bluuebunny/crossref_metadata_2025 huggingface dataset:
Burnout and resilience among Canadian palliative care physicians
Authors: Wang Cindy , Grassau Pamela , Lawlor Peter G. , Webber Colleen , Bush Shirley H. , Gagnon Bruno , Kabir Monisha , Spilg Edward G.
Published: November 2020

Background

Physicians experience high rates of burnout, which may negatively impact patient care. Palliative care is an emotionally demanding specialty with high burnout rates reported in previous studies from other countries. We aimed to estimate the prevalence of burnout and degree of resilience among Canadian palliative care physicians and examine their associations with demographic and workplace factors in a national survey.

Methods

Physician members of the Canadian Society of Palliative Care Physicians and Société Québécoise des Médecins de Soins Palliatifs were invited to participate in an electronic survey about their demographic and practice arrangements and complete the Maslach Burnout Inventory for Medical Professionals (MBI-HSS (MP)), and Connor-Davidson Resilience Scale (CD-RISC). The association of categorical demographic and practice variables was examined in relation to burnout status, as defined by MBI-HSS (MP) score. In addition to bivariable analyses, a multivariable logistic regression analysis, reporting odds ratios (OR), was conducted. Mean CD-RISC score differences were examined in multivariable linear regression analysis.

Results

One hundred sixty five members (29%) completed the survey. On the MBI-HSS (MP), 36.4% of respondents reported high emotional exhaustion (EE), 15.1% reported high depersonalization (DP), and 7.9% reported low personal accomplishment (PA). Overall, 38.2% of respondents reported a high degree of burnout, based on having high EE or high DP. Median CD-RISC resilience score was 74, which falls in the 25th percentile of normative population. Age over 60 (OR = 0.05; CI, 0.01–0.38), compared to age ≤ 40, was independently associated with lower burnout. Mean CD-RISC resilience scores were lower in association with the presence of high burnout than when burnout was low (67.5 ± 11.8 vs 77.4 ± 11.2, respectively, p < 0.0001). Increased mean CD-RISC score differences (higher resilience) of 7.77 (95% CI, 1.97–13.57), 5.54 (CI, 0.81–10.28), and 8.26 (CI, 1.96–14.57) occurred in association with age > 60 as compared to ≤40, a predominantly palliative care focussed practice, and > 60 h worked per week as compared to ≤40 h worked, respectively.

Conclusions

One in three Canadian palliative care physicians demonstrate a high degree of burnout. Burnout prevention may benefit from increasing resilience skills on an individual level while also implementing systematic workplace interventions across organizational levels.
Spontaneous regression of micro-metastases following primary tumor excision: a critical role for primary tumor secretome
Authors: Shaashua Lee , Eckerling Anabel , Israeli Boaz , Yanovich Gali , Rosenne Ella , Fichman-Horn Suzana , Ben Zvi Ido , Sorski Liat , Haldar Rita , Satchi-Fainaro Ronit , Geiger Tamar , Sloan Erica K. , Ben-Eliyahu Shamgar
Published: November 2020

Background

Numerous case studies have reported spontaneous regression of recognized metastases following primary tumor excision, but underlying mechanisms are elusive. Here, we present a model of regression and latency of metastases following primary tumor excision and identify potential underlying mechanisms.

Results

Using MDA-MB-231HM human breast cancer cells that express highly sensitive luciferase, we monitored early development stages of spontaneous metastases in BALB/c nu/nu mice. Removal of the primary tumor caused marked regression of micro-metastases, but not of larger metastases, and in vivo supplementation of tumor secretome diminished this regression, suggesting that primary tumor-secreted factors promote early metastatic growth. Correspondingly, MDA-MB-231HM-conditioned medium increased in vitro tumor proliferation and adhesion and reduced apoptosis. To identify specific mediating factors, cytokine array and proteomic analysis of MDA-MB-231HM secretome were conducted. The results identified significant enrichment of angiogenesis, growth factor binding and activity, focal adhesion, and metalloprotease and apoptosis regulation processes. Neutralization of MDA-MB-231HM-secreted key mediators of these processes, IL-8, PDGF-AA, Serpin E1 (PAI-1), and MIF, each antagonized secretome-induced proliferation. Moreover, their in vivo simultaneous blockade in the presence of the primary tumor arrested the development of micro-metastases. Interestingly, in the METABRIC cohort of breast cancer patients, elevated expression of Serpin E1, IL-8, or the four factors combined predicted poor survival.

Conclusions

These results demonstrate regression and latency of micro-metastases following primary tumor excision and a crucial role for primary tumor secretome in promoting early metastatic growth in MDA-MB-231HM xenografts. If generalized, such findings can suggest novel approaches to control micro-metastases and minimal residual disease.
Metastasis to lateral lymph nodes with no mesenteric lymph node involvement in low rectal cancer: a retrospective case series
Authors: Li Peng , Zhang Zhichun , Zhou Yuanda , Zeng Qingsheng , Zhang Xipeng , Sun Yi
Published: November 2020

Purpose

The aim of this study is to examine the pattern of lymph node metastasis (lateral vs. mesenteric lymph nodes) in low rectal cancer.

Methods

This retrospective analysis included all patients undergoing laparoscopic total mesorectal excision plus lateral lymph node dissection for advanced low rectal cancer (up to 8 cm from the anal verge) during a period from July 1, 2017, to August 31, 2019, at the Department of Colorectal Surgery, Tianjin Union Medical Center. The decision to conduct lateral lymph node dissection was based on positive findings in preoperative imaging assessments.

Results

A total of 42 patients were included in data analysis. Surgery was successfully completed as planned, without conversion to open surgery in any case. A minimum of 10 mesenteric lymph nodes and 1 lateral lymph node on each side were dissected in all patients. Pathologic examination of resected specimens showed no metastasis to either mesenteric or lateral lymph nodes in 7 (16.7%) case, metastasis to both mesenteric and lateral lymph nodes in 26 (61.9%) cases, metastasis to mesenteric but not lateral lymph nodes in 4 (9.5%) cases, and metastasis to lateral but not mesenteric lymph nodes in 5 (11.9%) cases (n = 2 in the obturator region; n = 3 in the iliac artery region).

Conclusion

A clinically significant proportion of low rectal cancer patients have metastasis to lateral lymph nodes without involvement of mesenteric lymph nodes. More carefully planned prospective studies are needed to verify this preliminary finding.
Air pollution as a contributor to the inflammatory activity of multiple sclerosis
Authors: Cortese Andrea , Lova Luca , Comoli Patrizia , Volpe Elisabetta , Villa Silvia , Mallucci Giulia , La Salvia Sabrina , Romani Alfredo , Franciotta Diego , Bollati Valentina , Basso Sabrina , Guido Ilaria , Quartuccio Giuseppe , Battistini Luca , Cereda Cristina , Bergamaschi Roberto
Published: November 2020

Objective

Air pollution has been recently identified as a risk factor for multiple sclerosis. Aim of this study was to investigate the immunological mechanism underlying the clinical association between air pollution, namely exposure to particulate matter 10 (PM10), and inflammatory activity of multiple sclerosis (MS)

Methods

Daily recording of PM10 was obtained by monitors depending on the residence of subjects. Expression of molecules involved in activation, adhesion, and migration of T lymphocytes were tested by flow cytometry in 57 MS patients and 19 healthy controls. We next assessed in vitro the effect of PM10 on expression of C-C chemokine receptors 6 (CCR6) by peripheral blood mononuclear cells (PBMCs), on cytokine production by monocyte-derived dendritic cells (mdDC), and on T cell polarization in PBMC/mdDC mixed cultures.

Results

We identified a significant correlation between mean PM10 levels and expression of CCR6 CD4+ T circulating cells in MS patients. This was paralleled by the observation in vitro of a higher level of CCR6 expression on PBMC following treatment with increased doses of particulate matter. Moreover, in mdDC cultures, particulate matter induced the secretion by mdDC of Th17 polarizing IL1 beta, IL6, and IL23 and, in mdDC/PBMC mixed cultures, enhanced generation of IL17-producing T cells.

Conclusions

Ex vivo and in vitro studies support the pro-inflammatory role of PM in MS, by upregulating expression of CCR6 on circulating CD4+ T cells and inducing in innate immune cells the production of Th17 polarizing cytokines. Therefore, we speculate that in MS respiratory exposure to PM10 may induce the production in the lung of autoreactive Th17 lymphocytes and boost their migratory properties through the blood-brain barrier.
Bilateral pulmonary embolism while receiving tranexamic acid: a case report
Authors: Ijaopo Ezekiel Oluwasayo , Ijaopo Ruth Oluwasolape , Adjei Sampson
Published: November 2020

Background

We present a case of a suspected tranexamic acid–related bilateral pulmonary embolism in a healthy and active middle-aged woman who was receiving tranexamic acid for menorrhagia with no other known significant risk factors for thromboembolism.

Case presentation

A 46-year-old Asian woman who was usually fit and well with no remarkable past medical history except for menorrhagia of 1-year duration for which she was receiving tranexamic acid presented to our accident and emergency department with a 2-week history of intermittent pleuritic central chest pain. She was reviewed and discharged to home with a diagnosis of musculoskeletal pain on two hospital visits because she had no significant risk factors for thromboembolism and her workup investigation results for pulmonary embolism and other differential diagnoses were largely unremarkable. On her third visit to the emergency ambulatory clinic with recurring symptoms of pleuritic chest pain, a pulmonary computed tomographic angiogram confirmed bilateral subsegmental pulmonary embolism.

Conclusion

This case report reinforces the possible increased risk of thromboembolism in patients receiving tranexamic acid.
The role of antifungals in the management of patients with severe asthma
Authors: Rapeport W. Garth , Ito Kazuhiro , Denning David W.
Published: November 2020

In patients with asthma, the inhalation of elevated amounts of fungal spores and hyphae may precipitate the onset of asthma or worsen control to the extent of being life-threatening. Sensitisation to fungi, especially Aspergillus fumigatus, is found in 15% to 48% of asthmatics in secondary care and is linked to worse asthma control, hospitalisation, bronchiectasis and fixed airflow obstruction, irrespective of whether allergic bronchopulmonary aspergillosis (ABPA) is diagnosed. ABPA represents a florid response to the presence of Aspergillus spp. but up to 70% of patients with severe asthma exhibit sensitisation to different fungi without meeting the diagnostic criteria for ABPA. The presence of persistent endobronchial colonisation with fungi, especially A. fumigatus, is linked to significantly higher rates of radiological abnormalities, lower post-bronchodilator FEV1 and significantly less reversibility to short acting bronchodilators. The therapeutic benefit for antifungal intervention in severe asthma is based on the assumption that reductions in airway fungal burden may result in improvements in asthma control, lung function and symptoms (especially cough). This contention is supported by several prospective studies which demonstrate the effectiveness of antifungals for the treatment of ABPA. Significantly, these studies confirm lower toxicity of treatment with azoles versus high dose oral corticosteroid dosing regimens for ABPA. Here we review recent evidence for the role of fungi in the progression of severe asthma and provide recommendations for the use of antifungal agents in patients with severe asthma, airways fungal infection (mycosis) and fungal colonisation. Documenting fungal airways colonisation and sensitisation in those with severe asthma opens up alternative therapy options of antifungal therapy, which may be particularly valuable in low resource settings.
Influence of maternal diet on offspring survivorship, growth, and reproduction in a sheetweb spider
Authors: Wen Lelei , Zhang Zengtao , Zhang Shichang , Liu Fengxiang , Jiao Xiaoguo , Li Daiqin
Published: November 2020

Prey vary dramatically in quality, and maternal diet is generally assumed to substantially influence offspring survivorship, growth, and reproduction in spiders. Numerous studies that have tested this hypothesis have focused exclusively on parental generation or have considered relatively few fitness components of juvenile offspring. However, maternal diet may have a substantial effect on fitness performance beyond juvenile offspring. Here, we investigated the influence of one-time maternal feeding on multiple offspring fitness components, including the survival rate and growth of juvenile offspring as well as the mating and reproductive success of adult offspring in Hylyphantes graminicola, a sheetweb spider with an extremely short lifespan (∼1 month). We fed field-collected adult female spiders two different diets only once immediately before oviposition: midges (Tendipes sp.) only (MO) or flies (Drosophila melanogaster) only (FO). Juvenile offspring of MO females had significantly higher survival rate, faster growth, and larger male size at maturity than FO offspring. Although maternal diet did not significantly influence mating behavior or fecundity of female offspring overall, those of MO females laid eggs earlier and their eggs also hatched earlier and had a higher hatching rate than those of FO females. Intriguingly, one-time maternal feeding was sufficient to have such an influence on offspring fitness even beyond juvenile offspring in H. graminicola. This one-time maternal effect may be widespread in other spiders and other invertebrates with a short lifespan.

This article has an associated First Person interview with the first author of the paper.
The RNA dependent DNA methylation pathway is required to restrict SPOROCYTELESS/NOZZLE expression to specify a single female germ cell precursor in Arabidopsis
Authors: Mendes Marta A. , Petrella Rosanna , Cucinotta Mara , Vignati Edoardo , Gatti Stefano , Pinto Sara C. , Bird Dayton C. , Gregis Veronica , Dickinson Hugh , Tucker Matthew R. , Colombo Lucia
Published: November 2020

In higher plants the female germline is formed from the megaspore mother cell (MMC), a single cell in the pre-meiotic ovule. Previously, it was reported that mutants in RNA dependent DNA methylation - RdDM - pathway might be involved in restricting female germline to a single nucellus cell. We show that the DRM methyltransferase double mutant drm1drm2 also presents also presents ectopic enlarged cells, consistent with supernumerary MMC-like cells. In wild-type ovules MMC differentiation required SPOROCYTELESS/NOZZLE (SPL/NZZ), as demonstrated by the spl/nzz mutant failing to develop an MMC. We address the poorly understood upstream regulation of SPL/NZZ in ovules, showing that the RdDM pathway is important to restrict SPL/NZZ expression. In ago9, rdr6 and drm1drm2 mutants, SPL/NZZ is ectopically expressed, suggesting that the mutiple MMC-like cells observed might be due to the ectopic expression of SPL/NZZ. We show that the ovule identity gene SEEDSTICK, directly regulates the AGO9 and RDR6 expression in the ovule and therefore indirectly SPL/NZZ expression. A model is presented describing the network required to restrict SPL/NZZ expression to specify a single MMC.
The Design of Tetradentate Ligands for Beryllium Encapsulation
Authors: Buchanan Jenna K , Plieger Paul G
Published: November 2020

Ligands which incorporate second-sphere intramolecular hydrogen bonding show potential for enhancing selectivity and binding strength for beryllium. In this highlight review, recent advances in the design of tetradentate ligands to selectively bind beryllium are discussed, as is the use of electrospray ionization mass spectrometry (ESI-MS) and 9Be nuclear magnetic resonance (NMR) spectroscopy as tools for the analysis of beryllium coordination compounds.
How Sleep Impacts Performance in Youth Athletes
Authors: Riederer Mark F.
Published: November 2020

Sleep is an important aspect in the recovery and performance in athletes. Recently, there has been increasing interest in exploring the various affects that sleep has on performance in athletes. Youth athletes represent a unique population in that not only do they have demands in training schedules and training load, but they also have demands in academics. There is a growing body of evidence to suggest that youth athletes do not get the recommended required amount of sleep and that this has negatively affected performance and well-being. The focus of this article is to review the most recent literature over the past year that investigates the impact of sleep on youth performance.
Ultrasound in Trauma and Other Acute Conditions in Sports, Part I
Authors: Hahn Marlee , Ray Jeremiah , Hall Mederic M. , Coe Ian , Situ-LaCasse Elaine , Waterbrook Anna L.
Published: November 2020

The utility of ultrasound in sports medicine is improving the sports medicine physician's ability to rapidly diagnose and treat a multitude of sports related pathologies. In this article, we clearly outline the current status of the evidence in support of using sports ultrasound in the setting of acute abdominal and thoracic trauma, acute lung illness, limited cardiac evaluation of a collapsed athlete, volume status assessment, and fracture evaluation.
A review of paediatric soft tissues masses referred to a tertiary musculoskeletal sarcoma centre
Authors: Reid Catriona , Saifuddin Asif
Published: November 2020

Objectives:

To determine the differential diagnosis of musculoskeletal soft tissue masses in children referred to a specialist musculoskeletal oncology unit.

Methods:

All children (0–18 y) referred to a specialist musculoskeletal oncology unit over a 20-month period (September 2018–May 2020) were retrospectively reviewed. Demographic data and referral diagnoses were obtained from the electronic patient notes. MRI findings and histopathological results were recorded. The comparison of non-neoplastic, benign neoplastic and malignant diagnoses at the point of referral and final diagnosis was determined.

Results:

116 patients were included, 60 (51.7%) males and 56 (48.3%) females with mean age of 10.6 years (3 months–18 years). 69 (59.5%) patients were referred with a suspected sarcoma, 29 (25.0%) with a suspected benign tumour and 18 (15.5%) with a non-neoplastic lesion. A diagnosis was achieved by histological assessment in 61 (52.6%) cases, microbiological assessment in 3 (2.6%) or clinical and imaging assessment in 52 (44.8%). 67 (57.8%) cases had non-neoplastic pathology, 39 (33.6%) a benign tumour, 4 (3.4%) an intermediate-grade tumour, 6 (5.2%) a malignant tumour.

Conclusions:

Although over half of children referred to a specialist musculoskeletal oncology unit were suspected of having a soft tissue sarcoma at referral, only 5.2% were diagnosed with a malignant tumour.

Advances in knowledge:

Approximately, 6 of 69 (8.7%) children referred to a specialist musculoskeletal oncology unit with a suspected soft tissue sarcoma will have a malignant lesion. Most paediatric soft tissue masses are non-neoplastic, the commonest diagnosis being a vascular malformation.
A funerary inscription of Chilbudius, magister militum per Thraciam?
Authors: KARDARAS George , CHARALAMPAKIS Pantelis
Published: November 2020

Επιτύμβια επιγραφή του Χιλβούδιου, magister militum per Thraciam? Στηριζόμενοι στη σύντομη μαρτυρία του Προκόπιου για τον στρατηγό της Θράκης Χιλβούδιο (περ.530-533), η οποία διαφωτίζει τη σχέση του με τον οίκο του Ιουστινιανού και τις στρατιωτικές του ικανότητες, οι συγγραφείς εξετάζουν μία χαμένη επιτύμβια επιγραφή από την Κωνσταντινούπολη (“ΕΝΘΑΔΕ ΚΑΤΑ ΚΕΙΤΕ ΧΙΛΙΒΟΥΔΙC ΙΥΟC CΑΝΒΑΤΙΟΥ ΤΕΛΕΥΤΑ ΜΗΝΙ ΝΟΕΝΒΡΙΟΥ ΚΗ ΙΝΔΣΖ ΓΑΜΕΤΗ ΧΙ + ΛΙΒΟΥΔΙΟΥ). Δίνεται έμφαση σε γλωσσολογικά ζητήματα σχετικά με το όνομα Χιλβούδιος καθώς και τη χρονολόγηση της επιγραφής.  Οι συγγραφείς αποδέχονται την αντική καταγωγή του Χιλβούδιου, αν και το όνομά του είναι μάλλον γερμανικό, και ότι υιοθετήθηκε από τον Σαββάτιο/Ιουστινιανό πριν από την άνοδο του τελευταίου στο θρόνο. Το γεγονός αυτό, σε συνάρτηση με την προτεινόμενη χρονολόγηση της επιγραφής το έτος 532/33, οδηγεί τους συγγραφείς στο συμπέρασμα ότι η επιγραφή είναι πολύ πιθανό να σχετίζεται με τον Χιλβούδιο magister militum per Thraciam.
Influences and interpretations of Byzantine history and culture in the literary work of the Modern Greek writer Nikos Gabriel Pentzikis
Authors: VAKALOUDI Anastasia D.
Published: November 2020

Επιρροές και Ερμηνείε ς της Βυζαντινής Ιστ ορίας και του Βυζαντινού Πολιτισμού στο Εργο του Σύγχρονου Έλληνα Λογοτέχνη Νίκου Γαβριήλ ΠεντζίκηΟ Νίκος Γαβριήλ Πεντζίκης γεννήθηκε στη Θεσσαλονίκη και ανήκει στη λεγόμενη «σχολή της Θεσσαλονίκης» και στη γενιά της δεκαετίας του 1930. Ο Πεντζίκης, στο έργο του, επιθυμεί να αναδείξει το διαχρονικό μεγαλείο της χριστιανικής – βυζαντινής Θεσσαλονίκης, επιλέγοντας την προσωποποίηση της πόλης ως βασικό στοιχείο μυθοποίησης, προκειμένου να δημιουργήσει τον μυθικό χαρακτήρα της πόλης και ταυτόχρονα να της αποδώσει μεταφυσικές ιδιότητες. Γι’ αυτό, ο συγγραφέας προσδίδει ανθρώπινη μορφή στη γενέθλια πόλη του. Ακόμη, συνδυάζει τον Ελληνισμό με τις λαϊκές παραδόσεις, τον μοντερνισμό και τα αυθεντικά, πρωταρχικά και μυθικά στοιχεία της ψυχής του έθνους, που θα μπορούσαν να καταστούν καθολικά πρότυπα και αρχέτυπα της σκέψης. Ο Πεντζίκης συνδυάζει τα στοιχεία του Ορθόδοξου βυζαντινού πολιτισμού και των αρχαίων ελληνικών μύθων με τις επιρροές που έχει δεχθεί από τον μοντερνισμό για να συνενώσει την ανατολική με τη δυτική πνευματική κουλτούρα και τη σύγχρονη ευρωπαϊκή διανόηση.
The Dome in Byzantine Church Architecture
Authors: PATRICIOS Nicholas Napoleon
Published: November 2020

Ο τρούλλος ήταν ένα σημαντικό αρχιτεκτονικό χαρακτηριστικότόσο στη ρωμαϊκή όσο και στη βυζαντινή περίοδο. Υποστηρίζεται ότιυπήρξε συνεχιζόμενη ανάπτυξη της αρχιτεκτονικής μορφής και τουσυμβολισμού του τρούλλου μεταξύ των δύο περιόδων, αλλά με επέκτασητης τυπολογίας του και σημαντική ενίσχυση του συμβολισμού του στηνεκκλησιαστική αρχιτεκτονική της βυζαντινής εποχής. Στο ερώτημα τίδιακρίνει τον τρούλλο μεταξύ των δύο περιόδων, η απάντηση πρέπεινα αναζητηθεί κατά κύριο λόγο στην λειτουργία τους – στην χρήση τουτρούλλου στα κοσμικά κτήρια κατά την Ρωμαϊκή περίοδο σε σύγκριση μετα κατά κύριο λόγο θρησκευτικά κτήρια του Βυζαντίου. Ο τρούλλος δενείναι μόνο ένα σταθερό αρχιτεκτονικό χαρακτηριστικό των βυζαντινώνεκκλησιών διαφόρων αρχιτεκτονικών τύπων αλλά συγχρόνως φορτίστηκεμε συμβολικά και θεολογικά μηνύματα και θεωρήθηκε ότι συμβολίζει τονουρανό και τον παράδεισο, ενώ στον εσωτερικό διάκοσμο προσδόθηκε μυστικιστική σημασία
Justinian’s Clemency and God’s Clemency
Authors: PARNELL David Alan
Published: November 2020

Η Φιλανθρωπία του Ιουστινιανού και η θεία ΦιλανθρωπίαΣύμφωνα με τις απόψεις της επιστημονικής έρευνας, ο αυτοκράτοραςΙουστινιανός δεν διακρινόταν για την φιλανθρωπία του. Αλλά κατάτην διάρκεια της βασιλείας του τόσο ο ίδιος όσο και οι υπουργοίτου κατηύθυναν μια συντονισμένη προσπάθεια να παρουσιασθεί ωςελεήμων. Ο Προκόπιος και ο Μαλάλας έχουν καταγράψει πολυάριθμακαι συγκεκριμένα παραδείγματα των μεγάλων πράξεων φιλανθρωπίαςτου αυτοκράτορα. Ο αυτοκράτορας και οι νομικοί του προέβαλαν τηνφιλανθρωπία στις Νεαρές, και αυλικοί όπως ο Αγαπητός και ο Παύλος οΣιλεντιάριος επαίνεσαν επίσης τον Ιουστινιανό. Η προπαγάνδα περί τηςφιλανθρωπίας του Ιουστινιανού βασίστηκε σε ιστορικές παραδόσεις απότην Ρωμαϊκή Αυτοκρατορία, τον ελληνιστικό κόσμο, και την χριστιανικήδιδασκαλία.
Fast Hybrid Schemes for Fractional Riccati Equations (Rough Is Not So Tough)
Authors: Callegaro Giorgia , Grasselli Martino , Pagès Gilles
Published: November 2020

We solve a family of fractional Riccati equations with constant (possibly complex) coefficients. These equations arise, for example, in fractional Heston stochastic volatility models, which have received great attention in the recent financial literature because of their ability to reproduce a rough volatility behavior. We first consider the case of a zero initial value corresponding to the characteristic function of the log-price. Then we investigate the case of a general starting value associated to a transform also involving the volatility process. The solution to the fractional Riccati equation takes the form of power series, whose convergence domain is typically finite. This naturally suggests a hybrid numerical algorithm to explicitly obtain the solution also beyond the convergence domain of the power series. Numerical tests show that the hybrid algorithm is extremely fast and stable. When applied to option pricing, our method largely outperforms the only available alternative, based on the Adams method.
Bridging Temporal Divides: Temporal Brokerage in Global Teams and Its Impact on Individual Performance
Authors: Mell Julija N. , Jang Sujin , Chai Sen
Published: November 2020

Members of global teams are often dispersed across time zones. This paper introduces the construct of temporal brokerage, which we define as being in a position within a team’s temporal structure that bridges subgroups that have little or no temporal overlap with each other. Although temporal brokerage is not a formal role, we argue that occupying such a position makes an individual more likely to take on more coordination work than other members on the team. We suggest that, while engaging in such coordination work has advantages in the form of enhanced integrative complexity, it also comes with costs in the form of a greater workload relative to other members. We further argue that the increased integrative complexity and workload that result from occupying a position of temporal brokerage have implications that go beyond the boundaries of the focal team, spilling over into other projects the individual is engaged in. Specifically, we predict that being in positions of temporal brokerage on global teams decreases the quantity but increases the quality of an individual’s total productive output. We find support for these predictions across two studies comprising 4,553 individuals participating in global student project teams and 123,586 individuals participating in global academic research teams, respectively. The framework and findings presented in this paper contribute to theories of global teamwork, pivotal roles and leadership emergence in global teams, and social network theory.
Positive psychology: self-compassion and its role within mental health nursing
Authors: Macfarlane Jan
Published: November 2020

This is the eighth article in a series that explores the meaning of positive psychology and the importance of applying the latest research findings to improve the wellbeing of the mental health workforce. It will focus on the positive psychology intervention of developing self-compassion and considers how the workforce can experience its uplifting effects through contemporary use in the field of mental health nursing. This article will highlight the underpinning theoretical work of Kristen Neff, in relation to self-compassion. It will explain what the term self-compassion means and its effect on neurological changes when it is practised. Finally, it emphasises how the application of self-compassion can benefit the individual, the organisation and the client. The practical tasks provided in the boxes throughout the article will help the reader identify what self-compassion means for them and understand how to further develop its transferability through evidence–based, user friendly exercises.
Single full-FOV reconstruction Fourier ptychographic microscopy
Authors: Zhu Youqiang , Sun Minglu , Chen Xiong , Li Hao , Mu Quanquan , Li Dayu , Xuan Li
Published: November 2020

Fourier ptychographic microscopy (FPM) is a recently developed computational imaging technique that has high-resolution and wide field-of-view (FOV). FPM bypasses the NA limit of the system by stitching a number of variable-illuminated measured images in Fourier space. On the basis of the wide FOV of the low NA objective, the high-resolution image with a wide FOV can be reconstructed through the phase recovery algorithm. However, the high-resolution reconstruction images are affected by the LED array point light source. The results are: (1) the intensities collected by the sample are severely declined when edge LEDs illuminate the sample; (2) the multiple reconstructions are caused by wavevectors inconsistency for the full FOV images. Here, we propose a new lighting scheme termed full FOV Fourier ptychographic microscopy (F3PM). By combining the LED array and telecentric lens, the method can provide plane waves with different angles while maintaining uniform intensity. Benefiting from the telecentric performance and f‒θ property of the telecentric lens, the system stability is improved and the relationship between the position of LED and its illumination angle is simplified. The excellent plane wave provided by the telecentric lens guarantees the same wavevector in the full FOV, and we use this wavevector to reconstruct the full FOV during one time. The area and diameter of the single reconstruction FOV reached 14.6mm2 and 5.4 mm, respectively, and the diameter is very close to the field number (5.5 mm) of the 4× objective. Compared with the traditional FPM, we have increased the diameter of FOV in a single reconstruction by ∼ 10 times, eliminating the complicated steps of computational redundancy and image stitching.
Dual modal fluorescent colposcope combined with near-infrared fluorescent dye TMTP1-PEG4-ICG to detect cervical lesions
Authors: Wang Chen , Zhou Ying , Li Wei , Liu Xiaohu , Xi Ling , Li Pengcheng , Wei Juncheng , Lu Jinling
Published: November 2020

To examine the cervical lesions by using the tumor-targeted near-infrared (NIR) fluorescent dyes TMTP1-PEG4-ICG, a dual modal colposcope with visible reflectance imaging and fluorescence imaging was developed. NIR fluorescence imaging and visible light reflectance imaging were integrated together on a colposcope by designing the specific optics and adopting a dual sensor charge coupled device (CCD) camera. Patients with squamous cell carcinoma, adenocarcinoma, cervical intraepithelial neoplasia (CIN) and cervicitis were examined using this dual modal colposcope to validate its potential of cervical cancer detection. Fluorescent dye TMTP1-PEG4-ICG was applied to the cervix 30 minutes before inspection. The fluorescence images were collected after wiping the unbound fluorescent dye using normal saline. Signal to back ratios (SBR) of the fluorescence images were analyzed and compared with the histological analysis. The results suggest that the fluorescent colposcope combined with tumor-specific near-infrared fluorescent dyes TMTP1-PEG4-ICG could help to evaluate cervical lesions in real time.
High Energy Wave-breaking-free Pulse from All-normaldispersion Fiber Laser with NALM
Authors: Deng Decai , Zhang Haitao , Gong Qihang , Zu Jiaqi
Published: November 2020

We explored the energy scalability in single pulse domain of all-normal-dispersion fiber laser with NALM numerically and experimentally. We conquered wave-breaking problem and achieved the highest pulse energy from the laser of this structure.
Tunable metasurfaces for independent control of linearly and circularly polarized terahertz waves
Authors: Wang Hang , Ling Fang , Zhang Bin
Published: November 2020

Metasurfaces provide an extraordinary way to control electromagnetic waves by abrupt change of optical properties within an optically thin interface. In this paper, by introducing vanadium dioxide (VO2) into the metasurface, efficient tunable terahertz phase modulation is designed to realize independent control of linearly and circularly polarized terahertz waves. The working resonator of the metasurface can be adjustable by controlling the temperature of VO2, resulting in the tunable function between resonant phase for linearly polarized waves and Pancharatnam-Berry phase for circularly polarized waves. As a proof of concept, two metasurfaces are designed for integrating two distinct functionalities in one structure, i.e. 1-bit metasurface switched between the abnormal THz deflector and the THz scatter and 3-bit metasurface switched between the vortex THz transmitter and the THz focusing mirror. The proposed tunable resonator structure provides a flexible way for extending the functionality of metadevice, which has a great potential value in integrated optics and wearable optics.
Equivalent thin-plate method for stressed mirror polishing of an off-axis aspheric silicon carbide lightweight mirror
Authors: Yi Liqi , Zhang Xuejun , Hu Haifei , Zhang Zhiyu , Zeng Xuefeng , Luo Xiao , Xue Donglin , Zhang Ge
Published: November 2020

No physical model of stressed mirror polishing, based on the small deflection and deformation of elastic thin plates, has been applied in processing lightweight mirrors. We propose an equivalent thin-plate method for the stressed loading of lightweight mirrors for the first time. Stressed loading and polishing of an aspheric lightweight mirror are simulated using the small-deflection deformation theory of an elastic thin plate. We simulate off-axis aspheric silicon carbide (SiC) lightweight mirrors with three different structures, determining the corresponding equivalent thickness plate in a lightweight structure with a nearly uniform surface density distribution and isotropic bending properties. We then establish a residual removal model of a stressed polishing surface, design the stressed loading equipment, and propose an iterative method for stressed polishing of an off-axis aspheric SiC lightweight mirror. The results demonstrate that it is feasible to choose a lightweight structure that performs full-aperture stressed polishing on off-axis aspheric lightweight mirrors consisting of SiC or other materials.
Engineering AlGaAs-on-insulator toward quantum optical applications
Authors: Placke Marlon , Ramelow Sven
Published: November 2020

Aluminum gallium arsenide has highly desirable properties for integrated parametric optical interactions: large material nonlinearities, maturely established nanoscopic structuring through epitaxial growth and lithography, and a large bandgap for broadband low-loss operation. However, its full potential for record-strength nonlinear interactions is only released when the semiconductor is embedded within a dielectric cladding to produce highly confining waveguides. From simulations of such, we present second- and third-order pair generation that could improve upon state-of-the-art quantum optical sources and make novel regimes of strong parametric photon–photon nonlinearities accessible.
Photonic spin Hall effect by anisotropy-induced polarization gradient in momentum space
Authors: Cai Lei , Zhang Shuang , Zhu Wenguo , Wu Hao , Zheng Huadan , Yu Jianhui , Zhong Yongchun , Chen Zhe
Published: November 2020

We demonstrate theoretically and experimentally a novel photonic spin Hall effect (PSHE), to the best of our knowledge, at an interface between air and uniaxial crystal, whose optical axis is within the interface plane. Owing to the anisotropy of the crystal, partial cross polarization conversion occurs. For a horizontally polarized paraxial Gaussian beam incidence, a linear polarization gradient forms along the in-plane wavevector in the reflected beam, allowing us to achieve spin separation in real space. The spin separation of the reflected beam can be tuned by rotating the optical axis of the crystal. A maximum spin-dependent displacement up to 0.45 times the incident beam waist is obtained at Brewster incidence. This novel anisotropy-induced PSHE deepens the understanding of spin–orbit interaction and provides a new way for control of spin photons.
Mid-infrared 10-µJ-level sub-picosecond pulse generation via stimulated Raman scattering in a gas-filled revolver fiber
Authors: Gladyshev Alexey , Yatsenko Yury , Kolyadin Anton , Kompanets Victor , Bufetov Igor
Published: November 2020

A sub-picosecond mid-infrared laser based on hollow-core silica fiber is demonstrated for the first time. By using deuterium-filled revolver fiber as an active medium, we realized efficient two-cascade Raman conversion 1.03 → 1.49 → 2.68 µm pumped by chirped pulses of a femtosecond ytterbium laser. The gas fiber Raman laser generates ∼920 fs pulses at 2.68 µm with output pulse energy as high as 10 µJ. It is shown that SRS can dominate other nonlinearities even in highly transient regime implemented in the mid-IR. The approach used may be applied to develop mid-IR laser sources of various types, such as frequency combs, supercontinuum and few-cycle pulse sources.
SiCTeC: An inexpensive, easily assembled Peltier device for rapid temperature shifting during single-cell imaging
Authors: Knapp Benjamin D. , Zhu Lillian , Huang Kerwyn Casey
Published: November 2020

Single-cell imaging, combined with recent advances in image analysis and microfluidic technologies, have enabled fundamental discoveries of cellular responses to chemical perturbations that are often obscured by traditional liquid-culture experiments. Temperature is an environmental variable well known to impact growth and to elicit specific stress responses at extreme values; it is often used as a genetic tool to interrogate essential genes. However, the dynamic effects of temperature shifts have remained mostly unstudied at the single-cell level, due largely to engineering challenges related to sample stability, heatsink considerations, and temperature measurement and feedback. Additionally, the few commercially available temperature-control platforms are costly. Here, we report an inexpensive (<$110) and modular Single-Cell Temperature Controller (SiCTeC) device for microbial imaging—based on straightforward modifications of the typical slide-sample-coverslip approach to microbial imaging—that controls temperature using a ring-shaped Peltier module and microcontroller feedback. Through stable and precise (±0.15°C) temperature control, SiCTeC achieves reproducible and fast (1–2 min) temperature transitions with programmable waveforms between room temperature and 45°C with an air objective. At the device’s maximum temperature of 89°C, SiCTeC revealed thatEscherichia colicells progressively shrink and lose cellular contents. During oscillations between 30°C and 37°C, cells rapidly adapted their response to temperature upshifts. Furthermore, SiCTeC enabled the discovery of rapid morphological changes and enhanced sensitivity to substrate stiffness during upshifts to nonpermissive temperatures in temperature-sensitive mutants of cell-wall synthesis enzymes. Overall, the simplicity and affordability of SiCTeC empowers future studies of the temperature dependence of single-cell physiology.
Rational design of highly potent broad-spectrum enterovirus inhibitors targeting the nonstructural protein 2C
Authors: Bauer Lisa , Manganaro Roberto , Zonsics Birgit , Hurdiss Daniel L. , Zwaagstra Marleen , Donselaar Tim , Welter Naemi G. E. , van Kleef Regina G. D. M. , Lopez Moira Lorenzo , Bevilacqua Federica , Raman Thamidur , Ferla Salvatore , Bassetto Marcella , Neyts Johan , Strating Jeroen R. P. M. , Westerink Remco H. S. , Brancale Andrea , van Kuppeveld Frank J. M.
Published: November 2020

There is a great need for antiviral drugs to treat enterovirus (EV) and rhinovirus (RV) infections, which can be severe and occasionally life-threatening. The conserved nonstructural protein 2C, which is an AAA+ ATPase, is a promising target for drug development. Here, we present a structure-activity relationship study of a previously identified compound that targets the 2C protein of EV-A71 and several EV-B species members, but not poliovirus (PV) (EV-C species). This compound is structurally related to the Food and Drug Administration (FDA)-approved drug fluoxetine—which also targets 2C—but has favorable chemical properties. We identified several compounds with increased antiviral potency and broadened activity. Four compounds showed broad-spectrum EV and RV activity and inhibited contemporary strains of emerging EVs of public health concern, including EV-A71, coxsackievirus (CV)-A24v, and EV-D68. Importantly, unlike (S)-fluoxetine, these compounds are no longer neuroactive. By raising resistant EV-A71, CV-B3, and EV-D68 variants against one of these inhibitors, we identified novel 2C resistance mutations. Reverse engineering of these mutations revealed a conserved mechanism of resistance development. Resistant viruses first acquired a mutation in, or adjacent to, the α2 helix of 2C. This mutation disrupted compound binding and provided drug resistance, but this was at the cost of viral fitness. Additional mutations at distantly localized 2C residues were then acquired to increase resistance and/or to compensate for the loss of fitness. Using computational methods to identify solvent accessible tunnels near the α2 helix in the EV-A71 and PV 2C crystal structures, a conserved binding pocket of the inhibitors is proposed.
Task-related activity in human visual cortex
Authors: Roth Zvi N. , Ryoo Minyoung , Merriam Elisha P.
Published: November 2020

The brain exhibits widespread endogenous responses in the absence of visual stimuli, even at the earliest stages of visual cortical processing. Such responses have been studied in monkeys using optical imaging with a limited field of view over visual cortex. Here, we used functional MRI (fMRI) in human participants to study the link between arousal and endogenous responses in visual cortex. The response that we observed was tightly entrained to task timing, was spatially extensive, and was independent of visual stimulation. We found that this response follows dynamics similar to that of pupil size and heart rate, suggesting that task-related activity is related to arousal. Finally, we found that higher reward increased response amplitude while decreasing its trial-to-trial variability (i.e., the noise). Computational simulations suggest that increased temporal precision underlies both of these observations. Our findings are consistent with optical imaging studies in monkeys and support the notion that arousal increases precision of neural activity.
Maximizing the reusability of gene expression data by predicting missing metadata
Authors: Lung Pei-Yau , Zhong Dongrui , Pang Xiaodong , Li Yan , Zhang Jinfeng
Published: November 2020

Reusability is part of the FAIR data principle, which aims to make data Findable, Accessible, Interoperable, and Reusable. One of the current efforts to increase the reusability of public genomics data has been to focus on the inclusion of quality metadata associated with the data. When necessary metadata are missing, most researchers will consider the data useless. In this study, we developed a framework to predict the missing metadata of gene expression datasets to maximize their reusability. We found that when using predicted data to conduct other analyses, it is not optimal to use all the predicted data. Instead, one should only use the subset of data, which can be predicted accurately. We proposed a new metric called Proportion of Cases Accurately Predicted (PCAP), which is optimized in our specifically-designed machine learning pipeline. The new approach performed better than pipelines using commonly used metrics such as F1-score in terms of maximizing the reusability of data with missing values. We also found that different variables might need to be predicted using different machine learning methods and/or different data processing protocols. Using differential gene expression analysis as an example, we showed that when missing variables are accurately predicted, the corresponding gene expression data can be reliably used in downstream analyses.
Interspike intervals within retinal spike bursts combinatorially encode multiple stimulus features
Authors: Ishii Toshiyuki , Hosoya Toshihiko
Published: November 2020

Neurons in various regions of the brain generate spike bursts. While the number of spikes within a burst has been shown to carry information, information coding by interspike intervals (ISIs) is less well understood. In particular, a burst with k spikes has k−1 intraburst ISIs, and these k−1 ISIs could theoretically encode k−1 independent values. In this study, we demonstrate that such combinatorial coding occurs for retinal bursts. By recording ganglion cell spikes from isolated salamander retinae, we found that intraburst ISIs encode oscillatory light sequences that are much faster than the light intensity modulation encoded by the number of spikes. When a burst has three spikes, the two intraburst ISIs combinatorially encode the amplitude and phase of the oscillatory sequence. Analysis of trial-to-trial variability suggested that intraburst ISIs are regulated by two independent mechanisms responding to orthogonal oscillatory components, one of which is common to bursts with a different number of spikes. Therefore, the retina encodes multiple stimulus features by exploiting all degrees of freedom of burst spike patterns, i.e., the spike number and multiple intraburst ISIs.
Analysis of RNA yield in extracellular vesicles isolated by membrane affinity column and differential ultracentrifugation
Authors: Gutiérrez García Gilberto , Galicia García Gabriela , Zalapa Soto Jessica , Izquierdo Medina Andrea , Rotzinger-Rodríguez Mariana , Casas Aguilar Gustavo Antonio , López Pacheco Cynthia Paola , Aguayo Álvaro , Aguilar-Hernandez Maria Montserrat
Published: November 2020

Extracellular vesicles (EV) have attracted much attention as potential biomarkers due to their protein, RNA and other nucleic acid content. The most common method used for EV isolation is differential ultracentrifugation (DU), however given the DU technical difficulties, other more practical methods have surged, such as membrane-affinity column commercial kits. Here, we assessed one commercial kit in terms of EV recovery and EV-derived RNA yield and compared it with a DU protocol. Our data shows that the commercial kit preparation results in a lower count of EV-like structures and a reduced expression of EV markers when compared to DU samples. Thus, apparently suggesting that the commercial kit had a lower EV yield. However, these findings did not reflect on RNA yield, which was greater with the commercial kit, even after an enzymatic treatment with proteinase K and RNAse A. We conclude that the kit has a higher EV-derived RNA yield in comparison to our DU protocol, suggesting that it may be the method of choice for RNA sequencing purposes.