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The perception of dyspnea is influenced by both physiological and psychological factors. We sought to determine whether exertional dyspnea perception could be experimentally manipulated through prior exposure to heightened dyspnea while exercising. We hypothesized that dyspnea perception during exercise would be lower following an induced dyspnea task (IDT). Sixteen healthy participants (eight females, eight males) completed two days of exercise testing. Day 1 involved an incremental cycle exercise test starting at 40 W for females and 60 W for males, increasing by 20 W each minute until volitional exhaustion. Following the maximal exercise test on Day 1, participants completed IDT, involving 5 min of exercise at 70% of peak work rate with 500 mL dead space and external resistance (i.e., 6.8 ± 2.3 cm·H2O·s−1·L−1 inspiration, 3.8 ± 0.7 cm·H2O·s−1·L−1 expiration). Day 2 consisted of an incremental exercise test identical to Day 1. At maximal exercise, there were no differences in oxygen uptake (V̇O2; 44.7 ± 7.7 vs. 46.5 ± 6.3 mL·kg−1·min−1), minute ventilation (120 ± 35 vs. 127 ± 38 L·min−1), dyspnea (6.5 [4, 8.5] vs. 6 [4.25, 8.75]), or leg discomfort (6 [5, 8.75] vs. 7 [5, 9]) between days (all p > 0.05). At 60%–80% of peak V̇O2 (V̇O2peak), dyspnea was significantly lower on Day 2 (−0.75 [−1.375, 0] for 60% and −0.5 [0, −2] for 80%, p 2peak, respectively; p 2peak ( p = 0.05), RPE-L was not different at any intensities nor was the onset of perceived leg discomfort different between days (38% ± 14% vs. 43% ± 10% V̇O2peak, respectively; p = 0.10). Exposure to heightened dyspnea alters exercise-induced dyspnea perception during subsequent submaximal exercise bouts.

The hypercapnic chemoresponse to transient CO2 showed an increase during acute physical activity; however, this response did not persist with further increases in intensity and was not different between participants of different aerobic fitness. Males and females show a differing response to CO2 during exercise when compared with an iso-V̇co2. Our results suggest that adaptations that lead to increased aerobic fitness do not impact the hypercapnic ventilatory response but there is an effect of sex.

Quantifying diaphragm neuromuscular function using cervical magnetic stimulation (CMS) typically uses only a single stimulator (1-Stim) which may be inadequate to maximally stimulate the phrenic nerves. We questioned if using two stimulators (2-Stim) together alters diaphragm neuromuscular function at baseline and following inspiratory pressure threshold loading. Six (n = 3 female) healthy young participants were instrumented with esophageal and gastric balloon tipped catheters and electrodes over the 7-8th intercostal space. With either 1-Stim or 2-Stim an incremental protocol, where the stimulator intensity was progressively increased was completed prior to a series of potentiated twitches. The inspiratory threshold loading test consisted of loaded breathing to failure. Compared to 1-Stim, 2-Stim resulted in significantly greater unpotentiated Pdi

The sacral ratio has been used as a tool for evaluating sacral development in patients with anorectal malformations. Sacral ratios can be calculated by obtaining sacral radiographs in the anteroposterior (AP) and lateral planes. The objective of the study was to determine the correlation and agreement in sacral ratio calculations. In this single institution retrospective cohort study, we reviewed medical charts of all pediatric anorectal malformation patients treated between March 2014 and September 2018 who had both AP and lateral images of their sacrum. All sacral ratios were measured by three radiologists. Pearson’s correlation coefficients and corresponding 95% confidence intervals (CIs) were used to assess the correlation between the AP and lateral radiographs. A weighted Kappa statistic was used to measure the agreement between how the AP and lateral sacral ratios categorized observations into risk groups. Our initial cohort consisted of 646 observations from patients with anorectal malformations who had radiographs obtained in both AP and lateral planes. We excluded all observations (n=76) where the radiographs were deemed to be inadequate or not appropriately centered to measure sacral ratio. For a given pair of measurements, the mean lateral sacral ratio was 0.07 units greater than the AP plane (95% CI 0.06–0.09, paired t-test P-value

Objective To better understand why children born with cloacal anomalies are at a high risk of renal insufficiency, this study aims to determine baseline renal volume in children with cloacal anomalies compared to controls. We hypothesized children with cloacal anomalies would be born with less renal volume. Methods An IRB approved database of children with cloacal anomalies was reviewed. Controls were female patients with two-vessel umbilical cord or preauricular tags who underwent screening renal ultrasound. Children were included if they had a renal ultrasound in the first 3 months of life. Cloacal exstrophy, horseshoe and cross-fused ectopic kidneys were excluded. Total and individual kidney volumes were compared between the two groups. Results The study cohort consisted of 109 patients, 46 (42.2%) cloaca patients and 63 (57.8%) controls. In unadjusted analyses, average total renal volume for cloaca and control patients was 22.4 cm3 versus 25.5 cm3 respectively (p=0.1006), and there was no significant difference when adjusting for age (p=0.3915). The estimated difference in renal unit volume between cloaca patients without solitary kidneys and controls was -1.6 cm3 (95% C.I.: -3.6, 0.4; p=0.1201), and there was no significant difference when adjusting for age (p=0.4725). The age-adjusted difference in renal unit volume between cloaca patients with solitary kidney and controls was 1.8 cm3 (95% CI: -1.1, 4.8; p=0.2148). Conclusions Children with cloacal anomalies have similar baseline renal volumes as children without cloacal anomalies. Therefore, the increased risk of renal insufficiency in this patient population appears to be due to renal injury post-natally.

Imaging is extremely important throughout all phases of care provided to children with anorectal malformations (ARM). A preoperative determination of the patient specific malformation will help establish the operative plan. Moreover, the majority of ARM patients will have an associated anomaly that will require imaging workup for full understanding of those abnormalities prior to addressing the ARM. The complexity of ARM care will mandate continued imaging throughout the post-operative period even in those with straight forward malformations.

The sacral ratio has been used as a tool for evaluating sacral development in patients with anorectal malformations. Sacral ratios can be calculated by obtaining sacral radiographs in the anteroposterior (AP) and lateral planes.The objective of the study was to determine the correlation and agreement in sacral ratio calculations.In this single institution retrospective cohort study, we reviewed medical charts of all pediatric anorectal malformation patients treated between March 2014 and September 2018 who had both AP and lateral images of their sacrum. All sacral ratios were measured by three radiologists. Pearson's correlation coefficients and corresponding 95% confidence intervals (CIs) were used to assess the correlation between the AP and lateral radiographs. A weighted Kappa statistic was used to measure the agreement between how the AP and lateral sacral ratios categorized observations into risk groups.Our initial cohort consisted of 646 observations from patients with anorectal malformations who had radiographs obtained in both AP and lateral planes. We excluded all observations (n=76) where the radiographs were deemed to be inadequate or not appropriately centered to measure sacral ratio. For a given pair of measurements, the mean lateral sacral ratio was 0.07 units greater than the AP plane (95% CI 0.06-0.09, paired t-test P-value0.0001). AP and lateral images had a moderate positive correlation (Pearson's r=0.76, 95% CI 0.73-0.79, P0.0001) and moderate agreement in risk categorization (unweighted kappa = 0.60, P0.0001). AP and lateral readings conducted by all three radiologists had excellent inter-rater reliability with intraclass correlations for AP and lateral sacral ratios of 0.88 and 0.84, respectively.Even though the AP and lateral sacral ratios had moderate positive correlation, the mean sacral ratio determined by images in the lateral plane was 0.07 units greater than the AP plane. AP and lateral sacral ratios concluded different risk categories relatively often. Future studies are needed to determine whether AP or lateral sacral ratios correlate better with continence in patients with anorectal malformations.

This paper describes the use of a system dynamics (SD) computational method to evaluate initial designs or upgrades of security measures to protect a building and its occupants from bioterr...

Aim of the Study The goals of urinary reconstruction in urogenital sinus and cloacal repair include: (1) positioning of the bladder neck above the urogenital diaphragm to maximize future urinary continence, and (2) creating a visible urethra that can be catheterized if needed. A recent algorithm in cloacal reconstruction proposed a urethral length of 1.5 cm as the key determinant in deciding whether to perform a total urogenital mobilization or a urogenital separation, the hypothesis being that a 1.5 cm length urethra is needed for the patient to remain dry. We wondered if the normal female urethral length correlated with this empiric technical determinant. Methods We reviewed voiding cystourethrograms of healthy female patients between ages 6 and 36 months and measured the patient's urethral length. Results Ninety-one children were included. The mean urethral length for patients age 6–12 months was 2.50 cm, age 12–24 months was 2.31 cm, and age 24–36 months was 2.59 cm. There was no difference between the urethral length in the three groups (p = 0.38). Of 91 patients, 87 (96%) had a urethral length > 1.5 cm. Conclusion A urethra of at least 1.5 cm was present in the majority of normal control patients. We believe therefore that for urogenital sinus and cloacal repair, surgeons can extrapolate that patients need a 1.5 cm urethra at the end of the reconstruction. Additional follow-up is needed to determine if this urethral length as an independent factor maintains dryness in the long term after cloacal repair. Type of Study Case Series. Level of Evidence III.

Background Contrast enemas with barium or water-soluble contrast agents are sometimes performed in children with severe intractable constipation to identify anatomical abnormalities. However there are no clear definitions for normal colonic size or abnormalities such as colonic dilation or sigmoid redundancy in children. Objective To describe characteristics of colonic anatomy on air contrast enemas in children without constipation to provide normal values for colonic size ratios in children. Materials and methods We performed a retrospective chart review of children aged 0–5 years who had undergone air contrast enemas for intussusception. The primary outcome measures were the ratios of the diameters and lengths of predetermined colonic segments (lengths of rectosigmoid and descending colon; diameters of rectum, sigmoid, descending colon, transverse colon and ascending colon) in relation to the L2 vertebral body width. Results We included 119 children (median age 2.0 years, range 0–5 years, 68% boys). Colonic segment length ratios did not change significantly with age, although the differences for the rectosigmoid/L2 ratio were borderline significant (P = 0.05). The ratios that involved the rectal and ascending colon diameters increased significantly with age, while diameter ratios involving the other colonic segments did not. Differences by gender and race were not significant. Conclusion These data can be used for reference purposes in young children undergoing contrast studies of the colon.

The objective of the research described in this article is to improve measurement, prediction and optimization of sustainable building material performance by integrating a decision-making framework for sustainable material selection of building materials with a building information modeling (BIM) tool. Integration of a BIM model with a decision-making tool and sustainable material selection addresses the difficulties of making decisions earlier in the design/build process and allows for specific sustainability trade-off analyses to be conducted, using the actual building conditions and characteristics. It is intended to improve the way building material data is utilized in a building throughout its life cycle, and to model the impact of design, maintenance, operations and occupant behavior modification decisions made in an effort to improve the building’s contribution to a sustainable infrastructure. Pertinent information contained within a BIM model is extracted, and utilized in decision making related ...

Supplemental Digital Content is available in the text., Introduction: The videofluoroscopic swallow study (VFSS) remains the primary method to evaluate swallowing function in infants and children. However, limited standards exist to guide the image acquisition during pediatric VFSSs, leading to inadequate images, variable assessment quality, and potential for suboptimal diagnostic accuracy. The goal of this quality improvement project was to standardize the radiological procedure for radiologists at our institution. Methods: A multidisciplinary team of project leaders established 3 imaging standards to target (magnification, the field of view, and pulse repetition rate), based on the best available evidence. The team used the Institute for Healthcare Improvement’s Model for Improvement to guide the project, identified key drivers, and implemented specific interventions. Project leaders observed a total of 170 VFSS examinations, performed by radiology faculty, fellows, and residents over 24 months. The primary outcome for this project was physician compliance with 3 established imaging standards: field of view, magnification, and pulse repetition rate. Project leaders collected data without the radiologists’ knowledge, and also recorded average radiation exposure as a balancing measure during this process. Results: At baseline, compliance with all 3 criteria was 20%. Following interventions designed to improve radiologist performance with the 3 identified standards, the compliance rate reached 100% for the last 50 recorded VFSSs. During this same time, there was no meaningful increase in average radiation exposure compared with the 6 months before the implementation of this project. Conclusions: Compliance with standardized image acquisition of VFSSs can be accomplished using a systematic quality improvement protocol targeting simple, inexpensive interventions.

This paper presents a decision-making tool based on the system dynamics method for building design and operation, and demonstrates the use of the method for the analysis of a building subjected to a bioterrorist attack. A literature review of prior uses of the system dynamics method, focusing mainly on historic uses within civil and environmental engineering and related disciplines is first presented, to make the case for the applicability of the system dynamics method as a decision-making tool for building system design, retrofit, and operation. A proof-of-concept system dynamics model is presented for modeling of an elementary building system subjected to a bioterrorist attack. The proof-of-concept model includes evaluation of modifications to the building and its defenses. The results of the model simulation are presented and compared with previously published data. Use of the output data to improve decision-making in building design, retrofit, and operation is discussed. A method to link an electronic building information model (BIM) of the building to enable the electronic capture of the relevant building features in the system dynamics model is also discussed and demonstrated. Finally, future development of the model and other potential areas of applicability for the modeling methodology are discussed.

Due to the lack of data and experience with designing buildings for a bioterrorism hazard, it is important for civil engineering professionals to understand both the way that risk is currently accounted for in the design of a building for a bioterrorism hazard and the methods for analyzing risks to buildings that can be borrowed from risk analysis professionals. This paper provides a literature survey of four subject areas dealing with the risk analysis of bioterrorism applied to buildings: 1 perception of the risk of bioterrorism; 2 risk analysis of bioterrorism; 3 risk management of bioterrorism risks; and 4 risk communication of bioterrorism risks, and includes an example of a simple risk analysis process for a hypothetical building. Bioterrorism presents building design engineers with new chal- lenges. It is a very unpredictable hazard, and very little data exist to guide building designers and decision makers in protecting buildings from this hazard. Designing a building with bioterrorist attacks in mind involves many different disciplines, including, for example, structural, mechanical, and electrical engineering, architecture, landscape architecture, security design professions, and law enforcement. Large consequences are possible in the event of a successful attack, and many building design engineers have little or no experience with defending against a bioterrorist attack. It is important that a reasonable process for analyzing and dealing with these risks be established, and that the process include issues of risk perception and communication within the risk analysis framework.

As buildings have become larger and house more people, political and societal issues have become more complex, and risks associated with occupying buildings have changed. In particular, since the terrorist attacks of 2001, the anxiety levels and perceived risks of building occupants especially occupants of tall, high-profile buildings have increased. These perceived risks include risks of terrorist attacks, natural disasters, the possibility of bomb threats, and catastrophic fires. The public's perception of risk is already incorporated into building design codes and performance-based design PBD methods for such hazards as earthquakes and fires—explicitly in some cases, implicitly in others. Risk perception will clearly need to be addressed in the design of buildings, as trade-offs in "acceptable" risk versus cost must be made. As terrorism represents a constantly changing design challenge, and is a target-specific hazard, as opposed to a location-specific hazard, it seems unlikely that prescriptive code requirements will be entirely effective at addressing this hazard. PBD codes are a promising approach for design issues that deal with such "cutting-edge" concepts.

A proposed model specification for FRP composite materials for use in civil engineering structural systems is described in this article. The model specification provides a classification systems for FRP materials, describes admissible constituent materials and limits on selected constituent volumes, describes tests for specified mechanical and physical properties, specifies limiting values of selected properties in the as-received condition and in a saturated state, and provides a protocol for predicting long-term property values subjected to accelerated aging based on the Arrhenius model. The model specification is included as an appendix to the article.

This paper presents guidelines for implementing the construction warranty contracting method in the highway construction industry. A logical, step-by-step method for effectively applying the warranty contracting program for use in the highway construction industry is developed. Relevant issues that may present obstacles to the implementation are addressed, while the best practices, compiled from an evaluation of the current industry's state-of-the-art practices, will assist an interested state highway agency in creating a warranty specification. In performing this research, the current use of warranty specifications among state highway agencies was examined, and an in-depth case study of the Wisconsin Department of Transportation's warranty program was conducted.

A model specification for fiber-reinforced polymer (FRP) composite materials for use in civil engineering structural systems was developed. The model specification provides a classification system for FRP materials, describes admissible constituent materials, and specifies limits on selected constituent volumes. The specification provides procedures for qualifying FRP composite laminates and for accepting FRP composite parts constructed of qualified laminates. Test methods to obtain mechanical and physical properties were devised, along with stipulation of limiting values for selected properties for both laminates and parts. Based on the Arrhenius model, a protocol was outlined for predicting long-term property values subjected to accelerated aging.

An increasing number of state highway agencies (SHAs) are using A (cost) + B (time cost) bidding ( A + B bidding) for highway construction. The A + B bidding concept is designed to shorten the total contract time by allowing each contractor to bid the number of days in which the work can be accomplished, in addition to the traditional cost bid. The SHA is then presented with the problem of determining a reasonable range of contract time submitted by the bidders. Most SHAs do not currently restrict the range of B. However, several problems may arise from an unrestricted range of B. First, if no minimum is set for B, a bidder may inflate the cost bid and submit an unreasonably low B, using the excess cost bid to cover the disincentives charged for exceeding the time bid. Second, if no maximum is set for B, then a bidder with a high B and a low-cost bid may be awarded the job and make an unreasonable amount of money from incentive payments. This study develops a quantified model of the price-time bidding contract. A construction cost-versus-time curve is developed from Florida Department of Transportation (DOT) data. The contractor’s price-versus-time curve is then combined with the road-user cost to determine the optimum lower limit to be set on B. Finally, several projects completed by the Florida DOT will be used to illustrate this model.

The use of the Internet, e-mail, and other technologies has been steadily filtering into the building process, creating a concurrent engineering (CE) environment, and enabling collaborative efforts in the building process. The concurrent engineering environment is established by a variety of tools, including internet accessible servers, e-mail, mobile telephones, and many other existing CE tools. Organizations involved in the construction process recognize the need for assessment of benefits resulting from CE tools, but find the evaluation of these benefits difficult and complicated. The project presented in this paper, “project management and organization in the concurrent engineering environment (ProCE),” is applicable to both researchers and practitioners. The ProCE project developed a measuring model, which may be used by future researchers in this area, attempted to measure benefits derived from using the CE environment in construction design and project management routines, and developed guidelines for best practice implementation by practitioners, based on four case studies. The project included the measurement of both the quantitative and qualitative benefit of CE environment implementation in building construction projects using tools that were readily available through application service providers. Measurement of cost and other quantifiable benefits have been extensively studied. Therefore, the majority of the discussion in the current paper will address the ProCE project’s measurement of qualitative benefits.