bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel reliability sensitivity analysis method based on directional sampling and Monte Carlo simulation
Authors: Zhang Xiaobo , Lu Zhenzhou , Cheng Kai , Wang Yanping
Published: February 2020

Local reliability sensitivity and global reliability sensitivity are required in reliability-based design optimization, since they can provide rich information including variable importance ranking and gradient information. However, traditional Monte Carlo simulation is inefficient for engineering application. A novel numerical simulation method based on Monte Carlo simulation and directional sampling is proposed to simultaneously estimate local reliability sensitivity and global reliability sensitivity. By suitable transformation, local reliability sensitivity and global reliability sensitivity can be estimated simultaneously as by-products of reliability analysis for Monte Carlo simulation method. The key is how to efficiently classify Monte Carlo simulation samples into two categories: failure samples and safety samples. Directional sampling method, a classical reliability analysis method, is more efficient than Monte Carlo simulation for reliability analysis. A novel strategy based on nearest Euclidean distance is proposed to approximately screen out failure samples from Monte Carlo simulation samples using directional sampling samples. In the proposed method, local reliability sensitivity and global reliability sensitivity are by-products of reliability analysis using the directional sampling method. Different from existing methods, the proposed method does not introduce hypotheses and does not require additional gradient information. The advantages of the Monte Carlo simulation and directional sampling are well integrated in the proposed method. The accuracy and the efficiency of the proposed method for local reliability sensitivity and global reliability sensitivity are demonstrated by four numerical examples and two engineering examples including the headless rivet and the wing box structure.
Prognosis of railway ballast degradation for turnouts using track-side accelerations
Authors: Barkhordari Pegah , Galeazzi Roberto , Blanke Mogens
Published: February 2020

Maintenance of railway turnouts is a major cost driver for any infrastructure manager, which performs it based on preventive or periodic policies to guarantee minimum downtime of the infrastructure. Ballast maintenance activities, such as tamping, are scheduled by thresholding indicators derived from track geometry data in agreement with European standards. Current industrial practice adopts the same procedures for the evaluation of track geometry degradation in open track and turnouts. This lack of specificity may determine unnecessary maintenance actions with detrimental effects to the turnout dynamical performance. By employing track-side measurements of track acceleration, a probabilistic method for turnout’s ballast quality monitoring was derived by Barkhordari et al. The paper further develops such monitoring system by establishing a mapping between its output and the standard indicator of track geometry quality used by infrastructure managers to schedule ballast maintenance. This results in a predictor of track geometry quality with variable prediction horizon that is functional to the railway infrastructure manager for the predictive planning of ballast maintenance.
The true axial shoulder projection: Diagnostic aid for acromioclavicular joint dislocation?
Authors: Jassim SS , Clough R , Yarashi T , Carlos A , Di Mascio L
Published: February 2020

Introduction

Acromioclavicular joint dislocations are common. Differentiating between horizontal and vertical instability is challenging, but possible to diagnose on axial radiographs. No clear consensus for axial radiograph parameters currently exists. We aim to establish a reproducible technique to assess whether an axial radiograph represents a true axial view of the shoulder.

Methods

One hundred CT scans of normal uninjured shoulders were examined using multiplanar reformatting to assess the distance between the anterior glenoid (reference line) and anterior-most aspect of the acromion in the axial plane. Measurements were repeated and performed by multiple observers to give of intra- and inter-observer reliability.

Results

The mean distance from the anterior acromion to the reference line was −2.6 mm (i.e. posteriorly placed) (SD = 5.8 mm, range −16.9–13.2 mm). Most (89%) of the measurements were between 9 and −9 mm to the reference line. Intra-observer reliability was high with Cronbach’s α measurement as 0.997. Inter-observer reliability gave a Cronbach’s α measurement of 0.959.

Conclusion

When the anterior aspect of the acromion lies within 10 mm either side of a line parallel to the scapula blade at the anterior aspect of the glenoid on an axial radiograph, it represents a true axial projection of the glenohumeral joint (GHJ). Level of evidence: IV, Case series
Improving the standard of care for patients with spondyloarthritis-related immune inflammatory conditions: results of a Delphi study and proposal for early detection
Authors: Coto Pablo , Riestra Sabino , Rozas Paloma , Señaris Ana , Queiro Rubén
Published: February 2020

Background:

Our objective was to provide consensus recommendations on the optimal management of the immune-mediated inflammatory diseases (IMIDs) seen in patients with spondyloarthritis (SpA) using a multidisciplinary approach, and to develop a simple tool to help earlier recognition and referral of coexisting IMIDs in patients who already have one type of IMID.

Methods:

A total of 28 experts in the multidisciplinary management of the SpA-associated IMIDs assessed two questionnaires: one with statements focused on the multidisciplinary management of IMIDs, and a second questionnaire focused on questions useful for early recognition and referral. Panelists assessed the statements with a 9-point ordinal scale (1 = strongly disagree, 9 = strongly agree) using a modified Delphi methodology.

Results:

Consensus was reached on 72 out of the 82 statements (87.8%). Panelists agreed that the multidisciplinary approach to IMIDs is not sufficiently developed. The creation of multidisciplinary IMID units might be necessary. These units might focus primarily on patients with two or more coexisting IMIDs, or on IMIDs that are especially complex from a diagnostic or therapeutic point of view. Specialists who attend to patients with IMIDs should perform a screening for other coexisting IMIDs. A simple tool to help earlier recognition and referral of coexisting IMIDs is proposed.

Conclusions:

There is a need to improve care for patients with SpA-associated IMIDs. We provide expert recommendations to guide the adoption of a multidisciplinary approach for these cases, and a simple tool that may be useful for earlier recognition of coexisting IMIDs.
Influence of high versus low readability level of written health information on self-efficacy: A randomized controlled study of the processing fluency effect
Authors: Okuhara Tsuyoshi , Ishikawa Hirono , Ueno Haruka , Okada Hiroko , Kato Mio , Kiuchi Takahiro
Published: February 2020

We investigated the relationship of processing fluency of written information about exercise to participants’ perceived interest, safety, self-efficacy, outcome expectation, and behavioral intention regarding the exercise. We randomly assigned 400 men and women aged 40–69 years to control or intervention conditions. Perceived self-efficacy of performing the exercise in the intervention group (i.e. easy to read) was significantly higher than that in the control group (i.e. difficult to read) ( p = 0.04). Easy-to-read written health information may be important not only for making written health information comprehensible but also for increasing readers’ self-efficacy for adopting health-related behaviors.
A meta-analysis of the medium- and long-term effects of laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass
Authors: Gu Lihu , Huang Xiaojing , Li Shengnan , Mao Danyi , Shen Zefeng , Khadaroo Parikshit Asutosh , Ng Derry Minyao , Chen Ping
Published: February 2020

Background

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are two representative bariatric surgeries. This study aimed to compare the effects of the LSG and LRYGB based on high-quality analysis and massive amount of data.

Methods

For this study databases of PubMed, Web of Science, EBSCO, Medline, and Cochrane Library were searched for articles published until January 2019 comparing the outcomes of LSG and LRYGB.

Results

This study included 28 articles. Overall, 9038 patients (4597, LSG group; 4441, LRYGB group) were included. The remission rate of type 2 diabetes mellitus (T2DM) in the LRYGB group was superior to that in the LSG group at the 3-years follow-up. Five-year follow-up results showed that LRYGB had an advantage over LSG for the percentage of excess weight loss and remission of T2DM, hypertension, dyslipidemia, and abnormally low-density lipoprotein.

Conclusions

In terms of the long-term effects of bariatric surgery, the effect of LRYGB was better than of LSG.
The effects of diagnosis-related groups payment on hospital healthcare in China: a systematic review
Authors: Zou Kun , Li Hong-Ying , Zhou Die , Liao Zai-Jun
Published: February 2020

Background

There has been a growing interest in using diagnosis-related groups (DRGs) payment to reimburse inpatient care worldwide. But its effects on healthcare and health outcomes are controversial, and the evidence from low- and middle- income countries (LMICs) is especially scarce. The objective of this study is to evaluate the effects of DRGs payment on healthcare and health outcomes in China.

Method

A systematic review was conducted. We searched literature databases of PubMed, Cochrane Library, EMBASE, Web of Science, Chinese National Knowledge Infrastructure and SinoMed for empirical studies examining the effects of DRGs payment on healthcare in mainland China. We performed a narrative synthesis of outcomes regarding expenditure, efficiency, quality and equity of healthcare, and assessed the quality of evidence.

Results

Twenty-three publications representing thirteen DRGs payment studies were included, including six controlled before after studies, two interrupted time series studies and five uncontrolled before-after studies. All studies compared DRGs payment to fee-for-service, with or without an overall budget, in settings of tertiary (7), secondary (7) and primary care (1). The involved participants varied from specific groups to all inpatients. DRGs payment mildly reduced the length of stay. Impairment of equity of healthcare was consistently reported, especially for patients exempted from DRGs payment, including: patient selection, cost-shifting and inferior quality of healthcare. However, findings on total expenditure, out of pocket payment (OOP) and quality of healthcare were inconsistent. The quality of the evidence was generally low or very low due to the study design and potential risk of bias of included studies.

Conclusion

DRGs payment may mildly improve the efficiency but impair the equity and quality of healthcare, especially for patients exempted from this payment scheme, and may cause up-coding of medical records. However, DRGs payment may or may not contain the total expenditure or OOP, depending on the components design of the payment. Policymakers should very carefully consider each component of DRGs payment design against policy goals. Well-designed randomised trials or comparative studies are warranted to consolidate the evidence of the effects of DRGs payment on healthcare and health outcomes in LMICs to inform policymaking.
Middle Triassic gastropods from the Besano Formation of Monte San Giorgio, Switzerland
Authors: Pieroni Vittorio , Furrer Heinz
Published: February 2020

For the first time gastropods from the Besano Formation (Anisian/Ladinian boundary) are documented. The material was collected from three different outcrops at Monte San Giorgio (Southern Alps, Ticino, Switzerland). The taxa here described are Worthenia (Humiliworthenia)? aff. microstriata, Frederikella cf. cancellata, ?Trachynerita sp., ?Omphaloptycha sp. 1 and ?Omphaloptycha sp. 2. They represent the best preserved specimens of a larger collection and document the presence in this formation of the clades Vetigastropoda, Neritimorpha and Caenogastropoda that were widespread on the Alpine Triassic carbonate platforms. True benthic molluscs are very rarely documented in the Besano Formation, which is interpreted as intra-platform basin sediments deposited in usually anoxic condition. Small and juvenile gastropods could have been lived as pseudoplankton attached to floating algae or as free-swimming veliger planktotrophic larval stages. Accumulations of larval specimens suggest unfavorable living conditions with prevailing disturbance in the planktic realm or mass mortality events. However, larger gastropods more probably were washed in with sediments disturbed by slumping and turbidite currents along the basin edge or storm activity across the platform of the time equivalent Middle San Salvatore Dolomite.
Loss of PI3 kinase association improves the sensitivity of secondary mutation of KIT to Imatinib
Authors: Zhu Guangrong , Shi Jun , Zhang Shaoting , Guo Yue , Huang Ling , Zhao Hui , Jiang Yideng , Sun Jianmin
Published: February 2020

Background

KIT mutations are the predominant driver mutations in gastrointestinal stromal tumors (GISTs), and targeted therapy against KIT has improved treatment outcome dramatically. However, gaining secondary mutation of KIT confers drug resistance of GISTs leading to treatment failure.

Results

In this study, we found that secondary mutation of KIT dramatically increases the ligand-independent activation of the receptor and their resistance to the often used KIT inhibitor Imatinib in the treatment of GISTs. PI3 kinase plays essential roles in the cell transformation mediated by the primary mutation of KIT. We found that loss of PI3 kinase association, but not the inhibition of the lipid kinase activity of PI3 kinase, inhibits the ligand-independent activation of secondary mutations of KIT, and increases their sensitivity to Imatinib, and loss of PI3 kinase association inhibits secondary mutations of KIT mediated cell survival and proliferation in vitro. The in vivo assay further showed that the growth of tumors carrying secondary mutations of KIT is more sensitive to Imatinib when PI3 kinase association is blocked while inhibition of the lipid kinase activity of PI3 kinase cannot inhibit tumor growth, indicating that PI3 kinase is important for the drug resistance of secondary mutation of KIT independent of the lipid kinase activity of PI3 kinase.

Conclusions

Our results suggested that PI3 kinase is necessary for the ligand-independent activation of secondary mutations of KIT, and loss of PI3 kinase association improves the sensitivity of secondary mutations to the targeted therapy independent of the lipid kinase activity of PI3 kinase.
Temporal trends in healthcare resource utilization and costs following acute myocardial infarction
Authors: Shiyovich Arthur , Gilutz Harel , Arbelle Jonathan Eli , Greenberg Dan , Plakht Ygal
Published: February 2020

Background

Acute myocardial infarction (AMI) is associated with greater utilization of healthcare resources and financial expenditure.

Objectives

To evaluate temporal trends in healthcare resource utilization and costs following AMI throughout 2003–2015.

Methods

AMI patients who survived the first year following hospitalization in a tertiary medical center (Soroka University Medical Center) throughout 2002–2012 were included and followed until 2015. Length of the in-hospital stay (LOS), emergency department (ED), primary care, outpatient consulting clinic visits and other ambulatory services, and their costs, were evaluated and compared annually over time.

Results

Overall 8047 patients qualified for the current study; mean age 65.0 (SD = 13.6) years, 30.3% women. During follow-up, LOS and the number of primary care visits has decreased significantly. However, ED and consultant visits as well as ambulatory-services utilization has increased. Total costs have decreased throughout this period. Multivariate analysis, adjusted for potential confounders, showed as significant trend of decrease in LOS and ambulatory-services utilization, yet an increase in ED visits with no change in total costs.

Conclusions

Despite a decline in utilization of most healthcare services throughout the investigated decade, healthcare expenditure has not changed. Further evaluation of the cost-effectiveness of long-term resource allocation following AMI is warranted. Nevertheless, we believe more intense ambulatory follow-up focusing on secondary prevention and early detection, as well as high-quality outpatient chest pain unit are warranted.
Changes in the clinical presentation and outcomes of patients treated for severe malaria in a referral French university intensive care unit from 2004 to 2017
Authors: Lebut Jordane , Mourvillier Bruno , Argy Nicolas , Dupuis Claire , Vinclair Camille , Radjou Aguila , de Montmollin Etienne , Sinnah Fabrice , Patrier Juliette , Le Bihan Clément , Magalahes Eric , Smonig Roland , Kendjo Eric , Thellier Marc , Ruckly Stéphane , Bouadma Lila , Wolff Michel , Sonneville Romain , Houzé Sandrine , Timsit Jean-François
Published: February 2020

Background

In France, the incidence of severe imported malaria cases increased since early 2000. Artesunate was available (temporarily use authorization) since mid-2011 in France and commonly used for severe malaria since early 2013. Thus, the study objectives were to describe the patients with severe imported malaria admitted in intensive care unit (ICU) and assess the changes in clinical presentation and outcomes before and after this date.

Methods

Retrospective observational single-center study in the infectious diseases ICU of a referral university hospital, conducted on patients admitted for severe imported malaria from 2004 to 2017. Demographic variables, severity scores, WHO’s severity criteria on admission, treatment, and ICU and hospital lengths of stay were collected. Patients’ characteristics and outcomes were compared between both periods. A poor outcome was defined as the composite endpoint of death, or requirement for vasopressors, invasive mechanical ventilation and/or renal replacement therapy.

Results

189 patients were included, 98 in 2004–2012 and 91 in 2013–2017, most often from West and Central African countries (96%). The number of WHO criteria for severe malaria was comparable in both groups, but SAPS II, SOFA and ICU length of stay were significantly higher in 2004–2012, while patients of African origin living in France were less frequent (p < 0.01). The outcome was poor for 41/98 cases in 2004–2012 and 12/91 cases in 2013–2017 (p < 0.01). The risk factors of poor outcome on the multivariate logistic regression were a neurological failure (adjusted odds ratio (adjOR = 3.23; 95% CI (1.03–10.08), p = 0.004), cardio-circulatory failure (adjOR = 9.92; 95% CI (2.34–42), p = <0.01) and creatinine blood levels > 265 µmol/L (adjOR = 10.76; 95% CI (3.17–36.53), p < 0.01). In the multivariate analysis, IV artesunate was not associated with a better outcome. Patients of African origin did not seem to have a better outcome than Caucasian patients or those from other origins (adjOR = 0.59; 95% CI (0.21–1.65), p = 0.31).

Conclusion

Patients with imported malaria admitted in ICU in 2013–2017 were less severely ill than those in 2004–2012. These trends could be partially explained by the increasing proportion of African patients visiting friends or relatives or living in endemic areas.
Dosing vitamin C in critically ill patients with special attention to renal replacement therapy: a narrative review
Authors: Honore Patrick M. , Spapen Herbert D. , Marik Paul , Boer Willem , Oudemans-van Straaten Heleen
Published: February 2020

Rationale/methods

The primary aim of the present contribution is to find a literature-based agreement on dose adjustments of vitamin C in critically ill patients undergoing renal replacement therapy (RRT).

Available data/study results

Critical illness is frequently accompanied by severe vitamin C deficiency. High-dose supplementation beneficially affects clinical outcome in small cohorts of patients with sepsis, burn injury, and trauma. There are no specific data on clinical outcomes in patients receiving renal replacement therapy (RRT). Vitamin C plasma concentrations in patients on RRT are comparable to critically ill patients not receiving RRT. Vitamin C is cleared from the circulation during RRT at a rate dependent on the plasma concentration, dose and duration of RRT. Sieving coefficient is about 1. While the dose of RRT is lower than normal renal function, tubular reabsorption is absent. Sparse evidence suggests that vitamin C dosing during continuous RRT should not exceed the dose administered to critically ill patients not receiving continuous RRT. Low plasma concentrations are expected during prolonged RRT because of persistent extracorporeal removal, absent renal reabsorption and enhanced metabolic loss due to circuit-induced oxidative stress. A dosage of twice 1 g vitamin C daily may be necessary to achieve normal plasma concentrations during RRT, but more studies are needed. There is no available evidence that high doses of vitamin C administered over a short period can induce oxalate stones or has pro-oxidant effects.

Conclusions

Supplementing vitamin C 1 g twice daily to critically ill patients has a solid pathophysiological rationale and a good safety profile. Patients on RRT probably need similar doses as critically ill patients not receiving RRT. Intravenous vitamin C in a dose of 2 g/day may be necessary to achieve normal plasma concentrations during RRT. However, data on dose adjustment of vitamin C during intermittent or chronic RRT are sparse and require more thorough pharmacokinetic and dose–response studies.
Prescription drug diversion, misuse, and abuse among people living with HIV: a scoping review protocol
Authors: Chibi Buyisile , Torres Neusa Fernanda , Mashamba-Thompson Tivani P.
Published: February 2020

Background

Prescription drugs are controlled medicines due to their potential risks of being diverted, misused, and abused. Since the introduction of antiretroviral (ARVs) drugs, HIV is currently regarded as a chronic condition. However, prescription drug diversion, misuse, and abuse might serve as one of the critical barriers for achieving optimal medication adherence among people living with HIV, thereby negatively impacting the HIV care mandate. The primary aim of this scoping review is to gather evidence on the prevalence, practices, risk factors, and motives associated with prescription drug diversion, misuse, and abuse, as well as the evidence on the association between prescription drug diversion, misuse, and abuse with antiretroviral treatment (ART) adherence.

Methods

This review will be guided by Arksey and O’Malley’s framework as well as recommendations by Levac et al. (Implement Sci 5:69, 2010). We will search the following databases for relevant literature meeting our eligibility criteria: PubMed, Google Scholar, EBSCOhost (Academic Search Complete, MEDLINE, and Newspaper Source), World Health Organization, Science Direct, and Open Access Theses and Dissertations. Studies published within the period of January 1996 to June 2019 are eligible. The included studies should report evidence on the prevalence, practices, risk factors, motives, or association between ART adherence and prescription drug diversion, misuse, and abuse. Thematic analysis will be applied to summarize the review findings.

Discussion

We anticipate finding a considerable number of research studies on prescription drug diversion, misuse, and abuse among people living with HIV. Our synthesis of this evidence base is intended to serve as guidance for future research studies. The study findings will be disseminated through the traditional academic platforms, such as peer-reviewed publications and presentations at relevant local and international conferences, symposiums, and seminars.

Systematic review registration

PROSPERO CRD42017074076
Net absorption and liver metabolism of amino acids and heat production of portal-drained viscera and liver in multiparous sows during transition and lactation
Authors: Hu Liang , Kristensen Niels Bastian , Che Lianqiang , Wu De , Theil Peter Kappel
Published: February 2020

Background

Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity. The objectives of the present study were to quantify amino acid (AA) fluxes and heat production across portal-drained viscera (PDV) and liver in multiparous sows during transition and lactation.

Methods

Eight second parity sows were fitted with indwelling catheters in the femoral artery and in the mesenteric, portal and hepatic veins. Eight hourly sets of blood samples were taken starting 0.5 h before feeding at − 10, − 3, + 3, and + 17 d in milk (DIM). Blood gases, plasma metabolites and apparent total tract digestibility (ATTD) of nutrients were measured.

Results

Feed intake, the ATTD of DM, energy, nitrogen, fat and crude fiber changed with DIM (P < 0.001). Except for Glu, O2, and urea, all net portal fluxes were positive, and all were affected by DIM (P < 0.05) and by sampling time (P < 0.01). Compared with pre partum levels, net portal uptake of AA was 3-63% lower at + 3 DIM but 40-100% higher at + 17 DIM. Net portal fluxes of AA peaked at 1.5 to 2.5 h after feeding except for Glu, and they were positively correlated with changes in sow feed intake across DIM. The net portal recovery was low for Met (49%), Thr (54%), and His (54%) and high for the remaining essential AA (63-69%) and none of them differed across DIM. Net hepatic uptake (i.e. hepatic oxidation) of Lys, Thr, Ile, Leu and Phe peaked at 0.5 to 2.5 h after feeding, whereas uptake of Trp, Val, and His was constant, while that of Met was close to zero.

Conclusion

The net portal recovery was substantially lower for Met, Thr, and His than the remaining essential AA. Hepatic AA oxidation peaks 0.5 to 2.5 h after feeding. The heat production in PDV and liver was approximately two-fold higher at peak lactation compared to other stages. The study suggests that lysine was the limiting AA in peak lactation but not in early lactation.
A community-driven and evidence-based approach to developing mental wellness strategies in First Nations: a program protocol
Authors: Morton Ninomiya Melody , George Ningwakwe , George Julie , Linklater Renee , Bull Julie , Plain Sara , Graham Kathryn , Bernards Sharon , Peach Laura , Stergiopoulos Vicky , Kurdyak Paul , McKinley Gerald , Donnelly Peter , Wells Samantha
Published: February 2020

Background

Mental health, substance use/addiction and violence (MSV) are important issues affecting the well-being of Indigenous People in Canada. This paper outlines the protocol for a research-to-action program called the Mental Wellness Program (MWP). The MWP aims to increase community capacity, promote relationship-building among communities, and close gaps in services through processes that place value on and supports Indigenous communities’ rights to self-determination and control. The MWP involves collecting and using local data to develop and implement community-specific mental wellness strategies in five First Nations in Ontario.

Methods

The MWP has four key phases. Phase 1 (data collection) includes a community-wide survey to understand MSV issues, service needs and community strengths; in-depth interviews with individuals with lived experiences with MSV issues to understand, health system strengths, service gaps and challenges, as well as individual and community resilience factors; and focus groups with service providers to improve understanding of system weaknesses and strengths in addressing MSV. Phase 2 (review and synthesis) involves analysis of results from these local data sources and knowledge-sharing events to identify a priority area for strategic development based on local strengths and need. Phase 3 (participatory action research approach) involves community members, including persons with lived experience, working with the community and local service providers to develop, implement, and evaluate the MWP to address the selected priority area. Phase 4 (share) is focused on developing and implementing effective knowledge-sharing initiatives. Guidelines and models for building the MWP are shared regionally and provincially through forums, webinars, and social media, as well as cross-community mentoring.

Discussion

MWP uses local community data to address MSV challenges by building on community supports and resilience factors. Drawing on local data and each community's system of formal and informal supports, the program includes sharing exemplary knowledge-to-action models and wellness strategies developed by and for First Nations people that can be used by other First Nations to identify shared wellness priorities in each community, and determine and execute next steps in addressing areas of main concern.
Morphological variation in Cynodon dactylon (L.) Pers., and its relationship with the environment along a longitudinal gradient
Authors: Wang Miaoli , Zhang Jingxue , Guo Zhipeng , Guan Yongzhuo , Qu Gen , Liu Jianyu , Guo Yuxia , Yan Xuebing
Published: February 2020

Background

Geographical variation in morphological traits may reflect evolutionary patterns of morphological adaptability along environmental gradients. Comprehensive information on longitudinal patterns of morphological trait variation is very meaningful to explore morphological diversity and evolutionary trends in widespread bermudagrass.

Methods

To explore the spatial patterns of morphological traits, we investigated 10 morphological traits of bermudagrass and 10 soil nutrient indexes and collected local climate data for 13 different regions from 119°E to 105°E along the latitude 34°N.

Results

Considerable variations in morphological traits were observed at different longitudes, and the variations in most of the evaluated traits within populations were lower than those among populations. All of the 13 different longitudinal sites were divided into three groups based on morphological traits by cluster analysis. The major sources of diversity at the different longitudes were leaf length of the erect shoot, leaf width of the erect shoot, and the internode lengths of the erect shoot and stolon as determined by principal component analysis. Pearson correlation analysis also indicated that longitude was significantly and negatively correlated with these traits as well. Mean average rainfall was significantly correlated with leaf length of the erect shoot and the internode lengths of the erect shoot and stolon, while mean average temperature was only significantly correlated with internode length of the erect shoots. Available sulfur was significantly correlated with internode length of the erect shoot, plant height, and reproductive branch height, while the exchangeable Ca was significantly correlated with internode lengths of the erect shoot and stolon. Soil pH was significantly correlated with the internode length of the stolon. Longitude is an important factor that affects morphological trait variation in wild bermudagrass, and the leaves of the erect shoot and the internode length enlarged significantly with the collection sites moving from east to west.

Conclusion

Different combinations and interactions of environmental factors (soil and climate) along a longitudinal gradient may have strong effects on one or more morphological traits of bermudagrass.
Effect of chronic kidney disease on outcomes of total joint arthroplasty: a meta-analysis
Authors: Kim Chang-Wan , Kim Hyun-Jung , Lee Chang-Rack , Wang Lih , Rhee Seung Joon
Published: February 2020

Background

This meta-analysis was conducted to evaluate the differences in preoperative comorbidities, postoperative mortality, the rate of periprosthetic joint infection (PJI), and revision rate after total joint arthroplasty (TJA) between patients with chronic kidney disease (CKD)(CKD group) and patients with normal kidney function (non-CKD group).

Methods

We searched MEDLINE, EMBASE, and the Cochrane Library for studies assessing the effect of CKD on TJA outcome. This meta-analysis included studies that (1) compared the outcomes of TJA between the CKD and non-CKD groups; (2) compared the outcomes of TJA based on CKD stage; and (3) evaluated the risk factors for morbidity or mortality after TJA. We compared the mortality, PJI, and revision rate between CKD and non-CKD groups, and between dialysis-dependent patients (dialysis group) and non-dialysis-dependent patients (non-dialysis group).

Results

Eighteen studies were included in this meta-analysis. In most studies that assessed preoperative comorbidities, the number and severity of preoperative comorbidities were reported to be higher in the CKD group than in the non-CKD group. The risk of mortality was found to be higher in the CKD and dialysis groups compared with the respective control groups. In the studies based on administrative data, the unadjusted odds ratio (OR) of PJI was significantly higher in the CKD group than in the non-CKD group; however, no significant difference between the groups was noted in the adjusted OR. After total hip arthroplasty (THA), the risk of PJI was higher in the dialysis group than in the non-dialysis group. No significant difference was noted between the groups in the rate of PJI following total knee arthroplasty. The revision rate did not significantly differ between the CKD and non-CKD groups in the studies that were based on administrative data. However, the unadjusted OR was significantly higher in the dialysis group than in the non-dialysis group.

Conclusions

Preoperative comorbidities and mortality risk were higher in the CKD and dialysis groups than in their respective control groups. The risk of revision was greater in the dialysis group than in the non-dialysis group, and the risk of PJI in the dialysis group became even greater after THA. Surgeons should perform careful preoperative risk stratification and optimization for patients with CKD scheduled to undergo TJA.
Optimal finite-difference operators for arbitrarily sampled data
Authors: Koene Erik F. M. , Robertsson Johan O. A.
Published: February 2020

We have developed a general method to obtain the equiripple and the least-squares finite-difference (FD) operator weights to compute arbitrary-order derivatives from arbitrary sample locations. The method is based on the complex-valued Remez exchange algorithm applied to three cost functions: the total error, the relative error, and the group-velocity error. We evaluate the method on three acoustic FD modeling examples. In the first example, we assess the accuracy obtained with the optimal coefficients when propagating acoustic waves through a medium. In the second example, we propagate a wave through an irregular grid. In the final example, we position a source and receiver at arbitrary locations in-between the modeling grid points. In the examples using regular grids, the equiripple solution to the relative cost function performs best. It obtains marginally (4%–10%) better results compared to the second-best option, the least-squares solution for the relative cost function. The least-squares solution for the relative error produced the only stable and accurate results also in the example of modeling on an irregular grid.
Automatic well tying and wavelet phase estimation with no waveform stretching or squeezing
Authors: Gelpi Gabriel R. , Pérez Daniel O. , Velis Danilo R.
Published: February 2020

Well-to-seismic tie and wavelet phase estimation are closely related steps that link geology and seismic data. Usually, these processes are solved separately or alternately, diminishing the quality of the well-tying procedure. Apart from trying different wavelets, the well-to-seismic tie involves shifting and, often, stretching and/or squeezing the synthetic data until the correlation with the observed trace is high. These operations, which are somewhat arbitrary and prone to human errors, may lead to unrealistic velocity models and undesired waveform deformations. The automatic tying method that we propose avoids these issues allowing us to simultaneously adjust the wavelet phase and the velocity log within a predefined tolerance. The problem is solved iteratively by perturbing the observed velocity log and the wavelet phase in a way that leads to an increase of the correlation coefficient between the seismic data and the synthetic seismogram. The velocity log is perturbed smoothly using a function defined by monotonic cubic splines, whereas the wavelet phase is assumed to be an unknown constant. We solve the resulting optimization problem by means of differential evolution, which allows us to have complete control over the allowable velocity changes and guarantees that the measured borehole observations are well-honored. By means of pseudosynthetic and field data examples, we found that our automatic well-to-seismic tying method leads to high correlation values between the synthetic and the observed traces, accurate wavelet phase estimations, and small departures from the observed velocity log. Because it is the time scale that is stretched and/or squeezed and not the synthetic trace itself, as opposed to other automatic and manual well-tying methods, the resulting trace preserves the wavelet shape, a feature that certainly improves seismic data interpretation.
Subspace method for solving large-scale equivalent layer and density mapping problems
Authors: Mendonça Carlos A.
Published: February 2020

The equivalent layer technique explores an intrinsic property of potential fields that any observed field at the ground surface can be reconstituted from a fictitious continuous distribution at an arbitrary flat surface that is indistinguishable from the field of the true sources. This continuous distribution can be represented by a set of discrete cells of known position and size but unknown physical property by solving a linear system, with size proportional to the number of data points measured. The density distribution at the equivalent layer carries information about the true sources because it is a scaled and downward-continued version of the field generated by the true sources at the level that the geophysical survey was undertaken. The computation of this downward-continued field is unstable, and an equivalent source evaluation is constrained by the intense computational demand required to solve the associated large linear system. A new formulation is developed to directly solve large-scale gravity equivalent layer problems using a subspace representation for the unknown density distribution. This subspace basis is constructed by applying the singular value decomposition to the matrix containing the gridded data set. A procedure to diminish (by two orders of magnitude) the number of forward model evaluations is introduced by exploring the symmetry of the gravity kernel and its evaluation on a regular mesh. The density distribution at the equivalent layer is used to outline the spatial distribution of contrasting underlying sources, to discriminate regions with predominant positive or negative density contrast, and to estimate the mass excess or deficiency for sources with positive or negative density contrast. This technique is applied to determine density models for the Carajás airborne gravity survey and to analyze density distributions associated with banded iron formations and structures of the Carajás Mineral Province, Brazil, providing mass estimates for specific geologic unities.
Analytic formulation for subsurface volumetric estimation
Authors: Yin Chuan , Thibodeaux Terry
Published: February 2020

We have developed an analytic formulation for quick and more accurate volumetric estimations of subsurface resource potential. Our formulation is conceptually based on a structurally conformable model built deterministically using known and interpreted reservoir properties from wells, such as net-to-gross, porosity, and hydrocarbon saturation, along with oil-water contact or lowest known oil depth and interpreted seismic top-of-pay depth horizon. We have evaluated an important function, the hydrocarbon pore capacity (HPC), which is a product of net-to-gross, porosity, and hydrocarbon saturation. HPC reflects the heterogeneity of key reservoir rock and fluid properties, particularly in the vertical direction. We calculated the total hydrocarbon pore volume directly from HPC and the top-of-pay horizon, without the explicit need for building a geologic model first. Our efficient solution form can preserve the vertical resolution of wireline logging with transparent parameterization and the least amount of averaging and upscaling. We also provided additional formulation for incorporating different HPC regimes for cases of multiple existing wells in the reservoir. We demonstrate the practical application of the formulation with a data example from a Cretaceous carbonate reservoir in the southern Gulf of Mexico offshore and with comparisons to other common approaches. In the application example, we determine that the most common approach of using single-average-values can underestimate the reserve upside by as much as 30%, whereas the stochastic modeling approach provided improved estimates when simulating porosity with a lognormal distribution and preserving the net-to-gross log in its original vertical resolution.
Near-salt perturbations of stresses and pore fluid pressures and their impacts on wellbore stability in the Kuqa depression of the Tarim Basin, China
Authors: Chang Cheng , Luo Gang , Wang Mingwen , Sun Yunqiang
Published: February 2020

Salt structures are highly associated with economic hydrocarbon reservoirs. However, drilling a wellbore near or through the salt is usually difficult because the near-salt stresses and pore fluid pressures are largely perturbed due to weaker mechanical strength of salt bodies than their surrounding sediments. We have developed a 2D plane-strain poroelastic finite-element model to simulate stresses and pore pressures in the horizontal-compression salt tectonic system, the Kuqa depression in the Tarim Basin, China, and we use the model results of stresses and pore pressures to calculate safe drilling mud weights on drilling in the salt basin. We found that in early stage of the transient process (close to the undrained condition), pore fluid overpressure occurs at salt convex due to additional compression, whereas underpressure occurs at salt concave due to additional extension within the minibasin. Horizontal effective stress decreases at salt concave (within the minibasin) but increases at salt convex; vertical effective stress varies oppositely to horizontal effective stress. In the final stage of the transient process (drained condition), overpressure has dissipated and pore pressure remains hydrostatic, and stress perturbations are similar to those from the static geomechanical model with elastic sediments: horizontal stress increases at salt convex but decreases at salt concave; vertical stress slightly increases at salt convex and concave. Our calculated safe drilling mud weights and their windows vary over time. Especially at the salt convex, the safe windows are relatively narrow in the early stage of the transient process but become wider in later stage because overpressure dissipates over time and this makes drilling easier. Our results indicate different perturbation patterns of stresses and pore pressures near different salt geometries in a horizontal-compression salt tectonic system, and provide insights into wellbore drilling design and safe drilling mud weights in the salt system.
Preoperative Disability in US Veterans
Authors: Sora Ali , Pyati Shreyas , Kuo Marissa , Schroeder Rebecca , Barbeito Atilio , Corcoran Cori , Raghunathan Karthik
Published: February 2020

Using the 12-item World Health Organization Disability Assessment Schedule (WHODAS-12), we measured the prevalence of disability in all eligible patients during a 4-month period who were presenting for preoperative evaluation at a US Veterans Affairs hospital. Overall disability was at least moderate in more than half of these patients (total n = 472 at Durham, NC). Two of the 6 WHODAS domains, “Getting Around” and “Participation in Society,” contributed most to the overall scores—25% and 20%, respectively. Further studies are needed to determine the impact of domain-specific disabilities on postoperative outcomes and to identify potential interventions to address these vulnerabilities.
TRBP–Dicer interaction may enhance HIV-1 TAR RNA translation via TAR RNA processing, repressing host-cell apoptosis
Authors: Komori Chiaki , Takahashi Tomoko , Nakano Yuko , Ui-Tei Kumiko
Published: February 2020

The transactivating response (TAR) RNA-binding protein (TRBP) has been identified as a double-stranded RNA (dsRNA)-binding protein, which associates with a stem-loop region known as the TAR element in human immunodeficiency virus-1 (HIV-1). However, TRBP is also known to be an enhancer of RNA silencing, interacting with Dicer, an enzyme that belongs to the RNase III family. Dicer cleaves long dsRNA into small dsRNA fragments called small interfering RNA or microRNA (miRNA) to mediate RNA silencing. During HIV-1 infection, TAR RNA-mediated translation is suppressed by the secondary structure of 5'UTR TAR RNA. However, TRBP binding to TAR RNA relieves its inhibitory action of translation and Dicer processes HIV-1 TAR RNA to generate TAR miRNA. However, whether the interaction between TRBP and Dicer is necessary for TAR RNA translation or TAR miRNA processing remains unclear. In this study, we constructed TRBP mutants that were unable to interact with Dicer by introducing mutations into amino acid residues necessary for the interaction. Furthermore, we established cell lines expressing such TRBP mutants. Then, we revealed that the TRBP–Dicer interaction is essential for both the TAR-containing RNA translation and the TAR miRNA processing in HIV-1.
Methods used to meta-analyse results from interrupted time series studies: A methodological systematic review protocol
Authors: Korevaar Elizabeth , Karahalios Amalia , Forbes Andrew B. , Turner Simon L. , McDonald Steve , Taljaard Monica , Grimshaw Jeremy M. , Cheng Allen C. , Bero Lisa , McKenzie Joanne E.
Published: February 2020

Background: Systematic reviews are used to inform healthcare decision making. In reviews that aim to examine the effects of organisational, policy change or public health interventions, or exposures, evidence from interrupted time series (ITS) studies may be included. A core component of many systematic reviews is meta-analysis, which is the statistical synthesis of results across studies. There is currently a lack of guidance informing the choice of meta-analysis methods for combining results from ITS studies, and there have been no studies examining the meta-analysis methods used in practice. This study therefore aims to describe current meta-analysis methods used in a cohort of reviews of ITS studies.

Methods: We will identify 100 reviews that include meta-analyses of ITS studies from a search of eight electronic databases covering several disciplines (public health, psychology, education, economics). Study selection will be undertaken independently by two authors. Data extraction will be undertaken by one author, and for a random sample of the reviews, two authors. From eligible reviews we will extract details at the review level including discipline and type of interruption; at the meta-analytic level we will extract type of outcome, effect measure(s), meta-analytic methods, and any methods used to re-analyse the individual ITS studies. Descriptive statistics will be used to summarise the data.

Conclusions: This review will describe the methods used to meta-analyse results from ITS studies. Results from this review will inform future methods research examining how different meta-analysis methods perform, and ultimately, the development of guidance.