bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of sirolimus in the treatment of lymphangioleiomyomatosis: favorable responses in patients with different extrapulmonary manifestations
Authors: Freitas Carolina Salim Gonçalves , Baldi Bruno Guedes , Araújo Mariana Sponholz , Heiden Glaucia Itamaro , Kairalla Ronaldo Adib , Carvalho Carlos Roberto Ribeiro
Published: July 2015

OBJECTIVE: Lymphangioleiomyomatosis (LAM) is a rare disease that is currently considered a low-grade neoplasm with metastatic potential and variable progression. Mammalian target of rapamycin (mTOR) inhibitors, such as sirolimus and everolimus, have recently become a treatment option for LAM patients, especially those with extrapulmonary manifestations. The objective of the present study was to describe a case series of four patients with LAM in Brazil who showed significant improvement, particularly in their extrapulmonary manifestations, after treatment with sirolimus (at 1-4 mg/day). METHODS: We describe four cases of LAM patients with different extrapulmonary manifestations who were treated with sirolimus. RESULTS: After treatment with sirolimus for 12 months, one patient presented resolution of severe chylothorax; one had a significant reduction in renal angiomyolipoma volume; and one showed significant regression of retroperitoneal lymphangioleiomyomas and abdominal lymph node enlargement. After treatment with sirolimus for 6 months, the remaining patient had a significant reduction in the volume of a massive retroperitoneal lymphangioleiomyoma. CONCLUSIONS: Our findings confirm that mTOR inhibitors are beneficial for patients with LAM, especially those with extrapulmonary manifestations, such as renal angiomyolipoma, lymphangioleiomyomas, and chylous effusions. However, certain aspects, such as the optimal dose, duration of treatment, and long-term adverse effects, have yet to be sufficiently clarified for mTOR inhibitors to be incorporated into LAM management protocols.
Cervical Chondrocutaneous Branchial Remnants
Authors: Klockars Tuomas , Kajosaari Lauri
Published: July 2015

Objective

Cervical chondrocutaneous branchial remnants are rare malformations usually found in the lower neck. As high as 76% of patients have been reported to have associated anomalies. We review the literature and report a case series of seven patients with cervical cartilaginous remnants.

Design

A retrospective case series of seven patients identified from the electronic hospital records.

Results

Seven patients with cervical chondrocutaneous branchial remnants were identified (six boys and one girl). Only one of the patients had associated anomalies.

Conclusions

A review of the literature revealed no evidence for sinuses or cysts related to cervical chondrocutaneous branchial remnants. Operative treatment can be postponed to a suitable and safe age. There is marked variation in the reported prevalence of associated anomalies, ranging from 11% to 76%.
Resistance of fly ash–Portland cement blends to thermal shock
Authors: Pyatina Tatiana , Sugama Toshifumi
Published: July 2015

Thermal-shock resistance of high-content fly ash–Portland cement blends was tested in the following ways. Activated and non-activated blends with 80–90% fly ash F (FAF) were left to set at room temperature, then hydrated for 24 h at 85°C and then for an additional 24 h at 300°C, and tested in five thermal-shock cycles (600°C heat – 25°C water quenching). X-ray diffraction (XRD) and thermal gravimetric analyses, along with calorimetric measurements and scanning electron microscope-energy-dispersive X-ray tests demonstrated that the activated blends form more hydrates after 24 h at 300°C, and achieve a higher short-term compressive strength than do non-activated ones. Sodium meta-silicate and soda-ash engendered the concomitant hydration of ordinary Portland cement (OPC) and class F fly ash (FAF), with the formation of mixed crystalline FAF–OPC hydrates and FAF hydrates, such as garranite, analcime and wairakite, along with the amorphous FAF hydration products. In sodium sulfate-activated and non-activated blends separate OPC (tobermorite) and FAF (amorphous gel) hydrates with no mixed crystalline products formed. The compressive strength of all tested blends decreased by nearly 50% after five thermal-shock test cycles. These changes in the compressive strength were accompanied by a marked decrease in the intensities of XRD patterns of the crystalline hydrates after the thermal shock. There was no significant difference in the performance of the blends with different activators.
Shear capacity of RC beams at elevated temperatures
Authors: Youssef M. A. , Diab M. A. , El-Fitiany S. F.
Published: July 2015

Fire safety is a critical criterion for designing reinforced concrete structures. With the introduction of performance-based design, structural engineers need design tools to assess the capacity of different elements during fire exposure. This paper proposes an analytical method to predict the shear capacity of reinforced concrete beams exposed to elevated temperatures. The proposed method extends the use of existing ambient temperature methods by accounting for the effect of elevated temperatures on material properties. It involves heat transfer analysis, evaluation of the material properties at elevated temperatures, and application of the modified compression field theory to estimate the shear capacity. The method is validated using experimental results by others. A parametric study is then conducted to investigate the effects of different parameters on the shear capacity of reinforced concrete beams exposed to fire.
Seasonality in marine ecosystems: Peruvian seabirds, anchovy, and oceanographic conditions
Authors: Passuni Giannina , Barbraud Christophe , Chaigneau Alexis , Demarcq Hervé , Ledesma Jesus , Bertrand Arnaud , Castillo Ramiro , Perea Angel , Mori Julio , Viblanc Vincent A. , Torres‐Maita Jose , Bertrand Sophie
Published: July 2015

In fluctuating environments, matching breeding timing to periods of high resource availability is crucial for the fitness of many vertebrate species, and may have major consequences on population health. Yet, our understanding of the proximate environmental cues driving seasonal breeding is limited. This is particularly the case in marine ecosystems, where key environmental factors and prey abundance and availability are seldom quantified. The Northern Humboldt Current System (NHCS) is a highly productive, low‐latitude ecosystem of moderate seasonality. In this ecosystem, three tropical seabird species (the Guanay Cormorant Phalacrocorax bougainvillii, the Peruvian Booby Sula variegata, and the Peruvian Pelican Pelecanus thagus) live in sympatry and prey almost exclusively on anchovy, Engraulis ringens. From January 2003 to December 2012, we monitored 31 breeding sites along the Peruvian coast to investigate the breeding cycle of these species. We tested for relationships between breeding timing, oceanographic conditions, and prey availability using occupancy models. We found that all three seabird species exhibited seasonal breeding patterns, with marked interspecific differences. Whereas breeding mainly started during the austral winter/early spring and ended in summer/early fall, this pattern was stronger in boobies and pelicans than in cormorants. Breeding onset mainly occurred when upwelling was intense but ecosystem productivity was below its annual maxima, and when anchovy were less available and in poor physiological condition. Conversely, the abundance and availability of anchovy improved during chick rearing and peaked around the time of fledging. These results suggest that breeding timing is adjusted so that fledging may occur under optimal environmental conditions, rather than being constrained by nutritional requirements during egg laying. Adjusting breeding time so that fledglings meet optimal conditions at independence is unique compared with other upwelling ecosystems and could be explained by the relatively high abundances of anchovy occurring throughout the year in the NHCS.
Preserving Median Filtering Algorithm in Chip Images
Authors: Ming Ding
Published: July 2015

The types and characteristics of noise in chip images were analyzed in this paper. A new kind of details preserving
adaptive median filtering algorithm with directional sub-window was introduced in which the shape and size of
filtering window can be adjusted according to the noise level and the sensitivity can be set by parameter. The filter can effectively
get rid of most of the impulse noise and speckles from the chip image, and improve the accuracy of processing
and analyzing image.
The influence of interlayer interactions on the mechanical properties of polymeric nanocomposites
Authors: Jabbarzadeh Mehrdad , Golkarian Amir
Published: July 2015

In this paper the influence of types of interlayer interactions on the
elastic modules of multilayer graphene sheets (GS) and nanocomposites is
studied. The modeling and investigation of mechanical properties of graphite
layers are performed using molecular mechanics (MM) method. Initially, due to
improving the model and decreasing the amount of computations, three types of
elements such as beam, linear spring and nonlinear spring are used. To
continue, the mechanical properties of multilayers and nanocomposites are
compared using three types of interlayer interactions. Initially, nonlinear
spring defined by Leonard Jones potential is used to define interlayer
interactions (ordinary case). To continue, linear spring with certain
stiffness, to obtain an equal linear spring and also to investigate the
ultimate capacity of interlayer interactions in the force translation, by
increasing the stiffness of linear springs, is employed (chemical change).
Then once by omitting all Van der Waals interactions and defects creation in
graphite layers, they are devoted to create covalent interlayer interactions
(using Morse potential) and another time, Van der Waals and covalent
interlayer interactions are created spontaneously to study the properties of
multilayers and nanocomposites (functionalization). The results are compared
with other available literatures in this case to validate the modeling.
A novel compound isolated from Sclerochloa dura has anti-inflammatory effects
Authors: Bukhari Syed , Feuerherm Astrid , Tunset Hanna , Isaksen Stian , Sæther Mari , Thvedt Thor , Gonzalez Susana , Schmid Rudolf , Brunsvik Anders , Fuglseth Erik , Zlatkovic Bojan , Johansen Berit , Simic Nebojsa
Published: July 2015

The activation of PLA2 by means of pro-inflammatory cytokines results in the
subsequent release of arachidonic acid (AA) and generates eicosanoids, which
further propagate inflammation. By 6the cyclooxygenases (COX1/2) responsible
for the enzymatic conversion of AA to eicosanoids, the non-steroidal
anti-inflammatory drugs are effective in relieving the pain and discomfort of
inflammation. By using AA release assay as a guide for biological and
anti-inflammatory activity, novel compound
1-O-(3-O-linolenoyl-6-deoxy-6-sulfo-?-D-glucopyranosyl)-glycerol (1) together
with five known compounds isovitexin, byzantionoside B, tricin
4?-O-(erythro-?-guaiacylglyceryl) ether 7-O-?-glucopyranoside, 1-O-feruloyl
glycerol and tricin 7-glucoside were isolated from the methanol extract of
the aerial parts of Sclerochloa dura using LC techniques (Sephadex LH-20
column chromatography, preparative HPLC and semi-preparative HPLC). All
isolated compounds were identified using spectroscopic NMR spectroscopy and
MS spectrometry. Novel compound (1) was found to be an effective inhibitor of
AA release with an IC50 value of 0.09 ? 0.03 mg mL-1.
The presence of some humoral immunologic indicators and clinical manifestations in cryoglobulin positive heroin addicts without evidence of hepatitis virus infection
Authors: Simonovska Natasha , Chibishev Andon , Bozinovska Cvetanka , Grchevska Ladislava , Dimitrovski Kocho , Neceva Violeta
Published: July 2015

Introduction. Cryoglobulins are single or mixed immunoglobulins that are
subject to reversible precipitation at low temperatures. Objective. The aims
of this paper were: 1. Comparison of cryoglobulin positive (CP),
cryoglobulin negative (CN) heroin addicts and the control group (CG) in
terms of serum immunoglobulins IgG, IgA and IgM and complement components C3
and C4; 2. Comparison of CP and CN heroin addicts in terms of rheumatoid
factor (RF) and circulating immune complexes (CIC); 3. Assessment of
clinical manifestations in CP heroin addicts. Methods. This is a comparative
study of cases (outpatients) treated at the University Clinic of Toxicology
in Skopje over 3.5 years, from January 2009 to June 2012. In this study 140
heroin addicts without HbsAg were examined, seronegative for HCV and HIV
infections. They were divided into 2 groups: 70 CP and 70 CN heroin addicts.
A previously designed self-administered questionnaire was used as a data
source on participants. All heroin addicts underwent the following analyses:
urea and creatinine in serum; creatinine in urine; proteinuria; 24-hour
proteinuria; IgM, IgG, IgA, C3, C4 ; RF; CIC; creatinine clearance; ECG;
toxicological analyses for opioids in a urine sample; cryoglobulins. In
addition to these 2 groups, IgG, IgA, IgM, C3 and C4 were also examined in
70 healthy subjects (CG). Results. The study showed that there was no
statistically significant difference between CP, CN heroin addicts and CG
regarding the concentration of IgA, IgG, IgM, C3 and C4, and between CP and
CN regarding the concentration of CIC. There was significant difference
between CP and CN regarding the concentration of RF. The following
conditions were significantly more frequently manifested in CP than in CN
heroin addicts: arthralgia, Raynaud?s phenomenon, respiratory difficulties,
neurological disorders, manifested skin changes, hematuria, 24-hour
proteinuria levels, and decreased renal clearance. Conclusion. There were no
differences in concentrations of IgG, IgA, IgM, C3, C4 and CIC, while there
was a difference in concentration of RF between CP and CN heroin addicts.
Clinical manifestations (arthralgias, Raynaud?s phenomenon, respiratory,
neurologic, renal disorders and skin changes) were more common in CP heroin
addicts.
Splenic artery aneurysms: Two cases of varied etiology, clinical presentation and treatment outcome
Authors: Pejkic Sinisa , Tomic Ivan , Opacic Dragan , Pejinovic Luka , Grubor Nikica , Cinara Ilijas , Davidovic Lazar
Published: July 2015

Introduction. Splenic artery aneurysms are potentially lethal lesions. We
report two illustrative cases and discuss etiology, diagnosis and treatment
of these aneurysms. Outline of Cases. Both patients, age 31 and 80 years,
were biparous women. The younger woman, otherwise healthy, was referred from
a local hospital 3 weeks after she underwent a left subcostal laparotomy and
exploration for symptomatic abdominal mass diagnosed by CT. Angiography
established the diagnosis of a large, non-ruptured splenic artery aneurysm.
Elective aneurysmectomy with splenectomy was performed using the approach
through the upper median laparotomy and bursa omentalis. Postoperative course
was uneventful. Histopathology demonstrated cystic medial necrosis with
chronic dissection. The other patient, elderly woman, presented urgently with
acute abdominal pain and syncope and was diagnosed by computed tomography
with a huge, ruptured splenic artery aneurysm. She underwent immediate
aneurysmectomy with splenectomy using the same, above-mentioned approach.
External pancreatic fistula and pancreatic pseudocyst complicated the
postoperative course, requiring open pseudocyst drainage and
cystojejunostomy. After a protracted hospitalization patient eventually
recovered. The pathological diagnosis was atherosclerotic aneurysm.
Conclusion. Splenic artery aneurysms are infrequent lesions, with varied
etiology and clinical presentation. Timely diagnosis and adequate treatment
prevent life-threatening rupture and lessen the risk of operative morbidity
and mortality.
Salt content in ready-to-eat food and bottled spring and mineral water retailed in Novi Sad
Authors: Trajkovic-Pavlovic Ljiljana , Popovic Milka , Bijelovic Sanja , Velicki Radmila , Torovic Ljilja
Published: July 2015

Introduction. Salt intake above 5 g/person/day is a strong independent risk
factor for hypertension, stroke and cardiovascular diseases. Published
studies indicate that the main source of salt in human diet is processed
ready-to-eat food, contributing with 65-85% to daily salt intake. Objective.
The aim of this paper was to present data on salt content of ready-to-eat
food retailed in Novi Sad, Serbia, and contribution of the salt contained in
100 g of food to the recommended daily intake of salt for healthy and persons
with cardiovascular disease (CVD) risk. Methods. In 1,069 samples of
ready-to-eat food, salt (sodium chloride) content was calculated based on
chloride ion determined by titrimetric method, while in 54 samples of bottled
water sodium content was determined using flame-photometry. Food items in
each food group were categorized as low, medium or high salt. Average salt
content of each food group was expressed as a percentage of recommended daily
intake for healthy and for persons with CVD risk. Results. Average salt
content (g/100 g) ranged from 0.36?0.48 (breakfast cereals) to 2.32?1.02
(grilled meat). The vast majority of the samples of sandwiches (91.7%), pizza
(80.7%), salami (73.9%), sausages (72.9%), grilled meat (70.0%) and hard
cheese (69.6%) had a high salt profile. Average amount of salt contained in
100 g of food participated with levels ranging from 7.2% (breakfast cereals)
to 46.4% (grilled meat) and from 9.6% to 61.8% in the recommended daily
intake for healthy adult and person with CVD risk, respectively. Average
sodium content in 100 ml of bottled spring and mineral water was 0.33?0.30 mg
and 33?44 mg, respectively. Conclusion. Ready-to-eat food retailed in Novi
Sad has high hidden salt content, which could be considered as an important
contributor to relatively high salt consumption of its inhabitants.
Phenotypic Characterization of MIP-CreERT1Lphi Mice With Transgene-Driven Islet Expression of Human Growth Hormone
Authors: Oropeza Daniel , Jouvet Nathalie , Budry Lionel , Campbell Jonathan E. , Bouyakdan Khalil , Lacombe Julie , Perron Gabrielle , Bergeron Valerie , Neuman Joshua C. , Brar Harpreet K. , Fenske Rachel J. , Meunier Clemence , Sczelecki Sarah , Kimple Michelle E. , Drucker Daniel J. , Screaton Robert A. , Poitout Vincent , Ferron Mathieu , Alquier Thierry , Estall Jennifer L.
Published: July 2015

There is growing concern over confounding artifacts associated with β-cell–specific Cre-recombinase transgenic models, raising questions about their general usefulness in research. The inducible β-cell–specific transgenic (MIP-CreERT1Lphi) mouse was designed to circumvent many of these issues, and we investigated whether this tool effectively addressed concerns of ectopic expression and disruption of glucose metabolism. Recombinase activity was absent from the central nervous system using a reporter line and high-resolution microscopy. Despite increased pancreatic insulin content, MIP-CreERT mice on a chow diet exhibited normal ambient glycemia, glucose tolerance and insulin sensitivity, and appropriate insulin secretion in response to glucose in vivo and in vitro. However, MIP-CreERT mice on different genetic backgrounds were protected from high-fat/ streptozotocin (STZ)-induced hyperglycemia that was accompanied by increased insulin content and islet density. Ectopic human growth hormone (hGH) was highly expressed in MIP-CreERT islets independent of tamoxifen administration. Circulating insulin levels remained similar to wild-type controls, whereas STZ-associated increases in α-cell number and serum glucagon were significantly blunted in MIP-CreERT1Lphi mice, possibly due to paracrine effects of hGH-induced serotonin expression. These studies reveal important new insight into the strengths and limitations of the MIP-CreERT mouse line for β-cell research.
Experimental study of effects of main process parameters on porosity, track geometry, deposition rate, and powder efficiency for high deposition rate laser metal deposition
Authors: Zhong Chongliang , Biermann Tim , Gasser Andres , Poprawe Reinhart
Published: July 2015

Laser metal deposition (LMD) is an additive manufacturing process. Although much research regarding effects of process parameters on deposition quality has been conducted in recent decades, the studies in this field are still lacking for high deposition rates (>0.3 kg/h) LMD. Most of the previous investigations were based on traditional LMD process, characterized by a low deposition rate (<0.3 kg/h). This paper presents a pilot study to find the answer on the effects of main process parameters on track dimensions and process characteristics in high deposition-rate LMD. Inconel 718 (IN718) powder was used as additive material. Chemical composition, porosity, shape, and morphology of the used powder were analyzed to ensure that the necessary specifications are met. Based on a high deposition-rate LMD process, which has a deposition rate of approximately 2 kg/h, experiments were designed and carried out on a dedicated high deposition-rate LMD experimental setup. Furthermore, effects of main process parameters (laser power, scanning speed, and powder mass flow) on porosity, track geometry, deposition rate, and powder efficiency were investigated. It is found that track porosity decreases with an increase of laser powder or a decrease of powder mass flow; the consistency of cross-sectional porosity is relative poor if laser powder is insufficient or powder mass flow is excessive. The transition between substrate surface and track surface becomes smoother with increasing laser power, increasing scanning speed or decreasing powder mass flow. Deposition rate and powder efficiency keep relatively constant after a significant increase with increased laser power until a certain threshold, but they are not correlated with scanning speed. Deposition rate increases whereas powder efficiency decreases with an increase of powder mass flow.
Poor soils and density‐mediated body weight in deer: forage quality or quantity?
Authors: Lashley Marcus A. , Chitwood M. Colter , Harper Craig A. , Moorman Chris E. , DePerno Chris S.
Published: July 2015

Cervid studies have demonstrated body weight and lactation may be limited in areas with poor‐quality soils, with the underlying mechanism often attributed to poor forage quality resulting from poor soil quality. However, if highly nutritious foods are produced but in limited quantities, selective foraging may alleviate nutritional stressors associated with poor soil productivity when adequate quantities of high‐quality forage are obtained. We tested whether poor soil productivity limits forage from being high quality or conversely limits the abundance of high‐quality forages. To do so, we determined whether nutrient concentrations in selected and non‐selected forages on our poor soil study site met the nutritional requirements of lactating white‐tailed deer Odocoileus virginianus assuming adequate amounts of forage are obtained. Also, we compared body weight of yearling males at a high density (13–17 deer km‐2) and low density (3–5 deer km‐2), because previous studies concluded soils on the study site were too poor for morphometrics (e.g. body weight) to be density‐mediated. Deer selected plant species from each of five forage classes that would meet their nutritional requirements (i.e. assuming adequate forage intake) but also selected for different nutrients across forage classes. Phosphorus was limited in most forages, but deer selected forages that met P‐requirements 10 times more than expected. We demonstrated body weight was 7.3% greater when deer density was low than high. Contrary to previous reports from poor productivity soil regions, deer on our study site should be able to meet lactation requirements when the quantity of high‐quality forage is not limiting, and similarly body weight should be density‐mediated. Hence, management strategies that alter the amount of forage per animal (i.e. decreasing animal density and/or increasing forage abundance) are viable options to promote desirable ungulate morphometrics in poor soil regions.
Simpson’s Paradox in Canadian Police Clearance Rates
Authors: Demers Simon , Rossmo D. Kim
Published: July 2015

Police clearance rates and other forms of aggregated criminal justice data can be susceptible to statistical artefacts such as Simpson’s paradox (Yule-Simpson effect). Simpson’s paradox occurs when a trend apparent in separate data groups reverses itself once the groups are combined. Within 15 years of clearance rate data from the 50 largest Canadian police jurisdictions, 210 instances of Simpson’s paradox were discovered (annual mean = 14.0). These instances included four cases in which a reversal occurred simultaneously in all crime categories and subcategories. This finding suggests the need for caution when using clearance rates as a comparative measure of police performance, particularly between jurisdictions or time periods with different crime mixes. Criminal justice researchers, policy makers, and crime analysts should be aware of Simpson’s paradox and its potential effect on aggregated data. Finally, the possibility of a double reversal must be considered when attempting to resolve Simpson’s paradox.
Investigation of the Self Tempering Effect of Martensite by Means of Atom Probe Tomography
Authors: Sackl S. , Clemens H. , Primig S.
Published: July 2015

Self-tempering effects can be observed in steels with relatively high martensite start temperatures. After the formation of the first martensitic laths, carbon is able to diffuse in these laths during cooling, which can be attributed to sufficiently high temperatures. This effect cannot be observed in laths formed at lower temperatures. In steels containing up to 0.2 m.-% carbon, up to 90 % of the carbon atoms in the martensite segregate to dislocations during quenching. Due to its atomic resolution and sensitivity with respect to light elements, atom probe tomography is very well suited for the investigation of this phenomenon. In this study, the self-tempering effect in a quenched and tempered steel 42CrMo4 with a martensite start temperature of 310 °C is investigated by means of atom probe tomography.
Markov Chain Modeling of Pavement Surfacing
Authors: Hassan Rayya A. , Lin Oliver , Thananjeyan Amutha
Published: July 2015

Suitable performance models are needed for estimating medium- and long-term budgetary requirements to keep bituminous surfacing of the road network in serviceable condition. Long-term deterioration models are used for predicting both the proportions of the network that will require resurfacing and in what years. These predictions can then be used in estimating required budgets. Such models also can indicate the network level of service that can be achieved within various budget scenarios. The research reported here used subjective condition data to develop deterioration models for five types of pavement bituminous surfacing: chip seal, geotextile seal (chip seal with geotextile underlay), dense-graded asphalt, open-graded asphalt, and ultrathin asphalt. The condition data were collected through visual inspection surveys, which were conducted every 2 to 3 years by experienced personnel who followed detailed guidelines. Cracking, stone loss, texture loss, deformation, and patching data were collected for dense-graded, open-graded, and ultrathin asphalt. For chip seal and geotextile seal, binder condition and level data were also collected. The condition ratings of the distresses were then combined into a single measure, the surface inspection rating. Markov chains were used to develop deterioration models of surface inspection rating as a function of surface age for the five surfacing types. These models were validated, and the reasonableness of their predictions was assessed according to practical experience and engineering judgment. The models proved to be practicable because of ease of development and reasonableness of predictions.
Evaluation of the Effect of Rural Road Condition on Agricultural Produce Transportation
Authors: Steyn W. J. vdM. , Nokes B. , du Plessis L. , Agacer R. , Burmas N. , Popescu L.
Published: July 2015

Road condition affects the operations and costs of vehicles that use the infrastructure. Various models of vehicle operating cost provide an indication of the effects of road roughness on fuel consumption, additional damage to a vehicle, and tire wear. These models do not include the effect of road conditions on the condition of and potential damage to transported freight. Such potential damages are mitigated through the use of improved vehicle technologies or packaging. In agricultural transportation, packaging often is not a solution because the use of older vehicle technology on mostly rural roads with lower levels of riding quality is a main contributor to the problem. This paper evaluates quantified effects of the riding quality on low-volume roads on the level of damage to tomatoes in California. The paper is partly based on a study that focused on vehicle–pavement interaction and its effects on the broader California economy. Vehicle responses to road conditions were measured during operations on a range of rural routes. Laboratory experiments were developed to replicate the dominant vibrations of the trucks and to measure the stresses that tomatoes typically undergo at these vibration levels. The damage and failure levels for the tomatoes during transportation were determined, and these damage levels were used to calculate typical costs to agricultural suppliers that are due to road conditions. The problem thus could be quantified and input data provided for a cost–benefit evaluation of the potential maintenance and improvement of various routes used to transport tomatoes.
Comparison of Low-Volume Road Pavement Performance with Results of Accelerated Pavement Testing
Authors: Johnston Marlova Grazziotin , Núñez Washington Peres , Ceratti Jorge Augusto Pereira
Published: July 2015

Weathered basalts are polygonal fragments of various dimensions generally spread in a wide grading envelope. They are found in high-volume portions of basaltic spills where the rock is extremely fractured and where degradation processes prevail over decomposition. This material was used as base and subbase layers of experimental pavement sections tested with a heavy traffic simulator. The same material was used as the base and subbase of a pavement on a low-volume road in Rio Grande do Sul state, Brazil, that was monitored for 10 years. The main conclusion from the study is that the low-volume road pavement presented different forms of surface degradation in comparison with the experimental road tested with the traffic simulator. The design model obtained in the traffic simulator study was used to identify the point at which the pavement started to deteriorate and thereby identify when a maintenance program was needed rather than to predict when the pavement had already fully deteriorated.
Implementation of Preventive Maintenance in Network-Level Optimization
Authors: Cirilovic Jelena , Mladenovic Goran , Queiroz Cesar
Published: July 2015

Application of appropriate preventive maintenance treatments, at the right time, extends the service life of pavements, resulting in benefits to road users through increased ride comfort and safety and to road agencies through the reduction of future maintenance costs and improvement of the network condition. Preventive maintenance treatments usually have been applied on the highly trafficked sections of the Serbian national road network, but they have not been applied on the low-volume part of the network. This study used the Serbian low-volume roads network as a case study to identify appropriate preventive maintenance treatments for low-volume roads, model these into a pavement management system, and assess the potential benefits of their application compared with the current practice. The World Bank's RONET (road network evaluation tools) model, designed to assess the current characteristics of road networks and their future performance according to various levels of interventions (and budgets), was selected for this study. The model was modified for the study to incorporate use of preventive maintenance treatments. Modifications included adjustment of the pavement deterioration curves to incorporate a slower deterioration rate resulting from the application of crack sealing and pothole patching and surface dressings or thin overlays while the pavement was still in good condition. The results indicate that the use of preventive maintenance treatments would result in increased net benefits and a substantial reduction in future road agency costs compared with the maintenance scenario without preventive maintenance.
Correlations between Strains in a Thin Asphalt Pavement Structure and Deflection Basins
Authors: Posribink Thitikorn , Kongkitkul Warat , Youwai Sompote , Jongpradist Pornkasem
Published: July 2015

In rural areas, thin asphalt surface pavement structures have been constructed for low-volume road networks. For this type of road, a light weight deflectometer (LWD) may be useful for evaluating the responses of a pavement structure. Of the responses, the mobilized horizontal tensile strain at the bottom of asphalt pavement indicates the fatigue cracking potential, while the mobilized vertical compressive strain at the top of the base layer indicates the rutting potential. A series of linear elastic analyses was performed on a thin asphalt surface pavement structure. Correlations between the two mobilized strains and deflection basin parameters were found. A model thin asphalt surface pavement structure was constructed in the field. Many sensors were installed for measuring the mobilized stresses and strains during an LWD test. The test results generally were in agreement with the linear elastic analyses. The mobilized strains in the thin asphalt surface pavement structure could be predicted with the correlations with deflection basin parameters obtained from the LWD test.
Design and Construction of Welded Wire Retaining Walls in the Siuslaw and Willamette National Forests
Authors: Bolander Peter
Published: July 2015

Major winter storms occasionally remove portions of the steep mountainous roads within the Siuslaw and Willamette National Forests of western Oregon. On average, at least one flexible welded wire reinforced wall is built a year in these forests to reestablish the failed roadway. This paper summarizes the procedures used for foundation investigation, analysis and design, and construction administration of welded wire reinforced retaining walls in these forests. Since 2005, the U.S. Department of Agriculture Forest Service has designed the walls according to the current AASHTO LRFD Bridge Design Specifications. The two forests follow AASHTO procedures with some modifications. These modifications include a narrower bench width at the toe of the wall, less conservative global stability resistance factors, no performance of settlement analysis, and stricter fill requirements for reinforced walls.
Estimation of Subgrade Resilient Modulus for Fine-Grained Soil from Unconfined Compression Test
Authors: Hossain M. Shabbir , Kim Wan Soo
Published: July 2015

The resilient modulus of subgrade soil is used to design a pavement structure that is adequate for the expected traffic and environmental loading. Both mechanistic and empirical design procedures use this property. The resilient modulus test is a complex test that requires significant resources, including a high level of technical ability on the part of the operator. For smaller or less critical projects with a low volume of traffic where costly and complex resilient modulus testing is not justified, a correlation with other, simpler tests could be used. In this study, a correlation with the results of an unconfined compression (UC) test is explored for estimation of the resilient modulus of fine-grained soils. This paper presents several models with which to estimate the resilient modulus of fine-grained soil from the results of UC tests considering two sample preparation techniques: static and impact compaction. The simplest model considers only unconfined compressive strength to predict the resilient modulus with a fair correlation. The more detailed models also consider the plasticity index, percentage of material passing the Number 200 sieve, and modulus of the stress–strain curve from the UC test. The sample preparation technique had a significant influence on the UC test results.
Use of Finite Difference Numerical Technique to Evaluate Deep Patch Embankment Repair with Geosynthetics
Authors: Perkins Steve , Cuelho Eli , Akin Michelle , Collins Brian
Published: July 2015

Low-volume roads constructed in steep hillside terrain by cut and cast techniques may experience instability in the form of excessive subsidence that leads to large cracks and differential movement along the roadway bench. The technique of deep patch embankment repair with geosynthetics (DPERG) has been employed in the western United States; DPERG generally involves a 1- to 2-m-deep excavation that is backfilled with compacted granular soils and one or more layers of geosynthetic reinforcement. The design goal of a DPERG is not necessarily to eliminate future slope movement but to confine potential failure surfaces to a region of the slope well below the roadway bench and extending out to the slope face such that a failure surface does not extend up onto the roadway bench. This design results in movement along the roadway bench that is more uniform and less disruptive to traffic. This paper describes the results of a study to evaluate the DPERG technique by analytical methods supported by field observations for the purpose of determining the required depth of the DPERG and the optimum layer spacing of the reinforcement. The study showed that for a given slope geometry and set of soil properties that had led to failure in an unreinforced slope, there were several combinations of DPERG depth and number of reinforcement layers that satisfied the design goal. The study showed that more tightly spaced reinforcement layers were beneficial and that for widely spaced layers, the design goal of a DPERG could not be met, even for a thick DPERG depth.
Design Considerations for Deep Patch Embankment Repair with Geosynthetics
Authors: Collins Brian M.
Published: July 2015

Deep patch embankment repair with geosynthetics (DPERG) is a cost-effective and sustainable method of mitigating roadway embankment damage associated with shallow slumping of the outside shoulder. DPERG is a shallow embankment repair that consists of subexcavating 3 to 6 ft (1 to 2 m) and backfilling with granular material and layers of geosynthetic reinforcement that are vertically spaced 6 to 24 in. (150 to 600 mm). DPERG is constructed either half width or full width, depending on the extent of roadway distress. Use of the deep patch on federally owned roads in the Pacific Northwest dates back to the 1980s. Recent research has improved understanding of soil–geosynthetic interaction, and this knowledge has led to improved DPERG performance and a reduction in DPERG costs. This paper summarizes design and construction recommendations gained from this recent research and experiences with hundreds of DPERGs constructed on Western Federal Lands Highway Division projects in the Pacific Northwest.
Critical Pavement Response Analysis of Low-Volume Pavements considering Nonlinear Behavior of Materials
Authors: Gupta Ankit , Kumar Praveen , Rastogi Rajat
Published: July 2015

An empirical approach is used to design low-volume pavements in many countries, including India. These types of pavements are made up mainly of an unbound granular material layer over a subgrade with a thin asphalt surface. Accurate modeling of the granular material is essential to better correlate the identified mechanistic responses with pavement performance. It is known that unbound materials are nonlinear and have a stress-dependent resilient modulus. Therefore, the stress dependency of unbound materials should be considered to accurately estimate true pavement responses. Suitable codes written in finite element (FE) analysis software were used to model the nonlinearity of unbound granular layers. A three-dimensional FE was developed and analyzed. It was observed that the pavement responses obtained from the three-dimensional FE analysis carried out for typical low-volume pavements, with the nonlinear characteristics of unbound pavement materials taken into account, differed by 34% to 44% from those obtained with linear analysis.
Development of Phenomenological Top-Down Cracking Initiation Model for Mechanistic–Empirical Pavement Design
Authors: Wen Haifang , Bhusal Sushanta
Published: July 2015

The phenomenon of top-down cracking in asphalt pavements has drawn increased attention in recent years, yet the asphalt pavement field still lacks an effective top-down crack initiation model. Many factors contribute to the initiation and propagation of top-down cracking. This study developed a phenomenological top-down crack initiation model for mechanistic–empirical pavement design. Pavements at FHWA's accelerated loading facility were used to develop a top-down crack initiation model based on the failure strain of asphalt mixtures, as obtained from indirect tensile testing. It was found that the current Mechanistic– Empirical Pavement Design Guide top-down cracking model failed to predict top-down cracking in the wheelpath in the field accurately, whereas the proposed failure strain–based top-down cracking model was effective in predicting top-down cracking in the field. In addition, the Level 2 prediction of failure strain is developed here; it is based on binder failure shear strain, air void content, asphalt content, and percentage of aggregate passing U.S. Number 4 and Number 200 sieves. Further studies are needed to validate this new top-down cracking model and to develop an effective crack propagation model.
Pavement Life–Extending Potential of Geosynthetic-Reinforced Chip Seal with High-Reflectivity Aggregates
Authors: Mallick Rajib B. , Li Hui , Harvey John , Myers Ray , Veeraragavan A. , Reck Nicholas
Published: July 2015

High temperatures in asphalt pavements lead to rutting and age-related cracking. Although beneficial for reducing distresses, thicker layers are not generally used in low-volume roads because of cost restrictions. This paper presents an alternative approach in which a geosynthetic-reinforced chip seal layer with high-reflectivity aggregates is used to reduce the temperature in asphalt pavements and therefore reduce the potential of rutting and the rate of aging. If the absorption of the surface of the pavement is lowered and the conductivity of the layers is reduced, then less heat will penetrate through the depth of the pavement, and a lower pavement temperature will result. The absorption at the surface can be reduced through the use of a surface layer with greater reflectivity, and the conductivity can be reduced with the help of a layer of a material that has very low conductivity. Therefore, a composite pavement system can be used for low-volume, asphalt-surfaced roads; the system would incorporate an insulation layer and a high-reflectivity surface layer. The insulating layer will also effectively protect the surface from air and therefore significantly reduce the oxidation exposure and aging of the asphalt binder and the resultant stiffening of the asphalt mix. Analyses of modeling or simulation data and field data from a test section demonstrated a significant reduction in temperature throughout the depth of a pavement and an extension of life by three to four times.
Route from Research into Practice
Authors: Leta Nkululeko , Geddes Robert
Published: July 2015

The Africa Community Access Programme (AFCAP) is a research program in the rural transport sector in Africa. AFCAP supports sharing of knowledge between participating countries to enhance the uptake of appropriate, proven, and fit-for-purpose solutions for rural access. The AFCAP theory of change is based on a virtuous cycle of research that demonstrates best practices and leads to uptake of research findings. Uptake of research outcomes includes capacity development for undertaking further research. Under AFCAP, an efficient route from research into practice has been provided. The demonstration of innovative standards for low-volume roads (LVRs) has been an important step in achieving wider acceptance of those standards. It has been necessary to convince not only practitioners and road agencies but also political decision makers and community representatives. In general, the acceptance levels have been high, which has increased demand for the sealing of LVRs. The reduced construction costs of LVRs that result from a more optimal design approach will allow governments and road agencies to meet the demand more effectively. The sustainability of AFCAP achievements depends on building local research capacity in African countries. AFCAP has created an awareness of the value of research and has provided some of the tools needed by governments to establish their own research programs. The recruitment and retention of suitably qualified and experienced researchers will remain a considerable challenge for the foreseeable future and will require long-term support. However, now that the benefits of research are more apparent and a route from research into practice has been defined, there is a strong determination in African countries to succeed.
Permeable Wearing Courses from Recycling Reclaimed Asphalt Pavement for Low-Volume Roads
Authors: Praticò Filippo Giammaria , Vaiana Rosolino , Iuele Teresa
Published: July 2015

The recycling of reclaimed asphalt pavement (RAP) in hot-mix asphalt (HMA) is an important opportunity in regard to transportation infrastructure construction and maintenance because it helps to achieve more sustainable road transport systems (reduction of waste production and reduction of resource consumption). In particular, totally recycled HMAs can be a good alternative for road paving even if performance can be an issue. As is well known, the type of low-volume road pavement (gravel, coarse rocky soil, crushed aggregate, cobblestone, concrete block, or some type of bituminous seal coat or asphalt pavement) depends on traffic volume, native in-place soils, and the need to control surface and depth erosion. The objectives and scope of this research were confined to the formalization of strategies and technical procedures for recycling RAP from porous asphalt concretes to obtain permeable wearing courses for low-volume roads. Different solutions were investigated. High percentages of RAP were used in the recycling process, and traditional and advanced tests on RAP and recycled mixes were carried out. RAP variability was examined, and a method for facing its consequences was proposed. Mechanical performance was adequate. Recycling porous European mixes could be a proper way to achieve environmental sustainability in pavement construction, as the functional performance results are very promising and encouraging. Practical applications and perspectives in rehabilitation, maintenance, and research are outlined.