bluuebunny/crossref_metadata_2025 huggingface dataset:
Amended oscillation criteria for second-order neutral differential equations with damping term
Authors: Moaaz Osama , Chatzarakis George E. , Abdeljawad Thabet , Cesarano Clemente , Nabih Amany
Published: October 2020

The aim of this work is to improve the oscillation results for second-order neutral differential equations with damping term. We consider the noncanonical case which always leads to two independent conditions for oscillation. We are working to improve related results by simplifying the conditions, based on taking a different approach that leads to one condition. Moreover, we obtain different forms of conditions to expand the application area. An example is also given to demonstrate the applicability and strength of the obtained conditions over known ones.
MEMS particle sensor based on resonant frequency shifting
Authors: Choi Ji-Seob , Park Woo-Tae
Published: October 2020

Recently, as the concentration of fine dust in the atmosphere has increased due to an increase in the use of fossil fuel power plants, automobiles, and factories, it has been increasingly important to measure fine dust in the atmosphere. This is because exposure to fine dust is closely related to the incidence of respiratory and cardiovascular diseases and eventually affects mortality. In this paper, we introduce a MEMS particle sensor based on the resonance frequency shift according to added particle mass. The actuation is driven by Aluminum nitride (AlN), and the total thickness is 2.8 μm. A laser doppler vibrometer (LDV), an optical measuring instrument, was used to measure the resonance frequency of the sensor. Airborne particles naturally were deposited on the sensor. To show the frequency shift according to the particle mass, the frequency shift was measured by dividing the case where the deposited particle mass was small and large. In each case, the frequency shift according to the deposited particle mass was predicted and compared with the frequency shift measured by LDV. It was shown that the deposited particle mass and frequency shift are proportional. The deposition of particulate mass was estimated by image analysis. The frequency shift caused by the particle mass deposited on the sensor was defined as the sensitivity of the sensor. The estimated sensitivity of the sensor is 0.219 to 0.354 kHz/pg.
New families of bivariate copulas via unit weibull distortion
Authors: Aldhufairi Fadal A.A. , Sepanski Jungsywan H.
Published: October 2020

This paper introduces a new family of bivariate copulas constructed using a unit Weibull distortion. Existing copulas play the role of the base or initial copulas that are transformed or distorted into a new family of copulas with additional parameters, allowing more flexibility and better fit to data. We present a general form for the new bivariate copula function and its conditional and density distributions. The tail behaviors are investigated and indicate the unit Weibull distortion may result in new copulas with upper tail dependence when the base copula has no upper tail dependence. The concordance ordering and Kendall’s tau are derived for the cases when the base copulas are Archimedean, such as the Clayton and Frank copulas. The Loss-ALEA data are analyzed to evaluate the performance of the proposed new families of copulas.
A pilot study examining the use of Goal Management Training in individuals with obsessive-compulsive disorder
Authors: Cameron Duncan H. , McCabe Randi E. , Rowa Karen , O’Connor Charlene , McKinnon Margaret C.
Published: October 2020

Background

Recent meta-analyses point towards cognitive impairments in obsessive-compulsive disorder (OCD), particularly in such executive function subdomains as planning and organization. Scant attention has focused on cognitive remediation strategies that may reduce cognitive dysfunction, with a possible corresponding decrease in symptoms of OCD.

Objective

The aim of this study was to assess the implementation of a standardized cognitive remediation program, Goal Management Training (GMT), in a pilot sample of individuals with OCD.

Method

Nineteen individuals with a primary DSM-5 diagnosis of OCD were randomized to receive either the 9-week GMT program (active group; n = 10) or to complete a 9-week waiting period (waitlist control; n = 9). Groups were assessed at baseline, post-treatment, and 3-month follow-up. The assessment comprised neuropsychological tasks assessing a variety of cognitive domains, and subjective measures of functioning and of symptom severity.

Results

The active condition showed significant improvements from baseline to post-treatment on measures of inattention, impulsivity, problem-solving, and organization compared to controls. Moreover, whereas the active group reported a significant improvement in subjective cognition over the course of treatment, no such improvement emerged in the waitlist group over this same period. Neither group showed improvement on indices of depressive, anxiety, or OCD-related symptom severity.

Discussion

The results of this small pilot investigation indicate that, although promising, this protocol requires several modifications to be best suited for this population. Replication of these findings is awaited, with current results potentially limited by sample characteristics including motivation to seek and complete treatment, and high attrition at 3-month follow-up (n = 6 completers).

Trial Registration

NCT02502604. (December 7, 2018)
The effects of cohousing model on people’s health and wellbeing: a scoping review
Authors: Carrere Juli , Reyes Alexia , Oliveras Laura , Fernández Anna , Peralta Andrés , Novoa Ana M. , Pérez Katherine , Borrell Carme
Published: October 2020

Background

Housing is a social determinant of health. Extensive research has highlighted its adverse effects on health. However, less is known about the effects of cohousing typology on health, which has the potential to create lively social networks and healthy communities and environments. We report the findings of a scoping study designed to gather and synthesise all known evidence on the relationship between cohousing and wellbeing and health.

Method

Using the scoping review method, we conducted a literature review in PubMed, ProQuest, Scopus, Web of Science, Science Direct and JSTOR in May 2019 and selected articles published from 1960 onwards, with no geographical limit and no design restrictions. Retrieved articles underwent three sequential screening phases. The results were described through a narrative synthesis of the evidence.

Results

Of the 2560 articles identified, we selected 25 full-text articles analysing 77 experiences. All of them were conducted in high-income countries. Ten studies analysed the impact of cohousing on physical and mental health or quality of life and wellbeing. Eight of the 10 studies found a positive association. In addition, 22 studies analysed one or more psychosocial determinants of health (such as social support, sense of community and physical, emotional and economic security) and most found a positive association. Through these determinants, quality of life, wellbeing and health could be improved. However, the quality of the evidence was low.

Discussion

The cohousing model could enhance health and wellbeing mediated by psychosocial determinants of health. However, extreme caution should be exercised in drawing any conclusions due to the dearth of data identified and the designs used in the included studies, with most being cross-sectional or qualitative studies, which precluded causal-based interpretations. Because housing is a major social determinant of health, more evidence is needed on the impact of this model on health through both psychosocial and material pathways.
Revascularization to the bone tunnel wall after anterior cruciate ligament reconstruction may relate to the distance from the vessels
Authors: Arai Yuji , Hara Kunio , Inoue Hiroaki , Kanamura Hitoshi , Nakagawa Shuji , Atsumi Satoru , Mikami Yasuo
Published: October 2020

Purpose

We use magnetic resonance angiography to evaluate the difference of vascular ingrowth to the bone tunnel on the anterior and posterior walls quantitatively after anterior cruciate ligament reconstruction.

Materials and methods

One hundred patients underwent anterior cruciate ligament reconstruction with multi-stranded semitendinosus tendons. They were retrospectively divided into those who underwent magnetic resonance angiography 2, 3, 4 to 6, and ≥ 7 months after surgery. The mean signal-to-noise ratios of the bone tunnel walls in the femur and tibia from the digital data were measured and compared for the anterior and posterior walls.

Results

The signal-to-noise ratio of the posterior wall of the femoral bone tunnel was significantly higher than that of the anterior wall in each group. On the tibial side, the signal-to-noise ratio of the anterior wall was significantly higher than that of the posterior wall at ≥4 months after surgery.

Conclusions

This study showed that the blood flow after anterior cruciate ligament reconstruction to the femoral bone tunnel is maintained from the posterior wall, and is maintained to the tibial side from the anterior wall 4 months postoperatively. Revascularization to the bone tunnel wall after anterior cruciate ligament reconstruction may relate to the distance from the vessels.
Pore structure of the Cretaceous lacustrine shales and shale-oil potential assessment in the Songliao Basin, Northeast China
Authors: Zeng Weizhu , Zhou Guoyi , Cao Taotao , Song Zhiguang
Published: October 2020

Aiming to study the pore structure and its impact on shale oil enrichment, a total of nine lacustrine shales (including one immature shale and eight mature shales) from the Qingshankou Formation in the Songliao Basin were subjected to low-pressure gas sorption (LPGS) of CO2 and N2 and mercury intrusion capillary pressure (MICP) measurements. The combination of the LPGS and MICP methods demonstrates that the pore volumes of these shales are mainly associated with mesopores, whereas the micropores and macropores are relatively undeveloped. The correlation between the shale compositions and pore volumes of LPGS suggests that the micropores and mesopores are mainly contributed by illite/smectite mixed layer mineral. On the contrary, we have found that the oil/bitumen and carbonates could occupy the micropores and mesopores, respectively, and reduce these pore volumes significantly. The oil saturation index (OSI) was found to display a positive correlation with the maturity Ro value in the range of 0.37%–1.24%, and this may suggest that the shale-oil content is controlled by hydrocarbon generation. However, the pore structure also exerts a great influence on the shale oil enrichment. We suggested that the porosity of MICP could be considered as an index for appraising the shale-oil potential of a given shale player because there is a good positive correlation between the porosity of MICP and the OSI value. Furthermore, a negative correlation between the micropore volume and the OSI value may imply that the shale oil could be adsorbed in micropores, whereas a good positive correlation between the OSI value and the Hg-retained ratio suggests that shale oil is a kind of residual hydrocarbon, which is closely related with the mesopore volume of these shales.
Association Between a National Insurer’s Pay-for-Performance Program for Oncology and Changes in Prescribing of Evidence-Based Cancer Drugs and Spending
Authors: Bekelman Justin E. , Gupta Atul , Fishman Ezra , Debono David , Fisch Michael J. , Liu Ying , Sylwestrzak Gosia , Barron John , Navathe Amol S.
Published: October 2020

PURPOSE

Cancer drug prescribing by medical oncologists accounts for the greatest variation in practice and the largest portion of spending on cancer care. We evaluated the association between a national commercial insurer’s ongoing pay-for-performance (P4P) program for oncology and changes in the prescribing of evidence-based cancer drugs and spending.

METHODS

We conducted an observational difference-in-differences study using administrative claims data covering 6.7% of US adults. We leveraged the geographically staggered, time-varying rollout of the P4P program to simulate a stepped-wedge study design. We included patients age 18 years or older with breast, colon, or lung cancer who were prescribed cancer drug regimens by 1,867 participating oncologists between 2013 and 2017. The exposure was a time-varying dichotomous variable equal to 1 for patients who were prescribed a cancer drug regimen after the P4P program was offered. The primary outcome was whether a patient’s drug regimen was a program-endorsed, evidence-based regimen. We also evaluated spending over a 6-month episode period.

RESULTS

The P4P program was associated with an increase in evidence-based regimen prescribing from 57.1% of patients in the preintervention period to 62.2% in the intervention period, for a difference of +5.1 percentage point (95% CI, 3.0 percentage points to 7.2 percentage points; P < .001). The P4P program was also associated with a differential $3,339 (95% CI, $1,121 to $5,557; P = .003) increase in cancer drug spending and a differential $253 (95% CI, $100 to $406; P = .001) increase in patient out-of-pocket spending, but no significant changes in total health care spending ($2,772; 95% CI, −$181 to $5,725; P = .07) over the 6-month episode period.

CONCLUSION

P4P programs may be effective in increasing evidence-based cancer drug prescribing, but may not yield cost savings.
Mitotic checkpoint protein Mad1 is required for early Nup153 recruitment to chromatin and nuclear envelope integrity
Authors: Mossaid Ikram , Chatel Guillaume , Martinelli Valérie , Vaz Marcela , Fahrenkrog Birthe
Published: October 2020

Nucleoporin Nup153 is a multifunctional protein and a known binding partner of mitotic checkpoint protein Mad1 (also known as MAD1L1). The functional relevance of their interaction has remained elusive. Here, we have further dissected the interface and functional interplay of Nup153 and Mad1. Using in situ proximity ligation assays, we found that the presence of a nuclear envelope (NE) is a prerequisite for the Nup153–Mad1 association. Time-lapse microscopy revealed that depletion of Mad1 delayed recruitment of Nup153 to anaphase chromatin, which was often accompanied by a prolongation of anaphase. Furthermore, as seen by electron microscopic and three-dimensional structured illumination investigations, Nup153 and Mad1 depletion led to alterations in NE architecture, characterised by a change of membrane curvature at nuclear pore complexes (NPCs) and an expansion of the spacing between inner and outer nuclear membranes. Nup153 depletion, but not Mad1 depletion, caused defects in interphase NPC assembly, with partial displacement of cytoplasmic nucleoporins and a reduction in NPC density. Taken together, our results suggest that Nup153 has separable roles in NE and NPC formation: in post-mitotic NE re-formation in concert with Mad1 and in interphase NPC assembly, independent of Mad1.
In vivocontinuous three-dimensional magnetic resonance microscopy: a study of metamorphosis in Carniolan worker honey bees (Apis mellifera carnica)
Authors: Mohorič Aleš , Božič Janko , Mrak Polona , Tušar Kaja , Lin Chenyun , Sepe Ana , Mikac Urša , Mikhaylov Georgy , Serša Igor
Published: October 2020

Three-dimensional (3D) magnetic resonance microscopy (MRM) is a modality of magnetic resonance imaging (MRI) optimized for the best resolution. Metamorphosis of the Carniolan worker honey bee (Apis mellifera carnica) was studied in vivo under controlled temperature and humidity conditions from sealed larva until the emergence of an adult. The 3D images were analyzed by volume rendering and segmentation, enabling the analysis of body, tracheal system and gastrointestinal tract through volume time course. Fat content sensitivity enabled the analysis of flight muscles transformation during the metamorphosis by the signal histogram and gray level co-occurrence matrix (GLCM). Although the transformation during metamorphosis is well known, MRM enables an alternative insight to this process, i.e., 3D in vivo which has relatively high spatial and temporal resolutions. The developed methodology can easily be adapted for studying metamorphosis of other insects or any other incremental biological process on a similar spatial and temporal scale.
European unity during the civil war in Libya (2015-2020)
Authors: Gasanov K.
Published: October 2020

The purpose of this study is to examine how cohesively EU member states’ act in Libya. A timeline (2015-2020) is justified by the fact that the real political process for uniting the country torn apart by civil war has been launched in 2015. The degree of unity is demonstrated by the analyses of the four powerful and most active member-states’ (France, Italy, Great Britain and Germany) positions on Libyan. The author develops the hypothesis (previously used in his researches) on the EU states’ political and economic interests, which have a decisive influence and define the course of the EU countries and, consequently, the cohesion of the EU foreign policy. The “changes on the ground” and the intervention of third countries identify additional variables, which influence the unity in the EU. The method is based on comparative analysis, where content analysis and study of documents are supportive methods. In conclusion we confirm the influence of political and economic priorities on the EU's ability to pursue a coherent policy towards third countries. At the same time, both intervening variables - “changing the situation on the ground” and the role of third countries - can promote unity or lead to a split. In any case, the lack of unity, coupled with the activity of third countries, deteriorate the influence of Brussels and, according to some estimates, marginalize the European Union in Libya.
No Substitute for the Real Thing: The Importance of In-Context Field Experiments in Fundraising
Authors: Goswami Indranil , Urminsky Oleg
Published: October 2020

This paper is an empirical case study of fundraising decisions that examines the adequacy of various sources of guidance and demonstrates the unique importance of in-context field experiments.
Gender Gaps in Equity Crowdfunding: Evidence from a Randomized Field Experiment
Authors: Bapna Sofia , Ganco Martin
Published: October 2020

Although prior research in traditional equity financing shows that male founders are preferred, emerging evidence in low-stakes crowdfunding (e.g., rewards-based crowdfunding) indicates that female entrepreneurs may have an advantage, particularly with female investors. We seek to examine whether investors in high-stakes equity crowdfunding, which includes elements from both traditional equity financing and low-stakes crowdfunding, respond differently to male and female founders. Specifically, we examine whether founder gender preferences, if they exist, vary based on the gender and the experience of the investor. Through a randomized field experiment, we find that inexperienced female investors are significantly more interested (138%) in ventures with female founders than those with male founders; however, we do not observe founder gender preferences among experienced female investors. For male investors, we do not observe differences in interest based on founder gender or investor experience. Thus, we confirm that the gender gaps observed in traditional equity financing are ameliorated in the equity crowdfunding context. Furthermore, we identify a boundary condition to the preference for female founders reported in earlier work involving low-stakes crowdfunding. In high-stakes crowdfunding, investor experience serves as a contingency that reduces female investors’ preference for female founders, potentially because of the weakening effects of activism homophily and the lower reliance on heuristics as investor experience increases.

This paper was accepted by Sridhar Tayur, entrepreneurship and innovation.
Revenue-Utility Tradeoff in Assortment Optimization Under the Multinomial Logit Model with Totally Unimodular Constraints
Authors: Sumida Mika , Gallego Guillermo , Rusmevichientong Paat , Topaloglu Huseyin , Davis James
Published: October 2020

We examine the revenue–utility assortment optimization problem with the goal of finding an assortment that maximizes a linear combination of the expected revenue of the firm and the expected utility of the customer. This criterion captures the trade-off between the firm-centric objective of maximizing the expected revenue and the customer-centric objective of maximizing the expected utility. The customers choose according to the multinomial logit model, and there is a constraint on the offered assortments characterized by a totally unimodular matrix. We show that we can solve the revenue–utility assortment optimization problem by finding the assortment that maximizes only the expected revenue after adjusting the revenue of each product by the same constant. Finding the appropriate revenue adjustment requires solving a nonconvex optimization problem. We give a parametric linear program to generate a collection of candidate assortments that is guaranteed to include an optimal solution to the revenue–utility assortment optimization problem. This collection of candidate assortments also allows us to construct an efficient frontier that shows the optimal expected revenue–utility pairs as we vary the weights in the objective function. Moreover, we develop an approximation scheme that limits the number of candidate assortments while ensuring a prespecified solution quality. Finally, we discuss practical assortment optimization problems that involve totally unimodular constraints. In our computational experiments, we demonstrate that we can obtain significant improvements in the expected utility without incurring a significant loss in the expected revenue.

This paper was accepted by Omar Besbes, revenue management and market analytics.
Minimax-Optimal Policy Learning Under Unobserved Confounding
Authors: Kallus Nathan , Zhou Angela
Published: October 2020

We study the problem of learning personalized decision policies from observational data while accounting for possible unobserved confounding. Previous approaches, which assume unconfoundedness, that is, that no unobserved confounders affect both the treatment assignment as well as outcome, can lead to policies that introduce harm rather than benefit when some unobserved confounding is present as is generally the case with observational data. Instead, because policy value and regret may not be point-identifiable, we study a method that minimizes the worst-case estimated regret of a candidate policy against a baseline policy over an uncertainty set for propensity weights that controls the extent of unobserved confounding. We prove generalization guarantees that ensure our policy is safe when applied in practice and in fact obtains the best possible uniform control on the range of all possible population regrets that agree with the possible extent of confounding. We develop efficient algorithmic solutions to compute this minimax-optimal policy. Finally, we assess and compare our methods on synthetic and semisynthetic data. In particular, we consider a case study on personalizing hormone replacement therapy based on observational data, in which we validate our results on a randomized experiment. We demonstrate that hidden confounding can hinder existing policy-learning approaches and lead to unwarranted harm although our robust approach guarantees safety and focuses on well-evidenced improvement, a necessity for making personalized treatment policies learned from observational data reliable in practice.

This paper was accepted by Hamid Nazerzadeh, big data analytics.
A General Framework to Compare Announcement Accuracy: Static vs. LES-Based Announcement
Authors: Bassamboo Achal , Ibrahim Rouba
Published: October 2020

Service providers often share delay information, in the form of delay announcements, with their customers. In practice, simple delay announcements, such as average waiting times or a weighted average of previously delayed customers, are often used. Our goal in this paper is to gain insight into when such announcements perform well. Specifically, we compare the accuracies of two announcements: (i) a static announcement that does not exploit real-time information about the state of the system and (ii) a dynamic announcement, specifically the last-to-enter-service (LES) announcement, which equals the delay of the last customer to have entered service at the time of the announcement. We propose a novel correlation-based approach that is theoretically appealing because it allows for a comparison of the accuracies of announcements across different queueing models, including multiclass models with a priority service discipline. It is also practically useful because estimating correlations is much easier than fitting an entire queueing model. Using a combination of queueing-theoretic analysis, real-life data analysis, and simulation, we analyze the performance of static and dynamic announcements and derive an appropriate weighted average of the two which we demonstrate has a superior performance using both simulation and data from a call center.

This paper was accepted by Vishal Gaur, operations management.
Detecting Customer Trends for Optimal Promotion Targeting
Authors: Baardman Lennart , Boroujeni Setareh Borjian , Cohen-Hillel Tamar , Panchamgam Kiran , Perakis Georgia
Published: October 2020

Problem definition: Retailers have become increasingly interested in personalizing their products and services such as promotions. For this, we need new personalized demand models. Unfortunately, social data are not available to many retailers because of cost and privacy issues. Thus, we focus on the problem of detecting customer relationships from transactional data and using them to target promotions to the right customers. Academic/practical relevance: From an academic point of view, this paper solves the novel problem of jointly detecting customer trends and using them for optimal promotion targeting. Notably, we estimate the causal customer-to-customer trend effect solely from transactional data and target promotions for multiple items and time periods. In practice, we provide a new tool for Oracle Retail clients that personalizes promotions. Methodology: We develop a novel customer trend demand model distinguishing between a base purchase probability, capturing factors such as price and seasonality, and a customer trend probability, capturing customer-to-customer trend effects. The estimation procedure is based on regularized bounded variables least squares and instrumental variable methods. The resulting customer trend estimates feed into the dynamic promotion targeting optimization problem, formulated as a nonlinear mixed-integer optimization model. Though it is nondeterministic polynomial-time hard, we propose a greedy algorithm. Results: We prove that our customer-to-customer trend estimates are statistically consistent and that the greedy optimization algorithm is provably good. Having access to Oracle Retail fashion client data, we show that our demand model reduces the weighted-mean absolute percentage error by 11% on average. Also, we provide evidence of the causality of our estimates. Finally, we demonstrate that the optimal policy increases profits by 3%–11%. Managerial implications: The demand model with customer trend and the optimization model for targeted promotions form a decision-support tool for promotion planning. Next to general planning, it also helps to find important customers and target them to generate additional sales.

History: This paper has been accepted as part of the 2019 Manufacturing & Service Operations Management Practice-Based Research Competition.

Funding: This work was supported by the U.S. National Science Foundation [Grant CMMI-156334]. Funding from the Oracle Corporation through an ERO grant is also gratefully acknowledged.

Supplemental Material: The online appendices are available at https://doi.org/10.1287/msom.2020.0893 .
On the Role of Teletriage in Healthcare Demand Management
Authors: Çakıcı Özden Engin , Mills Alex F.
Published: October 2020

Problem definition: Many healthcare providers and payers offer teletriage, a telemedicine service where concerned patients can get advice about their health condition. In theory, teletriage should help patients with an acute illness choose an appropriate provider, reducing unnecessary and duplicate provider visits, yet no study has assessed the overall costs and benefits of teletriage at a system level. Academic/practical relevance: We model the use of teletriage in managing healthcare demand and determine in which cases teletriage is efficient and effective. Our model extends the academic literature on service operations and provides practical suggestions for healthcare payers. Methodology: We use a Markov decision process to model a patient’s choices during an acute illness episode, where the illness severity is partially observable to the patient and triage is subject to errors. We parameterize the model using data from the literature and provide both structural and numerical results. Results: Patients with high uncertainty about their state would use the teletriage service, which may improve their cost outcomes. However, when teletriage is added, the rate of arrivals to the emergency department (ED) may increase when the overtriage rate is above 5%, the lowest value observed in the literature. Patient’s choices and the copayment of other services affect the cost-effectiveness of teletriage. Managerial implications: There are several reasons why adding teletriage to the healthcare system could produce a negative cost outcome. Teletriage should not necessarily be free, which would encourage use by patients with low levels of uncertainty and actually increase the payer’s total cost. The overtriage rate is a key driver of performance and must be managed carefully.
Coordinating Project Outsourcing Through Bilateral Contract Negotiations
Authors: Hou Chengfan , Lu Mengshi , Deng Tianhu , Shen Zuo-Jun Max
Published: October 2020

Problem definition: Project outsourcing has been a pronounced trend in many industries but is also recognized as a major cause for project delays. We study how companies can coordinate outsourced projects with uncertain completion times through bilateral contract negotiations. Academic/practical relevance: Misaligned subcontractor incentives may result in substantial losses to both project clients and subcontractors. Coordinating subcontractors’ efforts through proper contracts is imperative to the success of project outsourcing. Most previous studies on project contracting have not addressed subcontractors’ bargaining powers or the dynamic bargaining process in negotiations. We fill in this gap by studying bilateral bargaining between the client and subcontractors, which better reflects real-world negotiations. Methodology: We model project contract negotiations as a multiunit bilateral bargaining game. We derive the conditions such that bilateral negotiations can achieve system coordination and characterize the equilibrium negotiation outcomes. We then compare the conditions and equilibria under various model settings to study their impact on project contracting. Results: Our study uncovers how the coordination of project outsourcing is impacted by the contract form, bargaining power structure, precedence network topology, payment timing, external opportunities, and negotiation protocols. For single-task projects, the widely used fixed-price (cost-plus) contract can achieve system coordination only when the subcontractor (client) possesses full bargaining power. Cost-sharing and time-based incentive contracts, which perform well for single-task projects, may not be effective for projects with parallel tasks when any subcontractor’s bargaining power is sufficiently high. Projects with serial tasks can be coordinated only under certain extreme bargaining power structures. Delaying payments always exacerbates the incentive misalignment. Managerial implications: Our analysis provides insights and guidelines to companies regarding how to select proper contract forms and payment timing schemes, based on the characteristics of the projects and subcontractors, to ensure the effectiveness of project outsourcing. Our results also highlight the importance of bargaining modeling in project contracting.
Abelhas ou Zangões: as primeiras normas para o profissional da farmácia do Brasil no início do século XIX
Authors: Peruchi Amanda
Published: October 2020

Este trabalho tem o objetivo de apresentar os primeiros resultados de uma pesquisa que vem sendo desenvolvida no âmbito do doutorado acerca da institucionalização da farmácia no Brasil do século XIX – mais especificamente entre 1808 e 1891. Ou seja, das primeiras aulas de matéria médica e farmacêutica nas escolas de cirurgia até a criação da primeira Faculdade de Farmácia em território brasileiro. Uma das propostas desta pesquisa é investigar a construção e a regularização do profissional da farmácia diplomado e licenciado, conforme as exigências da época. Deste modo, este artigo busca analisar o que previam, sobretudo, as primeiras leis versadas aos profissionais da farmácia e como elas teriam contribuído para que os “verdadeiros farmacêuticos” pudessem ser identificados e diferenciados dos outros que, embora produzissem e vendessem medicamentos e, consequentemente, fizessem parte do cenário da farmácia carioca oitocentista, não eram regularizados e, perante a lei, não deveriam atuar como tal.
Visitando obras historiográficas do Império Lusitano na Oceania: Um recorte da história de Timor-Leste
Authors: Maia Hélio José Santos , Oliveira Urânia Auxiliadora Santos Maia de
Published: October 2020

O artigo procura relacionar literatura historiográfica do Império Português do período colonial de Timor-Leste como fonte de argumentos para uma literatura ficcional pós-colonial por meio de duas obras de grande importância para o entendimento do período. As narrativas das obras As possessões Portuguesas na Oceania de Afonso de Castro de 1867 e Ocupação e Colonização Branca de Timor de Teófilo Duarte de 1940, ambos antigos governadores portugueses de Timor-Leste, são abundantes e apresentam fatos de grande beleza literária, que como fatos históricos, contam a saga do povo timorense. Com esse direcionamento o artigo traça o processo de colonização no rastro das Grandes Navegações que iniciou a globalização e a dominação cultural para culminar na historiografia oficial de Timor e os argumentos literários que dela podem ser colhidos. O trabalho é parte de pesquisa de doutoramento de um de seus autores e como metodologia procedeu-se a pesquisa bibliográfica a documentos históricos presentes na Biblioteca da Pós-Graduação da Universidade Nacional de Timor Lorosa'e.
Um correio pelo caminho de terra: as comunicações no Estado do Maranhão e Grão-Pará nos princípios do século XVIII
Authors: Salvino Romulo Valle
Published: October 2020

Durante a Idade Moderna, o funcionamento das monarquias e dos negócios dependia da circulação de cartas, ofícios, normas, petições e outros documentos das mais diversas naturezas, tanto em território europeu quanto nos espaços ultramarinos. Tendo em vista as grandes diferenças regionais, as redes que garantiam a comunicação escrita nesses “impérios de papel” assumiram diversas feições nos vários territórios. A partir dessa premissa, este artigo aborda a iniciativa pioneira de Alexandre de Sousa Freire, governador do Maranhão e Grão-Pará, que estabeleceu um correio mensal entre São Luís e Belém por volta de 1730. O estudo busca entender o caso à luz não somente de seus aspectos regionais, mas também diante da história dos sistemas de correios do período moderno, inclusive de um episódio crucial para a comunicação escrita na monarquia portuguesa, qual seja a proibição por D. João V de que o correio-mor atuasse no interior da América.
How to … effectively motivate and support
Authors: Ashurst Adrian
Published: October 2020

As daily life continues to be affected by COVID-19 and infection control measures, it can be difficult to sustain energy and motivation, both in yourself and the people around you. Adrian Ashurst discusses some top tips to help support both yourself and those in your care through these difficult times
‘Race’, Parental Occupation and Academic Performance in a Public School Population
Authors: Halperin Kopl
Published: October 2020

Races of humans exist only as socially defined constructs.  It is widely believed that there is a difference in educational  achievement between the major "races" in America - "blacks" and "whites".  The objective here was to test the veracity of this belief by studying a population that was relatively homogenous on parental occupation.  This study found that in a population of 133 13 to 14 year old science students in an affluent public middle school, there was no gap between the academic achievement of students categorized as "black" and students categorized as "white".  Stratifying by parental occupation eliminated any distinction.  "Asian" students outperformed all other students.   Solving the inequities in education should involve consideration of parental occupation.
Mobilising episodic volunteers for Mandela Day
Authors: Compion Sara , Jeong Bok Gyo , Cnaan Ram , Meijs Lucas
Published: October 2020

18 July is Mandela Day, an internationally recognised day of volunteering when people are called to take action against poverty and social injustice by helping and giving time in service to their communities. This article discusses the nature of episodic volunteering at Mandela Day events throughout South Africa in 2018. Drawing on quantitative survey evidence from 398 participants, the findings show that this informal day of service has created a unique opportunity for recruiting new volunteers and for promoting one-off, short-term volunteering. In addition to non-profits and faith-based groups that traditionally mobilise volunteers, we show that ‘third-party’ entities – such as universities, businesses, government offices and philanthropic foundations – are also critical in rallying people and facilitating one-off volunteering opportunities for this day. These findings broaden an understanding of the range of international episodic volunteering and help to illustrate the connection between volunteering and civic capacity in newer democracies.
Parental leave – and then what? A study of new parents’ negotiations about work, care and parental leave
Authors: Alsarve Jenny
Published: October 2020

Drawing on qualitative interviews with Swedish mothers and fathers, this article aims to study the negotiations between parents before and after the birth of their first child. When expecting a child, parents need for instance to decide how to divide their parental leave. After the child is born they have to negotiate about the division of care tasks, paid work and housework. The aim of this article is to analyse how these negotiations take place, and how the initial negotiations are followed up later, when the couple become parents. The overall research question is as follows: how are the negotiations about the division of care and work embedded in other social relationships, and in workplace and financial conditions? Swedish parents are particularly interesting to study because gender equality has been a political goal for a long time in Sweden. Nonetheless, earlier studies of Swedish parents have shown that the division of work and care becomes more ‘traditional’ as couples become parents, and Swedish women still take more parental leave than men (Boye and Evertsson, 2014; Duvander and Wiklund, 2019). The results show that the couples were engaged in constant explicit or implicit negotiations about the daily care. The results furthermore indicate that factors like working conditions influenced the decision-making processes, as did relationships with, for instance, the child’s grandmothers.
Numerical investigation of depth-sensitive diffuse reflectance and fluorescence measurements on murine subcutaneous tissue with growing solid tumors
Authors: Carrico Evan , Sun Tengfei , Zhu Caigang
Published: October 2020

In most biomedical optical spectroscopy platforms, a fiber-probe consisting of single or multiple illumination and collection fibers was commonly used for the delivery of illuminating light and the collection of emitted light. Typically, the signals from all collection fibers were combined and then sampled to characterize tissue samples. Such simple averaged optical measurements may induce significant errors for in vivo tumor characterization, especially in longitudinal studies where the tumor size and location vary with tumor stages. In this study, we utilized the Monte Carlo technique to optimize the fiber-probe geometries of a spectroscopy platform to enable tumor-sensitive diffuse reflectance and fluorescence measurements on murine subcutaneous tissues with growing solid tumors that have different sizes and depths. Our data showed that depth-sensitive techniques offer improved sensitivity in tumor detection compared to the simple averaged approach in both reflectance and fluorescence measurements. Through the numerical studies, we optimized the source-detector distances, fiber diameters, and numerical apertures for sensitive measurement of small solid tumors with varying size and depth buried in murine subcutaneous tissues. Our study will advance the design of a fiber-probe in an optical spectroscopy system that can be used for longitudinal tumor metabolism and vasculature monitoring.
Portable ultra-widefield fundus camera for multispectral imaging of the retina and choroid
Authors: Toslak Devrim , Son Taeyoon , Erol Muhammet Kazim , Kim Hoonsup , Kim Tae-Hoon , Chan R. V. Paul , Yao Xincheng
Published: October 2020

Multispectral imaging (MSI) of the retina and choroid has increasing
interest for better diagnosis and treatment evaluation of eye
diseases. However, currently available MSI systems have a limited
field of view (FOV) to evaluate the peripheral retina. This study is
to validate trans-pars-planar illumination for a contact-mode
ultra-widefield MSI system. By freeing the available pupil for
collecting imaging light only, the trans-pars-planar illumination
enables a portable, non-mydriatic fundus camera, with 200° FOV
in a single fundus image. The trans-pars-planar illumination,
delivering illumination light from one side of the eye, naturally
enables oblique illumination ophthalmoscopy to enhance the contrast of
fundus imaging. A broadband (104 nm) 565 nm light-emitting diode (LED)
is used for validating color fundus imaging first. Four narrowband
(17-60 nm) 530 nm, 625 nm, 780 nm, and 970 nm LEDs are tested for MSI.
With 530 nm illumination, the fundus image reveals retinal vasculature
predominantly. 625 nm and 780 nm illuminations enhance the visibility
of choroidal vasculature. With further increased wavelength of 970 nm,
the fundus image is predominated by large veins in the choroid, with
multiple vortex ampullas observed simultaneously in a single fundus
image.
Poynting vector and beam divergence
Authors: Niziev Vladimir , Muys Peter
Published: October 2020

Laser beam divergence was considered using the components of the Poynting vector. A physical interpretation of the real and imaginary parts of the “longitudinal” field component (along the

z

axis, the direction of beam propagation) is given in an exponential representation. The longitudinal field component was shown to be the reason for the formation of laser beam divergence. This fact was used to reveal fundamental differences between Laguerre–Gaussian beams and incoherent rays in the focal region. The possibility of using selective action on the longitudinal field component to decrease the divergence of Laguerre–Gaussian beams is discussed.
Rapid fabrication of anti-corrosion and self-healing superhydrophobic aluminum surfaces through environmentally friendly femtosecond laser processing
Authors: Yuan Gan , Liu Yu , Ngo Chi-Vinh , Guo Chunlei
Published: October 2020

The development of superhydrophobic metals has found many applications such as self-cleaning, anti-corrosion, anti-icing, and water transportation. Recently, femtosecond laser has been used to create nano/microstructures and wetting property changes. However, for some of the most common metals, such as aluminum, a relatively long aging process is required to obtain stable hydrophobicity. In this work, we introduce a combination of femtosecond laser ablation and heat treatment post-process, without using any harsh chemicals. We turn aluminum superhydrophobic within 30 minutes of heat treatment following femtosecond laser processing, and this is significantly shorter compared to conventional aging process of laser-ablated aluminum. The superhydrophobic surfaces maintain high contact angles greater than 160° and low sliding angles smaller than 5° over two months after the heat treatment. Moreover, the samples exhibit strong superhydrophobicity for various types of liquids (milk, coffee, CuPc, R6G, HCl, NaOH and CuCl2). The samples also show excellent self-healing and anti-corrosion properties. The mechanism for fast wettability conversion time is discussed. Our technique is a rapid process, reproducible, feasible for large-area fabrication, and environment-friendly.
Modulation format-independent optical performance monitoring technique insensitive to chromatic dispersion and polarization mode dispersion using a multi-task artificial neural network
Authors: Zheng Hao , Li Wei , Mei Muyang , Wang You , Feng Zhongshuai , Chen Yaobin , Shao Weidong
Published: October 2020

We propose and experimentally demonstrate modulation format-independent optical performance monitoring (OPM) based on a multi-task artificial neural network (MT-ANN). Optical power measurements at a series of center wavelengths adjusted using a widely tunable optical bandpass filter (OBPF) are used as the input features for a MT-ANN to simultaneously realize high-precision optical signal-to-noise ratio (OSNR) and launch power monitoring and baud rate identification (BRI). This technique is insensitive to chromatic dispersion (CD) and polarization mode dispersion (PMD). The experimental verification in a 9-channel WDM system shows that for 10 Gbaud QPSK and 32 Gbaud PDM-16QAM signals with OSNR in the range of 1–30 dB, the OSNR mean absolute error (MAE) and root mean square error (RMSE) are 0.28 dB and 0.48 dB, respectively. For launch power in the range of 0–8 dBm, the MAE and RMSE of the launch power monitoring are 0.034 dB and 0.066 dB, respectively, and the identification accuracy for both baud rates is 100%. Furthermore, this technique utilizes a single MT-ANN instead of three ANNs to realize the simultaneous monitoring of three OPM parameters, which greatly reduces the cost and complexity.
Leveraging scatter in two-dimensional spectroscopy: passive phase drift correction enables a global phasing protocol
Authors: Lloyd Lawson T. , Wood Ryan E. , Allodi Marco A. , Sohoni Siddhartha , Higgins Jacob S. , Otto John P. , Engel Gregory S.
Published: October 2020

Phase stability between pulse pairs defining Fourier-transform time delays can limit resolution and complicates development and adoption of multidimensional coherent spectroscopies. We demonstrate a data processing procedure to correct the long-term phase drift of the nonlinear signal during two-dimensional (2D) experiments based on the relative phase between scattered excitation pulses and a global phasing procedure to generate fully absorptive 2D electronic spectra of wafer-scale monolayer MoS2. Our correction results in a ∼30-fold increase in effective long-term signal phase stability, from ∼λ/2 to ∼λ/70 with negligible extra experimental time and no additional optical components. This scatter-based drift correction should be applicable to other interferometric techniques as well, significantly lowering the practical experimental requirements for this class of measurements.