A Novel Homozygous R764H Mutation in CRB1 Causes Autosomal Recessive Retinitis Pigmentosa in a Consanguineous Family

Purpose: Retinitis pigmentosa (RP; MIM 268000) is a hereditary disease characterized by poor night vision and progressive loss of photoreceptors, eventually leading to blindness. This degenerative process primarily affects peripheral vision due to the loss of rods. Autosomal recessive RP (arRP) is clinically and genetically heterogeneous. It has been associated with mutations in different genes, including CRB1 (Crumbs homolog 1). The aim of this study was to determine the causative gene in a Tunisian patient with arRP born to non consanguineous parents.Methods: Four accessible family members were included. They underwent full ophthalmic examination with best corrected Snellen visual acuity, fundus photography and fluoroangiography. Haplotype analyses were used to test linkage in the family to 20 arRP loci, including ABCA4, LRAT, USH2A, RP29, CERKL, CNGA1, CNGB1, CRB1, EYS, RP28, MERTK, NR2E3, PDE6A, PDE6B, RGR, RHO, RLBP1, TULP1. All exons and intron-exon junctions of candidate genes not excluded by haplotype analysis were PCR amplified and directly sequenced.Results: A 39 aged affected member was individualized. Best corrected visual acuity was OR: 20/63, OS: 20/80. Visual loss began at the third decade. Funduscopic examination and FA revealed typical advanced RP changes with bone spicule-shaped pigment deposits in the posterior pole and the mild periphery along with retinal atrophy, narrowing of the vessels and waxy optic discs. Haplotypes analysis revealed homozygosity with microsatellites markers D1S412 and D1S413 on chromosome 1q31.3. These markers flanked the CRB1 gene. Our results excluded linkage of all the other arRP loci/ genes tested. Sequencing of the 12 coding exons and splice sites of CRB1 gene disclosed a homozygous missense mutation in exon 7 at nucleotide c.(2291 G>A), resulting in an Arg to Hist substitution (p.R764H).Conclusions: R764H is a novel mutation associated with CRB1-related arRP. Previously, an R764C mutation was observed. Extending the mutation spectrum of CRB1 with additional families is important for genotype-phenotype correlations.

Instrumentation and Monitoring of Precast Bridge Approach Tied to an Integral Abutment Bridge in Bremer County, SPR 0000-005, 2010

Approach slab pavement at integral abutment (I-A) bridges are prone to settlement and cracking, which has been long recognized by the Iowa Department of Transportation (DOT). A commonly recommended solution is to integrally attach the approach slab to the bridge abutment. This study sought to supplement a previous project by instrumenting, monitoring, and analyzing the behavior of an approach slab tied to a integral abutment bridge. The primary objective of this investigation was to evaluate the performance of the approach slab. To satisfy the research needs, the project scope involved reviewing a similar previous study, implementing a health monitoring system on the approach slab, interpreting the data obtained during the evaluation, and conducting periodic visual inspections of the bridge and approach slab. Based on the information obtained from the testing, the following general conclusions were made: the integral connection between the approach slab and the bridge appears to function well with no observed distress at this location and no relative longitudinal movement measured between the two components; the measured strains in the approach slabs indicate a force exists at the expansion joint and should be taken into consideration when designing both the approach slab and the bridge and the observed responses generally followed an annual cyclic and/or short term cyclic pattern over time; the expansion joint at one side of the approach slab does not appear to be functioning as well as elsewhere; much larger frictional forces were observed in this study compared to the previous study.

Rubber Buffings for Bridge Approach Expansion Joints, MLR-01-01, 2001

Many of the bridges in the state of Iowa have type ‘CF’, ‘EE’, or ‘EF’ expansion joints installed in the bridge approach slabs. These joints, which are typically 4” wide, are currently filled with a foam expansion joint material that is covered with a sealant. Over time the sealant begins to pull off of the walls of the joint and it ultimately fails. The joint, which is now exposed to the weather, is then filled with water and solids. The foam joint material, which is lighter than water, floats out of the joint onto the highway. This foam resembles a large 4” X 6” plank and poses a threat to motorists. A possible solution to this problem would be to replace the foam material with rubber buffings. Rubber buffings are a by-product of the tire retread industry.

Constructability in the Bridge Design Process, HR-320, 1991

In the United States many bridge structures have been designed without consideration for their unique construction problems. Many problems could have been avoided if construction knowledge and experience was utilized in the design process. A systematic process is needed to create and capture construction knowledge for use in the design process. This study was conducted to develop a system to capture construction considerations from field people and incorporate it into a knowledge-base for use by the bridge designers. This report presents the results of this study. As a part of this study a microcomputer-based constructability system has been developed. The system is a user-friendly microcomputer database which codifies construction knowledge, provides easy access to specifications, and provides simple design computation checks for the designer. A structure for the final database was developed and used in the prototype system. A process for collecting, developing and maintaining the database is presented and explained. The study involved a constructability survey, interviews with designers and constructors, and visits to construction sites to collect constuctability concepts. The report describes the development of the constructability system and addresses the future needs for the Iowa Department of Transportation to make the system operational. A user's manual for the system is included along with the report.

Investigation of Two Bridge Alternatives for Low Volume Roads, Volume 1 of 2 Concept 1: Precast Steel Beam Units, HR-382, 1997

Recent reports have indicated that 23.5% of the nation's highway bridges are structurally deficient and 17.7% are functionally obsolete. A significant number of these bridges are on the Iowa secondary road system where over 86% of the rural bridge management responsibilities are assigned to the counties. Some of the bridges can be strengthened or otherwise rehabilitated, but many more are in need of immediate replacement. In a recent investigation (HR-365 "Evaluation of Bridge Replacement Alternatives for the County Bridge System") several types of replacement bridges that are currently being used on low volume roads were identified. It was also determined that a large number of counties (69%) have the ability and are interested in utilizing their own forces to design and construct short span bridges. In reviewing the results from HR-365, the research team developed one "new" bridge replacement concept and a modification of a replacement system currently being used. Both of these bridge replacement alternatives were investigated in this study, the results of which are presented in two volumes. This volume (Volume 1) presents the results of Concept 1 - Steel Beam Precast Units. Concept 2 - Modification of the Beam-in-Slab Bridge is presented in Volume 2. Concept 1, involves the fabrication of precast units (two steel beams connected by a concrete slab) by county work forces. Deck thickness is limited so that the units can be fabricated at one site and then transported to the bridge site where they are connected and the remaining portion of the deck placed. Since Concept 1 bridge is primarily intended for use on low-volume roads, the precast units can be constructed with new or used beams. In the experimental part of the investigation, there were three types of static load tests: small scale connector tests, "handling strength" tests, and service and overload tests of a model bridge. Three finite element models for analyzing the bridge in various states of construction were also developed. Small scale connector tests were completed to determine the best method of connecting the precast double-T (PCDT) units. "Handling strength" tests on an individual PCDT unit were performed to determine the strength and behavior of the precast unit in this configuration. The majority of the testing was completed on the model bridge [L=9,750 mm (32 ft), W=6,400 mm (21 ft)] which was fabricated using the precast units developed. Some of the variables investigated in the model bridge tests were number of connectors required to connect adjacent precast units, contribution of diaphragms to load distribution, influence of position of diaphragms on bridge strength and load distribution, and effect of cast-in-place portion of deck on load distribution. In addition to the service load tests, the bridge was also subjected to overload conditions. Using the finite element models developed, one can predict the behavior and strength of bridges similar to the laboratory model as well as design them. Concept 1 has successfully passed all laboratory testing; the next step is to field test it.

Investigation of Two Bridge Alternatives for Low Volume Roads - Phase II Volume 1 of 2 Concept 1: Steel Beam Precast Units, TR-410, 2000

This project continues the research which addresses the numerous bridge problems on the Iowa secondary road system. It is a continuation (Phase 2) of Project HR-382, in which two replacement alternatives (Concept 1: Steel Beam Precast Units and Concept 2: Modification of the Benton County Beam-in-Slab Bridge) were investigated. In previous research for concept 1, a precast unit bridge was developed through laboratory testing. The steel-beam precast unit bridge requires the fabrication of precast double-tee (PCDT) units, each consisting of two steel beams connected by a reinforced concrete deck. The weight of each PCDT unit is minimized by limiting the deck thickness to 4 in., which permits the units to be constructed off-site and then transported to the bridge site. The number of units required is a function of the width of bridge desired. Once the PCDT units are connected, a cast-in-place reinforced concrete deck is cast over the PCDT units and the bridge railing attached. Since the steel beam PCDT unit bridge design is intended primarily for use on low-volume roads, used steel beams can be utilized for a significant cost savings. In previous research for concept 2, an alternate shear connector (ASC) was developed and subjected to static loading. In this investigation, the ASC was subjected to cyclic loading in both pushout specimens and composite beam tests. Based on these tests, the fatigue strength of the ASC was determined to be significantly greater than that required in typical low volume road single span bridges. Based upon the construction and service load testing, the steel-beam precast unit bridge was successfully shown to be a viable low volume road bridge alternative. The construction process utilized standard methods resulting in a simple system that can be completed with a limited staff. Results from the service load tests indicated adequate strength for all legal loads. An inspection of the bridge one year after its construction revealed no change in the bridge's performance. Each of the systems previously described are relatively easy to construct. Use of the ASC rather than the welded studs significantly simplified the work, equipment, and materials required to develop composite action between the steel beams and the concrete deck.

Comment tes médecins de famille prennent-ils en charge l'hypothyroïdie infraclinique [How do Swiss family physicians treat subclinical hypothyroidism?].

L'hypothyroïdie infraclinique est fréquemment rencontrée et sa prévalence augmente avec l'âge. Les recommandations relatives au dépistage et au traitement de l'hypothyroïdie infraclinique sont controversées. Une enquête internationale auprès des médecins de famille, à laquelle la Suisse a participé, a mis en évidence de fortes variations dans la prise en charge de l'hypothyroïdie infraclinique entre les pays. Ces différences de traitement traduisent avant tout le manque de données fiables quant à la prise en charge de cette condition. L'essai clinique randomisé européen TRUST devrait permettre de clarifier les indications pour le dépistage et la substitution par thyroxine. Une collaboration avec les médecins de famille et le soutien des Instituts universitaires de médecine générale à Lausanne et à Berne pour le recrutement des patients devraient permettre d'obtenir des données directement applicables à une population représentative de la médecine ambulatoire. Subclinical hypothyroidism is a common condition, and its prevalence increases with age. Currently, guidelines regarding the screening and treatment of subclinical hypothyroidism are controversial. An international survey of general practitioners (GPs), to which Swiss GPs also contributed, showed large inter-country variations in treatment strategies for subclinical hypothyroidism. These differences are mainly explained by the lack of strong evidence for the management of this condition. The European randomized-controlled clinical trial TRUST should help clarify recommendations for screening and thyroxin replacement for the elderly with subclinical hypothyroidism. Working in close collaboration with GPs in Switzerland for the recruitment of patients will ensure that the findings from this study will be applicable to primary care settings.

A-1 - Monthly Public Assistance Statistical Report Family Investment Program, January 2014

A-1 - Monthly Public Assistance Statistical Report Family Investment Program

Alternate Methods of Bridge Strengthening, HR-302, 1989

The need for upgrading a large number of understrength and obsolete bridges in the United States has been well documented in the literature. Through the performance of several Iowa DOT projects, the concept of strengthening bridges (simple and continuous spans) by post-tensioning has been developed. The purpose of this project was to investigate two additional strengthening alternatives that may be more efficient than post-tensioning in certain situations. The research program for each strengthening scheme included a literature review, laboratory testing of the strengthening scheme, and a finite-element analysis of the scheme. For clarity the two strengthening schemes are presented separately. In Part 1 of this report, the strengthening of existing steel stringers in composite steel beam concrete-deck bridges by providing partial end restraint was shown to be feasible. Part 2 of this report summarizes the research that was undertaken to strengthen the negative moment regions of continuous, composite bridges. Two schemes were investigated: post-compression of stringers and superimposed trusses within the stringers.

Strengthening of an Existing Continuous-Span, Steel-Beam, Concrete-Deck Bridge by Post-Tensioning, HR-308, 1990

The need to upgrade a large number of understrength and obsolete bridges in the U.S. has been well documented in the literature. Through several Iowa DOT projects, the concept of strengthening simple-span bridges by post-tensioning has been developed. The purpose of the project described in this report was to investigate the use of post-tensioning for strengthening continuous composite bridges. In a previous, successfully completed investigation, the feasibility of strengthening continuous, composite bridges by post-tensioning was demonstrated on a laboratory 1/3-scale-model bridge (3 spans: 41 ft 11 in. x 8 ft 8 in.). This project can thus be considered the implementation phase. The bridge selected for strengthening was in Pocahontas County near Fonda, Iowa, on County Road N28. With finite element analysis, a post-tensioning system was developed that required post-tensioning of the positive moment regions of both the interior and exterior beams. During the summer of 1988, the strengthening system was installed along with instrumentation to determine the bridge's response and behavior. Before and after post-tensioning, the bridge was subjected to truck loading (1 or 2 trucks at various predetermined critical locations) to determine the effectiveness of the strengthening system. The bridge, with the strengthening system in place, was inspected approximately every three months to determine any changes in its appearance or behavior. In 1989, approximately one year after the initial strengthening, the bridge was retested to identify any changes in its behavior. Post-tensioning forces were removed to reveal any losses over the one-year period. Post-tensioning was reapplied to the bridge, and the bridge was tested using the same loading program used in 1988. Except for at a few locations, stresses were reduced in the bridge the desired amount. At a few locations flexural stresses in the steel beams are still above 18 ksi, the allowable inventory stress for A7 steel. Although maximum stresses are above the inventory stress by about 2 ksi, they are about 5 ksi below the allowable operating stress; therefore, the bridge no longer needs to be load-posted.

Composite Precast Prestressed Concrete Bridge Slabs, HR-310, 1991

Precast prestressed concrete panels have been used as subdecks in bridge construction in Iowa and other states. To investigate the performance of these types of composite slabs at locations adjacent to abutment and pier diaphragms in skewed bridges, a research prcject which involved surveys of design agencies and precast producers, field inspections of existing bridges, analytical studies, and experimental testing was conducted. The survey results from the design agencies and panel producers showed that standardization of precast panel construction would be desirable, that additional inspections at the precast plant and at the bridge site would be beneficial, and that some form of economical study should be undertaken to determine actual cost savings associated with composite slab construction. Three bridges in Hardin County, Iowa were inspected to observe general geometric relationships, construction details, and to note the visual condition of the bridges. Hairline cracks beneath several of the prestressing strands in many of the precast panels were observed, and a slight discoloration of the concrete was seen beneath most of the strands. Also, some rust staining was visible at isolated locations on several panels. Based on the findings of these inspections, future inspections are recommended to monitor the condition of these and other bridges constructed with precast panel subdecks. Five full-scale composite slab specimens were constructed in the Structural Engineering Laboratory at Iowa State University. One specimen modeled bridge deck conditions which are not adjacent to abutment or pier diaphragms, and the other four specimens represented the geometric conditions which occur for skewed diaphragms of 0, 15, 30, and 40 degrees. The specimens were subjected to wheel loads of service and factored level magnitudes at many locations on the slab surface and to concentrated loads which produced failure of the composite slab. The measured slab deflections and bending strains at both service and factored load levels compared reasonably well with the results predicted by simplified Finite element analyses of the specimens. To analytically evaluate the nominal strength for a composite slab specimen, yield-line and punching shear theories were applied. Yield-line limit loads were computed using the crack patterns generated during an ultimate strength test. In most cases, these analyses indicated that the failure mode was not flexural. Since the punching shear limit loads in most instances were close to the failure loads, and since the failure surfaces immediately adjacent to the wheel load footprint appeared to be a truncated prism shape, the probable failure mode for all of the specimens was punching shear. The development lengths for the prestressing strands in the rectangular and trapezoidal shaped panels was qualitatively investigated by monitoring strand slippage at the ends of selected prestressing strands. The initial strand transfer length was established experimentally by monitoring concrete strains during strand detensioning, and this length was verified analytically by a finite element analysis. Even though the computed strand embedment lengths in the panels were not sufficient to fully develop the ultimate strand stress, sufficient stab strength existed. Composite behavior for the slab specimens was evaluated by monitoring slippage between a panel and the topping slab and by computation of the difference in the flexural strains between the top of the precast panel and the underside of the topping slab at various locations. Prior to the failure of a composite slab specimen, a localized loss of composite behavior was detected. The static load strength performance of the composite slab specimens significantly exceeded the design load requirements. Even with skew angles of up to 40 degrees, the nominal strength of the slabs did not appear to be affected when the ultimate strength test load was positioned on the portion of each slab containing the trapezoidal-shaped panel. At service and factored level loads, the joint between precast panels did not appear to influence the load distribution along the length of the specimens. Based on the static load strength of the composite slab specimens, the continued use of precast panels as subdecks in bridge deck construction is recommended.

Strengthening of an Existing Continuous-Span, Steel-Stringer, Concrete-Deck Bridge, HR-333, 1993

The need to upgrade understrength bridges in the United States has been well documented in the literature. The concept of strengthening steel stringer bridges in Iowa has been developed through several Iowa DOT projects. The objective of the project described in this report was to investigate the use of one such strengthening system on a three-span continuous steel stringer bridge in the field. In addition, a design methodology was developed to assist bridge engineers with designing a strengthening system to obtain the desired stress reductions. The bridge selected for strengthening was in Cerro Gordo County near Mason City, Iowa on County Road B65. The strengthening system was designed to remove overstresses that occurred when the bridge was subjected to Iowa legal loads. A two part strengthening system was used: post-tensioning the positive moment regions of all the stringers and superimposed trusses in the negative moment regions of the two exterior stringers at the two piers. The strengthening system was installed in the summers of 1992 and 1993. In the summer of 1993, the bridge was load tested before and after the strengthening system was activated. The load test results indicate that the strengthening system was effective in reducing the overstress in both the negative and positive regions of the stringers. The design methodology that was developed includes a procedure for determining the magnitude of post-tensioning and truss forces required to strengthen a given bridge. This method utilizes moment and force fractions to determine the distribution of strengthening axial forces and moments throughout the bridge. Finite element analysis and experimental results were used in the formulation and calibration of the methodology. A spreadsheet was developed to facilitate the calculation of these required strengthening forces.

A-1 - Monthly Public Assistance Statistical Report Family Investment Program, February 2014

A-1 - Monthly Public Assistance Statistical Report Family Investment Program

Bridge Inspection Manual, TR-646, 2014

The purpose of this manual is to organize, document, and combine Iowa Department of Transportation (Iowa DOT) policies and procedures for bridge inspection practices and post-inspection recommendations so Iowa DOT personnel, local agencies, and consultants will have a readily available resource for their use. Previously, bridge inspection policies and procedures were documented by various means, making it difficult to provide consistent answers to questions regarding bridge inspection topics. This manual is intended to ensure uniformity and document best practices for inspection of Iowa’s bridges, especially as experienced inspection personnel retire.

Bridge Rating Manual, TR-646, 2014

The purpose of this manual is to document the Iowa Department of Transportation (Iowa DOT) policy and procedures for load rating and posting of structures within the State of Iowa. This manual is intended to ensure that every bridge is rated as to its safe load carrying capacity. This manual presents guidelines and procedures for rating bridges and outlines the documentation required