Harmonic oscillator with minimal length uncertainty relations and ladder operators

We construct creation and annihilation operators for harmonic oscillators with minimal length uncertainty relations. We discuss a possible generalization to a large class of deformations of cannonical commutation relations. We also discuss dynamical symmetry of noncommutative harmonic oscillator.Comment: 8 pages, revtex4, final version, to appear in PR

Overcoming the incumbency and barriers to sustainable cooling

This article examines cooling in the built environment, an area of rapidly rising energy demand and greenhouse gas emissions. Specifically, the status quo of cooling is assessed and proposals are made for how to advance towards sustainable cooling through five levers of change: social interactions, technology innovations, business models, governance and infrastructure design. Achieving sustainable cooling requires navigating the opportunities and barriers presented by the incumbent technology that currently dominates the way in which cooling is provided—the vapour-compression refrigerant technology (or air-conditioners). Air-conditioners remain the go-to solution for growing cooling demand, with other alternatives often overlooked. This incumbent technology has contributed to five barriers hindering the transition to sustainable cooling: (1) building policies based exclusively on energy efficiency; (2) a focus on temperature rather than other thermal comfort variables; (3) building-centric design of cooling systems instead of occupant-centric design; (4) businesses guided by product-only sales; and (5) lack of innovation beyond the standard operational phase of the incumbent technology. Opportunities and priority actions are identified for policymakers, cooling professionals, technicians and citizens to promote a transition towards sustainable cooling. Policy relevance The priority actions that can overcome key barriers to a sustainable cooling pathway are as follows. (1) Moving building policies beyond energy efficiency to address climate mitigation and adaptation for improving the heat resilience of the built environment. Building indicators are needed to measure the passive survivability to heat. (2) Conventional cooling control and related regulations based exclusively on air temperature require expansion in scope to consider a wider range of thermal comfort variables, thus stimulating technological innovation. (3) Shifting building-centric cooling control to an occupant-centric design, downsizing centralised cooling requirements and enabling adaptive environments integrating personalised environmental control systems. (4) Business models moving from product-oriented to service-based businesses. (5) Environmental cooling considerations that address the humidity influence, the role of energy storage to support renewables through energy flexibility in cooling, and the impact of F-gases. Regulation and citizen empowerment through better environmental labelling can play an important role

Cryptocurrencies as a financial asset: a systematic analysis

This paper provides a systematic review of the empirical literature based on the major topics that have been associated with the market for cryptocurrencies since their development as a financial asset in 2009. Despite astonishing price appreciation in recent years, cryptocurrencies have been subjected to accusations of pricing bubbles central to the trilemma that exists between regulatory oversight, the potential for illicit use through its anonymity within a young under-developed exchange system, and infrastructural breaches influenced by the growth of cybercriminality. Each influences the perception of the role of cryptocurrencies as a credible investment asset class and legitimate of value

Impaired Endothelium-Derived Hyperpolarizing Factor-Mediated Dilations and Increased Blood Pressure in Mice Deficient of the Intermediate-Conductance Ca2+-Activated K+Channel

The endothelium plays a key role in the control of vascular tone and alteration in endothelial cell function contributes to several cardiovascular disease states. Endothelium-dependent dilation is mediated by NO, prostacyclin, and an endothelium-derived hyperpolarizing factor (EDHF). EDHF signaling is thought to be initiated by activation of endothelial Ca(2+)-activated K(+) channels (K(Ca)), leading to hyperpolarization of the endothelium and subsequently to hyperpolarization and relaxation of vascular smooth muscle. In the present study, we tested the functional role of the endothelial intermediate-conductance K(Ca) (IK(Ca)/K(Ca)3.1) in endothelial hyperpolarization, in EDHF-mediated dilation, and in the control of arterial pressure by targeted deletion of K(Ca)3.1. K(Ca)3.1-deficient mice (K(Ca)3.1(-/-)) were generated by conventional gene-targeting strategies. Endothelial K(Ca) currents and EDHF-mediated dilations were characterized by patch-clamp analysis, myography and intravital microscopy. Disruption of the K(Ca)3.1 gene abolished endothelial K(Ca)3.1 currents and significantly diminished overall current through K(Ca) channels. As a consequence, endothelial and smooth muscle hyperpolarization in response to acetylcholine was reduced in K(Ca)3.1(-/-) mice. Acetylcholine-induced dilations were impaired in the carotid artery and in resistance vessels because of a substantial reduction of EDHF-mediated dilation in K(Ca)3.1(-/-) mice. Moreover, the loss of K(Ca)3.1 led to a significant increase in arterial blood pressure and to mild left ventricular hypertrophy. These results indicate that the endothelial K(Ca)3.1 is a fundamental determinant of endothelial hyperpolarization and EDHF signaling and, thereby, a crucial determinant in the control of vascular tone and overall circulatory regulation

A 20-year retrospective analysis of deep venous thrombosis and pulmonary embolism among combat casualties requiring damage control laparotomy at US Military Role 2 surgical units

Combat casualties receiving damage control laparotomy at forward deployed, resource-constrained US Military Role 2 surgical units (R2) require multiple evacuations, but the added risk of venous thromboembolism (VTE) in this population has not been defined. To fill this gap, we retrospectively analyzed 20 years of Department of Defense Trauma Registry (DoDTR) data to define the VTE rate in this population. DoDTR from 2002 to 2023 was queried for US Military combat casualties requiring damage control laparotomy at R2. All deaths were excluded in subsequent analysis. Rates of VTE were assessed, and subgroup analysis was performed on patients requiring massive transfusion. DoDTR (n = 288) patients were young (mean age 25 years), predominantly male (98%) with severe (mean ISS 26), mostly penetrating injury (76%), and high mortality. VTE rate was high: 15.8% (DVT: 10.3% and PE 7.1%). In the massively transfused population, the VTE rate was even higher (26.7% vs 10.2%, p < 0.001). This is the first report that combat casualties requiring damage control laparotomy at R2 have such high VTE rates. Therefore, for military casualties, we propose screening ultrasound upon arrival to each subsequent capable echelon of care and low threshold for initiating thromboprophylaxis. Prognostic and Epidemiological, Level IV

Randomized Clinical Trial of Vitamin D3 Doses on Prostatic Vitamin D Metabolite Levels and Ki67 Labeling in Prostate Cancer Patients

Context: Vitamin D-3 might benefit prostate cancer (PCa) patients because prostate cells can locally synthesize the active hormone calcitriol. Objective: Our objective was to determine the effects of oral vitamin D-3 on vitamin D metabolites and PCa proliferative activity in prostate tissue. Design and Setting: We conducted a double-blind randomized clinical trial at surgical oncology clinics in Toronto, Canada. Patients: PCa patients (Gleason 6 or 7) participated in the study. Of 66 subjects who were enrolled, 63 completed the dosing protocol. Intervention: Vitamin D3 (400, 10 000, or 40 000 IU/d) was orally administered before radical prostatectomy. Main Outcome Measures: We evaluated vitamin D metabolite levels and Ki67 labeling in surgical prostate tissue. Safety measures, PTH, and prostate-specific antigen (PSA) were also assessed. Results: Prostate tissue and serum levels of vitamin D metabolites, including calcitriol, increased dose dependently (P < .03) and were significantly higher in the 40 000-IU/d group than in every other dose group (P < .03). Prostate vitamin D metabolites correlated positively with serum levels (P < .0001). Ki67 measures did not differ significantly among vitamin D dose groups. However, cross-sectional analysis indicated that the calcitriol level attained in prostate was inversely associated with Ki67 intensity and Ki67 (3 +) percent positive nuclei in PCa and benign tissue (P < .05). Safety measures did not change adversely with dosing. Compared with the 400-IU/d group, serum PTH and PSA were lower in the combined higher-dose groups at the end of the study (P < .02). Conclusions: Oral vitamin D3 raised prostate calcitriol levels (level 1 evidence) and modestly lowered both PSA and PTH. Although Ki67 expression did not differ among dose groups, its levels correlated inversely with prostate calcitriol. These suggestions of clinical benefit justify continued clinical research