bluuebunny/crossref_metadata_2025 huggingface dataset:
Weight changes over time in adults treated with the oral or depot formulations of olanzapine: a pooled analysis of 86 clinical trials
Authors: Millen Brian A , Campbell Giedra M , Beasley Charles M
Published: June 2010

Several analytical approaches were used to characterize time progression of weight changes observed in adults treated with olanzapine from a 12,425-patient database of 86 studies of oral and depot formulations of olanzapine (mean modal dose 13.3 mg/day). Descriptive mean profile plots for completer and modified completer groups showed weight increasing throughout each observed period, with apparent slowing in rate of change after 3 or 4 months. Mixed-effects model repeated measures analyses also showed that weight increased most rapidly early in treatment and slowed within 2 to 4 months. The slowing in rate of change was greatest for patients obese at baseline and least for patients underweight at baseline. This pattern was also observed in a nonparametric regression-based profile. Based on visual inspection of profile plots, 2, 3, 4, and 5 months were postulated as potential ‘change points’ beyond which rate of increase might slow, and the proportions of patients whose slope after each change point was ≤90% of the slope before change point were calculated. Over 85% of patients who gained weight showed slowing rate of weight change after each postulated change point. Potential consequences of weight gain should be considered prior to starting olanzapine. Olanzapine-treated patients should receive regular weight monitoring.
Packing Heat in the Tar Heel State: A County-Level Assessment of Concealed Carry Permits
Authors: Thompson Joel A. , Stidham Ronald
Published: June 2010

This study analyzes variations in the rates at which North Carolina citizens apply for and are issued concealed carry permits (CCPs). Various theories, primarily those related to fear of/response to crime, demographic/geographic factors, and social learning theories of gun ownership, guide the analysis. Generally speaking, the authors find little support for socioeconomic and demographic explanations of CCPs in North Carolina. In addition, the authors find no support for the notion that violent or property crimes, or changes in these crimes over time, affect CCP policy. The authors do find some evidence that change in minority population (Black, but not Hispanic) is significantly related to permitting. In North Carolina, there is support for a cultural model of CCPs. Both the political conservatism and the proportion of hunters in the population (our indicator of a cultural norm that values and cherishes gun ownership) are consistently related to permitting. The authors conclude that the combination of political conservatism and socialization into a hunting/ gun-owning culture are more important than socioeconomic variables in explaining CCPs.
Divine Justice: The Relationship Between Images of God and Attitudes Toward Criminal Punishment
Authors: Bader Christopher D. , Desmond Scott A. , Carson Mencken F. , Johnson Byron R.
Published: June 2010

Some have argued that moralistic considerations trump other factors in determining attitudes toward criminal punishment. Consequently, recent research has examined how views of God influence sentiments regarding criminal punishment. Using the Baylor Religion Survey (BRS) 2005, we find that (a) angry and judgmental images of God are significant predictors of punitive attitudes regarding criminal punishment and the death penalty and (b) images of God as loving and engaged in the world are not consistently significant predictors of attitudes toward criminal punishment, once measures of God’s perceived anger and judgment are considered.
Assessment of the Municipal Solid Waste & Status of Implementation of Municipal Solid Waste (Management & Handling), Rules, 2000 in the State of Madhya Pradesh, 2008 - A case study
Authors: Lal Patel Munna , Jain Rajnikant , Saxena Alok
Published: June 2010

The municipal solid waste (MSW), generated from different activities in the township and city areas is a subject of deep concern for its proper management. The improper management of the MSW is a major cause for water, air and soil pollution. The population explosion and sustained drive for economic progress and development have resulted in a remarkable increase/ change in quantity and characteristics of MSW generation over the last 20 years. The local bodies are responsible for the management of the MSW in the State. The Municipal Solid Waste (Management & Handling), Rules, 2000 came into force from the date of its publication in the official Gazette of India and are applicable to every local body responsible for the proper management of the MSW in the State. The status report of the implementation of the Municipal Solid Waste (Management & Handling), Rules, 2000 in the State of Madhya Pradesh, is prepared as per the MOU signed by the State Pollution Control Board with the Central Pollution Control Board, New Delhi. The necessary data for the preparation of the report, collected from the respective local bodies through the regional offices of the Board during the period February to December 2008. There are 342 local bodies (municipal corporations, 14; municipal committees or municipalities, 86; Nagar Panchyats, 237; and cantonment boards, 5) responsible for the implementation of the MSW, in the State. It is estimated that around 4500 Mt day—1 MSW is generated from all the 342 local bodies. The local bodies of the State are not well equipped for the proper management of the MSW. A total of 323 local bodies has identified land for the development of the landfill sites as per the provisions of the Rules but only 90 local bodies acquired the same. As an outcome of this assessment, the local bodies are not financially and technically capable for the proper implementation of the Rules. The collection of the waste is around 60—70%. This status report will serve as an important tool for further planning regarding generation of information and knowledge required for developing strategies, techniques and methodologies for better environmental management in the State.
Estimation of Peak Heat Release Rate of a Forest Fuel Bed in Outdoor Laboratory Conditions
Authors: Madrigal J. , Guijarro M. , Hernando C. , Díez C. , Marino E.
Published: June 2010

Experimental tests were carried out with an adapted bench-scale mass loss calorimeter (MLC) and also in an outdoor wind tunnel to estimate the heat release rate (HRR) of a forest fuel bed. The MLC apparatus uses a calibrated thermopile to quantify the HRR, as an alternative to the classical measurement of oxygen consumption due to combustion. Additional calibration of thermocouples to measure gas temperatures enabled estimation of HRR in experimental burnings conducted in the wind tunnel. The results showed a reasonable agreement between peak HRR (PHRR) values obtained in the MLC and in the wind tunnel, and also demonstrated that PHRR was significantly affected by the wind speed and the rate of spread. The proposed procedure is potentially useful as an initial step in monitoring HRR in outdoor forest fire experiments.
Peer assessment in tertiary level singing: Changing and shaping culture through social interaction
Authors: Latukefu Lotte
Published: June 2010

In 2008, peer assessment was introduced into the singing component of a tertiary level undergraduate creative arts performance course within an Australian regional university. The project investigated what effect changing the role of the actor/singer in an assessment has on the culture of the course as well as individual development of graduate qualities, such as critical thinking and responsibility. It also looked at what process was involved in order to integrate peer assessment into the subject, and what kind of support was needed to achieve this. Results suggested that students saw themselves as agents of their own assessment activities by taking control of assessment, and that having to think critically about other student performances made them reflect on how effective their own performances were.
Disparities in access to care among asthmatic children in relation to race and socioeconomic status
Authors: Piper Crystal N. , Glover Saundra , Elder Keith , Baek Jong-Deuk , Wilkinson Larrell
Published: June 2010

Asthma is one of the leading chronic illnesses among children in the United States. International epidemiological studies have also shown asthma prevalence is an increasing problem. The objective of this study was to examine the correlates of access to care among asthmatic children age 0—17 in the United States. This is a retrospective study and secondary data analysis of the 2000 National Health Interview Survey. Parametric testing using univariate, bivariate, and multivariate analyses were performed to examine health care utilization among children with asthma in the United States. It was found that Black children were highly associated with not visiting a general doctor in the past 12 months (OR 0.47; 95% CI 0.30, 0.75). Uninsured asthmatic children were associated with the risk of not seeing a general doctor in the past 12 months (OR 0.40; 95% CI 0.23, 0.69). Our study findings indicate disparities among Black children with asthma and their ability to access appropriate health care services. Additional studies are required to identify factors that contribute to the temporal trends in asthma and country of origin.
Bone density, balance and quality of life of postmenopausal women taking alendronate participating in different physical activity programs
Authors: Borba-Pinheiro Cláudio Joaquim , de Alencar Carvalho Mauro César Gurgel , Lima da Silva Nádia Souza , Janotta Drigo Alexandre , Pereira Bezerra Jani Cléria , Dantas Estélio Henrique Martin
Published: June 2010

Background: The objective of this study was to determine the effects of different physical activity (PA) programs on bone density, balance and quality of life of postmenopausal women taking concomitant alendronate. A quasi-experimental study was conducted with 35 volunteers divided into four groups: practitioners of resistance training (RTG, n = 9, 49.8±4.2 years), judo (JUG, n = 11, 52.2±5.3 years), water aerobics (WAG, n = 8, 57.1±7.4 years) and the control group (CG, n = 7, 53.8±4.4 years).

Methods: The following assessment tools were used: bone mineral density (BMD) measured by dual X-ray absorptiometry of the spine and proximal femur, the ‘Osteoporosis Assessment Questionnaire’ (OPAQ) and the ‘Static Balance Test with Visual Control’. The physical activities were planned for 12 months in cycles with different intensities. A two-way analysis of variance (ANOVA) was used for analysis between groups, and a Scheffé post-hoc test was used for multiple comparisons.

Results: The multiple comparisons results showed that the RTG and JUG groups were significantly more efficient in the variables studied, including: lumbar BMD (Δ% = 6.8%, p = 0.001), balance (Δ% = 21.4%, p = 0.01), OPAQ (Δ% = 9.1%, p = 0.005) and lumbar BMD (Δ% = 6.4%, p = 0.003), balance (Δ% = 14%, p = 0.02) and OPAQ (Δ% = 16.8%, p = 0.000) compared with the CG. Furthermore, the RTG (Δ% = 4.8%, p = 0.02) was significantly better than the WAG for the neck of femur BMD, and the JUG (Δ% = 16.8, p = 0.0003) also demonstrated superiority to the WAG in the OPAQ.

Conclusions: The physical activities studied appear to improve BMD, balance and quality of life of postmenopausal women taking a bisphosphonate. In this small sample, the RTG and the JUG groups were superior to the other groups.
The cell polarity PTK7 receptor acts as a modulator of the chemotherapeutic response in acute myeloid leukemia and impairs clinical outcome
Authors: Prebet Thomas , Lhoumeau Anne-Catherine , Arnoulet Christine , Aulas Anaïs , Marchetto Sylvie , Audebert Stéphane , Puppo Francesca , Chabannon Christian , Sainty Danielle , Santoni Marie-Josée , Sebbagh Michael , Summerour Virginia , Huon Yannick , Shin Won-Sik , Lee Seung-Taek , Esterni Benjamin , Vey Norbert , Borg Jean-Paul
Published: June 2010

The pseudo tyrosine kinase receptor 7 (PTK7) is an orphan tyrosine kinase receptor assigned to the planar cell polarity pathway. It plays a major role during embryogenesis and epithelial tissue organization. Here we found that PTK7 is also expressed in normal myeloid progenitors and CD34+ CD38− bone marrow cells in humans. We performed an immunophenotyping screen on more than 300 patients treated for hematologic malignancies. We demonstrated that PTK7 is expressed in acute myeloid leukemia (AML) and is mostly assigned to granulocytic lineage differentiation. Patients with PTK7-positive AML are more resistant to anthracycline-based frontline therapy with a significantly reduced leukemia-free survival in a multivariate analysis model. In vitro, expression of PTK7 in cultured leukemia cells promotes cell migration, cell survival, and resistance to anthracycline-induced apoptosis. The intracellular region of PTK7 is required for these effects. Furthermore, we efficiently sensitized primary AML blasts to anthracycline-mediated cell death using a recombinant soluble PTK7-Fc protein. We conclude that PTK7 is a planar cell polarity component expressed in the myeloid progenitor compartment that conveys promigratory and antiapoptotic signals into the cell and that represents an independent prognosis factor of survival in patients treated with induction chemotherapy.
AMPK α2 subunit is involved in platelet signaling, clot retraction, and thrombus stability
Authors: Randriamboavonjy Voahanginirina , Isaak Johann , Frömel Timo , Viollet Benoit , Fisslthaler Beate , Preissner Klaus T. , Fleming Ingrid
Published: June 2010

The adenosine monophosphate (AMP)–activated protein kinase (AMPK) is a regulator of energy balance at the cellular and whole-body levels, but little is known about the role of AMPK in platelet activation. We report that both the α1 and α2 AMPK isoforms are expressed by human and murine platelets and that thrombin elicits the phosphorylation of AMPKα as well as the upstream kinase, liver kinase B1 (LKB1). In human platelets, the kinase inhibitors iodotubercidin and compound C significantly inhibited thrombin-induced platelet aggregation and clot retraction without affecting the initial increase in [Ca2+]i. Clot retraction was also impaired in platelets from AMPKα2−/− mice but not from wild-type littermates or AMPKα1−/− mice. Moreover, rebleeding was more frequent in AMPKα2−/− mice, and the FeCl3-induced thrombi formed in AMPKα2−/− mice were unstable. Mechanistically, AMPKα2 was found to phosphorylate in vitro the Src-family kinase, Fyn, and isoform deletion resulted in the attenuated threonine phosphorylation of Fyn as well as the subsequent tyrosine phosphorylation of its substrate, β3 integrin. These data indicate that AMPKα2—by affecting Fyn phosphorylation and activity—plays a key role in platelet αIIbβ3 integrin signaling, leading to clot retraction and thrombus stability.
An effective approach for generating a three-Cys2His2 zinc-finger-DNA complex model by docking
Authors: Chou Chun-Chi , Rajasekaran M , Chen Chinpan
Published: June 2010

Background

Determination of protein-DNA complex structures with both NMR and X-ray crystallography remains challenging in many cases. High Ambiguity-Driven DOCKing (HADDOCK) is an information-driven docking program that has been used to successfully model many protein-DNA complexes. However, a protein-DNA complex model whereby the protein wraps around DNA has not been reported. Defining the ambiguous interaction restraints for the classical three-Cys2His2 zinc-finger proteins that wrap around DNA is critical because of the complicated binding geometry. In this study, we generated a Zif268-DNA complex model using three different sets of ambiguous interaction restraints (AIRs) to study the effect of the geometric distribution on the docking and used this approach to generate a newly reported Sp1-DNA complex model.

Results

The complex models we generated on the basis of two AIRs with a good geometric distribution in each domain are reasonable in terms of the number of models with wrap-around conformation, interface root mean square deviation, AIR energy and fraction native contacts. We derived the modeling approach for generating a three-Cys2His2 zinc-finger-DNA complex model according to the results of docking studies using the Zif268-DNA and other three crystal complex structures. Furthermore, the Sp1-DNA complex model was calculated with this approach, and the interactions between Sp1 and DNA are in good agreement with those previously reported.

Conclusions

Our docking data demonstrate that two AIRs with a reasonable geometric distribution in each of the three-Cys2His2 zinc-finger domains are sufficient to generate an accurate complex model with protein wrapping around DNA. This approach is efficient for generating a zinc-finger protein-DNA complex model for unknown complex structures in which the protein wraps around DNA. We provide a flowchart showing the detailed procedures of this approach.
Identification of scaffold/Matrix Attachment (S/MAR) like DNA element from the gastrointestinal protozoan parasite Giardia lamblia
Authors: Padmaja Sushma S , Lakshmanan Jagannathan , Gupta Ravi , Banerjee Santanu , Gautam Pennathur , Banerjee Sulagna
Published: June 2010

Background

Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene organization and regulation of gene expression, they have not been reported in protists like Giardia. Several tools have been discovered and formulated to predict S/MARs from a genome of a higher eukaryote which take into account a number of features. However, the lack of a definitive consensus sequence in S/MARs and the randomness of the protozoan genome in general, make it a challenge to predict and identify such sequences from protists.

Results

Here, we have analysed the Giardia genome for the probable S/MARs predicted by the available computational tools; and then shown these sequences to be physically associated with the nuclear matrix. Our study also reflects that while no single computational tool is competent to predict such complex elements from protist genomes, a combination of tools followed by experimental verification is the only way to confirm the presence of these elements from these organisms.

Conclusion

This is the first report of S/MAR elements from the protozoan parasite Giardia lamblia. This initial work is expected to lay a framework for future studies relating to genome organization as well as gene regulatory elements in this parasite.
Gastric cancer is associated with NOS2-954G/C polymorphism and environmental factors in a Brazilian population
Authors: Jorge Yvana C , Duarte Marcia C , Silva Ana E
Published: June 2010

Background

Gastric cancer can progress from a chronic inflammation of the gastric mucosa resulting fromHelicobacter pyloriinfection that activates the inflammatory response of the host. Therefore, polymorphisms in genes involved in the inflammatory response, such as inducible nitric oxide synthase (NOS2), have been implicated in gastric carcinogenesis. The aim of this study was to evaluate the association ofNOS2polymorphisms Ser608Leu (rs2297518) in exon 16, -954G/C and -1173C/T, both in the promoter region, with gastric cancer and chronic gastritis and the association of cancer with risk factors such as smoking, alcohol intake andH. pyloriinfection.

Methods

We conducted a population-based case-control study in 474 Southeast Brazilian individuals (150 with gastric cancer, 160 with chronic gastritis, and 164 healthy individuals), in which we performedNOS2genotyping by PCR-RFLP.

Results

SNP Ser608Leu was not associated with risk of chronic gastritis or gastric cancer. The polymorphic allele -1173T was not found in the studied population. However, the frequency of -954GC+CC genotypes was significantly higher (p < 0.01) in the cancer group (48.7%) than in both the gastritis (28.1%) and the control (29.9%) groups. Multivariate logistic regression showed that theNOS2SNP -954G/C was associated with higher risk of gastric cancer (OR = 1.87; 95% CI = 1.12-3.13). We also observed an association with risk factors such as smoking and alcohol intake in both the gastric cancer (OR = 2.68; 95% CI = 1.58-4.53; OR = 3.60; 95% CI = 2.05-6.32, respectively) and the chronic gastritis (OR = 1.93; 95% CI = 1.19-3.13; OR = 2.79; 95% CI = 1.55-5.02, respectively) groups. This is the first report of increased risk of gastric cancer in association with the -954G/C polymorphism. These findings show that several polymorphisms in the promoter region of theNOS2gene may contribute to the susceptibility to gastric cancer.

Conclusions

PolymorphismNOS2-954 G/C, along with alcohol intake and tobacco smoking, is associated with gastric cancer. However, theNOS2Ser608Leu polymorphism was not associated with gastric carcinogenesis. TheNOS2-1173C/T polymorphism was absent in the studied population.
Long persistence of EV71 specific nucleotides in respiratory and feces samples of the patients with Hand-Foot-Mouth Disease after recovery
Authors: Han Jun , Ma Xue-Jun , Wan Jun-Feng , Liu Ying-Hui , Han Yan-Ling , Chen Cao , Tian Chan , Gao Chen , Wang Miao , Dong Xiao-Ping
Published: June 2010

Background

EV71 is associated with the fatal cases of brain stem encephalitis during large HFMD outbreaks from 1998 to 2008. EV71 may continuously shed from upper respiratory tracts and feces of HFMD patients for relatively long time after recovery. However, the persistence of viruses in the patients' secretions and excretions is not clear.

Methods

Serial throat swabs and feces of 34 definitely diagnosed patients, including 30 mild cases and 4 severe cases, were traced and collected with the interval of 2 to 4 days for up to 32 and 48 days, respectively, and tested by a nested RT-PCR.

Results

The EV-71 specific sequences were identified by a Nested RT-PCR in all specimens of 0-4 days, and 5-8 days. The positive rates of EV71 in throat swabs dropped markedly to 42.86% during 9-12 days, and maintained at 20-30% during 13-24 days, while that in feces reduced to 71.43% during 9-12 days, and maintained roughly 20% till 37-40 days. EV71 nucleotide of 36.36% cases disappeared simultaneously both in throats and feces, 39.39% cases showed longer persistence of EV71 nucleotides in feces, and 21.21% were longer in throats. The longest duration of shedding observed was 24 days for throat swabs and 42 days for fecal specimens.

Conclusions

EV71 shedding from respiratory tract may continue for nearly four weeks after onset, but its excretion through feces can persist more than five weeks.
Health-related quality of life in glioma patients in China
Authors: Cheng Jin-xiang , Liu Bo-lin , Zhang Xiang , Lin Wei , Zhang Yong-qiang , Liu Wei-ping , Zhang Jian-ning , Lin Hong , Wang Rui , Yin Hong
Published: June 2010

Background

Health-related quality of life (HRQOL) has been increasingly emphasized in cancer patients. There are no reports comparing baseline HRQOL of different subgroups of glioma patients prior to surgery.

Methods

HRQOL assessments by the standard Chinese version of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 (EORTC QLQ-C30, version 3.0), the Mini-Mental State Examination and Karnofsky Performance Status were obtained from glioma patients prior to surgery.

Results

Ninety-two pathologically confirmed glioma patients were recruited. There were 84.8% patients with emotional impairment, 75% with social and cognitive impairment, 70.7% with physical impairment, and 50% with role impairment. Eighty-two percent of patients reported fatigue symptoms, 72.8% reported pain, 50% reported appetite loss, 39.1% reported insomnia, and 36.9% reported nausea/vomiting, whereas other symptoms (dyspnea, diarrhea, constipation) in the QLQ-C30 were reported by fewer than 30% of patients. Fatigue and pain symptoms and all "functioning" scales were strongly correlated with global health status/quality of life (QoL). Fatigue was strongly related to all functioning scales, pain, appetite loss, and global health status/QoL. No difference in baseline HRQOL prior to surgery was reported between females and males, among different lesion locations, or between normal- and abnormal-cognition subgroups of glioma patients. Age, KPS, WHO grade, and tumor recurrence significantly affected HRQOL in glioma patients.

Conclusions

These data provided the baseline HRQOL in glioma patients prior to surgery in China. Most pre-surgery glioma patients indicated emotional, social, cognitive, physical, and role impairment. Fatigue, pain, appetite loss, insomnia, and nausea/vomiting were common in these patients. The fatigue and pain symptoms and all types of functioning strongly affected global health status/QoL. Old age, worse performance status, WHO grade IV and tumor recurrence had deleterious effects on HRQOL.
What 'outliers' tell us about missed opportunities for tuberculosis control: a cross-sectional study of patients in Mumbai, India
Authors: Pradhan Anagha , Kielmann Karina , Gupte Himanshu , Bamne Arun , Porter John DH , Rangan Sheela
Published: June 2010

Background

India's Revised National Tuberculosis Control Programme (RNTCP) is deemed highly successful in terms of detection and cure rates. However, some patients experience delays in accessing diagnosis and treatment. Patients falling between the 96th and 100th percentiles for these access indicators are often ignored as atypical 'outliers' when assessing programme performance. They may, however, provide clues to understanding why some patients never reach the programme. This paper examines the underlying vulnerabilities of patients with extreme values for delays in accessing the RNTCP in Mumbai city, India.

Methods

We conducted a cross-sectional study with 266 new sputum positive patients registered with the RNTCP in Mumbai. Patients were classified as 'outliers' if patient, provider and system delays were beyond the 95th percentile for the respective variable. Case profiles of 'outliers' for patient, provider and system delays were examined and compared with the rest of the sample to identify key factors responsible for delays.

Results

Forty-two patients were 'outliers' on one or more of the delay variables. All 'outliers' had a significantly lower per capita income than the remaining sample. The lack of economic resources was compounded by social, structural and environmental vulnerabilities. Longer patient delays were related to patients' perception of symptoms as non-serious. Provider delays were incurred as a result of private providers' failure to respond to tuberculosis in a timely manner. Diagnostic and treatment delays were minimal, however, analysis of the 'outliers' revealed the importance of social support in enabling access to the programme.

Conclusion

A proxy for those who fail to reach the programme, these case profiles highlight unique vulnerabilities that need innovative approaches by the RNTCP. The focus on 'outliers' provides a less resource- and time-intensive alternative to community-based studies for understanding the barriers to reaching public health programmes.
Fatigue Strength of Cast Crankshafts
Authors: Mills H. R. , Love R. J.
Published: June 2010

The paper gives the results of a systematic investigation into the effects of the proportions of a cast crankshaft on its bending fatigue strength. A single-throw shaft of 4½ inches diameter was chosen as likely to give information useful to the builders of small stationary engines as well as automobile engines, and the different dimensions were varied one at a time over a range which covered the usual practical proportions. In addition, to obtain some information on a possible scale effect, tests on a geometrically similar shaft of 2¼ inches diameter were included. It is considered that, with a few exceptions which are indicated in the paper, most of the conclusions from these tests will apply equally to forged and cast crankshafts. The paper refers also to tests made on a number of different cast-iron and cast-steel crankshafts of the same design, to determine, from the point of view of fatigue strength, their merits as crankshaft materials, and to find out to what extent the fatigue strength of the finished crankshaft can be predicted from the usual mechanical tests on the materials.
The Development of Transport and Commercial Vehicles in Bristol
Authors: Hallpike A. W.
Published: June 2010

Considering the fact that at the present time there are no tramcars operating in Bristol, it may seem a little odd to find a modern transport undertaking still using the somewhat quaint-sounding title, “Bristol Tramways and Carriage Co., Ltd.” The reason, together with the history of the company from its earliest days up to the present, is dealt with in the paper, which is illustrated with lantern slides, made from pictures of historical interest kept in the company's archives.

The story begins from 1870 and tells of the early difficulties confronting the planners; the scenes in the city when the first horse-drawn tramcars ran along the flag-decorated streets in 1875; the acquisition and operation of a fleet of cabs painted blue with red wheels, the drivers wearing top hats with braided bands and full-liveried top coats; the electrification of the tramway system and the supersession of the horses; and then on to the motor era which, as far as Bristol was concerned, commenced in 1906.

The various models of motor coaches and omnibuses designed and produced, including the four-tonner of 1913, the Redrup axial wobble-plate engine of 1935, the present-day models such as the underfloor engine single-decker and the low double-decker, and heavy goods vehicles are mentioned.

Details of the company's overall development during its eighty-three years' history are given in the narrative, and something is told of the work done during two world wars.
Trailers and Semi-Trailers
Authors: Marenbon Arthur
Published: June 2010

The author deals briefly with the main functional uses of trailers and semi-trailers and with some of the factors which govern their construction and design. Typical British, European, and Transatlantic models are described and contrasted.

Particular attention is paid to steering characteristics and the development of tracking models. Formulae for calculating the normal “cut-in” have been evolved.

Consideration is given to semi-trailer fifth wheel design and mounting position, trailer turntable and drawbar couplings, and factors which influence “snaking”.

Various springing and wheel arrangements are described as well as low and easy loading models. Some aspects of the design of trailers for carrying very heavy loads are considered, and details are given of some notable heavy duty vehicles.

Further sections of the paper deal with passenger carriers, specialized forms of trailers for road and rail co-ordination, and the multiplicity of uses to which trailers are put in present-day transport.
The Mathematical Theory of the Snaking of Two-wheeled Trailers, with Practical Rules and Devices for Preventing Snaking
Authors: Williams D.
Published: June 2010

It is well known that a prime essential in bringing about unstable motion in any elastic system is the presence of at least two degrees of freedom. A trailer and its towing vehicle constitute a mechanical system with a number of degrees of freedom, and a main feature of the present problem is the necessity for deciding which are essential factors in the unstable motion and which are trivial or merely incidental. The idea of including all the possible degrees of freedom in the dynamical equations, thereby obtaining a general solution in which the part played by the several parameters can be seen, is quite impracticable.

In Part I of the paper the results obtained from the mathematical analysis of the problem are given and discussed. There is a general agreement with practical experience. Part II contains the detailed analysis on which the conclusions in Part I are based.

It is emphasized that the main purpose of the analysis is not to enable calculations to be made of the precise critical speed at which snaking begins for any particular combination of tractor and trailer, but to discover what factors make for stability and for instability, and how to design for immunity from snaking at all speeds.
Injection Characteristics and Diesel Knock
Authors: Davies A. J.
Published: June 2010

Diesel knock arises from vibrations set up in the engine structure by varying stresses resulting from the changing cylinder pressure during the combustion phase of the cycle. An elementary study of the response of an elastically supported mass to a varying applied force illustrates the connexion between the form of the cylinder-pressure/time relation and the excitation of vibrations in the engine. The dependence of the form of this relation upon fuel properties and injection characteristic is discussed with particular reference to pilot injection systems. Experiments with such systems are described and illustrated by some records of engine vibration and cylinder pressure diagrams. Preliminary quantitative data as to the effect of quantity and timing of the pilot charge on the cylinder pressure diagram are reported. The influence of these factors on ignition delay and maximum rate of increase of cylinder pressure is examined. Under the prevailing experimental conditions, the latter is seen to decrease as the quantity of pilot charge is increased and evidence that this phenomenon is primarily responsible for the reduction of Diesel knock is adduced.
Life Assessment Tests for Commercial Vehicles
Authors: Alden John
Published: June 2010

The paper describes methods used during the testing of prototype commercial vehicles, including lorries, goods vans, and passenger-carrying coaches, to determine that the durability of the component parts is in every way satisfactory. The paper describes also the reasons why these methods came to be applied, and the nature of the results obtained.

Considerable detail is given of the method developed to accelerate the life testing of commercial vehicles by continuously driving them over specially designed bumpy or rough road surfaces, here called a rough track. Testing of this nature, of which the author has had ten years' experience, is of particular interest in view of the growing use by manufacturers, of both commercial vehicles and passenger cars, of such test tracks as the Belgian pavé at the Motor Industry Research Association Proving Ground at Nuneaton. The importance of this type of testing ha the development of sufficient durability to meet typical export requirements, especially when operating on corrugated roads, is emphasized.

Methods of duration testing on normal British roads are also given and rig testing is discussed together with details of one typical test rig—a wheel fatigue test machine.

The meaning and interpretation of testing in terms of the required durability and acceptability in service is also explained.

The MS. of this paper was received at the Institution on 9th January 1952. For the Minutes of the meeting in London, on 13th January 1953, at which this paper was presented, see p. 90.
The Manufacture and Properties of Automobile Suspension Springs
Authors: Dadswell C. J. , Russell J. E. , Fielding R.
Published: June 2010

In this paper is given a description of the manufacture of laminated, coil and torsion bar springs, together with some notes on the various defects which may arise and the precautions taken to prevent them occurring.

The mechanical properties of springs are discussed, and tentative design data are presented.

Consideration is given to shot peening and scragging, and an analysis is presented of the internal stresses caused by these processes.

The MS. of this paper was received at the Institution on 23rd May 1953. For the Minutes of the meeting in Sheffield, at which this paper was presented, see p. 118.
Tyre Characteristics as Applicable to Vehicle Stability Problems
Authors: Joy T. J. P. , Hartley D. C.
Published: June 2010

The authors define the characteristics of a pneumatic tyre which affect the handling, or stability, of a car, and briefly describe a machine which was developed to measure these characteristics.

The results are given of various experiments showing the effect of several factors on the characteristics; the applicability of these results to the behaviour of a tyre on the road is also discussed.

Briefly defining oversteer and understeer, the authors outline a proposed method for directly determining the handling performance of a car while it is still in the drawing board stage. It is pointed out that this will only apply to steady conditions and some of the factors affecting transient behaviour are discussed. In particular, the importance of the self-aligning torque is stressed.

The problem of breakaway is mentioned and doubts are cast on the applicability of the machine results to high-speed cornering, or racing; the technique of drifting a car round a corner is discussed.

The MS. of this paper was received at the Institution on 17th November 1953, and in its revised form on 11th January 1954. For the report of the meeting in London, at which this paper was presented, see p. 134.
Automobiles and Petroleum: Past, Present, and Future
Authors: Broeze J. J.
Published: June 2010

The MS. of this paper was received at the Institution on 14th May 1954. For the report of the meeting in Delft, at which this paper was presented, see p. 146.
Some Aspects of the Design and Performance of Small Diesel Engines
Authors: Millington B. W. , Howarth M. H.
Published: June 2010

In this paper the questions and problems associated with the design of small Diesel engines are discussed. The relative merits of air- and water-cooled systems are considered, and the design principles of a small four-stroke water-cooled Diesel engine are evolved. After dealing with general design aspects the authors consider the related problems of fuel injection and combustion, referring to the influence of fuel injection components. The paper concludes with a section on future development in which the authors discuss the smallest economic cylinder size and methods of achieving more power, greater simplicity and increased thermal efficiency.
A Survey of Fifty Years of Transmission Development
Authors: Stott T. C. F.
Published: June 2010

Since the inception of the automobile, steady development has resulted in the evolution of the transmission unit from the manually operated open sliding gear train to the modern compact fully automatic transmission. In this address the author has endeavoured to trace the various stages through which this development has passed. Throughout the period the general tendency has been towards a more compact unit and all have contributed, to some degree, in reducing to the minimum the skill required in gear changing. Space has not permitted of a detailed examination of all the mechanisms that have been produced and only a brief review of the general trend has been possible. In addition to the better known developments, descriptions have also been included of some of the more unorthodox designs that were in production for many years.

In Great Britain the syncromesh gear box is firmly established for both cars and trucks but in the United States of America this type of transmission is now almost obsolete and the automatic transmission is practically in universal use. The two main types of automatic transmission—viz. the automatically-changed four-speed fixed ratio unit used in conjunction with a fluid coupling and the infinitely variable ratio hydraulic torque converter—are dealt with in some detail as an appreciation of the present state of the art in the U.S.A. is indicative of the direction that future development in Great Britain will almost inevitably take.
Design and Application of Thermostats to the Cooling System of the Internal-Combustion Engine
Authors: Blazey S. H.
Published: June 2010

The history of the thermostat is shown and the way in which effective engine-coolant temperature control has been obtained through the years.

The main reasons for the use of thermostats are as follows:

(1) Lower engine wear. (2) Improved thermal efficiency. (3) Requirements of the modern car heater.

The basic design requirements for the ideal engine thermostat are then enumerated. The paper discusses how near the modern thermostat comes to these requirements. The poppet type and butterfly type valve are used for thermostats, the advantages and disadvantages of each type being discussed. The main problem is dirt, which becomes trapped in the valve seating, and increases the warm-up time of the cooling system.

The design features of the bellows type and wax type thermostat, and the fillings used in the bellows type are discussed. The damping of vibration periods by hydraulic and friction methods are shown. The wax type thermostat has gained popularity because of its insensitivity to pressure when the coolant system is pressurized. The heat transfer of the wax pellet is slower than the vapour in the bellows type, and the reasons for this are given. Thermostat installations are discussed and illustrated.
Hydraulic Torque Converters in Tractors
Authors: Vasey G. H.
Published: June 2010

Using a sequence of graphs the characteristic features are developed of the performance of a tractor fitted with a hydraulic torque converter. In particular an attempt is made to relate the performance through the hydraulic unit to the performance of the internal-combustion engine that provides the input torque and speed.

The essential feature of coupling the input impeller to the engine is the consequence that the engine runs virtually at constant output, that is, constant torque, speed, and fuel consumption; and it does so virtually irrespective of changes in load on the output runner. The characteristic features of the runner or output member are an approximately linear and therefore ‘stepless’ torque/speed performance, and a highly variable efficiency and power output, approximately parabolic with output speed.

The output from this inherent stepless torque conversion is compared with the stepped conversions of the conventional gear transmissions. At maximum power throughput the efficiency of the hydraulic unit is about 85 per cent, compared with about 90 per cent plus, for the orthodox gear transmission.

The performances of both types of tractor on formal tests of the Nebraska† type are also compared. Methods of automatic control of the combined engine/converter, for example, to give a constant output speed, are suggested.
Torsional Vibration
Authors: Braund D. F.
Published: June 2010

The construction of an internal-combustion engine is such as to make it susceptible to resonant torsional oscillation of the crankshaft.

When an engine is operated near a critical speed, that is, a speed at which the pulsations produced by each cylinder excite the natural frequency of the crankshaft, excessive torsional amplitudes are developed which may seriously damage the engine. Unless measures are taken to introduce damping into the system the engine cannot be run continuously in critical speed zones. Restriction of running speeds is generally inconvenient and vibration dampers have to be applied to limit torsional vibration amplitudes and stresses to safe values.
First Paper: A View of the California Motor Vehicle Pollution Control Effort
Authors: Hass G. C.
Published: June 2010

The nature of the smog problem in California is discussed, with particular reference to the role of motor vehicle emissions. The history of efforts to control air pollution in California is reviewed, from local control programmes for stationary sources to the current state programme for motor vehicle emissions control. The legal framework, present programme, and the present stage of development of control devices are discussed in detail.
Automation in an Engine Laboratory
Authors: Larborn A.
Published: June 2010

An engine laboratory is described where rationalization and automation is developed to a high level. Function test beds are arranged mainly for accurate measurements and flexible conditions. Endurance test beds feature programmed cycling, automatic data recording and test supervision. All test beds include extensive arrangements for automatic handling of emergency situations with maximum safety for equipment and personnel. Endurance test beds simulate road conditions to a high degree and show considerable savings in test time and running cost compared to vehicle testing of engines. Statistics from equipment reliability are presented.
Principles of Soil-Vehicle Mechanics
Authors: Reece A. R.
Published: June 2010

The object of soil-vehicle mechanics is defined and existing theories briefly described. Experiments have shown that these theories work quite well for frictionless clay soils and for lightly loaded vehicles in firm soils where sinkage is small. For other soft soils performance cannot be predicted and the theory does not agree with experimental evidence.

It is proposed that an improved and unified theory can be based on equations developed using the methods of soil mechanics, making appropriate allowance for the effect of compressibility. A resulting new pressure sinkage equation is shown to give better agreement with experiment.

The complexities of the soil stress pattern imposed by vehicles are described and it is shown that these cannot be neglected. The effect of superimposing horizontal and vertical loads is to cause slip sinkage and experimental measurements show this to be important in sand but not in clay. An analysis is made which explains why this is so and gives insight into the physical nature of the phenomenon.

The aims of current research are described and illustrated with results from recent measurements of wheel performance.
First Paper: Unaided Starting of Diesel Engines
Authors: Biddulph T. W. , Lyn W-T.
Published: June 2010

The unaided starting behaviour of seven diesel engines of different sizes and designs has been studied in some detail. It has been established that the cranking time required to achieve an ignition (the first fire) depends on (a) the compression temperature available for a given ambient temperature and cranking speed, (6) the increase in compression temperature per cycle when the engine is cranked and fuelled and ( c) the temperature required for ignition which can be obtained from ignition delay data.

The time taken from first fire to starter-off depends on a number of factors, and these are discussed and the differences in this respect between the direct injection (D.I.) and the indirect injection (I.D.I.) engines pointed out.

Based on the above facts, the starting behaviours of the seven engines are shown to be predictable from the respective three sets of data described above and obtained experimentally.

In order to permit prediction at the engine design stage, the effects of engine geometry on heat and mass loss and hence on the compression temperature are examined in detail. The generalized data on heat and mass loss, the increase in compression temperature per cycle and the ignition delay are then presented, from which the unaided starting behaviour of any engine can be predicted.

While the accuracy obtainable is only within 5 degC in ambient temperature, such a prediction is considered to be useful when it is realized that the range of unaided starting temperature of practical engines is as much as 50 degC.

Finally, the relationships between engine size, startability and compression ratio are discussed, based on the theory developed.