bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of RNASEL Variants with Prostate Cancer Risk in Hispanic Caucasians and African Americans
Authors: Shook Stacie J. , Beuten Joke , Torkko Kathleen C. , Johnson-Pais Teresa L. , Troyer Dean A. , Thompson Ian M. , Leach Robin J.
Published: October 2007

Purpose: The RNASEL gene at 1q25 has been identified as a hereditary prostate cancer susceptibility gene, but to date, no study has investigated the role of RNASEL variants in Hispanic Caucasian men with prostate cancer.

Experimental Design: Two RNASEL common variants, located at amino acids 462 and 541, were genotyped in non-Hispanic Caucasian, Hispanic Caucasian, and African American prostate cancer cases and controls.

Results: The RNASEL 462 AA genotype was found to increase prostate cancer risk over 4-fold in Hispanic Caucasians [odds ratio (OR), 4.43; 95% confidence interval (95% CI), 1.68-11.68; P = 0.003] and over 10-fold in African Americans (OR, 10.41; 95% CI, 2.62-41.40; P = 0.001) when compared with the GG genotype. Analysis of the RNASEL 541 variant showed that Hispanic Caucasian patients with the GG genotype had a statistically significant increase in their risk for developing prostate cancer when compared with the TT and GT genotypes (OR, 1.91; 95% CI, 1.16-3.14; P = 0.01). A common G-T haplotype for the combination of the RNASEL 462 and 541 variants was found to occur more frequently in controls compared with cases in African Americans (P = 0.04) but not in non-Hispanic Caucasians or Hispanic Caucasians.

Conclusions: This is the first study that investigates the association of prostate cancer risk with RNASEL variants in Hispanic men. Our data support the role of RNASEL as a predisposition gene for prostate cancer and showed a significant association between the RNASEL 462 variant and prostate cancer risk in African Americans and Hispanic Caucasians.
Anthrax Lethal Toxin Inhibits Growth of and Vascular Endothelial Growth Factor Release from Endothelial Cells Expressing the Human Herpes Virus 8 Viral G Protein–Coupled Receptor
Authors: Depeille Philippe , Young John J. , Boguslawski Elissa A. , Berghuis Bree D. , Kort Eric J. , Resau James H. , Frankel Arthur E. , Duesbery Nicholas S.
Published: October 2007

Purpose: In this study, we tested the hypothesis that inhibition of mitogen-activated protein kinase kinases (MKK) inhibits tumor growth by acting on angiogenic signaling and by extension may form the basis of an effective strategy for treatment of Kaposi's sarcoma.

Experimental Design: Murine endothelial cells expressing the human herpes virus 8 G protein–coupled receptor (vGPCR-SVEC) were treated with anthrax lethal toxin (LeTx). LeTx is a binary toxin ordinarily secreted by Bacillus anthracis and is composed of two proteins: protective antigen (the binding moiety) and lethal factor (the active moiety). Lethal factor is a protease that cleaves and inactivates MKKs.

Results: In vitro, treatment of vGPCR-SVEC with LeTx inhibited MKK signaling, moderately inhibited cell proliferation, and blocked the ability of these cells to form colonies in soft agar. Treatment with LeTx also blocked the ability of these cells to release several angioproliferative cytokines, notably vascular endothelial growth factor (VEGF). In contrast, inhibition of mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 with U0126 caused a substantial inhibition of proliferation but only modestly inhibited VEGF release. In xenograft models, i.v. injection of LeTx caused reduced tumor growth characterized immunohistochemically by inhibition of MKK signaling, decreased rates of proliferation, and reduced levels of VEGF and VEGF receptor 2, with a corresponding decrease in vascular density.

Conclusions: These data support a role for MKK signaling in tumor growth and vascularization and are consistent with the hypothesis that inhibition of MKK signaling by LeTx or a similar agent may be an effective strategy for the treatment of Kaposi's sarcoma as well as other vascular tumors.
Measurement of Cyclin E Genomic Copy Number and Strand Length in Cell-Free DNA Distinguish Malignant versus Benign Effusions
Authors: Salani Ritu , Davidson Ben , Fiegl Michael , Marth Christian , Müller-Holzner Elisabeth , Gastl Guenther , Huang Han-Yao , Hsiao Jui-Chi , Lin Her-Sheng , Wang Tian-Li , Lin Bai-Ling , Shih Ie-Ming
Published: October 2007

Purpose: Previous studies have shown that the concentration of cell-free DNA was higher and its strand length longer in body fluids obtained from patients with cancer as compared to patients with benign diseases. We hypothesized that analysis of both DNA copy number and strand length of cell-free DNA from an amplified chromosomal region could improve the diagnosis of malignant diseases in body fluids.

Experimental Design: To test this hypothesis, we used ovarian cancer effusion as an example and applied a quantitative real-time PCR to measure the relative copy number and strand length of DNA fragments from one of the most frequently amplified genes, cyclin E, in ovarian serous carcinomas.

Results: As compared with nonamplified chromosomal loci, including β-actin, p53, 2p24.1, and 4p15.31, measurement of cyclin E DNA copy number (100 bp) had the best performance in distinguishing malignant (n = 88) from benign (n = 70) effusions after normalization to effusion volume or Line-1 DNA with areas under the receiver operating characteristics curve (AUC) of 0.832 and 0.847, respectively. Different DNA lengths of the cyclin E locus were further analyzed and we found that the AUC was highest by measuring the 400-bp cyclin E locus (AUC = 0.896). The AUC was improved to 0.936 when it was combined with the length integrity index as defined by the relative abundance of 400 bp cyclin E to 100 bp p53 loci. Cyclin E real-time PCR assay had a higher sensitivity (95.6%) than routine cytology examination (73.9%) and was able to diagnose false-negative cytology cases in this study.

Conclusions: The above findings indicate that measurement of the DNA copy number and strand length of the cyclin E locus is a useful cancer diagnostic tool.
Platelet-Derived Growth Factor Receptor Inhibition and Chemotherapy for Castration-Resistant Prostate Cancer with Bone Metastases
Authors: Mathew Paul , Thall Peter F. , Bucana Corazon D. , Oh William K. , Morris Michael J. , Jones Donnah M. , Johnson Marcella M. , Wen Sijin , Pagliaro Lance C. , Tannir Nizar M. , Tu Shi-Ming , Meluch Anthony A. , Smith Lon , Cohen Lorenzo , Kim Sun-Jin , Troncoso Patricia , Fidler Isaiah J. , Logothetis Christopher J.
Published: October 2007

Purpose: To further assess preclinical and early clinical evidence that imatinib mesylate, a platelet-derived growth factor receptor (PDGFR) inhibitor, modulates taxane activity in prostate cancer and bone metastases, a randomized study was conducted.

Experimental Design: Men with progressive castration-resistant prostate cancer with bone metastases (n = 144) were planned for equal randomization to i.v. 30 mg/m2 docetaxel on days 1, 8, 15, and 22 every 42 days with 600 mg imatinib daily or placebo, for an improvement in median progression-free survival from 4.5 to 7.5 months (two-sided α = 0.05 and β = 0.20). Secondary end points included differential toxicity and bone turnover markers, tumor phosphorylated PDGFR (p-PDGFR) expression, and modulation of p-PDGFR in peripheral blood leukocytes.

Results: Accrual was halted early because of adverse gastrointestinal events. Among 116 evaluable men (57 docetaxel + imatinib; 59 docetaxel + placebo), respective median times to progression were 4.2 months (95% confidence interval, 3.1-7.5) and 4.2 months (95% confidence interval, 3.0-6.8; P = 0.58, log-rank test). Excess grade 3 toxicities (n = 23) in the docetaxel + imatinib group were principally fatigue and gastrointestinal. Tumor p-PDGFR expression was observed in 12 of 14 (86%) evaluable bone specimens. In peripheral blood leukocytes, p-PDGFR reduction was more likely in docetaxel + imatinib–treated patients compared with docetaxel + placebo (P < 0.0001), as were reductions in urine N-telopeptides (P = 0.004) but not serum bone-specific alkaline phosphatase (P = 0.099).

Conclusions: These clinical and translational results question the value of PDGFR inhibition with taxane chemotherapy in prostate cancer bone metastases and are at variance with the preclinical studies. This discordance requires explanation.
Toward a Methodology of Understanding the Nature and Scope of the Concept of Sunnah
Authors: Duderija Adis
Published: October 2007

This article outlines several features of a new methodology of the

nature

and

scope

of the concept of Sunnah. The proposed methodology would permit us to better understand the

nature

and

scope

of the Sunnah and its inter-relationship with the body of Quranic and

Hadīth

texts. It will do so by outlining some salient features of a new methodology that will allow for the conceptual differentiation between Sunnah and

Hadīth

beyond those proposed so far. The article will argue that the way the

nature

and

scope

of the concept of Sunnah is understood or defined is inextricably linked with the way the

nature

,

objectives

, and

character

of Quranic Revelation is conceptualized. Additionally, the paper will argue on the basis of several examples that apart from its

amal

or practice based component, the Sunnah comprises of

akhlāq

,

fiqh

,

aqīdah

, and

ibādah

elements which are epistemologically and methodologically independent of

Hadīth

but organically linked to a particular type of Quranic hermeneutic. The article concludes with a brief discussion on the status of

Hadīth

literature in relation to the Quranic and Sunnah bodies of knowledge.
Antecedents of Impression Management Use and Effectiveness in a Structured Interview†
Authors: Van Iddekinge Chad H. , McFarland Lynn A. , Raymark Patrick H.
Published: October 2007

The authors examine personality variables and interview format as potential antecedents of impression management (IM) behaviors in simulated selection interviews. The means by which these variables affect ratings of interview performance is also investigated. The altruism facet of agreeableness predicted defensive IM behaviors, the vulnerability facet of emotional stability predicted self- and other-focused behaviors, and interview format (behavior description vs. situational questions) predicted self-focused and defensive behaviors. Consistent with theory and research on situational strength, antecedent—IM relations were consistently weaker in a strong situation in which interviewees had an incentive to manage their impressions. There was also evidence that IM partially mediated the effects of personality and interview format on interview performance in the weak situation.
Influence of Founder—CEOs' Personal Values on Firm Performance: Moderating Effects of Firm Age and Size†
Authors: Yan Ling  , Hao Zhao  , Baron Robert A.
Published: October 2007

The effects of two values held by founder—CEOs (collectivism and novelty) on companies' post—start-up performance are investigated. By integrating congruence and organizational lifecycle literatures, the authors hypothesized that the effects of both values are moderated by company age and size, such that collectivism exerts stronger beneficial effects in older and larger firms, whereas novelty exerts stronger beneficial effects in younger and smaller firms. Results based on 92 small- to medium-sized enterprises offer support for most predictions, thus demonstrating the influence of founders' values on new venture performance and highlighting the importance of considering organizational lifecycle for the understanding of this influence.
Tissue Factor: A Critical Role in Inflammation and Cancer
Authors: Lwaleed Bashir A. , Cooper Alan J. , Voegeli David , Getliffe Kathryn
Published: October 2007

A series of coordinated enzymatic reactions takes place in the body whenever blood clots. The major physiological initiator of these reactions is a membrane-bound glycoprotein known as tissue factor (TF), which is normally separated from the bloodstream by the vascular endothelium. Bleeding, caused by injury or tissue damage, activates a complex enzyme cascade as TF becomes exposed to the bloodstream. In disease states, leukocytes or the vascular endothelium may abnormally express TF to cause intravascular coagulation. The blood-coagulation cascade is also relevant to diseases such as hemophilia, in which patients are deficient in blood proteins necessary for clotting, and is linked to vascular diseases such as heart attack and stroke, in which clotting can lead to the occlusion of blood vessels. Coagulation is also activated in inflammation and cancer. In this article, we discuss characteristics of TF and review its role in inflammation and cancer.
C-reactive Protein in Nipple Aspirate Fluid Associated With Gail Model Factors
Authors: Lithgow Diana , Nyamathi Adeline , Elashoff David , Martinez-Maza Otoniel , Covington Chandice
Published: October 2007

Background: The majority of breast cancers originate in the epithelial lining of the breast ductal system. Premalignant cell damage in this lining may produce biochemical signals that deliver inflammatory proteins to the site. The presence of C-reactive protein (CRP) in nipple aspirate fluid (NAF) may reflect an inflammatory state indicative of a premalignant breast microenvironment. This study ascertained CRP's presence in NAF and evaluated if risk factors, as identified by the Gail model, were associated with NAF CRP levels among healthy women. Design: NAF CRP levels were assayed in 59 women. Results: CRP was present in NAF and significantly ( p = .04) and positively related to breast cancer risk as predicted by the Gail model. Conclusion: CRP is differentially present in NAF and varies by Gail model risk factors. CRP in NAF holds promise as a noninvasive biomarker that detects a precarcinogenic breast ductal microenvironment and may contribute to the diagnosis of breast cancer early in the course of the disease when prognosis is most favorable.
Relationship of SERT Polymorphisms to Depressive and Anxiety Symptoms in Irritable Bowel Syndrome
Authors: Jarrett Monica E. , Kohen Ruth , Cain Kevin C. , Burr Robert L. , Poppe Ann , Navaja Grace P. , Heitkemper Margaret M.
Published: October 2007

This study investigates the association of psychological symptoms with the distribution of two serotonin transporter gene (SERT) polymorphisms, located in the promoter region (5-HTTLPR) and in intron 2 (STin2 VNTR), in patients with irritable bowel syndrome (IBS). Participants, 21 men and 117 women, were assessed for mental health history and current psychological distress. A blood sample was used for genotyping. Participants who were homozygous for the short allele of 5-HTTLPR or carried a STin2.9 VNTR allele were significantly more likely to have a history of depression. Participants did not differ by genotype in their history of anxiety or suicidal ideation nor in their current levels of depression, anxiety, or general psychological distress. The results support a biopsychosocial model of IBS in which SERT genotype modifies the risk for depressive episodes. Long term, practitioners may individualize treatment of patients with IBS using genotype as one of the factors.
Direct Sequencing Is More Accurate and Feasible in Detecting Single Nucleotide Polymorphisms than RFLP: Using Human Vascular Endothelial Growth Factor Gene as a Model
Authors: Davis Amy H. T. , Jianhua Wang  , Tsang Tom C. , Harris David T.
Published: October 2007

Since the sequencing of the human genome, there has been increased interest in understanding the distribution and effects of genetic variations among individuals. Restriction fragment length polymorphism (RFLP) is a well-established and frequently used method for genotyping. This method, however, is indirect and has a number of limitations. It is thus important to reevaluate the use of RFLP in light of more contemporary methods of genotyping. The specific aims of this study are to (a) compare genotyping methods of traditional RFLP with contemporary direct sequencing for accurate identification of polymorphisms within the human vascular endothelial growth factor (VEGF) gene and (b) describe distribution of a known single nucleotide polymorphism (SNP) in the VEGF gene in a sample composed of 50 healthy volunteers. Polymerase chain reaction (PCR) was used to amplify the initial sample of DNA. Genotypes of a G-to-A substitution (GG, AG, AA) at -1154 were analyzed by RFLP and direct sequencing. RFLP was unable to discriminate among the three possible genotypes, whereas direct sequencing clearly identified genotype for all 50 samples. Observed genotype frequencies were comparable with the Hardy-Weinberg principle. This comparative study provides justification for selecting direct sequencing instead of RFLP for detecting SNPs in selected genes.
Efficacy of St. John's Wort for Treating Mild to Moderate Depression
Authors: Gahlsdorf Tera , Krause Robert , Beal Margaret W.
Published: October 2007

Current studies regarding the efficacy of the herb St. John's wort (SJW) in treating mild to moderate cases of depression show conflicting evidence. In this article, we review the literature and consider similarities and differences between studies showing some efficacy and those showing none. Twelve published reports were reviewed. The majority of studies indicated the efficacy of SJW in the treatment of mild to moderate cases of depression. Most trials have had small sample sizes and either a placebo group or a standard pharmaceutical group. Two studies (both pediatric) were uncontrolled. Studies generally reported outcomes that had positive implications for their financial supporters and/or those with whom the primary investigators had acknowledged financial affiliations. More studies that have larger sample sizes and include placebo and pharmaceutical control groups are needed.
Painful ANA-Positive Scleroderma-Like Disease With Acral Ulcerations: A Case of Chronic Gangrenous Ergotism
Authors: Wollina Uwe , Hansel Gesine , Gruner Monika , Schönlebe Jaqueline , Heinig Birgit , Köstler Erich
Published: October 2007

Chronic ergotism is a rare cause of limb ischemia. In this case report, the authors present a 62-year-old woman with history of long-term use of ergotamine alkaloids for the treatment of menstrual pain, who developed a severe painful disease initially misdiagnosed as systemic sclerosis (scleroderma) for 3 decades. She presented with a combination of acral gangrene, foot ulcer, renal obstruction, mild pulmonary fibrosis, and reduced esophageal motility. Right-sided renal obstruction was evident. The condition was extremely painful and had led to muscular contractions and immobility, drug abuse, and anemia. After establishing the diagnosis of chronic gangrenous ergotism, changing drug therapy, mobilization, and treatment of chronic wounds, she showed a remarkable recovery. Eventually the foot ulcer was closed successfully using a mesh graft transplantation, and the patient was able to walk alone. Chronic ergotism is rare but has to be taken into account when presented with painful chronic digital and foot ulcers.
Macrophages contribute to the antitumor activity of the anti-CD30 antibody SGN-30
Authors: Oflazoglu Ezogelin , Stone Ivan J. , Gordon Kristine A. , Grewal Iqbal S. , van Rooijen Nico , Law Che-Leung , Gerber Hans-Peter
Published: October 2007

Increased expression of CD30 is associated with a variety of hematologic malignancies, including Hodgkin disease (HD) and anaplastic large cell lymphoma (ALCL). The anti-CD30 monoclonal antibody SGN-30 induces direct antitumor activity by promoting growth arrest and DNA fragmentation of CD30+ tumor cells. In this study, we investigated the contributions of Fc-mediated effector cell functions to SGN-30 activity. We determined that antibody-dependent cellular phagocytosis, mediated by macrophages, to contribute significantly to antitumor activity in vitro. To delineate the identity of the host effector cells involved in mediating antitumor activity in vivo, we studied the effects of effector cell ablation in a disseminated model of HD (L540cy). Depletion of macrophages markedly reduced efficacy of SGN-30, demonstrating that macrophages contribute significantly to SGN-30 efficacy in this model. These findings may have implications for patient stratification or combination treatment strategies in clinical trials conducted with SGN-30 in HD and ALCL.
Ethnic variations in the experiences of mental health service users in England
Authors: Raleigh Veena S. , Irons Robert , Hawe Emma , Scobie Sarah , Cook Adrian , Reeves Rachel , Petruckevitch Ann , Harrison Juliette
Published: October 2007

Background

Minority ethnic groups in the UK are reported to have a poor experience of mental health services, but comparative information is scarce.

Aims

To examine ethnic differences in patients' experience of community mental health services.

Method

Trusts providing mental health services in England conducted surveys in 2004 and 2005 of users of community mental health services. Multiple regression was used to examine ethnic differences in responses.

Results

About 27 000 patients responded to each of the surveys, of whom 10% were of minority ethnic origin. In the 2004 survey, age, living alone, detention and hospital admissions were stronger predictors of patient experience than ethnicity Self-reported mental health status had the strongest explanatory effect. In the 2005 survey, the main negative differences relative to the White British were for Asians.

Conclusions

Ethnicity had a smaller effect on patient experience than other variables. Relative to the White British, the Black group did not report negative experiences whereas the Asian group were most likely to respond negatively. However, there is a need for improvements in services for minority ethnic groups, including access to talking therapies and better recording of ethnicity.
Interventions for reducing the use of seclusion in psychiatric facilities
Authors: Gaskin Cadeyrn J. , Elsom Stephen J. , Happell Brenda
Published: October 2007

Background

The authors of a recent systematic review concluded that the use of non-pharmacological containment methods, excluding restraint and seclusion, was not supported by evidence. Their focus on randomised, controlled trials, however, does not reflect the research that has been, or could be, conducted.

Aims

To find empirically supported interventions that allow reduction in the use of seclusion in psychiatric facilities.

Method

We reviewed English-language, peer-reviewed literature on interventions that allow reduction in the use of seclusion.

Results

Staff typically used multiple interventions, including state-level support, state policy and regulation changes, leadership, examinations of the practice contexts, staff integration, treatment plan improvement, increased staff to patient ratios, monitoring seclusion episodes, psychiatric emergency response teams, staff education, monitoring of patients, pharmacological interventions, treating patients as active participants in seclusion reduction interventions, changing the therapeutic environment, changing the facility environment, adopting a facility focus, and improving staff safety and welfare.

Conclusions

Reducing seclusion rates is challenging and generally requires staff to implement several interventions.
‘Uppers’ keep going up
Authors: Ghodse Hamid
Published: October 2007

Amphetamine-type stimulants are the second most widely used drugs in the world. Over prescription results in diversion for recreational use and the development of dependence. The internet plays a significant role in global misuse of amphetamine-type stimulants, permitting uncontrolled dispensing by online pharmacies and providing information on techniques for illicit manufacture.
Research into putative biological mechanisms of mental disorders has been of no value to clinical psychiatry
Authors: Kingdon David , Young Allan H.
Published: October 2007

In 1845 Griesinger declared that mental disorders were physical in origin (Kendell, 2001). The discovery of the bacterial cause of general paresis and the anatomical basis for Alzheimer's disease seemed to confirm this belief. However, is it still reasonable, a century later, to continue to devote increasing amounts of financial and expert human resource to pursuing further possible physical causes for mental disorders? The belief that there remain undiscovered and important biological causes for mental disorders continues to exert a major influence on the direction of research, practice and public education. But has it helped us to understand aetiology, improve management or destigmatise mental disorders?
Recurrence of major depression in adolescence and early adulthood, and later mental health, educational and economic outcomes
Authors: Fergusson David M. , Boden Joseph M. , Horwood L. John
Published: October 2007

Background

It is unclear how the recurrence of major depression in adolescence affects later life outcomes.

Aims

To examine the associations between the frequency of major depression at ages 16–21 and later outcomes, both before and after controlling for potentially confounding factors.

Method

Data were gathered from a 25-year longitudinal study of a birth cohort of New Zealand children (n=982). Outcome measures included DSM–IV symptom criteria for major depression and anxiety disorders, suicidal ideation and attempted suicide, achieving university degree or other tertiary education qualification, welfare dependence and unemployment, and income at ages 21–25 years.

Results

There were significant (P<0.05) associations between the frequency of depression at ages 16–21 years and all outcome measures. After adjustment for confounding factors, the association between frequency of depression and all mental health outcomes, and welfare dependence and unemployment, remained significant (P<0.05).

Conclusions

The frequency of depression in adolescence and young adulthood is associated with adverse mental health and economic outcomes in early adulthood.
The Compression-Ignition Engine and Its Applicability to British Railway Traction
Authors: Fell L. F. R.
Published: October 2007

The author considers that, while the internal combustion engine is not universally applicable to British railway traction, there is a wide field which can be more economically covered by the oil engine than by other means. Electric transmission is, in spite of high first cost, the most readily adaptable for use in conjunction with the oil engine, and possesses a balance of advantages over all other known systems.

The oil-electric locomotive offers a long list of important advantages for railway operation not possessed by other systems. These advantages are, however, offset by high first cost for powers of 1,000 b.h.p. and over. A comparison is drawn between the first cost of steam and oil-electric locomotives for the various duties called for in the service of a British railway. This shows that, while the first cost of the oil-electric main line express passenger locomotive is three times that of the existing steam locomotive, the first costs of branch passenger, medium goods, and shunting steam and oil-electric engines are comparable. This is owing to the cost per brake horse-power required diminishing with increase of size in the case of the steam locomotive, whereas it remains constant in the case of the oil-electric. Owing to the high rate of acceleration necessary the use of the oil-electric system is considered unsuitable as a substitute for dependent electrification of suburban lines.

The railway oil engine is a specialized requirement. It must be of the high-speed type running at speeds of up to 1,500 r.p.m., in order to reduce first cost and for other reasons. Details are given of various types of British compression-ignition engines which are considered suitable for British railway work. The author deduces that an engine of twelve-cylinder “V” type and an engine with six cylinders in line, both incorporating the same design and size of cylinder, would fill all the requirements which can be economically met by the oil engine on a British railway. He selects the single sleeve-valve engine design as having the greatest balance of advantages in its favour for railway purposes. Attention is drawn to the importance of simplifying the installation of the compression-ignition engine and various suggestions are put forward to this end.

In conclusion the author stresses the importance of the railway companies giving a lead to the internal combustion engine industry as to the railway requirements in size and type of engine, and states that it is the purpose of his paper to assist those concerned in arriving at this immediately important decision.
The Handling and Storing of Grain, with Special Reference to Canadian Methods
Authors: Broughton H. H.
Published: October 2007

Few people have either the time or inclination to investigate the means by which the raw material of which their bread is made comes from remote places at the rate of half a million tons a month; but it behoves one to remember that had the machinery to cease functioning from any cause for a time reckoned in weeks, famine would inevitably result. Although by far the largest importer of wheat, Britain has safe storage facilities for a relatively small tonnage. Adequate storage facilities, which can be provided at no great cost, are as necessary near the centres of consumption as they are near the centres of production.

Hitherto papers on the subject read before the engineering Institutions have been restricted to a consideration of the machinery and methods employed in the unloading of parcel cargoes at British ports. The author deals with the equally important methods practised in, and the machinery used by, one of the principal grain-exporting countries. The movement is traced step by step from the farm, through the country elevator, past the inspection point and on to the terminal elevator, thence through the transfer elevator and on to the ocean port for shipment. Canadian methods are described because Canada excels in the art of grain handling, and it is the ambition of other countries to follow her example.

The grain-handling problem in Canada is that of collecting several hundred million bushels of uncleaned wheat in small quantities from 250,000 or more farms scattered over a very large area, and of rapidly delivering at minimum cost, inspected, graded, cleaned, and conditioned wheat at the shipping point, 1,700 miles distant from the centre of production when the Great Lakes-St. Lawrence route is not icebound, and a substantially greater mileage when this waterway is closed. The trade is regulated by the Dominion Government under the Canada Grain Act, and grain on the move is inspected and graded by Government officials. Weighing is likewise supervised. Elevators are operated under licence, and as the grain is being spouted into the holds of oceangoing vessels it is again sampled for certifying of the grade.

After brief reference to the method of handling and to certain sections of the Grain Act, the author describes the functions of country, terminal, and transfer elevators. Typical plants of each kind are illustrated, and special consideration is given to a number of the problems connected with the design, construction, and operation of terminal and port elevators. The receiving, distributing, storage, and shipping sections of the elevator are described in detail; the influence of these on design is discussed, and several of the mechanical and electrical problems are noted. Without exception modern elevators are of reinforced concrete and the “moving forms” used in their construction are described. Itemized costs of elevator buildings are given in an Appendix.
The Production of a Vacuum in an Air Tank by Means of a Steam Jet
Authors: Watson F. R. B.
Published: October 2007

The paper consists mainly of an account of experiments conducted by the author on a steam-jet operated air ejector with the object of investigating certain quantities which, although they affect the vacuum produced, are not included in the theory of the ejector as it exists at present. The chief of these quantities was found to be the distance from the outlet of the steam nozzle to the throat entrance of the diffuser, and in order to examine the effect of varying this length a special form of air ejector with a sliding diffuser was designed and provision was made in the design for the use of a search tube which could be passed right through the diffuser and up to the nozzle outlet. In addition to the work conducted on this apparatus the author was obliged to carry out a separate set of experiments, with the diffuser removed, and in which an air pump created the vacuum, in order to examine the change in the stationary waves in the steam jet when it was discharging at different vacua. This was done by viewing the jet through a plate-glass window fitted into a part of the ejector. Observations were made and photographic records were obtained at different outlet pressures ranging from atmospheric pressure to 27·5 inches of vacuum. These photographs are probably of interest in connexion with steam nozzles in general, as they show the form of the jet when it was over-expanded and under-expanded as well as when it expanded to the designed pressure. The ejector was also operated normally with a glass mouthpiece forming the entrance and parallel throat of the diffuser, and this arrangement was used to view the waves in the throat at the higher vacua.

Another quantity which affects the vacuum is the length of the diffuser throat and two throat lengths were used: ( a) inch, and ( b) a length equal to twice the throat diameter, or 1½ inches. Two different forms of diffuser entrance were tried, and the vacuum and steam-air ratio at different initial steam pressures for these two different designs have been recorded in the paper.
The Investigation of the Mechanical Break-Down of Prime Movers and Boiler Plant
Authors: Schuster L. W.
Published: October 2007

In 1896 a Past-President of the Institution, the late Michael Longridge, read before the Institution a classical paper entitled, “Breakdowns of Stationary Steam-Engines.” This dealt fully with the design and the causes of failure of steam engines in factories. In the thirty-seven years that have intervened progress has naturally been made in methods of carrying out investigations of failure, and the present paper, though it makes no claim to emulate its forerunner, may be looked upon as a sequel to it.

In the course of preparation the author discovered that he had entered into a field so vast that a series of papers would be required to deal effectively with the subject. A general review of failures of the type in question would not allow space to treat any effectively; for this reason, though a few examples are taken from public power station plant, the subject matter has been confined mainly to the more important parts of prime movers in factories, and as the paper refers more especially to steam plant than to internal combustion engines, the ground of the previous paper has been extended to cover failure of steam boilers.

By the term “mechanical” failure the intention is to exclude failures primarily caused by corrosion. Equally, though the term is undoubtedly arbitrary, the intention is to exclude failures due to casting and other forms of internal stress or to thermal stresses. The entrance of water into the cylinders of steam engines and turbines is also excluded.
Cutting Tools Research Committee: Report on the Ageing of Tool Steel
Authors: Herbert E. G.
Published: October 2007

Attention is drawn to changes which take place in freshly hardened tool steel, enabling tools to be straightened by bending immediately after hardening. A detailed study was made of hardness changes occurring during several hours after the “secondary heat treatment” of high-speed steel, the treatment being applied repeatedly to the same specimen. The ensuing fluctuations appeared to be periodic and characterized by increasing time periodicity, and they were found to be susceptible to magnetism. Similar, but much more rapid, fluctuations were found to occur in the hot steel during heat treatment.

Periodic fluctuations having been observed during the ageing of metals after severe disturbance by thermal, mechanical, or magnetic treatment, an investigation of these phenomena was made in very pure metals, nickel, iron, and gold, and certain general conclusions were reached, the fluctuations being attributed to periodic changes in the state of cohesion, probably electromagnetic in character.

Experiments were resumed on high-speed steel, their object being to find the combination of thermal and magnetic treatment which would set up fluctuations of greatest amplitude capable of being stabilized magnetically at a maximum or minimum phase so as to produce the greatest permanent change in the physical characteristics of the steel.

Drilling tests were carried out with twist drills subjected to various treatments suggested by the foregoing experiments, and it was found possible to increase the life of a drill many times by a suitable combination of magnetic and thermal treatments. Confirmatory evidence is quoted of hardness variations caused by magnetic treatment in the experiments of other workers. The influence of the mechanism of the various hardness tests is discussed.
Fatigue and Corrosion Fatigue with Special Reference to Service Breakages
Authors: Bacon Frederic
Published: October 2007

There is need for closer co-operation between those who encounter service breakages and those engaged in research on the strength of materials, because various causes are conspiring to enhance liability to fatigue failure in modern prime movers and machines. In the author's investigations, special attention has been paid to the crack spreading process with the twofold object (1) of interpreting the features found on fatigue fractures, and (2) as a method of attacking the problem of crack formation from a new angle.

The fatigue testing machines and material used are briefly described. Crack spread in plain specimens has been found to follow definite laws of a very simple character. There is a fixed relationship between the markings on a fracture produced in rotary bending and the direction of rotation, which the author calls “crack slip.” Matters become more complex when “stress raisers” are present, as also when cracks converge from several separate origins.

The stresses in revolving beams of square section, and of round section with equal parallel flats, are discussed at some length, and theory and experiment are shown to be in complete agreement. Reference is made to the fatigue fracture of the main haulage shaft at a colliery and to a danger which must be reckoned with in the blading of steam turbines. Attention is drawn to the weakening effect of the local concentrations of stress produced by holes, shoulders, keyways, etc., and two examples are included of an attempt to locate and assess the diminution of fatigue resistance at the weakest spot of a projected design by a single fatigue test of a suitable model.

The history of corrosion fatigue is briefly reviewed, with comments as to why its discovery is of such recent origin. An extensive list of practical instances where corrosion fatigue is the known or suspected cause of failure is given. Examples of the pitting and cracking processes peculiar to corrosion fatigue are illustrated and discussed, the corrosive agent being a small steam jet in air, and attention is drawn to the differences which are found according as the limits of cyclic stress are near, or much below, the fatigue limit in air.
The Aluminium Industry in Scotland
Authors: Boex George
Published: October 2007

The production of aluminium is divided into five sections: mining, alumina manufacture, carbon electrode works, aluminium reduction works, and rolling mills; and the reasons determining the location of factories are set forth. The aluminium industry in Scotland includes the manufacture of alumina and carbon electrodes, and the electrolytic production of the metal. The latter is absolutely dependent on cheap regular supplies of electrical power, as approximately 26,000 kilowatt-hours are required for the manufacture of one ton of aluminium from alumina.

The Burntisland Alumina Works of the British Aluminium Company are described. The process is a chemical one: the ore is ground and mixed in caustic soda liquor and digested under pressure and heat. Separation of solid impurities takes place, leaving a sodium aluminate liquor from which alumina hydrate settles out and is subsequently calcined. The plant includes grinding machines, digesters, decomposition tanks, rotary calciners, and accessory plant such as pumps and conveyers. A large supply of steam is necessary for the process.

The Carbon Works at Kinlochleven supply the electrodes necessary for three factories in the north of Scotland, and a description is given of the various raw materials used and their conversion into baked electrodes by grinding, mixing whilst hot with a binder of tar and pitch, pressing under 2,000 tons pressure, and baking in producer-gas-fired furnaces.

The electrolytic furnaces used to produce aluminium from alumina are similar in principle at the Foyers, Kinlochleven, and Lochaber factories, and as the latter is the latest factory erected in the north, a short description of the power system is given. Ultimately the power house will contain some 120,000 h.p. of generating plant. At present 33,000 kW. are installed. Each of the furnaces takes 40,000 amperes and is built of steel plate with a carbon lining forming a bath and serving as a cathode. The molten aluminium is deposited as a layer under the electrolyte, which is cryolite, and the carbon anode electrodes are consumed as the alumina is decomposed.

The cost of the complete development at Lochaber will be in the neighbourhood of £4,500,000.
Factors Affecting the Grip in Force, Shrink, and Expansion Fits
Authors: Russell Robert
Published: October 2007

Factors affecting the grip, which depends wholly on the elastic properties of the mating materials, are presented in the first part of the paper by a consideration of force fit practice in the assembly of wheel centres on axles. The degree of accuracy obtained in machining operations is determined by an examination of the out-of-roundness and the out-of-straightness of the cylindrical mating surfaces. The importance of considering the physical properties of the materials used in elastic grip assemblies is indicated by results obtained from specimens taken from wheel centres. Curves showing the residual force fit of elements which failed to satisfy back pressure tests suggest that failure was due to excessive fit allowances.

The effect of a reduction in the surface contact area is demonstrated by a series of tests on small steel elements. The nature of the lubricant is shown to have a great effect on the force necessary to produce axial slip in a force fit assembly. The lubricants considered include rape, sperm, Bayonne and “Texaco” motor oils, a mixture of graphite and engine bearing oil, and a cutting lubricant used in metal removal operations. The influence of “skin” or film on the mating surfaces before applying the lubricant is examined in a series of tests in which the mating elements are assembled with surfaces made clean by the use of solvents and by rubbing with a clean cloth. The quality of the grip established by mating the elements, by heating the hollow element, by cooling the solid element, and by pressing the hollow element over the solid element, is considered. Experimental results show that the grip is dependent on a surface film condition which may separate the elements on assembly and may be independent of the method of assembly. The condition of the mating surfaces after the fit is broken is examined and illustrated in each case.

Torsional resistance to slip is considered in the latter part of the paper. Force and shrink fit assemblies in which the elements are mated with surfaces lubricated, and with surfaces perfectly dry and free from film, are examined. An analysis of the results of tests provides further evidence of the great influence of a surface film condition on the resistance to slip and affords a means of comparing the axial and torsional coefficients of friction.
Sugar Factories and Sugar Machinery
Authors: Kilpatrick William
Published: October 2007

Figures for the total annual production of sugar show that it forms one of the great crops of the world, and the machinery used, both in handling the canes and in the factory, is of considerable importance. The author describes the method of sugar production, beginning with the supply of cane from the field to the factory, and then describing the simple defecation, sulphitation and carbonatation processes.

An account is given of the actual machinery used in sugar factories, and the design of crushing mills is considered. In all modern mills the top roll is fitted with a hydraulic pressure regulator. Until recently the majority of hydraulic attachments which came under the author's observation were badly designed or totally unsuited for their purpose. This was largely due to failure to realize the large amount of friction which can occur in the accumulator rams, in the rams in the cap, and in the bearing which slides in the gap in the mill cheek. The methods adopted to overcome this in the best modern practice are described. The methods of driving, by steam engines or electric motors, are discussed, and mention is made of the types of motors in general use. The variable factors are such that it is not possible to lay down any general rule as to the power necessary, but from a large number of examples in operation it has been found that the power required varies from 10·5 to 12 h.p. per ton of cane ground per hour. To cover faulty operation of the plant a fair margin of power is usually allowed in the prime mover. Diagrams are given showing the variation in the power required at different points in the mill and at different times in the working day. The author then deals with the chief points in the design of evaporators, vacuum pans, and crystallizers.

There is little waste in a sugar factory, and the refuse products or “bagasse” are used as fuel in the boilers. Some practical points in connexion with the use of this form of fuel are given, and the author concludes with some remarks on the layout of sugar factories. In an Appendix an analysis of the costs of crop, manufacturing expenses, and maintenance is given.
Some Technical Aspects of High-Pressure Boiler Design
Authors: Davis R. F. , Timmins A. L.
Published: October 2007

In introducing the subject the authors suggest a classification of boilers on a pressure basis. Alternative methods of drum construction are reviewed, leading to an investigation of the effects of higher saturated steam temperatures on the physical characteristics of the metal and the factor of safety. Attention is paid to the analysis of stresses induced in the drums of large high-pressure installations, with comments on the limitations of standard design rules and formulae. Similar treatment of the subject of boiler tubes follows, attention being directed particularly to the combined effects of temperature and stress.

The importance of accurate estimation of furnace exit temperature, especially in relation to superheat, and the effects of modern designs of water-cooled furnaces are then discussed. The influence of radiant heat emission from non-luminous gases in the convection passes is emphasized. A simple graphical method for determining the rate of natural circulation is outlined and the retarding influence of high pressure is discussed.

Orthodox designs of high-pressure boilers, the relative merits of which are compared, present no serious difficulty in operation, providing adequate attention is paid to feed water treatment, some aspects of which are discussed. Further developments are contingent upon the economic extension of the range of commercial heat-resisting metals; the adoption of more logical and adequate rules and regulations governing design; and closer investigation into the behaviour of tubes, etc., under high pressures and temperatures and subject to the conditions prevailing in a boiler when in service.