bluuebunny/crossref_metadata_2025 huggingface dataset:
On critical points of quadratic low-rank matrix optimization problems
Authors: Uschmajew André , Vandereycken Bart
Published: March 2020

The absence of spurious local minima in certain nonconvex low-rank matrix recovery problems has been of recent interest in computer science, machine learning and compressed sensing since it explains the convergence of some low-rank optimization methods to global optima. One such example is low-rank matrix sensing under restricted isometry properties (RIPs). It can be formulated as a minimization problem for a quadratic function on the Riemannian manifold of low-rank matrices, with a positive semidefinite Riemannian Hessian that acts almost like an identity on low-rank matrices. In this work new estimates for singular values of local minima for such problems are given, which lead to improved bounds on RIP constants to ensure absence of nonoptimal local minima and sufficiently negative curvature at all other critical points. A geometric viewpoint is taken, which is inspired by the fact that the Euclidean distance function to a rank-$k$ matrix possesses no critical points on the corresponding embedded submanifold of rank-$k$ matrices except for the single global minimum.
Eremenko’s Conjecture for Functions with Real Zeros: The Role of the Minimum Modulus
Authors: Nicks D A , Rippon P J , Stallard G M
Published: March 2020

We consider the class of real transcendental entire functions $f$ of finite order with only real zeros and show that if the iterated minimum modulus tends to $\infty $, then the escaping set $I(\,f)$ of $f$ has the structure of a spider’s web, in which case Eremenko’s conjecture holds. This minimum modulus condition is much weaker than that used in previous work on Eremenko’s conjecture. For functions in this class, we analyse the possible behaviours of the iterated minimum modulus in relation to the order of the function $f$.
Translation efficiency affects the sequence-independent +1 ribosomal frameshifting by polyamines
Authors: Oguro Akihiro , Shigeta Tomoaki , Machida Kodai , Suzuki Tomoaki , Iwamoto Takeo , Matsufuji Senya , Imataka Hiroaki
Published: March 2020

Antizyme (AZ) interacts with ornithine decarboxylase, which catalyzes the first step of polyamine biosynthesis and recruits it to the proteasome for degradation. Synthesizing the functional AZ protein requires transition of the reading frame at the termination codon. This programmed +1 ribosomal frameshifting is induced by polyamines, but the molecular mechanism is still unknown. In this study, we explored the mechanism of polyamine-dependent +1 frameshifting using a human cell-free translation system. Unexpectedly, spermidine induced +1 frameshifting in the mutants replacing the termination codon at the shift site with a sense codon. Truncation experiments showed that +1 frameshifting occurred promiscuously in various positions of the AZ sequence. The probability of this sequence-independent +1 frameshifting increased in proportion to the length of the open reading frame. Furthermore, the +1 frameshifting was induced in some sequences other than the AZ gene in a polyamine-dependent manner. These findings suggest that polyamines have the potential to shift the reading frame in the +1 direction in any sequence. Finally, we showed that the probability of the sequence-independent +1 frameshifting by polyamines is likely inversely correlated with translation efficiency. Based on these results, we propose a model of the molecular mechanism for AZ +1 frameshifting.
Parental Behaviors, Emotions at Bedtime, and Sleep Disturbances in Children with Cancer
Authors: Kim Hyun , Zhou Eric S , Chevalier Lydia , Lun Phyllis , Davidson Ryan D , Pariseau Emily M , Long Kristin A
Published: March 2020

Background

Poor sleep is common for children during cancer treatment, but there is limited understanding of the nature of children’s sleep throughout the treatment trajectory. The current exploratory study used an explanatory sequential mixed method approach to examine quantitative associations among sleep problems in children with cancer, parental behavior, and children’s sleep hygiene, with follow-up qualitative characterizations of children’s sleep across cancer treatment stages.

Procedure

Eighty parents of children with cancer (aged 2–10 years; in active treatment, maintenance treatment, or off treatment) completed an online survey querying the child’s sleep quality (Sleep Disturbance Scale for Children—Disorders of Initiating and Maintaining Sleep subscale) and behaviors (Child Sleep Hygiene Scale) and sleep-related parenting behaviors (Parental Sleep Strategies). A subsample (n = 17 parents) participated in qualitative interviews to better characterize the processes of children’s sleep and parents’ sleep-related behaviors.

Results

Children’s sleep quality, sleep hygiene, or parental sleep strategies were not significantly different by cancer treatment groups. Greater sleep disturbance in children was associated with their parents’ tendency to accommodate the child’s bedtime requests. Qualitatively, cancer treatment-related anxiety in both children and parents influence the onset of these disruptive sleep behaviors.

Conclusion

Parents’ sleep-related behaviors affect children’s sleep during cancer treatment. Parents’ accommodation may start during active treatment to alleviate cancer-related challenges, and these behaviors may continue into maintenance therapy and off treatment to reinforce sleep disturbance. Behavioral interventions targeting unhelpful parental behaviors may improve sleep in children with cancer during and after cancer treatment.
Double-edged risk: unaccompanied minor refugees (UMRs) in Sweden and their search for safety
Authors: Horning Amber , Jordenö Sara V , Savoie Nicole
Published: March 2020

Many unaccompanied minor refugees (UMRs) arrived in Sweden with the mass exodus of refugees who fled to the EU in 2015. UMRs are individuals who are under 18 years of age, outside their country of origin and separated from legal care-givers (Separated Children in Europe Programme 2004). In 2016, Swedish public opinion of asylum seekers began to shift from sympathy to fear (Kärrman 2015; Herz 2018) and Sweden implemented policies restricting UMRs’ rights. It was at this pivotal moment that we interviewed UMRs in two youth asylum-centres in rural Sweden. We contextualized this analysis through our concept of ‘double-edged risk’—that is, being at risk despite being viewed as risky. Portrayals of risky refugees depict them as manipulative, and even predatory (Banks 2012). Many of these minors lacked agency from the inception of their journey to the EU to their waiting for their asylum decision. For instance, all of the UMRs in this study were forced by parents to leave and stated they would not have taken the journey had they known the dangers. Initially, we sought to understand how UMRs garnered agency in light of their ‘double-edged’ risk; however, the most salient theme that emerged was their search for safety. In order to attain safety, many of these UMRs resiliently relinquished agency. These findings demystify ideas of the ‘dangerous’ refugee and are useful for understanding UMRs’ plight for refuge in the EU and to improving policies that thwart UMRs’ development.
Large inguinoscrotal hernia containing ureter: reminder to General Surgeons
Authors: Beh Han N , Ongso Yuni F
Published: March 2020

Inguinal hernia is a common general surgery presentation. Large inguinoscrotal hernias can contain large bowel, omentum, small bowel, Meckel’s diverticulum but rarely ureter and bladder. Ultrasound can further clarify contents of inguinal hernia, and for this patient, it showed a cystic structure in the hernia contents. This was further investigated and found to be the left ureter with moderate to severe hydronephrosis. The patient underwent left inguinal hernia repair without any complication because of the anticipated anatomical anomaly. This case is to raise awareness that a simple inguinoscrotal hernia repair could be complicated by ureteric injury if not investigated thoroughly in the preoperative stage.
Penetrating thoracic injury from a bean bag round complicated by development of post-operative empyema
Authors: Guenther Timothy M , Gustafson Joshua D , Wozniak Curtis J , Zakaluzny Scott A , Utter Garth H
Published: March 2020

Bean bag guns were developed as a nonlethal means for law enforcement personnel to subdue individuals. The large surface area and lower velocities of the bean bag round theoretically result in transfer of most of the energy to the skin/subcutaneous tissue and minimize the likelihood of dermal penetration, thereby ‘stunning’ intended victims without causing injury to deeper structures. However, this technology has been associated with significant intra-abdominal and intrathoracic injuries, skin penetration and death. We present a 59-year-old man who sustained a penetrating thoracic injury from a bean bag gun. Although the bean bag was successfully removed, the patient developed a postoperative empyema requiring operative management. We discuss the unique aspects of thoracic trauma from bean bag ballistics as well as considerations in management of patients with this uncommon mechanism of injury.
On the FRB luminosity function – – II. Event rate density
Authors: Luo Rui , Men Yunpeng , Lee Kejia , Wang Weiyang , Lorimer D R , Zhang Bing
Published: March 2020

The luminosity function of Fast Radio Bursts (FRBs), defined as the event rate per unit cosmic co-moving volume per unit luminosity, may help to reveal the possible origins of FRBs and design the optimal searching strategy. With the Bayesian modelling, we measure the FRB luminosity function using 46 known FRBs. Our Bayesian framework self-consistently models the selection effects, including the survey sensitivity, the telescope beam response, and the electron distributions from Milky Way/ the host galaxy/ local environment of FRBs. Different from the previous companion paper, we pay attention to the FRB event rate density and model the event counts of FRB surveys based on the Poisson statistics. Assuming a Schechter luminosity function form, we infer (at the 95 per cent confidence level) that the characteristic FRB event rate density at the upper cut-off luminosity $L^*=2.9_{-1.7}^{+11.9}\times 10^{44}\, \mathrm{erg}\, \mathrm{s}^{-1}$ is $\phi ^*=339_{-313}^{+1074}\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$, the power-law index is $\alpha =-1.79_{-0.35}^{+0.31}$, and the lower cut-off luminosity is $L_0\le 9.1\times 10^{41}\, \mathrm{erg}\, \mathrm{s}^{-1}$. The event rate density of FRBs is found to be $3.5_{-2.4}^{+5.7}\times 10^4\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{42}\, \mathrm{erg}\, \mathrm{s}^{-1}$, $5.0_{-2.3}^{+3.2}\times 10^3\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{43}\, \mathrm{erg}\, \mathrm{s}^{-1}$ , and $3.7_{-2.0}^{+3.5}\times 10^2\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{44}\, \mathrm{erg}\, \mathrm{s}^{-1}$. As a result, we find that, for searches conducted at 1.4 GHz, the optimal diameter of single-dish radio telescopes to detect FRBs is 30–40 m. The possible astrophysical implications of the measured event rate density are also discussed in the current paper.
Newton versus the machine: solving the chaotic three-body problem using deep neural networks
Authors: Breen Philip G , Foley Christopher N , Boekholt Tjarda , Zwart Simon Portegies
Published: March 2020

Since its formulation by Sir Isaac Newton, the problem of solving the equations of motion for three bodies under their own gravitational force has remained practically unsolved. Currently, the solution for a given initialization can only be found by performing laborious iterative calculations that have unpredictable and potentially infinite computational cost, due to the system’s chaotic nature. We show that an ensemble of converged solutions for the planar chaotic three-body problem obtained using an arbitrarily precise numerical integrator can be used to train a deep artificial neural network (ANN) that, over a bounded time interval, provides accurate solutions at a fixed computational cost and up to 100 million times faster than the numerical integrator. In addition, we demonstrate the importance of training an ANN using converged solutions from an arbitrary precise integrator, relative to solutions computed by a conventional fixed precision integrator, which can introduce errors in the training data, due to numerical round-off and time discretization, that are learned by the ANN. Our results provide evidence that, for computationally challenging regions of phase space, a trained ANN can replace existing numerical solvers, enabling fast and scalable simulations of many-body systems to shed light on outstanding phenomena such as the formation of black hole binary systems or the origin of the core collapse in dense star clusters.
Phylogenetic Modeling of Regulatory Element Turnover Based on Epigenomic Data
Authors: Dukler Noah , Huang Yi-Fei , Siepel Adam
Published: March 2020

Evolutionary changes in gene expression are often driven by gains and losses of cis-regulatory elements (CREs). The dynamics of CRE evolution can be examined using multispecies epigenomic data, but so far such analyses have generally been descriptive and model-free. Here, we introduce a probabilistic modeling framework for the evolution of CREs that operates directly on raw chromatin immunoprecipitation and sequencing (ChIP-seq) data and fully considers the phylogenetic relationships among species. Our framework includes a phylogenetic hidden Markov model, called epiPhyloHMM, for identifying the locations of multiply aligned CREs, and a combined phylogenetic and generalized linear model, called phyloGLM, for accounting for the influence of a rich set of genomic features in describing their evolutionary dynamics. We apply these methods to previously published ChIP-seq data for the H3K4me3 and H3K27ac histone modifications in liver tissue from nine mammals. We find that enhancers are gained and lost during mammalian evolution at about twice the rate of promoters, and that turnover rates are negatively correlated with DNA sequence conservation, expression level, and tissue breadth, and positively correlated with distance from the transcription start site, consistent with previous findings. In addition, we find that the predicted dosage sensitivity of target genes positively correlates with DNA sequence constraint in CREs but not with turnover rates, perhaps owing to differences in the effect sizes of the relevant mutations. Altogether, our probabilistic modeling framework enables a variety of powerful new analyses.
Molecular architecture of the DNA-binding sites of the P-loop ATPases MipZ and ParA from Caulobacter crescentus
Authors: Corrales-Guerrero Laura , He Binbin , Refes Yacine , Panis Gaël , Bange Gert , Viollier Patrick H , Steinchen Wieland , Thanbichler Martin
Published: March 2020

The spatiotemporal regulation of chromosome segregation and cell division in Caulobacter crescentus is mediated by two different P-loop ATPases, ParA and MipZ. Both of these proteins form dynamic concentration gradients that control the positioning of regulatory targets within the cell. Their proper localization depends on their nucleotide-dependent cycling between a monomeric and a dimeric state and on the ability of the dimeric species to associate with the nucleoid. In this study, we use a combination of genetic screening, biochemical analysis and hydrogen/deuterium exchange mass spectrometry to comprehensively map the residues mediating the interactions of MipZ and ParA with DNA. We show that MipZ has non-specific DNA-binding activity that relies on an array of positively charged and hydrophobic residues lining both sides of the dimer interface. Extending our analysis to ParA, we find that the MipZ and ParA DNA-binding sites differ markedly in composition, although their relative positions on the dimer surface and their mode of DNA binding are conserved. In line with previous experimental work, bioinformatic analysis suggests that the same principles may apply to other members of the P-loop ATPase family. P-loop ATPases thus share common mechanistic features, although their functions have diverged considerably during the course of evolution.
Stereoelectroencephalography Versus Subdural Strip Electrode Implantations: Feasibility, Complications, and Outcomes in 500 Intracranial Monitoring Cases for Drug-Resistant Epilepsy
Authors: Joswig Holger , Lau Jonathan C , Abdallat Mahmoud , Parrent Andrew G , MacDougall Keith W , McLachlan Richard S , Burneo Jorge G , Steven David A
Published: March 2020

BACKGROUND

Both stereoelectroencephalography (SEEG) and subdural strip electrodes (SSE) are used for intracranial electroencephalographic recordings in the invasive investigation of patients with drug-resistant epilepsy.

OBJECTIVE

To compare SEEG and SSE with respect to feasibility, complications, and outcome in this single-center study.

METHODS

Patient characteristics, periprocedural parameters, complications, and outcome were acquired from a pro- and retrospectively managed databank to compare SEEG and SSE cases.

RESULTS

A total of 500 intracranial electroencephalographic monitoring cases in 450 patients were analyzed (145 SEEG and 355 SSE). Both groups were of similar age, gender distribution, and duration of epilepsy. Implantation of each SEEG electrode took 13.9 ± 7.6 min (20 ± 12 min for each SSE; P < .01). Radiation exposure to the patient was 4.3 ± 7.7 s to a dose area product of 14.6 ± 27.9 rad*cm2 for SEEG and 9.4 ± 8.9 s with 21 ± 22.4 rad*cm2 for SSE (P < .01). There was no difference in the length of stay (12.2 ± 7.2 and 12 ± 6.3 d). The complication rate was low in both groups. No infections were seen in SEEG cases (2.3% after SSE). The rate of hemorrhage was 2.8% for SEEG and 1.4% for SSE. Surgical outcome was similar.

CONCLUSION

SEEG allows targeting deeply situated foci with a non-inferior safety profile to SSE and seizure outcome comparable to SSE.
Old In Vitro Antimicrobial Breakpoints Are Misleading Stewardship Efforts, Delaying Adoption of Innovative Therapies, and Harming Patients
Authors: Ambrose Paul G , Bhavnani Sujata M , Andes David R , Bradley John S , Flamm Robert K , Pogue Jason M , Jones Ronald N
Published: March 2020

The current antimicrobial market and old (pre-2000) in vitro antimicrobial susceptibility test interpretative criteria (STIC) are not working properly. Malfunctioning susceptibility breakpoints and antimicrobial markets have serious implications for both patients (ie, from a safety and efficacy perspective) and antibiotic-focused pharmaceutical and biotechnology company economic viability. Poorly functioning STIC fail both patients and clinicians since they do not discriminate between likely effective and ineffective antimicrobial regimens. Poor economic viability fails patients and clinicians as it decreases the industry’s ability to develop antimicrobial agents that clinicians and patients urgently require now and in the future. Herein, we review how STIC for older antimicrobial agents were determined and how their correction can impact the perceived utility of old relative to new antimicrobial agents. Moreover, we describe the data and analysis needs to systematically reevaluate older STIC values. We call for professional infectious diseases societies, government agencies, and other consensus bodies interested in the appropriate use of antimicrobial agents to join an effort to systematically evaluate and, where warranted, correct STIC for all relevant antimicrobial agents. This effort will amplify the effects of other measures designed to increase appropriate antimicrobial use (ie, good antimicrobial stewardship), development, and regulation.
Principles of Supplemental Motor Area and Cingulate Tumor Resection With Asleep Trimodal Motor Mapping: 2-Dimensional Operative Video
Authors: Magill Stephen T , Rubio Roberto Rodriguez , Berger Mitchel S
Published: March 2020

Resection of intra-axial tumors adjacent to the motor pathways can lead to devastating deficits; however, with an appropriate mapping technique, it can be performed safely. We present the case of a 63-yr-old woman with a diffuse glioma centered in the left supplemental motor area (SMA) and extending throughout the cingulate gyrus. In the video, we demonstrate the principles developed by the senior author for trimodal motor mapping under general anesthesia. Trimodal motor mapping includes direct stimulation of the cortex with a strip electrode, use of the bipolar stimulator for cortical and subcortical mapping, and use of the monopolar stimulator for subcortical motor mapping. We highlight technical principles required to safely resect these tumors, including the key anatomic landmarks and approach to SMA/cingulate lesions, techniques for subpial dissection, and preservation of en passage vessels. Patients with SMA tumors will almost always have a deficit after SMA resection, but if motor pathways are preserved and can be stimulated to produce movement at the end of the case, then the deficit will almost always improve, as was the case with this patient. Initially, postoperatively, she was nonverbal and hemiplegic, but by postoperative day 7 she recovered her speech significantly, was naming three of three objects, and was moving her right side. By 6 wk postoperative, she was ambulating independently and had normal speech. This case demonstrates the principles and techniques necessary for achieving maximal safe resection of tumors adjacent to the motor pathways with the patient under general anesthesia.

The patient gave written informed consent for the surgical resection of her tumor and for the publication of this video.
Growth performance of Alexandrium catenella from the Chilean fjords under different environmental drivers: plasticity as a response to a highly variable environment
Authors: Paredes-Mella Javier , Varela Daniel , Fernández Pamela , Espinoza-González Oscar
Published: March 2020

Alexandrium catenella, the main species associated with harmful algal blooms, has progressively increased its distribution through one of the most extensive and highly variable fjord systems in the world. In order to understand this successful expansion, we evaluated the effects of different salinities, light intensity, temperatures, nitrogen (N) forms and nitrogen/phosphate (N:P) ratio levels on the growth performance, using clones isolated from different locations across its wide geographic distribution. Results showed that the growth responses were plastic and, in some cases, different reaction norms among clones were observed. Despite plasticity, the optimal growth of A. catenella (i.e. highest growth rate and highest maximal cells density) was reached within a narrow thermal range (12–15°C), while salinity (20–30 PSU) and light intensity (20–120 μmol m−2 s−1) ranges were wider. These results are partially consistent with the highest cell densities recorded in the field. Furthermore, optimal growth was reached using reduced forms of nitrogen (i.e. urea and NH4+) and in unbalanced N:P ratios (18:1 and 30:1). These characteristics likely allow A. catenella to grow in highly variable environmental conditions and might partly explain the recent expansion of this species.
Risks of solid cancers in elderly persons with osteoarthritis or ankylosing spondylitis
Authors: Ward Michael M , Alehashemi Sara
Published: March 2020

Objectives

Patients with osteoarthritis and ankylosing spondylitis have lower cancer-related mortality than the general population. We examined risks of solid cancers at 16 sites in elderly patients with knee or hip osteoarthritis (KHOA) or ankylosing spondylitis.

Methods

In this population-based retrospective cohort study, we used US Medicare data from 1999 to 2010 to identify cohorts of persons with KHOA or ankylosing spondylitis, and a general population group without either condition, who were followed through 2015. We compared cancer incidence among groups, adjusted for age, sex, race, socioeconomic characteristics, geographic region, smoking and comorbidities.

Results

We studied 2 701 782 beneficiaries with KHOA, 13 044 beneficiaries with ankylosing spondylitis, and 10 859 304 beneficiaries in the general population group. Beneficiaries with KHOA had lower risks of cancer of the oropharynx, oesophagus, stomach, colon/rectum, hepatobiliary tract, pancreas, larynx, lung, and ovary than the general population. However, beneficiaries with KHOA had higher risks of melanoma, renal cell cancer, and cancer of the bladder, breast, uterus and prostate. Associations were similar in ankylosing spondylitis, with lower risks of cancer of the oesophagus, stomach, and lung, and higher risks of melanoma, renal cell cancer, and cancer of the renal pelvis/ureter, bladder, breast, and prostate.

Conclusion

Lower risks of highly prevalent cancers, including colorectal and lung cancer, may explain lower cancer-related mortality in patients with KHOA or ankylosing spondylitis. Similarities in cancer risks between KHOA and AS implicate a common risk factor, possibly chronic NSAID use.
Monitoring in emotion regulation: behavioral decisions and neural consequences
Authors: Dorman Ilan Shirel , Shafir Roni , Birk Jeffrey L , Bonanno George A , Sheppes Gal
Published: March 2020

Monitoring and deciding how to adjust an active regulatory strategy in order to maximize adaptive outcomes is an integral element of emotion regulation, yet existing evidence remains scarce. Filling this gap, the present study examined core factors that determine behavioral regulatory monitoring decisions and the neuro-affective consequences of these decisions. Using a novel paradigm, the initial implementation of central downregulation strategies (distraction, reappraisal) and the emotional intensity (high, low) were manipulated, prior to making a behavioral decision to maintain the initial implemented strategy or switch from it. Neuro-affective consequences of these behavioral decisions were evaluated using the Late Positive Potential (LPP), an electro-cortical measure of regulatory success. Confirming predictions, initial implementation of reappraisal in high intensity and distraction in low intensity (Strategy × Intensity combinations that were established in prior studies as non-preferred by individuals), resulted in increased behavioral switching frequency. Neurally, we expected and found that in high (but not low) emotional intensity, where distraction was more effective than reappraisal, maintaining distraction (relative to switching to reappraisal) and switching to distraction (relative to maintaining reappraisal) resulted in larger LPP modulation. These findings suggest that monitoring decisions are consistent with previously established regulatory preferences and are associated with adaptive short-term neural consequences.
The influence of relationship closeness on default-mode network connectivity during social interactions
Authors: Fareri Dominic S , Smith David V , Delgado Mauricio R
Published: March 2020

Reciprocated trust plays a critical role in forming and maintaining relationships, and has consistently been shown to implicate neural circuits involved in reward-related processing and social cognition. Less is known about neural network connectivity during social interactions involving trust, however, particularly as a function of closeness between an investor and a trustee. We examined network reactivity and connectivity in participants who played an economic trust game with close friends, strangers and a computer. Network reactivity analyses showed enhanced activation of the default-mode network (DMN) to social relative to non-social outcomes. A novel network psychophysiological interaction (nPPI) analysis revealed enhanced connectivity between the DMN and the superior frontal gyrus and superior parietal lobule when experiencing reciprocated vs violated trust from friends relative to strangers. Such connectivity tracked with differences in self-reported social closeness with these partners. Interestingly, reactivity of the executive control network (ECN), involved in decision processes, demonstrated no social vs non-social preference, and ECN-ventral striatum connectivity did not track social closeness. Taken together, these novel findings suggest that DMN interacts with components of attention and control networks to signal the relative importance of positive experiences with close others vs strangers.
Beyond the Core: Who Has Larger Social Networks?
Authors: Hofstra Bas , Corten Rense , van Tubergen Frank
Published: March 2020

The sociological literature on social networks overwhelmingly considers the number of core social contacts. Social networks, however, reach far beyond this small number of social ties. We know little about individual variation in the size of such extended social networks. In this study, we move beyond core networks and explain individual variation in the extended social network size among youth. We use survey data of Dutch adolescents (N = 5,921) and use two state-of-the-art measurements to compute extended network sizes: network scale-up methods through Bayesian modeling and the observed number of contacts on Facebook. Among both measurements, we find that extended networks are larger among ethnic majority members, girls, and those who often engage in social foci. This highlights a crucial role for preferences and opportunity in the genesis of extended networks. Additionally, we find that differences between both network sizes (scale-up and Facebook) are smaller for girls and higher educated. We discuss the implications of these findings and suggest directions for future research.
Acculturating Into Nursing for Hispanic/Latinx Baccalaureate Nursing Students: A Secondary Data Analysis
Authors: Woodley Lisa K. , Lewallen Lynne P.
Published: March 2020

BACKGROUND

This is a secondary data analysis of an original study describing the lived experiences of Hispanic/Latinx nursing students as they acculturate into the profession of nursing.

METHOD

The original study described the experiences of 11 Hispanic/Latinx new graduates from three baccalaureate nursing programs in the southeastern United States. A secondary data analysis using a theoretical thematic analytical approach with data gathered in the original study was done to determine the utility of the theory of cultural marginality in understanding these student experiences.

RESULTS

Findings support aspects of the theory, including marginal living, cross-cultural conflict recognition, and adjustment responses of poise and integration. Personal and contextual influences also impact the acculturation process for these nursing students.

CONCLUSION

The theory of cultural marginality is valuable and provides important context for understanding the process that Hispanic/Latinx nursing students experience as they acculturate into nursing.
Clinical Effects of Early or Surgical Menopause
Authors: Kingsberg Sheryl A. , Larkin Lisa C. , Liu James H.
Published: March 2020

Increasing numbers of women experience early menopause due in part to surgical treatment for benign gynecologic disorders and the rise in risk-reducing bilateral salpingo-oophorectomy in women with BRCA mutations. Unfortunately, the adverse health consequences of early loss of ovarian function accelerate the menopausal state and affect multiple systems, including cardiovascular, neurologic, bone, and connective tissue, and affect quality of life owing to vasomotor symptoms, mood, sleep, and sexual function. Yet many clinicians and women remain reluctant to use hormone therapy because of the Women's Health Initiative's adverse findings, even though they are not applicable to women with early menopause. This review examines the effects of early menopause and highlights the critical role of hormone therapy in this population.
Resident Responses to a Wellness Survey and Significant Unreported Distress
Authors: Dow Margaret L. , Bove Erica , Morgan Helen K. , Woodland Mark B. , Winkel Abigail F.
Published: March 2020

Resident well-being is a significant issue affecting our future physicians' abilities to fulfill their potential in training and practice. In the 2017 Council on Resident Education in Obstetrics and Gynecology National Wellness Survey, residents identified many challenges to wellness and had the opportunity to provide free-text responses about these issues. Secondary analysis of these responses revealed clusters of symptoms associated with mood disorders, including high rates of reported anxiety and depression symptoms, and even suicidality. The prevalence of these self-reported symptoms underscores the importance of targeting wellness programming efforts, improving health care work environments, advancing access to care, and destigmatizing mental health concerns for our learners.
Cephalic Elevation Device for Second-Stage Cesarean Delivery
Authors: Lassey Sarah C. , Little Sarah E. , Saadeh Michael , Patton Nicole , Farber Michaela K. , Bateman Brian T. , Robinson Julian N.
Published: March 2020

OBJECTIVE:

A cephalic elevation device is an inflatable device that elevates the fetal head. We sought to evaluate whether such a device reduces time to delivery after hysterotomy and lowers morbidity in cesarean deliveries during the second stage of labor.

METHODS:

We conducted a double-blind randomized controlled trial among nulliparous, term women aged 18–50 years with vertex singleton pregnancies. Women were eligible if they were to undergo cesarean delivery in the second stage of labor. All participating women had the cephalic elevation device inserted by the delivering provider and were randomly allocated to inflation or noninflation of the device. Inflation was performed in a blinded fashion. The primary outcome was time from hysterotomy to delivery. A sample size of 30 per group (N=60 participants) was planned to detect a 50% decrease in time to delivery after hysterotomy with cephalic elevation device inflation.

RESULTS:

From January 2018 through July 2019, 60 women who underwent cesarean delivery in the second stage were randomized. Analysis was by intention to treat. Women in the inflation group were older (33 vs 30.5 years), but the groups were otherwise similar. In both groups, most women had a low-transverse hysterotomy (93%). The median time from hysterotomy to delivery was significantly shorter in the inflation group (31 vs 54 seconds; P<.01). There was no significant difference in neonatal outcomes.

CONCLUSION:

Use of the cephalic elevation device during second-stage cesarean delivery led to a 23-second reduction time from hysterotomy to delivery.

CLINICAL TRIAL REGISTRATION:

ClinicalTrials.gov, NCT03342508.

FUNDING SOURCE:

The cephalic elevation devices used in this study were donated by Safe Obstetrics Systems.
Management of hip fractures among elderly patients at Jordan University Hospital: A cross-sectional study
Authors: Alisi Mohammed S. , Al-Alajlouni Jihad , Hammad Yazan , Mousa Khaled , Elifranji Zuhdi , Alaqrabawi Ihab , Al-Saber Munther , Alsousi Ahmed , Elessi Khamis
Published: March 2020

Background:

This study compared the practice of elderly hip fractures management at Jordan University Hospital against the practice recommended by American Academy of Orthopaedic Surgeons (AAOS).

Methods:

Medical records between Oct 1, 2017, and Oct 31, 2018, were reviewed retrospectively. Inclusion criteria included patients over the age of 65 yr who were admitted from the emergency department. Patients excluded from the study were involved in motor vehicle accidents, had pathological fractures, or were transferred from other hospitals. One hundred and thirteen patients were included.

Results:

All patients received venous thromboembolism prophylaxis, and none had preoperative traction. Surgery was done within 48 hr in 83% (94/113) of patients. All patients with unstable femoral neck fractures underwent arthroplasty. Sliding hip screws were used in 93.5% (29/31) of stable intertrochanteric fractures, but cephalomedullary devices were used in 86.7% of unstable fractures (46 patients). Rehabilitation was done for a majority of patients. Unfortunately, preoperative regional analgesia was not used at all. Bipolar heads were used in a majority of hemiarthroplasty cases. A blood transfusion threshold of no higher than 8 g/dL was only followed in 16 cases. Only 23.9% of patients continued physical therapy at home. Fewer than one-third of the patients underwent nutritional assessment or support. Only 15 patients received a secondary mode of analgesia postoperatively. Vitamin D and calcium were prescribed for less than 50% of patients. Only 10.6% were evaluated for osteoporosis after fracture.

Conclusions:

Compliance with AAOS guidelines is reasonable, and it can be increased by following recommendations regarding: preoperative analgesia, femoral head type, blood transfusion threshold, home physical therapy, nutritional assessment, pain management, vitamin D and calcium supplementation, and osteoporosis treatment.

Level of Evidence:

Level III.
Indications and associated outcomes for platelet-rich plasma injections performed in an academic orthopaedic-specific hospital: A patient satisfaction survey
Authors: Melbourne Craig S. , Smith Conor A. , Patel Jaykumar , Platt Brooks , Cook James L.
Published: March 2020

Background:

Platelet-rich plasma (PRP) is an autologous biologic product that has become widely used in orthopaedic centers and at so-called “regenerative medicine” or “pain” clinics. Although food Drug Administration (FDA)-approved indications for use of PRP in orthopaedics are for applications in which it is mixed with autograft or allograft bone, attention and clinical research have focused on its off-label uses for treatment of osteoarthritis, musculotendinous disorders, or joint pain. The present study aimed to document indications for PRP used by orthopaedic surgery faculty in an academic orthopaedic-specific hospital between 2011 and 2016, characterize demographics of patients receiving these injections, and assess associated 1-year or greater outcomes for these patients.

Methods:

With institutional review board approval, this study retrospectively identified 148 patients with osteoarthritis, augmentation surgical treatments, tendon or ligament pathology, and sacroiliac joint pain as indications for PRP treatment.

Results:

For respondents (n=60), 78.3% (47 of 60) reported PRP-related improvement in symptoms, with mean duration of effect of 800 days and an overall level of satisfaction with their PRP treatment of 67.9% (range, 1-100%). Factors that negatively influenced successful outcomes in the present study included patient age older than 45 yr and use of leukocyte-rich PRP, while degree of improvement and return to full activity positively influenced patient satisfaction with PRP treatment.

Conclusions:

The results of the present study suggest that PRP can be used to treat a variety of musculoskeletal conditions commonly diagnosed at an academic orthopaedic-specific hospital, with expectations for 78% of patients reporting improvement and an overall patient satisfaction level of 68%.

Level of Evidence:

Level IV.
A Multicenter Trial Demonstrating Presence or Absence of Bacterial Contamination at the Screw-Bone Interface Owing to Absence or Presence of Pedicle Screw Guard, Respectively, During Spinal Fusion
Authors: Agarwal Aakash , Lin Boren , Agarwal Ashish G. , Elgafy Hossein , Schultz Christian , Agarwal Anand K. , Goel Vijay K. , Sigler Von , Karas Chris , Gidvani Sandeep , Wang Jeffrey C. , Anand Neel , Garfin Steve R.
Published: March 2020

Study Design:

A prospective multicenter study.

Objective:

The objective of this study was to assess bacterial contamination in current practices of pedicle screw handling and comparing it to a novel method of using an intraoperative, sterile implant guard for screws.

Summary of Background Data:

Postoperative infections occur at the higher end of 2%–13%, as cited in the literature, and are underestimated due to various reasons in such publications. Despite concerns associated with vancomycin application immediately before closure, it is theoretically impossible to irrigate the screw-bone interface postimplantation. Consequently, any contamination of pedicle screw before implantation is permanent, and has the potential to cause deep-bone infection, or hardware loosening due to encapsulation of biofilm between the bone and the screw. Therefore, continued vigilance and effective preventive measures should be undertaken if available.

Materials and Methods:

Two groups of presterile individually-packaged pedicle screws, one incased in a sterile, protective guard (group 1: G) and the other without such a guard (group 2: NG), 31 samples in each group were distributed over 28 spinal fusion surgeries at 5 independent hospitals groups. Each were loaded onto the insertion device by the scrub tech and left on the sterile table. Twenty minutes later, the lead surgeon who had just finished preparing the surgical site, handles the pedicle screw, to check the fit with the insertion device. Then, instead of implantation, it was transferred to a sterile container using fresh sterile gloves for bacterial analysis.

Results:

The standard unguarded pedicle screws presented bioburden in the range of 105 to 107 colonies forming units per screw, whereas the guarded pedicle screws showed no bioburden.

Conclusion:

Standard, current, handling of pedicle screws leads to bacterial contamination, which can be avoided if the screws are sterilely prepackaged with an intraoperative guard (preinstalled).
Analysis of the Change Patterns of Sagittal Alignment Values After Selective Thoracic Fusion in Lenke 1 Adolescent Idiopathic Scoliosis According to Preoperative Thoracic Kyphosis Status
Authors: Park Se-Jun , Lee Chong-Suh , Lee Kyung-Joon , Lee Ji-Woon , Park Jin-Sung
Published: March 2020

Study Design:

This was a retrospective study.

Objective:

The objective of this study was to demonstrate the different change patterns in reciprocal sagittal alignment values after selective thoracic fusion (STF) in Lenke type 1 adolescent idiopathic scoliosis (AIS) according to preoperative thoracic kyphosis (TK).

Summary of Background Data:

Several studies have found significant increase in TK after STF, while other studies have reported decrease in TK postoperatively. Similar inconclusive results on changes in lumbar lordosis (LL) have been reported, showing LL increase, decrease, or no change.

Materials and Methods:

Ninety-three patients presenting with Lenke type 1 AIS treated by posterior STF with a minimum follow-up of 2 years were included in this study. Using whole spine radiographs, sagittal parameters including TK, LL, and upper lumbar lordosis (ULL) were compared preoperatively and at the last follow-up between a hypokyphosis group (preoperative TK<20 degrees) and a normokyphosis group (preoperative TK≥20 degrees). Health-related quality of life (HRQOL) was assessed using scoliosis research society health-related quality of life-30 (SRS-30) and short from health survey-36 questionnaire at the last visit.

Results:

The mean follow-up duration was 74.9 months. In the hypokyphosis group (35 patients), TK, LL, and ULL statistically significantly increased after surgery by mean 7.7, 5.1, and 3.7 degrees (P<0.001, <0.001, and 0.001). In the normokyphosis group (58 patients), these parameters did not show significant changes after STF. Final TK was significantly lower in hypokyphosis group than that in the normokyphosis group (21.2 vs. 30.9 degrees, P<0.001) while final LL did not differ between 2 groups (52.4 vs. 54.6 degrees, P=0.194). HRQOL did not differ significantly between the 2 groups.

Conclusions:

After STF in Lenke 1 AIS, TK, and LL statistically significantly increased through an increase in the mean ULL in the hypokyphosis group while those mean values did not change in the normokyphosis group. Despite the final mean value of the TK in the hypokyphosis group increasing by 7.7 degrees, it was statistically significantly lower than the final mean TK value in the normokyphosis group which did not increase after STF surgery by posterior approach. However, HRQOL showed no significant difference between the 2 groups.
Kissorphin improves spatial memory and cognitive flexibility impairment induced by ethanol treatment in the Barnes maze task in rats
Authors: Gibula-Tarlowska Ewa , Kotlinska Jolanta H.
Published: March 2020

Acute and chronic ethanol intake, as well as ethanol withdrawal, exert learning disabilities. Of all the neurotransmitters in the brain, endogenous opioid peptides are thought to participate in ethanol effects. Kisspeptins, including kisspeptin-10, are peptides produced in the part of brain involved in the consolidation of memory and orientation. A new derivative of kisspeptin-10 is kissorphin (Tyr-Asn-Trp-Asn-Ser-Phe-NH2), a peptide with anti-opioid-activity. Hence, the aim of our study was to reveal whether kissorphin (1, 3, and 10 nmol, i.v.) was able to prevent or reverse learning deficits such as spatial memory retention and reversal learning induced by acute ethanol administration (1 × 1.75 g/kg., i.p.) and reversal learning induced by ethanol withdrawal (11–13 days from ‘binge-like’ ethanol input—5.0 g/kg, i.g. for 5 days) in the Barnes maze task in rats. Our study demonstrated that acute kissorphin administration prevented spatial memory (higher doses) impairments and attenuated reversal learning deficits induced by acute ethanol administration, although the reversal learning impairment may have been due to spatial learning impairments rather than cognitive flexibility impairments. Moreover, kissorphin given prior to first reversal learning trial for 3 consecutive days in the Barnes maze task during withdrawal from ‘binge-like’ ethanol administration, significantly attenuated cognitive flexibility impairment in the ethanol-withdrawal rats. In the acute and chronic ethanol experiments, kissorphin was the most effective at the dose of 10 nmol. In conclusion, the ethanol-induced spatial memory impairment may be reversed by pharmacological manipulation of the endogenous opioid system.
Two Cases of the Vascular Territory of a Single-pedicled Deep Inferior Epigastric Perforator Flap with a Vertical Midline Abdominal Scar
Authors: Morita Daiki , Numajiri Toshiaki , Nakamura Hiroko , Yamochi Ryo , Tsujiko Shoko , Sowa Yoshihiro , Moriguchi Yoshio
Published: March 2020

: The deep inferior epigastric perforator (DIEP) flap is becoming the gold standard for breast reconstruction using autologous tissue. If there are scars in the abdomen from previous surgery, it is necessary to judge the indication for using this flap carefully. Particularly in cases with vertical midline scars, the blood flow supply to the zone II can be compromised. Even when patients have a median abdominal scar, it has been reported that the blood flow can extend beyond the scar and reach several centimeters to about half of zone II. We performed breast reconstruction using DIEP flaps for 2 patients with vertical midline scars in the lower abdomen. Indocyanine green angiography was conducted intraoperatively to confirm the vascular territory with a single pedicle before cutting off the flap. One patient showed fluorescence contrast on the contralateral side across the midline scar. However, the fluorescence contrast was absent across the midline scar in the other patient. Based on this result, we investigated the possible vascular territory of a single pedicled DIEP flap in patients with vertical midline abdominal scars. We suggest that successful blood supply to zone II of a single-pedicled DIEP flap in a patient with a vertical midline abdominal scar is related to the location of the perforator and the property of the tissue in the midline near the perforator. However, because it is difficult to predict the vascular territory of a single pedicle before surgery, intraoperative evaluation using such techniques such as indocyanine green fluorescence imaging is important.