Developing Crash Modification Factors for Horizontal Curves on Rural Two-Lane Undivided Highways Using a Cross-Sectional Study

2017 ◽  
Vol 2636 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Lingtao Wu ◽  
Dominique Lord ◽  
Srinivas Reddy Geedipally
Keyword(s):  
Regression Models ◽  
Cross Sectional Study ◽  
Highway Safety ◽  
Sectional Study ◽  
Cross Sectional ◽  
Highway Safety Manual ◽  
Horizontal Curves ◽  
Before And After ◽  
Crash Modification Factors ◽  
Curve Radius

Horizontal curves have been identified as experiencing more crashes than tangent sections on roadways, especially on rural two-lane highways. The first edition of the Highway Safety Manual provides crash modification functions (CM functions) for curves on rural two-lane highways. The CM functions proposed in the manual may suffer from both outdated data and analysis technique. Before-and-after studies are usually the preferred method for estimating the safety effects of treatments. Unfortunately, this method is not feasible for curves. Previous studies have frequently used regression models for developing CM functions for horizontal curves. As recently documented in the literature, some potential problems exist with using regression models to develop crash modification factors. This research utilized a cross-sectional study to develop curvature CM functions. Curves located on Texas rural two-lane undivided highways were divided into a number of bins based on the curve radius. Safety was predicted with the assumption that these curves had been tangents. The observed number of crashes that occurred on the curves was compared with the dummy tangents and for different bins. The results showed that the horizontal curve radius has a significant role in the risk of a crash. From these results, a new CM function was developed. The prediction performance of the Highway Safety Manual CM function was compared with the new CM function in this study and another function that was recently proposed in the literature. It was found that the new CM function documented in this study outperformed both.

scholarly journals Safety Evaluation of Shoulder Bypass Lanes at Unsignalized Intersections on Rural Two-Lane Roadways Using Cross Sectional Analysis

2016 ◽  
Author(s):  
Sunanda Dissanayake ◽  
Alireza Shams
Keyword(s):  
Low Cost ◽  
Safety Evaluation ◽  
Cross Sectional Study ◽  
Highway Safety ◽  
Sectional Study ◽  
Cross Sectional ◽  
Crash Data ◽  
Study Approach ◽  
Unsignalized Intersections ◽  
Before And After

Construction of bypass lanes at rural intersections has typically been considered a low-cost highway safety improvement by the transportation community. However, this needs to be quantitatively evaluated so that the decisions could be made on whether to continue with adding bypass lanes. Highway safety analyses utilize two common approaches to evaluate the effectiveness of a geometric treatment: before-and-after study and cross-sectional study. This paper explains the results using a cross-sectional study approach, where intersections with bypass lanes were compared to intersections with no bypass lanes for which crash data were obtained for more than 1,100 intersections in Kansas. Both 3-legged and 4-legged intersections were taken into consideration separately by looking at intersection-related crashes and crashes within an intersection box. According to the results, the number of crashes and crash severities were lower at 3-legged intersections with bypass lanes compared with 3-legged intersections without bypass lanes, even though these reductions were not statistically significant at 95% level. When considering a 300-ft. intersection box, statistically significant crash reductions were observed at 4-legged intersections, for all considered crash and crash rate categories. When considering 90% level, crash reduction at 3-legged intersections was also statistically significant when considering a 300-ft. intersection box. Crash modification factors (CMFs) calculated to evaluate safety effectiveness of bypass lanes at unsignalized rural intersections in Kansas showed values less than 1.0 for almost all cases, indicating safety benefits of bypass lanes. Accordingly, it is beneficial to continue with the practice of adding shoulder bypass lanes at rural unsignalized intersections on two-lane roads where the traffic volumes are relatively low.

scholarly journals Hemoglobin curves during pregnancy before and after fortification of flours with iron

2014 ◽  
Vol 48 (3) ◽  
pp. 409-414 ◽  
Author(s):  
Ana Paula Sayuri Sato ◽  
Elizabeth Fujimori ◽  
Sophia Cornbluth Szarfarc
Keyword(s):  
Regression Models ◽  
Polynomial Regression ◽  
First Trimester ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Significance Level ◽  
Before And After ◽  
Polynomial Regression Models ◽  
Evaluation Of Public Policies

Objective: To assess the level of hemoglobin-Hb during pregnancy before and after fortification of flours with iron. Method: A cross-sectional study with data from 12,119 pregnant women attended at a public prenatal from five macro regions of Brazil. The sample was divided into two groups: Before-fortification (birth before June/2004) and After-fortification (last menstruation after June/2005). Hb curves were compared with national and international references. Polynomial regression models were built, with a significance level of 5%. Results: Although the higher levels of Hb in all gestational months after-fortification, the polynomial regression did not show the fortification effect (p=0.3). Curves in the two groups were above the references in the first trimester, with following decrease and stabilization at the end of pregnancy. Conclusion: Although the fortification effect was not confirmed, the study presents variation of Hb levels during pregnancy, which is important for assistencial practice and evaluation of public policies.


scholarly journals 732. Evaulation of Micafungin Treatment at Pediatric Patients: A cross-sectional Study from Tertiary Pediatric Centre

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S416-S417
Author(s):  
Kamile Arıkan ◽  
Nuri Bayram ◽  
İlker devrim ◽  
Ayküke Akaslan-Kara
Keyword(s):  
Amphotericin B ◽  
Liver Function Tests ◽  
Cross Sectional Study ◽  
Resistance Rate ◽  
Sectional Study ◽  
Candida Spp ◽  
Cross Sectional ◽  
Median Serum ◽  
Before And After ◽  
Resistance Patterns

Abstract Background Micafungin is one of three currently available echinocandin for treatment of candidiasis and candidemia. Methods Children who were treated for micafungin for possible or proven invasive Candidia infection between May 2017 and October 2019 were included. Results In this cross-sectional study, totally 78 children with a median age of 3 months (8 days -17 years), 50 (64.1%, F/M: 0.56) male were included. Thirty four (43.6%) patients were neonate, 26 (76 %) of them were premature. Thirty seven patients (47.4%) received micafungin for candidemia and 41 (52.6%) patients received micafungin empirically for IC. Twelve (32.4%) Candida spp cultured were C. albicans, the rest twenty five (67.6%) Candida spp were non-albicans Candida spp. The most commonly cultured Candida spp was Candida parapsilosis (C. parapsilosis) (n=13) followed by C. albicans (n=12), C. glabrata (n=3), C. tropicalis (n=3), C. guilliermondii (n=3), C. krusei (n=2) respectively. Resistance rate of C. parapsilosis (n=13) isolates to fluconazole, voriconazole, amphotericin B, caspofungin, micafungin were as follows respectively; 66.7%, 100%, 69.2%, 90.9%, 37.5% respectively. Resistance rate of C. albicans (n=11) isolates to fluconazole, voriconazole, amphotericin B, caspofungin, micafungin were as follows respectively; 50%, 50%, 12.5%, 42.9%, 0% respectively. None of the C. tropicalis, C. guilliermondii and C. krusei isolates were resistant to micafungin. Culture negativity could not be achieved at the end of 14th day of micafungin treatment in the 15 (16.9%) candidemia episodes. The most commonly isolated Candida spp in patients with treatment failure was C. parapsilosis (n=7), the other species were; C. albicans (n=5), C. guilliermondii (n=1), C. tropicalis (n=1) and C. tropicalis and C. guilliermondii coinfection (n=1) respectively. Median serum AST, ALT and creatinin levels didn’t increase during and at the end of micafungin therapy. None of these patients had experienced an anormal kidney or liver function tests due to micafungin usage. Characteristics of patients who received micafungin.and cultured Candida spp Antifungal resistance patterns of Candida spp. Laboratory change before and after micafungin treatment Conclusion Increase in fluconazole resistant Candida spp makes micafungin a reasonable and effective choice for suspected or proven invasive candidiasis Disclosures All Authors: No reported disclosures

scholarly journals The multimorbidity of hypertension and osteoarthritis and relation with sleep quality and hyperlipemia/hyperglycemia in China’s rural population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Ran ◽  
Qi Chen ◽  
Jingyi Zhang ◽  
Xinlong Tu ◽  
Xiaodong Tan ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Regression Models ◽  
Joint Effect ◽  
Cross Sectional Study ◽  
Poor Sleep ◽  
Sectional Study ◽  
Additive Interaction ◽  
Cross Sectional ◽  
Logistic Regression Models ◽  
Remote Rural Area

AbstractHypertension (HTN) and osteoarthritis (OA) are frequent in middle-aged and elderly people, and the co-occurrence of these two diseases is common. However, the pathogenesis of the multimorbidity of both diseases and the relation with sleep quality, hyperlipemia, and hyperglycemia is unclear. We conducted a cross-sectional study to make sense of the multimorbidity of HTN and OA and the relation with sleep quality, hyperlipemia, and hyperglycemia. The relation between sleep quality and OA and its joint effect with hyperlipemia or hyperglycemia was evaluated with logistic regression models. The additive interaction was assessed with the relative excess risk due to interaction (REEI), the attributable proportion (AP), and the synergy index (S). According to this research in a remote rural area, approximately 34.2% of HTN patients are accompanied with OA and 49.1% are suffering poor sleep. Both hyperlipemia/hyperglycemia and sleep quality were related to OA prevalence with crude ORs of 1.43 (95% CI 1.014–2.029) and 1.89 (95% CI 1.411–2.519, P < 0.001) respectively. An observed additive effect was found greater than the sum of the effects of sleep quality and hyperlipemia/hyperglycemia posed on OA prevalence alone. This additive interaction was observed in females (OR = 3.19, 95% CI 1.945–5.237) as well as males ≥ 65 years old (OR = 2.78, 95% CI 1.693–4.557), with RERI, AP, and S significant. Therefore, poor sleep and hyperlipemia/hyperglycemia are associated with OA, and further studies on the additive interaction among females and males ≥ 65 are warranted.

scholarly journals The Impact of Bariatric Surgery on Menstrual Abnormalities—a Cross-Sectional Study

2020 ◽  
Vol 30 (11) ◽  
pp. 4505-4509
Author(s):  
Anna Różańska-Walędziak ◽  
Paweł Bartnik ◽  
Joanna Kacperczyk-Bartnik ◽  
Krzysztof Czajkowski ◽  
Maciej Walędziak
Keyword(s):  
Bariatric Surgery ◽  
Menstrual Cycle ◽  
Cross Sectional Study ◽  
Reproductive Age ◽  
Obese Women ◽  
Sectional Study ◽  
Cross Sectional ◽  
Contraception Use ◽  
Before And After ◽  
The Impact

Abstract Introduction Obesity is associated with hyperestrogenism along with other hormonal abnormalities affecting the menstrual cycle. The most effective and decisive method of obesity treatment is bariatric surgery. The aim of this study was to analyze the impact of bariatric surgery on menstrual cycle, the incidence of menstrual abnormalities, hyperandrogenism manifestation, and contraception use. Materials and Methods It was a cross-sectional study of 515 pre-menopausal women who had undergone bariatric surgery between 1999 and 2017 in a bariatric center. Data was collected via anonymous questionnaire, and the questions covered a 1-year period before the surgery and the last year before questionnaire completion. Results Before the surgery, 38.6% of the patients reported irregular menstruations in comparison with 25.0% after bariatric surgery (RR = 0.65; 95%CI 0.53–0.79). The mean number of menstruations per year did not differ before and after surgery (10.2 ± 3.9 vs 10.4 ± 3.3; p < .45). There were no statistically significant differences in terms of prolonged menstruations, acne, and hirsutism prevalence. A total of 14.4% of patients before surgery reported estrogen-based contraception use in comparison with 15.0% after the surgery (p < .95). There were no significant differences in the frequency of OC use (11.0% before surgery vs 13.6% 12 months after the surgery vs 11.5% at the moment of survey administration; p < 0.46). Conclusion Bariatric surgery improves the regularity of the menstrual cycle in obese women in reproductive age. The lack of any changes in the combined hormonal contraception (CHC) use, especially OC, before and after bariatric surgery may be a result of a possibly low level of contraception counseling.

scholarly journals Malondialdehyde Levels in Preeclampsia before and after Delivery

1970 ◽  
pp. 143
Author(s):  
Harold Rumopa ◽  
Freddy W. Wagey ◽  
Eddy Suparman
Keyword(s):  
Oxidative Stress ◽  
Plasma Levels ◽  
Cross Sectional Study ◽  
Hplc Method ◽  
Wilcoxon Test ◽  
Sectional Study ◽  
Cross Sectional ◽  
Average Value ◽  
Significant Difference ◽  
Before And After

  Objective: Determine differences plasma levels MDA in preeclampsiabefore and 2 hours after delivery.   Methods: This was an analytic cross-sectional study. Subjectconsists of 23 pregnancies with preeclampsia, where 23 bloodsamples taken before delivery and 23 were taken 2 hours afterdelivery. This study was conducted from August 2016 untilDecember 2016 at Department of Obstetrics and GynecologyFaculty of Medicine Universitas Sam Ratulangi / Prof. Dr. R. D.Kandou Hospital Manado and satellite hospital. Samples weretaken from plasma and analysed using HPLC method at Prodiaclinical laboratory.   Results: In patients with severe preeclampsia before deliverywe found average value (1.4796  0.40819 nmol/ml), minimumvalue (1.03 nmol/ml) and maximal value (2.77 nmol/ml)and 2 hours after delivery with average value (1.2470 0.34324 nmol/ml), minimum value (0.91 nmol/ml), and maximumvalue (2.47 nmol/ml). by using Wilcoxon test, we foundthere were significant differences in plasma levels of MDA (p =0.000).   Conclusion: This significant difference suggests that decreasedplasma levels of MDA 2 hours after delivery and gives the sense thatthere is a relationship between oxidative stress of cells with severepreeclampsia before and shortly after delivery, that MDA is an indicatorof oxidative stress.   Keywords: malondialdehyde, oxidative stress, peroxidation lipid,preeclampsia

Impact of cigarette package warnings on attitudes towards sharing and gifting cigarettes in China: a nationwide study of smokers and non-smokers

2021 ◽  
pp. tobaccocontrol-2020-056160
Author(s):  
Yanhui Liao ◽  
Jinsong Tang ◽  
Ann McNeill ◽  
Brian C Kelly ◽  
Joanna E Cohen
Keyword(s):  
Cross Sectional Study ◽  
Social Practices ◽  
Sectional Study ◽  
Health Warnings ◽  
Cross Sectional ◽  
Percentage Points ◽  
Before And After ◽  
Relationship Of ◽  
The Relationship ◽  
Cigarette Package

BackgroundSharing and gifting cigarettes are common in China. These social practices promote cigarette consumption, and consequently may reduce quit rates in China. This study investigated sharing and gifting cigarettes, and the relationship of observing pictorial health warnings to attitudes towards sharing and gifting cigarettes in China.MethodsWe conducted an online nationwide cross-sectional study of 9818 adults in China. Experiences of sharing and gifting cigarettes, and attitudes towards sharing and gifting cigarettes before and after viewing text and pictorial health warnings on the packages were assessed, and compared between smokers and non-smokers.ResultsMost current smokers reported experiences of sharing (97%) and gifting (around 90%) cigarettes. Less than half of non-smokers reported sharing cigarettes and receiving gifted cigarettes, but over half (61.4%) gave cigarettes as a gift to others. More than half of non-smokers but less than 10% of smokers disagreed with sharing and gifting cigarettes. After observing both text and pictorial health warnings on the packages, disagreement with sharing and gifting cigarettes increased by more than 10 percentage points among both smokers and non-smokers.ConclusionHaving pictorial health warnings on cigarette packages may reduce sharing and gifting cigarettes in China.

Effect of position on intracranial pressure and compliance: a cross-sectional study including 101 patients

2021 ◽  
pp. 1-9
Author(s):  
Linda D’Antona ◽  
Claudia Louise Craven ◽  
Fion Bremner ◽  
Manjit Singh Matharu ◽  
Lewis Thorne ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Linear Regression ◽  
Regression Models ◽  
Cross Sectional Study ◽  
Icp Monitoring ◽  
Linear Regression Models ◽  
Sectional Study ◽  
Csf Dynamics ◽  
Cross Sectional ◽  
Intracranial Compliance

OBJECTIVE A better understanding of the effect of position on intracranial pressure (ICP) and compliance is important for the development of treatment strategies that can restore normal cerebrospinal fluid (CSF) dynamics. There is limited knowledge on the effect of position on intracranial compliance. In this cross-sectional study the authors tested the association of pulse amplitude (PA) with position and the day/night cycle. Additionally, they describe the postural ICP and PA changes of patients with “normal” ICP dynamics. METHODS This single-center retrospective study included patients with suspected and/or confirmed CSF dynamics abnormalities who had been examined with elective 24-hour ICP monitoring between October 2017 and September 2019. Patients had been enrolled in a short exercise battery including four positions: supine, lumbar puncture position in the left lateral decubitus position, sitting, and standing. Each position was maintained for 2 minutes, and mean ICP and PA were calculated for each position. The 24-hour day and night median ICP and PA data were also collected. Linear regression models were used to test the correlation of PA with position and day/night cycle. All linear regressions were corrected for confounders. The postural ICP monitoring results of patients without obvious ICP dynamics abnormality were summarized. RESULTS One hundred one patients (24 males and 77 females) with a mean age of 39 ± 13years (mean ± standard deviation) were included in the study. The adjusted linear regression models demonstrated a significant association of ICP with position and day/night cycle, with upright (sitting and standing) and day ICP values lower than supine and night ICP values. The adjusted linear regression model was also significant for the association of PA with position and day/night cycle, with upright and day PA values higher than supine and night PA results. These associations were confirmed for patients with and without shunts. Patients without clear ICP dynamics abnormality had tighter control of their postural ICP changes than the other patients; however, the difference among groups was not statistically significant. CONCLUSIONS This is the largest study investigating the effect of postural changes on intracranial compliance. The results of this study suggest that PA, as well as ICP, is significantly associated with posture, increasing in upright positions compared to that while supine. Further studies will be needed to investigate the mechanism behind this association.

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