Phase diagram of microcavity exciton-polariton condensates

In this work, we study the exciton-polariton condensate phase transition in a microcavity matter-light system in which electron-hole Coulomb interaction and matter-light coupling effects are treated on an equal footing. In the framework of the unrestricted Hartree-Fock approximation applying the two-dimensional exciton-polariton model, we derive the self-consistent equations determining simultaneously the excitonic and the photonic condenstate order parameters. In the thermal equilibrium limit, we find a condensed state of the exciton-polariton systems and phase diagrams are then constructed. At a given low temperature, the condensate by its nature shows a crossover from an excitonic to a polaritonic and finally photonic condensed state as the excitation density increases at large detuning. Without the detuning, the excitonic condensed state disappears whereas the polaritonic or photonic phases dominate. The crossover is also found by lowering the Coulomb interaction at a finite matter-light coupling. Lowering the Coulomb interaction or increasing the temperature, the excitonic Mott transition occurs, at which the exciton-polariton condensates dissociate to free electron-hole/photon. Depending on temperature and excitation density, the phase transition of the exciton-polariton condensates is also addressed in signatures of photoluminescence mapping to the photonic momentum distribution.Comment: 7 pages, 6 figure

BIẾN ĐỘNG CỦA TRƯỜNG NHIỆT ĐỘ VÀ MỐI QUAN HỆ CỦA NÓ VỚI ENSO TRONG VÙNG BIỂN NINH THUẬN - BÌNH THUẬN

In this paper, our aim was to examine the role of ENSO in the recent climate variations. Analyzed results on temporal variability of thermal fields in period of 38 years (Jan. 1979-Aug. 2016) showed that Ninh Thuan - Binh Thuan waters were subjected to the significant impact of the ENSO phases (warming and cooling) as well as other processes related to seasonal, inter-seasonal, yearly and mutlti-yearly variations such as in the periods 1986-1989, 1996-2000 and 2009-2011. In order to clarify above issues, authors carried out the analysis of the temporal -spatial changes of temperature fields (include air temperature and sea surface temperature) in Ninh Thuan - Binh Thuan region. The temperature data were exploited from The National Centers for Environmental Prediction (NCEP) and Climate Forecast System Reanalysis (CFSR) in the form of hourly time-series products with spatial resolution of 0.3o (1979-2010) and 0.20o (2011-8/2016). The results showed that 2016 was quite similar to 1998 and 2010 when the coral bleaching occurred in the study area.Các kết quả phân tích trường nhiệt độ trong 38 năm (1/1979 - 8/2016) đã cho thấy vùng biển Ninh Thuận - Bình Thuận chịu sự tác động không nhỏ của các pha ENSO (ấm, lạnh) mà còn có liên quan đến các quá trình khác có chu kỳ mùa, liên mùa, năm, nhiều năm thể hiện tại các giai đoạn 1986-1989; 1996-2000 và 2009-2011. Để góp phần làm sáng tỏ vấn đề trên, chúng tôi đã tiến hành phân tích sự thay đổi nền nhiệt độ của nhiệt độ không khí, nhiệt độ nước bề mặt biển. Các số liệu nhiệt độ sử dụng trong nghiên cứu này được khai thác từ Hệ thống Dự đoán Khí hậu Phân tích lại (CFSR) theo bước thời gian 1 giờ với độ phân giải ngang 0,3° (1979-2010) và 0,2o (2011-8/2016) của Trung tâm Dự báo Môi trường Quốc gia Hoa Kỳ (NCEP). Kết quả phân tích cho thấy năm 2016 có nét khá tương đồng với năm 1998 và 2010, các năm được phát hiện đã xảy ra hiện tượng tẩy trắng san hô tại khu vực nghiên cứu

Impact of participatory guarantee systems on sustainability outcomes: the case of vegetable farming in Vietnam

Sustainable food systems require mechanisms that assure consumers about the sustainability of agricultural production. Building on the existing literature on the impact of sustainability standards, this study is the first to assess the effectiveness of participatory guarantee systems (PGS) for the certification of organic produce. The study uses representative farm-level data on local vegetable value chains in northern Vietnam and uses a broad set of sustainability outcomes as well as counterfactual analysis, including systematic robustness checks. The results show that PGS significantly improves farm profitability (+117%), agroecology performance (+40%), and gives farmers more choice of sales channels (+23%). However, PGS had no significant effect on returns to labour and reduced the average crop yield. Capacity development on nursery practices, transplanting of healthy seedlings rather than direct seeding, reduced tillage, and collective crop planning and management are some of the innovations that can counter adverse effects on crop yields, increase soil health as well as improve returns to labour, and thus attract more youth to farming. Overall, the study shows that organic PGS can make vegetable production more economically viable and more agroecologically sustainable

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Phonon effects in the excitonic condensation induced in the extended Falicov-Kimball model

A ground state of the excitonic condensate in the 2D extended Falicov-Kimball model involving the coupling of electrons and vibrational degrees of freedom has been investigated. Adapting the unrestricted Hartree-Fock approximation, we have derived a set of explicitly self-consistent equations determining both an excitonic order parameter and a lattice distortion when both the electron-phonon coupling and the electron-electron interaction are treated on an equal footing. A ground-state phase diagram of the excitonic condensate depending on the model parameters is constructed. The phase diagram shows us that a window of the excitonic condensate with lattice distortion increases when increasing the electron-phonon coupling or moving up the f-electron level, whereas, it is confined in between two critical values of the Coulomb interaction. The Coulomb interaction and the electron-phonon coupling have been affirmed to act together in establishing the excitonic condensate phase with lattice distortion in dichalcogenide systems. The BCS-BEC crossover of the excitonic condensation in the systems is also addressed

CÁC GIAI ĐOẠN PHÁT TRIỂN CỦA QUẦN THỂ LOÀI RAU SẮNG (Melientha suavis Pierre) THEO SINH TRƯỞNG CHIỀU CAO TẠI CÙ LAO CHÀM, TỈNH QUẢNG NAM

The survey on stem height carried out on 1,887 individuals of Melientha suavis Pierre of all ages in 66 plots (200 m2), representing the topography and forest status on the island, reveals that the traditional identification, according to the Ministry of Agriculture and Rural Development in 2006 and 2018 on the timber development stages in the forest resource inventory, does not properly reflect the biological characteristics and population structure for slow-growing and small tree species like M. suavis. Therefore, we proposed the identification criteria of the growth stages of the plant species based on the height growth. The life cycle of M. suavis can be divided into seven stages of three periods (regeneration, maturity and over-maturity). We also suggested several specific silvicultural technical and management solutions for all periods and development stages of this species.Kết quả khảo sát về chiều cao thân cây trên 1.887 cá thể Rau sắng (Melientha suavis Pierre) ở tất cả các độ tuổi trong 66 ô tiêu chuẩn ứng với diện tích 200 m2, đại diện cho các dạng địa hình và trạng thái rừng, cho thấy cách phân chia truyền thống theo Bộ Nông nghiệp và Phát triển Nông thôn năm 2006 và năm 2018 về các giai đoạn phát triển của cây gỗ rừng trong kiểm kê tài nguyên chưa phản ánh đúng bản chất sinh học và cấu trúc quần thể cho đối tượng cây gỗ nhỏ và sinh trưởng chậm như loài Rau sắng. Từ đó, chúng tôi đề xuất tiêu chí phân chia các giai đoạn phát triển của loài Rau sắng theo chỉ tiêu sinh trưởng chiều cao. Chu kỳ sống của loài Rau sắng được phân thành bảy giai đoạn thuộc ba thời kỳ: tái sinh, thành thục và quá thành thục. Trên cơ sở đó, chúng tôi đề xuất hướng quản lý và các giải pháp kỹ thuật lâm sinh cụ thể cho tất cả các thời kỳ và giai đoạn phát triển của loài