Mid-infrared plasmons in scaled graphene nanostructures

Plasmonics takes advantage of the collective response of electrons to electromagnetic waves, enabling dramatic scaling of optical devices beyond the diffraction limit. Here, we demonstrate the mid-infrared (4 to 15 microns) plasmons in deeply scaled graphene nanostructures down to 50 nm, more than 100 times smaller than the on-resonance light wavelength in free space. We reveal, for the first time, the crucial damping channels of graphene plasmons via its intrinsic optical phonons and scattering from the edges. A plasmon lifetime of 20 femto-seconds and smaller is observed, when damping through the emission of an optical phonon is allowed. Furthermore, the surface polar phonons in SiO2 substrate underneath the graphene nanostructures lead to a significantly modified plasmon dispersion and damping, in contrast to a non-polar diamond-like-carbon (DLC) substrate. Much reduced damping is realized when the plasmon resonance frequencies are close to the polar phonon frequencies. Our study paves the way for applications of graphene in plasmonic waveguides, modulators and detectors in an unprecedentedly broad wavelength range from sub-terahertz to mid-infrared.Comment: submitte

Human resources for health: task shifting to promote basic health service delivery among internally displaced people in ethnic health program service areas in eastern Burma/Myanmar.

BACKGROUND: Burma/Myanmar was controlled by a military regime for over 50 years. Many basic social and protection services have been neglected, specifically in the ethnic areas. Development in these areas was led by the ethnic non-state actors to ensure care and the availability of health services for the communities living in the border ethnic-controlled areas. Political changes in Burma/Myanmar have been ongoing since the end of 2010. Given the ethnic diversity of Burma/Myanmar, many challenges in ensuring health service coverage among all ethnic groups lie ahead. METHODS: A case study method was used to document how existing human resources for health (HRH) reach the vulnerable population in the ethnic health organizations' (EHOs) and community-based organizations' (CBHOs) service areas, and their related information on training and services delivered. Mixed methods were used. Survey data on HRH, service provision, and training were collected from clinic-in-charges in 110 clinics in 14 Karen/Kayin townships through a rapid-mapping exercise. We also reviewed 7 organizational and policy documents and conducted 10 interviews and discussions with clinic-in-charges. FINDINGS: Despite the lack of skilled medical professionals, the EHOs and CBHOs have been serving the population along the border through task shifting to less specialized health workers. Clinics and mobile teams work in partnership, focusing on primary care with some aspects of secondary care. The rapid-mapping exercise showed that the aggregate HRH density in Karen/Kayin state is 2.8 per 1,000 population. Every mobile team has 1.8 health workers per 1,000 population, whereas each clinic has between 2.5 and 3.9 health workers per 1,000 population. By reorganizing and training the workforce with a rigorous and up-to-date curriculum, EHOs and CBHOs present a viable solution for improving health service coverage to the underserved population. CONCLUSION: Despite the chronic conflict in Burma/Myanmar, this report provides evidence of the substantive system of health care provision and access in the Karen/Kayin State over the past 20 years. It underscores the climate of vulnerability of the EHOs and CBHOs due to lack of regional and international understanding of the political complexities in Burma/Myanmar. As Association of Southeast Asian Nations (ASEAN) integration gathers pace, this case study highlights potential issues relating to migration and health access. The case also documents the challenge of integrating indigenous and/or cross-border health systems, with the ongoing risk of deepening ethnic conflicts in Burma/Myanmar as the peace process is negotiated

Dijet signals of the Little Higgs model with T-parity

The Littest Higgs model with T-parity (LHT), apart from offering a viable solution to the naturalness problem of the Standard Model, also predicts a set of new fermions as well as a candidate for dark matter. We explore the possibility of discovering the heavy T-odd quark Q_H at the LHC in a final state comprising two hard jets with a large missing transverse momentum. Also discussed is the role of heavy flavor tagging.Comment: Changes in text. Some references adde

Theory of Star Formation

We review current understanding of star formation, outlining an overall theoretical framework and the observations that motivate it. A conception of star formation has emerged in which turbulence plays a dual role, both creating overdensities to initiate gravitational contraction or collapse, and countering the effects of gravity in these overdense regions. The key dynamical processes involved in star formation -- turbulence, magnetic fields, and self-gravity -- are highly nonlinear and multidimensional. Physical arguments are used to identify and explain the features and scalings involved in star formation, and results from numerical simulations are used to quantify these effects. We divide star formation into large-scale and small-scale regimes and review each in turn. Large scales range from galaxies to giant molecular clouds (GMCs) and their substructures. Important problems include how GMCs form and evolve, what determines the star formation rate (SFR), and what determines the initial mass function (IMF). Small scales range from dense cores to the protostellar systems they beget. We discuss formation of both low- and high-mass stars, including ongoing accretion. The development of winds and outflows is increasingly well understood, as are the mechanisms governing angular momentum transport in disks. Although outstanding questions remain, the framework is now in place to build a comprehensive theory of star formation that will be tested by the next generation of telescopes.Comment: 120 pages, to appear in ARAA. No changes from v1 text; permission statement adde

Quantum surface-response of metals revealed by acoustic graphene plasmons

A quantitative understanding of the electromagnetic response of materials is essential for the precise engineering of maximal, versatile, and controllable light-matter interactions. Material surfaces, in particular, are prominent platforms for enhancing electromagnetic interactions and for tailoring chemical processes. However, at the deep nanoscale, the electromagnetic response of electron systems is significantly impacted by quantum surface-response at material interfaces, which is challenging to probe using standard optical techniques. Here, we show how ultraconfined acoustic graphene plasmons in graphene-dielectric-metal structures can be used to probe the quantum surface-response functions of nearby metals, here encoded through the so-called Feibelman d-parameters. Based on our theoretical formalism, we introduce a concrete proposal for experimentally inferring the low-frequency quantum response of metals from quantum shifts of the acoustic graphene plasmons dispersion, and demonstrate that the high field confinement of acoustic graphene plasmons can resolve intrinsically quantum mechanical electronic length-scales with subnanometer resolution. Our findings reveal a promising scheme to probe the quantum response of metals, and further suggest the utilization of acoustic graphene plasmons as plasmon rulers with angstrom-scale accuracy. Knowledge of the quantum response of materials is essential for designing light-matter interactions at the nanoscale. Here, the authors report a theory for understanding the impact of metallic quantum response on acoustic graphene plasmons and how such response could be inferred from measurements.N.A.M. is a VILLUM Investigator supported by VILLUM FONDEN (Grant No. 16498) and Independent Research Fund Denmark (Grant No. 7026-00117B). The Center for Nano Optics is financially supported by the University of Southern Denmark (SDU 2020 funding). The Center for Nanostructured Graphene (CNG) is sponsored by the Danish National Research Foundation (Project No. DNRF103). This work was partly supported by the Army Research Office through the Institute for Soldier Nanotechnologies under Contract No. W911NF-18-2-0048. N.M.R.P. acknowledges support from the European Commission through the project "Graphene-Driven Revolutions in ICT and Beyond" (No. 881603, Core 3), COMPETE 2020, PORTUGAL 2020, FEDER and the Portuguese Foundation for Science and Technology (FCT) through project POCI-01-0145-FEDER028114 and through the framework of the Strategic Financing UID/FIS/04650/2019. F.H. L.K. acknowledges financial support from the Government of Catalonia through the SGR grant and from the Spanish Ministry of Economy and Competitiveness (MINECO) through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-20150522), support by Fundacio Cellex Barcelona, Generalitat de Catalunya through the CERCA program, and the MINECO grants Plan Nacional (FIS2016-81044-P) and the Agency for Management of University and Research Grants (AGAUR) 2017 SGR 1656. Furthermore, the research leading to these results has received funding from the European Union's Horizon 2020 program under the Graphene Flagship Grant Agreements No. 785219 (Core 2) and no. 881603 (Core 3), and the Quantum Flagship Grant No. 820378. This work was also supported by the ERC TOPONANOP (Grant No. 726001)

The role of fishing material culture in communities’ sense of place as an added-value in management of coastal areas

Fishing communities in many places around the world are facing significant challenges due to new policies and environmental developments. While it is imperative to ensure sustainability of natural resources, many policies may overlook the contribution of fisheries to the sociocultural well-being of coastal communities. Authors address the problem of valuing the sociocultural benefits of fishing by exploring the role of fishing landscapes and traditional working waterfronts in maintaining sense of place in fishing communities. The paper explores how sense of place contributes to understanding the relationship between fishing and cultural-ecosystem services, drawing on case studies from four U.S. fishing communities in Brunswick County, North Carolina. Through semi-structured and in-depth interviews with fishing communities members, resident photography and sites visits, this paper outlines how fishing contributes to sense of place in terms of placeattachment and cultural-social memory. By understanding the relationship between fishers’ sense of place, and the physical environment in fishing communities in Brunswick County, the authors identify the complexity and interrelated elements that shape the relationship between fishermen and their cultural landscape. The paper suggests that realizing the value of fishing cultural landscape can encourage policies that promote preservation of fishing cultural heritage for the sociocultural benefit of communitie

Homeostatic regulation of the endoneurial microenvironment during development, aging and in response to trauma, disease and toxic insult

The endoneurial microenvironment, delimited by the endothelium of endoneurial vessels and a multi-layered ensheathing perineurium, is a specialized milieu intérieur within which axons, associated Schwann cells and other resident cells of peripheral nerves function. The endothelium and perineurium restricts as well as regulates exchange of material between the endoneurial microenvironment and the surrounding extracellular space and thus is more appropriately described as a blood–nerve interface (BNI) rather than a blood–nerve barrier (BNB). Input to and output from the endoneurial microenvironment occurs via blood–nerve exchange and convective endoneurial fluid flow driven by a proximo-distal hydrostatic pressure gradient. The independent regulation of the endothelial and perineurial components of the BNI during development, aging and in response to trauma is consistent with homeostatic regulation of the endoneurial microenvironment. Pathophysiological alterations of the endoneurium in experimental allergic neuritis (EAN), and diabetic and lead neuropathy are considered to be perturbations of endoneurial homeostasis. The interactions of Schwann cells, axons, macrophages, and mast cells via cell–cell and cell–matrix signaling regulate the permeability of this interface. A greater knowledge of the dynamic nature of tight junctions and the factors that induce and/or modulate these key elements of the BNI will increase our understanding of peripheral nerve disorders as well as stimulate the development of therapeutic strategies to treat these disorders

Factors that predict early treatment failure for patients with locally advanced (T4) breast cancer

Locally advanced breast cancer (LABC) is associated with dire prognosis despite progress in multimodal treatments. We evaluated several clinical and pathological features of patients with either noninflammatory (NIBC, cT4a-c) or inflammatory (IBC, cT4d) breast cancer to identify subset groups of patients with high risk of early treatment failure. Clinical and pathological features of 248 patients with LABC, who were treated with multimodality treatments including neoadjuvant chemotherapy followed by radical surgery and radiotherapy were reassessed. Tumour samples obtained at surgery were evaluated using standard immunohistochemical methods. Overall, 141 patients (57%) presented with NIBC (cT4a-c, N0-2, M0) and 107 patients (43%) with IBC (cT4d, N0-2, M0). Median follow-up time was 27.5 months (range: 1.6–87.8). No significant difference in terms of recurrence-free survival (RFS) (P=0.72), disease-free survival (DFS) (P=0.98) and overall survival (OS) (P=0.35) was observed between NIBC and IBC. At the multivariate analysis, patients with ER- and PgR-negative diseases had a significantly worse RFS than patients with ER- and/or PgR-positive diseases (hazard ratio: 2.47, 95% CI: 1.33–4.59 for overall). The worst RFS was observed for the subgroup of patients with endocrine nonresponsive and HER2-negative breast cancer (2-year RFS: 57% in NIBC and 57% in IBC) A high Ki-67 labelling index (>20% of the invasive tumour cells) and the presence of peritumoral vascular invasion (PVI) significantly correlated with poorer RFS in overall (HR 2.69, 95% CI: 1.61–4.50 for Ki-67>20% and HR 2.27, 95% CI: 1.42–3.62 for PVI). Patients with endocrine nonresponsive LABC had the most dire treatment outcome. High degree of Ki-67 staining and presence of PVI were also indicators of higher risk of early relapse. These factors should be considered in therapeutic algorithms for LABC

Weekly cisplatin, epirubicin, and paclitaxel with granulocyte colony-stimulating factor support vs triweekly epirubicin and paclitaxel in locally advanced breast cancer: final analysis of a sicog phase III study

The present study aimed at evaluating whether a weekly cisplatin, epirubicin, and paclitaxel (PET) regimen could increase the pathological complete response (pCR) rate in comparison with a tri-weekly epirubicin and paclitaxel administration in locally advanced breast cancer (LABC) patients. Patients with stage IIIB disease were randomised to receive either 12 weekly cycles of cisplatin 30 mg m−2, epirubicin 50 mg m−2, and paclitaxel 120 mg m−2 (PET) plus granulocyte-colony stimulating factor support, or four cycles of epirubicin 90 mg m−2+paclitaxel 175 mg m−2 (ET) every 3 weeks. Overall, 200 patients (PET/ET=100/100) were included in this study. A pCR in both breast and axilla occurred in 16 (16%) PET patients and in six (6%) ET patients (P=0.02). The higher activity of PET was evident only in ER negative (27.5 vs 5.4%; P=0.026), and in HER/neu positive (31 vs 5%; P=0.037) tumours. The two arms yielded similar pCR rate in ER positive (PET/ET=7.5/7.1%) and HER/neu negative (PET/ET=10/6%) patients. At a 39 months median follow-up, 70 patients showed a progression or relapses (PET, 32 vs ET, 38). Anaemia, mucositis, peripheral neuropathy, and gastrointestinal toxicity were substantially more frequent in the PET arm. The PET weekly regimen is superior to ET in terms of pCR rate in LABC patients with ER negative and/or HER2 positive tumours Mature data in terms of disease-free and overall survival are needed to ascertain whether this approach could improve the prognosis of these subsets of LABC patients