bluuebunny/crossref_metadata_2025 huggingface dataset:
Full Depth Reclamation of Asphalt Pavements Using Coal Combustion Byproducts
Authors: Butalia Tarunjit S. , Kirch James
Published: July 2011

The objective of this study was to demonstrate the use of Class F coal fly ash in combination with lime or lime kiln dust (LKD) in full depth reclamation (FDR) of failing asphalt pavements. Full-scale test sections (about 4 miles in length) of two structurally deficient asphalt pavements were reclaimed using Class F fly ash in combination with lime and LKD. In addition, control sections were constructed using cement, cement and emulsion, LKD and emulsion, and simple recompaction. The service performance and structural behavior of the reclaimed pavement test sections were monitored to determine how the fly ash sections compared with other admixtures. Service performance and structural behavior were determined through a program of falling weight deflectometer (FWD) tests and embedded sensors installed at the time of construction. Monitoring results of the FWD tests conducted up to 3 yr after reclamation show that the cement, fly ash and LKD, and fly ash and lime sections exhibited resilient modulus values comparable to soil cement. The cement treatment resulted in a significant increase in resilient modulus within three weeks of the end of construction but beyond this curing time stiffness increase was slow. Tests on fly ash and LKD and fly ash and lime test sections indicated a slower short-term increase in stiffness, but the two fly ash stabilized sections 3 yr after construction exhibit average resilient modulus values of 400–1,300 ksi.
Pharmacogenomics in the Assessment of Therapeutic Risks versus Benefits: Inside the United States Food and Drug Administration
Authors: Zineh Issam , Pacanowski Michael A.
Published: July 2011

Pharmacogenomics is the study of how genetic variations influence responses to drugs, diagnostics, or biologic agents. The field of pharmacogenomics has significant potential to enhance drug development and aid in making regulatory decisions. The United States Food and Drug Administration (FDA) has supported pharmacogenomics for nearly a decade by providing regulatory advice and reviewing applications, with the intent of discovering and applying genetic determinants of treatment effects. The FDA will continue to develop policies and processes centered on genomics and individualized therapeutics to guide rational drug development. It will also continue to inform the public of clinically relevant pharmacogenomic issues through various mechanisms of communication, such as drug labeling. In this review, we provide a perspective on several pharmacogenomic activities at the FDA. In addition, we attempt to clarify what we believe are several misperceptions regarding the FDA's pharmacogenomic initiatives. We hope this perspective provides a window into some ways in which the FDA is enabling individualized therapeutics through its mission‐critical activities.
The Retrospective Cohort of Extended‐Infusion Piperacillin‐Tazobactam (RECEIPT) Study: A Multicenter Study
Authors: Yost Raymond J. , Cappelletty Diane M. ,   RECEIPT Study Group
Published: July 2011

Study Objective. To compare the effectiveness of extended‐infusion piperacillin‐tazobactam with that of similar‐spectrum, nonextended‐infusion β‐lactam antibiotics in the treatment of gram‐negative infections.

Design. Multicenter, retrospective medical record review.

Setting. Fourteen hospitals throughout the United States.

Patients. A total of 359 adults treated for gram‐negative infections between January 1, 2007, and February 28, 2010, with either 4‐hour extended‐infusion piperacillin‐tazobactam (186 patients) or nonextended‐infusion comparator antibiotics (173 patients), which consisted of cefepime, ceftazidime, imipenem‐cilastatin, meropenem, doripenem, or piperacillin‐tazobactam.

Measurements and Main Results. Deidentified data were collected on demographics, renal function, Acute Physiology and Chronic Health Evaluation II score, chronic health conditions, source of infection and type of organism, intensive care unit (ICU) length of stay, total length of stay, type and duration of antimicrobial therapy, and in‐hospital mortality. The primary outcome was mortality rate of the patients receiving extended‐infusion piperacillin‐tazobactam versus those receiving nonextended‐infusion comparator antibiotics. Secondary outcomes were hospital length of stay, ICU length of stay, and total duration of antibiotic therapy. Baseline characteristics were similar between groups, except a significantly lower proportion of patients in the extended‐infusion group were treated with a concomitant intravenous aminoglycoside (5.9% vs 16.2%, p<0.01), were infected with Pseudomonas species (22.6% vs 39.9%, p<0.01), or had positive respiratory cultures (30.7% vs 43.4%, p=0.01). Antibiotic duration, hospital length of stay, and ICU length of stay were similar between groups. In‐hospital mortality was significantly decreased in the extended‐infusion piperacillin‐tazobactam group versus those receiving comparator antibiotics (9.7% vs 17.9%, p=0.02). Multivariate analysis confirmed that extended‐infusion piperacillin‐tazobactam prolonged survival by 2.77 days (p<0.01) and reduced the risk of mortality (odds ratio 0.43, p=0.05).

Conclusion. Pharmacodynamic dosing using extended‐infusion piperacillin‐tazobactam demonstrated favorable outcomes, including mortality, when compared with nonextended‐infusion, similar‐spectrum β‐lactams in the treatment of patients with documented gram‐negative infections. Prospective, randomized trials are needed to further corroborate these findings.
An Opinion Paper Outlining Recommendations for Training, Credentialing, and Documenting and Justifying Critical Care Pharmacy Services
Authors: Dager William , Bolesta Scott , Brophy Gretchen , Dell Kamila , Gerlach Anthony , Kristeller Judith , Micek Scott , Hess Mary , Bentley Michael , Juang Paul , MacLaren Robert , Kane‐Gill Sandra , Haase Krystal , Mann Henry , Miller Colby , Pepe Diane , Southwood Robin , Weant Kyle , Rebuck Jill , Wood Christopher
Published: July 2011

In 2000, the Society of Critical Care Medicine (SCCM) and the American College of Clinical Pharmacy (ACCP) published a position paper that defined critical care pharmacy services as fundamental, desirable, and optimal. A task force was developed that included individuals who are members of the ACCP Critical Care Practice and Research Network, the SCCM clinical pharmacy and pharmacology section, and the American Society of Health‐System Pharmacists to develop an opinion paper with three primary objectives: to provide recommendations for the level of preparation and training of pharmacists to practice in critical care, to develop recommendations for the credentialing of pharmacists providing critical care services, and to develop mechanisms for documenting and justifying intensive care unit (ICU) pharmacy services. Each objective was addressed to accommodate the levels of services defined as fundamental, desirable, or optimal, and are targeted at all pharmacists providing or wanting to provide pharmacy services to critically ill patients. The training and preparing of the pharmacist caring for critically ill patients is discussed in the context of the knowledge and skills required to provide pharmacy services in the ICU. Credentialing of the critical care pharmacist and the documentation of services take into account the various scopes of practice, and recommendations are based on current and idealistic mechanisms. A detailed outline is provided for the process of services justification. This paper provides a foundation that is focused on delivering direct and proactive patient care services, particularly at the desirable and optimal levels, with the ultimate goal of enhancing the level of pharmacy services provided to the care of critically ill patients. This commentary should be of interest to numerous stakeholders including pharmacists, other pharmacy department staff, other ICU health care professionals, hospital and academic administrators, accrediting agencies, government officials, and payers. The task force encourages the profession of pharmacy in general to incorporate key recommendations provided in this document with respect to specialized training, credentialing, and service justification.
Design guidelines for FRP reinforced concrete structures
Authors: Pilakoutas Kypros , Guadagnini Maurizio , Neocleous Kyriacos , Matthys Stijn
Published: July 2011

This paper presents an outline of the approach proposed by fib task group 9.3 for the next generation of design guidelines for fibre-reinforced polymer (FRP) reinforced concrete structures. The approach covers a range of FRP-related topics, including material properties, durability, design philosophy, the limit states of bending, shear, cracking and deflection, and bond.
Structural performances of PBO FRCM-strengthened RC beams
Authors: Ombres Luciano
Published: July 2011

Innovative composites made by fibre meshes (glass, carbon or polypara-phenylene-benzo-bisthiazole (PBO) fibre meshes) embedded into an inorganic stabilised cementitious matrix called fibre-reinforced cementitious mortars (FRCM) represent a very effective solution for strengthening reinforced concrete beams. The FRCM strengthening system can be considered alternative to the well-known fibre-reinforced polymers (FRP) system made by unidirectional fibre sheets embedded into organic resins; the FRCM system, in fact, allows the reduction or elimination of some disadvantages related to the use of organic resin such as lack of fire resistance, degradation under ultraviolet light and low compatibility with the concrete substrate, without compromising the performance of strengthened members. Owing to the large slip at the fibre–cementitious matrix interface, a more ductile behaviour and different failure modes were experimentally observed in FRCM strengthened beams with respect to those strengthened with fibre-reinforced polymers. These structural aspects are analysed and discussed in the paper by means of the results of an experimental investigation carried out on reinforced concrete beams flexurally strengthened with PBO-FRCM. Obtained results indicate an improvement of the flexural capacity of PBO-FRCM-strengthened beams, the change of the failure modes with the increase of PBO reinforcement ratio and, in the presence of debonding, the occurrence of a gradual failure.
Midwest U.S. landscape change to 2020 driven by biofuel mandates
Authors: Mehaffey Megan , Smith Elizabeth , Van Remortel Rick
Published: July 2011

Meeting future biofuel targets set by the 2007 Energy Independence and Security Act (EISA) will require a substantial increase in production of corn. The Midwest, which has the highest overall crop production capacity, is likely to bear the brunt of the biofuel‐driven changes. In this paper, we set forth a method for developing a possible future landscape and evaluate changes in practices and production between base year (BY) 2001 and biofuel target (BT) 2020. In our BT 2020 Midwest landscape, a total of 25 million acres (1 acre = 0.40 ha) of farmland was converted from rotational cropping to continuous corn. Several states across the Midwest had watersheds where continuous corn planting increased by more than 50%. The output from the Center for Agriculture and Rural Development (CARD) econometric model predicted that corn grain production would double. In our study we were able to get within 2% of this expected corn production. The greatest increases in corn production were in the Corn Belt as a result of conversion to continuous corn planting. In addition to changes to cropping practices as a result of biofuel initiatives we also found that urban growth would result in a loss of over 7 million acres of productive farmland by 2020. We demonstrate a method which successfully combines economic model output with gridded land cover data to create a spatially explicit detailed classification of the landscape across the Midwest. Understanding where changes are likely to take place on the landscape will enable the evaluation of trade‐offs between economic benefits and ecosystem services allowing proactive conservation and sustainable production for human well‐being into the future.
Use of land facets to design linkages for climate change
Authors: Brost Brian M. , Beier Paul
Published: July 2011

Least‐cost modeling for focal species is the most widely used method for designing conservation corridors and linkages. However, these linkages have been based on current species' distributions and land cover, both of which will change with large‐scale climate change. One method to develop corridors that facilitate species' shifting distributions is to incorporate climate models into their design. But this approach is enormously complex and prone to error propagation. It also produces outputs at a grain size (km2) coarser than the grain at which conservation decisions are made. One way to avoid these problems is to design linkages for the continuity and interspersion of land facets, or recurring landscape units of relatively uniform topography and soils. This coarse‐filter approach aims to conserve the arenas of biological activity rather than the temporary occupants of those arenas. In this paper, we demonstrate how land facets can be defined in a rule‐based and adaptable way, and how they can be used for linkage design in the face of climate change. We used fuzzy c‐means cluster analysis to define land facets with respect to four topographic variables (elevation, slope angle, solar insolation, and topographic position), and least‐cost analysis to design linkages that include one corridor per land facet. To demonstrate the flexibility of our procedures, we designed linkages using land facets in three topographically diverse landscapes in Arizona, USA. Our procedures can use other variables, including soil variables, to define land facets. We advocate using land facets to complement, rather than replace, existing focal species approaches to linkage design. This approach can be used even in regions lacking land cover maps and is not affected by the bias and patchiness common in species occurrence data.
Computational Fluid Dynamics Characterization of a Bioreactor Mixing Device for the Animal Cell Culture
Authors: Gelbgras Valérie Gisèle , Wylock Christophe E , Drugmand Jean-Christophe , Haut Benoît
Published: July 2011

During a cell culture in a bioreactor, the cells are exposed to the shear stresses mainly generated in the culture medium by the mixing device. Beyond a critical shear stress, this exposition induces cell damages. Therefore, the limitation of the shear stress is an important criterion for the design of bioreactors. An accurate modeling of the flow and the induced shear stresses in the medium is a tool to achieve an effective design of a bioreactor. In this work, a new design of a mixing device is considered. The aims of this work are to develop a methodology to study the flow and the induced shear stresses in the device, to study and to model the relation between the flow, the induced shear stresses and the cell viability, to use the developed model as an optimization tool, and to study the design of the bioreactor mixing device and its scale-up. In a first step, the flow and the induced shear stresses in the device are simulated by Computational Fluid Dynamics. In a second step, the model of the influence of the flow and the induced shear stresses on the cell viability is established by a comparison between the computed flow and the induced shear stresses and experimental measurements of cellular viabilities for different impeller rotation speeds. Finally, the influence of another design of the mixing device on the cell viability is studied.
School development planning in Serbia: How teachers evaluate it
Authors: Stankovic Dejan
Published: July 2011

School development planning is an instrument of school internal development.
It has been present in Serbian schools since 2002, but until today there have
not been enough data regarding the way development planning takes place and
what its effects are. The main question in this research is how the teachers
directly involved in the process itself evaluate development planning in
their schools. The sample consisted of 291 teachers from 51 primary schools
in Serbia. They replied in written form to the open-ended questions regarding
their opinion about the positive and the negative sides of school development
planning. Data processing included creating categories of teacher answers and
calculating the relative presence of answers by categories. Teachers
estimated that the following were the positive sides of development planning:
strengthening cooperation and team work, introducing planning practice,
school development, increased participation, successful project realization
and acquisition of new knowledge and advanced training. Teachers most often
had no objections to development planning, and when they did, these referred
to the following: insufficient support to the development team, resistance
and lack of interest of their colleagues, demands of planning, problems with
the functioning of the development team and poor plan realization. The
results point out to the conclusion that school development planning is
predominantly positively evaluated and at the same time provide the
foundation for arriving at practical ideas regarding the future direction of
the policies in the field of internal school development.
Assessing oral presentations at the B2 level: Quantitative and qualitative analysis
Authors: Radic-Bojanic Biljana , Lazovic Vesna , Topalov Jagoda
Published: July 2011

The Common European Framework of Reference (CEFR) describes the B2 level as
having limited operational proficiency, where speakers have an adequate
response to situations normally encountered. In the spoken domain a B2 user
is said to interact with a degree of fluency and spontaneity, to produce
clear, detailed text on a wide range of subjects and to explain a viewpoint
on a topical issue giving the advantages and disadvantages of various
options. Besides that, a B2 user should be able to spontaneously depart from
the previously prepared presentation material and to interact with an
audience to develop interesting parts of his/her presentation. This paper,
accordingly, focuses on oral presentations of university students who were
put at the B2 level of CEFR. The sample comprises students who study English
as their major and students of other departments who take classes of English
as a foreign language. The primary method of research is observation done by
the teacher while students present previously chosen and prepared topics. The
aim of the research is to determine whether the students from the sample,
representative of their population, fit into the description and criteria of
the B2 level.
Ubiquitous Mobility with Mobile Phones: A Cultural Ecology for Mobile Learning
Authors: Cook John , Pachler Norbert , Bachmair Ben
Published: July 2011

This article argues that mobile phones should be viewed as new cultural resources that operate within an individualized, mobile and convergent mass communication; such a recognition facilitates the options for a cultural ecology. A particular challenge here is to find adequate curricular functions in school where the inclusion of these new cultural resources can and should be introduced. The authors expand their argument, first, by discussing mobile devices as cultural resources theoretically from the perspective of their position within what they call a triangular-oriented mobile complex; second, by means of this triangular analysis of structures, agency and cultural practices the mobile complex is investigated with the purpose of positioning the school in relation to this complex; third, they present the notion of user-generated contexts as a means of integrating meaning-making from the world outside of schools into the school and its curriculum. User-generated context is conceived by the authors in a way in which users of mobile digital devices are being ‘afforded’ synergies of knowledge distributed across people, communities, locations, time (life course), social contexts and sites of practice (such as socio-cultural milieus) and structures. In order to concretize this notion of context they give a brief example. The article then goes on to draw on a case study of a school project that examines mobile devices and associated media within school mathematics. This analysis leads the authors to propose some guidelines for mobile learning. They conclude by noting some significant methodological challenges for their future research around the mobile complex and user-generated contexts.
The (Im)Materiality of Educational Space: Interactions between Material, Connected and Textual Dimensions of Networked Technology Use in Schools
Authors: Burnett Cathy
Published: July 2011

In contributing to understanding about the barriers and opportunities associated with new technologies in educational settings, this article explores dimensions of the educational spaces associated with using networked technologies in contemporary classrooms. After considering how educational spaces may be ‘produced’ (to use Lefebvre's term), it draws on narratives of classroom practice to explore three dimensions of educational space – material, connected and textual – and considers the implications that these, and the relationships between them, may have for the use of networked technologies in education. It concludes by setting an agenda for future research, arguing that more extensive empirical work is needed to explore how these dimensions intersect and the implications this has for pedagogy. The need for such research is seen as particularly pressing given increased calls for transformative pedagogies which demand new ways of interacting within and between educational spaces.
Teachers Teaching in the New Mediascape: Digital Immigrants or ‘Natural Born Cyborgs’?
Authors: Adams Catherine A. , Pente Patti
Published: July 2011

Schooled in an earlier time, educators are laboring to find meaningful purchase in new media environments, unable to match the fluency and sophistication of their ‘digital native’ students. Yet is Marc Prensky's portrayal of teachers as ‘digital immigrants’ really an accurate rendering of the today's situation? Drawing on phenomenological and posthuman literature, the authors reconsider teachers' everyday involvements with technologies, and explore new ways of conceptualizing teachers and students in today's mediatic situation. They suggest that teachers and students alike are more aptly – and less divisively – visualized as digital migrants or nomadic cyborgs navigating and acclimatizing to a restless twenty-first-century educational scene.
Digital (A)Literacy
Authors: Rose Phil
Published: July 2011

This article investigates the tendency of those who explore the topic of ‘electronic literacies’ to downplay the fundamental nature and importance of the perceptual habits associated with print literacy, and highlights the opposite tendency of reading and writing specialists to decontextualize the acquisition of these fundamental skills from the character of the culture at large. Making the case for a perspective located somewhere between these two positions, which attends to cognitive and neurological distinctions between our media interfaces, the author surveys a number of purported social trends in the United States. Among these are the increased rates of television viewing; the inadequacy of writing practice and instruction in American educational institutions; and the migration of writing, typing, and reading to the computer screen. In relation to these trends, he considers our prospects for the cultivation of a type of ‘secondary literacy’, in order that we might attain a kind of equilibrium within the cultural conditions that Walter Ong describes as ‘secondary orality’ – a phenomenon inherent in our general reliance on the most common electronic communication forms, which, in the communication contexts that they create, predominantly employ the spoken word and moving imagery.
Changes of pharyngeal airway size and hyoid bone position following orthodontic treatment of Class I bimaxillary protrusion
Authors: Wang Qingzhu , Jia Peizeng , Anderson Nina K. , Wang Lin , Lin Jiuxiang
Published: July 2011

Objectives:

To test the hypothesis that the sagittal position of the anterior teeth has no effect on pharyngeal airway dimension or hyoid bone position and to investigate the influence of orthodontic retraction of the anterior teeth on each section of pharynx and hyoid position.

Materials and Methods:

Forty-four Class I bimaxillary protrusion adults, treated with preadjusted appliances and maximum anchorage after extraction of four premolars, were divided into two groups according to their vertical craniofacial skeletal patterns. Pretreatment and posttreatment variables were compared using paired t-test, and the relationship between pharyngeal airway size and dentofacial variables was analyzed using Pearson correlation coefficient. The changes of pharyngeal airway size and hyoid position after treatment were compared between two groups using independent t-test.

Results:

Upon retraction of the incisors, the upper and lower lips were retracted by 2.60 mm and 3.87 mm, respectively. The tip of upper incisor was retracted by 6.84 mm and lower incisor retracted by 4.95 mm. There was significant decrease in SPP-SPPW, U-MPW, TB-TPPW, V-LPW, VAL, C3H, and SH (P < .05). No statistically significant different changes were observed in the dentofacial structures, pharyngeal airway, and hyoid position between the two groups after the treatment. There was a significant correlation between the retraction distance of lower incisor and the airway behind the soft palate, uvula, and tongue.

Conclusions:

The pharyngeal airway size became narrower after the treatment. Extraction of four premolars with retraction of incisors did affect velopharyngeal, glossopharyngeal, hypopharyngeal, and hyoid position in bimaxillary protrusive adult patients.
Shear bond strength of brackets to demineralize enamel after different pretreatment methods
Authors: Attin Rengin , Stawarczyk Bogna , Keçik Defne , Knösel Michael , Wiechmann Dirk , Attin Thomas
Published: July 2011

Objective:

To compare the influence of demineralized and variously pretreated demineralized enamel on the shear bond strength of orthodontic brackets.

Materials and Methods:

Sixty bovine enamel specimens were allocated to five groups (n  =  12). Specimens of group 1 were not demineralized and were not pretreated, but served as controls. The other specimens were demineralized to form artificial carious lesions. Samples from group 2 were only demineralized and were kept untreated in artificial saliva. The other samples were pretreated with highly concentrated fluoride preparations (group 3: Elmex Gelee, 1.23% F; group 4: Clinpro White Varnish, 2.23% F) or with an infiltrating resin (group 5: Icon). After respective pretreatments, brackets were adhesively fixed on all specimens with an adhesive system after etching with 35% phosphoric acid and application of a primer and bracket resin cement (Transbond XT). Bracket shear bond strength was evaluated with a universal testing machine. Statistical analysis was performed by one-way analysis of variance followed by a post-hoc Scheffé test.

Results:

Shear bond strength in control group 1 was statistically significantly greater compared with that in all other groups. Application of the infiltrating resin Icon (group 5) as pretreatment resulted in statistically significantly greater bond strength as compared with pretreatments with fluoride compounds (groups 3 and 4) and treatment provided without pretreatment (group 2). Groups 2, 3, and 4 did not significantly differ from each other.

Conclusion:

Pretreatment with the infiltrating resin is a beneficial approach to increasing the shear bond strength of brackets to demineralized enamel.
Yolk Sac Tumor of the Thyroid Gland: A Case Report
Authors: Furtado Larissa V. , Leventaki Vasiliki , Layfield Lester J. , Lowichik Amy , Muntz Harlan R. , Pysher Theodore J.
Published: July 2011

Extragonadal yolk sac tumors are uncommon and usually seen in sacrococcygeal, mediastinal, intracranial, and retroperitoneal sites. Yolk sac tumors of the head and neck region are rare, and the few reported cases have arisen in neonates or infants in conjunction with a teratoma or other germ cell tumor subtypes. We report a unique case of a pure yolk sac tumor presenting as a primary lesion in the right thyroid lobe of a 10-year-old girl. The diagnosis was suspected after fine-needle aspiration, and extensive sampling of the thyroidectomy specimen revealed no teratoma or other germ cell tumor. Serum α-fetoprotein levels were markedly elevated 6 days after excision, and imaging disclosed numerous bilateral pulmonary nodules suggestive of metastatic disease but did not reveal a mediastinal mass. The tumor has shown a favorable response to bleomycin, etoposide, and cisplatin chemotherapy. To the best of our knowledge, this is the 1st description of a primary pure yolk sac tumor of the thyroid.
Tubocutaneous Fistula in a Premature Infant
Authors: Waters Brenda L.
Published: July 2011

Fistulous tracts between the uterus and skin were more common in the preantibiotic era and most often occurred after pelvic surgery. Tubocutaneous fistulas constituted a subset of this form of operative complication. With the improvement of operative techniques and use of antibiotics, the incidence of these fistulas is greatly reduced. In cases reported since 1963, the youngest patient to develop a tubocutaneous fistula was 15 years old. Reported here is an infant delivered at 25 weeks’ gestation, who developed necrotizing enterocolitis requiring 2 surgical interventions. At the time of insertion of a tunneled central venous catheter, the surgeon noted a mass in the right lower quadrant, which he excised. A noninflamed tubocutaneous fistula was identified pathologically with only the distal portion of the tube present. The child's history is similar to other reports in that she had previous operations and had developed significant fibrous abdominal adhesions. Her history is unique in that she is the youngest reported case and hers is the 1st report of this complication following surgery for necrotizing enterocolitis.
Evaluation of Erosion Prediction Models for Forest Roads
Authors: Skaugset Arne E. , Surfleet Christopher G. , Meadows Matthew W. , Amann Joseph
Published: July 2011

Forest roads can be a source of accelerated erosion, which can be detrimental to aquatic habitat, fish, and other aquatic biota. Erosion models are increasingly used to quantify sediment production from forest roads. This project evaluated the efficacy of these models to predict erosion from forest roads. Sediment production was measured from 44 road segments in the humid, temperate rain forests of Oregon and California. Sediment production from these road segments was estimated with four contemporary erosion models: the Washington Road Surface Erosion Model (WARSEM); Sediment Model 2 (SEDMODL2); WEPP:Road, an interface for the Water Erosion Prediction Project Model; and the revised universal soil loss equation (RUSLE). The erosion models consistently overestimated the amount of sediment produced by the road segments by 2 to 8 times. The results were highly variable, and there were considerable differences in erosion estimated by the four models, even for the same road segment. Further, the erosion models could not consistently identify the road segments that were the top sediment producers. It is hypothesized that the regionalized parameters used as inputs for the models do not adequately characterize the hydrology of the individual road segments. In the humid, temperate rain forests of the Pacific Northwest, surface erosion from forest roads is best predicted by the amount of runoff from the road during storms. Thus, research that will better quantify the hydrology of forest roads will provide better information to predict surface erosion from forest roads.
Correspondence of Horizontal and Vertical Alignment with Safe Driving Conditions on Low-Volume Roads
Authors: ŽIlionienė D. , Vorobjovas V.
Published: July 2011

Since 1998, when the Gravel Roads Paving Program was started on the regional roads of the Republic of Lithuania, the length of gravel roads has shortened by 13.4% after reconstruction. It was discovered, however, that after reconstruction, 4.7% of gravel road sections became potentially dangerous. A disadvantage that was noted during implementation of the Gravel Roads Paving Program was a slightly changed or entirely unchanged horizontal alignment of the roads. In addition, after a gravel road is paved, the speed limit increases from 70 km/h to 90 km/h, as is allowed by traffic regulations, although the design speed of regional roads is 70 km/h and the road alignment was planned for that design speed. The horizontal alignment of 30 regional roads was investigated to assess the compatibility of horizontal alignment elements and their correspondence with traffic safety and to study the sight distance in vertical alignments. It was determined that compatibility of the horizontal alignment elements of regional roads was sufficient, but the estimated flow speed on these elements was 10 to 20 km/h higher than the design speed. Analysis of the sight distance, the stopping sight distance, and the passing sight distance in the vertical alignment of roads showed that in 90% of the cases, the sight distance was shorter than the stopping sight distance on a tangent.
Speed Distribution on Low-Volume Roads in Italy
Authors: Praticò Filippo Giammaria , Giunta Marinella
Published: July 2011

Low-volume roads can be defined as facilities outside built-up areas with a traffic volume of less than 400 annual average daily traffic. Although of lower use because of their location, low-volume roads play an important social and economic role and sometimes represent a large part of the regional and national road network. Regarding their geometric and structural features, they usually have not changed since they were built, and improvement according to current design standards can be uneconomical because the needs are great and the funds insufficient. To this purpose, less restrictive design criteria can be used. Design practices for low-volume roads should be as well addressed as those for high-volume roads. The current speed on low-volume roads appears to be a crucial parameter in reconstruction or rehabilitation design. The present study is focused on analysis of the speed distribution on low-volume roads in comparison with the design speed in order to establish fitting design criteria in rehabilitation. An experimental investigation was carried out on a low-volume road in the province of Reggio Calabria, in southern Italy. The speed distribution was assessed for different conditions of horizontal and vertical alignment in order to understand and possibly quantify the influence of road geometric features. Results demonstrated that under specific conditions, the speed distribution can be predicted on the basis of geometric features. Further, on the basis of operating speed, it was possible to derive information that could be relevant in terms of rehabilitation design criteria.
Planning, Design, and Construction of Low-Cost Roads and Bridge Accessibility
Authors: Greenstein Jacob
Published: July 2011

The goal of donors in poor countries and in countries after conflicts and natural disasters has been to restore safe road accessibility, create employment, and build the local capacity of road infrastructure management. The paper presents the engineering considerations and the socioeconomic outcomes of low-cost road and bridge improvement and maintenance projects that have been planned and implemented at various locations around the world. The 2008 Haitian rainy season caused a complete collapse of the transport system, including the Ennery Bridge, as well as major crop destruction. The U.S. Agency for International Development supported the Haitian government to accelerate the restoration of safe accessibility over the Ennery River by building a 60-m two-lane ford in 2 months in 2009. In southern Sudan, demining work along priority roads had to be completed before the implementation of basic engineering activities needed to develop effective road improvement work. Low-volume road projects in Latin America demonstrated that hundreds of community-based microenterprises can produce effective road maintenance services on more than 15,000 km of unpaved roads at an average cost of $700/km/year. In the Central African Republic, the low cost of reconstruction of roads and timber-deck bridges was essential to the provision of affordable accessibility.
Financing Low-Volume Road Improvements
Authors: Clemmons Gregory H. , Saager Victoria
Published: July 2011

Over the past 30 years the population of Washington County, Oregon, has doubled to more than 530,000 residents. With growth limited to the urban area, resources for urban roads mostly kept pace with population growth, but little funding was available for maintenance and improvement of rural local roads. The county has about 250 mi of rural gravel roads in its 1,279-mi inventory. A $50 million investment to pave them all would be challenging to fund and difficult to justify. Creative approaches were needed to fund road improvements. Washington County's Board of Commissioners adopted and backed road maintenance policies, and county voters supported funding initiatives that made possible a variety of creative financing methods to fund low-volume road improvements. This paper discusses how more than 80 low-volume roads that were once gravel were upgraded to a hard surface using financing methods that may be available to other local jurisdictions.
Rapid Response Stimulus Package for Improving Local Roads and Creating Jobs in Armenia
Authors: Ishihara Satoshi , Bennett Christopher , Bakhtamyan Alexander , Ning Jiangbo , Faiz Asif
Published: July 2011

In late 2008, the Republic of Armenia requested World Bank assistance to help mitigate the local impact of the global financial crisis. This paper describes how the Lifeline Road Improvement Project (LRIP) in Armenia was prepared and implemented as a rapid-response stimulus package. The project was prepared in just 6 weeks. This project helped rehabilitate more than 150 km of low-volume rural roads and generated about 15,000 person-months of employment over an 8-month period from May to December 2009. The World Bank's Operational Policy 8.0, Rapid Response to Crises and Emergencies, was applied to the design and implementation of this project. This operational policy is invoked when major adverse economic and social impacts resulting from natural disasters or crises caused by humans occur and triggers the use of a set of streamlined procedures for rapid project preparation and implementation. The lessons learned from the design and implementation of this stimulus package offer useful guidance for preparing rapid-response infrastructure programs and projects under similar conditions and circumstances in other countries.
Performance Criterion for Thin-Surface Low-Volume Roads
Authors: Sahoo Umesh Chandra , Reddy K. Sudhakar
Published: July 2011

About 80% of the total road network in India is under the rural roads category, and these roads usually carry low traffic volumes. These roads are generally built as granular pavements (with or without a thin bituminous surface) and are designed according to Indian Roads Congress guidelines for the design of rural roads, which do not include mechanistic principles. Considering the size of the rural road network in the country, rationalization of the design approach can result in the optimal use of resources. Gathering experience on the performance of pavements under different climatic and traffic conditions is crucial for developing rational pavement design approaches. Because granular material forms the main structural layers of these pavements, accurate modeling of the granular layers is essential for analysis of low-volume (rural) road pavements. Under application of a load, granular material behaves nonlinearly and shows stress hardening characteristics (i.e., the resilient modulus is stress dependent). In this study, an attempt has been made to develop a rational performance criterion for thin-surface low-volume roads by use of performance data collected from selected road sections in the eastern part of India and consideration of the nonlinearity of the granular layers in the mechanistic analysis of the pavements.
Storm Damage Risk Reduction
Authors: Keller Gordon , Ketcheson Gary
Published: July 2011

The United States and other countries spend millions of dollars annually on storm damage repairs. Most of this work is to repair existing roads and transportation facilities. Large amounts of repair work have been done on the low-volume road network of the U.S. Department of Agriculture Forest Service over the past three decades, particularly in the Pacific Northwest. Agencies cannot afford to build roads to be 100% storm resistant, or stormproof, but they can be made more storm resistant. Measures can be taken to reduce the risk of storm damage from any given event. The objectives of this paper are to identify the assessment process and discuss treatments that can be used to reduce road damage and environmental impacts. Storm damage risk reduction first involves an assessment of any given road, the natural setting, the value of the road, traffic use, and design standards. Because resources are always limited, roads in areas of high risk, in steep terrain, or in areas subject to flooding, and the most important roads, from both the infrastructure and environmental standpoints, should be prioritized for preventative work. Storm damage risk reduction measures include many maintenance, drainage improvement, and structural tasks. Roadway surface drainage structures such as ditches, cross drains, and rolling dips need to be clean, properly armored, and properly spaced to prevent the concentration of water. Drainage-crossing structures such as bridges, fords, and culverts need to have adequate capacity or at least be clear of debris, well armored, scour resistant, and functioning properly. Trash racks can be added. Marginally stable road cuts and fills can be modified and reinforced with vegetation or soil bioengineering treatments. Staying current with road maintenance is critical for proper road function during storms.
Models of Operating Speeds for Low-Volume Roads
Authors: Discetti Paolo , Dell'acqua Gianluca , Lamberti Renato
Published: July 2011

Recent studies have documented a noticeable disparity between the speeds for which roads are designed and the actual operating speeds. An important reason for driving errors on two-lane rural roads is the misjudgment of the real course of the road by road users. Unfavorable visibility conditions are one of the problems of road infrastructure that can be detected on existing low-volume roads. Therefore an operating speed model was developed to calculate the contribution made by sight distance, and to be a useful tool for planners in the study of the safety of existing roads. Seven low-volume roads in the province of Salerno, Italy, were studied. The study identified operating speeds on 84 curves; the relative sight distance, radius, radius of the previous curve, length of the tangent before the curve, curvature change rate, development of the curve, and number of speed changes made during the study were determined for each curve. Because of the different characteristics of the roads analyzed, once the data were collected it was possible to develop two operative speed models. The first was suitable for roads characterized by consecutive curves alternating with small tangents and the second model was mainly intended for roads characterized by a small number of curves that were preceded and followed by long tangents.
Blading Optimization
Authors: Van Zyl Gerrie
Published: July 2011

The first attempt to develop and implement an optimization module to minimize agency costs and vehicle operating costs in the Western Cape, South Africa, was considered unsuccessful. Routines incorporated the current roughness of the road; deterioration as a result of traffic, climate, and materials; and improvement in roughness after the road was bladed and calculated the blading sequence of road sections in a road network. Lessons about both appropriate principles and practical issues learned in the development process highlighted that generalization of gravel road deterioration can lead to incorrect decisions. Although computerized routines are of value, the complexities and variability of maintenance requirements suggest that optimization of grader maintenance is a reiterative process into which local knowledge, all constraints and variables, as well as computer technology must be incorporated. This paper describes a revised practical approach and process for the development of a grader maintenance business plan. The process has been implemented with success by road authorities in southern Africa and will be published as a best practice in the TRH 20 national guideline document, Technical Recommendations for Highways: Structural Design, Construction, and Maintenance of Unsealed Roads.
Condition Performance Models for Network-Level Management of Unpaved Roads
Authors: Chamorro Alondra , Tighe Susan L.
Published: July 2011

Unpaved roads may represent more than 80% of a country's road network. Given the socioeconomic importance of unpaved roads to the well-being and development of rural populations, agencies in charge of their management should maintain them in optimum condition. A good management system should consider the use of effective evaluations of road conditions and reliable condition performance models. Available performance models for unpaved roads estimate the progression of one distress type subject to variations of independent variables affecting their performance over time. These variables commonly require detailed evaluations of road materials, geometric design, and traffic, demanding considerable expense and limiting the application of the models to project-level management. The objective of this study is to develop condition performance models for network-level management of unpaved roads on the basis of probabilistic deterioration trends observed in the field. The scope is to design practical models that are applicable to different climatic conditions and various road types and that can be effectively used by agencies in developing countries. The condition of an unpaved road network in Chile was assessed during three evaluation periods by use of the unpaved condition index methodology. Finally, condition performance curves for gravel and earth roads were developed with Markov chains and Monte Carlo simulation by consideration of a 10-year analysis period and three different climates.