bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacotherapy for Erectile Dysfunction
Authors: Eardley Ian , Donatucci Craig , Corbin Jackie , El-Meliegy Amr , Hatzimouratidis Konstantinos , McVary Kevin , Munarriz Ricardo , Lee Sung Won
Published: January 2010

Introduction

Pharmacotherapy is the usual initial therapy for most men with erectile dysfunction.

Aim

To review the current data relating to the efficacy, tolerability and safety of drugs used in the treatment of men with erectile dysfunction.

Methods

A critical review of the literature relating to the use of pharmacotherapeutic agents was undertaken by a committee of eight experts from five countries, building on prior reviews.

Main Outcome Measures

Expert opinion and recommendations were based on grading of evidence-based literature, internal committee dialogue, open presentation, and debate.

Results

Almost all currently available evidence relates to sildenafil, tadalafil, and vardenafil. Phosphodiesterase type 5 (PDE5) inhibitors are first-line therapy for most men with erectile dysfunction who do not have a specific contraindication to their use. There is no evidence of significant differences in efficacy, safety, and tolerability between the PDE5 inhibitors and apomorphine. Intracavernosal injection therapy with alprostadil should be offered to patients as second line therapy for erectile dysfunction. Intraurethral alprostadil is a less effective treatment than intracavernosal alprostadil for the treatment of men with erectile dysfunction.

Conclusions

PDE5 inhibitors are effective, safe, and well-tolerated therapies for the treatment of men with erectile dysfunction. Apomorphine, intracavernosal injection therapy with alprostadil, and intraurethral alprostadil are all effective and well-tolerated treatments for men with erectile dysfunction. We recommend some standardization of the assessment of psychosocial outcomes within clinical trials in the field of erectile dysfunction.
REVIEW: Utilization of Pharmacotherapy for Erectile Dysfunction Following Treatment for Prostate Cancer
Authors: Prasad Michaella M. , Prasad Sandip M. , Hevelone Nathanael D. , Gu Xiangmei , Weinberg Aaron C. , Lipsitz Stuart R. , Palapattu Ganesh S. , Hu Jim C.
Published: January 2010

Introduction

Pharmacotherapies improve sexual function following treatments for localized prostate cancer; however, patterns of care remain unknown.

Aim

To ascertain post-treatment utilization of pharmacotherapies for erectile dysfunction (ED) using a population-based approach.

Methods

We identified 38,958 men who underwent definitive treatment for localized prostate cancer during 2003–2006 from the MarketScan Medstat data.

Main Outcome Measures

We compared the use of ED pharmacotherapy at baseline (up to 3 months prior) and up to 30 months following radical prostatectomy (RP) or radiotherapy (RT) for localized prostate cancer by utilizing National Drug Classification codes for phosphodiesterase-5 inhibitors (PDE5I), intracavernosal injectable therapies (IT), urethral suppositories and vacuum erection devices (VED). In adjusted analyses, we controlled for the effect of age, comorbidity, type of treatment, health plan and use of adjuvant hormone therapy on the use of pharmacotherapies.

Results

Men undergoing RP vs. RT were younger with less co-morbid conditions. Utilization of PDE5I was up to three times greater for men undergoing RP vs. RT, 25.6% vs. 8.8%, (P <0.0001) in the first post-treatment year, and usage of these agents was greatest for men undergoing minimally-invasive RP procedures. A higher percentage of men also used IT, suppositories and VED after RP vs. RT (P <0.001). However, more men in the RT group received adjuvant hormonal therapy (39.53% vs. 5.25% for RP, P <0.01). In adjusted analyses, men undergoing RP vs. RT were more than two times likely (OR 2.1, 95% CI 1.98, 2.26) to use PDE5I post-treatment while men on adjuvant hormonal therapy were less likely to use PDE5I (OR 0.74, 95% CI 0.70–0.79, P <0.0001).

Conclusion

Men undergoing RP vs. RT, particularly minimally-invasive RP, are more likely to employ IT, suppositories, VED, and PDE5I pharmacotherapy post-treatment.
3-D Volumetric and Vascular Analysis of the Urethrovaginal Space in Young Women With or Without Vaginal Orgasm
Authors: Battaglia Cesare , Nappi Rossella Elena , Mancini Fulvia , Alvisi Stefania , Del Forno Simona , Battaglia Bruno , Venturoli Stefano
Published: January 2010

Introduction

The existence of the G-spot is controversial.

Aim

To evaluate, by the use of three-dimensional (3-D) ultrasonography, the anatomic structures of the urethrovaginal space.

Methods

Nineteen (Group I) eumenorrheic young women who experienced, and 20 (Group II) who did not experience a vaginal orgasm underwent two-dimensional (2-D) and 3-D ultrasonography and color Doppler analysis of the urethrovaginal space and of the clitoris during the early follicular phase of the menstrual cycle.

Main Outcome Measures

2-D ultrasonographic evaluation of the urethrovaginal space, and color Doppler evaluation of the urethrovaginal main feeding artery and dorsal clitoral arteries; 3-D volume calculation of the urethrovaginal space, and 3-D power Doppler analysis of vascular indices of the urethrovaginal space and clitoral body (vascularization index, flow index, vascularization flow index); hormonal evaluation.

Results

The 3-D reconstruction of the urethrovaginal space demonstrated a gland-like aspect with small feeding vessels. The total length (19.1 ± 2.7 mm vs. 17.5 ± 2.1 mm; P = 0.047), measured with 2-D ultrasound, and the 3-D mean volume (0.59 ± 0.13 mL vs. 0.26 ± 0.07 mL; P <0.001) of the structures contained in the urethrovaginal space were significantly higher in Group I than in Group II. The mean time since the last intercourse was 31 ± 9 hours in Group I and 18 ± 3 hours (P = 0.033) in Group II. The urethrovaginal space vascularization, the clitoral volume and vascularization, and the circulating hormonal values did not significantly differ among the two groups. The mean volume of the structures contained in the urethrovaginal space was correlated with time since intercourse (r = 0.685; P = 0.021) and with serum testosterone (r = 0.637; P = 0.032) and androstenedione (r = 0.744; P = 0.011).

Conclusions

The structures we observed in the urethrovaginal space have a gland-like aspect and their volume is correlated with both serum androgen concentrations and time since intercourse.
X‐Ray Tomographic Characterization of the Macroscopic Porosity of Chemical Vapor Infiltration SIC/SIC Composites: Effects on the Elastic Behavior
Authors: Gélébart Lionel , Chateau Camille , Bornert Michel , Crépin Jérôme , Boller Elodie
Published: January 2010

This paper focuses on the characterization of the macroporosity, the porosity among the tows, observed in chemical vapor infiltration composites and on its effect on the thermo‐mechanical behavior. The experimental characterization of macroporosity is performed using an X‐ray tomography technique. Numerical 3D images are used to describe the distribution of macroporosity with respect to the position of the plies. It is clearly established that the stacking of the plies has a significant effect on the porosity distribution. As a consequence for the micromechanical modelling, a unique element that contains only one ply is not representative of the porosity distribution and is not sufficient to evaluate the “effective” mechanical properties; several volume elements (VE), called “statistical volume elements (SVE),” with at least two plies per VE have to be used in order to account for the variability of the stacking of the plies. Finally, such SVE are directly extracted from the tomographic image and the “effective” elastic behavior is evaluated from the average of the “apparent” behavior evaluated on each SVE. In spite of their quite important size, the “apparent” behaviors evaluated for each SVE exhibit important fluctuations.
Pyrosequencing reveals a contrasted bacterial diversity between oak rhizosphere and surrounding soil
Authors: Uroz Stéphane , Buée Marc , Murat Claude , Frey‐Klett Pascale , Martin Francis
Published: January 2010

Several reports have highlighted that forest soil samples are more phylum‐rich than agricultural soil samples. However, little is known about the structure and richness of the bacterial communities in forest soil. Using high‐throughput next generation 454 pyrosequencing, we deeply investigated the diversity of bacterial communities colonizing the oak rhizosphere niche and the surrounding soil. From three spatially independent soil samples, we obtained over 300 000 partial 16S rRNA gene sequences. The most abundant bacterial groups were the Acidobacteria, Proteobacteria and unclassified bacteria. Multifactorial analysis of the relative proportions of the different phyla revealed a net differentiation of the bacterial communities present in the rhizosphere and soil environments, suggesting an oak rhizosphere effect. Significantly more β‐, γ‐ and unclassified Proteobacteria inhabited the rhizosphere when compared with the surrounding soil. Conversely, significantly more unclassified bacteria were detected in the bulk soil than in the rhizosphere, demonstrating that the soil remains a challenging reservoir of complexity. This work increases our understanding of the niche effect on bacterial diversity and on the rare phylogenetic groups inhabiting the soil.
Identification of the current generator underlying cholinergically induced gamma frequency field potential oscillations in the hippocampal CA3 region
Authors: Oren Iris , Hájos Norbert , Paulsen Ole
Published: January 2010

Gamma frequency oscillations (30–100 Hz) are prominent in the hippocampal EEG signal during active network states. An intrahippocampal gamma generator has been identified in the CA3 region. To understand the mechanism of oscillation generation, both the rhythm and the current generators must be identified. While earlier work has elucidated mechanisms of rhythm generation, little attention has been given to identifying the CA3 gamma current generator. Here, we aimed to identify a current generator underlying cholinergically induced gamma frequency oscillations in vitro. To this end, we analysed the instantaneous fluctuations in the wavelet amplitude of the field potential oscillation recorded in the stratum pyramidale, and concomitantly recorded action potentials and synaptic input in individual, anatomically identified neurons. The data revealed that perisomatic inhibitory currents in pyramidal cells generated the majority of the field potential. Pyramidal cell action currents also contributed to the field. In contrast, we found no evidence that excitatory currents contribute significantly to the field oscillations in this model. The moment‐by‐moment analysis of the dynamics of the field potential presented here provides insight into the distinct contributions of synaptic and action currents to the EEG signal and sheds light on the changing balance of excitation and inhibition during cholinergically induced gamma frequency oscillations.
Transient Methods of Thermal Properties Measurement on Fibrous Materials
Authors: Lei Zuo , Zhu Sukang , Pan Ning
Published: January 2010

Fibrous material is a complex porous medium and steady test methods are the main test approaches we currently depend on to study the heat transfer properties. The application of unsteady test methods on fibrous material is still not mature. In this paper, some systematic studies are taken to investigate this problem. By analyzing the main factors impacting the test results, it is found that the local heat convection potentially excited by imposing test temperature can be avoided by limiting the internal temperature gradient and the so-called dual-phase lagging effects are negligible so that the feasibility of the unsteady test method is verified via both theoretical analysis and experimental data.
Effects of Negative Biaxial Loadings and Notch on Failure Assessment Diagrams
Authors: Ragupathy K. , Ramesh K. , Hall D.
Published: January 2010

The failure assessment diagram (FAD) is a simplified and robust flaw assessment methodology, which simultaneously connects two dominant failure criteria: linear elastic fracture mechanics on one end and plastic collapse on the other end. This interaction is in the realm of elastic-plastic fracture mechanics. It is popularly known as the R6 approach, which graphically characterizes the impact of plasticity on crack driving force. In recent years, there has been continuous interest in using FADs to assess the failure of cracked structures subjected to biaxial loadings. Biaxiality is defined as the ratio of stress applied parallel and normal to the crack. Some pressure loaded aircraft components operate under negative biaxial ratios up to −0.5. In this paper, a detailed study on FAD was conducted using finite element analysis computed J-integral methods to investigate the effect of biaxial loading using different FAD approaches for geometries with notches. Geometries with a crack that emanates at a fillet region were simulated with various biaxial loading ratios from −0.5 to +0.5 using 2014-T6 material. FAD curves were numerically generated for cracks at notched regions subjected to various biaxial loadings using J-integral values from finite element analyses. These results were compared with standard FAD approaches. All comparison studies were made between uniaxial and biaxial loading cases with FAD curves created using four different crack sizes. Under small scale yielding, this study clearly shows that FAD curves are not influenced by negative biaxial loading at low load (up to 40% of yield strength). It was clearly confirmed that the majority of previously developed analytical FAD curves do not effectively account for notch and plasticity effects due to negative biaxiality. Based on this study, tension normal to the crack and compression parallel to the crack is the worst combination, and it has a very pronounced effect on FAD curve shapes. The standard analytical FAD curves are nonconservative compared with the approach recommended here, particularly under the worst case condition. FAD curves developed are shown to predict lower failure loads as compared with the currently accepted analytical FAD approaches defined in existing standards, e.g., R6 and API 579. The impact of negative biaxial loading can be investigated directly using a J-integral FAD approach but can be compared with ease by plotting both approaches in a FAD format.
Geoacoustic inversions and localizations with adaptively beamformed data from a surface ship of opportunity source
Authors: Stotts Steven A. , Koch Robert A.
Published: January 2010

A technique has been developed for incorporating adaptively beamformed (ABF) data into geoacoustic inversions and source localizations based on matched-field processing. Rather than adaptively adjusting matched-field weights, for this paper ABF processing is applied to construct subaperture beam data from which the inversions and localizations are derived. This application of ABF processing to inversion and localization is successfully demonstrated with data collected on a horizontal line array from a surface ship of opportunity source (SSOS). When measured data representing noise from one or more interfering sources at various levels are injected into the data collected from the SSOS, the inversion processing with ABF subaperture data is successful at interferer noise levels exceeding the SSOS levels by 10–13dB and for which the inversion processing with conventionally beamformed data fails.
Thermal effects generated by high-intensity focused ultrasound beams at normal incidence to a bone surface
Authors: Nell Diane M. , Myers Matthew R.
Published: January 2010

Experiments and computations were performed to study factors affecting thermal safety when high-intensity focused ultrasound (HIFU) beams are normally incident (i.e., beam axis normal to the interface) upon a bone/soft-tissue interface. In particular, the temperature rise and thermal dose were determined as a function of separation between the beam focus and the interface. Under conditions representative of clinical HIFU procedures, it was found that the thermal dose at the bone surface can exceed the threshold for necrosis even when the beam focus is more than 4 cm from the bone. Experiments showed that reflection of the HIFU beam from the bone back into the transducer introduced temperature fluctuations of as much as ±15% and may be an important consideration for safety analyses at sufficiently high acoustic power. The applicability of linear propagation models in predicting thermal dose near the interface was also addressed. Linear models, while underpredicting thermal dose at the focus, provided a conservative (slight overprediction) estimate of thermal dose at the bone surface. Finally, temperature rise due to absorption of shear waves generated by the HIFU beam in the bone was computed. Modeling shear-wave propagation in the thermal analysis showed that the predicted temperature rise off axis was as much as 30% higher when absorption of shear waves is included, indicating that enhanced heating due to shear-wave absorption is potentially important, even for normally incident HIFU beams.
Suitable reverberation times for halls for rock and pop music
Authors: Adelman-Larsen Niels Werner , Thompson Eric R. , Gade Anders C.
Published: January 2010

The existing body of literature regarding the acoustic design of concert halls has focused almost exclusively on classical music, although there are many more performances of popular music, including rock and pop. Objective measurements were made of the acoustics of 20 rock music venues in Denmark and a questionnaire was used in a subjective assessment of those venues with professional rock musicians and sound engineers as expert listeners. Correlations between the measurements show that clarity, including bass frequencies down to 63Hz, is important for the general impression of the acoustics of the hall. The best-rated halls in the study have reverberation times that are approximately frequency independent from 0.6to1.2s for hall volumes from 1000to6000m3. The worst rated halls in the study had significantly higher reverberation times in the 63 and 125Hz bands. Since most audiences at rock concerts are standing, absorption coefficients were measured with a standing audience from 63Hzto4kHz. These measurements showed that a standing audience absorbs about five times as much energy in mid-/high-frequency bands as in low-frequency bands.
The effect of hearing-aid compression on judgments of relative distance
Authors: Akeroyd Michael A.
Published: January 2010

The overall level of a sound is an important auditory cue to distance in rooms, but this cue might be affected adversely by the amplitude compression found in most modern hearing aids because this explicitly changes levels. This prediction was tested using a synthetic-distance design to measure the just-noticeable difference (JND) in distance from distances of 2 or 5m. Twenty-six aided listeners participated. The results did not show any effect of compression ratio upon JNDs. A possible interpretation is that the listeners had acclimatized to the effect their aids have on level.
Distortion product otoacoustic emission phase and component analysis in human newborns
Authors: Abdala Carolina , Dhar Sumitrajit
Published: January 2010

Apical distortion product otoacoustic emissions (DPOAEs) are comprised of at least two components, as evidenced by the interference pattern of alternating maxima and minima known as fine structure. DPOAE fine structure is produced by the shifting phase relationship in the ear canal, between the generator and characteristic frequency (CF) component of the response. Each component arises from a different cochlear region and, according to theory, reflects a distinct generation mechanism. The analysis of DPOAE components and phase in newborns may provide a window into targeted aspects of cochlear physiology during development. 2f1−f2 DPOAE fine structure was recorded from 15 adults and 14 newborns using a swept-tone technique. DPOAE group delay, as well as magnitude and phase of each component, was compared between age groups. Results show narrower fine structure spacing, a longer group delay (steeper phase gradient) in low frequencies, and a stronger relative contribution from the CF component in newborns. The prolonged group delay for low-frequency DPOAEs could indicate immature basilar membrane motion in the apex of the cochlea and warrants further investigation. The enhanced contribution from the CF component may have implications for clinical practice as well as for theories of cochlear maturation.
Impaired αIIbβ3Integrin Activation and Shear-Dependent Thrombus Formation in Mice Lacking Phospholipase D1
Authors: Elvers Margitta , Stegner David , Hagedorn Ina , Kleinschnitz Christoph , Braun Attila , Kuijpers Marijke E. J. , Boesl Michael , Chen Qin , Heemskerk Johan W. M. , Stoll Guido , Frohman Michael A. , Nieswandt Bernhard
Published: January 2010

In the absence of PLD1, platelets do not form stable aggregates under high shear conditions.
Targeting the Resistance
Authors: Gough Nancy R.
Published: January 2010

A screen of irreversible inhibitors targeting the drug-resistant mutant form of the EGFR yields new candidates for treatment of non–small-cell lung cancer.
Efficacy of Rifampin and Its Combinations with Imipenem, Sulbactam, and Colistin in Experimental Models of Infection Caused by Imipenem-Resistant
Acinetobacter baumannii
Authors: Pachón-Ibáñez María E. , Docobo-Pérez Fernando , López-Rojas Rafael , Domínguez-Herrera Juan , Jiménez-Mejias Manuel E. , García-Curiel Andrés , Pichardo Cristina , Jiménez Luis , Pachón Jerónimo
Published: January 2010

There are currently no defined optimal therapies available for multidrug-resistant (MDR)
Acinetobacter baumannii
infections. We evaluated the efficacy of rifampin, imipenem, sulbactam, colistin, and their combinations against MDR
A. baumannii
in experimental pneumonia and meningitis models. The bactericidal
in vitro
activities of rifampin, imipenem, sulbactam, colistin, and their combinations were tested using time-kill curves. Murine pneumonia and rabbit meningitis models were evaluated using the
A. baummnnii
strain Ab1327 (with MICs for rifampin, imipenem, sulbactam, and colistin of 4, 32, 32, and 0.5 mg/liter, respectively). Mice were treated with the four antimicrobials and their combinations. For the meningitis model, the efficacies of colistin, rifampin and its combinations with imipenem, sulbactam, or colistin, and of imipenem plus sulbactam were assayed. In the pneumonia model, compared to the control group, (i) rifampin alone, (ii) rifampin along with imipenem, sulbactam, or colistin, (iii) colistin, or (iv) imipenem plus sulbactam significantly reduced lung bacterial concentrations (10.6 ± 0.27 [controls] versus 3.05 ± 1.91, 2.07 ± 1.82, 2.41 ± 1.37, 3.4 ± 3.07, 6.82 ± 3.4, and 4.22 ± 2.72 log
10
CFU/g, respectively [means ± standard deviations]), increased sterile blood cultures (0% versus 78.6%, 100%, 93.3%, 93.8%, 73.3%, and 50%), and improved survival (0% versus 71.4%, 60%, 46.7%, 43.8%, 40%, and 85.7%). In the meningitis model rifampin alone or rifampin plus colistin reduced cerebrospinal fluid bacterial counts (−2.6 and −4.4 log
10
CFU/ml). Rifampin in monotherapy or with imipenem, sulbactam, or colistin showed efficacy against MDR
A. baumannii
in experimental models of pneumonia and meningitis. Imipenem or sulbactam may be appropriate for combined treatment when using rifampin.
Source of Nitrous Oxide Emissions during the Cow Manure Composting Process as Revealed by Isotopomer Analysis of and
amoA
Abundance in Betaproteobacterial Ammonia-Oxidizing Bacteria
Authors: Maeda Koki , Toyoda Sakae , Shimojima Ryosuke , Osada Takashi , Hanajima Dai , Morioka Riki , Yoshida Naohiro
Published: January 2010

A molecular analysis of betaproteobacterial ammonia oxidizers and a N
2
O isotopomer analysis were conducted to study the sources of N
2
O emissions during the cow manure composting process. Much NO
2
−
-N and NO
3
−
-N and the
Nitrosomonas europaea
-like
amoA
gene were detected at the surface, especially at the top of the composting pile, suggesting that these ammonia-oxidizing bacteria (AOB) significantly contribute to the nitrification which occurs at the surface layer of compost piles. However, the
15
N site preference within the asymmetric N
2
O molecule (SP = δ
15
N
α
− δ
15
N
β
, where
15
N
α
and
15
N
β
represent the
15
N/
14
N ratios at the center and end sites of the nitrogen atoms, respectively) indicated that the source of N
2
O emissions just after the compost was turned originated mainly from the denitrification process. Based on these results, the reduction of accumulated NO
2
−
-N or NO
3
−
-N after turning was identified as the main source of N
2
O emissions. The site preference and bulk δ
15
N results also indicate that the rate of N
2
O reduction was relatively low, and an increased value for the site preference indicates that the nitrification which occurred mainly in the surface layer of the pile partially contributed to N
2
O emissions between the turnings.
Cryptococcus neoformansVariants Generated by Phenotypic Switching Differ in Virulence through Effects on Macrophage Activation
Authors: Guerrero A. , Jain N. , Wang X. , Fries B. C.
Published: January 2010

Macrophages have a central role in the pathogenesis of cryptococcosis since they are an important line of defense, serve as a site for fungal replication, and also can contribute to tissue damage. The objective of this study was to investigate the interaction of macrophages with cells from smooth-colony variants (SM) and mucoid-colony variants (MC) arising from phenotypic switching ofCryptococcus neoformans. Alveolar macrophages (AMs) isolated from SM- and MC-infected mice exhibited differences in gene and surface expression of PD-L1, PD-L2, and major histocompatibility class II (MHC-II). PD-L1 and PD-L2 are the ligands for PD1 and are differentially regulated in Th1- and Th2-type cells. In addition, macrophage activation in SM- and MC-infected mice was characterized as alternatively activated. Flow cytometric and cytokine analysis demonstrated that MC infection was associated with the emergence of Th17 cells and higher levels of interleukin-17 (IL-17) in lung tissue, which were reduced by AM depletion. In conclusion, our results indicate that macrophages play a significant role in maintaining damage-promoting inflammation in the lung during MC infection, which ultimately results in death.
Superdormant Spores of
Bacillus
Species Germinate Normally with High Pressure, Peptidoglycan Fragments, and Bryostatin
Authors: Wei Jie , Shah Ishita M. , Ghosh Sonali , Dworkin Jonathan , Hoover Dallas G. , Setlow Peter
Published: January 2010

Superdormant spores of
Bacillus cereus
and
Bacillus subtilis
germinated just as well as dormant spores with pressures of 150 or 500 MPa and with or without heat activation. Superdormant
B. subtilis
spores also germinated as well as dormant spores with peptidoglycan fragments or bryostatin, a Ser/Thr protein kinase activator.
Applications of research on ductility of structures
Authors: Kemp R.
Published: January 2010

A limit states criterion of ductility is described for nonlinear behaviour of structural members in flexure. Experimental results and theoretical models are reported for the behaviour of steel and composite continuous beams, portal frames, and continuous steel pipes. The ductility criterion is used to identify the basis for analyzing the load effects and resistances of these elements. Key words: limit states, ductility, analysis, design, beams, pipes, steel, composite, resistance.
Arrangement of interconnectors for starred angle compression members
Authors: Temple Murray C. , Sakla Sherief S. S. , Stchyrba David , Ellis Douglas
Published: January 2010

Starred angles are commonly used as web members in trusses. Standards contain requirements which specify the number of interconnectors to be used, but most standards do not specify a preferred arrangement for the interconnectors. When plates are used as interconnectors, three arrangements — aligned, alternating, or cruciform — are possible. Nine starred angles, three with each arrangement of interconnectors, were tested. A finite element analysis was also conducted. It was determined that the arrangement of the interconnectors did not affect the load-carrying capacity of the starred angles. Key words: angles, buckling, building (codes), columns (structural) interconnection, starred angle.
Biological phosphorus removal at temperatures from 3 to 10 °C — a full-scale study of a sequencing batch reactor unit
Authors: Marklund Stefan , Morling Stig
Published: January 2010

Low temperature biological phosphorus removal technology was tested at a small village wastewater treatment plant near the Arctic circle. An aeration basin in a conventional activated sludge step was retrofitted to a sequencing batch reactor with a maximum volume of approximately 27 m3. The study period was November 1989 to June 1991. The wastewater temperature varied between 3 and 10 °C during one full year and was below 5 °C during approximately 240 days of the year. A total sequencing batch reactor cycle time of 6–12 hours produced a phosphorus reduction of 70–80%. During the same time, biochemical oxygen demand (BOD7) reductions varied between 70% and 90%. These reductions were achieved at supernatant suspended solid concentrations of 20–30 mg/L. Effluent soluble phosphorus concentrations were usually lower than 1.0 mg/L at water temperatures down to 5 °C. At 4 °C, a sharp increase to greater than 2.0 mg/L was evident. Supernatant soluble BOD7 was less than 8 mg/L and was found to be independent of temperature. Key words: biological wastewater phosphorus removal, sequencing batch reactor, cold climate.
Hydrotechnical studies of Peter's River
Authors: Lye Leonard M. , Sharp James J.
Published: January 2010

Peter's River in central Newfoundland supplies water to the town of Botwood from an intake located at a point just upstream of a right-angled bend. The pumphouse is situated on the outer bank of the river and is constructed on a foundation of sandy silt. In 1983, a large flood eroded part of the bank and removed vegetation which had provided a protective cover. Progressive erosion then threatened the pumphouse and forced an engineering assessment of the situation. This was conducted in the winter of 1984–1985 and included the prediction of the 50- and 100-year floods from the minimal data (4 years of records) which were then available. Estimates were made of velocities and flood levels, and various protection schemes were considered.The installation of a revetment in 1986 stabilized the bank, but icing on the intake had always caused problems and these continued unabated. In winter, frazil ice adhered to the submerged intake structure and was drawn into the pumps causing frequent shutdowns. Various solutions, including electrical heating, were considered. However, in 1991, a decision was made to install infiltration pipes below the stream bed, to raise water levels with a small broad crested weir and to disconnect the existing intake. Flow estimates were again required, both for construction purposes and for responding to the Department of Fisheries requirement that there would be no immediate or long-term harm to fish habitat.This paper provides a brief description of the general problems, but focuses primarily on the methods used, 8 years apart, to estimate flood data. These methods were intended to be relatively unsophisticated, but were consistent with the magnitude of the river and the relatively small scale of the proposed works. In the study conducted in 1984–1985, only 4 years of records were available and the estimation of the 50- and 100-year floods relied strongly on the use of regional equations, the development of unit hydrographs, and one large recorded flood. The more extensive record available in 1991 permitted some more sophisticated statistical techniques. However, the large flood which occurred in 1983 still caused considerable difficulty, and the results of the analysis varied according to how this flood was included. Despite these difficulties, it was shown that the estimates made in 1984 were not unreasonable. Key words: Peter's River, Newfoundland, flood estimation, regional equations, censored maximum likelihood method, low gauging ratios.
Comparison of near-field mixing zone models for multiport diffusers in the Great Lakes
Authors: Tsanis I.K. , Valeo C. , Diao Y.
Published: January 2010

This paper presents a review of near-field mixing zone models and compares their performance with common outfall diffuser examples in the Great Lakes. The results of initial dilutions for three types of multiport diffusers, based on the Ontario Ministry of Environment (MOE) guidelines and recommendations, are compared with those calculated by using the U.S. Environmental Protection Agency (EPA) models. These models include five integral-type models (UPLUME, UOUTPLM, UDKHDEN, UMERGE, and ULINE) and a "length scale" type expert system (CORMIX2). Results based on the first four EPA integral models give higher initial dilutions when compared to results based on CORMIX2 and the MOE guidelines, ULINE gives unrealistically low dilutions. Excluding UPLUME, the initial dilutions given by the other EPA models increase with increasing ambient current. Alternating diffusers generally give lower initial dilutions than the staged and unidirectional diffusers, while unidirectional diffusers produce the highest of the three. Results from the computation tests based on the mixing models can aid in more reasonable and economical diffuser designs that still meet the requirement of initial dilution criteria. While all the models selected for this study have limitations, CORMIX2 is preferred for most Great Lakes applications. It can be applied to all four types of multiport diffusers and can handle different types of ambient stratification, bottom and shore attachment, wake effects and dead zones, plume trapping and far-field behaviour. CORMIX2 predictions compare well with laboratory data and very limited field data. Given the complexity of the problem, more field studies should be performed for further validation of the models. Key words: mixing zone, multiport diffusers, initial dilution.
The cost-effectiveness of curve flattening in Alberta
Authors: Talarico R. J. , Morrall J. F.
Published: January 2010

Rehabilitation and restoration improvements on highways typically involve widening lane and shoulder widths, as well as revisions to the superelevation rate. This upgrading approach may sometimes neglect the possibility of flattening horizontal curves, which may result in safer, more cost-effective designs. Aside from the obvious safety benefits for highway travellers, additional benefits may occur in terms of improved traffic operations of intersections on curves. This paper describes the findings of a research project which was conducted to determine the maximum side friction available for a range of roadway curvatures, vehicle speeds, and vehicle types.A three-axis accelerometer and a ball bank indicator were installed in seven test vehicles. Lateral accelerations and ball bank readings were recorded as test vehicles traversed test curves at constant speeds. These data were used to determine the margin of safety provided on dry, wet, and icy pavements.It was found that motorists demand high levels of side friction on sharp curves. In fact, curvatures sharper than 500 m provide very low margins of safety against skidding. Since improved superelevation rates are unlikely to increase the margin of safety to a sufficient level, the cost-effectiveness of curve flattening for rural highways in Alberta was estimated for a range of traffic volumes and central angles. Key words: side friction, margins of safety, horizontal curves, 3-R projects, cost-effectiveness of curve flattening.
Glulam rivets in radiata pine
Authors: Buchanan Andrew H. , Lai James C.
Published: January 2010

Glulam rivets are special nails for making high strength connections in timber structures. This paper describes an investigation of glulam rivet behaviour in radiata pine timber grown in New Zealand. Test results are compared with those on Canadian species, and with several international codes. The European yield theory is shown to give excellent prediction of glulam rivet strength in those connections where wood tension failures do not occur. Simple techniques for obtaining rivet bending strength and wood embedment strength are described, to provide input to the yield theory equations. Key words: fastenings, glulam, laminated, nails, pine, radiata, rivets, timber, wood.
On the dynamic foundation factor for the National Building Code of Canada: low to medium rise buildings
Authors: Heidebrecht A. C. , Rutenberg A.
Published: January 2010

Site-specific seismic response factors for low-period building structures are presented as an alternative to the recently proposed foundation factor F* for inclusion in the seismic provision of the National Building Code of Canada. These factors are not explicit functions of the site vibration period, and, therefore, are more suitable for the design of small to medium rise buildings for which only limited site investigations are routinely carried out. Key words: earthquake engineering, design spectra, site-specific, building codes.
Review of NBCC earthquake-resistant design requirements for cladding connectors
Authors: Bruneau Michel , Cohen Julie Mark
Published: January 2010

As a consequence of recent increases in the severity of seismic design force requirements in Canada, practicing engineers who design cladding connectors should be concerned with their seismic resistance. The current design requirements of the 1990 edition of the National Building Code of Canada for nonstructural components call for unduly high prescribed design forces for the cladding connectors without providing justification, commentary, or substantiation for this constraint, nor guidance on how this is to be achieved. This paper offers some rationalization of these stringent design requirements based on a review of their evolution, outlines some of the shortcomings of the current design approach, recommends possible abatements of the requirements in special cases, and points toward future directions and alternate philosophies for the design of cladding connectors. In particular, the following are recommended: (i) the scope of Part 4 of the National Building Code of Canada should be modified to specifically indicate that cladding connectors are to be designed by a professional engineer, (ii) the latest cladding-connector seismic-resistant design philosophy of the Structural Engineers Association of California should be incorporated into the National Building Code of Canada; (iii) a distinction should be made between out-of-plane and in-plane cladding-connector seismic-resistant design requirements; (iv) a commentary should be written on cladding-related seismic-resistant design issues to clearly state current philosophy, uncertainties, and limits of knowledge be included in the building code, and (v) standardized seismic-resistant cladding connectors be developed with capacities to meet prescribed levels of ductile behavior and interstory drifts and widely distributed to the profession. Key words: cladding, connectors, earthquake, design, code, seismic.
Relaxation behaviour of prestressed wood assemblies. Part 1: Experimental study
Authors: Quenneville Pierre , Dalen Karl Van
Published: January 2010

Transverse prestress has been found to increase significantly the strength and stiffness of laminated timber bridge decks and timber joints using timber connectors. A fundamental requirement to the successful use of prestressing with timber is the ability to predict the reduction of prestress with time for transversely prestressed timber applications. The loss of prestress with time for transversely prestressed assemblies was studied analytically and experimentally. In the experimental study, Douglas fir specimens were subjected to two different relative humidity levels and to various stressing histories. The relaxation behaviour and the moisture content of the specimens were continuously monitored for 9 months. Results show that the relaxation behaviour of transversely prestressed wood is affected by the relative humidity level in the surrounding environment and by the stressing frequency. The magnitude of the observed prestress losses and the graphs showing prestress levels and moisture content of specimens as a function of time under various externally imposed conditions are presented. Key words: connections, wood, prestress, Douglas fir, rheology.
Estimating the probabilities of combined events
Authors: Russell S. O. Denis , Lee Ken-Beck
Published: January 2010

In coastal areas, high water levels often result from a combination of events such as high tide and high flow. For such areas, design engineers often have to estimate the water level that would be exceeded with a specified probability. Several methods, including the traditional ad-hoc way, of making such estimates are compared for simple situations, where it is possible to obtain exact answers by numerical integration. Key words: floods, flood probability, combined probability, probability estimation, design water level.
A model for proactive mediation of construction disputes
Authors: Hartman Francis T. , Jergeas George F.
Published: January 2010

Alternative dispute resolution methods remain an area of interest and study because of the continued increase in the incidence of disputes, be they claims or litigation. Practice in the industry tends to stimulate litigation if negotiation of claims is unsuccessful. At variance with this is the declared preference of construction industry practitioners for mediation over arbitration and for arbitration over litigation. Mediation has had a high success rate when used in construction dispute resolution. The cost of mediation is significantly lower than litigation or arbitration. The probability of the parties to the dispute being able to work together effectively after the dispute has been resolved is higher, and the dispute can be resolved more quickly than by arbitration or litigation. This paper presents the findings of a study undertaken to identify a better process for construction contracting. An essential part of the new process is the use of proactive mediation. Proactive mediation is the use of a mediator prior to a dispute arising to help identify and address potential problems before they become difficult or unsolvable issues. The proposed methodology has been tested through a process which obtained the input of over 60 senior industry practitioners. Key words: mediation, construction management, contracts, claims, cost reduction, alternate dispute resolution, risk management.
Effects of ice on the hydraulics of Mackenzie River at the outlet of Great Slave Lake, N.W.T.: a case study
Authors: Hicks Faye , Chen Xiaobing , Andres David
Published: January 2010

The effects of ice on the conveyance characteristics of the Mackenzie River at the outlet of Great Slave Lake are modeled on the basis of cross section surveys, discharge measurements, and water surface profiles taken during open water and ice covered conditions. The calibrated bed roughness values, expressed in terms of Mannings n, range from 0.020 to 0.030. Based on measured ice thicknesses ranging from 0.6 to 1.2 m in the study reach upstream of Providence Narrows, the calibrated roughness of the 1992 late winter ice cover is 0.015. Discharge estimates, based on this late winter ice cover calibration, measured water surface profiles, and documentation of major ice movements during April and May of 1992, show relatively good agreement with the discharge measurements taken at the same time. The analysis indicates that flow in the channel just downstream of Great Slave Lake is uniform under both open water and ice covered conditions. However, stage–discharge relationships at the Water Survey of Canada gauging station are affected by variable backwater conditions, particularly when an ice accumulation develops in Providence Rapids. Key words: ice, breakup, backwater curves, hydraulic resistance, river.
A comprehensive field study of residential concrete flatwork
Authors: Gifford P. M. , Ward M. A. , Langan B. W.
Published: January 2010

The primary objective of this project was to establish procedures necessary to improve and maintain the quality and performance of exposed residential concrete flatwork. While this classification of concrete is covered in the Canadian Standards Association specifications, the applicable sections are seldom enforced on the site. The project involved visits to 123 sites selected from the daily rosters of the six participating supply companies. At the sites a series of concrete tests were performed, and site conditions and finishing practices were observed and noted. The information collected for each site included the air content and slump of the concrete together with an evaluation of the site and finishing deficiencies. Compressive strength cylinders were taken at those sites as felt necessary. The project has demonstrated how a ready-mixed concrete supply industry can be organized in a cooperative effort and by way of a data feedback system involving drivers and plants to ensure that a quality product is repeatedly delivered and placed at job sites. The continuing education of all individuals involved in the total process is an important goal, particularly the finishing aspect. This paper is intended to meet part of this objective. Key words: residential flatwork, air content, field testing, workmanship, workability, compressive strength.
Nonlinear behaviour of bottom plate in cylindrical liquid storage tanks for seismic applications
Authors: Lau David T. , Zeng Xianguang
Published: January 2010

The paper presents a simplified pseudostatic approach to model the nonlinear behaviour of the bottom plate in unanchored cylindrical liquid storage tanks for seismic applications. In this paper, the problem of axisymmetric uplift of the bottom plate is studied for tanks supported on both rigid and elastic Winkler foundations. In the analysis, the bottom plate is modelled by one-dimensional beam and two-dimensional plate models. By comparing the results, it is found that the one-dimensional beam model gives accurate results acceptable for all practical design purposes, in view of the many other uncertainties in the tank uplift problem. The analysis results also show that the support foundation flexibility may have significant effects on the uplift behaviour of the tanks. Based on the axisymmetric uplift results, the paper then presents a simple approach to model the seismic partial uplift problem of unanchored tanks by means of nonlinear springs. Modelling parameters for the nonlinear springs are generated for dynamic uplift response analysis. Sensitivities of the uplift behaviour and the nonlinear spring modelling parameters to the tank height-to-radius ratio and the soil stiffness are also studied. Key words: axisymmetric uplift, cylindrical tanks, earthquakes, pressure vessel, shell, soil effect.
Seismic fracture analysis of concrete gravity dams
Authors: Léger P. , Bhattacharjee S. S.
Published: January 2010

Nonlinear seismic analyses of a 90 m high concrete gravity dam, assumed to be located in eastern Canada, have been conducted using a smeared crack finite element model. Reduced frequency-independent added matrices have been used to represent the hydrodynamic and foundation interaction effects. Parametric analyses have been performed to assess the effects of the initial conditions induced by severe winter temperature, and the effects of hydrodynamic and foundation interaction mechanisms, on the nonlinear seismic behaviour of the dam. Key words: gravity dams, nonlinear seismic response, finite element, crack propagation.
Déversements turbulents de matériau granulaire. II. Modélisation numérique
Authors: Lavallée Daniel , Marche Claude , D'Astous Yves
Published: January 2010

The capping of contaminated sediments is a way to isolate them. From experimental results presented in the previous article, and with an impinging jet model, the formation of the mound at the bottom and the risks of resuspension associated with the disposal operations are predicted. Key words: dredging, capping, impinging jet.