bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistant hypertension
Authors: MacIntyre Iain M. , Webb David J.
Published: June 2018

Resistant hypertension is defined as a blood pressure above target despite adherence to at least three different antihypertensive agents. The term can be used to identify patients with difficult-to-treat hypertension, who might benefit from specialist investigation and/or treatment. It likely affects 10–15% of patients with hypertension. ‘White coat’ hypertension should be excluded first by the use of out-of-office blood pressure monitoring. Risk factors include obesity, older age, chronic kidney disease, and diabetes.

Treatment is based on identifying and treating any underlying cause and through the use of multiple antihypertensive medications, in particular ensuring adequate diuretic therapy.
The hypertensive child
Authors: Rascher Wolfgang
Published: June 2018

Arterial hypertension is a well-recognized manifestation of various forms of renal disease both in adults and children. In the paediatric age group, standards for normal blood pressure are different from adults and have now been satisfactorily defined as have standards for measuring blood pressure. The epidemic of overweight and obesity in youth is increasing the prevalence of hypertension among children and adolescents. Measurement of blood pressure requires a technique specific for different age groups of the paediatric population, is more complex and requires particular expertise. Reference values in children requires adaptation to the age and size of the child and interpretation must be related to normative values specific for age, sex, and height. Evaluation for causes of secondary hypertension and for end-organ damage is basically similar in children as in adults. This chapter discusses measuring blood pressure, blood pressure standards, definition, classification, clinical presentation, and diagnostic approach to hypertension in children.
Renal replacement therapy in the patient with acute kidney injury
Authors: Won Seo Jang , Mehta Ravindra L.
Published: June 2018

Several techniques for renal replacement therapy are now utilized to manage patients with acute kidney injury including intermittent haemodialysis, continuous renal replacement therapy, sustained low-efficiency dialysis, and peritoneal dialysis. This chapter provides an update on contemporary issues including advances in dialysis technology and its effects on the application of dialysis in acute kidney injury. The timing of initiation, modality choice, optimal dose, and management of complications in dialysis are some of the areas where there is controversy.
Overview of uraemic toxins
Authors: Glorieux Griet , Neirynck Nathalie , Pletinck Anneleen , Schepers Eva , Vanholder Raymond
Published: June 2018

The uraemic syndrome is a complex mixture of organ dysfunctions attributed to the retention of a multitude of compounds that under normal conditions are excreted by healthy kidneys. Although important progress has been made in the identification and characterization of uraemic retention solutes and in the revealing of their pathophysiological effects, this knowledge remains far from complete. Data are discussed on general characteristics of specific uraemic retention solutes, on in vitro and in vivo biological effects and on available observational and interventional studies with respect to their removal and related patient outcome are discussed.
Haemofiltration and haemodiafiltration
Authors: Locatelli Francesco , Manzoni Celestina , Pontoriero Giuseppe , Milia Vincenzo La , Di Filippo Salvatore
Published: June 2018

Many observational studies have consistently shown that high-flux haemodialysis (hf-HD) has positive effects on the survival and morbidity of uraemic patients when compared with low-flux haemodialysis, and mainly considering the results of Membrane Permeability Outcome (MPO) studies there is evidence favouring high-flux treatments. A further improvement in convective treatments is represented by the on-line modality. On-line preparation from fresh dialysate by a cold-sterilizing filtration process is a cost-effective method of providing large volumes of infusion solution. Randomized, controlled, large-sized trials with long follow-up in haemofiltration (HF) are unfortunately lacking, possibly suggesting the difficulties in performing these trials, mainly in providing the same urea Kt/V considered adequate in HD. On-line haemodiafiltration (HDF) is considered the most efficient technique of using high-flux membranes, and clearances of small solutes like urea are higher in HDF than in HF and of middle solutes like β‎‎‎2-microglobulin are higher than in hf-HD. Thus HDF, as a strategy based on simultaneous diffusive and convective transport, may combine the beneficial effects of diffusive standard HD with the possible advantages of convective HF. Five large, randomized controlled trials just concluded are inconclusive in definitively clarifying the impact of on-line HDF on chronic kidney disease stage 5 patient outcomes.
Rejection
Authors: Rush David N. , Nickerson Peter W.
Published: June 2018

Rejection of the transplanted kidney is an important cause of graft loss despite modern cross-matching techniques and immunosuppressive agents. The incidence of acute rejection episodes in the first post-transplant year is down to less than 15% in low-risk recipients, but as many as one-third of allograft losses over 10 years result from alloimmunity. Rejection may occur at any time following transplantation, from minutes—hyperacute, to days—acute, or in the longer term—chronic. Rejection can be predominantly through either T-cell-mediated or antibody-mediated mechanisms. It may present clinically as either abrupt or insidious dysfunction of the graft, or it may be subclinical and thus silent, detected only by protocol biopsy or other technology. The prevention and treatment of T-cell-mediated rejection is usually successful with current immunosuppressive agents. Antibody-mediated rejection, on the other hand, is not easily treated and is the principal cause of late renal allograft loss. This chapter presents the concepts and details of this central issue in clinical transplantation.
Pre-eclampsia and related disorders
Authors: Wiles Kate , Nelson-Piercy Catherine
Published: June 2018

Pre-eclampsia is a pregnancy-specific condition diagnosed by new-onset hypertension and proteinuria after 20 weeks’ gestation. The incidence of pre-eclampsia means that it is both the most prevalent cause of acute kidney injury (AKI) in pregnancy and the commonest glomerular disease in the world. This chapter outlines the diagnosis and management of pre-eclampsia. Particular emphasis is given to the post-partum disease course as this is when a specialist nephrology opinion may be sought. HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome is a variant of severe pre-eclampsia. The most important differential diagnoses of HELLP syndrome are the thrombotic microangiopathies. Pregnancy can act as a trigger for both for new disease and flare of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome. AKI is a common complication of acute fatty liver of pregnancy. The diagnosis and supportive management of this condition are considered.
Antenatal diagnosis and pre-implantation genetic testing
Authors: Flinter Frances
Published: June 2018

Routine pregnancy screening (e.g. ultrasound scan) may lead unexpectedly to the identification of an underlying renal problem whose aetiology may not be apparent immediately. It is important to recognize genetic causes so that associated problems in other organs can be anticipated and the recurrence risk for future pregnancies established. Specific diagnosis at a cytogenetic or molecular level may be essential if the options of early prenatal diagnosis or pre-implantation genetic diagnosis are to be available to the couple in future pregnancies. This chapter discusses the topics of antenatal screening, prenatal diagnosis (including invasive and non-invasive diagnosis and counselling) and intervention, and pre-implantation genetic diagnosis.
Hepatocyte nuclear factor-1B
Authors: Bingham Coralie
Published: June 2018

Hepatocyte nuclear factor-1B (HNF1B, also known as TCF2) is a transcription factor that is involved in renal development, and in the transcription of several genes implicated in other genetic renal diseases. Mutations in HNF1B cause maturity onset diabetes of the young, renal cysts and diabetes syndrome, and some cases of familial juvenile hyperuricaemic nephropathy. They also account for a large proportion of developmental renal disorders included abnormalities detected antenatally. The various abnormalities associated with the gene may occur in isolation or together in the same patient.
Nephronophthisis and medullary cystic kidney disease
Authors: Sayer John A.
Published: June 2018

The inherited cystic kidney conditions nephronophthisis (NPHP) and medullary cystic kidney disease (MCKD) have previously been referred to as a NPHP–MCKD complex. This descriptive term was based on histological studies where the renal pathological features were common to both disorders. Both conditions may also present with insidious renal impairment and a urine concentrating defect, but they are genetically distinct. NPHP is an autosomal recessive disorder leading to established renal failure usually within the first three decades of life, and it is a ciliopathy. In contrast, MCKD is an autosomal dominantly inherited disorder leading to renal failure in later life, typically between 30 and 60 years of age. A molecular genetic diagnosis is helpful for both disorders, allowing a more precise diagnosis, screening of at risk relatives and avoiding the need for renal biopsy. Treatment of both conditions remains supportive.
Molecular basis of nephrotic syndrome
Authors: Saleem Moin A. , Antignac Corinne
Published: June 2018

Nephrotic syndrome is broadly a disorder of the glomerular filtration barrier, but in practice the site of dysfunction in the great majority of pathologies is in the podocyte. Genetic causes of nephrotic syndrome provide the strongest proof of this. Almost all the genetic associations with nephrotic syndrome are podocyte proteins. Some basement membrane protein mutations associated with nephrotic syndrome may act through signalling to podocytes, or by causing severe disruption to their environment.
Fabry disease
Authors: Waldek Stephen
Published: June 2018

Fabry disease is a rare X-linked disorder of glycosphingolipid metabolism caused by a deficiency of the lysosomal acid hydrolase enzyme, alpha-galactosidase A. The resulting accumulation of substrate, mostly globotriaosylceramide, leads to a progressive, multiorgan disease affecting predominantly the kidneys, skin, heart, and nervous system. It is one of over 50 lysosomal storage diseases. It is typically diagnosed in young men after many years of ‘acral pain’ syndrome, when the diagnosis is made through identification of characteristic abnormalities of skin, kidney or heart, or of other organs. Renal failure has been a common outcome. Females may also develop manifestations, usually later in life. Renal biopsy shows vacuoles/deposits in podocytes and other renal cell types with progressive scarring. The diagnosis can be made by measuring enzyme levels in men, or by genetic testing. This latter is the more reliable test in women. Fabry disease can now be treated where affordable by regular (every 2 weeks) intravenous infusions of recombinant preparations of the deficient enzyme. These are burdensome and expensive, but are transforming the outlook for the condition.
String Technique for Anterior Orbital Fish Hook Removal
Authors: Starr Matthew R. , Choi Michael B. , Mahr Michael A. , Mettu Pradeep , Patterson David F.
Published: June 2018

Removing fish hooks is a common procedure performed by many emergency department providers. There are several techniques that are commonly employed to aid in successful removal. However, when a fish hook becomes embedded within the orbit, there are limited options as to avoid damaging vital surrounding structures. The authors report the removal of a fish hook within the anterior orbit using the string technique in a 25-year-old patient. The procedure was performed under general anesthesia with the aid of size 5 polyglactin suture wrapped around the hook. The procedure itself took less than 10 seconds and was successful in swiftly and safely removing the hook without damaging surrounding orbital structures. The patient recovered well without any permanent sequelae.
Measurement of selective constraint on human gene expression
Authors: Glassberg Emily C , Gao Ziyue , Harpak Arbel , Lant Xun , Pritchard Jonathan K
Published: June 2018

Gene expression variation is a major contributor to phenotypic variation in human complex traits. Selection on complex traits may therefore be reflected in constraint on gene expression levels. Here, we explore the effects of stabilizing selection on cis-regulatory genetic variation in humans. We analyze patterns of expression variation at copy number variants and find evidence for selection against large increases in gene expression. Using allele-specific expression (ASE) data, we further show evidence of selection against smaller-effect variants. We estimate that, across all genes, singletons in a sample of 122 individuals have approximately 2.5 × greater effects on expression variance than common variants. Despite their increased effect sizes relative to common variants, we estimate that singletons in the sample studied explain, on average, only 5% of the heritability of gene expression from cis-regulatory variants. Finally, we show that genes depleted for loss-of-function variants are also depleted for cis-eQTLs and have low levels of allelic imbalance, confirming tighter constraint on the expression levels of these genes. We conclude that constraint on gene expression is present, but has relatively weak effects on most cis-regulatory variants, thus permitting high levels of gene-regulatory genetic variation.
Relationships between ultimate pH and antioxidant enzyme activities and gene expression in pork loins
Authors: Wang Jin , Zeng Qi‐fan , Wang Hui , Chen Wei , Zeng Yong‐qing
Published: June 2018

Ultimate pH (pHu) is a major determinant factor of meat quality. In this study, we investigated the effects of pHu on the muscle antioxidant capacity, and the relationship between pHu and muscle antioxidant capacity of pigs. A total of 137 pigs from three pig breeds with the same feeding condition were slaughtered and used to measure the pHu, superoxide dismutase (SOD), glutathione peroxidase (GSH‐PX), total antioxidant capacity (T‐AOC), and malondialdehyde (MDA) content, and gene expression of SOD1 and GPX4. Loins from 137 pigs of three breeds were classified based on pHu into three groups: low (L‐pH: ≤5.50), intermediate (I‐pH: 5.51‐5.90), and high (H‐pH: ≥5.91). A majority of loins (47.5%–52%) were classified into the intermediate group. The results suggested that the pHu value was correlated with the activity of SOD, GSH‐PX, T‐AOC, and MDA, and gene expression of SOD1 and GPX4 in all pigs. In addition, our results also indicated a linear relationship between the pHu value and antioxidant traits. The pHu value accounted for 23%–40% of the variation in the antioxidant traits. These results suggested that increased pHu reduce the lipid peroxidation, and also indicated that pHu may be a key factor explaining the variation in the activity of antioxidant enzymes and gene expression in pork loins.
The association between periodontal disease severity and metabolic syndrome in Vietnamese patients
Authors: Pham TAV
Published: June 2018

Objective

To investigate the association between periodontal disease severity and metabolic syndrome (MetS) in a group of Vietnamese patients.

Methods

A total of 412 participants (114 males, 298 females, average age 57.8 ± 5.7 years) including 206 patients with MetS and 206 participants without MetS were selected for this study. Information on sociodemographic characteristics, dental behaviours and smoking status was collected from a self‐administrated questionnaire. Periodontal status including plaque index (PI), gingival index (GI) pocket depth (PD) and clinical attachment level (CAL) was recorded. Logistic regression analyses were used to evaluate the association between severity of periodontal disease and MetS with adjustments for related confounders.

Results

The prevalence of moderate and severe periodontitis assessed by GI, PD and CAL was all significantly higher in the MetS group than in the control group and was significantly increased by a number of MetS components. Logistic regression, adjusted for confounders, showed that people with mean PI ≥2.51 or GI ≥1.01 or number of teeth with bleeding on probing of ≥20 teeth or PD ≥3.66 or CAL ≥3.66 showed a significant association with greater OR for MetS compared to counterparts (P < .05). The OR for MetS was 4.06 (95% CI 2.11‐7.84) in severe periodontitis patients compared to non‐periodontitis participants (P < .001).

Conclusion

Much severe and extensive periodontal disease was found in MetS participants and increased with number of MetS components. Participants with higher periodontal parameters had a higher risk of MetS.
Relationship of objective street quality attributes with youth physical activity: findings from the Healthy Communities Study
Authors: Kaczynski A. T. , Besenyi G. M. , Child S. , Morgan Hughey S. , Colabianchi N. , McIver K. L. , Dowda M. , Pate R. R. ,   on behalf of the Healthy Communities Study Team
Published: June 2018

Background

Residential environments may significantly influence youth physical activity (PA). However, few studies have examined detailed street quality attributes via observational audits in relation to context‐specific PA among youth.

Objectives

The objective of this study was to explore whether the overall quality of street environments, as well as specific attributes, was associated with neighbourhood‐based and street‐based PA within a national sample of youth in the Healthy Communities Study.

Methods

Data were collected from 4616 youth from 130 communities across the USA. Youth PA in the neighbourhood and on the participant's street was captured using 7‐d recall interviews. Windshield survey observational audits documented five street quality variables: burned, boarded up or abandoned residential units, litter, overall condition of residences, street type and presence of sidewalks in good condition.

Results

Youth with no litter on their street reported significantly lower neighbourhood‐based PA and youth living on a side street, cul‐de‐sac, dead‐end or one‐way street reported greater neighbourhood‐based PA. No significant associations were detected for the overall street quality index or with street‐based PA.

Conclusions

Specific street quality attributes may be associated with youth PA. Further research and collaboration between diverse disciplines and agencies should focus on understanding and improving street quality to promote youth PA and health.
Integrating Behavioral Decision Theory and Sustainable Supply Chain Management: Prioritizing Economic, Environmental, and Social Dimensions in Carrier Selection
Authors: Davis‐Sramek Beth , Thomas Rodney W. , Fugate Brian S.
Published: June 2018

Carrier selection is a specialized sourcing decision with sustainability impacts in every supply chain. This research tests the effects of a transportation carrier's economic, environmental, and social sustainability performance on a shipper's carrier selection decision. Underrepresented experimental methods are used to test an a priori hypothesis derived from behavioral decision theory logic. Results contradict commonly held win–win, trade‐off, and ecological perspectives of sustainable supply chain management by finding that the economic dimension of sustainability has the greatest effect on carrier selection. Our research highlights this managerial preference and offers a theoretically grounded explanation for selection behaviors. This is one of the first empirical studies to simultaneously consider all three dimensions of sustainability. It also moves beyond an internal focal firm focus to evaluate sustainability effects through the eyes of external supply chain members. Our unique approach and findings offer managerial opportunities for differentiation and resource allocation as well as policy implications for the broader transportation system.
The Role of Acceptance of Violence Beliefs and Social Information Processing on Dating Violence Perpetration
Authors: Fernández‐González Liria , Calvete Esther , Orue Izaskun
Published: June 2018

This study's main objective was to explore whether beliefs legitimizing dating violence predict dysfunctional social information processing (SIP) when adolescents deal with ambiguous dating situations, and whether this more proximal cognitive processing acts as a mediator between acceptance of violence beliefs and dating violence perpetration. Participants were 855 high school students who completed self‐report measures at three time points, with a 1‐year interval between them. SIP did not act as a mediator, but the emergence of anger emotions in dating conflict situations, along with aggression‐justifying beliefs, were revealed as essential in explaining dating violence. Previous aggression also explained a subsequent higher anticipation of positive consequences for aggressive acts. We discuss the implications for prevention and treatment strategies with adolescents.
Mechanize or exit farming? Multiple‐treatment‐effects model and external validity of adoption impacts of mechanization among Nepalese smallholders
Authors: Takeshima Hiroyuki
Published: June 2018

The future of smallholders in developing countries is becoming increasingly uncertain in the face of rising farm wages. The custom‐hiring of tractors, in which tractor owners provide non‐owner farmers with land preparation and transport services for fees, has spread among smallholders in Asia, including Nepal. However, estimating the adoption impacts of agricultural mechanization by smallholders is complex as we must also take into account smallholders’ options to exit farming. We investigate this issue by applying multinomial logit inverse‐probability weighting and sample selection panel data methods to data on smallholders in lowland Nepal. Our results are generally consistent with the hypothesis that smallholders who are likely to benefit more from adopting tractors are also more likely to exit farming. Where smallholders are less likely to exit farming, the use of tractors through custom‐hiring may help smallholders on average to earn greater total and agricultural incomes. However, where they are more likely to exit farming, the ability of custom‐hired tractors to sustain smallholder farming systems may become weaker. The results also offer insights into how the external validity of technology adoption impact evaluation may be affected in some settings.
Understanding the interplay between bus, metro, and cab ridership dynamics in Shenzhen, China
Authors: Yue Mengxue , Kang Chaogui , Andris Clio , Qin Kun , Liu Yu , Meng Qingxiang
Published: June 2018

The most common mass transit modes in metropolitan cities include buses, subways, and taxicabs, each of which contribute to an interconnected complex network that delivers urban dwellers to their destinations. Understanding the intertwined usages of these three transit modes at different places and time allows for better sensing of urban mobility and the built environment. In this article, we leverage a comprehensive data collection of bus, metro, and taxicab ridership from Shenzhen, China to unveil the spatio‐temporal interplay between different mass transit modes. To achieve this goal, we develop a novel spectral clustering framework that imposes spatio‐temporal similarities between mass transit mode usage in urban space and differentiates urban spaces associated with distinct ridership patterns of mass transit modes. Five resulting categories of urban spaces are identified and interpreted with auxiliary knowledge of the city's metro network and land‐use functionality. In general, different categorized urban spaces are associated with different accessibility levels (such as high‐, medium‐, and low‐ranked) and different urban functionalities (such as residential, commercial, leisure‐dominant, and home–work balanced). The results indicate that different mass transit modes cooperate or compete based on demographic and socioeconomic attributes of the underlying urban environments. Our proposed analytical framework provides a novel and effective way to explore the mass transit system and the functional heterogeneity in cities. It demonstrates great potential for assisting policymakers and municipal managers in optimizing public transportation facility allocation and city‐wide daily commuting distribution.
Rapid Influence of Word‐Talker Associations on Lexical Access
Authors: Kim Jonny , Drager Katie
Published: June 2018

Previous work on English and Korean demonstrates that words are more quickly identified as real words when they are produced by a voice congruent with the age of the talkers who are most likely to use the word (Kim, 2016, Laboratory Phonology, 7, 18; Walker & Hay, 2011, Laboratory Phonology, 2, 219–237). However, this previous work presents stimuli blocked by voice, giving the participant ample time to form expectations about the talker and the words that the talker would likely use. To test whether the effect can be observed in the absence of cues to talker age prior to word onset, the current experiment replicates Kim (2016, Laboratory Phonology, 7, 18) but without blocking by talker. Results from the current experiment confirm earlier findings and they demonstrate that the effect can be observed even without the listener having any expectations about the talker prior to hearing the word. We discuss the implications of these results for models of speech perception, suggesting that lexical access is rapidly boosted by socio‐indexical phonetic cues that are congruent with socio‐indexical lexical information.
A Testing Rig to Study Vehicle-Track Interaction During Turning
Authors: Otremba Frank , Romero Navarrete José Antonio
Published: June 2018

Developing of testing rigs represents a crucial activity for understanding the behavior of physical systems. A sloshing cargo in a railway tank car involves the dynamic interaction of the cargo-frame systems, characterized by lateral load transfers derived from the motion of the cargo. Such dynamic loads could develop a concentrated damage in the rail. While it has been recognized in the literature the influence of such dynamic sloshing forces on the wheel load exerted on the rails, affecting the lateral stability of the car and, consequently, the level of stress in the rail, no experimental validation has been made for none of these situations, namely, the effect of sloshing cargoes on the lateral stability of the cars, and on the corresponding stress level in the rails. In this paper, an experimental test rig is proposed to study the liquid cargo–tank car interaction when negotiating a turn. The equipment will provide the means to validate a simplified mathematical model, which will allow extensive parametric analyses.
Efficient Reliability-Based Design Tool for Reinforced Earth Retaining Walls of Heavy Haul Railway Considering Internal Failure Modes
Authors: Hu Biao , Luo Zhe , Ho Carlton L. , Wang Youwen
Published: June 2018

This paper presents the development and demonstration of an efficient reliability-based tool for the reinforced earth retaining wall design in heavy haul railway. Here, two major internal failure modes, rupture and pullout, are the focus in the demonstration. The First-Order Reliability Method (FORM) is adopted to estimate the probability of failure for each failure mode, and is implemented in a spreadsheet. The reliability analysis is conducted with the consideration of the effect of uncertainty in the reinforcement length, horizontal and vertical spacing between steel strips, tensile strength of steel strips as well as the material property of the backfills. Using this design tool, a few candidate designs can be easily obtained by meeting the acceptable probability of failure and the final design is determined based on cost. The results obtained using FORM are also verified by comparing with those from Monte Carlo simulation. This design tool is shown to be simple to use in the retaining wall design of the railway engineering.
Development of ‘Coarse to Fine Ratio’ As a New Gradation Parameter to Study Ballast Packing
Authors: Mahmud S. M. Naziur , Mishra Debakanta
Published: June 2018

The Unified Soil Classification System (USCS) uses the 4.75 mm sieve opening size (#4 sieve) as the boundary between ‘coarse’ and ‘fine’ particles. Particles larger than 4.75 mm are classified as ‘coarse’, whereas particles smaller than 4.75 mm are classified as ‘fine’. However, applying these definitions to railroad ballast can be erroneous, as most particles in a ballast material are larger than 4.75 mm (often as large as 63 mm in size), therefore indicating the absence of any ‘fine’ particles. However, depending on relative distribution of particle sizes within a granular matrix, certain particles serve to create voids (coarse fraction), and certain particles serve to fill the voids (fine fraction). Accordingly, rather than using the standard definitions of ‘coarse’ and ‘fine’ particles, as has been done in the literature, the analysis of packing conditions in a ballast matrix may be better served by studying the relative packing between different size fractions. This paper focuses on the development of a new gradation parameter, termed as the “Coarse-to-Fine (C/F) Ratio”, which can shed some light on the importance of different size fractions in a ballast matrix. Changing the ‘coarse’ and ‘fine’ fractions within a particular gradation specification, the resulting effect on ballast shear strength was studied through simulated Direct Shear Strength Tests. A commercially available threedimensional Discrete Element Modeling (DEM) package (PFC3D®) was used for this purpose. Details of the numerical modeling effort are be presented, and inferences are drawn concerning the implications of simulation results on the design and construction of railroad ballast layers.
Material Characteristics Evaluation of Existing Pre-Stressed Concrete Railroad Ties After Service Period
Authors: Shafiei Dastgerdi Aref , Riding Kyle , Peterman Robert J. , Beck B. Terry
Published: June 2018

As an important element in track, pre-stressed concrete railroad ties in the high-speed rail industry must meet the safety and performance specifications of high-speed trains. Systematic destructive and non-destructive evaluation of existing concrete ties can lead to a better understanding of the effect of prestressed concrete tie material design on performance and failure within their service life. It has been evident that environmental and climate conditions also have a significant impact on concrete railroad ties, causing various forms of deterioration such as abrasion and freeze-thaw damage. Understanding of the material characteristics that cause failure in different types of existing concrete railroad ties taken from different places is the main focus of this paper. Observing the current status and damages of railroad ties taken from track might give a correlation between the material characteristic and type of distress and cracking seen. Although it has been seen by previous works that effective factors such as air void system and material composition directly affect the performance of concrete ties such as freeze-thaw, material evaluation of existing ties after service life has not been addressed in previous publications. In this research, the authors have investigated the material characteristic such as aggregate and air-void system of existing pre-stressed concrete railroad ties taken from track. However, compressive and splitting tensile strength and fractured surface of samples cored from the ties were acquired. In order to obtain the strength of concrete materials of existing ties, six samples were cored from six different types of ties taken from tracks across the U.S., according to ASTM C42-16, and tested using ASTM C39 and ASTM C496 methods. However, the concrete air-void system (ASTM C457) was measured on saw-cut samples extracted from the ties to evaluate the influence air content and distribution on mechanical properties of the ties. Regarding the history and service life condition of the ties, it seems that material properties of the ties effectively alter the performance of the ties. Aggregate sources used at each location may have different properties such as texture, angularity, and mineralogy, contributing either propagation or resistance in splitting cracking in concrete. Furthermore, the polished surface of samples extracted from the ties show the uniformity and air void system in some ties which demonstrate their superiority in terms of resistance to freeze-thaw damage. Considering the results of this research, comprehensive evaluation of material characteristics might give a better view of existing concrete railroad ties situation, providing a worthwhile background for future tie design considerations.
Investigating the Rolling Contact Fatigue in Rails Using Finite Element Method and Cohesive Zone Approach
Authors: Ghodrati Mohamad , Ahmadian Mehdi , Mirzaeifar Reza
Published: June 2018

A micromechanical-based 2D framework is presented to study the rolling contact fatigue (RCF) in rail steels using finite element method. In this framework, the contact patch of rail and wheel is studied by explicitly modeling the grains and grain boundaries, to investigate the potential origin of RCF at the microstructural level. The framework incorporates Voronoi tessellation algorithm to create the microstructure geometry of rail material, and uses cohesive zone approach to simulate the behavior of grain boundaries. To study the fatigue damage caused by cyclic moving of wheels on rail, Abaqus subroutines are employed to degrade the material by increasing the number of cycles, and Jiang-Sehitoglu fatigue damage law is employed as evolution law. By applying Hertzian moving cyclic load, instead of wheel load, the effect of traction ratio and temperature change on RCF initiation and growth are studied. By considering different traction ratios (0.0 to 0.5), it is shown that increasing traction ratio significantly increases the fatigue damage. Also by increasing traction ratio, crack initiation migrates from the rail subsurface to surface. The results also show that there are no significant changes in the growth of RCF at higher temperatures, but at lower temperatures there is a measurable increase in RCF growth. This finding correlates with anecdotal information available in the rail industry about the seasonality of RCF, in which some railroads report noticing more RCF damage during the colder months.
Quantum physics could get big boost from U.S. Congress
Authors: Popkin Gabriel
Published: June 2018

Pending legislation seeks to counter foreign investment in quantum computing and related technologies.
The mother of all challenges
Authors: Cohen Jon
Published: June 2018

Nigeria struggles to slow the spread of HIV to babies.
Dark nights, bright stars
Authors: Cohen Jon
Published: June 2018

Russia's explosion of HIV reflects stigma and neglect, but it spotlights courageous actions by a few.
The pill exchange
Authors: Cohen Jon
Published: June 2018

A network of what amount to underground pharmacists shares anti-HIV drugs.
The loyal opposition
Authors: Cohen Jon
Published: June 2018

Vadim Pokrovsky runs the federal AIDS center in Moscow, but criticizes the government response.
Sex reversal following deletion of a single distal enhancer of
Sox9
Authors: Gonen Nitzan , Futtner Chris R. , Wood Sophie , Garcia-Moreno S. Alexandra , Salamone Isabella M. , Samson Shiela C. , Sekido Ryohei , Poulat Francis , Maatouk Danielle M. , Lovell-Badge Robin
Published: June 2018

Sox9
regulation during sex determination

Sex determination is regulated by the
Sox9
gene. During testis differentiation, this gene is directly targeted by the product of the Y chromosome–encoded gene
Sry
. The regulatory region of
Sox9
is complex, which is typical of genes with multiple roles in development. Gonen
et al.
find that a single far-upstream 557–base pair element is critical for up-regulating
Sox9
. Without it, XY mice develop as females instead of males. The 557–base pair enhancer is conserved, likely to be relevant to human disorders of sex differentiation, and probably essential because it acts early in a time-critical process, and any failure allows ovary-specific factors to dominate.

Science
, this issue p.
1469
Platforms of power
Custodians of the Internet
Tarleton Gillespie
Yale University Press, 2018. 296 pp.
Authors: Hoffmann Anna Lauren
Published: June 2018

A Microsoft researcher confronts how companies shape what we see and say online
Understanding spatial environments from images
Authors: Zwicker Matthias
Published: June 2018

An algorithm that is trained to predict views of a spatial environment also infers its 3D structure
Asperger's chilling complicity
Asperger's Children: The Origins of Autism in Nazi Vienna
Edith Sheffer
Norton, 2018. 317 pp.
Authors: Wadman Meredith
Published: June 2018

The physician behind the eponymous syndrome was an active participant in Nazi eugenics
Visual attention on a respiratory function monitor during simulated neonatal resuscitation: an eye-tracking study
Authors: Katz Trixie A , Weinberg Danielle D , Fishman Claire E , Nadkarni Vinay , Tremoulet Patrice , te Pas Arjan B , Sarcevic Aleksandra , Foglia Elizabeth E
Published: June 2018

Objective

A respiratory function monitor (RFM) may improve positive pressure ventilation (PPV) technique, but many providers do not use RFM data appropriately during delivery room resuscitation. We sought to use eye-tracking technology to identify RFM parameters that neonatal providers view most commonly during simulated PPV.

Design

Mixed methods study. Neonatal providers performed RFM-guided PPV on a neonatal manikin while wearing eye-tracking glasses to quantify visual attention on displayed RFM parameters (ie, exhaled tidal volume, flow, leak). Participants subsequently provided qualitative feedback on the eye-tracking glasses.

Setting

Level 3 academic neonatal intensive care unit.

Participants

Twenty neonatal resuscitation providers.

Main outcome measures

Visual attention: overall gaze sample percentage; total gaze duration, visit count and average visit duration for each displayed RFM parameter. Qualitative feedback: willingness to wear eye-tracking glasses during clinical resuscitation.

Results

Twenty providers participated in this study. The mean gaze sample captured wa s 93% (SD 4%). Exhaled tidal volume waveform was the RFM parameter with the highest total gaze duration (median 23%, IQR 13–51%), highest visit count (median 5.17 per 10 s, IQR 2.82–6.16) and longest visit duration (median 0.48 s, IQR 0.38–0.81 s). All participants were willing to wear the glasses during clinical resuscitation.

Conclusion

Wearable eye-tracking technology is feasible to identify gaze fixation on the RFM display and is well accepted by providers. Neonatal providers look at exhaled tidal volume more than any other RFM parameter. Future applications of eye-tracking technology include use during clinical resuscitation.
How good are GPs at adhering to a pragmatic trial protocol in primary care? Results from the ADDITION-Cambridge cluster-randomised pragmatic trial
Authors: Laxy Michael , Wilson Edward C F , Boothby Clare E , Griffin Simon J
Published: June 2018

Objective

To assess the fidelity of general practitioners’ (GPs) adherence to a long-term pragmatic trial protocol.

Design

Retrospective analyses of electronic primary care records of participants in the pragmatic cluster-randomised ADDITION (Anglo-Danish-Dutch Study of Intensive Treatment In People with Screen Detected Diabetes in Primary Care)-Cambridge trial, comparing intensive multifactorial treatment (IT) versus routine care (RC). Data were collected from the date of diagnosis until December 2010.

Setting

Primary care surgeries in the East of England.

Study sample/participants

A subsample (n=189, RC arm: n=99, IT arm: n=90) of patients from the ADDITION-Cambridge cohort (867 patients), consisting of patients 40–69 years old with screen-detected diabetes mellitus.

Interventions

In the RC arm treatment was delivered according to concurrent treatment guidelines. Surgeries in the IT arm received funding for additional contacts between GPs/nurses and patients, and GPs were advised to follow more intensive treatment algorithms for the management of glucose, lipids and blood pressure and aspirin therapy than in the RC arm.

Outcome measures

The number of annual contacts between patients and GPs/nurses, the proportion of patients receiving prescriptions for cardiometabolic medication in years 1–5 after diabetes diagnosis and the adherence to prescription algorithms.

Results

The difference in the number of annual GP contacts (β=0.65) and nurse contacts (β=−0.15) between the study arms was small and insignificant. Patients in the IT arm were more likely to receive glucose-lowering (OR=3.27), ACE-inhibiting (OR=2.03) and lipid-lowering drugs (OR=2.42, all p values <0.01) than patients in the RC arm. The prescription adherence varied between medication classes, but improved in both trial arms over the 5-year follow-up.

Conclusions

The adherence of GPs to different aspects of the trial protocol was mixed. Background changes in healthcare policy need to be considered as they have the potential to dilute differences in treatment intensity and hence incremental effects.

Trial registration number

ISRCTN86769081.
Availability and affordability of biologic versus non-biologic anticancer medicines: a cross-sectional study in Punjab, Pakistan
Authors: Saqib Anum , Iftikhar Sadia , Sarwar Muhammad Rehan
Published: June 2018

Objectives

Prime focus of this study was to evaluate the availability and affordability of originator brands (OBs) and lowest price generics (LPGs) of prescribed biologic and non-biologic anticancer medicines.

Design, settings and participants

A descriptive, cross-sectional survey was conducted in 22 cancer-care hospitals (18 public hospitals and 4 private hospitals) and 44 private pharmacies in Punjab, Pakistan. Sampling population consisted of 4483 patients with cancer aged ≥18 years. The availability was determined by classifying anticancer medicines in four categories: absent/unavailability (medicines not present in any surveyed facility), low availability (medicines present in <50% of surveyed facilities), fairly high availability (medicines present in 50%–74% of surveyed facilities) and high availability (medicines present in >75% of surveyed facilities). Medicines were affordable if overall cost of all the prescribed anticancer medicines were 20% of the household capacity to pay. Data were analysed by using Statistical Packages for Social Sciences (IBM SPSS Statistics for Windows, V.21.0).

Results

A total of 5060 patients with cancer were approached out of which 4483 patients were included in the survey. Overall, 10 103 anticancer drugs were prescribed. Among them, 96.3% were non-biologics and 3.7% were biologics. Oncologists were reluctant to prescribe biologics due to high prices. 58.1% of non-biologics were affordable; whereas, the affordability of biologics was 3.3%. A total of 43.9% of both biologic and non-biologic OBs were available; whereas, their affordability was 44.2%. On the other hand, the availability of LPGs was 21.3%, and their affordability was 66.1%. For low-income patients, the affordability of non-biologics was 31.6% and the affordability of biologics was 1.1%.

Conclusions

Most of the patients with cancer were prescribed non-biologics due to their low price and better affordability. In contrast to OBs, LPGs of both biologics and non-biologics had less availability but more affordability.
Cost-effectiveness analysis of internet-mediated cognitive behavioural therapy for depression in the primary care setting: results based on a controlled trial
Authors: Holst Anna , Björkelund Cecilia , Metsini Alexandra , Madsen Jens-Henrik , Hange Dominique , Petersson Eva-Lisa L , Eriksson Maria CM , Kivi Marie , Andersson Per-Åke Å , Svensson Mikael
Published: June 2018

Objective

To perform a cost-effectiveness analysis of a randomised controlled trial of internet-mediated cognitive behavioural therapy (ICBT) compared with treatment as usual (TaU) for patients with mild to moderate depression in the Swedish primary care setting. In particular, the objective was to assess from a healthcare and societal perspective the incremental cost-effectiveness ratio (ICER) of ICBT versus TaU at 12 months follow-up.

Design

A cost-effectiveness analysis alongside a pragmatic effectiveness trial.

Setting

Sixteen primary care centres (PCCs) in south-west Sweden.

Participants

Ninety patients diagnosed with mild to moderate depression at the PCCs.

Main outcome measure

ICERs calculated as (CostICBT−CostTaU)/(Health outcomeICBT−Health outcomeTaU)=ΔCost/ΔHealth outcomes, the health outcomes being changes in the Beck Depression Inventory-II (BDI-II) score and quality-adjusted life-years (QALYs).

Results

The total cost per patient for ICBT was 4044 Swedish kronor (SEK) (€426) (healthcare perspective) and SEK47 679 (€5028) (societal perspective). The total cost per patient for TaU was SEK4434 (€468) and SEK50 343 (€5308). In both groups, the largest cost was associated with productivity loss. The differences in cost per patient were not statistically significant. The mean reduction in BDI-II score was 13.4 and 13.8 units in the ICBT and TaU groups, respectively. The mean QALYs per patient was 0.74 and 0.79 in the ICBT and TaU groups, respectively. The differences in BDI-II score reduction and mean QALYs were not statistically significant. The uncertainty of the study estimates when assessed by bootstrapping indicated that no firm conclusion could be drawn as to whether ICBT treatment compared with TaU was the most cost-effective use of resources.

Conclusions

ICBT was regarded to be as cost-effective as TaU as costs, health outcomes and cost-effectiveness were similar for ICBT and TaU, both from a healthcare and societal perspective.

Trial registration number

ID NR 30511.