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Two-dimensional chalcogenide semiconductors have recently emerged as a host material for quantum emitters of single photons. While several reports on defect and strain-induced single photon emission from 2D chalcogenides exist, a bottom-up, lithography-free approach to producing a high density of emitters remains elusive. Further, the physical properties of quantum emission in the case of strained 2D semiconductors are far from being understood. Here, we demonstrate a bottom-up, scalable, and lithography-free approach to creating large areas of localized emitters with high density (~150 emitters/um2) in a WSe2 monolayer. We induce strain inside the WSe2 monolayer with high spatial density by conformally placing the WSe2 monolayer over a uniform array of Pt nanoparticles with a size of 10 nm. Cryogenic, time-resolved, and gate-tunable luminescence measurements combined with near-field luminescence spectroscopy suggest the formation of localized states in strained regions that emit single photons with a high spatial density. Our approach of using a metal nanoparticle array to generate a high density of strained quantum emitters opens a new path towards scalable, tunable, and versatile quantum light sources., Comment: 45 pages, 20 figures (5 main figures, 15 supporting figures)

Optical birefringence is a fundamental optical property of crystals widely used for filtering and beam splitting of photons. Birefringent crystals concurrently possess the property of linear dichroism (LD) that allows asymmetric propagation or attenuation of light with two different polarizations. This property of LD has been widely studied from small molecules to polymers and crystals but has rarely been engineered per will. Here, we use the newly discovered spin-charge coupling in van der Waals antiferromagnetic (AFM) insulator FePS3 to induce large in-plane optical anisotropy and consequently LD. We report that the LD in this AFM insulator is tunable both spectrally and magnitude-wise as a function of cavity coupling. We demonstrate near-unity LD in the visible-near infrared range in cavity-coupled FePS3 crystals and derive its dispersion as a function of cavity length and FePS3 thickness. Our results hold wide implications for use of cavity tuned LD as a diagnostic probe for strongly correlated quantum materials as well as opens new opportunities for miniaturized, on-chip beam-splitters and tunable filters., 14 pages, 5 figures

This study examines cultural views of venture failure through the lens of sensemaking, which includes attributions of causality. Specifically, we explore failure accounts that are attributed to mistakes made by entrepreneurs, and those attributed to misfortunes outside the control of the entrepreneur. Reports of entrepreneurial failures from 1999 to 2001 were collected from seven major US newspapers, and 389 accounts of failure were analyzed for statements identifying the failure's cause. The data suggest that cultural sensemaking of failure varies by the geographical area where failure occurs. In addition, 331 accounts of the consequences of failure were analyzed which suggest that failure has a large impact on the stigmatization of the entrepreneur and entrepreneurship within the local area, as well as on the individual entrepreneur's view of themselves following failure.

With its continued emergence in both academic and practitioner communities, the diversity of organizations categorized as social entrepreneurship continues to expand. The increasing diversity represents a challenge to the field as it attempts to build a scientific base of knowledge. To address this issue, we build upon a typology of different forms of social entrepreneurship to theorize about how the role of ‘sites and spaces’ may affect the social entrepreneurial process. Specifically, we explain how variance in the geographic focus of different types of social entrepreneurship influences the types of social networks in which social entrepreneurship is embedded. Drawing upon this logic of embeddedness, we develop propositions about how the structural embeddedness of social entrepreneurship may affect the measurement and scaling of social value. The purpose of this article is to add to the relatively sparse but growing theoretical foundation of the field of social entrepreneurship.

Nonprofit organizations that engage in social enterprises can have difficulty reconciling the social service and business identities of their organization. In this exploratory qualitative interview study, we examine how social enterprises affect this organizational identity tension and how executive directors of nonprofits manage these multiple identities. Findings suggest that identity tension varied dependent upon the timing of conception of the social enterprise. Nonprofit leaders used different approaches to identity management and identity marketing for social enterprises: after conception and social enterprises: at conception. Initial guidance is provided about how nonprofits engaged in social enterprises can manage identity tension issues.

We conducted two studies to develop and test a multi-dimensional measure of entrepreneurial passion. This new scale is distinguished from scales measuring hope, optimism, state positive emotion, st...

We examine how establishing a mixed–sex entrepreneurial founding team may benefit women entrepreneurs in male–dominated cultures and industries. We contend that as a result of sex–based stereotypes, women entrepreneurs face unique obstacles in securing access to resources for their ventures. We argue that one way for women entrepreneurs to overcome these obstacles is to partner with a man. Drawing upon institutional, resource–based, and network theories, we theorize how partnering with a man may help provide women entrepreneurs in male–dominated contexts with enhanced legitimacy, access to a larger number of resources, and a stronger, more diverse social network.

Objectives/Hypothesis: Auditory neuropathy is a relatively recently described pattern of hearing loss characterized by preservation of outer hair cell function despite absent brainstem auditory evoked responses. Intact outer hair cell function is demonstrated by the presence of otoacoustic emissions and/or a measurable cochlear microphonic on electrocochleography, whereas no synchronous neural activity (absent action potentials) is seen on acoustically evoked brainstem auditory evoked response testing. The study reviews the authors' experience with six patients diagnosed with auditory neuropathy, four of whom have undergone cochlear implantation. Materials and Methods: A retrospective review of all medical and audiological charts at the University of Virginia Hospitals (Charlottesville, VA) was performed to identify patients who have undergone cochlear implantation or have been diagnosed with auditory neuropathy, or both. Results: Six patients with hearing loss attributable to auditory neuropathy were identified, four of whom have undergone cochlear implantation. Causes varied, including congenital, infectious, and idiopathic origins. Adults demonstrated subjective auditory perception on promontory stimulation, whereas no repeatable brainstem auditory evoked response waveforms could be demonstrated on pediatric promontory stimulation testing. Patients with implants demonstrated implant-evoked brainstem auditory evoked responses and improved audiological performance. Conclusions: The six cases presented in the study represent varied causes and, probably, varied sites of lesions of auditory neuropathy. Promontory stimulation has been valuable, particularly in adults. Cochlear implantation allows the opportunity to provide a supraphysiological electrical stimulation to the auditory nerve, with the hope of reintroducing synchronous neural activity. Greater confidence and enthusiasm for cochlear implantation in appropriately selected patients with auditory neuropathy are gained through experience with such diverse cases.

Objective: The establishment of a direct enteral feeding route is critical in the overall treatment of many patients with head and neck cancer. Use of radiologic percutaneous gastrostomy (RPG), the newest technique for gaining enteral access, has not been studied in such patients extensively. This study evaluated the indications, technique, success rate, and complications associated with RPG in patients with head and neck cancer. Study Design: Retrospective. Methods: A comprehensive chart review was undertaken of 56 patients with head and neck cancer treated at a tertiary care institution who had undergone successful or attempted RPG at some point during their treatment course. Results: Most study patients had advanced oropharyngeal squamous cell carcinoma. The most frequent indications for RPG were dysphagia/aspiration following tumor resection (n = 26) and dysphagia following completion of single-or combined-modality therapy (n = 22). The success rate of attempted RPGs was 98.2%. The overall complication rate for RPG was 12.7% (10.9% minor and 1.8% major). Conclusions : RPG is a valuable tool for establishing enteral nutrition in patients with head and neck cancer. Advantages of RPG include high success rate despite obstructing lesions, low complication rate, time efficiency and scheduling ease compared with intraoperative percutaneous gastrostomy (PEG) by a second team, no reported tumor seeding of the tube site, and the fact that postoperative RPG allows for more accurate selection of patients who require a gastrostomy tube.

We describe a rare case of progressive osseous heteroplasia of the face in a child. Biopsy showed osteoma cutis superficially with ectopic bone formation in the deeper tissues including skeletal muscle. Analysis of DNA from peripheral blood leukocytes showed mutations in the gene encoding the alpha subunit of the stimulatory G protein of adenylyl cyclase (GNAS1), confirming the diagnosis of progressive osseous heteroplasia.