bluuebunny/crossref_metadata_2025 huggingface dataset:
Results on the approximate controllability of fractional hemivariational inequalities of order $1< r<2$
Authors: Mohan Raja M. , Vijayakumar V. , Huynh Le Nhat , Udhayakumar R. , Nisar Kottakkaran Sooppy
Published: May 2021

In this paper, we investigate the approximate controllability of fractional evolution inclusions with hemivariational inequalities of order$1< r<2$1<r<2. The main results of this paper are verified by using the fractional theories, multivalued analysis, cosine families, and fixed-point approach. At first, we discuss the existence of the mild solution for the class of fractional systems. After that, we establish the approximate controllability of linear and semilinear control systems. Finally, an application is presented to illustrate our theoretical results.
A new conformable nabla derivative and its application on arbitrary time scales
Authors: Segi Rahmat Mohamad Rafi , Noorani M. Salmi M.
Published: May 2021

In this article, we introduce a new type of conformable derivative and integral which involve the time scale power function $\widehat{\mathcal{G}}_{\eta }(t, a)$

G
ˆ

η

(
t
,
a
)
for $t,a\in \mathbb{T}$
t
,
a
∈
T
. The time scale power function takes the form $(t-a)^{\eta }$

(
t
−
a
)

η

for $\mathbb{T}=\mathbb{R}$
T
=
R
which reduces to the definition of conformable fractional derivative defined by Khalil et al. (2014). For the discrete time scales, it is completely novel, where the power function takes the form $(t-a)^{(\eta )}$

(
t
−
a
)

(
η
)

which is an increasing factorial function suitable for discrete time scales analysis. We introduce a new conformable exponential function and study its properties. Finally, we consider the conformable dynamic equation of the form $\bigtriangledown _{a}^{\gamma }y(t)=y(t, f(t))$

▽
a
γ

y
(
t
)
=
y
(
t
,
f
(
t
)
)
, and study the existence and uniqueness of the solution. As an application, we show that the conformable exponential function is the unique solution to the given dynamic equation. We also examine the analogue of Gronwall’s inequality and its application on time scales.
On nontrivial solutions of nonlinear Schrödinger equations with sign-changing potential
Authors: Chen Wei , Wu Yue , Jhang Seongtae
Published: May 2021

In this paper, we consider the superlinear Schrödinger equation with bounded potential well. The potential here is allowed to be sign-changing. Without assuming the Ambrosetti–Rabinowitz-type condition, we prove the existence of a nontrivial solution and multiplicity results.
Dynamics of a stochastic COVID-19 epidemic model with jump-diffusion
Authors: Tesfay Almaz , Saeed Tareq , Zeb Anwar , Tesfay Daniel , Khalaf Anas , Brannan James
Published: May 2021

For a stochastic COVID-19 model with jump-diffusion, we prove the existence and uniqueness of the global positive solution. We also investigate some conditions for the extinction and persistence of the disease. We calculate the threshold of the stochastic epidemic system which determines the extinction or permanence of the disease at different intensities of the stochastic noises. This threshold is denoted byξwhich depends on white and jump noises. The effects of these noises on the dynamics of the model are studied. The numerical experiments show that the random perturbation introduced in the stochastic model suppresses disease outbreak as compared to its deterministic counterpart. In other words, the impact of the noises on the extinction and persistence is high. When the noise is large or small, our numerical findings show that COVID-19 vanishes from the population if$\xi <1$ξ<1; whereas the epidemic cannot go out of control if$\xi >1$ξ>1. From this, we observe that white noise and jump noise have a significant effect on the spread of COVID-19 infection, i.e., we can conclude that the stochastic model is more realistic than the deterministic one. Finally, to illustrate this phenomenon, we put some numerical simulations.
The global prevalence of fusidic acid resistance in clinical isolates of Staphylococcus aureus: a systematic review and meta-analysis
Authors: Hajikhani Bahareh , Goudarzi Mehdi , Kakavandi Sareh , Amini Sana , Zamani Samira , van Belkum Alex , Goudarzi Hossein , Dadashi Masoud
Published: May 2021

Background and aim

Staphylococcus aureus (S. aureus) is one of the most common pathogens causing nosocomial and community-acquired infections with high morbidity and mortality rates. Fusidic acid has been increasingly used for the treatment of infections due to methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The present study aimed to determine the precise prevalence of fusidic acid resistant MRSA (FRMRSA), fusidic acid resistant MSSA (FRMSSA), and total fusidic acid resistant S. aureus (FRSA) on a global scale.

Methods

Several international databases including Medline, Embase, and the Web of Sciences were searched (2000–2020) to discern studies addressing the prevalence of FRSA, FRMRSA, and FRMSSA. STATA (version14) software was used to interpret the data.

Results

Of the 1446 records identified from the databases, 215 studies fulfilled the eligibility criteria for the detection of FRSA (208 studies), FRMRSA (143 studies), and FRMSSA (71 studies). The analyses manifested that the global prevalence of FRSA, FRMRSA, and FRMSSA was 0.5%, 2.6% and 6.7%, respectively.

Conclusion

This meta-analysis describes an increasing incidence of FRSA, FRMSSA, and FRMRSA. These results indicate the need for prudent prescription of fusidic acid to stop or diminish the incidence of fusidic acid resistance as well as the development of strategies for monitoring the efficacy of fusidic acid use.
Environmental implications of soil erosion and sediment yield in Lake Hawassa watershed, south-central Ethiopia
Authors: Degife Arega , Worku Hailu , Gizaw Shumete
Published: May 2021

Background

Assessing soil erosion, sediment yield and sediment retention capacity of watersheds is one of the under-researched areas in watersheds of developing countries like Lake Hawassa watershed. The study examined soil erosion and sediment yield and their environmental implications in the Lake Hawassa watershed. The quantification and mapping were carried out using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. Data such as Land Use Land Cover (LULC), Digital Elevation Model (DEM), rainfall, soil, and management practice were used as input parameters.

Results

The empirical analysis confirmed that the watershed has a total soil loss of about 5.27 Mt annually. The mean annual erosion rate from the watershed was estimated to be 37 t ha−1 year−1. The estimated erosion rate was greater than the maximum tolerable erosion limit in Ethiopia (2–18 t ha−1 year−1). The total amount of sediment which was exported to the nearby streams and lakes in the watershed was estimated to be 1.6 t ha−1 year−1. The water bodies receive a total of 226,690.3 t of sediment annually. Although higher soil loss and sediment export per unit of area were estimated from the highest slope gradients, greater contributions to the total soil loss and sediment export were computed from slopes with 5–30% gradients. In terms of LULC, the highest contribution to the total soil loss was computed from cultivated land while the highest rate of soil loss per hectare was observed from bare land. Due to the existing vegetative cover, a total of 18.65 Mt (130.7 t ha−1 year−1) of sediment was retained. Vegetation-covered LULCs such as forest, woodland, shrubland, and agroforestry revealed the highest sediment retention capacity. As a result of the increased soil erosion and sediment yield in the watershed, the drying-out of a small lake and the rise in the water level of Lake Hawassa were identified.

Conclusion

Most of the soil loss and sediment yield were contributed by a small part of the watershed. Thus, the results underscore the urgent need for targeted soil and water conservation measures of various types to ensure the sustainability of the watershed resources.
Improved response of human gingival fibroblasts to titanium coated with micro-/nano-structured tantalum
Authors: Zhang Chu-nan , Zhou Lin-yi , Qian Shu-jiao , Gu Ying-xin , Shi Jun-yu , Lai Hong-chang
Published: May 2021

Objectives

This study aims to evaluate the ability of tantalum-coated titanium to improve human gingival fibroblasts’ adhesion, viability, proliferation, migration performance, and the potential molecular mechanisms.

Materials and methods

Titanium plates were divided into two groups: (1) no coating (Ti, control), (2) Tantalum-coated titanium (Ta-coated Ti). All samples were characterized by scanning electronic microscopy, surface roughness, and hydrophilicity. Fibroblasts’ performance were analyzed by attached cell number at 1 h, 4 h, and 24 h, morphology at 1 h and 4 h, viability at 1 day, 3 days, 5 days, and 7 days, recovery after wounding at 6 h, 12 h, and 24 h. RT-PCR, western blot were applied to detect attachment-related genes’ expression and protein synthesis at 4 h and 24 h. Student’s t test was used for statistical analysis.

Results

Tantalum-coated titanium demonstrates a layer of homogeneously distributed nano-grains with mean diameter of 25.98 (± 14.75) nm. It was found that after tantalum deposition, human gingival fibroblasts (HGFs) adhesion, viability, proliferation, and migration were promoted in comparison to the control group. An upregulated level of Integrin β1 and FAK signaling was also detected, which might be the underlying mechanism.

Conclusion

In the present study, adhesion, viability, proliferation, migration of human gingival fibroblasts are promoted on tantalum-coated titanium, upregulated integrin β1 and FAK might contribute to its superior performance, indicating tantalum coating can be applied in transmucosal part of dental implant.

Clinical significance

Tantalum deposition on titanium surfaces can promote human gingival fibroblast adhesion, accordingly forming a well-organized soft tissue sealing and may contribute to a successful osseointegration.
Polypharmacy-associated potential contraindications of drug prescriptions in patients with primary angle closure disease in a real-world setting
Authors: Tanaka Fumiaki , Shibatani Naoki , Fujita Kazumi , Ikesue Hiroaki , Yoshimizu Satoru , Muroi Nobuyuki , Kurimoto Yasuo , Hashida Tohru
Published: May 2021

Background

Primary angle closure disease (PACD) is a type of glaucoma in which the intraocular pressure (IOP) is increased because of the blockage of the anterior chamber angle. Medications contraindicated for patients with PACD, such as anticholinergics, cause mydriasis, and can elevate IOP. However, anticholinergics are currently contraindicated only for primary angle closure glaucoma (PACG) in Japanese package inserts. In this study, we investigated the prescription status of medications contraindicated for PACD, such as anticholinergics, in patients with PACD scheduled for eye surgeries.

Methods

Forty-three Japanese patients diagnosed with PACD at Kobe City Eye Hospital, Japan, and scheduled hospitalization for eye surgeries between December 2017 and July 2018, were included. Data, including sex, age, diagnosis, IOP, anterior chamber depth, and patients’ regular medications prior to hospitalization, were collected for each patient from the electronic medical records.

Results

The number of patients with chronic primary angle closure (CPAC) and acute primary angle closure (APAC) was 35 (81.4%) and 8 (18.6%), respectively. Among all the 43 patients with PACD, 8 (18.6%) received 15 medications that are potentially contraindicated for PACD by non-ophthalmologist. According to medication categories, benzodiazepine hypnotics were the most commonly prescribed. Among the 8 patients with APAC, 2 (25.0%) had routinely received medications contraindicated for PACD. The median number of all kinds of prescriptions on the day of hospitalization was significantly higher for patients who received medications contraindicated for PACD than for those who did not receive them (p = 0.010).

Conclusions

About 20% of patients with PACD received medications potentially contraindicated for PACD, such as anticholinergics. Attention should be paid to patients prescribed multiple drugs for adverse events, such as increase in intraocular pressure.
Feasibility assessment of an 8-week attention-based training programme in the management of chronic spontaneous urticaria
Authors: Ridge Katie , Conlon Niall , Hennessy Martina , Dunne Pádraic J.
Published: May 2021

Background

Chronic spontaneous urticaria is a common disorder that is poorly understood and frequently misdiagnosed. Psychological difficulties are a significant factor in dermatological diseases and may also aggravate symptom burden. Mind-body interventions are used as a complementary approach to alleviate symptoms in chronic diseases and may represent a valuable non-pharmacological approach in CSU.

Methods

We sought to develop and evaluate the feasibility of an 8-week attention-based training (ABT) programme, coupled to biofeedback technology for CSU. Through convergent interviews, we gathered information from individuals with urticaria about possible links between stress, mood and skin symptoms. Using these data, we recruited 12 participants to engage in an amended ABT programme for patients with CSU, comprising eight 90-min sessions held weekly. Participants completed psychometric measures and measures of urticaria symptomatology as assessed by the urticaria control test, prior to and after the intervention. Adherence to ABT practice was measured using individual inner balance devices which tracked heart rate variability. We completed qualitative interviews after the intervention to obtain feedback on participant experience of the programme.

Results

Participants with CSU described how their psychological wellbeing can be linked to skin symptoms, poor sleep and difficulty concentrating. An amended ABT programme was found to be an acceptable component of care in the management of CSU. Retention of participants in the programme was challenging with 33% participants dropping out of the programme. For those who did complete the programme, three participants exceeded weekly practice at week 8. A decrease in severity of urticaria symptomatology as measured by the urticaria control test was observed upon completion of the intervention. The most commonly cited barrier to implementation of the programme was the time commitment required.

Conclusions

Integrating an ABT programme into routine clinical care for CSU patients is feasible and was deemed acceptable and valuable by individuals who took part. Further formal evaluation of ABT for CSU including the analysis of biochemical parameters is required to determine its role in the management of this distressing condition.

Trial registration

This trial is registered with ISRCTN with study ID ISRCTN13672947. Registration took place on 22/09/2020 (retrospectively registered).
Predictors of contraceptive discontinuation among postpartum women in Arusha region, Tanzania
Authors: Mahande Michael J. , Sato Ryoko , Amour Caroline , Manongi Rachel , Farah Amina , Msuya Sia E. , Elewonibi Bilikisu , Shah Iqbal
Published: May 2021

Background

Postpartum contraceptive discontinuation refers to cessation of use following initiation after delivery within 1 year postpartum. Discontinuation of use has been associated with an increased unmet need for family planning that leads to high numbers of unwanted pregnancies, unsafe abortion or mistimed births. There is scant information about contraceptive discontinuation and its predictors among postpartum women in Tanzania. This study aimed to determine predictors of contraception discontinuation at 3, 6, 12 months postpartum among women of reproductive age in Arusha city and Meru district, Tanzania.

Methods

This was an analytical cross-sectional study which was conducted in two district of Arusha region (Arusha city and Meru district respectively). A multistage sampling technique was used to select 13 streets of the 3 wards in Arusha City and 2 wards in Meru District. A total of 474 women of reproductive age (WRAs) aged 16–44 years residing in the study areas were included in this analysis. Data analysis was performed using STATA version 15. Odds ratios (ORs) with 95% confidence interval (CI) for the factors associated with contraceptives discontinuation (at 3, 6 and 12 moths) were estimated in a multivariable logistic regression model.

Results

Overall, discontinuation rate for all methods at 3, 6, and 12 months postpartum was 11, 19 and 29% respectively. It was higher at 12 months for Lactational amenorrhea, male condoms and injectables (76, 50.5 and 36%, respectively). Women aged 40–44 years had lower odds of contraceptive discontinuation at 3 months as compare to those aged 16 to 19 years. Implants and pills users had also lower odds of contraceptive discontinuation compared to injectable users at 3, 6 and 12 months respectively.

Conclusion

Lactational amenorrhea, male condoms and injectables users had the highest rates of discontinuation. Women’s age and type of method discontinued were independently associated with postpartum contraceptive discontinuation. Addressing barriers to continue contraceptive use amongst younger women and knowledge on method attributes, including possible side-effects and how to manage complications is warranted.
Subfascial‐located contraceptive devices requiring surgical removal
Authors: Hellwinkel Justin E. , Konigsberg Matthew W. , Oviedo Johana , Castaño Paula M. , Kadiyala R. Kumar
Published: May 2021

Background

Subdermal etonogestrel implants are highly effective contraceptive methods. Despite standardization of insertion technique by the manufacturer, some implants are inadvertently placed too deeply within or below the plane of the biceps brachii fascia. Placement of these implants in a deep tissue plane results in more difficult removal, which is not always possible in the office setting. In rare cases, surgical removal by an upper extremity surgeon is warranted.

Case presentation

Here we present 6 cases of etonogestrel implants located in a subfascial plane requiring removal by an upper extremity surgeon. Implants were all localized with plain radiography and ultrasound prior to surgical removal. All cases had implants located in the subfascial plane and one was identified intramuscularly. The average age was 28 years (19–33) and BMI was 24.0 kg/m^2 (19.1–36.5), with the most common reason for removal being irregular bleeding. The majority of cases (5/6) were performed under monitored anesthesia care with local anesthetic and one case utilized regional anesthesia. All implants were surgically removed without complication.

Conclusions

Insertion of etonogestrel contraceptive implants deep to the biceps brachii fascia is a rare, but dangerous complication. Removal of these implants is not always successful in the office setting and referral to an upper extremity surgeon is necessary to avoid damage to delicate neurovascular structures for safe removal.
Isolation, self-blame and perceived invalidation in aid personnel: identifying humanitarian-specific distress using the PostAID/Q
Authors: McCormack Lynne , Douglas Heather , Joseph Stephen
Published: May 2021

Objective

Humanitarian-specific psychological distress following deployment can elude detection using contemporary measures of trauma-related stress. This study assesses the unidimensional structure and convergent validity of the Post-deployment Altruistic Identity Disruption Questionnaire (PostAID/Q), an 18-item questionnaire underpinned by the construct Altruistic Identity/Disruption (AI/AID).

Method

Humanitarian aid personnel (N=108) completed an online web survey, inclusive of the Moral Injury Questionnaire (MIQ), Posttraumatic Distress Disorder Checklist (PCL-5), Psychological Well-Being Posttraumatic Changes Questionnaire (PWB-PTCQ) and Social Provisions Scale (SPS).

Results

A confirmatory factor analysis suggested a single factor structure providing further support for the conception of AI/AID as a unidimensional construct. Convergent validity was demonstrated through (1) utility for predicting a posttraumatic stress disorder (PTSD) diagnosis assessed by the PCL-5, and (2) moral injury assessed by the MIQ. The PostAID/Q was further moderately and negatively associated with the availability of social support (assessed by the SPS) and lower self-reports of psychological well-being post trauma (assessed by the PWB-PCTQ). Finally, the PostAID/Q demonstrated evidence of incremental validity in predicting humanitarian specific psychological distress over and above the PCL-5. Specifically, the PostAID/Q predicted increased moral injury on the MIQ, and decreased psychological well-being post trauma.

Conclusions

The PostAID/Q can assist in identifying humanitarian specific psychological responses post deployment guiding support for personnel, over and above more traditional measures of posttraumatic stress.
Mechanical thrombectomy in patients with cervical artery dissection and stroke in the anterior or posterior circulation – a multicenter analysis from the German Stroke Registry
Authors:   for the GSR-ET investigators, Schlemm Ludwig , von Rennenberg Regina , Siebert Eberhard , Bohner Georg , Flottmann Fabian , Petzold Gabor C. , Thomalla Götz , Endres Matthias , Nolte Christian H.
Published: May 2021

Background

Cervical artery dissection (CAD) is a rare cause of acute ischemic stroke (AIS) with large vessel occlusion (LVO) and may constitute a challenge for mechanical thrombectomy (MT). We compared procedural characteristics, reperfusion rates, and clinical outcome in AIS patients undergoing MT with and without CAD.

Methods

We performed a pre-specified analysis of patients registered within the German Stroke Registry, a prospectively maintained multicenter registry of consecutive patients with AIS patients treated by MT. Procedural characteristics included time periods and additional application of medication.

Results

Of 2589 patients, 62 (2.4%) were diagnosed with CAD. CAD patients were younger, had lower rates of known vascular risk factors and larger baseline stroke volumes. MT in CAD patients took significantly longer (median [IQR] groin-puncture-to-flow restoration time: 98 [67–136] versus 70 [45–100] minutes;p < 0.001) and more often required use of intra-arterial medication (34.4% versus 15.6%;p < 0.001). Reperfusion success (modified Treatment in Cerebral Infarction score 2b-3: 85.2% versus 83.3%,p = 0.690) and favorable functional outcome after 3 months (modified Rankin Scale score ≤ 2: 70.9% versus 36.4%, adjustedp = 0.086) did not differ significantly between patients with and without CAD. The latter findings held true for both CAD in the anterior and posterior circulation.

Conclusion

CAD in AIS requiring MT is rare. MT in patients with CAD constitutes a particular procedural challenge, but still achieves favorable radiological and functional outcomes in most patients. Our data provide indirect evidence that MT is of clinical benefit in patients with AIS due to LVO and CAD.
Prognostication after intracerebral hemorrhage: a review
Authors: Witsch Jens , Siegerink Bob , Nolte Christian H. , Sprügel Maximilian , Steiner Thorsten , Endres Matthias , Huttner Hagen B.
Published: May 2021

Background

Approximately half of patients with spontaneous intracerebral hemorrhage (ICH) die within 1 year. Prognostication in this context is of great importance, to guide goals of care discussions, clinical decision-making, and risk stratification. However, available prognostic scores are hardly used in clinical practice. The purpose of this review article is to identify existing outcome prediction scores for spontaneous intracerebral hemorrhage (ICH) discuss their shortcomings, and to suggest how to create and validate more useful scores.

Main text

Through a literature review this article identifies existing ICH outcome prediction models. Using the Essen-ICH-score as an example, we demonstrate a complete score validation including discrimination, calibration and net benefit calculations. Score performance is illustrated in the Erlangen UKER-ICH-cohort (NCT03183167). We identified 19 prediction scores, half of which used mortality as endpoint, the remainder used disability, typically the dichotomized modified Rankin score assessed at variable time points after the index ICH. Complete score validation by our criteria was only available for the max-ICH score. Our validation of the Essen-ICH-score regarding prediction of unfavorable outcome showed good discrimination (area under the curve 0.87), fair calibration (calibration intercept 1.0, slope 0.84), and an overall net benefit of using the score as a decision tool. We discuss methodological pitfalls of prediction scores, e.g. the withdrawal of care (WOC) bias, physiological predictor variables that are often neglected by authors of clinical scores, and incomplete score validation. Future scores need to integrate new predictor variables, patient-reported outcome measures, and reduce the WOC bias. Validation needs to be standardized and thorough. Lastly, we discuss the integration of current ICH scoring systems in clinical practice with the awareness of their shortcomings.

Conclusion

Presently available prognostic scores for ICH do not fulfill essential quality standards. Novel prognostic scores need to be developed to inform the design of research studies and improve clinical care in patients with ICH.
Unroofing and argon mucosal remnant ablation of neonatal duodenal duplication cyst
Authors: Falchetti Diego , Dessanti Antonio , Falchetti Marcella , Strusi Gianpaolo
Published: May 2021

Background

Duodenal duplication cyst is an uncommon foregut malformation usually diagnosed at birth or during infancy. Differently from elsewhere, sited small bowel duplications cannot be removed with simple bowel resection, because of the proximity of the biliary and pancreatic ducts also possibly with abnormal course.

Case presentation

We report a duodenal duplication cyst in a newborn female requiring early surgery because of nutritional difficulties. The cyst was located adjoined to the second portion of the duodenum sharing part of its muscle wall with the bowel. It was treated by removal of all the esophytic cyst while the remaining mucosa on the common wall with the duodenum was ablated with argon plasma coagulation, preserving the bowel integrity. Early postoperative period was uneventful, and the child could be fed per os on the second day. Yearly follow-up was maintained until 16 years for the risk of recurrence and cancer change due to the incomplete excision. Clinic and echographic controls had always been stayed free from any sequelae.

Conclusions

Foregut duplications should be removed totally to prevent complications and the long-term risk of cancer, but a duodenal resection can be a harmful surgery in neonatal age. Duplication cysts that are impossible to remove totally can be treated by unroofing and argon plasma coagulation of mucosal surface remnants, avoiding the risks of major procedures also in newborns.
Science Identity among Latinx Students in the Biomedical Sciences: The Role of a Critical Race Theory–Informed Undergraduate Research Experience
Authors: Camacho Tissyana C. , Vasquez-Salgado Yolanda , Chavira Gabriela , Boyns David , Appelrouth Scott , Saetermoe Carrie , Khachikian Crist
Published: May 2021

This study investigates science identity and intention to pursue a science career among three groups of graduating Latinx biomedical majors. Students who participated in an undergraduate research program guided by critical race theory reported the highest levels of science identity and intention to pursue a science career at the end of college.
President's Page: Supercharging the future: Joint SEG–AAPG annual meetings signal new level of collaboration
Authors: Nessim Maurice
Published: May 2021

Applied geoscience is at a critical juncture as the world's environmental challenges and changing energy landscape bring fresh opportunities to embrace a broader, more complex, and interrelated scope. SEG's six strategic pillars — innovation, digitalization, preservation, collaboration, representation, and contribution — are focusing our Society on advancing our community's contribution amid these dynamics and the new dimensions of organizations that advance sciences and their practices.
Introduction to this special section: Seismic imaging below complex overburdens
Authors: Duveneck Eric , Kiehn Michael
Published: May 2021

Despite decades of technology development and experience, seismic imaging below complex overburdens, such as salt bodies, basalt flows, or shallow gas accumulations, remains a challenge. For successful imaging in such settings, a number of key elements need to be in place: the overburden complexity needs to be properly captured and represented in the subsurface model (acquisition/model building), the target below the complex overburden needs to be sufficiently well illuminated (acquisition), and, finally, the target needs to be properly imaged through the complex overburden (imaging algorithm). All of these elements are discussed in the papers collected in this special section, which consists of contributions that demonstrate recent technology developments as well as insightful case studies that show how the different elements come together to make a successful imaging project.
Full-waveform inversion for full-wavefield imaging: Decades in the making
Authors: Huang Rongxin , Zhang Zhigang , Wu Zedong , Wei Zhiyuan , Mei Jiawei , Wang Ping
Published: May 2021

Seismic imaging using full-wavefield data that includes primary reflections, transmitted waves, and their multiples has been the holy grail for generations of geophysicists. To be able to use the full-wavefield data effectively requires a forward-modeling process to generate full-wavefield data, an inversion scheme to minimize the difference between modeled and recorded data, and, more importantly, an accurate velocity model to correctly propagate and collapse energy of different wave modes. All of these elements have been embedded in the framework of full-waveform inversion (FWI) since it was proposed three decades ago. However, for a long time, the application of FWI did not find its way into the domain of full-wavefield imaging, mostly owing to the lack of data sets with good constraints to ensure the convergence of inversion, the required compute power to handle large data sets and extend the inversion frequency to the bandwidth needed for imaging, and, most significantly, stable FWI algorithms that could work with different data types in different geologic settings. Recently, with the advancement of high-performance computing and progress in FWI algorithms at tackling issues such as cycle skipping and amplitude mismatch, FWI has found success using different data types in a variety of geologic settings, providing some of the most accurate velocity models for generating significantly improved migration images. Here, we take a step further to modify the FWI workflow to output the subsurface image or reflectivity directly, potentially eliminating the need to go through the time-consuming conventional seismic imaging process that involves preprocessing, velocity model building, and migration. Compared with a conventional migration image, the reflectivity image directly output from FWI often provides additional structural information with better illumination and higher signal-to-noise ratio naturally as a result of many iterations of least-squares fitting of the full-wavefield data.
The impact of acquisition geometry on full-waveform inversion updates
Authors: Vigh Denes , Cheng Xin , Jiao Kun , Kang Wei , Brand Nolan
Published: May 2021

Full-waveform inversion (FWI) is a high-resolution model-building technique that uses the entire recorded seismic data content to build the earth model. Conventional FWI usually utilizes diving and refracted waves to update the low-wavenumber components of the velocity model. However, updates are often depth limited due to the limited offset range of the acquisition design. To extend conventional FWI beyond the limits imposed by using only transmitted energy, we must utilize the full acquired wavefield. Analyzing FWI kernels for a given geology and acquisition geometry can provide information on how to optimize the acquisition so that FWI is able to update the velocity model for targets as deep as basement level. Recent long-offset ocean-bottom node acquisition helped FWI succeed, but we would also like to be able to utilize the shorter-offset data from wide-azimuth data acquisitions to improve imaging of these data sets by developing the velocity field with FWI. FWI models are heading toward higher and higher wavenumbers, which allows us to extract pseudoreflectivity directly from the developed velocity model built with the acoustic full wavefield. This is an extremely early start to obtaining a depth image that one would usually produce in much later processing stages.
Shenzi OBN: An imaging step change
Authors: Mifflin Cheryl , Eddy Drew , Wray Brad , Zheng Lin , Chazalnoel Nicolas , Huang Rongxin
Published: May 2021

The story of seismic imaging over BHP's Shenzi Gulf of Mexico production field follows the history of offshore seismic imaging, from 2D to 3D narrow-azimuth streamer acquisition and to its leading the wide-azimuth movement with the Shenzi rich-azimuth (RAZ) survey. Each RAZ reprocessing project over the last 15 years applied the latest processing technology, culminating in hundreds of scenario tests to refine the salt model, but eventually the RAZ data reached a technical limit. A new ocean-bottom-node (OBN) survey acquired in 2020 has produced a step-change improvement over the legacy RAZ image. The uplift can be attributed to several factors. First, an OBN feasibility and survey design study demonstrated that a core of dense nodes combined with sparse nodes would improve the accuracy and resolution of the full-waveform inversion (FWI) solution. Second, the OBN data acquired following the survey design and employing FWI as the main model-building tool realized the predicted improvement. The result was a substantial change to the complex salt model, verified by a salt proximity survey as well as other salt markers, and improvement in imaging over the entire field. In addition to the improvement arising from a more accurate FWI velocity model, the steep-dip imaging also benefited from the new full-azimuth and long-offset data. However, the best steep-dip and fault imaging comes from the FWI image, a direct estimation of reflectivity from the FWI velocity. As the maximum frequency used by FWI moves toward the maximum frequency of the final reverse time migration (RTM), the FWI image approaches the resolution necessary to compete as the primary interpretation volume. Its subsalt illumination surpassed that of the RTM and even the least-squares RTM volumes. These imaging improvements are providing a new understanding of the faults and stratigraphic relationships of the field.
Integrated processing and interpretation to image and derisk a carbonate reservoir clouded by shallow gas — A case study from offshore Vietnam
Authors: Park Jaewoo , Hyslop Craig , Zhou Da , Srinivasan Arjun , Montoya Patricia , Carlo Debra , Lahey Mike , Burnett William A. , Wawrzynski Alecia , Ayeni Gboyega , Espegren William , Lazaratos Spyros , Phillips Brandon M. , Lê Trung Tâm , Mai Thanh Hà , Đỗ Văn Thanh , Nguyễn Đu'o'ng Trung , Đặng Thị Minh Huệ , Nguyễn Duy Anh
Published: May 2021

Carbonate reservoirs are increasingly becoming an important resource for hydrocarbon production because they contain the majority of remaining proven oil and gas reserves. In this context, carbonate reservoirs could represent new opportunities; however, there is still a lack of understanding of their subsurface status and characterization. Carbonate reservoirs are more difficult to evaluate than their siliciclastic counterparts because many aspects of carbonate rocks make their seismic image signature complex and difficult to interpret. Moreover, the presence of complex overburden such as shallow gas accumulation can exacerbate amplitude and phase fidelity at the reservoir, which introduces an additional imaging challenge. This makes field development of carbonate reservoirs extremely difficult because field development requires detailed delineation of characteristic karst features to avoid drilling hazards and sudden water breakthrough. In this paper, we demonstrate that a tight integration of signal processing, depth model building, and imaging, as well as near-real-time seismic interpretation feedback, is the key to success for imaging complex carbonate reservoirs with overburden challenges. Our findings show that such an integrated approach can result in a substantially better image, reduced depth uncertainty, and better delineation of karst and fractures. It can also aid in well placement and improve reservoir property modeling.
Prevalence of depressive symptoms and symptoms of post-traumatic stress disorder among newly arrived refugees and asylum seekers in Germany: systematic review and meta-analysis
Authors: Hoell Andreas , Kourmpeli Eirini , Salize Hans Joachim , Heinz Andreas , Padberg Frank , Habel Ute , Kamp-Becker Inge , Höhne Edgar , Böge Kerem , Bajbouj Malek
Published: May 2021

Background

In total numbers, Germany has faced the largest number of refugees and asylum seekers (RAS) in Europe in the past decade. Although a considerable proportion have experienced traumatic and stressful life events, there is no systematic review to date examining the prevalence of depressive symptoms and post-traumatic stress disorder (PTSD) symptoms in RAS in Germany.

Aims

To calculate the prevalence of depressive symptoms and PTSD symptoms in the general population of RAS living in Germany after the year 2000 and explore the impact of study- and participant-related characteristics on prevalence estimates.

Method

We systematically searched PubMed, CINAHL, PsycINFO, PSYNDEX, Academic Search Complete, Science Direct and Web of Science from January 2000 to May 2020 to identify articles reporting prevalence of depressive symptoms and PTSD in RAS in Germany (PROSPERO registration number: CRD42020182796).

Results

In total, 31 different surveys met inclusion criteria with 20 surveys reporting prevalence estimates of depressive symptoms and 25 surveys symptoms of PTSD. Based on screening tools, the pooled prevalence estimate of PTSD symptoms was 29.9% (95% CI 20.8–38.7%) and of depressive symptoms 39.8% (95% CI 29.8–50.1%). Heterogeneity was large within and between subgroups. In multivariate meta-regressions on depressive symptoms, heterogeneity was largely explained by survey period, length of field period and study quality.

Conclusions

Prevalence rates of depressive symptoms and PTSD symptoms in RAS are notably large. They exceed the prevalence in the general German population. As a result of high heterogeneity, however, pooled prevalence rates should be interpreted with caution.
Functional Disability Among Older Versus Younger Adults With Advanced Non–Small-Cell Lung Cancer
Authors: Presley Carolyn J. , Arrato Nicole A. , Janse Sarah , Shields Peter G. , Carbone David P. , Wong Melisa L. , Han Ling , Gill Thomas M. , Allore Heather G. , Andersen Barbara L.
Published: May 2021

PURPOSE:

To determine patient and disease characteristics associated with functional disability among adults with advanced non–small-cell lung cancer (NSCLC).

METHODS:

In a prospective cohort of participants newly diagnosed with advanced NSCLC and beginning systemic treatment, functional disability in usual activities, mobility, and self-care was measured using the EuroQol-5D-5L at baseline. Demographics, comorbidities, brain metastases, Eastern Cooperative Oncology Group performance status (ECOG PS), and psychologic variables (depression [Patient Health Questionnaire-9] and anxiety [Generalized Anxiety Disorder 7-item scale]) were captured. Patients were classified into two disability groups (none-slight or moderate-severe) on the basis of total functional status scores. Differences between disability groups were determined (chi-square and t tests). Associations between patient characteristics and baseline disability were assessed using logistic regression.

RESULTS:

Among 173 participants, mean age was 63.3 years, 56% were male, 83% had ECOG PS 0-1, and 41% had brain metastases. Baseline disability was present in 39% of participants, with patients having moderate to severe disability in usual activities (37.6%), mobility (26.6%), and self-care (5.2%). Depressive and/or anxiety symptoms ranged from none to severe (Patient Health Questionnaire 9-item scale M = 6.5, SD = 5.3). Depressive symptoms were the only characteristic associated with a higher odds of baseline disability (adjusted odds ratio [aOR]: 1.26; 95% CI, 1.15 to 1.38; P < .001). Participants with poorer ECOG PS (aOR: 4.64; 95% CI, 1.84 to 11.68; P = .001) and depressive symptoms (aOR: 1.15; 95% CI, 1.07 to 1.24; P < .001) had higher odds of moderate-severe mobility disability compared with the none-slight disability group.

CONCLUSION:

More than one third of all adults with advanced NSCLC have moderate-severe functional disability at baseline. Psychologic symptoms were significantly associated with moderate-severe baseline disability.
Impact of ALK Inhibitors in Patients With ALK-Rearranged Nonlung Solid Tumors
Authors: Takeyasu Yuki , Okuma Hitomi S. , Kojima Yuki , Nishikawa Tadaaki , Tanioka Maki , Sudo Kazuki , Shimoi Tatsunori , Noguchi Emi , Arakawa Ayumu , Mori Taisuke , Sunami Kuniko , Kubo Takashi , Kohno Takashi , Akihiko Yoshida , Yamamoto Noboru , Yonemori Kan
Published: May 2021

PURPOSE

Anaplastic lymphoma kinase ( ALK) rearrangement is a well-known driver oncogene in non–small-cell lung cancer and has also been identified in other types of tumors. However, there is limited evidence on the clinical response to ALK tyrosine kinase inhibitors (TKIs), such as alectinib and crizotinib, in rare tumors with ALK fusion. We evaluated the therapeutic effect of ALK-TKIs in rare ALK-rearranged tumors.

PATIENTS AND METHODS

Between April 2012 and April 2019, clinical outcomes and characteristics of patients with ALK-rearranged nonlung solid tumors who received ALK-TKIs (alectinib and/or crizotinib) outside of clinical trials were reviewed. Expression and/or rearrangement of ALK was evaluated by immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing. The tumor response was assessed according to RECIST (version 1.1). Progression-free survival was estimated from initial ALK-TKI initiation until progression.

RESULTS

We identified seven patients (inflammatory myofibroblastic tumors, n = 3; ALK-positive histiocytosis, n = 1; histiocytic sarcoma, n = 1; osteosarcoma, n = 1; and parotid adenocarcinoma, n = 1), with a median age of 17 years. Two rare ALK fusions, namely, CTNNA1-ALK and ITSN2-ALK, were identified. As initial ALK-TKI therapy, five patients received alectinib and two received crizotinib. The objective response rate for the initial ALK-TKI therapy was 85.7% (95% CI, 44 to 97), including two patients who received alectinib and achieved complete response. The median progression-free survival was 8.1 months (range, 1.7 to not estimable). There were no treatment interruptions or dose reductions because of adverse events caused by alectinib.

CONCLUSION

This study highlights the potential benefit of ALK-TKIs, especially alectinib, in patients with ALK-rearranged nonlung solid tumors.
Baseline Metabolomic Profile as Potential Biomarker for Weight Change After Roux-en-Y Gastric Bypass Surgery
Authors: Thaker Vidhu V , Deng Shuliang , Gorski Grzegorz , Vedantam Sailaja , Clish Clary , Salem Rany , Hirschhorn Joel N
Published: May 2021

Introduction: Weight loss surgery (WLS) has emerged as an effective treatment for severe obesity (BMI ≥ 40 kg/m2 in adults) and Type 2 diabetes (T2D). There is a wide spectrum of long-term response, both in weight change and resolution of T2D after WLS. Younger age at surgery, white race and the extent of weight loss prior to surgery are the known traits associated with favorable outcomes. The aim of this study was to investigate untargeted metabolite profile prior to surgery as a potential biomarker for long-term weight change response to WLS.

Methods: Latent class growth mixture modeling (LCGMM) was used to classify the longitudinal weight change trajectories in a cohort of individuals who underwent Roux-en-Y gastric bypass (RYGB). Untargeted metabolite profile was done on a 4-module Liquid Chromatography/ Mass Spectroscopy (LC-MS) platform on the pre-surgery fasting plasma samples from subjects with weight regain or sustained weight loss. Metabolite wide association studies followed by pathway analysis was undertaken using Mummichog and GSEA algorithms. Partial least-square discriminant analysis (PLS-DA), a supervised classification framework used for datasets with thousands of correlated variables and a small number of samples that performs variable selection and classification as a one-step procedure, was used to identify the informative features that defined the two groups.

Results: LCGMM identified 3-classes of weight change in a cohort of 1589 subjects who had undergone RYGB – a) typical trajectory with significant weight loss by 12 months with plateau at ~80% weight loss (n= 1357, 85.4%), b) sustained weight loss without plateau (SWL, n=116, 7.3%) c) weight regain (RGN, 116, 7.3%). Samples from 80 subjects each with RGN or SWL (age 42.5 ± 10 years, 55% F, Excess body weight 221 ± 40 lbs) were used for untargeted profiling of 37,570 metabolite features (564 known). After QC and adjusting for age, sex, race and fasting time, 1920 features (37 known) were associated with the weight category at nominal significance (p <0.05). Amongst the known metabolites, the pathways represented in RGN were amino acid metabolism, branched chain and other essential amino acids that have been previously identified as markers of insulin resistance and T2D, while those with SWL were from sphingolipid metabolism. Dimethylguanidino valeric acid, a marker of liver fat and predictor of T2D was higher in individuals with SWL. Pathway analysis of the known and unknown metabolites together revealed pathways in urea cycle, pyrimidine, glutamate, essential amino acids, and butyrate metabolism. Features identified by PLS-DA overlapped with these pathways.

Conclusions: Untargeted baseline metabolites may serve as predictive biomarkers for weight change after RYGB. Future work will focus on developing a metabolite risk score and replication in other cohorts.