methodology. Results are verified with real dynamic power measurements and show that compared to previous research a 79% improvement in performance is achieved. Modification of power traces are performed to resist simple power analysis attack with up to 39% overhead in performance, up to 49% overheads in energy dissipation, and up to 11% overhead in code size. Simple power analysis on the VLIW DSP core is shown to be more correlated to routine ordering than individual instructions. For the first time, differential power analysis results on a VLIW using real power measurements are presented. Results show that the processor instruction level parallelism and large bus size contribute in making differential power analysis attacks extremely difficult. This research is important for industry since efficient yet secure cryptography is crucial for wireless communication devices.
Iterative schedule optimization for voltage scalable distributed embedded systems
Authors: Schmitz Marcus T. , Al-Hashimi Bashir M. , Eles Petru
Published: August 2005

We present an iterative schedule optimization for multirate system specifications, mapped onto heterogeneous distributed architectures containing dynamic voltage scalable processing elements (DVS-PEs). To achieve a high degree of energy reduction, we formulate a generalized DVS problem, taking into account the power variations among the executing tasks. An efficient heuristic is presented that identifies optimized supply voltages by not only "simply" exploiting slack time, but under the additional consideration of the power profiles. Thereby, this algorithm minimizes the energy dissipation of heterogeneous architectures, including power-managed processing elements, effectively. Further, we address the simultaneous schedule optimization toward timing behavior and DVS utilization by integrating the proposed DVS heuristic into a genetic list scheduling approach. We investigate and analyze the possible energy reduction at both steps of the co-synthesis (voltage scaling and scheduling), including the power variations effects. Extensive experiments indicate that the presented work produces solutions with high quality.
VR for public consumption
Authors: Lee Newton
Published: August 2005

Artists and educators using immersive virtual reality are
interested in creating content for the general public. Such
activity has always existed alongside hard-core VR research.
Publicly-accessible VR presents difficulties not faced in research
with small groups of knowledgeable users or in industrial VR
applications. We believe these problems must be addressed to bring
VR to the public:

This workshop will connect researchers with those who use VR in
the public realm, document what has been done to make VR fit for
public consumption, and identify what still needs to be done. We
envision the workshop consisting of short presentations, followed
by open discussion allowing participants to network and define new
plans of action.
Tools for children to create physical interactive storyrooms
Authors: Montemayor Jaime , Druin Allison , Chipman Gene , Farber Allison , Guha Mona Leigh
Published: August 2005

Over the past few years, researchers have been exploring
possibilities for ways in which embedded technologies can enrich
childrens storytelling experiences. In this article we present our
research on physical interactive storytelling environments from a
childs perspective. We present the system architecture as well as a
formative study of the technologys use with 18 children, ages 5-6.
We discuss the challenges and opportunities for kindergarten
children to become creators of their own physical storytelling
interactions.
A design flow for partially reconfigurable hardware
Authors: Robertson Ian , Irvine James
Published: August 2005

This paper presents a top-down designer-driven design flow for creating hardware that exploits partial run-time reconfiguration. Computer-aided design (CAD) tools are presented, which complement conventional FPGA design environments to enable the specification, simulation (both functional and timing), synthesis, automatic placement and routing, partial configuration generation and control of partially reconfigurable designs. Collectively these tools constitute the dynamic circuit switching CAD framework. A partially reconfigurable Viterbi decoder design is presented to demonstrate the design flow and illustrate possible power consumption reductions and performance improvements through the exploitation of partial reconfiguration.
Blocking-aware processor voltage scheduling for real-time tasks
Authors: Zhang Fan , Chanson Samuel T.
Published: August 2005

As mobile computing is getting popular, there is a growing need for techniques that minimize energy consumption on battery-powered mobile devices. Processor voltage scheduling can effectively reduce processor energy consumption by lowering the processor speed. In this paper, we study voltage scheduling for real-time periodic tasks with non-preemptible sections. Three schemes are proposed: The static speed algorithm derives the minimum static feasible speed based on the stack resource policy. Due to blocking, this static speed is usually higher than the speed required for scheduling fully preemptible tasks (called the utilization speed). Two dynamic speed algorithms are then introduced to further reduce energy consumption. The novel dual speed algorithm operates the processor at the utilization speed whenever possible and switches to the higher static speed only when blocking occurs. The dual speed dynamic reclaiming algorithm reserves time budget for each job, reclaims the unused time budget from completed jobs and redistributes it to subsequent jobs so they can run at a lower speed whenever possible. Feasibility conditions for real-time task sets have been derived and proved mathematically. Simulation results show that the proposed voltage scheduling algorithms dramatically reduce processor energy consumption over non-power-aware scheduling algorithms. Furthermore, the two dynamic speed algorithms consistently outperform the static speed scheme in a wide range of system and workload conditions.
Fast prefix matching of bounded strings
Authors: Buchsbaum Adam L. , Fowler Glenn S. , Kirishnamurthy Balachannder , Vo Kiem-Phong , Wang Jia
Published: August 2005

Longest Prefix Matching (LPM) is the problem of finding which string from a given set is the longest prefix of another, given string. LPM is a core problem in many applications, including IP routing, network data clustering, and telephone network management. These applications typically require very fast matching of bounded strings, i.e., strings that are short and based on small alphabets. We note a simple correspondence between bounded strings and natural numbers that maps prefixes to nested intervals so that computing the longest prefix matching a string is equivalent to finding the shortest interval containing its corresponding integer value. We then present
retries
, a fast and compact data structure for LPM on general alphabets. Performance results show that retries often outperform previously published data structures for IP look-up. By extending LPM to general alphabets, retries admit new applications that could not exploit prior LPM solutions designed for IP look-ups.
A blocked all-pairs shortest-paths algorithm
Authors: Venkataraman Gayathri , Sahni Sartaj , Mukhopadhyaya Srabani
Published: August 2005

We propose a blocked version of Floyd's all-pairs shortest-paths algorithm. The blocked algorithm makes better utilization of cache than does Floyd's original algorithm. Experiments indicate that the blocked algorithm delivers a speedup (relative to the unblocked Floyd's algorithm) between 1.6 and 1.9 on a Sun Ultra Enterprise 4000/5000 for graphs that have between 480 and 3200 vertices. The measured speedup on an SGI O2 for graphs with between 240 and 1200 vertices is between 1.6 and 2.
Schwann Cell Engraftment Into Injured Peripheral Nerve Prevents Changes in Action Potential Properties
Authors: Yu Kewei , Kocsis Jeffery D.
Published: August 2005

Peripheral nerve injury results in changes in action potential waveform, ion channel organization, and firing properties of primary afferent neurons. It has been suggested that these changes are the result of reduction in basal trophic support from skin targets. Subcutaneous injections of Fluro-Gold (FG) in the hind limb of the rat were used to identify cutaneous primary afferent neurons. Five days after FG injection, sciatic nerves were ligated and encapsulated in a silicon tube allowing neuroma formation. Green fluorescent protein (GFP)-expressing Schwann cells (SCs) were injected proximal to the cut end of the nerve. Thirteen to 22 days after injury and SC injection, the L4 and L5 dorsal root ganglia (DRG) were prepared for acute culture. Whole cell patch-clamp recordings in current clamp mode were obtained and action potential properties of medium-sized (34–45 μm) FG+ DRG neurons were characterized. In the neuroma group without cell transplantation, action potential duration and spike inflections were reduced as were the amplitude and duration of spike afterhyperpolarizations. These changes were not observed after transection by nerve crush where axons were allowed to regenerate to distal peripheral targets. In the transplantation group, GFP+-SCs were extensively distributed throughout the neuroma, and oriented longitudinally along axons proximal to the neuroma. Changes in action potential properties were attenuated in the GFP+-SC group. Thus the engrafted SC procedure ameliorated the changes in action potential waveform of cutaneous primary afferents associated with target disconnection and neuroma formation.
Presynaptic Angiotensin II AT1 Receptors Enhance Inhibitory and Excitatory Synaptic Neurotransmission to Motoneurons and Other Ventral Horn Neurons in Neonatal Rat Spinal Cord
Authors: Oz Murat , Yang Keun-Hang , O'Donovan Michael J. , Renaud Leo P.
Published: August 2005

In neonatal spinal cord, we previously reported that exogenous angiotensin II (ANG II) acts at postsynaptic AT1 receptors to depolarize neonatal rat spinal ventral horn neurons in vitro. This study evaluated an associated increase in synaptic activity. Patch clamp recordings revealed that 38/81 thoracolumbar (T7–L5) motoneurons responded to bath applied ANG II (0.3–1 μM; 30 s) with a prolonged (5–10 min) and reversible increase in spontaneous postsynaptic activity, selectively blockable with Losartan ( n = 5) but not PD123319 ( n = 5). ANG-II-induced events included both spontaneous inhibitory (IPSCs; n = 6) and excitatory postsynaptic currents (EPSCs; n = 5). While most ANG induced events were tetrodotoxin-sensitive, ANG induced a significant tetrodotoxin-resistant increase in frequency but not amplitude of miniature IPSCs ( n = 7/13 cells) and EPSCs ( n = 2/7 cells). In 35/77 unidentified neurons, ANG II also induced a tetrodotoxin-sensitive and prolonged increase in their spontaneous synaptic activity that featured both IPSCs ( n = 5) and EPSCs ( n = 4) when tested in the presence of selective amino acid receptor antagonists. When tested in the presence of tetrodotoxin, ANG II was noted to induce a significant increase in the frequency but not the amplitude of mIPSCs ( n = 9) and mEPSCs ( n = 8). ANG also increased spontaneous motor activity from isolated mouse lumbar ventral rootlets. Collectively, these observations support the existence of a wide pre- and postsynaptic distribution of ANG II AT1 receptors in neonatal ventral spinal cord that are capable of influencing both inhibitory and excitatory neurotransmission.
External Ca2+Dependency of Synaptic Transmission inDrosophila synaptotagmin IMutants
Authors: Okamoto Tomonori , Tamura Takuya , Suzuki Kazuhiro , Kidokoro Yoshiaki
Published: August 2005

To resolve some of differences in reports on the function of Synaptotagmin I (Syt I), we re-examined synaptic transmission at the neuromuscular junction of Drosophila embryos that have mutations in the Syt I gene ( syt I). Two major questions addressed were which Ca2+binding domain, C2A or C2B, sense Ca2+and is Syt I a negative regulator of spontaneous vesicle fusion. Synaptic currents were induced by nerve stimulation or by high K+treatment in external solutions containing various Ca2+concentrations. In a null allele, syt IAD4, synchronous synaptic currents were rarely observed but not abolished. The quantal content was about 1/60 of control but increased linearly with [Ca2+]ewith a slope of 0.95 ( N) in the double logarithmic plot, in contrast to 3.01 in control. The slope of 1.06 in an allele, syt IAD1, which lacks the second Ca2+binding domain, C2B, was not different from in syt IAD4. In another allele, syt IAD3, in which one amino acid in C2B is mutated, synchronous synaptic transmission was also impaired and N was 1.54, which is significantly smaller than in control. In high K+saline, the [Ca2+]edependency of vesicle release in syt IAD4was lower than in controls, whereas that in syt IAD3was even lower than in syt IAD4, suggesting that syt IAD3is inhibiting vesicle fusion. These findings led us to conclude that C2B, not C2A, senses Ca2+, and Syt I is a negative regulator of vesicle fusion.
Characterization of Atherosclerotic Plaques by Laser Speckle Imaging
Authors: Nadkarni Seemantini K. , Bouma Brett E. , Helg Tina , Chan Raymond , Halpern Elkan , Chau Alexandra , Minsky Milan Singh , Motz Jason T. , Houser Stuart L. , Tearney Guillermo J.
Published: August 2005

Background—

A method capable of determining atherosclerotic plaque composition and measuring plaque viscoelasticity can provide valuable insight into intrinsic features associated with plaque rupture and can enable the identification of high-risk lesions. In this article, we describe a new optical technique, laser speckle imaging (LSI), that measures an index of plaque viscoelasticity. We evaluate the potential of LSI for characterizing atherosclerotic plaque.

Methods and Results—

Time-varying helium-neon laser speckle images were acquired from 118 aortic plaque specimens from 14 human cadavers under static and deforming conditions (0 to 200 μm/s). Temporal fluctuations in the speckle patterns were quantified by exponential fitting of the normalized cross-correlation of sequential frames in each image series of speckle patterns to obtain the exponential decay time constant, τ. The decorrelation time constants of thin-cap fibroatheromas (TCFA) (τ=47.5±19.2 ms) were significantly lower than those of other atherosclerotic lesions (
P
<0.001), and the sensitivity and specificity of the LSI technique for identifying TCFAs were >90%. Speckle decorrelation time constants demonstrated strong correlation with histological measurements of plaque collagen (
R
=0.73,
P
<0.0001), fibrous cap thickness (
R
=0.87,
P
<0.0001), and necrotic core area (
R
=−0.81,
P
<0.0001). Under deforming conditions (10 to 200 μm/s), τ correlated well with cap thickness in necrotic core fibroatheromas (
P
>0.05).

Conclusions—

The measurement of speckle decorrelation time constant from laser speckle images provides an index of plaque viscoelasticity and facilitates the characterization of plaque type. Our results demonstrate that LSI is a highly sensitive technique for characterizing plaque and identifying thin-cap fibroatheromas.
Exercise Intolerance in Adult Congenital Heart Disease
Authors: Diller Gerhard-Paul , Dimopoulos Konstantinos , Okonko Darlington , Li Wei , Babu-Narayan Sonya V. , Broberg Craig S. , Johansson Bengt , Bouzas Beatriz , Mullen Michael J. , Poole-Wilson Philip A. , Francis Darrel P. , Gatzoulis Michael A.
Published: August 2005

Background—

Although some patients with adult congenital heart disease (ACHD) report limitations in exercise capacity, we hypothesized that depressed exercise capacity may be more widespread than superficially evident during clinical consultation and could be a means of assessing risk.

Methods and Results—

Cardiopulmonary exercise testing was performed in 335 consecutive ACHD patients (age, 33±13 years), 40 non–congenital heart failure patients (age, 58±15 years), and 11 young (age, 29±5 years) and 12 older (age, 59±9 years) healthy subjects. Peak oxygen consumption (peak V̇
o
2
) was reduced in ACHD patients compared with healthy subjects of similar age (21.7±8.5 versus 45.1±8.6;
P
<0.001). No significant difference in peak V̇
o
2
was found between ACHD and heart failure patients of corresponding NYHA class (
P
=NS for each NYHA class). Within ACHD subgroups, peak V̇
o
2
gradually declined from aortic coarctation (28.7±10.4) to Eisenmenger (11.5±3.6) patients (
P
<0.001). Multivariable correlates of peak V̇
o
2
were peak heart rate (
r
=0.33), forced expiratory volume (
r
=0.33), pulmonary hypertension (
r
=−0.26), gender (
r
=−0.23), and body mass index (
r
=−0.19). After a median follow-up of 10 months, 62 patients (18.5%) were hospitalized or had died. On multivariable Cox analysis, peak V̇
o
2
predicted hospitalization or death (hazard ratio, 0.937;
P
=0.01) and was related to the frequency and duration of hospitalization (
P
=0.01 for each).

Conclusions—

Exercise capacity is depressed in ACHD patients (even in allegedly asymptomatic patients) on a par with chronic heart failure subjects. Lack of heart rate response to exercise, pulmonary arterial hypertension, and impaired pulmonary function are important correlates of exercise capacity, as is underlying cardiac anatomy. Poor exercise capacity identifies ACHD patients at risk for hospitalization or death.
A Review of Current Investigations of Urban-Induced Rainfall and Recommendations for the Future
Authors: Shepherd J. Marshall
Published: August 2005

Precipitation is a key link in the global water cycle and a proxy for changing climate; therefore, proper assessment of the urban environment’s impact on precipitation (land use, aerosols, thermal properties) will be increasingly important in ongoing climate diagnostics and prediction, Global Water and Energy Cycle (GWEC) analysis and modeling, weather forecasting, freshwater resource management, urban planning–design, and land–atmosphere–ocean interface processes. These facts are particularly critical if current projections for global urban growth are accurate.

The goal of this paper is to provide a concise review of recent (1990–present) studies related to how the urban environment affects precipitation. In addition to providing a synopsis of current work, recent findings are placed in context with historical investigations such as Metropolitan Meteorological Experiment (METROMEX) studies. Both observational and modeling studies of urban-induced rainfall are discussed. Additionally, a discussion of the relative roles of urban dynamic and microphysical (e.g., aerosol) processes is presented. The paper closes with a set of recommendations for what observations and capabilities are needed in the future to advance our understanding of the processes.
Proxy-Based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Method, Predictor Network, Target Season, and Target Domain
Authors: Rutherford S. , Mann M. E. , Osborn T. J. , Briffa K. R. , Jones P D. , Bradley R. S. , Hughes M. K.
Published: August 2005

Results are presented from a set of experiments designed to investigate factors that may influence proxy-based reconstructions of large-scale temperature patterns in past centuries. The factors investigated include 1) the method used to assimilate proxy data into a climate reconstruction, 2) the proxy data network used, 3) the target season, and 4) the spatial domain of the reconstruction. Estimates of hemispheric-mean temperature are formed through spatial averaging of reconstructed temperature patterns that are based on either the local calibration of proxy and instrumental data or a more elaborate multivariate climate field reconstruction approach. The experiments compare results based on the global multiproxy dataset used by Mann and coworkers, with results obtained using the extratropical Northern Hemisphere (NH) maximum latewood tree-ring density set used by Briffa and coworkers. Mean temperature reconstructions are compared for the full NH (Tropics and extratropics, land and ocean) and extratropical continents only, withvarying target seasons (cold-season half year, warm-season half year, and annual mean). The comparisons demonstrate dependence of reconstructions on seasonal, spatial, and methodological considerations, emphasizing the primary importance of the target region and seasonal window of the reconstruction. The comparisons support the generally robust nature of several previously published estimates of NH mean temperature changes in past centuries and suggest that further improvements in reconstructive skill are most likely to arise from an emphasis on the quality, rather than quantity, of available proxy data.
A Wintertime Arctic Oscillation Signature on Early-Season Indian Ocean Monsoon Intensity
Authors: Buermann Wolfgang , Lintner Benjamin , Bonfils Céline
Published: August 2005

The Indian Ocean monsoon (IOM) exhibits considerable year-to-year variations that have previously been attributed to a number of forcing mechanisms including the El Niño–Southern Oscillation (ENSO) and Eurasian snow cover anomalies. In this study, spatial data of Eurasian spring land surface temperatures are analyzed as well as proxies for soil moisture, summer IOM precipitation, and summer IOM 850-mb zonal winds for the 1979–99 period to isolate correlated modes of variability. The results indicate the existence of a prominent mode that appears to be related to the boreal winter Arctic Oscillation (AO); this mode projects strongly on the June precipitation and 850-mb zonal wind fields in the vicinity of the IOM region. Its projection on spatial fields of temperature and proxies for soil moisture shows springtime surface warming and drying in the region to the north and west of the Indian subcontinent and cooling over the higher Eurasian latitudes during years of anomalously intense June monsoon rainfall. Such surface signatures are consistent with the negative phase winter AO. It is hypothesized that the preconditioning of the spring season surface characteristics may be associated with an AO-induced quasi-stationary tropospheric circulation anomaly: the impact of this anomaly is to displace the mid-Eastern jet poleward during AO-negative phases, resulting in anomalous surface heating and drying that persist into the later spring season and finally affect the rainfall over the IOM region in June.
Seasonal Variability in Clouds and Radiation at the Manus ARM Site
Authors: Mather James H.
Published: August 2005

The Atmospheric Radiation Measurement (ARM) program operates three climate observation stations in the tropical western Pacific region. One of these sites, located on Manus Island in Papua New Guinea, has been operating since 1996. The Manus ARM site includes an extensive array of instruments chosen to observe cloud properties, water vapor and temperature profiles, and the surface radiation budget. This dataset provides an opportunity to examine variability in tropical cloudiness on a wide range of time scales. The focus of this study is on the annual cycle. Analysis of cloud distribution and radiation data from Manus reveals a clear annual cycle in clouds associated with convective activity. The most convectively active period is found to be the Northern Hemisphere summer, while the least active period is the Northern Hemisphere autumn. Outgoing longwave radiation (OLR) data are also examined in order to relate observations at Manus with the surrounding region. Significant differences are found between the annual cycle at Manus and adjacent large islands within the Maritime Continent. Analysis of the combined ARM–OLR data suggests that during the Northern Hemisphere winter, a significant amount of the high clouds observed over Manus are associated with continental convection over the large Maritime Continent islands.
Academic nostalgia: A narrative approach to academic work
Authors: Ylijoki Oili-Helena
Published: August 2005

This article argues that one of the core narratives within the present-day university is a nostalgic story line. Drawing on focused interviews with 23 senior researchers in three academic environments in Finland, the article shows that although the nostalgic plot structure cuts across the data, it has different contents in each of the three settings, thus emphasizing the internal diversity in academic life. However, in all cases nostalgic yearning refers to the loss of academic freedom and autonomy in work. The article concludes that nostalgia does not describe the actual past but rather the problems and tensions of the present. It is an idealization of the past, the function of which is to clarify the values and morals of the organization, which in turn can help to come to terms with the conflicting pressures of the current situation.
Finite Element Analysis of Transversely Isotropic Viscoelastic Material for Thermoforming Process
Authors: Erchiqui F.
Published: August 2005

In this work, a dynamic finite element method is used in the modeling and numerical simulation of the transversely viscoelastic behavior of a thin, isotropic, and incompressible thermoplastic membrane. The transversely isotropic viscoelastic functional based on the kinetic theory of rubber elasticity is presented. The model is expressed in terms of four material parameters and equations relating these parameters. The thermoforming of the sheet is performed under the action of perfect gas flows. The Lagrangian formulation, together with the assumption of the membrane theory, is used in the finite element implementation. The numerical validation is performed by comparing the theoretical solution for the uniaxial and equibiaxial Hencky deformation with numerical results. Moreover, the influence of fiber direction in the transversely viscoelastic material on the thickness and on the stress distribution in the thermoforming sheet are analyzed.
The teaching of clinical skills in the context of children’s nursing: a UK survey
Authors: Mcnee Peter , Clarke Dave , Davies Jane
Published: August 2005

The teaching of clinical skills within nursing is currently enjoying a resurgence following the implementation of the ‘Fitness for Practice Curriculum’. However, the teaching of clinical skills specifically within children’s nursing has received little attention within the research arena. This article presents the data of a national postal survey sent to United Kingdom institutions providing pre-registration child branch studies, to ascertain the current provision of clinical skills teaching. The findings conclude that very few institutions have invested in specific skills laboratories to teach children’s nursing students. It was also identified that a wide range of clinical skills are taught to child branch students; however, the resources and realism to clinical practice is limited by the lack of specialist children’s skills laboratories or equipment. In conclusion the authors recommend the development of child specific skills laboratories, to augment child branch skills teaching, in order to enhance the realistic simulation of clinical practice.
Pilot study of losartan for pulmonary hypertension in chronic obstructive pulmonary disease
Authors: Morrell Nicholas W , Higham Matthew A , Phillips Peter G , Shakur B Haleema , Robinson Paul J , Beddoes Ray J
Published: August 2005

Background

Morbidity in COPD results from a combination of factors including hypoxia-induced pulmonary hypertension, in part due to pulmonary vascular remodelling. Animal studies suggest a role of angiotensin II and acute studies in man concur. Whether chronic angiotensin-II blockade is beneficial is unknown. We studied the effects of an angiotensin-II antagonist losartan, on haemodynamic variables, exercise capacity and symptoms.

Methods

This was a double-blind, randomized, parallel group, placebo- controlled study of 48 weeks duration. Forty patients with COPD and pulmonary hypertension (Tran tricuspid pressure gradient (TTPG) = 30 mmHg) were randomised to losartan 50 mg or placebo. Changes in TTPG were assessed at 3, 6 and 12 months.

Results

There was a trend for TTPG to increase in the placebo group (baseline 43.4 versus 48.4 mmHg at endpoint) and stay constant in the losartan group (baseline 42.8 versus 43.6 mmHg). More patients in the losartan group (50%) than in the placebo group (22%) showed a clinically meaningful reduction in TTPG at any timepoint; these effects seemed more marked in patients with higher baseline TTPG. There were no clear improvements in exercise capacity or symptoms.

Conclusion

In this 12-month pilot study, losartan 50 mg had no statistically significant beneficial effect on TTPG, exercise capacity or symptoms in pulmonary hypertension secondary to obstructive disease. A sub-group of patients with higher TTPG may benefit.
Assessing, treating and preventing community acquired pneumonia in older adults: findings from a community-wide survey of emergency room and family physicians
Authors: Krueger Paul , Loeb Mark , Kelly Caralyn , Edward H Gayle
Published: August 2005

Background

Respiratory infections, like pneumonia, represent an important threat to the health of older Canadians. Our objective was to determine, at a community level, family and emergency room physicians' knowledge and beliefs about community acquired pneumonia (CAP) in older adults and to describe their self-reported assessment, management and prevention strategies.

Methods

All active ER and family physicians in Brant County received a mailed questionnaire. An advance notification letter and three follow-up mailings were used to maximize physician participation rate. The questionnaire collected information about physicians' assessment, management, and prevention strategies for CAP in older adults (≥60 years of age) plus demographic, training, and practice characteristics. The analysis highlights differences in approaches between office-based and emergency department physicians.

Results

Seventy-seven percent of physicians completed and returned the survey. Although only 16% of physicians were very confident in assessing CAP in older adults, more than half reported CAP to be a very important health concern in their practices. In-service training for family physicians was associated with increased confidence in CAP assessment and more frequent use of diagnostic tests. Family physicians who reported always requesting chest x-rays were also more likely to request pulse oximetry (OR 5.6, 95% CI 1.40 to 22.5) and recommend both follow-up x-rays (OR 5.4, 95% CI 1.7 to 16.6) and pneumococcal vaccination (OR 3.4, 95% CI 1.1 to 10.0).

Conclusion

The findings of this study provide a snapshot of how non-specialists from a non-urban Ontario community assess, manage and prevent CAP in older adults and highlight differences between office-based and emergency department physicians. This information can guide researchers and clinicians in their efforts to improve the management and prevention of CAP in older adults.
Audio computer-assisted self-interviewing (ACASI) may avert socially desirable responses about infant feeding in the context of HIV
Authors: Waruru Anthony K , Nduati Ruth , Tylleskär Thorkild
Published: August 2005

Background

Understanding infant feeding practices in the context of HIV and factors that put mothers at risk of HIV infection is an important step towards prevention of mother to child transmission of HIV (PMTCT). Face-to-face (FTF) interviewing may not be a suitable way of ascertaining this information because respondents may report what is socially desirable. Audio computer-assisted self-interviewing (ACASI) is thought to increase privacy, reporting of sensitive issues and to eliminate socially desirable responses. We compared ACASI with FTF interviewing and explored its feasibility, usability, and acceptability in a PMTCT program in Kenya.

Methods

A graphic user interface (GUI) was developed using Macromedia Authorware® and questions and instructions recorded in local languages Kikuyu and Kiswahili. Eighty mothers enrolled in the PMTCT program were interviewed with each of the interviewing mode (ACASI and FTF) and responses obtained in FTF interviews and ACASI compared using McNemar's χ2 for paired proportions. A paired Student's t-test was used to compare means of age, marital-time and parity when measuring interview mode effect and two-sample Student's t-test to compare means for samples stratified by education level – determined during the exit interview. A Chi-Square (χ2test) was used to compare ability to use ACASI by education level.

Results

Mean ages for intended time for breastfeeding as reported by ACASI were 11 months by ACASI and 19 months by FTF interviewing (p < 0.001). Introduction of complementary foods at ≤3 months was reported more frequently by respondents in ACASI compared to FTF interviews for 7 of 13 complementary food items commonly utilized in the study area (p < 0.05). More respondents reported use of unsuitable utensils for infant feeding in ACASI than in FTF interviewing (p = 0.001). In other sensitive questions, 7% more respondents reported unstable relationships with ACASI than when interviewed FTF (p = 0.039). Regardless of education level, respondents used ACASI similarly and majority (65%) preferred it to FTF interviewing mainly due to enhanced usability and privacy. Most respondents (79%) preferred ACASI to FTF for future interviewing.

Conclusion

ACASI seems to improve quality of information by increasing response to sensitive questions, decreasing socially desirable responses, and by preventing null responses and was suitable for collecting data in a setting where formal education is low.
A comparison of six analytical disease mapping techniques as applied to West Nile Virus in the coterminous United States
Authors: Griffith Daniel A
Published: August 2005

West Nile Virus has quickly become a serious problem in the United States (US). Its extremely rapid diffusion throughout the country argues for a better understanding of its geographic dimensions. Both 2003 and 2004 percentages of deaths by numbers of reported human cases, for the 48 coterminous US states, are analyzed with a range of spatial statistical models, seeking to furnish a fuller appreciation of the variety of models available to researchers interested in analytical disease mapping. Comparative results indicate that no single spatial statistical model specification furnishes a preferred description of these data, although normal approximations appear to furnish some questionable implications. Findings also suggest several possible future research topics.
Role of early experience in ant enslavement: a comparative analysis of a host and a non-host species
Authors: Blatrix Rumsaïs , Sermage Claire
Published: August 2005

Background

Ants use the odour of the colony to discriminate nestmates. In some species, this odour is learned during the first days following emergence, and thus early experience has a strong influence on nestmate discrimination. Slave-making ants are social parasites that capture brood of other ant species to increase the worker force of their colony. After emerging in the slave-maker nest, slave workers work as if they were in their own colony. We tested the hypothesis that early experience allows the deception of commonly enslaved species, while non-host species use a different mechanism, which does not involve learning.

Results

Pupae of a host species, Temnothorax unifasciatus, and a non-host species, T. parvulus, were allowed to emerge in the presence of workers of one of two slave-maker species, Chalepoxenus muellerianus or Myrmoxenus ravouxi. When T. unifasciatus was exposed to slave-makers for 10 days following emergence, they were more aggressive towards their own sisters and groomed the slave-maker more. T. parvulus gave a less clear result: while workers behaved more aggressively towards their sisters when exposed early to C. muellerianus workers, this was not the case when exposed early to M. ravouxi workers. Moreover, T. parvulus workers allogroomed conspecific nestmates less than T. unifasciatus. Allogrooming activity might be very important for the slave-makers because they are tended by their slaves.

Conclusion

Our findings show that early experience influences nestmate discrimination in the ant T. unifasciatus and can account for the successful enslavement of this species. However, the non-host species T. parvulus is less influenced by the early environment. This might help to explain why this species is never used by social parasites.
An evaluation of the metabolic syndrome in a large multi-ethnic study: the Family Blood Pressure Program
Authors: Kraja Aldi T , Rao DC , Weder Alan B , Mosley Thomas H , Turner Stephen T , Hsiung Chao Agnes , Quertermous Thomas , Cooper Richard , Curb J David , Province Michael A
Published: August 2005

Background

The Family Blood Pressure Program is an ongoing, NHLBI-sponsored, multi-center program to study the genetic determinants of high blood pressure. The goal of this particular study was to study patterns of metabolic syndrome (MetS) in four ethnic groups: African Americans, Caucasians, Hispanics, and Asians.

Methods

A major part of participants in three networks GENOA, HyperGEN and SAPPHIRe were recruited mainly through hypertensive probands. MetS was defined as a categorical trait following the National Cholesterol Education Program definition (c-MetS). MetS was also characterized quantitatively through multivariate factor analyses (FA) of 10 risk variables (q-MetS). Logistic regression and frequency tables were used for studying associations among traits.

Results

Using the NCEP definition, the Hispanic sample, which by design was enriched for type 2 diabetes (T2D), had a very high prevalence of MetS (73%). In contrast, its prevalence in Chinese was the lowest (17%). In African Americans and Hispanics, c-MetS was more prevalent in women than in men. Association of c-MetS with type 2 diabetes (T2D) was prominent in the Hispanics and African Americans, less pronounced in the Whites and Japanese, (although still significant), and weakest in the Chinese sample.

Using FA without rotation, we found that the main factor loaded obesity (OBS) and blood pressure (BP) in African Americans; OBS and insulin (INS) in Hispanics, in Japanese, and in Whites; and OBS alone in Chinese. In Hispanics, Whites, and Japanese, BP loaded as a separate factor. Lipids in combination with INS also loaded in a separate factor. Using FA with Varimax rotation, 4 independent factors were identified: "Obesity-INS," "Blood pressure," "Lipids-INS," and "Central obesity." They explained about 60% of the variance present in the original risk variables.

Conclusion

MetS ethnic differences were identified. Ascertaining for hypertension or T2D increased the MetS prevalence in networks compared with the one in the US general population. Obesity was the most prominent risk factor contributing to both c-MetS and q-MetS. INS contributed in two important factors (obesity and lipids). The information imbedded into c-MetS trait /q-MetS factors scores can contribute in future research of the MetS, especially its utilization in the genetic analysis.
Celecoxib analogues disrupt Akt signaling, which is commonly activated in primary breast tumours
Authors: Kucab Jill E , Lee Cathy , Chen Ching-Shih , Zhu Jiuxiang , Gilks C Blake , Cheang Maggie , Huntsman David , Yorida Erika , Emerman Joanne , Pollak Michael , Dunn Sandra E
Published: August 2005

Introduction

Phosphorylated Akt (P-Akt) is an attractive molecular target because it contributes to the development of breast cancer and confers resistance to conventional therapies. Akt also serves as a signalling intermediate for receptors such as human epidermal growth factor receptor (HER)-2, which is overexpressed in 30% of breast cancers; therefore, inhibitors to this pathway are being sought. New celecoxib analogues reportedly inhibit P-Akt in prostate cancer cells. We therefore examined the potential of these compounds in the treatment of breast cancer. The analogues were characterized in MDA-MB-453 cells because they overexpress HER-2 and have very high levels of P-Akt.

Methods

To evaluate the effect of the celecoxib analogues, immunoblotting was used to identify changes in the phosphorylation of Akt and its downstream substrates glycogen synthase kinase (GSK) and 4E binding protein (4EBP-1). In vitro kinase assays were then used to assess the effect of the drugs on Akt activity. Cell death was evaluated by poly(ADP-ribose) polymerase cleavage, nucleosomal fragmentation and MTS assays. Finally, tumour tissue microarrays were screened for P-Akt and HER-2 expression.

Results

OSU-03012 and OSU-O3013 inhibited P-Akt and its downstream signalling through 4EBP-1 and GSK at concentrations well below that of celecoxib. Disruption of P-Akt was followed by induction of apoptosis and more than 90% cell death. We also noted that the cytotoxicity of the celecoxib analogues was not significantly affected by serum. In contrast, the presence of 5% serum protected cells from celecoxib induced death. Thus, the structural modification of the celecoxib analogues increased P-Akt inhibition and enhanced the bioavailability of the drugs in vitro. To assess how many patients may potentially benefit from such drugs we screened tumour tissue microarrays. P-Akt was highly activated in 58% (225/390) of cases, whereas it was only similarly expressed in 35% (9/26) of normal breast tissues. Furthermore, HER-2 positive tumours expressed high levels of P-Akt (P < 0.01), supporting in vitro signal transduction.

Conclusion

We determined that Celecoxib analogues are potent inhibitors of P-Akt signalling and kill breast cancer cells that overexpress HER-2. We also defined an association between HER-2 and P-Akt in primary breast tissues, suggesting that these inhibitors may benefit patients in need of new treatment options.
MicroRNA profiling of the murine hematopoietic system
Authors: Monticelli Silvia , Ansel K Mark , Xiao Changchun , Socci Nicholas D , Krichevsky Anna M , Thai To-Ha , Rajewsky Nikolaus , Marks Debora S , Sander Chris , Rajewsky Klaus , Rao Anjana , Kosik Kenneth S
Published: August 2005

Background

MicroRNAs (miRNAs) are a class of recently discovered noncoding RNA genes that post-transcriptionally regulate gene expression. It is becoming clear that miRNAs play an important role in the regulation of gene expression during development. However, in mammals, expression data are principally based on whole tissue analysis and are still very incomplete.

Results

We used oligonucleotide arrays to analyze miRNA expression in the murine hematopoietic system. Complementary oligonucleotides capable of hybridizing to 181 miRNAs were immobilized on a membrane and probed with radiolabeled RNA derived from low molecular weight fractions of total RNA from several different hematopoietic and neuronal cells. This method allowed us to analyze cell type-specific patterns of miRNA expression and to identify miRNAs that might be important for cell lineage specification and/or cell effector functions.

Conclusion

This is the first report of systematic miRNA gene profiling in cells of the hematopoietic system. As expected, miRNA expression patterns were very different between hematopoietic and non-hematopoietic cells, with further subtle differences observed within the hematopoietic group. Interestingly, the most pronounced similarities were observed among fully differentiated effector cells (Th1 and Th2 lymphocytes and mast cells) and precursors at comparable stages of differentiation (double negative thymocytes and pro-B cells), suggesting that in addition to regulating the process of commitment to particular cellular lineages, miRNAs might have an important general role in the mechanism of cell differentiation and maintenance of cell identity.
Functional FGFR4 Gly388Arg Polymorphism Predicts Prognosis in Lung Adenocarcinoma Patients
Authors: Spinola Monica , Leoni Vera , Pignatiello Carmen , Conti Barbara , Ravagnani Fernando , Pastorino Ugo , Dragani Tommaso A.
Published: August 2005

Purpose

Fibroblast growth factor receptor 4 (FGFR4) is a member of a family of transmembrane receptors with ligand-induced tyrosine kinase activity. The Gly388Arg polymorphism in the FGFR4 gene was reported to modulate cancer cell migration in vitro and to be associated with breast, colon, and prostate cancer prognostic parameters. The purpose of this study was to investigate the involvement of the FGFR4 polymorphism in lung tumorigenesis.

Patients and Methods

A case-control study was performed including 274 patients with histologically confirmed lung adenocarcinoma and 401 healthy control subjects from general population. mRNA expression analysis was carried out in healthy lung of cancer patients.

Results

Patients with the Arg/Arg or Gly/Arg genotype compared to those with a Gly/Gly genotype had an earlier age at cancer onset (median age, 60.2 v 63.4 years), higher proportion of poor clinical stage disease (hazard ratio [HR], 2.3; 95% CI, 1.4 to 3.9; P = .002), of nodal involvement (HR, 1.9; 95% CI, 1.1 to 3.2; P = .027), or of short-term survivors (HR, 1.6; 95% CI, 1.1 to 2.3; P = .008). In healthy lungs, FGFR4 did not show allele-specific expression and mRNA levels were not associated with genotype.

Conclusion

This study suggests that FGFR4 Gly388Arg polymorphism may predict prognosis in lung adenocarcinoma.
Promoter Polymorphism of the CD14 Endotoxin Receptor Gene Is Associated With Biliary Atresia and Idiopathic Neonatal Cholestasis
Authors: Shih Hsiang-Hung , Lin Tsun-Mei , Chuang Jiin-Haur , Eng Hock-Liew , Juo Suh-Hang Hank , Huang Fu-Chen , Chen Chao-Long , Chen Huey-Ling
Published: August 2005

Objective.To investigate whether single-nucleotide polymorphisms in the promoter regions of endotoxin-responsive genes CD14 and tumor necrosis factor-α (TNF-α) are associated with biliary atresia (BA) and idiopathic neonatal cholestasis (INC).

Methods.We obtained genomic DNA from 90 patients with established diagnosis of BA and 28 patients with INC. Forty-two adult patients with hepatitis B–related cirrhosis and 143 healthy children served as control populations. The genotypes of CD14/C(−159)T and TNF-α/G(−308)A (G allele, TNF*1; A allele, TNF*2) were determined by using a restriction enzyme–based assay. Plasma soluble CD14 levels were determined in different disease stages and genotypes of BA.

Results.The frequencies of T allele and T/T homozygosity of the CD14/−159 promoter polymorphism were significantly higher in patients with BA (T allele: 61.7%; T/T genotype: 42.2%) and in patients with INC (T allele: 67.9%; T/T genotype: 53.6%) but not in control populations. Decrease of plasma soluble CD14 from the early stage of BA when the patients received a Kasai operation to the late stage of liver cirrhosis was observed in carriers of the T/T and T/C genotypes but not in carriers of the C/C genotype. The TNF-α/−308 promoter polymorphisms (TNF*1 and TNF*2) were not associated with BA.

Conclusion.These findings show that the single-nucleotide polymorphism at CD14/−159 is associated with the development of BA and INC. Endotoxin susceptibility may play a role in the pathogenesis of infantile cholestasis.